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I 


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December  1978         $2.00 


^A^ 


i. 


30 

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44 
48 
56 

60 

64 
82 

90 

96 

105 

114 
118 
126 
130 
132 


136 


142 


148 


152 


•I        I-       f^       -r 


WB6JPZ 


K8NQN 


WA4JTJ 


.  NWY 


W9CCI 


Endre55r  Endress 


W1SNN 


4        b      J        h 


A  DXer's  Dream  Vacation 

—  try  sunny  Montserrat  , . . , 

Close  Encounters 

^the  eyes  of  Texans  are  upon  them 

The  Schizophrenic  Triangle 

^  a  split-personality  radiator. 

From  CW  to  Computers 

—  a  digital  modulation  primer 
A  28«  TouchtoneTM  Mod 

—something  for  (almost)  nothing. . 

Space  Age  Surplus 

—  your  own  Saturn  Vf ......... . 

An  X-Band  Transceiver 

—  more  1 0CHz  fun  ....  =  ......  . 

SSTV  Recorder  Controlter 

—  replaces  your  index  finger 

Receiver  Diseases 

—and  how  to  cure  them, .».,,.., 
Aiitophaslng  for  WEFAX 

—  preserve  your  mental  health 

The  Lunch  Counter  « 

Confessions  of  a  Stripper 

—confirmed  |unkor  tells  all  . . . 

Tuned  Feeders  and  Other  Good  Stuff 

— ^ho  needs  coax?  . , WIVM 

Build  a  Realistic  S-Meter 

-"you're  S9  +  40,  OM!" , DJ3NW 

Wow!  A  Good  Portable  Receiver! 

—thanks,  PanasonK! WA2E|T' 

The  XITEX  Video  Terminal 

—  a  quiet  alternative  to  your  Model 

15 AH6AQ 

Light  Up  Your  Life 

—  the  2036  glows  digital WA4NUt 

High  Seas  Adventure  — Ham  Style 

—  part  ML  ,...,.,,..,,....,, WA6FEI 

[|2  whither  Mtcrocompufers? 

—  a  pro  looks  ahead , . » ..  WB2HJD 

3  SSTV  Meets  SWTPC:  Part  2 

—  micro^nhanced  pictures  K6AfP 


KIJML 


K4IPV 


Cawthpn 


WA4PfN 


KSCNZ 


160     Q^  A  Multi-Memory  Morse  Machine 

—using  a  Motorola  micro  , WA8TIW 

164     ^  "This  is  Your  Computer  Speaking" 

—  how  to  dial  up  your  micro. ..._,,      Sorrels 

170     [^  RTTY  with  the  KIM 

—one  more  step  .......  r ....,..,, .  VIIAKL 

174     ^DX  Delight 

-3  do-it-all  program  WA4VQO,  N3NN 

182     Big  Max  Attacks 

—  it's  W2DU  vs.  K4K1,  in  the  battle  of  the 
bazooka W2DU 

192     The  Packet  Radio  Revolution 

—  pioneers,  take  note! VE2PY 

200     This  Voltage  Standard  Is  Precise! 

--and  makes  calibration  a  snap WB6NTR 

206     The  22S  Goes  Digital 

—  add  7-segment  displays      Klfilil 

212     WARC  '79  Preview 

—  showdown  in  Geneva WA9MZS 

216     The  "Flim-Flam"  Factor 

-another  biased  article, .,,    WA2SUT(NNNfZVB 

222     Build  the  Flexi  Filter 

—  a  very  active  device W3QVZ 

226     The  Klassic  Kilowatt 

-foufailAsdoit ,... ,  K4TWJ 

230     Ham  Radio  Goes  to  School 

—  lO-year-olds  love  it. * ... . ,  ^ .  .  .  .  N2CF 

234     What's  Your  uFI 

—  a  siK-dfgit  answer K5BTV 

250     Fail-Safe 

—  protecting  repeater  batteries, WA7DP3( 

256     Code-Practice  Oscillators 

—  an  exhaustive  report .    .  . . . . .  a^. , .    W6GXH 

270     PCs  Are  Easy 

—  step- by-step  details* VE3CCE 

274     The  Games  People  Play 

—  why  not  hams?    ,  .  . WB3EUC 

287     An  Improved  HV  Tube  Socket 

^easy  modification. ,     Miller 


;» 


Never  Say  Die- 4,  Letters- 14.  RTTY  Loop- 16.  Ham  Help -16,  76,  80,  116, 134,  277,  Looking  West -18,  DX-20.  New  Products - 
22,  Contest5-26,  Faces,  Places-70,  Social  Events-BI,  Dealer  Directory- 112,  Corrections- 116,  278,  AMSAT-134,  OSCAR 
Orbits- 27B,  CARf  —  27B,  1978  Index- 264,  Propagation- 321 


-   SI 


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Frequency  Coverage 

Channel  Spacing 

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lower  of  operation.  This  will  enable  you  to  use  the  high  power  when  needed,  then  later  switch  to  low  j 

power  to  conserve  battery  drain  for  extended  operation.  J 

■       IN  ADDITION:  al[  Mark  Series  Radios  now  have  an  LED  Battery  Condition  Indicator  conveniently 
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Wiison  hand-helds  have  been  known  world-wide  for  exceptional 
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Now  the  Mark  Series  of  miniature  sized  2-meter  hand-hetds 
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TX-Mark  H:  500  mA 
TX- Mark  IV:  900mA 

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•  Popular  accessories  available: 
Wall  Charger,  Mobile  Charger, 
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i 


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To  obiafn  complete  specifications 

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Illustrated  is  Witson's  BC-2  Desk  Top  Battery  Charger 

shown  charging  the  Mark  Series  Unit 

or  the  60-4  Battery  Pack  only. 

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p^  Rssd^r  S^fv/cre— see  peg*  353. 


Staff 


EBfTDR/FUBLISHEn 
Wayne  Gre^fi  W2NSD/1 

eCECUTlVE  VICE  PRESIDENT 

SUmrty  Smythe 

ASSISTANT  PUBitSHER 
Jeffrey  0,  OeTfay  WB8BTH/1 

ADMINISTRATIVE  ASSISTANT 
DoUy  Gibson 

MANAGING  EDITOR 
Jolin  C.  Burnett 

ASSISTANT  MANAGING 

EOITOR 

Susan  G.  Pbllbdck 

NEWS  EDITOR 

Bm&  Smarle  WB6TOV/1 

BOOK  PUBLICATIONS 
Beth  Weston 

PRODUCTION  MANAGER 
Lynn  Panciera-Fraser 

ART  DEPARTMENT 
Craig  Brown 
Gavle  Cabana 


Bruce  He<lln 

Ci^rl  Jftck$on 

Jdn-QS  Lamoihie' 

Dion  Dw«ni 

Nofli  R.  Self  WBIARP 

Robin  U.  Sicmn 

PRINTING 
G«ry  Sreinbacti 
Dan  Moryan 

PHOTOGRAPHY 

8iii  H&Y^ii^P^ 

TediS  Putt 

TYPESETTING 
BAftwaa.  Latll 
8«n  Bedell 
Stisrtin  D«mmerle 
MifY  KiJi^el 
Holly  Walsb 

BOOKKEEPER 

Knud  E.  M.  Keller  KV4GG/1 

CIRCULATION 
Barbara  Block 
Laura  iarnicle 

DATA  ENTRY 
Mary  Kinzol 
Denlse  Loranger 

DIRECTOR  OF  MARKETING 
Robert  R.  LaPointe 

BULK  SALES  MANAGER 
Judy  Waterrman 

SHIPPING 
Elhan  Perry 
Bill  Barry 
Michelle  Witlsh 

RECEPTIONIST 
DQt\i  Jarvi« 

ASSOCIATES 

Robefl  Bakef  W62GFE 
E  H.  Bam^t  WBttlX 
ScbleyCox  WBiLHO 
Tofn  OiBt^se  W68KZD 
TeffyFoM  WB4JR 
W.  Sanger  Green 
Dave  I  Ingram  K4TWJ 
Unn  KaJtanef  WB2NEL 
Joe  KaMaf  G3ZCZ 
Bill  Pasiemak  WAfitTF 
JohnSchull2W4FA 
Waffer  Scott  KSQLZ 
Peter  Staik  K20AW 
Bill  Turner  WAf  ABI 

COMPUTER  PROGRAMMING 
Riohard  J.  Dyke  ma 
Ron  Cooke  WB9WHX 

CUSTOMER  SERVICE 
Ftofence  Goidmart 
Joyce  Tarr 
Ellen  Blanchard 

ADVERTISING 
AJine  Coutu 
Mafc4a  Stone 
WiMlaTTi  a  Vork 
Nancy  Ct  am  pa 


W2NSD/1 

NEVER  SAY  DIE 

ec//tor/a/  by  Wayne  Gre&n 


WARC  DOOM  AND  GLOOM 

Well,  here  we  are  with  all 
sorts  Of  exciting  things  going 
on  technically  in  amateur  radio, 
and  Wayne  Green  Is  preaching 
doom.  One  day  I'm  up  on  a 
mountain  working  with  Chuck 
WA1 KPS  to  make  some  record- 
breaking  contacts  on  10.5  GHz 
and  d  couple  days  Jater  I'm  talk* 
ing  to  a  group  of  hams  at  an 
ARRL  convention  about  the 
possible  loss  of  most  or  all  of 
our  ham  bands. 

WItfi  the  coming  microcom* 
puter  explosion  in  amateur 
radio,  the  development  of 
packet  radio  transmissions. 
the  development  of  practical 
double  sideband  systems,  and 
a  host  of  other  exciting 
technical  developments.  It's 
obvious  that  technically  things 
have  never  looked  better. 

With  the  coming  Interna- 
tional Telecommunications 
Union  (ITU)  conference  at 
Geneva  next  October,  never 
have  things  looked  worse  for 
the  allocation  of  ham  bands,  I 
hope,  even  more  than  you,  that  I 
am  Just  a  worrywart  , , ,  and  it 
may  turn  out  that  my  worries 
are  needless. 

Having  been  one  of  the  of- 
ficial U.S.  delegates  to  the  1959 
ITU  conference  (the  last  full 
conference),  I  am  quite  aware 
of  the  pressures  on  amateur 
radio  allocations  at  that  time. 
We  held  our  frequencies  only 
because  of  a  miracle.  No  such 
miracle  seems  possible  next 
time. 

After  a  visit  to  20  countries  in 
Africa  and  Asia,  I  wrote  an 
editorial  in  73  outlining  what  I 
had  found.  That  was  In  1966, 
and  I  found  that  few  countries 
had  any  real  use  for  amateur 
radio  or  any  understanding  of 
the  value  of  the  hobby  to  their 
country.  Many  were  so  upset 
over  even  the  concept  of  third- 
party   traffic    that   they   were 


unable  to  evaluate  amateur 
radio  reasonably. 

After  talking  with  amateurs 
In  these  countries,  I  came  up 
with  a  proposal  that  amateur 
radio  societies  around  the 
world  try  to  encourage  emerg- 
ing nations  to  encourage  the 
use  of  amateur  radio  as  a  way 
to  develop  the  technicians  and 
engineers  so  badly  needed  in 
small  countries.  Nothing  what- 
ever came  of  this  until  Isold  His 
Majesty  King  Hussein  on  the 
concept  in  1970  and  he  im- 
plemented it  immediately. 

In  1971,  the  ARRL  went  to  the 
ITU  to  try  to  hold  on  to  our  ham 
satellite  frequency  allocations. 
There,  according  to  the  report 
in  OST,  they  found  that  the  ma- 
jority of  the  countries  of  the 
world  were  opposed  to  amateur 
radio  and  they  lost  every  ham 
satellite  microwave  allocation 
we  had  . . .  some  237,000  MHz 
of  them.  Down  the  tubes  went 
any  hope  for  worldwide  ham 
communications  via  satellite 
other  than  on  the  smallest 
scale. 

Once  it  became  clear  to  me 
that  there  was  no  way  that  I 
could  get  the  ARRL  or  lARU  to 
approach  the  countries  which 
would  In  all  probability  shoot 
down  our  allocations  at  WARC, 
I  tried  first  with  some  editorials 
in  73  to  encourage  business- 
men who  were  amateurs  to  car- 
ry the  ball.  Nothing  happened. 

The  only  hope  that  I  could 
see  left  was  to  get  a  group  of 
the  people  who  had  the  most  to 
lose  financially,  the  ham  in- 
dustry,  to  take  some  action. 
When  the  FCC  actions  on  linear 
amplifiers  got  so  ridiculous 
that  something  really  had  to  be 
done,  the  ham  manufacturers 
did  start  trying  to  form  an 
association.  They  tried  to 
cooperate  with  the  ARRL,  but 
found  themselves  undercut 
and  sabotaged  at  every  turn  by 


a  League  in  fear  of  any 
organization  other  than  the 
ARRL. 

Had  it  not  been  for  the  ARRL 
refusing  to  cooperate  with 
ARMA,  the  manufacturer's 
association,  we  might  not  have 
lost  the  linear  amplifier  battle 
with  the  FCC.  The  fact  was  that 
amateur  radio  put  on  a  disor- 
ganized response,  while  El  A 
had  its  act  together  and  clob- 
bered us.  A  large  part  of  the 
disorganization  was  directly 
due  to  the  League  counsel  and 
Its  weakening  of  the  ARMA  im- 
pact. The  ARRL  testimony  was 
one  of  the  most  inept  perfor* 
mances  I  have  ever  seen  and 
was  so  bad  the  FCC  Commis- 
sioners were  laughing  over  tt. 

Yes,  I've  been  an  ARRL  mem- 
ber for  over  40  years,  but  I  still 
get  annoyed  at  the  pitiful 
leadership  amateur  radio  has 
to  suffer.  The  "leaders''  are 
third-rate  bureaucrats  without 
a  hope  of  achieving  second 
rate.  They  are  protected  by  a 
group  of  directors  who,  for  the 
most  part,  are  afraid  to  offend 
the  bureaucrats. 

The  ARRL  likes  to  pose  as  a 
democracy,  but  they  are  much 
more  like  a  dictatorship.  Think 
about  It.  Members  don't  get  to 
vote  for  the  officers  at  all,  only 
the  directors  . . .  just  like  in 
Russia.  The  directors  (polit- 
buro)  vote  for  the  officers.  A 
dictatorship  is  a  one- party 
system,  just  like  the  ARRL  Why 
is  there  only  one  party? 
Because  the  dictatorship  de- 
stroys any  possible  chal- 
lengers. The  ARRL  has  had  a 
lonj  history  of  doing  whatever 
it  takes  to  keep  any  other 
organizations  from  gaining 
strength.  Their  latest  coups 
have  been  their  jobs  on  the 
QCWA  and  ARMA. 

How  did  they  get  at  ARMA? 

Continued  an  pag&  7 12 


?3Maga2fr>e  ispubNshed  FTX>nthly  by  73,  Inc.,  Peterijoromti  NH  03456  Sutjscription  rates  In  IhG  U.S.  and  Canada  are  Si 8  tor  one  year,  and  $36  tor 
tbree  years  Outside  theU.S  and  Canada,  write  tor  rales.  Second  cias^  fxist^^  paid  al  Petert?orDUQh  NH  03458 and  at  additional  mailing  offices. 
PubHcatl&n  No  7O(J420.  Phone.  603^924  3B73  Entire  cor^  tents  copy  riaht  19/6  by  73.  tnc  INCLUDE  OLD  ADDRESS  AND  2iP  CODE  WITH  AD- 
DRESS CHANGE  NOTIFICATION.  Microfilm  edlHon— University  Miciofilm,  Ann  Arbor  Ml  4flt06. 


When  the  MLA-2500  was  first  introduced  it  was  a  new  concept  in 
high  performance  amplifiers.    Low  and  sleek  yet  powerful  enough 
for  the  mnitary.   Some  wondered  ,  .  .  needlessly. 


A  promise  kept. 


The  IVILA-2500  promised  2000  watts  PEP  input  on  SSB-   A  heavy  duty 
power  supply.   Two  Ermac  8875's.   And  as  thousands  of  Amateurs  across 
the  world  have  proven,  the  M LA  2500  delivers! 

Now  DenTron  is  pleased  to  bring  you  The  new  MLA-2500  B- 
Inherently  the  same  as  the  original  MLA-2500,  the  B  model  includes  all 
of  the  above  specifications  plus  a  few  refinements.   New  high  low  power 
switching  for  consistent  efficiency  at  both  the  1 KW  and  2KW  power 
levels,  and  160  - 15  meters. 


Tested  and  proven. 


What  better  test  for  an  amplifier  than  the  Clipperton  DXpedition? 
Even  after  32,000  QSO's,  and  an  accidental  dunk  in  the  ocean,  the  same 
3  MLA  2500's  are  still  amplifying  other  rare  DXpeditions  around 

the  world  —  listen  for  them. 

Convinced?   Isn't  it  time  you  owned  the  amplifier  that  powered 
Clipperton  and  thousands  upon  thousands  of  radio  stations 
throughout  the  world? 

!VILA^2500B  $899.50- 


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Tw^^StKifQ  onto  44087 
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WINTER  '78/79  PRODUCT  LINE 


M 


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umMt 


AT-21 


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SP-520 


TS-520S  fi  DG-5 


he  AT-200  is  an  antenna 
tuner,  but  it's  also  much  more. 
It's  an  antenna  svvitch.  an 
SWR  bridge  and  an  in-tine 
wait  mater.  The  AT-200  re- 
duces the  dutter  and  increases 
the  operating  efficiency  of  your 


station      .  and  at  a  surprfsmgly 

moderate  price. 

The  SP-520  matching  speaker 

offers  improved  sound  m  a 

handsome  cabinei. 

The  DG-S   option  gives  you 

your  exact  frequency,  while 


transmitting  and  receiving,  in 
farge  easy  to  read  digits  by 
mixing  the  carrier,  VFO.  and 
heterodyne  frequencies. 
The  VF0-S2a  remote  VFO  is 
a  perfect  match  for  your  TS- 
520S  and  provides  maximum 


operating  flexibility. 
The  TV-502S  2-meter  trans- 
verter  produces  8  watts  on 
SSB  and  CW  It  easily  hooks 
up  to  the  TS  520  and  TS-820 
series  transceivers,  providing 
an  inexpensive  method  of  get- 


THE  TS-520S  SERIES  LITERALLY  TOOK  THE  AMATEUR  WORLD  BY  STORM.  NO  OTHER  RADIO  EVER 
CAUGHT  ON  SO  FAST  AND  THE  REASONS  ARE  OBVfOUS,.. EXCELLENT  PERFORMANCE 
CHARACTERISTICS,  DEPENDABILITY,  FLEXIBILITY,  AND  A  VERY  SOLID  VALUE  FOR  THE  PRICE.  AND 
NOW  THE  TS-520S  SERIES  OFFERS  THE  MOST  COMPLETE  LINE  OF  ACCESSORIES  AVAILABLE, 


FULL  COVERAGE  TRANSCEJVER 

The  TS-520S  providfis  full  cover- 
age on  afl  amateur  bands  from 
1.8  to  29.7  MHz  Kenwood  giv^s 
yoij  1  60  meter  capabiJity.  WWV 
on  15.000  MHz.,  and  an  auxil- 
iary band  position   And  with  the 
addrtion  of  the  TV-506  iransverter, 
your  TS-520S  can  cover  tSO 
meters  to  6  maters  on  SSB  and 

OUTSTANDING  RECEIVER 
SENSITIVITY  AND  MIMMUM 
CROSS  MODULATION 

The  TS-520S  incorporates  a 
3SK35  dual  gate  MOSFET  for 
outstanding  cross  modulation  and 
spurious  response  characteristjcs. 
The  3SK35  has  a  low  noise 
figure  (3,5  dB  typ.}  and  high  garn 
(18  dB  typ.)  for  excellent 
sensitivity, 

NEW  IMPROVED  SPEECH 
PROCESSOR 

An  audio  compression  amplifier 


gives  you  eictfa  punch  in  the  pile 
ups  afid  when  the  gotng  gets 
rough. 

VERNIER  TUNING  FOR  FINAL 
PLATE  CONTROL 

A  vernier  tuning  mechanism 
allows  easy  and  accurate  adjust- 
ment of  the  plate  control  during 
tune- up, 

FINAL  AMPLIFIER 

The  TS-620S  is  completely  solid 
state  except  for  the  driver  and  the 
final  lubes. 

Kenwood  has  employed  two 
husky  S-2001A  (equivalent  to 
6146B)  tubes.  These  rugged, 
time-proven  tubes  are  known  for 
their  long  life  and  superb  linearity, 

HIGHLY  EFFECTIVE  NOISE 
BLANKER 

An  effective  noise  blanking  cricuit 
developed  by  Kenwood  that  vir- 
tually elimifiates  ignition  noise  is 
built  into  the  TS-520S, 


RF  ATTENUATOR 

The  TS'S20S  has  a  butJt-in  20 
dS  atientuator  thai  can  be  acti- 
vated by  a  push  button  swfch 
convenienily  tocated  on  the 
front  panel. 

PROVISION  FOR 
EXTERNAL  RECEIVER 

A  special  jack  on  the  rear  panel 

of  the  TS'520S  provides  receiver 
Signals  to  an  external  receiver  for 
increased  station  versitility  A 
switch  on  the  rear  panel  deter- 
mines the  signal  path  ,  , .  the 
receiver  in  the  TS-B20  or  any 
external  receiver. 

CW-520-CW  FILTER  (OPTIONJ 

The  CW*520  B0O+<z  filter  can  be 
easitly  installed  and  will  provide 
improved  operation  on  CW, 

AMPLIFIED  TYPE  AGO  CIRCUIT 

The  AGC  circuit  has  three  posi- 
tions (OFF,  FAST  SLOW}  for 
optimum  operation  on  CW. 


AC  POWER  SUPPLY 

The  TS'520S  is  completely  self- 
contained  with  a  rugged  AC 
poMcr  supply  built-in  The  addi- 
tion of  the  DS!  A  DC'OC 
converter  (optional)  allows  for 
mobile  operation  of  fhe  TS-520S 

EASY  PHONE  PATCH  CONNECTIO 

TheTS-520S  has  two  convenient 
RCA  phono  jacks  on  the  rear 
pane^  for  PHONE  PATCH  IN  and 
PHONE  PATCH  OUT. 

The  TS-520S  retains  all  of  the 
features  of  the  original  TS-520 
that  made  it  tops  in  its  class:  RIT 
control  •  8-pole  crystal  filter  • 
Built-in  25  kHz  calrbrator*  Front 
panel  carrier  level  control  *  Semi- 
break-in  CW  with  sidetone  • 
VOX  /  PIT /M  OX  -TUNE  posaion 
for  low  power  tune  up  •  Built-in 
speaker  •  Built-in  cooling  fan  • 
Provisions  for  four  fixed  frequency 
channels  *  heater  switch. 


VF0-520S  TV-502S      TV-506 


SM-220 


ting  on  the  2'meter  band. 
The  TV-506  is  an  equally  prac- 
tiCaJ  way  of  getting  on  the  6- 
meter  band,  providing  10  watts 
on  SSB  and  CW. 
The  SM-220  is  an  extremely 
useful    and    unique   station 


monitor.  It  allows  you  to  moni- 
tor your  transmissions,  monitor 
incoming  signals  and  monitor 

the  amount  and  strength  of 
band  activity*  and  performs  as 
a  general  purpose  10  MHz 
oscilloscope,  as  well. 

"Wuh  BS-5  or  ESrE  pan  d^pH^f  OQttor^ 


r. , ,  hfurxnirr  »f  nmamtr  r 


w 


The  TS'820S  . , .  known  world  wide  as  the  Paca&etter.  Amateur 
Radio  Operators  urtiversalfy  mspect  its  superb  qualitv.  proven 
through  thousands  of  hours  of  operating  time  ynder  all  environ- 
mental  conditions.  The  TS  820S  has  every  feature  any  Amateur 
could  desire  for  operating  enjoyments  on  any  band  from  160 
through  a  IT  of  10  meters. 

You  can  always  tefl  who's  running  a  TS- 
820S-  Its  superb  quality  stands  out  from 
all  the  other  rigs  on  the  band  .  .  and  when 
the  QRM  gets  heavy,  the  TS-820S's 
adjustable  RF  speech  processor,  utilizing  a 
45  5-kHz  circuit  to  provide  quick-time- 
constant  compression,  will  get  the  message 
through.  RF  negative  feedback  is  applied 
from  the  final  to  the  driver  to  improve 
linearity,  and  third-order  products  are  at 
(east  —35  dB.  Harmonic  spurious  emis* 
sions  are  less  than  ^40  dB  and  other 
spurs  are  less  than  —60  dB.  RF  input 
power  IS  200  W  PEP  on  SSB.  1  60  W  DC 
on  CW,  and  100  W  DC  on  FSK.  Receiver 
sensitivity  is  better  than  0.25  /xV  for  10 
dB  S/N-  TheTS-820S  is  known  for  its 
superb  receiver  selectivity,  and  its  famous 
IF  shift  easily  eliminates  heavy  QRM. 
That's  why  the  TS  820S  is  the  DXer's 
choice. 

See  your  local  Authorized  Kenwood  Dealer 
today 


TkPe^CS 


SP-820      TS-820S 


VFO-820 


TV-506      SM-220 


•  * 


Muy  HuiilJmMOOO 

Kenwood  devetoped  the  T-599D  transmitter  and  R*6990 
receiver  for  the  most  discriminating  Amateur 

The  T-599D  transceiver  is  solid-state  with  the  exception 
of  only  three  tubes,  has  built-in  power  supply  and  full 
metering.  It  operates  CW,  LSB,  USB  and  AM  and,  of 
course,  is  a  perfect  match  to  the  R-599D  receiver. 

The  R-599D  is  the  most  complete  receiver  ever  offered.  It 
is  entirely  solid-state,  superbly  reliable  and  compact.  It 
covers  the  full  Amateur  band.  10  through  160  meters, 
CW,  LSB.  USB.  AM  and  FM. 


l^owi  itatZb^^  iMtt  cOiwpfetJL  ii  Itdm'iLt  uicM£,tftje,1?-820 


introducing  the  ultimate  in  receiver  design 
. . .  the  Kenwood  R-S20. 

Whh  more  features  than  ever  before  ava  ilabte 
in  a  ham-band  receiver,  This  tripleconversion 
(8.33  MHz,  455  kHz,  and  50  kHz  IFs)  receiver, 
covermg  alf  Amateur  bands  from  1 60  through 
10  meters,  as  well  as  several  shortwave 
broadcast  bands,  features  digital  as  well  as 
analog  frequency  readouts,  notch  filter,  IF 
shift,  variable  bandwidth  tuning,  sharp  IF 
filteiTS,  noise  blanker,  stepped  RF  attenuator, 
25  kHz  calibrator,  and  many  other  features, 
providing  more  operating  conveniences  than 
any  other  ham-band  receiver.  The  R-820 
may  be  used  in  conjunction  with  the  Ken- 
wood TS-820  series  transceiver,  providing 
futl  transceive  frequency  control. 


Additional  features  include  A  monitor  switch 
which  aUows  the  user  to  hear  his  own  voice 
when  using  associated  transmitter.  Either  VFO 
control  or  crystal  control  on  four  selectable 
frequencies  Digital  hold  . , ,  locks  counter  and 
display  whtle  VFO  is  tuned  to  another  fre- 
quency ...  faciMtates  return  to  *'hold"  fre- 
quency. RIT/ notch  control .  .  .  RIT  allows 
receiver  to  be  tuned  off  frequency,  while  not 
affecting  transmit  frequency  when  in  trans- 
ceive mode  with  TS-820S,  Notch  control 
tunes  notch  within  IF  passband  for  elimina- 
ting interference,  Interfering  signal  remains 
notched  even  when  IF  shift  is  utilized.  Built-in 
crystal  calibrator,  settabfe  to  WWV  provides 
signal  every  25  kHz.  Noise  blanker/level 
control . . .  for  maximum  reduction  of  noise 
interference.  A  transceive/separate  switch 
enables  receive  VFO  to  control  the  receiver 
and  TS-820  (or  TS-820S)  frequency  (or  the 
TS-820  VFO  to  control  both),  or,  of  course, 
both  can  Function  independently 


IktiAmtvmdMt  pcuk  (HLtfct  ot/L 


you  have  never  considered  the  advantages  of  operating 
a  receiver/ transnnitter  combination  .  . .  maybe  you  should. 
Because  of  the  larger  number  of  controls  and  dual  VFOs 
the  combination  offers  flexibility  impossible  to  duplicate 
with  a  transceiver. 

Compare  the  specs  of  the  R-5  99D  and  the  T-599D  with 
any  other  brand.  Remember,  the  R-599D  is  aH  solid-state 
(and  includes  four  filters).  Your  choice  wifl  obviously  be 
the  Kenwood. 


#  #  ■ 


1 


^  KErMWOOD       oah/i«MJ>^iE3MTii:3Nn      miECEiweta     imciuc:i^  *h  -Monts 


10  WATT 


. . .  KENWOOD 
OFFERS  A 
CHOICE 


•  Full  4'MHz  coverage  (144.000-147.995  MHzJ 
on  2  meters  •  800  channels  •  Dual  concentric 
knobs  for  fast  frequency  change  (lOO-feHz  and 
lO-kHz  steps)  •  5-kHz  offset  switch  •  MHz 
selector  switch  .for  desired  band  (144,  145* 
146.  or  147  MHz)  •  Mode  switch  for  operating 
simplex  or  for  switching  the  transmit 


frequency  up  or  down  800  kHz  for  repeater 
operation , .  or  for  switching  the  transmitter 
to  the  frequency  you  have  stored  in  the 
TR-7600's  memory  (while  the  receiver  remains 
on  the  frequency  you  have  selected  with  the 
dual  kJiobs)  •  Memory  channel,    wtth 
simplex  or  repeater  (plus  or  minus  GOO  kHz 
transmitter  offset)  operation  ■  Dtgital 
frequency  display  (large,  bright,  orange  LEDsJ 
■  UfslLOCK  indicator     an  LEO  that  indicates 
Iranscetvef  protection  when  the  frequency 
sefector  switches  are  improperly  positioned, 
or  the  PLL  has  malfunctioned  •  tO  watts  RF 


ouiput  (swltchable  to  1  watt  low  power) 

•  Noise-cancellir^g  microphone  •  Compact 
SFze  (on^y  6-7n6  inches  wide,  Z'7^16  mches 
high,  and  9*3/16  inches  deep) 

The  RM-76  Microprocessor  Control 

Unit  provides  more  operating 
features  to  the  TR-7600  2'metef  FM 
tranceiver  than  found  in  any  other  rlgf 
Wtth  the  AM -76  Microprocessor  Control  Unit 
attacheif  to  your  TR-7eOG,  you  can... 

•  Select  any  2-metef  frequency  •  Store 
frequencies  in  six  memories  ■  Scan  af^  memory 
channels  •  Automaticatly  scan  up  all 
frequencies  in  5-kHz  steps  «  Manyatly  scan  up 
or  down  \n  5-kHz  steps  •  Set  lower  and  upper 
scan  frequency  timits  •  Reset  scan  to  144  MHz 

•  Stop  scan  (with  HOLD  button)  •  Cancel  scan 
(for  transmittmg)  •  Automatically  stop  scan 
on  fifs!  busy  or  open  channel  >  Operate  on 
MARS  (143  JS  MHz  simplex  only)  *  Select 
repeater  mode  (simplex,  plus  transmit 
frequency  offset,  minus  offset,  or  any  of  six 
memory  transmit  offsets)  •  Select  transrt^it 
offset  (1  MHz/600  kHz} 

The  Micfopfocessor  Control  tlntt's  display 
Indicates  frequency  (even  while  scanning)  and 
functions  (such  as  autoscan,  lower  scan 
frequency  IFmitt  upper  scan  limit,  error, 
dftd  call  channel)* 

Subject  to  FCC  approvpij 


SP-70     VF0-700S 


StUf  th©  sama  fine,  time  proven  rig.  But  now  with 
the  simple  addition  of  a  plug-in  crystalp  the 
TS'7Q0SP  will  be  able  to  utilize  the  new  repeater 
3ut)"band  (144.5  to  145,5  MHz).  Still  features  all  of 
the  fine  attributes  of  the  TS-700S:  A  digital 
frequency  display*  receiver  pre-amp,  VOX,  semi- 
break  in,  and  CW  sidetone.  Of  courser  it's  all  mode. 
144-148  MHz,  VFO  controlled  ,  ,  .  and  Kenwood 
quality  throughout. 


Features:  4  MHz  band  coverage 
(144  to  148  MHz)  •  Automatic 
repeater  offset  capabrlity  on  all  FCC 
authorized  repeater  subbands 
including  144.5-145.5  MHz  • 
Simply  dtai  receive  frequency  and 
radio  does  the  rest .  .  .  simplex,  re- 
peater, or  reverse.  Same  features 
on  any  of  11  crystal  positions  ■ 
Transmit /Receive  capability  an  44 
channels  with  1 1  crystals  •  Oper- 
ates alf  modes:  SS6  {upper  and 


towerK  PM,  AM  and  CW  •  Digital 
readout  with  "Kenwood  Blue  ' 
digits  *  Receiver  pre-amp  •  Built-in 
VOX  •  Semi  break-in  on  CW  •  CW 
sidetone  •  Ail  solid-state  •  AC  and 
DC  capability  10  watts  RF  ouiput 
on  SSB,  FM,  CW  •  3  watts  on  AM 
»  1  watt  FM  low-power  switch  • 
0.25  /iV  for  10  dB  (S+N)/N  SSB/ 
CW  sensitivity  -  0.4  juV  for  20  dB 
quieting  FIVl  sensitivity, 


br2 5  WATT  OUTPUT 


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KEMIATOOO 


am    o*f 


2m  Fil  TRANSCEIVER 


Mrf  i 


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3   ±   J: 


too  KHl 


10  kHz 


TX  OFFSET 


H*        -P  tOL 


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T«-7aOQA 


The  fuily-synfhasized  TR-7400A  2 -meter 
FM  transceiver  operates  on  800  channels 
and  features  repeater  offset  over  the 
entire  144-14&-MHz  range,  dual  fre- 
quency readout,  six-digit  dfsplay,  and 
subaudible  tone  encoder  and  decoder. 
RF  output  is  at  least  25  waits! 


The  TR-7400A  2-nneter  FM  traoscerver 

provides  fully  synthesi2ed  operation, 
includtng  BOO-kHz  repeater  offsets, 
over  the  entire  144'T48-MHz  range,  ft 
can  operate  on  any  of  800  channels, 
spaced  5  kHz  apart.  RF  output  is  at 
least  25  W,  and  typrcally  30  W,  A  lov^^ 
power  position  produces  5-1  5  W  (ad- 
justable). Included  is  a  dual  frequency 
readout  with  large  six-dtgit  LED  dis- 
play plus  a  dial  readout,  The  sub- 


audibfe  CTCSS  stgnalmg  feature  may 
be  used  on  transmit  and  receive,  or 
transmit  only.  Optional  tone-burst 
modules  are  available.  Receiver  sen- 
SHivity  IS  better  than  0  4  ^V  for  20 
dB  quieting.  Large,  high  Q.  hehcal 
resonators  minin^ize  interference  frorn 
outside  the  band.  A  two-pole  10.7- 
MHz  monolithic  crystal  filter  provides 
excellent  selectivity,  Intermodulation 
distortion  is  down  more  than  66  dB. 
spurious  rejection  is  better  than  —60 
dB,  and  image  rejection  is  better 
than  —70  dB. 

See  your  local  Authorized  Kenwood 
Dealer  today,  for  a  demonstration  of 
the  fantastic  TR-7400A. 


Expenence  the  excitement  of  6 
meters.  The  TS'600  afl  mode 
transceiver  lets  you  experience 
the  fun  of  6  meter  band  openings 
This  10  watt,  solid  state  rig  cov* 
ers  50  0-54.0  fVlHz.  The  VFO 
tunes  the  band  in  1  MHz  seg- 
ments, h  also  has  provisions  for 


fixed  frequency  operation  on 
NETS  or  to  listen  for  beacons. 
State  of  the  art  features  such  as 
an  effective  noise  blanker  and  the 
RIT  (Receiver  Incremental  Tun* 
tng)  circuit  make  the  TS-600 
another  Kenwood  '  Pacesener  * 

TRIO  KEfy WOOD  COMMUNICATrONS  IhfC, 
1111  WEST  WALNUT/ COM PTON.  CALIFORNIA 


K,pan\S4iter  hi  amaleur  radiu 


WtTB^ 


EJ#*E*« 


TIK-^ 


-'Qir^AATE 


j^jjME^^^A   ^iv**^n_rPieR 


GuAt  OfW/L  A^Jtoi  e0JL^lMJU6clk 


The  Kenwood  name  has  grown  to  represent  the  finest  Ama- 
teur Radio  equipmeni  available.  The  TL-922A  linear  amplifier 
carries  on  that  tradition.  As  a  linear  it  gets  your  signal  through 
today's  crowded  bands  and  provides  the  power  to  reach  those 
far  away  places  with  ease.  And  because  it's  Kenwood  you 
can  count  on  its  dependability.  The  TL922A  is  FCC  type  ac- 
cepted. It  runs  the  full  legal  limit  on  all  ham  bands  from 
160-15  meters  and  is  compatible  with  most  amateur  exciters. 
Contact  your  nearest  Authorized  Kenwood  Dealer  for  com- 
plete specifications  and  the  best  deal, 


WHY  SHOULD  THE  TL  922A 
BE  PART  OF  YOUR 
STATION?  COMPARE 

THESE  FEATURES  AND 

SPECS THE  ANSWER 

WHL  BE  OBVIOUS, 
Instant  healing  filaments  — 
The  3-60DZ  tubes  require  no 
warm  yp  period.  Just  turn  it 
on  and  go! 

Time  dolay  fen  crrcuh  —  Even 
after  you  turn  the  TL922A  off, 
the  super  quiet  fan  continues 
to  work  for  approximately  2 
minutes  to  greatly  extend  tube 

IJfB. 

Adjustable  ALC  output  volt- 
age —  Lais  you  taitor  the  ALC 
voltage  to  your  exciter. 
Stdfidbv  position  —  Provides 
amplifier  bypassing  without 
having  to  turn  the  AC  power 
off. 

Two  independent  safety  in- 
terlocks  —  One  disconnects 


AC  line  voltage  and  the  second 
shofts  8+  to  ground  when 
tripped. 

Vernter  plate  control  —  For 
smooth  easy  tune-up. 
Diecast  side  panels — Inctudes 
functional  carrying  handles  tor 
easy  transportation. 
Thermal  protection  of  power 
transformer —  Amplifier  auto- 
matically switches  to  standby 
if  power  transformer  tempera- 
ture exceeds  MB^'F. 
Tuned  Input  Circuit  —  Means 
improved  spurious  character- 
istics. 

Line  voltage  selector  —  Easily 
switched  between  120  and 
240  VAC. 

Multimeter  —  Reads  high  vol- 
tagsi  relative  output  or  grid 
current  (selectable), 
Plate  Current  Meter  —  Separ- 
ate meter  allows  continuous 
monitoring  of  plate  current. 


Dependable  operation,  superior  specifications  and  excellent 
features  nnake  the  R-300  an  unexcelled  value  for  the  short- 
wave listener.  It  offers  full  band  coverage  with  a  frequency 
range  of  170  kHz  lo  30.0  MHz  •  Receives  AM,  SSB  and  CW 
•  Features  large,  easy  to  read  drum  dials  with  fast  smooth 
dial  action  *  Band  spread  is  calibrated  for  the  10  foreign 
broadcast  bands,  easily  tuned  with  the  use  of  a  butk-in  500 
kHz  calibrator  •  Automatic  noise  timiter  •  3'way  power  sup- 
ply system  (AC/ Batteries/ EKternal  DC) . . .  take  it  anyplace  ■ 
Automatically  switches  to  battery  power  in  the  event  of  AC 
power  failure. 


\v*» 

\ 

^^1  ji_UiSjio*M- •_- - 

B 

1 

■ 

1, 
1' 

How  would  you  like  to  work  an  uncrowded  frequency . . .  hear  signals  with  fess 
noise . ,  .or  use  a  sophisticated  repeater  or  remote  base  with  better  coverage? 
440  MHz  is  the  answer.  It  will  surprise  you.  It  wHI  penetrate  buildings  where  2 
meters  won't,  and  often  you  can  even  work  out  from  underground  garages , . . 
where  2  meters  is  dead. 

Best  of  alL  it's  easy  to  get  on  440  MHz  (70  cm) . . .  with  a  Kenwood  TR-8300 
transceiver.  High  quality  is  critically  important  on  VHF  bands,  and  the  TR-8300  is 
just  what  you  need  to  meet  afl  technical  requirements. 

■ 


•  10  watts  RF  output  (switchable  to  1  watt) 
'23  crystal-controlled  channels  {3  supplied) 

445. 0-4 50.0  MHz  transmit  range 

•  442,0-447.0  MHz  receive  range 

•  Transmitter  and  receiver  adjustable  over  any 
5-MHz  segment  from  440  to  450  MHz 

•  5-sect(on  helical  resonator  and  2-pole  crystal 
filter  m  IF  to  reject  intermod 

SWR  protection  in  final  amplifier 

■  Excessive-voltage  ana  reverse-polarity 
protection  circuits 

•  0,5  jLtV  for  20  dB  quieting  sensitivity 

•  Better  than  ^60  dB  spurious  radiation 

•  20  kHi  (-6  d8),  40  kHz  {-70  dB}  selectivity 

•  Monitor  switch  that  lets  you  check  modulation 
and  frequency  'neltmg' 

•  Call  CH  switch  that  activates  optional  CTCSS 
(subaudible  tone)  function 

■  Large  S  meter 

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TRIO-KENWOOD  COMMUNICATIONS  INC. 
1111  WEST  WALNUT/  COMPTON,  CA  90220 


'"  troji  r 


^^  'J 


QUASf  PRIMA  DONNA 

OncBt  as  an  untutored,  not- 
yet-jaded  youth  of  15J  had  the 
temerity  to  write  the  editor  of 
OSr  suggesting  that  the  ARRL 
lend  *'Gil"  to  the  Government  of 
India,  where  his  wretched  iV\ 
yo-yos  doing  all  the  li'i  no-nos 
could  be  used  to  far  greater  ad- 
¥anta9e  on  birth  control  prop- 
aganda posters. 

The  resulting  correspon- 
dence has  been  long  mis- 
placed, but  be  assured,  alt  hell 
broke  loose;  as  1  saw  it  in  1965, 
anyway. 

Now  I  freely  confess  to  being 
a  nostalgia  freak  and,  In  hind- 
sight, some  "Gil"  illustrations 
are  their  own  reward.  It  was  in 
September  of  this  year,  how- 
ever, that  I  found  that  the  gates 
of  hell  can  still  t>e  flung  open  on 
command,  and  while  they 
couldn't  really  do  much  to  a  kid 
of  15.  it  will  really  amaze  you 
what  can  be  done  to  a  married, 
professional  fellow  of  33. 

Right  now,  you're  probably 
wondering  what  this  has  to  do 
with  the  pr^ce  of  opium  in 
Macao.  Stay  with  me  and  I  shall 
enlighten  you. 

When  Wayne  Green  was  the 
editor  of  CQ I  thought  It  was  the 
neatest  and  funniest  magazine 
in  the  world,  (I  was  a  very  ar- 
cane kid.)  After  joining  the 
Navy  in  1957,  suff Bring  through 
ET  school  at  Treasure  Island  {in 
the  winter),  and  being  assigned 
to  the  fleet,  I  looked  forward  to 
my  COs  B'^ery  b\l  as  much  as 
letters  from  my  steamy  girl 
friend.  Now  I  realize  this 
sounds  bizarre  on  the  face  of  it, 
but  if  you  are  fortunate  enough 
to  know  an  old-time  ham  with  a 
storeroom  full  of  old  radio 
magazines,  be  prepared  to  see 
some  ham  cartoons  worthy  of 
the  name,  it's  been  years  since 
a  sample  of  this  genre  has 
brought  much  more  than  a 
"yeechh"  out  of  me-  It  also 
goes  without  saying  that  his 
**jack-em-up"  editorials  were 
about  the  same,  bot  somehow 
not  so  pessimistic,  and  far 
more  entertaining.  But  we  all 
march  to  the  clock  and  that, 
really,  is  the  whole  point  of 
what  Tm  trying  to  get  to. 

How  emotional  have  I  got- 
ten? Well,  Tve  gotlen  so  emo- 
tional that  I  shot  off  a  hot 
telegram  to  Mr.  Richard  Bald* 
win  W1RU,  using  not  one  of  the 
seven  dirty  words,  but  express- 


S\\ft     i^hOu 


ing  my  feeling  strongly. 

Please  be  advised  that  such 
a  course  is  not  tor  the  faint- 
hearted, but  the  only  fair  com- 
parison between  me  and  the 
late  Arnold  Stang  is  glasses. 

To  get  Mr,  Baldwin's  atten- 
tion (Le.,  to  let  him  know  I  did 
not  survive  by  scouring  alleys 
for  unbroken  pop  bottles),  I 
mentioned  my  company*s 
name  and  the  position  1  oc- 
cupy. This  was  a  mistake 
— whether  mine  or  his  is  not  yet 
clear. 

I  am  not  a  member  of  the 
ARRL  anymore,  which  is 
wrong,  I  suppose,  because  it 
puts  me  somewhat  In  the  posi* 
tlon  of  a  rock  thrower- 

The  reason  I'm  not  is  simply 
because  the  itiusion  of  a  retard- 
ed bear  cub  swatting  incom- 
petently at  a  newty  found  ap- 
pendage is  quite  torturous. 
Allow  me  to  digress- 

I  am  employed  by  a  hallowed, 
old'line  radio  company 
(okay— the  first  3  letters  of 
which  is  the  same  as  hallowed, 
and  deservedly;  that's  as  far  as 
I  go)  that  receives  gratis  copies 
of  all  the  ham  and  related 
monthlfes. 

To  thine  own  self  be  true,  I 
read  these  on  breaks  and  at 
lunch— 1  guess  I'll  never  grow 
up—and  have  become  some- 
what emotional  about  WARC 
'79. 

I  wanted  to  get  his  attention 
to  possibly  start  a  dialogue  or, 
more  to  the  point,  to  do  his 
damn  job  instead  of  being 
some  sort  of  quasi  prima  donna 
fiddling  while  our  frequencies 
burn. 

What  happened  was  totally 
unexpected.  The  League  Pooh- 
bah  is  not  a  Pooh-Bear,  he  is  a 
Nixonian  treasure,  and  I  now 
have  the  questionable  distinc- 
tion of  being  on  Richard's 
enemies  list,  with  a  vengeance, 

A.  On  Saturday,  September 
16,  I  got  a  personaily-dictated 
fetter  from  W1RU  telling  me  he 
"does  not  respond  to  corre- 
spondence personally  calling 
him  a  son  of  a  bitch"— which 
was  not  really  true.  Hang  on. 
The  telegram  will  be  printed, 
regardless  of  the  accuracy  or 
inaccuracy  of  the  statement.  (I 
know  the  concept  here  is  tor* 
turous.)  This  was  the  first  non- 
response. 

B,  I  was  greeted  at  noon,  on 
Monday.  September  18,  with  a 
Xerox  copy  of  a  letter  guaran- 
teed to  catch   fire  when   ex- 


posed to  light,  written  by  W1 RU 
to  the  President  of  my  com- 
pany, the  text  of  which  I  cannot 
relate  verbatim,  presented  by 
my  boss, 

W1RU  pulled  out  a//  the 
stops  to  get  me  fired  in  the 
sleaziest,  mosi  innuendo-peP' 
pered  misuse  of  personal 
power  I  have  ever  had  the  mis- 
fortune to  read.  The  very  inac- 
curacy  and  overkill  of  the  at- 
tempt, in  our  times  of  universal 
free-ha-ha,  literally  saved  me,  I 
am  truly  fortunate  to  work  for 
some  fine,  decent  human  be- 
ings. This  was  the  second  non- 
response* 

I  guess  this  is  where  I  should 
say  that,  gee,  it's  only  a  hobby, 
folks.  But  it's  much  more  than 
that  VvB  been  caught  up  in  the 
mystique  and  adventure  of  ham 
radio  like  few  others.  I  per- 
sonally feel  that  the  Arabian 
nights  I  have  spent  over  the 
warm  smell  of  communications 
equipment,  listening  to  and 
talking  with  people  the  world 
over,  and  looking  out  of  my  win- 
dow at  the  starry  early-morning 
sky,  have  shaped  my  personali- 
ty. I  truly  don't  know  what  \ 
would  have  done  in  the  1800s— 
my  greatgreat  uncle  was  a 
renowned  gunflghter  (Will 
Stokes),  but  I  donl  think  that 
would  have  been  my  calling. 
It*s  just  lucky  to  be  here  today, 
with  the  apparatus  existent  to 
fly  your  fancies  according  to 
your  innermost,  gut-wrenching 
needs. 

Now,  to  that  telegram.  Being 
worked  up  over  losing  all  this  to 
a  bunch  of  people  who  don't 
even  have  the  wherewithal  to 
utilize  it,  I  said: 

If  Wayne  Green's  September 
editorial  Is  even  10%  correct,  you 
SOBs  should  be  dismembered  and 
thrown  to  a  ^ack  of  wild  dogs. 

Terry  Siaudt  wewuz 
Company  Tliie 

This  is  a  good  old  Colorado 
saying  used  sparingly  to  ex- 
press true  disgust.  There  is 
also  some  humor  there  that 
evidently  loses  itself  when  put 
in  print,  especially  to  plastic 
people  of  the  job  set. 

I  sincerely  hope,  as  does  Lew 
McCoy,  Wayne,  and  Johnny 
Johnson,  that  the  ARRL  gets  Its 
act  together  in  time  to  properly 
present  our  incomparably-just 
cause. 

Terry  Staudt  WiWUZ 
Ft.  Worth  TX 


TAKE  A  LICKING? 


Many  of  my  friends  are 
"wheels'^  in  CCIR,  URSL  IEEE, 
etc.  Just  two  weeks  ago  there 
was  an  international  meeting 
of  URSI  {IntI  Sci  Radio  Union)  in 
Helsinki.  One  of  my  old  college 
buddies  Is  a  commission  charr* 
man  (in  charge  of  matters  re- 
lating to  radio  noise,  man-made 
and  natural).  He  told  me,  In 


passing,  that  he's  afraid  the 
hams  are  going  to  take  a  licking 
at  WARC— something  similar 
to  what  Wayne  has  been 
writing  about.  This  friend  of 
mine  had  recently  talked  to 
Dick  Kirby.  In  fact,  he  had  put 
together  a  panel  wherein  Kirby 
and  several  other  spectrum 
managers  talked.  Also,  my 
friend  last  year  edited  an  entire 
IEEE  volume  on  spectrum  man- 
agement,  including  articles  on 
WARC, 

Well,  I  happened  to  tele- 
phone the  ARRL  the  next  day 
and  asked  to  speak  to  the  guy 
in  charge  of  WARC  relations.  It 
turned  out  to  be  Bruce  John- 
son, whom  I  don't  know.  Any- 
way, Johnson  assured  me 
that  my  friend  (who's  worked  as 
a  radio  engineer  for  Stanford 
Research  Institute  for  20  years 
. . .  and  has  had  very  close  con- 
tact with  CCIR,  etc.)  is  aft 
wrong. 

Aiso^  Johnson  had  never 
heard  of  URSI!  He  wasn't  sure 
he'd  heard  of  the  IEEE  Spec- 
trum Management  group.  The 
ARRL  had  turned  down  Stan- 
ford  Research  Institute's  pro- 
posal to  do  a  study  for  the 
ARRL  which  could  also  be  used 
by  third-world  countries  to  sup- 
port ham  needs  in  the  HF  and 
VHP  spectra. 

Johnson  was  also  sure  that 
anything  that  goes  on  at  inter- 
national meetings  such  as 
URSI  can't  affect  WARC  since 
alt  countries  have  already 
decided  on  their  plans,  (This  is 
8.S.,  since  many  third-world 
countries  are  in  limbo*) 

in  any  case,  the  message  I 
got  was  that  the  ARRL  is  all  set. 
They  know  all  that's  worth 
knowing,  and  guys  like  me,  who 
worked  for  the  National  Bureau 
of  Standards  CRPL  back  when 
Johnson  was  in  grammar 
school,  are  to  l>e  tolerated  but 
not  listened  to. 

By  the  way.  W1 FYM  just  told 
me  that  Bruce  Johnson  had 
promised  to  join  us  for  our  1978 
Field  Day  QRP-computerized 
operation.  Two  days  before 
Field  Day,  Wl  FYM  asked  about 
Johnson  and  somebody  at  the 
ARRL  told  him,  "Oh,  Johnson's 
not  going  with  you  guys.  He 
had  the  chance  to  go  to  Penn- 
sylvania and  work  Field  Day 
with  some  real  big  shots.,," 
Johnson  didn't  even  bother  to 
tell  us. 

Plus  ca  change. . . 

C.  Stewart  GlllmorWtFK 
Higganum  CT 


[ 


SRRL? 


ril  preface  the  foltowing  with 
the  fact  that  I  have  been  a 
member  of  the  ARRL  for  most 
of  my  22+  years  as  a  ham. 
Have  you  heard  about  the 
latest  attempt  to  set  up  a  dic- 
tatorship by  the  Board  of  DIrec- 


14 


tors  of  the  League?  It  was  bad 
enough  when  they  stripped 
Mary  W7QG  P  of  the  right  to  run 
as  Washington  SGM.  Now  they 
have  taken  on  the  entire 
League  membership  of  the 
Northwestern  Division:  Alaska, 
Idaho,  Montana,  Oregon,  and 
Washington, 

In  case  you  did  not  hear 
about  the  latest  news  from 
Newington,  here  goes:  Mary 
was  to  run  against  the  incum- 
bent, Bob  Thurston  W7PGY,  for 
Director.  It  seems  that  the  Ex- 
ecutive Comnnlttee  decided 
against  allowing  the  members 
of  the  Division  to  democratical' 
ly  decide  who  is  the  better  can- 
didate. Instead,  they  *'post- 
poned"  the  election  and  gave 
W7PGY  the  position  until  after 
the  election  is  "decided."  The 
election  has  been  postponed 
until  the  current  litigation  be- 
tween Mary  and  the  League  is 
completed.  If  that  litigation 
takes  another  two  years,  then 
Bob  Thurston  will  have  been 
the  appointed  Director  for  his 
entire  term  of  office! 

1  wrote  to  Dick  Baldwin,  but 
do  not  expect  any  answer,  un- 
less It  Is  a  form  letter.  I  will  not 
resign  from  the  ARRL,  as  they 
may  not  be  doing  much,  but  a 
little  is  better  than  nothing  with 
WARD  coming  up  next  year. 
Anyway,  to  paraphrase  the  let- 
ter to  W1RU,  "Welcome  to  the 
Soviet  Radio  Relay  League!" 

Keep  up  the  fight.  We  need 
some  voices  In  the  wilderness 
agafnst  the  fuddy-duddies  in 
Newington,  and  you  do  a  better 
job  than  Cowan  does  in  CQ.  Oh 
yes,  Wayne.  ^'Looking  West"  is 
a  good  column,  but  contrary  to 
what  Californians  believe, 
there  is  a  lot  more  to  the  west 
coast  than  6  Land! 

Jerry  Ostrer  W7EMX 
Vancouver  WA 


ROSE-COLORED  GLASSES 

1  Just  finished  reading  a  letter 
to  you  from  Carl  Manion 
W4BDC  in  the  September,  1978, 
fssue  of  73.  In  his  letter;  Mr, 
Manion  was  highly  critical  of 
your  stand  against  some  ARRL 
policies,  and  of  similar  policies 
of  the  other  ham  magazines. 

I  have  been  reading  all  of  the 
"big  four*'  ham  rags  (except 
CQ)  now  for  twenty  years,  or 
since  the  first  issue  of  each 
respective  magazine,  and  I 
want  you  to  know  that  this  Ken- 
tuckian  totally  agrees  with  your 
opinions  and  especially  with 
your  right  to  express  them. 
Perhaps  the  reason  QST,  et  al, 
remains  silent  in  respect  to 
Wayne  Green  and  73  is  the  old 
"let's  ignore  him  and  maybe 
hell  go  away"  theory.  Or  then, 
again,  maybe  it's  because  they 
know  they  have  no  defense 
against  the  truth. 

I  applaud  you  and  your  staff 


for  being  the  leader  in  ham 
magazines.  There's  no  doubt 
about  It  ...  75  is  way  out  in 
front.  Please  don't  stop  keep- 
ing  us  informed  of  the  trutti, 
even  when  it  sometimes  hurts. 
In  closing,  let  me  say  that  I 
am  sure  that  for  each  renewal 
you  don't  receive  from  people 
in  Mr.  Manion's  league,  you  wili 
get  three  or  four  from  those 
who  welcome  the  truth  and 
donM  see  ham  radio  as  a 
wonderful  hobby  through  a  pair 
of  rose-colored  glasses. 

Michael  W.  Babb  N4PF 
Louisville  KY 


EMEMLES  NOT  NEEDED 

Jam  10  GHz  police  radar?  If 
we  lose  this  band,  you  will 
receive  a  bill  for  my  two  Gunn- 
plexers.  With  friends  like  you, 
amateur  radio  doesn't  need 
enemies.  Just  because  some- 
one writes  an  article  doesn't 
mean  you  have  to  print  it, 

Steve  Noll  WA6EJ0 
Ventura  CA 


REALLY  WEIRD 

This  reader  has  held  a  Class 
A  (Advanced  class)  ticket  since 
June  of  1939  and  therefore 
qualifies  as  something  of  an 
old-timer. 

You  are  correct  in  that  the 
ARRL  has  made  some  mis- 
takes. The  first  was  in  not  bat- 
tling the  FCC  (if  necessary)  to 
the  end  when  the  Ctass  A  sub- 
bands  were  opened  to  all 
General  class  tickets.  This 
problem  was  remedied  when 
'Mncentive"  licensing  was 
restored,  even  though  this  ham 
lost  some  privHeges  until  this 
year  when  he  f i  nally  went  up  for 
Extra  class  and  upgraded.  The 
other  mistake  was  in  not  doing 
everything  to  prevent  amateur 
licenses  which  omitted  the  13 
wpm  code  test. 

There  are  certainly  many  ex- 
cellent technical  men  with 
Technician  class  licenses,  but 
that  is  not  the  point.  The  reader 
whose  letter  appeared  in  your 
Letters  column  a  few  issues 
ago  stating  that  the  code  bands 
will  eventually  be  opened  wide 
to  phone  simply  is  too  much  of 
a  ''young  squirt''  to  know  the 
score.  No  matter  how  much  ad- 
vancement is  made  in  the  art, 
as  the  number  of  hams  in- 
crease and,  hence,  increase  the 
QRM,  the  ham  bands  will  even- 
tually become  like  the  CB  chan- 
nels are  today,  That  is  the  day 
this  ham  will  tear  up  his 
license.  Even  the  opening  of  all 
CW  subbands  would  not  pre- 
vent this.  Developing  13  wpm  or 
more  in  CW  is  not  that  difficult, 
and,  once  a  ham  reaches  it, 
most  enjoy  CW  contacts  im- 
mensely. When  the  QRM  be- 


comes completely  unbearable 
at  some  time  in  the  future,  the 
logical  move  would  be  to  nar- 
row down  the  phone  bands  and 
increase  the  CW  spectrum 
such  as  we  had  when  the  entire 
40  meter  band  was  CW  only.  In 
this  way,  ham  radio  will  con- 
tinue successfully— especially 
with  the  terrific  new  CW  filters 
on  the  market, 

Wayne,  despite  the  mistakes 
of  the  ARRL,  some  of  your 
counter-proposals  are  really 
weird  J  Not  all,  but  some.  Lay 
off  the  ARRL,  but  continue  your 
suggestions,  if  you  desire. 

John  B.  Broughton  AD4I 
Charleston  SO 


SEMANTICS 

The  recent  article,  "New  Life 
for  Double  Sideband?'*,  de- 
serves some  comment.  This  ar- 
ticle was  in  the  August,  1978, 
issue  of  73. 

First  of  all,  the  author  is 
engaging  in  semantic  exer- 
cises when  he  says  that  the  car- 
rier of  an  AM  signal  is  not 
changed  by  the  modulating 
process.  It  is  true,  of  course, 
that  mathematical  analysts 
and  a  spectrum  analyzer  will 
show  that  the  carrier  is  un- 
changed when  modulation  oc- 
curs. Nevertheless,  examina- 
tion of  the  modulated  wave  on 
an  oscilloscope  clearly  shows 
that  the  amplitude  of  the  out- 
put wave  does  vary  with  the 
audio  input.  Whether  or  not  you 
call  that  the  carrier  or  not  is  up 
to  the  reader,  but  amplitude 
variation  of  the  output  certainly 
does  occur.  Similarly^  in  FM, 
the  frequency  of  the  output 
wave  certainly  varies,  white  the 
actual  carrier  frequency  itself 
remains  constant,  and  varies  m 
amplitude.  Again,  the  whole 
thing  depends  upon  the  defini- 
tion of  certain  terms.  In  my 
view,  the  original  1976  article 
by  KllOon  this  subject  created 
more  confusion  than  it  cleared 
up. 

Similar  semantic  problems 
occur  in  the  author's  discus- 
sion about  the  detection  of 
DSB.  Most  authors  of  texts  in 
communications  theory  use 
the  terms  ''synchronous,  prod- 
uct, and  coherent"  to  mean  the 
same  thing  in  describing  detec- 
tors, Also,  the  author  of  the  arti- 
cle in  question  says  that  a  prod- 
uct detector  only  works  with 
SSB.  This  just  isn't  true.  Both 
theory  and  practice  prove  that  a 
good  product  detector  works 
well  on  AM,  and  I  have  used  my 
product  detector  for  years  to 
pick  up  AM.  Actually,  a  good 
product  detector  wili  dig  AM 
out  of  the  noise  when  a  regular 
envelope  detector  won't  do  the 
job.  Also,  a  simple  product 
detector  wiU  work  on  DSB,  and 
most  authorities  agree  that 
understandable   speech   will 


come  out  of  such  a  detector 
even  if  the  inserted  carrier  Is  as 
much  as  30  Hz  away  from  the 
proper  value.  Actually,  the  car- 
rier can  be  derived  from  a  DSB 
signal  by  a  process  of  squaring, 
filtering  and  frequency  divi- 
sion, without  use  of  the  PLL, 
aithough  the  PLL  is  probably 
the  best  method. 

In  another  word  error,  the 
author  says  that  an  AM  detec- 
tor is  nothing  but  a  mixer.  This 
is  wrong,  since  to  mix  some- 
thing you  need  at  least  two  in- 
puts, and  an  ordinary  AM  detec- 
tor has  only  one  input.  Here 
again,  the  meaning  of  words  Is 
involved. 

At  least  five  stereo  AM 
systems  have  been  proposed, 
each  w^th  its  own  advantages 
and  disadvantages.  Whether  or 
not  these  will  prove  to  be  sue- 
cessful  depends  on  many 
economic  and  technical  fac- 
tors, as  the  author  points  out, 
James  N,  Thurston  W4PPB 

Clemson  SC 


COMMUNICASTIISfG 

Just  as  early  experimental 
work  performed  by  amateur 
radio  operators  evolved  into  the 
broadcasting  Industry,  so,  too, 
may  a  new  service  evolve  called 
"communicasting/'  Based  on 
experience  from  amateur  radio 
repeater  operation,  a  petition 
was  filed  In  January,  1977.  by 
WA2RPC  of  the  Center  for  Ad- 
vanced Study  In  Education  of 
the  Graduate  School  of  CUNY 
with  W2KPQ  for  a  new  "Com- 
munity Educational  Radio  Fixed 
Service"  (RM-2846K  This  semoe 
would  employ  the  communl- 
casting  concept. 

Commu  nicest  ing  utilizes  a 
low-power  community  repeater 
station  which  can  transmit 
audio  and  video  signals  a 
distance  of  thirty  miles  or  more 
from  a  high  antenna.  Signals 
can  input  the  repeater  from 
many  parts  of  the  community 
and  the  output  can  be  transmit- 
ted on  an  unused  UHF  TV  chan- 
nel for  anyone  to  receive.  The 
petitioners  and  others  filing 
comments  had  additionally  re- 
quested that  these  low-power 
facilities  be  exempted  from 
conforming  to  rigid  broadcast 
standards  in  order  to  minimize 
costs. 

In  a  recent  "Memorandum 
Opinion  and  Order"'  on  RM- 
2846,  the  FCC  praised  the  com- 
municasting  concept  and 
made  it  part  of  a  broad  'Inquiry 
into  the  Future  Role  of  Low- 
Power  Television  Broadcasting 
and  Television  Translators  in 
the  National  Telecommunica- 
tions System"  (Notice  of  In- 
quiry in  BC  Docket  No,  78-253), 
The  FCC  stated  that,  "The  peti- 
tion and  comments  by  others 

Continued  ort  page  102 


15 


RTTY  Loop 


KEtBOARD 


n 


Marc  L  Leavey,  M.D.  WA3AJR 
4006  Winfm  Road 
flandanstDwn  MD  27133 

How  did  the  old  song  go, 

"Letlers,  we  get  letters  . .  /*? 
Well,  so  do  I,  and  this  month  I'll 
dip  into  the  malibag  and  see 
what  l<fnd  of  items  are  brought 
forth. 

Chris  Sheridan,  of  Yonkers, 
New  Yorit,  sends  aiong  a  lape 
and  notes  that  the  printing  on 
the  tape  shifts  from  letters  to 
figures,  but  that  the  transmitted 
print  appears  correct.  In  order 
to  diagnose  this  probSem,  you 
must  be  able  to  read  the  perfo- 
rations directly  on  the  punched 
tape.  Teletype*  has  been  nice 
and  standardized  the  format  in 
which  the  tape  Is  punched. 
Looking  at  the  tape  from  the 
top,  perforations  are  for  bit  1, 
bit  2,  sprocket,  bit  3,  bit  4,  and 
bit  5.  Furthermore,  typing  reper- 
forators put  the  typed  character 
six  places  behind  the  punched 
representation.  Looking  at  the 
tape  that  was  sent  (I'm  sorry 
that  there  is  no  way  to  repro- 
duce it  for  publication),  the 
printing  reads:  "WEL  8  >))3rS\ 
Looking  at  the  perforations, 
one  sees  that  what  should  have 
been  the  second  "L*'  of 
"WELL/'  01001  binary,  has 
been  changed  to  11011,  pre- 
sumably by  a  noise  pulse.  This 
is  the  code  for  FIGURES  and 
was  responsible  for  the  shift  in 
case  on  the  tape.  I  assume  that 
your  page  printer  Is  equipped 
with  the  ^'downshift  on  space" 
feature  that  returns  the  car- 
riage to  LETTERS  after  a  space. 
Thus,  the  space  after  the 
"WEL"  would  have  returned 
printing  to  the  normal  mode* 

Chris  also  asks  three  ques- 
tions echoed  by  many  other 
hams,  with  detaiisonly  slightly 
changed.  He  wants  to  know: 

1  Do  you  recommend  the 
Kenwood  (he  has  the  TS-520)  or, 
to  you,  which  is  the  best  re- 
ceiver/transmitter to  use  for 
RTTY? 

2.  Is  the  HAL  ST-5  good,  or 
should  I  try  for  a  better  unit? 

3.  Do  you  have  any  recom- 
mendations for  a  linear? 

Being  of  a  conservative  and 
frugal  nature,  the  answer  to 


your  first  question,  to  me  at 
leasts  is  obvious.  If  you  have  a 
station  that  works  on  SSB  or 
GW  and  you  can  get  it  on  RTTY, 
lise  itl  There  probably  Is  no 
"best"  RTTY  rig  any  more  than 
there  is  a  "best"  SSB  rig  or 
"best'*  two  meter  FM  transceiv- 
er, if  there  were  one  clearly  su- 
perior rig,  it  would  quickly 
eclipse  all  others  on  the  market. 
The  presence  of  variety  pro- 
vides for  an  Individual's  taste, 
and  what  is  great  for  you  may 
be  rotten  for  me,  and  vice  versa. 
Similarly,  to  those  of  you  using 
Inexpensive  demodulators, 
such  as  the  HAL  ST-5  or  Fiesher 
170»  as  long  as  they  perform 
within  your  expectations,  use 
them!  It  will  become  painfully 
obvious  when  you  try  to  do 
more  than  these  otherwise  fine 
units  can  do.  There  is  no  reason 
to  discard  a  perfectly  good 
piece  of  equipment  merely  be- 
cause it  does  not  meet  some- 
one's arbitrary  description  of 
"the  best."  I'm  going  to  punt  on 
the  linear  question.  I  don't  use 
one  myself,  but  1  guess  iikeany- 
Ihing  else,  any  clean  linear  that 
can  be  run  key-down,  all  right 
with  decreased  specs,  is  fine. 
Get  what  you  can  afford  that 
will  make  you  happy,  i  hope 
that  kind  of  puts  the  philosophy 
of  equipment  procurement  into 
the  proper  perspective. 

While  irs  not  strictly  RTTY, 
I'm  a  sucker  for  DX  requests, 
and  from  a  fellow  physician,  I 
find  it  hard  to  refuse.  P.  P. 
Kurlan,  IVl.D.  VU2PP,  needs 
help  in  setting  up  an  SSTV  rig  In 
India.  He  notes  that  he  is  par- 
ticularly Interested  in  an  Atlas 
21  OX  or  equivalent,  and  some- 
thing on  the  order  of  a  Robot 
400  converter.  Anyone  who  can 
help  is  invited  to  write  him  at: 
Dr.  P.  P.  Kurian  fWBBS,  MD, 
Kelachandra  Medical  Centre, 
Chingavanam-esessip  Tf.  Res. 
396,  Hosp.  334,  Kottayam  Dt. 
Kerala,  S.  India, 

While  we're  on  the  subject  of 
help,  all  you  whale  lovers  may 
be  interested  in  a  request  from 
the  Greenpeace  Foundation  of 
America.  They  need  help  in  get- 
ting an  L015G  Intelex  Systems 
teleprinter  on  80  wpm.  Richard 


Ham  Help 


Where  can  I  obtain  a  con- 
tinuity tester  that  produces  an 
audible  tone  which  changes 
with  resistance?  I  am  presently 
using  a  bell  taped  to  a  battery, 
but  of  course  this  does  not  pro- 
vide the  information  a  variable 
tone  would. 


What  I  had  In  mind  was 
something  like  a  conventional 
VOM,  but  with  a  small  speaker 
to  give  an  audio  clue  as  to  what 
the  needle  was  doing. 

Roger  Deran 

21  Betty  Drive 

Santa  Barbara  CA  93105 


^ 


I 


isns 


"shift 

POT' 


3€K 


m 


1 


001 


^h 


V  TO  TDI 
^  tCli/AII  CRYSTAL) 


15359 


0  047 


^Y 


Ih 


IK 


Z201I 
—*M^ — 


i 


t*jPfHll# 


9V 


Fig.  7.  FT-101&FSK. 


Dillman  N6VS  notes  the  ma- 
chine was  made  by  Standard 
Elektrik  Lorenz,  AG.  Write  him 
at  240  Fort  Mason,  San  Fran- 
cisco, CA  94123,  If  you  can  help. 
The  whale  will  thank  you,  I'm 
sure. 

For  those  of  you  within  the 
sphere  of  influence  of  Harris- 
burg,  Pennsylvania,  I  have  a 
note  here  from  Bob  Marzarl 
WA3AVX  about  the  WR3AC0 
RTTY  repeater.  It  seems  as 
though  the  machine  has  just 
had  its  second  birthday,  and 
the  "parents"  celebrated  by 
equipping  It  with  a  new  ma- 
chine. With  a  Super  Station- 
master  at  1600  feet  above  sea 
level  atop  Blue  f^ountain,  and 
25  W  erp,  the  signal  covers  the 
surrounding  area  well.  Digital 
input  and  output  is  provided  by 
a  system  built  by  local  hams. 
Bob  tells  me  that  they  are  plan- 
ning a  link  with  the  Eaglevilte, 
Pennsylvania,  repeater,  north- 
west of  Philadelphia.  This 
sounds  like  a  super  idea,  and 
with  the  possibility  of  ASCII 
lingering  as  of  this  writing, 
RTTY  repeaters  could  become 
the  first  step  to  turning  any 
RTTY  station  into  a  computer 
terminal. 

Somehow,  It  wouldn't  seem 
right  to  have  a  column  without 
at  least  one  diagram.  This 
month*s  is  provided  by  Dick 
Beagell  WDeCEB.  Dick  notes 
that  by  carefully  followmg  the 
directions  given  \n  the  manual 
for  the  Yaesu  FT-101B,  RTTY 
could  be  generated.  Only  one 
problem:  It  was  upside  downl 
Fig.  1  is  the  circuit  Dick  came 
up  with.  He  notes  that,  as  in 
many  other  keyer  circuits,  the 
keying  contacts  must  be  "dry," 
that  is,  outside  of  the  loop.  This 
means  that  in  order  to  get  local 
copy  while  transmitting^  usual- 
ly a  good  idea  unless  you  are  a 
perfect  speller,  you  should 
either  use  a  polar  relay  to  key 
the  transmitter,  or  a  magnetic 
reed  relay,  as  described  here 
several  months  ago.  Dick  says 
that  adjusting  TC4  and  the  shift 
pot  should  allow  UO-Hz  shift 
without  any  problems.  He  built 
his  on  a  small  terminal  strip 
and  mounted  it  to  the  **FIXED 
XTAL"  board  on  top  of  the  VFO. 

Does  anyone  know  what  ever 
happened  to  the  RTTY  Journaf 
and   the   New   Jersey   Green 


Keys*^  Several  readers  have 
written  to  say  that  they  cannot 
get  mail  to  these  publications 
and  wonder  if  they  still  exist,  I 
don't  know,  myself.  Do  any  of 
you? 

Many,  many,  many  readers 
have  asked  me  a  variation  of 
the  'Where  can  I  buy  a  frammis 
zacher?"  question  so,  some- 
what against  my  better  judg- 
ment, I  have  decided  to  pass 
along  that  information  about 
RTTY  sources  thai  crosses  my 
desk.  Van  W2DLT  runs  a  joint 
known  as  Teletypewriter  Com- 
munications Specialists,  They 
sell  and  rent  just  about  any- 
thing in  Teletype,  Baudot,  Mur- 
ray, ASCII,  Of  what  have  you. 
See  their  ad  in  73  or  Kilobaud, 
or  drop  them  a  note  at  550 
Springfield  Avenue,  Berkeley 
Heights  NJ  07922.  Another  out- 
fit, Typetronics,  reachable  at 
Box  8873,  Ft.  Lauderdale  FL 
33310,  sends  along  an  eight- 
page  list  of  equipment  avail- 
able. It  appears  they  have  ma- 
chines, parts  and  accessories 
for  Teletype  and  Kleinschmldt 
machines.  I'm  sure  they  would 
be  happy  to  send  you  a  list,  tool 

A  tip  of  the  hat  to  Bill  Bennett 
K3TNM,  Bill  RIcharz  WA4VAF, 
and  Ric  Cooney  WB3DJV,  all  of 
whom  have  let  me  know  that 
the  RTTY  receiving  program 
published  here  in  July  is  up  and 
running  at  their  stations.  In  an- 
swer to  their,  and  others',  ques- 
tions, modular  sending  and 
stunt-box  programs  are  under 
development,  and  will  be  pub- 
lished as  soon  as  I  am  100% 
convinced  that  they  are  bug- 
free-  For  those  still  having  prob- 
lems with  that  program,  the  one 
bug  that  creeps  up  with  fast  ter- 
minals has  been  patched,  and 
the  program  should  work  with 
any  terminal  of  300  baud  or 
faster.  The  updated  source  last- 
ing (Ver.  3.1)  Is  still  available  for 
an  SASE  and  one  dollar  to 
cover  copying  costs. 

Other  hams  have  let  me  know 
there  is  a  wide  range  of  equip- 
ment in  use  out  there*  from  the 
most  elementary  to  highly-sa- 
phisttcated  microprocessors. 
We've  heard  from  Model  15s 
and  Digital  Group  stations.  Tm 
still  compiling  a  list  of  what  you 
send  in,  and  when  it  looks  pre- 
sentable, I'll  let  you  all  in  on 
it . . .  right  here,  in  RTTY  Loop! 


16 


tit 


The  World  s  Best  2  meter  Mobile  Team. 


Q  ? 


,-,tM    rt=-E*E 


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O  O  CI  s 

a  a  Q 


iX      03 


s  5Upenor  moDiie 
teams  up  with  the  new  RM2  to  provide 
the  most  versatile,  convenient  and 
high  quality  2  meter  mobile  station 
available  anywhere.  The  IC-245's  out- 
standing LSI  performance,  controlled 
by  the  RM2's  microprocessor  fre- 
quency selection  and  multi-frequency 
memory  storage,  puts  full-band  cover- 
age speed  and  accuracy  right  where 
you  want  it — at  your  fingertip. 

With  remarkable  compactness,  out- 
standing stability,  and  Amateur 
Radioes  most  advanced  computer 
technology,  ICOM's  Mobile  LSI  Team 
makes  all  others,  new  and  old,  seem 
obsolete-  Now  incremental  step  pro- 
gramming and  instant  recall  memories 
are  added  to  the  IC-245  s  fully  synthe- 
sized, multi-mode  mobile  operation. 
I 

The  IC-245/SSB  alone,  even  before 
the  introduction  of  the  RM2  remote 
microprocessor,  has  proven  itself  to  be 
the  most  versatile  2  meter  mobile  radio 
made-  With  quality  features  like  two 
built-in  VFO's.  which  can  handle  splits 
of  600  KHz  and  1  MHz  easily,  the 
IC-245  is  the  fuU-feature,  top  quality 
radio  that  every  2  meter  mobile  Ham 
wants*  *,.  .^^„__ 


[tiitfj 


best  and  who  are  now  operating  with 
the  IC-245  often  report  their  satis- 
faction to  US-  Here  is  just  some  of  the 
feedback  I  COM  has  received  on  the 
IC-245: 

"A  realty  flexible  radio,  SSB  has  very  good 
copy  over  long  distance  when  mobile:  tested 
at  25  miles  so  far,'* 

Richard,  K0GHC 

"Beautifully  made  radio:  and  the  signal  re- 
ports have  been  great." 

Donley,  N6CD 

"Exceptional  receiver:  and  simple  to  use  while 
mobile/* 

Clark.  WD6AVT 

"Very  pleased  with  design  and  construction," 
Horace.  K3KT 

"Your  equipment  is  excellent:  keep  it  coming,*' 
Gary.  WD8CAO 

"Very  pleased  with  unit** 
Kenneth,  W3EMT 

"Excellent  Equipment." 
Tom,  WB7SAB 

"A  great  rig  to  get  into  2  meters  with.  It  s 
super!"' 

Edward,  W60SV 


All  ICOM  f«cfio«  «i9nlficftntly  «3tc««d  FCC  ivgtiTalfoiift  ftmltlng  sptirfou*  emtssioiw 


HF/VMF/^UHF  AMATtUR  AM^  MARINE  COVUUNiCAtlON  EOUIPMENT 


(M> 


ICOM 


ICOM  WEST.  iMC. 
Suites 

13256  Noflhfyp  Way 
Believue  Wash  98005 
\2m\  747-9020 


DiSTRiaUTFO  BY 


ICOM  EAST.  INC. 
Suite  307 

333 1  Tov^erwcMXf  Dtive 
DaiLis.  Tescas  75234 
(21 4»  620-2780 


JCOM  CANADA 

7087  Victoria  Dnve 

Vancouver  S.C  V5P  3Y9 

Canada 

I604i  321-1833 


Looking  H^est 


BiH  Pasternak  WAGiTF 
24B54C  NewHaU  Ave. 
N8whaftCA9f321 

Last  month,  we  left  you  with 
quite  a  cNlf-hanger.  We  had  our 
favorite  repeater,  '*WR  what- 
ever/*  as  the  target  of 
maticious  interference  by  a 
known,  self-confessed,  pub- 
Itcly^denttfied  repeater  jam* 
mer*  We  had  set  some  ground 
rules  which  stated  that  no 
violent  means  could  be  used  to 
combat  this  problem.  Also,  in 
our  hypothetical  case  we  had 
stated  that  our  ''good  guys" 
had  tried  every  method  of  ob- 
taining relief  from  the  situation 
through  the  FCC  and  other 
agencies— to  no  avail-  How 
would  you  handle  It? 

By  the  way,  for  those  of  you 
who  might  doubt  that  abuse  of 
our  relay  systems  can  manifest 
itself  to  an  extent  such  as 
outlined,  may  I  suggest  that 
you  stop  here  for  a  moment  and 
grab  your  October  73.  In  it  you 
will  find  a  story  entitled,  "The 
Ultimate  T^Hunt/'  by  Bob 
Thornburg  WB6JPi.  Read  it;  it 
will  tell  you  quite  explicitly  the 
length  to  which  a  person  ap* 
parently  filled  with  hate  toward 
either  a  repeater  or  repeater 
licensee  will  go  in  an  effort  to 
make  this  "hate'*  known.  The 
article  breaks  down  into  dollars 
and  cents  the  cost  that  such 
wHIful,  illegal,  and  malicious  in- 
terference can  have  for  us.  Hav- 
ing lived  through  the  days  of 
what  I  term  '^Jambox  i/'  I  con- 
sider that  act  and  all  acts  like  It 
to  be  a  direct  assault  upon  the 
integrity  of  the  amateur  service 
and  each  one  of  us.  In  the  end, 
no  matter  what  method  is  used 
to  handle  each  individual  case, 
the  cost  comes  out  of  our  own 
collective  pockets.  Read  or 
reread  "The  Ultimate  T-Hunt;* 
and  then  continue  reading  this 
article. 

The  obvious  next  question  Is, 
Is  there  a  solution?  Is  there  a 
way  that  amateur  radio  can  rid 
Itself  of  those  from  within  who 
seek  to  destroy  us?  Last 
month,  I  intimated  that  such  a 
way  might  exist,  though  I  can- 
not personalty  take  credit  for 
developing  it.  The  vJews  you  are 
about  to  read  are  those  of  an 
amateur  who  is  also  a  very  com- 
petent attorney.  His  name  is 
Joe  Merdier  N6AHU.  Joe  came 
up  through  the  ranks,  so  to 
speak,  starting  with  CB  radio 
and  moving  up  to  an  Advanced 
Class  license  within  the  short 
period  of  a  year.  Joe  is  an  avid 
tow-band  DXer  who  also  en)oys 
VHF  FM  on  both  2  meters  and 
220  MHz. 

When  we  were  potting  to- 
gether    the   '*First    Annual 


VHF/UHF  Band  Planning, 
Voluntary  Coordination,  and 
Technical  Advances  Seminar'* 
tor  the  ARRL  National  Conven- 
tion, we  realized  that  one  topic 
of  extreme  importance  rarely 
covered  at  these  meetings  was 
dealing  with  just  such  cases  of 
malicious  Interference,  I  knew 
how  devoted  Joe  was  to  trying 
to  curb  this  problem,  and  how 
he  was  trying  to  use  some  of 
his  expertise  to  help  guide 
others  in  this  regard.  Therefore, 
Joe  was  considered  to  be  an 
ideal  speaker  on  the  topic.  He 
was  invited  to  take  part  In  the 
seminar;  the  following  Is  a 
transcription  of  his  talk: 

'*The  title  of  this  talk  is 
'Malicious  Interference:  What 
Can  You  Do?'  I  would  prefer  to 
title  my  brief  statement,  'Now 
That  You  Have  the  Tiger  by  the 
Tail,  What  Do  You  Do?' 

"The  jammer  poses  a  unique 
problem  to  the  VHF  user  We 
have  found  through  experience 
that,  in  most  cases,  the  FCC  or 
perhaps  other  governmental 
agencies  charged  with  enforc- 
ing the  various  codes  will  not 
proceed  in  cases  of  malicious 
interference  (to  amateur  com- 
munication). There  are  ways  of 
getting  around  this,  I  would  like 
to  point  out  a  few  suggestions 
based  on  the  cases  I  have  been 
Involved  with,  I  got  involved 
because  I  don't  know  how  to 
say  no.  My  friends  got  involved 
and  said  that  they  needed  help. 
When  you  start  dealing  with 
government  agencies,  taking 
statements,  and  wanting  signed 
statements,  people  become 
scared. 

"The  tracking  down  and  DF* 
Ing  of  a  jammer  I  won't  go  into, 
but  it  does  have  legal  ramifica- 
tions. An  incident  occurred  last 
week  in  Los  Angeles,  on  a  very, 
very  popular  repeater.  An  in- 
dividual was  caught  jamming. 
A  group  of  men  drove  up  to  his 
yard.  They  (the  T-hunters)  rang 
his  door  belt;  the  door  belt 
came  out  over  the  air.  The  jam* 
ming  Immediatefy  ceased 
when  the  door  bell  was  rung. 
Later,  the  purported  jammer 
called  the  repeater  owner  and 
asked  him  to  *call  off  your 
boys.'  They  had  just  slashed 
the  four  tires  on  the  jammer's 
truck* 

"Now,  the  first  reaction  that 
one  might  have  is:  'That's 
good."  Somebody's  going  to  get 
his  comeuppance.  However, 
that  statement  gives  rise  to 
many  statements  legally.  Is  the 
repeater  owner  responsible  for 
the  acts  of  his  users?  Is  an 
'association*  or  club  that  spon- 
sors or  aids  in  the  upkeep  of  a 
repeater  responsible  because 
someone  goes  out  and  slashes 


Joe  Merdier  N6AHU  addresses  seminar  at  San  Diego, 


the  tires  of  someone  who  has 
been  ^announced'  as  being  a 
iammer?  It  is  my  feeling  that, 
and  I  am  actually  doing  it  for 
this  one  particular  repeater;  the 
best  thing  is  to  form  a  nonprofit 
corporation.  Any  activities 
such  as  DFIng,  T^hunting,  or 
any  activities  involved  In  track- 
ing down  the  offenders,  releas- 
ing information,  etcetera,  will 
be  handled  through  this  non- 
profit corporation.  The  purpose 
is  that  we  are  volunteers.  We 
are  In  a  hobby  for  fun.  What 
happens  if  you  make  a  state- 
ment on  the  air  and  a  'guy*  says 
prove  it  and  sues  you?  Liable 
and  slander  laws  do  apply^  and 
while  most  people  only 
threaten,  once  in  a  while  you 
find  someone  who  will  really  go 
through  with  It.  What  happens 
when  you  are  sued?  Legal  fees 
are  not  cheap.  The  costs  of 
legal  fees,  filing  fees,  deposi- 
tion fees— those  items  add  up 
quickly.  Quite  frankly,  it  can 
break  an  individuaL 

"When  you  get  into  court, 
you  never  know  who  is  going  to 
win.  In  my  opinion,  it  is  general- 
ly the  attorneys.  I  have  to  be 
qutle  frank  about  it.  In  my  prac- 
tice I  try  to  avoid  litigation 
where  possible  and  will  dis- 
cuss with  clients  from  a  stand- 
point of  practicality  what  to  do 
In  a  lawsuit.  Realty,  you  get  very 
few  clients  who  can  afford  to 
fight  as  a  matter  of  'principle/ 

"How  do  you  protect  yourself 
and  the  users  of  your  repeater? 
For  example,  I  was  involved  In  a 
case.  There  was  an  announce- 
ment made  (about  the  matter).  I 
should  point  out  that  1  was  only 
involved  actually  in  coordinat- 
ing (the  matter),  I  did  not  do  any 
of  the  DFIng.  I  played  a  very 
small  role  In  it.  In  actuality,  1 
provided  advice.  There  was  a 
well-known  individual  whom  we 
have  decided  to  call  'W6JAM; 


Those  of  you  outside  the  Los 
Angeles  area  may  not  have 
heard  atK}ut  this  IndividuaL  The 
most  foul  mouthed  Individual  l 
have  heard.  Almost  made  me 
want  to  take  the  two  meter 
radio  out  of  the  car.  It  turned 
out  to  be  someone  1  thought 
was  a  friend. 

"It  created  all  types  of  prob- 
lems. What  do  you  do  if  the 
federal  government  refuses  to 
act  in  a  case  such  as  this?  How 
can  you  make  an  announce* 
ment  to  let  other  amateurs 
know  that  this  individual  is  the 
jammer?  How  can  you  make 
these  statements  and  do  these 
things  without  exposing  your- 
self to  liability?  It  is  my  opinion 
that  a  day  Is  coming  when 
perhaps  the  repeater  councils 
should  incorporate  as  non- 
profit corporations  so  that  the 
individuals  working  on  behalf 
of  such  repeater  councils  can 
go  ahead  and  make  statements 
or  publish  press  releases  (on 
such  matters)  and  not  worry 
that  they  as  individuals  making 
such  a  press  release  or  par- 
ticipating in  such  matters 
might  be  exposed  (to  individual 
liability).  You  can  insure  a  cor- 
poration far  more  easily  than 
an  individual  (against  such 
liabilities), 

^'Another  thing  It  can  do  is 
permit  such  a  corporation  to  go 
into  court  on  such  matters, 
WESTCARS  tried  it,  but  I  think 
they  tried  it  in  state  court.  I 
think  that  was  their  downfall. 
They  should  have  gone  to 
federal  court;  however,  that  is 
second  guessing.  This  Is  one 
avenue  in  stopping  the  prob- 
lem, 

"What  it  is  going  to  take  Is 
some  jammer  being  prosecut- 
ed and  placed  in  jail.  How  do 
you  get  the  federal  government 

Continued  orr  psge  f24 


18 


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19 


DX 


Chuck  Stuart  NSKC 
51 W  Merwfee  Drive 
MtK  TX  75227 

Here  it  Is  December  already, 
and  it  appears  that  good  old 
Saint  Nick  wllf  be  bringing 
plenty  of  exotic  DX  to  the  de- 
serving. Of  course,  there  is  no 
need  to  ask  If  you  Ve  been  good 
or  not.  That  just  comes  natural- 
ly with  being  a  DXer.  You  are 
one  of  the  chosen  few, 

A  couple  of  months  back,  In 
the  October  column,  we  laid 
out  our  ideas  and  plans  for 
what  we  hoped  to  be  able  to  do 
with  this  column.  This  included 
a  monthly  DXer  profile,  lots  of 
pictures,  stories  on  the  latest 
DXpedltions,  and  much  more. 
Mostly,  we  want  to  give  you 
something  we  feel  has  been 
missing  in  the  DX  columns 
presently  available — a  column 
with  pictures  and  stories  about 
the  DXers  rather  than  the  OX, 
Of  course,  we  will  continue  to 
keep  you  up  to  date  on  "what's 
happening/'  but  it's  the  per- 
sonal side  we're  looking  for. 

To  do  this,  we  need  your 
help.  Let  us  hear  from  you.  Tell 
us  what  we  are  doing  right  and 
what  you  feel  could  be  done 
better.  Send  pictures  of  your- 
self and  your  station.  Black  and 
white  or  color— we  can  print 
either  one.  Let  us  know  whom 
you  would  like  to  see  in  the  DX 
Profile.  We  need  lots  of  input 
from  the  readers.  The  more 
Input  we  receive,  the  better  job 
we  can  do  and  the  better  the 
column  will  be.  Merry 
Christmas. 


DX  PROFILE 

This  month's  DX  Profile  is  on 
one  of  the  best  known  and  most 
popular  DXers  around,  Lenny 
Mendel  K50VC. 

Lenny  first  became  interest- 
ed in  amateur  radio  while  at- 
tending a  technical  vocational 
high  school  in  New  York  City. 
He  was  first  licensed  while  still 
a  junior  in  high  school  in  1945. 
but  due  to  the  war,  he  received 
no  call  at  that  time.  By  the  time 
Lenny  graduated  from  high 
school,  he  had  earned  a  com^ 
merclal  radiotelephone  license 
as  well  as  first  and  second 
class  radiotelegraph  licenses. 
He  had  also  received  the  call 
W20VC. 

After  a  hitch  In  the  Coast 
Guard  as  a  radio  operator 
aboard  a  Coast  Guard  cutter 
and  a  short  tour  as  a  commer- 
cial radio  operator  on  a  sea* 
going  tug,  Lenny  joined  the 
sales  staff  of  Harrison  Radio  in 
New  York  City. 

In  1951,  Lenny  joined  the 
New  York  City  Police  Depart- 
ment and  became  a  member  of 
the  Elite  Emergency  Squad.  To- 
day this  department  is  known 
as  SWAT.  If  there  is  a  better 
training  ground  for  the  twenty 
meter  wars,  we  can't  think  of 
one.  In  1971,  he  retired,  com- 
pleting twenty  years  of  service. 

1972  was  not  one  of  Lenny's 
best  years.  He  was  sued  by  five 
of  his  neighbors  for  a  cool  one 
million  dollars.  They  not  only 
claimed  TVI,  but  charged  Lenny 
with  maliciously  operating  his 
radio  and  causing  severe  dam* 
age  to  their  health  from  staying 
awake  all  night  waiting  for  his 


Lenny  Mendel  K50VC,  as  a  member  of  the  New  York  City  Police 
Department's  Eifte  Emergency  Squad.  He  seems  to  be  saying, 
'*Whaf  do  you  mean  I'm  not  in  the  CUpperton  tog?" 


tower  to  fall  on  their  heads.  The 
case  made  it  all  the  way  to  the 
New  York  State  Supreme  Court 
before  it  ended  without  the 
neighbors  getting  a  cent.  Lenny 
and  his  wif^  Norrr^a  feel  that 
they  never  could  have  made  ft 
through  this  period  In  their  lives 
without  the  moral  and  financial 
support  provided  by  their  many 
friends, 

tt  was  during  that  time  that 
Lenny  became  good  friends 
with  Bud  W5WZN  and  several 
other  Arkansas  DXers.  When 
the  Arkansas  DX  Association 
held  a  special  meeting  for 
Ahmed  AP2AH,  Lenny  and 
Norma  decided  It  would  be  a 
perfect  time  to  visit  Arkansas 
and  meet  some  of  their  many 
friends  in  that  area.  After  a 
short  visit,  during  which  time 
they  fell  in  love  with  Hot 
Springs,  Lenny  and  Norma  put 
their  New  York  house  on  the 
market  and  moved  to  Arkansas. 
Lenny  does  admit,  though,  that 
before  they  signed  the  papers 
on  their  new  home,  he  set  up  a 
rfg  in  the  driveway  just  to  make 
sure  he  could  gel  out  okay  from 
that  location.  Now  there  Is  a 
man  who  has  his  priorities 
straight- 
Lenny  says  that  DXing  from 
Arkansas  is  just  great.  You 
have  a  good  shot  to  Asia  and 
the  Pacific,  but  it  gets  a  little 
rough  toward  Europe.  Regard* 
less  of  the  conditions,  Lenny 
has  earned  58WAS,  5BDXCC, 
Single  Band  WAZ,  and  is  wait- 
ing for  cards  from  601F6  and 
HZ1BX/8Z4  to  bring  his  con- 
firmed DXCC  total  to  319 
countries. 

Lenny's  equipment  Includes 
a  Drake  T4XC,  R4B,  and  a  Henry 
2k  linear.  Antennas  consist  of 
a  KLM  5-element  Big  Stick  on 
twenty  and  a  Wilson  Duo- 
bander  for  ten  and  fifteen. 

Lenny  and  his  wife  Norma,  a 
native  of  Wakefield,  Mass., 
have  three  children.  Ken  is  a 
doctor  at  Columbia  Presbyter- 
ian Hospital  in  New  York  City, 
Kathy  Ann  teaches  eighth 
grade  in  Humble,  Texas,  and 
the  youngest,  Jo-Ann,  is  a 
junior  at  Lake  Hamilton  High 
School  who  plans  to  become  a 
lawyer.  None  is  interested  in 
amateur  radio. 

Lenny  is  one  of  the  real 
gentlemen  in  a  highly  competi- 
tive hobby.  The  next  time  you 
hear  K50VC  on  the  air,  give  him 
a  calL  You'll  be  glad  you  did. 

DX  NOTEBOOK 

Nigeria— 5N2NAS 

Ron  Veelik  WA6LTH  forward- 
ed a  letter  he  recently  received 
from  Kunle  5N2NAS,  secretary 
of  the  Nigerian  Amateur  Radio 
Society,  explaining  the  present 
situation  concerning  amateur 
radio  operation  In  Nigeria.  In 
November,  Emergency  Regula- 
tion Decree  No.  24  of  1966  was 
lifted.  Prior  to  this,  it  was  un- 


lawful to  bring  amateur  radio 
equipment  into  Nigeria  and  few 
if  any  new  licenses  were  being 
issued,  especially  to  foreign- 
ers. Now,  with  the  lifting  of 
Decree  No.  24,  it  is  again  possi- 
ble for  foreigners  to  obtain  op- 
erating  permission.  If  you  are 
interested  in  operating  from 
Nigeria,  write  to  Oyekunle 
Ajayi,  Nigerian  Amateur  Radio 
Society,  PC  Box  2873,  Lagos, 
Nigefia.  Tell  them  when  you  are 
coming,  how  long  you  plan  to 
be  there,  and  where  you  will  be 
staying.  If  you  stay  in  Apapa  or 
Lagos,  you  can  receive  permis- 
sion to  operate  from  the  club 
station,  5N2NAS.  Present  club 
members  are  5N2AAJ,  5N2AAE, 
5N2AAK,  5N2AAV,  5N2ESH, 
and  5N2NAS.  Kunle  states  that 
the  NARS  members  are  vitally 
interested  in  W ARC  79,  and  he 
feels  that  we  need  well-disci- 
plined radio  amateurs  around 
the  world  to  justify  the  use  of 
our  old  and  new  frequencies. 

Sable  Island— VGW-211 

The  ARRL  has  refused  to  ac- 
cept contacts  with  VGW-211  for 
DXCC  credit,  citing  DXCC  rule 
number  6  as  the  reason.  Rule 
number  6  states  that  "All  con- 
tacts must  be  made  with  ama- 
teur stations  working  in  the 
authorized  amateur  bands  or 
with  other  stations  licensed  to 
work  amateurs."  The  discredit- 
ed contacts  were  made  August 
8th  and  9th.  Later  contacts 
made  while  the  station  was 
signing  VE1MTA  are  accept- 
able. 

Thailand— HS1AIV 

"Chester"  XV5AC  from  a  few 
years  back  has  returned  to 
southeast  Asia  and  Is  now  sign- 
fng  HS1AIV.  Located  in 
Bangkok,  Chester  has  all  the 
equipment  from  XV5AC  and 
then  some.  In  addition  to  full 
kilowatt  amplifiers,  he  has 
stacked  ten  meter  beams, 
stacked  fifteen  meter  beams, 
two  TH6DXXS,  and  the  big  Tel- 
rex  six-element  twenty  meter 
beam.  On  the  lower  bands,  a 
two-element  forty  meter  t>eam 
and  phased  verticals  on  eighty 
do  the  trick,  Chester  also 
reports  room  for  a  160  meter  an- 
tenna and  plans  to  do  a  lot  of 
operating  on  the  lower  bands 
this  winter.  Chester  will  be 
there  for  a  least  four  years  and 
has  plans  for  a  few  molti-multi 
contest  efforts  as  soon  as  he 
has  the  station  set  up  to  his 
liking  and  all  the  bugs  worked 
out, 

Srf  Lanka— 4S7 

There  are  presently  two  list- 
type  operations  involving  487 
stations.  4S7EA  meets 
WB90QU  Monday  and  Wednes- 
day on  14247  at  2330Z,  QSL  to 
WB90QU.     4S7JD     meets 

Continued  on  p&gi?  74 


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Editor: 

ftobetr  83k er  WB2GFE 
15  Windsor  Dr. 
Ai&i  HJ  08004 


FfT 


ARRL  160  METER  CONTEST 

Starts:  2200  GMT  Friday, 
December  1 

Ends:  1600  GMT  Sunday, 

December  3 
The  annual  ARRL  160  Meter 
Contest  is  open  to  all  amateurs 
on  CW  only.  Multi-operator 
work  is  permitted  and  scores 
will  be  listed  separately  in  the 
results*  but  they  will  not  be 
eligible  for  certificates. 
EXCHANGE: 

RST  and  ARRL  section  or 
country. 
SCORING: 

QSOs  with  amateurs  in  an 
ARRL  section  count  2  points; 
OSOs  with  amateurs  no!  in  an 
ARRL  section  are  worth  5 
points.  DX-to-DX  QSOs  do  not 
count.  Multiplier  is  the  total 
number  of  ARRL  sections  (74), 
VE8,  and  foreign  countries 
worked. 
AWARDS: 

CeriHicates  will  be  awarded 
for  section  and  non-W/VE  coun- 
try high  scores.  Division  high 
scores  will  have  their  section 
award  endorsed  with  an  appro- 
priate seal. 
FORMS: 

It  is  suggested  that  contest 
forms  be  obtained  from  the 
ARRL,  225  Main  St.,  Newington 
CT  06111.  Checksheets  are  not 
required,  but  a  penalty  of  3  ad- 
ditional contacts  will  be  made 
for  each  duplicate  contact. 

These  rules  were  taken  from 
last  year's  contest.  For  com- 


pfete  rufes,  see  the  November 
issue  of  QST. 

VU2  DX  CONTEST-GARDEN 

CITY  CONTEST 

Starts:  1200  GMT 

Saturday,  December  2 

Ends:  1159  GMT 
Sunday,  December  3 
The  Bangalore  ARC  and  the 
VIswesvariah  Industrial  and 
Technological  Museum  Invite 
all  amateurs  to  participate  In 
the  contest  this  year.  Only  two 
bands  are  specified,  the  20  and 
40  meter  bands  for  all  contacts, 
on  CW  only!  Only  one  type  ot 
entry  i$  permitted,  single 
operator.  A  station  may  be 
worked  once  on  each  band; 
VUs  may  contact  other  VUs. 
Valid  points  can  be  scored  by 
contacting  stations  not  In  the 
contest  provided  complete  RST 
exchanges  are  made  and 
logged.  VU  stations  will  work  the 
world  and  vice  versal 
EXCHANGE: 

RST  and  serial  QSO  number 
of  three  digits  or  more. 

SCORfNG: 
Each  completed  QSO  counts 

one  point,  with  the  totlowing 
multipliers:  Power*output 
multipliers— 10  Walts  and 
below  =  5;  up  to  50  Watts  =  3; 
above  50  Watts  =  1.  DX  multi- 
pliers— Asia  =  1;  Europe,  in- 
cluding UK,  Africa,  and  Austra- 
lia -  2;  North  and  South 
America  =  3, 
Note:   For  all   Islands  con- 


Dec  1-3 
Dec  2-3  • 


Dec  2-4 
Dec  3 
Dec  9*10 


Dec  16-17 
Dec  24 
Jan  1 
Jan  6-7 
Jan  13-14 

Jan  27-28 
Jan  28-29 

Feb  24-25 


ARRL  160  Meter  Contest 

International  Island  DX  Contest 

TOPS  CW  Contest 

VU2  OX  Contest 

Alexander  Volta  RTTY  DX  Contest 

Telephone  Pioneers  QSO  Party 

EA  Contest— Phone 

Connecticut  QSO  Party 

Flatland  Farmer  10-X  QSO  Party 

ARRL  10  Meter  Contest 

EA  Contest— CW 

HA-DX 

SOWP  Christmas  CW  QSO  Parly 

HA  5- WW 

ARRL  Straight  Key  Night 
ARRL  CD  Party— Phone 
ARRL  CD  Party— CW 
ARRL  VHF  Sweepstakes 
ARRL  Simulated  Emergency  Test 
Classic  Radio  Exchange 
French  Contest— CW 
French  Contest — Phone 


*  =  described  in  last  issue* 


tacted,  for  the  purpose  of 
multipliers,  the  nearest  con* 
tinent/mainland  will  be  taken 
into  account.  Contacts  with 
maritime-mobile  or  aircraft- 
mobile  stations  do  not  qualify 
for  DX  multipliers.  Contacts 
with  other  portable  or  mobile 
stations  count  as  fixed  sta- 
tions. 
ENTRIES  AND  AWARDS: 

AM  entries  must  be  post* 
marked  no  later  than  Dec.  31, 
197S,    and    addressed    to: 


Bangalore  Amateur  Radio 
Club,  VU2ARC,  PO  Box  5053, 
Bangalore,  560  001  India.  There 
fs  no  entry  fee,  and  the  entry 
must  be  a  true  copy  of  the  ac- 
tual log  for  the  contest  period. 
Three  prizes  will  be  awarded  to 
the  three  highest  scorers.  A 
special  award  will  be  given  by 
the  Federation  of  Amateur 
Radio  Societies  of  India,  All  DX 
stations  who  contact  20  or 
more  VU2  slations  will  be 
issued   a   ''Garden   City   Cer- 


RESULTS  OF  THE  1978  FRENCH  CONTEST 
(Listed  by  call,  number  of  points^  and  number  of  QSOs) 


CANADA 

A1 

VE3KZ          361030 

232 

VE2EHF       72896 

113 

VE2WA          66430 

70 

VE3BR          21200 

53 

A3 

VE3KZ           516420 

349 

VE20G          201880 

206 

VE2AFC        124976 

119 

TERRE  NEUVE 

A1 

V01AW         105480 

130 

A3 

V01AW         5267 

25 

U,S,A. 

A1 

Wi 

W1BWS 

13108 

48 

W10PJ 

10980 

38 

W2 

A1 

W2FAS 

100036 

118 

W2GKZ 

62243 

96 

K2PF 

12870 

39 

N2CM 

11284 

41 

A3 

F2YS/W2 

183084 

162 

K2PF 

360 

8 

W3 

A1 

W3ARK 

154700 

155 

W3HDH 

51968 

91 

N3RL 

6720 

28 

WB3DBI 

360 

6 

A3 

N3RL 

5500 

25 

W3MR 

9212 

35 

WB3DBI 

40 

2 

W4 

A1 

N4NX 

138240 

144 

WB4ENI 

10528 

38 

W4YN 

9360 

38 

AA4RR 

22854 

60 

WB4WHE 

120 

4 

A3 

N4NX 

5000 

2S 

WA4L0F 

2381 

17 

W5 

A1 

K5UR 

20898 

50 

A3 

K5RF 

1000 

10 

W8 

A1 

NSBB 

82871 

108 

W8DS0 

11780 

38 

W8VSK 

5940 

27 

WB8WVW 

40 

2 

A3 

K8MN 

15640 

46 

W66TGS 

490 

7 

W9 

A1 

W90A 

56154 

lis 

K9WA 

14490 

49 

A3 

WA9FZ0 

34633 

69 

W9LKt 

26789 

63 

W9TLU 

6120 

36 

W9SS 

9090 

30 

W0 

A3 

W9CDC 

7364 

32 

2B 


I 


I 


I 


if  engineering 


*t 


% 


i^i^ 


High  qua  (ay  power  swvilch  ai 
mode  switch  on  front  panel. 


