Skip to main content

Full text of "73 Magazine (December 1980)"

See other formats 


mi 


tmberT9B0  $2.9* 


SAS& 


r,.     /•  •• 


UlO 


ai$^((«iu(«i 


U^   iitiulf     ./.-^  0242/ 


iUMttMlLIL 


ivza 

tn^DCUi    AND 


vm'^ 


fe' 


fe 


4 


r 


^  «# 


J 


1 


\'  I 


\ 


^ 


« 


< 


VWIC 


t    r 


t^- 


f^u 


'#^ 


1            ^ 

1 

!  1    ■ 

2 

1              ' 

74470  65946 

i^M»i  . 


l^♦i 


• 


\  i      ' 


t9^\J' 


tempo 

does  it 

again 

THE  WORLD'S  FIRST 
440  MHz  SYNTHESIZED 

HAND  HELD  RADIO 


Tempo  was  the  first  with  a  synthesized 
hand  held  for  amateur  use.  first  with  a 
220  MHz  synthesized  hand  held,  first 
with  a  5  watt  output  synthesized  hand 
held, ..and  once  again  first  in  the  440 
MHz  range  with  the  S-4,  a  fully 
synthesized  hand  held  radio.  Not  only 
does  Tempo  offer  the  broadest  line  of 
synthesized  hand  helds,  but  its 
standards  of  reliability  are 
unsurpassed  ..reliability  proven 
through  millions  of  hours  of  operation. 
No    other    hand    held    has   been   so 


"        Tempo  S-l 

The  first  and  most  thoroughly  field  tested  hand  held 
synthesiied  radio  available  today.  Many  thousands 
are  now  in  use  and  the  letters  of  praise  still  pour  in. 
The  S-1  is  the  rnost  simple  radio  to  operate  and  is 
built  lo  provide  years  of  dependable  service. 
Despite  its  fight  weight  and  small  size  it  is  built  to 
withstand  rough  handling  and  hard  use.  Its  heavy 
duty  battery  pack  allows  more  operating  time 
between  charges  and  its  new  lower  price  makes  It 
even  more  affordable. 

Tempo  S-5 

Offers  the  same  field  proven  reliability,  features  and 
specifications  as  the  S-1  except  that  the  S-3 
provides  a  big  5  watt  output  (or  1  watt  low  power 
operation).  They  both  have  external  microphone 
capability  and  can  be  operated  with  matching  solid 
state  power  amplifiers  (30  watt  or  80  watt  output). 
Allows  your  hand  held  to  double  as  a  powerful 
mobile  or  base  radio. 

S-30,   S89  00*  S-80...St49.00- 

*For  use  wUh  S*i  and  S-S 

Tempo  S-2 

With  an  S-2  in  your  car  or  pocket  you  can  use 
220  MHz  repeaters  throughout  the  U.S.  It 
offers  all  the  advanced  engineering,  premium 
quality  components  and  features  of  the  S-1 
and  S-5.  The  8*2  offers  1000  channels  in  an 
extremely  lightweight  but  rugged  case- 
It  you  Ye  not  on  220  this  is  the  perfect  way  to 
get  started.  With  the  addition  of  the  S-20 
Tempo  solid  state  amplifier  ft  becomes  a 
powerful  mobile  or  base  station.  If  you  have  a 

220  MHz  station,  the  S-2  will  add  tremendous  versatility. 

Price ...5349,00  (With  touch  tone  pad  installed--S399.00) 

S-20..S89-00 

^^  of  De<='  ^*  1  huilf^*'^9  '^Iher 


thoroughly  field  tested,  is  so  simple  to 
operate  or  offers  so  much  value.  The 
Tempo  S-4  offers  the  opportunity  to 
get  on  440  MHz  from  where  ever  you 
may  be.  With  the  addition  of  a  touch 
tone  pad  and  matching  power 
amplifier  its  versatility  is  also 
unsurpassed. 
The  S-4... 5349,00 

With  12  button  touch  tone  pad. ..539900 
With  16  button  touch  tone  pad... 541 9.00 
S-40  matching  40  watt  output 
13.8  VDC  power  amplifier , .3149  00 

Specfffcatlons: 


Frequency  Coverage:  440  to  449  995  MHz 

Channel  Spacing:  30  KHz  minimum 

Power  Requirements:  9.6  VDC 

Current  Drain;  17  ma-standby  400  ma-transmit  (1  amp  high  power) 

Antenna  Impedance:  50  ohms 

Sensitivity;  Better  than  ,5  microvolts  nominal  for  20  db 

Supplied  Accessories;  Rubber  flexantenna  450  ma  nhcad  battery 

pack,  charger  and  earphone 
RF  output  Power;  Nominal  3  watts  high  or  1  watt  low  power 
Repeater  Offset:  i  5  MHz 

Optional  Accessories  for  all  models 

12  button  touch  tone  pad  (not  mslailed);  $39  •  t6  button  touch 
tone  pad  (not  installed);  $4B  •  Tone  burst  generator:  $29.95 
•  CTCSS  sub-audible  tone  control:  $29.95  ♦  Leather  holster: 
$20  •  Cigarette  lighter  plug  mobile  charging  unit;  $6 

TEMPO  VKF  &  UHF  SOLID  STATE  POWER  AMPLIFIERS 

Boost  your  signal,  .  .  give  it  the  range  and  clarity  of  a  htgh 
powered  base  station,  VHF  (135  lo  175  MHz) 


Drive  Power 

Output 

Model  No 

Price 

2W 

130W 

130A02 

S209 

10W 

13DW 

l30AtO 

S1d9 

30W 

130W 

130A30 

S199 

2W 

SOW 

mm? 

S169 

10W 

SOW 

aoAio 

S149 

30W 

Btm 

8OA30 

S159 

2W 

50W 

5QA02 

Si  39 

2W 

30W 

30  A  02 

S  89 

UHF  (400  to  512  MHz)  models,  tower  power  aod  FCC  type  accepted  modelt 

ajso  jivaildt?le. 


2050 S.  Btjndy  Or,  Los  Angeles.  CA  90025     (213)  820-1234 
931  N.  Euclid.  Anaheim.  CA  92801  714  772-9200 

Butler  Missouri  64730  (816)  679-3127 

TDLL  FREE  DRttEfl  NtlMeEfl:  I800t  4Zf  ^Wl 

F&r  aii  Slates  eice[>r  Calrfornca 

Calif  residents  piea^  can  coHea  on  our  regular  numbers 


A  LIFETIME  GUARANTEE  AND  11  OTHER  REASONS  TO  BUY 
AN  "OPTOELECTRONICS"  FREQUENCY  COUNTER 


1.  SENSITIVITY:  Superb  ampTme^ircun^^mT^eWor^ 
that  can't  be  matched  at  twice  the  price.  Average  sensitivity 

of  better  than  15  mV  from  10  H2  to  500  MHz  on  every  model 
and  better  than  30  mV  from  500  MHz  to  1A  GHz  on  the  Series 
8010A  and  8013. 

2.  RESOLUTION;  ai  Hz  to  12  MHz,  1  Hz  to  50  MHz,  10  Hz 
over  50  MHz, 

3.  ALL  METAL  CASES:  Not  only  are  the  heavy  gauge  aluminum 
cases  rugged  and  attractive,  they  provide  the  RF  shielding 
and  minimize  RFI  so  necessary  in  many  user  environments. 

4.  EXTERNAL  CLOCK  INPUT/OUTPUT:  Standard  on  the  8010/ 
8013  senes  and  optional  on  the  7010  series  is  a  buffered 

10  MHz  clock  time  base  input/output  port  on  the  rear  panel. 
Numerous  uses  include  phase  comparison  of  counter  Ume 
base  with  WWV8  (U,S.  National  Bureau  of  Standards).  Stand- 
ardize calibration  of  all  counters  at  a  facility  with  acommon 
10  MHz  external  clock  signal,  calibrate  scopes  and  other  test 
equipment  with  the  output  from  precision  time  base  in 
counter,  etc.,  etc. 

5.  ACCURACY:  A  choice  of  precision  to  ultra  precision  time 
base  oscillators.  Our  ±  1  PPM  TCXO  (temperature  compen- 
sated xtal  oscillator) and  ±  0.1  PPM  TCXO  are  sealed  units 
tested  over  20-40*C-  They  contain  voltage  regulation  circuitry 
for  immunity  to  power  variations  in  main  instrument  power 
supply,  a  10  turn  (50  PPM)  calibration  adjustment  for  easy, 
accurate  setability  and  a  heavily  buffered  output  prevents 
circuit  loads  tromaffectmg  oscillator.  Available  in  the 8010  and 
801 3  series  is  our  new  ultra  precision  micro  power  proportional 
oven  oscillator  With  ±.05  PPM  typical  stability  over  10*45''C, 
this  new  time  base  incorporates  all  of  the  advantages  of  our 
TCXO's  and  virtually  none  of  the  disadvantages  of  the  tradi- 
tional oveni^ed  oscillator:  Requires  less  than  4  minutes 
warm-up  time,  smaJI  physical  size  and  has  a  peak  current 
drain  of  less  than  100  ma. 

6.  RAPID  DISPLAY  UPDATE:  Internal  housekeeping 
functions  require  only  .2  seconds  between  any 
gate  or  sample  time 


period.  At  a  1  second  gate  time  the  counter  will  display  a  new 
count  every  1.2  seconds,  on  a  10  second  gate  lime  a  new  count 
is  displayed  every  10.2  seconds.  (10.2  seconds  is  the  maximum 
time  required  between  display  updates  for  any  resolution  on 
any  model  listed). 

7.  PORTABILITY:  All  modeJs  are  delivered  with  a  115  VAC 
adapter,  a  12  VDCcofd  with  plug  and  may  be  equipped  with 
an  optional  ni-cad  rechargeable  battery  pack  instailed  within 
its  case.  The  optional  Ni  Cad  pack  may  be  recharged  with  12 
VDC  or  the  AC  adapter  provided. 

8.  COMPACT  SIZES:  State^^f-the-Art  circuitry  and  externa!  AC 
adapters  allowed  design  of  compact  easy  to  use  and  transport 
instruments. 

Series  8010/8013: 3'^  H  x  7-1/2"  W  x  6-1/2"  D 
Series  7010: 1'3i4"  H  x  4*1/4"  W  x  5-1/4"  0 

9.  WADE  IN  U.S.A.:  All  models  are  designed  and  manufactured 
at  our  modern  13,000  square  foot  facility  at  Ft.  Lauderdale. 
Florida. 

10.  CERTIFIED  CALIBRATION:  All  models  meet  FCC  specs 
for  frequency  measurement  and  provided  with  each  model  is  a 
certificate  of  NSS  traceable  calibration. 

11.  LIFE  TIME  GUARANTEE:  Using  the  latest  Stateof-lhe-Art 
LSI  circuitry,  parts  count  is  kept  to  a  minimum  and  internal 
case  temperature  is  only  a  few  degrees  above  ambient 
resulting  in  long  component  life  and  reliable  operahon.  ^No 
custom  iC's  are  usedj  To  demonstrate  our  confidence  in  these 
designs,  alt  parts  (excluding  batteries)  and  service  labor 

are  100%  guaranteed  for  life  to  the  original  purchaser. 
(Transportation  expense  not  covered). 

12.  PRICE:  Whether  you  choose  a  series  7010  600  MHz 
counter  or  a  series  8013  1.3  GHz  instrument  it  will  compete 
at  twice  its  price  for  comparable  quality  and  performance, 

MODEL  801  OA/e0 13  1 .1  QHzl^.3  GHz 


MODEL  7010A  600  MHz 


I  D.G 


•010 


0  D  0  0  0. 


«pta»l«Cironlt;s   inc. 


=») 


SEfltES  701OA 

** 701 OA  §00  M H2  Coun let    1  PPM  TCXO 

«7010  lA       feOO  MHJ  Counler   0  1  PPM  TCXC 

OPTiONS 

»70-H  HancJffj^TiH  &ail  (ftoi  *ihdwnj 

#Nl'Cad-70l  mCad  Baiiery  Pack  H Chargmg 

Circuitry  Ingtallsd  Inside  Unit 
#£C"70  £s(iemal  CJock  irtpLiUOutpol 

#CC  70  Carry  Case    Padded  BtacK  Vinyl 


£24995 

S19  95 

S3S.O0 
$9  95 


SEfirESSaiDAJMl3 


«eoiOA 
»eoio.iA 

#80 1 0  05 A 
#S013  1 
#9013.05 


1  1  Gkz Counter  •  i  PPM  TCXO  $399  00 

llGH^Coumer  0.1  PPM  TCXO  S450  DO 

1  a  G  Hz  Cou  n  ter  -  05  P  P  M  O v  e  n  S499,00 

1,3  Qhz  Counier   0  1  PPM  TCXO  $550  00 

1 ,3  GHz  Counter  ■  .05  PPM  Oven  $599,00 


*^SS 


OPTIONS 

f  Ni  Cad  flOt  f^rCaej  SaU^rv  Pack  A  Ctiiirqioq  S49  95 

Gircmtfy  installed  Inside  Unit 
tCC-80         Cafry  Case  •  PadtJea  BiacK  Vinyl  $  9  95 


ACCESSORIES 

iTA- 100        Telescope  anienna  with 

rtght  ang^e  BNC 
tP-100  Probe,  50  Ohm.  IX 

#P'T01  Probe.  Lo  Pass 

Aud^oUsafge 
#P'102  Protje.  Hi-Z 

derieTSl  Purpose 
#LFM  1110    LowFrequei^cyMuMtplief 

X  10.  X  100.  X1000 

For  High  H  lional  AiiCtioFrea 


S  995 

$13  95 


5821  N.E.  14th  Avenue,  Fort  Lauderdale,  Florida  33334 


TERMS  Orders  to  US  3n&  Canacta.  add  S*W  *0f  5iii»&D*ng  nandlmg  and  insurance  io  .a  matimum  o^  &  10  00  An  ^nither  orders  ai*a  15  ^- 
CO  D  coKectron  fe«S2.00  Fld^iiia ofctflfB ^d  4%  state  ta*  Persona* cueciis  must  clear  D©to*e goods ar-  :mii 


1-800-327-5912 

FROM  FLORIDA  (305)  77t*2051/2 


r 


INFO 


Manuscripts 

Gonif  I  buttons  in  the  form  of  marnj- 
scrlpts  with  drawings  and/or  photo- 
graphs are  welcome  and  will  be  con- 
aid  ered  for  possible  pubHcatba  We 
can  assume  no  responsibility  for  loss 
or  damaga  to  any  material.  PEease 
enclose  a  stamped,  salladdressed 
envelope  with  ^&f\  s^Jdmisaton.  Pay- 
men!  for  the  use  of  any  unsolicited 
material  wiU  be  made  upon  accept 
tartce.  All  cofltributeoris  should  be  di- 
rected to  thfi^  T3  ONditorial  offices 
"How  to  Write  tot  73"  guidei^na*  are 
available  uporii  rfi;)iy«3.t 

Editorial  Offices: 

Ptrva  Street 

PEterfoDTOygh  NH  0345S 

Ptione:  603^924-3873,  924^74 

Advertising  Offices: 

Elm  St  reel 

Peterborough  NH  03458 

Phones  i03-924-71 38 

Circulation  Offices: 

eim  Street 

Petertaoroygh  NH  03458 

Phone:  603^924-?296 

Subscription  Rates 

In  the  United  Stales  Am!  PossessidfT^' 
One  Year  02  issues)  SZ^JQO 
Two  Years  (24  iastied^  tSAjOO 
ThfBe  Yeare  (36  issues)  I53JX) 

Elsewhere: 

Canatfa— $27.00n  year  onfy.  U.S, 
funds.  Foreign  surface  mail— $35.00^1 
year  only.  U.S.  funds.  Foreign  air 
m a N— $62.00/1  year  only.  U.S,  funds. 

To  subscribe, 

renew  or  change 

an  address: 

Write  lo  73  Usgszme,  Su^criprion 
Department,  PO  Box  091,  Farming- 
dale  NY  11737.  For  renewaJa  and 
chartQes  of  aildtes^,  ^nc^yde  the  ad- 
dress label  from  your  most  recent 
issue  of  73.  For  gift  sut^scnptiprts,  m- 
Cli>de  yio*if  name  ar^J  address  as  well 
as  those  of  gift  reclpterits,  Postmasier 
Send  form  #0579  to  73  Magsime.  Sub- 
ftcfiption  Services.  P.O.  Box  931  <  Firm- 
lngdale.NY  11737. 

Subscription 

problem  or 

question: 

Write  to  73  Magazine,  Subscription 
Depart  men  t^  PO  Eon.  931,  Farmfngdale 
NY  11737;  Please  Include  an  address 
l9t?eL 

73  Msgazfn&  {fSSN  0098-9010}  ia  pub- 
llstied  monthly  by  73,  Inc.,  80  P^ne 
Street  l^tefborough  HH  0345B.  Sec^ 
QtvtS  Class  po5lag«  paid  at  Petertor- 
ou(^  HH  t^45@  and  at  additional  mai^ 
ifig  offk^s.  Copyfighi  (c)  19S0  by  73, 
Inc.  Atl  rights  merved  No  paii  oi  tfits 
publication  may  be  reprfnted  or  other- 
wise reprodiiced  wrthoul  writlefi  per- 
missiofi  from  ttie  publisher.  Microfilm 
Edilion-'UniversUy  Mlcrolilmp  Ann 
Ait>Of  Ml  4810& 


V. 


Now,  upgrade  faster! 

Here's  30  easy  ways. 

satisfaction  guaranteed  or  return  in  to  days  for  full  refund! 


All  cassettes  60  minutes. 

Theory  Tapes 

Designea  vuitn  an  instructive,  interuiew- 
style  format,  Kantronics  study  Tap^s  ^r^ 
great  supportive  theory  material  for  the 
latest  exams. 

n  Novice  studY  Tape  -  S^.9S 

a  General  studv  T^pe  £^  -  (two)  SS^S 

O  General  0  &  A  Tape    Questions  s>miiar  to 

tnose  or^  tne  FCC  exam  with  goo  a  oosstdie 

answers    Dy    Extranrias^    John    i^nsati^n. 

K0RW  SB  95 
a  Ttte  ffew  Advanced  Study  Tapes  -  (two) 

S11  95 

D  Ttte  New  Extn  ftudy  Tape  $6  9S 

Gradient  Series 

Push  yourself  gradually  with  siowiy  in- 
creasing code  generated  by  computer  to 
exact  Morse  specifications  Tape  tran- 
scripts included 

D  Novice  cradtertt  -  4  to  9  wpivi    S6.9S 
DCeneraiCradlent  7toi5vypM    S695 
D  ^yitrB  Gradient  1 5  to  23  WPM    S6.95 
Q  High  Speed  Gradient  ■  ^B  to  30  WPIVI  56.95 

OSO  Tape  series 

Simuiated  ontfie-air  conversations 
oesignetJ  for  tne  r>ew-styie  FCC  tests  Tape 
transcripts  ano  muiti-criojce  exams  tn* 
ctuded 

DOSOTape   7  5  10.  ISandlSWPM    54  95 
D9SO'2  Tap*    another  notir  of  OSOs  at  7.5, 

10. 13  and  15  WPM    S4  95 
D0SO'15Tape   alllSWPfVI    S4.95 

Oxx  Tapes 

on-che  air  format  at  Extra-class  speeds. 
Tape  transcripts  Included. 

D  OXX  Tape    20.  23  and  26  WPM  with  exam 

DOXX-2  Tap*    another  hour  of  QSOs  at  20 

23and26WPM    54.95 
DO-Slpials  aiKl  Short  words  ■  Learn  to  hear 

groups  of  Jetters  as  unfts  at  high  speed  22, 

33anadOWP1UI    54.95 

Radio  Came 

A  fun  and  educational  Doard  game 
Dased  on  answering  amateur  radio  license 
questions  inciiides  board,  aie,  markers, 
questions  and  answers 

a  Amateur  upgrade  5^.95 


Coid  Label 

D  The  Mysterious  ionosphere  -  By  Jim  Cray, 
W1XU  Learn  now  to  cake  advantage  of  ch^e 
Ionized  layers  that  make  long-aistance 

communication  posslDle.  56.95 

Q  sounds  of  Shortwave  -  By  Bob  Crove, 
WA4PyQ  Listen  to  and  hear  explanations 
of  mysterious  signais  heard  across  tne 
radio  spectrum.  56.95 

D  Mil  and  Outs  of  Running  Yoyr  Own  Ham 
Station  8 v  Paul  Passman,  WBOBBC  A  two- 
tape  set  that  tets  vou  in  on  tne  protocol 
used  Py  experienced  hams,  si  1  95 

D  Cttoosing  the  Best  Antenna  •  By  Jim  Cray. 
W1XU  find  OUT  now  the  ngnc  antenna  can 
dramatically  m crease  vour  stations 
abiHties.  SSM 

Super  Tapes 

Kantronics'  super  tapes  generate 
Characters  sent  at  higher  speeds  with 
longer  spaces  for  easier  copying,  Great  for 
learning  code  and  oreaking  copying  Dar- 
riersf  Transcripts  inctuded. 

D  Super  5  WPM  instructor  teaches  code 
from  Characters  to  words  and  servtences 

S4.9S 

D  Super  QSQ 1 3  OSO  format  with  ennarKed 
codeati3vyPM  S4.9S 

Random  Code 

Random  letters  numders  and  punaua- 
tion  generated  by  computer  in  groups  of 
five  Transcripts  included  for  self -testing. 

D  Novice  frandoiti  S4  95 
G  General  Random  -  54.95 
D  Extra  Random  S4.95 

Booicshelf 

D  Novice-Class  Amateur  Radio  License 
Manual   By  Phit  Anderson  woxi  S3  95 

D  General-Class  Amateur  License  Study 
Guide  By  Phli  Anderson  WOxr  S6.50 

D  rtdtral  Frequency  Directory  S12  95 


Combos 


D  Novice  includes  Nouice  manuaL  Super  s 
yyi^M  tape.  Novice  Studv  Tape  and  OSO 
Tape.  SI  J  95 

□  General  ■  includes  General  manual,  General 
study  Tape  set  and  050-2  Tape  519.95 


Yes,  1  want  to  upgrade  faster! 


Name 


Address 

Citv^_ 


State 


D  Master  Charge    o  Visa    d  Check 
Card  no.  ^^^^^^_^_^^^^_ 

Signature  ^^^^^^^^^^^^ 


•Zip 


Expiration  date 


iude  S1  snipii^ino/ ti^i 


for  slntiie  tapes  and  manuais  or  $3  for  other  orders. 


1 
I 


I  Kantronics 


(913)842-7745 

1202  E  23rd  Street 
Lawrence.  Kansas  66044 


J 


4     73  Magazine  •  December,  1980 


who  Really  Invented  Radio! 

—the  twisted  tale  of  Nathan  B.  Stubblefield 

WB2NEL 

In  Search  of  the  Elusive  SES 

—  track  soiar  activity  with  this  simple  VLF  receiver 
..........  WA3UER 

An  Even  Better  IC  Timer 

—  better  than  what?  WAOPBQ 

Direct  Printing  FAX 

—  part  Ik  constructing  the  facfiimile  recorder 

-.., WB8DQT 


36 


42 


46 


S2 


dm.  80 


MAGAZINE 


HV  Power  Rectifiers 

—amplifier  builders  should  read  this  one 

Cheap  Connectors  for  Half-Inch  Hardline 

—at  your  neighborhood  hardware  store 

WD4LWC  100 

The  Microwave  Midget 

—this  WEFAX  converter  features  something 

different— an  active  mixer ,  ,  .  .  .  W3KH         106 

The  Amazing  Bobtail,  ,  .Our  Readers 
Respond 

—  more  ideas  for  using  and  modifying  this  easy-to- 

build  antenna  W8HXR  110 

Single-Tone  Paging  for  Wilson  HTs 

—simple  circuit  should  work  with  many  rigs 

VV4BF         112 


H'*a   W    r 


A  600-MHz  Universal  Counter 

-you'll  freq  out  over  this  one W4VCZ 

Top-Banding  the  DX-60B 

—  part  J  I:  a  companion  vfo  ........  WBIASL 

An  Amp  for  QRPp  Addicts 

—  buiEd  thts  resistive  step  attenuator  for  tow,  (ow 
power  work. .  WAOI^BR 

The  Center-Fed  Bizarre 

—would  you  believe  an  indoor  antenna  for  60? 

N&RY 

Clean  Sweep  for  the  FT-221 

-don'!  miss  the  action  WBtjLLP 

A  New  Frontier 

—weekends  were  made  for       10  FM!, .  , .    K4TW) 

Scanner  Magic  for  Heath's  2036 

—grab  your  October  79  issue  for  part  I  of  this 
project        .  .  WA4BZP 


58 


64 


68 


72 


82 


84 


88 


Teletext  and  Viewdata:  Are  You  Ready  for  the 

Information  Boom? 

—coming  soon  to  a  living  room  near  you:  video 

data  services  .  WB9KPT         120 

Double-Duty  CW  Keyboard 

—  helps  you  on  receive  as  well  as  transmit 

K1CN  126 

Sixteen  Channels  of  Digital  Delight 

ITji     -do-it-yourself  data  acquisttion 

yiSi      V^B4UHY 


A  Compuler^Controlled  Talking  Repeater 

[I  j|     —part  HI.  interfacing  to  the 

l"Bl     microcomputer ,  ,  WA6AXX 

Make  a  Microcomputerisf  Smile 

-build  him  this  EPROM  eraser 


M 


\a     .  .  AL7C 

Build  2  Talking  Digital  TDer 

— K20AW  redesigns  his  IDer  a(  last  .  K20AW 


132 


138 


148 
162 


Never  Say  Die— 6,  Looking  West— 12,  DX  — 14,  Contests— 16,  RTTY  Loop— 18,  Awards  — 
20,  Leaky  Lines-  22,  Letters— 24,  Fun!  -  26,  OSCAR  Orbits-  28,  New  Products— 32,  Social 
Events—  78,  Ham  Help—  79, 179,  Corrections— 175, 1980  Index— 176,  Review— 181,  Dealer 
Directory  — 225,  Propagation— 225 


73  Magazine  •  December,  1980    5 


NEVER  SAY  DIE 

ecfrtor/a/  tyy  Wayne  Green 


SHADES  OF  THE  PAST! 

The  year  was  1950  and  Wayne 
Green,  not  very  long  out  of  col- 
lege, was  fresh  from  a  job  in  Dal- 
las as  a  television  producer-di- 
rector (the  dannned  station  went 
from  live  productions  to  all  film, 
throwing  the  entire  production 
crew  out  of  work).  I  was  looking 
for  something  temporary  to  tide 
me  over  until  I  could  find  work  in 
television  again. 

Having  a  first  class  ticket  and 
experience  as  an  announcer,  1 
put  an  ad  in  Broadcastmg,  look* 
ing  for  a  com  dilation  spot:  engi- 
neer-announcer. There  was  a  big 
need  for  that  kind  of  experience 
at  that  time  and  I  was  soon  sit- 
ting there  sorting  out  telegrams 
from  over  50  broadcast  stations 
with  good  jobs  open.  One  of  the 
best  bets  was  from  WSPB  in 
Sarasota,  Florida. 

I  loaded  my  ham  gear  into  my 
Old  1941  Ford. .  .NBFM  kilowatt 
for  all  bands,  dfpole  antenna, 
SX-28A  receiver.  -  .and  drove 
down  to  Sarasota,  the  "Air  Con- 
ditioned City/'  It  was  pleasant 
there  temperaturewise,  but  the 
mosquitos  were  worse  than 
those  in  New  Jersey  or  the 
swamps  of  Brooklyn. 

It  didn't  take  long  tiefore  I  set- 
tled into  a  comfortable  routine, 
opening  the  station  mornings, 
lying  on  the  beach  afternoons, 
and  hamming  evenings.  One  of 
the  chaps  who  popped  in  to  do  a 
radio  show  daily  was  Bandel 
Linn,  also  a  ham.  We  hit  it  off 
right  away.  Linn  lived  nearby  on 
one  of  the  keys  and  his  mailbox 
said.  "Corporal  Bandel  Linn/' 
This  was  in  retaliation  for  all  the 
other  mailt>oxes  with  retired  col- 
onels, generals,  and  such. 

One  of  Bandel's  best  friends 
was  a  little  known  writer,  McKin- 
ley  Cantor.  He  became  better 
known  after  his  book,  Anderson- 


viiie  was  published.  He's  had  a 
peck  of  best  sellers  down 
through  the  years.  McKiniey 
would  come  by  the  station  occa- 
sionally with  Bandel  and  we'd 
talk,  I  think  the  thing  I  enjoyed 
the  most  about  both  of  them 
was  their  sense  of  humor. 

McKinley  did  a  number  on 
Bandel  one  time.  He  went  out 
and  bought  an  enormous  num- 
ber of  old  tjooks  from  a  defunct 
used  book  store.  He  had  a 
stamp  made  up  which  said,  "If 
found,  please  return  to  Bandel 
Linn". .  .eta,  along  with  Linn's 
address.  McKiniey  traveled  a  lot 
and  would  drop  off  these  books 
in  stores  everywhere  he  went. 
Bandel  was  soon  up  to  here  in 
returned  books,  arriving  with  ev- 
ery mail  from  all  over  the  coun- 
try... or  peopie  driving  up  to 
bring  them  back  personally. 

When  I  decided  to  start  a  ham 
magazine  in  1960, 1  got  in  touch 
with  Bandel,  who  in  addition  to 
being  a  great  radio  personality 
was  also  a  nationally  known  car- 
toonist, and  got  him  to  do  the 
cover  for  issue  #t.  Bandel  is  still 
cartooning  and  broadcasting, 
holding  forth  from  Pensacola 
these  days.  I  get  to  see  him  ev- 
ery now  and  then  when  1  get 
down  to  Mobile  for  the  reunion 
of  my  old  submarine  crew* 

There  are  a  few  people  I've 
known  who  have  really  been  en- 
joyable to  talk  with.  .  .such  as 
Jean  Shepherd,  John  Campbell, 
and  Linn.  All  are  hams,  oddly 
enough,  though  1  seldom  talked 
hamming  with  any  of  them. 
John  is  gone  now.  but  he  left  a 
raft  of  admirers.  I'm  sure  it  was 
his  editorials  in  Astounding  Sci- 
Bnce  Fiction . .  .and  later  in  Ana- 
log,., which  got  me  started 
writing  long  editorials, !  enjoyed 
them  for  years  and  it  just  never 
occurred  to  me  that  an  editor 


would  do  anything  other  than 
write  long  editorials.  I  don't 
think  I  gave  it  much  thought  un- 
til a  couple  of  months  ago  when 
it  suddenly  dawned  on  me  that 
I'm  probably  ttie  on/y  editor  writ- 
ing these  damned  things. 

Of  course  the  pressures  of 
writing  editorials  for  three  big 
magazines  a  month,  plus  a 
fourth  just  for  the  micracomput- 
er  industry,  and  the  shadow  of 
two  more  magazines  getting 
started  all  helped  to  focus  my 
awareness  on  a  good  thing  over- 
done. Now.  with  a  month-long 
trip  coming  up  to  Asia,  the  man- 
aging editors  are  pushing  me  to 
write  a  month  ahead.  Hells  bells, 
1  can  hardly  get  'em  done  for  one 
month,  much  less  two. 

We've  got  a  series  of  cartoons 
by  Bandel  starting  in  the  maga- 
zine. I  hope  you  enjoy  his  humor 
as  much  as  I  do. 

THAT  ARKANSAS  WARHEAD 

Those  of  you  who  read  the 
fine  print  on  the  silo  explosion  in 
Arkansas  may  have  noticed  that 
the  newspapers  were  able  to 
print  a  transcript  of  a  tape-re- 
corded Air  Force  radio  conver- 
sation about  the  search  lor  the 
warhead.  Some  chap  has  receiv- 
ers tuned  to  Air  Force  and  other 
channels  with  recorders  ready 
in  case  of  any  emergency . , , 
then  he  Is  able  to  sell  the  Infor* 
mation  to  the  papers.  If  ever 
there  was  a  case  where  the  FCC 
rules  in  Section  605  regarding 
the  privacy  of  radio  transmis- 
sions was  being  broken,  it  is 
here.  If  ihe  FCC  lets  this  go  un* 
touched,  they  are  turning  their 
heads  when  their  rules  are  clear 
ly  t>eing  broken. 

It  is  against  the  law  to  sell  in- 
formation gotten  over  the  air 
from  anything  other  than  broad- 
cast stations.  This  is  the  heart 


of  605.  The  reception  is  not  pro- 
hibited, only  the  use  of  the  infor^ 
mation.  What  are  you  going  to 
do  about  this.  FCC? 

SAROC  SHOOTS  SELF  IN  FOOT 

The  pitiful  shreds  of  what  was 
once  a  halfway  decent  hamfest 
will  be  aired  again  In  January. 
This,  I  believe,  Is  a  commercial 
exploitation  of  hams  for  the  per- 
sonal gain  of  one  chap,  who  the 
iast  I  heard  was  disavowed  by 
all  ham  clubs  which  had  ever 
tried  to  work  with  him.  At  the 
last  of  these  hamfests  I  attend- 
ed, the  technical  sessions  were 
a  joke  and  the  exhibits  few.  The 
advanced  registration  for  this 
disaster  is  $16.  if  you  are  that 
eager  to  throw  your  money 
away. 

The  hamfest  has  been 
bounced  from  one  hotel  to  an* 
other,  presumably  for  some 
good  reason.  Now  it  is  at  the 
Dunes  and  filling  a  date  ob- 
viously unwanted  by  any  sane 
group:  January  1.  Bring  playing 
cards,  If  you  are  so  totally 
desperate  on  New  Years  Day  as 
to  go  to  this  silly  thing, ,  .so  at 
least  you'll  have  something  to 
do. 

One  of  the  major  ham  dealers 
tried  exhibiting  at  the  show  not 
long  ago  and  went  away  totally 
disgusted.  Other  than  some  free 
booze  courtesy  of  Ham  Radio 
magazine,  apparently  out  lo 
help  create  more  alcoholics,  the 
dealer  felt  ripped  off. 

If  you  are  absolutely  des- 
perate to  go  to  Vegas,  wait  a 
couple  days  and  catch  the  Win- 
ter  Consumer  Electronics  Show, 
starting  January  8th,  Then,  if 
you  still  have  time  on  your 
hands,  why  not  come  up  to  Vail 
fertile  ham  industry  convention 
January  10- 17th? 

NARA  EVAPORATED 

A  couple  of  months  ago,  I 
wrote  about  what  appeared  to 
be  a  scam  to  fleece  hams,  with 
the  only  action  I  could  see  com- 
ing from  a  chap  with  a  bad  rec- 
ord..  .convicted  of  conning 
hams,  if  there  was  anyone  who 
did  not^et  his  money  back  from 
NARA,  I'd  I  ike  to  hear  from  them, 

I  first  heard  of  this  one  while 
at  a  hamfest  in  Wiesbaden,  Ger- 
many, last  May.  A  chap  there 
had  just  come  from  the  Dayton 
Hamvention  and  mentioned  that 
NARA  was  there,  taking  mem* 
berships-  I  was  at  a  loss  to  un- 
derstand how  a  group  could  get 
started  without  being  in  touch 
with  me.., it  they  were  legitt- 


6     73  Magazine  *  December,  1980 


^KENXA/OOD 


, .  ^pQet^xtiirr  in  amateur  radio 


TRIO-KEKWOOD  COMMUNICATIONS  INC. 

1111  WEST  WALNUT  /  COMPTON,  CA  90220 


Small  wonder. 


Processor,  N/W  switch,  IF  shift  DFC  option 


TS-130S|V 


An  incredibly  cpmpact,  fuir-featurecl,  all  solid* 
state  HF  SSB/CW  transceiver  for  both  mobile 
and  fixed  operation,  \t  covers  3.5  to  29,7  MHz 
(including  the  three  new  Amateur  band^l)  and  is 
loaded  with  optimum  operating  features  such  as 
digital  display,  IF  shJft,  speech  processor,  nar- 
row/widd  filter  selection  (on  both  SSB  and  CWL 
and  optional  DFC'230  dlgltaJ  frequency  control- 
ler. The  TS-1 30S  runs  high  power  and  the  TS-1 30V 
Is  a  (ow  power  version  for  QRP  applications. 

TS-1 30  SERIES  FEATURES: 

■  80-10  meters,  including  three  new  bands 
Covers  ^h  AmaleuF  oands  Irom  3,3  to  29  7  MHz. 
including  the  new  10,  16.  and  24-MHz  bands 
Receives  WWV  on  10  MHz.  VFO  covers  more  than 
50  kHz  above  and  below  each  500-kH^  band. 

•  Two  power  versJoiw . . .  easy  operation 

TS  I30S  ;uns  200  W  PEP/f60  W  DC  input  on  80  15 
meters  and  160  W  PEP/140  W  DC  on  12  and  tO 
melers.  TS130V  runs  25  W  PEP/20  W  DC  input  on 
all  bands.  Solid'State.  wideband  final  amplifier 
eliminates  Iransmiller  tuning,  and  receiver  wide- 
band RF  ampiitiers  etiminate  preselector  peaking 

-  Built-in  speech  processor 

Increases  audio  punch  and  average  SSB  output 
power,  white  suppressing  sideband  splatter, 


CW  narrow  Ml  de  selection 

"N-W  swiEch  allows  i^election  of  wtde  and  narrow 

bandwidths.  Wide  CW  and  SSB  bandwidths  are 

the  same.  Optional  YK-SeC  (&00  Hi)  or  YK-88CN 

(270  Hi)  filter  may  be  installed  for  narrow  CW. 

SSB  narrow  selection 

"N-W"  switch  allows  selection  of  narrow  SSB  dand- 

wldEh  to  efiminate  QRM,  when  opLional  YK-8eSN 

(1.8  kHz)  filter  is  mstalled.  (CW  tilter  may  still  be 

selected  in  CW  mode  ) 

Sideband  mode  selected  automatically 

LSS  Js  seJected  on  ^0  meteis  and  below,  and  USB 

on  30  meters  and  above  SSB  REVERSE  position 

IS  provided  on  the  MODE  switch. 

Built-in  drgltal  dlspfay 

Six-digit  green  fiuorescent  tube  display  indicates 

actual  operating  tfequency  to  100  Hz  Also  indicates 

external  VFO  or  fixed  cfiannel  frequency,  RlTshifl, 

and  CW  transmit /receive  shifts.  Also  analog  sub- 

diaf  for  backup  frequency  md^cation. 

IF  shift 

Atfows  fF  pass  band  to  be  moved  away  from  mler- 

fenng  signals  and  sideband  splatter. 

Single-conversJon  PLL  system 

Improves  stability  as  well  as  transmit  and  receive 
spunous  characteristics. 

Biiiit-in  RF  attenuator 

Fof  optimum  reject  ion  of  mtermoduJation 

distortion. 

Built-in  VOX 

For  convenient  SSB  operation,  as  well 
as  semibreak'in  CW  with  sidetone. 


Effective  noise  blanker 

Etrmi nates  pulse-type  interference  such  as  ignrtion 

noise. 

BuHI-in  25*kHz  marker 

Accurate  frequency  reference  for  calibratioa 
Compact  and  lightweight 
Measures  only  3-3/4  inches  high,  9-1/2  Inches 
wide,  and  11-9/16  inches  deep,  and  weighs  only 
12.3  pounds.  It  is  styled  to  enhance  the  appearance 
of  any  fivrrf  ot  mnhile  station. 


Optional  DFC-230  Digital  Frequency  Controller 
Allows  ffequency  control  in  20-Hz  steps  witb  L- 
DOWN  micfophone  (supp[»ed  with  0FC-230J.  in- 
cfydes  fouf  memories  f  handy  for  split -frequency 
operation^  and  digital  display  Covers  100  kHz 
above  and  beiow  each  SOO-kHz  band.  Very  compact 


Ask  your  Authonzed  Kenwood  Dealer 
abouHhe  com  pact,  lull -featured,  aJI 
so  lid -state  TS-IM  Senes. 

NOTE:  Price,  specifications  subiect  to  change 
without  notice  and  obligation. 


MATCHING  ACCESSORIES  FOR  FIXED- STATION  OPBRATfON 


PS-30  base-Station  power 
supply  (remoteiy  switch- 

able  on  and  off  with 
TS-1 305  power  switch). 


SP-120  external  speaker 
VF0-12G  remote  VFO 
MC*50  50kQ/500y  desk 
microphone 


Other  accessories  not  shown: 


YK-aeC  (500  H£)  and 
YK-SeCN  (270  Hz)  CW  filters 
YK-88SN  {1  B  kHz) 
narrow  SSB  tiller 
AT-130  compact  antenna 
tuner  (60-10  m.  including 
3  new  bands! 
f^B-100  mobile  mounting 
bracket 


MC-30S  ancJ  MC-35S 
noise  cancelling  hand 
microphones 
PC  t  phone  patch 
TL-922A  linear  amplifier 
HS-5  and  HS-4  headphones 
HC'iO  world  digital  dock 
PS-20  base-station  power 
supply  for  TS-1 30V 


SP-40  compact  mobile 
speaker 


VFO-230  digital  VFO  wdh 
five  memories 


STAFF 


Wftyni  tar«dn  W2NSD/1 

EXECUTIVE  VICE  f>fti£lDfNT 
Snerry  &mytN) 

ASSISTANT  PUiLtSKEft/EOrTOft 
Jsft  Dotray  WBeBTH 

ASSOCIATE  PyeUSHEIVOlRECTOfi 

01^  FUfiUCATIOMS 

li)«^«rcr  F«nnifi  WAlUFY 

UANAQING  iOITOfI 


MAI>4AQING  tDITOR 
SusAn  PhiitH^ck 

NEWS  EOtTOR 
G^ne  Smarte  WdGtOV 

£DITOIllAL  ASSISTANTS 

Nancrr  N<»yd 

FlicHftr^  PT»fl|« 

CONTFttBunNO  EDtTOnS 

CttriS  Brown  N1AUI 

Faul  Grui^  KB«1SIVM 

ADMINISTIUTrVE  ASSISTANTS 

Pmt  Gr«h*m 

ASSOCtATfS 
Rob«n  BAt^er  WB2QFE 

Jim  Cain  KITN 
B>n  Go«f^We-7BFK 

S«iiiS}or  <ira«n 

0iv#  Ingfam  MTWi 

tariy  KanariQt  WB2NEL 

j4it  KftSMT  aozcz 

Oave  Mann  K2AGZ 

Bill  Ppa^flfnali  WA$1TF 

JohnScnulU  W4FA 

fHitef  SlirH  K20AW 


MANUFACTUniNa  MANAaEA 
Moel  S«ir  WB1ARP 

PRODUCTION  MANAQEB^ 
PUBLICATIONS 
Nancy  Salmon 

ASST  PflOOUCTtON 

MANAQEf^iPUBLICATlONS 

Mich^ek  Murphy 

ART  Om ECTOR 
Dldna  Shonk 

pROmCTtOH 

Wiyiam  Andef*;on  III 

SlovQ  Baldwin 

Fall  Burr 

T*dd  Cluif 

Linda  Drow 

Bruct  Hedin 
Kenneth  J aoKson 

Bobs  Kenyon 

Maryann  MelovlAr 

Dlcn  Owens 

R&t>»r|  Sawyar 

Paifice  Scribnet 

Sutun  SyrrvQndB 

PHOfOQftAPHf 

William  HaytJoipti 

lettm  Andat^n 

rypfSETT/WG 
Btrbftfa  iAiU 
Sara  Bedat 
M^ry  KirtMll 
Linda  Locks 
M^chaia  l^aRoch^r* 


CORPOItATE  CONTROLLER 
Chaflm  GamiatH  Jr 

EXECUTIVE  ASSISTANT 
tMtrtnO  Ne» 

ACCOUNttNQ  MANAQEB 

CtRCULATlON  MANAQER 
Ottm  BoudMaati 

CERCULATION 
Doris  0«y 

Patiftiiw  John  ii  doe 

BUIK  SAiES  MANAOEH 

Ginnia  Bau<lr>«ftu 

ADVERTtSlNa 

Jim  Gray  WiXU.  kigf 
Nancy  Qiamett,  Assi.  Mgr 


mate.  The  story  of  a  group  often 
hams  putting  up  $35,000  each  in 
seed  money  didn't  ring  true 
either.  I  know  many  of  the  hams 
with  a  spare  $35,000  and  I  can't 
believe  they  would  put  out  that 
kind  of  ioot  without  checking 
with  me. 

Then,  (  found  out  who  the 
chap  was  behind  the  whoie 
thing  and  remembered  his  pre- 
vious record.  Ask  the  ARRL 
atMDut  it;  OST  ran  hfs  ads  which 
brought  about  the  troubles  and 
the  conviction.  But  if  something 
like  this  was  afoot,  why  no  word 
from  the  ARRL?  They  certainly 
couldn't  say  they  didn't  hear 
about  it... or  that  they  didn't 
Know  the  chap.  I  have  no  expla- 
nation for  this. 

Once  my  editorial  piece  ap- 
peared* NARA  seemed  to  disap- 
pear I  got  a  letter  from  a  ham 
who  had  joined,  saying  he  had 
gotten  his  $10  back  and  that  the 
NARA  telephone  number  had 
been  disconnected,  with  no  for- 
warding number.  He  did  sorr^e 


sleuthing  and  found  that  the 
chap  had  moved  to  Virginia  and 
was  now  operating  under  the 
name  of  Keswick  Sates,  with 
ads  in  the  yellow  sheets.  The  re- 
port went  on  to  say  that  over  two 
hundred  orders  had  been  re- 
ceived with  payments,  but  noth- 
ing had  been  shipped  and  no 
payments  had  been  returned. 
No  explanation  by  mail  to  the 
customers.  W  appears  that  the 
FTC  rules  on  back  orders  has  al- 
ready  been  broken.  Will  he  move 
on  again,  leaving  mulcted  hams 
in  his  wake? 

ELECTRONIC  DESIGN  BUNK 

I  really  hate  it  when  I  see  an- 
other magazine  print  a  letter 
from  some  uninformed  person 
and  it  puts  down  amateur  radio. 
Thanks  to  W51FH  for  sending 
me  a  clipptng  from  the  Septem^ 
ber  13th  issue  of  Efectronic  De- 
sign, wherein  is  a  letter  from  a 
Collins  man,  a  program  engi- 
neer named  Roe.  He  fears  that 
amateurs   now   are   "nothing 


more  than  hobbyists  and  gadge- 
teers,  lacking  the  inquisitive  and 
inventive  spirit  which  made  the 
early  days  of  amateur  radio  so 
productive.  Now,  the  only  inno- 
vations come  from  the  R&O  labs 
of  the  amateuf  equipment  man- 
ufacturers/' 

Amateur  radio  needs  this  type 
of  hogwash  like  another  Incen- 
tive Licensing  attack.  The  facts 
are  quite  otherwise,  as  Roe 
would  know  if  he  were  a  reader 
of  73.  It  is  true  that  the  FCC  has 
been  doing  alt  In  its  power  to 
prohibit  amateurs  from  ^perl- 
menttng  and  pursuing  the  FCC's 
own  regulations  (see  97.1  c)»  but 
despite  this,  amateurs  have 
been  building  more  than  ever  be- 
fore in  history  and  have  been  de- 
veloping new  circuits  and 
modes  of  communications. 

In  case  you  think  that  hams 
are  not  building . ,  .and  I  get  that 
crap  a  lot  from  oW-timers  who 

Continued  on  page  189 


Well ...  I  Can  Dream,  Can't  I? 


by  Bandel  Linn  K4PP 


L 


"I  live  next  door  and  I  came  over  to  thank  you  for  those  little  squiggles  and 
lines  on  my  TV — They're  very  interesting!" 


8    73  Magazine  ■  December,  1980 


10  OpHons  Guaranteed  to  Make  the  Extremely 
Popular  2 A  and  2AT  Even  More  Popular! 


Leather  Case 


BC-25U 
Wad  Charger 


C-CFI 
)arette  Lighter 


IC-BP5 
IC.BP4        Battery  Pock 
IC-BP3       Battery  Case 
Battery  Pack 


IC-DCl 


Battery  Pack 


DC  Regulator 


r 


A  fresh  idea! 

Our  new  crop  of  tone  equipmeni  is  ihe  freshesi  thing  growing 
in  ihe  encoder/decoder  field  today.  All  tones  are  instantly 
programmable  by  setting  a  dip  switch;  no  counter  is  required. 
Frequency  accuracy  is  an  astonishing  ±  .  1  Hz  over  all  temper- 
ature extremes.  Multiple  tone  frequency  operation  is  a  snap 
since  the  dip  switch  may  be  remoted.  Our  SS-32  encode  only 
model  is  programmed  for  all  32  CTCSS  tones  or  all  test  tones, 
touch-tones  and  burst-tones. 
And,  of  course,  there's  no 

need  to  mention  our        ^.^^^^PEM^E^^       TS-32 
I  day  delivery  and 
I  year  warranty. 


.1*' 


> 


\  . 


''^ 


TS-32  Encoder-Decoder 

•Size:  1.25"  x  2.0'' x  ,40" 

•  High-pass  tone  filter  included  that  may  be  muted 

•  Meets  all  new  RS-220'A  specifications 

•  Available  in  all  32  EI  A  standard  CTCSS  tones 

SS-32  Encoder 

•Size:  .9"xL3"xAO" 

•  Available  with  either  Group  A  or  Group  B  tones 

Frequencies  Available: 


Group  A 

67.0  XZ 

91.5  ZZ 

118.8  2B 

156.7  5A 

71.9  XA 

94.8  ZA 

123.0  3Z 

162.2  5B 

74.4  WA 

97,4  ZB 

127.3  3A 

167.9  6Z 

77.0  XB 

100.0   IZ 

131.8  3B 

173.8  6A 

79.7  SP 

103.5   1A 

136.5  4Z 

179.9  6B 

82.5  YZ 

107.2  IB 

141.3  4A 

186.2  7Z 

85.4  VA 

1       110.9  2Z 

146.2  4B 

192.8  7A 

88.5  YB 

114.8  2A 

151.4  57 

203.5  Ml 

Frequency  acciiracy>  ±  J  Hz  maximum  -  40X  to  +  BS^C 
Frequencies  to  250  Hz  available  on  special  order 
Continuous  tone 


Group  B 

TEST- TONES: 

TOUCH-TONES: 

BURST-TONES: 

i            600 
1000 
1500 

697      1209 
770      1336 
852      1477 

1600    1850    2150    2400 
1650    1900    2200    2450 
1700     1950    2250    2500 

2175 

941       1633 

1750    2000    2300    2550 

2805 

1800    2100    2350 

•  Frequency  accuracy,  ±  1  Hz  maximum  —  40~C  to  +  85 °C 

*  Tone  length  approximately  300ms,  May  be  lengthened, 
shortened  or  eliminated  by  changing  value  of  resistor 

Wired  and  tested:  TS'32  $59-95,  SS-32  $29.95 


COMMUNICATIONS  SPECIALISTS 

426  West  Taft  Avenue,  Orange,  California  92667 
(800)  854-0547/  California:  (714)  998-3021 


»^is 


LooKim  msT 


Biif  Pasternak  WA81TF 
24d54-C  NewhafI  Ave. 
Newhatf  CA  91321 

OPEN  REPEATERS  DONT 
EXIST  DEPARTMENT 

There  Is  no  sucti  thfng  as  an 
''open"  repeater— at  least  not  in 
the  eyes  of  the  Federal  Com- 
municallons  Commission.  This 
came  about  as  the  final  result  of 
a  well-intentioned  rulemaking 
request  filed  some  three  years 
ago  by  a  Texas  amateur,  Jones 
Talley  W5TJE  had  requested 
that  closed  and  private  repeater 
operation  be  outlawed.  In  addi- 
tion, Mr.  Talley  felt  that  much 
on-channel  interference  be- 
tween repeaters  could  be  elimi- 
nated by  lowering  all  repeater 
power  levels. 

\  recently  interviewed  Mr. 
Talley  for  Westlink  and  found 
him  to  be  a  most  delightful  per- 
son. Moreover,  he  is  a  very  dedi- 
cated amateur.  He  told  me  that 
the  reasoning  behind  his  twin 
petitions  (There  were  two,  but 
the  FCC  elected  to  combine 
both  into  one  rulemaking  ac- 
tion.) was  that  he  and  many 
others  felt  that  repeater  opera- 
tions that  required  membership 
In  an  organization  were  not  in 
the  spirit  of  the  amateur  service. 
Further,  that  with  the  large  num- 
ber of  repeaters  currently  oper- 
ating, there  was  precious  little 
spectrum  left  for  new  opera- 
tlons.  By  lowering  the  power  lev- 
els, there  would  be  less  chance 
of  on-channel  interference  as 
new  systems  came  into  being.  I 
should  add  that  Mr.  Talley  is  a 
broadcast  engineer  with  many 
years  of  experience  behind  him. 
He  understands  very  well  the 
many  technical  aspects  of  radio 
communication. 

So,  Mr.  Talley  elected  to  file 
his  petitions  to  lower  maximum 
power  levels  for  repeater  opera- 
tion and  also  to  gain  acknowl- 
edgement for  the  concept  of  the 
open  repeater,  a  concept  that 
we  as  amateurs  have  under- 
stood for  years.  For  many 
moons,  things  sat  quiet  in 
Washington— not  a  peep  on  the 
topic.  Most  amateurs,  Including 
me,  had  all  but  forgotten  that 
such  a  rulemaking  request  was 
on  file  with  the  Commission. 

Then,  in  late  July,  came  the 


blockbuster.  It  was  all  but  un- 
noticed by  most  hams  since  it 
was  merely  a  dismissal  order  on 
two  rulemaking  requests,  one  of 
which  belonged  to  Mr.  Tailey,  It 
was  only  after  reading  the  order 
several  times  that  the  implica- 
tions came  to  light,  that  In  the 
eyes  of  the  FCC,  no  such  thing 
as  an  open  repeater  existed.  In 
fact,  the  text  you  are  about  to 
read  is  that  of  the  order  itself-  I 
suggest  that  you  pay  close  at- 
tention to  the  first  portion  of 
Section  2,  because  this  may  well 
set  a  precedent. 

Bvfore  the 

Federal  C am munica tlons  Commission! 

W^^hington,  D.C.  2G5S4 

PR 

FCC  eO-351 

27525 

In  the  Matter  o^ 

Rulemaking  petitions 
requesting  "^open^  repeaters:  and, 
to  require  license  encJorsefnent 
aulhori^ing  repeater  operation. 
nM-2B44  and  FIM<3461 

ORDEFt 

Adoptsd:  June  17,  1960; 

Released:  July  2, 19S0 

By  the  Commlsston: 

1.  Rulemaking  petition  RM2844,  sub- 
mitted by  Jones  P.  Talley  (W5TJE),  oJ  Dal- 
las, Texas,  proposed  that  Section  97  B5  of 
the  Amateur  Radio  Service  rutes  be  amend- 
ed by  adding  a  provision  that  no  repeater  be 
operated  as  a  "closed"  repeater.  In  support 
of  his  petition,  Mr.  Talley  offered  these  rea- 
sons. He  said  that  In  the  majority  of  the 
country,  there  are  no  longer  any  available 
frequencies  for  new  repeaters.  Further,  ac- 
cording to  the  petitioner,  no  one,  in  the  his- 
tory of  the  Amateur  Radio  Service,  has  ever 
had  an  assigned  ora  dosed  frequency.  Vlr, 
Talley  teels  that  the  Amateur  Radio  Service 
should  remain  open  and  clear  for  all  proper- 
ly licensed  Amateur  radio  operators.  In  ad- 
dition, petitioner  suggested  that  Section 
97.67  ot  the  Commission's  Rules  be  amend- 
ed to  lower  the  maximum  amount  of  power 
that  Amateur  radio  stations  in  repeater  op- 
©ration  could  use.  For  example,  on  fre- 
quency bands  above  52  MHz,  the  power 
would  be  50  Watts^  rather  than  100  Watts, 
where  the  antenna  height  above  average 
terrain  is  below  100  feet.  His  reason  for  the 
proposal  Is  that  he  believes  Ihat  most  re- 
peaters are  covering  more  area  than  just 
the  local  area,  theretiy  causing  interference 
between  repeaters  in  surrounding  areas. 
This,  In  turn^  he  alleges,  is  why  the  sur- 
rounding areas  have  no  available  fre- 
quencies. Mr.  Taliey  says  that  lower  maxi- 
mum power  levels  will  correct  this  problem. 
Only  one  comment  vi^as  filed  in  RM  2844. 
Tl>e  Amateur  Radio  Club  of  the  Veterans 
Administration  Medlcai  Center,  Montrose, 
New  York,  supported  the  petition  saying 


that  closed  repeaters  violate  the  spirit  of 
Amateur  radio  communications. 

2,  With  respect  to  the  matter  of  forbid- 
ding a  station  in  repealer  operation  to  be 
closed  to  anyone,  we  do  not  agree  that 
such  a  stance  is  desirable.  The  control  op- 
erator of  the  station  must  be  in  a  posit  ion  to 
deny  access  to  any  person  who  is  violating 
our  rules.  Any  other  view  would  be  con- 
strued as  our  approvai  of  unlawful  acts. 
Moreover,  a  fundamental  principle  is  at 
stake  here.  At  all  times,  the  control  operator 
of  a  station  in  repeater  operation  is  respon- 
sible for  the  proper  operation  of  the  station, 
Open  repeaters  would  militate  against  that 
basic  operator  accountability.  Further,  we 
do  not  concur  in  Mr.  Tal toy's  suggestion  to 
tower  the  maximum  power  I  eve  is  for  repeat- 
ers. The  maximum  power  levels  specified  in 
the  present  rules  are  not  mandatory.  Less 
power  may  always  be  used.  In  fact,  we  ex- 
pect Amateur  radio  operators  to  take  ap- 
propriate means  to  avoid  interfering  with 
each  other's- transmissions.  Amateur  radio 
licensees  have  always  been  l^nown  for  self- 
discipiinlng  and  a  cooperative  spirit  in  the 
use  oi  Amateur  radio  frequencies.  There  is 
no  reason  to  believe  that  they  have  relin- 
quished working  together  to  solve  mutual 
usage  probiems. 

5.  Accordingly,  in  view  of  the  reasons 
herein  given,  it  appears  that  the  public  in- 
terest wooid  best  be  served  by  dismissing 
the  instant  petitions.  Therefore,  IT  IS 
ORDERED,  That  RM-2&44  and  RM  3461 
ARE  DISMISSED  and  that  these  proceed- 
ings ARE  TERMINATED.  For  further  infor- 
mation^  contact  Mauri^ce  J.  DePont,  2025  M 
Street,  N.W.,  Washington,  DC. 20554,  t202}- 
254-6884. 

FEDERAL  COMMUNICATIONS 

COMMISSION 

Wiiiiam  J.  Tricar  loo 

Secretary 

Now,  before  you  run  out  and 
tell  all  your  users  that  they  must 
immediately  purchase  some 
form  of  CTCSS  generator  if  they 
intend  to  continue  operating  on 
your  repeater,  sit  back  a  mo- 
ment and  permit  me  to  point  out 
why  this  is  not  necessary.  We 
must  go  back  Into  the  archives  a 
bit,  but  I  think  you  will  enjoy  the 
trip,  especially  if  you  are  a  new- 
comer to  FM. 

In  the  late  1960s,  amateur  ra- 
dio  FM  and  repeater  operation 
took  off  like  the  proverbial  bat 
out  of  you  know  where.  After  a 
while,  some  amateurs  who  just 
could  not  leave  well  enough 
alone  decided  that  what  repeat- 
ers needed  were  rules,  and  a 
number  of  petitions  were  sent  to 
the  FCC  requesting  these.  As 
usual,  time  went  by,  and  in  the 
interim,  the  problems  inherent 
to  the  implementation  of  any- 
thing new  were  solved.  In  this 
case,  the  solution  took  the  form 
of  individuals  and  groups  pro- 
viding voluntary  coordination 
for  repeater  operations.  Then, 
with  the  arrival  of  the  1970s, 
came  something  known  as 
Docket  18803.  18803's  imple- 
mentation brought  FM  relay 
growth  to  a  screeching  halt.  The 


regulations  were  that  restrictive. 
They  also  were  not  needed— the 
problems  had  been  solved. 

For  a  number  of  years,  ama* 
teurs  from  all  over  the  nation 
worked  hard  to  try  to  initiate 
some  relief  from  the  restrictions 
of  18803-  Among  these  was 
Gapt.  Richard  McKay  K6VGP. 
Dick  owned  a  "private"  category 
repeater  located  in  Palos  Verdes 
and  was  able  to  obtain  ''Special 
Temporary  Authority"  to  oper- 
ate his  repeater  without  24'hour- 
a-day,  full-time  control  opera- 
tors on  hand. 

The  success  of  this  experi- 
ment on  WR6AAD  convinced 
the  Commission  to  issue  an- 
other ''Special  Temporary  Au- 
thority" to  the  Palisades  Ama- 
teur Radio  Club  of  Culver  City, 
California,  for  a  similar  experi- 
ment. After  a  year's  time  and 
many  filings  with  the  Commis- 
sion detatfing  progress  of  the 
experiments,  a  petition  was  filed 
to  permit  what  was  termed  "au- 
tomatic remote  controt"  over 
amateur  repeaters. 

One  of  the  first  actions  taken 
in  the  deregulatory  process  was 
the  adoption  of  two  control 
standards  based  upon  the  clas- 
sification  a  repeater  operated 
under.  A  closed  or  private  re- 
peater could  operate  under  the 
doctrine  of  "fulty  automatic  re- 
mote control/'  while  open  re- 
peaters were  given  limited  relief 
in  the  form  of  "semi-automatic 
remote  control."  I  won't  go  into 
the  details  of  each  at  this  time;  It 
would  taKe  pages  to  do  so.  An 
exact  account  of  the  entire  de- 
regulatory process  can  be  found 
by  going  through  bacl^  issues  of 
73  containing  this  column.  We 
lived  it  and  we  reported  on  each 
step  in1he  long  process. 

What  is  important  is  the  con- 
tention that  this  first  step  in  de- 
regulation of  amateur  relay  ac- 
tivity initially  gave  FCC  recogni- 
tion of  both  open  and  closed/pri- 
vate repeater  operation.  This  be- 
ing the  case,  the  report  and  dis- 
missal order  on  RM-2844  is  a  di- 
rect contradiction  of  what  has 
been  stated  in  the  past.  Addi- 
tionally, while  we  in  amateur  ra- 
dio have  developed  our  own  def- 
initions concerning  relay  sys^ 
tern  operation  categorization, 
the  FCC  never  has  done  like* 
wise.  You  and  1  know  what  con- 
stitutes an  open,  closed,  or  pri- 
vate repeater,  but  the  Commis- 
sion has  never  seen  fit  to  offer 
any  definitions  of  their  own. 

Continued  on  page  192 


12     73  Magazine  •   December,  1980 


NEW  TEN-TEC 
ONNI-C  9  Rand  1hinsceiver« HERCULES  Solid-State  KW  Linear 


TEN-TEC  SUPER  RIG  IS  READV.  For  every  band,  every  band 
condition.  With  the  latest  In  solid-state  hf  technology,  the  latest 
In  features.  To  make  connnunlcations  easier,  more  reliable  — 
super. 

OMNI-C 

The  new  model  in  this  famous  series.  With  new  coverage  and  new  features 
to  make  it  better  than  ever! 

All  9  HF  Bands,  From  160  through  10  meters,  inctuding  the  new  10,  18 

and  24,5  MHz  bands.  Coverage  yoy  can  live  with— for  years  and  years. 

3 -Mode,  2 -Range  Offset  Tuning.  Offset  the  receiver  sechon  or  the 
transmitter  section  or  the  entire  transceiver]  In  2  ranges:  ±500  H^  or  ±4 
kHz.  FoT  complete  flexibility  in  fine  hining,  a  DX  work,  or  net  operations. 

Seven  Response  Curves.  Four  for  SSB.  three  for  CW.  With  new 
switching  to  select  the  standard  2.4  kHz  filter,  optional  1,8  kHz  SSB  filter, 
500  Hz  or  250  Hz  CW  filters,  and  standard  450  and  150  Hz  CW  active 
audio  filters.  Up  to  16  pole&  of  i-f  filtering  plus  audio  filtering  to  handle  any 
situation. 

Built-in  Notch  Filter  and  Noise  Blanker.  Notch  is  variable  from  200 
Hz  to  3-5  kHz  with  a  depth  of  more  than  50  dB.  New  noise  blanker  reduces 
ignidon  and  iine  noise.  Both  standard  equipment. 

"Hang"  AGC.  New,  smoother  operation. 

Super  Specs.  Opttmized  sena^ltilfy— a  balance  between  d^Tiamic  range 
and  sensitivity  (2  /iV  on  160  to  0.3  ftV  on  10  meters)  Greater  dijuantiC 
mnge:  better  than  90  dB.  And  a  PIN  diode  siwilchable  18  dB  attenuator. 
200  watts  Input  on  all  bands!  100%  duty  cyck  on  all  bands  for  up  to  20 
minutes. 

Super  Convenient.  Buik-ln  VOX  with  3  up-fipont  controls.  Bmt~ln  PTT 
control  ai  front  and  rear  jacks.  Bulk-In  Zero-Beat  switch  puts  you  on  exact 
frequency.  Buik-ln  Adjust oNe  Sidetone  with  variable  pitch  and  leveL 
Adjustabfe  ALC  for  full  control  hom  low  pjower  to  ful  output.  2-Speed 
Break-in^  fest  or  slow  speeds  to  fit  operating  conditions.  Buit-In  Speaker 
efiminates  desk  clutter  Automatic  Sideband  Sefectfon— reversible- 
Super  Design*  A//  SoHd'State  and  Broadbanded — from  the  pioneer. 
Ten  Tec.  Modufeir  plug-tn  circuit  boards.  FunOJonal  StyHng  with  convenient 
controb,  full  shielding,  easy-to-use  size  (5%*h  x  14V4*w  x  H^d). 

Super  Hercules  Companion.  Styled  to  n^tch,  plus  separate  receiving 
antenna  capability,  plus  transceiver  front  panel  control  of  linearis 
bandswitching  (one  knob  does  it  aU). 

Full  Acceisory  Line  including  filters,  remote  VFO,  power  supplies, 
keycrs,  microphones,  speech  processors,  antenna  tuners— all  in  matching 
color. 

Model  $46  OMNt.Serie«  C . . . .   S1I89. 


HERCULES 

Amateur  Radio's  first  full  break-in  soSd-state  kW  linear  amplifier  With  the 
reliability  you'd  expect  from  the  pioneer  in  high  power  solid-state 
tcchnobgy — TEN  TEC 

AH  So  lid-State.  No  tubes.  Instead,  HERCULES  uses  two  500- watt  push-pull 
solid-state  amplifier  modules  wtth  an  output  combiner.  Super  solid. 

Broadband  Design.  No  knobs^  no  tuning.  From  the  pioneer,  TEN-TEC  For 
fast,  effortless  changing  of  bands.  Super  easy. 

Automatic  Bandswitching  when  used  with  OMNI  (the  OMNI  bandswltch 
also  controls  HERCULES  bandswitching  through  a  motor  driven  stepping 
switch).  Super  convenient 

Full  Break- In.  HERCULES  puts  the  conversation  back  into  high  power  CW 
operation— you  can  hear  between  every  character  you  send. 

Full  Coverage.  160  through  15  meters  plus  four  "AUX"  positions  for  10- meter 
conversion  by  owner  and  future  band  additions. 

Full  G«llort.  1000  watts  input  on  all  bands,  600  watfe  output,  typical.  Built-in 
foroed-air  cooling,  Ehivinq  power:  50  watts,  typical.  Adjustable  ne^tive  ALC 
voltege.  100%  duty  cyde  for  SSB  voice  modulation:  50%  duty  cycle  for 
CW/RTTV  (k^^own  time  5  minutes  max.)  Continuous  carrier  operation  at 
redut^d  output 

Full  Protection.  Six  LED  stctfus  n^c^oSors  continuously  monitor  operating 
conditions  and  shut  down  the  ampHfier  whenever  any  one  exceeds  set  limits 
(the  exdtcr  automatkaliy  bypasses  the  ampSfi^  under  amplifier  shut-down  for 
barefoot  operation).  The  six  parameters  monitored  are:  1)  overdrive;  2)  im- 
proper control  sw^  setting;  3)  heat  sink  temp.;  4)  SWR;  5)  overvohage/over- 
current  6)  rf  output  balance.  Two  m&ers  monitor  collector  cuin^t,  yohage,  and 
forward/reverse  power.  And  a  hi^ly  effidcnt  automatic  ine  uoHoQe  correakm 
drcutt  (patent  aippbed  lor)  efiminaies  the  need  kx  selectuig  transfarmer  taps, 
prevents  applying  too  high  a  vohage  to  final  amplfier  devices,  becomes 
operative  under  bw  line  conditions^ 

Super  Power  Supply.  FVovkks  approxamateJ^'  45  VDC  @  24  amperes, 
opiates  on  105/125  VAC  of  210/250  VAC.  Tape  wound  transformer  and 
choke  T^uce  weight  450  lbs.)  and  size  (7^1i  x  15%V  x  ISV^M):  Separate 
endosure. 

Super  Styling.  Eteigned  to  match  OMNI,  the  HERCULES  has  the  same 
height  as  OMNI,  pkis  matchffig  bail  and  matchmg  ookxs.  The  front  pand  is 
simpliaty  ir^  itsetf  witfi  two  push-biMlon  switches  {power  and  rnode)  plus  iwo 
knobs  (meter  and  bandswrtch).  and  a  "bteck-out''  monitor  panel  (when  unit  is 
off,  metefs  are  unobtrusive).  AmpBfia-  size  is  5%li  x  16'w  x  iBVd. 

Model  444,  HERCULES  amplifier  &  power  supply. . . .  $157S. 


Experience  SUPER  RIG  at  your  TEN-TEC  dealer,  or  wrtte  for  fuU  detsUi. 


iian 


TEN-TEC.MC 

SEVieftVILLC.  TCMHiSSEE  37162 


Jim  Cain  KfTN 
306  Vemoa  Ayenue 
Vernon  CT  060G6 

THE  NEW  BREED 

Comments  made  here  the 
past  few  months  have  brought 
some  interesting  letters,  most 
reinforcing  our  own  attitudes 
about  DXing  today  compared  to 
a  decade  or  more  ago.  As  very 
little  of  life  in  1980  is  like  life  in 
I960,  it  comes  as  no  particular 
surprise  that  amateur  radio  in 
general  and  DXing  specifically 
often  leave  many  old-timers 
somewhat  cold. 

For  example,  the  FCC  has  just 
announced  that  the  CW  portion 
of  their  exams  is  changing 
again,  with  the  exams  to  be  only 
ten  questions,  fill-in-the-btank 
instead  of  mult i pi©  choice,  and  a 
passing  grade  will  be  only  sev- 
enty percent  instead  of  eighty. 
This  Is  a  test? 

On  the  same  sheet  where  we 
read  that  FCC  news  was  the 
story  of  a  Conditional  class 
amateur  who  was  traversing  the 
court  system  because  he  had 
not»  for  some  obscure  reason, 
been  grandfathered  to  General 
class.  The  FCC  had  called  him  m 
to  take  a  13-wpm  code  test  and 
he  refused.  Obviously,  he 
doesn't  know  the  code*  probably 
cheated  on  his  original  Condi- 
tional test  (with  the  aid  of  an- 
other amateur,  sorry  to  say),  and 
that's  that. 

Aside  from  the  FCC  making  it 
possible  for  people  to  operate 
kilowatt  transmitters  on  the  HF 
bands  with  little  or  no  knowl- 
edge of  what  are  recognized  as 
basic  radio  techniques,  the  ac- 
tual styles  of  operating  today 
often  add  to  the  confusion  and 
lowering  of  standards  on  the 
bands.  Here's  a  case: 

An  American  operated  last 
autumn  from  Africa,  on  CW  only, 
from  a  fairly  rare  country.  Great, 
you  say,  at  least  he  knows  the 


codel   True,   but  his  methods 

frustrated  many  who  also  know 
the  code.  Operating  split,  this 
DXer  listened  up  in  frequency, 
often  as  much  as  50  kHz,  In  addi- 
tion, he  immediately  moved  his 
receiving  vfo  after  each  contact, 
making  It  nigh  impossible  for 
the  good  operators  to  ply  their 
trade  of  finding  his  last  contact, 
zeroing  the  frequency,  and  mak^ 
ing  one  short  call  on  his  known 
listening  frequency — not  "tall- 
ending,*'  mind  you,  but  just  be- 
ing where  the  OX  is  listening  is 
operating  at  its  best.  It  was  not 

to  be  in  this  case. 

It  used  to  be  that  when  the 

neophyte  DXer  discovered  he 
could  not  always  crack  the  pile* 
ups  with  a  hundred  Watts  and  a 
dipole,  pennies  began  going  in- 
to  the  bank  for  an  amplifier,  and 
a  safety  belt  was  purchased  for 
future  antenna  work.  Learning 
to  trust  the  belt,  lean  back,  and 
use  both  hands  on  the  tower 
was  part  of  the  process  whereby 
one  t>eeame  a  "real  ham/*  a 
'•true  DXer/"  or  whatever.  It  was 
simple:  If  you  couldn't  get 
through  to  the  station  you  want- 
ed, either  your  signal  was  too 
weak  or  your  operating  tech- 
nique was  not  appropriate.  And 
the  solutions  were  equally 
straightforward:  Build  a  better 
station,  practice  operating,  and 
be  patient.  As  a  result,  the 
bands  continually  witnessed 
new  crops  of  hams  who  became 
proficient  by  their  own  efforts* 
(Made  It  without  using  the  word 
*%ootstrapsl") 

Now  that  this  hole  has  been 

dug,  I  might  as  well  just  climb  on 
In.  Today's  saviors  of  the  bands 
have  found  new  solutions  to  the 
devastating  blow  of  not  being 
able  to  work  your  favorite  DX 
station.  Those  solutions  are 
called  "nets"  and  "Usts/'  They 
have  ruined  DXing  for  what  it 
once  was:  the  second  most 
competitive  aspect  of  amateur 
radio  (after  contesting). 

It  seems  unlikely  that  anyone 
reading  this  column  does  not 
know  the  net  and  list  style; 
either  one  uses  it  or  hates  it  or, 
occasionaiiyt  both.  Let's  look  at 
the  implications  of  this  new 
breed  of  operator  and  the  possi- 
ble future  in  store  if  the  trends 
continue* 


The  list  and  net  operator  (UN) 
will  tell  us  that  the  new  style  en« 
ables  the  weaker  stations  to 
work  through  to  the  DX,  that  UN 
mamtains  order  on  the  bands, 
that  it  gives  everyone  a  fair 
shake,  and*  hoo-boy,  here  it 
comes,  that  new  DX  operators 
are  spared  the  massive  pileups 
which  had  previously  driven  a 
few  of  them  into  other  pursuits, 
such  as  stamp  collecting,  We 
are  sure  to  hear  from  some  of 
you  with  other  justifications, 
such  as  that  there  are  just  too 
many  hams  on  the  bands  now 
when  compared  to  1960  and  new 
techniques  are  consequently  re- 
quiredj  or  that  maybe  not 
everyone  can  afford  a  second 
vfo  in  order  to  operate  split. 

Of  course,  it  will  t>e  said  that  if 
an  operator  wishes  to  use  UN 
because  he  is  an  inexperienced 
amateur  on  Island  X  (which 
everyone  needs),  it  is  his  own  de- 
cision and  those  who  don't  like 
it  can  lump  it.  Those  who  play 
his  game  will  be  rewarded  with  a 
contact  (often  despite  the  fact 
that  they  can't  hear  him).  Those 
who  refuse  to  play  the  game  will 
go  away  empty-handed. 

A  parallel  The  US  national 
speed  limit  is  now  55  mph,  on 
highways  designed  for  70  mph 
+  driving.  This  was  instituted  in 
1974  to  "save  gas."  and  was 
later  further  justified  by  a  con- 
trived set  of  statistics  "proving" 
the  reduced  speeds  resulted  in 
fewer  highway  accident  deaths. 
Voilal  The  temporary  law  be- 
comes permanent. 

The  fact  is  that  UN  has  driven 
off  more  avid  DXers  in  a  couple 
of  years  than  piieups  ever  did  in 
forty  years.  UH  has  raised  a 
cacophony  of  tooth  grinding  by 
those  With  beams,  amplifiers, 
and  savvy.  UN  is  what  brought 
the  "frequency  policemen"  and 
catcallers  to  their  heyday;  as 
they  trash  the  frequencies  in 
anger  at  their  inability  to  just 
jump  in  there  and  call  until  they 

work  what  they  want. 

In  fact,  highway  deaths  have 
not  gone  down,  particularly  on 
the  limited-access  interstates. 
As  for  fuel  consumption,  guz- 
zlers do  use  less  fuel  at  55  than 
at  70;  so  do,  for  that  matter,  all 
autos.  Now  here's  the  point:  Say 
you  are  driving,  oh,  a  diesel  Rab- 
bit at  50  mpg  and  are  restrained 
to  55  mph  so  the  Cadillacs  can 
produce  16  instead  of  15  mpg. 
You  have  gone  the  full  mile  to 
conserve  fuel;  you  have  reacted 
to  the  situation  in  the  most  effl- 
cientp  intelligent  manner,  Yet^ 


you  are  punished  because  you 
are  in  the  minority. 

Back  to  the  new  DX  station  on 
the  band.  You  wrenched  your 
back  getting  that  new  beam  up, 
smelled  up  the  entire  house 
smoke-testing  your  new  ampli- 
fier, but  now  youVe  LOUD.  Fur- 
ther, you  have  practiced  your 
ham  radio  hobby,  not  expecting 
to  set  the  world  on  fire  your  first 
couple  of  years  on  the  bands, 
but  now  you're  a  "good  opera- 
tor." Now  you've  found  that  DX 
station,  but  they've  already 
taken  calls  from  your  caH  area 
and  you  might  just  as  well  turn 
off  your  radios.  So  mail  your 
postcard  to  the  list  taker  for  the 
next  time^  lake  down  your  beam« 
and  seH  your  amplifier,  because 
when  your  turn  comes,  you 
won't  need  them.  You  won't 
need  your  brain,  either. 

What's  coming  In  the  future? 
Unfortunately,  probably  more  of 
the  same,  as  mediocrity  breeds 
mediocrity.  As  more  and  more 
new  DXers  come  to  know  no  op- 
erating style  other  than  UN, 
they  will  demand,  verily,  that  UN 
becomes  the  norm.  New,  inex- 
perienced operators  may  be 
easily  enticed  into  the  rut,  dur- 
ing that  penod  of  time  when 
they  need  a  sheet  to  determine 
whether  it  is  the  plate  current  or 
me  output  that  is  supposed  to 
be  peaked.  As  UN  grows,  addi- 
tional DXers  will  be  driven  from 
the  bands  only  to  be  replaced  by 
still  more  UN  operators. 

Make  no  mistake  about  it!  It 
already  is  happening,  and  the 
pace  is  accelerating.  Blame  it  on 
the  lax  FCC  exams,  on  the 
Welfare  Stale,  on  the  "Me  De- 
cade/' on  the  weather,  on  the 
Democrats,  the  Republicans, 
the  hippies.  The  only  ones  who 
can  reverse  the  trend  and  make 
DXing  what  it  once  was — a  corrh 
petitive  activity— are  you  and 
me,  DXing  was  never  supposed 
lo  be  easy,  from  the  first  time 
Hiram  Percy  Maxim  used  a  relay 
in  Windsor  Locks  to  work  from 
Hartford  to  Massachusetts.  DX- 
ing has  been  the  true  spirit  of 
amateur  radio.  If  It  ceases  to  be 
so.  many  will  find  new  hobbies 
and  hamming  will  be  the  less  for 
their  loss. 

One  thing  UN  has  done  is  giv- 
en amateur  radio  column  writers 
and  bulletin  editors  some  can- 
non fodder,  as  they  stake  their 
claims  on  one  side  of  the  issue 
or  the  other.  You  may  disagree 
violently   with   this   column's 

Continued  on  page  182 


14     73  Magazine  *  December,  1980 


I  ICOM  Quality  and  Performance  in  the  IMost 

Compact  and  Economicai  Hand-Heid  Designed  for  Ham  Radio. 


IC-2Ar 

Synthesized  2  Meter 
Hand-Held 

FEATURES  YOUVE  WANTED 
t  Touch  Tone '    Pod 

D  800  T/R  ChanneJs. 
Synthesized. 

D  1.5  Watt  Output  High/ 
Low  Power  Battery 
Saving  Switch  to  .15 
Watt. 

Seporate  buiit  in 
Speaker  &  Mic.  Excel- 
lent audio  quality. 

Compact.  About  the 
size  of  a  dollar  bill. 

Variable  size  NiCd 
Power  Pack,  3  sizes 
available  to  suit  your 
needs.  (250  MA  stand- 
ard). Makes  the  IC-2AT 
the  most  compact  syn- 
thesized Hand-Held  on 
the  market, 

ICOM  level  Receiver 
Performance-ICOM 
Quality  Receiver  in  a 
compact  package 
(.2uv/20db  typical) 

D  Optional  Leather  Case, 
Mobile  Charge  Cord, 
Desk  Charger, 
Speaker/Mtc 

available, 

n  With  slip  on/slip  off 
Bottom  NiCd  Pack,  you 
can  vary  the  size  of  the 
Hand-Held  from  about 
116  mm  high  to  175 
mm  high.  Easy  to  carry 
extra  Snap-on  packs 
packs  with  you  for  ex- 
tended trips. 

D  Complete  with  BP3 
NiCd  Pak,  wall  charger. 
flexible  antenna  and 
belt  clip. 


BACK  VIEW 
600  khz  offset 

simpiex/dupiex 
Hr/io  pow< 


TOP  VIEW 

BNC  antenna  connector 

"Rubl:>erDuckle" 

standard 

transmit  indicator 

squelch 

volume 

control 


on/off 
S'khz  channel  selection 
1 0  khz  channel  selection 
speaker/mic  jack 


ICOM 


ICOM  AMERICA,  INC 

2112  -  n  6m  Avenue  NE 
Bellevue.  WA  98004 

3331  Towewood  Dr,.  Suite  307 
Dallas,  TX  75234 


Cut  out  and 
put  the  ICOM  IC-2AT 
in  the  palm  of  your  hand. 


CONTESTS 


Robert  Baker  WB2GFE 
tS  Windsor  Or 
Atco  NJ  08004 

CONNECTICUT  QSO  PARTY 
Starts:  2000  GMT  December  6 
Ends:  0200  GMT  December  8 
Rest  period:  0500  to  1200  GMT 
December  7 
Sponsored    by    the    Candle- 
wood  Amateur  Radio  Associa- 
tion (GARA).  Phone  and  CW  are 

considered  to  be  the  same  con- 
test. Stations  may  be  worked 
once  on  each  baod  and  each 
mode.  Out-of-state  portables 
and  mobiles  operating  in  Con- 
necticut are  requested  to  identi- 
fy themselves  as  such  as  are 
Connecticut  mobiles  operating 
fn  other  counties. 

EXCHANGE: 

Send  QSO  number,  RS{T),  and 
ARRL  section  or  Connecticut 
county. 

SCORING: 

Out-of-state  stations  multiply 
total  QSOs  by  the  number  of 
Connecticut  counties  worked  (8 
maximum).  Connecticut  sta- 
tions multiply  total  QSOs  by  the 


sum  of  ARRL  sections  and  prov- 
inces. Additional  DX  contacts 
count  for  QSO  points,  but  only 
one  DX  multiplier  overall  is  al- 
lowed. W1QI,  the  club  station, 
will  be  operating  CW  on  the  odd 
hours  and  SSB  on  the  even 
hours,  and  counts  as  5  points  on 
each  band  and  mode.  Novice 
conlacts  count  as  2  points  each 
and  OSCAR  contacts  count  3 
points  each. 

PREOUENCIES: 

CW— 40  kHz  up  from  the  bot- 
tom of  each  band. 

SSB  — 3927,  7250,  14295, 
21370.  28540. 

Novice— 3725,  7125.  21125, 
28125, 

ENTRIES  &  AWARDS: 

A  Worked  All  Connecticut 
Counties  certificate  will  be 
awarded  to  each  station  work- 
ing all  Cooneottcul  counties. 
Other  awards  given  as  usuai. 
minimum  of  5  QSO  points!  Logs 
must  show  category,  date/time 
(GMT),  Stations,  numbers, 
bands.  QSO  points,  and  claimed 
scores.  Enclose  a  large  SASE 
for  results.  Logs  must  be  post^ 
marked  by  January  2nd  and  sent 
to:  CAR  A,  c/o  Steve  Grouse 
KA1ECL,  3  Queens  Court,  Dan- 
bury  CT  06810, 

CANADA  CONTEST 
Starts:  0001  GMT  December  28 

Ends:  2359  GMT  December  28 

Sponsored  by  the  Canadian 
Amateur  Radio  Federation,  the 
contest  is  open  to  all  amateurs. 


MLENOAR 


Dec  6-7 
Dec  6^8 
Dec  13-14 
Dec  28 
Jan  3*5 
Jan  10-11 
Jan  17-18 
Jan  17-18 
Jan  17  19 
Jan  18 
Mar  7-8 
Mar  21  22 
Aug  8-9 
Sep  12^13 
Nov  14-15 


ARRL  ISO-Meter  Contest 

Connecticut  QSO  Party 

ARRL  10-Meter  Contest 

Canada  Contest 

Zero  District  QSO  Party 

Hunting  Lions  In  the  Air 

73's  International  160-Meler  Phone  Contest 

Michigan  QRP  Club  CW  Contest 

QRP  SSB  QSO  Party 

FRACAP  Wortdwide  Contest 

1S81  SSTV  Contest 

Bermuda  Contest 

European  DX  Contest— CW 

European  DX  Contest— -Phone 

European  DX  Contest— RTTV 


Use  all  bands  from  160  to  2  me- 
ters, CW  and  phone  combined, 
and  everybody  works  every* 
body.  Classes  of  entry  include: 
single-operator,  all  band;  single- 
operator,  single-band;  and 
multi-operator,  single-transmit- 
ter, all  band.  All  contacts  with 
amateur  stations  are  valid.  The 
same  station  may  be  worked 
twice  on  each  band:  once  on  CW 
and  once  on  phone.  No  cross- 
mode  contacts  and  no  CW  con- 
tacts in  the  phone  bands  al- 
lowed. 

EXCHANGE- 

Signal  report  and  consecutive 
serial  number  starting  with  001. 
VEt  stations  will  also  send  their 
province  (NS,  NB.  PEI>. 

SCORfNG: 

10  points  for  each  contact 
with  Canada,  1  point  for  each 
contact  with  others,  10  bonus 
points  for  each  contact  with  any 
CARF  otficiai  news  station  us- 
ing the  suffix  TCA  or  VGA.  Multi- 
pliers are  the  number  of  Canadi* 
an  provinces/territories  worked 
on  each  band  and  mode  (12 
provinces/territories  x  8  bands 
X  2  modes  for  a  maximum  of 
192  possible  multipliers). 


FREQUENCIES  (as  appHcabfe): 
Phone— 1810,   3770,  3900, 

7070,  7230,  14150,  14300,  21200, 

21400,  28500,  50100,  146520. 
CW— 1810.  3525.  7025.  14025, 

21025,  28025,  50100, 144100. 
Suggest  phone  on  the  even 

hours  (GMT),  CW  on  the  odd 

hours. 

AWARDS: 

The  CARF  Canada  Contest 
Trophy  will  be  awarded  to  the 
highest  scoring  single-operator 
entry.  Certificates  will  be  award- 
ed to  the  highest  score  In  each 
entry  class  in  each  province/ter- 
ritory, USA  call  area,  and  DX 
country,  to  the  highest  score 
from  a  Canadian  non-advanced 
amateuf  (no  phone  on  3,5-21 
MHz),  and  where  participation 
warrants. 

ENTRIES 

A  valid  entry  must  contain  log 
sheets,  dupe  sheets,  and  a  sum* 
mary  sheet  showing  a  chart  of 
multipliers  per  band/mode  and 
score  calculation.  Send  your  en- 
try with  comments  to:  Canadian 
Amateur  Radio  Federation, 
203-1946    York    Avenue,    Van- 

ContinuBd  on  page  182 


RESULTS 


BERMUDA  CONTEST  1980 

G14ELQ 

102,600 

RESULTS 

GI4ISR 
G3TKF 

72,080 
56,140 

West  Germany 

G2FXQ 

16,290 

,     DK9WB 

383,295 

G4FJT 

13,910 

DK5EZ 

343.600 

G4HQN 

7,370 

DL7SU 

113.220 

G4GFH 

5,680 

DF6U0 

109,410 

DF9ZP 

78,715 

Canada 

DK80P 

32,065 

VE5BA 

100,270 

DF6JX 

22,100 

VE3HGZ 

99,000 

DF1JI 

19,450 

VE1AIH 

72,450 

DF6AT 

15,795 

VE3NE 

45,560 

D120Y 

14,740 

VE2NL 
VE3DJX 

43.520 
13,870 

USA 

VE3KK 

8,550 

W3MA 

128,975 

VE4ADS 

2,520 

N1Z2 

125.775 

KB8JF 

71.225 

Bermuda 

K3DH 

39,600 

VP9IB 

3,025.000 

WA2RUX 

31,510 

VP9IX 

1,128,245 

W3HNK 

25.415 

VP9IW 

557.230 

K6SVL 

16,260 

VPaiQ 

68.370 

KA1  £P 

15,900 

W9RE 

14,880 

ChBCk  Logs                   \ 

W2FFQ 

12.500 

DFOHX 
DL0JK 

VP9CP 
VP9HL 

UnH9d  Kingdom 

HI3DJPAA/2 

VP9II 

G4DSE 

532,740 

VE3PeVP9 

VP91J 

G3VPW 

484.560 

VE7VX 

VP9KL 

G3V0F 

267,930 

VP9AD 

W3ARK 

16     73  Magazine  ♦  December,  1980 


at  Lunar  Electronics. 


•t  - 


All  Lunar  products  are  designed  and 
manufaclufed  under  the  difect  super- 
¥tsion  of  Louis  Anciaux.  head  ol  Lunar 
Electronics.  While  Lunar  mamlains  a 
complete  QA  department.  Louis  con- 
trols the  final  check-ouL  If  its  not  rtght. 
ffs  not  shipped* 

Thar$  why,  fn  amps,  pre-amps, 
and  Iransverler  modules.  Lunar  Is  con- 
srdered  the  standard  ol  the  industry.  As 
in  all  ham  products,  you  get  what  you 
pay  for. . .  thaf  s  why  Lunar  is  your  tsesi 


llv 


1l 


T  W  t 


^S- 


^  d 

^ 

^TJT"  • 

^^^^^^v 

1    ^  ^  ^ 

* 

••V 

A 

mikk 

iW^^^^ 

\r 

-iS* 

m^ 

^^M- 


i 


/ 


.'i 


UIHAR  LINEARIZED  AMFUFIERS 

One  reason  our  Linearized  amp/pre~amp 
combos  are  the  best  selling  amps  in  the  ama- 
teur market  is  the  superior  lir^eanty  our  units 
exhibit  in  Ihe  SSB  mode.  To  be  "Linear;"  the 
amplrfier's  output  signal  musi  be  an  exact 
reproduction  of  the  inpulsignali  with  onty  the 
power  level  changed. 

Lunar  is  the  onginator  of  the  LIMEAR- 
fZED  process,  and  b\\  of  our  amps  exhibit 
this  by  the  very  small  amount  of  side-spJatier 
produced.  Others  may  attempt  to  copy  us. 
But.  why  buy  a  copy  when  you  can  have  the 
originaL 

2  Meter  Amps 

40  to  160  watt  power  output.  From  M24*5 

For  220  MHz 

25  to  140  wall  power  output  From  »159*^ 

For  6  Meters 

50  to  120  watts  From  M99*^ 

Commercial  and  other  special  frequencies 

available. 


LUNAR  TRANS  VERIER  MODULES 

The  addition  of  LunarTransverler  Modules  to 
your  present  transceiver  m  various  combina- 
tions expands  your  station  s  coverage  from 
HF  through  UHF 

FOR  conmuifrcATfON  cambilitv 

Adding  Lunar  Traosvener  Modutes  to  your 
present  transceiver  allows  you  to  include 
working  Oscar  Phase  III.  exploring  220MHz 
SSB,  or  many  other  present  and  luture  uses 
of  amateur  radio. 

FOR  AMATEUR  TV  (ATV) 

Special  Lunar  Transverter  Modules  can  allow 
you  to  transmit/receive  440  MHz  ATV  signals 
from/to  Channel  3  IF 

AMATEUR  RJUUO  ASTRONOMY 

Lunar  can  provide  you  with  modules  for  re* 
ceiving  noise  from  the  sky  (make  your  own 
sky  noise  ct>art>.  or  from  the  sun  (plot  occur- 
ances  of  flares),  W©  even  have  modules  that 
receive  the  weather  satellite  transmissions 
(they  can  be  connected  to  your  home  com- 
puter for  a  weather  map  prini-out  on  your 
CRT  display). 


LUNAR  RECETYINO  PRE-AMPURERS 

These  ultra-performance  receiving  pre-amps 
are  suitable  to  the  most  demanding  needs 
where  low  noise  figure  ts  important  Uses 
include  all  types  of  weak  signal  work  such  as 
EME.  Tropo.  lono  and  Meteor  Scatter.  Satei- 
lite  Communications,  Radio  Astronomy 
weak,  etc  Absolutely  the  highest  quality  con- 
struction and  components. 
Models  for  all  amateur  bands  through  1296 
pn  ced  from  *3S** 


ectronics    - 


278S  Rur^  Street  ^tO 

SwD«es^CAd21I0 

(714)  299-9740    TELEX:  lAI  747 


RTTY  LOOP 


Marcf,  Leavey,  M.O.  WA3AJR 
4006  Wintee  Road 
Ran<ialtstQwn  MD  2tt33 

December  would  be  a  bleak 
monlh  indeed,  if  K  were  not 
for  the  holidays  at  the  end. 
Whether  you  celebrate  Christ* 
mas  Of  Hanukkah,  or  lust  enjoy 
exchanging  gifts,  the  season 
provides  a  warm  flicker  in  the 
middle  of  winter. This  month,  we 
will  look  at  some  gift  ideas  for 
the  amateur  involved  in  RTTY. 
Perhaps  this  will  give  you  an  ex- 
cuse to  iet  thfs  copy  of  73  sit 
around  where  someone  else  can 
see  it! 

At  the  outset,  iet  me  make  it 
clear  that  I  am  not  describing  ex- 
pensive or  exotic  Jtems.  Most  of 
these  will  be  under  ten  dollars, 
and  many  far  less  than  that.  Sev- 
eral of  them  are  not  even  exciu- 
sivety  amateur  radio  items, 
which  will  make  it  that  much 
easier  for  the  spouse  or  child  to 
find.  Above  all,  1  have  tried  to 
compile  a  list  of  unique  gift 
ideas  thai  are  affordable,  use- 
ful, and  obtainabiet  any  one  of 
which  would  delight  the  heart  of 
the  recipient. 

As  any  of  us  in  RTTY  know,  it 
is  the  little  things  that  mean  a 
lot.  A  trip  to  any  stationery  store 
will  turn  up  many  items  useful  to 
the  RTTYer.  Ribbons  are  always 
needed  by  the  hard-copy  devo- 
tee. There  is  no  need  to  look  far 
and  wide  for  Teletype*  ribbons; 
standard  Underwood  typewriter 
ribbons  are  a  perfect  fit  and  are 
ysuaJiy  much  more  available. 


For  hard  usage,  heavily  inked 
cotton  ribbons,  specifically 
made  for  tefeprinter  appiica* 
tions,  are  best,  and  these  may 
often  be  found  at  larger  office 
supply  houses. 

What  do  we  type  on  but  paper, 
and  this  is  another  item  often  in 
short  supply  In  the  shack.  I  have 
found  that  standard  roll  paper, 
B.5  inches  wide,  is  available 
from  most  business  form  suppit* 
ers  at  a  fairly  reasonable  price. 
Look  In  the  Yellow  Pages  for  a 
supplier  near  you  and  check  sev- 
eral out.  While  you  are  asking, 
check  on  the  availability  of 
11/32-inch  paper  tape.  This  is  an* 
other  perpetua!  "need"  of  the 
teleprintophite^  especially  one 
who  is  involved  with  RTTY  art  or 
traffic,  both  of  which  are  quite 
popular  this  time  of  year.  A  I* 
though  hamfests  are  usually  the 
most  economical  places  to 
stock  up  on  these  paper  goods, 
they  can  be  had,  albeit  at  list 
price,  from  dealers  in  most 
areas. 

Maintenance  items  for  the 
mechanical  teleprinter  are  often 
overlooked  and  fall  into  the 
"make-do"  category.  How  about 
a  big  can  of  grease  for  the  type 
bars?  Lubriplate  is  one  popular 
make  and  is  available  at  most 
large  hardware  stores,  Don't  for- 
get the  oil  for  the  felts-  I  use 
automobile  oil;  get  something 
expensive  for  snob  appeal— it 
goes  a  fong  way!  is  the  print  all 
mucked  up?  Get  back  to  the  sta- 
tionery store  for  some  type 
cleaner  All  kinds  of  products 
are  available,  from  liquids  to 


7500  SALES 

OPPORTUNITIES 

FOR  YOUR  COMPANY 


Be  part  of  the  ROCHESTER  SHOW 
MAY  15-1 6.  Largastshow  In  NORTH- 
EAST and  CANADA. 

Call  or  write  HAROLD  SMITH 


716-424-1  too 


P.O.  Box  1366 
Rochester,  HY  14603 


gobs  of  sticky  stuff  to  press  Into 
\he  type.  The  kind  I  have  found 
most  useful  is  a  sheet  designed 
to  be  placed  into  the  machine, 
like  a  piece  of  paper,  with  the  rib- 
bon  off.  Run  all  the  characters  a 
few  times  on  tape  and  the  type 
is  clean!  A  sure  winner  for  any* 
one. 

Perhaps  the  ham  is  interested 
in  keeping  the  shack  looking  tip- 
top (obviously  never  saw  mine*}. 
Black  wrinkle  finishes,  such  as 
are  found  on  many  kinds  of 
RTTY  equipment,  perk  up  nicely 
under  a  coat  of  black  liquid  shoe 
polish.  When  you're  getting  a 
bottle,  pick  up  some  paste  wax, 
the  old-fashioned  kind,  for  other 
equipment  finishes  around  the 
shack.  A  bottle  of  spray^on 
glass  cEeaner  would  round  out  a 
*'spic-and'Span"  gift  package* 

Another  item,  the  need  for 
which  is  obvious  to  anyone  who 
ever  worked  on  a  teleprinter 
away  from  running  water,  is  a 
box  of  pre-moislened  hand 
wipes,  like  "Wash-n-Dry."  Cer- 
tainly not  expensive,  but  throw  it 
Into  any  of  the  above  packages, 
or  by  itself,  and  it  will  be  appre- 
ciated the  first  time  something 
breaks  down. 

For  the  RTTYer  who  is  using  a 
computer,  consider  a  supply  of 
cassettes  or  diskettes.  Neither 
Is  very  expensive,  but  they  come 
in  handy  when  you  need  to  make 
a  record  of  something.  Diskette 
cases,  which  are  now  stocked 
by  many  office  supply  houses, 
come  in  useful  for  organizing 
the  disk-based  shack;  cassette 
racks,  which  are  available  In  a 
wide  variety  of  styles  at  audio 
and  discount  houses^  do  the 
same  for  the  taper. 

Consider  reading  material. 
Subscriptions  to  73  Magazine, 
RTTY  Journaf,  or  other  amateur 
radio  publications  may  be  just 
the  ticket.  If  computers  are  in- 
volved, try  Kilobaud  Microcom- 
puttng,  BO  Microcomputing  (for 
the  TRS-80  addict),  68  Micro 
Joumah  or  any  of  the  other  com- 
puter magazines.  Look  through 
the  73  Bookshop  ad  in  the  back 
of  this  magazine  fof  many  titles 
of  interest  to  the  RTTYer,  com* 
puterist,  and  ham  in  general 
There  is  surely  one  there  to  de- 
light any  ham. 

in  the  realm  of  reading  materi- 
al that  may  be  more  difficult  to 
come  by,  is  there  a  set  of  man- 
uals to  the  RTTY  machine  in 
your  life?  The  Teletype  Corpora- 
tion put  out  extensive  manuals 
on  the  Model  15.  Model  19, 
Model  26,  and  other  Teletype 


machines  in  common  use.  If 
you,  or  your  ham,  do  not  have 
them,  check  the  ads  for  suppli* 
ers  who  may.  Finding  them  may 
bedtfflcylt,  but  there  will  be  real 
joy  in  the  eyes  when  they  detail 
the  way  to  deal  with  a  problem. 
Want  to  spend  a  liltie  more 
money?  How  about  a  low-priced 
demodulator?  Monitors  are 
available  for  thoS0  computer 
nuts  who  are  still  using  convert- 
ed TV  sets.  Other  kinds  of  giz- 
mos are  out  there,  any  of  which 
would  tre  eagerly  received  by  a 
hungry  ham.  Logic  probes, 
breadboard  kits*  and  gift  certifi- 
cates at  a  local  emporium  on  up 
to  hundred-dollar  counters, 
single-board  computers,  and 
disk  drives,  there  is  something 
to  delight  the  ham's  heart  from 
pennies  up.  t  hope  these  sug- 
gestions help. 

Now  let's  pick  up  a  fetter  from 
Wayne  Hail  WB40GM  from  Col- 
orado. Wayne  writes  that  he  has 
acquired  a  MITS  6d0b  micro- 
computer, which  has  all  of  IK  of 
RAM  in  it,  and  wonders  if  there 
is  any  way  to  add  more  memory. 
For  those  who  are  not  familiar 
with  the  6@0b,  thfs  was  a  ma- 
chine that  MITS,  whose  first  ma- 
chine, the  Altair  8800,  started 
this  computer  craze,  brought 
out  to  exploit  the  ihen*new  Mo- 
torola 6800.  Although  it  used  the 
same  CPU  as  the  more-success- 
ful Southwest  Tech  6800  ma- 
chine, it  used  a  bus  unique  to 
itself.  Thus,  neither  S-100 
boards  nor  SS-50  boards  will  fit. 

Well,  this  problem  was  tack- 
led in  an  article  in  Kilobaud 
(thaf  s  all  it  was  called  then!)  in 
its  third  issue,  March,  1977.  !n 
tact,  there  are  two  articles  on 
the  630b  in  that  issue.  The  first, 
by  Anthony  R.  Curtis,  describes 
building  the  SSOb  and  is  a 
sketchy  review  of  the  box.  The 
other  article,  ©nlliied  "Make 
Your  680b  Smarter/'  describes 
the  efforts  of  Sty  Mitchell  and 
Phil  Poole  to  design  and  build  an 
S-1 00  adapter  that  fits  inside  the 
680b  case.  This  allows  the  use 
of  S'100  memory.  Although  an 
8K  board  was  considered  hot 
stuff  back  in  1977  (my,  how  time 
flies),  you  can  gel  quite  a  bit 
more  on  a  board  now.  The  article 
includes  a  printed  circuit  layout 
of  the  board  and  full  details  on 
implementing  the  augmenta- 
tion. 

More  reviews  on  the  way,  with 
whatever  I  can  lay  my  hands  on 
as  the  target.  Reader  questions 
and  more  fun,  here  in  RTTY  Loop 
in  eightyHDne* 


18     73  Magazine  •  December,  1980 


1 


■I  r    r 


'fj^^ 

■^■"f^^ 

^■^  ^^B 

na 

W\Z 

' 

^B9   ^^ 

!J|J 

ffjl 

'^^^L_    ^^^^^^^^^I^B 

^    g|^ 

„     £irl 

^^HL  '     ^^^^^^^^^^^1 

19; 

ah^ 

:r 

LJ  * 


' 

"i 

1  ^  -  f  p 

f 


*4 


I 


^  touch  cf Class 


There  are  those  who  will  only  be  satisfied  with 
the  finest. 

For  these  perfectionists  HAL  Communications  is 
pleased  to  offer  the  DS  3100  Automatic  Send- 
Receive  ASCII,  Baudot  and  Morse  Terminal 

We  cordially  invite  you  to  request  our  catalog. 


m 


HAL  COMMUNiCATIONS  CORR 

Box  365.  Urbana  IL  61801 .  [21 7)  367-7373 


For  our  European  customers,  contact:  RtchterS  Co^  D  3000  Hannover  1  •  Transradh  SA,  6816  Bissonel Lugano  •  Radh  Shack,  itd^, 
London  NW63AY*  Erik  Torpdaht  Teteconi  DK  3660,  Stenlose,  Denmark 


/IIV/IRDS 


BIttGosney  WB7BFK 
2665  North  1250  East 
Whidbey  island 
Oak  Harbor  WA  98277 

FORT  WAYNE  RADIO 
CLUB  AWARD 

This  week,  i  was  pleased  to  re- 
ceive  a  very  nice  letter  from  Ber- 
nard Holm  K9JDF,  who  is  the 
Commynicatiofis  Manager  for 
the  Fort  Wayne  Radio  Club  out 
of  Fort  Wayne,  Indiana.  In  his 
fetter,  Bernard  provided  detatts 
of  an  awards  program  sponsored 
by  their  club  station,  W9TE. 
Here  are  the  award  program 
details. 

To  qualify  for  the  Fort  Wayne 
Radio  Club  Award,  applicants 
within  Allen  County,  Indiana, 
must  work  25  individuai  mem- 
bers of  the  Fort  Wayne  Radio 
Club.  Appticants  located  else- 
where in  the  United  States  must 
work  a  minimum  of  5  Fort  Wayne 
Radio  Ctub  members.  There  are 
no  band  or  mode  restrictions, 
but  all  contacts  must  be  made 
after  January  1, 1979,  to  be  valid. 

To  apply,  prepare  a  list  of 
claimed  contacts  in  order  by 
callsign.  Include  the  name  of  the 
station  operator,  the  date  and 
time  worked  In  GMT,  and  the 
mode  and  band  of  operation. 
Have  this  list  verified  by  at  least 
two  other  amateurs  or  by  a  radio 
club  official,  stating  that  QSL 
cards  were  in  your  possession 
at  the  time  verification  was 
made. 

Enclose  your  application  with 
an  award  fee  of  $1.00  or  2  IRCs 


to:  Fort  Wayne  Radio  Club,  Inc., 
PO  Box  15127,  Fort  Wayne  IN 
46836. 

Last  month,  I  featured  a  cou- 
ple of  awards  from  our  amateur 
friends  jn  Brazil.  Not  realizing 
the  popularity  of  these  pro- 
grams, I  received  two  more  that  I 
would  like  to  share  with  you 
now. 

GPCW  AWARD  FROM  BRAZIL 

Sponsored  by  the  Grupo 
Pfaiano  de  CW,  this  award  is 
made  available  to  amateur  oper- 
ators throughout  the  world. 

To  qualify  for  the  GPCW 
award,  applicants  must  estab- 
lish two-way  contacts  with  at 
least  5  members  of  the  Group. 
These  contacts  must  have  been 
made  after  November  5, 1973,  to 
be  valid.  All  authorized  amateur 
bands  may  be  utilized,  but  only 
CW  contacts  with  a  minimum  re- 
port of  338  may  be  claimed. 

To  apply,  prepare  your  list  of 
contacts,  listing  the  usual  log- 
book information,  and  have  it 
authenticated  by  a  local  radio 
club  or  at  least  two  fellow  ama- 
teurs. Enclose  your  application 
with  at  least  5  IRCs  to:  GPCW, 
Box  556,  11100  -  Santos,  Brasil, 
South  America. 

GPCW  members  who  qualify 
as  contacts  are:  PY2ARX,  BBO, 
BKT,  BOP,  CE,  CJW,  CSI,  CYE, 
CZL,  DBU,  DHP  (YL),  DYX,  EQR, 
EW,  EWB.  FYF,  EXD,  FDO,  FNB, 
FPE,  FRW,  GUN,  GYJ,  RG,  TT, 
YON,  ZY,  and  PY IDG/2. 


T^r^jgn  iHfrK:--^x&ii^  sia^jM  Twig 

PRESENT   jai^  •JtiSARE'  T{>  AllAfEUS 


AN  OPEN  LETTER  TO  CLUBS  AND  ORGANIZATIONS 

Each  year,  literally  thousands  inourfraternlty  of  radio  ama- 
teurs seek  ultimate  recognition  by  accomplishing  the  many 
levels  of  operating  excellence.  And,  thus,  "award  hunting" 
has  become  a  unique  aspect  in  amateur  radio  operation. 

To  achieve  the  many  goals  established  by  them,  amateurs 
rely  almost  entirely  on  publications  such  as  73  Magazine  to 
Inform  them  of  the  various  award  incentives.  Each  month,  I 
dedicate  a  special  multi-page  Awards  column  to  over  150,000 
readers  throughout  the  world.  With  every  edition,  this  figure 
grows. 

Should  your  own  organization  have  an  awards  program,  I 
would  like  to  extend  a  personal  invitation  for  you  to  share  its 
contents  with  our  many  readers.  What  an  excellent  opportuni- 
ty this  will  be  for  you  to  gain  worldwide  recognition  at  abso- 
lutely  no  cost  to  yoy  whatsoever! 

To  obtain  this  free  service,  please  forward  1}  rules  for  each 
award  being  offered  and  2)  a  sample  copy  of  each  award  cer- 
tificate. 

Perhaps  your  organization  doesn^t  have  an  awards  pro- 
gram yet?  Allow  me  to  encourage  your  officers  to  consider 
such  an  endeavor.  Not  only  will  it  bring  immediate  recogni- 
tion, but  (t  can  serve  as  a  reliable  source  of  revenue  for  your 
organization. 

Good  luck  and  my  sincere  thanks  for  your  dedicated  sup- 
port!— Bill  Gosney  WB7BFK 


SAf  i>f 


I^JTWEiJEP  S^' 


fFI^IFTCJlTI:*. 


PPC  AWARD  FROM  BRAZIL 

Radio  amateurs  the  world 
over  are  invited  to  become  eiigi- 
ble  for  the  PPC  Award,  some- 
times referred  to  as  the  "Carioca 
Woodpecker's  Award/' 

To  qualify,  applicants  are  re- 
quired to  establish  two-way  CW 
contact  with  different  PPC 
members.  Brazilian  amateurs 
must  make  10  contacts,  while 
amateur  operators  located  out- 
side the  country  of  Brazil  must 
conduct  5  individual  QSOs  on 
the  CW  bands. 

To  be  valid,  all  contacts  must 
be  made  after  March  1,  1965, 
which  is  hailed  as  Rio  de  Janei- 
ro's 4th  centenary.  A  minimum 
signal  report  of  338  must  have 
been  logged  for  each  claimed 
contact. 

To  apply  for  the  PPC  Award, 
have  your  contacts  verified  by  at 
least  two  fellow  amateurs  or  by 
a  radio  club  official.  Enclose 
this  list  along  with  an  award  fee 
of  5  IRCs  addressed  to:  PPC  Bu- 
reau, PO  Box  2675,  20000  Rio  de 
Janeiro,  RJ,  Brazil,  South  Ameri- 
ca. 

This  award  also  may  be  earned 
by  SWLs  and  the  same  rules  ap- 
ply, 

PPC  members  are:  PY1AFA, 
ARS,  AW,  AZ,  BHO,  BIR,  BLG, 
BOA.  CBW,  CC,  CCE,  CFS,  CIP, 
CMT,  CTP,  DDI,  DMZ,  DNU  DNS, 
DOG,  DUB,  DUJ  (YL),  EFX,  EHF 
(YL),  EHN,  EIR,  HO,  JN,  KO,  LA, 
LG,  MB,  RJ,  SJ  (YL),  PY2EW, 
PY2FWT,     PY2RG,    PY4CZ, 


PY6HL,  PY7CGV  (YL),  and  the 
following  list  of  Silent  Keys: 
PY1AIF  (1966),  PY1BX0  (1968), 
PY1DB  (1977),  PY1TC  (1977),  and 
PY1DNN  (1977). 

Traveling  abroad,  we  learn  of 
a  very  chattenging  award  from 
Sardinia.  At  least  from  a  DXer's 
standpoint  on  the  west  coast  of 
the  states,  this  one  ain't  easy, 
my  friendl 

GOLD  SARDINIA  AWARD 

Sponsored  by  the  URS  Club  of 
Sassari,  Sardinia,  the  Gold  Sar- 
dinia Award  is  granted  to  any  li- 
censed amateur  or  shortwave 
listener  who  has  made  contact 
with  or  heard  stations  in  Sardin- 
ia since  January  1,  1976. 

To  qualify,  European  appli- 
cants must  accumulate  a  total 
of  20  points,  while  amateurs  out- 
side Europe  must  gather  15 
points  total.  The  points  are  fig- 
ured this  way;  Each  contact  with 
a  URS  Club  member  counts  4 
points  on  HF  and  5  points  on  the 
VHF  bands.  A  contact  with 
JSQLYN  counts  6  points  regard- 
less of  the  band.  All  other  Sar- 
dinian contacts  count  1  point  on 
the  HF  bands  and  2  points  on 
the  VHF  bands.  The  same  sta- 
tion may  be  worked  on  the  same 
band  on  different  days  or  the 
same  day  on  different  bands  for 
award  credit.  For  example, 
should  you  be  fortunate  enough 
to  work  ISOLYN   on  all  three 

Continued  on  page  783 


20     73  M^g^zino  •  December,  1980 


Count  on  DSI  Frequency 


Counters  w  deliver 

•  Accuracy  Sensitivity  High 
Resolution  and  Reliability 

•  Meeting  All  FCC  Regulations 


CheclKing  a  9£0  Ml-ii  transmitter.  Servicine  m  TV  (unof^  VTR^  CaHbratrng 
mfitrumemalEon:  M^asunng  PiL  siflnals.  Reading  a  Pi.  ot  iudiO  Signal  Xq 
l/lCXKIth  of  a  H?(Model5  CI  200,  B700  only}  — Whalflver  your  needs  — 
DSI  s  1.2  GHz  Models  5700,  CI  200  or  1  GHz  Model  6510  or  512  MHjj 
Modal  &5Q0  are  sure  la  provide  the  accuracy,  sensiitivity  and  HeAibrHty 
r  eq  u  If  ed  io  m  eet  yo  ur  most  si  r  i  rigeni  cr  tier  is  Al  I  CI  200  cou  n  ter  &  j  nol  ude 
1/lD00t^  Hf  capabilitv  and  a  variable  sensitivrty  control  fResolve 
1/tOOOth  of  B  H;  wiTh  v^ur  5700  by  adding  opiion  AM57  ■  Audio 
Multiplier  )  The  5500  series  are  compact  and  portable  encf  use  a  TCXQ 
lime  bes«,  white  ihe  &70Car%dC1 200dffer  iaboraiory  standard  oven  tiine 
bas*  oscillators  Ponabiiiry  is  improwd  on  ail  models  wrth  the  addition  of 
|h#  ri^hargeabfe  NiCad  battary  padt  whicb  mctudcs  AC  batt 
ehmknvtor/AC5  All  051  nrwdels  will  operate  o<n  0  Io  14  5  VDC.  and 
inc^ut^  £0  Dihm  andt  1  Me^)  BHC  inputs  Join  the  growing  ranks  df  tens  of 
thousands  of  sat  iff  led  customers  who  ha  v?  discovered  thai  OSl  offers  the 
but  prrce  to  quatny  ^eaiures  ratio  m  the  tndusny^ 


kAnpi^i   ri'?!^   $269.95 

BUILT-IN  AUDiO  MULTiPLiER 

1/1000  Hz  RESOLUTION  ON  AUDIO 

50  Hz  -  1.2  GHz 


'  "ODEL  5500 
50  Hz  —  512  MHz 

I11S.95 

MODEL  5510 
SO  Hz  to  1,0  GHz 

$139,95 


WdOflL 


%^Q0 


•700 


01300 


FIlEa 
KAIiOE 


to 

Era  MH» 


60  Hi 

to 
t  2GNt 


bOHi 

Io 
12  GHi 


OF 


TCXO 


ovun 


own 


accuhacv  oviit 
_jriMyEBAnjWE 


M"^     M"  c 


X  1  ppm 


1  2^ni 


i    1  PO' 


y  -  #y  c 


^3  ppm 


±  1  ppm 


t   6  ppm 


»gii>mvmf  TY» 


ICWMi 


1& 


Jfi_U:L 


3f  MHz 

to  - 


10 

10 
25  Mv 


IE 


20  Mv 


10 


20  Mv 


10 


IB  t^ 


IBOMHi 

to  - 
•  12  JMlrti 


20 


7BMv 


t5 


60"^ 


15 


SO  Mv 


NO, 

or 

glflJTL. 


e 


» 


% 


fiiiOLimoM 

»0  Hi  10  MIti 
AUDIO  FItia            ro  to 

umma  icALta    m  mmz  i  a  Qite 


N/A 


SAME  At 

CI 200  WITH 
OFT  AMB7 


.001  Ki 
Stri 


1  Hi 


,t  Hz 


I  Hi 


10  Hi 


10Hi 


10  He 


MODEL  5700 

50  Hz-  1.2  GHz    189.95 


NOTE   ^h  Dtdit-Overnow  1 


NOTE:  Piric«  Bfid/Df  Bp*cMK«(»or>a  Hr*  »ubi«ci  io  ih^t^d*  wrti^Out  nottOfl  Of  otAi^mtion  by  dSt  tnstrum^mt.  /lie  Pleat*  «dd  1 0%  to  a  mmfmum  ol  •  1 0  DO  for 
shii^ng.  handfing  and  miuran^cr  Ordvrs  ouisMte  cyf  US  A  ft  Car>MSa.p1aa:se  add  an  Kldilional  (20.00  to  cov«f  airshi(Mn«nt  Caiifbmia  residents  adtf  6%  tahistaK, 

AIMS  7 


To  Order 
Call 


1 


SSOOBAC 139  95 

SSOO    . 11996 

C1200  ,,,.,„.,;,„......*...*,.  2^95 


1-    i    ■■     fa 


V9»i-l-i*ft 


BA^NI  CAD-W/A  bS 
BA'57    ...,*^.,.,,,,,,. 
AC-9    ... 

T'^OO 


34  95 

,  o.vS 
695 
B95 


Toll  Free   800*854*  2049  OS/  iNSTBUMENTS  INC.  95SO  Chesapeake  Dr  San  Drt^^.  CA  92123   •   (714)  505^402 


*^20 


See  Your  Local  Authorized  DSf  Dealer 


Ajn«lTUfi4ei 
R'lv'"'  1    bill-  1 1^ J ^f 

Ask  a#^l«  Supply 

h  ■■  im    *,l  J52J3 

AiijNMe 

PN7#>n.i    A/SSOOt 


•i'»«a^7-3tt 


i»eti**Tj 


CA  4S731 


CeMiH 

5v  JcMd  C«  9ftt» 
AQt-nrnai    40S-297-7S30 


CM] 

I  ^'''jc  L  Pifiia  »'[* 

Wital  LtM  J^^^  CA  WXI&4 

^1)1^4  Ml  I  nil  [ir  Rd   ia>l 
San  Dmud  CA  93t2f 

?M■^7rt■lr^?4 
M^flfv  a«i0i« 

a^i  H  £wci>aJWe 
AntMM.  ^  f  ZaOt 


1  I-'*  *i  *' 


rtQQl 


C«AI 

Ui^  tmiA  CA  Maia 


La*  OhIc  CA  t3«S 

Til  Caiji 

IS4M  lM«ii  A..i> 
Sin  Jim*  CA  VS  3  iA 


Cf\9fokmm  t[*tH   S  CnHnrn- 
Ql'ua  Mpigjhfl,  CAfiiftlC 

Coinni.  UnlJmJttd 
D^'ivfi  coeosM 

Wttiii  >  [  iMOl 


AflU  Suv 


a^ei.1. 
ia«9 


Si 


iHil'A^flT 


6l2E«VllnStt««f 
30S^M^«ft» 

T747-17d9l>iar»Si 

iiir:«1id4««><M«  FL  37206 
904,]S3'7AII1 

a '  .1  -fcttW  Ji  1  fi  1 
^  i  0  Oiftn&vM^ 

Hrami  fL  JJIJCl 


15aoySl«Sawfn 

Cl|g>iilili  *l  13&IS 

3DS«|l^SAd 


riLjaiir 


ta«0  Wkil  33nd  St  fhmiB 
Hifllsah  FL  73012 

::ioS'ftii7'2?03 


W«ii  lniii««  Umin 

fiaa  WeS'  Jfiitr  3-1 

Com-Tvc  Abi^C. 

21  g  Hrhr4k-nt  Ave  lUtH 

Tiiu5„iihfi  FL  njrao 

3Q5-?fir&4Si3 

^iitt't  2-mr 
s^i^fki  OA  jooao 

Sfri  Dwf  1^  Id 
AHwita  QA  3030* 


la&y  D  So 
Honott«v  HI  Mai « 


HcH9  I>«trib«iftnif 

73  S  SIL«* 

2CIIN152-OS]0 


OrKHht  Pm^tana  4?4t&l 
it?-8fl5  3'4M 

ENekiQA  Comm. 

sif-^Si'^i^i 
Flayd  Ei*etfOf>t4ft 

C{iilm«vi]ki   ILU334 
-TtJ  631  5ief 

SpiEfnMMe*.  Inc 
1009  Q*i1w4a  Si 

o«K  R»(%  n  eo»« 
3t^-aABi4^/7 


'lt*nvp«  C«f '.  19 


^4^740 


PI.  aufha C«lii»ai!»f 


206  IM^hiiifitT  Ad 


if«rT'47nf 

Cam  Cantar 

1*  Fan  Mead  Row] 

Liural.  MD  »^10 

^1-707-O6OO 

1  1305  gl^i'i  !S1 

Hoopw  Eitae.  Siipi. 

Brfoii.USS&Ul 
a01^«32H3i5B4 


Ma#  'Twt 

iarirv  ElVClTtMtlin 
aif  BrcMdway 

N«»YQ*li.  NY  10012 

2t3-a^&-roDo 

Com  m .  Ta<ih .  Qrau  p 

Orean'Sidt.  ISIV  1 1  &79 
61tSafrS?2'i 

Cavaltara  Elac. 
f  S3C  e4th  Server 

1^4  E  44in& 

Him  ram  MV  lOOia 


PiirciHaf* 

1^  Jl«t»r   W4A104 


ia»t 


tCOrdSE  Np 


4p!l  BrkA  Stfeet 
MV  1}«<« 


eYf-42«^?||7S 


34a2  Rnnoprt  An*  H 

■Tid^ani 

Sr  Louia   MO  031.44 
3*4  46 1  9990 

llliaoiirk  Comin  Syiltmi  Inc 

Parkvil1&,  MOfiti^^ 

Habartt  Hk  EI*c. 

405  £    l91hAv« 

91FV^7  1-4149 

btum  El*c. 

flflnvunl.  4AO  6JHiH 
3t4««3f-1444 
HtfiacHuaatti 
PteTBiii's  Ciac, 

aotr  ^si 


l09iMi«A*e 
«dOi25-*4^  i17l«.|3K> 


nr^&mnu  nv  mi 

UWtKil.MAfll^aO 

9l] 


Ml  nad0  la^ 


1074  PiP^sn  Art 

Vkdv'a  €!«£. 

500  Eaar  M«in  Stf«a| 

Purttinn  NC^7T|>1 

AAiaraur  Elact.  Sup. 

^dfidO  EydKl  Ave 
W^rNtille.  OH  440^2 

Ouaan  cinr  eik. 
7404  Mamillon  Ava 
ClWinryil.    OH  45331 

UnJvanal  AmalaHr 

t2IIO  AidAOftH! 
QfrnoUsixiFg  OH 
430Bfl 
«t4'17J4ttS7 


Kadwl  TV 

WvKEtti  OH  45750 
fi14  373-i9fl7 


314  LwtSi 


»37  EdomndtK 
UiKn.  OK  73180 
405^794pOiOB 


DBfrtOC 

714  W  P(«nogKa 
fro»«n  A<tt7«,  OlC  740^1 1 
•t«^;$i  93^ 


IMteiVlt# 

Ontaha  Amal  Cantar 

2ai«ai?a4||aSlrB8t 
Omiha.  HE  &Bl3i 
4C]3-34B'iia::iia 

Hrnvrnd* 

Amteaur  Eiac,  Sup, 
107?  N   FLinc^o  Di 
L»i^V«OilL  NVeSIDB 
rt)ie*f-:i^  14 

Mttw  HttmpMtttm 

n  uAnitaasei^jvnc 

Concaid  NHDUDI 

aa>7j4.9Hi 


Of^ft'UO 


4«1  Ml' 


Hl*ip  SaJvi 

Ona73?t 

i 


hK  "Ham'  auw^ar 
A4  NKtrlft  Vort  noad 

714 


40J4  aFa«nivllle  Rd. 
Trrwrnm   PA  T9Q4T 
4Q0-53JQ33Ei 

^fKVtf*  H  iJMtf 

DAN  CDinmtfnicationt 

1ttil4SmUJi3l. 
Na  Novl-C>«rH:#,  HI 
4Dt-23T-iS«3 

A  i  Q  E^adronica 

Rdu1«  3  Aye<M]al«  Of 

«03-iH^A330 


lOOflFatnif^iad 
{i»«a&iv««  $C»A4a 


716T 


OH 


mmoi.  TH  tr*30 

«l$^r»4^ti«qti 


S4r*-nQ««  ip«<Tcar 

i4«a  witi%  siaiion 
M«mF9h.ia,  rN:3aii7 
501  edj-iiiise 

faiaa 

Amalawr  A  ClHIim.  Clac. 

R   A'Dith.  TKTA133 
ai7  794-tBQt 

SiZ  3Ji"i1  IO 

4i444.  PF04f  H4M 
flM  Bwd  Airfiori  am 
OlHU   Tl  7bflS 

114  3^7-434 

*SOS 

HamtOKLTM  7TQ09 


t'fOiOhiawDi 

Ti  mm 


ttu 


Afp44Tl 

J7l]  CrMHtieil  Ci 

ImffQ.  rHTMtU 
3t4Z45H||!9ia3 

BAT  f  lacti4<1ic* 

10457  9««i«eiMa 
ei  p*io  rx  7M£<h 

inwifin'* 

Elac. Equip   ftanfc 
5ie*Miil3l   ME 
Vlei^rFA  VA391HO 
703-938-331 WJ 

RaidtP  CiHnpn 

31  1  SMj-nantftiMh  A-r. 
Raano^t  VA  2401S 
7aS-J4?nSJ!3 

Tha  Tunad  Clfcuil 
7A«  £  lAif^eHi  S<r 

VA  33001 


nm 


rt&  t  NMw  bMa  Rd 
H^itafitf  terwv  VA  7aE>7$ 
BfH'Tjr'SiQO 


•  1&4 


4S3S  W  FoM  Chi  LK 

l«ilw«M*#«  Wl  s^ta 

414-44:?  4700 

RaifQar  Clae. 
La  Grc44i>.  W 
«(»4&3-J530 


Fofflign  Oaalari 


Carvlro  1nairum«nlal  Clactronieo  SA 

AVDA 'rHJ«Dnndt<ii'.:ia  1HW; 
127S  BL#*fto|  A4r«a 
AJQOIItftN 

FuvFlv  fttco 
R»d»9  Cofflflt. 

San  Juan  P  It  OMOl 


1 


fi'tej 


Heohcif^  9 


Se'iHimaBiiicH  3lt.  9S 
4<]K]K  Efknmi' 2 
M^Hl  Gef rncnr 

SmtQutm 

HCR  EJaclfonlcB 

C^au^soo  Da  Mivallaft  100 
1420  Bran  e  t'Mmutf 
Bal^ium 


n 


^ 


I 


lem  LINES 


Dave  Mann  K2AGZ 
3  Daniel  Lane 
Kinnelon  NJ  07405 

Tired  of  knocking  your  brains 
out  in  DX  piieyps?  Frustrated  by 
the  sheer  idiocy  of  aeif-ap* 
pointed  monitors  and  vigilantes 
who  congregate  on  the  DX  sta- 
tion's exact  frequency  and  QRM 
the  action  with  bickering  and 
other  abuse?  Turned  off  by 
selfish  operators  who  either 
refuse  to  abide  by  the  DX  sta- 
tion's instructions  or  who  don*t 
bottler  to  listen  to  them  in  the 
first  place? 

If  any  or  all  of  these  examples 
fit  your  present  frame  of  mtnd 
toward  OX  chasing,  I  may  have  a 
solution  for  you.  It  may  not  put 
you  on  the  Honor  Roll,  but  it  will 
afford  you  the  satisfaction 
which  comes  from  genuine  ac> 
compllshment.  But  let  me  tell 
you  of  the  circumstances  which 
led  to  the  Idea. 

When  I  finally  made  the  cov- 
eted Honor  Roll  after  years  of 
dedicated  effort^  I  was  faced 
with  a  gloomy  prospect.  I'd 
grown  so  used  to  chasing  DX 
that  I'd  become  bored  with  other 
facets  of  the  hobby.  DX  had  be- 
come the  ne  plus  uftra,  and  it 
was  all  I  thought  about  In  con- 
nection with  ham  radto.  This 
feeling  of  dreariness  devolved 
out  of  the  realization  that  oniy 
four  countries  remained  on  my 
want  list,  and  while  there  did  ex- 
ist some  slight  possibilities  that 
those  four  would  eventuaily  be 
activated,  this  did  not  appear 
likely  in  the  immediate  future. 

I  had  to  find  some  new  inter- 
est to  take  the  place  of  DX;  this 
was  clear. 

Never  much  of  a  constructor,  I 
couldn^t  envision  starting  to 
buiid  at  this  tate  date.  That  pos- 
sibility was  out 

Slow  scan  television  and 
moonbounce  had  never  "put 
bubbles  in  my  blood/'  nor  had 
amateur  satellite  communica' 


tions.  Mind  you,  I  do  not  criticize 
them.  But  they  are  just  not  my 
cup  of  tea. 

t  had  never  enjoyed  participa- 
tion in  traffic  nets,  and  with  the 
exception  of  a  few  years  of 
MARS  activity;  I  was  not  overly 
attracted  to  the  prospect.  (1  be- 
lieve that  my  distaste  was  in- 
spired by  one  of  those  simulated 
emergencies  back  in  the  60s, 
when,  as  part  of  an  AREC  group 
which  Vd  joined,  1  observed  one 
of  my  colleagues  calling  Net 
Control  with  the  astonishing 
news  that  Yonkers,  New  York, 
had  been  hit  simultaneously 
with  a  devastating  nuclear  at- 
tack and  a  choiera  epidemic.  I 
threw  up  my  hands.) 

No!  The  sudden  and  abrupt 
realization  that  DX  was  about  to 
tiecome  a  thing  of  the  past  for 
me  was  a  shock.  And  I  could  not 
find  a  way  to  cope  with  it. 

Then  one  day  an  Inspiration 
hit  me  like  a  bolt  out  of  the  blue.  I 
was  idly  thumbing  through  the 
Catfbook,  and  my  eye  was  sud- 
denly captured  by  one  of  those 
special  entries;  you  know  the 
sort  I  mean... the  listing  was 
separated  from  ail  the  others 
and  printed  In  bold  type.  And 
this  particular  callsign  had  the 
same  suffix  as  my  own.  I  had 
never  worked  anyone  with  my 
own  suffix,  and  I  thought  it 
might  be  nice  to  hook  up  with  a 
few  and  to  exchange  QSLs.  I  be- 
gan writing  down  In  my  note- 
book the  prefixes  of  the  various 
AGZ  stations,  and  I  started 
listening  for  them  on  the  air. 
Eventually  I  latched  on  to  a  cou- 
ple^  The  first  was  KOAGZ,  and 
others  followed  after  a  few 
months. 

t  even  ran  into  a  few  foreign 
ones,  and  this  prornpted  me  to 
investigate  the  possibility  of 
writing  to  several  and  proposing 
on-the-air  schedules.  They  were 
all  over  the  map,  In  all  countries. 
For  the  most  part,  they  showed 
up  at  the  suggested  time  and 
frequency;  we  established  con- 
tact and  ultimately  exchanged 
cards.  In  some  cases,  we  have 
continued  to  meet  on  a  regular 
basis  ever  since  the  first  con- 
tact. 

To  shorten  the  story,  I  now 
have  over  75  AGZ  cards,  and  Tm 
sure  that  I  will  eventually  have 
100  of  them. 


The  best  part  of  this,  of 
course,  is  that  notwithstanding 
the  fact  that  ail  the  other  AGZ 
stations  are  desirable  from  my 
point  of  view,  there  is  absolutely 
no  competition  from  anyone 
eise.  1  don't  have  to  worry  about 
pileups  or  the  loonies  who  have 
begun  to  make  a  shambles  and 
fiasco  out  of  DX.  I  can  chase 
AGZs  to  my  heart's  content,  and 
there's  not  another  soul  who's 
going  to  give  me  a  hard  time. 
Others  with  my  suffix  seem  just 
as  desirous  of  working  me,  and 
there  hasn't  been  a  single  in- 
stance of  QSL  difficulty:  The 
cards  generally  arrive  by  the 
quickest  route. 

Some  are  in  Europe,  some  are 
In  South  America;  there  are 
many  in  Canada  and  in  the  An- 
tipodes. 1  have  quite  a  few  from 
the  West  Indies  and  from  Africa, 
And,  as  I  mentioned,  it's  my  own 
game  and  I  can  play  it  to  my 
heart's  content.  The  only  limits 
are  dictated  by  my  own  energy 
and  willingness  to  exert  myself, 

I  found  that  whenever  I  men- 
tioned this  activity,  it  seemed  to 
elicit  interest  among  others. 
And  the  thought  occurred  that 
this  might  be  a  new  and  differ- 
ent radio-spofi  that  could  be 
adopted  by  others  who  may 
have  become  bored  with  the 
usual  and  commonplace  and 
are  looking  for  a  novel  and 
unique  pursuit, 

I  thought:  Suppose  the  game 
could  be  organ lEed,  with  certifi- 
cates, endorsements,  annual 
listings,  and  the  like?  Suppose  it 
were  possible  to  send  out  a 
computer  printout  of  every  ap- 
plicant's callsign  counterparts 
throughout  the  world,  together 
with  mailing  addresses?  And 
suppose  there  were  a  quarterly 
newsletter  listing  standings, 
profiles  of  the  top  contenders, 
and  the  like?  And  suppose  there 
were  special  awards  fof  multi- 
band  and  multi-mode? 

The  idea  began  to  feel  excit- 
ing. In  sounding  out  friends,  I 
found  more  than  casual  inter- 
est. I  had  the  feeling  that  per* 
haps  it  might  meet  with  general 
enthusiasm,  both  here  and 
abroad.  Why  not? 

The  only  fly  in  the  oi nlment,  of 
course,  is  that  if  all  these  sup- 
plementary adjuncts  were  to  be 
incorpofated  in  the  game,  it 
would  cost  some  initial  money 
to  get  the  thing  off  the  ground. 
The  printing  of  a  suitable  certifi* 
cate  would  be  costly,  and  the 
computer  readout  would  cost 
several  bucks  as  well  While  an 


awards  program  can  be  man- 
aged at  minimal  cost,  it  cannot 
be  done  for  peanuts.  Perhaps 
the  applicants  themselves 
wouid  be  willing  to  help  to 
underwrite  these  costs  by  pay- 
ing a  moderate  fee  of,  say,  five 
dollars  or  some  equally  modest 
sum.  No  one  would  get  rich  on 
the  proceeds,  that  is  certain.  But 
no  one  would  go  broke  either. 

What  to  call  the  award?  How 
about  WYOS,  Work  Your  Own 
Suffix?  Not  loo  bad.  But  per- 
haps it  would  be  better  if  the  ini^ 
tiats  formed  an  acronym  such 
as  do  VISTA,  Volunteers  In  Sef- 
vice  To  America,  or  NOW,  the 
National  Organization  for 
Women.  Unfortunately,  my 
background  as  a  professional 
songwriter  and  creator  of  com* 
edy  material  invariably  bubbles 
to  the  surface,  and  I  find  that  ev- 
ery acronym  that  occurs  to  my 
mind  turns  out  to  be  a  four-letter 
word  of  Questionable  taste. 
Amateur  Suffix  Society,  Call- 
sign  Radio  Amateur. .  .oh,  well, 
you  get  the  idea,  Vm  sure.  Out 
there  in  the  vastness  of  ham  ra- 
dio land,  there  are  enterprising 
and  creative  minds;  there  must 
be  someone  who  can  come  up 
with  a  unique  name  in  keeping 
with  the  spirit  of  the  thing. 

But  please,  I  beg  you,  don't 
send  in  your  suggestions  at  this 
time.  And  don't  send  in  any  ap- 
plications or  money.  If  and  when 
the  program  is  inaugurated,  an 
appropriate  announcement  will 
be  made  in  this  space.  In  the 
meantime,  I  urge  you  to  try  chas- 
ing your  own  suffix  in  the  same 
way  that  I  do.,. on  your  own 
and  at  your  own  pace.  There's 
no  reason  why  you  should  have 
to  wait  for  this  activity  to  be  or- 
ganized. 

In  fact,  it  might  be  better  if  it 
remained  an  off-the-cuff  thing 
without  att  the  hoopla  of  certifi- 
cates and  competition  of  stand- 
ings and  listings.  Since  there  is 
no  competition  In  it  now,  why  in- 
troduce it  anyway?  And  if  It  hap- 
pens that  some  of  you  should 
happen  to  amass  a  total  which 
you  think  unusualiy  high,  you 
might  let  me  know  about  it.  111 
be  happy  to  mention  it  here  so 
that  you  can  gain  the  recogni- 
tion that  the  achievement  de~ 
serves. 

But  let  me  warn  you:  Despite 
the  lack  of  competition,  it  is  not 
the  easiest  thing  in  the  world  to 
accomplish.  It  will  take  dedica- 
tion  and  persistence. 

Go  to  It,  and  the  very  t>est  of 
luck  to  you  alL 


22     73  Magazine  •  December,  1980 


THE  GIANT 


COMPANY 


k 


REVOLUTIONIZES  THE  STATE  OF  THE  ART 


Wl 


AND 


INTRODUCE  THE  BRILLIANT  NEW  PCS-2000 


NOT  $550.00 

FALL 
SALE 


MICROCOMPUTER 
CONTROLLED 

SUPERIOR  COMMERCIAL  GRADE 
2  METER  FM  TRANSCEIVER 


NOT  $550  00 

FALL 
SALE 


REG.  $369.00 


1  M  ■  V 


REG.  $369.00 


ill 


pciMm    iT  C  Zi^  *"# 

—  U  D  C  U 

•  • « ft  • 

-     sjr  Kr"  ^-  ■ 

1            ^^                •-*                   Ajr 

ttt/Kt         «»*            »* 

V 

V 

*    <* 

Wiftft            I*               41 

% 

ymn^ 


CM4  «A4i 


hf!*^ 


I 


COMPARE  THESE  FEATURES  WITH  ANY  UNIT  AT  ANY  PRICE 


FREQUENCY  RANGE:  Receive  and  transmit:  144.00  to  147.995  MHz. 

SKtri^lepS  +  MARS'CAP  CAPABiLITY  BUILT  IN  1142-149,995  MHz). 

ALL  SOLID  STATE^PyiOS  PL  DJGfTAL  SYNTHESIZED. 

SIZE:   UNBELIEVABLE!  ONtY  6  3/4"  X  2  3/0"  K  9  3/4".  COMPARE! 

MICROCOMPUTER  CONTROLLED:  All  scanning  and  frequency-control 

functions  are  performed  by  microcomputer. 

DETACHABLE  HEAD:  The  control  head  may  be  separated  rrom  the  radio 

lor  use  in  limited  spaces  and  for  security  purposes. 

SIX-CHANNEL  MEMORY^  Each  memory  is  re-pro§rammat)le.  Memory  is 

retained  even  when  the  unit  k%  turned  off. 

MEMORY  SCAN:  The  six  channels  may  be  scanned  In  either  the  ^^busy"* 

or  ^Vacant"  modes  for  quick,  easy  location  of  an  occupied  or  unoccupied 

frequency,  AUTO  RESUME.  COMPAREj 

FULL-BAND  SCAN:  All  channels  may  be  scanned  in  either  "busy"  or 

"vacant"  mode.  This  is  especially  useful  for  locating  repeater  frequencies 

in  an  unfamiNar  area.  AUTO  RESUME,  COMPARE! 

INSTANT  MEMORY'1  RECALL:  By  pressing  a  button  on  the  microphone 

or  front  panel,  memory  channel  1  may  be  recalled  for  Immediate  use. 

M1C-CONTROLLED  VOLUME  AND  SQUELCH:  Volume  and  squelch  can 

beadiusied  from  the  microphone  for  convenience  in  mobile  operation. 

ADDITIONAL  OFFSETS:   Provides  three  additional  offset  values:  ^0.4 

MHi,  +1  MHz  and +1.6  MHz.  Other  offsets  may  also  be  obtained, 

25  WATTS  OUTPUT:  Also  5  watts  low  power  tof  short-distance  commun- 


ication. 

DIGITAL  S/RF  METER :LEDS  Indicate  signal  strength  ^n6  power  output. 

No  more  mechanical  meter  movements  to  fall  apart* 

LARGE     ^^-INCH     LED     DISPLAY:     Easy-to-read     frequency    display 

minimizes  "eyes-off-the-road"  time. 

PUSHBUTTON  FREQUENCY  CONTROL  FROM  MIC  OR  FRONT  PANEL: 

Any  frequency  may  be  selected  by  pressing  a  microphone  or  fronl^panei 

switch. 

SUPERIOR  RECEIVER  SENSiTIVITY:   0.28  uV  for  20-dB  quieting.  The 

squelch  sensitivity  is  superb  requiring  (ess  than  0,1   uV   to  open.  The 

receiver  radio  circuits  are  designed  and  built  to  exacting  specifications, 

resulting  in  unsurpassed  received-signal  Intelligibility, 

TRUE  FM,  NOT  PHASE  MODULATION:   Transmitted  audio  quality  is 

optimized  by  the  same  high  standard  of  design  and  construction  as  is 

found  in  the  receiver.  The  microphone  amplifier  and  compression  circuits 

offer  intelllglbllHy  second  to  none, 

OTHER    FEATURES:    Dynamic    Microphone,   built   In   speaker,   mobile 

mounting  bracket,  external  remote  speaker  jack  {head  and  radio)  and 

much,  much  more^  AM  cords^  p^ugs,  fuses^  microphone  hangerj  etc. 

included.  WeJght:  6  lbs. 

ACCESSORIES:    15*  REMOTE  CABLE $35.00     CS^R    A/C  POWER 

SUPPLY... ..$49. 95.  TOUCHTONE       MJC,       KIT S39.95. 

EXTERKAL  SPEAKER $18.00. 


AMATEUR-WHOLESALE  ELECTRONICS  order  now  toll  free 


8817  S.W.  129th  Terrace,  Miami,  Florida  33176 
Telepfione  (305)  233-3631  •  Telex:  80-3356 

H Oiifs:  S*S  M  on.-F  ri.  ^  5 

U.S.  DISTRIBUTOR 

DEALER  INQUIRIES  INVITED 


LETTERS 


Gf 


LEARNING  THE  CODE 


I  just  wanted  to  drop  you  a 
quick  note  to  say  how  much 
your  73  code  course  helped  me.  I 
have  sporadtcdlly  attempted  to 
get  my  ticket  tor  seven  years 
now.  The  theory  is  no  problem  (I 
tiave  a  commercial  Isl  ptione 
and  have  worked  in  RF  for  five 
years),  but  that  code  practice 
would  get  me  every  time,  I  tried 
manuals  and  the  ARRL  code 
course,  but  I  would  memorize 
the  code  sent  on  the  cassettes, 
or,  with  the  manuals,  Td  stay  on 
the  first  few  pages  and  never 
move  on,  until  I  lost  interest. 

I  honestly  can't  say  this  about 
the  r3  cassette,  I  couldn't  mem- 
Oitte  the  code  groups,  and  it  in* 
iToduced  new  ctiaracters  so  fast 
and  furious  that  before  I  knew  it, 
I  was  through  the  whole  alpha- 
bet. 

Anyway,  I  passed  the  exam 
tor  my  Tech  ticket  yesterday,  af- 
ter practicing  with  the  cassette 
for  two  weeks!  Before^  I'd  have 
practiced  for  a  month  or  so 
t>6for6  losing  faith.  Your  co<le 
course  is  great.  Now  HI  work  on 
my  Advanced  ticket  in  my  spare 
time.  Tnx  again! 

Grant  Howes 
Jackson  Ml 

Grant,  you  should  have  started 
with  the  13  per. .  .it's  no  more 
difficutt  to  iearn  the  code  at  that 
speed  than  at  5  wpm,  so  why 
horse  around  and  extend  the 
agony?— Wayne. 


BUT  THEY  WORK 


I  wisti  to  congratulate  you  and 
your  staff  on  a  iob  well  done  re- 
garding your  73  cCMJe  cassettes. 
They  are  indeed  the  most  mir^d- 
boggltng.  frustrating,  teeth- 
gnashing,  high-blood'pressure' 
causing  pieces  of  recorded 
material  I  have  ever  pur- 
chased .  .  .  but  they  work! 

I  used  your  21  wpm  tape  most 
recently  to  help  me  achieve  the 
elusive  Amateur  Extra  class 
ticket.  I  don*t  know  how  many 
times  I  have  personally  told  oth- 
ers of  the  virtues  of  your  cas- 
settes, but  1  firmly  t>eiieve  yours 
are  the  best  on  the  market,  and  I 


have  he&ni  ttom  all. 

\  found  that  after  a  monih  and 
a  tialf  with  your  tapes,  I  could 
copy  plain  English  code  at  bet- 
ter than  25  wpm.  Considering 
that  a  year  and  a  half  ago  I  didn't 
know  a  dit  from  a  dah,  I've  made 
pretty  good  progress. 

I  believe  in  giving  credit  where 
credit  is  due;  therefore,  thank 
you  for  helping  me  to  enjoy  a 
great  hobby.  By  the  way,  your  ad 
states,  "...you'll  almost  fall 
asleep  copying  the  FCC 
stuff, , ."  This  was  not  exactly 
the  case,  but  your  point  is  well 
taken.  Thanks  again. 

Steve  Lewis  KF8G 
Rossford  OH 


[ 


CHRISTMAS  DX 


1 


The  Clark  County  Amateur 
Radio  Club  (Jeffersonville  IN) 
will  go  on  a  DXpedition  to  Beth- 
lehem IN  from  1700  UTC  [Decem- 
ber 13th  until  1700  UTC  Decern- 
ber  14,  1980.  Usmg  the  callsign 
W9WW1/9,  they  will  operate 
phone  on  3,900.  7,235.  14.285, 
21.360,  28.510,  and  147.300  sim- 
plex. Special  Christmas  season 
cards  will  be  sent  to  all  stations 
and  the  envelopes  will  be 
stamped  with  the  unique 
Bethlehem  IN  postal  stamps 
consisting  of  the  Three  Wise 
Men  and  the  Star  of  David.  QSL 
(with  SASE)  to  Clark  County 
Amateur  Radio  Club,  PC  Box 
352,  Jeffersonville  IN  47130. 

JotinW,SheanN9TV 

Jeffersonville  IN 


SATISFACTION 


] 


On  my  return  from  an  extend- 
ed vacation, !  found  the  August 
issue  of  73  Magazine  in  the  mail, 
with  my  articie  ("Over  There")  on 
page  86. 

1  must  compliment  whoever 
was  involved  for  some  very  fine 
editorial  work.  It  is  not  uncom- 
mon these  days  for  a  writer,  in 
looking  at  the  printed  version  of 
his  work,  to  wonder,  "Why  did 
they  slip  those  commas  in 
thereT*  or  *'What  happened  to 
the  last  two  words  of  that  sen* 
tence?*'oreven  "Don't  the  damn 
fools  know  that  'the'  is  spelled 
"t^h-e?' "  But  then,  I  have  fre- 


quently remarked  on  the  quality 
of  the  magazine  and  its  editorial 
standards  in  the  past  few  years. 
Likewise,  I  was  amazed  by  the 
quality  of  the  photo  reproduc- 
tion. The  negatives  are,  of 
course,  close  to  40  years  old. 
The  prints  I  made  late  one  night, 
a  Sunday,  of  course,  when  I 
could  not  get  paper  and  had  on- 
ly a  few  odds  and  ends  of  vari- 
ous grades  left. 

In  all,  I  am  pleased  (and  I 
know  that  you  will  accept  this  in 
the  proper  Hght)  that  73  printed 
the  article. .  .payment  aside,  It 
is  a  source  of  real  satisfaction 
to  an  author  when  everything 
comes  out  right. 

It  may  also  interest  you  to 
know  that  I've  received  two  let- 
ters from  old  friends  who 
learned  of  my  whereabouts  from 
the  piece. 

Julian  N.  iablin  W9fWI 

Skokie  IL 

tt's  nice  to  have  someone  notice 
the  superb  fob  Jack  has  been 
doing  with  the  editing  and  pro^ 
duction  of  the  magazine., . 
thanks  for  the  bouquet.  By  the 
way,  it*s  good  to  get  an  articte 
from  one  of  the  oid  guard  in  New 
York,  t  remember  contacts  and 
seeing  you  at  radio  ctubs  30 
years  ago. — Wayne. 

NOT  ONE? 


GOOD  LORD!!  Wayne  Green 
In  f^ensa  for  20  years??  it's 
strange  I  haven't  agreed  with 
one  73  editorial.  (Congrats.) 

Robert  Roither  WOiFDK 
Florissant  MO 

Alt  of  which  goes  to  prove  that 
brains  and  common  sense  are 
not  necessarily  parattel  endow- 
ments,^ Wayne, 


[ 


HORSE  HOCKEY 


] 


At  the  present  time  I  am  sta- 
tioned with  the  military  in  West 
Germany,  where  we  have  the 
largest  American  population 
outside  the  United  States.  In  the 
past,  the  FCC  has  dispatched 
examiners  to  Germany  twice  a 
year  and  many  individuals  have 
taken  advantage  of  this.  They've 
traveled  from  all  over  Germany 
and  Its  neighboring  countries 
, .  Jhey  came  by  plane,  by  train, 
and  by  car.  Examination  rooms 
were  jam-packed  with  more  peo- 
ple than  you  could  shake  a  stick 
at.  Now,  all  of  a  sudden,  some- 


one in  a  higher  echelon  of  the 
government  decides  that  "ex- 
cessive'* travel  must  come  to  a 
halt.  And  the  result?  Many  peo* 
pie  will  be  denied  the  opportuni- 
ty of  obtaining  or  upgrading  an 
FCC  license  whether  it  t>e  ama- 
teur or  commercial.  It's  a  damn 
shame!  These  same  people  are 
the  ones  putting  their  tives  on 
the  line  defending  this  country 
and  ensuring  thepresen/ation  of 
peace.  As  Colonel  Poller  of 
M'A'S'H  would  say,  "horse 
hockey!" 

Before  I  go  any  further,  let's 
go  back  to  the  bas  ics.  One  of  the 
first  things  we  all  learned  in  our 
study  of  amateur  radio  was  its 
basis  and  purpose.  This  can  be 
found  in  Section  97.1  of  Subpart 
A  of  Part  97,  Listed  there  are 
"five"  principles  of  our  radio  ser- 
vice. To  print  them  here  would 
use  too  much  valuable  space,  so 
I  will  extract  some  of  the  finer 
points  for  you.  Principle  number 
one  talks  about  the  recognition 
and  advancement  of  the  Ama- 
teur Radio  Service  and  emer- 
gency  communications-    Num- 
bers two  and  three  contain  key 
words  such  as  encouragement, 
improvement*  and  advancing 
skills.  Expansion  of  the  existing 
reservoir  of  trained  operators, 
technicians,  and  electronics  ex- 
perts is  outlined  in  number  four. 
And,  finally,  principle  number 
five  mentions  our  unique  abiUty 
to  enhance  international  good- 
will. This  drastic  measure  taken 
by  the  FCC  will  Impede  the  exer- 
cise of  these  very  prlnciplest  It's 
simple  arithmetic. 

As  for  us  here  in  Germany, 
look  under  the  ''Delta  Alpha" 
callsigns  in  the  latest  edition  of 
the  DX  Cafibook.  You  will  find 
approximately  €00  amateurs,  of 
which  85%  are  Americans,  isn't 
this  enough  "clout"  to  warrant 
resumption  of  FCC  testing?  The 
number  GOO  may  not  seem  like 
much,  but  with  our  current  prob* 
lem  of  a  stagnant  growth  rate, 
the  FCC*s  policy  could  show  ad- 
verse affects.  With  dwindling 
numbers  and  no  encourage- 
ment  from  or  improvement  in 
the  operations  of  our  governing 
body,  the  FGC,  how  are  '^we" 
supposed  to  expand,  become 
"encouraged"  and  'Improved"? 
We  are  a  public  service,  dammit! 
When  a  natural  disaster  strikes, 
hams  are  usually  the  first  ones 
on  the  scene  ready  to  help.  And 
when  we  do,  we  are  praised  and 
glorified  , .  .sometimes.  But 

Continued  on  page  193 


24     73  Magazine  »  December.  1900 


"BRAND  NEW 


CHAMPJON  MESSAGE 
MEilORV  KEYER 


II 


DELUXE  MESSAGE  MEMORY  KEYER 


^89.95 


Faflttiras: 

vA   ri»i»<AB)*i:iW4 

■c  ciB»r 

"LTM  tor  EUiiy  050a>  ponwtlJ 


iledMTI'l*-i 


■fli|fi«#n 


•i  tm  «ifi%*rti  (Tipi^'  CMOS 


FiNnui^A! 


4  73^4, jj  jr  liny  ip«r0—fiit}flt  ttt* 
fiimp^    Hnfli  CO  CO  CO  D*  0» 

WB?  x'ju  osi  N V  N  ^  sn  a>i  Nw ii 


fSfHW'^     Vfi^Miv      P»A*     'vlC«    «'*tf 


Mod^l  «  TE2D1 


$69.95 

MESSAOE 
MEMORY 
KEYER 


MODEU  T£144  -  Deluxe  CMOS  EleclTonlc  KO'Tei' 

SS9.9S 

MODEL  TE133-'Same  **  TBf44  mtth  w§l  and 
tone  contrui  ifitefnal.  iess  s«fflr  atilD  k^ytng 

$49  95 

MODEL  TC122  -  same  as  TEt33  fess  wQt .  tune, 
sd  Id  state  keyi  ng  S36  50 


4r  YOUR  DEALER  OR  SBHD  CHECK  OR 
MONEY  ORDER  f    ^f;"^.,    ) 

ELECTRONICS,  INC 

K  A  r^     110S  RAMO  BLQQ. 

H  M  l#    SUF FALO  NY  142D3 


$349.95 


ANTENNA  TUNER 

New  Low  Profile  Design 
Here  is  a  new  tuner  that 
puts  more  power  into  your 
antenna,  works  from  1 60 
through  1 0  meters, 
handles  lull  legal  power 
and  then  some,  and  works 
with  coax,  single  wire  and 
balanced  lines.  And  rt  lets 
you  tune  up  without  going 
on  the  air! 


R-X  NOISE  BRIDGE  $55.00 

•  Learn    the    truth    about    your 
antenna. 

•  Find  Its  resonant  frequency. 

•  Adjust  l\   to  your  operating   fre- 
quency quickJy  and  easily. 

If  tfiere  is  one  place  in  your  station 
where  you  cannot  risk  uncertain 
results,  it  is  in  your  antenna. 


IC  KEYER  $117-50 

All  the  desirable  features  are  built  into 
this  compact  self-contained  unit. 
Sends  manual,  semi-automatic,  dot 
memory,  squeeze,  and  iambic. 
Speeds  5-50  wpm.  Buift-in  side  tone, 
speaker,  speed  and  volume  controls. 


ANTENNA  BALUNS 

Modal  1K    S32.S0 

1  Kw  CW,  3  Kw  PEP  input- 
Model  2K    $42,50 

2  Kw  CW,  6  Kw  PEP  input. 
Beam  Balum     $47.50 

2  Kw  CW,  6  Kw  PEP  input. 
Adjustable  U  bolt  for  mounting 
on  rotary  beams. 


VLF  CONVERTER    $59.95 

•  New  device  open  up  the  world  of 
Very  Low  Frequency  radio. 

•  Gives  reception  of  the  1750 
meter  band  at  160-190  KHz 
where  transmitters  of  one  watt 
power  can  be  operated  without 
FCC  license. 

•  Also  covers  the  navigation 
radiobeacon  band,  standard  fre- 
quency broadcasts,  ship-to-shore 
communications,  and  the  Euro- 
pean low  frequency  broadcast 
band. 


1750  METER  XMTR  $145,00 

•  Main  transmitter  assembly  factory 
wired  and  tested. 

•  Antenna  tuning  assembiy  can  be 
wired  and  mounted  on  your  bread- 
board in  less  than  an  hour. 

•  Meets  all  FCC.  requirements. 

•  For  use  in  U.S.A.  only.  Not  for 
Canada. 


LOOP 

Low  noise  reception. 

Nulls  out  interference. 

Accurate  direction  finder. 

Rotates  360''   in  azimuth.   Tilts 

+  90''  in  elevation. 

Superb  nulls. 

Loop  amplifier  connects  to  your 

receiver  or  to  your  VLF  converter. 


ANTENNA 

•    Rijg*in  loops  available  for: 

1600-5000   KHz    (160-80   meter 

^nateur    bands)    550-1600    KHz 

(Broadcast  Band) 

150-550  KHz  (VLF,   1750  meter 

band) 

40-150  KHz  fWWVB,  Loran) 

10-40  KHz  (Omega) 

5-15  MHz  (Model  HF'1) 

Loop  Amplifier    $67.50;  Plug-in  Loop 
Antenna    $47.50  each. 


Tfiese  Items  are  stocked  for  Christmas  delivery.  Order  today  direct 
or  tronn  your  favorite  dealer 

Include  S3  sf  andiing     :        -  iC  ^  510  for  Antenna 

T.jr^©r>   ftcid  sales  u-  m  Call^  Free  catalog  on  request 


i^  n^aefer  S^fvitifste  page  ^6 


73  Magazine  •  December,  1980     25 


John  Edwards  WB2tBE 
78  56  86th  Stree! 
GfendaleNYt1385 

ELEMENT  1— CROSSWORD  PUZZLE 


Across 

1 

A  microcomputer  memory 

1 

(abbr.) 

2 

4 

RTTY  machme 

3 

9 

Radio  users  (abbr.) 

4 

10 

Greenland  prefix 

11 

Cable  prefix 

5 

14 

Something  to  chew 

6 

15 

Scientific  test 

7 

19 

A  prosign 

20 

Teletype  (abbr.) 

6 

22 

Automatic  Picture  Re- 

12 

transmission  (abbr.) 

13 

23 

What  a  signal  usually  car- 

14 

ries  <abbr) 

15 

24 

Keyboard  Send-Receive 

(abbr.) 

16 

26 

Soviet  space  satellite 
(abbr.) 

17 

27 

A  Model  15  is  extreme  in 

18 

this 

21 

29 

HW                 ? 

25 

30 

A  display  medium 

26 

33 

Sudanese  prefix 

27 

35 

Moonbounce  (abbr.) 

28 

36 

Tough  WAS  state  (abbr.) 

31 

37 

Formal  shack  tit  e  (abbr.) 

32 

3a 

Old  repeater  prefix 

41 

Pakistani  prefix 

34 

42 

^1dlot  Box'*  or  fast  scan 

(abbr.) 

39 

43 

Pictures  via  radio 

40 

41 


Down 

RTTY  Read-Only  (abbr,) 

Vertex 

Meteor  scatter  (abbr.) 

Transmitter-distributor 

(abbr.) 

Opposite  of  Hi 

Proficient  hams 

Public  Relations  Assistant 

(abbr.) 

Code  of  Ethics  laid  one 

Morse  ^*from" 

Code  Chuckle 

Radioteletype(abbr.) 

Specialized  modes  require 

tots  of  this 

RTTY  tape  unit 

Radio  Corporation  of 

America  (abbr.) 

Crystal  use 

Soft  hams  (abbr,) 

'^Ears"  (abbr.) 

RTTY  test  string 

Amateur  television  (abbr.) 

Past  of  ''get^* 

Ham  salutation  (abbr.) 

What  most  specialized 

modes  are 

Recording  or  paper  (mylar, 

too) 

Transmitter  power  (abbr,) 

FCC  country  (abbr.) 

Familiar  battery  (abbr.) 


1 

2 

3 

4 

5 

fi 

7 

:B 

9 

13 

^  10 

11 

12 

^ 

14 

15 

IS 

TT 

ia 

1 

21 

1 

^^m  19 

20 

i 

22 

77 

■ 

23 

1 

1 

24 

25 

26 

2S 

12 

■ 

3(3 

31 

32 

33 

34 

35 

3B 

1 

37 

■        ' 

1 

38 

39 

1 

40 

41 

42 

43 

SPECIALIZED  MODES 

Have  you  ever  been  accused  of  being  an  "appliance  operator"? 
Are  you  a  complete  blockhead  when  it  comes  to  doing  anything 
more  technical  than  shouting  into  a  microphone  or  tapping  a  key? 
When  the  other  guys  talk  about  slow-scan  television,  do  you  think 
they're  referring  to  the  instant  replays  on  last  Sunday's  footbaEI 
broadcast?  If  so,  this  month's  puzztes  are  for  you. 

While  RTTY,  SSTV,  ATV,  EME,  ASCII,  and  MSTV  may  just  sound 
like  a  bowl  of  alphabet  soup  to  many  of  us,  there's  a  whole  class  of 
fellow  amateurs  out  there  who  consider  these  modes  to  be  the  real 
amateur  radio— a  place  for  experimenting,  not  just  communicating. 
So,  for  those  of  you  not  yet  hooked  on  an  exotic  operating  mode,  and 
even  for  those  who  are,  grab  a  pencil  and  see  how  much  you  know 
about  ham  radio's  other  side. 


ELEMENT  2- 

Match  the  specialized  mode  in 
equipment  in  Column  B. 

Column  A 

1)  Slow-scan  television 

2)  Meteor  scatter 

3)  Digital  communication 

4)  Fast-scan  television 

5)  Facsimile 

6)  Satellite  communication 

7)  Moonbounce 

8)  Microwave  communica- 
tion 

9)  Radloteletype 

10)     Medium-scan  television 


MATCHING 

Col 

umn  A  with  the  appropriate 

Column  B 

A) 

Horn  antenna 

B) 

Murphy  receiver 

C) 

Stylus 

D) 

Keyer  (CW) 

E) 

Model  33 

F) 

Wideband  10-meter  receiv- 

er 

G) 

Steerable  dish  antenna 

H) 

2-meter  transmitter/IO- 

meter receiver 

I) 

Stock  Robot  400 

J) 

Model  15 

K) 

Commercial  TV  set  and 

converter 

ELEMENT  3— TRUE-FALSE 

1)  Eleven  meters  was  the  first  amateur  band 
opened  to  slow-scan  television, 

2)  One  of  the  inventors  of  the  teleprinter 
was  Joy  Morton,  owner  of  the  Morton 
Salt  Company. 

3)  AF2M  is  the  official  FCC  designation  for 
frequency  shift  telegraphy. 

4)  The  Gem  in  ids  are  a  December  meteor 
shower. 

5)  The  ARRL  sponsors  both  RTTY  and  SSTV 
DXCC  awards. 

6)  Amateur  l0-GHz  signals  have  spanned 
the  English  Channel. 

7)  Most  moonbounce  activity  takes  place 
on  144  and  432  MHz. 

8)  The  facsimile  DX  record  is  from  New 
York,  N.Y,,  to  Seattle,  Wash. 

9)  Medium-scan  television's  frame  rate  is  2 
per  second. 

10)  To  operate  a  mode  not  permitted  under 
amateur  rules,  one  can  request  an  '*STA" 
from  the  FCC. 

11)  Most  RTTY  enthusiasts  gain  their  WAS 
awards  from  "cards''  printed  on  their 
Teletype. 

12)  Maximum  radloteletype  shift  is  900  kHz. 

13)  ^"NBVM  '  stands  for  Negative  Bias  Volt- 
meter. 

14)  ASCII  is  permissible  on  160  meters. 

15)  FSK  is  allowed  on  all  CW  bands,  even 
Novice, 

16)  Many  amateurs  call  moonbounce  "EME" 
in  honor  of  the  late  K6EME 


True       False 


Continued  on  page  180 


26     73  Magazine  •  December,  1980 


PRICES  F.O.B. 
HOUSTON 

PRICES  SUBIECT  TO 
CHANGE  WITHOUT 

NOTICE. 

tTEMS  SUBJECT  TO 
PRIOR  SALE 


f  ORDER  YOUR 

I  KWM  380  NOWl 

^OLD  PRICE  &  FREE  GOODS 


^KEINAA/OOD  RMCKAGE 


prutctar  chain* 


»^45 


Yuvi  simp l\r  can't  bin  btTMirr  rnEiflbilily.  petinr- 
mariu'  -inti  reputiilum  thtiti  thtr  52C  series  from 
KtJtiwcKxi,  and  ihc?  TSBStI  SE  is  no  exception. 
This  is  a  jusl  plain  good  radio  eiI  a  Iremendaus 
savings,  whon  yau  coiiitldi'i  I  He  free  CW  filtRr 
j y K-flfl)  and  micniuhunn  [ Mi;- 501  Uyo.        

TH52nsK  ezaas 

YK-88  ( :\V  rUTER     

TOTAL  629.95 


SANTEC 
HT  1 200 

SUGGESTED  LIST 
$379,95 

CALL  FOR 
QUOTE 


synthesized  hf 
transceivins  system 


continuous  coverage 


□-3D 


continuous  coverage  reception  no  gaps 
MHi       no  range  crystals  required 

^f-n  Amateur  Bar^d  transmission,  includlrig 

|gyJ|yA4efers  capability  for  MAflS.  Embassy. 

Government,  and  future  band  expansions 

PASSBAND  TUNNING 
R.  I.  T. 

INDEPENDENT  RECEIVE 
SELECTIVITY  WILL 
HANDLE  WARC  BAND 
EXPANSIONS 


ET  CETERA 


•I-   -I     ■■    !•    I      ■ 


#tlllt^k*i*«l     ■     B     ^ 


Cubic-Sw^fi  102SXA 
Astro  150   ......... 

Asiro  lOOMXA  . 

Mirage  B23  l  watt-3ti  Wart  amp  . 

DSI  SeOOA  w/AntMc  ......,,,., 

Cushcrdfl  A  3  Tribander    ........ 

Bird  43,  Slugs 

CDE  HaTiri-4  Rotor    ..-*.*.*-.*-i* 

Hjim*JI , 

fOK  Parm  7  Handie  with  BP/AC 
Ceirofi,G€572B   . 

VIE      O    {'■wo  ,..-.r.-,^^.>  .... 

Fib  Kenwood  Ymsu 
Kttrwocd  Servike  Manuils 

T*Jfei  TB5IM    

Teirex  TB6EM    . . 

Tdlfwc  Mooobander^  .  -  ^ . .  ^ 

Add  Nibbling  Tool 

fflnd  QSA5 , . ,  -.  1 1 ,  r  tt , , , 

Sprague  lCiaMFD/450V  Cap 

Rohn  Tower    ....  k  ►,..*., ,  20Wt 

25G,  45G  Sections 
Alliance  HD73  Rolor 
Amphenol  Silverplate  PL  259 
I  COM  2S5A  2M  Synihe^iicd 
ICOM  260A  2M  5SB/f  M/CW 
Kenwood  TSlBOS/OFC^Sfl 
ICOM  CZAT/TTPi^lCAO  ., 

New -I  com  (C720  w/AC/mikc 
Bearcif  23)  -  S2M.Q0 


779.00 

499.00 

89.95 

185.00 

169,00 

.    Stock 

169.00 

239.00 

149-iXJ 

34.00 

9l95 


10.00  ea. 

. .     425.00 

.     540100 

41.95 

100 

off  dealer 


CALL  FOR  QUOTE 


> 


leO  THROUGH  to  INCLUPIMCi  WAHC 
9  BANDS  FUUu^  OP^IW^iNiG 


ASTRO  103 

Hf  SS0  Tr«risc«v«f 


lOO  WATTS    ML  BANDS 
ALL  MODES 

ACC  DYNAMIC  RANGE 
GREATER  THAN  100  dB 

SELECTIVITY 
16      POLE      CRYSTAL 
FILTER  17  kHz  at  -  6dB; 
3.78  kHz  at  -  100  dB 

$1395.00   SUGGESTED  LIST 

CALL  FOR  QUOTE 


MEMORY 
KEYER 

BREAK- 
THROUGH! 


■I  1^  ^  ■  p 


© 


RG8/U 
Ob4  Shi4lfl 


fa»m  JIVF 


9BBB 


1214 

32tf/n. 


8237 

2ie/tL 


MX) 

100 
w 


Mo#»-ccKn»mJnatJftg 

B2S7 


H4 


100 

tea 


11 


rt 


«  7 


l»pn 

13  g 

13  i 
sg 

10  B 
i2« 


St 
9.* 
IS  4 


Cft 
&4 


^y 


H    8448 
^K-'   240/ft 


6-22  [7  ■  SO). 

2  ia  {i«>m  (1  111 


940  S 


Nh  36  feint^ic  feabiffis  if)cht6w^  ^kvo  At  A 
dMi^rMMJi  microcampyTfifs  up  to  ?  000  cnomcTief 
rnBtno'v.  automHtic  serial  numbflr,  bMcon  mode 
And  auiqmatic  morse  traineT  modu 


199.00 


AEA 


Brings  you 
Breakthfoughl 


the        I 


713-658-0268 


CALL  FOR  QUOTES 


1508  McKINNEY 
HOUSTON,  TEXAS  77010 


D 


*^  Bender  Senfice—&ee  psgs  226 


73  Magazine  •  December,  1980     27 


OSCAR  Orbits 


County  of  A 


Any  sateUite  placed  Into  a  near  Earth  orbit  suffers  from  the 
cumulalive  effects  of  atmospheric  drag.  The  much  pubHcized  de- 
scent of  the  SKylab  space  station  was  a  graphic  demonstralion  of 
tliese  effects. 

The  OSCAR  sateiiites  are  subject  to  atmospheric  drag,  of  course, 
and  the  present  period  of  intense  solar  activity  has  accentuated  the 
problem.  During  this  period,  our  sun  has  been  expelling  huge 
numbers  of  charged  particles^  some  of  which  f md  their  way  into  the 
Earth's  upper  atmosphere,  increasing  Ihe  density  (and  thus  the 
drag)  there.  It  is  through  this  region  thai  the  OSGARs  must  pass. 
OSCAR  8,  m  a  lower  orbit  than  OSCAR  7,  is  the  more  seriously  af- 
fected of  the  two. 

If  the  drag  factor  is  not  considered  when  OSCAR  cafcuiations  are 
performed,  long-range  orbital  projections  will  be  in  error.  For  exam- 
ple, by  the  end  of  1379,  OSCAR  8  was  more  than  20  minutes  ahead 
of  some  published  schedules.  The  nature  of  orbital  mechanics  is 
such  that  extra  drag  on  a  satellite  causes  it  to  move  into  a  lower  or- 
bit, resulting  in  a  shorter  orbital  period.  Thus,  the  satellite  arrives 
above  a  given  Earthbound  location  earlier  than  predicted. 

Using  data  supplied  to  us  by  Dr.  Thomas  A,  Clark  W3IWI  of  AM- 
SAT,  the  equatorial  crossing  tables  shown  hero  were  generated 
with  the  aid  of  a  TRS-80TM  microcomputer.  The  tables  lake  into  ac- 
count the  effects  of  atmospheric  drag  and  should  be  in  error  by  a 
few  seconds  at  most. 

The  listed  data  tens  you  the  time  and  place  that  OSCAR  7  and 
OSCAR  8  cross  the  equator  in  an  ascending  orbit  for  the  first  time 
each  day.  To  calcutate  successive  OSCAR  7  orbits,  make  a  list  of 
the  first  orbit  number  and  the  next  twelve  orbits  for  that  day,  List  the 
time  of  the  first  orbit.  Each  successive  orbit  is  115  minutes  later 
(two  hours  less  five  minutes).  The  chart  gives  the  longitude  of  the 
day's  first  ascending  (northbound)  equatorial  crossing.  Add  29°  for 
each  succeeding  orbit.  Wher^  OSCAR  is  ascending  on  the  other  side 
of  the  world  from  you,  it  will  descend  over  you.  To  find  the 


equatorial  descending  longitude,  subtract  166*^  from  the  ascending 
longitude.  To  find  the  time  OSCAR  7  passes  the  North  Pole,  add  29 
minutes  to  the  time  it  passes  the  equator.  You  shouid  be  able  to 
hear  OSCAR  7  when  it  is  within  45  degrees  of  you.  The  easiest  way 
to  determine  if  OSCAR  is  above  the  horizon  (and  thus  within  range) 
at  your  location  is  to  take  a  globe  and  draw  a  circle  with  a  radius  of 
2450  miles  (4000  kilometers)  from  your  QTH.  If  OSCAR  passes 
above  that  circle,  you  should  be  able  to  hear  it.  If  it  passes  right 
overhead,  you  should  hear  i1  for  about  24  minutes  total,  OSCAR  7 
will  pass  an  imaginary  line  drawn  from  San  Francisco  to  Norfolk 
about  1 2  minutes  after  passing  the  equator.  Add  about  a  minute  for 
each  200  miles  that  you  live  north  of  this  line.  If  OSCAR  passes  15^ 
east  or  west  of  you,  add  another  minute;  at  30^,  three  minutes;  at 
45^;  ten  minutes.  Mode  A:  145,85 ,95  MHz  uplink,  29.4-29.5  MHz 
downlink,  beacon  at  29.502  MHz.  Mode  B:  432.125-.175  MHz  uplink, 
T45.975--925  MHz  downlink,  beacon  al  145,972  MHz, 

At  press  time,  OSCAR  7  was  scheduled  to  be  in  Mode  A  on  odd 
numtiered  days  of  the  year  and  in  Mode  B  on  even  numbered  days. 
Monday  is  QRP  day  on  OSCAR  7,  while  Wednesdays  are  set  aside 
for  experiments  and  are  not  available  for  use, 

OSCAR  8  calculations  are  similar  to  those  for  OSCAR  7,  with 
some  important  exceptions.  Instead  of  making  13  orbits  each  day. 
OSCAR  8  makes  14  orbits  during  each  24-hour  period.  The  orbital 
period  of  OSCAR  8  is  therefore  somewhat  shorter:  103  minutes. 

To  calculate  successive  OSCAR  8  orbits,  make  a  list  of  the  first 
orbit  number  (from  the  OSCAR  8  chart)  and  the  next  thirteen  orbits 
for  that  day.  List  the  time  of  the  first  orbit  Each  successive  orbit  Is 
then  103  minutes  later.  The  chart  gives  the  longitude  of  the  day's 
first  ascending  equatorial  crossing.  Add  26="  for  each  succeeding 
orbit.  To  find  the  time  OSCAR  6  passes  the  North  Pole,  add  26 
minutes  to  the  time  it  crosses  the  equator  OSCAR  8  will  cross  the 
imaginary  San  Franctsco-to-Norfolk  line  about  11  minutes  after 
crossing  the  equator.  Mode  A:  145.85-.95  MHz  uplink,  29,4-29.50 
MHz  downlink,  beacon  at  29.40  MHz.  Mode  J:  145.90-146.00  MHz 
uplink,  435,20  435.10  MHz  downlink,  beacon  on  435.090  MHz. 

OSCAR  8  is  in  Mode  A  on  Mondays  and  Thursdays,  Mode  J  on 
Saturdays  and  Sundays,  and  both  modes  simultaneously  on  Tues- 
days and  Fridays,  As  with  OSCAR  7,  Wednesdays  are  resen/ed  for 
experiments. 


QKJUL  1  OBBITAL    HVtStfUTIOI  FfUl  D1£CIC|ULI 


oacu  •  oaitTAL  mrottx&rtCN  wtm  o^ccbbeb 


7  QRPiTKL  uromATiOH  POC  3tm^m?t 


Qsofi  ■  QfefitfM.  tKrauiftflM  pa  jutuat 


pair  1 

DATt 

TTK 

m-^  cnnuc        orbit  i         MktE       tub         eq.  ciossiic         qmit  •         date       rtis         isd.  cnsstw} 

mmix 

9             HATS          TllB             90.    C 

laoBSinc 

■ 

icarri       toticsaxs  MBrt                                             «3fr>       ci^KflS^  hbti                                              {tatrt       tiM 

ECBEES  nest! 

(tairi       (&BcaEEi  wtm 

I' 

^1*51 

1 

•ftt:«f                  71. • 

13ti9                  1             «Ui72                  »i,E                          ttt%\                  \             ilJllA 

*B.T 

14492                   I              •9^7^43                   7| .S 

3ti#f 

2 

»l]l:H                  tl.4 

11»IJ                 2            *fie:ll                 U.t                        Uflt                 Z             iil*:31 

•3.S 

I44lf                  2             1112: If                 73.7 

rtvit 

3 

illl:22                  f|,] 

I349T                 1            «f2^,^M                 «].)                         ZtffI                 3             •124^31 

f?*I 

1443*                 3             flfTfl2                 73.9 

27*51 

1 

«tH:l«                  fl,9 

14PI1                 4             ii27T^*                 (1.1                        Ilfff                 4             niSiS* 

12,1 

14444                 4            9111 t 57                 7 S.J 

lumi 

% 

fff^-54                   71. 7 

14«2»                 S             1132 13^                 i«.5                        Iiti2                 S            •lilt  If 

95. e 

14451                 S             9Uti41                 79.4 

17716 

i 

9Jii:l9                  H.l 

1:4119                 «             it3.7r21                 ».?                        21114                 <             f«17t3l 

ei,4 

14472                 i             9;2l:2fi                 77,* 

17T39 

7 

»L44:21                li].t 

14157                 1             eff42t*4                 li.9                        28111                 7             9111  e4J 

94.9 

1449&                 7             9I2iil9                 79.1 

Z7745 

1 

*#^3:41                 iA*7 

14167                    1              IIE4«t5^                   «««1                           2ala>                   §              till  ill 

71.  f 

14^91                 I             IU9i^5                 i 

Sl.t 

27754 

» 

•  14T:!>6                11(2.7 

34ial                  f            firSltlB                 O.I                        21142                 »            tll^:U 

93,4 

14514                  %             I115t39                 \ 

11.7 

27746 

I« 

M4TtU                 ^1.2 

14695                   11           I905&!23                  71.6                         "1%\\A                   IB           »«M  j  31 

77.  J 

1452S                  19          1149123 

12.4 

21-J79 

n 

i^lMilB              l«l.e 

14119                  \\           I9I«1:19                 71, B                        28117                  11           8GI?l6l46 

90.9 

14541                  11           itIltSfi 

n.i 

2-7r41 

u 

N40:4fi                   ys.b 

14123                  12           I!I10^:?4                 73.0                         2Slfte                 12           RlSasel 

1D4.5 

\k%%\                 12          fie(IQt49 

i9A 

S7HB4 

n 

!ti35:fl«                  98.2 

11137                 13          0U»:39                 74. £                       2ai»2                 13          V8S23III 

B9.7 

i45e»            13       fltiiias            1 

It.  3 

57B46 

u 

m-lA:i^                  14,  t 

14iSl                 14          QU^i2%                T&.4                      2b2IS                14          ltUi33 

1B2.9 

\A\%%                 14          Ifl^iQ^                 i 

ftl.S 

27  013 

i*^ 

BlSftTJJ                 97.* 

UlfiS                  li           012B:1I                  7*^.7                         19217                  15           M<4l51 

B7,7 

14547                   15           IdlSiSI                  \ 

tJ,7 

37a4J 

i« 

••a7fSL                 i2.S 

1417  9                 1«           »124:55                 77.9                        ai37i                  I€           lUlifl^j 

111.3 

14611                    U           9925:17                   i 

iJ.9 

27  854 

17 

eiaj^is            H.1 

1419 J                 17           tl2»i4l                 79.1                        21243                 17          11^9 j 23 

89.2 

14(25                 17           9929:21                 \ 

15,3 

27etf 

U 

iii]  III            »«9 

14217                  II           1114 :2i                 il^l                        2825S                  18          ilDtl? 

99.9 

14919                 19          1915  {15                 { 

li.3 

iTrr* 

14 

iltS:37                 f4.^ 

14221                  19           lllfill                 11.5                        11167                  19          tl32f55 

04.9 

14«5)                 if          111^149 

17,1                        1 

^Ml 

3f 

••t4i^!>^                 Ti.l 

14231                 79          191«i4<                 W.9                        3l2li                 21          1127  >I9 

»S.2 

144*7                  19           i944i3J                  ^ 

19,9                      1 

I7W1 

n 

•119 T 19                f2-f 

I424«                 21           1915$  29                 M.2                        21292                 21           »I2«t27 

»3«9 

14991                   21           •949:17 

lt*t 

179lt 

ti 

mat  3ft            rp<i 

14212                   22           1919:14                  it. 4                         UMl                  22           lllll41 

39.1 

14991                  2}           #954 1 91 

11,2 

.  ^iS 

n 

•112:42                  91.4 

142Tf                   23           lilt;!!                  U.*                         2131?                  23           1119^59 

S1.5 

147^                 23          »^«?45 

72.4 

S^Ml 

24 

litzifi             7f,i 

14291                  24           Ifl9{«4                 11.9                        29331                  14          1114:1} 

*S.l 

14723                34          9193  £319 

13.9 

?7i^ 

25. 

MM;  14                  If.l 

14314                  2^           il24;a                 13.1                        2i342                  25          9911^  It 

79. S 

i47r?            2S       itttai 

74.1 

17*«7 

1% 

flSf:J9                IJJ.l 

143)9                  »           9129:34                  14,2                         i9»'5                   ^           •1fTi45 

93.  i 

\A-                       K          9112±57 

H,9 

ITM» 

n 

li4?=47                  II.  J 

14332                  27           1933:59                  t&.4                         ilJfit                   27           iH7ll1 

79.il 

l4TiKi                   H            9117:49 

77,2 

17  »1 

21 

tU4,"fI              iii.« 

14144                 29           911ft  :4i                 14.7                        29199                  2S          il9itl7 

91*9 

14779                 M           9122:24 

79,4 

l«ffft4 

I* 

#14^319                  H,7 

I43«f                 2t          fH3;2»                 «7.9                        21192                  29          9191 1)% 

76.9 

1479)                  It           il 27,99 

74.7 

liPlT 

!• 

1137:33                11*. 3 

M374                  19           994fla3                  99,1                         ]|4|S                  39           ltS4i4t 

99.4 

14117                  19          IJ^atSl 

ii.f 

38129 

31 

•  •3«iU                   n.l 

14341                  11           9952159                   71^3                         2i4U                  31           1149*14 

194.9 

14131                 31           I13ias 

13.1 

^                               DISCOUNT 

1                    1  XvJS-oO         DEALER  A301 

FREE 

COMPUTER 
CATALOG 
UPON 

■request 

1 

^^S^^^^^f^ 

^^^■' 

II 

■                                COAIPUrER  $PEaAt/S7S 

V^                    26-lOSl  4K  i«w«l  1     «    ,« 

S424O0 

F                     3^1141  RS  733  Br»nt^ 

64  00 

^^BBGBB^IBH^P3i^  fltjCi 

i 

4 

•h^^^m '  -  ^V  jV 

^                        3fr.ni0    O    K  ln1»r+oc« 

74'JOO 

i^^^^^^^^^P^^'  ^B 

\ 

^ 

»IT«OMlaiD^ 

^4l7Mvlephcne  Mod«m       . 

419  00 

16^00 

^59  00 

■ 

^^^ 

Rjtt  TOO  CPS  C&nlronFC*  730  I'rini*! 

U%  DISCOUNT 

TeKi  Ouoliiy  Centro^mc*  737  f  rtpitar 

CAT  Modarp ^  ..,_,,.,...    , 

S19QQ 

149,00 

21%  DISCOUNT 

Off  List 

1-800-841-0860  Toll  Free  Order  Entry 

Off  List 

64K  1 

PllVf  $M66.0< 

)                                           MICIIO  MAHAGEMfNT  SYSTEMS,  INC.      ^ 

3t3 

16K  L  II  $«70.0C 

^ 

lo  Tciv#i  on  Otii  cit  Si«i«  S>iipnH 

mti                                                             BOWNTOWN  PtA7A  SHOP1*lNG  CENTER 

use  SECOWO  AVI    S  W. 
k                                                                                  CAItO    GEORGIA  3I72§ 

L^f 

R5.  W  Dov  tfmiT#d  Warrcmiy 

94!«i  lfiv«n1icM>  In  S.E.  U.S. A 

GA   IH40N£  MO    {^12)  37?  7120 

2A    73  Magazine  •  December,  1S80 


11  COS 


ATF  417  pr»-amp  nat       Special  S19.95 

MRF  901  UHF  transfStors,  1  QHz       Special  S  3.95 

COMPIETI  KfTll  CONSlSTrNG  OP  FVERV  fSSENTiAL  PART  NEEDED  TO 
MAKE  VOUR  COUNTER  COMPLETE  MAL^iOOA  ?  OJGIT  COUNTER  WiTH  FRE- 
QUENCY ftANGE  OF  ZERO  TO  300  MHi  FEATURES  TWO  INPUTS  ONE  FOR 
LOW  FREQUENCY  AND  ONE  FOR  HIGM  FREQUENCY:  AUTOMATIC  ZERO 
SUPPRESSION  TIME  BASE  (S  lO  SEC  OR  1  SEC  GATE  WfTH  OPTEOHAL  10 
SEC  GATE  AVAILABLE  ACCURACY  i  OCT/-.  UTILIZES  iOMHz  CRYSTAL  & 
PPM 
COMPLETE    KIT„.„,.. „,.„, S1» 

HAL^IOOA  7  DIGIT  COUNTER  WITH  FREQUENCY  RANGE  OF  ZERO  TO  300 
MH/  FEATURES  TVyO  INPUTS  ONE  FOR  LOW  FREQUENCY  AND  ONE  FOW 
HIGH  FREQUENfCYAUTOMATlCZERO  SUPPRESSION  TIME  BASE  IS  1  0  SEC 
OR  1  SEC  GATE  WITH  OPTIONAL  10  SEC  GATE  AVAILABLE  ACCURACY 
±  .001%.  UTILIZES  10  MHz  CRYSTAL  5  PPM 

COMPLETE    KIT - .    - *1M 

HAL- 50 A  SDIGIT  COUNTER  WITH  FREQUENCY  RANGE  OF  ZERO  TO  50 
fAHz  OR  BETTER  AUTOMATIC  DECIMAL  POINT  ,  ZERO  SUPPRESSION  UPON 
DEMAND  FEATURES  TWO  INPUTS  ONE  FOR  LOW  FREQUENCY  INPUT,  AND 
ONE  ON  PANEL  FOR  USE  WITH  ANY  INTERNALLY  MOUNTED  HALTRONIX 
PRE  SCALER  FOR  WHICH  PROVISIONS  HAVE  ALREADY  BEEN  MADE  10 
SEC  AND  1  SEC  TIME  GATES  ACCURACY  i  001%  UTILIZES  TO  MH7 
CRYSTAL  5  PPM 
COMPLETE    KiT ....*^-4 *.- S109 

riE'SCALf  i  ICiTS 

HAiioopat  $14.95 

(Pfe-^rill«d  G10  boafd  anil  3^1  components^ 

(Same  as  above  i*ith  Dr«arnp) 

HAL  600  r«l . . . , - S29.95 

ilPre4nll«fl  GtO  !>oard  and  att  componenisl 

(Same  as  at>ov«  frut  «im  pf«3fTH»  "^^ 

TOUCH  TONE  DECODER  KIT 

HIGHLY  STABLE  DECODER  KIT  COMES  WITH  2  SIDED-  PLATED  THRU  AND 
SOLDER  FLOWED  G^IO  PC  BOARD.  7  567  S.  2  7402,  AND  ALL  ELECTRONIC 
COMPONENTS  BOARD  MEASURES  3%  iS-s^  INCHES  HAS  12  LINES  OUT 
ONLY  $19.95 

DELUXE  12  ftUTTON  TOUCHTONE  ENCODER  KfT  ulili^mg  the  new  ICM  7206 
Chip  Pfovides  boin  VISUAL  AND  AUDIO  -narcai ions'  Comes  wuh  iis  own  two 
tor*ean^odif#d  aiummym  cabsnei  Measures  only  2  3/4  x  33^4"    Co"^pleie  wHh 
TouchTone  pad.  board.  cFystal.  chip  and  all  necessary  components  to  fimsh 
the  kii 

For  those  who  wish  !o  mount  the  encoder  m  a  hand  held  ufiiL  tfie  PC  board 

measyr«s  only  9n6"  ?«  1  3^4'"  ThiS  parital  Hit  wiih  PC  board,  Cfystal.  chip  and 

components 

pn ICED  AT - $14.M 

ACCUKIYEl- MEMORY  OFTKIN  KIT  THIS  ACCUKEYER  MEMORY  KIT  PRO 
VIDES  A  SIMPLE.  LOW  COST  METHOD  Qf  ADDING  MEMORY  CAPABILITY 
TO  THE  W&4VVP  ACCUKEYER   WHILE  DESIGNED  FOR  DIRECT  ATTACH 
MENT  TO  THE  ABOVE  ACCUKEYER,  IT  CAN  ALSO  9E  ATTACHED  TO  ANY 
STANDARD  ACCUKEYER  BOARD  WITH  LITTLE  DIFFICULTY  $16.95 

ACCUKfYll  IKITJ  THIS  ACCUKEYER  IS  A  REVISED  VERSION  OF  THE  VERY 
POPULAR  WB4VVF  ACCUKEYER  ORIGINALLY  DESCRIBED  9Y  JAMES  GAR- 
RETT, IN  OST  MAGAZINE  AND  THE  1975  RADIO  AMATEURS  HANDBOOK. 

ACCUKIVll— MEMOKT  OfTtON  KIT— TOGETHER  ONLY  1 32. 00 

6-DIGIT  CLOCK   •    12/24  HOUR 

COMPLETE  KIT  CONSISTING  OF  3  PC  GlO  PHE-DRILLED  PC  BOAHDS.  1 
CLOCK  CHIR  6  FND  359  READOUTS,  13  TRAlHSlSTORS.  3  CAPS,  9 
RESISTORS.  5  DIODES.  3  PUSH  BUTTON  SWITCHES.  POWER 
TRANSFORMER  AND  INSTRUCTIONS 

DON?  SE  FOOLED  BY  PARTIAL  KITS  WHERE  YOU  HAVE  TO  BUY 
EVERYTHING  EXTRA 

rtlCEOAT     .- ,....,...,,.* HI.»1 

CiOCK  CAU  Available  arvo  will  fit  any  one  of  rh«  above  clocks.  Regular 
Prtce        S£  50  ftM  Only  t4.SO  mAtn  bttwitif  m*ttt  ciock 

Sm-Piorr  ALASM  ClOCl  kit  tor  home,  campef .  RV.  or  li«ld<<tay  u«  Operates 
on  1Z  von  AC  or  DC.  and  has  its  own  fiO-Hr  \*mt  basfl  on  lh#  board  Complele 
with  *K  a-lectronrc  components  anc^  twf>-pie<^e,  pre  drilled  PC  boards  Board 
sizff  4"  (  3"  Complete  wUti  speaker  and  5witc:h«  It  operated  on  DC.  ihe^e  t* 
nottiin^  mdie  to  buy. " 

PttOOAT... ...,. ...*.... ,- ^. .*-.,- tlft.« 

Tw^lve-wolt  AC  line  cortf  tor  those  who  «istt  lo  dcKtfate  the  clock  from  1 10- volt 
AC  »i*»* 

SHIPPING  INFORMATION 

ORDERS  OVER  S20  00  WILL  BE  SHIPPED  POSTPAID  EXCEPT  ON  ITEMS 
WHERE  ADDITIONAL  CHARGES  ARE  REQUESTED  ON  ORDERS  LESS  THAN 
$20  00  PLEASE  INCLUDE  ADDITIONAL  SlSO  FOR  HANDLfNG  AND  MAiLING 
CHARGES  SEND  BASE  FOR  FREE  FLYER 


HAB<XD  C.  mOWLANO 
WeZXH 


Hal-Tronix  ^3t 

p.  O   BOX  1101 

SOUTH  GATE,  MICH    48195 

PHONE  (3 13U85- 1782 


Shortwave  Listener? 


SEND   FOR    FREE  CATALOG! 


Scanner  Buff? 


hcrease  your 


Cistmmg  Pmeti 


^m(^'  ^•-.■'■■^. 


FEDOAl 
FREQUENCY 

DIRECTORY 


(Plus  S2,O0 


ove:r  100.000  unclassified  frequencies. 

agencies,  and  locations  of  us  federal 

GOVERNMENT   COMMUNICATIONS  STATIONS, 
2-420  MHz.    MILITARY.  JUSTICE,  TREASURY, 
AIRCRAFT  TOWERS.  NASA,  DOZENS  MORE* 


i:**  ^ 


SOUNDS  OF 
SHORTWAVE 


$5;95 


A  60-MINUTE  CASSETTE  IDENTIFIES 
THOSE  STRANGE  SOUNDS:  TELEMETRY.iyiULTI- 
PLEX  JAMMING.  SPY  TRANSMISSIONS.  SWEEPERS, 
TELETYPE,  MANY  MORE.  EXPLAINS  IN  EASY— 
TO— LISTEN  TERMSi  HOW  TO  BUY  A  RECEIVER, 
PLANNING  THE  PROPER  ANTENNA,  COPING  WITH 
INTERFERENCE.  WHEN  AND  HOW  TO  LISTEN, 
CHOOSING  ACCESSORIES. 