MODEL 


BAMD 


BLC 
8LC 
8LC 
BLC 
BLO 
BLD 
BLD 
BLE 
BLE 
BLE 
BLE 


10/70 

2/70 

10/150 

30/150 

2/60 

10/60 

1 0/1 20 

10/40 

2/40 

30/BO 

10/BO 


144 
144 
144 
144 
220 
220 
220 
420 
420 
420 
420 


MHz 
MHz 
MHz 
MHz 
MHz 
M  Hz 
MHz 
MH2 
MHz 
MHz 
MHz 


^1 


e£> 


EMISSION 


CWFM 
CW  FM 
CW -FM 
CW-FM 
CWFM 
CW-FM 
CW-FM 
CW-FM 
CW  FM 
CW-FM 
CW-FM 


SSB/AM 
-SSB/AM 
-SS8/AM 

-sse/AM 

-SSB/AM 
-SSB/AM 
-SSB/AM 
-SSB/AM 
SSB/AM 
SSB/AM 
■SS8/AM 


POWER 
INPUT 

low 

2W 

low 

30W 
2W 

lOW 
IDW 

low 

2W 
30W 

low 


POWER 
OUTPUT 

70W 
70W 

isow 

150W 

aow 

iOW 

120W 

40W 

40W 

dow 
sow 


WIRED   AND 
TESTED  PRICE 

$149,9B 
169.95 
259.95 
239.95 
154.95 
159,95 
259.95 
159.95 
1 79.95 
259.95 
289.95 


F.O^B.  Binghamton-     Pf fc«t  and  spocificatiQnsare  subject  to  change,     Export  prices  are  slightly  higher 


ull  hoaUink  area  mounted 
on  top  for  additional  cooling 


alymmum  extrusion. 


ecigf^ect  for  ease  of  mounting 


FEATURES 

High  efficfency  means  low 
current  drafn* 

Broad  band  design  (no  tuning). 

D  irect  1 2  volt  DC  operation. 

Indicator  lamps  for  On/Off 
and  FM/SS8. 

Relay  swrtchmg  (allows  you 
to  put  amplifier  in  or  out  of 
circuit  at  the  flip  of  a  switch). 

Insertion  toss  of  lessthan  1  dB. 

90  day  limited  warranty  on 
parts  and  labor- 


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DIVISION    OF    BROWNIAN    ELECTRONJCS    CORP. 

320  WATER   STREET  /  BINGHAMTON,  N.Y.    13901  /  Phone  607-723-9574 


tificate."  For  QRP  multiplier,  a 
signed  statement  from  the 
local  club's  secretary  or  presi- 
dent is  mandatory.  The  rul i ng  of 
the  Contest  Committee 
(VU2ARCA/U2VTN)  is  final  in  any 
instance  of  doubt. 

ALEXANDER  VOLTA  RTTY  DX 

CONTEST 

Starts;  1200  GMT  Saturday, 

December  2 

Ends:  1200  GMT  Sunday, 

December  3 

Two-way  RTTY  contacts  be- 
tween stations  of  the  same 
country  are  not  valid.  All  2-way 
RTTY  contacts  with  stations  in 
one's  own  zone  will  count  2 
points;  those  outside  one's 
own  zone  count  tor  points  in  ac* 


cordance  with  the  eKChange 
points  table.  AH  2*way  RTTY 
contacts  made  on  7  MHz  are 
worth  double;  those  on  3,5  or  26 
MHz  are  worth  triple  points. 
Stations  may  only  be  worked 
once  per  band.  A  multiplier  of 
one  is  given  for  each  country 
contacted  on  each  band.  Total 
score  is  total  exchange  points 
times  the  total  number  of 
multipliers  times  the  total 
number  of  QSOs.  Italian  bonus 
points  are  added  last — 1000 
points  for  each  \f\SI\l  contact 
on  aU  bands.  Note:  Each  US, 
Canadian,  and  Australian 
district  wtll  be  considered  a 
separate  country!  Exchange 
consists  of  message  number^ 
RST,  and  zone.  Use  one  log  per 


band.  Logs  must  be  received 
before  Jan.  20,  1979,  to  qualify 
(advisable  to  use  air  mail).  Send 
logs  and  score  sheets  to:  A.  V, 
RTTY  DX  Contest  Committee, 
SSB  &  RTTY  Club,  PO  Box  144, 
22100  Como,  Italy. 

This  contest  is  open  to  SWL 
RTTYers  as  well,  and  the  same 
rules  apply  as  used  for  trans- 
mitting stations;  a  separate 
results  table  will  be  made  for 
these  entries.  In  addition, 
points  and  positions  achieved 
in  this  contest  will  be  valid  for 
inclusion  in  the  "World  RTTY 
Championship''  for  1978. 

TOPS  CW  CONTEST 

Starts:  1800  Gf^T 
Saturday,  December  2 


Ends:  1800  GMT 
Sunday,  December  3 

General  call  is  "CQ  QMF," 
Entry  classes  for  singie-Zmyltl- 
operator.  Use  the  3.5-t0'3.6 
MHz  band.  Look  for  USA 
Novices  between  3.7  and  3.75 
MHz.  Use  low  end  of  band  for 
DX-CW  only! 
EXCHANGE: 

RST  and  serial  number  from 
001. 
SCORING: 

Contacts  with  own  country 
=  1  point;  each  call  area  in 
W/K,  VE/VO,  VK,  and  UA  counts 
as  a  separate  country.  Con- 
tacts with  stations  in  same 
continent  count  2  points,  other 

Continued  an  page  72 


RESULTS  OF  THE 

1978  MICHIGAN  QSO  PARTY 

MICH tG AN  RESULTS 

(Listed  by  Call,  Score  and  County) 


W8PB0 

69,040 

Macomb 

Trophy  Winner 

K8IF 

60.080 

Livingston 

Certificate 

K8R0 

48,080 

Oakland 

Certificate 

WBSTRY 

36,5M 

Wayne 

Certificate 

K8KA/8 

35,259 

Osceola 

Certificate 

KdDD 

33,456 

St.  Clair 

Certificate 

W8LAQ 

31,746 

Eaton 

Certificate 

W8JKU 

27,744 

Oakland 

WD8J0F 

20.460 

Genesee 

Certificate 

N8UM 

19,992 

Washtenaw 

Certificate 

WB8SLQ 

18,312 

Macomb 

W8QGP 

17,580 

Hillsdale 

Certificate 

WD8CQN 

17,353 

Genesee 

WB8YWG 

17,100 

Shiawassee 

Certificate 

NaUM/8 

16,632 

Wayne 

WB8MTD 

15,080 

Jackson 

Certificate 

WD8ITV 

14,699 

Macomb 

KeSJQ 

14,688 

Lapeer 

Certificate 

WD8LRR 

14,460 

GeneMt 

WB8SVI 

14,274 

Macomb 

WD8ITS 

13,986 

Oakland 

WBA7ME 

1 3,542 

Macomb 

K80T 

12,660 

Saginaw 

K8KQJ/8 

12,250 

Oakland 

WD8ECT 

11,440 

Wayne 

WSETH 

9,020 

Oakland 

WD80KM 

B.695 

Bay 

WD8AAE 

7,866 

Marquette 

Trophy— UP 

K80AC 

6,930 

Saginaw 

MuUiOp 

WASVEB 

8,650 

Oakland 

N8WW 

6,480 

Macomb 

WD80VB 

6,407 

Macomb 

WA8MAM 

5,940 

Menominee 

Multi-Op 

N8RW 

4,560 

Saginaw 

woeoKL 

4,532 

Bay 

WB8ZJL 

4,176 

Macomb 

N8HT 

3,924 

Genesee 

WB8BNN 

3,478 

Van  Buren 

Certificate 

WdHW 

3,317 

Genesee 

N8MK 

3,102 

Saginaw 

WD8IKZ 

2,997 

Oakland 

W8WVU 

2,952 

Lenawee 

Certilicato 

WB8AUN 

2,800 

Macomb 

W8WVU|f8 

2,376 

Cheboygan 

Certificate 

WB8NXN 

2,244 

Oakland 

WD80LC 

943 

Genesee 

W68LWS 

792 

Macomb 

K8BWC 

596 

Saginaw 

W8YL 

532 

Lenawee 

WA8EFF 

496 

Macomb 

WD80NM 

442 

Macomb 

WA8T0F 

300 

St.  Clair 

WD8NNM 

72 

Macomb 

K3KXym8 

17,493 

6  Cos. 

Cefflficale 

W8VSK/m8 

3,672 

4  Cos. 

WB8FEZ 

2,349 

Genesee 

Plaque  (VHF) 

WD8LID 

144 

Lapeer 

VHF 

WD8KE0 

21 

Genesee 

VHF 

CLUB  SCORES 

1.  L'Anse  Creuse  ARC~2S6,450  Club  Trophy  (4th  Straight 

2.  Central  Mich.  Conlesters— 62,971  Year) 

3.  Saginaw  Valley  ARA^36,542 

4.  Central  Mich  ARC— 31,746 

5.  Sawyer  ABA— 7,866 


(Listed 
CAL 
CONN. 
DEL. 
GA, 
ILL. 


OUT  OF  STATE  RESULTS 
by  State,  Call,  and  Total  OSO  Points) 


IND. 

IOWA 

LA. 

MD. 

MINN. 
MO. 
NEV. 
NJ. 


NY. 

N.C. 

OH. 

PA. 


Wise. 


ONT. 


WB6DQR 

W1VH 

W3JZA 

WB4RUA 

K9BG 

WB9SMU 

W9QWM 

K9CW 

K9GL 

K9NN 

N9BU 

WBiUCP 

W5WG 

W3BHE 

W3PYZ 

WAiOlT 

WB3JAPW 

W7H1 

WB2LBV 

N2VA 

WA2BYX 

N2RT 

WA20TC 

W2EY 

WD4BEJ 

N4GF 

WD8CQR 

K&BBH 

K3NB 

WA3ZAH 

W3FVU 

W5KL8 

N50Q 

WB9PVi 

K9GDF 

WB9KAR 

VE30AP 

VE3CDK 

VE3BR 


20 
1,84S 

640 
2,525 
5,032 
3,86 1 
2J83 
1,050 

192 
6,996 
1,029 
4,026 
1,881 
6.630 
6,400 
7,912 
1^18 

416 
5,254 
1,098 
96 
4,366 
3,422 

980 

416 

108 
2,889 
2.714 
4,433 

779 

30 

2,002 

224 
1,771 

765 

70 

8,034 

8,000 

5J15 


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28 


CT-50  FREQUENCY  COUNTER 


Outstanding 

Performance 
at  an 

Incredible 
Price 


DESCRIPTION:  The  CT-50  is  a  versatile  and  precision  frequency  counter  whtcfi  will  measure  frequencies  to  60  mHz  and  up 

to  600  tnHz  with  the  CT-600  option.  Large  Scale  Integration,  CMOS  circuitry  and  solid  state  display  technology  have 
enabled  this  counter  to  match  performance  found  in  units  selling  for  over  three  times  as  much.  Low  power  consumption 

(typically  300-400  ma)  makes  the  CT-50  ideal  for  portable  battery  operation.  Features  of  the  CT-50  include:  large  8  digit  LED 
dfspiay,  RF  shielded  all  metal  case,  easy  pushbutton  operation,  automatic  decimal  point,  fully  socketed  IC  chips  and  input 
protection  to  50  volts  to  insure  against  accidental  burnout  or  overload.  And,  the  best  feature  of  alt  is  the  easy  assembly. 
Clear,  step  by  step  instructions  guide  you  to  a  finished  unit  you  can  rely  on.  Use  the  order  blank  betow  or  call  us  direct  and 
order  yours  today! 

SPECiFICATIONS: 

Frequency  range:  5  Hz  to  65  mHz,  600  mHz  with  CT-600 

Resolution:  10  Hz  @  0,1  sec  gate,  1  Hz  (S;  1  sec  gate 

Readout:  8  digit.  0.4"  high  LED,  direct  readout  in  mHz 

Accuracy:  edjustable  to  0.5  ppm 

Stability;  2.0  ppm  over  10^  to  40"*  C,  temperature  compensated 

Input:  BNC.  1  mogohm/20  pf  direct,  50  ohm  with  GT600 

Overload:  50VAC  maximum,  all  modes 

Sensitivity:  less  than  25  mv  to  65  mHz,  50-1 50  mv  to  600  mHz 

Power:  1  tO  VAC  5  Watts  or  12  VDC  g  400  ma 

Size:  6"  x  4"  x2",  high  quality  aluminum  case,  2  lbs 

ICS:  13  units,  all  socketed 

CT-60Q:  600  mHz  prescaler  option,  fits  inside  CT-50 

CB-1 :  Color  burst  adapter,  use  with  color  TV  for  extreme  accuracy 
and  stabilrty,  typically  0.001  ppm 


OPTIONS: 

CB-1  option:  The  CT-50  time  base  may  be  locked  to  an  external 
fraquer^cy  standard.  The  television  networks  maintain  extremely 
accurate  atomic  based  frequency  standards  to  maintain  color  tint  on 
TV  programs.  These  standards  are  typically  accurate  to  one  part  in  10 
to  the  12-  By  locking  Ihe  CT50  to  one  of  these  network  standards,  we 
are  abfe  to  get  super  accuracy.  The  CB-1  adapter  interfaces  a  standard 
color  TV  receiver  to  the  CT-50  so  that  one  can  take  advantage  of  the  TV 
network  frequency  standards.  The  CB-1  requires  connection  to  a  color 
television  for  operation. 

CT-SOO  option r  The  CT600  prescaler  option  enables  the  CT-50  counter 
to  measure  frequencies  as  high  as  600  mHz  with  sensitivity  In  the  20  to 
150  mv  range,  depending  upon  frequency  Typical  sensitivity  at  150 
mHz  is  25  mv.  The  CT-600  mounts  on  the  same  PC  board  as  the  CT-60. 
no  extra  boxes  or  PC  boards  are  required.  The  scaler  utilizes  a  state  of 
IheartECLICchipandtwotransistorpre-amplifier.  thuseliminatlng  the 
need  for  external  pre-amp  devices. 

rsTiss^  BjIsQlrciiss 

Box  4072  Rochester  NY  1 461 0      (71 6)  271  ^6487 


CT-50,  60  mH^  ^^\mter  KH 
CT50  WT  60  ttini.  counter,  wired*  tested 
CT-600,  600  mHz  prescaler  of 
tor  CT-50.  add 

ACCESSORIES 

DC  probe,  direct  input,  general  purpose  type 

Hfgfi  impedance  probe,  does  not  load  circuit 

Low  pass  probe,  used  when  measuring  audio 

High  pass  probe,  reduces  low  freq  picKup 

VHF  flexible  rubber  antenna,  BNC  connector 

Color  burst  adapter,  for  call bfation.  high  accuracy 
typically  0,001  ppm  accuracy,  stability 


29,9^ 

$12.95 

15.95 
15.95 

15.95 
12.95 
14.95 


Ramsey  Electronics 

Box  4072     716-271-6487 
Rochester,  NY  14610    .^lU 


7S 


VSA 


Ktf  I  «'»vni;c 


I 


OuanHy 


Dvscrtpbofi 


Puce 


Shipping,  bandftng,  insurance 
N,Y.  state  residents,  add  tax 

Total 


$5.00 


Name. 


Address. 


I  City. 

( — -- 


^tate. 


^ip. 


A  DXer's 
Dream  Vacation 


try  sunny  Montserrat 


Aim  Adfer  WB6JPZ 

2500  Gran  vilie 
iQsAngeiesCA  90064 


It   was    another    typical 
pileup  on  twenty  meters: 
lots    of    stations    blasting 


away  at  the  rare  one,  hop- 
ing for  that  all-important 
signal    report    which    sig* 


Arrival  at  the  Moritserrat  airport:  Stuart  Sokolm  W6M}E,  left;  Ruby  Bramble  VP2MCB, 

center;  Alar)  Adler  WB6IPZ,  right 


nifies  another  successful 
try.  But  this  time  we  were 
at  the  other  end  and  the 
hundreds  of  calls  were  for 
us.  All  we  could  do  after  it 
was  over  was  grin  at  each 
other  at  the  thrill  of  for 
once  being  the  sought- 
after  instead  of  the 
seekers.  We  were,  for  eight 
days,  VP2M1E,  We  had 
been  lifted  out  of  the 
anonymity  of  our  previous 
existence  as  Alan  Adler 
WB6JPZ  and  Stuart  Sokch 
lin  W6M)E.  For  once  in  our 
careers  as  ham  radio  op- 
erators, we  were  DX. 

The  idea  for  our  expedi- 
tion really  started  more  as 
a  dream  or  wish  rather  than 
a  carefully  planned  and 
well  thought-out  expe- 
dition. After  suffering 
through  numerous  DX  pile- 
ups,  we  started  daydream- 
ing about  how  nice  it 
would  be  to  go  on  a  DX- 
pedition  ourselves.  Lack- 
ing tremendous  financial 
resources  and  a  great  deal 
of  time,  we  resigned  our- 
selves to  more  daydream- 


30 


ing.  We  stiti  hoped  one  day 
to  strike  out  on  a  trip  to 
some  exotic  DX  location 
—  possibly  some  island. 
Our  opportunity  came 
sooner  than  we  expected. 

A  small  ad  in  the  back  of 
a  ham  periodical  told  of  a 
house  which  was  available 
for    rent    complete    with 
tower,    quad,    and    linear 
amplifier    The  house  was 
located  on  a  smalt  obscure 
island    in    the    Caribbean, 
British    West    Indies.    The 
island  was  Montserrat,  of 
which  we  knew  absolutely 
nothing.    Everybody    we 
asked  about  the  island  also 
knew    nothing    about    its 
location   or   geographical 
layout.  Being  intrigued  by 
the    mystery    surrounding 
the  island,  we  began  to  in- 
vestigate   the    possibility 
that  this  mfght  be  a  place 
for  our  first  expedition.  We 
inquired  further  about  how 
to  get  to   the  island   and 
where    it    was    actually 
located.   Travel    agencies 
were  no  help  and  we  had  to 
do    the    research    on    our 
own.    After    calling    nu- 
merous airlines,  we  finally 
found  a  way  to  get  down  to 
the  island,  which  involved 
the  use  of  three  separate 
flights.    After    careful 
research,  we  decided  that 
this   was    the   opportunity 
for    which    we    had    been 
searching.  Both  Stu  and  I 
could  afford  the  trip  to  the 
island,  and  we  would  be 
able  to  operate  without  the 
hassle  of  taking  along  an 
antenna  system  or  linear. 
The  problem  of  a  rig  was 
solved    by    using    my    FT- 
101B.  an  excellent  rig  for 
traveling.  We  decided  that 
this  was  the  place  to  try  our 
hand    at    being    DXpedi- 
tioners. 

Immediately  we  wrote 
to  the  owner  of  the  house 
to  inquire  about  the  avail- 
ability and  cost  of  rental 
and  the  procedure  for  ob- 
taining a  license.  We 
received  a  detailed  reply 
from  Doc  Beverstein 
VP2MZ,  who  was  delighted 
with  our  interest  in 
operating  from  the  island 


Mountain  view  on  the  way  to  P/ymouth^  showing  typical  scenery  of  the  island. 


and  arranged  for  us  to  stay 
in  the  house  from  Septem- 
ber 24,  1977,  to  October  2, 
1977.  The  rent  was  very  rea- 
sonable, well  below  that  of 
a  similar  stay  in  the  local 
hotel  Once  the  reserva- 
tions were  finalized,  we  set 
out  to  organize  our  forth- 


coming trip.  First,  a  letter 
was  sent  to  one  of  the  hams 
on  Montserrat  to  obtain  a 
license.  Here  we  were 
helped  by  Ruby  Bramble 
VP2MGB,  She  was  able  to 
apply  for  our  license  under 
standard  reciprocal  agree- 
ments,   and    would    be 


waiting   at   the  airport  to 
help  us  through  customs. 

We  set  out  from  Los 
Angeles  on  September  23, 
leaving  for  New  York  at 
10:00  pm  Los  Angeles  time. 
Upon  arrival  at  Kennedy 
International  Airport,  we 
had  to  wait  six  hours  for 


Operating  position.  Alan  Adler,  left,  and  Stuart  Sokolin,  right 


31 


MONTSERRAT 


BRITISH  WEST  INDIES 


OSO  WITH 


2  WAY  SSB-CW 


MONTH 


SEPT, 
OCT. 


DAY 


I    mm 


YEAR 


1977 


RST 


BAND 


3.5  -  7 
14-21  -28 


EQUIP:  FT101B-SB200-2EL  QUAD  -  SLOPER 


L 


OSL  VIA  W6EL 


73^3 
Stu  &  Al 


W6MJE:  Stuart  Sokolin 
WB5JPZ:  Alan  Adier 


our  connecting  flight  to 
Antigua.  After  arriving  in 
Antigua  on  a  very  hot  and 
humid  afternoon,  we  had 
to  wait  another  four  hours 
for  our  flight  to  Montser- 
rat.  On  our  last  flight,  we 
crowded  into  a  hot, 
steamy,  ancient  DC'3 
somewhat  reminiscent  of  a 
Mexican  bus  ride,  and  took 
off  (thankfully)  for  Mont- 


Sample  Montserrat  QSL  card 

serrat.  Fifteen  minutes 
later,  we  stumbled  off  the 
plane,  clutching  our  equip- 
ment, and  headed  for 
customs.  We  encountered 
little  difficulty  at  the 
customs  office  once  Ruby 
presented  the  officer  with 
our  Montserrat  amateur 
license. 

Our  route  to  the  house 
was  short  but  strewn  with 


holes,  ruts,  and  other 
obstacles  such  as  stray 
cows.  The  house  itself  was 
isolated  and  surrounded  by 
thick  undergrowth  topped 
with  beautiful  flowers, 
making  a  very  picturesque 
scene.  The  inside  of  the 
house  was  very  nice,  with  a 
separate  living  room,  kitch- 
enette, and  two  bedrooms. 
The  ham  station  was  in  one 


View  of  operating  area.  Equipment  shown:  Yaesu  fT-101B,  FV-101B,  and  Heath  SB-200 
linear. 


of  the  bedrooms,  which 
had  an  unobstructed  view 
of  the  ocean.  The  house 
was  on  a  hill  overlooking 

the  ocean,  and  the  trade 
winds  from  the  Caribbean 
kept  the  whole  house  cool. 
Both  Stu  and  1  were  over- 
whelmed  by  our  surround- 
ings. Seeing  it  all,  we  decid- 
ed that  life  as  a  DXer  might 
not  be  so  bad  after  alL 

Eager  to  set  up,  we  piled 
the  equipment  onto  a  table 

and  started  to  hook  up  the 
maze  of  wires  necessary 
for  our  operation.  Our 
equipment  consisted  of  my 
Yaesu  FT-101  B  transceiver, 
the  FV-IOIB  external  vfo, 
the  SB-200  linear  amplifier, 
and  our  portable  cassette 
recorder.  Our  antennas 
were  a  Hy-Cam  quad  on  a 
70-foot  tower  and  sloping 
dipoles  for  80  and  40 
meters.  We  had  a  first-rate 
island  setup. 

After  an  hour  of  setting 
up  equipment  and  fixing  the 
sloping  dipoles,  knocked 
over  by  a  recent  tropical 
storm,  we  were  ready  to 
make  our  appearance  on 
the  air.  In  order  to  generate 
maximum  exposure,  we 
started  on  20  meters  with 
the  quad  pointed  toward 
the  United  States.  The 
response  was  astounding. 
Within  seconds  of  starting 
operations,  we  had  a  tre- 
mendous pileup  of  state* 
side  hams.  To  be  on  the 
other  end  of  a  pileup  this 
size  was  the  most  exciting 
ham  radio  operation  that 
either  Stu  or  I  had  ever  ex- 
perienced. It  was  instant 
popularity  I  — and  quite  dif- 
ferent than  being  just 
another  California  station. 
Fortunately,  both  of  us  had 
planned,  months  in  ad- 
vance, the  techniques  we 
would  use  in  handling  large 
pileups,  and  soon  we  were 
handling  the  callers 
smoothly  and  quickly. 

In  order  to  assure 
everybody  an  equal 
chance  of  contacting  us, 
we  decided  to  keep  the  ex- 
changes to  a  minimum.  For 
example,  during  our  heavi- 


32 


est  pileups  we  would  only 
ask  for  callsign  and  signal 
report  We  would  not  stand 
by  for  anyone's  friends  at 
any  time,  so  as  to  be  fair  to 
all  hams,  and  we  would  not 
use  lists  of  any  kind  when 
dealing  with  the  pileups.  In 
order  to  give  areas  of 
poorer  propagation  a 
chance,  we  took  periodic 
standbys  to  listen  for  the 
weaker  stations.  The  over- 
all operating  manners  of 
the  stateside  stations  in 
pileups  were  quite  com- 
mendable. We  had  very  lit- 
tle deliberate  interference. 
The  hams  would  stand  by 
while  we  were  in  contact 
with  each  station,  and 
there  was  very  little  tail- 
ending.  When  we  asked  for 
standbys  to  the  areas  with 
poorer  propagation,  we  got 
good  cooperation  and  min- 
imum QRM.  Score  an  "ex- 
cellent" for  American 
amateurs  in  our  pileups. 

The  European  pileups 
were  much  harder  to  con- 
trol The  European  hams 
usually  did  not  stand  by 
while  we  contacted  a  sta- 
tion, and  the  interference 
was  much  greater.  These 
reactions  may  have  been  a 
result  of  the  language  bar- 
rier or  of  a  lack  of  ex- 
perience in  large  pileups. 
Still,  we  had  many  good 
contacts  into  the  European 
area. 

After  our  hectic  opening 

night  of  operation,  we 
finally  realized  that  we 
would  need  some  supplies 
if  we  were  going  to  survive 
a  week  on  the  island,  so  we 
set  out  on  a  mini-ex- 
pedition into  Plymouth, 
the  one  and  only  town  on 
the  island.  We  piled  into 
our  small  taxi  and  raced 
over  mountainous  roads 
past  beautiful  hills  and 
lush  green  valleys  to  the 
main  market.  Driving  in 
Montserrat  is  a  real  ex- 
perience in  survival  First, 
they  drive  on  the  opposite 
side  of  the  road,  as  in 
England.  Second,  the  roads 
are  narrow  and  rugged, 
with   lots  of   blind   curves 


This  is  a  view  of  the  town  square  in  Plymouth. 


and  thousand-foot  drop- 
offs. Third,  everyone  drives 
as  if  he  were  trying  to  win 
the  Monaco  Grand  Prix.  It's 
very  exciting  to  see  if  you 
can  make  it  to  town  and 
back  without  an  accident 
with  another  driver  or  with 
one  of  the  many  large  cows 
wandering  about.  Planning 
on  a  long  siege  at  the  radio, 
we  stockpiled  such  neces- 
sities as  cases  of  soft  drinks 
(at  an  amazingly  low  10<C 
per  bottle),  packs  of  candy 
bars,  eggs,  Heineken  beers, 
and  other  essential  foods 
needed  for  good  health. 
After  loading  the  car  with 
munchies,  we  decided  to 
walk  around  town  and  do 
some  sightseeing.  The 
village  was  very  quaint  and 
all  the  people  were  quite 
friendly-  Upon  our  return 
to  the  house,  we  decided  to 
see  if  there  was  any  activi- 
ty  yet  on  15  or  10  meters. 

The  pileups  on  20 
meters  seemed  like  a 
picnic  compared  to  the 
response  we  got  on  15 
meters.  We  were  inun- 
dated with  calls  from  all 
area.^  of  the  United 
States  as  well  as  Canada, 
and  with  an  equal 
number  of  calls  from  the 
European    stations.    We 


had  no  idea  where  to 
point  the  quad  first, 
since  wherever  we  aimed 
the  antenna  we  were  bar- 
raged  with  calls.  Stu  and 
I  took  turns  operating 
and  logging,  trying  to 
work  as  many  stations  as 
possible,  but  we  could 
not  handle  all  of  the 
response. 

We  finally  had  to  reluc- 
tantly leave  15  meters  to 
take  advantage  of  an 
opening  on  10  meters.  1 
think  half  of  the  world 
followed  us  to  10  meters. 
If  you  think  10  meters  is  a 
dead  band,  just  listen  to 
a  DX  station  give  one  CQ. 
I  believe  we  attracted 
every  ham  within  6,000 
miles.  We  were  working 
stations  at  the  rate  of 
three  per  minute  until  a 
sudden  power  failure  on 
the  island  took  us  off  the 
air.  After  the  power  had 
been  restored,  we  checked 
the  band  but  found 
that  the  propagation  had 
gone  down  considerably. 
Taking  a  quick  count  of 
our  brief  10  meter  debut, 
we  found  that  we  had 
contacted  over  200  sta- 
tions in  about  one  hour. 
We  had  also  contacted 
over   300    stations    on    15 


for   our   first    try   on    that 
band. 

Almost  collapsing  from 
exhaustion,  we  stumbled 
out  to  our  patio  overlook- 
ing the  Caribbean  and 
revived  our  spirits  with 
several  cold  drinks  from 
our  spacious,  well-stocked 
refrigerator.  The  life  of  a 
DXer  can  truly  be  grueling, 
we  thought,  as  we  relaxed 
on  the  front  porch,  enjoy- 
ing the  cool  trade  winds. 
Then,  gathering  courage, 
we  went  back  into  the 
shack  and  looked  at  the  log 
to  see  how  many  extra  QSL 
cards  we  would  have  to  fill 
out  for  our  moment  of 
glory.  Sobered  by  the 
thought  of  increased  writ- 
ing, we  decided  to  concen- 
trate on  our  two  expedition 
goals:  first,  to  obtain 
enough  countries  for 
DXCC;  second,  to  work  all 
states. 

Shunning  massive  pile- 
ups for  the  moment,  no 
matter  how  ego-gratifying, 
we  exerted  all  our  efforts 
toward  obtaining  a  max- 
imum country  total  We 
tried  40  meters  for  night- 
time DX,  but  found  the 
band  cluttered  by  broad- 
cast stations,  making  com- 
munications   impossible. 


33 


View  of  70-foot  tower  and  Hy^Ca/n  quad.  This  was  shot  on 
the  approach  to  the  house. 


Our  80  meter  nighttime 
operation  proved  much 
more  successful  and  we 
were  able  to  work  several 
of  the  European  countries. 
We  were  also  able  to  spend 
some  time  in  the  Russian 
portion  of  the  80  meter 
band,  working  many  of  the 
Russian  stations  which 
could  not  come  up  to  the 
regular  DX  area  of  the 
band.  During  the  daytime 
we  concentrated  primarily 
on  15  and  10  meters,  get- 
ting excellent  propagation 
into  the  Mideast  Asia,  and 
Oceania.  Longpath  to 
these  areas  was  also  quite 
effective  and  was  the  only 
way  we  were  able  to  con- 
tact stations  in  the  Asian 
zones. 

Being  able  to  operate  in 
the  foreign  band,  a  priv- 
ilege denied  to  us  in  the 
United  States,  helped  im- 
mensely in  contacting  new 
countries.  We  were  able  to 
avoid  much  of  the  QRM 
and  congestion  of  the 
American  band  and  were 
also  able  to  contact  sta- 
tions which  operate  pri- 
marily in  the  foreign  band. 
Split  operation  also  was 
made  more  efficient  by  our 
ability  to  listen  in  the  DX 
portion    of    the   American 


band  but  transmit  below 
the  band  edge.  Operating 
in  this  portion  of  the  band 
was  an  experience  we  real- 
ly miss,  now  that  we  are 
back  in  the  United  States. 

We  were  surprised  to 
find  that,  at  the  end,  when 
all  was  totalled,  we  had  not 
only  met  our  goal  of  100 
countries,  but  had  exceed- 
ed it  by  a  large  margin.  The 
total  country  count  fin- 
ished at  143  worked,  in- 
cluding all  continents.  We 
had  also  obtained  contacts 
with  alt  50  states,  the  most 
difficult  being  Alaska  and 
the  last  being  South 
Dakota.  Lest  anyone  think 
that  all  we  did  was  hunt  for 
specific  states  and  coun- 
tries, let  me  add  that  in  our 
eight  days  of  operation,  we 
contacted  more  than  3,300 
stations. 

After  eight  days  of 
operation,  we  reluctantly 
packed  for  our  trip  back  to 
California.  We  were  sad  to 
leave  the  island.  Though 
we  would  not  miss  the 
giant  bugs  that  attacked  us 
every  night,  nor  the  sugar 
ants  that  competed  with  us 
fof  food,  we  would  miss 
the  beautiful  weather,  the 
friendly  people,  the  help 


and  support  of  local  hams, 
and,  most  of  all,  the 
notoriety  of  being  a 
sought-after  DX  station. 
We  were  about  to  be 
transformed  back  from 
pileup-makers  into  pileup* 
seekers.  Stu  and  I  were 
ready  to  stay  indefinitely, 
but  we  had  no  choice 
because  the  house  no 
longer  belonged  to  us.  A 
new  occupant  was  eagerly 
waiting  for  us  to  leave  so 
that  he  could  taste  the  ac- 
tion that  we  had  enjoyed. 
The  weather  was  perfect  as 
we  left  for  Antigua  to  meet 
our  connecting  flight  back 
to  New  York, 

As  luck  would  have  it, 
we  arrived  in  Antigua  just 
in  time  to  watch  our  con- 
necting flight  take  off  for 
New  York,  which  started 
off  a  whole  chain  of  missed 
flights,  so  we  had  plenty  of 
time  to  sit  around  airports 
and  reflect  on  the  ex- 
periences of  our  first  ex- 
pedition. We  listened  quite 
a  bit  to  cassette  tapes  that 
we  made  of  our  operation 
and  enjoyed  reliving  the 
pileups.  Both  of  us  agreed 
that  it  was  well  worth  the 
trip  to  Montserrat  to  under- 
stand first-hand  the  work- 
ings of  a  DXpedition.  The 
experience  gained  on  the 
receiving  end  of  a  big 
pileup  is  invaluable.  It 
helps  one's  discipline  in 
operating  procedures,  and 
it  makes  one  appreciate 
the  difficult  time  that  DX 
stations  have  in  sorting  out 
the  numerous  calls  which 
seem  to  blend  into  one 
continuous  buzz. 

When  we  arrived  back  in 
Los  Angefes,  our  QSL 
manager,  Sheldon  Shallon 
W6EL,  presented  us  with 
the  first  of  a  number  of 
large  shopping  bags  full  of 
QSL  cards.  After  looking 
through  hundreds  of  cards 
sent  for  our  VP2M)  E  opera- 
tion, we  have  learned  what 
will  expedite  a  return  card 
and  what  will  stow  a  card 
down.  For  example,  it  is 
surprising  the  number  of 
people    who    send    cards 


with  local  time  indicated, 
instead  of  the  univeralty 
accepted  GMT.  A  DX  sta- 
tion, which  has  no  idea  of 
what  COST  or  MDST 
means,  will  simply  throw 
away  a  card  not  in  GMT, 
and  the  poor  ham  who 
worked  so  hard  in  that 
pileup  will  never  get  his 
card.  We've  received  cards 
which  have  been  an  hour  or 
more  off  of  the  correct 
time,  and  some  have  come 
through  with  no  time  in- 
dicated at  all.  Also,  people 
who  send  cards  to  a  QSL 
manager  with  no  SASE,  ex- 
pecting to  get  a  card  back 
immediately,  will  be  lucky 
to  get  a  card  back  through 
the  bureau  in  a  year,  if  at 
all.  Some  cards  came  with 
the  wrong  date,  and  with  a 
log  containing  3,300  con- 
tacts, it  is  impossible  to 
spend  time  looking  for  that 
contact.  Above  all,  make 
sure  that  every  DX  card 
you  send  is  in  GMT  with 
the  correct  date  and  time, 
and  is  legibly  written. 
Luckily,  however,  most  of 
the  cards  sent  to  us  were 
done  properly,  so  we  were 
able  to  locate  them  quick- 
ly in  the  log  and  send  them 
out  in  a  reasonable  period 
of  time. 

Both  Stu  and  I  have 
agreed  that  the  expense 
and  time  involved  in  an  ex- 
pedition such  as  ours  is 
well  worth  it,  and  we  feel 
that  any  ham  who  has  the 
opportunity  to  go  on  an  ex- 
pedition should  not  hes- 
itate One  need  not  go  to 
the  rarest  spots  of  the 
world  to  enjoy  the  excite- 
ment of  being  a  DX  station. 
We  were  neither  the  first 
nor  the  last  of  the  stations 
visiting  Montserrat,  but 
every  ham  who  has  been 
there  has  enjoyed  the  ex- 
citement of  being  on  the 
other  end  of  the  pileups 
and  there  is  plenty  of  ac- 
tion on  all  bands.  Other 
islands  could  offer  the 
same  opportunities.  DX- 
peditioning  is  a  unique  ex* 
perience  which  can  be  ap- 
preciated only  by  those 
who  have  tried  it  ■ 


34 


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35 


D.L.  Dobbs  K8NQN 
6612  Pleasant  Street 
Cmcinnati  OH  45227 


Close  Encounters 

•a 

the  eyes  of  Texans  are  upon  them 


Something  strange  was 
moving  up  there! 
Across  the  glittering  star 
fields  of  a  moonless  Texas 
night  it  crept,  a  small 
orange  light,  pulsating 
slightly  and  growing 
brighter.  Abruptly,  it 
changed  direction.  Red- 
dish now,  it  proceeded  at 
right  angles  to  its  former 
course,  away  from  the 
smudge  of  light  on  the 
horizon  that  marked  a  dis- 
tant city. 

A  flight  controller 
hunched  intently  over  his 
radarscope.  Its  eerie  glow 
illuminated  an  expression 
of  amazed  disbelief,  A 
silent  whistle  escaped  from 
his  pursed  lips.  An  80"^  turn 
at  16,000  mph  and  out  of 
range  already?  Involuntari- 
ly,  his  throat  muscles 
tensed  to  speak  to  the  pilot 
of  the  only  plane  on  the 
scope,  then  relaxed.  Who 
would  believe  him?  Prob- 
ably an  equipment 
malfunction,  he  thought. 
Yet  stories  told  by  old- 
timers,  stories  at  which  he 
had  scoffed,  began  to  filter 
into  his  mind. 

Much  lower  now,  the  ob- 
ject skimmed  slowly  over 
an  area  of  rough  terrain  A 
lone  car  probed  the  dark 


county  road  with  high 
beams,  Nearing  the  crest  of 
a  hilL  it  switched  to  low  as 
a  glare  showed  someone 
was  coming.  The  beer  net 
on  34/94  was  pleasant  com- 
pany. Suddenly  there  was 
only  dead  silence.  Worse 
yet,  the  engine  and 
headlights  had  quit  at  the 
same  moment! 

Too  busy  braking  to 
question  the  source,  the 
driver  was  thankful  for  the 
light  as  he  brought  the  car 
to  a  stop  on  the  berm.  But 
now  the  approaching  blaze 
looked  like  a  jet-propelled 
magnesium  flare.  )ust  as  it 
seemed  that  it  must  smash 
right  into  the  car,  it  was  up 
and  over  and  off  into  the 
sky  behind.  And  a  ham  sat 
quietly,  shaking  for  five 
minutes  before  realizing 
that  the  engine  was  run* 
ning.  the  headlights  were 
on,  and  the  repeater  was 
chattering  away  as  though 
nothing  had  happened. 
"What  was  thatV  was  still 
his  only  thought. 

At  that  moment,  not  far 
away,  as  it  had  all  day, 
every  day  for  months,  a 
unique  laboratory  waited 
to  answer  that  question 
Near  the  very  limit  of  their 
sensitivity,  recording  in- 
struments  deviated  slightly 


from  the  norms  of  their 
tireless  monitoring.  Inside 
a  low  building,  pale  by 
starlight  against  the  dark 
hillside,  electrons  surged 
through  microcircuitry.  A 
minicomputer  swiftly  ex- 
ecuted its  intricate  series 
of  commands.  An  alarm 
shrilled,  alerting  duty  per- 
sonnel. Quickly  all  posts 
were  manned,  and  the 
sophisticated  technology 
of  the  only  known  scien- 
tific facility  in  the  world 
dedicated  solely  to  UFO 
research  was  ready  for 
what  might  come. 

Still  adjusting  headsets, 
observers  manning  three 
phototheodolites  at  widely 
separated  locations  on  the 
40CI-acre  site  scanned  the 
stars  for  one  that  moved, 
waiting  for  instructions. 
They  were  not  long  in  com- 
ing, "Magnetic  anomaly, 
270  degrees,  increasing  in 
intensity.  Stand  by/'  Inside 
the  laboratory,  the  director 
studied  the  endless  white 
tongue  of  paper  extruding 
slowly  from  the  chart 
recorder.  Eight  fine  lines 
were  being  penned  on  it. 
measuring  the  output  of 
various  sensors.  Periodic 
blips  indicated  time  signals 
being  received  on  60  kHz 
from  WWVB.  Two  of  the 


channels  were  now  show- 
ing deviation  well  above 
their  baselines.  Attention 
shifted  expectantly  to  the 
color  video  terminal. 

From  high  atop  a  tower 
rising  into  the  darkness 
above  a  nearby  building, 
powerful  radar  pulses  were 
sweeping  a  12-mile  radius. 
For  several  rotations  there 
was  no  unusual  return. 
Xhen,  ''Radar  lock-onl''  As 
coordinates  of  the  UFO 
were  relayed  to  the  field 
observers,  excited  cries 
doubled  in  the  headsets. 
''Got  it!  Orange  lenticular 
object  moving  in  fast." 

All  three  photo- 
theodolites  were  now 
tracking  the  obiect.  Each 
operator  concentrated  on 
keeping  the  image  of  the 
UFO  centered  on  an  \l- 
luminated  spot  in  his  aim* 
ing  scope,  while  shaft  en- 
coders on  the  pan-and'tilt 
heads  of  the  telescopic 
cameras  were  feeding 
coordinates  into  the  com- 
puter. At  the  same  time 
photographic  evidence 
was  being  collected,  data 
sampled  from  each  of  the 
three  locations  every  few 
seconds  was  being  pro- 
cessed into  a  video  display. 
The  UFO's  path  was  seen 
superimposed  over  an  im- 


36 


Photo  A.  Laser  beam  made  visible  by  water  vapor  refraction  pierces  the  night  from  the  UFO  light-pulse  experiment  ap- 
paratus at  the  Laboratory  for  Instrumented  UFO  Research  near  Austin,  Texas.  Capable  of  transmitting  up  to  2.5  million 
bits  of  response-test  data  per  second,  this  red-tight  laser  device  can  also  be  used  to  measure  UFO  distance  and  test  the 
hypothesis  that  light  beams  may  be  bent  in  the  vicinity  of  some  UFOs. 


age  of  the  area  beoeath  it. 
Actual  distance  readings 
were  being  printed  out  for 
permanent  record. 

Busy  as  it  was,  though, 
the  computer  was  also  per- 
forming a  number  of  other 
vital  functions.  As  the 
vidicon  operator  focused 
on  the  approaching  UFO,  it 
measured  the  arc  subtend- 
ed by  the  image  and  com- 
puted the  size  of  the  ob- 
ject. It  also  computed  the 
visibility  radius  of  the  ob- 
ject, and  retrieved  the 
names  and  phone  numbers 
of  ARGUS  volunteers  who 
should  be  able  to  see  it 
Several  telephone  lines 
were  being  pulsed  with  the 
dual  tones  so  familiar  to 


autopatch  users,  and 
sleepy  voices  began 
answering  phones  shrilling 
on  bedside  stands  miles 
away.  As  each  answered, 
the  name  and  phone 
number  was  printed  out 
and  the  volunteer  heard, 
''This  is  an  Operation 
ARCUS  alert!  Please  do  as 
you  were  instructed/' 

Suddenly  wide  awake, 
the  observers  hastily 
pulled  on  clothes,  jammed 
feet  into  shoes,  and 
grabbed  binoculars  and 
cameras  on  the  run.  This 
night  they  were  not  to  be 
disappointed.  Here  was 
UFO  event-sharing  on  a 
silver  platter,  in  contrast  to 
the    ordeals    suffered    by 


our  friends   in   "Close   En- 
counters''   on    the    silver 

screen. 

Unlike  the  movie,  the 
scenario  we  have  imagined 
is  hardly  fantasy.  This 
laboratory  actually  exists. 
At  this  very  moment, 
whatever  the  time,  its 
equipment  is  scanning  the 
sky,  waiting  for  the  real 
thing  to  happen.  This  is 
where  history  may  be 
made— Project  Starlight 
International,  or  PSK 

In  the  rattlesnake- 
infested  hill  country  north- 
west of  Austin,  Texas,  ac- 
cessible only  by  four-wheel 
drive,  lies  the  40(>'acre  site 
of  the  Laboratory  for  In- 
strumented UFO  Research, 


a  facility  unique  in  the 
world.  At  this  remote  loca- 
tion, field  research  is  con- 
ducted for  Project  Starlight 
International,  a  research 
division  of  the  Association 
for  the  Understanding  of 
Man,  which  is  a  nonprofit 
educational  organization 
based  in  Austin.  RSI's  pur- 
pose? To  document  scien- 
tifically and  irrefutably  the 
existence  of  UFOs,  Ray 
Stanford,  founder  and 
managing  director,  is  an 
acknowledged  expert  in 
the  field  of  UFO  research. 
Author  of  Socorro  ''Saucer'' 
in  a  Pentagon  Pantry,  he 
conducted  a  fascinating 
and  well-documented  in- 
vestigation of  the  Socorro, 


37 


Photo  B.  PSrs  Operation  ARGUS  radar  and  radio-frequency  monitoring  laboratory.  With 
a  radius  of  12  miles,  this  radar  unit  will  provide  UFO  distance  data  for  Operation 
ARGUS,  a  computer-centered  tracking  system  of  highly  sophisticated  design  covering 
a  range  of  472  square  mites. 


New  Mexico,  landing  of 
April  24,  1964.  According 
to  Stanford,  there  is  no 
known  research  facility  in 
the  world  dedicated  to 
UFO  investigation  which 
even  approaches  the  so- 
phistication and  capability 
of  PSL 

This    high-powered    re- 


search effort  is  directed  by 
a  professional  astronomer. 
Dr.  Daniel  H.  Harris,  Ph.D., 
from  the  University  of 
Arizona.  Dr.  Harris,  some- 
thing  of  a  modern  pioneer, 
is  the  first  scientist  to  ac- 
cept a  full-time  paid  posi- 
tion in  UFO  research.  Right 
now,  final  touches  are  be- 


ing completed  on  the  most 
sophisticated  of  the  equip- 
ment, and  the  laboratory 
will  be  fully  operational. 
Much  of  the  equipment  is 
already  scanning  Texas 
skies  twenty-four  hours  a 
day.  And  a  most  impressive 
array  of  scientific  goodies 
it  is  indeed. 


What  are  the  prospects 
for  irrefutably  document- 
ing a  close  encounter? 
Much  better  than  you 
might  think,  as  witness  the 
photographs  showing  only 
one  of  several  UFOs 
observed  at  the  site.  But 
wouldn't  it  be  better  to  go 
to  the  UFOs  rather  than 
hope  they  appear  at  one 
location?  Actually,  that 
was  the  historical  ap- 
proach. During  the  green 
fireball  episode,  in  the 
late  '40s  and  early  '50s, 
teams  of  investigators  for 
Project  Twinkle  rushed 
from  one  area  to  another 
where  sightings  were  being 
reported.  Invariably,  they 
arrived  too  late  to  see 
anything.  The  UFOs,  it 
seems,  didn't  wait  around 
for  them,  PS  I  decided  that 
it  would  be  more  produc- 
tive to  establish  a  perma- 
nent laboratory  with 
sophisticated  equipment 
and  man  it  around  the 
clock,  seven  days  a  week. 
The  other  option  is  still 
open,  however.  A  vital  core 
of  instruments  can  be 
transported  on  short  notice 
by  four-wheel-drive  van  to 
any  location  where  it  might 
be  needed. 

Until  now,  most  UFO 
research  has  been  anec- 
dotal Witnesses  of  past 
events  could  be  inter- 
viewed and  second-  or 
third-hand  information 
could  be  correlated.  Infre- 
quently, a  fortuitous 
amateur  photograph, 
usually  of  very  poor  quali- 
ty, might  turn  up.  Or 
perhaps  a  bit  of  soil  from  a 
purported  landing  site 
could  be  secured  for 
analysis.  Immense  effort 
went  into  analyzing  and 
rehashing  data  of  this  kind, 
and  there  is  a  lot  of  it 
UFOCAT,  the  computer- 
ized files  associated  with 
the  Center  for  UFO 
Studies,  now  contains  over 
60,000  close  encounters; 
And  Ted  Bloecher  has  in- 
dexed over  1500  close  en- 
counters of  the  third  kind, 
in  which  contact  with  en- 
tities    was      reported. 


38 


However,  there  was  no  way 
to  study  UFOs  directly  and 
scientifically.  Like  the 
weather,  lots  of  people 
talked  about  UFOs,  but 
nobody  did  anything  about 
them  — except  for  the 
military,  which  was  busy 
trying  to  shoot  them  down. 

Scientific  voices  have 
cried  in  the  wilderness 
almost  from  the  beginning 
of  the  modern  UFO  era  in 
World  War  II,  urging 
serious  Investigation  Back 
in  1968,  the  House  Com* 
mittee  on  Science  and 
Astronautics  held  a  hearing 
on  UFOs.  Dr.  Carry  C. 
Henderson,  then  project 
leader  on  the  lunar  surface 
gravimeter/surveying 
system,  proposed  an  im- 
plemented ptan  to  acquire 
hard  facts  about  the  ex- 
istence and  nature  of 
UFOs  He  even  detailed  the 
instruments  which  should 
be  used  And  Carl  Sagan, 
an  astronomer  who  is  as 
outspoken  an  advocate  of 
the  well-inhabited  universe 
theory  as  he  is  a  skeptic 
about  UFOs,  has  said  that 
anyone  really  interested  in 
the  supposed  phenomenon 
should  use  high-quality  in- 
strumentation to  probe  its 
nature.  Finally,  someone  is 
doing  just  that! 

PS  I  is  equipped  to  study 
a  broad  range  of  physical 
effects  which  might  be 
associated  with  UFOs. 
Their  objective  is  to  gather 
a  maximum  range  of  hard 
data  and  to  disseminate 
this  information  quickly  to 
members  of  the  scientific 
community.  At  a  local 
level,  larger  numbers  of 
people,  probably  including 
some  hams,  will  be  able  to 
share  in  UFO  events  through 
Operation  ARGUS, 

The  Greeks,  as  usual, 
had  a  word  for  it.  Argus 
was  a  character  in  Greek 
mythology  who  had  eyes 
ail  over  his  body  to  make 
him  a  good  watchman.  At 
the  Laboratory  for  In- 
strumented UFO  Research, 
ARGUS  stands  for  Auto 
mated    Ringup    on    Ceo- 


located  UfO  Sightings, 
and  we  have  illustrated 
how  it  might  work  in  prac- 
tice. But  there  is  a  lot  more 
to  scientific  UFOIogy  than 
this, 

UFOs  have  been  re- 
ported to  cause  magnetic, 
radio-frequency,  elec- 
trostatic, and  gravitational 
effects,  as  well  as 
temperature  changes, 
barometric  disturbances, 
and  sounds.  PSi's  auto- 
matic recording  equip- 
ment therefore  includes 
three  magnetometers  and  a 
gravi meter,  as  well  as  a 
microbarometer,  an  elec- 
trometer, and  a  sky  camera 
activated  by  magnetom- 
eter deviations.  An  am- 
bient microphone  records 
voice  input  and  audio  ef- 
fects, white  a  highly-direc- 
tional microphone  can 
handle  distant  sounds.  The 
eight-channeL  sensor- 
activated  chart  recorder 
displays  low-frequency 
data  up  to  150  Hz  cor- 
related with  universal  time 
from  WWVB.  Radio- 
frequency  scanners  and 
recorders  also  incor- 
porating UTC  input  cover 
the  rest  of  the  spectrum- 

A    computer-interfaced 

magnetometer  system  has 
been  completed  which  will 
process  field-effect  data. 
Newly-designed  sensors 
with  60-Hz  filters  respond 
up  to  700  Hz  and  are 
oriented  in  three  dimen- 
sions. Thus  a  three- 
dimensional  video  model 
of  the  magnetic  field 
around  a  UFO  can  be 
displayed,  showing  each 
component  in  a  different 
color.  Pulsations  or 
changes  In  light  emitted  by 
a  UFO  can  be  monitored 
by  an  electronic  system 
utilizing  solid  state  sensors 
having  a  bandwidth  of  10 


Ray  Stanford,  Managing  Director 
Project  Starlight  International  (PSI) 
PO  Box  5310 
Austin  TX  78763 

Walter  Andrus,  Director 
Mutual  UFO  Network  (MUFOK) 
103  Oldtowne  Road 
SegulnTX  78155 

Dr.  J.  Allen  Hynek,  Director 
Center  for  UFO  Studies  (CUFOS) 
924  Chicago  Avenue 
Evanston  IL  60202 

WilMam  Spaulding,  Director 
Ground  Saucer  Watch  (GSW) 
13238  North  7th  Drive 
Phoenix  AZ  35029 

Dr.  Dennis  W.  Hauck^  Director 
International  UFO  Registry  (lUFOR) 
PO  Box  1004 
Hammond  \H  4e325 

James  Lorenzen,  Director 

Aerial  Phenomena  Research  Organization  (APRO) 

3910  East  Kleindale  Road 

Tucson  A2  65712 

Table  1.  Major  UFO  research  organizations. 


MHz. 

OZMA  and  CYCLOPS 
are  strange-sounding 
names  for  serious  projects 
funded  by  the  VS.  govern- 
ment to  search  for  in- 
telligent life  in  space. 
Possible  communications 
from  selected  stars  have 
been  monitored.  SETI, 
Search  for  Intelligent  Life, 
is  an  ongoing  NASA  project 
which  is  developing 
designs  for  a  very  large 
system  of  antennas  and 
computers  for  the  purpose 
of  contacting  extrater- 
restrial life.  Since  NASA 
scientists  are  convinced  of 
the  importance  of  such 
endeavors,  PSI  has  not 
neglected  this  aspect  of 
UFO  research.  Are  UFO  in- 
telligences, if  they  exist, 
capable  of  or  interested  in 
exchanging  intelligent 
communication?  To  an- 
swer   this    question,    a 


modulatabfe  Liconix  605M 
helium-neon  laser  has  been 
installed  which  can 
transmit  voice,  code,  or 
television  signals.  Any 
modulated  light  response 
which  a  UFO  might  make 
to  the  laser  signals  can  be 
detected  as  sound  or  as  a 
TV  image. 

Radio  transmissions 
other  than  noise  have  not 
been  reported  from  UFOs. 
Disruption  of  radio  trans- 
mission and  reception,  on 
the  other  hand,  is  frequent- 
ly  reported.  This  is  why 
laser  light  rather  than  rf 
was  chosen  for  a  com- 
munication experiment. 
According  to  many 
reports,  what  appear  to  be 
coherent  light  beams  of 
various  colors  have  been 
projected  from  UFOs.  And 
searchlight  beams  directed 
at  UFOs  have  been  seen  to 
bend  sharply,  due  perhaps 


NET 

DAY 

BAND 

MH2 

UTC 

EST 

CONTROL 

QTH 

Saturday 

40 

7.237 

1200 

08O0 

N1JS 

MA 

Saturday 

75 

3.975 

1300 

0900 

WA9ARG 

IL 

Table  2.  MUFON  amateur  radio  SSB  nets— weekly. 


39 


Photo  C.  An  early  prototype  program  dispiay  on  Operation  ARCUS's  color  video  ter- 
minal, sbowJng simulated  UFO  tracking  over  a  computerized  topographic  map.  Tracking 
and  laboratory  instrument  data  is  automatically  displayed  below  the  map^ 


to  some  field  effect  or 
variations  in  atmospherrc 
densitv-  These  are  phe- 
nomena worthy  of  in- 
vestigation for  which  the 
laser  equipment  could  be 
used.  In  addition,  the 
system  can  be  adapted  to 
determine  the  distance  of 
an  object  with  extreme  ac- 
curacy using  reflected 
laser  light. 

As  you  might  expect, 
photographic  documenta- 
tion is  an  important  aspect 
of  the  laboratory  program. 
UFOs  within  range  will 
find  that  they  are  captured 
on  35mm  moving  picture 
film  A  Super-8mm  sound 
movie  camera  with  a 
1-to-12  ratio  zoom  lens  is 
also  available.  From 
various  stations  at  the  site, 
three  automatically  syn- 
chronized 35mm  cameras, 
one  of  which  is  equipped 
with  a  diffraction  grating 
for  spectral  studies,  record 
any  UFO  event.  High- 
resolution,  close-up  im- 
ages of  objects  being 
tracked   can   be  obtained 


using  Schmidt-Cassegrain 
telescopes  of  2,110mm 
and      1,250mm      focal 

lengths,  as  well  as  a 
240mm  telephoto  lens  on 
the  35mm  movie  camera. 

UFOs  have  often  been 
reported  to  investigate 
new  or  unusual  light  pat- 
terns on  the  ground.  Some 
have  responded  to  lights 
flashed  or  directed  at 
them.  For  this  reason,  a 
light  pattern  response  ex- 
periment has  been  de- 
vised, although  it  is  rarely 
used,  A  hundred-foot  cir- 
cle consisting  of  ninety* 
one  150-Watt  spotlights 
contains  a  single  light  in  its 
center  Solid-state  circuitry 
and  a  microprocessor 
make  It  possible  to  se- 
quence the  fights  in  any 
desired  pattern,  or  even  to 
mimic  the  light  patterns  of 
a  UFO. 

K12XBJ,  the  only  known 
radar  facility  in  the  world 
dedicated  exclusively  to 
UFO  research,  was  li- 
censed by  the  FCC  on  )une 
8,1977.    Although    it    is 


planned  to  install  a  more 
effective  system  for  broad- 
range  sky  coverage  when 

funds  permit,  the  present 
Raytheon  Model  1700 
covers  a  12-mile  radius 
with  360-degree  rotation. 
Operating  on  9375  MHz, 
its  7.5  kW  pulses  can 
detect  reflective  objects 
up  to  20  degrees  above  the 
horizon. 

How  big  was  the  UFO? 
This  easy-sounding  ques- 
tion is  one  of  the  most  dif- 
ficult to  answer  accurately 
when  a  sighting  has  oc- 
curred. Was  the  object 
very  large  and  far  away,  or 
was  it  small  but  close  to 
the  observer?  Few  people 
run  around  with  optical 
range  finders  in  their 
pockets,  and  it  is  rare  that  a 
UFO  passes  in  front  of 
some  background  object 
which  can  provide  a 
distance  reference.  At 
PSl,  however,  Operation 
ARGUS  can  determine 
distance  electronically  by 
radar  Not  all  UFOs  reflect 
radar  signals,    apparently, 


but  this  poses  no  problem. 
Accurate  horizontal  and 
vertical  coordinate  data 
from  shaft-encoders  on  op- 
tical tracking  equipment 
can  be  triangulated  by  the 
computer  to  provide  ac- 
tual distance,  horizontal 
distance,  and  altitude.  If 
the  area  of  an  image  can 
be  measured,  the  size  of 
the  object  can  then  be 
computed  from  the 
distance  data. 

When  a  UFO  is  being 
tracked,  the  ARGUS  com- 
puter has  been  pro- 
grammed to  select  from  its 
memory  of  472  square 
miles  of  terrain  that  sector 
of  a  full-color  topographic 
map  over  which  it  deter- 
mines the  object  to  be 
passing.  The  path  of  the 
UFO  then  appears  on  the 
video  display  superim- 
posed over  the  image  of 
the  terrain.  Sequentially- 
tracked  positions  are  in- 
dicated by  successive  let- 
ters or  numbers.  The  entire 
episode,  correlated  against 
UTC,  can  be  retrieved  from 
computer  memory  for 
later  study.  Ground  ob- 
jects over  which  the  UFO 
passed  or  hovered  as  well 
as  possible  landing  sites 
will  thus  be  a  matter  of 
record.  They  can  be  ex- 
amined for  evidence  later, 
if  the  UFO  departs  before 
a  mobile  unit  can  reach 
the  site. 

We've  had  a  look  at  the 
CUS  of  Operation  ARGUS, 
which  is  primarily  techno- 
logical. The  AR,  auto- 
mated ringup,  deals  with 
people,  for  it  is  in  this  way 
that  local  volunteers  can 
get  involved  Ray  Stanford 
terms  this  aspect  of  the 
operation  "UFO  event- 
sharing."  Here  is  a  concept 
of  great  potential  to  us  as 
amateur  radio  operators, 
wherever  we  may  live.  As  a 
movie,  "Close  Encounters'' 
was  great  entertainment 
and  could  even  be  con- 
sidered educational  in 
some  respects.  But  fan- 
tasy aside,  what  is  the  ac- 
tual status  quo  with  regard 
to  UFO  knowledge  at  the 


40 


present  time? 

To  be  honest  about  it, 
there  is  a  great  diversity  of 
opinion    on    the    subject. 
UFOIogists,  many  of  whom 
have     been     investigating 
the  phenomenon  for  thirty 
years,  present  a  spectrum 
of  opinion.  Some  take  the 
position     that     little     or 
nothing  is  known  concern* 
ing  the  true  nature  of  the 
UFO.  Official   government 
interest  vanished  with  the 
dissolution     of     Project 
Bluebook  and  the  issue  of 
the     infamous    "Condon 
Report/'  which  as  much  as 
denied  their  existence.  On 
the  other  hand,  a  number 
of  authorities  believe  that 
the  reason  for  governmen- 
tal   disinterest,    including 
the  recent  refusal  of  NASA 
to  reopen  the  field  for  in- 
vestigation,   is    that    they 
already    know    all    about 
UFOs.   In  his  book,  Situa- 
tion Red:  The  UFO  Siege, 
Leonard  Stringfield  builds 
a    strong    circumstantial 
case  that  intact  spacecraft 
have  been  recovered  from 
crash   sites,    and   that   ex- 
traterrestrial    humanoids 
have  been  autopsied.  If  so, 
it    now    appears    unlikely 
that     military     authorities 
will     voluntarily     expose 
these  facts  to  public  view. 
However,  a  lawsuit  filed  by 
one  UFO  group  against  a 
government  agency  under 
the   Freedom   of    Informa- 
tion   Act    could    produce 
evidence  of  such  conceal- 
ment. 

Between  these  view* 
points,  one  finds  many 
theories  about  the  nature 
of  the  UFO.  Some 
UFOIogists  believe  that 
the  phenomena  may  be 
psychic  in  nature.  Others 
think  UFOs  are  a  mass 
neurosis,  a  psychological 
projection  from  the  race 
mind,  A  few  like  the  idea 
that  they  are  a  control 
mechanism,  designed  to  in- 
fluence human  evolution 
in  the  manner  we  saw 
dramatized  in  the  movie 
"2001."  Most  however, 
believe  the  evidence 
points    to    hardware   from 


Photo  D.  Second-generation  print  of  possible  UFO  which  hovered  for  nearly  10  nninutes 
beginning  at  8:58  pn}  on  December  10,  1975.  Tri-X  film,  5-$econd  exposure  with  300n}m 
f/4  lens.  Forty-eight  photos  were  obtained  during  this  event  which  occurred  prior  to  in- 

statlation  of  PSt's  njore  sophisticated  equipment 


Photo  £  Second-generation  print  of  same  object  as  Photo  D  moving  off  to  left  during 
8-second  exposure.  Note  strange  burst-like  effect  not  apparent  to  observers.  Approx- 
imately 9:09  pm,  Tri-X  film  with  300  mm  f/4  lens.  Typical  of  those  taken  by  the  PS  I  staff 
during  the  December  10,  1975,  event  the  photos  are  encouraging  but  not  considered 

definitive  concerning  the  nature  of  UFOs. 


outer  space,  vehicles  from 
some  distant  star  system 
which  operate  through 
space/time  in  a  manner  we 
cannot  yet  comprehend.  It 
IS  this  hardware  aspect  of 


UFOs  which  renders  them 
susceptible  to  instrumen- 
tal investigation.  We  may 
be  on  the  way  to  answering 
what  UFOs  are,  but  the 
questions    of   where    they 


are  from  and  why  they  are 
here  will  ultimately  have 
to  be  answered  as  well. 

Where,  then,  does  all 
this  leave  us,  as  interested 
citizens  who  want  to  know 


41 


the  truth?  And  what  can 
we  do  to  help,  or  to  be 
prepared  when  the  next 
"flap"  or  wave  of  activity 
once  more  fills  our  skfes 
With  something  strange? 

There  are  things  we  can 
all  do.  For  those  fortunate 
enough  to  live  in  the  vicini- 
ty of  Austin,  training  and 
participation  in  PSI  ac- 
tivities as  a  volunteer  might 
be  possible.  The  expense  of 
supporting  a  research  ef- 
fort such  as  this  suggests  a 
way  in  which  we  might  con- 
tribute. As  radio  amateurs, 
however,  we  have  unique 
qualifications  for  par- 
ticipating in  UFO  event- 
sharing  on  a  national  as 
well  as  a  local  level. 

We  can  keep  informed 
through  groups  which  cor- 
relate and  communicate 
information,  such  as  the 
Center  for  UFO  Studies. 
Dr.  |.  Allen  Hynek,  Chair- 
man of  CUFOS,  was 
technical    advisor   for   the 


production  of  "Close  En- 
counters." Much  of  the 
realism  of  this  film  can  be 
attributed  to  the  case  in- 
formation he  was  able  to 
provide.  We  can  also  join 
or  support  investigatory 
groups  such  as  MUFON 
or  GSW,  for  example, 
MUFON  amateur  radio 
nets  meet  weekly.  On 
Saturday  mornings  at  1 200 
UTC,  the  40  meter  section 
meets  on  7237  kHz,  and  the 
75  meter  section  meets  at 
1300    on    3975. 

Every  section  of  the 
country  has  investigators 
trained  by  some  organiza- 
tion to  investigate  UFO  in- 
cidents. They  are  often  in- 
terviewed by  the  media. 
Most  of  them  would  be 
more  than  happy  to  speak 
at  a  radio  club  meeting,  or 
to  know  that  local  hams 
are  ready  to  help  during  a 
local  UFO  flap.  Many  of 
them  need  education  in 
the  tremendous  capabil- 
ities amateur  radio  has  for 


tracking  and  reporting 
sightings  and  landings. 
Repeater  groups  in  par- 
ticular may  be  interested 
in  learning  who  to  call  and 
what  to  do  if  UFOs  appear 
in  their  area.  So  the  rela- 
tionship can  be  one  of 
mutual  benefit.  Getting 
qualified  investigators  to 
the  site  of  a  UFO  incident, 
while  it  is  still  in  progress  if 
at  all  possible,  is  the  key  to 
solving  the  mystery.  The 
government  agencies  can 
offer  no  help,  since  they 
have  officially  declined  to 
investigate  UFOs.  The 
police,  if  they  do  anything 
at  all,  generally  report  the 
incident  to  the  Center  for 
UFO  Studies  via  their 
hotline.  Ultimately,  news 
of  the  incident  may  filter 
down  from  there  to  the 
headquarters  of  one  of  the 
investigatory  groups  such 
as  MUFON.  A  local  in- 
vestigator is  finally  in- 
formed and  hopefully 
reaches  the  scene.  By  then, 
the  UFO  and  most  of  the 


evidence  is  long  gone. 
Wouldn't  it  be  much  more 
efficient  if  hams  knew  who 
to  contact  in  their  own 
area  to  report  an  en- 
counter? And  a  call  on  the 
2  meter  repeaters  in  any 
city  ought  to  furnish 
plenty  of  tracking  ob- 
servers or  witnesses  in  a 
hurry,  We  can't  all  have  a 
Project  Starlight  Interna- 
tional in  our  backyard,  but 
we  do  have  an  HT,  a 
mobile,  or  a  low-band  rig 
and  know  how  to  com- 
municate, We  also  have 
some  technical  training 
which  helps  in  describing  a 
UFO  and  its  effects.  Work- 
ing together,  we  can  solve 
the  UFO  problem. 

Current  UFO  activity  has 
recently  shifted  from 
South  America  to  Aus- 
tralia, The  lull  in  sightings 
in  the  U.S.  may  end  at  any 
time  UFOs,  the  eyes  of 
Texas  are  upon  you!  And 
we'll  be  keeping  ours  open, 
too.H 


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The  incomparable  System  3000A  starts  by  giving  you  a  receiver  with  absolutely  unequalled  performance.  The  five- 
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1^  Reader  Servics^sint  page  323. 


43 


The 
Schizophrenic  Triangle 


a  split-personality  radiator 


Freddy  Brown  WA4JTJ 
RED  h  Box  267 
ScoUsvUk  KY  42164 


If  you're  interested  rn  a 
multiband,  inexpensive, 
easily  built  wire  antenna 
system  with  DX  capabil- 
itieSi  then  here  it  is.  It's  in- 
expensive because  it  is 
made    of    available    ma- 


terials, such  as  wire  and 
small  variable  capacitors 
for  the  matching  section. 
This  also  contributes  to  the 
ease  of  construction.  Be- 
cause the  antenna  has  a 
dual  personality,  or  is  bi- 
banded,  1  call  it  ''schizo- 
phrenic." 

The  triangle  antenna  is  a 
single  loop  of  wire  fed  by  a 
gamma  match.  In  fact,  the 
loop  has  two  gamma 
matches  (one  for  each 
band  of  operation).  1  first 


SIDE  OF 


•- 2i 


INSULATOR 
IF  WOOD  11 
US£D 


fikfk 


WIHE 


1      L 


built  a  40m  triangle  as 
described  by  Byron  Self 
WB6UFW.1  I  operated  this 
antenna  for  about  a  year 
with  excellent  results.  A 
loop  is  very  wide-banded. 
In  fact,  by  use  of  the  gam- 
ma match,  the  swr  of  this 
antenna  never  exceeded 
1.3:1  at  the  band  edges. 
The  40  meter  foop  is  1 
wavelength  long  (140  ft.). 
After  realizing  this  closed 
antenna  loop  would  prob- 
ably   resonate   with   15 


u  eotTs 

to  HOLD 
CIM  TCtWER 


in  Itlm. 

wroao 


APEX 


IMSULATIWt 


TWIST  wme 


TV 


TWIST 
l*flftt 


canNCAs 


f^fr  1. 


¥lg,  2. 


44 


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This  new  MFJ-721  Super  Selector  CW/SSB  Filter  gives 

you  80  Hz  BW,  steep 

SSB  skirts,  noise 

2  watts  for 

speaker  plus  more. 


This  New  MFJ-721  Super  Sefector  CW/SSB 
Filter  gives  you  a  combinalrofi  of  pedormance 
and  features  available  only  frotn  Mf J:  *  Razor 
sharp  80  Hi  noiT- Tinging  CW  filler  •  Steep 
sktn  SSB  fiUef  •  Sefectabte  peak  and  trough 
noise  limiting  •  Plugs  in  pfione  pck  •  Two 
watts  lor  speaker    •  Simulated  stereo  reception 

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*  Auxiliary  2  watt  amplifier.  20  dB  gain. 

Ttie  CW  niter  gives  you  60  Wi  bandwidth 
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razor  sharp  selectivity,  Lets  yDu  hear  just  ofie 
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Bandwidlii  »s  selecUUt:  bypass^  80,  110. 
160.  180  Wi.  Response  is  60  d8  down  one 
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8  pcrie  acfive  IC  filter.  Low  Q  cascaded  stages 
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The  SSB  filter  dramaiical[y  improves  read 
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meter  {21  mHz)  excitation, 
I  proceeded  to  build  a  15m 
gamma  match  and  at- 
tach it  directly  to  the 
antenna.  The  same  results 
were  obtained  on  15 
meters  —  low  swr  and  very 
Wide  bandwidth  Adding 
the  second  gamma  match 
didn't  alter  the  perfor- 
mance of  the  original 
antenna. 

Shortly  afterwards,  t 
constructed  a  triangle  loop 
for  80  and  10  meter  opera- 
tion. I  simply  computed 
the  loop  length  for  the  mid- 
dle of  the  low  frequency 
band  by  using  the  formula: 
1000/f{MHz),  For  example, 
1000/3.6  =  278  ft.  This  is  1 
wavelength  for  80  meters 
and  8  wavelengths  for  10 
meters. 

Construction  Notes 

I'm  including  diagrams 
from  Byron's  article  to  aid 
in  the  construction  of  the 
wire  loop  and  gamma 
matches  These  are  Figs. 
2-4.  Fig.  1  shows  the 
''schizophrenic"  triangle 
with  gamma  matches  at- 
tached.  Solder  the  braid  of 
the  two  50-  or  75-Ohm 
coaxial  lines  to  the  center 
of  the  loop.  Solder  the 
center  conductor  of  the 
coax  to  one  side  of  the 
capacitor  and  the  gamma 
wire  to  the  other  side  of  the 
capacitor.  1  used  a  plastic 
freezer  box  to  house  the 
capacitor  and  applied 
silicone  rubber  sealant  to 
waterproof  the  holes  made 


L'  Bfl*Clc£TS 


If] 


I  IM  in.  ^OVE  BOlTS 


F/fr  3- 


by  the  exiting  wires.  I  used 
a  standard  close-spaced 
365  pF  broadcast  band 
capacitor,  which  has  not 
arced  yet  with  my  180  W 
transmitter. 

Final  Notes 

I  installed  both  loops  on 
my  SO-foot  tower  (Fig.  5L 
leaving  room  at  the  top  for 
TV,  2  meters,  and  maybe  a 
yagi  or  two  later  on.  The 
loops  should  be  kept  as 
close  to  equilateral  tri- 
angles as  possible.  Of 
course,  1  couldn't  do  this 
with  the  80  meter  loop  on 
my  60-foot  tower.  There- 
fore, 1  stretched  the 
horizontal  side  to  122  ft., 
and  each  slanting  leg  was 
78  ft  long.  This  put  the 
horizontal  leg  about  10  ft 
above  ground  and  the  apex 
at  the  top  of  my  tower.  The 
whole  loop  is  tilted  a  few 
degrees  off  vertical.  I 
would  expect  that  tilting 
the  triangle  would  result  in 
a  lower  angle  of  radiation. 


t 


' 1 

S 
4. 

.^                                                               rt 

DATA.  IN  TASLC  1 

GAMMA 

l&IVEH  LENGTH 

itf  SAI?DCN  HDS£  OR 

OTHEB  HCMT  «EIGHT 


\ 


SOLDER 


wO 


iMTc*<i«f6  «inc 


Fig.  4, 


One  last  point.  A  good 
antenna  switch  in  the 
shack  is  desirable  for  quick 
band  changes.! 


Reference 

1  Self.  **The  40'Meter  Trian- 
gle," QST.  Vol.  LX.  No.  5,  May. 
1976. 


FRONT  VtCW 


K  HE  K)<NTS 


Fig.  5. 


Loop  mformatlon 

Loop  length  for 
Bafid         middle  of  band 

80  277*9" 

40  141' 

20  70'5" 

15  472" 

to  35  8' 

6  1911" 

CombinatloftB     Loop  Length 
40m  and  15m         141' 

80m  and  10m        277'9" 


Gamma  data 
0        S 

96"    e" 

73'  4" 

35"  2" 

27"  1 .5" 

18"  t** 

Gamma  data 
same  as  atK>ve 

same  as  above 
Table  T* 


Capacitor  (pF) 

300 
200 
100 
75 

50 
30 
Resonant  frequencies 

40m— 7.100  MHz 
15m— 21.277  MHz 
80m— 3.6  MHz 
10m— 2a830  MHz 


46 


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p^  Read&f  Service—sm^  page  323. 


47 


Terry  Conboy  N6R  Y 
1231  Cresiview  Drive 
Satt  Cartas  CA  9407Q 


From  CW  to  Computers 


a  digital  modulation  primer 


You're  sitting  in  your 
easy  chair  discussing 
the  fine  points  of  raising 
begonias  with  the  bunch 
on  3914  when  something 
sounding  a  great  deal  like 
the  soundtrack  from  the 
"Texas  Chainsaw  Massa- 
cre" begins  to  put  a  decid- 
ed cramp  in  your  rag  chew- 
ing style.  The  group  is 
divided  on  whether  it  is 
SSTV.  Teletype^^,  fac- 
simife,  or  just  the  Russians 
at  it  again.  Whatever  it  is, 
you  decide,  it  is  at  least  50 
kHz  wide,  and  bound  to  be 
part  of  the  computer  con- 
spiracy incited  by  73  and 
its  I/O  section.  Bunch  of 
whippersnappers  and  their 
confounded  digital  mod- 
ulation! 

Digital    modulation    is 


nothing  new,  having  been 
started  by  Samuel  F.  B. 
Morse  and  others  quite 
some  time  ago  Lately, 
however,  it  has  grown  into 
something  quite  removed 
from  the  days  of  manually 
sent  Morse  code  and  of 
clanking,  noisy,  mechan- 
ical teleprinters.  In- 
tegrated circuits  have 
made  complicated  signal 
processing  simple,  or  at 
least  small,  and  computers 
are  now  available  at  a 
price  within  reasonable 
reach.  Lots  of  hams  like 
you  have  found  that  there 
is  a  great  amount  of  fun  in 
programming  and  playing 
with  microcomputers. 
After  the  initial  hardware 
debugging  and  the  game 
playing  which  follows,  you 


WAVCTER  1*2 


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JJENERATOfft 


ANALYZER 


AM  11^  ^ur 


BfPASS 


MAvrrSK  142 


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6£lCMAT0ft 


SPECTRLM 
AHMLrZEft 


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SOU ARE   «AVE 
GENEHftTCW 


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WAVETEK  142 

FLfNGTION 
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BOONTDN  aOZE 

FU-AU  SIGML 

CCNERATOA 


H-P  95358 
SPECTHUW 

AfiALTZE'^ 


PM  pPUT 


Fig*  1(^1  A1  measurement  setup.  Carrier  set  to  7  MHz.  (bl 
F1  measurement  setup.  Carrier  set  to  20  MHz.  fcj.  F2 
measurement  setup.  Carrier  set  to  55  MHz. 


remember  your  tempo- 
rarily-forgotten trans- 
ceiver and  begin  to  wonder 
how  you  can  hook  your 
new  toy  to  your  old  one. 
And  while  you're  wonder- 
ing that,  you  also  wonder 
what  the  output  of  your 
transmitter  will  be  and  how 
many  ''Sunday  Afternoon 
Begonia  Appreciation 
Nets"  wilt  be  doomed  by 
your  next  computerHdriven 
transmission 

The  FCC  stands  in  the 
way  of  complete  havoc, 
leaving  you  only  a  few 
loopholes  Presently,  they 
only  allow  two  types  of 
digital  modulation  for 
general  use.  One  is  good 
old  Morse  code,  and  the 
other  is  the  Baudot 
teleprinter  code*  The 
Baudot  code  is  a  five-bit 
code  with  definite  legal 
speed  restrictions;  Interna- 
tional Morse  is  not  limited 
in  speed  at  alL  Receipt  of 
Morse  by  ear  is  limited  to 
perhaps  100  or  so,  and 
there  is  a  group  of 
operators  who  specialize 
m  running  speeds  like  that 
for  their  own  fun  and 
amusement.  But  your  com- 
puter is  much  better 
equipped  to  send  and 
receive  Morse  than  the 
human  brain,  and  with  a 
small  amount  of  restraint 
on  your  part,  you  should  be 


able  to  run  Morse  much 
faster  than  100  wpm  and 
still  not  convince  the  FCC 
that  it  should  pass  new, 
even  more  restrictive  laws 
to  slow  you  down  once 
again.  To  help  you  gain  an 
appreciation  for  the  band- 
widths  of  the  signal  you 
may  create  when  you 
digitally  modulate  your 
transmitter,  I  have  made  a 
few  measurements  to  in- 
dicate what  you  might  ex- 
pect, both  for  speeds  and 
codes  now  permitted,  and 
some  that  might  be  al- 
lowed on  the  air. 

Types  of  Digital 
Modulation 

The  most  familiar  type 
of  digital  modulation  is 
probably  CW.  This  is  called 
continuous  wave,  because 
it  normally  isn't,  to  help 
the  confusion,  tt  is  better 
to  call  it  A1,  which  means 
on-off  amplitude  keying.  In 
case  you  haven't  checked 
lately,  it  is  still  being  used 
in  the  amateur  bands, 

A  modification  of  CW  is 
A2.  This  is  tone-modulated 
AM.  Usually  this  is  used  for 
code  practice  to  allow  the 
use  of  simple  receivers.  Its 
chief  identifying  character- 
istic is  its  inefficiency.  It 
uses  lots  of  transmitter 
power  without  paying  you 
back    in    signal*to-noise 


4d 


Fig.  2.  CW  signal  at  300  bps  with  steady  dots.  Scale:  1  kHz      Fig.  3.  CW  signal  at  300  bps  with  steady  dashes.  Scale:  1 
per  divison.  kHz  per  division- 


ratio.  Let's  let  this  one  die  a 
natural  death. 

Lots  of  hams  are  now  ac- 
tive on  TeletypeTM^  using 
FSK-  This  is  designated  F1, 
which  stands  for  telegra- 
phy by  frequency  shift  key- 
ing. The  key-down  or  mark- 
ing condition  is  noted  by 
one  frequency,  and  the 
key-up  or  spacing  condi- 
tion is  noted  by  another. 
Normal  practice  on  the  HF 
bands  is  to  use  a  shift,  or 
frequency  difference,  of 
170  Hz,  This  has  largely 
replaced  the  use  of  850-Hz 
shift  by  hams. 

As  in  the  case  of  CW, 
FSK  has  a  counterpart 
called  AFSK-FM,  which  is 
tone-modulated  FM, 
designated  F2.  Audio  tones 
are  shifted  by  the 
teleprinter  keyboard  (or 
computer)  output,  and 
these  tones  then  are  used 
to  modulate  a  standard  FM 
transmitter.  This  is  in 
widespread  use  on  many 
FM  repeaters  designed 
specifically  for  the  enjoy- 
ment of  RTTY  enthusiasts. 

Since  the  FCC  groups 
ihase  modulation  with  fre- 
quency modulation,  you 
Afould  probably  not  be 
itretching  things  too  much 
:o  suppose  that  you  could 
jse  PSK,  or  phase-shift  key- 
ng,  and  call  it  F1.  I  have 
lever  seen  any  amateur 
jse  of  PSK,  probably 
>ecause  of  the  difficulties 


in  demodulating  it.  It  may 
not  be  totally  suitable  for 
use  where  the  propagation 
medium  is  unstable,  caus* 
ing  multiple  paths  between 
two  locations  and  the  ac- 
companying fading  and 
rapid  phase  rotation. 

For  these  reasons,  I  will 
limit  myself  to  looking  at 
only  three  types  of  signals: 
CW,  FSK,  andAFSK-FM.  I'll 
show  you  what  present 
signals  probably  look  like, 
and  give  you  a  few  glimps- 
es into  what  the  future 
may  allow  on  the  amateur 
bands  to  enhance  your 
digital  modulation  plea- 
sure. 

Before  we  begin,  one 
idea  is  very  important. 
That  is  a  concept  called 
frequency  scaling.  What 
this  means  is  that  the  spec- 
tra of  digital  signals  will  be 
unchanged,  except  for  fre- 
quency scale,  if  you 
change  both  the  rate  of 
modulation  and  the  fre- 
quency shift,  if  any,  in  the 
same  porportion.  For  ex- 
ample, the  spectrum  of  a 
transmitter  with  FSK  of 
170-Hz  shift  and  45.45  bit 
per  second  modulation  will 
look  identical  to  that  from 
a  transmitter  with  17-kHz 
shift  and  4545  bit  per  sec- 
ond modulation,  except 
that  the  spectrum  will  be 
blown  up  in  the  frequency 
scale  by  100  times.  This 
trick  was  used  in  all  of  the 


examples  that  follow,  to 
allow  the  spectrum 
analyzer  to  be  swept  over 
wider  frequency  ranges  at 
higher  sweep  speeds,  using 
wider  detector  bandwidths 
than  would  have  been 
possible.  In  other  words,  I 
used  sleight-of-hand  to 
produce  the  spectrum 
photographs.  The  scaling 
factor  used  was  100,  ex- 
cept for  the  F2  spectra 
(scaled  by  10  times). 

Morse  Code 

International  Morse 
consists  of  dots,  dashes, 
and  three  different  lengths 
of  spaces.  Dashes  are  (sup- 
posed to  be)  exactly  three 
times  as  long  as  a  dot,  as  is 


the  space  between  letters. 
The  space  between  dots 
and  dashes  is  the  same 
length  as  a  dot,  and  space 
between  words  is  seven 
times  this  length.  Each  dot 
period  represents  one 
binary  digit  or  bit  of  infor- 
mation. 

In  order  to  produce  the 
spectrum  for  a  CW  signal, 
we  need  to  know  the  rela- 
tionship between  the 
speed  in  words  per  minute 
and  the  signaling  rate  in 
bits  per  second  (sometimes 
called  a  baud}.  The  FCC 
uses  a  standard  word  com- 
posed of  50  bits.*  There- 
fore, one  word  per  minute 
corresponds  to  50  bits  per 
minute  or  0.8333  bps. 


Fig.  4,  600-Hz  shift  FSK  Morse  at  300  bps  with  steady 
dots.  Scale:  T  kHz  per  division. 


49 


f4g.  5,  600-Hz  shift  FSK  Morse  at  300  bps  with  ran-      Fig.  6,   IJO-Hz  shift  FSK  at  45.45  bps  with  alternating 
dom  keying.  Scale:  1  kHz  per  division.  Is  and  Os.  Scale:  200  Hz  per  division. 


Somewhat  arbitrarily,  I 
have  chosen  a  signaling 
speed  of  300  bps,  which 
translates  to  360  wpm-  This 
seems  pretty  fast  but  we'll 
see  that  the  transmitted 
bandwidth  is  within  reason. 
And  because  of  the  scaling 
property,  you  can  get  a 
good  idea  what  bandwidth 
will  be  produced  by  slower 
speeds, 

The  FCC  rules  contain  an 
assortment  of  formulas  for 
calculating  necessary 
bandwidths.^  This  is  an  in- 
dication of  the  width  of  the 
signal  that  must  be 
transmitted  and  received 
in  order  to  obtain  a 
reasonable  replica  of  the 
desired   signal.    For  Al, 


BW=B  X  K,  where  B  is  the 
signaling  rate  in  bps  and  K 
is  an  empirical  constant  set 
equal  to  5  for  fading  cir- 
cuits [aren't  they  all?). 
From  this  we  get  a 
necessary  bandwidth  of 
1 500  Hz.  This  rs  admittedly 
an  approximation,  but  at 
least  it  gives  us  an  indica- 
tion that  we  won't  need  to 
cover  up  more  than  one 
"Begonia  Net"  if  we  in- 
advertently fire  up  our  rig 
on  the  wrong  frequency. 

Fig.  1(a)  shows  the 
measurement  setup  used 
to  generate  the  A1  spectra. 
The  function  generator 
produces  square  waves 
which  are  used  to  AM  the 
high    frequency   signal 


MMMi 


Fig.  7.  170-Hz  shift  FSK  at  45 A5  bps  with  random  bits. 
Scale:  200  Hz  per  division. 


generator.  The  spectrum 
analyzer  looks  directly  at 
the  output  of  the  signal 
generator  at  around  7MHz. 
For  dashes,  the  function 
generator  is  set  to  produce 
rectangular  waves  with  a 
3:1  duty  cycle  at  half  the 
frequency  used  for  dots. 

Fig.  2  shows  the  resulting 
spectrum  for  steady  dots 
and  Fig.  3,  for  steady 
dashes.  All  the  spectrum 
photographs  are  taken 
with  the  top  line  of  the 
graticule  indicating  the 
level  of  the  unmodulated 
carrier.  Vertical  calibration 
is  10  dB  per  division  for  all 
of  the  spectra.  These  two 
pictures  have  a  frequency 
scale  of  1  kHz  per  divison. 

Fig.  2  has  a  series  of  fine 
lines  at  multiples  of  the 
keying  rate  (150  Hz  -  300 
bps  for  dots).  Note  that 
every  other  line  is  at  a 
much  lower  level  than  the 
preceding  line.  This  is  a 
characteristic  of  the  spec- 
trum of  square  waves.  All 
of  the  even-order  har* 
monies  of  a  square  wave 
are  theoretically  zero. 
Because  of  slight  imperfec- 
tions in  the  symmetry  of 
modulation,  the  even- 
order  harmonics  do  ap- 
pear, but  still  at  a  reduced 
level.  It  is  worth  noting  that 
the  shape  of  both  side* 
bands  is  nearly  identical, 
and  is  in  fact  the  same 
shape  as  the  spectrum  of 


the  modulating  waveform. 
This  is  true  only  for 
amplitude-modulated 
signals,  and  definitely  not 
for  frequency-modulated 
ones. 

In  order  to  make  a  com- 
parison of  bandwidths,  we 
have  to  choose  some 
definition  of  bandwidth. 
The  FCC  specifies  allowed 
occupied  bandwidths  for 
all  commercial  services. 
This  is  defined  as  the  fre- 
quency bandwidth  which 
leaves  only  0,5%  of  the 
average  power  above  and 
0.5%  below  its  frequency 
limits.  This  is  easy  to 
calculate  by  adding  up  the 
power  in  the  carrier  and 
each  sideband,  until  99% 
of  the  total  power  is  ex- 
ceeded.^ For  signals  that 
do  not  have  identifiable 
discrete  sidebands,  a  good 
approximation  of  the  oc- 
cupied bandwidth  is  to 
take  the  bandwidth  at  the 
-27-dB  (0  2%  of  carrier 
power)  points  of  the  spec- 
trum. This  allows  a  quick 
estimate  of  the  transmitted 
signal  bandwidth,  without 
the  mess  of  numerically 
adding  up  all  of  the  areas 
under  the  spectral  curve. 

For  Fig.  2,  the  occupied 
bandwidth  is  1500  Hz, 
which  is  the  same  num- 
ber calculated  for  the 
necessary  bandwidth.  To 
simplify  comparison  of  the 
bandwidths    of    the   dif- 


50 


Fig.   8.   170-Hz  shift  FSK  at  74.2  bps   with  afternBting      Fig.  9,  170-Hz  shift  FSK  at  742  bps  with  random  bits. 
Is  and  Os.  Scale:  200  Hz  per  division.  Scale:  200  Hz  per  division. 


ferent  spectra.  Table  1 
shows  the  calculated  and 
measured  bandwidths  for 
all  of  the  measured  emis- 
sions. 

Fig,  3  has  twice  as  many 
lines  as  Fig.  2  since  the 
sending  rate  for  dashes  is 
exactly  half  that  for  dots. 
Every  fourth  line  of  dash 
spectrum  is  attenuated 
sharply.  This  is  due  to  the 
3:1  duty  cycle,  and  can  be 
proved  mathematically  if 
desired,  {As  they  say  in  the 
textbooks,  "It  can  be  easily 
shown  that. .  /') 

Frequency  Shift  Morse 

To  some,  the  thought  of 
Morse  code  sent  by  other 
than  on-off  keying  is  a  bit 
strange.  If  you  have  ever 
listened  to  the  Morse  iderv 
tifications  required  by  the 
FCC  for  RTTY  stations,  you 
can  see  that  it  is  sometimes 
difficult  to  copy  code 
when  sent  with  FSK. 
The  human  ear  is  well 
equipped  to  take  care  of 
the  problems  inherent  in 
receiving  Al,  but  a 
machine  is  not.  The  biggest 
problem  for  the  machine  is 
what  to  do  while  the  key  is 
up.  The  noise  present  dur* 
ing  this  period  ts  a  source 
of  confusion  to  most 
demodulators.  Many  de- 
tectors use  a  phase-locked 
receiving  technique,  so  the 
momentary  absence  of 
signal  means  a  loss  of  lock 


and  the  need  to  reacquire 
lock  at  the  beginning  of  the 
next  dot  or  dash. 

FSK  has  a  signal  present 
at  all  times  during  the 
transmission.  This  allows 
the  demodulator  to 
operate  without  interrup- 
tion. The  problem  is  now 
shifted  to  the  transmitter, 
which  has  to  produce  out- 
put on  a  100%  duty  cycle. 
However,  for  a  given  key- 
down  transmitter  power, 
an  FSK  system  with  proper 
shift  will  provide  a  3-dB  ad- 
vantage over  the  on-off 
keyed  system.  If  you  are 
really  worried  about  the 
power,  you  can  drop  the 
output  of  the  transmitter 
to  one-half  of  what  you 
were  running  on  CW  and 
still  be  in  good  shape  for 
transmission  errors. 

Since  we're  setting  up 
things  from  scratch,  we  are 
free  to  pick  the  shift  at  ran- 
dom, with  the  only  require- 
ment being  that  we  stay 
within  the  900  Hz  max- 
imum specified  by  the  FCC. 
Since  the  data  rate  is  300 
bps,  let's  pick  600  Hz  for 
the  shift.  This  would  allow 
us  to  use  audio  tones  of 
1200  Hz  and  1800  Hz. 
These  tones  are  centered 
nicely  in  the  audio  pass- 
band  of  a  norma!  SSB 
transmitter  and  have  the 
added  advantage  that  they 
are  all  multiples  of  300  Hz, 
which  would  make  it  easy 


to  generate  the  tones  with 
a  digital  frequency  divider 
synchronized  with  the 
oscillator  used  to  make  the 
code. 

The  formula  for  the 
necessary  bandwidth  for 
F1  is  given  by  the  FCC  as: 
BW  ^  2.6D  +  0.55B,  where 
D  is  the  peak  deviation 
(one-half  the  shift)  and  B  is 
the  signaling  rate  in  bps. 
For  the  case  at  hand,  BW 
=  945  Hz. 

The  measurement  setup 
for  FSK  signals  is  shown  in 
Fig.  1(b).  The  function 
generator  output  is  con- 
nected to  the  FM  input  of 
the  signal  generator,  either 
directly  or  via  the  ran- 
domizer. The  randomizer  is 


a  25-5tage  shift  register 
with  feedback  taps 
arranged  in  such  a  way  as 
to  generate  a  pseudo- 
random sequence  that  is 
2^^-^  long  (33,554,431 
bits)  before  the  pattern 
repeats.  The  randomizer 
makes  the  modulation 
more  realistic,  since  send- 
fng  continuous  dots 
doesn't  convey  much  infor- 
mation. Steady  dots  tend 
to  create  the  worst  case  for 
transmitted  bandwidth, 
too. 

Fig.  4  shows  the  spec- 
trum with  Morse  dots  at 
300  bps  with  600-Hz  shift. 
The  frequency  scale  is  the 
same  as  in  the  previous 
photos.    Except    for    the 


Fig,   10,   170-Hz  shift  FSK  at  110  bps  with  alternating 
Is  and  Os.  Scale:  200  Hz  per  division. 


51 


Fig.  n.  170-Hz  shift  FSK  at  110  bps  with  random  bits. 
Scale:  200  Hz  per  division. 


fcemiency  of  the  spectral 
lines  to  bunch  up  rn  the 

region  of  the  resting  mark 
and  space  frequencies, 
there  are  many  similarities 
between  the  AT  and  F1 
spectra.  The  occupied 
bandwidth  is  again  1500 
Hz,  which  is  almost  60% 
larger  than  the  necessary 
bandwidth  for  F1.  At  fre- 
quencies well  away  from 
the  carrier,  the  sideband 
levels  of  the  two  spectra 
are  nearly  identical. 

Fig.  5  shows  the  effect  of 
the  randomizer.  The 
discrete  spectral  lines  are 
gone,  and  are  replaced 
with  noise-like  spectral 
lobes.  It  is  interesting  that 
the  spacing  of  the  lobes  is 


the  same  as  the  major  lines 
in    the    spectrum    of    dot 

modulation.  The  band- 
width is  nearly  the  same  as 
with  dots,  but  the  level  of 
the  sidebands  several 
kilohertz  away  is  some- 
what  lower,  due  to  the  in- 
crease in  low-frequency 
components  in  the  bit 
stream  at  the  expense  of 
the  high-frequency  com- 
ponents, which  is  caused 
by  the  randomizing  pro- 
cess. 

FSK  and  Teleprinter  Codes 

The  most  common  use 
of  Fl  is  in  sending  text 
messages  between  me- 
chanical teleprinters.  The 
FCC  has  specified  that  the 


Fig.  12.  1200-Hz  shift  FSK  at  300  bps  with  alternating 
Is  and  Os.  Scats:  1  kHz  per  division. 


Fig.    13.    1200  Hz   shift   FSK  at  300  bps    with   random 
bits.  Scale:  1  kHz  per  division. 


code  to  be  in  general  use 
by  amateurs  is  the  5-bit 
Baudot  code,  named  after 
Emile  Baudot,  the  man 
who  pioneered  the  concept 
of  printing  telegraphy.  As 
used  by  amateurs,  it  is  a 
start-stop  or  asynchronous 
code,  since  it  does  not  re- 
quire an  external  syn- 
chronizing clock.  The 
equipment  is  synchronized 
on  a  character-by-char- 
acter  basis  by  using  a 
start  bit,  which  is  always  a 
space,  and  a  stop  pulse, 
which  is  always  a  mark,  to 
frame  the  character.  The 
start  bit  is  the  same  length 
as  each  of  the  five  informa- 
tion bits.  The  stop  pulse  in 
Baudot  is  normally  a 
minimum  of  1.42  times  as 
long  as  the  other  bits.  It 
can  be  as  long  as  desired, 
since  the  resting  condition 
between  characters  is  the 
marking  state.  For  com- 
puter use,  the  stop  pulse  is 
often  made  two  times  as 
long  as  the  others,  for  con- 
venience in  timing, 

A  second  code  author- 
ized by  the  FCC  for  limited 
use  (presently  on  OSCAR) 
is  called  ASCII.  That  stands 
for  the  American  Standard 
Code  for  Information  Inter- 
change. It  is  similar  in  con- 
cept to  the  Baudot  code, 
but  consists  of  a  start  bit, 
seven  information  bits,  a 
parity  bit  [for  error  check- 
ing), and  one  or  two  stop 


bits.  Normally,  two  stop 
bits  are  used  when  the 
signaling  rate  is  less  than 
300  bps,  and  one  is  used 
when  the  rate  is  greater 
than  300  bps.  Because  it 
has  seven  information  bits 
instead  of  five  as  in 
Baudot,  ASCII  has  a 
greater  number  of  possible 
code  combinations.  Many 
of  these  are  used  in  making 
upper  and  lower  case 
alphabetic  characters,  but 
there  are  also  a  number  of 
control  codes  not  found  in 
Baudot  at  all.  Because  of 
its  greater  versatility, 
ASCII  is  preferred  for  com- 
munications with  com- 
puters. 

Another  possible  code 
that  might  be  used  for 
computer  communications 
is  straight  binary  numbers. 
Transmitting  a  start  bit, 
eight  information  bits,  and 
a  stop  bit  would  allow 
sending  binary  numbers 
equivalent  to  decimal 
numbers  from  zero  to  255. 
Although  meaningless  to 
(normal)  humans,  the  com- 
puter uses  these  numbers 
for  machine  language  pro- 
grams and  data.  Alas,  the 
FCC  does  not  at  present 
permit  the  use  of  this  type 
of  data,  since  it  is  neither 
Baudot  nor  ASCII. 

You  may  be  curious 
about  the  number  of  words 
per  minute  that  are 
produced   by   a   given   bit 


52 


rate  using  Baudot  and 
ASCII.  If  we  assume  that  a 
word  consists  of  five 
characters  and  a  space  be- 
tween  words,  the  speed  in 
wpm  for  Baudot  is  1.3S 
times  the  signaling  rate. 
For  ASCII  with  two  stop 
bits,  it  is  0.91  times  the  bit 
rate,  and  for  ASCfl  with 
one  stop  bit,  it  is  equal  to 
the  bit  rate.  Compare  this 
to  1.2  times  the  bit  rate  for 
Morse.  It's  interesting  to 
note  that  Baudot  is  the 
most  efficient  of  the  codes 
mentioned,  in  terms  of 
words  per  bit 

Standard  amateur  prac- 
tice at  present  is  to  use  1 70- 

Hz  shift  on  FSK.  (The  origin 
of  this  number  is  probably 
as  obscure  as  that  for  the 
1.42-unit  stop  pulse!)  This 
has  almost  completely 
replaced  the  use  of  850-Hz 
shift  because  of  improved 
resistance  to  interference 
and  selective  fading  when 
using  170-Hz  shift.  Another 
shift  which  may  be  of 
future  interest  is  1200-Hz 
shift.  This  exceeds  present 
FCC  limits,  but  is  in  wide 
use  for  medium  speed 
telephone  data  sets  and  for 
cassette  tape  storage  of 
computer  programs  by 
hobbyists  using  the  "Kan- 
sas City  standard/'  The  KC 
standard  normally  is  used 
at  300  bps  and  has  been 
successfully  used  by  com- 
puter  amateurs  for  pro- 
gram exchange  via  long 
distance  telephone  as  weJI 
as  by  magnetic  tape.  It  is 
quite  possible  that  it  might 
be  usable  for  rf  transmis- 
sion as  well. 

The  speeds  used  for  the 
measurements  were  45.45 
bps  (60  wpm  Baudot),  74.2 
bps  (100  wpm  Baudot),  110 
bps  [100  wpm  ASCII),  and 
300  bps  (KC  standard). 
Calculated  and  measured 
bandwidths  are  given  in 
Table  1  The  measured 
spectra  are  shown  in  Figs.  6 
through  13.  The  first  of 
each  pair  of  photos 
represents  steady  alter- 
nating  Is  and  Os,  and  the 
second    photo   shows   the 


effect  of  a  pseudo-random 
bit  pattern.  The  photos  for 

the  narrow  shift  signals  are 
made  with  200  Hz  per  divi- 
sion on  the  frequency  scale 
to  allow  adequate  resolu- 
tion. The  1200-Hz  shift 
spectra  are  again  at  1  kH^: 
per  division. 

Notice  that,  generally, 
the  spectra  do  not  have 
any  lines  at  what  would  be 
the  resting  mark  or  space 
frequencies  This  will  only 
be  the  case  where  the 
signaling  rate  and  the  shift 
are  integer  multiples  (e.g., 
300:1200  or  300:600).  The 
point  of  this  is  that  you 
may  not  be  justified  in  say- 
ing that  an  FSK  signal  looks 
just  like  two  oscillators 
that  are  being  alternately 
switched  off  and  on.  That 
should  make  the  purists 
scratch  their  heads  a  bit. 

AFSK  On  FM 

Lastly,  we  will   look  at 
the    spectrum    that   you 
might    see    coming    forth 
from  the  antenna  connec- 
tor on  your  two  meter  rtg 
when  you  are  putting  FSK 
tones  into  the  microphone 
jack.    The    measurement 
setup  is  shown  in  Fig,  1(c). 
Only   two   cases   are   con- 
sidered: 170-Hz  shift  at 
45.45  bps  using  tones  of 
2125  Hz  and  2295  Hz,  and 
750-Hz  shift  at  45.45  bps 
using  tones  of  2125  Hz  and 
2975  Hz.  Peak  deviation  of 
the  rf  carrier  was  set  to  5 
kHz   peak   in  both  cases. 
The  use  of  850-Hz  shift  is 
still    common    on    VHF, 
probably  because  of  MARS 
influences.  On  VHF,  there 
is  probably  no  significant 
difference    between    the 
two  shifts  in  terms  of  per- 
formance, since  signal-to- 
noise  ratios  are   normally 
very   good,   and   errors   in 
transmission  are  rare. 

There  really  isn't  much 
difference  in  the  band- 
widths,  either,  as  Table  1 
shows  The  use  of  850  shift 
tones  carries  with  it  the 
disadvantage  that  the 
amplitudes  of  the  side- 
bands   at    some    distance 


Fig.  14-  170-Hz  sh/ft  AFSK-FM  at  45 A5  bps  with  alter- 
nating Is  and  Os,  Peak  FM  deviation  is  5  kHz.  Scale:  5 

kHz  per  division. 


from  the  carrier  do  not 
diminish  as  quickly  as 
those  for  the  170  shift 
tones. 

Bandwidth  Reduction 

The    measured    spectra 
are    laboratory    creations, 

but  they  should  reflect 
with  some  accuracy  how 
actual  transmitted  signals 
will  appear.  It  is  likely  that 
real  signals  may  be  slightly 
narrower  in  bandwidth 
than  those  shown.  Normal 
CW  transmitters  employ 
some  filtering  in  the  keying 
circuits  to  reduce  the 
tendency  to  generate  ''key 
clicks/'   These   clicks   are 


just  the  low  level 
sidebands  seen  in  the 
photos  at  some  distance 
from  the  carrier.  The  filter- 
ing in  the  transmitter 
makes  the  spectrum  of  the 
keying  waveform  fall  off 
much  more  rapidly  and 
reduces  interference  with 
nearby  stations. 

Amateurs  who  generate 
FSK  signals  by  putting 
audio  tones  into  SSB 
transmitters  may  restrict 
the  transmitted  bandwidth, 
also.  The  SSB  filter  in  the  if 
circuit  will  sharply  at- 
tenuate signals  which 
might  otherwise  extend 
beyond  the  edges  of  the 


Fig.  15.  850-Hz  shift  AFSK-FM  at  45A5  bps  with  alter- 
nating Is  and  Os.  Peak  FM  deviation  is  5  kHz.  Scale:  5 
kHz  per  division. 


53 


filter.  This  is  especially 
true  in  the  case  of  FSK 
Morse  or  future  use  of  Kan- 
sas City  standard  signals, 
since  their  bandwidths  ap* 
proach  that  of  the  SSB 
filter.  Intentional  filtering 
may  be  added  at  audio  f  re- 
quencies  between  the 
A  FSK  generator  and  the 
transmitter  input  to  ac* 
complish  the  same  result. 

Filters  which  reduce  the 
bandwidth  of  FSK  signals 
[or  any  FM  signal}  tend  to 
introduce  an  AM  compo- 


nent to  the  signal  If  the 
filtered  signal  then  passes 
through  a  transmitter  cir- 
cuit that  acts  to  partially 
limit  the  signal  such  as  an 
overdriven  output  stage, 
the  AM  component  may  be 
removed  and  the  band- 
width widened  once  again. 
What  this  means  is  that  if 
filters  are  added  to  inten- 
tionally reduce  the  trans- 
mitted bandwidth,  they 
will  not  be  completely  ef- 
fective unless  they  follow 
non-linear  circuits. 


m    * 


Someday, 

The  FCC  may  give  us  a 
chance  to  use  all  of  these 
emissions  to  improve  com- 
puter communications, 
and  communications  in 
general  as  well  Although 
a  phone  transmitter  may 
seem  simple  by  com- 
parison, when  the  signal-to- 
noise  ratio  is  poor,  digital 
systems  give  superior  per- 
formance. Mother  Bell  has 
already  made  the  decision 
to  convert  the  vast 
majority  of  her  switching 


Nee. 

Occ. 