SCANNER  BEAM 


139-95 

|Flu«  S2.00 

FINALLY,  A  DlRECTtONAL  ANTENNA  MADE 
ESPECIALLY  FOR  SCANNERS,  PICK  UP  THOSE 
WEAK    DISTANT  STATIONS  WITH  EASE, 
OPTIMIZED  FOR  108  -  174  AND  406  -  512  MHZ 
AIRCRAFT,  LAND  MOBILE,  AND  AMATEUR  SERVICES, 
ALSO  RECEIVES  50  -  50  hi^VAi  (non-directiorral ^ 
MATCHING  TRANSFORMER  AND  MOUNTING 
HARDWARE  INCLUDED. 


SEARCHING    FOR    THE   SOUNDS  OF    TQMORBQIV 


ROVE  tNTERPRISES 


route;  1   BOX   156  K      BRASSTOWN,  HC  28902 


•  DEALER  tNOUIRY   INVITED  »       «^3&2 


v^  f^e^Oer  5«fvrc0— S0«  page  226 


73  Magazine  •  December,  1980     29 


dh 


Model  1528 

Drake  L7 

Continuous  Duty 
160-15*  Meters 

2kW  Linear 
Amplifier 

Tempfirafure  controffed  design  for 
^'key  down*' operation  over  a  wide  frequency  range. 

2  kW  PEP.  1  kW  cw,  RTTY,  SSTV  operation— ari  modes  full 
rated  mpuL  continuous  duty  cycle. 

160-15'  meter  amateur  band  coverage,  plus  expanded  ranges 
for  any  future  lif  band  expansions  or  additions  withm  FGC 

rules.  These  ranges  afso  include  increased  coverage  for 
MARS,  embassy,  government,  or  ottier  such  services. 

The  Drake  L7  utilizes  a  pair  of  Eimac  3-500  2  triodes  for 
rugged  use.  and  lower  replacement  cost  compared  to 
equivalent  ceramic  types. 

Accurate  built-in  rf  wattmeter,  with  forward/reverse  readings, 
is  switch  selected.  Calibrated  300/3000  watt  scales. 

Temperature  controlled  two  speed  fan  Js  a  high  volume  low 
noise  type  and  offers  optimum  cooling. 

Adjuslaole  exciter  age  feedback  circuitry  permits  drive  power 
to  be  automatically  controlled  at  proper  levels  to  prevent  peak 
clipping  and  cw  overdrive.  Front  panel  control, 

By-pass  switching  Is  included  for  straight  through,  low  power 
operation  without  having  to  turn  off  amplifier. 

Bandpass  tuned  input  circuitry  for  low  dtstortton  and  50  ohm 
input  impedance. 

Amplifier  is  comprised  of  two  units— rf  deck  for  desk  top  and 
separate  power  supply. 

Operates  from  120/240  V-ac.  50/60  Hz  primary  line  voltage. 

DRAKE  L7  SPECIFICATIONS 

•  Fmqyency  Covecage*:  Ham  bands  V60  Ihrougli  15  ffietefs*.  Non- 
amateur  frequencies  between  6.5  and  21.5  MHz  may  foe  covered  wllh 
some  n>odilication  of  the  input  circuit  •  PtAt«  Power  Input:  2000  waits 
PEP  on  ssb  and  a-fn.  TOOO  walls  dc  on  cw,  RTTV,  and  SSTV.  •   Drtvt 
Power  Requirements:  100  watts  PEP  on  ssb  and  75  walls  on  cw,  a*m. 
RTTY,  and  SSTV.  ■  Inpul  impeifance:  60  ohms.  (Sand pass  tuned  input} 

•  Output  Impedance:  Adjustable  pinetwortt  matcbes  50  ohm  tine  with 
5WR  nol  to  exceed  21.  •  Intennoduiafion  Pistoftion  Products:  In 
excess  of  -  33  dB.  •  Wattmeter  Accuracy:  300  watts  forward  and 
reflecied,  ±{5%  of  reading  +  3  watts),  3O00  watts  forward,  ±(5%  of  ^ 
reading  -»■  30  watts).  •  Power  Requirements'  240  volls  50-60  hert^  15 
amperes,  or  120  volts  50-60  hertz  30  amperes.  •  Tutje  Corrtplement:  Two 
of  3-5O0Z  or  &802/3-5OOZ  or  3-400Z.  •   Dimensions:  Amplifier  13.69"'W  x 
6.75 '^H  X  14.25"D  (34.6  x  17.1  x  36,2  Cm}.  Power  Supply  6,75 ''W  x  7.88 "H 

K  1 1  "0  (17  X  20  X  28  cm).  •  Weight:  Amplifier  27  lbs  (12,25  kg),  Power 
Supply  42.5  lbs  (19.3  kg), 

'Bxfiort  model  incfuifes  coverage  of  th&  ^O-meter  Ham  Band. 


Model 

1  Dv9 


Drake 
Matching  Networks 

MN7  and  MN2700 

Models  1538  and  1539 

•  Frequency  Coverdge:  18  -  30  MHz 

•  Antenna  Choice:  Matches  ani&nnas  fed  with  coax,  balanced 
line  (use  optional  B-1000  Balun).  or  random  wire. 

•  Antenna/ By-Pass  Switching:  Allows  matching  unit  by-pass 
regardless  of  antenna  in  use,  and  selects  various  antennas, 

•  Extra  Harmonic  Reduction:  Employs  **pi-network"  low  pass 
filter  type  circuitry  for  maximum  harmonic  rejection. 

•  Built-in  Meterino:  Accurate  Rf  Wattmeter  and  VSWR 
Reading,  pushbutton  controlled  from  front  panel. 

•  fnput  Imiiedance:  50  ohms  resistive. 

•  Power  Oapabiiity:  MN7— 250  watts  average  continuous  duty 
(0-300  W  scale).  MN2700— lOOO  watts  average  continuous 
duty  (2000  watts  PEP).  (0-200  or  0-2000  W  scale). 

•  Dimensions:  MN7— 13.1  "W  x  4.53"H  x  8.5 "D  excluding 
knobs  and  connectors  (33.26  x  11.5  x  21.6  cm).  MN2700— 
13.1  "W  x4.53''H  x  IG^D  excluding  knobs  and  connectors 
(33.26  X  11.5X  33  cm). 

•  Wfelght:  MN7— 10  lbs  (45  kg),  MN2700^11  lbs  (5  kg). 

Drake  MN7  and  MN2700  Specifications 

•  Frequency  Coverage:  1.8  to  30  MHz,  Band  Switch  marked  for  160  BO, 
40,  20.  15.  and  10  meter  amateur  bands:  however,  freQuency  coverage 
t>etween  amateur  bamJs  is  possible  by  using  the  nearest  band  positions 
Mith  a  small  reduction  In  matching  capabiMty^  *  Input  Impedinc*:  50 
ohms  (r^strve).  *  Ljoad  imp#ciaficfl:  50  ohm  coaxial  with  VSWR  of  5:1 
or  fess  a!  any  phase  angle  (3:1  on  10  meters).  75  ohm  coaxial  at  a  lower 
VSWR  can  be  used.  •  Balanced  F«edlines;  With  the  Drake  B-IDDD 
accessory  balun.  which  mounts  on  rear  panel,  tunes  feed  pomt 
impedances  of  40  to  1000  ohms,  or  5:1  VSWR  referenced  to  ZOO  ohms 
p:1  on  10  meters).  *   Loog-Wirt  Antennas:  Feed  point  impedances  up 
to  5r1  VSWR  referenced  !o  60  ohms.  Also,  5:1  referenced  lo  200  ohms 
with  the  Drake  fl-lOOO  accessory  balun  (3:1  on  10  meters).  •  Me  ten 
Reads  VSWR  or  forward  power  •  Wattmeter  Accyracy:  ±  5%  of 
reading  ±  1%  of  fulJ  scale.  •  Insertion  Loss;  0.5  dB  or  less  on  each 
band  after  tuning.  *   Front  Panel  Controls:  Provide  for  Ihe  adjuslrnent 
of  resistive  and  reactive  tuning*  antenna  switching,  band  switctiing, 
VSWR  calibration,  and  selectiorj  of  watts  or  VSWR  calibration,  and 
selection  of  watts  or  VSWR  functions  of  Ihe  meter    •  Rear  Panel 
Connectors:  The  rear  panel  has  four  type  SO-239  connectors  (one  for 
input  and  3  for  outputs),  three  screw  terminal  connections  {tor  long-wire 
and  open  wire  feeder  syslems),  and  a  ground  post- 


Sp^CfftCBiions,  avBtiabiiity  and  prices  subject  to  change  without  notice  or  obligation. 


R.  L.  DRAKE  COMPANY 


DRAKE 


540  Rrchard  St    Miamisburg,  Ohio  45342,  USA 
Phone  1513\  866-2421  •  Telex  288-01? 


30     73  Magazme  •  December,  1 980 


Model  7077  Dynamic 
Desk  Microphone 

•  Au6iO  6(%6  ]iv0]  characterisU(»  custom 
designed  to  matcti  (f^e  transmit  aiKlro 
requirements  of  the  Drake  TR7.  •   Features  boHi 
VOX  and  PTT  opera t ion  without  modification. 

•  High  Impedance  *  Includes  coil  cord  and 
plug  wired  for  direct  connection  to  the  Drake 
TR7.  •  Slyle  arvd  color  provide  a  beautiful 
match  lo  Ihe  Drake  7-iine  •  Size  4.3 "W  x  6,8 ''D 
X  93*H  (109  X  14.7  %  23.6  cml  Weight  t  lb  7  0Z 
1660  g). 

Model  t553 

i^   SP75  Speech  Processor 

Provides  an  increase  In  average  power/ 
readability  of  a  srngle  side£>afid  voice  signal 
during  weak  signal,  high  interference  conditions, 
TTie  SP75  *s  connected  tetween  the  microphone 
and  microphone  input  of  the  ssb  transmitter, 
requiring  no  modi  fi  cat  Ion  of  existing  transmitter 
or  transceiver.  A  front  panel  switch  allows  the 
processor  to  be  switched  in  or  bypassed.  Two 
additional  inputs,  such  as  a  tape  player  or 
phone  patch,  may  be  front  panei  selected. 

Rf  envelope  clipping  adjustable  tietween  zero 
and  twenty  dec i bets  LED  indicales  proper  audio 
mput  level. 

Mutmg  circuitry  reduces  gain  during  speech 
pauses,  altowmg  VOX  operation  with  the 
processor  on. 

SPECinCATFOMS  •  Processing  Typ«: 

PrecHpping  audio  compression  followed  by  rf 
envelope  capping  at  the  processor  intermediate 
frequency.  •   Rf  Clipping  Range:  Adiustable  0  to 
20  dB  from  front  panel  control-  •   Inpul  Leve>l 
^Micmphoo©  input):  3.5  mV  mmimum  tor  full 
processing.  Gain  adjustable  to  accommodate  up 
to  3O0  mV  maximum.  •  Input  Level  (Tape  and 
Patch  Inputs):  15  mV  minimum  for  fuli 
processing.  30  mV  maximum.  •   Inpul 
Impedance  (1M aerophone):  1  megohm.  *  Input 
Impedance  (Tape  and  Patch):  50  ki  I  ohm. 

•  Output  Level  wi  Processing:  0-50  mV 
adjustable  mto  50  kilohm  load    •  Output 
Impedance:  50  kilohm.  *   Muting  (Microphone 
Input  Only):  10  to  20  dB  attenuation  during 
speech  pauses^  *  Frequency  Response:  400- 
6000  HzfiiB  dB,  *   Distortion:  Less  than  5% 
T,H.D4i  1kHz,  20  dB  clipping.  •   Power  11-16 
V<Jc#95  mA.  •  Siie:  7'L  x  6%  'W  x  2'^*  'H 
(17.3  X  15.9  X  5.4  cm).  •  Wdight:  1,4  lbs.  (.83  Kg). 


Model  1520 

P75  Phone  Patch 


Hylwtd  Phone  Patch  for  use  with  7-1  ine  or  other 
receiver' transmitter  combination.  *  In /out 
Switching  •  Ad[ustab)e  TX  and  RX  level 
controls 


Model  ISaS 

IE    CS7  Coax  Switch 

•  Switcties  up  to  five  coaic-fed  antennas  via  one 
main  feed  line.  *  Allows  selection  of  up  to  five 
radios  at  other  end  of  main  feed  line, 

•  Minimizes  amount  of  coax  rveeded  for  multi- 
antenna  Installation   •  Grounds  unused  inputs 
(both  local  and  remote). 

DRAKE  CS7  SPECIFICATIONS  •   Maximum 
Inpul  Power  2000  waits  PEP  «   Frequency 
Range:  Up  to  30  MHz,  insertion  of  Switch 
changes  VSWR  no  more  than  1.05;T.  From  30 
MHz  to  150  MHz.  msertion  changes  VSWR  no 
more  than  1.5:1  (bofh  switches).  •   Operallng 
Temperature  Range:  -40'F.  to  ISO^F.  •  Supply 
Voltage:  120  Vac  or  240  V-ac  selectable,  50/60 
Hz,  50  watts.  •   Dimen$lon$  &  Weight:  Console 
— 5,25^H  X  6.81  "W,  7.06"  cabinet  depth  (13,3  x 
17.3  X  17,9  cm);  4.33  lbs  (196  kg);  Remote 
Antwma  Switch— 7.13 ^H  x  5,88*W  x  4.39 *D 
(ta.1  X  15.Q  X  11.1  cmK  8:19'  (20.8  cm)  center  to 
center  mouniing:  5  lbs  ^2.27  kg). 

Model  1531 

^    MS7  Matching  Speaker 

•  Size:  75-0  K  6.9*^  K  4,6 "H  excluding  feet  (19 
X  17.5  x  11.6  cm).  •  Wetghl:  ZSIbs(Vl3  kg). 


li 


Dry'*  Dummy  Loads 

— no  oil  reqiMiwd 


Model  1SS1 


Moctel 
1S50 


Model  1551  Drake  DL-1000 

•  1000  watts  for  30  seconds,  with  derating  curve 
to  5  minutes.  Accepts  Drake  FA 7  cooMng  fan  for 
extended  high  power  operation.  •  VSWR  o*  1-Sr1 
max.  0-30  MHz  •  SO-239  coex  connector 

•  Rubber  feet  for  desk  or  bench  use  •  Size  14" 
X  3.6"  {:^,6  X  9.1  cm).  Weight:  2  lbs  (910  g). 

Model  1S50  Drake  DL-300 

•  300  watts  for  30  seconds,  with  derating 
cune  to  5  minutes.  *   iuilt-in  PL-2&9  coax 
connector  for  direct  connection  to  rear  of 
transceiver  or  transmitter --no  jumper  coax 
necessary.  •  VSWR  of  1.1:1  max.  0-30  MhZ  t.5 
max  30-160  MHz  •  Ideaf  as  bench  test  device 
for  amateur  or  commercial  hf  and  vhf  gear, 

•  Small  size  fits  conveniently  in  any  fiefd 
service  tool  box  6.7*  x  2.06"  tl7*0  x  5.3  cm*. 
Weight:  1 1  02  {310  0. 


SpecfficatiOfts,  avaitabitify  and  prices  subiect  to  change  without  notice  or  obfigatton 


1^19 


R.L.  DRAKE  COMPANY 


DRAKE 


WH7 

Directional 
Rf  Wattmeter 

Model  1514 


•  Direct  tonal,  in  tine  wattmeter,  •  Removable 
coupler  provides  remote  metefing.  •  Three 
calibrated  scales  (0-20,  0-200,  and  0-2000  watts. 
»  Fourth  scale  provides  direct  reading  VSWR, 

SPECIFICATIONS:  *  Frequency  Coverage: 
1.8-30  MHz    *   Line  Impedarvce:  50  ohm 
resistive.  •   Power  Capability:  2000  W 
continuous.  *  Jacks,  Removable  Coupten  Two 
SO-239  inpul  and  output  connectors.  •  Semi* 
conduclort:  Two  power  meter  rectifiers. 

•  Accuracy:  ±(bVo  of  reading  +  1%  of  full 
scaled  *  VSWR  Intertion:  Insertion  of 
wattmeter  in  Ime  changes  VSWR  no  more  than 
1.05:1,  •  Shipping  We^ht:  3  lbs  (1.4  kg). 

•  Dimensions:  5.3~H  k  eS^W  x  7,5 '0  (13.5 
X  17,5  X  19  cmK 

Modei  1230 

LA7  Line  AmpEifier 

Line  output.  1  mW  nominal  into  600  ohm 
balanced,  adjustable  by  internal  pre-sel  level 
conirof. 

TV  interference  Filters 

High  Pass  Filters  for  TV  Sets 

More  than  40  dB  attenuation  at  52  MHz  and 
l04ver.  Protect  the  TV  set  from  amateur 
trar^smitlers  6-1 60  meters. 


Model  r^o.  1603 
Drake  TV-300-HP 

For  300  ohm  twin  lead.  New 
tefminals  for  easy  Installation. 

Model  No.  1610 
Drake  TV  75-HP 

For  75  ohm  TV  coaxial  cablei 
TV  type  "F'"  connectors 
Installed. 


** 


540  Richard  St  .  M^amfSbuFg.  Ohio  45342:  USA     Phone:  «5t3*  866-2421  •  Teiex  28B-017 


Low  Pass  Filters    4 
for  Transmitters      % 

Four  pi  sections  for  sharp  cut  off  above  the  hf 
amateur  tiands  and  10  attenuate  transmitter 
harmonics  falling  in  any  TV  channel  and  fm  band. 
52  ohm.  SO'239  connectors  built  m. 

Mod^  No  I60e  Drake  TV-3300-LP 

1000  watts  max,  below  30  MHz  Attenuation 
better  than  80  dB  above  41  MHz  Helps  TV  hf 
interference,  as  well  as  harmonic  interference. 

Model  No,  1605  Drake  TV-42'LP 

A  four  section  fiHer  designed  with  43.2  MHz  cut- 
off and  extremely  high  attenuation  in  all  TV 
chanr>els  tor  transmitters  operating  at  30  MHz 
and  lower.  Rated  100  watts  input. 


fteacJer  S&vice—  see  paje  226 


73  Magazine  •  December,  1980     31 


NEiy  PRODUCE 


AEA*S  MODEL  CK  1 
ELECTRONIC  KEYER 

The  new  AEA  Model  CK*1  iam- 
bic electronic  keyer  incor- 
porates virtyally  all  of  the  fea- 
tures of  the  renowned  AEA 
MorseMatic,  with  the  exception 
of  the  trainer  and  t>eacon 
modes.  The  CK-1  keyer  also  has 
two  preset  speeds  for  fast  recall 
and  a  stepped  variable  speed 
control  for  last  contest  opera- 
tion. The  speed  range  Is  1-  to 
99-wpm  in  one-wpnT  increments. 
The  unit  operates  from  12  volts 
dc  (plus  or  minus  3  volts  dc)  for 
maximum  DXpedition  flexibility. 
An  optional  ac  adapter  is  avail- 
able from  AEA. 

The  keyer  offers  the  contest 
operator  a  competitive  edge 
with  a  flexible  automatic  seriai 
number  generator.  The  memory 
has  a  storage  capability  of  dp- 
proximately  500  Morse  charac- 
ters. AEA's  exclusive  soft  parti- 
fioningT*^  of  the  memory  means 
that  all  of  the  memory  can  be  al- 
lotted lo  one  message  or  divided 
up  into  as  many  as  ten  separate 
messages  of  varying  length  as 
long  as  the  total  is  no  more  than 


the  500  characters.  If  you  make 
a  mistake  loading  the  message^ 
ft  can  be  easily  corrected  by  us- 
ing exclusive  AEA  editing.  The 
edit  mode  can  save  the  CW  op- 
erator time  and  frustration,  es- 
pecially in  loading  a  long  mes- 
sage. The  CK-1  memory  can  t>e 
loaded  in  the  automatic  word/ 
character  space  load  for  easy 
flawless  memory  loading  or  in 
the  real-time  load  mode.  In  ei- 
ther case,  memory  load  does  not 
initiate  until  the  first  character 
Is  sent  so  that  there  is  no  unde- 
sirable delay  in  playback.  The 
memory  playback  can  be  halted 
in  the  middie  of  a  message  for 
manual  keying  by  tapping  the 
paddle  and  resumed  where  in* 
terrupled,  or  from  the  beginning. 
When  loading  memory,  a  signifi- 
cant drop  in  sidetone  frequency 
signals  a  "memory  full"  condi- 
tion. 

Tiie  CK-1  keyer  features  a 
serial  numt}er  generator  that 
was  designed  after  analyzing 
suggestions  from  many  suc- 
cessful contest  winners.  The 
serial  number  automatically 
increments  each  time  a   mes- 


Jameco's  desk  top  enciosures. 


ABA'S  CK'l  electronic  keyer. 


sage  preprogrammed  with  a 
serial  number  is  sent.  The  serial 
number  can  even  be  repeated 
several  times  (m  another  mes- 
sage) If  the  exchange  was  not 
made*  the  first  time*  The  serial 
number  is  not  restricted  to  the 
same  position  In  a  message.  It 
can  be  placed  anywhere  within  a 
message  and  as  many  times  as 
dasired,  and  it  does  not  incre- 
ment until  a  message  is  repeat- 
ed. Any  new  serial  number  may 
be  selected  in  lass  than  three 
seconds.  The  serial  number  can 
be  loaded  with  as  Irltle  as  one 
character  space  between  it  and 
the  preceding  character. 

Like  all  other  keyers  in  the 
AEA  computerized  electronic 
keyer  line^  the  CK-1  features  in- 
dependent dot  and  dash  ratio 
adjustment  (full  weighting). 
Also,  dot  and  dash  memories 
can  be  independently  turned  on 
or  off.  For  the  operator  who  en* 
joys  operating  with  a  bug,  the 
CK-1  features  semi-automatic 
operation.  In  the  semi-auto  bug 
mode,  an  operator  can  even  load 
the  message  memories.  The 
CK-1  will  key  any  modern  trans- 
ceiver and  features  a  single  out- 
put jack  (RCA  phono  type)  for 
keying  either  plus  or  minus  key- 
jack  voltages  to  ground.  The 
CK-1  also  features  an  automatic 
tune  mode  which  can  tje  hatted 
by  tapping  any  keypad  button, 
or  the  paddle. 

The  CK-1  is  packaged  in  a 
high-impact  plastic  case,  ideal 
for  placing  next  to  the  keyer 
paddle  without  wasting  vdlu- 
able  operating  desk  space.  AEA 
engineering  has  provided  max* 
imum  rf  protection  to  avoid 
frustrating  false  keying.  All  ICs 
are  socketed  and^  like  all  AEA 
products,  each  unit  is  fully  test- 
ed  and  burned  in  at  50**  C  to 


''shake  out"  component  fail- 
ures. Mating  power  and  paddle 
connectors  are  provided. 

The  CK-1  is  easy  to  team  and 
easy  to  use,  providing  the  opera- 
tor the  maximum  amount  of  en- 
joyment with  CW, 

For  further  informatior^.  con- 
tact  Advanced  Electronic  Appti- 
cations,  inc.,  PO  Box  2160,  Bldg^ 
O&P,  200&7B6thSW,  Lynnwood 
WA  98036;  (20e)'?75^73 73/524- 
7374. 


NEW  DESKTOP  ELECTRONIC 

ENCLOSURES 

Jameco  Electronics  has  an- 
nounced a  new  Designer  Series 
of  desk-top  enclosures  to  ac- 
commodate electronic  equip- 
ment. These  stylish  enclosures 
are  designed  to  blend  and  com- 
plement today's  modern  com- 
puter equipment  and  can  be 
used  In  both  industry  and  home. 

The  unique  fouf^piece  con- 
stryction  of  the  series  enables 
easy  access  for  servicing  while 
providing  strong  protection.  The 
end  pieces  are  precision-mold- 
ed high-strength  epoxy  with  an 
internal  slot  (all  arour^d)  to  ac- 
cept both  top  and  bottom 
panels.  The  aluminum  panels 
(.080"  thick)  are  fastened  to  V*"- 
thick  mounting  tabs  inside  the 
end  pieces  to  provide  maximum 
rigidity.  For  service,  the  rear/bot- 
tom panel  slides  backward  on 
slotted  guide  tracks. 

The  aluminum  panels  are 
coated  with  an  alodine  type 
1200  finish  for  best  paint  adhe- 
sion. The  molded  end  pieces  are 
mocha  brown,  matte  finish,  but 
can  be  painted  to  match  any  col- 
or scheme. 

The  Designer  Series  enclo- 
sures  are   available   in   three 

Continued  on  page  19$ 


32     73  Magazine  •  December,  1980 


^■w»-ii 


,,,.■»•*<.* 


fi^nA. 


=  *  lf*k 


'flMHtt 


:(r\^^^f^  \i(f^  \ 


RF-4900 


Tune  m  the  Panasonic  Command  Series^ 

top-oWhe-Hne  RF-4900.  Everything  you  want  in 

short  wave  at  a  surprisingly  affordable  price. 

Like  f  uorescent  all-band  readout  with  a  five-diait 

frequency  display.  It's  so 

accurate  (within  1  kHz,  to 

be  exact),  you  can  tune  in 

a  station  even  before  it's    H  If  i fIL+^*^ 

broadcasting.  And  with  th^ 

RF-4900's  eight  short  wav 

bands,  you  can  choose  any 

broadcast  between  16  and      

31  MHz,  That's  all  short  wave 
bands.  That's  Panasonic. 

And  what  you  see  on  the  

outside  Is  justa  small  part  of  what  Panasonic  gives 
you  Inside.  Th#e's  a  double  superheterodyne 
system  for  sharp  reception  stability  and  selectivity 
as  wefl  as  image  rejection.  An  input-tuned  RF 
amplifier  with  a  3 -ganged  variable  tuning  capacitor 
for  excellent  sensitivity  and  frequency  linearity. 
Ladder-type  ceramic  fitters  to  reduce  frequency 
Interference,  And  even  an  antenna  trimmer  that 
changes  the  front-end  capacitance  for  reception 
of  weak  broadcast  signals. 

To  help  you  Control  all  that  soptristicated 
circuitry,  Panasonic's  RF4900  gives  you  atl  these 
sophisticated  controls.  Like  an  all-gear*<Jrive 


tuning  control  to  prevent  ^'backlash;'  Separate  ' 
wide/ narrow  bandwidth  selectors  for  crisp  reception 
even  in  crowded  conditions.  Adjustable  calibration 
for  easy  tunina  to  exact  frequencies,  A  BFO  pitch 


control  RF-gam  contro  for 
improved  reception  in  strong 
Signal  areas.  An  ANL  switch. 
Evan  separate  bass  and  treble 
eontfOls. 
|i  And  if  ail  that  short  wave  isn't 
enough, There^  more.  Like  SSB 
{single  sideband)  amateur  radio. 
All  40  CB  channels.  Ship  to  shore, 
Even  Morse  communications. 

AC  /  DC  operation .  And  with 

F^nasonlc's  4"  fuH-range  speaker,  the  big  sound  of 
AM  and  FM  will  really  sound  j^ig,  There's  also  the 
Panasonic  RF-2900.  It  has  most  of  thfcfeatures  of 
the  RF-4900,  but  it  costs  a  lot  less.  *•* 

The  Command  Series  from  Panasonic.  It  you  had 
short  wave  receivers  as  good.  You  wouldn't  still  be 
reading.  Ybu  d  be  listening. 

^hoft  wave  reception  wifl  vary  wtti  antenna,  wearher  corKlitfons, 
optrstof^s geographic  location  and  other  factors  An  oLitajcf* 
antenna  may  ba  r«<|ytred  for  fnajcimum  s*ioft  wave  r^f  ption 

Panasonic.  < 

just  slightly  ahead  of  our  ti  me. 


exciting  new  ideas  from  the 

world's  leading  manufacturer  of 

amateur  radio  accessories 

NEW  MFJ/BENCHER 

Keyer- Paddle  Combo  — 

"The  Pacesetter" 


MFJ-422 
Combo 


$99 


(+S4) 


MFJ^422X  Key er  only 


The  best  of  all  CVit   woiicb  —  a  deluxe 

MFJ  keycT  in  a  compact  connguraiion 
thui  fits  right  on  the  BENCHER  iambic 
paddJel  And  ytvu  can  buy  ihc  combination  or 
just  ihe  keyer  to  fit  on  your  BENCHER. 
New  MFJ  keyer  —  small  in  size,  big  in. 
features,  Curtis  8044  IC.  adjmmhk  weight 
and  lone,  front  panel  volume  ami  speed 
cam  rots  (8*50  wpm),  built-in  doi-dash 
memories^  speaker,  sideione,  and  push- 
button selection  of  semi-automatic/tune  or 
automatic  modes. 

Ultra-reliable  soLtd-state  keying:  grid- 
block,  cathode  and  solid-state  transmitters 
("300  V,  ID  niA  mux:  +300  V.  100  mA 
max).  Fully  shielded.  Uses  9  V  battery  or 
optional  AC  adapter  (S7.95  +S2> 
Beautiful  functional  engineering*  The 
keyer  mount?*  on  the  paddle  base  to  form  a 
small  (4»4iWx2^H  x  SWU  attractive  com- 
bination  that's  a  pleasure  to  lotik  at  and  use. 
The  BENCHER  puddle  is  a  best  seller. 
Fully  adjustable;  gold-plated  silver  contacts; 
iucite  paddlesi  chrome  plated  brass;  heavy 
steel  base  with  non-skid  feet. 


NEW  MFJ  4  &  8-Band  Mobile  Shortwave  Converters 


^7 


.¥rj  Ktmtt*  t  M'i.tiHkH  ( 


7 #  l#-i#-i#"i> 


—  -^1  >#-««■ 


MFJ-304 


Aiwfher  MFJ  •'first/'  these  low  cost 
mobile  SWL  converters  paivide  new  excite- 
meni  and  variety  lor  your  driving/listening 
pleasure 

Two  models  to  choose  from.  The  4-band 
••World  Explorer  1"  (,MFJ-3tM)  offen*  com- 
plete 19,  25,  ii  and  49  meter  coverage  t  the 
most  popular  HF  bands  due  to  their  distance 
cap^iiities  at  various  times  of  the  day  and 
year)-  Hear  countries  tkim  Europe,  Africa, 
Middle  East.  Asia,  the  Islands,  North  and 
South  America.  The  8 -bund  ''World 
Explorer  W  I  MFJ^30S  adds  13.  16,  4L  and 
60  meter  bands  i  for  even  greater  listening 
vaiietv. 
Compact  and  sensitive.  The  4-band  model 


I  -  ••  _•'  .#?»?•'-#- 

*^ taQBTBtw  C^ra**^ ' 


MFJ>30B 


measures  just  ^VaV^  x  P^H  x  4"D  iq  fit 
anywhere  in  your  vehicle  (the  8-band  version 
is  just  1"  wider  and  l^deeper).  Two  Jual-gate 
MOSFETS  give  these  converters  excellent 
senxithiiy  and  seleaiviiy  when  combined 
with  V our  automotive  receiver. 
Easy  to  mie,  eas^  to  install.  FUsh  a  converter 
button  to  choose  the  band,  tune  in  stations 
with  your  regular  car  radio.  To  install,  jasi 
plug  the  car  imtenna  into  the  convener  and 
insert  the  convener  cable  into  your  car  radio 
antenna  jack;  connect  the  power  lead  lo  12 
VDC. 

Listen  lo  the  ^orld  on  the  road.  Get  the 
new  MFJ  mobile  SWL  converter — '*  Workl 
lorers  1  &  IL" 


NEW  MFJ  Active  CW/SSB/Notch  Filters 


jwf 


&-.ld2 


MFJ-722 
MFJ-723 


Two  new  su|»er-^lective  filters.  The  new 
MFJ- 722  * 'Optimizer'"  offers  razor  shuFp. 
no-ring  CW  filiermg  with  switch-selectable 

bandwidihs  (80.  110,  150,  180  Hz  centered 
on  750  Hz), steep-skirted SSB filtering,  and  a 
300-3000  Hz  nmable  70  dB  noich  filter. 
The  8-jicjIe  (4-stuge!  active  IC  filter  gives 
CW  performance  no  tunable  filter  can  mutch. 
(80  Hi  bandwidth  gives  -60  dB  response 
one  octave  from  center  and  up  to  15  dB  noise 
reduction).  Thv  X  pole  SSB  audio  bandwidth 


is  optimized  tor  reduced  sideband  splatter  and 
less  QRM  (375  Hz  highpass  cutoff  plus 
selectable  lowpass  cutoffs  ai  2.5.  2.0,  and 
1 ,5  kHz,  36  dB/octave  lollofO.  Size:  5x2x6", 
New  model  MFJ -723  is  similar  to  ihe  722 
but  is  forCW  only,  has  a  60  dB  notch  tunable 
I  mm  30()-l2(K)  Hz.  and  measures  2x4x6", 
Other  models:  MFJ-72L  $59.95,  like  722 
but  less  notch;  MFJ-720,  $39,95,  like  723 
but  less  notch. 

Versatile,  all  models  plug  into  the  phone 
jack,  provide  2  watt^  for  speaker  or  can  be 
used  with  headphones.  Ail  require  9-18 
VDC.  300  mA  max  (or  110  VAC  with 
optional  AC  adapter  at  $7.95  +$2). 
Enjoy  pleasant  listening  and  improved 
readsibiiitv  with  one  of  these  new  MFJ 
niters. 


NEW  MFJ  *'Dry"  300W  &  1KW  Dymmy  Leads 

connectors;  both  rated  to  full 


MFJ-262 


MFJ-2eQ 


(+S4) 


<+S4) 


toad  for  30 
!>econds;  de-rating  curves  to  5  minuies 
Included.  Just  right  for  tests  and  fast  tune  up. 
Low  VSWR,  300\V:  ]A:\  mux  to  30  MHz. 
)  .5:1  max.  30- 160  MHz.  I  kW:  1 .5:1  max  to 
Air  Coa^d^  non-inductive  50*ohm  resistors  30  MHz.  MFJ-260  (300W)  is  just 
in  perforated  metal  housings  with  SO  239  2^x2^x7";  MFJ-262  (IkW)  is  3x3x1 3'. 


NEW  MFJ  Shortwave  Accessories 


TO  ORDEA  PflQDUCTS,  CALL  TOLL  FREC 


MFJ-KMO 

MFJ- 1040  Receiver  Preselector 
Boosts  weak  ^^igOj^lS',  rejects  out  of  band 
signals »  reduces  images.  Covers  LH-54  MHz 
with  up  to  20  dB  gain  from  low  noise 
MOSFET  circuitry.  Works  with  2  antennas 
and  2  receivers  (even  XCVRS  to  350W 
inpiit). 

Built-in  20  dB  attenuator  prevents  receiver 
overload.  Also  Includes  auto-bypitss,  deby 
contJoU  PTT  jack.  Operates  on  9  V  battery, 

34     73  Magailne  •  December,  1980 


9-18  VDC,  or  110  VAC  with  optional  AC 
adapter,  $7.95  +$2. 

Model  MFJ- 1045,  $69.95,  h  the  same  le^is 
aitenuator.  bypass,  delay.  PTT.  1  antenna  & 
I  receiver. 

MFJ-1020  Indoor  Active  Antenna 

*' World  grabber/"  nvaling  or  exceeding 

reception  of  out^^ide  long  wires. 

Unique  tuned  circuitry  with  amplificHtion 

minimizes  imennod  distortion ,  improves 
selectivity  reduces  ttoise  outside  the  tuned 
band,  even  functions  a^  ^preseleaor  w  iih  an 
external  antenna.  Covers  03-30  MHz  in  S 
hands.  Telescoping  ant,;  tune,  band,  gain, 
on-off-bypass;  l.c- '}  V  batter>,  9  18  VDC, 
or  110  VAC,  with  optu^naJ  AC  adapter  at 
$7.95  +S2.  5x2x6*^. 


mnim  cMtge 


800-647-ieOO 


For  tech.  info.,  order  or  repair  status,  or  calls 
outside  contioental  U.S.  and  inside  Miss., 
call  601-323-5869. 

«  AI  MFJ  pniducts  uncondifionaU>  guimuiteed 
for  iifie  year  i  eveept  as  imtcd) 

•  Pniducls  ordered  from  MFJ  are  returnable 
within  3()  days  for  full  refund  llesh  shipping) 

•  Add  shipping  Sc  handlini*  chargt^  in  amounts 
!«}iown  in  parentheses 

Write  for  FREE  e;)talog«  oier  60  products 

ENTERPRISES 

INCORPORATED 

Box  4«M;  Mississippi  State.  MS  A9762 


300  W  Versa  Tkiners — Versatile  Bargains 


^^^PF  '*md 


MFJ-941C 

MFJ  941C  Versa  Tuner  II 

SU  R  +  dual  range  wattmeter.  300  &  30 

waits  full  i>CiiJc,  forward  &  reflected  power. 

Sensitive  meter  measures  SWR  down  ID  5  W 

pueput. 

6-poiulJon  antenna  switch  selects  2  coax 
lines,  direct  or  through  tuner,  random/ 
bJilanced  line,  or  bypass  for  dummy  load. 

12-poi^ition   airwound    inductor,   inult-m 

Matches  ever>tliing  from   160-lOM,  di- 

poles,  vees*  randoms,  venicais,  mobile 
whip**,  beaim. 

Ea^  to  use  anywhere.  Coax  conn.,  binding 
posts,  size  8x2x6"  in  eggshell  while, 
walnyi-gmined  sides.  Mobile  bracket,  S3. 


MFJ-949B 


MFJ  949B  Versa  Tuner  II 

>Iatdies   everything    from    L8*30MH2, 

coax,  randoms,  bala  ced  lines,  up  to  JQO  W 

output ,  so  lid- SI  ate  or  tubes. 
Tunes  out  SWR  on  dipotes.   vees,  long 
wires,  vertical^i,  whips,  beams,  quads. 
Built-in  4: 1  baJun;  2IKIm,  5CI-i>hm  dummy 
load:  ^^WR  meter  and  2-ran^e  wattmeter 
(300w  &  30w). 

6" position  antenna  switch.,  12 -position 
air- wound  inductor;  coax  connectors,  bind- 
ing posis.  black  and  beige  case  10x3x7". 
4  Other  300W  Models:  MFJ-940,  $79;95, 
(+S4).  like  94 IC  less  bulun.  MFJ-M5, 
$79.<>5,  (+S4)  like  ^1C  less  ant.  switch. 
MFJ-944,  $79,95,  (+S4)  like  945,  less 
SWRM'au meter  MFJ -943,  $69,95,  (+54) 
like  944,  le&s  anL  switch. 


i'T^*. 


®  ^  ^ 


MFJ- 900 


200  W  Economy  TXiners  do  the  job  for  less 

Works  with  an>  tranjiceiver,  solid-state  or 

lube  type. 

Increases  antenna  bandwidth  to  operate 

all  bands.  50-239  -i-  buidint!  post:  5x2x6"'. 

2  OTHER  200W  MODFLS: 

MFJ-901,    $54.95,    (+S4)    like    900   bu! 

includes  4:1   balun  for  u^  with  balanced 

lines. 

MFJ-16010,   $34.95,    (-^$4)  for  random 

wires  onh\    Great  for  apanmem.    motel, 

camping,  operation.  Tlines  1 .8-30  MHz. 


MFJ-900  —  improved  but  still  low  cost 
Matches  coax,  random  wires  /  .8-30 MHz. 
Handles  up  to  200  watts  output;  efficient 
airwound  inductor  gives  more  watts  out. 


1,5  KW  Versa  Toners 

MFJ  962  VERSA  Tuner  III 

Run  up  to  1.5  KW  PEP^  match  any  feed 

line  from  1 .8-30  MHz. 

Built-in  SWR/Wattmeter  has  2000  and 

200  watt  ran|:es*  foruard  and  reflected. 

6- position  antenna  switch  handles  2  coax 

lines,  direct  or  through  tuner,  plus  wire  and 

balanced  lines, 

BuOt-in  4:1  ferrite  balun;  250  pf  6  kV 

capacitors:    12    pos.    inductor;    ceramic 

switches;  black  cabinet  and  panel . 


low  cost  power  handlers 


MFJ-d62 


.ANOTHER  US  KW  MODEL 

MFJ  %1,  S179,95.  t  +S10)  similar  but  less 
the  SWR/Wattmeter 


MFJ-S84 


3  KW  Deluxe  Antenna  Toners  —  MFJ's  best 

lines  through  tuner  and  1  coax  through  or 

direct  to  antenna*  random  wire,  balanced 

line,  and  dummy  load. 

Built-in  200  watt,  50  ohm  dumntv  load. 

BuiU-in  4:1  ferrite  baiun:  250  pf  6  kV 

capacitors:  5x14x14"  black  &  aluminum. 

Compare  this  MFJ  dduxe  3  kW  tuner 

with  anyl   You'll  agree  MFJ  gives  you 

more. 

3  MORE  3  KW  MODELS 

MFJ  981,  $199.95,  (  +  $10)  similar  to  984 

but  less  the  7-posilion  antenna  switch  and  10 

amp.  RF  ammeter.    MFJ  982,  $199.95, 

(  +  $10)  similar  to  984  but  less  10  amp.  RF 

ammeter  and  dual  range  SWR/Waumeter. 

MFJ-9S0,  $169.95,  (+$10)  similar  to  984 

but  less  antenna  switch,  RF  ammeter  and 

SWR/Wattmeier. 


MFJ  984  V#rsa  Tuner  IV 

lip  to  3  kW   PEP   and  it  matches  any 
Jeediine,   l.B-30  MHz,  coax,  balanced  or 
random. 

Exclusive  10  amp  RF  ammeter  assunes 
maximum  powder  at  minimum  SWR. 
Separate  SWRAVaitmeter,  forward  and 
reflected ,  with  2000  and  200  wall  ranges. 
IS-positloitdual  inductor, ceramic  switch. 
7-po«ition  antenna  switch  handles  3  coax 


World  leoder  in 
flntennci  Tunor/ 

15  model/ 
to  ehoo/e  from 


Other  MFJ  Shack  Favorites 

MFJ-102 

NEW  12/24  Hour  Digital  ClocL  ID  Timer 
Switch  fiom  12  hr,  to  GNfT,  to  *  seconds** 
madoui.  ID  timer  or  elapsed  imier.  WWV 
sync,  solkl-siute,  blue  0.6''  digits,  reg.  atarm 
+  indicators,  \  10  VAC,  60  Hz,  6.\2]i3*'. 


MFJ-4a4 

$139 


95 


M> 


MFJ  Grandmaster  Memory  Ke}  er  has  up 

to  twelve  25  ch.  mes^iages  plus  100,  75*  50  or 
25  ch.  messages  <4096  biis)  thai  repeat 
continuously  or  in  adjustable  pauses  (to  2 
min.):  full  controls:  8-50wpm;  solid  state 
kevingi  12-15  VDCor  tlOVAC  with  adapter 
($7.95  +$2), 


MFJ-7$2B 


MFJ  Dual  Tunable  SSB/CW  Filter;  prim- 
ary filler  has  peak,  notch,  lowpass  and 
highpass;  aux-  tlher  notches  to  70  dB  or 
p<Sks  to  40  Hz;  both  tune  300-3000  Hz  with 
bandwidth  from  40  Hz  to  flat;  constant 
output;  noise  limiien  2  inputs;  9-18  VDC  300 
mA:  or  1 10  VAC  with  adapter  (57,95  ^S2) 
i0x2\6" 


TO  onocn  products,  call  toli,  free 
800-647-1800 


For  tech.  info,,  order  or  repair  status,  or  calls 
outside  continental  U.S.  and  inside  Miss-, 
call  601-323-5869. 

•  All  M¥i  products  unconditicMially  gtiarontecd 
for  Dni;  >i*ar  t  i'\ct*pt  ds  notid) 

•  Products  orden^  from  MFJ  are  rriumahle 
within  M\  da>s  for  full  refund  (les^  shippinpii 

•  Add  sliipEiin^  ik  handling  charges  in  ammmts 
^hown  ill  purtnthi^;»eii 

Write  for  FRKE  catahjj^,  over  U\  products 

ENTERPRISES 

INCORPORATED 

BoK  4**4:  Miiisassippi  State,  MS  39762 


v^  Reaaef  ServfC^^iee  page  ^26 


73  Magazine  •  December,  1960     35 


who  Really  Invented  Radio? 

the  twisted  tale  of  Nathan  B.  Stubblefield 


Urry  K^haner  WB2NtL 
73  Associdfe  Ednor 


(decided  to  buy  the  $3-a- 
day  collision  insurance 
for  my  Avis  rent-a-car  It 
might  be  that  kind  of  as- 
signment. 

When  they  send  you  to 


unravel  the  twisted  tale  of 
Nathan  B.  Stubblefield— 
who  Murray,  Kentucky,  res- 
idents insist  invented  radio 
while  Marconi  was  just  a 
lad  — you're  bound  to  run 


into  trouble. 

As  I  neared  town,  I  first 
heard  it  on  the  AM  radio. 
The  country-western  sta- 
tion played,  appropriately 
enough,    ''Stand    By    Your 


j^ 


■•-^-ii 


Photo  A.  Family  and  friends  gathered  (date  unknown)  at  the  home  of  Nathan  B.  Stubblefield  on  North  16th  Street,  Murray, 
Kentucky.  From  left,  Sam  Stubblefield,  the  black  man,  and  then,  identified  by  numbers,  (1)  Mr,  John  P.  McEtrath;(2)  Mrs. 
lohn  P.  McElrath:  (3)  O.  L  Hale;  (4)  John  H.  Keys;  (5)  Mrs.  John  H.  Keys;  (6J  lames  M.  Cole;  (7)  Solon  Higgins;  (8)  Mrs.  Solon 
Higgins;l9)  O.  /.  Jennings;  (10)  Mrs.  Elta  Hafe  Woodruff;  and  then,  [1}  Pattie  Stubblefield;  (2)  Helen  Could  Stubblefield;  (3) 
Oliver  Stubblefield;  (4)  Victoria  Stubblefield;  (5]  Mrs.  Hattie  Keys  Beale;  (6)  Bernard  Stubblefield;  (7]  Isaac  W.  Keys;  (8) 
lames  H.  Coleman;  (9)  Abe  Thompson;  (10)  Ben  8,  Keys;  (11)  George  Catlin;  (U)  Tip  W//cox;  (13)  Nathan  B,  Stubblefield, 
and  (14)  Mrs.  Nathan  B.  Stubblefield,  (Photo  courtesy  of  Murray  State  University.) 

36     73  Magazine  •  December,  1980 


Photo  B.  Willhm  Call  K14W,  vice  president  and  trustee  of 
the  Murray  State  Urriversity  Amateur  Radio  Club,  pointing 

out  his  solar  panel  employBd  for  Field-Day  operation  this 
year.  '7t  may  have  been  magnetic  induction.  But  you  won't 

find  that  opinion  around  here  much  because  it  offends  peo- 
ple. They  want  to  believe  he  invented  radio/' 


Photo  C  Ronnie  Outtand,  22,  lives  next  to  the  private  ceme- 
tery v/here  Stubblefieid  is  buried.  "Until  recent  years  the 
grave  was  not  kept  up.  There  were  weeds  all  around  and  I 
used  to  play  here  when  t  was  younger.  There  was  a  big  corh 
troversy  about  whether  he  invented  radio-  Now  they  think 
he  did/' 


Man/'  and  its  cal]  letters 
were  WNBS:  Nathan  B. 
Stubblefieid.  These  folks 
were  serious. 

When  I  arrived  in  Murray 
and  called  the  motel,  I  saw 
ft  in  the  phone  book.  Right 
there  on  page  lit  was  a  pho- 
to of  Nathan  B.  standing  in 
the  woods,  head  cocked  to 
one  side,  holding  the 
wireless  device  to  his  ear. 
The  text  called  him  the  in- 
ventor of  the  radio- 
Add  to  that  the  granite 
monument  in  front  of  his 
homesite  and  the  state 
highway  market  pinpoint- 
ing his  birthplace,  and  there 
was  little  doubt  left 

Murrayites  meant  busi- 
ness. 

Who  was  that  man  with 
the  bowler  hat  and  handle- 
bar moustache?  And  why,  if 
he  invented  radio,  has  he 
been  largely  ignored  out- 
side of  Murray?  And  why,  if 
he  had  willing  financial 
backers  for  his  invention, 
did  he  die  a  pauper,  found 
locked  in  his  cabin  outside 
of  Murray  where  a  pet  cat 
seeking  moisture  had  licked 
out  his  dried  eyes?  And  why 
was  it  that  the  hundreds  of 
articles  written  about  Stub- 
blefieid, a  PhD  thesis,  and  a 
play  about  his  work  failed 


to  halt  the  controversy  and 
contradictions  surrounding 
this  eccentric  genius? 

It  was  frustrating  enough 
to  make  me  aim  my  silver 
Chevette  for  the  nearest 
telephone  pole  and  take  ad- 
vantage of  that  SS-anJay 
coverage. 

Instead,  I  headed  for 
Murray  State  University 
where  Dr  Keith  Heim,  head 
of  special  collections,  had 
gathered  a  respectable  file 
of  information.  Unfortu- 
nately, most  of  it  was  sec- 
ondary source  material. 

In  the  journalism  biz,  in- 
formation is  divided  into 
primary  and  secondary 
sources.  Primary  sources 
are  best  because  they  in- 
clude government  docu- 
ments, photographs,  taped 
and  transcribed  interviews 
with  people  who  witnessed 
an  event,  and  so  on.  Sec- 
ondary sources  include 
magazine,  newspaper,  and 
other  pieces  written  about 
an  event.  They  are  not  as  re- 
liable as  primary  sources 
because  they  are  second- 
hand information.  Primary 
sources  are  the  writers' 
mother  lode. 

MSU's  Stubblefieid  files 

contained  materials  (even 
from  highly  touted  publica* 
tions)   that    contradicted 


Photo  D.  Gravestone  in  Photo  C  located  behind  the  Watson 
home^  Route  fl,  about  a  mile  north  of  Murray, 


each  other  I  saw  differ- 
ences in  simple  items  such 
as  names,  dates,  spellings, 
and  attribution.  Even  Stub- 
blefield's  middle  name  was 
argued.  Smart  money  is  on 
Beverly,  but  some  pieces 
list  it  as  Bowman  (his  moth- 
er's maiden  name)  or  Bed- 
ford. Each  additional  arti- 
cle I  read  only  muddled  the 
issue. 

In  addition,  it  appeared 
that  much  of  what  has  been 
written  about  Stubblefieid 
was  based  on  the  research 
of  two  prominent  Murray 
citizens  who  are  less  than 
unbiased  about  the  role  of 
the   farmer/inventor   in   ra- 


dio's early  days. 

It  was  not  an  auspicious 

beginning. 

Some  things  are  certain, 
however.  Few  disagree  that 
Stubblefieid  was  born  in 
1860  in  Murray,  the  son  of 
Victoria  and  William  Stub- 
blefieid. He  was  a  loner  and 
had  few  friends  besides 
Duncan  Holt,  a  boyhood 
chum. 

As  they  grew  up,  they  be- 
came fascinated  by  the 
work  of  Nikola  Tesia  and 
Heinrich  Rudolf  Hertz. 
They  read  all  they  could 
about  the  burgeoning  inter- 
est in  this  new  concept  of 
electrical  waves  and  com- 


73  Magazine  •   December,  1980     37 


UNITED  STATES^P.VTENT  OFFICE, 

IJ4a(.|tlflI|}|LEnTdJ  TU  rUKN  Unn    ¥tV1t  uHE-M*  M>ili;JJiru»  Tl»  It   |J01F?i^.  tlWK  Uftl^ 


u 


H  V 


*«.  «*r'^r 


tHu,  ft  otuik  ftf  Iha  |Jini«4  J^ltaiw,  rpwltni 
•f  U»f«T,  in  lb*  «D«Httf  «r  r^liiiiiii   »ii4 
I  Slftl»  idl  tniiie^  ^1*  Hfwt^  «  ■ 
wriitJ  WifvJHB  lUtphoM.  of 

iliPtfiEftHy  ***— »*"^  ^P>>^  ^f^^n  ^M' 
iv  pMHiiif  iBotlMr  pliiwmi.  Ui^  ut  <rf  ewniwci * 
u^l  vni,  and  nwv  ]wtk^1*rh  f-vrnpfr^ 
iHndlvg  anojia  for  ■ecDFiDi;  tMrfiTioiiN  ea«A< 
numiAbtkift  bc^iwesa  mcmiii;  nehu-JM  unl 
WIT  ■IMiciDK 
II       tlw  pripei|tiil  ohjfct,  of  Ihc  inTriit^ofv  Ip  k> 

niuDJCAtiO'it  CAR  be  aBtmlitiMbftd ,  iftid  citPAliii 

fg  niii  '-"'I': 4144  4jf  Ihv  «Utiuj:i  inDciiankHmii  t^i  ti* 
*iii.t||  PtiL.E  E.'iiinpjcL. 

Jli  ihh  Mvtimn«nyinefJrHvii3|i^  --Fufiirn  I 
ia  H  [HirHpflctiTn  TU^PT.  flhavintc  rniwnii  (nr  M- 


11,  1 


■rhirh  ■•  iiMiililiri  trom  thm  sl&v  TV  tm- 
ntmmJm  i*  4if  th»  tnit  uUad  14  a  MMiUft 
wy-mtiif,  *n4  •,!  tJw  ituaaa.  i^,liKftl«d  ft 
piMiirM  9imrem  q|  «|*einMi  Mllljui  1&,  U 
.  fliiirJi  it  HHUMf  Led  bj  &  naMilB  *■»  li  M 

liti-Vny  «"  oAtr  KMim-  vf  dJMlrkiljr  hiK  ft 
nriiHiieliirii  IM  viiJh  twf'  iif  tlM  bt*^  lA-    A 


11 


4t 


4144I  tfiimwiyT  bftvc  «4q]ii}t«;livm  ti  whJl  U 
1  )■■  auntortff  of  « t witeh  £?.    Thb  *»1tch  U«p 

whirh   flartnilljr    mftUitaiha  thie  twcmixw  m 
tijfi^ull  wjlli  Mi«  OtiU  1 1 ,  hx  will  W  KVi^k'Ul  li^' 
rvlsronctf    I-j    Ki^.    I,    but    if   tkp    l«*'»t*-l).    !■  Tfl 
tktrimn  Ut  hn^ili  thi<  circuit,  it  wil9  thi<ji  cut 

lil  thp  hiLLftili  uf  fJcQirklpJ  fiTirr^   if,  And  U^ft 

trkiitfRLllt#r  17, 


■Ad  ■  ■oon  atAtrafi.      F'tC-  'I  ^  *  dLafniB  - 

ihm  boftjL     Fie  3  ■  ■  cnaw  HctiMaftl  nr*  iift 
•n  aolftrEfd  «nl*  of  tlw  vliKinr  Aid     Fv  1  ih 

ft  pien|MKlJ'r«  WH*  of  ft  »ft4- Vftf .  fllHr*lpf  ft 

tm  iTliilliliilliin  MWiili»w(ii<t  S«- 
imB  roftd  r«ifak«  tad  ft  v^^ai^  tha 

F(||.  J  B  ft  ^inwi  Twv  III  ■.  rrluclr  «^uip|»i^l 

«rf  tk  jmrraMftli  ^htdt  m  riiMW 

F%    i  M  ft  wnififfUrT* 

tv*ro  ft  MftTJi^f  ina  ftai  ft  vft|r-iliil»ai] 

'iirraift  thft  tW  pMrhilli-ii  itHlgTrnlri 
«. 

n«tiiit«|p  4tt%tiftli#  CMt- 

ID  4i  lb  iiHM  •4'  tUt 

At  Jarfwiaf  to  tht  «al»4iiiinil  tfhw*f>i»d  ta 
PIpL  I,  f!  ftiM}  ],  ft  vftMvvtf  "  ^  dMcJtfvi]. 
npiv  Tbich  a  n^ij  t  dptitftlH^  :MirTouci4- 
it^;  iVi  MLli  ^  trmrct  til  tlw  *f>t.  ft^kJ  »ff* 
ftTftblj  WFi-ftUkl  tm  p*»h«  1EI    IB  ft  e'<itil   11   iif 

*D  «ow«*t4ft  4ftftfuii  Uilc  Tbjk  tmh  »>  *iU'i  i«  n 
ei  Fig.  3,  nAutu  I  >[  ftB  mam  cftitng  >  ^'-  **  ii^- 


lh#  TflhielE  or  IkwI  9,  buL  ift*  eoit  34  tlMViil,  ft 
«liu*t]  iJi  ¥1^ .  'i,  u  mucli  UBfttiFf .  A*  fuftbsr 
LUii»irfttnl  I&  Mill]  Hfnif*,  thp  tnrrlumim 
mmmuij  OB  tb  b«Mt,  c«nM«t«  i>f  ■  criiii*- 
BuCbR  2:5,  mtti  ft  WtiTj'  ur  uiliFr  «ju]tw  of 
pWctncftl  eoBgT  »  *lwtJif  ftUy  <mmn  <l*dl.  ft*  »# 
ibnift  at  27  Uid  kftii^  ft  roopMlMtl  39  with 
oii»iillkJeftdi.i^thpfiHL  ThiivftFtfVF^ 
ft^  hmmmm^a^  »  «lk  MNt  b«il  A 
««itclik3l  Hoi^Hitftd  I4t  tlwftthrr  Itftd:,  «d 

H  tenkiftlh-  k^  IP  ft  pMil^aft  hf  ft  ipriBj  X3  14 
l#  ^-^-*—  «  rirrrl  ORiuf  liiiiii^^  c|v  1^ 
c«iWHr  ^  aari  lfe»  nil.  ikut^k  11   m^f  bf 
■Itfnrd  1»  nn,  «it  iwd  PKMifT  t4kii  «lftft 
rtrmil  thm^gti  lV  rvl,  tV  ftMinw  uf 
I  ncftJ  f^t^etf:^  antl  tbr  UftMiiyllar. 
tai  ihm.  mfmrm,  *t  H  'm  fi  ifl  J  %9 

itftCMA.  dhr  tfviirli  ^^  im  flttfvvd  AwfmUfttJJj 
ia  £tlt  tmt  Iht  fTper%*rt  11111  iJkJtiw  im  iht  InkH*^ 

UBII^  ftl^  lOUTrf  li/  vl^'tfKftl  i^ivnnjr,  whJk   ft 

iliv^  DpRTftlar  iqMBi  iV  boat  m  vvbi»  lr««Tfl£ 
ib*^  nto'luuHia  in  ite  vmdilMa  t^Miurn  i« 
F^;  J,  1iiaM#  lb*  rw«»*f  »  le  htt  car  JJ 
iftPfrfuTf  thf  <rpptftlar  ftl  fJir  Btiw^ftaTHft 
am*  !  I H-  urnnamtlrt  Ln  CJUf  «<dlttftr>  tuftAOH .    I H 

ft  vjirv  itig  rutfim  i'urmpvn'Ainir^^^^'^  P**** 
ibf  ikruu^  tisc  etal  uf  ^thL  niapiiludii  t1^ 


U7,  u-r 


wilE  be  inJuctfd  in  Uif  tai\  7*.  Hid  tJn"  iKWrh  1 

ur  Dltlll^^  JUJUMnlii  will  thu*  \m^  trftliHinlMi'ij  tu 
tbe  opi'f^lur  till  1 1  IP  tjiMl.     Uj  KVfiww  tiM' 
ftfTftogt.uiti'ut^   A^*L-|)    umy    iir    ttftllAUUlll'il 
I  Irouj  ilie  fauftt  T"  (Uf  MiliyN*  KlftHun- 


nmatnii'LJDn,  f^pfrftlinn,  ftind  luftnj   ftilvftii* 

Ih'  jtyi^ftrfiu  IM  tlk4)b«  i:lIu)J4>U  iu  ihr  ftrt.  wtiJi- 
ifM  Uirlhrv  dPNcrijjiiuu,  fttid  U  *iJl  Iw*  uiirjrf- 
4lLiLUJ  Miftl  vftnuuirlimi^pii  Ln  thr  itLKr,  hIiajj^,   i^g 


rnunication,  They  spent 
hours  reading  magazines, 
Scient'fiic  American  being  a 
favorite. 

Stubblefield  and  his  wife 
had  several  children,  but 
only  their  son  Bernard  took 


a  fancy  to  his  father's  tin- 
kering, and  he  later  became 
a  trusted  cohort. 

Another  man,  Rainey  T. 
Wells,  who  went  on  to 
found  Murray  State  Teach- 
ers College,  figured  heavily 


Photo  E.  Monument  erected  by  L  }.  Hortin  and  othefs  to 
mark  the  home  (since  torn  down)  of  Stubblefield.  The  mas- 
sive stone  was  established  at  the  edge  of  the  MurraY  State 
University  campus  in  the  1930s. 


in  the  inventor's  life  and 
was  allegedly  present  when 
Stubblefield  demonstrated 
his  wireless  invention  in 
1892.  Before  that  though, 
Stubblefield  supposedly 
told  Holt  of  his  discovery  in 
1885  However,  it  was  not 
until  January  1,  1902,  that 
he  gave  the  first  document- 
ed public  demonstration  of 
his  device  in  Murray's  town 
square. 

The  instruments  he  and 
his  son  exhibited  by  the 
courthouse  consisted  of  a 
transmitter  and  receiver— 
200  feet  a  part —  and  metal 
rods  thrust  into  the  ground 
connected  by  wire  to  both 
devices.  Coils  spread  all 
over  the  walkway. 

In  an  interview  with  a  St. 
Louis  Post-Dispatch  report- 
er ten  days  after  the  demon- 
stration,  Stubblefield  was 
quoted  as  saying:  "I  had 
been  working  on  this  ten  or 
twelve  years  before  I  heard 


of  Marconi's  efforts  (Mar- 
coni successfully  sent  ra- 
diotelegraphy  in  18%,  but 
not  voice)  or  the  efforts  of 
others  to  solve  the  problem 
of  transmission  of  messages 
through  space  without 
wires.  I  have  solved  the 
problem  of  telephoning 
without  wires  through  the 
earth  as  Signor  Marconi  has 
of  sending  signals  through 
space.  But  I  can  also  tele- 
phone without  wires 
through  space  as  well  as 
earth  because  my  medium 
is  everywhere/' 

He  never  said  what  that 
medium  was. 

Stubblefield  demonstrat- 
ed his  wireless  voice  device 
on  his  farm  to  the  reporter. 
Bernard  stayed  in  the  house 
while  his  father  and  the  re- 
porter walked  to  a  cornfield 
about  500  yards  away. 

The  reporter  wrote:  "The 
transmitting  apparatus  is 
concealed   in  a   box.  Two 


38     73Magazme  •  December,  1980 


Tbttiicof  eoifefnf  bcHlj  ^laiti^iis.  ^atJi  cod 


^ 


«tit  LyjtfiyiuJc*  »  of  |nT4i  iinpivtAiH-p.  fiir  it 
kb  hma  taoad  Lbu  wliik  t  i^«  mihII  «wb  c«ii 
b«  vad  to  tnadiEti  fani  li^  iliict  dfatiftcvj,  if 
qa*  l*t*  Ad  of  t&e  dluj^L#f  flit  ffirtb  t>  pAih 
phi^wd,  lh«  othor  QUJ  tw  irtQ'  iHHil,  iiuj 
HI iPi  h  or  HHiiila  cms.  be  trs^Ha^lt^  i«t|iH 
pkrtti^cLr  pot  ibxiAiie^  ftom  avw  to-  tW 
04h«r      llH  Hraxtda  bIt  cImHt  «iiiiili|r 

■■  ^  IW  ■■inf  ^benl  characlrr  A  r^Md-vaj 
>t  H  dackitni  luiroiiadcd  b;f  a  coil  H  of 
|»«t  niifis^lud*  ihftt  t*  attp^<if1*it  oA  unit.- 
■  Iil4>  piilFft  34  Tlii;  iH«jf>-«tAtwn  U  f-nnuiti 
I]!  ■  Lri^nEniLirr  M,  u  nuurtr  of  rVrlrKiL  en'- 

tt  *tfy  it  rutUinclcd  thcTEt*^,  ■.  frrnvrr  HR,  kUiI 
1  ■wjtcb  tl6,  wbrjfby  tbft  rvcnvnc  dt  th« 
tfuiiniilUr  «nd  40ui^^  of  tlrii^irii:*!  truri^y 
nui.  he  Lhfou'B  into  (^inruil  wilk  fIm-  c^ujI  d^J. 
Tlid  v«yei»*a  40,  vrhif^h  (*jM«rm  ott  ^^^r  rf»inl- 

lb  wmy,  v«  |iroTid«l  wiUt  mii^lJer  cuilh  41  uuJ 
lIULrumitUlA  rojiEuting  nf  rrcpivrtB  IK,  ttMV- 
■uiUn  43,  FM.tiu'i'-P'Eh  af  rleciErk'tl  4^114^1^'  44  nJiiE 
nHlsbll  ii^  4IJ  ■XThEi|.';i'd  m  ttii<  iiihrLUiT 
Mffttdj  d-rvCTJ-brd .      In  1  cjmlriii  id  ihiN  kin^i. 

M  U  will  trt  «TiU#^iit  Lh^l  IM  Dc^-up^al  »t  uue 
*iifaMJ*  m^T  ipiLppkbanr  lu-  I  he  h«nir  &  *^t- 
■toUiae,  mnA  tJw  EkHn£r  rkn  h*  IrilillHirfll 
Ifl  iMiDlher  rrbicir      jhttM  ■!  vill  b«  t'lMlMt 

■UiHA  u>d  uj  nli»kii  tk.^t<i  v^H!^  » 


I  wit,  uui  miiar  ilju'iftil*  or 
Hon,  waj  b«  rv«Pft*«l  %i>  wittnivt 
how  tii»  *Mn(  or  Hc^nifirtF^  M7  ^  tbc 
wtattffm  of  ihr  lavrBOAt). 

vb&t  1  ckuii  fci  Htm,  «ttd  nfaan^  tn  ■emle  bf 
Lrtm  Pfttmi^  «-" 

] ,  In  I.  ■iiia«iB  of  Um  ctetsclir  (kacnbed, 
tht  c^aobiMUiB  «nfc  »  inhieti^  of  «  «e^ 
jMfwiiTf>lj  «■■&  cwt  «f  m&^ioKtm^  ■ntcml  gt 
piQiiEit^  iJvfVixi^  rWlfif^  Ifia^nillin^  uhI 

Hrrtrifil  fUBii^  runrw<rmJ  la  Lh»  hb^Q  cqQ 
Mntl  CMmed  by  lh#  vrtkici*.  m  ilmiafuuj  a^ziai 
coil  nd  ■Hcrh  |[ml^r  niafini^Qde  dun  thr  ^ 
■mail  coit  haVLttf  lie  Oppoaitc  itfvtcba  c^r 
piiln,  «Jt[etLJin|(  ^^ttg  lfi«  iippoiite  fidea  uf 
lli#  p>th4al  ln.irrj  jjf  iitv  t«<hirle  ftnJ  eJ#vtt«tl 
Abovv  Kht  ^mr  i  till  I  ilri^tr  thir  vrKit:lc  aAl. 
mtvti  citttncml  triiii.3nEiLiiif  mini  niitivmg  h> 
inrtrhtni«m  connerlrid  U>  th*  invvtcr  coil  flml 
inciuiliPi;  * ftounp H^f  kiiPtvv «lectric-»l cuTrpnln 

the  cnuihiiiiAliLttt  with  1  V^^bii'ip,  Lif  a.  call  uf 
cikiiitluciltny  uiACpriat  Jrtuurtl^  Llijefvcn,  ekpc- 
triDLl  LrAzutiiiillii|{  mrniiankim,  w,  ■OLUnrc  of 
#lpctrictl  pfirivy  '■ifrmt'^'l^Hf  Ibfrplo,  frct'tv- 
ing  en pcliiukdfiji] .  ti«<rkrvN  f^it  rrmiifrUng  cltiirf 
ih-p  truuiTiitlli'ijif  iurrlivLMni  iJid  hijuKf  uf 
cbcLricii  rElil-flO  ur  tJic  rvcraviDi;  m«cb«IUhni 
U)  ibcfuii]  h  iUtmnary  «ni  <i  fir*ifr  m^g- 
BiiuUr  juiTOLJiidinf  th*  pmih  of  tf«wpl  qf  lEe 

Ifhiclf  audi   Cuniipfllittlg  B  Jllllfipld^  lJ  CCKLTQ- 

od^d',  tftrtiit  fur  ■umoiiifiit  Ibe  totj  ra  «b 
cJvtxIhI 


M 


tKl 


IVi 


TIk  niirai  is^bu  rajiitili'  df  Mrt:  StI 

tioli  tejih  drmllh  Kt  >.  atKl  tti  fn|g*-  fl  «hI  7«  *itrb 

41  m   nrfelrm  m  4lkMr|ii-r«J   ut    FB—w1wn   thctT^ 

witL  A  ctMnp&ntnclj  £rr*t  «■!  ^  h  *^p- 
pcKtcdl  c«  otPfMmU'  wk*flf  tJyr  nnrajr  tt  bf 
pg|Bi4t  vbj amJ itJtfn  49  tlM  AIKVFTCT 50 liM 

m  £t  ftod  « waiul  i»l  iHitifiiiil  b^f 

«gxplDnn«i  fdf  i^i^j  w  ti<f  fl  lImt  th*  nearwr  or 
tht  tniusniltrr  aOd  mifw  ol  fbietJiHit  «■»> 
iw^uitJidiOM'dnJrtai  wiik  [h#  CttHi^  Od* 
or  imvE  ran  i^  »  nuhru  Ifvia  it  aq(vipp«d 

#•  TiiliaiiroaJlitEdkiMimdr  lesilMj  anccifct 
SS  a  lraJi4iMU«r  34«  »  •Qtjnv  of  ctHlFtral 
inniiUTf  -17,  sfttl  ft  *wilrb  5^  for  Lturr^in^ 
eitidir  'b'  npTfi^rr  ar  ibp  ixaiumiilif  AH 
mtmt*  -it  *it»-u\vMi  vnrrfT  mia  dmut  w%th 

H  liie«ui^^  HviJI  bFrv^nt  ibit  tiMapert^ 
iiun  n1  thrse  tw<i  l*p(  fk**ril>«l  ajmteipa  ar» 
flM^UniJilly  thpMihkr  KM  thHt  C^at  wL  forth. 
*nJ  Mil.  t^tlrEtdrd  (li'W'riptinn  tliennf  ii  W 
IjcvciJ  tit  l»"  DC?'Ciiiii,ry 

From  l}l4i  fDri'jrijing.  it  in  tliDU^hl  thtl  t^ 


ff]|7  ConiMMjid  to  BBJtl  tfUUBllitlt^  JIu^lialK 

rl»clrK-*J   j(4.4Jiim   Badm^M^   an*!  ut 
I  for  rbctiKsUj  nmt^^mm  litWr  tte 
[wchanitm  wnA  trnmn  «i  rkr 

biot}  tamijcf  «  lb*  nwTBi  ■■cfaniiB  fa 

lllff  IVkd  IHIU  B#  (j^ia/li 

Mfil)  «4cirt]iral  od  iJ  _ 
■Mas  fbf  BupporiJCf  Ui*  tud  r^.  « 
^vtrkaU;  flM&Hted  tm  lb*  xmt  c«a  wid 
ciitt>E#viB|t  tzaaiautlHC  Barf  pihyi  vin^  iB#^ti- 
■XMiii  thai  ifldmfai  a  aoonw  <if  haavjr  >*bw^ 
local  rTi*riy^  mhI  «  plurabtf  i#  oLhvr  arji*- 
rat#  AtaELiirni  «unijkkiimuiJ.j  M  CtmetU||[  f^ 
taliim  w  il)^  Ehc  af  nal  end,  rafll  id  mkd  hXOir 
!rt«liotia  com  priain^  a  C04I  <jif  riimiJu^ttiii;  ifift- 
UniJ  ^pArrif  fn>tn  btii  m  ru«Kin|{  rtUiiuii 
#itb  Hid  frrral  ttiii  tndb^bw  l>|p  ^aliir,  and 
traiutrFUtliftK  ami  «vi'^ivEni>  iueirh«niiit]l  rjm- 
IvM'tC'Li  Ui  ^aid  nttier  coil  and  inrhuigfig  a 
iourci  tij  elHtll-paJ  enargy. 


>  t»^ 


|» 


lU 


l;li» 


fti^.Wf 


If 


I,  UnAi  f*Hr  ruMiTnijnimiinj;  LMi«i>i'U  » 

||lunt.llij  ci  i»1«l|ii'littN  liiilM'^  f^Pjta-lMii>  Elf  Ikit 
arTinl  I'Vll  lif  rutldui-t  111]^  uialf'iiiU  uf  jsrrjtt 
maj^itmli'.  inufunnj  1  m^i  wml  |T4  HiirBi|>  uu^lt- 
aniuih  niniHV'Inl  In  ^il  mrnai  nud  aiu]  in- 
rluiliDU  a  hHirrf  iif  Im%v>  ^^KHiiral  liirrvii 
a  |ilimhtj  j4  vrliirbw  flttivaMr  birtwi-rfi  ilir 
i}||iniiiMi'  MtlN'  «it  alfrlrlip*  nf  ihr  ^fmi  <°fMl. 
ro^  c^ffi*^  hf  aaid  irlurW  aibl  *lMbi<ri^l 
^■Itlkvi  thm  itli  t4  artkiD  *J  ihr  amal  n>id, 


ahti  tr<inpiiititiiic  and  nN-fivknH  uiH<hiJiiiiii 
oioLkiitnJ  itn  rarli  rriiK'lf-  kfUl  Ulrtuilin^  a 
irtioni'  *i{  vl^'^'lm-al  nii'4)^ 

In  Ifaliiftutiv,  Ibal  i  t-Uilh  Um-  f«ifrfiiinc 
a«  Hiiy  nail.  I  liafr  l^rvritt  aSil'^l  toy  Men*- 
iwlT  III  llw  i*r*i-nr«-  *^  i«n  iiUBii"-**! 

SAtll\\  II  'vH  Hm-KHKIJl 

J.  H  TiiLKaiv 


14 


^« 


*(? 


wires  of  the  thickness  of  a 
lead  pencil  coil  from  its  cor- 
ners and  disappear  through 
the  walls  of  the  room  and 
enter  the  ground  outside. 
On  top  of  the  box  is  an  ordi- 
nary telephone  transmitter 
and  a  telephone  switch. 
This  is  the  machine  through 
which  the  voice  of  the  send- 
er is  passed  into  the  ground 
to  be  transmitted  by  the 
Earth's  electrical  waves  to 
the  ear  of  the  person  who 
has  an  instrument  capable 
of  receiving  and  reproduc- 
ing it. 

"We  went  into  the  corn- 
field back  of  the  house.  Af- 
ter walking  five  hundred 
yards,  we  came  to  the  ex- 
perimental station  the  in- 
ventor has  used  for  several 
months.  It  is  a  dry  goods 
box  fastened  to  the  top  of  a 
stump.  A  roof  to  shed  the 
rain  has  been  placed  on  top 
of  it;  one  side  is  hinged  for  a 
door,   and  the   wires   con- 


nected with  the  ground  on 
both  sides  run  into  it  and 
are  attached  to  a  pair  of 
telephone  receivers.  The 
box  was  built  as  a  shelter 
from  the  weather  and  as  a 
protection  to  the  receivers. 
I  took  a  seat  in  the  box  and 
Mr.  Stubblefield  shouted 
'hello'  to  the  house.  This 
was  a  signal  to  his  son  to  be- 
gin sending  messages.  I 
placed  the  receiver  to  my 
ear  and  listened.  Presently, 
there  came  with  extraordi- 
nary distinctness  several 
spasmodic  buzzings  and 
then  a  voice  which  said: 
'Hello,  can  you  hear  me? 
Now  I  will  count  to  ten. 
One-two-three-four-five-six- 
seven-eight- nine-ten.  Did 
you  hear  that?  Now  I  wi 
whisper. 


ttt 


The  demonstration  con- 
tinued with  the  reporter 
and  Stubblefield  walking 
about  a  mile  from  the 
house,  the  reporter  placing 


the  rods  anywhere  he 
wished  and  hearing  Bernard 
talk  as  clearly  as  when  they 
were  500  yards  away. 

The  reporter  quoted 
Stubblefield:  "The  earth, 
the  air,  the  water,  all  the 
universe  as  we  know  it  is 
permeated  with  the  remark- 
able  fluid    which   we    call 


electricity,  the  most  won- 
derful of  Cod's  gifts  to  the 
world  and  capable  of  the 
most  inestimable  benefits 
when  it  is  mastered  by  man. 
For  years  I  have  been  trying 
to  make  the  bare  earth  do 
the  work  of  the  wires.  I 
know  now  I  have  con- 
quered it/' 


Photo  F.  The  back  of  the  monument  in  Photo  E. 


73  Mag^iine  •   December^  1 


39 


Photo  C  This  sign,  erected  by  the  state  of  Kentucky,  marks 

Stubbleiietd's  birthplace,  tronically,  it  is  almost  directly  op- 
posite the  tower  of  radio  station  WNBS. 


Stubblefield  claimed  his 
invention  would  work  for 
any  distance.  He  also  said 
that  eventually  he  would  in- 
vent a  tuning  apparatus  so 
that  many  conversations 
could  go  on  at  the  same 
time  without  interference. 
And,  he  said  it  wasn't  neces- 
sary to  use  the  ground  rods. 

The  father  and  son  team 
demonstrated  the  wireless 
device  in  Philadelphia,  New 
York,  and  Washington,  D.C. 
Newspapers  and  magazines 
documented  the  events  and 
Stubblefield's  fame  grew. 
The  March  20,  1902,  experi- 
ment was  particularly 
unique  in  that  Stubblefield 
transmitted  from  the  ship 
Bartholdi  on  the  Potomac 
River,  and  it  was  billed  as 
the  "First  Marine  Wireless 
Telephone  Demonstra- 
tion." He  transmitted  about 
¥4  of  a  mile. 

During  all  his  demonstra- 
tions, Stubblefield  em- 
ployed what  he  called  "an 
earth  battery/'  Although  no 


one  knows  for  sure  what  it 
was,  Stubblefield  claimed 
the  cell,  which  he  placed  in 
the  ground,  converted  the 
earth's  natural  current  into 
electricity.  That,  in  turn, 
transmitted  his  voice. 

tStubblefietd  received 
patent  #600,457,  March  8, 
1898,  for  a  "primary  bat- 
tery" consisting  of  a  bare 
iron  wire  and  insulated  cop- 
per wire  wound  helically  on 
an  iron  core.  The  patent 
claimed  this  construction 
increased  the  output  of  the 
couple,  using  water  as  an 
electrolyte.  A  couple  is  two 
dissimilar  metals  touching. 
He  proposed  placing  the 
battery  in  moist  earth,  but  it 
was  never  proven  to  be  the 
one  used  in  his  voice  trans- 
mission experiments,  al- 
though it  probably  was.) 

Interestingly  enough,  his 
Philadelphia  experiments 
as  well  as  his  Washington 
showings  were  successful, 
but  his  New  York  trip  was  a 
bust.  Some  observers  attri- 


W| 


Be  it  resolved  by  the  General  Assembly  of  the  Comman- 
wealth  of  Kentucky:  That  the  General  Assembly  of  the  Com* 
monweallh  of  Kentucky  hereby  publicty  recognizes  Nathan  B. 
Stubblefield.  who  was  a  native  of  the  city  of  Murray^  Calloway 
County,  Ky^  as  the  true  Inventor  ot  the  radio,  and  it  is  the  sen* 
timent  of  the  General  Assembly  that  said  Nathan  B.  Stubble- 
field \&  entitted  to  the  highest  honor  and  respect  at  the  hands 
of  the  people  of  this  Commonwealth  and  ot  this  nation  for  his 
outstanding  service.** 

— Resolution  by  the 
Kentucky  Legislature,  1944. 


bute  the  poor  performance 
to  the  hard,  dry  bedrock  in 
the  area, 

Around  this  time,  Stub- 
blefield became  quite  well 
known.  Scientific  American 
printed  an  article  about  his 
work,  and  a  coterie  of  sharp 
financiers  took  notice.  They 
saw  his  system  as  a  money- 
maker. A  group  of  New 
York  businessmen  formed 
The  Wireless  Telephone 
Company  of  America  to 
promote  the  still  unpatent- 
ed device.  Several  Murray 
men  owned  stock.  But,  for 
some  reason,  Stubblefield 
shied  away  from  the  opera- 
tion after  it  got  underway. 
It's  rumored  that  he  turned 
down  a  half  million  dollars 
for  his  invention. 

He  finally  applied  for  a 
patent  on  April  5, 1907,  and 
received  it  May  12,  1906. 
He  also  obtained  foreign 
patents. 

Then,  for  some  unknown 
reason.  Stubblefield  re- 
treated to  his  home,  disillu- 
sioned, distant  and  despon- 
dent. 

Some  say  his  invention 
was  stolen.  Others  say  he 
became  angry  at  his  back- 
ers' greed,  Stiil  others  con- 
tend he  went  mad. 

After  a  Washington  trip 
in  1912,  Stubblefield  told 
his  friends  and  associates  to 
withdraw  their  investments, 
go  away,  and  leave  him 
alone.  That  same  year  his 
house  burned  to  the 
ground. 

Later,  his  wife  and  chih 
dren  left  him  and  he  built  a 
cabin  about  six  miles  north 
of  Murray.  There  he  contin- 
ued to  tinker,  and  apocra- 
phyl  stories  abounded 
about  his  strange  experi- 
ments which  supposedly  in- 
volved drawing  energy 
from  the  earth  for  lighting. 

He  died  March  28,  1928, 
of  natural  causes,  and  two 
days  later  Horace  Chur- 
chill, country  coroner,  and 
his  son,  Ronald,  broke 
down  the  door  to  Stubble- 
field's  cabin.  He  was  dead 
on  the  floor. 

In   his   report,   Churchill 


wrote:    " he    had    been 

dead  for  some  time.  I 
wouldn't  know,  but  he  was 
pretty  stiff  and  all  Rigor 
mortis  has  set  in.  That  cat 
had  licked  out  his  entire 
eyeball  sockets.  That's 
what  the  cat  was  doing/' 

One  question  still  re- 
mains amid  all  the  conjec- 
ture, weird  tales,  and  ques- 
tionable articles.  Did 
Nathan  B.  Stubblefield  in- 
vent radio?  Are  the  people 
of  Murray  correct;  did 
hometown  boy  make  good? 

It  alt  depends  on  how 
you  look  at  it  and  who  you 
ask, 

L.  |.  Hortin,  one-time 
chairman  of  the  Murray 
State  University  iournalism 
school,  spent  50  years 
studying  Stubblefield.  He 
has  written  hundreds  of  ar- 
ticles about  the  man  and  his 
work  and  is  responsible  for 
raising  most  of  the  money 
for  a  monument  at  Murray 
State  University  honoring 
Stubblefield. 

But,  like  Stubblefield, 
Hortin  appears  distant  and 
bitter  about  the  whole  af- 
fair,  and  although  he  claims 
to  possess  documents,  affi- 
davits, and  photos  attesting 
to  Stubblefield's  inven- 
tions, he  refuses  to  let  any- 
one see  them.  "I've  been 
giving  it  out  free  for  years/' 
Hortin  said.  "I'm  tired  of 
people  making  fun  of  him 
and  getting  their  informa- 
tion wrong.  I've  decided  to 
put  it  all  together  and  write 
a  book. 

"Pardon  my  vehemence/' 
he  continued,  "but  Tve 
been  doing  this  for  50  years. 

"I  say  he  invented  radio 
about  1890,  but  I  don't 
think  anyone  really  knows. 
When  someone  questions 
me,  1  say,  'Let's  see  what 
you  have.  Who  do  you  think 
did  it?'  That  usually  quiets 
them  down, 

"Radio  is  a  device  that 
transmits  and  receives 
voice  over  considerable  dis- 
tance without  connecting 
wires/'  Hortin  said.  "Stub- 
blefield invented,  manufac- 
tured,   and    demonstrated 


40     73  Magazine  •  December,  1980 


such  a  device  and  did  so 
before  anyone  else  on  this 
planet.  That's  my  claim." 
He  described  "considerable 
distance"  as  several  miles, 

James  L.  Johnson  is  an- 
other unabashed  Stubble- 
field  booster.  In  a  1961 
speech,  the  former  execu- 
tive secretary  of  the  Murray 
chamber  of  commerce  told 
the  annual  convention  of 
The  Kentucky  Broadcaster 
Association  in  Louisville: 
"'Hello  Rainey  Hello 
Rainey/  These  four  words, 
highly  insignificant  in  them- 
selves, were  the  gateway 
that  opened  a  fabulous  in- 
dustry  in  the  late  19th  and 
early  20th  century.  These 
were  the  first  words  ever 
broadcast  by  radio.  These 
four  words  put  you  people 
in  business/' 

Following  the  address, 
the  association  presented 
the  chamber  of  commerce 
a  plaque  recognizing 
Nathan  B.  Stubblefield  as 
the  inventor  of  broadcast 
radio. 

But  Riley  Kaye  W4LMF 
holds  a  different  view  of  the 
Stubblefield  story. 

'1  think  Stubblefield  in- 
vented the  induction  tele- 
phone. He  used  loops 
above  the  ground.  There 
appeared  to  be  no  carrier. 
He  used  audio  frequencies, 
and  that's  where  the  chal- 
lenge comes  in/'  said  the 
man  who  worked  for  7 
years  as  chief  instructor  at 
RCA  and  high-frequency 
development  engineer  for 
Western  Electric  in  Chi- 
cago. 

"There  is  no  proof  that  he 
used  radiation.  There's  no 
proof  he  used  resonant  cir- 
cuits. That  would  be  radio/' 

Kaye,  9DKN  during 
sparkgap  days,  added:  "No- 
body can  challenge  that  he 
didn't  invent  the  wireless 
telephone  and  that  he  was 
the  first  to  transmit  voice 
without  wires.  He  deserves 
a  lot  of  credit  and  Murray 
can  be  proud  of  him/' 

Despite  its  limitations, 
Kaye  believes  that  Stubble- 
field's  system  needs  a  clos- 


er look,  'It's  not  a  private 
system,  but  it  is  cheap.  It 
has  a  range  of  about  five 
miles  and  seems  perfect  for 
community  civil  defense 
and  emergencies.  That 
avenue  has  not  been  pur- 
sued." 

{Note  that  in  Stubble 
field's  patent  the  ground 
rods  are  missing.  In  his  early 
work,  he  employed  a  con- 
duction system  of  tele- 
phony using  the  earth,  but 
he  later  switched  to  an  in- 
duction system.  Evidently, 
Stubblefield  confused  the 
two  media,  thinking  his 
voice  traveled  through  both 
of  them  in  a  simitar 
fashion.) 

Another  local  ham  takes 
issue  with  the  Stubblefield 
saga.  William  Call  K]4W  is 
vice-president  and  trustee 
of  the  Murray  State  Univer- 
sity Amateur  Radio  Club. 
"It  may  have  been  magnet- 
ic induction/'  he  said.  "But 
you  won't  find  that  opinion 
around  here  much  because 
it  offends  people.  They 
want  to  believe  he  invented 
radio.  On  what  I've  seen/' 
the  school's  electrical 
engineer  said,  'M  don't 
believe  he  invented  radio, 
but  one  thing  almost 
everyone  agrees  on  is  that 
Stubblefield  was  a 
genius/' 

That  he  was. 

Assaults  on  his  claims  of 
inventing  radio  have  drawn 
attention  from  Stubble- 
field's  other  brilliant  inven- 
tions. In  1888,  he  patented 
the  first  mechanical 
telephone,  and  he  linked 
Murray  with  the  system.  It 
worked  well  until  Bell  in- 
troduced his  electrical 
telephone  which  was  supe- 
rior in  voice  quality  and  re- 
liability. He  also  invented  a 
new  type  of  primary  bat- 
tery, previously  mentioned, 
whose  revolutionary  design 
stepped  up  dry-cell  technol* 
ogy  many  notches. 

So,  if  Stubblefield  didn't 
invent  radio  — and  it  ap- 
pears from  his  patent  that 
he  really  didn't  — who  did? 

According   to   many  ex- 


Photo  H.  Built  in  1948,  radio  station  WNBS  was  the  first 
broadcast  station  in  Murray.  Its  call  letters  were  chosen  to 
honor  Nathan  B.  Stubblefield. 


perts,  another  relatively  un- 
known inventor,  Reginald 
Aubrey  Fessenden,  on  De- 
cember 11,  1906,  gave  the 
first  public  demonstration 
of  voice  transmission  using 
Hertzian  waves  — radio  as 
we  know  it. 

The  exhibition  by  the 
one-time  chief  chemist  of 
Thomas  Edison's  lab  took 
place  at  Brant  Rock,  Massa- 
chusetts. He  reportedly 
told  a  journalist  in  191 5  that 
he  had  been  toying  with  the 
invention  for  some  time 
and  perfected  it  in  Decem- 
ber, 1900.  He  gradually  in- 
creased the  transmission 
range  until,  in  1904,  he 
couid  cover  25  miles  Then 
he  offered  it  to  the  Navy  for 
development, 

Fessenden  was  born  Oc- 
tober 6,  1866,  in  East  Bol- 
ton, Quebec,  and  died  July 
23,  1932,  in  Bermuda. 

So,  it  appears  that  al- 
though Stubblefield  didn't 
invent  radio,  he  was  indeed 


the  first  person  to  send 
wireless  voice  transmission 
and  suggest  that  it  be  em- 
ployed in  a  moving  vehicle 
such  as  a  boat  or  horseless 
carriage. 

But  he  holds  another  ti- 
tle, too.  He  was  the  first  to 
transmit  wireless  voice 
from  a  ship. 

In  a  1971  thesis  paper  for 
Florida  State  University  ti- 
tled 'The  Contribution  of 
Nathan  B.  Stubblefield  to 
the  Invention  of  Wireless 
Voice  Transmission/'  au- 
thor T,  Morgan  wrote: 
"Nathan  B.  Stubblefield 
was  not  the  father  of  radio 
broadcasting,  Stubblefield 
was  the  first  man  to  suc- 
cessfully transmit  and  re- 
ceive the  human  voice  with- 
out wires.  Therefore,  let 
him  be  called  the  father  of 
wireless  voice  transmission, 
for  this  title  is  truly  his/' 

Perhaps  I  should  drive  to 
East  Bolton  and  see  if  the 
residents  there  agree.  ■ 


73  Magazine  •  December,  1980    41 


CBfl  M.  Cheman  WA3UER 
1 13S  Constitution  Drive 
TaiBntum  PA  15QQ4 


In  Search  of  the  Elusive  SES 

track  solar  activity  with  this  simple 

VLF  receiver 


With    the    continuing 
and  growing  interest 
in  solar  flare  activity,  in- 


cluding tlie  predictions  for 
Cycle  21,  radio  amateurs 
and  experimenters  alike  are 


searching  for  methods  to 
follow  and  record  this 
fascinating    phenomenon 


Photo  A,  Finished  package  with  the  fine-tune  control  added^ 


The  SES  (Sudden  Enhance- 
ment of  Signal)  receiver 
that  1  am  going  to  describe 
in  this  article  provides  a 
simple  answer. 

When  a  solar  flare  occurs 
on  the  sun,  there  is  a  major 
emission  of  X-rays,  This  has 
the  effect  of  increasing  the 
electron  density  of  the  D 
layer,  immediately  enhanc- 
ing the  storm  noise  (or  the 
transmitted  signal)  to  levels 
about  twice  normal  The  ef- 
fect is  very  prominent  in  the 
LF  and  VLF  ranges.  This 
enhancement,  though  it  has 
a  rather  rapid  rise  time  as 
seen  from  the  recordings  in 
Fig.  1,  has  a  slow  decay  time 
as  the  D  layer  reestablishes 
its  normal  condition  which 
can  take  from  30  minutes 
up  to  an  hour. 

Heat  generated  by  the 
sun  in  the  daytime  periods 
expands  the  gas  in  the  D 
layer,  lowering  its  efficien- 
cy   for    radio    propagation 


42     73  Magazine  •  December,  198D 


Photo  B.  Prototype  receiver  —  front  view. 


during  the  day.  Similarly, 
the  cooling  of  the  layer 
allows  the  gas  to  contract 
increasing  its  efficiency; 
this,  of  course,  is  the  reason 
that  AM  radio  stations  are 
received  at  greater  dis- 
tances at  night.  There  also 
are  seasonal  effects  which 
occur  as  the  Earth  heats  or 
coots,  depending  upon  the 
angle  of  the  sunlight  as  it 
strikes  the  Earth. 

Receivers  used  to  record 
these  enhancements  come 
in  two  categories.  The  first 
is  an  SEA  receiver  that  is 
tuned  to  an  unused  fre- 
quency spectrum  in  the  VLF 
range— hence   the   name; 


Sudden  Enhancement  of 
Atmospherics,  The  second 
type  is  tuned  to  a  transmit- 
ted signal  in  the  VLF  range, 
and  is  the  SES  receiver  — re- 
ferred to  above.  SES  receiv- 
ers are  easier  to  tune,  and 
you  do  not  have  to  be  an  ex- 
pert to  interpret  the  record- 
ing charts. 

Building  the  SES  Receiver 

A  proven  circuit  for 
building  a  tunable  SES  re- 
ceiver is  shown  in  Fig.  2.  It  is 
basically  a  high-gain  ampli- 
fier which  is  tunable  from 
17.8  to  35  kHz.  If  you  use 
the  exact  components 
shown    on   the   schematic, 


Photo  C  Prototype  receiver— rear  view,  showing  the  shield- 
ing method  used. 


the  frequency  range  will  be 
from  17.&  to  23  kHz.  This 
circuitry  is  then  followed  by 
a  detector  and  integrator 
and  finally  by  adc  amplifier 
which  brings  the  dc  signal- 
related  current  up  to  a 
proper  level  to  operate  an 
analog  meter  or  a  recording 
device. 

The  recorder  recom- 
mended is  a  model  288 
Rustrak  (0-100  uA)  with  a 
chart  speed  of  1"  per  hour, 
although  1  have  used  Ester- 
line  Angus  0-1 -m A  chart 
recorders  successfully.  The 
receiver    has    more    than 


enough    gain    to    peg    a 
0-1 -m  A  meter. 

All  of  the  parts  used  in 
the  construction  of  the  re- 
ceiver are  standard,  with 
the  exception  of  the  induc- 
tor coils.  These  inductor 
coiis  (Miller  6319)  are  high- 
Q  types  and  are  Litz-wire 
wound.  They  can  be  ob- 
tained from  Bell  Industries, 
J.  W.  Miller  Division,  19070 
Reyes  Avenue,  PO  Box 
5825.  Compton  CA  80224. 

Wiring  of  the  circuit  is 
not  critical;  however;  I  sug- 
gest that  a  socket  be  used 
to  mount  the  IC  amplifier.  A 


o 

a 

o 

c> 

o 

O 

/"■\ 

o 

i"i 

Q 

wtH 

iH 

night 


o 

O 


^ 


/ 

Sffftffse 


o 

o 

o 

o 

o 

o 

o 

o 

^ 

tn 

<J3 

r^ 

te.-— ft 


fia  ne 

a  2 


daytime 


/"^fyj 


sunsei 


21.aKhz 


:iiissL^ 


^Vj-.f;  •■;■?■<  :■ 


Fig.  1.  Actual  recordings  showing  characteristic  fast  rise/slow  decay  times. 


73  Magazine  •  December,  1980     43 


Photo  D.  Shield  removed  to  show  coils,  U,L2,  and  gain  pot 


substitution  for  the  RCA 
CA3035  amplifier  array  is 
the  more-readily-available 
Sylvania  ECG  785  Both 
wideband  amplifier  arrays 
are  made  up  of  three  irv 
dividual  ultra  high-gain 
amplifiers.  These  amplifiers 
have  low  noise  characteris- 
tics, can  be  operated  either 
independently  or  in  cas- 
cade, and  have  excellent 
high  cascade  voltage  gain— 
129  dB  at  40  kHz.  The 
output  transistor  [RCA 
SK3019)  can  be  replaced 
with  either  a  Sylvania 
ECC'1 08  or  a  GE-214.  Power 
supply  requirements  are  93 
V  dc  for  optimum  opera- 
tion, but  any  well-regulated 
12-volt  power  supply  can 
be  used.  The  higher  the 
voltage,  the  ''choppier"  the 
trace  will  become  on  the 
recording. 


Initial  Tuning  Procedure 

Run  the  cores  of  LI  and 
L2  completely  in.  Proceed 
to  turn  the  gain  control  (Rl) 
Vi  turn  clockwise.  Connect 
the  antenna  (preferably  an 
Ift-foot  vertical  or  an  8-foot 
CB  whip)  to  the  receiver  in- 
put jack.  Ground  the  receiv- 
er using  a  good  earth 
ground.  Connect  an  oscillo- 
scope (using  the  vertical  in- 
put) to  the  test-point  Jack 
on  the  receiver.  Turn  out  LI 
one  full  turn.  A  large  sine 
wave  will  appear  on  the 
screen,  showing  a  promi- 
nent ''hump." 

If  you  have  used  the 
components  specified  in 
the  schematic,  this  wil  I  be  a 
signal  coming  from  17.8^ 
kHz  [NAA,  Coutler,  Mail 
The  format  of  thi: 
ted  signal  is  such  that  it  can-^ 


C8  ifHP  trr 


V 


0 


5MEL0ED 


Jj^Oi 


'cam 


h^0^ts 

CJ^£.3,'4,5,B.9,II    ARE 
ALL    OOt   CEflAMFC 

0  ■OUTSIDE  -W I  WD  I  Me 


if  lOli 


CM    


not  be  used  in  solar  flare 
studies,  so  continue  to  turn 
the  core  of  LI  out.  The 
17.8-kHz  signal  should  drop 
out  and  a  small  hump  wilL* 
appear.  This  will  be  18,6^ 
kHz— NAA's  1-megawattyJ 
station.  If  the  signal  has 
good  strength,  by  all  means 
record  it.  If  the  signal  is 
weak,  as  in  my  case,  con- 
tinue with  the  turning  by 
opening  the  core  of  LI  until 
it's  almost  fully  open  or  un- 
til a  large  signal  reappears 
on  the  screen.  -s,^^ 

This  signal  will  be  21,4 
kHz  (NSS)  radiating  aj 
200-kW  signal  This  station 
is  an  excellent  choice  for 
flare  propagation  recording 
for  a  number  of  reasons. 
First,  it  is  easy  to  access 
(you  cannot  mistake  the 
signal)  and  tuning  is 
straightforward.  Second, 
my  records,  along  with  the 
records  at  the  AAVSO 
{American  Association  of 
Variable  Star  Observers] 
show  that  a  lot  of  small 
flares  are  recorded  at  this 
frequency  while  they  are 
often  completely  missed  at 
other  low  frequencies. 

If  an  oscilloscope  is  not 

available  for  tuning,  the 
receiver  can  be  tuned  with 
a  0=200  uA  meter  placed 
across  the  receiver's  record- 
er output  terminals.  When 
coil  LI  is  turned,  a  promi- 
nent peak  will  indicate  that 
you  have  tuned  the  signal. 

Final  Tuning  Procedure 
Disconnect  the  oscillo- 


tp 

Q 


CI  a 

15V  DC 


IN34 


f^    IM54 


■4  *  ^ 


CI3 


OhDOmA 

rusthak 

OR 
METER 


-o-*^ 


/f?   EARTH  GrK7U»tD 


Fig.  2.  Circuit  for  a  tunable  SES  receive/. 


scope  or  tuning  meter  and 
place  a  recorder  at  the 
designated  terminals.  Turn 
up  gain  control  Rl  to  give 
you  a  mid'Scale  reading  of 
either  50  uA  or  close  to  1 
mA  if  you  are  using  a 
0-1 -mA  recorder.  By  turning 
LI  in  and  out  a  few  threads, 
peak  the  signal.  Fine-tune 
the  signal  with  5-6  turns  of 
L2.  In  some  cases,  it  wtll 
show  a  prominent  increase; 
in  others,  it  wil!  not.  (Since 
all  coils  are  not  the  same, 
the  tuning  of  L2  may  vary.) 
To  test  for  oscillation, 
disconnect  the  antenna;  the 
signal  on  the  recorder 
should  drop  to  zero  or  al- 
most to  zero.  When  the 
ground  is  disconnected,  the 
signal  definitely  should 
drop  to  zero. 

Other  Hints  and 
Correlation  ideas 

The  receiver  itself  can  be 

housed  in  any  standard 
metal  or  wood  enclosure, 
but  be  sure  to  make  use  of 
adequate  shielding  around 
the  inductor  coils  to  ensure 
proper  mixing.  I  use  small, 
lined  aluminum  cans  at- 
tached to  brackets  which 
are  mounted  to  the  circuit 
board.  These  make  excel- 
lent shields. 

Good  correlation  on  an 
official  basis  for  flare  re- 
cording  and  verification 
may  be  obtained  by  send- 
ing for  a  weekly  solar  data 
bulletin  (free)  printed  by  the 
government  Write  to  the 
Space  Environment  Ser- 
vices Center,  Space  En- 
vironment Laboratory  ERL, 
NOAA,  Boulder  CO  80302. 
Ask  for  the  preliminary 
report  and  forecast  of  solar 
geophysical  data 

Circuit  boards  for  build- 
ing the  receiver  are  avail- 
able from  me  for  $8.00 
each,  plus  postage 

For  those  further  Inter- 
ested in  solar  flares  and 
flare  recording,  my  Hand- 
book of  Solar  Flare  Monitor- 
ing and  Propagation  Fore- 
casting is  available  from 
Tab  Books.  ■ 


44     73  Magazine  •  December,  1980 


the  microcomputer-contfolled 
appointment  clock 


NEW 

First  Time  Offer 


i^^ 


—  NOT  A  KIT 

Limited  Offer  by 

Hal-Tronix 

only  $49.95 
plus  $2.00 
Shipping  &  handling  charge 

FEATURES: 


>TirneTr: 
Send  15^ 


•  Sleek   modern   styling   to  complement  any 
home  or  office  decon 

•  Tells  the  time. 

•  Tells  the  date  and  year. 

•  Gp-timer  to  60  minutes,  59  seconds  with 
pause. 

•  Alarm  to  ring  at  the  same  time  everyday. 

•  Daily  appointment  sets  appointments  for  the 
next  23  hours,  59  minutes, 

•  Future  appointmerrts  up  to  one  year. 

•  Dimmer  switch  for  display. 

•  iviemory  will  hold  up  to  30  appointments* 

•  Llthlunn  power  cell  to  retain  memory  during 
power  outage. 

•  Appointments  entered  out  of  chronological 
order  will  be  stored  in  chronological  order. 

•  Colon  flashes  once  each  second. 

•  A.WJP.m.  Indicator, 

•  Plugs  Into  any  wall  outlet. 

•  Easy  to  read  vacuum  fluorescent  display* 

•  Extremely  accurate  quartz  crystal  clocks 

EFFICIENT.  REMARKABLE. 

rac  sold  and  dl$tritjuted  by  HAL-TRONIX.    Dealers  we! come. 


Stamp  or  S.A.S.E.  for  Information  and  flyer  on  other 
HAL-TRONIX  products.  To  order  by  phone*  1-010-265-1762. 


"HAL"  HARQU>  C.  NCWLAND 
W8ZXH 


Hal-Tronix 

P,0.  Box  1101 
Southgote,  Ml  46195 


1^31 


SHIPPING 

INFORMATIONi 


ORDERS  OVER  120.00  V1LL  DE  SHIPPED  POSTPAID  EXCEPT 
ON  rTEMS  WHERE  ADDITIONAL  CHAR(SES  ARE  REQUESTED. 
ON  ORDERS  LESS  THAN  120.00  PLEASE  INCLUDE  ADDniON- 
AL  Sl.^D  FOR  HANDLING  AND  MAILING  CHARGES. 


HD-73  HEAVY-Dirn 

ROTATOR 


with  exclusive  Dual-Speed  Control! 

For  antennas  up  to  10.7  sq.  ft,  of  wind  load  area>  Mast 
support  bracket  design  permits  easy  centering  and  offers 
a  positive  drive  no-slip  option.  Automatic  brake  action 
cushions  stops  to  reduce  inertia  stresses.  Unique  control  unit 
features  DUAL-SPEED  rotation  with  one  five- position  swrtch, 
SPECIFICATIONS:  Max.  wmd  load  bending  moment— 10,000 
in.-lbs.  {side-thrust  overturning);  Starting  torque  —  4D0  in.* 
lbs.;  Hardened  steel  drive  gears;  Bearings  -100-%"  diam- 
eter (hardened);  Meter  —  D'Arsonval,  tatit  band  (back- 
lighted). There's  much,  much  more  —  so  get  the  whole  story! 


1        Mail  this  coupon  for  complete  details!  >^3i4  [ 
I    VCd  I— '  ^^^^  ^^  complete  details  on  the  HD73! 


Q  Give  me  the  name  of  my  nearest  dealer! 


NAME 


ADDRESS 


CITY 


STATE 


ZIP 


1 


^^^W    The  ALLIANCE  Manufacturini  Co.,  Inc.,  hWi^ntt,  Ohia  44601 

>|^^  A  NOHTtt  AMEfllCAM  PHILIPS  COMPANY 


I  %|^^  A  NOHTtt  AMEfllCAM  PHILIPS  COMPANY  | 

I   llBkBr  o-l  th«  famiijus  Anttnna  HotBlor  .  . .  Alliance  T«nn*-RplDr<*  . .  .  "TV*  S*tt«r  Color  G*ltirr'| 

^^^^    .^^^H    ^^^^  ^^mm^  ^^^^  ^^^^  ^^^^    ^^^^  A^^^H  ^^^^  ^^^^  -^^^H    ^^^H    A^^^i^  ^h^^  ^^^AA  ^^^^  t^^mm    ^^^H    ^^^^  ^^^J 

I  t:  >S3fl  Th*  AlHsrase  Mto-  C*i-  'fi*-     I 


t^  Hesdef  Service — see  page  22$ 


73  Magazine  •   December,  1980     45 


Don  hbody  WA0PBQ 

8413  Riggs 

Overland  Park  KS  66212 


An  Even  Better  IC  Timer 

better  than  what? 


Photos  by  Joe  Woelfel 


This  is  the  front  of  the  iimer.  Three  7-segment  LEDs  are  behind  a  red  plastic  filter  mounted 
in  the  upper  left  section.  One  digit  is  to  the  left  of  the  letters;  two  are  on  the  right  Discrete 
LEDs  behind  the  H-M  and  M-5  indicate  whether  the  tinner  is  in  the  hours/minutes  or 
mmutes/seconds  mode.  They  are  controtled  by  the  toggle  in  the  upper  center.  Thumbwheel 
switches  are  in  the  upper  right  section.  The  white  frame  is  a  piece  of  plastic  covering  a 
mistake  made  when  cutting  the  hole.  Lying  on  top  of  the  timer  is  the  remote  switch  box  con- 
nected by  a  4-wire  cable.  Woodgrain  contact  vinyl  was  used  to  cover  the  bare  aluminum  of 
the  Radio  Shack  cabinet  Labels  are  dry  transfer  letters. 

46     73  Magazme  •  December,  1980 


This  project  is  a  good  ex- 
ample of  the  use  of 
elaborate  means  to  accom- 
plish a  simple  task.  Having 
become  hopelessly  hooked 
on  the  fun  and  logic  of  TTL 
devices,  I  was  intrigued  by 
an  article  by  Kenneth  Wil- 
liams WB3ELV,  in  73,  Sep- 
tember, 1978,  He  had  de- 
signed a  circuit  board  for  a 
10-minute  ID  timer  de- 
scribed by  Ken  Henry 
K3VTZ  in  a  May,  1977,  73 
article.  His  timer  used  a  sin- 
gle 7-segment  readout  and 
cycled  through  lOminute 
intervals. 

After  reading  most  of  the 
series  of  73  articles  on  how 
to  use  ICs,  by  Alexander 
McLean  WA2SUT,  [  decid- 
ed it  would  be  more  fun  to 
have  a  timer  which  indicat- 
ed minutes  and  seconds,  t 
had  a  10-m in ute  timer  work- 
ing on  the  breadboard  when 
I  found  another  73  article, 
"Build  a  Unique  Timer/'  by 
Marc  Leavey  WA3AJR  [Au- 
gust 1977).  His  timer,  built 
for  darkroom  use,  will  time 
to  either  99  seconds  or  99 
minutes  and  used  a  555  as 
the  timebase.  That  article 
exposed  me  to  the  7485 
comparator    chip    and 


thumbwheel  switches.  My 
timer  grew  out  of  all  these, 
along  with  some  basic  de- 
sign concepts  from  The  TTL 
Cookbook. 


My  timer  will  do  every- 
thing these  wfll  do  and 
more.  It  will  run  to  any  user- 
selected  time  up  to  9  min- 
utes, 59  seconds  by  seconds 
or  it  will  run  from  1  minute 
to  9  hours,  59  minutes  by 
minutes  At  the  end  of  the 
selected  interval,  an  alarm 
may  be  sounded  and  a 
115-V  ac  appliance  may  be 
turned  on  or  turned  off.  The 
timing  sequence  may  be  in- 
terrupted by  a  manual  re- 
set. The  timer  may  also  be 
used  as  a  stopwatch  or  an 
elapsed-time  recorder.  It 
may  be  stopped  and  restart- 
ed with  or  without  resetting 
to  zero 

The  block  diagram,  Fig. 
1,  shows  the  general  opera- 
tion of  the  timer.  A  wave- 
shaper  converts  60-Hz  sine* 
wave  current  from  the 
transformer  secondary  into 
the  square  wave  required 
by  TTL.  A  gate,  controlled 
by  a  start/stop  flip-flop, 
routes  these  pulses  to  the 
divider  chain  which  divides 
by  60  twice  to  produce  one 
pulse  per  second  and  one 
pulse  per  minute.  These,  as 
selected  by  the  mode 
switch,  go  to  the  counter/ 
driver/display  section 
which  shows  minutes  and 
seconds  or  hours  and  min- 
utes. The  output  of  the 
counters  is  compared  with 
the  settings  of  external 
thumbwheel  switches. 
When  these  match,  an 
alarm  sounds  and  all  divid- 
ers and  counters  are  reset 
to  zero. 

The  wave-shaper  consists 
of  two  resistors,  a  diode, 
and  a  Schmitt  trigger  cr re u it 
using  two  inverters  on  Ul.  I 
have  seen  circuits  which 
used  only  a  diode  to  clip 
the  sine-wave  output,  but  I 
did  not  get  dependable  trig- 
gering until  I  included  the 
trigger.  Most  TTL  devices 
requ  ire  negative-going 
pulses  and  tend  to  get  con- 
fused unless  they  see  very 


fast  high-to-low  switching. 
The  circuit  shown  does  not 
produce  a  50%  duty  cycle 
square  wave,  but  the  nega- 
tive-going  pulses  follow 
each  other  at  a  60-Hz  rate. 
Switching  time  is  very 
short— on  the  order  of  a 
few  nanoseconds. 

The  shaper  output  goes 
to  the  divider  chain  through 
a  gate  on  U2  controlled  by 
the  start/stop  flip-flops.  U3 
and  U4  divide  by  6  and  10 
and  produce  one  pulse  per 


CaJ  J%  Dt"  Ei 

ftn-^e 

trt 

en 

V**    1    fr 

1 

1 

STAflT/STOf* 
FF 

RESET  Ff 

1 

1- 

AtARM 

MODE 
1         S^MCH 

SCLECTOR 

COUPAflATORS 

fiJ£JH  At 

r}i>tu>rA4 

Cnil^TFB^ 

u 

Fig.  1.  Biock  diagram. 


60**t 
AC     H* 


Fig,  2.  Schematfc. 


73  Magazine  *  December.  1980    47 


Interior  view  showing  the  inside  of  the  front  panel  and  part 
of  the  main  circuit  board.  Displays  are  upper  right;  thumb- 
wheel switches  are  at  the  left.  The  7447  display  drivers  and 
segment  current-limiting  resistors  are  in  the  lower  center. 
Below  them  are  the  7490  and  7492  decoders.  The  unortho- 
dox wire  connections  to  two  of  the  drivers  were  added  to 
correct  errors  on  the  circuit  board.  Because  of  omitted  foil 
connections,  wires  were  forced  into  the  sockets  beside  IC 
pins. 


second.  This  is  further  divid- 
ed by  6  and  10  by  U5  and 
U6  to  produce  one  pulse 
per  minute. 

The  one-per-second  or 
one-per-minute  pulses,  as 
selected  by  the  mode 
switch,  S5,  are  fed  to  the  di- 
vider chain  consisting  of 
U9,  U10,  and  U11.  Each  of 
these  feeds  a  7447  driver 
and  a  7-segment  LED  read- 
out. The  outputs  of  U9, 
U10,  and  U11  are  compared 
with  the  settings  of  three 
BCD  thumbwheel  switches 
by  U15,  U16,  and  U17, 
When  those  outputs  match, 
pin  6  of  U17  goes  high,  re- 
sets all  counters  to  zero, 
sets  off  an  alarm,  and  trips 
an  SPOT  relay  which 
switches  one  115-V  ac  out- 
let on  and  another  off. 

U7  is  wired  to  form  two 
interconnected  R-S  flip- 
flops.  One  is  used  to  start 
and  stop  the  timer  by  oper- 
ating a  gate  on  U2  which 
controls  the  60-Hz  pulse  to 
the  divider  chain.  This  per- 
mits stopping  and  restarting 
the  timer  without  resetting 
the  counters  to  zero.  Inter- 
rupting the  count  at  this 
point    introduces    a    mini- 


mum of  error.  The  other 
flip-flop  is  used  to  control 
the  reset  line  to  all  dividers 
and  counters.  When  pin  6  of 
U17  goes  high,  pins  3  and  4 
of  U7  and  the  reset  line  go 
high.  This  stops  all  counting 
and  resets  the  dividers  and 
counters  to  zero.  The  reset 
line  stays  high  until  the  start 
button  is  pushed,  which 
drives  the  reset  line  low  and 
permits  the  counters  and  di- 
viders to  operate.  Closing 
the  start  switch  also  sets  the 
reset  flip-flop  so  that  it  is 
ready  to  accept  a  new  pulse 
from  U17,  The  reset  line 
also  can  be  driven  high 
manually  by  S3. 

U10,  a  7492,  needed 
some  special  treatment.  To 
show  tens  of  seconds  (or 
miniJtesX  the  counter  has  to 
count  to  5  and  reset  to  zero 
on  the  sixth  count.  On  the 
sixth  count,  a  negative-go- 
ing pulse  must  be  provided 
to  the  input  of  U11,  the  min- 
utes (or  hours)  counter.  Pin 
9  of  the  7492  goes  high  on 
the  fourth  count  and  low  on 
the  sixth  count,  U11  ignores 
the  positive-going  pulse 
and  is  triggered  by  the  nega- 
tive-going pulse.  However, 


Rear  view  showing  jylacement  of  tone  duration  and  volume 
pots,  voltage  regulator,  and  external  connections.  The  four- 
hole  socket  at  the  left  is  for  the  remote  switch  box.  At  the 
right  are  two  115  V  ac  sockets,  "'THEN''  is  hot  at  the  end  of 
the  pre-set  timing  period.  "NOW  is  hot  during  the  timing 
period. 


if  left  to  proceed  through  its 
normal  count  cycle,  the  pin 
9  output  would  remain  low 
for  10  more  counts,  trigger- 
ing U11  only  every  second 
nninute  (or  hour). 

There  is  a  solution, 
though.  Pin  8  goes  high  on 
the  sixth  count,  so  that  out- 
put can  be  used  to  reset  the 
counter  to  zero,  and  U11  is 
triggered  every  sixth  count. 
Connecting  pin  8  of  U10 
directly  to  its  reset  pins,  6 
and  7,  interfered  with  the 
operation  of  the  system-re- 
set from  U2.  A  diode  be- 
tween pins  7  and  8,  block- 
ing the  system-reset  pulse 
from  U2,  solved  the  prob- 
lem. 

The  7447  BCD  drivers 
provide  leading-zero  blank- 
ing. When  pin  5  of  the  most 
significant  digit  is  grounded 
and  pin  4  is  connected  to 
less  significant  digits,  the 
readouts  will  not  display 
meaningless  zeros.  1  con- 
nected pin  5  of  U14  to  the 
reset  line  instead  of  to 
ground;  thus,  leading  zeros 
are  blanked  only  when  the 
timer  is  counting.  This  gives 
a  visual  indication  of  the 
state  of  the  timer. 

1  also  wanted  visual  indi- 
cation of  whether  the  timer 
was  in  the  hours/minutes  or 


minutes/seconds  mode.  The 
obvious  solution  was  to  use 
discrete  LEDs  as  indicators. 
Also,  in  the  hours/minutes 
mode,  the  readout  changes 
only  once  per  minute.  To 
provide  assurance  that 
something  was  really  hap- 
pening, I  made  one  of  the 
readout  decimal  points 
blink  at  a  1-Hz  rate.  Switch- 
ing all  those  functions 
would  be  simple  with  a 
3-pole,  2-po5ition  switch. 
However,  switches  are  ex- 
pensive; ICs  are  cheap. 
With  the  use  of  gates  on  U2 
and  inverters  on  U1,  the 
hours/minutes  and  min- 
utes/seconds timing  pulses, 
the  LED  indicators,  and  a 
pulsing  decimal  point  for 
hours/minutes  are  all 
switched  with  an  SPOT  tog- 

When  S5  is  in  the  min- 
utes/seconds position,  pin 
10  of  U2  is  high,  allowing 
the  1-Hz  pulses  to  reach  the 
counter  chain.  Also,  pin  5  of 
U1  is  high  and  pin  6  is  low, 
providing  a  ground  for  the 
minutes/seconds  indicator 
LED.  In  the  hours/minutes 
position  of  S5,  pin  13  of  U2 
is  high  and  one  pulse 
reaches  the  counter  each 
minute;  pin  4  of  U1  is  low, 
providing  a  ground  for  the 


4Q     73  Magazine  •  December,  1980 


indicator,  and  pin  4  of  U2  is 
high,  passing  one  pufse  per 
second  to  the  decimal  point 
of  the  units  readout. 

All  this  switching  caused 
a  small  problem.  I  discov- 
ered that  in  the  hours/min- 
utes mode,  the  timer  indi- 
cated 1  minute  after  48  sec- 
onds had  elapsed.  Just  a  lit- 
tle examination  of  the  7490 
logic  table  revealed  the 
reason.  Pin  11  of  a  7490  is 
low  for  8  counts,  high  for  2 
counts,  then  goes  low.  That 
negative-going  pulse  trig* 
gers  other  devices.  How- 
ever, I  had  routed  the 
pulses  through  a  7400  gate 
and  inverted  everything. 
Thus,  the  positive-going 
pulse  at  the  eighth  count  of 
U6  was  seen  at  the  input  of 
U9  as  a  negative-going 
pulse.  Of  course,  each  sue* 
ceeding  ^'minute"  was  60 
seconds  long.  The  problem 
was  corrected  by  running 
the  minutes  output  from  U6 
through  an  inverter  on  U1, 

The  same  inaccuracy  ex- 
ists with  the  1-Hz  output 
from  U4,  The  first  "second" 
Is  only  .8  second  long.  I  de- 
cided to  live  with  that  error, 
because  no  more  inverters 
were  available  without  add- 
ing another  fC.  By  now  f 
realized  that  the  whole 
problem  (and  some  others) 
could  have  been  avoided 
by  using  a  7408  for  U2  in- 
stead of  a  7400  I  did  not 
have  a  7408,  and  my  circuit 
board  was  afready  laid  out. 
Oh,  welL  Next  time! 

S4,  an  SPST  toggle,  was 
added  to  increase  the  versa- 
tility of  the  timer  When  it  is 
closed,  the  reset  and  start 
push-buttons  are  shorted 
together.  Pressing  either 
switch  resets  everything  to 
zero  and  immediately  starts 
a  new  timing  sequence.  The 
alarm  still  sounds  at  the  end 
of  the  selected  interval,  but 
it  is  not  possible  to  stop  and 
restart  the  count  without  re- 
turning to  zero.  This  mode 
also  effectively  disables  the 
nS-V  ac  switching  function 
as  the  stop-reset-start  se- 
quence is  so  fast  that  the 
relay  does  not  trip.  I  called 


the  closed  position  of  54 
"auto"  and  the  open  posi- 
tion ''manual"  The  strange 
location  of  the  switch  hap- 
pened because  this  feature 
was  not  installed  until  the 
project  was  compfete  With 
a  little  forethought,  the 
switch  could  have  been 
located  in  a  better  place. 

Two  115-V  ac  sockets  are 
provided  for  the  operation 
of  external  appliances  such 
3ts  lights,  radio.  TV,  etc.  An 
SPOT  relay  with  a  6-V  coil 
switches  the  outlets  on  or 
off.  One  is  on  and  one  is  off 
during  the  timing  sequence 
This  is  reversed  at  the  end 
of  the  selected  interval.  Pin 
1  of  U7  is  high  during  the 
timing  period,  so  that  out* 
put  was  used  to  make  a 
2N2222A  transistor  switch  5 
V  dc  to  the  relay.  A  1N914 
diode  across  the  relay  coil 
reduces  voltage  spikes 
which  occur  when  the  coil 
is  switched  out. 

The  alarm  circuit  is  built 
around  a  556  timer.  This  is  a 
dual  555  with  one  part  serv- 
ing as  an  oscillator  to  pro* 
duce  a  tone  and  the  other 
as  a  timer  to  set  the  dura- 
tion of  the  tone.  Pin  6  must 
be  low  to  trigger  the  multi- 
vibrator, so  the  high  output 
from  pin  6  of  U17  is  in- 
verted through  U1.  The 
pitch  of  the  alarm  tone  may 
be  adjusted  with  a  100k  pot 
mounted  on  the  circuit 
board.  The  duration  of  the 
alarm  tone  may  be  varied 
from  a  fraction  of  a  second 
to  several  seconds  with  a 
50k  pot  mounted  on  the 
rear  of  the  cabinet.  I  placed 
a  2.2k  resistor  in  series  with 
the  pot  so  that  there  would 
be  some  tone  when  the  pot 
was  at  minimum  resistance. 
The  volume  of  the  alarm 
tone  may  be  adjusted  with 
a  Ik  pot  on  the  rear  of  the 
cabinet.  The  alarm  can  be 
completely  disabled  with  a 
toggle  switch  mounted  on 
the  front  of  the  cabinet.  I  in- 
cluded an  LED  to  indicate 
when  the  alarm  is  enabled. 
If  the  indicator  were  omit- 
ted, an  SPST  switch  could 


tnteriof  view  of  the  timer.  The  power  supply  and  ac  switch- 
ing relay  are  on  the  left.  Displays  are  at  lower  left;  thumb- 
wheel switches  are  at  tower  right  The  7485  comparators 
and  7405  inverters  are  on  a  small  circuit  board  mounted  ver* 
tically  at  the  right.  The  unorthodox  wires  on  the  ICs  in  the 
upper  right  and  lower  left  were  used  to  correct  circuit  board 
mistakes.  Some  foil  connections  were  omitted,  so  wires 
were  forced  into  the  sockets  beside  the  IC  pins. 


be  used. 

The  switch  input  to  the 
7485  comparators  requires 
a  BCD  complement.  I  have 
read  that  complement 
mode  switches  are  avail- 
able, but  1  could  locate  on- 
ly straight  BCD  switches.  A 
couple  of  7405  hex  invert- 
ers were  used  to  generate 
the  complements  of  the 
selected  numbers. 

The  power  supply  as 
shown  in  Fig.  3  is  conven- 
tional A  12.6-V,  1-A  trans- 
former was  used  because  it 
was  on  hand.  Anything  that 
will  produce  at  least  7  5  V 
at  .5  A  should  work.  1  used  a 
7805  regulator  and  mount- 
ed it  on  the  rear  of  the  cabi- 
net. Any  -h5-V  regulator 
capable   of   handling   .5  A 


could  be  used.  A  10-uF  tan* 
talum  capacitor  from  the 
output  of  the  7805  to 
ground  is  necessary  to  pre- 
vent oscillation  and  should 
be  mounted  as  close  to  the 
output  terminal  as  possible 
De-spiking  is  provided  by 
several  .01 -uF  disc  capaci- 
tors. These  are  not  shown 
on  the  schematic,  but  were 
placed  at  various  locations 
where  the  +5-V  dc  lines 
were  near  ground  buses. 
Good  TTL  design  calls  for 
one  de-spiking  capacitor 
for  every  3  ICs,  and  one  at 
every  place  the  supply  line 
enters  a  circuit  board. 

To  make  the  timer  more 
useful  for  timing  games,  for 
use  as  a  stopwatch^  and  to 
generally  improve  portabil- 


«T0  PIN  I3k  ur 


Fig.  3,  Power  supply. 


73  Magazine  •  December,  1980    49 


Interior  view  of  the  timer  showing  the  speaker  mounted  on 
the  top  of  the  cabinet  The  power  supply  components  and 
115  V  ac  connections  are  shown  on  the  left  side.  The  small 
board  at  the  right  was  added  after  the  project  had  been  de- 
signed and  the  main  circuit  board  etched.  With  better  plan- 
ning, the  2  ICs  could  have  been  mounted  on  the  main 
board. 


ity;  I  installed  3  push-button 
switches  in  a  small  box  and 
connected  them  in  parallel 
with  the  front-mounted 
start,  stop,  and  reset  but- 
tons, I  used  a  4-pin  socket 
on  the  cabinet  back  and  a 
piece  of  4*wire  cable  from 
the  junk  box. 

I  used  FND-510S  for  the 
readouts.  They  are  large 
(.5"]  and  can  be  bought  for 
$1.00  or  less.  The  510  is  a 
common-anode  device.  Al- 
most any  7-segment  LED 
could  be  used.  Common- 
cathode  devices  would  re- 
quire   7446    drivers    and 


*5VDC 
4 


7400 

T4oa 

74  04 
7405 
3S& 


T 


Fig.  4.  Supply  connections. 


ground  connections  instead 
of  +5  V  dc. 

All  parts  were  readily 
available  at  local  Radio 
Shack  stores  and  from  firms 
advertising  in  73.  There  is 
considerable  variation  of 
prices,  so  it  pays  to  do  some 
comparison  shopping. 

I  used  circuit  board  con- 
struction. Perfboard  or 
wire-wrap  probably  would 
have  worked,  but  I  wanted 
the  neater  appearance  of 
circuit  boards.  \  ended  up 
with  4  boards.  The  FND- 
510s,  the  hours/minutes, 
and  the  minutes/seconds 
LEDs  were  on  one.  Because 
of  the  many  interconnec- 
tions with  other  ICs,  it 
seemed  simpler  to  mount 
the  7485s  and  7405s  on  a 
separate  board.  After  the 
main  board  was  etched,  I 
made  a  design  change 
which  required  the  addition 
of  the  7404  hex  inverter  and 
different  connections  to 
the  7400  NAND  gate.  A  sep- 
arate small  board  was 
made  for  those  two  ICs. 
They  could  have  been  in- 
cluded on  the  main  board 
with  proper  planning.  The 
7805  regulator,  alarm  vol- 
ume  control,    alarm    dura- 


Parts  List 

Diodes 

2^H914or1N4146 

3  1 N4CI01 
Capacitors 

6  .01  ^uF  ceraTTilc  disc 
1  10-uF  tantalum 

1  lO^yF  16-V  electrolytic 
1  22-uF  16-V  electrolytic 
1  2200^uF  le-V  electrolytic 
Integrated  Circuits 
1U1—SN7404 
1  U2— SN7400 
3U3.U5,U10— SN7492 
4U4,U6,U9,U11— SN7490 
1  U7— SN7402 

1  Ue-NE556 
3U12,U13.U14— SN7447 
3  U15,U16,U17— SN7485 

2  U18,U19--SN7405 

1  U20— 7805  regulator 
LEDs 
3-2"  discrete  LEDs 

3  FND'510  displays 
Resistors  (all  V*  Watt) 

7  330  Ohm 
23  470  Ohm 

3  2.2k  Ohm 

1  em  Ohm 

1  10k  Ohm 
1  1k  linear  pot 
1  50k  linear  pot 

1  100k  PC-board  pot 
Sockets 

2  ac  sockets  {Radio  Shack  270'&42) 
13  14-pin  IG  sockets 

616>pin  IC  sockets 
Switches 

3  NO  push-buttons  (S  1,82,83) 
1  SPST  miniature  toggle  (S4) 
1  SPOT  miniatyr©  toggle  (S5) 
1  DPST  miniature  toggle  (S6) 
1  SPST  standard  toggle  (310) 

3  'BCD  thumbwheel  switches  (S7.S8.S9) 
Other 

Cabinet  (Radio  Shack  270-269) 

Relay— SPDT,  6-V  coil  (Calectro  01-066) 

Speaker— S-Ohm,  2-inch 

Transfofmer— 12.6'V  c-tp  1  A 

Transistor— 2N2222A 

*Thumbwheel  switches  are  available  from 
Jameco.  This  installation  required: 
3  SR21  BCD  switches 
1  SRBB  blank  body 
1  pr,  SREP  end  plates 


tion  pot,  115-V  ac  sockets, 
and  the  remote-control 
socket  were  all  mounted  on 
the  rear  of  the  cabinet.  All 
other  components  were 
mounted  on  the  main  cir- 
cuit board  except  the  front- 
mounted  switches,  There  fs 
nothing  especially  critical 
about  parts  placement,  al- 
though a  little  care  and 
planning  are  needed  to  re- 
duce the  need  for  jumpers. 
Supply  connections   are 


not  shown  on  the  schemat- 
Jc,  Fig.  2.  Ground  and  +5'\/ 
dc  connections  must  be 
provided  to  all  ICs,  as 
shown  in  Fig.  4. 

This  project  has  been  a 
lot  of  fun.  In  it,  as  my  first 
attempt  to  design  a  project^ 
or  at  least  to  make  major 
modifications  to  others' 
projects,  1  have  learned  a 
great  deal  about  TTL.  And, 
the  completed  timer  has 
even  proven  useful!  I  have 


§0     73  Magaitne  •  December,  1980 


actually  used  it  as  an  ID  re- 
minder when  rag  chewing 
on  15  meters,  My  family  en- 
joys a  variety  of  games 
which  have  time  limits  vary- 
ing from  a  few  seconds  to 
several  minutes.  The  timer 
works  well  for  them.  One 
son  is  supposed  to  practice 
on  the  organ  for  30  minutes 
Sometimes  he  has  to  inter- 
rupt that  practice  for  more 
important  business  such  as 
petting  the  dog,  going  to 
the  bathroom,  etc.  Now  the 
rule  is  that  he  has  to  set  the 
timer  for  30  minutes,  stop  it 
whenever  one  of  those  di- 
versions occurs,  restart  it 
when  returning  to  the  or- 
gan, and  continue  until  30 
minutes  of  actual  practice 
have  been  completed. 

If  you  build  this  timer, 
you  will  no  doubt  want  to 
make  changes.  Some  varia- 
tions have  already  occurred 
to  me.  I  have  already  men- 
tioned the  use  of  a  7408  for 
U2.  The  timer  limit  could 
easily   be   extended    to  99 


minutes  or  99  hours.  The 
counter/driver/comparator 
chain  could  easily  be  ex- 
panded by  adding  another 
7490,  7485,  7447,  readout, 
and  thumbwheel  switch. 
The  timer  could  be  made  to 
display  tenths  of  seconds 
by  feeding  the  counters 
from  the  output  of  U3  No 
doubt  there  are  also  more 
efficient  or  effective  ways 
to  accomplish  some  of  the 
same  functions.  I  wilt  be  in- 
terested  in  hearing  about 
your  results. 

Incidentally,  etched  and 
drilled  circuit  boards  and 
parts  kits  are  not  available. 
You  are  on  your  own^  You 
will  probably  want  to  make 
modifications  to  suit  your 
own  needs.  Anyway,  getting 
there  is  at  least  half  the  fun. 

My  thanks  to  my  col- 
league, )oe  Woe  If  el,  for  the 
photography,  and  to  those 
mentioned  in  the  opening 
paragraphs  who  got  me  into 
this,  ■ 


NOW,  ADJUST  YOUR 

D104  WITH  ONE 
FINGER ! 

The  Fingertip  Volume  Control  makes  rl  simple    without 
screwdrivers,  nail  fites  or  special  tools. 

NO  DRILLING!  NO  SOLDERING f  NO  CUTTrNG* 

Remove  the  stock  bottom  plate,  screw  on  the 
F*rvgertip  Volume  Control  adjust  wrth  one  finger,  and 
talk.  Its  thai  simple! 

THE  OU  ALfTY  UNIT! 

Rugged  black  Cycolac  wrth  atummum  look  dial  ^ 
tjom  dwrafade  ar*d  atlractive.  No- scratch  rubtier  feet 
protect  line  furniture 

FTTS  THEM  ALL! 

The  Fingertip  Volume  Conttol  fits  ail  TUG8, 
TUGS.  a/Kt  TVF9  D104  microphones, 
including  ihe  Qoklen  Eagle.  Silver  Eagle, 
and  Black  foot  models  Ciomplete 
instr  uctM^ns  and  hard w  a  re  rnctuded .       gm^ 


SATISFACTtON  OU ARAHTEEDf 


II 

I 
I 
I 
I 
I 
I 
I 


URBAN  ENGINEERING,  INC, 
PO.  Box  571052 
Miami.  Florida  33157 


*^387 


Vtofune  Controiis)  al  ST  95  pkjs  SO  cenis 


posta^  WKt  hoAd^ing  «aeh  {Fk)r«ia  fesidefils  add  4»w  tax)  I  iindefstafid  tf^at  if  I  am  r^ 
completely  salisfvedlcayi  r^um  Itie  tvtitfsi  wtthin  ten  days  lof  a  fuif  refind. 


Najne  (please  prml) 
Addre^  


CityrStst^/Ztp  ^ 

□  My  check  »s  enclosed,  please  ship  within  14  days 
Q  i  have  enclosed  a  money  order  lor  tmmeciate  shipping 

□  C h  a rge  my  cf edi I  car d :  □  Visa    □  M aster  C  h arge 
CardNo. Exp  Oale  ^ Sig     


I 
I 
I 
I 


A  VERY  liAPORTANT! 

ANNOUNCEMENT  FROM  THE 


WORLD'S  LARGEST  SPECIALISTS  IN  THE  DESIGNING,  DEVELOPING 
AND  MANUFACTURING  OF  "NO  COIL,  NO  TRAP"  ANTENNA  SYSTEMS, 


NO  TRAPS.     "^^ 

NO  CAPACITORS. 
NO  COILS,  NO  STUBS 


mO-JDHD) 


MDR^emgO 


CNdE  to  ScbIu'I 

MODEL 


EXCLUSIVE  66    FOOT,75-10  METER   DIPOLES 


May  be  installed  as  invf  rl^  vee  with 
nej^lilCil'i?  t'fft?t'l  ^*ti  j>i*rfc>rmance. 
Fabricated    from    hii^hsir^t^ngtli    40S'i 
Clipper  weld    wirt*   -   <*ver   5(MI   pi)und±) 
breaking  strength, 
StainleHii  si  eel  hardware. 
CDinpUaely  iiHseinl>k»d  and  pre-tuned. 
No  rutting  **r  rneanuritig  necesiBary. 
1-year  limited  warranty. 
I'atenti'd   lini*ar  pha.st*  Ei lading  prin- 
ciple eUminateti  tittfi  lor  trapse,  limdiri^ 
eoUs  (ir  stuhs, 

Mor  Gain 

2200  T  Sguth  4th  Street 

P.O.  Sox  329  T 

Leavenwortti.  Kansas  6604S 

(913)  682-3142 

Monday  -  Friday:  9AM-5PM  CST 


En^neering  design  and  many  fart  ur 

ing  is  barked  by  our  mure  than   15 

years  experience* 

Professirmal  grade  design  -  Amateur 

models  are  identical  to  thosje  we  pro- 

duce    fur    commercial   indu£»trial 

systems, 

x\(>   antenna    tuner   rei|uired   far  op^ 

eraiiun  within  slatt^  specifications. 

He- tuneable  by  the  user  to  accomodate 

1^1  te  proxitaity  erictti, 

1H>  A  models  have  female  ct tax  con- 
nector. Other  models  have  lugs  at 
center  iasulator. 


BAND 
(Meters) 

40/20  36 

40/20  36 

?5/40/20M5/tO  66 

75/40;20/15/10  66 

75/40/20/ 15/ 10  66 


40  20  m 

40  20  HD/A 

75-10  HD 

75^10  HD/A 

75-10  HDfSPj 

7510HDiSPjA    75/40/20/15/10    66 


7520  HD  75/40/20  66 

75-20  HD/A  75/40/20  66 

75-20  HDiSP)  75/40/20  66 

75-20  HO(SP>A  75/40/20  66 

75  40  HD  75/40  66 

75-40  HD/A  75/40  66 

75  40  HO(SPl  75/40  66 

75-40  HOiSPjA  75/40  66 

flO-IOHD  80/40; 20/ 15/ 10  69 

80  10  HD/A  60/40/20/ 15/ 10  69 

eOlOHDlNTi  aO/40/20/15/tO  69 

60TOHOtNT)A  80/40/20/15/10  69 

80-40  HD  80/40/15  69 

M  40  HD/A  80.' 40  15  69 

80-40  HO(NT>  80.40n5  69 

8040H0(NT|A  80/40/15  ^ 

Please  mdude  S3.Q0  (or  siiippmg  and 

insurance 

NT  series  are  models  spectficaily  op- 
tiiriffed  for  novtce  band  opertors 


LENGfH  PRICE 

(ieet) 

36     S  69  2b 

36     S  75  50 

$112.25 

sua  50 

S71225 
311850 
S  95  50 
S101  75 

$101  75 
S  81  00 

S  8725 
S  81  00 
S  87  - 
SH725 
S12350 
S1 17  26 
S123-50 
S  85  75 
S  92  00 
S  8575 
S  92  00 


Please  write  for  fully  descriptive  5  page  brochure.  Contact  youf  favorite  dealer  or  order  direcf  Irorn  Mor-Gam 


^  Reader  Service— sec  page  226 


73  Magazine  •  [December,  1980    51 


Dr.  Ralph  E.  Jaggart  WBBDQT 
602  South  ieffenon 
Maion  Ml  43854 


Direct  Printing  FAX 

part  II:  constructing  the  facsimile  recorder 


In  part  I!  of  this  three-part 
article,  I  will  cover  con- 
struction  of  the  facsimile 
recorder.  Construction  is 
probably  the  most  critical 
part  of  the  project  as  con- 
siderable mechanical  tin- 
kering is  involved  and  the 
various  parts  must  function 
smoothfy  in  relation  to  one 
another  if  quality  results 
are  to  be  obtained. 

Recorder  Mechanics 

The  easiest  approach  is 
to  use  the  FX-2E  minikit 
available  from  METSAT 
Products,  Box  142,  Mason 
Ml  48854.  This  kit  contains 
drilled  and  plated  circuit 
boards  for  the  electronics 
circuits  and  a  complete  set 
of  parts,  most  fully  assem- 
bled, for  the  fax  mechanics. 
The  mechanical  assembly, 
illustrated  in  Fig.  1,  is  made 
up  of  a  series  of  parts  ma- 
chined out  of  brass,  alumi- 
num, and  stainless  steel  and 
it  is  built  like  a  battleship.  It 
is  quite  heavy  and  massive 
and  provides  the  rigidity 
and  precision  required  for  a 
smoothly  operating  system. 
The  parts  are  drilled  and 
tapped  to  permit  assembly 
and  disassembly  with  ma- 
chine screws,  and  the  kit  in- 
cludes all  of  the  mechanics 
components  including  the 
motors.  About  15  minutes 


of  additional  assembly 
work  is  required  to  get  the 
assembly  ready  for  opera- 
tion. The  cost  for  this  pack- 
age is  1500  plus  shipping. 
This  is  more  than  you  will 
pay  for  the  home-built  al- 
ternative but  does  elimin- 
ate virtually  all  of  the  work 
associated  with  the  me- 
chanical part  of  the  project, 
and  you  also  get  circuit 
boards  for  the  electronics. 

The  second  approach  is 
to  build  the  mechanics 
yourself.  To  this  end,  I  have 
documented  a  modified 
(and  improved)  version  of 
the  fax  mechanics  de- 
scribed in  the  first  edition 
of  the  Weather  Sateliite 
Handbook,  This  assembly 
will  do  an  excellent  job,  but 
you  will  have  to  build  it  and 
do  considerable  fine-tuning 
to  get  it  operating  property. 
Once  it  is  set  up,  it  should 
require  very  little  ongoing 
maintenance. 

The  Drum.  The  drum  (Fig. 
2)  is  fabricated  from  a  plas- 
tic rolling  pin  — a  "Pastry 
Pin"  manufactured  by  the 
Housewares  Division  of  the 
Foley  Manufacturing  Com- 
pany of  Minneapolis.  This 
item  is  sold  in  housewares 
departments  and  discount 
stores  across  the  country 
and   costs    between   $1.60 


and  $2,00  depending  upon 
the  source.  The  drum  is  just 
over  2  inches  [5  cm)  in 
diameter  and  is  perfect  for 
this  application.  Other  ma- 
terials  may  be  used  for  the 
drum,  but  you  should  stick 
close  to  this  figure  for  the 
diameter  to  avoid  distor- 
tion of  the  image  aspect  ra- 
tio. 

The    plastic    handles   of 

the  rolling  pin  are  twisted 
off  and  the  shaft  removed. 
A  fine  saw  is  used  to  cut  the 
drum  down  to  a  length  of  8 
inches.  True  the  cut  end  by 
using  a  fine  file  or  sand- 
paper, and  insert  the  end 
piece  removed  from  the 
short  length  that  was  cut 
from  the  drum.  The  steel 
shaft  should  be  cut  down  to 
11 .25  inches  (save  the  piece 
you  cut  off  as  we  will  use  it 
for  the  stylus),  Deburr  the 
ends  with  a  fine  file,  and 
use  steel  wool  or  emery 
cloth  to  remove  any  corro- 
sion from  the  steel  shaft 
Use  a  cyanoacrylate  adhe- 
sive (Super  Glue"^^, 
Eastman  910^^,  or  other 
brands)  to  cement  the  shaft 
into  place  as  indicated  in 
Fig.  2. 

Now  comes  the  part 
which  is  harder  to  describe 
than  it  is  to  do.  The  paper 
we    will    use    is    a    front- 


grounding  paper.  This 
means  that  the  ground 
return  must  be  provided 
from    the    paper   surface. 

This  is  accomplished  via  an 
aluminum  foii  strip  at- 
tached to  the  drum  surface 
and  connected  to  the  drum 
shaft  for  grounding  Drill  a 
#2  pilot  hole  at  the  right  end 
of  the  drum  and  place  the 
small  end  of  the  angled 
piece  of  foil  over  this  hole. 
Use  a  small  sheet-metal 
screw  to  attach  a  small 
solder  lug  so  that  it  is  in 
contact  with  the  foil  strip. 
The  7-inch  length  of  foil  is 
folded  in  half  lengthwise 
along  the  dotted  line  and 
laid  along  the  precise 
center  line  of  the  drum  so 
that  the  right  end  of  the 
strip  is  in  contact  with  the 
piece  of  foil  already  in 
place.  A  long  piece  of  trans- 
parent tape  is  then  used  to 
attach  the  lower  side  of  the 
folded  tape  to  the  drum  sur- 
face. The  upper  folded  side 
must  be  free  so  that  the 
paper  can  be  inserted  under 
it  when  it  is  fastened  to  the 
drum.  The  transparent  tape 
should  extend  all  the  way  to 
the  back  of  the  fold  so  that 
the  entire  lower  half  of  the 
foil  strip  is  covered,  and 
should  be  wide  enough  to 
extend  past  the  foil  on  three 
sides   as    indicated   in  the 


73  Magazine  •  December,  1980 


figure.  Additional  tape  then 
can  be  used  to  cover  the  ex- 
posed parts  of  the  angled 
piece  of  foil  so  that  it  will 
not  pull  loose. 

Next,  break  two  brass  in- 
serts out  of  standard  plastic 
panel  knobs.  Set  one  of 
these  aside  for  styius  con- 
struction and  slide  the 
other  over  the  right  end  of 
the  drum  shaft,  using  its  set 
screw  to  secure  it  up 
against  the  right  end  of  the 
drum.  Prior  to  this  step, 
however,  you  should  solder 
a  short  length  of  hookup 
wire  to  the  outside  of  the 
brass  insert.  When  the  in- 
sert is  locked  in  place,  cut 
and  strip  the  wire  and 
solder  it  to  the  small  solder 
lug  mounted  previously.  Do 
this  operation  quickly  to 
avoid  melting  the  plastic  of 
the  drum  A  small  magnet 
should  be  cemented  to  the 
drum  as  indicated  in  the  fig- 
ure, This  completes  the 
drum  assembly.  It  should 
be  set  aside  carefully  to 
avoid  spoiling  your  handi- 
work. 

Motors.  The  drum  and 
traverse  motors  which  are 
recommended  are  manu- 
factured  by  the  Hurst 
Manufacturing  Company  of 
Princeton  IN.  Other  syn- 
chronous motors  of  iden- 
tical speed  and  similar 
power  rating  or  torque  may 
be  substituted.  Motors  of 
other  speeds  might  also  be 
usable  if  suitable  gearing  is 
provided  to  produce  the 
proper  speed  at  the  output 
shaft  of  the  gearing  assem* 
biy. 

The  drum  motor  is  a 
240-rpm  type-GA  motor, 
rated  at  10  W,  with 
600-inch-oz  torque  at  1 
rpm.  This  speed  is  not  a  nor- 
mally stocked  option,  but 
can  be  obtained  on  special 
order  with  a  lead  time  of  4-6 
weeks.  The  traverse  motor 
selection  is  based  on  the 
class  of  service  for  which 
the  recorder  is  intended. 
For  GOES  WEFAX,  yoy 
should  obtain  a  40-rpm 
type-CA  motor.  This  selec- 
tion also  will  work  well  for 


Fig.  T.  A  photograph  showing  the  METSA  T  version  of  the  facsimile  mechanics.  The  home- 
built  version  described  here  operates  on  the  same  principles,  but  some  features  have 
been  changed  to  facilitate  home  construction.  In  the  METSAT  version,  the  base  and 
backptate  are  1/2''  atuminum  v^ith  1/8^'  aluminum  side  pistes.  The  motors  are  to  the  left 
and  the  siytus  carriage  and  the  stylus  itself  are  visible.  In  the  illustrated  version,  the 
machined  brass  carriage  base  plate  rides  on  two  brass  rails.  The  drum  shows  the  foil 
grounding  strip,  magnet,  and  grounding  wire  and  shaft  collar.  The  magnetic  reed  switch 
that  helps  control  Wf  MX  phasing  is  shown  on  the  right  end  plate. 


METEOR  display.  TIROS  N 
display  will  require  a 
20-rpm  type-CA  motor. 
Both  the  40-  and  20-rpm 
motors  are  available  as 
stock  items.  It  should  be 
noted  that  all  of  the  motor 
speed  ratings  given  are  ref* 
erenced  to  60-Hz  ac  drive. 
In  50-Hz  countries,  you 
should  obtain  motors  de- 
signed  to  operate  from 
50-Hz  mains.  Do  not  do  this 
for  the  drum  motor  as  the 
sync  system  is  designed  to 
provide  60-Hz  drive,  and  if 
you  use  a  240-rpm  motor 
designed  for  50  Hz,  the 
drum  will  be  too  fast.  The 
motor  wiring  should  be  fol- 
lowed carefully,  or  the  mo- 
tors may  not  turn  in  the 
proper  direction  —  some- 
thing that  will  lead  to  some 
rather  unusual  pictures. 

Mechanics  Assembly. 
Fig.  3  shows  some  general 
views  of  the  relationship  of 
parts  for  the  home-built  ver- 
sion of  the  fax  mechanics. 
Precise  measurements  are 


mimmminmrnmiiimm^ 


.  <■«  r..  ?.t    ^ 


Ors*^ 


■0T5 


1&AT3 


Tig.  2.  (1]  General  drum  configuration.  (A)  1/4^'  steel  shaft. 
(B)  Drum.  (C)  Small  solder  tug.  [D]  Piece  of  insulated 
hookup  wire  soldered  to  C  and  E.  (E)  Brass  insert  from  a 
1/4'"  control  knob  secured  to  the  drum  shaft  with  its  set- 
screw.  (2)  Layout  of  aluminum  foil  strips  [crosshatched] 
and  transparent  tape  (stippled)  on  the  drum.  (F)  is  the  small 
magnet  attached  to  the  drum  surface  with  double-sided 
adhesive  foam  tape.  (3)  Dimensions  of  aluminum  foil 
strips  (see  text  for  assemblyl 


73  Magazme  •  December,  1960     53 


BA!&E 


riVlt  V(E« 


TOP  W'/f  I 


F^  3  The  facsimile  recorder  mechanical  assembly.  A-^Drum  motor;  B^  traverse  motor;  C— motor  mounttrig  plate 
ar}gle  bracket;  D  — motor  mour^ting  plate;  E  — rubber  tubirig  shaft  couplmg;  F^drhe-rod  support  plate  angle  bracket; 
C  — drive-rod  support  plate;  H  —  3/8''  panel  bushing;  I  --drum  support  bracket; }  —  carriage  track  bracket;  K— glass-plate 
track  surface;  L^  1/4-20  threaded  drive  rod;  M^drum  assembly;  N^ stylus-carriage  base;  O  — stylus  support:  P^  car- 
riage-drive washer,  and  Q-- 1/4-20  carriage-drive  nut 


11 


Fig.  4.  Stylus  holder  details.  (A)  3-1/4'  piece  of  1/4'*  steel 
rod  stock  (left  over  after  the  drum  shaft  has  been  cut  to 
size].  (B)  3/4"  piece  of  3/B''  o.d.  plastic  tube  stock.  (C)  1/2" 
piece  of  7/76"  tube  stock  (stylus  holderl  (D)  length  of 
hookup  wire  soldered  to  one  end  of  (CI  (E)  Wire  stylus  in- 
serted into  (Q. 


of  little  use  since  the  details 
of  layout  will  depend  upon 
the  locally  available  mate- 
rials. I  will,  however,  pro- 
vide some  general  notes, 
trusting  in  your  ability  to 
improvise. 

The  base  of  the  unit  is 
best  made  with  a  piece  of 
3/4"  plywood.  The  surface 
should  be  covered  with  for- 
mica, masonite,  or  some 
other  smooth  material  The 
recorder  will  produce  some 
fine  black  ash  that  ac* 
cumulates  after  a  time  and 
needs  to  be  wiped  off  the 
surface.  This  is  quite  dif- 
ffcult  if  the  natural  rough 
wood  porous  surface  is  re- 
tained. The  recorder  me- 
chanics utilize  standard 
3/8''  panel  bushings  for  1/4" 
control  shafts  as  bearings 
for  the  drum  and  drive  rod. 
The  drum  is  supported  by 
two  such  bushings  mounted 
at  the  top  of  the  upright 


section  of  two  standard 
steel  or  brass  right-angle 
brackets  available  from 
local  hardware  stores.  The 
brackets  should  have  the 
standard  screw  holes  en- 
larged to  3/8"  to  acconn* 
mod  ate  the  bushings. 

Mount  the  right  bracket 
to  the  base  with  wood 
screws  and  orient  the  left 
bracket  so  that  the  drum 
will  turn  freely  when  the 
bracket  is  screwed  in  place. 
Occasionally,  these  brack- 
ets are  not  completely  true 
so  that  some  bending  with  a 
pair  of  heavy  pliers  may  be 
required  after  mounting  to 
true  up  the  bushings  so  that 
the  drum  wil!  turn  freely. 
The  drum  motor  is  mounted 
to  a  plate  of  C-10  fiberglass 
board  stock,  1/8"  aluminum 
sheet  stock,  or  other  rigid 
materiaK  This  mounting 
plate  is  secured  to  the  base 
with  a  piece  of  1/2"  alumi- 


num angle  stock  cut  to  the 
width  of  the  motor  mount- 
ing plate.  The  hole  for  the 
motor  shaft  bushing  is 
drilled  so  that  the  motor 
shaft  will  line  up  precisely 
with  the  drum  shaft  when 
the  plate/bracket  assembly 
is  screwed  to  the  plywood 
base. 

Once  the  shaft  bushing 
hole  has  been  drilled  cor- 
rectly, you  can  mark  and 
drill  the  holes  for  the  motor 
mounting  lugs,  Final  posi- 
tioning and  securing  of  the 
mounting  plate  to  the  base 
is  done  while  checking  the 
alignment  of  the  motor  and 
drum  shafts.  The  motor  and 
drum  are  coupled  with  a 
piece  of  thick-watled  tubing 
of  the  type  used  for  vacu- 
um tines  in  laboratories  or 
automobile  engines. 

The  stylus  carriage  is 
assembled  from  hardwood. 
The  base  piece  should  be 
about  3  inches  square,  and 
the  vertical  upright  should 
be  cut  so  that  it  is  at  or 
slightly  above  the  center- 
line  of  the  drum,  A  long 
piece  of  aluminum  angle 
bracket  is  laid  out  parallel 
to  and  about  an  inch  out 
from  the  drum  face  to  de- 
fine one  edge  of  the  car- 
riage  track.  The  positioning 
of  the  other  edge  is  based 
on  the  width  of  your  car- 
riage base  piece  The  sec- 
ond   rail    should    be    posi- 


tioned to  provide  a  smooth 

sliding  fit  for  the  carriage 
base  piece,  it  should  be 
tight  enough  to  eliminate 
any  shifting  of  the  base  but 
no  so  tight  that  it  binds. 
Once  the  second  track  rail 
has  been  mounted,  you 
should  measure  the  track 
width  (between  the  rails) 
and  have  a  piece  of  window 
glass  cut  to  fit  between  the 
rails.  It  should  beepoxied  in 
place. 

The  next  job  is  to  prepare 
the  support  plates  for  the 
1/4-20  threaded  drive  rod. 
The  rod  must  run  down  the 
center  of  the  track  at  a 
height  that  will  place  it 
about  1/2"  above  the  top 
surface  of  the  carriage 
base.  The  rod  is  supported 
by  two  3/8"  bushings  in 
small  plates  of  C-10  board 
stock  or  metal  secured  to 
the  base  with  strips  of 
aluminum  angle  stock  Drill 
the  plates  so  that  the  3/8" 
holes  are  at  exactly  the 
same  height.  Install  the 
bushings  and  secure  the 
plates  to  the  base  so  that 
the  rod  runs  down  the  cen- 
ter  of  the  track. 

The  traverse  motor 
mounting  arrangements  are 
essentially  identical  to 
those  of  the  drum  motor, 
with  alignment  and  mount- 
ing adjusted  to  keep  the 
traverse  drive  shaft  in  align- 
ment  with    the    threaded 


S4    73  Magazin§  •  December,  1980 


drive  rod. 

A  3/8"  hole  should  be 
drilled  in  the  vertical 
member  of  the  carriage 
assembly  so  that  the  car- 
riage can  be  moved  along 
the  length  of  the  track 
without  coming  in  contact 
with  the  drive  rod.  Remove 
the  carriage  and  paint  it 
with  several  coats  of  epoxy 
paint  or  other  oil-resistant 
finish.  While  the  carriage  is 
drying,  take  a  1/4-20  nut  and 
drill  a  small  hole  part  way 
through  one  of  the  flat 
faces  on  the  edge  of  the 
nuL  Solder  a  3/4"  wire  brad 
or  nail  into  this  hole. 


A  small  quantity  of 
talcum  powder  shou[d  be 
sprinkled  onto  the  track  to 
serve  as  a  dry  lubricant. 
Place  the  carriage  at  the 
center  of  the  track  and 
thread  the  drive  rod 
through  the  left  support 
bushing,  continuing  to  ex* 
tend  the  rod  until  the  right 
end  protrudes  through  the 
hole  drilled  in  the  vertical 
carriage  member  Slide  the 
1/2"  flat  washer  over  the  ex* 
posed  end  of  the  drive  rod 
and  thread  the  prepared 
nut  over  the  end  of  the  rod. 
Run  the  nut  down  the  rod 
(to  the  left)  while  extending 
the  rod  until  it  passes 
through  the  support  bush- 
ing on  the  right  end  of  the 
track.  Couple  the  right  end 
of  the  threaded  drive  rod  to 
the  traverse  motor  shaft  us- 
ing another  piece  of  thick- 
walled  rubber  tubing. 

Rotate  the  drive  nut  until 
the  brad  is  horizontal,  and 
move  the  carriage  up 
against  the  drive  nut/wash- 
er assembly.  Note  that  if 
the  drive  rod  is  rotated  in 
either  direction,  the  nut  will 
rotate  until  the  brad  comes 
into  contact  with  the  car- 
riage base.  At  this  point  the 
nut  can  no  (onger  rotate 
and  must  move  along  the 
shaft.  If  the  shaft  is  rotated 
in  a  counterclockwise  di- 
rection (viewed  from  the 
front  of  the  traverse  motor), 
the  nut  will  move  away 
from  the  carriage  and  to- 
ward   the    motor.    This    is 


Pin 

Function 

1 

Ground 

2 

Phase  sensor  reed  switch  (S203) 

3 

Stylus 

4 

M2  black  lead  (both) 

5 

Ml  while  lead 

6 

Ml  black  lead 

7 

M2  red  lead 

8 

M2  white  lead 

Table  1. 

what  will  occur  when  you 
are  resetting  the  recorder.  If 
the  shaft  is  rotated  in  a 
clockwise  direction,  the  nut 
will  move  away  from  the 
motor,  pushing  the  carriage 
ahead  of  it.  Misalignment 
or  wobble  in  the  shaft  will 
cause  the  nut  to  slide 
around  in  contact  with  the 
washer  but  will  not  result  in 
axial  movements  of  the  car- 
riage; the  only  motion 
transferred  to  the  carriage 
is  a  smooth  push  down  the 
length  of  the  carriage  track 
This  particular  drive  system 
is  much  superior  to  systems 
where  the  nut  is  directly  at- 
tached to  the  carriage  as- 
sembly. 

The  final  step  in  the 
assembly  of  the  main  me- 
chanics  package  is  to  fabri- 
cate a  small  aluminum 
bracket  that  will  attach  to 
the  right  drum-mounting 
bracket  and  hold  the  mag- 
netic reed  switch  above  the 


C 
' ' 

r 

fl 

E' 

'1        1 

1  0  ii 

1           1 

1 1         ; 

"1 

A 

r 

o 

fig.  S.  Stylos  support  details.  (A)  7  "  farass  angle  bracket,  [B] 
1  '^  piece  of  1/4"*  (o.d)  brass  tubing  soldered  to  the  top  of 
the  vertical  leg  of  the  angle  bracket.  (C)  7-J/4"  piece  of 
3/16"  (oM.)  brass  tube  soldered  at  one  end  to  the  side  of 
the  brass  insert  from  a  1/4"  control  knob  (Dl  (E)  3/16 '(id J 
wheel  collar.  (F)  5/16'^  piece  of  1/4"  fo.d.)  brass  tube  stock 
soldered  to  (C)  so  that  the  latter  extends  beyond  (F)  on  the 
right  side. 


right  end  of  the  drum.  Wire 
leads  should  be  soldered  to 
the  switch  terminals  and  a 
covering  of  electrical  tape 
placed  over  the  entire 
switch  assembly.  The  alu- 
minum support  bracket  and 
the  attachment  of  the 
switch  assembly  to  this 
bracket  should  be  adjusted 
so  that  the  small  magnet  on 
the  drum  will  close  the 
switch  once  during  each 
drum  revolution.  This  can 
be  checked  with  an  ohm- 
meter  connected  to  the 
switch  leads,  Although  alu- 
minum is  specified  for  the 
switch  mounting  assembly, 
almost    any    non-ferrous 


metal  can  be  used.  Steel 
should  be  avoided  as  it  will 
gradually  become  magne- 
tized in  the  field  of  the 
drum  magnet,  exerting  a 
pull  on  the  switch  elements 
that  will  gradually  make 
the  switch  less  sensitive 

Sty/u5  Assennbly.  The  de- 
tails of  the  stylus  assembly 
are  shown  in  Figs,  4  and  5. 
The  stylus  holder  is  made 
up  from  the  scrap  piece  of 
1/4"  steel  rod  cut  from  the 
drum  shaft.  To  insulate  the 
stylus  from  the  support 
arm,  a  small  piece  of  plastic 
tubing  is  cemented  to  the 
end  of  the  steel  rod,  using 
cyanoacrylate  glue.  A  small 


Fig.  6.  Stylus  pivot  and  stylus  arnn  assemblies.   The  stylus  support  bracket  and  pivot 
assembly  are  shown  to  the  left,  while  the  stylus  arm  is  on  the  right 


73  Magazine  •  December.  1980     55 


piece  of  1/16"  brass  tubing 
(this  and  other  sizes  of  brass 
tubing  are  dvailable  in  your 
local  hobby  shop)  serves  to 
hold  the  small  steel  stylus 
wire  A  piece  of  lightweight 
hookup  wfre  is  soldered  to 
one  end  of  the  brass  tube 
which  then  is  mounted  in  a 
hole  drilled  in  the  plastic 
end  piece  and  secured  with 
cyanoacrytate  cement. 

For  the  stylus  wire,  you 
wilt  need  one  of  the  small 
wire  brushes  designed  to 
operate  in  an  electric  drill. 
{We  will  get  to  that  during 
final  checkout)  The  stylus 
arm  is  supported  by  a  brass 
pivot/bearing  assembly 
formed  of  small  pieces  of 
brass  tubing  The  bearing 
assembly  is  soldered  to  a 
small  brass  angle  bracket 
screwed  to  the  vertical  sup- 
port of  the  carriage  assem- 
bly. The  precise  size  of  the 
various  pieces  of  tubing 
used  for  the  bearing  assem- 
bly  is  unimportant  as  long 
as  the  pieces  nest  smoothly. 


The  second  brass  knob 
insert,  which  you  had  set 
aside  earlier,  is  soldered  to 
the  long  piece  of  tubing  IQ 
which  serves  as  the  axle  of 
the  support  structure  for 
the  stylus  arm.  The  bearing 
for  the  support  of  this  axle 
(B)  is  soldered  at  the  top  of 
the  vertical  extension  of  the 
brass  angle  bracket,  An  alu- 
minum "wheel  collar/' 
available  from  the  same 
hobby  shop  where  you  get 
the  tubing,  serves  as  a  stop 
at  the  brass  insert  end  of  the 
shaft,  while  a  small  piece  of 
tubing  (F)  is  slipped  over  the 
shaft  and  soldered  at  the 
outside  end  to  provide  the 
second  stop.  The  tubing 
pieces  should  be  deburred 
and  the  ends  filed  true  prior 
to  assembly.  When  com- 
pleted, the  inserted  knob 
should  rotate  very  freely 
but  with  no  excess  play  in 
any  other  axis.  Fig.  6  shows 
the  assembled  stylus  parts 
to  give  you  some  idea  how 
they  look  when  assembled. 


The  stylus  pivot  assem- 
bly is  mounted  to  the  car- 
riage upright  using  wood 
screws.  It  should  be  ori- 
ented with  the  bearing  tube 
facing  the  drum.  The  free 
end  of  the  stylus  arm  is  in- 
serted in  the  brass  knob  in- 
sert, and  the  support  arm  is 
oriented  so  that  the  pro- 
truding brass  tube  is  facing 
directly  down  at  the  top 
center  of  the  drum.  The  set 
screw  of  the  insert  then  can 
be  tightened  to  secure  the 
stylus  arm.  The  small  brass 
tube  used  to  hold  the  wire 
stylus  should  now  be  rest- 
ing in  contact  with  the  top 
of  the  drum  along  the  cen- 
ter line.  The  weight  of  the 
stylus  arm  will  supply  the 
needed  stylus  pressure.  You 
should  be  able  to  lift  the 
stylus  arm,  folding  it  back 
away  from  the  drum,  and 
there  should  be  no  binding 
in  the  pivot  assembly 

The  connection  between 
the  control  electronics  and 
the  mechanics  assembly  is 


via  an  8<onductor  cable. 
The  cable  is  anchored  to 
the  base  of  the  mechanics 
assembly  and  is  equipped 
with  an  6-conductor  plug 
{P3)  that  mates  with  an 
8-conductor  socket  on  the 
rear  apron  of  the  elec- 
tronics cabinet.  The  P2  and 
P3  pin  assignments,  as  in- 
dicated in  the  schematics, 
are  shown  in  Table  1. 

Heat-shrink  tubing,  tape, 
or  other  insulating  steps 
should  be  taken  for  all  con- 
nections [including  the  Ml 
starting  capacitor,  C301)  to 
eliminate  the  possibility  of 
shorting  leads  or  creating  a 
shock  hazard. 

If  you've  managed  to  get 
the  electronics  constructed 
and  working  already,  com- 
pleting this  mechanical 
phase  should  keep  you 
busy  until  part  III  of  this  ar- 
ticle arrives.  In  part  UK 
we'll  put  the  whole  system 
together,  test  and  calibrate 
it,  and  (hopefully)  enjoy  the 
results.  ■ 


HAM-KEIY' 

RADIO  TELEGRAPH  SENDING  DEVICES 


Km^  Loiucf  rric€s 


Model  HK-3M     '^HQSC 

Add  $2.00  Shipping 
Sl  Handling. 


•  Navy  type  knob 

*  Smooth  action 


Deluxe  strain t  k«Y 

Anti-tip  bracket.  Can't  lip 

Hdavv  base.  No  need  to  attach  to  desk 

Model  AT-B  ami-tip  bracket  only,  to  convert  any  HK-3  to  HK-3M. 

Sl^O  Postpaid 
CC-3P  shielded  cabie  &  plug  for  HK-3M  SI  .50 

Add  S  .50  Shipping  &  Handling. 


Model  HK-1 


Add  $2.00  Shipping 
Sl  Handling, 

*  Dual  lever  squeeze  paddle 

*  For  use  with  all  electronic  keyers 

*  Heavy  base  with  non-slip  rubber  fe«t 

*  Paddles  reversible  for  wide  or  close 
finger  spacing 

Model  HK-2,  same  as  HK-1  but  less  base  for  incorporation  in  yout 

own  keyer.  $16.95 
Add  Si. 00  Shipping  &  Handling 

CC'IP  shielded  cable  &  plug  for  HK-I  S2.00 

Add  $  30  Shipping  8l  Handling. 


Model  HK-4     5l4Sr 


Now  $37  95 

Add  $2,00  Shipping 
Si  Handling. 


*  Combination  HK-1  &  HK-3  on  same  b9S0 

*  Straight  key  may  be  used  conventionally  or  as  a  swTtcb  to  trigger 
a  mefnory. 

CC-1/3P  Shielded  cable  with  pli^s  for  HK-4  $3.50 

Add  St. 00  Shipping  &  Handling 


Model  HK-5A  Electronic  Keyer 


Iambic  circuit  for  squeeze  keying 
Self  completing  dots  &  dashes 
Dot  &  dash  memory 
Btrilt-in  sidetone 


Add  $2.00  Shipping 
fit  Handling, 


*  Uses  Curtis  S044  keyer  chip 

*  Grid  block  or  direct  keying 

*  Speed,  volume,  tone  &  weight 

controls  on  from  panel 

*  Use  with  HK-1  or  HK^ 


*  Battery  operated  wtth  provisions  for  external  power 


master  f.hargp 

I     J 


■  *  I     M*B  HB      A     J^mi 


IF  NOT  IN  STOCK  AT  YOUR  DEALER,  ORDER  DIRECT  FROM 
P.O.  Sox  28271  The   XlAJVl-X^  Fj  JL   Co.  -^^    St.  Louis,  MO  63132 

Pbone  TOLL -FREE  1- 800-325-3651 


VfSA 


56     73  Magazine  •   December,  1960 


WHY  GET  ON  FAST  SCAN  ATV  ? 


You  can  send  broadcast  quality  video  of  home  movies,  video 
tapes,  computer  games,  the  shack,  etc.,  at  a  cost  that  is  less  than 
slowscan.    Requires  only  a  technican  class  or  higher. 

Really  aids  public  service  communications  for  parades,  RACES, 
CAP  searches,  weather  watch,  marathons,  etc. 

DX  is  about  the  same  as  2  meter  simplex  - 15  to  100  miles. 

ATV  uses  broadcast  standards.  No  special  converters  needed. 
Receive  full  color  and  sound  on  a  regular  TV  set. 


TC-1   TRANSMITTER/CONVERTER 


in 


ntvfamti 


ttwtn 


ALL  IN  ONE  BOX  READY  TO  OPERATE    S399  delivered  US. 

Plug  In  any  closed  circuit  camera,  antenna,  mic,  and  TV  set  and  you 
are  on  the  air.  Contains  the  basic  four  modules,  AC  supply,  and  T/R 
switch.     Full  color  and  sound.     Specify  xnntr  freq  and  TV  ch  2  or  3. 

GET  A  BUDDY  ON  SPECIAL 2  for  S  750  ppd 

HITACHI  HV62U  CAMERA  B  &  W S  239  ppd 

GP-4D  COLOR  CAMERA  ,  • S839  ppd 


Build  Your  Own  System  with  The  Basic  Four  Modules 


i  J- 


M 


1.  TXA5-4  ATV  EXCITER/MODULATOR ,, S  89  ppd 

This  wired  and  tested  module  h  designed  to  drive  the  Motorola  MHW-710  module 
in  the  PA5  10  watt  linear  amp.  The  crystal  in  the  100  mHz  region  keeps  harmonics 
out  of  two  meters  for  talk  back.  The  video  modulator  is  full  8  mHz  for  computer 
graphics  and  color.  Requires  13.8  vdc  reg  @  70  ma.  Tuned  with  xtal  on  439.25, 
434.0  ,  or  426.25  mHz,   Two  Freq  S  1 1 5  ppd. 


PAS  10  WATT  ATV  POWER  MODULE ,  ,  ,  S  79  ppd 

The  PA5  will  put  out  10  watts  RMS  power  on  the  sync  tips  when  driven  with  80 

mw  by  the  TXA5  exciter.  50  ohms  in  and  out,  plus  bandwidth  for  the  whole  band 
with  good  finearity  for  color  and  sound,    Requires  13.8  vdc  regulated  @  3  amps, 

3*   FMA5  AUDIO  SUBCARRIER  GENERATOR ,..., ,  .  S  29  ppd 

Puts  audio  on  with  your  camera  video  just  as  broadcast  TV  does  at  4,5  mHz.  Puts 
out  up  to  1  V  p-p  to  drive  the  TXA5  or  VM-2.  3,  or  4  modulators.  Requires  low 
Z  mic  (150  to  600  ohms),  and  +12  to  18  vdc  @  25  ma.  Works  with  any  xmtr 
with  5  mH2  video  bandwidth. 


TVC  2  ATV  DOWNCONVERTER , . S  55  ppd 

Very  sensitive  stripline  MRF901  (1.7  db  NF)  preamp  and  double  balanced  mixer 
module  digs  out  the  weak  ones  but  resists  intermods  and  overload.  Connects  be- 
tween  uhf  antenna  and  TV  set  tuned  to  channel  2  or  3.  Tunes  420  to  450  mHz. 
Requires  +12  to18  vdc  @  20  ma.  Super  sensitive  TVC-2L  with  NE64535  preamp 
(.9  db  NF)  preamp  $  79  ppd. 


TVC-4  ATV  DOWNCONVERTER  ,.,,... S  89  ppd 

This  is  a  packaged  version  of  the  TVC-2  converter  with  internal  power  supply. 
Has  BNC  input  and  F  output  connectors.  Also  available  with  the  NE64535  for 
$1 1 5  ppd.    Size  5%  x  2)4  x  7  inches. 


PACKAGE  SPECIALS 

TXA5-4,  PA5,  FMA5,  and  TVC'2 

BASIC  MODULE  PACKAGE  _  .  .   $  239  Ppd 

OPTIONS: 

2  frequency  exciter  ,,..,,,,.,,..  add  S  30 
NE 64535  low  noise  downconverter  ,add  S  30 
Packaged  TVC-4  downconverter . .  .  add  S  34 


SEND  SELF  ADDRESSED  STAMPED  ENVELOPE  FOR  COMPLETE 
CATALOG  AND  ATV  INFO-  We  have  all  your  ATV  needs:  Antennas, 
Cameras,  Repeaters,  Video  Monitors,  Preamp,  Linears,  Test  Equipment, 
and  more,  19  years  in  ATV,  Check,  Money  Order  or  Credit  Card  by 
mail.    Credit  Card  orders  call  (21  3)  447-4565 


V/SA 


P.O.  ELECTRONICS 


^>S? 


Maryann 

wBevss 


2522  PAXSON 
ARCADIA.  CA  91006 


Tom 
W60RG 


*^  ReMlef  Service— see  page  226 


73  Magazine  •  December,  1980    57 


A  600-MHz  Universal  Counter 

you'll  freq  out  over  this  one 


Function 

mgH 

Function  Input 

Frequency 

D. 

Pin  3 

Period 

D, 

Frequency  Ratio 

D, 

Time  Interval 

D* 

Unit  Counter 

D, 

Oscillator  Frequency 

D, 

Range  Input 

0.01  s/1  cycle 

D. 

Pin  14 

0.1  s/10  cycles 

D, 

1  sn  00  cycles 

D, 

10  s/ Ik  cycles 

D, 

Control  Input 

Blank  Display 

0,  and  Hoid 

Pin1 

Display  Test 

D. 

1  MHz  Select 

D, 

Externa  Oscillator 

Da 

Enable 

Table  1. 


•3V 
4 


rtsf 
f 


EXT 


C0*iT1?flL 

m 


SCE  F(&Uf?£  li 


E.  t  Bufimgton  W4VGZ 
2736  Woodbury  Dnve 
Bufiifigton  NC  2721S 

This  is  truly  a  one-chip 
counter.  The  Intersil 
ICM7216  BIPI  counter  chip 
does  it  all.  It  is  a  frequency 
counter,  period  counter, 
frequency  ratio  counter, 
tinne  Interval  counter,  or  a 
totalizing  counter  It  uses  a 
1'  or  10-MHz  timebase  and 
has  facilities  for  an  external 
tinnebase  input.  For  period 
and  time  interval,  the  10- 
MHz  timebase  gives  O.Vmi- 
crosecond    resolution.    In 


HOt-D 


EKt 

III 

* 


^ 


——Ml- 


av 


i 


OIQCt   PRIVE 

ce  WIRES) 

FiiHCT\0f4 
E6  WinESj 
RANGE 
(4  WlHE^! 


SEG.  DRIVE 
i9  WIRES) 


Fig.  h  Counter  section  part  of  main  hoard. 


the  frequency  mode,  the 
user  can  select  accumuta* 
tion  tinnes  of  0.01,  0.1,  1. 
and  10  seconds  With  a 
10-second  accumulation 
time,  the  frequency  can  be 
displayed  to  a  resolution  of 
01  Hz  in  the  feast  signifi- 
cant digit.  There  is  0.2  sec- 
onds between  measure- 
ments in  all  ranges. 

This  universal  counter 
chip  has  a  high-frequency 
oscillator,  a  decade  time- 
base  divider,  8-decade  data 
counter  with  latches,  a 
7-segment  decoder,  digit 
multiplexers,  and  8-seg- 
ment  and  B-digit  drivers 
which  can  directly  drive 
large  LED  displays  The 
counter  has  a  maximum  in- 
put of  10  megahertz  and, 
with  the  prescaler,  this  is  ex* 
tended  to  over  600  mega- 


tntersil  has  an  excellent 
16-page  data  brochure  de- 
scribing this  and  other 
counters  in  a  series.  I  have 

quoted  from  this  brochure 
in  many  instances  in  this  ar- 
ticle. The  A,  C  and  D  ver- 
sions of  this  counter  have 
other  characteristics  and  re- 
quire a  different  circuit 
board  layout,  so  beware. 

Signal  Conditioning 

Front-end    design    is    a 


Si     73  Magazine  •  December,  1980 


thorny  problem  since  not 
enough  gain  means  that 
there  are  many  instances 
where  a  measurement  can- 
not be  made.  Too  much 
gain  and  you  will  be  count- 
ing 60  Hertz,  120  Hertz,  the 
local  radio  station,  and 
whatever  trash  is  there.  I 
think  the  front  end  given 
here  is  a  good  compromise, 
with  50-  tolOO-miflivolt  rms 
sensitivity.  The  low  fre- 
quency end  has  coverage  to 
less  than  5  Hz. 

Multiplexed  Inputs 

The  function,  range,  con- 
trol, and  external  decimal 
point  inputs  are  time-multi- 
plexed to  select  the  input 
fynction  desired.  This  is 
achieved  by  connecting  the 
appropriate  digit  driver  out- 
put to  the  inputs.  The  input 
function,  range,  and  control 
inputs  must  be  stable  dur- 
ing the  last  half  of  each  dig- 
it output  (typically  125  f(s}. 
The  multiplex  inputs  are  ac- 
tive  low  for  the  common 
cathode  1CM7216B. 

Table  1  shows  the  func- 
tions selected  by  each  digit 
for  the  multiplexed  inputs. 
You  will  note  that  some 
possible  functions  are  not 
implemented  in  my  circuit 
board. 

Control  Input  Functions 

Display  Test  — All  seg- 
ments are  enabled  contin- 
uously; giving  a  display  of 
all  8s  with  decimal  points. 
The  display  wilt  be  blanked 
if  Display  Off  is  selected  at 
the  same  time. 

Display  Off  —  lo  enable 
the  Display  Off  mode,  it  is 
necessary  to  input  D3  to  the 
control  input  and  have  the 
HOLD  input  at  V  +  .  The 
chip  will  remain  in  the  Dis- 
play Off  mode  until  HOLD 
is  switched  back  to  V  — 
While  in  the  Display  Off 
mode,  the  segment  and  dig- 
it driver  outputs  are  open. 
During  Display  Off,  the 
oscillator  continues  to  run 
with  a  typical  supply  cur- 
rent of  1  5  m A  with  lO-MHz 
crystal  and  no  measure- 
ments are  made.   In  addi- 


-9V 


lOO&F 


A  IN 


•SV         ♦SV 
4 


i77 


i;*« 


:^afif 


fh 


m 


t 


5K 


'^t^ 


A  7K 


^2H2Z2Z 


SEE 


iDOvF 


,lpF 

>— J jl   *    -Wl.    II 1 1^ — 

am;  I 

IIN9I4  \ 


2l«ie^3 


^e 


\A7^V 


fTT 


m 


01 


01 


/fr 


01 


m 


Fig.  2,  Signal  conditioner  part  of  main  board. 


PftESCALE   IK 


«>*«       gf* 


J  ' 


FD. 


*       ■ 


•*ot*» 


»f«T 


CJfT  OSC  CN 


resT 


I  ^Hi  ta 


» iti 


f 


-^A  m 


\ 


4      f^CSCALE 


FffEQUEN&y- 4      I QQ} 


p^n\oo-*   ior\ 


A  ID 


uAtm 


CONTflOL     t. 


IATlO-4^1     l&ll 


2NTt»V*t    A^e(I>4) 


FUNCTrO^i   £1 


T  ^ ' 


tfmtj  ttijvc 


s 


PA^GE    III 


CJ> 


CD 1 

A     X 

£JtT    OSC   i»» 


.'0 


PQ 


Xi\ 


HAMGE    S? 


D2 


D3 


a 


SEC 

CYCLES 

DO 

,01 

1  0 

01 

0  « 

10. a 

&z 

1  Q 

lOO.O 

DS 

10  0 

IH 

CO*IMO«I  CJlTHOOE 
t  IMtT  MULTiPLEKEB 


fig.  J.  External  connections. 


tion,  inputs  to  the  multi- 
plexed inputs  will  have  no 
effect  A  new  measurement 
is  initiated  when  the  HOLD 
input  fs  switched  to  V  — . 
The  Display  Off  feature  is 
not  implemented  in  my  cir- 
cuit board  layout 

T-MHz  Select  — Jhe  1- 
MHz  select  mode  allows 
use  of  a  1 -MHz  crystal  with 
the  same  digit  multiplex 
rate  and  time  between  mea- 
surements as  with  a  1 0-MHz 
crystal.  The  decimal  point 
is  also  shifted  one  digit  to 
the  right  in  period  and  time 
interval^    since    the    least 


4 


(2.eV    I/2A 


MhtC 


m 


AM.  DIODES  lli«OOI   OR  EOUIVfttENr 


Fig.  4.  Power  supply. 


significant  digit  will  be  in 
microsecond  increments 
rather  than  0.1 -/is  incre^ 
ments. 

Fxternal  Oscillator  Enable 
—  In  this  mode,  the  external 


oscillator  input  is  used  in* 
stead  of  the  on-chip  oscilla- 
tor for  timebase  input  and 
main  counter  input  in  peri- 
od and  time  interval  modes. 
The  on-chip  oscillator  will 


73  Magazine  •  December,  1980     59 


illf^UT 


t^ 


l» 


OUTPIJT 


Fig,  S.  Prescater,  This  divide-by-one-hundred  prescaler  has  a  grounded-base  input  stage 
and  gives  good  performance  to  over  450  MHz. 


continue  to  function  when 

the  external  oscillator  is  se- 
lected. The  external  oscilla- 
tor input  frequency  must  be 
greater  than  100  kHz  or  the 
chip  will  reset  itself  to  en- 
able the  on-chip  oscillator 
Hold  Input  — When  the 
hold  input  is  at  V-H,  any 


measurement  in  progress  is 

stopped,  the  main  counter 
is  resets  and  the  chip  is  held 
ready  to  initiate  a  new  mea- 
surement  The  latches 
which  hold  the  main  count- 
er data  are  not  updated,  so 
the  last  complete  measure- 
ment   is   displayed.    When 


hold  is  changed  to  V~,  a 
new  measurement  is  ini- 
tiated. 

Reset  tnput  — The  reset 
input  is  the  same  as  a  hold 
input,  except  that  the  latch- 
es for  the  main  counter  are 
enabled,  resulting  in  an  out- 
put of  all  zeros. 


o 


Q 


-**■ 


Fig.  6faJ.  Main  counter  board. 


^^^:^^  Q  Q       f 


01 


47^  F 


■M- 


FUNCTION 
■♦ O    q    g   »    » 


JOK 


»    ■    »    » 


a   B   •^  DIGIT 


t      i-oi 


iCMTEieaiPT 


lOK 


loon 


4VF 


,   ^  lOOpF 

"^Vf^l      2N3&Z3       —^y- 


lOOK 


a 


5K 


looa: 


T4i5 


moK 


47KJ      ojJ_-r 


3K 


SEGMENT  ^>-*-* ■   *   ■  *  * 


OSC 
O 


I 


€8pF_L     <IM 


It 


^  VAR  Q 


Fig.  6(b].  Component  layout,  main  counter  board. 


(OOK 

■^WNr 


lOOpF 


^^ 


UF 


Range  Input  — The  range 
input  selects  whether  the 
measurement  is  made  for  1 , 
TO,  100,  or  1000  counts  of 
the  reference  counter  In  all 
functional  modes  except 
unit  counter,  a  change  in 
the  range  input  will  stop  the 
measurement  in  progress 
without  updating  the  dis- 
play and  then  Initiate  a  new 
measurement.  This  pre- 
vents an  erroneous  first 
reading  after  the  range  in- 
put is  changed. 

Display  Constderaftons 

The  display  is  multi- 
plexed at  a  500-Hz  rate  with 
a  digit  time  of  244  ps.  An  in- 
terdigit  blanking  time  of  6 
ys  is  used  to  prevent  ghost- 
ing between  digits.  The 
decimal  point  and  leading 
zero  blanking  have  been 
implemented  for  right-hand 
decimal  point  displays.  Any 
zeros  following  the  decimal 
point  will  not  be  blanked. 
Also,  the  leading  zero 
blanking  will  be  disabled 
when  the  main  counter 
overflows. 

The  ICM7216B  is  de- 
signed to  drive  common 
cathode  displays  at  peak 
current  of  15  m A/segment 
using  displays  with  Vf  =  1,8 
V  at  1 5  m A,  Resistors  can  be 
added  in  series  with  the  seg- 
ment drivers  to  limit  the  dis- 
play current  in  very  effi- 
cient displays  if  requtred 

To  get  additional  bright* 
ness  out  of  the  displays, 
V+  may  be  increased  up  to 
6.0  V.  However,  care  should 
be  taken  to  see  that  maxi- 
mum power  and  current  rat- 
ings are  not  exceeded. 

The  display  consists  of  8 
digits  of  multiplexed,  com- 
mon-cathode LEDs,  A  cir- 
cuit board  for  the  popular 
MAN  74  is  given.  Calculator 
displays  are  available  at  su- 
per savings— 8  or  9  digits  on 
a  circuit  board  for  a  dollar. 
You  can't  beat  thatl. 

Crystal  Characteristics 

The  circuit  board  has  fa- 
cilities for  HC-33  or  HC-18 
crystal  holders  The  oscilla- 
tor  is    implemented    as    a 


60     73  Magazine  •   December,  1980 


high'gain  complementary 
MOS  inverter.  An  external 
10-  or  22-megohm  resistor  is 
used  for  biasing.  The  oscil- 
lator is  designed  to  work 
with  a  parallel  resonance, 
10-megahertz  crystal  cali- 
brated with  22  pF  and  hav- 
ing a  series  resistance  of 
less  than  35  Ohms,  You 
should  not  try  to  save  mon- 
ey here  since  the  accuracy 
of  your  counter  is  directly 
dependent  upon  the  accu* 
racy  of  this  oscillator.  You 
should  specify:  A-T  cut,  op- 
timum angle,  and  commer- 
cial quality  and  accuracy. 

Prescaler 

The  prescaler  uses  a 
grounded-base  amplifier 
driving  an  11C90  bOfrMHz 
divide-by-ten  followed  by  a 

74196  divide-by-ten,  result- 
ing in  a  divide-by-100  cir- 
cuit.   The    grounded-base 

ampiif ier  yields  a  sensitivity 
of  20-  to  50-milIivolts  rms 
and  will  respond  to  a 
1-Watt  handie-talkie  sever- 
al yards  away  with  a  quar* 
ter-wave  antenna  connect- 
ed to  the  prescale  input 
jack.  Slightly  better  fre- 
quency response  from  the 
74196  was  obtained  by  us- 
ing 5.7  volts.  The  voltage  is 
reduced  to  5  V  for  the 
11C90  by  the  silicon  diode. 
The  prescaler  draws  about 
200  mA  from  the  5J-volt 
supply. 

Power  Supply 

As  the  total  current  is  on- 
ly 300  mA  or  so,  the  simple 
power  supply  shown  will  be 
OK,  Turning  off  the  prescal- 
er results  in  a  savings  of  200 
mA,  so  battery  power  is  a 
reasonable  option  by  using 
a  9-voft  transistor  radio  bat* 
tery  for  portable  use. 

Conslruction 

This  is  where  the  satisfac- 
tion of  home-brew  electron- 
ics really  comes  forth.  Your 
workmanship  will  be  there 
for  all  to  see,  so  a  few  dol- 
lars spent  for  a  good-look- 
ing box  will  buy  much  as  far 
as  satisfaction  goes.  You 
may  not  want  to  implement 


Fig.  7(al  Prescaler  board. 


Fig.  7(b).  Component  layout 


all  six  functions  or  all  four 
ranges;  this  would  simplify 
the  front  panel.  The  use  of 
rainbow  or  ribbon  wire  will 
simplify  the  segment,  digit, 
function,  and  range  wiring. 

Conclusion 

Two   of   these   counters 


Fig.  8.  Display  board. 

were  constructed,  and  good 
results  were  obtained  with 
both.  This  is  a  fun  project 
with  little  chance  for  prob- 
lems. Circuit  boards  can  be 
obtained  from  O  C.  Staf- 
ford, 427  S.  Benbow  Road, 
Greensboro  NC  27401. 
Write  Ozzie  at  that  address 


for  a  price  list  of  both  cir- 
cuit boards  and  any  other 
parts  you're  having  trouble 
finding. 

I  will  gladly  correspond  if 
you  will  send  an  SASE  with 
your  questions,  I  hate  to  be 
this  way,  but:  no  SASE,  no 
replyl  ■ 


Parts  List 

Main  Board 

Prescaler 

Resistors 

Qty, 

Resistors 

Qty. 

100Q.  V4W 

2 

100  Q,  V4  W 

1 

3k  Q,  V4  W 

2 

150  Q.  Va  W 

1 

4.7k  Q,  V4  W 

4 

470  Q.  %  W 

1 

10k  Q,  1/1  W 

3 

680  Q.  V4  W 

1 

100k  Q,  y*  W 
1  rnegohm,  V*  W 
10  megotim,  V<  W 
5k  (TO-5}  pot 

5 
2 
1 
2 

Capacitors 
,01-^F  disc 
10*fiF  tantalum 

Other  Parts 

5 
1 

Capacitors 
5.8-pF  disc 
39-pF  disc  NPO 

100-pF  disc 

2 
1 
2 

1N4001 
2N5179 
1 1 C90DC 
SN74196 

1 
1 

t 
1 

.01 -^F  disc 

4 

4  J-^H  coil 

1 

0.1-pF  disc  or  tantalum 
4,7-^F  tantalum 
47-^F  tantalum 
47-fiF  axial  tantatum 
50-pF  variable 

2 

2 
2 
1 
1 

Counter 

Common-cathode  display 
Function  switch 
Range  switch 
Prescale  switch 

(see  text) 
1P6T 
1P4T 

2P2T 

Semiconductors 

Hold  switch 

1P'NO 

1N914 

7 

Reset  switch 

IP  NO 

2N2222 

2 

1  MHz  En.  switch 

1P1T 

2N3823 

2 

Ext.  osc,  en.  switch 

1P1T 

SN7413 

1 

Display  test  switch 

IP-NO 

ICM7216  BIPI 

1 

Coax  jack  (BNC) 

4  each 

10-MHz  crystal 

(see  text) 

Power  supply 

(see  text) 

73  Magazine  •  December,  1980     61 


SCR  WOO  VHF—SCR4000UHF 


For  Your  New  Repeater  or  Link  System, 


2mr. 
22011/IHz 

450  MHz 


m  sow  Output 
Low  NoiseAIVide  Dynamic 
Range  Front  End  for  Excel- 
lent Sensitivity  &  IM  Rejec- 
tion. 

•  Sensitivity:  0.3uV  Typ. 

•  12  Pole  IF  Filtef,  &  S  Pole 
Front  End  Filter. 
Full  Metering,  Lighted 
S!a  tu  s  t  nd  tea  tors/Conlr ol 
Pushbuttons,  Btry,  Power 
Input,  AC  Pwr.  Supply,  CW 
lOer,  etc.  etc. 


Or,  to  Replace 
Your  Old  ^Klunker^r 


y 


4 


if  you  pfan  to  instaff  a  new  Repeater  or  VHFf 
Ltnk  System  (with  or  w/o  Autopatch),  you1l  find 
that  you  can't  find  better  quality,  more  reliable 
equipment,  with  all  of  the  features  and  options 
you  want  at  anywhere  near  ouf  prices—If  you 
can  find  it  at  all! 

For  many  years  now.  we  have  specialized  specif- 
icalty  in  the  fiefd  of  VHF/UHF  Repeaters,  Links, 
Transcetvers  and  all  of  the  accessories  to  mal^e- 
up  a  complete  system.  We  now  have  hundreds  of 
repeater  and  link  systems  operating  success- 
fully all  over  the  worid!^ 

When  you  buy  Spec  c5Smm  gear,  you  get  the 
berjBfit  of  ail  of  these  years  of  expeoence — you 

best!  And,  years  from  now,  you'll  stiitbe 

i  went  with  Spec  Comm! 

Shown  in  Oplionai  Cabinet 


Made  in  US 


SCR1000 

ARE  FCC  TYPE 
ACCEPTED 

for  Commercial  \ 
Services 


30  or  jo  WATTS 
on  2  n/lirs.  I 


Avaitabie  ju^t  the  way 

various  repeater  functloTtsT' PL":  "Emergency  Pwr.  ID.":  various  Tone  &  Timer  Units,  etc.  PLUS—the  finest  Duplex* 
ers,  Cabinets,  Antennas,  Cables,  etc.  Our  Repeatlrs  are  sold  fa^ry  direct  only,  or  through  Foreign  Sales  Reps.  Get 
your  order  In  A.S.A.P.^ 


180  O^jy  Warranty 
Call  or  write  today  and  get  the  detaits^ 


SPECTRVM 

Export  Orders  -  Contact  our  internatianat  Depi. 


1055  W.  Germantown  Pk„  Dept,  S10 


62     73  Magazine  •  December,  1980 


COn/mERCML  MOBILE  & 


^  BASE  TRANSCEIVERS 

136-174  HUHz 


if 


'peatttied 


'6  channels. 

0.35Livncvr- 

'6  Pote  Crystal  F(tr. 

I  Beauiltui  Audio— RX  +  TX 

I  Provtsion  tor  CTCSS- 

Very  Reasonable  Pri<;el 


PCL250  30  Wt. 
Mobile  Unit 


220^2^0 H^HM  ( ^jMMuvfic^  Si^^^  limd^^ma^m  ) 


Very  attrac^rve  woodgrani  tiousing. 


Super  Rugged''  Housing 

Sofld  Vt "  Thk^  Aircraft  Aluminum!  ^^^ 

^  FCCTYPE  ACCEFTED- PARTS  21,  ST,  90  0 


•  Buitl-m  AC  Power  Supply  n^»si  nnn.  ntk 

•  Front  Panei  SUtus  Indtcator  Lights  PCL300  30  Wu 

•  Opironal  Rcvr  Scanntng  Function  Available.  BdS6  StStlOll 


SCR450 
BOARD 


SPEC  COMM  REPEATER  BOARDS  &  SUB-ASSEMBLIES 

These  are  PrQfessionaf  "Commercial  Grade"  Units — Designed  for  ExU&me  Environments  f  -  30  to  +60"  C). 

All  equipment  assembted  &  tested.  For  2M,  220  MHz  &  New  450  MHzl 


SCRtOO  VHF  Receiver  Board 


'de- 


•  Wide  dynamic  range'  Reduces  overload 
sense    and  IM 

•  Sens.  0.3  uV/12dS  StNAD  lyp. 

•  Sen    .6dB  (a    *  6.5  KHj.    llOdS  Ot    *2QKHz.[B 
Pole  Cf¥Sta^  FItr } 

•  "S  Meter^  OuTpul 

•  E3(C.   audio  qusEityi    Fast  squelch!   w/O.0O05% 
Crystal 

SCR100  Receiver  Assembly 

•  SCRIQCI  mountsd  in  shivtded  housing 
«  Same  as  used  on  SCRTOOO 

•  Completely  asmbld.  wff  T  caps,  S0239  conrt,, 
AFGAIN  POT.  etc. 

SCR450  UHF  Receiver   Bd.  or  Assy. 

•  Stmilar  lo  SCRIOO.  except  with  12  Pole  IF  Fltr„  &  B 


Resonator  FronI  End  Fitr.i 
Discrrminator  &  Devration  Mtr  Outputs 
Totaliy  New  Advdncedl  Design i 


tv 


^ 


FL'6 


FL-6  Rcvr  Front- End  Preselector 

»6  Hf  Q  R&M>nators  with  Li> Noise  Transistor  Amp  (2M  or 

220  MHz). 
^Provides  tremendous  rejection  of  "out-ol-band'^  signals 

w^oai  the  usual  loss!  Can  often  t>e  used  rnsiead  of  large. 

expensive  cavity  filters. 

>  EKtremely  helpful  at  sites  with  many  nearby  VHF  transmit- 
ers  to  "filter-out"  these  out-oJ-band'  signals. 

►  Voltage  Gain:  apx   10  dB. 

I  Selectivity:  -^0  dB  @    +2.0  MHi^  -60  dB  m    ±6  MH2 

(typ.). 


IDIOOO  Auiamaiic  Base 
SiBiian  CW  Mentiiier 


*0n]HATH 


•  For  Repeaters,  Base  Xmirs.,  etc. 

•  Fully  Autornatic  \D  liming  &  Tt.mu  keying, 

•  Convenient  Front  Panel  Conlrois,  Many  Delude 
Fe  Sly  res' 

•  AC  Of  DC  powered 

•  Easy  10  ir»stall!  19"  Rack  Mouni 

•  Reasonable  Price!  AsK  for  Data  Sheet 


]W^' 


SCT410  XMTR.  ASSY, 


sen  10  VHF  Xmtr/Exciter  Board 

•  7  or  10  Wis.  Output    T00%  Duty  Cycle! 

•  Infinite  VSWR  proof 

•  True  FiM  lor  estc  audio  qualMy 

•  New  Design— apeciffcaiiy  for  continuous  rpir 
service 

•  Very  low  m  "white  rioise" 

•  Spurious  -  70  dB,  Harmonics  -60dB 

•  With  0005%  3(tat 

•  6A-10  30  Vti.  Amp  board  Bi  Heal  Sink.  3  sec,  LP 

Ftfter  &  fel.  pwr.  sensor. 

SCT1 10  Transmitter  Assemt^fy 

•  SCTnO  mounted  in  shiietded  housing 

•  Same  as  used  on  SCRIOOO 

•  CompleieJy  assmbld.  w/F.T.  caps,  S0239  conn. 

•  7.  10  or  30  Wt.  unit. 

SCT410  UHF  Transmitter  Bd.  or  Assy. 

•  Similar  to  sen  10.  8-10  Wts. 

•  A va  i  I .  w/  or  w/o  OS- 1 B  S  u  p«r  H^gh  Stifa JH  ty  Crystt  I 
OscJOvttn. 

•  BA  40  30W.  min.  UHF  Amp.  Bd.  &  Heat  Sinlt. 


SCAP  Autopatcti  Board 

•  Provides  all  basic  autopatch  funclions 

•  3  Digit  Access;  i  Auk  On/Oft  lunctton.  Audio 
AGC;  Built-in  Timers;  etc 

•  Of1  Inhibit  bd.  also  available. 

•  WrJIe/call  for  dslaiis  and  a  data  sheet. 

RPCM  Board 

•  Used  w/SCAP  board  to  provide  "Reverse  Patch" 
and  Land-Line  Control  ol  Repeater 

•  Includes  land  line  "answering'  circujlry^ 


PSM-1  Repeater  Power  Suppiy  Mod  Kit 

For  SCR- 1000  or  SCR-4t}00 

Rep! aces  Darlington  Pass  Jr.— tof  improved 

refi^biifty 

Includes  new  overvoitage  '"Crowbaf"  shut-        i 

down  circuit. 

Complete  kit,  wiassembied  PC  board  119.50 

+  S2.50  SH, 

iD250  CW  JO  &  Audio  Mixer  Board 

Adjustable  ID  tone,  speed,  level,  liming  cycle. 

4  Input  AF  Mixer  £,  Local  Mic  amp. 

COR  input  &  xmtr.  hold  circuits. 

CMOS  logic;  PROM  memory— 250  bilS^channel.. 

Up  io  4  differer>t  ID  channels! 

Many  other  features  Factory  Programmed 


TTCIOO  Touchtone 


Controi  Board 


3  dig  it  ON,  3  digit  OFF  control  of  a  single  repeater  tunc- 

1  i  on.  Or,  ( opt  ion  a  1}  2  f  u  n  ct  i  ons  {2  d  i  g  i  t  s  OHIO  F  F  eac  h). 
Can  be  used  to  putt  irh  a  relay,  trigger  logic,  etc 
Typically  used  for  Rptr    OM/OFF,  HlfLO  Pwr, 
P  L   ON/OFF.  Patch  lnh^b^t^fleset,  etc. 
Stable,  anii'laismg  oesjgn  5s  Limit  on  access 
For  Addl  FunctJon{s)— Add  a  'P^rti&f  TTC"  Board. 


COII/mVNICJ\TiONS   CORP. 


Senti  for 
Data  5/r«9rs-' 


i^m 


Nomstown,  PA  19401    •    (215)  6311710 


*^  Reader  SefVice—see  page  226 


73  Magazine  •  December,  1980    63 


Richard  C  force  WBIASL 

Box  78 

Creenfieid  NH  03047 


Top-Banding  the  DX-60B 

part  II:  a  companion  vfo 


Part  I  of  WBlASL's  160-meter  conversion  for  the  DX-606  appeared  on  page  44  of  the  July  1980  issue  of  73. 


(recently  converted  the 
Heathkit®  DX-60B  to  160 
meters.  The  transmitter 
works  fine  on  that  band, 
with  one  drawback:  It  is 
crystal  controlled.  This  fact 


adds  inconvenience  to  the 
operation  even  though 
there  are  four  crystal  posi- 
tions provided.  The  ability 
to  move  at  will  around  your 
allocated    portion    of    the 


Photo  A.  Front  view  oi  the  vfo  showing  use  of  the  ARCS 
cabinet.  The  front  is  covered  by  a  copperclad  plate  for  ap- 
pearance's sake  and  for  dial  mounting, 

64     73  Magazine  •  December,  1980 


band  not  only  eases  opera- 
tion, but  also  cuts  down  on 
operator  frustration  caused 
by  unanswered  responses 
to  CQ  calls.  With  many  op- 
erators using  transceivers 
nowadays,  they  do  not 
bother  to  tune  after  a  call, 
but  expect  a  response  only 
on  their  own  frequency. 
After  many  such  unan- 
swered calls,  I  decided  to 
add  a  vfo  to  my  newly-con- 
verted rig. 

The  DX-60B  transmitter 
was  originally  designed  to 
be  used  with  the  Heathkit 
HG-10B  vfo  on  80-10  me- 
ters. In  fact  the  unit  comes 
with  a  vfo  accessory  power 
socket  provided  on  the 
back,  as  well  as  a  vfo  input 
and  a  vfo  position  on  the 
crystal  switch.  The  acces- 
sory socket  has  pins  for 
ground,  63  volts  ac,  300 
voks,  keying  bias,  and  a 
110'Volt  ac  line  for  power- 
ing a  relay  for  antenna 
change-over. 

With  these  facts  in  mind, 
1  decided  to  use  the  existing 
provisions  and  design  a  vfo 
similar  to  the  HC-lOB  to  be 
used  with  the  DX-60B  on 
160  meters.  This  vfo  would 
be    compatible    with    the 


power    and    switching    cir- 
cuits provided. 

Because  the  HG-10B  is  a 
vacuum  tube  vfo,  it  seemed 
only  reasonable  to  use  vac- 
uum tubes  in  the  new  de- 
sign. The  tubes  I  selected 
are,  however,  very  easy  to 
obtain  even  in  this  age  of 
solid  state. 

The  circuit  is  straightfor- 
ward and  operates  on  the 
fundamental  frequency  of 
1.8-2  MHz.  The  6AU6  tube 
operates  as  a  Hartley  oscil- 
lator on  this  fundamental 
frequency.  Grid-block  key- 
ing is  used,  with  the  keying 
bias  provided  from  the  ac- 
cessory socket  of  the  DX- 
60B.  The  bias,  which  is  ap- 
plied to  the  grid  of  the 
6AU6  through  the  NE-2 
neon  lamp  and  R2,  is  suffi- 
cient to  cut  off  the  oscilla- 
tor during  standby.  When 
this  bias  is  removed 
through  keying  the  trans- 
mitter, the  oscillator  re- 
sumes oscillation. 

The  6C4  tube  acts  as  a 
buffer.  This  tube,  by  the 
way,  can  be  replaced  by 
one-half  of  a  12AU7  or 
12AT7  or  even  by  a  6J6  if 
the  6C4  cannot  be  found. 
The  circuit  helps  to  main- 


tain  the  stability  of  the 
oscillator  by  establishing  a 
fixed  load  for  the  oscillator 
output 

Of  course,  the  0A2  tube 
is  a  voltage  regulator  to  en- 
sure that  the  voltage  to  the 
vfo  remains  at  150  volts. 

As  can  be  seen  from  the 
photographs,  I  made  use  of 
a  surplus  ARC-5  transmitter. 
I  used  the  chassis,  cabinet, 
and  the  coil  form  from  the 
oscillator  section.  The  coil 
form  was  used  for  LI  in  the 
new  vfo.  All  frequency 
range  models  of  the  ARC-5 
use  the  same  coil  forms,  so 
any  ARC-5  unit  will  have 
the  needed  form. 

This  coil  form  is  made  of 
ceramic,  which  is  a  very 
good  material  for  the  wind- 
ing of  oscillator  coils.  An- 
other coil  form  and  chassis 
can,  of  course,  be  substi* 
tuted  if  you  do  not  have  a 
surplus  ARC-5  transmitter 
lying  around  the  house. 
(They're  getting  rarer  all  the 
time,  but  are  still  available 
from  some  surplus  out- 
lets—although at  a  cost 
much  too  prohibitive  for  an 
oscillator  coil  and  a 
cabinet.) 

Be  very  selective  about 
the  coil  form  material  to  en- 
sure stability  in  the  trans- 
mitter, Ceramic  is  best,  but 
whatever  material  you  use 
for  the  form,  make  sure  the 
wire  is  wound  tightly  over 
the  form  and  cemented  in 
place  with  Q-Dope.  Avoid 
toroid  cores!  They  are  very 
susceptible  to  frequency 
drift,  especially  in  vacuum 
tube  environments  where 
there  can  be  a  high  degree 
of  change  in  the  ambient 
temperature.  Also  avoid 
slug-adjustable  core  forms. 
U  you  must  change  the  di- 
ameter of  the  coil,  experi- 
ment with  the  number  of 
turns  until  you  get  the  right 
resonant  frequency  range. 
You  also  can  resort  to  a  coil 
chart  or  coil  design  for- 
mula, but  in  all  cases  keep 
the  coil  Q  quite  high. 

As  for  the  chassis,  you 
can  see  from  the  photo- 
graphs that  there  is  plenty 


of  extra  space  in  the  ARC-5, 
so  a  different  chassis  and 
cabinet  could  actually 
reduce  the  size  consider- 
ably. 

Mechanical  stability  in 
construction  as  well  as  heat 
shielding  are,  of  course,  of 
paramount  importance  as 
they  are  in  all  oscillator 
construction  By  mounting 
the  coil  below  the  chassis,  it 
is  shielded  from  drafts  and 
variations  in  temperature 
after  initial  warm-up. 

A  sturdy  bracket  was  fab- 
ricated for  the  mounting  of 
capacitor  C3.  This  helps  en- 
sure that  an  accidental  jar- 
ring of  the  cabinet  will  not 
change  the  frequency  of 
the  oscillator  Also,  keep 
component  leads  as  short 
as  possible  for  the  same 
reason  and  to  cut  down  on 
lead  inductance. 

All  frequency-determm- 
ing  capacitors  should  be 
either  silver  mica  or  poly- 
ester types  for  stability. 

The  inclusion  of  the  0A2 
regulator  keeps  the  voltage 
to  the  oscillator  rock 
steady,  which  is  needed  for 
stability  purposes. 

By  following  these  good 
construction  practices,  I 
can,  after  initial  warm-up, 
zero-beat  the  vfo  to  a  stable 
receiver  and  come  back  an 
hour  later  and  still  be  on 


Photo  B.  Top  view  of  the  vfo.  The  copperctad  board  is 
used  to  cover  holes  in  the  chassis  and  to  mount  vfo  parts. 
The  6AUb  tube  is  in  the  front,  the  6C4  is  in  the  center,  and 
the  0A2  is  in  the  rear. 


zero  beat-  The  amount  of 

drift  is  infinitesimal. 

After  constructing  the 
vfo,  tune-up  and  testing  are 
simple  matters  First,  check 
all  your  wiring  to  make  sure 
it  is  correct.  Especially 
check  to  see  that  the  power 
connections  are  wired  to 
the  power  plug  correctly.  If 
you  are  like  most  of  us,  you 
probably  haven't  used  octal 
sockets  in  years  and  the 
numbering  of  the  pins 
might  not  be  fresh  in  your 
mind.  Check,  and  check 
again.  Tubes  are  expensive, 
and  they  don't  like  to  have 
TlOor  300  volts  on  their  fil- 
aments. 

One   preliminary  adjust- 


ment can  be  made  before 
the  vfo  is  connected  to  the 
DX-60B.  If  a  grid^ip  oscilla- 
tor is  available,  the  vfo 
tuned  circuit  can  be  dipped 
to  the  160meter  band  Do 
this  by  setting  the  main  vfo 
tuning  capacitor,  C3,  to  the 
center  of  its  range.  Set  the 
grid-dip  oscillator  to  19 
MHz.  With  the  grid-dip  os- 
cillator coil  coupled  to  LI. 
tune  trimmer  capacitor  C2 
for  a  dip  on  the  meter.  Now 
the  oscillator  is  tuned  for 
approximately  the  center  of 
the  160-meter  band.  (If  you 
do  not  have  a  grid-dip  oscil- 
lator, an  alternative  meth- 
od follows.) 

After  all  is  checked  out. 


KErrNO 

I  PIN  e  DKGoa 


tlUE^ 


©'* 


ftf 


:c3 


J# 


ni 


fft       fft       ffj 


>T^Cf      j'ca   5C( 


ca 


ns 


GC4 


6AU« 


>*— T'"4»-» 


as 


m 


■^^^- 


c« 


♦  3O0V  * WrtP- 

PiH  4 

0X6OB 


CS 


/fj 


«6 


fiS 


CtO 


f- 


OUTPUT 
TO  VFO 
IMPUT 
DM«OS 


CV2 


«C4 


GI?t>UflD 


*  $VAC 


m 


ff^ 


fig.  7.  Vio  schematic. 


73  Magazine  *  December,  1980     65 


Photo  C.  Bottom  view  of  the  vfo,  showing  coit  LI  at  the 
left  center  and  C3  mounted  on  the  bracket  at  the  left.  As 
can  be  seen,  there  is  an  excess  of  space. 


plug  the  vfo  power  cprji  in- 
to the  DX-60B  power-acces- 
sory socket  and  the  rf  out- 
put from  the  vfo  into  the 
vfo  input  socket  on  the 
back. 

Turn  the  Function  switch 
to  "Standby/'  check  to  see 
that  the  tubes  in  the  vfo  are 
lighting,  and  let  the  unit 
warm  up  for  at  least  one- 
half  hour. 

Set  the  controls  on  the 
front  of  the  DX-60B  as  fol- 
lows: Drive  Level  to  0,  Xtal 
to  vfo.  Drive  Tune  tol,  and 
Band  to  80  (which  is  now 
the  160-meter  position). 

The  next  step  will  need 
the  services  of  a  good,  ac- 
curate communications  re- 
ceiver which  covers  the 
160-meter  band.  Set  the 
receiver,  after  warm-up,  to 


the  center  of  the  160-meter 
band.  Run  a  wire  from  the 
receiver's  antenna  terminal 
to  a  point  near  the  vfo  to 
ensure  the  receiver  will  pick 
up  the  signal  from  the  vfo. 

Now,  turn  the  Function 
switch  to  the  'Tune"  posi- 
tion. Tune  the  vfo  main  tun- 
ing capacitor,  C3,  through 
its  range  while  listening  for 
the  signal  in  the  receiver 

If  the  signal  is  not  heard 
and  the  receiver  is  a  general 
coverage  receiver,  leave 
the  vfo  capacitor  set  to  the 
center  of  its  range  and  tune 
the  receiver  both  above  and 
belov^  the  160-meter  band 
until  the  signal  is  found.  If 
the  signal  is  higher  than  the 
band,  capacitor  C2  will 
have  to  be  adjusted  to  add 
more    capacitance    to    the 


Parts  List 

C1— 270-pF  polystyrene  or  silver  mica 
C2— 3-30-pF  mica  trimmer 
C3— 30pF  air  variable  {Hammarfund  HF-30) 
C4— 100'pF  polystyrene  or  silver  mica 
C5,  C6,  C8,  C9,  C11— .02-uF  disc  ceramic 
C7— .001  uF 
CIO— 150  pF 

LI— 35  turns  #18  AWG  enamei  on  a  1-3/S" 
^ceramic  form  (see  text) 
R1— 47  k,  Vi  W 

W 


Vz 


R2.  R4— 1&0k, 
R3-33k,  Vz  W 
R6-^1000.  V2  W 
R6— 2700,  V^  W 
RT-'IOk,  Vz  W 
R8— 5.6k,  7  Watt 
RFC1— 2.5-mH  rf  choice 
NE-2 — Neon  lamp 


circuit  to  bring  the  oscilla- 
tor within  the  band.  If  the 
signal  is  below  the  band,  C2 
will  have  to  be  adjusted  to 
decrease  the  capacitance. 

if  the  signal  is  not  heard 
and  the  receiver  only  cov- 
ers the  160-meter  band,  set 
capacitor  C3  to  the  center 
of  its  range  and  the  receiver 
to  1.9  MHz.  Adjust  capaci- 
tor C2  until  the  signal  is 
heard.  If  it  is  still  not  heard, 
keep  alternating  capacitor 
adjustments  on  C2  and  C3 
until  it  is  heard. 

If  the  signal  cannot  be 
found  at  all,  either  the  oscil- 
lator is  not  oscillating  or  its 
frequency  range  is  com- 
pletely out  of  the  range  of 
the  receiver.  Check  all  com- 
ponents and  voltages,  tf  an 
absorption  wavemeter  is 
available,  use  it  to  deter- 
mine if  the  oscillator  is 
oscillating.  Once  it  is  deter- 
mined that  the  oscillator  is 
functioning  outside  the  de- 
sired frequency  range,  a 
few  minor  changes  will 
have  to  be  made  to  the  os- 
cillator to  bring  it  into  line. 
This  will  entail  either  in- 
creasing the  ambunt  of 
capacitance  in  the  tuned 
circuit  by  adding  a  small 
silver  mica  capacitor  across 
CI  to  lower  the  frequency, 
or  by  removing  turns  from 
coil  LI  to  raise  the  frequen- 
cy. This  situation  should  oc- 
cur  only  if  LI  was  rede- 
signed incorrectly  because 
of  the  use  of  a  different  coil 
form. 

After  the  signal  is  found, 
one  way  or  another,  listen 
to  the  signal  for  purity  of 
tone  (no  hum  or  hash).  Turn 
the  vfo  off  and  on  by  turn- 
ing the  Function  switch  to 
''Standby''  and  then  to 
''Tune"  again  several  times 
to  make  sure  oscillation  be- 
gins immediately.  After 
these  observations,  check 
for  drift  by  zero-beating  the 
signal  on  the  receiver  (with 
the  receiver  vfo  turned  on) 
and  letting  the  oscillator  sit 
for  awhile  to  see  how  far  it 
drifts  from  zero  beat.  A  bet- 
ter alternative  method  to 
check  drift  would  be  to  use 


a  frequency  counter.  If  ex- 
cessive drift  occurs,  a  bad 
capacitor  or  LI  may  be  the 
cause.  Check  voltage  stabil- 
ity and  drafts  also. 

If  all  checks  out  al!  right, 
you  may  then  proceed  to 
the  next  step,  that  of  cali- 
bration. Set  the  main  tuning 
capacitor,  C3,  to  maximum 
capacitance.  Tune  the 
receiver  to  the  bottom  of 
the  160-meter  band.  Using 
trimmer  capacitor  C2  only, 
zero-beat  the  oscillator  to 
the  receiver.  Mark  the  dial- 
Now,  by  tuning  the  receiver 
up  the  band  to  set  intervals 
and  adjusting  the  main  vfo 
tuning  capacitor,  C3,  to 
zero  beat  and  then  marking 
the  dial,  the  vfo  can  be  cali- 
brated. 

After  calibration,  final 
testing  is  at  hand.  With  the 
antenna  output  of  the  DX- 
60B  fed  into  a  dummy  load, 
set  the  vfo  to  an  allocated 
part  of  the  band.  Proceed  to 
tune  up  the  DX-6pB.  If  you 
do  not  get  enough  grid 
drive,  check  the  buffer 
stage  in  the  vfo. 

If  all  is  operating  correct- 
ly, you  should  have  no  trou- 
ble tuning  up  the  DX-60B.  It 
should  tune  exactly  as  it  did 
when  it  was  crystal-con- 
trolled. 

To  zero-beat  a  signal  or 
to  locate  your  frequency, 
simply  turn  the  Function 
switch  to  "Tune"  with  the 
Drive  Level  control  turned 
down  and  use  the  vfo  main 
tuning  capacitor  to  zero- 
beat  the  signal, 

With  the  use  of  the  vfo, 
your  number  of  QSOs 
should  increase  dramatical- 
ly. No  lohger  will  the  other 
guy  have  to  look  for  you. 
You'll  be  right  there  on  fre- 
quency with  your  DX-60B, 

This  completes  the  sec- 
ond phase  of  my  conver- 
sion of  the,DX-60B  to  160 
meters.  It  has  been  great 
fun  doing  the  conversion 
and  operating  on  the  "top 
band."  I  hope  these  two 
pieces  will  give  many  an  op- 
portunity to  operate  on  this 
interesting  segment  of  the 
amateur  spectrum.  ■ 


66     73  Magazifte  •  December,  1980 


DOUBLE  YOUR  PLEASURE 


Versatility  Plus  . . . 

Work  Both  2  and  %  Meters 

With  Yaesu's  New  FT-720R 


The  FT'720R  series  is  a  compact  VHF/UHF  mobile  transceiver  that  harnesses  the  incredible  power 
of  the  microprocessor  to  bring  you  top-operating  flexibility.  Start  with  the  FT-720R  Control  Head,  then 
add  either  the  1 0  watt  FT-720RU  440  MHz  or  25  watt  FT-720RVH  2  meter  RF  Deck.  You  can  clamp 
the  Control  and  HF  Deck  together  or  use  an  optional  remote  cable  to  hide  the  RF  Deck. 

The  best  news  is  still  to  come!  By  using  the  optional  S-72  Switching  Box  and  two  remote  cables,  you 
can  use  a  single  Control  Head  for  operation  with  both  the  440  MHz  and  2  meter  decks,  giving  you  a 
high-perfonnance  two  band  FM  station  for  your  car  or  home.  Compare  the  features  below,  then  ask 
your  dealer  for  a  demonstration  of  the  fabulous  FT-720R  series.  .  .  another  winner  frdm  the 
performance  leader ,  .  .  Yaesu. 


Four  simplex/repeater  memory  channels, 
plus  receive-only  memory  channel. 
Scanning  controls  on  microphone  with 
search  for  busy  or  dear  channel 
Optional  32  tone  CTCSS  module  for 
accessing  private  repeaters. 
Colorful,  easy-to-read  LED  power 
output/S  meter. 
Built-in  1800  Hz  tone  generator 


Priority  channel  with  search-back  feature. 

Pause  feature  that  holds,  then  restarts  scan, 

on  busy  or  clear  channels. 

Digital  display  of  last  four  digits  of  operating 

frequency. 

Single  Control  Head  may  be  used  for  operation 

on  both  440  MHz  and  2  meters  via  optional 

switching  box  and  remote  cables. 

Exlremely  compact  size,  tight  weight 


FT*720RVH 


Specifications 


144.00-147,99  MHz 

10  kHz 

25  watts 

.32uVfOf20dB 


4^ 


?< 


Frequency  Coverage 

SynthMizer  Steps 

^'-^wer  Output 

Sensitivity 


Seter 


WV  Mi-'  t 


u  Zf— A 


FT-720RU 

440.00-449.975  MHz 
25kH2 

lOwatts 

0.5  uV  for  20  dB 

2  (— 6d8) 
„4  kHz  (—60  dB) 


r 


,4f 


7 


Thmt 


Mark  Oman  WA0RBR 

528  DGines  Ct 

ft  ColHm  CO  S0S2S 


An  Amp  for  QRPp  Addicts 

build  this  resistive  step  attenuator  for 

low;  low  power  work 


Internal  view  of  QRP  Amp  showing  switches  and  conneo 
fions. 


After  having  enjoyed 
QRP  operation  and  its 
2-Watt  world  for  a  period  of 
time,  it  was  decided  that  a 
new  frontier  was  needed  for 
a  challenge.  An  amplifier 
was  designed  and  con- 
structed  which  provided  25 
Watts  on  160  through  10 
meters.  Increased  signal  re- 
ports did  result,  but  just 
about  anything  you  can 
work  on  25  Watts  can  be 
worked  on  2  Watts,  So  I  felt 
that  a  new  and  somewhat 
different  kind  of  challenge 
was  still  needed  — why  not 
an  amplifier  {an  "inverse 
amplifier")?  Rather  than  in- 
creasing the  input  signal,  it 
"inversely  amplifies;'  or  de- 
creases, the  input  (in  a  loga- 
rithmic manner). 

The  QRP  Amp  definitely 
re-instills  the  challenge  into 
the  sometimes  repetitious 
world  of  ham  radio.  It  also 
can  be  used  to  allow  QRP/ 
QRPp  operation  with  medi- 
um-powered transceivers. 
Better  yet  it  can  be  con- 
structed and  in  use  in  a  few 


hours  with  locally  pur- 
chased parts,  for  $1 5  or  less. 
If  you  have  slide  or  toggle 
switches  in  the  junk  box, 
then  the  price  is  reduced 
even  further,  It  requires  no 
tune-up  or  adjustment  and 
is  nearly  guaranteed  to 
work  the  first  time. 

The  Amp  is  actually  a 
step  attenuator  which  pro- 
vides from  3  to  39  dB  of  at- 
tenuation to  your  already 
low-power  signal  What  this 
means  is  that  your  2-Watt 
signal,  after  passing 
through  the  QRP  Amp,  now 
becomes  anywhere  from  1 
Watt  down  to  about  200  mi- 
crowattsl  Twenty  milli- 
watts of  output  power  can 
and  does  produce  plenty  of 
solid  contacts,  and  it  opens 
up  a  whole  new  world  to 
ham  radio. 

Since  the  QRP  Amp  is  a 
resistive  step  attenuator,  it 
requires  no  tuned  circuits, 
no  active  circuits,  and 
works  on  any  mode.  Refer- 
ring to  Fig  1,  it  can  be  seen 
that  four  switches  are  used 


60     73  Magazine  •  Decemt>er,  1980 


V/ew  of  QRP  Amp  shown  with  10  dB  of  attenuation  and 
switched  IN, 


in  conjunction  with  half- 
Watt  standard  value  car- 
bon resistors  to  produce  the 
necessary  attenuation  The 
double-pote,  double-throw 
switches  are  set  up  to  pro- 
duce 3,  6,  10,  and  20  dB  of 
attenuation  by  either 
switching  in  the  resistors  or 
bypassing  them  These 
switches  can  be  miniature 
toggle  type  or.  to  reduce 
costs,  miniature  slide 
switches. 

The  desired  attenuation 
is  selected  in  an  ''additive" 
manner.  To  select  13  dB  of 
attenuation,  for  example, 
switch  in  the  3'dB  and 
lO^dB  switches.  A  DPDT 
12-V  relay  purchased  at  Ra- 
dio Shack  is  used  to  auto- 
matically switch  the  attenu- 
ator out  during  receive.  It  is 
controlled  by  the  trans- 
ceiver  driving  the  Amp. 
Switch  51  is  used  to  bypass 
the  Amp,  if  desired. 

The  Amp  can  be  built  in 
just  about  any  enclosure 
available  to  the  builder 
Small  coax  (RG-174/U)  is 
used  for  rf  runs  between 
connectors,  the  relay,  and 
the  switches.  The  resistors 
should  be  soldered  directly 
to  the  switch  contacts  with 
their  leads  kept  short  to 
minimize  their  inductance, 
Spray  paint  and  dry  transfer 
lettering  add  a  final  touch 
to  the  simple  project. 

The  only  setup  required 
is  to  supply  + 12  V  and  a  re- 
lay control.  Both  can  be  ob- 


tained from  the  driving 
transceiver.  Run  a  lead 
from  the  control  side  of  the 
transceiver  relay  to  a  plug 
to  mate  with  |1.  Verify  that 
K1  closes  when  your  trans- 
ceiver is  in  transmit  and  SI 
IS  in  the  IN  position.  Actual 
attenuation  values  were 
verified  to  be  within  .5  dB 
of  the  calculated  values 
with  a  Hewlett-Packard  180 
oscilloscope.  After  you 
have  verified  that  K1  and  SI 
are  operational,  apply  drive 
to  the  box  (with  dummy 
load  attached).  With  no 
switches  IN  [no  attenua- 
tion), you  should  see  the 
same  output  power  as  input 
power.  Switch  in  3  dB  and 
the  output  should  be  de- 
creased by  one-half.  Re- 
member that  most  if  riot 
all,  power  meters  become 


View  of  QRP  Anip  shown  with  13  dB  of  attenuation  and 
switched  IN. 


inaccurate  below  1  Watt 
and  are  usually  unreadable 
below  100  mW,  so  don't  fret 
when  the  needle  doesn't 
budge  with  10  dB  or  more 
of  attenuation  switched  in. 

If  problems  arise^  about 
the  only  things  that  can  be 
wrong  are  soldered  connec- 
tions or  misplaced  resistors. 
Also,  recheck  all  wiring  be- 
tween switches,  connec- 
tors, and  relay. 

For  those  who  want  to 
use  a  200-Watt  transceiver, 
an  additional  20-dB  attenu- 
ator is  needed  to  prevent 
damage.  Use  high  wattage 
(20  Watts  or  more)  resistors 


in  that  portion  of  the  atten- 
uator. 

Operation 

Operating  the  QRP  sta- 
tion, a  portion  of  which  was 
described  in  the  December, 
1978,  issue  of  Hani  Radio, 
has  been  greatly  enhanced 
using  this  project.  Before 
describing  the  results  you 
can  expect,  you  will  be  in- 
terested in  a  few  observa- 
tions concerning  milliwatt 
operation.  Assuming  you 
are  using  a  2'Watt  transmit- 
ter  to  drive  the  Amp  and 
have  switched  in  20  dB  at- 
tenuation, your  output  will 


i3 


Hl* 


TO 

ntANaceivcR 


J*      51      out 


f 


m 


41 

aoo      @ — 
INPUT    y 

FROM        "* 
TRANSCEIVER 


42 

1 


OUTPUT 


Fig.  1.  Schematic,  QRP  Amp.  QRP  Amp  is  a  classic  pi-type  step  attenuator  using  four 
switches  to  provide  from  3  to  39dB  of  attenuation.  With  switches  as  shown,  16  dB  of  at- 
tenuation would  exist  when  SI  is  switched  to  '7N"  and  the  transmitter  is  keyed.  }1, 
12-  SO-239  rf  connector.  13, 14  -  Phone  or  phone  jack.  K1  -  DPDT  72-V  relay.  S1  -  SPS  J 
miniature.  S2-S5--DPDJ  miniature  slide  or  toggle.  All  resistors  Vi  WBtt  or  greater. 


73  Magazine  *  December  1980     69 


^^t^mm^tm 


■mi^mdMtittim^l#fl0 


^dUfa^aMHri 


:*>.;'«?T~!ry^  ■- 


DEAL  V/VTH  #1! 


CARLOAD  INVENTORIES  •  ROCK  ROTTOM  PRICES 


LINES: 

^H"nL 

iun  iiuiwii 

j^ 

AEA 

ALPHA 

CUSHCRAFT 

DENTRON 

KLM 

MOR  GAIN 

PALOMAR  ENG. 

UNIVERSAL 

AVANTI 

BEARCAT 

COLLINS 

HY  GAIN 

KENWOOD 

MIRAGE 

REGEI4CV 

UNARCO-ROHN 

ASTRON 

BERD 

CDE 

HUSTLER 

MICROLOG 

MFJ 

SWAM 

VIBROPLEX 

ALLIANCE 

BENCHER 

DRAKE 

COM 

MINI -PRODUCTS 

NYE 

TEN  TEC 

CALL  TOLL  FREE  1-800-325-3609 

MID-COM  ELECTRONICS   •    8516  MANCHESTER  ROAD   •    BRENT\ 


t^ A        IN  MISSOURI 

PW    314-961-9990 

BRENTWOOD,  MO  63144 


^-52 


-;:."-i;>}-i^;M«-.y 


if  *'.-'.■*  T/J*  * 


-T-^w-|  : 


be  20  mW.  This  power  level 
is  30  mW  below  the  FCC 
specification  for  total  har- 
monic radiation.  Further- 
more, a  typica!  SSB  tra;ns- 
ceiver  running  200  Watts 
output  might  have  40  to  50 
dB  attenuation  of  carrier 
and  opposite  sideband.  The 
ijarrier  output  will  then  be  2 
to  20  mW,  the  power  used 
with  the  Amp  to  make  con- 
tacts. 

A  quick    calculation   re- 


TO 
KIA  > 


2A0 


10   5? 
■<CEMTER  POLE 


1"   r 


Fig.  2.  20-dB  attenuBtor  to 
enable  lOO^lOO-Watt  trans- 
ceiver to  be  used  with  QRP 
Amp.  Resistors  should  be  20 
Watts  for  50-Watt  output, 
40-50  Watts  for  WO-Watt 
output  and  80-100  Watts 
for  200-Watt  output  Use 
parallel  combinations  of 
smaller  wattage  resistors  to 
reach  these  wattage  ratings. 


veals  that  if  you  can  obtain 
an  S9  report  with  a  2-Watt 
signal  (easy!),  then,  theoreti- 
cally, assuming  no  noise  or 
QRM,  an  S1  signal  would  be 
produced  by  less  than  a 
200-microwatt  signal.  This 
is  my  present  goal  with  the 
QRP  Amp. 

Naturally,  the  purist  will 
balk  at  the  idea  of  wasting 
energy  by  dissipating  power 
in  a  resistor,  but  it  is  the  on- 
ly practical  way  of  generat- 
ing QRPp  levels.  Single  tran- 
sistor rigs  which  would  nor- 
mally  generate  these  levels 
are  subject  to  chirp,  FMing, 
drift,  and  a  lack  of  conve- 
nience. With  the  Amp  and 
your  normal  QRP  transceiv- 
er, you  retain  those  conve- 
niences and  avoid  the 
aforementioned  maladies. 
It  also  considerably  re- 
duces the  expense  of  QRP 
operation  if  you  already 
own  a  regular  transceiver. 

Both  SSB  and  CW  modes 
are  used  at  my  station,  with 
SSB   slightly   preferred   be- 


cause an  in-depth  explana- 
tion can  be  made  of  the 
low-power  experiments. 
This  way,  the  other  station 
invariably  becomes  en- 
thused and  he,  too,  wants  to 
see  at  just  what  level  of 
power  he  can  hear  you. 

Contacts  have  been 
made,  however,  with  sta- 
tions who  become  indig- 
nant when  told  that  your 
power  level  is  10  mW.  Ap- 
parently, this  pricks  their 
conscience  about  that 
shiny,  expensive  linear  sit- 
ting in  front  of  them! 

During  the  past  three 
months,  10  states  have 
been  worked  in  casual  oper- 
ation, mostly  on  10  meters, 
using  10  mW  of  output.  A 
number  of  contacts  have 
been  made  in  Japan, 
Hawaii,  Canada,  and  Mexi- 
co using  100  mW  output. 
100  mW  on  10  meters  pro- 
vides plenty  of  in-USA  con- 
tacts. Even  20  meters  can 
be  used  for  10-  to  20-mW 
CW  contacts.  Incidentally, 


the  antennas  used  at  my 
station  are  a  dr pole  on  80/40 
meters  and  a  2-element 
quad  on  10-20  meters. 

As  with  any  QRP  opera- 
tion, patience  is  the  key 
word.  Not  every  station 
called  will  answer,  with  the 
ratio  becoming  worse  as 
output  power  is  reduced. 
With  a  little  practice,  you'll 
become  familiar  with  the 
conditions  and  signals  that 
will  produce  a  solid  con- 
tact. 

The  QRP  Amp  has  pro- 
vided the  challenge  that 
was  sought.  When  you  con- 
tact a  station  that  is  using  a 
linear  amplifier,  you  can  re- 
ply that  your  newest  home- 
brew accessory  is  a  log- 
arithmic de-amplifier,  built 
for  less  than  $15.  That 
should  make  for  plenty  of 
interesting  conversation! 
Plus,  there  is  fun  in  working 
across  the  continent  on  a 
power  level  most  rigs  use  to 
generate  spurious  harmon- 
ics! I 


70     73  Magazine  •   December^  1980 


n 


on  inexpensive  paper  too.  Our  latest  addition,  the  MICROLOG 

companion  printer  for  the  ATR-6800,  plugs  in  directly  for  easy  'hard 
copy'  of  your  QSO's,  messages,  programs,  etc.  When  the  tape  interface 
isn't  enough,  our  printer  is  ready  on  keyboard  command.  Complete 
system  for  CW/RTTY:  ATR-6800,  video  and  printer  $2,445,  without 
printer  $1995,  printer  alone  $495.  We're  always  up  to  something  new 
here  at  MICROLOG  CORPORATION,  4  Professional  Drive,  Suite  119, 
Gaithersburg,  Maryland  20760.  Telephone  (301)  948-5307. 


MICROLOG 

Innovators  in  Digital  Communications 


1^51 


*^  Ren^Qf  Service — see  page  226 


j:^  Magazine  ■   December,  1980     71 


Jerry  Conboy  N&RY 

2631  S^W.  Orchard  Hill  Place 

Lake  Oswego  OR  97034 


The  Center-Fed  Bizarre 

would  you  believe  an  indoor  antenna  for  80? 


More  and  more  of  us 
find  that  the  acreage 
for  that  dream  antenna 
farm  with  phased  verticals, 
rhombics,  and  giant  mono- 
band    yagjs    just    isn't 


available  on  a  lot  size 
within  the  bounds  of  our 
meager  earnings.  Even 
when  a  tidy  home  on  a 
reasonably  roomy  lot  is 
found  at  an  attractive  price, 


*■  TltAMSMtTTEl) 


Fig.  1,  A  common  configuration  for  a  VLF  antenna  using 
the  guy  wires  for  tofhioadmg  capacitance. 

12    73  Magaiine  •  December,  1980 


City  ordinances  or  deed 
restrictions  may  make  it  im- 
possible to  erect  tall  towers 
or  any  outside  antennas  at 
all.  My  situation  falls  into 
the  second  category.  Not 
even  TV  antennas  are  per- 
mitted in  my  area. 

After  two  years  at  this  ad- 
dress, I  finally  decided  that 
operating    only    on    two 


meters  with  a  magnetic- 
mount  mobile  antenna  in  a 
window  wasn't  my  idea  of 
the  ultimate  ham  station,  I 
grew  up  as  a  ham  on  the 
80-meter  band  and  wanted 
to  keep  in  touch  with  the 
friends  that  I  had  made 
over  the  years.  1  did  have 
access  to  the  club  station  at 
my  place  of  business,  but 


tsomETmc 

Vi£W 


mem 


SfOE 

¥few 


"Np' 


¥t£W 


Fig.  2.  Final  configuration  of  the  attic  antenna. 


that  often  proved  to  be  an 
inconvenient  arrangement. 
There  seemed  to  be  three 
reasonable  alternatives.  Put 
up  an  inconspicuous  out- 
side antenna,  load  up  a 
flagpole,  or  try  to  put 
something  in  the  attic.  The 
outside  antenna  was  ruled 
out,  since  a  leading  figure  in 
the  local  homeowners  asso- 
ciation was  my  next-door 
neighbor.  Decent  flagpoles 
aren't  cheap,  and  I  was  ad- 
vised by  a  lawyer  that  I  still 
might  be  subject  to  legal 
action  in  which  it  would 
cost  me  hard-earned  dollars 
to  prove  that  it  was  a 
f/agpole.  So  I  crawled  up 
my  ladder  and  made  friends 
with  the  spiders  and  the  in- 
sulation. 

Mobile  Attenuators 

I  had  acquired  a  well- 
respected  mobile  antenna 
with  a  75-meter  loading  coil 
a  few  years  ago,  but  never 
used  it.  As  a  result  my  first 
attempt  at  an  indoor  anten- 
na was  to  erect  it  io  the 
center  of  the  attiCv  Several 
wires  were  run  around  the 
rafters  for  a  ground  system. 
I  was  pleased  when  the 
swr  meter  read  14o-1  near 
the  frequency  of  interest.  I 
was  not  at  all  pleased  when 
most  of  the  stations  that  I 
tried  to  work  were  barely 
capable  of  moving  my  nor- 
mally hyperactive  S-meter 
and  seldom  able  to  copy 
me.  Some  rough  calcula- 
tions showed  that  I  really 
couldn't  expeGt  more  than 
2%  efficiency,  since  the 
radiation  resistance  of  the 
antenna  had  to  be  less  than 
1  Ohm  and  the  other  49 
Ohms  came  from  the  resis- 
tance in  the  loading  coil. 

I  was  generally  leery  of 
vertically-polarized  anten- 
nas io  the  attic  anyway. 
There  were  a  large  number 
of  metal  vent  pipes  and 
chimneys  that  were  nearby 
Most  of  them  had  friction 
joints  which  could  certainly 
create  harmonics  or  at  least 
be  lossy,  further  soaking  up 
the  meager  radiated  ener- 
gy- 


miM..*    go  >Cl  !-         ^-  ^         i,=  E       i.fl      If        W:         ll     i,l     I. 

3.h?J  M'f'   I'M  i  r'  I    I   1    \'  'f'  ^  ''V  1/  I  'i'  '1  'I  'i  '>  M   J  1^1   rii  I- 


fl3*ft      » 


ZO. 


IS. 


n  9. 

\  ■.  1 1 1  j  ii  I J  .i|T  LI  1 1  u  /  J  /  i'  n  1,1^  v^  ^"^i  tt  \  f 


k      ,       a.  3. 


7 


1 


t 


UX4 


+ 


'    ^  '     I    I     '    ■    ■    I     I    ■     I    i    I    t    I    f  ■    I    t    L    ■    .    ^    I    d    t    i    .    1     I    r  J    >    I    .    I     I    b    ■    I. 


L 


^ 


fv-i- 


"• '  ■>  I  ■ '  I ' 


I'lpt'    M'F^l'll'l 


■I'l  ^'1  > 


i: 


1.  r   r     '    .  I     ■    I    I  J      I      I    TTT       I    T    r~2     r   I  ni     ij;  .L 

f    .    ■?•  .   i  .  ir  .  .  .  .If . . .  .^      .  ,  :  V. .  .  .1-  .  ^  .  E.   .  .  .1^  II 


IJ  FJ       L3     i4  \Jt      IX     Z.  1  *       II. 

t /W ■  / 1  f 1 1 1 ■  i'?i  I'l >ti I  f  \  '■  I  |i  <  ^% \\^'  \w)\ '^*A\i- \A 

1,1  IJ  13  I.'         19       !.&      I.T     I^^B    1.9   ;..  Z.l  ) 

.as                    .9(1                .9                         jB                   .7                *              5             *         .1 
.^J i ■ i !•■■■■'■ I I I i—i I    I   *  '   I  ■  I  I   I  T I  I  1  I  r I I I ii_ 


ii_i 


i- 


tSWTER 


' 


'    '^  ■■''-''''''''     '      '     ►     '    ' "■     J     .     I     ■    •.     ■     I      I     >     P  i     I     ..     ■     F  t     I     i     I     l'     ■     ■     I     t    '^    ■  ,1.  t.    L    ITl     .     ■     1  ^^J     1     1     J     ■     I     L     I     ■  "?<     I     J     t     I     t     i     L     J     •.     I     L     I     ■     I     ■     I     >     I  't  I     I      I     . 


OR|i33N 


fig.  3.  Measured  impedance  of  the  attic  antenna.  Reference  impedance  for  the  Smith  chart 
is  50  Ohms. 


Taking  a  Lesson  from  the 
VLF  Boys 

Compact  antennas  are 
nothing  new  in  high-power 
transmitting  installations 
for  use  below  100  kHz.  A 
quarter  wavelength  is  well 
over  2000  feet  in  this  part  of 
the  spectrum.  Looking  at 
the  types  of  antennas  used 
showed  the  popularity  of 
top  loading.  This  is  no  sur- 
prise. Placing  the  loading 
away  from  the  feedpoint 
helps  keep  the  base  im- 
pedance up  to  reasonable 
values. 

As  a  rough  rule  of  thumb, 
the  radiation  resistance  of 
a    base-loaded    antenna 


changes  as  the  square  of  its 
length,  when  the  antenna  is 
less  than  a  quarter-wave- 
length  tall  (for  a  vertical]. 
For  top-loaded  antennas,  it 
changes  almost  directly  in 
proportion  to  the  length. 
For  example,  if  the  antenna 
is  one-fjfth  of  full  size,  the 
base-loaded  antenna  im- 
pedance wilt  took  like 
about  one  twenty-fifth  of  its 
full-size  impedance,  or 
about  2  Ohms.  The  top- 
loaded  antenna  will  be 
about  10  Ohms.  For  very 
short  antennas,  this  can 
give  a  significant  increase 
in  efficiency  and  band- 
width. 

One   popular  configura- 


tion for  a  VLF  vertical 
antenna  is  shown  in  Fig.  1. 
The  top  guy  wires  are  used 
as  a  capacity  hat  to  in- 
crease the  electrical  length 
of  the  radiator,  I  saw  no 
reason  why  this  configura- 
tion couldn't  be  adapted  to 
a  balanced  horizontal  ar- 
rangement, since  I  wanted 
to  avoid  vertical  radiators. 

Wire  Everywhere 

My  attic  is  about  24  feet 
wide  across  the  highest 
part,  which  is  where  I 
wanted  to  place  the  main 
radiating  portion  of  the 
antenna.  The  loading  wires 
were  bent  back  at  about  a 
55  degree  angle  from  the 


73  Magazine  •  December,  1980     73 


35-200pf       SB-EOOFiF 


^^— )f 


> 


ft! 


20 

TURNS 
Z*  DLAW 
6  T.P  I 


^t^— Gr-: 


/^ 


> 1    TAP-^-IB  TURNS 


■Ft? 


Fig.  4.  Schematic  of  the  /m- 
pedance-matching  network 
used  to  feed  the  antenna. 
This  network  is  at  the  trans- 
mitter end  of  about  100  feet 
of  RC-8  cable. 

flat-top  section.  I  didn't 
want  to  run  them  at  right 
angles,  since  the  walls  of 
my  house  are  stuccQ  and 
contain  wire  mesh  that 
could  create  problems. 

As  a  starting  point,  I  used 
a  total  of  a  half-wavelength 
of  wire.  I  had  to  bend  the 
ends  of  the  loading  wires 
back  toward  the  feedpoint 
to  get  it  to  fit  The  final  con- 
figuration is  shown  in  Fig.  2. 
As  you  can  see,  the  total 
length  of  the  wire  exceeds  a 
half-wavetength    by    about 


one-third.  It  is  resonant  near 
the  center  of  the  80-meter 
band. 

It  should  now  be  obvious 
why  this  antenna  received 
its  name.  When  I  first  put  it 
0n  the  air,  I  tried  in  vain  to 
explain  its  configuration  to 
W7ZUL,  When  it  became 
apparent  that  he  couldn't 
understand  it  without  a  pic- 
ture, I  told  him  that  it  was 
too  bizarre  to  explain.  He 
naturally  replied,  ''Oh,  so 
you're  using  a  center-fed 
bizarre/' 

The  wire  used  in  the 
antenna  was  plastic-insu- 
lated #18  with  stranded 
conductors.  Three  of  these 
wires  were  laboriously 
braided  together  to  in- 
crease the  apparent  con- 
ductor diameter  in  an  at- 
tempt to  reduce  resistive 
losses  and  to  help  broad- 
band the  antenna.  The 
three  wires  were  kept 
separate  everywhere  but  at 
the    feedpoint.    There    are 


v^^ 


^ 


ATTENTION  MOBILE  HAMS 


X5  METER  MOBILE  TRANSCEIVER 

CW  &  USB 

nCG  ISSB 


THE  QRP  RiG  WITH  THE  BiG  R/G  BOUND  ACTIVE 
NOISE  BLANKER— RF  GAIN— CW  SWITCH- 
SQUELCH— MIC  GAIN  — DIGITAL  FREQUENCY 
DISPLAY— Hl/LO  POWER  SWITCH— 13.8  VDC  5A 
POSITIVE  OR  NEGATIVE  GROUND. 

See  your  dealer  for  a  demonstration. 
DEALER  INQUIRY  INVITED. 

NEW438to450MHz 
PLL  mobile 
i^3ia  Memory  Scan 

1275  K  GROVE  ST. 
ANAHEIM,  CALIF.  92806     (714)  630^4541 


three  joints  at  the  ends  of 
the  radiating  portion  where 
the  loading  wires  connect 
Single-wire  conductors 
could  have  been  used  just 
as  welL  the  larger  the  bet- 
ter, I  used  what  I  had 
available. 

Care  and  Feeding 

Upon  first  inspection  of 
the  antenna,  I  was  some- 
what alarnried  at  the  magni- 
tude of  the  feedpoint  im- 
pedance. Using  a  noise 
bridge  that  was  capable  of 
measuring  resistance  and 
reactance  through  a  known 
length  of  RG'8  coax,  I  found 
5  Ohms  of  radiation  resis- 
tance. That's  right,  the  swr 
was  10  to  1 .  The  Smith  chart 
in  Fig.  3  shows  the  results  of 
my  measurements. 

The  actual  impedance  of 
the  antenna  may  be  even 
less  than  5  Ohms.  I  did  not 
take  into  account  the  loss 
of  the  teed  line  when  the 
measurements  were  made. 
I  had  predicted  that  the 
radiation  resistance  would 
be  closer  to  10  Ohms,  but 
the  effect  of  nearby  house- 
hold electrical  wiring  and 
the  fact  that  the  antenna 
was  only  about  0.1  wave- 
lengths above  ground  could 
easily  lower  the  impedance. 
Since  the  loading  wires  do 
not  run  at  a90-degree  angle 
to  the  radiating  wire,  a  par- 
tial cancellation  of  the  field 
also  results  in  a  tower 
antenna  impedance.  In  an 
antenna  of  this  type,  a  high 
impedance  is  sure  to  in- 
dicate undesirable  losses. 

There  certainly  are  h^ms 
who  consider  a  10-to-1  swr 
unthinkable.  There  is  salva- 
tion  for  you,  but  first  give 
thought  to  this:  At  4  MHz, 
100  feet  of  RG-8  (or  RG-21 3) 
has  a  loss  of  about  0.3  dB 
and  the  additional  loss 
caused  by  a  10-to-l  swr  is 
1.0  dB.  A  total  of  1.3  dB  or 
about  25%  of  your  power  is 
lost  in  the  coax.  Foam  di- 
electric coax  will  be  about 
1.2  dB,  and  shorter  lengths 
give  proportionately  less 
loss. 


No  one  would  think  of 
trying  to  feed  such  a  mis- 
match directly  from  the 
output  of  his  transmitter. 
Almost  any  of  the  ''univer- 
sal transmatches"  will 
reduce  this  to  an  accept- 
able level. 

The  matching  network  I 
use  is  shown  in  Fig,  4.  The 
capacitors  are  from  old 
ARC-5  equipment.  They  are 
adequate  for  power  levels 
up  to  400  Watts  PEP  or  CW 
input.  By  the  use  of  a  log- 
ging scale  on  the  capacitor 
dials,  I  can  rapidly  QSY  any- 
where within  the  60-meter 
band  and  still  present  a 
50-Ohm  load  to  my  trans- 
mitter 

A  second  method  of 
matching  may  appeal  to 
those  of  you  who  are 
squeamish  about  high  swrs. 
There  are  several  nice  wide- 
band impedance  step-up 
transformers  available  that 
are  designed  for  use  with 
mobile  antennas.  Using  one 
of  them  will  raise  the  im- 
pedance to  nearly  50  Ohms 
so  that  the  main  feedline 
operates  with  a  reasonably 
low  swr.  The  catch  is  that 
this  will  only  allow  opera- 
tion over  a  narrow  band  of 
frequencies,  since  the  an- 
tenna has  a  fairly  high  Q. 

On  the  Air 

lust  because  it  looks  fun- 
ny, it  doesn't  mean  that  it 
works  that  way.  Stations 
report  respectable  signals. 
Comparisons  were  made 
with  one  local  station 
whose  traitsmitter  power  is 
about  3  dB  below  mine.  He 
uses  a  normal  inverted  vee 
about  40  feet  high.  No  per- 
ceptible differences  were 
noted  in  signal  strength, 
both  on  close-in  (30-mile) 
and  longer-haul  {1000-mile) 
paths.  1  found  this  hard  to 
believe  at  first,  too. 
However,  repeated  com- 
parisons and  several 
months  of  successful  oper- 
ation bear  out  the  solid 
reliability  of  this  indoor 
radiator.  ■ 


74    73  Magazine  •  December,  1980 


AUTOMATIC  SWR  &  PEAK  READING 


HF  POWER  METER 
MODEL  APM1H 

Frequency  Coverage: 
[nput  Impedance: 
Power  Range: 
SWR  Range; 
Power  Modes: 
Accuracy: 


^9.95 

1.8 -60  MHz 
50  —  52  ohms 
0-200,  1000,  2000W 
^1  -  10:1 
Average  &  PEP 
±10% 


Power  Requirements:  1 17  VAC  60  Ht 


AUTOMATIC  SWR  St  PEAK  READI 
VHP  POWER  METER 
MODEL  APM'IV         $99.95 

Frequency  Coverage:  50  — 150  MHz 
Input  Impedance:        50  -  53  ohms 


Power  Range: 
SWR  Range: 
Power  Modes: 
Accuracy: 


0  -  20,  200W 
1:1  -^  10:1 
Average  &  PEP 
±10% 


Power  Requirements:  T  1  7  VAC  60  Hz 


FLAT  RESPONSE  SWR  &  POWER  METER 
FOR  HF 
MODEL  PM 2H 

Frequency  Coverage 
Input  impedance: 
Power  Range; 
SWR  Range; 
Accuracy: 


$89.95 

18^  60MHz 

50  -  52  ohms 

0  -  200,  1 000,  2000W 

1:1  -3:1 

±10% 


Povyer  Requirements;  None 


PLAT  RESPONSE  SWR  &  POWER  METER 
FOR  VHF 

$89.95 


MODELPM2V 

Frequency  Coverage 
Input  Impedance: 
Power  Rang«: 
SWR  Range: 
Accuracy; 


50-150  MHz 
50  -  52  ohms 
0  -  20.  200W 
1:1  -  3:1 
±10% 


Power  Requirements:  None 


^HIEMJEl 


SWR  8(  POWER  METER  FOR  HF/VHF 
MODEL  PM3HV         $54.95 

Frequency  Coverage;  3  —  150  MHz 
input  Impedance;         50  —  52  ohms 
Power  Range:  0  -  20,  200,  1000W 

SWR  Hange:  1:1  -5:1 

Accuracy:  ±10% 

Power  Requirements:  12  VOC 
Illuminated  meters  tor  mobile  operator 


Miili 


Manufactured  By: 

AKIGAWA  ELECTRONICS  CORPORATION 

Distritiuted  Exciusivetv  ^T- 

MACAW  ELECTRONICS  INCORPORATED 

P.O.  Box  66,  Carlsbad,  Calif.  92008 

Phone  {714^  -434-1078 

TftfeJt  181743  MACAW  GSBD 


SWR  8t  POWER  METER  FOR  MOBILE 
MODEL  PM'SH  KH^)  $49.95 

MODEL  PM-5V  (VHF)  $49  95 

Frequency  Coverage;  1,8  -  30  MHz  (PM-5H) 

50-  150MHe{PM-5V} 
Input  Impedance:         50  —  52  ohms 
Power  Range:  0  -  20,  200  W ±10% 

Power  Requirements;  12V  DC 
Complete  with  directionat  coupler  unit 


SWR  &  POWER  METER  FOR  HF/VHF 
MODEL  PM^HV         $44.95 
Frequency  Coverage:   3  —  1  50  MHz 
Input  Impedance:         50  —  52  ohms 
Power  Range:  0  -  20.  200,  1000W 

SWR  Range:  1:1  --3:1 

Accuracy:  ±10% 

Power  Requirements:  None 

Velcro  for  mobile  mounting 


MIKE  COMPRESSOR  WITH  LINEAR 

AMPLIFIER 

MODEL  MCLA-1  $89.35 

Compressor  Section 

Frequency  Range;     100  -  10000  Hz 

DtstortJon:  Within  04% 

Linear  Amplifier  SeetJon 

Frequency  Range:     300  —  10000  Hi. 

Gain;  25dB  fl2V) 

Power  Requirements;  9  VDC 


ACTIVE  AUDIO  FILTER 


MODEL  AAF'1 

Filters; 

Center  Frequency 

Shift  Width: 
Input  Impedance; 
Output  Impedance: 
Output  Power: 
Power  Requirements:  9  VDC  160  mA 


$89.95 

Band  Pa ss+ Notch 

200  -  2500  Hz 
8 -600  ohms 
8  ohms 
1 W  max. 


PRESELECTOR 

MODEL  PR-1  $109.95 

Frequency  Coverage:  3  —  30  MHz 


Gain: 

RF  Attenuation: 
Inpuf/Output 

Impedance: 
Relay  Power 

Capability: 


20  dB  at  7  MHz, 

Variable 

^20dB  &  -lOdB 

50  —  75  ohms 

200W  CW 


(Prices  are  suggested  li$t  and  are  subject  to  change  without  notlcej 


Power  Requirements-  1 1 1  VAC  60  Hi 


1^  R'&^der  Service— sse  page  226 


73  Magazine  *  December,  1980    75 


^ 


Sipalciafters  Presents 

Thft  Most  AdvanrBd 

iutomatic  Compnting 

Pftwcr  Meters 
In  Amateur  Radio! 


MODELS  31  and  32* 

Our  portable  Modets  31  and  32  feature 
the  same  slate-of-the-art  technology 
that  is  incorporated  in  their  Big  Brother, 
the  Model  30,  Never  again  will  you  have 
to  bother  with  SWR  "calibrate"  controls 
and  svyitches!  Signatc rafters'  custom 
integrated  circuit  makes  power  and 
SWR  measurement  a  "handsoff "  opera- 
tion by  automatically  computing  SWR. 
The  result  is  unparalleled  accuracy  and 
ease  of  operation. 

FEATURES: 

•  CUSTOM  IC-Computes  SWR  from 
the  level  sensed  on  the  transmission 
line  independent  of  the  power  leveL 
This  analog  corrputer  operates  over 
a  range  of  onfy  one  watt  to  the  full 
scale  of  the  meter  with  un equaled 
accuracy. 

•  RIICGED  TAUT-BAND  METERS- 
Provide  accuracy  and  readability 
that  must  be  seen  to  be  appreciated. 

•  HEAVY  DUTY  CABINETS-Hand- 
some  heavy  duty  metal  cabinets 
Gompiement  virtually  every  trans- 
ceiver on  the  market  today. 

•  TWO  MODES-PEAK  OR  AVER 

AGE— The  amateur  may  choose  be- 
tween either  peak  or  average  power 
readings. 

•  POWER  REQIJIREMENTS-Oue  to 
the  advanced  low  current  design, 
battery  life  is  truly  outstanding,  mak- 
ing this  meter  e  natural  for  portable 
or  field  day  operation,  Uses  standard 
9  volt  battery  or  120V  AC  with  op- 
tional AC  adaptor 

•  An  RACTIVE 
AFFORDABLE  PRICING 
*Model31A(0to200w) 

31 B  {0  to  20w) 

-only  $149X0 

Model  32A  (0  to  200w,  0  to  2000w) 
32B  (0  to  20w. 
0  to  200w) 

, only  $169.00 

SIGNALCRAFTERS,  INC/ 

5460  BUENA  VISTA  DRIVE 

SHAWNEE  MISSION.  KANSAS 66205 
9ia/262  6565;  TELEX  42-4171 

All  SipnaEcrafters  prdducts  ar&  designed,  engineered, 
and  prodix^ed  in  (he  U.S. A  Pnces  jncfude  sTiippirtg  to  3II 
U.S.A.  ViSA  and  Master  Charge  accs-pt&d  KansaB  Resl- 
den:!s  pi  Base  add  3V!.-  percent 


f^66 


SCANNERS: 

Introducing  a  scanner  tor  the  ICOM  1C2AT. 

KENWCX)DI1IMOO«k  ,TR7600,&nt7625 , 

TEMfKD  c^>  ^  A^^  ^)  ,KDK  2015R,ICDK  20t6k, 

ICOM  IC22S,  j||IDLAND13'510ja'513, 

CLEGGFM  2d,  COMITONDC  ,YA£SU  FT227R 


•  AEI}  zml'mti  to  extend  Its  line  oF  au^litv  icinn^n. 

9  All  ftl  iiU\  Jtannerj,  m  custom  deiigncd  lo  intldll  completelif  inside  qF  !heir 
respective  rigi, 

•  lititiElitiwi  is  im^t.  Unlike  olNer  cDrnpetilire  QtaiMh  i\\  AED  tcanncn  wt 
ttciigMd  10  Ihat  11  ii  toUliif  wnecesstfrt  (o  tuf  m  wi^is  Mk  your  ng  durins 
intlilbllon 

•  All  PXi.i  are  iiili(-screeii«il  md  lin  pl«ttd  lor  caiiff  dnd  mtt  iFlective 
sgld«rlng. 

•  ]\\i  kil  comes  compltle  witt  all  parli  nA  i  delaifed  iniUucFbn  manyal  in- 
cfydiiig  ^dieitislki. 

•  In  the  lumtt  OFF  mU  !he  li^  aperdlei  narmalli.  In  Ihe  Kmm  OH  mode 
he  scdFiner  Ic^ki  m  an  Qccupied  frtquenct.  paniiei  tor  i  pfeict  li^me  iibout  3 
uc]  J[*d  Iben  mmm  scanning  leice^t  W. 

m  Ihe  IrequencY  Wm  ii:d[intd  is  (tii^l^red  on  Ihe  digjid  readDyi  {ami  72S 
vein    and  lempaj. 

•  Ihi)  (^ivei  ^w  \\k  abiEity  t«  ea^eidrop  ^31  wv  the  band  wilhoLl  lih'm  a 
linQBr.  When  ifou  liear  iD^nettiing  Interestiti^,  m  lEip  (be  ivttch  to  tfit  lOCK 
mode  m6  Ihe  ri^  n  mi)  tci  trans:[nii. 

KIT  PRICE 39.95 

PREASSEMBLfD,  REG. ..  59.95 
SPECIAL,  NOW 49.95 


lOvMETER  FM 

-IHE  NEM^  FRONTIER 

1he>lED  FM  ADAPTER  is  no»^  available 

4lfct  iEP  t^9^J  cDPirni}  iiiinnf  HP  Irinicerr^r;  b  Ithi^niil  mi  10  fHlvr  FK. 

•  T«  VS4  ihe  uJi^rcf  tw  we  jtt^wti  Id  lUfi  in  Hf  ^St  iTiiifCHifit  hhI  4  7  H  fll 
tHviniier  k  <rect4fer 

■  Dit  AED  kif  {Qflinh  dI  !  P.C.  bwiti.  hlti  boirds  ire  ^fned  14  EiF  wiiriJT  Histii  row  If 
rig.  (Eich  tuafd  mtisurn  1*^ .  iCT.) 

•  One  bt«d  3«rTK  it  Ihe  PoduJi^  «ii^di  FH"s  1  w  iinl-in«  Hf  iriiuiiiB'i  VfO 

•  Tht  tHa^ld  bHfli  rf  a  wpth  idiolir  vhich  cimrirti  }ifm  Hf  (rmtEHri ri  l.f  Id  a  IN  Fre- 
qiMfitT.  Thh  will  ilbo*  iwi  Id  FiEini  noise  hM  lOH;  FH  on  fvttr  IH  Irimnnr 

•  Dill  jn^ilinliofi  [«i  h  diiiMKJ  wl  itie  sti^ll  t^Elch  mtl^i  «ith  1lk(  hJI. 

«*  t!i(  kil  cEHfi  cMpJiti  vfi  111  ftiH  MUt  a  kt^M  imlruclm  maniHl  [frriiil  iwl  m- 

ClMlMl) 


HF  niG 


MIKE  WPtlT 

w 


A£0  RiC  W  Ri'^ 


DEMOWJUTCD  FM 


l^ 


AHT  IftPtn 


LFl£€EIVE» 


/\ 


TO-CAtneflflTE 

era  vfoj 


M0LK.Jt.A,TOft  WItH 
ADjUSTA-QtEGAIh 
t  DEVIAflC^N 


KTT  PRICE 39.95 

PREASSEMBIfD 59.95 


Tempo  series  and  IC2AT  pre  ass  ambled  only 


SPECIAL,  NOW 


:tlt-*l*-*t«i 


49.95 


.3  ilED  ELECTRONICS 

750  LUCEFINE  RD„  SUITE  12D    DEPTA 

MONTREAU  QUEBEC,  CANADA  H^n  2H6 

TEL.  51#7a7-7293 


IKCLUK  SI  SO  FOR 
POSTAGE  AHD  HAHDIING  PER  IIEH 


The  UDT  170 


^m 


The  SMART  TO  for  RTTY  &  MORSE 

The  GDT  170Gniversa!  Data  Transceiver  will  instantly  convert  any 
ASCII  or  Baudot  teletype  or  video  ternninal  Into  a  multiple  baud  rate 
data  transceiver  for  ASCII,  Baudot  or  Morse  operation.  It  features  .., 


'  170/850  HZ  Shift 

•  Dual  6  pole  active  filters  for  weak 
signal  operation 

•  ASCII/Baudot  Regeneration  with 
nnukiple  baud  rates 

•  CW  Auto  Ident  (optional) 

•  1  -1 50  WPM  Morse  with  Auto-track 

Price,  Complete  ~ 

and  Assembled  $^ 


•  Computes  &  Displays  WPM  copy 
rate  &  Buffer  Status 

*  Selectable  line  length  from  40  to  80 
characters 

'  Metaf  Enclosure  12"x7  l/4"x3  1/2" 

For  more  Informatign  write  or  phone 

»XIT€X  CORP 

9861  Chartwell  Drive 
Dallas,  Texas  75243 
(214)349-^2490 


Pnc«  subject  to  change  wKhoui  notice 


76     73  Magazine  •  December,  1980 


APPLE^  Owners 


CW/RTTY 


^      'it!L 


m-  M. 


FEATURES 

~  Send*  flec^ve  MORSE  BAUDOT  ASCM 
Connects  fo  AP'PLE  game  I  O  pofi 

U^je$  |>mltm  PLt  CM  «iilerna<  Tu 
rnciadesnafdwiire  cassien^sft  manual 
(/Vo'd  Of  tented  EdifQr 


APPLE  IS  0  ftcoflniied  nad^nwn  ^  APPiE  CO«RJTC«. 

Wrile  or  call  lot  complete  catalog 


ln$tan)  B^eali  op^'ation  — pitsetve  lype-anead  &iitfef 

e4gm  mes-^geTiernQries  — 255criaf  ea 

Auto  Kansminer  coni»oi  —  **TT 

OidCti«  Beotay  CassetteSaw*  CWIDiRTTYo-ni^i 

PanooT^  P'^tTice  Beacqn  change  &p^acmgiMm&e{?iniiy^ 

CA650  «fi  cab.nei  S2S9 

TA  SSQ  FSD-1  aceiwe  liiiei  RTTr  demodyiaiof 

)tf  L  1  ifal  confroJJea  AFSH  and  AC  DO*er  siif^pty 

I n si  a( »e<j  in  C A^^  i  assern pi^d    te &t ed <  $4§S. 

AGSOOaddsdiskbas^efTY  roCAoSO    TA650SS0 


ICSJnc 


1 125  N.  Golden  Stale  Blvd.  /  Suite  G 
Turlock,  CA  95380  (S)  ^4^ 

(209)  667-2888  /  634-8888      califorriK]  residents  add  6%  mn 
W0  flf«  BMperiBficing  tetephonB  difficutths,  pi«as«  keep  trying. 


TRS-80/RTTY 

The  Crooning  Touch 

ROM- 1 1 6 

Ainatovr  RTTT  Op^rtifflnfi  Syftfam 


Supporti     any     B-level     imtmi 

Crmt«r  or  m<id*nn  *  Baud  rat* 
«yboard  ieftcfabi*  *  Ettpaniion  In- 
teHFocf  not  r«quir*d  for  operation  of 
mmrml  printer  or  mod«m« 


*    BUFFERS; 

Pre -typed 
poiuDle.    * 


7.SK  Main  Ibx^  buHer  * 
rne^i^gei  up  to  ?  .%K 
2-5K   a*n«rai    purpote   btif-^ 


•       AUTOMATIC 
lloft/end  til  t^th 


CW   ID:        At       thi 

trtinfmiffiQn    "    Everi 


•   MODES: 
CW  - 


RTTY   tASCII  Of  BAUOOTJ 


•  REAL-TIME   CLOCK:    24    hour   clodi    ' 
Automotic  updating    '    Time  ditploy   in- 
cludes day,  month  and  yeor, 

•  SPLIT-SCREEN  VIDEO;  1  2  lines  receive 
text  '  3  !m»  transmit  teitl  or  pre-lypi- 
ng  a  message  *  1  line  ditplay^  r»al- 
Hme  dock  *  Statut  ditplayed  con" 
tinuously  *   Word^wrappmg  - 

•  TWO  SEItlAL  PORTS  PROVIDED:  Port 
"A'"  -interfaces  to  tnlernol  or  externol 
terminal  unit  *  RS-232,  TTL  ond  60 
ma.    '    ASCII /flAUCK>T    * 


TO  minutoi  *  Provtsion  lor  quick  breot 
{no  ID}. 

•  TRANSMITTER  CONTROL    Transmitter 

turns          Oh  "^  off  automatrcaMy          via 

software  control  *  Provitions  mode  for 
quick  break- 

•  SOFTWARE  PROVIDED:  2  RTTY  Pro- 
grami  (Cassette/ Disk  version)  ' 
ASCII /BAUDOT  Driver  routines  [permits 
use  of  "LLJST'^  and  '*LPRINT'^  com- 
mands from  bask)  *  CW  send /receive 
program. 

•  HARDWARE  REOUI»£MEKTS:  TRS~80 
with  16K  RAM  *  EMternal  f«rmindl  unit 
recommended  (flesher  TU-170,  ST-6 
#lc)  •  AFSK'FSK  unit. 


16 


CBOUfl 

nicroPiDducts 


INTRODUCTORY 
PRICE 


$300 

l«u  coJ^ne* 


R  O.  Sojr  992 

AiofyiviMe,  Wo*hif%gf&n  9$ 270 

206-659-4279  /  206-6S9-9512 

*A  Trademark  of  The  Tandy  Corp 


Hl-Q  BALUN 


For  dpoies  yag^,  nverted 
vees  &  doublefls 

Ftepiaces  ceni^  nstMator 
'  Puts  power  m  afl4enna 
Broadband)^  3-40  MHz 
Small  ItgtKweidtit  and 
weaiheffjroot 

'  1  t  Impedance  raiio 
'  For  fun  legal  power  and  rtiofe 
Hetps  elimiriaie  TV  I 

■Wirh  SO  239  conned  or 

$10.95 

HI'Q  ANTENNA 

INSULATOR 


Ml-Q 

Oalun 


9-  ^ 


--% 


Smafl  rugged  ligrii«eighl 
weathierprool 

Replaces  o^nt^  msulalor 

Handles  ixM  legal  power 
afld  more 

$5.95  ^f*^  ^  ^^*  connector 

Hl-Q  ANTENNA 
END  INSULATORS 

Rugged,  liglitwelghl.  in)ec- 
tfon  molded  of  top  quality 
maiertal.  witti  hfgh  dietec- 
tnc  qualities  end  excellent 
weatlierabiHty.  End  insula- 
tors are  conslructed   In  a 
spiral  unending  fashion  to 
pennit  wfndmg  of  loading 
colls  Of  partial  windtng  lor 
tuned  Iraps. 
May  De  used  io' 
*Guyf  wTfe  sir  am  msulalors 
•  End  ot  ceniet  «nsulaiors  lor 
antemias 

kConviiClion  oi  amenna  iDad- 
tno  rrfii^  rst  mifnifwjnfl  traps 


T  *4.95 


UOOEL 
OffHMt 

iikNQ^           LEHI3TH 

PftlCE  WVtH 
HJ-O  BALUli 

W\JH  H1-0 

Ce«T£B 

INSULATOR 

r>m 

80.75 

i;W 

$28.95 

$2495 

D-40 

40.15 

m 

25,95 

21.95 

D20 

20 

33 

24-95 

2D.95 

D-1S 

15 

22 

23.96 

19.95 

OlO 

10 

16 

32,96 

18,95 

Shontnvd  dtpoiti 

SD-80 

60,75 

% 

3195 

27.95 

SD-AQ 

40 

45 

2&.95 

24.K 

Parslrkl  dlpoi 

n 

pc^eoio 

80,40.20.10.15 

130 

39^ 

35.95 

PCMOtO 

40.20. 10,1 5 

66 

33  95 

29.95 

po-acMo 

80.40,15 

1^ 

35.95 

31, K 

PO-4020 

40.20.15 

m 

29.95 

25.95 

Oven*  thonftn***     only  HHt»  to  i4Ckjdvd  in  ID  rmo^^ 

sso 

80,75 

$11.96  m 

&40 

40 

SlOSSpr 

All  antennas  are  complete  with  a  HI  O  Balun  or  Ht-Q 
Anienna  Ceni^r  insylator.  Ho,  14  anienna  wfre,  cer- 
amic insulators.  100  nylon  antenna  support  rope  {SO 
models  only  50J  raled  f Of  full  legal  power  Antennas 
may  be  u&^  as  an  inverted  V  and  mey  also  be  used 
by  MARS  or  SWLs. 


Antenna  acoessorfes— available  with  antenna  orders 
Nylon  guy  rope  450#  lest  100  teei  S3.49 

Ceramic  {Dogbone  Type}  antenna  Insulators      .70  pr 
SO-239  coax  connedors  55 


All  prices  am  postpaid  USA  49 
Av^latale  al  your  favorite  dealw  or  or^dof  direct  from 


%^^mm  DeaJer  Inquiri^es  Inviled 

Gorden 
Engineering 

BOX  21305,  S,  EUCLID,  OHrO  44121 


f^  fleadsf  Service — s&e  page  226 


73  Magazine  •  December,  1980    77 


$OmL  EVEHTS 


Listings  in  this  column  are 
provided  free  of  charge  on  a 
space^avattabie  basis.  The 
foUowmg  tnformatton  should  be 
included  in  every  anriounce- 
ment:  sponsor,  event,  date, 
tirr^e.  pi  ace,  city,  state,  admiS' 
sior*  charge  (if  any),  features, 
iaikin  freguencieSf  and  the 
riame  of  whom  to  contact  for 
further  information.  Announce- 
ments must  be  received  two 
months  prior  to  the  month  in 
which  the  event  takes  place. 
They  should  be  sent  dtrectly  to 
Editoriai  Offices,  73  Magazine, 
Pine  Street,  Peterborough  NH 
03458,  Attn:  Soaaf  Events. 


FARIBAULT  MN 
DEC  6 

The  Handi-Ham  System  will 
hoid  its  annual  winter  hamfest 
on  Saturday,  December  6,  1980, 
at  the  Eagles  Club,  FaribauH 
MN,  There  will  be  a  flea  market, 
a  dinner  at  noon,  a  program,  and 
a  prize  drawing 


OAK  PARK  Ml 
JAN  11 

The  Oak  Park  ARC  will  hord  its 
annual  indoor  Swap  &  Shop  on 
January  11,  1981.  at  the  Oak 
Park  High  School,  Oak  Park 
Boulevard  (SV?  miles  west  of 
Coolidge  Highway).  Oak  Park 
Ml.  Doors  will  be  open  from  8:00 
am  to  3:00  pm  and  admission  is 
S2.00  per  person.  Features  will 
Include  an  ARRL  table,  a  door 
prize,  a  YLRL  table,  food,  re- 
freshments, and  free  parking, 
Talk-In  on  146.04/.64  and  146.52. 
For  more  information,  send  an 
SASE  to  Rob  Numerick,  23737 
Couzens,  Hazel  Park  Ml  48030, 
orcall(313>-398<3ie9. 

CHESTERREIOVA 
JAN  11 

The  Richmond  Amateur  Tele- 
communications Society  will 
hold  Frostfest  1981  on  Sunday. 
January  1 1, 1981,  at  the  Chester- 


field  County  Fairgrounds. 
Cheslerfieid  VA,  from 8:00  am  to 
4:00  pm.  New  and  large  facilities 
include  spacious  aisles,  and 
plenty  of  on-site  parking,  with 
Charter  buses  welcome.  Admts- 
sion  is  S3.00  for  each  four-foot* 
long  flea  market  table,  and  $2.00 
for  each  tarlgating  vehicle. 
Features  will  include  commer- 
cial exhibitors,  a  flea  market,  an 
auction,  and  prizes  consistmg 
ol  a  color  TV.  a  Bird  Wattmeter 
with  slug,  a  digital  VOM,  and 
many  more.  Talk-in  on  146.34/.94 
and  146.28/  .88.  For  further  infor^ 
mation,  contact  the  Richmond 
Amateur  Telecommunications 
Society,  PO  Box  1070.  Rich- 
mond VA  23208. 

LIVONIA  Ml 
FEB  22 

The  Livonia  Amateur  Radio 
Club  will  hold  its  11th  annual 
LARC  Swap  n  Shop  on  Sunday. 
February  22,  1981,  from  8:00  am 
to  4:00  pm.  at  Churchill  High 
School,  Livonia  Ml.  There  will  be 
plenty  of  tables  available.  Other 
features  include  door  prizes, 
refreshments,  and  free  parking. 
Talkm  on  146.52.  For  further  in- 
formation, send  an  SASBE  (4"  x 


9")  to  Neil  Coffin  WA8GWL,  c/o 
Livonia  Amateur  Radio  Club»  PO 
Box  2111,  Livonia  Ml  48150, 

VERO  BEACH  FL 
FEB  21-22 

The  Treasure  Coast  Hamfest 
well  be  held  on  February  21-22, 
1981,  at  the  Vero  Beach  Commu- 
nity Center.  Admission  Is  $3.00 
per  family,  in  advance,  and  S4.00 
at  the  door  Features  wtll  In- 
clude prizes,  drawings,  and  a 
OCWA  luncheon-  Talknn  on 
146.13/73, 146.52/.52.  14$.04/.64, 
and  222.34/223.94.  For  informa- 
tton,  write  PO  Box  3086.  Beach 
Station,  Vero  Beach  FL  32960. 

DAVENPORT  lA 
MAR1 

The  Davenport  Radio  Ama- 
teur Club  will  hold  its  tenth  an- 
nual hamfest  on  Sunday,  March 
1,  1981,  at  the  Davenport 
Masonic  Temple,  Highway  61 
(Brady  Street!  and  7lh  Street. 
Davenport  I  A.  from  8:00  am  to 
4:00  pm.  Tickets  are  S2.00  in  ad- 
vance and  S3.Q0  at  the  door.  For 
advance  tickets  and  table  reser- 
vaSions,  write  Dave  Johannsen 
WBOFBP,  2131  Myrtle.  Daven- 
port lA  52804. 


encounter 


Dateline  Dayton  Hamvention  . . . 

To  (tomofiitrate  the  selectivity  of  our  Msrfc  3CR  repeater  we  keyed  a 
trantfnitter  1 5  KHz  off  frequency  and  »et  It  directly  againat  the  receiver 
Input  Our  Mark  3CR  didn't  even  notice  the  close  encounter. 


Sure  the  Mark  3CR  can  withstand  severe  interference,  * 
ft  uses  both  crystal  filtering  and  double  conversion. 
And  that's  just  the  beginning.  Its  performance  contin- 
ues with  a  transnnjtter  that  meets  commercial  specs 
plus  a  microprocessor  controller  that  gives  you  39 
functions  and  13  Morse  messages.  For  peak  perform- 
ance have  your  own  close  encounter  with  a  Mark  SCR  / 
Repeater  or  Mark  3C  Controller. 


call  or  write  for  specifications    *^^^ 
MICRO  CONTROL  SPECIALTIES 
23  Elm  Park.  Groveland,  Ma.  01634 

(617)  372-3442 


78     73  Magaitne  •  December,  1980 


HAM  HELP 


I  need  schematics^owner's 
manual  for  an  Eico  model  625 
tube  tester.  I  will  pay  the  post- 
age, copy,  and  return  all  materi- 
al. 

Also,  I  need  any  modifica- 
tions for  the  Globe  V-10  vfo.  I  re- 
cently purchased  one  at  a  ham- 
test  and  the  6CB6  plate  circuit 
doesn't  match  the  schematics. 
It  has  a  very  low  output  (approx- 
imately 0.5  V  p-p). 

Vvn  awaiting  my  Novice  ticket; 
that's  why  there's  no  call  in  my 
address. 

Tim  Cook 

453e  Knoll  Drive 

WoodbridgeVA  22193 

I  recently  obtained  an  Allied 
SX-190  reciever  at  a  local  ham- 
fest,  but  \  did  not  receive  an  op- 
erating manual.  If  anyone  could 
supply  me  with  a  manual  or  a 
xerox  copy  of  one  (I  believe  the 
manual  for  the  AX-190  ham  re- 
CBfver  is  the  same),  I  would  be 
happy  to  pay  for  it.  The  receivers 
were  produced  by  Allied/Radio 
Shack  in  the  early  70s.  Thanks! 

Gary  Toncre  WA4FYZ 

13764  SW  54th  Lane 

Miami  FL  33175 

I  would  be  interested  in  com- 
municating with  anyone  who 
has  used  the  Heathkit  SB  610 
and  SB'620  at  i-f  frequencies 
higher  than  6  MHz.  For  example, 


the  Kenwood  TS-820S  has  an  if 
output  at  8.83  MHz,  and  I  would 
be  Interested  in  any  modifica- 
tion which  will  accommodate 
the  higher  frequency. 

J.O.  Dickinson 

1408  Monmouth  Court  West 

Richmond  VA  23233 

I'm  looking  for  a  schematic  or 
instruction  manual  for  a  Knight 
model  KG-642-A  ultrasonic  in- 
trusion alarm,  circa  1970,  and  a 
schematic  for  a  function  gener- 
ator using  the  XR'205  chip.  I 
would  be  happy  to  pay  for  an 
original  or  a  copy.  Thanks. 

Gene  Smarte  WB6T0V 

Nubanusit  Road 

Hancock  NH  03449 

1  need  circuit  diagrams  and/or 
books,  as  well  as  information  on 
a  vfo  and  mods,  for  a  Conar  400 
transmitter  and  500  receiver.  I 
will  pay  for  copies. 

Nate  Bushnell  KAODGN 

7175  S.Grant  St. 

Littleton  CO  80122 

{303)-794-6956 

)  need  all  the  information  I  can 
get  on  converting  a  J.C, 
Penney's  Pinto  SSB  rig  to  10m. 

John  Lynn 
1456  Cheyenne  Street 

W.  Fargo  NO  58078 


SIGNAL  GENERATORS 
OVERHAULED  AND  LAB  CALIBRATED 


AN/(jRM-25,  RANG€  lO  KHZ  THRU  50  MHZ,  AM,  CW,  MODULATION  400  &  \  KHZ,  RF 
OUTPUT  0-2V  OR  O-.l  V,  PRECISION  50  OHM  STOP  ARENUATOR,  PERFECT  FOR  AMA 
TEUR  AIRCRAFT.  MARINE/ORIAB  US€, . . . , S285.O0 

TS-510/U  RANGE  TO  MHZ  THRU  420  MHZ  ODIPUT  VOLTAGE  .5V  TO  IV,  MODULATION 

400,  looo  HZ,  AM.  CW  OR  PULSE , ., - :. .  . . , , ,  385.00 

TS-497/URR.  RANGE  2  MHZ  THRU  50  MHZ,  OUIPUT  VOLTAGE  O^TOO.OOO  MV.  400 
CYCLE  MODULAIION,  AM/CW  MIUTARY  VERStON  Of  THE  MEASUREMENTS  MODEL 

SO 225,0O 

SG-3/U  FM  RANGE  50THRU  400  MHZ  IN  3  BANDS,  METERED  RF  OUTPUT  O-l  V,  MbTtRlD 
FM  DEVIATION  0-^50  KHZ,  VARIABLE  50  OHM  AnENUATOR,  EXCELLENT  FOR  HLGHgAND 

RADIOS, 386,00 

SG-12/U  FM  RANGE  20  MHZ  THRU  lOO  MHZ  IN  5  RANGES,  METERED  OUTPUT  AND  DEVI- 
ATION, PERFECT  FOR  LOW  BAND  FM  MILITARY  AND  COMMERCIAL  J^ADlOS. .  j  55  qq 

MEASUREMENTS  560  FM  RANG€  25  THRU  54  MHZ,  \30  THRU  174  MHZ,  400  THRU  4/U 
MHZ  AND  a^  MHZ  IN  6  BANDS,  VARJARE  OLJTPUT  100,000  MV  TO  O  1  MV,  lOOO 
CYCLE  MOOULATfON,  VARIABLE  DEVIATION  0-16  KCS,  METERED  OUTPUT  AND  DtVlA^ 
TION.  A  FINE  COMMERCIAL  GENERATOR 45Q  qq 

SG  13/U  VOR/ILS,  RANGE  108  THRU  1359  MHZ  AND  329.3  TO  335  MHZ,  OUTPUT  SfG- 
NALS  INCLUDE  VOR,  IOC.  GLIDESCOPE  AND  lOOO  CPS,  OPERATES  FROM  H5V,  60HZ, 
SAME  AS  COLLINS  479T  2,  PERFECT  TO  REPAIR  AIRCRAFT  RADIOS 285  OO 

TS^4ie  URM-49,  RANGE  400  THRU  TOOO  MHZ,  AM,  CW.  OR  PULSE.  METERED  OUTT^JT, 

PRECISION  ATTENUATOR. _;,...,.. . .  ;;i^.-^■. . . , .  .-,;-■.,  ■  -  ■  ]65  QQ 

TS-1379/U  SPECTRUM  ANALYZIR.  RANGE  2  THRU  31.5  MHZ.  5"  CRT  DESPLftV  USED  TO  DE- 
TERMINE RESIDUAL  CARRIER  LEVEL,  THE  LEVEL  OF  HUM  SIDEBANDS.  AND  INTERMODULA- 
TfON  DISTORTION,  PERFECT  FOR  TESTING  SSB  TRANSMIHER.  USED  ON  ALL  NAVY  COMM 

SHOPS - , .  ■  ■ ,.  -  -  375.00 

FOB  OnO,  N.C.  SATISFACTION  GUARANTEED  OR  MONEY  REFUNDED.  SEND  CHECK.  VISA 
OR  M 'C 

'    ^  PHONE  BILL  SLEP  704-524^  7519.  ^367 


J.       \L       .  ,.     — \^ 

.X.  n  V        '  t  \K'\ 


Electronic 
Distributors 


Step  Electronics  companii 

p.  O.  BOX  100,  HWY  441,  DEPT.  73 
OnO.  NORTH  CAROLINA  28763 


I  need  operating  manuals  and 
schematics  for  a  Collins  75A 
transmitter  and  75A-2  receiver. 
Can  someone  help?  1  will  pay  for 
copms. 

Bill  Morehouse 

PO  Box  214 

Waukesha  Wl  S3187 


Does  anyone  have  any  infor- 
mation or  a  schematic  for  a 
Motorola  T71GJT-1100?  i  will 
buy  a  manual  for  the  above  or 
pay  for  a  copy.  Thank  you. 

Fred  Martin 

16  Reid  Street 

South  RiverfSlJ  08682 


thb  publication 

is  Qvoiloble  in 
microform 


.ul-ll 


tifiti 


_.y^^-* 


University  Microfilms  International 


aOO  North  Zeeb  Road 

Dept.  PR. 

Ann  Arbor,  Ml  48106 

U.S.A. 


18  Bedford  Row 
Dept  PR. 
London,  WC1R4EJ 
EnQiand 


:  StATtMENT  OF  OWNEB&H  If,  M  ifhNflG  EM  E  NT  A  NG  G  IffCULAT^ON  |  Huq  Idf  Ed  tJy  39 
U.'S.C.  3BQ5)  1.  Tint  or  pijtiNcatiDin.  73  Maqaimi.  Z  Oale  q\  \\\m%  Ocl  i.  19B& 
3  "Fii^g^ni^y  [>rr&^ijK.  MrjrTthty  A  Ni>  cl  i9:&u«&  piibJisfted  anivuali^  IE.  &  Annual 
sutEDriplion  price, ^^i.ffl)  *.  L<Jcatlon  ol  IfnownoHica  ol  publncsllcn  jSiTflut  Cily. 
Cflumy^.  51*1*  *n(3  ZIP  Ccidei  iNol  pnnlersl,  &D  Pme  Streal,  F'trerOorough.  HiUstwtc 
OouJitv,  f+.H  M^Se.  5.  LoCiitton  o1  (ftc  MiJ^J^uaMer-s  oi  y#nefal  Uu&irii&a  orfi-t-«a  of 
the  pu&Nsher&lNot  pi'i<v(Br*3.  90  Pi  he  Sfte^H.  Prtli^i-ti^jfftwah.  Hillabcjft^i  Coufil^'.  M.H 
€3454. 6.  Namaa  and  comp  leSa-  addresses  ol  pu  hil-sher.  ^iJi(&r  ^rwJ  in*  n^q\ii^  aniiof : 
PubitBhflf  iNanofl  and  Aadf&sa).  Wavn*  Green,  Petertjorouflh.  MH  OSflOe.  Edftpf 
|M;irrvK  ^hd  A^df^a^i,  lAldynr  Gr^^^n,  P#lerbciroLjgh,  N  H  0^^  Managing  EdttrM 
\Uame:  artd  AddrMS?.  Jach  BurineH.  i2'C  Granrtg  SI.  PetcsD&rcHJuh  MH  03468. 
7  DwrM-r  ^ir  i>wria£t  t^y  a  corpofalior^.  He  name  and  adCraas  intj.&r  t?e  &[Ble<1  ai^  al^o 
Imin^^iateEy  iher^vncter  th«  nanvB-  and  addrc-scps-  of  aiocKrihcildarE  owriing  v  *«3^- 
\tvQ  1  ptibiiT\\  i^\  mtits.  (i\  \Q\i\  amehjm  at  slock,  tl  iiol  ownad  by  a  -cpriHKattar^,  \h» 
n^me^  and  adcrrasses  oF  ihe  mdivjdual  owners  Tkr&t  beqiven.  \t  own^d-by  ap^rlmAr- 
afilp  0*  older  uninGorporated^irm.  lis- name  and  3ddT^E&,  as^^iLas  that  uf  e*ch  Indl- 
■viduai  mual  be  giMtn.  It  Iha  publication  is  jjublfshas  ty  a  n<jnprcfHi  t>fa!inij:BHos],  H^ 
TlBinA^iirl  ac>fi^#s.^;  m'.i!!:t  b^  ■El^t^d  |  M?^«,  73,  Ini::.,  Pai^bntiXtQh  N  M  DJ^SS.  W^yn? 
flfflan,  PaSa^borEHign .  N.  H .  03*!ili.  8    Ktvo wn^  bond('£jWa?'&,  rTiy/i;aij^ga«i  *hf|  octMJf  seJ 

.  cwMly  haldera  owning  or  holding  1  laercent  or  mora  of  tt>1al  am(>unt  of  ba»ds.  mort- 
<g«{}4i^ or  al ht-j  ^j^grl^^iiG;  111  Ih^e  Af6  tKihe,  schSlttte^  Nama,  e\aiv&..U.  for  cornpl^ticin' 
^y  ni3<nprQJili>fg«ni,j3]jOH!iaLi1linEi£«d  tr^iTiAil  Al  Special  rstas 4^fi<;] Ion  132.1  ZZ,  t'SMi 
Thfr  purpose.  Fu'(it;tipnan^>  iKmpEOl^E  si^luii-or  t^la  orQ^ni^^tit^n  and  th^^EeiT>p1  slat- 
us  lor  Federal  inccume-  last  purposes  (ty^Bck  one?  Ny(  applncjitalc  lO  EKinni  and  ha 
lufR  t^f  sifnySaliLiri  i^'i  Avefage  Ho  copies  aach  i&sua  during  z^racading  l^nnonlhs. 
(Y|  Actual  No,  topie^  yf  single  iss^b  p-whJi&hct]  near^sl  to  I  lima  dilt  A.  Totai  No  Ql 
copfea  printed  jMot  Press  ftunj  iXj.  76,S53  lY)  73.6W-  B  P^id-tHfCMliffflrt  1  5-Al*ft 
Ihrougb  daalars  and  canri^ra,  s.trael  vendors  a^  rcunlef  aala^.  (Kl  i'0,77Sii;Y|'  9,950. 

;'^  MJtII  subscriptlona  fK)  BD.t^Z  (Yl  55,2^9'  C.  Total  paid  circulation  (SLini  ol  1QBI 

'.ijtICJ  1Q^3)  {X|[  72,91 1  \Ti  e&,Z29-  t?    F^raa  dlarnbutiort  by  mail,  -i^arrle''  or  other  maana. 

:  tfjv^pl,^^.4^<:jmpllman1ary,  and  oth«4  Iraacop^a^i  fX^  Z^  rV)^Q4.  E.  ToUa^  dhstributhon 
fBum  pt  C  and  DJ  jXji  71.i:3t  \y\  65.5i3.  F  COfii^s  ^iiii  itisliinulfsd  1  QIFiinr  uso.  tell 
tmiiu  u'rtacecujriLed,  spoiled  aheir  pranlirrfl  \f.'i  l.D^d  iv)  i.D4I0.  2.  Meturns  U^om  nswa 
^fl^jnis  |X)  4.7K  iV|  7.14?.  Q  Tcjtal  rSym  oF  £_  Fi  d4id  2— aticuflo  equdi  rvet  ptesa  jdfi 
ehown  m  Aj  i  X.]  7(5.953  iVj  73,695.  1 1  I  cfrtdfy  Lh*t  th*  si  atemirnis  m&ac  by  me  atmn^ 
afaoorfBC:!  and  ccMnpr«ta.  S'gnaiura  and  Eitleol  edilor,  pub^Lshef.  bu&in«&s>nanaggr. 
Gn  OH'ne^   DeOra  Soudrieau.  Buatneaa  Mariager 


MICROWAVE 


DOUfi    CONVERTER    POWER    SUPPLf    KIT 
AIJ    Parts    included* 
QiMl  i  tj'    Cjse^    ?50    ma 
regulated,    very   detailed 
■instruction^^    two   incidel  s- 
works    vnth    all    down   converters 
TU-8  B-12   VIK 

TU-1?      1?-16    VDd 


559,95 


Introduction   t.o'  i   ^Hz   S.tud;^ 

Couiifse+    included    a    gtjaH t 


S4  9,95 


^ 


dawn    converter    kit>    detailed 
$  t  e  p ' b^ - s  t  e  p    instructions. 
Requires   3-12V 

FREE    BONUS:       Microwave    rtntqnna 
CaokbDok 

HICROVlAVf:    ANTESWA    COOKBOOK 

Inf  c^'ritiat  ioifi'  'flft   SMP    products 
J2.CI0    handlintj    cliarge, 
Maryland    residenLs    atld    sales    taK 
VISA    and   Haster   Charge  accepted. 


SI  0.00 
5ASF 


S  M  P  1-^376 

Post  Uffice  Rox  2050 

G5  i  thersburg  ^    Mil  ry  land      ?T]7f50 

(3G1  )    258-5150 


K^  Readef  Servic&^see  page  226 


73  Magazine  •  December,  1980     ?9 


One-Stap  Component  Center  ^ 

This  is  a  partial  listing  of  over  500  items 
available  from  authorized  Jim-pak  Distributors: 


fflWf 

TTL        ?%i 

7400  ......  2A85        7430  ,   .   .  . 

*  ,     .as 

M02 

■      >■■-■ 

.   2/.85        7493  _   .   , 

.  ,       .85 

7404 

.B 

.   2/,85        74L0O.   .   .  , 

.   ,   .2.25 

740e  . 

i 

.2/L19        74109-.   .   .  . 

.  ,2/1.19 

7407 

■ 

.2/1.19       7412K  .   .  , 

.  .      .69 

7408 

* 

.  2/.89       74123.  .   . 

.  .       .99 

7410 

.   2/.Bb        74150.  ,   .  . 

.  ,   a.95 

7414 

I 

.       .99        74154.   ,  ,   . 

,  ,  ,L95 

7417 

.2/1.10        74 157,    .   .   . 

,  .       .99 

MaJ 

1.                ■                  ■.                B 

.  2/,es        7416K  .   . 
.   .1.1$        74164.   ,  .  , 

.  .   .1.19 

7447  . 

.   .   .1.59 

7474 

.  .       .69        74174.  .   .  . 

.   .   .1.59 

7475 

.  ,       J9        74175.   .   . 

.   .   .1.49 

7476 

.       .69        74192,   .  . 

,   .   ,U9 

7485  . 

.   .1.19        74193.  ,   . 

,  .  ,   .1.19 

74S6 

.  .a/L19        74367.   .   . 

.   .       .99 

7489 

. 

.     3.99        74393.   .   , 

-   ,   AM 

POTENTIOMETERS 


t? 


St 


;'  r 


2  Watt  @  70°C 

7/8"  Slotted  Shaft 

Linear  Taper 

IK  5K  10K 
25K  50K  100K 
1  IVIeg 

CMU  . .  $2.95 


-^-u^.- 


I 


3/4Watt  (§>70°C 
15  Turn  Pot. 
Linear  Taper 

lOOn  500n  IK 
5K  10K  50K 
100K   500K  1IV1e9 

83QP..$1J9 


IWff    CMOS 


4000 
4001 
4002 
4O06 

4009 
4010 
4011 
4013 

4016 
4017 
401B 
4020 

4023  ,  .  . 

4024  .  .  , 
4027  .  .   . 


.69 

4030  ..   . 

.69 

4040  .  .   . 

,69 

4044  .   .   . 

L95 

4046  ,.  . 

.89 

4047  .   .   . 

.85 

4049  ..   , 

.69 

4050  .   .  . 

M 

4051  ,   .   . 

M 

4066  ..  . 

1.49 

4069  .   .   . 

1.49 

4070  ,   ,   . 

2.19 

4071   .   .   . 

.49 

40ai   .   .   . 

1.29 

4093  .   .   . 

.89 

4511  .   .   . 

CONNECTORS 


44  .»«v*--.tu^v4^  ^^,:^^L.^  M^^^ 


DB2SP 

DB25S 

DB51226 

22/44SE 

UGSS/U 

UGB9/U 

UG17S/U 

S0239 

Pi-25^ 

PL259 

UG260/L> 

UGi094/U 


D^Subnifi  nlature'Pl  Ug 

D-Submlniatuire  Socket 

Cover  for  DB25P/S 

P.C.  Edge 

BNC  Plug 

BNC  Jack 

UHF  Adapter 

UHF  Panel  Recp. 

UHF  Adapter 

UHF  Ptug 

BNC  Plug 

BNC  Bulkhead  Recp. 


fl^  LINEAR  ffi^ 


LIV130LN. 

LM305H. 

LJV1307N. 

LJV1308N. 

LM309K. 

LM310N. 

LM311N. 

LM317T. 

LM31BN. 

LJV13I9N. 

LM320K-5 

LM790ST 

LJV17912T 

LM7915T 

LIV1323K. 

LM324N. 

LM337T, 

LM339N. 


LM7805T 
LM7ai3T 
LM7815T 

UM3S0N. 
LIV1334N, 
LIVI555N. 
LV1656N. 
LfV]56SN. 
LM566N. 
LM567N. 
LM723N. 
LIV1741N. 
LM1310N 
LIVI1458N 
LIVil4B8N 
LM14&9N 
LIVI  laOON 
764  77  N.   . 


■fttfV^.-. 


X-^: 


*■•■ :. 


fm 


GRAB  BAGS 


GBIOO 
GBlOl 

G  B102 
GB103 
GBIOS 
GBllO 
0  8113 
GB116 

eeii? 

GB12D 


Cer.  Caps.  (100)  2.^ 

IVtylar  Caps,  (60)  4.95 

Elettrolytks  (GO)  4.95 

Tantalurns  (4oj  4.9S 

TTL  IC'S  (50)  4.9S 

Asst.  LED5  (lOO)  5JS 

Trimmers  (30)  4.95 

^w  Resist.  (20OJ  2JS 

ViW  Resist.  (200)  2.95 

Slide  Switch  f25)  3.95 


GB123  Heat  Sinks  {30)  3.95 
GB127  Transistors  (100)  3.95 
GB137  Chokes  (50)  3.95 

GBl3i  Term.  Strips  (40)  3.95 
GB140  Spcf/Stndtf  050}  2.95 
GB141  Washers  (ZOO)  2.95 

GB14S  LugsdOOi  2.95 

GB154  1&2W  Resi$t.  [1003  2.95 
GB162  7'Se9.  Dsplys.  (50)  5.95 
GB173  3/8"  Pots.  flOO)       5.95 


REGULATED  POWER  SUPPLY  KIT 


**y 


•^. 


t-i 


Uses  LM309K.  Heat  Sink     _ 
provided.  PC  board  con- 
struction. Provides  a  solid 
1  amp  @  5  volts.  Can  supply  up 
to  ±5V,  ±9V  and  ±12Vwvitli 
JE205  Adapter.  Includes  compo- 
nents, hardware  and  instructions. 


M^^UU       ■       k       m       m       m       m       m       ■■       m      W       ■■       ■#■«■■      1^     |  *T  ■  *7  O 


DESK  TOP  ENCLOSURES 


DTE-8     (PicturedJ $31,95 

DTE-11  (PicturedJ 34.95 

DTE-14 36.95 

DTE  HK  (Case  for  JE600)     ,.<......  47.95 

DTE-AK  (Case  for  JE610)  (Pictured  J    _.  5Z95 


VIDEO  CONTROLLER 


vf^. 


View 


liiEFde 

Ra»r 
Viaw 


S 


JVC-40 


tdeal  for  all  video 
games  or  remote 
control  projects. 
Two  mini,  pots. 
40K  ohm  each. 
SPSTpush  button 
control.  Five-wire 
connect! ori  cable 
5'  long.  Hugged 
plastic  case  — 
1^^"H  X  2-3/8"VV 
X  4-5/16"L 

.  .  $5.95  each 


Discount    lim-i 


74LSOO. 
74LS02. 
74LS04, 
74LS08. 
74LS10. 
74LS14. 
74LS30. 
74LS32. 
74LS3E. 
74LS43. 
74LS47. 
74LS4e. 
74LS73. 
74LS74. 
74LS7S. 
74LSS5, 
74LS90, 


LS  Schottky 


74USi09 
74LS123 
74LS138 
74LS139 
74LS1M 
74LS1S7 
74LS161 
74LS174 
74LS175 
74LS192 
74LS193 
74LS22J 
74LS244 
74LS24S 
74LS367 
74LS374 
81LS97. 


2.49 
IM 
1.79 
h79 
1.79 
1.89 
1.39 
1.95 
2.49 
3.49 
1.29 
2.49 
2.49 


SOCKETS 


Low  Profi 

S  pin  LP    ,  .  . 

14  pin  LP  .  .  . 
16  Pin  LP.   .  . 

15  pin  LP,  .  . 
20  pin  LP  ,  .  . 
22  pin  LP  .  .  . 
24  pin  LP  .  .  , 
2B  pin  LP  ,  .  . 
36  pin  LP  .  .  . 
40  pin  LP  .   .  . 


le  Wire  Wrap 

2A59  14  Pin  WW  tin       .75 

2/.69  14  pin  WW  gold  1.09 

2/. 79  16  pin  WW  tin       .79 

2/.a9  16  pin  WW  gold  1.19 

2/.99  24  pin  WW  gold  1.69 

2/1.09  40  pin  WW  gold  2.75 

.79  14  p.  plug/cover  1.29 

.82  16  p.  plug/coverL39 

.99  24  p,  pfug/coverL9S 

1,19  +  mofe5<  p./$ocl<et5 


DIODES  &  TRANSISTORS 


ir\J751  . 

IN757   . 

iNiiaa. 

IN  3600. 
IN4001. 
IN4004. 
IN4007. 
IN4148. 
IN4733. 
IN4734. 
IN473S. 
m4742. 
IN4744. 


.  2/.59 
.  2/.S9 
.  2.69 
.  5A99 
.  4/.59 
.  4/.69 
.  4/. 79 
.10A99 
.  2A69 
.  2/.69 
,  2/.S9 
.  2/.69 
.  2/.S9 


2N2219A. 

2N2222A. 
2N2907A. 
2N305S,  . 
2N3772.   . 

2N3904.  . 
2N3906.  . 
2 N 4401.  . 
2N4403.  , 
2N5129.  . 
2N6139.  . 
2N5210.  , 
2NS95L   . 


2/1.19 

2/.S9 

2/.89 

.99 

2,25 

,  2/.69 
2/.  69 
2/.79 
2/.  79 
2/.69 
2/^69 
2/.79 

2/L29 


CAPACITORS 

Dipped  Tantalum         ELECTROLYTIC 


.lmfd^35V  2/,&9 

.47mfd@35V  2/.89 

lmfd'§>35V  2/.a9 

2.2m1d@2SV  2/L09 

3.3mfd@25V  2/1.19 

4.7mfd@25V  2/1.39 
10mfd@25V  1.19 

33infd^25V  195 

100V  MYLAR 


,001-.01mfd 
.022  m  fd 
.047m  fd 
.Imfd 

.22mfd 


4/.  79 
4/.S9 
4/.93 

4/ia9 

4/1.29 


lmfdi3i50V  3A69 

4.7mfdP50V  2/.59 

lOmf d  ®50V  2A69 

22mfcH9!50V  2A79 

47mfd;S!5ov  2/.S9 

I00rnfd@50V  .59 

220mfd@5OV  .69 

lQ00mfd@25V/  L19 

22<50mfd@15V  L39 

50V  CERAMIC 

10pf%022nntd  4/.59 

.047mfd  4A69 

.Imfd  4/.  79 


MICROPROCESSORS 


ZSOA 

MC6  SOO 

e080A 

8212 

S216 

2513/2140 

ST97 

AY  5-1013 

AY'5237S 

2114-3 

M  K4116 

270S 

2716 


CPU  (4MH2J 

B  Sit  fsAPU 

CPU 

B  Bit  I/O  Port 

Bi-Directiona!  Bus  Driver 

Charactet  Generator 

Tri-Stale  Hex  Buffer 

3QK  Baud  UART 

86-Key  Keyboard  Encoder 

4K  Static  RAM  £300nsl 

16K  Dynamic  RAM  C2S0nsj 

eK  EPROM 

16K  EPROM  (+5V) 


14.95 

14.9S 

7.95 

3.95 

4,49 

12.95 

2.25 

6,95 

13.95 

9.49 

9.95 

10,95 

19.95 


ONE 

DOLLAR 

Discount  Coupon 

OFFER  EXPIRES 
DECEMBER  31,  1980 

Redeemable  at 
participating  JIM  PAK 
Distributors  for  Sl.OO 
discount  on  purchases 
of  JIM-PAK  components 
exceeding  $1.00 


elecfronic  components 


Coupon 

GOOD  FOR 

ONE  DOLLAR 

DISCOUNT 

on  purchase  of  any 

JIM-PAK  PRODUCTS 

at  participating  Distributors 


ONE  DOLLAR 

One  Coupon  Per  Customer 


Mr.  Di^ributor:  Jjm-Pak 
wilk  accept  this  coupon 
for  one  dollar  credit 
when  returned  to  us  with 
your  regular  orders. 


80     73  Magazine  •  December,  1980 


33 
I 

!^ 
en 


O 

Q 


3 

KU 


O 


O 
CD 


H 


a 

CD 

3 


CD 


m 


CJI 
Cl 

CO 


S 

03 

a 

D. 

-^ 

go 

3 

o 


n 
> 

CD 
O 

o 

en 

CD 
03 


Cl>P 


Tn  o  Tfv  s  s  15  ^  O  ?  ^ 


r^ 


03 


.?»  =i 


n.  D  ts  n 
o  *  "^^  6 

m 


o 


I 


g» 


3 


lift 

^  Q 

a 
o 


g 


■-.  --1.  hi    3    rt  's 

r,    ■^    "*    ■^  Bi    T 

=*  '^  '^  5"^ 


s  ^ 


q:  a  ^  ^  ^  :^ 
^3 


b   Si   ft   Ct 


ti  a  ? "  5  ^ 


I  3}>„Tl 


m 


■"  1  S 


^ 


t 


^   ct,   ^  -J-        a 
S  5  ^  i;  O  IB 


11 


s  ;t  Sl  ^  55.  3. 5 


£■  a  ft.  t»  ^ 


iS^    J"    i^ 
■D     te     ^ 


fij    00 

r 


3  Cl 


s^  *|  *"  :e 


^a 


SI 


Q'  >  c 


tf  ?  5  > 

g    qj    Cb    ^ 
!?   -   3-  _ 


^'  33  C 

si 


t3    i^    3 

^  i'  E; 


i 


|53 
I*  P  5^ 


[^ 


?S5 


i  n  cv 
dS2 


fl  "^  5 

^  5'  s' 


I 

3f  ?  ^ 
c%  f^  fl 


rn  ft  IB 

rtf  i»i  rtj 

tS  th  ^ 
n  rj  n 
"^  -^  "^ 

€  S  £ 
3  3  3 

s-  f?-  s- 

«9      >«      (A 


§r 


K*. 


s  a  5 

S  "  ? 


3    9   * 
T   5'  m. 


^  ^  5" 
n   'T   r^ 


2^ 


III 


5 


5"^ 
i  ^ 


I^  S  £  li  g- 


9 

I 


I 

5  S  Q 

s  ^  ^ 


m  tTii 

•4   I^   -^ 

»*  ■«  <t 


? 


C.3 


Q'  in" :![ 


3  "1  ni*n 

_^    HI      iM.     »^ 

p*  iS    O    Q    O    fc 

S  S  a  a   a  rh 
I  ??  ?!■  t^'  S'  5! 

O     -1     ta     *!     40     ^ 


2.  t 

It 


c 


5*     T 


5  5?*^ 

ft,    IB    Hi 

c%  n  H 


5   Cr  '^  if  5   te 
ft  ^  50 

I    ' 


3-  to  ^  f  ■*  (ft  > 


-  1^  3  lie 

»r      t  t  S  5  a 
*  2  5  > 


=  =*-  3)  ft  ™  ^ 
rn  Jti  g  ^  iti  tn 


.  _     "^     ^  r.«.  "^     "^     *■*     ^*     "* 


5^ 

n.'  ~ 

1* 


**  t*  ft 


5  5*355 

t^.   Ill    *   Q    -ta    (,, 


s1 


5.i?  as 

r),      -^  r^     .^ 

S  a  a  a 

3    in  ki-    -In 


I  ^ 


5:  i 


g  tTimhirnrtirnrvirnrn 

4ti  4  fb  lb  ni  ft 

T^  ft  r>  o  n  t^ 

^  ■*  ■»  ■*  -^  ""i*. 

33  3  5  5_  5 

^'  ft'  ft'  r>  i>'  fi' 

h    ta    4f4    H  ^    4a 


iTi  ruiTi  r 

5  5^^ 
5  5  5  i 

tV'  Cl"  f]'  5 
*>    »ih    **    -^ 


J? 

i 

n' 


I 

:5  *^  ;;  Cfl  i 

■O  D    ^  -lb 

&"?■  ^'  5.  -. 

fcV  ^    ^a    *    > 


3 

i 


r- 
ST 


s-  ^  *~  ^ 

tTi  m^  5 
S  5"  ft'  5" 

5  s.  s-  s.  3 
ft  ft  2  "5"  ft 


^ 


5 


B 


S"  i  :i  :i  ^  I  B  3  - 


3 

■^ 


00  3^^^ 

^  3  S-^ 


—   Q.  -Tl    Cf   [f 

I  5  "  ^  3- 

i  S  tfl  ss.  K 

*  "^  -■ 


3 


P 
si 


I 

o  s  t 


S 

* 

3 


ri 

(a.  ft, 
5  5; 

a  t* 

in    It, 


7  1%  s 
g  ft  > 


p  ^  SB  p 


'^  5  i  -,- 
?  a  fi  ^  p 


I 


fb 


^5 


=  3  i 


>  I  q'  S 
3  S"  t  ^ 


o 

c 


■i^       -i-n        .^   *■"   ^   't 

5  E>^i      I  5  I  5 


;  ft  3 
V?  ^  5  '^^ 


ZLfli   ^;   ^   a 

*  a  *  a-  3 


4 


30 

m  ft 


Q^B 


-^  X 


'^  ft 

b  ft' 
d'  ()' 

It 


1^  s 

<k      rni 

s  ^  ^ 

i  "T-  ''■ 

sis 

S55 

■ft  a  & 

■^       -^      K« 

*   Sf  5 


^  ft'te 


S  E 

> 

z 


o 

o 

-■ 

I 


I 

a 


? 


'I  P'  ft  ft]  S" 

q.   P   g   23X   30  C 


■^ 


I 


=  1 

ifi 


^2 

-a  Tj 
OO 


> 


e  K  ^ 


a 


14 


5  :i 


"  S-  S  ?i  ^  'ff  5  5J 


0  05^ 


?  s  5  S*' 


5 


*;  a"  ^  ft  -^ 


rri  ti  o  o  5j  3  gi 
i^-t  ^  ft  g  z5- 


I 

3 


I 

5 


£ 


5?^ 

^      a  * 
t«»5   3  Tj 


S'  4a 


f 


ft  3 


:^    b 


1* 


^5^n5 


3^- 


I 


FredCerfcen  WB0LLP 
7(m  Knight  Drive 
Box  91910 
LewiBvtIle  TX  75056 


Clean  Sweep  for  the  FT-221 


don't  miss  the  action 


SSB  on  two  meters  is  be- 
coming more  popular  in 
my  area,  and  activity  cen- 
ters around  the  national 
calling  frequency  of 
144,200  MHz.  So,  whenever 
I  am  in  the  shack,  I  turn  on 
my  FT-221  and  position  the 
vfo  on  that  frequency.  Sev- 
eral times  I  have  listened 
for  hours  to  the  rush  of  the 
receiver,  not  hearing  a 
peep,  only  to  move  the  vfo 
dial  when  passing  the  rig  on 
the  way  to  the  807  locker 
and  find  a  QSO  in  progress 
a  few  kHz  away. 

This  half-hearted  moni- 
toring causes  me  to  miss 
much  of  the  local  activity. 
In  order  to  soive  this  prob^ 
lem,  t  have  added  a  clarif  ier 
sweeper  to  the  rig.  This  al- 
lows me  to  monitor  144.200 
±  8  kHz  in  a  sweeping 
mode. 

The  Yaesu  FT-221  has  a 
broad  clarifier  which  uses  a 
varactor  diode  in  the  local 
oscillator  module.  By  vary- 
ing the  voltage  on  the 
varactor  from  one  to  eight 
volts,  the  clarifier  has  over 
±  8  kHz  of  tuning  range. 
The  circuit  in  Fig.  1  provides 
an  inexpensive  pseudo-tri- 
angle wave  generator  with 
an  output  of  one  to  eight 
volts,  and  a  sweep  time  of 
one  complete  sweep  ap- 
proximately every  four  sec- 
onds. 

The  circuit  is  designed  to 
be  both  small  and  inexpen- 
sive. The  555  timer  is  wired 
as  an  astable  square-wave 


generator,  and  R1C1  forms 
an  integrator  which  con- 
verts the  square  wave  into  a 
triangular  wave.  See  Fig,  2. 
For  the  purist,  an  op-amp  in- 
tegrator could  be  substi- 
tuted for  R1C1.  See  Fig.  3. 

Once  the  sweeper  is  as- 
sembled, check  the  output 
voltage.  The  output  should 
swing  slowly  towards  Vcc 
and  then  slowly  back  to 
about  1.0  volt  and  start 
over  again. 

Installing  the  sweeper  in 
the  FT-221  is  a  matter  of 
preference.  A  simple  toggle 
switch  could  be  used  to 
control  the  sweeper,  as 
shown  in  Fig.  4,  If  you  are 
the  type  who  hates  to  cut 
holes  in  a  $600  rig,  you 
might  try  substituting  a  new 
clarifier    pot    and    SPST 


VOLT 


B  - 


4  - 


0 


0 


a 


SEC 


Fig.  2,  Waveform  from 
square-wave  generator  and 
RlCl  integrator. 


iOKj 


} 


BLUE 


X 


-*TQ.  ^WPR- 


5.6K 


/^ 


TO  VARACTOR 


Fig.  4.  Hookup  using  toggle 
switch. 


82     73  Magazine  •  December,  1980 


switch  for  the  original  pot 
See  Fig.  5.  This  method  is 
my  choice.  Only  the  new 
pot  and  two  diodes  need  to 
be  added.  When  the  clari- 
fier knob  is  rotated  fully  un- 
til the  switch  clicks,  the 
sweep  mode  is  engaged. 
When  the  clarifier  knob  is  in 
any  other  position,  it  func- 
tions noi^mally. 


The  circuit  itself  is  very 
small  and  mounts  any- 
where room  is  available. 
However,  there  is  a  good 
spot  just  in  front  of  the  crys- 
tal deck.  The  eight  volts  dc 
to  run  the  sweeper  is  easily 
obtained  from  the  clarifier 
pot  itself.  See  Fig.  5. 

Happy  sweeping!  ■ 


+  flVOC 


A 


;:i20K 


/77 


13'0|( 


555 


10  V 


/n 


m 


toy 


S.6K 


-^  OUT  Put 


'T' 


m 


lOV 


Fig.  1.  Pseudo-triangle  wave  generator. 


+av 


47QK 


t 


lOOK 


*|  OUTPUT 


Fig.  3,  Op-amp  integrator  using  LM118. 


+  6-V 


■5OK 
UHEAM  ft— 
$PST  ^     " 


s*- 


ffr 


BRWAWT 


— T" 


-*T0   VARACTOR 


1  av 


5.eK 


OUTPyj 


GND 


Fig.  5.  Hookup  using  new  clarifier  pot  with  SPST  switch. 


i 

T 


I 


T 


»L 


I 


T 


;<• 


I 


A  new  name^  a  new  look^  and  a  new  standard 

of  performance  in  ham  radio! 

{and  you  don't  have  to  be  a  computer  expert  to  use  it!) 


ALL  BANDS  rNSTALLED 
AND  OPERATING! 
160  thru  10 
jncludlng  WARC  bands 


DUAL 

ultra  stable 
PTOs 


Fast 

break-in 

(QSKJ 


Buih-jn 
VSWH  meter 


CW  outpui 
pulse  shaping 
^»  hard  or  soft 


Sophisticated 
Noise  Blanker 


RTTY 
VOX 


Jack 

for  separate 

receive 

antenna 


Fully  variable        Dual  8* pole  filters, 
AGC  decay  L4:l  shape  factor 

-6  to  -lOCkiB 


Speech 
Processor 


Exceptional  Dynamics 
Noise  Floof  ]a2dBm 
3rd  order  intercept  +  ISdBm 


RF/EF  Gain 
Controls 


True  P^ssband 
Tuning  with 
width  and 
position 
indicators 


Of^tonal  CW 
Narrow  Crystal 
Filter 


%  CUPIC 


ASTRO- 103  - 
The  Professional 
Ham  Rig.    ^ 


Th€  Cubic  ASTRO^  1 03  expands  on 
the  highly  acdaimed  ASTRO402BXA 
with  the  addition  of  the  most  asked  for 
features  —  RTTY,  an  input  connector  for 
a  sepiarate  receive  antenna,  and  of 
course,  ALL  BAND  coverage  from  160 
through  10  meters,  including  the  new 
bands  at  10,  18.  and  24  5  MHz,  All  bands 
are  operating  now,  nothing  to  buy  later, 
and  of  course  WWV  is  covered. 

With  the  optional  400 Hz  aystal  filter 
instBlled,  which  cascades  with  one  of  the 
8'pole  I.F.  filters  and  can  be  moved 
through  the  passband,  along  with  QSK 
provisions,  the  ASTRO-103  is  the  CW 
operator  s  dream! 

Performance  under  high  cross  mod 
conditions  found  in  todays'  crowded 
bands  is  second  to  none.  With  dual 
independent  high  stability  PTO*s  for  split 
band  DX  and  all  its  other  features,  the 
ASTRO-103  is  the  result  of  American 
Technology  and  American  Quality 
combined  to  bring  the  best  to  the 
American  Amateur* 


Se^e  your  dealer  for  a  demonstration  - 
you  won't  leave  the  store  without  onei 


CUBIC -^ 

Built  on  Excellence 


Cubic  Corporation  udfh  over  3*500 
employees  world-wide,  includlr^  more 
than  1200  sdeniists,  engineers  and 
technicians,  has  more  than  one  miUion 
square  fe<^  under  roof 

Established  in  1951  the  company  has 
grown  and  expanded  in  high  technology 
fields,  including  computer  based 
automatic  fare  coU^rtion  systems, 
etectronic  countermeasures,  supersonic 
pilot  training  and  other  defense  and 
space  systems,  electronic  positioning 
<tevdces  and,  of  course,  communications. 
New  Cubic  Amateur  products  reflect  this 
heritage  of  excellence  and  is  your 
assurance  of  the  strength  and  resources 
to  support  your  purchase  in  the  years  to 
coma 


ASTRO-L50A 


Ar>otheT  member  of  the  ASTRO  family,  the 
AStTtO-150«  has  been  highly  acclaimed  as 
the  ideal  Mobile;Base  statiDn.  With 
microprocessor  control,  VRS  tuning  and 
microphone  scanning,  the  ASTRO*  150 A 
led  tfie  way  fpr  competitive  radios  now 
appearing  on  the  markeL 


The  ASTRO  102BXA  provides  basically  aU 
the  hne  performance  of  the  ASTRO-103  at  a 
lower  cost,  but  less  the  WARC  band^,  which 
of  course  may  be  added  later  If  desired. 

•  CUBIC       ^TD 
COMMUNICATIQNS.INC. 

305  Airport  Road.  Oceanside.  CA  92054 
(714J  757-7525 


Dave  ingram  K4TWI 
Eastwood  Village.  #7207  South 
Route  11  Box  499 
B ; f m 'mgha m  At  3521 0 


A  New  Frontier 

weekends  were  made  for. .  .10  FM! 


During  recent  years,  FM 
has  become  one  of 
amateur  radio's  most  popu- 
lar and  widely  accepted 
modes  of  UHF  communica- 
tion.  The  convenience  and 


flexibility  of  channelized, 
squetch-muted  equipment 
continuously  appeals  to  nu- 
merous amateurs. 

The  excitement  of   low- 
band  DXing,  however,  em- 


braces a  unique  pleasure 
which  all  amateurs  cherish 
—  a  thrill  as  old  and  irre- 
placeable as  ham  radio  it- 
self. Wouldn't  it  be  inter- 
esting   to    combine    these 


Photo  A.  Recipe  for  mountafntopping  fun  with  10  FM  includes  (left  to  fight]  a  Cushcraft 
10-meter  FM  Ringo,  an  MFf  antenna  tuner  with  knapsack  full  of  loose  and  long  wires,  Com- 
tronix  FM-80,  and  a  2  meter  hand-held  talkie. 


two  modes  and  enjoy  inter- 
continental FM  operations? 
Imagine  an  ample  supply  of 
remote-base  setups  and  re- 
peaters capable  of  practi- 
cally worldwide  communi- 
cation in  this  vision  and  you 
have  an  accurate  descrip- 
tion of  10-meter  FM  —  a 
frontier  which  is  presently 
blowing  wide  open  with  ex- 
citement. 

Although  FM  communi- 
cations have  been  taking 
place  on  the  high  end  of  our 
10-meter  band  for  several 
years,  this  mode  only  re- 
cently gained  widespread 
popularity.  Two  of  the 
prime  reasons  for  this  up- 
surge are  the  increasing 
sunspot  activity  and  the 
availability  of  commer- 
cially-manufactured IO- 
meter FM  equipment,  The 
introduction  of  Yaesu's  FT- 
901DM  all-mode  160- 
through  10-meter  deluxe 
transceiver  and  the  Com- 
tronix  FM-80  10-meter  FM 
transceiver  substantially 
promoted  10-FM  activity. 
During  the  period  of  a  few 


84     73  Magazine  *   December,  1980 


Repeater  Inputs 

29,520  kHz 
29,540  kHz 
29.560  kHz 
29.580  kHz 


International 
Ofrect  Frequency 

29.600  kHz 


Repeater  Outputs 

29,620  kHz 
29,640  kHz 
29.660  kHz 
29,680  kHz 


Table  T.  Ten-meter  FM  band  plan,  ''Direct"  operation  on 
repeater  output  frequencies  is  acceptable  provided  deliber- 
ate interference  isn't  created. 


months,  10  FM  actyally 
eanne  alive  with  worldwide 
FM  operations.  This  activity 
continues  to  grow  each 
day,  as  innovative-minded 
amateurs  clamor  to  join  the 
tun. 

Overview  of  10-FM 
Operations 

Although  a  number  of  in- 
band  repeaters  are  opera- 
tional on  10  FM,  most  of  the 
activity  is  "direct"  commu- 
nications on  the  Interna- 
tional Direct  Frequency  of 
29.600  kHz  or  the  repeater 
output  frequencies  of 
29,62a  29.640,  29,660,  or 
29.680  kHz  Thus  far  the 
use  of  direct  communica- 
tions on  repeater  output 
frequencies  has  proven 
quite  acceptable  on  10  FM, 
provided  rt  doesn't  interfere 
with  the  normal  repeater 
activities  on  that  channel 
Due  to  the  limited  spec- 
trum allocation  for  10  FM,  a 
tight-fitting  and  conscien- 
tiously adhered-to  band 
plan  is  necessary.  As  this  is 
being  written,  29,600  kHz  is 
being  used  for  brief  QSOs 
and  as  an  international  call- 
ing frequency  with  resul- 
tant additional  communi- 
cations being  carried  out  on 
29,620.  29.640.  and  29,660 
kHz.  10  FMers  realize  the 
long-distance  propagation 
effects  of  this  band,  and 
during  such  times  their 
gentlemanly  procedures 
are  generally  beyond  re* 
proach.  Several  repeater 
groups  are  presently  inves- 
tigating ways  of  improving 
the  10-meter  FM  band  plan, 
but  it  appears  that  the  one 
shown  in  Table  1  will  be  re- 
tained for  many  more 
moons. 

While  10  FM  is  alive  and 
active    almost    every    day 


and  evening,  this  band's 
most  exciting  times  usually 
occur  during  weekends. 
The  fun  starts  early  each 
Friday  afternoon  and  con- 
tinues full  bore  until  the 
band  closes  each  Sunday 
night.  During  these  times, 
signals  from  European, 
South  American,  and 
Japanese  amateurs  have 
been  heard  working  various 
stations  through  repeaters 
in  the  northwestern  United 
States,  and  New  Zealand 
stations  have  been  heard 
transmitting  through  re- 
peaters in  the  California 
area.  It's  not  extremely  un- 
usuaf,  either,  to  hear  two  or 
three  European  amateurs 
communicating  with  each 
other  through  a  US-based 
repeater  during  a  weekend 
on  10  FM  — and  this  situa- 
tion should  also  exist  in  re- 
verse in  the  near  future. 

All  of  the  US-based  re- 
peaters on  10  FM  employ 
PLTM  tone  encoding  to  pre- 
vent unwarranted  in-band 
interference.  Right  now,  the 
most  common  PL  frequen* 
cy  in  use  on  10  FM  is  107.2 
Hz.  When  the  control  op- 
erator is  monitoring  a  sys- 
tem during  the  weekend, 
however,  some  repeaters 
switch  to  straight  COR  con- 
trol to  permit  various  forms 
of  DX  operations  through 
their  machine. 

An  uncounted  number  of 
remote  base  setups  are  op- 
erational on  10  FM.  Some 
of  these  systems  are  per- 
manent arrangements  used 
by  many  amateurs,  while 
other  remote  bases  are  pri- 
vate systems  created  by 
interconnecting  one's 
10-  and  2'meter  FM  units  as 
desired.  Another  possibility 
for  the  near  future  is  that  of 
mobile  remotes,  produced 


Photo  B.  Receiver  section  of  WR6BDQ  the  2%  620-kHz  FM 
repeater  in  Sierra  Madre,  CaVtiornia.  This  repeater  is  mairh- 

tained  by  David  Findley  N6DF  and  fohn  Fortune  WB6ZCT, 
During  weekends,  Dave  and  fohn  occasionally  swifch  this 
machine  to  straight  COR  function  for  '"open"  access.  The 
transmitter  of  WR6BDC  is  approximately  one  mileaway^  at 
the  QTH  of  WB6ZCT. 


by  interconnecting  one's 
10-  and  2-meter  mobile  FM 
rigs.  These  units  can  be 
used  separately  while 
mobile,  or  the  10-meter  unit 
can  be  2-meter-accessed  by 
the  operator's  NT  when  he 
leaves  the  car.  An  irvcar 
rubber  ducky  2-meter  an- 
tenna will  restrict  the 
2-meter  access  range  of  this 
system. 

Equipment 

As  previously  mentioned, 
the  introduction  of  Yaesu's 
FT-901  series  transceivers 
and  Comtronix's  FM-80 
units  has  been  a  contribut- 
ing factor  in  the  recent 
growth  of  10  FM,  Prior  to 
this  evolution,  the  bulk  of 
lO-FM  equipment  consisted 
of  converted  low-band  (30 
to  40  MHz)  business  radios. 
Both  the  Yaesu  and  the 
Comtronix  are  superb  per- 
formers on  10  FM. 


FM  capability  is  standard 
on  the  FT-901  DM  and  an 
available  option  on  the  FT- 
901  D  and  DE  transceivers. 
Power  output  is  approx- 
imately 20  Watts  in  the  FM 
mode.  The  unit's  memory  is 
perfect  for  programming  re- 
peater "splits/'  and  its 
squelch  circuit  operates 
very  smoothly. 

The  Comtronix  operates 
80  discrete  channels  of  10 
FM,  and  the  standard  10-FM 
repeater  offset  of  100  kHz 
is  accomplished  by  a  switch 
on  the  unit's  squelch  con- 
trol. The  rig's  front-panel 
meter  reads  S-units  on  re- 
ceive and  relative  output 
power  on  transmit.  Addi- 
tionally, a  front-panel  LED 
varies  in  intensity  accord- 
ing to  transmitted  modula- 
tion, while  another  LED  (bi- 
polar) lights  green  during  re- 
ceive and  red  during  trans- 
mit.   Power  output  of  the 


73  Magazine  •  December » 1080    85 


an 


Comtronix  is  10  Watts  (high 
power)  or  1  Watt  (low 
power).  The  low  power  of 
both  the  Yaesu  and  the 
Comtronix  is  synonymoys 
with  10  FM.  50"Watt  sta- 
tions are  considered  high 
power,  and  250-Watt  sig- 
nals are  "super  power''  — 
and  usually  are  unneces- 
sary. 

Conn  merci  ally-manufac- 
tured antennas  for  10  FM 
also  are  beginning  to  gain  in 
polularity,  Cushcraft  re- 
cently introduced  a  10-FM 
Ringo  which  looks  very 
simitar  to  their  2''meter 
Ringo  except  that  if  s  much 
larger  (17  feet  tall— and  it's 
great!]. 

Newtronics  recently  in- 
troduced their  HOT  10 
trunk-lip-moynted,  center- 
loaded  mobile  antenna  for 
10  FM. 

There  are  a  number  of 
antenna  tuners  which  the 
10-FM  enthusiast  will  find 
beneficial  when  tuning  a 
beam  or  random  length  of 


wire  for  operation  on 
29,600 ±  kHz.  MFJ  Enter- 
prises manufactures  a  full 
line  of  these  items,  and  any 
of  their  tuners  that  I  Ve  tried 
have  worked  extremely 
well. 

Finally,  there  are  a  large 
number  of  CB  sets  which 
may  easily  be  converted  for 
10-meter  FM  operation. 
Basically,  this  conversion 
involves  three  steps:  Move 
the  unit  up  approximately 
2.5  MHzTn  rf  range,  replace 
the  AM  modulation  with  an 
FM  modulator,  and  change 
the  receiver's  AM  detector 
to  an  FM  counterpart.  Sev- 
eral articles  concerning  CB- 
to-IO-FM  conversions  have 
been  published  in  amateur 
magazines  recently. 

Getting  Started  On  10  FM 

Joining  the  fun  of  10  FM 
will  probably  bear  a  striking 
resemblance  to  the  time 
you  first  became  involved 
with  2-meter  FM.  You'll 
probably   locate   and   con- 


vert a  business  radio  for  10 
FM,  convert  a  CB  set  to  10 
FM,  or  purchase  a  Yaesu  or 
Comtronix  for  10  FM.  Op- 
erating techniques  may 
seem  different  from  IO- 
meter SSB  activity,  but 
you'll  get  the  hang  of  it 
within  a  couple  of  days  — 
and  wonder  why  you  didn't 
try  10  FM  sooner. 

Remember  to  keep  your 
transmissions  short  when 
there's  any  possibility  of  in- 
terfering with  distant  QSOs, 
and  never  conduct  lengthy 
direct  communications  on 
a  repeater  input  frequency. 
As  with  any  new  mode  of 
communications,  the  prime 
key  to  successful  operation 
involves  listening  exten- 
sively to  learn  the  tech- 
niques of  that  mode.  10  FM 
doesn't  hold  a  money-back 
guarantee  of  fun,  but  you 
can  feel  relatively  confi- 
dent that  there  will  be  nu- 
merous amateurs  waiting  to 
purchase  your  used  10-FM 
gear  should  you  decide  to 


sell  out  and  return  to  S SB- 
only  activities. 

Conclusion 

The  amateur  frontier  of 
TO  FM  is  growing  at  a  fan- 
tastic rate,  and  this  mode 
has  an  extremely  promising 
future.  Long-distance  com- 
munication via  FM  is  a 
unique  experience  — and 
this  aspect  blends  perfectly 
with  today's  frantic  life- 
style and  mobile  operating 
techniques.  This  band  is 
much  smaller  in  rf  spec- 
trum than  other  FM  bands, 
so  considerate  and  sophis- 
ticated operating  tech- 
niques are  a  vitally  impor- 
tant consideration. 

All  aspects  considered, 
10  FM  should  prove  an  ex- 
citing experience  for  the 
progressive-minded  ama- 
teur. Its  DXing,  casual  op- 
erating, and  mountaintop- 
ping  pleasures  add  new  life 
to  an  amateur's  interests. 
Here's  listening  for  you  on 
twenty-nine  six!B 


SIMPLY  THE  BEST! 

FOX  TANGO  FILTERS 

YAESU-KENWOOD-DRAKE-COLLINS-HEATH 


Whether  your  SSB  rig  Is  old  or  new, 
there  is  no  easier  or  essentialty  less 
expensive  way  to  significantly  up- 
grade its  perforfT^ance  than  by  improv- 
ing Its  IF  passband  filtering  FOX  TANGO  filters  are  made  of  specially- 
treated  high-Q  quartz  crystals,  affording  excellent  shape  factors  and 
yllimate  rejection  exceeding  SO  d8  They  are  custom  made  tor  drop-in 
installation;  matching  perfectly,  tsoth  physically  and  electfonicaHy,  Our 
Diode  Switching  Boards  make  possible  (now  or  in  the  future)  the  addi- 
Uon  ol  a  variety  ol  swilch-selectable  filters  affording  superior  variable 
bandwidth  wtthoul  the  need  to  buy  an  expensive  new  model  It  you 
want  the  best  lor  less,  you'll  buy  FOX-TANGO.  Just  tell  us  the  band- 
width (s)  desired  tor  your  make  and  model. 


*DIOOE  SWITCHING  BOARDS  available  to  pernnit  1 ,  2  or  more  filters 
than  those  for  whicfn  manutacttirer  provides  room.  SPECIFY  make  and 
model, 

Single-fiiter  type:     SI  2  AirmaH  postpaid  worldwide. 
Dual-filter  type     $21  Airmail  postpaid  worldwide. 

Flond-a  resi<jeni&ad(j  4%  fs^ies  \ax)        [FOREIGN  ADO  S5  per  fjiter) 

Oealf  r  Inquiries  Welcomeii  __^__ 

Visa/MC  welcomed.  Money  back  if  not  satisfied. 

BROCHURE  ON  REQUEST  ^ 

G/FT  CBBUFfCATES  AVAILABLE 


FOX-TANGO  CORP. 


8-POLE  FILTER  BANDWIDTHS  IN  STOCK 


CW  (Hz) 


SSS'AMlhH2| 


YAESU 


■FT401/F/FR-I0I 


fSSEACH 


•FT'30J/FI-7B/6aO 


*FT9O|/l0lZD/Ift7 


FT-40 1/560/570 


FT-200/TEMPO  I 


KENWOOD 


*TS-520/R  S99 


S5SEACH 


•TS-«20/R-820 


•2nd  IFS12S 
tof  ft^BZD  only 


HEATH 


S55EACH 


ALL  HF 


RT 


DRAKE 


FOR  PRICES  SEE  NOTES 


^  GUF-1  Broad  1st  IF  Superior  Shapa  factor/ yit  Rfl)  $65 


,GUF-2  Narrow  1st  IF 


2ndtF 


pcb  w  sw  relays  $90 


ntypw]^^ 


COLLINS: 


GIJD  Prgduct  D9t«dor       Rcb  w  relay  double  baJanced  type  $30 


SPECIAL  S12S  EACH 


7SS-36/C 


EQUALS  OH  EXCELS  $400  COLIIHS  UNIT 


Box  15944S,  West  Palm  Beach,  FL  33406 


^323 


86     73  Magazine  •   December,  1980 


SAVE  $  SAVE  $  SAVE 

CALL  TOLL  FREE 

I-800-228-4097 

We  Offer  The  Lowest  Prices 

In  The  Country 

HAM  RADIOS 

COMPUTERS 

ALLIANCE 

HY-GAIN 

APPLE 

AVANTI 

ICOM 

ATARI 

BEARCAT 

KENWOOD 

BASE  2 

B&W 

LARSEN 

CENTRONICS 

BENCHER 

MIRAGE 

COMMODORE 

CDE 

MOSLEY 

DC  HAYES 

CUSHCRAFT                     SHURE 

MAXELL 

DENTRON 

TELEX 

MOUNTAIN  HDWR 

DRAKE 

TEMPO 

NEC 

ENCOMM 

TRAC 

PAPER  TIGER 

ETO 

YAESU 

PET 

HUSTLER 

VERBATIM 

IN  STOCK  NOW! 


VIDEO  DISC  PLAYERS 


Call  for  Discount  Prices 


^u 


Communications  Center 


r 


1 


FTiasier  chstqe 


1840  'O'  St.,  Lincoln,  Ne.,  68508 
In  Ne.  Call  (402)  476-7331 


V/SA' 


y^  Read&r  Sen/^ce— see  page  226 


73  Magazine  •  December^  1980    87 


Tom  French  WA4&ZP 

All  Systems  Co 

PO  8o)c  915 

Wimor  Garden  ft  32787 


Scanner  Magic  for  Heath's  2036 

grab  your  October  '79  issue  for 
part  I  of  this  project 


Pads  List 

FI1 

90k  (value  vanes,  depending  on  level  of  threshold 

signal—see  text) 

R2,  R3 

1  meg 

R4 

Ik 

CI 

O.OT-mF  disc 

Q1 

2N2222 

1C1-3 

SN74LS183                                                                         1 

IC4 

NE555 

misc. 

DPDT  scan  opeTate  switch,  push-to-scan  switch, 

2">;3"  perfboard 

In  the  October,  1979.  is 
sue  of  73.  an  article  en- 
titled, "An  LED  Display  for 
the  HW-2036"  really  excit- 
ed a  number  of  Heathkit® 
2036  and  2036A  users.  As 
mentioned  in  the  article,  a 
scan  board  circuit  could  be 
piggybacked  to  the  2036- 
DB  Display  Board-  Below 
are  a  few  hints  on  how  to 
build  this  board  and  check 
it  out. 


OPERATE 


I       203b -5B   CLOCK 


I       SC&NNINIG        f 


S03G-MB   STROBE 


LOCATEO  ON   MfC 


•SiV 


J      t. 


i 


SCAti   PQSI  ♦ 


I' 

I 

t        ZEHO    VDC 


5  VOC 


l» I 


LOCATED  on 


f 


■  9 


•3  voe 

It, 


i  „ 


1, 


'E3' 


M*'    >+'  W 

pm  ptH  PiM  mm 

3        4       f        ? 
TO  IC7 


IC2 


H   h^   i<'   V' 

'*■    ^f  re  '  'r 

'vi'  V  w  4' 

fm  ^m  *Hi  Pin 
^       *       fi'       T 


T©  1C« 


CLDC*t  OUT  TO 
SCAM^DP  SWITCH 


"H*'    ^     ^K     W 

flm  ('IN  *n*i  *i«i 
TO  IC5 


4 


3C4 


T 


C) 


f  fg.  7.  2036-SB  Scan  Board  schematic  diagram. 


Acquire  a  2"X3"  piece 
of  perforated  board  and 
mount  it  for  sizing  on  the 
forward  IVa'*  screw  above 
the  2036  DB  With  the 
board  piggyback  on  the 
2036-DB,  position  all  three 
74LS163  chips  and  also  the 
NE555;  don't  forget  to  leave 
a  little  bit  of  room  for  Q1 
and  R1  through  R3.  After 
marking  the  parts  locations, 
remove  the  board.  The 
components  then  can  be  in- 
serted, leads  bent,  and  all 
required  connections  made 
with  wire-wrap  as  shown  in 
Fig.  1. 

Rl  is  a  threshold-setting 
resistor  and  its  value  is  de- 
pendent on  what  signal 
strength  you  wish  the  scan- 
ner to  lock.  The  higher  its 
value,  the  more  signal  is  re- 
quired to  lock  the  scanner 
on  a  carrier  A  trimpot  here 
would  make  adjustment 
easier. 

Clock  Out 
NE555  will  go 
scan  operate 
kHz),  to  provide  a  strobe 
pulse  for  the  SN74LS298s. 
Install  the  push-to-scan 
switch  on  your  mike  at 
some  place  convenient 
(best  location  is  on  top)  and 
use  one  of  the  extra  wires  in 


from  the 
to  the  new 
switch    (0/5 


88     73  Magazine  •  December.  1980 


the  mike  cable  for  the  sig- 
nal back  to  the  2036-SB. 

Next,  install  the  respec- 
tive wires  to  IC5  through 
IC7  from  the  2036  DB  to  the 
2036-SB(see  Fig.  2|  Remove 
the  scan  bridge  on  yoiJr 
2036DB  and  solder  in  the 
wire  from  the  scan  operate 
switch.  Reassemble  your 
unit  and  apply  power. 
Throwing  the  scan  operate 
switch  to  Scan  should 
cause  the  display  to  count 
from  .000  to  999  and  cycle 
again.  H  this  does  not  oc- 
cur, check  the  2036-SB  to 
verity  that  the  scan  clock  is 
active.  Also  read  the  signal 
at  the  2036-DB  on  pin  10  of 
IC4  through  IC7;  these 
should  also  toggle. 

To  scan  147000  to 
147.999,  key  in  7-7-7-7,  then 
switch  to  scan.  The  switch 
should  be  toggled  slowly. 
This  scan  modification  is 
used  to  enable  the  user  to 
locate  new  repeaters  in  a 
new  city,  and  by  no  means 
is  it  competitive  with  pro- 
fessional scanners. 


KBD.  STROBE 


SCAN  BOARD  102 


SYNTH.  0/5  Hi 


SCAN 

6OAR0 

IC3 


DISPLAY 
DECIMAL 
POINT 


KBD.    INPUT 


SCAN    BOARD   ICI 


— ^- 


SYNTH;  MHz 


SYNTH. 
HUND,    KH 


MAKE    THIS 
BRIDGE    IF    NOT 
USING    SCAN 
OPTION 


SYNTH. 
TEN'S   KHz 


Fig.  Z  2036  Display  Board  connections. 


If  your  synthesizer  is  not  mended  that  the  scan  clock 
locking  on  frequency  in  the  be  stowed  down.  This  is  ac* 
scan    mode,    it    is    reconv      complished    by    increasing 


the  value  of  the  two  1 -meg- 
ohm resistors,  R2  and  R3 
(see  Fig.  1).H 


Pcik/ 


Quality  Electronics 
INC.  ^M    For  Less  i 


I 


Organize  your  shack  ivith  a 

CLimERFREE  MODULAR 
CONSOLE  $179.95 

•  Largo,  42"  H  X  57"  W  X  29"D 

•  Strong  groove-construction 

•  Mar^resistant  wood  grain  finish 

•  Options,  drawers  &  face  plate 

•  For  ham  or  home  computer 

•  Visa  and  Master  Charge 

CLUTTERFREE 

MODULAR 
CONSOLES 

P.O.  Box  5T03  Tacoma.  WA  98405 
f 206)  759-1611      ^a& 


299  PIfECISIOH  1IE1I»T9R^.  ^iW,    l\.  Jiul     -Z4ZB        .  ....... 

IC^qUAD  PHDNO  JACM.»,  4ltC«Mchian  2*  f'f     B*li«IH*  111  kp,  i-tUai    .^, 

2S  RCA  PHDND  P|.U<;i.  DopuUF  •i«jil(i..''ip»lifr  ptii|t,   IDOt  ntiUriil,  ylsij}  ...  , 

as. PLASTIC  tRAH^I^tOVrl,  unt#tt«d,  to  92.  »>«t.  IVU*t   l*^  iilMI     .,.^,, . 

35  SLlOi.  iWirCHti,  VJn'IOUk  'l4iR|>tl.  miltt..  vnii  if^tt       312A| 

SD  TRANSl&tOfl  CLECTIIOLVTIiC&.  *»a)tf  «nt4piuljittd.  Mt%l.  t'lluttn  ^ul74Ti     ..  . 
irS-HAk.r  WAITERS    luD\    Lb^ti  c«d*i  PtiPit«ri,  4i«|    .hIm**.       ]lt46 
30-lLIPE  VOLl/HE  CDNfHDI.^.  « mi  put  %«1u*«  «  lyp*^.  t«i  H^  FK  «n        JOS?      . 
50  UPRIGHT  EIECTRD&.  i^Dl,  p»t«n«A  «jplw«»  *■  »«li*i*«,  •nii'htd'.  •   ilW       -  ■ 

ID-PAhEL  SWITCHES,  ttieilr^  i-Dl*rr,  nitrq.  wlkiw.  mtt .       UJti 

30  PA1ft»  RC  A  Wium  A  JACHI.  pdpwIsT  iw  Hi  fi.  ^»*ii«f«.  *lt       UWl 

(»  m9l*  SWTTCHIhC  DIODIt    4  nttnr    «.ii|l.  il^av.  ■ia1a»««4.     •«»  

4-lH3^%S  ttftt  TIIAH»l«TaRt    I  li  watli.  IS  9mp%,  TH>  X  1091  mjrtffiial.     -««» 

»-PL»TiC  IEN&I&    fi«i»tfi«  ilfliPi.  A  FfiJvi       ci&SUr       

}»-CUAiHlC  CAP1&    ttn    itiMitri    UPO  1.  Itnp   f  •tfi^nra^.  vli-      --USt 
S«  TMemiSTOBf .  iifi*t*t  ttPM  A  wtrln.  iMS„CHlK»fi«*1i.  iWi.      «V*v 
lO-IHSrtUltPlT  klwOSS.  1*P  li.*lf  fwmm*  ■Jk«lti.  hpw  «/*vPtt«».      «*!« 
lOilHE  COR^S.,  ■i»*r  'nrl*.  !■  ■•««•.  C.  mtHm4  pii*c.  J  tmm4       Mt4 
lft^2H30S3  HOHT  TRAHUtlOm,  Mapvl.  1*Hwl,  TO  1  U  mt^      4424    .,.,,_,.. 

»-ST19£l)  HHMCATQll^,  rmt  4'M  t  f%  b^W.  tm  M  Tt  r«pLK*«««4.     'Ca**^   _— 

4n-HAV  lA  RiCtlFIEJri.  f»p«  III4CHK.  cpvaf.  aiiMi  '<«dl.       ftl^lL    , 

■^fi«rr  ■EADDirti   n,t  pjk  «   s^HiU*  AAg-.UB    k<;ft    14  pp«^    '449V    --     ^ 
|Q0-PHEFOftlH£il  14  HJiTTCR'S   Miirrtai  ^liiiM^  ptwi  r^  PC  •«•■.   -itel2 
30  ItE  2  EIJLRS  W   tlitifOll.  m**m.  gtmf*  nfM  UH*   I  IS  VAC        «A» 
IS  RCA  PHONO  iACm,  p*9^t*  t^  fi  i*th  •*  ir  bk*ii»  itiif.        t^a  » 
IdfrHt-IIUAUT?  KMSTOffV  A«t1.  cwk*a*,  imi  mtimiii^    ivm*  ii«rii.      CCJl    . 

isfr  ^«ooo   RiCTiriiRf  riMAM  Hti*«.  flM>  HHtirf*.  SO  t»  jQwiv.     zAit 

&a  AMtAL  fLfCTftOS.  ttil   itiAltHifl,  tslts,  HfliH.  Wwt  *  bwr!'    ■  Ul'     ^ 

S-tJflCLDEO  AuOiOCAU.ll.  2  ttrn*..  «it1i  RCA  pt«ci  t1  vtiit  *<t4 

aOO-PC-SCtHCON  SPfCIAL,  ttti'trd  tiifilt  flf  cU  $vv**.  Un|«ii#d 

300-PRf  FDRMEE     .  WArrCRS,   D«p44i1|r  v.tu^i.  ««■#  S  A   lOl^n 

JD  SCRa  A   TRIAC&.   iii-tirtiri  fraluv*.   10  Amp  TO  ZIQ.  urtUfttad, 

25  tiNr  SLIDE  ^WltCH.  <H<i\t   1/7     cuDb.  SPDt.  PC  l««di,      •milHi   ...... 

40  EDGE  CaNNLCTOHS,  ai*t    t  A  fi  pift.  3-t(dfed.  p^  fti*,     "*i^4i 

A  JHINt  MOTORS,  tvn*  PEsn.  1  a  fi  VDC.  t^kf  cait*d  mat  l*«di.     AT  Li 
24  HINt  RJLB^.  »«lt.  v4illa|;«i  A  b«*C  itrlei,  lom*  C0»«r4d,  ,    a797' 

40-&TnAI«l  RELltFjl.  «itt.  i^ptt,  itvi*>,A  tmai.   j^^JSAi 

fi-TIHt  0£<LAtrS.  leiliU  ilMtt,  «iit-  rrom  4»  mSac  Is  t  S«c.  IviTlBl  . ,  .  , 

3  HEAVY  D^UTV  AUTO  CHOKI,  llHtn   II  VDC        3A.  eptn  fr*n<*.    "^710, 
ID  SiK  CO-HTRQLS^,  Ihumbwh^iiiM^p*,  Krii|:l*  turn:.  KPii    nnl.   hiTOil 

4  CHROME  PLAtED  4LARM   SWITCH,  ipil,  HC.  mDm»nlBr^,     I'tTAt! 
i-LCP  LAMPS,  2V  r*d  I.ED  I'll  chroma   col^rrTit  ■biambly,.  */h*P(|lir«rA,  T.fjffijfj. 

B  flAR  LIGHTS,  {;>Ai<P  on  LCD  rhi^,   |  |i- J  volU.  wMa  tfl>dfe.   '-IlUi    

4-TAPE  NLA  PS,  TBCuriJ-pMr.  ilarr*  A,  mMa.  •'p1u|«.   U     liait.   ^"4973 


2.» 

],»« 
1,98 
Z,B9 
Z.«1 
2_BB 
Z  SI 
X.99 
JM 

IS* 

1.99 
£.99 
I-W 
3.99 
2.*9 


400  for 
30  fvr 
SO   f«r 

130  Tio-r 
S4  foF 

iOO    IQP 

40  tbk 

lOO   Iab 

40   ■«!' 

40  1«r 

ISO    1*1 

9   t4l 

JOO   *mt 

SO0  f*i 

H#  *** 

m  f## 

1«  ra« 

20  ta*' 


Ml} 

«1«r9il, 
434«' 


3i3«Oi 


I   T  1    t    t-  1   -r  n 


+-•-'1  -t  +  *  *.■+■  + 


3-t» 
i.*t 
J.ft 
2.9» 
3Lt* 
2-f» 
i-i* 

1.99 
7.19 

J*9 

|.!J9 
J.QO 
X,9B 
2.90 
Z.Q9 
1.94 
^.t« 
3,H 
I.94 

2.99 


«a  l*r 


toe  laf 

leo  i*# 

«  i*t 

440  tm 

H  l«f 

to  l«r 

13  Iqi 

4t  l^i 

BO  f4r 

13  l«r 

r»  l4ir 

20  Ifti 

B  loi 

t«  !«' 

lA  tmt 

a  lar 

to  Iw 


13 

13 
13 
»3 
»3 
13 
13 
IJ 
SJ 
S3^ 
is 

II 

fl 

*J 
11 
*3 
*J 

%3 
if 

11 
11 

M 
11 
U 

13 
13 

13 
11 

13 
13 
13 
13 
13 
13 
13 
il 
13 
13 
13. 


pcnnr 

Buy  One  $2.99er, 

Get  2nd 

(sanr>e  cat  no.) 

For  1  Penny  More! 


OROERING 

iNSTRUCTlONS 

m  Qfmck  boxea  m  front  gf 
2J99efs  desired 

•  indicate  OTY  Desired  Oo 

Lin«  To  LetT  01  Box 
■  Complete  coupon  sect  km 

•  Cut  out  ad  along  dotted 


line  and  mall  (o: 

Poly  Pok/ 


ftj 


P.O.  BOX  942  73  IZ 

SOUTH  LyNNFIELD, 
MA.  01940 


Send  For  Our  FREE  Catatog  Today! 

FcBturirtE  icni^tioilll  savings  on  Comfiutrr 
Ptrlpherals,  Speaktri^  Trsniformeri*  Solar  Pro- 
ducts, fins.  Stereo  Cguipm«nt,  Relays,  mnd  m  wide 
iraH«tr  Of  ether  divert*  «l«ctronic  compofi«nH. 
Tih*  ■drantas^  of  our  2S  y«ars  ai  Amertca's 
Id  rem  est  supplier  of  discount  electron  ies. 


Tota*  Amounl  O*  Or^ef  S 

Please  Add  O  tor  Postage  &  Handlm^} 


NAME 


ADDFIESS 
CITV 


STATE 


For  Faster  Service 
Order  8y  Phone 

1-617-245-3828 


n 


^■JV^      ^^,^, 


•  ^J 


Enclosed  is        CHECK,  MONEY  ORD€R 

Charge  my  .     MASTERCARD      ..  VISA 

ACCT.  « , EXP,  DATE 

S0nd  m»  yoc/r  FREE  cstafog 


1^  Re^d&r  SetyiG^s^e  page  226 


73  Magazine  •  December,  1980     89 


Internationars  TV-430()  is  a  high  performance  satellite 
receiver  that  tunes  all  channels  within  the  3  J  —  42  GHz 
band.  Standard  dual  audio  output  provided  at  6,2  and  6.8 
MHz.  Others  available. 

The  TV-430C  is  a  fully  packaged  and  assembled  receiver 
complete  with  a  built-in  LNA  power  supply,  built-in  AFC/ 
tuner,  control  circuitry  and  power  eable.  Al!  output  levels 
compatible  with  video  monitor  and  VTR  input.  Easy  to 
use!  Simple  tuning! 


Select  These  Options  ,  •  •  • 

Remote  tuning  control  , . 

Six  frequency,  crystal  control, 
audio  with  stereo  output. 
(Factory  installed  6.2  and  6.8  MHz 
crystals  supplied) _ 

Other  audio  frequency  crystals 

Model  TV-4300A  ,  ,  .  supplied  with 
remote  control  and  six  frequency, 
crystal  control,  audio  with 
stereo  output  . . , , . , 


$99,50 


»    T    '    .    .    -f 


$89.50 
$9.50  ea 


■V   «   I   I 


$1,149.00 


CMA*l«E''___  .  ^ 


Write  for  information. 


OEDuD 


^36 


INTERNATIONAL  CRYSTAL  MANUFACTURING  CO..  INC. 
10  N  Lee,  Oklahoma  City,  Oklahoma  73102,  405-236-3741 


90     73  Magazine  •  December,  1980 


ATTENTION  HAMS! 

Earn  a  "FREE" 

Antenna,  Tower 

or  BOTH! 

If  you  are  employed  by  a  company 
that  could  use  a  high  lift  work  plat- 
form, as  shown  below,  you  may 
earn  a  new  antenna  system  FREE 


With  today's  inflationary  times, 
this  may  be  the  perfect  opportunity 
to  upgrade  your  station  with  no 
drain  on  the  family  budget. 

Contact  Jerry  Fiatt  at  WILSON 
SYSTEMS  for  the  details  on  this 
offer ...  call  Toll  Free  {800}  634*898. 


W  S  I 


WILSON 

SYSTEMS,  INC. 


4286  Polaris  Avenue 
Las  Vegas,  Nevada  89103 

(800)  634-6898 


Rm- your  TRS-80 


'"^rpjl 


*r'' 


cw/Htty 


1 1  i 


V. 


■  I 


ff^i' 


AwcftoftioigQg 


*ic,.     .      ^ 


FEATURES 

"Auto  Send  «  Retieive  RTTV  ft  CW 
Connecfs  io  TRS  aO  Uset  Poff 
S  Key    h^ad  phone  lacK^ 
!0  message  rriemoNes  255  c^*^'  ea 
Uses  buiilin  PLL  or  eniemai  TU 
Ifkcfudes  hardware,  cassette  S  manyal 
Morse  TufOf lai  10  lessons  corrects  misia*(es 
^   -     '7 St  tasiesi  turay  lo  learn  me  code 
Mu?seprachc&fafidom5  lefref  *ords 
Auto  numD*?f  mg  confest  xeycf 
Interactive  QrapT»>CS  tMSlOt"  PI  X 
Autoiransmiiief  conirol  PTT 
Requires  L^tf^i  II  Basic  A  16K  RAM 

IftS-SO  is  a  rtcognirtd  fr  odtmort  of  Jonot  Cor  pororion 


Write  or  call 

for  complete  catalog 


Mao  SotFware.  PC  Board  Manual  St 49 

CMaO  A&  above  m  Cabmel  ^379 

TMBO  As  above  plus  demodulator  ft  AFSK  $^99 

MSOO  Adds  advanced  RTTY  lo  Ma«3    CM80  '  TM80  S99 


S^ 


vs 


«^e 


ft^ 


^10 


*^ 


.^ 


llCSjnc.® 

1125  N  Golden  State  Blvd  /  Suite  G 

Tuflock.CA  95380  (S) 

(209)  667  2888  /  634  8888       *^« 


t^^<iY$150 

*      (S100withW600  Tmdein  ) 


GkltOfytlliOpiu»  OTK 


iD*Sft*« 


k/S4 


Wff  «r0  *jrp«r/«ncMg  tetophont  dtfficultms,  pimaso  kfop  trying,  CaJtiDfno  reSK^niS  Add  6'f»  Ui^ 


ASTROIU  POWER  SUPPLIES 

•  HEAVY   DUTY  •  HIGH   QUALITY  •  RUGGED  •  RELIABLE  * 


SPECIAL  FEATURES 

•  SOLID  STATE  ELECTRONICALLV  REGULATED 

•  FOLD-BACK  CURRENT  LIMITING  Protects  Power  Supply  twm 
excessive  curfont  &  contiguous  shoried  oulpni 

•  CROWBAR  OVER  VOLTAGE  PROTECTION  on  Modflls  RS-7A. 
RE-12A,  RS  ?0A,  RS-35A,  RS?OM  &  RS'35M 

•  MAINTAIN  REGULATION  ft  LOW  RIPPLE  at  low  line  input  Voltage 
.  HEAVV  DUTY  HEAT  SINK  •  CHASSIS  MOUfttT  FUSE 

•  THREE  CONDUCTOR  POWER  GOfiO 

•  Of^E  VEAFl  WARRANTY  •  MADt  fN  U  S  A 

•  VOLT  ft  AMP  METER  ON  MODELS  RS20M  ft  RS-:iSM 

FEftFORMANCE  SPfClFICATrOMS 

•  INPUT  VOLTAGE  105  ■  125  VAC 

•  OUTPUT  VOLTAGE  13  &  VOC  ♦0  05  vollS 
(imernsll^  Adjustable:  11-15  VDC) 

•  RrPPlE  L&ss  than  Smv  ptak  to  peak  {full  toad  $  low  lintl 

•  RfGULATlON    '  05  volis  iw  loacJ  (0  tuK  load  ft  lo*  Ime  to  high  rme        Prica 
Qltitr  po^ulif  POWER  SUPFitlS  ilia  ivallibll:  |Safii«  le^lufe^  artu  specifications  ss  Bhovt) 


ASTflOWZtJ  AMP  REGULATED 
POWER  SUPPLY  Model  RS^OM 

16  Amps  contmuOUS 
20  Amps  JCS* 
S'iHJ^riW)  •  I0,5"CD) 
Shrpping  Weight  20  lbs 


Modil 

Conflnuoui 
Duty  {imps} 

ics- 

(imptj 

Stittfln  ) 
If  X  W  X  D 

Shipping 

Prici 

RS^35M 

2S 

35 

5X11X11 

29 

1167  95 

RS-35A 

25 

35 

5X11  X11 

29 

S149.95 

HS  20A 

15 

20 

5X9X10VJ  i 

20 

f99.95 

flS-t2A 

9 

t? 

47?  X  8  X9 

13 

174  95 

RS-7A 

5 

7 

3yiX6'/iX9 

a 

SS4  95 

RS'4A 

3 

4 

3Vi  X  6'/i  X  9 

5 

S39.95 

•|CS  —  Intermsttent  Commumcation  Service  (50"^  Duty  Cycle) 
t(  Ml  ivaHibli  It  ypur  l^ciJ  tfeiltf.  pleue  wnud  ui  diredly. 


Inside  View  —  RS-12A 


/Z 


CORPORAT 


2852  Walnut  Unit  E 
Tustin,  CA  92680 
lOlM      (7MI835-0MZ  *'»» 


You  cant 
tell  the  players 

without  a 
scorecard! 


Order  today! 

NEW  1981 

RADIO  AMATEUR  CALLBOOKS 

READY  DECEMBER  Istr 

Trie  latest  editions  will  be  published  soon! 
World-famous  Radio  Amateur  CallbooKs, 
the  most  respected  and  complete  listing  o1 
radio  amateurs.  Lists  calls,  llcerise  classes, 
address  Inlormation.  Loaded  with  special 
features  such  as  call  changes,  prellxes  of 
the  worldfStandard  time  charts, world-wide 
Q5L  bureaus,  and  more.  The  Li,S, Edition 
features  over  400,000  listings,  with  over 
100,000  changes  from  last  year.  The 
Foreign  Edition  has  over  300,000  listings, 
over  90,000  changes*  The  new  19S1 
Call  books  will  be  available  on  December  1, 
1980.  Place  your  order  now. 

Each      Shipping      Total 


LiUSG^IIDoOk 

Q  Foreign 

Cattbnk 


S17.95    $2.55    $20.50 
$16,95    $2,55    $19,50 


Order  both  books  at  the  same  time  lor 
$37,45  Including  shipping, 

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^■^^^^^^^^ 

Order  from  your  dealer  or  directly  from 
the  publisher.  All  direct  orders  add  $2,55 
for  shipping,  Illinois  residents  add  5% 
laies  tax, 

SPECIAL  LIMITED  OFFERI 
Amateur  Radio 

Emblem  Patch 
only  $2.50  postpaid 

Pegasus  on  blue  tieJd .  red  lettering  3  "  wide  k 
3 "  high  Great  on  jackets  and  caps  Sorry,  no 
call  letters  mUEn  TODAY! 


^61 

JiAOfO  AMATEUR 


llbook 


INC. 


Dept-     B 

925  Sherwood  Drive 

Lake  Bluff,  IL  60044,  USA 


1^  Reaa^r  Service — s*©  pap^  226 


73  Magazine  •  December,  1980     91 


Steven  D  Katz  WB2WIK 
24  Loui^  Drive 
Budd  Lake  Nj  07328 


HV  Power  Rectifiers 

amplifier  builders  should  read  this  one 


I 

Hams  seem  to  have  a 
propensity  for  using 
general-purpose  techniques 
in  specialized  applications- 
For  example,  a  fellow  may 
try  to  use  an  inch-and-a- 
quarter  TV  mast  to  hold  up 
his  TH6DXX  beam  because 
it  is  the  only  size  that  fits 
through  the  bearing  in  his 
tower.  Lousy  reason  . .  ,  and 
the  result  will  be  a  perfectly 
good  antenna  strewn  about 
his  yard  after  the  first  real 
windstorm.  Another  ham 
may  use  an  RG-58/U  feed- 
line  to  connect  up  his  kW 
on  two  meters;  after  all,  it 
handled  the  power  just  fine 
on  75.  See  my  point? 

One  mistake  hams  nearly 
always  seem  to  make  is  to 
use  low-voltage  technology 
applied  to  high-voltage  cir- 
cuits. This  approach  falls 
well  in  line  with  the  mast 
and  coax  examples  above, 
An  amateur  who  designs  his 
new  kW  plate  supply  using 
a  long  string  of  1 N 4000- type 
plastic  rectifiers  is  making  a 
mistake  which  likely  will  re- 
mind him  of  his  error  just 
when  he  begins  calling  that 
F08! 

There    are    different 


technologies  currently  em- 
ployed by  the  manufac- 
turers of  silicon  power  rec- 
tifiers, and  only  a  few  lend 
themselves  to  high-voltage 
applications.  The  always- 
available  "1000-piv,  1-A'' 
plastic  diodes  you  find  at 
flea  markets  and  on  retail- 
ers' shelves  — usually  priced 
at  15?  each  or  so  — just 
aren't.  Aren't  1000  piv  or  1 
A,  that  is.  These  cheapie 
products  nearly  always  are 
high-leakage  commercial 
devices  with  weak  reverse 
''knees"  (VR/lg  characteris- 
tics) and  limited  surge 
capabilities.  After  all,  if 
these  diodes  were  so  good, 
why  wouldn't  their  source 
sell  them  to  high-reEiability 
industrial  houses,  where  the 
demand  is  high  and  supply 
is  short,  for  much  higher 
prices?  Reason  is,  the 
manufacturers  of  these 
cheapie  devices  know  the 
value  of  their  product:  near- 
ly zero. 

A  ham  may  build  just  one 
kW  amplifier  in  his  lifetime; 
he'll  Sook  everywhere  for 
Eimac  tubes,  Jennings  tun- 
ing capacitors,  Dow-Key 
relays,  and  the  like  — all 
high-quality  products.  Why 


endanger  the  usefulness  of 
this  major  investment  by 
using  scrap  power-supply 
components? 

I  have  seen  rectifiers 
which  were  marked  "1500 
piv,  2,5  A"  for  sale  at  a  local 
electronics  retailer  priced 
at  6  for  51.00.  Hmmm.  I 
looked  at  them:  They  mea- 
sured 0.125"  in  diameter, 
were  0.250"  long,  were 
made  of  plastic  (epoxy),  and 
had  plated  copper  leads.  1 
purchased  12  of  these 
gems  and  made  a  few  mea- 
surements on  them  when  I 
brought  them  home.  The 
very  best  diode  of  the  lot 
"broke  down"  (exceeded 
100-uA  reverse  current)  at 
slightly  over  700  volts.  In 
the  forward  direction,  at  2.5 
A,  they  averaged  1,3  volts 
forward  drop.  This  repre- 
sents 3,25  Watts  of  power 
(itssipated  in  only  one  direc- 
tion. Add  in  the  100  uA  of 
leakage  at  700  volts  in  the 
other  direction  (70  mW)  and 
we  fmd  that  this  diode 
would  have  to  dissipate 
3.32  Watts  minimum  in  a 
700-V  ac  application  — an 
awful  lot  of  power  for  a 
device  the  si^e  of  a  M-Watt 
resistor. 


len  you  consider  that 
these  devices  are  soldered 
together,  i.e.,  the  leads  are 
formed  tike  nail-heads  and 
soldered  to  the  metallized 
silicon  die  inside  the  diode, 
it  becomes  very  evident 
that  the  overall  reliability 
of  a  device  of  such  small 
volume  dissipating  over 
three  Watts  of  power  is 
questionable.  Have  you 
ever  touched  a  Vx-Watt  re- 
sistor which  was  actually 
dissipating  one-half  Watt? 
Ouch\ 

Another  limitation  of  the 
soldered-together  ap- 
proach is  surge  current 
capability.  Ever  turn  on  a 
piece  of  gear  which  im- 
mediately blew  a  fuse? 
Often,  it  is  the  power  rec- 
tifiers which  blew,  from 
surge  or  tnrush  current.  In  a 
typical  power  supply,  the 
rectifiers  charge  a  capaci- 
tor which  represents  a  very 
low  impedance  at  the 
operating  frequency  (in  a 
line-operated  system,  this  is 
60  Hz  for  half-wave,  120  Hz 
for  full-wave  designs). 
Before  the  capacitor 
charges  up  to  its  working  dc 
potential,  it  may  look  like  a 


92     73  Magazine  •  December,  1980 


Tomorrow's  Technology  -Here  Today ! 


THE  YAESU 
FT-207R 


The  "horse-and-buggy  days  of  crystai-controlled 
handles  are  gone!  Yaesu's  engineers  have  har- 
nessed the  power  of  the  microprocessor,  bringing 
you  800  channels,  digital  display,  memory,  and 
scanning  from  a  hand-held  package.  Only  with 
Y^su  can  you  get  these  big  performance  fea- 
tures in  such  a  compact  package. 


BNC  Amenna  Connector 


SqueTcti  Control  and 
Tone  Squelch  On/Off 


Audio  Gain  Control 


4  bit  CPU  chip  for  frequency  control. 

Keyboard  entry  of  all  frequencies 

Digital  frequency  display. 

800  channels  across  144-148  MHz. 

Up/Down  manual  scan,  or  auto  scan  tor  busy/clear  channels. 

10  kHz  scanning  sleps^ 
Five  channels  of  memory 
Pnority  channel  with  search-back  feature. 
Keyboard  lock  to  prevent  accidental  frequency  change. 
Memory  backup 

±  600  kHz  or  odd  repeater  splits. 
Display  ON/OFF  switch  for  battery  conservation. 
Equipped  wrth  rubber  flex  antenna,  wallmount  batteiy  charger. 

earphone,  shoulder  strap,  and  belt  clip- 
Switchabie  RF  output  2,5  watts  (minJmum)  or  200  mW 
Earphone  for  pnvate  listening 
2  Tone  (ToLKchtone' )  Input  ffom  Keytx>aJ"d 
High^  reliable  LED  frequency  display  (works  in  cokj  temperatures 

and  does  not  fade  with  age) 


Cleer/Busy  Auto  Scan  Selector 
Earphone  Jack 
^ —  Repeater/Slfnpfex  Offset  SwHctt 

\ 

—  Remote  Speaker/Mike  Input 


T 


Condensor  Mike 


4-Diglt  LED  Readout 


Keyt>oard  Entry 


Keyboard  Lock 


SPECIFICATIONS: 

GENERAL 

Fr«qiierK:y  coverage:  144^146  MHz 

Nunber  of  cKannels:  BOO 

Emtsston  type:  F3 

Batteries:  NtCd  battery  pack 

Vottage  requirement:  10,6  VDC 

1 10%,  maxjfTttjm 

Currertt  consumption: 

Reoerve:  35  mA  squelched  (150 
mA  unsQueidhed  with  maianium 


Channel  Busy  Lamp 


Transmit  Indicator 


Priority  Channel 


DIspTay  On/Off 


^  5  kHz  Up 


RKEIVER 


HKLow  Power  Svvttch 
(Bottom  of  Case) 


Transmrtr  800  mA  (fuli  power) 

Caae  dimafialons:  6Sx  t0t  xS4  mm 

(HWO) 
WeigM  (wHh  batterlM):  660  gmm 


ClrcuH     type:     Double     conversion 

superhertefodyrve 
Entermediate  Irequendes, 

2nd  IF =455  kHz 
Ser^ltlvlty:  0,32  uVfor20dBquftetfr>g 
Seiectivtty:  1  7,5  kHz  at  60  dB  down 
Audio  Output:  200  mW  ai  10%  THD 

Pnce  Afxj  SpecilicarK>ns  Sirfsject  To 
Clian^  Without  Noitce  Or  Obligatron 


TRANSMITTER 

Power  Output:  2.5  watts  minimum  /200mW 

Dwfatiorr:  '^  5  kHz 
^jurious  radiation:  - 60  dB  or  better 
Mk^ophor^er  Condenser  type 

(2CXX)  ohms) 

OFFIONS 
LC-C7  Leather  Carying  Case 

YM-24  Remote  Speaker/Mjcrophon© 
Tone  Squek:h  Unit 


W 


TheraiffOM 


ISO 


YAESU  ELECTRONICS  CORP.,  6851  Walthali  Way,  Paramount,  CA  90723  •  {213}  633-4007 
YAESU  ELECTRONICS  Ea»t«m  Service  Ctr.,  9612  Princeton-Glendale  Rd.,Cincmnatr OH  45246 


dead  short  drawing,  for  the 
first  few  cycles  of  opera- 
tion, considerably  higher 
current  than  the  rectifiers 
can  withstand.  In  fact  it  is 
not  uncommon  for  (low- 
voltage)  computer-grade 
electrolytics  to  be  such  ef- 
fective shorts  that  they  at- 
tempt to  draw  several  hun- 
dred Amperes  of  inrush  cur- 
rent limited  only  by  the  re- 
sistance of  the  power  trans- 
former and  the  saturation 
effects  of  its  core.  This 
surge  current  may  be  a  hun- 
dred times  the  normal 
operating  output  current  of 
the  supply  and  can  cause 
rectifier  failures  in  an  other- 
wise sound  design.  The 
problems  caused  by  surge 
currents  are  numerous,  but 
one  may  be  solder  fatigue 
in  the  rectifiers:  The  solder 
bonds  soften  as  the  result 
of  prolonged  high-current 
operation,  then  harden 
when  the  power  is  removed. 
This  thermal  cycling 
weakens  the  bonds  and 
may  cause  a  failure. 

So  much  for  surge  cur- 
rents. How  about  ava- 
lanche characteristics?  This 
term  describes  the  manner 
in  which  the  silicon  junc- 
tion breaks  down  in  the  re- 
verse mode  (in  normal  line 
rectifier  applications,  this 
mode  occurs  at  a  60-Hz 
rate)  and  at  what  voltage 
the  junction  enters  break- 
down. Typical  double^dif- 
fused  junction  rectifiers^ 
the  most  common  type 
used  for  commercial  ap- 
plications, due  to  the  inex- 
pensive process  em- 
ployed—can be  built  easily 
to  block  500  volts  or  so  in 
the  reverse  direction. 

1000  volts  is  an  entirely 
different  story  and  requires 
higher-resistivity  silicon  and 
tighter  process  controls.  It 
has  been  my  experience, 
after  testing  many  lots  of 
devices,  that  most  "1000- 
volt"  double-diffused  parts, 
like  the  1N4007,  break 
down  well  below  their  rated 
1000  volts.  What  can  we 
do?  Sue  the  manuacturers? 
Nope.  You  see,  unless  one  is 


very  careful,  the  reverse- 
voltage  test  can  be  destruc- 
tive, and  most  manufac- 
turers accept  no  respon- 
sibility for  devices  which 
are  field-tested  unless  tight 
testing  controls  are 
employed  and  proven  ac- 
ceptable. 

Where  does  that  leave  us 
hams?  Holding  the  bag,  Tm 
afraid,  unless  we  deal  ex- 
clusively with  sources 
which  have  high  scruples 
and  specialize  in  high- 
voltage  technology. 

Even  if  the  rectifiers  used 
actually  meet  or  exceed 
their  rated  reverse  voltage 
specifications,  what  hap- 
pens if  they're  not  matched 
for  this  characteristic?  Ab- 
solutely nothing,  as  long  as 
no  one  diode  in  the  string  is 
approaching  breakdown  or 
avalanche.  We  can  assume 
that  even  a  poorly-made 
power  rectifier  in  the  one- 
to-three-Amp  region  prob- 
ably does  not  exceed 
10-20-uA  leakage  at  room 
temperature  if  operated 
well  betow  its  rated 
breakdown  voltage.  Except 
in  extremely  high-voltage 
(or  low  current)  applica- 
tions, this  represents  such  a 
small  amount  of  power 
(e,g,  500  V  X  10  uA  =  5 
mW)  that  it  is  not  worth 
worrying  about 

Equalizing  resistors 
wired  across  every  rectifier 
in  a  string  are,  therefore,  a 
waste  of  power  and  money 
and  create  an  additional  lia- 
bility in  the  system:  A  resis- 
tor could  fail. 

By  the  way,  the  tempera- 
ture coefficient  of  break- 
down voltage  for  a  silicon 
unction  is  positive  — the 
lotter  the  junction,  the 
higher  the  breakdown  volt 
age.  This  is,  of  course,  a 
positive  feature  of  a  silicon 
rectifier.  An  effect  to  con- 
sider, however,  is  the  in- 
crease in  leakage  current 
with  an  increase  in  junction 
temperature.  Silicon  de- 
vices double  in  leakage 
about  every  10°  C,^  and  in 
many  power-supply  appli- 
cations,  the  junction  tern- 


MAXIMUM   FORWARD  CURRENT  VS.  AMBIENT  TEMPERATURE 

700 

600 

"X 

ENVffiOMWENT             MULTIPLY  BY 

v^ 

—  DC 

i3 

\ 

OIL 

£.0 

-■   500 
IE 

> 

s 

FORCED   AIR   200  CFM 
FORCED  AIR   400  CFM 

1   5 

\  .7t 

V 

\ 

t 

.^   \ 

X 

FOfiCED  Alfi  6D0  CFM 

Z.Q 

£   400 

^S/N 

N.^x 

\ 

a 

/V\ 

X      . 1  ji  HALF  WAVt  OR 

/     \" 

nX 

FULL  WAVE 

^-^ 

^ 

NX^ 

< 

_l 

J  #  HftLF   WAVE  OR  ^  ^^ 

i.,,^^^ 

\Sv 

X 

X 

FULL  WAVE 

^""•^...^^^ 

\x 

V  X 

«    200 

i 

^""•"^^ 

XX 

x\ 

o 

100 

0 

Bfi   HALF  WAVt   STAR  - 

1 

x^ 

^ 

^ 

^ 

25 


50  75  loo  12:5  150 

FOR*AfiD  CURRENT    PER  LlG  VS.    AM&IENT   TEMPERATURE   ^C 


175 


Fig^  ^ 


peratures  will  exceed  100^ 
C;  often,  power  rectifiers 
will  exceed  100-uA  leakage 
at  this  temperature.  At  500 
volts  Vr,  this  is  50  mW,  not 
an  insignificant  value. 

Matching  rectifiers  for 
forward  characteristics  can 
be  important  since  it  is  in 
the  forward  — or  conduc- 
tion—mode that  the  rec- 
tifier will  be  dissipating  real 
power.  Fortunately,  most 
silicon  power  devices  buitt 
with  the  same  technology 
will  offer  similar  forward 
characteristics  — roughly 
one-volt  drop  per  junction 
at  rated  1^  and  25^  C.  The 
temperature  coefficient  of 
this  characteristic  is  nega- 
tive, i.e.,  the  hotter  the  junc- 
tion, the  lower  the  forward 
drop  at  a  given  current. 

Packaging  also  is  a  con- 
sideration which  will  deter- 
mine the  reliability  and  life 
of  a  silicon  rectifier.  Many 
inexpensive  devices  are 
cased  in  epoxy,  a  hard 
plastic  molded  around  the 
tiny  silicon  die  to  protect 
and  insulate  it  and  the 
fragile  lead  bonds.  Some 
diodes  use  a  glass  sleeve  to 
hermetically  seal  out  con- 
taminants which  would 
gradually  increase  surface 
leakage  of  the  silicon  and 
lead  to  a  failure;  some- 
times, the  glass  sleeve  also 
holds  the  leads  on.  This  is 
not  a   great  way  to  build 


power  semiconductors! 
Old-fashioned,  ''top  hat'' 
leaded  rectifiers  built  in 
type  DO-1,  DO-2:  and  DO-3 
cases  are  just  that:  old- 
fashioned  They  rely  on  the 
thermal  impedance  of  a 
soft-solder  bond  to  just  one 
side  of  the  silicon  die  to 
conduct  heat  away  from 
the  junction;  they  also  are 
"cavity''  devices,  whose 
characteristics  can  change 
as  the  result  of  mechanical 
shock.  Not  a  great  choice 
for  that  contest  rig  which 
gets  bounced  up  the  side  of 
a  rocky  mountain. 

As  this  discussion  relates 
primarily  to  ac-line-oper- 
ated  linear-type  power  sup- 
ply designs  (direct  conver- 
sion of  6O-H2  power  to  dc 
power),  we  have  inten- 
tionally avoided  the  subject 
of  switching  characteristics 
of  rectifiers.  These  charac- 
teristics, called  forward- 
recovery  and  reverse-recov- 
ery expressed  in  subsecond 
increments  (or  dv/dt  ex- 
pressed in  volts  per  time  in- 
terval, usually  us),  do  not 
normally  become  impor- 
tant until  operating  fre- 
quencies far  exceed  60  Hz. 
However,  a  considerable 
mismatch  in  t^.^  (reverse- 
recovery  time)  characteris- 
tics, especially  if  one  or 
more  diodes  in  a  string  are 
very  slow  to  recover  from 
forward    saturation,    can 


94     73  Magazine  •  December,  1980 


YOU  ARE  LOOKING  AT 

EVERYTHING 
THAT  IS  NOT  ON  SALE 

THIS  MONTH 

AT  HAM  RADIO  CENTER 


FOR  BEST  PRICE  -  FAST  DELIVERY 

CALL  TOLL-FREE 


«.>HAMRAQIQjCENC 

8340-42  OHve  Blvd.  •  P.O.  Box  28271  •  St.  Louis,  MO  63132 


^^$2 


1^  Reader  ServtcB — see  page  226 


73  Magazine  •   December,  1980     95 


cause  the  fastest  diode  in 
that  string  to  be  over- 
stressed  for  a  lengthy 
enough  period  to  cause  its 
deterioration  or  destruc- 
tion.^ It  is  wise,  therefore, 
to  use  at  least  medium- 
recoverv  rectifiers  — typi- 
cally  rated  2  to  5  us --in 
reliable  60Hz  power  sup- 
ply designs  where  the 
devices  are  used  in  series. 

So  far,  we've  discussed  a 
lot  of  '^don'ts": 

1.  Don't  use  long  strings 
of  low-voltage  rectifiers. 

2.  Don't  use  cheapie 
devices  whose  ratings  are 

nearly  always  overstated. 

3-  Don't  use  miniature  di- 
odes which  will  dissipate 
excessive  power  in  your  ap- 
plication 

4.  Don't  use  devices  with 
limited  or  unknown  surge 
current  ratings, 

5.  Don't  use  '1000-V"  di- 
odes at  this  rating,  but  oper- 
ate  comfortably  below 
their  V|^  capability  when 
using  in  series. 

6.  Don't  use  equalizing 
resistors— they're  just  a 
cover-up  for  having  select- 
ed the  wrong  semiconduc- 
tors for  the  job. 

7.  Don't  use  power  rec* 
tifiers  which  are  built  like 
small-signal  devices,  e.g., 
epoxy,  glass-sleeved  pres- 
sure-bonded, top-hat  axials, 
etc. 

8.  Don't  use  devices  of 
unknown  or  poor  reverse- 
recovery  characteristics, 
especially  in  a  series  string. 

Well,  what  should  we  do? 
Thought  you'd  never  ask. 

When  possible,  use  high- 
voltage  rectifier  assemblies 
manufactured  by  a  reliable 
power  rectifier  house, 
rather  than  building  your 
own  assembly  by  wiring  a 
string  of  discrete  devices  in 
series.  These  high-voltage 
assemblies  are  made  of  sev- 
eral rectifiers  in  series,  of 
course  — it  is  very  difficult 
to  manufacture  a  single 
junction  which  can  block 
much  over  1000  volts  suc- 
cessfully and  otherwise 
maintain  the  characteristics 
of    a    rectifier— but    the 


manufacturers  of  these  as- 
semblies are  much  better 
equipped  than  the  average 
ham  to  select  the  proper  de- 
vices to  use  and  then  mea- 
sure the  overall  results. 

A  conscientious  manu- 
facturer will  use  hermeti- 
cally-sealed, internal  heat- 
sink  devices,  which  are 
high-temperature  metallur- 
gically  bonded  (f^<?t 
soldered]  together,  then 
screened  and  selected  for 
characteristics  which  will 
allow  trouble-free  series 
operation,  before  assem- 
bling the  finished  product. 
This  may  sound  like  an  ex- 
pensive process,  but 
manufacturers  set  up  to 
build  such  assemblies  in 
large  quantities  can  do  so 
quite  economically.^ 

Calculate  the  piv  require- 
ment of  the  rectifier  or 
assembly  selected.  For  ex- 
ample, if  the  configuration 
is  a  fufl-wave  center-tap, 
each  rectifier  has  to  block 
2.82  times  the  rms  voltage 
of  half  the  transformer's 
secondary;  for  a  full-wave 
bridge,  each  rectifier  must 
block  1.41  times  the  rms 
voltage  of  the  transformer 
secondary. 

To  further  illustrate  the 
examples  in  the  last  para- 
graph, if  you  have  a  plate 
transformer  whose  sec- 
ondary voltage  is  2000  V 
rms  and  you  desire  to  use  a 
full-wave  bridge  rectifier 
circuit,  each  leg  of  the 
bridge  must  be  capable  of 
blocking  at  least  2000  x 
1 .41  =  2820  volts  with  each 
half  cycle.  This  assumes  a 
nominal  ac  line  voltage 
equal  to  and  never  ex- 
ceeding the  primary  volt- 
age rating  of  the  transform- 
er, this  also  assumes  that 
under  no-load  conditions, 
the  rms  voltage  delivered 
by  the  transformer  doesn't 
rise  above  its  full-load 
voltage  (transformers  are 
typically  rated  at  some  rms 
voltage  at  some  load  cur- 
rent, like  2000  V  at  500  mA). 
These  are  poor  assump- 
tions! 

Normafly,  a  transformer 


rated  at  1  kVA  (equivalent 
of  1-kW  resistive  power)— 
say,  2000  V  at  500  mA- wi!I 
rise  in  secondary  voltage 
under  no-load  conditions 
by  about  10%  or,  in  our  ex- 
ample, to  2200  V.  In  addi' 
tion,  it  is  not  uncommon  for 
ac  line  voltage  fluctua- 
tions to  swing  "upward" 
another  10%  or  so  — say, 
from  117  V  rms  to  1287  V 
rms— which  transforms  to 
2420  V  in  our  example  This 
would  require  a  rectifier 
bridge  rated  at  3412  V  per 
leg  as  a  minimum,  and  even 
this  value  does  not  include 
any  protection  factor  for 
short-duration  transients. 

So,  you  see  that  while  our 
initial  calculations  led  us  to 
believe  that  a  2800-piv  rec- 
tifier assembly  might  be 
used  in  each  leg  of  the 
bridge  described,  in  truth 
we  should  use  at  least 
3500-piv  assemblies  as  an 
absolute  minimum;  5000- 
piv  rated  assemblies  would 
not  be  overkill  to  afford  us 
some  protection  against  un- 
expected transients. 

Next,  estimate  surge  cur- 
rent requirements,  I  say 
"estimate"  because  there 
usually  are  unknown  fac- 
tors involved,  like  trans- 
former efficiency,  satura- 
tion effects  of  its  core,  and 
the  discharged  resistance  of 
the  input  filter  capacitor. 
However,  one  can  make  a 
worst-case  surge  current 
calculation  based  on 
transformer  secondary 
resistance.  If  the  resistance 
of  your  transformer  sec- 
ondary winding  is  20  Ohms 
and  the  secondary  voltage 
is  2000  V  rms,  the  worst- 
case  surge  current  is  Epi^/R 
(2800/20),  or  140  Amperes 

Actually,  the  surge  cur- 
rent will  not  be  quite  this 
high.  If  your  transformer 
secondary  winding  resis- 
tance measures  very  low  or 
your  input  filter  capacitor  is 
very  large,  you  may  wish  to 
add  some  series  resistance 
in  each  input  leg  to  the  rec- 
tifier bridge  to  act  as  surge- 
current  lim  iters. 

A  35-Ohm,  10-Watt  resis- 


tor in  series  with  each  ac  in- 
put to  a  bridge  as  described 
above  (2  kV  rms  secondary) 
will  limit  surge  current  to  40 
Amperes  maximum  while 
dissipating  only  8,75  Watts 
per  resistor  and  degrading 
power  supply  regulation  by 
about  1%.  A  compromise, 
surely,  but  not  a  bad  one; 
surge  protection  may  be 
switched  ''out''  iust  a  mo- 
ment after  turn-on  if  one 
wishes  to  conserve  power 
and  enhance  regulation 
during  normal  operation 

Next,  determine  the  con- 
tinuous operating  current 
requirements  placed  upon 
the  rectifiers  based  on  cir- 
cuit configuration  and 
operating  habits.  I  always 
design  a  power  supply  for 
continuous  duty  unless  size 
and  weight  restrictions  are 
a  consideration.  AM,  FM, 
RTTY,  and  SSTV  are  pretty 
much  continuous  duty 
modes.  SS8  and  CW  may  be 
low-  or  high-duty  cycle 
modes,  depending  upon 
voice  characteristics,  audio 
processing,  keying  charac- 
teristics, etc.  The  thermal 
time  constant  of  most  rec- 
tifier assemblies  in  the  low 
kilowatt  region  (say,  Vi  to  3 
kW)  is  very  short,  which 
means  the  rectifiers  will 
reach  operating  tempera- 
ture from  internal  heating 
rapidly  — probably  in  less 
than  one  minute  of  key- 
down  time.  Therefore,  just 
because  one  keeps  his 
transmissions  reasonably 
short  does  not  mean  that 
the  rectifiers  aren't  reach- 
ing their  operating  tempera- 
ture. 

Most  kW-region,  high- 
voltage  supplies  will  never 
have  to  deliver  more  than 
one  Ampere  dc  continuous. 
Those  folks  who  are  for- 
tunate enough  to  own  a  pair 
of  4-lOOOs  or  8877s  may 
wish  to  design  a  power  su|> 
ply  capable  of  delivering  2 
A  dc,  but  don't  brag  about 
this  on  the  air.  lest  the  FCC 
wonder  why  you  need  such 
a  big  supply! 

In  a  full-wave  circuit, 
each  rectifier  conducts  for 


96     73  Magazine  •  December.  1980 


* 


f 


9 


I 


CENTRAL  NEW  YORK'S  LARGEST  HAM  DEALER 

HOLIDAY  SALE  DAYS 

YOU  MIGHT  BE  ABLE  TO  BEAT  OUR  PRICES  .    .    . 

"  .  .  .  BUT  YOU  WON'T  BEAT  OUR  SERVICE 


Season's  Greetings 
From  Our  Staff 

Warren /K2IXN 
Bob/WA2MSH 
Alan/WA2MSI 
Norman /K2KLV 
Jack/WB2LCP 
Chuck/WA2GJN 
Bev/  K2TPE 
Val/KA2GNA 


^ 


YAESU 

LAND/MOBILE 

DISTRIBUTOR 


ICOM 

IC720 


ROqOT 
800 


YAESU 
FT-101ZD 


YAESU 
FT207R 


KENWOOD 
TS*830S 


KENWOOD 
TS-t30S 


'^tm 


KENWOOD 
DM-81 


YAESU 
FT-r07 


ALPHA 

76A 


DRAKE 
TR7'DR7 


All  Sales  Over  $750.00  Will  Entitle  You  To  A 
FREE  1981  Callbook  Until  December  31  St. 