-27  dB 

Fig- 

Bps 

Shift,  Hz 

BW,  Hz 

BW,  Hz 

BW.  Hz 

2 

300 

0 

1500 

1500 

900 

3 

300 

0 

1500 

750 

900 

4 

300 

600 

945 

1500 

1500 

5 

300 

600 

945 

— 

1400 

6 

45.45 

170 

246 

318 

318 

7 

45.45 

170 

246 

— 

315 

8 

74.2 

170 

262 

371 

371 

9 

74.2 

170 

262 

— 

380 

10 

110 

170 

282 

330 

440 

11 

110 

170 

282 

— 

360 

12 

300 

120O 

1725 

2100 

2100 

13 

300 

1200 

1725 

- 

2200 

14 

45.45 

170 

14590 

13770 

17000 

15 

45.45 

850 

15590 

17000 

17850 

Table  1.  Bandwidth  summary. 


systems  to  pulse  code 
modulation  to  take  advan- 
tage of  the  ease  of  routing 
long-distance  conversa- 
tions with  logic  ICs  instead 
of  relays.  PCM  requires  a 
rather  large  bandwidth,  but 
makes  sense  in  the  upper 
UHF  region  through  the  op- 
tical wavelengths. 

The  ''Begonia  Net"  may 
not  soon  be  running  PCM 
in  place  of  lower  sideband, 
but  a  "Worked  All  8080s 
Award''  for  computer- 
equipped  hams  running 
CW  at  360  wpm  may  not  be 
far  off.H 

References 

1.  Lizee,  Ga&pard/"Speed  Stan* 
dards  for  International  Morse 
Code;^  Ham  Radio,  April,  1973, 
p.  68. 

2.  FCC  Rules  and  Regulations, 
Volume  2,  Subpart  C,  Section 
2.202. 

3.  GuenUler,  Ron,  "RTTY  Signal 
Bandwidth/'  RTTY  Journal, 
April,  1977,  p.  5, 

4.  ITT  Reference  Data  for  Radio 
Engineers^  p*  23-8,  Indianapo- 
lis, Howard  W.  Sams,  1975. 


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MESSAGE  TO  ALL . . . 


In  this  Christmas  season,  when  our  thoughiii  and  desires  are  turned  toward  material 
possessions,  we  offer,  Tor  your  consideration,  one  possession  of  lasting  value 
which  wili  truly  satisfy  an  inner  hunger. 

There  is  an  area  of  human  desire  that  can  only  be  satisfied  by  our  Heavenly  Father. 
We  can  attempt  to  satisfy  this  area  in  our  life  with  material  possessions »  but  it 
will  not  be  successful. 

The  Bible  tells  us  in  Psalms  57:4,  5;  "Delight  thyself  also  in  the  lord,  and  He 
shall  give  thee  the  desires  of  thine  heart.   Commit  thy  way  unto  the  Lord;  trust 
also  in  Hinst  sfKi  He  shall  briny  it  to  pass",  (KJV) 

Jesus  telis  us  in  the  Gospel  oF  John  that  He  is  the  way,  the  truth  and  the  life* 
If  we  believe  this,  follow  His  teachings  and  obey  His  coinmands,  we  may  ask  any 
request  of  Him  and  it  will  be  granted.   He  has  told  us  this  so  we  will  be  filled 
with  His  joy* 

His  way  for  our  life  will  fulfill  our  desires  and  solve  the  complex  and  confusing 
problems  of  this  life.   Jesus  said,  *'l  am  come  that  they  might  have  life#  and  that 
they  might  have  it  more  abundantly"*  John  10:10b  (KJV) 

God*s  plan  for  our  life  makes  us  a  complete  person  through  Jesus  Christ,   Please 
accept  His  love  and  have  a  blessed  Christ -centered  holiday  season. 


^  ^        RD  1  •  BOX  I85A  -  FRANKUN,  PA  16323 


^^M7t 


64 


\^  Reader  Service— see  psge  323. 


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COMMUNICATIONS  ^vi. 

915  N.  MAIN  ST.  JAMESTOWN  NEW  YORK  14701 

(71 6]  664-6345 


1*^  Header  Se/Vfce—see  page  323. 


56 


A  28C  Touchtone 


TM 


Mod 


something  for  [almost]  nothing 


David  J,  Brown  W9CGI 
RR  5,  Box  S9 
Nobiesviiie  IN  46060 


Repeater    owners,    re- 
mote   control    users. 
and   touchtoneTM  fai^s  in 

general— take  note!  This 
article  will  show  you  how 
to  get  24  decoded  func- 
tions (on  IS-key  TT  pad 
systems  with  A,  B,  C,  D)  or 
19  decoded  functions  (on 
1 2-kev  TT  pad  systems  with 
10  numbers,  the  *,  and  the 
#  only)  from  your  present 
16-  or  12-function  systems 
—  and  very  inexpensively. 
Depending  on  how  you 
decode  your  TT  tones  at 
the  receiving  end,  this 
modification  will  cost  you 
from  28?  to  76?  at  January, 
1978,  prices  on  TTL  logic 
(source  is  Poly  Paks*) 
Since  nearly  all  the  up  and 
working  systems  use  567 
tone  decoders  that  output 


56 


a  low  for  a  decoded  number 
(as  do  many  other  systems), 
and  these  lows  are  inverted 
before  the  low  group/high 
group  ANDing  to  get  a  sin- 
gle function,  I  will  concen- 
trate on  those  systems. 
Mine  is  shown  in  Fig.  1.  By 
just  comparing  it  to  yours, 
you  can  tell  what  may  be 
missing  on  yours.  1  have 
duplicated  my  TT  decoder 
section  for  clarity.  It  has 
nothing  to  do  with  whether 
you  can  get  the  extra  7  or  8 
functions,  and  is  shown  on- 
ly because  [  use  an  extra 
enable/disable  function 
line  and  three  input  gates 
on  TT  decoding.  This  is  not 
required,  so,  if  your  system 
uses  the  more  common 
two-input  gating  system, 
don't  fret. 

Since  I  already  had  all  of 
the  ICs  with  letter  designa- 
tions, and  half  of  IC-D 
wasn't  being  used,  I  only 
had   to  use  unused  func- 


tions of  ICs  already  there, 
except  for  adding  ICs  1  and 
2.  While  we  are  on  ICs  1 
and  2,  I  will  add  that  they 
may  be  7400s  if  you  want 
TTL-compatible  outputs 
for  your  extra  added  func- 
tions. If  you  want  uncom- 
mitted outputs  to  run  out- 
side-world devices  (small 
low-voltage/current   relays, 

etc.),  as  I  did,  you  use  7403s 
with  no  wiring  changes  on 
the  sockets.  This  is  nice  if 
you  later  change  your 
mind  or  want  four  of  one 
and  four  of  the  other. 

To  explain  the  system, 
first  let  me  cover  normal 
TT  decoding.  For  any  valid 
TT  tones,  you  will  have  one 
decoded  low  group  and 
one  decoded  high  group  as 
TTL  lows  on  the  inverter 
(ICs  A  and  B)  input  lines. 
Depending  on  the  func- 
tion, this  will  be  a  high  on 
one  of  the  LI  to  L4  points, 
and  a  high  on  one  of  the  HI 


to  H4  points.  This  will  2/3 
enable  one  of  the  3-input 
gates  in  IC-E  through  ).  The 
common  line  you  see  con- 
nected to  all  of  the  gates  in 
IC-E  through  J  must  go  high 
to  finish  the  decode  en- 
abling. Example:  If  this  line 
is  high  and  we  receive  a 
low  group  697  Hz  tone  and 
a  1209  Hz  high  group  tone, 
LI  and  HI  will  be  high,  and 
the  number  1  will  be  de- 
coded [TT). 

As  for  how  that  common 
line  gets  high,  please  take 
the  above  example  again. 
A  low  on  IC-A-1,  causing  a 
high  on  IC-A-2  and  LI,  half 
enables  IC-1-1.  Since  this  is 
a  TT  tone  we  are  receiving, 
there  is  also  a  high  group 
tone  {1 209  Hz),  and,  if  there 
is  a  high  group  tone  (as 
there  is  for  any  valid  TT 
tone),  IC-C'8  is  high,  Invert 
this  through  lC-B-11  to  10 
to  HTT  for  a  low.  That  tow 
is  applied  to  IC-D-10  and 


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Fig.  1.  *Note:  ICs  1  and  2  can  be  7400  for  TTL  outputs  or  7403  for  uncommitted  collector  outputs. 


disables  IC-D-8  (high), 
through  IC-A'1 3  to  1 2  (I owl 
and  disables  all  the  single 
low  tone  group  decoders, 
IGI.  When  a  low  group 
tone  is  also  present  (as  with 
any  valid  TT  tone),  follow- 
ing IC-C-6  (high),  through 
IC-A-11  to  10 (low)  and  LIT, 
to  IC-D-1 3  disables  lOD^II 
(high),  through  IC-A-13  to 
12  to  all  of  IC-2,  disabling 
all  the  high  tone  group 
single  tone  decoders. 

Going  back  to  IC-C-6  and 
IC-C-e  (both  high  on  TT), 
these  highs  go  to  tC-D-1 
and  IC-D-2  to  form  a  low  at 
[GD-3.  The  last  gate  in  IC- 
D  is  wired  as  an  inverter 
and  causes  the  low  at  IC- 
D-3  to  be  a  high  at  IC-D-6. 
This  1/3  enables  all  the  TT 
decoders  and  says  a  valid  2 
tone  TT  signal  is  present. 
Since  we  chose  the  exam- 
ple of  697  Hz  and  1209  Hz 
(TT  function  1),  the  low 
group  (697  Hz)  fully  decod- 
ed as  a  high  goes  to  1/3  of  a 
gate  in  IC-E,  and  the  high 


group  (1209  Hz)  fully  de- 
coded as  a  high  goes  to 
another  1/3  of  the  same 
gate  in  IC-E.  Along  with  the 
TT  enable  high,  this  causes 
the  function  1  to  go  low 
and  the  TT  number  1  is 
decoded. 

If  you  follow  the  aster- 
isk in  Fig.  1,  I  have  shown 
also  the  single  tone  (770 
Hz)  decoding,  All  the  little 
L  and  H  characters  indicate 
low  and  high,  respectively, 
and  refer  to  gate  or  line 
status  for  this  one  par- 
ticular (770  Hz)  example. 
You  will  see  that,  with  the 
high  group  tone  of  any  kind 
missing,  tC-C-8  is  low,  dis- 
abling alt  the  TT  decoders 
via  IC-D-2  (low)  and  IC-D-3 
(high),  through  inverter  IC- 
D4  and  5  to  6  (low!  The 
missing  high  group  tone 
and  IC-C-fi  (low),  through 
inverter  IC-B-11  to  10  (high) 
and  HTT,  causes  IC*D  10  to 
be  high.  Since  there  is  a  low 
group  tone  (770  Hz),  lC-C-6 
is    high    and    enables    the 


other  half  of  IC-D-9  and  10 
to  8  and  makes  lC-D-8  tow. 
Inverted  through  IC-A-13 
to  12  (high),  all  the  low  sin- 
gle-tone decoders  are  1/2 
enabled.  Since  the  low- 
group-only  tone  is  770  Hz, 
IC-A-3  is  low  and  IC*A'4  is 
high  and  enables  the  other 
half  of  IC-1-4.  This  causes  a 
low  at  IC-1-6  and  a  fully 
decoded  770  Hz  function 
at  IC-1-6. 

I  confess  to  a  bit  of  foxy 
maneuvering  at  this  point. 
This  whole  business  (seeing 
as  all  I  had  to  add  were  ICs 
1  and  2]  was  done  original- 
ly to  detect  the  indepen- 
dent high  and  low  tone 
group  decodings  and  only 
light  LED  indicators.  It  was 
not  until  the  unit  was  all 
built  and  running  that  I 
decided  why  not  use  these 
extra  functions  to  do  things 
on  the  receiving  end  with  a 
bit  of  extra  circuitry  to 
define  single  tone  versus 
TT  pair  tones.  It  greatly 
reduces    the    necessary 


hardware  to  handle  station 
keeping  such  as  changing 
from  tight  to  loose  squelch 
on  the  repeater  receiver 
and  resetting  the  time-out 
timer  if  someone  over-talks 
it  That  way,  none  of  the 
original  12  or  16  functions 
are  used  up  or  confused, 
like  on  an  autopatch  re- 
peater, These  can  be  used 
as  completely  separate 
functions. 

While  I  am  covering  bits 
of  honesty,  I  should  men- 
tion how  this  whole  thing 
works  from  the  sending 
end.  Following  Fig.  2 
should  help.  This  is  nothing 
more  than  the  face  of  a  TT 
pad.  As  long  as  you  push 
single  buttons,  you  get 
dual  TT  tones  correspond- 
ing to  the  key  pressed.  If 
you  push  any  adjacent  parr 
of  keys  on  a  standard  TT 
pad,  you  get  only  the  single 
tone  for  that  row  or  col- 
umn. Following  Fig.  2,  if 
any  pair  of  the  column 
keys  such  as  (1-4),  (4-7),  or 


57 


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f4t  Hi 
ONLTT 


f /g.  2. 


(7-*)  are  pushed,  that  col- 
umri  tone  results.  Columns 
produce  the  high  tones,  go- 
ing from  lowest  to  highest 
as  you  go  left  to  right  [i.e., 
left  column  =  1209  Hz 
through  right  column  (if 
present  A,  B,  C,  D)  =  1633 
Hz].  Any  row  pair  that  is 
pushed  produces  a  low 
group  tone,  going  lowest  to 
highest  as  you  go  top  to 
bottom  (i.e.,  top  row  —  697 
Hz  through  the  bottom  row 
=  941  Hz).  A  row  pair  ex- 
ample to  get  941  Hz  would 
be  C*-0),  t04L  or  t#-D),  Any 
pair  example  in  a  row  or 
pair  in  a  column  seems  to 
work,  but  adjacent  pair 
keys  are  easier  to  hit  and 
better  insurance  that  you 
have  both  keys  down. 

As   for   rules    to  follow 

when  sending,  be  sure  to 
hit  and  depress  both  keys 
of  a  pair  at  the  same  time 
and  release  at  the  same 
time.  If  you  hit  one  key  and 
then  add  another,  you  will 
get  a  TT  tone  and  single 
tone  sequence  not  desired 
in  this  decoder.  Changing 
the  decoding  further,  you 
could  put  this  to  advan- 
tage in  two-number  sys- 
tems. The  Indianapolis 
16/76  machine  has  a  very 
interesting  and  helpful 
system  function  that  is  TT- 
tone  controlled.  By  push- 
ing the  series  71  through 
79  Cexcluding  77)  TT 
numbers,  a  tape  is  played 
back  to  you  giving  you  one 
track  of  8  possible  tracks 
worth  of  prerecorded 
messages.  As  you  might 
guess,   the  number  7  fol- 


lowed by  6  (76)  gives  you 

all  the  information  about 
the  16/76  machine  opera- 
tions and  format.  Adding 
more  housekeeping  func- 
tions could  be  done  by 
adding  another  full  two- 
number  set  decoder  group 
(quite  a  few  ICs)  and  using 
the  10s  or  80s,  etc., 
numbers  just  as  the  70s  are 
now  used  for  the  tapes. 
Just  as  easily,  and  for  much 
less  expense,  at  least  7 
more  functions  could  be 
added  by  my  method  with 
no  changes  made  out  in  the 
field  by  the  sending  sta- 
tions- 

The  sequence  7-6  would 
still  be  a  decoded  7-6  and 
activate  the  tape  that  ex- 
plains 16/76.  Using  the  7-4 
for  a  single  tone  example, 
since  they  are  a  column 
pair,  and  7-6  is  neither  a 
column  nor  a  row  pair,  if 
7-4  is  pushed  in  sequence 
form,  the  74  tape  would 
still  play.  If  the  7-4  were 
pushed  together,  however, 
a  single  tone  of  1209  Hz 
(left  column)  would  result, 
causing  a  low  decoded  at 
HT*1  in  Fig,  1 ,  This  could  be 
used  for  whatever  you  like. 

Since  t  have  used  our 
16/76  machine  which  Indy 
amateurs  are  quite  proud 
of  for  an  example,  please 
allow  me  to  issue  an  invita- 
tion and  a  couple  of  words 
of  warning/advice/help. 
Should  you  pass  through 
our  town  (or  within  about  a 
25-mile  range),  and  want  to 
dial  up  the  tapes,  you  must 
observe  two  simple  roles. 
The  first  is:  The  dial-up  on- 


ly works  if  preceded  im- 
mediately (without  drop- 
ping carrier  between}  by 
audio.  A  valid  and  ap- 
preciated by  us  (and  the 
FCC)  way  of  doing  this  is: 
Using  my  call  only  as  an  ex- 
ample—"This  is  W9CG1 
accessing  tapes/'  Send  first 
TT  (7)  for  about  1  second, 
then  send  second  TT  (any 
but  0  or  7)  for  about  1  sec- 
ond, then  drop  carrier.  To 
allow  for  any  of  the 
emergency-type  break-ins 
that  might  occur,  the  tape 
was  done  so  it  can  be 
"talked  over/'  i.e.,  if 
another  station  has  emer- 
gency traffic,  and  a  tape  is 
playing,  he  has  only  to  key 
the  mike  and  start  talking, 
and  the  audio  on  the  tape 
is  dropped  below  him  by 
several  dB.  The  next  rule  is: 
Please  allow  45  seconds 
minimum  between  the  end 
of  the  last  tape  message 
sent  and  the  next  request 
to  allow  for  rewinding  of 
the  8~track  player  system. 
Thank  you. 

Into  every  life  a  little 
rain  might,  if  not  will,  now 
and  then  fall.  I  confess,  1 
do  not  know  what  happens 
when  the  newer  so-called 
(but  not)  TT  pads  are  used 
that  are  little  keyboards 
and  IC  generators  (Heath 
MicoderT'^  and  keyboard 
and  Motorola  TT*type  tone 
IC,  etc.).  Pushing  two  keys 
at  once  in  these  systems 
produces  results  I  can't  be- 
gin to  predict,  having  never 
owned  or  even  operated 
one.  You  can  only  try  it  and 
see.  I  am  reasonably  sure 
that  the  manufacturer 
would  not  be  so  careless  as 
to  allow  a  catastrophic 
failure  to  occur  on  a  two- 
key  press,  since  it  is  so  easy 
to  do  it  accidentally;  but 
you  may  get  one  or  the 
other  of  the  dual  TT  tones, 
or  not  any  tone  at  all  — in- 
stead of  the  single  tone 
desired.  Systems  consider- 
ing my  add-on  decoders 
should  poll  their  members 
using  it  for  the  number  of 
"non-reaT'  TT  pads  or  the 
results  of  two  key  press  ac- 
tions on  the  "non-rear'  TT 


pads,  or  keep  these  as  sta- 
tion housekeeping  control 
tones  for  use  by  control 
stations  having  real  TT 
pads. 

For  the  mtniscule  cash 
Outlay,  this  system  modifi- 
cation has  been  infinitely 
handy  to  me  for  use  as 
everything  from  a  trouble- 
shooting aid  to  a  high/low 
tone  pass  filter  alignment 
aid  and  a  free  (almost)  sta- 
tion control  In  my  opinion, 
it  would  pay  to  use  the 
7403s  for  both  ICs  1  and  2 
and  connect  the  outputs 
up  to  +5  volts  through 
limiting  resistors  and  LEDs, 
even  if  you  are  going  on  to 
TTL  inputs.  This  still  gives  a 
ground  or  +5  volts  output 
usable  as  a  TTL  input  and 
adds  the  ability  to  monitor 
what  is  going  on  in  the  few 
parts  the  average  system 
will  have  to  add  on.  You 
then  have  a  visible  panel 
status  indicator  (on  when 
that  single  tone  function  is 
decoded). 

While  I  can't  imagine 
anyone  finding  trouble 
with  this  that  I  can  help 
with  [i.e.,  I  can't  show  you  a 
solder  splash,  short,  etc.),  I 
remain,  as  always,  at  your 
service  for  an  SASE,  The 
wiring  for  the  TT  decoder 
portion  {7410s)  is  not  given 
on  each  IC-E  through  K  but 
does  appear  in  Fig.  1  for 
a  single  7410  for  two 
reasons:  This  is  not  part  of 
the  modification  and  new 
system,  and,  if  you  dupli- 
cate it,  you  can  hand  wire  it 
to  suit  your  own  board  lay- 
out and  fill  in  your  own 
numbers  on  a  copy  of  the 
page  from  this  magazine.  I 
muttered  the  first  time  1 
saw  this  in  another  article 
using  a  lot  of  ICs  but  it 
worked  out  beautifully  for 
me,  and  the  copy  of  the 
nice  neat  schematic  from 
the  magazine  with  my 
numbers  neatly  penned  in 
is  now  a  unique  diagram 
for  my  particular  board 
—  great  for  troubleshoot- 
ing. I  hope  this  works  out 
welt  for  you,  also,  if  you 
are  duplicating  the  whole 
system  of  Fig.  1 .  B 


5d 


EDGECOM   SYSTEM   3000A  AND   FMS-25 

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209  Mystic  Avenue 
Medford  MA  02155 
(617)395-8280   ^jas 


1^  Reader  BervfCGsee  j^age  323, 


59 


Space  Age  Surplus 

—  your  own  Saturn  V? 


Bill  and  Karha  Endrtss 

II 28  Marygon  Street 
Ki^immee  FL  32741 


With  the  tremendous 
advances  made  in 
electronics  and  the  ter- 
mination of  the  Saturn  and 
certain  other  space  pro- 
grams,  today's  surplus 
"junkie"  has  a  whole  new 
world  to  explore.  Let  us 
take  a  trip  to  a  local 
surplus  store  and  see  what 
kinds  of  goodies  a  com- 
puter hobbyist,  turned 
bargain  hunter,  can  find. 
There  is  a  super  surplus 
store  in  Orlando,  Florida, 
called  Skycraft  Parts  And 
Surplus.  It  is  owned  and 
operated  by  Bob  Fiedler, 
and  it  has  a  wide  variety  of 


both  government  and  in- 
dustry surplus. 

In  years  past,  a  trip  to 
your  local  electronic 
surplus  store  meant  hours 
spent  gazing  at  racks  of 
armed  forces  hardware. 
These  units  were  usually 
transmitters,  receivers,  and 
transceivers.  They  came  in 
shock  proof  heavy-duty 
cases,  and  the  components 
were  sprayed  with  varnish 
to  protect  them  from  the 
elements.  The  units  were 
designed  to  withstand  a 
war.  They  operated  from 
various  power  sources  that 
usually  operated  at  400  Hz. 
Numerous  articles  filled 
the  magazines  on  how  to 
convert  this  surplus  to 
civilian  uses. 

The  surplus  that  one 
finds  today  can  be  divided 


into  two  broad  categories: 

tube  surplus  and  solid  state 
surplus.  The  older  tube 
surplus  is  characterized  by 
vacuum  tubes  and  general- 
ly larger  physical  dimerv 
sions.  Most  of  this  equip- 
ment was  used  by  the 
military,  with  only  a  smat- 
tering of  industrial  surplus. 
Unless  you  have  in- 
terests in  the  ham  field  or 
you  need  a  particular 
device  for  a  specialized  ap- 
plication, my  advice  to  you 
is  to  stay  away  from  tube 
surplus.  Even  if  you  buy 
one  of  these  units  with  the 
thought  of  stripping  it  for 
parts,  you  will  still  come 
out  losing.  In  these  units, 
most  of  the  capacitors  are 
quite  old,  the  resistors 
won't  be  precision 
resistors,    and    the    power 


supply  components  will  be 
designed  for  the  higher 
voltages  necessary  to 
operate  vacuum  tubes. 

The  newer  surplus  is  an 
outgrowth  of  the  tremen- 
dous advances  made  in  in- 
dustry and  the  termination 
of  several  of  our  space  pro- 
grams. We  can  divide  this 
newer  surplus  into  two  sub- 
categories: space  hardware 
and  industrial  hardware, 

With  the  advent  of  the 
space  shuttle,  two  impor- 
tant things  have  happened 
that  have  released  and  will 
continue  to  release  great 
quantities  of  space  hard- 
ware into  the  surplus 
market.  The  first  thing  that 
has  happened  is  the  ter- 
mination of  the  Saturn  pro- 
gram. Most  of  the  elec- 
tronic hardware  that  was 


Entrance  to  shop. 


Core  memory. 


60 


used  in  the  Saturn  progrann 
was  designed  specifically 
for  that  program  and  caiv 
not  be  converted  to  the 
space  shuttle  program. 

The  second  major  factor 
in  the  release  of  space 
hardware  is  in  the  cost  ef- 
fectiveness of  the  space 
shuttle.  Once  the  shuttle 
becomes  operational, 
sometime  in  the  early 
1980s,  all  of  the  NASA  and 
most  of  the  military 
satellite  launches  will  be 
performed  by  the  shuttle. 
The  reason  for  this  is  that  it 
will  be  millions  of  dollars 
cheaper  to  launch  the 
reusable  shuttle  rather 
than  expendable  boosters. 
Both  NASA  and  the 
military  are  atready  plan- 
ning the  shutdown  of  most 
of  their  launch  support 
facilities  at  both  the 
eastern  and  western  test 
ranges  This  will  assure  us 
of  a  continuing  supply  of 
space  hardware  coming  on 
the  market. 

Industrial  surplus  is 
mainly  the  result  of  the 
tremendous  expansion  of 
technology  in  the  elec- 
tronics industry  in  this 
country  over  the  last 
decade.  With  the  develop- 
ment of  integrated  circuits 
and  large  scale  integration, 
transistorized  equipment  is 
becoming  obsolete.  This 
has  become  even  more  evi- 
dent in  recent  years  as 
energy  costs  have  shot  sky- 
high.  Transistorized  equips 
ment  requires  not  only  a 
greater  amount  of  operat- 


ing energy  than  the  newer 
ICs,  but  also,  if  the  unit  is 
large,  it  needs  substantial 
amounts  of  cooling  energy 
as  well.  With  new  tech- 
nology becoming  available 
to  industry  every  year, 
more  and  more  equipment 
is  becoming  available  to 
the  surplus  "junkie." 

The  important  dif- 
ference between  the  older 
tube-type  surplus  and  the 
newer  transistorized  sur- 
plus is  that  the  power  sup- 
plies for  the  transistorized 
hardware  usually  operate 
on  110  volt,  60  Hz  power 
sources.  These  power  sup- 
plies provide  well-filtered 
low-voltage,  high-amper- 
age outputs.  Another  big 
bonus  is  that,  in  many 
cases,  when  you  plug  in  a 
newer  unit  and  turn  it  on,  it 
works!  No  tricky  conver- 
sions are  necessary. 

Let  us  take  a  look  at 
some  ways  to  help  you 
select  pieces  of  equipment 
to  stretch  your  surplus 
dollar  further.  Equipment 
IS  sofd  in  four  different 
stages  of  assembly:  in- 
dividual components,  cir- 
cuit boards,  partially  disas- 
sembled units,  and  intact 
units.  The  surplus  shop 
pays  someone  to  disas- 
semble the  intact  units  into 
saleable  portions.  The 
more  work  he  puts  into  a 
unit  by  taking  it  apart,  the 
more  you  will  have  to  pay 
for  the  components. 

Individual  Components 
You  can  usually  find  any 


value    of    capacitor    or 

resistor  in  any  quality  or 
size  among  the  individual 
parts  sold  by  the  surplus 
store.  You  may  have  to 
look  a  little  harder  for  the 
particular  transistor  or  IC 
that  you  need.  When  buy- 
ing transistors  and  ICs, 
remember  that  you  are 
buying  used  or  factory  sec- 
ond items  in  most  cases. 
This  may  be  fine  for  bread- 
boarding  circuits  or  for 
noncritical  circuits,  but  do 
you  really  want  it  in  a 
critical  circuit?  Most  mer- 
chandise in  the  surplus 
store  is  sold  as  is,  no 
refunds  or  exchanges.  In- 
dividual components  can 
be  a  good  buy  to  help  you 
breadboard  a  new  circuit, 
but,  generally,  this  is  the 
most  expensive  way  to  pur- 
chase  surplus. 

While  checking  out  the 
individual  parts  area,  look 
for  unusual  items.  I  recent- 
ly paid  $1 5.00  for  a  1 2K  fer- 
rite  core  memory  unit  Tm 
not  sure  just  what  1  will  do 
with  it  yet,  but,  in  the 
meantime,  it  makes  an  ex- 
cellent paper  weight! 

Circuit  Boards 

I  have  mixed  emotions 
about  buying  circuit 
boards.  Sometimes  you 
can  find  a  real  bargain,  but 
you  can  also  find  a  lot  of 
iunk.  Skycraft  Parts  has 
bins  of  circuit  boards  to 
choose  from,  priced  at 
three  or  four  for  $1 .00.  You 
can  even  buy  a  barreiful 
for  $10.00.  The  boards  may 


be  populated  with  tran- 
sistors, ICs,  or  even  core 
memory.  The  capacitors 
are  usually  quality  capaci- 
tors and  the  resistors  are,  in 
many  cases,  5%  precision 
or  better. 

Whenever  I  buy  a  circuit 
board,  !  buy  only  those 
boards  that  I  can  pick  out 
and  examine  before  the 
purchase  is  made.  I  usually 
pick  out  premium  boards 
and  therefore  pay  pre- 
mium prices.  One  of  my 
favorite  purchases  was  a 
circuit  board  that  I  paid 
$7.00  for.  It  had  no  elec- 
tronic components  on  it  at 
all  It  was  instead  covered 
with  over  one  hundred 
14-  and  16-pin  wire-wrap 
sockets.  This  put  my  cost 
at  less  than  7  cents  per 
socket.  I  also  managed  to 
save  most  of  the  wire,  add- 
ing further  to  my  savings! 

When  picking  out  circuit 
boards,  try  to  have  a 
definite  goal  in  mind 
before  you  even  enter  the 
store.  Do  you  need  ICs,  or 
perhaps  heat  sinks?  Are 
you  after  resistors,  or  are 
you  looking  for  reed 
relays?  Once  you  know 
what  you  want,  you  will  be 
in  a  better  position  to  buy 
the  circuit  boards  contain- 
ing the  components  that 
you  need,  and  not  just  a  lot 
of  junk. 

When  I  look  at  circuit 
boards,  I  look  at  the  ones 
with  lots  of  ICs.  I  check  to 
see  if  they  are  of  the  7400 
or  TTL  series  of  ICs  and 
whether  or  not  they  are  in 


Power  supplier. 


Circuit  boards. 


61 


Power  supplies  and  transformers. 


Complete  units. 


sockets.  I  have  paid  as 
much  as  $1 4.00  for  just  one 
circuit  board,  but  it  was 
covered  with  fully  sock- 
eted 7400-series  ICs. 

Partially  Disassembled 
Units 

This  is  where  I  start  to 
get  turned  on.  Partially 
disassembled  units  include 
such  items  as  power  sup* 
plies,  circuit  board  card 
cages,  diode  assemblies, 
switch  and  light  panels, 
and  a  whole  host  of  other 
goodies.  If  you  are  in  the 
market  for  switches  or 
lights,  or  other  items  in  a 
quantity,  this  is  the  best 
way  to  go.  You  don't  pay 
the  cost  of  someone  com- 
pletely disassembling  the 
unit  as  with  individual 
components.  On  the  other 
hand,  you  aren't  paying  for 
a  lot  of  excess  baggage 
either.  Among  the  partially 
disassembled  units,  you 
can  usually  find  power  sup- 
plies to  fit  both  your  power 
needs  and  your  budget. 

When  purchasing  a 
power  supply,  check  to  see 
if  the  input  and  output  ter- 
minals are  clearly  marked. 
You  can  purchase  the  best 
power  supply  available  on- 
ly to  find  it  is  useless  if  you 
don't  know  which  input 
and  output  connections  to 
make.  All  you  can  do  then 
is  strip  it  for  parts.  I  don't 
recommend  this.  Any  sup- 
ply having  the  quality  com- 
ponents necessary  for  use 
in  computer  circuits  is 
usually  in  working  condi- 


tion. Vou  will  pay  a  pre- 
mium price  for  these  units. 
This  is  too  expensive  a  way 
to  go  just  for  parts. 

Intact  Units 

This  is  my  favorite  way 
to  buy  surplus.  If  you  shop 
wisely,  you  can  get  more 
for  your  money  here  than 
in  any  other  form  of 
surplus  buying.  Not  only 
can  you  get  your  money's 
worth  out  of  the  parts' 
value,  but  many  times  you 
can  also  find  working  units. 

When  shopping  for  com- 
pletely assembled  units,  I 
look  for  several  things. 
First,  I  check  to  see  if  it  was 
put  together  with  nuts  and 
bolts,  as  opposed  to  rivets. 
Not  only  do  nuts  and  bolts 
ease  disassembly,  but  you 
also  end  up  with  a  goad 
assortment  of  hardware 
when  you  are  done.  Most 
of  the  newer  units  use  cir- 
cuit boards  and  plug-in 
modules.  You  usually  end 
up  with  a  card  cage 
suitable  for  a  home  brew 
project  in  addition  to  a 
good  assortment  of  parts. 
If  it  is  possible  to  remove  a 
circuit  board  before  buy- 
ing the  unit,  do  so.  While 
looking  at  the  board,  check 
to  see  what  precision  the 
resistors  are,  whether  the 
unit  uses  ICs  or  transistors, 
and  the  overall  construc- 
tion and  condition  of  the 
board.  These  can  all  be 
used  as  indicators  of  the 
quality  and  the  age  of  the 
unit. 

Occasionally  I  will  find  a 


unit  that  uses  transistor 
sockets  for  its  transistors. 
Check  to  see  if  the  power 
supply  is  visible.  If  so,  look 
for  a  heavy-duty  trans- 
former, large  electrolytic 
capacitors,  and  heavy-duty 
power  transistors  mounted 
on  large  heat  sinks.  Also 
look  to  see  if  there  is  a  line 
cord  with  a  conventional 
plug.  These  are  all  indica- 
tions of  a  heavy-duty 
power  supply  that  might 
still  be  in  working  order 
Check  the  front  panel  to 
see  if  it  contains  a  meter  to 
check  the  performance  of 
the  power  supply  or  gives  a 
hint  of  the  voltages  put  out 
by  the  power  supply.  While 
at  it,  check  for  fuses.  Many 
times  the  output  voltages 
are  protected  by  fuses. 
These  may  also  give  you  an 
indication  of  the  output 
voltage  and  current.  Above 
alL  when  checking  out  a 
unit  for  possible  purchase, 
check  the  price  and  ask 
yourself,  "If  the  unit  is 
stripped  for  parts,  will  I  get 
my  money's  worth  in  parts 
alone?"  Unless  the  store 
owner  is  willing  to  let  you 
plug  in  the  unit  to  see  if  it  is 
operationaL  never  assume 
a  unit  is  in  operating  condi- 
tion. 

Even  if  the  unit  lights  up, 
the  only  thing  you  should 
assume  is  that  the  power 
supply  works.  Take  along 
your  voltage  meter  and 
check  whatever  you  can  in 
the  store.  I  recently  heard 
of  a  local  electronics  firm 
that    sold    20    Tektronix 


oscilloscopes  to  a  surplus 
dealer  for  $90,00  each.  The 
only  catch  was  that  the 
CRT  was  burned  out  in 
each  scope  and  a  replace- 
ment CRT  would  cost 
$1200. 

I  tend  to  prefer  space 
hardware  over  industrial 
hardware.  These  units  use 
only  the  highest  quality 
components  Most  of  the 
contacts  are  gold-plated 
and  many  of  the  soldering 
posts  are  silver-plated  for 
better  connections.  Also, 
since  these  units  are  on  the 
market  because  of  a 
phaseout,  many  of  the 
units  are  still  in  working 
condition. 

While  many  of  the  items 
for  sale  in  a  surplus  store 
have  changed  over  the  last 
few  years,  one  thing  re- 
mains: You  can  still  spend 
hours  browsing  the  shelves 
of  your  favorite  surplus 
store  in  search  of  that 
ultimate  bargain.  ■ 

Oddly  enough,  only  a 
few  of  the  many  surplus 
houses  around  the  country 
are  well  enough  organized 
to  advertise,  so  most  of 
them  are  unknown  except 
to  a  few  local  hams  and  ex- 
perimenters, tf  you  have  a 
surplus  store  which  hams, 
computer  hobbyists,  or  ex- 
perimenters might  find  of 
value,  please  send  the 
name,  address,  and  phone 
number  to  us  and  well 
publish  it  Also  include  the 
name  of  the  proprietor. 
—  Wayne. 


62 


EDGECOM'S  FMS-25  . . . 
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Edgecom's  FMS-25  2m  FM  transceiver  is  nothing  short  of  ideal  for  2n\ 
mobile  operation.  Ten  front-panel-programmable  memory  channels  provide 
you  with  fingertip  convenience  for  recalling  your  favorite  frequencies,  the 
microcomputer-controlled  PLL  frequency  synthesizer  gives  you  full 
coverage  with  any  transmitter  offset  using  push-button  tuning,  and  the 
built-in  band  scanner  lets  you  automatically  tune  the  band.  Add  to  these 
features  an  absolutely  superior  receiver,  25  Watts  of  output  power  and  you 
have  a  combination  that  provides  unexcelled  performance  at  the  low  price 
of  $439. 


FOR  THE  ULTIMATE  IN  FLEXIBILITY, 
THE  INCOMPARABLE  SYSTEM  3000A 


The  Edgecom  SYSTEM  3000A  2m  FM  transceiver  provides  unequaled  per- 
formance, incredible  flexibility  and  several  features  that  go  beyond  the 
imagination.  Twenty  front-panel-programmable  memory  channels,  a 
memory  scanner,  a  band  scanner,  two  priority  channels,  any  transmit  off- 
set, electronic  tuning,  25  Watts  of  output  power  and  the  superior  Edgecom 
receiver  are  a  few  of  the  several  outstanding  features  that  make  the  System 
3000A  the  forerunner  in  the  state-of-the-art  in  amateur  communications. 


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IdI-OM    electronics, rNC  ^-u^ 

Call  Collect  No  w  to  Order  (314)  961-9990 

2506  S.  BRENTWOOD  BOULEVARD 
ST.  LOUIS,  MISSOURJ  63144 


f^  Reader  Service — see  page  3^ 


63 


Stirling  M.  Ofberg  WISNN 
19  Loretta  Road 
Wahham  MA  02 1 54 


An  X-Band  Transceiver 


more  10-GHz  fun 


The  system  described  in 
the  following  para- 
graphs is  made  up  of 
surplus  microwave  com- 
ponents  and  other  equip- 
ment used  in  the  home  and 
mobile  station  here  at 
WISNN.  Only  one  piece  is 


described  for  construction 
because  the  main  com- 
ponents are  now  available 
to  amateurs  and  made  for 
amateur  frequencies.  The 
device  we  will  construct  is 
not  too  difficult  to  make, 
but  several  pieces  will  re- 


quire the  use  of  a  lathe. 

The  method  used  to  con- 
trol the  frequency  of  the 
Cunn  diode  oscillator  in 
the  transceiver  is  not 
new.  It  is  often  used  in 
radio  astronomy  equip- 
ment   although    in    that 


endeavor,  spectral  purity 
of  the  rf  output  is  far 
superior  to  that  achieved 
here  at  WISNN.  Many 
amateurs  have  used  the 
same  idea  in  days  past 
to  control  klystron  local 
oscillators     for     their 


lEV 


GLfl  4006 


12  250MH2 


XMIT 
REC 


ANT 


VHF  ENG. 
2  METER 
FROMT  ENQ  U, 


12V 


FM  TRANSMJTTER 


TO  £M  ANTEflNA 

1 


COAX 


BIRD  .3dB   2W 
ATTENUATOR 


ANT. 


I£V 


VHF    EWG. 

6M    FHOJyiT  END 

4r  4^MHt 


X3  MULT 
36.75  MHi 


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PATROLMAN 
VHF  ReCEIVEfi 
LO  BAND  AflOt>lFIED 


LO  IN 


5RD   MULTIPLIER 
i'47  m       lozgodHrOoT 

70Fh  HARMONIC 


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BAlyD  SWITCH,  I  hi  &M  P6SET10N 
FOR  X  SAND  OPERilTlOW  iLSO 
CONTROLS  COAX   SWITCHES 


VHF    ENG. 

2   CONVERSION 

l-F  AUOIO 


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TO  Pirj  5  K2  ON    f+>  _(^^FM455A  MODULE 

FM455A  MODULE  *--^        ^- -* 


|^7K 


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MIKE 


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TO  TEST  e  OH 
M0[ 


|47K         iAJK     T-^\ 


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01  DISC      tTR'WP^T 


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PRE  AMP 

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MAWAL  Tywe  VAR ACTOR 
IN   UNLOCK  POSITIOf* 


\        /  HORI 

\ 


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OlRECFiONAt 
COUPLER- 


REC    MIXER 


VAfiACTOfi 


GUNN  OSC 


9  VOLT 

POWER 
REGULATOR 


+  13-iSV 


'09V 


SET  TO  9V  BEFORE 
CONNECTING    TO 
QUNN   OSC 


4  TERMIftfAL  y^OUTAGE  HEGULATOR 

4 


USE   HEATSINfc 
OW  THIS  £N0  — 


rasuic 

REG 


CONTROL 
OUlF-UT 
INPUT 
COMMON 


Fig,  1.  Block  diagram  and  simplified  schematic  of  10  GHz  syntfiesizer. 


64 


receivers.  Let  us  examine  a 
block  diagram  of  my  ap- 
proach (Fig,  1).  I  hope  you 
will  come  up  with  better 
ways  to  do  the  trick,  since 
we  need  more  activity  on 
10,250  GHz. 

It  starts  out  with  a  CLB- 
400B  channeiizer.  The  GLB 
drives  a  1 3  Watt  two  meter 
transmitter  and  receiver 
and  an  appropriate  two 
meter  antenna  through  two 
coaxial  relays  which  allow 
the  use  of  the  two  meter 
gear  for  liason  when  set- 
ting  up  on  X-band  during 
field  days.  The  other  out- 
put of  the  second  coaxial 
relay  feeds  into  a  comb 
generator  containing  a  step 
recovery  diode  (SRD)  or 
snap  varactor  which  gen* 
erates  the  appropriate 
X-band  harmonic. 

The  comb  generator 
receives  its  power  for  har- 
monic generation  by  set- 
ting the  CLB  transmit  out- 
put to  12:250  MHz,  which 
is  multiplied  up  to  147 
MHz  through  the  VHF 
Engineering  1.5  Watt  two 
meter  transmitter.  The  out- 
put comb  from  the  SRD  or 
snap  varactor  produces  a 
usable  output  at  10.242 
GHz.  This  output  is  fed  in- 
to a  microwave  hybrid  mix- 
er and  mixed  with  a  sample 
of  the  Gunn  oscillator's 
output  through  a  direc- 
tional coupler  to  produce 
an  i-f  output  at  47.45  MHz. 

A  VHF  Engineering  six 
meter  front  end  set  at  47.45 
MHz  serves  as  the  second 
conversion  to  the  10,7 
MHz  i-f  input  of  the  two 
meter  receiver  i-f  amplifier 
and  associated  circuits. 
The  i-f  input  of  the  two 
meter  receiver  can  be 
switched  to  either  the  two 
meter  front  end  or  the  one 
on  six  for  liason  use,  or  for 
synthesizing  the  X*band 
transmitter.  The  six  meter 
LO  input  comes  from  the 
12.250  MHz  output  of  the 
GLB  through  a  tripler.  The 
10.7  MHz  i-f  is  further  con- 
verted down  to  455  kHz 
where  the  discriminator 
output  voltage  is  fed  into  a 
servo  amplifier.  The  servo 


The  X'band  phase  locked  rig  set  up  on  the  kitchen  table  photo  studio.  The  meter  on  the 
left  is  used  for  tuning  up.  The  GLB  sets  on  top  of  the  two  and  six  meter  receiver.  The  1.5 
Watt  two  meter  rig  is  in  the  same  chassis.  The  box  that  hangs  on  the  right-hand  detector 
mount  is  a  preamplifier.  On  the  left,  a  small  box  contains  the  servo  and  modulation  elec- 
tronics. 


electronics  are  complete 
with  an  integrator  and  are 
used  to  tune  a  varactor 
mounted  in  the  Gunn  oscil- 


lator   cavity.    Thus,    the 
system  becomes  locked  to 
the  GLB  channeiizer, 
A    second    receiver    is 


made  up  by  modifying  an 
old  Radio  Shack  two-band 
Patrolman  police  monitor. 
This    receiver,    which    is 


The  rf  plumbing  stripped  of  at!  the  electronics.  On  the  right  is  the  receiver  detector  which 
feeds  into  a  circulator.  On  the  teft  is  a  Cunn  oscillator.  The  large  square  unit  fastened  to  it 
is  the  varactor  used  to  tune  the  Cunn  oscillator. 


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tOMS  OENERATOR   DIODE  MOUNTING   DETAIL 


tunable  (or  frequency  con- 
trolled by  the  CLB  syn- 
thesizer through  the  same 
tripler  used  above)  is  used 
as  the  receiving  i-f  system 
at  26,75  MHz  when  locked 
to,  or  at,  frequencies  that 
can  be  tuned  across  the 
X-band  range.  Modifica- 
tion requires  the  addition 
of  a  preamplifier  that 
w/ou!d  match  the  output  of 
the  receiving  mixer  to  get 
the  noise  figure  down  to  a 
useful  level.  This  receiver 
does  not  have  any  band- 
narrowing  filters  in  its  i-f 
system  (10.7  MHz)  and  is 
ideal  for  the  searching  that 
is  required  for  stations  that 
obviously  will  not  be  on 
your  frequency.  It  also  has 
12'Volt  capabilities  which 
allow  it  to  work  in  the  car. 
This  receiver  could  be 
replaced  by  another  six 
meter  converter  and  VHF 
Engineering  i-f  audio 
module  as  is  used  in  the 
two  meter  setup.  Until  this 
change  is  made,  we  wilf 
continue  to  make  our  con- 
tacts With  the  old  police 
job  which  so  far  has  given 
excellent  results  over  the 
short-path  QSOs  with 
WA1NWF.  Its  bandwidth  is 
wide  enough  that  once  the 
signal    is    captured,    small 


F\^.  2.  Harmonic  genera 

drifts  can  be  compensated 
for  by  readjustment.  It  is 
not  an  easy  task  to  make 
contact  with  another  sta- 
tion unless  you  both  are 
locked  on  the  same  fre- 
quency, so  a  tunable 
receiver,  for  the  time  be- 
ing, is  a  must.  Another 
amateur,  who  is  using  a 
similar  idea,  has  a  police 
scanner  in  use  as  the 
search  receiver.  The  crystal 
oscillator  has  been 
modified  to  be  tunable  and 
is  scanned  in  the  same 
manner  that  it  would  be  if 
it  were  crystal  controlled. 
This  provides  a  fully- 
automated  scanning  sys- 
tem so  he  can  drink  his 
Coors^^^. 

The  microwave  plumb- 
ing used  in  this  set  is  com- 
posed of  pieces  either 
gathered  from  surplus 
houses  or  constructed  by 
the  author.  It  is  quite  a  task 
to  make  a  Cunn-diode 
oscillator/mixer  assembly 
such  as  the  one  used  in  this 
system.  The  frequency  con- 
trol of  the  oscillator  is  ac- 
complished by  voltage- 
controlling  a  microwave 
varactor  located  within  the 
oscillator  cavity.  A  ferrite 
isolator,  acquired  from  a 
police  radar  set,  and  incor- 


tor  construction  details. 

porated  with  the  tunable 
crystal  mount  completes 
the  mixer  half  of  the  unit. 
The  construction  of  these 
devices  is  a  formidable 
task  unless  a  well-equipped 
microwave  test  facility  and 
a  targe  amount  of  machine 
work  can  be  accomplished. 
Therefore,  it  would  be 
worth  the  constructor's 
time  if  he  incorporated  a 
Micro  wave  Associates 
Cunnplexeri'^  which  has 
all  three  of  these  items,  as 
well  as  an  excellent  horn 
antenna. 

The  Comb  or  Harmonic 
Generator 

Snap  varactor  or  step 
recovery  diodes  are  names 
given  to  these  semiconduc- 
tors by  two  of  the  leaders 
in  this  field.  Undoubtedly 
there  are  other  names,  but, 
since  this  article  started 
with  these  nomenclature, 
we  will  keep  them.  These 
semiconductors  have  a 
property  which,  regardless 
of  what  it  is  called,  per- 
forms as  follows:  An 
epitaxial  diffused  varactor 
is  designed  to  store  a 
charge  when  it  conducts  in 
its  forward  direction.  It 
conducts  for  a  very  short 
time    until    this    charge    is 


pushed  out  by  the  driving 
rf  signal.  Then  the  conduc- 
tion ceases  very  quickly. 
This  is  called  the  "lifetime" 
and  is  a  way  to  measure  the 
period  that  the  varactor 
will  store  a  charge,  and  the 
snap-time  (or  step-time,  as 
it  is  also  called)  ceases. 
These  diodes  sometimes 
require  an  external  bias, 
but  ours  will  be  used  in  the 
self-bias  mode. 

The  effects  described 
produce  a  series  of  pulses, 
which  cause,  in  our  gen- 
erator, the  first  cavity  to 
"ring/'  producing  a  train  of 
damped  waves  at  a  micro- 
wave frequency.  The  out- 
put  of  the  "ringer"  cavity  is 
then  directed  into  a  second 
cavity,  which,  by  virtue  of 
its  high  Q,  propagates  a 
more  CW-like  signal  to  its 
output  termination.  In  the 
unit  described  for  con- 
struction, these  cavities 
are  coaxial  for  the  first  two, 
and  waveguide  bandpass 
cavities  for  the  last  two. 
Needless  to  say,  much  care 
will  be  required  in  the  con- 
struction of  the  unit.  See 
Fig.  2  for  details. 

The  diodes  can  be  ob- 
tained from  many  manu- 
factufers.  Two  are  listed, 
with  references,  at  the  con- 


66 


elusion  of  the  article.  The 
two  references  are  certain- 
ly worth  the  reader's  in- 
spection in  regard  to  future 
generator  construction. 

The  parts  required  for 
this  section  are  easily  ob- 
tained. They  consist  of  a 
three-inch  section  of  cop- 
per "small  X"  waveguide 
(RG-52/UX  two  Va-inch  i.d. 
sections  of  brass  pipe  with 
1/32-inch  wall  thickness, 
and  four  end-plugs  for 
these  pipes  that  must  be 
machined  and  drilled  to 
size.  Also  required  are  a 
cover,  UC-39B/U,  which  is 
soldered  to  one  end  of  the 
waveguide,  and  a  small 
brass  box  which  is  con- 
structed from  another  sec- 
tion  of  the  same  wave- 
guide Construction  of  this 
unit  should  be  easily  ac- 
complished from  the 
mechanical  drawings  The 
iris  coupling  consists  of 
holes  found  near  the  bot- 
tom of  each  coaxial  cavity. 
The  plate  used  to  cover  the 
choke  flange,  which  is  the 
output  of  the  harmonic 
generator,  is  the  frequency 
controlling  element  of  the 
fourth  filter,  a  waveguide 
bandpass  filter. 

The  tuning  screws  found 
on  the  top  of  the  wave- 
guide must  have  the  large 
plates  loaded  to  make  sure 
that  firm  connection  is 
made  to  the  wall  of  the 
waveguide.  Once  adjusted, 
the  jam  nuts  can  be  firmly 
set  since  no  further  adjust- 
ment will  be  required,  but 
be  sure  that  the  nuts 
squeeze  into  the  lock 
washers. 

Begin  construction  of 
the  SRD  assembly  by  mark- 
ing off  the  two  holes  for 
the  circular  cavities-  These 
two  holes  are  drilled 
through  the  waveguide 
ivalls  and  are  spaced  dou- 
ble the  thickness  of  the 
pipe  wall,  so  the  material 
left  in  the  edges  of  these 
two  botes  will  be  removed. 
It  is  best  to  drill  both  holes 
mth  a  smaller  drill  and 
:hen  line-ream  out  the  re* 
Tiainder  of  the  material  un- 


til  a  tight  fit  is  achieved. 
The  two  pieces  of  Vi-inch 
tubing  should  now  touch 
each  other  on  one  side. 

Insert  each  of  the  cavity 
tubes  into  the  holes  so  that 
the  two  iris  slots  near  the 
bottom  of  each  tube  face 
each  other.  At  the  center  of 
each  of  these  cavities,  the 
holes  shown  in  the  draw- 
ings should  face  the  open 
ends  of  the  waveguide. 
These  are  the  exit  irises  of 
each  of  the  coaxial  filters. 
Next,  install  the  bottom 
plug  which  should  be  the 
machined  piece  which 
makes  up  the  coaxial  post 
for  each  cavity.  All  of  these 
pieces  should  be  turned  on 
a  lathe  so  that  they  provide 
a  very  tight  fit  into  the  tub- 
ing. Make  sure  that  the 
plug  ends  of  these  cavities 
are  parallel  to  the  bottom 
wall  of  the  waveguide  and 
that  the  iris  holes  near  the 
bottom  are  facing  each 
other.  Install  the  top  plugs, 
which  have  the  tuning 
studs,  into  the  top  of  each 
coaxial  cavity.  These,  too, 
should  be  machined  for  a 
very  tight  fit. 


This  view  shows  where  the  piston  capacitor  is  located.  The 
SRD  is  in  the  foreground  near  the  inspection  plate. 


When  all  of  these  parts 
are  aligned  and  you  are 
sure  of  the  correct  posi- 
tioning   as    shown    in    the 

drawing,  gently  heat  the 
assembly  to  a  temperature 

that  will  cause  soft  solder 
to  run,  apply  flux  to  each 
joint,  and  run  in  the  solder. 
Use    only    a    very    small 


amount  of  solder;  just 
enough  to  make  a  good 
electrical  joint.  Let  the  unit 
cool  before  attempting  the 
next  step. 

On  one  end  of  the  wave- 
guide, install  the  inside  rec- 
tangular iris  plates  as 
shown.  Then  install  the 
output  flange  on  the  end  of 


Side  view  of  the  SRD  comb  generator  which  provides  the  harmonics  for  mixing.  The  two 
tuners  on  the  top  of  the  waveguide  are  inserted  into  the  tops  of  the  coaxiat  cavities.  On 
the  bottom,  the  SRD  mounting  stud  is  in  view  and  just  behind  it  is  the  piston  capacitor 
tuning  plug. 


67 


Front  view  of  the  comb  generator  shows  the  second  inter- 
n^l  iris  which  forms  half  of  the  bandpass  filter.  The  large 

flat  plate  near  the  flange  is  the  output  iris  which  makes  up 
the  second  half  of  the  bandpass  fitter.  It  is  held  in  place  by 
the  mounting  screws  which  fasten  the  whole  unit  to  the 
directional  coupler. 


the  waveguide.  Again  heat 
the  assembly,  flux  the  iris 
plates  and  the  flange,  and 
apply  solder.  Care  should 
be  taken  not  to  overheat 
the  waveguide  such  that 
the  cavity  assemblies  are 
disturbed.  A  four-cavity 
assembly  has  been  com- 
pleted and  is  now  ready  for 
installation  of  the  SRD  and 
rf  launcher. 

Examine  the  drawing  of 
the  comb  generator  diode 
mounting  detail  on  Fig,  2. 
This  assembly  and  the  driv- 
ing coil  which  is  tuned  to 
two  meters  make  up  the  rf 
launcher.  These  compo- 
nents must  be  carefully 
assembled  prior  to  install- 
ing the  SRD  in  place.  This 
diode  is  a  small  pill  which 
has  a  form  factor  known  as 
"style  31"  in  the  micro- 
wave semiconductor  trade, 
To  install  it,  place  the  end 
with  the  large  flange 
near  the  small  circular  pro- 
trusion into  the  end  of  the 
prepared  8-32  screw,  after 
the  screw  has  been  run  up 
through  the  threaded  bush- 
ing so  that  it's  just  visible. 
The  hole  in  the  end  of  this 
screw  should  accept  the 
diode  with  a  little 
resistance.  Do  not  push 
sideways  on  the  diode  or 
you  will  fracture  the  seal. 


When  installed,  run  the 
screw  into  the  bushing  so 
that  the  other  end  of  the 
diode  engages  with  the 
launcher  line.  The  launcher 
should  have  a  matching 
hole  drilled  into  it  in  the 
correct  place.  DO  NOT 
tighten  the  diode  — just  a 
firm  fit  will  do,  Alt  of  this 
activity  is  accomplished 
through  the  inspection 
hole  on  the  top  wall  of  the 
waveguide.  The  diode  can- 
not take  much  heat,  so  any 
soldering  of  the  launcher 
rod  must  be  done  before  its 
installation. 

When  the  assembly  is 
completed,  replace  the  ac- 
cess  plate  and  connect  the 
output  of  the  two  meter 
gear  through  the  atten- 
uator shown  in  the  draw- 
ing. This  pad  will  reduce 
the  output  of  the  transmit- 
ter to  about  0.5  Watts 
which  is  all  that  is  required 
to  drive  the  diode.  It  can 
take  only  slightly  more 
power,  so  take  care! 

Put  the  output  of  the 
comb  generator  into  a 
wavemeter  and  detector. 
The  detector  will  have  to 
drive  a  very  sensitive  meter 
if  the  output  is  to  be  seen. 
There  should  be  at  least  20 
microamperes  output  and 
should  be  indicated  at  the 


frequency  described. 
If  a  smaller  indication  is 

shown,  it  should  improve 
when  the  tuning  screws  on 
the  top  of  each  cavity  are 
adiusted.  The  frequency 
meter  should  be  left  on  the 
prescribed  frequency  of 
10J40  GHz.  Adjust  the 
output  coaxial  cavity, 
which  is  the  one  nearest  to 
the  flange,  for  maximum 
and  then  peak-up  the 
ringer.  It  is  possible  to  be 
147  MHz  higher  or  lower 
since  this  is  a  comb  gen- 
erator, so  watch  the  fre- 
quency meter.  If  a  spec- 
trum analyzer  is  available. 
as  was  to  the  author,  little 
problem  will  be  encoun- 
tered in  adjusting  for  peak 
output,  but  if  not,  it  will  re- 
quire judicious  observa- 
tion of  the  frequency 
detected  by  the  frequency 
meter  cavity.  When  it  is 
correctly  adjusted,  one 
very  large  peak  right  on  fre- 
quency can  be  measured. 
When  it  is  slightly  off  peak, 
a  number  of  peaks  will  be 
observed  when  the  fre- 
quency meter  is  tuned 
through  the  desired  out- 
put. With  a  little  practice, 
full  output  wil  be  assured. 
When  adjustments  are 
completed,  be  sure  to 
tighten  the  two  jamb  nuts 
that  are  on  the  tuning 
screws.  No  further  adjust- 
ment will  be  required  if  it  is 
done  right  as  these  nuts  do 
not  work  loose. 

We  are  now  ready  to  try 
to  lock  up  the  system  to 
the  channelizer,  hook  up 
the  harmonic  generator  to 
the  system,  and  determine 
that  all  of  the  servo  con- 
nections and  indicators  are 
in  order-  Turn  on  the  sys- 
tem and  look  at  the  center 
scale  tuning  meter.  It 
should  be  right  on  the  tine. 
To  prove  it  is  locked,  and 
will  also  lock  again,  open 
the  lock/unlock  switch  and 
watch  the  meter  swing  one 
way  or  the  other  and  then 
snap  back  to  center  when 
the  switch  is  closed.  With 
the  lock  switch  closed  on 
the  search  receiver,  you 
should    be   able   to   hear 


yourself  when  you  speak 
into  the  mike.  Full  duplex 
can  be  used  on  this  fre- 
quency. 

The  circuitry  shown  for 
the  power  supply,  servo 
electronics,  and  modulator 
are  simple  and  should  give 
little  trouble.  The  output 
from  the  VHF  Engineering 
i-f  strip  discriminator 
should  be  used  as  recom- 
mended from  the  manufac- 
turer for  driving  a  micro- 
ammeter.  The  meter, 
however,  is  replaced  with 
the  circuitry  shown,  and 
then  the  meter  will  be  con- 
nected to  a  new  set  of  con- 
nections. 

Modulation  of  the  varac- 
tor  requires  a  little  care. 
Very  little  modulation  is 
needed  as  full  FM-is  used. 
If  you  are  working  a  station 
that  uses  a  wideband  re- 
ceiver, then  a  greater  swing 
will  be  required.  However, 
if  you  are  working  one  that 
has  a  system  like  the  one 
described,  then  the  devia- 
tion must  be  adjusted  to  fit 
his  receiver  using  the 
deviation  control 

Tests  throughout  the  fall 
have  gone  on  with  this  rig. 
It  is  portable,  by  virtue  of 
its  several  boxes,  and  gets 
hauled  up  on  Prospect  Hill 
in  Waltham  on  Sunday 
afternoons.  Prearranged 
contacts  have  been  made 
over  30-mile  paths  with  lit- 
tle difficulty. 

Plans  for  another  rig  of 
the  same  type  to  be  used 
for  expeditions  are  in  the 
works.  It  would  be  inter- 
esting to  see  what  can  be 
done  at  greater  ranges, 
which  I  know  are  done 
commercially,  It's  quite  a 
thrill  to  hear  full  quieting 
on  top  of  a  hill  with  a  lot  of 
old  junk  plumbed  together, 
1  hope  you  will  enjoy  the 
same  results  on  your  own 
expeditions.  ■ 

References 

Hewlett-Packard   Application 

Notes  #920  and  #928 

Step    Recovery    Diode,    HP 

5082-0830 

Microwave  Associates  Snap 

Varactor,  MA  43004 


68 


CALL  TOLL  FREE 


III 


I 


FOR   EDGECOM  .  .  . 


Ill 


THE  INCOMPARABLE  SYSTEM  3 

*TWENTY  FROMT-PANEL-PROGRAMMABLE  CHANNELS. 

'TWO  BUILT-IN  SCANNERS 

*MEMORY-CHANNEL  MONITOR. 

*  ANY  TRANSMITTER  OFFSET. 

*  FULL  TWO-YEAR  WARRANTY. 

LIST  PRICE  OlMiy  S549 


A 


THE  FMS-25 


.  ONLY  S439 


*  BUILT-IN  SCANNER 
TEN  FRONT-PANEL-PROGRAMMABLE  MEMORY  CHANNELS 

•ANY  TRANSMITTER  OFFSET 
*  ELECTRONIC  PUSH-BUTTON  TUNING 
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•SUPERIOR  INTERMODULATION  PERFORMANCE 

PERFORMANCE  THAT  CHALLENGES  YOUR  IMAGINATION 


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69 


Faces,  Places 


In  recognition  of  her  outstanding  support  of  radio  amateurs  in 
their  state,  Alabama  hams  presented  this  plaque  to  Mrs.  Edith  M. 
Parf^erat  the  Central  Aiabama  Hamfest  In  September.  Mrs.  Parker 
was  in  charge  of  issuing  amateur  radio  car  tags  from  1962  untif  her 
retirement  in  July  of  this  year. 


At  the  Veteran  Wtreiess  Operators  Assoctafion's  annual  banquet 
in  New  York  on  May  20,  Jack  R.  Popple  (left)  presented  the  Marconi 
Memorial  Gold  Medal  to  Bob  "Whitey"  Doherty  KlVV  for  his  ef^ 
forts  in  conjunction  with  the  Marconi  75th  Anniversary  Amateur 
Radio  Commemorative  Station,  KMICC^ 


T.  S.  Ganesh  VU2TS  (left)  and  his  seventeen-year-otd  SWL  nephew, 
Janardhan,  competed  in  August's  1000-mtte  Karnataka-tOOO 
Motor  Raily,  organized  by  the  Bangalore  (India}  Motor  Sports  Club. 
What  you  can't  see  in  this  view  is  the  sign  painted  on  the  bike's 
seat:  *'73  FROM  RADIO  AMATEURS/' 


Craig  McCartney  WAdDRZ/9  was  one  of  the  Chicago  Area 
Radiolefetype  Repeater  System's  members  who  manned  the 
booth  at  the  Chicago  FM  Club's  annua f  Radio  Expo  this  past  falL 


These  central  Ohio  amateurs  helped  raise  over  two  thousand 

doilars  for  charity  last  spring,  when  they  assisted  with  the  fourth 
annual  Reynoldsburg  bikeathon.  Pictured  left  to  right  are  Dr.  B. 
Morgan  He  f  I  in  WA8UVR,  Randy  Mitchell  WDBAXY,  Vernon  Holland 
WDBNAU,  Joe  Hahn  WD8NBA,  Mait  Brown  WB8WKZ  Dick  Carr 
WA4BIH,  Dennis  Roe  WA8HPW,  John  Voifmer  WB8U!F,  and  Mac 
Ceschiat  K8ZQS. 


W 


EDGECOM  SYSTEM  3 


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INCOMPARABLE  PERFORMANCE 


AND  FLEXIBILITY 


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IHb  IMS 


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iHHK  m*.         nEKET 


INCREDIBLY  PRICED  AT  $549 


SYSTEM  3000A 


•  Twenty  Front-Panel-Programmable  Memory  Channels 

•  Any  Transmitter  Offset 

•  Built-in  Memory  Scanner 

•  Built-in  Band  Scanner 

•  Memory  Channel  Monitor 

•  Superior  Receiver 

•  25  Watts  Output  (adjustable) 

•  American  Made/FULL  2-YEAR  WARRANTY 


FIVIS-25 

Ten  Front-Panel-Programmable  Memory  Channels 

Built-in  Band  Scanner 

Same  Fantastic  Receiver/Transmitter  as  System  3000A 

Any  Transmitter  Offset 

Push-Button  Tuning 

American  Made/Fuli  2- Year  Warranty 


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l^  R&ader  Service— see  page  323. 


71 


from  pagt  28 

continents  =  5  points.  Coo- 
tacts  with  HQ  station  GW8WJ 
or  GW6AQ  count  25  points. 
Total  score  is  toiat  number  of 
QSO  points  times  number  of 
prefixes  worked  (as  per  WPX 
award  rules)* 
ENTRiBS: 

Send  logs  not  later  than  Jan, 
31  to:  Peter  Lumb  G31RM,  14 
Linton  Gardens,  Bury  Saint  Ed- 
munds»  Suffolk  IP33  2DZ, 
United  Kingdom.  IRCs  appre- 
elated  for  contest  resutts- 


CONNECTfCUT  QSO  PARTY 
Starts:  2000  GMT  Saturday^ 

December  2 
Ends:  0200  GMT  Monday, 
December  4 
Rest  Period:  0500  to  1200  GMT 
December  3 
The  Candle  wood  ARA  mvites 
all  amateurs  to  participate  in 
the   annual   CT   QSO   party. 
Phone  and  CW  are  considered 
to  be  the  same  contest.  Sta- 
tions may  be  worked  once  on 
each  band  and  mode,  Including 


OSCAR  as  a  separate  mode. 
Novices  will  please  identify 
themselves  by  "/N"  unless  ''N" 
is  part  of  their  calL  Out-of-state 
portables  and  mobiles  operat- 
ing in  CT  are  requested  to  iden- 
tify themselves  as  such.  CT 
mobiles  operating  in  other  than 
their  home  counties  will 
receive  special  certrficates  pro- 
vided they  make  at  least  20  out- 
of-state  QSOs.  Mobiies  count 
as  a  separate  station  in  each 
county.  Counties  certificates 
wril  be  awarded  to  each  station 
working  ail  8  CT  counties, 
EXCHANGE: 

QSO    number,    RS(T),    and 
ARRL  section  or  CT  county. 
FREOUENCIBS: 

SSB--3927,  7250,  14295, 
21370,28540- 

CW— 40  kHz  up  from  bottom 
of  each  band. 

Novices— 3725,  7125,  21125. 
28125. 
SCORING: 

Non-CT  stations  multiply 
total  number  of  CT  QSO  points 
by  number  of  CT  counties 
worked  (8  max.).  CT  stations 
multiply  total  number  of  QSO 


RESULTS  OF  10-10  SUMMER  QSO  PARTY 

JULY  1 5-1  e,  1978 


TOP 
KflGU 
KQLT 
WOPEL 
TI2NA 
WA5JDU 
WUCP 
W40RH 
N9CP 
WD5CSK 
K5CWB 


TEN 

1 317/2358 
805M481 
78in433 
771/1356 
687/1272 
649/1215 
648/1186 
613/1137 
583/1104 
582/1089 


CHAPTER  STANDINGS 


1,  Colorado 

2,  Minute  Man 
3^  Bay  Area 

4  Land  O'  Lincoln 

5.  Gateway 

6.  City  of  Lights 

7.  Plainsman 

8.  North  Star 

9.  Sky  Blue  Waters 

10.  White  House 


11081/20704 
5629/1 0721 
3839/7201 

2934/5455 
2740/5326 
2447/4607 
2202/4196 
2164^4125 
2115/4060 
2081/3940 


as. 
1. 
z 

3. 
4. 

5, 

6* 

7. 

8. 

9. 

• 

KG 

KH 

KA 


DtSTRiCT  LEADERS 
WA1UZH         505/953 


K2DEG 

WB3FAF 

W40RH 

WA5JDU 

WB6JPY 

K7PV2 

WOaDPB 

WA9PQY 

KTCU 


407/751 
418/769 
648/1 1 86 
687/1 272 
444/604 
470/833 
236/446 
464/850 
1317/2358 


KH6ITD/KG6  107/144 
KH6JTL  389/693 

KA6HF  90/132 


OX  LEADERS 
Central  America  &  Caribbean 

TI2NA  771/1356 

South  America 

LU6DWZ  231/418 

Europe 

DF1XG  124/140 

Asia 

JA3X0G  61/105 

New  Zealand 

ZL1  BOD  260/440 

Australia 

VK2NET  383/661 


CANADtAN  LEADERS 

VE1  VE1BNN  508/910 

VE2  VE2DZ0  324/603 

VE3  VE3JAR  271/519 

VE4  VE4ADG  219/414 

VE6  VE6B8C  54/102 

VE7  VE7CMT  255/459 


points  by  number  of  ARRL  sec- 
tions and  provinces.  Additional 
DX  contacts  count  for  QSO 
points,  but  only  one  DX 
multiplier  la  allowed  overall. 
W1QL  the  club  station,  wiil  be 
operating  CW  on  odd  hours 
and  SSB  on  even  hours,  and 
counts  as  5  points  on  each 
band  and  mode.  Novice  QSOs 
count  2  points  while  OSCAR 
QSOs  count  3  points  each. 
ENTRIES: 

Logs  must  show  category, 
date,  time  (GMT),  calls, 
numbers,  mode,  bands,  QSO 
points,  and  claimed  scores. 
Separate  certificates  tor  single 
and  multi^operator  stations, 
and  all  logs  should  show  which 
class  applies.  Enclose  a  large 
SASE  for  results.  Send  lo^s, 
postmarked  by  Jan.  3,  to  CAR  A, 
c/o  Fred  Porter  WiVH,  169 
Carmen  HMI  Rd.  #2,  New 
Mtlford  CT  06776. 


FLATLANO  FARMER  10  X 

QSO  PARTY 

Starts:  1200  GMT 

Sunday^  December  3 

Ends:  2400  GMT 
Sunday,  December  3 
This  is  the  f  irsi  DX  QSO  party 
sponsored  by  an  individual 
chapter  of  the  10-X  tnterna- 
tionai  Net,  Inc.,  the  Flatiand 
Farmer  Chapter,  Score  one 
point  per  QSO  if  said  station 
does  not  have  a  Flatiand 
Farmer  certificate,  two  points  If 
they  hold  a  Local  or  Associate 
certificate  number  (station  will 
have  an  "L"  or  "A"  after  the  cer- 
tificate  number).  All  first  state 


or  first  DX  certificate  holders 
will  be  worth  2  points  for  a 
QSO.  If  the  station  is  a  Charter 
member  certificate  holder, 
score  3  points  per  QSO. 
SPECIAL: 

On  this  date  and  this  date  on- 
ly, any  station  who  does  not 
hold  a  Flatiand  Farmer  cer* 
tificate  can  qualify  for  one  by 
having  two  QSOs  with  any  two 
stations  who  have  a  Flatiand 
Farmer  certificate,  regardless 
of  whether  that  station  is  a 
Charter*  Local,  or  Associate 
member.  Slalions  wishing  to 
obtain  their  basic  certificate 
should  send  request,  listing  the 
two  QSOs,  $1.00,  and  two  first 
class  stamps  to:  Lou  Reik 
WB9YJE,  804  Commercial 
Street,  Danville  IL  61832, 
ENTRIES: 

Logs  must  have  date,  call  let- 
ters, name,  QTH,  10-10  number, 
and  Flatiand  Farmer  number,  if 
any.  Logs  to  be  postmarked  by 
Jan.  15  and  mailed  to:  Mike 
Reik  WB9YJF,  304  McKinley 
Street.  Westville  *L  61883. 
Results  of  the  contest  will  be 
published  in  the  spring  10  =  10 
bulletin,  and  other  amateur 
publications. 
AWARDS: 

A  certificate  wIM  be  Issued  to 
the  1st,  2nd,  and  3rd  place  win- 
ners in  each  US  call  area,  in- 
cluding KH6  and  KL7.  All  other 
call  areas  will  be  considered 
DX  and  a  certificate  will  be 
issued  for  1st,  2nd,  and  3rd 
place.  In  addition,  a  special 
award  will  be  given  to  the  per- 
son anywhere  in  the  world  who 
scores  the  highest  point  total. 


F tail  an  ft  Farmer  ph^pter 

10-)i/friternational  NeClnc. 


Amateur 


nrrtcATE  isissutc 

fOR  PfiaVEN  AND  SIPK^ERE  EFFOflT^TDftOMQtt 
ffll£Mll&f IP,  laCUtnVILl,  AMD  Oin^AMDING  COMMUNICAflOPifi 

Off  It^HETEftS, 


72 


There  will  be  no  multipliers 
used  or  consideration  given  for 
multi-operators, 

The  normal  requirements  for 
the  award  are  a  total  of  10 
points  as  follows:  Charter 
members  (#01C-24C)  =  5 
points;  Local  members 
(#101L-500L)  =  2  points; 
Associate  members  (#501 A  and 
up)  =  1  point.  Submit  your  re- 
quest with  $1.00  and  two  first 
class  stamps  to  the  certificate 
manager,  Lou  Reik  WB9YJE 
(see  above  for  address), 

SODBUSTER  AWARD 

The  Sodbuster  Award  Is  the 
newest  award.  It  is  a  3-  x  IVt- 
inch  self-stiGi<ing  award  that  is 
to  be  placed  on  your  basic  cer- 
tificate. This  award  requires  50 
points.  This  award  in  itself  will 
be  worth  3  points.  The  point 
breakdown  for  the  Sodbuster 
Award  is  as  follows:  Charter 
members  are  worth  5  points; 
Local  members  are  worth  3 
points;  first  staters  and  first  DX 
are  worth  2  points;  aJI  other 
Associate  members  are  worth  1 
point.  Submit  your  request 
along  with  3  first  class  stamps 
to  the  certificate  manager,  Lou 
Reil<WB9YJE. 

For  those  interested  In  ttie 
Flatland  Farmer  Chapter,  it 
meets  each  Sunday  night  at 
1900  hours  local  IL  time  on 
28/745    MHz, 

ARRL  10  METER  CONTEST 

Starts:  1 200  GMT 

Saturday,  December  9 

Ends:  2359  GMT 
Sunday,  December  10 

The  contest  is  open  to  all 
amateurs  worldwide.  All  QSOs 
must  take  place  on  10  meters, 
and  OSCAR  QSOs  are  valid. 
Each  station  can  be  worked  on 
phone-to-phone  and  CW-to- 
CW,  and  anyone  can  work 
anyone.  All  CW  contacts  must 
be  made  between  28.0  and  28.5 
MHz,  unless  working  through 
OSCAR.  When  operating  on  10 
meters,  please  avoid  the 
OSCAR  downlink  frequencies. 
CLASSES: 

Entries  will  be  classified  as 
either  single-  or  multiple- 
operator  stations.  Multiple- 
transmitter  stations  are  not 
allowed. 
E\OHAHGE: 

All  W/VE  stations  will  send 
RS[T)  and  state  or  province. 
Others  will  send  RS{T)  and  con- 
secutive serial  number  starting 
with  001.  Stations  that  are  not 
land-based  will  send  RS(T)  and 
ITU  Region  (1,  2  or  3).  The 
District  of  Columbia  is  counted 
as  part  of  Maryland. 
SCOR/NG: 

Each  completed  QSO  counts 
2  points,  or  4  points  If  with  a  W 
or  K  Novice.  The  multiplier  is 
the  sum  of  the  total  number  of 
states,  Canadian  call  areas 
(max,  9),  ARRL  countries  (not 
US  or  Canada),  and  ITU  regions 


from  non-tand-based  stations. 
Final  score  is  the  sum  of  the 
QSO    points    times   the   total 
multiplier. 
AWARDS: 

A  certificate  will  be  awarded 
to  the  highest-scoring  single- 
operator  station  in  each  sec- 
tion, Canadian  call  area,  and 
foreign  country.  Region  awards 
for  non-land-based  stations 
and  awards  for  multi-operator 
and  Novice  stations  will  be 
issued  if  warranted, 
FORMS: 

It  is  suggested  that  contest 
forms  be  obtained  before  the 
contest  from  the  ARRL,  225 
Main  St.,  Newlngton  CT  06111; 
include  an  SASE.  Checksheets 
are  not  required,  but  a  penalty 
of  3  additional  contacts  will  be 
made  for  each  duplicate  con- 
tact. 

These  rules  were  taken  from 
last  year*s  contest.  For  com* 
ptete  rules,  see  the  November 
Issue  of  QST, 

1978  CW  CHRISTMAS  PARTY 

The  Society  of  Wireless 
Pioneers  (SOWP)  Is  planning  a 
membership  Christmas  on-the- 
air  CW  QSO  Party  for  the 
weekend  of  December  16  and 
17,  1978-  The  party  will  cover 
the  full  GMT  period  to  allow 
members  around  the  wortd  to 
participate. 

All  members  with  amateur 
licenses  are  being  encouraged 
to  take  part.  The  cail  will  beCQ 
SOWP.  While  there  will  be  no 
certificates  or  other  awards 
given — everyone  who  takes 
part  will  be  a  winner  by  having 
an  opportunity  to  renew  old 
friendships,  establish  new 
ones,  and  continue  a  camara- 
derie developed  over  the  years. 

Suggested  frequencies  for 
the  party  are  between  50  and  60 
kHz  up  from  the  tow  end  of  each 
amateur  band.  Novices  should 
consider  the  middle  of  each 
Novice  band.  Additional  infor* 
mation  about  this  party  and  the 
Society  can  be  obtained  from 
the  Party  Coordinator,  Bill 
Willmot  K4TF,  1630  Venus 
Street,  Merrttt  Island  FL  32952. 

ARRL  STRAIGHT  KEY  NIGHT 

0100-0700  GMT 

Monday,  January  1 

Check  QST  for  any  changes 
in  the  rules! 

Basicaily,  rules  require  the 
use  of  a  straight  key  only.  Send 
*'SKN^'  instead  of  ''RST'* 
during  QSOs,  to  help  identify 
contest  stations.  On  80-40-20 
meters,  try  060  to  080  kHz  up 
from  the  bottom  edge  of  the 
band.  On  Novice  bands,  try  10 
kHz  up  from  the  bottom  of  the 
Novice  band.  After  the  contest 
period,  send  a  i  ist  of  calls  of  the 
stations  contacted  during  the 
contest  period,  plus  your  vote 
for  the  best  fist  heard.  Please 
mail  entries  as  soon  as  possi- 


F""^ 


THE  73  MAGAZINE  10  METER  AWARDS 

The  return  of  vigorous  solar  activity  means  that  10  meters 
Is  once  again  a  band  to  be  reckoned  with,  or  Sot's  11 -year 
cycle  of  sunspot  production  Is  about  to  hit  a  peak,  with  the 
result  that  QRP  10  meter  DX  Is  possible. 

Now's  the  perfect  time  to  convert  that  old  CB  rig  to  10  (or 
buy  a  brand  new  one  from  Bristol  or  Standard)  and  join  the 
fun.  WeWe  had  many  articles  showing  you  just  how  easy  a 
OB-to-10  conversion  really  Is.  To  give  you  an  added  incentive, 
73  is  offering  two  nifty  Certificates  of  Achievement  for  10 
meter  channelized  communications. 

For  domestic  types,  there  1$  the  10-40  Award.  This  one 
should  be  pretty  eas^—rjust  work  40  of  the  50  states.  The  DX 
Decade  Award  goes  to  DXers  who  work  10  or  more  foreign 
countries  with  a  channelized  IOmeter  rig.  We  have  endorse- 
ment stickers,  too— the  whole  bit. 

To  give  everyone  an  equal  shot  at  award  #/,  only  contacts 
made  October  1,  1978,  or  after  will  be  valid. 

Well,  don't  just  sit  there.  Get  out  your  soldering  iron,  order 
some  crystals,  and  put  that  CB  rig  on  10.  This  is  going  to  be 
fun,  so  don't  miss  out! 

RULES 

1)  ATI  contacts  must  be  made  in  the  10  meter  amateur  band 
using  channetized  AM  equipment.  Both  converted  Citizens 
Band  equipment  and  commercially-produced  units  (such  as 
those  available  from  Bristol  Electronics  and  Standard  Com- 
munications)  may  be  used. 

2}  To  be  eligible  for  award  credit,  all  contacts  must  be 
made  October  1, 1978,  or  after, 

3)  The  10-40  Award  is  available  to  applicants  showing  proof 
of  contact  with  stations  in  at  least  40  of  the  50  United  States. 
A  special  endorsement  sticlcer  will  be  available  to  those 
working  all  50  states. 

4)  The  DX  Decade  Award  is  available  to  applicants  showing 
proof  of  contact  with  at  least  10  foreign  countries.  Endorse- 
ment stickers  will  be  awarded  for  25,  50»  75,  and  100  coun- 
tries. 

5}  A  log  of  stations  worked,  with  the  date,  time,  and  type  of 
equipment  used  for  each  contact,  must  be  submitted  when 
applying  for  each  award  or  endorsement. 

6)  Each  application  for  an  award  or  endorsement  must  be 
accompanied  by  a  signed  statement  that  all  claimed  con- 
tacts are  valid.  No  QSL  cards  need  be  sent,  but  they  must  be 
in  the  possession  of  the  applicant. 

7)  To  cover  costs,  a  fee  of  $5.00  must  accompany  each 
application  for  the  10-40  or  DX  Decade  Award.  The  fee  for 
endorsement  stickers  will  be  $2.00  each. 

8)  All  award  applications  should  be  mailed  to:  Chuck  Stuart 
N5KC,  5115  Menefee  Drive,  Dallas  TX  7S227. 


ble   to   the   ARRL,    225    Main 
Street,  Newlngton  CT  06111, 

SLOW  SCAN 
TELEVISION  NEWS 

Amateur  Television  Maga- 
zine is  now  offering  a  series 
of  award  certificates  for 
SSTV  activity  ranging  from  a 
basic  award  through  several 
levels  of  difficulty  to  a  Master 
Scanner  Award.  The  beginning 
level  certificate  requires  the 
SSTV  operator  to  have  con- 
firmed five  SSTV  contacts  on 
each  of  any  five  ham  bands,  a 
total  of  25  contacts.  The  bands 
used  for  all  the  levels  may  be 
any  combination  of  the  contes- 
tant's choosing.  Additional 
awards  are  available  for  work- 
ing increasing  numbers  of  sta- 
tions on  increasing  numbers  of 
bands.  Each  certificate  is  8x  11 
inches  and  suitable  for  fram- 
ing. ATV  /[Magazine  m\\  publish 
the  names  and  calls  of  each 
certificate  holder  as  issued 
with  each  award  numbered 
consecutively.   The    various 


award  levels  are  as  follows:  5 
SSTV  QSOs  on  each  of  any  5 
bands  =  25  contacts  total;  6 
SSTV  QSOs  on  each  of  any  6 
bands  =  36  contacts  total;  7 
SSTV  QSOs  on  each  of  any  7 
bands  =  49  contacts  total;  8 
SSTV  QSOs  on  each  of  any  8 
bands  =  64  contacts  total;  9 
SSTV  QSOs  on  each  of  any  9 
bands  =  81  contacts  total;  10 
SSTV  QSOs  on  each  of  any  10 
bands  =  100  contacts  total. 

In  addition  to  the  normal  fre- 
quency bands,  the  use  of 
OSCAR  may  be  used  as  2 
bands  for  any  two  OSCAR 
modes,  i.e.,  5  contacts  via 
450/144  OSCAR  would  count  as 
1  band  for  the  basic  certificate. 

Applicants  should  send 
proof  of  QSOs  and  $1.00  for 
postage  for  each  award  to: 
SSTV  Master  Scanners 
Awards,  PO  Box  1347,  Bloom- 
ington  IN  47401.  Allow  two 
weeks  for  processing  and 
award  preparation.  SSTV  con- 
tacts must  have  been  made 
after  Sept.  1,  1978,  to  qualify! 


73 


DX 


from  page  20 

W4KPQ   daily   on    14210   at 
1200Z.  QSLlo  K4MQG. 

South  Shettands— CE9AT 

CE9AT  meets  WA2HNE  daily 
on  21335  at  1600Z.  Tune  in 
about  a  hatf  hour  earlier  to  get 
your  calf  on  the  list.  US,  VE,  and 
XE  stations  can  QSL  to 
CE2BI0,  Antarctic  Department, 
Naval  Post  Office,  Valparaiso, 
Chile,  Include  an  SASE  with 
16$  USA  postage. 

Svalbard— JW7FD 

Rag  has  been  showing  in  the 
14200  to  14250  slot  on  twenty 
meters  after  1000Z.  Between 
1700  and  1800Z  he  moves  to  fif- 
teen meters,  sometimes  visit- 
ing the  Afncana  Net  on  21355. 
QSLtoLASNM, 

Tonga— A35CR 

Claris  plans  to  be  in  Tonga  for 
about  a  year  as  a  member  of  the 
Peace  Corps.  Look  for  him 
around  14240  most  days  after 
0700.  QSL  to  Box  147,  Nuku* 
Alofa,  Tonga. 

Walvis  Bay 

The  Northern  California  DX 
Foundation  has  indicated  a 
willingness  to  supply  a  beam 
and  equipment  for  an  operation 
if  it  can  be  assured  that  it  wiil 
be  a  duly  licensed  operation, 
there  being  some  doubt 
whether  one  of  the  previously 
heard  stations  did  have  a  valid 
Walvis  Bay  license.  South 
Africa  continues  to  insist  that 
Walvis  Bay  is  their  territory  and 
has  been  for  over  100  years, 
Namibia,  on  the  other  hand, 
has  only  been  administered 
since  its  capture  from  the  Ger- 
mans during  World  War  L  This 
will  al!  be  worked  out  eventual- 
ly, so  work  them  if  you  hear 
them  and  worry  later. 

Rhodes— SVC 

SVOWTT  has  been  trying  to 
get  permisston  from  the  Greek 
licensing  authorities  for  an 
operation  from  Rhodes  Island 
in  the  Dodecanese  group. 
While  the  US  has  a  reciprocal 
licensing  agreement  with 
Greece,  it  is  still  difficult  to  get 
permission  to  operate  from 
Rhodes  and  just  about  impossi- 
ble to  get  permission  to  operate 
from  Mount  Athos.  In  the  mean- 
time, Jack  can  usually  be  found 
around  7003  from  2230  and 
21003  after  0300Z.  Give  him  a 
call  and  you'll  get  the  latest 
word  on  Rhodes. 

United  Arab  Emirates— A6XB 

A  month  or  so  back,  we 
reported  that  all  A6  operations 
had  ceased,  Apparently  this  is 


not  completely  true.  Vernon 
Dameron  K1DRN,  QSL  mana- 
ger for  A6XB  for  the  past  seven 
years,  says  that  from  the  QSL 
cards  he  is  receiving  for  A6XB, 
there  is  still  plenty  of  activity. 
CW  operation  is  completely  for- 
bidden though,  so  any  A6s  you 
hear  on  CW  are  phony. 

Brunei— VS5XU 

Look  for  this  one  from  1300Z 
daily  in  the  14200  to  14210  slot. 
A  good  operator,  he  stays  away 
from  lists  and  generally  works 
by  call  districts.  QSL  via 
DL1DL 

East  Malaysia— 9M&HG 

CW  contacts  can  be  made 
with  this  rare  one  near  14003 
around  13002  and  near  21025 
after  1500Z.  QSL  to  Horace 
Cray,  PO  Box  2242,  Kuching, 
Sarawak,  East  Malaysia. 

iraq— YilBGD 

Magid  seems  to  have  settled 
into  a  regular  routine  operating 
transceive  on  14310  after 
2100Z.  Although  handicapped 
by  a  weak  antenna  and  low 
power,  he  continues  to  do  a  ter- 
rific job  and  show  a  lot  of  pa- 
tience, seldom  losing  his  cool. 
At  the  end  of  each  Friday  ses- 
sion, a  list  is  taken  by  districts 
for  the  following  week's  ses- 
sion, QSL  to  Box  5864, 
Baghdad,  Iraq. 

Lord  Howe  island— VK2AGT 

Dick  can  usually  be  found 
around  14225  from  0600  to 
0700Z,  especially  on  Wednes- 
days. He  is  looking  for  Nebraska, 
Utah,  and  Wyoming  to  fill  out 
his  WAS.  QSL  to  Dick  Hoffman, 
Lord  Howe  Island,  N.S.W.  2829, 
Australia. 

WlongoHa- JT1BF 

On  almost  daily  from  1100  to 
1400Z.  UWONE  is  the  list-taker 
and  MG.  QSL  to  PO  Box  6, 
Vladivostok,  USSR. 


BITS  AND  PiECES 

The  Johnson  Island  Radio 
Club  has  received  a  number  of 
cards  for  contacts  with  KJ6DL, 
operator  Henry,  during  the 
period  July  18  to  August  1. 
KJ6BZ  reports  that  this  station 
is  unknown  and  cards  are  being 
returned. 

A  show  of  hands  at  the  DX 
Forum  at  DXPO  78  showed  that 
98%  fo  those  present  favored 
making  the  DXCC  awards  pure 
by  disallowing  any  cross-mode 
contacts-  A  majorHy  also 
favored  dropping  the  ''separate 
administration"  clause  from 
the  DXCC  country  criteria.  This 
is  the  clause  that  gave  us 
4U1ITU/4U1UN     and     Sable 


Island. 

There  are  three  different 
groups  from  as  many  countries 
planning  future  Bovet  action. 

The  TF6M  operation  gar- 
nered 10,800  QSOs  in  85  hours. 
They  worked  121  countries  on 
five  continents,  including  all 
states  but  Hawaii. 

Some  new  prefixes  have 
been  announced.  These  In- 
clude J4  for  Greece  and  J3  for 
Guinea  Bissau. 

Congratulations  to  W50PG, 
WA5KGQ,  and  WB50J0  for 
providing  a  vital  communica- 
tions link  to  the  Double  Eagfe  If 
during  the  first-ever  trans- 
oceanic balloon  crossing.  Ama- 
teur  radio  proved  to  be  the  only 
method  of  communications 
when  a  faulty  transmission 
cable  aboard  the  balloon 
knocked  out  the  commercial 
frequency  equipment*  A  spe- 
cial QSL  will  be  sent  to  all  those 
lucky  enough  to  make  contact. 

By  the  time  you  read  this,  the 
new  beam  supplied  by  the  Nor- 
thern California  DX  Foundation 
should  be  up  and  in  operation  at 
4U1UN. 

As  of  the  end  of  July,  total 
licensed  amateurs  in  the 
United  States  numbered 
348,561,  up  8,5%  in  the  last 
year. 

Jacky  F6BBJ,  one  of  the  top 
French  DXers,  has  been  look- 
ing toward  the  Red  Sea  and  the 
islands  off  East  Africa  for 
some  possible  DXpedition  ac* 
tion  around  the  end  of  the  year. 
Other  Frenchmen  closer  to 
home  have  been  eyeing  St.  Bar- 
thelemy  Island  north  of 
Guadeloupe  for  possible  DX- 
pedition action  if  DXCC  ap- 
proval can  be  obtained. 

Volunteer  examiners  are 
needed  by  the  FCC  to  ad- 
minister amateur  examina- 
tions to  blind  and  physically 
handicapped  applicants.  Con- 
tact your  local  FCC  office  for 
more  information. 

Rules  and  application 
blanks  for  the  World  Radio 
W-100-N,  Worked  100  Nations 
Award,  can  be  obtained  by 
sending  an  SASE  to  World 
Radio,  2120  28th  Street, 
Sacramento  CA  95818. 

The  DXAC  recently  vetoed 
DXCC  status  for  the  Republic 
of  Sealand.  The  Republic  of 
Sealand  is  an  old  British  air- 
defense  radar  tower  similar 
to  a  drilling  tower,  located  just 
off  the  English  coast.  H  was 
purchased  by  a  group  hoping 
to  turn  it  into  a  gambling 
casino.  They  issued  passports, 
minted  stamps,  and  even  had 
their  own  currency.  Apparently 
It  was  a  good  idea  because 
another  group  invaded  Sealand 
and  captured  It  by  force.  The 
original  group  then  rearmed 
and  recaptured  Sealand  and 
imprisoned  the  invaders'  leader. 
After  all  this,  the  DXAC  still  said 
no. 


Bill  A35WL  will  be  returning 
to  New  Zealand  soon,  but  while 
on  Tonga,  he  has  been  conduc- 
ting radio  classes.  Hopefully, 
one  of  the  graduates  will 
remove  A35  from  your  needed 
list. 

Last  month,  we  mentioned 
the  possibility  of  a  future  DX- 
pedition to  Oneo  Island  in  the 
South  Pacific,  For  those  of  you 
trying  to  find  it  on  your  map, 
look  northwest  of  Pitcalrn  and 
west  of  Henderson  Island. 

There  is  a  report  that  Iraq 
and  Saudi  Arabia  have  signed 
an  agreement  concerning  their 
neutral  zone,  so  if  you  haven't 
worked  8Z4,  now  is  the  time. 

FG7AS  does  QSL— some- 
times a  year  late,  but  he  does 
QSL.  On  that  same  subject, 
there  is  a  report  out  of  Moscow 
that  the  USSR  QSL  Bureau  is 
running  out  of  funds  and  must 
cut  back  on  their  manpower. 
This  win  mean  an  even  longer 
wait  for  those  needed  Russian 
QSLs. 

HH2MC  advises  that  there 
are  now  17  members  in  the  Port- 
au-prince  Radio  Club.  Haiti  has 
applied  for  lARU  membership  and 
is  waiting  for  action  to  be  taken  on 
its  application. 

Baruch  4Z4TT  plans  to  head 
back  into  the  Pacific  before 
next  summer.  VR1  is  a  possible 
stop.  Let  him  know  if  you  have 
any  favorites. 

Congratulations  to  K1DG  on 
winning  the  1978  Bermuda  DX 
Contest  and  the  all-expense- 
paid  trip  to  Bermuda  that  goes 
to  the  winner.  K3DH  was  the 
top  scorer  in  the  third  call 
district  for  the  5th  straight 
year. 

Alex  3B8DA  reports  making 
better  than  10,000  contacts 
from  3B9  and  some  5,000  from 
386. 

The  September  issue  of  Na- 
tional Geographic  had  an  arti- 
cle on  JAIQFW's  solo  walk  to 
the  North  Pole, 

KM6FC  left  Midway  Island 
last  October  and  headed  for 
Maine.  Len  logged  better  than 
23,000  QSOs  during  his  stay. 
Two  operators  remain  at 
KM6BI.  KM6BI  contacts  before 
July,  1978,  go  to  W8TIZ;  after- 
wards, to  W5RU  at  the  Delta  DX 
Association. 

It  iS  reported  that  the  VU 
Bureau  has  gone  bankrupt  and 
folded  operations.  It  might  be 
prudent  to  seek  a  direct  QSL  route 
ifor  VU  contacts. 

It  seems  there  will  be  no 
ZS6QU/ZS3  QSLs  forthcoming. 
ZSGQU  first  reported  that  an 
office  girl  had  accidentally 
dumped  the  incoming  QSLs  in- 
to the  wastebasket.  Those  who 
tried  again  received  only 
silence  for  their  efforts. 

Jack  K90TB  has  ceased  QSL 
operations  for  FPBDX/FPSML 
and  FP8HL.  He  will  still  help 
you  for  contacts  with  FP8DX/ 
FP8ML    and     his    own    call, 


74 


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75 


FP©YY. 

VU2ANI  became  a  silent  key 
In  1976  and  several  are  search- 
ing for  his  logs.  K6TWT  doesn't 
have  them. 

WCBW  is  trying  to  get  confir- 
mation  on  contacts  wHh 
CR60B  in  November.  1975,  and 
D2ACK  in  July,  1976.  Any 
assistance  would  be  ap- 
preciated. 

NOVICE  CO RMER 

Last  month,  we  talked  about 
the  incoming  QSL  bureaus  and 
how  to  make  sure  you  received 
any  QSL  cards  directed  to  you 
via  that  route.  This  month,  we 
will  discuss  the  best  way  to 
send  QSLs.  Whether  you  QSL 
direct  J  via  the  bureau,  or 
through  a  QSL  manager,  you'll 
want  to  be  able  to  pick  the  best 
route  for  that  particular  card. 
Best  route  In  this  case  means 
the  one  that  is  the  most  likely 
to  produce  a  card  in  return,  not 
necessarily  the  cheapest  or 
even  the  fastest.  Remember, 
confirming  the  contact  is  the 
result  we  are  after. 

QSL  managers  are  almost 
always  the  best  route  to  go.  If 
the  statton  you  work  has  a  QSL 
manager,  then  you  can  usually 
be  assured  of  a  fast  confirma- 
tion. Sometimes  problems 
develop  like  logs  getting  lost 
or  an  inexperienced  QSL 
manager  not  realizing  the 
scope  of  the  task  he  has  under' 
taken,  but  generally  QSLing  via 
a  QSL  manager  witi  produce 
the  fastest  results.  Mere  is  the 
way  it  works:  After  looking  up 
the  QSL  manager's  address,  fill 
out  a  QSL  in  the  normal 
manner,  but  make  sure  that 
your  call  Is  written  on  the 
report  side  of  the  card.  QSL 
managers  don't  like  to  have  to 
stop  and  flip  a  card  over  to  see 
who  sent  rt.  That  can  be  very 
time-consuming.  Next  comes 
the  SASE  BASE  stands  for 
self -addressed  stamped 
envelope  and  that's  exactly 


what  it  is.  Address  the  envelope 
in  the  normal  manner, 
except  address  it  to  yourself 
and  don't  forget  to  stamp  it. 
Now,  when  the  QSL  manager 

fills  out  your  card,  he  just 
drops  it  into  the  SASE,  seals  it, 
and  mails  it  back  to  you.  Some 
QSL  managers  like  to  have  the 
call  of  the  DX  station  and  the 
date  and  time  of  the  contact 
written  In  the  lower  left-hand 
corner  ot  the  envelope.  This 
helps  them  to  file  your 
envelope  until  the  logs  arrive 
from  the  DX  station.  If  the  QSL 
manager  is  located  outside  the 
United  States,  skip  the  postage 
stamp  and  drop  a  one  doUar 
bill  in  the  envelope.  There  are 
other  ways,  such  as  using  IRCs 
or  foreign  postage,  but  a  dollar 
bill  generally  produces  the 
best  results* 

If  no  QSL  manager  exists  for 
a  particular  station,  then  the 
next  best  route  is  direct  to  the 
station's  home  QTH.  If  the  sta- 
tion accepts  direct  QSLs.  he 
will  usually  pass  you  his  ad- 
dress during  the  contact.  This 
is  generally  a  PO  box  number, 
so  it  is  no  problem  to  pass. 
Since  the  OX  station  receives 
many  QSL  requests,  he  will 
usually  return  your  QSL  via  the 
bureau  unless  you  enclose  an 
SAE  along  with  the  usual  dollar 
bill.  Again,  IRCs  or  foreign  mint 
stamps  can  be  used,  but  the 
dollar  bili  produces  the  best 
results.  IRCs.  which  can  be 
purchased  at  your  local  post 
office,  are  too  expensive  and 
are  not  always  accepted  in 
some  countries.  One  thing  can 
be  said  for  foreign  mint 
stamps.  Once  you  stick  them 
on  your  SAE,  they  are  useless  to 
the  DX  station  for  any  pur- 
pose  other  than  to  return  your 
card.  One  thing  must  be  kept  in 
mind  when  considering  direct 
QSLing.  If  the  DX  station  says 
to  QSL  via  the  bureau  or  via  his 
QSL  manager,  there  may  be  a 
reason  that  he  doesn't  want 


cards  sent  directly  to  him.  In 
some  countries,  the  ownership 
and  use  of  a  radio  transmitter 
can  cause  problems  with  the 
I  pea  I  authorities.  Receiving 
mail  addressed  to  an  amateur 
radio  station  from  ah  over  the 
world  would  be  a  dead  give- 
away. It's  always  best  to  follow 
the  QSL  instructions  given  by 
the  DX  station.  They  will  usual* 
ly  produce  the  best  results. 

The  slowest,  but  by  far  the 
least  expensive,  method  of 
QSLing  is  via  the  bureau.  In 
many  cases,  such  as  the  Iron 
Curtain  and  Soviet  countries, 
QSLing  via  the  bureau  is  the 
only  way-  The  best  way  to  QSL 
via  the  bureau,  especially  if 
you  have  many  cards  going  to 
several  different  countries,  is 
to  ship  them  all  in  one  bundle 
to  one  of  the  outgoing  QSL 
bureaus. 

If  you  belong  to  the  ARRL, 
you  can  send  your  cards  along 
with  one  dollar  and  the  label 
from  your  last  issue  of  QST  to 
the  ARRL  Outgoing  QSL 
Bureau.  A  shortcoming  of  the 
ARRL  bureau  is  the  fact  that 
they  will  only  forward  QSLs  to 
countries  which  have  an  in- 
coming QSL  bureau.  Many 
countries  have  only  a  few  hams 
and  do  not  support  a 
QSL  bureau.  In  fact,  ot  the  319 
^'countries"  currently  rec- 
ognized for  DXCC  contacts, 
the  ARRL  Outgoing  QSL 
Bureau  will  forward  cards  to 
only  about  ISO.  Fortunately, 
there  are  several  good  com- 
mercial QSL  forwarding  ser- 
vices that  will  forward  your 
cards  anywhere  for  about  Sz 
per  card,  W3KT  is  one.  There 
are  several  others. 

In  summation,  of  the  three 
QSLing  methods  we  have  dis- 
cussed, the  QSL  manager  is 
almost  always  the  best  route, 
followed  by  direct  QSLing.  and 
then  the  bureau.  In  all  cases,  it 
is  best  to  follow  the  QSL  In- 
structions given  by  the  DX  sta^ 
tion  himself.  Good  luck. 


Ham  Help 


I  need  a  manual  and/or 
schematic  for  the  Multiphase 
Exciter  Model  20-A  made  by 
Central  Electronics,  Inc.,  dur- 
ing the  1950s.  I  will  copy,  and 
return  in  good  condition. 

A,  McGlnnis  WA2DTQ 

55  Patton  St, 

Iselln  NJ  0883Q 

I  am  indeed  very,  very  sorry 
that  I  waited  this  long  to  thank 
you  for  publishing  my  letter  In 
the  August  Issue. 

It  seems  that  when  it  rains,  ft 
pours.  (I  hate  to  use  an  old  say- 
ing.) In  August,  I  suddenly 
found  that  I  had  some  friends, 


tor  I  suddenly  received  a  few 
letters  and  coils,  and  being  par- 
tially blind,  it  took  about  2 
weeks  to  discover  that  my  letter 
was  in  the  magazine,  and  then 
to  find  It.  In  addition  to  this,  I 
was  studying  to  get  my  Novice 
ticket,  and  I  can  announce  that 
on  September  1, 1978,  t  became 
WDO??? 

Anyway,  I'm  also  busy  set- 
ting up  my  shack  and  figuring 
out  the  best  way  to  put  up  my 
antenna,  and  it  is  creating 
some  problems-  Somehow  Til 
be  able  to  be  on  the  air  when  my 
license  arrives.  However, 
whenever  I  get  some  time,  Tve 


been  slowly  trying  to  get  my 
telephone  together,  and  with 
luck,  I  should  have  it  working 
soon. 

So,  again  I  want  to  thank  you, 
and  all  the  other  people  who 
have  been  so  kind  to  me.  and 
have  done  so  much  to  help  me. 
So.  thank  you,  and  I'll  hear  you 
all  on  the  air  shortly. 

Ron  Peterson  WOO??? 

Route  1,  Box  151 

Clear  Lake  MN  55319 

I  would  be  interested  in  talk* 
Ing  to  anyone  who  has  devel- 
oped a  simple,  chirp-free  CW 
keying  circuit  for  the  Kenwood 
TR'7400A  so  that  the  trans- 
ceiver can  be  used  for  2  meter 
OSCAR  work, 

John  Mollan  WA7ATU 

7005  NE  147th  Ave. 

Vancouver  WA  96662 


QSL  INFORMATION 

A6XP— see  text 
FK8AH— Robert   Gar  be,   Avia- 
tion Civile^  La  Tontouta,  New 
Caledonia 
FP8DH— K90TB 
FP8YY— K90TB 
H5AW— 2S6AW 
HZ1BS/8Z4— 0E6EEG 
J2©BL~F6BFN 
KJ6DL— see  text 
KM6BI— see  text 
OJCMA— OH0NA 
PWCPP/PYDRO— W1  DA 
ST2HF— G4GFI 
TJ2P— see  text 
VGW-211— see  text 
VK9ZR— VK2BJL 
2D7WT— W3KT  or  via  SARL 
3B6DA/3B9DA— 3B8DA 
3B8Yy— K5YY/K5QHS 
3B9ZZ— K4YT 
5N2NAS— see  text 

Thanks  to  the  West  Coast 
DX  Bulletin,  Long  Island  DX 
Association,  and  World  Radio 
Magazine  for  much  of  the 
preceding  information. 