OUT  OF  STATE 
CALL  TOLL  FREE 


800-448-9338 


Featuring  Kenwood,  Yaesu,  Icom,  Drake,  Ten-Tec,  Swan,  Dentron,  Alpha,  Robot,   MFJ,  Tempo,  Astron    KLM 
Hy  Gam,  Mosley,  Larsen,  Cushcraft,  Hustler,  Mini  Products,  Bird,  Mirage.  Vibroplex,  Benciier,  info-Tech,  Universal 
Towers,  Caiibook,  ARRL,  Astatic,  Shure. 

\NE  SERVICE  EVERYTHING  WE  SELL! 
CALL  FOR  A  QUOTE  .  .  .  YOU  WON'T  BE  DISAPPOINTED 

We  are  just  a  few  minutes  off  the  NYS  Thruway  (1-90)  Exit  32 


Warren 
K2IXN 


ONEIDA  COUNTY  AIRPORT  TERMINAL  BUILDING 

ORISKANY,  NEW  YORK  13424 

N.Y.  Res.  Call  (315)  337-0203 


Bob 
WA2MSH 


only  half  the  input  wave, 
and  therefore  must  handle 
only  half  the  dc  output  cur- 
rent. Even  a  two-Amp  sup- 
ply can  be  built  using  rec- 
tifiers rated  at  one  Amp  Iq 
(continuous  output  cur- 
rent), as  long  as  the  rectifier 
rating  is  compatible  with  its 
operating  temperature.  It  is 
wise  to  assume  that  under 
some  conditions  the  rec- 
tifier junction  temperature 
will  be  at  least  100^  C.  This 
may  sound  very  hot  (and  it 
is,  for  human  beings),  but 
silicon  power  rectifiers  nor- 
mally work  in  this  region 
and  they  don't  mind,  as 
long  as  one  derates  them 
properly.  The  derating 
curves  for  one  popular  kW- 
ievel  rectifier  assembly  are 
shown  in  Fig,  1,"^ 

As  you  can  see,  the  sin- 
gle-phaSe,  full-wave  current 
rating  for  this  assembly  is 
500  mA  from  25°  C  [77^  F} 
to  about  55^  C  {131^  F); 
then  it  derates  in  a  nearly 
linear  fashion  to  zero  cur- 
rent at  175 '^  C  [347°  F).  This 
represents  a  derating  factor 
of  about  4.17  mA/°C  (2.31 
mA/°FX  calculated:  Kl^ 

T^}  -  (1q  @  TmaJ]/(l"max 


TJ  Amps/degree,  where  Iq 
is  rated  output  current,  T^  is 
ambient  temperature  (usu- 
ally 25  or  55°  C)  and  Tmax  "s 
the  maximum  rated  temper- 
ature  of  the  device  or 
assembly. 

At  100°  C,  then,  the 
''500-mA"  rectifier  assem- 
bly shown  is  actually  rated 
at  about  312  mA;at125'^C 
It  is  rated  at  about  208  mA. 
Operating  temperature 
equals  ambient  tempera- 
ture plus  thermal  rise  from 
junction  heating  and  is 
sometimes  difficult  to 
calculate.  To  allow  margin 
for  error,  it  is  best  to  use 
assemblies  rated  for  your 
actual  operating  current  at 
some  rather  high  tempera- 
ture (tike  100°  C). 

It  is  wise  to  take 
manufacturers'  data  sheet 
ratings  Uterally  and  not  ex- 
ceed them.  Note  that  the 
temperatures  expressed  in 
Fig.  1  are  ambient,  for  free 


Peak 

Maximum 

One 

Inverse 

Average 

Forward 

Cycle 

Reverse 

Type 

Voltage 

Rectified 

Voltage 

Surge 

Current/Leg 

Case 

No. 

Per  Leg 

Current 

@500  m A/Leg 

Current 

@  PIV 

Length 

SS^C 

55*^C  Mtg. 

25°C 

55^0 

25°C 

A 

Volts 

Amps 

VoUs 

Amps 

uA 

Inches 

SDHSKM 

5kV 

1.0 

7 

50 

1,0 

3.36 

SDH10KM 

10  kV 

1.0 

14 

50 

1.0 

3.36 

SDH15KM 

15  kV 

1.0 

20 

50 

1.0 

4.04 

*SDHC5KM 

5KV 

2.0 

7 

50 

1.0 

4.72 

SDHDSKM 

5kV 

1X 

7 

50 

1.0 

4.72 

*SDHC10KM 

10  kV 

2.0 

14 

50 

1.0 

4.72 

SDHD10KM 

10  kV 

1.0 

14 

50 

1.0 

4J2 

*SDHC16KM 

15kV 

2,0 

20 

50 

1.0 

6.09 

SDHD15KM 

15  kV 

1.0 

20 

50 

1.0 

6.09 

air.  There  is  a  multiplier 
table  shown  which  reveals 
that  the  current  rating  for 
this  assembly  is  substantial- 
ly higher  if  external  (oil  or 
forced-air)  cooling  is  in- 
troduced, as  is  often  the 
case  in  industrial  or  military 
designs. 

Another  consideration  is 
insulation  resistance  across 
high-voltage  terminals  or 
from  them  to  ground.  At 
working  voltages  normally 
encountered  in  amateur 
amplifiers,  even  big  ones, 
this  is  not  a  real  problem, 
since  most  of  us  are  work- 
ing below  5  kV,  A  good  rule- 
of-thumb  dimension  for 
high-voltage  spacers  or 
standoffs  used  to  mount 
rectifiers  and  other  high- 
voltage  components  is 
0.10"  per  1000  volts 
minimum. 

The  same  rule  holds  true 
for  package  length  of  high- 
voltage  rectifiers.  Beware 
of  a  M''-long  diode  rated  at 
"5  kV."  The  silicon  junc- 
tions inside  may  not  break 
down  until  that  level  is 
reached,  but  what  about 
the  package  itself  or  the  air 
around  it?  Many  subminia- 
ture  high-voltage  rectifiers 
were  designed  to  be  used  in 
dielectric  oil  or  fluorocSr- 
bon,  not  in  air,  and  should 
be  avoided  for  amateur  ap- 
plications. 

Silicon  high-voltage  rec- 
tifier assemblies  are  avail- 
able as  complete  center- 
taps  and  bridges  as  well  as 
half-wave  devices.  In  fact  it 
is  a  good  choice  indeed  to 


Fig.  2. 

use  a  commercially-manu- 
factured complete  rectifier 
assembly  (such  as  a  full- 
wave  center-tap)  when  eco- 
nomically  feasible,  since 
the  manufacturer  has  used 
well-matched  devices  there- 
in, ensuring  good  balance 
and  long  life.  A  typical  full- 
wave  center-tap  high-volt- 
age rectifier  assembly  data 
sheet  is  reproduced  in  part 
here  (Fig,  2^)  as  an  example 
of  a  readily-available  in- 
dustrial product  and  its 
ratings.  The  SDHC-prefix 
devices  asterisked  are  the 
center-tap  assemblies  and 
are,  therefore,  rated  at 
twice  the  dc  output  current; 
the  SDH"  and  SDHD-prefix 
devices  are  half-wave  di- 
odes and  voltage-doubler 
configured  arrays.  [A  dou- 
bler  is  two  rectifiers  in 
series  with  the  center 
anode-to-cathode  connec- 
tion brought  out  for  con- 
nection to  external  high- 
voltage  capacitors.)  Note 
the  Vp  — forward  voltage  — 
specified  for  each  assem- 
bly; this  is  a  clue  to  the 
number  of  junctions  con- 
tained in  each. 

This  discussion,  lengthy 
as  it  is,  leaves  out  much  in- 
formation; it  is  important  to 
nbtfe  that  many  of  the  rules 
outlined  here  do  not  apply 
to  low-voltage,  high-current 
designs.  If  there  is  enough 
interest  generated  by  this 
article,  I  will  follow  up  with 
articles  on  p-n  power  semi- 
conductor  junctions,  as- 
sembly techniciues,  thermal 
impedance  ratings,  switch- 
ing power  designs,  etc. 


In  the  meantime,  most 
amateurs  who  have  ab- 
sorbed the  material  pre- 
sented here  should  have  a 
better  understanding  of 
high-voltage  power  recti- 
fiers and  their  applications 
and  ratings.  Next  time  you 
look  inside  a  kW  amateur- 
band  amplifier,  see  what 
type  of  high-voltage  rec- 
tifier system  is  used.  It  can 
tell  you  a  great  deal  about 
how  smart  the  amplifier's 
designer  was,  ,  and  how 
much  he  cared  about  build- 
ing a  reliable  product.B 

References 

1.  W.  Shockiey,  "Problems  Re- 
lating to  p-n  Junctions  in  Sill- 
con/*  Sofid  State  Ef&ctronics, 
vol.  2,  c.  1961. 

2.  H,W.  Henkel,  "Germaniunn 
and  Silicon  Rectifiers,"  Pro- 
ceedings of  the  LR.E,,  vol.  47,  c> 
1958. 

3.  Semtech  Corporation,  652 
Mitchell  Rd-,  Newbury  Park  CA 
91320.  Examples  of  construc- 
tion and  design  technology 
used  here  are  taken  from  ideas 
used  In  Semtech  products.  Oth- 
er manufacturers  of  htgh-volt- 
age  rectifier  assemblies  in- 
clude: Edal  Industries,  4  Short 
Beach  Rd.,  E,  Haven  CT  06512; 
Electronic  Devices,  Inc.,  21  Gray 
Oaks  Ave.,  Yonkers  NY  10710; 
International  Rectifier,  233  Kan- 
sas St.,  El  Segundo  CA  90245; 
Unitrode  Corp,,  580  Pleasant  St,, 
Watertown  MA  02172;  Varo 
Semiconductor,  PO  Box  676, 
Garland  TX  75040;  and  Westing- 
house  Electric  Corp.,  Semicon- 
ductor Div*,  Youngwood  PA 
1 5697. 

4.  Courtesy  of  Semtech  Corpo- 
ration. 

5.  Courtesy  of  Semtech  Corpo- 
ration, 


96     73  Magazine  *  December,  1980 


■ 

■ 

■ 

^M  ■ 

■ 

■1 

1 

B 

1 

® 

ANTENNA  SySTEIVIS 
-800-654-52^1 


1 


HB43SP 


$219.95 


HB33SP 


$174-95 


TET,  THE  LEADER  [!H  WIDEBAND  ANTEMNA 
DESIGM,  introduces  another  new  triband  anten- 
na to  provide  unmatched  wideband  performance 
on  the  10,  15  and  20  meter  amateur  bands.  This 
radical  departure  from  conventional  triband 
antenna  design  employs  TWO  DRIVEM  ELE  - 
MEfHTS  with  a  rigid  phasing  line  to  couple  power 
from  the  radiator  element  to  the  reflector.  Phase 
relationships  have  been  carefully  engineered  to 
provide  extremely  high  gain  figures  without 
neglecting  the  need  for  high  front  to  back  ratio. 
The  two  element  drive  system  is  coupied  to  one 
parasitic  director  on  the  model  HB33SP:  two 
parasitic  directors  on  a  longer  boonii  with  the 
modeiHB43SP. 

FULL  BAND  COVERAGE  Is  possible  without 
the  need  for  antenna  tuners  or  separate  CW  and 
phone  antenna  adjustments.  The  1.5:1  VSWR 
bandwidth  covers  the  entire  20  and  13  meter 
amateur  bands,  with  a  little  extra  for  MARS 
operation.  On  10  meters^  coverage  is  in  excess 
of  1  MHz. 

QUALITY  COMSTROCTION  and  repeatable 
performance  permit  TET  to  deliver  an  antenna 
package  without  need  for  any  tuning  adjust- 
ments* All  tubing  is  cut  and  pre-drilled  to  preci- 
sion tolerances.  The  phasing  harness  and  feed 
assembly  for  the  two  driven  elements  are  pre- 
assembled  to  insure  ease  of  construction  and 
reliable  performance. 

MOVE  GP  with  the  performance  oriented  leader 
in  antenna  technology.  Order  your  new  high 
performance  wideband  triband  antenna  system 
from  TET  today. 


mODEL 

BAflDS 

MEMTS 

ELE- 
MENTS 
PER 

BAIMD 

MAX 

PWR 

VSWfi 

iMPEDArtrp 

MAX 

ELEMEMT 

LCTH 

BOOM 
LQTH 

TURfl- 

ING 
RADIUS 

WIHD 
SaRFACE 

AREA 

WIND 

LOAD 
®80  mph 

BOOM 

DIA- 
METER 

MAST 
SfZE 

WT 

HB43SP 
HB33SP 

14/21/28 
14/21/26 

4 
3 

4 
3 

2KW 
2KW 

BELOW  1.5 
BELOW  1.5 

50Ohfm 
50  Ohm 

27 
27- 

19' r 

I3'2" 

16' 9:' 

15' 

6.62  sqfL 
473  sq.ft. 

131,3  1b. 

102ib. 

2" 

19/16" 

38  1b. 
27  !b. 

Call  Factory  for  AMUfiriA  G AJfi  dBd  and  PROMT  TO  BACK  RATIO. 


TET  FACTORY  DIRECT  PRICE 


HB43SP     $219.95 
HB33SP     $174.95 


CaU  Toll  Free  1-800-654-5251 


ViSA 


TET  USA.,  INC. 


1^73 


master  charga 


425  HIGHLAND  PARKWAY,  NORMAN,  OKLAHOMA  73069 TEL:  405-360-6410 


*^  R&ader  Service—  see  0^g&  226 


73  Magazine  •   December,  1980     99 


Keith  Carter  WD4LWC 
Route  I  Box  12 J 
Sycamore  CA  31790 


Cheap  Connectors  for 
Half-Inch  Hardline 

at  your  neighborhood  hardware  store 


You've  just  become  the 
owner  of  some  really 
nice  half-inch,  72-Ohfn 
CATV  hardline,  but  where, 

oh  where,  will  you  find  con- 
nectors for  this  prize?  What 
will  you  do?  What  wiU  you 
do?  To  make  matters  worse, 
you  know  that  even  if  you 
had  the  money  to  purchase 
commercial  connectors, 
they  would  not  fit  anything 
in  your  shack.  And  what  if 
your  fellow  amateurs  found 
out  that  you  weren't  inno- 
vative enough  to  come  up 
with  something  as  simple  as 


a  cable  connector! 

Don't  despair;  you're  not 
alone.  I  found  the  answer 
after  several  weeks  of  think- 
ing, looking,  asking,  and  try- 
ing every  harebrained  idea 
that  came  along.  I  found  it 
across  town  in  the  plumb- 
ing section  of  the  local 
hardware  store,  for  less 
than  a  dollar. 

Another  Way 

WA4VYR,  a  good  friend 
and  the  inspiration  for  my 
original  idea,  has  success- 
fully   used    the    following 


method  of  solving  this  prob* 
lem  without  any  cash  out- 
lay. He  simply  strips  the 
half'inch  hardline  just  as 
you  would  strip  RG-8,  Using 
two  pairs  of  standard  pliers, 
he  screws  a  PL-259  connec- 
tor up  onto  the  aluminum 
jacket  and  solders  the  cen- 
ter in  the  normal  fashion.  I 
tried  this  method  — and 
tried,  and  tried,  and  tried, 
until  I  finally  decided  that 
there  had  to  be  an  easier 
way.  (The  one  1  did  get  to 
work  lasted  only  two  weeks 
before  Mother  Nature  pro- 


Photo  A.  The  completed  connector 


duced  a  break  where  the 
259  and  aluminum  jacket 
joined.) 

My  Way 

After  the  trip  up  the  tow- 
er to  find  the  broken  con- 
nection, I  dried  my  eyes  and 
resumed  my  quest  for  a  bet- 
ter way.  When  you  don't 
know  where  you're  going,  I 
had  been  told,  make  an  out- 
line. Just  what  did  I  need  to 
do  the  job?  1  wanted  a  cou- 
pling that  was  compatible 
with  the  existing  system. 
namely,  with  SO-239/PL-259 
hardware.  And  the  joint 
needed  reinforcing,  I  decid- 
ed, in  the  tight  of  my  previ- 
ous experience.  The  cou- 
pling must  be  small  and 
have  no  clamps  or  sharp 
edges.  It  also  would  be  nice 
if  it  could  be  weather- 
proofed  easily.  And,  above 
all,  it  must  be  simple  and 
cheap. 

As  1  mentioned,  the  solu- 
tion to  all  this  was  found  in 
the  local  hardware  store. 
This  particular  store  had  a 
display  of  brass  fittings 
used  for  the  installation  of 
copper  gas  and  water  lines. 
Among  them  was  a  half- 


100     73  Magazine  *  December,  1980 


FORAAULA  FOR  2  METER  FM  ENJOYMENT 


?•;■■■  !-S 


143-149  MHz 

25  uv  sensitivity 

mobile  mount  &  microphone  included 

25  Watts  (variable) 

Provisions  for  non-standard  splits 
(CAR  MARS,  etc.) 

Optional  AC  power  supply  available 


■.■f■■■■:H^.■+;^v  ■.-.'■••  -x^-x^'j.  If  -v  T^y*  :->  ka  ••.  -;.;■!■ -w-^.v-     ■K-;■^x■        '   v-.-Jw:-:-.-,'—  ;   '^M-i^x-  «■  h  -h-'h-.-- 


■:.:•:■'»■       y^i.-x-.v  '-^:■^^w■v•■•■>;•^  '    'M--:-ji: 


THAT'S  CORRECT!!! 

We  are  convinced  that  the  FA/\-88  is  four 
times  iliore  reliable  than  the  other  2  meter  rigs 
being  offered.  Tp  prove  it  to  you,  we  are  supply- 
ing the  FM-88  with  four  times  more  warranty 
than  supplied  with  other  models  — One  full  year 
instead  of  the  normally  expected  90  days. 

While  there  are  radios  on  the  market  that 
offer  lots  of  ''gadgets"  — our  past  experience 


has  been  that  simplicity  of  operation  &  elimina- 
tion of  unnecessary  ''Bells  &  Whistles"  actually 
removes  the  causes  of  many  failures  being  ex- 
perienced with  such  transceivers. 

If  you  are  shopping  for  a  new  2  meter  trans- 
ceiver, don't  you  owe  it  to  yourself  to  go  with  a 
radio  that  has  proven  itself  with  thousands  of 
hours  of  reliable,  "On  the  Air"  operation? 


Phort^  1  (800)  233-0250  today  to  order  your  FM-88  or  to  request  a  detailed  brochure  describing 
this  fantastic  transceiver  &  related  accessories. 

The  FM-88 15  also  available  with  an  800  channel,  programmable  scanner  — order  model  FM-88S  — $379*00 

Communications  Corp. 
1911  Old  Homestead  Lane 
Greenfield  industrial  Park  East 
Lancaster.  PA  17601 
(717)299-7221 


inch  brass  compression  cou- 
pling. 

This  connector  is  a  per- 
fect adapter,  (t  wrll  fit  a  I- 
most  perfectly  over  the  alu- 
minum jacket  of  the  com- 
nfionly-available.  half-inch 
CATV  hardline.  It  consists 
of  the  five  parts  shown  in 
Photo  B:  the  main  body, 
two  brass  collets  — one  in- 
serted into  each  end  of  the 
main  body,  and  two  brass 
caps.  These  collets  con- 
strict around  the  tubing  be- 
ing joined  when  tightened 
correctly  and  form  an  air- 
tight, firm  connection  To 
make  matters  even  simpler, 
the  main  body  has  a  rim 
centered  inside.  This  allows 
the  cable  to  be  inserted  and 
seated  properly  before 
tightening 

So  much  for  the  history 
and  sales  pitch.  Gel  your 
parts  up  and  follow  me 
through  the  simple  ten-min- 
ute assembly. 

Assembly 

Prepare  the  end  of  the 
hardline  as  shown  in  Photo 
C.  Cutting  is  done  best  with 
a  small  tubing  cutter  be- 
cause of  its  smooth  cutting 
action.  Loosely  assemble 
the  brass  fitting  and  twist 
one  end  onto  the  prepared 
end  of  the  CATV  cable.  This 
will  be  simple  to  do  correct- 
ly since  the  cable  will  stop 
when  it  contacts  the  inner 
rim  inside  the  brass  fitting. 
Smce  the   main   body  and 


end  caps  are  machined  for 
gripping  with  standard 
wrenches,  use  two  wrenches 
and  tighten  this  end  very 
snugly.  Be  careful  not  to 
strip  the  brass  threads,  but 
do  make  sure  you  tighten 
the  cap  enough  to  com- 
press the  collet  around  the 
hardline  jacket.  Don't 
worry  if  the  union  crooks 
slightly.  I  said  the  fit  was  a/- 
most  perfect! 

Next,  it  is  very  important 
to  scrape  all  the  enamel 
coating  from  the  center 
conductor .  1 1  won't  solder  if 
you  don't.  Now  we  are 
ready  to  slip  a  PL-259  onto 
the  center  by  screwing  it  on- 
to the  foam  insulation  and 
up  into  the  brass  fitting.  It 
probably  won't  go  far 
enough  to  seat  against  the 
inner  rim,  but  it  will  be  far 
enough  to  allow  the  collet 
to  tighten  properly.  Don't 
overdo  the  insertion  bit 
here;  remember,  you'll 
need  to  be  able  to  turn  the 
cap  of  the  PL-259!  The  rest 
should  go  without  further 
detailed  description. 

Solder  the  center  in  the 
normal  fashion  and  trim 
any  excess  length  from  it  af- 
terwards. Don't  tin  the  inner 
conductor  before  insertion 
because  you  will  find  they 
fit  very  closely,  and  it  prob- 
ably wouldn't  fit  afterwards 
if  you  do,  Prestol  You  now 
are  back  on  familiar 
ground.  The  259  connector 
should  be  readily  adaptable 
to   most   of  your   amateur 


needs. 

When  I  showed  my  dis- 
covery to  KA4DPF,  a  close 
friend  who  is  an  engineer 
for  the  local  power  com- 
pany, he  remarked  that  this 
connector  had  a  very  im- 
portant virtue  that  I  had 
overlooked.  Since  direct 
connection  of  dissimilar 
metals  always  produces 
some  corrosion,  the  power 
company  uses  brass  inter- 
mediate connectors  to  pre- 
vent eventual  problems. 
Hence,  this  configuration 
should  provide  years  of 
trouble-free  operation, 
especially  if  taped  well 
when  installed. 

Installation 

By  now  you  should  have 
surmised  that  I  am  relative- 
ly non-technicat  and  am  far 
from  being  an  expert  on  an- 
tenna technology  How- 
ever, some  remarks  about 
matching  72-Ohm  cable 
with  a  50-Ohm  system  are 
in  order.  I  am  told  by  those 
more  knowledgeable  than  I 
am  that  the  following  con- 
ditions are  found  in  this  sit- 
uation. Provided  the  anten- 
na is  an  acceptable  match 
to  the  transmitter  and  the 
72-Ohm  cable  is  exactty  a 
multiple  of  one-half  wave- 
lengths long  at  the  operat- 
ing frequency,  the  transmit- 
ter will  effectively  "see" 
the  antenna  load  at  the  oth- 
er end  regardless  of  the 
characteristic  impedance 
of  the  line  Further,  the  ex- 


pected loss  from  this  line 
mismatch  would  be  only 
around  1 .6  to  1 :  probably  a 
good  tradeoff  relative  to  a 
long  run  of  RC-8,  especially 
from  a  receive-loss  stand- 
point 

I  matched  the  system  at 
K4QT/RPT  and  at  my  home 
station  by  inserting  differ- 
ent lengths  of  RC-S/X  be- 
tween  the  hardline  and  the 
transmitter  until  I  found 
one  that  made  the  total  ca- 
ble length  appear  to  be  the 
proper  length.  The  reflect- 
ed power  shown  on  a  50- 
Ohm  Bird  43  was  less  than 
one  Watt  with  twelve  Watts 
out  of  the  transmitter.  The 
flexible  jumpers  are  a  wel- 
come addition  also  when 
moving  and  installing 
equipment. 

I  am  certain  that  this 
method  has  its  faults  and  I 
would  welcome  any  con- 
structive advice  concerning 
better  methods  The  repeat- 
er, which  was  constructed 
from  an  old  Heathkit® 
HW-202,  has  been  operat- 
ing on  this  system  for  about 
a  year  now  without  inci- 
dent. This  doesn't  prove 
anything  except  that  a 
solid-state  transmitter  can 
operate  well  when  used  in 
the  manner  described. 

Perhaps  these  ideas  will 
be  of  some  help  to  you 
when  you  come  across  that 
old  CATV  cable  someone 
else  doesn't  want  or 
couldn't  figure  out  how  to 
use!H 


Photo  B.  The  five-part  brass  adapter. 


Photo  C  Half-inch  CA  TV  hardline,  adapter,  and  PL-259. 


102     73  Magazine  •  December,  1980 


ATR-6800 


gets  *10  dB'  boost 


The  proven  RFI  proof  system  for  RTTY/CW  is  now  available  with  applica- 
tions program  modules.  Multiply  your  computer  power  to  make  amateur 
radio  a  real  blast*  Our  first  plug -in  module  adds  10  ham  oriented  programs 
such  as:  SSTV  Transmit ,  Auto-CQ /Response,  Mailbox,  Log  Keeper,  and 
RTTY  Speed-Seeker  with  more  modules,  including  BASIC  to  foUow  soon. 
All  utility  programs  permanently 

stored  in  ROM  ready  to  execute  from     ^^^flpP^      ll 

the  keyboard.  Application  module 
number  one:  $189-  Interface  con- 
nector mounts  on  rear  of  the  ATR- 
6800  free  with  first  module.  ATR- 
6800  with  9"  monitor;  $1995,  with 
companion  printer;  $2445 •  There's 
ne\' er  a  dull  moment  here  at  Miaolog 
Corp.,  4  Professional  Drive,  Suite 
119.  Gaithersburg,  MD  20760, 
Telephone:  (301)948-5307. 


^51 


MICROLOG 

Innovators  in  Digical  Commumcations 


*^  Res^^f  Service — see  o&ge  226 


73  Magazine  •  December,  1980     103 


UNIVERSAL  CONVERTER 

ASCII  -  BAUDOT  -  MORSE 

ABM-200 


nliitt^M 


+Sv 


ASCII 


f       MORSE 


BAUDOT 


The  A0M-2OO  IS  a  universal  code  converter 
for  translating  oefween  ASCII  and  Baudot, 
or  beiwe^n  Morse  and  ASCII  (or  Baudot) 
Also  use<3  as  TTY»  speed  and  ime  length 
convefter  Inserts  directly  between  TU  and 
TTY^  RS232  &  current  plus 40  ctiar  FIFO 
buffer  Write  for  details  $169. 


0€M  inquirivM  trmHmd. 


COD, 


XlTEX  Corporation 

&S61  Chartwell  Dr, 

Dallas.  Texas  75243 

214-349-2490 


CfMCh 


/\fOlSE  AND  FLASHES 
CAN'T  STOP  THEFT!!! 


BUI  AiitoRigC  C  fKt4 

us  IT  PACFS  YOU 

129^' 

POST  PAID 

roi  CALL  POLICE 
CAR -HOME -OFFICE 

CHECK  OR  MONEY  ORDER 

CAL.  RES   ADD  6  PERCENT  TAX 

ADD  2.50  FOR  C.0-0. 

ELECTRONICS 

10672  WOODBURY  ROAD 
GARDEN  GROVE,  CA    92643 


Scanners 


BEARCAT 


REGENCY 

f?804  S  8 

R106  to 

M10O  20 

M400  27 

NJL  HESIDtNTS 
ADD  5%  SfilES  TAX 


HO  COO*s.  CHECKS.  MONEY  ORDERS  VtSA  OH 
ti^ASTERCHARGE  AR£  ACCEPTABLE  ADOS3  50 
EACH  ITEM  FOR  SHfPf^tNG  AND  HANDLING 


PAUL  DAVIS  ELECTRONICS 
PEDDLERS  VILLAGE 

MANASQUAN,  NJ  08736 


TEL  20t  223-923B  WEEKENDS 
201-^93^511  EVE'S 


V  -A*-*  CO-AXIAL 

^  ANTENNA 

UGHT    STRONG    EFFICIENT 


;I 


SPECIAL  SALE 

Model  CO-2A 
2  Meters 

$19.95  Delivered 


Herb  Kreckman  Co, 
Cresco,  PA.     18326 


i^3TS 


MILITARY  SURPLUS 
'  V,     WANTED     ^  ' 

Highest  prices  ever  on  recent  U.S.  ' 
Military  surplus.  especiaUy  on 
Collins  equipment  or  parts.  We 
Pay  freight.  Call  collect  for  high  of- 
fer. (201)  440^8787.  35  Ruta  Court. 
S.  Hackensack.  N.J  07606 

— y      1^317  \. 

SPACE  ELECTRONICS  CO. 


Men 


^k 


HAMS... with TRS-80'  Computers 
GET  ON  RADIOTELETYPE 


with  BIT-BYTER 


Complete  svslem  mdydes  BH-BYTER  tnlerface  AND 
the  FfrV-BO  computer  program 

Great  Features:  split  screen,  level  1  and  2  4K 
computers,  transmit  buffer  and  countless  others 
all  at  this  terrific  phce: 

Only  $129.00 

Order  today  ,    ,  or  for  more  informalion  write  to: 

Vic  Frump,  KSEXJ 

UHF  SALES  a  SERVICE  COMPANY 

Rt,  1.Bo)(52A 

Evans  Wesi  Virginia  25241         ^^361 


(304)  372-2047 
lARKd 


TRADEMARK  of  TNe  Tandy  Carporation 


Now  wilh  Ciiui'lesy 
beep  ana  tn^acon 


144 


ilEPEIITERi  230 


New  and  Impfoved 

Receiver 

and  Transmiller 


(Included  m  All  Repeaters) 


COR  Identifier:  All  on  one  band, 
pnigrammable.  Fully  adjustable, 
HiiuMnitf.SJ'T  mln.).  Kan^  time  (0-1 
111  in.  J,  idfritifk'T  (1-10  niin.K  tone, 
^JXt'd.  volurne.  L,E.D.  outputs. 
low  ctirrt'nl  drain.  CMOS  logic, 
phip^  f(ir  cssy  l[l^tallatLar>  ar)d  fg- 
tno%'al  plus  much  more  $99.95. 

Bask:  Repeater  S649.95 

2M  130-175  MM  Basic  Ri?iM*attT  for  2  im-ti.'n.  with  all  the 
fealtircs  of  the-  Hi  I'ru  Mki  less  the  power  aipph  and  front 
pane)  eontrob  and  accessoni^. 


Maggiore  Elcclronic  Laboratory 

845  Westtown  Rd 

West  Chestei,  PA  19380    Phone  (215)  436-6051 


*^46 


450  MHz  also  available, 

OPTtONS 

Duplexers 

Basic  auto  patch       t 

Matching  cabmet 

0005%  High  slabihty 
crystals 

Hi  Pro  Mk 


144  or  220  MHz  $849.95 


PLUSSHIPPtNG 
PA  Res,  add  6%  tax 


104     73  Magazine  *  December.  1960 


*    m 


at  last . . . 
your  shack  organized! 

A  beautifuf  piece  of  furniture  —  your  XYL  will  love  it! 

$16450  S-F  RADIO  DESK 


^ 


Deluxe  -  Ready  to  Assembte 


Also  Available 

FloQT  Space:  5V  Wide  by  30"  Deep 

$192.50 


Designed  with  angled  rear  she!f  for  your 
viewirtg  connfort  and  ease  of  operation 

FINISHES:  Walnut  or  Teak  Stain. 

Floor  Space:  39"  Wide  by  30'*  Deep 

Adfjjlional  Intormation  on  Request, 

Checks,  ^Soney  Orders,  BankAmericard 

and  Master  Charge  Accepted. 

F.O.8.  Culver  City,  [In  Ca«if,  Add  6%  Sales  Tax.) 
DEALER  INQUIRIES  INVITED 


$1 


*^65 


S^r  flmfhteur  Radio /i&fVKe/ 

KEYSTONE  AVENUE  •  CULVER  CITY,  CALIF,  90230  —  PHONE  (213)  837-4870 


% 


The  BEST  in  Code  Converters 

THE  INFO-TECH  M200-F  TRI-MODE 

CONVERTER     ^  J 


nSffg^TICHi    »40«P 


Kia     —     ill 


on  '^     id 

Q     ©1 


uinrtp        *Tc 


'vSP^- 


MmwL 


TUMCTKWHS-'™  BfiL 


t»t^-^. 


mmtnr 


J^ 


Converts  Morse 

&  RTTY 
[Baudot  &  ASCII) 
to  video,  ancf  serial 

Baudot  or  ASCII  for  hard  copy 

Morse  Reception:  6-55  wpm  standard  (simple  user  adjustment  for  higher 
speeds).  Automatic  speed  tracking  &  word  space  adjustment. 

RTTY/ASCII  Operation:  Decodes  RTTY  (45,  50,  57,  74,  100  Baud)  and 
ASCII  [110  &  300  Baud),  Auto  CR/LR  automatic  threshold  control  select- 
able unshift  on  space,  limiter  is  switch  selectable,  solid  state  tuning 
"meter'\  Demodulator  has  3  fixed  shifts  and  1  tunable  shift,  user  select- 
able printer  outputs  in  ASCII  or  Baudot  for  all  modes  with  cr/stal  con- 
trolled baud  rate  generator  RS232,  TTL  &  isolated  loop  outputs.  User 
adjustable  autostart 


Video  Display  Formats 

(User  Sefectable) 
16  lines  x  32  characters,  16  lines  x  72  characters, 
25  lines  X  32  characters,  25  lines  x  72  characters 
50  or  60  Hz  operation.  Cursor,  on  or  off 

Built-in  t15/230v  power  supply 


Price 


$575.00 


FOB  factory 


We  accept 


trtrnKf^r^-^ 


VISA 


or  See  These  Dealers 

A- 1  Tecbnik 

Btorrtberg  3 

D-S882  Meinerzhagen  2 

Wesl  Gerrrkariy 

Cohoon  Amateuf  Supply 

307  McLeari  Avenue 
HcpHlnsvflle,  Keii!ucJ<y  422^0 
(502)  386-4534 

Col  may  Pr<}diicts 

1:4903  Beachview  Ave 

Wtiite  Rock,  B,C  Canada  V4B1N8 

Dialta  Amateur  Radio  Supply 

212  4Slh  STfeet 

Bapict  City.  South  Dakota  bT'm 

Germaniown  Amateur  Supply 

3202  SummeJ'  Avenue 
Memphis,  Terifi^^ss^e  391 1^ 
l-BW'S38^ie8 


1633  Wisteria  Court 


Gitler  Associates,  inc. 

&2  Park  Avonuc 

Park  Rid^e.  New  Jersey  07656 

(201)591-7887 

Global  Communicalions 

606  Cocoa  isles  Blvd 
Cocoa  Beach  Florida  32931 
(305 »  783-36^^ 

Ham  Radio  Canter 

83^52  Ofive  BSvd 

St  Loui^,  MissouM  63132 

1  -800-325^3636 

Marcucci  SPA 

Via  F  LLl  Bronz^lli 
37  2G129 
Milan   llaly 


INFOTECH 


Mastercharge,  Visa 


N  &  G  Dtslributifig 

7285  NW  I2lh  Sireel 
Wianm.  Flon<ja  33126 
^3051  592^9685.  763-6170 

Radio  World 

TeRTiinal  Building 
Oneida  Couniy  Airpon 
Oriskany,  New  York  1  342^ 
(315)337^2622. 

Ray's  Amateur  Radio 

1590  US  Hjghway  (9Sou[3i 
Clearwater.  FlorJda  33516 
{813)635-1416 

Universal  Amateur  Radio 

1280  Aida  Drivi? 
Reynoldsbucg,  Ohio  430S8 
(614)  666-426? 


ELECTRONIC 
EOUIPMEMT 


v^as 


Matmfactured  by: 

DIGITAL  ELECTRONIC  SYSTEMS,  INC. 

Englewood.  Floncla  33533  •  813''474-9518 


For  the  best  deal  on 

*  AEA*  Af  I*  a  n  c  e*  A  m  e  c  o»A  p  pi  e*  ASP 
•Av3n(i*flelden«Bencher»Bird*CDE 
*CES»CamniunJcalJ(>ns  Specialists 
•CDl1ins*Cushcrafl«Qaiwa*DenTrQn 
•Drake*  Hustler*  Hy-Gain*lcam<IRL«KLM 
•Kenwood*  L3rsen*MacrotroniGs*MFJ 
•Witfland* Mini  Products* Mirage* Mosley 

*  N  PC*  Newtronics*  Hye*  Panason  Ic 
*PalDmar  £ngineers*Regency*Rotiat 
*Shijrc*Star?[farrf*Swsn*TEmpD 
*Ten  Tec*TranscDm*Yaesu 

HOLIDAY 
SPECIALS 

KENWOOD  TR-7600 
closeout  $269 

ICOM  IC-255A  $329 

TEMPO  S-1  .........  $239 

with  touchtone    ..  $269 

KENWOOD  TR-7800, 
TR-9000  and  TR-2400 
all  now  in  stock...  Call 
for    great    Erickson 
prices  today! 

APPLE:  Buy  a  1 6k  Apple  II 
or  Apple  II  Plus  for 
$1195;  get  32k  more 
memory,  installed,  free! 

Complete  with  disc  drive, 
only $1739 

App(e  prices  include  prepaid  shipping 
within  continental  U  S.A. 

CALL  TOLL  FREE 

(outside  IIIFnofs  only) 

(800)  621-5802 

HOURS:  9:30-5:30  Mon.,  Tues.,  Wed.  &  Fri. 
^■■I       9:30-9:00  Thursday 
9:00-3:00  Saturday 


ERICKSON 

COMMUNICATIONS 

Chicago,  IL  60630 

5456  North  Milwaukee  Ave. 

(312|631-518l|within1Nmois| 


i^  Reat^er  Service— see  psge  226 


73  Magazine  ■  December,  1980     105 


Eugene  f .  Rupsrto  W3KH 

RD  t  Box  i66 

West  Alexander  FA  15376 


The  Microwave  Midget 

this  WEFAX  converter  features  something 

different  — an  active  mixer 


Several  years  have 
parsed  since  NO  A  A  (Na- 
tional Oceanic  and  Atmo- 
spheric Ad  ministration  J 
graduated  from  VHF 
WEFAX  (Weather  Facsim- 
ile) satellites  to  geosyn- 
chronous microwave  satel- 
lites. True,  some  of  the 
jgoiar-orbiting  satellites 
transmitted  data  on  S-band, 
besides  the  low-frequency 
product  usually  found  on 
1373  and  137.62  MHz,  but 
only  the  bravest  of  souls  at- 


tempted to  track  such  a 
fast-moving  target  with  a 
narrow  beamwidth  dish.  Be- 
sides, I  was  content  to  ex- 
tract weather  pictures  from 
the  low-altitude  polar  or- 
biters  and  occasionally,  for 
some  real  DX,  from  ATS-1 
or  ATS-3  parked  some 
22,50D  miles  above  the 
equator. 

In  April,  197%  NOAA 
published  Technical  Mem- 
orandum NESS  54,  by  John 
Nagle,  entitled  "A  Method 


of  Converting  the  SMS/ 
GOES  WEFAX  Frequency 
(1691  MHz]  to  the  Existing 
APT/WEFAX  Frequency 
(137  MHz)/'  This  was 
followed  up  with  an  APT  In- 
formatJon  Note  (7 6- W 4]  in 
September:  1976,  advising 
alt  ground  stations  of  the 
proposed  S-band  broad- 
casts and  schedules.  Clear- 
ly, the  handwriting  was  on 
the  wall,  and  many  of  us 
(some  reluctantly)  were 
dragged  into  the  realm  of 
microwaves. 

The  rush  to  1691  MHz 
was  not  especially  spec- 
tacular, and  for  most  of  us, 
it  resembled  a  stow  and 
laborious  climb.  Micro- 
corn  m  rose  to  the  occasion 
with  a  line  of  inexpensive 
modules,  and  a  fine  article 
by  WB8DQr  showed  us 
how  to  use  them,  besides 
providing  a  wealth  of  data 


D 


32    COAX 


RF  AMP 

l£dQ 


1 6'  cush 


on  dishes,  gain  figures,  path 
Igs^  and  margins. 

The  annual  gathering  of 
weather-satellite  buffs  at 
the  Dayton  Hamvention  in 
1979  unearthed  several 
home-brew  devices,  but  I 
believe  none  has  been  de- 
scribed in  print  with  the  ex- 
ception  of  one  produced 
by  C8FCD.  He  wrote  about 
his  METEOSAT  (Europe's 
counterpart  to  GOES)  Earth 
station  in  recent  issues  of 
Wireless  Worid,^ 

The  heart  of  my  system  is 
an  active  mixer  — a  mixer 
with  conversion  gain  rather 
than  the  conversion  toss 
associated  with  diode  mix- 
ers. The  expected  ground- 
level  signal  of  —  134dBm  is 
not  exactly  an  S-meter  nee- 
dle bender,  so  every  bit  of 
help  you  can  get  in  the  way 
of  gain  in  the  system  is  to 


ACTfVe 
MIXER 


13-7  SMHj 
I-F 


LOCAL 
OSCILLATOR 
517. B33 
5mW 


Photo  A.  The  six-foot  dish  and  feed  horn. 


Fig.    1.  System  configuration   for  the  act/ve-m/xer  con- 
verier. 


106     73  Magazine  *  December,  1980 


Photo  B.  No  land  mass  is  visible  in  this  photo  of  the  NE 
quadrant  Placed  above  and  overlapping  Photo  C  cover- 
ing the  SE  quadrant,  complete  coverage  of  the  eastern 
half  of  the  hemisphere  is  obtained. 


Photo  C  South  America's  v^est  and  east  coasts  are  visible 
in  this  picture,  at  lower  left. 


your  advantage  (and  of 
benefit  to  your  wallet)  be- 
cause high-gain  preamp^ 
and  transistors  at  this  fre- 
quency still  cost  a  few 
bucks.  I  was  convinced  of 
the  worth  of  an  active  mixer 
by  W6KT  through  corre- 
spondence and  because  of 
his  success  with  such  a 
device  — although  his  dif- 
fers considerably  from  the 
one  about  to  be  described.  I 
used  an  almost  exact  Copy 
of  an  active  mixer  de- 
scribed by  Lark  in  Crutcher 
WA5WOW3  for  1296  MHz, 
with  a  few  modifications 
necessary  to  achieve  simi- 
lar results. 

Circyit  Description  and 
Layout 

The  active  mixer  consists 
of  two  half-wavelength 
lines  of  #10  soft-drawn  cop- 
per wire  grounded  at  both 
ends  of  their  respective 
cavities  and  tuned  at  their 
center  point  with  10-32 
brass  screws.  The  brass  nuts 
are  soldered  inside  the 
cavities.  At  one  end  of  the 
multiplier  cavity,  a  signal 
from  the  local  oscillator  is 
injected  at  517.833  MHz  at 
5  mW,  which,  in  turn,  is 
multiplied   by  3  to  1553.5 


MHz.  The  output  signal 
from  this  cavity  is  coupled 
to  an  inductive  link  at  the 
other  end  of  this  line.  The 
input  signal  at  1691  MHz  is 
coupled  to  the  input  cavity 
via  a  capacitive  probe  at 
one  end  of  the  line  and 
taken  off  the  other  end  of 
the  line  with  a  capacitive 
probe. 

This  probe  and  the  induc- 


tive link  of  the  multiplier 
cavity  are  composed  of  one 
piece  of  #14  wire  bent  into 
a  U  shape,  20  mm  long  with 
12-mm  legs.  The  difference 
signal,  137.5  MHz,  is  cou- 
pled to  the  mixer  transistor 
by  connecting  a  100-pF  disc 
ceramic  capacitor  from  the 
center  point  (10  mm]  of  the 
U-shaped  link  to  the  base  of 
the  MRF901.  The  collector 
of  this  transistor  uses  a 
conventionally-tuned    out- 


put circuit  to  the  137.5- 
MHz  wideband  FM  receiv- 
er. No  preamp  was  neces- 
sary. 

The  active  mixer  box  is 
constructed  entirely  of 
double-sided  PC  board.  The 
base  is  slightly  longer  than 
88  mmX54  mm,  and  the 
four  walis  plus  the  center 
partition  are  made  from 
1-inch-high  strips.  The  ac- 
tual box  dimensions  are  88 
mm  X  50  mm  X  25  mm   The 


517.  aa  3  MHz 

to     IWPUT 


^MA   0^  3NC 


F.T 


,rO^^-^, 


( 


SOmm 


HI2lH 


^^^ 


LI 


CI 


"^^r 


B 


L5 


/oN.  L^ 


C2 


'^^r 


T 


L4 


) 


>r- 


4T 
- — -^wv- 


) 


\  TO    BASE 
WRF90I 


SMA  OR  SNC 


OS  rnm 


1691  MHI 

INPUT 


/^ 


,  2  5^ 
NOIi^lNAL 


if 

5-20pF 


It 


ZT 


[]FB 


PC. 


ICJK 


*r^ 


E 


[]Fe 


RC. 


BNC 


■rr 


3     I-F  OUT  137.5 


+  12V  DC 


aiAS 


?5mm 


<&QmfT\ 


CENTER   PARTITION 


T 


hSmm 


1 


iSmen— ^ 


CUT  our  FOR    "U"    LINK 


Fig.  2.  Schematic  of  the  active  mixer.  Lh  L2  —  ^10  wire;  CI,  C2  — 10-32  nuts  and  bolts; 
L3  —  20  mm  X  74  mm  U-shaped  linK  it  1 4  wire;  D1  —  MA4882  mixer  diode;  L4  —  12  mm  X 
7  mm  X  2  mm  tab. 

73  Magazine  •  December,  1980     107 


Photo  D.  NO  A  A  product  from  low-altitude  satellite  Tiros 
N  relayed  from  the  ground  through  uplmL 


center  partition  is  slightly 
shorter  than  88  mm  to  fit  in 
the  center  of  the  box,  and  is 
notched  at  one  end  with  a 

13  mmX15  mm  cut  out 
to   accommodate   the    U- 

shaped  link  A  hole  is 
drilled  in  the  end  wall  adja- 
cent to  the  link  for  mount- 
ing the  MRF901. 

A  very  small  hole  is 
drilled  into  the  baseplate 
near  the  wall  for  a  piece  of 


insulated  wire  to  pass 
through  and  connect  to  the 
base  of  the  transistor  to  pro- 
vide the  necessary  bias.  The 
rest  of  the  transistor  lives 
outside  of  the  cavity.  The 
low-frequency  circuit  for 
137.5  MHz  was  built  on  a 
small  piece  of  PC  board  and 
tack  soldered  to  the  back 
side  of  the  baseplate  for 
isolation.  An  additional 
one-inch  strip  was  soldered 


s-  > 


.     4 


C  t^ 


Photo  £,  Daytime  infrared  photo,  NW  quadrarit 


Photo  f  Back  side  of  the  active  mixer. 


to  the  baseplate  parallel  to 
the  long  walls  and  drilled 
for  mounting  on  a  19-inch 
aluminum  panel.  SMA  con- 
nectors were  used  for  the 
input  and  output  ports  to 
match  the  Microcomm  rf 
preamp  and  local  oscjlla- 
tor,  but  BNC  connectors 
should  work  as  welL 

Tune-Up  and  Operation 

I  wish  1  could  say  that 
everything  went  as  smooth 
as  silk  with  this  project  but 
I  traipsed  with  Murphy 
down  the  garden  path  for 
several  months  until  I  final- 
ly discovered  that  I  had  the 
collector  circuit  tuned  to 
about  300  MHz  The  micro- 
wave portion  of  the  mixer 
apparently  worked  well 
from  the  start.  I  used  a 
Hewlett-Packard  HP-614A 
signal  generator  for  a 
beacon/signal  source  for 
testing.  Initially,  I  biased 
the  MRF901  for  a  collector 
current  of  about  800 
microamps  without  oscilla- 
tor injection,  fired  up  the 
oscillator  and  tuned  the 
multiplier  cavity  for  max- 
imum collector  current 
which,  at  this  point,  was  1.2 
mA  By  bending  the  U- 
shaped  link  closer  to  the 
multiplier  fine,  squeezing 
the  multiplier  diode  closer 
to    the    line,    and    slightly 


deforming  the  line  itself 
downward  by  about  2  mm,  I 
picked  up  an  additional  600 
microamps  of  col  lector  cur- 
rent. 

Initially,  1  constructed  the 
mixer  with  inductive  links 
throughout,  but  in  actual 
practice  ended  up  with 
more  gain  by  cutting  the  in- 
put link  to  the  signal  line 
from  ground  and  also  the 
signal  line  portion  of  the 
U-shaped  link.  I  accom- 
plished this  tweaking  by  set- 
ting the  signal  generator  to 
1691  MHz  and  the  power  to 
0  dBm  and  turning  down 
the  calibrated  attenuator. 
The  tuning  screw  in  the 
signal  cavity  tunes  with  the 
10-32  screw  almost  all  the 
way  out  with  about  one 
thread  left  in  the  cavity. 
The  multiplier  screw  need- 
ed a  12-mm  disk  of  thin 
brass  or  copper  soldered  to 
the  end  of  its  10-32  screw  to 
tune  the  line  since  it  is  too 
short,  but  the  disk,  with  its 
added  capacity,  nicety 
pulls  it  down  lower  in  fre- 
quency. 

With  one  12-dB  gain  Mi- 
crocomm preamp  con* 
nected  ahead  of  the  mixer 
and  a  properly  functioning 
output  circuit  attached  to 
the  MRF901,  the  attenuator 
was  cranked  into  more  than 
--125  dBm  with  plenty  of 


lOfl     73  Magazine  •  Decembef,  1980 


signal  showing  on  the  re- 
ceiver,  so  I  moved  every- 
thing outdoors,  t  attached 
the  system  to  a  fe-foot  dish 
and  a  homennade  feedhorn 
sporting  an  N  connector 
through  ten  feel  of  RG*9 
cable  and  picked  up  a  fult- 
quieting  signal  from  SMS- 
COES  East  After  optimiz- 
ing the  feedhorn  for  focus 
and  polarization  angle^  I 
removed  the  preamp,  and 
though  the  signal  was  a  bit 
noisy  through  ten  feet  of 
cable,  I  think  it  would  have 
made  a  useful  picture. 

Since  most  of  the  users 
have  devised  ways  of 
mounting  their  converters 
and  preamps  at  the  antenna 
site,  I  assumed  that  it  woufd 
be  impossible  to  use  only 
one  preamp  and  expect  to 
use  the  system  indoors 
through  a  long  run  of  cable. 
Taggart  devised  such  a 
scheme  using  a  Cofeman  in- 
sulated cooler  and  an  in- 
cubator device.  My  dish  is 
situated  more  than  25  feet 
from  my  shack  and  'looks" 
through  an  ancient  sugar 
maple  tree  about  70  feet 
high  with  about  30  feet  of 
leaves  and  branches  in  the 
way.  I'm  sure  there  is  some 
signal  absorption  when  the 
sap  flows. 

To  satisfy  my  curiosity,  I 
attached  another  22-foot 
piece  of  RC'9  to  the  existing 
ten-foot  piece  and  still 
received  a  full-quieting 
signal!  I  now  have  the  en- 
tire system  indoors  except 
for  the  dish,  feedhorn,  and 
thirty-two  feet  of  RG-9 
cable  and  one  foot  of  RC- 
142/U  with  a  total  of  six 
connectors  in  the  line:  one 
SMA  male,  four  series-N 
males,  and  a  double-female 
N  "barrel'  connector.  (I 
believe  I  have  some  loss 
there.)  The  pictures  shown 
were  made  with  this  cable 
configuration,  but  someday 
1  hope  to  replace  it  all  with 
one  piece. 

Conclusion 

For  my  money,  the  active 
mixer  is  definitely  the  way 
to  go  at  these  frequencies.  I 


didn't  use  any  bandpass  fil- 
ters in  the  front  end  be- 
cause I  live  in  a  natural  dish 
in  a  rural  area.  For  a  more 
hostile  rf  environment  their 
use  probably  will  be 
necessary.  The  Microcomm 
LO  is  exceptionally  clean, 
so  I  got  away  without  one 
between  it  and  the 
multiplier  diode.  If  for 
some  reason  this  local- 
oscillator  module  is  not 
available  in  the  future,  you 
should  be  able  to  construct 
one  from  N6TX's  article-*  or 
build  your  own.  W6KT  built 
a  simple  oscillator  chain  for 
259  MHz  and  multiplied  by 
six  by  replacing  the  multi- 
plier diode  with  an  MRF901 . 

I  monitor  the  multiplier- 
diode  current  of  the 
.MA4882  with  a  O-IS-mA 
meter  Nominal  current  is 
between  4  to  7  mA.  The  col- 
lector  current  of  the 
MRF901  also  is  monitored 
with  a  0-TO-mA  meter.  By 
varying  the  bias  pot,  a  satis- 
factory operating  point 
would  be  from  900  micro- 
amps  to  about  2  mA,  with 
some  mixer  noise  becoming 
evident  above  this  figure. 
The  current  was  brought  up 
to  7  mA  without  a  tendency 
to  oscillate,  but  the  noise 
was  objectionable  and  the 
gain  started  downhill. 

Finally,  NOAA,  unlike 
the  private  sector  of  the 
satellite  business,  wel- 
comes the  use  of  their  ser- 
vice by  amateurs.  Bob 
Popham,^  the  coordinator 
for  the  NOAA  satellite  ser- 
vice, has  attended  the 
weather  satellite  sym- 
posiums at  Dayton  for  the 
last  several  years  as  one  of 
the  principal  speakers. 

The  weather  pictures  for 
this  article  were  produced 
on  a  facsimile  device  de- 
scribed in  my  previous  arti- 
cles. ^'^ 

1  think  I'll  get  out  my  PC 
board  and  try  for  some  con- 
verters for  1 296  and  2304  ■ 

References 

1.  Ralph  Taggan  WBSDQT.  '^Be 
a  Weather  Genius — Eavesdrop 
on  GOES/*  73  Magazine, 
November  1978. 


New  Improved  Adhesive 
Mount  for  the  2  Meter 
Avanti  Mobile  Antenna. 

Mounts  on  glass  — 
no  holes! 


=^ 


and  transmits 
through  gtass. 

Superior  performance 
eqyivalefit  to  S/8  ^wave. 

Superior  radiation  futi 
Omni- Directional. 


ANGLE 
ADJUSTMENT 


CAPACITY 

COUPLING 

BOX 


It's  easy  to  install  —  No  holes  to  drill,  no 

magnet  to  scratch  the  paint,  no  clamps. 

Uses  an  especially  developed  silicone 

adhesive  that  secures  antCfnna  to  window. 

The  capacity  coupling  box  is  simply  attached 

with  a  speciai  adhesive  tape  to  inside  of 

window.  Worried  about  crimping  or 

corroding  coaxial  cables?  It's  all  inside  and 

out  of  sight. 

ModaJft  also  available 

for  220  MH£  and  450  MHz, 

bsie  sffteifftas    Wnte  t&f  new  cttAtog  rotfay. 
Scfrd  50C  fof  handftffQ  and  postmje 


AN5\i\t\'  antennas 


^m 


Avanti  Research  and  Development,  Inc. 

340  Stewan  Ave..  Addison,  I L  60101  (312)  628  9350 

In  Canada:  Lenbrook  Ind.,  Scarborough,  Ontario  MIH  IH5 


:^ 


2.  Mike  Chrlstieson  G8FCD,  ^'A 
METEOSAT  Earth  Station," 
Wifeless  World,  June  and  July, 
1979. 

3.  Larkin  Crutcher  WA6W0W, 
"An  Active  Mixer  for  1298;'  QST\ 
August,  1974, 

4.  Paul  Schuch  N6TX,  "A  UHF 
Oscillator  for  the  Purist/'  Ham 
Radio,  July,  1979. 

5.  U.S.    Department    of   Com- 


merce, NOAA.  NESS.  Washing- 
ton DC  20233,  Attn:  Popham 
OA/S131. 

6.  Eugene  Ruperto  W3KH, 
^'Weather  Satellite  Pik  Printers," 
73  Magazine,  January,  1978. 

7.  Eugene  Ruperto  W3KH,  "A 
Satellite  Receiver  for  the 
Home/"  Scientific  Anrerfcan, 
"The  Amateur  Scientist/' 
January,  1974. 


Photo  C.  From  left  to  right:  the  oscillator,  active  mixer, 
and  preamp. 


■73  Magazine  •  December,  1980     109 


hnoldA.  Swank  W8HXR 
657  Wilfabar  Drive 
Washington  Court  House 
OH  43160 


The  Amazing  Bobtail 
. .  .Our  Readers  Respond 

more  ideas  for  using  and  modifying  this 

easy-to-build  antenna 


The  first  week  after  the 
Bobtail  article  was  pub- 
lished (May,  1980,  73  Maga- 
zine^ page  44),  four  hams 
wrote  me  that  they  had 
built  the  antenna  and 
agreed  with  my  evaluation, 

The  first  was  Jim  Gray 
W1XU,  who  tried  the  idea 
which  I  had  failed  to  try 
completely —  feeding  it 
with  coax  at  a  high-current 
point.  He  said  it  worked 
perfectly. 

He  used  984/f,  the  normal 
quad  formula,  and  had 
34.44  feet  for  the  separa- 
tion of  the  top  sections  be- 
tween verticals  and  17.22 
for  the  verticals.  It  was  1:1 
at  14,250  MHz  and  2:1  at 
14.000.  He  planned  to 
lengthen  it  a  couple  of  inch- 
es. 

He  worked  EI2EC  with  a 
barefoot  TS-820S.  He  then 
called  "CQ  Pacific"  and 
landed  VK1DH. 

He  wrote,  in  part  ''Now 
let  the  guys  know  that  the 
antenna  can  be  fed  with 
coax  — with  low  swr,  too„  It 
saves  wear  and  tear  on  tun- 
ers and  tuning.  I  like  it,  and 


so  does  the  DX/'  More  later 
on  the  feedpoint. 

Ron  Chiappari  N6AUV 
put  the  antenna  up  with 
three  elements  on  40  me- 
ters and  fed  it  at  the  top 
with  coax;  he  phoned  me 
from  California  to  tell  me 
about  it.  He  said  it  tuned  up 
easily  and  was  1 :1  at  the  de- 
sign frequency. 

Merl  W9ZSI  built  the  an- 
tenna with  voltage  feed  and 
wrote  me  that  it  was  a  great 
antenna.  I  then  told  him  to 
try  current  feed,  and  he  said 
it  tuned  up  perfectly  1:1  at 
14.250  MHz,  He  is  now  go- 
ing to  put  up  another  com- 
plete Bobtail  and  phase  the 
pair  with  quarter-wave 
spacing,  driving  both  anten- 
nas. 

Bill  WaVFB  in  Elyria, 
Ohio,  wrote  to  say  that  he 
was  feeding  the  center  ele- 
ment voltage-fed  with 
open-wire  iadder  line  on 
80/20/15/10  and  then  tied 
the  two  feeders  together  for 
a  Bobtail  on  40. 

Dave  W7TO  wrote  me 
that  he  had  talked  one 
evening   to    Bob   K8FN    in 


Troy,  Ohio,  who  had  the 
strongest  signal  from  the 
east  one  night  while  run- 
ning only  25  Watts.  Of 
course  I  wrote  Bob,  and  he 
said  his  Bobtail  was  sus- 
pended from  three  towers, 
and  he  had  hung  old  tires  at 
the  bottom  of  the  vertical 
wires  so  that  he  could  mow 
under  them.  How  about 
that? 

t  also  received  a  letter 
from  "judge"  Ganzer 
K7SCO  who  has  written 
books  on  antennas.  He  said 
he  calls  this  type  of  current 
top-fed  antennas  "black- 
top antennas"  because  they 
do  not  have  to  use  buried 
radials  in  the  ground. 

You  may  have  guessed  — 
there  are  no  grounds  on  the 
top-fed  antennas.  The  cen- 
ter of  the  coax  goes  to  the 
top  of  the  vertical  in  the 
center,  or  at  one  end  (as  1 
do),  and  the  shield  goes  to 
the  flat-top  horizontal  sec- 
tion. 

I  received  a  surprising 
number  of  letters  from  peo- 
ple merely  telling  me  that 
they  had  used  the  antenna 


and  that  I  was  right  about  \t 
All  agreed  that  it  was  a 
quiet  antenna,  and  some 
wondered  why.  Verticals 
are  not  usually  quiet. 

It  is  a  long-range  antenna 
and  is  at  its  best  when  the 
path  exceeds  2500  miles. 

This  is  important— when 
you  feed  it,  connect  the 
center  of  the  coax  to  the 
vertical.  I  first  thought  I 
would  run  the  coax  up  the 
center  of  the  quarter-wave 
tubing  and  feed  the  top  sec- 
tion, with  the  shield  going 
to  the  vertical  as  in  the  case 
of  the  balun.  This  might 
work,  but  it  would  change 
the  phasing.  The  three  verti- 
cals are  in  phase  because 
the  two  top  sections  are 
cancelled  out  when  center- 
fed. 

1  am  using  mine  with  the 
coax  to  the  top  of  the  end 
vertical  because  it  is  more 
convenient.  I  believe  that 
the  pattern  is  skewed 
toward  the  west  (driven) 
vertical  and  that  this  meth- 
od is  related  to  a  full-wave 
longwire,  I  get  strong  re- 
ports from  both  the  SW  Pa- 


110     73  Magazine  •  December,  1980 


cific  area  and  the  NE  Euro 
pean  area.  This  happens  to 
suit  me  fine.  1  think  my  pat- 
tern is  a  four-leaf-clover 
pattern  with  the  accent  on 
the  western  lobes,  but  I  can- 
not prove  this  by  driving 
around  locally  with  a  field- 
strength  meter  for  a  pattern 
measurement 

Most  of  the  hams  who 
wrote  to  me  used  the  usual 
formula  and  made  the  top 
sections  33'  long  and  the 
verticals  16'  b'\  I  used  34'  at 
the  top  for  each  section,  as 
Jim  Cray  did,  and  tried  the 
verticals  at  17'  3",  but  I  had 
to  cut  the  verticals  back  to 
16'  b''  to  get  the  swr  to  1:1. 
In  the  usual  manner  of 
phased  verticals,  I  believe 
that  the  length  of  the  top 
sections  is  uncritical,  as  in 
the  spacing  of  phased  verti- 
cals. It  affects  the  pattern 
but  not  the  resonance.  The 
antenna  is  tuned  to  reso- 
nance with  the  vertical  radi- 
ators. 


Now  you  know  the  rest  of 
the  story  No  grounds;  top- 
fed  with  coax;  tune  the  ver* 
tical  sections.  However, 
Ron  N6AUV  said  that  no 
verticals  worked  well  at  his 
location  in  California  be- 
cause of  poor  grounds  1 
told  him  to  try  a  method 
which  I  advised  a  friend  in 
Connecticut  to  use  one 
time:  Lay  a  roll  of  fence 
wire  under  the  antenna.  He 
used  chicken  wire  and  it 
worked  beautifully.  No 
connection  to  the  antennas 
—  just  a  reflecting  surface. 
You  can  buy  green  vinyl- 
covered  fence  wire  now 
and  lay  it  on  the  grass.  It 
blends  with  the  grass  and 
you  can  mow  over  it 

I  noticed  one  thing  — 
most  of  the  letters  were 
from  very  experienced 
hams,  not  newcomers.  I 
hope  some  new  people  will 
try  it  and  let  me  know,  now 
that  voltage  feed  is  not  nec- 
essary, ■ 


Oi  S  ^  41  O 


^PP  ^m 


>  i    ^  *  ^  G^ 

Z  ^    ^  O   (D  B  c 

1  '    m  ^  ^  O  -r: 


Ji-   ^ 


^a 


5^ 


u 


—    an    ™ 


Q)  $  ra 
^  m  &  H5  ^ 
^  —  i?  Qfli  c  O 

g  O  --  ««  «  ^O 


9  m 


0 

c 


Ji       i       2  JE 


1  1^ 


CD 


i 


RAPID  MOBILE  CHARGER 

The  DEB-TED  Rapid  Mobile  Charger  is  a 

constant  voltage  charger  that  will  charge 

your  batteries  off  a  12  Volt  source  in  4-6 

hours.  You  may  use  the  charger  at  all 

tfmes,  this  includes  transmit  and  receive 
^periods.  It  is  equipped  with  a  cigarette 
/r  lighter  plug  on  the  input  side  and  the 
Ji  appropriate  charging  plug  on  the  output 
^  side.  Models  available  now  for  ine  Kenwood  TR2400.  Yaesu  207R,  Tempo 

SI.  S2.  SSand  tne  Wilson  Mark  (I  and  tV.  Otner  models  available  also 

please  call  or  write  for  info S34.95. 


COMING  SOON  THE  NEW  AC  VERSION 


<{  VEHICLE  INTRUSION  ALARM 

^  An  easy  lo  assemble  and  install  kit  that  offers  options  not  normally  found 
R  in  other  alarm  systems.  Hidden  switcn  mounts  under  the  dasti.  Kit  nas 
/f  provisions  for  sensors  and  remote  control  switch,  Programmable  lime 
>  delays  for  exit,  entry  and  alarm  periods.  Basic  hook-up  utilizes  dome  lignt 
Jt  circuit  activating  when  doors  are  opened.  The  alarm  will  drive  a  siren  or 
Jt  pulse  horn  at  a  1HZ  rate.  Not  prone  to  false  alarm  do  to  reliable  CMOS 
([  Circuitry,  No  external  switcn  required'  Complete  kit  wrtn  easy  to  follow 

^  instructions  and  diagrams S12.95 

rf  Wired  and  Tested , ...  S19.9" 


"SEETHE  WORKS' 
CLOCK 

OUR    EASIEST    CLOCK    TO 
ASSEMBLE! 

6  Digits  12  or  24  Hour  Format 
Clock  rests  between  two 
pieces  of  clear  plesiglas  A 
GREAT  CONVERSATION  PIECE' 
Kit  is  complete  includmg  top 

quality  PC  board,  all  componets,  pre-cut  and  drilled 
plexjgjas  and  all  hardware  .-.-.......,,,  .329.95 

Wired  and  Tested  ..-..,,,.,...,,,....-,,  .839.95 


3" 


^ 

<§ 


Co 


MODEl  5314  CLOCK  KIT  12  or  24  hour  format  5  large 
/  5  Digits.  Kit  is  complete  with  all  parts,  pc  board  and 
custom  designed  cabinet.  (Specify  Wtiit  or  Black) 


3) 

3) 

3) 

3> 

3> 

J) 

3) 
3) 
3) 

3) 


DEBCO     ELECTRONICS 
Q  f  ^         P.O.  BOX    9169 

^INCINNATI,OHIO  45209 


1^330 


m<i^ 


Phone:  (513)  731-7220 


Add  5%  Snipping  for  U.S. 
&  Canada 

All  foreign  orders  add  10^'n 
COD  orders  add  S125 
Master  Charge  and  Visa 


Orders  under  S20.00  add 

S1.00  n  and  ling 

Ohio  residents  add  4' >%  Tax 


Welcome 


CALL  OR  WRITE  FOR  CATALOG 


i^  Reader  Service— $ee  page  226 


73  Magazine  •  December,  1980    111 


Single-Tone  Paging  for  Wilson  HTs 

—  simple  circuit  should  work  with  many  rigs 


Fred  Siudenbvrg  W4BF 
1305  f  Norhik 
Tampa  Ft  3J604 

The  small  size  of  the  new 
generation  of  two- 
meter  HTs  permits  them  to 
be  carried  almost  any- 
where,  giving  instant  com- 
munications capability  ei- 
ther direct  or  through  re- 
peaters. In  my  specific  ap- 
lication,  my  wife  and  I  use 
Wilsori  MK  lis  to  keep  in 
touch  on  an  unused  simplex 
frequency,  and  the  channel 
can  be  monitored  constant- 
ly   for   any   calls    to   each 


other.  Sometimes  we  are 
too  far  apart  for  reliable 
simplex  communications, 
however,  and  must  switch 
over  to  one  of  the  local  re- 
peaters. Naturally,  the 
wide-coverage  repeaters 
are  fairly  busy,  and  moni- 
tormg  all  the  repeater  activ- 
ity for  a  specific  call  is  very 
distracting,  especially  in  a 
business  meeting  or  restau- 
rant What  we  each  needed 
was  a  way  to  be  alerted  to 
an  incoming  call  without 
constant  attention  to  the 
HT, 

Selective  Calling 

Commercial  users  solved 


•Tl-O  -t 


-^   > 


SOUELCH 
tONTHOL 


Rjt    AUOtO    IN  yPi^ 


TX  AUDIO   OyT  vM 


4iHOUfff> 


SQUEUCH       ^^* 

tC57/R4ftJ  ^ 


Fig.  1.  Single-tone  encoder-decoder  for  the  Wilson  h4K  11/ 

tv. 


this  problem  many  years 
ago  by  the  use  of  selective 
calling  Selective  calling 
permits  a  receiver  to  moni- 
tor a  frequency  for  calls 
and  unsquelch  only  when 
specifically  addressed 
Thus,  a  user  can  go  about 
his  business  without  any 
conscious  attention  to  the 
receiver  and  yet  imme- 
diately be  alerted  to  any  in- 
coming call  The  most  com* 
mon  form  of  selective  call- 
ing used  in  commercial  pag- 
ing  applications  is  some 
form  of  two-tone  sequential 
encoding-decoding.  This  is 
accomplished  by  transmit- 
ting an  rf  carrier  which  is 
modulated  by  a  series  of 
two  audio  tones.  Each  pag- 
ing recipient  carries  a  re- 
ceiver that  responds  to  a 
particular  sequence  of  dif- 
ferent audio  tones.  The  re- 
ceiver remains  muted  until 
the  proper  tones  are  re- 
ceived, after  which  an  au- 
dible alert  tone  is  pro- 
duced. In  the  case  of  a  tone- 
only  page,  this  alert  tone  is 
a  signal  for  the  paged  per- 
son to  perform  some  pre- 
arranged action,  such  as 
calling  a  telephone  number 
or  reportmg  to  a  specific  lo- 
cation. For  a  tone  and  voice 
page,  the  alerting  tone  is 
followed  by  a  voice  mes- 
sage. The  decoders  in  the 
receiver    are    immune    to 


false  alarms  by  virtue  of  the 
sequencing  requirement, 
decoder  bandwidth,  and 
slow  response  time  Typi- 
cally, over  100  different 
codes  are  available  on  any 
given  frequency. 

Adding  a  suitable  high- 
performance  sequential 
tone  decoder  to  an  already 
crowded  HT  is  not  easy,  un- 
fortunately, and  the  prob- 
lem is  further  complicated 
by  the  need  for  a  compat- 
ible encoder  when  the  sig- 
naling of  another  unit  in  the 
network  is  required* 

Single-Tone  Paging 

For  many  amateur  ap- 
plications,  large  numbers  of 
different  signaling  codes  on 
any  given  channel  are  not 
required  and  a  simpler  form 
of  selective  calling  can  be 
used.  Encoding  and  decod- 
ing a  single  audio  tone  can 
be  implemented  with  a 
minimum  amount  of  cir- 
cuitry and  can  provide  very 
effective  results  if  certain 
precautions  are  taken.  As  in 
the  case  of  sequential  tone 
decoding,  the  response 
time  of  the  decoder  must 
be  slow  so  that  voice  or 
other  momentary  in-band 
signals  do  not  trigger  the 
squelch  Additionally,  the 
frequency  separation  of  the 
different  tone  frequencies 
must   be  compatible  with 


112     73  Magazine  •  December,  1980 


low-cost  decoders.  Close 
frequency  spacings  allow 
more  indivtdual  codes,  but 

require  tighter  bandwidth 
control  in  the  decoder  and 
encoder,  complicating  the 
design  and  increasing  the 
sue  and  cost. 

White    researching    this 
problem,  I  noticed  that  the 
eight  frequencies   used    in 
touchtone^^  signaling  (as- 
suming 16  digits}  use  10% 
frequency  spacing  for  each 
of  the  4  high-group  and  4 
low-group  tones.  Using  this 
as    a    starting    point,    the 
group   of    tones   shown    in 
Table  1    was   developed. 
Note    that    all    the    fre- 
quencies have  a  10%  offset 
from    each   adjacent   fre- 
quency,   except    for    the 
1075-Hz  tone.  This  was  ar- 
bitrarily chosen  to  be  mid- 
way from  the  941 -Hz  and 
1209-Hz    touchtone    fre- 
quencies.   Eighteen    dif- 
ferent  audio   tones   within 
the  normal  voice  band  per- 
mit up  to  18  different  pag- 
ing networks  to  operate  on 
any  given  channel  By  using 
tones    in    the   voice   band, 
as  opposed  to  subaudible 
tones,    repeaters   may    be 
used  as  the  paging  transmit- 
ter  since   the   originating 
tone  can  be  transmitted  by 
any  station  capable  of  ac- 
cessing   the    repeater.    Of 
course,  the  system  will  also 
work  on  simplex  channels. 

There  is  no  advantage  in 
using  the  8  touchtone  fre^ 
quencies  in  this  plan,  since 
in  normal  autopatch  use 
any  specific  tone  is  usually 
transmitted  for  less  than  1 
second,  and  a  3-second  re- 
sponse time  on  the  single- 
tone  decoder  allows  it  to  ef- 
fectively ignore  the  single 
tone  associated  with  the 
dual-tone  touchtone  signal. 
Actually,  there  is  some  ad- 
vantage to  using  touchtone 
frequencies  in  this  tone 
plan  since  any  of  the  8  users 
of  these  frequencies  can  be 
paged  by  anyone  equipped 
with  a  touchtone  HT  or  by 
use  of  a  touchtone  phone 
on  a  reverse  autopatch.  Re- 
peater groups  might  want 


to  assign  these  tones  to  key 
indrviduals  in  the  organiza- 
tion such  as  members  of  the 
engineering    committee   or 

emergency  coordinators. 

Tone  Coordination 

In  order  for  this  tone  plan 
to  be  successful,  some  form 
of  tone  coordination  on  any 
given  channel  is  necessary. 
Since  most  repeaters  are 
operated  by  well-organized 
groups,  the  18  available 
tones  can  be  assigned  and 
their  use  administered  in 
any  manner  that  suits  the 
group.  The  main  considera- 
tion is  to  avoid  duplication 
of  tones  so  that  users  of  the 
service  are  not  bothered  by 
unwanted  pages. 

Circuit  Design 

I    have    had    excellent 
results  using  the  single  tone 
encoder-decoder  shown  in 
Fig    1.  The  circuit  uses  an 
NE567  tone-decoder  chip  to 
detect  one  of  the  18  dif- 
ferent   tones.    The    filter 
bandwidth    is    compatible 
with  the  10%  tone  separa- 
tion, and  the  operating  fre- 
quency can  be  set  to  any  of 
the  18  tones  by  the  adjust- 
ment of  R4.  In  addition,  the 
circuit   also  generates    the 
exact    frequency    which    it 
decodes,  permitting  the  en- 
coder  to   alert   any   other 
receiver  in   the  same  net- 
work   The  circuit  is  inserv 
sitive  to  voltage  variations 
from   7.5   to  16  volts  and 
varies  less  than  1  %  in  fre- 
quency over  ihe   —  10°4o- 
60°C  temperature  range. 

Operation  and  Circuit 
Description 

As  installed  in  my  Wilson 
MK  II,  the  decoder  is 
activated  whenever  the 
squelch  control  is  switched 
to  the  Tone  position.  This 
tone  feature  was  intended 
by  Wilson  to  activate  a  sub- 
audible  tone  squelch,  but  it 
works  fine  for  this  applica- 
tion With  the  squelch  con- 
trol in  this  position,  the  nor- 
mal carrier  squelch  is  dis- 
abled, but  the  receiver  re- 
mains squelched  by  the  sat- 


Fig.  2.  full-size  layout  of  PCS  for  the  single-tone  encoder- 
decodef. 


•*t    *a   •a 


f   I 


T 


ST 


iJi 


-^\- 


f^f> 


-7I 


«» 


Fig.  3.  Component  iayout 


urated  output  from  Q2  in 
the  decoder,  Whenever  a 
signal  appears  on  frequen- 
cy modulated  by  the  cor- 
rect tone,  the  output  of  U1 
goes  low.  After  about  3 
seconds,  as  determined  by 
C6  and  R6,  the  collector  of 
Q2  goes  high  and  the  MK  II 
unsquelches.  Once  un- 
squelched,  the  activating 
tone  is  heard  in  the  speaker 
indicating  a  page  The 
receiver  squelches  as  soon 
as  the  rf  input  or  tone  is  re- 
moved. Once  the  alert  tone 
is  heard,  the  squelch  con- 
trol is  rotated  to  the  normal 
carrier  squelch  position  and 
the  frequency  monitored 
for  information  from  the 
paging  station,  and  two- 
way  contact  can  be  carried 
out  if  desired.  If  paging  of 


Tone  Channel 

Frequency 

1 

515 

2 

570 

'   3 

630 

4 

697  \ 

5 

770  ( 

6 

952  I 

7 

941  / 

8 

1075 

9 

1209  ^ 

10 

1336  ( 

11 

1447  I 

12 

1633/ 

13 

1805 

14 

1995 

15 

2205 

16 

2437 

17 

2694 

18 

2977 

another  station  in  the  same 
tone  network  is  desired,  one 
first  checks  for  a  clear  chan- 
nel, identifies,  and  then 
transmits  a  5-second  tone 
by  switching  back  to  the 
Tone  position  while  keying 
the  MK  II.  The  5-second 
tone  transmission  allows 
about  2  seconds  of  the  tone 
to  be  heard  in  the  paged 
receiver. 

Construction 

The  entire  encoder- 
decoder  fits  on  one  single- 
sided  PCB.  A  full-size 
layout  of  the  board  is 
shown  in  Fig.  2  and  the  parts 
list  is  shown  in  Table  2.  All 
the  parts  are  available  from 
advertisers  in  73  or  most 
Radio  Shack  stores.  I've 
also  made  arrangements  for 


Low-groop  touchtone 


High-group  touctitone 


Table  h 


73  Magazme  •  DecemUef*  1980     tl3 


ORBIT  is  the  Official  Journal  for  the 
Radio  Amateur  Satellite  Corporation 
(AMSAT),  P.O.  Box  27,  Washington,  DC 
20047.  Please  write  for  application. 

For  a  FREE  SAMPLE  COPY  please 
send  S1  to  cover  First  Class  Postage 
and  handling  to:  Orbit,  221  Long 
Swamp  Road,  Wolcott  CT  06716, 


the  PCB  alone,  or  a  com- 

ptete  kit,  to  be  made 
available  from  a  source 
listed  in  the  parts  list.  Men- 
tion the  ST  Encoder- 
Decoder  when  ordering. 

All  the  parts  are  mounted 
as  shown  in  Fig.  3.  Note  that 
the  resistors  are  mounted 
vertically  to  save  space.  If 
yourMK  U  orMK  IV  has  the 
Hi-Lo  power  switch,  it  will 
be  necessary  to  notch  out 
the  rear  corner  of  \hi*  PCB 
to  provide  clearance  The 
solid  copper  area  bordering 
the  board  name  provides 
the  proper  guidelines  for 
this  operation.  Six  #26 
stranded  wires  about  7" 
long  are  connected  to  the 
unit  for  testing  and  even- 
tual connection  to  the  MK 
II  orMK  IV  PCB, 

Testing 

To  avoid  any  extra  trou- 
ble, I  recommend  testing 
the  encoder-decoder  exter- 
nally and  then  connecting  it 
to   the   MK    II   or  MK    IV. 


Referring  again  to  Fig.  1, 
connect  +12  volts  to  PI 
and  ground  to  P5.  Connect 
a  frequency  counter  to  P4 
and  adjust  R4  for  the  de- 
sired tone  frequency.  Then 
apply  a  100-mV  rms  audio 
signal  at  the  desired  tone 
frequency  to  P3,  Before  the 
tone  is  applied,  the  base  of 
Q2  should  be  at  .7  volts. 
This  should  drop  to  0  volts 
about  3  seconds  after  the 
tone  is  applied.  Verify  that 
the  on/off  switch  works  by 
grounding  P2.  The  transmit 
output  signal  at  P4  should 
disappear,  and  the  base  of 
Q2  will  go  to  0  volts.  Once 
the  board  has  been  tested, 
insulate  the  entire  bottom 
of  the  PCB  with  electrical  or 
vinyl  tape  to  prevent  shorts 
when  it  is  installed  in  the 
MK  II  orMK  IV. 

Installation 

The  first  step  is  to 
remove  the  top  and  bottom 
covers  from  the  MK  It  or 
MK  IV  to  gain  access  to  the 


switch  contacts  on  the 
squelch  control.  Run  a 
jumper  from  one  of  the 
switch  contacts  to  the 
ground  plane  on  the  main 
PCB  of  the  MK  11  or  MK  IV. 
Next,  connect  the  wire  from 
P2  to  the  other  switch  con- 
tact. Note  that  this  wire 
must  be  routed  from  the 
backside  of  the  PCB  to  the 
switch  contact  on  the 
squelch  control  The  con 
nections  of  each  of  the 
leads  from  the  encoder- 
decoder  to  the  MK  II  is 
shown  in  Fig.  1.  In  each 
case,  the  reference  desig- 
nator shown  on  the  sche- 
matic beside  each  lead 
number  refers  to  the  cor^ 
nection  point  on  the  MK  IL 
These  points  are  best 
located  by  referring  to  the 
circuit  board  overlay  on 
page  18  of  the  Operating 
and  Service  Manual  for  the 
MK  l!/MK  IV. 

The  encoder-decoder  is 
secured  inside  the  radio  by 
pressure  from  the  top 
cover.  Now,  carefully 
reinstall  the  top  and  bot- 
tom covers  and  check  for 
proper  operation.  If  you 
have  a  deviation  meter, 
check  for  about  3"kHz  tone 
deviation.  This  is  more  than 
adequate  since  the  decoder 
will  function  with  devia- 
tions from  transmitters  as 
low  as  1.5  kHz.  Have  some- 
one transmit  a  signal  with 
the  correct  tone  frequency 
and  check  for  proper  re- 
ceiver operation.  The  re- 
ceiver should  unsquelch 
about  2.5  seconds  after  the 


tone  is  transmitted. 

How  Does  It  Perform? 

I  can  monitor  a  busy 
repeater  all  day  and  never 
once  hear  the  squelch 
break,  yet  as  soon  as  I  am 
paged,  the  paging  tone 
comes  through  loud  and 
clear.  I've  had  the  oppor- 
tunity to  try  the  page 
feature  through  a  number 
of  different  repealers  and  it 
has  never  failed  to  work. 
When  readable  signals  are 
present,  the  encoder-de- 
coder works  every  time. 

Incidentally,  when 
switched  On,  the  encoder- 
decoder  adds  about  6  mA 
of  additional  current  drain. 
This  is  of  no  consequence 
since  the  average  drain  in 
the  Tone  position  is  much 
less  than  in  normal  squelch 
because  battery  life  is 
directly  proportional  to  the 
amount  of  audio  coming 
from  the  speaker.  With  the 
decoder  turned  on^  nothing 
is  ever  heard  except  the 
desired  paging  tone. 

Use  of  Encoder-Decoder 
in  Other  Equipment 

I  haven't  had  the  chance 
to  investigate  the  use  of  the 
encoder-decoder  in  other 
equipment,  but  aside  from 
physical  constraints,  the 
unit  should  work  with  most 
negative-ground  solid  state 
equipment.  !  will  be  glad  to 
answer  any  specific  ques- 
tions on  interfacing  it  with 
your  rig  if  you  include  a 
copy  of  the  schematic  and 
an  SASE,B 


R1,R5,  R3 

R2 

R4 

R6,  n? 

C1,C7 

C2,  C3 

C4 

C5 

C6 

01 

D2 

U1 

Q1.Q2 


Parts  List 
22k,  V4  W 
470,  V4  W 
25k  Pot 
180k,  V4  W 
10  ^F.  16  V 
0*01  ceramic 
0-1  mylar™ 

1  |jF,  35  V 
2.2  jnF.  35  V 
1N414e 

1N750A 
NE567N 


Radio  Shack  271-336 

Radio  Shack  272-1411 

Radio  Shack  272-1053 
Radio  Shack  27M 406 
Radio  Shack  272-1407 


2N2222 

A  complete  parts  kit,  including  drilled  and  plated  PCB,  is  available 
from  Coggin  Mfg..  P.O.  Box  44,  Cedar  Rapids  I A  52404,  S  15.95 
(postpaid).  The  PCB  alone  is  $3.50  postpaid. 

Table  Z 


114     73  Magazine  •  December.  1980 


Have  you  ever  w^ondered 

why  the  best  ham  bargains 
are  advertised  in  73? 


You  11  find  a  wider  selection  of  ham  bargains 
,  .  ,and  lower  prices  in  73,  because  73^s 
readers  buy  far  more  than  readers  of  other 
ham  magazines. 


THE  LEADING  EDGE 

That  shouldn't  come  as  a  surprise  to  you .  .  .  For  twenty 
years  we've  been  publishing  more  construction  projects  and 

articles  than  any  other  ham  magazine,  so  it  is  natural  for 
the  active  hams  to  read  73. .  .  and  buv  from  the  ads. 

The  readers  of  73  catch  the  leading  edge,  through  side- 
band in  the  early  60's,  then  solid  state  in  the  mid-60's,  FM 
and  repeaters  in  the  early  70's,  .  ,  SSTV,  ATV,  RTTi'  and 
all  other  special  modes  have  received  more  coverage  in  73 
than  all  other  ham  magazines  combined, 

NEXT  YEAR  WE'LL  BE  PUSHLNG  • . . 

In  the  next  year  or  so,  we'll  be  pushing  for  amateur 
experimentation  and  pioneering  with  new  modes  of  com- 
munications, via  computer,  automatic  identification, 
satellite,  \^ideband  techniques^  synchronous  detectors, 
time  slicing.  Never  before  was  a  point  in  time  so  esciting  to 
contemplate,  and  with  73  you  can  keep  up  with  the  new 
ideas  and  changes. 

We'll  also  be  pushing  for  increased  pressure  on  the  FCC 
for  better  and  more  responsive  rules,  for  a  return  to  a  na- 
tional growth  and  for  amateur  radio  development  in  as 
many  of  the  emerging  nations  as  possible. 


Wayne  Green 


ALL  OF  THIS  IS  MADE  POSSIBLE  BY  YOU 

All  of  this  is  made  possible  by  you  reading  73  and  getting 
your  friends  and  club  members  to  subscribe  to  73.  I  admit 
that  we're  not  really  pushing  the  radio  relay  of  messages, 
since  that  is  more  geared  to  the  1920's  than  the  1980*s  and  is 
more  likely  than  other  activities  to  cause  troubles  with 
foreign  governments  nervous  about  potential  lost  telephone 
revenues.  We're  looking  toward  the  1990*s,  with  over  one 
million  hams  in  our  countr>'  using  state  of  the  art  com- 
munications techniques  to  keep  in  touch  with  hams 
worldwide. 

YEAR  2000? 

What  will  amateur  radio  be  like  in  the  year  2000?  We 
can't  really  even  imagine,  except  that  we  know  it  will  be 
different  from  1980.  .  probably  as  different  as  amateur 
radio  is  todav  from  what  it  was  in  I960,  when  FM  and 
repeaters  were  all  but  unknowTi,  and  AM  was  still  going 
strong  on  our  phone  bands.  A  frecjuency  synthesizer  re* 
quired  over  a  hundred  tubes  and  radioteletype  circuits 
were  larger  than  the  printers.  You  can  be  sure  that  73  will 
be  in  the  vanguard  of  the  developments  to  come .  ,  ,  repor- 
ting on  them  and  giving  you  the  information  so  you  can 
participate. 


a  Bill  me  for  one  year  of  73  at  $25,00 


n  New  Subscription         D  Renewal 


Name 


Address 
City 


State 


Zip. 


Canadian  $27.00/1  year  only,  US  funds  Foreign  $35.00/1  year  only,  US  funds 

Please  allow  4-6  weeks  for  delivery. 
73  Magazine*  PO  Box  931  •  Farmingdale  NY  11737 


3eoe6 


73  Magazine  •   December,  1980     115 


WILSON  SYSTEMS,  INC. 

CHRISTMAS  SPECIAL  SALE    systemsb 


CALL 

FACTORY  DIRECT 

1  -800-634-6898 


REGULAR  PRICE 
•219« 

SALE  PRICE 


A  trap  baded  antenna  that  performs  fike  a  mono- 
banderi  Thaf  s  the  characteristic  of  this  six  element 
three  band  beam.  Through  the  use  of  wide  spacing 
and  interlacing  of  elements,  the  following  is  possi- 
ble: three  active  eiements  on  20,  three  active  ele- 
ments on  15,  and  four  active  elements  on  1 0  meters. 
No  need  to  run  separate  coax  feed  lines  for  each 
band,  as  the  bandswitching  is  aulomaiicaily  made 
via  the  HiglvQ  Wilson  traps.  Designed  to  handle 
the  maximum  legal  power,  the  traps  are  capped  at 
each  end  to  provide  a  weather-proof  seal  against 
rain  and  dust.  The  special  High-Q  traps  are  the 
strongesi  available  in  the  industry  today. 


cw. 


lvl> 


SWR  CURVES 


■  *  #■+  ■■ 


14 
WTIH 


:=3: 


L^l 


^ 


t]        !■!       Mi       m 


4»m* 


MM 


II 


ta.  l_ 


Xz 


rt-^ 


i 


^^^-^ 


SPECIFICATIONS 

Band  MH2 , 14^21-2a 

MaKimum  power  input Le§al  Lirnit 

Gain  (dbd]i. .,,  ^  «.**»,«,......... .  9  db 

VSWR  &  rnonafice  ..,,,...,.,.«  1^1 

hnpedonca ,,,*,,  +  ...  SOotwn 

fiB Bsk?. .,..,,  20 db or Betu^ 


Boom  tO.D  «  LeogtW 


*-««*■*» 'I 


Jl* 


«1 


t» 


mt 


ni 


n* 


^  It 


14 


^ 


-^^r^: 


',&_ 


«M  >*t  H4  UJ 

mm 


Turning  flmlNA  ■ 
Manmum  Man  DiHTWtst 
Sitffacft  Arsa  -  .,.,_* « ^ . , 


3*iZ4'2T4' 


H« 


Ml 


MsicnnQ  MBtfuil   ,  -  r .  -  BM^ 

WmdLoading  #  86  mp^ 21^ ibs. 

Mtawmum  Wind  Sufvivil 1^00  rnp*i 

F««HJ  MeLhod .        B«kin  (Suppfied) 

As&emblBd  Weighi  j^pproii-}  ^ .  *. ,  53  lbs. 
Shipping  Weight  Eapprox. J  .......  62  lbs. 


Compare  the  SY-36  &  SY-33  with  others 


^ 


BRAND 
CC 


Compare  the  size  and  strength  of  the  boom 

to  element  clamps.  See  who  offers  the  largest 

and  heaviest  duty.  Which  would  you  prefer? 


SP' 


:0\ 


CALL 


FACTORY  DIRECT 
1  -800-634-6898 


J 


BRAND 
HG 


-WILSON 
SYSTEMS 


Wilson  Systems  traps  offer  a  larger  diameter 

^p  coil  and  a  larger  outside  hausing, 

gfving  excellent  Q  and  power  capabilities. 


EHBn  WILSON 

^U^^mM  SYSTEMS JNC. 

4286  S.  Polaris  Ave.,  Las  Vegas,  Nevada  891 03 


Prices  and  specif  icatiorts  subject  to  chArige  without  notics. 


WILSON  SYSTEMS  INC. 


REGULAR  PRICE 
•104' 


Capable  of  handling  the  Legal  Limit,  the 
SYSTEM  33  is  the  finest  compact  tri- 
bander  available  to  the  amateur. 

Designed  and  produced  by  one  of  the 
world's  largest  antenna  manufacturers,  the 
traditional  quality  of  workmanship  and 
materials  excels  with  the  SYSTEM  3i 

The  boom-to^iement  mount  consists  of 
two  MB"  thick  formed  aluminum  plates  that 
wifl  provide  mofe  cfamping  and  holding 
strength  to  prevent  element  misalignment 


Superior  clamping  power  ts  obtained  with 
the  use  of  a  rugged  1/4"  thick  aluminum 
plate  for  boom  to  mast  mounting. 

The  use  of  large  diameter  High-Q  Traps  in 
the  SYSTEM  33  makes  it  a  high  performing 
tri-bander  and  at  a  very  economicaf  price. 

A  complete  step-by-step  illustrated  in- 
struction manual  guides  you  to  easy 
assembly  and  the  tightweight  antenna  makes 
installation  of  the  SYSTEM  33  quick  and 
simple. 


SPECIRCATIONS 


Band  MHz, .,,, 

Mdx.  power  input  . . , 
Cain  {dbdf . .  * 

VSWR  at  resonance. 
Impedance  , 


,  14-21  28 

Legal  limit 
o 

■       ■       ii      t       ■       ■       ^  ^^ 

1  21 

■  ■II"  *       '   ^  '        T 

,  50  ohms 
.  up  to  20 

CW 


Boom  (0,D.  X  length}2"  x  14'4" 
No.  elements ............      3 

Longest  element 27'4" 

Turning    radius 15'9" 

MaK.  mast  diameter.  ,2"  O.D* 
Surface  area .5.7  sq.  ft. 

ACTUAL  SWR  CURVES 


Wind  to3d  @  80  mph  .  .  1T4ibs 

Assembled  Wi. 37  lbs 

Shipping  Wt _  42  lbs 

Direct  52  ohm  feed 

no  balun  required 
Max  wind  survival  . , ,  100  mph 


ItHfTtRt 


l»MTf« 


:=?: 


-• ■  T  I 


z? 


^ 


Li              8          ..I            .                         ■      ■■    II             _yJ^  i 

■  "Hr  ■      f  *  i^ ^^"^    I  1 


tM     M-f    mt     Jftfr   «u 


40-  T     _J^^\         **  I^TT 


rti 


h*» 


M» 


■4J 


Ntl 


Ml 


The  SY33 


c 


WITH  OTHERS'- 


BRANP 
CC 

eRAMD 
I4& 


SYSTEMS 


Compare  the  size  and  strength  of  the  boom 

to  element  damps.  See  who  offers  the  largest 

and  heaviest  duty.  Which  would  you  prefer? 


Wilson  Systems  traps  offer  a  larger  diameter 

trap  coil  and  a  larger  outside  housing, 

giving  excellent  Q  and  power  capabiHties. 


hegular  price 

SALE  PRICE 

iCQ05 


ADD  40  METERS  TO  YOUR  TRhBAND 

WITH  THE  23S  MK 

-  IN  STOCK  -  *59' 

Now  you  can  have  the  capabilities  of  40-meter  operation  on  the  SYSTEM  36 

and  SYSTEM  33.  Using  the  same  type  high  quality  traps,  the  40-meter  addition 
will  offer  150  KHZ  of  bandwidth.  The  33-6  MK  will  fit  your  present  SY36,  SY33,  or 
SY3  and  use  the  same  single  feed  line, 

The  33-6  MK  adds  approximatefy  15'  to  the  driven  element  of  your  tri-bander,  in- 
creasing the  tuning  radius  by  5  to  6  feet.  This  addition  will  offer  a  rotatable  dipole  at 
the  same  height  of  your  beam. 


W  S  I 


WILSON 

SYSTEMS.  INC. 


Pricn  and  apfctfficflt  j  wv  fubjoct  to  €hm<m  wrthoat  not  let. 

Prices  Effective  1M-80  Chni  12-31-80 


For  Christmas  Special 

Sale  —  Call 

FACTORY  DIRECT 

1  -800-634-6898 


r 


REGULAR  PRICE 
♦65" 

SALE  PRICE 

4  BAND 
TRAP  VERTICAL 
(to -40  METERS) 

No  bandswitchlng 
necessary  with  this 
vertical.  An  excellent 
low  cost  OX  antenna 
with  an  efectricai  quarter 
wavelength  on  each  band 
and  tow  angle  radiation. 
Advanced  design 
provides  low  SWR  and 
exctptionally  flat 
response  across  the  fuM 
wjdth  of  each  band. 

Featured  is  the  Wilson 
large  diameter  High-Q 
traps  which  will  maintain 
resonant  points  with 
varying  temperatures  and 
humiditv. 


Easily  assembled,  the 
WVtA  is  supplied  wrth  a 
base  mount  bracket 
j  to  attach  to  vent  pipe  or 
to  a  mast  driven  in  the 
ground, 

VOTE; 

are  requiTed 

for  peak  operation  or 

above  ground  rT>oyntjng. 

{SeeGR  1  belowl 


SPECIFICATIONS 

19'  total  height 

Self  supporting  —  no  guys 

required 

Weight  —  14  lbs. 

Input  jmpedance    50  fi 

Power  handling  capabilitv: 

LegaJ  Limit 

Two  Hkgh  Q  traps  with  large 

diameter  coils 

Low  angle  radiation 

Omnidirectional 

perforrrrance 

Taper  swaged  alummum 

tubing 

Automatic  bandswttching 

Mas  I  bracket  furnished 

SWR:  1:1:1  or  tess  on  all 

bands 


GR-l 

GROUND 
RADIAL  KIT 


REGULAR  PRICE 
•I4M 

SALE  PRICE 

♦12 


The  GR-1  is  the  complete 
ground  radial  kit  for  the  WV  1  A. 
It  consists  of  1 50 '  of  7/14  alumi- 
num wire,  heavy  duty  egg  in- 
sulators and  mstructions.  The 
GR-1  will  increase  the  efficiency 
of  the  WV-1  by  providing  the 
correct  counterpoise. 


WILSON  SYSTEMS  TOWERS 


-  FACTORY  CHRISTMAS  SALE  - 


REGULAR  PRICE 

•1104" 

SALE  PRICE 

*994 

ST-77B 
Features: 

Max.  Height;  77' 
Mir*.  Height:  24 ' 
Weights  700  lbs. 
Wmch:  1500  lbs. 
Cable:  6400  lbs. 
Requires  RB-77B  & 

wiN  b6  totally 

freestanding 


tor 


REGULAR  PRICE 

SALE  PRICE 


B' 


16^ 


*"  0,0. 


^ 


II  I  I 


*-=^ 


♦579 


MT  61 B 
Featyres: 

Max.  Height:  61' 
Min.  Height:  23^ 
Weight;  450  lbs. 
Winch:  1200  lbs. 
Cable:  4200  lbs. 

No  Guys  required 
when  mounting 
against  house. 

For  completely 
freestanding  in- 
staflation^  use 
RB-618  or 


r 


10' 


3.J  O.P. 


IS" 


4.t  Q.Q. 


6"  O.D. 


20 


J^^^ 


»' 


F8-61B  below,  r| 

I 


REGULAR  PRICE 

•395" 

SALE  PRICE 

*349'" 

TT^SB 
Features: 

Wfax  Height:  45' 
MIn.  Height:  22' 
Weight:  250  lbs. 
Winch:  1200  lbs. 
Cable:  4200  lbs. 

No  Guys  required 
when  mounting 
against  eve  of 
house. 

For  compfet^ly 
freestanding 
installation,  use     ^''■ 
RB-45B  or  FB^BB 
befow. 


'—2' CD. 


ir 


3.S  0  0 


4a'0.D 


to 


-^.  TT--         ft' 


20^ 


tif 


A 


NEWI  Wilfton  Electric  Winch 

Now  you  can  raise  and  lower  your  Wflson  Tower 

electrically.  The  electric  winch  will  replace 

the  hand  operated  vvlnch.  Available  for 

^m-^      ijse  on  the  TT45,  MT^I   and  ST-77 

I 


X^/i 


WIND  LOADING 
Tower    Height    Sq.  Ft. 

ST-77B 

*9 

10       1 

Square 

77 

to 

Footage 
Based  on 
SOMPH 

Wind 

MT61B 

^ 

ie 

r    61 

u 

TT-45B 

3? 

IS 

45 

^^ 

EW^5  nr^si 

BW-61  (MT-61) 
EW'77  (ST  77) 


•249** 

. .  ♦24** 


BASECIiART 

TOWIft 

WIDTH     J 

OiPtH 

TT^SB 

12*x  12' 

30" 

FB-46B 

30" X  30" 

4%' 

RB4SB 

30  "^  jc  30" 

4!4' 

MT-61  B 

18'j(ia* 

4' 

Fa-61B     1 

3'jc3^ 

5>4' 

RB^IQ 

3'  k3' 

SH' 

ST-77a 

Ses  Below 

RB-77B 

3^'  k3^^' 

6' 

Remote  Switch  .  . 

Wtlson  Systems  uses  a  high  strength  carbon  steel  tube  manufactured  especially  for  Wilson  Systems,  It  is 
25%  stronger  than  oDnventEonat  pipe  or  tubing.  The  tubing  size  used  is:  2"  &  3 J^  "-.095;  4%"&  6 "-.125;  8" 
- 134,  All  tubing  is  hot  dip  galvanized.  Top  section  is  2"  0,D.  for  proper  rotor  and  antenna  mounting. 

The  TT'45B  and  MT-61 B  come  complete  with  house  bracket  and  hmged  base  plate  for  against-house  mount- 
fng.  For  totally  freestanding  installation,  use  either  of  the  tilt-over  bases  sliown  below. 

The  ST-77B  cannot  be  mounted  agatnstthe  howse  and  must  be  used  whh  the  rotating  tilt-over  base  RB-77B 
shown  below. 


TILT-OVER  BASES  FOR  TOWERS 


FIXED  BASE 

The  FB  Series  was  designed  to 
provide  an  economical  method  of 
moving  the  tower  away  frorn  the 
house.  It  will  support  the  tower  in 
a  completely  free-standing  vertical 
position,  while  also  having  the 
capabihties  of  titting  the  tower 
over  to  provide  an  easy  access  to 
the  antenna.  The  rotor  mounts  at 
the  top  of  the  tower  in  the  con- 
ventional manner,  and  will  not  ro- 
tate   the    complete    tower. 

FB-45B...112  lbs...*169*" 
FB-61B...ie9  lbs...*244<" 


CHRISTMAS  SPECIAL  SALE 

Call  Factory  Direct 

1  -800-634-6898 


ROTATING  BASE 

The  RB  Series  was  designed  for 
the  Amateur  who  wants  the  add- 
ed converiience  of  being  able  to 
work  on  the  rotor  from  the 
ground  position.  This  series  of 
bases  will  give  that  ease  plus  ro- 
tate the  complete  tower  and  an- 
tenna system  by  the  use  of  a 
heavy  duty  thrust  bearing  at  the 
base  of  the  tower  mounting  posi- 
tion, while  still  being  ^b\^  to  tilt 
the  tower  over  when  desiring  to 
make  changes  on  the  antenna 
system. 

RB  45B...144  lbs...*234^" 
RB-61B...229  lbs...*309^" 
RB-77B...300  Ibs.-.MftS''' 

Order  the  CHRISTMAS  SPECIAL  I 

Prices  Effective  1 M  -80  thf u  1 2-31-80 


\i 


Tilting  thf^  tower  over  is  a 
one-man  task  with  the  Wil- 
son bases,  (Shown  above  is 
the  RB61B.  Rotor  is  not 
included.) 


W  S  I 


WILSON 

SYSTEMS.  INC. 


428«  S.  PolarisAve.  •  Las  Vegas.  Nevada  99103 


WILSON  SYSTEMS,  INC.  PRESENTS 

CHRISTMAS  SPECIAL  THE  SYSTEM  40  TRIBANDER 

3  MONOBAND  ANTENNAS  IN  ONE  -  EACH  WITH  FULL  MONOBAND  PERFORMANCE 


REGULAR  PRICE 

•374« 

CHRISTMAS  SPECIAL 

♦as?*" 


I 


•  FOR  THE  SERIOUS  OXer  WHO  WANTS  MONOBAfv^DERS  ON  10-15.30 

•  FOUR  FULL  SIZE  20  MTR  ELEMENTS  WITH  10  dbd  GAIN  AND  25  db  F  B 

•  FOUR  WIDE  SPACED  15  MTR  ELEMENTS  WITH  10  dbd  GAIN  AND  20  db  F.^a 

•  FIVE  WIDE  SPACED  10  MTR  ELEMENTS  WfTH  1  T.5  dbd  GA*N  AND  20  db  F/B 

•  ONLY  OI^E  FEED  LINE  REQUIRED 

•  HEAVY  DUTY  BALUN  INCLUDED 

•  DESIGNED  WITH  NO  If^TERACTlONS  BFTWEEN  ELEMENTS 

•  ALL  DRIVEN  AND  DIRECTOR  ELEMENTS  ARE  INSULATED  FROM  BOOM 

•  SAME  QUALfTY  HARDWARE  AS  USfO  IN  ALL  WILSON  ANTENNAS 

-SPEOFICATtOm- 


mt       .1  r       n;       Mi       .tt       Jti       Mi       At       jai       iti      m 


Msh.  Pwr,  Input Legal  tmit 

VSWR^  nm .,.. 1.2:1 

ImpedancB  ,..,.,,»,  ^  ,*,»»,,,  +  *  60  ohm 

Feed  Method Batun  Supplied 

Mntchlng  Mtthod ,.,.,,,..  Modified  Beta 

F/B  FlBtkJ Ses  AbhOvB 

Gain  H    - .  1. .  ^  -  =  -  = S«e  Above 


Longftst  Elamerrt* 36 ' 

TufnifiQ  Ridiut , 22  '6 ' 

Soofflii  * . .  ir^  * » 1 1  ■ V . , ,  26 

Sijrfact  Arsa  .  * » , 12.1  iq.  ft. 

WJmJ  Loading  @  flO  mph  ....,,..  309  tb4. 

Asaem.  W«^tJhl  . . , , , .  7S  fba. 

Shipping  Weigh!  . , „  , .  9S  lbs. 


1 

r 

»^ 

^ 

hi: 

"^'^.Hw, 

.^ 

11  ■! 

^'fc^^ 

^ 

^-^^^ 

— '^"^'^m 

' ^-^F d 

1 

. 

J 

1  WILSON  SYSTEMS.  INC.  -  4286  S.  Polaris                FACTORY   DIRECT  ORDER   BLANK                                           Tdl-Fr«0.<tof  Number  1 

,  u»v.,«  NV8,io3  ,702,7^7«,       CHRISTMAS  SPECIAL  SALE     1-800-634-6898  i 

1   Qrv 

M[mJ*<     J  Description 

S^tipfyng 

Prica 

Oty. 

MCNiBl 

r            n 

Shipfiing 

Price    1 

SY40 

10  El*  Tubajidfir  far  10,  IS,  20  Mov 

UPS 

337  95 

RMt 

Refnone  SwiTch  for  EW 

UPS 

2495     1 

SY36 

«  £le.  TnbsHiBr  far  10,  1  §.  20  Wtm. 

UPS 

199  95 

TT45a 

Freestancing  45 '  Tubular  Tower 

TRuac 

3499S    1 

SY33 

3  Be.  Tribwder  fw  10,  15.  20  Mw* 

UPS 

149.95 

RB450 

ROlTtmg  ns5e  Tcv  1  T  -4^  w  tin  ovcf  f efftyre 

TRUCK 

mm  1 

334  MK 

40  Mtr.  Mod  Kft  for  SV33  &  Sy36 

yps 

B9  9§ 

FB45e 

Rxed  Base  toi  TT459  w.iOi  over  fntwe 

Tnucic 

^69  9S   1 

WVIA 

Tnvi^teticBlfGr  10.  15.  20,  40  Miri 

UPS 

59  95 

MT^IB 

Freesianding  61  '  Tufautar  Towv 

TflUCK 

579  95    ' 

GRT 

Ground  Racfialft  fw  WV  ;a 

UPS 

13  9S 

Ra-61B 

Hot^ir^  Basa  Um  MT-CIB  wn«t  ow  lBatiir« 

TRUCK 

30995   ' 

h4420A 

4  Elwnenis  c?n  20  Mrrs 

UFS 

174  95 

F6^1  B       Ffaied  Raw  tor  MT^I  B  witilt  Over  feature 

TRUCK 

244  95  ' 

M'SISA 

5  ElomentB  on  T6  Mtr^ 

UPS 

139  96 

ST-//& 

Reegtvid^  77'  Tubulv  Tovw 

THUCK 

99495  1 

M520A 

5  Eiemeins  on  20  Mira. 

TRUCK 

224  95 

RB-77B 

Bn*»rirk.-i     n  -k^  liii    fi-i^     f^'f'    TTn    i.i.J^iltl      -      -^ —   * ■-■       ■   - 

TRUCK 

nauang  as&m  'ur  z^  i  -  /  /t^  wiiifi  OvK  raanur  e 

46395    I 

M410A 

4  E!ern«nts  on  10  Mtrg. 

UPS 

74^5 

GK46 

Guying  Kit  fear  GT4« 

UPS^THK 

7495  1 

ACCESSORIES 

GK45B 

Guying  Kn  fof  TH&H 

UPSTRK 

€0.96  1 

vx 

Tail  Twister  Rolor 

u**s 

274,^ 

GK-61B 

Gyying  Kit  for  MT41  B 

UPS-TRK 

nm  1 

HD73 

Alliance  Kftavy  Duty  Rotor 

UPS 

109.^ 

GK778 

Guykng  Kft  for  ST  77B 

UPS^TRK 

99.95  1 

Rc-ec 

a/C  Roiof  Cable 

UPS 

lec/tr 

WTBI 

Thrust  B««rir>g  for  TOp  Of  floTetinig  Towers 

UPSTRK 

59.95^ 

RG-SU 

RG  8U  FQpm  Coasial  Cable  -  UKfa  R** 

center  conductor,  11  guage                                       i 

UPS 

2aC/tT. 

Chilatmas  Prices  Effective  Nov.  1  D0c,  31 , 1 SBO               Nevadi 
Shfp  C.O.D.  n     Check  endoBed  P     Charge  to  VfSA  D 

EW45 

Wli^n  Electric  Winch  for  TT^SB 

UPS 

249.95  1 

s  Residents  add  Sfilofl  Tax      1 

EWfll 

Wilson  Electric  Winch  for  MT-61 

UPS 

249.95 

MastflfCharge  G                m 

EW-77 

Wflpon  Electric  Winch  for  ST-77 

UPS 

249,95 

Card 

No 

ExplrHB                              n 

On  Coffxl^f  and  Rawr  Cable,  minimum  order  is  fOO '  and  50 '  multiphs. 

Prices  sr*d  spBCfflc&mns  sub/ecr  to  change  without  notice. 

Nffwty  iSCy  O^y  Umitsd  Wafrafity— Shipping  f^or  Included  In  Above 

Bank  No. 

Sig^nitturi> 

1         ^ 

Ham 

SiTW 

It 

PlwMie                                              ■ 

Zip                                          1 

Prices  and  specif k;aticit«  nAjMH  ei  change  without  nanc&.  m 


IB 


William  L  Thomas  WB9KPT 
3483  Bay  berry  Drive 
Nonhbrook  ii  60062 


Teletext  and  Viewdata: 

Are  You  Ready  for  the 

Information  Boom? 

coming  soon  to  a  living  room  near  you 

video  data  services 


Specially  equipped  TV 
receivers  are  now  avail- 
abfe  to  provide  us  with  cur- 
rent weather,  sports,  news 
headlines,  tonight's  televi- 
sion shows,  local  events  of 
interest,  and  many  other  in- 
teresting bits  and  pieces  of 
infornnation.  The  magic 
word  in  this  scenario  is  in- 
formation. Alnrrost  anything 
of  general  interest,  can  be 
formatted  and  sent  to  your 
home  by  the  systems  to  be 
described  in  this  article. 


In  England,  a  set-top 
adapter  currently  available 
for  this  service  is  priced  at 
$250.  The  cost  of  the  LSI  in- 
tegrated circuits  that  will 
form  the  heart  of  these 
adapters  is  less  than  $50.  I 
feel  that  there  is  the  possi- 
bility of  adapting  this  hard- 
ware, which  will  be  pro- 
duced in  large  volume  for 
consumers,  for  use  on  the 
ham  bands. 

Teletext  is  a  generic  term 
for    television-based    sys- 


Photo  A.  Typical  teleteKt  hardware.  Left  to  right:  Mallard 
module,  remote  control,  and  Texas  Instruments  module. 

120     73  Magazine  •  December,  1980 


terns  broadcasting  pages  of 
information  along  with  the 
normal  TV  signal.  This  in- 
formation is  digitally  en- 
coded and  sent  during  the 
vertical- retrace  interval 
when  the  scan  of  your  TV 
receiver  is  off  screen.  What 
the  viewer  sees  on  the 
screen  of  his  teletext  TV  is  a 
page  of  characters,  40  in  a 
row,  20  to  24  rows,  800  to 
%0  characters  per  page. 
These  characters  can  be 
presented  in  eight  colors, 
including  colored  back- 
grounds. Included  in  the 
character  set  are  all  the  let- 
ters of  the  alphabet  (both 
uppercase  and  lowercase), 
numbers,  punctuation 
marks,  special  symbols,  and 
graphics.  The  graphics  can 
be  as  simple  as  64  special 
graphic  symbols,  called 
mosaic  graphics,  or  higher 
density  if  one  is  willing  to 
pay  the  price. 

Each  page  is  identified 
by  a  page  number  and  typi- 
cally will  be  displayed  on 
the  screen  in  less  than  a 
minute  after  the  desired 
number  is  entered  via  the 
keypad.  Several  hundred 
pages  can  be  transmitted  in 
less  than  a  minute  in  a  serial 
fashion,  one  page  after  an- 


other. The  teletext  adapter 
grabs  the  appropriate  page 
as  it  comes  by  and  immedi- 
ately displays  the  selected 
page  on  the  screen.  Index 
pages  are  provided  to  help 
the  consumer  determine 
pages  of  interest 

Where  does  all  this  infor- 
mation come  from  and  why 
does  the  broadcaster  want 
to  transmit  it  to  your  home? 
One  way  to  answer  this 
question  is  to  consider  tele- 
text as  a  new  publishing  me- 
dium. As  advertising  sup- 
ports most  mass-market 
publishing  efforts,  so  would 
it  play  in  this  one.  As  an  in- 
teresting example,  the  news 
headlines  could  be  brought 
to  you  by  your  local  paper 
in  an  effort  to  sell  you  to- 
day's edition  containing 
more  details  on  the  stories. 
It  is  expected  that  most 
pages  broadcast  by  com- 
mercial TV  stations  would 
include  such  advertising. 

On  the  public  TV  sta- 
tions, information  would  be 
financed  by  the  same 
sources  that  contribute  to 
their  normal  program 
funds.  Obviously,  most  ma- 
jor corporations  and  many 
government  agencies  have 


much  material  that  would 
be  sujtabfe  for  this  system 
of  distributing  information. 
Many  data  bases  already 
exist  and  are  being  made 
available  to  hobbyists  with 
home  computers  via  dial- 
up  telephone  networks. 
Much  of  this  information  is 
directly  presentable  on 
teletext  systems.  There 
seems  to  be  no  lack  of 
available  material,  and 
there  are  many  organiza- 
tions willing  to  finance  its 
presentation. 

Now  that  we  have  the  in- 
formation, how  does  it  get 
from  the  source  to  your 
home?  To  begin  with,  the 
desired  page  is  composed 
within  the  display  format 
specification  previously 
highlighted  If  this  compos- 
ing is  not  done  directly  in 
the  broadcaster's  studio,  it 
probably  will  be  sent  to  him 
either  over  the  telephone 
line  or  in  the  form  of  a  digi- 
tal cassette  or  floppy  disk 
(i.e.,  in  computer-compati- 


bie  form).  At  the  station, 
this  data  is  loaded  into  a 
piece  of  apparatus  which 
encodes  it  into  a  digital 
serial  data  signal.  This  sig* 
nal  is  appropriately  filtered 
(band limited]  and  inserted 
in  unused  scan  lines  during 
the  vertical  retrace  portion 
of  the  current  video  signal 
being  broadcast.  A  decod- 
ing apparatus  connected  to 
your  TV  will  accept  this 
special  signal  and  when  the 
requested  page  is  being 
transmitted,  wilt  grab  it  and 
load  it  into  a  television  dis- 
play memory.  The  pages  are 
transmitted  row  by  row, 
one  page  after  another,  and 
then  the  whole  sequence  is 
repeated.  Hence,  if  the 
page  you  requested  had 
just  been  sent,  you  will 
have  to  wait  while  all  the 
other  pages  are  sent— until 
the  sequence  cycles  back 
to  your  page. 

Since  the  television 
broadcast  system  deals 
with  analog  and  not  digital 


photo  B.  Prestel  page.  Both  teteteKt  and  viewdata  pages  will 
look  like  this. 


signals,  special  precautions 
have  to  be  taken  with  both 
the  broadcast  and  recep- 
tion equipment.  The  digital 
signal  leaving  the  studio  en- 
counters many  places  where 
distortion  can  occur.  Some 
of  these  are  in  the  studro-to- 
transmitter  link,  the  trans- 


mitter, in  reflections  caused 

by  large  objects,  in  your  TV 
antenna  and  lead-in,  and  in 
the  television  receiver  and 
decoder  input  circuitry.  All 
these  effects  are  being  con- 
sidered by  the  organiza- 
tions trying  to  propose  stan- 
dards in  this  country. 


E^GHT  HAtfyiHG  aXkES  PECULIAR  TO  PA&E-KtHSEff 


H£AO€R 

(flow  01 


HOW  I 


ftHW  Z 


ROW  3 


iruMMK 


TrME  COOE-'MMUTCS^ 


>  r- 


TlMC  OOtlC-'HCIIJ fits' 
^ * V 


UiVlTS 


TEMS 


UMITS 


TENS 


UMITS 


TENS 


FIRTT  CHABACTEI? 
OF  PA^E-MEADEf? 


e«     Cf      C«      C«     Ct<i    Cu     C|t    Cit    Cm 


jm:[m[w]m1m'{m[p|[ 


CLOtK 
nUN-EN 


CLOCK 


FRAWINS 
CODE 


MAGAZINE   AHO 

i 


PAGE 
NUMBEJ^ 

g^irs 


PAGE 

NUMSEft 

TENS 


TIME 

'wrNUTFS' 

UNITS 


TIME 
tHINUTES 

T£HS 


TIME 

>4ouns' 

UNITS 


TIME 
TXmS 


CLOCK 


CLOCiC 

Jtum-ii* 


CODE 


y 

MfiC^Ziht   AND 
llOWr-AIWflE^S  «tOtlP 

. E 


CLOCK 
RVN-rll 


CLOCK 
RUN-iM 


rHAMIKS 
CODE 


1 

HAGA2rKE    AMD 
liOW-A0ORES5   GROUP 

i 


CLOCK 
RUW-JN 


CLOCK 


fRAMiNG 
CODE 


T 


MAGAZINE    AHOf 
ROW-flDDf?es^    GROUP 


CHARACTER 
BYTES 


|iIo|i|ohlQ|rlo[i|o|.|o|i|oh^ol olQlTf 


^ 


^  ^ 


jf  Vi. 


CLOCK  RUtl^  IM 
SEOUEMCE 


FRAUIMie 
CODE 


HAOAZINE 

•tUWBER 


Hi'  ^ 


mm  A&oMttS 


M 
P 

M 

C4 
Ci 

c* 

Cf 

c« 

Cm 

Cii 

Ci] 

Cis 

Cm 


PfiOTECTiOW    eiTS 

CONTROL   PITS 

ERASE 

NEWSFLASH 

SueTrTLE 

£UPF>RES£  HEACiER' 

UPDATE 

iMTERftUPTED  SEOUEMCE 

INHieiT  DISPLAY 

HAd'AZINC   SERIAL 

J  UNALLOCATED 


-/  V, 


STW  C  H  ROM  J  S  ATVOH 


HAGAZ4NE  AMD 

ROW  ADORE SS  GROUP 


HAMMIMG    COOES 
COMrUON   TO  AIL  ROWS 


Fig.  1  Transmission  format  for  British  teletext 


73  Magazine  •  December,  1980     121 


FtEUJ^fiLAHKINfi  INTERVAL    C£5  LlN£S)- 


i 
I 
t 
i 
I 
I 
I 
I 
I 


PQSEtBLE  TELETEXT  DATA -LINES 


I  INITIAL  )Tt*  1 
N-PATA-"*'-UIMES-ri 
t    ilNE^  [  \ 


VVimnmuiiJunTiTTThihi^^ 


1 

i  I 

I    I 

i  ' 


«22 


i  t  7      e      9     10    II      12 
I 


13     14    m    i«  'IT     ta ;  iv     2Q  ;  z^    22  \  2^ 
I  ^  "^  **    ! 


24 


110 


ih^ihihhnhhf" 

Sm     3iS     320  321     322  J£3  524    IZS  226  327    328  SlS  UO    31^      IK      1^3    534  315   ^5S 


■iHSEttttdH   TfST  SiGilAl 


Fig.  2.  Insertion  of  teletext  signal  in  625-fine  video  signal 


Teletext:  Current  Systems 
Being  (Proposed  for  North 
American  Use 

At  the  present  time,  there 
is  no  standard  for  the 
broadcast  of  teletext  in 
North  America.  In  Europe, 
there  are  systems  in  ptace 
and  regularly  broadcasting, 
with  the  largest  number  of 
receivers  in  England.  There 
currently  are  three  major 
contenders  for  teletext 
standards  in  this  part  of  the 
world:  1)  British  teletext.  2) 
French  Antiope,  and  3)  Ca- 
nadian Telidon  proposals. 
Also,  a  system  called  Cap- 
tions  for  the  Deaf  (CFD) 
should  be  mentioned  since 
it  shares  some  similar  char- 
acteristics. 

The  British  teletext  sys- 
tem is  probably  the  sim- 
plest because  it  has  a  fixed- 


transmission  format.  This  is 
likely  to  lead  to  the  cheap* 
est  decoder  design,  which  is 
important  in  the  consumer 
product  marketplace. 
There  are  two  names  by 
which  these  systems  are 
identified.  The  British 
Broadcasting  Corporation 
(BBC)  has  called  its  system 
Ceefax.  The  Independent 
Broadcasting  Authority 
(IBA)  calls  its  version 
Oracle. 

The  French  system,  An- 
tiope,  is  based  on  packets 
of  data  which  are  efficient 
representations  of  only  the 
displayed  characters  on 
any  page.  On  pages  sparse- 
ly covered,  the  Antiope  sys- 
tem requires  '  less  time  to 
transmit  than  British  tele- 
text. On  full  pages,  this  is 
not  the  case. 

The    Canadian    system, 


Photo  C.  Interested  in  a  holiday?  The  cost  of  this  page  was  .5 
pence  (about  one  cent). 


Telidon,  proposes  a  gener- 
alized technique  for  trans- 
mitting higher  resolution 
graphics  displays.  As  men- 
tioned earlier,  the  basic 
graphic  character  set  is  64 
mosaic  symbols.  Originally, 
this  was  proposed  as  a  way 
of  improving  the  appear* 
ance  of  the  primarily  text- 
oriented  displays.  However, 
as  more  experience  has 
been  gained,  the  graphics 
feature  has  been  found  to 
be  a  very  useful  and  defi- 
nitely desirable  aspect  of 
teletext. 

The  approach  suggested 
by  the  Canadians  is  to  trans- 
mit Picture  Description  In- 
structions (PDI).  These  in- 
structions describe  images 
in  terms  of  basic  geometri- 
cal shapes.  Included  are 
line,  arc,  polygon,  point, 
and  area.  To  describe  a  line, 
a  starting  point  and  a  final 
displacement  are  sent  in- 
stead of  characters  corre- 
sponding to  each  section  of 
the  line.  Decoders  could  be 
built  with  various  degrees 
of  resolution  in  the  display, 
with  higher  resolution  being 
more  costly.  Most  likely, 
these  would  have  to  be  mi- 
croprocessor based,  since 
software  algorithms  would 
be  needed  to  "draw"  the 
shapes  into  the  display 
memory.  The  minimum  de- 
coder, which  would  per- 
form similarly  to  the 
64-character  mosaic  ap- 
proach, fikely  would  be 
more  expensive  than  a  sys- 
tem which  is  tailored  only 
for  simple  graphics.  How- 
ever, the  appeal  of  high-res- 


olution graphics  is  likely  to 
influence  system  develop* 
ment  in  this  country  also. 

Captions  for  the  Deaf  is  a 
system  intended  primarily 
for  sending  captions  for 
hearing-impaired  viewers. 
As  such,  much  lower  data 
rates  are  adequate  (about 
10  times  slower).  As  one 
provision  of  the  system, 
called  info-text,  15  lines  of 
32  characters  can  be  dis- 
played. Currently,  the  FCC 
has  authorized  the  use  of 
TV  scan-tine  21  for  this  pur- 
pose All  the  teletext  sys- 
tems have  provision  for 
captioning  services,  includ- 
ing foreign  language  sub- 
titles. 

BriliSh  Teletext:  A  Detailed 
Description 

To  make  these  systems 
affordable  for  the  consum- 
er,  several    LSI    integrated 

circuits  will  be  required.  At 
the  present,  these  chips  are 
available  only  for  the  Brit- 
ish teletext  system.  Several 
manufacturers  including 
Mullard,  Texas  Instruments, 
and  General  Instruments 
offer  chip  sets  for  this  pur- 
pose. To  understand  how 
these  circuits  work,  a  de- 
scription of  the  page  en- 
coding scheme  must  be 
studied. 

The  standard  character 
set  is  shown  in  Table  1.  If 
you  are  familiar  with  ASCII 
coded  symbols,  you  will  no- 
tice  a  great  similarity  be- 
tween the  two  character 
sets.  There  are  several  char- 
acteristics which  should  be 
noticed  about  this  set.  The 
&4-character.  mosaic-graph- 
ic set  is  shown  in  columns 
2a,  3a,  6a,  and  7a,  The  digi- 
tal  code  which  represents 
these  characters  is  the  same 
as  that  for  the  symbols  in 
columns  2,  3,  6,  and  7. 

How  can  this  be?  The 
answer  is  contained  in  the 
first  two  columns  (0  and  1) 
of  control  characters.  Each 
row  of  displayed  text  is  as- 
sumed to  be  transmitted 
under  an  initial  set  of  condi- 
tions shown  in  Table  1 .  The 


i22     73  MagazinB  •  Decemtser,  1960 


"alpha''  control  characters 
tell  the  decoder  to  use  2,  3, 
6,  and  1,  or,  for  "graphics" 
characters,  to  use  2a,  3a,  6a, 
and  7a.  Therefore,  as  an  ex* 
ample,  it  is  impossible  to 
mix  lowercase  letters  and 
mosaic  graphics  without 
sending  a  control  character 
to  switch  the  character  set 
All  control  characters  are 
displayed  as  spaces. 

In  the  British  system,  24 
rows  of  text  are  transmitted 
per  page.  The  first  row  is 
special  and  is  given  the 
name  page  header.  It  in- 
cludes 32  characters  to  be 
displayed  and  special  page 
descriptors  which  are  not 
displayed.  All  other  rows 
have  40  characters.  See  Fig, 
1,  which  shows  the  makeup 
of  these  rows.  Each  row 
starts  with  a  clock  run-in 
and  framing  code  for  hard- 
ware  synchfonization.  Then 
the  magazine  (0-7)  and  row 
address  (023)  are  sent.  [The 
three-digit  page  number 
can  be  from'  0  to  799  with 
the  most  significant  digit 
being  referred  to  as  the 
magazine  number.)  Finally, 
40  characters  are  sent  The 
page-header  row  has  the 
page  number,  time  code, 
and  special  control  bits  fol- 
lowed by  32  characters.  The 
magazine,  row  address, 
page,  time  code,  and  con- 
trol bits  all  are  encoded 
with  special  protection  bits 
forming  a  Hamming  code. 
This  code  is  made  up  of 
message  and  protection  bits 
shown  in  Table  2  The  other 
characters  use  a  single  bit, 
b8,  to  form  parity .  Parity  re- 
fers to  the  number  of  bits 
which  are  equal  to  1;  in  this 
case,  an  odd  number  is  sent 
for  protection  purposes. 

From  Fig.  1,  you  will  find 
that  there  are  360  bits  (or  45 
bytes)  per  row.  All  these  bits 
[one  row)  are  transmitted 
on  one  horizontal  scan  line 
during  the  vertical  blanking 
interval.  As  shown  in  Fig.  2, 
lines  17, 18, 330,  and  331  are 
used  by  the  British  in  their 
625-line  television  system. 
Since  only  two  lines  are 
transmitted    per    field,    it 


0 


01 


1 


1 


1 


0 


0 


i 


1 


1  1 


0 


0 


0 


i 


1 


3 


1 


10 


11 


12 


13 


14 


15 


0 


0 


0 


1 


NUk® 

Alpha" 
R«d 

Alpho^ 
Gre«n 

Alpbo** 
Yailow 

Alpbo*^ 
Blue 

Alpha" 
Magenta 

Alpho" 
Cyan 


Alpho" 
Whim 


0 


Ffosh 


0 


Stecdy 


® 
End  Boil 


Stort  Box 


Normal 
Height 

Double 
Height 

Sfi® 

SI 


0 


® 


DLE 


Grophics 
Red 

Graphics 
Gfeen 

Gmphics 
fellow 

Graphics 
Blue 

Graphics 
Magenta 

Graphics 

Cyon 

Gfophrcs 
White 

Cofictal 
Display 

® 
CcHitiguous 

Graphics 

Sepamred 
Graphics 


Black® 
Background 

Bodtgroune 

Ha)d 

Graphics 

Roleas^ 
Graphics 


1 


2a 


□Id 
cdJd 
sin 

HIE] 

mis 

QjH 

qJb 

I 

BIB 

□la 

(ziIb 

t 


rr 


3   !  3a 
— I 


nil] 


liB 


n 


iIq 


IE!l 


a 


L 


13 
S 
El 

1 


E 

in 
m 


@ 


0 


B 
B 


6a 


BjQ 

lil|Q 

(Sin 

I 

E]|n 
sis 

I 

[DIB 

Qiia 
[Q|a 

IS 

is 

[2ll| 

I 


BID 
SJB 

BlB 


0 


iHJia 


!B 


[D  a 


'4^1 


a 


iia 


S^i 


01 


■ 


i 


1 


Th^#  control  characters  ore 

rtssfved  for  compotoblltty 
mm  other  ctato  codes 


Co^t  moy  be  referred 
to  by  their  column  orkd 
wm  ftg.  2/5  nfert  fQ  % 


D 


Chofocfer  rectoriglt 


TtMte  oontroi  ^wrocftri  on 
preeufTMd  b«fbr«  eoctt  row  tegine 

Table  1.  Teletext  character  codes.  Notice  the 


^QCk  ripresenti  ditpkiy  ootoor 

White  rtpriMnti  bockgrotfid  ^ 

similarity  to  ASCIi 


takes  12  fields  (6  frames)  to 
sand  a  page  of  text.  To 
transmit  360  bits,  a  rate  of 
6.9  Mbits/sec  is  used.  This 
raises  compatibility  ques- 
tions for  use  in  this  country 
where  we  have  different  TV 
standards. 

The  decoder  chip  set 
functions  in  real  time  as  the 
data  rs  received.  On  each 
line,  bit  synchronization  is 
achieved  using  the  clock 
run-in,  and  then  v^ord  syn- 
chronization is  determined 


with  the  framing  code. 
Next,  the  magazine  and  row 
address  are  grabbed  and 
Hamming  decoded.  In  the 
page  header  row,  addi- 
tional Hamming  encoded 
data  are  processed.  For  the 
character  bytes,  the  parity 
is  checked  and,  if  correct, 
the  character  bytes  are 
loaded  into  display  mem* 
ory.  During  the  display 
time,  these  characters  are 
read  out  of  memory  and. 
using  a  color-character  gen- 


erator, are  shown  on  the 
screen.  The  user  specifies 
the  desired  page  by  punch- 
ing data  into  the  chip  set  via 
a  small  hand-held  key- 
board. 

Viewdata:  Telephone 
Systems 

A  similar  service  is  possi- 
ble using  telephone  line, 
two-way  communications. 
Instead  of  serially  broad- 
casting a  fixed  set  of  pages, 
the  user  asks  for  specific 


73  Magazine  •  December,  1980    123 


Photo  D.  Visiting  New  York?  Check  out  some  options  for 
your  stay. 


pages  from   a   large   data 

base.  In  England,  there  are 
currently  over  150,000 
pages  on  their  Prestel  sys- 
tem, (See  "The  Ultimate 
Consumer  Computer/'  by 
Derfler,  Kilobaud  Micro- 
computing,  October,  1979.) 
The  main  difference  from 
teletext  is  that  only  the 
pages  you  request  are  sent. 
This  gives  apparent  im- 
mediate access  to  a  very 
large  amount  of  infor- 
mation. 

The  catch  in  using  this 
system  is  a  financial  one. 
Since  you  are  in  direct  com- 
munications with  a  com- 
puter, it  is  very  easy  to 
charge  you  for  this  informa- 
tion on  a  page-by-page 
basis.  However,  with  each 


mmmt  sits 

1 

** 

+■1 

^B        ^ 

1      "^4 

S 

^i 

Q 

Q 

0 

0 

^5 

r 

fl  ! 

0 

0       c 

3        0 

0 

I 

0 

0 

t, 

0        I 

i      1 

'0 

0 

1 

0   1 

< 

Q 

1 

1 

i 

0 

0   1 

t: 

i         i 

)     0 

p 

0 

\  ^ 

0 

k 

1 

Q 

0 

1 

J 

0 

d 

1 

1 

0 

0 

0 

0 

<J 

< 

?         1 

1 

[ 

« 

1 

1 

1 
1 

0 

0        i 

1         0 
)        0 

0 
1 

0 

1 

1 

0 

0       i 

3        i 

1 

15 

0 

1 

0 

0 

t         1 

0 

1 

1 

1 

0. 

r         ( 

9        0 

0 

0 

1 

1 

c- 

»      k 

1        0 

t 

<l 

0 

t 
1 

i:i| !  '< 

1   '      k 

r 
0 

t> 

i 
0  . 

i 

MAIililli,     „_^    :;          LS 

1        1  PROTECtlOM  tlT9 

Table  2.  Hamming  protec* 

tion    of    four-bit    binary 

val 

ues 

■ 

user  having  a  unique  access 
code,  there  are  also  advan- 
tages such  as  the  possibility 
of  having  a  complete  shop- 

from-home  service.  With  so 
many  pages  of  information, 
a  user  normally  would  refer 
to  a  guide  to  locate  pages 
of  interest,  or  it  would  be 
possible  to  step  through 
menu  pages,  narrowing  the 
topic  as  you  go.  This  is  de- 
scribed as  a  tree  searching 
method,  where  you  branch 
into  more  specific  areas. 

The  hardware  for  teletext 
and  viewdata  is  similar.  In 
fact,  viewdata  adapters  are 
based  on  teletext  systems 
with  the  addition  of  a  mi- 
croprocessor and  tele- 
phone modem.  Basically, 
this  doubles  the  cost  of  the 
integrated  circuits  (over  a 
teletext  only  system). 

Prestel:  The  British 
Viewdata  System 

In  England,  the  British 
Post  Office  controls  all 
communications  for  the 
country  This  has  helped 
considerably  in  allowing 
them  to  develop  both  tele- 
text and  viewdata  systems 
with  similar  standards. 
From  the  user's  point  of 
view,  the  text  display  looks 
identical  for  both  systems. 

The  actual  communica- 
tions is  accomplished  using 
FSK  modulation.  The  com- 
puter sends  the  characters 


at  1200  baud  (1300  Hz  for 
binary  1  and  2100  Hz  for  bi- 
nary 0).  The  user  responds 
at  75  baud  (.190  Hz  for  1 
and  450  Hz  for  0)  when  the 
keypad  is  punched. 

The  character  set  is  the 
same  as  that  previously  de- 
scribed in  Table  1,  with 
some  additional  codes. 
Some  of  these  codes  are 
cursor  controls,  page  delim- 
inators,  and  other  computer 
symbols.  Since  two-way  ir^ 
teraction  occurs  in  this  sys- 
tem, the  keypad  requires  a 
few  more  buttons  than  the 
one  solely  for  teletext  Two 
of  these  are  *  and  #,  These 
are  used  as  page  delimina- 
tors.  As  an  example,  if  page 
123  is  desired,  you  would 
enter  *123#  directly  instead 
of  continuing  with  branch- 
ing from  page  to  page. 

One  nice  feature  of  this 
system    is    the    automatic 

dialing  of  the  computer's 
telephone  number.  All  you 
need  to  do  is  push  the  view- 
data button  and  the  system 
in  the  TV  does  the  rest; 
when  the  access  procedure 
is  completed,  the  system  is 
ready  for  your  first  page  re 
quest.  Many  variations  on 
this  theme  are  possible,  in- 
cluding a  completely  auto- 
mated system  that  would 
access  data  in  the  middle  of 
the  night  when  phone  rates 
are  the  lowest  and  store  the 
information  or)  inexpensive 
audio  cassettes. 

Amateur  Radio;  Possible 
Applications 

Now  that  I  have  de- 
scribed these  consumer  sys- 
tems, you  may  be  asking 
yourself  how  to  apply  the 
technology  from  these  sys- 
tems towards  our  hobby.  In 
all  honesty,  I  don't  have  the 
answer.  Even  as  this  is  being 
written,  new  circuits  are  be- 
ing developed  which  might 
be  applicable  for  use  in  an 
amateur  radio  system. 

In  the  tradition  of  ama- 
teur radio  experimentation, 
(  expect  that  some  pioneers 
will  devise  a  way  to  send 
these  pages  of  information 


using  the  ham  bands.  A  sys- 
tem similar  to  viewdata 
could  be  envisioned,  since 
it  uses  audio  bandwidth 
channels  which  we  already 
possess.  This  might  be  im- 
plemented similarly  to  slow 
scan,  where  pages  of  infor- 
mation [and  graphics)  are 
sent  instead  of  pictures. 
Hopefully,  we  all  can  learn 
quite  a  bit  and  have  a  good 
time  doing  it 

Since  teletext  and  view- 
data are  not  yet  widely 
available  in  this  country, 
getting  information  normal* 
ly  requires  correspondence 
to  Europe  However,  there 
are  two  publications  which 
1  can  suggest  for  those  who 
are  anxious  to  learn  more. 

"Consumer  Text  Display 
Systems  (Teletext  and  View- 
data)/' IEEE  Transactions  on 
Consumer  Electronics,  July, 
1979,  volume  CE-25,  num- 
ber 3,  is  available  for  $15 
from  IEEE  Service  Center, 
445  Hoes  Lane,  Piscataway 
N|  08854,  or  from  your 
local  library.  It  is  composed 
of  two  hundred  pages  of 
general  articles  on  the 
various  systems.  For  the 
most  part,  these  are  not 
written  at  a  high  technical 
level. 

Multitext  Technical  Infor- 
mation is  available  for  $5, 
check  or  money  order,  from 
Signetics  Corp.,  Publication 
Services  — Bin  027  MTB, 
811  Arques  Ave.,  PO  Box 
409,  Sunnyvale  CA  94086,  It 
is  a  fifty-page  brochure  de- 
scribing the  Mullard  (Sig- 
netics) teletext  and  view* 
data  chip  set  and  system 
operation.  There  are  35  col- 
or photographs  including 
many  sample  text  pages, 
(Only  a  limited  quantity  of 
these  brochures  is  avail- 
able.) 

1  would  like  to  thank 
Neal  Williams  for  arranging 
the  availability  of  the  Multi- 
text  brochure  and  Merv  Cox 
for  his  photographic  work. 
Several  figures  were  ob- 
tained from  the  Broadcast 
Teletext  Specif ication,  joint- 
ly published  by  the  BBC, 
IBA,  and  BREMA.B 


124     73  Magazine  •  December;  1980 


G.I.S.M.O.  " 

2305  CHERRY  ROAD 

ROCK  HILL,  S.C.   29730 

Featuring 


ICOM 


cushcraft 


BiiM^MKDK 


^ 


Uirsen 


Wilson 


^KEIM\A/aaD 


ELECTRONICS 


DRAKE 


® 


IN  ADDITION  TO  THE  PRODUCTS  LISTED  ABOVE.  WE  ARE  ALSO  FAC- 
TORY AUTHORIZED  DEALERS  OR  DISTRIBUTORS  FOR  B  &  W,  UNI- 
VERSAL TOWERS,  BERK-TEK  CABLES,  BENCHER  PADDLES,  THE  NEW 

CES  DIALER  AND  MANY  OTHER  ACCESSORIES.  OUR  SERVICE  SHOP, 
STAFFED  BY  FIRST  PHONE,  EXTRA  CLASS  TECHNICIANS,  OFFERS 
EXPERT  SERVICE  ON  ALL  MAKES  AND  MODELS  AND  FACTORY  AU- 
THORIZED SERVICE  ON  SWAN,  YAESU  AND  KENWOOD  PRODUCTS. 


73 


THE 
.  GISMO 
'  GANG 


SERVICE  DEPARTMENT    CALL  803-366-7158 

ORDER  TOLL  FREE ! 

800*84^«6l83 


#^  Header  Servtce—  see  page  2$6 


73  Magazine  •  December,  1980     125 


Double-Duty  CW  Keyboard 

helps  you  on  receive  as  well  as  transmit 


Robert  C  Spindel  KICN 

Box  169 

North  Fatmouth  MA  02556 


Morse  code  keyboards 
are  a  popular  station 
accessory,  as  witnessed  by 
the  numerous  designs  avail- 
able.^ The  beautiful,  rhyth- 


mic sound  of  near-perfect 
CW  is  easy  to  achieve  with 
these  units.  Merely  striking 
the  keys  on  a  typewriter- 
type  keyboard  produces 
perfectly  formed  Morse 
characters. 

But  sending  flawless  CW 
is  only  half  the  battle.  You 
have  to  be  able  to  copy  it  as 
well.  And  with  the  speed  at- 
tainable   with    keyboard 


units,  that  means  copying 
at  higher  rates. 

This  keyboard  has  a 
unique  feature  to  help  you 
receive  code  accurately  so 
that  you  can  keep  up  with 
your  ability  to  send  at  high 
speeds.  With  the  flip  of  a 
switch,  the  Morse  keyboard 
becomes,  voil^,  a  tireless  in- 
structor sending  a  con- 
tinuous stream  of  random 


B  M'tra  B  a  m  d  ei 

3'  E9  U  B  'D  Q  a  'Di  m  Q  BB 
(P  0  B  U  Et*  Uh  O  B  □>  B  jrJSy 

pi  iB  IB  D  e  m  a  b  b  b  b 


Photo  A.  The  Instructor-Keyboard  is  built  in  a  homemade  case.  The  front  panel  is  made  of 
galvanized  sheet  metal  painted  with  spray  enamel.  The  keyboard  keys  have  been  re- 
labeled with  transfer  letters.  To  the  left  are  the  Instruct/Keyer  and  Space  switches;  the 
speed  control  is  in  the  upper  center;  to  the  right  are  the  Tune,  Sidetone  on-oft  and  Power 
on~off  switches. 


etters  or  five-letter  code 
groups  at  any  speed. 

The  Instructor-Keyboard 
is  also  the  perfect  device 
for  giving  new  Novices 
code  practice.  Someone 
who  does  not  know  Morse 
can  type  to  the  neophyte, 
or  he  can  use  the  Instruct 
mode  to  copy  random  let- 
ters. It  allows  practice  at 
times  when  WlAW  cannot 
be  heard  or  when  a  receiver 
is  not  available.  Since  it 
sends  letters  randomly, 
there  is  no  danger  of  the 
memorizing  of  practice  ma- 
terial which  often  limits  the 
usefulness  of  tapes  and 
records.  Needless  to  say,  its 
utility  is  not  restricted  to 
beginners,  A  little  time 
spent  copying  high-speed, 
random  code  groups  should 
have  you  copying  Wl  NJM's 
transmissions  with  ease.^ 
Switch  to  the  Keyer  mode, 
and  you  can  send  at  that 
speed,  too. 

Although  available  key- 
board designs  differ  in  de- 
tail of  execution  — some 
employ  scanned  keyboards 
while  others  use  diode  ma- 
trices, some  have  character 
buffers  and  some  have 
message  memories  — they 
all  operate  in  the  same  fun- 
damental way.  A  single 
switch  closure  is  used  to 
produce  a  logic  signal.  A 
separate  switch  is  provided 
for  each  desired  character 
[letter,    number,    punctua- 


126     73  Magazine  •  December,  1980 


tion,  or  special  symbol  such 
as  AA,  a5,  AR,  BT,  etc.),  and 
the  switches  are  arranged  in 
a  standard  typewriter  for- 
mat. The  operator  strikes  a 
series  of  keys  to  generate  a 
sequence  of  characters. 
The  resulting  logic  signal  is 
used  to  key  a  transmitter, 
FSK  converter,  sidetone  os- 
cillator, or  other  device. 
This  keyboard  uses  a  diode 
matrix  to  encode  switch 
closures  into  logic  signals, 
and  in  the  Instruct  mode  it 
uses  hard-wired  CMOS  digi- 
tal logic  elements  to  simu- 
late switch  closures  in  a  ran- 
dom manner.  Thus,  the  log- 
ic replaces  the  action  of  the 
keyboard.  In  fact,  as  will  be 
pointed  out  below,  it  is 
quite  simple  to  build  the  In- 
structor without  the  Key* 
board,  thereby  yielding  a 
simple  code-practice  ma- 
chine- 
Circuit  Features 

The  Instructor-Keyboard 
has  been  designed  without 
unnecessary  frills.  It  is  ca- 
pable of  sending  all  letters, 
digits  from  0  to  9,  common 
punctuation,  and  special 
symbols  AR,  SK.  BT,  AA, 
and  AS.  It  has  two-key  roll- 
over, which  means  that  a 
second  key  can  be  de- 
pressed while  the  first  is 
held  down  and,  provided 
the  first  is  released,  two  suc- 
cessive characters  wilt  be 
sent  with  perfect  inter-char- 
acter spacing.  Holding  a 
single  key  down  will  cause 
that  character  to  be  sent 
repetitively,  again  with  per- 
fect spacing. 

The  keyboard  is  com- 
pletely debounced  so  that 
only  a  single  character  is 
sent  when  a  key  is  struck 
even  though  the  switches 
themselves  may  bounce 
open  and  closed  for  several 
milliseconds  after  being 
struck  Furthermore,  the  In- 
structor-Key board  is  con- 
structed from  re  ad  ily*ava  li- 
able and  inexpensive  com- 
ponents. A  perusal  of  the 
back  pages  of  73  indicates 
that  the  CMOS  logic  ele- 
ments should  cost  less  than 


Photo  B.  Perfboard  and  wke-wrap  sockets  are  used  for  the  two  electronic  boards.  The  diode 
matrix  and  keyer  are  on  the  lower  board.  The  Instructor  electronics  are  on  the  snnallef  board 
on  the  left,  partially  obscuring  the  diode  matrix. 


$15  to  $20  Keyboards  are 
available  from  a  number  of 
surplus  dealers  at  reason- 
able  cost. 

The  digital  logic  for  both 
Keyboard  and  Instructor  is 
all  CMOS,  selected  for  its 
tolerance  to  power-supply 
variations  and  its  high  im* 
munity  to  electronic  noise* 
I  have  not  observed  any  rf 
interference  with  the  opera- 
tion of  the  Keyboard  even 
in  the  presence  of  my  VkW 
linear  amplifier. 

There  are  three  main  sub- 
sections in  the  Instructor- 
Keyboard.  The  first  is  a 
diode  matrix  for  encoding  a 
switch  closure  into  a 
unique  digital  signal  repre* 
sentative  of  the  desired 
character.  This  is  fed  to  the 
second  subsection,  the 
digital  keyer  logic,  that  con- 
verts it  into  appropriate 
dots  and  dashes.  The  third 
subsection  is  the  Instructor 
itself.  It  automatically  gen- 
erates digital  signals  iden* 
tical  to  those  created  by 
switch  closures  so  that  let- 
ters are  sent  without  strik- 
ing keys.  They  are  also  sent 
Without  the  need  for  a 
diode  matrix  so  that  an  In- 


structor can  be  built  with- 
out the  keyboard-matrix 
combination.  By  the  same 
token,  the  unit  can  be  con- 
structed without  the  In- 
structor electronics  and 
used  as  a  conventional  key- 
board. 

In  the  Instruct  mode, 
three  spacing  options  are 
provided.  The  Instructor- 
Keyboard  can  be  set  to  is- 
sue a  continuous  stream  of 
random  letters  with  the 
proper  three-element  inter- 
character  spacing.  Alter* 
natively,  random  five-letter 
code  groups  can  be  sent 
with  either  a  long  or  short 
pause  between  groups.  Let- 
ter  spacing  within  groups  is 
always  precisely  correct  for 
the  speed  being  sent. 

As  described  below,  the 
Instructor  sends  only  let- 
ters. It  was  felt  that  sending 
letters  only  provided  a  cost- 
effective  realization  of  an 
automatic  Morse  code  gen- 
erator easily  adaptable  to 
many  existing  keyboards. 
The  unit  can  be  altered  to 
allow  automatic  generation 
of  numbers  and  punctua- 
tion in  the  Instruct  mode  at 
the  expense  of  an  increased 


parts  count 

The  Diode  Matrix 

All  characters  are  encod- 
ed into  an  eight-bit  digital 
word  by  the  diode  matrix. 
The  coding  scheme  is  the 
same  as  that  used  by 
Bryant  W4UX  and  Horowitz 
W1 HFA.  A  diode  is  used  for 
each  dash,  no  diode  for  a 
dot,  and  a  final  diode  to  sig- 
nify the  end  of  the  charac- 
ter. Diodes  are  used  for 
dashes  because  there  are 
fewer  dashes  than  dots  in 
Morse  code,  thus  reducing 
the  number  of  diodes  need- 
ed. The  first  few  letters  and 
numbers  are  wired  as 
shown  in  Fig.  1 .  The  remain- 
ing pattern  of  diodes  should 
be  obvious  if  it  is  kept  in 
mind  that  a  diode  is  wired 
in  place  for  a  dash  and  also 
to  terminate  the  character. 

The  bits  in  the  code  word 
are  labeled  B1  through  BS. 
Note  that  with  no  keys  de- 
pressed, alt  bit  lines  are 
held  high  {  +  12  volts)  by  a 
single  10k  pull-up  resistor  on 
each  bit  line.  Depressing  a 
key  (closing  a  switch)  caus- 
es only  those  bit  lines  con- 
nected to  the  switch  by  di- 


73  Magazine  •  December,  1980     127 


4 


\ 


10  K 


4CI 


lOK 


^^L.._j*^_yL..^; 


10  K 


lOK 


■2 

7 


7 


^L 


^L-^^f!^l.. 


■■■^_^L__  /  / 


..-.^ 


\ 


n; 


^; 


-*BI 


■*B2 


A 


as 


-*a4 


—  B5 


2?L.. 


B€ 


I  OK 


A 


■*BT 


lOK 


^■^A^- 


■^BS 


Fig.  1,  Wiring  diagram  for  diode  matrix.  At!  diodes  are 
genera /-purpose  switching  diodes  such  as  1N914s.  tf  con- 
structed as  an  Instructor  onlyr  diodes  are  not  needed,  but 
the  10k  pull-up  resistors  should  be  connected  to  alt  bit 
lines. 


odes  to  be  forced  to  ground 
(0  volts).  Thus,  the  pattern 
of  bits  appearing  on  B1 
through  B8  for  the  letter  A 
will  be  10011111  where  we 
have  used  a  1  to  denote  a 
high  voltage  level  and  a 
0  to  denote  a  low,  or  zero, 
leveL  Depressing  the  B 
key  will  create  the  pattern 
01110111,  and  a  question 
mark  will  be  11001101. 
These  are  the  unique  digital 
codes  that  the  keyer  por- 
tion of  the  unit  translates  in- 
to appropriate  dots  and 
dashes.  Incidentally,  these 
are  the  codes  that  the  In- 
structor portion  of  the  unit 
also  must  simulate. 

The  Keyer 

The  heart  of  the  keyer 
consists  of  an  8-bit  parallel- 
to-serial  (P/S)  shift  register, 
IC9,  dot-dash  generator  flip- 
ffops  lC7a  and  IC7b,  and  an 
end-of-character  recogniz- 
er, IC6.  Additional  logic  is 
used  to  debounce  the  key- 
board and  to  insert  a  proper 
space  between  characters. 
This  space  is  exactly  three 
code  elements  long  (a  dot  is 
two  elements  long)  as  re- 
quired in  Morse  code.  A 
dash  is  four  elements  long 
(three  on  and  one  off).  Inter- 
word spacing  is  seven  ele- 
ments in  length. 


Detailed  operation  of  the 
keyer  logic  can  be  deduced 
from  one  of  the  excellent 
manufacturer's  data  books 
on  CMOS  logic.  The  follow- 
ing is  a  brief  explanation  of 
the  general  sequence  of 
events  that  occurs  after  a 
key  is  closed. 

The  bit  pattern,  or  code 
produced  by  the  diode 
matrix,  is  inverted  by  IC5 
and  part  of  IC1  so  that  the 
letter  A  becomes,  for  exam- 
ple, 01100000.  The  shift 
register  accepts  this  code 
on  its  8  input  lines  and  im- 
mediately transfers  it  to  its 
output  lines  if  the  P/S  line  is 
high  and  if  the  A  Enable 
{AE]  line  is  high.  When  AE  is 
low,  the  input  lines  are  dis- 
abled and  information  pres- 
ent on  them  is  ignored.  This 
feature  is  used  to  debounce 
the  keyboard  Now,  when 
the  P/S  line  is  low,  input 
data  is  ignored  similarly, 
but  the  register  is  converted 
to  its  serial  mode,  Data 
stored  in  the  register  then 
can  be  clocked  out  by  puls- 
es applied  to  the  CLK  input. 

Each  positive  transition 
of  the  clock  signal  transfers 
the  bit  pattern  one  step 
through  the  register.  Bits  at 
the  top  (IC9-1)  "fall  out" 
while  the  empty  spaces  at 
the  bottom  of  the  register 


are  filled  with  whatever 
signal  is  present  on  the 
serial-input  (SI)  line.  Since 
this  pin  is  grounded,  as  the 
bits  are  shifted  through  the 
register  they  are  replaced 
by  zeros  at  the  bottom.  The 
bit  present  on  IC9-1  turns 
the  dash  flip-flop  on  and  off 
depending  on  whether  it  is 
high  or  low,  respectively. 
Meanwhile,  IC6  constantly 
monitors  the  status  of  the 
output  lines  of  the  register 
in  order  to  detect  an  end-of- 
character  condition.  When 
an  end-of-character  occurs, 
the  lines  monitored  by  IC6 
are  all  low,  its  output  goes 
high,  thus  terminating  key- 
board output  through  IC1 
and  IC3b,  At  this  time,  IC9-1 
will  be  high  since  a  diode 
has  been  i  nserted  at  the  end 
of  each  character.  One 
more  clock  cycle  makes 
this  low  and  lC3a  turns  the 
shift  register  back  into  its 
parallel  mode  allowing  it  to 
accept  a  new  code  word, 
the  next  character.  This  ex- 
tra clock  cycle  ensures  that 
there  will  be  a  three-ele- 
ment space  between  suc- 
cessive characters. 

Note  that  in  its  idle  state 
the  keyer  logic  has  the  code 
word  00000000  on  the  out- 
put tines  of  IC9.  The  inputs 
to  IC6  are  low;  its  output  is 
therefore  high.  Upon  strike 
ing  a  key,  at  least  one  of  the 
bits  at  the  output  of  IC9 
goes  high  so  that  the  output 
of  IC6  goes  immediately 
low.  This  triggers  the  one- 
shot,  1C4,  and  it  responds 
with  a  2-ms  pulse  which  is 
applied  to  the  AE  input  of 
IC9.  It  has  the  effect  of 
disabling  the  input  lines  of 
the  register  for  sufficient 
time  to  allow  all  contact 
bounce  to  subside. 

The  keyer  clock  is  a  sim- 
ple oscillator  made  of  two 
CMOS  inverters.  With  the 
parts  values  shown,  the 
speed  is  adjustable  from 
about  5  to  50  wpm.  Varia- 
tion of  speed  in  either  direc- 
tion can  be  achieved  by 
changing  the  value  of  the 
10k  resistor  or  the  1-uF 
capacitor.    The    sidetone 


oscillator  also  is  con- 
structed with  two  inverters, 
and  gives  an  approximate 
700-Hz  tone.  The  output  of 
the  sidetone  oscillator  is 
gated  on  and  off  by  the 
keyer  through  lC3c  and  is 
then  applied  to  Q1.  Q2 
drives  a  small  relay  to  key  a 
transmitter.  SI  closes  the 
relay  for  tune-up  purposes. 
If  desired,  a  solid-state  key- 
ing circuit  can  be  substi- 
tuted for  the  relay;  a  reed 
relay,  however,  is  fast 
enough  to  follow  60-wpm 
keying  and  allows  the  key- 
board to  be  used  with  vir- 
tually any  transmitter.  To 
prevent  relay  sticking  with 
those  transmitter  keying  cir- 
cuits that  draw  more  than  a 
few  milliamps,  it  often  is  a 
good  idea  to  place  a  20-  to 
50-Ohm  resistor  in  series 
with  the  output  line. 

The  Instructor 

A  careful  examination  of 
the  digital  code  words  pro- 
duced by  the  diode  matrix 
for  the  26  letters  of  the  al- 
phabet indicates  that  they 
use  only  bits  B1  through  B5. 
These  five  bits  allow  32 
combinations  of  zeros  and 
ones.  Now,  a  five-bit  binary 
counter  will  count  sequen- 
tially from  0  to  31  and  in  the 
course  of  doing  so  will  pre- 
sent at  its  output  every  one 
of  the  32  possible  bit  com- 
binations. If  we  devise  cir- 
cuitry to  select  only  the  26 
output  states  correspond- 
ing to  the  letter  codes,  and 
then  apply  the  output  of 
the  counter  to  the  B1 
through  85  input  lines  of 
the  keyer,  the  counter  will 
effectively  act  as  a  substi- 
tute for  the  keyboard  and 
diode  matrix.  If  the  counter 
is  clocked  slowly,  the  keyer 
will  generate  a  sequence  of 
letters  corresponding  to  the 
bit  codes  at  the  output  of 
the  counter  and  will  repeat 
this  sequence  ad  infinitum. 

In  order  to  generate  let- 
ters in  a  random  sequence 
with  no  repetitions,  binary 
counter  1C9  is  clocked  at  a 
frequency  that  is  high  com- 
pared   to    keying    speeds. 


12B     73  Magazine  •  December,  1980 


i£V 


+  I2V 


♦I2W 


fit   • 


B2 


as 


le 


u 


14  •- 


I'^tpS — IS 


w 


21 


IW 


23 


n 


U 


i* 


a 


m     p/s 


IC9 
40^4 


SI 


CLK 


ID 


13 


C*iARAC7£ff 


15 


It 


ICI 


11 < 


ICIP 


ICIO 


47  tt 


i^" 


SOK 


♦^ — ^ 


ipF; 


P 


SFECO 


1. 


10 


IJ 


11 


J  0 

iCTp 
40SrT 


U 


u 


i?07 


1CI«S.I0  «04f  HEX  IHVCHTtfl 

le?  4071  SMMFyT  mofl 

ICJ  40 ■  J    2-tl«PUt   AMD 

IC4  4047  0ME-5M0T 

ICfi  4074    &- IN  PUT   NOR 

tCT  4027  DUAL  J-K  FLlP-FLOf" 

ice  40tl     DtlAL  P  FLtP-FLOP 

leS  4054    B-B(T  P/S   SHIFT 
REGtSTEn 


4QI3 


J* 


♦izy 


*  T*  h* 


1^4 
404T 


11 


o^mttf 


SiO£rD^t£ 


^oi^f  j; 


22  K 


♦av 


*— • — 


1. 


5 

n 


bZEI^ 


J  g 

4027 


&*St* 


iL 
:4 


*I2V 


ICI 


-7g> 


^jbji- 


01 


fv"OLUW£ [  I ^^ 


IZV 
A- 


47 


C:500       pC( 


t  ftELAT 


1 


S2 


roftfE 


lOK 


„    ^ 


/Tf 


QZ 


1 

vs. 


TUNE 


X 

I 


OUT 


OOI^F 


♦12  V 


t-^i|ci>— 


t I 


m 


ICZC 


>- 


X 


UNUSED 


I u 


*»«        .  ICIO 

t_  i 


ICIO  4       ^j 


Fi%  2.  The  keyer  subsection  uses  CMOS  integrated  circuits.  All  unused  CMOS  gate  inputs  are  tied  to  12  volts  as  recom- 
mended  by  the  manufacturer.  Q7  and  Q2  are  general-purpose  transistors^  and  many  substitutions  will  work. 


NOR  gates  IC6a  and  IC6b 
are  wired  as  inverters  to 
form  a  CMOS  oscillator 
running  at  about  700  Hz  (60 
wpm  corresponds  to  about 
25  Hz).  Thus,  a  new  bit  code 
appears  at  the  output  of  the 
counter  every  1/700  of  a 
second. 

The  keyer  logic  responds 
to  whatever  code  is  pre- 
sented to  it*  generates  the 
appropriate  tetter,  and  re- 
turns to  its  ready  state.  Be- 
cause the  generation  of  the 
letter  is  slow  compared 
with  the  speed  of  the  count- 
er, the  counter  has  counted 
from  0  to  31  many  times 
during  the  time  it  takes  for  a 
letter  to  emanate  from  the 
keyer.  The  code  present  at 
the  input  of  the  keyer  upon 
comptetion  of  the  letter 
will  therefore  be  a  function 
of  the  letter  length,  the  fre- 
quency of  the  counter  oscil- 


lator, and  the  frequency  of 
the  keyer  oscillator.  Since 
these  are  unrelated  quan- 
tities, the  bit  code  present 
at  the  counter  output  when 
the  keyer  is  ready  to  gener- 
ate a  new  letter  will  be  in- 
dependent of  the  bit  code 
of  the  previously  generated 
letter  Thus,  random  letters 
are  generated. 

Only  26  of  the  32  possi- 
ble counter  states  represent 
valid  letters  Rather  than 
detect  these  26  states,  we 
detect  only  the  6  states  that 
are  invalid  and  disable  the 
Instructor  output  if  one  of 
these  should  occur.  In  fact, 
we  need  detect  only  5  il- 
legal states  since  the  state 
11111  corresponds  to  the 
condition  of  the  keyer  with 
no  keys  depressed  and  no 
output  will  ensue.  Logic 
gates  IC2,  IC3,  IC4,  and 
ICI  a  and  ICIb  comprise  the 


unwanted-state  detector. 
The  output  of  IC2d  goes 
high  whenever  one  of  the 
forbidden  states  occurs. 
This  high  is  passed  through 
IC6a  and  IC6b  and  holds 
the  register,  composed  of 
D'type  flip-flops  IC10A, 
IC11,  and  ICI  2,  in  a  set 
mode.  That  is,  the  output 
lines  of  the  register  are  held 
high  (111111  which  is  equiv- 
alent to  having  no  keys 
depressed.  No  letter  is  gen- 
erated For  all  other  combi- 
nations of  B1  through  B5,  a 
letter  is  sent.  There  is  no  ap- 
parent pause  in  the  output 
of  the  Instructor  since  new 
combinations  of  bits  are 
created  every  1/700  second. 
Switch  SI  in  Fig.  3  allows 
the  Instructor  to  be  turned 
off  by  holding  the  register 
in  a  continuously  high,  or 
set,  mode.  The  keyer  may 
then   be  activated  by  the 


keyboard  and  diode  matrix. 
When  SI  is  grounded,  the 
Instructor  sends  random 
letters  in  a  continuous  se- 
quence. In  its  middle  posi- 
tion, 51  is  connected  to  the 
output  of  one-shot  IC7.  ICfl 
is  wired  as  a  four-bit  count- 
er that  is  clocked  by  the  P/S 
line  of  the  keyer.  Since  the 
P/S  line  goes  from  low  to 
high  after  the  generation  of 
each  letter,  IC8  is  clocked 
one  count.  When  four  let- 
ters are  counted,  the  one- 
shot  is  triggered  and  its  out- 
put goes  high  for  a  period  of 
time  determined  by  Rl.  R2, 
and  CI,  This  high  disables 
the  D  flip-flop  register  by 
setting  it,  The  fifth  letter  is 
completed,  but  a  new  one  is 
not  generated  until  IC7 
goes  low.  This  period  of  si- 
lence can  be  made  long, 
short,  or  nonexistent  de- 
pending upon  the  position 


73  Maganne  •  December,  1980     129 


1^1 


9 


■2K 


+  I2V 


IC6c 


EOK 


4Cl^a 


/?r 


11 


ICl2b 


r 


13 


B4 


B5 


2K 


I 


2K 


2K 


:£K 


+  I2V 


iCHa 


9 

r ^ 


m 


OSCILLATOR 


11 


I  CI  lb- 


J' 


13 


$       [$ 


I 


ICiOd 


1 


U 


Cl      Q2      03       Q4 


OS 


^^^O-il-F 


01  y 


(J2> 


TO     , 

kC9  < 


Q3> 


04> 


05r> 


Lb. 
[/I 


a. 
ZJ 


10 


a 


m 


COUMTERJ 


16 


IC^O 


3        S 


Q3> — m— y 


ILLEG^^L  WORD   DETECTOR 


O 


a 

z 

4 

z 


S ,_ 


ICI  4061     ?-|ftlPUT    AND 

JCZ  40TI     ^-JNPUT      OR 

tC3,4     4073    3-1NPU7     AND 

PCS         404$    HEX  INVERTER 

IC€         400E     E-INPUT   MOR 

fCT         4047    ONE    SHOT 

ICS.$     45Z0     DUAL  4- BIT   BINAt^y 

COUMTEfl 
ICFOJIJ^    40H   DUAL   D  FLIP- FLOP 


Q*>- 
02  >- 


+  IEV 


Q2> 
03  > 
Q5>- 

Ql> 
,Q4> 


.10      ^1 ^ 


IC6o 


1&      I? 


REGISTER 


'l^v 


*isv 


TO   IC9-^3 

(P/S  JNPLITJ     »— ♦ 

OF    FIG  4 


+  f^V 


*i2V 


n 


*\2V 


I?    u  /^ 


re  106 


13  fl 


»cs 


lCi4      J 


16 


7      15 


JiZlii. 


SF 


■ISV 


Jf 


Ki7 


/7? 


ID 


cor+Ti*JUOUS' 

5  LETTER 

GflOUP$-OFf 


il^F        I 


li 


f330 


[short  M^QNG  1 

Jim 


LETTER  CQONTEft  | 


Fig.  3.  The  electronics  of  the  Instructor.  Not  all  connections  are  shown  to  avoid  confusion  in  the  diagram.  All  points  la- 
beled Q1  to  Q5  are  connected  together.  Similarly,  all  those  labeled  Q1  to  Q5  are  connected  together.  All  unused  CMOS 
gates  are  tied  to  12  volts. 


D\0DE5 
SOPIV 
/E  A 


MCTei2 


+J2V 


m 


! 


£&V 


Fig,  4.  The  power  supply  is  not  critical,  and  any  voltage 
from  5  to  12  will  work. 


of  S2. 

Construction 

Parts  placement  and 
inter-component  wiring  are 
not  at  all  critical.  I  prefer  to 
use  wire-wrap  techniques 
for  digital  logic  circuits  be- 
cause it  is  fast  and  reliable. 
All  the  wiring  can  be  com- 
pleted in  an  evening  or  two. 
Care  should  be  exercised  in 
construction  of  the  diode 
matrix,  if  it  is  included. 
With  so  many  diodes,  it  is 


easy  to  make  an  error.  How- 
ever, troubleshooting,  if  re- 
quired, can  be  accom- 
plished with  simple  equip- 
ment. A  voltmeter  will  in- 
dicate high  or  low  states  or 
an  LED  driven  by  a  transis- 
tor  will  serve  the  same  pur- 
pose. One  of  these  simple 
tools  will  allow  diagnosis  of 
almost  any  possible  prob- 
lem. 

The  power  supply  is  not 
critical.  I  chose  to  use  a 
12-volt  regulator  (Fig.  4),  but 


anything  from  5  to  12  volts 
will  work  and  regulation  is 
not  necessary.  It  is  a  good 
idea,  though,  to  filter  the 
power  supply  adequately. 
Oscillators  like  the  keyer 
clock  have  a  tendency  to 
synchronize  with  power 
supply  ripple.  If  this  occurs, 
speeds  will  appear  to  jump 
from  one  to  another  as  the 
speed  control  is  rotated, 
rather  than  to  vary  smooth- 

ly. 

Variations 

The  Instructor  portion  of 
the  circuitry  can  be  used  as 
is  with  many  existing  key- 
boards, and  can  be  adapted 
simply  for  use  with  others. 
If  the  coding  scheme  in 
your  keyboard  uses  diodes 
for  dashes  and  character 
termination  and  operates 
from  5  to  12  volts,  just  con- 


nect the  Instructor  directly 
to  it.  If  you  can  identify  a 
portion  of  your  keyboard 
logic  that  produces  a  tow- 
to-high  transition  after  each 
letter,  connect  it  to  1C8-1.  If 
you  cannot  find  such  a 
point,  leave  out  1C7,  IC8, 
and  ICIOb.  Then  switch  SI 
to  ground  for  continuous 
letter  generation  or  to  12 
volts  for  resumption  of  nor- 
ma] keyboard  operation. 

With  keyboards  that  use 
other  coding  schemes,  the 
illegal-logic-state  detector 
must  be  modified.  This 
should  not  prove  to  be  dif- 
ficult once  it  is  understood 
exactly  how  the  detector 
works.  If,  for  example,  your 
existing  keyboard  uses  di- 
odes for  dots  instead  of 
dashes,  _s[mply  reverse  all 
Ql  to  Q5  and  Q1  to  Q5 
leads.      Other      coding 


130     TQMagazme  •  December,  1980 


schemes  will  require  similar 
simple  changes. 

As  mentioned  above,  the 

Instructor-Keyboard  also 
can  be  constructed  without 
the  keyboard  or  diode  ma- 
trix and  used  as  an  Instruc- 
tor alone.  Simply  construct 
keyer  and  instructor  elec- 
tronics as  shown  in  the  fig- 
ures and  attach  10k  pull-up 
resistors  to  lines  Bl  to  B8  of 
Fig.  2. 

Numbers  and  punctua- 
tion can  be  added  to  the  In- 
structor's vocabulary,  if  de- 
sired. However,  this  will  re- 
quire the  addition  of  exten- 
sive detection  circuitry  to 
eliminate  unwanted  codes. 
tn  order  to  accommodate 
these  additional  characters, 
3  total  of  8  bits  in  a  code 
word  is  needed.  There  are 
256  combinations  of  zeros 
and  ones  in  an  8-bit  word, 
but  the  Instructor  uses  only 
a  small  number  of  them. 
Thirty-six  are  needed  for  let- 
ters and  numbers.  Adding  a 
comma,  question  mark,  and 


period  gives  39;  special 
symbols  will  add  a  few 
more.  In  this  case,  we 
would  have  to  detect  21 7  il- 
legal words  [ignoring  spe- 
cial symbols  which  are  not 
really  needed  for  practice) 
It  would  undoubtedly  be 
easier  to  detect  the  39  legal 
ones,  allow  them  to  be 
passed  through  the  register 
to  the  keyer,  and  reject  all 
the  rest.  To  do  this,  one  sim- 
ply would  invert  the  output 
of  the  detector  logic  at 
lC6b  IC9  would  have  to  be 
wired  as  a  full  8-bit  counter 
and  two  more  D  flip-flops 
would  have  to  be  added  to 
the  register.  ■ 

References 

1.  Bryant,  Touchcoder  11/*  QST, 
July,  1969;  Horowitz,  "Compu- 
codef."  QST,  June,  1975;  Crom, 
"This  Station  Plays  Beautiful 
CW,"  73,  March,  1979;  Helfrick, 
"An  (nexpensive  Morse  Key- 
board/' QST,  January,  1978. 
These  articles  contain  addition- 
al references. 

2.  Hart,  "High  Speed  CW,  Any- 
one?" QST,  June,  1979. 


i 


Reach  Out! 

just  like  adding  a  10-watt  amp 
to  your  2-meter  hand-held... 


True  %  wave  gain  antenna 

Dramatically  boosts  reception  as  wen 
as  transmit  range 

Indtvidually  tuned  matching  network 

Base  spring/tuned  coil  protects  radio  as 
well  as  antenna  from  accidents 

Extends  to  47",  telescopes  to  only  8" 

BNC  connector  fits  most  current  hand- 
held and  portable  radios 

Better  than  1.5:1  VSWR  across  the 
entire  144-148  MHz  band 

Only  $24,95  from  your  dealer  or 
postpaid  from  VoCom 

(lllmots  fesidenis  p^a&e  incitjde  G%  saies  tax) 
Mwt  4&oef  mtr  IS,  50  ani  10Q  watt  ampffffffrs  hr  hmd-hefds 


VoCom 


*^90 


PRODUCTS 

65  E.  Palatine  Rd..  Suite  111 

Prospect  Heights,  tL  60070 

(312)  459-3680 

Dealer  Inquiries  Invited 


t 


Hustler  fixed  station  two  meter  gain  antennas. 


Hustler  is  the  choice  of  those  who  know 
quality,  Because  we're  known  for  precision 
engineering  and  electronic  expertise. 

Only  the  finest  materials  are  used 
to  make  a  Hustler  amateur 
antenna.  And  each  model  is  the 
result  of  years  of  design  excellence. 

From  easy  and  precise  assembly 
to  outstanding  long-range  trans- 
mitting and  receiving,  Hustler 
quality  speaks  for  itself.  See  your 
dealer  and  find  out  why! 


2-MB  5 


^w 


EH 


mc 


*^3G5 


3275  North  B.  Ave.,  Kissimmee,  Florida  32741 


CleaTfy  the  choice  of 
those  who  know  Quatity. 


2-MB  11 


^  Reade/  Stffvice — seff  page  22*6 


73  Magazine  •  December,  1980     131 


Sixteen  Channels  of  Digital  Delight 


do-it-yourself  data  acquisition 


COUNTER-COMPARATOR  A/O 


'J. 


1  1  "^B 


Cut  RATf 


START  CONVift 


mmtaammsa 


Photo  A.  A  good,  low-cost  S-bit  AID  made  by  Datel.  !ts  output  coding  is  in  binary,  it  runs  off 
5  volts,  and  it  has  a  conversion  time  of  only  500  ^,  Its  current  selling  price  is  about  $8,00. 
(Photo  courtesy  of  Datel) 


r 


IWPUTS    i 


MULTlPLEXEft 
INI 

tm 

IHft 

tut 


OUT 


AMALOG 
IMPUTS    1 
(■-IS) 


1 


CHIT 


1114 

tut 
t«f 


MUtTtPLEKEfl 


TO  ^(^OCESSaR  Oft 
■«  AN  ''ENABLED" 

VOLTAS£   CONDITION 


INIT lATt 
CQMVrRSICM 


4NAL00  A/D 

IN  CONV£f»TEI» 


DATl  yALi& 


I   OIGITAL 
^  OUTPUT 


TOPRf^CESSOfl  OR 
«"STf?OdrOFAN 
a-frit  LATCH 


Fig.  1,  A  block  diagram  of  a  complete  16-channel  DAS  that  you  can  build  with  almost  any 
A/D  convener  on  the  market  today. 

\^  132     73  Magazine  •  December,  1980 


Chrh  Bowkk  WBAUHY 
1498  Hoifand  Street 
Mdboufm  ft  3293S 


In  my  last  article  on  A/D 
conversion  (November, 
1980),  I  covered  some 
theory  to  help  you  under- 
stand the  principles.  Now 
we'll  put  that  knowledge  to 
work  and  build  a  complete 
16-channel  Data  Acquisi- 
tion System  (DAS  — a 
16-channel  A/D  converter]. 

Background 

A  portion  of  my  last  arti- 
cle deal t  with  the  process  of 
choosing  the  right  A/D  for  a 
specific  function.  The  gist 
of  that  section  was  that 
there  are  literally  hundreds 
of  A/D  converters  on  the 
market  today,  and  choosing 
the  right  one  for  your  needs 
could  be  quite  a  difficult 
process  if  you  don't  know 
what  to  look  for.  The 
average  hobbyist  just  does 
not  need  extreme  accuracy 
or  extremely  fast  conver- 
sion times.  He  is  looking  for 
an  A/D  which;  (1)  runs  on 
common  supply  voltages. 
(2)  covers  the  needed  ana- 
log input  range,  and  (3)  has 
a  digital  output  which  is 
compatible  with  his  inter- 
face circuitry. 

There  are  quite  a  few 
low-cost  A/D  converters  on 
the  market  which  should 
satisfy  most  any  hobbyist 
{see  Photos  A  and  B},  But 


the  purpose  of  this  article  is 
to  show  you  how  you  can 
use  that  A/D  to  build  a  com- 
plete 16^channel  DAS, 

What  is  a  DAS? 

We  know  from  my  pre- 
vious article  that  an  A/D 
takes  a  single  analog  volt- 
age and  converts  it  to  digi- 
tal form.  There  are  a  tot  of 
different  conversion  pro- 
cesses possible  and  a  few 
different  digital-coding 
techniques  utilized  in  var- 
ious A/D  converters,  but  the 
end  result  is  always  the 
same  — some  kind  of  digital 
word  representing  the  ana- 
log voltage  level  present  at 
the  A/D's  input.  This  is  just 
fine,  but  what  if  there  were 
several  different  analog 
voltages  which  we  wanted 
to  digitize?  Of  course,  if  we 
had  16  different  analog 
voltage  levels  to  measure, 
we  could  go  out  and  buy  16 
A/D    converters    and    wire 


Photo  B.  Another  Datef  device  which  is  a  bit  more  expensive  ($34,001  'f  '^  a  12-bit  binary 
or  3Vz'digit  BCD  coded  A/D  convener,  and  it  runs  off  ±5  volts  and  has  a  lO-ms  conver- 
sion time.  (Photo  courtesy  of  Datel) 


PfN  NUMBERS 


REAR  €Qftf\ilC  riffl 


4NAL0a 

I h Puts 


14 


ir 


M 


tli  * 


V?        14 


15  * 


WS         »* 


If  * 


V4 


II 


13  fr 


V& 


m  «- 


V6 


n  *- 


vr 


V,  H» 


vf 


16 


^DB 


40S1 


out 


'B5 


•3 
1H 


^ 


TE 


^t.#- 


AHJlLQfi 


i«* 


-aw 


Zl  e- 


-tV      ^'iEF 


4-i 


m 


C3 


^5^l<■ 


iMifiAn:  t&Mv 


•9 


♦a 


14 


zropF 


4 


*■ 


IQ 


r 


■  * 


7  » 


S  • 


«* 


V9 

41 

vio 

14 

VII 

»% 

VIJ 

12- 

4  • 


vra 


¥:* 


3  * 


VII 


z.  »- 


VQ 


9 


e  CHANNEL 


ifl* 


TC^ 


R6 


/^ 


«9 
20K 


^ 
I 

4r 


tw 


♦  T 


na 
tow 


i^iJCl 


C4 
J 


SCALE 
ADJUST 


r 


RfO 
24IK 


J) 


_i_C5 


14 


V 


aa 


liH 


tC3 

TELEOrNE 
S700 
EEF?IES    A/D 


QNH 


OFFSET 
4DJUST 


I 


91JI& 


'55 


IflEF 


?■*   fWlftLJL/lOOO 


«    tr      1 


>2 


Brt  0 


II 


■o 


-w  1 


-fl  i 


-"* 


CrrtiitAL 


«?      ^(iATA 


■«■ 


» 


(0 


lO 


-•» 


1 1 


«f 


2f 


Bust 


-•la 


J 


1^1,       OATi   VALH3 


X 


5V 


14 


voo 


iC4 
4024 


CLH 


OT  q«   fl*  ^   OS  02    Qi 


f/4 
4^11 


1,2 


ITT 


OUTPUTS 


If 


B 


Bva 


-^tj 


-•It 


b  ( OUTPUTS 


■«2I 


-o  J? 


/w 


ur 


J 


1 

■■JV 


111  0«LT  0«(i  itBO  ADitUSt    C0nt»QL   1%  mOWHfitl.    FOft   £   llVPllTS  USE  Tt^E    553K 

R€st$rm  Jifto  ipo«  Por£*iTt0MET£ft,  Gnoi/Na  pw  i6  *iiio  oeuete  the  w,  ioo*  *no 

£OK  COKFaNemTS.  when  measuring  ONI^T  positive   voltages  DCLEfE    tHC   95:il( 
ntflSTOft  AttiD  THE   toon  POTENTtOUEtef*. 

\Z\   FOR  AN   EIGHT  CHANNEL  CATA   ACQUISITION   5YSTEW  GROLJND  THtS   PQIM    AND  DELETE 
\CZ    AMD    IC5, 


F/g,  2.  The  complete  schematic  for  the  16-channel  DAS  utilizing  the  Teledyne  8700  series  of  A/D  converters. 

73  Magazine  *  Oecember,  19&0    133  JB 


Photo  C  This  h  what  the  big  boys  use  for  a  16<h3nnd  Data  Acquisition  System.  The 
MP6812  can  be  bad  for  a  mere  $200.00.  (Photo  courtesy  of  Analogic) 


them  up  in  a  maze  of  confu- 
sion. But  if  you're  anything 
like  me,  you  don't  have  the 
time  or  the  money  to  throw 
away  on  such  a  huge  proj- 
ect. You  could,  however 
(with  a  minimum  of  time, 
effort,  and  money),  build 
the    complete   16-channei 


DAS  described  in  this  arti- 
cle. 

Fig.  1  is  a  block  diagram 
of  one  possible  candidate 
for  a  complete  DAS.  Basic- 
ally, all  we  need  to  add  to 
our  A/D  is  a  counter,  two 
8-channel  multiplexers,  and 
possibly   some   chip-select 


circuitry    for    the    analog 

multiplexers  With  the  addi- 
tion of  this  minimal  amount 
of  ctrcuttry,  we  now  can 
look  at  16  different  analog 
voltages  without  the  maze 
of  confusion  mentioned 
above. 

The  operation  of  the  DAS 


Fig.  3,  The  PC  board  foil  pattern  for  the  schematic  of  Fig.  2.  The  pattern  is  shown  from  the 
foil  side. 


M 


is  really  very  simple  Lef  s 
assume  an  initial  starting 
point  for  the  DAS  with  the 
counter  set  to  binary  zero. 
In  this  state,  the  address  in- 
puts to  each  analog  multi- 
plexer will  also  be  at  binary 
zero  and  the  chip-select 
line  will  choose  only  one  of 
the  multiplexers  to  be  ac- 
tive. Thus,  the  analog  volt* 
age  at  switch  address  zero 
will  be  connected  to  the 
A/D  and  the  conversion  pro- 
cess will  begin.  When  the 
A/D  has  converted  the  ana- 
log voltage  to  digital  form. 
It  outputs  a  pulse  from 
"Data  Valid"  to  clock  the 
counter  and  to  let  the  out- 
put circuitry  know  that  the 
digital  data  at  the  output  of 
the  A/D  is  ready  for  use. 

When  the  counter  is 
clocked,  it  is  incremented 
to  binary  0001 ,  and  the  ana- 
log voltage  at  switch  one  is 
now  connected  to  the  A/D 
for  conversion.  Again,  the 
A/D  performs  the  conver- 
sion process  and  outputs  a 
pulse  when  it  is  finished, 
and,  in  this  manner,  all  16 
analog  voltages  are  con- 
verted to  digital  form  in  a 
multiplexed  fashion  until 
you  tell  it  to  stop.  Another 
variation  to  this  approach 
would  be  to  get  rid  of  the 
counter  and  to  address  the 
analog  multiplexers  direct- 
ly with  a  microcomputer 
or  thumbwheel  switches. 
Therefore,  any  one  analog 
channel  could  be  accessed 
directly  at  any  time  and  for 
any  length  of  time  you  wish, 
without  having  to  cycle 
through  all  16  channels. 

Building  the  DAS 

Fig  2  is  a  complete 
schematic  of  a  IS-channel 

DAS  utilizing  the  Teledyne 
8700  series  of  A/D  con- 
verters! The  8700,  8701, 
and  8702  are  8-,  10-,  and 
12-bit  monolithic  CMOS 
analog-to-digital  convert- 
ers, respectively,  in  a24^in 
DIP.  Output  coding  rs  in 
binary,  and  its  conversion 
time  is  fast  enough  for 
our  purposes  (18  ms  for  8 
bits).  Its  operation  is  exactly 


134     73  Magazirte  *  December^  1980 


as  was  explained  for  the 
block  diagram  in  Fig.  1,  so 
no  other  explanation 
should  be  necessary. 

Figs.  3>  4,  and  5  (which 
were  graciously  supplied  by 
Michael  Paiva,  A/D  Product 
Manager  at  Teledyne  Semi- 
conductor) show  the  foil 
pattern,  pinout.  and  com- 
ponent layout  for  a  single- 
sided  PC  board  of  the  com- 
plete 16-channel  DAS 
shown  in  Fig.  2. 

For  those  of  you  who  do 
not  wish  to  make  your  own 
PC  board,  it  is  available 
directly  from  Teledyne  or 
any  of  their  distributors  for 
$5.00.  Just  ask  for  the  8700 
Test  Board.  Of  course,  a  PC 
board  makes  things  nice 
and  neat,  but  you  can  build 
your  own  through  wire- 
wrapping  or  direct  wiring. 

In  the  Parts  List  for  the 
DAS,  some  components  are 
marked    with    an    asterisk. 

These  are  somewhat  criti- 
cal The  stability  of  the  sys- 
tem is  directly  affected  by 
the  stability  of  these  com- 
ponents. For  standard  hob- 
by use,  however,  some  sub- 


Photo  D.  Our  finished  product  h  propped  up  against  my  computer  system. 


stjtutions  could  be  made. 
For  example,  if  an  8-bit  A/D 
is  used  at  room  tempera- 
ture, then  5%  carbon  resis- 
tors could  be  used  in  place 
of  the  1%  resistors  because 
the  resolution  of  an  8-bit 
AID  is  only  0.4%.  With  a 
12-bit  AID,  however,  these 
components  will  be  very 
critical    if    full    12-bit    ac- 


curacy is  needed. 

Following  are  a  few  sug- 
gestions that  you  may  want 
to  consider  before  building 

your  DAS: 

First,  as  in  any  project 
handling  both  digital  and 
analog  signals,  keep  analog 
signals  as  far  away  from 
digital  signals  as  possible. 
To  avoid  ground  loops,  iso- 


late the  analog  ground  from 
the  digital  ground  by  using 
the  system  ground  as  the 
only  common  point  be- 
tween the  two.  Use  ade- 
quate bypassing  of  supply 
voltages  and,  finally,  make 
sure  your  reference  volt- 
age, Vrefr  "5  ^s  Stable  as  you 
can  make  it  For  example, 
an  8-bit  A/D  should  require 


ADDRESS 
INPUT/OUTPUT 


VDD  (+5V) 
DATA  VALtD 


ENABLE/ lOOO'i  DIGIT 

BUST 
(NIHATE    CONVERSION 


DATA 
OUTPUTS 


tC5 
401! 


1C4 
4024 


\^ 


1C3 


1 


«^0  ,14. 

243Kn        loon 


> 


INPUT 


ANALOG 
INPUTS 


t-5V} 


V-REF 

ANALOG  GROUND 


fig.  4.  Component  layout  and  edge  connector  pin  assignments.  Look  carefully  for  all  jumpers. 

73  Magazine  •  December.  1980     135   J^ 


ermanti 
Aniatear 

fir*- 


^25 


MEMPHIS.  TENNESSEE 


NO  MONK€V  BUSINCSS! 

(A)  Complete  Service  Facilities 

(B)  Good  Deals  on  most  Brands 

(C)  Shipping  within  24  Hours 

(D)  All  inquiries  handled  by  Active  Hams  with 
Qver  20  years  experience  in  ham  radio 

CALL  TOLL  FREE 

1*800-238^6168 

iN  TENNESSEE,  CALL  907  452-4276 

MQNDA  Y^  SA  TURD  A  Y  8:30-5:30 

FORYOUffSPECfAL 


Write:  3202  Summer  Ave.,  Memphis,  Tennessee  38112 


Parts  List 

Part  Number 

Description 

IC1,  IC2 

4051 

CMOS— 8-channe  analog 
switch 

IC3 

8700  type 

CMOS— Teledyne  AID  converter 

IC4 

4024 

CMOS— 7'bit  binary  counter 

IC5 

4011 

CMOS    quad  ainput  NAND 
gate 

C1 

68  pF  ±  1 0% 

Low  leakage  ntica,  ceramic*  etc. 

C2 

270  pF  ±  20% 

Ceramic,  mica,  etc. 

G3,  C4.  C5 

0.1  mF  ±  20% 

Ceramic,  mylar,  electrolytic,  tan 
talum,  etc. 

R1 

*953k  ±  1% 

Carbon,  carbon  film,  metal  film, 
etc. 

R2 

*100k  ±  10% 

Trimmer  resistor 

R3 

*1  megohm  ± 

1% 

Carbon,  cafbon  film,  metal  film, 
etc. 

R4 

100Q  ±  10% 

Carbon  resistor 

R5 

20k  ±  10% 

Trimmer  resistor 

R6 

100k  ±  5% 

Carbon  resistor 

R7 

Ik  ±  5% 

Carbon  resistor 

R8 

100k  ±  10% 

Carbon  resistor 

R9 

•20k  ±  10% 

Trimmer  resistor 

RIO 

*243k  ±  1% 

Carbon,  carbon  film,  metal  film, 
etc. 

*See  text. 

0-04%    v< 

^Itaee   reeulal 

tion 

Reference 

(one-tenth  of  its  resolution). 
Photo  D  shows  my  com- 
pleted DAS  in  front  of  my 
computer  system /■ 


1.  Teledyne  Semiconductor, 
AN-9,  "Applications  of  the  8700 
Series  of  CMOS  AID  Convert- 


ers. 


encounter 


Dateline  Dayton  Hamvention  .  . 

To  dennonttrate  the  selectlvtty  of  our  Mark  3CR  repeater  we  keyed  a 
trantmitler  1 5  KHz  off  frequency  and  set  It  directly  agalnet  the  receiver 
Input.  Our  Mark  3CR  didn't  even  notice  the  dote  encounter. 


Sure  the  Mark  3CR  can  withstand  severe  interference. . 
it  uses  both  crystal  filtering  and  double  conversion. 
And  that's  just  the  beginning.  Its  perforrrtance  contin- 
ues with  a  transmitter  that  meets  commercial  specs 
plus  a  microprocessor  controller  that  gives  you  39 
functions  and  13  Morse  messages.  For  peak  perform- 
ance have  your  own  close  encounter  with  a  Mark  3CR  / 
Repeater  or  Mark  3C  Controller 


call  or  write  for  specif Icatlone    '^49 
MICRO  CONTROL  SPECIALTIES 
23  Elm  Park,  Groveland,  Ma.  01834 

(617)  372-3442 


^2 


136     73  Magazine  •  December,  1980 


ITEM  NO 

WK7 


IC  INSERTION/EXTRACTION  KIT 


t^S» 


•  MOS-UIS    14-16  CMOS  SAFE  INSERTER 


•  EX-1     14-16  EXTRACTOR 


KIT  INCLUDES    •  IIO»-242i    24-28  CMOS  safe  inserter    ;":;     anS  CMOS  SAFE  EXTRACTOR 

•  MOS-40        36-40  CMOS  SAFE  INSERTER     '  "^     ^*^"  *^'*°*  ^""^^  EXTRACTOR 


OK  MACHINE  &  TOOl  CORPORATION 

3455  CONNER  ST  ,feRONX,N.Y,  10475US.A 

PNONC  i2^7f  914  660g  ftlE*  NO  UVO^l 


PfliNTtD   IN   U*-*. 


Latent  pinpinc 


MOS-242S 


MOS-141S 


MOS-40 


EX-2 


I    WK-7 


COMPLETE  IC  INSERTER /EXTRACTOR  KIT    |    $29.95    | 


I    MOS-1416 


MOS-2428 


MOS-40 


EX-1 


EX-2 


INDIVIDUAL   COMPONENTS 


14-16  PIN  MOS  CMOS  SAFE  INSERTER 


24-28  PIN  MOS  CMOS  SAFE  INSERTER 


36-40  PIN  MOS  CMOS  SAFE  INSERTER 


14-16  PIN  EXTRACTOR  TOOL 


24-40  PIN  CMOS  SAFE  EXTRACTOR  TOOL 


$  7.95 


$  7.95 


$  7.95 


$  1.49 


$  7.95 


MNIMUM  BIUING  $25.00.  ADD  SHIPPING  CHAftC£  $3.00.  NCW  YOUK  RESIDENTS  ADD  APPLICABLl  TAX. 


OK  MACHINE  &  TOOL  CORPORATION  3455  CONNER  ST.,  BRONX.  N.Y.  10475  (212)  994-6600/TELEX  125091 


t>^  fl»«otef  S^vicc — see  p^ge  226 


73  Magazine  •  December,  1980     137 


Ed  ingbef  WA6AXX 
10&16  Nonhridge  Square 
Cupertino  CA  95014 


A  Computer-Controlled 

Talking  Repeater 

part  III:  interfacing  to  the  microcomputer 


The  first  two  parts  of  this 
article  provided  an 
overview  of  the  project  and 
microcomputer  hardware 
and  software  nucleus  de- 
tails. This  final  part  de- 
scribes interfacing  of  var- 


ious peripheral  circuits  to 
the  microcomputer. 

Speech  Synthesizer 

The  most  distinctive 
characteristic  of  the  repeat- 
er is  its  voice,  provided  by 


Telesensory  Systems'  S2B 
and  S2C  Mini  Speech  Syn- 
thesis PC  boards.  Each 
board  has  a  vocabulary  of 
64  words.  The  S2C  contains 
the  ASCII  character  set  and 
the  S2B  provides  64  addi- 


^|i|iii{i|t|i|iii|immmi{i  i|tMi|i  i|i|t|i|i 


Minr  iM  11  s 


a 


2 


•*^^mm 


murnm 


|«^*W«IM 


3 


4 


!l  III  III 


5 


Photo  A.  Telesensory  Systems  speech  synthesizer  board. 
'JH  13a     73  Magazine  •  Oecember,  1980 


tional  words  such  as  ten, 
eleven,  twenty,  thirty,  hun- 
dred, clear,  Hertz,  and 
other  useful  radio-type 
words.  The  speech  syn- 
thesizer is  used  for  IDing 
the  repeater,  reading  back 
commands,  and  for  reading 
out  signal  strength  and  fre- 
quency  error  measure- 
ments. The  boards  are 
perfect  for  countless  other 
microcomputer-based  ap- 
plications including  remote 
bases,  home  remote- 
control  systems,  and 
speech-response  terminals. 
Each  board  is  about  3" 
by  3"  with  a  20-pin  connec- 
tor on  one  end.  They  cor>- 

tain  a  40-pin  LSI  synthesizer 

chip,  24-pin  ROMs  contain- 
ing the  vocabulary,  and  a 
couple  of  resistors  and  ca- 
pacitors. The  internal  clock 
frequency  is  controlled  by 
an  RC  network,  but  if  de- 
sired, the  board  can  be  driv- 
en by  an  external  clock  for 
more  precise  pitch  control. 
To  generate  speech,  a  six- 
bit  binary  code  represent- 
ing the  desired  word  is  ap- 
plied to  the  board  and  the 
start  input  is  pulsed.  The 
busy  output  signal  goes 
low,  remaining  low  until  the 
word  is  complete.  The  code 
for  the  next  word  can  then 


be  applied,  the  start  input 
pulsed,  etc.  It  couldn't  be 
easierf 

The  Telesensory  speech 
synthesizers  are  fund  a  men- 
tally different  from  syn- 
thesizers that  have  been 
available  for  hobby  com- 
puters. Control  requires  on- 
ly presenting  the  six-bit  rep- 
resentation of  the  word  de- 
sired. Other  synthesizers  re- 
quire a  complex  construc- 
tion of  commands  for  each 
word,  and  it  becomes  a 
game  to  understand  what 
the  machine  actually  said. 
Such  systems  are  really 
toys  — not  tools  If  only  a 
limited  vocabulary  is  re- 
quired, the  Telesensory 
boards  are  the  perfect  solu- 
tion. The  voice  sounds  au- 
thoritative, rather  than 
friendly  like  the  voice  of 
the  Tl  Speak  and  SpeltT^*, 
and  is  more  intelligible  and 
punches  through  any  back- 
ground noise. 

Synthesizer  Hardware 
Interface 

The  pitch  of  the  speech 
output  normally  is  deter- 
mined by  the  board's  RC  os- 
cillator circuit.  By  removing 
the  resistor  and  capacitor, 
an  external  clock  signal  can 
be  used  to  eliminate  the 
possibility  of  frequency 
drift  with  time  or  tempera- 
ture and  to  precisely  match 
the  pitch  of  the  two  boards. 
The  clock  signal  is  gen- 
erated by  a  programmable 
counter/timer  on  the 
Pragmatic  Designs  CPU*1A 
microcomputer  board, 
dividing  the  CPU's  crystal- 
controlled  clock  frequency 
to  24  kHz. 

The  six-bit  word-select 
code  for  both  boards  is  pro- 
vided by  the  computer's 
DACPORT  output  port,  and 
the  individual  start  strobes 
are  provided  by  two  bits  of 
XPORT  output  port  To 
guarantee  logic  level  com- 
patibility, pull-up  resistors 
to  +5  volts  are  included 
for  each  synthesizer  input 
line. 

The  synthesizers'  busy 
output  lines  require  a  srm- 


Photo  B.  IC~22S  with  interface  board  plugged  into  old  diode  programmtrig  board  location, 
Molex  connector  on  back  carries  all  the  signals 


pie  interface  circuit  to  drive 
5-volt  logic.  The  signals  are 
brought  into  the  8085  As  in- 
terrupt 5.5  and  6.5  inputs, 
used  as  an  input  port  —  not 
really  as  interrupt  inputs. 

The  speech  output  is  a 
high-impedance  [lOk)  cou- 


ple of  volts  peak  to  peak. 
Telesensory  recommends  a 
filter  network  to  shape  the 

audio  response,  but  we 
found  that  it  sounded  far 
better  through  the  repeater 
with  virtually  no  filtering. 
The   audio   from    the   two 


boards  goes  to  the  repeat- 
er's audio  mixer  circuits. 

Synthesizer  Software 

Messages  to  be  spoken 
are    generally    stored    as 

strings  in  the  microcompu- 
ter's ROM.  Other  messages 


30K1$I 


DACPORT    9 

OACPOHT    4     > 

DACPOnr  J  > 

aACPDHT  2  y- 

04CPOffT    i 

CMCPCMT  O  > 
SPEECit  »  V 
STfflOBE        ^ 

TIMER  OUT 
I24KHEI 

INTEflftUPT  5  S>— f 


SPtEtM  a 


INTERRUPT  6  5 


TO 

JLuOlO 

MIXERS 


Fig.  1.  Speech  synthesizer  hardware  interface  to  microcomputer. 

73  Magaitne  •  December.  1980    139   ^ 


Table  1.  Speech  SYnthesizer  contiol  subroutine. 


1V4C  •• 
7530  - 
0032  - 

323C  - 


3390 


37A6 

324* 
32^7 

32«C 


n 

0312 

CM703J 

D31A 


3270  ■ 
^270   f b 

3271  7e 

3272  23 

3273  fEFO 
3J7B  IM7F32 
3S7S  C&OF 

337*  rttyf 


a27F 
327F 

J2B1 
32fl< 
32^ 
326^ 
32eP 
37BD 
32F0 


FTM 

C*31S3 

C430 
f£3» 
C?»233 
3C2A 


3292   * 
32f3   FE3C 
329^   C2?*32 
E^7   3£1J 


32»f 
139<f 
3»t 


3?ft 

3;^A0 
32Ar 
32fi3 
3ZAd 
32A^ 

^2An 

32AD 
32AF 


F» 

7«i 

rj 

fr*3; 

[:;a232 
Er2ft 

FC*0 
D2P21:? 
OAF> 
C 3 1432 


32B2  « 

3211?  (MiF? 

35**  * 

X2»4  Oil 3 

32&«  AO 

32* r  P3t2 

32>^  ri 

32BA  ^4 

320f  Fi 

32«C  7A 

3200  E7 

32 B€  ?l320fl 

32C]  2Z2FI0 


(HL>->   OHJUCfEV   STiriMB, 


9CH 


tSfEECN   SVHTHESIZEJ?   COIfritOt   ROuTIliE* 

ICHMUhCTER    STREM;    TttrMlHATEO  tV   OTTH^ 

ICmtl   20H    TO  3FH    AtlC    i^5.ClJ.    CODES   *OH   ID    9FU 

IMS    ftLE<^El«SD«r    'STAHtmllti'*    UOCABULAHr.       COBf^^  C^    TO 

IMtE    iCP   AND   STAB/POUNC>    rf>Ah   NQT   USE  Hi  . 

lEF    r70   SPEC  CM   IS    triTteRur  tFD  *    ROUtlNE    ItETURHiS  UUH  C¥»l. 

I 

I  INTER  CHARACTER  DELftT 

I  INTER   HOfitt   Ml  AT 

|lfll>eECH   HALFUHCTION'    TlH£ft-t  »3    mc 


8l>WaRllCLA¥   EC»U   30000 
TBPTtrt      EOU   50 


I 

TALK 

t 

TAiHl 


I 

T AUK ID 


fMLKtC 


TALK  IV 


fALKlA 


I 

TALfCl 

t 
TALKJ 


EOU    t 
f>U3H   • 

EOU    » 
Dt 

IN 

DifT  xpQirr 

C4LL    TT«CvfirEST    I  TALK  1MB    Tf}   «*§[£}  Oft   PlQue^ 


iFROTECr   CRiriCM.    AREA 
»TMT   iOlM  fTRO«lS   HIBH 
VTGTt 


JZ    TAIKIP 
Alfl    atOftTDZ^fi 

mtj  *uot 

EDU   t 

It 

INN    H 
ttt    OFOH 
JC    T AUK IE 
IW]     QFH 

Ji  rifrrALjc 
cri  20H 

CPl  OPM 

JMC  T#LliiA 

Mil;  SON 

CPI  3VN 

JHt  TALKIB 

CPU   « 

JUt    TALfEiA 
fVU^t   «i2LSl 

eou  t 

CI 

ll,t 

ftl 

ttrf  nACPwr 

iMt   B«50 
C)C«  p 
JMZ  i-i 
xni  20ti 

C^t  dOH 

JHC  TALK2 

HVI  B»9PlUNSTEIi 

JMP  fALR3 

iOU   « 

KMl    ••S«*2UM«Tt 

tOrU  * 

IN  ipwrr 


OUT   KfUPT 

Ct 

l«.T 

CI 

m.T 

PUSH  M 

LWI    H»rSPTIH 

$HLB   LEPT 


iif  TD  ^Mcmcr  MUT  mm  R» 

IICOH    lU   IUI»tO   tf)   290  IriTR 


lOET    CHAR  ACT  Eft 

fCHAR   Fmm  AUTOOtAL   HE:n-F 

IIF   YEB.    THE*   MS*.   OFf   HS   ilTS   90 
I<LAST    CMMI"^    fHHiilltACTER    FFTf 
«FlJiISHeD    IF    TCI 


IMQT  riNISMCP*  f)PAC£^ 
tIF  TESr  JUST  DCLAT 
I  BCD  m.    STAA/PDUHDT 

t^EEp  CONVCRT  TD  ASZlI 
f|5  rr  ETART 

IIF  TES,  UBE  TELES  EODi 


BCD 


I  IB    U  POUHO* 

tiFSE    HiUHBER    fPOlMil} 


IWCWEIWE  »tT  S  TO   HATHH    TfLES  tXOt. 

iSTHCHOKWirE    TO   RSTTS   TO   IKMIAMTEE   SETUP 

lAMD   HOLD   TlNCSt    OUTPUT   TO  BTlfrH   ZMTA 
IBCIAT   tg   OBSERVE   SETUP  KWflKiieHTS 


I  FLIP  8ftCK  BIT  a 

rAQCII    OR   STAKPAIilP   VQCAVULARTT 

MSCItt    SQARE)    1    UNITROBE 


IBTANtHUDf    tOMTD  2  IINSTROK 


•  iMD   ALIDM   BCiAtr   OF   BUS?    LtHC 


iSlOflE  ^ALFUNQTIPN    TIHEDUT     IH 
p    QEHERAL    PURPOSE    TlhtER 


32C4   = 

33!&442D 
12CS  EA3« 
3JC7  C33»^ 
3SCA  3I^2»19 
32C5   TD 
32CE   M 
37CF    CAF^J? 
32C?   tlBlA 
3^M   E&OB 
3Zn&   CAF?33 
3?D?   3A4#10 
33DC   <JF 
3200   BAFS32 
32C<»  3A451.0 
32C3  «r 
32C4    MF532 
32C7   3A*DiO 

33iE«  or 

32EB   SAF^32 
37CE    3M4EtO 
12n    OF 
33F2  D2FDS7 

32F5  - 

33F5  2A2F]« 

32Fe  ?D 

J2F*  B4 

32FA  C2t:432 

SaFD   = 
33FII   F3 
32f£    DStA 
3»0  C4F7 
33«2   03^1  A 
3304   Fft 

33«  - 

33«5420 
33DA  tdK^ 
33eS  C2I333 
330B  242FI0 

JIOE  7D 
330F  B4 

3310  C  201533 

3313  ■ 

3313  37 

3314  El 


TALJ(4 


331 S 

3315 
331^ 
3317 
3318 

3311 

niD 

331F 
9322 

3324 
332A 


F3 
CI 

F3 

3*^1 i« 

E«Zt 

FE2» 

C22B33 

DBIA 

Fd02 

D31A 


332  B  = 
332D  Fl 
332*  FB 
332A  t9 

332t   = 

9m   El 
I32C   0t4ClD 

jsar  - 

33^   €py*34 
"SitXi  C3SD33 


333^   • 
3339   013D7S 
3338   C32F33 


eau  t 

Rlfi 


lEPEEOi  FIMISHCBT 


Jhl    TALKS 
t.Ht.9  LTT»EEP 

DATA   H 

JZ    TALK4A 

IN   AUBl 

AHl  aBPT0220 

SI    TALK4fl 

LPA    My ANN 

RRC 

JC    TAL*^4A 

LM  Pf  TliARM 

RRC 

JC    TAi1h4A 

L»A  PCOVCir 

HHC 

^^^^-        w  MIL  K^rfll 

itt*   TT^OIffR 

ffiRC 

TALK4fl      fHU  4 

iMLO  tOPT 

nov  *iU 

DRA   H 

t^LKAEPORT    E[Mi    t 
Dt 
In    MIDI 

mi  ^st^tn^ 

out   AUDI 
fl 

I 

TA4.KA*dfrn   EOU  « 

RIM 

M  >W 

Aiti  iHr«;j 

Jtfl    TALK  abort:! 
UCO  LWf 
MOM   ll«L 
OR  A   H 

JNZ    TALhftBOftTl 
f 
TALKABORTS   EOU   I 

arc 

POP   H 

I 

FtJrTMJC  EWf  « 

at 

n»  m 

LIM  RBCP 

AMI    5SBCN  OR  «imOI« 

Crt   WOKM  OR   SRBfiOM 

j*iz  nifTALKi 

IN   AUDI 

ORt  SRPftT022* 

OUT    AUDI 


IJW    IF   IHIWE    IrfORD 
»22«  BaUELCH  13lPfl4v 


IHO*    Ei^TINUE 

lf^E8»>    lALKlNO    TO   RADIOS 

INO^    CONTINUE 

ircfii  noNOLO^uE  uarh  annct 

ITES*    CONTINUE 
IPATCM    TIAEA  WAI^HlHOT 

»rElf    CONTINUE 
tHO>   COUER   TONE* 


ITT   COVER  TVEV 


INQ*    HALF  TtHGt    TIHES  IWTT 


ITESt   ABO^T 

iican  speeek  audio 


lUAtT   FOR  EMB  OT   SPEECH 

iehecrl  half  tincr 

ILDDP   UNTIL   DOlte 

fSET    CT   FDR    INTEKRUPTED  RETURN 


iWCOiBCCT    Rl   AOVJO   IF   MCeXS^ART 


IRCCONHECT 


FTNTALKt  EOU  t 
POP  PflW 

Er 

RET 

I 

rALK5         EDtJ   i 

par  H 

LXt   i-VDELUr 

t 

CALL    DEL 2 

jnP   TibLlcl 
I 
I 

IDCLAT   tKlRD   SPA^   TJHE 
t 
SPACETALK   EOU   4 

tKI    BrSP^DfitlELAT 

JNP   TALK&A 


IINTER  OMR   aCLAT 


Q  AC PORT 
OACPOHT 
DACPORT 
DA C PORT 
aACPORT 
OACPORT 
QAC^ORT 
DACPORT 


Q 
) 

2 
3 

4 

9 
« 

T 


> 


•ItV 


JT 


Mf« 


I 


^ 


VReF+         ¥4 


i« 

•7 
H 


OAe-OB 


B5 
ft* 


14 


m 


»3 


-  U 

-fll 


VHEf  ■ 


CORIP 


/TT 


r 


] ;  ^3K 


3X 


lOK 


+  IZV 


-lOV 


*5V 
4 


INPWTS)- 


VDD        VQit 


409  IB 


eoii 

VEE 


40        A] 


A/D   CH  l>- 


■lOV 


m 


TONE   TO 
AUDiOUdXERS 


+  iEV 


♦ay 


5lt 


■<A/«  comutATon 


-10V 


Fig,  2.  A/D  converter  hardware  for  reading  the  meters. 
Im   140     73 Magazine  •  December;l980 


are  generated  by  computa- 
tions made  by  the  com- 
puter and  are  stored  as 
strings  in  RAM.  Prior  to  gen- 
erating speech,  the  compu- 
ter enables  the  synthesiz- 
er's audio  mixer  to  the 
transmitter  and/or  phone 
line.  The  TALK  subroutine 
expects  the  HL  register  pair 
to  point  to  the  character 
string  in  memory,  and  the 
string  is  terminated  by  a 
OFFH  code.  If  speech  to  the 
transmitter  is  interrupted 
by  a  receiver  squelch  open, 
speech  aborts  and  the  sub- 
routine returns  with  the 
carry  flag  set.  There  are  cer- 
tain exceptions  to  this  rule, 
including  timeout  an- 
nouncements  and  cover 
tone  generation. 
The  TALK  subroutine  is 


Table  2,  Meter-tBad  program  extracted  from  the  back- 
ground  module,  TRAP  interrupt  module,  and  foreground 
module. 


I    «*«    PulCKGIKrUHCi    f^TE«    REAP   t«« 

liATA    AC«UI5ITIDH,       IICH    CfXurrfP)    fiFTEimiNES   A   QMHNEL    TD    K 

IMCASlWED   fcy  A/b  COHVEItTTlt'      VALUC    EPfTERCI^    IWTD  flHJPER 


diDu  » 

oiE);i  niti 

OtiO  C4FC 

OUe   7E 

dlD9  £603 
DlDI  do 
OtBC  D313 

01E«  OEM 


«ie3 

0tE4 
01E9 
01E7 
tllEB 
OlEV 
Ol£A 

aiEi 

OlED 
OICF 

01F3 
01 M 


Af 
47 
D311 

w 

£480 

csrsoi 
m 

4? 


#1F3  ■ 

«IF4  <W 
OU^  4f 


om 

OlFB 
Olft 
OlFF 
0200 
0203 
0204 
0204 

oaw 

020C 

ojor 


ZA04tei 
70 

220410 

F£M 

317410 
2^0410 
C3P900 


04E4   - 
04f4    0)7410 
1$4F/  CJCIKM 


04EA   0t7iFll» 
04ED   - 

04EB  r>9 
04£i  e;t 

04EF    210000 
04F?   I I 0000 

fl*Fa  ■ 

04F5   04 

0*F7  1* 
04F&  03 
04F9  03 
OtFA  03 
04f^»  03 
44FC  TV 
04F1II  FE94 
04FF  94r504 
OS03   2f 

0303  29 

0304  29 
0505  2* 


ItKATtOfi   &F   4/0   lABLE* 

I  OF    4   CHAN^LS. 

» 

AATAACP    EOU   « 

IM  CWtNlf 

AMI  HOT  AOHASK 

hOV   i*4 

MKl   ApH 

AMI    ADHA^ 

OftA   3 

OUT   CHPDRT 


I 


I 


data:? 


HUt  s*o 

ffUl   CrBOH 

CDU   t 

IRA  C 

DUT    DACPDRT 

WDP 

WOP 

HOP 

HOP 

IN   epOUT 

ANI   APOMra 

JHZ   ttATA? 

HDV  Art 

irtA  r 

AOV   B>4 

E[?U   t 
HDir  ArC 
ftRC 
npv  CfA 

JHC  HAT At 


TABLE  CDHTAIHS  LA9t  14  MEASURE ntMTS 


I  SELECT  A/0  C94AHHCL 

tcucteenT  marr  value 

tTIOt   COUftTEK 

lis   2   BITS 

I  DR  IN  A/D  CHANMCi  BUS 

lAND  SELECT 

IBUCCESS1VE    Af'PRDXIHATION    A/H   CDHUERSIDH 
IMCllRREHT    VALUE*    CmHASIi,    »IT 


Iter  HCKT  VIT 


lAWP    5EWti   CURRENT   t/ALUE   TO   PAC 

lALLDU    np   AHP    TO   ^EU 


fldOK   AT   COH^ARATOR 

Itr  HI^«  LEAVC  SET 
fir  LDU*  CLTAft  IT 


IfjUCKT  IIASK 


lOWTJliUE    FOB   8   rOSJTIDM 


IIATA3 


EPU    • 

LHLD  CURREHTUALUE   FA/P  TA»LE  POINTEK 

nOU  HfB  I PUT  UALUE  IHTD    TABLE 

Ink  h 

SHLD   CURRENTVALUf 

HOV   AfU  luAAPf^ft&yNO'» 

CPI    LMI    FIHADTAPUE 

JH7   FIN7S  fHO*    DOME 

Lltl    H*AQTA>LE         ItCS*    URA^  AirOiMP    TO  KDlilH|f« 

fllLD   CtHrREMTVACilE 


iUtt    TRAP    RDUtthtEr    AL^e:rAQE    READINGS   ANO    BTE>RE    4** 


t 
I 
I 
I 

L«T   1>ADTA8LE 
JAP   AV6IT 

1 

TRAPIMET   EOU  t 

t.](f    B*A0TAALE4^1    J  CHANNEL    J    ITlCit    Hi    15   PHETER 
J 


lOMMHEU    O   ITICK   4>    IS   SMETIP^ 
t(KI-v  flTMtf   OF    SHETEH   «AM   VALUES 


AUGIt 


£(3U    ■ 

PlrtlM    D 

L:V£  K«0 
LJtr   B>0 


lAUERAQE   PREVIOiUS    14   REAOtHaS 

lOJtlULATlUE   mm 
l^tE-ltEXT    VALUE 


iMisrri 


wmi  « 

LEMX   P 
WV  E-A 

PAP   D 

iNir  e 

INK   E 

IMX    B 

tHI   B 

HQV   AfC 

CPI    LDU   FtMADTAH^    tHME^ 

JC  AVQITl 

DAO   H  pTES*    NON   OET   8   ttSO 

PAD   H 

DAD    H 

PAD   H  iX    lib    IN   NL 


ISfT   VALUE 

IDE -VALUE 

PMfy    SUM    IP4   HL 


IMErr   VALUE 


01504    JE 

NOV  A^H 

0^07    32«9i0 

ST  A  fICAOlHO 

^:^50fr  2A2510 

LHLA    LftT 

050D   220710 

SHLO    READ TI HE 

OHIO    El 

POP   H 

0511    Dl 

POP  n 

0312   tV 

R£T 

fttS   BYTE   18   AVEHflSE 
fSTORE    tt 

f  STORE  naNOLnGi^  rtmis   so  knqn 

TWAT   MIKE   NELD   DkWN    LOMG   ENOUOH 


I 


I    Ht   FDHEIMOCPV  ViOUrWCE    HCCDPE   ROUTtME:   m 
i    5-nEtEV   AN!}    SISCNINIHATCW   REAOi   AHNQUHCElWirr * 


<»BDa    31&90C 
OBDB    110400 


e«K:  3Ad#io 

0>ri  47 


0K3  7E 
OKS  18 
0BE4  P2F40n 
0BE7  If 
OBi£«  i:3C:20P 


OBE>  * 
OBEB  71434C 
OBEE  110800 
OBFl  C3DE0B 

&Ar4  - 

OBf  4   23 

obfa  zAevjo 

OBTf    tifidCl 
OlFC    t? 
OBFA   El 
OBFE   BA4F0e 
OCOl    CP3B3;t 

0C04+E7 


0C05  ff2S530FrM 
dCfih  F)4S33lFFOO 
QCll  Ba533;'FF00 
0C17  fOS333Froo 
OCtH  9B5334Fr00 
0C;3  A0531SFrOO 
0C2V  A89334rF0« 
OCTT  >O5337rF0O 
0CJ5  B85338rF0O 
M^3P  C093JVFF0O 
0C41  CeS3392»4A 
0C4  7  D0533V3'D74 
OC40  na533VyE75 
0CS3  E0533VJB7S 
0C39  EB533V2»77 
OtSf  FP533*S»7e 
OCAS  - 


0C49 


SSftETER  £mi   • 
I 

LXI  NrSMETABLe 

LXl    OiA 
f 
SSHFTTtl  EOy  4 

LOA  HEAD I NO 

ffDV  ivA 
f 

ssffHTEira  eiK/  t 

IWV   Alii 
JNC    NETALK 

rvAD  p 

JHP   f  BfliTEIt? 

t 

>P-METn!^   ANHdUMIceNCHT. 

r 

DOilETE^   EOU   4 

f-XI  NfOHETABLE 

LXl  P.P 

JHP   BBHETERl 


I  POINT    TO    TAiLE 

»AOD   CCJMSTAMT 


I8ET  LAST  AVESAflEX  VALUE 


fcnmECT  vALurr 


fIF   NOT* 


3AV    VALUE 

Tfftr    NEXT   VALUE 


I 
NEtALK 


EOU    • 

IttX    M 

PUSH   H 

LM.a   AEA0TIt« 

LX!    D#-4T1<IT-3QJ 

DAO    fi 

JC   FINSED 

CALL    HALKH 
jnPFIMSED 
RST   4 


tPOIHT    TO    TAtLE 
fABD   COMSrAMl 
ICOHTINUIE 


I  POINT    TO    FIRST   CHARACTER 

I SAVE  FDiHTEA 

flMii   HIKE    WLD    POUM    FQA 

I    At   LEAST    1/2   SECSmP 

I    90  NAVE    VALID    AVEffAQE* 

lACttOfiC   POINTER 

t ABORT    IF    m 

tSAf    IT 

»DOHE 


AMO  SP^CH 


pS-niTER    TAME    OF   VAitJC 
t 

^METABLE   EOU  « 

OP  p»i.^so'*orFK*a,« 

|ip  94N#  'SI  '  'OFFHr^FO- 
PP  P8H*'S?'  .aFFHrftrO 
PB  ?PHIf  'S3%OFFHfO*0 
PB  VRH* 'S4'«0I  FHpOpO 
pf     PA^H^'S^     ^OFTHrOfO 

i'S4'*0FFHpO-0 

P 'S7^iOFFHpO*0 

f 'Sa'*OFFM»0*0 
B0  OdOHP^SV 
t>8  OCBll*'St 
VB   ODOHr 
DB   OPSH- 
DB   OEOHp 
BB   OESHt 
HP   OFF Hi 
FIHSrKTASLE   EOU  4 
t 

iDisemnfiMroiv  werrEn  taple  or  value  Am  spcfcn 
f 

BHE TABLE   EOU   • 


iOFFH»OiO 

*l>I.US»reNiOFFIf 

fF-Lt^pTMEHTT*OFFN 

fPLUS.pTM|«TT*OFFH 
*f»LIJSiFDRTV*OFFH 
S4' ^PLUSfFIFTTpOFFH 
ST'.PHS.ai«tirrOfFH 


'S¥ 


BB  38HrHINyS> 
PB  «2H*NlNU6t 
M  ACHpHIHUSi 
DR  70H«nl'NUSt 
Of    :r4M.»trMJBp 


1F2P3E354S 
0C4D  2C2&3S4BTA 
0C75  447!T)334B?4 
0C7&  5fi21ll24>y4 
0CP3  42?P31B33S 
OC»P  4C2B3l4i»A 
0Cf5  ?02£iJfl7CT4 
OCTD  747JJ347Cf4 
OCAS  782B347C?4 
OCAB  7C211327C?A 
0CB5  e43C32?CVd 
OCBB  B82B327C9A 
0CC5  BC2B3*/C^Ni 
OCCH  V02B347C9d 
0Cti3  f4?P587Cf4 
DCOP   VP2P314p?4  H 

0CE3   4^1318135  WB 

OC£P   &{:2i-l24P9A  n 

OCfS   P42B334BV6  pp 

OCFD   £12B354B^&  DP 

OPOS   FF2B3E334B  OP 

ODOP    >  rtNPEHETABLE   EOU 

I 


BB    IFH  rHTNDfi  FOf^rAT^ffTHAflr  '5K '  r HERTZ ■  OFFH*0 
BB    3CHfHI#JU§.    5l<'*H£^TZrOFFHrOpO 
D^B    44N>NlNUef '3K^iHERT7f0FFHp0pC> 
2*£'-ME«Tr*0FFH*0*& 
1  '  *f^INT  r  •  5K  '  pNEI^rZ>4FFM 
iJC' 1 1CRTZ  iilhFFNi  Oi  0 
8 '  #MJHMED  fHCSI r<  OFFHpOpO 
4 '  P  AVHPVEII  p  tifli '  I  i  OFFH  *  0  *  0 
D»   7»4iHJMUSp'4'FHUH>IIEDtHCKtr»OFFHpO*0 
OB   7i:HiMIMilS''2'tMJmwrPfHERT2F0«7H,0.0 
PB    B4t4»i.EBSTHAN*'2'  tHUNPREBFHERTZrOFFHpOvO 
PB    BflK'PLUBf 
PB    BCM-FLU5-    4 

'  6 '  ,  HUVPBEOf  HERTZ  » CUFFM  i  0  p  P 
'  B  P  HUKpnCP  pl'EJ?  T  ;  t  OFFMp  0«  O 
'  IK  '  pPC*f^p4IFFH*0#0 

l/«PQJIiT«  'W.||C«T2#0FFH 


PR 


tOM-PLUSip 
tA«-PLU5» 
rPLIiSi 
fPLUBp 


2  '  T HUhriiKrn  fHERTZ  tOFFHi  0 1  0 
' HUNPRED  pHERT;*OFFHp  OpO 


OSCH  t  PL  US*  '  2K ' .  NTKT  Z  P  Of  r  H 1 0  *  0 
Otl4HrPLUSt'3K'  fHEATZpWTH«OpO 
OCIHpPLUS*  'Sk'  »hCRT2*^FH*0pO 
OFFHiiPLUSfPREATCRTHAHr  '  SK'  pHERTJ>0FFHpC^ 

4 


listed  in  Table  1,  Optimum 

selection  of  the  synthesiz- 
er's pitch  and  inter-charac- 
ter delay  is  essential  to 
achieving  the  best  intelligi- 
bility. 

Meter  Read 

The    repeater's    meter* 
read  capability  allows  users 

to  request  S-meter  and  dis- 
criminator meter  readings 
to  check  signal  strength  and 
frequency  error.  Analog 
voltages  from  the  receiver 
are  buffered  and  brought  to 
the  A/D  converter  on  the 
CPU-1 A  microcomputer 
board  Provisions  are  made 
for  four   analog   channels. 


although  only  two  are  used 
presently.  The  background 
module  measures  each 
channel  every  26,6  ms,  and 
the  reading  is  stored  with 
the  1 5  previous  readings  for 
that  channel  in  RAM.  When 
the    proper    touchtoneTM 

key  sequence  is  detected 
by  the  TRAP  interrupt 
module,  the  16  readings  for 
the  appropriate  channel  are 
averaged  and  stored,  to  be 
retrieved  by  the  foreground 
sequence-detect  branch 
routine  which  speaks  the 
meter  value  over  the  air- 
When  a  meter-read  com- 
mand is  entered,  therefore, 
the   average    reading   over 


the  last  half  second  is  read, 
reducing  the  effect  of  noise 
and  ffutter. 

The  A/D  converter  con- 
sists of  a  DAC^OB  8-bit 
digital-to-analog  converter 
with  a  current-to-voltage 
converter,  analog  multi- 
plexer, and  comparator. 
The  DAC  is  driven  by  D AC- 
PORT  output  port  the 
multiplexer  by  CHPORT 
output  port,  and  the  com- 
parator is  read  through 
RPORT  input  port.  A  300-^ 
total  conversion  time  suc- 
cessive approximation 
algorithm  is  used. 

The  meter-read  software 
consists  of  three  routines  in 


the  background,  TRAP  in- 
terrupt, and  foreground 
modules.  The  listings  of 
each  are  shown  in  Table  2. 


Remote  Base 

An  Icom  1C-22S  two- 
meter  synthesized  trans- 
ceiver serves  as  a  re- 
mote base,  commandabie 
through  the  repeater.  Com- 
mand codes  independently 
enable  the  remote-base 
receiver  and  transmitter, 
allowing  monitoring  only 
and  talking  over  the  two- 
meter  signals.  The  lC-225 
synthesizer  is  under  control 
of  the  CPU-1  A  microcom- 
puter, allowing  users  to  pro- 

73  Magazine  *  December,  1980     14t    l^ 


Table  3.  IC-22S  remote-base  frequency  control  routine. 
Touchtone  command  is  decomposed  and  determines  pro- 
gramming frequency. 


IREHOTC    9tm   FUESUEMCT   UMA  SCmiCHCr    KCQPC:   ltOUT!«tf , 
IPOIHTEII   rO  BTUT   OF   COWUUIp   SntlMQ   OH    TOP   OF    SlACli* 
flHITItnfTS  STRIHG  OF    FtMHAT    C  r«    IMEI    tlQD'S  flHZ) 
ltl«'S   hHl»    IIS   tHZl    fI-'^MOKII}f;*t]irLCX> 
i3^-^«0«ttH£   UVT   OFrfiTT)    MID  nHKHIMtl    IC-22S. 


«i7» 

> 

RPLIMeP 

EOU  i 

017» 

CI 

P»  i 

i(tc»->  BTMrr  or  srntiffi 

0»7€ 

It^lftB 

LKt    AiriMfiFD 

0»?F 

0? 

PUSH    0 

inn  FTHSEn  m  top  Of  siack 

<tMO 

3A0110 

LPA    ir»DPF 

fnp  ^HAULED  A«r>  ti**f 

0M^ 

EASQ 

AMI    9IIWrOM    OR 

SFrtnew 

OIIQS 

FE28 

E^I    9R»l^aN    OR 

SRBEN 

0687 

CO 

Hill  7 

iJSETURH    (TIJ   FtNSEn>    IF   Nd 

0B8& 

69 

NOV   LfC 

fBTRIHIj    START     ADriREfS^t 

iW&9 

6^ 

MOV   H<S 

OBOA. 

221310 

SHLH    TEMPAIR 

ISAVE   ADDRESB 

0*80 

OA 

LDA)[   > 

»TfP   STRIHB-liV40tfFF» 

OiOt 

FE^ 

CP1  a 

J CHECH    FOR    145-14?  HHf 

0B90 

£»C9 

nac 

dB^i 

FE05 

CPt  » 

0«f3 

OS 

Rf: 

0B«4 

cua« 

Wf    A 

f  ST  APT    FpfiMTIfG    tmLUC 

a*f4 

2ie803 

LXi  iramw 

d*w 

CMiSJai 

JE  MLOlkn 

0B9C 

2iaOH«j 

Ufl  it.o 

«tfF 

FiWIS^B 

JH  ••LQAOl 

OVA? 

3111007 

HBLOAPI 

LUI    H»20qO 

15-  -O* *-  >  I OOW  *  7  '  -21KM1 

et«s 

. 

ow  * 

0«M 

Odi 

l«fl  » 

«■*« 

«* 

LPAH    i 

ItlMfVEKt    KB    to   0-?T79  BJiM 

*i*y 

llA+C^ 

LXI    P>tOO 

IIClOO    (HlfllMH:lrs> 

0I4MI 

. 

EOU    * 

etJM 

as 

DOI   A 

OMI 

FAB^OB 

jn    IIIILlM(!3 

OMC 

i* 

BAB    B 

0»#F 

C3AM)B 

RPL0AD3 

jnp  RDLEMtn:! 

0»»? 

• 

EOU   « 

0IP3 

03 

INH    A 

OSPI 

OA 

iUAX    p 

OBM 

1  lOAon 

1 

RPLIMB4 

LNI    Df](} 

ixio   ni'Ni>) 

*iB7 

» 

COU    » 

&iB7 

3D 

DCH   A 

OiBB 

FftBFOB 

JM   n  RIO  ADS 

Ot»P 

IV 

PAP    D 

af9C 

Cl»70fr 

Jfll>    RBLDAD'I 

OIBf 

« 

EOU    » 

0»if 

03 

IM)C   t 

OVCO 

tM 

LPAir  i 

rirt    fO«lESi 

«iCl 

V7 

0«A    A 

»53«ULB   PC   0   OR   S   KHZ 

MCt 

C^CMi 

JH?    BBLDAira* 

0BC5    3C20 

HUT    AfST'ArC 

fIS   Or    TH^ERT   SPEECH   SPACE 

O&C?    02 

STAX    B 

PBCa    C 3 BOOB 

1 

JHP    RBL0AD4 

OBCt   * 

R»L0*ti9A  EOU   t 

OBCF   FEO* 

CPl    s 

MO)   CO 

ll«T 

II»fVALIP  FREO 

«»Ct   5F 

m}^   E*ft 

»AM   0«S 

CBCF    19 

I 

BAP    D 

oeiw  ' 

EDU    « 

eK»  na:»s 

LICI    B*A]0 

tAtJiFST 

OBQS    fV 

BAB    D 

0B&4    liriFF 

LXI    B»-15 

mt-o-s9V9,-  H4fl,TjFn  or  5 

ow^  rs 

ftlSW   B 

lim  frivtPE  BY  15 

OB!M   OAOO 

RBI.DAP7 

mil    B*& 

OVBA   ' 

Emi  « 

OSDA    IV 

DAP  B 

IKEEP    fiUBTRACTIHG    UMtli    DdMC 

OBBB   04 

IWR  B 

OBDC    7C 

HOV  AiH 

ikFOflllue*    IF    TEfi   ERI*Off 

&PfIl   0? 

RLI! 

*     (WQT    HIJLTIPLE    OF     IS    fcM?! 

CEDE    I3AE50B 

Jt    RBLDADB 

ORE]    fl3 

OPvfl    L 

*«R'Q+    IF   YES   PONE'  ■  « 

OBE?   C^OAOB 

1 

itiioApe 

JH7    RBLDAir/ 

0BE5   = 

EDU   t 

OBES   SO 

ttm  £*a 

JUAUlfF    ru   <30    TO    1C22    tH   E 

0BE6   CI 

POF"  e 

0BE7  ea 

RC 

tHrtUf^H    IF    NEG     (ERROR -HPT    HULT    DF 

15 

QBES   03 

JHK    8 

^K9  OA 

LBflX   B 

lOET    OFFSET^    l^-AOOt:?^Sl)«^LCXr I^idQO 

OKA  FEOl 

CFI    1 

l-44>0   hHZT 

OPTC:  C2FB0I 

.MtZ  RBLOACi? 

OKF   JE^O 

mti  A»HiMiis 

IIAV    'HIMtlS* 

OlFl   OS 

STIUt   B 

0IF:2   71 

nOV  AtE 

nm»   PRiKnHAM  »tf  iq>fiZ   LOUCi 

0»F3   6A2^ 

^t    40 

QVFS  5F 

HDV  EiA 

0«FA    lAOF 

iwi  Wtmi  Ren^*  isit  oupleie  a 

OBFS   CJIMC 

iriti^BT 

^MF-   GpTllCIL 

OBFR   = 

E0U    • 

OIW^F    FEO? 

CPI    2 

«SI*IPLEIfT 

OBFB   C?&90C 

Mjr    RpLOAfftO 

fiCOO    IES3 

nvi    A.    1' 

iSAT    'S',    SlnPtFC 

«C«2   «? 

ST  AM    i 

0C03    16FF 

NVT   SFNOt    ft 

«C4S   C31O0C 

i 

J^    ttftTALh 

ocoa  =^ 

RPtOAIitO  EQU   « 

OCOe    FC03 

CPI    3 

l+AOfJ    hH^^ 

OCOft   CO 

l»lfZ 

)INVAt-I[)    IF    HDt 

OCOS   3E2B 

HVI    A f PLUS 

iRAY      flUiri-    DUPLE^N   B 

OCOD   02 

STAX    S 

OCOE   lAEF 

1 

flUI    D*N[1T   RBtlUPB 

acio  * 

rou  • 

OCIO   BBlB 

IN   AliB2 

OCi?  F630 

EJRi    RBBUPA   cm 

frfPUPP 

0C14    A2 

AHA  B 

I8ET    BUP|.EJtySll*|  fit   l«*e€    Of     IC33 

OCIS    P31B 

OUT  AMB3 

0Ct7   71 

IMIU  AiE 

OCIB   !!r 

CHA 

OCl*    3::!002H 

3TA    1C22FRE[I 

llMirE   FREH   Tdl    IC2S 

ecif:  3At3to 

UH-B   TCi«P*1P 

laftie  IHI.I  fnitiTrB 

OClf  C33U3 

JHP   TMJlft 

*SAT  fCli  FItCOIlf  fICir   (W   RAP  10 

gram    the    frequency    and 
transmitter  offset. 

The  interface  signals  to 
the  IC-22S  include  transmit 
and  receive  audio,  push-to- 


talk,  receive  carrier-oper- 
ated switch,  eight  syn- 
thesizer frequency  control 
lines,  plus  DUPLEX  A  and 
DUPLEX    B    control    lines. 


The  interface  circuits  sim- 
ply convert  the  S-volt  logic 
levels  of  the  microcom- 
puter to  the  CMOS  logic 
levels   of   the   IC-22S.   The 


Output  port 


LS^* 


dO 


m  ■ 


Dl 


ft2  • — -# 


L5t« 


D£ 


D3  * 


L^Zfi 


03 


D4  * 


LS26 


D4 


03  * 


ffl  « 


LS26 


D5 


LS^fi 


ai 


ft?   • 


07 


T  RAN  SMITTEN 
ON    » 


*I3¥ 


10  H 


-!        t_J 


COS  « 


OtS'C 


OLff  A 


JOfifiB 


OLiP  A 

« 


T~  LsseV- 


I  Ok 


&UP  fi 


40GGB 


» c  sa  5 

6UP  P 


4p 


406  66    — 


lOM 


•  13V 


/tJ 


•I3¥ 


«IHCROC0«f>UTEX  tm 
OtlCR5  IC  ZZS    SIOAIALS 
4a«6  VDPi  *  H  3  V.  VS5  *  <»M|} 

PULLDtTWM   RCSI$TCM»  IN  IC  22^ 
i;HAJieEO  T{3  PULLUP   RESISTOliS 
fTO<4vl 

SIMPLEX /DUPLEX   SlUtTCH 
tfEPT  m  SlItPLEX 


•3¥ 


Z2»F 


fig.  3.  IC-22S  remote^base  hardware  interface  to  microcomputer.  This  hardware  replaces 
the  diode  programming  board.  Note:  R37  common  taken  to  +5  V,  R36  taken  to  +5V,  and 

dp  resistor  restored  to  pull-down. 

jfl    142     73  Magazine  •  December,  1930 


pull-down  resistors  in  the 
IC-22S  are  made  pufl-up  re- 
sistors so  that  the  open  col- 
lector buffers  can  function 
properly,  The  IC-22S  sim- 
plex/duplex switch  must  be 
kept  in  the  simplex  posi- 
tion. The  circuit  was  built 
on  a  small  board  which 
plugs  in  directly,  replacing 
the  diode  matrix  board, 
Icom's  molex**  connector 
option  mounts  on  the  back 
to  carry  the  signals. 

The  software  listing  is 
provided  of  the  routine 
which  programs  the  syn- 
thesizer's frequency  and 
offset  The  routine  is  ex- 
ecuted by  the  foreground  in 
response  to  detection  of  a 
remote-base  frequency-pro- 
gramming command  when 
the  remote  base  is  on.  The 
command  code  consists  of: 
(least    significant    MHz), 

n00skHzU10skHz),(0or5 
kHz),  and  D  for  -600-kHz 
offset  2  for  simplex,  3  for 
+  600-kH2  offset).  For  ex- 
ample, the  146J4/.94  pair 
may  be  selected  by  keying 


220 
flCVR 


TOUCH  TONE  > 

smoBE 


*  l*OLTSTT«ENC 
^DIGITAL  €AOUN0' 
^ANALOG  en  DUN  D 


Fig.  4,  Audio  delay  line  schematic.  Audio  output  is  delayed  50  m$  from  the  input  with  squelch  tails  and  touchtone 
chopped  off. 


in  touchtone  command 
69401,  The  routine  listed 
decomposes  the  command 
stored  in  the  key  buffer  in 
RAM  and  programs  the  fre- 
quency synthesizer.  The 
frequency  then  is  read  back 
by  the  speech  synthesizer. 

Sequence  Detector 

The  sequence  detector  is 
a  foreground  task  routine. 
Its  task-pending  bit  is  set  by 
the  timeout  of  the  "220  on- 
ly beep  timer,"  so  the  task 
routine  executes  after  every 
220  transmission.  Usually, 
the  sequence  detector  finds 
an  empty  buffer  and  simply 
cleans  up  and  returns  to  the 
foreground  nucfeus.  If 
touchtone  data  keys  have 
been  placed  in  the  key  buf- 
fer by  the  TRAP  input  rou- 
tine, meaning  that  com- 
mands have  been  sent,  the 
sequence  detector  analyz- 
es   the    command   and,    if 


valid,  branches  the  pro- 
gram to  the  appropriate 
command  routine. 

A  listing  of  a  stripped- 
down  sequence  detector 
program  is  shown  in  Table 
4.  Since  the  #  key  can  be 
used  as  a  ''clear"  to  cancel 
previous  keys  during  a 
transmission,  the  routine 
scans  down  from  the  top  of 
the  used  part  of  the  buffer 
to  either  the  bottom  of  the 
buffer  or  to  a  #  key  —which- 
ever is  found  first.  That 
point  is  the  start  of  the  com- 
mand to  be  recognized. 

The  sequence  detector  is 
table  driven  — command 
routine  addresses  are 
stored  in  tables  and  are  re- 
trieved by  the  sequence  de^ 
tector  to  determine  the 
branch  location. 

The  first  branch  is  based 
on  the  number  of  keys  in 
the  sequence  — much  infor- 
mation on  the  meaning  of 


the  command  is  provided 
by  its  length.  For  example, 
the  remote-base  frequency- 
change  command  may  be 
the  only  valid  five-digit 
command.  The  program 
can  branch  immediately  to 
the  remote-base  frequency 
change  routine  to  evaluate 
and  act  upon  the  com- 
mand. 

When  the  number  of 
keys  in  the  command  does 
not  uniquely  identify  the 
command,  further  process- 
ing occurs.  If  single-digit 
commands  are  used,  the 
key  value  can  be  used  to 
find  its  routine  address  in 
the  ONETAB  address  table. 
For  multiple-digit  com- 
mands, a  routine  (COMP- 
5EQ)  compares  each  digit 
of  the  command  up  to  the 
last  digit  to  a  valid  string 
stored  in  the  program.  If  the 
command  sequence  is  val- 
id,   one   of   ten   command 


routines  is  branched  to 
based  on  the  last  digit  of 
the  command. 

This  approach  to  se- 
quence detection  is  ex- 
tremely flexible,  easily 
changed,  and  is  expand- 
able. Special  cases  also  can 
be  handled  easily  outside 
the  table-driven  structure. 


Audio  Delay  Line 

The  loudness  and  dura- 
tion of  the  squelch  tail  in 
FM  receivers  varies,  but 
some  "chunk"  exists  in  vir- 
tually all  of  them.  Circuitry 
was  built  which  eliminates 
the  squelch  tail  and  also 
allows  total  muting  of 
touchtone  command  sig- 
nals. By  delaying  the  re- 
ceived audio  on  the  way  to 
the  transmitter,  squelch 
tails  and  touchtone  can  be 
headed  off  at  the  pass,  be- 
fore they  go  out  the  trans- 
mitter.   The    delay    im- 

73  Magazine  •  December,  19S0    143  !^ 


Table  4.  Sequence  detector  foreground  task.  Stripped  down 
skeleton  of  version  used  in  repeater  controller, 

^nCQUEMCE    nCTrCTOn    rOREE'RDUHn    rout  ike.       [iCCODeS    9E0UENCF 
UN    KEt    fiUFFFJi'   AHU    JlRAr^CIHES   ^ROBRAH    EXECUHOM   Af^r^ROF'Prf  AtELT , 
t*   EFFECTIVELT   CLEARS   PF^EVlCJUS   tiCYS   FRtlH   BUfFER   UHEH 

ifiFMhtNG  A  dfdur.Hce. 

P 


ftBOO    * 

FIPTTMO 
1 

EdU    1 

OB&O   ?fCKKH) 

LXt    H*0 

FO^MI    tlrTER81SIT   TinE» 

0003    ^^710 

aiL8  LacimrT 

r  TO  ittMiPit  rtHCout  ROjrtitf 

0M«  ^«t 

IfVT    A«t 

ttMMb   C;iLIIS£    K£T   MFfER 

(M9«   X7Mt9 

ST*   HpHC 

99m   Jyh04|« 

LOA  KaPOIMT 

Ut   IWrER   Cl^TTf    4KET    PUmn    FOIMttltl 

MK   47 

nOl'   PiA 

IS4MPE 

OHT   *t 

ORA   A 

OSIO  C*4FDa 

JZ    FIMSCa 

iiF  rta  ouiT 

0013  jAjmo 

tOA   FT1W.a 

IPWW«t   OR   RAP  10   COHPiANPT 

OBI  A  or 

RKC 

OBI  7  nr 

RRC 

oBiB  tiA?:^oa 

JC   FfTTBCai 

oei>  t>»i9 

IN   PPDRT 

t^HOHE  cnnnftHb 

OS ID    £440 

A#£    f  181^18 

f TOUCH   TO«E    SftLL    PRESEUTT 

Ofllf    C2lkOB 

1 

JW2   «-4 

ILDO^    UMTtL   €m   OF    TONE 

I^R?   * 

rrTt«i»i  Eou  f 

tM»  n^^ia 

LMt   Kt«£irlljr 

0Q33  isa 

#»U  Ei'l 

M3*    1A«4 

mit  n»» 

«ttn  if 

PAIi  i 

l4lC»->  tup  Of    FtLLCII  tUFTtn   #i 

M29    34FF 

init   n.«FFH 

l5tl;J«Ff    iiM    TALlh/fiTAL     1LWrtlf**Tfl* 

OeZV   43 

HDU   1*L 

ICN-D  CF    SUFFER 

0821:  • 

1 

BEtIt 

EDU   f 

0821:  2r 

OCX   H 

ftiC^N    [lOyH    FROH    TOP    TO    i 

0820  ru 

nov   ArL 

r         EJH    BOX  T  OH   OF    flUFFEl? 

08ZE   FCS8 

CPt    L1W  KEYBUF- 

■1 

0030  pufoa 

JZ   flfia? 

Ce33    7E 

MOW   A»M 

0934   FC«C 

cpx  urm^ft* 

0«»  UiJW» 

1 

Ki9 

J*fZ    SCBl 

oftsf  > 

£Wi  « 

«3T   2J 

IMX    H 

lfHI.»->ril^T   WAtfP  CHAR 

Oe3A  FEFF 

CPt   8FFII 

tUAf   OMUT   K^V   A    •* 

0831;   f:2400B 

jHz  seoi 

0B3F    28 

1 

SE[13 

PCK  H 

If^QIHT    TO    «    IF    TCS 

[ja4o  - 

EOU   « 

0^40   7a 

HOM   Ai» 

0841    f3 

SUi   L 

lAwNllHBER    OF    KETIS 

0842   FCOi 

CPt    11 

ICMECK    FOR   OUCRrLOy 

0S44    D24F«8 

JMC   FINSCtI 

0S47  fa 

PUSH   H 

iJUn^    TO    BUMCH    TAiLE    EltTftY    LDUTtCM 

084«   ?|A4«« 

LXI   H#lliLTA8 

I         MSEP   DK  lMf8CM    OF    «Et5 

«««•   C 341 31 

FIHSCOP 

_Br   JI9TAV 

HMf   l*>->f^lMf   t/AtlP  CiMikp    S^i^BPOlJi! 

084C   - 

ESU    8 

0«4E   El 

f 

FlNscg 

PW  M 

M4F   - 

Eftti   « 

0fl4F   L'Ddlll 

CALL    tTOt'Ew 

lOPEM   TlMfCt4T0#(    kfY    BUFFER*    FTC. 

OB152   AF 

XRA   A 

«83J  j:,^3Iiio 

ST A   PTT9E5 

JCIFAR    PENDINQ    HIT 

m^A    37 

4 

8TC 

IRE  SYNC    FDRE&RtlUNP    TO  BKONH 

««$7   ■• 

• 

oas^  CI 

f^fSf  H 

o«»  c* 

■ 

W£1 

o«sv  • 

1 

MSff  £1 

■< 

POP    H 

0<»«   • 

iMilPSCIt  CPU   « 

iMKfft   ?ITC31 

Lxi  Hi^nmti 

#Atn(H0UL£08C   VALfD  SEfMJCNCE 

OB^D    3A3D10 

LtA   PtISED 

4      MITri   SPEECH    *SAY    -HARK'* 

0B40   OF 

Rite 

t  PHONE    OR   RAP  in   rOHHAHD-^ 

O&ii    OF 

KMU 

Oed2    PA490« 

4Z    UAl,IDQEDR 

On^S  tD473^ 

CALL    TftLflP 
JMPF  I**B£0 

»TM.K    PH   FNONI 

<»A8IC7 

1 

Vinous 

RST    4 

Mid9    - 

LOM  EOU   « 

M*V  C»»33 

CALL    TMJcft 
JHPrtHSCO 

1      QH   RABID 

WACtfT 

PST    * 

IDCtrOE   ON    TYPE    Of    SEOUEHIIrE    tABEl}  ON    hMfflMfR   OF   CHAR8 
I 

I  ONE  NCT  cannANp 
I 


plemented  was  50  ms,  al- 
lowing the  audio  to  be 
muted  gently  just  prior  to 
the  squelch  tail  or  touch- 
tone  reaching  the  transmit- 
ter. 

Audio  delays  can  be  im- 
plemented with  bucket-bri- 
gade devices  — particularly 
short  delays  — but  the  ap- 
proach used  here  for  the 
relatively  long  delay  was  an 
Intel  Codec  chip  plus  digi- 
tal shift  registers.  The 
Codec  is  a  complete  two- 
way  data  acquisition  sys- 
tem, primarily  intended  for 
use  in  telephone  equip- 
ment. It  converts  an  incom- 


ing  audio  signal  to  a  digital 
bit  stream,  and  an  incoming 
bit  stream  to  an  audio  out- 
put signal,  for  a  two-way 
pulse  code  modulation  sys- 
tem. As  used  here,  however, 
the  digital  bit  stream  is 
simply  delayed  through  the 
shift  registers  and  returned 
to  the  Codec.  The  audio 
output  is  therefore  a 
delayed  version  of  the 
audio  input.  Any  delay 
length  can  be  accom- 
plished by  selection  of  the 
size  of  the  shift  register,  but 
five  1024-by-1  shift  registers 
used  here  provide  the  de- 
sired 50^ ms  delay. 


flftAfl' 

tMCOfC 

EOU    • 

0MB 

Et 

POT  H 

ii«8.>*>Fi8aT  VM.18  ayM 

OME 

7i 

IBV  A»M 

i8Ct  KtY   VALUt 

OSAF 

2tPfr08 

LXI   H*0ICT*8 

tTA8LE    OF   ROtrTlME  ASOBESSEft 

087? 

C34131 

, 

JHP    J4rTA8 

iCOliPUlE   MimtSB   mm  so   TMEfft 

1 

I£10HT   KEY    CEhnnANO 

P 

EID^TbEC:   EQU   t 

067* 

■ 

oe/S 

El 

POP   H 

MHLI-VFIRBT   VAUP   CHAR 

087A 

1114«4 

LXI   B^L^EOl 

iYEST    FDR   FIRI^T    POSSIBLE    SEOUEHCE 

88  7f 

cosiofl 

I»LL   COHPIED 

»DONY    f»EY4JfMI    IF    UALIO 

*«VL 

illAO? 

LKl    D»L5£0? 

t^^H   SECOMDr   OC 

«7F 

C8880B 

CALL    CDMrSCO 

OM2 

113408 

LJtl    B^LSEBl 
CALL    COHPSCO 

ONI 

CS4F8a 

1 

COlfPSEO 

J»F  FIMBEO 

tnUST    m    tMVHLlO 

0808 

« 

EJ»t»   i 

0888 

E9 

1 

FUBH  H 

I8<^JC   SYRIHG  LOCATION 

OSSQ 

M 

CDNPSEOI    EC7U   t 

oaac 

lA 

LDAK    D 

IDET    EXPECTED   ^AUUE 

<?98D 

BE 

CHP   H 

ICDHFARE    TO   UALUE    tH    BUFFER 

CIS8E 

C2370e 

JHZ  F(m:{3fiPSEa 

tRETURM    IF    P{FFER£NT 

0^1 

23 

INX   H 

IDTHERlilSE   NEIIT 

CWV3 

t^ 

IN^X   D 

08^3 

1* 

UMX   8 

ILAST    CMAR    I**  fllOUCWCf 

08T4 

87 

ORA  A 

08*9 

rz8co« 

JT  c»«*>;(ai 

o«te 

E* 

utam 

lYFS*    mm   OCT   BAAMCH    TABLE    AD88E5S 

vm9 

tA 

UNUf   8 

lA^AST   81  Bit   V    $ta 

OB?A 

?3 

I  HI    H 

OWp 

^ 

mrv  E*n 

0B9C 

a 

lant  H 

0890 

5A 

ROM    Dffl 

IQCT    ABORESa   FffOW   TABLE 

oe?E 

EB 

XCHD 

iima  HL 

0B5?F 

01 

FOP    U 

08A0 

M 

POP  c 

IRE  STORE   STACh    POINTER 

OSAI 

C34131 

JWP   JI*PTftB 

ItOWtlTE   ROUTINE    RDDftES^  A/ID    JUHP    THERE 

1 
tJIRAMCH 

TA8LE    ftASEP  ON 

NUHMR   Of    *E¥S   IN   BUFFER 

0884 

A 

KtLTA8 

EDU   t 

I  AT    ROUTIlCt    tPOr  RP1->FIRST   CHM 

OPM 

mm 

DU   FlffSfOr 

iO    UtSp    tiWALl»  EMTRT 

OOAX 

8808 

8u  ammc 

11    RXTp    OECtElE 

08A8 

4E0a 

DM   FIHVtOr 

12    KEYSp    JtHVALtO 

«^BAA 

«E08 

pli   FIMSEOP 

13   RtYS,    IMVAilP 

08M: 

4E08 

DU  FINSEOF 

14    KEYSi     INVALID 

»QilC 

3108 

[l«»  RBLDAtiP 

1^  HEYS^    NAY    8C   REHOTE   8A&E    Ft£8  LMS 

08B8 

4E88 

DU  FtNSCOP 

lAi    [NVALIB 

089^? 

4FQB 

DU   FIMSEOP 

j7p    iwuftuir 

oeB4 

7S&e 

DU   EIQKTDEC 

4Bf    DECIPE 

08»A 

^EW 

Dy    FINBEflP 

*9ii     INVALID 

0888 

4E0B 

1 

oy  FiNHtap 

tlOf     1P*WALEP 

TA9LE    FOR   &(£ 

E^ITRY   BUFFER 

MM 

• 

OffETA» 

EOU  * 

U0S8A 

i>efl« 

BH  KCYO 

»« 

U098C 

vwuv 

Oy  llETI 

il 

UOfliC 

ooe« 

OH  ftEV2 

fX 

U08CO 

0080 

DU  HEY} 

19 

liO«C3 

0008 

Ml   HEt4 

14 

U&&E4 

0800 

BU   KEYS 

n 

ut^ttca 

8000 

Ml  KEYfr 

18 

UOBCB 

0000 

DU   KEY7 

17 

UOBCA 

0008 

W   ICEVO 

#8 

uoecc 

(5000 

DU  KEYf 

if 

08CC 

4F08 

DU   FIHBEO 

tfiLANiO 

UOBDO 

0000 

DU   KEYS TAR 

fi 

U08D2 

00^4 

1 

oy  KETP0UN8 

li 

i%:ij*rv,7x  nuiCM  ta8le 

8884 

■P' 

n73TA8   EQU   « 

08P4 

4F08 

SH   FINKO 

$9 

8«&A 

4F08 

DM  FIHSCO 

n 

^BIB 

4F08 

W  FIHSEO 

la 

oeDA 

4f08 

W  FSftSEO 

II 

OB&C 

740f 

DW  €8(8 

Pi 

080E 

^8fl 

tm   VOtCEIS 

fS 

OfiF$ 

1031 

Dy    AUTOPATPHOh 

tA 

0BE2 

4FCD 

oy   ftBAUVRON 

17 

08r4 

7F0I) 

oy   FtBRCIJROFF 

*t 

08EA 

4rai 

1 

DM   Flf^eEO 

l» 

KttlEflCES    '    F1»5T    7  OF   «  OF   COWIAHl^  CODE 

■ 

mtMUCH    TfLfiLE    Al3|]«£S8 

OVIO 

8lO:!O3O48!USt:0i: 

OS    lr?i3r4»S«**7teFF44 

Of  18 

IM8B 

DU    Tt2:}tAt 

0¥]A 

QTf3^6ii%0*QJL^mi 

DB   7#A»9*4t3t^fI>0Frif 

lt0922 

0<M>0 

Olt  t74SYAi 

8*24 

0:-03040SOAL^01l 

DB  ri3i4i5«4i 

^tBiOFFH 

U05i?C 

0000 

mi  T234rA8 

Audio  Mixers 

The  various  audio 
sources  in  the  repeater  are 
connected  to  the  220  trans- 
mitter and  to  the  phone  line 
under  computer  control, 
AUDI  and  AUD2  output 
ports  select  one  or  more 
audio  sources  to  be  en- 
abled into  the  two  mixers. 
The  audio  switching  is  solid 
state  and  is  quite  simple 
considering  that  there  is  no 
detectable  click  or  pop 
when  switched  and  no  de- 
tectable feedthrough  in  an 
open  switch,  4053 B  single- 
pole,  double-throw  CMOS 
analog  switches  are  used. 


When  the  audio  switch  is 
open,  the  output  is  shunted 
to  ground  to  eliminate  any 
signal  feedthrough.  Good 
grounding  and  isolation  of 
the  CMOS  switch  power 
supply  from  the  computer 
logic  are  important  to  keep 
out  noise*  The  low-power 
Schottky  control  tine  buf* 
fers  ensure  clean  logic 
levels  to  the  CMOS,  even  in 
the  presence  of  possible 
crosstalk  on  an  intercon- 
nect cable. 

Repeater  Performance 

No  significant  problems 
were  encountered  in  bring- 


M 


144     73  MagazinB  •  December,  1980 


SOURCE 


■  ■»^n^- 


LEVEL ;r 


J 


#1  ^ 


ENABLED 


AUDfO 


^rfW^ 


LEVEL 


;i 


^7? 


/TT 


«.£K 


r 


40  £30 


CDM 


ICi 


ENABLE  V 
#2  ^ 


LS04 


lOK 


T 

^ 


DO  I 


lOK 


*3V 

A 


LSa4 


l> 


'ENABLED" 


AUblO 
SOURCE  > 


-■^wv 


LEVELS* 


/?5 


ENABLE 

#  n 


'ENABLED' 


F/g.  S,  Audio  mixer  schematic.  Repeater  contains  one  eight- 
input  and  one  four-input  mixer. 


ing  up  the  control  system. 
We  were  concerned  about 
rf  interference  from  the 
computer's  high-speed  digi- 
tal logic,  but  since  the  220 
receiver  is  very  well  shield- 
ed, there  were  no  problems. 
The  fC-22S  remote  base  re- 
quired feedthrough  capaci- 
tors to  be  placed  on  all  con- 
trol lines  leaving  the  repeat- 
er cabinet  to  keep  rf  off  cer- 
tain  two-meter  frequencies. 
RF!  is  something  to  be  con- 
cerned about,  but  it  isn't 
necessarily  a  serious  prob- 
lem. 

When  the  repeater  went 
back  on  the  hilltop  with 
the  new  controller,  it 
worked  very  well.  Some 
minor  software  changes 
were  made  after  eight 
weeks  — the  ROMs  were 
simply  changed. 

There  was  one  failure  in 
the  system,  occurring  after 
eleven  weeks.  The  three- 
terminal  regulator  on  the 
computer  board  became  in- 


termittent— probably  a 
high  resistance  internal 
bond,  definitely  not  ther- 
mal shutdown.  The  com- 
puter's supply  voltage  oc- 
casionally   dropped    low 


enough    to    alter    memory 

contents,  but  not  always 
low  enough  to  reset  the 
CPU.  The  machine  would 
occasionally  clear  itself 
and  sometimes  turn  itself 
off  (clear  the  TTOR 
Repeater  Enabled  bit).  A 
new  regulator  solved  the 
problem  immediately;  it 
was  back  to  its  old  self  and 
has  performed  flawlessly 
ever  since. 

Conclusion 

The  design  and  construc- 
tion of  the  control  system 
was  a  six-month  part-time 
effort  by  two  people.  That's 

a  lot  of  work,  but  from  my 
viewpoint  it  was  well  worth 
it.  Use  of  the  computer  in 
the  controller  allowed 
building  in  really  useful 
features  that  would  not 
have  been  possible  without 
it.  The  software  intensive 
approach  was  extremely 
educational  and  is  the  only 


practical  approach  for  a 
system  of  this  complexity. 
The  project  was  the  most 
satisfying  microcomputer 
project  I've  been  involved 
in, 

Sincerest  thanks  go  to 
Bruce  Martin  WA6EQS  who 
shared  half  the  work  of  this 
project.  Bruce  is  the  father 
of  the  three-year  old  repeat- 
er and  had  many  of  the 
ideas  for  features  and  their 
implementation  in  the  new 
control  system. 

Don  Pezzolo  K60ZH 
contributed  to  the  project 
as  a  resource  for  bouncing 
ideas  back  and  forth 
throughout  the  develop- 
ment. His  continuing  en- 
couragement throughout 
the  project  was  a  big  factor 
in  its  successful  comple- 
tion. Don  also  manages  the 
repeater  site  and  keeps  the 
machine  happy  in  its  home. 

Behind  the  repeater  is  the 
rf  expert  Werner  Vavken 
WB6RAW,  who,  with 
WA6EQS  and  Ray  Max- 
field  WA6VAB,  is  respon- 
sible for  the  rf  portion  of 
the  machine.  Bill  Melody 
WA6YBD  installed  and 
maintains  the  antenna 
systems. 

Parts  and  equipment 
were  contributed  by 
WA6EQS,  W6LVY.  W6YJL, 
WA6VAB,  and  WB6WDP  ■ 


Standard 

ASCII 

zero 

forty 

dollars 

space 

sh 

J 

one 

fifty 

cents 

X'point 

seven 

K 

two 

sixty 

pounds 

quote 

eight 

L 

three 

seventy 

ounces 

numtjer 

nine 

M 

four 

eighty 

total 

dollars 

colon 

N 

five 

ninety 

please 

percent 

semicolon 

0 

six 

hundred 

feet 

and 

less  than 

P 

seven 

thousand 

meters 

apostrophe 

equals 

q 

eight 

plus 

centimeters 

left  paren 

greater  than 

R 

nine 

minus 

volts 

right  paren 

mark 

s 

ten 

limes 

ohms 

star 

at 

T 

eleven 

over 

amps 

plus 

A 

U 

twelve 

equals 

hertz 

comma 

B 

V 

thirteen 

point 

DC 

minus 

C 

W 

fourteen 

overflow 

AC 

point 

D 

X 

fifteen 

clear 

down 

stash 

E 

Y 

sixteen 

percent 

up 

zero 

F 

Z 

seventeen 

and 

go 

one 

G 

lowercase 

eighteen 

seconds 

stop 

two 

H 

tone 

nineteen 

degrees 

tone  (low) 

three 

1 

uppercase 

twenty 

tone  (high) 

four 

up  arrow 

thirty 

oh 

five 

control 

Table  5.  Telesensory  Systems  Mini  Speech  Synthesis  PC  boards  vocabulary. 

73  Magazine  •  December,  1980    145   liS 


■■■ 


Chart  of 

UNITED  STATES  AMATEUR 

RADIO  PIUVIU&CES 


by  cluss  of  Ucenst%  emission  typ*\  and  fre- 
quence from  160  thru  2  meters,  inchiding 
pmvKian  for  the  new  30, 17^  and  12  meter 
hands.  Thb  22  x  28  in.  twefv^color  chart 
k  tht"  firti  of  its  kind  to  be  both  inforniati\  c 
and  dtsrorative, 

Be  a?rtain  about  WHO  gets  to  do  WHAT, 
and  WHEBEI  Enhuiice  your  shack! 
Regular  price  $3.tMI  SPECIAL  INTRO^ 
DUCTOHY  PBICE  $2,50.  Indutk^,  post- 
age and  handlifig. 

Lamj  Denniisan — KB6KG 

5002  Marion  Avenue 
Torrance^  Calif oniia  90 SO 5 


A 


Si 


«>5;^ 


Kf 


•o 


s 


^. 


^   O  ^^^ 

"^S, 


cj^   Ci*  'f^ 


GIGA  Hz  Preampli 

UlUa-wideband 
1  MHz 

to  1000  MHz 

The  PM-5  preamp  modute 
cov&rs  the  entire  range 
froml  MHztolGHjflDOO 
MHz)  Perf^cl  (or  the  new 
GHz  coLinierA  and  higher 
UHF  bands,  the  Iremen- 
dous  bandwidlh  oif  thi^  pfesmp  makes  i1  So  ¥efS3lite 
you  wili  soon  depend  on  it  vvhenevef  addtd  gairi  is 
rwedad  tor  RF  measuremenis  Aiso  for  scopes,  mW 
powef  meiets. detectors,  elc  G^m  is  30d8  from  i  MHz 
to  500  MHz  decreasing  to  t5  dB  ai  1  GHz.  Mftxirnum 
cHjtpuf  IS  ^  volt  (>-p  mto  50  ohms  It  is  di@^n«d  lo  work 
in  either  50  or  rs  ohm  systems  The  pfeamfi  is  r^eady  lo 
use  with  (he  power  adapt er  provided  Of  any  7^  to  15 
voit  DC  suppky  at  50  mA.  It  can  be  '  byilt  in'  or 
mounted  on  your  equipmeni  it  desired  Made  with  fine 
qtjaliiy  pialedthi'ij  ]>oards,  strip  linie  design  mssng  mi- 
crowave trans iiStors,  BNC  connectors. 
Mode(  PM-5  UHF  Preamp  {w/ power  adapter).., .,.,159.95 

SENSITIZE  YOUR  COUNTER 

lt*s  Ten  Times  Better  .  ---;'!: 

with  a  '^^^'J^ 

COUNTER  PREAMP    ^^  ;^J^ 


Wide  barvd  preamps  «ith  20  lo  30  dB  gain  Improves 
pertonTtance  ol  Jow  price  counlers  considiefably 
ProtK  reads  osciJlators  without  ioadir^g  Gcfnefalors 
can  be  set  10  lower  oulput  avoiding  trequent  shiHs, 
Also  for  scopes,  meters,  etc,  Valuable  troubleshooting 
.^id.  Powered  by  3  pencells  BNC  connectors.  Hi  Z  in- 
pul  Output  Is  200  to  400  mv  rms  into  50  ohms, 

Model  VP  2.  VHF  Courtter  Preamp 
lOOKHxto2DOMHi.. „,.,S39JS 

Model  yP  3:  UHF  Counter  Preamp, 

T  MH?  to  500  MHi  S&4J9 

Ord«  Ifom  PAjGEL  ELECIPONICS.  6742^:  Tampa 
Ave.,  Beseda.  CA  9i33&  Send  check  or  MO  1o^  ppd. 
Shipment  via  UPS  wben  a^ail  Of  call  213'342'27i4  for 
COD  Foreign  add  10*^0  for  airmail  &  tiandlin^  Calit. 
res.  add  6%  sales  tax.  One  year  warranty,  money  bactt 
§u3rar>tee.  ^  y^ 

:J5>  PAGEL  ELECTRONICS 


RTTY 

Demodulators 


$149.00  Ham  net 


FSK-1000 


T.M, 


Here  is  no  compromise  design  and  construction: 

•  Unparalleled  selectivity  achieved  with  sophis- 
ticated limiterless  design  utilizing  ultrasharp 
active  filters  and  decision  level  correction  cir- 
cuits 

•  The  most  flexible  interface  system  available  to 
computers  and  high  voltage  loops 

•  Built  in  170  volt   loop  supply 

•  Selectable  bandwidths  of  55  and  TOO  Hz.    (copies 
110  Baud  ASCII) 

•  Continuously  tunable  shift  coverage 

•  Rugged  construction  -  commercial  quality 
throughout 

•  Full  complement  of  rear  panel  connectors  for 
easy  interface 

•  Keyboard  activated  switch  for  break  in  operation 

•  Individual  tuning  meters  and  LED's  for  quick, 
accurate  tuning 


El  FSK-5 


ilt 


^^  T.M, 


$22  9.00 


Order  direct  on  Visa  or  MC 

700  Taylor  Road 
Columbus,  Ohio  43230 

T.M.    Call   (614)    864-2464 


This  RTTY  demodulator  is  designed  for  computer 
interface  but  is  a  fine  stand  alone  unit: 

•  Easy  computer  interface  with  RS'2  32  or  5  volt 
logic  signals 

•  Three  shift  coverage  without  straddfe  tuning 

•  Selectable  bandwidths  give  you  optimal  Baudot 
or  110  Baud  ASCII  copy 

•  Input  bandpass  preselector  using  active  filters 

•  High  voltage  loop  keyer  output 

•  Autostart  built  in 

•  Three  shift  AFSK   keyer  plus  narrow  shift  CW  ID 

•  Fully  wired  and  tested:     ready  to  copy! 

•  The  FSK'500  is  the  best  demodulator  available 
for  under  $500*00  (Except  for  our  FSK-1000!) 

•  Positive  tuning  with  meter  and  LED's 


146     73  Magazine  •  December,  1980 


8  0  0 


2  2   8 
4   0  9    7 


COMPARE  the  J.I.L.SX-100  Scanner  to  any  other  scanner  available  on  the  market  today. 


16  Channels 
30  54  MHZ 

1 40  1 80  M  HZ 
410514  MHZ 
Digital  Ciock 
Dale  Dtspfay 

110  V    AC  or  12  16  V. DC 
1  Year  WaTranty 
Seek  Rate:  Fast  lOch/sec 
Siow  5  ch/sec 


BRIGHT  GREEN  9  D»G!T 
FREQUENCY  DISPLAY 

Ext.  Antf^nna  Jack 
Ext.  Speaker  Jack 

Large  Top  Mounted  SfJeaki-r 
Mobile  Mounting  Bracket 
Scan  Rale:    Fast  8  ch/sec 

Slow  4  ch/sec 
Scan  delay  Time   variable  0  4  st^c 


Now  you  can  see  why  it  is  our  best  selling  scanner  at  only  $199,95 

HURRY!  Supply  is  limited^ 


Kenwood  TR-7800 

15  multi-function  memory  channels 

Extended  frequency  coverage  143.900  148.995  mhz 

Front  panel  keyboard  and  internal  battery 

backup  for  all  memories 
Priorty  alert 
Auto  scan  and  up/down  manual  scan 

Digital  readout  of  both  transmit  and 
receive  frequency 


Panasonic  RF-4900 
on  sale  this  month. 

List  S549,95 

Sale  price  this  month 
$369,95 


Yaesu  FT  207R 

800  channels  across  144-148  mhz 
Up/down  scan  feature 
4  memories  plus  priority  channel 
Keyboard  entry  of  frequencies 
RF  output  2.5w  or  200  mw 

Call  for  Special  Price 
Today! 


HELLO  WORLD!. „You  get  it  all  with  the  I  COM  720!!! 


All  9  bands  and  solid  state 

DtgitaUy  synthesized  tuning 

Two  VFO's 

RF  Speech  Processor 

General  Coverage  Receiver  0.1  to  30  mhz 

AM,  CW,  SSB,  and  RTTY  modes 


Kenwood  TS-520SE 

Cents-ability  in  a  quaNty  HF  Transceiver 
Features:  Coverage  160-10  meters 

CW  wide-narrow  switch 
RIT  control 
Eight-pole   crystal  filter 


1^14 


VISA* 


We  Export 

PRICES  SUBJECT  TO  CHANGE  AND  AVAILABILITY 

Communications  Center 

1840  "O"  STREET    LINCOLN,  NEBRASKA  68508 

In  Nebraska  Call  402/476-7331 


MosterCord 


•^  Reader  Servtce — see  pags  226 


73  Magazine  •  December,  1980    147 


Make  a  Microcomputerist  Smile 


build  him  this  EPROM  eraser 


Herbert  M.  Rosenthal  AL7C 
2941  BTEndywine 
Anchorage  AK  99502 


One  of  my  friends,  who 
is  deep  into  the  home- 
computer  hobby,  had  a  dif- 
ficult time  locating  an 
eraser  for  his  2716  EPROM. 
He  finally  located  one  that 
was  built  into  a  plastic  tape- 
cartridge  storage  box  and  it 
worked  fine.  A  quick  look 
inside  the  box  revealed  that 
the  manufacturer  simply 
epoxied  a  pair  of  sockets  to 
the  edges  of  the  box,  bolted 


a  small  fluorescent  ballast 

to  it,  drilled  a  hole  for  the 
line  cord,  and  included  the 
usual  4-wire  fluorescent 
starter  switch.  El  Cheapo  at 
its  best  but  we  wondered 
about  the  safety  of  the 
device  as  we  had  heard  of 
the  potential  injury  to  eyes 
and  skin  from  exposure  to 
ultraviolet  [UV)  rays.  The 
tube  used  in  the  device  was 
a  Sylvania  G8T5  — remem- 
ber this,  as  it's  important 

The  next  EPROM  eraser 
we  saw  was  built  by  som^ 
one  with  a  much  better  con- 
cept. It  had  an  all-fnetal 
case  with  a  drawer  that  held 


Tube:  G8T5 
Nominal  Watts:  8 
Nominal  length:  12" 
Tube  diameter:  5/8" 
Approx.  lamp  Amps:  0J60 
Approx.  hours  of  life;  7500 
Effective  UV  length:  8 Va" 

UV  oytpyl  ®  2537  angstroms  at  100  hours.  Watts:  1,3 
Average  UV  output  through  life:  0.98  Watts 
Max.  intansity  perpendicular  to  bare  tube: 
Watts/Square  Foot  at: 
1  ft— 0.14 

4"— 0.86 
2"— 0J5 

These  are  averages  at  100  hours  life;  initial  ratings  about  20% 
higher,  decreasing  to  an  average  of  0.75  ratings  above,  through  life. 

Fig.  1.  Useful  dat3  if  you  *'roll  your  own/'  Source:  General 
Electric  TP-122,  Large  Lamp  Departnrent 

Liu    148     73  Magazine  •  December,  1980 


the  EPROM  in  conductive 
foam.  The  drawer  had  to  be 
in  place  before  a  switch  was 
operated  to  complete  the 
circuit,  No  UV  leakage,  no 
unintentional  viewing  of 
UV.  This  one  also  had  a 
60-minute  timer  built  in.  It 
appears  that  the  bulb  used 
by  the  latter  device  has  a 
much  stronger  output,  for 
the  suggested  erasing  times 
were  in  the  area  of  20-30 
minutes.  The  bulb  has  a 
house  number  and  no 
doubt  is  made  by  or  for  that 
company  and  thus  would 
not  readily  be  available  to 
the  home  constructor. 

The  next  chapter  in  this 
story  comes  from  a  14-page 
General  Electric  manual, 
''Germicidal  Lamps/'  TP- 
122,  from  their  Large  Lamp 
Department,  I  obtained  a 
copy  of  this  from  the  local 
industrial  dealer  for  these 
lamps.  An  inquiry  to  them 
on  the  Syivania  number 
revealed  thatCE  and  others 
(Noreico)  also  make  this 
lamp  for  air  irradiation  and 
other  germicidal  devices. 
We  joked  about  the  UV 
bulb  in  the  electric  razor  at 
the  airport  {ten  minutes, 
two  bits) ,  ,  .  all  along  my 
friend    could    have   erased 


the  EPROM  while  he  was 
shaving!  [Also  used  at  the 
bowling  alley  to  Sterilize 
the  rental  shoes.) 

But  something  good  did 
come  of  this  pursuit. 
Whereas  the  electric  dealer 
would  order  the  bulbs  only 
in  quantities  of  24  or  more, 
we  found  that  the  local  bar- 
ber and  beauty  supply 
house  had  them  in  stock 
and  would  sell  them  at  re- 
tail for  about  ten  dollars. 
Click.  A  small  6^  to  ft-Watt 
fluorescent  tube  ballast 
and  switch  are  another  six 
or  seven  dollars;  everyone 
has  a  micros  witch  tn  his 
junk  box  for  the  absolutely 
mandatory  interlock  switch- 
Click  LM8  and  others  make 
metal  boxes;  plywood  is 
cheap;  the  tube  is  nominal- 
ly 12"  long,  and  the 
EPROM  should  end  up 
under  the  lamp,  about  1" 
from  it,  centered  along  the 
bulb,  and  impressed  in  the 
black  conductive  foam  it 
came  in.  Under  the  bulb  is 
specified  so  that  the  UV 
rays  and  not  the  heat  from 
the  bulb  work  on  the 
EPROM.  The  effective 
length  of  the  UV  radiation 
is  SVi",  so  cluster  the 
EPROMs  from  the  center  of 


the  bulb. 

Back  to  the  GE  manual. 
To  allay  any  fears  about  the 
use  of  UV  at  all,  I  quote, 
"...  Prolonged    exposures 
or  exposures  to  high  inten- 
sities of  ultraviolet  energy 
can  cause  conjunctivitis  Cin- 
flammation    of    the    outer 
membrane  of  the  eyes)  and 
a  reddening,  or  burns,  of  the 
skin.  The  glass  used  in  con- 
ventional   eyeglasses    af- 
fords  adequate  protection. 
However,    care    should    be 
taken  that  the  UV  energy 
does    not    enter    the    eyes 
from    the    side,    nor    is 
reflected  into  the  eyes  from 
the  back  side  of  the  glass. 
To  protect  the  face,  clear 
plastic    face    shields    are 
available  .  .  .  General   prac- 
tice is  to  consider  0,5  micro- 
watts per  square  centimeter 
of  2537-angstrom  energy  in 
a  7-hour  period  to  be  the 
maximum    safe    exposure 
without    protection.    An 
equivalent  amount  of  expo- 


sure will  be  obtained  from  a 
bare  30-Watt  lamp  in  one 
minute  at  18  inches  or  in 
one  hour  at  12  feet" 

Most  of  the  rest  of  the 
manual  describes  the  use  of 
the  family  of  germicidal 
lamps  — from  a  IVa"  length 
to  the  largest,  which  is  64"; 
the  lamps  are  used  in  every- 
thing from  air  cleaners  to 
meat-cooling  rooms  to 
pharmaceutical  manufac- 
turing. But  what  should  in- 
terest us  the  most  is  that  the 
spectral  response  of  these 
mercury  vapor  lamps  peaks 
at  2537  angstroms,  the  ex- 
act wavelength  called  out 
for  a//  EPROM  erasures. 

Fig.  1  is  a  compilation  of 
data  that  will  be  of  use  to 
you  if  you  choose  to  "roll 
your  own."  Fig.  2  shows 
typical  wiring  for  a  unit 
Note  in  this  latter  drawing 
that  the  fluorescent  switch, 
a  4-wire  unit,  performs  the 
function  of  on-off  and  start, 
without   a   starter.    If    this 


SPtoAL^  FLUOiiciKEttT  "4  mm.'  SwcrCH 


* 

# 

* 
t 

* 

r 

t 
/ 

b-BW  BALLAST 

1 

\                         GB  T  5                          ; 

1 

1 

I              OM-OFf 

t&A 

tii  TEH  LOCK 
WCHOSWITCM 

fig.  2.  Typical  wiring. 


switch  is  not  avaifable,  one 
could  use  two  separate 
ones,  an  SPST  on-off  switch 
and  an  SPST  normally-open 
push-^button  for  the  mo- 
mentary depress-to-start. 

It  probably  wouldn't  hurt 
to  fabricate  a  reflector 
from  soft  cardboard  and 
then  cover  it  with  shiny 
aluminum  cooking  foil. 
Place  this  a  couple  inches 
above  the  lamp;  it  can  only 
increase  the  UV  intensity  to 
the  EPROM  Provide  a 
smafi  hole  (V4"  will  do) 
covered  with  milky  white 
plastic  to  act  as  a  pilot 
lamp.    Try   a   one-hour   ex- 


posure as  a  beginning  point 
In  summary,  you  can 
have  an  ultra  EPROM  eras- 
er, violet,  for  about  $20, 
some  ingenuity,  and  a  lot  of 
fun ...  but  only  if  you 
promise  to  observe  the 
strict  cautions  from  the  CE 
manual,  which  suggests 
that  all  products  using 
germicidal  lamps  bear  a 
prominent,  highly  legible 
CAUTION  warning  that  no 
one  should  look  directly  at 
a  lighted  lamp  or  work  near 
it  without  adequate  eye 
(and  skin)  protection.  Don't 
forget  that  interlock  switch, 
be  it  on  a  Cray  or  door!  ■ 


A  rec«nL  survey  showed  that  20%  Qf  the  73  sub»rib«r5  alio  r««d 
Kilobaud  MiCROCOrtPtJTING  mag aiine  ,  .  .  and  enjoy  it.  This  li  Ihe  best  way 
lo  learn  and  keej}  up  with  tht  fapfdly  developing  world  ot  mkn>computers. 
TTKrc's  nothing  (o  be  afraid  oF«  yov  just  have  lo  read  an  Lnlereiting 
magazine  and  jrOu'M  leayrn.  Try  a  subscription  to  Kilobaud  MJCRCO^PCITHiC 
and  sec  for  yours«:tf . 
n  N*w  subscription  D  Renewal  Q  12  issues  for  S25.00 

O  Payment  enclosed  S D  24  iisuei  for  S3e.OO 

D  VISA  a  MC  O  AE     □  Bill  me    G  36  issues  for  S53.00 


Cardn 


SignatufB 
Name    . 


interbank  # 
_£xp.  0ate 


Address 
Cfty^ 


State 


Zip 


—for  even  faster  order mg  service  calf  fotf  fr^e  fSOO^  253  5473 

Canadian! :  $2?,  one  year  only,  U.S.  funds.  Other  Foreign:  30DB6 

S35,  one  year  only.  U,S.  funds.  Please  allow  6-8  week^  for 

delivery^ 


WIICROCOWPOTING  •  POB  997  •  Farmingdale  MY  11737 


TUFTS  Electronic  Department  Store.TUFTS 


PROFESSIONAL  HEADPHONES 
8i  HEADSETS 
gOOM  MIC  HEADSETS 
For   ttn   ultimjTt  in  Qjmmunicjtioni  convwiwnca  and  ffff^civncy  Ktoct  «  bootn  mic 
^lOClttl.   LonQ-lifTt«  f*wOritai  of  ptot*»iCHntl  cc«T«mMnic«t>ont,  boom  mic  t)t*dl|*tt  tllow 
im^pn  pcnorul  RufatfpTY  whilt  al«nyt  beeping  ittt  mic  vooml-i  posrtioried  fet  fitt,  ormtm 
met  trivwnis^ion.  Boom  nricrc^phonas  ttm  tcstiplawly  adiLHtibk  id  aHoat  perfect  pcvi- 
tkfenifigu  And.  twocn  hcAdses  teave  both  hfn^  fr«  to  p«Horm  ot^icr  tsiiL 
AH  m-odn  Mt*  tut>0tifld  wiih  ^'c^oie  Ulking"  rmcrophones  to  limit  ambient  notu  pickHjp 
•nd   provadt    Kuperiof    intvD'igitMhtV-    £*^    modtl   n  i  corrvcnient,  tntine  puth-fatillc 
twitch,  wfii^  c*n  be  wired  tw  eith*f  {Hifhlo  tilk  rt4iv  control  Of  mic  cifcwt  mttffupt 
fof  vpiea  opernxd  trmiitititeri.  Ttw  twitch  miy  bi  tised  «  a  marn«ntvv  pioh-button  or 
it  can  t»  locfctd  in  the  doiAm  potiiiciin.  All  madtli  hcv*  tough,  ftaxibte,  B  ^»t  cofdt  which 
art  ttrippvd  and  tinned,  un Terminated. 


/ 


N 


C-610 


C-1210 


•ff 


C-1330 


Headphone  Jack  Bom 

Ham  Ciubi,  field  day  content  optratlon. 
Nq  morv  lury  rigi  for  multiptn  haadphontf, 
Sh  Y*"  phone  i»cki  wUh  individtiil  votume 
contrail^  4  toot  cord  m  th  )&"  phona  plug. 

$14.30 


fr  ¥  \ 


w 


z:?^ 
•• 


.Ci 


CM -6  TO 


CM-1210         CM-1320         CM- 1320-5        PC- 100 


HTC-2 


HMC-2 


HTC-91 


MODEL 


Haadphcxie  Seiiiiivitv 
He*  0002  Dynet/cm? 
PTmW  input.  Ik  Hi 


limfrtion^ 
Impedance 


t^crophone 
Frequency 
Response 


I 


Microptione 

Sensltiwitv 
Briow  t  ¥olt/m4crota« 


C^iO 


103dBSPL 
*5dB 


3? 

20o^mt 


2000olifi» 


SWL^IO 


t03dB  5PL 
iSdS 


C-l^lO 


I03de  SPL 
^t3dB 


3^ 
20  ohms 


CI320 


l05dB  SPL 
iSdB 


CMeiO 


CM-1310 


I034B  SPLhOSdB  5PL 
ISdS  :!3dB 


3.2 
^  ohms 


35 

30  ohmt 


SO 

9000  Hf 


hfigh 


SIdQ 
t&dB 


JO 


CM- 1320 


105da  SPL 


3.2 
20  ohmt 


50 


HtQh 


51  dB 
±5dB 


$62.75 


I05d9  SPL 
±dB 


35 
SUfilinH 


60 
WOOUz 


CM-1320S 


35 

30  6hrM, 


50 
fiOOOH; 


t«gh 


5TdB 
+&dB 


$7555 


HigH 


51  dB 

±&de 


^9.96         fTGj& 


PC -100 


200olvrrts 


50 

1200  Hi 


Low 


HTC2 


3.2 
20  ohms 


too 

3000  H2 


Lmv 


S24.50 


HMC-2 


35 

TQahftn 


HFC91 


3.2 

20  ohm* 


100 
3000  Hj 


100 
3000  Kt 


Urm 


snM 


ttJO 


95 
95 
95 
95 


tiO 


I 


MCX3EL107 

$36S5 

5.ufK»hy,   6  Amp  MlH 


C<w1f i4ll.  cauni  jt^p  «  cjr  r Jdtb  ^  4  l^tif  7  filler 


C>Tnr>«4HHia  Citf  rn<1  |Fi«  \,  it*4l 
0Wp«i  vvtati  #«d  latdk 

tap**  t'lM  LMtfl 

Cam  J  |WI*4V   iVvbi^^^   4^Dt 


looaDwr 

I 


ttm 


MODEL  iSW 

$1935 


3  ^iTtp  Vikir 


tng  n^  wftlEi  AC  1g  tZ  uiXb, 

EK  »i3t4itv  luiFifl  lar  nusr 

iWi4Uli«rti  Ktciudmi  l-iTick  tmn  ^^m  gmm.  cm  tta\t  ine 

CHHfh  O^  ptbyvr  wiibn  poma  *fAif^ 


■ippHpiFjiilieMt 


irij 

lift 


}   4Ht.4    M»>«1. 


Unarco-Rohn 


COMPLETE  25G  TOWER  PACKAGES 
50' Guyed  Towtr:  Includes  top  section,  4  regular 

sections,  base  plate,  rotor  plate,  SO'  guy  wire,  2  guy 
assemblies  with  torque  bars,  3  concrete  guy  anchors 
and  other  miscellaneous  hardware. 

REGULAR  PRICE  $698.00 
SALE  PRICE  499.00 

SA  V£  $  199. 00 

50' Bracketed  Tower M Deludes  top  section,  4 
regulBr  sections,  bas^  plat@j  rotor  plate  and  universal 
house  bracket. 

REGULAR  PRICE  $430.00 
SALE  PRICE  299.00 

SAVE  $131.00 


fts,  02155 


TEL  1-617-391-3200 


TUFTS  ElecfronU  Department  Stor^„TUFTS 


Drake  "Dry"  Dummy  Loads— no  oil  required 


S26.95 


$53.00 


Ma^l  mo  On4i*  D 1-300 


01^1 


t^t  i 


iwH  hii  -^tk  uf  lj»ilrh  ami. 
HtM  IX   I  Ifi"  i^h  rl  ■  Q  I  imiaWt  3  Ita  li^Qfl 


5ii'.4U  err  ^iiL  LuniFiimiiii'  in  rry  Mit  H'-^iii  inw' 
I:'.  ■   lii  r    t  J  DO    1 1  r  {],  ,  ^  ]  t<i,k.  wl  F  I  Eij  HID  f« 


DRAKE  PRICE  LIST 

ArtODEL 

NUMBER   MODEL  DESCRIPTION 

COMMUNICATIOMS  ftECEWEf^S  AHD  ACCESSORIES 


f242 


T?40 


OSH'2  VLf -HF  Cgitil  Synihesa^d  SSa,  AM.  CW. 

RTTY.  IS;B  LjbOfJiory  CommiinH;#tiwH 

fi7'/DR-7      0-30  MHi  General  Coverjige,  DigJTil 


POWf  R  SUPPLIES  AND  ACCESSORIES 

1 50 1  AC^  Ponwr  Supply  for  A  -^1  ine.  1 1 0/220 V 
tS05               OC-4  T2  VDG  hswer  Supply  for  #  fin* 
ie04               PS-3  Powftr  Supply  tor  UV  3,  11 0/220 V 

1502  PS-7  Power  Supply  for  Tft-7,  1 1(1/320 V 
1S2t               FA   7  F4nfcH-PS-7^R-7/OL-tqOO 
LOW  PASS  AND  HIGH  PA5S  TVl  FILTERS 

1605  TV42LP       100W  |ja«  Pass  Filtirr 

1608  TV-330OLP  1QO0W  Low  Paa  Falier 

1^03  TV-300HP     High  Pass  Filter  for  300  Ohm  Twin  Lead 

1610  TV-7&KP       High  Pass  Filter  for  75  Ohm 


ACCESSORY  CBVSTALS 


l>YStils  fflf  2C/R4B/R4C/SW4A/ 

E  PR4  A^  L2 /T4  X8 /T4  XC/T  R4C/T  R  4CW 

Crystals  for  fixed  frequancv  opera lipn 

of  1  unable  units/2NT 

Cryffals  for  TR22/TR32C 

&YllMs  f *W  T  R  72/T  R33C 


PRICE 


$3400.00 


Synthesized  Receiver 

1449.00 

1548 

R-7/rR-7 

Cable  tntertacB  Kit 

24.50 

1&32 

f^B-7A 

NoiSA  Blanker  for  R-7 

B0.D0 

702  T 

SL-300 

300  Hf  CW  FiltEf  for  7-fim 

55.00 

7022 

SL-SOO 

5O0  Hz  CW  F.hET  for  7^!irM! 

55,00 

7023 

SL-fBOO 

IBOO  Hz  RTTV  Filtflr  far  7-lme 

55.00 

7036 

SL-4000 

4000  Hz  AM  Filter  Tor  R-7 

5fi.00 

7024 

SL-GOOO 

6000  Hz  AM  Film  for  7-llnB 

55.00 

1531 

MS- 7 

Spf^ake^  fwr  7-iline 

39.00 

1217 

4-N6 

NoiM  Blanicflr  for  R-4C 

74.00 

701T 

FL2S0 

2S0  Hf  CW  Filter  for  R^4C 

55.00 

?013 

FL-500 

5O0  Ha  CW  Filter  for  R^C 

55.00 

7D1S 

FL-1500 

150Q  Hz  RTTY  Filter  for  R-4C 

55.00 

7017 

FL-4DO0 

4000  H^  AM  Filt&t  forR-4C 

55,00 

7019 

FL-fifVV1 

finno  Hi  AM  filler  (or  R-4C 

5S.0O 

VHF- 

FW TRANSCEIVERS  AMD  ACCESSORIES 

T330 

UMK-3 

Rfin^Dte  Trunk  Kit  (or  UV-3 

69.95 

T339 

-^ 

Extra  Gantrol  Head  tor  UV-3 

00.00 

1535 

1525EM 

Encoder  Microphone  for  y  V-3 

49.95 

AMPLIFIERS 

1528 

L^J 

l60-1Sfn  Amplifier,  Potmr  Supply 

1090.00 

1578 

t-7E 

T&O-tOm  Amplifier^  Rower  Sup<ply 

1090  00 

ANTENNA  TUNERS  AND  ACCE5;S0R|ES 

1538 

MN-7 

2S0W.  160^  10m  Tuner 

175.00 

1539 

MN-270a 

2KW.  160'lOm  Tuner 

269.00 

1510 

g-ioM 

4  1  Birlun  for  Mf^'7/IVIf4-2700 

76  95 

1533 

CS-7 

RerThoiE  ConiToHed  Ants^nn*  Switch 

%mm 

!S14 

WH-7 

1J.54  MHf  20^^200/2000  Wdttm^ter 

mxm 

1  ^.^Q 

DL-300 

300W  Dummy  Lo*d 

26.95 

IB51 

DL-100Q 

lOOOW  Dummy  Load 

53 .00 

1529 

FA-7 

Fan  for  DL  -TO00/TR-7/PS-7 

29.00 

HF  TRANSCEIVERS  AND  ACCE?{.*vOFllES 

1336 

Tfr-7/DB   : 

'   D^ga^f  HF  trsn&Deiwei  TfiO-IOm 

tr«-eives  t  5-30MH|» 

?  1549.00 

1537 

NB-7 

Noiie  Biankef  for  T R-7 

90.00 

7021 

SL-300 

300  Hr  CW  Filter  for  7-rin« 

55  00 

7022 

SL  5O0 

SOOHiCW  Filter  tpr7-Nnfl 

55.00 

7023 

SL-ieoo 

taOO  Hz  HTTY  Filler  for  7^ine 

55.00 

7024 

SL-60D0 

€000  Hz  AM  Filter  for  ?-lirw 

^UO 

1S3S 

AUK-7 

Av^liary  R^fi^s  P"f curiam  BovtS  for  TH-J 

ffor  OUT  oi  bar^dcovera^) 

4S.0O 

IS4G 

RRM-7 

Ran^gf  Receive  Modules 

B.50 

IS47 

nTM-7 

Range  Tranftceive  h^dulei 

8,50 

1529 

FA-7 

Fan  tor  TR-7/PS.7/OL- 1000 

29.00 

1338 

flV'7 

R*m&te  VFOforTH-7 

195.Q0 

1S31 

$m-7 

Sjptttkerfor  7-1  tne 

39-00 

1335 

MMK-7 

Mobib  Mount  for  TR-7 

49.95 

7073 

7073 

Dynamic  Mobile  mlc,  w/Pttiu  TF?-7 

24.50 

7077 

7077 

Dynarnic  Desk  mjc.  w/Plug  TR-7 

49.00 

?037 

7037 

TR-7  Sflrtf*ceKjt 

so.oo 

1^.00 
135.00 

299,00 
29,00 

14,60 
26.60 
10.60 
13.25 


9.50 

1D.S0 
950 


Drake  L-7 

2kW  Lin«ir  Amp4ifi«r 

iQni  iGOm  covers^.  2k W  PEP,  TkW  CW, 
RTTY.  ESTV  oi^wation  -  aH  modes,  full 
ralRtf  iinpul.  continuous  duly  cycle.  Accurate 
builNn  rf  w«ttn)#tvr.  wtlti  forwird/reverse! 
ividi^ni{|i^  (1  t#i'tch  t^eciwd.  By-pvu  switch- 
ms  for  smigi^t  througH,  to**  poiyet  opera^ 
tion  wiihoui  having  to  turn  off  amplifier. 
Bandpass  tuned  tnpul  circuitry  tor  low  dis- 
torilpn  und  50  Ohm  input  Impedanct}. 
OpersiM  from  120/240  Vac.  50/60  Hi 
priiFivary  Itrw  volUge. 


TR7/DR7  TRANSCEIVER 


DRAKE 


111   trtn    Dilt   t-cw    >e**n,    usvmtt    annttti^rr   (r«rli- 
EurH    and    imenniQun  ca-rMUmtwa    tc   bi    '^iLHA^r- 
t,  rrww  T««iMni  VMS  tKTi>KfBwi« 

at  ifw   MH«4«omBtt  vm*  nmnmmy  W  tMurw  Wll 

tK«    iviuirinii   tqiiltHnml    rapnwnlH}  mn    Adv9n«*' 

mini    lr»   e.ammwn'icMtiona  tt^ttnala^^   w|tn  mciCl 

Tnt  QfAhi*  f  AT  TnnKalvit  nv^BM»  ■  wnfqiM 

*   product  af  tfht  Onhc  ''phYtnlnt  mtwjtth  OAk^t 

K  Mar  En  dolnq  right"  ehlloioFvhVi  th«  T FIT'S-  rrurvy 
n«uu  |*cJirilqutl  itto  t!ipmra:i\ttns\  raJEutAi  cAttillM' 
Fnanl  Aurti  aiUM  prediuckng  pmtiarrT\*rir.w  ind  Eon- 
twnmtKK  wtii£|ii  wiEl  ttrntat  uii«B{jtii«4  ftrt  ifMRy 
I  la  I 


Drake  UV  3 

UHF  VHF  FMTrcnsceiver 

•  Fuliy  iv"^^<^Sii£ed  on  each  band,  5  kHz 
tispt^  distal  resdoui 

•  FM  covefdgt  on  ccwmolete  144,  220  arwJ 
440  Amateur  banck,  ilepending  on  model 
purchased  Conr^pleiielv  band-iwitched 
tram  front  pdn>el. 

•  Four  eKtr«  diode  programmable  fixed 
chjrviFls.  Mith  4ifhet^,  tveifoble  fo« 
e«cli  bandf.  m  addition  id  tt^e  TyntfiMjnf . 

•  PHCKle  pro^ammible  non-fiandaFtJ  atfi«ti 
»vdd4l>le  for  each  band, 

•  Separate  SO-239  Antenni  Connector  for 
each  bend 

•  Sc^n  a  P'Togriiit^Kfned  (ixitd  0\M%nei  Irom 
any  lynihesijer  fr«Quer<v.  Sctn  ^ny 
syncHesizer  frequtncy  from  «  pro 
grammeil  fi:xed  chinneL  Scan  a  specific 
proBrimmfld  fixed  channel  from  unother 
pfogr«iTvnie<]  fjjced  channf^l, 

UV  3  OPTIONAL  ACCESSORIES: 

•  RemovabH  control  he^d  will  Ojoeratt 
TudfQ  in  irurik  compartment  from  driver'! 
wet. 

•  P3'3  -  comoanion  #e  power  lupp^y. 

•  Drake  152&EM  Encadir«g  M^ke. 


High  Pas^  Fitters 
for  TV  Sets 

provide   more   than   40   dB  anefiuation  at  52  MHz  and  lowet. 
Protect  the  fv  set  from  antaieur  transniitiefi  6-160  meters. 


DRAKE  TV-300-HP 

Uodel  No  1603 

For  300  Ohm  twiri  le»d 

eHv  intiell^Yior^. 


New  Termirvali  far 


DRAKE  TV-75'HP 
Model  No.  leio 

For  75  Ohm  iv  coakiel  cabEe;  tv  typs  "¥*' 
eonnecion  imuHed. 


Low  Pass  Filters 

for  Transmittejri 
have  four  pi  sections  for  sharp  ciit  off  above  the  hf  amateur  bands 
and  to  aTtenuaie  trartsmitier  harmonics  falltng  in  any  tv  channel 
and  FiM  band.  52  Ohm.  SO  239  connectors  built  In. 


DRAKE  TV  3300LP 

ftilodel  No.  IfiOa 

ICX^OkV    max.    below  30   MH/.   Aderru^iof^ 

tietter   ^isn  80  dB  Abcn^  41   MHf    Heipi 

It    t4    interftrerice.    ^   vvaII    a^   hirmonic 

intErfsronce, 


DRAKE  TV  42  LP 

Model  No.  1605 

A  four  iectioii  1 1  Iter  deiigned  with  43.2  MHj 

CJjT-ott    and  oxtremetv   high   ittanuatnin   in 

ill  tv  channel l|  for  trensmitteri  operating  j| 

30  MHf  and  lower.  Rated  100W  input, 


P.O.  Box  27,  Medford,  Massachusetts, 02155 


TEL.  1-617-391-3200 


TUFTS  Electronic  Department  Storei.TUFTS 


2  1    $299.95 


AlVJTENNATUlViER 

H«r«  ifi  a  ntniv  lunur  iti^  puu  inoi«  power 
into  your  fioienn*.  workt  fmm  160m.-l0m^ 
Handles  fuU  (sga^  powirr  ami  th^n  aomn^and' 
Wdrks  wifh  ccsax.  -iin-gle  wii«  smJ  (utfincecl 
timrs  And  it  le»  you  tunt  yp  4ithout  9?ing 
on  the  HT. 

All  luncn  loi«  uim«  rt  powey,  mmlly  in  rhe 
indLJCt^n^t*  cpil  and  the  hiDlurr  cord-  To  avoiH 
ihii  wc  swirched  from  No.  T2  wirft  for  thi? 
main  inductor  to  "4"  eopik«tt  tubif^  ft  c*n 
CWTV  t9l  limes  tbe  rf  cytnnt.  And  iwe'w 
momed  ttw  bs^un  fnofn  th«  Output^  where  il 
liitHHt  TH!>inM  K-Pi  111  dffsiqfi  inipe(tanc8,  fa 
lh(!  input  wrhere  u  dwdyi  sfcrei.  Thus  morcr 
pgwer  to  vour  antenna. 

Ttw  biqj^i  pfolilefn  with  lunsn  ti  gettlrifi 
ihnm  tun«d  tip.  With  three  kncitEE  to  tuiw 
qn  vtmr  trjncencf  md  Xtitte  On  rhc  njrwt 
MVt  ten  «H»mls  io  do  it  ln^  th^  i/mtfiirtq  m 
your  rranscf^jvci  manual)  \bai'%  1  j  iecond*i 
pm  knoh.  Wi?  *i3viD  0  bBttm  vvay.  ti  builT-m 
BQ  phm  rwiw  tirklge  that  lets  vchj  ice  th< 
tunitr  conuoii  without  tr^ninnitling.  And  tt 
EiArtieh  ttijii  lets  vou  tun«  yoi^  trjimmitti^r 
■Tito  a  diimnny  kMd,  So  yoy  con  (^  ttw 
wtiolf^  turxrup  Mritiltout  g^mg  on  t^  jtr. 
5av«  tihat  lin^l;  cut^  QI^M, 


n 


TEMPO 

ih^  first  in  synthmi^ed 

porr^fes  grv&  you 

the  broadest  choice 

af  Th&  iowest  pries 


^ 


^ 


* 


. .  HI  the  nfwr  S& 

The  only  ivnth«t»d  hund-helti  otiering 

5  watti  fMitpui    (SifvilchBble  lor  t  or  & 

watt  opciaiionj 

Tho     same    detMfldabilliv    as    the    tirTie 

proven    5  1-    Drcuilty    (Hal    li«&    tMee« 

proven  ill  «?tone  ttion  m  vniWwm  fwun  ol 

operation 

Heavy  duly  batiirry  p3c)t 

Telescoping  whip  ant^nnn. 

Nicml  U^li«ry  pack,  charger. 

^Kterriiil  rnicrophoriB  caE>flhiEity< 


PRICE  LIST 

Tempo  S-S 

$199  QQ 

Tempo  5-5  wittt  touch  tone  pad 

339.00 

12  Button  touch  to»i«  pad 

(not  InstaHedJ 

39.00 

16  Button  touch  tone  pad 

(not  iniUlledJ 

4B.00 

Tone  burU  gen«rator 

Z9.95 

CTCSS  iub-4u^t|»1e  tone  control 

29.95 

RiJbb«r  fieK  antenna 

B.OO 

Leather  holster 

16.00 

Cigarette  lighter  plug  mobile 

charging  unit 

6,00 

Matching  30  watt  output  MM  VOC 

power  amplifier  (S30] 

19.00 

Matchinf  BO  watt  output 

power  amplifier  (5S0) 

149.00 

Tempo  S*Z 

34§.O0 

Tempo  S-2  with  toucti  tone  pad 

399.00 

Tempo  S*i 

2S9.00 

TeiTipo  S-1  with  touch  tone  pad 

2i9.00 

^ 


^ 


^ 


ttw  Tempo  5-2 

Tempo  Hi  hm  again.  Thit  time  imih  a 
i&upcrjar  quality  synthesirml  220  MHr  hand- 
hDJH  tran^fiuiwer,  VVlth  an  S-2  in  youf  car  or 
pHDcket  yn-u  can  aim  220  MH?  rvpeattrn^ 
thrtiughDut  the  US  U  ati^n  tti  th?  ^dv^nc;- 
Ed  cn^neerifig,  pf«miiKn  qijaStly  cofrrpo 
nentk  and  evefiing  f eaturci.  at  ifte  $■■  1  ^  The 
S-2  uffen  10D0  chanhei^K  in  jn  CKirBmely 
Jightw^ighl  but  ruingt^iij  daEff. 


^ 


^ 


H  youV^  not  Of!  230  this  il  (he  p^ttect 
way  10  flH  itctitcd.  Wrih  the  addition  ol  rhe 
S  ?S  r25W  outpull  01  S  75  r^5W  Quiiiut^ 
Tempo  toiid  fiate  amplifief  It  bcomin  a 
piwferfiil  rmibtle  <y  taie  ttaticm  If  you  i^jw 
!  220  WHj  r^^  itie  S-3  *itl  add  frMmndipus 
MTMfdjiv  It*  low  price  'ndudrv  ^  <«ternal 
iTucrophorte  cjpahiiljiv,  Keavy  duty  nJ-cad 
iMttury  pack,  charger,  and  lelcficoprng  whip 
antenna. 


Teinpo5-1 

•  Tfi-c  tint  and  rnost  thorough  I  v  f'^'cl  n.iited 
hantt-iield  Kyntheil^erj  radio  LivatUktile. 
BOQ  i:hjinn«lt  in  th?  p,tlm  of  yftur  hgnti 

•  Simoir  to  ofttvatM.  lYoo  dof»*t  n««d  a 
degrae  *n  compuref  programmijig}. 

•  He«v  duty  tvittety  ppcA  alloim  nkprc 
optf rating  lime  tketv»rc<fi  char^«, 

•  EKt^rinal  micruphonis  tapaiiUltv 


^ 


J^ 


J^ 


Jf 


RX  NOISE  BRIDGE  S55,00 


Liirn  ihe  iniifh  pboui  foiir 
FInet  rts  rtritonani  friiquency. 
Find,  H  i(i|  X  olf  Pflianinqt. 


FREQUENCY  STANDARD 
$42.50 


5  »a,  iMm  hM«' 

iklt  fef  pnel  nnl£li. 
CfyitH  cnrtitiei. 

k  imt  secmdifY 
frmuinirii  itindl^rd. 
Squire  Wi we  Signal 
flKii  hirmiinici  uaabk 
fdim  S  kHi  14  513  MHi 
SMip  ^ff  Diut|ot. 

pffifCi  imivMteft 
(nirheti. 
Iftttry  Optrited 
Nt  line  cortd.  Sell  cun 
lainf  0  baltEfy, 


VLF  COISIVERTER  $59.95 


^..-fsS*^ 


»pf  Ri  up  trie  wBfti  ti  fLf  nAo 
OMveits  VLF  la  fid  m Fieri.  For  uic  wn^  tn^ 
thinllMlive  rrceivi^F  covrrlnig  1.5  4  MHf. 
Advanced  disli|n  fnr  ilmpieapet Allan, 
Mgh  performance. 

Bfvct  fteepHin  |il  Ihc  1 7SiQ  nuier  bind, 
mil  Mmrt  npnulitfl  riirteicoii.  wwvi, 

t.  tiiiif  bi«l4cixt ha«d 


RF  TRANSFORMER  $42.50 


Fill  Z00«  Hilt  CW  (5-lfw  f&l 

HatClwi  132  74.  2?.  11, 1?,  1. 5  «iim  fiUcmD. 

Fw  ah  vcrtt^ial}  jind  mcbile  whFp  airtennai. 
Smgnci  Slit  tligh^r  efficiency 
RF  lerrrte  lornM  core. 


LOOP  ANTENNA 
Loop  Anrtpliff«r  S67.50 
Pluj-in  loops  $47.50  ea. 


mue-in  taofn; 

■valaWt  tir:  ^ 

lEOIhieOOieMi  ^ 

nesftp  nc^ 

amiteut  feaadtt 
55fll6l»0Km 

(Bukiticast  Band) 
1M550KHI 

IV  LF  I75{lmfref  bandi 
4b'150  KHi 

■t  iflferte'tflce 


500  W.  RF  TRANSFORMER 
S3S.00 


Caovcmifit  f  iFilch  lelectAA 
Df  jifipfEJantie  iipi. 
Snviii  soc.  High  eff IctinEV. 
HFferrltetoraidcdrf. 


IC  KEYER  $117,50 


Sendi  M#muJl  Svmi 
Aiftomit^t.  Full  Aulamatic, 
Dot  Memoiy.  Dash  Mfliiidry, 
Sqyft?«  »ifa  lamtMc 
Hart  N'lfsris  tfejn  fay  Dtl»T 


^i^MkitliUEcaatact! 
teflSiM  TIh 


pnlcd  putOt  liuc>  wff  Amjie 


fPii 


Barttiry  Operaleil.  Iteify  shicMtd  ifie  Mil 

melalcflKT  3  lb.  ili^lbasc 

Bv  itiF  world's  oidtti  manvfaelurer  af 


CW  FILTER  $39.95 


Ptff  tfcrn  II 

tVCJW^IIlC  fPHn  UnM, 

MNzlSindwidth. 
Elglil  iMte  C  Iriter 


ALL  eANDS  PREAMPLIFIER 
$8S,5D 


BEAM  BALUN  $47.50 


MODEL  2KBALUN    $42.50 


Tiinei  IB  id  ^4  MHi  C«vEri  ALL  imalBut 
DtndK  16(1  to  &  mtltn  ALL  liiortiNJivc 
brQjdcfsl  tunds. 
fat  nctttttM  Am  irtiiitmwi. 


3  Kw  CW,  E  Kw  PEP  iftpul  jiowfff . 

U  bfill  far  r'  bmm, 

1.7    30MHL 

1:1  Qr  41  ratidiviiUUi 

Al  itiinteis  iltc^  h«^dwtrv. 


M0DEL1KBALUNS22  50 


3  Kw  CW,  &  Kw  PEP  ttipifi  pawir. 
Replacit  anttf  miudlar. 


1.5  Kw  CW.  3  Kw  PFP  input  p«W«r. 

t  rso  MHi 
1:1ir4:ni» 


*  Ptpifittol 


ilSd 


PALOMAR  ENGINEERS 


P.O.  Box  27,  Meflfford,Mossachusetts, 02155 


TEL. 1-617-391-3200 


TUFTS  Electronic  Department  Store  .TUFTS 


Tools,  Parts. 
Accessories 


Diagonal  Pliers 


Needle-Nose  Pliers 


$8.37 


'&6CG 


$6.60 


$7.13 


$8.27 


^57CG 


38,87 


•m 


*66CG 


$7.48 


pin** 


Long-Nose  Pliers 


$7.33 


F*  UMIitCinal   uNfirti  tor 
inp.il  ■>  iftjiiir-  r.ulli'iy 


S6.85 


■4TCG 

tip^r-^rii  i1  I  '.A'     i^vMi  u.il 


S7.92 


'51C6 

BT  long  r^ne  D\t»n  Atih 


^ 


--% 


$6.37 


"S2CG 

fi"  iort^  ncmfl  pfiera 


XST-5  —  Super~Tru  Tip  (phillips 
type)  Screwdriver  Set 

Contains  5  pieces  —  aft  PfitHips 


$13.97 


5^' 


I 


-3 


$14.76 


SDS-44  -  Square  Blade 
Screwdriver  Set 


Adjustable 
wrenches 


^-ZLMit,  '^Jsiti 


Xf  t'l  itti  ■.  miiti  -.1. >'■  rh.i  /iii'iii-iri    i»:: 


hi 


N 


$7,28 

Wire  strippers  &  Cutters 

loo^x    $2.63 


Quality  Coaxial  Cable 
for  All  Applications 

•    LOW  LOSS  CABLE  ♦  NON  TARNISHING  CONNECTORS 
•   FACTORY  ASSEMBLED,  TESTED  FOR  100%  RELIABILITY 


RG58/UType 


PART 
MUMeER 


DESCfflPTlON 


581-583  » 

S370 


$4.10 


!&     i*ngin  *iifi 

on   dOfh  &Kf^ 


Ai^UCATlONS 


3'  l&ngirt  wTh 
csn  Doth  ernj* 


5'  i«n^h  M<in 
l/HF  CB  plug 


fTioibiiie  i  E309*  Mation 
Swn  &  po*er  rTi«l«fft.  an- 
tenna ■si*iirhea.  tind  EWH 
maichBra 


S4J0 


$4.99 


56i-5ei?« 

S4.99 


$6.49* 


1j?'  lAngth  wnni 


20    mr^g\r\  vnTh 
UNF  CB  pkuQ 

A.  Spade  lugi 


on  botfi  fluids 


$7-25 


$929 


$10.99 


20'  Iflngrh  *ii:r* 
UHF  CB  plugs 
on  iM^lh  «ridi 


K}%mi  to   con^c^cl   mobilii 
CB  WlB  10  irunk    mirrcx 
QuTfBf   or    iHJmpfrr    mounl 


BG  58/U  Type 


RG  8/U  Low  Loss  Type 


RG  8/U  Low  Loss  Type 


U»4(l   10  oonneci   matme 
CB  set*  to  iivth    moffQT 

:intertna»  requinr^  m  UH^ 
R    p\xtq    lernipniqtipn    Eo 

iiiP>  anlenna 


5Q'  length  MPih 
UHF  C8  p4t#gs 
on  both  ondft 


?&■  longTh  with 
UKF  CB  plugs 
on  both  «rtM 


KKi'  lertgih  wif^ 
UHF  CB  pluqs 

on  borh  en4» 


S4:10 


oescnpnQM 


$8.5a 


riiometer  npible  m  requi' 
ed  arid:  -fignai  itjs*  is  noi 


561  ■050-4213 

$14.99 


5fll^?^-*?0 

$22.50 


$26.50 


1'  |i«ngtns  wrifi 
UHF  CB  plugs 
an  bolh  «nds 


APPUCATlONS 


^'  (Df>9rh  wrth 
UKF  CB  plugs 
on  bDih  endA 


75'  Jen  1^1  h  *(th 
UHF  CB  plugs 
gn  bOflh  e>r<ds 


1^ 


UHF  C&  pii^a 
an  tooth  end-s 


used  »  pjiich  cof^  Idi 
morula  and  Das«  srsiffxi 
SWJf^  And  poASf  irn«|«rs. 
^irtl^nng  ^^i^ilches   &  SWR 


Ltsvl  lo  QonnvcT  motriie 
Of  l3«se  statiorts  mun  ^n. 
tofiii^as  rBt|uiring  <a  UHF 
CB  plug  titrrniniation  ai 
jr»  rtnsenns 


U3*d  ID  connect  b4$e 
siairqo  CB  His  with  tmse 

anifrfinas  Where  tmi  is 
crlncAl  there?  cablsi  wjll 
out  p«ftp|pi  nG  sa  u 
cables    or    ih,e    ^i^ne 


W^m  Cushiofi  Grip  Handles 


H  r        I- 1,!,    "ii; 


Iv^liir    I'^td^L-f    H4I0 


^101 -s    $3.32 


$10.08 


•103-s    S4, 12 


104CG  Wif^  Stripp<r  and  Cutter 

^ilUf   JCf"'-''-  -■■''   ►*«!*  IIP**?    -  ■■''"^^ 


LAB  QUALITY  CABLES 

BNC  Test  Vottage 

1500  vac;  FVeqiiency:  0*4  GHZ;  Impedance:  50 
Ohms  oommal;  Cable   Retention   Force:  60  lbs 
minimum  (RG-SSC/Ul 

UHF  Test  Voltage 

1500  vac;  Frequency;  0-500  MHz;  Impedances 
Non  Con^ani;  Cabie  Rtiention  Force:  60  lbs. 
minimum  iRG-58C/U| 


Sa  Olini  UHF  Rug  |o  UHF  Rug 


Na.G&t 
No. 652 
NCI.6&3 


3  fm 
10  feet 


$  6.S2 
S  7  OS 
S  a.34 


SO  ohm  ^^C  Pk^  to  UHF  Rug 


Ha  6^7 
No.  fisa 
No.  G5e 


1  foat 
3  le«i 

&  feet 


S  7,20 
$  7JZ 

£  e.24 


SO  Otwn  BNC  Rug  to  BNC  Hug 


No    668 

3  feet 

S  8J1 

Nd.fi62 

5  feet 

S  343 

N4,66G 

lOfHt 

S1<>J3 

P.O.  Box  27.  MedfordfMassochusetts,  02155 


TEL.  1-617-39J-3200 


TUFTS  Electronic  Department  Store.TUFTS 


Panasonic 


S  179.00 

Panasonic  RF-2200 

Internationa!  Band 

Eight-band  worldwide  shortwave 
radio.  AC  or  battery  power, 
Indudes  AM,  FM  an.d  ^ix  short- 
)fliB\te  band&.  Combination  2<na9e 
selectivity  and  AFC  swiich.  RF 
gair^  control.  Separate  bass,  treble, 
and  volumG  conirols,  FM/SW 
teiescoping  afiterinas.  Four  "D" 
batteries,  AC  power  cord,  and 
earphone  included. 


S239.0Q 

Command  Series  RF-2500 

Six-taand  portabfe  shortwave  radio 
with  all-band,  ftve-digit  fluorescent 
frequency  display  -  SW  frequencies 
from  3.9-28  MHz.  FM/AM  radio. 
Battery /sign  a  I  strengfth  meter. 
AFC  on  FM,  RF  gain  control, 
4"  dynamic  speaker.  Comes  with 
AC  power  cord,  shoulder  belt 
and  earphone.  Operates  on  6  "D" 
batteries  (not  included). 


$249.00 

Command  Series  RF-2900 

Portable  5-bar^d  shortwave  radio, 
Five<ligil  fluorescent  displav.  SW 
from  3,2  to  30  MHz.  BF  gain 
COmroL  BFO  pitch  conirol. 
Comes  with  AC  power  cord, 
shoulder  belt,  dial  hood  and 
earphone.  Operates  on  6  "O*' 
batteries  (not  inclijded). 


Command  Series  RF-4900 

Ten*band  communications  receiver 
with  Bndigit,  all-band  fluorescent 
diiplav.  SW  from  1.6  to  30  MH?. 
FM  and  AM  frequencies.  FET 
RF  amplifier.  BFO  pitch  control, 
RF  gain  control.  Comes  with 
earphone,  AC  power  cord  and 
headphone  converter.  Operates 
on  8  "D'*  botterfes  (not  included). 


EKantronics 


Our  smart  machine 
reads  sloppy  copy. 


Drake  R^7  /  DR-7 

Svi^tHeiiziyci,  G^nsraj  Covorsge  Re<:'BJvor 


DRAKE 


S«e  back  cover  tor  ipectalf  I 


with    y    (j^^>~n&a^lllty 
(PTO^     for     smooth. 


Fully    lyfithe&lzcci 

tuned     o^dKator 

continuous  tiuFi.ing^ 

Qo'wrs  complete  ran^  0~3Q  VHz_  Both 

digital  snd  VHhjg  retdoui. 

SfKcuil    lew  dittortiDn    "si^rvchro-jGriuH'' 

AM    dcri^ctor    provii5»    tuperidr    inier^ 

nitiortal   (hortvvavi^  hroadcait  receptlcm. 

Tunable      \f     nolcli     filrer     eff^alvsly 

I'&ducH     Iretefcdyrte     intef^ereJice    from 

neAfitf  iCAiiorts. 

Mutn^furtctJan  atiMnna  setectprySO  Dhm 

s^itlft  I*  fMrhch-trl«cleft  from  tht  front 


$1449  00 

fHkiml,  ProvMles  simullaneoiA  tftiiil  ncetm 
with  the  TR-7,  mil(,irig  poiiible  iht 
receptiqn  af  two  different  tr#crijenclei 
iit  the  same  tim&, 

Built-in  power  lupply  opirrAles  fram 
1W,  170.  300.  140  Vk,  50/60  Hi,  or 
riominai  t3£Vdc. 

M<UCtl  rt^QHEfill 


NEW!  INCLUDES  24-hour  UTC  Clock 
110  and  300  baud  ASCII,  St  tuning  eye! 


Kantronl 


iFielcl  Day 


® 


$^9,00 


If  someone  tells  you  they  offer  the  same 
features  we  do,  check  them  out  with  the  list 
below. 


See  tjacic  cover  for  speciaU! 


YAESU 


i 


FRG7000 


$599.  CM) 


Morse  copying  ablffty 
3  to  80  WPM  Morse  range 
Computer  programs  for 
improving  sloppy  Morse 
Radioteletype  copying 
ability  ^60, 67.75  and 
100  WPM  Baudot 
ASCII  radloteletype 
ability  -  110  and  300 
WPM  baud 

Copies  any  shift  of  RTTY 
24-hour  UTC  clock 
available  in  any  mode 
Erttire  unit  contained 
Jn  one  package 
Automatic  code-speed 
tracking 

Fyll  lO-characier, 
laroe-size  display 


Difptsys  code  speed 
Tuning  aye  for  faster 
tuning 

Full  year  limited 
warranty 
Internal  speaker 
Requires*  no  TV 
sat  for  use 
Advanced  demodu- 
lator circuits 
lr>ternal  200  H2 
bandVvidth  filter 
AM  leters,  numbers  ar>d 
punctuation  plus  special 
Morse  charHcters  and  5 
special  RTTY  characters 


Digital  Dfiplav  Cammiinicstioni  Reccivor 
with  CPU  Dtgitdl  Cl(}ck  4n<i  Tkrtar 
•   0.35Thry39.9MH£CoiffirB^  v^ffth  lfcH^ 
Readoul 

lutn  sfc  brminht  togerher  in  if)t  FnG-7OO0. 
i:  dig[i1al^ti.piav  ^ermrai  cow^rige  r*ceiiir«r  lot 
th«  disci  iiTiinatJnf  SWL.  The  li^gital  clock 
jnd  limer,  conirollGdl  bv  a  CPU  (Central 
Processing  Unit)  ch<p,  «viJI  read  oul  l.iolh 
local  and  GMT  tlmif,  and  wilt  i;antrc?l 
EWfiph«ral  fiitiCNi  ec|u>t;rTiG!ffit  such  as  a  tape 
rteord#f^ 


FRG7 


$299.00 


Gftkeral  Cav«rage  Recfliv«r 

«   0.5-299    MHf    Cofttiqt   #ith    10   kHi 

FCeadbuf 
The  FRG7  rt  *  pt^OviQn-tiuiH  an-purpo^ 
cnmmunuiafticim  r?ce«K«r.  featuring  ill  ioi>ii 
INI*  canmuctiCKi  tm  loftg  («fe  ifld  high 
fter f 01  manciT.  Uillljfingi  the  Wadlty  Loo|i 
drift  cancirllation  tysTiirn,  In  co/tjtirJCFrfin 
WMh  ji  triple  L:x>r>'vt^(tit)n  lupcrKtieJ-odyn. 
Ciitiiiit.  the  FRG'7  tiomti  h^fh  «ensitivilv 
along  with  ««c9<i&nt   itibiRt^ 


®  KENWOOD 

^T^     . .  .ffitfi.wttt't  itt  amtttrtif  f  taint 


WTOtft 


$499.00 
Kenwood  R  1DO0 

Th«  R  1000  11  J  njghlv'  adaarmct  communi 
cjftictm    recerver.    Up-ccfweriion.   PLL    cir 
cuitrv  *fKl  fPffier   rmm   tedtmolog>f  provider 
Optimum    wntiiivitY.    scleciiviiv,   and    iti 
bill  I V  1'ronn  200  kHz  to  30  MH/   F^atunni^ 
^Aiyia-opctMii      single  kfTOb      tun i rig     Rpiii 
digital    fr|fq>uitni:v   dliplay^  ilt'f  perfect    for 
lt(,t<!ning   to   vhoffwave.    medtium-wave,   and 
ktn^wwn.    ti4nck_    Evtn    £iSB    tionali    jra 
rttrnved    perfectly.    Included    ri    a   ciuaru 
dkCjKta^  dock  «nd  ttnwr 


■1000  FEATURES: 

CoritFr^uoui     fref|uervcv     ei0vtt4§t 

?00kHjio30MH/ 

30  haneb,  e«eh  1  MHi  MnHift- 

Fjvt^igit   frequenCY  dnfilvy  4rsd  iflumi 

nated  anjIOQ  dial 

Ouan?  difliTil  cicurk  and  ON/OFF  timor, 

lyiuiti-madHs  .      AM   (wicte  imi  narrewli, 

SSB  (USB  jnd  LSei,  #nd  CW. 

Three  if  hltBTs  ...  2 J  ItHf  tw  SSE  jmi 

CW,  &i>  kHt  for  AM  nmrwt,  «n^  \Z  kHi 

lot  AM  wMSt. 

Elt«ctiw  n0't<te  blanker^  built -in  spealter, 

|fir«  tntanna  terminjli.  rf  if^ti  attenuii 

for,  tone  ErantroL  rfit;nrdlng  tnfminaJ. 

Rifmors    tflrminal.    far    accu-sa    to    tinier 

riiay  QNfQff  circiitf  and  mutiing  cirduil 

SSB   ^icmnitvirf   of    O.S  nV    trom  2  to 

30  MHf. 

Mwe  thftn  €0  dQ  IF  imj^fatict 

More  rhan  70  d@  IF  infect iofi 


P.O.  Box  27,  Medford, Massachusetts,  02155 


TEL.  1-617-391-3200 


TUFTS  Electronic  Department SloreTUFTS 


$299.00 


BEARCAT  220 

AiTcr¥*f .  Mannt,  Rubric  Sprrpce  Th#  220 
jaddi  faitum  imd  ndnunc^  lopfiiiticatiafi. 
Aircraft    ajjd:    Marin#  —  press    tniitori    m 
sfisrch  eniirA  Aircrafr  Band,  onaiher  for 
Marine 

7  Binite-Low,  High,  U^JF.  UHF-T, 
2n>  trnfteur  end  75  CM  Ham  -  plm.  the 
AafumH  Bund! 

20  DtinnEH  —  tan  it^  lo  20  fr«qucnc»«f 
or  tfither  of  two  tkinlts  of  10  channvtt 
each 

Automatic  Seifch  -  Selective  Scarj  Otlay 
-  AulornBt^c  Lgnk-Oul  -  Patented  Track 
Tuning  -  fM^nuaJ  Scan  Contrt^  —  Skug/l* 
Anienfu 

Prrpritv  -  *utocn»tJciMv    9mp4et    dn(f 
ridtf!^  channel  ffVB'v  two  ircontjn 
AC/DC  apftCftt^Dn 


Ot> 


BEARCAT  300  *429,95 

5«rvic«  Svfli  eh 

Ow*r  2100  pn-pfogMinmed  fritqueficin, 

•  11  Sef^fice  Searcti  catogorips  nr range 
stored  frequencies  into  "intcreit''*  groups 
-  PqUcp.  Fire.  Miiine.  HAM,  Emetgcncv. 
Trlephone.  Gov^Atnecii^  Forestry.  Indiff- 
Tftol.  TinmportAtkin  md  Aircraft. 

•  SO  Ounnett/S  tundt 

■  7  Bands  I  Low  &  Hi#i  VHF.  UNr=.  and 
UHF-T^  AM  Aircraft.  2m  St  ?S  CM 
ArriBtfliirf 

•  Non¥Dlitile  memory,  AC/DC 

•  AutafTUHtc  Search  wiih  Hold  &  J^vajma 
lunctront 

•  PneniiHd  SftectJVirScui  Deity 

•  Vacuun  FlijorvfCfnt  DecirtiAi^fiplav 
with  Dimmer  Control 

•  Spfled  Control 

•  Quartz  Ctock 

•  Pitented  Track  Tuning 

•  DiTEti.  Diacvnel  Acces 

•  AuiDmatiiC  S^ueletti 


^i 


^\ 


$143  S5 


UAMCAT ' 

FOUR-SIX 

TKINSCMI^ 


More  hands,  mar e  chAnntit  —  more  Kannmy 
eai^abili^tiet  than  athsr  Hand  H^sldi. 

•  4   a*ntli    (Low,  High,  UHF  and  UHF  T] 

•  6  Channel  -  moft  rTKHihoriD^  capat^ity 

•  ^'^l^utriKf  Due Jiv"  Antenna 

•  ^It    Clip    tr«es  hands  whrle  monitoring 
«   8  c^tannels  per  «ca<vd  ican  ifived 

•  Auhsfnatte  or  rnsri'Ual  tcanning 
■    Individual  chanrtel  lock-ouit 

•  Poi  1  able  —  weighs  only  12  ouncEi 

•  Baitery  operated  {6  Vdc) 


$  1 99.95 


BEARCAT  210 
Tha  one  thai  pioneered  lyntheiized 
scanminQ  -  and  unlocks  ihw  channels  of 
ccum  m  u  nicatic»n« 

•  ^kJ  it^mii.  to  buy  -  full  S-btndtsMtmaqit. 

*  Kevcnard  piogfamming  maltei  freqtKncy 
fekction  d  easy  at  puruLhirbg  Ji  pufh^ 
button  lelephOfV, 

•  Decimal  tti'ipfav  and  exclusive  rolling 
z^roi  TO  sr>ow  whiii'i  beina  program  med- 
and  monitored, 

*  Auinmatic  vt^it^  lor  firnlirtg  naw 
tret)uenci«. 


PUMCHES  THROUOM    LOW  and  CLEAR 


|ii:i.t:t 


Only 
$17S.OO 


Cohra  2aGTL  ^scogntiwl  Induiiry  Standard 

Ctift'Hi'i  mci»!t  p«pul»F  Cl^  motjilfr  — in*  '  Trwckoi^  cndiCi"' 
«  Delia  lune  ■  QfnmVin*  »  *,m*r\r\»  trarmns  ^deataf  • 
lltyimjnat«4  $  RF'SWR  mvfer  *  SpitcttabHr  autdmiiiit 


Cobra 

7BX 
OtoUar 


Only 
3pS  9i9^ 


Tii%  to  tn*  tie^i  sf  in«n»  wiin  inim  vfvnomir-sTie^ 

eco^Cfny-t3-flC'i<d  CB  ■  Large  tllufnuFialed  (unidg  dial  * 
SerfrlNy^  iquelari  cc-nlrcJi  •  Full  rervg*  ^Qiit^me  cctiifoI  "  PA 
licK  +  Le^il  maximufn  la-Ulput  o1  'flur  friitt 


3    ©    ^   ^    VIJ 


Only 

$124.95 


Ceibtm  2S(jTL  FuM  Fec$uie  CompKt 


Only 
$96.00 


Cotin  31<jTL  ComiTtand  PerfDrman«i"'Mmi"  Slu 
Has  all  iriu  boBi'  Id  pu<ic»i  lh^oug'1  iuucl  and  LJaar  ■  DigllMJ 
LED  cfiannv)  di-sfi-ia^  •  '  DYnjiMiika  «  SHitcha^if 
avSpniBlic  nooe  linul^n^  •  Iilumi4ip]e{]  S'HF  Met^^  v.nc] 
fnueli  RMsm 


Th«  Cckbti3  IIOGTL  fi»kU«  '^raa  fou  RHnumiin 
disiaikee  Willi  13  full  wqni  ol  pe«»«t.  jg^  quieter 

bond*  h  peH*ei  mofe:)!  let  iSieCobte  142GTLJ     S249^95 


Only 
$353.95 


Coium  A42CTI CB  Base  StMka 

T)t4^  COBRA  142GTL  SSJl  ,^\>t  H<9ik>  StalK>ri  1a  fof  CB  wfs 

who  iwcml'  evUp  diBSancv.  Fult  L2  wQ^i^  a\ po'v^et ,  nuiplei 
commyniAiiJ^na  due  to  ^IimiinaUan  Df  AM  'i^LuiE«."  and 
E20  civanoeli  —  SDoJ  Uiem  do  ekfe^bond 


base  stations 


CB  Anl«nnss 

AV-101  ASTRO  PLANE"  —  Patented  perform^ 
ance  B&st  vaJue  avaiiAl>)ft  todsy  in  ah  omni  d^rec- 
li&rha]  b^5&  aritenrta  ^mj  q^ 

AV^t22  PDL  11"  —  Patented  design  dual  poiafily 
antenna  with  Drtiltai  gamma  matcti  Light  weight 
and  long  range  communLcal^onf  In  a  beam  anienna- 
Five  eieiTkanis  on  each  polarity.  SI 99  95 

AV'UO  MOONRAKER*  —  America  S  most 
pOflutar  and  most  imktaled  CB  antenna  design  ifi  a 
dual  polarity  beam  Includes  cast  aii^mFnumi  hubs, 
stainless  sieel  tip  y^ires  and  many  oih^r  Avantt 

quaMty  features  $51S.95 

AV*1*6  MOONRAKER*  —  Kihg  Of  CB  antennas. 
An  the  quality  feati^tes  dI  Arantii  Moonf aker  4  plua 
the  cx^sive  ^-iti^f  boom  support  that  proittcts 
4!|i|iril)n!^trijctura]  failures  comrmiri  to  com- 
^T^iiper  big  t>eam  antennas^.  S99  9S 

50  ASTRO  8EAM  '  —   Big  power  in  a  smaJI 
l^^kage.  Unprecedenied  4G  dB  froni-to-bsck  ralJo 
three  element  vertical  beam. 

160  RAMftOD'*  —  The  versatile  all  purpose 
antenn>a  *  CB  •  low  Of  fMgh  band  Business  radio  • 
shon  ^ave  listening  •  monitor  •  TV-FM  *  civil 
defense  *  amateur  •  aircraM  *  msuine  •  encp^r^rnen- 

ting  <  a  no  nonsense  full  1/2  wav#  antenna  that  is 
fully  ad|ustflble  Irom  2&  lo  175  MHz  {adjustment 
chart  provided}.  ^^Q  QR 

AV-tTO  STGIIA  W"  —  Second  generalion  ^S  wave 
wiin  incredibly  low  S  W.R  .  S  14  dBi  qa\n.   New 
^taUc  arresror  system  Easy  mstailatiort.  New  H  D 
mouniing  lube.  Aircraft  quaHty  aluminum.  I^ew 
tow  price.  Sa9.95 

AV'19Q  SATURN"  —  New  scienlifjc  breakthroygh. 
Now  vertical  and  horiztmtal  polarity  in  ai^  Offinl 
dlrectionaJ  antenna  Stmng,  itm^  dieiance  power 
in  a  unique  dual  polajiiy  destgn.  Unsurpassed  om- 
ni  power  flain  and  SWn  charactenslics  Static  ar- 
fats  tor  systerri  for  clearest  possible  com^umcar 
lions  in  atl  weathe^r  conditions.  Easy  assembly  — 
aero  space  liQht,  Ngh  strength  conaUucflon 
tested  to  wdftsland  years  o1  wind  and  ^e airier 
SwitchlMii  t'nciuded  £199  95 

Tri^Batfd  Monitor  Antsnm 

AV-S01  ASTROSCAN'  — ApatefiledTr^4}and  base 
monitor  design  with  no  compromises  Uamatchad 
gain  over  the  whole  tri-band  range  Irom  25  MHz  to 
512  MHz,  including  the  new  'T"  band.  Aerospace 
light  conslriiciion  oi  aircra.fl  Qualtiy  aiiuminum  and 
stainless  sleel  is  welt  balanced  on  (he  mast  to 
wiinstand  years  of  severe  wir^  artd  weatFter 

S34,95 


P.O.  Box  27,  Meiffforil,Mossachusetts, 02155 


TEL  I-617-39I-3200 


TUFTS  Eleitronii  Department  Store  TUFTS 


OMNI 

TEN -TEC.  INC. 


OMNI-S«n«iC, 

OMNI  mcNH  tiqldlv  fonvird  to  meci  ttie 
rvw  dveads.  Witti  new  feitur^.  n«w  cort- 
fefiienco.  fittw  titdNmqus.  and  rmw  bjmd 
corveragt.  FuH  «n«tu«f  band  covtrap 
horn  ISO  ittroijgh  10  n^rtvi^  With  iti  new 
hf  ctptbihir,  OMNI  C  covws  alf  six  of  the 
pretimT  hf  bandi  and  all  ihree  of  the  ruiw  hf 
handf  Cryitdli  are  tupplwd  for  seven  bincK 
tcryital^  far  IS  and  7A.E  MHz  bgnda  Will  be 
available  wh&r\  the  b^ndi  ar?  readyl'.  New 
built-in  noDG  blanker  is  lUndard  squ4pmi3fiT 
in  |t»  QMNII-C,  A  nflw  fktiQn  with  a  l-polt 
rm>nohth*c  cryittfl  flHtr  to  handle  the 
hig  iign»li  with  one,  lo  reijlte  impoaibta 
locMiom  uub^.  Hwm  "Hv^"  AGC  9m 
imoa\tim    OQamian,    tesa    obriMii    acfiofi. 


McHlel  255  —  DduxB  PtMnr  Suppiv/ 
SfkMief  C«fnbinv«ig«l^ 
lncjud«  the  Blectronia  of  Model  280 
Hipplv  P^ui  ■  huilT-iti  3^"  k  5"  front  facing 


570 

Caolury  ai  (570) 

Novka  Exclusivs 

Purchase  your  Ceniiiry  ?t  570  from'  ua  anEf 

have  UP  ID  one  y«ar  to  apply  tt^  futi 

Dufctuia«  price  towards  a  Ten-^Tec  nKKtel 

\i\  yiDur  chcHce  when  you  upgrads  your 


MOOCL  I<3  -  Remot*  VFO 

A  dupticite  of  the  OMNI  VFQ,  Model  243 
VFD.  li  housed  in  a  mjitchl'ng  ervclosurir  and 
providps  G  modes  of  dual  frequency  i^perS' 
tion,  LEDl  indkate  SelACtion  of  any  of  six 
modes  of  operation  OMNt  trdn&miit  and 
fiiEeiw.  RCMCTTE  trinimii  and  r«;«iwe^ 
OMNI  tr*nimii -REMOTE  receive.  RE 
MOTE  tr*tfitik-OMNI  rtcoiTe.  OMNI  tram- 
mit-both  racKve,  ar  REMOTE  trtnunit- 
both  rtCRve.  Full  break -Jn  is  retained  in 
an  modn  Freguancy  Finigt  and  aCCuTiCv  \ck 
The  ume  m  OMNI, 

In  addition  to  the  remote  VFQ  capabilicy, 
Model  243  also  hai  a  4'^poiition  crySTal 
Qsclllaitor  for  fixed  rr«qijL^ncv  Dptrbtion. 
Oui-of-banrf  crystal  froqunecjes  (with  lome 
|jmitaticrti|i  niay  ^  used  as  vvejl  as  any  n- 
band  aniJtHur  frequ£n<:ifi, 

MoC^I  243con>B  with  conmcting  cibl*.  I<» 
cfysfeili.  PowiH-  is  obtaifwd  frorn  the  OMNI 
system.  Scfniqofxhjctors:  §  tranitnorf.  S 
diockK.  B  LEiDi.  SIZE  HWP  5H  m  0>^  k  0, 
wt.  3lbi. 


&' 


©t^e  y 


DELTA  —  TrMii«aiv«4 

DELTA  ii  Ihc  namp  of  a  frait  n«w  TEM- 
TEC  trafMceiver.  All  9  HF  tiands.  Firii  new 
rig  1^1  nee  WARC.  1§0ni  through  10^  including 
th^  n&w  10,  IB  and  24.5  MHr  hand&l  With 
fjViMVihIng  incorfiftrHlifd  except  ihi?  filug-in 
cryitali  for  18  jnd  24,5  MHi  ■UKirnenl& 
(jvailiaible  whan  \m\^\  open  to  amatcursl. 
No  receiver  ho^ni  end  or  tinal^  gmptifier 
ad|uftments.  Ffom  th«  pionttr  m  brcsad- 
band  design.  200  Wans  input  on  mU  bands 
incJuchng  lOm  Iwnh  50  dhm  lo^).  Hi^ 
SWR  doB  not  autofnattcvlly  limrt  output  m 
a  fpw  watts.  With  4  prpvpn,  coniervatii^y 
rated  fin.al  amplifier  who«e  soTid  state 
output  devices  arir  liiHy  warxantetl  ihe  \\t\\ 
year  and  prorata  waif  anted  for  an  addi- 
tioniil  IwB  yesri.  H^e  all  the  optiiCJ]^^  you 
could  wsnt.  VJodol  289  Nctiiic  Slanl<€r. 
Modd  282  200  H?  CW  Filter.  Model  285 
500  hrz  CW  FiFm.  Mode!  2S3  Remove  VFO. 
Moiler  7Q7  Mobili  Mount.  Model  2ft)  fSA 
PtMfV  Supply  with  over-currmnt  and  oinr- 
voltage  proteaion.  Oifker  matchirvg  acca- 
SOfitf  induct  Model  64S  Oy^  Paddie  Kryet. 
Modtl  ^0  Slnglr  Paddle  Keyer.  Model  247 
Axitefma  Ixxtitn.  Model  234/2? 4  Spee^^ 
PfOMswf  and  Mifcophone.  Modeh  215P 
and  ZISP'C  Ceramic  Microphorwi,  Model 
253MO  Ptower  Supply, 


MOO £L  230  -  Ou*a  Primary  fNwwet  SupcMy 

ICltal   for   powtring  ttie  DELTA  or  OMNI 

tranicelwers  on  wlher  115  or  230  VAC, 
50-60  Hi,  Eas,vto  chugno  for<!i!her  primary 
vD^^Eju.  Roguldled  output,  oV'Br-vaJta^B  and 
mviisr'-CLirrent  prptocted,  end  can  \m  switched 
from  trAnrsceiver  or  power  suppliy  Styled 
ID  rnaich  DELTA  ami  OMN I  coforii, 


MODEL  210  —  Power  Supply 

Di,' I  Ivors  up  to  16  Wfltl^,  sufficient  for  the 
515.  117  VAC,  SO  60  Hj  input,  13  VDC, 
±0.&  V.  1.2  A.  DuipuT.  Solid  ftalt.  Finish 
fnaichei  515. 


MODEL  20GA  -  Pi^wid  Crystal  C<libr«tor 

Companiian  to  The  515,  but  ufttfiil  with  any 
racoivJng  system.  25  and  100  kHz  funda^ 
mwitfll  with  harmonics  into  the  VHF  region, 
Pulifld  Dutpijt  lor  easy  identUtc^tion. 
Pamnted  by  the  5tS  or  any  ^M  VOC 
'sourca,  Finisfi  matchei  the  SIS. 


MODEL  Z08A  -  CW  Fiti»r^iri»b1e  Notch 
Filter. 

CW  filter  has  S-poiition  bandvvidth  fwitch, 
450,  300,  Qr  150  Hs!.  cantered  it  750  Hi; 
"off"  position  removes  hker  from  circuit. 
Variably  noLCh  hllir  i\  effective  over  rar>ge 
of  700  H?  to  3.5  kHi  with  a  ikpth  down  to 
50  dS  or  more.  Togeiher  these  tiltart  offer 
sup«t»  defense  againtt  unwanied  lit^al^, 
alkmr      op^otiofl      under      mo(i      advert 

COfMJiTloni. 


MODEL  ero  -  S^gle  P«ddle  Etedfonk 
tCayar 

y«««  transistor  iwiichlng  and  it  powered 
through  the  OMNI  lyttem.  Spetd  6-50 
wpm.  Sri  Fncomple  ting  chavacten-.  Preset 
weigh  ling  fof  opfirmjm  artkuiatiOA  ui  the 
mtnt  Mt<^  speed  r«>||ir  (dit  length  moeased 
appffoii.  10%  at  20  wpmk 


HERCULES  444 

All  Sotid^Staxa  KW  Linaar  Am^diar 
No  tubn,  no  itfning,  lull  covarage:  tQO- 
15m,  bflf>di  Matched  from  OMNI  panel 
or  linear,  initant  break-In.  tOOD  Watii 
Input,  all  bandi,  600  Warn  output,  typitdL 
Forced  air  cooling,  automjitic  line  voltago 
corrtction^  automatic  exciter  by -pass,  black- 
out rrwter  panal,  6  statui  inonitoin  with 
LEDs.  Two  marars  -  f^llacttf  £urf-eni  and 
voiltage  -  forwiird  ^<ty&  renana  power.  Nega 
thHf  ALC  woltigt,  *diust*bl*„  &u*lt  in  control 
power  siqiply.  Tape  wound  irar^ofn^er  and 
dwke  in^  teperite  pow«  sutiply.  117/ 
230  VAC,Stvl*f  to  mmc^  OMNI. 


MODEL  247  -  Antenna  Tunar, 

Match^  30  ohm  ui-Fbalanced  output  ol 
OMNI  iQ  varieiy  of  b^tanc^  or  unbalanced 
amtfaia  im|]ada<^c«L.  Univftial  Tranpcnatth 
drcyji.  4&-lap  jinducbir  alkmn  —niier 
adiustfwtenrt^  2130  warts  HitifmittBiEt.  100 
watti  oantinuiHB, 

MODEL  217        500  Hi  B  Polo  Crystal  Ljid 

dor  CW  Fiittr 

MODEL  ^tB  -  t:8  kHz  fl^Polfl  Crystal 
Ladder  SSa  Filter. 

AiODEL  219  -  250  H?  6^  Pole  Dyftai 
Udder  CW  Filter 


MOPELS  215P  ind  21BPC  -  Mkrophontt 
CflrBTY^ic  types  for  hiand  hg^d  or  desk  top 
Operation.  Include  cable,  S-^ircuii  plutj,  PIT 
twitch,  and  Kparate  desk  ttand.  Offev  opti- 
fWMim  aftioilation,  firae  of  pownr  peakf^ 
imp^rvKjus  to  tnmiperattEra  m*^  hixnidflty 
chaiiige^.  Higtr  impeda^icc.  200-4000  >^f 
response:  -50  dB  1e^:  die  £tti  fine  and 
Cycoiac;  6%1vj  4'  cable,  lin^  cofiductor 
shielded,  two  co^nducEOrt  unthirrMed.  Si^ir^ 
cull  phone  pluq  ifjcluded.  315P  hai  4' 
regular  cshk ;  2 1  &PC  hai4'  cniled  triKh\<s,, 


Argonaut  515  —  QF^  Tranl^var 

Totatir    sohd    tute.    Ml    band 
3^.  7.  r*.  2 1 .  and  28  MHi  topt»onat  cryitakl 
for   ^-30   MHzh    10m  hind  runv   in   tgui 
5O0  kHf  fegrnentf  fot  qi eater  bandspieod 
Improved  recciyet  s?niltiwity;  0-3SuV  for  TO 
dB  S+N/'N,  max,  Four-paliit  9  AflH/  cfy'ta' 
filter,  2.4  kHi  Bandwidth,  1.7  iKape  factor. 
New  heterodyne  VFO  with  r»ew  permeatjiii 
ty  tuned  OK^iilator  for  mw  frfquency  eali 
brat  ion  acctiracy.  Oirea  frequency  nddout 
with  new  dui  points  lero  lei.  VyWV  receiM 
at  10  aTfd  1&  MHi.  Offitt  receiver  tuning 
Mnth  new  LEO  mdicatoc.  ReoeiiFa- nAonatp 
conttol.^    New    des^    no-tune    bn>adb>arid 
final  amplifief .  New  LEO  rf  outjHii  inditaic^ 
flaniiei  on   2  WsTt  iKiice  p«k(.  PTT. 


MODEL  645  DuaJ  Paddk  Elaclnnic  Keyer 
The  645  kcycr  uia  iiam<eftDr  vwitchitig  and 
kk  poMnrtd  by  the  tramceiwp'.  Adjustable 
magnetic  paddle  ratum,  Paddle  force  5-SO 
(Ftis-    Speed    6-50    wpm     Weighting    r«tio| 
50-150%  pf  clanica^  dit   litngth.  Self  com 
pleting  cfinracieri..   Dit   and  {Jali  meniuria^j 
with  defeat  iw itches.  Torque  driv^  paddles 
wvith  4  ball  heurir^f]  pivots.  Powered  throutih 


the  OMNI  lystem 


MODELS  2 14/234  ^  Spaedi  PiooKior  and 
Microphone 

Extend  ^  operating  ran^  ot  nb  trans  motors 
under  adVL'riid  and  iovi^  propegation    condi 
tioni.  Converts  audb  signal  into  ssb  signal, 
dips  and  proccucs  it  through  4-iKi!e  mono 
liiltic    iiltar    for    ^^eatar    jwragt    envekjrv 
powea  and  oonverts  fignaf  back  into  auu 
Adjutiyria  lawlli  ot  processing  aitd  outr  ■' 
phrs  drable  nAritch  and  pasband  adfustmeri; 
Powered  through  the  OMNI   tvTtam  or  by 
calculator    type   ptug-rn   AC  oiidapfer  whictv 
lupplics    \7    VDC  @  75  mA.   Model   214 
Elecrroi   IWicfDphoniB  is  designed  specific^ily 
to  be  used  with  Mod&l  234  Processor, 


MODEL  DESCRIPTION 

ACCESSORIES 

206A  Ciyital  Cal^b*  Jivi 

20aA  NQtctir'OV  Rtw  to'  U^K^  51$ 

212  Ovital.fofModi^  515,29.0-29  5  WKr 

711  Dvstai.  for  Model  515.  29.5-JD  0  MH? 

2 14  i  lecTrvt  MicFDfihDna  for  Model  234 

2 1 5P  M^ci  Dj^one,  Car  amrc  with  plug 

21 5PC  Microphone,  CnT^rnic  WHth  plug  and  coil  cord 

?1 7  600  Hz  a  Polo  Ludder  Filtor,  for  MadHi  54&/546 

im  1  a  kHz  a  PoPc  Ladder  FilteT,  fof  Mi>d«is  545/546 

2 1 B  250  H  J  e  Po  le  Laddit  Fi  I  ter  J  or  M  o.  la  k  Sd  5/54« 

21A  Spirech  PraamQir 

243  Remote  VFO ,  for  ModnH  545  546 

247  Antenna  Turw 

24S  Noi«a  Bl«kar ,  tw  Mocteti  S45/54i 

273  Ciyiiat.  f^  Model  5  70.  28.5-29 J> 

275  Dyital  Caftbrator.  ror  Model  ^70 

f  ?7  Anteniia  Tunet /S/VR  Brtdge.  loi  MIodel  570 

292  250  Hr  G  Pali  Laddir  Filter,  ttH^  Mqdirl  530 

233  Remoti'  VFO,  fot  Model  530 

ZeS  600  \\f  e  Palu  L^ddm  Filter,  for  [Wtidei  5 BO 

2d7  iVlot^ile  Mpunr,  \m  Mmlei  580 

?83  Noi^  e Canker,  tor  Modet  590 

POWER  SUPPLIES 

J  to  n?  VAC  13  VDC.  1A 

7fO/E  $«maaiM0dEf  :M0.  hot  tlS.'Z^VAC 

2SS  Pehis«,  tt7VAC,  13  5  VDC.  1  e  A  with  3**  K  S* 

380  11?.'330  VAC   T3  5VDC.  1BA 

LI liEAH  AMPLIFIERS 

441  Meiicules,  1  kW  w.ih  1 15/230  VAC  Powsr  Suppfy 

TRANSCEIVERS 

516  Af^onaur,  6W,  SSB/CW,  3.5^30IWM£ 

145  OMN  i  A.  Anatog,  Series  0 ,  SSB/CW.  1  B-30  MHi 

546  OMNI  P.  Digital.  S«riei  C.  SSB/CW,  1 J-30  MHf 

570  C(?niury .'?  1 .  7D  W  CW.  3.5-29  MH  f 

SaO  DELTA,  3O0  W  SSB/CW,  1  .fl-JO MH* 

KEvEns 

645  UHrjrnirK,  Dupi  Pwktla 

670  Single  Paddk  Kevef 


PRICE 

S     'h^m 
39.00 

5.00 

sm 

39X)0 
29-50 

34  50 
SB.OO 
55,00 
50  J» 
124.00 
I3di]d 

aaoo 

4^.00 

5iM) 

23110 

85^ 

50  OQ 

179,00 

45.00 

TBA 

$     3S.0O 

S     34J0O 

39X10 

I69J30 

i3ii» 

$1576.00 

%  429JP0 
!M9.00 

nag  00 

649i» 

I     BSJOO 
34  Ki 


P.O.Box  27,  Medford,  Massochusetts, 02155 


TEL.  1-617-391-3200 


TUFTS  Electronic  Deportment  Stor^TUFTS 


FIMCO  BTlNBEir 


VHF/UHF  Antennas 


On  this  page  Tufts  brings  you  . 
FincoS  Tinker        Hitachi 
Ham-Key  Ai fiance 


^o)  EnJiiX§S^^CP 


lOtlH 
.>*]rJIIJ 


ELECTHICAt- 

FiUH^dirlMiirl 

Fnvii  ^r.iHiii'|t  Hal  la 

Vf  .^  II    Irii  ih<iiiii^ir«J 

H4ll-»<iriw#i  MMih  I^4h1i  ■    ti^^" 

Innjcdui-Mt  'SQO*Wb| 


in<;rTi  I  "iiLllll 

LMii..iFtil  [lern«iil 

1  II I  I'll  III  i^JHIIIll 

M.iE■l^1lJT^l  ^mHf*t''  Ai*# 
WliHtl  LujEl  ■!  iD  UI^H 
WPiHhP 


rtwAIHiAj  

■■II  ^  «r  Urn  14 

turmM^  V»n    fH— *i   rHim  -  3  JBtBr  ,i%«m  »  I  P 

T*#  A  3  kfl  ■■»  kfl  mm_ni*a  Iuf  i^n^iif  M>l«f  ■ritiDi'..  tl^f  hii  nw%i4t«  «m  m* 

TWirii  itulll  i«i«*uh  m  npvahai  ^rBi«4H|.  #1  rmtUHTKr  ro"  hflHIJKIItiil  gpigf^ahtH' 
1«rt^  Nil  lUljirTM  rn>  HR-liiyn  VMK  l>X  A^kt  Jllddil-iatHi  bifl  ul  llta  *.  J  tC -Clfi 
M  HfNil  IklLtH]   Pai   i-rin  AltlCit  ^|I1  iM  4i4](ll   tD'badl   TllH 


mil. 

lU^il. 
7411. 
4  4  III,   II. 
niibn. 


fi'rv*''"''!  liniii 

f  ran-r  lit  H*  '  I^b't 

V  g  K  K    'iJt.l  lmi"irirrr  T    1    1 

HjlJI  I'ui4«l  flpj.-i  ft'.d:h  *Hr' 

i4«tw™ 


!ti'ECIFir:ATIfMI  -A  ?  IQ 
IViiiirn  3  -Pii^ili 

j    Mil..H~l     |:l*Flf»-l| 

I  i.M  .'^11  Flflrtll/I 

w,i-Hiii^/<i  Sur<*cr  Ar** 

wii4  juudi  di  au  vm* 


mjm\  1-1  tarOf^'gSr 


huM  aiNi^tMii  !■•  (ipiiiRiiini  pHfH-MMika  *n  kalti  bwHti  i^w  imS- 
0*|IE  f*^wn«Bi««  Ihw   n^  41  ii.ui     tii^.H  M      i^  4M  u^  *i'  <•■ 


^id  tiMiv 


Cr- 

Fr-  ■   n^^u 

ftflli  ri-i*.|i|  uhmi'i  HfVirh'i 
NlwiAinPiil  l*i'.iHi  J  sri.T'. 
E  f<iiii<+  >i  J      H  Pljfin 

^^a|i  11,^1  l'(i*,||^j|juiii- 
F  nuin<  m^    H  PlwiB 

■Ciici/Iai 

E-   hlilrib' 

BotHwhiii-Ii  IU  ■□  IMMttt 

kmpmanicr  ^  CNnni 

Mii(.i>»t4  fy^krw   AdfUBlatiir  Q-MMH 


fitlMIIJftJptt- 


or 

6J" 


■HCM  ■  TJIX- 

Fp»*  Miiuii 
.UiimnLirn  ^-urrscc  Ai«i 

WhI|#|I| 


,  a  i  N 

II  llii 


V9  It 


"il  i]*S  !n7ii©^^:^rp 


ii 

1  mHpf  i  J?'* 
Sif  |.  H  M    LQ  4  ^  .n*(*rd         '  ,    1   I   1 

B«>priwilllh  .     (I  miiiRr  t  BD  in  rH  M  M/ 

?Mitl«ii|  144  14  MFlMl-N/' 

Iriii^ilHllL^H  .B*^  ff^iiirii 

Moichmiqi  Hv^tiiiPi    Ad|i]EtJbni  Gmniiiii 


X  MTHi'nij  Ridura 
UBAipiiufftSurliav  A«4. 

^|rir|  I  iimi  Ki  ffl  UfH 


)fl  I  It 

tJlfn 
i:^  g  ihi 


ALtcrriiEU- 

FriTH^I  :n  Nafl   lilllfl 

W!i  W  R    \it  Fnini^incpl 
Hjtr  I'rrwfi  ll««ri  WirtPh  40 

Uand^iiliN  .  SPD  1.D  3  JEi  M  h*^ 

M^ifriiMHMUh  ...  .      aQ  Qhn^i 


A1  1J« 
HIChAMCju.^ 

h   ......   I  -r^h 

.  'JjrJiui. 

V  I'll  '.ml  .^.lrl^«  A.v« 
WViriil   I   hkP  Hl-aa  Wilff 

WnlUhl 


i  H 

4  3  It 

1  JJ  v.]   M 

t  ?  »  iht 
fl  itii 


SLINKVr  S43.95  Kit  A  LOT  ol  •r^t^nna 
in  a  LtTTLE  tpactt  New  a^irihv®dipcilfi'' 
whh  he  Heal  looking  rddjatas  a  good 
signoi  at  1/10  vwiM^kength  langl 


-^s^ffli  ^0  i^S^Ji^ 


^m  l^ri 


M  nn 


>«HLMk   ii!iL>l4l    (.«        ,4,,rt.,. 


This   efectficallv    smaM  80/75,  40 
£d    20    meter    antenna  operates   at 
|anv  length  from  2*3  to  70  ft.  •no 
e)^tta  baiuii  or  trsinsmBtch  n^^dad 
•  portable    -    ore^is    &    stores    in 
|minutB£  •  smaill  enoug^t   to  fit  in 
attic  or   apt-   •full    l«gal  power  • 
lOvv    SWR    over    complete    80/75, 
40    fir    20    m«ter    bands    •   much 
loi'u^r  atm'Osph^ic   notse  pick-up 
than  a  vertical  &  ne^'ds  no  radial^ 
^  kit  mcl,  3  pr.  of  spec^ially-rnade 
!4"     diai     bv    ^"    long    coils,    con- 
raining    335    fti^    of  radiating  con- 
Iductor^     taaJun,     50    ft     RG58/U 
coax,     P 1-259     connector,     nylon 
rope  &  manuaL 


HAM-KCY 


Model  HK-3M 


RADIO  TELEGRAPH 
SENDING  DEVICES 

Model  HK4 


f«fl95 


19 


'**«  »f^i 


I  Id  MlUlli   IH  I 


M<)>|Hl   AT   •  H#Tll  t^  Mflfl^F*  •I'V      MiUlllFP^.UlT  '^1^   ]   lis  ■'PR    JW 

13^ 


Model  HK^ 


ai  m** 


a  iB^  iBi  im  1  u  n 


HK.  J  M^  «c  HK  t  luP  itm  !■■■  Nt*  Jtt^nmamtamin 


Model  HK-5A 
Electronic  Keyer 


[:rimiiiri.i1>iii'r  Htt  1  Jl'  HK  'i  nn  iiii<T*  Imw 

^1'.«i^i<l   hav  rni^v  Ij^  ui^d   r  IJii  ivpi  r  icjingllv  ui  ukm  hvHCIi   MP  Vl^ljpr 
I  II1II14IIV 

I     I    II''  h  wiirird  rM-r  ii*i(»>  frt»«i  hn  M^  4  F^  M 


^7^<^«^] 


i»5 


*  UMI*  CuPt'll  Ba44  hlM»l  ePIip 
>  iMiluE  iiiiciFii  Pill  M]>iyiJi  bivuig      ■  firid  IH4^  or  durrt  kfyiriu 

'   SvM   CDIipaJPMI-U  Him  4  t<<^«ii  ■  I^MPRII.   ^-IplUlliH.  CDIM   Hi  •TilUtl 

'   D4»l  Hi   llMll  mini  [HI-  KIHIIhilli  nh  lirrani   ^fiirl 

'  Buill  i>T  l1lt»1ilHH  ■  Xifr  #<i1li  l-l'H,   1  or  KK   * 


$219.95 

MODEL FLt 

FreCiueciCV  —  Agile  Audio  Fihtir 
The  DatiOn!^  Froi^uoncy 'Agile  Audio  Filter  is 
intended  pnnsmWy  for  poEt-di^Tecrtcr  f^ignal 
fillerirHg  in  RF  and  LF  comniuniuiiont 
receivers  foi  SSB  and  CW.  It  otfeF^  an 
uniflualJv  irfi'Uiile  com^rurtion  of  benefitv 
til  tl^  uKf  rndcidrrtf- 

Fisf  Hie  SSS  CHicniEH: 

*  F^i  dutci^dipc  lupfP'ssBOfi  of  mtzifnixf^ 
hreterodyn«  wtiiitjei  iin  the  tm^qs  280- 
30O0  H;  by  a  unique  W4rdh-lock-j)nid- 
track  nutdh  (iltcf ,  Th*  frucking  notctt  cart 
be  left  in  circuit  with  no  audible  effect 
until  i  wJiistIf  appears  In  whicfi  case 
The  whistjfl  Will  'qJisappijaf'  within  tVPJ- 
iipjiv    one   urcatid, 

•  A  contmuouily  adjusiatjle  audio  'win- 
dow' Of  I  >driflt»te-widiti  noici^  to  im- 
prove reception  in  the  prie^me  oi  other 
otttu4w  S5B.  RTTY  or  5STV  li^nali. 

Fbf  the  CW  DpaTslcir : 

*  Cpntinuoui^v  nrtAtrie  ctfnlM'fmfuericv 
1280-3000  Hl^  ami  bafidwidth  12^ 
1000  Hjt  fcH  perfcci  rnatdhuii^  of  nec^wer 
psssband  io  dvan^g  band  conditktfii. 
sending  ipsfMfl^.  and  pertonai  preference. 

■  Flat-mpfped,  neep  skirted  rirsponte  ihtpe 
for  opiimum  c^ase  of  luning  canibLEi^ii 
with  eKceLltfnt  not&e  rejects  on. 

•  Linear  tuning  law  with  bindwirfth  inde- 
pendent Qf  frnqLicncy  ind  gain  indepen- 
dent of  hand  width  for  natyral  'fe^r, 


P.O.  Box 27,  Medford.Mossachusetts, 02155 


TEL.  1-617-391-3200 


TUFTS  Electronk  Department  Store.TUFTS 


JAN  EL 


LABORATORIES 


^Sf 


far  6  Metar  Ttanict^vms 


CLASSIC  2  METER  PREAMP 

figure  sciCMit  tm  Mi  ti^«|  Eairity  MCftcafcif  ^'  '  •      u 


QSA5  PREAMP 

For  Transceivers 


'^mtm^wic 


MODEL 

30PB 

bOPB 

b3PB 

I3^PB 

t44PB 

PM-1 

0SA5 

QSA6 

7?nPB 

^   JPA 

432PC 

<32PE 

PB 


DESCRIPTION  t*RJCE 
PREAMra 

B0-5?MHr|BNCI  5195 

62''S4  lylHHBNC)  21^95 

!3S-139MHiJHNC|  ^195 

1*4-148  MHz  IBNCI  ^t^B 

2ni  Prurnp  Moduk  { SokSttr  Teimii^Bhl  1 6  .QS 

t44  -  T*S  MHj  fof  Trtrrtonwi  (SO-  239)  4 1 5& 

S0-&?  M  Hr  rS0-238i  ^  *S 

220-335  MH2  jBMCJ  21-95 

4?O-450  MHj  {Emil  3  &  di  nwcm^tfrt  NF  33.00 

*2tM&0  MNi  tBNCI-  2.0  dB  mimmum  NF  54-^5 

1.0  dB  typical  NF  ».M 
Ariv  i^o^b  frtqu^ncy  bttwtw  30  »l4  ^p  Of  t4«-174  MH?  IBNCI        ?7jO0 

CONV/ERTERS 

144. 146  MHHN.  ^8-30  MHz  OUT  fBNC]  S  79,95 

3itd  cf vBtal  far  1 44CF  [  143-145  I M,  36-30  OUT)  t^J.OO 

433-134  MHz  IN.  ?S-30MHr  OUT  [BNC*  79J& 

amt  crvttBl  firr  433CP  1434^36  IN.  2S-30  DtTT)  \Qm 
lAlw  i^lftbl^  vviit^  434-436  MHf  11^  *n(l  3a-90  MHi  OliT,  jOicar  8. 

Mod«  J)  TQ^S 


IFatilM*«LJA  T»>- 

no  rnoolicaliciii  r. 

C4ntMfu»dwftl^rrt!tui*i^i»I3tfTiF  ^ 

tf  mates^  —  FM  SiB.  CW  or  AiJ  -  "  -  '-  - 

*,  licml  P9r)«l!  SWitt'''  flhTA-*.  n-e  preairnp  !|(>  Jjo  *iirp4s5iea 
■vi-i-  (•ec«TVThg   Thf  ju^ft  Qf  itm  OSA,  ^  p+n 

n-ii^LfN  lor  eKC.&p(»DnM.  -..■■i .......    The  gmti  r\*a  tie*ri  sot 

■o   apumi^fi    itiu    p(}FlQ*marice   wilh   2    mfltffi    [tan-B- 


Model  PM-1 


PREAMP  MODULE 

•'\'-' i'tsu  wm  rmtn  0*  •"  •*Mpi'«>i 

1^:^  ^  vt  lo  w«iit  Of  coai   Use*  to*  noe*  JAHEl 

MO^  ■  T  t*cti  i#Tii  IS  funy  f«fi9a  lo"  jmi  stki 

i^Do      ...        .  .  itii^iv  oricxs  me  awifiaBiM*  lof  OEM's 


e  METEI^  PREAMP 
Idea)  far  Dx 

■,"iw   rifn  '     ■  .     '  "f 

UcM^vt  5CP3  50  &2MH1.      Mo€tel  S3PB  £2-54liHi_ 


I4 ^^*"^ JP 

Vat  $  M«t«>t  Tnntc#i«#$ 


■'■♦  '*u,     Tit  3t 


ai    '.i^^'SJiMHz  (fc&TKLilv  wTien  tifderirttii    UHf    con 
Ill'     MudBl  OSA'9,  -.. ^ . 


f* 


10  METEfl  PREAMP 


17013 
IJOIO 
17014 

mms 

C3Q06 

IS0LIN£ 
43^FA 
431FA  2 


OICILLATORS 

Pr«*iMK>.  Speaty  4  ar  10  VMt 
10  to  1  Digital  Pnridif 

E^i.  10  (0  T  Dividen 
USEf  UL  ACCESSORIES 

BMC  (o  SNC.  36'  RG-58CAJ  CiW» 

GNC  IQ  UHF.  3B  '  RG-5BC/U  Z^\t 

BNCloRCAPht>nq,36"  RG'&flC/U  CihiB 

AclimtDr,  BNC  Pluo  to  UHF  Jack 

BNC  Connector,  UG-BS/U  far  RG-58  A»Ke  cablfi 

MISCELLANEOUS 

AAttnnd  iK^a^or.  144-U4  MHi  (Sd-2391 

Cittfty  Filter ^  .5  dS  ton 

C«wity  FtilET.  ^  ilB  misirnum  ios 


S  73.95 

11.9S 
21M 


^d)»^' 


■i«    **=^ 


Lt     rf^-  ■!. 


■-  ■       ■■  ''ix,-ti».  tNdc  lio'ft'e'  '-^jfTA]   gttJT  on 
MDdfrl  3CI  PB  2a  3UHHr 


220  MH£ 

[f  I    Low  Nolae  PToamp 


hAQ^ml  230FB. 


UMF  PREAMPS 

l|«l»l  432PA  4ao  4t)0UHz 

Low  Casi  All  AiDum}  Farvofit* 

■I'tcaljon^  Ujtn  t»  rno4tn»   1  TdB 

E-NfMn SI, aluminum ixsi  i\i4i{Z'.^. 
MDdBM^3PC  420  4BQMHj; 
Emrarnflly  SanBlllvfi 


80^ 


Our  finest  UHFPrvflfTiT^—I.CdB  HF 

TlHv  fJijl!-'  MHr  [Tr^iimp  : 


4rnp  pf 


I  !'?■*»  no[-SP 


>   _  -  _ . 


-    Li«_'    tr^  ^» 


fflri, 


tr 


Witf  iiipeci^  !**»» 


Wad«l  4  JZPE 


S65SS 


DAIWA 


Interference  Filters  from  J.  W.  Miller 


$20^5 


Coaxiar  Switches 

2  P«jsttfon/Modd  CS-201 

4  Position/Model  CS401 


nw-Am 


Si  35.95 


SWR  &  Power  Meters 

Models  Cfy  720.  CN-620  and  CN-630 

Pr  0  f Ksiona  11  y  «  nqt  n«4  t€dl  csv  1  ty  oonitruction . 

PtavfCT  Rating   2  SkW  PEP.  IkW  CW 

Irnpedancf:  50  Otimt 

CgmKCttiTt:  SO-233 

Inseition  Lfla:  Lro  than  2  dB 

VSWR:  1  1.2 

MaximuTtn  Ftfqueiuv'  500  MHr 

lujiation:   Detler  lh«n  BQ  dB  it  300  MHi. 

b#ii«r   ttian   45  dB  it  450  MHi;  MJjaCiem 

Tfrminal, 

Unused  Ternilrtal&  grouncfed, 


RF  Speech  Proc«$$or 
Mcidets  RF^OO 

Increases  talk  pcrwer  wilt^  &pilaner  free  Qp^a- 

tion.    RF    clipplrFg    assiurcs  Jaw  diitortifin. 

Simply     irtstnil    balween    micro  phone    and 

trammitter. 

Talk  Power:  Better  than  S  dB. 

Frtquencv  Rasponj*.  300-3000  Hi  ^t  12  dB 

<*ffwn. 

Dittoition:  Lm  than  3%  at  1  kHi,  20  dB 


CM -720  and  CN'620 

FrfrruCTCv  Rangie:  15-150  MHi 
SWR  Oeiection  Scniitlvltv:  5W  min. 
Power:  3  Rdnges  i Forward,  2O/200/1O0W) 
{RBtl&ctsd.4/40/200Wf 


Low  P3SS  Filters 


r ;!  1-1:1 1.:.:.  1  L^i  I  ^. 
■<iilJill«i  vn  Afit ' 


nl  If>  tV 

VS'  111 
]&iite<iv4l  UlNi# 


fig&o 


C  &l  t-T. »  «  Ml  M  «  FtrSEd 

c  sw-T  TOCO  «r  JUi  3BI0  «  TEf>  ssa 

High  Pass  Filters 

HmtxUed  III  th«  «n(«npi4,«4ir  I'j-ji  -<■ 
'■'  I  ^B4l4i<:«  liffi!  uruJ  GVfi'Usid  muf  Jn^nci 
iv  I  w'  171  ^M  t«zt'Tifti  zmnai  bv  anutmr 
fidiQ  frjinirTiiuiin  (imt  uihiri  hjuh  IrMiuantv        $10  IB 
tmita  iAlUKni    FlIllH  iMTl:tAI,rjiTflf  Mgnjli  biflo^       i-IO.IB 
4CI  MHz  b^  1  p(jfi«i<r  hiictnr  n''Mttii  thun 
i  0{W,1K»:1 .  IhiphJunck  C  SIJ-T  1 ;  ^,'300  yhm 


Audio  Interference  Filters 


l«r 


!  *t*Tr*a*"*<*»-  Ci 


W4K  t^lC?  CW  HI  vUi't^j  •i3rM*-=-'  if^^M 

AC  Power  Line  Filters 

t  lilTiinil^  u<  i»m!ul-I!  i-niililHiiirc[;r  ^^  r4d»Q 

iiiri'itNuE  iiM^-Mai-t,  fV'dimd  rjd-HJi,  jimi 
lit* 


§5  07 


f  IB  35 


1        $140.50 


CN*€20 


CN630 

Frettuencv  Riftge.  1 40-450  MHj? 
Piiw«r:2Hanges  IForward  2O/2O0W1 

(R«t4acted4/40W) 


CN-630 
S  139.00 


CN-720       $186.95 


P.O.  Box  27,  Medford,  Mossochusetts, 02155 


TEL. 1-617-391-3200 


TUFT S  Electronic  Department  Stor^.TUFTS 


Etectronk 


$99  VHF  model  4362  {T4o-i8o  w\hz\ 

$99     HF  model  4360  i  is-  30  mh^\ 
tlon 


'.  1    M*,J  HAM-MATE  D^reciit^ui  Wjit- 


iufm  it4  nr  rdlctl,c^d  pamft  m  SO-ohm  cmual 
liJrtUn'iMion  lihcL  Thci»  Jtc  dirKl  dcKjcrtdailti  of 
ih-^Jr(4j.  IHRULINE*  Wiltmeter  -  the 
:  rrul  U^>dJli]  (ill  the  mdtJItry— end  wvll 

4),«M^iiiel'V  rrwjaikHC'  ''"    ~    ■^«^  Jltnr  undtf  IIT^  ■{Kid 

-  J  wYtDEin  u'l  j>LM>nm  line,  »  mtjOJ^ic'  if  mtitg, 
...  ■  '-  -]fnf  ulatiTj-lfdl  in  vaiXi^  All  TmiunieiJ 
:  pUuic  hiMAini.  It  4  this  tvpe  of 
11  jnd  the  dhre^»n»l  TH  RU  L  ■  M 
,,„>^,..  ,K  .  '  ^^..:,  larilhiHiI  tartiid£,  itui  ICCQunt  ECir 
thr  %uprrK]nt>  ol  the  HAU  A4ATE  Winnvten. 


the  indispensable 


THRUUNE 
VWTIMETHI 


[■.  ij 


'MHii 


■LI'  ■mMti 


s<w 


WW. 


2<W 


500 


tvnr     wiuj 


MODEL  43 

ElemenTs  tTafate  tj  2-30  MHi 
Elemenri  (Table  1)  2&^1000  MH* 
Carrvir\9  case  for  Model  43  fit  6  ei^ments 
Carrymi}cas«  fc^r  12  et9m«r^tS 


$135  JOO 
50JOO 
42il0 

17II0 


READ  RF  WATTS  DIRECTLVf  {Specify  Type  N  or  S0239  coiv 
nectorsj  0.45  -  2300  MHz,  1-1 0,000  Watts  ^5%,  low  insertron  VSWR 
—  1*05»  UfiBcjuaHed  economy  and  fle:xibitity.  Suy  only  the  elemeriTf^y 
covering  your  present  ff^quencv  and  power  needs,  add  extra  ranges 
lafetf-  if  yotir  rflquirefrientv  expand. 


AMPHENOLi^ 

wi^tbjcfj^rtiof   e<()nn#iricifM    whlh  luva»#l   KTIbMI   tat 
duifli  dtKiiuieict  «ppLi(icil4ona. 

mccvrmteiy    nUi'hlJVfd  fram  hr*i».  Jtcttnu  iir  ltl»tk  'if 

p-J»tfi4C^')    I"     tivt     jptt    Gvn^cior*    t^AL    fl*n    l*M 

iitaruuiin 


BNC      BULKMEAU     ftECEP* 
TACLE    3I-Z3l-aH^  UO'IOB^ 
MpEcb    wlLh    «nr    UNC    plui 
H.«eepuele    CMTV    be    iTiLiunl«U 

JTi^ld  ];]An#hi  i(tf  1-1^  Ul4"  tttii^k. 

BNV  l,M>  TO  UHF  (F>  APAr^ 

Adiipu    lunv    RNC   141' It   ill  4111 
UHT  plu^.    t.l.KJI 

ijouBi.E  MATK  adapti;b 

iB3-B77';(M&       rfii-lli      fuuplln* 

[ti^cls     1£     f4*m.(i|p    rNimi>rini'THi 

$2.72 

JACK  AIIPATKH  »l.3b 

a'l-isp-^sb  to  M'vftifcti*  iifpf 

auiHi  asleniiM  jiirk  iir  pin  ]tif3(< 
CANFl.        RECKPTACLI: 

wlih     -I     fiiit-cncTi    w     JWaU'" 
djAmrtrr  holf  -  *(  .1  7 
rANEL       BECEPTACl.t: 


114C4Ft  TU  L1MF  {Ul  ADA:^- 
TEH  31 -Qj!)Ii-:in&  t'Ci^373 
Ad^u  Jinv  BKC!  {>>"»  ^"  »"* 
iMIl-'  lai^k.  t3.3W 

liJ-5»r'IB>  K*4ltJiF*  *n  urt 
Lhrrulrri,  k^iifi^V  ■hrlj  tM  pwili 
tit  im  friuhkl^  rnifiB+ftwn 
12.27 


lightning;       AHUE^lTOll 
^'i^-IO'VMSt  EiinuDAtF*  lUiic 
...  l-UD     fnziq    ABlf niiA.    ITtta 
irtii  TOUT  v«|iui'blf'  *qun»™'**i 
j^^Ajitit      iLsliuiifii      d<im*t<^ 

BNC    ]Pl.lli>    JJ40I'»ia    i'l> 
BS    C'lniilliiJnl^    uurd    Iin    rum 

ANC    JiTRAKil'IT    All  Am  ft 
)l-Sll-la.&    VG^II*    I    til'- 

BNC     rANEl.    HIEtErrACT-f: 
«ith     i    fMinm    lib    ^,44' 


iMta     KhsHmI  !€■«&    nutt  BT«- 

fl!*c     A!«fiLC     APAm:« 

ART   BSt:  piua  for  ndA  anglii' 

■  ?IC  TEt  AOArTKS 
11  *H  11 J  EJt^X?4  '\44^»  t 
BNC  plufB  111  3]-llW*lt&  4f 
4Cbrr  Ir»«J*  BMl!'  li'P* 


UU-SI»J^ 


n>rt77-a(iii 


ST]l-l(l'3+;;tflh 


J»1M 


'S7a 


H:3.D»^r•:i^^ 


i^a-itt^-JAi 


Ui#^« 


First  ts  ihe  FoK  XK.  It  reads  all 
baridsdnd  Tucks  away  an  (.he  visor. 


Our  remote  (BW)  ijrut  is  "ouf -of- 
'  '"tormafiCf'.loo. 


llt^-271 


P.O.  Box  27, 


Jliul  now  there's  Sup^ioxl 

jdAr  ^  J  system  -  Supedqi  has  10 

1 1  fiw*  the  aensiHvity  capabiJiiy  i3f  any 
..■  .  ' '.;>S'^  &  is  idetil 

iftatjisjiatiofis. 


PRICE  LIST 

Descfiptlon  pfi« 

Fox  XK 

All  band  detKtnr  w/ietf 
contained  •uri}/yi»J»l  aiwm  stQ9  0Q 

Foix  XK  tnwi 

All  band  detectof  w/remote 
conlTol,  watef  proof  $l39in 

Super  FoK 

Supvr  Hetef  odyne  rwnnte 

iBdv  wvntngsvsatit  $279.9^ 


HJTACHI 
OSCILLOSCOPES 

SPCCiALl 

15%  OFF  ALL 

HITACHI  SCOPES 


o 


V      --^ 


SinglB  and  dual  tr«:e.  15  Ami  30  MHj.  AiF 
lour  hig»i  «en»JtivtiY  H»iadhi  QMiiM0]£Dp<n 
ve  by  lit  ta  demandifig  HttKhi  iquslity  tt«o 
(ftarcb  »nd  «rv  bic^ed  by  ■  f-v^lf  w^rrjntv- 
TTiev're  ital«  to  me»yr«  ugn^H  at  lew  JS 
1(nV/cl4vi$i€ir«  Niiti  X§  vertiCdJ  rriapiifierl. 
ti'^t  1  fptcificatiDin  y<Ht  won't  find  on  Any 
cnKtr  IS  or  30  MHi  wopt.  Ptut-  2-«xit 
modutiatMsn,  trace  rouiion.  frcMit  ptfmi  K-Y 
aperatian  for  bU  tuur  tcdpe  medeH,  tfid  XtO 
sweep  niagi^4lif:jthyi.  And.  tiolh  30  MHf 
cturiikKcapei  off«r  iriternal  tifniA  detav  lirKf, 
For  SAW  of  operilktn,  Function«rtv  relate 
conTroh  jrt  grouped  >nto  three  blockt  on 
the  cctlor  cmted  Iront  pan«L 

•  V-302  30  MHz  Dual  Trace  S95O30 

•  V -301  30  MHz  Single  Tiace  SfiTOSO 

•  V*152  15  MHzDMatTface  $625^5 

•  V-151  IS  MHz  Single  TtMX  $490.50 


ALLIANCE 


$119.95 

HD  73  HEAVY  DUTV 
ROTATOR 

with  exclusive  Duel-Speed  Control! 

For  antenrus  up  tQ  10.7  sq-  Tt.  cif  wiod  load 
Het.  Mast  support  tiracfcet  dntgn  permits 
eatv  centering:  and  offers  a  positive  dfive 
no-siip  Opliofi,  Automatic  brake  action 
cushion j  stops  to  r^uce  inertia  Ftressei 
Unique  conttol  unit  Iwturcs  DUAL  SPEED 
rotatkin  wiih  one  fiwe-position  switch. 
SPECIFICATIONS;  Max.  wind  load  faending 
mofnent  10.000  irr-libs.  (w^de-thrn&t  OVH'- 
lurmngli,  Btarting  torque— 400  ifl.-lbs.: 
Hardened  Meet  drive  geaf^;  Bearingi  — 
too  3/8"  dwiTi«ter  f hardened k  (WeiM  - 
D'Ar^Oftwal.  raut  h^nd  Ihack-ligtitedl.Tbere's 
much,  much  mote. 


Two  NEW  Rotors 
from  Comell-Dubilier 


TAILTWiSTERT 


M 


HAM  IV 


■  For  the  New  Super 

Com  mun  teat  ions  Antennas 

■  New  Thickwall  Castmg 

■  New  Steel  Ring  Gear 

■  New  Metal  Pinion  Gear 

■  New  Motor  Prebrake 

■  New  Super  Wed^e  Br^ke 

■  New  L.e,D.  Control  Box 

■  Sale  26  Volt  Operation 
Oe$igrb^cl    Ipr    tl^o   newest   Of    the 
kir^-size    com munjcat tons    anten- 
nas, the  TAIL  TWISTERTM  ^^  ^^^ 

ultimate  in  antenna  rotatiorial 
devices.  Th«  TAIL  TWfSTER^^^ 
starts  with  a  deluxe  control  boK 
featuring  $nap  ^ lion  controls  for 
Jbr^ke  and  directional  COfitfOlS. 
I_E,0.  infljcdtors  signal  rot^ation 
^nd  brake  op^rdtion,  while  the 
illuminated  fn*ter  provides  dJroc 
tion  readout.  This  new  control 
bo^  couples  to  ttie  newest  bell 
rotor.  Using  the  time  tested  betl 
rotof  Principle,  the  TAl  L  TWIST 
gpTM  J5  a  brand  new  detifin  with 
fhickwall  cBfttings  and  six  bolt 
assembly  A  brand  new  motor 
with  prebrake  action  brings  the 
antenna  ^ystemi  to  an  easy  stop, 
•  lie  the  maisive  square  front 
brake  we<l!9e  locks  the  asserr^bly  in 
place.  A  new  ^tiiiniess  steel  spur 
^ear    sv*^'p"^    provid*?^   finat    drive 


into  a  new  steel  ring  gear  for  total 
reliability.  Triple  race,  138  tialt 
bearing  asMmbly  carries  dead 
weighl  and.  maintains  horizontal 
stability. 

An     optional     heavy    duty     lower 
mast  adaptor  is  available  for  light 
er      loads     with      mast     mountirig. 

Price:  S249.00 


The  HAM  iV  sets  new  leveis  of 
pert  or  man  ce.  Snap  action 
switched  wedge  brake  and  rota- 
tional controls  things  pinpoint 
accuracy  to  large  directional  ar 
ray*  popular  in  comrnunications. 
A  new  motor  provides  pre-brake 
action  to  a^i^  in  slowing  down 
rotational  mass,  anii  the  new 
thicker  wedge  brake  offers  far 
stronger  lock- in  phase  action.  To 
take  full  advantage  of  this  new 
design,  the  HAM  111  is  designed 
for  in- tower  mounting.  A  new 
Optionail  heavy  duty  lower  m,ast 
adaptor  is  available  when  lh« 
HAM  111  is  to  be  mast  mounted 
with  sfnaliBT  arrays.  A  stainless 
steel  soiur  gear  system  myltipliei 
the  torqfue  into  the  dual  race  98 
ball  bearing  support  assembliv 
assuring  years  of  trouble  free  per 
tor  mane  e.  F^rice:  SI  69.00 


ord,  Massachusetts, 02155 


TEL. 1-617-391-3200 


TUFTS  Electronic  Department  Store.TUFTS 


NEW! 


HFJ  INTROEnJCES  THE 


GRANDMASTER 

MEMORY  KEYERS 

At  $139.95  this  MFJ-484  GRANDMASTER 

memory  keyer  gives  you  mor^  features  per  doiar  tfian  iny  other 
memQi7  Keyer  availabla  -  and  Here's  Why  ,  . , 


A  AMU  ■  *ff  1  i.9i  Fmr 


1€ 


wrriii  3iu(T  itsHED  n 


■•41  4w    hfti   m 


LliH   j<|i  •WW  WHICH 

MLMiHty  t;;  in  u:iF  tmu 
WiUM  ir  Cwg 


4^41  11'  1li>4l 


¥[||iiH(    CM 


ptLir  HWAT  numiiiL 

|U  1{1  t  KHWlilil   riAL 
rw  lAUm  H  If  AT 


LEfi  INI3CA  tFli 
DtL*.¥  Hin.A1 
MOOf 


i,j«  lam 


■riicT    njv 

"if t  II  « fn  tit  tt\w>t  y : 

1  r*    .•    ti   i;    !■  I  ;!r  1 1. 

■Ill 

t  mtn  vim  nio  i"i  m 

W    ifb    CiiAll^CIM'i    MY 


MEMORY KEYERS 

MFJ-4S4  Grdndma^Epr  Mttrndry  Kay«r   Up  to  twelve  25  chDracter 

me^aagos  plus  a  100^  7B,  iSO,  or  26  chsracter  fnessdge. 
Mf^  J-4B3  Grandmaiitfr  Mdmdi'y  Kfltfer.  Four  25  or  a  50  and  iwo 

2&c:harBc!«r  memgn, 
MFJ-^QI  Grandm^ter  Mernory  K#yl|f,Twa  50 characrter  mesagH;. 

HK-I  OplFonal  SauM/i  K«y. 

PROFESSOR  MORSE 

MFJ-4  \Q  Prafeswr  Morw»  BsfKhirTi  code  Qeneralor/kever.  Mothi  codt 

teactiing  computer  Smck  ilpha  only  or  alphanumeric, 
full  iw^tuT^  CiMtn  Ktvur.  ip^id  reickiut,  delay  for 
5pa:J4lf  liTlvri  up  to  Itittm  vconds, 

TELEPHONE  PATCHES 

MfJ-^24  Cfitp  ckai  profKxioiHt  foundinfl  iucfo,  Vu  n}«ler  fof 

moniiDfiAg  Ur%m  J«vtl  tri4  for  rajfHng  for  maKtimufn  wparaDon 
of  nansfnttiH  ami  i«e*iwr.  t^xy  palch  in  faodi  ixjt 


13SJ5 

99.95 
79J5 
39.95 


149,9^ 


MFj-620 


Same  m  liFJ'£34  tHcvm  wttioyl  nwier 


59^S 
49.9S 


$ 


29 


95 


MFJ  40T  ORP  Transmitter 

MISCELLANEOUS 

MFJ  302  RF  Nofse  Bridgv. 

R&ceivnr  Pr^itiaclor, 
Frequency  5Tiri.diifd. 
QHPTmrimiTTflr, 
CompDnion  QRP  VFO  fpr  40T 
Code  PracltcD  OlClFlator 
Optional  Tfllagfiiph  Kty, 


MFJ.1030BX 
MFJ^2Q0BX 

MFJ-40T 
MFJ-40y 
CPO-S55 
TK-555 


§9.95 
49.95 

?9,&b 

2^.95 

17.95 

1  MB 


95 


LS*-523KX 


Ui^-»«IBJf    U 


SPEECH  PROCESSOR 

MFJ.62S  filF  Spe#cti  Proceaor,  PNigi  betwrtcnmicrofihoiw  arHJt 

rig,  Powwrful  nttwi^  iogndint}  cp^ech   Vu  meter 
toi  vJiMstrrvent  of  proc»»ing^  4  put  mc  jack.  6  dB 
mar#  jw^gt  SS9  powif,  iis«  #ith  anv  rig  vid  any 
mic,  push  button  xm-^iffbfjaia, 

Logarrilbmic  S|H*d^  f^ocnior.  De^u^e  model. 
LcHprhNmic  Speed)  Piactmot. 


t.$P-520BX  It 
LSP-S20BX 


119  95 

S9JS 
4955 


$ 


54 


95 


CMOS  6043  Electronic  Keyer 

Sill*    «rt    the    art    de&ign    UB«4    CUflTISreO'S 


WPW:    «  SmeltinE    wid    stfMi^r*     *  Sp<i«cl      tV^ 

u"-       ■    ----   *eigFm  cnmrtrru     #  ttijf*  tiBHiiiUn*  ^Lrina 

^«,,t,^,    Um    TUHt     Off      Ot«      !=iMTOPyE    OFf 

#    i  1  i^'i    J     :  il^n'  •  QtiT     C  pl  I  ^       *    *    J     1  <  <     *      li  1  ■  4     *     * 
I  ■  i    '  I  ■  ■ 


ELECTRONIC  KEYERS 

MFJ-fi044tC      DetuJd!  KBycr.  Dctx  d^ddlth  memory. 