STATEMENT      OF      OWNERSHIP, 
MAHAGEMENT  AND  aFecyLATlON  (1^ 
quired  I?/  39  U.SC    3686).   t.  Tltla  or 
putiHoaltan;  73  Riaga^tne.  ^  Oftte  ot  til- 
ing. Oct  1,  197&  3,  Fr^ueficy  ol  fcsiye, 
ivrantfily.  A.  No.  at  rssye^  publbhod  an- 
nualty,  12-  B.  Annual  subscription  phce. 
$15.    4   LQCBtlon    Dl    Known    office   Ot 
publlcaUon  (Strem,  Ckty,  Counly,  B\q\q 
and  ZIP  Code)  {Uoi  printers!,  F'^ne  Sireet. 
Pelerbortiugh,    Hklt9bor<i   County,   N.-N. 
OaiSSt  5.  LocflUon  of  the  head^iuarlers 
or   general    "business    offrces   ol    thu 
pub4ishef5  (Not  ;>riniers]i.  Ptne  Sireet, 
PetertXTrOoQh,    H4Jt«bQro   County,   HM 
Oi^S9.  6.  Nftmes  «f»d   compt^ie  ad- 
dresses 0l  p^lisl^tf.  ectitor  and  mansg 
ing   &Allm.   PiO^iBtvBt  (ffame  and  f>^ 
dresi  Wftyrt*  Gf  t#n .  P^tfiftowough.  N  n 
0345&   Editor  (Name  and  Addrt*»:^ 
Vtfa^ne  Green.  Pet^rttorougri.  NMJKWSa 
Managing  Edilor  {HAm&  and  Addres^K 
John  Bufnetl.  PetffrbofQugh,  HM.  03459 
7,  Ownef  {it  cwned  by  &  torpor  a  lion,  Its 
n^rnp  and  ^ddr«39  musl  ti«  statsd  and 
i3t£o  (mm^iataly  iheteunder  the  namei 
and  acjcfresses  of  elockholders  owning 
01  holding  \  ptsrcani  or  more  of  total 
amount  o(  alock,  It  not  ow^ned  by  a  c.oj- 
pumllon,  thi  names  and  addre^s^s  ol 
I  he  Individual  i>4vn«f»  inusl  be  given,  II 
owned  by  a  pahnerihtp  of  ottim  ufuncat- 
porBted  fann.  its  narm  and  arddrw,  aa 
«EJF  ss  ihal  ol  tiAC^  infSviciyBl  mult  iw 
gjv^^.)  Nam«^  73  Inc..  P«l«rbQrixjQiti.  N.K 
0345B.  Wayna  Gf ten»  Petddidfiiuih  N  H 
0345i  B    Known  bOfldNoidi&fs.  moftgA- 
^|e«S,  and  olh«r  sftciiritv  l^l^^ef?.  owning 
Of  nodding  t  percent  or  more  ■eA  total 
ami04int  tft  bond$,  motigai^es&  cv  ottmt 
'■ies  (II  m**e  are  nofv#,  so  9l4tt| 
nofw.  §,  For  completion  by  non- 
profit organ  If  at  tens  aui  homed  la  mail  At 
special  rates  (Sec I  Jon  132.122,  PSM)  Thfl 
purpose,  function,  and  nonprofit  alatuB 
of   this  organisatlan  and  iti€  exfmpi 
status  foi  Federol  Income  tax  purpoaea 
(Ch&ck  om)  Not  applicati^Ee.  10    E^flent 
and  nature  of  csrculalion,  (J()  Av^raga  No. 
copies  «^cfi  iS9.ua  during  preceding  12 
months,  in  Aeluai  No.  copies  of  a  ingle 
issu^  publiftbed  n&aresl  lo  tiling  dale 
A    TotaJ  No.  DOf>ie&  pfinted  iHel  Preta 
RynJOO  77,550  maO^OOO  B    Pa^d  ciiculi- 
lloci  1.  SalM  thdToi^  cteaJers  arxj  cat- 
r  ers,  street  vendors  and  couintef  mJ«» 
>i   13.^0  (^\  14,585.  2.  Mai)  aubacnp^ 
t  3n3  m  56,290  (Yt  58,5*7.  C  Tota*  pl*d 
circui.ation  iSutm  of  1081  and  1062)  t^) 
69,BS0  lY)  72M2  0    Ffws  distribuimn  by 
majl.  carrier  or  other  means  SHamples. 
complimentary,  and  other  freacop^ea  (Xl 
740  (Y)  e^O.  i    Total  dislributkon  [Sum  of 
C  and  D\  {K\  7QM2Q  [Y)  73,952  F    Copifis 
not  diatrlbulod  1,  Qthce  use,  iefl  Cvar, 
unaccounted,  spoiled  ^ft^r  prtniina  (X} 
5,Ei40  (Y)   9,04a.   2.  Return   from   nflwa 
agents  {X}  l,lj&0  (¥)  Nona.  G.  Total  (Sum 
ol  E,  F1  and  p—nhould  equal  nat  pfeaa 
tun  stiown  m  k\  m  77.550  <YJ  90.000 
11.  t  canity  that  the  statement j  made  tuy 
me  above  ate  cotrecl  and  connpiaie.  Skg- 
n^ture  and   1i1t«   of  cditDr.   pubiisfwr, 
bg^Tftess  tnanagsr,  or  umrver,  Rooerl  R 
I^PoVnte,  &u6in«ss  litoiiflBger. 


76 


-QUASAR  VIDEO 

TAPE  RECORDER 

SALEl 


We  are  constantly  testing  ham  and 
other  electronic  equipment  for  review  In 
73  Magazine.  Jn  order  to  be  abie  to  i<eep 
tills  not  inexpensive  project  going  we 
have  to  sell  off  the  equipment  used  for 
test.  Most  of  It  has  been  used  for  a  few 
days  and  Is  In  every  way  as  good  as  new 
In  many  cases  it  is  better  than  new  since 
95%  of  the  equipment  failures  come 
within  the  first  few  hours  of  OF>eration. 

In  this  case  we  are  running  a  series 
of  lests  of  VTR  systems,  usmg  them  for 
regular,  ham  TV.  SSTV,  and  even  micro- 
computer programming  tests.  One  of  the 
best  we've  found  so  far  Is  the  Quasar  sys- 
tem, but  we  still  have  to  go  on  and  test 
the  RCA.  |VC.  and  many  other  systems 
...  so  our  Quasar  is  up  for  sale.  We  paid 
well  over  S  I  ♦OOO  for  the  Quasar .  ,  .  used 
It  for  a  few  days  and  have  gone  on  to  test 
more  systems. 


Quasar  VTR 
System .  .  .  . 


.  special  Uke  new  $675. 


Peterborough  NH  03458 
Major  Credit  Ords  Accepted. 


FT-227 

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MultJpath  Correction 
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standard  features  include  CONTINUOUSLY  tuneable  Mark  and  Space  chaonels  (1000 
Hz  to  3200  Hz),  Dual  Mode  (MARK  or  FSK)  Autostart  and  internal  high  level  neutraf 
loop  keyer  (20  to  60  ml).  Both  El  A  and  MIL  FSK  outputs  are  provided  for  direct 
interface  to  microprocessor  and  video  terminal  peripherals. 


MPC-IOOOCR 

Signal  Regeneration  & 
Speed  Conversion 

Amateur  Net:  $645.00 


A  front  panel  switch  permits  internal  TSR'200  Signal  RegeneratorSpeed  convert- 
er assembly  to  electronically  "gearshitt"  between  60.  67,  75  and  100  WPM.  All 
incoming  and  outgoing  signals  are  regenerated  to  less  than  0.5%  bias  distortion. 
Also  avarlable  wrth  DIGITAL  Autostart  (TSR  200D):  Amateur  Net:  $695.00 

MPC-IOOOR/. 
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Dual  UART  Regeneration, 
Speed  Conversion,  200 
Char,  Memory,  Word  Cor- 
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Autostart 

Amateur  Net:  $895.00^ 

The  MFC  1000 RASR  500  provides  Preloading  and  Recirculation  of  the  200  character 
FIFO  Memory,  a  keyboard  control  led  Word  Correctfon  circuit,  Variable  Character 
Rate,  Tee  Dee  Inhibit,  Slank/LTRS  Diddle,  a  Triple  Tone-Pair  AFSK  Tone  Keyer  and  a 
Character  Recognition/Speed  Determination  DIGITAL  (DAS- 100)  Autostart  mode. 

*The  MPC-IOOOR  is  also  available  without  a  TSR  assembly  and  functions  as  a  MPC- 
lOOOC  with  a  Triple  Tone-Pair  AFSK  Tone  Keyer.  This  "Basic-R"  permits  future  ex- 
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Your  QSL  will  bring  complete  specifications,  or  calf:  213-682-3705. 


►^023 


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(P.  O.   BOX  267) 

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%^  Readef  Service — see  page  323. 


71 


JUST  GETTING  ON  THE  AIR? 

See  Adirondack  for 


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D  New  Equipment 

D  Used  Gear 

D  Friendly  Advice 


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Just  5  minutes  from  NY.  Thruway—  Exit  27 


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The  HAL  ST-5000  sets  the  pace  for  an  economical 
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TTie  demodulator  features  a  hard-ilmitins  front  end, 
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Convenient  front  panel  switches  are  provided  for  850 
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The  audio  keyer  section  of  the  ST^OOO  generates 
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The  ST-5000  is  housed  in  an  attractive  blue  and  beige 
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For  complete  specs  on  the  HAL  ST-50W,  write  or  call 

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(^  Reader  Seme^see  page  323. 


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PRICES  MAY  INCREASE  SO  -  ORDER  NOW  ANP  SAVE  I  All  antennas  Quaranteed  for  1  year.  IWianey 
bai^k  trial!  Made  lr>  USA  .  FREE  INFO.  AVAIL  ABLE  ONLY  FROM. 

WESTERN  ELECTRONICS      M^Wia       Depi     AT- 12  Kearney,  Nebraaha^  GBB 4? 


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FEATURESi  CMOS  ELECTRONIC  KEYER 

BState-of'the-art  CMOS  circuitry 
m  Self  completing  dots  and  dashes 

•  Dot  and  dash  memory 

•  lamt}ic  keying  with  any  squeeze  paddte 
ms-BO  WPM 

•  Speed,  yoiume,  tone  controtSt  sfde  tone  and  speaker 

•  Low  current  drain  CMOS-battery  operation 

m  Deluxe  quarter-inch  jacks  for  keying  and  output 
^Handsome  eggshell  white  base — woodgrain  top 

•  Compact  and  portable — 1-7iB  x  4-t/4  x  &y4 
m  Grid  block  keying 

•  Wired  and  tested — fully  guaranteed — less  battery 


S25.95 


0fU9  $2.00  &/h 
NY  t9s  ^dd  rsx 


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FEATURES; 

•  Twin  paddle  squeeze  key 

•  Extra  heavy  base — non  skid  feet 
^Adiustabie  contact  spacing 

•  Touch  tension — comfort  keying 

•  Smooth  friction  free  paddle  movement 

•  Handsome  crinkle  finish  base  and  rich  red  paddles 

•  Five  way  binding  posts 

•  Use  with  TBS?  CMOS  keyer  or  any  keyer 

ELECTRONICS,  INC 
1106  RAND  BLDGv 
^Tia    hRAC        buffalo  NY  14203 


K 


EY 


1^  Header  Service— see  page  323. 


79 


Ham  Help 


)  woufd  like  to  provide  a  little 
feedback  In  regard  to  my  re* 
quest  (May,  1978)  for  informa- 
tion  on  the  8326  tube  and  the 
Halltcrafters  SR500, 1  found  out 
that  8326s  are  available  from 
CeCo  for  $22  each.  They  are 
rated  at  50- Watt  plate  dissipa- 
tion. A  direct  replacement  is 
the  6DQ5;  however,  it  has  only  a 
24-Watt  plate  dissipation,  so  be 
real  careful  on  tune-ups.  The 
6146B  was  not  recommended 
as  a  replacement  I  got  28 
replies  plus  one  phone  call  on 
thai  one.  My  second  request 
was  about  a  K-W  crystal  and  I 


Study  Guides 

and 

Code  Tapes  ~ 

The  Best  Available 


itmpai/it  3tS 


got  11  replies  telling  me  that 
K-W  Manufactufing.  PO  Box 
508,  Prague  OK  74864,  made 
the  crystal.  When  I  sent  them 
the  bad  crystal,  they  sent  me  a 
nBw  one  at  no  charge!  Ham 
Help  realiy  works!  Thanks. 

Marvin  Moss  W4UXJ 
Atlanta  GA 

I've  got  the  kind  of  problem 
that  will  require  the  help  of  real 
hams.  I  have  only  held  my 
Novice  license  a  short  time, 
and,  so  far,  I  have  only  been 
able  to  acquire  a  few  books, 
magazine  articles,  etc.  I  have 
not  yet  been  able  to  meet  any  of 
the  tocai  hams,  and  my  per- 
sonal knowledge  level  and 
technical  resources  are  still 
very  limited.  But,  nevertheless, 
I  am  determined  to  help  a  friend 
who  is  blind  enter  the  exciting 
world  of  ham  radio. 

I  would  very  much  appreciate 
hearing  from  anyone  who  may 
have  ideas  or  information  on 
operating  aids,  and  any  advice 
at  ail  on  methods  or  procedures 
of  teaching  the  blind.  Thank 
you. 

Jack  Beckwith  WB7VBC 

624  W,  Linden 

Caidwell  ID  83605 


I  am  writing  in  the  hope  that 
someone  might  be  able  to  give 
me  some  advice  or  possibly 
direct  me  to  someone  that 
might  be  of  assistance.  My  wife 
and  I  are  going  to  Cayman 
Brae,  Cayman  Islands,  in 
January.  The  purpose  of  the  trip 
is  a  diving  vacation  with  under* 
water  photography.  Anyway, 
the  other  night  I  got  the  bright 
idea  to  take  along  a  radio,  A  day 
or  two  fater,  I  sent  off  a  request 
for  a  license.  Now  comes  the 
problem  —  weight?  We  are 
allowed  a  mere  47  tbs.  With  div- 
ing and  photography  equip- 
ment I'm  afraid  the  toothbrush 
will  have  to  be  a  lightweight 
one!  Does  anyone  know  of  an 
operation  on  Brae  ?  Or,  can 
anyone  come  up  with  a  solu- 
tion . . .  short  of  not  taking  my 
wife's  diving  equipment. 
Thanks  for  the  help. 

John  Aubrey  W5EQ 

1113  N.  58th  Terr. 

Fort  Smith  AR  72904 

[  am  building  a  receiver,  and  I 
need  a  subminiature  audio 
transformer,  such  as  those 
found  in  small  transistor 
radios,  with  a  10,000-Ohm 
primary  and  a  I^OOO-Ohm 
secondary.  Also,  I  must  obtain 
a  speclai  item  from  a  store  In 
Regina.  Saskatchewan.  1  would 
greatly  appreciate  hearing  from 
any  Canadian  ham  who  could 


be  of  assistance  in  obtaining  it. 

Paul  Hoegstrom  WOaOTW 

$962  S.  Park  Blvd. 

Parma  OH  44134 


[  need  information  to  con- 
vert 3  Motorola  MtCOR 
T53RTN1190A  to  ham  and/or 
MARS  2  meter  frequencies.  I 
also  need  data  on  the  SC-946 
handset.  Thanks. 

Frank  Noliette  KAiAOJ 

522S  Clark 
RlchardS'Gebaur  AFB  MO 

64030 


I  need  a  schematic  diagram 
and  service  manuals  for  an 
Icom  DV-21  digital  vfo,  a  Ka- 
tional  NFS  receiver,  an 
Amplldyne  Labs  model  C14 
220-MHz  converter,  and  a  Cen- 
timeg  432-MHz  converter, 

Jung  Y.  Lem  KB6B0 

S222  Coringa  Dr. 

Los  Angeles  CA  90042 


I  need  help.  I  bought  a 
Mustek  integrated  tone 
receiver  chip,  #MK5102(nl-6, 
but  I  can't  get  it  to  do  anything 
but  look  back  at  me  from  my 
table.  I  need  help  specifically 
for  the  input  and  output  cir- 
cuits. 

Morman  E.  Rosenspan 

64  Berry  Avenue 

Staten  Island  NY  10312 


An  ancient  amsieur  pwveib  lias  it  that-  "11  fou  can't  hear  Ihem.  ym  can't 

wntk  them  '' 

Ttiars  one  rtason  wtiy  our  linearized  anip^ifief /pieamplifier  combinaiiDns  art  the 

fastest  s^knq  ^^g&  in  The  amatiw  radio  ma/Vet  Hot  vtnhi  dt  they  provide  you  with 

9  itB  jahnost  2    S '  umts)  of  incn^eri  signal  at  ttta  other  guys  rtcetver;  but,  they 

a  1^0  prtivide  you  with  a  greatly  improved  capability  i^  rtad  his  sipal.  Our  trans- 

milting  arrp/preamp  combos  don't  just  give  mora  output  powef;  they  abo  provide 


you  with  the  iRCf«as«it  sensitivity  you  need  to  makt  those  contacts  that  you've  fiever 
mide  tetort  ftemembet.  Ite  Other  guy  may  not  have  a  Lunar  ampvp/f  amp  yet  Our 
bitter  than  2  dB  noise  f  igif  e  irKlicates  thai  Lunar  Has  achieved  the  practical  limit  at 
2  meters  for  any  bcal  wse  conditmns  ymj  might  have.  Whettier  you'f«  bouncing 
lignais  olf  the  moon  or  ir^ng  to  pcb  up  a  noi^y  signaJ  in  your  car.  Uinsr  s  preamp  m 
our  bt-lineir  amplifier  is  the  best    hearing  ant '  iw  can  havt. 


LINEARIZED  AMPLIFIERS 

Accepts  all  modes  Power  ranges  from  50  to  250 
watti.  frequencies  from  50  MHz  to  220  MHz. 
From  itSd  95 

RECEIVING  PREAMPS 

For  the  most  demanding  needs  where  lew  noise 
figure  h  importai^t  Medium  and  high  ga<n  models 
now  ava]ai}le  fm  trequenciis  2B  to  45€  MHl 
From  S34.95 


LUNAR  DfMERS:  AfilFDWA  rmi-fliiinnralmn  4*18*.  »???  H  t;rtni|i.  PI»»Mi  RW?,'  ■  PA  C  E  "  J?tl  W  W^tmnri  Turittn  hblGh  -  CMironNIA-  fludUr  'iolfli  IHIiiJ  Slufmsn  W»t.  lnti]»9!33S^ 
AiLiHi  I  mn  RiUm.  l  BG'L  Miiiiim  Vi  tl*(iH  R  ^d  Su  ii  Di  una  J  ^  1 3  ll '  G  A  A  E  leetmniiC*.  JM)  1 1J  S  WiNniiiflrt  w  a«  -s  im,  C*i  mn  ^D  M^  *  Hi  M(  C,  J I J  W.  tu  irarrt  (  Si  I  iii ,  ^  mill  lithm*  93 1 Q 1 '  Hmty  H  idd. 
1134QV\/  LUffnpc  Blvd  Lqi  Aih^iI«i  904^4  ^HinrvAudD  0^1  II  Eudd.Anitimn  12901  *  MAO,  Z62[l  W  LlFrtui,  Atli1lt«n92B01  ^HHi]  SMStpulvtdaBivHi.,  Vinh(|ytgi401  «I^RD,  &31SK«MnV  Vii 
Hflid  SitiDlvoQ  42123  ■  Mntl  999  Huwird  ^vt  filn'^\ql^m^Hl^^Ji*fmtvmi^K^tm»a.iB2E  Sun  Aw.  Haitnu  12335  -  liuii  IlKl^DfiiEi  4^7  BroMinvaf  CMi  Vala92{)1D  ■  Tcwii  ItantronJa 
;«:»DiMKU^dFtiMrr  MB44»ftV4|li3rfr/^*  QtLAWAI^r  M«mif  I^hf St^  M  Miwkgw  R atd  lltwtpll  IBT^-f  lORttU  Hi^iftjiriiit  1D^ELiiBrivSli|*t  JuhuovjUc^Z^Jje- WilltlDSbupi 
^lli!1VirwOfni.MMtUllb33M0-Gf0B)iiA  A»#«WMfB^  3017  Mwrn  Ait  CikKtaa  3 1  ^  ■  IMSAS- RiittW,  624 1 M  tMftHUc.  WicMiC'?!?*  W1ii«ri<^nunukaiii  I^WH 
Uvtt^  HtHi  qfaifa  n«1  •  MMUn.  Ww  l^tt*  4  Tv  B»  mi  itwm  4al3ft  *iKUHE~  SfHnH  lAiwAriBu!  Hm  IDM  ltmm4  01142  <■  UftRyUUlO  TvtM  Ummsmwuvt  Hi  9.  «N  fpv 

U  B3}|^tv^b^l^rtTI1B*niUKTte1lWSfeiiL!0n««Wk^.taf»Uf  !$»e-lifcvMfH««a.  trM^faAvli 
11164  ■  KlBTtlflttHt  Uwt^n  tJUttmtim  tAj  <»Biiw  *mt.  I»tf  EUtfP  Hj^  -  awtw  cAWaii^A  ^mrftHmmt  J4I  ^ii^m  l»iri  Bmmii  ani^IEKtt  Wi 


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SiMtSt  h^m  rem  noo  -  uftuun:  suta.  nikmr,  im.  m^m.  inv 

PHf  I » IP1C  *  GCMWir  iMf  N*HCi  Shit  KH.  PvttBli  Vtt.  roH.iiii  ii  I  - 
JWW  ftm  tfctwKi  KiiMiiKi  mat  ^  ^^9  irpgii  mit  Mmwta  1U|»  m 
•ranfUGU;  GnnvMBLifiirili  l^iUi.  litfeRHdft  M^pPm  fl^Ptrta' VINf 


B«tiif  SessEin'i  Gfifitittgi  to  til  ifnilburt  everrwhsrtl 


electronics 


*^L17 


285  KUfiT/  'i" Air  IT 

susTE  in 


iHIITMlllilittD 

htm  Hum  ftu  w 
to  wpftfi  prodidit 
VDitThinlMAighf 

t(l  be  ptoviliin^  fair 
you  Oroputji  IJni 
with  yavi  idnsi: 
Liuit  Atteiiui  - 
WISNMT 


80 


Ip"^  R&ader  Service — see  pag^  32X 


Social  Ei/ents 


HAZEL  PARK  Ml 
DECS 

The  Hazel  Park  Amateur 
Radio  Club  will  hold  its  13th  an- 
nual Swap  &  Shop  on  Sunday, 
December  3, 1976,  from  9:00  am 
to  3:00  pm,  at  Hazel  Park  High 
School,  Hazel  Park,  Michigan. 
Prizes  roclode  a  TS-520S.  HW* 
2036A  with  MIcoderT''^,  and  a 
Bird  Model  43  wattmeter  with 
element.  Admission  is  $1.00. 
There  will  be  food,  door  prizes, 
and  free  parking.  Reserved 
talkie  space  is  75^  per  foot. 
Talk-in  on  146.52.  For  delails, 
send  an  SASE  to  Robert 
Numerick  WB8ZPN,  23737 
Couzens,  Hazet  Park  Ml  4B030. 

SOUTH  BEND  IN 
JAN  7 

The  Repeater  Valley  Hamfest 
Swap  &  Shop  will  be  held  on 
Sunday,  January  7. 1979,  at  the 
New  Century  Center  on  US 31  in 
South  Bend,  Indiana.  This 
event  will  be  held  indoors  with 
food  service  available.  An 
automobile  museum  and  art 
center  are  in  the  same  building. 
Tables  are  $3.00.  Talk-in  on 
146,1 3/.73,  .34/.94,  and  .52/.52; 
147.99/.39,  .93/.33,  .84/.24,  and 
.69/,09.  For  information,  con- 
tact Wayne  Werts  K9IXU,  1889 
Riverside  Drive,  South  Bend  IN 
46616;  (21 9)-233-5307. 

RICHMOND  VA 
JAN  14 

The  Richmond  AmateurTele- 
communications  Society  will 
hold  its  Frostfest-ll  on  January 
14,  1979.  at  the  Bon  Air  Com- 
munity Center  In  Richmond, 
Virginia.  Talk-in  on  ,28^88, 
.34/.94,  and  .52.  There  will  be  a 
technical  symposium,  a  draw- 
ing, and  a  home-brewers'  con- 
test with  two  divisions,  over  IS 
and  under.  FCC  exams  will  be 
administered  starting  at  10:00 
am.  To  take  the  exam,  mail 
Form  610  at  least  five  days  prior 
to  the  Fest  to  the  address 
below.  Commercial  exhibitors 
are  by  invitation  only.  There  will 
be  an  indoor  flea  market  wfth 
one  table  for  $2.50  and  outdoor 
tailgate  space  for  $1.00.  Admis- 
sion is  $2.50.  For  information, 
contact  the  Richmond  Amateur 
Telecommunications  Society^ 
PO  Box  1070,  Richmond  VA 
23208. 

SOUTH  FIELD  Ml 
JAN  21 

The  Southfield  High  School 
Amateur  Radio  Club  will  hold 
its  14th  annual  Swap  &  Shop  on 
Sunday,  January  21,  1979.  at 
Southfield  High  School,  South- 
'ieid,  Michigan,  at  10  Mile  and 
_asher.  Admission  is  SZOO.  For 
nformation,  send  an  SASE  to 


Robert  Younkers,  24675  Lasher 
Rd.,  Southfield  Ml  48034,  or  call 
{313)-354-8210. 

MfAMi  FL 
JAN  27-23 

The     Dade     Radio    Club 
presents    the    19th    annual 
Tropical  Hamboree  and  ARRL 
South    Florida  Convention  on 
January  27-28.  1979,  in  Miami. 
Florida.  Over  one  hundred  ex- 
hibitor  booths,    a   giant    flea 
market,  and  several  technical 
and    group    sessions    will 
operate  simultaneously  In  com- 
pletely separate  areas  of  the 
Flagler  Dog  Track  Auditorium 
building.  With  the  Convention 
immediately    following    the 
Miami    Board    Meeting,    most 
Division  Directors  and  HQ  of- 
ficials will  be  present  for  the 
ARRL  general  session.  Exten- 
sive   free    parking,    including 
overnight    space    for    RVs,    is 
available  on  the  grounds.  Pre- 
registration  is  S3.00;  $4.00  at 
the  door.  For  up-to-date  infor- 
mation,   booth    space,    flea 
market  table  space,  RV  parking 
space  reservations,  and  hotel 
rates,  write  DRC  Hamboree.  PC 
Box  350045,  Riverside,  Miami 
FL  33135. 

MANSFIELD  OH 

FEB  11 

The  Mansfield  midwmter 
hamfest/auction  will  be  held  on 
February  11.  1979,  In  a  heated 
building  at  the  Richland  County 
Fairgrounds  in  Mansffeld, 
Ohio.  There  will  be  prizes  and  a 
flea  market-  Doors  will  open  to 
the  public  at  8:00  am.  Talk-in  on 
146.34^.94.  Advance  tickets  are 
$1.50;  $2.00  at  the  door.  For  in- 
formation, contact  Harry  Friet- 
chen  K8HF,  120  Homewood, 
Mansfield  OH  44906,  or  phone 
(419)-529-2801  or(4l9)-524-1441. 

LANCASTER  PA 
FEB  18 
The  7th  annual  Lancaster 
hamfest  will  be  held  on  Sun- 
day, February  18,  1979,  at  the 
Guernsey  Sales  Pavilion,  US 
Rt.  30  &  PA  Rt.  896,  Lancaster, 
Pennsylvania,  Doors  will  open 
at  8:00  am  and  there  will  be  a 
prize  drawing  at  2:00  pm.  Ad- 
mission is  $3.00,  and  table 
reservations  are  S2.00  in  ad- 
vance.  There  is  a  new,  larger  in- 
door flea  market  area.  Food 
and  soft  drinks  will  be 
available.  Talk-in  on  146.01/,61. 
For  further  information,  con- 
tact SERCOM,  PO  Box  6082. 
Rohrerstown  PA  17603. 

DAVENPORT  I A 
FEB  25 

The  Davenport  Radio  Ama- 
teur Club  will  hold  its  hamfest 


on  February  25,  1979,  at  the 
Masonic  Temple  in  Davenport, 
Iowa.  Admission  is  $2.00  in  ad- 
vance, $2,50  at  the  door.  Re- 
freshments and  tables  will  be 
availabfe,  TaJk-in  on  .287.88  and 
.52.  For  further  information, 
send  an  SASE  to  John  S.  Birm- 
ingham  WB0QCC,  2022  Brown 
Street,  Davenport  I A  52804. 

LIVONIA  Ml 
FEB  25 

The  Livonia  Amateur  Radio 
Club  would  like  to  announce 
that  the  9th  annual  LARC  Swap 
'n  Shop  will  be  held  on  Sunday, 
February  25, 1979,  from  8:00  am 
to  4:00  pm,  at  the  new  location 
of  Churchill  High  School  in 
Livonia  ML  Tables,  door  prizes, 
refreshments,  and  free  parking 
will  be  available.  Talk-in  on 
146,52  simplex.  Reserved  table 
space  of  12-foot  minimum  is 
available.  For  further  informa- 
tion, send  an  SASE  to  Neil  Cof- 
fin WA8GWL.  c/o  Livonia 
Amateur  Radio  Club,  PO  Box 
2111,  Livonia  Ml  48151, 

VERO  BEACH  FL 
MAR  17-18 

The  Treasure  Coast  Hamfest 
will  be  held  on  March  17-18, 
1979,  at  the  Vero  Beach  Com- 
munity  Center,  Vero  Beach, 
Florida.  Activities  will  include 
prizes,  drawings,  and  a  OCWA 
luncheon.  Admission  is  $3.00 
per  family.  Talk-in  on  146.13/ 
.73,  146.52/.52,  and  222.34/ 
223.94.  For  information,  write 
PO  Box  3068,  Vero  Beach  FL 
32960. 

WAUKEGAN  IL 
MAR  25 

The  Lfbertyville  and  Munde- 
lein  Amateur  Radio  Society  will 
hold  its  second  annual  Lamars- 
fest  on  Sunday,  March  26, 1979, 
at  the  J.  M.  Club,  708  Green^ 
wood  Ave.,  Waukegan,  Illinois. 
Doors  will  open  at  7:00  am. 
There  will  be  plenty  of  free  park- 
ing, door  prizes,  and  a  large  in- 
door flea  market  for  radio  and 
electronic  items.  Tables  will  be 
available  at  $4.00  each.  Ad- 
vance tickets  are  $1.50;  $2.00  at 
the  gate,  with  children  under  tO 
free.  Hot  lunch  will  be  available 
and  Ihere  will  t>e  plenty  of  com- 
mercial exhibits  and  demon* 
strations.  Talk-in  on  146.94.  For 
further  information,  write 
LAMARS  {include  SASE, 
pleasej  at  1226  Deer  Trail  Lane, 
Libertyville  IL  60048,  or  call 
(312^387-1599. 

MUSKEGON  Ml 
MAR  30-31 

TTie  Muskegon  Area  Amateur 
Radio  Council  is  sponsoring 
the  ARRL  Great  Lakes  Division 
Convention  and  Hamfest  at  the 
Muskegon  Community  College 
in  Muskegon,  Michigan,  on 
March  30-31.  1979.  This  event 
will  feature  manufacturers'  ex- 


hibits, technical  forums,  and  a 
large  swap  shop.  Ample  park- 
ing and  dining  facilities  are 
available.  Friday  evening  at  the 
Muskegon  Ramada  Inn,  there 
will  be  a  "Ham  Hospitality" 
with  libation  courtesy  of  the 
MAARC  and  a  Wouf  Hong  ini- 
tiation. For  additional  informa- 
tion, contact  MAARC,  PC  Box 
691,  Muskegon  Ml  49443,  or  H, 
Riekels  WA8GVK;  (616)-722- 
1378/9. 

NATCHEZ  MS 
APR1 

The  Old  Natchez  ARC 
Hamfest  will  be  held  on  Sun- 
day, April  1,  1979,  at  the 
Natchez  Convention  Center, 
Natchez,  Mississippi.  The 
event  will  be  indoors  and  air- 
conditioned.  There  will  be  free 
admission  and  swap  tables. 
Talk-in  on  146.31/. 91  and 
146.52.  For  information,  write 
ON  ARC,  1226  Magnolia  Ave^ 
nue,  Natchez  MS  39120. 

UPPER  HUTT  NZ 
JUNE  1-4 

The  1979  Annual  Conference 
of  the  New  Zealand  Associa- 
tion of  Radio  Transmitters  will 
be  held  on  June  1-4,  1979,  at 
Upper  Hutt,  New  Zealand. 
Visitors  are  welcome  to  attend 
this  conference.  For  registra- 
tion forms,  contact  the 
Secretary,  1979  Conference 
Committee,  PO  Box  40-212,  Up- 
per Hutt  NZ. 

LOUISVILLE  KY 
JUN  29  JUL  1 

The  Louisville  Area  Com- 
puter Club  will  hold  its  4th  an- 
nual ComputerfestTM  igjg  on 

June  29  through  July  1, 1979,  at 
the  Bluegrass  Convention 
Center,  Louisville,  Kentucky, 
Activities  include  a  flea  market, 
seminars,  and  exposition,  as 
well  as  activities  for  the  entire 
family.  Seminar  and  exposition 
admission  is  $4.00.  Pre-reg- 
istered  Ramada  Inn  guests 
($29.00,  single;  $34.00,  double) 
receive  free  admission.  For  ad- 
vance mail  information,  write 
Computerfest  '79.  Louisville 
Area  Computer  Club.  PO  Box 
70355,  Louisville  KY  40270.  or 
phone  Tom  Eubank,  Chairman, 
at(502f-895-1230. 


81 


SSTV  Recorder  Controller 


replaces  your  index  finger 


C.  A.  KoHar  K3JML 

1202  Gemini  Si. 
Nanticoke  PA  IS6S4 


This  article  describes  a 
device  which  will  make 
the  recording  of  a  picture 
from  a  scan  converter  or 
SSTV  camera  more  conve- 
nient. At  present,  using  the 
Robot  400  scan  converter, 


the  procedure  1  use  gen- 
erally goes  tike  this:  The 
closed  circuit  TV  camera  is 
adjusted  for  proper  focus 
and  picture  content.  A 
frame  is  then  snatched  by 
the  400  and  entered  into  its 


memory  according  to  in- 
structions  in  the  manual. 
Once  entered  into  the 
memory,  the  picture  can 
be  recorded  for  future 
playback  by  putting  ''trans- 
mit select"    in   "memory" 


TO 

'HE  MOTE' 
JACiC 


SSTV  t»i  > 


SSTV  TO 
BECOHtJER 


Fig.  "I.  SSTV  tape  recorder  synchronizer.  Q1  —any  general-purpose  PNP  silicon  transistor;  Q2  —  any  general-purpose 
NPN  silicon  transistor. 


82 


and  recording  the  resulting 
SSTV  signal  from  the  audio 
cable  plugged  into  the  ''to 
tape''  jack  on  the  back  of 
the  400. 

This   is  where   the  tape 
recorder  comes  into  play. 
Up  to  now,  the  procedure  I 
followed  was  to  watch  the 
FSTV  monitor  for  a  bl ink  in- 
dicating  the   end    of   one 
frame  and  the  beginning  of 
another.    At   this    point,    I 
would    count    seven    sec- 
onds   [a    complete   frame 
takes  about  eight  seconds) 
and    engage   the   tape   re- 
corder. This  ensured  that 
the  1200  Hz  reset  pulse  at 
the  end  of  the  frame  would 
be  captured  on  tape  to  en- 
sure  proper  vertical   sync 
for    the    next    complete 
frame.  I  then  would  watch 
very  closely  for  three  more 
winks,  indicating  that  three 
complete  frames  had  been 
recorded.   After  the  third 
wink,    the   tape    recorder 
would    be    disengaged. 
Three  frames  is  the  usual 
amount  sent  by  SSTVers  to 
try  to  ensure  copy  of  the 
video  through  QRM.   The 
disadvantage   to   this   sys- 
tem   is    the    necessity    of 
watching  for  a  wink,  count- 
ing   seven,    engaging    the 
tape    recorder,    counting 
three    more    winks    (4    in- 
cluding   the    one    imme- 
diately after  engaging  the 
tape    recorder),    and    then 
disengaging    the    tape 
recorder.    A    momentary 
distraction    can    result    in 
missing  the  sync  pulse  and 
starting  in  the  middle  of  a 
frame  or  recording  more  or 
less  than  three  frames. 


^^^^ 

o  o  o  o  o  o 

E       2       ui      tJ       —      cy 
^       4t       S       ^ 
^       *       -       « 

e  o  1  ©      © 

Fig.    2.    Suggested 
panel  layout 

front 

With  an  SSTV  camera, 
lighting  and  focus  are  first 
set  up  as  usual.  Then  you 
must  wait  until  the  scan 
gets  near  the  bottom  of  the 
frame,  at  which  time  you 
engage  the  tape  recorder. 
Next,  you  must  observe 
three  complete  frames  and 
then  stop  the  tape  record- 
er. As  with  the  400,  en- 
gaging the  tape  recorder 
when  the  scan  is  near  the 
bottom  ensures  that  the 
sync  pulse  for  the  first 
frame  you  will  record  wil 


also  be  captured  on  tape. 

Enter  the  SSTV  tape 
recorder  synchronizer. 
With  this  device,  all  you  do 
is  enter  the  picture  into  the 
400  memory,  set  the  trans- 
mit selector  on  the  400  to 
"memory,"  press  the 
''arm"  button  on  the  syn- 
chronizer, and  go  about 
your  business.  The  syn- 
chronizer will  turn  on  your 
tape  recorder  at  the  proper 
time  to  capture  the  initial 
sync  pulse,  record  three 
complete  frames,  and  shut 


off  automatically.  There's 
no  need  to  get  cross-eyed 
watching  for  winks  on  your 
fast-scan  monitor.  With  an 
SSTV  camera,  hit  the  arm 
button  as  soon  as  focus 
and  lighting  are  set  up,  and 
the  synchronizer  will  do 
the  rest  — no  more  count- 
ing frames. 

Circuit  Description 

Initially,  the  circuit  is  fn 
a  standby  condition  where 
pin  three  of  the  7400  (see 
Fig.  1)  is  low.  This  turns  off 


<      ^ 


rc;i 


**.  .^^ 


11^0^ 


PWR 


ARM 


D     G 


SSTV 


TAPE     RECORDER 
SYNCHRON  I  ZER; 


K3  JML 


Front  panel  layout  of  the  prototype. 


83 


Enclosure  opened  to  reveal  the  perfboard  construction  and  parts  layout. 


Q2,  de-energizing  the  relay. 
It  also  grounds  pins  10  and 
13  of  U4,  resetting  the  flip- 
flops  to  zero.  The  R-S  flip- 
flop  consisting  of  U3C  and 
U3D  is  in  the  state  where 
pin  11  (Q  output)  is  low. 
This  grounds  pin  4  of  the 
555,  disabling  it.  This  initial 
state  is  ensured  by  Q3, 
which  momentarily  grounds 
pin  9  of  USD  when  power  is 
applied.  The  circuit  is  set 
into  operation  by  depress- 
ing the  arm  push-button, 
which  now  makes  U3C,  pin 
13  low,  which  causes  pinll 
of  U3C  as  well  as  pin  4  of 
the  555  to  go  high,  enabling 
the  timer  and  lighting  the 
arm  LED. 

SSTV  audio  is  fed  to  pin 
3  of  the  567  decoder 
through  a  .1  uF  capacitor. 
The  output  of  the  decoder 
(pin  8)  is  normally  high  and 
goes  tow  whenever  a  1200 
Hz  reset  pulse  is  detected. 
This  turns  on  Q1,  bringing 
pin  2  of  the  555,  pin  12  of 
the  74107,  and  the  positive 
end  of  the  1 00  uF  capacitor 


to  ground.  The  100  uF 
capacitor  is  necessary  to 
prevent  the  74107  from 
counting  more  than  once, 
because  of  glitches,  during 
the  duration  of  the  reset 
pulse.  When  pin  2  of  the 
555  goes  low  momentarily, 
its  output  (pin  8)  goes  high, 
lighting  the  LED  for  a  time 
determined  by  the  1  meg 
pot  and  10  uF  capacitor 
connected  to  pins  6  and  7. 
In  this  case,  it  is  set  up  for 
seven  seconds.  At  the  end 
of  seven  seconds,  pin  3 
goes  low,  pulling  the  end  of 
the  500  pF  capacitor  to 
ground,  which  in  turn  pulls 
pin  1  of  U3A  to  ground 
momentarily.  This  sets  the 
R-S  flip-flop  U3A/U3B, 
making  pin  3  high.  This 
high  turns  on  Q2,  pulling  in 
the  relay  which  turns  on 
your  tape  recorder.  It  also 
makes  pins  1 0  and  1 3  of  the 
74107  high,  enabling  the 
dual  j-K  flip-flop,  U4, 

U4  will  now  count  the 
next  four  reset  pulses  (the 
initial  reset  pulse  and  also 


the  next  three  indicating 
three  complete  frames) 
supplied  by  the  567  de- 
coder whenever  it  sees 
1200  Hz.  On  the  fourth  re- 
set pulse,  indicating  the 
end  of  the  third  complete 
frame,  U4B,  pin  5  goes  low, 
bringing  one  end  of  the  .1 
uF  capacitor  connected  to 
it  to  ground.  This  in  turn  ap- 
plies a  momentary  ground 
to  pin  5  of  U3B,  resetting 
the  flip-flop,  and  pin  3  goes 
low.  When  pin  3  goes  low, 
Q2  stops  conducting,  and 
the  relay  drops  out,  stop- 
ping the  tape  recorder.  Pin 
3  of  U3A  also  pulls  pins  10 
and  13  of  U4  to  ground, 
resetting  the  flip-flops  to 
zero  and  disabling  them. 
At  the  same  time,  pin  3  of 
U3 A  pulls  one  end  of  the  .1 
uF  capacitor  connected  to 
pin  9  of  U3D  to  ground, 
thereby  applying  a  momen- 
tary ground  to  pin  9,  reset- 
ting the  flip-flop  U3C/U3D. 
Pin  n  of  U3C  goes  low  and 
disables  the  555  timer. 
The  LEDs,  placed  as  they 


are,  give  an  indication  of 
proper  circuit  operation 
for  maintenance  and  oper- 
ation of  this  unit.  One  set 
of  contacts  on  K1  removes 
SSTV  audio  from  the  tape 
recorder  when  its  remote 
input  becomes  disengaged 
by  the  synchronizer  so  as 
not  to  record  anything  dur- 
ing the  time  the  recorder  is 
coming  to  a  stop. 

Initial  Setup 

There  are  only  two  ad- 
justments to  be  made  to 
place  the  synchronizer  into 
operation  ^the  1200  Hz 
decoder  and  the  555  timer. 
The  1200  Hz  decoder  can 
be  set  up  in  one  of  two 
ways,  Method  #1  is  to  con- 
nect a  frequency  counter 
with  a  high-impedance  in- 
put between  pin  5  and 
ground  and  adjust  the  10k 
pot  connected  to  pin  6  of 
the  567  for  1200  Hz.  Meth- 
od #2  is  accomplished  by 
connecting  a  VOM,  VTVM, 
or  scope  to  pin  8  of  567. 
While  applying  an  accu- 
rate 1200  Hz,  adiust  the 
pot  mentioned  above  until 
you  see  the  meter  drop 
suddenly  to  zero.  You  will 
notice  a  small  amount  of 
play  in  the  rotation  of  the 
pot  between  the  points 
where  the  voltage  is  zero 
and  where  it  is  5  volts.  The 
pot  should  be  set  at  the 
middle  of  this  range.  The 
555  timer  is  set  up  by 
observing  the  LED  con- 
nected to  pin  3  of  the  555. 
Disconnect  the  500  pF 
capacitor  connected  to  pin 
3,  press  the  arm  button, 
and  the  arm  LED  should 
light.  Momentarily  short 
pin  2  of  the  555  to  ground; 
the  time  LED  should  light 
for  a  period  of  time  and 
then  go  out.  Adjust  the  1 
meg  pot  connected  to  pin  6 
of  the  555  so  that  the  light 
stays  lit  for  7  seconds. 
Reconnect  the  500  pF 
capacitor.  Initial  adjust- 
ment is  now  cornplete. 

Operation 

Connect  the  output  of 
your  SSTV  camera  to 
"SSTV    in"    on    the    syn- 


84 


chronizer,  or;  if  using  the 
Robot  4O0,  insert  a  picture 
into  the  memory  of  your 
scan  converter.  Connect 
the  output  of  the  scan  con- 
verter to  "SSTV  in"  on  the 
synchronizer.  Connect 
"SSTV  to  recorder"  to  the 
auxiliary  input  on  your 
tape  recorder.  Connect  "to 
recorder  remote"  to  your 
recorder  remote  jack.  Your 
recorder  motor  functions 
should  be  normal  (SI  off). 
Pul  SI  on,  and  note  that  the 
power  LED  lights.  Put  your 
recorder  into  the  record 
mode;  your  recorder 
motors  should  not  operate. 
Depress  the  arm  push-but* 
ton;  the  arm  LED  should 
lighL  The  very  next  1200 
Hz  reset  pulse  that  arrives 
should  light  the  time  LED. 
After  7  seconds,  the  time 
LED  goes  out  momentarily, 
the  record  LED  should 
light,  the  relay  should  pull 
in,  and  your  recorder 
should  start.  In  sequence, 
on  arrival  of  the  1200  Hz 


Close-up  of  the  per f board  and  core  wiring. 


Fig.  3.  PC  board. 


as 


Fig.  4.  Component  layout 


sync  pulses,  the  "1"  LED, 
the  ^'2"  LED.  and  both  the 
^'1"  and  "2"  LEDs  should 
light.  Eight  seconds  after 
the  "1"  and  "2"  LEDs  light, 
all  LEDs  except  the  power 
LED  should  go  out,  and  the 
recorder  will  stop. 

Comments 

Fig.   2   is   the  suggested 


panel  layout  for  the  syn- 
chronizer. Parts  layout  is 
not  critical  as  long  as  good 
wiring  practice  is  followed. 
All  parts  are  off-the-shelf 
items  available  at  most 
electronic  stores.  The  .068 
capacitor  connected  to  pin 
6  of  the  5676  decoder 
should  be  a  good  quality 
mylar   to  avoid   problems 


with   the  decoder  drifting 
off  frequency. 

Please  note  that  the 
photos  of  the  synchronizer 
are  of  the  prototype,  in 
which  perfboard  was  used 
to  build  the  circuit.  The  cir- 
cuit may  be  built  in  this 
fashion,  or  the  full-scale  PC 
layout  shown  in  Fig.  3  may 
be  used  instead.  If  the  PC 


layout  is  used,  a  suitable 
housing  will  have  to  be 
chosen  to  accommodate  it. 

My  sincere  thanks  and 
appreciation  go  to  Joe 
W7SI  for  the  photos  and  to 
Stan  K3ETN  for  the  PC 
layout.  Questions  regard- 
ing this  project  will  gladly 
be  answered  when  an  SASE 
is  included. ■ 


86 


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87 


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bands  (80*10  meters)  w^ith  any  transceiver 
running  up  to  800  watts  power  output. 

Increases  usable  bandwidth  of  any  antenna. 
Tunes  out  SWR  on  mobile  whips  from 
inside  you  rear. 

Uses  efficient  foroid  inductor  and  specially 
made  capacitors  for  small  size:  SV*"  ^  2H" 
x8H"-  Rugged,  yet  compact.  Negligible 
line  loss.  Attractive  bronze  finished 
enclosure.  SO-S139  coax  connectors  are  used 
for  transmitter  input  and  coax  fed 
antennas.  Convenient  binding  posts  arc 
provided  for  random  wire  and  ground 
connections. 


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89 


Receiver  Diseases 


and  how  to  cure  them 


Joseph  J.  Carr  K4IFV 
5440  South  8th  Road 
ArHngmn  VA  22204 


Two  identical  transceiv* 
ers  need  repairs.  One  is 
completely  dead  —  no 
sound,  no  lights,  nothing 
works.    The    other    works 


weil,  except  that,  on 
receive,  a  static-like 
''frying-eggs*'  sound  is 
heard  occasionally,  and  it 
is  capable  of  drowning  out 


all  but  S9+  signals.  Which 
of  these  will  be  the  hardest 
to  troubleshoot? 

Many    inexperienced 
troubleshooters    pick   the 


Photo  A,  Freon  cool  spray  (available  at  most  electronic  whotesalers)  will  cool  off  the  circuit  and  help  locale  bad  com- 
ponents. 


90 


dead  receiver/transceiver, 
probably  because  the 
symptoms  hint  at  some  cat- 
astrophic failure.  Dead  re- 
ceivers,  whether  the  dial 
lights  come  on  or  not,  are 
usually  relatively  easy  to 
troubleshoot.  Even  if 
smoke  has  rolled  out  of  the 
innards  (some  say  especial- 
ly), the  problem  of  locating 
the  faulty  part(s}  is  actually 
pretty  easy. 

It  IS  the  more  subtle 
problems  that  tend  to  snap 
your  mind  clean  out  of  its 
socket!  The  static,  pops, 
hisses,  and  miscellaneous 
oscillations  and  grum- 
blings that  a  defective  re- 
ceiver is  capable  of  gener- 
ating are  often  rather  dif- 
ficult to  pin  down,  espe- 
cially in  a  short  period  of 
time.  The  professional  ser- 
vicer  who  hears  a  customer 
making  such  a  complaint 
will  often  as  not  utter  a 
silent  "Oh,  no!"  and  say  a 
private  prayer  because  he 
knows  that  such  problems 
can  take  a  lot  of  time,  and 
there  is  a  limit  to  how 
much  of  a  labor  fee  the 
market  will  bear. 

In  this  article,  I  will  ex* 
amine  some  of  the  causes 
of  noises  and  the  trouble- 
shooting techniques  ap- 
propriate to  each  by  taking 
you  through  several  case 
histories.  These  troubles 
have  occurred  in  amateur, 
CB,  and  commercial  com- 
munications receivers, 
plus  a  few  million  times  in 
consumer  equipment,  so 
they  are  all  but  universal. 

Case  No*  1 
A  High-pitched  Whistle 

Some  years  ago,  I  had  to 
service  a  vacuum-tube  re- 
ceiver that  had  a  high- 
pitched  whistle  superim- 
posed on  the  audio  output. 
In  receivers,  this  could  be 
caused  by  any  number  of 
devilish  faults,  but,  in  this 
case,  it  was  relatively  easy 
to  pin  down  the  section  of 
the  receiver  at  fault  be- 
zause  the  noise  did  not  go 
jway  when  the  audio  gain 
:ontrol   was   set   to   mini- 


mum, tf  anything,  the  ap- 
parent amplitude  went  up 
because  of  an  improved 
signal-tcnnoise  ratio. 

The  trouble  in  this  case 
turned  out  to  be  in  the 
power  supply  powering  the 
audio  preamplifier  stages. 
A  panel-mounted  neon 
lamp  (Fig.  1)  was  used  as 
the  power-on  indicator, 
and  this  lamp  was  connect- 
ed into  the  dc  power  sup* 
ply,  rather  than  in  series 
with  a  150k-Ohm  resistor 
across  the  ac  line  as  is  nor- 
mally done.  The  circuit 
designer  apparently  tried 
to  gain  a  little  dc  voltage 
regulation  with  the  lamp, 
forcing  it  to  serve  a  dual 
function,  thereby  saving 
money. 

The  circuit  (Figl)  con- 
tained series  resistances  R1 
and  R2  to  drop  the  voltage 
to  the  level  required  by  the 
neon  bulb  and  to  limit  cur- 
rent through  the  bulb  so 
that  a  catastrophic  burn- 
out was  prevented. 

Capacitors  CI,  C2,  C3, 
and  C4  serve  to  decouple 
the  stages  being  powered, 
while  all  but  C3  also  serve 
to  filter  out  the  120-Hertz 
ripple  component  left  by 
the  rectifier.  Capacitor  C3 
is  of  a  lower  value  than  the 
others  and  is  usually  a  disc 
ceramic,  mica,  mylar,  or 
even  paper-type,  rather 
than  an  electrolytic. 

The  technique  of  using  a 
small-value  disc  ceramic 
capacitor  in  parallel  with  a 
high-value  electrolytic 
seems  ridiculous  on  first 
glance,  but  becomes  more 
valid  when  you  realize  that 
many  electrolytics  (espe- 
cial ly  older  types}  are  as  ef- 
fective as  a  block  of  wood 
at  higher  frequencies.  The 
low-value  capacitor  be* 
comes  necessary  even  in 
some  audio  amplifiers  and 
with  i-f  amplifiers  with  as 
low  as  a  50  kHz  operating 
frequency.  It  is  certainly 
most  advisable  if  the  stage 
powers  a  455  kHz  or  higher 
i-f  amplifier. 

In  the  receiver  with  the 
"high-pitched  whistle/'  the 
problem  was  that  C4  had 


tD  cmcuiTS 


Fig.  7.  An  amplifier  power  supply  using  a  neon  glow  lamp. 


opened  up  This  allowed 
the  now  undecoupled 
stages  to  go  into  a  low- 
frequency  motorboating 
oscillation  and  also  al- 
lowed I1-R2-C3  to  operate 
as  a  neon  relaxation 
oscillator.  The  frequency 
of  oscillation  is  set  by  the 
time  constant  of  R2'C3  and 
the  firing  potential  of  neon 
lamp  n.  The  symptom  was 
a  nauseating  combination 
of  a  whistle  modulated  by 
a  low-frequency  motor- 
boating  oscillation. 

Case  No.  2 
Noisy  Plate  Loads 

Many  amateur  receivers, 
as  well  as  other  equipment 
used  by  amateurs  both  in 
and  out  of  their  ham  radio 
hobby,  may  tend  to  devel- 
op a  sound  that  is  often 
typified  as  "frying  eggs"  or 
"sizzling,"  This  is  especial- 
ly prevalent  in  equipment 
that  is  allowed  to  take  on 
moisture  by  being  [often 
improperly)  stored  for  a 
long  time  in  a  humid  cli- 
mate. 

Some  amplifier  stages 
are  resistor/capacitor 
coupled,  so  the  plate  load 
resistor  of  the  first  stage  in 
a  cascade  chain  will  be  a 
resistor.  Still  other  ampli- 
fiers, such  as  the  rf  and  if 
amplifiers  in  the  receiver, 
are  coupled  through  tuned 
rf  transformers  (see  Fig.  2). 
In  either  case,  internal  arc- 


J'Ul 


ing  of  the  plate  toad,  be  it 
resistor  or  rf  transformer, 
will  be  propagated  through 
the  following  stages  as  a 
signal.  In  most  cases,  the 
result  is  the  classic  frying- 
eggs  sound  of  a  continuous 
arc,  or  thunder  crashes  of 
static  of  an  intermittent 
arc. 

In  a  mu!tiple-i-f  am- 
plifier receiver  or  multi- 
stage audio  amplifier,  this 
noise  can  be  a  little  dif- 
ficult to  locate,  but  a  little 
"trick  of  the  trade"  can 
reduce  the  agony.  In  the 
case  of  both  types  of  am- 
plifier, you  can  trouble- 
shoot  by  removing  the 
tubes  from  their  sockets 
one  by  one,  until  the  noisy 
stage  is  found,  A  replace- 
ment tube  will  usually 
eliminate  the  tube  from 
suspicion.  With  the  power 
turned  off  and  the  tube  out 
of  the  socket,  connect  a 
lOk-Ohm,  1-Watt  resistor  be- 
tween the  plate  pin  of  the 
tube  and  power  supply 
ground.  This  maneuver  will 
draw  "plate"  current 
through  the  load  resistor  or 
transformer  and  will  create 
the  frying-eggs  sound  if 
that  load  is  defective,  tf  no 
trouble  is  found,  go  to  the 
next  stage  back  toward  the 
input  and  repeat  the  pro- 
cedure. 

Of  course,  if  the  bad 
plate  load  is  a  resistor,  then 
it  should  be  replaced  when 


B 


T 
X 


u 


Fig.  2.  (a)  Vacuum  tube  t-f  amplifier  plate  circuit,  (b]  A 
lOk-Ohm,  1-Watt  resistor  to  ground  will  tell  the  tale. 


91 


FROM 


"-0    L 

V*i/       MAIN      1 • 


TUNING 

CI 

lOOpF 


T 

X 


'' 1 


F/g.  3.  H/grt  humidity  over  long  times  will  cause  the  trim- 
mer to  arc. 


found.  But,  in  the  case 
of  i-f  transformers,  it  might 
be  worth  attempting  to  re- 
pair—a luxurv  that  ama- 
teurs can  afford.  This  is  not 
merely  desirable,  but  be- 
comes mandatory  if  the  re- 
ceiver is  a  few  years  old  or 
the  manufacturing  com- 
pany is  no  longer  in  busi- 
ness. 

Very  carefully  pry  apart 
the  metal  tabs  holding  the 
shield  onto  the  transformer 
form  and  expose  the  coils 
and  capacitors.  Be  very 
careful  and  work  slowly, 
because  sometimes  the 
coil  form  has  adhered  to 
the  shield  and  will  be 
pulled  from  its  mounting 
if  the  shield  is  putled 
off  vigorously  before  the 
wires  and  form  are  freed. 
Carefully  examine  the  fine 
wires  with  a  tiny  screw- 
driver or  toothpick  to  see 
that  they  are  ac- 
tually soldered  to  the  wire 
tabs  or  i-f  can  terminals. 
Oddly  enough,  an  unsol- 
dered  joint  at  this  point 
may  work  for  years  before 
being  jarred  loose  or  be- 
fore an  oxide  layer  forms 
to  break  the  connection. 

Other  sources  of  prob- 
lems are  the  resonating 
capacitors  across  each 
coil.  If  they  are  disc 
ceramic,  tubular  ceramic. 
or  mica  types,  then  they 
may  be  easily  replaced. 
But  most  if  transformers 
use  a  fixed  mica  compres- 
sion capacitor  molded  into 
the  plastic  base.  There  is 
no  firm  advice  on  how  to 
repair  such  transformers. 
Try  finding  the  metal  tab 
leading  from  the  capacitor 


to  the  terminal  lug  to 
which  the  coil  is  soldered. 
In  most  cases,  it  wtll  ap- 
pear to  be  one  piece  with 
the  lug,  but  close  examina- 
tion reveals  that  it  is  ac- 
tually a  sandwich  assem- 
bly. If  you  can  cut  this  tab, 
even  if  a  little  of  the  plastic 
base  must  be  melted  to 
gain  access,  then  you  are  in 
luck.  Otherwise  try  form- 
ing a  new  terminal  in  one 
of  the  unused  spots  on  the 
mounting,  or  obtain  a  new 
transformer. 

Some  old-timer  elec- 
tronic supply  houses,  espe- 
cially those  with  a  large 
TV-shop  clientele,  may 
have  an  old  455-kHz  i-f 
transformer  for  sate.  Alter* 
natively,  find  a  dealer  (or 
mail  order  direct)  who  sells 
J.  W.  Miller  products.  They 
offer  a  line  of  i-f  trans- 
formers that  may  be  exact- 
ly what  is  required  or  can 
be  modified  to  meet  your 
needs  with  little  effort.  In 
fact,  it  is  possible  that  J.  W, 
Miller  made  the  original 
under  contract  to  the  re- 
ceiver manufacturer! 

Case  No.3 

Shorted  Trimmer 
Capacitors 

Fig.  3  shows  a  converter 
stage  [combination  mixer 
and  local  oscillator]  from  a 
mobile  receiver  made  sev- 
eral years  ago.  Transistor 
Ql  serves  as  both  the  local 
oscillator  and  the  mixer  in 
a  superheterodyne  design. 
Transformer  T1  is  the  i-f 
transformer,  while  coil  LI 
is  in  the  tuning  circuit  of 
the  oscillator,  along  with 
CI  and  C2.  Capacitors  C3 


and  C4  are  used  mainly  for 
bypassing. 

The  trimmer  capacitor 
(C2)  is  a  compression  mica 
variable  and  will  suffer 
from  the  same  problems  as 
the  fixed  mica  compres- 
sion capacitors  in  the  i-f 
amplifier.  These  will  occa- 
sionally arc  internally  des- 
pite the  relatively  low  volt- 
age applied  to  the  tran- 
sistor. The  result  is  the 
same  sort  of  frying-eggs 
sound  as  before,  but  it  is 
not  always  so  easily  found. 

In  this  case,  once  the  if 
transformer  and  LI  con- 
nections are  eliminated,  a 
0.01  uF  disc  capacitor  is  in- 
serted in  series  with  the 
trimmer  to  block  dc.  If  the 
arcing  disappears,  or  is 
significantly  reduced,  then 
replace  the  trimmer  capac- 
itor.  Do  not  be  tempted  to 
leave  the  apparently  re- 
stored capacitor  in  the  re- 
ceiver because  1)  dial  cali- 
bration is  now  incorrect 
and  2)  the  trimmer  will 
eventually  fail  more  and 
kill  the  set  The  trimmer 
was,  after  alf,  shorted,  if 
only  with  a  high  resistance. 

Case  No,  4 
Pn  Junctions 

Another  noise  source 
peculiar  to  solid-state  rigs 
is  any  pn  junction  that  be- 
comes reverse  biased.  In  a 
complex  circuit,  there  may 
be  several  such  junctions 
whose  loss  does  not  com- 
pletely  kill  the  receiver's 
operation,  so  noise  results. 

If  a  pn  junction  becomes 
reverse  biased,  it  can  pro- 
duce a  hiss-like  ''white 
noise."  This  phenomenon 
is  used  as  the  basis  for  a 
couple  of  popular  amateur 
antenna  bridges.  In  the  cir- 
cuit of  Fig.  4,  there  is  a 
noise  generator  made  from 
a  reverse-biased  pn  |unc- 
tionjn  this  case,  a  diode  If 
an  oscilloscope  with  a 
wideband  vertical  amplifi- 
er were  connected  across 
terminals  A-B,  you  would 
see  a  lot  of  "grass"  on  the 
CRT  screen. 

It    sometimes    happens 


® 


•  A. 


Fig.  4.  Diode  noise  gener- 
ator. 

that  faults  in  capacitors, 
changed  values  in  resistors, 
or    certain    other    circuit 

defects  can  cause  a  junc- 
tion to  become  reverse 
biased  without  completely 
upsetting  the  dc  operation 
of  the  rest  of  the  circuit 
Consider  the  circuit  of  Fig. 
5.  This  circuit  operates 
from  a  dual-polarity  power 
supply  in  which  Vcc  is  posi- 
tive to  ground  and  Vee  is 
negative  to  ground.  The  cir- 
cuit also  has  a  differential 
input  stage  in  which  the 
signal  is  applied  to  the 
base  of  transistor  Ql  A,  and 
the  operating  character- 
istics of  Ql  B  are  held  con- 
stant by  a  fixed  resistor  net- 
work. 

In  one  problem  involv- 
ing this  type  of  circuit 
capacitor  CI  became  leaky 
(not  a  direct  short  but  a 
high  resistance  short)  and 
that  substantially  reduced 
the  contribution  of  Vcc  ( + ) 
to  the  bias  voltage  appear- 
ing at  point  A.  This  caused 
the  base^emitter  potential 
of  Ql  B  to  become  re- 
versed, making  the  b-e 
junction  into  a  noise 
generator,  which  sees  Q1A 
effectively  as  a  common- 
base  amplifier  followed  by 
the  rest  of  the  high  gain 
stages  in  the  chain. 

Case  No.  5 

Noisy  Transistors 

There  is  a  possibility  that 
a  normally-biased  tran- 
sistor will  become  noisy 
and  drown  out  signals  b^ 
ing  received.  If  the  tran- 
sistor is  located  in  a  low- 
level  stage  close  to  the  in- 
put then  the  gain  of  the 
following  stages  makes  the 
problem  even  worse,  Most 
of  the  time,  the  noise  is  of 
the  familiar  frying-eggs 
variety  with  a  few  extra 


92 


i 


INPUT 


^\- 


r 


OUTPUT 


1  I — NW 


VBfl  M 


/?7 


/7? 


Fig.  5.  Transistor  wideband  preamplifier. 


pops  and  fizzes  thrown  in 
for  good  measure. 

Most  of  the  time,  the 
type  of  noise  I  am  talking 
about  is  sensitive  to  heat 
By  making  the  circuit  hot- 
ter, you  can  often  create 
the  noise  (almost  at  will), 
while  makiog  it  colder  will 
cause  the  noise  to  disap- 
pear for  awhile.  It  seems, 
though,  that  most  common 
thermal  troubleshooting 
techniques  cover  too  much 
area  of  the  circuit  at  one 
time. 

For  example,  take  the 
common  aerosol  freon 
'^circuit  cooler"  or  "freeze 
spray"  (see  Photo  A}  used 
by  many  professional  ser- 
vicers. It  can  help  pinpoint 
the  location  of  bad  com- 
ponents very  quickly,  if 
you  can  keep  from  spray- 
ing it  on  too  many  com- 
ponents at  once.  The  same 
holds  true  for  most  heat 
sources  used  by  servicers. 

What  is  needed  is  a 
means  for  concentrating 
the  cold  or  heat  on  one 
component  at  a  time.  One 
solution  is  the  use  of  one  of 
those  oversize  pieces  of 
"spaghetti''  tubing  that 
seems  to  be  in  everybody's 
junk  box  from  the  times 
when  a  ''universal''  assort- 
ment was  purchased.  Sim- 
ply cut  one  to  three  inches 
of  tubing  to  fit  snugly  over 
the  transistors  or  resistors 
under  suspicion.  If  cooling 
is  your  goal,  the  tubing 
allows  you  to  concentrate 


the  spray  only  on  the  sus- 
pect component. 

For  heat  treatment,  sim- 
ply place  a  small  incandes- 
cent pilot  lamp  (#47  for 
6-volt  and  #1 892  for  1 2-volt 
are  suitable)  in  the  open 
end  of  the  tubing,  and  con- 
nect it  to  a  battery  or  dc 
supply.  It  has  been  my  ex- 
perience that  truly  heat- 
caused  defects  will  show 
up  within  about  three  to 
five  minutes  under  the 
lamp.  Most  of  them  will 
succumb  to  the  increased 
heat  in  less  than  one 
minute. 

Case  No*  6 

"It  Goes  Dead  When  Hot 

(or  Cold)" 

A  solid-state  transceiver 
was  brought  in  for  repair, 
and  the  owner  complained 
that  it  worked  in  the  morn- 
ing, but  not  in  the  after- 
noon. This  problem  is  not 
actually  a  noise  problem, 
but  is  so  common  and  so 
closely  related  to  probtem 
number  5  that  it  bears 
some  attention. 

Solid-state  circuits  can 
be  quite  sensitive  to  the 
thermal  environment,  hot 
and  cold.  Normally  operat- 
ing transistors  will  operate 
over  a  wide  range  of  tem- 
peratures, but,  when  cer- 
tain defects  show  up,  then 
they  become  abnormally 
sensitive  to  changes  in 
temperature. 

During  the  summer,  your 
mobile  rig  might  work  prop- 


erly on  the  way  to  work  in 
the  morning,  but  when  re- 
turning home  in  the  late 
afternoon  will  simply  re- 
fuse to  do  anything  right. 
The  problem  is  that  the  car 
was  sitting  in  the  hot  sun 
all  day  long,  and  the  in- 
terior is  very  hot.  Until  the 
air  conditioner  cools  off 
the  rig,  the  problem  will 
remain.  One  car  manufac- 
turer's radio  division 
measured  the  interior 
temperatures  of  cars  sit- 
ting in  the  90°  F  (32°  C)  In^ 
diana  sun  for  four  hours  at 
almost160*^  F  (71  °C).  Mar- 
ginal solid-state  devices 
might  quit  working  under 
such  conditions. 

Winter  gets  in  its  licks, 
too.  A  complaint  is  some- 
times heard  that  the  rig 
does  not  work  until  the  car 
is  halfway  to  work.  By  that 
time,  the  car's  heater  has 
warmed  the  rig  up  to  a 
temperature  range  where  it 
will  work.  If  you  think  this 
is  a  problem  limited  to 
those  in  the  northern  states 
and  Canada,  then  keep  in 
mind  that  I  am  a  K4,  and  I 
have  seen  this  problem  on 
many  occasions. 

Both  problems  succumb 
to  the  same  troubleshoot- 
ing techniques  as  were 
used  to  find  noise  in  case 
number  5.  First,  heat  or 
freeze  spray  a  large  area, 
such  as  one  corner  of  the 
chassis  or  an  entire  printed 
circuit  board.  Co  to  suc- 
cessively smaller  areas  un- 
til you  are  at  the  compo- 
nent level. 

Case  No,  7 

Internal  Component 

Arcing 

Some  noises  can  show 
up  in  the  loudspeaker  as  a 
result  of  internal  arcing 
resistors,  capacitors,  trans- 
formers, and  the  like. 
These  can  be  miserably  dif- 
ficult to  find.  Even  when 
the  arcing  is  audible  to  the 
naked  ear,  without  the 
loudspeaker,  it  seems  to 
come  from  several  com- 
ponents at  once. 

One  effective  technique 
for    locating    the    arcing 


POWEfi    SUPPLY 
OR    BATTERY 


m 


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Fig.  6.  A  short  length  of 
"'spaghetti''  tubing  will  con- 
centrate heat  from  lamp  or 
mist  from  freeze  spray  on 
only  one  component  at  a 
time. 


component  is  to  use  a  long, 
thin  section  of  rubber  or 
neoprene  tubing.  Hold  one 
end  in  your  ear  while  using 
the  other  end  as  a  probe  to 
find  the  arcing  component 
The  tubing  will  transmit  a 
barely  audible  click  loudly 
to  your  ear. 

Actually,  where  possi- 
ble, 1  prefer  to  use  a 
modified  medical  stetho- 
scope for  this  purpose. 
Although  the  professional 
type  used  by  physicians 
and  intensive  care  nurses  is 
quite  expensive,  cheaper 
types  are  available  in  home 
"blood  pressure  kits"  and 
in  mail-order  catalogues 
such  as  Edmund  Scientific 
of  Barrington  N],  Even  one 
from  a  two-dollar  child's 
"play  doctor"  kit  will  be 
sufficient, 

If  you  use  a  medical 
stethoscope,  be  sure  to 
remove  the  metal  bell  or 
end  piece.  This  will  serve  to 
both  localize  the  source  of 
arcing  and  prevent  you 
from  getting  an  electrical 
shock  in  the  case  of  in- 
advertent contact. 

It  will  be  necessary  to 
scan  the  whole  component 
in  many  cases  because  the 
lumen  of  the  tubing  is  so 
small  that  the  device  be- 
comes very  directional.  In 
fact,  the  resolution  of  this 
technique  is  so  good  that 
you  can  often  tell  which 
end  of  a  paper  or  mylar 
capacitor  contains  the 
arc!  ■ 


93 


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R.  L.  DRAKE  COMPANY 


DRAKE 


© 


540  Richard  St.,  Miamisburg,  Ohio  45342 
Phone:  (513)  866-2421  *  Telex;  288^017 


P^  Reader  Service — see  page  323. 


95 


m^ 


Roy  Cawihon 

2580  Norcross-  Tucker  Road 

Apt.  95 

Norcross  GA  30071 


Autophasing  for  WEFAX 


preserve  your  mental  health 


This  article  will  intro- 
duce you  to  a  method 
of  automatically  position- 
ing the  sync  pulse,  or 
margin,  in  GOES  WEFAX 
pictures.  It  is  a  well-known 
fact  among  weather  satel- 
lite amateurs  that  one  can 
go  practically  nuts  trying 
to  manually  position  the 
margin  of  a  picture.  Even  if 
you  do  succeed  in  getting 
the  horizontal  sync  on  the 


left  edge  of  the  paper,  the 
strain  on  one's  nervous 
system  is  simply  too  great. 
Inevitably,  the  phasing 
period  at  the  start  of  the 
picture  just  seems  too 
short. 

Before  1  gave  up  hope,  I 
got  the  idea  of  making  the 
machine  phase  itself.  After 
all,  why  shouldn't  the 
machine  do  all  the  work? 
With  that  thought  in  mind, 


Photo  A.  Photograph  of  the  author's  drum  recorder.  Note 
the  position  of  the  solenoid.  The  magnet  is  epoxied  to  the 
left  side  of  the  drum.  The  forward  and  reverse  limit  relays 
are  in  the  back  corner.  They  remove  power  from  the  lamp 
carriage  when  a  forward  or  reverse  limit  i$  sensed.  Also, 
they  light  a  corresponding  indicator  on  the  panel  below 
the  recording  head. 


the  following  circuits  were 
developed.  The  schematics 
appear  in  Figs.  1-5.  The 
result  was  a  phasing  circuit 
that  has  proved  that  it  can 
easily  place  the  picture 
sync  in  the  same  spot  each 
time  a  photo  is  made.  This 
will  help  any  operator's 
blood  pressure  remain  nor- 
mal while  he's  using  his 
facsimile  machine. 

Take  a  look  at  Fig.  1 ,  This 
circuit  has  the  function  of 
a  simple  comparator.  As 
the  picture  drum  rotates,  a 
small  alnico  magnet  is  at- 
tached to  the  drum  so  that 
it  passes  close  by  a  small 
relay  solenoid  on  each 
revolution.  The  resulting 
pulse  of  current  is  used  to 
operate  a  transistor  switch. 
Transistor  Q1  squares  up 
the  pulse  and  inverts  it. 
Also,  Q1  clamps  the  pulse 
to  TTL  voltage  levels.  You 
must  make  sure,  however, 
that  you  have  enough 
voltage  coming  from  the 
solenoid  to  forward  bias 
Q1.  It  may  be  necessary  to 
move  the  solenoid  closer 
to  the  magnet  With  Q1 
operating,  U1 A  restores  the 
pulse  to  its  original  phase 
relation  and  drives  J1  and 
also  U2,  pin  1. 

If  there  were  a  sheet  of 


photographic  paper  on  the 
drum,  and  you  had  its  edge 
at  the  centerltne  of  the 
magnet,  would  not  the 
pulse  from  U1A  mark  the 
edge  of  the  paper?  Unfor- 
tunately, this  is  not  true. 
There  is  some  phase  shift 
introduced  by  the  magnet 
and  solenoid  arrangement. 
You  could  put  in  a  variable 
phase  shifting  network 
befo're  Q1  to  counteract 
this,  but  it  is  much  easier  to 
simply  measure  the  shift 
and  offset  the  paper  edge. 
This  need  only  be  done 
once,  and  a  permanent 
mark  can  be  placed  on  the 
drum  corresponding  to  the 
picture  edge.  I  will  discuss 
later,  in  the  calibration  pro- 
cedure, just  how  this  is 
done.  For  now,  let's  assume 
the  pulse  from  U1 A  is  coin- 
cident with  the  picture 
edge. 

The  other  input  to  U2  is 
the  sync  pulse  transmitted 
during  the  WEFAX  phasing 
period.  Connector  J2  is  at- 
tached to  Fig.  5's  U4B,  pin 
7,  in  my  article  ''Attention, 
Weather  Watchers!  —  ad- 
vanced circuitry  for 
WEFAX  processing"  (7J, 
October,  1978).  The  signal 
on  U4B,  pin  7  is  the  output 
of   the  1700   Hz    low-pass 


96 


video  filter.  During  the 
GOES  WEFAX  picture 
piiasing  period,  the  white 
set  pot,  R52,  is  set  to  give  a 
pulse  rising  from  —  .5  V  dc 
to  ground  at  U4B,  pin  7. 
This  wi!l  be  the  correct 
white  current  setting  for 
the  GOES  WEFAX.  Mean- 
while, back  in  Fig.  1,  U3A 
accepts  the  —.5  V  dc-to- 
ground  sync  pulse  and  buf- 
fers it  The  second  section 
of  U3,  U3B,  converts  the 
sync  pulse  into  a  TTL- 
compatible  waveform. 

Now,  we  can  finally  talk 
about  U2.  IC  U2  has  only 
one  purpose  in  life.  Its  out- 
put sits  high  as  long  as  the 
sync  pulse  in  the  WEFAX 
phasing  period  and  the  pic- 
ture edge  pulse,  from  U1  A, 
are  not  overlapping  in 
time.  Assume,  for  the  mo- 
ment, that  the  picture 
drum  is  turning  in  phase 
lock  with  the  satellite 
video.  Usually,  some  time 
difference  exists  between 
the  actual  picture  edge 
and  the  satellite  sync 
pulse.  This  indicates  that 
the  picture  is  not  phased 
properly.  If  an  error  in  time 
exists,  U2,  pin  3  is  high.  I 
call  this  a  phasing  error.  If 
U2,  pin  3  happened  to  be 
low,  the  picture  phase 
would  be  okay. 

If  U2,  pin  3  is  high,  you 
need  some  way  of  reducing 
the  time  difference  be- 
tween the  two  pulses  to 
zero.  One  way  is  to  slightly 
reduce  the  frequency  of 
the  phase  locked  60  Hz  go- 
ing into  Ml  in  Fig.  1.  If  this 
happens,  the  picture  edge 
pulse  on  U2,  pin  1  will 
slowly  drift  or  roll  when 
compared  with  the  WEFAX 
phasing  period  pulse  at  U2, 
pin  2.  Eventually,  the  two 
pulses  will  cross,  and  both 
inputs  to  U2  are  high.  At 
this  moment  Ml  must  be 
phase  locked  back  on  the 
satellite  subcarrier  so  that 
the  picture  edge  will  drift 
no  further.  The  phasing 
would  then  be  accom- 
plished. 

The  method  of  reducing 
the  speed  of  Ml  slightly  is 
seen  in  Fig,  2.  I  use  a  pro- 


Photo.  B.  This  is  an  inside  view  of  the  unit  seen  below  the  recorder  head  in  Photo  A,  The 
two  cards  at  the  right  front  are  the  auto-phasing  circuits.  The  S1-1025E  power  amp  is  on 
the  heat  sink  in  the  right  corner.  The  transformer  in  front  of  it  is  77.  A  300  V  dc  power  sup- 
ply for  the  R1 1-68  is  on  the  subchassis  and  it  uses  five  tubes.  The  five-inch  fan  at  the  back 
keeps  things  cool.  My  video  processing  circuits  are  built  on  the  four  cards  at  the  leftside 
of  the  chassis.  The  meter  is  the  lamp  current  indicator. 


grammable  divider  to  con- 
trol the  speed  of  Ml,  ICs 
U5   and   U6  comprise  the 


divider.  The  divider  is 
capable  of  dividing  the 
2400    Hz    reference,   from 


Fig,  4,  by  40  or  41 .  Normal- 
ly, when  the  picture  phase 
is  okay,  U2,  pin  3  is  low. 


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7400 


OFFSET    ADJUST 
20K 


+IS 


Ji 


-'Vy^ 


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11 v.J'^tUU       P. 


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+  5 

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U4b    PIN    7 
SEE    TEXT 


1 


Fig.  1.  Sync  comparator. 


97 


FROM  FIG     I 


PHASING 
ERROR    LEti 


_El  MANUAL    PHASE 

"3, 


FROM    F3G     4 


1^     60    Hi    or 
|C>  56-536     Kz 
i>^    TO    FIS    3 


This  sets  the  Q-output  on 
ffip-flop  U4A  to  one.  The 
phasing-okay  LED,  CR1, 
now  lights,  and  the  correct 
bi-quinary  word  is  loaded 
into  the  divider  to  do  divi- 
sion by  40.  U6,  pin  8  now 
supplies  a  60  Hz  locked 
reference  to  the  low-pass 


Fig.  2.  Programmabte  divider. 

filter  in  Fig.  3  and,  in  turn, 
to  the  motor  amplifier. 

As  soon  as  the  WEFAX 
phasing  period  starts,  it  is 
necessary  to  test  the  pic- 
ture phase.  At  this  mo- 
ment, the  start  button,  S3, 
is  depressed  and  flip-flop 
U4A     is     cleared.     The 


phasing-effort  LED  will 
now  come  on,  and  the  pro- 
grammable divider  is  in- 
structed to  divide  by  41. 
The  picture  edge  pulse 
begins  to  drift  slowly  now 
with  respect  to  the 
reference,  since  the  drum 
slowed    down.    The    drum 


*^'  nzz  ^^ 


\ w^ V J[ _. 


FROM    FIG     2 


TO    FiG.  I 


TO   FtG.   I 


TO  FlO    \ 


98 


n 


Fig.  3.  70  Hz  low-pass  filter  and  power  amplifier. 


motor  is  now  running  at 
58336  Hz.   IC   U2   is  now 

looking  for  the  time  when 
the  two  pulses  will  cross. 
The  frequency  of  58.536 
Hz  provides  a  slow  enough 
drift  so  that  the  two  pulses 
do  not  happen  to  miss  each 
other.  Also,  it  is  slow 
enough  so  that  the  results 
obtained  are  repeatable. 
That  is,  it  puts  the  margin 
in  the  same  place  each 
time.  As  soon  as  the  two 
pulses  cross,  U2,  pin  3 
switches  low  and  U4A  is 
set  The  phasing-okay  LED 
now  comes  on,  and  divi- 
sion by  40  is  loaded  again 
into  the  divider.  The  syn- 
chronous motor,  M1\  jumps 
extremely  fast  to  the  prop- 
er speed  so  that  the  margin 
remains  properly  phased. 

You  now  have  the  pic- 
ture phasing  accomplished 
with  a  minimal  amount  of 
work  on  your  part.  Perfec- 
tionists should  be  able  to 
eliminate  the  start  button 
by  utilizing  a  300  Hz  band- 
pass  filter  to  detect  the  pic- 
ture start  tone.  This  start 
tone  immediately  precedes 
the  phasing  period.  The 
filter  could  feed  a  peak 
detector  and,  in  turn, 
charge  a  capacitor.  Next, 
the  voltage  on  the 
capacitor  could  be  sensed 
by  a  voltage  comparator 
and  used  to  fire  a  one-shot. 
The  one-shot  could  control 
U4,  pin  13.  I  haven't  incor- 
porated this  into  my 
system,  since  I  have 
chosen  not  to  eliminate 
myself  entirely  from  the 
process. 

Now,  suppose  t  had 
chosen  to  manually  phase 
the  picture,  or,  for  some 
reason,  I  missed  the  phas- 
ing period.  The  phasing 
switch,  S2,  is  set  to  manual. 
The  manual  phase  button, 
S4,  xs  simply  held  de- 
pressed. At  this  point,  a 
monitor  oscilloscope  is 
necessary.  The  scope  must 
have  its  timebase  set  to  250 
ms,  and  then  it  must  be  ex- 
ternally triggered  by  the 
pulse  on  J1,  Also,  the 
satellite  video  is  supplied 
to    the    scope's    vertical 


Photo  C  This  is  an  overall  view  of  the  author's  GOES 
WEFAX  station.  The  scope  on  the  top  is  a  customized 
Tektronix  5616.  !t  is  used  in  conjunction  v^ith  the 
Tektronix  C-27  camera  to  make  4  by  5  Polaroid^^  prints  of 
WEFAX  pictures.  The  tape  deck  is  seen  in  the  rack  below 
the  561.  Below  the  tape  deck  is  the  drum  recorder  in  its 
protective  enclosure.  The  door  opens  down  and  the 
machine  slides  out  The  scope  below  this  is  used  as  a 
waveform  monitor  ft  is  used  for  manual  phasing  and 
checking  signal  quality.  Betow  the  monitor  is  the  machine 
that  powers  the  drum  recorder  head.  It  does  the  video  and 
sync  processing.  Also,  it  contains  the  power  amplifiers  for 
the  motors.  My  receivers  are  housed  in  a  separate  rack  and 
were  not  shown  here.  I  use  a  200-channel  synthesized 
radio  for  136-138  and  a  double-conversion  custom-built 
receiver  for  GOES. 


amplifier.  The  scope 
screen  now  depicts  what  is 
happening  on  the  paper 
drum  one  line  at  a  time.  If 
the  position  the  sync  pulse 
takes  during  auto-phase  is 
known,  you  can  manually 
move  it  there  now  by 
holding  down  the  manual 
phase  button,  S4.  When  the 
pulse  arrives  on  its  desired 
position,  S4  is  simply 
released. 

Finally,  the  input  fre- 
quency for  the  program- 
mable divider,  U5,  pin  6,  is 
generated  in  Fig,  4.  To 
begin,  a  2.4  MHz  oscillator 
module  was  purchased 
from  International  Crystal 
Mfg.  Co.  The  2.4  MHz  TTL 
square  wave  is  buffered  by 


UIDandUIE.  ICsUg,  UIO, 
and  U11  divide  the  2.4 
MHz  down  to  2400  Hz. 
During  real-time  operation, 
the  2400  Hz  is  fed  directly 
to  the  programmable  di- 
vider by  S5.  Also,  it  may  be 
recorded  on  tape  via 
capacitor  C39  for  playback 
later.  During  playback,  the 
2400  Hz  that  was  recorded 
on  tape  locks  up  U12.  U12 
is  a  phase  locked  loop  chip 
that  has  its  vco  adjusted  to 
free  run  on  2400  Hz  by  R29. 
The  purpose  of  U12  is  to 
compensate  for  any  speed 
variation  in  the  tape  deck 
and  also  to  provide  a  clean 
signal  for  the  program- 
mable divider. 

There  you  have  it;  you 


now  have  a  complete  State- 
of-the-art  phasing  system 
for  the  new  GOES  WEFAX 
broadcasts. 

Calibration  Procedure 

First  of  all,  check  the  wir- 
ing before  applying  power. 


These  circuits  should  work 
the  first  time  if  the  wiring  is 
okay.  After  giving  every- 
thing a  thorough  going 
over,  turn  on  the  power 
supply.  Check  to  see  that 
the  voltage  levels  are  cor- 
rect and  that  the  ripple  is 


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TAPE 


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Fig.  4.  Sync  generator. 


99 


Photo  D.  This  is  an  example  of  a  properly  phased  GOES  WE  FAX  picture.  It  was  received 
and  processed  by  the  equipment  /n  Photo  C 


low.  The  ripple  should  only 
be  several  mV  p-p.  Next, 
measure  the  voltage  be- 
tween Ue,   pin  1    and  Ufl, 


pin  4.  With  R23  adjusted 
fully  CCW,  the  voltage 
should  be  about  50  V  dc. 
Now,    connect    a    dc-cou- 


T3 

TRIAD 
ON        BLK/YEL     F'9£A  ^pf,^ 


CR5 
V&-644 


<-^ 


115  VAC  > "1 

) 


S2 

ON       BLK/qED 


^  VEL 


1 


fiEO 


t1( 


C2& 

IIOO^F 


^ 


-15 


T     C30 


IJI4 


m 


B 


C2e 

50V 


^hr 


fh 


+15 
1. 


X 


C52 


/77 


fl 


X 


C34 

'p*  .47itF 


1 


/77 


C35 
50V 


UI7 
MC7805 


m 


C36 
.47^F 


Fig.  S.  Power  supply. 


pled  scope  to  U11,  pin  12 
and  check  for  a  2400  Hz 
square  wave.  Connect  a 
counter  to  UlE,  pin  10 
and  check  the  oscillator, 
OSC-1,  for  2.400,000.0  Hz. 
Move  the  counter  over  to 
UIF,  pin  12,  and,  with  S5  in 
real  time  and  j4  discon- 
nected, adjust  R29  for  2400 
Hz.  Switch  S2,  the  phasing 
switch,  to  manual  and  con- 
nect the  counter  to  U6,  pin 
8.  You  should  read  60  Hz. 

Next,  depress  the  manu- 
al phase  button,  and  the 
counter  should  read  58.536 
Hz.  This  checks  the  divider* 
Release  the  manual  phase 
button  and  connect  a 
VOM,  on  a  high  ac  voltage 
range,  across  the  blue  and 
brown  wires  on  the  second- 
ary of  T1.  Adjust  R23  CW 
until  117  V  ac  is  read  on  the 
meter.  Ml  should  now  be 


running.  Next,  move  your 
dc-coupled  scope  to  the 
base  of  Q1.  Check  the  am- 
plitude of  the  pulse  from 
the  magneto.  You  need  at 
least  1  voit  peak  to  ensure 
that  Q1  turns  on.  The 
positive  half  cycle  will  for- 
ward bias  Q1.  If  the  pulse 
level  is  too  low,  move  the 
solenoid  in  closer  to  the 
magnet.  Move  the  probe  to 
the  collector  and  check  for 
a  TTL  pulse  of  approx- 
imately 10  ms  duration. 
The  inversion  of  this  pulse 
will  be  on  )1. 

It  is  now  necessary  to 
use  a  GOES  WE  FAX  signal. 
A  prerecorded  signal  will 
be  desirable.  With  the  cir- 
cuits  completed  and  test- 
ed, as  described  in  '^Atten- 
tion, Weather  Watchersl", 
connect  J2  to  U4B,  pin  7  in 
the  video  filter.  Switch 
both  function  switches  to 
playback,  start  the  tape, 
and  adjust  the  white  set 
pot  for  a  pulse  that  rises 
from  —.5  V  dc  to  ground 
during  the  phasing  period 
at  U4B,  pin  7.  Next,  adjust 
R5  in  Fig.  1  for  a  zero-to- 
five-volt  pulse  on  U3B,  pin 
7.  Finally,  with  52  in  auto, 
start  the  tape  at  the  begin- 
ning. The  phasing-okay 
LED  should  be  on  as  the 
drum  spins.  As  soon  as  the 
phasing  period  starts, 
check  the  picture  phasing 
by  pressing  the  start  but- 
ton. The  error  LED  will  now 
come  on  and  will  remain 
on  until  the  two  pulses 
cross.  When  the  two  pulses 
cross,  the  phasing-okay 
LED  will  come  on,  indicat- 
ing that  phasing  was  ac- 
complished. 

1  mentioned  earlier  that 
there  is  a  phase  shift  in- 
troduced by  the  magnet 
and  the  coil  that  offsets  the 
true  picture  edge  about  an 
inch  or  so.  The  easiest  way 
to  correct  this  is  to  find  the 
point  on  the  drum  that  cor- 
responds to  the  actual  pic- 
ture edge.  To  do  this,  you 
will  need  to  load  the  drum 
with  photographic  paper 
and  place  the  paper's  edge 
in  line  with  the  magnet's 
centerline.  Now,  start  the 


too 


Parts  List 

CI 

.1  uF,  50  V  monolytic  (mono) 

R14 

C2 

.1  uF,  50  V  mono 

R15 

C3 

.71  uF.  100  V  mylar* 

R16 

04 

,065  uF,  100  V  mylar* 

R17 

C5 

1.46  uF.  100  V  mylar* 

R18 

C6 

.024  uF,  100  V  mylar* 

R19 

07 

Zm  uF,  100  V  my  far* 

R20 

C8 

,1  uF,  50  V  mono 

R21 

C9 

A  uF,  50  V  mono 

R22 

C10 

I.OuF,  50  Vmono 

R23 

011 

2200uF,  50  V  electrolytic 

R24 

012 

50  uF,  50  V  electrolytic 

R25 

013 

.047  uF.  1D0V  mylar 

R26 

014 

3450  uF,  75  V  electrolytic 

R27 

CI  5 

.5  uF,  400  V  (supplied  wfth  M1) 

B28 

016 

,1  liF,  50  V  mono 

R29 

017 

J  uF,  50  V  mono 

R30 

018 

.1  uF,  50  V  mono 

R31 

019 

.047  uF,  100  V  10%  myJar 

R32 

020 

.1  uF,  50  V  mono 

R33 

021 

,1  uF,  50  V  mono 

R34 

022 

.1  uF,  50  V  mono 

R35 

023 

.001  uF,  50  V  mono 

R36 

024 

250  uF,  25  V  electrolytic 

R37 

025 

1100  uF,  50  V  electrolytic 

R38 

026 

1100uF,  50  Vefectrolytic 

R39 

027 

.016uF,  10%  myiar 

R40 

028 

,47  uF,  50  V  mono 

R41 

029 

.033  uF,  50  V  10%  myiar 

R42 

C30 

100  uR  50  V  electrolytic 

R43 

031 

1500  pF  5%  silver  mica 

R44 

032 

100  uF,  50  V  electrolytic 

R45 

033 

,O47uF,5OVl0%  myJar 

R46 

034 

.47  uF,  50  V  mono 

R47 

035 

too  uF,  50  V  electrolytic 

R4a 

036 

-47  uF,  50  V  mono 

SI 

037 

-1  uF.  50  V  mono 

S2 

038 

573  pF  in  parallel  with  12  pF  5%  stiver  mica 

S3 

039 

1.0  uF,  50  V  mono 

S4 

040 

.1  uF,  50  V  mono 

S5 

041 

.1  uFj  50  V  mono 

T1 

042 

I.OuF,  50  V  mono 

T2 

043 

5  uF,  25  V  electrolytic 

T3 

CR1 

1.7  V,  20  mA  LED 

T4 

CR2 

1.7  V,  20  mA  LED 

CR3 

VS-644  bridge  rectifier  assembly,  600  V  #  2  A 

U1 

CR4 

1 N93TA 

U2 

CR5 

V&-644 

U3 

F1 

1  Amp  siow  blow 

U4 

J1 

BNO  female  chassis  mount  connector 

US 

J2 

6N0  female  chassis  mount  connector 

U6 

J3 

BNO  female  chassis  mount  connector 

U7 

J4 

BNO  lema  e  chassis  mount  connector 

US 

M1 

240  rpm  5-Watt  synchronous  Hurst  motor  model  CA 

Q1 

2N2270 

U9 

Q2 

2N2270 

U10 

03 

2N2270 

U11 

R1 

680  Ohm,  %  W10% 

U12 

R2 

Ik  Ohm,  V4  W10% 

U13 

R3 

47  Ohm,  V4  W  10% 

U14 

R4 

47  Ohm,  V*  W  10% 

U15 

R5 

20k  1-Watt  wire- wound  20-tum  PC  pot 

U16 

R6 

100k,  V*  W  10% 

U17 

R7 

10k  RN55  1  % 

uie 

R8 

10k  RN551% 

0SC1 

R9 

90.9k  RN551% 

RIO 

3,3k,  %  W  10% 

R11 

220  Ohm,  V4  W  10% 

R12 

10k  Ohm,  %  W10% 

R13 

10k  Ohm,  V4  W  10% 

3.3k,  Va  W  10% 
3.3k,  V*  W  10% 

10k  RN55  1% 

10k  RN55  1% 

l0kRN55l% 

10kRN55  1% 

10k  BN55  1.% 

47  Ohm,  %  W  10% 

47  Ohm,  V*  W  10% 

10k,  1  W  wire-wound  20-turn  pc  pot 

10  Ohm,  %  W  10% 

464  Ohm  RN60  1% 

22k,  %  W  10% 

4.7k,  V*  W  tO% 

4,7k,  V4  W  10% 

5k  Ohm,  1  W  wire-wound  20- turn  pc  pot 

3.3k  Ohm,  V*  W10% 

3,3k  Ohm,  V4  W  10% 

10k  RN55  1% 

10kRN55  1% 

l0kRN55l% 

10k  RN55  1% 

10k  RN55  1% 

50k.  1  W  wire-wound  20-turn  pc  pot 

33k,  Va  W  10% 

Ik,  V4  W  10% 

47  Ohm,  V*  W  10% 

47  Ohm,  y-  W  10% 

660  Ohm,  V*  W  10% 

too  Ohm,  V4  W  10% 

47k,  %  W  10% 

10k,  V*  W  10% 

10k,  V4  W  10% 

47  Ohm.  V*  W10% 

47  Ohm,  V4  W10% 

SPDT  120  V  toggle 

DPDT  120  V  toggle 

SRST  push-button 

SPST  push-button 

SPDT  toggle  or  rotary  switch 

TRIAD  S-24A  8-Ohm^t0^8k'Ohm,  15  W 

TRIAD  F-93X 

TRIAD  F-92A 

solenoid  from  a  relay— I  use  a  coil  from  a  model 

KRP11AG  Potter  and  Brumfteld. 

SN7404 

SN7400 

M01458 

SN7474 

SN74196 

SN74196 

MCI  458 

Sanken  S1-1026E  hybrid  power  JO.  An  SM020  is  a 

good  substitute. 

SN7490 

SN  7490 

SN7490 

LM565 

MCI  458 

MC7915CP 

LM741 

M078150P 

MO7805OP 

SN7430 

International  Crystal  Mfg.  Co.  OE*l  oscillator  module. 

'The  desired  value  is  obtained  by  paralleling  two  or 
more  capacitors.  Use  a  good  quality  capacitor.  The 
value  doesnH  have  to  be  exactly  on  the  calculated 
value  shown. 


101 


drum,  turn  on  the  tape 
deck,  and  wait  for  the  phas- 
ing period  to  start.  As  soon 
as  it  begins,  depress  the 
start  switch  and  allow  the 
machine  to  phase.  Next, 
switch  on  the  lamp  and 
allow  part  of  the  picture  to 
expose.  Remove  the  paper 
and  develop  it.  Note  the 
position  of  the  sync  on  the 
paper.  Place  the  developed 
picture  back  on  the  drum 
the  same  way  it  came  off. 
Make  a  small  mark  on  the 


drum  corresponding  to 
where  the  sync  is  on  the 

paper.  Remove  the  paper 
and  scribe  a  line  on  the 
drum  where  the  mark  is. 
This  line  is  to  be  used  to  in- 
dicate where  the  paper's 
edge  will  go  from  now  on 
each  time  the  drum  is  load- 
ed. 

Load  the  drum  with  a 
fresh  sheet  of  paper  and 
place  its  edge  along  the 
new  line.  Remake  the  tape- 
recorded    picture    once 


more.  Allow  the  drum  to 
phase  automatically.  This 
time  when  the  phasing  is 
accomplished,  the  sync 
will  be  positioned  at  the 
edge  of  the  photo.  If  you 
make  pictures  in  the  re- 
verse direction,  a  phasing 
mark  will  have  to  be 
located  for  the  opposite 
direction,  also.  To  do  this, 
the  above  process  will 
have  to  be  repeated.  When 
you  finish,  there  will  be 
one  mark  on  the  drum  for 


pictures  made  in  the  for- 
ward direction  and  one  for 
the  reverse  direction. 

Please  take  careful  note 
of  the  photos  showing  my 
station.  Details  of  the 
solenoid  and  magnet  may 
be  seen  in  the  picture  of 
the  recorder.  Good  luck  in 
getting  your  system  on  the 
air.  If  you  have  come  this 
far,  I  am  sure  you  have 
quite  a  station  by  now  tf 
you  have  any  questions, 
please  include  an  SASE. 


from  page  1$ 

suggest  an  imaginative  and 
potentially  beneficial  public 
service  television  concept  and 
that  this  type  of  communica- 
tions activity  is  one  which 
deserves  considerable  atten- 
tion in  the  overall  inquiry." 

The  FCC  requested  com- 
ments in  BC  Docket  No.  78-253 
from  all  interested  parties. 
These  comments  are  due  (orig- 
inal and  six  copies)  at  the  FCC. 
Washington  DC  20554,  by  De- 
cember 11,  1978. 

S,e.  PI  Her  W2K  PQ 

President 
Communlcasting  Association 

of  America,  Inc. 
Syosset  NY 


FRESH  VIEWPOINT 


] 


Being  an  active  amateur  for 
three  years  and  hoping  to  be 
one  for  at  least  another  thirty,  I 
feel  inclined  to  respond  to  your 
crilicism  of  the  ARRL  From  my 
Novice  days  on,  I  have  been 
brought  up  on  the  thinking  and 
ways  of  the  League.  On  the 
whole,  this  organization  has 
been  superb  in  helping  me 
grow  in  the  hobby.  Many  new 
things  have  come  about,  and 
ham  radio  is  still  around 
because  of  the  League, 

At  this  point,  the  accolades 
end  and  the  real  essence  of  my 
correspondence  surfaces,  fn 
the  beginning,  you  and  your 
magazine  really  rubbed  me  the 
wrong  way,  and,  as  usual,  I 
merely  discarded  your  com- 
mentaries. Well,  I  guess 
everyone  grows  up,  and  after 
many   hours   of    mental    soyt- 


searching  and  objective 
meditation,  I  finally  saw  the 
light. 

Mr.  Green,  thank  you  very 
much  tor  providing  about  the 
only  fresh  viewpoint  in  a  too- 
long  monopolized  field.  It 
seems  that  we  hams  have 
become  far  too  complacent  in 
our  thinking.  This  is  undoubted- 
ly a  very  dangerous  and  un- 
healthy situation. 

Although  there  are  points  of 
disagreements  in  our  thinking, 
at  least  you  have  spurred  my 
mind  to  realize  the  presence  of 
other  possibilities.  I  now  read 
the  rebuttals  you  receive  from 
other  hams  and  can  see  the 
fear  I  once  experienced,  I  can 
onJy  urge  ail  my  counterparts  to 
just  stop  for  a  few  minutes  and 
examine  their  way  of  thinking. 

Ham  radio  is  going  through 
an  amazing  period  of  change 
and  growth,  and  it  certainly 
needs  more  than  one  voice  to 
express  its  needs,  I  personally 
wish  you  good  luck  in  your  at- 
tempts concerning  the  upcom- 
ing WARC.  and  thanks  again, 

Michael  A.  Roscoe  K3VK 

Sharon  PA 


ATLAS  CLASS 


J 


in  the  past,  you  Ve  printed  let- 
ters from  WA5TUM  and  AA6US 
commending  Atlas  Radio  and 
their  service.  All  I  can  say  atK>ul 
Atlas  service  is.  'TANTASTIC,'* 

On  September  20.  my  Atlas 
350-XL  became  inoperative.  I 
called  Clint  Call  at  Atlas  and, 
after  describing  the  problem, 
Clint  told  me  to  send  the  350-XL 
and  p/s  to  Steve  Grossman  at 
Communications  Specialties  in 


Erie  PA.  collect.  The  units  were 
shipped  via  UPS  that  day  and 
on  September  27  at  6:30  pm,  my 
3SOXL  was  back  on  the  air  at 
my  QTH.  Not  only  was  the  rig 
repaired,  but  it  was  updated 
with  the  latest  modifications, 
all  for  no  cost  or  shipping 
charges. 

I  can't  praise  all  of  the  per- 
sonnel at  Atlas  too  much,  as 
they  are  not  only  gracious,  but 
helpful  to  the  nth  degree.  Atias 
Radio  is  setting  a  precedent 
and  building  up  a  reputation 
that  is  going  to  be  hard  to  beat. 

Now,  a  few  words  about  73. 
It's  in  a  class  by  Itself,  Were  it 
not  for  73,  K2QHI  would  have 
been  relegated  to  "appliance- 
operator"  status  a  long  time 
ago,  but  the  plethora  of  con^ 
struction  articles  keeps  my 
hands  t>usy  and  my  soldering 
irons  hot.  Keep  up  the  good 
work,  Wayne. 

Michael  Stefanik  K2QHI 

Garfield  NJ 


WHICH  MAGAZJNE? 

After  reading  the  letters  in  a 
few  of  the  past  issues.  I  feel 
compelled  to  write  in  answer.  I 
have  subscribed  to  both  73  and 
QST  for  the  past  three  years, 
and  wish  to  ask  (and  answer)  a 
few  questions  about  these  pub- 
lications: 

In  which  magazine  can  you 
find  the  most  useful  articles, 
divergent  points  of  view,  letters 
printed  on  both  sides  of  a  ques- 
tion^  letters  attacking  the 
magazine  as  well  as  praising 
it?  in  73.  In  which  will  you  find  a 
publishing  philosophy  which 
accepts  opposing  points  of 
view,  which  screens  its  adver- 
tisers for  reliability,  which  will 
accept  letters  proposing 
almost  anything?  In  73,  In 
which  will  you  find  editorials 
which  most  likely  are  represen- 
tative of  a  majority  of  its 
readers,  if  not  of  amateurs  In 
general,  and  which  doesn't 
flip-ftop"  on  the  issues?  In  73. 

In   which   will   you    find   a 


multitude  of  column  inches 
devoted  to  relatively  useless 
columns,  and  claims  of  repre- 
sentation  of  the  amateur  while 
trumpeting  nonrepresentative 
views?  In  QST.  In  which  will  you 
find  the  most  apologies  for  a 
bumbling  FCC,  and  the  most 
"official  reportage"  with  the 
least  member  input?  In  QST. 
Which  magazine  can  usually  be 
relied  upon  to  review  a  ''new" 
product  long  after  it  has  been 
on  the  markets  or  to  fail  to  reply 
to  a  proposal  or  letter?  QST. 

I  don't  for  a  moment  be- 
grudge these  fellow  amateurs 
their  opinions,  and  I  applaud 
your  printing  of  them,  bul  I  just 
can't  figure  out  what's  so  great 
about  the  League,  It  has  its 
good  points,  just  as  73  has  its 
t}ad  points,  but  on  the  balance, 
ril  take  r^  anytime. 

R.  J,  Edmunds  WB2BJH 
Kinnelon  NJ 


QTH  I  NO 


IL 


For  many  years  t  have  been 
thinking   of   writing   to   the 

various  amateur  magazines  on 
the  following  subject,  but  kept 
putting  it  off.  However,  Tm 
finally  getting  around  to  it. 

I  have  been  on  the  air  about 
fifty  years.  During  that  time, 
when  I  called  a  CQ,  I  have 
always  given  my  location  (QTH) 
since  I  feH  many  amateurs 
wanted  to  know  where  the  call 
was  coming  from,  and  there  is 
always  the  chance  they  might 
have  phone-patch  traffic  for  my 
location. 

Back  in  the  old  days,  when 
someone  signed  W1,  W2,  W3, 
etc.,  one  always  had  a  general 
idea  of  his  location,  but  with 
the  complete  jumble  in  call 
assignments  by  the  FCC  re- 
cently, one  does  not  know  if  the 
call  is  from  their  neKt-door 
neighbor  or  from  Timbuktu, 

I  would  like  to  suggest  that  a 
movement  be  started  by  the 
various    magazines   to   have 

Contmued  on  page  116 


102 


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At  $1 39.95  this  MFJ484  GRANDMASTER 

memory  keyer  gives  you  more  features  per  dollar  than  any  other 

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OTWIHT  COtrmOL  TO   PENETRATE 
QFIM.  PULL  TO  COMBINE  MEMORIES 
A  AND  B  FOR  1 .  2,  Ofl  3  FIFTY 
CHARACTER  JVIESSAGEa 


MESSAGE  BUTTONS  SELECT  DESJflED  25  CHARACTER  MESSAGES. 


SPEED  CONTROL.  6  TO 
50  WPM.  PULL  TO 
RECORD. 


LEBl  (4)  SHOW  WHICH 
MEMORY  IS  IN  USE  AND 
WHEN  IT  ENDS. 


RESETS    MEMORY    IN 

USE  TO  BEGINNING. 


TONE    CONTROL, 
PULL  TO  TUNE. 


VOLUME  COtt- 
TROi,  POWER 
ON  OFF. 


OaAV  fVEFUkJ  COHTROL 
(0  TO  2  MINUTES).  PUtL 
F0«  AUTO  REPEAT. 


LED  INDICATES 
DELAY  REPEAT 
MODE. 


MEMORY  SELECT:  POSI 
TtONS  1.  2,  3  ARE  EACH 
SPLIT  INTO  MEMORY  SEC- 
TIONS A.  B.  C.  D  (UP  TO 
TWELVE  2S  CHARACTER 
MESSAGES)  SWITCH  COM 
BINES  A  AND  B.  POSOION 
HGrVES  YOy  100.  75.  50, 
OR  25  CHARACTERS  BY 
PRESSING  BUnONS  A.  B. 

&  on  0. 


NOW  YOU  CAN  CALL  CO,  SEND  YOUR  QTH. 
NAME,  ETC.,  ALL  AITTOMATICALLY. 

And  onJy  HFJ  oHers  you  the  MFJ-484 
Grand  master  memory  keyer  witti  this  much 
flexa&flity  at  this  price. 

Op  to  twdvi  25  character  messages  plys 
a  too.  75.  50,  or  25  ctiaracter  message 
(4D96  bits  total). 

A  iwlich  comMnti  25  character  messages 
for  up  to  three  50  character  messages. 

To  mconi,  pull  out  the  speed  control,  touch 
a  message  button  and  send.  To  playback, 
pusti  In  the  speed  control,  select  your  mes- 
sage and  touch  the  button.  That's  ail  there 
is  to  l\\ 

You  un  repeit  any  message  continuously 
and  eveit  leave  a  pause  between  repeats  (up 
to  2  minutes).  Example:  Call  CD,  Pause,  lis- 
teit.  tf  m  answer^  it  rapeats  CO  again.  To 
answer  simply  start  sefiding.  LEO  indicates 
Delay  Repeat  Mode. 