Econ^  Key«r.  BuJh-m  pa<fdle,  plus  exrras, 

Econ^  Kcyer.  Buitl-iri  padded. 

Eco r>D  Knyer.  Ekl^rriiil  Ki^y. 

New  Deluhe  Elffetroruic  II,  ipeed  readout  meier,  sockei  for 

MefFtcfv.  random  codo  ^nsrator,  keyt»osrcf  B044IC  heyer 

chip  do!  and  dash  nwrriory .  Up  to  50  WPM, 

Bencher  Deluxe  Iambic  Paddla.  Heavy  ^teel  ba^^  non^kt 

feet. 


MFJ-404 
MFJ^402 
MFJ-40a 
MFJ'40a 


BY-1 


60.95 
59  J  5 
44.96 

49.gs 


79.95 
39  g& 


MFJ  ENTERPRISES 

DELUXE 

Versa  Tuner  I 


^FJ-9S4 

(ytFJ-982 
MFJ-t&l 

MFJ-SeO 
MFJ-962 

MFj-9ei 

MFJ-949 

MFJ-g41B 

MFi-MO 

"^0-0014 
MFJ-945 

MFj-944 

MFJ-d43 

MFJ-901 

MFJ-1601D 


Onlum  3k W  Verw  Tunar  IV.  SWR,fcirwartf'raf1ucif^:J 

wattmuiflr,  rf  sirnrnatBr,  dumTnv  load,  an  tan  n a  swUch,  be^n, 

3kW  PEP 

3kW  V*rja  Tuner  IV,  7  portion  anlenr>a  switch^  balun. 

3kW  PEP 

3k W  Versa  Tuner  IV.  SWR.  fo7ward-r«f4eaed  watimeiar, 

balun.  3kW  PES* 

3kW  Vera  Tyn»r  IV.  BuMin  twtujn,  3kW  PEP 

1 .5  kW  Viri*  Tunir  III  SWR,  fornhrvd-f eflected  «raitmattr, 

B  PQiitiori  4Rttnn«  twitch,  baltm,  1  ,EkW  PEP 

IStiWV  V«tli  Tunit  III.  6  positron  antenna  nvilch. 

bolun  for  tulaneed  imt%,  1  ^W  PEF 

Oeltine  VefU  Tuner  IF,  Ullimate  in  antenna  tuncfs:  SMR, 

dununy  load,  forward  i^efleciEd  wattnwtef .  front  pamel 

onlenfta  iMritdi,  balum,  3O0W  cKttptrt. 

Vem  Tun«r  11.  ImprcrvKd  model  with  SmBfrnanm^ur^ 

anlffnr^a  fwntch^  iMltjn^  rnd^te  rmxirrting  1ir«:)t«t. 

300W  output 

V«ru  Tunet  IL  SWR/wjEnrnetEr.  antimva  iwilxti.  no 

tdlun,AOinob^le  mount.  3QSMi. 

Mo/tnit  iTUuril  lot  MFi-lMO 

Versa  TufMN  II   Wrth  SWRAaqttmetef  »vd  mobile  mOionlinf 

brackei,  lev  5  position  antenna  smritch,  30nW 

Veru  Turwr  M.  W>ih  im^nna  switch  and  m^biia  mounting 

liTMckvi.  Itn  SWR/Wfttmeter,  3Q0W  Duput 

Veru  Tuner  M.  Leu  SWR/wsttmptef.  an^nna  nvilch 

mpMnting  bracket,  3O0W  output 

Versa  Tunef ,  Mitchet  anythmg^  CoaK.,  lan^m  wires, 

balance  linet.  200W  output. 

Econo  Jyiwr.  MetcheK  eaax  and  r^r^dom  wires.  2O0W 

Random  W^r*  Tun#r  Fcjf  rendom  and  long  vnrea.  200W 


299.95 

199.95 

1 99  9& 
f69  9S 

te9.95 

149  95 

129.95 

79-95 

89S5 
3i30 

69J99 

69^95 

59.95 

49  J5 
39.95 
2995 


24-HOUR  DIGITAL  CLOCK 
SOLID-STATE 


8:53 


V 


29 


95 


24  HOUR  DIGITAL  CLOCK 

MFJ-101  24  tioMT  ar^itMl  dodi,  totallv  icitid  stal#«  .6"  b^m 

difpLfly  tl^ke  T&-€30S^.  lO  time,  lode  ivn&nm 
(ptVMRti  jKxideniil  mroetfing  of  timeL 


29-95 


THeu  MFi  Kivfi  men  vt  the  iml 


la  biduslri, 
if-wflrm  mm 


m  *  I 


>fV*  I 


SSB/CW  FILTERS 


MFi-752 
MFJ-751 
MFJ-721 

MFJ- 7  20 

CWF-2BX 
SBF-3BX 

AC  Ad  a  pier 
CWF-2PC 

SBF-2PC 

AC  Adapter 


Dual  mnable  SSB/CW  active  filter  Signal  inHsncer  II. 

2  fioiHj  limder*.  in  pun  for  2  ncp,  1 10  VAC  or  12  VOC 

Tunable  SSBfON  activ*  filter  Sigrtal  Enhancer. 

1  lOVAC  or  12  VDC, 

Super  CW/SSB  FlUtr.  2W  ^mpjifj^r,  noiie  limlterv, 

in  puis  ftjr  2  rigs,  12VDC  or  110VAC  with  optiorval 

AC  3cJat>ter. 

Ofltuj<e  Sun«r  CW  Fiftpr.  2W  flmpnfier.  12V DC  or 

1  lOVAC  with  Dptbnjil  AC  adapter. 

Sup«!r  CW  FJltir 

Sin^|#  Sideband  Fifttr 

12VDa20QmA. 

Same  wired  and  taiitMl  PC  board  as  m  CWF-2BX 

witti  4  petition  fWitc^ 

Same  wired  end  leited  FC  board  a*  in  SBF-2BX  with 

4  pctitiion  fWitch 

6  VDC,  30O  mA, 


79.96 
59.95 

69.95 

44  95 

29,95 

29.95 

7-95 

)9JS 

10.95 
7  95 


P.O.  Box  27,  Medford, Massachusetts, 02155 


Til.  1-617-391-3200 


TUFTS  Electronk  Department  StoreJTUFTS 


ORDER  BLANK 


lEIactronic  Department  Stora 

OPEN  DAILY  9-9  ^06  Mystic  Ave.,  Mectford,  Mass.,  02155,  TeL  1-617-391-3200 

SATURDAY  9-6 


Prices  FOB  Medford, 
Mass.  Mass.  reside rtts 
add  5%  fales  ta)c. 

Minimum  $3.60  for 
shipping  ^nd  handling 
on  all  orders. 


CAT. 

NO. 

PAGE 

NO. 

DESCRIPTION 

QUANTITY 

ORDERED 

UNIT 

PRICE 

TOTAL 

PRICE 

Nama  _ 

Addr€£ 
City  _ 

D  Chi 

Card  m 
Signatu 

Catt 

5%  Sales  Tax 

(Mass.  Residents) 

Stutft                       Zip 
BCk  Enclosed       D   Visa       LJ   Mastaf  Charge 

PRICES  SUBJECT  TO  CHAMGE  WITHOUT  hlOTICi 
j_                                                                     „     _  „,  Card  exD.  date 

Shipping 
and  Handling 

Min. 

Amount 
Enclosed 

ra 

SPECIAL  PRICING  NOTICE 

Many  of  the  major  items,  such  as  transceivers,  are  avattalbe  at  special  dtscoynt  prices.  A  complete  list  of  these  special 
discount  prices  may  be  obtained  by  writing  or  calling  our  mail  order  department.  If  your  order  contains  one  of  the 

items  on  the  current  discount  list  our  sales  staff  will  make  sure  thatyou  receive  the  lower  prices. 


BANDPASS-REJECT  DUPLEXER 
DPLA-144  PQH  144-174  MHz 

Alfo  jvallabre  for 
94,  220,  450  MHz, 


S499 


WACOM 


These  Band  Pass  Band  Reject  Cfr> 
cult  dupieKfrfs  include  the  use  of  an 
exclusive  circuit  devQiopeti  for 
WACOM,  which  provides  superior 
suppres$fon  of  spurious  sideband 
noise  Detween  and  adjacent  to  the 
duplex  freQuencles^  Wheiii  used  with 
a  h^gh  Q  firter,  the  Band  Pass  Band 
Reject  Circuit  provides  frequency 
response  curves  with  handpass  cavi* 
ty  characteristics  at  the  frequency 
to  be  passed  and  band-reject  cavity 
characteristics  at  the  frequency  to 
be  attenuated. 


SPECIAL! 

15%  OFF  ALL 

HITACHI  SCOPES 


M»Ji 


M 


'n'  am® 
-^^^^ 

HIT  ACH I  pg^QSCOPES 

Single  Jnd  ilgL^«^^15  9k1  30  MHz  All 
four    hjate>^^4<vri>r    HiiAd^i   iticilUnicoiT^ 

-2'ti\  ami  i'i^  h*;><-«!  l»v  a  2  ve4*  wiiraiit^ 
Tr>«v're  Mi*t  lo  rnficurt  $i9ni»l3   «  krw  *-i 

It's    i    ipeCitiFAlUMlf    VCkJ    MKVt'l    Ftftd   OTI   HOny 

DTlwi  IS  CM  30  MH/  icope.  Piut  Z  iUt% 
moduijtiOiT.  %9j£w  fCiuriori.  ftont  paml  X-Y 
DiMv^ri^n  for  d)ll  to«it  urope  modcH,  atvti  X10 
sweep  fTfagnifititio^  Ai^,  hoth  3(J  MHf 
crsoltofcourt  otfrr  rini*fna^  \mn3t*  rf^fav  f'^p* 

-  V-^02  30  MHz  DuaJ  Trace   SSSOJSO 

-  V<»1  30  MHj£Sin0eTi3Cfi$fi7O5O 
*  V-152  15  MMi  Dual  Trace   $625^5 

-  V451  1&  MHz  Single  Trace  $4903/3 


Mndi-ITA^S 


'rk# 


K> 


•  AK  60    m^st    plate   ad 
SI  4.50 


apier     —  *  Model     CL-36,     €    elerrterif^ 
S392.7& 


Moilet  MPK-3,   7500  Watts  AM/ 


Model    CL'203.    3    €*emepts    - 


CW  and  200O  Watts  P.E.P.  SSB  -  ^^-.  ^^ 

S67.75  $290.00 

^  Model     TA-36,     6    elements     -  •Mode*   TA-40    KR    —    40  meter 

$392,75  convei'sion  kit  -  $t  19.50 


SPECIALI  25%  OFF  ALL  WOSLEY  ANTENNAS, 


1^77 


P.O.  Box  27,  Medford,  Massachusetts, 02155 


TEL.  1-617-391-3200 


Feier  A  Smk  K20AW 

TO  Box  209 

Ml  Kisco  NV  WS49 


Build  a  Talking  Digital  IDer 

K20AW  redesigns  his  IDer  at  last 


When  my  CW  identifi- 
er and  repeater  con- 
trol circuit  article  appeared 
in  the  February  and  March. 
1973,  issues  of  7 J  Magazine, 
I  thought  that  those  circuits 
were  about  as  modern  and 
simple  as  they  could  get. 
Over  the  years,  I've  heard 
of  printed  circuit  boards 
and  kits  being  sold  at  ham- 
fests,  and  several  ham  re- 
peater manufacturers  have 


used  the  CW  identifier  cir- 
cuit in  their  systems.  The 
identifier  also  has  been 
used  in  RTTY  stations  to 
provide  Morse  code  identi- 
fication. 

But  times  do  change;  sev- 
eral articles  have  appeared 

in  73  Magazine  giving  cir- 
cuits which  modified  or  ex- 
panded the  original  design. 
I  finally  decided  that  it  was 


time  for  a  new  identifier  de- 
sign. 

Here  is  an  identifier  cir- 
cuit which  should  renew  in- 
terest in  identifiers  for  a 
while  It  uses  six  ICs.  the 
same  as  the  1973  version, 
but  this  identifier  talks. 

Yes,  you  read  It  right  It 
doesn't  whistle  or  hum  your 
call  — it  says  it  right  out 
loud,   in   plain   English,   for 

the  whole  world  to  hear.  A 


Photo  A.  Talking  identifier 


little  muffled,  perhaps  (af- 
ter all,  what  can  you  expect 
from  six  commonly-avail- 
able ICs?I  but  clear  enough 
to  understand. 

I'm  having  some  fun  with 
mine  right  now.  It's  sitting 
on  my  office  desk  (with  a  lit- 
tle IC  timer  setting  it  off 
about  once  a  minute)  quiet- 
ly mumbling  "Bah,  hum- 
bugT'  to  anyone  within  ear- 
shot! 

Although  it  makes  a 
great  conversation  piece, 
that  is  not  its  main  purpose. 
J  started  designing  this  iden- 
tif  ier  while  driving  on  a  long 
vacation  trip  last  summer. 
Every  half  hour  or  so,  I 
would  remember  to  key  up 
my  2-meter  rig  on  .52,  hop- 
ing that  somebody  would 
come  back  In  the  mean- 
time, a  hundred  hams  could 
have  passed  me  by  going  in 
the  opposite  direction.  But 
unless  I  picked  up  the  mike 
and  gave  my  call  every  min- 
ute or  two,  the  chances  of 
either  one  of  us  knowing 
about  the  other  were  slim. 
Wouldn't  »t  be  nice  (1 
thought)  to  have  an  auto- 
matic IDer  which  would 
key  up  the  rig  every  minute 
or  so  and  announce  itself? 
If  there  were  anybody 
around,  they  surely  would 


162     73  Magazine  *  December,  1980 


PUNCH  THROUGH 

WITH  THE 

STRONGEST,  CLEAREST 
SIGNAL  POSSIBLE! 

NEW  from 


3OUNQPOWED 


i?o  SPEECH  PROCESSOR 

Uses  new  technique  in  speech  processing.  Multiplies 
effective  voice  power  over  10  times.  Features  easy 

instaifation^  Switch  for  nurmai  or  processor 
opefatron .  Adjustments  for  gain  and  OLtpjt  level .  One 
year  manufacturer  warranty.  Patent  Pen  dug 


10X?SK' 


79 


NEW  HI-POWER 
MODEL  SP-100 

complele  wth  Mrc  and  POWER  CONN FC TORS 

PS9  Optional  AC  Powsr  Supply 

Add  3.00  Shipping  &  Handling 

ORDER  DIRECT  FROM 


95 


5.95 


t^360 


17  CLINTON  PARK  DRIVE 
BERGENFIELD,  N  J,  07621 


I 
I 
I 
I 
I 
I 
I 
I 
I 

I 
I 


f 


^^79 


OUR  NEW  BANDPASS- 
REJECT  DUPLEXERS  WITH 
OUR  EXCLUSIVE 

BpBr  CIRCUIT* 

,  ,  ,  provides  superior  perfor- 
mance, especially  at  close 

frequency  spacing. 

Models  available  for  all  Ham 
bands.  Special  price  for 
Amateur  Repeater  Clubs 

CALL  OB  WRITE  FOR  DETAILS: 


WACOM  PRODUCTS JNC 

p.   O,    Box   7127 
Waco.  Te^as  76710 
817/848-4435  .^79 


[handbook 


EQ  ^^Sk 


The  TEN  METER 

FM 

HANDBOOK 


$4.95 
postage 

add  50' 


Describing  the  fascinating 
happening   on  10  ^  FM! 


TEN  METER 
TRANSCEIVER 


FM  - 


t^-^J^JJ^ 


i'^J-J:  I  ' 


'^««..c 


-,--^'- 


#«*JP 


■K-^= 


■  V>.f 


Kii  inciytie!!  a  Iwud  colo^,  5ilk  screened  aluminum 
chassis.  \h&  delyice  CYBERNET  (Hy  Garni  CB  boafd.  True 
FM  di scrim maiQr  htt  crystal,  jacks,  pois,  nafciwftre  and  a 
Ihorougn  inairuction  manual 

COMPLETE  KIT  •$55. 

Intiliidt]  $2.CK)  tot  pc}siage!^nd  handlinQ. 
IH.  fesHdenls  add  5"o  sales  tax 


MELCO 


^  365     p  o    Box  26 

Mars&sa,  \\\    62257 


The  One-SEop  Paris  House  for  IQ  FM^ 


FAST  SCAIM  AMATEUR  TELEVISIOM  PRODUCTS  FOR 
THE  420-^450  MHZ  BAND 


*ATV  REPtATER 
Model  I570B-O  complete  system  with  filters 
ready  to  connect  to  antennos 


*ATV  REPEATER  ANTENNA- a  duo!  ontenna  system,  omnidirectionol, 
vertkal  polarization 


*ATV  TRANSCEIVERS 
Model  TXR  ISA- 15  watt  peak  output,  audio  subcarrier,  2  frequency  crysfol  controlled  receiving  converter 
Model  TXR15T"15  watt  peak  output,  audio  subcarrier,  tuneable  receiving  converter 


*ATV  TRANSMITTER 
Model  TX  ISA-  15  watt  peak  output,  audro  subcarrier 


•  IN-LINE  DETECTOR 
Model  XD  25C-  monitor  your  actual  transmitted 
picture 


*ATV  RECEIVING  CONVERTERS                                                I  *AUDlO-VIDEO  DEMODULATOR 
Modet  TR  70A-  tuneable  420-450  MHi                          I    Model  TD  lOOA-  connect  a  converter,  speaker,  and 
Model  XR  70A- crystal  controlled^  single  frequency  I     video  monitor  and  you  have  a  commercial  quality 
Model  XR  70B- crystal  contrpned,  dual  frequency     |    receiving  system 


I  ^TELEVISION  HANDBOOK  FOR  THE  AMATEUR* 


ANTENNAS- 48  and  88  element  models     T 


I  »COMBLINE  end  INTERDIGITAL  FILTERS-  for   repeater  and  base  stotion  use 


EVERY  APTRON  ATV  PRODUCT  IS, ,. . 


COMPLETE,  FACTORY  ASSEMBLED  AND  TESTED... 

PROVIDES  COMMERCIAL  QUALITY  COLOR   PERFORMANCE... 

SOLD  WITH  A  30  DAY  SATISFACTION  OR   MONEY  BACK  GUARANTEE- 

AND  A  ONE  YEAR  WARRANTY 


FOR  INFORMATION  CALL 

APTRON 


OR  WRITE  TO- 


k'S 


BLOOIVllNGTaN 
ll\IDIAIMA,47aaS 


hear  me.  And  voilS  — neces- 
sity was  the  mother  of  in- 
vention. 

The  identifier  uses  an 
EPROM  (Erasable  Pro- 
grammable Read  Only 
Memory)  to  store  the  voice 
data  to  be  spoken.  The  se- 
cret, of  course,  is  in  know- 
ing how  to  program  this 
EPROM.  I  do  the  program- 
ming on  my  SWTP  6800 
computer  system,  but  it 
could  be  done  on  another 
computer  just  as  well.  This 
article  includes  the  pro- 
grams and  a  PC  board  lay- 
out to  make  your  job  easier. 
(Etched  and  drilled  PC 
Boards  as  well  as  prepro- 
grammed EPROMs  are 
available  from  Star-Kits,  PO 
Box  209,  Mt.  Kisco  NY 
10549J 

How  It  Works 

There  are  many  ways 
either  to  store  a  real  sound 
recording  in  a  digital  mem- 
ory or  to  synthesize  a  fake 
voice.  Quite  a  few  voice 
synthesizers  are  available 
today,  ranging  from  the 
Texas  Instruments  Speak 
and  Spell^^  to  the  Compy- 
talker  synthesizer  available 
for  S-100  computers  and 
the  Radio  Shack  synthe- 
sizer for  the  TRS-80.  Unfor- 
tunately, most  of  these  are 
fairly  complex,  require 
some  custom- integrated 
[and  often  secret}  circuits, 
and  are  difficult  to  pro- 
gram. 

Simply  storing  a  digital 
image  of  a  real  voice  and 
playing  it  back  from  mem- 
ory turns  out  to  be  much 
easier  and  cheaper.  That  is 
how  this  identifier  works. 
Its  EPROM  contains  a  digi- 
tized ''recording"  of  a  voice 
[which  had  been  digitized 
previously  on  a  computer), 
and  a  fairly  simple  circuit 
then  scans  the  memory  and 
"plays"  it  back.  The  only 
problem  is  to  store  the 
voice  recording  in  such  a 
way  that  it  doesn't  exceed 
the  capacity  of  the  EPROM. 

If  memory  capacity  were 
not  a  problem,  then  the 
voice    pattern    could    be 


stored  with  voice  fidelity 
better  than  any  commercial 
hi-fi  recording.  In  fact,  digi- 
tal stereo  recording  is  the 
latest  technique  on  the  hi-fi 
scene  because  it  can  pro- 
vide frequency  response 
and  distortion  figures  be- 
yond anyone's  wildest 
dreams  of  just  a  few  years 
ago.  But  there  i^  a  price 
to  be  paid  — very  large 
amounts  of  digital  data  are 
involved.  Digital  recording 
often  is  done  with  video- 
tape recorders  which  can 
record  and  play  back  mil- 
lions of  bits  per  second. 
Squeezing  two  seconds 
worth  of  voice  into  an 
EPROM  which  contains  just 
16,384  bits  obviously  re- 
quires some  compromises, 
and  it  results  in  audio  quali- 
ty which  is  far  from  hi-fi. 
But  it  works. 

To  see  how  voice  can  be 
digitized,  look  at  Fig.  1(a). 
Here  we  see  a  typical  sound 
waveform  such  as  might  be 
picked  up  by  a  microphone. 
In  order  to  digitize  that 
waveform,  we  sample  it  at 
fixed,  periodic  intervals, 
and  digitize  the  voltage 
that  that  waveform  has  at 
those  instants  of  time. 

For  instance,  suppose  we 
measure  the  waveform 
voltage  at  the  points 
marked  with  a  dot,  convert 
the  value  of  that  voltage  to 
a  binary  number,  and  store 
it.  If  that  is  later  ''played" 
back,  we  get  the  waveform 
shown  in  Fig.  1(b).  The  result 
ts  a  square  waveform  which 
changes  to  a  new  value  at 
each  of  the  sampling 
points. 

Although  the  square 
wave  doesn't  look  anything 
like  the  original  audio  sig- 
nal, if  it  is  fed  through  a 
low-pass  filter  the  sharp 
corners  will  be  chopped  off 
and  the  signal  will  look  a  bit 
better. 

If,  on  the  other  hand,  we 
were  to  sample  the  audio 
signal  more  often  — not  on- 
ly at  the  dots  but  also  at  the 
intermediate  points  marked 
with  an  X  — and  digitize 
that,    the    resulting    wave- 


(c)    ORtlSthlAL    AUDIO 


(t)    DIGITIZED  AT   BUACK  DOTS   ONLY 


(>         ^ 


%■ 


(c)    DtaSTIZEO  AT    EACH   DOT  AND    X 


(4)    a  EG)  Tl  ZED  AT  Aft!  EXTREMELY   HIGH    RATE 

fig.  1.  Digitizing  audio  at  various  sampling  rates. 


form,  shown  in  Fig.  1(c), 
would  be  a  better  approxi- 
mation. 

Fig.  1[d)  shows  that  when 
we  digitize  very  often,  we 
get  the  best  waveform  yet. 
Although  this  waveform 
does  have  some  sharp  cor- 
ners, they  occur  at  a  very 
high  frequency  and  would 
be  removed  very  easily  with 
a  filter. 

How  often  must  we  digi- 
tize to  get  an  acceptable 
digitized  waveform?  There 
is  a  rule  called  the  ''sam- 
pling theorem''  which  says 
that  the  sampling  rate  must 
be  at  least  twice  the  fre- 
quency of  the  highest  fre- 
quency component  in  the 
audio  signal.  In  other 
words,  a  hi-fi  signal  with  a 
frequency  response  to 
20,000  Hz  would  have  to  be 
sampled  at  least  40,000 
times  per  second.  A  com- 
munications-quality voice 
signal  with  a  response  to 
4000  Hz  would  require  sam- 
pling at  least  8000  times  per 
second. 

We  can  get  an  idea  of 

this  from  Fig.  1(b).  Sampling 
at  the  black  dots  is  enough 
to  get  a  waveform  which 
follows  the  large  swings  of 
the  audio  waveform  which 
have  a  low  frequency  but 
cannot  capture  the  small 


squiggles  that  have  a  high- 
frequency  component  To 
get  those,  we  need  a  high 
sampling  rate. 

Fig.  2  shows  a  block  dia- 
gram of  the  circuitry  which 
would  be  needed  to  do  the 
digitizing.  Starting  with  the 
audio  signal,  the  signal  is 
amplified  and  sent  through 
a  low-pass  filter.  The  pur- 
pose of  the  filter  is  to 
remove  those  frequencies 
which  are  too  high  to  be 
digitized  (that  is,  more  than 
half  the  frequency  of  sam- 
pling). These  components 
have  to  be  removed  to 
avoid  further  distortion  dur- 
ing the  digitizing. 

The  filtered  signal  is  now 
sent  to  a  sample-and-hold 
circuit.  This  circuit  takes  a 
sample  of  the  waveform 
and  holds  it  in  a  capacitor 
while  the  analog-to-digital 
(A/D)  converter  converts 
the  resulting  voltage  to  a  bi- 
nary number.  This  is  neces- 
sary because  most  A/D  con- 
verters require  a  steady  in- 
put voltage  while  they  are 
converting;  if  the  voltage  is 
changing,  then  they  will 
probably  convert  the  volt- 
age to  the  wrong  value. 
Both  the  sample-and^hold 
circuit  as  well  as  the  A/D 
converter  are  driven   by  a 


164     73  Magazine  •  December  J  980 


CONTESnNG? 


THE  NEW  LOW  COST 
AEA  CONTEST 
KEYER  MODEL  CK-1 
WILL  MAKE  YOU 
MORE  COMPETITIVE 
THAN  EVER! 

^129.95 

SUGGESTED  AMATEUR  NET 


•  Automatic  Seriaf  Number  Generator  From  01  to  9999. 

•  500  Character  Soft  F^rtitioned  ™  Memory  That  Can  Be 
Divided  Into  as  Many  as  10  Messages. 

•  Exclusive  AEA  Memory  Edfting  Capability. 

•  Two  PresettaWe  Speeds  Witli  Fast  Recall  Plus  Stepped 
Variable  Speed  Selection. 

•  Iambic  Operation  From  1  to  99  wpm  and  Complete 
WBighting  Control. 

•  Extreme  R.F.  Immunity,  Will  Kay  Any  Modern  Trans- 
ceiver, Operates  from  1 2  ±  3  Volts  D.C. 

SEE  YOUR  FAVORITE  DEALER  OR  CONTACT 

Advanced  Electronic  Applications,  Inc.,  PO.  Box 
2160.  Lynnwood.  WA  98036.  Call  206/775-7373 


The  48  Hour 
Miracle. 


Brings  you  the 
BreaktnrougK! 


From  our  hands  to  yours 
in  record  time.  Like 
hvo  days  or  less.  Buf 
there's  more  to  the 
miracle  than 
Emergency  Service  and 
Guaranteed  Shipment. 

Sentiy  produces  the 
highest  quality^  cry^stal 
made.  Anywhere.  Each 
crj^stal  is  a  work  of  art, 
made  from  the  finest  raw 
materials,  utilizing 
state-of-the-art  technology 

Put  a  miracle  in  your 
hands.  Just  call  Sentry's 
toll  free  number, 
1_  800- 654-8850. 

ff  Sentry 


(^333 


UPTIME 


Check-TUne  your  ris  for  maxlmurn  power  with  a  B  &  W 
Dummyload-Wattineter 


■^J'^if^t^  "T*,"! 


'••■^.i^i^PC»/«F^'T1«HfMP*SlHJWSira»«PWW"BKni^a^^ 


Model  334A 

Freq.  Rense:  DC-300MH2 
VSWR:  Less  than  1.3:1 
Power  Ranse:  Up  to  1000  watts 


Model  374 

Freq.  Range;  DC-300MHz 
VSWR:  Less  than  1 .3:1 
Power  Range;  Up  to  1500 

watts 


•v^v 


ifiSKi^jl^-- 


B<W 


Model  333 

Medium  Power  Model 

Freq.  Range:  DC-300MHz 
VSWR:  Less  than  1 .3:1 
Power  Range:  Up  to  250  watts 

(-11 


K 


■V-.' 


■xf^/i-  «.■wb^JWs^e■.l6^:K<J' . 


•  ^i^^KXrO^  *m'l 


i^  Reader  Service-- see  page  226 


Barker  &  Williamson,  Inc. 

10  Canal  Street, 

Bristol.  Pa.  19007 

73  Magazine  •  December,  1980     16S 


*     FILTER 


SAWPL£ 
HOLD 


ANALOe   TO 

DIGfTAL 
CONVERTEf* 


D I S I TA  L 
OUTPUT 
OAtA 


CLOCK 


fa  J     SOU  SI  D-TO- DIGITAL   CONVER&fON 


DIGFTAL 
DATA 


DIGITAL   TO 

ANALOG 

CONVERTEfi 

FELTER 

* 

SPEAKER 


<(\ 


(H?     DIGITAL-TO-SOUND    CONVERSION 

fig,  2.  Circuitry  needed  to  digitize  audio. 


clock  oscillator  which  sets 
the  rate  at  which  the  input 
signal  is  sampied. 

The  output  of  the  A/D 
converter  is  now  a  binary 
number  which  can  be 
stored  in  memory  or  record- 
ed on  tape.  When  the  digi- 
tized data  is  played  back, 
as  shown  in  Fig.  2(bX  the 
binary  data  is  converted 
back  to  an  analog  signal 
with  a  digital-to-analog 
(D/A)  converter,  passed 
through  a  low-pass  filter  to 
remove  the  sharp  corners 
from  the  wave,  amplified, 
and  fed  to  a  speaker. 

Now  that  we  know  how 
often  a  sample  should  be 
taken  of  the  input  wave,  we 
have  another  question: 
How  accurately  must  it  be 
digitized  in  the  A/D  con- 
verter? This  is  related  to  the 
number  of  bits  produced  by 
the  converter  for  each  sam- 
ple. 

A  binary  number  consist- 
ing of  just  one  bit  can  take 
on  only  one  of  two  values  — 
either  0  or  1,  A  binary  num- 
ber consisting  of  two  bits 
can  have  values  of  00,  01, 
10,  or  11,  a  total  of  four  dif- 
ferent values.  In  general,  a 
number  which  consists  of  n 
bits  can  take  on  2^  different 
values.  For  instance,  ten 
bits  allow  1024  different 
numbers. 

Suppose  the  converter 
produces  a  binary  number 


consisting  of  just  one  bit, 
That  one  bit  is  not  enough 
to  indicate  the  precise  volt- 
age of  the  input.  With  one 
bit,  we  can  tell  only  wheth- 
er the  input  was  positive  or 
negative.  This  obviously 
will  lead  to  a  very  distorted 
wave,  since  we  cannot  hope 
to  keep  all  the  little  squig- 
gles  in  the  audio  signal. 

On  the  other  hand,  a  ten- 
bit  number  can  represent 
1024  different  numbers. 
Thus,  we  could  measure 
and  encode  512  different 
positive  voltage  levels  and 
512  different  negative  volt- 
age levels.  Thus,  the  more 
precise  we  want  our  mea- 
surements of  the  sample 
voltages  to  be,  the  more 
bits  we  need  for  etch  mea- 
surement. 

I  n  a  hi-fi  system,  we  often 
try  to  get  a  signal-to-noise 
ratio  (S/N]  of  60  dB  or  more. 
60  dB  is  a  voltage  ratio  of 
1000  to  1,  so  that  we  must 
be  able  to  reproduce  two 
signals  even  if  one  is  1000 
times  larger  than  the  other. 
This  requires  being  able  to 
measure  at  least  1000  dif- 
ferent positive  voltage 
levels  and  1000  different 
negative  voltage  levels,  for 
a  total  of  2000  different 
voltage  levels.  Since  2  — 
2048,  we  need  at  least  11 
bits  for  this.  By  the  time  you 
add  a  few  more  bits  to  al- 
low these  signals  to  be  re- 
produced with  low  distor- 


tion and  to  give  a  little 
''headroom"  so  that  an  oc- 
casional burst  of  extra  vol- 
ume can  get  through,  you 
are  close  to  14  bits  per  sam- 
ple. 

The  digital  systems  being 
proposed  in  the  hi-fi  indus- 
try use  between  14  and  18 
bits  per  sample;  14  bits  are 
used  In  consumer  products 
and  up  to  13  bits  are  used  in 
the  studio-quality  recorders 
which  produce  the  master 
tapes. 

How  many  bits  per  sec- 
ond (bps)  does  this  add  up 
to?  For  pure  hi-fi,  we  need 
at  least  40,000  samples  per 
second,  each  with  at  least 
14  bits,  for  a  minimum  of 
560,000  bps  (and  up  to  2 
MHz  in  studio-quality  sys- 
tems). At  a  rate  of  560,000 
bps,  a  16,384-bit  EPROM 
would  provide  hi-fi  for 
about  0.03  second.  Not 
enough  for  a  grunt,  let 
alone  a  ham  call. 

So  we  must  limit  the 
number  of  bits  per  second. 
This  is  done  by  drastically 
reducing  the  sampling  rate 
and  also  reducing  the  num- 
ber of  bits  from  the  A/D 
converter. 

To  squeeze  a  two-second 
call  into  this  ROM,  we  can 
store  8192  bps.  At  a  sam- 
pling rate  of  8000  Hz  or  so 
(to  cover  the  communica- 
tions audio  range  to  4000 
Hz),  that  gives  us  about  one 
bit  per  sample.  This  means 
that  we  don't  need  a  com- 
pfex  sampie-and-hold  cir- 
cuit, an  A/D  converter,  or 
even  a  D/A  converter.  All 
we  need  is  some  circuit 
which  can  tell  whether  the 
input  audio  is  positive  or 
negative  at  the  sampling  in- 
tervals, and  which  produces 
a  one-bit  output— 1  if  posi- 
tive, 0  if  negative.  That 
turns  out  to  be  very  simple 
to  do. 

The  disadvantage  is  that 
our  voice  recording  will  be 
very  distorted.  But  by 
heaviiy  filtering  the  output 
with  a  low-pass  filter,  we 
can  remove  some  of  that 
distortion  and  make  the  re- 


sult quite  understandable. 

The  Talking  Identifier 

Let's  leave  for  a  moment 
the  question  of  how  you 
''record"  the  voice  and 
store  it  in  the  ROM,  and 
look  at  the  circuit  of  the 
talking  IDer  itself,  Fig.  3. 

The  voice  pattern  is 
stored  in  a  2716  EPROM, 
This  is  a  memory  !C  current- 
ly selling  for  about  $10- 
$1 5.  It  is  organized  as  2K  X 
8,  meaning  that  it  has  2K 
storage  locations  (which  is 
2048),  each  holding  an  8-bit 
number. 

bach  of  those  2K  loca- 
tions has  an  address,  a 
binary  number  which 
ranges  from  00000000000 
to  11111111111.  This  11-bit 
address  is  fed  to  the 
EPROM  via  the  A10 
through  AO  address  pins 
shown  at  the  bottom  of  the 
iC.  Each  time  we  give  the 
EPROM  an  address,  it  out- 
puts the  contents  of  the  ad- 
dressed location  on  the 
eight  data  Jines,  D7  through 
DO,  shown  on  the  right  side 
of  the  EPROM. 

The  eight  bits  in  the  loca- 
tion come  out  in  parallel, 
meaning  alt  at  the  same 
time.  But  we  want  the  bits 
one  at  a  time,  roughly 
1/8000  of  a  second  apart, 
since  each  bit  represents 
one  sample  of  the  recorded 
voice  pattern,  (Over  a  space 
of  two  seconds  there  is  a 
total  of  16,384  samples  or 
bits,  which  are  stored  in 
consecutive  locations  on 
the  EPROM,  The  first  eight 
bits  are  in  memory  loca- 
tion 00000000000,  the  next 
eight  bits  are  in  location 
00000000001,  and  so  on,  up 
to  the  last  eight  bits, 
which  are  in  location 
11111111111,) 

The  job  of  splitting  up 
the  eight  bits  in  one  loca- 
tion into  individual  bits  is 
handled  by  the  74LS151 
multiplexer.  This  IC  be- 
haves like  an  SP8T  switch 
which  is  continuously  rotat- 
ing, scanning  the  eight  bits 
coming  in  from  the  EPROM 


166     73  Magazine  *  December,  1980 


+  3V 


24 


21 


10 


m 


■ci 


'w 


£7r6  ZH   K  a   EPROM 


DE 


*c? 


to 


A 


1 


A 
7 


A 


A       A 
*       4 


A      A 

S       2 


OT 

D» 
04 
OS 
Df 
Dl 


♦9V 

4| 

02 
D3 
04 
09 

3 

f 

.*          II 

T4LSiai 

4 

la 

MULTI- 

M 

14 

PLE3££R 

'lb 

13 

» 

12 

CCA 

T 


19     f£     Z3    \ 


IS 


14 


M    13    i£    II    to    9     e     T     A     &     4 


^020   14- BUT  C^HINr^R 


HF5ET 


n 


IT  A 


10 


B,  1&0K 

MA 


^ 


I? 


fl 
{^ 


T4LS91 

4 -BET  COUNTER 


U 


a 


r4LSl32 


much  like  the  distributor  in 
a  V8  car  engine.  It  changes 
the  parallel  data  coming  in- 
to  the  multiplexer  into  seri- 
al data.  The  result,  on  pin  5 
of  the  multiplexer,  is  a 
square  wave  which  carries 
the  frequency  components 
of  the  voice  but,  of  course, 
doesn't  have  any  amplitude 
information  because  ampli- 
tude was  never  digitized. 
This  signal  is  fed  into  an  ac- 
tive low-pass  filter  which 
uses  an  LM3900  Norton  op 
amp,  and  which  cuts  off  at 
just  under  4000  Hz.  This 
provides  the  audio  output. 

The  rest  of  the  circuit 
simply  provides  different 
addresses  to  the  EPROM  to 
scan  through  its  memory 
and  also  drives  the  multi- 
plexer. 

This  part  of  the  circuit 
starts  with  one  section  of  a 
74LS132  quad,  two-input 
NAND,  Schmitt-trigger  IC 
which,  along  with  a 
220-Ohm  resistor  and  0  4-uF 
capacitor,  forms  an  oscilla- 
tor   which    oscillates    at 


f/g.  3.  Talking  identifier  diagram. 

about  8  kHz.  The  output  of 
this  oscillator  is  sent  to  pin 
no  of  a  4020  CMOS  counter 
The  4020  is  a  14-stage  rip- 
ple counter  which  contain^ 
fourteen  flip-flops.  Since 
2^"^  =  16,384,  this  counter 
can  count  off  16,384  clock 
pulses.  Since  the  clock  fre- 
quency is  about  8  kHz,  if  we 
start  this  counter  at  a  count 
of  0,  it  will  take  approx- 
imately two  seconds  to 
count  up  to  its  maximum 
count.  As  it  does  so,  it's 
counting  off  the  16,384 
data  bits  which  are  being 
converted  into  an  audio 
signal. 

We  really  need  14  out- 
puts from  that  counter  to 
drive  the  EPROM  address 
lines  and  the  multiplexer. 
Unfortunately,  to  save  on 
pfns  the  4020  provides  only 
the  11  outputs  from  the  4th 
flil^flop  (Q4)  through  the 
14th  flip-flop  {Q1 4);  the  out- 
puts of  the  first  three  flip- 
flops  are  not  accessible.  So, 
we  have  a  second  counter, 
which  is  a  74LS93  binary 
counter  The  oscillator  sig- 


nal which  goes  to  the  4020 
goes  also  to  the  B  input,  pin 
1,  of  the  74LS93.  Three  of 
the  ffip-flops  in  this  IC 
(called  B,  C,  and  D)  count  in 
parallel  with  the  first  three 
flip-flops  of  the  4020,  and 
give  us  the  missing  signals. 

These  three  signals,  on 
pins  11,  B,  and  9  of  the 
74LS93,  change  very  rapidly 
and  continuously  drive  the 
multiplexer  which,  there- 
fore, scans  the  output  of 
the  EPROM  at  a  high  speed 
[one  bit  every  1/8000  sec- 
ond). 

The  eleven  bits  from  the 
4020  have  a  tower  frequen- 
cy and,  therefore,  drive  the 
address  lines  of  the  E  PROM 
at  a  slower  rate  (one  ad- 
dress every  1/1000  second). 
Thus,  the  EPROM  feeds  out 
a  new  group  of  eight  bits 
every  1 /1 000  second  Since 
there  are  2K  such  groups, 
this  again  takes  about  two 
seconds. 

When  the  two  seconds 
are  up,  the  4020  and  74LS93 
counters  reach  their  max- 


ff7 


AUDIO  OUT 


imum  count  and  reset 
themselves  back  to  zero  At 
the  fnstant  that  this  hap- 
pens, the  Q1 4  output  of  the 
4020  switches  from  a  high 
level  [near  5  volts)  to  a  low 
level  (near  0  volts).  This  sig- 
nal goes  to  an  unused  sec- 
tion of  the  74LS93  and  turns 
on  a  fourth  flip-flop  in  that 
counter;  as  a  result  its  QA 
output  goes  high.  This  sig- 
nal is  inverted  into  a  low  by 
another  section  of  the 
74LS132  and  is  fed  back  to 
stop  the  clock  oscillator,  As 
soon  as  the  2-second  voice 
ID  is  done,  therefore,  the 
clock  stops,  all  the  counters 
(except  the  A  flip-flop  in  the 
74LS93)  freeze  at  zero,  and 
the  IDer  stops 

The  IDer  is  restarted  by 
resetting  all  counters  to 
zero  with  a  positive  pulse 
coming  out  of  pin  3  of  still 
another  section  of  the 
Schmttt  trigger  NAND.  This 
start  signal  could  be  gener- 
ated externally,  but  for  use 
with  a  2-meter  FM  rig  on 
146.52  we  have  a  555  timer 
which  automatically  gener- 
ates a  very  short  reset  pulse 
every  30  seconds  or  so.  This 
pulse  resets  the  A  flip-flop 
in  the  74LS93,  which  re- 
leases the  clock  and  starts 
the  ID  process  all  over 
again. 

Connected  to  the  clock 
control  line  is  an  NPN  traOr- 
sistor  When  the  clock  is 
running  (that  is,  when  the 
IDer  is  identifying),  that 
transistor  is  turned  on; 
when  the  IDer  is  off,  so  is 
the  transistor.  By  connect- 
ing the  collector  to  the 
push-to-talk  (PTT)  line  of 
the  rig,  the  IDer  automati- 
cally keys  the  transmitter 
while  it  is  identifying.  This 
circuit  is  suitable  only  for 


73  Magaiifte  •  December,  1960     167 


Fig.  4.  PC  board,  copper  side. 


40  2  0 


T^ 

N 

C 

&i 

{ft 


■WV- 


o 
o 


> 

a 
o 
o 


o 


Fig.  5.  Parts  layout 


driving  the  PTT  line  in 
small,  transistorized  trans- 
ceivers. Those  rigs  which  re- 
quire large  currents  to  drive 
a  PTT  relay  may  require  an 
additional  buffer  transistor. 

Although  there  are  no  po- 
tentiometers in  the  circuit, 
there  are  several  compo- 
nents which  may  require 
adjustment.  The  100k  resis- 
tor in  the  active  filter  is 
chosen  to  provide  a  fairly 
small  output  audio  level;  ff 
more  audio  signal  is  need- 
ed, it  can  be  reduced  to  as 
low  as  5k.  Incidentally,  do 
not  use  disc  capacitors  in 
the  active  filter  circuit.  Use 
good  quality  polystyrene  or 
dipped  mica  caps. 

The  oscillation  frequen- 
cy of  both  the  74LS132  os- 
cillator and  the  555  timer 
depends  on  the  tolerance  of 
the  resistors  and  capacitors 
used.  Since  capacitors,  es- 
pecially, tend  to  have  very 
wide  variations,  some  trim- 
ming may  be  needed  to  get 
the  right  results.  To  vary  the 
spacing  between  IDs,  you 
may  want  to  increase  or  de- 
crease the  capacitor  value 
in  the  555  timer  circuit. 

If  the  74LS132  oscillator 
runs  too  fast  or  too  slow, 
the  voice  pattern  in  the 
EPROM  will  be  scanned  too 
fast  or  too  slowly,  with  the 
same  result  as  when  a  rec- 
ord is  played  too  fast  or  too 


slow.  You  may  like  the 
Donald  Duck  quality  this 
gives,  but  for  best  results 
you  should  trim  the  RC  val- 
ues in  this  oscillator  for  the 
most  natural  speech  sound. 

The  circuit  layout  is  not 
critical,  and  almost  any 
construction  method  will 
work,  including  wire-wrap 
and  temporary  prototype 
socket  hookup.  If  desired, 
you  can  use  the  printed  cir- 
cuit  board  shown  in  Fig.  4. 
Fig.  5  shows  the  parts  lay- 
out for  the  PC  board. 

The  identifier  needs  ap- 
proximately 100  mA  of  +5 
volt  power.  This  is  provided 
easily  by  a  three-terminal 
regulator.  If  you  use  the 
IDer  in  your  mobile,  simply 
include  the  regulator  cir- 
cuit of  Fig.  b.  Assuming  a 
load  current  of  100  mA  and 
a  worst-case  auto  battery 
voltage  of  16  volts,  the  reg- 
ulator must  drop  11  volts 
for  a  power  dissipation  of 
1,1  Watts.  With  a  good  heat 
sink,  all  this  can  be  dropped 
in  the  three-terminal  regula- 
tor itself;  by  adding  a 
39-Ohm,  2-Watt  resistor  as 
shown  in  the  circuit,  how- 
ever, we  drop  3.9  volts 
across  the  resistor.  This  re- 
moves almost  .4  Watts  of 
heat  from  the  regulator  and 
dissipates  it  in  the  resistor 
instead. 

For  applications  that  re- 
quire even  lower  power 
(such  as  for  battery-pow- 
ered applications),  total  cir- 
cuit power  can  be  reduced 
even  more  by  lifting  the 
chip  enable  pin  (pin  18)  of 
the  2716  from  ground  and 
connecting  it  instead  to  pin 
12  of  the  74LS93.  This  dis- 
ables the  2716  when  the  cir- 
cuit is  not  identifying.  The 
circuit  still  draws  around 
100  mA  when  identification 
is  in  progress,  but  cuts  it 
down  to  less  than  half  dur- 
ing other  times. 

'^Recording"  the  EPROM 

To  digitize  the  audio  sig- 
nal, we  need  a  filter  to 
remove  high-frequency 
components  above  4000  Hz 
and  a  comparator  circuit  to 


168     73  Magazine  *  December,  1980 


Adirondack  Rodio... 

Your  Rockweif'Coiims  deafer  for  the  northeast  and 
Upstate  New  York-has  the  fabutous  KWM-Sm  on  dis- 
play for  your  inspection. 

For  the  amateur  who  is  onfy  satisfied  with  the  finest, 
Adirondaak  Radio  Supply  wiHbe  happy  to  give  you  quo^ 
tat  tons  for  earty  delivery  for  a  truiy  professional  ama- 
teur station. 

MiroiMlack  Radio  Supptyjnc. 

185  WEST  MAIN  STREET 
AMSTERDAM,  NEW  YORK  12010 
TELEPHONE  (518)842'83S0     ^  i 


Unear 


2  t 


□  400  w\^'^ 


PLA 


NBoqK 


10nO  WATT 
13  Different  Mode ls,9B  pgs 

I     A.P.Systems  -r^  S11. 

I     Box  263  sm.  ^^^ 

IwVewport,  Rl  02840  {401}  846-5627        ^362 


BETTER  aUAUTV 
TOUCH-TONE^  OECODIWG 

With  Ihts  Touch-Tone^  Decoder  in 
your  rsdio  network,  you  can  turn  on 
transmitters,  control  attennae 
direction,  and  signal  over  pubHc 
and  private  telephone  networks. 

T)i«  TeHorw  M^917  acce|>t5  push- 
button OTMF  signals  from  a  radio, 
te^phone.  or  prerecordod  tspe- 

Pin  selectabte,  logic  tevel,  bmary 
Output  car\  drive  a  SchoitKey  TTL 
gate,  a  low  poivef  transistor,  a 
CMOS  Of  MOS  device. 

It's  compact,  complete,  field 
tasted^  aivd  pioven. 


^=«KtQ(^, 


The  hCAN  Company 

P.O.  Box  1417 

OrariQe  Park,  Florida  32073 


MAGNETIC  CALL  SIGN 

Great  for  mobile  or  shack 


Your  call  sign  in  biitliant  wtilte  letters  on  Dlack  background  indoor^out- 
door  weather  Tesistarjt  •  sticks  to  any  ferrous  metal  appfoximately  j 
2''>c9"  «  instam  on/of (  •  won't  mar  finish J^S^  ^  *  *>2 


Magnetic  Call  Sign 
$3.95  PPD  USA        P.O.  Box  t6l38S 

Miami,  FL  33116 


^3SB 


H^: 


rmG** 


a-io 


7m 


tm 


Kl^ 


TOD 


^ 


30 


^ 


SJOff' 


jrrt 


20O*- 


m 


M 


ajQ»^ 


^    30Q 


Jt*^' 


BECKMAN 

3y2 -DIGIT  MULTIMETER 

MODEL  TECH  310 

COMPLETE  MULTIMETER  CAPABILITY: 

DC  VOLTS:     100  uV  TO  1S00  V 

AC  VOLTS:     100  uV  TO  1000  V  rms 

RESISTANCE:     0.1  OHMS  TO  20  MEGOHMS 

DC  CURRENT:     100  nA  TO  10  A 

AC  CURRENT:     tOO  nA  TO  10  A 

DIODE/SEMICONDUCTOR  TEST  FUNCTION, 

CONTINUITY  FUNCTION  -  INSTA-OHMS  [TM]. 

COMPLETE  OVERVOLTAGE  PROTECTION. 

LOW-POWER  OHMS  IN  ALL  RESISTANCE 
RANGES. 

FULLY  EQUIPPED  WJTH  THE  FOLLOWING: 
9-VOLT  BATTERY,  A  SPARE  FUSE,  SAFETY- 
DESIGNED  TEST  LEAD  SET,  OPERATOR'S 
MANUAL  AND  BECKMAN 'S  FULL  ONE-YEAR 
WARRANTY. 

OPTIONAL  ACCESSORIES  AND  PRICES: 

TECH  310  DIGITAL  MULTIMETER $140.00 


4       t       ♦       ♦ 


*       «      •      * 


i     *     p     i 


DC-202  DELUXE  CASE 
VC-201  VINYL  CASE 

DL-241  DELUXE  TEST  LEAD  KIT 

TL-242  TEST  LEAD  SET  [  AS  SUPPLIED]  . 

LaRUE  ELECTRONICS 

1112  CRANDVJEW  STREET 

SCRAN  TON,  PENNSYLVANIA  18509 

PHONE  [7171343-2124 


*24.00 
.10.00 
.10.00 
.  .6.00 
.35.00 


w^ne^iSef  Service— see  page  22G 


73  Magazine  •  December,  1980     168 


sense  the  polarity  of  the  in- 
put audio.  This  circuit  uses 
another  LM3900  quad  Nor- 
ton op  amp  and  is  shown  in 
Fig.  7. 

One  op-amp  in  the 
LM3900  is  used  as  an  active 
tow-pass  filter  with  a  cutoff 
frequency  of  just  under 
4000  Hz.  This  amplifier/fil- 
ter has  a  small  amount  of 
gain  but  not  enough  to  ac- 
c:ept  the  weak  signal  from  a 
microphone.  It  is  designed 
for  use  with  an  external 
mike  preamp  or  with  the 
higher-level  output  of  a 
tape  recorder.  1  generally 
record  the  desired  message 
on  tape  first  and  then  feed 
the  speaker  output  of  the 
recorder  to  the  audio  input 
of  this  circuit. 

A  battery-operated  re- 
corder is  best  in  this  case, 
since  with  a  high  gain  it  is 
possible  for  hum  to  be  digi- 
tized between  words.  Hum 
gets  swamped  out  during 
speech,  but  when  there  is 
silence,  the  circuit  works 
much  like  a  volume  com- 
pressor by  boosting  low- 
level  sounds.  Thus,  a  good 
S/N  ratio  is  essential.  The 
10k  volume  control  on  the 
input  helps  to  cut  down  ex- 
cessive signal;  its  correct 
adjustment  is  important. 

The  output  of  the  filter  is 
sent  to  another  op-amp  sec- 
tion of  the  LM3900,  which  is 
used  as  a  slicer  or  compara- 
tor. The  signal  coming  from 
the  filter  is  sent  to  one  input 
of  this  op  amp  while  a  refer- 
ence current  from  the  10k 
zero-set  pot  is  fed  to  the 
other.  As  the  filtered  audio 
output  goes  above  or  below 
the  reference  signal,  the 
digital  output  from  pin  9 
switches  between  0  and  H-5 

volts. 

The  10k  zerO'Set  pot 
should  be  adjusted  so  that 
with  the  audio  input  short- 
ed to  ground,  the  output  is 
just  on  the  verge  of  switch- 
ing between  0  and  +5 
volts.  With  proper  adjust- 
ment, positive  audio  peaks 
will  clip  the  digital  output 
one  way  while  negative 
peaks  flip  it  the  other  way. 


For  testing  purposes,  an 
audio  amplifier/speaker 
combination  can  be  con- 
nected to  the  digital  output 
to  monitor  the  signal  after  it 
has  been  digitized;  1  use  an 
inexpensive  Radio  Shack 
signal  tracer  for  this  pur- 
pose„  The  digitized  signal  is 
supposed  to  be  filtered  be- 
fore being  heard,  so  this  sig- 
nal will  sound  excessively 
harsh,  but  it  is  good  enough 
to  give  you  an  idea  of 
whether  the  circuit  is  work- 
ing. 

Once  we  have  the  one-bit 
digital  output,  we  must 
sample  it  at  intervals  of 
about  1/8000  second,  con- 
vert the  samples  into  8-bit 
bytes,  and  store  them.  Be- 
fore burning  them  into  the 
EPROM,  however,  it  is  very 
convenient  to  be  able  to 
''play"  them  back  to  make 
sure  that  the  volume  con- 
trols have  been  set  right 
and  that  we  have  the  right 
voice  segment.  It  also 
would  be  very  convenient  if 
in  some  way  we  could  edit 
the  digital  code  to  elimi- 
nate any  noise  just  before 
and  after  the  call.  In  other 
words,  it  would  be  very  con- 
venient if  we  could  store 
the  message  in  RAM  and 
read  or  modify  it  before  it  is 
permanently  stored  in 
EPROM. 

Building  S  special  piece 
of  hardware  for  just  this 
purpose  is  difficult  and  ex- 
pensive. Fortunately,  most 
home  or  personal  compu- 
ters have  an  input  and  out- 
put port  which  could  be 
used  to  input  or  output  this 
one-bit  digital  signal  and 
also  have  RAM  which  could 
be  used  to  store  the  code 
temporarily.  This  makes  the 
job  almost  trivial. 

To  do  this,  you  need  a 
program  which  will  input 
data,  group  bits  together  in 
sets  of  8,  and  store  them.  In 
most  cases,  this  program 
has  to  be  written  in  ma- 
chine or  assembly  language 
since  most  BASIC  systems 
are  not  fast  enough  to  take 
8000  samples  per  second 
and  process  them. 


IN   FROM  AUTO 


t 


LM309K 
OR  7805 


^5V 


^0-1  (KEAT  SIMKl 


X 


iff 


1 


O.l 


Fig.  6.  yo[tdi%'e  regulator  for  mobile  use. 


TO   *3V 


INPUT 


m 


ImF 


VOLUME 


4TK                                   ^ 
-W\* It— Vw — ♦ ^ 


DIGITAL 
*■  OUTPyj 


174   LM3900 


TO   *5V 


Fig.  7,  Audio-to-digital  conversion  circuit 


Obviously,  the  program 
will  depend  on  the  particu- 
lar computer  used,  but  as  a 
starter,  Tm  including  here 
three  programs  written  for 
an  SWTP  6800  system 
which  are  very  useful. 

Parallel  input/output  on 
6800  systems  is  usually  han- 
dled by  an  IC  called  a  PIA 
or  Peripheral  Interface 
Adapter.  Although  this  IC 
has  twenty  input/output 
pins,  only  two  are  used  in 
this  application  — bit  0  of 
port  A  gets  the  input  from 
the  circuit  of  Fig.  7,  while 
bit  1  of  the  same  port  feeds 
an  audio  amplifier/speaker 
combination  which  is  used 
to  listen  to  the  recorded 
sound. 


Program  1  is  an  echo  pro- 
gram which  is  used  only  for 
testing.  It  inputs  via  bit  0, 
outputs  the  bit  right  back  to 
bit  1  of  the  input/output 
port,  and  then  waits  for  a 
short  while  to  simulate  the 
delay  between  samples. 
When  everything  is  running 
correctly,  the  audio  coming 
out  of  the  computer  will 
sound  very  similar  to  the 
audio  you  could  hear  di- 
rectly at  the  output  of  the 
circuit  of  Fig.  7.  (It,  too,  will 
sound  harsh  because  of  the 
lack  of  filtering.) 

The  program  starts  by  ini- 
tializing the  PIA  to  set  up 
the  correct  bits  for  input 
and  output  The  main  part 
of  the  program  (starting  at 


*  * 

*  THIS  PROGRAM  IMPUTS  DftlA  FFEOM  PORT  ft  BIT  0  » 

*  OF  A  PIA  1«  PORT  ?,  AMD  ECHOES  IT  TO  BIT  1  ■¥ 

*  •* 


(0100) 

0100  7F  aom 

0103  B6   0? 

0(03  B?  eoic 

&10B  S6  04 
010A  i?   801D 

(»ic[<  u  doic 

4110  4B 

01M  91^  02 
01 1i  20  F5 


PIAAAT  EQU 
PIACTL  im 


tSOIC     P(JRT  A  DATA/HIRECTIDN  REG 
PlftBAT*!   PORT  A   CONTROL  REGISTER 


ORG   »0100 
STftRT   CLR   PIACTL 

LDA  ft  m 

S1A  A  PIADAr 

LDA  A  ^i^ 
5TA  A  PIACTL 
LOOP   LDft  A   flflPAT 
ASL  A 

STA  is   PIADAT 
»SR   UAIT 
BRA   LUOP 


RESET  PIfl 

SET  BIT  0=INPIJT.  BIT  1 -OUTPUT 

ItESET  BftCK  TD  DATA 

LOAD  DfttA  fROn  PORT  A  BIT  0 
SHIFT  LEFT  INTO  BIT  \ 
OUTPUT  TQ  PORT  A  BIT  1 

GO  BACK  AHS\   REPEAT 


*  FOLLOUIHG  UAIT  R^UTIME  INTRODUCES  A  DELAY 
«  UHICH  PERHITS  SANPLIHG  RATE  TO  BE  EKAN6ED 


IKniALIIE  INttEX  REGISTER 
DECREt1E«T  INDEJi 
REPEAT  IF  mi   YET  ZERO 

OTHEftUISE  RETURU 


0119  CE   0010 

UAIT 

LDX 

HOOiO 

oni  Q? 

MAITl 

DE)( 

OtU   26   FB 

BNE 

UAITt 

OllE   39 

RTS 

Program  1.  Echo  test 


170     73  Magazine  •  December,  1980 


RTTY  READER— NEW  LOW  PRICES! 


I-      i.      I. 


H  \.l 


._  *«  or  r  V  *« 


RTTV 


Decodes  RTTY  signals  directly  frorri  yqur  re- 
ceiver's foLidspeaker,  *  Icieal  for  SWLs,  novices  & 
seasoned  amateurs.  *  Completely  solid  state  and 
self-contained.  Compact  si^e  fits  almost  anywhere. 
No  CRT  Of  derrrodulator  required  .  .  .  Mothing 
extra  to  buy?  *  Built-in  active  mark  &  space 
filters  with  tuning  LEDs  for  170,  425  &  850  Hz 
FSK,  *  Copies  60.  67,  75,  &  100  WPM  Baiidot  & 
100  WPM  ASCII.  #  NOW  you  can  tune  in  RTTY 
signals  from  amateurs,  news  sources  St  weather 
bulletins.  The  RTTY  READER  con^/crts  RTTY 
Signals  into  alphanumeric  symbols  on  an  eight-character  moving  LED  readout.  Write 
for  details  or  order  factory  direct* 

RTTY   RHADE:R    kit,   model    RRK  .,.,..... $169.95 

8TTY  READER  Wired  and  tested,  mode!   RRF $249.95 

Send   check   or   money   order.  Use  your  VISA  or  MasterCard.  Add  $5.00  shipping  and 
handling  for  continental  U.S.  Wisconsin   residents  add  4%  Wisconsin  State  Sales  Tax. 


'^i^a<t^^f 


iMMMiMumtmm 


^ifUcnecn^Xj^ 


Corporafion  Telephone:  (414)  241-8144 

Post  Office  Box  513G,  ThiensviHe,  Wisconsin  53092 


*^50 


IRON  POWDERand  FERRITE  PRODUCTS 


1^334 


Fast,  Reliable  Service  Since  1963 


Small  Orders  Welcome 


Free  'Tech- Data'  Flyer 


Toroidal  Cores,  Shielding  Beads,  Shielded  Coil  Forms 
Ferrite  Rods,  Pot  Cores,  Baluns,  Etc, 

12033  OTSEGO  STREET,  NORTH  HOLLYWOOD,  CALlFORNtA  91607 


I 


^tffisrjK^  >-^ 


i 


*.  ^1 


ife^ 


i 


-...<3i2i: 


PRETUNED  -  COMPLETELY  ASSEMBLED  - 
ONLY  ONE  NEAT  SMALL  ANTENNA  FOR 
UP  TO  7  BANDSl  EXCELLENT  FOR  CON- 
GESTED HOUSING  AREAS  -  APARTMENTS 
LIGHT  *  STRONG  -  ALfVIOST    INVISIBLE! 


FOR  ALL  MAKES  i  MODELS  OF  AMATEUR 
TRANSCEIVERS        -  TRANSMITTERS      - 

GUARANTEED  FOR  2OO0  WATTS  SSB 
TOGO  WATTS  CW.  INPUT  FOR  NOVICE  AND 
ALL  CLASS  AMATEURS! 


COMPLETE  AS  SHOWN  with  90  It,  RGSaU-52  ohm  teedJIne^  and  PL3S9  connector,  insulators.  30  f t. 
30O  \h.  test  dacron  tnd  supports,     center  cQnnector  with    buHt  In     lightning    arrester  and  static  dlstharge  - 
moLcted,  sealed,  weatherproof,  resonant  traps  1"X6"-s?ou  just  switch  to  band   desired  for  eifcellent  worldwide 
operation  -  transmitting  and  reclewlngl  Low  SWR  over  all  bands   -Tuners  usually  NOT  NEEDED!  Can  be  used  as 
Inverted  V's  -  slopers  -  in  attics,  onbuiSdinfl  tops  or  narrow  lots    The  ONLY    ANTENNA  YOU  WILL  EVER  NEED 
FOR  ALL  DESIRED  BANDS  -WITH  ANY    TRANSCEIVER  -  NEW  ^  EXCLUSIVEI  NO  BALUNS  NEEDED! 

aO-40-2O-t5-1O-6  rptter-  2  trap  —  104  f t,  with  90  ft.  RGSBU    -  conneetoj-  -Mode»  99©BUA  .  .  .  S69.9S 
40-2O-15-tO  meter —  2  trap  -—54  ft,  with  90  ft.  RGSSU    -  tOnnector    -    Model  lOOlBUA  ....  $6895 

20-15-10   meter  —    2  trap*—  26ft.  with  90  ft.  RG5SU    *  connector  *    Model  1007BUA  .  .....  $67.95 

SEND  FULL  PRICE  FOR  POSTPAJD  INSURED  DEL.  IN  USA.  (Canada  is  S5.00  e>tir^  for  pt^sta^e  -  clerical- 
eust&ms  «tc,)or  order  using  VISA  -  MASTER  CHARGE  -  CARD  -  AMER.  EXPRESS.  Give  number  and  ex, 
date.  Ph  1-308-235-5333  9AM  -  6PM  week  days.  We  ship  m  2-3  days.  ALL  PRICES  WILL  INCREASE  .  . 
SAVE  -  ORDER  NOW!  All  antennas  guaranteed  for  1  year.  lO  day  money  back  iriat  W  returned  in  new  condtt^n! 
Made  in  USA.  FREE  INFO.  AVAILABLE  ONLY  FROM 

WESTERN  ELECTRO NiCS  D«pl.  A7-12  ^^^        Kearney,  Nebraska.  66847 


I 


I 


i 


CENTRAL  NEW  YORK'S  MOST  COMPLETE  HAM  DEALER^ 

DRAKE 
ECOM  MMIMgqj!MW       TR7-t3R7 

lC-720 


YAESU 


ROBOT 


KENWOOD 
TS830S 


w* 


FT707 


Featuring  Kenwood,  Yaesu,  tcom,  Drake,  Ten-Tec,  Swan,  Dentron,  Alpha,  Robot, 
MFJ,  Tempo,  Astron,  KLM,  Hy  Gain,  Mosley,  Larsen,  Cushcraft,  Hustler,  Mini 
Products,  Bird,  Mirage,  Vibroplex,  Bencher,  Info-Tech,  Universal  Towers, 
Callbook,  ARRL,  Astatic.  Shure.  We  service  everything  we  self! 

Write  or  call  for  quote.  You  Won't  Be  Disappointed. 
We  are  just  a  few  minutes  oft  the  NYS  Thru  way  (1-90)  Exit  32 


mauei  i-.naqi: 


OUT  OF  STATE        ONE 
CALL  TOLL  FREE 

800-448-9338 


ONEIDA  COUNTY  AIRPORT  TERMINAL  BUILDING 


ORISKANY,  NEW  YORK  13424 
N.Y.  Res.  Call  (315)  337-0203 


Warren  •  K2 1 XN 
Bob  -  WA2MSH 


35 w  2  m  FM  amplifier  kit 
3  Watts  In— 35  Watts  Out 


^"> 


^ 


$69  i^ 

PPD 

ysA 


MODEL  335-K 


ma^\«'  *hBr^t 


Communication   Concepts  Inc. 

2646  NORTH  ARAGON  AVE 

DAYTON.  OHIO  45420  i^u^^ 

(513)296-1411 


i  PILOTS 'i 


.^^ 


I 


.  ?  ■ 


I 

I 
I 


I 


Build  your  own  aircraft  • 
trarjsceiver.  For  details  send  « 
for  FREE  CATALOG,  * 


Radio  Systeins 

Technology,  fnc, 

10985-T  GRASS  VALLEY  AVE- 
GRASS  VALLEY.  CA  95943 


UPGRADE 
SUCCESSFULLY! 


—  PASS  THE  FCC  EXAM— 


ANNOUNCING 

the  New  1981 

LICENSE  THEORY  REVIEWS 

FOR  THE 

TRS-80  16K  Computer 

12  Programs  Per  License  Class 
Each  Comprehensive  Package 
Totals  98,000  Bytes. 
General.  Advanced  or  Extra. 


$19.95 

each 


or 


$39.95 

for  all 


pH'SBS 


m80^'^ 


MICR0-80™  [NC 

5^2665  No.  Busby  Road 
Oak  Harbor,  WA  98277 


*^  Reader  Servtc&see  page  226 


73  Magaztrte  •  December,  1980    171 


r  * 

»  THIS  PRQGRftM  INPUTS  DATft  FROH  PORT  ft  BIT  0   i 

*  OF  A  PIfl  IN  PORT  7,    PfiCKS  6  BITS  PER  BYTE,   * 
«  ANB  STORES  THE  DATA  IN  HEHDRr  LI3CATIDNS  lOOC  « 

*  TO  7FFf .  * 

*  ir 


U01C} 

PIABAT 

EGU 

leOlE 

POftT  A  DATA/fllftECTlOM  RE6 

rsoiD) 

PlfiCTL 

EQU 

PlADftTH 

FOftT  A  CONTROL  REGISTER 

tOlOO) 

ORG 

to  100 

0100  7f 

eoiD 

START 

CLR 

PIftCTL 

RESET  Pi#i 

oioiS  e& 

02 

IDA 

ft 

it  2 

SET  BIT  0=^INPI;T,  bit  l^QUTPUT 

0105  &? 

fiOIC 

STA 

A 

PIABAT 

01 oe  Si 

04 

LDA 

ft 

4114 

RESET  BACK  TO  BATA 

OIOA  &7 

B01D 

5TA 

A 

FIACTL 

0100  CE 

!000 

LDJS 

ritiooo 

POlNT  TO  MEHORY  BUFFER  ADDRESS 

0110  Ci 

oe 

LOOPl 

IDA 

B 

ft*OB 

0112  F7 

0132 

STA 

& 

BITCrft 

COUNT  3  BITS  PER  BYTE 

&1t5  4F 

CLR 

A 

ERASE  A  ACCJrtULATQR 

01U  Fi 

aoic 

L0QP2 

LDA 

B 

PIADAT 

REAC  DATA  INTO  B  ftCCUrtULATOR 

OH?  C4 

01 

AND 

g 

«iai 

ftASK  OFF  EOERnHlNG  EXCEPT  SlT  0 

ens  4B 

ABL 

A 

SHIFT  A  ACCyft  LEFT 

one  IE) 

Al^^ 

ADiJ  WELJ  BIT  FRQH  B  TO  A 

01  ID  Ci 

10 

LEA 

B 

HIIO 

SET  LJP  COyhfTEft  FOR  SAHPLIHG  DELAY 

011F  5ft 

4AIT 

DEC 

e 

PECREHENT  B 

^iia  26 

FJ 

m 

UAH 

REPE^^T  IF  NOT  YET  ZERO 

0122  7ft 

0132 

DEC 

BITCTR 

DO  FOR  8  BITS 

0125  2i 

EF 

BNE 

LaOP2 

BET  H£XT  eiT 

012?  A7 

00 

STA 

A 

0,X 

STORE  BtTE  UHEN  COMPLETED 

012i?  08 

IWX 

INCREMENT  INDEX  REGISTER  POINTER 

012A  3C 

7fFF 

zn 

fl(7FfF 

CHECK  FOR  END  DF  MEHORT 

01  2D  24 

El 

BflE 

LOQPl 

REPEAT  IF  OK 

QT2F  7£ 

EODO 

JNP 

tEODO 

RETURN  m  nnmiQ^  miH  dohe 

0132 

HTCFR 

RH& 

1 

BIT  COUNTER  TO  COUNT  8  BITS 

Program  2.  Ir^put 


*  * 

*  THIS   PROfiRAN  C£TS  CATA  FROH  HEtlORY  * 

*  LOCATIONS    IOOO-7FfFr   UNPACKS  IT   If*TO  * 
t    rj+DlVIDUAL    BIT5»    AND  OOTPLTS    TO   PORT  A   * 

*  BIT   1    Of  A   PU   IK  POftT  7,  *■ 

*  * 


(eoici 
leoiB) 


PIADAT  EQU 

f^IACTL  EOJ 


02 

aoic 

04 

80  ID 
1000 

03 

01  B4 
00 


(OliO) 

0180  7f   S01D 

S& 

B7 

67 

CE 
C6 
F7 
A£ 
16 
49 
59 
59 
SV 
C4 
F7 
U 
5A 
2£ 
7A 
24 
08 
9C 
26 
7E 


START 


01^3 
01B5 
0183 
OISA 

01BD 
0190 
01?3 
0195 
019? 
019B 
019V 
019  A 
019& 
019C 
019E 
01A1 
01A3 
01  A4 
01  Ai 
01A? 
OlAB 
01AC 
OlAf 
01B1 


LOOPl 


LD0P2 


02 

eoic 

OG 

FD 

&IB4 

EC 

7FFF 

DF 

EODO 


UAIT 


DRQ 
CLR 
L[^ft 
STA 
LDA 
STA 
LftX 
LDA 
STA 
LDA 
TAB 
ASL 

mi 

ROL 
RDL 
AHI^ 
STA 
LDA 
DEC 
bNE 
DEC 
BNE 
INK 
CP)( 
BNE 
JMP 


130 1  C 

PIADATtI 

PIACTL 

H2 

PIADAT 

«f4 

PtACTL 

tttlOOO 

ttfoe 

BiTCTR 
0,X 


Iit02 
PIAMT 

ttioe 

WAIT 

tnCTR 
LD0P2 

ItlJFFF 

LOOPl 
*EOPO 


0184 


BITCTR  RHB   1 


POST  A  DATAADIR  REGISTER 
PORT  A  CONTROL  REGISTER 


RESET  PI  A 

SET  BIT  0-lHPUT,  BIT  l=OUTPyT 

RESET  BACK  TQ  DATA 

POINT  TO  hEHORY  BUFFER  ^^iSDRESS 

COUNT  8  BITS  PER  BYTE 

GET  NEXT  BYTE  FROM  ttEMDRV 

TRANSFER  IT  TO  B  REGISTER 

SHIFT  A  ACCUrt  LEFT  1  BIT 

ROTATE  B  LEFT  3  BITS  TQ  tlGUE  THE  CUftRENT 

BIT  FROM  BIT  ?    (LEFT-rtOSTJ  TNTD 

BIT  1  ^SECOND  FftOM  RIGHT } 

HASK  OFF  EVERYTHING  EXCEPT  BIT  I 

OUTPUT  TO  RIA 

SET  UP  COUNTER  FOR  SAMPLING  DELf^V 

DECf^EHENT  S 

REPEAT  IF  NOT  TET  liKQ 

m   FQR  a  SITS 

IF  BIT  COUNTER  NOT  ZERO 

INCREMENT  INDEX  UHE^  BYTE  IS  &DWt 

CHECK   FOR  £*fD  OF  ftEHORif 

REPEAT    IF   OK 

RETURN  TO  HOHITOR  UHEH  DONE 

BIT  CODNTEft.  TO  CQUNT  B  BlTr 


Program  3.  Output 


the  statement  labeled 
LOOP)  loads  a  bit  from  the 
PIA,  shifts  it  left  from  bit  0 
into  bit  1,  and  outputs  it. 
Then  it  branches  to  a  WAIT 
subroutine  for  a  short  de- 
lay, after  which  it  branches 
back  to  LOOP. 

For    experimental    pur- 
poses, it's  important  to  be 


able  to  calculate  how  many 
samples  are  taken  per  sec- 
ond. This  is  done  by  com- 
puting how  many  computer 
clock  cycles  are  required 
for  each  instruction  in  the 
loop.  In  Program  1,  the 
main  loop  takes  31  clock 
cycles  plus  8  cycles  for 
each    repetition    of    the 


WAIT1  loop.  With  the 
WAIT1  loop  initialized 
(with  the  LDX  instruction)  to 
run  16  times  (0010  hexadec- 
imal), the  total  time  be- 
tween samples  is  31  +  (16) 
X  [8)  =  159  clock  cycles. 

In  a  typical  SWTP  com- 
puter running  with  a 
900-kHz  clock,  each  clock 
cycle  takes  1.11  microsec- 
onds, so  that  the  total  delay 
between  samples  is  177  mi- 
croseconds; this  translates 
into  a  sampling  rate  of 
about  5600  samples  per  sec- 
ond, which  is  about  the 
minimum  that  can  be  used 
for  acceptable  results.  For 
8000  samples  per  second, 
the  LDX  instruction  should 
be  changed  to  run  the 
WAIT1  loop  10  times. 

Once  the  echo  test  pro- 
gram reveals  that  the  A/D 
conversion  and  the  compu- 
ter input/output  circuitry  is 
working  correctly,  Program 
2  can  be  used  to  input  data 
into  the  computer's  mem- 
ory, while  Program  3  is  used 
to  output  it  back  to  the 
speaker.  Both  of  these  pro- 
grams have  a  WAIT  loop 
which  provides  some  con- 
trol over  the  delay  between 
samples.  There  is  some  lee- 
way here  in  adjusting  this 
delay.  If  the  number  of 
samples  taken  per  second  is 
changed  above  or  beiow 
8000  (to  increase  playing 
time,  for  instance),  the 
clock  oscillator  frequency 
in  the  identifier  circuit  of 
Fig.  3  also  has  to  be 
changed  to  a  similar  value 
or  the  final  output  will  have 
a  pitch  which  is  too  high 
{like  Donald  Duck)  or  too 
low. 

Both  programs  are  lo- 
cated in  low  memory,  with 
the  input  program  starting 
at  location  0100  [hex)  and 
the  output  program  at  01 80. 
They  do  not  overlap  and, 
therefore,  can  be  in  mem- 
ory at  the  same  time,  Thus, 
we  can  input  audio,  store  it 
in  memory,  and  then  output 
it  right  back. 

The  programs  are  written 
for  a  32K  computer  and  use 
locations     1000     (hex) 


through  7FFF  to  store  the  re- 
sultant digital  data.  This  is  a 
total  of  28K  of  memory;  at 
the  rate  of  IK  per  second, 
this  can  store  a  total  of  28 
seconds  of  sound.  When 
Program  2  is  finished,  it  re- 
turns to  the  monitor.  Rather 
than  calculate  the  sampling 
rate  by  computing  the  num- 
ber of  cycles  per  loop,  etc., 
an  easier  way  to  adjust  the 
WAIT  loop  is  to  note  how 
long  the  overall  program 
runs.  If  it  runs  exactly  1  sec- 
ond per  K  of  memory  used, 
then  it  is  running  at  8192 
samples  per  second. 

By  changing  the  starting 
address  (1000  hex)  or  the 
ending  address  (7FFF)  in 
Program  3,  we  can  ''play" 
back  just  selected  portions 
of  the  input.  In  this  way,  we 
can  pick  one  of  several  ver- 
sions of  the  same  call, 
choosing  the  one  that 
sounds  best.  This  allows  us 
to  edit  the  data  before  it  is 
stored  into  EPROM.  Once 
you  find  the  portion  which 
sounds  best,  burn  that  por- 
tion into  the  EPROM  and 
keep  the  rest  of  the  EPROM 
data  empty  (an  erased  2716 
EPROM  has  a  hex  FF  in 
every  location).  This  will  as- 
sure that  no  noise  or  sounds 
are  in  the  EPROM  other 
than  the  actual  call. 

Conclusions 

While  this  talking  identi- 
fier won't  win  any  awards 
for  hi-fi  quality,  it  is  perfect- 
ly understandable  and  ful- 
fills its  purpose  well.  It  also 
gives  you  a  chance  to  ex- 
periment With  speech  re- 
production via  digital 
means.  In  addition,  it's  a  lot 
more  satisfying  to  build 
such  a  device  from  com- 
monly-available tCs  than  to 
go  out  and  buy  an  expen- 
sive synthesizer  chip  or  sys- 
tem. Why  don't  you  try  it? 

So,  if  you  ever  hear  some- 
thing grumble  "K20AW'' 
on  146.52  as  I  speed  by  your 
house  on  the  nearby  Inter- 
state, maybe  you'll  be  able 
to  turn  on  your  own  IDer 
and  have  it  come  back  to 
me.H 


172     73  Magazine  •  December,  1980 


23  0  0   MHZ 
DOWN  COHVERT£R 


MERRY 


CHRISTMAS 


FROM 


DEBDflAtt  ind      STEVE  .HbSkfL 

41NQMM   HI  nt  STOP  SlDN  ftOMAO. 
THIS  nMmlif  DQWNCONVErEH   KIT 
WORKS   lKtlMPftiJ!/ED  eOAffD  tVEN 
MAKES  HBET7EH  THftff  BErQIlL 
SI^  WNV  PAY  TWICf  AS    MUCH? 

Kit   Sijppjied  with  a  6  page 

broshure.  PC  board,  Diodes, 

Chip  Cap^,  Transistor^, and 

al(        parts   to  complete  a 

working   board.    $  53^V 

'  POWER 

SUPPLES  a*ii 

Money  Order,  or  Check 

mail  or  Phoi^e 

UNIVERSAL  COMMUNICATIONS 


f?0- BOX  &302;  AfiLINGION.  TEX.     76011 

817-265    039  1 


BRAKE 

BEND  &  FORM 
.060  ALUM.  & 

STL. 


EASY 
TO  USE 


BUILD  CUSTOM 
CABINETS  YOU'LL   BE 
°^j  PROUD  OF!  COMMERCIAL 
QUALITY  AT '/lo  THE  COST  I 


GUARANTEED! 

ORDER  NOW  from; 


P&h 


ASSOCIATES 

PO  BOX  757  *»n|w     c««m< 

30SD  NE  S5  TH  «VI    >^336     z"'''^*^^. 
SILVER  SPRINGS  ,  ft*,  JJ*M   "O  COOS.        | 


cont.  U.S. 
>nly.  sor 
no  cods. 


PRODUCTION  OVER-RUNS 
ASSORTED  . . .  NEW 

MINIATURE 
SWITCHES 

TOGGLES,  ROCKERS, 
SLIDES,  etc. 

From  Dne  of  America's 
Leading  Manufacturers 

Origmai  Cost  to  $15  E^chl 


BAG  OF  20 


M.00 


5  BAGS  $4.00 

Fl.  r»s.  «dd  sU.  tx. 

Add  200  per  bag,  Shipping/Handling 
No  C.O.OJs 


.ii^r^ 


f^aee 


Electro-Components  Division 

RO.  Box  5055,  Dept  73 

Ft.  Lauderdale,  FL  33310 


MICROWAVE  ANTENNAS&KITS 


iVIICROWAVE  TRANSISTORS 
AZ-EL  OPTION  KITS  •  " 
MICROWAVE  OIODES 

mRABOLIC  REFLECTORS 
ALUMINUM  FEED-HORNS 


Vbur  source  of  supplJeg  for  the  fastest  growing  field 

of  communtcalions-  Here  is  a  tow  costenlry  into  the 
fascinating  area  oJ  microwave  technology.  We  offer 
a  comptete  line  oJ  antennas,  receivers ,  pre- amps, 
power  supplies,  etc Call  or  write  for  details. 


DATA  SERVICE  COMPAMY 

3110  Evetyn  Street         i^346 
Roseville,  MN  55113 
612-636-9469 


Satellite  TV 

FOR  THE  HOME 


Sick  of  Network  TV? 

Our  r»c«lv«r  l«ti.  yoM  gal 
tmr  75  chsnrvala  ot  tftlAVh 
sicin  dirtcliy  Iram  wrth- 
otttlng  cabl0  TV  Mlallh«nh 
^BQ,  ShctwlLme,  sup«r  sl«- 
iinnm,   apofts   unci   nrovlsi 


We  don't  just  sell  information! 
We  {Manufacture  Hardware! 


Our  94-pag«  catalog  and  inloimatiofi  book  teN 
the  whole  story!  inexpensive  disties,  high  pro 
feeds,  computer  aiming  software!  Specs,  kits 
and  more!  Send  $7.95  today! 

24'hour  aO.D  HofUne       '  ^ 
(305)  339  7S00  r^C  "*««* 

SPACECOAST  RESEARCH  ^^^ 

Dept.  S,  P.O.  Box  442,  Altamonte  Springs,  FL  32701 


SLOTTED  ARRAY 

ANTENNA 


. 


^■i^i 


,^37fl 


•  2100  +/-100MHZ 

•  16dBigain 

•  14x  98  degree  beamwidtli 

•  H  or  V  polarization 

•  Type  N  connector 

•  Low  wind  loading 

•  Alodined 

•  24"x5'*xl" 

•  Mast  mount 

•  Superior  to  20"  d*sti 

•  Commercial  grade 

•  Mast  mount 


Postpaid , S35 

Optional  small  comer  reflector  narrows 
beam  width  to  14x14  degrees;  in- 
creases gain  4  dBl  FREE  PLAN. 


HVB 


1506  Ports  O'Call 
Piano,  Texas  75075 


SYNTHESIZED 

SIGNAL  GENERATOR 


•  Covets  100  to  179.999  MHz  in  1  kH;  steps  wjtti 
ttiumb-wheei  dial  •  Accuracy  .00001%  at  all  fre- 
qjericies  *  Internal  frequency  modulaticn  from  0  to 
over  1 00  kHz  at  a  1  kHz  rate  •  Spurs  arid  noise  at 
least  60(JB  below  carrier  •  RF  oytpul  adjustable  from 
50  to  500 mv  across  50  ohms  •  Operates  on-  12vdc 
@  Vi  amp  •  Price  $299.95  plus  shipping. 

In  stock  for  immediate  shipping.  Overnight 
delivery  available  at  extra  cost.  Phone:  (212) 
468^2720  ^^, 


VANGUARD  LABS 

196-23  J amacia  Ave.  Mollis,  NY  11423 


Radio  flmqtgurs! 


Tmipo  Handheld! 


S-tT 


S232.H0 
$260.90 
!l315.fKy 

$264.50 
:&2953.95 


2  M titer 

With  Toni'  Pad 

22X>  MHz 
With  '^(^nt'  Pad 
2  Mt'tt^r  5  Wiiti 
With  Jiinv  Fad 


2  Mtttr  *S5f}J)5    StAHS  C:.^PAIUMTV  \MTIt  MOD. 

SWAN  ASRo  \mi 

\m\i)\hur^  S995.00 

Astro  151)  $?.K5.0<) 

UHIM.X  $589,  W 

TEM-IEC  {>MHI  C  .v.,-«-i  |9t)B.[K} 

TEKirC&NMID  $79^. m 

Six  othf^r^  It nvor  priced  Umileil  Quanttties. 

— >,^   ArriiiUur  i'4:|uipiiloU  iiix\"sM^fiv>  &  anlwlUlA^- 
f:f)D\  USA.  tjt^rl  Aiiywhft^rv, 
.ArtiEU'iir  ^  fiiinniiircia]  repair  ?ifM  ice, 

2317  Vance  Jackson  Rd.San  Antonio,  TX  78213 

(512)734-7793       ^^^ 


10  METER  CONVERSION  KITS 
FOR  CB  RADIOS  AM-FM  &  SSB 

•  Kits  for  over  300  Models  of  CB 
Radios 

•  Low  Cost  from  $10.00 

Easy  to  ItistatI  with  All  Instructions 
Tune-Up  Procedure     Alignment 

•  KITS  FOR  MOST  POPULAR  UNITS 

Over  5,000  Satisfied  Customers 

•  Write  or  Call  Today  for  Our  Free 
1980  Catalogue 

AMERICAN  CRYSTAL  SUPPLY  COMPANY 


PC  Box  638 

W  Yarmouth,  IVIA  02673 

(617)  771 '4634 


1^7 


*^  Reader  Servfcs-^see  p^ge  22S 


73  Magazine  *  December,  1980     173 


Dear  Subscriber: 

73  Magazine  does  not  keep  the  subscription  records 
on  ttie  premises^  tiicrefore,  calling  the  Peterborough 
offices  doesn't  solve  your  subscription  problem. 

To  quickly  solve  your  problem  please  send  your 
most  recent  address  label  and  a  description  of  the 
problem  to: 

73  Magazine 
Subscription  Department 
PO  Box  931 
Farmingdale,  NY  11737 

Please  allow  the  subscription  department  at  least 
two  weeks  for  an  answer  or  a  solution  to  your  prob- 
lem. 
Thank  you  and  enjoy  your  subf^iTipliun. 

Sincerely, 


Debra  L.  Boudrieau 
Circulation  Manager 


Let  us  know  8  weeks  in  advance  so  that  you  won't  miss  a 
single  issue  of  73  Magazine. 

Attac^h  old  label  w^here  indicated  and  print  new  address  in 
space  provided.  Also  include  your  mailing  label  whenever 
you  write  concerning  your  subscription.  Ir  helps  us  to  serve 
you  promptly.  Write  to: 

73  Magazine  Subscription  Dept* 
P.O.  Box  931,  Farmingdale  NY  11737 


D Address  change  only  Dl  year  $25.00 

DExtend  subscription  DPayment  enclosed 

nEnter  new  subscription        DBill  me  later 

If  you  ha.i>'e  no  label  handy ^  print  OLD  address  Junre. 

Name  . Call 


Address 
City  


State: 


.Zip. 


print  NEW  address  here: 


N 


ame 


Call 


Address 
City  


State. 


.Zip. 


Selling  73  Magazine,  the  ham  radio  magazine 
that  offers  quality  and  quantify,  brings  the 
ham  into  your  store.  Once  through  the  door 
you  can  sell  him  anything. 

Our  dealers  are  telling  us  that  '11"  outsells 
them  all ...  so  call  today  and  join  the  dealers 
who  make  money  with  73  Magazine. 

For  information  on  selling  73  Magazine 
call  603-924-7296  and  speak  with  Ginnie 
Boudrieau,  our  Bulk  Sales  Manager.  Or  write 


to  her  at: 


♦^^J'^'** 


%^^S^^^ 


174     73  Magazine  *  December,  1980 


CORRECTIONS 


May,  1930 

''A    'Short' Yard'  Antenna    for 

40/75 — fits  where  others  wonT' 

The  spacing  between  the 
length  of  vertical  copper  or  alu- 
minum wire  shown  in  Fig.  1, 
page  78,  should  be  8  inches,  no! 
8  fee!! 

June.  1980 

**DQwn   With  Interpoiation—a 

digital  display  for  the  Triton  and 

others" 

On  page  36,  Fig.  1 » the  pin  6  of 
the  74196  shown  going  to  +  5  V 
should  fc>e  pin  number  10.  On 
page  39.  column  2,  line  2,  pins  to 
check  on  the  7490  should  be  8, 9, 
and  11. 

if  the  readout  displays  chang- 
ing random  figures,  the  crystal 
is  probably  not  oscillating. 
When  ordering  crystals,  it  is  al- 
ways a  good  idea  to  send  along 
a  schematic  of  the  circuit,  with 
values  indicated,  in  which  the 
crystal  will  be  used. 

As  stated  in  the  caption  for 
Fig,  3,  page  38,  there  are  fre- 
quencies  other  than  409.6  kHz 
which  can  be  used.  If  your  read- 
out works  on  all  bands  except  28 
MHz,  It  Is  probably  the  74C925 
which  is  at  fault.  This  chip  is 
specified  for  a  minimum  re- 
sponse of  2  MHz— typically  4 
MHz.  Since  the  mixer  frequency 
forthe  10-meter  band  is 2.1  MHz, 
your  74C925  may  have  a  re- 
sponse of  less  than  this. 

Brooks  Carter  W4FQ 
Irmo  SC 

July,  1980 

"ADDSCAN — flow  you  can  be 

two  places  at  once*" 


In  Fig.  2,  page  S2,  the  polarity 
of  C1  should  t>e  reversed  from 


V* 


what  is  shown.  We  apologize  for 
the  error  in  the  author's  call.  It 
should  be  WB9SFC. 


'*The  Sweet  Sounding  Probe 


f* 


The  reference  designators  for 
the  ICs  shown  in  Fig,  1,  page  84, 
were  omitted.  The  555  is  U1;  741 
is  U2;  and  78L12  is  U3. 


August,  fSflO 

"On  Ter}  FM — honre  of  the  free, 

land  of  the  brave" 

Vd  like  to  add  a  few  words  of 
clarification  to  my  article.  The 
best  source  Tve  found  fort  he  CB 
circuit  boards  is  Surplus  Elec- 
tron ics  (Miami,  Florida)  who  ad- 
vertise in  73.  Specify  the 
PTBM036AOX  CB  circuit  board 
with  40*channel  switch.  These 
boards  contain  the  easy-to- 
work-with  PLL02A  frequency 
synthesizer  PLL  chtp,  rather 
than  some  odd-ball  chip  for 
which  there  is  no  readily  avail- 
able data,  and  are  of  better  qual- 
ity than  other  boards  I've  seen, 
Sam's  CB  series  of  Photofacts, 
Nos,  CB-129  (Midland  13  8866) 
and  CB-131  (Hy-Gain  IX),  are  the 
best  sources  of  schematics  and 
technical  Information  for  these 
boards. 

John  F.  Sehring  WB2EQG 

Oradell  NJ 


September,  1980 
"The  Penultimate  CPO — a  non- 
discrete  LSI  device'' 

Pin  numbers  for  IC2b  were  in- 
advertently left  out  in  Fig.  2, 
page  62.  The  missing  numbers 
are  shown  in  the  accompanying 
diagram. 


TOfC 
ADJUST 


m 


\\i(M 


471 


SOX 


r-i 


MM 


'CENTER 

pfiEg 


vrr 
1 — ^i 


m 


lOOK 


n 


1  lOQK 


•90K 


HemsBd  Fig.  2,  ''The  Penuftimate  CPO.' 


October,  1980 

**NASA    Satelliles    You    Can 

Use— with   permission,    of 

course" 

In  the  math  box  on  page  52, 
the  calculations  for  Washington 
DC  should  have  indicated  that  X, 
the  difference  between  satellite 
longitude  and  site  tongitude, 
was  obtained  using  Washington 
DCs  west  longitude  of  77^  de- 
grees. 

Joseph  D.  Novak  K40VK 

Vienna  VA 


Map  of  States  Worked 

A  calming  note  to  our  readers 
In  British  Columbia  and  Michi- 
gan: No*  Vancouver  Island  has 
not  been  traded  for  the  Upper 
Peninsula. 


November,  1980 
"Direct  Conversion  Lives— ex- 
citingly simple  receiver  project" 

There  are  three  corrections  to 
this  article— the  easy  ones  first: 

On  page  66»  Fig.  3,  pin 6  on  the 
LM380  is  shown  m  two  places. 
The  pin  6  shown  as  being 
grounded  should  be  pin  4, 

On  page  68.  column  3,  8  lines 
from  the  bottom^  mH  should  be 
uH. 

Now  for  the  big  one!  Also  on 
page 68.  Insert  the  following  Just 
before  Audio  Filters  In  column  1. 

The  VFO  and  Buffer 

i  used  separate  vfos  for  80m 
and  40m  and  after  trying  several 
circuits,  I  chose  the  series-tuned 
Clapp  oscillator  because  of  its 
good  stability.  The  output  part 
of  the  vfos  and  the  buffer  are  ex- 
actly like  that  used  by  PAOSE. 
His  was  a  good  design  and  I  find 
no  need  to  change  it.  it  has  one 
weakness,  though:  Because  it  is 
a  broadband  buffer,  the  second 
harmonics  of  the  vfos  also  ap- 
pear at  the  mixer.  This  is  espe- 
cially true  of  the  80m  vfo  where 
the  second  harmonic  of,  for  ex- 
ample. 3.6  MHz  mixes  with  a 
very  strong  commercial  station 
on  7.2  MHz.  I  tried  a  40m  series- 
tuned  trap  from  the  drain  of  the 
FET  In  the  BOm  vfo,  but  it  cured 
the  problem  only  partially.  (This 
also  was  the  case  without  rf  am- 
plification at  the  front  end.)  I 
solved  this  problem  by  changing 
the  singletuned  input  circuit  as 
used  by  PAOSE  to  a  double- 
tuned  one  as  shown  in  Fig.  3. 


The  capacitors  of  this  double- 
tuned  circuit  are  two  gang-tuned 
35€-pF  variable  capacitors  (700 
pF  total)  and  the  inductances 
are  so  chosen  such  that  the 
3.5-MHz  resonance  occurs  with 
the  plates  nearly  fully  closed. 
Resonance  at  7,0  MHz  then  oc- 
curs with  the  plates  nearly  fully 


Audio  Ampttfication 

After  some  trials  with  other 
circuits.  I  agree  with  PAOSE  that 
an  FET  audio  amplifier  is  about 
the  best  device  for  a  first  audio 
stage  after  the  mixer.  The  audio 
transformer,  T2,  is  a  1k;tOk. 
which  is  far  from  ideal,  but  it 
was  the  only  one  available  tocah 
iy.  Far  better  would  be  one  with 
a  50  2:  10k  impedance  ratio,  as 
the  output  impedance  of  the 
MD108  is  50  Q.  The  final  audio 
amplifier,  the  LM360;  provides 
plenty  of  audio  and  is  better 
than  the  LM386  which  1  used  at 
first. 

"Tune  tn  the  Wind— a  do-it-your- 
self  hot-wire  anemometer" 

On  page  81,  column  4,  line  3 
would  make  more  sense  if 
''about''  were  to  be  replaced 
with  ''above." 

'*The    Odd    Couple— CASEY/I 
tackles  QSCAR's  telemetry'' 

In  column  4,  page  1 10,  the  last 
two  lines  of  the  article  refer  to 
the  article  listed  In  reference  2. 
The  reference  number  was  omit- 
ted from  the  last  line.  Also, 
please  note  my  new  address. 

Rich  Casey  WA9LRI 

1818  Hemlock 

Garland  TX  75041 

**Be  Prepared! — 30  meters  for 
the  FT-107B" 

Please  note  a  change  in  my 
address. 

Mark  H,  Monson  EL5Q/KB8NO 

Box  1046 
Monrovia,  Liberia 

"New  Weather  Eye  in  the  Sky — 
a  primer  on  NOAA's  TIROS" 

In  Table  1(t>)on  page  177,  sUb- 
point  latitude  for  76  minutes  af* 
ter  crossing  should  be  —01.1, 
not  -91.1- 

On  page  181.  column  1,  the 
first  sentence  of  step  3(A) 
should  read.  "Break  theconnec* 
tion  t)etween  the  vertical  size 
pot  and  the  input  line  of  the 
vertical  deflection  amplifier.'* 


73  Magazine  *  December.  1980     17S 


1980  INDEX 


AMPLIFIERS 

They  Don't  Make  'Em  Like  They  Used  To W20LU 

Shoes  and  Socks  for  the  lC-502....„. .,..N4QH 

A  Final  Sotution.,.» ,... W4ANL 

The  Two-Meter  Monkey.,, ., KL7GLK 

A  Conversion  with  Gusto., „., WB2WIK 

ANTENNAS 

The  Procrastinalor's  Special: 

A  SimpEe  Six-Band  Antenna... «.„w... W6TKA/0 

Rotary  Beam  for  10  or15:  the  18-2 .„„........„W6TYH 

The  20-Meter  Double  Bobtail W8HXR 

Simple  Switcher..,..,, ..,.„ WB5SFB 

Taming  the  Monster  Quad ,.,. » WA4JQS 

For  Cheapskates  Only:  A  No-Frills  Tilt-Over W9YFG 

WearYour  Halo  with  Style W9NMX 

Curtain  Raiser ....W2JTP 

Who  Needs  a  Rotator? W8HXR 

A  Tribander  for  the  Attic , , W4UCH 

A  "Short-Yard"  Antenna  for  40/75 W9CRC 

Antenna  Fans:  Try  the  Skeleton  Slot ,. Staff 

Stick 'Em  Up .,„„, , .WB2MYT 

Old  Fishermen  Never  Die....... 


h*-r<  k  *••  l-ai't-ii  *■'*'■«■•'•' t- 1 


,...WA4LLE 
Hustler  Minibeam; 

the  Mobileer's  Secret  Weapon K4TV\/J 

A  Beam  for  Less  than  a  Buck KA8CGE 

The  California  Crank-Up... „„......»...»„W6WDF 

The  Beachside  2-Meter  Beam. " K1QPS 

Double  Duty  Mag-Mount  Antenna ....K4IQJ 

A  40-Meter  Quad  for  $20..»» WA4JQS 

A  Dtrt-Cheap  Tower  Bas&.,.»-*v,„,*.„v...-..«»......WA5TDT 

Triband  Dual  Delta ....,WB6MMV/7 

Try  a  Fox  and  Hare  Special „..SVQWX 

Sheathe  Thyself WA8WTE 

A  Low-Life  Antenna AB5S 

AWiderWindom WA4PYQ 

Working  in  Wood ,......,....WB3ICL 

TheQRM  Klllen , ......„.„ ...,. ..,W9HBF 

The40'Meter  Band  Blaster .„. ,„..W9HBF 

The  Center-Fed  Bizarre N6RY 

The  Amazing  Bobtail.  . 

Our  Readers  Respond ,.,„..„„ W8HXR 


ATV 


The  Arcane  Art  of  ATV. 


CB  CONVERSIONS 

CB-to-10  FM— best  conversion  yet? 

..- „..,..... ..K1  DCS,  N1XN,W1WR0/N2XN 

CB-to-10  FM  Continued— 

another  way  to  join  the  fun  on  29.6 WB2EQG 

GB  to  10— part  XXII: 

more  talk  power  for  the  TRC-1 1 ,.  N4APN 

CB  to  10— part  XXIII:  the  Sears  Roadtatker40...W6SZS 

CB  to  10— part  XXIV:  Penne/sSSBrig,.... ,WA4UUV 

CB  to  10— part  XXV: 

using  those  surplus  40-channel  boards AF8B 

CB  to  6— 

convert  a  49-MHz  HT  into  something......... W9CGI 

CB  to  10— part  XXVI:  the  Cobra  132......»..»....WA1  UQC 

Ce  to  10— part  XXVII:  new  JifeforSSBCB  rigs.,.. N6SD 
CStolO-partXXVIM: 

double  your  channels  In  SSB  conversions WB2EQG 

On  Ten  FM— 

home  of  the  free,  land  of  the  brave. WB2EQG 

176     73  Magazine  •  December,  1980 


108 
66 

125 
84 

130 


106 
36 
44 
48 
50 
52 
58 
60 
61 
62 
78 
80 
83 
84 

104 
122 
131 
132 
134 
136 
138 
146 
148 
70 
134 

68 
116 

88 
179 

72 


Jan 

Apr 

Jul 

Sep 

Sep 


Jan 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

May 

Jul 

Jul 

Sep 

Sep 

Oct 

Oct 

Dec 


1 1 0      Dec 


.WB8DQT       50      Oct 


117 

Jan 

42 

Feb 

38 

Mar 

58 

Mar 

100 

Apr 

58      Jun 


148 

Jun 

72 

Jul 

108 

Jul 

122 

Jul 

52 

Aug 

Goin'  Mobile — equipment  for 

air-conditioned  gypsies...... KL7IPE/DA1SM,  DF7NM 

CB  to  10— part  XXiX: 

put  that  Hy-Gain  CB  board  to  use W1 BG 

CONSTRUCTION 

Go-Cart .W4MEA 

The  PL-259  Connection,. AC5P 

The  IC  Outener,..,,..,., WA4WDL,  WB4LJM 

Constructing  QRP  Dummy  Loads... W10LP 

PC  Artwork  Made  Easy .......W3HIK 

Rubber  Thumbs  and  Pilot  Lamps.. ...„„»». .K3MPJ 

A  Proper  Pedestal  for  PCBs ........Staff 

Silence  is  Golden... , ,, ,«. Powell 

Meet  the  Little  Giant , K4JHN 

Load  a  Lawn  Chair... ..WB5PPV 

PC  Boards— A  Photographic  Method,.. WB5HGR 

Cheap  Connectors  for  Half-Inch  Hardline WD4LWC 

CONTROL 

Personalize  Your  Repeater  with  a  Voice  ID.„ K9EID 

Personality  Pius  for  your  Repeater„^,,„„„ „„..K9EID 

Troubie-Free  ID  Timer.. ». WA8HEB 

Good-Bye  to  Autopatch  Hassles WB2LEI/4 

Repeater  Time-Out  Warning KA6A 

Get  Out  and  Vote WA9FDP/WR9ACD 

CORRECTIONS  AND  FURTHER  INFO 
"The  MiCROSIZER:  Computerized  Frequency 

Control"  (October,  1979)....-...... , 

"Yes,  You  Can  Build  This  Synthesizer"  (October,  1979) 

"Son  of  Keycoder"  (November,  1979) 

"What  Do  You  Do  When  Your  Rotator  Dies?" 

(November,  1979).... 

'The  Dollar^Saver  DVM"  (January,  1980) 

"Build  this  $50  Mini-Counter"  (December.  1979). „..«..,„ 

"The  Dollar-Saver  DVM"  (January,  1980),.... ..,. 

"An  LEO  Display  for  the  HW-2036^'  (October,  1979)....... 

"You  Can  Watch  Those  Secret  TV  Channels'* 

1 /x  LJ  \j  VJ    U  i.  ■  I     W    I      ^7jr  ■■^■■■rBiiiiirilb-illll-ill-l-LI-l-l-ll-l-l-IW  fV«  W  *«  »PI'llP'4«PII-IIFPqRP'»li'FIII 

"Neat  Readout  for  the  2036"  (March,  1980) 

"Lab-Quality  Hi  I  Supply"  (March,  1980) 

^'A  M  icro-Contfolled  Ham  Station"  (April,  1980) 

^'The  Paper,  the  Station,  and  the  Man"  (February,  1980) 

''Antenna  Engineer"  (May,  1980)..,. 

"Fun  with  Foozle"  {June,  1980)-. ».... 

H^reTix  witaiienge   (June,  i^70u)iMi •■■■■■■■i4..<«..H4i.*k...>>i 

"Cheapy  Scanner  for  the  MemorEzer"(Aprii,  1980) 

"Down  with  Interpolation"  (June,  1980).» 

"Electronic  Dice— A  Family  Pleaser"  (June,  1980)... 

"TheStoien  Rig  Retriever"  (June.  1980}... 

"A 'Short^Yard' Antenna  for  40/75"  (May,  1980) 

*'Down  with  Interpolation"  (June,  1980) 

"ADDSCAN"  (July,  1980) 

"The  Sweet  Sounding  Probe"  (July,  1980) 

"On  Ten  FM"  (August,  1980) 

"The  Penultimate  CPO"  (September,  1980),..,*. 

"NASA  Satellites  You  Can  Use"  (October,  1980) 

"Map  of  States  Worked"  (October,  1980),. 

"Direct  Conversion  Lives''  (November,  1980) 

'Tune  In  the  Wind"  {November,  1980) 

"TheOdd  Couple"  (November,  1980). .,»».». 

"Be  Prepared!*'  (November,  1980)..,.w„».,.......-v.*..i. 

"New  Weather  Eye  in  the  Sky"  (November,  1980), ,... 

cw 

Sound-Sensitive  CW  Sender,.. .....W2GZ 

QRQ,  QRS— By  the  Numbersh»„„. W7BSX 

Check  Chirp  with  a  Choke ......WA2MEU6 

Build  the ZL  Paddle ZL2GA 

The  Confidence  Builder »».. wa4TYL 

Double-Duty  CW  Keyboard.... ..K1GN 


76 

Sep 

102 

Sep 

134 

Feb 

73 

Apr 

150 

May 

64 

Jun 

80 

Jun 

114 

Jun 

120 

Jun 

91 

Jul 

46 

Aug 

60 

Sep 

104 

Oct 

100 

Dec 

92 

Jan 

136 

Jan 

76 

Feb 

30 

Mar 

120 

Jul 

64 

Sep 

146 

Jan 

146 

Jan 

154 

Feb 

147 

Mar 

147 

Mar 

147 

Mar 

132 

Apr 

132 

Apr 

132 

Apr 

159 

May 

195 

May 

180 

Jun 

180 

Jun 

160 

Jul 

160 

Jul 

160 

Jul 

166 

Aug 

166 

Aug 

166 

Aug 

166 

Aug 

175 

Dec 

175 

Dec 

175 

Dec 

175 

Dec 

175 

Dec 

175 

Dec 

175 

Dec 

175 

Dec 

175 

Dec 

175 

Dec 

175 

Dec 

175 

Dec 

175 

Dec 

106 

Apr 

50 

Jun 

111 

Jun 

118 

Jul 

134 

Sep 

126 

Dec 

EQUIPMENT  MODIFICATIONS 

A  Brasspounderrmproves  Heath's  HR-1680.......,KA5N 

The  Nearly  Perfect  WE-600 „„... K10TW 

Catch  You  on  the  Flip-Flop „ .^^ K7ACN 

Add  "Em  Up:  An  IC-22S  Programmer _.AA4RM 

Gone  But  Not  Forgotten , .AD5X 

Neat  Readout  for  the  2036... ,.-...»„..K3GRX 

Modernize  That  Boat  Anchori.... . *AD5X 

Cheapy  Scanner  for  the  Memonzer„„«..„„„.,WA20RU 

Hi-Fi  CW  for  the  TS-820.» ».,.».„».,„. K3H8P 

SWLing?  Try  This  Souped-Up  SSR-1 -„,.»„„. G3WDr 

Off  the  MARS  wflh  theS1„-™„ K5EDS 

Down  wtth  Interpolation , ...W4FQ 

The  Phoenix  Ffx „ „,,,, .„WA3AJR 

Adding  a  Scanner  to  Your  2m  Rig ...WASHES 

The  IC-21 1  Cookbook ,„..K3VGX 

Priorily  Frequency  Power-Up 

for  the  FT-227R.„, .„,„„„,„ „.._. .WA1AUM 

10  Meters  for  the  SB-221...... .„.„„WA2KSM 

Outboard  Power  for  the  820 KL7GRF/6 

Digital  Boat  Anchor .„„ „. ...WB1ASL 

Top-Banding  the  DX-60B— part  I WB1ASL 

FT-227  Update,„„,„„„ „. WAlGPO 

Triton  IV  Quick  Tricic ,..„.„.„,AG4R 

Who  Needs  SSB? .„_.K8JS 

How  to  Make  a  Good  Scanner  Better„,„,„.„,..WA4PYQ 

Gilding  the  Lily _ „„„„„„.„.WB4HI_Z 

Mike  Mods  for  tti©  KDK-2016A„- „„„«WB9WNU 

Getting  the  SB-220  to  Idle „.*. W9RY 

Be  Prepared  I.. .„„„...,„ „„.„„„.„„ „„.KB8NO 

Top-Banding  the  DX-60B— pami,„. WB1ASL 

Clean  Sweep  for  the  FT-221 ™„,,„„,,..WB<JLLP 

Scanner  Magic  for  Heath's  2036. , WA4BZP 

Singje-Tone  Pagmg  for  Wtlson  NTs «™ ,W4BF 

GADGETS 

A  Better  Car  Regulator. «. „.Gelsinger 

Fieid-Strength  Fever ..., ,„,, W6D0B 

The  Stolen  Rig  Retriever. , .„„„WB6KBM 

Electronic  Dice— a  Family  Pleaser „... W7BBX 

Fun  with  Foozle. „..,„„,.„„. W7BBX 

Listen  In  Secrecy 

with  a  Giant  Inductive  Loop ZL2AMJ 

Transform  Noisy  Fluorescents ..» W20LU 

The  Penultimate  CPO N6HI 

The  Two-Hour  Audio  Amp *„.„...., K7HKL 

The  Little  Thinker. WB4RXB 

Undertones .» W4FEC 

Field  Strength  for  Free ,.,*.*.•*.««**, Staff 

Stay  Cool  with  TM„„ „ .WB2EQG 

Tune  In  the  Wind. .,.,, VE7DKR 

An  Amp  for  QRPp  Addicts, „,„ ..„„..WA(IRBR 

Build  a  Talking  Digital  IDer...„™„. -«,„-.„..K20AW 

HISTORY 

The  Paper,  the  Station,  and  the  Man»„... .»W3CFC 

Albert  and  his  Momentous  Theories,,,,. ,,„.... Lutus 

The  History  of  Ham  Radio— part  XI... W9CI 

Early  Radio  Detectors— A  Backward  Glance W5JJ 

'That*s  the  Way  It  Was. , ." .„... ...K2VGV 

Notes  from  Big  Sky  Country .••„•„ K6CK 

Those  Fabulous  Fifties,,, ,„»„». W1 FK 

Over  There ™.... ,„„™,. >„,™ W9IWI 

One  Man's  Magazine:  Twenty  Years  of  73...... ..».N1AUI 

Who  Really  Invented  Radio?. .WB2NEL 

HUMOR 

Future  Rig  and  Rigamarole W6HDM 

Let's  QSY  to  .52 „.WB2RVA 

A  Transistor  for  True  Believers, „,.,.„„„„„WB7CMZ 

How  To  Be  An  Amateur.,.*..... ,.•.•,- „„„W2ZGU 

Ox/rTIC'    ^3%jy^     nrlQl^C    ll*«.<.i.,.ii,»BKBBBHUK.f ■■-■■■■■■■■,»*HBBAa«ai,kT\j_\./riO 


76 

Jan 

96 

Jan 

132 

Jan 

103 

Feb 

48 

Mar 

62 

Mar 

66 

Mar 

38 

Apr 

70 

Apr 

92 

Apr 

96 

Apr 

36 

Jun 

48 

Jun 

54 

Jun 

68 

Jun 

90 

Jun 

134 

Jun 

146 

Jun 

152 

Jun 

44 

Jul 

74 

Jul 

126 

Jul 

130 

Jul 

68 

Oct 

188 

Oct 

190 

Oct 

197 

Oct 

156 

Nov 

64 

Dec 

82 

Dec 

SB 

Dec 

112 

Dec 

58 

Apr 

98 

Apr 

60 

Jun 

82 

Jun 

84 

Jun 

124 

Jun 

64 

Jul 

62 

Sep 

118 

Sep 

126 

Sep 

56 

Oct 

82 

Oct 

144 

Oct 

ao 

Nov 

68 

Dec 

162 

Dec 

54 

Feb 

116 

Feb 

54 

Maf 

66 

Jul 

78 

Jul 

36 

Aug 

64 

Aug 

86 

Aug 

146 

Oct 

36 

Dec 

44 

Mar 

44 

Jun 

142 

Oct 

156 

Oct 

168 

Oct 

I/O 

HowtoWritea  RTTY  Program., ,„„„.. WA4FM2 

The  Perfect  Morse  Machine „.„.„... WA5VQK 

Microcomputers  and  Your  Satellite 

Station— part  I........ .„ -,„„„. ,WB8DQT 

Microcomputers  and  Your  Satellite 

Statfon-^part  II _„ ...,WB8DQT 

Design  Practical  PLL  and  Tfmer  Circuits... ....N2RG 

OUPECALL. .  .for  Your  Next  Contest , K4TSY 

COM PU LOG:  A  Multi-Purpose 

Record  Keeper.. „ .....WA1ZSE 

Computer  System  I/O  Interface , ...VE3CAF 

Number  Fun  on  your  Micro ...W3KBM 

Baudot  Message  Formatter. , .W6RLL 

A  Micro-Controlled  Ham  Station. ..W4UCH/2 

CW  and  the  TRS-80 „„.. WB7TUG 

Breakthrough?  A  Computerized 

Antenna  Rotator!.... K3LR  WB3CTZ 

Antenna  Engineer., ,-».„„. , K8UR 

SWTP/H 14  Get-Together.... ...„,.*.- WA8GRG 

Computerize  Your  Contest  Paperwork WA8WIA 

Emulate  an  Elephant., VE6BB 

Prefix  Challenge .AG6P 

Welcome  to  the  '80s,,,..,, ,„„ .....K3PUR 

A  Soft  Approach  to  Logging...... .„.„.. .Minor 

mVf  with  the  H8 „„«.. ....W5IFQ 

A  Programmers  Potpourri,,.,..*... K20AW 

Late  Check-Ins  Come  Now ..„„ „.„-.„N8AD 

A  Computer-Controlled 

Talking  Repeater— part  l.,„ .„.*...... WA6AXX 

Murphys  Own  OSCAR  Tracker™^ K8BG 

The  Odd  Couple,,..,. ........WA9LRI 

PL  Tones  froma  KIM-1 .,., , ..WD8CHH 

Super  Duperfor  Field  Day........ .......__....WB5KVZ 

A/D  Converters  Explalnedt WB4UHY 

A  Computer-Controlled  Talking 

Repeater— part  IL.,.„ „„...,-....... ...WA6AXX 

Sixteen  Channels  of  Digital  Delight.,. WB4UHY 

A  Computer-Controlled  Talking  Repeater — 

Make  a  Microcomputerlst  Smile .AL7G 

MISCELLANEOUS 

DX  with  a  Difference- the  Utility  Stations ..,WA3E0P 

Home-Brew  Holders  for  Icom  Portables .KH6I AA 

Sunspot  Predictions  for  1980 ....WA3NKP 

Excavation  Litigation.. , Hecht 

On  the  Trail  of  the  Hamburglar ..WfflEX 

Sunspols,  .  .What  Do  They  Mean?,.,. G3WDI 

More  on  Jammer  Nabbing......... .....„WB0CMC 

Hams  on  the  TrafI  of  UFOs K8NON 

The  Demise  of  Component  Stores.. ........VE3FLE 

Another  Place*  Another  Time Anon. 

The  Rites  of  Spring N1AUL  WB8BTH.  KA1HY 

All  About  Coordinated  Universal  Time, WA7NEV 

Ham  Economics:  Selling  Used  Gear K5CA 

Like  to  See  My  Etchings?.„„„„„«*.„*„„.„ „..W60J  J 


In  Profile:  Dick  Bash  KL7IHP,., .N1AUI 

Escape  from  Mt^St.  Helens! W7WFO 

Sheila  Ran] „..„, .....WB0IFF 

The  First  Man  in  Space  Was  a  Ham ,..W1QMS 

Win  Friends  for  Your  Club ..,....„ „._....WA5TUM 

Welcome  Back.  Barry!........,,.*,. .,*., ,.K7NZA 

Return  to  Shangri-la ..*»*...„ ,W1QMS 

An  Even  Better  iC Timer... *„... , WA0PBQ 

MOBILE/PORTABLE 

The  Soft  Mount •.,<„,,„ .,••„., ....W2QFC 

Power  X  2. . .  Plus! .„.- WA5TDT 


NEW  PRODUCT  ARTICLES 
The  Europa^B  Two  Meter  Transverter ...G3ZCZ     110     Jan 

73  Magazine  *  December,  1980     177 


46 

Jan 

63 

Jan 

63 

Jan 

66 

Feb 

92 

Feb 

96 

Feb 

74 

Mar 

78 

Mar 

80 

Mar 

82 

Mar 

76 

Apr 

80 

Apr 

86 

May 

96 

May 

100 

May 

94 

Jun 

96 

Jun 

104 

Jun 

92 

Jul 

100 

Aug 

106 

Aug 

90 

Sep 

120 

Oct 

124 

Oct 

132 

Oct 

110 

Nov 

112 

Nov 

114 

Nov 

122 

Nov 

132 

Nov 

132 

Dec 

138 

Dec 

148 

Dec 

40 

Jan 

131 

Jar> 

47 

Feb 

72 

Feb 

116 

Mar 

32 

Apr 

36 

Apr 

68 

Apr 

86 

Jun 

136 

Jun 

30 

Jul 

80 

Jul 

124 

Jul 

132 

Jul 

40 

Sep 

34 

Oct 

38 

Oct 

42 

Oct 

76 

Oct 

52 

Nov 

58 

Nov 

46 

Dec 

32 

Aug 

122 

Sep 

fr4i#44#  V«fl  ■»«•*«-««««'«  41  4  '< 


■  ■iilB-riaai 


Ftf«  *'-#««  I 


■■^■■'fVV-«««!PiHBVll««BBV  ««'  ' 


6m  Fun  with  the  FT-625RD...,,..„, ,„W60JF 

Going  2m  All-Mocle  with  Yaesu^s  FT'225RD W60JF 

Tempo  S1  2-Meter  Portable..... .„ WB9HRV 

Those  Hamtronics  Kits.  . . 

How  Can  You  Use  Them?..,,,., WA4PYQ 

The  Don  Nobles  Descramblers...,i.*.;«..,..fc.;*....WA4PYQ 

tnside  Radio  Shack's  Digital  Receiver..... .W4PGI 

Automated  Operating  Comes  of  Age K3CMV 

NEW  PRODUCT  SECTION 

AzdenPCS'2000  Transceiver „ 

DSI 5600A  Frequency  Counter. *. 

AEA  Morsematic  Keyer „ 

EP-8  Pocket  Shortwave  Receiver 

OK  Machlneand  Tool  Mini  Shears.,.. 

Curtis  IM-480  Keyer 

Ten-Tec  Model  299  Talking  Counter ,„.. 

Optoefectronics  Frequency  Counters.... 

Discoil  HF  Mobile  Antenna... 

Info-Tech  M-200E  Tr^Mode  Converter... WA4PYQ 

Yaesu  FT'207R  HT  (2m)„..._, , K4TWJ 

DSI  50'H2-500  MHz  Pocket  Frequency  Counters. 

Heath  1680/1681  CW  Receiver/Transmitter ,,.. 

Fox-Tango  Crystal  Filters ,. , 

Fotografix  Magnetic  Signs.. 

Hamtronics  Catalog 

OK  Machine  and  Tool  BW-2630  Wrapping  Tool 

BullelZulu  Clock  Kit , , 

Selectone  Multi-Frequency  Encoder .„.. 

RadioShack  Wireless  Remote  Control. 

Heath  2-kW  Antenna  Tuner.. , ,.... 

Clutterfree  Modular  Consoles. ,.„.,.. WA4PYQ 

Macrotronics  M650  RTTY  Interface  Unit WSFX 

M  F J  P h o n  e  P ate  h es  — „v;, .,, , ..; .  .,„„,». .  W A 4  P YQ 

AEA  KM-1  Keyer ..,,....„... 

Kantronlcs  Field  Day  Morse/RTTY  Reader... 

OK  Machine  and  Tool  Prototype  Boards 

SkytecCW  Speaker... .„....r*,»...,i K4TWJ 

KLM  KT-34XA  Triband  Yagi..„„^,„i.w....^.,^.». 

Prat  Moss  VHF  Transmitter ..........WA4PYQ 

OK  Machine  and  TooIJust  Wrap  Kit.. 

DenTronGLA-1000  Linear  Amplifier „.., 

Heatli  Remote  Coax  Switch , ..., 

Bird  Digital  Rf  Wattmeters 

Bullet  SE  01  Sound  Effects  Generator..... -.,.,..N4XX 

MSCOMM  BTA-1  RTTY  Control  Center ..., 

Azden  PCS-2000  2m  FM  Transceiver.. ...WAOOKV 

Pace  Communicator  MX  HT.. KA5ECP 

Kenwood  TR-240O  HT... N6H1 

Spectrum  TTC100  Decoder/Control. 

Telex  HDR300  Rotator.......... 

Hustler  G7  220  220-MHz  Base  Antenna.^,, 

Heath  SA-7010  Triband  Yagi, 

Communications  Specialists  TE-12P  Encoder,-.,,*.,.,.,,. 

Regency  K500  Programmable  Scanner WA4PYQ 

Microcraft  Morse-A-Word  Code  Reader , 

AEA  Morsematic  Keyer WB8BTH 

Global  Specialties  Wire  Kit. 

Amerex  Unibox  Packaging  Components 

Grove  Enterprises  Frequency  Directory , 

Te n- Tec  Argonaut51 5,.„,„„, . ....^* 

lcomlC-2AHT ,..„.,,, WB6TOV/1 

Technical  Clinic  Ham  Scan-2...,. ,.WD8JLW 

THS  Electronics  PA  1-10  2m  Amp 

Larsen  Kulduckie  Antennas....... 

XitexUDT-170TU , ..,,.,, 

Robot  Model  650  Scan  Converter ..,.. 

Micro  Control  Specialties  Mark  3CR  Repeater.... 

Ten-Tec  Hercules  Linear  Amp 

B  &  W  BC'1  Batun....... ,. 

Trac  Model  TE-292  Keyer 

Kantronics  Signal  Enforcer  Audio  Filter. 

178     73  Magazine  •  December,  1980 


" '  '•mi*  m  i-  tfi  >'•  s  *t*  ■■ 


114  1  *m  ■■  d  •■  A  «  i 


p-7-«'q'«-|P4'W «■.«-«  SI  «■'■'■>!■' y  « 


■  ■  ■  "^  4  «  ■  frIJJ   kl-l-t   ■■■4'1-ldri-llildd  M.m  ■  A  h  ■  ■ 


■P^VVi-l-BI 


■Vt¥PTFPI-BlifeKnBfeflllkBfei:»tai 


114 

Feb 

72 

Apr 

118 

Jun 

130 

Jun 

148 

Jul 

80 

Sep 

170 

Nov 

26 

Jan 

26 

Jan 

26 

Jan 

147 

Jan 

147 

Jan 

147 

Jan 

148 

Jan 

148 

Jan 

34 

Feb 

34 

Feb 

145 

Feb 

147 

Feb 

148 

Feb 

148 

Feb 

148 

Feb 

149 

Feb 

149 

Feb 

149 

Feb 

149 

Feb 

26 

Mar 

26 

Mar 

26 

Mar 

27 

Mar 

145 

Mar 

145 

Mar 

146 

Mar 

146 

Mar 

147 

Mar 

28 

Apr 

28 

Apr 

28 

Apr 

28 

Apr 

29 

Apr 

29 

Apr 

162 

Apr 

26 

May 

190 

May 

190 

May 

191 

May 

192 

May 

192 

May 

192 

May 

193 

May 

193 

May 

193 

May 

194 

May 

22 

Jun 

23 

Jun 

23 

Jun 

23 

Jun 

166 

Jun 

166 

Jun 

166 

Jun 

168 

Jun 

168 

Jun 

169 

Jun 

26 

Jul 

26 

Jul 

26 

Jul 

28 

Jul 

28 

Jul 

26 

Jul 

KLM  SSV  80-40-15  Triband  Vertical 

Hust[er5-BTV  Vertical  Antenna 

Bearcat  Four-Six  ThinScan  Scanner. 

Hy-Gain  Catalog ..., -.....,.,......,.. 

Hustler  MKR-2  2m  Fixed  Station  Mounting  Kit .,. 

Heathkit  SA  2040  Antenna  Tuner K4KY0 

Spectrum  Communications  ID  1000  CW 

Station  Identifier ,.. 

AEA  KT- 1  Keyer  Trainer., ,„„„,,«,.„ WB8BTH 

Hamtronics  Converters  and  Amps 

Collins/Rockwell  KWM-3S0  Transceiver.,..,.„....K4TWJ 
Kenwood  R-1000  General  Coverage  Receiver 

WA4PYQ 

i^'l  p-H  ■«■■■■#■  d  i  ■■■■  i  It  ■■#'■>  I  "i  ■■■  fa  ■    1    Vf    ^  ^r  P        n     \Jt 


:  i  i^-iv^-fH^w^iaifldii-iavql-ii^ 


Peripheral  People  Software................................ 

KLM  40-10V  Multiband  Vertical.. 

RSGB  World  Prefix  Map... N8RK 

Swan  Astro  102BX  Transceiver N8RK 

Con-puter  1  Memory  Keyer 

loom  fC2AT  Synthesized  Handje-Talkie..... K4TWJ 

SoundpowerSPlOO  Speech  Processor.,,,.,,, N8RK 

Microcraft  RTTY  Reader. 


■  n-  r-w*  ■  *«««-Piv«  r  ^  V  •fwn 


F  m  ^t^'mw^-ti-m-ti  dJk  '**%  b  i 


Instant  Software  "QSL  Manager"  Software ...N8RK 

Circuit  SpeciaHsts  Repeater  'Tail  Chopper"...........,..,.. 

Grove  Enterprises  Sounds  of  Shortwave 

Cassette , .........NSRK 

Hy-Gain  HG-70HD  Tower  and  Accessories 

Archer  Engineer's  Notebook 

P.  C.  Electronics  TVC-4  ATV  Downconverter, .,.,,,.„ 

Heathkit  HDP-1473  Allband  Verticai v.twv.**.,,., 

Azden  PCS-2800  10-Meter  FM  Transceiver. W1GV 

Hickok  LX304  Digital  VOM „.,, 

Radio  Shack  Safe  House  Alarm  System......... .....N8RK 

Ten-Tec  Omni-C  Transceiver .„.,-,;.„..;........». 

Spectrum  Communications  SCR4000 

UHF  Repeater ,....„„,.,..„. „ 

MFJ  Model  959  Receiver  Antenna 

Tuner/Preamplifier..... ...„.„,.„ WA4PYQ 

Hamtronics  CA  Series  Receiving  Converters 

Drake  R7  General  Coverage  Communications 

Receiver... .„„-.,.,„.„„., WA4PYQ 

Radio  Shack  DX-302  General  Coverage 

Receiver... .,.........„....„„,, WA4PYQ 

Mirage  Model  B23  2-meter  Amp.. 

Jameco  J E610  ASCII-Encoded  Keyboard  Kit. 

Grove  Enterprises  VHF/UHF  Scanner  Beam....^.. 

Heathkit  Frequency  Counter  Line ....„ ,.„.... 

International  Crystal  TV-4300  Sateliite  Receiver 

COMMSOFT  RTTY89  Software „., 

Teltone  DTMF  Decoder ,., , 

Kantronics  Fiefd  Day  2  RTTY  Reader,.. WA4PYQ 

R.  H.  Johns  Current  Shunts  for  DMMs 

Palomar  Engineers  Antenna  Tuners ,.„N8RK 

ETCO  Catalog .„. .„, 

Radio  Shack  Space-Saver  Desk , KBONV/1 

MFJ  Model  1020  Active  Antenna , WA4PYQ 

Shure  Model  444D  Microphone 

Micro-80  Amateur  Radio  Theory 

Review  Software .„..„.. ....KAOBYS 

AEA  Model  CK-1  Electronic  Keyer 

Jameco  Desk-Top  Enclosures „.,*,-^:„„ 

Heath  ICTimers  Self-Instruction  Program 

Hamtrontcs  VHF  FM  Exciter  Kit,,,,, ,., 

Centurion  Antennas ,. ..„„„„.„..,..„.„ 

Gilfer  NRD-515  Allband  Receiver _... 

Sony  ICF-2001  General  Coverage  Receiver.... WA4PYQ 

B&W  T2FD  Folded  Dipole....... WA4PYQ 

Karetron  SC'76  Scanning  Module 

OPERATING 

QRP  from  Canton  island KH6GB 

Hurricane! 8P6KX/9Y4JW 


156 

Jyf 

156 

Jul 

157 

Jut 

157 

Jul 

157 

Jul 

30 

Aug 

30 

Aug 

30 

Aug 

31 

Aug 

31 

Aug 

31 

Aug 

162 

Aug 

162 

Aug 

183 

Aug 

163 

Aug 

32 

Sep 

34 

Sep 

34 

Sep 

36 

Sep 

37 

Sep 

38 

Sep 

38 

Sep 

38 

Sep 

39 

Sep 

160 

Sep 

30 

Oct 

30 

Oct 

30 

Oct 

32 

Oct 

32 

Oct 

242 

Oct 

242 

Oct 

243 

Oct 

243 

Oct 

32 

Nov 

32 

Nov 

36 

Nov 

36 

Nov 

36 

Nov 

37 

Nov 

38 

Nov 

38 

Nov 

38 

Nov 

38 

Nov 

40 

Nov 

40 

Nov 

41 

Nov 

41 

Nov 

196 

Nov 

197 

Nov 

197 

Nov 

32 

Dec 

32 

Dec 

186 

Dec 

186 

Dec 

186 

Dec 

186 

Dec 

187 

Dec 

188 

Dec 

188 

Dec 

63 

Feb 

68 

May 

The  Pope  Comes  to  the  Cornffefds .WD©AKB.  AK0Q 

Take  a  Hike K4FD 

The  Rains  of  Morvi ........,„ .,„„VU2ST 

Trash  All  Your  Wornes.,..,. ..,,,„, „„„„„. „WA5TUM 

Busman's  Holiday...™ - , K4BKKA/P1 RS 

*'No  Problem, .  .No  Problem" ._.„„„..,..,.„. W4LVM 

Hams  vs.  Hurricane  Alien.,,, ,.»«. N8RK 

The  Radio  Spectrum  at  a  Glance... *•.••*. .**,..WA4PYQ 

A  New  Frontier„.„.„ *„ -„„„„.„..„, .K4TW J 

POWER  SUPPLIES 

A  Better  Overvoftage  Protection  Circyil....*,*..,,.W7RXV 

Lab-Quality  Hi  J  Supply— part  I..., ,.,. McClelfan 

Lab-Quality  Hi  I  Supply— part  IL»» „„„„McClerfan 

When  Pius  Goes  Minus„.„ -....„„ . ..Minchow 

Depolarize  that  Power  SupplyL... ,«.»»AA6C 

A  Different  Kind  of  Charger ,..,,.. WB6MXD 

Bridge  Over  Troubled  Audio ,.K4IPV 

The  Battery  Mmder*».i„,>,..**^**,^;»„„»„*,»„,„, ,„,;,,,,, K4GOK 

RECEIVERS 

Reawaken  that  Sleeping  Rx. .....,.„.* Sara 

Forward  into  the  Past! ,.....W5JJ 

Old  Receivers  Never  Die , W4ANL 

In  Search  of  the  Elusive  SES , WA3UER 

RTTY 

Baudot-ASCII  Converter  Follow-Up......VE4YD,  VE4CM 

Moving  Display  ASCM  Readout,,.,, ,„•*-„„„ W8VL 

A  Solid-State  RTTY  KeytKiard ...„-».,K2BLA 

A  Tlghtwad^s  FSK  Demodulator,*..,..*. .«.«.WA5WPQ 

Hooray!  An  A  FSK  Auto  IDer!...„.^.„„,„„.... , K3IJ 

RYRYRYRY. ,...,.,....,........„„., ..„..Minchow 

FtTTYQSK „ CT1EM/PY1AQL 

SATELLITE— OTHER  THAN  OSCAR 

NASA  Satellites  You  Can  Use .-..„ K40VK 

Direct  Printing  FAX— part  i,..,., „..„,.WB8DQT 

New  Weathef  Eye  in  the  Sky.. „„„....WB8DQT 

Direct  Printing  FAX— part  11,. „,„... .WB8DQT 

The  Microwave  Midget..,. , W3KH 

SURPLUS 

Surplus  Treasures K1VfC/2 

TECHNICAL  AND  THEORY 
NBVM:  Dawn  of  an  Era  or  Promotional  Hype?..,..N8RK 

How  to  Make  Your  Own  Crystal  Filters....... .....Staff 

Zero  In  on  Zero  Beat „»W20LU 

An  End  to  Dials  and  Meters?.... ,.. Staff 

In  Search  of  Power  Line  Interference „„„„.- W4PZV 

Hard  Copy  from  your  Xitex  Terminal „.« W5SBL 

Noise  Rejector  11..^^,...,^,... ............. -WB6ZYK 

Working  with  FETs ..WA2SUT/NNN(JZVB 

The  L  With  It ,.--. ................^ .„.K4KI 

Ham  Shack  Numerology.... ,..„,„ ........W6HDM 

A  Do-It- Yourself  Speech  Compandor W6TNS/7 

Morse  Converter  for 

Frequency  Displays ..WA6AXE/KH6 

Back  to  SchooL„„. , .W6HDM 

Home-Brew  Rf  Impedance  Bridge.,., WB6BIH 

VHP  Signal  Diffraction.. ,...W5GFE 

The  CapacHive  Coaxiaf 

Ground  Wire,... DA1TMAA/D9HBB 

Confused  About  Phased  Arrays? .»„„„........ W5JJ 

One  Step  at  a  Time: 

Designing  Your  Own  Ham  Gear — part  I... W4RNL 

Tuning  Antenna  Mounted  Preamps... „.,.... Staff 

Who  Needs  a  $40  Soldering  Iron? ..Staff 

One  Step  at  a  Tfme: 

Designing  Your  Own  Ham  Gear— part  N W4RNL 


t08 

May 

74 

Jun 

60 

Aug 

70 

Aug 

96 

Aug 

122 

Aug 

70 

Nov 

142 

Nov 

64 

Dec 

140 

Jan 

B8 

Mar 

54 

Apr 

56 

Jul 

58 

Jul 

60 

Jul 

115 

Aug 

56 

Sep 

112 

Sep 

112 

Jun 

48 

Jul 

111 

Sep 

42 

Dec 

34 

Mar 

46 

Apr 

BS 

Apr 

106 

Apr 

42 

Jun 

70 

Sep 

38 

Sep 

50 

Oct 

90 

Nov 

176 

Nov 

52 

Dec 

106 

Dec 

122 

Jun 

30 

Jan 

98 

Jan 

112 

Jan 

50 

Feb 

66 

Feb 

70 

Feb 

74 

Feb 

82 

Feb 

40 

Mar 

70 

Mar 

96 

Mar 

107 

Mar 

40 

Apr 

30 

May 

56 

May 

82 

May 

118 

May 

28 

Jun 

78 

Jun 

144 

Jun 

36 

Jul 

Don't  Be  a  dB  Dummy! McMahan 

The  NMX  Relay  Deceiver. W9NMX 

Thai  Mysterious  Mode:  10  FM „. WB2EQG 

Free  CMOS  Timers ......WD5DDR 

\^  f  \i^  L#  Pi      "t#  I  Ig^ViP  l<\  10  ■4«fl««'a«ii'BBfla'»*iHnB-w»wivw«>«'««PHHPBBBBia-»w*v*«V!ni«fl«-B'«BHi|i+  r\*T  I  1^    w 

Egad!  An  Easy-to-ByildSynthesizerL,., .,„„N4CEY 

Direct  Conversion  Ltvesl. ZS6UP 

HV  Power  Rectifiers... ,WB2UIK 

Teletext  and  Viewdata: 

Are  Vou  Ready  for  the  Information  Boom? WB9KPT 

TEST  GEAR 

Frequency  Counter  Survival  Course *.,..McClel[an 

The  DollarSaver  DVM ,.., ..........McCleHan 

The  Oscilloscope  Sun^ival  Course »**,„..„..McCleHan 

Test  Gear  Bargain  from  Heath.,,......,..... ..-«...Staff 

Semiconductor  Test  Gadget Truesdale 

Build  an  Audio  VOM.. „..„,..., AC5P 

Measure  Frequency  on  your  DVM. .»...,» W3HB 

Five  Test  Equipment  Bargains  from  Heath... ...,W2QFC 

Digital  Transistor  Checker, W4QBU/PY2ZBG 

The  Sweet  Sounding  Probe ,»........ W7BBX 

The  Multi-Media  Bench  Tester.... ...,. .WD4KFF 

Counting  with  Class ..,..WB4EKB 

Build  a  Better  Battery  Tester...... ...........^.^..Staff 

VSWR._  Automatically!...... .....,,..,...  WBIBGWP 

Breadboard  Signal  Generator ,...K3QK0 


82 

128 

44 

113 

192 

210 

64 

92 


Jul 

Jul 

Sep 

Oct 

Oct 

Oct 

Nov 

Dec 


120     Dec 


A  600-MHz  Universal  Counter,,, 


•-#*  •**•*+*«««**»««* 


,..,.-W4VGZ 


36 

83 

106 

62 

64 
104 

115 

46 

56 

84 

106 

134 

196 

42 

100 

58 


Jan 
Jan 

Feb 

Apr 

Apr 

Apr 

Apr 

Jun 

Jun 

Jul 

Jul 

Oct 

Oct 

Nov 

Nov 

Dec 


TRANSMITTING 

So  You  Want  to  Build  a  Beacon?..... 


..K9EID        78      Feb 


VHF  AND  HFGHER 

Two  Dollars  a  Tone.... ,...K88CL 

The  World  Above  430— part  I ....W9CG1 

The  World  Above  430— part  II...... .......W9CGI 


52 

Jul 

74 

Aug 

80 

Aug 

52 

Sep 

HAM  HELP 


Help!!l  1  am  having  difficulty 
In  locating  a  schematic  or  oper* 
ating  manual  for  the  following 
piece  of  equipment.  It  looks  like 
a  modem  but  1  want  to  be  sure.  It 
has  a  transmit  and  receive  sec^ 
tion.  The  model  number  on  the 
receive  section  ps  ICRCU-RS-I. 
The  model  number  on  the  trans- 
mtt  section  is  1CTCU-RS-1.  It 
carries  the  Burroughs  Trade- 
mark on  the  case  but  It  was 
manufactured  by  Stefma.  Inc. 
Burroughs  and  Stelma.  Inc., 
have  not  been  able  to  help.  Any 
Information  would  be  greatly  ap- 
preciated. 

Terry  Hazelett 

21 07  Capitol  Dr, 

Parkersburg  WV  26101 

I  need  a  schematic  and/or  In- 
struction manual  for  a  Collins 
310B-1  exciter.  I  will  buy  a  copy 
or  reproduce  one  and  return  It.  I 
also  need  an  ac  power  supply 


for  a  KWM-2A. 

Herman  F.  Shnur  K4CTG 

115  Intercept  Ave, 

North  Charleston  SO  29405 

I  would  like  to  correspond 
with  people  who  have  working 
models  of  com puter-contro tied 
or  radio-controHed  humanoid  ro- 
tJOts.  Thank  you. 

Matt  Beha  N8BPI 

3752  Lane  Court 

St  Joseph  Ml  49085 

Our  school  amateur  radio 
club  is  in  need  of  the  schematic 
and/or  instructions  for  a  Ham- 
marlund  four-20  transmitter. 
Payment  for  copies  will  be 
mailed  or  we  will  copy  and  send 
back  if  preferred. 

Barringer  High  School 

c/o  F.  Rice  N2BVZ 

90  Parker  Street 

Newark  NJ  07105 


73  Magazine  •  December,  1980    179 


FUN! 


from  page  26 

17)    Stow-scan  television  Is  permitted  on(y  on 

upper-sideband. 
16)    Hertz  rotation  is  an  importarit  factor  in 

moonbounce  communication. 

19)  Amplitude-shift  radtotelelype  is  also 
called  '*make-and'bfeak"  keying. 

20)  Color  amateur  television  is  permitted  on- 
ly atK>ve  1296  MHz. 


ELEMENT  4— SCRAMBLED  WOflDS 

Uosc ramble  tliese  words  deal ing  with  speciaHzed  mode  activities. 


rswohe 

hpcun 

craos 

cibsa 

trenrip 

ivode 

anocbe 

puknfl 

tebl 

olop 

ormci 

xfa 

rliadgt 

lupes 

cnsy 

eramac 

rtc 

nisp 

retmoe 

nigp 

ELEMENT  5- HAMAZE 

Here's  a  new  type  of  maze  specifically  geared  to  hams.  The  object 
is  to  start  at  the  circle  and  trace  your  way  to  the  square  by  filling  in 
the  answers  to  the  clues  given  below.  To  help  you  on  the  way,  we've 
already  given  you  the  Hrst  and  last  clue  answers.  AH  words  read 
either  vertically  downward  or  from  left  to  right  Each  new  word  is  on 
aperpencf/cu/arangleto  the  previous  word.  Words  join  on  a  common 
letter.  Good  luck. 


IJ    Mark  and  space  (given) 
^     RTTY  automatic  monitor- 
ing 

3)  Phase  111  computer  chan- 
nel (abbr.) 

4)  Take  antenna  for  a  turn 

5)  Meteor  and  rain 


6)  Without  pattern  or  a  mem- 
ory 

7)  Betweer^  short  and  long 
waves 

8)  Frequency  above  1  GHz 

9)  Moonbouncer's  reply 
10)    Thousand  prefix 


11)  You  type  on  one 

12)  CRT,  digital,  etc. 

13)  TV  scale 

14)  Satellite  protection  band 
16)  WAS,  DXCC.  etc. 

16J  People  who  sank  Phase  I 
(abbr.) 


17)  Greek;  at  a  distance 

1 8)  RTTY  error 

19)  Highest  point  or  radio 
company 

20)  OSCAR  rotator; -el 

21)  Skyhook:  an (given) 


THE  ANSWERS 

Etement  1: 
See  illustration. 

Element  2: 

1  L  2-D,  3-E,  4-K,  5-C,  6-H»  7-G,  8^A,  W,  10-R 

Element  3: 

1)True  -  Yes.  but  now  there  are  many  other  funny  noises  to  be  heaitl 

on  this  band. 

2)  True  -With  Charles  Krum  he  formed  the  Morkrum  Company  which 
was  eventually  bought  out  by  AT&T.  He  got  to  keep  the  salt  busi- 
ness, however. 

3)  False-  No,  F1  is.  Theonty  FCC  designation  AF2M  has  is  his  Extra 
ticket. 

4)  True  *  Uke  clockwork. 

5)  False  -  Only  RTTY. 

6)  True  -  Many  times. 

7)  True  -  With  a  little  on  50  MHz  and  some  activity  at>ove  432. 

8)  True  "  WB21BE  to  K70FT,  November  20. 1979,  on  50  MHz. 

9)  True  -  Still  not  quite  television  in  the  conventional  sense,  but  an 
improvement  beyond  slow  scan. 

10)  True  -  Write  to  Washington  stating  your  reason. 

1 1)  False  -  Most  awards  require  a  real  signature  on  them  for  credit. 

12)  False  -  That^s  really  wideband!  Kill  the  *'k." 

13)  False  -  No,  it  stands  for  Narrow  Band  Voice  Modutation.  The 
meter,  however,  vwouid  probably  be  more  useful. 

14)  False  -  Eighty  and  up. 

15>  False  -  All  GW  bands  but  Novice  and  160. 

16)  False  -  Means  ''Earth-Moon-Earth." 

17)  False  -  Only  by  convention  on  20  and  up, 

18)  False  -  The  polarization  change  of  a  signal  passing  through  the 
Earth's  ionosphere  is  known  as  Faraday  rotation. 

19)  True  -  Old  practice  that  was  eliminated  when  FCC  approved  fre- 
quency-shift keying. 

20)  False  -  Color  television,  fast  scan  or  slow  scan,  is  allowed  on  any 
appropriate  amateur  TV  frequency. 

Element  4: 

(Reading  from  left  to  right)  shower,  punch,  oscar,  basic:  printer, 
video,  beacon,  uplink;  bell,  loop,  micro,  fax;  digital,  pulse,  sync, 
camera;  crt*  spin,  meteor,  ping. 

Element  5: 
See  illustration. 


SCORING 

Element  1: 

See  illustration.  Twenty  points  for  the  complete  puzzle,  or  1/2  point 

for  each  question  you  got. 

Element  2: 

Two  points  for  each  mode  yoo  matched  to  its  equipment. 

Element  3: 

One  point  for  each  correct  answer. 

Element  4: 

One  point  for  each  word  successfully  unscrambled. 

Element  5: 

Twenty  points  for  complete  puzzle,  Of  one  point  for  each  word. 


180    73MBgazine  •  December,  1980 


Total  up  your  points  and  see  the  fevef  of  your  technical  expertise: 

0-20  points  -  Lid 
21-40  points  -  Physically-fit  Conditional 
41-60  points  -  KA 
61  -80  points  -  A  pro 
81  and  up  -  A  Technician  in  tlUe  fulf  sense  of  the  term 


R 

A 

M 

1 

T 

E 

L 

E 

T 

Y 

P 

E 

0 

p' 

S 

D 

0 

X  H 

p  ^1 

R 

R 

G 

^M    E 

^1    D 

^1  H 

A 

G 

E 

Q 
U 

1 
P 

X 

N 

P 

E 

R 

1 

M 

E 

N 

T 

^^1 

E^l 

C 

A 

R 

1-    > 

T 

Y 

A 

P 

R 

T 

^ 

L 

F 

0 

1 

K 

E 

S 

R 

1 

R 

S 

^^H 

1 

A 

G 

C 

P 

Y 

■ 

M 

0, 

N 

1 

T 

0 

R 

1 

U 

V 

1 

S 

T 

E 
N 

T 

M 

E 

V 

T 

A 

R 

S 

^ 

A 

V 

W 

R 

■ 

A 

P 

1 

F 

A 

C 

s 

1 

M 

I 

L 

E 

Next  month:  Ham  History 


REVIEW 


RADiO  EQUtPMENT 
ANO  SUPPLIES 

It's  been  estimated  that  there 
are  at  least  8,000  collectors  and 
enthusiasts  of  antique  radio 
equipment  in  the  United  States. 
As  is  the  case  with  all  manner  of 
antiquities,  there's  a  great  de- 
mand for  literature  on  these  old 
sets  and  the  equipment  that 
was  used  three  generations 
back,  when  radio  began  to  make 
itseff  1<nown  to  the  public. 

Radio  Equipment  and  Sup- 
pties  is  3  ISO-page  catalog  orrgK 
nally  issued  in  1922  by  the  Rob- 
ertson^Cataract  Company  of 
Buffalo,  New  Vork.  a  major  dis- 
tributor in  the  field.  It's  full  of 
pictures  of  receivers,  transmit- 
tefs^  tubes,  vario-couplers,  tun- 
ing inductances,  headphones, 
and  all  the  apparatus  that  radio 
people  of  that  day  had  to  grap- 
ple with  in  order  to  ''bring  in  the 
stations''  or  to  ''get  on  the  air" 

To  serve  the  interests  of  the 
antique  radio  buffs  of  today.  The 
Vestal  Press  has  made  a  top- 


quality  reprint  of  this  8Vz^'  x  1  r' 
book.  With  its  contents  includ- 
ing 30  pages  of  receivers,  74 
pages  of  accessories  for  receiv- 
ers, 30  pages  on  transmitting 
equipment,  and  20  pages  of  ba- 
sic *'Radio  Inlormation  and 
Data/'  there's  something  for  ev- 
ery one  of  the  present-day  en- 
thusiasts. It  contains  literally 
hundreds  of  photographs  and 
drawings,  and  the  1922  prices 
would  make  anyone  weep*  It's 
certainly  Interesting,  in  the  light 
of  today's  highly  sophisticated 
electronics,  to  view  the  astound- 
ing changes  that  have  occurred 
in  the  past  60  years. 

Copies  are  available  directly 
from  The  Vesta i  Press  Ltd.,  Box 
97,  Vestal  NY  13850,  or  through 
any  bookstore,  for  $12.50  +  754; 
shipping  {NY  residents  add 
sales  tax), 

CODING  AND  DECODING 

TELEVISION  SIGNALS 

Science  Workshop 

Everyone   is  talking   about 


"those  secret  TV  channels."  If 
you  have  a  fistful  of  money  or  a 
lot  of  technical  expertise,  you 
might  build  an  earth  satellite  ter* 
minal.  For  a  bit  less  cash  an 
MDS  microwave  receiver  capa- 
ble of  catching  iocaf  pay  TV  sig- 
nals can  be  had.  A  third  source 
of  limited  access  viewing  is 
signals  transmitted  on  convene 
tional  UHF  TV  channels  but 
scrambled  at  least  part  of  the 
time.  As  nonpaying  "custom- 
ers" become  prevalent,  more 
and  more  of  these  common  car- 
rier video  signals  will  be  encod- 
ed  and,  of  course,  more  than  a 
few  hams  will  be  busy  trying  to 
unscramble  them.  Now,  much  of 
the  current  scrambling  tech- 
nology is  discussed  in  Science 
Workshop*s  book,  Coding  and 
Decoding  Tefeviston  Signals. 

A  video  freak  is  likely  to  ex* 
claim.  **So  that^s  how  they  do 
itf"  after  reading  Coding  and  De- 
coding for  the  first  time.  Materi- 
al for  this  book  was  gathered 
from  a  variety  of  public  and  pri- 
vate sources.  Included  in  the 
contents  is  a  word-for-word  re- 
production of  a  NASA  report  on 
the  scrambling  technique  used 
for  the  Application  Technology 
Satellite  video  signals.  Later 
sections  explain  how  some  UHF 
signals   are   encoded   with   a 


t5-kHz  pulse  train  and  have 
special  subcarrier  audio.  Block 
diagrams,  oscillographs,  and 
spectrum  analyzer  photographs 
supplement  the  descriptive  text, 

The  editor  of  Coding  ^nd  De- 
coding Teievlsion  Signafs 
states,  'This  is  not  a  'how^to' 
book.  It  does  not  contain  any 
construction  projects/'  How- 
ever, an  amateur  knowledgeable 
about  video  and  experienced  in 
building  rf  circuits  should  be 
able  to  successfylly  reproduce 
the  designs  shown.  You'll  have 
to  make  your  own  parts  lists  and 
circuit  board  templates,  though. 

For  some  reason,  beating  the 
system  at  its  own  game  has  al- 
ways been  an  attraction  for  elec- 
tronics experimenters.  As  the  is- 
sue of  the  freedom  of  the  air- 
ways is  discussed  in  high 
places*  hundreds  or  even  thou* 
sands  of  tinkerers  witi  be  using 
information  from  books  like 
Coding  and  Decoding  Television 
Signafs  to  build  their  own  units. 
Costing  $9.95  (SI. 00  postage), 
this  43-page  softcover  pay-TV 
primer  for  experimenters  js 
available  from  Science  Work- 
shop, Box  393,  Beth  page  NY 
11714. 

Tim  Daniel  N8RK 
73  Magazine  Staff 


73  Magazine  •  December,  T980     101 


DX 


from  page  14 

point  of  view  on  the  subject,  but 
there  should  be  no  doubt  just 
what  its  point  of  view  is. 

FOR  SALE:  QSLS 

As  Song  as  we  are  rampaging, 
might  as  weii  take  up  one  addi- 
tional subject  recently  beaten 
nearly  to  death  in  the  amateur 
press.  Maybe  we  can  breathe  a 
little  life  into  it.  Some  have  com- 
plained about  the  practice  of  re- 
quirrng  payment  of  a  dollar  for  a 
QSL  for  an  expedition  contact. 
Actually,  this  is  not  new. 
W9WNV  (and  others)  were  doing 
it  fifteen  or  more  years  ago,  only 
then  you  paid  for  the  contact  be- 
fore the  expedition  was  un- 
dertaken. Those  who  anted  up 
found  that  the  DXpeditioner  was 
able  to  hear  them  without  dif- 
ficulty; those  who  held  out  were 
just  not  heard  or  worked. 

Grousing  when  required  to 
supply  a  buck  for  a  QSL  shows 
little  appreciation  for  the  sacri- 
fices made  by  expeditioners. 
When  they  moan  in  print  about 
it,  that  constitutes  almost  a  per- 
sonal  affront  to  the  DXer  who 
has  made  it  possible  for  many  to 
work  a  new  country.  As  plane 
tickets  are  not  free,  we  see  little 
wrong  with  QSLing  on/y  to  those 
who  help  with  the  expenses. 
Most  expeditioners  are  not  mde- 
pendently  wealthy  and  are  only 


practicing  economic  horse 
sense.  If  they  recoup  some  of 
the  expenses  from  one  trip,  they 
are  more  likely  to  make  another, 

ISTANBUL  REPORT 

The  accompanying  letter 
from  an  amateur  In  Turkey  is 
printed  in  full^  except  that  all 
references  to  callsigns  and 
names  have  been  deleted.  Any- 
one wishing  to  act  as  QSL  man- 
ager for  the  writer  of  the  letter 
can  make  arrangements  by  writ- 
ing to  me  at  the  address  given  at 
the  beginning  of  this  column. 

'Istanbul,  Aug.  26,  1980 

Dear  OMs;  1  am  a  subscriber 
to  73,  and  I  am  very  glad  to  see  a 
DX  column  in  your  excel ient 
magazine.  The  purpose  of  my 
letter  is  to  provide  you  with 
some  materiai  and  information 
for  the  section,  and  possibly 
seek  your  help  on  a  subject. 

Here  in  Turkey,  for  a  long  time 
there  has  been  on-andoff  oper^ 
ating  by  courageous  local  and 
by  temporarily  resident  foreign- 
ers (mainly  from  the  US).  I  am 
sure  some  of  your  fellow  hams 
and  subscribers  do  not  know 
that  ham  radio  in  Turkey  is  still 
illegal  due  to  a  law  dated  1937!  I 
say  TA  is  activated  by  courage- 
ous people  because  possession 
and  operation  of  transmitters 
has  severe  penalties,  including 
imprisonment    of    up   to   five 


years  1 

'Terrorism  all  over  the  world 
Is  well  known,  and  we  too  have  a 
fair  share  of  it  in  TA  Land.  I  am 
sure  there  would  be  far  less  of  it 
if  we  had  worthwhile  hobbies 
like  amateur  radio  to  keep  the 
young  people  occupied.  We 
have  martial  law  in  certain  parts 
of  the  country  (including  Istan- 
bul), during  which  the  penally 
for  the  above  mentioned  offense 
is  ten  years  in  jail!  Big  risks  are 
tai^en  in  operating,  but  you  know 
ham  radio  is  a  bug  and . .  , 

''Therefore,  operation  from 
TA  is  sporadic;  at  present  we 
must  be  at  an  all-time  low.  I  have 
been  QRT  since  March,  1980, 
and  will  be  so  for  another  few 
months. 

''We  have  an  amateur  radio 
club,  TRAC,  which  is  listed  in  the 
Calibook  for  incoming  QSLs. 
That  is  the  only  service  provided 
by  TRAC  except  for  a  magazine 
which  gets  published  now  and 
then.  Since  there  is  no  outgoing 
QSL  service,  I  suspect  the  QSL 
record  of  TA  stations  is  not  very 
good,  as  everyone  is  on  his  own 
for  sending  cards.  Having  a 
100%  QSLing  record  is  very  im- 
portant to  me. 

"One  question  which  is  often 
asked  is  how  and  by  whom  we 
get  our  calls  assigned.  The  an- 
swer is  that  we  do  not  get  them 
assigned,  we  just  pick  them  our- 
selves. The  country  was  divided 
into  call  areas  by  the  club  when 
it  was  founded  in  the  1960s. 
Most  of  us  pick  ouf  initials  and 
we  all  know  each  other  so  dupli- 
cates are  prevented.  We  watch 
out  for  newcomers,  too. 

"As  far  as  equipment  is  con- 


cerned, it  simply  Is  not  available. 
Transmitters  and  transceivers 
are  illegal,  and  even  receivers 
are  almost  nonexistent.  I  per- 
sonally would  be  willing  to  pay 
twice  the  iist  price  for  a  good 
receiver.  We  make  do  with  what- 
ever we  can  find  in  surplus,  and 
that,  too,  is  something  which 
may  come  once  in  a  lifetime. 
Surplus  and  simple  homemade 
rigs  are  what  you  hear  from 
Turkey.  If  our  signals  are  drifting 
and  we  cannot  hear  you  S9,  I 
think  we  can  be  excused  if  peo- 
ple know  the  conditions  we  work 
in. 

"Attempts  have  been  made  to 
change  the  1937  law  but  have 
failed  for  various  reasons,  main- 
ly because  the  people  con- 
cerned did  not  know  what 
amateur  radio  was  about.  Late- 
ly, the  final  word  has  been  that 
to  ensure  the  national  security, 
monitoring  stations  tied  to  a 
computer  center  where  'exact 
location  of  any  transmission 
can  be  found'  is  the  only  way  for 
amateur  radio  to  be  legal  in 
Turkey.  Estimated  cost  of  this  is 
twenty  mlllron  dollars! 

''I  hope  73  can  find  a  manager 
for  my  QSLs  when  I  return  to  the 
air.  I  am  sure  you  have  a  heavy 
workload,  so  if  you  cannot  spare 
the  time  I  shall  understand. 

73, 
TA2 /' 

This  is  a  somewhat  abbreviat- 
ed  column  due  to  things  backing 
up  at  the  editor's  shop.  The  col- 
umn will  be  back  to  its  usual  size 
in  January.  Your  input  of  letters 
and  pictures  is  appreciated. 


comsTs 


from  page  16 

couver,  BC  Canada  V6J  1E3, 
postmarked  before  January 
15th.  Results  will  be  published 
in  TCA^  the  Canadian  amateur 
magazine.  Non-subscribers  may 
include  an  SASE  for  a  copy  of 
the  results. 


ZERO  DISTRICT  QSO  PARTY 

Starts:  20Q0  GMT  January  3 

Ends:  0200  QMT  January  5 

Organized  by  the  Mississippi 
Valley  Radio  Club.  Stations  out- 


side  of  Zero  District  will  work 
Zero  stations  only;  Zeros  may 
work  any  station.  The  same  sta- 
tion may  be  worked  once  on 
each  band  and  each  mode.  How- 
ever, stations  in  the  special 
mobile  class  may  be  worked 
each  time  they  change  counties. 

EXCHANGE: 

RS(T)  and  ARRL  section.  Zero 
Dtstrict  stations  also  must  send 
county, 

FREQUENCIES: 

3560,  7060,  14060,  21060, 
28060,  3900,  7270,  14300,  21370, 


28570,  3725,  7125,  21125,  28125- 

SCORiNG: 

Add  the  number  of  Zero  Dis- 
trict ARRL  sections  worked  plus 
the  number  of  Zero  Dtstrict 
counties,  then  multiply  by  the 
number  of  contacts.  Zeros  score 
by  adding  ARRL  sections,  Zero 
District  counties,  and  DXCC 
countries  worked,  and  then  mul- 
tiplying by  total  contacts. 

ENTRIES  &  AWARDS: 

Awards  will  be  issued  to  the 
high  scorer  in  each  ARRL  sec- 
tion and  DXCC  country.  Also  to 
top  Novice/Technician  and  top 
in  special  mobile  class-  Mail 
logs  by  February  15th  to:  W<3SI, 
3518  W.  Columbia,  Davenport  lA 
52804.  Include  an  SASE  for  log 
forms  or  results. 


2nd  ANNUAL  INTERNATIONAL 

160-METER  PHONE  CONTEST 

Sponsored  by  73  Magazine 

Starts:  0000  GMT  January  17 

Ends:  24D0  GMT  January  18 

This  is  the  second  annual 
160-meter  contest  sponsored  by 
our  magazine.  The  object  Is  to 
work  as  many  stations  as  possi- 
ble on  160-meter  phone  in  a 
maximum  of  30  hours  allowable 
contest  time.  Multi-operator  sta- 
tions may  operate  the  entire 
48-hour  contest  period.  Entry 
categories  include  single-  and 
multi-operator,  both  with  single 
transmitter  on  phone  onfy, 

EXCHANGE: 

Stations  within  the  Continen- 
tal USA  and  Canada  transmit  RS 
report  and  state  or  province.  A  I! 
others  transmit  RS  report  and 


182     73  Magazine  •  December,  1980 


DX  country. 

SCORING: 

All  valid  two-way  contacts 
score  5  points  per  OSO,  A  sta- 
tion may  be  worked  only  once 
for  contest  credit!  Multipllefs 
are  as  follows'  1  multiplier  point 
for  each  of  the  Continental  US 
states  (48  nr^ax.);  1  multiplier 
point  for  each  of  the  Canadian 
provinces  (13  max.^;  3  multiplier 
points  for  each  DX  country  out- 
side the  Continental  US  and 
Canada. 

The  final  score  is  the  total 
QSO  points  times  the  total  mul- 
tiplier points. 

DX  WINDOW: 

Stations  are  expected  to  ot> 
serve  the  DX  window  from  1.825 
to  1.830  MHz  as  mutually  agreed 
by  Top  Band  operators.  Stations 
m  the  US  and  Canada  are  asked 
not  to  transmit  in  this  5*kHz  seg- 
ment of  the  band. 

AWARDS: 

Contest  awards  will  be  issued 
in  each  award  category  in  each 
of  the  Continental  US  states, 
each  Canadian   province,  and 


each  DX  country. 

DlSOUAUFfCATIONS: 

Disqualiffcations  may  result 
if  contestant  omits  any  required 
entry  forms,  operates  in  excess 
of  iegaf  power  authorized  for  his 
given  area,  manipulates  operat* 
ing  times  to  achieve  a  score  ad- 
vantage, or  fails  to  omit  dupli- 
cate contacts  which  reduce  the 
overall  score  more  than  2%. 

ENTRIES: 

Each  entry  must  include  I09 
sheet*  dupe  sheet  for  100  or 
more  contacts,  a  contest  sum- 
mary sheet,  and  a  multiplier 
checKlisl  All  entries  must  be 
postmarked  no  later  than  Feb- 
ruary 21st.  To  request  contest 
forms  Of  submit  your  entry, 
wfite:  Dan  Murphy  WA2GZB,  PO 
Sox  195,  Andover  NJ  07821  USA. 
Please  include  an  SASEI 

SPECIAL  CHRISTMAS 
EXPEDITIONS 

With  the  Christmas  holidays 
fast  upon  us,  there  are  two  spe* 
cial  operations  planned  for  the 
holidays.  The  Delaware-Lehigh 
Amateuf  Radio  Club  (W30K)  will 


have  a  special  events  station  on 
the  air  as  part  of  Bethlehem 
PA'S  Christmas  CHy  Celebra- 
tion, The  station  will  be  on  the 
air  from  2300  to  0300  GMT  start- 
ing December  15th  and  will  con- 
tinue to  operate  through  Janu- 
ary 1st.  The  operating  hours  will 
increase  during  the  period 
whenever  possible.  Operation 
will  be  on  the  Novice  CW  and 
Generaf  phone  bands.  Suggest- 
ed frequencies  are:  ISkHzdown 
from  the  top  of  the  Novice  band, 
and  15  kH^  up  from  the  bottom 
of  the  General  phone  band.  Spe- 
cial QSO  certificates  will  be  sent 
from  the  Christmas  City  Station. 
QSLs  or  requests  should  be 
mailed  with  a  business-size 
SASE  to:  W30K,  DLARC.  1719 
Gal  lone  Avenue.  Bethlehem  PA 
1 B01 7,  SWL  requests  will  also  be 
honored. 

The  Indian  River  Amateur  Ra- 
dio Club  of  Cocoa  FL  will  t>e  op* 
erating  from  Christmas  FL  from 
December  20  through  27.  Oper- 
ating times  will  genefally  be 
from  1400  to  2000  GMT  daily. 
The  town  of  Christmas,  located 


on  the  east  coast  of  Florida,  wel* 
comes  many  visitors  each  year 
from  around  the  USA.  Christmas 
is  celebrated  each  and  every 
day  of  the  year.  There  are 
fully  lighted  Christmas  trees, 
wreaths,  and  decorations  along 
with  Santa  and  his  helpers.  The 
Indian  River  Amateur  Radio 
Ciub.  as  a  celebration  of  its  26th 
yearof  organization,  will  use  the 
club  callsign  W4NLX/4.  A  spe- 
cial handsome  certificate  will  be 
awarded  to  all  worked  stations. 
This  certificate  depicts  some  of 
the  aspects  of  Christmas  in 
Florida.  Arrangements  have 
been  made  to  have  a  si>ecial 
cancellation  at  the  US  Post  Of- 
fice for  this  award-  Please  send 
a  large  SASE  for  the  certificate. 
Operating  frequencies  on  SSB 
will  be  7280,  14280,  21380,  and 
28680.  On  CW,  the  club  will  oper- 
ate 60  kHz  up  from  the  bottom 
edge  of  the  40-,  20-,  15-,  and 
10-meler  bands.  The  146.34/.94 
repeater  will  also  be  operational 
for  local  contacts.  QSL  to  Indian 
River  Amateur  Radio  Club, 
W4NLX,  PO  Box  106,  Christmas 
FL  32709. 


AWARDS 


from  page  20 

bands  the  same  day  (6x3  = 
18)  or  work  him  on  twenty  me- 
ters three  individual  days  (6x3 
:^  18),  you  wiil  have  qualified 
very  easily  for  the  Gold  Sardin- 
ian Award.  Sounds  easy,  doesn't 
it? 

To  be  valid,,  all  signal  reports 
must  be  a  minimum  of  338  for 
CW  and  43  Tor  phone. 

To  apply,  have  your  claimed 
contacts  verified  by  at  least  two 
amateurs  or  a  local  radio  club 
officlaL  Enclose  your  appllca- 
tron  with  an  award  fee  of  15  IRCs 
or  $4.00  US  to:  URS  Club,  via  Sar 
degna  1 6. 07100  Sassari,  Sardin- 
ia. 

While  in  Europe,  let's  visit  the 
United  Kingdom,  where  last 
time  I  failed  to  include  two  very 
interesting  awards, 

HAMPSHIRE  COUNTY  AWARD 

The    Hampshire    County 

Award  is  made  available  to  ama- 
teurs worldwide  who  have  es- 
tablished two-way  contact  with 


amateur  operators  of  Hamp- 
shire County  in  England,  The 
award  Is  issued  on  a  point  basis 
in  which  all  contacts  count  1 
point,  with  the  exception  that 
contacts  with  G3BZU,  GB3RN, 
or  any  other  special-event  sta- 
tion count  2  points. 

There  are  three  award  classes: 
Class  I -UK/50  points:  EU/20 
points:  DX/15  points.  Class  II- 
UK/30  points;  ELI/15  points; 
DX/10  points.  Class  \\\^UKi20 
points:  EU/10  points:  DX/5 
points. 

To  ba  valid,  alt  contacts  must 
be  made  after  October  1,  1960, 
There  is  no  mode  or  band  re- 
striction, but  special  band  or 
mode  recognition  will  be  made  if 
requested  at  the  time  of  applica- 
tion. 

To  apply,  have  your  list  of 
claimed  contacts  verified  by  at 
least  I  wo  amateurs  or  a  local  ra- 
dio club  official.  Forward  this 
application  and  an  award  fee  of 
50  pence  or  6  IRCs  to:  F.  D< 
Cawley  G2GM,  Award  Manager, 
Bay  Sound,    Freshwater   Bay, 


Freshwater,  Isle  of  Wight.  En^ 
giand,  United  Kingdom, 

THE  MERCURY  AWARD 

While  In  England,  it  is  my 
honor  to  feature  to  our  readers 
the  very  respectable  Mercury 
Award,  sponsored  by  the  Royal 
Naval  Amateur  Radio  Society. 
This  award  was  initiated  to  en- 
courage contact  with  the  many 
members  of  the  Royal  Naval  So- 
ciety. Ttie  award  is  issued  to  any 
amateur  who  can  meet  the  re- 
quirements of  the  program 
which  are  tabulated  on  a  point 
basis.  Contacts  with  RNARS 
members  on  the  HF  bands  earn 
1  point  each,  while  two-way  con- 
tacts established  30  y\Hz  and 
above  constitute  2  points 
apiece.  In  addition,  any  special- 
event  station,  such  as  GB3RN  or 
63BZU,  counts  double  the  nor- 
mal point  value. 

To  attain  the  award,  stations 
within  the  United  Kingdom  must 
accumulate  a  total  of  20  points, 
other  European  stations  must 
total  a  minimum  of  10  points, 
and  stations  outside  Europe 
must  gather  a  total  of  at  least  5 
points.  Once  an  applicant  earns 
10  pomts  (for  US)  or  20  points 
(for  Europeans),  stickers  will  be 
issued  for  each  multiple  of  10 
points  earned  thereafter. 

Contact  must  be  made  Octo- 


ber 1 ,  1960,  and  after  to  be  valid. 
There  are  no  band  or  mode  re- 
strictions, but  recognition  will 
be  given  if  special  band  or  mode 
accomplishments  are  attained. 

The  fVlercury  Award  also  is 
made  available  to  shortwave 
listeners  who  must  meet  the 
same  criteria  on  a  "heafd-only" 
basis. 

Do  not  send  QSLs!  Have  your 
list  of  claimed  contacts  verified 
by  at  least  two  fellow  amateurs 
or  a  radio  club  official.  Enclose 
this  application  along  with  the 
award  fee  of  6  IRCs  to:  Awards 
Manager  G3HZU  153  Worple 
Road,  Isleworth,  Middlesex  TW7 
7HT,  England,  United  Kingdom. 

To  be  successful  in  confirm* 
ing  contacts  with  members  of 
the  Royal  Naval  Amateur  Radio 
Society,  it  is  advisable  that  you 
obtain  a  list  of  their  members 
before  attempting  the  challenge 
of  this  award.  It  is  unfortunate 
that  the  list  is  so  lengthy,  as 
space  does  not  permit  the  list  to 
be  printed  at  this  time.  As  an  al- 
ternative, however,  the  Mercury 
Award  is  featured  in  the  OX 
Awards  Guide  published  by 
Chuck  Ellis  WOYBV.  The  entire 
list  of  RNARS  meml3€rs  is  con- 
tained within  this  publication. 
This  DXer's  award  guide,  fea^ 


73  Magazine  •  December,  1980     183 


tyred  In  last  month's  column  In 
detail,  Is  available  for  a  very 
modest  price  of  $1 4.95  (plus  1-!b. 
postage  for  DX  shipment)  by 
enciosing  payment  to  Chuck 
Efiis,  PO  Box  1136  Welch  Sta- 
tion. Ames  lA  50010.  Be  sure,  if 
thai  15  the  reference  you  ptan  to 
use,  that  you  tell  Chuck  you  read 
about  it  here  in  the  73 Magaime 
Awards  column. 

If  you  are  like  many  of  us  on 
the  west  coast  and  are  looking 


for  a  real  toughie,  try  your  hand 
at  working  toward  the  Worked 
All  Gozo  Award. 

WORKED  ALL  GOZO  AWARO 

The  WAG  Award,  as  it  is 
called,  is  open  to  amateurs  and 
SWL  stations  and  has  no  band 
or  mode  restrictions.  To  be  valid, 
all  contacts  for  this  award  must 
be  made  on  or  after  August  1, 
1972. 

To  qualify,  European  stations 


must  confirm  8  individuaT  sta- 
tions from  Gozo  Island  (9H4). 
Now,  if  you  are  considered  a  DX 
station  tike  we  are  in  the  USA, 
you  only  have  to  work  5  different 
Gozo  Island  stations.  And,  of 
course,  if  you  are  like  me,  you'il 
be  happy  to  settle  for  just  an 
SWL  Heard  Only  Award  which 
also  is  available  under  the  same 
requirements. 

Do   not   send   QSL   cards. 
please!    Have    your    list    of 


claimed  Gozo  Island  contacts 
verified  by  at  least  two  amateurs 
or  a  radio  club  official.  Forward 
this  verified  application  and  an 
award  fee  of  $3.00  or  12  IRCs  to; 
Joe  CauchI  9H4L.  20  P.  P.  Hili 
Street,  Victoria,  Gozo  Island* 
Malta.  Alt  award  fees  are  con- 
tributed to  aid  the  blind  and 
handicapped  operators:  we  all 
should  apply  for  this  award  if  for 
no  other  reason  than  to  aid  this 
cause. 


OUR  AWARDS  PROGRAM 

By  the  time  this  magazine  reaches  your  hands,  the  hun- 
dreds of  certificates  already  earned  via  the  73  Awards  Pro- 
gram will  be  on  their  way  to  amateurs  around  the  world. 
Now,  if  you  are  one  of  the  many  who  qualified  for  an  award 
months  and  months  ago,  you're  no  doubt  saying,  "It's  about 
time!"  Right  you  are. 

What  caused  the  incredible  delays?  First  of  all,  some  of 
us  underestimated  the  work  Involved  in  getting  the  certifi- 
cates designed  and  produced.  But  more  than  Ihat,  we  too 
often  allowed  the  Awards  Program  to  take  a  back  seal  to 
other  profects  which,  at  the  time,  seemed  more  important* 
Few  of  us  at  73  wear  only  one  hat,  and  it  was  all  too  easy  to 
stop  working  on  the  awards  when  article  titles  needed  to  be 
written  or  when  manuscripts  needed  to  be  read.  After  all,  we 
had  magazine  deadlines  to  meet  each  and  every  month,  and 
ft  always  seemed  that  the  awards  could  wait . . .  and  wait . . , 
and  wait.  In  short,  we  blew  it. 

In  retrospect,  it's  easy  to  see  what  we  should  have  done. 
For  starters,  we  should  have  had  the  awards  printed  and  on 
the  shelf  before  the  Awards  Program  was  even  announced. 
Then,  we  should  have  assigned  one  person  to  stay  on  top  of 
the  program  and  keep  it  moving.  The  good  news  is  that  we 
have,  at  last,  recognized  these  failings,  and  the  Awards  Pro- 


gram is  (inaily  up  to  speed.  The  debacle  of  the  past  14 
months  is  over,  and  the  awards  are  going  out. 

Before  proceeding  any  further,  a  note  of  commendation  is 
in  order.  The  man  who  writes  this  column  each  month  and 
serves  as  manager  of  our  Awards  Program  is  Bill  Gosney 
WB7BFK.  Bill  has  been  with  the  program  from  the  begin- 
ning, and  he  has  done  an  outstanding  Job  under  very  diffi- 
cult circumstances-  He's  done  everything  we  have  asked  of 
him  and  more.  If  you;  ve  been  waiting  for  an  award,  the  delay 
was  at  our  end,  not  his.  Thank  you,  Bill 

To  those  of  you  who  have  earned  awards  through  our  pro- 
gram goes  a  special  note  of  thanks  for  getting  involved  in 
our  new  and  untried  venture.  Now  that  weVe  back  on  track, 
we  hope  you  enjoy  your  awards  and  that  youll  apply  for 
others  in  the  future.  If  you  have  never  applied  for  a  73  award, 
please  do  so;  the  system  is  working,  and  it*s  our  goal  lo  han- 
dle all  future  applications  quickly  and  efficiently. 

As  we  move  into  the  third  decade  of  73  Magazine,  weVe 
tookmg  forward,  not  back.  There  are  exciting  times  ahead 
for  amateur  radio,  and  we  want  the  73  Awards  Program  to  be 
a  part  of  it. 

Jeff  DeTray  WB&BTH 
Assistant  PublisheriEditor 


73  AWARD  WINNERS 


NORTH  AMERICAN 
CONTINENT  AWARD 


1 

WA2QUM 

2  WetVf'A 

3 

K4HH0 

4 

KE4E 

s 

N6TK 

6 

AASTK 

7 

WA1SM1 

a 

WA9BBX 

»  tCiZlF 

10  WBfYMfl 

11 

waaWL^ 

12 

WB3BAP 

13 

WDIIiOO 

14 

WBTBFK 

15 

WfilOOC 

16 

»C4BQZ 

IT 

KfiSY 

IB  KA5CQJ 

19 

KITH 

3»  WTULC 

21 

WB3ICM 

n 

KflWD 

23  W9NAX 

24 

VE18VD 

2B 

WDSHRH 

26  WD41IVI0V 

2T 

KdPSN 

2» 

A01S 

29 

DA1MV 

SO 

weiuxM 

31 

KASACAI 

32 

werrxv 

33 

WS3CfW 

34  N6PV 
3a  F2YS/W2 

36  W8CHV 

37  AJfil 

M  WA2YEX 

39  SMSAKT 

40  AC30 

41  WA2SRiM 

42  K5TJ 

43  WDVEPE 

44  K4JY0 

45  N8AC 
4e  JH1VRQ 
4T  WB3BVL 
4d  WD4DVZ 

49  WtYBV 

50  WB2FFY 

51  WSTJO 

52  W06DZ0 

53  Ka4jA 

54  WB4SXK 

55  DJ2UU 
Se  WD4K^K 
Sr  KA2EA0 
5S  K9MD 
59  N7BZ 

GO  W20DA 

61  W02MVC 

62  K4BYK 

63  KB6JF 

64  WA^PIP 

65  KB20E 

66  r^SAOL 


67  WB7PK0 
ea  S6AAT 

69  HK4DUM 

70  W09AVa 

71  W0911C 

72  WtAGA 

73  WB3JUK 

74  WA2RVF 

75  KA2K 

76  PYBZLC 

77  lt4LQ 
7i  0A1UO 

78  IC60GS 
ao  DAIQR 
«1  W04JIU 
62  AG5X 
S3  K9BIL 
B4  N4aOD 

as  wAaiYF 

66  WD9HWY 

67  N4B0D 


66  A11Y 

69  WB5SND 

90  fi^Am 

91  W06QEO 

92  VE3JQT 

93  KA5CTZ 

94  WD60EL 

95  WB«COHI 

96  KBdLT 

97  NiGP 
96  AJ6I 

99  N4AK0 
100  K&QDB 

101  Na&jo 

f02  KSBLV 
103  0F92r 
t04  KB50U 

105  K6GAK 

106  N1BCV 

107  SeAAP 
106  W87FIUV 


SOUTH  AMERICAN 
CONTINENT  AWARD 


1 

2 
3 
4 
S 


WB6VPA 
KE4E 
N6TK 
AA6TK 

WAisyt 

6  VE1BVD 

7  WD6EE0 
6  WB«YMR 
9  WB6VVUQ 

10  Wa26AP 

11  WDdMGQ 


12  WS7BFK 

13  WB10QC 

14  K9JSY 

15  KA5C0J 

16  KITH 

17  W7U1C 
13  K6WD 

19  K4HRG 

20  WU9HRH 

21  WDSMOV 

m  APIS 


S3  WB9UM 

24  WB3ICM 

25  KA0ACM 

26  WBTTXY 

27  WB3CtW 
26  K3PSN 

29  F2YS/W2 

30  KEDP 

31  WA2SAM 

32  AJ6L 

33  WA2YEX 

34  AC30 
^  SMSAKT 

36  WDiEPE 

37  JH1VHQ 
J&  WS3BVL 

38  WD4DVZ 
m  W5TJQ 

41  WOaOiO 

42  Wa4SXX 

43  WD4KHK 

44  K^MD 

45  KB4JA 

46  N7BZ 

47  DJ2UU 
46  WBCHV 
40  K9TI 

50  W20DA 

51  WB2MVC 

52  KA2EA0 

53  K4BYK 

54  KB6JF 

55  KB2SE 

56  WA2P1P 

57  WB7PK0 
56  SeAAT 


59  DAIMV 
50  HK4DUM 

61  WD9(IC 

62  W«VBV 

63  WB3JUK 

64  W1AQA 

65  PY6ZLC 

66  KA2K 

67  WA2nVF 
66  K4LQ 

69  DA1U0 

70  N6AC 

71  icaoQs 

73  DAI  OR 

73  AGSX 

74  K9BIL 

75  N4BQD 

78  WA2LYF 
77  W09HWY 

76  WBSSMO 

79  KBfOE 

60  N9AM1 

61  WD8QE0 

62  VE3JGT 

63  KA5CTZ 

64  WDSDEl 

65  WB6C0M 

66  KB8LT 

67  NBQP 
66  N4AK0 
69  KB6DB 

90  NOBJQ 

91  K5BLV 

92  DF9ZP 

93  KBSOU 

94  H1BCV 


95  WB7BUV 

96  SaAAP 


97  WD4LYA 


Q'5  AWARD  OF  EXCELLENCE 


1  WBEZJL 

2  W060NV 

3  KA8HMR 

4  K8IU 

5  WSJQEP 

6  KA9FPG 

7  WL7ADX 
6  WT>S£HI 
9  KASDBN 

10  KA3COP 

11  KA3CGM 

12  W]>2AKK 

13  W06IDD 

14  SM2C0R 

15  K9T8B 

15  WD5ICQ/1 


17  KA4KJI 

16  N3ADF 

19  K6TMB 

20  W9CJG 

21  KA6IGM 

22  WD6NHN 

23  WB30SO 

24  KAiHTU 

25  KA6GXN 

26  KAdCDH 

27  KA1ESG 

28  WQ6QHN 

29  WD4Bm 

30  KA3ENQ 

31  KA4J0S 


Sf»EClALTY 

COMMUNICATIONS  AWARD 
CLASS  A  1 

1  W20DA(RTTYJ  5  WD9GRI  (RTTYJ 

2  WBBOCD  ISSTVlf  5  WB5CDM  (RTTY) 

3  WB7BFK(RTTY)  7  N3AK0(RTTYJ 

4  WB9QCD{HTTY) 

DISTRICT  ENDURANCE 
AWARD 

1  AJAt  3  WB6CDM/7 

2  WL7ACY 


184     73  Magazine  •  December,  1980 


EUROPEAN  CONTINENT 

47  HK4DliM 

63  N4BQD 

55  WB2JUK 

88  VE3JGT 

DX  CAPITALS  OF  Tl 

HE  WORLD 

AWARD 

48  K9ri 

64  WD9HWY 

SB  K9TI 

89  KASCTZ 

1   WBIDQC 

6  K88JF 

49  WA2SRM 

65  WB7PK0 

5f  KA2K 

70  WDSDEL 

Z  WB7BFK 

7  WD4DV2 

1  WBSVPA 

83  W200A 

50  WD9{IC 

66  NiAMi 

56  K4L0 

71  WB6CDM 

3  K1TH 

B  WIAGA 

2  K4HRG 

84  WB2MVC 

51   W1AGA 

67  WDBQEO 

59  ICSOGS 

72  KS6LT 

4  WD4KRK 

9  N9GP 

3  KE4E 

65  K4BYK 

52  WB3JUK 

ea  VE3JGT 

60  DAIQR 

73  NiGP 

■I              ^  BT     ^^r      r    ■    ^  n     B  ^    ^ 

5  0J2UU 

4  N6TK 

68  K&BJF 

53  WA2RVF 

69  WDBDEL 

81   SSAAT 

74  KBSOB 

t#        4#  U  ih  %J  %^ 

5  WAISMI 

87  WA2PIP 

54  KA2K 

70  WBGCOM 

62  AG5X 

75  NBBJQ 

73  DX  COUNTRY  CLUB  AWARD 

€  WB3ICM 

88  K82DE 

55  K4LQ 

71    KB8LT 

83  K98IL 

78  N7AHO 

j'^HJ     ri^i^H  ^m 

7  VE1BV0 

89  WS7PKD 

W>  DA1U0 

72  NiGP 

84  WD9HWY 

77  K5BLV 

2XSSB 

a  WA9BBX 

70  NBAC 

S7  1C80GS 

73  KB8DB 

66  N4@QD 

78  DJ2yU 

1  viresvPA 

28  W5ZKJ 

9  WBilYMR 

71   SflAAT 

Se  DAlQR 

74  NSBJO 

66  N«AMI 

79  WB7RUV 

2  WB3tCM 

27  WB71XY 

10  WB6WI/9 

72  WfHIlU 

59  WDtAVG 

75  KSBLtf 

67  WOaQEO 

80  S8AAP 

3  WBIDQC 

28  F2YS/W2 

11   WfHMA 

73  WCHIIU 

iO  AQ5X 

76  DF9ZP 

4  N6TK 

29  WA2GyM 

12  We3BAP 

13  WOeMGQ 

74  KAtCBD 

75  WMAVG 

81  KB4JA 

82  K9BIL 

77  SaAAP 

78  WB7RUV 

WORK  THE  WORLD  AWARD 

S  WAISMI 

8  WB6WU9 

30  Ka4NJ 

31  KB4JA 

14  W©7BF*Q 

76  WP9IIC 

I  weavpA 

37   K4BTK 

7  WDBMGQ 

32  DJ2UU 

15  W61DOC 
1i  WAlS^UM 

77  W1AGA 
TB  WB3JUK 

AFRICAN  CONTINENT  AWARD 

2  IC£4E 

3  W86WV9 

38  K6&IF 

39  KB20E 

8  WB7BFK 

9  WB9JBH 

33  K9MD 

34  K4BYK 

17  N9ND 

79  WtQRyf 

1   WB8VPA 

43  DJ2Uy 

4  WD6MGQ 

40  WAISMI 

10  KUSY 

35  K88JF 

11  K4B0Z 

60  KA2K 

3  K4HRQ 

44  WEMKRK 

5  W8F8FK 

41    DA1MV 

11  K6WD 

36  HK4CKIM 

19  KUSY 

61   PY6ZLC 

3  KE4E 

45  K9ii1l 

6  Wfi1tX3C 

42  HK40UM 

12  WA2JCX 

37  S8AAT 

SO  NGPV 

82  K4L0 

4  WAISMI 

46  N7BZ 

7  KiJSY 

43  WDgilC 

13  KITH 

38  ICSOGS 

21   KA&CQJ 

83  DA1UQ 

5  WB3ICM 

47  W20DA 

8  W7ULC 

44  W1AGA 

14  K9PSI* 

39  K9T1 

22  W8CKV 

84  IC60GS 

6  WB6VVW 

48  K4BYIC 

9  K6W0 

45  WB3JLJK 

15  WbUO 

40  SV1IW 

23  KITH 

IS  DAIQR 

7  WB3BAP 

49  K8SJF 

10  K4HR0 

46  KA2K 

16  WDBMOV 

41  W&3JUIC 

24  W7ULC 

Be  AG5X 

a  W06MGQ 

SO  KB20E 

11   WD9HRH 

47  Km 

17  0A1MV 

42  WA2RVF 

25  N9ADI 

87  KSeiL 

9  WB7BFK 

51    N9A0L 

12  WDBMOV 

48  K4LQ 

18  WD4DVZ 

43  KA2K 

^  KBWD 

88  N4BQD 

10  WB1DQC 

m  S8AAT 

13  APIS 

49  NBAC 

19  WB3CfW 

44  9G1LL 

27  WIYBV 

89  WA2LYF 

11  KiaSY 

S3  K5T1 

14  WBiLXtl 

SO  ICSOGS 

70  KBSIS 

45  DAIQR 

2a  W9NAX 

SO  WD9HWY 

12  KASCCM 

54  HK40UM 

IS  WB3ICIi 

51    DAIQR 

21   KL7EO 

46  DA5CTZ 

29  WA2SI1M 

91   WBOCDM 

13  K1TM 

5S  WDgilC 

18  WB7fXY 

52  AG5X 

22  EA6ET 

47  VE3JGT 

30  WDSHftH 

92  W080EL 

14  W7ULC 

56  W1AGA 

IT  WMCIW 

S3  SSAAT 

23  WA2YEX 

46  WBfrCDIi 

31  WDBMOV 

93  KA5CT2 

15  K8WD 

57  WB3JLIK 

18  K1TW9 

S4  KB4JA 

24  N4ADJ 

49  N4AK0 

32  K9PSI4 

94  V63JGT 

1fi  WD9HRH 

58  WA2RVF 

19  F2YSW2 

55  K98IL 

25  WA2&R1I 

50  DF9ZP 

33  AD1S 

9&  WD80E0 

17  WDBMOV 

59  PYBZLC 

20  KB71P 

56  WD9KWY 

34  DAihirv 

96  NIAMI 

IB  AD1S 

m  K4LQ 

21   AJ8L 

57  WB7PKD 

.^  ^            ■    a  ■   tfh  j-m.   .^tm.  VW  A.  ^ 

73  DX  COUNTRY  CLUB  AWARD 

35  KmOBH 

97  W8EVH 

19  DA1MV 

61    DAtUO 

22  WBtYMR 

58  WB6CDIM 

Miypn  Mon^ 

3«  WBiLXM 

98  WD8EPV 

30  WB4LXM 

62  icaoGS 

23  AC3Q 

59  WDBDEL 

iVilACM  nnu^T 

h^^ 

37  WB7TXY 

99  AMY 

21  WB7TXY 

63  DAIQR 

24  SM5AKT 

60  VE3JGT 

1  WttANZ 

12  JK1VRQ 

aa  WB3CIW 

100  WBSSND 

22  WB3CIW 

64  AG5X 

25  WD9EPE 

81   WDSQEO 

2  K4HRG 

13  WB4SXX 

W  F2YSW2 

101    KA4KST 

2S  K9PSN 

6S  K9BIL 

26  JH1VR0 

62  N«AMI' 

3  WDSDKG 

14   N7BZ 

40  KSZIP 

102  K87D 

24  F2YSW2 

66  N4B0D 

27  K9PSN 

f^-\  N4BQ0 

4  KflZlP 

15  WSCHV 

41   0K5WJ 

103  WD4BLU 

25  KSZIP 

67  WD9HWY 

28  WD40VZ 

S4   K8SLT 

5  AASZ 

16  WDiEPE 

42  WA2YEX 

IM   KB8LT 

26  WA2yEX 

68  W&7PK0 

29  WSTJO 

65  N9GP 

6  KA5COJ 

17  WA1GTQ 

43  AJSL 

105  NiOP 

27  AJ6L 

69  WBBCDM 

30  W&dOZO 

88  K86D8 

7  K1VK0 

16  WD9IIC 

44  AC3Q 

106  KB9D0 

28  WB8YMR 

70  WDaDEL 

31  WB4SXX 

87  NBBJO 

8  WDBDZO 

19  PYSZLC 

45  SMSAKT 

107  AI6I 

29  AC30 

71   KA5CTZ 

32  WD4KRK 

88  KSBLV 

9  AC3Q 

20  K4L0 

4€  WDHEPE 

106  N4AK0 

30  WA2SRM 

72  VE3JGT 

33  K9M0 

69  DJ5UU 

10  WB0YMR 

21  W2XQ 

47  W4JYD 

109  N3AK0 

31  SM5AKT 

73  WDBQEO 

34  N7BZ 

70  WB7RUV 

11    K4JY0 

4S  JH1VR0 

110  KeaoB 

32  W8CHV 

74  NIAMI 

35  WB3BAf* 

71   S8AAP 

49  WB3BVL 

111   NBBJQ 

33  W&9EPE 

75  KBflLT 

36  WBCHV 

73  DX  COUNTRY  CLUB  AWARD 

50  K9TI 

112  KSBLV 

34  K4JYD 

76  NBGP 

2XCW 

51   WD4gv2 

113  DF9ZP 

35  N8AC 

77  N4AK0 

WORKED  ALL  USA  AWARD 

52  WB2FFY 

114  KiSOU 

36  JH1VRQ 

78  KBBDB 

MIXED  BAND 

1  AA8Z 

5  WB7PKP 

53  WSTJO 

54  WD8DZ0 
65  KB4JA 

115  KBQAK 
lie  KBGAK 
117  N7AHO 

37  W04DVZ 
36  WB2FFY 
39  WSTJO 

79  NBBJQ 
BO  K5BLV 
B1   DF9ZP 

1  KA1CBD 

2  WD80MS 
a  WD4RAF 

18  K6ARE 

17  NBBKB 

18  WL7AHL 

2  W7ULC 

3  SMSAKT 

4  WDSMAS 

6  WiYBV 

7  WB^FFY 
B  WB3BVL 

56  WB4SXX 

118  KA4ITQ 

40  WD6DZ0 

82  SBAAP 

4  KA3CBC 

19  WNSMBS 

57  DJ2UU 
55  WD4KRK 

119  W80LL 

120  N1BCV 

41  KB4JA 

42  WB4SXX 

83  WB7RUV 

5  KA9DLI 

6  KA4HEP 

20  KA4GML 

21  WB7RBH 

WORKED  ALL  USA  AWARD 

59  K9MD 

121   WB7RUV 

7  KLfEO 

22  WDSLCE 

R  lUtFTFR^ 

60  1^7  BZ 

122  WDiLYA 

OCEANIC  CONTINENT  AWARD 

B  KA4DNW 

23  WB3BVL 

o  lYic  1  ^n^ 

h^ 

6t  JA1VDJ 
62  K1K0B 

123  DA2AL 

124  SBAAP 

1  WB6VPA 

2  K4HRG 

28  KSZIP 

29  AJBL 

9  N4ACS 
to  N7AG0 

24  WD6EQP 

25  KB4NJ 

1  WS8ZKG 

2  K6PHE 

3  KE4E 

30  AC30 

t1  KAaOBN 

26  WAiCED 

10  METERS 

ASIAN  CONTINENT  AWARD 

4  N6TK 

31  SMSAKT 

12  KB5NE 

27  WD9GFL 

1  KL7IEN 

4  JKSDSC 

1   WBBVPA 

24  AJ8L 

5  AA8TK 

32  WD9EPE 

13  K2EQy 

28  KA3CGfA 

2  W52KJ 

5  VK7N8T 

2  K4HHG 

25  AC30 

G  WB31CM 

33  K4JY0 

14  KAGFYQ 

29  KB7EY 

3  VElflVO 

3  KE4E 

26  5M5AKT 

7  WD6EEQ 

34  N8AC 

IS  K4JYD 

30  AFSO 

4  wBarcM 

27  wm^PE^ 

S  WBBVVI^ 

3S  JHtVRQ 

4 e  WM ex E n 

b#^ 

i  WB6WU9 

28  iHlVflO 

6  WDBMGO 

36  W04DVZ 

CENTURY  CITIES  AWARD 

15  METERo 

5  WOeMGQ 

29  K9f^N 

10  WB7BFK 

37  W5TJQ 

1   K2ftlF 

10  M8BKB 

1  W05DRB 

3  KAfiACO 

7  WB7BFK 

30  WO90VZ 

11  WBTDQC 

2W  WDBDIO 

2  WA2SRM 

11   KB8JF 

2  WAiCEL 

4  WB6CDM 

8  WS1DOC 

31   W£i1JQ 

12  KiJSY 

39  KB4JA 

3  W04flAF 

12  WDiEPE 

9  KUSY 

32  W06D20 

13  N6PV 

40  WB4SXX 

4  KAiAZQ 

13  WtAGA 

20  METERS 

10  WTULC 

3,1  W84SXX 

14  KASCOt 

41   WD4KRK 

5  KITH 

14  KA2CLQ 

1   WA9BBX 

4  KB8JF 

11   KBWD 

34  Oi2UU 

15  W8CHV 

42  K9MD 

8  K4JY0 

1$  KA6F0Q 

1            W  r^K#  HiV  nr  r^ 

2  WA9WGJ 

5  WDiEPE 

12  WD9Hf%H 

35  WD4KftK 

16  KITH 

43  N7BZ 

7  WA9WGJ 

16  KA4BNO 

3  KITH 

13  WDBMOV 

36  K'^mo 

17  W7ULC 

44  JA1VDJ 

8  KA4HEP 

17  weecoM 

14  A01S 

37  N7SZ 

18  KBWD 

45  WB3BAP 

9  JHBDSC 

18  AK2H 

M  jn      H  ^>  ^■^^-^H-  ■■. 