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playing  message  by  simply  sending.  Continue 
by  t04jchrng  another  button. 

Memory  resett  to  beginning  with  button,  or 
by  tapping  paddle  ^lA^hen  playjng.  Touching 
message  button  restarts  message. 

LEOs  slioiv  which  25  Character  memory  is 
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103 


The  Lunch  Counter 


eat  it  up 


Johnny  C  Chestnut  WA4FIN 
801  /v.  RamofiQ  A  venue 
Indiatamic  FL  S290J 


John  L.  Woicott  W4CCX 
490  E,  Riviera  Blvd. 
Indialanttc  FL  32903 


The  Lunch  Counter  proj- 
ect was  designed,  from 
start  to  finish,   as   a  ham 


• 


The  finished  Lunch  CountCL 


project  with  ham  specif  ica- 

tions.    Its    primary    goals 

were  that  it: 

1)be    technically    up    to 

date; 

2)  be  easy  to  build; 

3)  use   readily-obtainable 
parts;  and 

4)  involve  easy  case  fabri- 
cation. 

As  you  may  have  already 
surmised  from  the  name, 
the  entire  project  was  con- 
ceived and  designed  dur- 
ing a  series  of  eyeball 
QSOs  over  lunch,  A  few 
evenings  were  used  to 
build  the  prototype. 

All  of  the  particrpants 
work  in  electronics  in  some 
capacity,  but  none  of  the 
work  was  done  within  our 
respective  fields  of  exper- 
tise. As  an  example,  we 
elected  our  professional 
program  manager  to  be  the 
prototype  technician,  on 
the  theory  that  the  ex- 
perience would  be  good 
for  him.  While  only  two  of 
us  wrote  this  article, 
acknowledgement  is  given 
to  WA4QCE  for  mechani- 
cal   design,    WB4CDP   for 


104 


Interior  views  showing  construction  details  and  PC  board  mounting. 


layout  and  drafting,  and 
WB4UDI  and  WB4WWI  for 
parts  procurement. 

We  made  a  detailed 
evaluation  of  advertise- 
ments for  available  fre- 
quency counters.  It  soon 
became  obvious  that  the 
art  of  digital  frequency 
counters  has  progressed 
remarkably  in  the  past  few 
years  as  the  newer  ir>- 
tegrated  cfrcuits  have 
become  available.  As  the 
semiconductor  wizards 
pack  more  circuitry  into  an 
integrated  circuit,  the 
overall  size  goes  down,  the 
device  capability  goes  up, 
and,  best  of  all,  the  cost 
goes  down.  After  all  fre- 
quency counter  ads  and 
construction  articles  were 
reviewed  and  summarized, 
our  appetites  demanded 
the  best  features  from 
each,  and,  of  course,  no 
one  counter  met  all  our 
desires. 

Specifications 

At  this  point,  we  devel- 
oped a  target  specification 
which  would  satisfy  all  of 
us. 

1)  Cost  — cheap,  to  fit  a 
ham's  pocketbook. 

2)  Display  — six  digits,  big 
enough  to  read. 

3)  Frequency  range  — from 
audio  (touchtone^'^  pads) 
through  all  the  popular 
amateur  bands  (1 .8  MHz  to 
450  MHz), 

4)  Sensitivity  — sufficient 
for   most   solid-state    rigs. 


but  not  sensitive  enough  to 
produce  unnecessary  count* 
ing  on  noise  (10  nnV  to  25 
mV), 

5)  Accuracy— ±10  Hz  to 
±100  Hz  is  usually  fine  for 
most  amateur  purposes.  A 
good  quality  crystal  can  be 
adjusted  to  better  than  10 
parts  per  million  and  will 
easily  meet  these  criteria. 

6)  Stability  — stable  over 
the  temperature  range  en* 
countered  in  the  ham 
shack  We  did  not  expect 
to  use  it  outside  of  normal 
room  temperatures.  Long- 
term  stability  should  be 
good  enough  to  maintain 
accuracy  between  calibra- 
tion checks,  which  are  six 
months  to  one  year  for 
most  users, 

7)  Size  — small  enough  to 
fit  in  the  palm  of  the  hand, 
but  large  enough  to  have 
an  easy-to-use  front  panel. 

8)  Power— 12  V  dc  was  the 
choice  of  most  of  us  who 
participated  in  the  devel- 
opment.  Most    new   solid- 


state  rigs  operate  on  12  V 
dc,  and  a  110  V  ac  power 
supply  is  easy  to  build  for 
those  who  desire  it. 

Design 

The  design  that  evolved 
over  many  lunch  hours  is 
shown  in  the  block  dia- 
gram in  Fig.  1.  The  circuit 
was  divided  into  three 
functional  boards  — timing, 
counter,  and  display  The 
timing  board  contains  the 
oscillator,  dividers,  and 
timing  to  control  the 
counter  board.  The  count- 
er board  contains  the  six 
decade  counters,  latches, 
and  seven-segment  display 
drivers.  In  addition,  it  has 
the  input  amplifiers  and 
high-frequency  prescaler. 
The  display  board  holds 
the  six  LED  displays  Power 
requirements  are  met  by 
the  use  of  a  three-terminal 
regulator  to  obtain  5  V  dc 
from  an  8-16  V  dc  supply. 

Schematic  details  began 
with   the  selection   of   the 


74C925  as  the  workhorse  of 
the  counter.  This  is  a  new 
counter  chip  which  has  a 
full  four  stages  of  counter 
built  in  with  the  necessary 
latch,  seven-segment  de- 
coders, and  LED  drivers  It 
also  multiplexes  the  out- 
put drivers,  thus  greatly 
simplifying  the  wiring  to 
the  displays.  Comparing 
this  single  16-pin  in- 
tegrated circuit  to  an 
equivalent  set  of  conven- 
tional f  o  u  r-  d  i  g  i  t  T  T  L 
counters,  twelve  in* 
teg  rated  circuits,  twenty- 
eight  resistors,  and  twenty- 
eight  wires  to  the  display 
are  now  replaced  with  one 
integrated  circuit,  seven 
resistors,  four  transistors, 
and  eleven  wires  to  the 
display  board. 

Since  the  design  criteria 
called  for  a  six-digit 
counter,  two  more  stages 
must  be  added  By  using 
74LS90  counters  for  these 
stages,  the  frequency 
range  of  the  basic  counter 


CRYSTAL 

DEC^E 

T  1U.PBJ^r^ 

BOARD 

^ 

OSCILLAtOR 

I 

COUNT EHS 

— 

riaf  t 

— 

■ — 

F!E3ET 

r                1 

1   i- 

n  T^u 

. 

V*  •   b 

J 

U  -t^  '  V  ri 

OtRECT 
mPUT 

1 

h 

1 

f 

DISPLAY 
BOARp 

1 

1 

1 

INPUT 
SWITCH 

^ 

COUNTERS 

DECOOEH 
DRI^IRS 

DISPLAY 

1 
1 

PRESCALE 

II 

^pyT 

COUNTER    BOA^D 

fig.  1.  Lunch  Counter  block  diagram. 


105 


Top  view  showing  parts  layoul  of  timing  board 


will  cover  to  50  MHz.  The 
associated  latch  and 
decoder/LED  drivers  for 
these  two  stages  use  9368s. 
This  device  saves  a  couple 
of  integrated  circuits  by 
combining  the  latch,  de- 
coding, and  driving  func- 
tions, but  the  resistors  and 
wiring  to  the  LEDs  are 
cumbersome  when  com- 
pared to  the  multiplexed 
74C925.  It  must  be  noted 
that  the  digit  "9"  on  the 
9368  and  the  74C925  are 
decoded  differently- 

The  input  stages  to  the 
counter  are  either  the 
amplifier,  for  direct  input, 
or  the  divide-by-IO  pre- 
scaler.  A  front  panel  switch 
is  used  to  select  the  direct 
input  or  the  prescaler 
through  a  74LS00  gate  so 
that  the  high-frequency 
signal  path  is  always  from 
one   integrated   circuit   to 


the  next.  The  DIRECT/ 
PRE-SCALE  switch  only 
switches  a  dc  control 
voltage.  The  11C90  pre- 
scaler was  selected 
because  its  frequency 
range  exceeds  500  MHz.  It 
also  has  the  ECL-to-TTL 
conversion  built  in  and 
therefore  does  not  require 
additional  transistors  for 
level  conversion.  The 
prescaler  divides  the  high- 
frequency  input  by  10,  so 
its  output  is  within  the 
50-MHz  range  of  the  basic 
counter.  In  this  process, 
the  last  digit  is  dropped 
from  the  count,  and  the 
decimal  point  is  therefore 
moved  one  place  to  the 
right, 

The  function  of  the  tim- 
ing board  is  to  generate  the 
timebase  and  control  func- 
tions for  the  counter.  An 
accurate  gate  is  required 


which  will  allow  the  count- 
er to  count  its  input  for  a 
known  period.  The  counter 
uses  either  a  one-second 
gate  for  kilohertz  or  a  one- 
millisecond  gate  for 
megahertz.  The  timing 
board  also  provides  latch 
and  reset  pulses  to  update 
the  display.  The  latch  pulse 
updates  the  display  with 
the  previous  count,  and  the 
reset  pulse  clears  the 
counters  prior  to  starting  a 
new  count. 

Our  original  design  used 
a  1.3'MHz  crystal  because 
we  already  had  a  few  avail- 
able. The  first  stage  follow 
ing  the  oscillator  was  a 
74L193  programmed  to  di- 
vide by  13,  After  we  conri- 
pleted  the  printed  circuit 
board  artwork,  the  plan  to 
make  the  Lunch  Counter 
into  a  club  project  devel- 
oped. At  this  point,  we 
modified  the  artwork  to 
permit  the  use  of  a  more 
readily  available  1.0-MHz 
crystal  as  an  option 

The  power  supply  is 
simply  a  S-terminal  regu- 
lator bolted  to  the  rear  of 
the  chassis  with  the  bypass 
capacitors  soldered  direct- 
ly to  the  terminals  and  a 
solder  lug  under  the 
mounting  screw.  We  used  a 
small  heat  sink  to  reduce 
the  regulator  temperature, 
but  several  have  been  built 
using  just  the  chassis  for  a 
heat  sink  with  good  results, 
A  parts  list  for  the  Lunch 


Counter  is  included  with 
this  article.  The  parts  are 
easily  available  through 
advertisers  listed  in  any  of 
the  ham  radio  magazines, 
such  as  73.  The  nC90  and 
74C925  are  the  most  expen- 
sive parts  and  the  9368s 
come  in  a  close  third. 

Construction 

Construction    is    very 
straightforward     Printed 
circuit    board    assembly 
should  be  started  with  the 
jumpers  on  the  component 
side,   followed   by  the   in- 
tegrated   circuit    sockets, 
and    then    the    remaining 
components.    The    display 
board    is    mated    to    the 
counter  board  with  cutoff 
resistor    leads    or    bits    of 
hookup  wire  bent  at  a  right 
angle.  Both  boards  may  be 
mounted    In    the    cabinet 
with  long  bolts  and  stand- 
offs.   Wiring    between 
boards,    the   switches,    in- 
puts,   and    power    supply 
completes  the  wiring.  The 
boards  are  then  mounted 
in  the  cabinet  and  the  LEDs 
lined  up  with  the  window. 
The  case  is  widely  avail- 
able through  Radio  Shack 
stores.    A    silk-screened 
front  panel  gives  the  unit  a 
professional    appearance 
and    makes    the   construc- 
tion easy.  Cutting  the  rec- 
tangular hole  in  the  front 
panel  may  be  the  most  dif- 
ficult    part    for    some 
builders,    A   nibbling   tool 


Timing  board  —  component  side. 


Timing  board  —  foil  side. 


106 


vcc 


tOOHj 


lOHt 


vcc 


LATCH 
LATCM  GAtE 


INPUT  @- ^f 


TV 


INPUT     ®— f 


IC 

VCC  PtW 

OHD  P«r4 

ui,  i*  %  tS,  13 

14 

r 

III*T^  14,   16 

a 

lO 

uto 

4.  6,  7,  10 

ti 

«|l» 

*** 

12,13,14 

UlS,  IT.  IB 

l« 

B 

Fig,  2,  Schematic. 


does  a  good  job  on  this 
hole.  Some  of  us  used  a 
Dremel  tool  to  cut  out  the 
hole.  We  then  glued  a  red 
piece  of  Plexiglas"^^  to  the 
back  side  of  the  hole. 

Suggested  Wiring  Se- 
quence 

1.  Jumpers  under  sockets 
"10  total, 

2,  Sockets  — remove  un- 
used pins  from  display 
sockets. 


3.  Ail  other  onboard 
jumpers. 

4.  All  other  components. 

5.  Mount  display  board  to 
counter  board. 

6.  Wiring  between  boards. 

7.  Mount  front  panel  on 
cabinet;  drill  holes  and  cut 
window. 

8.  Mount  PC  boards  in 
cabinet 

9.  Complete  mechanical 
assembly. 
10.  Complete  wiring. 


Calibration 

The  only  alignment  re- 
quired is  to  put  the  oscil- 
lator exactly  on  frequency* 
We  made  provisions  for  a 
fixed  padder  (C2)  in  paral- 
lel with  the  trimmer  (CI)  to 
be  used  if  necessary.  If  the 
oscillator  adjusts  to  the  ex- 
act frequency  with  the 
trimmer  alone,  C2  is  not 
needed.  If  the  oscillator 
frequency  is  too  high  with 
the    trimmer,    CI,    fully 


meshed,  C2  should  be  add- 
ed to  tower  the  frequency. 
Note  that  a  low  oscillator 
frequency  will  result  in  a 
high  count  when  using  the 
frequency  counter.  The 
most  accurate  alignment 
method  is  to  use  the 
counter  to  count  a  known 
laboratory  frequency  stan- 
dard. A  frequency  above 
10  MHz  is  preferred  to  ob- 
tain  the  best  accuracy. 
Alternate    calibration 


107 


Counter  board  —  foi}  side. 


sources  would  be  a  100- 
kHz  crystal  calibrator  or  an 
oscillator  zero  beat  to 
WWV.  Also,  there  have 
been  several  magazine  ar- 
ticles on  using  the  TV  color 
burst  frequency  as  an  ac- 
curate standard, 

Troybleshooting 

The  counter  should  read 
all  zeros  (the  last  digit  may 
read  1)  with  no  input  signal. 
If  it  does  not,  the  following 
sequence  of  troubleshoot- 
ing is  suggested: 

1 .  Double  check  al  I 
jumpers  and  wiring. 

2.  Check  for  5  V  dc  on  each 
IC  as  per  pin  connection 
table  on  the  schematic 

3.  If  individual  segments  of 
one  or  more  LEDs  do  not 
light,  check  the  display  by 


interchanging  LEDs,  and 
check  wiring  and  solder 
joints  on  the  display  and 
counter  boards. 
4.  If  one  LED  does  not 
light*  check  the  corre- 
sponding driver  IC  and/or 
transistor. 

5  If  the  display  lights  but 
does  not  reset,  check  the 
following: 

a.  Check  the  oscillator 
by  connecting  a  scope 
to  pin  6  of  U1-  You 
should  see  a  1-MHz 
square  wave. 

b.  Check  the  GATE 
pulse  by  connecting  a 
scope  to  pin  9  of  U10 
You  should  see  a  1-ms 
square  pulse  (MHz-kHz 
switch  in  MHz}. 

c.  Check  the  LATCH 
pulse   by   connecting  a 


m 


•^ 


1 


Counter  and  display  boards  showing  parts  layout 


Display  and  counter  boards  showing  LEDs  and  mounting 
technique. 


scope  to  pin  11  of  U8. 
You  should  see  a  0.1 -ms 
square  pulse  every  2  ms. 

d.  Check  the  RESET 
pulse  by  connecting  a 
scope  to  pin  3  of  U8.  It 
should  look  exactly  like 
the  LATCH  pulse. 

e.  Check  for  correct 
GATE.  LATCH,  LATCH, 
and  RESET  pulses  on 
LC2. 

6.  If  the  display  lights  but 
does  not  count,  check  the 
following: 

a.  Connect  the  100-kHz 
test  point  to  the  DIRECT 
input  Put  the  DIRECT/ 
PRE-SCALE  switch  in 
DIRECT  and  check  for  a 
100-kHz  square  wave  at 
pin  4  and  pin  11  of  U13. 
The  display  should  read 
000100  with  the  MHz- 
kHz  switch  in  MHz. 

b.  Move  the  input  signal 
to  the  PRE-SCALE  input, 
put  the  DIRECT/PRE- 
SCALE  switch  In  PRE- 
SCALE,  and  check  for  a 
10-kHz  square  wave  at 
pin  1  and  pin  11  of  U13. 

c.  Check  for  a  10-kHz 
square  wave  at  pin  1 4  of 
U14  and  a  1-kHz  square 
wave  at  pin  4  of  U14. 

d.  Check  for  a  1-kHz 
square  wave  at  pin  14  of 
U16  and  a  100-Hz 
square  wave  at  pin  4  of 
U16. 

Use 

The    direct    input    is 
generally  used  for  frequen- 


cies under  50  MHz.  The 
timebase  switch  may  be  set 
to  either  the  MHz  or  kHz 
position.  The  decimal 
point  on  the  readout  is 
located  after  the  third  digit 
to  correspond  to  MHz  or 
kHz.  In  the  kHz  position, 
the  least  significant  digit  is 
0.001  kHz  or  1  Hz,  When 
reading  frequencies  above 
1  MHz,  you  can  read  to  the 
nearest  kHz  in  the  MHz 
position,  then  switch  to  the 
kHz  position  and  read  the 
last  three  digits  to  the 
nearest  Hertz. 

Between  50  MHz  and 
500  MHz,  you  must  use  the 
prescaled  input.  The  pre- 
scaler  divides  the  input  fre- 
quency by  10  and  does  not 
display  the  least  significant 
digit.  Therefore,  the 
decimal  point  is  moved 
one  place  to  the  right  to 
properly  index  the  display. 
By  using  the  MHz/kHz 
switch,  a  prescaled  fre- 
quency can  be  displayed  to 
the  nearest  10  Hertz 

Accuracy,  temperature 
stability,  and  long-term 
drift  of  any  counter  are  on- 
ly as  good  as  the  crystal 
timebase.  Most  reasonably- 
accurate  1-MHz  crystals 
can  be  trimmed  to  exactly 
1  MHz  with  a  little  care,  so 
the  initial  accuracy  will  de- 
pend on  the  facilities  you 
have  for  calibration  Tem- 
perature stability  and  long- 
term  drift  depend  on  the 
crystal    quality    and    the 


108 


oscillator  circuit.  In  the 
counters  we  built,  these 
two  effects  were  less  than 

0.0005%  over  normal 
room  temperature.  After 
all,  we  did  not  intend  to  use 
the  counter  at  tempera- 
tures where  we  do  not 
function  welf  For  greater 
stability,  a  high-quality 
crystal  and  oven  can  be 
used. 

The  sensitivity  of  the 
Lunch  Counter  was  mea- 
sured as  10  mV  up  to  50 
Mhz  in  the  direct  mode 
and  50  mV  up  to  500  MHz 
in  the  prescale  mode  This 
is  sufficient  to  measure 
most  transmitters  using  a 
short  antenna  on  the  input, 
without  a  direct  connec- 
tion. The  most  important 
caution  is  not  to  overcou- 
ple  to  the  counter,  Ex- 
cessive input  causes  multi- 
ple counts  and  a  reading 
much  higher  than  ex- 
pected. Of  course,  if  you 
couple  too  much  energy  in- 
to the  input,  you  can 
damage  the  input  circuitry. 
Diodes  are  provided  across 
the   inputs   to   reduce  this 

possibility, 

As  the  word  of  our  proj- 
ect spread  through  the 
local  club,  it  was  soon  ap- 
parent that  a  counter  was 
of  universal  interest.  As  a 
result,  boards  were  made 
available,  and  more  than 
50  were  constructed  by 
members  of  the  Platinum 
Coast  Amateur  Radio 
Society. 

We  had  a  lot  of  fun 
designing  and  building  the 
Lunch  Counter.  We  have 
met  our  goals  of  a  simple- 
tO'build  counter  with  ex- 
cellent specifications,  and 
it  has  generated  a  lot  of  in- 
terest as  a  local  club  proj- 
ect. By  using  a  good  case 
and  a  good-looking  front 
panel,  any  ham  should 
be  able  to  make  a 
professional-looking  piece 
of  test  equipment  like  the 
ones  which  are  now  in- 
dispensable in  our  shacks. 

The  three  printed  circuit 
boards,  a  0.020-inch-thick 
aluminum  silk-screened 
front  panel  with  adhesive 


back,  and  documentation 
are  available  from  Johnny 


Chestnut,  801    N.   Ramona 
Avenue,    Indialantic    FL 


32903.    for    $12.50    post- 
paid. ■ 


Parts  List 

Capacitors 

Size 

CI 

10-60  pF  trimmer 

C17 

100  pF 

09 

0.001  uF  ceramic  disc 

03,  04,  C11,  012 

.015. 

020 

,  C22,  C24 

0.01  uF  ceramic  disc 

06,  07.  C8,  CIO.  1 

014,  C16, 

019.021,023 

0.1  uF  ceramic  disc 

026 

0  22  uF.  50  V 

027 

1  uF,  10  V  tantalum 

018 

4.7  uF.  10  V  tantalum 

05,  013.  025 

10  uF.  10  V  tantalum 

02 

'Selected  at  test 

Diodes 

D1-D4 

1N414S 

Displays 

11  16 

DL-704 

Transistors 

Q1 

MPF-102 

Q3-Q6 

2N2222 

Q2 

2N2369 

Resistors  (all  V^-Watt) 

R15'R21 

120  Ohms 

R2 

150  Ohms 

R8 

220  Ohms 

R22R35 

390  Ohms 

R9,  RIO,  R14 

470  Ohms 

R1,R3 

6S0  Ohms 

R7,  R12,  RT3 

4.7k  Ohms 

R11 

15k  Ohms 

R4 

47k  Ohms 

R5 

100k  Ohms 

R6 

1.8  megohms 

Switches 

S3 

SPST 

S2 

SPOT 

SI 

DPDT 

ICs 

U11 

11090 

U1,U8 

7400 

U12.  U13 

74LS00 

ug 

7420 

U10 

7473 

U2'U7,  U16 

7490 

U14 

74LS90 

U18 

740925 

uig 

7805 

U15,  U17 

9366 

CrystaT 

Y1 

1  MHz.  0.001%  toleran 
30  pF  parallel  resonan 

PC  boards 

L01 

Clock  and  timing 

LC2 

Counter 

LC3 

Display 

Miscellaneous 

Archer  #270253  (Radio 

Shack) 

Cabinet 

31/4"  X  Vm 


II 


Quantity 
1 
1 
1 
8 
9 
1 
1 
1 
3 
1 

4 

6 

t 
4 
1 

7 
1 
1 

14 
3 
2 
3 
1 
1 
1 
1 

1 
1 
1 

1 
2 
2 
1 
1 
7 
1 
1 
1 
2 


1 
1 

1 


F1 


RG-174 

BNC  panel  connector 

Red  plastic  window 

Test  lead  (BNC-  alligator  clips) 

Power  cord  and  connector 

Strain  relief 

14-pin  DIP  sockets 

16-pin  DIP  sockets 

#4  hardware 

Fuse  and  holder  (1  Amp) 

•02  (silver  mica)  may  be  used  if  CI  is  not  suffi- 

cieni  to  calibrate  the  crystal;  otherwise  it  should 

be  omitted  (approximate  value  is  60  pF). 


1 

18" 
2 
1 
1 
1 
1 

20 
4 

assorted 
1 


109 


— The  Full  Spectrum  of  VHF 

SCR  1000  -  Standard  oi  Comparison 
In  Repeaters  -  Now  Hvailable  with  Hutopatch 

-  and  Many  Other  Options  I 


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The  SCR1000/SCAP  Combination 


A  A/ew 


Dimension  in  Autopatch  Repeater  Performance 

2M  &  22011/IHi 

Now  Spec  Comm  has  taken  the  hassle  out  of  putting  an 
autopatch  repeater  on  the  air!  The  SCR1000/SCAP  is  a 
fully  self-contained  .iO  watt  repeater  with  built-in 
autopatch  and  land  line  control.  You  simply  plug  in 
the  phone  line,  hook  up  the  duplexer,  and  you're  on 
the  air!  The  usual  months  of  problems  are  eliminated! 
The  SCRIOno/SCAP  has  been  meticulously  eni^ineered 
to  provide  the  smoothest  performing  patch  together 
with  a  positive  land  line  control  of  the  repeater.  Just 
look  at  all  these  features: 


yeatu^tcd: 


•  Normal  patch,  or  secure  "reverse    patch 

•  3  digit  antt4alsing  access  —  single  digit  dis< 
connect 

m  3  digit  on-off  control  of  repeater  transmitter 

•  4  sec.  time  limit  on  access 


Built-in  adjustable  time-oyt  function  —  patch 
shuts  down  in  30-90  sec.  If  no  carrier  is  received 
Wide  range  AGO  on  audio  input  and  output 
User  can  mute  phone  iine  audio  simply  by  key- 
ing his  mic  button  —  prevents  embarrassing 
language  from  being  repeated 
Patch  access  and  repeater  control  —  either 
over  the  aW  or  over  the  land  line 


The  SCR  1000/SCAP  is  a  complete  Autopatch  Repeater  —  fully  assembled,  set-up  and  checked- 
out  in  our  lab.  As  with  all  Spec  Comm  products,  all  workmanship  and  components  are  of  the  very 

highest  qual  ity.  The  price?  A  very  reasonable  $1 700.00,  ($21 95  w/  WP641  Dupiexer).  Get  your  order 
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1 80  Day  Warranty 


SPECTRUM 


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110 


/FM  Repeater  Equipment  — 

The  SCR  1000  **DrBam  Machine**  Sysiem  is  Continually 

Being  Improved  -and  Expanded! 


Recent  Improvements 

D  New,  More  stable,  Mow*nofSe'  transmitter  exciter 

D  Improved    Rcvr.    Front-End    &    I.F.   Selectivity.  {FL-6 
Preselector  &  8  Pole  Crystal  FHr,  now  Standafd!) 

n  New,  great ty  expanded  memory  CW  IDer.  (Up  to  4  dif- 
ferent  IDs  as  an  option!) 

D  Improved  Power  Supply  long-term  rellabifity. 


SCR1000  System  Options 

D  Full  Autopatch,  *Reverse-PatchVRptr.  landline  control. 

D  TouctitoneTM  Control  of  various  rptr,  functions,  (eg, 
Rptr.  or  '*PL"  ON/OFF,  Hl/LO  Pwr.,  etc) 

D  "PL";  Multi-Freq.;  Hl/LO  Pwr.;  10  Pole  Xtal  Fitr,;  Up  to  4 
IDs;  Timer  Reset  Tone;  TX  Xtal  Oven. 

a  60^70  Wt.  Transmitter 

D  Duplexers,  Cable,  Antennas^  Cabinets,  etc.  Please  in- 
quire. 


D  We  feel  the  SCR1000  \s  simply  the  finest  repealer  available.  It  is  often  compared  to  other  (lesser  featured]  units  selling  for  3X  the  price!  Thrs  30 
Wt  unit  has  a  very  sensitive  &  selective  receiver,  and  its  superb  repeat  audio  quality  is  famous  for  "sourtdtng  like  direct"!  Included  is  a  buitt-m  AC 
Supply,  CW  IDer,  full  metertng  &  lighted  status  indicator/control  push-buttons,  crystals,  local  mic^  etc.  Also  provided  are  jacks  for  Emergency 
Power,  Remote  Control,  Autopalch,  Auv.  AF  In.  etc 

Q  The  Spec  Comm  Kepeater  System  a  sound  long-term  investment  —  for  those  who  demand  the  finestl  An  excellent  value  at  $1150.00. 
[$106S.OO  w/o  Preselector,]  Available  only  by  direct  factory  order. 


SPEC  COMM  REPEATER  BOARDS,  SUB-ASSEMBLIES  &  ACCESSORIES 


SCR  100 
BOARD 


All  eqmpment  assembled  &  testad.   For  2IVI  Se  220  MHz, 


SCTtIO  BOARD 


SCR100  Fl«Ciai¥«r  Board 

•  Wide   dynamic   rarige!    Reduces  overload, 
'ds««na«'.  and  IM. 

•  S^ns  03  uV/2a  dS  Qt  typ. 

•  Sel    -6dB  0    2   6S  KHz.  -SOdB  •   ±30KHi. 
(*110dB  */opt-  6  Pole  Fllr.)  10  Pole  Fltr  Avail 

•  S  Meter'  Output 

Eic  audio  quality!  Fasi  squeJch!  S125^00  w/xtal. 
8  Pole  FItr.  (Highly  recom mended  J  $15.00 
SCR  100  Receiver  Assembly 
m  3GR100  maunted  in  shielded  housinQ 

•  Same  as  used  on  SCR  1  DOG 

•  Completely  asmbld.  w/F.T.  cape.  S0239  conn., 
AF  QAm  POT,  etc.  1195,00 


SCAP  Au1o|i«lch  Boird 

•  Provides  ail  basic  aiutopatcn  fuTvctions 

•  S««  reaiur«s  on  opposite  page.  S23Su00 

RPCM  Boini 

•  U6«d  w/SCAP  board  lo  provide  "Reverse  Patch^ 
arid  Isnd^line  control  ot  rplr. 

«  Inciucfes  land  lini  "answofing"  circuitry.  S79.99 

WP041  Duplexer 

•  Superior  Band  Pa  as/ Band  Reject  deslgri 

•  Provides  great   rejection  ol  "out-of-  barid" 
signals 

•  Bttremely  easy  !o  adfust 

•  -93dB  typ.  isolation    £495.00  \fuUi  ckd^  out 
«;SCR10D0) 


FL-Q  Hcvt.  Frofit'End  Preselector 
6  section  f titer  witt>  FET  preamp. 
Provides  trefivendous  refect  ion  of  "out^of-band" 
3ign.als  wtouX  the  usual  lossi 
EKtremely  hetpfut  at  s^es  with  many  nearby 
VHP  trans  milters 
Ga^n:  apx.  10  dB 
Seleclivity:  -20  dB  @  ±Z0  MHsi;  -60  dB  @ 

±  e  MHz  ayp-} 

$85.00 


TRA-1  TIfrwf  Reeet  Annunciator  Soird 

•  Puts  out  a  torw  '"beep  '  on  rptr.  xmir.  apx,  1  sec. 
aflef  fcvd.  signal  drops  —  thus  alloinrlng  timo 
lof  breakers 

•  Resets  rplr.  Ume-out  tlmv  when  tone  is  emitted 
9  Adjustable  time  de^ay  and  tone  duration 

•  Used  with  CTC100  and  I D1 00/250 

•  $20.95  (Add  S/fflOO  for  Inst,  &  ck.  out  in 
SGR1000) 

CTC100  COR/Tlmar/Con(roi  Board 

•  Complete  CQR  circuitry 

•  Carreer  Hafig'  &  TO  Timers 
«  Remote  itmtr.  OhWOFF  control 
m  ProvistOf)  for  panel  control  switches  $.  Lamps 

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•  CMOS  logic;  PROM  memory— 250  blt«/€hafi. 

•  Up  to  4  Cihm^til  ID  channels^ 

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•  Local  MtC:  $18.95 


SCT  110  XmtrfExcfrar  Board 
for  10  Wts.  Output 

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True  FM  for  exc.  audio  quality 

New  Design  —  specifically  Tor  continuous  rptr, 

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With  .0005%  Jttal.  1 135.00 

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m  S«me  as  us«d  on  SCRiQOO 

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•  7  Of  >0  Wt.  unit  S199.95.  Add  $©800  for  30  Wl. 
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TTC100  TOUCH  TONE™ 
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TTC100  Touchlone^M  Control  Board 

»3  digit  ON.  3  digll  OFF  control  of  9  Single 
repeater  function.  Or.  2  functions  ON  (2  digits 
eacti)  «ith  1  digit  ^each)  OFF, 
^Can  be  used  to  pull  In  a  relay,  trlggef  logic,  etc. 
Typically  used  for  F^ir.  ON/OFF,  Hl/LO  Pwr^ 
P.L  ON/OFF.  etc. 
I  Stable,  am  I -falsing  design. 
$85.00 ($110,00  Insl,  &  citd-  out  m  SCRIOOOO) 


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tit 


W2NSD/1 

NEVER  SAY  DIE 

editorial  by  Wayne  Green 


ffow  page  4 

Well,  ARM  A  was  in  serious 
need  of  some  activity  which 
would  be  of  benefit  to  the  entire 
ham  industry  as  a  way  of  attract- 
ing members.  They  were  forined 
to  fight  the  linear  amplifier 
nonsense,  but  this  was  of  in- 
terest only  to  a  few  manufac- 
turers, so  ARMA  meetings  were 
small ;. .  very  smalL 

Both  as  a  rallying  effort  for 
ARMA  and  as  a  response  to  the 
threat  of  the  44  African  nation 
black  bloc  which  couid  well 
eliminate  ait  amateur  alloca- 
tions at  WARC,  I  convinced 
ARMA  to  try  to  support  a  mis- 
sion to  Africa,  ARMA  voted 
overwhelmingly  to  support  the 
plan. 

ARMA  decided  to  put  the  job 
of  writing  the  letter  asking  for 
support  from  both  the  industry 
and  individual  amateurs  in  the 
hands  of  two  chaps  from  Ham 
Radio  magazine.  1  expressed 


concern  over  this,  for  the 
ARRUHf?  connection  is  hardly 
any  secret.  ARMA  members 
seemed  to  feel  that  this  was 
too  important  a  matter  to  suffer 
any  political  shenanigans. 

Unfortunalefy,  it  turned  out 
that  )  was  right  again.  Not  only 
did  the  letter  ne^^er  gel  written 
(that  was  four  months  ago),  but 
the  promised  piece  in  HR 
Reports  asking  for  support  also 
did  not  appear.  HR  Reports  did 
print  a  short  put-down  of  the 
idea  and  then  later  resorted  to 
outright  lies  to  try  to  back  this 
up,  saying  that  the  ARMA  direc- 
tors had  voted  against  the 
African  plan. 

Should  we  only  lose  a  smatt 
part  of  our  allocations,  I  hope 
that  indignation  will  run  high 
enough  so  amateurs  will  get 
busy  and  get  some  better  ARRL 
directors  elected  and  have 
them  get  an  executive  search 
firm  to  find  someone  with 
business   background   and   a 


history  of  honesty  to  manage 

the  League.  Having  this  $5 
million  empire  in  the  hands  of 
Incompetents  is  a  crime  which 
could  very  possibly  lose  us  the 
whole  ball  of  wax. 

If  we  lose  everything,  then 
the  problem  will  have  been 
neatly  solved.  No  amateur 
radio,  no  League,  and  some 
people  will  be  on  welfare  at  the 
general  public  expense  instead 
of  ours. 

While  I  am  writing  about  the 
League,  I  wonder  il  you  knew 
that  their  Hartford  convention 
last  year  ended  up  with  a  profit 
which  went  into  the  ARRL  kitty. 
Some  $3,000,  I  understand. 
Would  this  have  been  better  in- 
vested in  lower  admission 
charges  which  might  have  en- 
couraged younger  hams  to 
come  to  the  show? 

There  has  been  some 
criticism  ol  the  board  action  to 
authorize  the  short-term  bor- 
rowing of  about  a  quarter 
million  dollars  to  help  pay  the 
day4o^day  League  expenses. 
Despite  record  income,  the 
ARRL  has  been  racking  up 
record  losses.  Instead  of  figur- 
ing out  how  to  make  their 
books  better  so  they  will  sell 
more,  they  are  responding  by 
laying  off  people.  Indeed,  many 
of  their  best  people  have 
recently  jumped  ship  ,,, 
Dunkeriy,  the  Whites,  McCoy, 


etc.  Laying  off  people  will  only 
empty  some  of  those  new  and 
expensive  offices  they  just 
built  and  are  now  trying  to  pay 
for. 

Amateur  radio  is  growing  at  a 
high  rate  and  we  see  this  in  73 
In  an  increase  in  both  subscrip- 
tions and  advertising.  The  re- 
cent issues  have  been  the  larg- 
est In  our  history  and  we  have 
been  doing  everything  we  can 
to  get  more  people  to  work 
here,  while  ARRL  has  been  fir- 
ing their  people. 

We  need  people  to  work  in 
our  book  department  to  prepare 
books  for  publication.  Every 
lime  we  gel  someone  trained 
for  this,  the  73  staff  grabs  them 
to  work  on  the  magazine,  ieav- 
ing  us  shorthanded  for  book 
preparation  again.  We  need 
people  interested  tn  marketing, 
advertising,  drafting^  a  good 
technician  to  help  test  ham 
gear  layout  and  pasteup  peo- 
ple, plus  a  lot  more  help  with 
our  microcomputer  magazine 
and  software  plans.  We  are 
nearing  a  staff  of  100  now  and 
are  projecting  200  by  late  next 
year  and  300  in  1980, 

If  amateur  radio  should  get 
killed,  73  would  have  to  become 
an  experimenter  magazine  and 
would  undoubtedly  shrink  a  lot. 
We  don't  know  what  the  possi- 
bilities are  for  180  kHz  low- 
power  communications  ...  or 


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New  Castle  DE 

Pflul  WA3QFX,  Rob  WA3QLS— Servittg 
amateuri^  In  iOUlK^rn  New  Jersey.  Delaware, 
and  Maryland  wiihthtlarftcsl  stock  of  amattur 
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iroaiet,  I2m  Ibvadm}.  B«bc  ID  Uim,  Bob 


Tell  ihem  you  saw 
iheir  name  in  73 


Preston  ll> 

Ron  WB7BYZ.  has  ihe  Utfgcit  Slock  of 
Anmteur  Goir  in  the  luiermutintiun  Wesi  aiid 
Ehe  ilcsl  Prtcfes.  CaU  me  for  all  your  ham  needs. 
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as  many  ax  2S  warttxfor  as  Uttk  m  $f^0  yearfy 
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lifh,  \fmt  fv  7}  Vtagazt/ff^  f^^bmi$it  %  H 
ff34Si,  4  IT  Vr  Aline  Cmttm 


112 


what  might  be  developed  In 
underground  communications. 
Would  amateurs  shift  to  11 
meters  and  the  HF  band?  The 
CB  repeater  band  would  get  a 
good  workout,  for  sure. 

These  are  bad  thoughts,  so 
in  general  I  agree  with  the 
ARRL  leaders  and  their  ap- 
proach ...  "they  can'i  kiil 
amateur  radio!"  Keep  thinking 
those  happy  thoughts. 

With  or  without  an  amateur 
radio  magazine,  our  microcom- 
puter magazine  wHI  be  continu- 
ing to  grow.  Plus,  we  have  two 
more  magazines  in  the  works 
and  the  instant  Software  proj- 
ect, so  we  will  be  growing  in 
size  even  H  amateur  radio  does 
disappear.  IHaving  been  an  avid 
ham  for  some  40  years,  I'll  sure 
hate  to  lose  It.  It's  been  a  big 
pari  of  my  life. 

During  the  las!  40  years,  Tve 
talked  with  amateurs  in  well 
over  30€  countries  and  visited 
them  in  almost  100.  I've  had  fun 
with  RTTY,  NFM,  SSTV,  SSB. 
moonbounce,  OSCAR*  micro- 
waves,  repeaters,  and  a  whole 
lot  of  rag  chewing.  I'll  never 
forget  the  pileups  I  ran  into 
from  many  rare  spots  or  the 
thrill  of  pioneering  new  modes, 

(f  things  should  go  against 
uSt  how  soon  would  the  axe 
fall?  As  near  as  I  can  figure, 
even  if  we  lost  everything,  ft 
would  take  several  years  before 
we  would  actually  be  put  off  the 
air.  We  would  still  get  a  lot  of 
action  from  our  new  rigs  . .  • 
and  some  of  the  newest  stuff  is 
fantastic.  We  would  not  be  out 
of  business  until  our  govern- 
ment ratified  the  ITU  agree- 
ment. With  no  lobby  in  Wash- 
ington to  express  our  concern 
over  this  matter.  Congress 
might  not  waste  too  much  lime, 
particularly  if  the  EIA  were  in 
there  pushing  against  us.  Yet 
even    when    Congress   acts 


quickly,  it  can  take  years. 

Can  the  U.S.  simply  drop  out 
of  the  ITU?  If  amateurs  lose  fre- 
quencies, you  can  be  sure  that 
commercial  and  military  in- 
terests will  also  lose  them 
whoJesaie,  so  we  won*t  be  the 
only  group  burnt.  How  practical 
is  (t  to  consider  trying  to  go  it 
alone  and  not  have  to  toady  to 
the  African  countries?  Well, 
we've  been  having  the  same 
problem  with  the  U.N.  and  we 
haven't  dropped  out  of  that  yet, 
no  matter  how  miserable  they 
make  it.  The  ITU  is  a  branch  of 
the  U.N.,  by  the  way.  It  seems 
unlikely  that  we  would  pull  out, 
no  matter  how  revolting  the 
consequences. 

So  far  Tve  had  nothing  but 
comments  of  agreement  on  my 
evaluation  of  the  situation,  I 
know  the  ARRL  disagrees,  but 
no  one  in  the  ARRL  has  come 
up  with  any  good  reasons  for 
disagreeing.  Others  claim  that  I 
have  been  guilty  of  understat- 
ing the  seriousness  of  the 
situation.  If  anyone  has  any 
words  of  cheer,  the  pages  of  73 


are  wide  open.  Let's  know  It  if 
you  have  any  data  which 
changes  the  picture.  We  really 
need  a  change. 

WHAT  ABOUT  NEXT  YEAR? 

While  December  is  best 
known  for  offering  us  Christ- 
mas, a  holiday  to  which  I  am 
not  partial,  it  aiso  inciudes,  at 
no  extra  cost.  Hew  Year's  Eve* 
Whee, 

Since  a  birthday  gets  only  a 
small  celebration,  It  is  not  quite 
as  traumatic  as  the  New  Year, 
where  it  is  made  ciear  that 
everything  and  everybody  is 
now  a  year  older.  It  is  a  time  for 
introspection.  Let's  mull  over 
amateur  radio,  putting  the  last 
year  into  perspective  and  see- 
ing what  we  have  going  for  us 
for  1979. 

My  recent  experiences  with 
the  reiativeiy  simple  10.5-GH2 
rigs  is  indicative  of  some  of  the 
fun  that  lies  in  store  for  the 
adventurous.  Bandwidth  is  not 
a  problem  at  these  frequencies^ 
so  we  can  use  such  microwave 
links    for   teievision,    data 


transfer,  or  whatever  we  want 
to  cook  up.  Of  course,  the  sad 
fact  that  we  have  iosl  this  in- 
credible band  for  satellite  use 
through  blundering  at  Geneva 
is  something  we  will  have  to 
live  with  as  long  as  we  have 
amateur  radio,  it  didn't  seem 
quite  as  important  when  there 
was  nothing  much  availabte  in 
equipment  to  use  on  these 
bands,  and  therefore  they  were 
of  Interest  only  to  a  tiny  group 
of  hams  with  machine  shops 
and  incredible  patience.  Now, 
with  relatively  simple  and  inex- 
pensive equipment  coming 
available,  we  will  begin  to  fee^ 
the  pinch  and  begin  to  really 
understand  what  has  been  lost 
. . .  forever. 

The  sunspots  have  been 
coming  back  In  spurts,  Just  as 
our  propagation  editor  said 
they  would.  Incidentally, 
Nelson  was  the  only  profes- 
sional in  this  field  to  make  such 
a  prediction,  so  I'm  sure  he's 
sitting  back  with  a  smug  look 

Continued  on  page  246 


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113 


Rob&rt  VillasmgQ  K5GN2 

Z09  Irvington 

San  Antonio  TX  7B2Q9 


Confessions  of  a  Stripper 


confirmed  junkor  tells  all 


Which  are  you?  The 
**iunkee'*  Is  a  collec- 
tor of  odds  and  ends,  an 
impulse  buyer,  a  pack  rat  — 
don't  throw  it  away,  you 
might  be  able  to  use  it  some- 
time. The  "junkor"  strips 
everything  now  and  gets  rid 
of  the  excess  -  if  he  can't  use 
it,  he  throws  it  away  -  he  can 
always  get  another  one,  the 
junk  yard  or  surplus  house  is 
full  of  them. 

If  you  are  an  experiment' 
er,  you  probably  fit  into  one 
of  the  categories*  Articles 
about  stripping  surplus  equip- 
ment  are  commonplace 
among  the  old  issues  of  many 
magazines,  articles  on  how  to 
strip  a  TV  set  and  get  usable 
parts  for  the  do-it-yourself 
projects,  or  stripping  par- 
ticutar  Gl  units  ^sily  ac- 
quired to  obtain  the  neces- 
sary parts  for  a  specific 
project.  But  every  article 
assumes  that  you  know  what 
to  do  with  the  residue  of  the 
stripped  unit  after  the  project 
is  complete^  or  that  parts 
desired     are     removed.     It's 


assumed  that  the  '*junk"  will 
be  thrown  away.  Don't  do  li. 
You  can  save  yourself  a  little 
cash  and  also  do  your  thing 
for  ecology. 

Stripping  or  junking  is,  in 
realityp  an  art  form.  I  have 
seen  salvage  metal  buyers 
who  can  handle  a  hammer 
and  chisel  like  an  experienced 
sculptor.  The  required  re- 
moval of  a  frozen  nut  or  bolt 
to  separate  a  valuable  piece  of 
equipmenl  from  an  inde- 
scribable or  unworthy  piece 
of  metal  requires  talent  if 
damage  rs  to  be  negligible.  In 
the  first  place^  a  professional 
cannot  spend  a  lot  of  time  in 
dismantling  equipment.  His 
time  and  profit  margin  isn't 
that  much.  His  methods  may 
be  crude,  bui^  when  it  counts, 
he  has  the  delicate  touch  of 
an  artist 

When  removing  the  parts 
you  desire  for  the  project  you 
have  in  mind,  go  one  step 
further.  Completely  strip 
down  the  unit  at  the  same 
time.  This  will  keep  storage 


problems  from  arising. 

Lay  out  the  tools  you  will 
need  and  have  a  seat.  There 
are  many  ways  to  keep  parts 
separated.  It  depends  on  how 
much  stripping  you  intend  to 
do.  The  cheap  way  is  to 
gather  a  bunch  of  milk  car- 
tons. Cut  them  in  half  and 
wash  them  out.  Use  as  many 
as  you  need, 

A  tool  caddy  is  advisable, 
loaded  with  every  tool  imag* 
inable.  Stay  away  from  un* 
soldering  items  when  strip- 
ping. Save  those  until  later 
when  you  are  ready  to  use 
them.  Cut  them  out  with  a 
pair  of  large  diagonal  pliers,  A 
great  time-saver  is  the  use  of 
nul*driversp  spintites,  etc. 
These  do  not  preclude  ihe  use 
of  a  socket  set  at  times,  but 
normally  they  wilt  suffice  in 
most  cases  when  the  nuts  are 
securing  terminal  strips  and/ 
or  transformers^  tube  sockets, 
and  other  nut-and-bolt 
secured  Items.  Allen  wrenches 
are  a  must  for  knobs  and  gear 
drives  where  needed.  Nothing 
is     more     aggravating     than 


being  midway  into  a  stripping 
project    and   finding  a   gear 

that  is  preventing  the  removal 
of  an  entire  mechanism.  All 
that's  required  is  the  correct 
Allen  wrench  ...  and  you 
don't  have  it. 

If  the  equipment  being 
stripped  is  small,  then  the 
tool  complement  can  follow 
in  order,  Electronic  equip- 
ment lools  used  for  disman- 
tling and  repairing  equipment 
may  be  all  that's  necessary.  If 
the  equipment  h  large,  addi- 
tional lools  may  be  required. 

If  the  item  is  a  piece  de- 
signed strictly  for  military 
application,  then  there  will  be 
some  specially  designed 
screws,  nuts,  and  bolts  that 
should  be  removed  with  a 
hammer  and  chisel.  Leave 
them  until  last  Even  if  you 
have  the  special  tool,  don't 
waste  your  lime.  You 
wouldn't  want  to  use  them  in 
a  project  anyway- 
Wiring  harnesses  do  not 
serve  any  purpose  unless  you 
need  hookup  wire.  Removing 


114 


the  entire  harness  at  one  time 
is  sometimes  easier  than  re- 
moving and  disconnecting 
each  item  as  it  is  stripped.  If 
the  terminal  strips  and  asso- 
ciated plugs  are  not  wanted, 
then  leave  them  connected 
and  remove  the  entire  wiring 
assembly  by  unscrewing,  un- 
bolting, and  cutting.  When 
this  is  out  of  the  way,  all 
other  parts  are  easily  acces- 
sible, and  dismantling  is  much 
easier, 

A  reminder  here  about  the 
removal  of  transformers: 
Trace  the  wiring  and  mark 
the  connections  before  re- 
moving. Many  will  follow  the 
standard  color  code  of  black 
for  primary,  red  for  second- 
ary high  voltage,  red  and 
yellow  for  center  tap,  and 
green  for  filament,  but  don't 
count  on  it  Some  artistic 
devils  can  get  hold  of  the 
design  and  color  leads  to  look 
like  modern  arL  Trace  the 
wiring  just  to  be  sure  before 
disconnecting  the  trans- 
former. The  same  thing 
applies  to  any  item  that  has 
more  than  two  leads  and 
depends  on  any  type  of  color 
code  for  identification. 

There  are  always  some 
limitations  each  do-it-yourself 
technician  places  upon  him- 
self  It  may  be  coil  winding  or 
some  other  technical  item 
that  requires  special  equip- 
ment or  a  tot  of  time  to  build 
and  is  easily  acquired  for  a 
small  sum  of  money  at  the 
local  parts  house.  Another 
example  is  tube  sockets.  The 
common  seven-  and  nine-pin 
sockets  can  be  reused  if  you 
are  willing  to  take  the  time  to 
clean  the  individual  pins  after 
removal  from  the  chassis 
being  stripped 

The  most  usable  items  that 
you  can  remove  in  quantity 
will  be  the  resistors  and  ca- 
pacitors. You  will  never  have 
enough  of  these  items.  The 
more  you  get,  the  more  you 
find  you  will  need.  Removal 
of  these  items  can  be  done 
rather  speedily. 

Where  tube  sockets  and 
terminal  strips  are  not  impor- 
tant, a  fast  method  of  re- 
moval is  to  cut  the  tabs  of  the 
terminal    strips   and    sockets 


The  junkee  who  sai^s  e  wry  thing  needs  a  place  to  put  it  If  you  ^e  an  organ  iied  junkee,  pigeon 
ho/eSf  like  these,  are  ideaL  If  not,  it  may  take  a  month  to  find  a  particular  item. 


instead  of  the  resistor  wires 
and  capacitors.  You  can 
remove  the  solder  and  small 
piece  of  connection  later 
This  also  allows  for  further 
and  faster  stripping. 

The  junkee  has  arrived  at 
his  destination.  All  reusable 
parts  have  been  removed  and 
all  that  remains  is  a  bunch  of 
wire  and  assorted  metal 
chassis  bits  and  pieces.  The 
junker's  turn  is  next.  The 
funkor  will  take  the  same 
piece  of  equipment  and  spend 
just  a  few  minutes  and 
accomplish  the  same  thing. 
He  will  get  his  desired  part 
and  either  throw  the  rest 
away  or  store  it  for  later  use, 
or  strip  it  to  the  point  where 
a  salvage  metal  buyer  wi!I 
accept  it  There  are  many 
hobbyists  who  enjoy  strip- 
ping as  much  as  they  do 
building.  If  that  is  your  forte, 
then  make  it  pay. 

You  must  acquire  a  most 
important  toot  to  keep  with 
you  at  all  times  —  a  magnet 
This  will  aid  you  no  matter 
where  you  beg,  borrow,  buy, 
or  steal  your  material.  Separa* 
tion  of  the  different  types  of 
metal  (copper,  iron,  steel, 
stainless  steel,  bronze,  etc.)  is 
a  must  Also,  to  make  it 
worthwhile,  don't  attempt  to 


sell  the  metals  unti!  you  have 
a  sizable  amount  Of  course, 
it  depends  on  the  type  of 
metat  Where  ten  pounds  of 
clean  copper  wire  may  bring 
you  four  dollars,  the  same  ten 
pounds  of  aluminum  may 
bring  one  dollar  and  sixty 
cents  ($1.60)  at  fifteen  cents 
per  pound.  The  prices  may 
fluctuate  from  day  to  day, 
but  usually  not  more  than  a 
few  cents  a  pound,  although 
prices  for  clean  copper  in  past 
years  has  risen  to  over  a 
dollar  a  pound  and  fallen 
back  to  as  low  as  thirty  cents 
a  pound. 

Clean  metals  will  bring  as 
much  as  MO  percent  more 
than  what  are  known  as 
**d!rty  meuls."  Dirty  metals 
are  those  that  still  have 
screws,  bolls,  rubber,  weather 
stripping,  or  other  materials 
which  are  still  attached 

For  speed,  the  hammer- 
and-chisel  technique  is  used. 
The  simplest  way  is  to  take 
the  chisel  and  hold  it  with  a 
pair  of  pliers.  This  eliminates 
split  fingers,  but  it  does  not 
eliminate  the  tiny  slivers  of 
metal  that  occasionally  fly 
from  the  head  of  the  chisel. 
Gloves  and  a  pair  of  safety 
goggles^  if  you  don't  wear 
glasses,  should  be  used  if  you 


intend  to  do  much  chiseling. 

When  you  have  everything 

removed^    check     the    metal 

with  your  liiile  magnet.  Any- 
thing it  will  stick  to  is  iron 
and  should  be  removed.  This 
Is  the  main  purpose  of  the 
magnet.  Of  course,  the  mag- 
net will  not  indicate  the 
presence  of  brass  or  copper 
which  should  also  be  separ- 
ated.  Yd  low- colored  metal 
will  indicate  brass,  while  the 
reddish  varieties  are  more 
likely  copper.  Stainless  steel 
and  lead  also  bring  a  nice 
scrap  price. 

You  can  throw  away  the 
lube  sockets,  crushed  coils* 
resistors  and  capacitors  not 
saved,  and  knobs  (unless  they 
have  brass  inserts).  A  smart 
blow  from  a  hammer  will 
crack  away  the  outer  plastic 
covering  of  the  knob  and 
leave  a  clean  piece  of  brass- 
Don't  expect  much  from 
your  iron;  that  wilt  be  on  the 
low  end  of  the  pay  scale  {two 
or  three  cents  a  pound). 
When  you  have  accumulated 
thirty  or  forty  pounds  or 
more  of  copper,  brass, 
aluminum^  etc,  you  might  be 
surprised  at  the  price  it  will 
bring.  Remember  to  keep  it 
separated  and  free  of  iron. 
One   last   reminder:    Wire 


115 


must  be  completely  clean  of 

ail  insulation  and  attach- 
ments,  including  plugs,  clips, 
brackets,  etc.  This,  of  course, 
is  your  highest  paying  metal, 
so  extra  care  should  be  taken. 
In  most  states,  the  method  of 
burning  the  insulation  off  the 
wire  is  forbidden  due  to  the 
pollutants  released  by  some 
electronic  insulation,  al- 
though this  does  not  stop 
many  illegal  smelter  opera- 
tions and  backyard  burners. 
The   backyard  burners   (bar- 


becue pits)  usually  get  away 
with  ft  because  of  the  small 
amount  cleaned  (ten  to 
fifteen  pounds)  at  a  time. 

The  junkor  should  be 
aware  of  the  copper  content 
of  television  yokes,  motors, 
and,  last  but  not  least,  trans- 
formers. Average  trans- 
formers with  an  open  core 
winding  will  contain  between 
thirteen  and  eighteen  percent 
of  the  total  weight  in  copper. 
Again,  the  easiest  method  of 
stripping  a  transformer  is  to 


burn  it  If  it*s  an  enclosed 
transformer,  remove  the 
outer  cover  and  throw  it  in 
the  fire,  if  regulations  permit. 
One  alternative  is  to  remove 
the  wire  by  hand.  This  can  be 
a  difficult  and  tjme-consunrv 
ing  chore  if  it  is  an  iron-core 
transformer  with  inserts 
shaped  like  the  letter  W.  The 
easiest  method  is  to  saw 
through  the  inserts  and  slip 
them  out,  leaving  the  wire  to 
be  unraveled  by  hand. 

There     are     many     other 


ways  to  accomplish  the  same 
stripping  procedures  dis- 
cussed in  the  preceding  para- 
graphs, but  whatever  method 
you  discover  that's  easiest  for 
you  to  use,  do  it.  Not  only 
will  you  pocket  a  little  extra 
cash,  but  a  lot  of  that  old 
metal  will  find  its  way  back 
into  circulation,  and  someday 
your  efforts  may  be  remem- 
bered as  the  only  thing  that 
saved  the  beer  can. 

May  you  chisel  your  way 
to  glory.  ■ 


:ju   iroon^    If.fi'  t   •:  ver  '  r>ro  jfr 


1^' ."o 


1  * 


t e.  1 1    i\\ a   h Pi.]    v.. 3.x    3 h e   ::f h o a 


fmmpage  102 

everyone  give  their  QTH  as  well 
as  their  callsign.  Vm  sure  most 
of  the  old-timers  feel  the  same 
way, 

Russell  A,  Gariin  WSUKA 
Albuquerque  NM 


MORE  M1C0DER  MODS 

Re  the  MicoderTM  articles  in 
the  July,  1978  (page  90  by 
K3MPJ),  and  August,  1978 
(page  166  by  W4CUG)p  issues  of 

Getting  rid  of  the  555  timers 
for  tone  generation  is  easier 
than  building  a  PC  board  and 
buying  all  the  parts,  that  is, 
unless  you  have  a  well -stocked 
junk  box.  IHeath  has  a  kit  to 
make  the  Mlcoder  into  a 
Micoder  IL  It  is  riot  very  expen- 


sive and  includes  all  the  parts, 
it  uses  the  Mosfek  chip  and  TV 
color  crystal. 

Also,  to  get  rid  of  the  9- volt 
battery,  which  just  doesn't  last 
very  long  at  alL  I  did  it  a  ifttle 
more  easHy  than  K3MPJ. 
Unless  they  have  changed  the 
coiled  cord  in  later  models,  \\ 
contains  an  e>ctra  black  wire.  It 
is  connected  to  ground  al  each 
end  with  the  shield.  I  used  the 
same  zener  setup  that  MPJ  did, 
except  t  put  the  zener  and 
resistor  where  the  cord  comes 
into  the  radio  and  used  the  ex- 
tra black  wire  for  the  power 
conductor.  There  was  no 
change  in  the  fme  audio  quality 
of  the  Micoder  or  2036.  As  a 
side  benefit,  the  Mrcoder  is 
somewhat  lighter  without  the 
battery. 

I  hope  this  will  be  of  iotefest 


to  others  who  might  want  to 
make  these  modifications. 

Oscar  A.  Hayt  III  K5UBS 

Daltas  TX 


JAPANESE  JACKPOT 


] 


Japanese  folklore  says  that 
there  is  a  jackpot  day  in  each 
month.  The  day  I  find  73 
Magazine  in  the  mail  box  is  the 
day  for  me, 

I  especially  Nked  your  article 
"Radio  Row  Revfsited"  in  the 
past  August  issue.  I  would  like 
to  make  an  addition  to  Brad^s 
statement  that  **a  large  portion 
of  the  gear  on  display  here  is 
aimed  at  the  lucrative 
Japanese  Novice  market:  ten 
Watts  maximum,  phone  onfy, 
80,  40,  15.  and  10  meters  and 
VHF." 


The  Japanese  version  of  the 
FCC  has  regulations  applh 
cable  to  four  different  amateur 
radio  licenses. 

1.  Novice:  Bands  and   modes 
same  as  the  regulations. 

2.  Telegraph   class:   Same   as 
Itovice  plus  CW. 

3.  Second   class:  3-500Z  x   2^ 
maximum. 

4.  First  class:  Henry  4K*Ultra, 


and  up. 

I  have  never  seen  a  ten-Walt 
rig,  except  at  a  ham  shop 
display,  and  in  my  own  shack 
when  I  was  a  Novice. 

Mitch  H.  Ono  JF3JKK 
Otsu  City,  Japan 

WONDERFUL  RESPONSE 

About  a  year  ago  our  club 
asked  you  for  a  donation  for  our 
first  club  raffle.  The  response 
was  wonderful  and  the  raffle 
became  a  great  success.  Our 
goal  was  modest:  $200  lot  the 
treasury.  We  surpassed  that 
with  your  help. 

As  a  club  sponsored  by  the 
Nassau  County  Department  of 
Parks  and  Recreation,  we  do 
not  charge  any  membership 
dues  or  fees.  The  modest 
treasury  helps  keep  us  on  the 
air,  and  in  postage.  We  are  not 
asking  for  a  hand  again,  but  we 
may  do  so  in  the  future. 

Please  pass  on  the  word  that 
students  are  always  welcome 
in  our  Novice  and  GenefaiiAd' 
vanced  classes  each  Monday 
at  7:30  pm. 

Gene  Blanck 
East  Meadow  NY 


Corrections 


It  was  called  to  my  attention 
that  one  reader  thought  that 
there  was  the  possibility  of  eye 
damage  from  the  use  of  the  In- 
stant Engraving  system  de- 
scribed in  the  July  issue  (Let- 
ters. September,  1978,  p.  127). 
He  cites  the  tact  that  carbon 
arc  lights  are  used  to  generate 
ultraviolet  radiation  for  use  In 
exposing  photosensitive  mate- 
rials. Of  course,  some  form  of 
eye  protection  Is  to  be  used 
under  those  conditions.  The 
key  words  are  carbon  arc. 

Please  note  the  third  column 


on  page  59  (July,  1978), ", . .  the 
voltage  should  be  kept  below 
the  point  where  an  arc  can  be 
struck  and  maintained."  Photo 
0  shows  the  rod  glowing  from 
simple  i2r  tieating,  not  the 
veritabitt^  inferno  contained  in 
an  arc.  the  light  given  off  dur* 
ing  the  engraving  process 
should  be  no  more  or  less  harm* 
ful  than^  that  of  any  other  in- 
candescent light  of  similar 
light  value.  As  in  any  incandes- 
cent tight  source,  a  con- 
siderable amount  of  energy  is 
dissipated  In  the  form  of  heat, 


with  only  a  smalt  portion  used 
to  generate  visibie  or  invisible 
radiation, 

I  regret  any  confusion  that 
there  may  have  been  concern- 
ing the  above  point, 

Ev«rt  Frultman  W7RXV 
Phoenix  AZ 


Please  note  a  correction  to 
my  article  'Triple  Threat/* 
which  appeared  in  your  Oc- 
tober Issue.  On  page  1 33,  line  2, 
column  2  should  read  ''leled 
phono  or  phono". 

Ralph  E  Delligattl  K30MY 
Qalthersburg  MD 


Ham  Help. 


I  would  like  to  know  if  anyone 
knows  of  a  commercially  run 
school  which  a  person  can  at- 
tend in  order  to  learn  how  to  ob- 
tain an  amateur  radio  license, 

Carl  M,  Sullivan 

RR  24,  Box  383 

Terre  Haute  IN  47802 


I  need  a  schematic  and/or 
manual  for  the  Harris-lnterdala 
COPE  1035  SelectriC'based  ter- 
minal. I  will  pay  for  photocopy 
and  shipping. 

Jeff  Duntemann  WB0MQY 

6208  N,  Campbell  Ave, 

Chicago  IL  60659 


lie 


'k\ 


■CO 


N. 


FAA 


'fM*:^* 


4C 


341 


BO 

A 


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TU^t* 


,G     "•    -^   "" 


e*i*p 


po>t« 


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ENRY  RADIO'S 


NE 


RVMtlJ/ Of^  FINE  AMPORERS 


RADI 


ii^ 


*h©  ZKD-5  and  2K*4  linear  ampiuters  compieieiy  tuiIiII  th© 
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IMlfKt  to 


tmM^~ 


H 


WUfiam  R.  Stocking  WBVM 
1030  Weidman  Road 
Manchester  MO  630 II 


Tuned  Feeders 
and  Other  Good  Stuff 


who  needs  coax? 


AS  you  know,  other 
things  being  equal, 
the  success  of  your 
amateur  radio  station 
depends  upon  the  quality 
of  its  antennas.  Is  your 
antenna  a  coax-fed  dipole? 


If  so,  why?  Is  it  because  it  is 
the  easiest  kind  of  antenna 
to  put  up  and  get  on  the  air 
with?  Is  it  because  it  can  be 
brought  into  the  house 
through  one  small  hole?  Is 
it  because  other  kinds  of 


:•  *f 


ff 


Vertical  lepp"'  aritenna  for  20  meter  CW. 


antennas  seem  compli- 
cated and  difficult  to 
understand?^ 

From  on-the-air  descrip- 
tions of  antennas,  one  gets 
the  impression  that  most 
amateurs  feed  their  anten- 
nas with  coax.  This  was  not 
always  so.  Before  coax  ex- 
isted, amateur  operators 
designed  and  built  ex- 
cellent antennas  using 
open-wire  tuned  feeders. 
Some  antennas  used  no 
feeders  at  all. 

The  purpose  of  this  arti- 
cle is  to  present  some 
''antenna  axioms"  along 
with  some  basic  antenna 
theory  and  to  explain  how 
to  use  these  ideas  to  build 
effective  antennas  that  are 
not  fed  with  coax.  (Coax  is 
used  only  between  the 
transmitter  and  the  anten- 
na tuner.)  Building  and  ex- 
perimenting with  antennas 
is  fun  and  good  experience. 

Antenna  Axioms 

1.  The  antenna  system 
should  be  resonant  at  the 
frequency  being  used. 

2.  The  rf  from  the 
transmitter  must  be  effec- 
tively put  into  the  antenna. 

3.  "There  is  no  sub- 
stitute for  height."  The 
higher  the  antenna,  the  bet- 
ter. The  high-current  part 
[or  parts)  of  the  antenna 
should  be  as  high  as  pos- 
sible. 


4.  Other  things  being 
equal,  full-length  antennas 
work  better  than  do  shorter 
antennas  that  have  been 
made  ''electrically  longer" 
by  means  of  "loading 
coils.'' 

5.  Quarter-wavelength 
vertical  antennas  use  a 
good  ground  or  group  of 
quarter-wavelength  radtals 
for  the  other  half  of  the 
antenna.  Radials  buried  in 
the  ground  are  often  used. 
The  greater  the  number  of 
radials,  the  better  the 
antenna  works.  At  easy-to- 
attain  heights,  vertical 
antennas  have  a  lower 
angle  of  radiation  than  do 
horizontal  antennas.  This 
makes  them  good  for  DX, 

6.  The  transmitter's  har- 
monics should  be  pre- 
vented from  getting  into 
the  antenna. 

Basic  Antenna  Theory  and 
Applications 

A  half-wave  resonant 
antenna  has  high  voltage  rf 
on  its  ends  and  high  rf  cur- 
rent in  its  center.  (See  Fig. 
1.)  The  antenna  can  be  fed 
rf  voltage  at  one  end,  or  it 
can  be  fed  rf  current  in  its 
center.  (A  half-wave  anten- 
na fed  in  its  center  by  coax 
is  a  current-fed  antenna.) 
An  antenna  can  be  voltage- 
fed  by  bringing  one  end  in- 
to the  shack  and  connect- 
ing it  to  a  parallel-tuned 
^'antenna    tank"    tuner 


118 


Tuned  doublet  antenna  66  feef  either  side  of  center. 


which  is  link-coupled  to  the 
transmitter  The  tuner  is 
composed  of  a  coil  and 
variable  capacitor  which 
will  tune  to  the  frequency 
of  the  transmitter.  The 
rotating  plates  of  the 
variable  capacitor  are  con- 
nected to  ground.  The 
stator  plates  wilt  be  ''hot" 
with  rf  voltage,  and  the  end 
of  the  antenna  is  con- 
nected to  the  stator  plates. 
One  side  of  a  neon 
tube  is  connected  to  the 
antenna  to  indicate  the 
presence  of  rf  voltage 
when  the  coil  is  tuned  to 
resonance,  (See  Fig.  20  The 
antenna  shoutd  go  out 
from  the  shack  and  be 
strung  up  as  high  as  pos- 
sible, (The  length  of  a  reso- 
nant half-wave  antenna  is 
found  bv  applying  the  for- 
mula:   Length    in   feet    = 


468/frequency  in  mega- 
hertz.) If  the  antenna 
length  is  for  one  of  the 
lower  frequency  amateur 
bands,  it  can  be  used  on  its 
harmonics  for  the  higher 
frequency  bands.  (An 
antenna  132  feet  long,  for 
use  on  the  33  MHz  band, 
will  also  work  on  7  MHz,  14 
MHz,  21  MHz,  and  28  MHz 
by  tuning  the  antenna 
tuner  to  these  higher  fre- 
quencies. Plug-in  coils  can 
be  used  for  the  various 
bands,) 

An  antenna  may  be  cur- 
rent-fed if  the  center  of  the 
antenna  is  brought  into  the 
shack.  In  this  case,  the  coil 


Antenna  grounding  switch  on  tuned  doublet's  feeders.  The 
switch  is  in  place  for  use  on  the  am 


and  variable  capacitor  are 

connected  in  series  with 
each  other  and  in  series 
with  the  rf  "center  ends"  of 
the  antenna,  (See  Fig.  3.) 
This  kind  of  antenna  can  be 
conveniently  used  if  the 
shack  is  on  the  second 
floor  of  a  house.  One  half 
of  the  antenna  can  be  ver- 
tical and  the  other  half  of 
the  antenna  can  slant 
down  and  out.  (Two-by- 
fours,  or  furring  strips 
screwed  together  with  a 
long  bamboo  fishpole  on 
top,  make  a  good  support 
for  a  vertical  wire.)  This 
kind  of  antenna  illustrates 
the  principle  of  series  tun- 
ing for  rf  current.  The  end- 
fed  antenna  utilizes  the 
principle  of  parallel  tuning 
for  rf  voltage. 

When  an  endfed  anten- 
na is  used  on  its  harmonics, 
provision  can  be  made  for 
lengthening  the  antenna  in- 


---e 


side  the  shack  to  make  it 
work  better  on  the  har- 
monics.2 

It  is  good  to  have  your 

antenna  as  high  and  in  the 
clear  as  possible.  For  this,  a 
means  of  feeding  the  rf  to 
the  antenna  through  wires 
is  necessary.  (See  Axioms  2 
and  3.)  There  are  several 
kinds  of  wire  transmission 
tines  that  can  be  used.  The 
most  efficient  transmission 
line  is  the  open-wire  type. 
(Efficient  means  with  the 
least  loss  per  hundred  feet 
of  line.)  Next  most  efficient 
is  the  transmitter-type 
twinlead.  After  this  are  the 
other  kinds  of  twinlead  (TV 
twinlead).  The  least  ef- 
ficient transmission  lines 
are  the  small-diameter 
coaxial  cables  such  as  the 
RG-58/U  and  the  RC-59/U.3 
Before  coax  was  avail- 
able, zeppelin-type 
("zepp")  tuned  feeders 
were  often  used  to  take  the 
rf  from  the  shack  to  the 


RF.  FROM 
THANSMITTtR 

i 


fig.  h  Rf  voltage  and  cur- 
rent distribution  of  a  half- 
wave  resonant  antenna. 


R.F.  FROM  TRANSMITTER 


Fig.  2,  Feeding  rf  voltage  to  the  end  of  a  resonant  antenna 
Iparallet'tuned  coil  to  give  rf  voltage). 


Fig.  3.  Feeding  rf  current  in- 
to the  center  of  a  half-wave 
resonant  antenna  (series 
tuning  for  rf  current). 


119 


*'Singie-ended''  antenna  tank  tuner  for  end  fed  (vohage) 
antennas  [switch  for  transmitter  or  receiver,  etc.l 


i  f 


antenna.  The  '  zepp 
antenna  consisted  of  a 
resonant  antenna  that  was 
fed  by  an  antenna  that  was 
a  hatf-wav^length  long, 
folded  back  on  itself,  and 
fed  rf  current.  In  the  case 
of  a  dirigible  or  zeppe]in, 
the  antenna  was  sus- 
pended below  the  air- 
ship, as  in  Fig.  4.  When 
used  in  an  amateur  radio 
station,  the  tuned  feeders 
go  up  from  the  shack  to  the 
end  of  the  antenna.  (See 
Fig.  12)  Electrically,  the 
tuned  feeders  are  an  anten- 
na folded  back  on  itself, 
and  one  end  of  the  tuned 
feedline  is  connected  to 
one  end  of  the  antenna. 
The  other  end  of  the 
feedtine  is  not  connected 
to  anything,  except,  of 
course,  the  insulators  that 
support  it  There  is  no  rf 
radiated  from  the  tuned 
feeders  because  the  rf  field 
of  one  feeder  cancels  the  rf 
field  of  the  other  feeder. 
The    length    of    the    zepp 


antenna  itself  should  be 
5%  longer  than  468/f(mH2) 
because  of  ''end  effects/'^ 
The  "tuned  doublet"  is 
another  type  of  antenna 
that  uses  tuned  feeders. 5 
This  antenna  is  better 
balanced  than  the  zepp 
because  both  ends  of  the 
tuned  feeders  are  con- 
nected to  the  antenna, 
each  to  the  same  length  of 
wire.  (See  Fig.  5.)  The  tuned 
doublet  can  be  used  on 
harmonfcs  of  its  f  undamen* 
tal  length.  Furthermore,  it 
has  a  gain  of  about  1,9  dB 
at  right  angles  to  the  anten- 
na  when  it  is  tuned  to  its 
second  harmonic.  The 
antenna  also  has  some 
gain,  as  compared  to  a 
dipole,  when  it  is  used  on 
higher  harmonics  at  angles 
less  than  90  degrees  from 
the  antenna.  If  the  station 
can  have  only  one  antenna, 
a  tuned  doublet  would  be 
an  excellent  allband  anten- 
na- Cut  for  the  lowest  fre- 
quency band  to  be  used,  it 


ANTENNA 


Fig,  4.  The  original  ''zepp''  antenna. 


would  be  operated  on  its 
harmonics  for  the  higher 
frequency  bands.^  An  ex- 
cellent tuned  doublet 
antenna  66  feet  either  side 
of  65-foot  open-wire  tuned 
feeders  was  used  in  several 
field  day  contests.  It 
worked  well  on  80,  40,  20, 
and  15  meters.  [It  was  not 
tried  on  10  meters,  but 
probably  would  have 
worked  there,  also,^ 

Antenna  Tuners 

A  tuned  feeder  antenna 
system  requires  an  antenna 
tuner   between    the   trans- 
mitter   and    the    tuned 
feeders,^  The  most  simple 
antenna  tuner  for  balanced 
tuned  feeders  consists  of  a 
coil  tuned  by  a  split-stator 
variable    capacitor,    link- 
coupled  to  the  output  of 
the      transmitter.      The 
feeders  are  connected   to 
the   stator  plates  of  the 
variable   capacitor.   (See 
Fig,  6. J  The  coil  and  capaci- 
tor  should    be   of    such 
values    as    may   be   tuned 
to   the    transmitter's   fre- 
quency, (Plug*in  coils  can 
be  used  to  change  bands.) 
This  tuner  works  well  if  the 
length  of  the  antenna  and 
its  feeders  is  such  that  the 
ends  of  the  feeders  in  the 
shack    should    be   fed    rf 
voltage.   However,   with 
other    feeder     lengths, 
variable   capacitors   must 
be  placed  in  series  with  the 
feeders,  and  you  have  the 
tuner  of  Fig.  7,  Since  tuned 
feeders   are   of   the   same 
length    (balanced),    the 
series-variable   capacitors 
are   ganged    together  and 
tuned  with  one  dial.  (These 
capacitors   must  be  elec- 
trically   insulated    from 
each  other  when  ganged.) 
This    tuner    (with    plug*in 
coils  for  changing  bands) 
makes  possible  the  use  of 
tuned  feeders  of  practical- 
ly any  convenient  length.  A 
neon    tube   connected    to 
one    stator    of    the    split- 
stator    variable    capacitor 
(or  leaning  against  one  or 
both  of  them)  helps  in  the 
initial  tune-up  of  the  anten- 
na system,  A  field  strength 


meter  located  not  near 
the  antenna  tuner  should 
be  used,  and  the  antenna 
system  tuned  for  the 
greatest  field  strength  in- 
dication. 

With  this  antenna  tuner, 
an  swr  meter  connected 
between  the  transmitter 
and  the  antenna  tuner  may 
show  a  rather  high  swr,  but, 
when  the  field  strength 
meter  shows  the  highest 
reading,  the  swr  will  be  the 
lowest  The  use  of  coax-fed 
antennas  and  the  limited 
impedance  output  range  of 
many  transmitters  have 
made  amateurs  worry 
about  swr,  and  nearly  all 
hams  use  swr  meters.  To 
reduce  the  swr  between 
the  transmitter  and  the 
antenna  tuner,  a  large 
variable  capacitor  can  be 
added  in  series  with  the 
primary  coil  of  the  tuner, ^ 
This  enables  the  operator 
to  obtain  a  very  low  swr 
reading,  if  this  is  necessary 
to  make  either  him  or  his 
transmitter  happy,  (See  Fig, 
8,)  This  tuner  worked  so 
well  on  field  days  that  one 
of  the  field  day  operators 
called  it  the  "old  reliable" 
antenna  tuner,  (This  was 
even  before  the  variable 
capacitor  was  added  in 
series  with  the  primary.)  In 
the  "old  reliable"  tuner,  a 
two-turn  coil  made  of 
number  12  house-wiring 
wire  is  used  for  the 
primary.  This  wire  is  stiff 
enough  to  hold  itself  in 
place.  The  primary  coil's 
diameter  is  larger  than  that 
of  the  plug-in  coils,  and 
these  coils  are  plugged  in 
right  through  the  primary 
coil.  (See  Fig.  9  and 
photograph.)  Another 
tuner  has  plug-in  coils  with 


AMTEMUIt 


TUhftD  FEEOEHS 

^  (GO  TO  ANTENNi 
TUhlER> 


Fig.    5.    Center  fed   tuned 

doublet  antenna  (often  irh 
correctly  called  a  ^'center- 
fed  zepp"]- 


120 


a  separate  primary  for 
each  secondary.  This  tuner 
works  well,  but  the  swr  is 
not  quite  as  low  as  with  the 
"old  reliable''  antenna 
tuner. 

This  type  of  tuner, 
especially  if  built  with  junk 
box  or  scrounged  parts,  is 
inexpensive  but  effective. 
Some  other  tuners  such 
as  the  DenTron  Super 
TunerTM  ($129  50)  or  the 
Universal  Transmatch  of 
the  ARRL  Antenna  Book 
work  well  with  tuned 
feeder  antenna  systems, 
but  the  "old  reliable"  tuner 
does  it  with  a  lower  swr 

Some  amateurs  may  ob- 
ject  to  having  to  adjust  the 
three  dials  on  the  antenna 
tuner.  In  practice,  after  C2 
and  C3,  on  one  dial,  and  C4 
are  adjusted,  only  CI  must 
be  readjusted  when  mov* 
ing  from  one  part  of  a  band 
to  another. 

The  drawings  and  dia- 
grams in  Figs.  10  through 
17  show  the  dimensions 
and  arrangements  of  a  few 
non-coax-fed  antennas. 


Many  other  tuned  feeder 
antenna  systems  can  be 
designed.  Use  your  think- 
ing and  imagination.  Al- 
though open-wire  feed  line 
is  the  best  kind  to  use, 
good  quality  300-Ohm 
twiniead  works  very  well.  It 
can  be  brought  into  the 
house  under  a  window 
without  having  lo  drill 
holes. 

For  lightning  protection, 
provision  should  be  made 
for  grounding  the  feedline 
outside  of  the  house  when 
the  antenna  is  not  in  use. 

A  balanced  feeder  an- 
tenna tuner  such  as  the 
"old  reliable"  will  work  as 
the  series  tuner  for  the 
"center  of  the  antenna  in 
the  shack"  arrangement  by 
opening  out  the  plates  of 
the  split  stator  variable 
capacitor  and  tuning  with 
the  ganged  series-variable 
capacitors.  This  kind  of 
tuner  can  also  be  used  for 
voltage  feeding  the  end  of 
an  antenna  in  the  shack. 
Short  out  one  of  the  split 
stator  variable  capacitors 


ft F    FROM 


K  ^    ^  ROM  j^^ 


CI 


TO  BALANCED  TUNtD  FEEOEBS  OF 
CDHHtCT    LENCTH   FOfl  VOiUtGE    FEED 


I 


Fig.   6.   Antenna   tuner  to   voltage-fed  balanced  tuned 
feeders. 


It  F   FfTOH 


e 


P^ 


i^  C» 


I 
t 
I 
I 
I 

} 


BALANCED  TUNEQ  FEEDERS 
AMY  LENOTH 


^^ 


F/g,  7.  Antenna  tuner  for  balanced  tuned  feeders  any 
length. 


C£   . 


A 


rmmsHiTTe 


iTTCit      V 


3 


c* 


I * 


^ 


Cf 


SfliLANCEO    TijNEO    FEEQEHS 


t4  C3/ 


Fig.  8,  Antenna  tuner  for  balanced  tuned  feeders  any 
length,  with  a  vanable  capacitor  is  series  with  the  primary 
to  reduce  the  swr  between  the  transmitter  and  the  tuner. 


Back  view  of  single-ended  voltage-fed  tuner.  This  shows 
two  coax  connectors  switched  from  the  front. 


and  connect  the  antenna 
to  the  stator  plates  of  the 
other  side  of  the  variable 
capacitor.  A  neon  tube, 
one  side  of  which  is  con- 
nected to  the  antenna,  will 
indicate  the  rf  voltage 
when  the  coil  rs  tuned  to 
resonance  at  the  transmit- 
ter's frequency. 

You  may  ask,  "Why 
should  I  go  to  all  the 
bother  of  building  a  three- 
dial  antenna  tuner  and  a 
tuned  feeder  antenna 
system?"  "What  does  a 
tuned  feeder  system  ac- 
complish that  is  not  ac- 
complished with  my  pres- 
ent antenna?"'  One  impor- 
tant accomplishment  of  a 
balanced  tuned  feeder 
system  is  that  it  can  be 
tuned  to  exact  resonance 
at  any  frequency  in  any 
band  for  which  the  antenna 
is  designed.  For  example, 
the  80  meter  band  extends 
from  3500  kHz  to  4000 
kHz.  The  resonant  length 
for  3500  kHz  is  over  ISSVa 
feet  The  resonant  length 
for  4000  kHz   is  only  117 


.'1 


e 


3 


-^?-^ 
'      I 


1 
I 
I 


if^ 


Fig.  8[al  Using  a  center- 
tapped  coil  in  place  of  the 
split  stator  capacitor  to  ob- 
tain a  balanced  rf  output 


feet.  A  coax-fed  antenna  of 
one  length  cannot  be  reso- 
nant at  both  ends  of  the 
band.  With  a  centerfed 
doublet,  using  tuned 
feeders,  the  antenna 
system  can  be  made  reso- 
nant in  any  part  of  the 
band,  thus  fulfilling  the  re- 
quirement of  Antenna  Ax- 
iom 1, 

Another  important 
feature  of  a  tuned  feeder 
antenna  system  is  that  the 
rf  is  effectively  taken  from 
the  transmitter  to  the 
antenna  [Antenna  Axiom 
2). 

Another  advantage  of  a 
tuned  feeder  antenna 
system  is  that  the  antenna 
tuner  effectively  prevents 
transmitter  harmonics 
from  getting  into  the  anten- 
na and  being  radiated  (Ax- 
iom 6).  Coax^fed  dipoles, 
coax-fed  trap  dipoles, 
coax-fed  parallel  dipoles, 
and  coax-fed  trap  vertical 
antennas    all    accept    and 


Fig,  9,  Antenna  coil  plugged 
in  through  the  heavy  wire 
self-supporting  primary 
coiL 


121 


"Old  reliable'' antenna  tuner  —  front  view.  This  shows  the 
neon  tube  and  the  80  and  15-10  nr}eter  coils. 


radiate  any  transmitter  har- 
monics that  are  in  a  band 
for  which  the  antenna  is 
designed,  and  which  are  in 
the  transmitter's  output,ici 
Multiband  operation  is 
effectively  accomplished 
with  a  tuned  feeder  anten- 
na  system.    An   antenna. 


designed  for  a  lower 
frequency  band,  is  used 
on  harmonicaliy-related 
higher  frequency  bands  by 
tuning  the  feeders  to  the 
harmonic  frequencies-i^ 

With  a  good  antenna 
tuner,  feeder  length  is  not 
criticaK  This  makes  possi- 


Fig.  TO.  33'ft.  verticat  and  334t  ''s/anter''  commg  into  a 
second-siory  shack.  Series  tune  both  for  40  meter  opera- 
tion (Fig.  Jl  For  20  meters,  voltage- feed  the  vertical  part 
only  (Fig,  21  For  15  meters,  feed  both  parts  in  series  (Fig.  3). 
The  antenna  can  also  be  made  to  work  on  80  meters  by  us- 
ing a  large  coil  in  the  series  tuning  arrangement 


Fig.  11,  An  in-the-shack  endfed  antenna.  Use  parallel' 
tuned  coil  with  plug-in  coils  for  each  band  (Fig.  2).  This 
will  work  on  80  meters  and  higher  frequency  bands  on  har- 
monics. See  reference  1  for  means  of  lenglhenmg  the 
antenna  for  harmonic  operation. 


ble  high  antennas.  (Anten- 
na Axiom  3). 

Tuned  feeders  can  be 
used  with  good  results  to 
feed  vertical  and  ground- 


plane  antennas  that  are 
half  vertical  and  half 
horizontally  Tuned  feed- 
ers have  worked  very 
well  with  a  Hustler  4BTV 


Fig.  12.  Endfed  "zepp"  antenna  for  80  meters  (CW).  Use 
balanced  feeder  tuner.  This  will  work  on  higher  frequency 
bands  (harmonic  operationl  Tune  feeders  to  the  frequen- 
cies of  the  higher  frequency  bands.  A  centerfed antenna  66 
feet  on  each  side  of  center  tuned  feeders  would  be  better, 
if  ali  parts  of  the  80  meter  band  are  to  be  used  (both  CW 
and  phonel 


''Old  reliable''  antenna  tuner 
plug-in  coil  arrangement 


—  side  view,  This  shows  the 


""Old  reliable*'  antenna  tuner  —  back  view.  The  two  coax 
connectors  and  front  switch  are  for  switching  the  tuner 

between  receiver  and  transmitter  or  for  switching  between 
two  transmitters. 


122 


Another  antenna  tuner  with  primary  coil  which  plugs  in. 


trap  vertical  antenna. 

For  amateurs  who  like  to 
talk  {or  boast)  about  their 
low  swr,  the  swr  between 
the  transmitter  and  the 
antenna  tuner  can  be 
reduced    to   a    very    low 


value  on  all  bands  with 
careful  adjustment  of  the 
tuner. 

Tuned  feeders  are  the 
best  kind  to  use  with  some 
kinds  of  beam  antennas. 
For  example,  to  use  a  W8J  K 


Fig.  13.  80  meter  tuned  doublet  operated  on  harmonics  for 
the  higher  frequency  bands.  Use  balanced  feeder  tuner. 
This  is  the  best  all-around  antenna  for  multiband  use.  (This 
is  the  WaBVU/W0VM  field  day  antenna.] 


M»t, 


Fig.  14.  Vertical  ''slanter'*  tuned  doublet  for  40,  20,  and  15 
meters.  Use  balanced  feeder  antenna  tuner.  It  also  works 
on  80  meters  with  the  80  meter  antenna  coil  in  the  tuner. 
Several  "slanters'^  could  be  used  and  spaced  radiaUy  to 
make  a  ground-plane  antenna  for  40,  20,  and  15  meters. 


VEItTtCAL  lfi1/2  II 


R  OR  wont 

lAl^S  EACH  Ifi  1/2fl 


Back  view  of  the  other  antenna  tuner 


flattop  beam  on  its  har- 
monics, tuned  feeders 
must  be  used.  Tuned 
feeders  make  it  possible  to 
use  V-beams  on  several  fre- 
quency bandsJ3 

If  the  radiating  element 
of  a  rotating  beam  antenna 
is  fed  with  tuned  feeders,  it 
can  be  tuned  to  exact 
resonance  on  the  frequen- 
cy being  used.  This  will 
make  the  antenna  work 
better  on  both  the  phone 
and  the  CW  frequencies. 

If  you  want  to  be  able  to 
have  good  QSOs  on  any 
frequency  within  an  ama- 
teur band,  if  you  want  to 
eliminate  any  fear  of  har- 
monic radiation,  and  if  you 
want  a  larger  percentage  of 
your  calls  to  result  in 
QSOs,  use  an  antenna  tun- 
er and  an  antenna  center- 
fed  with  tuned  feeders. 
You  will  be  pleased  with 
the  results. ■ 


*- 9H * 


ttu 


=i/ 


Fig.  15.  Cround-plane  antenna  for  20,  15,  and  10  meters. 
Use  balanced  feeder  antenna  tuner. 


TO 

JHfTCMH*     ^ 
tlfN£*1 


Fig.  16.  A  vertical  "endfire" 
bidirectional  beam  anten- 
na for  20,  15,  and  10  meters. 
Use  balanced  feeder  anten- 
na tuner. 


References 

1,  ^'Simple  Dipole  Antennas," 
Jim  Ffsk  W1HR,  Ham  Radio 
Horizorrs,  January,  1978,  pages 
18  through  26.  is  an  excellent 
article  on  coax-fed  antennas.  It 
describes  several  antennas,  in- 
eluding  parallel  dipoles  and 
trap  dipoles.  Much  useful  data 
rs  presented.  However,  starting 
on  page  21  is  a  section  called 
"Simple  multiband  antennas." 
This  states,  "There's  no  doubt 
that  the  most  efficient  (and 
sinriplest)  multiband  antenna  is 
a  half-wave  dipole  cut  to 
resonate  at  the  lowest  oper- 
ating frequency,  centerfed  with 
open-wire  transmisspon  line 
through  an  antenna  tuner/' 

2,  The  theory  of  the  need  for  ex- 
tra length  is  beyond  the  scope 


TO 
TuN£li 


35a 


Fig.  17.  A  "vertical  zepp" 
for  20  meter  CW.  Strung  on 
two  bamboo  fishpoles 
taped  together,  this  anten- 
na has  worked  into  Europe 
from  St  Louis,  Missouri,  us- 
ing a  Ranger  T,  with  only  80 
Waffs  dc  input  to  the  final 
stage.  The  antenna  was  at 
ground  level  and  the 
feeders  went  down  a  few 
feet  into  the  shacL 


123 


of  this  article.  For  a  practical 
means  of  changing  the  anten- 
na's length  inside  the  sliack, 
see  "A  "Stretcher'  for  Endfed 
Multiband  Wires/'  Howard  J- 
Hanson  W7MRY,  0S7",  July, 
1972,  page  32. 

a.  "Why  Coax?"  by  Ed  Wagner 
G3BI0,  13  Magazine, 
November.  1971,  page  96,  and 
Understandfng  Amateur  Radio, 
2nd  ed.,  ARRL,  chart  on  page 
121, 

4.  See  The  Radio  Handbook, 
1939  edition,  page  425.  "flattop 
length/'  Also  see  page  424,  Fig. 
12,  "The  evolution  of  a  zepp 


antenna/* 

5.  See  Understanding  Amateur 
Radio,  2nd  ed.,  pages  122.  123, 
"*Open-wire'  Feeders."  and 
page  264,  "The  Center-fed 
DIpole/'  (This  antenna  has 
often  been  erroneously  called  a 
"centerfed  zepp/') 

6.  See  *'Gee,  What^s  a  Zepp?" 
Charles  G.  Miller  W3WLX,  July, 
1975,  73  Magazine,  page  111» 
and  the  ARRL  Antenna  Book, 
pages  179  and  ISO,  "Centerfed 
Antennas/' 

7.  See  "A  Field  Day  to  Remem- 
ber/' Wiltlam  R.  Stocking 
W8BVU,    73  Magazine,   June, 


1969,  page  44, 

8-  A  *'transmatch"  Is  a  form  of 
antenna  tuner, 

9.  For  this  capacitor,  a  two*  or 
three-section  broadcast  band 
variable  capacitor  with  ail  sec- 
tions connected  in  parallel  can 
be  used.  I  had  no  swr  meter  for 
many  years  and  used  a  neon 
bulb  and  f  ieid  strength  meter  to 
tune  the  antenna  system  to 
resonance.  The  variable  capac- 
itor in  series  with  the  primary 
coil  was  added  after  i  obtained 
the  swr  meter.  Now,  as  do  other 
hams,  I  keep  the  swr  as  low  as 
possible. 


10.  See  the  ARRL  Antenna 
Book^  page  188,  "Harmonic 
Radiation  from  Multiband 
Antennas/* 

11.  See  ARRL  Understanding 
Amateur  Radio,  2nd  ed.,  page 
123,  "Muiltband  Operation" 
and  the  ARRL  Antenna  Book, 
page  179,  "Centerfed  Anten- 
nas." 

12.  See  the  ARRL  Antenna 
Book,  page  187,  "Combining 
Vertical  and  Horizontal  Con- 
ductors/' 

13.  See  the  ARRL  Antenna 
Book,  page  174,  ''Feeding  the 
V/' 


Looking  kVfest 


from  page  IB 

to  go  ahead  and  prosecute 
such  a  case?  To  get  them  to 
say:  Here  is  an  individual  that 
we  want  to  take  the  time  to 
prosecute? 

"There  have  been  some  In* 
teresting  things  that  we  have 
learned  In  working  on  this  one 
case.  The  first  questions  they 
have  asked  (federal  authorities) 
is  if  there  are  any  tapes  of  the 
individual  It  is  my  opinion  that 
although  section  605  of  the 
Communications  Act  of  1934 
states  that  the  privacy  provi- 
sion does  not  apply  to  amateur 
coffimynications,  and  I  have 
not  researched  it,  this  distinc- 
tion is  invalid.  There  is  no  ra- 
tional basis  to  hold  that  a  com- 
munjcation  by  a  poiice  officer 
on  a  radio  is  private  and  cannot 
be  revealed  to  a  third  party  and 
that  what  \  say  via  a  two  meter 
repeater  need  not  be  held  so. 
Stili,  when  you  get  down  to  the 
prosecution  of  these  cases,  you 
are  asked  if  you  have  any  tapes. 
Therefore,  I  have  recommend- 
ed to  several  repeater  owners 
who  have  tape-logging  systems 
(or  volunteers  recording  people 
among  the  usershipj  that  when 
jamming  starts  tapes  be  made 
and  a  log  (written)  be  kept  and  it 
all  be  documented.  It's  a  lot  of 
work,  admittedly. 

'I'm  presently  in  the  process 
of  meeting  with  the  FCC  in 
Long  Beach  (California)  to  find 
out  just  what  they  will  want 
from  the  amateur  to  go  ahead 
and  take  these  cases.  However, 
when  you  get  down  to  it,  it's  go* 
ing  to  t>e  basically  the  ama- 
teur's  job.  You  will  get  a  lot  of 
lip  service,  a  lot  of  excuses,  and 
if  you  convince  the  FCC  to  pros- 
ecute, then  you  have  to  con- 
vince the  U.S.  Attorney  to  act. 
Believe  me,  this  takes  pres- 
sure. Pressure  is  the  only  thing 
the  U.S,  Attorney  knows  (under- 


stands), In  our  ranks,  we  have 
such  pressure.  We  have 
amateurs  who  are  correspon- 
dents for  all  phases  of  the 
media,  including  major  news- 
papers and  television  net* 
works.  Amateur  radio  has  got 
to  learn  how  to  make  use  of  the 
members  of  the  service.  Be- 
lleve  me.  A  phone  call  from  a 
nationally-prominent  news  cor- 
respondent can  make  a  world 
of  difference  as  to  whether  a 
case  is  prosecuted.  This  is  one 
idea.  There  can  be  no  general 
rule.  However,  iet^s  phrase  a 
few  items  for  you  to  think 
about. 

**Let's  first  explore  how  we 
can  get  the  government  to  act. 
Number  one,  you  must  docu- 
ment what  has  taken  place. 
You  must  have  tape  recordings 
of  the  individual  and  his  ac- 
tivities. It  also  must  be  more 
than  once  (thereby  creating  a 
definite  pattern  of  behavior). 

*'You  must  have  a  DFing 
crew.  In  cases  of  repeater  jam- 
ming,  this  task  belongs  to  four 
or  five  (dedicated)  people. 
White  other  groups  might 
assist,  your  central  group 
should  be  four  or  five  people  of 
the  type  who  would  turn  in  their 
own  mother  if  need  be.  This  is 
t>ecause  you  have  situations 
where  people  (DFers)  spend 
time  trying  to  disprove  the  iden* 
tity  of  a  jammer  if  it  turns  out  to 
be  a  friend.  Also,  you  must  have 
security  (total)  within  your 
group,  since  premature  an- 
nouncements or  leaks  can  ruin 
such  activities  (prejudice 
future  litigation).  One  does  not 
sit  down  at  a  poker  table,  lay 
out  one's  hand  to  full  view,  and 
then  start  betting.  Handling 
malicious  interference  is  just 
that.  It*s  a  question  of  playing 
your  cards  just  right  and  know- 
ing when  to  make  the  right 
move. 

'Once   you   have   set   that 


4lj 


hypothesis,  you  can  then  pro- 
ceed to  build  your  case.  Docu- 
ment it.  You  must  actually 
document  exactly  how  you  did 
your  DFing.  When  you  get  into 
the  prosecution  of  such  a  case, 
the  federal  authorities  are  go- 
ing to  ask  this.  Also,  you  must 
be  able  to  show  that  your  DF 
equipment  is  working  accurate- 
ly, and  how  you  arrived  at  your 
conclusions. 

'*One  other  thing  that  I  would 
strongly  urge  those  into  DFing 
for  this  purpose  to  do  is  keep  an 
accurate  map  of  all  of  their 
bearings,  their  location  when 
taken,  the  dale,  and  the  time. 
This  can  present  a  pattern  and 
prove  a  case.  Once  you  have  all 
this»  you  then  have  a  basis  to 
go  to  the  FCC  and  request  their 
help.  As  1  said  earlier,  we  are 
currently  meeting  with  the 
Long  Beach  FCC  office,  coor- 
dinating our  efforts  so  that  all 
this  work  by  amateurs  will  not 
be  wasted. 

"It  is  my  opinion  that  the  U.S. 
Attorney  has  been  instructed 
by  the  Attorney  General  that 
amateur  radio  cases  of  the  type 
involving  malicious  interfer- 
ence are  1owest*case  priorities. 
I  think  you  must  face  the  fact 
that  this  is  what  their  feeling  is. 
They  feel  you  are  treading  In  an 
area  of  First  Amendment 
rights. , . 

^Therefore,  it  is  important  to 
have  some  way  of  protecting 
yourself — that  is  the  most  im- 
portant thing. 

"There  are  many  other  things 
that  can  be  done,  but  now  Is  not 
the  time  to  go  into  detail.  My 
purpose  here  was  to  throw  out 
some  ideas  for  you  to  consider. 

"We  take  tests;  we  learn 
rules;  we  are  told  that  there  are 
certain  fines  for  violating  the 
law.  We  are  basically  law- 
abiding.  However,  there  is  that 
small  percentage  ol  people  1 
prefer  to  call  mentally 
demented  who  say,  *lf  I  can't 
talk,  then  nobody  wilt  talk,'  or 
who  enjoy  swearing  and  the 
jamming  that  prevents  others 
from    talking.   Those   are   my 


Ideas.  They  will  be  devel- 
oped further.  I  did  not  become 
an  amateur  to  put  up  with  that 
stuff,  and  1  don*t  think  that  I 
should  be  afraid  to  turn  on  my 
radio  in  the  car  when  my  wife 
and  particularly  my  child  is 
there." 

The  above  was  transcribed 
from  a  tape  recording  made  on 
September  23,  1978,  at  the 
ARRL  Southwestern  Division 
convention  in  San  Oiego, 
California.  They  are  the 
statements  of  a  man  who 
cares,  and  very  closely  echo  my 
views.  In  the  near  future,  copies 
of  this  talk  and  others  at  the 
special  sixvhour  seminar  will  be 
made  available  through  the 
seminar  sponsors.  Watch  your 
normal  amateur  media  outlets 
and  this  column  for  further  in- 
formation. Comments  on  Joe's 
ideas  can  be  directed  to  him 
through  this  column.  LW  will 
continue  watch  on  this  topic 
until  the  amateur  service  rids 
itself  of  this  menace  to  its  con- 
tinued existence. 

THE  GROWING  WELL 
DEPARTMENT 

Thanks  to  William  Oliver 
Grieve  W7WGW,  I  have  some 
Interesting  news  concerning 
two  meter  activity  in  Arizona. 
First,  congratulations  to 
W7WGW  on  being  elected  as 
secretary  of  the  Amateur  Radio 
Council  of  Arizona.  We  at  LW 
wish  him  well  in  this  position. 
Oliver  owns  WR7AFC  (147.60/ 
.00)  and  WR7AHJ  (147,87/,27)  in 
the  Phoenix  area. 

Now,  how  many  repeaters 
would  you  imagine  that  a  state 
like  Arizona  plays  host  to  on 
two  meters?  Well,  unless  I  have 
counted  wrong,  the  new  lisl 
shows  53  such  machines,  in- 
cluding the  first  two  inverted 
tertiary  allocations  on 
146.745/.  145  and  146.865/.265. 
Judging  by  this  list,  one  should 
be  able  to  go  just  about  any 
place  in  Arizona  these  days  and 
have   two   meter   communica- 

Continued  on  page  f34 


124 


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125 


Build  a  Realistic  S-Meter 


// 


you're  S9  +  40,  OM! 


// 


Raif  Beyer  DJ3NW 
Opferkamp  14 

33  Braunschweig- Wa^^um 
Germany 


What  is  the  most  fix- 
ating item  in  the 
ham  shack  when  you  have 
tuned  in  a  signal?  The 
S-meter!  Do  you  trust  it? 
Nol 

These  are  hypothetical 
answers  to  these  questions, 
but  chances  are  great  that 
this  would  be  the  response 
If  someone  were  asked  to 
investigate  the  role  of  the 
S-meter  in  many  of  today's 
receivers.  All  of  us  have 
had  our  own  experiences 
with  S-meters,  but  a 
general  trend  can  be 
observed  centering  around 


four  major  problems: 

1.  Many  S-meters  show 
nearly  accurate  readings  in 
the  vicinity  of  the  S9  mark. 

2.  Many  S-meters  indicate 
much  higher  S-values  than 
appropriate  for  signals 
stronger  than  S9. 

3.  Many  S-meters  are  in- 
sensitive to  signals  below 

53  or  S4.  (''I  can  copy  you 

54  though  you  are  not  mov- 
ing the  needle/') 

4.  Many  S-meters  indicate 
much  lower  S-values  than 
appropriate  when  SSB  or 
CW  is  received.  ["Say  aah 
or  press  the  key,  so  I  can 
read  the  meter/') 

Correspondence  with  an 
equipment  manufacturer 
showed  that  he  was  well  in- 
formed about  these  prob- 
lems.   But    experience 


iMPyT 
ii-F  o«  Ar  Of 


ni 

E  er B«WT3  ■  Trttt 

BUFFEW 

AUFUFlEfl 

RECTlFlElt 

FUHCTIOft 

- 

J 

ouTFirr 


iS-«ETEH 


shows  that  manufacturers 
are  reluctant  to  invest  in 
this  field  because  of  in- 
creased cost  and,  more  im- 
portant, because  radio 
amateurs  have  willingly  ac- 
cepted the  S-meters  as  they 
are  and  because  they  have 
no  opportunity  to  check 
the  calibration  in  most 
cases.  A  simple  method  is 
presented  to  solve  the 
aforementioned  problems 
at  moderate  cost.  The 
method  described  is  ap- 
plicable to  both  i-f  or  af 
signal  based  S-meter  cir- 
cuits„  However,  af  signal 
processing  was  chosen  for 
the  sake  of  simplicity.  A 
Heath  SB-301  receiver  was 
used  as  the  test  vehicle. 


The  Basic  Idea 

A  block  diagram  of  the 
suggested  S-meter  circuit  is 
shown  in  Fig.  1.  The  af 
signal  of  the  receiver, 
taken  in  front  of  the  af  gain 
control,  is  the  input  signal 
for  this  circuit.  It  is  routed 
to  a  buffer  to  provide  isola- 
tion from  the  receiver  to 
keep  the  characteristics  of 
the  receiver  unchanged. 
The  signal  is  then  amplified 
to  a  level  which  allows  a 
diode  in  the  rectifier  circuit 
which  follows  to  conduct 
even  during  small  ampli- 
tudes of  the  input  signal  If 
the  rectifier  output  is  con- 
nected to  an  S-meter  and  if 
the  amplifier  has  a  high 
enough  gain  to  produce  a 


TI4^y«  PfiOPQATtOllAL 
OUfTPyT 


ntntr 


OUTFUT 


OUTFtJT 


Fig.  t.  Block  diagram  of  the  S-meter  circuit 


Fig.  2.  Possible  output  waveforms  which  may  be  obtained 
from  a  simple  variable  function  generator  using  a  ramp 
waveform  as  the  input 


126 


reasonable  output  even  for 
a  small  signal  amplitude  in- 
put the  circuit  discussed 
so  far  would  already  be 
adequate  to  cope  with 
S-meter  problem  No.  3  (in- 
adequate sensitivity  for 
weak  signals).  However,  for 
most  receiver  age  charac- 
teristics, the  gain  of  the 
amplifier  would  be  too 
high  now  for  larger  input 
signal  amplitudes.  This 
would  cause  the  S-meter  to 
indicate  a  much  higher 
S-value  than  appropriate, 
presenting  S-meter  prob- 
lem No,  2  (sensitivity  too 
high  for  strong  signals). 

Therefore,  a  so-called 
function  generator  is 
placed  between  the  rec- 
tifier and  the  S-meter.  A 
function  generator  is  a 
device  which  produces  an 
output  signal  that  can  be 
any  function  of  its  input 
signal  For  example,  a 
signal  of  linearly  increas- 
ing  amplitude  (ramp)  at  the 
function  generator  input 
may  be  converted  by  the 
function  generator  to  a 
signal  which  is  propor- 
tional or  increasingly  more 
or  less  than  proportional  to 
the  input  signal  (Fig.  2). 