15  DAIUV 

38  JAtVDJ 

19  WD9HRH 

m  K4iYK 

40  METERS 

IS  WBtUtM 

39  WB3BAP 

20  WD8M0V 

47  KB81F 

10  METER  DX  DECADE  AWARD 

1   WA2SRU 

3  WD4E}BJ 

17  WB7TXY 

40  W8CHV 

21  A01S 

48  ICS20E 

1   WB4WRE/M 

4  WDiAVG 

2  N8AZD 

4  WDtBOS 

18  WB3C1W 

41   K4BYK 

22  WStLXM 

49  WMSm 

2  AC3Q 

S  DA2AL 

19  KITH 

20  F2YSW2 

42  K68Jf 

43  KB£[>£ 

23  WBIYMR 

24  WBTTXY 

50  WB7PKD 

51  DA1MV 

3  WST^Q 

75/60  METERS 

21  Kazip 

22  WBtYMR 

44  WAISMI 

25  WB3CIW 

26  K9PSN 

52  HK4DUM 

53  wmitc 

TEN  METER 

'10-4ir  AWARD 

1  KAiAZQ 

2  WDtBOS 

4  KS4B 

5  We9UK5 

23  WA2YEX 

46  N8AC 

27  F2YS/W2 

54  W1AGA 

1   W60LAf7 

2  K4JSM9 

3  KA5A0P 

73  Magazine  •  December,  1980    105 


NEIV  PRODUCre 


from  page  32 

stees:  Model  DTl-6  (8**  wide), 
Model  DTE-1 1  (10.65"  wideK  and 
Model  DTE-1 4  (14"  widej.  The 
overall  height  of  the  series  Is 
3,15  inches  and  the  depth  is  8,25 
inches. 

For  furthef  Information,  con- 
tact Jsmeco  Efectronics,  1355 
ShorBway  Road,  Befmont  CA 
94002:  (475)-592'8097.  Reader 
Service  number  479. 

HEATH  CONTrNUING 
EDUCATION  INTRODUCES 

NEW  ICTlMEftS  SELF* 
INSTRUCTION  PROGRAM 

Heath  Continuing  Edocation 
has  announced  a  new  seIMn* 
struction  program  which  covers 
integrated  circurt  timers.  The 
new  program,  Model  EE*103,  in- 
cludes an  introduction  to  the 
common  types  of  10  tirfiers,  how 
each  works,  what  they  do,  and 
where  they  are  used. 

Among  the  types  of  IC  timers 
covered  are  the  popular  555  and 
556  series  genera l-purpose  tim- 
ers, the  322  and  3905  wide- 
range,  precision,  monostable 
timers,  and  programmable  tim- 
er/counters—including  the  2240 
binary  programmable  timer/ 
counter,  the  2250  BCD  pro* 
grammable  timer/counter,  and 
the  8260  seconds/minutes/ 
hours  BCD  programmable  timer/ 
counter. 

The  program's  self-teaching 
text,  with  the  assistance  of  re- 
view quiz  questions  and  lab  ex- 


periments, completely  covers 
how  each  timer  works  and  how 
each  is  used— m  logic  func- 
tions, output  drive  circuits,  lime- 
delay  relay  circuits,  wide-range 
pulse  generators,  phase-locked 
loops,  universal  appliance  tim- 
erSt  and  as  precise  clock 
sources. 

All  of  the  electronic  compo- 
nents required  to  perform  the 
experiments  are  included  with 
the  program.  The  Heathkit  ET- 
3300  laboratofy  breadboard  is  a 
recommended  option. 

The  EE'103  IC  timers  course  is 
one  of  four  Electronic  Tech- 
nology Series  selt-instruelional 
programs.  They  are  designed  to 
provide  detaited  knowledge  tor 
engineers,  technicians,  and 
other  technical  people.  Other 
programs  in  the  series  include 
Operational  Amplifiers  (EE-IOI), 
Active  Filters  (££-102),  and 
Phase-Locked  Loops  (EE-104). 

For  further  information,  con^ 
tact  HBBih  Company,  Dept,  350- 
230,  Benton  Harbor  Mi  49022. 
Reader  Service  number  481. 

NEW  HAMTRONICS^  VHF  FM 
EXCITER  KtT 

Hamtronlcs  has  announced  a 
new  single  channel  VHF  FM  ex- 
citer called  the  model  T51.  Pat- 
terned after  the  popular  T50  ex- 
citer, the  new  unit  is  rated  at  2 
Watts  continuous  output  and  is 
contained  on  a  3-  x  5*inch  PC 
board.  It  is  available  for  the  28-, 
50-.  144-,  and  220-MHz  bands 
and  may  be  modified  for  use  on 


adjacent  commercial  bands,  Jt 
la  Ideal  for  control  links,  repeat* 
er  service,  telemetry,  and  other 
applications  for  which  a  small 
unit  is  required.  A  multichannel 
adapter  Is  also  available  to  ex- 
tend operation  up  to  5  channels. 

Features  Include  low-imped- 
ance dynamic  mike  and  high 
level  audio  inputs;  crisp,  clear 
modulation;  low  spurious  out- 
put; pre-wound  coiJs;  adjustable 
output  level;  and  buiit-in  test 
points  for  easy  alignment.  A 
commercial  grade  frequency 
stability  option  is  available. 

For  further  information,  con- 
tact Hamtfonics,  inc.,  65F  Moul 
Rtf..  Htifon  NY  J 44m  (7W)'392- 
9430,  Reader  Service  number 
476. 

CENTURION  ANTENNAS 

Centurion  International  has 
introduced  a  new  line  of  heavy- 
duty  telescoping  replacement 
antennas.  These  antennas  are 
fulMength  V4-wave  radiators 
providing  increased  efficiency 
for  radios  that  are  not  normally 
available  with  a  telescoping- 
type  antenna. 

Three  modefs  are  offered, 
each  fitted  with  one  of  the  five 
connector  configurations:  a 
straight  telescoping  antenna,  a 
flex*spring  model,  and  right- 
angle  mounting  model.  The 
right-angle  model  is  suitable  for 
radios  with  front-  or  rear-mount- 
ed connectors  or  test  equipment 
appllcationSp 

The  flex-spring  model  has  a 
shock  absorbing  spring  fitted  to 
its  base  to  provide  the  popular 
flexible  feature.  The  spring  Is 
protected  with  a  tight-fitting 
neoprene  sleeve.  The  sleeve  re- 
tains Its  flexibility  from  -SS""  C 
to  100*  a 

All  models  are  available  with 
a  choice  of  five  different  con* 


m 


Centunon's  tefescoping  anten- 
nas. 

nectors:  BNC.  TNC,  Pb259,  F, 
and  5/16-32  threaded  stud. 

For  further  information,  con- 
tact Centuaon  fnternationai,  PO 
Box  82846,  Lincofn  NE  66501; 
i4Q2)-4B7-449l .  Reader  Service 
number  477. 

GILFER'S  ALLBAND  RECEIVER 

WITH  24-CHANNEL  MEMORY 

OPTION 

G lifer  Associates  has  just  In- 
troduced In  the  USA  the  Japan 
Radio  Company's  NRD-515 
communications  receiver-  The 
NRD-515  continuously  tunes 
from  100  kHz  to  30  MHz  using  a 
100-Hz  "step'*  photo-type  en- 
coder. Received  frequencies  are 
read  to  100  Hz  and  the  PLL-syn- 
thesized  circuit  can  be  locked  to 
any  frequency  with  assurance 
that  the  drift  will  be  less  than  50 
Hz/hour.  The  rf/l-f  circuit  is  a 
double  conversion  upverter 
(70.455-MHz  first  i-f). 

The  ^'khz"  tuning  knob  moves 


HeaWs  fC  Timer  sefNnstruction  program^ 


Hamtfonics'  T51  VHF  FM  exciter  board. 


186     73  Magazine  •  December,  1960 


10  kHz  per  revolution  and  a 
momentary  '*UP/DOWN"  switch 
permits  rapid  frequency 
changes  at  200  kHz/sec.  There 
are  no  mechanical  tuning  stops 
and  the  all-electrical  band- 
switching  circuit  automatically 
tracks  from  MHz  to  MHz.  Also 
featured  In  the  NRD-515  are 
passband  tuning,  AM  broadcast 
preselection,  noise  blanker, 
10-  and  20-d8  switchabie  atten- 
uator, variable  bfo,  LSB/USB/ 
RTTY  offsets,  and  RIT.  Four 
switchable  selectmty  options 
are  available  (two  supplied). 

The  optional  24-channel 
memory  unit  eliminates  man- 
uatty  re-tuning  your  favorite  fre- 
quencies—just turn  the  channel 
selector  switch  and  the  receiver 
Is  automatically  and  completely 
re-tuned.  The  memory  is  non- 
volatile and  the  input/output 
data  base  is  a  22-bit  BCD  code. 
Other  optional  extras  include  a 
matching  loudspeaker  and  CW 
filters  of  600-  and  300-Hz  seiec- 

tivity, 

For  further  information,  con- 
tact Giifer  Shortwave,  Box  239, 
Park  Ridge  NJ  07656.  Reader 
Service  number  478, 

SONY  ICF-2001 
PROGRAMMABLE  GENERAL- 
COVERAGE  RECEIVER 

In  most  cases  a  portable 
radio  would  be  only  casually  in- 
teresting. But  most  cases  aren't 
like  the  new  ICF-2001  from  Sony, 

It  is  evident  that  frequency 
synthesis  and  scanning  tech- 
niques are  gradually  winding 
their  ways  into  the  manufacture 
of  reliable,  inexpensive,  con- 
sumer-oriented radio  equip- 
ment. The  little  Sony  package  is 
an  excellent  example. 

Approximately  the  physical 
dimensions  of  a  cassette  re- 
corder {12''  X  7"  X  2"),  the 
ICF-2001  features  a  liquid  crys- 
tal display  frequency  readout. 
Coverage  rs  150  kHz  through  30 


MHz  AMfSSBICSN,  and  76-108 
MHz  FM.  Frequency  entries  are 
made  via  a  standard  keyboard, 
registered  to  the  nearest  kilo- 
hertz  (nearest  100  kHz  on  FM). 
Fine  tuning  of  CW^SSB  in  the 
150  kHz-30  MHz  range  is  provid- 
ed by  an  accurately-calibrated 
thumbwheel. 

Frequency  readout  accuracy 
is  excellent,  fully  reliable  to  a 
few  hundred  Hertz.  Frequency 
stability  is  outstanding;  CW  and 
SSB  signals  are  readily  copy- 
able  from  power-on  until  you  get 
tired  of  listening!  A  series  of 
slaps  at  the  cabinet  caused  no 
shift  in  frequency. 

A  built-in  fouMoot  telescop- 
ing whip  antenna  is  adequate 
for  casual  worldwide  reception. 
Relative  signal  strength  is  indi- 
cated by  a  light  bar  graph  com- 
posed of  5  LEDs,  Signals  may  be 
peaked  by  the  use  of  an  anten- 
na-resonating thumbwheel. 

A  series  of  six  push-button 
memory  channels  may  be  used 
to  store  and  recall  any  six  fre- 
quencies between  150  kHz-30 
MHz,  or  76-108  MHz,  depending 
upon  which  band  is  switched  in. 
The  low-frequency  FM  band  al- 
lows monitoring  of  channels  5 
and  6  of  TV  audio  as  well.  And 
for  the  paranoids  among  us,  the 
common  bugging  frequencies 
between  36  and  92  MHz  may  be 
searched! 

For  the  hiint-and-peck  fre- 
quency hopper,  the  mrcropro- 
cessor  is  a  dream  come  true. 
Merely  load  suspected  channels 
into  the  six  memory  positions 
and  punch  up  any  one  of  them  at 
any  time,  Thd  non-volatile  mem- 
ory retains  the  frequency  entries 
even  with  power  disconnected. 

The  ICF-2001  also  features  a 
scanning  function.  Any  limits 
within  the  passband  being  re- 
ceived may  be  programmed,  and 
the  receiver  may  be  automati- 
cally or  manually  scanned.  A 
slide  switch  may  be  activated 


for  automatic  stop  when  a  sig- 
nal is  discovered. 

Tuning  is  also  accomplished 
by  the  push-button  scanning 
method;  any  frequency  dis- 
played serves  as  a  starting  point 
from  which  up  or  down  search 
begins. 

Tuning  or  scanning  speeds 
may  be  increased  by  another 
key,  raising  the  rate  from  1  kHz 
per  increment  to  10  kHz  (ap- 
proximately 4  or  40  kHz  per  sec- 
ond). On  FM,  the  rate  is  either 
400  kHz  or  800  kHz  per  second, 
corresponding  to  4  or  8  FM 
channels. 

Power  for  the  little  Sony  may 
be  chosen  from  3  internal  D 
cells,  4.5  V  dc  {accessible  from 
an  automotive  cigarette  lighter 
using  a  Sony  power  plug  acces- 
sory),  or  120  V  ac  (power  supply 
included).  If  you  are  tempted  to 
use  the  receiver  on  batteries, 
use  alkaline  cells. .  .current 
drain  is  a  bone-crushing  400  mil- 
liamps!  Yes,  microprocessors 
still  use  a  great  deal  of  power! 

But  How  About  Specs? 

The  promotional  and  owner's 
literature  give  us  little  meaning- 
ful insight  into  the  electrical 
specifications  for  the  ICF-2001. 
A  call  to  the  factory  was  of  little 
help,  as  even  the  product  man- 
ager did  not  know.  However, 
private  measurements  give  us  a 
little  more  information. 

Image  rejection  averages 
-35  dB  throughout  the  short- 
wave spectrum.  The  6  dB/60  dB 
selectivity  points  are  at  6  kHz 
and  17.5  kHz,  making  the  2001  a 
little  broad  for  serious  commu- 
nications work.  But  it's  about 
what  could  be  expected  from 
the  custom  2-pole  ceramic  filter. 

As  far  as  intermodulation  and 


spurious  signals  go,  we  found 
them  no  problem.  In  fact,  we 
couldn't  find  them!  Sure,  they  Ye 
there,  but  with  an  antenna  con- 
nected and  strong  or  weak  sig- 
nals being  received,  intermod 
and  spurs  were  virtually  absent. 

A  second  i-f  of  10.7  MHz  (first 
and  only  if  on  FM)  is  used  on 
both  frequency  ranges,  with  a 
first  conversion  i-f  of  66.36  MHz 
on  150  kHz-30  MHz.  Up-conver- 
sion  is  a  standard  technique  in 
frequency  synthesis  to  avoid  in- 
band  i-f  images. 

The  2001  sports  9  ICs,  11 
FETs,  42  bipolar  transistors,  24 
diodes,  5  LEDs,  and  1  large- 
scale  IC  microprocessor  chip. 

Swell,  But  Does  It  Work? 

You  bet!  The  ICF-2001  is  an 
extraordinary  performer  for  a 
portable.  Our  first  experience 
with  the  little  unit  was  with  the 
self-contained  whip  antenna  ex- 
tended. Punching  up  6  known 
SAC  SSB  channels  into  the 
memory  banks,  airborne  and 
ground  stations  worldwide  were 
received,  solid  copy.  Step-tun- 
ing through  the  ham  bands,  sin- 
gie-sideband  and  CW  stations 
were  easily  copied  with  excel- 
lent quality.  No  frequency  drift 
was  detectable  over  several 
minutes  of  portable  handling, 
carrying  the  unit  from  room  to 
room. 

Attaching  the  135-foot  win- 
dom  antenna,  we  fully  expected 
that  the  receiver  would  come 
apart  at  the  seams  from  signal 
overload.  Surprisingly,  although 
signals  were  much  louder,  the 
receiver  behaved  very  respec- 
tively. Some  signal  bleed- 
through  was  detectable  at  night, 
but  it  was  easily  removed  with 
the  attenuator  switch. 


Gilfer's  NRD'515  communications  receiver 


Sony's  fCF-2001  general-coverage  recetven 


73  Magazine  •  December,  1980     187 


We  haven't  even  discussed 
some  oi  the  other  features . .  . 
sleep  switch,  accessory  jacks, 
LCD  function  displays. 

In  Conclusion 

The  new  Sony  ICF-2001  is 
meticulously  designed,  ex- 
tremely functional,  compact 
and  flexible,  and  an  outstanding 
performer.  While  it  was  never  in- 
tended to  compete  with  a  Col- 
lins receiver,  it  makes  one  po- 
tent backup  receiver  and  a  fine 
vacation  portable  1 

The  Sony  iCF'2001  lists  for 
$32a  For  further  information, 
contact  Sony  Corporation,  4747 
Van  Damm  St.,  Long  Island  City 
NY  mot  Reader  Service  num- 
ber 484. 

Robert  Grove  WA4PYQ 
Brasstown  NC 

B&W  BROADBAND  FOLDED 
DfPOiE  ANTENNA 

it  would  seem  that  after  a  cen- 
tury  of  experimentation  with 
radiating  wtres,  every  possible 
configuration  of  single-wire  an- 
tennas would  have  been  ex- 
plored and  exploited.  But  new 
antennas  keep  popping  up, 
proving  that  experimentation 
still  is  wide  open  in  this  aspect 
of  Gommur^ications. 

During  the  1950s,  a  series  of 
articles  by  G.  L  Countryman 
W3HH  discussed  the  possibili- 
ties of  the  **titted  terminated 
folded  dipole."  The  T2FD,  as  it 
was  popularly  called,  was  a 
cross   between   a   resistively- 


terminated  rhombic  and  a  slop- 
ing folded  dipole. 

It  seems  that  B&W  is  im- 
pressed enough  with  the  com- 
mercial feasibility  of  such  a  con- 
trivance to  produce  a  similar  an- 
tenna for  both  its  mil  itary  and  its 
consumer  market.  The  model 
370-15  broadband  folded  dipole 
is  the  result. 

The  antenna  comes  fully  as- 
sembled, wrapped  around  two 
cardboard  tubes  tor  shipping,  H 
is  designed  for  continuous  fre- 
quency coverage,  3,5-30  MHz. 
The  antenna  dipole  is  construct- 
ed of  #14  stranded  40%  copper- 
weld  wlre^  the  upper  and  lower 
dipole  sections  held  apart  by  six 
spacers  of  rigid  PVC  pipe. 

The  antenna  system  is  rated 
at  2.5  kW  (5  kW  PEP),  enough  to 
take  the  full  power  of  any  ama- 
teur-rated linear  amplifier.  Ad- 
weather  construction  ensures 
years  of  maintenance-free  op- 
eration. 

The  antenna  is  coupled  to  a 
balun  transformer  and  fed  by  ap* 
proximately  fifty  feet  of  perma- 
nent ly-^attached  RG-8/U  coaxial 
cable.  A  special  impedance  ter- 
minating  network  maintains  the 
constant  characteristics  of  the 
antenna  throughout  its  usable 
frequency  range. 

Installation 

All  large  dipole  antennas  are 
somewhat  unwieldy  to  Install. 
The  370-15  is  no  exception.  It  is 
recommended,  although  not 
mandatory,  that  two  people 
cooperate  in  erecting  the  anten- 
na. It  is  not  particularly  heavy, 


.^A 


A 


5    I  ■    THRHe  POLE    KVSTflLLATION 

'  "  FLAT  TOP"  AS  SHOWM   IM  SOLID-  LtNES 

INVERTED  *V'  AS   SHOWJ^   tN    BROKEN    LINES 


HZZ> 


TWO  POLE 
'FLAT   TOP" 


Fig.  1.  Typfcafin&taff&tions for B&W's 370-15 attband folded dipofe. 


but  it  is  ninety  feet  long,  con- 
sisting of  two  wires,  fifty  feet  of 
cable,  and  other  accessory  ac- 
coutrements along  the  way! 
Merely  keeping  the  copperweld 
wire  from  kinking  is  important 
and  requires  attention  while  un- 
rolling the  dipole. 

B&W  recommends  using  the 
allband  dipole  in  one  of  three 
configurations:  a  sloper,  a  flat- 
top, or  an  inverted  V.  Among  the 
three,  the  sloper  is  the  best  all- 
around  antenna,  Jt  requires  only 
one  high  and  one  low  support 
and  rt  is  essentially  omnidirec- 
tional. The  manufacturer  recom- 
mends  an  upper  height  of  24  to 
40  feet,  allowing  six  feet  of 
clearance  for  the  lower  support. 

Our  Experience 

The  ninety-foot  dipole  posed 
no  particular  problem  in  installa- 
tion even  when  erected  by  one 
individual.  By  anchoring  the 
center  of  the  antenna,  the  re- 
maining lengths  are  easily  un- 
furled, ready  for  elevation. 

Although  fifty  feet  of  coax 
may  seem  like  a  lot,  keep  in 
mind  that  a  ninety-foot  antenna 
is  an  imposing  length  to  permit 
the  coax  to  come  close  to  the 
shack.  Add  to  that  the  fact  that 
the  antenna  must  be  removed 
trom  metallic  influences  (siding, 
electrical  and  power  line  wiring, 
metal  roofing,  air-conditioning 
ductwork,  automobiles,  etc.), 
and  you  may  very  well  need  an 
additional  length  of  feed  line;  I 
did. 

Additional  feedline  at  fre- 
quencies below  30  MHz  is  no  lia- 
bility- Even  the  smaller  RG-SB^U 
would  be  perfectly  satisfactory 
for  another  fifty  feet  or  more  if 
power  levels  on  the  order  of  200- 
300  Watts  are  all  that  will  be 
usfed.  Line  loss  is  insignificant. 

After  erecting  the  folded 
dipole  as  a  sloper,  we  loaded  It 
with  a  Drake  TR-7  for  our  field 
trials.  Sure  enough,  the  vswr 
curve  on  all  bands  was  very 
close  to  that  shown  on  a  graph 
which  accompanies  the  instruc- 
tions. Curiously,  there  is  a  vswr 
hump  on  40  meters,  rising  to 
nearly  3:1  at  our  location. 

With  one  end  of  the  dipole 
tied  to  a  35-foot  tree,  we  moved 
the  lower  end  around  the  yard, 
testing  its  response  on  all 
bands.  Proximate  metallic 
masses  {a  power  line,  a  utility 
shed,  the  car)  showed  their 
deleterious  effects  on  the  anten- 
na. Clearly,  the  antenna  must  be 


mounted  as  free  from  reactive 
materials  as  possible. 

In  the  case  of  less-than-ideal 
environments,  the  use  of  an  ex- 
ternal matchbox  is  recommend^ 
ed.  While  the  matchbox  will  not 
help  the  reflective  and  absorp- 
tive tribulations  of  nearby  metal, 
it  will  keep  the  vswr  at  a  respect- 
able  level. 

Wind  and  ice  characteristics 
of  the  antenna  should  prove 
adequate  for  most  localities. 
With  end  supports  only,  100- 
mph  winds  may  be  tolerated— 
150  mph  with  an  additional 
center  support  pole.  Ice  accu- 
mulation of  40-50  pounds  (80 
pounds  with  center  pole)  is  also 
endurable  by  the  system. 

While  the  antenna  is  de- 
signed to  operate  through  30 
MHz,  chances  are  that  the  fer- 
rite  materials  in  the  balun  would 
behave  at  frequencies  some- 
what higher.  It  would  be  inter- 
esting to  find  out  how  the  anten- 
na would  perform  on  six  meters. 
With  ninety  feet  of  dipole  length, 
there  are  bound  to  be  some  di- 
rectional lobes,  as  there  are  on 
ten  meters. 

The  cost  of  the  B&W  antenna 
is  substantia],  but  for  allband 
performance  with  no  external 
feedline  tuning  necessary,  it  is 
worth  considering,  especially 
with  the  advent  of  the  new  ama- 
teur band  plan  obsoleting  many 
present-day  antenna  systems.   . 

B&W's  370-15  allband  folded 
dipole  lists  for  $149.50.  For  fur- 
ther information,  contact  Barker 
&  Wiffiamson,  Inc.,  10  Canal  St., 
Bristol  PA  19007.  Reader  Service 
number  483. 

Robert  Grove  WA4PYQ 
BrasstQwn  NO 

SC-76  SCANNING  MODULE 

The  S076  Is  a  low-cost  scan- 
ning module  lor  the  Kenwood 
7600  and  7625.  It  installs  in  a 
matter  of  minutes,  requires  no 
soldering,  and  comes  complete 
with  detailed  instructions.  Once 
installed,  it  is  placed  in  opera- 
tion by  turning  the  radio's  mode 
switch  to  position  "M*\  )t  then 
caifses  the  radio  to  scan  be- 
tween the  frequency  in  memory 
and  the  frequency  on  the  dials. 
Either  frequency  becoming  ac- 
tive will  stop  the  scan.  Normal 
operation  is  resumed  by  placing 
the  mode  switch  to  the  simplex 
or  offset  positions. 

For  further  information,  con- 
tact Karetron  Engineering  Co., 
PO  Box  241,  Middletown  OH 
45042,  Reader  Service  number 
482. 


las    73  Magazine  •  December,  1980 


W2NSD/1 


NEVER  SAY  DIE 

ec/Ztor/a/  by  Wayne  Green 


from  page  8 

read  guess-what  magazine  and 
talk  mostly  to  other  old-tim- 
ers, , .  all  who  have  20-year-old 
ham  gear,  factory  made.  .  ,all 
you  have  to  do  is  take  one  look 
at  the  number  of  pages  of  ads  in 
73  tor  parts.  Look  here,  if  hams 
weren't  building  equipment, 
those  f^rms  wouldn't  spend  all 
that  money  to  advertise  parts. 

One  of  the  hottest  microwave 
receivers  on  the  market  today 
was  first  designed  by  hams.  It 
did  so  well  they  went  into  busi- 
ness making  'em. ,  .and  these 
are  the  Cincinnati  Microwave 
"Escort*'  radar  detectors.  The 
hams  are  a  bunch  of  chaps  who 
spilt  from  Drake  and  went  into 
the  detector  business. .  .and 
are  cleaning  up.  Do  you  think 
they  would  be  doing  that  if  they 
hadn*t  been  hams  and  learned 
about  that  through  hamming? 

KILL  THE  LAWYERS? 

One  of  our  readers  (W2JTP) 
sent  along  a  copy  of  Industriai 
Communlcatfons,  a  most  inter- 
estmg  newsletter  v^hich  covers 
the  mobile  radio  field,  among 
others.  There  was  an  article  on 
the  state  of  the  art  in  spread 
spectrum  (SS)  connmunications 
such  as  was  pioneered  by  John 
Costas  in  1959,  when  I  pub- 
lished an  article  by  him  on  the 
subject  in  CQ.  Much  of  the  ex- 
perimentation with  these  tech- 
niques Is  presently  taking  place 
in  Japan. 

Let  me  quote  Industnal  Com- 
munications on  the  subject  of 
why  the  U.S.  commercial  sector 
has  not  pursued  this:  ^'It  ap- 
pears that  the  principle  'wet 
blanket'  in  this  regard  is  the  reg- 
ulatory  atmosphere  that  per- 
vades the  nation^s  capital.  The 
present  adversary  structure  and 
rigid  rulemaking  are  so  Incon- 
ducive  to  Innovative  technoio- 
gtes  that  the  prudent  industrial- 
ist Is  obliged  to  shift  his  ground 
in  miniscule  steps  or  not  at  all. 

Already  this  native  American 
technology  is  being  investi- 
gated more  seriously  in  Japan 
than  in  the  U.S.  It  would  be  sad 
indeed  if  a  burgeoning  new  field 


were  to  become  the  patented  re- 
serve of  another  country.  Per- 
haps as  a  first  step  in  regaining 
world  leadership  in  this  area,  we 
should  took  to  Shakespeare's 
Henry  VI:  Tirst  we  kill  all  the 
lawyers. ,  /  '* 

I  see  the  fault  lying  not  in  the 
restrictions  on  the  commercial 
field,  but  rather  as  a  fatiure  of 
amateur  radio  to  provide  the 
needed  pioneering  and  invent- 
ing which  is  our  responsibiiity 
. ,  ,and  to  hell  with  the  FCC  law- 
yers. I  don't  think  it  is  necessary 
to  kill  them,  just  find  honest 
work  for  them. .  .fixing  roads  or 
something. 

IT'S  LOBBY  TIME 

A  bill  (HR-7747)  has  been  en- 
tered into  the  legislative  log- 
jams which  could  cause  ama- 
teur radio  one  heil  of  a  headache 
if  we  don't  muster  our  forces  to 
beat  it  to  death  m  committee. 
This  is  a  matter  which  should  in- 
volve  every  amateur- .  .individ- 
ual ly  and  via  action  through 
ham  clubs.  If  any  ham  club  does 
not  take  action  on  this,  they 
need  restructuring  quickly. 

The  bill  fs  designed  to  protect 
the  interests  of  the  pay-TV  peo- 
ple, who  seem  to  be  utterly  para- 
noiac about  a  handful  of  experi- 
menters managing  to  see  their 
shows  without  helping  to  pay 
for  the  corporate  jets. 

Historically,  the  FCC  has  had 
a  strict  policy  of  protecting  the 
availability  of  aii  radio  frequen- 
cies  against  corporate  privilege. 
Despite  local  regulations  in 
some  cities  against  listening  to 
some  frequencies,  the  FCC  has 
stuck  by  their  manifesto  that  the 
airwaves  are  the  property  of  the 
people  of  our  country,  not  those 
wishing  to  use  them  for  making 
money  or  governing  us.  Thus  it 
is  and  has  been  legal  to  tune  any 
receiver  to  anything  you  wish. 

In  order  to  give  some  degree 
of  protection  to  the  users  of  ra- 
dio channels,  there  Is  a  rule 
which  prohibits  a  listener  from 
using  information  heard  over 
the  air  for  commercial  gain  or 
other  such  financial  benefit. 

This  freedom  to  listen  to  the 


radio  is  constantly  being  threat- 
ened  by  firms  which  want  to  use 
our  frequencies  for  making 
money  and  are  fearful  that  even 
a  tiny  body  of  people  will  tune  in 
without  paying  in  full.  Rather 
than  using  sophisticated  pro- 
tective measures  such  as  cod- 
ing of  the  signals,  they  have 
tried  to  use  their  lawyers  and 
their  lobbying  money  to  get 
around  the  FCC  through  Con- 
gress. Congress  reacts  positive- 
ly to  money,  as  we  know,  so  it  is 
a  logical  approach.  Congress  re- 
acts even  more  positively  to  an 
outcry  by  the  people  they  need 
even  more  than  the  lobbyists^ 
voters— and  in  this  case  this 
means  you,  your  family,  and 
your  friends. 

One  ham  should,  with  some 
motivation,  be  able  to  make  one 
hell  of  a  stink  about  something 
which  is  not  only  bad  for  the 
country,  but  in  particular  has 
very  ominous  portents  for  ama- 
teur radio.  You  know  as  well  as  I 
that  once  we  let  them  start  set- 
ting up  laws  prohibiting  the  use 
of  the  radio  spectrum,  it  will  be 
no  time  until  we  are  not  allowed 
to  have  all-band  receivers  or  to 
even  build  experimental  cir- 
cuits. 

WHAT  WAS  PURAC? 

This  was  an  advisory  commit- 
tee set  up  to  work  with  the  FCC 
and  help  them  to  cope  with  the 
growing  CB  problems  of  the 
mid-70s.  It  was  made  up  of  vol- 
unteers who  worked  at  no  cost 
to  the  FCC  to  solve  the  CB  prob-- 
lems.  The  committee  was  brok- 
en into  eleven  subcommittees, 
each  reporting  on  one  aspect  of 
the  interlocking  problems.  The 
committee  included  quite  a  few 
hams  and  brought  forth  a  report 
which  was  pubiished  in  three 
voiumes . . ,  a  most  authoritative 
report.  Unfortunately,  due  to  a 
shortage  of  funds,  oniy  ten 
copies  of  the  report  were  ever 
printed.  The  part  on  RFI  solving 
is  considered  by  many  in  the 
FCC  as  definitive.  The  PURAC 
committee  functioned  from 
1976  to  1978  and  was  decom- 
missioned by  the  FCC  when  the 
new  administration  came  in  and 
decided  that  there  should  be  no 
further  advisory  commtttees. 

In  fairness,  I  gather  that  this 
demolishment  of  PURAC  was  a 
case  of  overkill,  resulting  from  a 
desire  to  end  the  FCC  practice 
of  giving  out  contracts  for  re- 
ports... and  paying  dearly  for 
them.  This  was  a  juicy  iittle  busi- 
ness In  the  70s  and  attracted  a 


number  of  firms  which  had  fig- 
ured out  how  to  get  the  con- 
tracts and  how  to  fulfill  them,  all 
with  a  minimum  of  actual  work 
and  value  of  the  end  reports. 
Having  participated  in  one  as- 
pect of  this  and  having  gotten  a 
good  look  at  how  the  whole  sys^ 
tern  worked,  I'd  say  it  was  a 
good  move  to  put  a  stop  to  that 
boondoggle. 

REPEATERS  CAN  SAVE  LIVES 

Perhaps  you've  read  about 
the  emergency  locator  transmit- 
ters (ELT)  which  planes  have 
aboard.  They  are  small  VHF 
transmitters  which  are  triggered 
in  a  crash  to  help  locate  the 
downed  plane.  Obviously,  the 
sooner  a  downed  plane  can  be 
found,  the  more  chance  there  fs 
that  survivors  can  be  saved,  so 
every  minute  helps. 

VHF  being  what  it  is,  and 
planes  which  have  crashed  be- 
ing on  the  ground  in  most  cases, 
ft  figures  that  the  higher  you  are 
when  listening  for  these  little 
low-powered  ELT  rigs,  the  better 
chance  you  will  have  of  hearing 
them.  So  what  is  up  in  the  air  as 
high  as  we  can  put  it?  Repeater 
stations,  of  course. 

It  makes  a  lot  of  sense  to  me 
for  every  repeater  site  to  have  a 
receiver  tuned  to  the  ELT  fre- 
quency so  that  any  transmis- 
sions on  this  channel  can  be 
picked  up  as  soon  as  they  start. 
You  still  want  to  be  able  to  use 
the  repeater,  so  the  ELT  would 
not  want  to  take  complete  con- 
trol, but  you  might  want  to  have 
the  repeater  stay  on  the  air  once 
an  ELT  signal  was  coming  In, 
perhaps  with  a  low-level  tone 
modulation  so  you  can  talk  over 
it  for  search  coordination. 

Advanced  tinkerers  might  set 
up  an  omnidirectional  antenna 
for  normal  ELT  listening,  with  a 
remote  switching  system  to 
change  to  a  directional  antenna 
which  can  be  rotated  via  the  re- 
peater. .  .and  the  peak  signal  di- 
rection {or  null)  indicated  in 
some  way.  I'll  bet  we  can  drum 
up  some  interesting  articles  on 
how  to  do  that!  We  need  'em 
anyway  for  eventual  remote  con- 
trolling  of  low-band  beams  via 
repeaters. 

Every  service  we  can  supply 
with  our  repeaters  is  another 
merit  badge  for  amateur  radio. 
All  of  us  should  be  thinking  in 
t^rms  of  putting  our  expertise 
and  equipment  to  the  public 
good  as  often  as  possible. . . 
and  then  making  darned  sure 
the  public  knows  about  it.  That's 


73  Magazine  •  December,  1980     189 


not  being  glory  hungry  or  cyni- 
cal about  it,  Just  being  practical. 
If  you  want  to  attract  more  kids 
into  hamming,  you've  got  to  be 
visible  and  make  it  seem  like  fun 
, . .  which  should  not  be  much  of 
a  challenge. 

All  is  not  perfect  with  ELT 
transmitters  either.  Sometimes 
one  will  go  off  unintentlonaUy 
due  to  being  set  wrong,  bumped^ 
or  even  jarred  in  a  bad  landing.  If 
we  have  more  people  listening 
to  the  channel,  we  will  put  pres- 
sure on  pilots  and  technicians 
to  be  sure  that  errant  transmis- 
sions on  the  ELT  channel  are  cut 
to  a  minimum  and  not  just 
shrugged  off. 

You  may  be  sure  that  Fd  tike 
to  hear  about  any  repeaters  set 
up  lo  help  with  the  ELT  situa* 
tlon. ,  .and  so  woutd  the  other 
readers. 

RADAH  JAMMING 

During  the  time  when  Chuck 
Martin  WA1KPS  and  I  were  mak- 
ing our  tests  of  the  10-GHz  ham 
gear. .  .and  running  up  our  rec- 
ord of  making  contacts  from 
here  in  New  Hampshire  to  seven 
other  nearby  states... we  did 
not  entirely  ignore  the  possibili- 
ties of  using  these  little  rigs  to 
interfere  with  police  radar. 

The  area  out  in  front  of  our 
Elm  Street  building  (with  the  73 
Magazine  ham  shack)  is  a  favor- 
ite haunt  for  both  the  local  and 
state  police.  It  is  at  the  top  of  a 
hill  rising  from  the  center  ol 
town  and  Just  over  the  lip  of  the 
hill.  The  result  Is  that  cars  come 
roaring  up  the  wide  highway  and 
tend  to  ignore  the  35-mile-per- 
hour  speed  limit .  . .  after  all,  it  is 
a  restricted  entry  road,  so  why 
drive  that  slowly?  As  they  come 
over  the  top  of  the  hill,  there  are 
the  police,  handing  out  speed- 
ing tickets. 

On  several  occasions,  I  tried 
zapping  these  money  makers 
with  our  10-GHz  ham  rigs,  but 
they  never  fazed  them.  After 
thinking  about  it,  I  realized  that 
at  10  GHz  the  likelihood  of  bemg 
close  enough  in  frequency  to 
really  interfere  was  remote.  You 
have  to  get  down  to  about  3  kHz 
and  you  just  aren't  going  to  be 
able  to  do  that. 

Upon  reflection,  1  can  see  that 
those  firms  making  fadarjam- 
ming  rigs  are  Just  seMing  smoke. 
Sure,  if  you  tuned  one  of  them 
up  exactiy  on  the  channel  of  a 
radar  unit,  you  could  get  it  to 
work.  But  as  soon  as  another 
radar  came  aJong,  you*d  get  into 
trouble  if  you  estpected  to  cause 


false  readings  on  it. 

Despite  the  come-on  mph  cal- 
ibration of  the  bogus  radar  jam- 
mers, I  suspect  that  the  main 
value  of  these  is  for^  0-GHz  ham 
experimenting.  I'm  sure  that 
many  73  readers  would  like  to 
see  more  articles  on  10-GHz 
equipment  and  tests,  whether 
the  stuff  will  jam  radar  or  not* 

THOSE  SILLY  EQUATIONS 

One  of  the  more  serious 
wastes  of  my  time  in  college 
was  the  time  I  spent  learning 
enough  to  pass  the  courses  on 
calcuius.  Tve  had  a  fundamental 
rute  with  73  down  through  the 
years:  Edit  out  the  math  equa* 
lions  unless  they  are  absolutely 
necessary.  They  rarely  are,  so 
you've  seen  precious  few  equa- 
tions in  73  during  its  twenty 
years  of  publication. 

To  give  you  an  idea  of  how  lit' 
tie  calculus  is  really  needed  and 
what  a  waste  of  time  it  is  in 
school,  harken  to  my  personal 
experience  with  it,  I  started  in 
college  in  1940  and  went  for  two 
years,  thus  taking  two  damned 
years  of  calculus.  Then,  urged 
on  by  the  government  to  cut  out 
all  this  college  nonsense  and  to 
get  out  there  and  fight.  I  joined 
the  Navy  (one  lousy  day  before 
the  Army  was  going  to  draft  me 
« .  .close  call!). 

After  a  year  of  schooling  in 
the  Navy,  I  was  shipped  out  to 
the  fleet  and  spent  the  rest  of 
the  war. .  .or  most  of  It. .  .on  a 
submarine,  making  five  war 
patrols  on  the  USS  Drum 
(83228),  Managing  to  survive 
that,  despite  stubborn  efforts  by 
both  the  Japanese  and  our  own 
Air  Force  to  put  me  into  the 
Silent  Key  columns,  I  eventually 
got  discharged  and  went  back 
to  college. 

Having  finished  afl  but  one  of 
the  calculus  courses  during  the 
first  two  years,  all  I  had  to  do 
was  breeze  through  that  one  re- 
maining course.  Easier  said 
than  done.  I  found  myself  with 
virtually  a  zero  recollection  of 
two  years  of  calculus.  It  had 
never  come  up  during  the  inten- 
sive Navy  electronics  school 
courses,  so  I'd  managed  to  com- 
pletely forget  everything. 

This  put  quite  a  strain  on  my 
first  term  back  at  school  be- 
cause f  had  to  first  go  back  over 
four  terms  of  calculus  so  I  could 
hack  the  fifth  term.  Boy,  did  f 
hate  thati 

Funny  thing... I  have  a  re* 
markable  memory  for  songs,  po^ 
etry,  and  operettas,  being  able 


to  sing  most  of  several  Gilbert 
and  Sullivan  operettas,  but  I  just 
had  no  recall  on  calculus. 

In  the  over  30  years  since  col- 
lege, I  have  had  no  occasion  to 
use  any  calculus,  despite  a  wide 
variety  of  work, ,  .and  the  edit* 
ing  of  several  thousand  manu- 
scripts. I  remember  enough  of  it 
now  so  I  am  not  intimidated  by 
the  use  of  calculus  and  I  know 
that  I  can  just  edit  most  of  it  out 
of  articles  without  hurting  them 
at  alL 

This  came  to  a  head  recently 
when  a  reader  sent  in  a  copy  of  a 
letter  he'd  written  to  Ham  Radio 
magazine  complaining  about 
their  excessive  use  of  math  in  a 
W2PV  article  series.  The  writer, 
who  is  quite  familiar  with  the 
math  involved p  took  the  editor  to 
task  for  letting  the  author  snow 
the  readers  with  the  totally  un* 
necessary  math. 

One  of  the  reasons  that  the 
scientific  calculators  did  not 
achieve  more  popularity  was 
that  there  were  no  instruction 
books  available  for  them  to  ex* 
piai  n  how  to  make  use  of  the  sci- 
entific calculations  which  they 
made  possible.  Few  business- 
men have  the  vaguest  notion  of 
what  chi-squared  represents, , . 
and  none  of  the  calculator  in- 
structions helped  them.  Most  of 
these  same  people  would  have 
loved  to  have  been  able  to  use 
the  calculator  to  find  out 
statistical  data,  If  there  had 
been  any  simple  instructions  on 
the  application. 

The  lack  of  such  instructions 
has  cost  the  calculator  people 
dearly.  I'll  bet  they  could  have 
made  millions  more  in  sales  if 
such  a  book  had  been  available. 

The  technical  articles  in  73 
are  the  equal  of  any  In  ham  mag- 
azines, but  we  do  try  lo  make 
them  easier  to  understand  by  fil- 
tering out  the  math  which  some 
authors  want  to  put  in , , .  mostly 
for  ego  purposes.  We  want  to 
make  It  easy  and  fun  to  learn, 
not  scare  the  hell  out  of  you, 

CROWD  PLEASER 

For  a  while  it  was  beginning 
to  look  as  if  every  newcomer  to 
two-meter  FM  would  eventually 
have  his  own  repeater  and  sit 
there  listening  to  it  kerchunking 
every  now  and  then  with  satis- 
faction. When  the  number  of 
channels  ran  out  in  some  areas, 
there  were  bitter  fights . .  .  oddly 
enough,  usually  over  the  most 
active  channels  rather  than 
those  merely  Sitting  there  un- 
used. 


A  recent  report  by  Stanford 
University  indicates  that  there 
are  some  new  techniques  which 
hams  should  be  checking  out 
. .  .techniques  which  could  pro* 
vide  us  with  three  times  as  many 
two-meter  channels  as  we  al- 
ready have.  This  would  enable 
us  to  have  three  times  as  many 
unused  repeaters  as  at  pres- 
ent. .  .and  three  times  the  num* 
ber  of  happy  repeater  owners 
kerchunking  away  every  now 
and  then.  And  think  of  the  joy  in 
Japan  when  a  whole  new  set  of 
ham  gear  is  needed! 

The  new  technique,  called 
Amplitude  Compandored  Side- 
band Radio  (ACSB),  has  some 
similarities  to  the  recently  dis- 
credited Narrow  Band  Voice 
Modulation  (NBVM)  craze  which 
the  ARRL  went  through  and 
then  dropped.  With  this  system, 
it  is  possible  to  have  voice  chan- 
nels every  5  kHz  on  the  VHF 
bands  without  interference.  It 
also  has  a  nice  benefit  in  that  It 
provides  about  a  10-dB  improve- 
ment in  reception  over  FM, 
which  takes  about  25  kHz  or 
so... despite  our  attempts  to 
contain  it  within  15  kHz. 

The  ACSB  signal  Is  a  side^ 
band  type,  but  with  some  differ- 
ences. It  has  a  voice  processor 
which  boosts  the  low  and  high 
frequencies  to  bring  up  the 
average  power  of  the  voice. , . 
plus  it  has  a  pilot  tone  about  7 
dB  weaker  than  the  peak  voice 
which  keeps  the  receiver  on 
tune  (AFC)  and  provides  decod- 
ing of  the  compandoring,  a  stan- 
dard signal  for  automatic  gain 
control  (AGO)  to  smooth  out  fad* 
ing  and  the  picket  fence  syn- 
drome. The  pilot  also  has  a  sub- 
audibte  FM  tone  for  selective 
calling.  In  some  ways  this  sys- 
tem is  quite  simifar  to  my  pro- 
posed automatic  identification 
system  described  recently. 

Of  course  we  would  have  to 
change  over  to  sideband  from 
FM,  which  would  mean  all  new 
rigs.  That  should  bring  about 
$5CX),000,000  in  joy  to  the  manu- 
facturers. It  is  not  difficult  to 
change  present  SSB  rigs  for  the 
new  system,  but  FM  gear  has  re- 
ceivers which  are  far  too  wide 
for  the  SkHz  channels. 

Needless  to  say,  I  would  like 
to  see  some  experimentation 
with  this  system  by  amateurs 
and  some  articles  on  it.  The  cir- 
cuits necessary  to  do  the  pilot, 
the  FM  subcarrier.  the  AFC,  the 
AGC,  the  compandoring,  and  all 
else  involved  are  t)eing  inte> 
grated  into  an  LSI  chip,  so  our 


190     73  Magazine  •  December,  19B0 


work  may  not  be  difficult 

The  5-kHz  channel  spacing 
would  mean  that  we  could  fit  80 
channels  between  146,00  and 
146.40,  where  we  now  have  26, 
none  of  which  can  do  well  if  any- 
where near  an  adjacent  channel 
repeater.  This  would  give  us  160 
channels  in  the  146-  and  147- 
MHz  repeater  segments  of  the 
band.  With  more  channelSt  we 
would  not  need  as  many  sim- 
plex channels  and  could  take  at 
teast  half  of  them  for  one-MHz 
split  repeaters,  giving  us  200 
channels  in  the  146-14S  seg- 
ment alone.  That  might  even 
take  care  of  Los  Angeles  for  a 
year  or  two, 

The  pilot  carrier  system 
would  fit  right  in  with  my  pro- 
posed identification  scheme, 
making  it  simple  to  locate  any 
individual  station  desired.  Each 
station  would  continuously 
send  out  identification,  allowing 
you  to  see  instantly  the  call  of 
anyone  using  the  repeater. 
Good-bye  kerchunking  and  bad 
language. 

The  doubling  of  the  range  of 
reception  for  repeaters  and  the 
elimination  of  most  of  the  fad- 
ing problems  by  the  system 
would  greatly  improve  our  re- 
peater coverage  and  value.  This 
would  also  help  with  hand  trans- 
celvers,  which  could  be  made 
smaller  due  to  the  lower  power 
which  could  be  effective.  Ten  dB 
is  equivalent  to  ten  times  the 
power,  so  a  one-watt  HT  would 
be  about  the  same  as  a  10  Watt 
mobile  rig  in  effectiveness... 
unless  we  throw  the  power  away 
with  a  rubber  duckie. 

Let's  see  what  we  can  do  to 
pioneer  this  idea. 

INFECTING  THE  ACNE  SET 

Now  that  It  is  no  longer  un- 
popular to  be  successful^  it  may 
be  possible  to  carry  the  mes- 
sage about  amateur  radio  into 
the  high  schools  and  turn  on  the 
students  to  hamming  instead  of 
pot  or  the  development  of  a  life- 
long dependency  on  tobacco  or 
booze. 

The  fact  is  that  we  have  one 
hell  of  a  message  for  the  kids, 
for  not  only  is  hamming  fun,  but 
it  also  is  one  of  the  best  keys 
one  can  find  these  days  to  get- 
ting an  edge  on  the  future.  Is 
there  any  question  In  your  mind 
that  the  electronics  field  is  not 
going  to  keep  right  on  growing 
at  a  healthy  rate  for  the  next  50 
years?  Every  sign  is  that  elec- 
tronics is  going  to  be  more 
mixed  Into  everything  we  do  in 


the  future  than  it  is  now.  .  .and 
that  includes  computers,  ob- 
viously. 

We're  heading  Into  a  world 
ful!  of  micro  communications 
devices  which  will  put  us  in 
touch  with  each  other  at  will  and 
be  able  to  gather  information  on 
a  magnitude  not  even  realized 
today.  The  bottom  line  in  all  of 
this  is  electronics. .  .and  how 
better  to  learn  and  be  ahead  of 
the  pack  than  to  get  sucked  into 
amateur  radio?  It  happened  to 
me  and  It  happened  to  you. 

Surveys  show  us  that  current- 
ly almost  90%  of  the  teenagers 
who  get  hooked  on  amateur  ra- 
dio are  going  into  electronics  in 
some  form.  We  also  know  that 
about  50%  ofthe  newly  licensed 
amateurs  are  either  14  or  15 
years  old,  so  it  is  obvious  that 
the  growth  of  amateur  radio  is 
tied  closely  to  the  growth  In  the 
number  of  eiectronics  oriented 
people. .  .who  are  or  will  be- 
come technicians  and  engi- 
neers. 

The  Japanese  took  clever  ad- 
vantage of  us  when  they  Insti- 
tuted a  code-free  ham  ticket  and 
thus  laid  the  groundwork  for  the 
incredible  amateur  population 
they  have  today.  Next  they  got 
their  amateurs  to  talk  up  ama- 
teur radio  In  the  high  schools 
and  get  ham  clubs  going.  The 
result  is  that  today  amateur 
radio  in  Japan  is  known  to  every- 
one  in  the  country  and  they  have 
nearly  one  million  hams,  virtual- 
ly all  active.  That's  almost  six 
times  our  active  hams,  and  we 
have  twice  their  populatjon.  Is  tt 
any  wonder  Japan  is  ahead  of 
us  in  technology? 

As  I  see  it,  the  future  of  ama- 
teur radio  as  well  as  the  future  of 
our  country  depends  on  how 
much  enthusiasm  our  ham 
clubs  and  repeater  groups  can 
put  into  developing  interest  in 
amateur  radio  in  the  high 
schools.  We  need  to  expose 
these  kids  to  hamming  and  get 
them  Involved  with  ham  clubs. 

One  approach  to  this  is  for 
your  club  to  set  up  a  demonstra- 
tion ham  station  in  the  local 
high  school  and  pass  out  litera- 
ture about  hamming  which  will 
explain  the  fuo  involved,  the 
practical  long-range  advan- 
tages, and  give  detai  I  s  on  how  to 
get  started.  If  you  keep  after 
'em,  you'll  have  plenty  of  kids  in 
your  classes  at  the  club. .  .and 
we'll  start  seeing  some  signifi- 
cant growth  in  amateur  radio 
again. 

if  you  have  someone  In  your 


club  who  has  some  experience 
in  public  speaking,  you  might 
get  them  to  go  around  to  the  lo- 
cal schools  and  explain  the  ad- 
vantages and  fun  of  amateur 
radio.  From  a  practical  stand- 
pointp  the  kids  could  hardly  ask 
for  a  better  hobby  since  ham- 
ming will  aim  them  at  the  pot  of 
gold  ahead  in  electronics. 

When  it  comes  to  being  a  suc- 
cess in  life,  It  is  a  lot  easier  to 
make  it  in  a  field  which  is  grow- 
ing than  In  one  where  the  field  Is 
dying... such  as  education.  I 
give  a  lot  of  talks  to  groups  on 
the  fundamentals  of  success 
and  I  usually  start  out  by  ex- 
plaining that  there  are  several 
time-proven  ways  of  investing 
your  life  so  that  you  will  never  be 
a  commefcial  success.  .  .never 
be  able  to  make  much  money. 
One  is  to  go  into  teaching.  Now 
this  may  be  very  rewarding  in 
spirit,  but  it  sure  results  in  very 
few  yachts  and  planes. .  .or  se- 
curity. Then  there  is  working  for 
the  government,  which  does 
have  security,  but  at  one  hell  of 
a  price  in  salary  and  opportuni- 
ty. Another  big  loser  Is  working 
for  a  large  corporation.  Again 
there  is  a  tight  lid  on  salaries, 
though  a  mere  handful  do  man- 
age to  work  up  into  the  90%  in- 
come tax  bracket.  It's  a  tough 
way  to  go. ,  ,and  you  can  get 
canned  at  anytime. 

So  if  the  direction  that  our  col- 
leges and  all  the  media  push  on 
us  aims  us  at  losing,  how  can  we 
aim  kids  at  careers  which  wllf 
give  them  the  probability  for 
making  real  money?  The  secret 
to  being  successful  is  to  plan  for 
it  and  work  at  things  which  will 
have  a  good  chance  of  resulting 
in  getting  rich.  Certainly;  consid- 
ering the  growth  which  has 
come  about  in  electronics  (and 
computers),  this  is  a  lot  better 
field  to  go  into  than  English,  art, 
or  law.  Just  what  we  really  need 
is  more  lawyers. 

Hamming  is  particularly  good 
because  it  gets  kids  into  the 
habit  of  thinking  about  their 
life's  work  more  than  the  usual 
eight  hours  a  day-  Hams  never 
really  stop  thinking  about  their 
interest.  Hundreds  of  hams  get 
Ideas  for  new  products  and  start 
up  small  firms  to  make  them . . . 
and  a  few  of  these  pan  out  well 
and  we  have  big  firms  such  as 
Drake  resulting  . .  -Electro- 
Voice,  etc.  Others  go  for  a  while 
and  then  fade  away,  but  the  ex- 
perience gained  by  the  entre- 
preneur is  invaluable  and  will 
surface  later.  When  I  meet  the 


heads  of  medium-sized  firms  in 
electronics,  it  is  rare  that  I  don't 
find  a  ham  heading  things  up. 

So  get  out  there  and  spread 
the  contagion. ,  Jet*s  get  the 
ham  virus  going  In  high  schools. 
You'll  enjoy  seeing  your  handi- 
work... the  kids  will  certainly 
benefit.  .  .amateur  radio  will 
grow  and  perhaps  we  can  even 
get  the  leadership  in  electronic 
technology  back  from  Japan. 

THE  CODE-FREE  HASSLE 

Some  years  ago,  in  response 
to  the  pressures  from  the  CB  in- 
dustry, I  could  see  a  concerted 
move  afoot  to  grab  the  ham 
220  MHz  band.  I  thought  we 
might  be  able  to  fight  this  off 
with  some  stratagems,  but  I 
wanted  to  make  sure  that  we 
were  as  well  covered  as  possible 
so  I  came  up  with  a  no-code  ham 
ticket  proposal  for  the  220-MHz 
band. 

My  strategy  was  to  give  the 
CB  manufacturers  an  out  which 
would  sell  equipment  for  them 
. .  .possibly  as  well  as  making 
220  into  a  CB  band,  but  which 
would  still  leave  it  a  ham  band 
and  thus  not  force  hams  out  of 
it.  The  growth  of  hamming, 
which  this  would  bring  about, 
was  needed... and  still  is.  By 
starting  people  in  as  hams  in- 
stead of  CBers,  I  felt  that  we 
could  exert  ham  influence  on 
them  to  upgrade  much  more 
than  we  could  if  they  were  just 
CBers. 

The  license  that  I  proposed 
was  not  a  sign-it-and-own-it  CB 
ticket,  but  one  which  would  be 
granted  by  ham  clubs  only  after 
people  Interested  graduated 
from  ham  training  classes  and 
passed  exams  in  very  simple 
theory,  operating  techniques, 
and  rules.  I  felt  this  would,  at  the 
same  time,  put  the  new  licen- 
sees in  touch  with  clubs  where 
they  coutd  continue  on  to  higher 
classes  of  license  and  experi- 
ence the  ham  spirit. 

The  proposal  I  made  also  spe- 
cified that  the  no-code  license 
part  of  the  band  would  be 
bordered  by  parts  of  the  band 
open  only  to  higher  classes  of  li- 
cense such  as  Technicians.  I 
had  in  mind  the  use  primarily  by 
repeaters  which  would  have  to 
be  operated  by  higher  class  li- 
censees and  would  thus  give  the 
newcomers  a  good  introduction 
to  amateur  radio  and  make  sure 
that  they  did  not  think  of  it  as 
CB.  That,  plus  the  ham  club  li- 
cense classes,  I  felt,  would  get 
these  new  people  aimed  in  a 


73  Magazine  •  December,  1980     191 


good  direction. 

If  the  band  were  set  up  with 
repeater  inputs  from,  say,  220.5 
to  222.0,  and  outputs  from  223.0 
to  224.5,  ttiis  would  provide  a 
iiaif  meg  on  each  end  of  the 
band  for  higher  class  operators 
(and  repeaters)  plus  a  full  meg  in 
the  middle  for  higher  class. .  .or 
perhaps  split  with  half  of  it  for 
the  new  class  simpleic  and  half 
for  higher  class. 

With  220  still  not  very  much 
used  in  most  areas  of  the  coun- 
try, this  concept  could  still  fly. 

The  plan  did  cause  some 
weakening  of  the  CB  industry 
ranks  and  it  helped  us  in  that  re- 
spect. I  also  got  after  my  friends 


in  Mexico  and  Canada  to  put  on 
their  pressures  to  stop  the  CB 
takeover  of  220  and  that  had 
even  more  of  an  Impact. 

When  I  first  proposed  the  no- 
code  license,  the  ARRL  was  op- 
posed to  it.  Then,  as  pressures 
from  the  industry  mounted,  they 
flopped  over  and  were  in  favor  of 
it.  Now  I  understand  that  they 
are  opposed  again. 

Seeing  what  a  no-code  ticket 
has  done  for  Japan,  with  many 
benefits  and  no  detectable 
drawbacks,  I'm  still  very  much  in 
favor  of  the  idea.  I  was  more  en- 
thusiastic before  Dick  Bash 
started  publishing  his  detailed 
cheat   sheets   on  the   FCC  li- 


censes, which  essentially  can- 
celled their  effectiveness.  Right 
now  the  only  thing  between 
anyone  wanting  a  ticket  and 
having  it  is  the  code  or  being  too 
cheap  to  buy  the  Bash  cheatos. 
Until  we  are  able  to  resolve  that 
mess,  Tm  not  inclined  to  push 
for  going  to  a  purely  written  no- 
code  ham  test. 

If  we  could  set  it  up  as  I  had 
proposed  with  ham  clubs  issu- 
ing the  licenses  to  those  people 
who  had  taken  and  passed  their 
courses  on  being  a  ham,  I  would 
again  favor  a  no-code  situation. 
There  are  some  probiems  to  be 
resolved  before  clubs  would  be 
able  to  have  the  right  to  issue 


tickets.  I  would  like  to  see  ama- 
teur radio  get  more  autono- 
mous, having  much  more  of  a 
say  in  our  regulations  and  the 
granting  of  licenses.  We  might 
be  able  to  work  out  a  system 
where  we  could  get  needed  rule 
changes  made  in  tess  than  ten 
years,  thus  allowing  amateur 
radio  to  keep  up  with  technolog- 
ical developments  instead  of 
jnaving  to  stay  at  least  ten  to 
twenty  years  behind. 

If  you  have  any  well-thought- 
out  ideas  on  a  no-code  license 
situation,  please  write  in.  None 
of  us  needs  any  emotional  out- 
burst or  other  red-neck  re- 
sponses. .  .just  good  ideas. 


LOOKm  WEST 


from  pBQB  12 

Frankly,  I  have  a  feeling  that  this 
is  where  the  problem  in  relation 
to  this  dismissal  order  comes 
from. 

While  I  cannot  speak  for  the 
Commission,  I  can  surmise 
what  transpired.  Mr.  Talley  sub- 
mitted his  petitions  under  the 
assumption  that  the  Commis- 
sion  understood  amateur  radio's 
internal  interpretation  regarding 
repeater  categorization.  He 
even  told  me  that  h^s  opposition 
was  toward  repealers  that  re- 
quired one  to  become  a  member 
of  some  club  or  organization  in 
order  to  use  the  repeating  facili- 
ties. Again  remember,  we  in 
amateur  radio  consider  closed 
and  private  repeaters  as  those 
which  restrict  system  access  to 
club  members.  But  the  FCC  did 
not  read  it  that  way.  To  the  Com- 
mission, an  open  repeater  is  ap- 
parently one  that  offers  no  con- 
trol over  system  operation, 
either  technically  or  operation- 
atiy.  At  least  that's  what  seems 
to  come  to  iight  when  you  read 
the  dismissal  order. 

Therefore,  tf  my  guess  is  right, 
a  system  that  has  some  form  of 
control  is  looked  upon  as  a 
closed  or  private  repeater.  It 
seems  to  have  become  a  prob- 
lem of  semantics.  They  have 
never  bothered  to  reseach  what 
we  in  the  amateur  community 
accept  on  a  day-to-day  opera- 
tional level.  The  Commission  ap- 


parently looked  upon  Mr.  Talley 's 
request  as  one  of  removing  all 
controls  and  guidance  from  re* 
peater  operation  and  reacted 
along  those  lines.  Unfortunate- 
ly, they  may  well  have  set  an  un^ 
welcome  precedent  and  started 
us  on  the  road  toward  reregula- 
tion  rather  than  continuing  with 
deregulation. 

Even  more  unfortunate  is  that 
in  using  the  rationale  they  have, 
the  Commission  has  overlooked 
the  true  intent  and  purpose  of 
Mr.  Talley's  filings.  In  my  view, 
Mr.  Talley  was  actually  raising  a 
Constitutional  issue.  His  con- 
tention is  that  amateur  repeat- 
ers should  be  by  iaw  available  to 
any  qualified  licensed  amateur. 
I  oppose  this  because  it  is  my 
sincere  belief  that  to  force  any- 
one operating  a  repeater  to 
make  it  available  to  anyone  is 
akin  to  forcing  him  to  provide  a 
service  for  another  person  that 
he  may  not  wish  to  provide  for 
that  person.  If  you  are  going  to 
open  all  repeaters  to  all  quali- 
fied amateurs,  then^  by  the 
same  token,  you  also  must 
make  ali  individual  amateur  sta^ 
tions  available  to  all  qualified 
amateurs,  regardless  of  where 
such  stations  are  located. 

The  concept  of  forcing  one 
amateur  to  provide  a  service  for 
another  is  what  I  object  to,  and 
this  has  nothing  to  do  with 
either  amateur  radio's  or  the 
Commission's  interpretation  of 


repeater  categorization.  \n  my 
opinion,  the  defeat  of  RM-2844 
was  justified,  but  not  for  the 
reasons  noted  In  the  dismissal 
order.  Had  H  been  stated  that 
the  reasons  l  have  outlined 
were  the  basis  of  their  decision 
to  deny,  then  I  could  agree  with 
it.  Maybe  it's  time  that  we  in 
amateur  radio  begin  to  educate 
those  who  regulate  our  service, 
get  them  to  understand  our  ter- 
minology and  definitions  in  re- 
gard to  our  day-today  opera- 
tions. If  this  can  be  achlevedt 
then  we  can  really  get  on  with 
things. 

There  is  nothing  wrong  with 
the  system  by  which  regulations 
governing  our  hobby  are  gener- 
ated. For  the  most  part.  It  is  peo- 
ple like  you  and  I  who  generate 
them,  for  better  or  worse.  We  are 
very  lucky:  In  most  other  places, 
rules  are  simply  by  government 
decree.  There  is  nothing  that  the 
amateur  can  do  but  abide  by 
them  without  recourse. 

Here,  in  America,  we  can  help 
generate  and  guide  the  destiny 
of  amateur  radio  through  the 
public  rulemaking  procedure. 
This  is  a  liberty  we  must  cherish 
and  utilize  for  the  good  of  our 
hobby.  But  we  also  must  find  a 
way  to  overcome  the  semantics 
problem  so  that  when  we  talk 
about  open  repeaters,  the  FCC 
understands  our  meaning  and 
we  theirs.  When  we  speak  of 
modes,  power  levels,  or  any- 
thing else,  each  must  know  the 
meaning  of  the  other's  words. 
This  will  go  a  long  way  in  devel- 
oping more  positive  lines  of  in- 
teraction between  those  of  us 
who  comprise  the  amateur  com- 
munity and  the  agency  that  reg- 
ulates our  operations. 


SHOULD  THERE  BE  PRIVATE 
REPEATERS  DEPARTMENT 

In  any  discussion,  we  must 
first  set  some  ground  ruies  for 
understanding.  In  this  case,  1 
feel  it  is  best  that  we  begin  by  re- 
viewing the  definitions  of  the 
three  categories  of  repeater  op- 
eration as  accepted  within  the 
amateur  community.  Over  the 
years,  the  following  definitions 
have  developed: 

Open  Repeat&f:  An  amateur 
relay  device  placed  into  opera- 
tion by  an  individual  or  group  to 
serve  the  needs  of  all  licensed 
and  qualified  amateurs  in  a 
given  area.  In  most  cases,  no 
form  of  tone  access  is  neces- 
sary  to  access  such  a  system. 

Closed  Repeater:  An  amateur 
relay  device  which  requires  that 
one  become  a  member  of  the 
sponsoring  organization  to  gain 
use  of  the  relay  system  facili- 
ties. However,  membership  in 
such  organizations  is  open  to 
any  interested  amateur  licensee. 

Private  Repeater:  An  amateur 
relay  device  which,  like  the 
closed  repeater,  requires  mem- 
bership in  the  sponsoring  organ- 
ization. However,  the  availability 
of  such  membership  is  at  the 
discretion  of  the  system  licen- 
see. Both  closed  and  private  re- 
peaters are  usually  tone  ac- 
cessed, and  such  access  tones 
are  considered  to  be  proprietary 
information. 

If  we  accept  these  as  our  defi- 
nitions of  operational  categori- 
zation, then  a  question  arises. 
Should  the  latter  two  be  per- 
mitted to  exist  in  today's  ama- 
teur society?  it  probably  de- 
pends upon  where  you  reside, 
conditions  of  crowding  on  vari- 
ous bands,  and,  most  important- 
ly, your  own  personal  taste.  I 


192     73  Magazine  •  December,  1980 


cannot  comment  on  the  last,  but 
in  regard  to  the  others,  I  have  a 
number  of  words,  some  of  which 
will  not  make  the  owners  of 
closed  and  private  repeaters  too 
happy.  What  I  have  to  say  differs 
from  earlier  commentary  that 
has  appeared  over  the  years  in 
this  column,  but  this  is  because 
of  the  ever-changing  face  of  the 
amateur  service  itself. 

If  you  live  out  in  the  boon- 
docks where  nobody  cares,  you 
can  basically  do  your  own  thing 
and  nobody  will  say  boo.  If  there 
are  only  three  or  four  repealers 
in  your  area  and  a  clear  band, 
then  I  do  not  think  anyone  will 
really  care  what  category  of  op- 
eration you  choose.  However,  in 
crowded  urban  areas  where  one 
finds  a  repeater  or  two  every  15 
kHz  between  146  and  148  MHz 
and  the  same  condition  every  20 
kHz  from  144.5  through  145.5 
MHz,  then  the  two-meter  band  is 
no  place  to  start  or  continue  a 
closed  or  private  device.  Two 
meters  has  become  "the 
people's  band"  and,  for  the 
most  part,  "the  people"  want 
and  demand  access  to  the  en- 
tire spectrum.  While  densely 
poputated  metro  areas  mfght 
have  been  able  to  toierate  a 
number  of  private  repeaters  on 
two  meters  only  a  few  short 
years  ago,  with  today's  spec- 
trum crunch  it  may  be  time  for 
those  wishing  this  category  of 
operation  to  look  toward  green- 
er, less  occupied  spectrum. 

I  have  no  qualms  with  cfosed 
and  private  repeaters.  In  fact,  I 
freely  admit  to  being  a  member 
of  two  such  entities,  but  neither 
of  these  are  on  two  meters.  Over 


the  past  several  years,  I  have 
been  invited  onto  a  number  of 
private  two-meter  systems  here 
in  the  Los  Angeles  area,  but 
each  time  have  declined  such  an 
invitation.  Yes,  there  is  a  pJace 
in  our  society  for  those  who 
want  their  privacy  and  there  is 
nothing  wrong  with  their  want- 
ing it.  But  the  urban  private  re* 
peater  of  today,  operating  with- 
in the  crowded  confines  of  the 
two-meter  band,  is  somewhat 
akin  to  a  case  of  the  ffu.  Neither 
is  very  welcome  anymore.  As 
time  progresses  and  the  spec- 
trum crunch  tightens,  they  will 
probably  become  a  definite  lia- 
bility within  our  amateur  com- 
munity. 

On  the  other  hand,  there  are 
bands  with  practically  no  utiliza- 
tion. This  holds  true  even  for 
areas  where  the  two-meter  band 
(s  saturated  with  24-hour-a-day 
activity.  Such  spectrum  would 
welcome  any  activity,  private  or 
otherwise.  This  is  where  such 
systems  belong,  out  of  the  main- 
stream of  today's  amateur  activ- 
ity. Further,  those  wishing  the 
luxury  of  operation  on  such  a 
system  should  be  prepared  to 
spend  the  extra  bucks  for  the 
necessary  equipment,  be  it  on  6 
meters,  220  MHz,  or  450  MHz.  (f 
you  want  the  luxury,  then  be  pre- 
pared to  pay  the  price  tag  that 
comes  with  it.  After  all,  the  vast 
majority  of  those  using  the  two- 
meter  band  are  not  that  inter- 
ested in  getting  on  a  private  or 
closed  system.  For  most,  ama- 
teur radio  is  a  recreation  and  not 
an  avocation.  I  can  see  no  rea- 
son to  displace  the  masses  in 
deference  to  the  few.  I  do  not 


condemn  private  or  closed  oper- 
ations. They  have  their  place 
within  the  structure  of  amateur 
radio  society  and  as  such  serve 
a  definite  purpose.  Many  of  the 
earliest  systems  had  restricted 
access,  and  from  them  has 
come  much  of  the  open  opera- 
tion of  today.  However,  in  areas 
where  the  two-meter  band  is 
overflowing  with  activity,  where 
the  coordinator  or  coordination 
council  has  a  waiting  list  a  yard 
long  for  new  open  repeaters,  the 
closed  and  private  category  sys- 
tem should  take  a  back  seat  to 
the  will  of  the  majority. 

SIX-METER  BAND  PLANNING, 
CONTINUED 

The  band  plan  outlined  in  the 
September  issue  on  page  163 
has  begun  to  get  some  re- 
sponse. What  I  find  very  scary  is 
that  thus  far  I  have  not  received 
any  negative  commentary. 
Some  suggested  changes,  yes, 
but  nothing  that  says  ''NO"  em- 
phatically, One  important  addi- 
tion that  i  want  to  note  concerns 
the  existence  of  another  Pacif id 
DX  corridor  It  was  not  brought 
to  my  attention  prior  to  the  for- 
mulation of  the  band  plan  and 
therefore  was  not  included. 

A  second  Pacific  DX  corridor 
does  exist  from  51,0  through 
511  MHz.  It  has  been  around  for 
some  time  but  never  has  been 
given  very  much  publicity.  So,  if 
we  were  to  obtain  deregulation 
down  to  51  MHz  for  FM  relay  op- 
erations, in  some  areas  it  might 
be  wise  to  keep  FM  away  from 
this  small  slot  to  protect  weak- 
signal   operations.  Again,  this 


would  fall  under  a  voluntary  pro- 
gram and  not  be  part  of  the  ama- 
teur rules  and  regulations.  It 
would  be  exactly  the  same  as 
the  Pacific  DX  corridor  that  ex- 
ists from  52,0  through  52.1  MHz. 
I  might  suggest  that  you  pencil 
this  into  the  band  plan  for  future 
reference. 

For  the  moment,  that's  about 
it  in  regard  to  six  meters.  More 
on  the  subject  will  be  included  in 
future  columns  and  as  com- 
ments come  in. 

FINAL  UPDATE  ON  STORY  ONE 

We  opened  this  month's  col- 
umn by  reporting  on  the  dismis- 
sal order  to  RM-2844,  an  order 
that  on  the  surface  seems  to 
eliminate  open  repeater  opera- 
tion. We  also  included  a  scenar- 
io on  what  we  hypothesized  as 
being  the  sequence  of  events 
leading  up  to  it.  Well,  informa- 
tion we  have  gathered  seems  to 
point  to  this  being  similar  to 
what  really  happened, 

tt  appears  as  though  the  order 
was  given  to  a  member  of  staff 
to  prepare  the  document.  The 
person  was  not  all  that  familiar 
with  Part  97  as  it  governs  repeat- 
er operation  and  wrote  the  docu- 
ment based  upon  his  own  under- 
standing. After  its  release,  a 
number  of  inquiries  were  made 
to  its  validity  and  it  was  brought 
to  the  attention  of  a  senior 
member  of  the  staff  who  agreed 
that  its  wordage  was  somewhat 
contradictory  to  the  rules  as 
written,  A  clarification  has  been 
promised.  It  should  be  forth- 
coming and  we  may  have  it  for 
next  month's  column.  I  hope 
that  it  will  clear  the  air. 


LETTERS 


from  page  24 

what  about  the  other  99%  of  the 
time?  Unfortunately,  although 
they  expect  us  to  operate  in  the 
public  interest,  we  really  can't 
expect  them  to  do  likewise. 

If  the  FCC  doesn't  resume 
testing  in  Germany,  there  is  only 
one  option  left.  That  is  to  rein- 
state the  Conditional  class  li- 
cense which  we  had  many 
moons  ago.  If  this  can't  be  done, 
then  they  should  put  the  testing 


program  in  the  hands  of  the  Ex- 
tras. The  FCC  would  undoubted- 
ly balk  at  a  suggestion  such  as 
this  because  of  past  problems 
concerning  "mail-order"  Techni- 
cians, But  I  am  sure  that  the  Ex- 
tra class  hams  can  run  an  hon- 
est and  sound  testing  system 
not  only  for  amateurs,  but  also 
for  the  commercial  applicants.  I 
have  already  earned  my  Extra 
class  ticket,  but  I  am  speaking 
for  the  hundreds  of  hams  and 
those  desiring  their  phone  li- 
censes. In  closing,  all  I  can  add 


is  that  "the  FCC  giveth,  the  FCC 
taketh  away." 

Harry  A.  Schools  KA3B/DA2AL 

APONY 

Thanks  for  tfre  fetter,  Harry;  you 
are  expressing  what  t  heard  ev* 
^ry where  f  went  In  Europe  a  few 
months  ago.  Perhaps  someone 
shouid  petition  the  FCC  to  solve 
the  problem  with  an  overseas 
CondltionsI  license  arrange- 
ment? The  major  problem,  both 
with  lack  of  growth  of  the  hobby 
and  with  the  FCC  problems, 
stems  from  our  lack  of  a  lobby  to 
push  for  amateur  radio  in  Wash- 
ington. .  .and  in  particular  with 
the  FCC.  it  is  completely  unfair 
to  blame  the  FCC  for  acting  like 
any  other  go)/ernment  bureau 
and  reacting  to  lobbying  pres- 


sures which  are  on  them  from  all 
sides. .  .except  amateur. — 
Wayne. 


[ 


ITS  A  MESS 


Every  time  1  read  an  article  or 
letters  from  readers  regarding 
FCC  decisions,  which  are  usual- 
ly negative,  causing  more  gov^ 
ernment  control  of  amateur  ra- 
dio and  more  restrictions,  I  won- 
der if  the  founders  of  the  Feder- 
al Communications  Commis- 
sion were  of  this  mind? 

Amateur  radio  has  been  the 
victim  of  the  Commission's  in- 
ability to  cope  with  their  bum  de- 
cisions on  CBers.  But  the  worst 
of  ail  Is  the  alphabet  soup  call 
letters  of  all  descriptions.  As  I 


73  Magazine  *  December,  1 980     193 


see  H,  it  is  further  degradation  of 
amateur  radio.  We  used  to  be 
able  to  tell  where  a  particular 
calisign  would  originate  from, 
but  not  now;  it's  a  mess!  Possi- 
bly, they  want  to  fracture  this 
sacred  organization,  i.e.,  to 
make  it  like  CB.  I  surely  hope 
not. 

I  have  been  a  licensed  ham 
since  1939  and  I  still  enjoy  ham 
radio.  This  brings  to  mif>d  a  re- 
cent overseas  contact  on  20  CW 
with  a  ham  in  northern  Norway* 
My  comment  that  I  had  been  an 
amateur  since  1939  brought  this 
response:  '1,  too,  am  an  old-tim- 
er, receiving  my  f  irsi  ticket  in  '38, 
and  I  dearly  love  my  hobby.'* 

Henry  S,  Mitchell 
Seattle  W A 

Henry,  a  lot  of  us  grumble  about 
the  fCC,  and  certamty  some  of 
the  rules  they  put  through  are 
for  political  reasons  srid  not  ir) 
the  best  interestB  of  the  hobby 
. . .  but  then  we  have  virtually  no 
iobby  there  to  deal  with  the  FCC 
and  guide  them  in  a  positive 
way,  so  we  can  expect  no  more 
than  we  get.  When  you  are  deah 
ing  with  government,  you  have 
to  do  things  the  government 
way,  and  this  means  lobbying 
for  your  hobby.  It  Is  useless  to 
get  mad  at  the  FCC  for  acting 
perfectly  normal  and  hold 
blameless  the  real  villains.., 
the  people  we  are  paying  to 
represent  us.  — Wayne. 


ANTENNA  CHOKES 

Tve  received  an  Interesting 
letter  from  Al  Stabler  AD6G 
commenting  on  my  article, 
"Check  Chirp  with  a  Choke/' 
which  appeared  in  the  June  Is- 
sue. Al  comments  as  follows; 
"IVe  used  a  similar  device  in  alt 
of  my  antennas— but  for  a 
slightly  different  reason.  The 
idea  is  to  remove  rf  from  the 
feed  lines.  King,  in  his  book 
Transmission  Lines,  Antennas 
and  Wave  Guides  (Dover,  1965), 
page  151,  states  that  common 
mode  currents,  i.e.,  antenna  cur- 
rents on  the  outside  of  a  coax  or 
antenna  currents  on  both  con- 
ductors of  a  parallel  feedfine, 
can  be  de-tuned  or  eliminated  by 
placing  a  high  impedance  to 
these  currents  at  a  point  on  the 
line  where  the  current  would  be 
maximum. 

"For  a  dipole  antenna,  the  op- 
timum location  for  the  high  im* 
pedance  would  be  at  the  feed- 
poinl  where  the  cyrrenl  is  maxi- 


mum, or  at  A/2  intervals  from  the 
feed  point.  I  have  found  that  a 
choke  coil  like  yours  placed  at 
the  feedpoint  of  a  dipole  is  much 
more  effective  at  eliminating  rf 
on  the  feedline  than  a  conven- 
tional balun.  I  no  longer  use  a 
balun,  just  a  choke. 

"Field  strength  measure- 
ments have  shown  that  the 
radiation  pattern  of  a  dipole  an- 
tenna IS  drastically  altered  when 
there  is  rf  on  the  feedline,  but 
the  addition  of  a  choke  at  the 
feedpoint  corrects  this  problem. 

*1  first  found  that  I  had  rf  on 
the  feed  line  when  I  noticed  that 
the  swr  was  different  at  different 
points  along  the  feedline.  With 
the  choke  insiailed,  this  prob- 
lem goes  away. 

**P.S.  If  you  resonate  the 
choke  with  a  variable  capacitor 
the  results  are  even  better!" 

Thanks  for  the  interesting 
feedback,  Al.  Resonating  with  a 
capacitor  had  not  occurred  to 
me,  but  for  singie-band  opera- 
tion, an  improvement  could  cer- 
tain ly  be  obtained  by  this  expe- 
dient. For  allband  operation,  it 
would  be  best  to  stick  with  the 
choke  method.  Another  applica- 
tion for  choke  isolation  of  unde- 
sired  antenna  currents  comes  to 
mind.  This  is  the  suppression  of 
rf  energy  from  the  shack  when 
necessary  to  eliminate  rf  burns 
resulting  from  contact  with 
"hot"  equipment. 

Stanford  J.  Solms  WA2MEL 

Sunnyvale  CA 


FUN-PEDITtONS 


Caribbean  vacation  spots  are 
certainly  not  DXpeditions— they 
are  DX  operations  or  are  some- 
times called  fun^pedltions.  Let's 
start  putting  DXpeditions  vs,  DX 
operations  in  true  perspective. 
True  DXpeditions  include,  but 
are  not  limited  to.  for  example, 
Malpelo,  Bouvet,  Okino  Torishi- 
ma,  Spratly,  et  al.  My  new  show 
is  all  of  these  plus  many  others. 
Hope  you  can  catch  my  show  on 
the  circuit.  It's  a  great  show. 

Hugh  Q.  Vandegrift  WA4WME 

Kiileen  TX 

We  7/  be  looking  for  you,  Hugh, 
and  be  sure  to  take  a  lot  of  good 
color  pictures  for  the  write-ups 
on  your  trip.  One  of  the  prob- 
lems with  some  of  the  earlier 
DXpeditions  to  many  of  the 
places  you  mentioned  was  that 
they  were  fakes.  At  least  when 
someone  says  he  is  on  a  fairly 
rare  island  in  the  Caribbean, 


there  is  a  good  chance  he  is 
where  he  says  he  Is.  But  remem- 
ber one  thmg,  Hugh:  If  I  haven't 
worked  a  particular  country, 
that's  DX  for  me  and  the  chap 
vlsitmg  is  on  a  valid  DXpedidon. 
The  bottom  line  is  fun. . .  the  fun 
of  working  DX  for  us  and  the  fun 
of  being  DX  for  you — Wayne^ 


OPERATOR'S  LICENSE 

With  regard  to  the  new  flap 
over  the  tactics  of  Mr.  Bash  and 
his  "educational  services,"  I 
would  like  to  add  some  addition- 
al comment. 

Personally,  1  never  could  un- 
derstand why  someone  had  to 
have  an  understanding  of  the 
workings  of  electronics  to  be- 
come a  ham.  Frankly,  it  stems 
from  the  old  days  when  you  had 
to  put  things  together  (home- 
brew) to  even  get  on  the  air  To- 
day we  are  flooded  with  state-of- 
the-art  rigs.  Who  needs  home 
brew  unless  you  are  personally 
interested  in  doing  that;  why  do  1 
have  to  know  the  stuff? 

Before  someone  jumps  on 
me,  rd  better  mention  that  t 
have  a  background  in  electron- 
ics and  work  for  an  electronics 
firm  here  and  was  originally  li- 
censed in  1957. 

Most  everyone  today  is  an  ap- 
pliance  operator  anyway.  What 
we  need  is  a  test  that  makes  all 
potential  operators  have  a  thor- 
ough knowledge  of  the  rules  of 
the  road,  proper  operating  pro- 
cedures, proper  use  of  radios 
and  tuning  up,  and  etiquette  on 
the  air.  As  far  as  I  am  concerned, 
it  is  no  different  than  a  license  to 
own  or  operate  a  car,  truck,  gun. 
fishing  rod.  camper,  or  what- 
ever. Look  at  all  of  the  people 
out  there  that  took  a  driver's  test 
many  years  ago  in  a  car  and  go 
out  and  buy  a  big  camper,  get 
behind  the  wheel,  and  create  a 
menace  on  the  highways.  (This 
is  not  to  say  that  many  people 
don't  drive  campers  well)  i  fall 
to  see  a  big  difference.  Who 
really  cares  what  a  MOSFET 
does,  or  a  diode,  or  a  spark  plug, 
as  long  as  the  rig/car  works. 
Some  folks  would  not  know  a 
spark  plug  from  a  rotor, 

I  endorse  and  support  Mr. 
Bash,  will  use  his  services,  pro- 
vide feedback,  and  do  whatever 
else  1  can.  To  those  that  scorn 
him,  I  detect  a  note  of  jealousy 
(these  services  were  not  avail- 
able to  them)  and  a  desire  to 
maintain  some  elitist  group.  We 
should  keep  the  code  as  It  is,  but 


all  this  theory  is  for  the  people 
that  really  like  it.  Heck,  you  can 
get  a  pilot's  license  without 
knowing  how  to  fix  the  plane. 
Too  many  old  folks  reluctant  lo 
make  change  stagnate  anything 
they  are  involved  in.  Let's  wake 
up  and  revitalize  ham  radio.  Now 
is  the  time. 

Alan  Davis  KB7HM 
Salt  Lake  City 

Lef's  hear  it  for  the  code-free, 

theory-free  license- — Wayne. 


KEEP  IT  SHORT 

I  am  pieased  that  you  have 
seen  fit  to  promote  10-meter  FM 
in  73. 

As  one  who  has  been  on  29.6 
for  many  years  (at  the  tjottom  of 
the  sunspot  cycle)^  I  am  dis- 
turbed at  the  new  arrivals  on 
29.6  complaining  about  people 
who  aren't  QRP  or  running  a 
converted  CB.  (Everyone  else  is 
using  excessive  power.)  I  wel- 
come these  newcomers  and 
hope  they  will  contribute  to  the 
band.  The  fact  that  most  have 
converted  a  CB  or  old  mobile  rig 
places  them  among  the  few 
hams  who  are  not  merely  appli- 
ance operators. 

QRP  contacts  are  an  everyday 
thing  on  29,6,  but  they  are  usual- 
ly brief.  1  would  hope  that  for  the 
first  few  exchanges,  the  QRP 
operator  would  keep  it  short— 
QTH,  handle,  rig,  signal  report. 
As  exchanges  prove  the  band  is 
holding  up,  then  rag  chew-  Over 
50%  of  my  contacts  were  fading 
into  the  noise  before  1  could  get 
basic  information,  so  I  have 
stopped  calling  the  marginal 
ones. 

The  newcomers  are  probably 
not  aware  that  1  kW  and  a  5-el 
beam  on  29.6  will  provide  a  fade 
margin  for  long,  frequent  con- 
tacts  while  they  are  fading  into 
the  noise. 

Hopefully,  everyone  will  be 
able  to  coexist  on  this  small 
piece  of  10  meters.  QRP  signals 
are  great  for  studying  propaga- 
tion, and  we  all  have  tots  to 

learn. 

My  hope  is  that  some  of  these 

QRPers  will  see  the  vatue  of 

power  and  gain  before  we  hit  a 
low  in  the  sunspot  cycJe.  There 
is  a  whole  world  of  600-1  ZOO^mile 
sporadiC'E  activity  white  20/15 
meters  are  closed,  but  a  QRP 
will  be  unable  to  take  advantage 
of  It. 

Les  Whitlaker  Jr,  WBiPXA 

Miami  FL 


194     73  f{4agazine  »  December,  196Q 


2822  North  32nd  street.  #1    •    Phoenix,  Arizona  85008   •    Phone  602-956-9423  -"^ 


2N2857JAN 

2N2949 

2N29^7 
2N2950 

2N3375 

2N3553 
2N3818 

2N3866 

2N3866JAN 

2N3866JANTX 

2N3925 

2N39't8 
2N3950 

2N3959 

2N3960JANTX 

2N^072 

2Ni|i+27 

2Nlfl+29 

2N4877 

2Nif959 

2N4976 

2N5070 

2N507I 
2N5108 
2N5I09 

2N5179 
2N5583 
2N5589 
2N5590 
2N5591 

2N5635 
2N5636 

2N5637 
2N5641 

2N56i*3 
2N56i+5 

2N53W 

2N5849 

2N59^2 

2N59^6 
2N5862 
2N&080 
2N603I 
2N6032 
2N6083 

2N603't 

2N6095 
2N6096 


$   2.50 

3.60 

15.00 

it. 60 

8.00 

1.57 
5.00 

1.00 

2.50 

4.00 

10.00 
2.00 

25.00 
3.00 

10,00 
1.60 
1.10 
7.00 
1.00 
2.00 

15.00 
8.00 

15.00 
^.00 

1.50 

1.00 
i+.OO 
6.00 
8.00 
11.00 

5. Ml 
11.60 
20.00 

5.00 

li+.OO 

10.00 

8.00 

20.00 
irfl.OO 
Ift.OO 
50,00 
7.00 
10.00 
11.00 
13.00 

l^t.OO 
11.00 

20.00 


2H6097 

$23.00 

2H6166 

38.00 

2N6368 

22.99 

2N6439 

40.00 

A210/MRF517 

2.00 

BLY38 

5.00 

t*0280/2N4'f27 

1.10 

itO28l/2N3920 

7.00 

40282/2N3927 

10.43 

NE555V  TIMERS 

39c   each  or    10/$3.0Q 

NEW  DUAL  COLON  LED 

69t   each  or 

10/$5.00 

HEP170  1000  PIV 

2.5  Amps  25<  each  or 
100/$15.00 

HIGH  VOLTAGE  CAPS 
420  MFD  ^   400  VDC  OR 
600  MFD  (®  400  VDC 
$6.99  each 

MEW  ROTRON  BISCUIT  FANS 
Model  BT2AI   115  VAC 
$12.99  each ^ 

TOR  IN  TA700  FANS   NEW 

Model  A30340 

230  VAC  <?>    .73  Amps 

Will  also  work  on  115  VAC 

$29.99  each 


ORDERING  INSTRUCTIONS 

Check,  money  order,  or  credit  cards 
welcofTie,  (Mastercharge  and  VISA  only) 
No  personal  checks  or  certified  personal 
checks  for  foreign  count rys  accepted. 
Money  order  or  cashiers  check  In  U.S. 
funds  only.   Letters  of  credit  are   not 
acceptable. 

Minimum  shipping  by  UPS  is  $2-35  with 
insurance.   Please  allow  extra  shipping 
charges  for  heavy  or  long  items. 

All  parts  returned  due  to  customer  error 
will  be  subject  to  a  15X  restock  charge. 

If  we  are  out  of  an  I  tern  ordered,  we 
will  try  to  replace  it  with  an  equal  or 
better  part  unless  you  specify  not  to, 
or  we  will  back  order  the  item,  or 
refund  your  money, 

PRICES  ARE  SUBJECT  TO  CHANGE  WITHOUT 
NOTICE.   Prices  superseade  all  previously 
published.   Some  items  offered  are 
limited  to  small  quantities  and  are 
subject  to  prior  sale. 

We  now  have  a  toll  free  number  but 
we  ask  that  it  be  used  for  CHARGE  ORDERS 
ONLY.   If  you  have  any  questions  please 
use  our  other  number.   We  are  open  from 
8:00  a.m.  -  5:00  p.m,  Monday  thru  Saturday, 

Our  toll  free  number  for  orders  only 
is  800-528-3611, 


DOOR  KNOB  CAPS 
470  pf  ^  15  KV 
Dual  500  pf  t®  15 
680  pf  @)  6  KV 
800  pf  (©  15  KV 
1000  pf  ^  20  KV 
270Q  pf  ^  40  KV 


JUMBO  LEO'S 
Red 

Clear 
Yel low 
Green 
Amber 


8/$ 1,00 
6/$1.00 
6/$ 1.00 
6/$ 1.00 
6/51.00 


MEDIUM  LED's 
Red  6/$1.00 
Green  6/$ 1,00 


$3.99  each 

KV   5-99  each 

3,99  each 

3.99  each 

5.00  each 

5.99  each 


NEW  G-E.  OPTO  COUPLERS  kUlS 
69c  each  or  10/$5.00 


NEW  &  USED  BCD  SWITCHES 
3  switch  with  end  plates 
New  $8.99 
Used  $6*95 


HICRO-HINI    WATCH   CRYSTALS 

32.768  H2        $3.00  each 

—       —     —        -1-^  ■  -  —  —  —  

NEW  2    inch   ROUND   SPEAKERS 
100     Ohm  coi  1 99<   each 

PLASTIC  TO-3  SOCKETS        V$1.00 


NO   ORDERS   UNDER  $10 


t^  Reader  Ssfvtce—s&^  page  22G 


73  Magazine  •  December,  1980     195 


on 

Scanners! 

NEW  Rebates! 

Communications    Electronics^    the 

world's  largest  distributor  of  radio  scan- 
ners, celebrates  Christmas  early  with  big 
savings  on  Bearcat  synthesized  scanners. 
Electra  Company,  the  manufacturers  of 
Bearcat  brand  scanners  is  offering  con- 
sumer rebates  on  their  fantastic  line  of 
crystaifess  scanners  purchased  between 
September  15  and  November  15,  1980. 
We  give  you  excellent  service  because  CE 
distributes  more  scanners  worldwide  than 
anyone  else.  Our  warehouse  facilities  are 
equipped  to  process  thousands  of  scanner 
orders  eve  ry  week  We  also  export  scan  ne  rs 
to  over  300  countries  and  military  instal- 
lations. Most  items  are  in  stock  for  quick 
shipment.  Do  your  Cliristmas  scanner  shop- 
ping early  and  order  today  from  CE! 

BearcatfSOO 

The  Uitimaie  Synthesixeti  Scanner! 

List  price  S5t9^5/CE  price  $329.0O/$20.00  rebate 
Your  final  cost  is  a  low  $309.00 
4-6an(if  SO  Chanrs&i  •  Service  Search  »  No- 
crystal  scanner  «  AM  Aircraft  and  Public 
Service  bands,  •  Priority  Channel  *  AC/OC 
Bands:  32-50.  118-136  AM,  144^174,421-5^2  MHi. 
The  new  Bearcat  300  is  the  most  advanced  aulo- 
matte  scanning  radio  ttiat  has  ever  been  offered  to 
the  public-  The  Bearcat  300  uses  a  bnght  green 
fluorescent  digital  disptay,  so  it's  ideaf  tor  mobile 
applications.  The  Bearcat  300  now  has  these 
added  features;  Service  Search,  Oispiay  ^ntensitv 
Controi,  Hold  Search  and  Resume  Search  keys, 
Separate  Band  keys  to  permit  took- ir/Eock- out  of 
any  band  for  tnore  efMciant  servtce  search, 

Bearcat®  250 

Ust  pnce  S419  95,  CE  price  S259.O0/S20.O0  rebate 
Your  final  cost  is  a  low  S239.00 
SO  Channels  *  Crystaliess  *  Searches 
Stores  •  R0Q0IIS  •  Digital  clock  •  AC/ DC 
Priority  Channel  m  3-Saftcf  •  Count  Feature. 
FreQuency  range  32-50,  146-174,  420-512  MHz. 
The  Bearcat  250  pertorms  any  scanning  function  you 
could  possibly  want.  With  push  button  ease  you  can 
pmgram  lip  to  50  channels  for  automatic  monitoring. 
Overseas  customers  should  order  the  0e area f  250 FB 
at  $349.00  each.  This  model  is  (Ike  a  Bearcat  250.  but 
deslgnedfor  internati^onalopei-ation  wfth220VAC/1  2  V 
DC  power  supply  and  66-88  MHz  low  band  coverage 
Instead  of  32-50  MHz. 

Bearcat®  220 

List  price  $41 9  95/CE  price  S2 59.00/820. DO  rebate 
Your  final  cost  is  a  low  S239,00 
AircrsH  af%d  puMic  service  mortft&r,  Frequ^r^cy 
ra^ge  32-50,   nB-'i36AM,   144- J  74,  420-512  MHl. 
The  Bearcat  220  Is  one  scanner  which  can  monitor  all 
public  service  bands  plus  the  eKciting  AM  aircraft  band 
channels.  Up  to  twenty  frequencies  may  be  scann  ed  at 
the  same  time.  Overseas  customers  should  order  the 
Searcar  220FB  at  S349.00  each.  This  model  is  like  a 
Bearcat  220,  but  designed  for  international  operation 
with  220  V  AC/1 2  V  OC  power  supply  and  66-88  MHz 
low  band  coverage  instead  of  32-50  MHz. 

NEW/ Bearcat®  21 OXL 

List  price  $319.95/CE  price  $2Q9.0O/$20.00  rebate 

Your  final  cost  is  a  lows  189,00 

is  Channets  *  3  Band^  *  Crystatless  *  AC/ DC 

Fr&quertcy  rang&:  32  50.  U4-174,  421-512  MHz. 
The  Searcaf  2 1 0XL  scanning  radio  is  the  second  gener- 
ation scanner  that  replaces  the  popular  BearcAi  210 
and  211.  tt  has  almost  twjce  the  scanning  capacity  of 
the  Searcar  210  with  18  channels  plus  dual  scanning 
speeds  and  a  bright  green  lluorescent  display. 


NEW!  50-Channel  Bearcat  300 


FItEE  Bearcat®  Rebate  Offer 

Gel  a  coupon  good  for  a  $2Q  rebate  when  ycu  purchase  a 
8^arc3i  300,  250,  220  or  2 1 0XL.  $  1 0  rebate  on  models  211, 
210  and  l60,Toget  your  retaate,  mail  this  coupon  with  your 
original  dated  sales  receipt  ^nd  the  Saarcaf  moctel  rmmber 
frorrt  the  carton  to  Eiectra  Vou'lt  receive  your  rebate  in  four 
to  SIX  weeks.  Otter  valid  only  on  purchases  made  belwen 
September  1:5,  1 980  and  November  1 S,  1 980.  AU  requesta 
mus-t  be  postmgrKs-d  by  Movem&er  29,  19S0-.  Limit  of  one 
re-bate  per  housetioJd.  Coupon  musl  accompany  all  rebate 
requests  and  may  not  be  reproduced.  Offer  good  only  In  the 
U.S.A.  Void  where  taxed  or  protiibited  by  law.  Resellers, 
companies,  clubs  and  organ  i^arionsHaoth  profit  a  net  non- 
profit-are  not  eHgfcble  for  rebatet.  Employees  of  Etectra 
Company^  thair  advertssing  agencieSf  distributors  and  re- 
tailers of  Bearcaf  Scanners  are  atso  not  eligible  for  rebates. 
Please  toe  sure  to  send  in  the  correct  amount  for  your 
scanner.  Pay  the  fisied  C  E  price  in  rhis  ad.  Do  not  deduct  the 
rebate  ampunt  since  your  rebate  w^li  be  sent  directly  to  you 
from  Electra.  Orders  received  wtth  tnsufricleni  payments  wj  1 1 
not  be  proces-'Sed  and  will  be  returned. 

NEWl  Bearcat®  1 60 

List  price  $279.95/CE  price  $1 89,00/S1 0.00  rebate 
Your  f  inat  cost  is  a  low  $1 79^00 
f  6  Channels  •  J  Bands  «  AC  only  •  Priority 
Quel  Scan  Speeds  •  Direct  Channel  Access 

Frequency  range:  32  50,  144-174.  440-512  MHz. 
The  Bearcaf  1 60  presents  a  new  dimension  (n  scanning 
tofin  and  Junction .  The  keyboard  Js  snnooth,  No  buttons 
to  punch.  No  knobs  to  turn.  Instead,  finger-tip  pads 
provide-  control  of  aU  scanning  operations,  including 
On/Oft  Volume  and  Squelch.  Green  easy  to  read 
fluorescent  display. 

HEWl  Bearcat^  5/800  MHz 

Tho  world's  first  600  MHx.  scanner! 

Th}S(sanew  modet  Sf}\pmBnt^  wHi  begin  in  Decemb&r  1930. 

List  price  $1  79.95/CE  price  $1  29-00 

0  Crystal  ChennefB  *  4  Bands  m  AC  only 

Fmqu&ncy  r^ng^:  33-50,  144-1/4,  440-5  S  2,  306-870  MHz. 
The  Bearcat  5/800  MHz  is  the  only  scanner  on  the 
market  today  that  offers  coverage  of  the  800  MHz. 
public  service  band  and  the  other  public  service  bands. 
IndivJduat  channel  lockouK  Scan  De^ay.  Manual  Scan. 

Bearcat^  5 

List  price  $129.95/CE  price  $89.00 

#  Crystal  Channels  *  3  Bands  •AC  only 

Frequency  range:  33  50.  146  174.  450-508  MHz. 
The  Bearcats  isa  value- packed  crystal  scanner  tjuilt  for 
th©  scanning  professional  —  at  a  price  the  first-time 

buyer  can  afford.  Individual  lockout  switches. 

Bearcat^  Four-Six  ThinScan™ 

List  price  5179.95/CE  price  $114.00 
Frequency  range:  33-47,  152-164,  450-503  MHlL 
The  incredible,  new  Bearcat  Four-SixThin  Scan"  is  like 
having  an  information  center  rn  your  pocket.  This  three 
band,  6  channel  crystal  con  trolled  scanner  has  patented 
TrackTuning  on  UHF.  Scan  Delay  and  Channel  Lockout. 
Measures  2^/i  x  6Vi  x  T:'  Includes  rubbef  ducky  antenna. 
Order  crystals  for  each  channel,  Made  in  Japan. 

NEWS  Fanon  SlimllrTe  6-HLU 

List  price  Sl6a95/CE  price  $109.00 
Low  cost  6-channelf  3''band  scanner! 

The  new  Fanoti  Slimline  6-HLU  gives  you  six  channels 
of  crystal  controlled  excitemerit  Unique  Automatic 
Peak  Tuning  Circuit  adiusts  the  receiver  front  end  for 
maximum  sensitivity  across  the  entire  UHF  band,  indi- 
vidual channel  lockout  switches.  Frequency  range  30-50, 
146-175  ar^d  450-512  MHz.  Sfcze2^  ^SVj  x  ir  Includes 
ru  bber  d  ucky  a  n  t  en  n  a.  O  rde  r  crystal  cert  if  icates  f  o  reach 
channel.  Made  in  Japan. 

NEW!  Fanon  Slimline  6-HL 

List  pnce  $  1 49.95/CE  price  S99.O0 
6-Channel  performance  at  4-channel  cost! 

Frequency  range:  30-50.  146-1  75  MHz. 
If  you  don '?  need  the  UHF  band,  get  this  model  and  save 
money.  Same  high  performance  and  features  as  the 
model  HLU  without  the  UHF  band.  Order  crystal  certifi- 
cates for  each  channel,  f^ade  in  Japan. 

FAHOH  SCAHHER  ACCMSSORtES 

CHB'6  AC  Adapter/ Battery  Cfiarger St 5,00 

CAT-9  Carr ying  cas*  for  Fanon  w/Be(t  Clip S 1  5.00 

AUD3  Auto  lighter  adaptor/Battery  Chargm SI  5.00 

OTHER  SCANNER  ACCESSORiEB 

SPSO  AC  Adapter    ...,..■..,... , ., S9.00 

SP51  Baitery  Charger. . . .   sa.OO 

S Pse  C arf y i  n g  Case  For  Beared f  4 -6  Th j m S ca n"      .$12.00 

FQ-E  Frequency  Directory  for  Eastern  U.S. A SI  2.00 

f  8-W  Frequency  Directory  for  WS'St^rn  U.S.A.  . .     .  Si  2,00 

FFD  Federal  Frequency  Okectorv  for  U  S.A S1  2.00 

B'4  1  .i?  V  AAA  Ni-Cad's  for  ThinScan"  and  Fanon  , , . $9.00 

A-135CC  Crystal  certificate ,.S3.00 

Add  $3.00  shipping  for  all  aoceEsones  ordered  at  the  same  time, 

INCREASED  PERFORMANCE  ANTENNAS 

ff  you  want  the  utniost  in  performance  from  your 
scanner,  it  isessential  that  you  use  an  e)tterr>ai  antenna. 
We  have  six  base  and  mobile  antennas  specifically 
designed  for  receiving  all  bands.  Order  #A60  is  a 
magnet  mount  mobile  antenna.  Order  #A61  is  a  gutter 
clip  mobile  antenna.  Order  #A62  is  a  trunK-lip  mobile 
antenna.  Order  #A63  is  a  ^k  inch  hole  mount  Order 
#A64  isa  %  Inch  snap-in  mount,  and#A70  isan  all  band 
base  station  antenria.  All  antennas  are  $30.00  and 
$3  00  for  UPS  shipping  in  the  continental  United  States, 

TEST  ANY  SCANNER 

Teal  any  scanner  purchased  (rom  Communications 
Electronics'^  for  31  days  before  you  decide  to  keep  it.  It  for 
any  reason  you  are  rot  completely  satisfied,  retuin  it  in 
original  conditi-on  with  all  p3rt$  in  31  days,  for  a  prompt 
refund  (less  shipping/ handling  charges  and  rebate  credits). 


MEWfRegency^i  M400 

List  price  S379,96/CE  price  $2S9.00 
30  Chanrtei  •  Synthesized  •  Service  Search 
Digital  clock  *  Disit»l  timer  *  MiDO  styling 
Search/Store  •  Priariiy  Channel  •  AC/OC 

Frequency  range:  30-50.  144-174,  440-512  MHz, 
The  new  Regency  IVI400  is  a  compact  programmable 

FM  monitor  receiver  for  use  at  home  oron  the  road, 

OTHER  REGENCY'    SCANNERS 

Touch  K1 00  , ....  $  1  99.00 

Touch  Ml  00 « 199,00 

NEW!  Telephone  Products 

Electra's  cordless  freedom  Phone  does  everything 
an  ordinary  phone  does  and  more.  Because  it  iscordJesSf 
you  can  take  it  anywhere,  fnaide  or  outside—on  the 
patio,  by  the  pool,  in  the  garage,  in  the  workshop„.&ven 
next  door  at  the  neighbor's,' 

Model  FF»5O0  has  pushbutton  dialing.  Rechargeable 
ni'cad  batteries  included.  Battery  low  light.  Secure 
feature,  Telescopic  antenna.  Your  cost  is  S1 79,00. 
Model  FF-1500  has  the  same  features  as  the  FF'500 
but  also  includes  a  charger/cradie  that  allows  the 
phone's  handset  10  be  recharged  away  from  the  base 
station.  Your  cost  for  this  cordless  phone  is  Si  99.00. 
The  model  FF-30O0  has  all  the  standard  features 
{except  charger/cradle}  plus  interchangeable  telescop- 
ic and  rubber  ducky  antenna.  Redial  feature.  Belt  Clip- 
Carrying  case.  Greater  range.  Your  cost  is  S229.00. 

World  Scsnner  Association" 

The  WORLD  SCANNER  ASSOCIATION  is  sponsored 
as  a  public  serv^ce  by  Communtcatlons  Electronicrsr 
When  you  join,  you'll  receive  a  one-year  membership 
and  our  quarterly  newsletter  with  scanner  news  and 
features.  You'N  also  get  a  waltet  C.D.  card,  an  Officia] 
WSA  Membership  Certificate,  and  more.  FREE  clasai- 
f  led  ads  for  members  so  you  can  contact  other  scanner 
owners  when  you  want  to  sell  or  buy  a  scanner.  FREE 
membership  in  the  WSA  Buyer's  Co-op,  Your  Co-op 
membership  will  allow  you  to  get  special  discounts  on 
scanners  and  scanner  related  products.  SrncetheWSA 
Buyer's  Co-op  gives  you  group  purchasing  power,  you 
can  easily  pay  for  your  membership  dues  the  first  time 
you  make  a  Co-op  purchase.  To  join,  send  $12.00 
t$20.0O  outside  U.S.A.)  for  your  membership  materials. 

BUY  WITH  CONFIDENCE 

To  g&t  th^  fastest  d^ffvory  from  CE  ol  any  scanner,  s&nd 

or  phone  your  order  direcliy  to  qui  Scann gr  Distribution 
Center!"  Be  sure  to  c^lcutate  your  price  using  the  CE  prices 
in  this  ad.  Michigan  residents  please  add  4%  sales  tax. 
Written  purchase  orders  are  accepted  from  approved  govr 
ernment  agencies  and  most  well  rated  fkms  at  a  10% 
surch-arge  for  net  30  bLJIing.  All  sales  are  subject  toavalit- 
biliry,  AN  sales  on  accessories  are  linaf.  Prices,  terms  and 
specif rcat ions  are  subject  to  change  without  notice.  Out  of 
stoc  k  ite  ms  w  i  [1  be  placed  o  n  bac  karder  au  tomatically  u  rriess 
CE  is  instructed  differently  Most  products  that  we  sell  have 
a  manufacturer's  warranty.  Fr$e  copFes  of  warranttres  on 
these  products  are  availatale  prior  to  purchase  by  writing  to 
CE,  lnternal^onal  orders  are  invited  with  aS20.00  surcharge 
for  special  handling  in  addition  to  shipping  charges.  All 
shipments  are  F.O.B.  Ann  Arbor,  Michigan.  No  COO's 
please  Non-cedified  and  foreign  checksreciu  ire  five  weeks 
bank  clearance. 

Mall  orders  to:  Communications  Eiectronics" 

Box  1002,  Ann  Arbor,  Michigan  48106  U.S.A.  Add 
S6.00  per  scanner  or  phone  product  for  IJ,P,S. 
ground  shipping,  of  $12,00  for  faster  U.P.S.  air 
shipping  to  some  locations  If  you  have  a  Master 
Charge  or  Visa  card,  you  may  call  anytime  and 
place  a  credit  card  order.  Order  toll  free  in  the  Li.S,  A. 
800-521-4414.  If  you  are  outside  the  U.S.  or  in 
IVIichigan,  dial  313-994-4444.  Dealer  inquiries 
invited.  All  order  lines  at  Communications 
Electronics'^  are  staffed  24  hours. 

WSAr  Scanner  Distribution  Center"  and  CE  logos  are 

trademarks  of  Communications  Electronics!* 

f  Bearcat  and  freedom  Phone  are  federally  registered 

trademarks  of  Electra  Company,  a  Division  ot  Masco 

Corporation  of  Indiana. 

t  Regericy  is  a  federally  registered  trademark  of  Regency 

Eiectronics  Inc. 

Copyright   1 980  Communications  Electronics'" 


TM 


1^377 


COMMUNICATIONS 
ELECTRONICS™ 

854  PhQ9mj<  Q  Bex  t002  G  Ann  Artor,  Michigan  4fllOB  U-S.A, 
Cil  I  TOLL-  FRE  E  t  ftOO)  S2 1  44 1 4  qr  out>ld«  U,  5 .  A.  1 31 3)  »»4'4444 

We're  first 
with  the  bestT 


t^eo 


ELECTRONICS 


INTEGRATED  CIRCUITS 


P.O.  Box  443aM 
Santa  Clara,  CA  95D54 

Will  calls:  2322  Walsh  Ave. 

(4o@)  gaa~i64o 

Sam«dav  shipment.  Flr^tflhe  (>arts  orriy    Factory  tested 
Guarantflfid  monEy  back.  QuaiitylC'&anii  other  compo- 
n&nts  at  lac  lory  prices. 


mam 

7i\4H 
7<Z?fC 

■M4m 
74im 
mm 

7*7iH 
7*?5N 

jimN 

7492N 
?J'J3N 

74U5M 

741^dM 
7J157N 

74162N 
74H3IH 
74irqN 
741 75N 
■WMN 

;41S3h 

7fiZS6(v 
7*31^ 

rMgTN 

74tSOa  tTL 
7i;  tJIlM 
7.1i!J0iN 
741  H5*N 

7ilSg[m 

74i511N 

;4i  K*][h! 

"4t^2.aN 
74i  SlWW 

74[.5'SaN 

J4i:&7SJJ 
?4tS»t( 
74L293H 

7<iLSID7itJ 
74LSr1?N 

74LS^3?N 
7iigiMlN 

74iS-363N 
7iJLi1&3N 
74Li1?4N 
74L^SS0N 
7aLSil?IN 
7<I,S5» 
7*LS3fir*l 

UHEAn 

CAJ[f46 
CA3(H1 

CKom 

I  ^IICllAiuAH 
LMJOSH 
I  U307JJ 

i  vr    -ti 
iw.i-nK 
Lr,J3LS 
LU3?DK-5 


3S 


5.9i 
I  BO 
I  !H1 
I  3l] 
1.35 
I  3& 


fl< 


LM32iK  !i 

Lr«32DK 

|H-3;iOff  iS 

LM.3ZD7-5 

LH3gOTS 

LW32CiM? 

IM-3JPT-15 

LMi33S«l 
I  tA^m  $ 
Lfpfta4Cl!-tt 

d.M^[I>|(:-:!4 
.LW34CT-S 

imnii  1? 

LM34D7-15 
LWJCT.m 

Lht34D^^<4 
^M3ai 

LM703H 

I  M7flS|H 

LMi'23H.M 

LM7J3N 

tM7^1CH 

LM7<IN 

LM7<7M.hl 

L«74flH 

LMI])34 

UMisor' 

LUf211l 

LMtS12 
L4il84S 

LM3BDh 

Lsl39Wh 

MtUSEV 

Nt35BA 

HE5«V 
MESS?V 
NE&7flB 

raJlE. 

7±1!1B 

7i4HKN 
Z&flWCN 


jt  m  D  i^DNViRTf n 


fl7Gcrj 

g4i»CJVif 
ici7ia3 

CMQS 

i:DJd&[i 

£04002 
Cn4D0£i 
CD*O0.' 
CP40i]S 
CD+DDH- 
CD4«1D 
CD40n 
CD4ei3 
CP4£113 
CD40U 
CD4(}IS 
0D4OI& 

i:;D4aiJ 
cri4oie, 

cs4a?3 

CO40?4 
C£i4(H!i 


4  50 

7.*a 

14.34 


c;a4dj7 

CD  j4  1123 

CP4(I4D 
C:[l404^ 
CD  4043 

cg4g44 

CD404g 
CD4fl5& 
CD40ar 
c:p4<WD 

CD40GE 

CDJOse 
(^04ati^ 

CD40?9 

atom 
c\ita7j 

C:D4i)?3 
CD4Q7& 
CD40'6 

cp4aze. 

eD4oa? 
r:n4iifi. 

D-D4Sg? 

C04}aft 

DP  4511 
GC4iiE 

i:D451fl 

(704527 
C04538 

EC4SaQ 
M45S3 
C£i4Seb 

cp4:^ig? 

74C:(M 

74(;!a 

?4C'4 

74i:;aci 

74CM 
74C43 
]f4C?4 

74dre 

74C(H3 
J'4C93: 
74C1fi.fi 
74CLBD 
7C17i 
74GlS« 
7Ca?1 
74C9(B 
T4CSQfi 
74c;mi 

;4C;aEZ 
7iCMTTi 
74CflH 

74[:g;fc 
•74C927 

WTfSF*CE 

SC96 
8897 
809S 

STffi! 

iSTIO 
&TI5 
Sl2l> 
ST23- 

m+ 

at25 

BT2& 
BT97 


?1Q1   ■  P 
fl4J2-1 

2iij?;^L-4  1 

^iDfflNJL  1 

Si{14*-4  4 

■211]7fl-4  3 

?11t-1  3 

2112-^  3 


4^6  JOOns  ?.95 
B.41>6Ki&« -491:00 

t^M529D  3  DO 

UM53-FJ  5  9* 

PC?.a1  !5  ?  4  M 

P041  "ff  J  S  00 

psmit  a  56 

42K1A  S'St.-i 

s2S?s.  ?.aa 

9ll.0?A  t  So 

1MM57inn:  4  ^ 

53*8  S.50 

410O  m.w 

4ii-  liM 


COHNECrDnS 

50  pin  eiw         E  feO 

ifi  liili  ed^  ?  7i 

1  Of  on  fulpu         4  M 

100  or  ii^E  WW  b  i'j 

S«ld#rTin  Latw  Pr«1lle 


GljOC^CI 

Mhib334 
MM53Sg 

crwhO 

CT7a^& 

HPi5J7iAiVW 

MMSa74ftGiP( 

7305 

7387 

7J0? 

OSOOEecIN 
DSDObUCh 
WM5SfDf 


•3.8ft 
£10 

f4.^5 
7.95 

!9& 
3.90 
4.90 
IS.5D 
7.50 

.4  95 
S.75 
iTS 
2^50 


MFHjlitopnDCESsfln 


I  7t 


g5C4 
6522 
bBCO 

eB2e 

^B50 

soeeA 

90  Ob 

zao 

S5I2. 
SZt4' 
351-6 

^J# 

S25» 

S£53 

■SS5b 

HE7 

&2fiS 

"gOSKPplgj   13.9.5 

iM2t!P(*ag  n-% 

dDl^'!S)3D 
CDP''S6f 


•0.9!i 
9.95 
9  55 

M.gs 
4.95 

7L.O0 

9  95 
2.% 

.^.93 

2.W 
5;4i 
4S5 
B.95 

&75 
Hf.9S 
1.1  an 


l!.50 
26  9F. 
3sau 

1^9  E. 


AY5-iai3  3 

Aij  1(14  I 

I ro2ft  4  » 

filJU  noDHr  CJiwfl  7 

270a  7.75 

?7i6Ti  raoo 

E^i3715  Iftlel  TfiO.'Oa 


2-75B 
6^    ■«.74TA 
B746: 
a745-fl 
R*MJ?5SA 
R5     Na.2S23 
90     NB2SI23 
>4     NEi'5i1S6 
IEI{]     Nft5&l2» 
95    hlB.?Eint 
7b    NB.?&i3Bi 
75     MBSR137 
55     UWa57? 
75    a325 


2?.5B 
I^OD 
Sb.OB 
BJI.eiB 

2  95 
Ei.iB 
3.75 
B.^B 

»$n 

B.75 
8:75 
?.ia 


i  lM«f  !■*  nni  **    .^1' 
Wtn:E  WRAP  LtVEL  3 

m         m 

14       .32-     34        M 

It      33'    2a    l.aB: 
tB    .:S7    ie    1.JS 

I  Mtlz  4.50 

?  Mii.'  4.59 

^  M-;-  4  K 

5MHJ  4.J5 

l&MHE  4  5& 

1.0  WH;  3.90 

30  MH;  3.90 

32MHi  3.90 

337&a  Hj  4.gfl 

1  S4J7  MMj  4  50 

3:S7SSWHT  i.M 

SOIHlJyiHl  1.95 

?  OH7152  MUf  4  Sfl 

2'.45'.'b  mHi  4  iO 

3  £764  MH.'  4 .50 

^  050$  MH^  4  ^ 

&.105  MHr  4.60 

5. 714 J  MH J  4  50 

O.SiSG'MH?  4  &0 

r-iSiHlBMHj  4  a 

tS  -63?  MM/  4.50 

22  )1&4  Whi-:  4  5» 

IK'^BtMUlD  ENCDDEf^S 

ilY;.J3Vfi  SI?5Q 

AV6-3B00  17  05 

Arj91[X]  1D5D 

Aft92lX)  l&.M 

74C;K!2  &  SO 

74C-923  5.50 

HDdlES-a  i.^ 

AT2iS4lXJ  Ittfifl 

D  CUllMIICtv^  HSW 
QEI2iP  J  6? 

DBJ5S  5  20 

Cn(^er  1.67 

ftniip  ?.ia 

CiHmplHtia  ^  9  ^ 

Hlthal3I^I]HBMLEDmul' 
tirtiBlu  74^5 

S.1Apa31£h  Nil  21  3% 

ll4lliSi  CI^CL  Jtlt  17^5. 

DlikilAl  Clfti  nt      14  99i 

in-  lU  f  ipum  Kll 

MalhlitVPird  tSa^lO 

EtlAi^dBr  Bblfd      ^15  40 

ltE5IST0H^  U  ^S\['i'\ 
'P  UP  IjiIH!   03 
i  ■  35  [«M  r^Ht   025 
ion  iicr  Ivpii   ns5 
lOOOilE:!  [>■»   ai-2  : 
n^  pbx  p^k 
5  par  lv[»  e  7$ 

4^«tr.iS  per  tyjiB  :Jl!!t 

falni^ED  r«rnila«F 
4llai$t<^l2       Si&4b  00 
Uudft  9211        I945-DD 

lliif  EpjlLi^artninrfin  Ht 


KETBQAflDS 

!:&  Nsjf  i^SCl  I  ItivtMard  til  SS7.4* 

l-iill^  iSfiEmibiM  77  M 

53liOSi  flSCil  Ktv&gttfdairj  60  Ofl 

Fullv  jfl^BIPPlEd  to  OB 

FndUi>Jn»?l«F.1iL  14  at 

M«Bi  LnclD^una  ^  a& 

fled  TO  I  ft  .1* 

[dreen  VtilM  IQia  .30 

JUF-tip  fla(t  HI 

Grft^i'i  i)iinge  IrtOc*  Jnrnhn        ?5 
CI|pli1*LCDMQuni|ntCiip3    g.t1  25 

ISfeCt,  f^il.  iiiihe:.  ijrasi'    j-aiflw  ClMr'i 

CDNTiNEHTKL  SFEEIALriEB  In  ElDCk 
r^'iii  u'l't'i;  I  If-  'i'l  I'  !n:ii^':i^i{l  Itl.l  mi|li? 
MAX- hM  B  digit  Frsq.  Ctr.     I1EB.I5 

QK  WIRE  WftAP  TDDL^  le  uatt 
Ptariabli  HulllDitMr  SIS-H 

Ljmplsit  hng  a1  flf  P'MucH  ■•'1  sioet 

SPECIAL  pnaoueTS 

Wlln  10  K    31H1C  9.00 

sH^Dpara  7. 50 

SwIKh!^  MLtii    PushbullDIi  37 

'!  pPE.    Jlid?  2b 

En»riAr  HOOIliS-'!  i^  95. 
farsirpn^s  iSDA  Lngtic: 

MiiPtI  10  li>gL|iii 

Fapgrviicr  Kif  S??9  Ofl 

UQdQl  IS^  li'ilS 

Orabl)«'  Kh  tJEn  DO 

C:i49[A  Calpndir  ){il  £23  SS 

1.5  MiKi  Fr«4uaii«V 

{iDunbtr  .<il  137.50 

3B  HHlE  Frequfl'cv 

CihuhterCia  147.75 

TnANSFOflMrRS 

12  Vfltl  ■H>U  ma  ligrsfnrmiH    1  31i 

i;  fiv  r.7  fino  mh  4  a. 

i^V  2U& -Tia  *v3il  nii^  3.!tt 

W  D7  250  ma  irall  piiuQ  J.^ 

54V  tT  4(30  ■niM  3  95 

10V  I  ?  air:ri  «^ll  PH«a  4.S5 

12^  6  dIFli  17.95 

1?V  tiOQ  iiy  itiV^tifi  4  7^ 

I2v  r  amp  wjN  piufl  e  50 
1ft!SWCflflBVA-*all(Kufl.3;i 


CA 
CC 

(iftCA 
CC 
CA 

CA-iX 

CC 
CC 

ee.'(i^ 

CGCA 
i.tlEirCf 


OISPUY  LESS 

MAN:- 

MAN3. 

MAM7;-74 

DLfO* 

017D7..D1.7(J7R 

■:■■?■  ?ZB 
.■:i^jr?5a 

fND359 
*N55im'507 
fH05llJ5lS 
FNDaoa'BOJ 
3««il  BubCito 
4  droll  iubeito 

C&g  FbiJijristntia 
Q&l  l>  F"P<KUE,G*!T1 

10  dipit  (^.iol^ 
75?[K;i««an  phol&ttlls 
niJl  I  Hex 

IMAIf3^D  C:C 

MAM46m  CA 

MAN4640  CC 

MAhi4,nO  CA 

MAM474D  CC 

MAhlB^fO  DC 

wmTMy  -CA 

hMNE7J[)  CC 

MA1DII2E 

HAT012A 

1tl!<'3  bpn?1gnii|i 

ilAi.015rt  Trinihirmr 


270  2  90 
I3S     ^y 

am?  7  oc,i 

3D0  '  25 

JDO  I  Oa 

■SOU  !.90 

&3P  I  ?S 

eao  r  (ft 

357  70 

i»  I  K 

i^O  3.20 
,60 


B-SR  CDPlmJtsr  S39.95 

tMrcr!v:ui  :iir'pu!:i  LiliuftSlHStitUilillKJ 
S^sbK    QmVUlEr  {D-.^L4lc(!  l4D^Qrpi-  VMM 
■tilUi  »i  inir  9SH:  Sat|*4r!  m  130?  lim 


PROM  Eraser 

asseoibl&d  ? 5  PROM  capacity  S37.M 
[wm  timer  S69.5D).  6  PROM  capacity  OSHA,'' 
UL  version-  SGS.SQ  (with  timer  iM.SO). 

zao  Microcomputer 

IB  bil  \m.  2  m\2  cfocJ(.  2K  RAM,  ROM  Bread- 
board space.  Excellent  for  contrpi.  Bare  Board 
$2B.5a.  Full  Kit  $99.00.  Mooltor  £20.00,  Power 
Supply  Kit  S35JD.  Tiny  Oastc  $311.00 

S'100  Computer  Boards 

8K  Static  Gpdhout  Econo  IIA  Kit  145.00 

1 6K  Static  Godboor  Econo  XIV  Kit  2B5.0Q 
24K  Static GodbDut  EcortDVIIA-24  Kit  435.00 

32K  Static  6odt)oul  Econo  X-32  Kit  575.00 

16K  Dynamic  RAM  Kit  199.00 

32K  Dynamtc  RAM  Kit  310.Q0 

64K  Dynamic  RAW  Kit  470.00 

Video  Interface  Kfl  S135.00 

60 IC  Update  Master  Manual  $55.00 

Comp.  iCdata  selector.  2/00  pg.  master  reference 
guide.  Over  51 .000  cross  references.  Free  updates 
service  flirough  1980.  Domesttc  posiaQe  S3.50 

Modem  Kit  $60.00 

StatD  ^)f  the  art.  orig  .  answer.  No  tuning  neces- 
sary, t03  compatible  300  baud,  inexpensive 
acoustic  coupler  pla/is  included 

LRC  7000 + Printer  S389. DO 

40/20  column  dot  matrix  mpad.  std.  paper. 
interface  all  peraofiaE  computers. 

64-'40.'^2,'£0  version  S4D5.0D.  Optfonai  (tables 
available. 

LRC  7000  printer  intertace  caMe  for  Super  Elf 
with  spftwar^  S2S.0Q 


NiCad  Battery  Fixer/Charger  Kit 

opens  shorted  cells  ihat  won't  hold  a  charge 
and  then  charges  them  up,  alf  m  one  kit  w,1ull 
parts  ar^d  i  nstruction  s .  $7.25 

Rockwell  AIM  65  Camputer 

6502  based  single  board  with  lull  ASCII  keyboard 
and  30  column  thennaf  printer.  20  char,  alphanu- 
meric display.  ROM  monitor,  fully  expandable. 
S375.M.  4K  version  $450.00  4K  Assembler 
$55.00.  SK  Basse  interpreter  $100.00. 

Special  small  power  sufjpiy  (or  AIM65  a&sem.  in 
frame  SS4.0Q^  Ccimpf?te  AIM65  in  thio  briefcase 
with  power  auppty  $499.00.  Molded  plastic 
enclosure  to  fit  i^oth  AIM65  and  power  supply 
$47.50.  SpeCLai  PackagR  Pnra:  4K  AtM.  3K  flasic. 
power  supply  cabinet  S599.D0 

AIM65.''KiM.'VIM,-SupBr  EJf  44  pin  expansion 
board,  3  femalu  and  i  male  bus.  Board  pius  3 
connectors  S22.95. 

60  H;^  Crystal  Time  Base  Kit  $4.40 

Converts  digital  ciocks  from  AC  line  frequency 
to  crystal  time  base.  Outstanding  accuracy 

Video  Modulator  Kit  $0.95 

Convert  TV  set  mto  a  high  quality  monitor  w/o 
affecting  usage.  Ctjmp.  kit  w^tull  instruc 

Multi-volt  Computer  Power  Supply 

8v  Samp,  ±l8v  .Samp,  5v  1.5  amp,  -5v 
.5  amp,  12v  .5  amp,  12voptton  -5v.  ±l2v 
are  regulated.  Basic  Kit  SE9,95.  Kit  witJi  chassis 
and  all  hardware  $43.95.  Add  ^.  00  shipping  Kit 
of  hardware  $14.00.  Wood  gram  case  $10.00. 
31,50  shipping. 


fi^^ 


-^^^^^^ 


lutrsspii 


RCA  Cosmac  1802  Super  Elf  Computer  $106.95 

ptus  loail,  resd.  run,  wait,  input,  memory  pro- 


Compare  features  before  you  deci(ie  to  buy  any 
other  computer.  Ttvere  is  no  other  computer  on 
the  market  to^tay  that  has  all  thp  desirahie  bene- 
i its  of  the  Super  £11  for  so  litli&  money  The  Super 
Eff  is  a  small  single  board  computer  that  does 
many  big  ftiings.  It  is  an  excellent  computer  for 
training  and  for  learning  programming  with  its 
machine  language  and  yet  il  is  easily  eipaniled 
with  additional  memory.  Full  Basic,  ASCiJ 
Keyboards,  vi^eo  character  gensr^tiDii,  etc. 

Bel  ore  you  buy  annttier  smalt  computer,  see  if  ft 
includes  the  following  tealyres.  ROM  monilor; 
Stale  and  Mode  displays:  Single  step.  Optional 
address  displays  Pov^erSupply;  Audio  Amplifier 
and  SpeaJ(ef  Fully  socketed  for  all  iC's;  Rea.!  cost 
ul  in  warranty  repairs:  Full  documentation, 

Ttie  Supef  Elf  tn eludes  a  ROM  monitor  for  pro- 
gram loading,  editing  and  execution  with  SIMGLE 
STEP  for  program  debuggini  which  is  not  in- 
cluded in  ottrers  at  the  same  price.  With  SINGLE 
STEP  you  cam  sb&  the  microproMSSor  chip  opera- 
ting with  the  unique  Quest  address  and  data  bus 
displays  before,  during  and  after  executing  \n- 
structions,  Also,  CPU  mode  artd  instruction  cycle 
are  decoded  and  displayed  on  6  LED  indicators. 

An  -RCA  1861  virteo  graphics  chip  allows  you  to 
connect  to  your  own  TV  with  an  inexpensive  video 
modulator  to  do  graphics  and  games  The-re  is  a 
speaker  system  included  for  writing  your  ovvn 
music  or  using  many  music  programs  afresdy 
written.  The  speaker  amplifier  may  also  be  used 
to  drive  relays  for  control  purposes. 


lect,  mDititor  select  and  single  step.  Large,  on 
board  displays  pFovitfe  output  and  oi^tionai  high 
and  iow  address.  There  js  a  44  pin  standand 
connector  slot  for  PC  cards  and  a  50  pm  connec- 
tor slot  ior  ttie  Quest  Super  Expansion  Board. 
Power  supply  and  sockets  for  atl  iC's  are  in- 
cluded in  the  price  plus  a  detailed  127pg.  instruc- 
tipn  manual  which  now  includes  over  40  pgs.  of 
software  into,  including  a  series  of  lESsqns  to 
help  get  you  started  and  a  music  program  and 
graphics  target  game.  Many  schools  and  yntver- 
sitfces  are  using  the  Super  Elf  as  a  course  of  5tudy. 
OEM's  use  it  for  training  and  R&O 

Remember,  other  computers  only  offer  Super  Ett 
features  al  additional  cost  or  not  at  all  Compare 
before  you  buy.  Super  EH  Kft  $106.95,  High 
address  option  SBJ5.  Low  address  option 
$9.95.  Custom  Cabinet  witti  dniied  and  label  I  ^ 
plexiglass  front  panul  $24.95.  Ail  metal  Expan- 
sion Cabinet,  painted  and  siik  screened,  with 
room  for  5  S- 100  boards  and  power  supply 
$57.IM].  NICad  Battery  Memory  Savor  Kit  S6,95. 
All  kits  and  options  also  completely  assembled 
and  tested. 

Quesldata.  a  software  pubhcatian  for  1 802  com- 
puter users  is  available  tjy  subscription  for 
$12.00  per  12  issues  Single  issues  51.50.  Is- 
sue$  l-t?  bound  $16.50, 

Tiny  Basic  Cassette  $10,00.  on  ROM  $3B. 00. 
(anginal  Elf  kit  board  $14.95.  1S02  software; 
Moews  Video  Graphics  $3.50,  Games  and  Music 
S3.W,  Chip  e.  interpreter  55.50. 


A  2^  key  KEK  heyboanJ  includes  IB  HEX  keys 

Super  Expansion  Board  with  Cassette  Interface  $89.95 


Thiis  JS  truly  an  astounding  value!  Ttus  board  has 
been  designed  to  allow  you  to  decide  how  you 
want  It  optinned.  The  Super  Expansion  Board; 
comes  with  4K  of  low  power  RAM  fully  address- 
able anywhere  in  64K  with  built-in  memory  pro- 
tect and  a  cassette  imteriace  Provisions  have 
been  made  lor  all  other  options  on  ihe  same 
board  and  it  fits  neatly  mto  the  hardwood  cabinet 
alongside  the  Super  Elf.  The  hoard  includes  Slots 
tor  up  to  &K  of  EPROM  {2708,  2756.  2716  or  TI 
2716)  and  is  fully  sackBletf.  EPROM  can  be  used 
f  or  th  &  monitor  and  Ti  ny  Basic  o  r  oth  er  pu  rposes . 

A  IK  Super  HOM  Monitor  $19.95  is  available  as 
an  on  board  option  in  270&  EPROM  which  has 
been  preprogrammed  with  a  program  Joader.' 
editoi  and  error  checking  mulfi  hEe  cassette 
re-ad,' write  software,  [relocatable  cassette  file) 
a n other exciusive  from  Quest.  Itindtjdes  register 
save  and  readout,  block  move  capahility  and 
video  graphics  driver  with  blinking  cursor.  Break 


points  can  be  used  with  the  regaster  save  feature 
to  isolate  pfograrTi  bugs  quickEy,  theo  follow  with 
siriQle  step  If  you  have  the  Super  Eicpansien 
iflard  and  Super  MiinittH  the  monitor  is  up  ana 
running  at  the  push  of  a  button, 

Otfter  on  board  ophons  include  Parallel  Input 
and  Output  F^rts  with  lull  handshake  They 
aHow  easy  connection  ot  an  ASCII  .keyboard  to  the 
input  port  RS  332  and  2Q  ma  Current  Loop  lor 
teletype  or  other  device  are  on  board  and  sf  you 
need  more  memory  there  are  two  S-t  BO  slots  for 
stahc  RAM  or  video  boards.  Also  a  1K  Super 
Monitor  version  2  with  video  driver  for  full  capa- 
bility disptay  Willi  Tiny  Basic  and  a  video  interface 
board  Parailet  I/O  Ports  $9.B5,  RS  23?  S4  SO, 
TTY  20  ma  l/F  $1.95,  S-1Q0  $4,50,  A  50  pin 
connector  ^et  with  ribbon  cable  is  available  at 
$15.25  for  ea.sy  connection  between  the  Super 
Elf  and  the  Super  Expansiidn  ^oanl. 

Power  Supply  Kit  tor  the  complete  system  fsee 


Muithvnlt  Power  Supply). 

Announcing  Quest  Syper  Basic—  SECOND  GENERATION 

A  new  enhanced  version  of  Super  Basic  now      Enhancements  include  increased  speed,  bullt- 


ava  i  i  ab  le .  Ou  est  was  the  f  i  rst  com  pa  ny  wor  Idwide 
to  ship  a  lull  sii!e  Basic  for  1602  Systems,  A 
complete  function  Super  Basic  by  Ron  Cenker 

including  floating  point  capability  wi-th  sctentihc 
notation  (number  range  ± .  1 7£-"f .  32  bit  mteger 
1 2  billion;  multi  dtm  airays,  string  arrays;  string 
manipulation;  cassette  I/O:  save  and  load,  basic. 
data  and  machine  language  programs:  arfd  over 
75  statements,  functions  and  operations. 


in  provisions  tor  Stringy  Floppy,  Floppy  Disc, 
Printer  Driver,  l;0.  user  derinible  command 
library  and  statement  renumbering. 

Easily  adaptable  to  most  1B02  systems.  Re- 
quires IBK  RAM  minimum  for  Basic  and  user 
programs.  Source  listing  lor  bott?  Serial  and 
Pa  r^  I  Id  1,'Q  inctuded- 

Stiper  ftasic  nn  Cassette  $4B.Dfi. 


Gremlin  Cotor  Video  Kit  S69.95 

32  X  16  aiphaiium erics  and  graphics,  up  to  6 
colors  with  6847  chip;  IK  RAM  at  EOOO.  Plugs 
into  Super  Elf  44  pin  bus  No  high  res.  graphics. 
On  board  RF  Modulator  Kit  S4.95 


1fl02  1EK  [}yfiamit^  RAM  Kit  S149.D0 

Expand ahle to  32K,  Hidden  refresh  w/docks  up  to  4 
MHz  w,.'nD  wait  states.  Addl   15K  RAM  t63.D0 

Super  Elf  44  pm  expansion  board;  3  female  and  i 
male  bus.  Board  plus  3  connectors  $£2.95 
Tiny  Basir  Eitended  on  [Cassette  $15.00 

(added  commands  include  Stringy,  Array,  Cas- 
sette 10  etc.) 

S- 1 00  4  ■  S  lot  Expa  ns^on  $  9. 95 

Super  hftcnttor  VI. I  Seurce  Listing         $15.00 


Elf  II  Adapter  Kit  $24  J5 

Plugs  mto  Eti  II  providing  Super  Elf  44  and  50  pin 
plus  S-IOO  bus  expansion.  (With  Super  Ex- 
pansion). High  and  i-ow  address  displays,  state 
and  mode  LED's  optionai  ST 8. 00. 


Super  Colof  8^100  Video  Kit  $129^5 

E)(pand3ble  to  256  x  192  high  resolution  color 
graphics,  6847  with  all  display  modes  computer 
controlled.  Memory  mapped.  IK  RAM  expanda- 
ble to  6K.  S-lOObus  1802, 6080, 6085,  ZSOetc 
Editor  Assembler  S25.00 

(Requires  minimum  ot  4K  for  E/A  plus  user 
source) 

1802  Titiy  Sasic  Sotirte  listing  $19,00 

Super  Monitor  V2. 0^,1  Sotirce  Listing  $2D.O0 


TERMS:    $5.00  min.  order  U.S.  Funits.  Calif  rtsid^ntsadd  6%tax. 

$10.00  min,  order  BankAmerit^ard  and  Master  Charge  and  COD.  Sl.QO  lnsitfani;e  optional. 
Shipping  charges  will  be  addtd  on  charge  cards. 


FREE:  Send  for  your  copy  of  our  NEW  1980 
QUEST  CATALOG,  Include  48c'  stamp. 


f^  Reader  Servfce—see  pag&  22S 


73  Magazine  •   December,  1980     197 


(^«HZ 


eIectroi)ic$ 


Toll  Free  Number 
800^528-0180 
(For  orders  only) 


1900  MHz  to  2500  MHz  DOWN  CONVERTER 

ThJ5  receiver  is  lunab^e  a  range  of  1900  io  2500  mc.anU  is  iritef\(Jed  for  amaleur  radio  use  The  local  oscillator  is  vo!tage  cootrolted  {i.e)  making  the  i-i  range  approximately  *j4 

to  88  rnc  jChannels  2  !o  T), 

PC  BOARD  WITH  DATA  . ..- l     ^ 

PCBOARDWITNCHfPCAPAC]TORS13 ■ $44.99 

PC  BOAf^D  WITH  ALL  PARTS  FOR  ASSEMBLY $69.99 

PC  BOARD  WITH  ALL  PARTS  FDR  ASSEMBLY  PLUS  2N6W3   , -  -  -  .$89.00 

PC  BOARD  ASSEMBLED  ANDTESTED .,..,.,, $99.99 

PC  BOARD  WITH  ALL  PARTS  FOR  ASSEMBLY  POWER  SUPPLY  AND  ANTENNA ...,.,. .$159,99 

POWER  SUPPLY  ASSEMBLED  ANDTESTED -^ - ..$49,99 

VAGI  ANTENNA  4' LONG  APPROX,  20  TO  23  08  GAIN - ^ S49.99 

YAOI  ANTENNA  4' WITH  TYPE  (N.  BNC.  SMA  Connector) -  ■  ■  ■   $64.99 

2  FOOTDlSHWaH  FEED  AND  MOUNT - -■  ■■ - %^2.92 

2300  MHz  DOWN  CONVERTER 

Includes  converter  mounted  in  antenna,  power  supply.  Plus  90  DAY  WARRANTY ^ . -  r . , .  . 

OPTION  #1  MRF902m  front  ^nd.{/dB  noise  figure)  ■  -  -  ■ - - -■ 

OPTION  $2  2N6603  in  front  end.  (5  dB  noise  figure) . - ,,,.., 

£300  MHz  DOWN  CONVERTER  ONLY 

10  dB  Noise  Figure  23  d  B  gam  I  n  bo*  wjth  N  conn,  fnpul  F  conn.  Qui  put      .  -... 

7  dB  Noise  Figure  23  dB  gam  in  box  wMh  N  conn.  Inpul  F  conn.  Oulput  ........ ...... 

5  dS  Noise  Figure  23  dB  gam  In  bo>(  witn  SMA  conn  Inpu!  F  conn  Output  ..  ...  

DATA  IS  INCLUDED  WITH  KITS  OR  MAY  Bt  PURCHASED  SEPARATELY.  .  

Shipping  @nd  Handling  Ct>st 

Receiver  Kits  and  Si. 50.  Power  Supply  add  $2.00.  Antenna  add  15.00.  Option  V2  add  $3,00.  F<>f  .complete  system  add  $750. 


$259-99 
$299.99 
$359.99 

$149.99 

.S169.99 
S189  99 

S15.00 


HOWARD/COLEMAN  TVRO  CmCUIT  BOARDS 

DUAL  CONVERSION  BOARD  $25  00 

Tt^is  board  provides  conversion  Irom  the  3.?-4  2  band  firsl  10  900  MHz  where'gam  and  baf^dpassTiHering  are  provided  and.  second,  to  70  MHz.  The  board  contains  both  local 
oscillasors.  one  f  u^ed  and  Ihe  other  variable,  and  Ihe  second  mixer.  Construction  is  greatly  sprnplitfed  by  the  use  of  Hybrfd  iC  amplifiera  tor  ihe  gam  stages.  Bare  boards  cost 
$25  and  M  iji  estirnated  that  parts  fof  consUuction  will  cost  $270.  [Note:  The  hivo  Avantet^  VTO's  account  for  $225  oJ  this  cost.} 

47  pF  CHIP  CAPACITORS  *^  °^ 

For  use  with  dual  conversion  board.  Consists  ot  6-47  pF. 

7OMH1IFBOARD         .  "■ $25.00 

This  circuit  provides  about  43  d8  gam  wiih  50  ohm  input  and  outpul  impedance,  II  is  designed  to  drive  the  HOWARD/COLEMAN  TVRO  Demodulator.  Theon-bosifd  band 
pass  filter  can  be  tuned  for  bandwidihs  between  20  and  35  MH?  with  a  passband  ripple  of  Jess  than  vj  diB.  Hybrid  tCsare-  used  for  1  he  gain  stages.  Bare  boards  cost  $25.  W  is 
estirnaled  Iha!  par^s  'or  construction  will  cost  less  than  $40 

.OVpF  CHIP  CAPACITORS     .,    v  ^^  ^^ 

For  use  wiftt  70  MH/  IF  Board.  Consists  of  7-. 01  pF. 

DEMODULATOR  BOARD ^^0.00 

This  circuit  takes  ttre  70  MH£  cenier  frequency  satellite  TV  signals  in  th-e  10  to  200  millivoU  range,  detects  (hem  using  a  phase  locked  loop,  deemphasizes  and  filters  the 
•result  and  ampHfres  the  resuM  to  produce  standard  NTSC  n^ideo  Other  outputs  include  the  audio  subcarrler.  a  DC  voltage  proportional  to  (he  strength  of  ttie  70  MHz  signal, 
and  AFC  voltage  centered  at  about  2  volts  DC.  The  bare  board  cost  $40  and  lotal  parts  cosi  less  than  $30.  . 

SINGLE  AUDIO  $15  00 

This  circuit  recovers  Ihe  audio  signals  frohi  the  6-3  MHz  frequency  The  Miller  9051  coils  are  tuned  to  pass  theS.B  MHz  subcarrier  and  the  Miller  9052  coll  tunes  for  recovery 
ot  the  audio 

DUAL  AUDIO     ^^^ "° 

DupS<cate  of  Ihe  single  audao  but  also  covers  tfie  6.2  range  *  t  ftn 

DCCONTROL  '  S1500 

This  circuit  controls  the  VTO's,  AFC  and  the  S  Meter. 


TERMS: 

we  REGRET  WE  NO  LONGER  ACCEPT  BANK  CARDS. 

PLEASE  SEND  POSTAL  MONEY  ORDER.  CERTIFIED  CHECK,  CASHIER'S  CHECK  OR  MONEY  ORDER. 
PRICES  SUBJECT  TO  CHANGE  WITHOUT  NOTICE.  WE  CHARGE  15%  FOR  RESTOCKING  ON  ANY  ORDER 

ALL  CHECKS  AND  MONEY  ORDERS  IN  US  FUNDS  ONLY 

ALL  ORDERS  SENT  FIRST  CLASS  OR  UPS. 

i 

ALL  PARTS  PRIME  AND  GUARANTEED. 

WE  WILL  ACCEPT  COD  ORDERS  FOR  $25  00  OR  OVER.  ADD  $2.50  FOR  COP  CHARGE. 

PLEASE  INCLUDE  $2.50  MINIMUM  FOR  SHIPPING  OR  CALL  FOP?  CHARGES 

WE  ALSO  ARE  LOOKING  FOR  NEW  AND  USED  TUBES. 
TEST  EQUIPfVIENT.  COMPONENETS  ETC. 


WE  ALSO  SWAP  OR  TRADE. 


FOR  CATALOG  SEE  JANUARY.  19B0.  H  Magazine.  10  Pages. 


(602)  242-8916 

21 1 1  W.  Camelback 
Phoenix,  Arizona  85015 


198     73  Magazine  •  December,  1980 


(?l^^ 


electror|ic$ 


FAIRCMILD  VHF 

95H90DC 
95H91DC 
11C90DG 
11C91DC 
HCaSDC 
11C70DC 

ncsaoc 

11C44DC/MC4044 

11C24DC/MC4024 

tlCOCDC 

\  1C05DC 

11C01FC 


AND  UHF  PRESCALER  CHIFS 

350  MH^  Pfescaler  Divide  by  10/11 

350  MHz  Prescaler  Drvide  by  5^6 

650  MH2  Prescater  Divide  by  10/11 

650  MHz  Prescafer  Divide  by  5/6 

1  GH7  Divide  by  245/250  Pre&cafer 

600  MH2  Flip/Flop  with  reset 

ECL  VCM 

Phase  Frequency  Detector 

Djal  TTL  VCM 

UHF  Prescalef  750  MHz  D  Type  Flip/Flop 

1  GHz  Counter  Divide  by  4 

High  Speed  Dual  &4  input  NO/NO^  Gate 


t0,50 

9  50 

16.50 

16.50 

29,90 

12,30 

4.53 

3.82 

3.82 

12.30 

50.DO 

15.40 


TRW  BROADBAND  AMPLIFIER  MODEL  CA615B 
Frequency  response  40  MHz  to  300  MHz 
Gain;  300  MHz  16  dB  Min,.  17.5  dB  Max 

50  MHz  010  '  1  dB  from  300  MHz 
Vol  t  age:     24  vo  Its  dc  at  220  ma  max.  S 1 9-99 

CARBIDE  —  CIRCUIT  BOARD  DRILL  BITS  FOR  PC  BOARDS 

Size:  35,  42.  47. 49, 51, 52  $2  15 

Size:  53,  54,  55,  5&,  57,  58,  63,  61 ,  63,  64,  65  1  85 

Si^e:66  1  90 

Size:  1-25  mm,  1. 45  mm  2  00 

Size:  3.20  mm  3-56 

CRYSTAL  FfLTERS:  TYCO  OOt  19880  same  as  2194F 

10  7  MHz  Narrow  Band  Cry s la i  Filter 

3  dQ  bandwidth  15  kHz  rr^in  20  dB  bandwidth  60  kHz  min.  40  dB  bandwidth  150 

kHzmrn. 
Ultimate  50  dB:  Insertion  loss  1 ,0  bB  max,  Hippie  1 ,0  dB  ma)^,  Ct.  0  +  /  -  5  pf  36O0 

ohms.  $5. 95 

MURATA  CERAMIC  FILTERS 

Models:     SFD-455D455kHz  $3.00 

SFB'455D455kHz  2.00 

CFM-4S5E  455  kHz  7.96 

SFE-10.7  10.7  MHz  5-96 

TEST  EQUIPMENT  -  HEWLETT  PACKARD  -  TEKTRONIX  —  ETC. 
Hewlett  Packard: 

491C  TWT  Ampiitier  2  to  4  Gc  1  watt  30  dB  gain  t1 150,00 

608C  10  rr\c  to  480  mc  1  uV  1o.5V  into  50  ohms  Signai  Generator  500.00 

608O  10  to  420  mc  .1  uV  lo.5V  into  50  ohms  Signai  Generator  50000 

61 2 A  450  to  1230  mc  .1  oV  to  .5V  into  50  ohms  Signai  Generator  750.00 

61 4A  900  to  2100  mc.  Signal  Generator  500.00 

616A   IS  to  4.2  Gc  Signai  Generator  400  00 

ei6B   1.8  to  4.2  Gc  Signai  Genefator  500  00 

61  &A   3  6  to  7.2  Gc  Signal  Generator  400.00 

61 8B  3  8  to  7.2  Gc  Signai  Generator  500.00 

620 A  7  to  11  Gc  Signai  Generator  500.00 

623Q    Microwave  Test  Set  900.00 

eaeA   fO  Gc  to  is  Gc  signal  Genefstor  2500  00 

695A   12.4  to  18  Gc  Sweep  Generator  900  00 

AH  tech: 

473  225  to  400  mc  AM/FM  Signai  Generator  750  00 

Singer 

MF5/VFI-4      Universal  Spectrum  Analyzer  with  1  kHz  to 27.5  mc  Plug  in    1200.00 

Keltsk: 

XR630-100     TWTAmpJifief8tol2  4Gc  100watts40dQgain  9200,00 

Polirad: 

203a2436/1102A 

Calibrated  Display  with  an  SSB  Analysis  Module  and  a  10  to 

40  mc  Single  Tone  Synthesizer  1500.00 


HAMLIN  SOLID  STATE  RELAYS: 

120 vac  at  40  Amps, 
input  Voitage  3  to  32vdc. 
240  vac  a(  40  Amps 
Input  Voltages  to  32  vdc. 


YOUR  CHOICE  $4.99 


RF  TRANSISTORS 

TYPE  PflfCE 

2N1561  $15.00 

2N1562  1500 

2N1692  15,00 

2N1693  15,00 

2M2632  45,00 

2N2857JAN  Z52 

2M2e76  12.35 

2N28eO  25.00 

2^2927  7.00 

2N2947  18.35 

2N294a  15.50 

2N2949  3.90 

2N2950  5.00 

2N3287  4.30 

2N3294  1  15 

2N3301  104 

2N3302  105 

2N3304  148 

2N3307  12,60 

2N3309  3.90 

2N3375  9.32 

2N3553  1.57 

2N3755  7.20 

2N381&  6.00 

2N3e66  1.09 

2N3866JAN  280 

2N3a66JANTX  4,49 

2N3924  3,34 

2N3927  12-10 

2N3950  26,86 

2N4072  1,80 

2N4135  2.00 

2N4261  14.60 

2N4427  1.20 

2N4957  3-62 

2N4958  2-92 

2N4959  2-23 

2N4976  19.00 

2N5090  12.31 

2N5106  403 

2N5109  1.66 

2N5160  3.49 

2N5179  1.05 

2N51Q4  2,00 

2N5216  47-50 

2N5583  4.55 

2N5589  6.82 


We  can  suppiy  any 

value  chjp  capac- 

itors you  may 

need 

PRICES 

1  to  10 

1.49 

11    50 

1.29 

51  ■  100 

,39 

101     1.000 

,69 

1,001  up 

49 

Toll  Free  Number 
800-528-0180 
{For  orders  only) 


TYPE 

2N5590 

2N5591 

2N5637 

2N5641 

2N5642 

2M5643 

2N6545 

2N5764 

2N5a42 

2N5e49 

2N5862 

2N5913 

2N5922 

2N5942 

2N5944 

2N5945 

2  N  6946 

2N6080 

2N6081 

2N6082 

2N60B3 

2N60B4 

2N6094 

2Ne095 

2N6096 

2N6097 

2N6136 

2NG166 


2N6439 

2H6459^PT9795 

2N6603 

2M6604 

A50-12 

0FR9O 

BLY568G 

BLY568CF 

CD3495 

HEP76/S3014 

HEPS3002 

HEPS3003 

HEPS3O05 

HePS300e 

HEPS3007 

HEPS3010 

HEPS5026 

HP35e31B 

HXTR5104 

MM1500 


PRICE 
$e  15 
11.85 
22  15 

6,00 
10,05 
15-62 
12.38 
27.00 

6-73 
21.29 
51.91 

3.25 
1000 
46,00 

8,92 
12;38 
14.69 

7.74 
10.05 
11.30 
13,23 
14.66 

7.15 
11.77 
20.77 
29,54 
20,15 
38,60 


45.77 
18.00 
12,00 
12.00 
25.00 

5.00 
25.00 
2500 
1500 

4.&5 
11.30 
29.88 

9,95 
19.90 
24.95 
11.34 

2.5« 

50  00 
32.20 


CHIP  CAPACITORS 

Ipf  27pf 

1.5pr  33pf 

22pf  39pt 

2,7pf  47pt 

3,3pt  56  pf 

39pt  6epf 

4.7pf  e2pf 

5.6pt  lOOpt 

6.8pf  llOpf 

8-2pf  I20pf 

lOpf  I30pf 

12pf  150pt 

15pf  I60pf 

18pf  laopf 

22pf  200pf 


TYPE  pfitce 

M  Ml  550  tlO.OO 

M  Ml  552  50.00 

MM1553  56.50 

MM1601  5.50 

MM1602/2N5842  7.50 

MM1607  8.65 

MM1661  1S.0O 

MM  1669  17.60 

MM  1943  3.0O 

MM2605  300 

MM260e  5.00 

MMSOOe  2.23 

MMCM91B  20.00 

MMT72  1.17 

MMT74  1.17 

MMT2a57  2.63 

MRF245  33.30 

MRF247  33.30 

MRF304  43.45 

MRF420  20.00 

MnF450  11.85 

MHF450A  11.es 

MRF454  21.83 

MRF4S8  2068 


MRF502  1.08 

MRF504  6.95 

MRF509  490 

MRF511  8.15 

MRF901  3.00 

MRF5177  21.62 

MRfe004  1,60 

PT4186B  3-00 

PT4571A  1.50 

PT4612  5.00 

PT4a28  5.00 

PT4640  5.00 

PTB659  10-72 

PT97&4  24.30 

PT9790  41.70 

SD1043  5,00 

some  3,00 

SD1118  5-00 

soil  19  3.00 


TRWMRA2023'1.5  42.50 

40281  10.90 

402B2  11.90 

40290  2,48 


220pf 
240  pf 
270pf 
300  pf 
330pf 
360pf 
390pf 
430pf 
470p 
5l0p 
560p 
620p 
6S0p 
820p 
lOOOp 


I200pl 
1500pf 
IBOOpf 
2200pf 
2700pf 
3300pf 
3900pf 
4700pf 
5600pf 
6800pf 
8200pf 
OlOmt 
012mf 
,015mf 
.OlBmf 


ATLAS  CRYSTAL  FILTERS  FOR  ATLAS  HAM  GEAR 

5.52  2.7/8 

5.595-27f8iU 

5.595  500/4^CW 

5  595  2  7LS8  YOUR  CHOICE  S24.95 

5.595-2. 7USB 

5.645-2.7/8 

9  0USB/CW 


t^  fleadef  Service— ^bb  page  226 


73  Magazine  *  December,  1980     199 


^— ♦  t^lfCtriinicji 


The 


Toll  Free  Number 
800-528-01 80 
(For  orders  only) 


MRF454 


S21,a3 


MRF45g 


$20,68 


NPISI  SILICON  RF  POWER  TRANStSTORS 


NPN  SILICON  RF  POWER  TRANSISTOR 


.  ,  ,  desigr^ed  tor  power  amplif^ef  applications  in  irtdusinaL  com 
mafciai  and  amateur  radio  equipment  to  30  MHz. 


Specified  }  23  Volt,  30  MHi  Chir  act  eristics  - 

Output  Power  =  80  Watt* 
Minimum  Gain  =  12  dS 
Efficiencv  =  50% 


designed      (oi      powet     aoiplitier     applications     irii 
commencat  and  afnaK'ur  ladio  pquipfneni  to  30  WH/ 


indusiiial 


SpecitiFd  12  5  Voft.  30  MH/  Characteristics  - 

Outpui  Pcjwpi      SOWdiis 
Miiitmum  Gdin      1?  dB 
EHicieiicv      &0''ii 

Capable  of  WrthiUPHliriq  30  1  Ltiad  VSWR  (nJ  RjimI  Ptnir   ^'ntl  VcC 


MRF472 


$2,50 


NPN  SILJCON  RF  POWER  TRANSISTOR 

.  de&igr^ed  prirnanly  for  use  in  Targe  signal  ok,;tpuT  ^mpirfier  stages 
Intended     for    use    m    Citizen  3 and    communicattons    equipmeni 
operating    n    27    MHz.    High    breakdown    voMages    M\Q^    a   high 
percent iige  of  up- modulation  m  AM  cifcufti. 

•    Specified  12.5  V.  27  MHz  Chaiacteriitics  - 
Powci  Output  -  4.0  Wat  is 
Power  G^m  -  10 dB  Mimmum 
Efficiencv  ~  65%  Typical 


MRF475 


$5*00 


NPN  SILICON  RF  POWER  TRANSISTOR 

designed  prrmanly  for  use  m  smgte  sideband  linear  Amplifier 
output  applicauor^s  in  citizens  band  and  other  communications 
equipmem  operatinig  to  30  MHz. 

•  Characierifed  for  Single  Sideband  and  Large  Signal  Amplifier 

Applications  Utili/mg  Low-Level  Modulation. 

•  Specified  13  6  V.  30  MH?  CharBCteristtcs  - 

Output  Power  -  12  W  (PEP! 
MinifTiiim  EHiciBncy     40%  (SSB) 
Outpui  Pow«F     4.0  W  (CW) 
Minimum  Efficiency  ^  50%  ICW) 
Minimum  Power  Gam  =   10  dB  fPEP  fii  CW) 

•  Common  Collettor  Characterisation 


MHW710 


-   2 


$A6.45 
4A0      to  A70HC 
UHF  POWER  AMPLIFIER  MODULE 


.  designed  tof  12  5  volt  UHF  powei  amplifier  ^pplicalioo^  m 
industrial  and  commercial  FM  equipmeni  oper^tirig  from  400 
lo512MHr, 

•  Specitipd  12  5  Volt,  UHF  Characieriiiic^ 

Output  Power  13  Watt^ 
Minimum  Gam  1  3  4  dQ 
Harmonics     40  dS 

•  50  i 2  lnpiuit/Ouu>ut  Impedance 

•  Guaranteed  Stability  and  Rugyednpss 

•  Gam  Control  Pin  for  Mantj^l  of  Automatic  Output  Level  Conirol 

•  Thin  Film  Hybrid  Conviruction  Gives  Coriiisienr  Per fotmante 

and  Rphabihty 


Tektronix  Test  Equipment 


DkfcAl  Ut 

lilArtwwl  Qm>.   T[-.l^«  ('I  til.  ir. 

^a^lutf  Utrt  mt*   ^iOt^  livrti^v  K  1*  I9*i/ 

5lf«1  Tr*™  ^mm-'^'^-^-  ^*^  '■'  T'Ht;  Huf  In 
£]u1    Tracv  S.K^  mi  P1h«  im 

^A<?1li*9  Satec  ttitq  \ir 

^tff^ttwa  fir^i^ier  \  ijo  19Vi  flwg  tl 

^Hn4i  fin/^    It' 

didrbsn6.  •^igfi  C*iit  fitig  |n 

•'  '■4T»}  tlig.h  CkAtn  PliUB  ]n 

Trj£p  Plug  3n 

m^n  fijiTfi  DC  Difrtfnwfial  Plk»^  tfl 

w  1.-      1  Dt  l^liTfcrtTititl  flslffl  Iti 
r  Higii  (itin  J'i«q   lit 

'iH'Mi^i'e  Wdve  Generator  A  to  ll**i 
r'tiviiiitiiififp  jhe  ta  40icnr 
AC  C«up3«l  Prsampl  1fi(*r 


■>  'ii. 


mm 

m 

tJi 

IM 
4irj 

46!lr 
W1 

Ml 
•i4l 


Lurrinnt  Probif  itoipl  If  ler 

Uraijiraifl:  Contrul  Unit 
'riijgi^r  CCHiHtdOwrt  Unit 
Pjjrt*bl<>  Ouil   Tr#Cf   WHH^   SLOpe 
PciflJLle  l>ud1   TrACf   jDCVtt;   \Cflpf 
DC  tu  i^tm\l  Scope  Fl^ck  HoHnt 
K  ta  ib^Z  ^Qp«  nich  tfouitt 
DC  to  3^ nil/    ScQpr 
DC  ta  lOmj  Scflpfl  RflCb  NDunt 
£C  ta  lOnti  SC43IMI  Hjck  Itownt 


120- oa 


-     lO 

Id 

TSO.Oi 

no.oo 

)tlM)i,4ll 


fcti  tltj 
&b.l>0 
./S   IMJ 

441.  Dti 
6M1CI 

363, M 

?fi.LUO 
ISO. OS 


Scopes 

with 

Plug- ins 

Ut4 

^•.A        ■^.'.■^^ 

■i4«i 

•    X-j'' 

**: 

«Wl»iif  *l0%    In 

A^tfl 

>#*  t 

^^t 

iAk         ac  t» 

IIM&l  Jkk^: 

^*-«  - 

.  1  ^:v    ■  1  <  k     A    .'^h 

*i-  "  ■                        W.  1 

rill' 

piii 

In'* 

Mi           at  is 

aflP*^J   -^«i|H>- 

•  k1>> 

«  «J  Ekt*i  Wtfti* 

Miifh  ^t>  flwg  ff 

Tubes 

<Ut^ 

1     'j.Ul 

■    '  ; 

i      ■ 

tiAm 

'-<    '.iK]- 

im-   !» 

c 

hVA 

i 

■■     JU 

'■             :i 

JW.QO 

».I1>I 

hbA 

^..<w 

■    ',"•,'» 

T^.OQ 

1^1 

|^J 

IW.Wl 

i]   •.' 

'jf.MKi 

(.J&H 

i-fai»A 

^'    iJO 

41. OU 

^mf 

*-  \Ihti 

^=:-   'lO 

:  '  .  .    . 

*i£.r»f] 

myi 

4^^isOA 

feW.M). 

4AJ^[^ 

MjOD 

?ihn 

I-4CDA 

fl.M 

•tr^ifc^JfA^ 

n.m 

7^Hi 

<-]Qn[lfl 

T«* .  M 

tiirfi 

^.m 

mj'/ 

ij^^OA 

I4b.™ 

MiK' 

^.m 

mmi 

'Allll^^EI 

(.1.  lift 

tUSA 

]2My 

«3^6 

KtiMf/Q 

■     Ml) 

ei;i 

?^.m 

iilH 

im^^ji^K 

U1JII) 

•jftW^A 

it  m 

i\^9*>m\r^ 

flfli"^ii)lt 

^^.ijrj 

dittp 

hMi 

i^^ii^ 

^CX^tlM 

9 4?. NO 

bi4^ 

b,m 

W66r^/ii'. 

tflJ'itUft 

tui,m> 

tki46Eim;'WA 

f  m 

Htj[in 

ao 


10. 4n 
i?,H.iiii 


200     7J  Magazine  ♦  December,  1980 


MICROWAVE   COMPONENTS 


COMPUTER  I.C.  SPECIALS 


ARRA 


2416 

3614-60 
KU52QA 
4684-20: 
6684-2QF 

VarTable  Attenuator 
Vsriabte  Attenuator 
Variable  AUenuator 
Variable  Attenuator 
Variable  Attenuator 

0 

u 

0 
0 

to 
tc 
to 
to 

60dB 
i  26,5 

leodB 

General  ^/ 

icrowave 

GHi 


Directional   Coupler  2  to  4GHj  2 MS  Type  H 

Hewlett  Packard 


H4S7B 
H4e7fl 
A77a 

X4e?B 

J  4  68  A 
4  78  A 

0382 
X382A 


394A 

NK292A 

K4^2A 

a436A 


a439A 
8471A 

H53^A 
G532A 

J532A 


909A 


IGO  ohffls  Neg.  Ttiennistor  Mount  (MEW) 

100  ohms  Neg  Thermistor  Mount  (USED) 

200  ohms  Ht^  Thenm'&tor  Mount  (USED J 

lOD  olwis  ^eg,  Thermistor  Mount  (USEDj 

IDO  ohms  rieg.Thermi5t&r  Mount  (USED) 


LOO  ohms  Neg  Thermistor  Mourt   (USED) 
200  ohms  Neg  Thermistor  Mount   (USED) 

5. 85  to  e,2  mz  Variable  Attenuator  0  to  &0d6 
B.2  to   12.4  GHi  Variable  Attenuator  G  to  SOdB 


I   to  2  GHi  Variable  Attenuator  6  to   l,20d6 

yaveguide  Mapter 

la  to  26.5  GHi   Crystal    Detector 

Bandpass  Filter  8  to  12.']  GHz 


2  9ii  Notch  Filter 

RF  Detector 

7.05  to  10  &Hz  Frequency  Meter 
3.95  to  5.85  GH2  Frequenty  Meter 
5.85  to  8.2  GHz   Frequency  Meter 


Carriige  with  a  444 A  Slotted  Line  Ifntuned.  Detector  Probe 
and  S09B  Coaxial  Slotted  Section  2.6  to  18  GHz 


Merrimac 


AU-25A/ 
ALI-Z6A/ 


901115  Variatjle  Attenuator 
BUIWI  Variable  Attenuator 


Microlab/FXR 


X63SS 
601-Bie 

yfiioD 

Horn  fi.2  -   12.4  GHz 
X  to  Pt  Adapter  B.2  - 
Coupler 

12  A  GHz 


Nardd 


4anC'ia/ 

4014-10/ 

4014C-6/ 

4015C-10/ 

40150-30/ 

3044-20 

3040-20 

3043-20/ 
3003-10/ 
3003-30/ 

3043-30/ 

22574 

3033 

3032 

784/ 

22377 

720-5 

3503 

PRD 

UlOl 

XlOl 

ClOl 

20SA/367 

1358 

leSBSJ 

196C 

170fi 

seeA 

140A.C»D,£ 
109J  J 
WtlNSCHR  ENG. 


J2S40A  Directional   Coupler  2i to  4  GH^   iOdb  Type  SMA 

22538  Directional   Coupler  3,S5  to  8  Q^z   lOdB  Type  SMA 
22S76  Directional   Coupler  3.a5  to  8  GHi  6dfl  Type  SMA 

22539  Directional    Coupler  7.4  to  12  GHz  lOdB  Type  SMA 
23105  Oi recti ona)   Coupler  7  to  12,4  GHz  30dB  Type  SMA 
Directional   Coupler  4  to  3  mz  20dB  Typo  fi 
Direci tonal   Coupler  240  to  500  MC  30dB  Type  N 


22006  Directional  Coupler  1 , 7  to 
220 U  Directional  Coupler  2  to  4 
22012  Directional   Coupler  2  to  4 


4  GHj  2Od0  Type 
mi  lOdB  Type  N 
mi  30de  Type  n 


H 


MEMORY 

DESCRIPTION 

S  50 

DO 

75 

00 

270B 

IK    K 

S  EPROM 

100 

00 

2716/2516 

2¥.  X 

a  EPROM  I 

jVolt  Single 

Supply 

100 

00 

2114/9U4 

U  ^ 

4  Static 

RAM  450fis 

100 

00 

2114L2 

IK  « 

4  Static 

ftAM  25Dns 

2U4L3 

IK  X 

4  Static 

RAM  3 sons 

fl027 

4K  s 

1   Dynamic  ft AM 

4060/2107 

4K  X 

1  Dyn^m^it 

;  RAM 

75. 

00 

4050/90-50 

4K  ;( 

1   Dynamif 

:  RAM 

21llfi-2/eill 

^56  ] 

(  4  Static 

:  RAM 

2112A-2 

^S&  ) 

t  4  Static 

:  RAM 

21t5AL-2 

IK    X 

1   Static 

RAM  55na 

6104-3/^104 

4K   X 

1   Static 

RAM  32Dns 

150 
100 

.00 
.00 

,■  .1 

7]4l-2 

4K  X 

1   Static 

RAM  200ns 

MCM6641L20 

4K  X 

2.Stitic 

RAM  2D0ns 

9131 

IK  X 

1  Static 

RAM  300nB 

lUO.OD 
125.00 


150.00 
150.00 

250.00 
250.00 


250-00 

65.00 

250.00' 

75.00 


75.00 
50,00 

300.00 
300.00 
300.00 


175.00 


100,00 
100,00 


60.00 
35.00 
75.00 


22007  Directional   Coupler  1.7  to  3.5  GH;  30dB  Type  H 

Directional   Coupler  2  to  4  GK^   lOdH  Type  N 

Coaxial   Hybriff  2  to  4  GH2   3dB  Type  H 

Coax f 31   Hybrid  950  to  2  GHz   3  dB  Type  N 

223&0  Variable  Attenuator   ]   to  90de  2  to  2,5 

Wavegijide  to  Type  H  Adapter 

Fixed  Attenuator  &.2   to  14,4  ZHz   &  dB 

waveguide 


90,00 
90,00 
90.00 
95.00 
95.00 
125.00 
125.00 

125,00 
75.00 
75,00 

125. OO 

125,00 

125.00 

125.00 

GHz  Type  SMA  550,00 

35.00 

50.00 

25.00 


12.4  to   18  GHz  VariabVe  Attenuator  0  to  60dB 

8.2  to  12.4  GHz  Variable  Attenuator  0  to  60dB 

Variable  Attenuator  0  to  50dB 

Slotted  Line  with  Type  N  Adapter 

.e.2  to   12.4  mz  Variable  Attenuator  0  to  50dB 

7,05  to  10  GHz  Variable  Attenuator  0  to  40dB 

8.2  to  12.4  mi  Variable  Attenuator  0  to  45dB 

3.95  to  5,a5  mi  Variable  Attenuator  0  to  45da 

Frei^uency  Meter  5,3  to  6.7  GHz 

Fixed  Attenuators 

Fijced  AttenLjator^ 

?692  Variable  Attenuator  +30  to  60dB 


300.00 

200.00 
200.00 
100,00 
100.00 
100.00 
100.00 
100,00 

100-00 
25.  00 
25.00 


C.RU/s  EOT 


MC680DL 

MCM6aiOAP 

rtCM6&AlOP 

MCM6eS10P 

WC6620P 

MceeaoL 

«C6e21P 

MC6eB2lP 

MCM6S30L7 

HC6a40P 

MC68a5P 

MC684  5L 

f**C6850L 

MC6B52P 

MC6852L 

MC6854P 

MC6B60CJCS 

MC6862L 

MK3850JJ-3 

MK3&52P 

MK3852N 

MK3B54N 

3006- 1 

SOBOA 

Z30CPU 

6620 

6530 

2650 

TMSIOODNL 

TMS4024.*^C 

TMS6011KC 

MC144U 

AY5-4007D 

AY5-9200 

AY5-910O 

AY5-23?6 

AY3-8SD0 

TRL402A 

PR1472B 

PT1482B 

&257 

B251 

8226 

d212 

MC14410CP 

MCi4412 

MC1440& 

MCI  4409 

HCUaSL 

MCI  4691 

MC1405L 

MC1406L 

MC1408/6/7/S 

MC1330P 

MCJ349/50 

MC1733L 

LM565 


MicrDprDcessor 


S 
8 
B 


Static 
Static 
Static 


RAM  450ns 
RAM  360ns 
HAM  25Dn?i 


128 

123 

128 

PIA 

PEA 

P3A 

PIA 

M.i  kbug 

PTM 

CRT  Controller 

CRT  Controller 

ACIA 


SSOA 

SSDA 

AOLC 

0-600  BP5  Modem 

2400  aPS  Modem 

F8  Microprocessor 

FB  Memiory  Interface 

FS  Memory    Enteffate 

F8  Direct  Memory  Access 

Microprocessor 

Microprocessor 

Mitroprocfji^iiOr 

PIA 

Support  For  65O0.  series 

Microprocessor 

Four  &it  MicroprocesfiOr 

9  )i  64  Digital  Storage  Buffer 

UART 

Bit  -Rate  Generator 

Four  Digit  Counter/Oisplay  Oriver$ 

Repertory  Dialler 

Push  Button  telephone  Diellers 

Keyboard  Encoder 

TV  Game  Chip 

UART 

UART 

UART 

DMA  COrttroller 

Communication  Interface 

System  Controller  &  Bus  Driver 

a  Bit  fnput/Output  Port 

2  of  fi  Tone  Encoder 

Low  Speed  ModeiTi 

Binary  to  Phone  Pul$e  Converter 

Binary  to  Phone  Pulse  Converter 

RS232  Oriver 

RS232  Receiver 

A/0  Converter  Subsystem 

6  Bit  D/A  Converter 

8  Bit  D/A  Converter 

Low  Level  Video  Detector 

Video  IF  Amplifier 

LW7  33  OP  Amplifier 

Phase  Lock  Loop 


FIFO) 


m*^ 


Toll  Free  Number 


PRICE 


S  7.99 

20,00 

6.99 

8.99 


7. 
3. 
3. 
3. 
3. 


99 
99 
99 
99 
99 


3,99 

4.99 
14.99 
14.9^ 
14,99 
10,99 


13,80 
3,99 
4.99 

fi.99 
9.99 

$,99 
9.99 
14,99 
8.99 
29.50 
33,  {10 
lp.99 

5.99 
1K99 

22.00 
29.0D 
14.99 
9,99 
16-99 


9, 
9. 


99 
99 


4.99 

8.99 

14.99 

7.99 

15.99 

10.99 

9.99 

9.99 

9.99 

11,99 

S.99 
9.99 
7.99 
19,99 
5.99 
9.99 
9.99 
9.99 

9.99 
9.99 
5.00 
5-00 
9:99 
14,99 
12,99 
12.99 
1..,  00 
1.D0 
9.00 
7.50 
4.50 
1.50 
1,17 
2.40 
2.50 


electroqic^ 


800-528-01 80 

(For  orders  only)  (602)  242-8916 

2111W.Camelback 
Phoenix,  Arizona  85015 


73  Magazine  •  December,  1980    201 


KIM 


SATELLITE  RECEIVER  SYSTEM 

The  entertainment  opportunity  of  a  lifetime! 

Look  what  kLM>s  SKY  EYE  1  of f ers : Near  1 y  100  channles  of  the  latest 
movies*  sports,  news*  comedy,  classic  films,  specials,  religious 
programs  and  much  snore  *....  al  1  in  clear,  sharp  studio  quality  picture 
and  sound.  Forget  about  "fringe"  or  no-reception  areas,  ghosts,  fading, 
imaging  and  all  the  other  problems  of  TV  reception.  KLM.s  SKI  EYE  1  is 
your  direct  link  to  the  11  TV  satellites  now  orbiting  above  the  U.S. 
You, 11  experience  great  shows  and  the  greatest  picture  quality  you,ve 
ever  seen, 

KLHtS  SKY  EYE  1  is  a  compl ete  system*  featuring  performance-proven 
"state  of  the  art"  electronics  design  and  materials.  All  you  need  is  a 
modest  amount  of  space  for  the  special  parabolic  antenna(it^s  screened 
surface  blends  with  the  landscaping  to  become  a  discrete  addition  to 
your  yard), Inside  your  home ^a 11  those  channels  are  accessible  through 
the  compact  SKY  EYE  1  Control  Center. 

With  KLH.s  SKY  EYE  1  your  TV  becomes  a  true  enterainment  center, 
bringing  you  an  amazing  variety  of  great  shows-something  to  please 
every  member  of  your  family. 

KLH,s   SKY   EYE  1  SYSTEM 
Control  Center 

*  CONTINUOUS  CHANNEL  TUNING 

*  CONTINUOUS  AUDIO  TUNING  5.8  TO  7.4  MHZ 

*  POLARITY  COKTROL  CAPACITY , MOMENTARY  AND  LIMIT  MODELS 

*  SEPARATE  REGULATED  POWER  SUPPLIES  FOR  LNA  AND  RECEIVER 

*  STANDARD  RG-59  COAX  TO  RECEIVER  UNIT 

Recei  ver  Unit 

*  SINGLE  CONVERSION  IMAGE  REJECTION  MIXER{greater  linearity 
and  video  reponse  than  any  PLL) 

*  BUILT  IN  DC  BLOCK 

*  MODULAR  CONSTRUCTION 

*  WEATHER-PROOF  ENCLOSURE 


CONTROL  CENTER  and  RECEIVER  UNIT 

Antenna:  KIM  Parabolic  Dish 

*  SCREENED  FOR  LIGHT  WEIGHT  AND  LOW  WIKDLOAD 

*  EASY  AZIMUTH  AND  ELEVATION  CHANGES 

*  MODEST  BASEMOUNT  REQUIREMENTS 

*  HIGH  GAIN  LNA  (AVANTEK) 

*  MOTOR    DRIVEN    POLARITY    CHANGES 

*  12    FOOT    OR    16    FOOT    PARABOLIC    DISHES 

12    Foot    $3000.00 

16    Foot    $3500.00 


$1500.00 


$    800,00 


202     73  Magazine  •  December,  1980 


TEST  EquiPMEKT  SPECIALS 


HEWLETT  PACKARD 


18QA  Oscilloscope  with  a  1801A  Dual  Channel  Vertical  Amplifier  Plug-in 
SOHHz  and  with  a  1821A  Time  Sase  and  Delay  Generator  Plug-in* 

$1250.00 
180A  Osci 1 loscope  with  a  1802A  Dual  Channel  Vertical  Amplifier  Plug-in 
lOOMHz  and  with  a  iB'iZfk   Time  Base  and  Delay  Generator  Plug-in,         $1350.00 

181A  Cscil loscope  with  a  1803A  Differential  DC  Offset  Amplifier  plug-in 

and  with  a  182SA  Time  Base  and  Delay  Generator  Plug-in.  $1950.00 

181A  Oscinoscope  with  a  1807A  Dual  Channel  Vertical  Amplifier  Plug-in 

35MHz  and  with  a  1822A  Time  Base  and  Delay  Generator  Plug-in.  $1550.00 

(Ue   will  be  glad  to  mix  the  above  systecns  any  way  you  would  like  them.) 

183A  Oscilloscope  with  a  1831A  Direct  Access  Vertical  Amplifier  Plug-in 

600MHz  and  with  a  1840A   Time  Base  and  a  1841A  Time  Base  and  Delay 

Generator  Plug-in.  $2500,00 

140A  Oscilloscope  with  a  140IA  Dual  Channel  Vertical  Amplifier  Plug-in 

and  with  a  1420A  Time  Base  Plug-in,  $  799.00 

14 lA  Osci 1 Vo scope  with  a  14 02 A  Dual  Channel  Vertical  Amplifier  Plug- in 

20KHZ  and  a  1421A  Time  Base  and  Delay  Generator  Plug-in«  $1690*00 

I40A  Oscilloscope  with  a  1410A  Dual  Trace  Sampling  Plug-in  DC  to  IGHz 

and  with  a  1425A  Sampling  Time  Base.  (Built  in  probes*}  $2200,00 

I41A  Oscilloscope  with  a  I411A  Dual  Trace  Sampling  Plug-in  DC  to  12.4 

GH2,  and  with  a  1424A  Sampling  Time  Base.  $2000*00 

14QA  Oscil loscope  with  a  HllA  Dual  Trace  Sampling  Plug-in  DC  to  12.4 

GHz.  and  with  a  1424A  Sampling  Time  Base.  $1500,00 

1430A  Feed   Thru  Sampling  Head  DC  to  12.4GKz,  28picosecond  risetime,     $1250,00 
******************************************************************************* 

302A  Wave  Analyzer  High  selectivity  and  sensitivity  with  frequency  resolution 
of  lOHz,  20H2  to  50KHZ  range  +-11I,  30mv  to  300v  full  scale  range.  Built  in 
AFC.  ?5dB  dynamic  range*  $  975.00 

31QA  yave  Analyzer  This  unit  is  a  high  frequency  wave  analyzer.  A  narrow  band 
selective  voltmeter.  Its  selectivity  allows  analysis  of  closely  spaced  fund- 
amental s i gnal s , harmoni cs  I  and  i ntermodul ation  products.  Frequency  range:  IKH2 
to  1.5MHz, (3000  Hz  bandwidth).  Frequency  Accuracy:  +- ( 1%+300H2, }Selecti vity : 
3IF  bandwidths  200Hz,1000Hz  and  3000Hz,  Voltage  range:  lOuv  to  lOOv  full  scale. 
Dynamic  range:  75dB  $1050,00 


$330,00 


431B  Power  Meter  Measures  RF  Power  lOuw  to  lOmw.  IOMH2  to  40GHz. 
with  478A  Mount  and  cable. 


431C  Power  Meter  Measures  RF  Power  lOuw  to  lOmw.  IOMH2  to  40GHz, 
with  478A  Mount  and  cable. 


$580.00 


73  Magazine  •  December,  1980    203 


TEST  EquiPHEKT  SPECIALS 
HEWLETT  PACKARD 

S05A  Slotted  Line  500HC  to  4GHz  ,  1.04  residual  SIpIR.  $  250.00 

809B  Carriage  l^ttti  806B  Coaxial  Slotted  5ection(.3  to  12GHi)  a  X810B 
Slotted  Section(8.2  to  12,46Hz)  a  HBiOB  Slotted  Section  (7.05  to  iOGHz) 
a  X281A  X  to  N  adapter  a  H281A  H  to  N  adapter  a  HX2928  H  to  X  adapter  a 
444A  PrQbe(2.6  to  18GHz)  a  PRD250  Probe  (2.4  to  12.4GHz)  J  650.00 

34QA  Hoise  Figure  Meter  Automatically  Measures  and  Displays  If  and  RF 
Amplifier  Koise  At  30  or  60MHz,  Bandwith  of  IHHz.  $  200.00 

340B  Koise  Figure  Heter  Automatically  Measures  and  Displays  IF  and  RF 
Amplifier  Noise  at  30  or  60HHz.  Bandwidth  of  IMHz,  input  requirements 
-60  to  -10  dBm,  $  350.00 

AIL 

74A  Automatic  Noise  Figure  Meter  with  a  type  70  Diode  Noise  Generator 

10  to  250HHZ  a  type  71  Power  Supply  a  07049  Noise  Generator  3,95  to 

5.85GHz  a  07010  Noise  Generator  .20  to  2.6  GHz  a  0752  Noise  Generator, 

$  650.00 
***************************************************************************** 

TEKTRONIX 

661  90PicQsecond  Risetime  Sampling  OsciHoSGope  with  a  4S1  350Picosecond 
Dual  Trace  Sampling  Plug-In  DC  to  1GH2*,4S2  90PicosecQnd  Dual  Trace  Plug- 
In  DC  to  3.5GHz. p  4S3  350P1cosecond  Dual  Trace  Plug-In  DC  to  lGHz.{an 
above  Plug-In, s  are  2fnv/cfn  to  20Dmv/cm.  and  with  a  5TI  Plug-In  Sampling 
System  Timing  ,  ins/cm  to  lOOus/ctn*  (useful!  beyond  5GHz.)  $1000,00 

SPECTRUM  ANALYZER  PLUG-IH,s 

1L5  50Hz  to  IMHz  ,  Center  Frequency  50Hz  to  990KHr,  Dispersion  *10Hz/cm 

to  lOOKHz/cm  I  Deflection  Factor  lOuv/cm  to  2v/cm.  $1000.00 

ILIO  IMHz  to  36HH2  ,  Bandwidth  resolution  of  lOHz  to  IKHz.Cal ibrated 
Dispersion  from  lOHz  to  2KHz  ,  Sensitivity  of  -lOOdBm.  $  900*00 

1L30  925MH2  to  10.5GHz  ,  Bandwidth  resolution  of  IKHz  to  lOOKHz,  Dispersion 
of  IKHz  to  lOMHz/cm  ,  Sensitivity  of  -75dBni  to  -IQSdBm.  $1100.00 

IL40  1.5GHz  to  40GHz,  about  same  specifications  as  above.  $1500.00 

3L10  IMHZ  to  36MH2  same  as  ILIO  But  For  560,561  Mainframe  Oscilloscopes. 

SIODO.OO 

*««#**««*  ^  *  ^  *«*«*  A^  1»  ************  4*  ikr  *****************  *-4t  *****«**#«###  it -it  *#  + -A^  «^ 4- «  4^  «^# 

HEWLETT  PACKARD 

852A  with  a  8551B  Spectrum  Analyzer  a  Highly  Versatile  Instrument  that 

Covers  10. IMHz  to  40GHz.  Sensitivity  of  up  to  -lOOdBm.  Ten  Calibrated 

Spectrum  widths  from  lOOKHz  to  2GHz.  Large  7  and  10cm  Display. 

The  e52A  is  a  Storage  Display,  $2000*00 

With  The  851A  Display  (NOT  STORAGE)  $1500.00 

With  The  B51B  Display  (NOT  STORAGE  BUT  NEWER)  $1800,00 

WE  ARE  LOOKING  FOR  HEWLETT  PACKARD  MODELS  S553B   Ect.FOR  THE  HIS  or  T 


204  73  Magazine   •  December,  1960 


TYPE 

UG-273 

UG-146/U 

UG-83a/iJ 

NG-318/y 

S74 

UG-394h/u 

UG-355/U 

UG-£le/u 

UG-58a/u  or  UG-58b/y 

SO-239 

UG-1094a/u  or  UG-625b/u 

UG-290a/u  or  UG-185/u 

P  L  -  2  5  9 

UG-175  or  UG-176 

UG-S8/U  or  UG-260/U 

S0'239BM 

UG-57b/u 

UG-27d/u 

UG-274a/u 

UG~636a/u 

UG-564/u 

UG-635/U 

UG-565a/u 

UG~201a/u 

UG-306/U 

M-3  58 

UG-49ib/u 

UG-914/U 

PE9090 

PE9089 

PE9088 

PE9087 

PE9086 

PE9085 

PE9084, 9083, 9082 

PE9081 

PE9080 

PE9079 

PE9078 

PE9077 

PE907  6 

PE9075 

PE9074 

PE9073 

PE9072 

PE9071 

PE9O70 

Tektronix  011-0049-01 

FXR   AH-A92 

FXR   AH-A93 

FXR   AH-A94 


R  F  CONNECTORS  COAX 

DESCRIPTIOM 

Female  8KC  to  PL-259 

SO-239  to  N  Male 

N  Female  to  PL-259 

PL-259  to  N  Male 

N  Female  to  General  Radio 

BNC  Male  to  N  Female 

BNC  Male  to  50-239 

N  Cable  Connector  Male 

N  Female  Pannel 

UHF  Female  Pannel 

BNC  Female  Bui khead 

BNC  Female 

UHF  Cable  Connector 

Adapter  for  RG58  or  RG59  Cable  For  PL-259 

BNC  Male  50  or  75  ohm 

SO-239  to  PL-259  Quick  Disconnect 

N  Male  to  Male 

N  90^  Male  to  Female 

BNC  T  Male  Female  Male 

BNC  Female  to  "C"  Male 

'X"  Female  to  N  Male 

BHC  Male  to  "C"  Female 

N  Female  to  "C^"  Male 

BNC  Female  to  N  Male 

BHC  90^   Male  to  Female 

UHF  T  Female  Male  Female 

BNC  Male  to  Male 

BNC  Female  to  Female 

TNC  Female  to  H   Male 

TNC  Male  to  N  Female 

TNC  Female  to  TNC  Female 

TNC  90O  Male  to  Female 

TNC  Male  to  Male 

TNC  Female  to  Female 

TNC  Panel  and  Bulkhead 

BNC  Male  to  F  Female 

BNC  Male  to  TNC  Female 

N  Female  to  SMA  Female  Panel 

BNC  Female  to  SMA  Female  Panel 

^'C"  Female  to  SMC  Female  Bulkhead 

SMA  Hale  for  .141  semi-ridg 

SMA  Hale  for  .085  semi-ridg 

SMA  Flange  Female 

SMA  Flange  Male 

SMA  Female  Short 

SMA  Male  50  ohm  load 

SMA  Female  to  Female 

50  ohm  2  watt  term.  BNC  Female  to  Male 

O.BdB  SMA   Male  Female  Att. 

l.OdB  SMA   Male  Female  Att. 

l,5dB  SMA   Male  Female  Att. 


PRICE 

EACH 

$    3. 

.00 

10. 

00 

10. 

00 

10. 

.GG 

15. 

.00 

10. 

.00 

5. 

00 

4. 

00 

4. 

50 

1. 

.00 

1. 

35 

2. 

50 

1. 

.00 

50 

1. 

50 

3. 

00 

4. 

50 

6, 

50 

5, 

.00 

10. 

,00 

10. 

00 

10. 

00 

10, 

.00 

5. 

00 

3, 

00 

3. 

25 

5, 

00 

3. 

00 

10. 

.00 

10. 

DO 

12. 

00 

20. 

00 

12. 

.00 

20. 

.00 

3. 

00 

5. 

00 

10. 

.00 

30. 

.00 

30. 

00 

30 

.00 

3, 

.00 

3. 

.00 

5, 

.00 

5. 

00 

7. 

50 

10. 

.00 

10, 

00 

15. 

00 

15, 

00 

15. 

00 

15. 

00 

■ttiF 


COAX  CABLE  SPECIAL  SALE 


Microdot  RG-174 

miniature  50  ohm  coax  cable  for  small  jobs. This  cable  was  made  to  meet 

EHilitar^  spec.(PRICE  PER  FOOT) 

1  to  25  foot  .15  *  /  26  to  50  foot  .12    t    /    51  to  100  foot  *11  t    t    101  up  .10  i 

Microdot  RG-402U 

,141  miniature  50  ohm  hard  line  /  semi-ridg  coax  for  use  with  SMA/SMC  ect, 

miniature  coax  connectors*  This  cable  is  very  low  loss  and  is  used  for 

High  Frequency  projects.  (PRICE  PER  FOOT) 

1  to  10  foot  $5.00  /  11  to  25  foot  $4.00  /  26  to  50  foot  $3.00  / 


Microdot  RG-4Q2U  with  two  Male  SMA  Connectors  Assembled. 
Aprox.  10  to  16 '^~"I 

Microdot  RG-4Q2U  with  two  Male  N  Connectors  Assembled, 
Aprox.  10  to  20". 


$    5.00 


$15.00 


73  Magazine  •  December,  1980     205 


KC/KHZ 

15.75 

24 

Z6,25 

32 

49.71 

70 

aK9 

96 

100    (note) 

114.  1666 

153.6 

250 

285.714 

327-82 

576 

600 

980 

998,4 

MC/HirZ 

I 

1.024 

1.05145 

1.06515S 

1.077368 

1.092105 

1,125263 

1,136316 

1,  165789 
1,197368 
1.3 

1.3065 
1.6896 
1.6S25 
1,7 

1.76375 
1,77125 
1.773125 
1,78675 
1.81875 
1. 84 51 25 
1,346625 
1.84575 
1.846 
1.84825 
1.84975 
1.8575 
1.908125 
1,925 
1.925125 
1.927 
1.93Z 
1.982 
1.985 
1,9942 
1,995975 
1.9647  5 
1.999659 
2. 

2.0285 
2,05975 
2.078 
2.082 
2,125 
2.126175 
2.12795 
2-  1315 

2,  133275 
2,  13505 
2.1425 
2.144625 
2.14675 


nz/mz 

2.14B875 

2-151 

2,153125 

2.15375 

2.15525 

2.157375 

2,1595 

2,16375 

2.165875 

2.  170125 

2,17225 

2.1765 

2,17925 

2.18475 

2.18575 

2.194125 

2.198 

2.207063 

2.208313 

2,209563 

2.21812 

2,210813 

2.212063 

2,214562 

2.214563 

2.215625 

2.217938 

2.21975 

2-222125 

2,22325 

2,22675 

2,23725 

2,2395 

2,24075 

2.241 

2-246 

2.2475 

2,264 

2.2925 

2,2975 

2.3 

2.32 

2.326 

2.32625 

2.3525 

2,35256 

2,368 

2.374 

2.375 

2.38725 

2.394 

2,395 

2.396875 

2.42 

2.4375 

2.44275 

2.4495 

2-45 

2,482 

2.486 

2,5 

2.51375 

2.581 

2.604 

2.618 

2.6245 

2.62825 

2.633125 

2.63575 

2,639 

2.64325 

2.647 


HC/HHZ 

2,65075 

2.6545 

2.65825 

2,66 

2.662 

2.66575 

2.6695 

2,677 

2.68075 

2.681 

2.6845 

2.6882  5 

2.69575 

2.702 

2 . 7  04 

2.71075 

2.715 

2-7  J6 

2.723 

2.73 

2.7315 

2.73225 

2,732625 

2.733 

2.737 

2,73975 

2.742125 

2.7425 

2.744 

2.7445 

2,74  4  7$ 

2.746875 

2.751 

2.754 

2.75525 

2.7  6237  5 

2.7735 

2.776625 

2,78 

2,814 

2.817 

2,8225 

2,835 

2.85 

2.854 

2.854285 

2,865 

2.868 

2,8725 

2,876875 

2.887 

2,889 

2.894 

2.92545 

2,931 

2,94375 

2,945 

2,94675 

2.952 

2.966 

2,97125 

2,973 

2,96 

2-981 

2,98325 

2.987 

3, 

3.0Q1 

3,0235 

3.049 

3,053 

3.062 


CRYSTALS 

p.  99 

MC/MH2 

3.067 

3.074 

3, 1 

3.1125 

3,  126 

3,137 

3.13975 

3,  1435 

3,  144 

3,145 

3.1545 

3 ,  1  58 

3.1585 

3,1615 

3.1625 

3-  166 

3.16975 

3-177 

3.181 

3.1825 

3,18475 

3.1885 

3.2035 

3.20725 

3.2166 

3.2175 

3-2315 

3-23275 

3-2365 

3.23775 

3,2385 

3.238875 

3-23925 

3-24025 

3.2405 

3,241 

3.2425 

3.244 

3.248875 

3.24925 

3-24975 

3,2515 

3.253625 

3.255 

3-256125 

3,258625 

3.261 

3.261125 

3.263625 

3.266125 

3-268625 

3-271125 

3.273625 

2.33 

3.4045 

3,4115 

3-4325 

3.4535 

3,4675 

3.4815 

3.541 

3.579545 

3.64 

3.656 

3.745 

3.8 

3,803 

3.805 

3,860 

3.908 

3.9168 

4- 


6-21 
6-22222 

6-25185 

6-254167 

6.28146 

6.31111 

6-321458 

6.37037 


MC/KHZ 

WC/HHZ 

4.0457 

6.380416 

4.096 

6.330833 

4,1153 

6.381041 

4.1299 

6,381666 

4.26 

6.3B229! 

4.335 

6.382916 

4.6895 

6.383541 

4.6965 

6.384166 

4.7175 

6.384791               , 

4.7245 

6.385416 

4.7315 

6,42963 

4.765 

6,43104 

4.89 

6.4592b 

4.9037 

6.47 

4.93333 

6.47111 

5. 

6.48889 

5.13125 

6,537 

5.139583 

6.567 

5.147917 

6.57778 

5.164583 

6.582 

5-1755 

6,612 

5.1768 

6.627 

5,25926 

6.6645 

5.3037 

5.33333 

6.673 

5.34815 

6.693 

5.3484 

6.705 

5.426636 

6.723 

5.436636 

6.7  305 

5.456 

6-738 

5.4675 

6,75 

5.499 

6,75125 

5.5065 

6.753 

5.1111 

6.7562 

5.5215 

6.7605 

5.544 

6.7712 

5.5515 

6.77625 

5.559 

6.7833 

5.5665 

6.81482 

5-574 

6-87407 

5.5815 

6,9037 

5.58519 

6.844444 

5.589 

6.88 

5.604 

6.91 

5.6115 

6.92 

5.619 

6.933333 

5.6265 

6.94 

5.62963 

6.96296 

5.6415 

7.01 

5.6715 

7.125 

5.68 

5-7037 

7.225 

5-7105 

7.25 

5.733333 

7.255555 

5.74815 

7.27  5 

5-80741 

7.3435 

5.83704 

7.35 

5-85135 

7,36296 

5,8968 

7,3728 

5.92593 

7.39 

5.9525 

7,42222 

7.443 

6. 

7.4585 

7.4615 

7.4685 

7.4715 

7.473 

7.4785 

7.4815 

7.4985 

7.62963 

7,65926 


NOTE  lOOKC  is  $9.99  each 


■ 


206     73  Magazine  ■  December,  1980 


f 

CRYSTAIS 
$4,99 

MC/MHZ 

MC/MHZ 

MC/MHZ 

MC/MHI 

7.67407 

10.8864 

23,575 

35,14 

40.62963 

7.68889 

10.962 

26.375 

35.18 

40.66666 

7,71852 

11.005 

26,62 

35,  19 

40.703704 

7.7985 

11.055 

26.64 

35.2 

40,740741 

7,f^015 

11.  13 

26. 66667 

35.3 

40.77777 

7.81 

11.1805 

26.67 

35.36 

40.814815 

7.9 

11.228 

26.7  4 

35, 55555 

40-85185 

'                              7.925 

11.2995 

26.8965 

35.90125 

40.888SS 

7.926667 

11-34 

26.958 

35.97625 

40.96296 

7,95 

11.3565 

26.965 

36. 

42.59259 

7,975 

11.50875 

27.005 

36.04 

45. 

8. 

11.53375 

27.04  5 

3  6,08 

46,2 

8,002 

]  1  ,55347 

27,095 

36,16 

48.98333 

8.003333 

11,705 

27.  126 

36.2 

8,0355 

11.755 

27,  185 

36.2675 

8.0835 

11.805 

27.205 

36.3525 

8.04864 

11.855 

27.22  5 

36. 3875 

MC/MHZ 

B.l 

11.90  5 

27,5 

36,4275 

8,123 

11.955 

27.7 

36.66667 

48. 927  7  7 

8.126 

11,96125 

27.77778 

37. 

49.21389 

8.12625 

J2.925 

27.84S 

37.2175 

49,692 

8vl4 

12,93 

27.9 

49.95 

8.15 

13.  102 

28. 

37.46 

53.45 

8.15571 

13.2155 

28.615 

37,77777 

53,3 

8,  15714 

13.2455 

28,7 

37.845 

56.9 

8.175 

13.2745 

28.728 

38. 

58.794 

8.2 

13.2845 

28.775 

38.33333 

8.284615 

13.2945 

28.8 

38.77777 

60.45 

a.  364 

13,3045 

28.805 

38.88888 

61,25 

8,42308 

13,3145 

28.835 

38.88889 

61.95 

8.5266 

13.3245 

28.855 

39. 

66.66667 

8.625 

13.3345 

23.88889 

39.  16 

67.52 

8.82 

13.3445 

28.905 

39.51851 

67.82 

8.82S5 

13.3545 

28.93886 

39.55555 

67.  94 

8,837 

13.824 

29.896 

39.592593 

68.  1 

8.8455 

14,315 

29.9 

39.629630 

68.  12 

8,854 

15.02 

30. 

39. 566667 

68,18 

8,8625 

15,016 

30.25 

39,703704 

68,375 

8.871 

15,03  6 

30,662 

39.74071 

68,48 

8.8795 

16,965 

31. 

39.777778 

68.60 

S.888 

17.00925 

31.11111 

39.81481 

71,015625                              1 

8.905 

17.01018 

31.66667 

39.851852 

72,8  55 

8.9135 

17,015 

31,9 

39, BBBBS 

73.50 

8.9305 

17.065 

32. 

39.92592 

7  5.185 

8.939 

17,115 

32.005156 

39.952963 

76,66667 

8.956 

17.165 

32.  175 

40. 

82.75 

9,0265 

17,215 

32.22222 

40,037037 

83. 

9,327778 

17.28 

32.6 

40.074074 

84. 

9,36 

32.936 

40.111111 

90.833 

9.37491 

17.9065 

33. 

40.14814 

93.1346 

9,425938 

17.9165 

33.3 

40,222222 

93.535 

9. 5075 

17.9265 

33,33333 

40.25925 

93,9353 

9,545 

17.9365 

33.44945 

40,29629 

94.3 

9.555 

17,9465 

3  3,9 

40.33333 

102.2 

9.565 

17,9665 

34, 

40.37037 

106.85 

9.585 

17.975 

34.245 

40.407407 

115.83 

9.643125 

17.9935 

34.44444 

40.444444 

121.5 

9.65 

18.29 

34.565 

40.48148 

126.4 

9,657292 

18.76563 

34.585 

40.51851 

1 2  8 . 

9.7 

19.006 

34.605 

40.555556 

146.64 

9.75 

19,1 

34.625 

40.59259 

147.09 

9.8 

19.1003 

34.655 

9. 85 

19.100308 

34,685 

<nkMf^^ 

Ww^ 

9,9 

19. 103394 

34.695 

Jztwm^m^ 

l7j 

9.934375 

19.3483 

34.705 

fh/WK  M 

■  Md    ^^^ 

9.95 

10 

10-01 

19,3484 

19.43125 

19.45208 

34.725 

35, 

35.02 

TOLL  FREE  # 

^^-*  electroqic^ 

10,02 

19,5385 

35.03 

(800)  528-0180 

10.021 

10.20833 

10.04 

19.6608 

20,1 

22 

35,04 
35.07 
35.08 

(for  orders  only) 

(602)242-8916 

10.3  55 
10.8037  5 

22.22 
23.25 

35,11 
35.12 

2inW.Camelback 

Phoenix,  Arizona  85015 

y^  Reader  Service — see  p^g&  22S 


73  Magazine  •  December,  1980     207 


*^12 


P.O.  Box  40I244-E         Garland,    TX.    75040         (214)278-3553 


Lfinlled  Qly, 
Limft  5  of 
each  type 

per  customeT 


RF  POWER  TRANSISTORS 

2N5591    25  W  @  13.6  VDC 

to  240  mhz  minimiim 

gain  4  4  db. 

6.95 


2146081  /  MRr221 

15W  @  t3.6  VOC  lo  240  mhz. 

Minimum  gain  8.3  db, 

4.95 


Units  are  marked  with  special  mtg's,  part  number,  however, 
flii  are  new  and  guaranteed. 


TO-3  P.C,  BOARD  HEATSINK 

Perfect  for  power  transistors,  or  309 
and  340 K  series  voltage  reguialor^. 

3/1.10 


■i^ifi' 


LM39S  Htgh  gam  power  rrartsistor  with  buitt  in  CLirrent 
limiting,  power  limitmg  and  thermal  overload  making  it 
virtusiiy  tmpossthte  to  destroy  with  overload, VCEO  = 
36V  IC  ^  2A  HFe  3000.  Will  dnve  direetry  off  TTL 
and  CMOS      1.65 


TRANSFORMEA 
;oo<J  1tftPi*tormtf  lorTfL  fittear. 

ComrmcKon'  OtwiFrmw/Mtfmig.iiinFB 

l«*flt 

Order  Brr-^DOS 

S2.95 


200V  4A  SCR 

Sensiltve 
Gale 

7/S1  00 

Special  P  Lirchase  -j  ^ 
Order  BES-0025  *'  ^ 


THE  PERFECT  TRANSFORMER 
117V AC  primary.  12VAC  secondary  @  200ma 
Great  tor  all  you  CMOS,  or  low  power  TTL 
projects.  PC  board  mount. 

99e  ea.       a/$2,5e 
Size.  1.5^  Wx  1  25''  Dx  l  25"  H 


Ay3-agio  programmable  sound  geheratob 

TITO  AY3-S910  IS  a  40  pin  LSI  chtp  with  thre«o^iikaior»,  Jhree 
amplitude  cootrofs,  programmaWe  noise  ganerjitor,  Itiree 
rrjlxefs^  an  envelope  generator,  and  three  O/A  converters  that 
are  coniroMed  by  fi  BIT  WQftDS.  No  vxmrnai  pot&  ot  caps 
rcquirefi  This  chip  hooked  Jo  an  S  bit  microprocesSOf  chip  qf 
Buss  {BOSO.  ZBQ.  6B00  ^c  }  cafi  be  soflwafe  conTr(>lled  to 
produce  almpsl  any  ftotjnd  II  will  ptay  throe  note  ChOfds.  make 
ban^.  tAhislles,  s  if  ens.  gunshotik.  «xpfoiJkoflft.  ble^fitB.  whines. 
Of  grunts  In  addilmn.  it  ttm  pn>vi3iofa  To  cootrol  fts  own 
frve«nory  ctiips  with  two  lO  ports  The  chip  requires  »5V  @ 
7*?fTia  4nci  a  standard  TTL  doc*  osciitaior  A  ifuty  incfeeliliie 

$14,93  W/Basic  Spec  5t>eet  (4  pag^) 
SD  page  manual  with  S-100  imedaee  instructions  and 
several  i^irogramming  exam  pies.  S3.00  extra 


OVP'*  OV£R VOLTAGE  PROTECTOR      6,95 

Providers  cheap  insurance  for  your  expensive  equfpmefiL 
Trip  volta^  is  adkistable  from  3  to  30  volts.  Ouefvnitage 
instanttv  fires  a  25A  SCR  and  shofis  ttie  output  to  protect 
eqyipmflnt.  Should  be  u«ed  on  units  that  are  fused.  Di- 
rec^iy  compaiible  with  the  PS  12  and  PS'14.  All  electron- 
ics sutJpliod.  DriFled  and  plated  PC  b&ard. 


ULTRASONIC  RELAY  KIT 

tnvi^tble  Beam  Wortcs  Like  A  Pholo 
EtectricEye  COMPLETE  KIT  All  Parts  a 
PC  Board  Use  Up  To  25  Ft  Apart 

Optional  eniry  delay  and  Alarm  Timeout 
Circuil  Will  sQurce  or  sink  up  to  2<Q0  MA 
DC 

S3dS 


AUTO A^ AN  CLOCK  KIT 


•  12  Hr  Format 

•  6  Digit  6'^  LED  Readouts 

•  Quart/  XT  AL  Timebase 

•  A^arm  &  Snooze  Options 

•  Noise  Fillenng 

•  Easy  Assembly  •  12  VOC 

•  4  5/a"  it3"  X  1  1/2" 

•  All  Pans! 


$t6JS 


'      ZULU  II  CLOCK  KIT 

X'TRA  VALUE ^  All  Ihp  [:r3mpqri4f<n1i^  and  fiigh  qu^Mty  picilFd  G*1D  PC  Qanretii 

Fire  rif'^itli'ii 
K-TRA  CAaE  \H  0£SlC»Nr  Easy  Assembly!  Large  open  iayOul 
X-CEiLENCE  IN  IDEAS:  5  yfiflfs  of  design e?cJ  prodticfs  'or  mw  BmiihjLrr  radio 

X-CELLENCE   IW   INSTRUCTIONS:  Clear  step- by  stop  in^tmtiionn  with 

nUHiity  iilii».rr^ih.-iri:i  (iriit  ■jt^hemftidC- 
K-TnA  FEATUnES'Th^iehn&rteverbeeiTaclEMikkFt  with  SO  many  feaiuFiti—  nt 

any  pf^^^ 

•  Unir  opoiatr*  Ofi  et»nt5r  t!  VAC  o'  11  VDC- 

•  Oti  t>oaro  OUAATZ  KTAt  TJMESASE  «f  60Hz  AC  \m^  heq  cvi  |?e  used 

•  AuTomaric  DATTERt  SAC  HUP" 

•  Reod^  \iu*  ^  HOUR  TIME  .v  z  3t  DAY  CALENDAR 

«  Uniqu*  NO  X  ^    CIRCUIT  »cin>  ftt«s  readouts  with  a  Korvdca  ip  tDllQwvd  bf  the 

dadc  lor  4  HKondi^  Or  lh«y  tan  Ck  tnim^  a<i  C!«n$tartOy. 
«  fipten  b»M<l  tiiobt)«  rapdOiiA  1}isnh  whe  igntiion  a  off 

•  Special  NOtSC  SUPWiClSHHI  af^  tjattEf  y  nmenal  cif  cuttx 

•  Bffgftt  t  ?    Lrp'n  nNi*  hotm  ri«PtJ'e  a-nt?  iMccoflds ^_ 


WITH  CALEMDAR 
AMD  NOX^-CtRGUIT 

19.95 

LESS  CASE 

ACCESSORIES 

Cuifom  High  Impitri 
MaTded  Ca^  with  Ruby 
Lefi$.  Avstlftbta  In  B1u«  of 
T». 

Sfi.50 

TIT  VAC  to  ta  VAC 
Traaslomrier- 

$1.35 
'9V  Bast^y  Noi  lofLirM^e 


*w 


Sound  Effects  Kit    $18.$0 

TTie  SE-01  Sovntf  E  rfcctai  K  fl  i»  «  comftW*  N  LL  au  you  n««d  ta  Duik}  « 
ptogranvna&ifr  ^d^n  ^  sh^ds  marine  ev£:e^  a  baflery  snd  ipfl«li;«r 
Oiir  kit  ij  de$ig(wd  (o  r«aNy  rmg  oul  Ihe  Tl  75477  Souths  Ch*  Ofrty 
ihe  5E-Dtt  pTQirides  you  with  «kliii«n«i  ciraiifry  llu^  m^tlH  a 
PULSE  <^M3iATOfl,  MUX  OSaLLATOR  and  COMPftflfTOll  lo 
make  mwe  csmptvit  foiindrl  i  *rLap  V.  t  .it.;,  ,  -„  ,.,  u.iidjng  th«  kit 
wifh  a  cl«af.  eMy-ti>- fQllsur  con^ifucfion  manmal  and  ivesriow  you 
how  ID  easily  pfogram  rheunit  Oihardfu^rswid  sejiyoiirhechipm 
□  'kil"  ort  (^Ms  bul  you  itre  on  your  own  to  do  ins  mosi  dittieutl 
part  mak*  rteftt  toufidt'  Witftkn  ii&heH  tfmeafie*  yc3Li  Mjrldih^SE'Oi 
you  can  easily  crciatf>Gunih&it.  Eiploikira.  Space  SDundS',  StHm 
Traau  and  much  rtiDta  W#|h>»nk  theBuUet  SE-Ol  is  the  ^esrdisalcin 
ite  maT^^ot  btJt  tforr't  uk  ut,  -  «sk  thfl  15.000  hgppy  SE-D1  ownefa^ 

CDmp4Ble  KJI  Wilh  Quality  Platfld  PC  Board  S1B,50 

tina  baltory  &  «p«aKef) 

U9«ri  Group  Noln:  fnctud^s  addJlJonat  pfrt>grQmmiing 

charts  plurj  quhltflrly  iipdates  $5.00 

y  UjfATT  AUDIO  MAV  KIT 
SMALI,  S1N0I.E  HYBPtlD  \tl  AND  GOMPONENTS  FIT  ON  *  2"  k  3"  PC 

BOARP  iPNCLUI3EDl  RUNS  ON  UV DC  GREAT  FOR  ANV  PROJECT  THAT 
NEEOS   AN    INEXPENSrve    AMP    LESS   THAN   3%  THD  <S^   5  WATTS 
COMPATIBLE  WiTM  SE-r^l  UOUND  WT  t&US 


PARTS 

LM3048  [CA3CH6)  ^islqr  Arr^y 

ItCA  40400      4aDV  fiA  TBIAG  TQ-C6  . . . . 

LUHT  Ton*  Dacoder 

GO4046  PLL  CMOS 

L1I3302  Quad  CompqralLit 

jrSC  IMt        Hi^h  FfKl  NPIH  TO-02 

m^S  A  20        NPN  G«n^al  f^urpo3«   

TL490  Bar.' Graph  Dtvwm  iw^specs 

7V12  12V  1 A  neoyialo« 

71^  SV  )A  R#qute1ar  .. 

TflMOS  SV    A  Rs^  TO-?  fHse  #T 

LM391I  Tafnp  Tranidiuca<^w  £p^r3 

S5S  Ttmar  IC  ....... 

P,UT  w/ipeo     --. 

Opto  l40i4lCHr  vrsiiec!^   

2W  Auci*i?  fC  w<ipa»  . 

CXfti^  Licaeo  iM/spacs  .  .     . . 

PUP  Ptmv  10-zm 
sen  Sectiitivtr  GaJ©  200V  4*   . . 

SCR  San^ritye  Gate  flODV 

4AnCA     

iM2n  variAblt  Reg  3-35V  1A 

vi^ipsa  ...,,,  

TriQ^wr  dicidEr  tor  tnacs  tn 
01AC  AC  phua  control 

nnfffiTsiJi-ifi  ,...,.... 


1^1  JIO 


1.69 


n 


*       CALL   OH    WHITETODAY   FOR    FREE    CATALOG       * 


MO  CO  D 

SEND  CHECK.  M,0,.  OR 

CREDIT  CARD  U 

PHONE  ORDERS  ACCEPTED 

ON  VISA/MASTER  CHARGE  ONLY 

{214)  278-3553 


ADD  5%  FOR  SHIPPING 
ORDERS  UNDER  $10  ADD 

75  HANDLING 
TEX.  RES  ADD  5%  TAX 
FOREIGN  ORDERS  ^EXCEPT 
CANADA)  ADD  10%  (20%  FOB 
AIRMAILS 


t*^  MUSIC  FOR  YOUR  EARS 

BiitUit  s  EteclronJc  Music  Machine*  Kit  hn^  a 
single  2t  Pin  Microproc^sor  Chip  with  ROM 
thai  has  b«en  program  meet  sa  ptay  The  Iksi  6  lo 
to  nG\e9  Qt  ihe  25  popular  lur>s  listed  below 
Each  luR«  can  easily  be  address^  itHti vidua Ity 
or  p^ayiKf  sequenciaily  ai  the  pifsai  oi  a  button 
Ttte  S  chtme  seq  uen  c^s  ai e  aci  iv  aled  at  any  ti  me 
tjf  separate  switch  closures  so  wtien  used  as  a 
doorb«IL  Ofw  <tQOf  can  play  songs  whil«^  iwo 
others  Witt  piav  ditfef  enl  ^^imcs  The  uhn  has  a 
5  waft  autft>  Amp  and  wM  run  en  either  12VAC 
or  12 VOC,  Optional  117VAC  liari&fotme^  ^ 
available  Const rucl ion  is  veiy  sjmple,  wdtlis 
with  any  0.  or  16  ohun  speaker,  oe  ti&m  $pe^k?r 
\tiol  liiclud€K3 )  Tunes  can  be  reniolr  , 
piogrammed  usvn^  a  single  rol&ry  ftwHch.  |nd1 
ihctuded).  il  desired. 

CompIHe  Kill     SIS^^S      TransformeT     S1.3S 

For  ClpcMalttnn 
on  117VAC 

Tune»:  Tor^^dor  '  William  Tell  '  Hal^e^uiah 
Chemt  *  Star  Spangled  Banner  "  Yanke« 
Doedic!  '  America.  America  "  Deufschtand  Leid 
'  Wadding  Mafch  *  Beethoven  s  Sth  and  91  h  * 
Heiri  Betia  -  L aVIen  En  Ros?*  Star  WarsTh^me 

*  Ctefnenllno  '  Augustine  '  Jingle  Bells  '  Cod 
Save  The  Queen  '  Colonel  Bog«y  *  Md^sei liaise 

*  O  Sole  Mio  '  Santa  Lucia  '  The  End  "  Blue 
Dan  u be  '  B rahms  L  u Kaby  '  W estm ini  si  er  Chime 

*  Sample  Chim«  "  Desceniiing  Octave  Chi^me 


2M     73  Magazine  •  December.  1980 


The  Greatest  Breakthrough 
in  Electronic  Music  I 


Introducing 


The  New 


SUPER  MUSIC  MAKER  KIT 


Commercial  Pis|»lays 


'€%i 


Doorbells 


$23.50 

Less  Speaker 


.^ 


Musie  Bonu 


Car  Horns 


Super  Music  Machine  Kit  $23.50 

PC  board  only  for  Super  Music  Machine  $5.00 

Basic  Kit  less  IC's  $11.50 

DIP  Switches  for  PC  Board  (2)  $2,00 

Blank  2708  EPROMS  (Not  programmed)  $9.60 


AT  LAST:  An  affordable  kit  that  can  be  programiYied  to  play  any  song  or  group  of  songs  you 
desire.  Instead  of  a  nightmare  of  numerous  IC's  and  special  expensive  bi-potar  ROM's,  theSuper 
Music  Maker  uses  a  special  mask  programmed  computer  chip,  one  CMOS  gate  and  the  most 
popular  erasable  EPROM,  the  2708/2716  series.  The  basic  kit  includes  drilled,  plated  and 
screened  PC  Board.  All  components  are  provided  except  the  EPROM  and  12V  transformer.  The 
basic  kit  will  play  short  renditions  of  25  tunes  through  its'  7  watt  amplifier  section.  With  the 
addition  of  an  optional  ROM  any  tune  that  is  programmed  can  be  played!  If  you  have  the 
equipment  to  program  2708  EPROMS  we  supply  full  information  on  programming  your  own 
music,  if  you  wish  to  buy  ROMS  with  tunes  pre-programmed,  we  have  arranged  with  another 
company  to  provide  this  service.  MASTER  MUSIC  in  Mt.  Vernon,  Missouri  is  stocking  a  large 
inventory  of  preprogrammed  ROMS.  If  a  Super  Music  Machine  Kit  is  ordered,  a  listing  of  available 
ROMS  and  ordering  information  will  be  included  with  the  shipment. 


FEATURES: 


*  The  basic  kit  contains  25  "short"  tunes,  in  the  main  IC. 

*  Will  address  external  ROM  for  up  to  1,000  more  notes  per  ROM,  (ROM  IS  NOT  INCLUDED!) 
+  Operates  on  12  volts  AC  or  12  volts  DC*.  @  500  ma. 

*  7  watts  of  audio  power  witi  drive  8  or  16  ohm  speakers  or  horn  speakers.  {Not  Included!) 

*  "Next  Tune"  provision  steps  sequenciaMy  through  all  tunes. 

*  Tune  address  can  be  wire  jumper  selected  or  board  is  designed  to  lake  DIP  switches,  {available  seperately). 

*  Pitch,  Volume  and  Tempo  are  al!  adjustable. 

*  Special  "chime"  sequences  can  be  activated  regardless  of  tune  address  to  provide  for  multiple  doorbell  applications. 

*  All  tunes  consist  of  electronic  musical  notes  played  one  at  a  time.  There  are  no  chords  or  harmony  sound  to  the  music 

*  Step-by-step  assembly  instructions  provided.  90  day  parts  warranty,  complete  repair  service. 
'Using  unit  on  12  vofts  DC  and  with  option  ROM  requires  9V  bias  battery,  (not  included ). 


ftVLLIT  ELECTB«IIC9 


1^12 


P.O.     BOX     4  01244'-E 
GARLAND.    TX.     7  6  040 


n 


THIS    KIT    IS    IN    STOCK.        YOU     WILL     LOVE     OUR    FAST    SERVICE!    ^^ 
SEE     OPPOSITE     PAGE     FOR     ORDERING     INFORMATION     i     POLICIES. 


^  Reader  Service— ^&e  page  226 


73  Magazine  •   December,  1980     209 


*       T       -1^      »       V 


fff 


NEW  RADAR  DETECTOR  BOARDS 


t*1  -  Includes  3  -  741  op  amps.  1NE5S6 

Timer,  and  1  -  LM31 1 


S  2/1.00 


fi2  -  Includes  1  -  NE567  PLL.  1NE555  S  -75  Each  of  3/2.00 

Timer,  1  -  5634  Low  Noises  op  amp  for 
high  quality  audio^  2  -  741  op  amps, 
and  1  -  78M08  voltage  Reguiator:  8V 
500MA 

Each  of  these  boards  contain  many  other  parts  too 
numerous  to  list. 


CUSTOM  IC         #17564-4 
Has  a  C-MOS  oscillalor.  Decade  Counter  Decoder/ 
Driver  Al  Ihe  push  of  a  button  will  flash  a  LED  24  times. 

At  the  end  of  which  it  will  display  the  number  of  times  it 
has  gone  through  the  cycle,  up  to  99  Variable  speed 
pulses  -  Perfect  tor  timing.         FULL  DATA  —  $1.00 


fi 


v.* 


*   4f   -k  it  ^   i(  CABLE  TIES  ****** 
MAKEYQURPR0JECTS"NEAT&TIDV'4"  CABLE  TIES  AT 
A  FANTASTIC  PRICE.  GET  THIS  BARGAIN  AND  "TIE"^  IT 
DOWN         S2.00  for  100  or  better  yet  $15,00  for  1000 


Yicleo-^lleu 

SEND  FOR  CATALOG  ^js  tm 


t««4 


SEND  FOR  CATALOG 
WITH  SUPER  SAVINGS!! 

Introductory  Offer 


41^^ 


A  Full  Color*  TV  Game  For  The  Family 

Six  eKciling  TV  Games  —  Hockty  Tennis  and  Handball  with  one  Of  iv#o 
ptayer  capability  for  each  game  Bait  velocity  double  after  the  fourth 
player  hit  for  an  mcreasmgly  compeiitive  §ame 

AdjLrstdbte  paddli^  size  for  each  pfayer  allows  for  handicapped  play  ^f 
desired  Paddles  can  grve  automaiiC  ball  spin  wiih  seven  possible 
angles  ol  ball  deflect fon 

Automatic  dignai  scoring  appears  after  each  point  is  scored  Game 
ceases  automatically  after  one  player  -cores  15  points.  Sen/mg  is  from 
Ihe  paddle  of  player  who  scored  the  last  points  thus  server  can  'plate" 
his  shot 

Video-Volley  is  designed  to  be  msialied,  with  a  mmimum  of  effort,  to 
any  standard  television  receiver,  either  color  or  black  and  white 
Batteries  bt%  rtot  required 


l«i 


^••*** 


OPCOA  CLOCK     #R1200  AC 

12  Hour  Format.  12  Volt  Operation.  .3  Inch  Display.  Has  Radio 
(Alarm)  Output.  Complete  with  On-Board  Switches  and  4  Pin 
connection  for  easy  hook  up.  With  Data. 

Add  60Hz  TirriQ  Base  for  DC  Opofalion, 

SUPER  SPECIAL  2/8.00  or  S4:2S  each 

Plug  in  transrormer  and  all  parts  to  make  clock  operational  S2,20, 


::::::  $795 
i;::::      ■ 


VERY  LIMITED  STOCK! 


M3-650t 

256  By  4  CMOS  Ram,  By  Harris.  Super  Low  Current  Drarn* 
Data  retentron  Voltage  2  Volts.  Great  for  battery  power  or 
back-up, 

$1.99  each 


5  VOLT  REED  RELAY 

An  ablsoluteiy  fantastic  ftem.  Compare  this  price  with  any 
advertiser  While  They  LastI  Normally  Open.  SPST.  Turns  on 
at  10  MA,  Drops  out  at  5  MA, 

SUPER  SPECIAL!  2/1.20  or  10/4.00 


*■ 


»• 


At 


•• 


»■ 


•  i 

#11 
*m 


Small  hand-hetd  playef  modules  with  tS  foot  cord  length  pron^ides    ^ 
more  comfoft  and  versatility  for  player^  ^ 

The  compaci  command  module  stls  atop  the  lelevision  receiver  artd 
has  front  panel  control  allowing  effortless  change  from  normal 
television  recephon  to  game  play  Easy  disconnection  of  the  player 
hand-Kpid  modulss  facilitates  easy  sei-up  and  take-dr^^Am  for  storage     — 


*• 


-.i 


'••f 


^•••«- 


i«« 


t#«*< 


LAB-BENCH  VARIABLE    $12  00  KIT 

POWER  SUPPLY  KIT        super  sale 

5  to  20  VDC  at  1  AMP,  Short  circuit 

protected  by  current  limit.  Uses  tC 
regulator  and  10  AMP  Power 
Darlington.  Very  good  regulation  and 
fow  ripple.  Kit  includes  PC  Board,  all 
parts,  large  heatsink  and  shielded 
transformer  50  MV,  TYP  Regulation. 


RCA  SENSITIVE 
GATE  TRIAC 

TO-5  CASE,  HOUSE  #40531 

ALSO  SAME  AS  T2300a 

2,5  AMPS  400  PiV 


5/$1.19 


Perfect  for  Dimmers, 
Color  Organs,  etc. 
PC  LEADS 


NATIOHAL  SEMICONDUCTOR 

"COLOSSUS  JR/'  JUMBO  CLOCK  MODULE 


MA1013 
BRAND  IMEW 


WJ§^ 


r««- 


AtSEIIBLED'  NOT  A  MlT> 


V^ANUFACTURERS  CLOSEOUT! 


$8,50 

(•s«) 

I  AC  KfMFi  $1  ^^ 


PERFECT  FOR  USE 
WtTH  A  TIMEBASE 


Bri^hl  4  dKigEr  0  T    LCD  1>t:Splay 

CompivTe-Add  emit  TtansrorTTifr  ifitf  Swilchps 

24  Hour  Alarm  ^nal  Output 

12  H&uf  R#«t  Tt«vr  formal 

SO  or  60  H2  Op«fAl^Dn 

Powtr  FihlutF  IndicaMon 

LED  Brighlneii  Cdntrol 

Sie?p  and  Srtooie  Timers 

Alarm  '  on  '  4ind  PM  Indieatart 

Difflcl  Drive     No  RFI 

DiFflcl  Rfplicetnenf  loi  MAtOl2 

Comes  wilh  FuH  Dulfl 


SPECIAL  1  MONTH  ONLY! 
S3.95 

SO  Hi  CRYSTAL  TIME  BASE 

(Complefe  KH) 
Us«5  MW53e9CMOS  'itvidflr  iC  with 
liigh  accuracy  3  579^45  MH2 
Crystal  U^  witli  ali  MOS  Clock 
CMps  or  Moc^ules  Draws  only  1  5 
MA  All  parts,  d^ta  and  PC  8oarcf 
tncluded  100  Hi.  same  as  above. 
^xc«pl  15.95. 


D.C.  HORN 

VERY  LOUDt 

6-12  VDC 

Like  Used  In 

Smoke  Alarms. 

FANTASTIC  SAVINGS 

Compare  this  true  value. 

.60  ea.     4  For  $2.00 


PMD-11K-60    (Darlington) 

60  Voils.  HFE  800-20K 
12  Amps,  PNP  TO-3 
160  Watts.  By  Lambda,    gf^l^Ht) 

$1.50  Me>wi 


Crystal 
Super  Savings 

4,433618  MHZ 
2/$1.10 


REPEAT  OF  A  SELL-OUT! 

VECO    PREClSlOISr    THERMISTOR     GLASS    TYPE     VECO  * 

#4VA72    a2K   OHMS  AT  ROOM   TEMP    VERY  SENSITtVE  !;| 

iNDIVJDUALLY  PACKAGED  IN  PLASTIC  VIALS  S3  00  VALUE  -4 

$1.00  each  or  3  FOR  $2,50  -H 


Digital  Researcli:  Parts 

**  (OF  TEXAS) 

P.0,  BOX  401247  •  GARLAND.  TEXAS  75040  •  (214)  271-2461 


TERMS:  Add  iOC  posuge.  we  pay  balance  Orders  undei^  $^S  add..« 
Iht  handling  No  COO  We  accept  Visa.  MaslerChafg*?  and-** 
Americart  Express  cards  Tex  Res  add  S^  Tax  Foreigr>  orders  "'• 
(except  Canada)  add  20%  P&H  90  Day  Money  Baci^  Guarantee  ort  *!* 
all  If  ems  •  • 


m       *       w      * 

*      *      * 


m       m      m      ^       ^F 


«  *  •  « 


•  * 
«  • 


•     «      www*      m      »■••••♦*•••*    '^  •     ' 

^  m  m  m  m  *  m  *  *  *  •  •  %  9  9  9  9  9  •  \*^ 


•  ♦•••• 


These  Low  Cost  SSB 

TRANSMITTING 

CONVERTERS 

Let  you  use  inexpensive  recycled 
lOM  or  2IVI  SSB  exciters  on  UHF  &  VHFI 


Linear  Converters  for  SSB,  CW,  FM,  elc 

A  fraction  of  the  prfce  of  other  units;  no  need  to 
spend  $300 -$400! 

Use  wrth  any  exciter^  works  with  trtput  levels  as 

fow  as  1  mW. 

Use  low  power  tap  on  exciter  or  sample  resistor 

attenuator  pad  (instructions  included). 

Link  osc  with  RX  converter  for  transceive. 


XV4  UHF  KIT  —  ONLY  $99.95 

28-30  MH;;  in,  435-457  MHz  out;  IWp.e.p.  onssb^  upto 
WiW  on  CW  or  FM.  Has  second  oscillator  for  other 
ranges.  Aiten.  supplied  for  1  to  500  mW  input,  use 
external  attenuator  for  higher  f  eve  Is. 

Extra  crystal  for  432-434  MHz  range S5,95 

XV4  WSred  and  tested  .......... $149.96 

XV2VHF  KIT -ONLY  $69.95 

2W  p.e.p.  Output  with  as  littie  as  1  mW  input.  Use  simple 
external  attenuator.  IVIany  freq,  ranges  available 


MODEL 

XV2-1 
XV2-2 
XV2-4 
XV2-5 
XV2-7 


XV2  Wired  and  tested 


INPUT  {WlHz)  OUTPUT  tWHz) 

28-30  50-52 

28-30  220-222 

20-30  1  44^1  48 

28-29  (27-27.4  CS)1 45-1 46  (144-1 44.4) 

144-146  50-52 


XV28  2M  ADAPTER  KIT  -  $24.95 

Converts  aray  2h/1  exciter  to  provide  ihe  lOM  signal 
required  to  drive  above  220  or  435  MHz  units. 


■i.-.^ti^_^l^ 


NEW!  COMPLETE  TRANSMiniNG  CDNVERTER 
AND  PA  IN  ATTRACTIVE  CABINET 

Far  less  than  the  cost  of  many  10W  units! 

Now,  the  popular  HafBtronics*  Transmitting  Converters 
and  heavy  duty  Linear  Power  Am  pi  f  tiers  are  aval  fable  as 
complete  units  in  attractive^  shielded  cabinets  with  BNC 
receptacles  for  exciter  and  antenna  connections.  Perfect 
setup  for  versatileterrestfal  and  OSCAR  operations!  Just 
right  for  phase  3?  You  save  $30  when  you  buy  complete 
unlit  with  cabinet  under  cost  of  individuai  items.  Run 
40-45  Watts  on  VHF  or  30-40  Watts  on  UHF  with  one 
integrated  unilJ  Call  for  more  details 

MODEL  KIT 

XV2/LPA2-45/Cam  (6M  or  2M)    $1  99.95 
XV4/LPA4-30f^Cabt  (for  UHF)       $229,95 


WIRED  and 
TESTED 

^299.35 
$349.^5 


Easy  to  Build  FET 

RECEIVING 
CONVERTERS 

Let  you  receive  OSCAR  and  other 

exciting  VHF  and  UHF  signals  on 

your  present  HF  or  2M  receiver 


NEW  LOW-NOISE  DES[QN 
ATTRACTIVE  WOODGRAIN  CASE 
Less  than  2dB  noise  figure,  20dB  gain 


MODEL 

GA28 

CA50 

CA50-2 

CA144 

CA145 

CA146 
CA220 
CA220-2 
CA110 

CA432-2 
CA432-5 
GA432-4 

Easily 

STYLE 

Kit  less  case 
Kit  witli  case 
Wlred/Tested  in  case 


RF  RANGE 


OUTPUT  RANGE 


28-32  MHj 

144-148  MHz 

50-52 

23-30 

5054 

144-148 

144-146 

23-30 

145-147-01- 

2B-30 

144-144.4 

27-27,4  (CG) 

146' 148 

28-30 

220-222 

28-30 

220-224 

144-148 

Any  2MH£  ot 

2  6 -2  a 

Aircratt  Band 

Of  28-30 

432-434 

28-30 

435-437 

28-30 

432-436 

144-148 

modified  for  other  rf  and  if  ranges. 

VHP 

S34.95 
$39,95 
$54.95 


UHF 

^49.95 

$54,95 
$64.95 


Professional  Quality  VHF/UHF 

FM/CW  EXCITERS 


Fully  shielded  designs 

Double  tuned  circuits  for  spurious  suppression 

Easy  to  align  with  buiit-in  test  aids 


IT'S  EASY  TO  ORDER!  .. 

m  Write  or  phone  716-392-9430 
(Electfontc  answering  service  evenings  &  weekends) 
m  Use  Credit  Card.  UPS  COD,  Check,  Mor^ey  Order 
•  Add  $2.00  shipping  &  handling  per  order 


T50-50  6-chan,  8M,  2W  Kit, ,,...,,...,,. $44,95 

T50-1 50  6-chan.  2 M,  £ W  Kit. $44,95 

T50-220  6-chan,  220  M Hz,  2W  Kit $44.95 

T450  1-chan.  450  MHz,  ViW  Kit , $44,95 


See  our  Complete  Line  of 

VHF  &  UHF  Linear  PA'S 


•  Use  as  linear  or  class  C  PA 

•  For  use  with  SSB  Xmtg  Converters,  FM  Exciters,  etc. 

LPA2-1  5  6M,  2M,  220;  15  to  20W ...  $59.95 

LPA2-30  6M,  2m;  25  to  30W $89.95 

LPA2-40  220  MHz;  30  to  40W $119.95 

LPA2'45  6M,  2M;  40  to  45W S1 1  9,95 

LPA4-10  430MHz;  10  to  1  4W $79.95 

LPA4-30  430MHS:  30-40W S11 9,95 

See  catalog  for  complete  specifications 

Call  or  WrFte  to  get 

FREE  CATALOG 

With  Complete  Details 

(Send  4  IRC's  lot  f)v^rmA&  maiNrgJ 
H  AM  TRO  N IGS    I S  A  REG  I STE  RE  D  TRAD  EM  A  R  K 


FAMOUS  HAMTRONICS  PREAMPS 

Let  you  hear  the  weak  ones  toot 
Great  for  OSCAR.  SSB,  FM,  ATV.  Over  14,000  in 
use  thfoug  hout  the  world  on  all  types  of  receivers. 


•  NEW  LOW-NOISE  DESIGN 

•  Less  than  2  dB  noEse  figure,  20  dB  gain 

•  Case  only  2  imches  square 

•  Specify  operating  frequency  when  ordering 

MO  DE  L  P-30  VH  F  PRE  AM  P,  a  va  i  lable  i  n  ma  ny  versions 
to  cover  bands  18-300  MHz, 

MODEL  P432  UHF  Pif EAMP,  available  in  versions  to 
cover  iDands  300-650  MHz. 


STYLE 

Kit  less  case 
Kft  with  case 
Wired/Tested  in  Gas© 


VHF 

$12.95 

$16,95 
$27.95 


UHF 

$10.95 
$26.95 
$32.95 


NEW  VHF/UHF  FM  RCVRS 

Offer  Unprecedented 
Range  of  Selectivity  Options 


New  generation 
More  sensitiye 
More  selective 
Lovw  cross  mod 
Usas  crystal  fi  iters 
Smaller 
Easy  to  align 


R75A*  VHF  Kit  for  monitor  Or  weather  satteiite  service. 
Uses  wipe  LC  filter.  -60dB  at  ±  30  kHz $69.95 

RTSB*  VHF  Kit  for  normat  nbfm  service.  Equivaient  to  most 

transceivers.  -60clBat  ±  1 7  kHz,  -e0dSat±25  hHz  . .  S74.95 

R75C*  VH  F  Kit  for  repeate  r  service  or  high  rf  density  area. 
-60dB  at  ±1 4kH2.  ^SOdB  ±22kHz,  -1  OOdB  ±30kH£, .  .  $84.95 

R7  S  D*  V  H  F  Kit  for  spS  1 1  c  ha  n  n  ei  o  pe  rati  on  or  repeater  i  n 
high  density  area.  Uses  8- pole  crystal  filter,  '60dB  at 
±9  kH3:,'1 00dBat±  1 5  kHz. Hie  ultimate  receiver!. . .  $99.95 

*  Specify  band:  1  CM,  6  M ,  2M.  or  220  M  Hs.  May  also  be  jsed 
tor  adjacent  commercial  tiarwds.  Use  2M  version  for  1 37  MHz 

WX  sateliites. 


R450(  J  UHF  FM  Receiver  Kits,  similar  to  R75,  but  for 

UHF  band.  Hew  low-noise  front  end.  Add  $10  to  above 

prices.  (Addselectivi^ty  letter  to  model  number  as  on  R75.) 


At 4  5  Channel  Adapter  for  Receivers. 


$995 


N  EW  R11 0  VH  F  AM  RCVR 


AM  monitor  receiver  kit  similar  to  R75A,  but  AM.  Available 
for  10-1 1 M,  6M,  2M.  220  MHz,  and  1 10-130  MHz  aircraft 
band  $74.95.  |Aiso  available  in  UHF  version^ 


miponics,  inc. 


65  J    MOUL  RD  -  HflTOW,  NY  1446b\ 


*^  Header  Senftce^see  page  226 


73  MagazmB  •  December,  1980    211 


2822  North  32nd  street, #1    •    Phoenix.  Arizona  85008   •    Phone 602-956-9423 


MEMORY 

Descript  ion 

Price 

MRFi+72 

12.5  VDC.   27  MHz 

2708 

IK  X  8  Eprom 

$   5.00 

k  Watts  output,    10  dB  gain 

2716/2516 

2K  X  8  5V   sing] 
IK  X  1*  Static 

e  supply 

9.99 
5.00 

$1 .69  each 

21IV911'* 

IK)27 

4k  X    1    Dynamic 

Ram 

2.99 

CARBIDE  CIRCUIT  BOARD   DRILL  BITS 

2H7An6 

)6K  X    1   Dynamic 

:   Ram 

5.00 

for  PCB   Boards 

2732-6 

32K  Eprom 

39.95 

5  mix   for  $5.00 

C.P.U.'s,   Etc. 

MURATA  CERAMIC  FILTERS 

SFD   4*550              k5S  KHz            $2.00 

MC6800P 

Microprocessor 

9.99 

SFB   (+550              1*55  KHz              I  . 

60 

MC68B2IP 

PIA 

6,99 

CFM   ifSSE               kSS   KHz               5. 

50 

HC68^5P 

CRT  Control ler 
ACIA 

25.00 
'♦.99 

SFE    10.7  MA        10.7  MHz            2. 

99 

MC6850P 

MC6852P 

SSDA 

5.00 

ATLAS   CRYSTAL  FILTERS  FOR  ATLAS 

8008- 1 

Microprocessor 

5. 

,00 

HAM  GEAR 

808OA 

Microprocessor 

5. 

,00 

5.52  -  2.7/8 

Z8OA 

Microprocessor 

10. 

.99 

5.595  -  2.7/8/U 

Z80 

Microprocessor 

8, 

,99 

5.6lf5  -  2.7/8 

Z80A 

PIO 

9. 

.99 

5.595  -   .500/VCW            YOUR  CHOICE 

Z80 

SIO/O 

22. 

.50 

5.595  -  2.7  USB                 $12.99  each 

Z80 

SIO/I 

22. 

.50 

5.595  -  2.7/8/L 

8212 

8  Bit    input/out 

:put  part 

3, 

.99 

5.595  -   2.7  L5B 

8251 

Communication    1 
UART 

nterface 

6. 
6. 

.99 
.99 

9.0  -  USB/CW 

TR1602/AY5-1013 

TMSIOOONL 

Four  Bi  t  Microf 

jrocessor 

k. 

.99 

J310  N-CHANNEL       J-FET     1*50  MHz 

PT11+82B 

PSAT 

5. 

.99 

Good  for  VHF/UHF  Amplifier, 

8257 

DMA  Control ler 
6U  X  i+  FIFO 

8, 
3. 

.99 
.00 

Oscillator  and  Mixers       3/Sl 

.00 

33M 

rtM5316/F38l7 

Clock  wi  th  alarm 

5. 

.99 

AMPHENOL  COAX    RELAY 

87J+I 

60, 

.00 

26  VOC   Coil      SPOT     #360-11892-13 

8748 

8  Bit  Microcomputer  with 

100  watts     Good   up   to   18  GHz 

programmable/  erasable  EPROM 

60. 

,00 

SI 9. 99  each 

HCTiOSl/S 

6  Bit   D/A 

3. 

.25 

C0H2502 

9. 

.99 

78MO5     Same  as   7305  but  only 

i  Amp  @ 

C0H2601 

9. 

l92 

5  VDC        kSt  each  or    10/$3.00 

CRYSTAL  FILTERS 

NEW  TRANSFORMERS 

TYCO  001-19880 

Same  as   21 9^ 

F-I8X        6.3  VCT  @  6  Amps 

$6 .  99 

ea. 

10.7  MHz  narrow 

band 

F-l»6X        2'*  V  ^   1   Amp 

5.99 

eds 

3   dB  bandwidth 

!§  KHz  min. 

F-UIX        25.2  VCT  ^  2  Araps 

6.99 

ea. 

20  dfi   bandwidth 

60  KHz  min. 

P-8380      10  VCT  ^  3  Amps 

7.99 

ea. 

kO  de  bandwidth 

150  KHz  min. 

P-8604     20  VCT  ^   1   Amp 

4.99 

ea. 

Ultimate  50  dB 

insertion   loss      1 

dB  max. 

P-8130     T2.6  VCT  0  2  Amps 

4.99 

ea. 

Ripple    1    dB  max 

.      Ct.   0+/-5   pf 

3600  Ohms 

K-32B        28  VCT  ^   100  MA 

4.99 

ea. 

$3.99  each 

E30554     Dual    I7V  ^   lAmp  ea. 

6.39 

ea. 

MRF^5^,    same   as  MRFi+58  12.5  VDC,    3-30  MHz 

BO  Watts  outputp    12  dB   gain  $17.95  each 


EIHAC   FINGER  STOCK     #¥-302 

36   in.    long  x  i   In.        $4,99  each 


m  ORDERS   UNDER  $10 


212     73  Magazine  •  December,  1980 


MRF203 

MRF216 

MRF2ZI 

HRF226 

MRF227 

MRF238 

MRFZ'tO 

rtRF2'*5 

MRF247 

MRF262 

HRF3 1 k 

MRFit06 

MRF'tl2 

MRFJ^21 

MRF422A 

MRF422 

MRFitZS 

HRF'+28A 

MRF^+ZS 

HKFk26A 

MRFlfi+9 

MRFl^itgA 

MRF^tSO 

MRF450A 

MRF'*52 

«RFi*53 

MRF'tS't 
MRFi+S'^A 

MRF^55 

MRFi*55A 

MRFlt72 

MRF*^7'+ 
MRF'+75 
MRFU76 

MRFU77 
MRF485 
MRFi+92 
MRF502 
MRFfiOif 

HRF629 
MRF648 

MRF901 
MRF902 
MRF90tf 

HRF9H 
MRF5I76 

MRFSOO^ 

BFR90 

BFR9I 

BFR96 


2822  North  32nd  Street,  #1    •    Phoenix,  Arizona  85008   •    Phone  602-956-9423  ^^^ 


$P.O.R. 
19.^7 

8.73 
10.20 

2.13 
10,00 

14,62 
28.87 
28,87 
6.25 
12.20 

11-33 
20.65 

27.45 
38.25 
38.25 
38.25 
38.25 
8.87 
8.87 
10.61 
10.61 
11.00 

n.77 

15.00 

13.72 

21.83 

21.83 

14.08 

14.06 

2.50 

3.00 

2,90 

2.25 

10.00 

3.00 

20.40 

*93 
2.00 

3.00 

26.87 

3.99 

9.41 
3.00 

4.29 
11.73 

1.39 
1.00 

1.25 
1.50 


BFW92A 

BFW92 

MMCM913 

MHCM2222 

MMCM2369 
MMCM2484 
MMCM396OA 
MWAllO 
MWA 1 20 
MWA 1 30 
MWA210 
MWA 2 20 
MWA230 
MWA3 1 0 
MWA 3 20 
MWA330 


$ 


KOO 

.79 
14.30 

15.65 

15.00 

15.25 

24.30 

6.92 
7.38 
8.08 
7.46 
8.08 

8.62 
8.08 
8,62 
9.23 


TUBES 

6KD6 

$     5 .  00 

6LQ6/6je6 

6.00 

6mj6/6L(16/6JE6c 

6.00 

6lf6/6mh6 

5.00 

1 26Y7A 

4.00 

2E26 

4.69 

4X1 5OA 

29.99 

4CX250B 

45.00 

4CX250R 

69.00 

4CX300A 

109.99 

4CX350A/3321 

100.00 

4CX350F/J/8904 

100.00 

4CX1500B/8660 

300.00 

SUA 

20.00 

6360 

4.69 

6939 

7.99 

6146 

5.00 

6  146a 

5.69 

61468/3298 

7.95 

6146W 

12.00 

6550A 

8.00 

8908 

9.00 

8950 

9.00 

4-400A 

71.00 

4-400C 

80.00 

572B/T160L 

44.00 

7289 

9.95 

3-ioooz 

229.00 

3-5OOZ 

129.99 

TO-3  TRANSISTOR  SOCKETS 
Phenol ic   type        6/$l .00 


yHF/VHF    RF    POWER  TRANSISTORS 

CD2867/2N6i+39 
60  Watts  output 

Reg^    Price      $^5^77 

SALE  PRICE   $19-99 

1900  MHz  to  2500  MHz  DOWMCONVERTERS 
Intended  for  amateur  radio  use 
Tunable  from  channel  2  thru  6 
3^  dB  gain   2*5  -  3  dB  noise 
Warranty  for  6  rrranths 
Model  HMR  II  with  dish  antenna 
Complete  Receiver  and  Power  Supply 
$225-00  (does  not  include  coax) 
k   foot  Yagi  antenna  only 

539-99 

Downconverter  Kit  *  PCB  and  parts 

$69,95 

Power  Supply  Kit  -  Box,  PCB  and  parts 

$49*99 

Downconverter  assembled 

$79-99 

Power  Supply  assembled 

$59*99 

Complete  Kit  wrth  Yagi  antenna 

$109.99 
REPLACEMENT  PARTS 

MRF901  $  3*99 
MBDIOI  1.29 
,001  Chip  Caps  t .00 
Power  supply  PCB  4-99 
Downconverter  PCB  19-99 

NEW  ASCII  ENCODED  KEYBOARDS 

110  Keys  Numeric  and  Cursor  Pad 

Ho  data  available   $19^99 __^ 


86  PIN  MOTOROLA  BUS  EDGE  CONNECTORS 
Gold  plated  contacts 
Dual  U3/86  pin    .156  spacing 
Solder  tail  for  PCB    $3-00  each 

CONTINUOUS  TONE  BUZZERS 

12  VDC      $2>00  each 

no  VAC  MUFFIN  FANS 

New  $11,95     Used  $5.95 


PL-259  TERMINATION 
$1 .50  each 


52  Ohm  5  Watts 


NO  ORDERS  UNDER  $10 


t^  Reader  Service— see  page  226 


73  Magazine  *   December,  1980     213 


ramss^    the  first  name  in  Counters  ! 


9  DIGITS  600  MHz  $129 


SPECIFICATIONS: 


WIRED 


FSICES 

irT  KfwirBit  1  yewwvnnL-y 

5125  iJJ 

CT  W  K  It  90  di>  |unE  ^^'ir 

'^"^Y. 

IW^S 

AC  t  AC  idipl«r 

i.93 

BP  h  Nkidpick   '^AC 

Adupur.Thfl.rptr 

tJU 

OV  1 .  hficT'O-pTM^r  0>tJi 

Ijpue  tiiu 

49  9f 

Fil*nv*l  timt  Nse  WipiH 

l*.«S^ 

The  CT-SO  >s  the  most  versaiilt  feature  packed  counter  available  f&r  less 
tltanSi^OO.OOf  Advanced  design  features  injclude^  Ihree  selectable  gatetamei^ 
nine  digits,  gate  indicator  and  a  unique  disptay  hnid  function  whit^h  hotdii  ihne 
displayed  count  after  the  inpur  signal  is  fetdDved!  Alsa  a  J  OmHz  TCXO  time 
base  is  used  which  enables  easy  zero  beat  calibration  checks  against  WWV. 
Opttonally:  an  inft^mai  nicad  battery  pack:,  external  time  base  input  and  Micro 
power  hi^  stability  crystal  oven  time  base  are  available.  The  CT-90, 
perfonnance  you  can  count  on! 


Ran.ge: 
Sensttivityt 

ResolutiocE 


Display: 
Time  btse: 

Power: 


20  Hz  ID  600  MHz 

Uss  thflft  10  MV  to  150  MHz 

Less  than  50  MV  to  500  MHz 

0.1  Hz  (10  MHz  ranRe) 

LO  Hz  (60  MHz  range) 

10.0  Hii{600  MHz  range) 

9  digits  0.4  ■  LED 

Standard- lO.tXMJ  mHi,  10  ppiti  lOAO^C. 

Optioflfl]  Micro- power  ovflivO.l  ppm  20-40"' C 

a  15  VAC®  350  ma 


7  DIGITS  525  MHz  $99 


WIRED 


SPEClFtCATIONS; 


Range: 
Sensitivity: 

Resolution: 


Display: 
Time  hasec 
Power: 


20  Hz  to  525  MHf 

Less  than  50  MV  to  1  50  MHz 

Uss  than  1  50  MV  to  SOO  MHi 

1.0  Hz  {5  MHa  ran&e) 

10,0  Hi  (50  MHz  rAitgeJ 

100.0  Hz(50O  MHz  range) 

7  digits  0,4'  LED 

1,0  ppniTCXO20  40X 

12  VACJ^  250  ma 


The  CT-70  breaks  the  price  barrier  on  lab  quality  frequency  counters. 
Deluxe  feat  lines  such  a^  three  frequency  ranges-  each  with  pre  annpEifi  cation, 
dual  selectable  gate  times,  and  gate  activity  indication  make  measurefnents  a 
snap.  The  wide  frequency  range  etiabies  you  to  accLiralely  measure  signals 
from  audio tkni  UHF  with  1 .0  ppm  accuracy-  thaf  s  .0001%!  The  CT-70  is 
the  adsw'er  to  all  your  measurement  needSi,  in  the  Held,  lab  ar  ham  shack. 


PRICES: 

CT-70  wired,  1  year  warranty 
CT-70  Kit,  *0  day  parts  war- 
ranty 

AC-1  AC  adapter 
BP-1  Nicad  pack  +  AC 
adapter/ charger 


S99M 


7  DIGITS  500  MHz  $79 


PRICES: 


MINHOO   wired,    1    year 

warranty 

S79.95 

MINI- 100  Kit,  90  day  part 

warramy 

59,95 

AC  Z  Ac  adapter  for  MINI- 

100 

3.95 

BP-Z  Nicad  pack  and  AC 

adapter/ charter 

12,95 

Hene's  a  handy,  general  purpose  counter  that  provides  most  counter 
funclions  at  an  Udbehevable  price.  The  MINI- 100  doesn't  have  the  fulE 
frequency  range  or  input  impedance  qualities  found  in  higher  price  Linits<  but 
for  basic  ItF  signal  me^$uremciits^  it  can't  be  beal^  Accurate  measurements 
can  be  made  from  1  MHz  all  the  way  tip  to 5 00  MHz  with  excellent  sensitivity 
throughout  the  range,  and  the  two  gate  dmc^  let  you  select  the  resolutioii 
desired  Add  the  nicad  pack  option  and  the  MINI- 100  makes  an  ideal  addition 
to  your  tool  box  for  "in- the- field"  frequency  checks  and  repairs. 


WIRED 


SPEClFTCATJONSb 


Range; 

Sensitivity: 

Resolution: 

Display, 
Time  base: 
Power 


I  MHz  !o  500  MHz 
Less  than  35  MV 
100  Hz  {slow  gate) 
L  0  KH2  (fast  gate) 
7  digits,  0.4"  LED 
2.0  ppm  20^40°  C 
5  VDC  (ft  200  ma 


8  DIGITS  600  MHz  $159 


WIRED 


SPECiPtqATIQNS: 


Range 
Scnsilivitj^ 

Kesolutioni 

Display: 
Time  base] 
Power 


20  Hz  to  600  MHz  The  CT-50  is  a  versatile  lab  bench  counter  that  will  measure  up  to600  MMz 

L^ss  than  25  mv  to  I  50  MHz    withS  digit  precision.  And,  one  ofitsbejit  features  is  the  Receive  Frejquency 

Adapter,  which  turns  the  CT-50  into  a  digital  readout  for  any  receiver.  The 
adapter  is  easily  pfogrammcd  for  any  receiver  and  a  simple  connection  to  the 
receivef  s  VFO  is  all  that  is  required  for  use.  Adding  the  receiver  adapter  in  no 
way  limits  the  operation  of  the  CT-51}.  the  adapter  can  be  conveniently 
switched  on  or  off,  The  CT-50,  m  counter  that  can  work  double^  duty? 


Less  than  150  mv  to  600  MHz 
1 .0  Hz  (60  MHz  range) 
LO.O  Hz  (600  MHz  range) 
8  digits  0.4"  LED 
2,0  ppm  20-40'C 
110  VAC  or  12  VDC 


FRICESc 


CT-50  wired,  I  year  warranty 

CT-50  Kit,  90  day  parti 

warranty 

RA-I.  receivef  adapter  kit 

RA-1  wired  and  pre^progjam- 

med  ( send  copy  of  receiver 

schematic) 


115995 

J 1 9.95 
14  95 


DIGITAL  MULTIMETER  $99^ 


WIRED 


PRICES; 

DM-700  wired,  I  year  warranty 

DM  7t)0  Kit,  90  day  parts 

warranty 

AC- 1,  AC  adaptor 

HP  :?,  NIcad  pack  +AC 

adapter/ chargjer 

MP- 1,  Probe  kit 


$99.95 

79.95 

3.95 

19.95 
2.95: 


The  DM '700  offers  prafessiona]  ctunhty  perfoririance  at  s  hoW>viST  ptic*. 
Features  include;  26  different  ranges  and  5  functions,  all  arranged  in  It 
cotivenien tt  easy  to  us-e  format  Measurements  are  displayed  on  a  targ^e  JM 
digit,  ^  inch  LED  re^d^UI  with  autoniatic  decimal  ptaccmeot,  automatic 
polarity,  overrange  indication  landov^ load  pfoieaion  up  to  1 250  voir* on  All 
rfinges.  rrb&ltirtg  it  virtually  got^f-ptortfl  Tht  DM-700  l(>£ik.«i  grr!?t,  a  hrahdAOmei 
)et  black,  ruf^ed  ABS  case  witii  convitnient  retractabte  cih  h^i|  rnAk^  it  »ri 
ideal  addition  to  any  shop. 


SPECIFICATIONS: 

DOACvoiii: 

lOOuV  tol  KV.  5  rangeis 

DO  AC 

current 

0.1  uA  to  2.0  Amp^  5  ranges 

Resistance; 

0, 1  ohms  to  20  Megohms,  6  ranges 

Input 

Impcdancer 

10  Megolims,  DC/ AC  volts 

Accuracy. 

10.1%  basic  DC  volts 

Power 

4  "C  cells 

AUDIO  SCALER 


For  high  resolution  audio  measuremetits,  multipiies 
UP  in    frequency, 

•  Great  for  PL  tones 

■    Multiplies  by  tO  or  LOO 

*  0.01  Hi  resolution! 

529.95  Kit      S39  95  Wired 


ACCESSORIES 

Telescopic  whip  antenna-  BNC  plug. S  7.95 

High  impedance  probe^  light  loading , , . ,  , .  15,95 

Low  pass  probe,  for  audio  measurements , , 1 5  95 

Direct  probe,  general  purpose  usage 12.95 

Tih  bail  for  CT  70.  90.  MINl-IOO 3.95 

Color  burst  calibration  unit,  eaJtbratcs  counter 

against  color  TV  signal,  .  .  ^ 14.95 


COUNTER  PREAMP 


For  meEisu ring  extremely  weak  fiignals  from  LO  to  L^OOO 

M  H ; .    Sma  11  size,  powered  by  pi  u  u  tr  a  nsf ormer-i ncluded. 

•  Flat  25  db  gam 

•  BNC  Connectors 

•  Great  for  sniffing  RF  with  pick-up  loop 

S34,95  Kit     S44.95  Wired 


ramsey  electrDnic's,  inc.  ^^t 

2575  Baird  Rd.  Penfield,  NY  14526 


["^iTP 


^&2 


PHONE  ORDERS 
CALL  716-586-3950 


letyrn     in    ^ri^irtol    fonVi    F^r     r^+uod      Add    ^•'■"     for    ihipping 

■nturan^a  ro  D  maMiTiLini  qI  t  >C    Ov«rieai  odd  I  5~''<,    COO  odd 

f}    Ordtft  tind-*!' $  I  0     add  S  I    bO    N  T  r*iid»rifv  add  ?'>    tax 


214     73  Magazine  *  Decembef,  1980 


n 


INTRODUCING  SONY'S  NEW 
DIGITAL  DIRECT  ACCESS  RECEIVER! 


A  Whole  New  Breed  Of  Radio 

Innovative  design  Advanced  lechnology.  Digital  key-touch 
tuning.  The  ICF-200V  It's  a  whole  new  breed  of  radio.  A 
receiver  that  supplants  the  conventional  mufti-band  concept, 
receiving  a  wide  amplitude- modulated  frequency  range- 
shortwave,  mediumwave  and  most  longwave  broadcasts.  Plus 
FM.  SSB  and  CW.  Even  more  important,  the  2001  replaces  the 
ordinary  tuning  knob  and  dial  with  a  direct-access  tuning 
keyboard  and  a  Liquid  Crystal  Display  (LCD)  for  digital 
ffequency  readout  Which  make  the  unit  as  easy  to  use  as  a 
pocket  calculator  Instant,  direct-access  tuning  modes  and  six 
memory-station  presets  assure  maximum  ease  of  use.  And  the 
quarJz-crystal,  frequency-synthesized  circuitry  behind  them 
assures  outstanding  reception.  Receplfon  of  local  broadcasts 
and  exciting  news,  music,  sports,  entertamment  and 
information  from  around  the  world.  You  II  get  the  inside,  local 
news  storfes  from  foreign  countnes     exclusfve  coverage  of 
world  sports  events  ,.  plus  everything  from  informal  "ham "  to 
marine  communicatfons  All  at  your  fingertips. 

Key-Touch  Tijntng 

To  tune  a  station  manually  you  simply  punch  in  the  station 
frequency  numerals  on  the  direct-access,  digital  tuning 
keyboard.  Press  the  "Execute"  key  and  the  command  «s 
entered,  the  station  is  received  and  LCD  readout  confirms 
tuning.  If  you  punch  in  an  incorrect  frequency  by  mistake,  the 
ICF-20O1  tells  you  to  "Try  Again"  by  flashing  those  words 
on  the  display  The  instant,  fingerttp  tuning  provides  total 
accuracy  and  convenience  And  the  LCD  digital  frequency 
display  confirms  the  exact,  drrft-free  signal  reception. 

Automatic  Scanning 

In  auto-scan  mode,  the  tuner  can  be  set  for  continuous 
scanning  of  a  given  frequency  range,  which  you  set  by  means 
of  upper  and  lower  limit  keys  designated  "L,"  and  "L."  You 
may  want  to  scan  an  entire  frequency  range.  For  instance,  the 
76  to  108  MHz  FM  spectrum.  If  you  want  scanning  to  stop  at 
any  strong  signal-one  that  reads  "4^'  or  "5"  on  the  LED  signal- 
strength  indicator^  switch  on  "Scan  Auto  Stop."  For  continuous 
scanning,  leave  the  switch  off,  and  just  press  the  "Start/Stop" 
key  to  listen  to  a  station  or  resume  scanning. 

Manual  Tuning 

Like  the  auto-scanning  mode,  manual  tuning  is  useful  for 
quick  signal  searching  when  you  don't  know  particular  station 
frequencies  within  a  given  range  You  simply  press  the  "Up"  or 
'"Down"  key  and  the  tuner  does  the  searching  for  you.  And  if 
you  press  the  Tast "  key  at  the  same  time,  the  scanning  rate 
increases  for  especially  rapid  station  location.  When  you  hear 
a  broadcast  you  want  to  receive,  just  release  the  keys  for 
instant  reception,  presssing  the  "Up"  or  "Down"  key  again  if 
necessary  for  exact  tuning. 

Memory  Presets 

Alter  you  ve  tuned  a  station  us^ng  punch-in,  key-touch  tuning 
or  either  scanning  mode,  you  can  enter  ii  in  the  2001  s 
memory  for  instant,  one-touch  preset  reception.  Which  means 
no  retuning  hard-to-find  foreign  broadcasts  Plus  instant 
access  to  your  favorite  iocal  stations  for  music  and  news,  Six 
preset  buttons  allow  up  to  six  stations-- in  any  wave  range-to 
be  memonzed  And  there's  LCD  digital  readout  of  the  memory 
buttons  being  used  on  each  band  Whats  more,  the  upper 
and  lower  limit  keys  can  be  used  as  memory  presets  when 
they  re  not  betng  used  tor  scanning,  allowing  a  total  of  eight 
frequencies  to  be  memorized  tor  msEanL  one-louch  reception. 


Frequency  Synthesis 

The  200VS  direct-access  tuning  and  outstanding  reception 
quality  are  made  possible  by  the  unit's  ait-band  quartz  ^crystal 
PLL  ffequency  synthesis.  Instead  of  the  conventional  analog 
tuning  system,  with  its  variable  tuning  capacitor  the  2001 
incorporates  an  LSI  and  a  quartz-crystal  reference  oscillator. 
Which  means  that  the  local-osctllalor  frequencies  used  in 
superhetefodyntng  are  locked  to  the  "synthesized"  quartz 
reference  frequencies  The  result  is  the  utmost  in  tuning 
stabrlity  without  a  trace  of  tuning  drift.  In  addition,  dual- 
conversion  superheterodyning  for  AM  assures  exceptionally 
clean,  clear  reception  across  the  entire  150-t0'29, 999k Hz 
spectrum 

Features 

FM/AfVl/SSB/GW/wEde  spectrum  coverage 

Duai-conversion  superheterodyne  circuitry  of  AM  assures 

high  sensitivity  and  interference  reiection 

Quartz^rystal,  phase-locked-loop  frequency  synthesis  for  all 
bands  assures  the  utmost  tuning  stability,  without  a  trace  of 
tuning  drift 

Direct-access,  digital  tuning  keyboard  and  LCD  digital 
frequency  readout  for  quick,  key-touch  station 
selection-maximum  accuracy  and  ease  of  use 

Manual  tuning  and  automatic  scanning  tor  effortless  signal 
searching,  easy  DXing 

6-station  presets,  plus  2  auxiliary  presets,  for  instant 
reception  of  memonzed  stations  on  any  band -plus  LCD 
memory  indication. 

5-siep  LED  signal-strength  indicator 

Local/Normal/DX  sensitivity  selector  for  AM 

SSB/CW  compensator  for  low-distortion  reception 

Telescopic  antenna,  plus  external  antenna  included 

A**  speaker  tor  toll,  rich  sound 

Sfide*bar  bass  and  frebJe  controls 

Sleep  timer- with  LCD  readout- can  be  set  m  lO-mmute 
increments  for  up  to  90  minutes  of  play  before  automatic 
radio  shut -off 


Only 


$299 


95 


Ptus  $S,00  S&H       (Conn  U.S,A.  Only} 


1^67 


PHONE:  (312)  848-6777 


• 


INC.  —  1009  GARFIELD  ST.. 
OAK  PARK.  ILL.-60304 


AZDEN  •     NEW!     •  AZDEN     • 


EWI     *  AZDEN    -k     NEWI     *  AZDEN 


THE  GIANT 


COMPANY 


REVOLUTIONIZES  THE  STATE  OF  THE  ART 

INTRODUCE  THE  BRILLIANT  NEW  PCS" 2800 


llvl 


AND 


MICROCOMPUTER  CONTROLLED 

SUPERIOR  COMMERCIAL  GRADE 


•IM 


FM  TRANSCEIVER 


FALL 
SALE 


Ft  ♦  ^::  rf  ■:•:•  •  *::*  ;j 


AZDEN 

1''^                              -^^m-                'iH^ 

PeS-2800 

jmmm 

r 

(              f     1      f     f 

1                               M           A             *            M 

>  .^.  « 

^i 

'  •  L'  C 

•  •  •  •  • 

UHt    '■ 

\J%         MA» 

■H^^B^ttfUi&tSii^&nH 

• 

• 

KM 


r  r 


lOOK 


\J-      \J.- 


HGH/XXm      TOL4SQL 

1  A     JK  MV^CT     A. 


WVt^Nf 


Ml 


l&m. 


mastet  cfhangt- 


V7S4- 


•  *.*. 


COMPARE  THESE  FEATURES 
WITH  ANY  UNIT  AT  ANY  PRICE 


FREQUENCY  RANGE:    Receive  and   transmit:   28.000  to  29.995 
MHZp  10KHZ  steps  with  builHn  +  100  KHz  repeater  offset. 
ALL  SOLID  STATE-CMOS  PL  DIGITAL  SYNTHESIZED. 
SIZE:  UNBELIEVABLE!  ONLY  6  3/4"  X  2  3/9"  X  0  3M".C0MPAREr 
MICROCOMPUTER  CONTROLLED:  All  scannlnQ  and  frequency- 
control  functions  are  performed  by  mtcrocomputer. 
DETACHABLE  HEAD ;  IhB  control  head  may  be  separated  from  the 
radio  for  use  in  limtted  spaces  and  for  security  purposes. 
StX-CHANNEL    MEMORY:    Each    memory    is    re-programmable- 
Memory  is  retained  even  when  the  unit  is  turned  off. 
MEMORY  SCAN:  Ihe  six  channels  may  be  scanned  in  either  the 
**busy"  or  "vacant"  modes  for  quick,  easy  location  of  an  occupied 
Of  unoccupied  frequency.  AUTO  RESUME.  COMPARED 
FULL-BAND  SCAN ;  All  ct^annels  may  be  scanned  in  either  "busy" 
or  "vacant"  mode.  This  is  especially  useful  for  locating  repeater 
frequencies  in  an  unfamiliar  area.  AUTO  RESUME.  COMPARED 
INSTANT  MEMOfiY-1   RECALL:    By   pressing   a  button   on   the 
microphone  or  front  panel,  memory  channel  1  may  b©  recalled  for 
immediate  use. 

MiC-CONTROLLED  VOLUME  AND  SQUELCH:  Volume  and 
squelch  can  be  adjusted  from  t^f  micrQpho,ne  for  convenience  in 
mot) lie  operation. 

DIRECT  FREQUENCY  READOUT;  LED  display  s^o^?  operaUng 
frequency,  NOT  channel  number.  COMPARE! 
TEN  (10)  WATTS  OUTPUT:   Also  1   watt  low  power  for  shorter 


distance  communications,  LED  readout  displays  power  selection 
when  transmitting. 

DIGITAL  S/RF  METER:  LEDs  indicate  signal  strength  and  power 
output.  No  more  mechanical  meter  movements  to  fall  apart! 
LARGE  Vs-fNCH  LED  DISPLAY:  Easy-to-read  frequency  display 
minimizes  ''eyes-off-the-road"  time, 

PUSHBUTTON  FREQUENCY  CONTROL  FROM  MIC  OR  FRONT 
PANEL :  Any  frequency  may  be  selected  by  pressing  a  microphone 
or  front-panel  switch. 

SUPERIOR  RECEIVER  SENSITIVITY:  0.28  uV  for  20-dB  quieting. 
The  squelch  sensitivity  is  superb,  requiring  less  than  0.1  uV  to 
open.  The  receiver  audio  circuits  are  designed  and  built  to  exacting 
specif ications^  resulting  in  unsurpassed  received-signal 
intelligibility, 

TRUE  FM,  NOT  PHASE  MODULATION:  Transmitted  audio  quality 
rs  optimized  by  the  same  high  standard  of  design  and  construction 
as  is  found  in  the  receiver.  The  microphone  amplifier  and  com- 
pression circuits  offer  IntetiSgibility  second  to  none, 
OTHER  FEATURES:  Dynamic  Microphone,  built  in  speaker, 
mobile  mounting  bracket,  external  remote  speaker  jack  (head  and 
radio)  and  much,  much  more.  All  cords,  plugs,  fuses,  microphone 
hanger,  etc.  included.  Weights  fbs. 

ACCESSORIES:  tS^  REMOTE  CABLE....  35.00  FMPS-4R  A/C 
POWER  SUPPLY.... $39. 95.  TOUOHTONE  MIC/  KtT....$39.96. 
EXTERNAL  SPEAKER.,., $18.00. 


AMATEUR-WHOLESALE  ELECTRONICS  order  now  toll  free 


8S17  S.W.  129th  Terrace,  Miami.  Florida  33176 
Telephone  {305}  233-3631  •  T^lex:  80-33Be 

Hours;  9-5  hfton.Fri.  j^^  *^^ 

US.  DISTRIBUTOR        ^^^m 
DEALER  INQUmiES  INVITED 


GREDITCARD  HOLDERS  MAY  USE  OUR  TOtr FREE  ORDERING  NUMBER. 


RAMSEY 
ELECTRONICS 
^62  Inc. 


PARTS  WAREHOUSE 


We  now  have  available  a  bunch  of  goodfes  too 
good  to  bypass     Items  are  limited  so  order  today 


2575  Baird  Rd. 
Penfield,  NY  14526 

716-586-3950 


MINI  KrTS  -  YOU  HAVE  SEEN  THESE  BEFORE  NOW 

HERE  ARE  OLD  FAVORITE  AND  NEW  ONES  TOO. 

GREAT  FOR  THAT  AFTERNOON  HOBBY. 


FM 

MINI 

MIKE 


r 


A  Super  hi^h  peftqrmance  FM  w'wr^ 
Jess  mike  hut!  Tfgnsmits  a  stable 
signal  up  to  3W  yards  wJlh  escep- 
tiorraJ  aydto  quaiit/  by  means  of  its 
buill  in  electret  mfke.  Kit  includes 
case,  mike  on-otf  switch,  anten-na. 
baltery  and  sypenn^lruct^ona.  This 
is  fN6  finest  unit  available. 

FM-3  Kit  *14,f5 

FM3  Wired  and  Tested  19,95 


Color  Organ 

See  music  come 
ali^e!  S  different 
lights  flici^er  with 
musrc  One  light 
each  for,  high, 
mid-range  and 
lows  Each  indr- 
vfdualiy  adjust- 
able and  dnves  up 
to  300  W  runs  on 
110  VAC 

Complete  Kit, 
ML-1 

sa.95 


Vlc»ftD  Modulator  Kit 

Con  reel's  any  TV  to  vidso  moniE-or  Super 
SI  able  tunable  o^er  cb.  4-6  Ruos  on  S- 
16V  ac::c&pts  std  vid&os'Q^ai  B«^iur«ncin 
the  mafkfil!    Compiftie  ktl.  VO-i        iT.St 


L«d  Blinhy  K» 

A  great  aEterition  get- 
ler  which  alternately 
Hashes  2  jumbo  LEDs. 
Use  tor  name  badges, 
buttons,  warning 
panel  light*,  anyihing! 
Run$  on  3  10  15  voltS. 
Complete  kit,  BL-1 
S2M 


Sup«r  SlAuth 

Asyper$ensitive  ampM- 
fi^r  which  will  pick  up  9 
pin  drop  at  15  feet!  Greal 
for  monilonng  babys 
room  or  as  general  pur- 
pose amplifier  FuN  2  W 
rms  Output,  runs  on  6  to 
15  voJis  uses  8-45  ohm 
speaker 
Complele  kit,  BM-9 

S5.95 


CPO-1 

Runs  on  3-12Vdc  1  wall  ouL  1  KHZ  nood  for  CPO. 
Alarm,  Audio  OsciMator     Complete  kil  S2.9S 


CaK  Your  Ptione  Order  in  Today 
TERMS:  Saffsfactlon  guaranteed  or  money 
refunded.  C.O.D.  add  $2.00.  Minimum  order 
$6.00.  Orders  under  $10,00  add  $1.50.  Add  6% 
for  postage,  insurance,  handling.  Overseas 
add  15%.  N.Y.  residents  add  7%  tax. 


CLOCK  KITS 

Vour  oJd  favorhet  flr«  here  again.    Ov«r  7.000  Said  to  Date. 
Be  one  of  the  gang  and  Qr4vr  /oum  today! 

Try  your  hand  at  building  the  finest  looking  clock  on  the 
market  Its  satin  finish  anodized  aluminum  case  looks  great 
anywhere,  while  six  .4"  LED  digits  provide  a  highly  readable 
display  This  is  a  complete  kit.  no  extras  needed,  and  it  only 
takes  1-2  hours  to  assembie  Your  choice  of  case  colors: 
silver,  gold,  black  (specify). 

Clock  kit.  12/24  hour.  DCS  $24.95 

Clock  with  10  mrn    ID  timer.  12/24  hour,  DC-10  $29-95 

Alarm  clock,  12  hour  only,  DC-8  $29,95 

12V  DC  car  clock,  DC-7  $29.95 

For  wired  and  tested  clocks  add  $10  00  to  ktt  price. 

SPECIFY  12  OR  24  HOUR  FORMAT 


FM  Wlr«l«»  Mlk«  Kit 

Transmits  up  to  300'  to 
any  FM  broadcast  ra- 
dio, uses  any  type  of 
mike  Buns  on  3  to  9V  Type  FM-2 
has  added  sensittve  mfke  preamp 
stage 

fM-1  kil    $3. as  FM-2  kit     $4.95 


Whisper  Light  Kil 

An  interesting  kit.  small  mike 

picks  up  sounds  and  converts 
them  to  light.  The  louder  the 
sound,  the  brighter  the  light, 
rncludes  mike,  controls  up  to 
300  W.  runs  on  110  VAC. 
•Comptete  kit,  WL-1 
$€.95 


Tone  Decoder 
A  complete  lone  deco- 
der   on    a    smgle    PC 
board     Features     400- 

5000      Hz      adjustable 
range  via  SOturn  pot.  voliage  regu- 
lation  567  IC     Us&fu!  tor  touch- 
tone    burst   detection.    FSK    etc 
Can  also  be  used  as  a  stable  tone 
encoder    Runs  on  5  to  12  volts 
Complete  kit.  TD-i      S5.95 


Car  Clock 

The  UN-KfT.  only  5  solder  connections 


H^f^  5  9  sijp^r  loohii^g.  ru-^i^ti^ -.pri d  accurcile  ^ut^  cIckc:^  which  i^  a  snap  'o  build  and 
insi^ll  Clock  mo^f^mE^n!  is  complfli^iy  assenrbisd  —  you  only  solder  3  *ire5,  antj .? 
switches  tafces  abouT  15  minute^i  DispJay  is  brtgni  tjraen  w\in  automate  bfignjness 
cofilfoi  phctocell  —  assuFeS  you  ol  a  tit^hiy  rpad!ab<e  display  (ijy  or  m^ght  Comes  m  a 
salm  finish  anadifed  aSunnnym  Cflse  whiith  cgn  beairath^cj  5  rdiflerient  ways  usmgJsided 
Tape    Choice  of  sM^/er.  blscii  or  gold  cese  fspecify) 


DC-a  hit   ^2  hCJur  lormal 
OC'3  wrced  and  lasted 


Onivertal  Timer  Kit 

Provides  the  basic   parts  ar)d   PC 

board  required  lo  provide  a  source 
of  precision  Eimimg  and  pulse 
generation  Uses  555  timer  fC  and 
ir>ciudes  a  range  of  parts  (or  most 
tjming  n&eds 

UT-5  Kil  S5.9S 


Mad  Blaster  Kit 

Produces  LOUD  ear  Shattering  and 
adention  igetting  siren  like  sound 
Can     Bupply    up    to    15    waEI;^    of 
obnoxious  audio.  Runs  On  fi-l^  VDC 

f^4B-1  Kil  S4,t5 


Siren  Kit 
Produces  upward  and  downward 
wail  characteristic  of  a  police 
siren.  5  W  peak  audio  output,  runs 
on  3-15  voits.  uses  3-45  ohm 
speaker. 
Complete  kit.  SlVI-3  S2.95 


CalendJir  Alarm  Clock 

The  clock  Thai's  got  it  air  6-.5"  LEDs. 
12/24  hour,  snpoze.  24  hour  alarm.  A 
year  calendar  bahery  backup  an^ 
lots  more  The  Super  TOOl  Chip  \& 
used  Size  5j<4?<2  inches  Complete 
h\l  less  case  (not  available^ 
OC-9  534,35 


Under  Dath  Car  Clock 

Ai<7^  f^Oiit  JC.\Qck  m  a  tifrdLi'rirui  p^a^ricca&pre^lurei 
Q  jumhQ  A£C]  U^DS-  riigri  accuracy  iDDl*^!  eas^ 
3  Wife  ftaaUiip    d^sfiiay  blanks  wi[h  ^gi^ilion.  an-d 

Sup^f  I  nsJifijcl  ions.  OpIiU^al  d^immm- flt(jCiJT7pl4c:Jli'y 
3-d|US(5  ^►Splav  ro  ambiErur  5ig.hl  \VVB\ 

DC  It  csoch  («il^  mrq   br^dtei  tir&Skfl 

DM  1  diFTitnPT  *d*pr<'i  II.M 


so  Hit  TI  m«  Bas* 

miri-iTiOOllfi  ftCflllfUCy  TB?  Kn  IS.iD 

TB-7  Assjf.  59.95 


PARTS  PARADE 


Video  Termir^al 

A  tumpllil-^ry  fuli-nOrtlflinird  SlSndfllone  !■  Mpy  r^r'rm;)U;iirrl  R4njUirw3'On1v  tfrt  A^CH  l<i?vt?CiifFll4n<J  TV 
St?  la  Decomt  a  compieff?  rerm ina*  itn\ I  F ^a^jf es  are  ^i nqta  *tV  su ppJy  J'T  A L  conl^oi led  sync  a"0 eaut! 
r^ires  Urt  geOOl  CfinlpU^ie  CCmticJie-r  arm  kPyhOflrrt<:i:>nrralO'l  5':in4fii  Paul y  Sri'iJ*  OOnrnjl  art t?  rfi^rN^'V 
ALxepIs  and  g-enefaies  ^er-Jfli  ASCII  plLkaparalrEi  t^yPoam  inpul  The'6flT6  i&C<  char  bv  Tonnes  wern 
siifoJluiq  u^pi-.i  afirf  lower  i.sis  rijpJiortaK'  ^ithJ  H*s  F*S?3?  arirl.JOrr'm  Uiof-  iriipr';*^*'^  iir^  hivAt-d  Wriiv 
inducJi.'  'sorkefs  and  crsmpisJe  documpnlatrpn 

Rt  SW1&.  i«fmifial  card  *  IT  (flefff  SeofW  ItiT  wrr»g  uflni  ilBS  95 

Lowpi' Cast  op'rinn  t13  96 

^otvei  fi.Lipply  $14  9S 

nf  WOctL.laJrjT  ml  t7  9S 


IC  SPECIALS 


UNEAR 


3ai 

3BQ 

3900 


^ 


$1.S0 

$1.Q0 

it.  00 
it  00 

tt.2S 

I  ^0 
S  50 

12. as 
$2.95 


TTL 


74S00 

S  .40 

7447 

».6S 

7475 

S  .&0 

7490 

%  .50 

74196 

SI  35 

SPECIAL 


4Dn 

4013 
4D4E 

4059 
45  IT 
451S 
5639 


CMOS 


^flP 


..50 
50 

$im 

50 
59^00 
$2.00 
$1.35 
S1.75 


READOUTS 

FND  .355  r  CC  tl.OO 

FhiD  507^610   5'C  A  1.0D 

hi  AN  72  f  HPT  T3Q    33"C  A       1.-(J0 

HP  rear  43"c.a  a.« 


11C90 
icni6 

72-09 

7  207  A 

7?ieD 

7107C 

5314 

537SAB/G^ 

7001 


$15.00 
$  1.25 
$17.50 
S  5,50 
$21,00 
S12.50 
$  2.95 
S  2,95 
$  6.50 


Assurlmeru  of  Popular  vafues  -  '^ 
watt.  Cut  lead  for  F^C  mounting.  '4" 
centir,  'A"  laads.  bag  oC  300  or 
more 

$1,&a 


Switches 
MinF  toggle  SPOT  *1 .00 

Retf  Pushhultons  NO        3/^1 .00 


Earphones 

speakers  alarm  cEocki  elc 
5  for  $1.00 


Mini  6  onm  &p«8l<:«T 

ApfhKOx  :?'-i"  diam   Round 
lyjse  (Or  radios   rrnke-CtC 

3  iDT  (Z.OfI 


Crystals 

3  579545    MHZ  $1.50 

10.00000    MHZ  S5.00 

5  248600    MHZ  t5,00 


AC  AdAfMar« 

Good  lor  ciocks.  mead 
criargers,all  1  lO  VAC  plug 
one-  and 

a6vdc<&20mA  %^.m 

ia  vac  C*^  iBOmA  $2.50 

12.  vac  &  25am A  |3.(HJ 


^olid  SEflte  Buzjert 

small  nuf^er  4M>  H?  65  dB  gcJwnd 
Wtpvl  tjn  a-12  ii^di;  3i  lO-M  rpA  TTL 
Compalibl*  $1-50 


FERRITE  BEADS 

1»/tt.M 
S/lT.QO 


Wirn  inlo  an-d  apecs 
6  l-i[}lf  Balun  Beads 


TRANSISTORS 


2N39Q4  NPN  0*F 

15/IT.QO 

?N3«fi  PNP  C*F 

ia/fi.M 

ZN4403  PNP  C*f 

IS^tLDD 

JN-UlOHPNC'F 

13/t1.« 

jN«l$FeTC*F 

4y|lOQ 

2lM§40i  PNP  C-f 

5/ti.oa 

^MWWC*F 

4/f1.<Kl 

2Na7n  NPNSiNcon 

tl.H 

2N51T9  UWF  NPN 

if$2M 

Po«4r  Tab  NPN  4i3W 

Jl/t1« 

Powwr  Tift  PMP  40W 

i/in 

MPF  ia?.''2H54S4 

*.M 

NPN  3804  T^p*.  T^n 

50/13.30 

F*(P  3W6  Typ*  T*R 

90it3m 

aN3M5 

%M 

3N3«4«  LUT 

3/1300 

Socliets 

8  Pin  10/$2.00 

14  Pin  10/S2.00 

16  Pin  10/12.00 

24  Pin  4/12.00 

28  Pin  4/$2.CM) 

40  pin  3/ $2.00 


Dtod«« 

S  1  V  Zener  20/$1.0O 
lN9l4Type  50/ $1.00 
lKV2Amp  e/t1-00 

lOOVlAfnp     1S/$1.00 


$lug  Tuned  CoiJs 

SmaH  3''1G"   Hex  Slugs  turned  coil 
3  tums  10  for  $1.00 


AC  OtiX\€t 

PianeJ  MounT  with  Leads 
4/(1.00 


Audio 
Prescai«r 

Make  hfgh  resolution  audio 
measurnnent&.  great  tor  rriiiS-Jcai 
rnstrumeni  tuning..  PL  tones,  etc. 
MultipliesaucfioUPinfrequeiicy. 
selectable  xiO  or  x.100,  gives  Gi 
HZ  resolutton  wit^i  i  sec  gate 
time'  High  sensitivity  of  25  mv.  ^ 
meg  mput  z  and  built-in  tillering 
gives  great  pefformance.  Runs 
on  9V  battery,  atr  CMOS 
PS-2  kit  $?9.95 

PS-2  wired  t3a,95 


600  MHz 
PRESCALER 


»*  M.H'.W     II      III 


5* 


Extend  the  range  of  yojf 
counter  to  600  MHz  Works 
with  all  counters.  Less  than 
150  mv  serisifivjty.  specify  - 

10  or  -10Q 


Wired,  tested, 
Kit,  PS-1B 


PS- IB     S59.&5 
$44.95 


CAPACITORS 

TANTALUM 

1.5  uF55V3/$1.00 
l.a  UF  25V3/S1  00 
,22uF25V3/$1.00 


ALUMINUM 

f  i^C  rrcjry  I  If; 

lOiX!  iiF  l&V  R^jtiJii  (.90 
SDG  uF  20V  AhiaJ  t.SO 
:SQ  uF  i6V  AxiBiS/iLM 
EOyF  ISVRad-^al  10/(1.00 


DISH  CEPAMIC 

{li  r&v  liijh    jQ/it  00 
1  lev  ii/tf.«^ 

HB  pf  M/*1  .M 

0I7  1.&U  20.'S1.» 


DC^DC  Cdnv«rtvr 

S  vdc  input  proil   -9  vdc  @  Mma 
' 9  vdc  proU ucfta   i S vetc  (5)  .35^m ia  fl . 2S 


?5K  20  Tom  Tnm  Pol   *!.(» 
1 K    2Q  Tarn  TriTH  F^l     S  -SO 


Ceramic  IF  Filters 

Mini  ceramic  tutors  7  kHz 

B.W,  456  kHz  $1.50  ea. 


"IE 


Trlflimtr  Cofit 
Sprague  •  i'40  pi 

Stable  Poiypfopyienfl 
.50  H, 


30  Watt  2  tnir  PWR  AMP 

Simpfe  Class  C  power  amp  features  8  tinnes  power  gain  1  W  in 
forSout.  2  Win  for  15  out.  4W  in  for  30  out  Max  output  of  35  W. 
(ncredibfe  valu^i  complete  with  afi  parts,  less  case  and  T-R  relay. 
PA-1.  30  W  pwr  amp  kit  S22.95 

TR-1,  RF  sensed  T-R  relay  kit  6.9S 


MHF-238  iransistof  as  used  in  PA-i 
a-lOdb  gam   l&O  mhz  $11.95 


RF  actuated  relay  senses  RF 

(IW)  and  closes  DPDT  relay 

For  RF  sensed  T-R  reJay 

TR-1  Kit     $6.95 


Power  Supply  KM 

Conapiete     triple     regulated     power 

supply  provides  variable  6  to  i  9  volts  al 
200  ma  and  +5  al  1  Amp.  Excejlenl  load 
rBguiatign.  good  filtering  and  small 
size  Less  transformers  requires6  3V 
Mf  1  A  and  24  VCT 
CompJele  kit.  PS-3LT  $6.95 


Cryitfll  Microphone 

Small  T"  diameter  !a"  thick 
crystal  mike  cartridge    S.7S 


25  AMP 
100V  Bridge 
$1.50  each 

Mini-Bridge  50V 

1  AMP 

2  for  $1.00 


Co«M  Confiector 

Chassis  mount 
BNC  type  $1.00 


Mini  RG-174  Coax 
10  ft.  for  $1.00 


9  VoH  bmiivtf  Ciip» 

Htce^  quad  illy  clips  £  i<tr  St.OQ 

**■  RuCil>er  Gronnin*[«        10  Iqr  t1, 00 


OP^AMP  Special 
Bl-FET  LF 13741  ■  Oireci  pin  (or  pin  741  compatible,  bul  500  000  MEG 
mpul  i.  super  low  50  pa  input  current,  lo*  power  dram 
SO  tor  only        $«.(K>  10  for         %2M 


Pari!  Bbb 

AhU  -0-1  chDkfls  -liitc  C10E..  lanl    retisrors 

lrariS"s1drs.  diodes  MICA  caps  elr 

tm    |>*a  000  fHJI  (1-00  Ifl   fta^  (."WJO  p<i)  t?.iO 


Connacton 

6  pin  lype  gold  cofilacts  tor 
fnA-l0O3  car  cioefc  module 
price  .TS  *«. 


l^tct*    -  your  choice,  please  specrfy 

Mini  Red,  Jumt>o  Red.  High  (rrlenaity  Red,  Jilumff^alor  Red  B/$1 

Mini  Vellow.  Jumbo  Yellow,  Jumbo  Green  fi/i1 


V«rBctDn 
^kitorola  MV  ?W9  30  PF  Nominal  cap  20-60  PF  -  Tuna&ie  range  ■ 

,9«  «Kh  w  a/trw 


78MG 
79MG 
723 
309K 

7805 


«1.2S 

t1.2& 

S.S0 

$1,15 

$1.00 


rai2 

7915 
790S 
7t12 

79t5 


*1-00 
$1  00 

$125 
SI.  2  5 


Shrink  Tubtng  Nub* 

Nic«  precut  pees  of  sficinii  ^i-ze-   1"  x  '•'*" 
shnnl(  to  '■«"   Gf^al  for  splices      SO/flrOC 


Mini  TQ-92  H«pt  Sirrks 

Tnerrria Nov"  Brand  5  to4' f  1,00 

To-220  Heat  Sinks  3  for  $1,00 


Opto  Isolators  -  4N28  type 

Opto  Reflectors  -  Photo  diode  +  LED 


ir^tft 


$.50  69. 

$1.00  ea. 


Wol«  Ptns 

Mctew  aJready  pfBcuT  in  t&ngiii  ol  7  Peri 6ct 
lor  14  pin  sockets    ZQ  atrlpi  for  tl.OO 


CDS  Pbolocallt 

Resistance-  varres  with  ligfrl.  HQ  Ohms  to 

ow^r  3  meg  3  fo<  tT.pO 


1^  n&ader  Service— see  page  226 


73  Magazine  •   December,  1980     217 


TAKE  YOUR  PICK 

these  prices  are  NOT  misprint's ! 

Here  (s  a  chance  to  stock  up  yojr  iabat  unprecendented  prices...  we've  got  to  move  Ihese  Out  to  make  room  for  our  ever- 
expanding  Oofi^Pro"  division.    Umited  quantilias  -  firs!  come,  firat  setv^.    Sorry,  at  these  low  prices  wb  cannot  include  spec 
sheets  or  accept  COD/ telephone  orders.    Part  numbers  must  include  the  special  *S  suffix  or  you  wili  be  Charged  our  regular 
prices.    Parts  rmy  be  house  numt>ered  or  have  dual  markings.  This  is  your  chance  to  save! 


TTL 


7403^ 

Quad  2  inpui  OC 

2lrt2 

7410-5 

Triple  3  mput  NANO 

2irS2 

r4i3^ 

4  to  16  line  decoder/demux 

6/S2 

743S-$ 

Ou^  2  inpul  N AND  DQ 

2irS2 

7444-S 

Gray  lo  decimaJ  decoder 

B/$Z 

J4SQ^ 

And-OT'invofl 

2i;S2 

7472^ 

JK  MS  fNp  tlop 

21f$2 

rms^ 

4  t>it  binary  counter 

lom 

749&S 

5  bit  shifi  refliste* 

12^2 

74122^ 

RelJiggdfabie  0<i9-fitiiK 

16«2 

74151-$ 

B  ctiHml  muK 

Bn2 

r4lS5-S 

Dual  2/4  demux 

3/S2 

741 S9-S 

4  lo  16  line  decodori'demux  OC 

4IS2 

74161-$ 

Synchro  4  bir  binary  counter 

ftISS 

?41§3^ 

Sytichro  4  bit  btnary  coimter 

Bin 

74104^ 

8  bit  shift  leg^er 

fitt2 

74190^$ 

UfMowft  d€C4de  counter 

At%2 

74192-S 

Up/doMm  binarv  counter 

*m 

74134-S 

4  bit  bidirectional  shttt  reg 

4i%2 

74195-S 

4  M  oarallcf  ^\U  reQiSier 

G/S2 

7413«^5 

8  bil  ^ilt  r^kstsr 

4^2 

CMOS 


4012-S 

Dual  4  mput  NAND 

tmz 

402f:KS 

14  stage  counter 

mi 

4023^ 

Triple  3  Inpul  NAND 

12/S2 

4044-S 

Quad  H-S  Latch 

4^^ 

4046^ 

Phase  locked  (oop 

mst 

407 1-S 

Quad  2  inpul  OR 

12;S2 

40^3-S 

Quad  2  in  NAND  SciWiitl  trig 

4;S2 

4M7^ 

Quad  EXCfR 

4f$2 

4510^ 

BCD  up^down  counter 

2;$2 

LINEARS 


tpoickaoa  tyi? 

K  H  ^  TOQtJ.  M  ^  mlnidlp,  0  =  dip,  TK 

=  wmi 

201  H-S 

Improved  301  op  amp 

^0t%2 

aOBH-S 

Micfopowor  op  amp 

m2 

703H-S 

RF/IF  amp 

m%2 

7230-S 

Voltage  regjfator 

6(52 

74tM-S 

Compensated  op  amp 

i5;$2 

145eM-S 

DuGl  741 

10JS2 

4&5eM-S 

OUfll741 

tmt 

4195TK-S 

Dual  track  15V  reg  w/data 

2/S2 

TO-220  NEGATIVE 

VOLTAGE 

REGULATORS 


7906-5 

7»&^S 

7t12S 

73hltl&^ 

7118-5 

7924-$ 


6V  rG^ulator 
€V  regulator 
12V  regutaior 
■1SV  regulator 
■18V  regulator 
'24V  regulator 


2fS2 

2m 

2/S2 
2/S2 
2fS2 

2/12 


OTHER 
SEMICONDUCTORS 


srni 


100^95 
10afS7.a5 
lODTSS.SS 


5i%2 
Af%2JSa 


•  GeneraJ  purpose  silicon  signal  diodes 

•  GT5306  NPf^  darlingion,  min  gain 

17000,  2SV  ^30  mA.  T092  padcsge 

•  NPN  trans^tof  Stmita/  2N3904 

•  PHP  transistor  similar  2N3906 

•  4N28^  optOHCOupier  6  pin  menj<Jtf», 

MCT-2/IL-1  pinout 
■  SN76477'S  cofnpiesi  soufHJ  generator 
"  Op  to- Isolator  Grat)  Ba§  ^  50  mixed  optc- 
tsolalDTs  1rE>m  a  major  man  u  fact  uner  Un- 
marked 6  and  S  lead  minidips  include  slngEe 
and duii  Vfpm  wtlh  diocle,  transistor,  and  darl- 
ington  outputs.  Test  tliem  yourself  and  &ave» 
Mot  recom  mef*ded  for  beginner.  50154 


SAVE! 


SOLDERTAIL 
SOCKET  SPECIAL 

Now  ttiat  you've  got  the  ICs.  get 
some  so€f(et&  at  a  tant^tic  pricel 


14  pin: 
16  pm: 
16  pin: 


S0r$4,95 
50/S4.95 
50JS4.dS 


20  pin: 
24  pin: 
2Spin: 

it)  pin: 


40/S4.95 
aQiS4JS 

30^4J& 
2fWS4.9S 


74LS  TTL 


74LS00 
74LSD1 

74LS*^ 

74LS04 

74LS05 

74LS0e 

74LS10 

74LS1 1 

74LS12 

74LS14 

T4t^l5 

74LS20 

T4LS21 

741522 

74LS26 

74LS27 

74LS30 

74LS32 

74LS33 

74LS37 

74LS3a 

74LS42 

74LS47 

74LS4B 

74LS74 
74LS75 
74LS76 
74LSe6 

74LS109 
74 LSI 23 
74LS125 
74 LSI  26 
74LS132 
74LS136 
74LSl3e 
74LS139 
74LS151 


S0.34 
D.34 
§.34 
0.3S 
0,44 
0.34 
0.34 
0.40 
0.34 
2.20 
QM 
0.34 
0.4D 
0.40 
04S 
0.42 
0,34 
D.46 
0.60 
D.4S 
0.4a 
1.56 

tea 

1.68 
0.54 
0,82 
0.50 
0.58 
0.62 
1,70 
087 
0.87 
1.50 
0.69 
1.87 
1.87 
1.66 


74LS154 

2-10 

74LS155 

t.87 

74LS1S7 

1.57 

74LS160 

2,2a 

74LS161 

aifl 

74LS162 

220 

74LS163 

2J8 

74LSl6d 

375 

74LS169 

375 

F4LS173 

208 

74LS174 

2.05 

74LS175 

1.9S 

74LS1&1 

3.50 

74LS192 

3.05 

74LS195 

1.S? 

74LS221 

\JQ 

74LS2dO 

2.50 

74LS241 

2.50 

74LS244 

2.50 

74LS257 

1,95 

74LS25B 

2.02 

74LSa66 

0,69 

74LS273 

2.91 

74LS283 

2.02 

7413365 

0,88 

74LS366 

0.86 

74LS367 

0.86 

74LS368 

0.88 

74LS386 

0.69 

SOLS05 

o.ae 

80LS96 

0.88 

eOLS97 

0,68 

B0LS98 

0.B6 

B1LS96 

2.10 

61LS96 

2,10 

81LS97 

2,10 

aiLS9B 

2.10 

MORE  TRANSISTORS 
AND  FETS 

2M2221      NPN  TO-IS  unmarked  mtJOO 

2N2222      PNP  Tai8  unmarked  BAIJNI 

2112907 A  PNP  plastic  tvouse  #  5^1.00 

3^3055      NPN  10-2  house  i  1/S0.75 

2N3a04      NPN  tO-105  bouse  U  5fSt.0d 

2N3906     PNP  TaiOS  rvouge  #  5*$1.00 

2144124      30Vr350  mW  TO'92  3(91,00 

2N4304     TD-18  plastic  N-JFET  gen  uum  2/Sl.OO 

2114400     NPN  plastic  house  f  St%tm 

2f#4917      PNPTO-106  5/S1.00 

2W4946      NPN  TO- 106  6f%iM 

2Nsa27      PtJP  10-92  30V  iJSl  OO 

2NS306      NPN  TO  92  daitingtort  3/11.00 

2N5449      NPN  Wtl.OO 

2N54B4      RF  N^FET  W1.00 

D4mi        PNPTO-202  lA  maj{  1WL50 

D44C4       NPN  TO220  4A/55V  1/S0.7S 

D4SC4       PNP  TO'2^  4A/&5V  1«0.7S 

D45He       PNP  Ta220  TOA/eOV  31^00 

MP&3694  NPN  genpUTp  4^100 

FPT100      PhototranSj&tOf  1^^.50 
FtT-2        Dual  N-JFET  TO-18  sim  2H4416    artl.oo 

FET-3        Duai  N-JFET  to  miise  audio  2/S1,D0 

FET-6        Gen  purp  dual  gate  MOSFET  3/S2.0O 
house  # 


16K  DYNAMIC  RAMS 


6A37. 


Ummsi  price  ever  on  e>ne  of  our  most 
popular  items.  Expands  mernory  in  TRS-^' 
-I  and  II.  as  we  I  i  as  rnac  bines  rf^ade  by  Ap- 
ple, Exidv.  Heath  H39,  newer  PETs,  etc* 
Low  power,  speed  (4  MHz).  Add  S3  for  dip 
shufits  plus  TRS-SO"  converBion  instruc- 
tions.  Limited   quantity  —  first  come,   first 

served.,  ^^^^^^^  "^  ^  tranefnam  of  mm  Tandy  Qorp&faifMi 

^pv^    H8  MEMORY 

Qf0^  32K  for  $549 ! 

Limited  quantify;  32 K  ot  static  memoTY  \n 
kit  (not  uoktt)  form.  Includes  all  parts,  sock- 
ets tor  all  ICs,  documentation,  mounting 
bracket,  etc.  With  solder-masked,  double- 
sided,  fully  legended  tsoartj  lor  easy  assem- 
bly. H  you  own  an  Hfl,  this  is  your  chance  to 
obtain  top-notch  memory  —  witfiout  pay- 
ing top-notch  prices. 

MA1003  CLOCK 

MODULE -$14.95 

Our  VBjy  best  clock  module  operates  trom  12V 
DC  and  Inctudes  an  internal  limebaae  accurate  to 
0.01  %p  making  W  ideal  for  mobile  applications  in 
your  car,  van,  or  boat  Blue-green  fjou ascent 
readouts  don't  wash  out  during  the  day,  and  look 
greai  at  night.  Easy  to  build:  just  hook  up  power^ 
add  two  time'Setting  switches,  and  you've  got  one 
Df  the  best  clock  modules  on  the  road  With  ap- 
plicaticin  note  that  shows  you  how  loget  th^i  most 
out  of  your  MA1Q03. 

Also  available:  ctocK/case  combinatior>. 
For  S19.9S,  we'll  include  a  matching  case, 
with  mounting  hardware  and  optical  ftlter, 
along  with  the  MA1003. 

TERMS;  Cai  res  add  tax.  Aitow  5%  for  sniirping-.  eicess 
ratuiHted,  Orders  under  $15  add  Si  tiandfcmg  ViSA*r 
Mastefcarcf*  wdef^  (S25  minlf  call  Ofur  ?4  houf  ordfrr 
desk  at  f<>S>  5^2-^36  COO  OK  *ith  street  address  for 
UPS  PLEA^  HOTE:  TELEPHONE  OAOCRS  AND  COOS 
ARE  NOT  AUOWCD  ON  SPECIALS  LISTED  ABOVE  Sale 
C^ices  good  ihroi^  cower  fnonth  ot  mjtoa£tf)e.  oth«r 
prices  subject  to  change  wtttioul  notice 


GOD  BOUT  ELECTRONfCS 
Sidg  725,  OakUnd  AirporL  CA  94€U 


FREE  FLYEJtThis  ad  isonly  the  fip  ot  Iha  icet>erg; 
our  c  ;  Is) Is  the  res!  af  the  Story    Add  41 

eem&  i  ^larnps  lor  Isi  class  delivery  Oulside 
USA.  mclutte  $2  to  cover  postage  jretundabia 
With  o'der!}  Thsnh  you  fof  foar  bus-iness! 


218     TSMagaitne  •  December,  1980 


Semjconducttx 


•   ^ 


-^  1 


*• 


I, 


u  U   0  0 


Clock  Modufes 


12VIIC 
ALtTOMOTlVEi 

CLOCfC 
*  In  dAid^  •UTOClnckt 

nv  ciociit 

•iaVDCOR«r    Inftru. 

f«nur«:Bright0.3"  flrnifn  cJiffilay.  Inteirml  Rrv^tBUlme- 
havi  .lO-^  ^liC'  /ddv  oecuf .  Au  tu.  d  i&piay  ht  lyh  tiieii  oo  n  ^r  a  I 
to^tq-  Dhsi>iBv  culior  riltDT^bld'  tn  blue,  b I u HiiiirtnS n^  t)r*^&n  Si 
<^Bi\on.  Cof<niy\iHri     [uft  add  iwiTches  sn.cl  1«nt- 


i*. 


MA1Q03IVfodule 


$16.35 


mA  1 0(23  ^7"  torn  Cotl  Diqita  1 1 E  D  C  Hoch  tiK^uU  B  35 

MAItiae  .7"Oi«.L£OAl9mi{:icx^.-Th4ritionMt»  1^-95 

MA5A36  .3"  Low  C«l  tHohal  tED  Ctodt/Turw  6.SS 

MA  1002   S'LED  Di»i*v  Dig  Ckict  &  K^Ofm»f  ^55 


;3  r^ahonal  Semiconductor 

RAM  SALE 


MM5290J-2  (MK4n6/UPD4i&}.  .  ,  $6.95  each 

IGK  DVNA^fllC  RAM  [IBOtVS? 

\U  EACH  S40.-95)    11  CHI  EACH  S56O,0OAi>tl 

MM5298J-3A , S3.25  each 

BK  OVISlAMIC  R,AIVI  (LOW  HALF  DP  1^1^5290^1  200NS 
[a  EACH  S33.BB)    f TOO  EACH  £250.00/1  ot) 

MM21 14-3  .•,,,,, S5J5  each 

*K  STATIC  RAM  tSQQNS) 

1 8  EACH  $43 .9S»    1 1 00  BACH  £450.DO/T4>f  I 

MM21 14L'3 $6*25  each 

AK  ^ATtC  RAM  tLOW  POWER  300*#SI 
(S  EACH  S44,9Sl   nOO  EAC      ?-        .  IOotI 


EPROM  Erasing  Lamp 


-  Ernes  27Q8,  2?1$.  I^OSA.  5203a,  5204Q.  «(c. 

*  Emss  uti  to  4  etupi-wiltiin  20  minutas. 

*  Maintains  oonitint  t«popjirf  distanca  al  an*  inch. 

«  Sp4cul  ci^nductiV*  foirnhnif  «llimma1<t-fllticbutl'd''up. 

*  Built-in  sffty  lock  to  fiffwflnt  UV  Bmpo«ur«,. 

*  Comp^iit  -  only  7  %/W  »  2  7«'  *  2" 

*  Cci^riplAE  with  holdmr^  tr#v  for  4  ctiv*. 

UVSHE    .....,,.  $79.50 


Jumbo  6- Dig  it  Clock  Kit 

•  Four  .e30"hL  BDd  rwo  dOfTht. 

connnon  anod*  d  iV  l«V» 

*  U«c^  MMS314  elocik  dlifi 
«  SMitthmfor  hetirit  mlnutiif  «nd  hold  tLrFi4rt..Qi\i 
«  Hours  aa^tv  ii^i«lAraN«  10  30  lf««t 

•  SJmutJIteEt  wflnut  Cl» 

*  I^&VaC  opflratiOfi 

+  1:2  or  24  hour  opnri^tlon 

«  Includes  d II  compionflnti^  OH  ind  will  irinsformtr 

JE747 $29.95 


6-Di9it  Clock  Kit 


-3-.g*iT  J300  ft    c&m*n, 

•  Hn.  eosiiiv  v>#iA^ila  10  30  fi- 

•  SiFnui*T«l  wflfniii  (JiW 

•  IIS  VAC  otw^*iJO" 

« 12  Of  24  nf.  CiCHfllJOO 

•  Incl.  aU  coffipon*nn,  tut*  Si 
■A fill  tfanE-forrr^tr 


V  C    /    \J    t    t    t t    t    M    1.    M  "^    t  ^Jm  III  w 


Regulated  Power  Supply 

Uses   LM309K-  Heal  link     ^\ —      --. 

provided.    PC   bOAid  cor>-  ^ 

itriJcriQn,  Proviidei  i  30^»d 

1  «mp  @  5  ¥OltL  Can  supply  ij|i 

to    t&V,    -9V   ind    '  12V   Willi 

JE205  Adspitt,  liKludcictKTiHi- 

ncnis^  hardwafe  atxf  ingtmcttorts, 

JE200... S1495 


4il 


f 


■--.  »,j 


ADAPTER  BOARD 
-Adapts  to  JE200- 
±5V,  ±9V  and  1 12V 


DC/DC  conyertGr  with  +5V  input.  Toriodal  hi- 
Sipi^d  switching  XMFR.  Short  circuit  pr pi BCtior). 
PC  b«rd  construclidn,  Piggv^^k  to  JE  300 
board.  Size:  3>4"  «  2  '  jc  9/16"H 


JE205 


i      I     -K      h 


*12.95 


MICROPROCESSOR  COMPONENTS 


MWA^JinA  sumMT  I>E  VtCEI 


■w4  Qrl-«' 

\fO  I  M^jim^'Mt  tilts'' 1*1 

Inicrvjt  Tlinaf 
P*MlBhlr«l  1^  |P*»I] 
dM^  Cantrol 
Interrupt  Qaw\tra\ 
nmpi  PitDt- CRTC4[)lrgl|flP 

o^HP  i^im  jfc-Dii^gJflw*!  oiit<wi* 

&QOfmim  SUPPORT  devices  - 


ICtoa. 


*.m 


D«t«i 


4.» 


444fi  I  'Ss.hIIjE'  Btm.  T*>^i,  fMOIVI 


MlCnCM^nOCESSOH  CHiPS 

ILfNtMM  ADC  CF*U-*-fltt  5lk:r  LCnm.  TBffllV. Qf  1  W| 


ir^utniM* 


Hfu  i-ait  ceMhfij 

CHU-   &|r.C:ti|p|rBrt[Ulb.v1**HAM| 
CPU  Jflft  BVt«  H*M1 
Cl»l>-H«iil^  RAM 


It.K 

II  H 

If-IB 


M» 


>iHIFT  HEGISTtftS 


WUlM 

J5?IV 

IHLPC 


Ai^iDd-tCFH 
AIF13)'LCJ 


111- Pit  DriMmK 

Dmi  |^B>t  Stitlc 
IMlll]H&ert  sialic 

QvBv  »ait  atitic 
-DATA  ACQUISITION  — 

T*\tir'  Tv^  LS^  P»»  Fitll' 
twMfi  f  ■'P*  L*w  P«H  r-Ultf 


4.IH 


I** 


DATA  ACOuiSlTiDN  ICOMTIhulD^' 


OACl 

CD^HH 
AV44I1J 


■  .  -  Pre*. 


tui 


■RAM'S 


3EI1L 

JKU 

II Dl  41103 t 

iita 

ZLUB 

lilt 


JhpI  Kim  I;: 

U^iil  Qvnam-lc 
IHkCi^Kllc 

llffipL  U4i.K 
Sfui  blillc 
JJiM'  iuilc  -UOB 

loat.i  si>Ei«  «»ii 

Wrbf4  »I«IN[  Hftnt  l_ir*  Nwn* 
Mg|i*4  :MalK  l«Ni 

IBir 

I  IF  Ml 


Mi 

J.1« 
1-11 


UHtntHliAUlTl 

jTniii'iipijuHjri' 

lf»j<M»llll> 
ireizi|j»=iwi 

ESIB 


-  pnOMS/EPftOMS — 

l*h  Ei^MOhA  {S4n*l*  ^IV| 

Kvf  HKQM  40{>fln  Callv-Ctdi'li 

vpi  T'i-&i4i£  ai«di>«i'  pnow 


urn 

L4.!fi 

4.« 


■RCM'S- 


■  If 


READ  0#VLr  MiUORlEI- 

IT  A&Ot : 

IMCRlVROCE&£OFi  MANUALS' 


U«: 


1D5JiaCl* 


COIMOiMN 


^£C1AL  FUHCTIOIN 

|jw4'  Ui04  ClENca  D*  I'M-  (kM  »'  I 
iJ-uii  Wti^  ChEl^Cll  tSTlm-aM^I 
■  'b{>p»'  DibC  CDnlFtlJMr 
CiBin[nMnlC4.tlD<;  Chip 
UiCfbB'CiUXWT  n«4l  TdrTit  Ctm^ 

MKrQ60ntrt>ll.flr  ^ll^W-tllqlf  HAW 
Ijiitl  pirKt  LE.DDrlvi 
MlicrvEDnlrDilar  wlt«tB«-DIMI1  AAM 
1  Dtrktl  LED  gTrHV  w^n  Bu«t  int. 


I. 
!*.» 
II.H 

I.B 

IU.» 
tM 

1.4) 

3     JlB 


■TELEPHONE/ICEyaOARD  CHIPS 


mfti^^i^ 


DESIGNERS'  SERIES 
Blank  Desk-Top  Electronic  Enclosures 


HJuH  Etren|th  upDitv  itt^lclbtj 
intf  |ii€cBS  in  inoctl0  lirdwn 
fiiiifh, 

Sildiitg  rear/bDitsm  ^laiiiHc^r 
urvin   irtd   compifnGni  ic 
cuiiibilitv. 

Tflp  /  bottom  pinds.DRO  tH  k 
AlD(fin«  tvpfl  1200 
^ot4    tint   tolar)  for 

hnt    jurat    jbdhnJon    flirr 

modificatkfii. 

Vinttfi  top  iT>d  banofln 
ptntll  fi»r  u«lin|  fMicwocY 

fligid  conAmctiafv  ptoytd^i 
unlttnited  tpplicilimni. 


CONSTRUCTION!    -^         — —  — 

The  "DTE"  Blink  Oesh  Top  Electronic  End  asurei  era  ddtigniidio  biendandcornplfHiiint 

tDday's  rnailurn  compji^r  Bquipmcnl  ar>d  can  be  usud  \n  both  indtistnal  and  home,  TIib 
flnd  pivtQS  flffl  precisiof}  moltlBd  wctb  an  intBrnal  slot  (all  arountl)  to  accipt  liutli  icip  and 
tiQtiom  planets.  The  fjantls  sfu  thm  NstarEd  m  %"  thiicK  tafai  insidE  the  bhiJ  |anju^3stu 
pravittfi  mflRimum  rtgidity  to  \hi  inclosure.  For  eosn  ot  equipmo^nt  servicing,  tbtf  rwf/ 
bottom  pinel  slides  b^ck  on  sJoitad  tracks  wbile  the  ren  of  the  enclosure  rtmiirtt  in- 
ijct.  Di1(«r$nr  p^tiBf  widtl^s  »iiv  bi  visd  wttile  maiivtimiKy  a  commtin  prof  »lt  oytlinc 
The  moldid  end  pf«cn  cin  •!«&  be  piinted  to  match  my  p^nel  tQinr  ichefiie. 


a  _  1 


>: 


Wtdth 

fniCE 

DTE  8 

a  00' 

S29  95 

DTE-II     ' 

10.65" 

S32.95 

DTE'14 

14.00* 

S34.95 

$10,00  Mifi,  Orddf  -  U.S.  FuMi  Only 
Calif.  RuijrJonts  Add  G%  Silil  Ttx 
PaslagiOl  -  A(^d  &%  plus  SI  lnsur«n(!« 


EpHC  Stwrti  -  2&t 

1Sai  ClIflDQ  Avatlabli  —  S«ncl  4  1  ^  itimp 


ameco 


ELECTRONICS 


^33    PHONE 
ORDERS 
WELCOME 
(41S)  592  a097 


1 7/50 


MA  ft  ORDCR  (  UX  IHOMCS  -  hORIDUJDE 

1355  SHOREWAV  ROAD.  BELMOMT.  CA  94002 

PRICES  SUBJECT  TO  CH  AISJGE 


COMPUTER  CUBE^*^ 


COMPUTER  CRT  MaNtian  a  ACCESSOHV  CASE 

•  Ona  P^K*  ri»it¥V  ili^c-r  rnnld«d  connructiaf* 

■  Pninnrd  io  mfttefi  AppreU  JLilfiLt   b«iiQ«.  TBXTtjrect  f  jnh^l 

•  SiT>fika  ■^O'loriti  iii^rvtie  froftt  CE>v*f  [' iTHavaU  !•) 

•  ^111-41   tl4«tf  niMOi  CRT  and   tJIOA-i  iooin  iar  2.  AciOl4 

•  Thi>«*2>l"  n&t«t  ipc^ta^idi^  in  doitiairi  a'<  i^m  fOradd-t  w^- 

•  Dt  f^n  it  naadad. 

•  Fan  tt«|«  ,p9Vfiart*d  Msfwa  Apola  itiOtn^lHMnt  loctx»«n 

•  Haahuj}  carif%i  c*rt  t^t  fufl  ttirqughi  Qtfwr  3  N«>laL 
•Crt*  «^£!{»nvini«KKta«  riwTT  fi&W  pn^  Co*or  i^ncpasd  CnT 

•  moriilon  ctisOr  Bv  »*Ot<wol*.  ft#n   Br«t ,  Z«rnt**.,  Sv^'O. 
~  rioMonlr.  Hywcrii.  vtc,  or  anv  moriJiDr  TtuTnriit  fiT  mta 

•  10-3/B"H  m  1*H   W  *  13^^  O  vaea, 

•  SLe*    tr'  *  15"  *  IS'  OP.  14  VH  »  141*^WMa  13*"LI3. 
*W»>#<T    ■ep'ro«  iTutWfV  12  iO< 

*CnT  iT^atiMOf  Im  ffnd  dk^k.  drlvas  nOl  Iinci4j4«0. 


CUBE-1 


$99.95 


TRS-80 
16K  Conversion  Kit 

Enpiafid  y0ut  4K  TRS^BO  SyilBrn  |a  1€K, 
Kit  eomri  complete  i^itli: 

•  B  MKh  MM5390  2  iiif'IMtet  t16K  DviWRk  ftvAs) 

*  DocuFTMfitaitOn  t&r  cuimiuart 


TRS-16K 


$49.95 


JE610  ASCII 
Encoded  Keyboard  Kit 


Th«  J^fitO  ASCm  KavtKur^  K  »t  i^rr  Cm  intarfacad  rntti 
mosi  itFsv  eOrtWJJtPf  f¥«fim.  Tha  kit  COrtt«  co^npltfrt 
whti  an  Imfct-BTiji  grade  «cvbo*rd  MuTcn  dnerpblv 
tei  *«■**>.  iCt.  iOckata,  E?Ortn*ctO',  »l«ciruni«  can^a- 
ttamti  mnti  •  dOufrttf-iidari  prinlad  wi^inft  bo«rd  Ttia 
fc«ftN»r#  HHrnblV  ivqui««s  *5V  #  TSOrnA  •TtO— 12v 
#>  tQ  «nA  rai  ae^ritiiafL  Faaturai  #D  navs  ^n«r«tv  ttw 
139  cftVIKIV^  uPPW  wid  Hovvw  Ci«t  ASCI  I  pat-  FtiOrt 
tiyffmd  T«»a  tftv-dvtiflc  bcyt  0fC%kl«O  tpf  cusiUHn 
K?i?i:iuti04i«.  ClPf  lBcilrl^iriitK»*r-tMa4nilv  a^lia  chervc 
iCFL  Utl|i£^«  ■  Z376  lAO-pinS  enc^odirr  rrat^onlY  fn«fnorv 
c*iie'.  OuVutt  dinKrtiy  itCTir^vt'b'lt  *h*iih  TTt^'OTk  to' 
MOS  iovt  vrt#yK  £*ty  int^rfoEifiii  ■A^lh  «  l^'-om  dip  or 
Tg  (tin  wdtt  connacfor, 


JE610   ICiie  not  included} 
K62   (Keyboard  only)    . . , 


$79.95 

,  *  ^  .  S34.95 


Desk -Top  Enclositre  for 
JE610  ASCII  Encoded  Keyboard  Kit 

Compact  dflik'^top  sncEoiur*:  Colorcoofdmattd  di' 
ligriMr'st  cum  wirh  l»gNt  tan  iluminum  pantl^i  And  moldm 
and  piaciKiin tnodia broiArn.  Inctydvtmcujntifimhardtirar*. 

DTE-AK  ..,...-,. > S49.95 

SPtCtAL    Ji610/DTE-AK  PUflCMASiO TtMa ETHER 

IVaJue  S129.90) S124.95 


JE600 
Hexadecimal  Encoder  Kit 


FUlt  e  BIT 
LATCHED  OUTPUT 
ia  KEV  KEVBOARP 


Tha  JEGOO  Enegdaf  KavbcMrd  Kix  Drov4da9  iwd  MpBiraftc 
tiaxadwctma*  uifiit  traduced  frE»rTt  t«q4j#ftT4*l  key  «niri*fl 
19  illl^V*  d4r#^t  □■A^i'9i\>«V^iii§  ibt  0  bil  nniCTODrOC»l*0*' 
tif  ft^it  n^rfnorv  CJreijiiK   Trtm  •O^JtitanaT  kavs  ara  pfo- 

^[ffUE  Mwlpji^tlbt*    TN»  b«^Jsrt»  *••  tfltdt*^  WKl  iTiOnrt^-  = 

w>lK  SLED  f«*0«MTiL  AJiEi  inc-ludi*df««  h#w  enirv  STFDrti 
f  «aiui««.    FuM   ■  bi^l   l«T£jtt*d   duipul  f»f  vniCOprDovnc 
L±Ea     T^tmm    vaprdafiiw    kav»   wi|h    op4    Cwirtp  btstab^ 

DPCrilhqr;      D*(K>Wn¥9   CtllEUK   {irDVKl#a    fo^    ^1    t'^   kVfL 

g  LED  f««d0ut«  ia  ii«tfhr  •rntjlcs,  Ehv  i^riansciTfa  with 
ExarKiHFd  lA^pttf  tC  tS'nnac^M.  Onty  <5V&C  reqiuirul 
lo^  Dti«rA1ion 


JE600    (CflSe  not  includid) 

K19  (Keyboard  only)    .. ,, 


.  .  .SU.95 


D^k'Top  Enclosure  for 
JE600  Hexadecimal  Keyboard  Ktt 

Compact  dfrik  lop  e3^^;lolure.  Cotor  cjtd'dfn^lod  de- 
sigriBr's  caii  wvilh  light  t^n  alurrfinuTi  panalf  ind  maided 
end  pinert  m  Tiociia  bcown.  Icicludtt  rt«o<jni»ngi  hanJiNfrfl. 
Siiar  3A  "H  M  Si* 'W  n  i^"0. 

DTE-HK * '  * '  •  m  ^  5.*I4-. jj 

SPfC/At    jEftM'OTE-HK  PURCHASED  TOGETHER 
*ValueSltW.90J  . 


»^  Resder  Ser¥ic^ — see  pape  226 


73  Magazine  •  December,  1980    219 


ASSOCIATED  RADIO 

91  3-381-5900 

801  2  CONSER  BOX  A3^V 
OVERLAND  PARK.  KANSAS  BB204 


CALL  US  WITH  YOUR  REQUIREMENTS 

AMERICA'S  NO.  1  Real  Amateur  Radio  Store 


m 


"ASSOCIATED"  IS  THE  BEST  PLACE  TO  BUY. 
*NOTE:  WE  BUY  EQUIPMENT.  AS  WELL  AS 


SELL  AND  TRADE. 
WE'LL  DO  IT  YOUR  WAY! 


master  charge 

ThE  »t4TtnBAFAl  CARD 


NOTE:  SEND  $1.00  FOR  OUR  CURRENT  CATALOG 
OF  NEW  AND  RECONDITIONED  EQUIPMENT. 

ALSO  WE  PERIODICALLY  PUBLISH  A  LIST  OF  UNSERV- 

ICED  EQUIPMENT  AT  GREAT  SAVINGS.  A  BONANZA 

FOR  THE  EXPERIENCED  OPERATOR.  TO  OBTAIN  THE 

NEXT  UNSERVICED  BARGAIN  LIST,  SEND  A  SELF 

ADDRESSED  STAMPED  ENVELOPE. 


220     73  Magazine  *  December,  1980 


FOR  THE  NOVICE 


NEW,  UPDATED  EDtTtONS  OF  OUR  FAMOUS  NOVICE  CLASS  STUDY  GUIDE  AND 
NOVICE  THEORY  TAPES. 


m  NOVICE  STUDY  GUIDE— SG7357— Here  is  a  completely  new  study  guide  and  reference  book  for  the 
potentiai  ham.  Thfs  is  not  a  question/answer  memorczation  course.  Etectronic  and  radio  fundamentais 
are  presented  and  explained  in  an  easy-to-understand  fashion,  preparing  the  beginner  for  the  Novice  ex- 
am. Includes  the  latest  FCC  amateur  regulations,  as  wefl  as  application  forms.  Easiiy  the  best  path  into 
the  exciting  world  of  ham  radio!  $4.95,* 


!?!ffiM^^?^--^t^^'-^'V^ 


"  ^%: 


State 


* 


•  NOVICE  THEORY  TAPES— CT7300-=  Start  ling  Learning  Breakthrough.  You'll  be  astounded  at  how 
really  simple  the  theory  is  when  you  hear  it  explained  on  these  tapes.  Three  tapes  of  theory  and  one  of 
questions  and  answers  from  the  latest  Novice  exams  give  you  the  edge  you  need  to  breeze  through  your 
exam.  73  is  interested  in  helping  get  more  amateurs,  so  we're  giving  you  the  complete  set  of  our  tapes  for 
the  incredibly  low  price  of  ONLY  $15,95.* 

Scientists  have  proven  that  you  learn  faster  by  listening  than  by  reading  because  you  can  play  a  cassette  tape  over  and  over  in  your  spare 
time— even  while  you'redriving !  You  get  more  and  more  info  each  time  you  hear  it.  You  can't  progress  without  solid  fundamentals.  These 
four  hour-long  tapes  give  you  all  the  basics  you'll  need  to  pass  the  Novice  exam  easily.  You'll  have  an  understanding  of  the  basics  which 
will  be  invaluable  to  you  for  the  rest  of  your  life!  Can  you  afford  to  take  your  Novice  exam  without  first  listening  to  these  tapes?  Set  of 
4— $15.95.* 


SPECIAL  OFFER!   BOTH  NOVICE  CLASS  STUDY  GUIDE  AND 
NOVICE  THEORY  TAPES  $20.00  ORDER  NP7300. 


HANDBOOKS  FOR  THE  HAMSHACK 

ijl  •WORLD  REPEATER  ATLAS— BK7315— Completely  updated,  over  230  pages  of  repeater  listings  are 
fcl£V  *  indexed  by  location  and  frequency.  More  than  50  maps  pinpoint  2000  repeater  locations  throughout  the 
™  USA.  Foreign  listings  include  Europe,  the  Middle  East,  South  American  and  Africa,  $4,95. 

•  THE  PRACTICAL  HANDBOOK  OF  AMATEUR  RADIO  FM  REPEATERS— BK11 85— by  Bill  Pasternak  WA6ITF  (author  of  73  Magazines 
monthly  column  ''  Lookrng  West"}  This  is  the  book  for  the  VHF/UHF  FMer,  compiled  from  material  submitted  by  over  a  hundred  individu- 
als, clubs,  organizations  and  equipment  manufacturers,  A  ''must  have"  for  your  ham  shack  shelf.  $9.95, 

•  WORLD  RADiO  TV  HANDBOOK  1981, 35TH  EDITION— BK1 184— This  book  is  the  bible  of  international  broadcasters,  providing  the  on- 
ly  authoritative  source  of  exact  information  about  broadcasting  and  TV  stations  world  wide.  This  1981  edition  is  completely  revised,  giv- 
ing comprehensive  coverage  of  short,  medium  and  long  wave,  560  pages  of  vital  aspects  of  world  listening.  $16.50, 


3  NEW  BOOKS! 


OTHER  STUDY  GUIDES 


•  ADVANCED  CLASS  LICENSE  STUDY  auiDE-SGlCH81-F!eady  to  upgrade  your 

license?  To  prevent  retaking  the  FCC  theory  exam,  you  need  ttie  73  Advanced  theory 
guide.  SSS,  antenna  theory,  transmitters,  and  electronics  measuring  techniques  are 
covered  in  detail  in  this  easy-to-follow  study  guide.  Special  modes  and  techniques^ 
such  as  RTXy,  are  also  treated.  An  engineering  degree  is  nof  necessary  to  rn aster  the 
Advanced  theory — try  this  book  before  visiting  the  examiner's  office!  S6.&5."  {Pub- 
lished by  TAB  Books  previous  to  recent  ctianges  In  FCC  exam  material.) 


»  EXTRA  CLASS  LICENSE  STUDY  GUIDE^SGl060^  Before  going  for  your  T  x  2  call,  it 
pays  to  be  a  master  of  the  Extra  class  electronics  theory.  This  study  guide  ^s  the  logical 
extension  of  the  73  theory  course.  All  the  theory  neces&ary  to  pass  the  exam  Is  pre- 
sented. Antennas,  transmission  lines,  swrare  discussed,  as  we^i  as  nojse^  propagation, 
and  specialized  communication  techniques.  This  book  is  not  a  classroom  lecture  or 
memorizatJon  guider  but  rather  a  logical  presentation  of  the  material  that  must  he  un- 
derstood before  atlempting  the  Exim  exam.  Save  youfself  a  return  trip  to  the  FCC  and 
try  the  73  mettiod  first!  $5.95  * 


•  UNDERSTANDING  AND  PROGRAMMING  MICROCOMPUTERS— BK7382— A  valuable  addition  to  your  computing  library.  This  two 
part  text  includes  the  best  articles  that  have  appeared  in  73  and  Kilobaud  Microcomputing  magazines  on  the  hardware  and  software 
aspects  of  microcomputing.  Well  known  authors  and  well  structured  text  helps  the  reader  get  involved.  $10.95* 

•  40  COMPUTER  GAMES  FROM  KILOBAUD  MICROCOMPUTING^BK73S1  — Forty  games  in  all  in  nine  different  categories.  Games 
for  large  and  small  systems,  and  even  a  section  on  calculator  games.  Many  versions  of  BASIC  used  and  a  wide  variety  of  systems 
represented.  A  must  for  the  serious  computer  gamesman.  $7.95* 

•  SOME  OF  THE  BEST  FROM  KILOBAUD/MICROCOMPUTING— BK7311— A  collection  of  the  best  articles  that  have  recently  ap^ 
peared  in  Kilobaud/MICROCOMPUTING.  Included  is  material  on  the  TRS-80  and  PET  systems,  CP/M,  the  8080/a085/Z80  chips,  the 
ASR-33  terminal.  Data  base  management,  word  processing,  text  editors  and  file  structures  are  covered  too.  Programming  techniques 
and  hardcore  hardware  construction  projects  for  modems,  high  speed  cassette  interfaces  and  TVTs  are  also  included  in  this  large  for- 
mat, 200  plus  page  edition.  $10.95.* 

«  HO&BY  COMPUTERS  ARE  HERE!— BK7322— If  you  want  to  come  up  to  speed  on  how  computers  work. .  hardware  and  software. ,  .this  is  an  excellent  book.  It  starts  with  fun 
d^mentalsand  explains  the  circuits,  and  ttie  basics  of  prograniming,  along  with  acojpJeofTVT  construction  projects,  ASCii-Baudot,  etc.  This  book  has  the  highest  recommen- 
dations as  a  teaching  aid,  34  05* 

•  THE  NEW  HOBBY  COMPUTERS— BK7340=This  book  taNes  it  from  where  "HOBBY  COMPUTERS  ARE  HERE!"  leaves  off,  with  chapters  on  Large  Scaie  Integration,  how  to 
choose  a  microprocessor  chip,  an  introduction  to  programming,  iow  cost  i/0  for  a  computer,  computer  arithmetic,  checking  memory  boards  .  .  .  and  much,  much  moreJ  Don't 
miss  this  tremendous  value!  Only  $4.95.* 

'Use  the  order  card  in  the  back  of  this  magazine  or  itemize  your  order  on  a  separate  piece  of  paper  and  mail  to:  73  Radio  Bookshop  •  Peterborough  NH  Q3453.  Be  sure  to  in- 
clude check  or  detailed  credit  card  information.  No  C.O.D.  orders  accepted.  "Add  $1.00  handling  charge.  Note:  Prices  subject  to  change  on  books  not  published  by  73 
Magazine.  Questions  reqardlfig  your  order?  Please  write  to  Customer  Service  at  the  above  address.  Please  allow  4-6  weeks  for  delivery. 


FOR  TOLL  FREE  ORDERING  CALL  1-800-258-5473 


7^  TEchNicAl  LibRARy 


•  BEHIND  THE  DIAL— BK7307— By  Bob  Grove.  Get  more  fun  out 
of  shortwave  listening  with  this  interesting  guide  to  receivers, 
antennas,  frequencies  and  interference.  $4.95* 

•  THE  CHALLENGE  OF  160— BK7309— is  the  newest  book  in  the 
73  technical  library,  dedicated  to  160  meter  operating.  Si  Dunn  pro- 
vides ail  necessary  information  to  get  started  on  this  unique  band- 
The  all-important  antenna  and  ground  systems  are  described  in 
detail.  The  introduction  contains  interesting  photos  of  Stew 
Perry's  (the  King  of  160)  shack.  This  reference  is  a  must  for  new 
and  experienced  "Top  Band''  operators.  Price:  $4.95.* 

•  IC  OP-AMP  COOKBOOK  — 8K1028— by  Walter  G,  Jung.  Covers 
not  only  the  basic  theory  of  the  IC  op  amp  in  great  detail,  but  also 
includes  over  250  practical  circuit  applications,  liberally  il- 
lustrated. 592  pages,  5V2   x  8V2,  softbound.  $12.95.* 

•  THE  POWER  SUPPLY  HANDBOOK—  BK7305— Need  a  power  supply  for  a  gadget  you Ve  building?  In  the  POWER  SUPPLY  HAN  D- 
BOOK  there  are  dozens  ready-to-bulid,  plus  detailed  steps  fof  designing  your  own.  There  are  circuits  and  parts  lists  for  all  kinds  of 
supplies,  ranging  from  simple  DC  types  to  highly  stable  regulated  versions,  tf  you  need  a  ci  rcu it  to  convert  a  DC  voltage  to  a  higher  or 
lower  voltage,  turn  DC  into  AC,  or  AC  to  DC— then  this  is  the  book  you  need.  With  more  than  400  pages,  you  should  be  able  to  find  just 
the  circuit  you  need.  Without  a  doubt  one  of  the  best  power  supply  source  books  available,  compiled  by  the  editors  ot  73.  $9.95.* 

•  WEATHER  SATELLITE  HANDBOOK- BK7370— Simple  equip 

ment  and  nnethods  for  getting  good  pictures  from  the  weather 

satellite.  Antennas,  receivers,  monitors,  facsimile  you  can  build, 

tracking,  automatic  control  (you  don't  even  have  to  be  home).  Dr. 

Taggart  WB8DQT.$4.9&.- 

•  THE  NEW  RTTY  HANDBOOK— BK7347— is  a  new  edition  and 
the  only  up-to-date  RTTY  book  available.  The  state  of  the  art  has 
t^een  changing  radically  and  has  made  all  previous  RTTY  books  ob- 
solete. It  has  the  latest  circuits,  great  for  the  newcomer  and  expert 
alike.  $5.95.* 

•  PROPAGATION  WIZARD'S  HANDBOOK— BK7302— by  J.  H. 
Nelson.  When  sunspots  riddled  the  worldwide  communications 
networks  of  the  1940's,  John  Henry  Nelson  looked  to  the  planets 
for  an  answer.  The  result  was  a  theory  of  propagation  forecasting 
based  upon  interplanetary  alignment  that  made  the  author  the 
most  reliable  forecaster  in  America  today.  The  book  provides  an 
enlightened  took  at  communications  past,  present,  and  future,  as 
well  as  teaching  the  art  of  propagation  forecasting.  $6.95.* 


•  SSB  . . ,  THE  MISUNDERSTOOD  MODE— BK7351— by  James  B. 
Wilson.  Single  Sideband  Transmission  . . .  thousands  of  us  use  it 
every  day,  yet  it  remains  one  of  the  feast  understood  facets  of 
amateur  radio.  J.  B.  Wilson  presents  several  methods  of  sideband 
generation,  amply  illustrated  with  charts  and  schematics,  which 
will  enable  the  ambitious  reader  to  construct  his  own  sideband 
generator.  A  must  for  the  technically-serious  ham.  $5.50.* 

•  MASTER  HANDBOOK  OF  HAM  RADIO  CIRCUITS- BK1033- 
This  is  an  encyclopedia  of  amateur  radio  circuits,  gleaned  from 
past  issues  of  73  Magaz/ne and  carefully  selected  according  to  ap- 
plication. You'll  find  many  youVe  never  seen  before,  some  new 
twists  on  the  tried  and  true,  and  several  that  have  been  long  forgot- 
ten but  are  wetl  worth  remembering.  Where  your  interest  ranges 
from  ragchewing  to  EME,  from  CW  to  slow-scan  TV,  from  DX  to 
county  nets,  this  handbook  will  be  a  welcome  addition  to  your 
shack,  $B.95.* 


|:^./: 


*  ■  ■■  ; 

i' .  i  '■ 


^OIR 


^iQtlg 


S 


•  OWNER  REPAIR  OF  RADIO  EQUIPMENT- BK731D- Frank  Glass 

K6RQ  shares  over  40  years  of  operating,  servicing,  and  design  ex- 
perience in  this  book  which  ranges  from  the  elementary  tothe  highly 
technical  written  for  the  top  engineers  in  the  field.  It  is  written  in  nar- 
rative style  on  the  subjects  of  electronic  servicing,  how  components 
work,  and  how  they  are  combined  to  provide  communication  equip- 
ment. This  book  will  help  you  understand  the  concepts  required  to 
service  your  own  station  equipment.  $7.95.* 

•  TOOLS  &  TECHNIQUES  FOR  ELECTRONICS- BK7348- is  an 
easy-to-understand  book  written  for  the  beginning  kit  builder  as 
well  as  the  experienced  hobbyist.  It  has  numerous  pictures  and 
descriptions  of  the  safe  and  correct  ways  to  use  basic  and 
specialized  tools  for  electronic  projects  as  well  as  specialized 
metal  working  tools  and  the  chemical  aids  which  are  used  in  repair 
shops.  $4.95* 

•THE  CONTEST  COOKBOOK- BK73a8-reveals  the  secrets  of 
the  contest  winners  (Domestic^  DX  and  specialty  contests),  com- 
plete with  photos  and  diagrams  of  equipment  used  by  the  top 
scorers.  Find  out  how  to  make  150  contacts  in  one  hour.  $5,95* 

*  Use  the  order  card  in  ilie  back  oMNs  maaaiine  or  ilemize  your  order  on  a  separate  pfcece  of  paper  and  mall  to:  73  Radio  Bookshop  •  Peterboroygh  NH  03458.  Be  sure  to  in- 
clude check  or  detailed  credit  card  infornnatiori.  No  CO.D.  orders  accepted.  *  Add  SlOO  handling  charge.  Note:  Prices  s^ubject  to  change  on  books  not  published  by  73 
Magazine.  Questions  reqafding  your  order?  Please  write  to  Customer  Service  at  the  above  address,  Please  allow  4-6  weeks  fOf  delivery. 


FOR  TOLL  FREE  ORDERING  CALL  1-800-258-5473 


TEST  EQUIPMENT 


•  RF  AND  DIGITAL  TEST  EQUIPMENT  YOU  CAN 
BUILD— BK1044—Rf  burst,  function,  square  wave  generators, 
variable  length  pulse  generators— TOO  kHz  marker,  i-f  and  rf  sweep 
generators,  audio  osc,  af/rf  signal  injector,  146  MHz  synthesizer, 
digital  readouts  for  counters,  several  counters,  prescaler, 
microwave  meter,  etc,  252  pages.  $5.95.* 

•  VOL.  I  COMPONENT  TESTERS— LB7359— ...  how  to  build 
transistor  testers  (8),  diode  testers  (3),  IC  testers  (3).  voltmeters 
and  VTVMs  (9),  ohmmeters  {8  different  kinds),  inductance  (3), 
capacity  (9),  Q  measurement,  crystal  checking  (6),  temperature  (2), 
aural  meters  for  the  blind  (3)  and  all  sorts  of  miscellaneous  data  on 
meters  .  .  .  using  them,  making  them  more  versatile,  making  stan- 
dards. Invaluable  book.  $4.95.* 

•  VOL    II    AUDIO    FREQUENCY   TESTERS— LB7360— ...  jam 
packed  with  all  kinds  of  audio  frequency  test  equipment.  If  you're 

into  SSB,  RTTY,  SSTV,  etc.,  this  book  is  a  must  for  you  ...  a  good 
book  for  hi-fi  addicts  and  experimenters,  too!  $4.95.* 

•  VOL.  \n  RADIO  FREQUENCY  TESTERS— LB7361— Radio  frequency  waves,  the  common  denominator  of  Amateur  Radio. 
Such  items  as  SWR,  antenna  impedance,  line  impedance,  rf  output  and  field  strength;  detailed  instructions  on  testing  these 
items  includes  sections  on  signal  generators,  crystal  catibrators,  grid  dip  oscillators,  noise  generators,  dummy  loads  and 
much  more.  $4.95.* 

•  VOL,  IV  IC  TEST  EQUIPMENT— LB7362— Become  a  troubleshooting  wizard!  In  this  fourth  volume  of  the  73  TEST  EQUIP- 
MENT LIBRARY  are  42  home  construction  projects  for  building  test  equipment  to  work  with  your  ham  station  and  in  servicing 
digital  equipment.  Plus  a  cumulative  index  for  all  four  volumes  of  the  73  TEST  EQUIPMENT  LIBRARY.  $4.95.* 

=ThE    WEU-EOuippEcl    llAiVI  shAcli 

•  THE  MAGIC  OF  HAM  RADIO- BK7312^ by  Jerrotd  Swank, 
W8HXR  begins  with  a  brief  history  of  amateur  radio  and  of 
Jerry's  involvement  in  it.  Part  2  details  many  of  ham  radio's 
heroic  moments-  Hamdom's  close  ties  with  the  continent  of  An- 
tarctica are  the  subject  of  Part  3.  In  Part  4  the  strange  and 
humorous  sides  of  ham  life  get  their  due.  And  what  of  the 
future?  Part  5  peers  into  the  crystal  balL  $4.95.* 

•A  GUIDE  TO  HAM  RADIO- BK7321 -by  Larry  Kahaner 
WB2NEL.  What's  Amateur  Radio  all  about?  You  can  learn  the 
basics  of  this  fascinating  hobby  with  this  excellent  beginner's 
guide.  It  answers  the  most  frequently  asked  questions  in  an 
easy-going  manner,  and  it  shows  the  best  way  to  go  about  get- 
ting an  FCC  license.  A  Guide  to  Ham  Radio  is  an  ideal  introduc- 
tion to  a  hobby  enjoyed  by  people  around  the  world.  $4,95/ 

•  HOW    TO    BUILD    A    MICROCOMPUTER -AND    REALLY 

UNDERSTAND  IT- BK7325-by  Sam  Greason.  The  electronics 
hobbyist  who  wants  to  build  his  own  microcomputer  system 
now  has  a  practical  "How-To"  guidebook.  This  book  is  a  com- 
bination technical  manual  and  programming  guide  that  takes 
the  hobbyist  step-by-step  through  the  design,  construction, 
testing  and  debugging  of  a  complete  microcomputer  system. 
Must  reading  for  anyone  desiring  a  true  understanding  of  small 
computer  systems.  $9.95.* 

•  LIBRARY  SHELF  BOXES -These  sturdy  white,  corrugated,  dirt-resistant  boxes  each  hold  a  full  year  of  73,  Kilobaud  Micro- 
computing or 30  Microcomputing.  With  your  order,  request  self-sticking  labels  for  any  of  the  following:  73,  Kilobaud  Microcom- 
puting, 30  Microcomputing,  CO,  QST,  Ham  Radio,  Personal  Computing,  Radio  Etectronios,  Interface  Age,  and  Byte.  Order  1  — 
BX1000-  for  $2.00 r;  order  2-7-  BX2002-for  $1 ,50  each*;  order  8  or  more  -  BX1002-  for  $1,25  each*. 


wmM 


;  ■J^j^^Sf^rW^  ^-.fw^tAKrfSi''>^^:- 


■■•■■MAHABUAMidA^mi 


style  Y 


style  W 


•  QSL  CARDS- 75  turns  out  a  fantastic 
series  of  QSL  cards  at  about  half  the  cost 
of  having  them  done  elsewhere  because 
they  are  run  as  a  fill-in  between  printing 
books  and  other  items  in  the  73  Print  Shop. 
250  Style  W-QW0250-for  $8.95*;  500 
Style  W  -  QW0500-  for  $13.95*;  250  Style 
X-QX0250-for  $8.95*;  500  Style  X^ 
QX0500- for  $13,95*;  250  Style  Y-QY0250 
-for  $8.95*;  500  Style  Y-QY0500-for 
$13.95/  Allow  6-12  wks.  for  delivery. 


t: 

.."•:■■ 

mi, 

11 : 

^S^[r-^fi     ;, 

Style  X 


•  BACK  ISSUES— Complete  your  collec- 
tion: many  are  prime  collectables  now, 
classics  in  the  field!  A  full  collection  is  an 
invaluable  compendium  of  radio  and  elec- 
tronics knowledge! 

Single  back  issue— STOOOO — 

$3,00*; 

25  our  choice— ST2500— $12.00*; 

25  your  choice— ST2501  — $25.00* ; 

5  your  choice -ST0500- $8.75*; 

1 0  your  choice— ST1 000 -$14.00/ 

•  FREE  BACK  tSSUE  CATALOGS  are  yours 
for  the  asking  . .  .  specify  73  Magazine  and/or 
Kilobaud  Microcomputing  back  issue  catalog 
when  you  send  your  name  and  address  to  us 
on  a  postcard. 


lUMMZINE 
BINDERS 


•  Preserve  and  protect  your  collection  for  a  lifetime!  Order  these  handsome  red  binders 
with  gold  lettering.  $7.50  for  1,  3  for  $21.75,  6  for  $42.00.  (Postpaid  within  USA,  please  add 
$2.50  per  order  outside  USA.)  Check  or  money  orders  only,  no  ptione  or  COM.  orders.  73 
Binders,  P.O.  Box  5120,  Phrladelphia,  PA  19141. 

Use  the  order  card  io  the  back  of  this  magazine  or  itemize  your  ord&r  on  a  separate  piece  ot  paper  and  maiMo:  73  Radio  Bookshop  •  Peterborough  NH  03450.  Be  sure  to  irv 
ciude  check  or  detailed  credit  card  fntormation.  No  C.O.D.  orders  accepted.  *  Add  $1.00  handling  charge.  Note:  Prices  subject  to  change  on  books  not  published  by  73 
Magazine.  Questions  regarding  your  order?  Ptease  write  to  Customer  Service  at  the  above  addr&ss.  Piease  allow  4-6  weei^s  for  delivery. 

FOR  TOLL  FREE  ORDERING  CALL  1-800-258-5473 


•  73  DIPOLE  AND  LONG-WIRE  ANTEN  NAS—BKIOIS— by  Edward  M.  Noll  W3FQJ.  This  is  the  first  collection  of  virtually  every  type  of 
wire  antenna  usee*  by  amateurs.  Includes  dimensions,  configurations,  and  detailed  construction  data  for  73  different  antenna  types. 
Appendices  describe  the  construction  of  noise  bridges,  iine  tuners,  and  data  on  measuring  resonant  frequency,  velocity  factor,  and 

•  THE  GIANT  BOOK  OF  AMATEUR  RADIO  ANTENNAS— With  the 
GIANT  Book  of  Amateur  Radio  Antennas— BK1 104— by  your  side, 
antennas  will  become  the  least  ot  your  worries.  Over  450  pages  of 
design  ideas,  theory  and  reference  data  make  this  book  live  up  to  its 
title.  The  7  chapters  cover  everything  from  basic  antenna  theory 
through  designs  for  DIY  accessories,  as  well  as  dozens  of  antenna 
J^  Giant  aooic  designs*  Whether  planning  to  build  or  buy.  design  or  admire,  test  or 

^LmS^i^^  ^^i^y  ^  ^^^  antenna— this  is  the  book  for  you.  From  the  editors  of 

w  til 


73;  published  by  Tab  Books.  Hardcover  $12.95. 


#73  VERTtCAU  BEAM  AND  TRIANGLE  ANTENNAS— BK1069— 
by  Edward  M,  Noll  W3FQJ.  Describes  73  different  antennas  for 
amateurs.  Each  design  is  the  result  of  the  author's  own  ex- 
periments covering  the  construction  of  noise  bridges  and  antenna 
line  tuners,  as  well  as  methods  for  measuring  resonant  frequency, 
velocity  factor,  and  standing-wave  ratios  160  paoes,  S5.50/ 

•  VHF  ANTENNA  HANDBOOK— BK7368--The  NEW  VHF  Antenna 
Handbook  details  the  theory,  design  and  construction  of  hundreds 
of  different  VHF  and  UHF  antennas  ...  A  practical  tK>ok  written  for 
the  average  amateur  who  takes  joy  in  building,  not  full  of  complex 
formulas  for  the  design  engineer.  Packed  with  fabulous  antenna 
projects  you  can  build.  S5,95,* 


•  PRACTICAL  ANTENNAS  FOR  THE  RADIO  AMATEUR -BK1015 

—  A  manual  describing  how  to  equip  a  ham  station  with  a  suitable 
antenna.  A  wide  range  of  antenna  topics,  systems,  and  acces- 
sories are  presented  giving  the  reader  some  food  for  thought  and 
practical  data  for  construction.  Designed  to  aid  the  experienced 
ham  and  novice  as  welL  Only  S9.95/ 

•  TTL  COOKeOOK-8K1063-by  Donald  Lancaster.  Explains 
what  TTL  is.  how  it  works,  and  how  to  use  it.  Discusses  practical 
applications,  such  as  a  digital  counter  and  display  system,  events 
counter,  electronic  stopwatch,  digital  voltmeter  and  a  digital  tach- 
ometer. S9,50. 

•  CMOS  COOKBOOK-BK1011-by  Don  Lancaster.  Details  the 
application  of  CMOS,  the  iow  power  logic  famity  suitable  for  most 
applications  presently  dominated  by  TTL.  Required  reading  for 
every  serious  digital  experimenter!  $10.50/ 

•  TVT  COOKBOOK— BK1064— by  Don  Lancaster.  Describes  the 
use  of  a  standard  tetevision  receiver  as  a  microprocessor  CRT  ter- 
minal. Explains  and  describes  character  generation,  cursor  con< 
trol  and  interface  information  in  typical,  easy-to-understand  Lan- 
caster style.  $9.95.* 

•  RTL  COOKBOOK—  BK1059— by  Donald  Lancaster.  Explains  the  how  and  why  of  RTL  (Resistor-Transistor  Logic)  and  gives  design 
information  that  can  be  put  to  practical  use.  Gives  a  multitude  of  digital  apptications  ranging  from  the  basic  switch  to  the 
sophisticated  counter.  240  pages;  $6.50.* 


SSTV 


•  SLOW  SCAN  TELEVISION 
TAPE— CT7350— Prize-winning 
programs  from  the  73  SSTV 
contest.  Excellent  lor  Demo! 
$5.95/ 


73  CODE 
TAPES 


Any  Four  Tbdok  For  115. 
•4.95  Each  I" 


I 


ir 


ji 


It 


GENESIS 


II 


5  WPM—CT 7305— This  cs  the  boplnnllig 
iap«  fof  people  wtio  do  not  know  the  codo 
mail.  II  taKes  thefr  througti  the26  lettors. 
10  nuinberB  and  n^ce^^ary  pimctuatloriH 
compJet6  witti  practice  every  step  o1  the 
way  using  tUe  newest  blitz  teaching  tech^ 
niqu^s.  f1  Is  almost  fntracy{Qus>[  In  one 
hour  many  people— including  ktds  of  ten 
—are  able  to  master  the  code.  Ttte  ease  ot 
Isaming  gives  confidence  to  beginners 
wfio  might  Qthenwise  {Irop  ouL 


"THE  STICKLER" 


COURAGEOUS 

20+  WPM-CT732D— Code  is  what  get^ 
you  when  you  go  for  the  Extra  class  li- 
cense. It  is  so  embarrassing  tc  pan^c  out 
lust  because  you  didn't  prepare  yourself 
with  this  tap«.  Though  this  Js  only  one 
word  faster,  the  code  groups  are  so  dliff  I- 
cult  that  you"n  almost  fall  asleep  copying 
the  FCC  stuff  by  coiti  pari  son  Users  report 
Ihat  Ihey  can  t  believe  how  easy  20  p«r 
really  js  with  tt>ls  lantastic  one  houi  lape. 


fi 


OUTRAGEOUS 


II 


■  I 


t+  WPM— CT7306— This  is  the  practice 
Laf)«  fof  the  Novice  and  Technician  li- 
censes, (t  IS  mad€  up  of  one  solid  hour  of 
code,  sent  at  the  official  FCC  standard  |no 
other  tape  we've  f^eard  uses  these  sian- 
dards,  so  ma:ny  people  flunk  the  tode 
when  they  are  suddenly — under  pressure 
—faced  With  characters  serit  at  O  wpm 
afril  spac^  for  5  wpm)  This  tape  is  not 
rTtemorizable.  unlike  the  zany  5  wpm  tape. 
s»nce  ttie  code  groups  are  entirely  random 
clvaracters  sent  in  groups  ot  five. 


SACK  BREAKER" 


2S  +  WPII— CT73;25— Tliis  is  the  tape  for 
that  small  group  of  overachteving  hams 
who  wouldn  t  be  content  io  simply  $ai:i$ty 
the  code  requirements  ot  the  EJtira  Class 
license.  Ws  the  toughest  tape  weVe  qoi 
a  nd  we  Neep  a  peiman  enl  f  1 1  e  of  ham  s  who 
have  mastered  it.  Let  us  know  wn^n  you  re 
up  to  sp^Kf  and  wen  mscrit>e  your  name 
in  73*5  CW  "Hall  of  Fame. 


groups 
ill  I 


13+  WPM-CTT313— Code 
again,  at  a  brisk  13  per  so  you  will  t>e  ai 
ease  when  you  tit  down  in  front  oi  the 
steety-eyed  government  in5p«ctor  arnd  he 
starts  sendihf]  you  platn  iangua^e  ai  0€ily 
13  pef  You  ne«d  this  extra  margin  to  ovet- 
come  the  panjc  which  ts  universal  In  the 
test  srtualFons  VVh«n  you>e  Sp^nt  your 
money  and  time  to  lake  the  tffSt,  you*II 
thank  heavens  you  had  this  back-breaking 
tape 


'Use  the  oidef  card  *r\  ihe  back  of  thts  magajrtne  or  itemize  your  order  on  a  separate  piece  of  paper  ar>0  ma  it  (o:  73  Radio  Bookstiop  •  PetertxMough  NH  Q345fi-  Be  sure  to  iiv* 

cJiude  chedt  or  delaiied  credit  card  information  No  CO  D  orders  acceprfl<3  *  Add  $i  00  handling  chaige  Note:  Prices  sybfect  to  Change  on  bcKsks  not  put^iished  by  7^ 

Mlf^rve  QuevliOns  reqardtng  your  order?  Please  wrfie  to  Custorner  Service  at  the  above  address  F^ease  allow  4-6  weeks  for  delf¥«rv- 


J 


FOR  TOLL  FREE  ORDERING  CALL  1-800-258-5473 


q)EflLER 

DIRECTORY 


San  Jose  CA 

Bay  ma£%  newist  Amntcui-  B«dio  iloce.  !4ew  It 
used  Amateur  RaflfosaJb  At  scrHce,  Wr  fntuiv 
Ken*  nod,  ICOM,  %DK,  V^eni.  Tm  T«. 
VHF  Enjdnemne  tk  amm,-  mofr-  *iii*wff  naiiio^ 
Inc.,  ITihSo.  BKicofnA^.  Sun  Jape  CA9S12S. 


San  LeandroCA 

puMisIt  tlv  fno^  iiDCiiratF  P.C.C  mam  {.ifcp*^ 
TVtkin  Duinial  m  ihr  c<»unirv  KctmliT^  to  let- 
tan  cm  ftb  (nxn.  buns  natkinwtdk'.  Ccta-r»l .  Ad- 
vKDced,  ftfkl  E.ii:tr«  Oaii  mjuiuab  ■ii'ttiUlilc. 
Bmsh  EilacmtldaAl  Servien.  51$  EitltrfUW 
A^^ftur.  P.O^  Hm  21IS.  &«n  LiBUiIro,  CA 
»|S77.  352-5420. 


Denver  CO 

Experimenter*  pijuiHn^rt  Elprtronk  and 
mechamcal  ceMnpontvta  fwr  oomputcr  pi*i:JjTlr* 
audio  j^uplt,  hams,  robo*  butwn,  eMwri' 
mentETL  Opat  m.  dav%  m  wodt.  Catrw«v  Elec* 
|fai^9  Cwp.«  ZS39  W.  Mth  Ave..  Doivvr  CO 

Uficasvilk  CT 

Cushcnift,  B«ne:h<*r«  Hv-Gdn.  Tdet.  B«ilcer& 
Williamson,  Nye^Vikinis,  HustJei.  KiF},  Cull- 
bcwk,  Miinrh.  Utuailltt,  OK.  S«xlon«  AHKL 
Books^  Used  e*|iilpmt»nt.  EWtrnnlc  [mrts  ^ml 
VOBf^arvEs,  fr**-  ejitalf}^.  l>iWMivan  l-!l«<:titifii£A, 
Im.^  2510 Norwich,  New  LaiidcAi  Tpkc,  UiKu- 


Columbm  GA 

KENT^CKID— YAESl'     HRAKE 
The   woHdv    iiixiPil;    EuiiUiritu^   jiiiuiti'iir   ^hnw- 
rtioml   You  gotttt  sm;  It   \\t  \K']ievv   il!    Ruttid 
WholefuJe^  2012  Auhum  Avfmjt',  Cnhnnliia 


Bobe ID 

Adzen,  Aniidnn,  AmeQty^  ABRT-,  flfcW* 
CaMhook,  {JoUln^  Cii^^liCruri,  DeiHtcm, 
Hm-tjer,  ICOMp  Jim  Pak,  KDK,  MFJ.  NFC, 
Nyt,  Sams,  SST,  Swan,  Te-n-Ttx;,  Wanwir, 
Wilstm  CuAlom  Eleclmnitx.  1209  Bmadway, 
Boise     ID     S370(i.     Byh     W7St;     3^4- 

Frcslon  ID 

Ross  WHTBYZ,  has  I  hi'  Ltirge^l  SUtek  ^4  Ania 
terjT  C«ir  in  iht*  Intermtinntain  \Vi-\i  and  tlii" 
B*!5+  PricR!i.  flull  mi-  kn  all  voat  iMin>  nifT:?dv. 
Boss  Dislributinfi,  7S  So.   Slated  FteUm  ID 

Terre  Flautc  IN 

Your  ham  h^idqiuiisTi  kiailtvl  Ln  the  heart  of 
the  midiA-ftsI  HriiHtef  ^edmnics.  Inc.,  438 
Modov.^  ShAppiim  CoilH.  I'.O.  b<n,  2001. 
Tenr  Haute  LV  47802.  23S-1456. 


Littktqn  MA 

The  bMD  flow  trf  N.E.  ^tW  C*n  f^'  on,  Kmv- 
wtwd.  ICOM,  \^  ibtm.  fHBi,  DniTron.  IlLM 
un}E.  B&VV  fwiteiis  h  wattn>p*ert,  WhWlct 
ndar  ^ectofii,  Bmcat^  Rejiieno .  anteriEUii  b>' 
Laiioi,  Wdsofi.  Hitilkr,  CaVI  TEl^:C»l 
Ice.  Cjflntim  iiriin  tf«»*«  Al  Oertmnks^  E75  Gnal 
Bd.,  Hi,  llfl.  littklon  MA  01460.  48«-30lO. 


Laurel  MD 

Kewwxjod,  D«l»,  itXJM,  Ten-Tec,  Sw«u 
Dmtron.  Tempo  and  EBany  ham  MCUMric^ 
Afej  cewiputtsi  b>  App*?  *nrf  EiJdh-  Ttw 
Conun  Cen^,  Ifie,.  I.*ui«l  Plau— HL  106, 
Laiinl  %iD  20SIII.  TSt-INCW. 


SL  Look  MO 

Eipenmenter'^  paiKlisd  Elfl^tranic  and  oie- 
thanicid  cnm|)onpnU  for  camputLt  people, 
audio  ^Ksmk^  hMuu^  robol  biildpn;,  ^^"' 
mentten.  C^iefi  six  davs  a  uicEk.  Calrwav  Oec- 
tnncs  Cofp..  Si^2S  Fa^  Blvd^  S*.  Ijnuh 
MO  63110,  42:<«iie. 


Syracusfr-Rome-Ulica  NY 

FeKttiKnip  Kemhtxid,  Vasu,  ICOM.  Drafe, 
Tei^TH?.  Swan.  EfenTroii,  ,\ipba,  flsibo*.  MF], 
Tempa.  AstnHu  KUM,,  Hy  Gain^  \(aaln% 
L^fieft,  Cushcnft.  Hiatkr,  l^tini  PnKfaicts-  You 
wfni'r  he  dhapooinled  » trh  equipnieitt'ser\-icf . 
Radii)  Worlds  Oneida  Counlv  Airport- 
TemiinaJ  Building,  Oriskaity  ST  13424, 
33741303. 


Phila,  FA/Camden  NJ 

W«\vguidp  i  cuaaud  irocrowa*^  comp<inrfil> 
&  ftpJipmi'nt.  IjliiJia[of>^  grade  tiest  imtru 
meats,  ptmef  VLipplks-  B«>"*  seil  6c  tradi^  ail 
popidar  mates.  HP,  CR.  FXH,  ESI,  Sorenseti, 
|{n|^.  etc.  Ledronic  Besearcb  Labs.,  1423 
F«ry  Aw,.  Qioickii  NJ  0&104,  54MaOO. 


Columbus  OH 

All  ma^r  brands  featured  irii  the  bigi^t  aid 
best  hain  stfir*  for  miles  around.  Come  in  and 
hfcUt  the  ktKtbs  bt-fott-  vhu  buy.  Untvenul 
Amateur  I^adin,  Inc.,  12S0  AidaDr.,  Reynnlds- 
hurg  (Columbus I  OH  43068t  Hli4i-42li7. 


Houston  TX 

Ex|X'rinMJJiter\  psiradiMrt  Eitsctrnnic  and  me- 
ehanital  naruponente  for  computer  people, 
uudin  iXHiplf.  hams^  fobrrf  biiildnn;,  esptrl- 
menliir?,.  Opvn  nix  clavs  a  wt^k,  Gatevi^av  Elc<> 
tmnics  Inc..  Stel2  fclaritcsnest*  Houvtcm  TX 
770fl3,  BTfikeSTS. 


San  Antonio  TX 

Cnniplfte  2  wav  service  shop.  Call  C^t'c^ 
Wrd^^SP.  Sdlinfj  Anknuiii  SpodalisL^,  Avaiiti, 
Azden,  Bird,  lly-gaiti,  Standard  eommunieit- 
Hf>m,  Gc'fiavc.  Heiirv%  CtisliCraft,  Dielt^fcric. 
Huirtler.  ICOM.  MF],  N\^,  Sbure.  S^ an,  Tcm- 
jMv  Tt'ti  Tw-  and  others.  .A,pplianc^  flr  Ff|iiip- 
mcnt  Co.*  Inc.,  2317  Vante  Jadison  Rtad,  San 
Antonit*  TX  78213.  734-7793. 


DEALERS 

Yfntr  tvmpantj  name  and  fnessagjp 
can  contain  up  to  23  words  form  Ut- 
ile as  $150  yearly  (prepaid),  or  $15 
per  month  (preiKiid  quarteriy).  No 
mention  of  mail-order  business  or 
area  code  permitted.  Directory  text 
and  payment  must  reach  us  60  days 
in  adiHjnce  of  pubiication.  For  ct- 
antple,  adtertvnngfor  the  Februanj 
issue  mttst  he  in  our  handi  hy 
December  ht.  Mail  to  73  Mag- 
aziju\  Peterborough  NH  034S8. 
ATTN:  Nancy  Cmmpa. 


PROPAGATION 


J.  H.  Nel&on 
4  Piymouth  Dr. 
Whiting  NJ  QB759 


EASTERN    UNITED    STATES    TO 


GMT: 

00 

02 

04 

n 

Off 

^t> 

IJ 

14 

IE 

ii 

a 

22 

A4.ASKA 

1AA 

U 

7 

T 

7 

1 

7 

? 

14 

14A 

21* 

1 
J** 

AjratNTuwa 

14 

TA 

7 

71 

71 

J 

14A 

3t 

2t* 

?IA 

JIA 

11* 

jujsriu4ia 

Jl 

14 

m 

ra 

rn 

rt 

■  z 

^*fi 

21 

31i 

It* 

31A 

CJUVAL  fCME 

14 

f 

7 

7 

T 

7 

44 

;i* 

71* 

IfA 

?tA 

ai 

!   EMCtAiiO 

7 

7 

7 

7 

7 

T 

14 

21* 

51* 

14A 

14 

} 

KAVUIII 

»A 

14 

7B 

7 

t 

7 

1 

TB 

14 

SlA 

21A 

31A 

IW7tA 

7 

T 

71 

fa 

7B 

Tfi 

14 

14* 

t4 

m 

m 

T 

j   jaTAM 

I4A 

f4il 

TV 

71 

7 

IF 

7 

7B 

73 

Tfl 

t« 

t« 

HEintro 

T*» 

TA 

7 

7 

'     7 

7 

7 

14A 

7IA 

?1A 

riA 

31 

FMLIPrittES 

J4JI 

1«t 

?B 

m 

79 

TB 

79 

I4S 

%m 

14S 

I4i! 

14 

nfCMto  nico 

14 

f 

J 

1 

r 

r 

14 

21* 

?i* 

?TA 

..  '«! 

sourmAfftiCA 

14 

n 

y 

7m 

71 

94 

2-i 

TT* 

JTA 

31At2-        -Ja! 

1    mS-S.fl. 

T 

1 

? 

} 

J 

J5 

34 

L  21 A    n 

a 

"f  '■ 

MESTCJQAST 

" 

14 

I 

7 

■    - 

7 

7 

14 

anA 

«A 

7« 

31a| 

CENfR 

Al 

_    UP 

_ 

411 

EE 

D 

STAl 

PES 

TO: 

1 

aiASKJI 

it    1 

t4 

7 

7 

7 

7 

7 

14 

HA 

21A 

21A 

ARQCNTINA 

» 

14 

f 

m 

7a 

14 

31 

21A 

7IA 

?1A 

37* 

ALfSmiALia 

3tA 

14      1      IS 

!■ 

T9 

70 

IQ 

7B 

M 

31 

11* 

ItA 

CAMAL  ZONE 

14 

rA 

J 

7A 

21 A 

?1A 

ItA 

7tA 

31A 

W9^L*Mt 

T 

? 

T 

73 

14A 

riA 

14A 

14 

7B 

HAMAIt 

31A 

14 

T 

7 

7 

14 

3tA 

3tA 

;21A 

IMDIA 

TB 

m 

™ 

7B 

TB 

7B 

7B 

m 

14 

7B 

7B 

71 

M^AN 

?TJi 

•4 

78 

7P 

7 

7 

7B 

71 

t4B 

31 

MCXfCd 

14 

J! 

V 

7 

14 

21 

2tA 

II* 

Jl 

PHILff«*»iK 

MA 

14 

7B 

7« 

IV        IS 

TB 

? 

I4e      14ft 

T4S 

14 

niviiTQi  ntco     , 

14 

7 

7 

7 

7A 

31 

?1A 

71A 

.1 

1\ 

SOUTH  AFflteA 

H 

n 

7 

7H 

7e 

7B 

It 

JIA 

31A 

31A 

71A 

I4A 

u.s.s  n 

!'■ 

7 

} 

7a 

Jlfi 

14A 

T4A 

V^B 

m 

79 

WESTE 

Rr 

J    UNITED 

STATES    TO: 

31 A 

14 

J 

IF       1 

5A 

7A 

T4 

21 

3Tfl 

ANOiNTINA 

31A 

14 

7A 

7B 

T& 

7B   ■ 

14A 

21 A 

2tA 

2tA 

31A 

AUSTRALIA 

:}iA 

31 

14 

7a 

7a 

7B 

7S 

14 

31 

21A   , 

J21A 

CAhlAL  ZOfVC 

?i 

14 

1 

? 

14A 

21A 

21A 

SlA 

21A 

ENOU^ND 

7D 

7 

7 

;fl 

14EI 

21fl 

I4A 

149 

m 

HAWAII 

^Xfk 

21 

t4 

7A 

7 

7 

14 

aiA 

31 A 

31 A 

INDIA 

7B 

14 

70 

7b 

/H 

/H 

Tfl 

7B 

t4i 

79 

7B 

TB 

JAPAN 

21A 

14A  1 

14i 

7B 

7 

7 

7 

79 

149 

7\A 

MEXICO 

21 

14 

7 

7 

7A 

7\ 

Si  A 

31 A 

31iA 

PHIIIPPINIES 

31A 

14A 

14a 

TB 

?B 

7B 

TB 

1 

149 

149 

14B 

14 

PUERTO  RICO 

71 

14 

7 

T 

HA 

21A 

2TA 

2tA 

?1 

SOUTH  AFRICA 

^1 

14 

7 

:?fl 

7S 

7B 

7a   . 

14 

31A 

51A 

giA 

14* 

U.S.S.  A. 

/» 

7 

7 

IB 

70 

7B 

7B 

14 

7B 

71 

7B 

iASTC^Atr 

J1 

14 

t 

1 

14 

31ft 

71 A 

31 A 

1\A 

A  = 
B  = 
F  = 
SF 


Next  higher  frequency  may  also  be  useful 
Difficult  circuit  this  period 
Fair  G    =   Good  P    =   Poor 

=   Chance  of  solar  flares 


mun 

Pfiori 

tu* 

wad 

llfU 

fri 

**t 

1 

F/SF 

2 

F/SF 

3 

F 

4 

G 

5 

G 

6 

F 

7 

G 

8 

G 

9 

G 

10 

G 

11 

G 

12 

G 

13 

G 

14 

15 

F 

16 

G 

17 

G 

18 

19 

F 

20 

F 

21 

G 

22 

G 

23 

Q       i 

24 

F/SF 

25 

P/SF 

26 

F 

27 

F 

28 

G 

29 

G 

30 

G 

31 

6 

73  Magazine  ■  December*  19B0    225 


m 


LiST  oF  AdvERTISERS 


'Please  contact  Iha^e  adverU&ers  directly. 


To   receive   foil   information   from  our  advertisers 
please  complete  the  following  postage-paid  card. 


R.$.Na  Page 

AEA/Advariced  £fect-  Applica.,  inc. 

.32,  1^5 

3       AED  Electronics;, . .... ,.,... . .  .76 

362  A.R  Systems, 169 

I  Ad  i  r ondac  k  Rad  i  o  S  u  p  p  I  y ,  1  nc. . .  1 69 

31 4  Al  liaince  Mfg.  Co: 45 

5      Amateur-Wholesale  Etectronics 

.,. 23,  216 

7  American  Crystal  Suppiy 173 

334  Amidon  Associates 171 

301   Appli.  &  Equip.  Co.,  Inc. 173 

8  Aptron  Laboratories .163 

Associated  Radio, . , 220 

3&B  Astron  Corporaiion. . . , 9T 

10  Avanti  Researcli  &  Develop 109 

II  Barker  &  Williamson 165 

483  Barker  &  WiiSiamsor> 186 

12  Buiiet  BoGtronics 208,  209 

477  Centurion  internailonal 186 

13  Clegg 101 

89  Ctutterf ree  lvlo<Jijiar Consoles. ...  89 

14  Cumm.  Cenier,  r^E 97, 147 

382  Comm.  Concepts,  Inc 171 

377  Comrnynications  Elect rgr^tcs, , .  196 

15  Corr^m.  SpeciaJi&ts. 10,  11 

16  Grown  Micro  Products. .77 

70  CubJc  Gomrrunicafions,  inc 83 

20  D$l  Instruments. 21 

330  DebCQ  Electronics 111 

*  Pauli  Daviis  Electronics. 104 

346  Data  Service 173 

365  Larry  Dennison 146 

Digital  Research  Parts 210 

19     R.  L.  Drake  Co. , . . , 30, 31 

80  Microcomputing , 149 

Erickson  Comm 105 


R.S.  No.  Pag» 

336  ElecifOComponents  Div 173 

323   Fox-Tango  Corp. 86 

27     GJ.S.M.O 125 

26    Germantown  Amat  Suppiy 136 

478  Giifer  Associates. 186 

23     Godbout  Electronics.  - 21 S 

352  Grove  Enterprises . 29 

378   HVB. 173 

345  Hal  Comm 19 

31  Hal-Trontx. 29.  45 

30    The  Ham-Key  Co. , , 56 

32  Ham  Radio  Center. 95 

33  Hamtronics,  NY. 211 

476  HamtroniCS.  NY 186 

481  Heath  Co _  .  _  , .  1 06 

34  Henry  Radio Gov  II 

305  Hustler,  Inc. 131 

363  l-Can  Company. 1 69 

iRL. 146 

iCOM...., ,.. 9,15 

35  Info-Tecti,  inc .105 

36  i nternatsonal  Crystal  Vifg 90 

38  Jameco  Electronics. . . ...  219 

479  Jameco  Electronics ^ 32 

39  Jan  Crystals. 146 

364  Jim-Pai^  Electronic  Comp,  ....  80,81 
Kantronlcs, ... 4 

482  Karetron  Engineering 188 

KB  Microcomputing. 149 

Kenwood. Cov  IV.  7 

375  Herb  KrecKn^an  Co. ..,.,. .  —  104 

LaRue  Electronics , 169 

43     Lunar  Electronics 17 

47  M FJ  Enterprises 34, 35 

48  MHz  Electronics. ..........  198-207 

S6     Macaw  Electronics 75 


R.S.NO. 


Page 


365  MELCO  Enterprises 163 

44  Macrotronics , .  77.  91 

45  Madison  Electronics 27 

46  Maggi:ore  Electronic  Lab. ......  104 

369  Magnetic  Call  Sign 169 

40     Micro  Control  Specialties. , ,  78,  136 
313  Micro  Management  Systems 28 

50  MicrocraU  Corp 171 

383  Micro-80,  Inc 171 

51  Microlog  Corp. 71. 103 

52  MidCom  Electronics.  Inc 70 

.388  Mor-Gain , 51 

318  National  Comm.  Group  Co 74 

54  OK  Machine  S  Tool. . , .  - 137 

55  Optoelectronics,  inc.. ....... ....3 

Orbit  Magazine... 114 

57  P.  C.  Electronics. 57 

346  Page!  Electronics. 146 

*       Palomar  Engineers. 25 

380  Panasonic . , . .  33 

58  Poly  Paks 89 

60  Quest  Electronics 197 

61  Radio  Amateur  CalibookH  Inc. 91 

381  Radio  Systems  Tech.,  Inc 171 

Radio  World 97,  171 

62  Ramsey  Electronics. ......  214,  217 

Roctiester  Hamfest. 18 

65  S-F  Amateur  Radio  Services. .  . ,  105 

374  SK  Electronics. 104 

376  SMP 79 

64     Semi  conductors  Surpi  u s 

195,212,213 

333  Sentry  Mtg.  Co.... ...  165 

'       73  Magazine 

79.115,174,221-224,226 

66  SignaEcralters 76 


R.5.  No^  Pig* 

367  Slep  Electronics. 79 

434  Sony 1S7 

360  Soundpower 163 

317  Space  Electronics. . , 104 

309  Spacecoast  Research —  , 173 

67  Spectronics, 215 

68  Spectrum  Comm 62,  63 

73  TET,  USA.. 99 

*  Ten-Tec,  Inc 13 

76  Trac  Electronics, , , , , , .  25 

77  Tufts  Radio  Electromcs 150-161 

361  UHF  Sales  &  Service 104 

37    UPI  Comm.  Systems,  Inc 111 

Universal  Communications  —  173 

387  Urban  Engineering 51 

311  Vanguard  t^bs , ...  173 

373  Van  Gorden  Engineering . . . ,  77 

90     VoCom  Products  Corp ,131 

79  Wacom  Products. , . .  163 

80  Western  Electronics. 171 

Wilson  Systems,  Inc 90,116-119 

82     Xitex  Corp. 76.  104 

33     Yaesu  Electronics  Corp, 

Cov  III,  67,93 

336  2  Associates; .  „ . . , 173 


T^MAGAZIHB 


Books  r  ETC. 

Catalog  ^  1(«m  lyrics 

BK1016       73  DiPOLE  &  LONG  WIRE  ANTENNAS 

,..., , „„,.„...,.,..$  5.50 

STOOOO       73  B  AC  K  1 SSU  E...i.i.;^..i. $  3,00 

ST25O0  73  BACK  ISSUES— 250URCHOiCE.S12  00 
ST0500  73  BACK  ISSUES— 5  YOUR  CH0ICE.$  6-76 
ST1000       73  BACK  ISSUES- 10  YOUR  CHOICE 

.,..„,. ...$14.00 

ST2501        73  BACK  ISSUES— 25  YOUR  CHOICE 

BK7307  BEHIND  THE  DiAL ..- $  4.95 

BK7309  CHALLENGE  OF  160.  ..„.,.. $  4.95 

CT7305  CODE  TAPE— 5  WPM... S  4.95 

CT7306  CODETAPE-6+  WPM S  4.95 

GT7313  C0DeTAPE-l3+  WPM $  4.95 

CT7320  CODE  TAPE— 20 -t- WPM. $  4.95 

CT7325  CODE  TAPE— 25-1-  WPM $  4.95 

CT7394  CODE  TAPES  (ANY  FOUR  ABOVE),,,. SI  5.95 

BK730a  THE  CONTEST  COOKBOOK.. $  5.95 

BK73ei  40  COMPUTER  GAMES ..$  7.95 

BK7304  GIANT  BOOK  OF  AMATEUR  RADIO 

ANTENNAS,. -.„..„.....; .$12.95 

BK7322  HOBBY  COMPUTERS  ARE  HERE $  4.95 

BK7325  HOW  TO  BUtLD  A  MICROCOMPUTER  & 

REALLY  UNDERSTAND  IT $  9,95 

BKIOZe  (COP  AMP  COOKBOOK ..„ .,..$1295 

8K7312  MAGIC  OF  HAM  RADIO.... $  4.95 


To  order,  complete  the  following  postage-paid  card,  or  itemize  your  order  including 
detailed  credit  card  information  or  check  and  mail  to: 
73  Magazine/Mail  Order  Dept./Peterborough  NH  03458. 


catalog  n                   Hem  Prlc« 
BK1033  MASTER  HANDBOOK  OF  HAM  RADIO  CIR- 
CUITS  3  8.95 

BK7340  THE  NEW  HOBBY  COMPUTERS...,..„$  4.95 

CT7300  NOVICE  THEORY  TAPES. $15.95 

BK7310  OWNER  REPAIR  OF  RADIO  EQUIPMENT 

$  7.95 

BK73Q5  POWER  SUPPLY  HANDBOOK $  7.95 

BK1015  PRACTICAL  ANTENNAS  FOR  THE  RADIO 

AMATEUR................. $  9.95 

BK7302  PROPAGATION  WIZARD  8  HANDBOOK 

^.'..ii.......... ................ 1,1... i....,....-, , ...i.ith    D.?D 

QW0250  QSL  CARDS-STYLE  W— 250 $  0.95 

QW05OO  QSL  CARDS— STYLE  W— 500 $13.95 

QX0250  QSL  CARDS-STYLE  X-250. ,...$  8.95 

QX05OO  OSL  CARDS— STYLE  X— 500 $13.96 

QY0250  QSL  CARDS— STYLE  Y-250 ....$  8.95 

QY0500  QSL  CARDS- STYLE  Y— 500.. $13.95 

BKlOa  RF&D(G1TALTESTEQUIPMENT $  5.95 

BK7347  RTTY  HANDBOOK... $  5.95 

BK1059  RTL  COOKBOOK $  6.50 

eXiOOO  SHELF  BOX-1 , .S  2.00 

BX1001  SHELF  BOXES-2-7.. ...|1 .50  each 

8X1002  SHELFaOXES— 6ANDUP $1.25each 

BK7351  SSB  THE  MISUNDERSTOOD  MODE..$  5.50 

CT7350  SSTV  TAPE....... $  5.95 

SG1081  STUDY  GUIDE— ADV.  CLASS ...$  6.95 


Catalog  #  Item  Pric« 

SG 1 080       STU  DY  G  U I OE—  EXTRA  CLASS. . .. . ...  .$  5.95 

SG735B      STUDY  GUIDE-GENERAL  CLASS...$  5.95 

SG7357       STUDY  GUIDE— NOVICE  CLASS $  4.95 

LB7359       TEST  EQUIP  LIB  VI— COMPONENT 

TESTERS ...., $  4.95 

LB73eO       TEST  EQUIP  LIB  V2— AUDIO  TESTERS 

...,.,.„.., $  4.96 

LBTSei        TEST  EQUIP  LIB  V3— RADIO  EQUIP..!  4.95 
LB7362       TEST  EQUIP  LIB  V4— ICTEST  EQ....,.S  4.95 

BK7348      TOOLS  &  TECHNIQUES......... ....,...$  4.95 

BKl0e3      TTL  COOKBOOK ,.. $  9.50 

BK1064      TVT  COOKBOOK , S  9.95 

BK7382       UNDERSTANDING  A  PROGRAMMING 

MICROCOMPUTERS ..$10.95 

BK1069       VERTICAL  BEAM  &  TRIANGLE  ANTNS 

....$  5.50 

BK736B      VHF  ANTENNA  HANDBOOK «..t  5.95 

BK7370       WEATHER  SATELLITE  HANDBOOK.*  4.95 


magazine 


Peterborough,  n.h.  03458 


226     73  Magazine  •  December,  1980 


With  the  Yaesu  FT-480R  . 


TWO  METERS  COMES  ALIVE! 


SSB  activity  is  flourishing,  repeater  activity  is  at  an  all-time  high,  and 
OSCAR  users  are  breaking  records  every  day.  Let  the  FT'480R  step 
you  up  to  space-age  performance  on  SSB,  CW,  and  FM: 


Features 


Coverage  of  143.5  - 148.5  MHz  (good  news  for 
you  MARS  operators) 

USB,  LSB.  CW  and  FM  operation  are  all  built-in 

Four  channels  of  memory,  with  priority  channel 

Two  VFOs  for  unusual  repeater  splits 

Convenient  synthesizer  steps:  10  Hz,  100  Hz,  or 
1  kHz  per  step  on  SSB/CW,  1  kHz,  20  kHz.  or 
1 00  kHz  per  step  on  FM 

Scanning  control  from  microphone 

Highly  effective  noise  blanker 

Receiver  offset  tuning  for  following  Doppler- 
shifted  signals 

SAT  switch  allows  shifting  of  transmit  frequency 
during  OSCAR  operation  (many  rigs  cannot 
QSY  on  TX) 

30  watts  DC  input  on  FM/CW,  30  watts  PEP  in- 
put on  SSB,  HI/ LOW  power  selection  on  FM 
andCW 


ft 


p,stt 


,.K|\ 


M'^'^*'''^/^'* 


Built-in  tone  burst  generator 

Bright  LED  signal  strength/relative  power  output 
level  meter 

Easy-to-read  fluorescent  display  of  operating 
frequency  and  memory  channel 

Front  panel  switch  for  zeroing  synthesizer  to 
convenient  step  when  changing  modes  from 
SSB/CW  to  FM 

Requires  13,8  VDC,  negative  ground 

Avaiiabte  Options: 

FP-80  AC  Power  Supply 

FTS-64E  Synthesized  CTCSS/Burst  Encoder 

PricB  ancf  specfffcatfons  subject  to  change 

without  notice  or  obligation 


Did  You  Know  .  .  . 

Yaesu  now  has  a  crystal-controlled 
220  MHz  FM  rig  —  The  FT- 127 


,^83 


w 


The  radiOm 


1Q80 


YAESU  ELECTRONICS  CORP.,  6S51  Walthall  Way,  Paramount,  CA  90723  #  (213)  633-4007 
YAESU  ELECTRONICS  Eastern  Service  Ctr, 981 2  Princeton-Glendaie  Rd., Cincinnati,  OH  45246 


New 


meter  direction. 


PS-20 


TR-90DO 


BO-9 


SP-120 

<il 


A  compact  transceiver  with  FM/SSB/CWplus... 


TR-900a 


Kenwood's  done  it  again!  Now, 
it*s  the  exciting  TR-9000  2- 
meter  aii-mode  transceiver.., 
complete  with  a  host  of  new 
features.  Combining  the  con- 
venience of  FiUi  with  long  dis- 
tance SSB  and  CW  in  a  very 
compact,  very  affordable 
packagop  the  TR-9000  is  the 
answer  for  any  serious  Ama- 
teur Operator!  Versatile?  You 


bet!  Because  of  its  compact* 
ness,  the  TR-9000  is  ideal  for 
mobile  installation.  Add  on  Its 
fixed  station  accessories  and 
it  becomes  the  obvious  choice 
for  your  ham  shack! 

See  your  Auttiorized  Kenwood 
Dealer  now  for  details  on  the 
TR-9000... the  new  direction 
in  2-meter  all-mode  trans- 
ceivers! 


With  vflCli  (rt- 


^KEIMV\/OOD 


Note:  Price,  specifications  subject  to 
change  without  notice  and  obligation- 


.  ♦  ,fmn\srfitr  in  attHitt'ijt  rut! in 

TRIO  KENWOOD  COfVlMUNICATIONS  INC- 

1in  WEST  WALNUT /CO  MPTON,  CALIFORNIA  90220