It  is  obvious  that  prob- 
lem No.  2  can  be  solved  if  a 
function  generator  with  a 
degressive  [increasingly 
less  than  proportional)  in- 
put/output transfer  func- 
tion is  placed  between  the 
rectifier  and  the  S-meter. 
The  selection  of  an  ap- 
propriate transfer  function 
depends,  of  course,  on  the 
transfer  function  between 
the  receiver  antenna  input 
and  the  rectifier  output 
[determined  mainly  by  the 
gain  control  characteris- 
tics of  the  receiver)  and  on 
the  layout  of  the  S-meter 
scale.  Both,  however,  can 
be  matched  to  each  other 
by  the  function  generator 
so  that  signals  at  the 
receiver  antenna  terminal 
which  range,  for  example, 
from  SI  to  S9  -F60  dB  are 
correctly  indicated  by  the 
S-meter, 

With  the  system  described 
so    far,    it    is    possible   to 


oirrCfiEiiTrATOft 


iNPtiT 

fiCVR  A  F 


OUTPUT 


r- 

I     ns 
1  ^J^ 


LJ  ! 

wo  I  / 


BUFFER 


AWPLIFIER 


RECTIf^lER 


fUWCTlUWOtBlfHfllOH 


&3VAC:* 


QROimC 


*l4av&C 


i"  = 


6R0UNC1 


fig.  3.  Schematic  diagram  of  the  S-meter  circuit  and  power  supply.  CR2  is  a  tow  forward- 
bias  germanium  diode,  Siemens  RL32g  or  equivalent  CR3  through  CR6  are  BA  Y18  diodes 
or  equivalent.  Ml  i$a1  mA,  100-Ohm  internal  resistance  unit  U1  is  an  MC1437L  dual  op 

amp  or  equivalent 


obtain  an  accurate  indica- 
tion of  the  signal  strength 
for  static  (key-down)  sig- 
nals. Keyed  or  modulated 
signals,  however,  make  the 
needle  fluctuate  which 
makes  reading  the  meter 
difficult  (problem  No.  4).  A 
large  capacitor  in  the  rec- 
tifier circuit  would  help,  of 
course,  to  make  the  meter 
needle  more  steady.  But 
the  limited  output  power 
of  the  amplifier,  its  output 
impedance,  the  impedance 
of  the  rectifier,  and  the  in- 
ertia of  the  moving  coil  in 
the  S-meter  form  a  low- 
pass  filter  which  prevents 
the  needle  from  reaching 
the  same  position  for 
CW/SSB  reception  as  for  an 
identical  key*down  condi- 
tion. And,  a  large  capacitor 
makes  the  S-meter  similar- 
ly less  responsive  in  the 
other  direction,  too,  be- 
cause the  decay  time  cons- 
tant IS  also  increased.  This 
prevents  the  S-meter  from 
showing  a  quick  dip  when 
comparing  barefoot/linear 
operation  or  when  looking 
for  a  minimum  in  antenna 
radiation  pattern  tests. 

In    order    to    overcome 
this  problem,  some  form  of 


"quickening"  of  the  rec- 
tifier output  signal  or  the 
meter  needle  movement  is 
required.  This  can  be 
achieved  by  feeding  the 
rectifier  output  signal  into 
a  differentiator  whose  out- 
put signal  is  then  fed  back 
to  the  input  of  the 
amplifier  [Fig.  1).  Now,  let 
us  assume  that  a  signal  at 
the  input  of  the  circuit 
shown  in  Fig.  1  produces  a 
positive  signal  at  the  rec- 
tifier output.  Then  an  in- 
creasing amplitude  of  the 
input  signal  produces  a 
positive  slope  of  the  rec- 
tifier output  signal,  too. 
The  differentiator  con- 
nected to  the  rectifier  out- 
put also  produces  a  posi* 
tive  signal  at  its  output 
which  is  proportional  to 
the  slope  of  the  rectifier 
output  signal.  And,  be- 
cause this  signal  is  fed 
back  to  the  input  of  the 
amplifier,  the  differentia- 
tor output  signal  drives  the 
rectifier  output  signal  to  a 
higher  level,  temporarily 
giving  the  rectifier  output 
signal  and  the  meter 
needle  the  desired  ''extra 
punch"  in  the  right  direc- 
tion. 


For  a  decreasing  ampli- 
tude input  signal  in  Fig.  1, 
one  would  expect  a  similar 
effect  which,  however, 
would  drive  the  meter 
needle  in  the  opposite 
direction  because  the  dif- 
ferentiator output  signal  is 
negative  for  a  negative 
slope  of  the  input  signal 
amplitude.  This  would  can- 
cel the  desired  effect  just 
achieved,  so  nothing 
would  be  gained.  But 
because  of  the  fast  at- 
tack/slow decay  character- 
istics of  the  rectifier  cir- 
cuit, a  rising  amplitude  in- 
put signal  produces  a 
positive  and  much  steeper 
slope  of  the  rectifier  out- 
put signal  than  a  drop  of 
the  input  signal  amplitude. 
A  drop  in  signal  amplitude 
produces  a  negative  but 
much  shallower  slope  of 
the  rectifier  output  signal. 
For  a  constant  amplitude 
input  signal  in  Fig.  1,  the 
differentiator  is  inactive, 
of  course,  and  does  not  af- 
fect the  remaining  part  of 
the  circuit. 

The  Circuit 

A  schematic  diagram  of 
the    S-meter    circuit    is 


127 


MUtTiPi^  mempwm^ 


FUNCTION 

APPfiOKlWilTED 
tftANSFEfi   TUNC- 
T(ON 


CM 


Lm 


Fig.  4.  Approximation  of  a  desired  transfer  functior}  by  a 

function  generator  having  a  single  breakpoint.  Fig.  4(al 
and  mukiple  breakpoints.  Fig.  4{bl 


shown  in  Fig.  3.  A  dual 
operational  amplifier  is 
used  for  both  the  buffer 
and  the  amplifier.  Both  am- 
plifiers are  frequency  com- 
pensated by  means  of  CI, 
R3,  C2,  and  C4,  R7,  C5, 
respectively,  as  recom- 
mended in  the  manufac- 
turer's data  sheet.  The  re- 
quired supply  voltage  of 
±15  V  dc  is  provided  by 
two  voltage-doubling  rec- 
tifier circuits  connected  to 
the  63  V  ac  filament  sup- 
ply of  the  receiver. 

The  af  signal  of  the 
receiver,  taken  from  a 
point  preceding  the  vol- 
ume control  potentiome- 
ter, is  connected  to  the  in- 
put terminal  of  the  circuit. 
A  shielded  cable  is  recom- 
mended for  this  connection. 
The  buffer,  U1A,  which 
follows  provides  a  high  in- 
put impedance  to  the 
receiver  so  that  the  af  cir- 
cuit of  the  receiver  is  not 
affected.  The  buffer  out- 
put signal  is  coupled  to  the 
amplifier,  U1B.  The  input  to 
this  amplifier  is  controlled 
by  trimmer  potentiometer 
R4.  This  potentiometer  is 


adjusted  such  that  a  max- 
imum signal  amplitude  of 
S9  +  60  dB  at  the  antenna 
terminal  of  the  receiver 
causes  the  output  ampli* 
tude  of  amplifier  U1B  to 
just  reach  the  limits  of 
linear  operation,  i.e.,  ap- 
proximately ±12  volts.  Of 
course,  potentiometer  R4 
can  be  adjusted  so  that  the 
amplifier  is  driven  into  its 
output  limitation  for  sig- 
nals greater  than  S9  +  40 
dB  or  so  in  order  to  con- 
tribute to  the  desired 
degressive  transfer  behav* 
ior  of  the  S-meter  circuit. 
However,  it  was  not  found 
necessary  in  the  case  of  the 
SB-301  receiver.  The  ampli- 
fied af  signal  is  then  rec- 
tified by  the  rectifier  cir- 
cuit which  follows.  A  ger- 
manium diode  Is  recom- 
mended for  this  circuit. 
The  rectifier  output  is  a  dc 
signal  which  represents  the 
amplitude  of  the  rf  signal 
at  the  antenna  terminal  of 
the  receiver.  The  function 
generator  which  follows 
modifies  this  signal  in 
order  to  match  its  slope  to 
the    graduation    of    the 


TftAWSrEl^  FUNCTION 

OOTAlWED  FOR 
RQ  +R^ ■ 9300a 

RID       <Dn 


tUMfiE  OF 
FUliCTfDiWS 


PD 


e  m  ivj 


fig.  5.  Rangeof  transfer  functions  which  can  be  obtained 
with  the  function  generator  and  the  S-meter  of  Fig.  3, 
Values  of  R10  range  from  zero  to  an  indefinitelY  targe 
value  and  R8  and  R9  adjusted  for  full-scale  output  (1mA) 

at  maximum  input  (10  volt  si 


S-meter  scale. 

The  Function  Generator 

Fig.  3  shows  the  diagram 
of  a  simple  function 
generator  with  one  so- 
called  "breakpoint."  The 
breakpoint  determines  the 
amplitude  of  the  signal  ap- 
plied to  the  generator  in- 
put at  which  the  input/out- 
put transfer  function  of  the 
generator  is  switched  from 
an  initiaf  slope  to  the  final 
slope.  Diode  CR2  in  Fig.  3 
acts  as  the  switch.  For  an 
ideal  switch  with  normally 
open  contacts  and  con- 
tacts closed  when  a  signal 
of  given  amplitude  is  ap- 
plied to  the  function  gener- 
ator input,  the  transfer 
function  which  can  be  ob- 
tained is  shown  as  a  broken 
line  in  Fig,  4{a).  For  a  given 
impedance  of  the  S-meter, 
the  generator  transfer  func- 
tion would  be  controlled  by 
R8  and  R9  (Fig.  3)  alone  up 
to  the  breakpoint  But,  when 
the  breakpoint  is  reached, 
the  switch  is  closed  and 
RIO  is  effective.  The 
amplitude  of  the  generator 
output  signal  is  immediate- 
ly reduced  to  a  lower  level 
[which  is  not  desired),  but 
the  steepness  of  the  slope 
of  the  resulting  transfer 
function  is  also  reduced, 
which  gives  a  first-order  ap* 
proximation  of  the  desired 
transfer  function  as  shown 
in  Fig  4(a)  For  a  closer  ap* 
proximation  of  the  desired 
transfer  function,  more 
breakpoints  (switches)  are 
required  as  shown  m  Fig. 
4(b).  However,  as  the  diode 
CR2  in  Fig.  3  is  not  an  ideal 
switch,  and  because  it 
becomes  only  gradually 
conductive,  the  diode  char- 
acteristic can  be  used  to 
advantage,  thereby  elimi- 
nating the  need  for  multi- 
ple discrete  breakpoints. 

Fig.  5  presents  the  range 
of  calculated  transfer  func- 
tions which  can  be  ob- 
tained with  the  function 
generator  shown  in  Fig.  3, 
The  slope  of  the  transfer 
function  depends  on  the 
characteristics    of   diode 


CR2,  of  course.  The  diode 
shown  in  Fig.  3  was  taken 
from  the  )unk  box,  but 
comparable  results  can  be 
obtained  with  other  ger- 
manium-type diodes  which 
have  a  low  forward  bias  of 
Ud  =  200  mV  at  Ip  -  02 
mA  and  Up  -  350  mV  at 
Id  =  1  mA, 

The  Differentiator 

"Quickening"  of  the 
S-meter    is    achieved    by 

feeding  back  the  output  of 
the  twofold  differentiator 
shown  in  Fig.  3  to  the  input 
of  the  amplifier.  The  out- 
put can  be  adjusted  by 
means  of  R12.  This  type  of 
adjustment  was  found  to 
be  more  convenient  than 
changing  capacitors  C7  or 
C8.  Furthermore,  the  ter- 
minating resistor,  R11,  at 
the  non-inverting  input  of 
amplifier  U1B  was  kept 
constant  by  this  method  in 
order  to  avoid  ill  effects  on 
the  remaining  circuit. 

As  an  ordinary  S-meter 
indicates  the  average  cur- 
rent flowing  through  the 
meter  with  respect  to  time, 
the  amount  of  "quicken- 
ing" is  determined  by  the 
average  amplitude  of  the 
differentiator  output  sig- 
nal. The  average  amplitude 
of  a  signal,  however,  is 
determined  by  its  average 
deviation  from  zero.  Posi- 
tive deviations  are  counted 
positive  and  negative  devi- 
ations are  counted  nega- 
tive. Fig.  6  presents  two 
computed  output  func- 
tions of  the  differentiator 
shown  in  Fig.  3  obtained  for 
identical  inputs  and  dif- 
ferent values  of  R12.  It  can 
be  seen  that  a  large  value 
of  R12  increases  the  (posi- 
tive) average  amplitude  of 
the  differentiator  output 
signal  and  thereby  the 
amount  of  "quickening." 
Optimum  "quickening"  is 
determined  by  a  number  of 
factors  such  as  the  time 
constants  of  the  rectifier 
circuit,  the  damping  of  the 
S-meter,  and  so  on.  A  value 
of  100k  Ohms  for  R12  was 
found  to  be  optimum  when 


128 


Wow! 
A  Good  Portable  Receiver! 


thanks,  Panasonic! 


Photo  by  Robert  Hinman  WA2DIZ 


Joseph  W.  Long  WA2EJT 
Chenmtry  Dept. 
Broome  Commumiy  Coiiege 
Bingham  f on  NY  13902 


The  Panasonic  RF-2200 
is  a  unique  myltiband 
receiver  and  should  be  of 
great  interest  to  manv 
amateurs.  The  receiver 
tunes  standard  broadcast 
AM  and  FM  and  is  general 
coverage  rn  the  shortwave 
spectrum  from  3,9  to  28 
MHz  (more  about  the 
shortwave  frequency  limits 
later  on). 

There  are  several  items 
which  make  this  receiver  of 
so  much  potential  interest. 
The  first  concerns  the 
shortwave  section.  The 
coverage  is  in  6  bands, 
each  4  MHz  wide,  which 
are  tuned  with  a  linear  dial 
scale  calibrated  every  10 
kHz  and  which  can  be  read 
to    within    about    3    kHz 


throughout  the  whole 
shortwave  spectrum. 

There  are  two  built-in 
crystal  calibrators,  one  at 
0.5  MHz  and  one  at  0.125 
MHz,  with  which  the  dial 
may  be  very  accurately 
calibrated.  When  cali- 
brated at  the  appropriate 
spot,  any  frequency 
throughout  its  range  may 
be  dialed  up  with  the 
volume  off.  Turning  up  the 
receiver  volume  will  bring 
in  the  station  if  it  can  be 
heard.  Shades  of  the 
R-390/51  I  Collins  general- 
coverage  receiversi 

The  vfo  tunes  over  4 
MHz,  but,  even  with  this 
range,  the  dial  is  surprising- 
ly  linear.  For  example,  my 
RF-2200  on  band  SW  3 
(12-16  MHz),  when  cali^ 
bra  ted  at  12  MHz,  has  a 
dial  error  of  no  more  than 
10  kHz  all  the  way  up  to 
15.5  MHz.  The  16.0  MHz 
point  is  off  by  about  20 
kHz, 


Turning  on  the  cali- 
brators automatically 
disconnects  the  antenna, 
turns  on  the  bfo,  and 
declutches  the  linear  dial 
so  that  there  are  no  points 
to  offset.  That's  just  about 
like  it's  done  in  my  Collins 
R-391. 

The  receiver  also  has  an 
excellent  product  detector 
tuning  meter  and  rf  gain 
control,  making  it  great  for 
use  within  the  ham  bands. 
Also  useful  are  a  wide/nar- 
row i-f  selectivity  switch 
(narrow  is  not  very  narrow), 
separate  bass  and  treble 
controls,  and  a  Ewo-speed 
dial. 

The  SW  section  of  the 
RF  2200  is  very  hot  and  the 
built-in  whip  antenna 
brings  in  all  manner  of 
signals.  The  receiver  is 
advertised  as  tunable  from 
3.9  to  28  MHz,  but  mine  ac* 
tually  goes  all  the  way 
down  to  3.5  MHz,  with  the 
dial       getting       rather 


nonlinear.  It  also  tunes 
above  28  MHz  — to  just 
above  28,5  MHz. 

For  $140,  you  don't  get 
everything,  of  course,  and 
the  receiver  does  have 
some  deficiencies  which 
must  be  mentioned.  First 
there  is  a  slow  drift  during 
reception  of  CW  and  SSB 
signals  which  is  indepen- 
dent of  frequency-  The  in- 
struction manual  suggests 
that  the  bfo  be  turned  on  5 
minutes  early  for  "won- 
derful CW  and  SSB  re* 
ception.''  This  suggestion  is 
helpful,  but  there  remains 
a  slow  drift  even  after  long 
periods.  Since  the  problem 
does  appear  to  be  caused 
by  drift  in  the  bfo  circuit  ' 
suspect  that  it  could  be 
cured  fairly  easily. 

Another  deficiency  is  a 
dead  space  in  the  tuning 
gears.  This  is  only  dead 
space;  the  signals  do  not 
keep  going  the  wrong  way 
when    you    reverse    direc- 


130 


the  circuit  was  installed  in 
a  Heath  S 6-301  receiver. 
Compared  to  the  indica- 
tion of  the  S-meter  for  a 
key-down  signal  from  a 
transmitter,  this  value  of 
R12  produced  an  almost 
identical  indication  on  the 
meter  when  SSB  (processed 
and  unprocessed  speech) 
was  used  and  only  ^  slight- 
ly higher  one  for  CW. 

Construction 

The  circuit  shown  in  Fig. 
3  was  bui[t  on  a  65mm  X 
65mm  (2Vi-inch  x 
2  Va-inch)  Vector  board. 
Helitrim'^  potentiometers 
were  used  for  all  poten- 
tiometers because  they  are 
small  and  convenient  to 
adjust.  All  other  com- 
ponents are  miniature  size 
A  socket  was  used  for  U1. 
The  board  has  four  ter- 
minals: ground,  6.3  V  ac, 
receiver  af,  and  S-meter. 
The  board  was  mounted  at 
the  back  of  the  front  panel 
of  the  SB-301  receiver  by 
means  of  a  mounting 
bracket  held  by  the  screw 
in  the  upper  right-hand  cor- 
ner of  the  panel.  A  shielded 
cable  was  used  for  the  con- 
nection between  the  "hot" 
end  of  the  receiver  af  gain 
control  and  the  input  ter- 
minal of  the  circuit* 

Alignment 

A  signal  generator  and 
an  attenuator  are  required 
which  can  provide  an  un- 
modulated signal  on  all 
bands  of  interest  within  the 
range  of  S1  through  S9 
+  60  dB.  A  signal  ampli- 
tude of  50  microvolts  at 
the  50  Ohm  antenna  ter- 
minal may  be  used  for  S9 
and  half  the  amplitude 
(  —  6  dB)  of  the  preceding 
S-value  for  the  next  lower 
S-value,  i.e.,  25  microvolts 
for  58  and  so  on  [1  dB  =  20 
'  log(Vout/Vin)  for  the  at- 
tenuator]. Some  signal 
generators  are  calibrated 
to  produce  a  signal  of 
given  amplitude  if  the 
generator  output  is  unter- 
minated  (open)  Others  are 
calibrated  for  an  output 
terminated  with  50  Ohms* 


One  should  be  sure  which 
type  of  generator  is  on 
hand  before  the  alignment 
is  started. 

First,  the  receiver  should 
be  checked  to  be  in  good 
condition  and  for  uniform 
gain  on  all  bands  of  in- 
terest. With  the  rf  gain  con- 
trol  set  to  maximum  gain, 
age  on,  mode  switch  set  to 
USB,  LSB,  or  CW,  and  the 
receiver  tuned  for  max- 
imum input  to  the  S-meter 
circuit  each  band  should 
be  checked  to  note  what 
signal  amplitude  at  the 
antenna  terminal  of  the 
receiver  produces  a  given 
beat  note  amplitude  at  the 
af  input  of  the  S-meter  cir- 
cuit. For  the  SB-301,  iden- 
tical beat  note  amplitudes 
were  obtained  on  all  bands 
with  an  input  signal  varia- 
tion of  less  than  ±1  dB 
(±1/6S-unit). 

Next,  the  receiver  should 
be  checked  for  uniform 
gain  in  all  modes.  It  was 
noted,  for  example,  that 
for  a  constant  signal 
amplitude  at  the  antenna 
terminal  of  the  SB-301,  a 
somewhat  higher  beat  note 
amplitude  was  obtained 
when  the  receiver  was 
switched  from  LSB  to  USB. 
The  reason  for  this  was  a 
higher  signal  amplitude  of 
the  bfo  crystal  used  in  the 
USB  mode.  A  potentiome- 
ter across  the  terminals  of 
this  crystal  was  used  to 
reduce  the  bfo  output 
amplitude  in  this  mode  so 
that  a  uniform  receiver 
gain  was  obtained  for  both 
USB  and  LSB  modes.  No 
separate  CW  filter  was  in- 
stalled in  the  SB  301  which 
may  have  a  passband  at- 
tenuation different  from 
the  SSB  filter.  And  because 
the  USB  crystal  is  also  used 
for  CW  in  the  SB-301,  an 
identical  receiver  gain  was 
obtained  in  the  CW  mode, 
too. 

Next,  the  function  gener- 
ator is  aligned.  This  should 
be  done  on  a  band  on 
which  the  receiver  has  an 
average  gain  compared  to 
all  other  bands.  Three 
parameters  of  the  function 


COUTIVI 


1000 


TIME  r^i 


Fig.  6,  Calculated  response  of  the  differentiator  in  Fig,  3  to 
a  I'volt  positive-going  pulse  using  different  values  of  R12. 


generator  transfer  function 
can  be  adjusted  within 
given  limits  (see  Fig,  5):  the 
initial  slope  (primarily  con- 
trolled by  the  sum  of  R& 
and  R9J,  the  input  voltage 
at  which  the  breakpoint  oc- 
curs [prtmahly  controlled 
by  the  ratio  of  R8  to  R9), 
and  the  final  slope 
(primarily  controlled  by 
RIO).  It  is  generally  possi- 
ble, therefore,  to  adjust  the 
transfer  function  of  the 
generator  so  that  it  passes 
through  one  given  point  of 
the  desired  transfer  func- 
tion left  of  the  breakpoint 
and  through  two  other 
given  points  right  of  the 
breakpoint.  At  other 
points,  there  may  be  a 
deviation  of  the  transfer 
function  which  can  be  im- 
plemented from  the  de- 
sired one.  But  the  trick  is  to 
find  those  three  reference 
points  of  the  desired 
transfer  function  to  which 
the  function  generator  can 
be  adjusted  almost  per- 
fectly, while  the  average 
deviation  at  all  other 
points  is  reduced  to  a 
minimum.  For  the  SB-301, 
such  points  were  found  at 
55  (left  of  the  breakpoint] 
and  S9  and  S9  +  40  dB 
(both  right  of  the  break- 
point) By  an  iterative  pro- 
cess, R8,  R9,  and  RIO  were 
adjusted  so  that  for  ap- 
propriate signals  at  the 
antenna  terminal  of  the  re- 
ceiver, the  S-meter  showed 
accurate  S-readings  at 
these  points  and  a  max- 
imum deviation  of  about 
±2  dB  (±1/3  S-unit)at  all 
other  points.  The  average 


deviation  was  less  than 
that  and  negligible  for 
signals  below  S9  +  10  dB. 

Conclusions 

fn  1969,  the  S-meter  cir- 
cuit was  installed  in  a 
SB-301  receiver  and  has  pro- 
vided stable  operation  since 
then.  No  realignment  has 
been  necessary  so  far,  but 
annual  checks  of  the  receiv- 
er are  recommended.  It  is 
helpful,  therefore,  to  keep 
a  record  of  the  S-meter 
readings  which  can  be  ob* 
tained  with  the  internal 
crystal  calibrator  of  the 
receiver  on  all  bands.  Any 
deviation  from  these  val- 
ues which  may  occur  later 
indicates  that  the  perfor- 
mance of  the  receiver,  the 
S-meter  circuit,  or  the 
calibrator  is  degraded  and 
that  there  is  something  to 
be  done. 

The  S-meter  problems 
listed  in  the  introduction 
were  solved  satisfactorily 
and  the  S-meter  reports 
became  more  meaningful 
and  objective.  This  is  par- 
ticularly useful  for  relative 
reports,  e.g.,  a  comparison 
of  barefoot/linear  opera- 
tion or  antenna  checks.  Ab- 
solute reports  may  be  ac- 
companied by  a  short 
statement  on  the  antenna 
used,  on  topographical  pe- 
culiarities, and  on  the  ac- 
curacy of  the  S-meter.  But 
simply  spoken,  it  is  a  real 
pleasure  to  give  that  low* 
power  or  faraway  station  a 
better  and  accurate  report 
and  not  to  fool  others  with 
unrealistic  S9  +  20  dB 
reports.  ■ 


129 


tions;  they  just  don't 
change  at  all.  The  effect  is 
noticeable  only  on  CW  and 
SSB.  Even  at  low  speed,  the 
tuning  is  a  bit  fast  for  CW 
and  SSB  — a  very  delicate 
touch  is  required.  Other- 
wise,  the  feel  of  the  tuning 
is  really  excellent  and 
smacks  of  quality. 

In  the  higher  SW  bands, 
the  rf  gain  control  pulls  the 
signals  quite  a  bit.  I  actual- 
ly rather  like  this  deficien- 
cy, as  it  can  be  used  as  a 
fine  tuning  control 

A  fourth  problem  is  the 
presence  of  an  unusual 
kind  of  spurious  signal 
When  very  strong  CB 
signals  are  tuned  in  on 
band  6  [24-28  MHz),  they 
can  still  be  heard  on  band  5 
(20-24  MHz)  at  the  same 
points  on  the  dial  It 
sounds  as  though  there  is 
some  sort  of  leakage  in  the 
hfo  chain  in  the  front  end. 
This  does  not  seem  to  be  a 
serious  problem;  the  only 
place  I  have  noticed  it  is 
with  very  strong  CB  signals. 

A  test  which  it  occurred 
to  me  to  make  just  as  I 
write  this  is  for  mechani- 
cal stability.  A  good  rap  on 
the  side  of  the  set,  or  a  two- 
inch  C5.08  cm)  drop  test  will 
not  throw  the  receiver  off 
from  zero  beat.  Amazing! 

There  are  many  com- 
ments which  are  important 
regarding  the  AM  and  FM 
bands  on  the  receiver.  The 
AM  reception  is  excellent. 
It  is  extremely  sensitive, 
and  it  seems  much  less  sus- 
ceptible to  noise  pickup 
than  most  other  receivers. 
For  example,  in  my  office 
at  work  I  can  regularly 
receive  WQXR  from  New 
York  City  (over  100  miles 
awayX  while  other  radios 
from  the  same  spot  can 
barely  get  the  local 
Bingham  ton  stations 
through  all  of  the  fluores- 
cent light  noises.  This  noise 
immunity  really  amazes 
me;  I  wish  I  could  explain 
it. 

The  dial  is  calibrated 
every  20  kHz  on  the  BC 
band  and  is  quite  accurate; 
the  greatest  error  on  my 


•^ 


2200  is  about  10  kHz 
around  the  middle  of  the 
band.  This  is  infinitely  bet- 
ter than  the  calibration  on 
most  other  transistor 
radios  I've  seen. 

The  AM  antenna  may  be 
swiveled.  It's  on  the  top  of 
the  radio,  is  calibrated  in 
degrees,  and  may  be  used 
for  amateur  direction-find- 
ing. When  I've  tried  it,  all  I 
was  able  to  prove  was  that 
Binghamton,  New  York,  is 
somewhere  in  the  middle 
of  the  Atlantic. 

I  have  saved  one  of  the 
nicest  sections  of  the  re- 
ceiver  for  last:  the  FM 
band.  FM  on  this  set  is  truly 
outstanding.  It  is  about  the 
hottest  FM  receiver  Tve 
ever  heard;  it  outshines  my 
$700  Mcintosh  FM  tuner  in 
this  regard.  One  evening, 
my  girl  friend  and  I  logged 
stations  from  Syracuse^ 
Utica,  Scranton,  and 
Wilkes  Barre  on  the  built-in 
whip  antenna  from  a  lo- 
cation where  other  port- 
ables can  hear  the  local 
stations  and  nothing  more. 
The  2200  has  very  few 
spurious  responses  on  FM, 
many  fewer  than  I  have 
ever  seen  on  any  other  FM 
portables. 

The  FM  selectivity  is 
also  outstanding.  Bing- 
hamton  is  blessed  with  two 


very  powerful  stations  on 
98.1  and  99.1  MHz,  yet 
WBRE  in  Wilkes  Barre,  on 
98.5  MHz  (about  70  moun- 
tainous air  miles  away  and 
very  weak),  can  be  tuned  in 
easily.  FM  dial  readings 
may  be  estimated  quite  ac- 
curately, using  the  built-in 
logging  scale,  to  about 
plus/minus  03  MHz, 

The  audio  in  the  set  is  of 
first  quality.  The  receiver 
produces  several  Watts  of 
very  clean  sound.  Every- 
one who  has  heard  it 
agrees  that  it  sounds  unbe- 
lievably good.  This  high- 
quality  audio  is,  of  course, 
somewhat  wasted  on  the 
AM  and  SW  bands. 

The  receiver  will  play  on 
internal  batteries  (4  D  cells, 
included)  or  on  110  volts 
by  plugging  in  the  line 
cord.  Battery  life  is  very 
long. 

The  packaging  of  the  ra- 
dio is  very  nice.  It  has  an  at- 
tractive but  rugged  pi  as* 
tic  case,  the  controls  are 
well  and  plainly  marked, 
and  a  momentary-on  dial 
light  is  included  for  night- 
time spy  radio  listening  I 
understand  that  an  exten- 
sive service  manual  is 
available  for  $3.50,  which 
can  be  obtained  from  Pan- 
asonic service  centers. 

I  became  hooked  on  the 


set  when  I  got  to  play  with 
one  my  baby  brother  had 
purchased  and  was  raving 
about.  After  fiddling  with 
my  2200  [when  they  should 
have  been  working),  two  of 
my  co-workers  rushed  out 
to  buy  their  own  and  a 
third  is  thinking  of  how  he 
might  slip  one  past  his 
wife.  The  2200  disease  is 
very  contagious! 

The  set  should  be  avail- 
able from  dealers  well 
stocked  in  Panasonic  gear. 
The  prices  seem  to  range 
from  about  S117  at  47th 
Street  Photo  in  NYC  [which 
ts  usually  out  of  stock)  to 
$138,  which  I  paid  at  a  dis- 
count store  here  in  Bing- 
hamton. 

This  little  box  is  a  real 
jewel  It  is  unique  in  the 
high  quality  of  all  three  of 
its  bands.  Its  "new  tech- 
nology" SW  circuitry  and 
tremendous  audio  make  it 
a  set  that  any  receiver  buff, 
as  welt  as  many  others,  will 
want  to  own. 

I  would  like  to  etn- 
phasize  that  I  have  noth- 
ing to  do  with  the  Pana- 
sonic company  (I  wish  1 
did!)  and  that  this  article  is 
unsolicited.  The  article  is 
just  an  attempt  to  provide 
an  honest  report  on  a  nice 
piece  of  gear  to  people 
who  may  be  interested.  ■ 


131 


Willmm  P.  PiykrAH6AQ 
IS02-A  Tinker  Ave. 
Honolulu  HI  96818 


The  XITEX  Video  Terminal 


a  quiet  alternative 
to  your  Model  15 


I  have  been  in  RTTY  for 
about  two  years  and 
have  decided  to  do 
something  about  all  the 
noise  in  the  shack  caused 
by  the  Model  15  printer.  I 
visited  a  fellow  ham  and 
looked  at  his  video  ter- 
minal and  knew  at  once 
that  video  was  the  course 
to  follow. 

We  Air  Force  types  are 
not  what  you  would  call 
"rolling  in  the  money,"  so  I 
looked  for  some  type  of  kit 
to  assemble.  I  took  my 
search  to  the  usual  month- 
ly publications,  but  this 
proved  to  be  in  vain,  as 
everything  appeared  to  be 
encoded  in  ASCII  and  we 
hams  must  transmit  in 
Baudot.  As  my  search  pro- 
ceeded, I  still  wasn't  hav- 
ing very  much  luck,  until, 
one  day,  I  spotted  an 
advertisement  in  73. 
Reading  further,  I  was  im- 
pressed  with  the  fact  that 
this  video  terminal  would 
interface  in  ASCII  and 
Baudot,    This    video    ter- 

132 


minal  is  the  SCT-100,  by 
XITEX,  P.O.  Box  20887, 
Dallas,  Texas  75220. 

Not  only  does  this  5''  by 
10''  board  speak  both 
ASCII  and  Baudot,  but  also 
t  won't  have  to  hock  my 
ham  gear  to  be  able  to  af- 
ford  it.  Now  whenever  the 
FCC  decides  to  let  hams 
use  ASCII,  or  1  figure  out 
what  computers  do,  I  will 
be  ready. 

This  video  board  has  the 
capability  for  serial  ASCII 
or  Baudot,  full  X-Y  cursor 
control,  128  characters  in- 
cluding upper  and  lower 
case,  16  lines  by  64 
characters,  S-100  com- 
patibility, and  operates  on 
7  V  dc  unregulated  or  12.5 
V  ac  at  one  Amp.  The 
SCT-100  single-card  ter- 
minal interfaces  directly  to 
any  computer  or  modem 
having  serial  ASCII  or 
Baudot  capability.  It  re- 
quires only  the  addition  of 
an  ASCII  keyboard  and  a 
TV  monitor  or  modified  TV 


set.  It's  available  in  two  kit 
forms  or  prewired  and 
tested. 

Well,  1  have  to  admit 
that  all  this  looked  good  to 
me,  but  t  am  just  a  ham 
and  I  don't  know  much 
about  computers,  key- 
boards, etc.  This  was 
solved,  however,  by  a  call 
to  the  factory.  After  talking 
to  them  a  bit  and  asking  a 
few  very  elementary  ques- 
tions, 1  ordered  a  prewired 
and  tested  unit,  and  now, 
at  last,  I  am  on  the  way  to 
ridding  myself  of  a  lot  of 
noise.  I  ordered  a  keyboard 
kit  from  a  parts  distributer, 
so  now  1  am  into  this  thing 
wholeheartedly. 

As  fate  would  have  it, 
the  keyboard  arrived  first, 
so,  at  once,  I  went  off  to 
my  local  parts  supplier, 
purchased  two  chassis,  and 
picked  up  a  copy  of  the 
TVT  Cookbook.  I  would 
definitely  recommend  this 
little  book  to  anyone  at- 
tempting any  video  ter- 
minal project.  Now,  I  sup- 


pose one  can  put  the 
keyboard  and  the  terminal 
board  in  the  same  chassis; 
however,  1  often  like  to  do 
things  the  hard  way. 

The  keyboard  was  a 
cinch  to  assemble,  only 
taking  about  one  hour.  I 
checked  it  out  and  it  per- 
formed okay.  The  messy 
part  is  cutting  the  chassis 
and  causing  small  bits  of 
metal  to  fly  all  over  the 
shack.  I  performed  a  few 
measurements,  cut  the 
hole  in  the  keyboard 
chassis,  and  installed  the 
keyboard.  It  looked  okay 
except  for  all  the  scratches 
that  were  added  to  the  out- 
side of  the  chassis.  So 
out  the  door  1  went  to  the 
local  hardware  store  for 
some  contact  paper  to  give 
the  whole  thing  that 
''wood-grain  look."  After 
applying  this  to  the  chassis, 
it  looked  a  lot  better.  I  also 
installed  wooden  wedges 
to  give  the  keyboard  the 
proper  angle  for  ease  in 
typing  ...  I  don't  think  this 


video 
on    a 

until 


Step  wifl  improve  my  typ- 
ing, but  it  looks  better. 

Next,  I  moved  to  the 
chassis  that  would  house 
the  video  terminal  board.  I 
installed  a  12.5  V  ac 
transformer  and  a  5-Ohm 
resistor  to  supply  approx- 
imately 8  V  ac  to  the  on- 
board supply.  The  SCT-100 
has  a  5  V  dc  regulated  one- 
Amp  power  supply  on 
board,  and  this  is  enough 
to  power  the  video  board 
and  the  keyboard.  How- 
ever, if  your  keyboard  re- 
quires  -12  V  dc,  you  will 
need  to  add  a  -1 2  V  dc  sup- 
ply. I  must  point  out  that 
the  parts  are  not  critical 
and  most  can  be  obtained 
from  the  average  junk  box. 

The  next  move  was  to 
tiptoe  upstairs  and  kidnap 
my  daughter's  12"  TV  for 
modification  to  a  video 
monitor.  This  TV 
monitor  was  used 
time-share  basis 
Christmas  when  we  pur- 
chased another  one  for  her. 
I  used  the  guidelines  from 
the  TVT  Cookbook  to 
modify  the  TV.  My  only 
catch  was  that  the  TV 
turned  out  to  be  a  hot 
chassis  set.  This  problem 
was  solved  by  using  two 
old  TV  transformers  and  ty- 
ing their  6.3  leads  together 
to  make  an  "el  cheapo" 
isolation  transformer. 

At  last  the  UPS  package 
arrived,  and  it  was  time  for 
the  task  of  tying  all  the 
components  together*  First 
you  should  read  al[  the  in- 
structions; then  the  same 
instructions  should  be  read 
again  and  again,  I  know  the 
first  thing  one  usually  does 
is  to  cast  aside  the  instruc- 
tions and  proceed  full 
speed  ahead.  This  may  be 
okay  for  some  people,  but 
not  me.  As  I  have  said 
before,  I  often  do  things 
the  hard  way. 

Now  that  the  instruc- 
tions  seemed  clear,  I  made 
all  the  connections  that 
would  be  required.  1 
planned  for  the  future  and 
made  the  provisions  for 
RS'232  and  a  60  mA  loop. 
There  is  one  point  here  that 


I  would  like  to  bring  up. 
There  are  some  voltage 
points  called  E3,  4,  and  5. 
These  are  used  to  connect 
either  an  external  5  V  dc 
supply  or  approximately  7 
V  dc  to  the  on-board 
regulator,  or  to  strap  the 
on-board  supply  to  the  cir- 
cuit. This  is  not  clear  in  the 
instruction,  and  one  can 
look    at    the    diagram    to 


make  the  connections- 

Now  for  the  moment  of 
truth,  I  hooked  up  the 
video  monitor  and 
powered  up.  This  produced 
a  screen  full  of  garble,  so  I 
cycled  the  power  switch 
and  the  screen  cleared  up 
and  the  cursor  moved  to 
home.  The  instructions 
make  clear  that  if  clearing 
is  encountered,  a  capacitor 


change  is  in  order. 

Next  I  jumpered  the 
RS-232  in/out  ports 
together  and  plugged  the 
keyboard  in  for  keyboard 
checkout,  first  checking  all 
the  key  functions  in  ASCII 
and  then  proceeding  with 
the  Baudot  checkout.  The 
Baudot  mode  had  no  let- 
ters. After  reading  all  the 
directions,   I   strapped   my 


133 


keyboard    for    upper   case      and    discussed    this    situa-          I  next  turned  on  the  rig.      Bob    Farrier    for    all    their 
only  and  the  Baudot  func-      tipn   with   John    McC radv. ^.called  CO.  and  had  mvfir^it      ^s<iistanrp 


The  parjujieters  of  tJ|§  Palomar  PTR-130k  are 


the  ouier  perime 


n  ]  I  m  n  In  iiHiA  I  ui 


iiiniiiiiiiH 


[■1^11 


/alnnim  PTR  130k! 

\l'^  \}w  first  uimpletiily  nuil 
firnctjdniil  tia(iscitiv(*r  t^vm  mad*? 
<ivj|jfiblr^  to  IfK!  (HI bite* 

Thtr  Piiloninr  PTR- 130k    is  ii 
miniaturizftd  ni<>l)il(;  iriinsctjivcr 


Ci»ptil)le  uf  a|>(!r^iliiuj  in  100  cycU; 
n*!^oliilion  from    100  KM/  k) 
30  Mf!/  in  iill  n1(K^^??;uf 
h. ins  miss  I  on  und  nicupuon. 
Iiisiant  fiequiincy  selection  is 
available  with  tfie  touch  of 
a  finger. 

The  Palomar  PTR -130k. 


Krchnulotjv  is  pun?  ^uivai  acjo  ,  .  . 
Ih*j  pricf?  is  strictly  down  to  (jarth 
Sentl  for  our  lull  color 
brochure  to: 

Palomar  Electronics  Corporation 
665  Opper  Street 
Escondido,  CA  92025 
Telephone;  (714}  746-2666 


i  y^. 


'^/Oifjl 


Sjh 


^AJjQ 


jsb- 


f*Tfi. 


'3QK 


»»U 


^t^Q 


AM 


CW  LSB 


^''fiOUf 


/    ^a 


Ncy 


LC 


m 


T  t  L  H  N  O  L  O  G  Y    A  I    T  H  1     bPl  F  P    ^^  \ 


U  P 


imnjiinniiln 


Fig.  2.  PC  board. 


connector  or  to  the 
readout  if  desired.  There  is 
a  total  of  16  wires  used,  so 
a  15"pin  connector  can  be 
used    if   the   ground    wire 


to  easily  mount  the  board 
artd  readouts  inside  with 
room  to  spare. 

1  hope  this  article  will  be 
of  help  to  the  many  hams 


Fig.  3.  Component  layout  [fait  side  view].  Strap  ground 
wire  with  24  gauge. 


turn  on  the  inside  light  of 
the  vehicle.  I  hope  that  no 
one  thinks  that  I  stole  their 
idea;  it  was  not  intended,  1 


mention:  You  can  also  use 
an  external  5-voIt  regulator 
instead  of  the  5  volts  from 
the  radio;  however,  in  my 


MADISON 

ELECTRONICS  SUPPLY,  INC. 


1S08-B  McKINNEY 
71 3/658-0268 


HOUSTON,  TEXAS  77002 
Nites  713/497-5683 


NEW!  EXCITING!  BREAKTHROUGH! 

YAESU         FRG-7000 
Shortwave  Receiver 


$655.00 

The 

Shortwave  Receiver 
Since  the  HRO! 

(Call  for  Quotes) 


ANTENNAS 

Model  OJA-146 

TWO  METER  AMATEUR  BAND  146^148MHi 

•  NO  GROUND  PLANE  REQUIRED 

-  USE  FIXED.  MOBILE,  OR  PORTABLE 

-  &de  GAIN  OVER  iSOTROPIC  IN  MOST  MOBILE 
APPLICATIONS 

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•  STEEL  WHIP  AND  ADAPTER  INCLUDED  FOR  MOBILE  AND 
FIXED  APPLICATIONS 

•  VSWR:  LESS  THAN  1.2:1 

PRICE  $39.95  UPS  Prepaid 

220  MHz  — $37.95  450  MHz  —  $37.95 


CALL  FOR  FAST  QUOTES 
SPECIAL  ORDERS  WELCOME 


TERMS;  All  pnces  FOB  Houslon,  Prices  subieci  Eo  c^^ange  without  noiice. 
All  iieiTiS  GuaraiMeed-  Some  ilems  subject  to  prior  sale  Send  ketiefhead  for 
Amateur  dealers  price  list.  Texas  re&Jdenls  add  6%  tax.  Please  add 
postage  eshmaie 


W5GJ.  W5MBB.  K5AA0.  N5JJ.  W5IMJ.  AG5K.  WDSEOE.  K5ZD.  WD5ABFI. 
WA5TGU.  WD5B0X,  WB5AYF,  K5RC,  KSBGB- 

Have  A  Ntce  Day! 

DLA. 


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Tonna  F9FT  Antennas  144/i6eJ , S79.95 

RIW  432/l9el $59.95 

KLITZING  VHF'UHF  Amplifiers 

2M  10W  In  —  lOOWOUt $190.00 

432  10W  In  —  50  W  Out .:. S198.00 

BIRD  43  &  Slugs.  Stock,  UPS  Paid Call 

Microwave  Modules  432  2es.  UPS  Paid S29S.00 

Tetrex  T85EM.  In  Stock $415,00 

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Technical  books:  AM  ECO,  ARRL  Sams.  TAB.  Rider. 

Radio  Pub.,  Caiibook.  Cowan  many  others Call 

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Consolidated  HD-16  Ga.  Galv.  Tower.  10"  Sec. $29.95 

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MADISON  .». 

ELECTRONICS  SUPPLY,  INC. 


1508-BMcKrNNEY 
713/658-0268 


HOUSTON,  TEXAS  77002 
Nttes  713/497-5683 


BHinN 


p^  Heatfer  Sen/ Ice— ^ee  page  323. 


139 


PO/iEfl 


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140 


p^  Pteadef  Service—  see  page  323. 


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High  Seas  Adventure 

Ham  Style 


part  III 


ntotos  by  Jules  Wenglare  W6YO 


James E.  Seidel  WA6FEf 
1066 N.  WestsideSL 
Porterville  CA  93257 


i  i  #^  ommercial    broad- 

^^  cast  stations  and  40 
meter  harmonics  literaHy 
dominated  the  20  meter 
band.  No  stateside  signals 
were  heard  for  several 
days,  Very  little  was  heard 
from  anywhere." 

That  was  the  comment 
Jules  Wenglare  W6YO 
made  about  his  amateur 
radio  activities  in  the  South 
China  Sea  during  his  10-. 
month  around-the-world 
cruise.  He  had  set  sail  from 
Freeport  in  the  Bahamas 
five  months  earlier  aboard 
the  Yankee  Trader.  In  a  few 
days  the  ship  would  stop  at 
still  another  exotic  port: 
Singapore. 

The  Trader  docked  in 
Singapore  on  July  18, 1977. 
^'There  were  countless 
numbers  of  ships  in  the 
bay/'  said  Jutes,  "making  it 
very  difficult  to  get  dock 
space.  The  city  looked  very 
beautiful  from  the  water- 
front." 

After  customs  clear- 
ance, the  passengers  were 
allowed  to  go  ashore.  Jules 
contacted   Doctor  Charan 


9V1NR  at  his  dispensary, 
and  later  went  to  his  home. 
While  there,  he  had  a 
chance  to  get  on  the  air  for 
some  ham  contacts. 

After  an  eyeball  QSO 
with  another  ham.  Bud 
9V10I,  Jules  purchased  a 
ticket  at  the  airport  and 
flew  to  Bangkok,  Thailand, 
where  he  met  Bill 
HS1ACU,  and  a  former  co- 
worker from  Delano,  Dean 
Bartelet 

During  the  weekend  In 
Bangkok,  Jutes  went  to  the 
coast.  He  said  he  saw  many 
"water  scooters''  being 
used.  They  are  a  very 
popular  sport  here  and 
something  one  just 
wouldn't  think  people  on 
the  other  side  of  the  world 
would  be  doing.  And  the 
traffic  in  Bangkok?  "It  was 
bedlam/'  lules  mentioned, 
"with  motor  scooters, 
bikes,  rickshaws,  taxis,  and 
wagons  everywhere." 

On  Sunday,  Jules  con- 
tacted Dieter  HS1ALG,  an 
electronics  professor  at 
Bangkok  University.  At 
Dieter's  apartment,  they 
got  on  the  air  for  some 
good  DX.  One  nice  chat 
was  with  Bill  W7PHO,  a 
well-known  ham  in  the  DX- 
world  from  Seattle. 


While  Jules  was  here,  he 
learned  that  there  is  no  of- 
ficial licensing  in  Thailand. 
A  person  interested  in 
becoming  a  ham  must  join 
a  radio  ctub  and  then  be 
issued  a  call  through  the 
club.  Kam  HS1WR  runs  the 
show. 

After  a  five-day  en- 
joyable stay  in  Bangkok, 
fules  took  a  two-hour  flight 
back  to  Singapore.  Upon 
arrival,  he  learned  that  the 
ship's  stay  had  been  ex- 
tended a  few  more  days  in 
port.  This  gave  him  a 
chance  to  do  a  little  more 
visiting. 

Bud  9V10I  and  his  wife, 
Jan,  hosted  Jules  for  dinner 
one  night.  Jan,  whom  Jules 
complimented  about  being 
an  excellent  cook,  would 
like  to  open  a  Chinese 
restaurant  in  southern 
California  after  Bud  retires. 
From  the  way  Jules  praised 
her  cooking,  especially  the 
chicken  wings  in  a  special 
sauce,  I'm  sure  her 
restaurant  would  be  a 
great  success. 

Bud  lives  in  a  20-story 
apartment  building  and  his 
beam  is  about  280  feet 
above  ground.  This  sure 
makes  for  good  DXing. 
Jules  got  some  air  time  and 


again  talked  to  John  W6UZ 
back  in  Delano.  He  said  the 
DX  was  very  good. 

I  ules  went  to  the  post  of- 
fice and  had  this  to  say: 
"Mailing  tetters  in 
Singapore  was  a  chore  You 
always  had  to  wait  in  a 
long  line  Boy,  they  weigh- 
ed every  letter,  wrote  down 
the  price,  and  then  gave 
you  a  stamp  separately  for 
every  card  or  letter,  On 
postcards,  you  had  to  stick 
on  an  air  mail  sticker, 
Bothe  the  stickers  and 
postage  stamps  had  very 
little  glue  on  them.  You'd 
stick  'em  down  and  they'd 
come  off.  They  had  glue 
bottles  all  over  and  you'd 
get  glue  alld  over  your 
fingers,  and,  oh,  what  a 
mess/' 

When  the  Trader  was  in 
Tahiti,  the  ship's  radar 
went  out,  and  the  replace- 
ment part  caught  up  with 
the  ship  in  Singapore  Jules 
assisted  in  its  installation. 
It  arrived  at  the  proper 
time. 

When  leaving  Singapore 
and  sailing  through  the 
straits,  two  extra  crew 
members  had  to  serve  as 
lookouts  on  the  bridge 
because  there  were  so 
many  other  ships  coming 


142 


and  gofng.  Half  of  them 
didn't  have  fights,  "It  was  a 
nightmare/'  Jules  said, 
"We  were  thankful  that  the 
radar  was  working  again/' 

As  the  Trader  sailed 
toward  Penang,  Jules  said 
the  DX  was  good  only  in 
the  evening.  When  the  ship 
got  closer  to  Penang,  he 
made  contact  with  Mai 
9M2MW  and  tried  to  ad- 
vise  him  that  the  ship 
would  be  in  port  in  the 
morning.  The  signals  were 
too  weak,  but  Harry 
K6MOO  heard  both  of 
them  very  clearly,  and  in- 
stead of  a  100-mile  direct 
contact,  a  round-trip  relay 
of  over  15,000  miles  was 
made. 

After  the  Trader  an- 
chored at  Penang  on 
August  3,  Jules  went  to  the 
post  office.  While  he  was 
standing  in  line  with  some 
of  the  other  passengers, 
this  fellow  came  in  and 
asked  another  American  if 
he  knew  Jules.  Well,  Jules 
was  standing  only  a  few 
feet  away,  It  was  Eshee 
9M2FK,  whom  he  had 
worked  earlier  when  at  sea. 
They  left  the  post  office 
and  called  Mai  9M2MW, 
who  met  them;  later,  all 
three  went  back  to  the 
ship.  They  got  on  40  meters 
and  worked  several  of  the 
local  hams  who  were  on  a 
net. 

One  of  the  trips  Jules 
took  here  was  up  the  side 
of  Penang  Mountain,  As 
one  of  the  cable  cars  goes 
up,  another  one  comes 
down.  They  both  use  the 
same  single  tracks.  About 
midway  up,  the  tracks 
divide  into  passing  tracks. 
(There  had  better  be  no 
mistakes  here.)  From  the 
top,  Jules  could  see  the 
two  bright  lights  aboard 
the  Yarikee  Trader,  some 
five  miles  away  in  the 
straits. 

Mat  9M2MW  and  his 
wife,  Patricia,  also  hosted 
Jules  one  night  for  dinner. 
Mai  is  interested  in 
Teletype^M      and      has 

several   pieces   of   RTTY 


etjuipment  some  of  which 
is  home  brew  While  he  was 
here,  he  met  Chong  9M2DJ 
andTan9M2DW. 

Jules,  along  with  some 
other  hams,  helped  in  tak- 
ing down  MaTs  mast  and 
tri-band  antenna.  The 
weather  and  corrosion  had 
attacked  the  connections 
and  the  swr  was  getting 
high.  He  said  it  was  a 
miracle  that  they  got  it 
down  in  one  piece,  due  to 
the  small  area  in  the 
backyard. 

While  here  in  Penang, 
Jules  visited  the  home  of 
Eshee  9M2FK,  who  works 
for  the  port  authority.  His 
radio  shack,  located  in  the 
back  of  his  home,  is  a  very 
neat  layout.  In  his  portfolio 
of  awards  and  certificates, 
Jules  found  an  award  from 
the  Northern  California  DX 
Club. 

The  time  had  finally  ar- 
rived for  Jules  to  leave 
Penang.  Within  a  few  hours 
after  setting  sail  for  Colom- 
bo, he  contacted  a  ham  at 
Clark  Air  Force  Base  in  the 
Philippines.  He  received 
the  satellite  weather  report 
for  the  area  which  showed 
pretty  good  weather.  Later, 
he  got  into  Reunion  Island 
(FR7)  for  an  unusual  con- 
tact, and  then  several  U.S. 
stations.  He  also  talked  to 
John  4S7JD,  the  manager 
of  the  Voice  of  America 
radio  station  in  Sri  Lanka. 

For  the  next  few  days, 
Jules  filled  several  pages  of 
his  logbook  working  sta- 
tions all  over  the  world.  He 
said  he  even  had  a  perfect 
contact  with  an  American 
at  the  embassy  in  Brasilia, 
Brazil.  He  also  checked  in- 
to the  SEANET  (South  East 
Asia  Net],  which,  at  the 
time,  was  being  run  by  Carl 
S79R,  in  the  Seychelles. 
Also,  one  evening,  Jules 
worked  about  seven  4S7s;  a 
couple  of  them  were  at  the 
home  of  John  4S7JD. 

On  August  13,  the  Trader 
pulled  into  Colombo,  Sri 
Lanka  (formally  Ceylon), 
after  sailing  five  days  from 
Malaysia.    Most    of    the 


passengers  set  out  for 
various  parts  of  the  coun- 
try, but  Jules  had  personal 
guides  waiting  for  him  at 
the  dock.  It  was  John 
4S7JD  and  Shanti  4S7WP, 
a  radio  operator  aboard  a 
tanker  out  of  Colombo. 

Since  J  ules  was  to  be  the 
house  guest  of  John  4S7JD 
for  the  duration  of  his  stay 
here,  that's  where  he  went. 
Jules  and  John  had  first 
worked  each  other  when 
John  was  in  Liberia  back  in 
1965.  This  was  the  first 
time  they  had  ever  met  in 
person  and  they  had  plenty 
to  talk  about,  having 
mutual  friends  in  the  VOA. 

John  had  invited  many 
of  the  hams  over  to  his 
home  to  meet  Jules.  About 
6:00  pm,  they  began  to  ar- 
rive. Jules  met  the  follow- 
ing: Fernando  4S7BC; 
Senevi  4S7SW,  whom  Jules 
had  worked  in  the  past 
years  and  on  the  way  over; 
Vasanth  4S7VC;  Ernest 
4S7EA;  Guru  4S7PG;  and 
Paddy  4S7PB. 

The  following  are  ex- 
cerpts from  a  tape  record- 
ing made  in  John's  home 
on  August  14,  1977,  of 
some  of  the  hams  who 
were  visiting  with  Jules. 
This  first  one,  Jules  said,  is 
Paddy  4S7PB. 

"Right  now  we're  here 
with  457  hams,  and  Jules 
W6YO  is  with  us.  He  wants 
me  to  say  a  few  words  to 
start  with,  May  I  say  a  very 


good  evening  to  all  the 
gang  in  the  Northern  and 
Southern  California  DX 
Clubs,  and  I  wish  I  were 
with  you  as  I  was  some 
time  back,  ten  years  ago  — 
in  fact.  1967  Wish  you  all 
the  best  in  good  propaga- 
tion for  the  next  umpteen 
years.  Bye-bye." 

''Good  evening,  my 
brother  hams  in  California, 
This  is  Ernest  4S7EA  with 
Jules  and  my  brother  hams 
here  at  4S7JD's  shack  I  will 
say  '{couldn't  catch  the 
phrase)'  to  you  all  Which 
is,  in  our  own  lingo,  'May 
your  life  be  long/  That  is 
how  we  say  it.  It's  very  nice 
meeting  Jules  and  I  have 
had  the  pleasure  of 
meeting  many  W6s  on 
Charlie  Willie.  I  look  for- 
ward to  meeting  you  once 
again,  especially  my  friend 
Jules,  when  he  goes  back 
home.  Bye  for  now.  73/' 

"Hello  boys,  this  is  4S7 
Baker  Charlie  speaking.  I 
was  very  happy  to  work  my 
good  friend  Jules  some 
days  ago.  He's  my  own  age. 
Vw  very  happy  to  know 
that  (laughter).  Our  rigs,  as 
you  know,  are  mostly 
home  brew  and  mine  is 
also  a  home-brew  one.  I've 
been  getting  quite  a 
number  of  stations  with 
really  good  signal  strength. 
Wish  you  all  the  best  till  we 
possibly  meet  you  on  the 
band  again.  Cheerio/' 

[4S7SW)    ''Hello,    my 


What  you  see  is  almost  all  of  the  town  of  Dzaoudzi, 
Mayotte,  Frer)ch  Comoros.  It  was  here  in  a  tittte  8-room 
hotel  where  }ules  operated  with  the  call  of  FH0YO. 


143 


friends  in  the  United 
States,  I've  been  having  a 
nice  time  with  Jules  over 
here.  There  are  altogether 
about  seven  hams  here; 
we're  all  having  a  nice 
time.  That's  about  all  from 
here.  I'll  pass  this  over  to 
my  good  friend,  Victor 
George." 

''Good  evening,  friends, 
this  Is  4S7  Victor  George 
and  we  are  having  a  very 
fine  time  with  old  man 
Jules  here.  I  would  hope  to 
meet  many  of  the  boys  on 
the  air  very  soon,  73  and 
wishing  you  an  eyeball 
from  Sri  Lanka.  4S7VG, 
off/' 

A  couple  of  days  later, 
Jules  was  invited  to  the 
home  of  Shanti  4S7WP  for 
a  four-  or  five-course  din- 
ner that  Jules  said  was  very 
delightful. 

Shanti  showed  Jules  a 
VP9BM  QSL  card  dated 
1955.  VP9BM  is  a  former 
call  held  by  Jules  when  he 
was  living  in  Bermuda,  "t 
guess  Shanti  was  my  first 
4S7;"  Juies  mentioned, 
"and  I  was  his  first  VP9.  It 
was  great  to  see  the  card/' 
He  also  had  cards  from 
Don  W6BVM  and  Leon 
W6BYH  from  Delano, 
Jules's  home  town.  On  top 
of  that  was  a  Delano 
Amateur  Radio  Club  cer- 
tificate, #45,  dated  23  of 
July,  1955,  for  working  five 
of  the  club  members. 

One  day,  at  John's 
home,  Jules  met  Soma 
4S7YL  and  her  OM,  Wick 
4S7WA-  They  talked  about 
DXand  she  presented  Jules 
with  an  eyeball  QSL  card 
and  a  kiss  on  the  cheek. 
Jules  had  also  worked  her 
when  she  was  8Q6AC  in  the 
Republic  of  Maldives. 

Before  Jules  left  Colom- 
bo, John  took  him  out  of 
town  about  20  miles  to  the 
Voice  of  America  transmit- 
ter  site,  one  of  several 
located  in  different  coun- 
tries around  the  world. 
Sfnce  Jules  had  only 
recently  retired  from  the 
VOA  in  Delano,  this  was 
almost  like  being  at  home. 

All  visits  to  the  various 


countries  and  islands  must, 
sooner  or  later,  come  to  an 
end  Many  hams  were  met 
on  Sri  Lanka,  and  the 
memories  will  always  be 
pleasant. 

After  the  Trader  set  sail 
for  the  Maldives,  Jules  got 
on  the  air  and  worked 
some  good  DX.  Contacts 
were  made  with  KZ5KN, 
Canal  Zone,  and  VP2MH, 
Montserrat  Another  good 
QSO  was  held  with  Bill 
W7PHO,  and  later  with 
Father  Moran  9N1MM,  in 
NepaL 

The  Trader  dropped  an- 
chor at  5:15  pm  on  Thurs- 
day, August  25,  about  a 
half  mile  off  shore  at  Male, 
Maldives,  an  island  group 
off  the  tip  of  India,  and  on- 
ly a  few  degrees  north  of 
the  equator. 

One  of  the  first  things 
Jules  did  was  to  check 
about  operating  amateur 
radio  from  the  island,  A 
customs  official  told  him 
that  no  radio  transmissions 
of  any  type  were  allowed 
from  the  island  or  from  a 
ship  in  the  harbor.  It  was 
strictly  prohibited.  Jules 
was  very  disappointed. 

With  only  48  hours  here, 
one  might  as  well  enjoy  it, 
so  Jules  did  a  little  shop- 
ping and  sight-seeing.  He 
also  did  some  more 
snorkel ing.  He  said  the  fish 
were  very  beautiful,  and 
even  got  to  touch  some  of 
them.  The  water  was  so 
clear  one  could  see  a  hun- 
dred feet  away. 

On  the  last  day  in  port, 
Jules  went  to  the  Telecom- 
munications Department 
to  see  what  the  re- 
quirements were  to  get  per- 
mission to  operate  here. 
Jules  was  "shocked"  when 
Mohamed  Ismail  Maniku, 
Director  of  Telecom- 
munications, gave  him  per- 
mission to  operate  in  the 
Maldives  Jules  asked 
Maniku  if  he  would  like  to 
become  a  ham.  He  said 
yes.  Jules  said  he  would  do 
everything  possible  to  help 
him  become  an  amateur 
radio  operator. 

Jules  asked  if  other  hams 


could  operate  from  the 
island  and  was  told  that 
they  could.  There  are  no 
customs  or  great  for- 
malities  necessary. 

Jules  could  have  re- 
ceived  an  8Q  call,  but  with 
only  a  few  hours  remaining 
before  the  ship  left  the 
island,  there  wasn't  time  to 
wait,  so  he  was  given  per- 
mission to  operate  as 
W6YO/8Q,  He  worked  all 
continents  within  two 
hours  after  returning  to  the 
ship  and  getting  on  the  air. 
He  would  have  liked  more 
air  time,  but  the  ship  was 
about  to  saiL 

For  the  March,  '77,  issue 
of  73  Magazine,  I  wrote  the 
article  "Pttcairn  Island-an 
inside  look  at  VR6TC"  I 
mailed  a  copy  to  Jules  and 
he  received  it  in  Tahiti, 
Before  leaving  the 
Maldives,  he  gave  that 
copy  to  Maniku.  I'm  sure 
he  read  it  from  cover  to 
cover. 

The  ship  left  at  4:00  pm 
and  Jules  worked  a  lot  of 
stations  en  route  to  the 
Seychelles,  He  worked  a 
PY,  9Y4,  VK,  and  many 
Europeans,  as  well  as  many 
stateside  contacts. 

In  issue  #8  of  the  Trader 
Tales  newsletter,  Jules 
wrote:  "Good  ole  Uncle 
Sam  is  at  our  service.  Here 
around  the  Indian  Ocean, 
CI  'hams' at  Clark  Air  Force 
Base  and  the  Subic  Bay 
U.S.  Navy  base,  both  the 
Philippines,  and  with  the 
U.S.  Navy  at  Diego  Garcia 
in  the  Chagos  Archipelago, 
pass  on  to  me  the  latest 
weather  data  for  requested 
areas,  gathered  from 
weather  satellites.  In  the 
Pacific,  the  Honolulu  and 
Guam  satellite  service  was 
even  'phone-patched'  to 
me  directly  from,  and  to, 
the  weather  plotting  sta- 
tion. 

"In  the  Indian  Ocean, 
this  service  was  provided 
through  the  generosity  of 
one  particular  amateur 
radio  station,  WA4RQK/ 
VQ9,  Jim,  the  operator 
there,  has  been  most 
helpful;  this  is,   I  believe. 


because  we  are  'Yanks/ 

"Another  great  service 
we  have  all  around  the 
world,  and  particularly 
here  in  the  Indian  Ocean,  is 
the  SEANET,  which  stands 
for  South  East  Asia  Net, 
with  participating  amateur 
radio  operators  surround- 
ing the  1  ndian  Ocean,  and  a 
'net  control'  station  which 
supervises  all  'hams' 
checking  in,  to  offer  any 
possible  assistance  over 
the  air  or  to  relay 
telephone  calls.  This  net 
control  station  is  being 
handled  by  a  most  out- 
standing and  capable  per- 
son by  the  name  of  Carl 
Reder  S79R,  who  makes  his 
home  in  Victoria  on  Mahe 
Island,  Seychelles  (our  next 
port  of  call),  Carl  can  in- 
stantly remember  the  'han- 
dle' of  any  one  he  has  con- 
tacted before,  and  there 
are  several  dozen  stations 
who  check  in  every  eve- 
ning. 

Six  days  of  sailing 
brought  the  Trader  to  Vic- 
toria, Seychelles.  Jules  met 
Carl  and  spent  a  great  deal 
of  time  with  him  going  to 
various  places  on  the 
island.  They  visited  a 
religious  high*power  short- 
wave broadcast  station 
and  Jules  stated  that  the 
300-foot  towers  and  anten- 
nas were  all  out  in  the 
water  —  a  very  unusual 
setup.  Jules  even  had  the 
opportunity  to  watch  some 
speedboat  and  yacht  races. 
An  unusual  treat  for  an 
area  such  as  this. 

Time  never  stands  still, 
so  the  time  had  come  to 
depart  from  yet  another 
island.  After  getting  to  sea, 
Jules  made  contact  with 
Jim  WA4RQK/VQ9  and 
received  the  weather 
report  for  their  trip  to 
Mombasa,  Kenya  He  also 
made  contact  with  Ted 
5Z40T,  in  Nairobi,  whom 
he  hoped  to  visit  upon  ar- 
rival. He  talked  to  Ray 
5Z4PR,  also  in  Nairobi,  and 
was  invited  to  stay  at  his 
place  for  a  visit  He  even 
gave  Jules  two  phone 
numbers  to  call  when  the 


144 


ship  clocked.  Another  con- 
tact was  with  a  Cape  Town 
ham  whom  he  will  meet 
when  the  Trader  arrives  in 
South  Africa. 

Once  every  24  hours 
while  at  sea  during  this 
around-the-worid  cruise, 
Jules  had  to  take  the  wheel 
(helm)  for  two  hours.  One 
morning  white  doing  so,  he 
said,  "We  could  hear  birds 
chirping  away.  I  was 
wondering,  gosh,  we're  500 
miles  away  from  land  and  a 
bird's  here?''  Later  that 
morning,  someone  saw  a 
bird  up  in  lules's  antenna 
All  of  a  sudden  it  dropped 
and  fell  into  the  ocean 
alongside  the  ship.  No  one 
could  understand  what  had 
happened  until  they 
looked  up  again  and  saw 
one  of  the  bird's  wings 
stuck  in  the  antenna.  Jules 
said,  ''It  must  have  gotten 
wedged  in  one  of  the  cor- 
ners of  the  wire  and 
fiberglass  outrigger  sup- 
porting the  antennas." 

No  matter  where  you 
might  be  in  this  world, 
there  is  always  time  for  be^ 
ing  a  volunteer  instructor 
for  Novice  class  students. 
The  Yankee  Trader  on  the 
high  seas  is  no  exception. 
Jules  started  a  Novice  code 
class  with  three  students, 
and  every  afternoon  at  3 
o'clock  he  gave  three* 
quarters  of  an  hour  of  code 
practice.  All  of  his 
students,  at  this  stage  of 
the  trip,  were  very  en- 
thused about  getting  an 
amateur  radio  operator's 
license.  Jules  said  they 
were  doing  pretty  welL 

When  the  Trader  arrived 
at  Mombasa,  Kenya,  many 
of  the  passengers  headed 
for  the  interior  to  visit 
some  of  the  preserves  and 
parks.  Jules  headed  inland, 
also. 

When  he  took  the  bus  to 
Nairobi,  he  had  hopes  of 
seeing  19,340-foot  Mount 
Kilimanjaro  in  Tanzania, 
near  the  border  of 
Kenya.  Unfortunately,  the 
weather  didn't  cooperate; 
it  was  overcast  The  trip, 
some  300  miles,  was  on  a 


narrow  bumpy  road.  The 
dust  was  terrible.  Jules  ex- 
pected to  see  numerous 
wild  animals,  but  only  a 
few  were  actually  seen. 

When  he  arrived  in 
Nairobi  he  called  Ron 
5Z4RC,  and  later  they  met. 
Ron  took  Jutes  out  to  their 
coffee  plantation  where  he 
meet  Philomena  5Z4PC, 
Ron's  XYL.  He  got  some  air 
time  and  had  a  long  QSO 
with  a  close  friend,  Frank 
W6KPC,  on  15  meters. 
Jules  said,  ''He  had  a  very 
good  signal,  but  no  other  6s 
were  heard/'  He  enjoyed  a 
hot  bath  and  delightful  din- 
ner Phil  had  prepared. 

The  next  day,  in 
downtown  Nairobi,  Jules 
met  Ted  5Z40T,  and  they 
had  a  very  nice  chat.  While 
here  in  town,  he  said  he 
walked  so  much  just  sight- 
seeing  that  his  feet 
became  sore  and  swollen. 
He  also  took  a  four-  to  five- 
hour  tour  of  a  wild  game 
preserve  20  miles  from 
town.  He  left  that  night  for 
the  return  trip  to  Mombasa 
and  tt  rained  most  of  the 
way  back, 

Jules  had  purchased  an 
antique  brass  washbasin 
(he  called  it  a  spittoon]  as  a 
souvenir  and  was  carrying 
it  when  the  following  oc- 
curred about  a  block  from 
the  gate  to  the  docks; 

"A  fellow  came  up  from 
behind  me  and  grabbed  for 
my  wristwatch.  With  both 
hands,  he  pulled  down,  but 
I  didn't  have  an  expanding 
band  and  it  wouldn't  come 
loose.  I  gripped  it  and  held 
on  when  it  slipped  to  my 
hand.  He  pulled  me  over 
and  I  fell  to  the  road,  tore 
my  trousers,  and  got  a 
bruise  on  my  knee,  tt 
scratched  my  wrist,  too, 
from  the  sharp  wristband.  I 
swung  at  him  with  the  spit- 
toon, but  I  missed  him.  I'd 
liked  to  have  dented  his 
head  wrth  it  He  ran  across 
the  street.  Luckily,  I  got 
away  without  getting 
beaten  up  or  having  my 
wallet  or  camera  stolen." 

Jules  reported  the  inci- 
dent, but  that's  about  all 


This  is  Cape  Agulhas,  southernmost  tip  of  Africa.  The 
unusua!  feature  is  in  the  whitecsp  water  seen  between  the 
rocks.  It  is  the  dividing  point  for  the  Indian  Ocean  on  the 
left  and  the  Atlantic  Ocean  on  the  right..  . 


that  could  be  done.  It  was 
quite  an  experience,  ex- 
pecially  when  you're  about 
to  leave  the  country  and 
head  for  another  port. 

Two  days  out  of  Mom- 
basa, the  passengers  were 
treated  to  what  you  might 
call  "porpoises  on 
parade."  It  was  a  spec- 
tacular display  of  por- 
poises, mostly  in  front  of 
the  ship.  There  were  hun- 
dreds of  them  leaping  in 
and  out  of  the  water  in 
their  acrobatic  swimming 
and  playful  jumps. 

Since  the  Trader  arrived 
at  Mutsamudu,  Anjouan 
Island,  Independent  Com- 
oros, in  the  evening,  Jules 
decided  to  stay  on  board. 
The  following  day  he  took 
a  bus  tour  of  the  island  and 
saw  many  of  the  plants 
from  which  perfume  is 
made.  He  even  took  a  tour 
of  a  perfume  factory  where 
flowers  are  processed  and 
a  liquid  is  extracted  from 
them.  From  this  liquid,  a 
perfume  is  made.  "The 
tour,"  Jules  said,  "was 
quite  enjoyable."  That 
evening  the  ship  set  sail  for 
an  overnight  trip  to 
Mayotte  Island,  French 
Isles  de  Comoros. 

When  Jules  was  in 
Miami,  he  had  asked  the 
captain  about  stopping  at 
the  Comoros  since  it  wasn't 


a  scheduled  stop.  The  cap- 
tain said  he  was  agreeable 
and  would  like  to.  In  issue 
#9  of  the  Trader  Tales,  j  ules 
wrote  another  short  piece 
titled,  "Perfume  Islands  At- 
tract Ham  Operator." 

"The  Comoro  Islands 
were  first  called  the  Per- 
fume Islands,  for  they  at- 
tracted perfume  mer- 
chants to  buy  the  strong- 
scented  oil  extracted  from 
the  ylang-ylang  tree 
flowers. 

"Today,  the  islands  have 
another  attraction  to  the 
hams  around  the  world:  a 
rare  island  country*  This  in- 
spired me  to  operate  my 
radio  equipment  ashore  in 
a  small  hotel  overlooking 
the  bay  at  Dzaoudzi, 
Mayotte.  On  September  26 
and  27,  in  the  wee  hours  of 
morning,  during  fair  condi- 
tions, in  less  than  five 
hours,  I  made  318  contacts, 
mostly  with  stateside  sta- 
tions. Many  thanks  from 
myself,  and  I'm  sure  from 
the  lucky  ones  who  made  a 
QSO,  to  Yvon  Seguineay 
for  issuing  me  the  license 
and  call  FH0YO,  AI  Fox,  an 
American  visiting  Mayotte 
who  helped  in  the  opera- 
tion, and  especially  Cap- 
tain Paul  Maskell,  skipper 
of  the  Yankee  Trader,  for 
stopping  here." 

Long  before  the  Trader 


145 


Mac  ZS1LK  and  jutes  W6YO  beside  the  Yankee  Trader,  docked  in  Cape  Town,  South 
Africa,  Mac  is  one  of  many  hams  }ules  met  while  here  in  this  very  beautiful  country. 


arrived  at  Mayotte,  Jules 
had  contacted  Al 
VP2LOX/MM1  by  radio  and 
talked  to  him  about  getting 
a  license  to  operate  from 
the  island.  When  the  ship 
docked,  At  was  there  to 
meet  him.  He  had  received 
the  call  of  FH0FX  for 
himself  and  FH0YO  for 
Jules.  They  were  all  set  for 
an  amateur  radio  DXpedi* 
tion. 

After  a  stop  to  see  ACs 
yacht  and  meet  his  XYL, 
Eva,  they  headed  for  the 
only  local  hotel  (B-room) 
and  started  getting  things 
ready  for  the  special  opera- 
tion. They  obtained  a  lad- 
der to  get  up  on  the  roof 
and  dipotesfor  both  15  and 
20  meters  were  installed. 
The  low  ends  were  tied  to  a 
rock  down  on  the  beach. 
Everything  was  set  up  out 
on  the  balcony. 

The  first  QSO  on  20  SSB 
at1200UTC  [3:00  PM  local 
time)  as  FH0YO,  Mayotte, 
Comoro  Islands,  was 
W3NX,  5X7  both  ways, 
followed  by  YB0AAU. 
W3LMA,  and  then  W3KT. 
The    first   hour   produced 


nearly  60  QSOs.  Jules  said 
he  worked  into  Central 
America  very  well,  but  on- 
ly picked  up  one  station  in 
Australia.  It  was  Merv 
VK4MW,  whom  he  had  met 
several  months  earlier  dur- 
ing a  visit  to  that  country, 
Most  of  the  QSOs  as 
FH0YO  were  on  20  meters; 
a  total  of  228  contacts 
were  made 

Operation  on  15  meters 
was  with  the  call  of  FH0FX. 
There  were  90  contacts 
made  here  before  the  band 
folded.  Jules  stated  that 
most  of  the  stateside  con- 
tacts were  from  the  3rd, 
4th,  and  5th  districts.  He 
missed  ''Worked  All  Con- 
tinents" by  one:  the  one 
closest  to  his  location  — 
South  Africa. 

"1  was  working  spht, 
transmitting  with  an  FT-101 
down  on  14.195  and  tuning 
with  the  Atlas  around  200 
to  220.  Later  in  the 
evening/'  Jules  stated,  "I 
was  tuning  above  275,  still 
transmitting  on  195, 

"I  even  worked  a  station 
running  1  Watt;  W80K  got 
me  to  stand  by  for  him.  The 


station  was  W8ILC.  It  was 
something.  He  was  3X2. 

"Most  of  the  reports  we 
were  giving  were  5X7,  We 
received  some  20  over  S9 
reports,  with  20  meters  be- 
ing much  better  in  signal 
reports  than  15." 

I  personally  don^t  know 
if  any  other  hams  have 
gone  to  Mayotte  and 
operated,  but  from  the  ap* 
pearance  and  success  of 
what  Jules  did,  this  sounds 
like  an  excellent  spot  for 
an  extended  DXpedition. 
The  Trader  was  here  for 
less  than  24  hours  and  they 
did  pretty  well  with  what 
time  was  available,  thanks 
to  Yvon  FH8CY,  Director  of 
Telecommunications,  who 
was  responsible  for  issuing 
the  calls. 

After  leaving  the  island, 
the  Trader  sailed  toward 
the  Juan  de  Nova  Island 
group  in  the  Mozambique 
Channel.  From  there,  they 
turned  and  headed  for 
Tulear,  Madagascar.  When 
the  ship  arrived,  Jules  went 
into  town  but  didn't  do  too 
much.  The  next  day,  of- 
ficials restricted  everyone 


to  the  ship,  so  the  follow- 
ing day  they  shoved  off  for 
Cape  Town,  South  Africa. 

At  this  point  in  the  trip, 
Jules  mentioned  that  the 
three  Novice  students  he 
had  were  doing  pretty 
well  — about  5  wpm  on  the 
code.  They  would  be  ready 
for  their  tests  by  the  time 
the  Trader  reached  South 
America, 

The  bands  were  very 
good  here  at  sea.  He  had  a 
QSO  with  Bill  ZS1ER, 
whom  he  had  contacted  on 
other  occasions.  Jutes 
planned  on  visiting  Bill 
when  the  ship  arrived  in 
Cape  Town. 

Another  contact  was 
with  a  ham  at  37,000  feet. 
It  was  Fred  W7UKC/AM3 
aboard  a  747  en  route  from 
Seattle  to  Tokyo.  He  was 
somewhere  between  Alas- 
ka and  Siberia.  It  was  a 
good,  long  QSO. 

"Oh,  it  was  a  beautiful 
sight,'"  Jules  said,  "coming 
in  to  see  Table  Top  Moun- 
tain, Lion's  Head,  Signal 
Hill,  and  the  terrific  skyline 
of  Cape  Town.  The  large 
buildings  could  be  seen  for 
miles  and  miles.  It  is  just  a 
tremendous-looking  city. 
The  harbor  reminds  you  of 
Rio  de  Janeiro;  kind  of  a 
round  horseshoe  bay.  Fan^ 
tastic!  There  were  dozens 
of  cranes  about  200  feet 
high,  and  large  tanker 
ships.  You  couldn't  count 
them  all-  It  was  nice  to  get 


in 


tf 


It  was  Sunday  morning, 
October  9,  when  the  Trader 
moved  up  to  a  pier  near  the 
yacht  club  in  Cape  Town. 
"Believe  it  or  not/'  Jules 
said,  "'on  the  dock  was  Bill 
ZS1 ER.  He  was  the  first  one 
to  shake  hands  with  me 
before  we  even  had  the 
gangplank  down/' 

Bill,  along  with  his  XYL 
and  two  boys,  took  Jules 
down  the  coast  to  the  Cape 
of  Good  Hope  and  Cape 
Aguthas,  southernmost  tip 
of  Africa,  for  a  nice  view  of 
the  country.  They  had  a 
really  nice  day  and  even 
drove  to  a  hill  and  saw  all 
the   night   lights   of   Cape 


146 


Town.  On  another  day,  Bill 
and  his  family  took  Jules 
up  the  coast  for  an  all-day 
trip  where  he  met  Mac 
ZS1LK  and  family.  Jules 
stayed  at  Mac's  home  and 
they  got  in  a  littfe  air  time. 
Mac  is  quite  active  on  2 
meters  as  well  as  the  HF 
bands. 

Jules  said  Mac  has  a  lit- 
tfe two-year-old  son,  Jamie, 
who  really  took  to  him.  He 
said,  ''We  really  made 
friends  — the  cutest  little 
fellow  you  ever  wanted  to 
see.''' 

Mac  took  Jules  to  the 
yacht  club,  where  a  lot  of 
people  asked  him  a 
number  of  questions  since 
he  was  from  the  U.S,  White 
they  were  there,  'The  first 
leg  of  the  around-the-world 
yacht  race  from  England 
came  in,"  Jules  com- 
mented. "There  were  some 
beautiful  yachts." 

Jules  also  met  Dick 
W60Z,  the  radio  operator 
off  a  large  freighter  from 


New  Orleans.  Later,  Jules 
took  him  aboard  the  Trader 
for  a  visit.  They  even  had 
breakfast  aboard  Dick's 
ship  one  morning. 

Another  ham  Jules  met 
was  Danie  ZS1X.  He  went 
to  his  home  which  was 
right  on  the  beach,  A  very 
picturesque  location. 
Danie  does  a  lot  of  ex- 
perimenting with  ham 
equipment.  His  XYL  was 
about  to  get  her  ham 
license. 

The  word  apparently  got 
out  about  Jules  being  in 
Cape  Town,  and  a  lot  of 
operators  wanted  to  meet 
him  personally.  "I  met 
quite  a  few  hams.  They 
always  seemed  to  be  com- 
ing  around.  There  was/^ 
Jules  commented,  "a  con- 
tinuous stream  of  them/' 

Jules  was  impressed  with 
the  modern  buildings  in  the 
city.  He  mentioned  that 
they  have  modern  free- 
ways and  overpasses.  The 
train  station  is  as  beautiful 


and  more  modern  than 
J  u les  had  seen  i n  the  states. 
This  is  a  very  progressive 
city.  The  people  were  very 
polite  and  courteous.  The 
shops  had  a  very  good 
selection  of  souvenirs. 
Jules  even  had  a  T-bone 
steak  at  the  Town  House, 
the  first  since  leaving  the 
states  back  in  February. 
The  dinner  was  a  little  over 
$4.00. 

"The  hams  here  were 
sure  nice/'  Jules  said,  "par- 
ticularly Mac  ZS1LK  and 
Bill  ZSIER."  Mac  came  to 
see  Jules  off  at  11  o'clock 
on  October  21,  They  had 
some  coffee  out  on  the 
deck  while  having  their 
final  eyeball  QSO.  Mac 
was  one  of  the  last  to  leave 
the  Trader  before  she  set 
sail  for  St.  Helena. 

It  was  some  1,700  miles 
to  Jamestown,  St.  Helena, 
from  Cape  Town,  South 
Africa,  Before  the  Trader 
arrived,  she  had  sailed 
some  25,143  miles  in  this 


10- month  around-the- 
world  cruise.  For  Jules 
Wenglare  W6YO,  it  would 
be  another  adventure  in 
yet  another  country.  It 
would  also  be  a  location 
for  another  DXpedition  for 
Jules  as  ZD7YO. 

In  three  parts,  I  have 
covered  eight  months  of 
travel  with  Jules  aboard 
the  Yankee  Trader  on  the 
high  seas  and  the  ports  of 
call  visited.  In  part  IV,  the 
Trader  will  sail  another 
5000  miles  and  stop  at 
another  dozen  locations. 
Jules  will  meet  and  par- 
ticipate with  other  hams  in 
celebrating  40  years  as  a 
ham  for  Vic  PY7AN  in 
Recife,  Brazil, 

On  the  island  of  Car- 
riacou,  Jules  eats  part  of  an 
apple.  Within  a  few 
minutes  his  mouth  and 
throat  began  to  burn.  He 
later  learns  that  it  was 
poisonous.  In  fact,  the  tox- 
ic apple  has  been  fatal  to 
small  children.  ■ 


Nen^  Products 


from  page  23 

side-by-sldeonasmall,  2-1/S"  x 
5"  X  1-1/8"  base  of  satin  chrome 
with  a  black  plastic  top.  The  big 
difference  between  the  QUIK- 
KEY  and  conventional  keyer 
paddles  is  that  it  js  manipu- 
lated by  downward  pressure,  as 
with  a  straight  key,  instead  of 
by  horizontal  pressure. 

One  of  the  problems  I've 
always  had  with  keyer  paddles 
is  that  the  way  I  bang  away 
while  sending,  the  paddle 
skates  about  on  the  operating 
desk.  Short  of  screwing  the 
paddle  down  solidly  as  I  do  with 
a  straight  key,  I  simply  haven't 
been  able  to  keep  one  in  the 
same  spot  wittiout  holding  it 
down  with  my  other  hand,  To 
my  delight,  the  QUIK  KEY  has 
eliminated  that  problem.  The 
combination  of  the  weighted 
base  and  downward  pressure 
when  manipulating  the  keying 
levers  makes  for  very  stable 
operation.  Even  with  the  way  I 
thump  it  about,  the  QUIK-KEY 
stays  In  place. 

Another  impressive  feature 
of  the  QUIK-KEY  is  its  physical 
appearance.  Quality  materials 
and  precision  machining  make 


for  smooth  operation  and  good 
looks.  Personalizing  each  pad- 
dle with  the  operator's  call  is  a 
nice,  attractive  touch. 

The  QUIK' KEY  is  connected 
the  same  as  other  paddles  and 
works  with  any  keyer,  including 
iambic  ones.  If  you've  been  us- 
ing a  bug  or  conventional  keyer 
paddle^  you  may  find  that  it 
takes  a  white  to  get  used  to  us- 
ing the  QUIK-KEY  because  of 
the  vertical  movement  of  the 
keying  levers.  Once  you  do 
make  the  transition,  though, 
you'll  undoubtedly  be  im- 
pressed by  its  operation.  And  if 
you  go  directly  from  using  a 
straight  key  to  the  QUIK-KEY, 
chances  are  you'll  wonder  why 
you  didn't  switch  sooner.  Ten- 
sion and  finger  spacing  are  ad- 
justable. 

Of  course,  some  operating 
surfaces  will  provide  better 
adhesion  than  others,  but  in  us- 
ing  the  QUIK-KEY  on  a  variety 
of  surfaces  it  was  always  much 
more  stable  than  either  of  my 
conventional  keyer  paddies, 
mostly  by  the  proverbial  coun- 
try mile. 

The  QUIK-KEY  may  be 
ordered  direct  for  $39.95  plus 
$2  postage.  QUIK-KEY,  PO  Box 


ir^lio   ni 


The  now  8046  28-pin  CMOS  IC  from  Curtis. 


73,  Katonah  NY  10536.  Reader 
Service  number  06. 

Morgan  W.  Godwin  W4WFL 
Peterborough  NH 

StNQLE  IC  SPEAKS 

RANDOM  MORSE 
Using  the  new  Curtis  8046 
28-pin  CMOS  QSLl  (Quite  Large 
Scale  integration)  \C,  you  can 
construct  a  random  Morse 
code  practice  generator  with 
features  similar  to  the  popular 
IK-440A  Instructokeyer. 

The  8047  requires  one  exter- 
nal 256  X  4  ROM  (Read  Only 
Memory)    and    an    8043-   or 


8044'based  keyer  to  provide 
completely  random  Morse 
characters  for  speed  improve- 
ment practice  from  6  to  50 
wpm.  Output  is  either  alphabet- 
only  (Novice  practice)  or 
alphanumeric  with  punctua- 
tion. A  typical  sequence  might 
look  like  this:  "0,  TSA  LVT- 

bevylz;aee73d;^ 

Variable  extended  spacing 
between  letters  and  fetter 
groups  is  also  provided  for  slow 
speed  study  (characters  at  13 
wpm,  words  at  6  wpm,  for  ex- 

Continued  on  page  158 


147 


whither  Microcomputers? 


a  pro  looks  ahead 


Chariene  Bath  Kmdie  WB2HJD 

316  Vanderbili  Parkway 
DixHiUs  NY  11746 


Computers  are  definite- 
ly the  wave  of  the 
future.  So  says  Hans 
Napfel  WB2ZZB,  who 
should  know.  Not  only 
does  he  work  with  them  at 
Fairchild,  where  he  over- 
sees 28  people,  most  of 
whom  are  engineers,  but  he 
also  has  been  studying 
them  since  the  early  60s  at 
home,  through  all  stages  of 
their  development.  And  he 
knows  what  applications 
are  planned  for  them  in  the 
foreseeable  future.  No 
one,  he  says,  can  be  unaf- 
fected by  computers.  They 
are   a   part   of   everyone's 


life,   and   this  will   be   in- 
creasingly true, 

Hans  designed  and  built 
a  small  "dedicated"  com- 
puter (one  restricted  to  per- 
forming  certain  functions) 
in  1973  It  was  built  with 
the  best  components 
available  at  the  time- 
resistors,  transistors, 
capacitors,  and  some  in- 
tegrated circuits  — and  had 
no  microprocessor  (a  group 
of  integrated  circuits 
formed  into  a  single  com- 
ponent). But  most  amateur 
computing  did  not  really 
begin  until  more  than  a 
year  later,  when  8008s  — the 
first  microprocessing 
chips  — appeared  on  the 
market.  Now  amateur  com- 
puting is  a  rapidly-growing 
hobby,  one  which  Hans 
nevertheless  believes  is 
still  in  its  infancy-  (The  fact 


im 


A  commercial  microprocessor.  This  type  of  simple  com- 
puter will  soon  monitor  the  condition  of  your  car. 


that  the  "Personal  Com- 
puting '77  Trade  Fair"  at 
Atlanta  drew  140  ex- 
htbttors  and  more  than 
5,000  people  on  its  first  day 
bears  this  out.) 

The  personal  computer 
is  industry's  answer  to  the 
general  demand  for  in- 
volvement with  com- 
puters. It  is  diminutive  in 
size,  can  read  from 
already-prepared  tapes  to 
carry  out  a  program,  or  the 
operator  can  write  in  his  or 
her  own  programs. 

Technical  people  will 
find  computers  extremely 
useful  as  a  tool,  Hans 
believes.  Indeed,  it  was 
Hans's  technical  needs  as  a 
radio  amateur  that  created 
his   interest   in   computers 


and  caused  him  to  begin 
working  with  them.  ''Now/' 
Hans  says,  'my  computer 
runs  my  radio  station/'  Not 

the  limited-function  com- 
puter of  1973,  but  a  second 
model,  built  in  1975,  which 
Hans  affectionately  calls 
"The  Blue  Max."  It  is  a 
general  computer,  pro- 
grammable for  many 
things.  The  Blue  Max 
(which  is  named  for  its  at- 
tractive azure  front  panel) 
takes  up  less  than  a  square 
foot  of  space  (quite  a  con- 
trast from  the  behemoths 
of  the  sixties,  which  were 
also  awkward  to  use).  Max 
can  provide  automatic- 
repeat  CW  when  Hans 
wants  to  run  a  test.  It 
makes    contact    with    a 


Inside  "The  Blue  Max. 


## 


3  148 


The  uncompleted  new  computer,  contain mg  $2000  worth 
of  modified  commerical  boards. 


friend  on  schedule,  with  or 
without  Hans's  presence, 
and  records  the  Morse 
code  answer  received, 
which  it  prints,  in  words, 
either  on  the  attachable 
television  screen  or  by 
radioteletvpe,  or  both,  as 
Hans  has  instructed  ft 
prints  the  received 
message  at  exactly  the 
same  speed  as  the  sender 
gives  it. 

Hans's  computer  is 
helpful  to  him  in  other 
ways  with  amateur  radio  It 
keeps  track  of  his  QSLs  for 
him  so  that  he  does  not 
have  to  wonder  whether 
the  contact  he's  just  made 
should  be  asked  for  one.  (A 
bulging  QSL  file  shows 
why  this  is  helpful!)  It 
keeps  track  of  call- letter 
changes.  And  it  can  be 
asked  to  print  out  all  the 
"Charlies/'  all  the  W5s.  or 
whatever. 

Indeed,  with  a  capability 
of  handling  200,000  full  in- 
structions (not  bits)  per  sec- 
ond  (yes,  that's  per 
second),  Hans's  computer 
can  be  asked  to  remember 
anything  Hans  uses  it  dur- 
ing contests  to  keep  his  log 
and  to  eliminate  duplica- 
tions in  the  log,  "It  is 
also  useful  for  field  days," 


he  says,  ''to  keep  you 
from  repeating  stations 
worked/' 

Hans  also  recommends 
computers  as  a  good  way 
to  practice  Morse  code. 
For  not  only  does  the  com- 
puter send  perfect  code 
every  time,  at  whatever 
speed  you  desire,  but  it 
also  can  show  you  the  dots 
and  dashes  on  screen 
simultaneously,  thus  giving 
you  the  benefit  of  involv- 
ing two  senses  instead  of 
jyst  one.  And  it  can  be  pro- 
grammed to  increase  the 
speed  gradually,  if  you 
wish. 

There  are  other  in- 
teresting computer  ap- 
plications for  the  radio 
amateur.  For  instance,  the 
moonbouncer  will  find  it 
"indispensable/'  Hans 
says,  to  keep  the  antenna 
positioned  at  the  moon. 
When  a  ham  with  a 
parabolic  dish  is  not  at 
home,  a  computer  can 
sense  the  weather  and 
wind  and  rotate  the  dish 
for  the  least  amount  of 
wind  resistance. 

Hans  and  three  of  his 
friends  are  working  on  an 
even  better  computer  than 
The  Blue  Max.  It,  too,  is 
homemade,    but    is    corn- 


Hans 's  computer  terminal  Model  33  ASR  punches  out  a 

taped  program. 


posed  of  commercial 
boards  that  the  four  men 
have  modified.  (For  Max, 
Hans  designed  even  the 
routine  things.)  Hans  and 
his  friends  are  taking  care 
to  program  their  com- 
puters the  same  way  and 
with  the  same  language 
(they  have  settled  on 
"super  BASIC"),  so  that 
they  can  exchange  pro- 
grams and  communicate 
with  each  other  effective- 
ly. The  computers  can  use 
audio  cassettes  as  well  as 
paper  tape.  Punch  cards, 
Hans  says,  are  almost  ob- 
solete in  personal  com- 
puting. (In  addition  to 
paper  tape  and  punch 
cards,  Hans's  computer 
can  work  from  a  ''floppy 
disk/'  with  the  addition  of 
a  floppy  bit  memory  unit. 
This  attachment  records  in- 
formation on  a  flexible 
record  called  a  "floppy 
disk/'  and  thus  gives  Hans 
quick  access  to  what  is 
now  peripheral-memory 
material,  freeing  space  in 
the  computer's  central 
memory.  These  disks,  too, 
are  transferable  — easily 
mailed.) 

When  this  system  is  com- 
plete, Hans  says,  it  wilt  not 
only  run  his  radio  station, 
but  his  whole  house  as 
well.   Already,    Max   orga- 


nizes important  dates  for 
him.  It  tells  him  when  to 
pay  certain  bills;  it  will 
monitor  the  water 
temperature  and  control 
the  pump  and  filter  of  his 
in-ground  backyard  pool;  it 
tells  him  when  to  send 
birthday  and  anniversary 
cards  and  when  to  buy 
gifts.  How  does  it  do  this? 
Not  by  waiting  for  Hans  to 
call  up  its  memory.  When 
Hans  looks  i*to  his 
conveniently-located  ham 
room  each  morning,  there 
is  the  day's  message  right 
on  the  screen  — blinking  to 
get  his  attention. 

"A  computer  can  handle 
anything  to  do  with 
numbers,"  Hans  says.  ''Us- 
ing it  unclutters  your 
memory  and  makes  life 
easier."  Indeed.  If  Hans 
should  be  late  for  a  class  or 
fail  to  acknowledge  an  oc- 
casion, it  will  not  be 
because  he  was  not  in* 
formed!  Max  lets  him  know 
the  flagging  date  — the  day 
it  is  necessary  to  know  — if 
an  event  is  coming  up.  And 
Hans  can  call  for  a  revfew 
of  the  coming  month,  if  he 
so  desires. 

The  computer  is  also 
useful  as  a  telephone  direc- 
tory. It  may  take  a  few 
hours  to  prepare  the  pro- 
gram, but  to  update  it  later 

149  ]m 


As  Han^  taps  out  instructions,  they  appear  on  the  screen  at  the  top  of  the  rack. 
Simultaneously,  the  Teletype^^  machine  on  the  left  makes  a  printout. 


will  only  take  seconds.  And 
you  can  get  the  number  by 
first  name  only,  last  name 
only,  or  even  by  call  let- 
ters. 

Having  a  computer  in 
the  home  can  be  beneficial 
to  non-hams,  too.  Hans's 
twelve-year-old  daughter, 
Claudia,  uses  it  for  games, 
for  educational  math 
workouts,  and  to  make 
musical  programs  She  will 
soon  have  a  remote  ter* 
minal  in  her  room-  There  is 
already  a  remote  unit  in 
the  kitchen,  where  Hans's 
Wife,  Lisa,  bones  up  on  her 
French. 

But  the  computer  can  do 
more.  It  can  adjust  the 
thermostat  in  the  house, 
for  instance.  It  could  even 
be  made  to  do  this  "in- 
telligently/' by  monitoring 
the  outside  and  inside 
temperatures  and  'de- 
ciding" how  to  adjust  the 
inside  accordingly.  This 
could  be  important  when 
one  is  away,  especially  in 
winter  when  pipes  could 
freeze,  but  when  an  Indian 
summer    could    allow    a 


lower-than-usual  inside 
temperature.  The  com- 
puter could  also  be  made 
to  turn  lights  on  and  off, 
water  plants,  feed  the  dog, 
piay  music,  and  control  air 
conditioning. 

The  family  car  will  not 
be  unaffected  by  com- 
puters. 'In  the  next  two 
years,"  Hans  says,  "cars 
will  have  computers  to 
control  gas  mileage  (by 
noting  speed  vs.  vacuum 
vs.  temperature  and  keep- 
ing the  car  running  at  max- 
imum efficiency  by  op- 
timizing the  fuel  mixture) 
and  to  monitor  the  condi- 
tion of  the  car  (letting  you 
know  if  a  light  is  not  work- 
ing, for  instance).  In  fact,  3 
few  cars  even  have  com- 
puters now/'  Signals  to  the 
driver  will  be  shown  on  one 
light-emitting-diode  dis- 
play, not  by  means  of  six  or 
eight  meters  as  we  now 
often  see  in  a  car,  A 
computer-controlled  warn- 
ing system  will  sound  a 
buzzer  to  alert  a  speeding 
or  sleeping  driver  {erratic 
wheel  movements  will  in- 


dicate  that  the  car  has  left 
the  pavement). 

Computers  will  even- 
tually revolutionize  gro- 
cery shopping.  One  could 
make  selections  at  home, 
visually  (even  comparing 
prices  from  store  to  store. 
right  at  your  own  kitchen 
terminal),  and  then  go  to 
the  store  to  pick  up  the 
waiting  order  Or  it  could 
be  delivered  to  your  door. 
Food,  by  this  system,  could 
be  dispensed  directly  from 
warehouses.  And  com- 
puters (microprocessors) 
already  control  microwave 
ovens  and  teaching  ma* 
chines. 

But  computers  will 
never  make  it  big  in  the 
classroom,  Hans  feels, 
because  ''teachers  are  too 
threatened  by  machines. 
Machines  are  potentially 
author ity^shattering.  What 
if  something  goes  wrong 
that  the  teacher  can't  fix?" 
Still,  Hans  feels  that  com- 
puters could  be  used  by 
schools  successfully  as 
tutors  for  drill  and  routine 
work,  if  they  are  housed  in 


a  separate  room  overseen 
by  a  competent  technician. 
"But  they  will  never 
replace  teachers,"  he  says. 

For  handicapped  peo- 
pie,  they  will  be  especially 
important,  Hans  says, 
becoming  the  ears  of  deaf 
people  and  eyes  of  the 
blind.  Already,  speaking 
computers  like  the  one 
owned  by  Pete  Motyl 
K1PXE  can  be  purchased. 
And  in  the  health  field, 
they  are  already  indispens* 
able,  but  will  become  more 
so. 

"And  by  1985  or  1990, 
every  house  will  have  its 
own  minicomputer/'  Hans 
says.  It  will  be  used  as  an 
"intelligent"  security 
system  (those  who  live  in 
each  house  will  not  set  off 
the  alarm),  as  a  telephone 
answering  service  and 
directory  (indeed,  alt  forms 
of  paper  directories  may 
soon  be  obsolete),  as  well 
as  for  energy  management, 
bookkeeping,  scheduling, 
providing  educational 
drill,  and  playing  games 

"What  about  using  them 
to  communicate  with  outer 
space?"  I  asked  Hans, 

His  eyes  twinkled  at  the 
unexpected  thought, 

"They  would  be  essen* 
tial  in  a  space  colony,"  he 
answered,  "to  monitor  the 
station's  life-support 
system  and  relative  posi- 
tions, and  to  keep  track  of 
supplies.  But  to  com- 
municate with  other  in- 
telligences in  outer  space? 
Let  me  put  it  this  way;  I'm  a 
hardware  realist/' 

For  Hans,  thafs  not  a 
limitation.  "I  keep  up  with 
what's  being  discovered/' 
he  says,  "and  1  just  take  it 
one  step  further.  That's 
what  makes  the  dif- 
ference/' In  fact,  Hans  ad- 
vances the  state  of  com- 
puter art  through  his  hob- 
by, then  takes  his 
knowledge  to  the  job, 
where  he  educates  others- 

In  a  pursuit  requiring 
perseverance  and  thor- 
oughness, Hans's  phi- 
losophy is  clearly  the  one 
that  works  H 


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SSTV  Meets  SWTPC:  Part  2 


micro-enhanced  pictures 


Clayfnft  W  Ahrams  K6AFP 
1758  ComsiQck  Lane 
San  Jose  CA  95124 


In  the  first  part  of  my 
article,  I  acquainted  you 
with  the  hardware  PinA  the 
basic  concepts.  Now,  let's 
discuss  the  software, 

The  'loftware  was  the 
most  complex  part  of  the 
project  hut  the  most  fun.  I 
think  the  most  important 
point  I  should  make  is  that 
the  software  i*t  a  replace- 


ment for  hardware  logic. 
The  use  of  software  is  more 
repeatable  and  reliable 
than  hardware  logic. 

Another  point  is  that  the 
timings  are  very  rritiral,  If 
yon  try  to  execute  thjQ  pro- 
gram  op  another  6800  sys- 
tem without  a  17971  MHz 
clock  crystal,  changes  will 
have  to  be  made  I  will 
identify  the  memory  loca- 
tions which  will  have  to  be 
altered  If  the  clock  is 
much  slower  than  the 
SWTPC    the  program  may 


KNHIINCB   ••TU    PKOCRAH 


NKCATXWK 


M 


TRANSH I T 

HOIS 
PRIN 


THIS    ROUT  IKE     3 
PROGIMH    CHHAHCCnCNT 


not  work. 

The    programming    was 
written  with  a  top-down  ap- 

proach,  with  the  extensive 
use  of  subroutine  calls  (J  SR 
and  BSRl  The  frequent  use 
of  up  to  4  nested  subrou- 
tines  was  used  This 
makes  the  program  easier 
to  write,  debug,  and 
r-hange  Additionally,  self- 
modifying code  was  used. 
If  you  plan  to  install  this 
prngram  on  PROM,  don't— 
unless  you  plan  to  execute 
it  elsewhere  in  RAM  mem- 


THE  8STU 
OPTIONS 


M 


ory.  Selfmodifying  code 
means  that  as  the  program 
executes,  it  changes  ftself 
This  type  of  code  is  dif- 
f  icult  to  debug,  but  the  end 
result  is  that  a  program  can 
be  written  to  run  in  less 
memory  All  subroutines 
using  self-modifying  rode 
restore  themselves  upon 
completion.  So  don't  hit 
reset  in  the  middle  of  an 
operation  unless  vou  are 
willing  to  reload  the  pro- 
gram 

Another  concept  used  is 
to  call  certain  routines  fre- 
quently. This  also  makes 
sense  and  saves  memory  A 
typical  routine  called  fre- 
quently is  DEL2  which  is  a 
program  delay  whirh  is 
used  to  transmit  pixels.  A 
few  large  blocks  of 
memory  were  left  free  for 
expansion.  Fig  1  shows 
how  memory  is  organised 
Locations  below  address 
101  were  left  free  because 
of  the  d inert  addressing 
capability  of  the  6flOO.  This 
could  be  very  useful  in 
future  enhancements, 

I  wil!  discuss  each  of 
these  routines  or\  an  in- 
dividual basis,  and  explain 
how  the  algorithms  work 
But  first,  a  few  basic  ron- 
cepts  should  be  discussed 


152 


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fig.     J.    SSrV    program 
memory  map. 

Programming  Concepts 

The  most  important  con- 
cept to  understand  is  the 
programming  format  of  the 
analog  interfale.  Fig.  2 
shows  the  bit  structore  of 
the  PIA  ports,  and  which 
bits  are  used  to  control 
various  functions.  As  you 
can  see  from  the  format, 
the  program  will  only  func- 
tion properly  with  the  hard- 
ware connected  to  correct 
PIA  bits  is  shown  in  Fig,  2. 
The  other  concept  which 
must  be  understood  is  the 
format  of  the  pixels  in 
memory.  These  concepts 
are  used  throughout  the 
subroutine  descriptions 
and  must  be  understood  to 
code  the  program  in 
another  language. 


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Subrouline  Descriptions 

The  following  is  a 
description  of  each  major 
subroutine  used  The 
routines  will  be  referred  to 
by  their  program  labeL 

Test 

This  routine  is  by  far  the 
easiest  to  understand.  This 
routine  can  be  used  by 
entering  an  analog  input  in- 
to the  special  analog  card. 


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If  you  apply  0  volts  and  hit 
a  number  key  on  the  com- 
puter keyboard,  a  zero 
should  appear  on  the  TV 
screen.  Also,  an  SSTV  fre- 
quency of  1500  Hz  should 
be  generated.  If  4.9  volts  is 
applied  to  the  card,  an  F 
will  appear  on  the  TV 
screen,  and  a  2300  Hz  fre- 
quency will  be  generated 
when  a  number  key  is 
pressed.  If  a  nonnumeric 
key  is  pressed,  the  program 
will  return  to  the  monitor. 
The  flowchart  for  this 
routine  is  shown  in  Fig.  3, 

PPRIN 

This  routine  prints  an 
ASCII  character  picture  of 
the  pixels  in  computer 
memory.  The  program  is 
written  for  the  SWTPC 
PR-40  printer  This  printer 
has  only  40  columns.  In 
order  to  print  a  complete 
SSTV  picture,  120  columns 
were  printed  on  three 
pages,  and  every  other  line 
(64).  When  these  three 
pages  are  joined  together, 
a  complete  picture  was 
formed,  A  total  of  7 
characters  was  printed, 
which  represent  the  16 
gray  levels  of  a  picture.  I'm 
sure  the  character  selec- 
tion can  be  improved 
upon.  The  selection  was 
subjectively  chosen,  with 
little  experimentation.  One 
point  was  clear:  A  char- 
acter for  each  gray  level 
was  not  the  way  to  go.  This 
technique  produced  poor 
picture  quality.  Fig.  4 
shows  a  flowchart  of 
PPRIN.  Table  1  IS  a  list  of 
gray  level  vs.  character  and 
memory  location.  This 
table  allows  the  user  to  ex* 
periment  with  the  various 
ASCII  codes. 

TRANS 

This  routine  is  used 
throughout  the  program  to 
transmit  regular  and  en- 
hanced SSTV  pictures.  The 
routine  is  easy  to  use.  Once 
selected,  a  message  ap- 
pears on  the  screen  which 
asks  for  a  keyboard 
response  of  0  to  F,  where  1 
to  F  will  be  the  number  of 


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Fig.  2.  SSJy  enhancement  program  programmmg  format 


pictures  transmitted.  If  0  is 
selected,  the  picture  men>- 
ory  buffer  will  be  filled  with 
a  gray-scale  pattern  of  16 
gray  levels  These  gray 
levels  will  appear  as  ver- 
tical bars  on  the  SSTV 
monitor.  This  allows  the 
receiver  to  adiust  his  con- 
trast and  brightness.  After 
memory  is  loaded,  the  next 
message  asks  for  the  num- 
ber of  loops  for  the  trans- 
mission. The  response 
should  be  1  to  F,  where  F  is 
15.  This  routine  assumes 
the  60-Hz  SSTV  video  will 
be  transmitted.  For  those 
of  you  who  wish  to  trans- 
mit 50-Hz  video,  the  delay 
constant  at  location  01 C9 
should  be  changed  from  20 
hex  to  10  hex. 

This  routine  uses  self- 
modifying code,  and  six 
NOP  instructions  were 
assembled  into  the  pro- 
gram. These  NOP  are 
modified  by  other  routines 
to  enhance  pixels  and 
allow  a  minimum  duplica- 
tion of  code.  Fig,  5  shows  a 
flowchart  of  the  most  im- 
portant transmit  routine,  A 
total  of  7  subroutines  are 
used  during  the  transmis- 


sion of  a  picture 

RECVPX 

This  routine  receives 
slow  scan  pictures  pixels 
and  places  them  into  mem- 
ory. The  routine  is  simple 
to  use.  Once  the  option  is 
selected,  the  first  message 
which  appears  on  the 
screen  asks  if  you  wish  to 


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fig.  3.  TEST  routine.  Test 
analog  card  rouiirte 
flowchart. 


Memory 

ASCfl 

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Gray 

Location 

Code 

Character 

Level 

231,2 

23  23 

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space 

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Table  t  Cray  level  vs.  ASCII  character  value. 


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fig.  4.  PPRiN  routine.  Print 
a  SSTV  picture  flowchart: 
CNT  2  =  pixel  counter  and 
CNT  7  =  line  counter. 


receive  50-  or  60-Hz  video. 
Your  response  should  be  50 
or  60  Upon  the  detection 
of  a  vertical  sync  pulse  by 
the  program,  the  8K  of 
memory  will  be  loaded 
with  16k  pixels  in  8.3 
seconds.  One  point  should 
be  noted:  The  program 
assumes  that  128  Unes  will 
be  received  If  the  picture 
received  has  less,  the  pro- 
gram will  continue  to  re- 
ceive video  until  memory 
is  filled.  Therefore,  part  of 

the  top  of  the  next  picture 

\  "*'^''  /       will   be  in  memory  if  the 

^ '        original    picture    has    less 

than  128  lines. 

Fig.  6  shows  the  main 
receive  routine.  This  func- 
tion is  easily  accomplished 
by  modifying  the  code  in 
TRANS  to  execute  a  Vs 
complement  of  each  pixel 
before  it  is  transmitted. 
The  transmit  routine  is 
then  executed  and  nega- 
tive pictures  are  produced. 


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fig,  5.  TRANS  routine.  Transmit  a  SSTV  picture  flowchart: 
CNT8  =  pixel  count  (64)  and  CNT  9  =  line  count  (128). 


Upon  completion  of  this 
routine,  the  code  is 
restored  to  NOPs  in 
TRANS.  As  a  result,  the  pic- 
ture in  computer  memory 
is  not  altered. 

BIN 

This  routine  produces 
binary  pictures.  Binary  pic- 
tures are  a  reduction  of  the 
16  gray  levels  pixels  to  2  If 
the  pixel  in  memory  is  8  or 
higher,  an  F  gray  level  is 
transmitted.  If  the  level  is  7 
or  lower,  a  0  is  transmitted. 
The  routine  like  BIN  modi- 
fies the  code  in  TRANS  to 
jump  out  of  the  routine, 
modify  the  pixel  to  0  or  F, 
and  transmit  it.  The  code  is 
restored  after  execution  to 
NOPs.  If  you  wish  to  ex- 
periment with  the  gray 
level  clip  level,  the  code  at 
locations  04D8,E7  can  be 
changed  from  80  to 
another  value.  Computer 
memory  is  not  altered  by 
the  use  of  this  routine. 

In  both  BIN  and  NEC, 
the  program  asks  for  the 
number  of  picture  loops 
between  1  and  F.  If  you  re- 
spond with  a  zero,  the  pro- 
gram will  loop  255  times. 
To  recover  from  this  condi- 
tion, hit  reset  and  load  a 
low  ASCII  number  into 
CNT  10  (02F4].  Then  type 
G,  and  the  program  will 
return  after  the  count  you 
have  just  entered  is 
decremented  to  zero. 

ZOOM 

Zoom  was  one  of  the 
most  interesting  routines 
to  code.  This  routine 
allows  selection  of  5  loca- 
tions of  the  picture  which 
wilt  be  magnified  by  a  fac- 
tor of  2.  The  locations  are 
selected  by  answering  a  TV 
message  with  the  com- 
puter keyboard  by  select- 
ing  0  to  4.  This  zoom 
capability  allows  magnifi- 
cation of  any  portion  of  the 
SSTV  picture  without  the 
use  of  complex  hardware 
which  is  used  in  commer- 
cial systems.  The  zoom 
locations  on  the  picture 
are  selected  in  the  program 
by    loading    the    index 


register  with  the  upper  left 
hand  corner  pixel  address 
and  branching  to  the  TRZ 
routine  (056D).  The  follow- 
ing demonstrates  how  it 
works: 


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As  you  can  see,  all  that  is 
required  is  to  transmit  each 
pixel  twice  and  then  trans- 
mit the  same  pixel  line  in 
memory  again.  The  resuU 
tant  picture  shows  con- 
touring, but  this  can  be  ex- 
pected. 

The  memory  locations, 
picture  locations,  and  hex- 
adecimal  values  are  listed 
in  Table  2,  By  simple  pro- 
gram changes,  you  can  ex- 
periment on  where  you 
would  like  to  zoom  in  on 
the  picture.  This  routine 
calls  six  oilier  routines,  and 
Fig.  7  shows  the  TRZ  rou- 
tine which  is  the  main 
routine.  Computer  mem- 
ory is  not  altered  as  a  result 
of  execution  of  this 
routine. 

CONT 

CONT  is  a  routine  which 
adds  contrast  to  the  SSTV 
picture.  The  routine  func- 
tions best  when  the  picture 
is  very  dark  and  contains 
few  white  areas.  The  rou- 
tine makes  the  picture 
lighter,  and  if  a  high- 
contrast  enhancement  is 
selected,  a  binary  effect 
will  be  achieved. 

When  the  routine  is 
selected,  the  first  selection 
will  be  the  number  of 
transmit  loops  after 
enhancement.  After  this 
selection,  the  number  of 
times  of  enhancement  is 
selected  [2  to  F),  Fig  8 
illustrates  the  computer 
algorithm  used  The 
routine  first  finds  the 
darkest  pixel  value  in  a 
routine  called  FIND.  This 
routine  scans  10  lines  in  the 
center  of  the  picture  for 
the  darkest  pixel  value  The 

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frg.  6,  RtCVPX  routine.  Receive  an  SSTV  picture  flowchart: 
CNT  3  =  pixel  count 


dark  routine  then  subtracts 
this  value  from  almost  all 
of  the  16k  pixels  in  memory 
along  with  multtplying 
the  results  by  the  enhance- 
ment number  selected 
This  new  value  is  com- 
pared to  see  if  it  is  greater 
than  F.  If  so,  an  F  is  placed 
in  memory.  If  it  is  less  than 
F,  the  results  are  placed  in 
memory. 

The  bottom  8  lines  of  the 
picture  are  not  enhanced, 


and  since  many  pictures 
are  generated  by  scan  con- 
verters, this  area  was  left 
alone  Fig.  9  is  a  flowchart 
of  the  dark  routine  which 
shows  how  some  of  the 
calculations  are  made. 

NOISE 

This    routine    removes 

random  noise  from  the 
SSTV  picture  received. 
This  is  accomplished  by  an 
averaging   technique.    Pix- 


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Fig.  7.  ZOOM  Routine.  Transmit  a  55  TV  picture  with  a2  X 

magnification  flowchart:  CNT 8  =  64  lines/picture,  CNT  9 
=  32  bytes/pictufe  tine,  CNT  12  -  tine  count  storage,  and 
CNT  11  =  index  register  storage. 

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fig.  8.  i.nhancement  selection. 


els,  as  received  by  the 
microprocessor,  are  aver- 
aged together  with  those  in 
memory.  By  use  of  this 
technique,  random  noise 
can  be  reduced  by  the 
square  root  of  number  of 
pictures  received.  When 
executed,  this  routine  asks 
first  for  the  number  of 
noise  pictures  to  be  re- 
ceived. A  value  of  1  to  F 
can  be  selected  The  pro- 
gram will  then  ask  for  a 
selection  of  50-  or  60- Hz 
video.  The  response  to  the 
query  should  be  50  or  60, 

This  routine  also  calls  4 
other  routines  and  the 
main  line  routine  is  con- 
tained in  Fig.  10.  This 
routine  is  similar  to 
RECVPX  in  operation,  ex- 
cept for  the  averaging 
routines  Since  more  com- 
puter overhead  is  used,  dif- 
ferent delay  constants 
were  selected 

MONIT 

This  routine  is  used  to 
select  the  program  options. 
Upon  completion  of  each 
routine,  the  program  jumps 
back  into  MONIT.  The  pro- 


gram should  be  started  at 
the  beginning  of  this 
routine  (OFOI),  This  is  ac- 
complished by  loading 
A048,9  with  0F01  and  typ- 
ing G,  When  this  is  done,  a 
menu  will  appear  on  the 
TV  screen,  The  routine 
calls  INIT  (01 B6}  initializes 


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Tig.  9.  DARK  Routine. 
Calculate  a  new  pixel  con- 
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fig.  70,  NOISE  Routine.  Receive  successive  SSTV  pictures 
and  average  flowchart  CNT  3  =  pixel  counter:  *Value 
was  fine-tuned  due  to  progran]  overhead. 


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the  PIA.  The  PIA  must  be 
tTiitialized  tor  the  analog 
card  to  function  properly 

Program  Delay  Cunstanta^ 

As  discussed  edrliei.  if  a 
different  CPU  clock  speed 


is  used,  different  progtdin 
delay  curistdiitb  should  be 
used  These  constants  are 
as  shown  in  Fable  3 

These    program    con 
stants  are  exactly  like  hard- 
ware   timers    and    snigle- 


shots  I  selected  them  by 
trial  arid  eirur.  I  luadt'd  a 
number  into  thern  and  then 
vie^ved  an  SSlV  picture 
The  number  was  then  tuie 
tuned  for  the  best  picture 
quality 


Keyboard 

bntry 

Me 

niory  Loca 

tian 

Value  (IME) 

Location 

0 

0526.7 

1000 

upper  l/h  cornel 

1 

052b  C 

1020 

up  pet  r/h  cornei 

2 

0530, 1 

1810 

centei 

3 

0536,6 

2U00 

lower  \th  cornei 

4 

053A,a 

201 F 

iower  r/h  corner 

Table  Z  Memory  locations  vs.  picture  locations. 


MIKBUG  Considei^atiuns 

The    program    dsj*umes 
that  MIKBUC  will  be  used. 
The    following    MiKBUG 
routines      were      used 
throughout  the  program. 
E07fc  — Output    an 
ASCI!       character 
StriiTg 

El  Dl— Output   one 
ASCII  character 
El  AC  "  I  nput    one 
ASCII  chaiacter 
The  prog  rani  also  assumes 
the  special  Analog  Card  is 

157  yj 


plugged  into  the  Mother 
Board  at  address  B010  in 
the  SWTPC  MP-68.  The  pro- 
gram address  assigned  to 
the  printer  is  8018  (loca- 
tions 02C3,  4  and  02 DO,  1]- 
A  fully-commented  source 
listing  of  my  program  is  so 
large  that  I  could  not  ex- 
pect it  to  be  published.  If 
you  wish  a  copy,  send  me 
$8.00  to  cover  the  repro- 
duction and  mailing  costs. 
If  you  are  outside  the  USA, 
please     include     more 


postage  for  airmail,  Also,  if 
you  decide  to  write,  please 
include  a  SASE. 

Acknowledgements 

I  would  tike  to  thank 
Mike  Talent  W6MXV  for 
his  help  in  interfacing  the 
MXV^IOO  SSTV  monitor 
and  for  his  technical 
review  of  my  project.  Addi- 
tionally, I  would  like  to 
thank  M.  S.  Schlosser,  Vice 
President  of  Spatial  Data 
Systems    for    providing    a 


copy  of  his  Handbook  of     allowing   me   to   refer   to 
Image    Processing^    and      it  ■ 


Program 

Program 

Current 

Program 

Label 

Location 

Value 

Use 

MSEC1 

0126 

04 

ADC  conversion 

MSEC2 

01 C9 

20,10  (50  Hz) 

Transmit  delay 

PUL1 

03C5 

5D 

Horiz  pulse  width 

' — 

03E6 

IE 

Vert  pulse  width 

■^^ 

0200 

OF 

Missing  horiz  pulse 
width  delay  time 

01E0,070B 
0716 

29,20  (60  Hz) 

RECVPX  delay 

— 

0710,0716 
07E6 

18,13  (50  Hz) 

NOISE  delay 

Table  3.  Program  delay  constants. 


Nei4^  Products 


from  pagt^  M/ 

ample). 

Another  feature  is  an  analog 
output  to  directly  indicate  code 
speed  in  wpm  on  a  1  mA  move- 
ment meter. 

For  additional  information, 
write:  Curtis  Efectro  Devices, 
Inc.,  Box  4090.  Mountain  View 
CA  94040,  or  cal I  (41 5)-964'3136. 
Reader  Service  number  C90. 

HEUER INTRODUCES 

WORLD  S  SMALLEST  DIGITAL 

MULTIMETER 

Heuer  has  announced  the 
availability  of  a  microrninia- 
turized  digital  multimeter,  the 
DMM  2000,  for  industrial  field 
service  measurement  applica- 
tions. Introduced  earlier  this 
year  at  the  Newcom  78  show  in 
Las  Vegas,  the  new  instrument 
is  the  smallest,  thinnest,  most 
compact  digital  multimeter 
available  anywhere.  It  weighs 
less  than  3  ounces  (or  80 
grams),  including  probe  and 
batteries,  and  measures  100  x 


40  X  14  mm  (4"  x  1.87"  x  0.55"') 
for  the  base  unit,  and  100  x  20  x 
12  mm  (4"  x  0J8"  x  0.47")  for 
the  standard  probe. 

The  LCD  display  assures  a 
high  degree  of  legibility  for  on- 
the-job  service  for  computer 
systems,  business  machines, 
telephone  exchanges,  data 
transmission  systems,  radios, 
and  TVs.  The  mstrument  pro- 
vides four  measuring  ranges 
for  every  mode:  dc  up  to  1000 
volts  and  ac  up  to  700  volts,  ac 
and  dc  current  up  to  2  A,  and 
resistance  up  to  20  megohms, 
with  a  typical  accuracy  of  0.5% 
on  the  dc  range. 

Heuer  was  capable  of  de- 
veloping such  a  small  .multi- 
meter  because  the  company 
combined  the  microminia- 
turization used  in  its  watch 
manufacture  with  advanced 
multi-layer  ceramic  substrate 
techniques. 

Two  major  technical  features 
of  the  Heuer  multimeter  are  its 
true  rms  (root  mean  square) 
measurement  of  the  ac  range 


and  complete  shielding  against 
rf  and  other  types  of  interfer- 
ence, which  assures  accuracy 
and  error-tree  reading  even  in 
radio  and  TV  applications, 
Another  technical  feature  is  the 
special  design  of  the  probe  and 
hook  for  easy  accessibility 
while  testing  high-density  cir* 
cult  boards,  A  choice  of  ac- 
cessories, including  special 
probes  for  high  voltage,  high 
current,  and  temperature  mea- 
surement, is  also  available. 

The  exclusive  permanent 
identification  of  the  measuring 
mode  on  the  LCD  display  and 
the  remote  control  of  measur- 
ing mode  and  range  on  the 
probe  simplify  operation  of  the 
multimeter,  and  assure  error- 
free  readout  of  the  results.  Up 
to  100-hour  battery  life  is  pro- 
vided for  the  DMM  2000  by  four 
small  watch  batteries  of  1.5  V 
each.  An  additional  advantage 
of  the  unit  for  field  service  ap- 
plication Is  its  high  electronics 
reliability  and  sturdy  mechan- 
ical construction.  The  unit  is 
delivered  in  a  handsome  carry- 
ing case  which  includes 
measuring  cable,  spare  probe 
point,  batteries,  and  fuses. 

The  DMM  2000,  however,  Is 


not  designed  for  professional 
use  alone.  With  this  unit,  the 
electronics  enthusiast  has  at 
his  disposal  a  measuring  and 
servicing  instrument  which 
suits  his  requirementSp  con- 
sidering its  ease  of  operation 
and  Sturdy  construction. 

The  DMM  2000  marks  the  en- 
trance of  Heuer  into  the  field  of 
microelectronic  instrumenta- 
tion. Heuer  is  a  100-year-old 
Swiss  pioneer  in  high-precision 
chronographs,  stopwatches, 
and  electronic  timing  devices. 

For  additional  information, 
contact:  Hans  J.  Kueffer,  Heuer 
Time  &  Eiectronics,  960  South 
Springfield  Avenue,  Springfield 
NJ  07081.  Reader  Service 
number  H30. 

SD-1  TWO  TONE 
SEQUENTIAL  DECODER 

A  new  product  announced  by 
Communications  Specialists  Is 
the  SD-1  Two-Tone  Sequential 
Decoder.  This  product  is  micro- 
miniature in  size,  measuring 
just  1 .2"  X  1.67"  X  .65^^  high,  and 
will  fit  all  mobile  units  and 
most  portables, 

It  uses  plug-in  field-replace* 

Commued  on  ^ag&  204 


The  DMM  2000  multimeter  from  Heuer. 


-h 


The  SD'1  Two-Tone  Sequenttaf  Decoder  from  Communications 
SpeciaTrsts, 


M 


158 


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[5  ptmntli^ 
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TKHOBHtUI, 


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159 


A  Multi-Memory 


Morse 


ine 


using  a  Motorola  micro 


Kenneth  D.  Leinmger  WABTIW 
inOI  Puaon  Sl 
Utka  MI  48087 


This  program,  a  dual- 
function  aid  to  sending 
Morse  code,  was  written  on 
Motorola's  MEK6800D2 
evaluation  kit  Not  only  is 
the  function  useful,  but 
valuable  experience  is  to 
be  gained  in  writing  a  pro- 


Dor      ^  '    ? 


fi 


Pi  A 


i 


DftSM 


MESSA(iE    9 


-D         P- 


WtSSAGE:   4 


-c     «- 


¥ESS4fiE   a 


-fi      a- 


■«ESS4££  Z 


C^ 


-fl      s- 


■KSSAbE   I 


rt 


OOfPUT 


gram  which  exercises  the 
PIA.  (No  matter  how  large 
or  small  your  system,  you 
can't  "control  the  world" 
without  first  stirring  those 
I/O  lines  to  lifel) 

As  previously  indicated, 
this  program  does  two 
jobs:  It  emulates  the  logic 
of  an  automatic  keyer,  and 
also  allows  the  fully- 
automatic  transmission  of 
one     of     five     prepro- 


<ZI  KiVEB 


Pi- 6 


fh 


pe-4 


^B    J. 


Pb-t 


PB    I 


m 
^^ 


Kl»  ^ { 

f     WQ 


MC 


-r 


fig.  1.  Code  system  schematic  diagram. 


^ 


grammed  messages.  All 
eight  lines  on  the  "A"  side 
of  the  user's  PIA  are  uti- 
lized; two  for  the  dot  and 
dash  contacts  of  the  keyer, 
one  for  the  output  to  the 
keying-reiay  buftei,  and 
one  for  each  of  the  five 
message*select  push  but- 
tons Fig.  1  indicates  how 
simple  a  schematic  be* 
comes  once  a  micropro- 
cessor system  is  used  to 
displace  combinational 
logic. 

The  program  runs  in  the 
256  bytes  of  RAM  provided 
in  the  "barefoof '  kit,  but 


L£tTUI  "^^ 


Fig-  2.  System  initialization. 


expansion  of  the  kit  to  512 
bytes  by  adding  two  6810 
chips  in  the  sockets  pro- 
vided is  necessary  for  the 
message  buffer,  Of  course, 
one  could  utilise  the  op- 
tional HUM  areas  on  the  kit 
once  the  application  and 
messages  were  suitably 
developed 

Ifiifialization 

The  program  is  executed 
at  location  001 D  As  in- 
dicated by  Fig.  2  and  Pro- 
gram A,  the  PIA  is  con- 
figured, then  the  letter  "k" 
is  sent  to  acknowledge  a 
functioning  system  Just 
how  the  dits  and  dahs  are 
formed  will  be  discussed 
shortly.  Each  PtA  line  as- 
signed as  an  input  looks  like 
a  standard  TTL  input  com' 
plete  with  internal  pull-up 
resistof  Bit  0,  the  output 
line,  has  insufficient  power 
to  directly  drive  the  keying 
relay,  a  problem  easily 
overcome  with  the  use  of  a 
common-emitter  amplifier. 


160 


CED 


tfT; 


T|S 


XB 


H3 


JfTS 


5^^      Its 


VE5 


rts 


f>0— *■ 


tfS 


Q«— »■ 


TE5 


POINT  EFl 


SET   UA 


— ^ 


XMTT 


f /g.  3,  /npt/f  potting  routine  ftowchari. 


Qq4 


IMtlE 


fflO    B 


C^3 


QiT  tiO   Of 

ELEMENTS 


ffS 


tti ,  ^iiioii(}si>Atc 


Tl(  ,  ,  I^HCtlUf  l&lg 


LNr,RMINT 


ilT     tfST 


loi  & 


CHaBACTEff    PONE 


as* 

LHiLJirJ 


LDEJ.ATJ 


.DELAY J 


^Ei  POP  una 

F^  mitt 

CHAHAtTIJI 


fig.  4.  Morse  code  routine  flowchart. 


Character 

Code 

Character 

Code 

Character 

Code 

0 

FD 

1 

02 

AH 

55 

1 

7D 

J 

74 

Slash 

95 

2 

3D 

K 

A3 

Period* 

06 

3 

ID 

L 

44 

Period 

54 

4 

OD 

M 

C2 

Comma* 

06 

5 

05 

N 

62 

Comma 

CO 

6 

85 

0 

E3 

Question* 

06 

7 

C5 

P 

e4 

Question 

30 

S 

E5 

Q 

D4 

Wordspace 

07 

9 

F5 

R 

43 

Halt 

00 

A 

42 

S 

03 

B 

84 

T 

81 

C 

A4 

U 

23 

D 

S3 

V 

14 

E 

01 

w 

63 

F 

24 

X 

B4 

G 

C3 

Y 

94 

H 

04 

z 

C4 

r    S    5    4    3    2 


NDW   CHARACTER    IS   tMCODEO: 


I     t    0    I  |0    1    0   o| 


Cl^fAftACTER    FfELO 


NO  OF  ELEUEAITS   FIELD 


tiM  THIS  EK AMPLE.  Htn  '04'.  OH  LETTEiR  'Q'   l^    SttOltN) 


r    6    5    4    3    £ 


0    0    0    0 

Q     1      t     0 

r 

0    1    C    1 

0    10    0 

*^iiiiCTyATiOf4  ncouiit£s  Two  BTTES; 

CL£li£ifT$   BYTE 
CMARaCTEq   BYTE 


Ufi  THIS   IXAMPLE.   HEX '*065*»%  OR  "PERIOO"    IS    SHOWNI 


Fig.  5.  Digitizing  the  Morse  code. 


PIA  Polling 

This  portion  of  the  pro- 
gram, illustrated  in  Fig.  3 


and  Program  B.  reads  the 
input  lines  of  the  PI  A  (bits  1 

through    7)    and    then    se- 


"TRANSlAlf"  SuenOUTlME 


C  ■■"  ) 


Plh  BIT  Q 


ZEno 


NOt   JtPKJ 


sEwo  ftrntM 


IDEL4.TJ 


SE%0   OQiT 

^ _ 


ltCl4.¥J 


^QELAT"  &uanOUT>NE 


GiiED 


F/g.  6.  Transmit  and  delay  flowcharts. 


quentially  cornpares  the 
bit  pattern  with  each  legal 
pattern  expected:  five  pat- 
terns for  the  five  prepro* 
grammed  messages,  and 
two  for  the  keyer  input.  If 


all  inputs  remain  high,  the 
polling  routine  continuous- 
ly repeats  the  check.  If  a 
particular  message  is 
selected,  however,  the 
grounded    input    is    de- 

161  Um 


LOCAflOK 


m 
ft 

0h 

0B 
0k 

0& 
0f 


20 
22 

2K 

33 
34 


CiiSE 


1100 


USEL       SYHBOL 


I 'HE  SET 
MESSl 

ME3&3 
■ES54 
MKSS5 

BSKST 
EL&EG 


7P  8sa^5 

66  !?1 

B7  B)2f(^4 
66  04 
B7  6)2^5 
C6  ft 

5P 

|lt>  000^^ 


irrtT 


READTT 


GLR   CRA 
LM   A  ifi^i 

LDA  A  ^l^ii 
STA  A   OAA 
LDA   B  1101 
J5R  DtIT 
CLft  B 
JSH  XMIT 
I  KG   B 
JSF   TifIT 


GCMH£1VT 


POINTS  Ti)  SIAHT  OF  TfeTT  1 
POINTS  TO    START    UF   TEXT    tt 

poiri's  TQ  sTAi^T  ar  tkxt  3 

POINTS  TO  SIJ^liT  CiF  TKKT  4 
P0IHT3  Tt>  5TAUT   OK  TKXt   5 
pOUIT£fi   FOR   CUHHEUT  CHAJt 
ilT  Test  KASI^    ^tafl£  AfiEA 
SLEMSHTS   VEH  CfCAW   RKGISTEH 


GLEAI*  CHA 

BIT   0  DK    KIA    LS  OUTPUT 

SET    BIT   0  OF   DM 

SET    HIT    2 

a^LECTS  PIA  FKIilPtI  REG 

3ET   0  TO  ^1 

^KNO  UlASTJ 

CttlAH  ACS   B 

3£|tD  DOT 

SST   B  TO  1   AfJAiN 

SE«n  !>AS11 


Program  A.  System  buffers^  vectors^  and  mitialization. 


LOCATiUfl 

COTIB 
C6  PE 

LABEL 
READ 

:.YJ 

ifiOL 

comufc 

3T 

LDA 

B  nwK 

StT  HiSAIJ  fc^ASH 

39 

r4  S004 

Ami 

B  MA 

AND  riA   INtU  AC:^  B 

30 

CI   PC 

fESTl 

CBIP  fi  #«PC 

CyMFAftK    l»    Vint    'PVT* 

3E 

26  0fi 

BflE 

tfc:ST2 

IP  /,   UO  T^^;JT   ? 

4j?( 

DK  ^2 

LDX 

MJ'^iJSl 

POINT    TO   WlESSAaK   1 

42 

2^  il 

BRA 

UOJJE 

lillH   ME^SAHl': 

44 

CI   FA 

TEST  2 

GiiTF 

B  #fFA 

COKPAHE   B   WITH    *PA* 

46 

ze  0i 

BPE 

TE5T5 

IP  /t  &>  tp:st  3 

48 

BE  A 

LDX 

MEiiS2 

HJIHT  TO   HHSSA'JE   ? 

4A 

^  ^ 

BMA 

CODE 

Run  hessa:;^ 

4C 

CI  F6 

fESfl 

CKF 

B  #1F6 

CCMPAEE  B    ilTll  « F6* 

4E 

26  04 

BHE 

^£5X4 

IF  i',   DO  TEST  4 

5|f 

Q£  06 

LM 

IIE5^3 

POINT  TO  Ml-JKSAJE  3 

52 

2^  21 

BRA 

CODK 

BUW   MESiiM'ft 

54 

CI  EE 

TEST4 

CJ^ 

B  rtfSEE 

UCMPAi^E   B    (VI  Til    't^E' 

56 

26  0A 

BfiE 

TJ-.ST5 

IF  /,    Uy  TEST  5 

58 

SB  0d 

LDX 

MKSS4 

POINT    TO  WKiiSAUK   4 

5A 

20  19 

BieA 

CODE 

i(UH    tiUii^AtlE 

5C 

CI  DE 

TfiSfJ 

CBfP 

B  #SDE 

QOM'ikHK  B  *I1H   'DE* 

5E 

26  04 

ffrg 

n 

I?  ^,   I»  T&St  6 

0 

OE  0A 

LUX 

MI^C^ 

POIltT  TO   t^ES^^^AOE  S 

62 

2«0  11 

BRA 

CODE 

miir  1ESS/.GE 

64 

CI  IE 

TEST$ 

c»\F  B  i^ias 

COMPARE  B  nm  *m* 

66 

26  03 

BI:E 

TEST7 

IP  /,   m  Tli::T  7 

68 

5F 

CLR 

B 

PltEP  a   FOLt   "DIT" 

69 

BD  55 

BSR 

XIUT 

TRANSMIT  A   "DIT" 

m 

CI  7E 

fESTT 

Ck.a 

B  ffZl^ 

L^aiWIAliE   B    iVWl    '7E' 

6D 

36  C6 

m4E 

liEAB 

IF  i^,    GO  BAUK   10   Ifh^U 

6F 

5F 

CT.R 

B 

HiEl'  B   FOM    'UAH'    m^ 

7iif 

5C 

mt: 

B 

SbTTlBC^   TO  01 

71 

m  4D 

s^ 

HOT 

THAMSIOT   A    Mvt  «* 

73 

20  C2 

EHA 

READ 

go  TO  READ 

THIS   ROUriJiE   POLLS  THE  PlA    (BITS   1  TiiRU   7)   AH]> 
Bl^JTieiHffTE^   CUjJTHuL  A;i  jUjiCJiIOM  OF  uPEiWiUB 
IKHJT   TO  THE  PIA- 


Program  B.  Input  poUing  routine. 


tected,  the  index  register  is 
loaded  with  the  starting 
location  of  the  respective 
message  text,  and  then  a 
branch  to  ''CODE  '  (loca- 
tion 0075]  is  executed. 
When  the  message  is  com- 
plete, -CODE"  returns  ex- 
ecution to  the  beginning  of 
the  polfing  routine.  If  the 
keyer  is  operated,  then  the 


dot  or  dash  contact  is 
detected  and  Accumulator 
B  is  respectively  cleared  or 
set.  This  accumulator  is 
then  handed  to  the  "XMIT" 
subroutine  whose  job  it  is 
to  make  nice  clean  setf- 
completiog  dits  and  dahs. 
After  a  single  dit  or  dah,  a 
"return  from  subroutine" 
instruction   returns  execu- 


Kl 

PB'I  through 
PB-5 

01 
R1 


Parts  List 

Relay,  Sigma  65F-1A-12DC 
or  equivalent 

Switch,  push'button-type, 
NO  momentary-con lact' 

HEP  234  or  equivalent 
1k,  V4  W 


•Note:  Because  relay  is  energized  during  system  reset,  the  reiay 
output  is  taken  off  the  normally  closed  contacts. 


LOCATIOH 


75 
7? 
79 
7B 
71) 
7F 
81 
63 
65 
87 
89 
U 
Be 
BE 
90 

91 
nj 

95 
96 
98 
9B 
^D 

H 
A0 

A4 
A6 

AB 
AA 

AC 
AE 

tXp 

B2 

m 

B5 


CQBE 


lAHSi       SYMBOL 


C6  07 

CODE 

LDA   B  #$01 

EA   0 

m  0t 

AKD  1  0^pX 

STAB  ELDEC 

ca  m 

CMF  B     1^7 

27    i!& 

HEq   WHD3P 

CI  0^ 

CMP  B     $06 

27  m 

BBQ  IVMQT 

CI  m 

2s  m 

WBB  900 

BVE  CtHtT 

^" 

^A  H£AD 

RJICt 

IBX 

DF  0C 

COHT 

STI  CBHNT 

B6  6^ 
97  p: 

LDA  A  i^lBf^f 

T£ST 

STA  A   MSKST 

5F 

CLH   B 

A5  m 
27  PI 

BIT  A  0,1 

BEQ  iilJB 

5C 

UlC  B 

BD  aa 

301 

S5H   Hilt 

QEC  £LBEC 

BEQ  CHRS? 

96  0t 

LDA  A   MliKST 

44 

LER   A 

UE  0Q 

Litx  indiJ-ii' 

20  EA 

Di^■   TEtiT 

Bd  36 

#RDSP 

JjiDri  DLLAY 

BD  i4 

BSK   DtLATf 

bd  yz 

B£B  DELAY 

m  30 

C3RSP 

ESB   DKLAY 

m  ZE 

Kj\i  DHiAY 

BD  2C 

BSil  DELAr 

DE  0C 

LD3E  CflHltT 

0&  ^ 

INJt 

DF  00 

STI  CRRKT 

20  BE 

BRA  CODE 

GCM£EifF 


MASK   ACU  B 

GET    PITS  0,1, AND   Z 

SAVE  ff   OF  iiLKMENTS 

SEVH^f   ELETt"j;NT37 

IF  SO,   W   *0Ki>£FAC2 

SIX  KLEMEWTS? 

THiOi  KlRCTUAl  t;jll 

^EBO  ELES^JPTSf? 

IF  BO,   JXH1E. 

CO   back:  to  POLLIIiG 

LOOK   At  HEX'S  CHAR 

SAVE   IQINTEH 

SET   HIT  7    (MAyklUT) 

SAVE   AT   HAirKljTOHE 

GET   HEAIJY   FOB  CODE 

TEST  A«  ElrKLEHT 

IF  0,    DO  DOT,    IP  1,    DO  BASH 

PREP   "B"   FOR  CIIAR 

EXECUTE  E!*EIIH«T 

a^E  I.E£iS  ELiCMEflt 

IF  ZEm,    DO  CHAR   SPACE 

GET  MASK  BACK 

SHIFT  mi  TO  HiGirr 

GET   I'OINTKH    PACK 

GO  TO  Tl^^f 

SIX   DELAY   UIOTS 

SENT   BET#E  .]J    A'OKDS 

CALLED  BY   "^7"* 

THHEE  DELAI  DHltS 

SENT  APTEa  EACi! 

CliARACTEB 

GET  POIBTEn 

IHCHEIitKrJT  Pt/Et   NEXI 

SAVE  POIKI-EH 

GET   HACK^    DO  NEXT  CEiAR 


XBIS  BOUflirE  COItVEHTS  A  HEIABECIIIAL  E]ICOIl£II 
KRSi  HESSA0B   UrO  REAL  TIIIE  ItQUSB  Q<mE, 


Program  C  Morse  code  roc/t/ne  listing^ 


OiX^HF.^ 


LOCATION 

CDDl 

LABEL 

STfUBCL 

C0 

86  PE 

IMIT 

]Vk 

A  #*FE 

Ct 

^^ 

AMD 

A   FIA 

C5 

^lA 

A   FIA 

ce 

5D 

TSf 

B 

C9 

27  04 

mQ 

LOT 

CB 

8D  ^F 

DASH 

DSH 

DELAY 

CD 

SD  ^D 

BSR 

DKLAY 

CF 

8d  0B 

DOT 

BSR 

DIllLAY 

m 

8^  £Jl 

LDA 

A  n0i 

Dl 

BA  Bim 

ORA 

A  FIA 

Il€ 

B7  dml4 

STA 

A  riA 

D9 

8l»  ^ 

BSK 

DELAY 

QB 

39 

HTS 

DC 

BE  «l^ 

BELAY 

LBK 

PBESEt 

DE 

09 

BEO 

DEjr 

DF 

26  fD 

BKE 

DEC 

El 

39 

KES 

Program  D. 

Transmit  and  d 

ItA^   Ai    BIT  0  OFF 
AMD  FIA   into  A 
FIA  BIT  0  KPI  LOJ 
IP  ACC  B  IS  ^EHOj 
EXEClfTE   Dcrr 
CfTHER-VISE  BO  A   DASH 
U   DASH   IS  THRtK  UNITS 
LONGS    A  DOT   IS   OWE) 
SET   PlA   BIT  0  BY 
UTILIZTWO  TIIE   "OH" 
►^lKi?TM>N 

COHflETE  THE  BOT/lMlSi 
HErUaii   FH.«  5FSTilE 
rUIS   IS  Tt!E   DEUr 
SUBRUJTIWE-    VAHY  CODEB 
SPEED  W  MODIFY  INC 
X  TRKaHT  AT  LOG  00, 


tion  to  the  polling  routine. 

Digitizing  the  Morse  Code 

The  real  challenge,  of 
course,  was  to  teach  the 
machine  to  speak  ''Morse." 
Essentially,  the  system  ob- 
tains a  character  (a  byte  of 
data  from  the  message 
text)  and  performs  a  bit 
test,  starting  at  the  MSB.  A 
"1"  is  translated  into  a 
dash  and  a  "0"  into  a  dot. 
Knowledge  of  the  number 
of  dits  and  dahs  in  a  par- 
ticular Morse  character  is 
required  in  order  to  tell  the 
program  when  to  stop  shift- 
ing  the  bit  test  across  the 
data  byte.  This  is  ac- 
complished by  indicating 
the  number  of  elements  in 
the  three  least  significant 
bits  of  the  data  byte.  As 


shown  in  the  flowchart  in 

Fig.  4  and  the  listing  in  Pro- 
gram C,  the  A  and  B  Ac- 
cumulators are  masked  so 
that  Accumulator  B  re* 
ceives  the  number  of 
elements.  Accumulator  B 
is  then  stored  at  ''ELD EC/' 
a  memory  location  which 
is  decremented  every  time 
a  Morse  element  is  com- 
pleted Fig.  5  indicates  how 
the  Morse  code  is  encoded 
into  the  previously  de- 
scribed format,  As  usual, 
exceptions  exist,  and  they 
deserve  some  explanation. 
The  format  is  useful  for  a 
Morse  character  which 
contains  from  one  to  five 
elements.  Punctuation  re- 
quires special  handling. 
Therefore,  if  Accumulator 
B  picks  up  the  integer  '06/' 


M 


162 


then  that  particular  byte  is 
skipped:  The  six-bit  char- 
acter is  found  at  the  next 
location  in  the  text  Two 
other  special  cases  exist, 
one  for  inserting  just 
spaces,  and  one  for  termi- 
nating the  message.  These 
sttuatrons.  again  detected 
in  Accumulator  B,  are  il- 
lustrated on  the  'CODE" 
flowchart. 

Morse  Code  Generation 

Subroutine  "XMIF'  (Fig. 
6  and  Program  D)  handles 
the  actual  formation  of 
and  output  for  the  dits  and 
dahs.  The  timing  for 
character  generation  is  per- 
formed by  a  delay  loop 
located  at  00 DC.  The  pre- 
set value  is  conveniently 
located  at  0000.  An  initial 
value  of  hex  1700  sets  the 
keyer  and  message 
generator  speeds  at  about 
13  wpm.  A  dot  consists  of 
one  unit  of  time  of  output 
"on"  followed  by  an  iden- 
tical unit  of  time  of  output 
"off."  A  dash  consists  of 


three  units  of  time  of  out- 
put "on''  followed  by  a 
single  unit  of  time  of  out- 
put "off/'  The  contents  of 
Accumulator  B  at  the  time 
of  the  call  indicate  the 
desired  element  (00  dot; 
01:dash),  The  output,  PI  A 
bit  0,  is  cleared  to  assert 
output  'on".  This  prevents 
a  key  down  situation  during 
system  reset. 

Setup 

Loading  the  messages 
for  the  automatic  sender 
consists  of  converting  the 
text  of  the  message  into 
hexadecimal     and   storing 


it.  (Armed  with  only  an 
evaluation  kit,  this  is  a 
manual  job!)  The  starting 
address  of  each  message  is 
then  stored  in  the  message- 
vector  area  starting  at  loca- 
tion 0002  The  current  pro- 
gram  can  only  support  five 
message  vectors,  but  there 
is  no  reason  (other  than 
memory  contraints)  why  a 
multitude  of  messages 
could  not  be  stored;  simply 
changing  a  vector  would 
then  pull  a  new  text  string 
into  the  foreground.  A 
series  of  "Vs''  or  the  word 
"test"  repeated  several 
times  makes   a   nice  brief 


message  around  which  the 
code  speed  may  be  opti- 
mized. Fig.  7  illustrates  a 
group  of  encoded  mes* 
sages. 

Operation 

Start  the  machine  by 
executing  at  001 D.  The  let- 
ter "k"  in  Morse  should 
acknowledge  start-up.  At 
this  point,  the  keyer  may 
be  used,  or  any  one  of  five 
messages  may  be  sent  by 
momentarily  depressing 
the  appropriate  push  but- 
ton. Once  started,  a  mes- 
sage will  proceed  until 
completion. ■ 


Message 

Starting  Location 

Code 

1.  CQ  CQCQ 

0100 

A4  D4  07  A4  D4  07  A4  04  07 

2.  DE  WA8TIW  K 

0109 

83  01  07  63  42  E5  81  02 

63  07  A3  00 

3.  QTH  IS  UTICA. 

0123 

D4  81 .04  07  02  03  07  23  81 

MICH.  ES  NAME 

02  A4  42  06CC  07  C2  02  A4 

IS  KEN 

04  0654  07  01  03  07  82  42  C2 
01  07  02  03  07  A3  01  82  OO 

4.  EIGHT  DJTS 

0148 

01  01  01  01  01  01  01  01  00 

5.  QRZQRZQRZ 

0151 

04  43  C4  07  D4  43  C4 
07  D4  43  C4  00 

Fig.  7.  Sample  message  set. 


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163 


"This  is  Your  Computer  Speaking'' 


how  to  dial  up  your  micro 


Completed  modem  number  one. 


^ 


164 


Jerry  Sorrels 

6266  Banner  Ct. 
Riverside  CA  92504 


A  modem,  now  that's 
what  I  need  for  my 
6800  system!  But  how 
about  one  that  has  auto 
answer?  Auto  answer  lets 
you  dial  up  your  phone, 
and,  when  it  rings,  the 
modem  will  answer  and 
connect  your  computer  to 
the  phone  line.  Now  you, 
or  someone  else,  can 
operate  your  computer 
from  a  remote  terminal 
and  modem. 

I  decided  on  using  Mo- 
torola's MC6860  modem 
IC,  and  being  a  tairly- 
stingy-with-a-buck  person, 
its  availability,  features, 
and  $14.95  price  are  what 
sold  me. 

After  spending  a  week 
thinking,  i  decided  on  the 
features  for  my  first 
modem.  It  was  going  to  do 
everything  the  chip  was 
capable  of  This  overkill 
approach  does  have  its  ad- 
vantages when  you're  not 
positive  about  what  you're 
going  to  do  with  it  or  con* 
nect  it  to. 

Two  months  later,  when 
the  smoke  finally  cleared,  I 
had  built  two  modems. 
One  was  a  do-everything, 
interface-toalmost-every- 
thing,  and  the  other  was  a 
minimum  parts  version, 
with  most  of  the  features. 

This  article  will  be  about 
a  combination  of  my  two 
moderns  which  will  have 
the  following  features: 
0-300  baud,  self-test,  full 
duplex,  originate  and 
answer  modes,  compatible 


Inside  view  of  my  fir^t  modem  {nole  ii]wrnat  caupii^r  board  mounted  ai  angle  to  tit  tn 
case). 


with  various  systems  via 
TTL  or  KS-2iJ  levels  and 
auto  answer  and  discon- 
nect My  total  cost,  for  all 
new  parts,  was  under  SJU, 
including  the  case  and 
power  supply. 

Some  Theory 

This  modem  uses  audio 
frequency  shift  keying 
(AFSK),  da  Id  to  be  sent  is 
converted  to  audio  tones. 
If  the  modem  is  in  the  orig- 
inating mode,  a  logic  0 
(space}  is  sent  as  a  1070  Hz 
tone  (2025  Hz,  if  in  answer 
mode),  and  a  logic  1  [irjark) 
is  sent  as  a  1270  Hz  tone 
(2225  Hz  if  in  answer 
mude);  see  Table  1.  This 
might  seem  a  little  confus- 
ing, but  it  works  just  fine. 
These  frequencies  are  stan- 
dard for  low-speed  data 
communication. 

This  modem  is  com- 
posed of  several  logical 
sections.  Fust  is  the  inter- 
face to  the  telephone  com- 
pany line  (see  the  sche- 
matic. Fig.  1J.  This  inter- 
fai^e  must  be  able  to  niatch 
the  characienstic  im- 
pedance of  the  phone  line, 


usually  900  Ohms,  to  tne 
modem.  It  mu^t  pic  vide  dc 
isolation  from  the  tele- 
phone line  and  tu«  auto- 
matic answei.  iTtusi  bt  able 
to  detect  when  the  phone 
Is  ringing  and  be  able  to 
answer  and  terminate  the 
calL 

The  filtei  (see  Ftg  2) 
passes  only  itit;  rrequen 
cies  1070  Hz  to  12/0  Ha 
when  in  the  dit^vvei  mode 
and  2025  Hz  to  2225  Hz 
when  in  the  uiigmaLe 
mode.  The  fikei  is  needed 
because,  in  full  dupltfx 
operation,  the  niuoem  is 
transmitting  and  receivtng 
at  the  same  tinit^,  and  the 
signals  must  be  st^paraied. 
The  limiter,  ICi,  takes  the 
sine  wave  from  the  filter 
and  changes  it  into  a  syin- 
metrical  squaie  wave  of  a 
TTL-compatible  level  The 
demodulator  in  the 
modem  IC  cQiiipaies  each 
half-cycle  of  this  square 
wave  against  the  crystal- 
control  led  tiniebdse  to 
deteitnine  if  the  ini.oming 
frequency  is  a  mark  or 
spcice.  The  Lhreshuid 
detector,  IC4,  is  used  lo  tell 


the  modem  IC  that  the  in- 
put signal  enttimg  the 
ir  miter  is  above  the 
miniHium  detectable  level 
The  bdbO  mud  em  K  is 
the  biatns  behind  the  out- 
fit H  lakes  L^are  ot  modula- 
tion deinodulatiON,  and 
the  handshaking  signals  to 
e^^-ibn^h,  iTtdintain  and 
tern^itiate  ttie  data  link 
Anothei  iectiuii  i:>  tht;  m- 
lertdi  e  to  rhe  compuiei  ot 
terminal.  There  is  a  fair 
amount  of  tlexibility  here 
due  to  the  btibO  signal 
levels  Derng  1  I  L-cumpati' 
ble  Ueptiidiug  on  the  ex- 
act use  you  plan  fui  the 
mudtriii  It  can  be  tailored 
to  fit  In  jjiy  cdse,  I  con- 
verted soiiie  of  the  signals 
to  Kb  232,  ail  OT  them 
could  be  ca*i vetted  rf 
desired 

Huw  n  Works 

It  1  IS  placed  m  the 
aiiswei  mode  when  its  pin 
19  is  grounded  This  is  done 
by  the  rin^  deiectof  when 
your  phone  rings  ui  by 
pu:>hiiig  the  an^iwej  switch 
Thi>  *  au^es  K1,  pin  4  lo  go 
high   operating  RL1.  which 

166 


TCtCPrtOME  PLUC 


fELCFMOUE 
JACK 


2N.390* 


Fig.  T,  Main  schematic  with  internal  coupler. 


connects  the  modem  and 
answers  the  call.  At  the 
same  time,  ICl,  pin  15  goes 
low;  this  places  RL2  in  the 
proper  position  to  select 
the  answer  mode  filter. 
When  fC1  detects  the  mark 
tone  from  the  other 
modem,  pin  23  goes  low; 
this  turns  on  the  clear-to- 
send(CTS)LED. 

The  originating  mode  is 
initiated  when  the  originat- 
ing switch  is  pushed,  caus- 
ing I  CI  I  pin  21  to  go  low. 
Next,  pin  4  goes  high,  clos- 
ing RLl,  connecting  the 
modem  to  the  phone  line. 
At  the  same  time,  pin  15 
goes  high,  operating  RL2 
and  selecting  the  orig- 
inating  filter.    When    IC1 


detects  the  mark  tone  from 
the  answering  modem,  it 
will  send  out  its  mark  tone 
from  pin  10  to  the  transmit 
buffer,  T1,  and  out  to  the 
Une,  Now  the  CTS  LED  will 
light  indicating  "ready  to 
exchange  data/' 

If  I  CI,  pin  16  Is  held  low, 
the  modem  is  placed  in  the 
self-test  mode.  The  demod- 
ulator is  changed  to  the 
modulator  frequency  and 
loops  back  to  the  terminal 
whatever  is  typed  in. 

When  a  break  (150  ms 
space)  is  received  by  the 
modem,  101,  pin  3  is 
clamped  high  and  stops 
data  exchange.  This  posi- 
tive-going level  triggers  a 
one-shot,  IC6,  which  sends 


Data 

Oflgfnafe 

Answer 

0     Space 

1070  H2 

2025  Hz 

1     Mark 

1270  Hz 

2225  Hz 

Table  1.  FSK  transmit  frequency. 


a  negative  pulse  to  ICI^  pin 
9,  automatically  releasing 
the  break  condition.  This 
negative  pulse  is  also  sent 
to  my  SWTP  6800  comput- 
er's MRST  line.  This  gives 
the  remote  terminal  the 
ability  to  operate  the  com- 
puter's hardware  reset  by 
sending  a  break. 

Construction  Tips 

I  built  the  modem  on 
four  printed  circuit  boards, 
consisting  of  the  following 
circuits:  the  internal 
coupler,  the  filter,  limiter, 
and  threshold  detector  the 
modem  !C  and  RS-232 
chips,  and  the  power  sup- 
ply. You  can  use  whatever 
construction  technique 
you  prefer.  1  always  socket 
all  integrated  circuits.  This 
time  I  had  to  replace  the 
24-pin  socket  with  one  of 
better  quality;  it  caused  all 
sorts  of  problems,  so  be- 


ware! I  guess  if  I  had 
socketed    the   sockets,    I 

might  not  have  had  that 
problem! 

I  made  the  ring  detector 
by  laying  an  NE-2  lamp  on 
top  of  a  flat  cadmium 
sulfide  cell  and  using  hot- 
melt  glue  at  each  end  of 
the  lamp  to  hold  them 
together.  Then  I  wrapped 
black  electrical  tape 
around  them  to  keep  out 
the  ambient  light  The  first 
one  I  made  didn't  work.  I 
found  that  some  NE-2 
lamps  require  about  100  V 
ac  before  they  light.  Next  I 
took  apart  a  neon  pilot 
lamp  assembly.  It  had  an 
internal  22k  resistor  in 
series  with  the  neon  lamp; 
this  combination  worked. 
The  series  resistor,  R3,  can 
be  from  22k  up  to  220k, 
depending  on  the  wattage 
rating  of  the  lamp.  Pretest 
your  neon-resistor  com- 
bination to  make  sure  it 
will  light  on  approximately 
70  V  ac.  I  bought  the  cad- 
mium cell  at  a  surplus 
store;  it's  about  y^-inch 
square  and  ^/i-inch  thick 
(any  similar  configuration 
you  can  come  up  with 
should  work  okay).  There 
are  also  commercial 
neon/CdS  modules  avail- 
able, such  as  the  Clairex 
DLM  3120A  Photomod. 

RL1  is  an  SPST  12  V  dc 
relay  with  a  Ik  Ohm  coil, 
mounted  in  a  14-pin  IC 
package.  A  suitable  5  V 
relay  could  be  used  if  con- 
nected to  the  5  V  supply. 

RL2  is  a  DPDT  5  V  relay 
with  a  100-Ohm  coil, 
mounted  in  a  TO- 5  paclt- 
age.  You  should  be  able  to 
use  any  similar  relays,  In 
my  second  modem,  I  left 
out  RL2  and  just  used  a 
DPDT  switch,  mounted 
between  the  originate  and 
answer  push-buttons.  This 
made  construction  a  lot 
easier,  without  losing  any 
real  features. 

IC5a  is  just  used  for  in- 
version to  save  a  transistor, 

I  used  a  500"  to  600-Ohm 
transformer  for  T1,  The 
ideal  value  for  the  side  that 
connects  to  the  phone  line 


0^ 


166 


is  900  Ohms.  The  side  of  Tl 
connected  to  terminals  A 
and  B  can  be  anything  be- 
tween 500  and  Ik  Ohms, 
but,  whatever  value  it  is, 
Rl  (connected  to  pin  1  of 
IC2a)  should  be  adjusted  to 
match  it. 

All  the  frequency-deter- 
mining resistors  in  the 
originating  and  answer 
filters  should  be  1%.  All 
the  01  uF  capacitors 
should  be  5%  or  better, 
mylar  or  pofystyrene. 

A  lot  of  phone  com* 
panies  require  you  to  rent 
(from  them)  a  coupling 
device  when  connecting 
external  equipment  to  their 
lines.  There  are  several 
types  of  coupling  devices 
that  will  give  the  same 
auto  answer  and  discon- 
nect features  as  the  inter- 
nal coupler  described  here. 
One  is  a  CBS  data  coupler 
which  has  RS-2 32-compati- 
ble signals.  If  you  use  one 
of  these,  the  optional  data 
coupler  interface  (see  Fig. 
3)  is  used  in  place  of  the  in- 
ternal coupler.  This  circuit 
will  provide  the  RS-232 
levels  needed  by  the  phone 
company's  CBS  data  cou- 
pler. Rl  should  be  changed 
to  a  600-Ohm  resistor, 
because  the  customer 
sides  of  their  couplers  are 
600  Ohms. 

Testing  and  Adjustment 

The  modem's  hand- 
shaking signals  should  be 
tested  first.  Connect  a 
small  high-impedance 
speaker  (100  Ohm)  or  fre- 
quency counter  to  the  line 
terminals  of  the  modem. 
Turn  on  the  power  and 
push  the  answer  push- 
button; you  should  hear  a 
2225  Hz  tone.  The  level 
can  be  adjusted  by  R2, 

Next,  connect  an  audio 
oscillator  across  the 
speaker  and  apply  a  2225 
Hz  signal,  push  the  origi- 
nate push-button  and,  if 
you  left  out  RL2,  change 
the  filter  switch  to  orig- 
inate You  should  hear  the 
modem  send  out  a  1 270  Hz 
tone,  and  the  clear-to-send 
(CTS)  LED  will  light  Next, 


Buff EH 


to  TTRMlhAL 


TO  IC1 

PIN  ID 


iC^fr 


85K 


WCDE 


'FREQUtllCr  DITfJl4fll*ll>ja  Rt&ISTQfli 


TO  ICl 


push  the  break  push- 
button; the  modem  should 
send  a  1 50  ms  1070  Hz  tone 
every  time  this  switch  is 
pushed.  Now  push  the 
disconnect  switch;  the 
modem  will  send  a  3-seC' 
ond  1070  Hz  tone,  the  CTS 
LED  will  go  off,  and  the 
modem  will  stop  sending. 

The  transmit  level  (R2) 
will  be  adjusted  next.  Dial 
up  a  friend  and  have  him 
leave  his  phone  off  the 
hook.  With  the  modem  line 
terminals  connected 
across  the  phone  line,  push 
the  answer  push-button 
and  hang  up  your  phone,  or 
operate  the  line  switch  to 
the  modem.  You  have  17 
seconds  to  measure  the 
signal  level  across  the 
phone  line  with  an  un- 
grounded meter.  Use  the 
output  jack  or  connect  a 


Fig.  2.  Filter  circuit, 

OA  uF  capacitor  in  series 
with  the  meter  and  adjust 
R2  for  a  level  of  -15  dBm, 
0.14  V  rms,  or  039  V  p-p. 

Next  have  your  friend 
call  you  back,  but,  before 
he  does,  the  modem  should 
be  on  and  connected  to  the 
phone  line,  and,  if  you  left 
out  RL2,  place  the  filter 
switch  in  the  answer  posi- 
tion. When  he  calls,  the 
phone  should  ring  once.  If 
it  does,  wait  a  few  seconds 
and  pick  up  your  phone. 
The  modem  should  be 
sending  out  a  2225  Hz 
tone.  If  the  phone  keeps 
ringing,  the  ring  detector  is 
not  working. 

To  test  the  data  section, 
connect  the  data  in  and  out 
to  something  that  speaks 
RS-232  at  300  baud  or  less. 
The  modem  does  not  care 
about  format;  it  converts 


to  tones  anything  that 
comes  into  it.  I  used  my 
SWTP  CT  1024  terminal. 
Turn  on  the  modem  and 
push  the  answer  switch. 
Turn  on  the  test  switch. 
NowtheCTS  LED  will  light, 
and  what  you  type  on  the 
keyboard  will  be  looped 
back  and  printed  on  the 
screen.  If  you  installed  the 
manual  filter  switch, 
change  it  to  the  originate 
position  (this  is  one  of  the 
things  that  RL2  does  auto- 
matically). This  is  about  all 
the  testing  you  can  do  until 
you  find  someone  else  with 
a  modem  or  build  two  tike  I 
didi 

Interface  and  Operation 

I  connected  the  modem 

to  my  system  by  parallel- 
ing it  across  the  CT  1024 
data  in  and  out  lines.  This 


167 


]^ 


^0  tUS 


!»i 


•*i 


p  ^-^ 


E  — 


4  fUjiF 


I 


sti.im 


f/g  3  Opvona^  CSS  dara 
coup/er  inteitace 

wa\  1 1  acts  like  anather 
teinMuai  that  r.an  access 
the  riMiiputer  over  the 
phone  line 

*  dse  the  rrK»dt?fTt  as  a 
teMantal  orrlv  like  f'alking 
tu  d  iinicihare  t.uriipuLer, 
just  tonnect  it  to  the  ter 
rniiial  and  disconcert  the 
rest  ut  the  system 

When  usiiig  rnodems  a 
poim  to  reiTieiTibei  is  that 
one  end  must  be  in  the 
ofigmate  and  fhe  other  in 
the  doswei  mude.  ii  doei 
not  really  matter  whit  h 

The  hand-shakrng  tones 
i-dfi  be  lost  to"  up  tLf  I? 
secundb  beior^.  the  con 
neLtion  will  be  lust  but 
d^ta  ieni  whei.  the  CTS 
LED  IS  off  will  be  lost 

During  at  li  ise^  tr  you 
are  the  originating  fnodem, 
dial  fhe  number  you  want, 
and  n  wU!  he  aoswered  by 
a  perbun  oi  d  modem  If 
you  heai  a  tone  vou  have 
17  ietonds  to  push  yuiir 


originate  svv'ttch  and  hang 
up  or  change  vour  line 
swUch  to  the  modem 
Vvheii  yuur  niodenr  detects 
the  tone,  it  will  send  out  its 
mark  tone:  then  the  CTS 
LED  will  light,  and  the  data 
can  now  be  exchanged 

It  you  are  calking  to  an 
bVvTP  computer  who>e 
MRS!  line  ts  connected  to 
the  reset  terminal,  sending 
a  break  will  reset  the  com- 
puter to  its  Mikbug^'^ 
operatuig  system  Oper 
dting  the  disconnect  push- 
button will  cause  the 
modem  at  the  othei  end  to 
hang  up. 

Also  remember  that  it 
the  muden^i  js  on  and  con- 
nected to  the  phone  line,  it 
Will  answer  all  calls  you 
get  It  could  be  someone 
not  expecting  to  get  a  2225 
Hz  tone  in  his  eai  and  they 
could  report  your  phone 
out  ot  order.  Ihebesithmg 
would  be  if  you  had  a 
separate  phone  line  just  tor 
the  modem. 

For  my  acid  test,  I  left 
line  mudem  at  home  and 
the  computer  loaded  with 
games:    the   other    I    took 


tlOV«C 


60C  r  a 


i.Mi4ClT-l? 


■<3]-ia 


Fig  4  Power  supp/y. 


with  my  terminal  over  to  a 
friend's  home  I  draled  up 
the  computer,  and  we 
jiayed  games  for  tour 
lours  il  worked  greati 
Imagine  what  I  could  do 
with  a  floppy  back  at  the 
computer!  I 


References 

1  Felsensiein,  Lee.  Build  Pen 
nywhislie  the  HobDyist's 
Modern  Popular  Electronics, 
March    19/6. 

2.  Laaaastar,  Dori.  TV  fypewrif 
er  Cookoook 


Z,  Motorola    MC6860L    data 

sheet. 

4  De  Lavne,  Jon,  ■*Lovv-speed 
MoQem  System  Design  Using 
the  IV*C68bO;  Motorola  Ap- 
pjication  Note  AN-747- 

5  Nash,  Garth.  Low-speed 
Modem  Fundameniafs/'  Motor- 
ola Application  Note  AN'731. 

6  Lange,  Ron.  *  Bui  Id  the  S35 
MoOem/  Ktiobiiud,  November, 
1977 

7  StarH.  PeieL  "Solid  biate 
Teltsphones  Ring  Relay/*  73 
Mdgaztne  Apiii,  1974. 

8  Whippife     Spenser       basrc 
Telepnone  Systems.    /3  Maga 
zirw.  Apr! I' June.  1975 


Chae-up  of  modem  numbet  two  tvery  thing  was  by/7f  on  one  lulu  it  boafd.  This,  does  not 
have  the  auto  answer  teaiure. 


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Modified  character  set 


Without  3  doubt,  the 
KIM-1  microcom- 
puter has  to  be  one  of  the 
slickest  little  rigs  on  the 
computer  market.  It  is  be- 
ing put  to  work  on  alt  types 
of  ham-oriented  applica- 
tions. It  is  decoding  Morse 
and  RTTY  and  transmitting 
Morse  and  RTTY,  and  all  of 
this  with  only  the  IK  of 
memory  that  comes  with 
the  unit.  (8080,  eat  your 
heart  out)  At  the  time  I 
was  first  seeing  all  of  these 
articles  (in  73  Magazine^  of 
course),  I  did  not  have  a 
computer  and  was  having  a 
terrible  time  deciding  on 
just  what  I  should  get. 
After  seeing  Wilfred 
Gregson's  article  (Sep- 
tember, 1977)  on  "Receiv- 
ing RTTY  with  the  KIM" 
and  several  others,  I  de- 
cided on  buying  my  name- 
sake. 

When  I  first  tried 
Wilfred's  program,  I  was 
amazed  at  what  I  was  see- 


la 


ing.  Even  with  the 
7-segment  display,  the 
words  were  very  easy  to 
distinguish.  I  was  quite 
heavily  involved  in  RTTY  at 
the  time,  so  I  had  a  ter- 
minal unit.  I  found  the 
KIM-1  much  more  tolerant 
of  the  various  things  that 
affect  RTTY.  Such  things  as 
distortion  of  the  character 
pulses  that  would  drive  the 
old  Model  19  crazy  did  not 
seem  to  bother  KIM  very 
much  I  was  also  using  a 
HAL  DS  3000  version  2  in 
my  RTTY  operations.  For 
anyone  familiar  with  this 
unit  they  will  know  that 
besides  featuring  the 
Baudot  code,  it  is  an  ideal 
computer  terminal  in  the 
ASCII  position  It  was  only 
logical  that  1  should  want 
the  KIM  to  deliver  the 
RTTY  to  the  HAL  terminal 
so  I  would  not  have  to 
struggle  with  the  7-seg' 
ment  display.  This  is  the 
basis  of  this  article.  It  may 


170 


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171 


M 


seem  rather  ironic  to 
receive  ASCII  on  a  video 
terminal  that  already  can 
receive  m  Baudot,  but  this 
is  aimed  at  the  computer 
hobbyist  who  would  like  to 
print  RTTY  on  his  Model  33 
or  on  his  ASCII  terminal 
and  does  not  have  normal 
Baudot  provisions. 

I  guess  you  could  call 
this  a  glorified  ASCIIto- 
Baudot  converter,   but  to 


say  that  would  be  an  in- 
justice. Not  only  will  you 
get  the  full  upper  and 
lower  case,  but  you  will 
also  get  something  called 
"unshift  on  space"  What 
this  means  is  that  if  you  are 
in  upper  case  Baudot  and 
you  receive  a  space  code, 
the  unit  will  automatically 
shift  back  to  tower  case 
This  might  not  seem  like 
much,  but  in  the  presence 


Program  listing. 


O^DG  A9  7F 

D202  60  A\       n 

0205  AO  Ofi 

0207  A2  09 

0209  A9  00 
03aB  fl^  E4 
0200  2C  00   17 

02 1 0  30  03 
0217  ac  00   02 
0215  A9  or 
0217  eo  07   17 
02  M  m  00 
one  S5  £7 


02)  E 

A9 

ID 

0220 

&^ 

E5 

0222 

2C 

07 

\1 

0225 

30 

03 

0227 

4C 

22 

02 

077A 

A  9 

14 

022C 

8D 

n7 

n 

072F 

2C 

ot 

17 

0232 

50 

D3 

02  M 

4C 

2f 

02 

0237 

20 

00 

17 

02  3  A 

ro 

06 

02 IC 

A5 

E7 

02  31 

09 

Ef 

0240 

e* 

e? 

0242 

46 

E5 

§24  4 

^^ 

E5 

0746 

C9 

00 

024i 

FO 

03 

024* 

4C 

2h 

02 

0240 

*5 

r? 

02«r 

nR 

ri 

0751 

AS 

0252 

8!5 

E3 

02S4 

B9 

QO 

03 

0257  fl9  £7 

0259  4C  4  0      03 
0?5t:  24  FT 
025£  Id  03 

0260  4C  6)       02 
0Z63  06  E7 

[^  172 


LDA    I  mm    7F 

STA    abs    174  1 

LDY    I  mm    Of 

LOX    fnm    09 

LDA    riiim   00        Put    I  trs    Trr    tfte    Vtrs/ffgs    b^ti 

5TA,2    00E4 

BIT    (700      look    for   g    start    bit 

BPL   briBch    »*    ^©tecf   start 

IMP  020t)         tot?li    afTBln. 

LOA    inm   OF      set  rn«    first   time    tfeloy 

5TA    B^s    I70T 

LDA    Imh   00      clf^ar   ciev   cli^ri,    register 

Slfstt   fr0£7 

LDA    Iwp    10      s«t    tilt    pdsTtTort    register 

STA.jT    OOE^ 

BIT    1707    Is    first    4>lay    tUTstvwd    7 

0Mt    branch    1*    vsi^ 

J**P    If    not    back    to   02Z2    and    waif 

LDA    fniffi    14      5«t    timer    ^or    second    delay 

.STA   nb%    1707 

Bit  1707  Ik  timer  f  [r^rshed? 

BMP   branch  If  yes 

JMP   It  not,  go  to  022F  arrd  wait 

B»T   *i?«(i  the  st«t©  of  rnput  i7O0 

BMI   tr  it  U  "  0  "  .do  not  toad 

LDAp?  load  th#  bU  6+  00E7 

0aA,2  00E5 

STA.z  OOEt 

LSR,z    00E5      snIH    b^t   position    reofster 

LDA«2   OOEI^   Ch«€li    fc^^   sH    5^   hauH^t    ^har, 

CMP     fRN    00 

BEO   ail  f (nlsned  7 

JMP  to  022A 

LDA^i    0017       Mtteri    /    figyres    prefix 

ncji  ^  -    rtr»E4 

TAf      indsK    for    1opkui> 

STA,z      0OE3 

LDA    ahsfijy 

STA>i    ODE? 

JrtP   to    output    to   tarmtnaf    routTne 

0IT,z   00E7      ch<5ck    for    a    comprspirid 

BPL   to  fitncttan 

JMP   t<>   tlnlsh 

kBL,g   00€T   Decod*    le^tte^rs    f unction 


of  severe  noise  and  fading, 
this  is  a  blessing  in 
disguise  Here  you  will 
have  the  RTTY  printer  that 
manv  dream  about.  If  you 
take  the  trouble  to  get  this 
going,  you  will  be  in  for 
some  very  artful  RTTY  pic* 
tures. 

After  studying  the  pro- 
gram, the  first  thing  that  ) 
had  to  do  was  to  get  the 
OUTCH    subroutine    in 


there  somewhere,  With  this 
come  the  necessary 
changes  to  the  lookup 
table  so  that  the  characters 
that  are  OUTCHed  will  be 
the  corresponding  ASCII 
characters  One  of  the  first 
problems  that  was  en- 
countered was  inter- 
ference with  the  command 
detection  For  example,  if  I 
put  the  ASCII  code  for 
space,    20h,    in    location 


026S  ItA  £7 

0267  10  ^7 

0269  A3  00 
026B  fl5  E4 

026 D  AC  ai   02 

0270  50  07 
0272  A9  20 
0274  i5  E4 
0276  4C  nt       02 
0279  A9  01 
027B  m  01   IT 
02 7 £  SO  00   17 
026 1  m  1  ? 
0263  BD  07   !7 
02B6  2t  QJ      17 
0299  30  03 
O?a0  4C  86   02 
028E  A9  00 
02^0  8D  OO   17 
OJiJ^  4C  OD   02 
0296  EA 

0340  85  EO 

034?  S6  Ef 

0B44  B5  €7 

054(1  eg  BO 

034$  FO  ta 

054*  C9  OQ 

034C  FO  \9 

0?4E  rts  20 

0350  FO  I C 

05^2  C9  40 

03^4  FO  lA 

0>^6  20  AB   IE 

0559  A5  EO 

&55B  A6  £1 

0550  A4  E2 

dl^F  4C  5C   03 

0362  A9  OD 

Q3^A  B5  E-* 

0566  A9  20 

05Sa  4C  56   03 

036fi  Ag  07 

D?6D  flC  56   03 

0570  A9  00 

0572  4C  56   05 


BIT./    0OE7 

BFL    branch    to    'flgur&s    ^ricodft 

LDA     Imm    00 

STy\,?    00E4      latter*   cammand 

JMP    to    f I n I sh 

BVC      tell 

LDA    litiBi    20 

STA*?    00E4 

JMP  to   the   tif^ish 

LDA    {rm    or         BELL 

STA   abs    »701 

STA   ttti&    1700 

LDA    IHK    15        I'lltlSH      set    for   the    third    €«lav 

St A    Inn    1707 

BIT    1707         look 

BMt    bach 

jMfi 

LOA    liftfn    00 

STA    I? 00 

iMP 

NOP 

<:T/v.r    OOEO         save    "    A    " 

STXpi    OOEI         sav^  «*   X    " 

STY^f   001?        savt   «   ¥   -^ 

CWP    Imnri    60       r*   this   a    5p.%r(>   cotJ#    ? 

BEO    It    so.    Then    go   to   0>62 

CWP    rin«   00      1^    thTs    a    beM    cod«    7 

BEO    If    se«    th^n   «d    ts   0  567 

CiiP    t«m    7^       1^    ^i^fi    ^    "    FIG1    "   cod* 

SEO    If    so,    thsfi    fo   to   036C 

CUP    liiiR   40      Is   Tlvis  a   '^    LTRS    "    io^e    7 

iEO    It    *Q»    theri    go    to    056C 

JSR   OUTCM    s*nd    cljaracter    T©    rprnJnal 

lOA.r    OOEO      Restore   ***** 

LOX,i   OOEI       Restore    "    X    ** 

inV^E    pOE2       Restore    "    V    »♦ 

JMP   back    to  malri    prograin 

LOA    I  mm    Do      unshtft   on    space    roi^tlnu 

5TA,z    QOF^ 

LDA  Imm  20   space  rou-tlno 

JMP  to  OUTCH  Ht  0355 

LOA  Tmut  07  t>el,(  routine 

JMP  to  OUTCH  *t  0365 

LDA  Iftw  00  HULL  routine 

JMP  to  OUTCW  Bt  0356 


031 B,  the  command  detec- 
trnn  p^rt  of  the  prngram 
would  sense  this  as  a  FIGS 
command  and  all  the 
characters  received  a^^ter 
that  would  be  upper  case. 
Therefore,  for  all  the 
commands,  spare,  and  hell 
codes  in  the  table,  there  is 
another  part  in  the  output 
routine  that  will  look  for 
these  and  insert  the  correct 
ASCII  corle^  for  the  func- 
tion. After  these  modified 
codes  are  s*»nt  to  the  ter- 
minal, they  are  changed 
back  to  their  original  value 
so  the  command  detprtjon 
will  function  prooerly  Spe 
locations  0340|^  through 
0374h  for  this  function. 
The  values  for  FIGS  and 
LTRS  that  are  oi  rtput  to  the 
terminal  are  simptv  nulls 
because  we  do  not  want 
the  terminal  to  print 
anything  on  the^f*  com- 
mands If  these  wf^.re  not 
changed  to  nulls  the  ter- 
minal would  space,  20h  on 
a  FIGS  command,  or  out- 
put the  character  @ .  which 


is   40h    on    a   LTRS   com 

mand. 

The  next  ?tep  in  the 
modification  was  the  dele- 
tion of  all  unnecessary 
steps  in  the  program,  such 
as  the  display  and  all  the 
software  that  <;upDorts  that 
funri-ion  This  also  includ- 
ed the  '^MOVF  '  and 
"SETX^  parts  in  the  original 
program.  Vou  will  see  that  I 
also  eliminated  the  tuning 
part  from  the  original 
because  !  have  a  terminal 
untt  with  complete  t'lning 
facilities  If  you  were  to 
use  the  PLL  on  the  KIM  for 
your  terminal  unit  vou 
would  have  to  add  this  on 
at  the  beginning  So  do  not 
forget  to  change  the 
neressarv  commands  for 
rnout  from  ^hp  PL  I  circuit 
and  pin  8  on  the  applica- 
tion* ^onnpf^for 

I  used  H  high-*ipeed  *^ot- 
ter  and  Brumfield  reed 
relay  to  control  data  nn  om 
8,  but  I  would  suggest  the 
photo-coupler  as  the  best 
method    If  you  are  not  a 


RTTY  advocate  and  do  not 
have  a  terminal  unit,  ^he^e 
are  several  units  on  the 
market  now  which,  for 
their  price,  cannot  be 
beaten.  Many  of  these  do 
not  come  with  the  high 
voltage  loop  supply  which 
the  mechanical  units  such 
as  the  Model  19  require 
but  this  is  |ust  fine.  We  do 
not  require  the  high  pull-up 
voltage  that  the^e  old 
beasts  required  Rf^ mem- 
ber we  are  modern!  All  you 
neerf  15  thp  current  to  Hght 
the  LED  on  the  coupler. 
Thi^  eliminate*;  one  major 
expense  of  a  tprmina!  unit 
If  you  are  serious  about 
this  at  all  you  really 
should  invest  in  one  of 
these  cheap  terminal  units 
You  will  receive  some  fan- 
tastic art  and  see  some  of 
the  mn*;t  «*niova*^le  QSOs 
that  you  could  ever  wan* 
to  see  You  can  then  really 
enjoy  the  mode  and  nnt  be 
plagued  with  the  errors 
cau«;f*d  by  QRM  and  QRN 
I   hope  that  this  article 


wjII  lust  be  the  start  of  a 
whole  RTTY  aoerating 
system  for  the  K  iM  1 
owner,  featuring  all  the  lux- 
uries of  ^his  "receive"  arti- 
cle and  also  iome  -.^ery 
desirable  transm'^"  ftinc-^ 
tions  tike  Urge  memory 
buffer  for  typmg  faster 
than  the  output  rate  cor- 
rection Bnd  editine  of 
transmitted  data  before  it 
is  actually  transmitted,  and 
more  important,  very  little 
extra  hardware. 

Also,  if  you  are  thinking 
of  a  computer,  I  hope  I 
have  added  lust  one  more 
plug  for  the  K  fM1  You  will 

be  able  to  copy  all  RTTY  at 
all  standard  speeds,  lust  by 
changing  the  bi^-  m  the 
timer  (  would  also  tike  to 
talk  to  people  ^^r  qre 
KIM  1  owners  I  ysuaily 
hang  out  ?Hnut  14  090  on 
Sunday  at '140(17  So  please 
give  me  a  holler  anri  n-paybe 
we  can  trade  information 
on  ^hl*;  and  other  prugrams. 
f^)h  ves,  anybody  have  a 
floppy  on  a  K1M?B 


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Ed  Mehnert  NJNN 

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UHAT  IS  THE  LQNeilUDE  OF  THIS  LOCATIONf 

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SELECT   THE  FUNCTION  TOU  If  ANT   AfID  ENTER   THE  NUHBER 


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EKTER  LATiTtJBE  OF  DISTANT  POINT. 
f   48,fe3 

LNTER  LONGITUDE  OF  DISTANT  POINT, 
?  2.33 

niSTANCE  FROH  HOHTGONERY,  AL  TO  PARIS,  FRANCE  IS  4522  MILES 
THAT  DISTANCE  IS  7277  KILONETERS* 
BEARING  TO  PARIS,  FRANCE  IS  4A  DEGREES. 

m   TOt!  LTANT  OTHER  POINTS  CALCULATEB^  YES  OR  NO 


V  NO 


Fig.  1  Sample  run  of  program  instructions. 


distance  and  bearing  to 
any  other  point  in  the 
world.  Using  the  data  com- 
piled and  supplied  here 
with  the  program  will  yteld 
distance  and  bearing 
tables  to  major  US  cities 
and  all  the  DX  countries  on 
the  American  Radio  Relay 
League  [ARRL)  countries 
list. 

Haw  It  Started  and  Credits 
Due 

When  I  started  selling 
selected  pieces  of  amateur 
radio  gear  to  pay  for  my 

growing  computer  system, 
my  ham  radio  colleagues 
always  came  up  with  the 
old  familiar  ''What  will  it 
do?"  or  "Td  build  one  of 
those  computers  if  I  could 
find  a  use  for  it/'  I  had  a 
canned  five-minute  disser- 
tation on  the  virtues  and 
potential  applications  for 
my  system  which  I  could 
immediately  recite,  This 
usually  quieted  them,  but  I 
wanted  a  good  amateur 
radio  application  to  prove 
that  my  computer  could 
"really  do  something/' 

I  got  the  idea  for  this 
program  from  Ed  Mehnert 
N3NN  while  he  was  giving 
a  talk  on  DXing  to  our  local 
Twin  Base  Amateur  Radio 
Club.  Ed  mentioned  that  he 
had  developed  a  computer 
program  written  in  BASIC 
on  a  time-sharing  system 
which  allowed  him  to 
calculate  the  distance  and 
bearing  to  the  DX  coun- 
tries  At  that  moment,  the 


light  bulb  in  my  head  came 
on,  "If  it  will  work  on  a 
time-sharing  BASIC  sys- 
tem, it  wilt  work  on  my 
IMSAir  I  said  to  myself. 
Then  I  knew  1  had  found  a 
good  ham  radio  program 
for  my  computer  With 
Ed's  blessing,  I  rewrote  his 
program  and  used  the  ex- 
tensive data  he  compiled 
on  the  DX  locations  to 
come  up  with  this  program. 

The  General  Theory  and 
Calculations 

Any  edition  of  The  ARRL 

Antenna  Book  features  a 
section  on  finding  direc- 
tions. This  includes  a 
description  of  the  calcula- 
tions for  Great  Circle 
distances  and  bearings  be- 
tween any  two  points  in  the 
world.  These  are  based  on 
two  formulas  using  trig- 
onometric functions. 

For  distance:  Cos  D  ~ 
sin  A  sin  B  +  cos  A  cos  B 
cos  L. 

For  bearing:  Sin  R  ~  cos 
B  CSC  D  sin  L > 

A  =  your  latitude  in 
degrees 

B  =  the  latitude  of  the 
distant  location  in  degrees 
(latitudes  in  the  Northern 
Hemisphere  are  positive 
and  those  in  the  Southern 
Hemisphere  are  negative), 

L  —  longitude  dif- 
ference  between  the  two 

•The  American  Radio  Relay 
League,  The  ARRL  Antenna 
Book,  Twelftti  Ed.,  Newlngton, 
Conr^ecticut.  1970,  p.  284. 


3    T74 


cniES  LISTING   CENTERED  QN  nPNTGOrtERY,    AL   FDR   J  Alt   HEISE    -   UA^UOn 
HCARIMOS  AHA  DISTAItCES  TO  ttAJOf^  US  CITIES 


HEARINGS  TO 
nlL    -   IIEAMS 


D%    LDCATIONS   ON   Afif^L   COUNTRIES   LIST 
A   CQUMTRy   DELETED  FROrt  ARRL  LIST 


m  LISTING  CElflEI^EB  FRDN  nCTNT&OflERTp   AL  FDR  JAH  HEIS£  -1144^00 


CITY 


HILES     K/N     BEARING 


ANCHORAGE 

3423 

5509 

325 

ATLANTA 

149 

240 

47 

KANeOR-ME 

t276 

2053 

42 

EIRNIHGNAH 

dt 

142 

341 

BDISE-ID 

17f3 

2885 

304 

BOSTON 

1009 

1753 

46 

rHAftLOTTE 

374 

602 

S6 

r:HEfENN£ 

1191 

1917 

306 

CfNClNNATI 

4fl1 

774 

12 

CLEVELAND 

d84 

HOI 

20 

rOLUhHA-SC 

328 

528 

60 

HALLAS 

6M 

985 

376 

DENVER 

1U0 

1867 

301 

[tES-HOINES 

750 

1220 

330 

DETROIT 

714 

1149 

14 

GREAT-FALLS 

1678 

2?00 

316 

HONOLULU 

4403 

7086 

200 

HOUSTON 

577 

9?9 

255 

INEIANAPOLIS 

510 

034 

1 

JACKSONVILLE 

310 

499 

115 

KANSAS-CITT 

661 

1064 

318 

trio  XVI LLE 

200 

463 

27 

I  AS -VC GAS 

1660 

2671 

207 

IITTIE-ROCK 

303 

6U 

297 

1  DS~ANGELES 

1042 

2964 

282 

lOUISVILLE 

409 

658 

5 

HEH^KIS 

288 

463 

313 

HiANf 

569 

916 

141 

niLllAUKEE 

74S 

1199 

353 

HiNN-ST.RAUt 

950 

1529 

339 

niNOT 

1348 

2169 

329 

NA5f<UILLF 

2*4 

425 

354 

HEyiN6?0N-ARRL 

990 

1593 

45 

NEU-ORLEANS 

370 

435 

233 

KEU'TORK 

895 

1440 

46 

NORFOLK 

654 

1052 

57 

lIlLAHONA-CITr 

479 

1093 

291 

DifANA 

820 

1320 

322 

F'ETFI*I0R0yGH-73 

1069 

1720 

43 

PHUAIELPHIA 

815 

1312 

46 

F-NOENIX 

T49t 

2399 

279 

flTTSBURIi 

6A0 

1062 

30 

rORTLANB 

21 3A 

3437 

306 

RAPID-CITV 

12(9 

1962 

316 

ST. LOUIS 

496 

790 

334 

!?ALT-LAKE-ClTy 

1535 

2470 

300 

SAN-FRANCISCO 

2D  64 

3322 

291 

SEATTLE 

3158 

3473 

310 

tan;>a 

374 

602 

142 

UASHINGTON-BC 

693 

1115 

46 

UICHITA 

7594 

12221 

357 

Fig.  2.  Sample  run  of  US  cities  list 


locations.  In  this  program, 
L  =  LI  -  L2,  where  LI  is 
your  longitude  and  L2  is 
the  distant  location- 
Longitudes  in  the  Eastern 
Hemisphere  are  positive 
and  those  in  the  Western 
Hemisphere  are  negative. 

D  =  distance  in  nautical 
miles  or  minutes  of  an  arc. 
One  Great  Circle  arc  is  60 
nautical  miles  and  1  min. 
=  1  nautical  mile  = 
1.15078  statute  miles.  In 
this  program,  the  output  is 
converted  to  both  statute 
miles  and  kilometers. 

R  =  the  direction  of  the 
distant  location  from  vou 
in  degrees  east  or  west  of 


north  or  south. 

What  this  means  is  that 
the  result  will  be  between 
-90  and  +90  degrees.  This 
must  then  be  converted  to 
0-359  degrees.  For  exam- 
ple, a  raw  bearing  of  17 
could  mean  0  +  17,  180  - 
17,  180  +  17  or  360  -  17. 
Thank  goodness  for  the 
computer  to  keep  track  of 
all  the  signs. 

Most  BASIC  interpreters 
do  not  have  arcsin  and  arc- 
cos  functions;  therefore, 
the  arctangent  function  is 
used  to  get  cos  C  and  sin  R 
in  the  formulas  back  into 
degrees  based  on  the  fol- 
lowing relationship: 


DX  PREFIX 

NILES 

K/M  IE 

ARtNG 

1 

A2C 

8338 

13418 

lOf 

7 

A  35 

6811 

10972 

252 

3 

A4X 

7727 

12435 

38 

4 

A6X 

8156 

13125 

37 

5 

A7X 

7580 

13198 

41 

4 

A9X 

7451 

11991 

40 

7 

AC  3 

8320 

13402 

S 

fl 

AC4 

8164 

13138 

2 

9 

AP 

7902 

12717 

24 

10 

lU 

8074 

12993 

332 

11 

81-N 

7241 

11653 

343 

12 

BT-CTR 

7671 

12345 

351 

13 

lY-S 

8430 

13566 

337 

14 

C21 

7151 

1 1  500 

278 

15 

C3I 

4691 

7549 

53 

16 

CSA 

4511 

7260 

90 

17 

C6A 

610 

995 

124 

10 

C9rt 

8743 

14070 

92 

19 

CE 

4620 

7448 

166 

20 

CE9-ANTR 

B45D 

13599 

100 

21 

CEOA 

4372 

7036 

203 

22 

CEOX 

4049 

6516 

173 

23 

CE07 

4599 

7401 

174 

24 

CH 

694 

1117 

!57 

25 

CH 

4430 

7142 

66 

26 

CP 

3539 

5695 

158 

27 

CR3 

5552 

0935 

111 

n 

CR4-IIOy-D4 

4064 

6540 

91 

29 

CR5 

5503 

8985 

96 

10 

CR6'N0U-D2 

7424 

11947 

95 

31 

Cft7/C9Pt 

8743 

14070 

92 

32 

CRS'DEL 

9869 

15882 

302 

33 

CR9 

8409 

13533 

337 

34 

CR10-DEL 

9869 

15882 

302 

35 

CI 

4231 

6809 

61 

36 

CT2 

3332 

5362 

i? 

37 

CT3 

3890 

6273 

69 

38 

CX 

5004 

0053 

155 

39 

D2ft 

7424 

1 1 947 

95 

40 

D4 

4064 

6540 

91 

41 

1^628 

0903 

14328 

77 

42 

OL-DEL 

4709 

7570 

43 

43 

DA-UE5T 

4709 

7570 

41 

44 

Bh-EAST 

4026 

7766 

39 

45 

HU 

0703 

14006 

327 

46 

£A 

4445 

7153 

57 

47 

EA6 

4012 

7744 

55 

40 

EAO 

4078 

6563 

74 

49 

EA9-CEUTA 

4410 

7097 

62 

50 

EA9/R-DEL 

4332 

6971 

76 

51 

Efl9/S-DEL 

4332 

6971 

76 

52 

EAO-&£t 

6549 

10S39 

86 

53 

EI 

4048 

65H 

44 

54 

IL 

5169 

8318 

92 

55 

EP 

6969 

11215 

34 

Fig.  J.  Sample  run  of  DX  countries  lisL 


3000 

OATA 

ANDH0RA6Ep61t- 

3005 

DATA 

BAHG0R-NEf44.0 

3010 

DATA 

80lSE-IDp43.6» 

3015 

DATA 

CHARLOTTE, 35. 2 

3020 

OAFA 

CINCINNATI, 39, 

3025 

DATA 

C0LUNBIA-SC,34 

3030 

DATA 

II£NVER,39.7,-r 

3035 

DATA 

DETROIT, 42.3,- 

3040 

DATA 

HONOLULII  *»•  ' 

3045 

IIAT4 

■r-1 

3050 

..**,K5p45,6U0 

DATA 

44.5,?0-S0CJ2 

4495 

DATA 

7X, 36, 3, 8^6, 12 

4500 

DATA 

BZ,29,47,9A1,4 

4505 

DATA 

9Kt29,40j9L1,B 

^510 

DATA 

9H"UEST,3J01p 

4515 

UATA 

9V1-S]N0Jt104 

4999 

DATA 

ENEAtA2,2,2 

9999 

END 

150t*TLANTA,33-75,-84,4 
p-60.8|FIRnrNGHAnp33.5,-06.0 
-II  6. 2,  IflSTQ**, 42 -4, -71 
,'80*a,CHEyE#IHE,4l.2,'10J   '^ 
I, -04. 5, CLEVELAND.*'   ' 
,-81, DALLAS, 37  .,fV,  T0,3,-67 

O^*'*^*  jp44,4X4,32,J5 

0^  .,,--f,39.5p5H3,-0,35 

rf,5T5J8p-16,5U7pl3,2 
3 p-1 7 T,5X5,, 5,32,514, -1,37 
,  1  5 ,  - 1  7  r  *^ 5  p  1  a ,  -77  p  70-AI)£N ,  1 2 , 5 
p 54 p?Pep -29, 5,28,707,-15,5, 36 
,5,-59,5|9Qp4,73,BRU7,-59 
4pl2p96p5.5,0p9Hp36p14,?J,-16p28 
p-13.5,9H-EflST,1.5pM0,5 
5,9Hp27,85,90p-5pl5,<3U,-3,29.5 
,9Xp-2.5,3O|9Y4-TR&T0B,lO.5p-6l 


Fig.  4.  Portion  of  data  statements  from  main  program. 

175  Jdl 


X  =  aictan 


aretan 


or  ar*^tar 


sir.  ^ 

::on  X 

V  1      os^X 

cos  X 

nmt 

\n 


sin 


?> 


PadiRn^  are  ns**H  in  per- 
forming the  rakulation*: 
rather  than  degrees.  The 
foMowmg  fcmiila'?  are 
used  to  convert  degrees  to 
radian';  ^nd  vke  ver^a: 


Opqre*?!?  x  r. 


Deqrf*es  t= 


180 


The  degree^  n^ii<f  be 
entered  in  decimal  form 
for  thi«;  oroer^m  and  not  in 
miniftes  and  -^e^^onds 


The  Program  De^rriphon 

"^he  program  was  built  in 
a  fiiodt  ;^r  mariner  with  a 
'^rrenu  type  selertron"  of 
che  funciiofi  desired  Each 
ftm<  tiop  y?*^<  this  fame 
calculation*;  which  are  all 
in  one  subroutine  This 
make?  the  program  easy  to 
modify  By  taking  out  the 
appropriate  block  of  call 
and  print  in^Jtrijrtioos  and 
data,  you  can  eliminate  un- 
wanted functions  I  used 
straiehtforward  BASIC 
commands  and  avoided 
any  known  unique  char- 
acte«^istics  of  my  system 
Numerous  remark  state- 
rneot^  were  L^sed  to  help 
clarify  the  program. 

The    instructions    from 
the   h'^ginning   up   to   400 


give  you  the  optton  to  get 
in^^^turtinn*;  th^p  mput  the 
datp»  for  youf  location,  ^ind 
finally  select  which  func 
tion  you  desire  As  you  can 
see  from  Fig  1  the  follow- 
ing  functions  are  available 
from  the  menu 

1,  This  option  prints  a 
global  grid  centered  on 
your  location.  This  allows 
you  to  make  your  own 
world  map  centered  on 
your  location.  These 
azimuthal  maps  can  be 
purchased  centered  on  a 
few  of  the  major  cities 
such  as  Chicago  or  New 
York,  but  this  function  pro- 
vides the  data  necessary  to 
make  one  for  any  central 
location 

2.  This  option  prints  the 


distances  and  bearings  to 
over  fifty  sele-^ted  US  cities 
using  the  data  provided  in 
the  program  You  can  add 
more  if  you  wish. 

3.  This  notion  prints  the 
distances  and  bearings  to 
all  the  DX  countries  on  the 

ARRL  countries  list  These 
are  listed  alphabetically  by 
radio  call  area  prefix 

4.  This  option  gives  the 
cities  list,  automatically 
followed  by  the  DX  list. 

5.  This  option  allows  you 
to  enter  any  distant  loca- 
tions at  the  terminal  and 
get  the  distance  and  bear- 
ing in  return, 

6.  This  option  restarts 
the  program  at  the  point 

where  you  input  the  cen- 


Main  program  listing. 


5? 


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MO  REN  -  dOO  NUMBERED  STATEMENTS  REA&  THE  StCONfi  SET  OF 
602  REN   lAT^  UNICH  IS  iHf  D)f  COUNTRIES  LIST  nAT4. 
6^1   REN   605  TO  410  FfN9  rHE  END  OF  TKF  FIRST  I^ATA. 
^95  READ  n4«ii^L2 
MR  IF  HI  -  'rNPAT#l"  THEN  614 

M*  msm  2000 

AI5  PRINT      UtARTHGS  TO  DX  LOCATIONS  Oi*  ARRL   COUNTRIES  LIST** 

if-^f*  PRllff      gFi     -    NFANE   A   COIINTRt    DElFTFD  FRON   ^RRL    LIST" 

625  PRTWT 

^30  PRINT  nx  ilSTiNG  CENTERED  FROrt  "jW*r  FOR  ";«• 

<^35  PRINT 

640   PPINTTAR5;'DX   Pf^EFlX     LAT/L0Nr>            NILES       K/H     BFAfitNG" 
645   PR1  NT '^ **•-*- — * — ■ -,-«,, ^-— -— ™. ' ^-^ 


M 


IB 


tral  location  data.  This  is 
useful  when  you  are  pre- 
paring several  lists  for  dif- 
ferent locations  — for  all 
your  ham  friends. 

7\  This  option  simply  ter- 
mi  nates  the  program. 

The  400-series  state- 
ments all  correspond  to  op- 
tion one,  which  is  to  print 
the  global  grid  Nested 
loops  are  used  to  perform 
the  calculations  with  the 
latitude  incremented  by  1 5 
degrees  at  a  time  from  -90 
to  +90,  while  the 
longitude  is  varied  from 
-180  to  +180  in  in- 
crements of  30  degrees. 

The  ^OO-series  state- 
ments are  used  to  perform 
option  two,  which  is  to 
print  the  US  cities  list  (see 


Fig.  2)  A  flag  (F)  is  used  to 
determine  if  lists  of  both 
cities  and  countries  are 
desired.  The  3000-series 
data  statements  contain 
the  cities  data  used  with 
this  option.  The  program 
looks  for  ''ENDATA1"  in 
the  city  field  to  tell  it  there 
are  no  more  cities.  The 
data  is  then  restored  for 
use  again,  and  the  program 
either  goes  back  to  the 
menu  or  on  to  prepare  a  DX 
country  list. 

The  600-series  state* 
ments  correspond  to  op- 
tion three,  which  is  to 
prepare  the  DX  countries 
list  (see  Fig.  3),  If  the  entry 
here  is  from  the  menu,  the 
program  first  reads  the 
data    and    looks    for   "EN- 


DAT  A1"  in  the  country 
field.  This  means  it  must 
read  through  all  the  cities 
data,  but  since  no  calcula- 
tions  are  performed,  vir- 
tually no  time  is  lost.  The 
data  for  the  DX  countries 
list  is  contained  in  the 
4000-5eries  data  statements 
(see  Fig.  4).  When  this  data  is 
reached,  the  program  oper* 
ates  just  as  it  did  for  the 
cities.  It  looks  for  an  "EN- 
DATA2"  in  the  country 
field  to  indicate  it  has 
reached  the  end  of  the 
countries  data.  The  pro- 
gram then  returns  to  the 
menu. 

The  700-series  state* 
ments  compose  the  routine 
used  to  calculate  indi- 
vidually-entered   distant 


points.  This  routine  is  set 
up  in  a  loop,  which  allows 
you  to  continue  to  cal- 
culate individual  points  un- 
til you  desire  to  return  to 
the  menu. 

The  1000-series  subrou- 
tine performs  all  the 
calculations.  The  subrou- 
tine can  be  used  as  a  stand- 
atone  program  if  desired.  It 
requires  that  A,  B,  LI,  and 
L2,  which  I  have  previously 
discussed,  be  provided  It 
returns  the  following 
results:  D1  =  the  distance 
in  miles;  D2  =  the  distance 
in  kilometers;  R2  —  the 
bearing  in  degrees.  All  of 
these  are  rounded  to  the 
nearest  integer. 

In  the  routine,  L  is 
calculated     and     then 


hi^  READ   HI,I,L2 

^iS   IF   ilf="FN»i^Tfl2-    THEH  696 

^.70  m%m    tODO 

^.eO    IF    K-^^   THEN   kn 

a^  soro  650 

4^fO  liOSUK   2090 
ff5  £DtO  640 
^f6  RESTOI^E 

7«0  fiErt   -  THE    ?00  l*U«6£REi^   Sl^^lErtlMfS   rlAKE   IIP    THE  RQUTIWE    TO 

/01    REM    -  CALCULATE    USER   EMTEftED   CDOrilMArtS  OWE    AT   A    TIrtE, 

:^05  f^ftlNT  "ErtTER   J^ISTANT   LOCATION   DISI&I^A  I  lOff" 

/1 5   INPUT  LI  HE   flit 

720   PRIWT 

725  PftlWT  "ENTER  LATITUDE  OF  OlSTANT  POmT." 

/3S  INPUT  B 

/to  PRINT 

^45   PfilWT  '^ENTER   LONGITUDE   OF   IrlSTiINT   POIrtT/' 

755   INPUT  L2 

7^0  GOSUS  lOOO 

745   PRINT 

770  PRINT  ■'DISTArtCE  FRDH   ";y*;"    ro   ";ini;"   IS   ";Oir  rtlLES*" 
7?l    PRIWTMHAT    DISTANCE    IS    "jD?;*   KlLOHHeRS," 

771  PftldT  "lEAftlNS   TO   ";«!*;"   !S   ";R3;   "   OEQftEES," 
775  PftJlIT 

7B0  PRlHTmO   %m  UANT   OTHER  P0II4TS  CALCULATED?    YES  OR  HO" 

715  P«INT 

790   tMPUT    It 

?f5   IF   Tl   ^  -ITES-    THEN  705 

7f?  60 TO  250 

IfiOO  REH   -    1000  SERIES  SUBROUTINE  PERFORfiS   ALL   CALCULATIONS. 

100T  LET  LSL2-LI 

ie02  REfl  -  X  15  A  Ft  AC  FOR  TESTliS  L 

1003  LEI  X=0 

1005  RFI4  -  BRING  L  UtTKiN  RANGE  -180  TO 

1010  IF  L<-ieO  &0  10  1025 

10IS  IF  L>180  GO  TO  1035 

1020  GOTO  1040 

m%   LET  l  =  L  +  J*0 

103D  GOTO  MOO 

LET  L=L-3A0 

IF  L<0  THEN  I !0u 

LET  t^\ 


IdO 


1935 
1040 
(045 
tlOO 

mo 

1115 
1119 
1120 


REN 

LET 

LET 
REN 
LIT 


H25  LET 
1130  LET 
1134  REN 


CONCERT   L   km   B   TO  RADIANS 
B1    =    6*3.14159/180 
I    =  t*3J4t59/190 

-  COMPUTE   THE   DISTANCE   ANGLE 
P>tCIS<LHCOS(An*CGS!Bi  I  *SIN(  AM  »5TN(Bn 
PUATN(SOR(  l-P*P>/P) 
P2=P1*l80/3-t4f59 

-  OiSTANCE   A*»6LE  ffOST   BE   POSITIUE    IF   HOT  ADD   \m 


1135  IF  P2<0  GOTO  1145 


1140 

1145 
1149 
1150 
1151 

1154 

irss 

1160 
1164 
IU5 

TUB 
1169 
1 1  70 
1175 
TI30 
nS5 
IffO 
1200 
1305 
1210 
1215 
1220 

\m 

1235 

1240 

1245 

1250 

1255 

1260 

1500 

1510 

1520 

1530 

1540 

1400 

1605 

1610 

1 620 

1630 

1635 

t640 

1645 

1700 

7000 

7001 

7005 

7006 

70O7 

7005 

2009 

?010 

?01T 

:*012 

7020 

7030 


GOTO  fl50 

LET  F2=P2+180 

REfl  -  COWPUTE  DISTANCE 

LET  01  ^  INT(P2*oO*1 -15152*. 5> 

LET  li2^HiTfDl*t,6a91+,5» 

RErt   -   COMPUTE   THE    BEARIitG  ANGLE- 

LET   R=CDStin«5IN{Ll/SlN(PtJ 

LET   Rt=ATN4R/S0R(1-R*Ri) 

REM   -    CONVERT   BEARINGS   TO   DEGREES   RQUHSEO  TO  flEAREST   INT 

LET    R2  =  jHT(CR1*tB0/3.l4159M.S) 

RE«   -    DETERNINE   WHAT   OUAflRANl    THE   BEARING   ANGLE    IS    li*  AND 

RErt   -   ADJUST    THE    DEGREES* 

IF    ABS<R}>.9?V998    THEN    1500 

IF   ABStf?)-:, 00174    THEN   f600 

LET   B2=(B+.n    i   3  J4I59/1B0 

LET   R3=C0S(L>»CCSiAnfC0Sie2^+SIN(F2J*SIN(A]  ) 

LET   R4=ATpf(SQRU-R3*R3y/R3J 

LET   FfA  =  C0StIi2)*SlNa^/SIWfR^i 

IF  X^l  THEN  1240 

IF  flBS(ft6)  V  AP5(RJ  THEN  ?:30 

LET  R2=360-ABS(R2) 

GOTO  1700 

L£T   R2  =    iai}+ABS?R2) 

GOTO   1700 

IF  AB5(R6I   ABStRlIHElt  1255 

LET  R2=  tB0-ABS(R2) 

60T0  1700 

LET  R2  =  A»Si«2* 

GOTO  1700 

If  X=1  THEN  fSiO 

LET  «2  =  270 

GOTO  1700 

LET  R2=90 

eOTO  1700 

IF  ABS(L)  >  178  THEN  U40 

IF  BsA  THEN  1630 

LET  R2-0 

GOTO  1700 

LET  ft2-1flO 

GOTO  1700 

IF  8>A  THEN  t630 

GOTO  1610 

RETURN 

REN  -  THIS 


REn  ' 

PRINT 

PRINT 

PRINT 

PRINT 

PRINT 

PRINT 

PRINT 

PR  IN  I 

*£'0 

RETURN 


ROUTINE  PRINTS  BLANK  LTNES  AFTER  EVERt  55 
LINES  OF  DATA  SO  PAPER  CAN  BE  CUT  STANDARD  SUEH. 


177 


:2 


brought  into  the  range  of 
-180  to  +180  degrees.  All 
angles  are  then  converted 
into  radians  and  plugged 
into  the  formula  to  com- 
pute  the  distance  angle. 
The  bearing  angle  is  then 
computed. 

The  rest  of  the  calcula- 
tions ensure  that  the  bear- 
ing angle  is  placed  in  the 
correct  quadrant.  For  most 
angles,  the  procedure  is  to 
take  a  slightly  incremented 
point  (0.1  degree)  from  the 
original  angle  and  com- 
pare the  sines  of  the 
original  and  incremented 
angles.  The  original  angle 
is  placed  in  the  correct 
quadrant  depending  on 
whether  the  sine  increased 
or  decreased  For  any  L 
that  is  positive,  the  bearing 
angle  will  be  in  quadrant  I 
or  li,  and  for  any  negative 
L,  it  will  be  in  quadrant  III 
or  tV  Keeping  this  in  mind, 
you  can  see  that  the  in* 
cremental  test  will  tell  you 
whether  to  add  or  subtract 


the  bearing  angle  from  0  or 
180  degrees  to  give  you  the 
final  bearing  angle. 

Before  the  incremental 
test  is  performed,  angles 
which  are  so  small  that  the 
test  could  put  them  into 
the  next  quadrant  are 
sorted  out  and  simply 
rounded  off.  Since  sin[0}  = 
0  and  sin(90)  =  1,  the 
folfowing  procedure  Is 
used: 

If  the  sine  is  positive  and 
very  close  to  1,  then  angle 
=  90  degrees;  if  the  sine  is 
negative  and  very  close 
to  1,  then  angle  ~  270 
degrees;  if  the  sine  is 
positive  and  very  close  to 
0,  then  angle  =  0  degrees; 
if  the  sine  is  negative  and 
very  close  to  0,  then  angle 
—  180  degrees. 

Once  the  distances  and 
the  bearing  angle  have 
been  calculated,  the  rou- 
tine returns  to  the  calling 
segment  where  the  results 
are  printed. 

The  2000-serie5  subrou- 


tine merely  prints  blank 
lines  and  new  page  headers 
to  keep  the  output  in  a 
page  size  format  A 
counter  (K)  is  used  in  each 
option,  tt  calls  the  new 
page  routine  after  every  55 
lines  of  data  are  printed. 

Sidelines  and  Miscel- 
laneous Information 

The   complete   program 

with  all  the  cities  and  DX 
countries  data  requires 
about  1 4K  of  user  memory. 
By  omitting  remark  state- 
ments and  some  of  the 
''frills/'  you  can  cut  the 
size  down  considerably.  By 
using  DATA  statements 
such  as  1  did  in  this  pro- 
gram, you  can  easily  add 
new  cities  or  make  changes 
to  the  countries  list. 

The  version  listed  here 
prints  out  the  latitude  and 
longitude  of  the  cities  and 
DX  countries.  After  a  few 
initial  runs  to  verify  the 
data,  I  went  to  a  new  ver- 
sion   in   which    1    stopped 


printing  the  latitude  and 
longitude  for  each  loca- 
tion. 

Entering  the  data  may 
look  like  an  enormous  task, 
but  to  me  it  was  well  worth 
it.  Hams  can  buy  listings 
similar  to  these  from  com- 
mercial sources,  but  they 
usually  cost  about  SIO.OO. 
Your  local  amateur  radio 
club  members  may  be 
more  than  willing  to  com- 
pensate you  for  your  ef- 
forts. 

A  feature  which  I  plan  to 
add  to  my  program  is  an 
alphabetical  listing  of  ma- 
jor cities  around  the  world. 
The  World  Almanac  gives 
the  latitude  and  longitude 
for  a  long  list  of  North 
American  cities  as  well  as 
several  world  cities.  I  use 
maps  in  the  Rand  McNalty 
World  Atlas  for  obtaining 
the  latitude  and  longitude 
for  other  locations. 

I  hope  that  this  program 
will  be  as  useful  to  others 
as  it  has  been  to  me.B 


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178 


t^  Reader  Senftce — soe  page  33i 


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Communications  Corp, 
191 1  Old  Homestead  Lane 
Greenfield  Industrfal  Park  East 
Lancaster,  RM  7601 

179 


^1  k  A 


TM 


Big  Max  Attacks 


it's  W2DU  vs.  K4KI 

in  the  battle  of  the  bazooka 


M,  Waher  Maxwell  W2DU 
PO  Box  lis 
Oaymn  NJ  088W 

Several  years  ago  I  was 
faced  with  a  perplexing 
question:  Why  the  popu- 
larity of  the  so-called  dou* 
ble  bazooka,  while  my 
bazooka  showed  no  vital 
signs  other  than  those  ex- 
pected of  a  simple  half- 
wave  dipole?  So,  I  per- 
formed an  autopsy. 

The  startling  results  of 
the  postnnortem  examina- 
tion were  published  in  Ham 
Radio, ^  and  the  graveside 
rites  were  reported  in 
QSTJ    Since   then,    it   has 


eluded  incofrectly  that  it 
still  lives.  1  will  uncover 
these  errors  so  that  it  can 
be  quickly  reburied. 

The  73  Magazine  article^ 
reporting  his  reexamina- 
tion of  the  double  bazooka 
(a  misnomer  for  the  coaxial 
dipole)  discloses  some  in- 
teresting and  valuable  in- 
formation. But  it's  unfor- 
tunate that  some  portions 
of  the  article  are 
misleading,  and  others  are 
totally  incorrect  (par- 
ticularly the  major  conclu- 
sionl  making  it  impossible 
for  the  uninitiated  to 
separate  fact  from  distor- 
tion. 


k  J. 


cannot  provide  a  worth- 
while  or  significant  im- 
provement in  bandwidth 
for  the  effort  expended 
(even  with  stubs  of  oj!>- 
timum  impedance),  unless 
the  feedline  impedance  is 
considerably  higher  than 
the  usual  50  Ohms. 

[rrors  in  the  Reexamina- 
tion Technique 

Mr.  Vissers  agrees  that 
my  conclusion  is  valid  for  a 
free-space  environment. 
Nevertheless,  because  he 
miscalculated  the  effect  of 
the  ''big  difference"  be- 
tween free-space  and  near- 
earth  antennas,  his  conten- 


can't  provide  in  free  space, 
by  simply  operating  the 
coaxial  dipole  near  earth. 

On  the  contrary,  fustthe 
opposite  is  true;  the  broad- 
banding  effect  of  the  stubs 
is  less  when  the  antenna  is 
near  earth  than  when  it  is  in 
free  space,  not  greater.  In 
view  of  Mr.  Vissers'  seem- 
ingly plausible  presenta- 
tion, how  can  this  be? 
Don't  his  graphs  showing 
swr  prove  that  the  stubs  are 
working?  Indeed  they 
don't.  With  all  due  respect 
to  Mr.  Vissers,  I  regret  hav- 
ing to  point  out  errors  in  his 
treatment  of  antenna  fun- 


In  examining  the  reasons 
why  he  arrived  at  conclu- 
sions that  are  directly  op- 
posite to  the  facts,  we  will 
discover  why  the  free- 
space,  thin-u^ire  antenna 
data  used  in  my  analysis  is 
relevant  to  antennas  near 
earth  Furthermore,  since 
mistreatment  of  the  fun- 
damental concepts  has 
generated  confusion  far 
beyond  the  realm  of  the 
coaxial-dipofe  antenna,  I 
feel  compelled  to  discuss 
the  mistreated  concepts  in 
sufficient  depth  to  clarify 
the  confusion. 

Validity  of  the  Thin-Wire^ 
Free-Space  Dipole 

To  begin,  let's  consider 
the  criticism  concerning 
thin  wire  for  the  dipolei 
radiating  elements.  The 
statement  that  there  is  no 
such  thing  as  ''thin-wire" 
coaxial  cable  has  no  mean- 
ing, because  there  is  no 
reference  defining  what 
"thin"  is.  He  has  simply 
misinterpreted  "thin"  to 
mean  vanishingly  thin,  in- 
stead of  following  the  stan- 
dard practice  of  specifying 
finite  thickness  of  radiators 
in  terms  of  wavelength  A. 
On  the  contrary,  the  anten- 
na terminal  impedances 
used  throughout  my 
analysis  are  based 
specifically  on  diameter  D 
of  the  outer  conductor  of 
RG-58/U  coax,  where  D  = 
0.140  inches  =  0.0000445A 
at  3J5  MHz,  which  is  in- 
deed a  ''thin  wire'^  at  ttiis 
frequency  (see  page  50^). 
And  in  asserting  that  there 
is  a  "big  difference"  in  the 
effect  on  bandwidth  be- 
tween free-space  and  near- 
earth  conditions,  Mr. 
Vissers  must  have 
overlooked  my  measured, 
near-earth  data  appearing 
on  page  48  in  the  Ham 
Radio  analysis/  and  in 
QST.^  The  difference  in  the 
effect  between  these  two 
conditions  will  be  explored 
in  detail  later  on. 

Improper   Selection   of   Q 
Spells  Trouble  in  Fig«  8 

Next,   let's  examine  the 


three  swr  curves  appearing 
in  his  Fig.  8.  He  used  these 
curves  as  the  "theoretical" 
basis  for  his  conclusion 
that  the  coaxial  stubs  in  the 
dipole  are  contributing 
significantly  to  bandwidth. 
However,  because  of  an 
improper  selection  of  Q  for 
antennas  near  earth,  these 
swr  curves  are  incorrect— 
the  true  values  are  more 
than  double  those  shown. 
Thus,  the  basis  for  his  con- 
clusion falls  apart.  AM  of 
the  swr  values  in  Fig.  8 
were  calculated  based  on 
resonant  antenna  reac- 
tances XLa  ^^^  ^Ca  (which 
were  unwisely  obtained 
from  Q)  in  his  Fig.  2.  By  in- 
correctly assuming  a  Q  of 
10,  the  resulting  400  Ohms 
obtained  for  reactances 
Xl^  and  X^a  's  less  than 
half  the  true  value  of  the 
resonant  reactances  found 
in  antennas  having  the 
dimensions  of  a  typical 
coaxial  dipole  resonant  at 
3.75  MHz  (length  L  =  125 
feet,  and  diameter  D  = 
0.140  inches).  Using  the  in- 
correct 400  Ohms  as  the 
basis  for  the  swr  calcula- 
tions resulted  in  the  op- 
timistic, but  impossibly- 
low  swr  values  in  Fig.  8. 
Ironically,  when  this  error 
in  reactance  is  corrected, 
and  the  affected  arithme- 
tic recalculated,  the 
resulting  swr  values  are 
nearly  the  same  as  those 
obtained  in  my  analysis. 
Thus  a  conclusion  similar 
to  mine  must  also  follow. 
Directly  related  to  the  im- 
proper choice  of  Q  in 
determining  the  value  of 
XLa  *^  the  contention  that 
Q  is  lower  when  an  anten- 
na is  near  earth  than  when 
it  is  in  free  space.  The  op- 
posite is  actually  true.  I 
will  show  later  how  Q  was 
used  improperly,  why  it  is 
unwise  to  obtain  Xl^  from 
Q,  and  why  Q  is  higher 
when  an  antenna  is  near 
earth  than  when  it  is  in  free 
space.  I  will  also  outline  a 
procedure  for  calculating 

the  value  of  XLa  ^f'*^^^  the 
L/D  ratio,  which  entails  less 
chance  for  error  than  when 


e.D 


iJ  5  8 

FREQUENCY  IMMiJ 


Fig.  1 


using  Q, 


Obtaining  Corrected  Value 
of  Xc  for  Swr  Calculations 

So  let's  ignore  Q 
momentarily,  and  start 
with  the  basic  length-to- 
diameter  ratio  L/D  = 
12570.140"  =  10,714.  From 
this  ratio,  which  deter- 
mines antenna  inductance 
La  and  capacitance  Ca  in 
his  Fig.  2  (detailed  pro- 
cedure comes  later),  we  ob- 
tain the  correct  value  of 
846  Ohms  for  reactances 

XLa  ^^^  ^Ca  ^^  the 
3. 75-MHz  resonant  fre- 
quency, instead  of  the  in- 
correct 400  Ohms  shown  in 
Fig.  2.  Using  XLa  =  846 
Ohms  in  calculating  the 
off-resonance  antenna 
reactance  X^  at  3,5  IsAHz 
yields  117  Ohms,  in  con- 
trast to  the  55.24  Ohms  in 
Fig.  3.  it's  too  bad  this  error 
wasn't  detected  early  on 
by  simply  checking  the 
55.24  Ohms  in  a  universal 
graph  of  antenna  resis- 
tance and  reactance  versus 
radiator  length  [or  frequen- 
cy), with  L/D  ratio  as  a 
parameter.  Such  a  graph 
appears  in  the  ARRL  Anten- 
na Book,  and  in  many  text- 
books on  antennas,  such  as 
Jordan  and  Balmain/ 
Schelkunoff/  or  King^  (and 
in  Figs.  2  and  4  of  my 
analysis-).  Another  way  of 
confirming  the  error  will  be 
disclosed  later. 

Because    of   the   simpli- 
fied procedure  used  to  ob- 


tain it,  this  corrected  off- 
resonance  reactance  of 
117  Ohms  is  still  only  an 
approximate  value.  To 
calculate  antenna-terminal 
impedances  that  agree 
niore  closely  with  the 
measured  data  requires 
more  complex  mathemat- 
ical procedures,  such  as 
those  of  Schelkunoff^  or 
King/  from  which  univer- 
sal impedance  graphs  are 
generated.  Thus  from  King 
we  obtain  a  more  accurate 
and  realistic  off-resonance 
antenna  reactance:  Xc  = 
108  Ohms  at  3.5  MHz  for 
our  L/D  ratio  {see  Table  2). 

Impact  of  Wrong  Xta  *rom 
Improper  Selection  of  Q 

To  confirm  the  cata- 
strophic impact  on  the  con- 
clusion, let's  now  compare 
the  results  using  the  cor- 
rect reactance  with  those 
using  the  incorrect  reac- 
tance. First,  using  the  cor- 
rected value  of  reactance, 
Xc  =  108  Ohms  with 
resistance  Ra  of  40  Ohms, 
we  get  a  realistic  swr  of 
7.75:1  at  the  antenna  ter- 
minals at  3.5  MHz  instead 
of  the  impossibly-low 
3.27:1  shown  in  his  Figs,  3 
and  8.  Why  is  the  3.27  im- 
possibly low?  Because  to 
obtain  a  raw,  uncompen- 
sated swr  of  only  3.27:1  at 
3.5  MHz  with  Ra  =  40 
Ohms,  it  would  require  a 
dipole  diameter  of  3.1  inch- 
es—22  times  larger  than 
the  0,14''  diameter  of  RC- 


183 


58/U  coax.  Remember,  RG- 
58/U  is  a  thin  radiator  at  3,5 
MHz] 

Second,  a  7.75;1  swr 
agrees  closely  with  data 
obtained  during  hundreds 
of  my  measurements  of 
similar  conditions  using  a 
General  Radio  rf  im- 
pedance bridge,  Model 
GR-1606A  (also  see  Bor- 
ton,^  Fig.  2).  In  contrast  to 
the  ±10%  accuracy 
specified  for  the  swr  in- 
dicator mentioned  in  the 
73  Magazine  article  (which 
cannot  indicate  reactance), 
the  General  Radio  bridge 
has  an  accuracy  capability 
of  measuring  resistance  to 
within  ±1%,  and  reactance 
to  within  ±2%. 

Third,  re-solving  the 
parallel  circuit  problem  of 
his  Fig.  5  using  the  cor- 
rected reactance,  Xc  = 
108  Ohms,  instead  of  55.24 
Ohms,  confirms  the  ca- 
tastrophe, because  the 
original  compensated  re- 
sistance of  116  Ohms 
(which  yielded  the  2.33:1 
swr)  now  becomes  331,6 
Ohms  when  the  parallel- 
circuit  reactance  is  can- 
celed (using  a  shunt  reac- 
tance Xl  of  122.8  Q,  instead 
of  853  Q).  With  a  331 .6-Q 
resistance  terminating  a 
50-Q  line,  the  uncompen- 
sated 7.75:1  swr  is  reduced 
only  to  6.63:1  (vs.  2.33:1  !)= 

In  proportion  to  the  fre- 
quency difference,  the  cor- 
rected impedance,  Z^  = 
40  -  j108  Ohms  (7.75  swr), 
agrees  closely  with  my 
measured  data  appearing 
in  the  80  meter  example  on 
page  48  in  my  Ham  Radio 
analysis,'  and  in  QSP:  At 
3.55  MHz  (50  kHz  closer  to 
resonance),  I  measured  Za 
=  50  -  j90  Ohms  (5.04 
swr).  With  perfect  compen- 
sation the  parallel-circuit 
resistance  is  212  Ohms, 
reducing  the  5.04  swr  to 
4.24.  Thus  the  amount  of 
mismatch  reduction  is  also 
proportional.  In  addition, 
at  3.5  MHz  I  measured  Za 
=  48  -  jllO  Ohms  (6.90 
swr).  Note  the  close  agree- 
ment with  the  corrected 
impedance,   Za    =    40    — 


j108  Ohms,  especially  the 
110-Ohm  reactance  com- 
ponent. Bear  in  mind  that 
both  my  data  were  mea- 
sured with  the  CR-1606A  rf 
bridge,  and  the  corrected 
data  represent  near-earth 
conditions.  Thus  the  errors 
in  the  Vissers  data  are  con- 
firmed. And  in  view  of  the 
close  agreement  between 
the  data  of  these  near- 
earth  antennas  and  the 
free-space  data  appearing 
in  Figs,  2  and  9b  of  my 
analysis,^  the  criticism  of 
using  free-space  data  in  my 
analysis  is  clearly  unjusti- 
fied. More  on  this  later. 

Procedure  for  Obtaining 
Xu  (^nd  Q)  from  the  L/D 
Ratio 

Let's  now  see  how  the 
resonant  antenna  reac- 
tance, XLai  15  calculated 
from  the  L/D  ratio,  from 
which  well  see  the  dif- 
ficulties both  in  obtaining 
XLa  from  Q  and  in  making 
an  accurate  assumption  of 
Q  unless  XLa  *^  already 
known.  The  basic  antenna 
characteristic  from  which 
values  of  antenna  induc- 
tance La  and  capacitance 
Ca  may  be  obtained  for  use 
in  the  equivalent-series 
RLC  circuit  of  Mr.  Vissers' 
Fig.  2  is  the  average  char- 
acteristic impedance,  Zq. 
Antenna  Zq  is  determined 
uniquely  by  the  physical 
dimensions  of  the  radiator. 
The  value  of  Zq  may  be  ob- 
tained from  the  length-to- 
diameter  ratio,  L/D,  using 
the  expression  Zq  =  120 
(loge2L/D-  1)  =  120(loge 
3000/0,140  -  1)  =  1076.7 
Ohms  (equation  1).  Anten- 
na inductance  La  and 
capacitance  Ca  nnay  now 
be  obtained  from  the  ex- 
pressions^ La  =  Zo/8fr 
(equation  2)  and  Ca  — 
2/Ti^f,'Zo  [equation  3), 
where  fp  =  resonant  fre- 
quency. Since  Lg  and  Ca 
are  both  dependent  on  L/D 
and  Zq,  both  the  inductive 
reactance,  Xa,  at  reso- 
nance and  the  equally 
negative  capacitive  reac- 
tance, Xca^  ^^^  ^'s*^  depen* 
dent  on  L/D  and  Zq.  Multi- 


plying   the    expression    in 

equation  2  by  co  =  27tf,  we 
get  the  simple  expression 
for  obtaining  XLa:  XLa  ~ 
hZo/4  -  07854Zo  = 
845.64  Ohms  (equation  4). 
[Knowing  Zq,  here  is  the 
other  check  method 
Vissers  could  have  used  to 
detect  his  reactance  error, 
which  also  confirms  that 
the  correct  antenna  reac- 
tance (Xa)  at  3.5  MHz  is 
around  110  Ohms,  not  55 
(when  resonant  at  3.75 
MHz).  This  method  uses 
the  well-known  expression 
Xa  =  -Zo  cot  1*^.  At  3.5 
MHz,  the  electrical  half 
length  i  =  90°  X  3.5/3 J5 
=  84*^.  Thus,  Xa  = 
-1076.7(cot  84^)  = 
-113.6  Ohms.] 

Antenna  Q  can  now  be 
determined  from  XLa  ^^d 
resonant  resistance  Ra  us- 
ing the  expression^  Q  = 
XLa/Ra(resonant)(equation 
5),  Observe  in  equation  4 
that  resonant  resistance  Rg 
(which  is  affected  by  prox- 
imity to  ground)  does  not 
appear  in  determining  the 
resonant  inductive  reac- 
tance XLai  thus  XLa  '5  inde- 
pendent  of  Ra^  However, 
since  XLa  ^t  resonance  is 
determined  by  L/D,  it  is  rel- 
atively constant,  having 
only  a  slight  variation  with 
height  above  ground.  In 
equation  5  we  see  that  Q  is 
dependent  on  XLa*  s^id 
also  varies  inversely  with 
the  value  of  R^  at 
resonance.  Since  R^  at 
resonance  varies  appre- 
ciably with  height,  decreas- 
ing as  height  decreases 
below  0.2 A,  Q  thus  in- 
creases as  the  antenna 
height  decreases.  Since  Q 
and  Ra  both  vary  with  an- 
tenna height,  we  can't  as- 
sume  to  know  the  value  of 
either  Q  or  Ra  at  some  ar- 
bitrary height  for  the  pur- 
pose of  determining  XLa^ 
unless  accurate  measure- 
ments of  both  Q  and  Ra  are 
taken.  Most  amateurs 
don't  have  the  equipment 
to  perform  these  measure- 
ments with  sufficient  preci- 
sion to  yield  a  good  value 
for  XLa-  And  herein  lies  the 


key  to  Mr.  Vissers'  error: 
He  has  implied  that  the 
assumptions  for  his  R^  and 
Q  were  based  on  his 
measurements.  Although 
his  assumption  of  Ra  =  40 
Ohms  is  realistic,  his  Q  — 
10  is  not,  because  this  com- 
bination yields  the  er- 
roneous XLa  "^  400  Ohms, 
a  value  that  can't  exist  with 
an  L/D  ratio  of  1 0,71 4  at 
3.75  MHz.  However,  since 
it  is  so  easy  to  determine 
the  accurate  length  and 
diameter  of  the  radiating 
element  why  not  obtain 
XLa  directly  from  L/D  as 
described  above?  This  way 
we  avoid  the  uncertainties 
accompanying  any  at- 
tempt to  determine  XLa 
from  Ra  and  Q.  So  let's 
now  correlate  some  perti- 
nent values  based  on  the 
correct  value  of  XLa  (846 
Ohms,  obtained  earlier 
from  L/D),  which  will  em- 
phasize the  importance  of 
obtaining  the  correct  value 

of  XLa*  if  calculations 
based  on  this  value  are  to 
have  validity. 

Why  a  Q  of  10  Is  Incorrect 

The  resonant  resistance 
Ra  of  our  RG-58  coaxial 
dipole  in  free  space  with  an 
L/D  ratio  of  10,714  is  72 
Ohms  (73.13  Ohms  when 
L/D  =  oo^  see  KingO,  and 
the  value  of  XLa  f^om 
equation  4  is  846  Ohms. 
Thus,  from  equation  5,  the 
free-space  Q  of  the  dipole 
is  846/72  =  11.75.  How^ 
ever,  when  the  antenna  is 
at  a  height  where  Ra  is 
reduced  to  40  Ohms,  the  Q 
increases  to  846/40  = 
21.15,  in  contrast  to  Mr. 
Vissers'  value  of  10.  On  the 
other  hand,  if  this  arbi- 
trarily-chosen Q  of  10  were 
realistic  with  an  Ra  =  40, 
the  value  of  XLa  really 
would  be  400  Ohms. 
However,  this  Q  of  10 
would  have  come  from  a 
free-space  Q  =  10  X  40/72 
=  536,  which  defines  an 
entirely  different  antenna. 
In  fact,  as  stated  earlier,  a 
value  for  XLa  ^^  ^00  Ohms 
at  3.75  MHz  requires  that 
diameter  D  =   3.1   inches. 


184 


22  times  thicker  than  that 
of  RC-58/U,  for  an  L/D  ^ 
487.  To  use  Mr.  Vissers' 
own  words,  that  is  a  big  dif- 
ference! 

Elfect  of  Height  on 
Antenna  Q 

The  subject  of  antenna 
height  and  its  effect  on  Q  is 
another  area  of  concern  in 
the  7^  Magazine  article,^ 
because  two  conflicting 
concepts  appear  that  are 
rather  puzzling.  On  one 
hand,  he  used  the  expres- 
sion Q  —  XLa/l'a  (^^^L'^^'^'i 
5),  and  its  inversion  XLa  ^ 
Ra  ^  Qi  which  state  cor- 
rectly that  when  R^ 
decreases,  Q  increases.  On 
the  other  hand,  ''after 
much  thought"  concerning 
the  results  of  his  measure- 
ments, he  concluded  that 
because  of  the  unavoid- 
able losses  incurred  when 
the  antenna  is  near  ground, 
the  Q  is  lower  than  when 
the  antenna  is  in  free 
space.  This  conclusion  is 
puzzling,  because  it  is  well 
known  that  when  dipole 
height  is  less  than  0.2A,  the 
antenna  resistance,  Rg,  is 
less  than  the  free-space 
value.  Since  equation  5 
shows  that  Q  varies  in- 
versely with  Ra,  antenna  Q 
near  ground  becomes 
higher  than  the  free-space 
value,  rather  than  lower. 
This  discrepancy  in  his  con- 
clusion, and  the  erroneous 
assumption  that  Q  =  10, 
raises  serious  questions 
concerning  the  measuring 
equipment,  technique,  and 
evaluation  of  the  data. 

Now,  the  matter  in  which 
Ra  changes  with  height 
over  actual  ground  {in  con- 
trast to  perfectly-conduct- 
ing ground)  is  complicated 
by  several  factors,  in- 
cluding the  dissfpative 
losses  he  mentioned  How* 
ever,  the  actual  value  of  Ra 
is  determined  by  the  in- 
tegrated effect  of  all  the 
contributing  factors  in  any 
given  set  of  ground-prox- 
imity  conditions.  Thus  the 
value  Ra  —  40  Ohms  in- 
cludes the  effect  of  these 
losses,    and    Ra    ^nd    XLa 


determine  the  Q  actually 
existing  under  those  condi* 
lions.  On  the  other  hand,  if 
the  ground  were  perfectly 
conducting,  the  mutual 
coupling  between  the  an- 
tenna and  its  ground- 
reflected  image  would  be 
greater  for  the  same 
height,  due  to  the  absence 
of  the  ground  losses.  When 
height  is  less  than  0.2A,  this 
larger  coupling  results  in  a 
lower  value  of  Ra,  and  a 
correspondingly  higher  Q 
than  when  the  antenna  is 
over  actual  ground. 
Perhaps  he  really  meant 
that  because  of  the 
ground-associated  losses, 
the  Q  of  an  antenna  over 
actual  ground  is  lower  (and 
the  Ra  higher)  than  //  it 
were  over  perfectly-con- 
ducting ground.  In  any 
event,  the  Q  of  an  earth- 
oriented  antenna  is  higher, 
not  lower,  than  the  same 
antenna  in  free  space. 
Thus,  it  is  not  true  that  "be- 
cause earth-oriented  an- 
tennas  have  a  lower  Q" 
they  yield  a  greater  degree 
of  bandwidth  improve- 
ment using  shunt-stub 
compensation  than  those 
in  free  space. 

Ignoring  Feedline  Attenua- 
tion Spells  Trouble  in  Fig*  9 

Let's  now  examine  Fig.  9, 
which  is  called  the  'proof 
of  the  pudding  "  The  exper- 
imental data  of  Fig,  9  is 
said  to  prove  that  the  co- 
axial dipole  is  working, 
because  it  is  said  to  cor- 
relate with  the  theoretical 
data  of  Fig.  8  (which  we 
have  shown  to  be  er- 
roneous), and  because  "it 
indicates  that  the  swr  im- 
provement is  even  better 
than  the  calculations  pre* 
dieted."  Unfortunately, 
Fig.  9  provides  no  such 
proof  On  the  contrary.  Fig. 
9  reveals  that  he  shares  a 
widespread  misconception 
concerning  the  correlation 
between  theoretical  and 
practical  aspects  of  anten- 
na systems  evaluation.  In 
reality,  the  graph  in  Fig.  9 
proves  only  that  the  swr 
values    shown    are    those 


measured  at  the  input  to  a 
feedline,  and  that  some 
amount  of  change  in  swr  at 
the  load  (antenna)  resulted 
from  changing  the  stub 
conditions.  Regardless  of 
the  caption,  the  graph 
reveals  no  quantitative 
data  whatever  concerning 
swr  at  the  antenna, 
because  the  true  dipole 
swr  values  are  masked  by 
an  unknown  feedline  atten- 
uation between  the  line  in- 
put and  the  antenna  ter- 
minals. It's  like  trying  to 
identify  a  pea  beneath  a 
mattress,  because  we  know 
both  from  the  corrected 
calculated  data  and  from 
measurements  that  the 
true  values  of  dipole  swr 
are  nearly  2Vi  times  larger 
than  those  shown  in  Fig,  8. 

Necessity  for  Line-Attenu- 
ation Data 

If  the  swr  is  measured  at 
the  feedline  input  simply 
to  ascertain  transmitter 
loading  conditions,  then 
Irne-attenuation  data  is  un- 
necessary. On  the  other 
hand,  if  the  line-input 
measurements  are  for  as- 
certaining the  matching 
conditions  at  the  antenna, 
then  feedline-attenuation 
data  is  absolutely  essen- 
tial. The  attenuation  data 
is  needed  to  obtain  the 
input-output  proportionali- 
ty factor  required  to 
calculate  the  magnitude  of 
the  reflection  coefficient 
[mismatch)  at  the  load 
from  that  measured  at  the 
input.  But  no  attenuation 
data  is  given  for  the  curves 


in  Fig.  9,  Thus  the  numbers 
on  the  scale  labeled 
"MEASURED  SWR"  are 
meaningless  with  respect 
to  swr  at  the  antenna, 
because  their  mathemat- 
ical relation  to  the  antenna 
terminals  is  unknown.  If  the 
line  attenuation  were  zero 
[which  it  isn't),  then  the 
curves,  as  labeled,  would 
represent  the  true  swr 
values  of  the  antenna.  On 
the  other  hand,  if  the  atten- 
uation were  2-06  dB>  then 
the  2.85:1  swr  of  curve  A  at 
3-5  MHz  would  represent 
the  recalculated  7.75:1  swr 
appearing  at  the  antenna 
terminals.  Thus,  to  indicate 
swr  at  the  antenna,  the 
scale  factor  of  the 
"MEASURED  SWR''  scale 
must  be  tailored  to  fit  the 
line  input-output  propor- 
tionality factor  obtainable 
only  from  the  line  attenu- 
ation. A  procedure  for  ob- 
taining this  proportionality 
factor  IS  outlined  (with 
solved  examples)  in  Appen- 
dix 4  of  my  analysis  in  Ham 
Radio.^ 

The  data  in  Table  1  illus- 
trates the  necessity  of  at- 
tenuation data,  showing, 
for  example,  that  by  simply 
increasing  the  line  attenu- 
ation from  2.06  to  3.18  dB, 
a  2.85:1  swr  would  still  ap- 
pear at  the  feedline  input 
with  the  far  end  either 
short  circuited,  or  left  open 
circuited.  In  other  words, 
by  measuring  at  the  line  in- 
put, one  could  not  distin- 
guish between  the  separate 
loads  of  either  zero  Ohms 
or    an     infinitely-high 


With  Line 
Attenuation 

0.0  d8 

0.25 

0.5 

1.0 

1.5 

2.0 

2.06 

3.0 

3.18 

4.0 

5.0 


Swr  at  Line  Input 

When  Load  Z|_  = 

When  Load  Zl  =  SC  (0  Ohms)  or 

40)1 08  Ohms  OC  ("  Ohms) 
7J5 

6,36  34.a 

5.40  17.4 

4.17  8.7 

3.41  5,85 
2.90  4.42 

[2.85]  4.30 

2.26  30 

2.18  {2.85) 
1.B9  2,32 
1.64  1.92 


Table  1.  SC  =  short  circuit;  OC  =  open  circa h. 


185 


resistance. 

Murphy  Nearly  Scored,  but 
Two  Wrongs  Don't  Make  a 
Right 

The  fortuitous  similarity 
of  the  incorrect  theoretical 

data  in  Fig.  8  and  the 
meaningless  measured 
data  in  Fig,  9  is  unfortunate 
and  misleading  because, 
for  those  unfamiliar  with 
the  effects  of  line  attenu- 
ation, the  comparison  of 
these  figures  supports  the 
widespread  misconception 
that  measurements  at  the 
line  input  directly  indicate 
conditions  at  the  antenna. 
And  indeed,  this  mis- 
conception trapped  Mr, 
Vissers  into  the  most  cata- 
strophic error  in  his 
coaxial-dipole  projects, 
because  it  misled  him  to 
believe  that  his  stubs  were 
performing  well,  even 
though  they  were  perform- 
ing as  described  in  my  Ham 
Radio  analysis.  By  ignoring 
the  effect  of  feedline  at- 
tenuation, the  accidentai 
agreement  between  the 
low-swr  values  of  Fig.  9 
measured  at  the  line  input 
and  the  unsuspected,  in- 
correct, theoretical  anten- 
na swr  data  in  Figs.  3  and  8, 
misled  him  to  believe  that 
both  graphs  were  correct 
and  valid  antenna  terminal 
data,  and  that  the  mea- 
sured data  supported  the 
theoretical  data.  On  the 
contrary,  if  he  had  cal- 
culated in  the  effect  of  the 
feedline  attenuation  on  the 
line-input  swr  values  of  Fig. 
9,  he  would  have  obtained 
values  of  dipole  swr  that 
are  vastly  greater  than 
those  of  Fig.  8  at  the  corre- 
sponding frequencies.  This 
discrepancy  would  have 
alerted  him  to  go  back  and 
find  the  initial  error  (the 
wrong  value  of  Xl^}  in 
calculating  the  Fig  8  data. 
This  is  the  second  oppor- 
tunity at  which  the  error 
could  have  been  detected. 
Had  the  error  been  de- 
tected at  either  point,  the 
case  for  the  coaxial  dipole 
would  have  evaporated. 
Unfortunately,   it   is  fairly 


common  to  see  published 
curves  purporting  to  show 
measured  antenna  band* 
width  characteristics,  with- 
out providing  any  feedline 
attenuation  information. 
Such  curves  convey  no 
more  clues  to  truth  in 
antenna  performance  than 
Mr.  Vissers'  Fig.  9,  so  he  is 
not  alone. 

In  addition  to  line  at- 
tenuation, there  are  other 
factors  that  contribute  to 
misleading  indications 
when  measuring  swr  at  the 
line  input  More  often  than 
not,  swr-indicator  readings 
are  somewhat  lower  than 
the  real  swr  values  appear- 
ing at  the  line  input  And 
with  the  coaxial  dipole,  the 
externa!  dielectric  cover- 
ing on  the  coax-cable 
radiator  causes  a  mild  in- 
crease in  antenna  band- 
width, from  the  combina- 
tion of  increased  antenna 
capacity  Ca  and  addi- 
tional  ohmic  loss  due  to 
dissipation  in  the  dielec- 
tric. (I  raised  this  point  in 
QSr^)  These  factors  make 
it  impossible  to  calculate 
the  true  terminal  im- 
pedance and  swr  of  the 
dielectric-covered  dipole 
[for  Fig,  8)  with  any  degree 
of  certainty,  although  the 
swr  is  certain  to  be 
somewhat  less  than  the 
7.75:1  that  we  calculated 
previously  for  a  bare  wire 
of  D  —  0,14  inches.  The 
best  way  to  find  out  for 
sure  is  to  determine  the  at- 
tenuation of  the  feedline 
used  in  obtaining  the  data 
for  Fig.  9,  re-measure  the 
data  with  an  accurate  im- 
pedance bridge,  and  then 
perform  the  calculation  to 
transfer  the  swr  values  at 
the  feedline-input  ter- 
minals to  the  antenna  ter- 
minals. 

Impedance  Relations  in 
Free  Space  Versus  Near 
Earth 

Let's  now  return  to  the 
discyssion  concerning  the 
effect  of  free-space  versus 
near-earth  conditions  in  re- 
lation to  antenna  imped- 
ance   and    bandwidth,    to 


discover  why  Mr.  Vissers' 
belief  that  the  coaxial 
dipole  performs  better 
near  earth  is  erroneous  He 

agrees  with  the  conclusion 
in  my  analysis  that  the 
reactance  shunting  used  in 
the  coaxial  dipole  is  inef- 
fective for  increasing  band- 
width when  the  dipole  is  in 
free  space  and  fed  with 
50-Ohm  feedline.  How- 
ever, he  believes  this 
technique  is  effective  with 
lower  antenna  resistance, 
R^,  as  found  in  80  meter 
antennas  at  normal 
heights.  Unfortunately,  in 
expecting  an  improvement 
in  the  broadbanding  capa- 
bilities of  reactance  shunt- 
ing by  reducing  resistance 
Ra  from  the  free-space 
value  of  72  Ohms  to 
around  40  Ohms,  he  is 
overlooking  two  basic  prin- 
ciples  of  impedance 
matching,  one  underlying 
the  shunt-reactance  meth- 
od of  increasing  the  band- 
width, and  the  other  con- 
cerning the  minimum-swr 
resistance  in  a  complex 
load  impedance.  The  vital 
aspects  of  the  shunt-reac- 
tance method  that  were 
overlooked  are  disclosed 
in  my  Ham  Radio  analysis^ 
(page  50),  and  the  mini- 
mum-swr resistance  princi- 
ple is  described  in  a  paper  I 
published  in  QST.*  How- 
ever, the  following  discus- 
sion may  be  helpful  in 
clarifying  the  conflict. 

In  the  conventional 
method  of  matching,  an- 
tenna resistance  Ra,  at  re- 
sonance, is  usually  nearly 
equal  to  the  line  im* 
pedance,  Zc  Typically,  Ra 
can  be  anywhere  from  40 
to  72  Ohms  when  Zq  —  50 
Ohms  (a  1.4:1  mismatch  is 
considered  insignificant). 
With  this  nearly  one-to-one 
ratio  between  the  line  and 
load  impedances  at  reso- 
nance, the  mismatch  rises 
continuously  on  either  side 
of  resonance,  because  the 
ratio  between  the  two  im- 
pedances increases,  due  to 
the  increasing  reactance, 
Xg.  Now  if  we  simply  add 
reactance  shunting  to  the 


antenna  terminals  to  can- 
cel the  antenna  reactance, 
the  shunt  reactance  cannot 
perform  effectively  in  re- 
ducing the  mismatch  off 
resonance,  as  long  as  the 
impedance  ratio  is  already 
nearly  one-to-one  at  reso- 
nance. The  reason  is  be- 
cause the  shunt  reactance 
cannot  yield  a  significant 
reduction  in  the  off- 
resonant  antenna  imped- 
ance—  it  can  only  ex- 
change a  reactive  terminal 
impedance  for  a  nearly- 
equai  resistive  impedance. 
Thus  the  impedance  ratio 
remains  high,  and  as  I  ex- 
plained in  the  analysis ' 
and  illustrated  with  a 
numerical  example  in 
QST,^  when  the  feedline-to- 
antenna  impedance  ratio  is 
high,  the  mismatch  is  near- 
ly the  same  whether  the 
antenna  terminal  imped- 
ance is  reactive  or  resis- 
tive. Thus  the  shunting  is 
ineffective,  as  shown  in 
Fig.  10B  in  my  analysis,  and 
in  Fig,  1  in  this  article. 

On  the  other  hand,  con- 
sider the  relationship 
where  the  feedline-to-an* 
tenna  impedance  ratio  is 
within  the  range  where  the 
shunt-reactance  method 
can  perform  effectively- 
By  using  a  feedline  of 
higher  impedance,  in- 
creased  by  a  factor  of  two- 
to-one  or  more  (and  ac- 
cepting a  similar  com- 
promise in  mismatch  at 
resonance),  the  ratio  be- 
tween the  reactive  off-res- 
onant  antenna  impedance 
and  the  line  impedance  is 
reduced  proportionally. 
With  this  lower  off-res- 
onance impedance  ratio, 
the  exchange  of  a  reactive 
load  impedance  for  a  resis- 
tive impedance  resulting 
from  the  reactance  shunt- 
ing now  yields  a  significant 
reduction  of  off-resonance 
mismatch,  as  Fig  4  of  my 
analysis  shows. 

The  Crucial  Factor  in  the 
Resistance  Versus  Off* 
Resonance>Mismatch  Reia- 
tionship 

The  crucial  factor  in  this 


186 


relationship  is  this:  The 
vital  reduction  of  the  off- 
resonant,  Itne-to-antenna 
impedance  ratio  obtained 
bv  increasing  the  line  im- 
pedance cannot  be  du pli- 
cated by  reducing  the  an- 
tenna resistance  Ra  unless 
the  antenna  reactance  Xa 
is  also  reduced  proportion- 
ally, because  it  is  mainly 
the  off-resonance  reac- 
tance that  causes  the  high 
antenna  impedance.  Natu- 
rally this  inherent  reac- 
tance cannot  be  reduced 
unless  the  radiator  itself  is 
redesigned.  So  when  the 
resistance  is  reduced 
without  also  reducing  the 
reactance,  the  off- 
resonance  impedance  rela- 
tionship is  entirely  dif- 
ferent from  that  obtained 
by  increasing  the  line  im- 
pedance. 

To  discover  how  reduc- 
ing only  the  resistance  Ra 
affects  mismatch,  let's  ex- 
periment with  a  dipole, 
Starting  with  R^j  —  72 
Ohms  at  resonance,  we'll 
make  a  series  of  frequency 
excursions  to  the  ends  of 
the  band,  and  at  each  suc- 
cessive excursion  we'll 
reduce  only  the  resistance, 
so  that  all  values  of  Ra  ver- 
sus frequency  are  lower 
than  those  of  the  preceding 
excursion.  The  result  is  that 
at  any  frequency  where  the 
swr  exceeds  about  2:1,  the 
mismatch  and  swr  become 
LARGER  as  the  resistance 
becomes  LOWER.  And  the 
greater  the  swr,  the  less  im- 
provement reactance 
shunting  can  provide,  for 
the  reason  explained 
earlier.  So  while  the 
mismatch  improvement  by 
reactance  shunting  is 
already  insignificant  when 
Ra  =  72  Ohms  (as  Mr. 
Vissers  agrees),  it  becomes 
worse  when  Ra  —  40 
Ohms,  not  better. 

It  is  true  that  reducing 
the  resonant  antenna 
resistance  from  72  to  40 
Ohms  improves  the  in- 
herent match  slightly  in  the 
region    near    resonance 


{from  1.44  down  to  1.25:1). 
However,  this  is  not  the 
region  where  mismatch 
reduction  is  needed;  the 
reduction  is  needed  in  the 
regions  toward  the  band 
ends,  where  the  inherent, 
uncompensated  swr  ex- 
ceeds 2:1,  and  it  is  in  these 
regions  where  Mr,  Vissers' 
theory  fails,  and  where  the 
shunt-reactance  method 
cannot  provide  significant 
improvement  for  a  thin 
dipole  when  fed  with  a 
50-Ohm  feedline. 

The  relationship  be- 
tween resistance  and  off- 
resonance  mismatch  is 
shown  in  Fig.  1  (a  graph 
from  data  of  Table  2,  which 
will  be  explained  shortly), 
where  we  can  see  the 
significant  difference  in 
the  way  dipole  swr  changes 
between  frequencies  near 
resonance  and  those 
nearer  to  the  band  edges, 
depending  on  whether  the 
antenna  resistance  Ra  at 
resonance  is  52  Ohms  or 
the  free-space  value  of  72 
Ohms.  With  the  52  Ohm 
antenna  the  match  is  near- 
ly perfect  at  resonance, 
and  thus  remains  some- 
what better  than  the 
72-Ohm  antenna  out  to 
around  a  2:1  swr.  However, 
at  frequencies  where  the 
swr  is  greater  than  1.7:1 
below  resonance,  and  2.2:1 
above  resonance,  the 
match  is  consistently 
worse  with  the  52-Ohm 
antenna.  From  calcula- 
tions not  shown  in  Table  2, 
the  match  quality  of  an 
antenna  having  a  40-Ohm 
resonant  Ra  deteriorates 
much  more  rapidly  than 
the  52-Ohm  antenna,  espe- 
cially near  the  band-edge 
frequencies  where  we  need 
the  mismatch  reduction 
the  most. 

The  Basis  for  the  Graphs 
and  Tables 

The  swr  values  appear- 
ing in  Fig.  1  and  Table  2 
were  calculated  from  the 
terminal  impedances  of 
both  a  free-space  and  an 
earth-oriented  dipole,  with 


%'0 


2 

10 


4 

SO 


0     it     1*      16      18     ?0    22  2* 

^0     40       ^Q     BO      fO      80      90    lOO     MO  120 


Fig,  2, 


three  different  stub- 
matching  conditions  for 
each:  1)  no  stubs;  2) 
25-Ohm  stubs;  and  3)  op- 
timum stubs.  To  make  a 
valid  comparison  of  the 
mismatches  associated 
with  these  different  stub 
conditions  requires  au- 
thentic impedance  data. 
Because  dipole  resistance 
R^  changes  significantly 
with  frequency  [see  Table 
2),  it  is  improper  to 
calculate  the  mismatches 
using  a  constant  resistance 
Ra  =  40  Ohms  across  the 
band  (as  Mr.  Vissers  has 
done).  Therefore,  the  free- 
space  data  appearing  in 
Fig.  1  and  Table  2  is  authen- 
tic impedance  data  taken 
from  King/  the  same  as 
used  in  my  analysis.^ 

For  the  earth-oriented 
impedance  data,  resis- 
tance values  of  Ra  ~  20 
Ohms  were  selected  for 
each  corresponding  fre- 
quency, to  allow  for  the 
mutual  coupling  to  the  im- 
age dipole.  The  constant 
20-Ohm  difference  be- 
tween free-space  and 
earth-oriented  resistance 
versus  frequency  repre- 
sents only  a  small  com- 
promise with  the  actual 
change  in  mutual  re- 
sistance Rm  across  the 
band,  and  the  R^  — 
20-Ohm  values  closely 
represent  those  obtained 
with  the  reflection  coeffi 
cient  of  average  ground. 
Exceptionally  high  ground 
conductivity  beneath  the 
antenna  is  required  to  ob- 
tain values  much  less  than 
40  Ohms  anywhere  within 
the  band  at  any  height  us- 


ing a  straight  dipole, 
although  lower  values  can 
be  obtained  with  inverted- 
Vs  having  included  angles 
of  considerably  less  than 
180  degrees.  The  Ra  — 
2D-Ohm  values  include  68 
Ohms  at  4.0  MHz,  52  Ohms 
at  resonance,  down  to  38.5 
Ohms  at  3.5  MHz. 

At  average  80  meter 
antenna  heights,  the 
mutual  reactance  Xm  i^ 
small,  so  the  change  in  ter- 
minal  reactance  Xa 
with  height  is  negligible,  as 
confirmed  by  extensive 
measurements.  Therefore 
the  same  values  of  Xa  were 
used  in  both  the  free-space 
and  earth-oriented  condi- 
tions. Of  course,  earth- 
oriented  impedances  vary 
with  location.  However, 
the  impedances  selected 
as  previously  described  are 
typical  of  the  average 
amateur  situation,  and  are 
valid  for  demonstrating  the 
general  relationship  be- 
tween antenna  resistance 
and  mismatch  (both  with 
and  without  stubbing).  In 
other  words,  measured 
values  are  not  expected  to 
repeat  the  data  in  Table  2 
exactly,  but  in  general  the 
improvements  due  to  stub- 
bing will  be  fairly  propor- 
tional to  those  appearing  in 
Table  2.  It  should  be  kept 
in  mind,  as  explained 
earlier,  that  with  50-Ohm 
feed  line,  the  ratio  of  off- 
resonance  antenna-to- 
feedline  impedance  is  too 
high  for  the  stubbing  to 
have  a  significant  effect. 

However,  it  should  be 
clearly  understood  that  the 


187 


Table  2  values  showing  swr 
improvement  are  the 
precise  values  that  will 
result  strictly  from  the 
shunt  reactance  alone  for 
the  given  impedance  con- 
ditions—no greater  im- 
provement than  this  can  be 
obtained  from  the  shunting 
itself,  because  the  calcula- 
tions based  on  pure, 
lossless  reactance  yield 
precise  answers.  However, 
if  measured  values  do  in- 
dicate a  significantly 
greater  amount  of  im- 
provement than  shown  in 
Table  2  under  the  same 
conditions  of  uncompen- 
sated impedance,  it  means 
that  additional  phenomena 
are  also  contributing  to  the 
effect  obtained  with 
lossless  stubs.  Such  phe- 
nomena include  ohmic  loss 
of  the  stubs  which  we 
haven't  considered  {the  ac- 
tual stubs  aren't  lossless), 
and  the  effect  of  the  exter- 
nal dielectric,  which  is  a 
separate  contfibution  that 
is  practically  impossible  to 
predict  But  remember, 
any  such  "improvement" 
resulting  from  ohmic  loss 
represents  power  that  isn't 
radiated. 

The    Minimum-Swr-Resis- 
tance  Principle 

When  a  load  terminating 
a  feed  tine  is  resistive,  as  in 
an  antenna  operating  at 
resonance,  the  mismatch 
between  the  line  and  the 
load  impedances  is  found 
by  simply  dividing  the 
larger  impedance  by  the 
smaller.  However,  as  with 
all  amateur  antennas, 
when  the  load  is  the  com- 
plex impedance  Za  =  Ra 
+  jXa  of  an  antenna 
operating  off  resonance, 
the  relationship  between 
line  impedance  Zq  and  mis- 
match is  no  longer  a  simple 
one.  So  appreciation  of  the 
swr  values  in  Fig.  1  and 
Table  2  is  understandably 
difficult.  Directions  for 
calculating  the  swr  values 
are  outlined  in  Appendices 
1  and  2  of  my  analysis,^  but 
textbook  study  is  required 
for  an   in*depth   apprecia- 


tion of  the  concepts. 
However,  although  not 
well  known  among  ama- 
teurs, the  minimum-swr- 
resistance'  principle  pro- 
vides an  elegant  means  for 
correlating  complex  load 
impedance  with  feedline 
impedance  in  a  way  that 
provides  an  unusual  view- 
point in  appreciating  the 
effect  of  resistance  on  the 
match  quality  when  the 
load  contains  reactance. 
So  let's  examine  the 
minimum-swr-resi  stance 
principle. 

In  a  series  complex  load 
impedance,  Zl,  comprising 
a  resistance  R  and  reac- 
tance X,  if  the  resistance  is 
varied  but  the  reactance  is 
not,  there  is  a  single  value 
of  resistance,  Rmswrfcalled 
the  minimum-swr  resis- 
tance), that  will  cause  the 
load  to  produce  a  mini- 
mum  of  mismatch  when 
terminating  a  generator  or 
tine.  Unless  X  =  0,  Rmswr 
will  be  greater  than  the  line 
impedance  Zq.  When  the 
component  values  in  the 
load  are  normalized  to  the 
line  impedance  Zq 
(yielding  RIZq  —  r,  and 
X/Zc  =  x),  the  value  of  the 
normalized  minimum-swr- 
resistance  r^swr  ~  V^'  +  T 
(equation    6),'    When    the 

load  Zl  =  Rmswr  +  J^.  the 
mismatch  value  equals  the 
sum  of  the  normalized 
components  of   the   load; 

I.e.,  swr  =  rrnswr  +  ^ 
(equation  7).* 

This  principle  tells  us 
that  for  a  given  value  of  re- 
actance,  X,  in  a  load  in 
series  with  resistance 
Rmswr.  any  change  in 
resistance  (either  higher  or 
lower)  will  cause  the  swr  to 
rise.  For  example,  let's  find 

the  value  of  Rmswr  ^^^  3 
reactance  X  =  50  Ohms 
with  a  50-Ohm  line,  and 
compare  the  mismatch  the 
combination  produces 
with  the  mismatches  from 
two  other  impedances  hav- 
ing the  same  reactance, 
but  one  having  a  higher 
resistance  and  the  other  a 
lower  resistance.  Thus,  Zl 
=  Rmswr  +  JSO  Ohms,  and 


by  normalizing  becomes  z 
=  Rmswr  +  H  0.  The  value 
of  ^'mswr  (determined 
solely  from  x)  is  \/x'  +  1  = 
\/V  +  1  =  V^  =  1.414 
De-normalizing,  Rmswr  = 
50  X  r,414  =  70.71  Ohms, 
so  the  desired  impedance 
is  Zl  =  70.71  +  150  Ohms. 
The  swr  produced  by  this 
impedance  is  r^swr  +  x  = 
1  414    +    1    =    2  414,   the 

minimum-possible  swr 
when  X  =  Zc  =  50  Ohms. 
(This  treatment  works  only 
when  r  =  rnnswr)  Now,  us- 
ing the  expressions  from 
Appendices  1  or  2  in  my 
analysis^  to  calculate  the 
swr  produced  by  general 
complex  load  impedances, 
we  find  that  impedances 
Zl  =  50  +  j50  and  100  + 
jSO  both  yield  the  identical 
value  of  swr  =  2.618:1, 
which  is  higher  than  the 
minimum-possible  2.414:1 
produced  by  the  im- 
pedance 70.71  -h  j50 
Ohms.  Additional  calcula- 
tions  show  that  as  the 
resistance  goes  either 
lower  than  50  Ohms  or 
higher  than  100  Ohms,  the 
swr  continues  to  rise  above 
2.618:1.  For  example,  Zl  == 
25  +  jSO  yields  4.266:1, 
and  125  +  j50  yields 
2,962:1.  However,  note 
that  the  swr  rises  slowly  as 
R  increases  above  100 
Ohms,  but  rises  rapidly 
when  R  decreases  below  50 
Ohms, 

This  minimum^swr- 
resistance  principle  is  com- 
pletely general,  working 
for  any  value  of  reactance 
X  and  line  impedance  Zc, 
Thus  we  have  a  powerful 
tool  for  investigating  any 
complex  antenna-terminal 
impedance  Zg  as  the  load 
for  determining  which 
direction  the  swr  will  go 
with  a  change  in  resistance 
Ra.  Fig.  2  contains  a  plot  of 
Rmswr  versus  reactance  X 
(including  the  normalized 
values  for  x)  for  values  of  X 
from  zero  to  120  Ohms 
with  a  line  impedance  Zq 
of  50  Ohms,  For  conve- 
nience, the  corresponding 
minimum-possible-swr 
values  are  also  plotted.  To 


use  the  graph  in  determin- 
ing whether  the  swr  will 
rise  or  fall  with  a  given 
change  in  antenna  resis- 
tance Rfl,  we  first  deter- 
mine the  reactance  compo- 
nent Xa  of  the  antenna  im- 
pedance. From  either  the 
grapK  or  equation  6,  we 
then  find  the  correspond- 
ing  minimum-swr-resis- 
tance,  Rmswr-  1^  resistance 
Ra  is  lower  than  Rmswr^ 
raising  the  value  of  Ra  will 
reduce  the  swr  (until  Ra  = 
Rmswr).  stnd  vice  versa.  If 
Ra  is  higher  than  Rmswr^ 
raising  the  value  of  Rg  will 
increase  the  swr,  and  vice 
versa.  Since  Rmswr  *s  50 
Ohms  when  X  =  0,  Rmswr 
does  not  go  lower  than  50 
Ohms.  Thus  if  resistance 
Ra  is  less  than  50  Ohms,  in- 
creasing the  value  of  Ra 
will  decrease  the  swr  for 
whatever  the  value  of  reac- 
tance Xa,  including  Xa  — 
0.  However,  to  reach  the 
minimum-possible  swr 
when  any  reactance  is  pres- 
ent, resistance  Ra  must  be 
higher  than  50  Ohms,  and 
the  greater  the  reactance, 
the  higher  resistance  Rg 
must  be  raised. 

Verification  Using  the 
Minimum-Swr-Resistance 
Principle 

Turning  now  to  Table  2, 
the  values  of  minimum- 
5 w r- res i stance  Rmswr 
listed  there  tfrom  the  data 
of  Fig,  2)  are  the  values 
which  yield  the  lowest 
possible  mismatch  when  in 
series  with  the  correspond- 
ing reactance  X^  at  the  in- 
dicated frequency.  In  other 
words,  if  resistance  Rmswr 
for  the  corresponding  reac- 
tance were  to  replace  the 
actual  antenna  resistance 
Ra.  we  would  obtain  the 
lowest  swr  that  is  possible 
with  that  particular  reac- 
tance Xa  in  the  circuit,  The 
values  of  the  correspond- 
ing minimum-possible  swr 
are  also  listed  in  Table  2. 

In  using  this  technique 
to  confirm  our  previous 
conclusions  based  on 
calculated  values  of  swr, 
let's  first  examine  the  con- 


188 


Mismatch 

or  Swr 

FmHz 

Antenna  Imped 

ance 

Uncompensated 

Compensated 

Compensated 

Components' 

dlpofe 

wHh  2SQ 

wrth  opt 

[imum 

stubs 

stubs 

Ohms 

Ohms 

Ohms 

Mia.* 

Free- 

Near- 

Free- 

Near* 

Free- 

Near- 

Resistance 

React. 

Resis. 

Possible 

Space 

Earth 

Space 

Earth 

Space 

Earth 

"a 

Ra'20 

Xa 

Rmswr 

Swr 

Ra 

Ra20 

Ra 

Ra'20 

Ra 

Ra'20 

3.5 

58.5 

38.5 

-103.00 

119.0 

4.54 

5.84 

8.00 

5.50 

7.50 

5,16 

6.83 

3.55 

60.8 

40.8 

•86  50 

99,9 

3J3 

4,27 

5.53 

4.04 

5.19 

3.71 

4.58 

36 

63,4 

43.4 

-64.79 

81.8 

2,93 

3.05 

368 

2.92 

3.49 

2,67 

3,03 

3.625 

64.75 

44.75 

-53.94 

73.55 

2.55 

2.58 

2,98 

365 

66  J 

46.1 

-43.08 

66.0 

2.18 

2.18 

2.39 

2.12 

2.30 

1.97 

2.03 

3.675 

67.6 

47.6 

-32.24 

59.5 

1.83 

1.86 

1.92 

3.69 

68.5 

48.5 

-25.74 

5624 

1.64 

1.70 

1.68 

3.7 

69.1 

49.1 

-21.40 

54.4 

1.52 

1.62 

1,54 

1.60 

1.50 

1.54 

1.38 

3.75 

72.0 

52.0 

0 

50.0 

1.00 

1.44 

1.04 

1.44 

1,04 

1.44 

1.04 

3.8 

75:1 

55.1 

21.92 

54.6 

1.53 

1.71 

1.53 

1 .69 

1.50 

1.69 

1,49 

3.825 

76.6 

56.6 

32.80 

59.8 

1.85 

1,95 

1.86 

3,85 

78.2 

58,2 

43.58 

66.3 

2,20 

2.24 

2.23 

2.19 

2.15 

2.14 

2.05 

3.9 

81.3 

61.3 

65.24 

82.2 

2.95 

2.95 

3.11 

2.85 

2.97 

2.74 

2.77 

3.95 

84.8 

64.8 

87.15 

100.5 

3.75 

3.81 

4.17 

3.61 

3.96 

3.51 

3.69 

4.0 

88-0 

68.0 

109.24 

120.1 

4.59 

4.83 

5.42 

4.61 

5.13 

4.47 

4.87 

Table  2. 


ditfons  at  3.825  MHz.  At 
this  frequency  the  lower- 
height  (Ra  -  20,  or 
52-Ohm}  antenna  yretds  a 
slightly  better  match  near 
resonance  because  its 
52-Ohm  resonant  resfs- 
tance  is  nearer  to  the 
50-Ohm  line  impedance 
than  the  72*Ohm  free- 
space  antenna,  From  Table 
2.  at  3.825  MHz,  Xa  =  32.8 
Ohms,  and  the  minimum- 
swr-resistance  Rmswr  — 
59.8  Ohms.  If  the  actual 
resistance  Ra  ^  20  were 
59.8  Ohms,  the  swr  would 
be  1,85:1,  the  lowest  swr 
possible  with  32.8  Ohms  of 
reactance  in  the  circuit. 
However,  at  this  frequency 
the  actual  resistance  R^  — 
20  —  56.6  Ohms  nearly 
equals  the  minimum-swr 
resistance,  yielding  a  1.86:1 
swr  for  the  52-Ohm  anten- 
na (only  slightly  higher 
than  the  minimum),  in  con- 
trast to  the  higher 
value  Ra  =  76,6  Ohms  for 
the  free-space  antenna, 
with  a  1.95:1  swr.  This  ex- 
plains why  the  52-Ohm 
antenna  yields  a  slightly 
better  match  than  the 
72-Ohm  antenna  at  this  fre- 
quency. 

On  the  other  hand,  at  3.5 
MHz  the  minimum-swr- 
resistance  technique 
demonstrates  rather 
dramatically  why  the  off- 
resonance    mismatch    in- 


creases when  the  antenna 
resistance  at  resonance  is 
reduced  Again  from  Table 
2,  at  3,5  MHz  the  reactance 
Xa  =  -108  Ohms  is  shown 
to  require  a  resistance 
Rmswr  of  119  Ohms  to  ob- 
tain the  lowest-possible 
swr,  which  is  4,54:1,  The 
free-space  and  near-earth 
dipole  resistances  at  3.5 
MHz  are  58.5  Ohms  and 
38,5  Ohms,  respectively. 
Thus,  the  free-space 
resistance  is  60.5  Ohms 
below  the  optimum  119 
Ohms,  which  increases  the 
swr  to  584:1.  However, 
with  the  38,5-Ohm 
resistance  of  the  near-earth 
antenna,  the  swr  has 
soared  to  8,0:1,  because 
the  38.5-Ohm  resistance  is 
20  Ohms  lower  yet  than  the 
free-space  value,  or  80.5 
Ohms  below  the  optimum 
value.  Now,  since  the  free- 
space  value  of  58-5  Ohms 
is  already  60.5  Ohms  below 
the  optimum  value  of 
Rmswr  «^f  119  Ohms,  it  is 
clearly  evident  that  to  ob- 
tain a  lower  swr  than  the 
free-space  value  of  5.84:1, 
the  resistance  Ra  must  be 
increased,  rather  than 
decreased.  Moreover,  an 
examination  of  all  remain- 
ing data  points  listed  in 
Table   2    reveals   that   the 

values    of    Rmswr    ^"^ 

minimum-possible  swr  con- 
firm the  direction  in  which 


every  value  of  dipole  swr 
changed  resulting  from  a 
corresponding  change  in 
dtpole  resistance  Ra. 

As  an  additional  point  of 
interest,  compare  the 
curves  appearing  in  Fig.  8 
of  the  73  Magazine  article* 
with  those  of  my  Fig,  1,  and 
note  the  asymmetric  shape 
of  my  swr  curves  with 
respect  to  the  center  fre- 
quency of  3,75  MHz.  While 
the  (  +  )  and  {  — )  reac- 
tances,  X^,  are  almost  sym- 
metrical [see  Table  2\  the 
values  of  swr  below  center 
are  higher  than  those  at  the 
same  difference  in  fre- 
quency above  center.  The 
reason  is  that  resistance  Ra 
is  decreasing  below  center, 
and  increasing  above,  and 
the  swr  values  are  simply 
following  the  minimum- 
swr-resistance  principle. 
On  the  contrary,  the 
Vissers  curves  are  unreal- 
istically  symmetrical, 
because  in  his  swr  calcula* 
tions  the  constant  value  Ra 
=  40  Ohms  was  used 
(incorrectly)  across  the  en- 
tire band. 

Conclusion 

In  comparing  the  swr 
curves  of  the  72-Ohm  and 
52-Ohm  antennas  in  my 
Fig.  1,  it  is  evident  that  no 
great  dramatic  difference 
exists  between  them. 
However,  these  two  curves 


represent  the  effect  of  the 

"big  difference"  that  was 
asserted  to  exist  between 
my  free-space  72-Ohm 
dipole  and  a  dipole  near 
earth.  This  is  the  "big  dif- 
ference" that  was  pre- 
dicted would  change  the 
insignificant  stub  contribu- 
tion in  my  "irrelevant" 
free-space  coaxial  dipole 
into  a  workable,  worth- 
while contribution  by 
"bringing  the  dipole  down 
to  earth/'  Obviously,  the 
dramatic  change  that  was 
predicted  doesn't  materi- 
alize, and  the  positions  of 
the  curves  in  my  Fig.  1  in- 
deed show  that  the  dipole 
near  earth  is  even  less  ef- 
fective than  when  in  free 
space.  Thus,  despite 
Vissers'  statement  to  the 
contrary,  these  curves 
more  than  justify  the  use  of 
free-space  data  in  my 
analysts  that  enables  the 
amateur  to  recognize  the 
conditions  under  which  the 
stubs  in  a  coaxial  dipole 
will  or  will  not  provide  a 
worthwhile  improvement 
in  bandwidth. 

Perhaps  not  everyone 
will  agree  on  just  what  con- 
stitutes a  worthwhile, 
significant  improvement  in 
swr.  So  if  anyone  decides 
the  meager  improvement 
shown  in  Fig.  1  and  Table  2 
is  worth  the  constructional 
effort  and  cost  required  to 


109 


obtain  it  with  shunt  stubs, 
fine  and  dandy.  But  if  you 
appear  to  be  measuring 
considerably  more  band* 
width  at  the  antenna  than 
indicated  in  Fig,  1,  you  are 
quite  likely  to  be  fooling 
yourself.  Remember  that 
unwanted  ohmic  losses 
can  raise  an  otherwise-low 
terminal  resistance,  thus 
reducing  the  swr  via  the 
minimum-swr  principle, 
but  at  the  expense  of  losing 
power  to  heat.  In  any  case, 
as  a  professional  antenna 
engineer,  my  boss  would 
hand  me  my  head  on  a  plat- 
ter within  seconds  if  I 
seriously  presented  him 
with  this  shunt-stub 
method  as  a  viable  solu- 
tion to  the  80  meter  broad- 
banding  problem  when  us- 
ing 50-Ohm  feed  line.  ■ 

Addendum 

Mr  Vissers  raised  an  im- 
portant point  concerning 
Borton's  work,'  in  that  my 
analysis  failed  to  mention 
the  swr  differences  Borton 


obtained  between  a  coax- 
ial dipole  and  the  bow-tie 
antenna  constructed  from 
galvanized  wire.  There  are 
two  reasons  why  I  omitted 
reference  to  this  topic: 
First,  my  article  was 
already  too  long.  More  im- 
portantly, several  cloudy 
issues  concerning  both  of 
these  antenna  forms  need 
clarifying  before  I  can 
discuss  them  knowledge- 
ably. 

For  example,  in  the  coax- 
ial dipole:  What  precise, 
quantitative  effects  result 
from  the  external  dielectric 
covering?  Well,  Zq.  XLa, 
and  Q  are  all  reduced  by 
the  resulting  increase  in 
antenna  capacitance  Ca. 
But  how  much?  Does  this 
yield  an  efficient  increase 
in  bandwidth?  And  how 
much  does  the  dielectric 
covering  increase  the 
dissipation  loss,  reducing 
the  efficiency  while  raising 
the  terminal  resistance  and 
reducing  the  swr?  As  I 
stated  in  Q5T,^  further  in- 


Choosy  Feogle 
PVE  SiandaraT 


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vestigation  is  necessary^ 

Concerning  the  galva- 
nized wire,  the  higher 
resistance  of  the  zinc 
covering  is  probably  caus- 
ing the  lower  swr,  but  more 
investigation  is  required 
here  also:  What  is  the 
thickness  of  the  galvaniz- 
ing? Is  it  greater  than  the  rf 
skin  depth  at  4  MHz?  If  so, 
what  is  the  total  series  sur- 
face resistance  at  rf?  Com- 
pared to  copper?  Enough 
to  account  for  the  dif- 
ference in  swr?  Does  the 
magnetic  effect  of  the  iron 
in  the  wire  influence  the 
phase  velocity  of  the  rf 
wave?  So  far,  I  have  been 
unable  to  pursue  these 
questions.  I  had  planned 
future  collaboration  with 
Borton  for  f uther  investiga- 
tion into  the  rf  properties 
of  galvanized  iron  wire.  I 
regret  that  such  collabora- 
tion is  no  longer  possible, 
because  Dwight  Borton 
recently  became  a  silent 
key.  I  will  think  of  him  as  I 
proceed  alone. 


References 

1.  Walter  Maxweli  W2DU,  "A 
Revealing  Analysis  of  the  Co- 
axiat'Dipole  Antenna/'  Ham 
Radio,  August.  1978,  p.  46. 

2.  Walter  Maxwell  W2DU,  *'Th© 
Broad-Band  Double-Bazooka 
Antenna — ^How  Broad  ts  It?", 
QST.  September,  1976.  p.  29. 

3.  William  Vissers  K4KK  "Build 
A  Double  Bazooka  "  73  Maga- 
zine, August,  1977,  p.  36. 

4.  Jordan  and  Salmain,  Elec- 
tromagnetic  Waves  and  Radh 
afrng  Systems,  2nd  Edition^ 
Prentice-Hall,  Englewood  Cliffs 
NJ,  p,  548.  (Caution:  Values 
shown  are  for  monopolei  muith 
ply  by  2  for  dipole.) 

5.  fbid.,  p.  388. 

6.  SchelkunofI  and  Friis,  Anten- 
nas,  Theory  and  Practice^ 
Wiley,  1952,  pp.  436-455. 

7.  Ronold  W.  P.  King,  Theory  of 
Linear  Antennas,  Cambridge 
University  Press,  Cambridge 
MA.  p.  176. 

a  Walter  Maxwell  W2DU,  "An- 
other Look  At  Reflections." 
Part  5,  QST,  April,  1974,  p.  161, 
equation  11, 

9.  Dwight  Borton  W9VMQ, 
"Wide-Bandwidth  Bow-Tie  Ah* 
tenna  for  90  Meters/*  Ham 
Radio,  May;  1975,  p.  56. 


January  27-28, 1979 


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190 


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191 


The  Packet  Radio  Revolution 


pioneers,  take  note! 


! 


Editor's  Note:  Shortly  before  press  time,  the  Canadian  authorities  announced  the  creation  of  a  new  "Amateur  Digital  Radio  0|  ator's 
Certificate/'  a  no-code  license  allowing  certain  experimenter  privileges,  including  packet  radio,  \n  the  amateur  bands  above  '  t  MHz. 
Certain  portions  of  the  220  and  440  MHz  bands  hawe  been  reserved  exclusively  for  packet  transmissions. 


Robert  T.  Rouleau  VE2PY 
1050  Churchill 
Monireat,  Quebec 
Canada  HSR  3B6 


Not  with  a  bang,  but 
with  sort  of  a  swish, 
the  "packet"  revolution 
began.  On  May  31 ,1978,  the 
Montreal  Amateur  Radio 
Club  sent  the  first  amateur 
packets.  The  face  and  sound 
of  amateur  radio  will  never 
be  the  same  again.  Space- 
age  radio  arrived  for 
amateurs.  Our  communica' 
tions  will  be  faster,  more  ac- 
curate, more  reliable,  and 
use  less  spectrum. 

If  you  haven't  heard  of 
packet  radio,  don't  be  sur- 
prised.  It  is  new.  Don't  look 


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in  the  Handbook  or  your 
favorite  ham  magazine, 
either.  You'd  have  more 
luck  researching  doctoral 
theses  for  information. 
Right  now,  there  are  about 
two  dozen  packet  systems 
up  and  running  in  the 
world.  None  of  them  are 
amateur  and  none  of  them 
contemplate  the  number 
of  users  that  an  amateur 
radio  system  would. 

Packet  radio  is  a  name 
given  to  the  time-division 
multiplexing  of  a  radio 
channel.  Large  numbers  of 
users  can  share  one  chan- 
nel without  QRM  or  has- 
sles, Users  don't  even  know 
that  they  are  sharing  the 
channel  with  anyone  else. 
The    name    "packet"    is 


w 


RECEIVER 


TRANSMIT    , 


TRiVNSI^EiVER 


Fig,  7,  Block  diagram  showing  component  arrangement  of 
a  typical  packet  radio  station. 


192 


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derived  from  the  fact  that 
each  message  is  sent  in  a 
package.  It  has  three  parts: 
the  address  and  return  ad- 
dress called  the  "header/' 
the  data  or  message  part 
and  the  ''trailer/'  which  is 
an  error-detection  scheme. 

You  can  compare  packet 
radio  to  a  sort  of  instant 
electronic  mail  service. 
Each  packet  is  a  postcard 
You  put  your  message  on 
the  card,  address  it.  and 
put  on  the  return  address. 
You  then  slip  it  in  a  mail 
slot  which  is  your  amateur 
radio  station.  If  your  mes- 
sage is  too  long  for  one 
postcard,  then  you'll  just 
send  a  series  of  them.  Once 
you  slip  it  in  the  mail  slot, 
the  system  delivers  the 
card  for  you,  or  if  it  can't,  it 
returns  the  card  automati- 
cally. 

How  can  so  many  users 
share  one  channel?  Speed. 
Packets  are  sent  from  25  to 
25,000  times  faster  than 
amateur  RTTY  Let's  com- 
pare packet  RTTY  to  the 
amateur   kind.  To  send  a 


one-line  message  on  60 
wpmTeletype^'^,  yi  j  need 
about  10  seconds,  and  no 
one  else  can  use  the  chan- 
nel. The  simple  packet 
system  we'll  see  later  only 
takes  1/4  of  a  second  to  do 
the  same  thing.  The  other 
9-3/4  seconds  could  be 
used  for  other  messages, 
up  to  40  of  them,  in  fact. 

How  does  it  go  so  fast? 
There  are  two  explana- 
tions. First,  instead  of  using 
the  channel  while  each  let- 
ter is  sent,  we  wait  until  the 
whole  line  is  complete  and 
send  it  in  a  burst.  Second, 
the  baud  rate  for  our  sys- 
tem is  2000  instead  of  45 
for  amateur  Teletype.  It 
also  fits  in  the  same  band- 
width! This  is  not  a  con- 
tradiction—we just  use 
better  modulation  schemes 
which  are  capable  of  send- 
ing more  information  in  the 
same  bandwidth. 

You  are  probably  saying, 
''Why  all  this  packet  non* 
sense?  It's  just  a  faster 
Teletype  setup."  Not  at  all ! 
You  haven't  heard  the  half 


of  it  yet.  The  good  part  is 
still  to  come.  Packets  are 
drgitally  encoded.  This 
means  that  anythrng  that 
can  be  "digitized"  can  be 
sent  in  the  packet:  voice, 
RTTY,  slow-scan,  televi- 
sion, telemetry  — you  name 
it  Packet  radio  encom- 
passes all  modes!  That's 
why  we  call  the  "message" 
part  of  the  packet  the  data. 
It  coutd  be  any  one  of  a 
million  things.  But,  that's 
not  all  the  good  stuff. 

Since  packets  are  in  a 
digital  format,  they  can  be 
read  and  understood  by 
simple  computers.  What  if 
we  had  a  microprocessor 
setup  at  a  VHF  repeater? 
The  repeater  could  read 
the  address  on  your  packet 
and,  if  it  was  out  of  town, 
switch  on  a  link  transmitter 
and  relay  it  towards  its 
destination.  Now  if  we  had 
microprocessor-controlled 
repeater  links  all  across  the 
country,  your  packet  could 
be  delivered  anywhere 
within  the  range  of  a  re- 
peater Packets  make  this 
kind  of  network  easy.  We 
are  now  working  on  the 
design  of  a  packet  net 
called  AMPAC  (amateur 
packet),  which  will  make 
this  possible.  Since  packets 
contain  an  error-detection 
scheme  at  the  end,  check- 
ing a  message  to  verify  that 
it  is  intact  is  easy.  If  the 
packet  was  damaged,  we 
could  ask  for  a  repeat 
automatically  if  our  ter- 
minals were  programmed 
to  do  so. 

Let's  took  at  a  few  of  the 
applications  for  packet 
radio.  On  the  HF  bands,  I 
bet  the  RTTY  operators 
would  like  to  have  a 
system  this  fast  which 
automaticaHy  calls  for 
repeats  of  packets  dam- 
aged by  QRM  and  fading. 
For  once,  the  copy  would 
be  clean  all  the  way.  The 
same  would  be  true  for  the 
slow-scan  TV  crowd.  The 
image  would  form  Irne-by- 
line  and  with  no  snow! 
Moonbouncers  already  use 
a  kind  of  burst  technique. 


Your  terminal  would  be 
programmed  to  send  a 
packet,  and  then  wait  a 
predetermined  length  of 
time  for  a  return  message. 
If  the  return  message 
didn't  come,  the  original 
message  would  be  repeat- 
ed until  it  did.  It  could  also 
log  the  callsigns  and  time 
that  transmission  was  com- 
pleted. Satellites  are  a 
natural  for  packets.  The 
time-sharing  aspect  makes 
the  satellites  available  to 
more  people,  and  the  com- 
munications are  more  reli- 
able The  list  is  almost 
endless,  and  that's  what 
makes  packet  so  good. 

If  you've  read  this  far, 
you  probably  want  to  know 
exactly  how  packet  radio 
works.  First  of  all,  you  will 
need  a  microprocessor- 
controlled  terminal,  which 
could  be  a  TV  typewriter 
or  Teletype  machine  for 
hard  copy.  We'll  look  at  a 
packet  Teletype  system  to 
see  how  it  works.  You  type 
out  your  message  and  the 
address  of  the  receiving 
station.  The  terminal  will 
fill  in  your  call  and  address 
as  well  as  do  the  error- 
detection  calculations. 
When  this  is  complete,  it 
will  be  sent  automatically. 
At  the  other  end,  a  terminal 
will  receive  the  packet  and 
took  at  the  address.  If  the 
packet  is  addressed  to 
someone  else,  the  terminal 
will  dump  it.  Otherwise,  it 
will  check  for  transmission 
errors  and,  if  the  message  is 
intact,  the  terminal  will 
print  it  out  or  display  it  on 
the  screen.  It  wilt  also  send 
an  acknowledgement  back 
to  you.  If  it  didn't  arrive  in- 
tact, it  will  send  a  negative 
acknowledgement.  Your 
terminal,  on  seeing  a  nega- 
tive acknowledgement,  or 
"NAK/'  will  retransmit  the 
packet  again,  and  will  do 
so  until  it  gets  through  or  it 
is  instructed  to  give  up. 

What  if  two  terminals 
send  at  once?  The  packets 
collide  and  are  wiped  out. 
In  this  case,  your  terminal 
won't    get    the    acknowl- 


edgement it  is  expecting, 
so  it  sends  the  packet 
again,  and  does  so  until  it 
gets  the  acknowledgement 
it  wants  or  is  told  to  stop. 
To  prevent  two  terminals 
from  sending  packet  after 
packet  at  the  same  time, 
each  terminal  is  instructed 
by  its  microprocessor  to 
wait  a  random  length  of 
time  before  sending  the 
packet  again.  The  delay  in 
our  case  would  be  from  1 
to  4  seconds.  Since  the 
delay  is  random,  and  all 
the  terminals  have  this 
routine  built  in,  the 
chances  of  a  second  or 
third  collision  are  very 
small. 

The  rules  that  the  ter- 
minals follow  are  called 
the  protocol.  This  term  will 
be  familiar  to  the  com- 
puter people.  The  protocol 
makes  every  user  feel  as  if 
he  is  the  only  one  on  the 
channel.  You  don't  know 
that  it  is  being  shared. 
There  is  no  QRM  and  no 
hassles.  The  protocol, 
which  is  written  into  the 
program  of  the  micro- 
processor controlling  your 
terminal,  can  be  as  simple 
or  as  complicated  as  you 
wish.  The  fancy  ones  make 
the  system  even  more  effi- 
cient and  maximize  the 
capacity  of  the  channel, 
but  involve  more  memory 
and  software.  The  key  is  to 
make  sure  that  all  users  of 
the  local  net  play  by  the 
same  rules. 

The  hardware  you'll 
need  is  not  fancy,  A  micro- 
processor, a  keyboard  in- 
put/output device,  a  radio, 
and  a  modem  are  all  that  is 
required.  Our  system  runs 
on  220-MHz  FM  and  uses 
the  Western  or  Sangamo 
Model  201  modem,  running 
at  2000  baud.  We  used  this 
one  because  it  was 
available  surplus  and  was 
cheap.  We  run  220  because 
that's  the  only  band  in 
Canada  we  are  allowed  to 
use  for  packet  right  now. 
The  radio  feeds  the  modem 
which  feeds  the  terminal. 
The  modem  outputs  phase- 


shift  keying  using  an 
1800-Hertz  tone  so  it  can 
go  right  in  the  microphone 
jack.  The  output  can  come 
from  the  speaker  line  or,  if 
you're  fussy,  right  from 
the  discriminator  to  the 
modem.  The  modem  is 
RS-232  standard,  so  hook- 
ing it  up  to  the  computer  is 
no  problem.  See  Fig.  1. 

We  have  only  touched 
the  surface  of  packet  radio 
and  its  applications. 
Before  you  go  any  further, 
however,  you  will  have  to 
either  move  to  Canada  or 
convince  the  FCC  that 
American  amateurs  should 
be  allowed  to  use  packet 
radio  as  well.  As  far  as  I 
know,  Canada  is  the  only 
country  which  is  permit- 
ting amateurs  to  experi- 
ment With  packet.  I  doubt 
that  it  will  stay  this  way  for 
very  long.  The  prognosis  is 
for  amateurs  to  develop 
the  first  really  large  packet 
network  on  VHF  and  UHF 
which  will  be  copied  by 
commercial  operations 
shortly  afterward.  Our 
satellites  will  be  the  prov- 
ing ground  for  more  packet 
techniques,  and  I  bet  com- 
mercial  stations  will  be 
looking  over  our  shoulders. 
Again,  amateurs  are  get- 
ting into  the  act  first.  Who 
else  could  supply  millions 
of  free  man-hours  of 
research  and  development 
to  the  world?  Right  now 
there  are  a  few  centers  do- 
ing research  on  packet 
radio,  Stanford  Research 
Institute  is  one,  for  in* 
stance,  and  while  they  may 
be  better  qualified  than  we 
are,  we  sure  outnumber 
them! 

Here,  in  Montreal,  the 
few  of  us  who  have  formed 
AMPAC  will  be  pushing  the 
technique  for  all  it's  worth. 
We  are  talking  to  AMSAT 
to  get  permission  to  use 
their  satellites  as  well  as 
negotiating  with  our 
government  to  get  more 
packet  privileges.  We 
would  be  happy  to  talk  to 
anybody  who  is  interested 
in  packet  radio. 


193 


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KENWOOD 
TR-7600  .  . 

The  radio 

that 
reinenribers 


The  all  new  Kenwood  TR-7600  is  packed  with  all  the  features 
you  could  want  in  a  2-meter  FM  rig.  Combining  it  with  the 
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(144.000-147-995  mhz),  800  channels,  dual  concentric  knobs 
for  fast  frequency  change,  ID  watts  RF  output  or  1  watt  low 
power,  memory  channel  with  simplex  or  repeater  offset  (600 
khz/1  mhz),  and  large,  bright  orange  LED  display.  Adding  the 
RM-76  Microprocessor  Control  Unit  provides  more  operating 
features  than  are  found  in  any  other  rig!  With  the  RM-76  you 
can:  Select  any  2-meter  frequency,  store  frequencies;  auto- 
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mhz).  and  set  upper  and  lower  scan  frequency  limits.  Rm-76 
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Price  to  be  announced. 


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The  "Memorizer" 
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repeater  operation  dignaiLEDand 
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This  uHimate  transceiver  has 
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Remotable  2-meter 
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can  detach  and  remotely  mount  the 
main  PLL  control  head,  with  micro- 
processor, can  store  3  freqs  .  and 
has  digital  LEDs 

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Requires  117  VAC  power  source. 

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HF  wattmeter 

Has  a  frequency  of  1  8-54  MHz,  a 
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to  3  ft.  away.  Connectors  SO-239. 
Line  imp.  50  ohms  reststance, 

89,00  Can  for  yours  today 


BIRD  MODEL  43 
Thruline^ 
watt  meter 

50     ohms     nominal     impedance 
VSWR  with  UHF  connectors  1  05 
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Low  insertion  loss  •  Frequency 
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x: 


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-1 


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plug-in  elements  ^^ 
for  the  Modei  43 

frequency  Bands  in  MHz 


Power 

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Ringp 

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50          5E 

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41 4  A 

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magnetic  mic  element  designed  tor 
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MC-30S  same  as  MC-35S  birl  500 
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10-40  antenna 

Features:  •  Taper  swaged 
seamless  dlyminum  con- 
struction •  Omnidirec- 
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Dale  Hikman  WB6NTR 
I J 32  Roseia  Drive 
Topanga  CA  90290 


This  Voltage  Standard  Is  Precise! 


and  makes  calibration  a  snap 


DO  yoy  sometimes  wish 
you  had  a  stable 
voltage  source  for  call- 
brating  your  DVM  or  the 
vertical  amplifier  of  your 
dc  scope,  a  source  that 
would  remain  rock  stable 


for  months  or  years?  Such 
an  instrument  is  usually  ex- 
pensive to  build  or  buy 
because  it  uses  exotic  com- 
ponents such  as  standard 
cells  and  perhaps  -a;  com- 
plex voltage  divider  to  pro- 


vide various  output  poten- 
tials. The  voltage  standard 
described  here  may  suit 
your  need  perfectly,  as  it 
provides  an  exceptipnaliy 
stable  output  voltage  using 
ordinary  off-the-shelf 
parts,  and  an  unconven- 
tional "circular"  voltage 
divider,  using  the  minimum 
possible  number  of  preci- 
sion resistors,  provides  con- 
venient  switch-selected 
output  voltages. 

The  unit  is  powered  by 
two  9"Volt  batteries,  and 
the  output  voltage  is  0-10 
volts  in  10  millivolt  steps, 
although  finer  voltage  divi- 
sions may  be  obtained  by 
adding  stages  to  the  volt- 
age divider,  A  microam- 
meter  is  connected  in 
series  with  the  output  so 
that  the  instrument  may  be 
used  to  directly  measure 
dc  voltage. 

Output  stability  is  about 
±0.04%  over  a  battery- 
voltage  range  of  6-9  volts. 
This  tolerance  can  be  re- 
duced virtually  to  zero  if 
you  elect  to  use  a  power 
source  better  regulated 
than  batteries. 

Thermal    stability,    over 

the  range  of  temperatures 
II  .        I    ■ 


less  perfect,  depending  on 
your  choice  of  parts.  Ad- 
mittedly, the  unit  must  be 
calibrated  against  an  accu- 
rate voltage  standard  or 
DVM  but,  once  set,  it  will 
remain  stable  more  or  less 
indefinitely,  depending 
again  on  your  choice  of 
parts.  Accuracy  of  the 
switch-selected  output 
voltages  depends  on  the 
tolerance  of  the  resistors 
you  decide  to  use  in  the 
voltage  divider.  We  have 
specified  0.1  %  resistors,  so 
we  get  0,1%  accuracy.  If 
you  use  0.01%  resistors, 
you  will  get  0.01%  accu- 
racy, but  they  will  cost  a 
lot  more.  Output  resis- 
tance of  the  instrument  is 
several  thousand  Ohms, 
but  we  will  discuss  means 
to  circumvent  the  effect  of 
loading  on  output  voltage. 

How  It  Works 

Fig.  1  is  a  simplified 
diagram  of  the  voltage 
standard,  showing  how  the 
use  of  a  ''circular"  voltage 
divider  minimizes  the  num- 
ber of  resistors  needed  to 
obtain  1001  different  out- 
put voltages.  This  article, 
as  far  as  we  know,  is  the 
first  published  application 


tional  voltage  divider,  the 
input  voltage  is  applied 
across  the  entire  network, 
and  output  is  selected 
from  the  constituent  resis- 
tors—but a  disproportion^ 
ally  large  number  of 
resistors  or  a  complex 
switching  schenae  is 
needed  to  get  a  large 
number  of  output  voltages. 
In  the  circular  voltage 
divider,  the  output  vo[tage 
is  taken  from  a  fixed  point, 
and  this  potential  is 
selected  by  changing  the 
location  to  which  the  input 
voltage  is  applied.  This 
scheme  simplifies  the  re- 
quisite switching  and 
minimizes  the  number  of 
resistors  needed.  In  Fig.  1, 
the  digit  beside  each 
resistor  corresponds  to  the 
voltage  obtained  when 
that  resistor  is  connected. 
Output  in  this  example 
would  be  6.43  volts. 

The  general  rule  apply- 
ing  to  resistor  values  in  the 
circular  divider  is  this:  Ten 
resistors  are  used  in  each 
ring  except  the  last,  which 
has  eleven.  The  resistors  in 
each  ring  are  1.1  times  the 
value  of  the  ones  in  the 
preceding  ring.  Thus,  if  you 
wanted  an  additional  stage 
to  get  steps  of  1  millivolt, 
you  would  substitute,  for 
the  terminating  resistor  Rj, 
another  ring,  containing  11 
resistors  of  1330  Ohms 
each.  How  did  we  know 
what  value  to  start  with  in 
the  first  ring?  Well,  if  too 
smalL  the  selected  resistor 
will  unduly  load  the  power 
supply.  But  making  it,  and 
all  the  other  resistors, 
larger  will  proportionally 
increase  the  output  resis- 
tance of  the  divider. 

If  you  want  to  build  the 
simplest  possible  divider, 
you  can  omit  the  selector 
switches  and  use  alligator 
clips  where  we  have  shown 
arrows.  To  use  the  instru- 
ment as  a  voltmeter,  con- 
nect the  voltage  to  be  mea- 
sured at  ''unknown  E/'  and 
set  the  clips  to  obtain  a 
null  on  the  meter.  The  un- 
known voltage  then  corre- 
sponds to  the  digits  beside 


the  selected  resistors. 

Fig.  2  is  a  schematic  of 
the  instrument,  except  for 
the  divider.  The  stable 
voltage  source  consists  of 
field  effect  transistors 
(FETs)  Q1  and  Q2,  and 
resistor  R1.  The  FETs  are 
connected  in  series,  form- 
ing  a  very  high  impedance 
current  source  which 
develops  the  reference 
voltage  across  R1  This 
means  of  obtaining  a 
stable  potential  has  not 
been  widely  exploited  and, 
indeed,  it  is  little  known 
even  among  FET  manufac- 
turers. The  reference  volt- 
age, Er,  depends  on  FET 
Q2,  ordinarily  turning  out 
to  be  somewhere  between 
1  volt  and  3.5  volts.  You 
don't  have  much  control 
over  this  parameter  unless 
you  individually  select  the 
2N3819  But  Er  is  remark- 
ably stable  with  changes  in 
battery  voltage  and  can  be 
made  almost  completely 
independent  of  tempera* 
ture  by  the  selection  of  R1, 
as  described  later. 

To  get  10  volts  for  the 
divider,  Er  is  amplified  by 
op  amp  IC1,  whose  gain  is 
set  by  the  selection  of  feed- 
back resistor  R3  and  the 
adjustment  of  CAL  trimmer 
R4.  The  S5556/MC1456  op 
amp  was  chosen  for  its  low 
bias  current  (about  30 
nanoamperes),  its  excellent 
temperature  stability,  and 
its  reasonable  price.  To  fur- 
ther enhance  temperature 
stability,  emitter-follower 
Q3  obviates  any  loading  on 
IC1  and  thereby  keeps  the 
op  amp  cool.  Capacitor  CI 
suppresses  any  tendency 
to  oscillate. 

The  divider  uses  three 
two-pole,  ID-position  selec- 
tor switches  to  perform  the 
function  of  the  alligator 
clips  suggested  for  Fig.  1, 
selecting  1000  different 
output  voltages  (0-9.99 
volts). 

Referring  again  to  Fig.  2, 
setting  switch  52  to  S EL  ap- 
plies the  selected  voltage 
to  the  output  circuit.  The 
1001th  voltage,  10  volts,  is 
obtained  in  the  10  V  posi- 


lOV 
REGULATE! 


R'lK  fACH  UI09 


ft>l.{K  EACH  t«  10) 


nazm  EACH  tilt » 


NUU.  mWCAWK 


Fig.  T.  Simplified  schematic  of  voltage  standard.  In  the 
"circular"  voltage  divider,  the  resistors  in  each  ring  are  1.1 
times  the  value  of  the  ones  in  the  preceding  ring.  A 
microammeter,  used  as  a  null  indicator,  provides  a  means 
for  directly  measuring  dc  voltage. 


tion.  The  potential  se- 
lected by  52  is  applied  to 
output  jack  j1  through 
microammeter  Ml.  The 
time  constant  R5-C2  and 
germanium  diodes  CR1 
and  CR2  protect  the  meter 
movement  from  slamming 
when  Jl  is  connected  to  a 
voltage  much  different 
from  the  one  selected. 
Resistor  R6,  in  turn,  pro- 
tects the  diodes  from  burn- 
out when  the  selected 
voltage  happens  to  be  0 
volts.  In  this  case  the 
divider  output  is  at  com- 
mon and,  without  R6.  any 
voltage  on  Jl  would  be  ap- 
plied directly  across  one  of 
the  diodes. 

Output  resistance  of  the 
divider  is  about  1000 
Ohms,  The  output  resis- 
tance   of    the    unit    is, 


therefore,  this  value  in 
series  with  R5,  R6,  and  the 
microammeter,  for  a  grand 
total  of  2000  to  5000 
Ohms,  depending  on  the 
meter  resistance.  There- 
fore, the  instrument  cannot 
be  loaded  without  loss  of 
accuracy.  Even  a  1 -meg- 
ohm load  could  drop  the 
output  voltage  as  much  as 
0.5%.  We  will  deal  with 
this  problem  under 
"Operation/'  On  the  other 
hand,  if  you  can  tolerate  a 
higher  output  resistance, 
you  would  be  well  advised 
to  make  all  the  resistors  in 
the  divider  much  larger  in 
value.  They  should  all  be 
increased  by  the  same  fac- 
tor, say  by  10  or  even  100 
times.  This  would  make  the 
current  in  the  first  divider 
ring  proportionally  lower, 


R4 


DIVtOCR 


10V 


!   jmt^t 


Jl 

OHOV 

OUtPklT 


MARY 
fOiJTPUT 


G) 


Fig.  2.  Schematic  of  precision  voltage  source  and  output 
circuit  of  instrument.  Inexpensive  2N3819  FETs  provide  an 
extremely  stable  reference  voltage,  amplified  to  10  V  by 
IC1  and  Q3.  Output  voltage  is  applied  to  11.  Microam- 
meter nail  indicator  is  protected  from  siamming  by  RC  cir- 
cuit and  diodes. 


201 


tnterior  view  of  instrument  AH  parts  are  mounted  on  back 
of  the  front  panei  The  divider  resistors  are  located  on  a 

perfboard  mounted  on  the  meter  terminals.  The  precision 
voltage  source  subassembly  is  built  on  another  perfboard 
mounted  to  the  first 


alleviating  problems  of 
stray  voltage  drops  and 
greatly  increasing  battery 
life.  However,  it  would  also 
reduce  meter  deflection, 
so    you    might    have    to 


employ   a   more   sensitive 
movement. 

If  you  wish  to  bypass  the 
various  resistances  of  the 
output  circuit,  you  can  add 
the  auxiliary  output  jack 


0 


0£3T  v*lUE  roH  nr 


I5K 


Fig.  3.  Graph  of  R1  vs.  £/?  when  /?7  is  4700  Ohms  approx- 
imates optimum  value  for  new  R1.  Exact  value  for  best 
temperature  stability  can  be  determined  by  heat  test  (See 
text  "Adjustment") 


shown  in  dashed  lines.  This 
addition  also  provides  ac- 
cess, when  S2  is  in  the  10  V 
position,  directly  to  the 
10-vott  source,  whose 
resistance  is  practically 
zero  4nd  which  can,  there- 
fore, be  loaded  heavily 
with  virtually  no  loss  of 
voltage* 

Choice  of  Paris 

Temperature  stability 
depends  on  your  choice  of 
RVR4.  For  best  results, 
precision  resistors  should 
be  used  for  R1-R3,  not 
because  these  resistances 
are  critical,  but  because 
precision  types  are  less  af- 
fected by  time  and  temper- 
ature than  composition. 
Film  or  wirewound  units 
are  a  good  choice. 
However,  the  values  of  R1 
and  R3  will  be  selected  as 
described  under  "Adjust- 
ment/' the  former  for  best 
temperature  indepen- 
dence and  the  latter  to  set 
the  output  voltage.  For  this 
selection  process,  you  can 
use  ordinary  composition 
resistors,  and  later  replace 
them  with  the  precision 
variety.  For  best  stability 
and  ease  of  adjustment,  R4 
should  be  a  multi-turn  trim- 
mer, either  wirewound  or 
cermet.  A  shaft  lock  is 
desirable.  Precision  re- 
sistors must  be  used  in  the 
divider  and,  as  we  have 
indicated  earlier,  a  closer 
tolerance  than  we  have 
specified  will  provide  more 
accurate  output  voltages. 
Any  general  purpose,  sili- 
con NPN  transistor  may  be 
substituted  for  the  2N697 
specified  at  Q3. 

If  you  have  a  mathe- 
matical bent  and  wish  to 
interpolate  the  meter 
reading  to  estimate  poten- 
tials falling  between  the 
positions  of  "hundredths" 
switch  S30,  you  may  wish 
to  use  a  more  sensitive 
meter  (say,  10-0-10  micro- 
amperes). In  this  case, 
CR1  and  CR2  will  intro- 
duce a  troublesome  non- 
linearity,  so  you  may 
wish  to  use  silicon  diodes 
or  back-to-back  zeners  for 


a  higher  threshold  voltage. 
If  you  want  the  meter  to 
respond  faster,  you  can  use 
a  smaller  value  for  C2. 
Either  change,  though,  will 
cause  the  meter  to  slam 
harder. 

Any  hookup  wire  used  in 
the  divider  section  of  the 
instrument  must  be  no 
smaller  than  No.  22. 
Smaller  wire  would  devel- 
op voltage  drops  that 
degrade  accuracy.  If  you 
have  decided  to  add  a 
fourth  or  fifth  stage  to  the 
divider,  you  should  care- 
fully consider  the  effect  of 
contact  resistance  in  the 
voltage  selector  switches. 
It  might  be  necessary  to 
procure  special  switches 
made  for  this  sort  of  ap* 
plication. 

Construction 

The    voltage   standard 

can  be  built  in  any  conve- 
nient enclosure.  As  shown 
in  the  photos,  all  parts  in 
the  author's  prototype,  in- 
cluding the  batteries,  were 
mounted  on  the  backside 
of  the  front  panel  of  an  in- 
strument  housing,  The 
divider  resistors  are  lo- 
cated on  a  perfboard 
mounted  to  the  meter  ter- 
minals. You  can,  instead, 
mount  the  resistors  direct- 
ly on  the  switch  terminals, 
but  this  will  much  com* 
plicate  matters  if  you  have 
to  correct  wiring  errors  or 
later  decide  to  change  the 
divider  resistors  for  ones 
having  different  values  or 
tolerances.  The  precision 
voltage  source  is  con- 
structed on  a  smaller  perf- 
board mounted  to  the  first 
by  spacers. 

Do  not  use  the  chassis  as 
the  common  conductor.  In- 
stead, use  wire  leads  be- 
tween components.  The 
common  conductor  may 
then  be  connected  to  the 
chassis,  but  at  one  point 
only.  If  the  connector  you 
plan  to  use  at  Jl  is  some- 
what difficult  to  insulate, 
as  many  jacks  are,  you  may 
make  the  chassis  connec- 
tion at  this  point,  as  shown 
by  the  dashed  symbol  in 


202 


Fig.  2,  This  connection, 
however,  creates  an 
obscure  but  potent  hazard. 
Due  to  manufacturing 
defects,  an  occasional 
9-volt  battery  has  an  inter- 
nal short  circurt  between 
one  terminal  and  the  case. 
!f  the  battery  case  is 
touching  the  chassis  and 
the  common  conductor  is 
also  connected  to  the 
chassis,  the  battery  will  be 
shorted  and  may  explode! 
Therefore,  as  in  any  equip* 
ment  using  9-volt  batteries 
where  the  case  is  ground- 
ed, it  is  smart  to  insulate 
the  battery  holders  from 
the  case.  Solder  carefully. 
Rosin  joints  introduce 
stray  voltage  drops. 

As  we  mentioned  earlier, 
the  values  of  resistors  Rl 
and  R3  will  be  individually 
selected.  For  now,  how* 
ever,  temporarily  install 
4700  Ohms  at  Rl  and 
18,000  Ohms  at  R3. 

Adjustment 

The  adjustment  pro- 
cedure has  two  main  parts. 
First,  Rl  must  be  selected 
for    best    temperature 

stability,  and  then  R3  must 
be  selected  to  yield  10 
volts  from  the  dc  amplifier. 
To  select  Rl,  proceed  as 
follows: 

l.Set  SI  to  ON. 

2.  Measure  voltage  Er 
across  4700-Ohm  resistor 
Rl. 

3.  Find  the  best  value  for 
the  new  Rl  from  Fig.  3, 
and  replace  Rl  with  this 
value, 

4.  If  you  are  using  a  DVM 
of  at  least  4  Vi  digits,  you 
can  now  verify  temper- 
ature stability  by 
touching  the  tip  of  a  hot 
soldering  iron  to  Q2  for 
about  3  seconds  Refer- 
ence voltage  Ef^  should 
not  vary  more  than  a  few 
millivolts,  [f  it  does,  cor- 
rect the  value  of  Rl  as 
needed. 

To  select  R3,  you  need 
only  a  reasonably  accurate 
voltmeter  such  as  a  typical 
VOM.  Then,  to  trim  R4  to 
exactly  10  volts,  you  will 


need    either    an    accurate 

DVM  [preferably  4 V2  digits 
or  more),  or  a  precision 
voltage  source  such  as  a 
standard  battery,  having  a 
known  terminal  potential 
up  to  10  volts.  If  you  don't 
need  perfect  calibration, 
however,  instead  of  a  stan* 
dard  battery  you  can  use  a 
brand  new  Mallory  Dura- 
cell  Type  MN-1604,  which 
has  an  open-circuit  poten- 
tial close  to  9.32  volts.  Do 
not  use  as  a  standard 
either  of  the  batteries 
powering  the  instrument 
because  its  load  drops  the 
voltage  too  much.  To 
select  R3,  proceed  as 
follows: 

1 .  Set  CAL  trimmer  R4'to  its 
mid-position, 

2.  Set  S2  tolO  V, 

3.  Connect  the  voltmeter 
between  common  and 
the  arm  of  S2,  or  to  the 
auxiliary  output  jack  if 
you  have  one. 

4.  Select  R3  to  get  a 
reading  as  close  to  10 
volts  as  possible. 

5-  If  using  a  DVM,  adjust 
R4  to  get  10.000  volts. 
This  step  ends  your  ad- 
justment  procedure. 
Otherwise,  proceed  to 
step  6. 

6.  Set  S2  to  SEL. 

7.  Set  the  selector  switches 
to  correspond  to  the 
voltage  of  the  standard 
battery, 

8.  Connect  the  standard 
battery  to  |1,  plus  to  the 
meter  side,  minus  to 
common. 

9.  Adjust  R4  to  zero  the 
meter. 

Operation 

The  voltage  standard 
has  two  main  uses,  as  a 
0-10- volt  dc  voltmeter  or  as 
a  precision  voltage  source. 
To  use  the  instrument  as  a 
dc  voltmeter,  proceed  as 
follows: 

1.  Set  SI  to  ON. 
Z  Set  S2  to  SEL. 
3.  Set  voltage  selector 
switches  S10,  S20,  and 
S30  to  approximate  the 
voltage  you  wish  to 
measure.  If  you  can't 
estimate   this   unknown 


;        3:i3V 


fig,  4.  Two  methods  to  avert  the  effect  of  loading  on  out- 
put voltage. 


voltage,  set  the  switches 
to  5.55  volts. 

4,  Connect  the  unknown 
voltage  to  |1,  plus  to  the 
meter  side  and  minus  to 
common. 

5.  Set  voltage  selector 
switches  S10,  S20,  and 
S30  to  zero  the  meter  as 
nearly  as  possible.  The 
switch  settings  now  cor* 
respond  to  the  unknown 
potential.  (If  the  un- 
known turns  out  to  be 


exactly  10  volts,  the 
meter  will  of  course 
zero  with  S2  set  at  1 0  V J 
If  the  meter  needle  is 
not  exactly  at  zero,  then 
the  unknown  is  a  few 
millivolts  different  from 
the  setting  of  "Hun- 
dredths" switch  S30. 
You  might  try  inter- 
polating to  estimate  the 
difference,  but  if  you 
have  used  0.1% 
resistors  in  the  divider. 


Parts  List 

{for  divider  of  Fig,  1) 
R10-R19  1,000'Ohm.  0.1%,  y*-Watt  precision  resistor 

R20'R29  1100-Ohm,  0.1%,  y4-Watt  precision  resistor 

R30'R40  laiD-Ohm,  0J%,  %-Watt  precisron  resistor 

S10,  S20,  & 
S30  2-pole.  imposition  rotary  swftch 

Note:  0.1  %  resistors  described  above  are  available  at  $1  €ach  from 
Gal-State  Electronics,  5222  Venice  8L,  Los  Angeles  CA  90019.  Add 

$1,50  for  shipping  (UPS).  California  residents  please  add  6%  sales 
lax. 


B1,  B2 

CI 

02 

CR1,CR2 

IC1 

J1 

Ml 

Q1,Q2 
Q3 
Rl 


R2 
R3 


R4 
R5 
R6 
SI 
82 
Misc. 


Parts  List 

(for  electron tcs  of  Fig.  2) 
9-volt  battery 
0.01  uF  capacitor 

2000  uF,  3-vQlt  electrolytic  capacitor 
IN  100  germaniunrt  diode 
S5556/MC1456  op  amp  (preferably  by  Signetics) 
phono  receptacle  or  other  suitable  2-conductor 
jack 

50-0-50  dc  microam meter 

2N3S19  field  effect  transistor  (Texas  Instruments) 
2N697  transistor 

1%,  V4-Watt  precision  resistor;  value  selected.  See 
text,  "Choice  of  parts/'  Temporarily  use  4700-Ohm 
composition-type. 

10,000  Ohm,  1%,  y^-Watt  precision  resistor 
1%,  V4-Watt  precfslon  resistor^  value  selected.  See 
text.  '^Choice  of  parts."  Temporarily  use  18,000- 
Ohm  composition-type. 
5N  panei-mounting  trimmer  potentiometer 
100-Obm,  10%,  V4 -Watt  resistor 
330'Ohm,  10%,V4*W3tt  resistor 
SPST  toggle  switch 
SPDT  toggle  switch 

22-gauge  hookup  wire  for  divider,  perfboard,  push- 
in  terminals,  IC  socket,  battery  clips,  battery 
holders,  cabinet,  etc.  To  select  Rl  and  R3,  a  suppEy 
of  5%  composition  resistors,  or  a  resistor- 
substrtution  ("decade")  box  in  the  range  of  1000 
Ohms  to  100,000  Ohms  Is  required.  See  separate 
parts  list  for  divider. 


203 


remember    that    your 
reading  will  only  be  ac- 
curate  within    0.1    per- 
cent  of    the    indicated 
voltage  anyhow. 
As  a  voltage  source,  a 
typical    use  of  the  instru- 
ment is  in  the  calibration  of 
a  voltmeter-  It  is  especially 
valuable,  for  example,  to 
check    the    linearity    of    a 
DVM,   However,  the  volt- 
age   source    application 
may  involve  loading  com- 
plications.   The    input 
resistance    of    a    typical 


DVM  is  100  or  1000  meg- 
ohms, so  it  should  give  you 
no  such  problem.  Given  a 
load  of  lower  resistance, 
though,  say  a  20,000-Ohms- 
per^volt  VOM,  you  must 
either  mathematically 
allow  for  the  load  or  avert 
its  effect  entirely.  In  the 
former  course,  you  are  on 
your  own,  but  with  the  lat- 
ter, we  can  offer  a  couple 
of  methods:  As  shown  in 
Fig.  4,  you  can  either 
decouple  the  voltage  stan- 
dard output  through  an  op 


amp  voltage  follower,  or 
create  a  bridge  with  the  use 
of  a  pot. 

In  the  method  of  Fig. 
4(a),  an  op  amp  is  con- 
nected as  a  voltage 
follower  to  relieve  the  load 
on  the  voltage  standard 
output.  For  best  accuracy, 
you  should  choose  an  op 
amp  that  has  provisions  for 
nulling  its  offset  and  which 
is  rated  for  low  offset- 
current. 

The  method  of  Fig.  4(b)  is 
simpler    and     cheaper 


though  not  as  convenient. 
In  this  method,  the  voltage 
standard  is  one  leg  of  a 
bridge,  the  other  being  pro- 
vided by  a  potentiometer 
that  matches  the  voltage 
set  by  the  standard,  With 
this  scheme,  once  having 
set  the  voltage  selector 
switches  to  the  potential 
you  want,  simply  adjust 
the  pot  to  zero  the  meter. 
For  smoothest  adjustment, 
the  resistance  value  of  the 
pot  should  be  one  half  to 
one  tenth  Rl.  ■ 


frompagt  158 

ab(e  K-2  frequency-determining 
elements,  avaitabte  in  aff  El  A 
tone  frequencies  from  268.5  Hz 
to  2109.0  Hz. 

Power  requirements  are  6  to 
16  V  dc  unregulated  al  10  mA. 
Reverse  polarity  and  over- 
voltage  protection  are  buUt^n. 
AH  connections  to  the  board 
are  made  with  push-on  connec- 
tors, and  color^coded  wires  are 
furnished. 

The  SD-1  may  be  driven  by 
the  discriminator,  by  the  audio 
stages,  or  from  the  speaker  cir- 
cuit. Sv^fltched  outputs  Include 
momentary  high  current  clo- 
sure to  ground  for  horn  relay,  a 
latched  high  current  closure  for 
a  call  light,  and  a  latched  low 
current,  high  voltage  pull-away 
from  ground  to  unmute  the 
receiver. 

The  unit  is  completely  Im- 
mune to  rf  and  comes  complete 
with  universal  mounting  hard- 
ware, A  full  one  year  warranty 


applies  when  the  unit  is  re- 
turned to  the  factory  for  repair. 
For  further  information,  con- 
tact: Communications  Speciat- 
ists,  426  West  Taft  Avenue, 
Orange  CA  92667:  (714}-998- 
3027,  (800^854^0547.  Reader 
Service  number  06. 


YAESU'S  FT  225RD  2M 
TRANSCEIVER 

A  new  state-of-the-art  2 
meter  all-mode  transceiver,  the 
FT-225RD,  has  been  added  to 
Yaesu's  quality  line  of  amateur 
radio  equipment. 

The  new  transceiver  covers 
the  entire  4  MHz  and  provides 
for  USB,  LSB,  CW,  FM,  and  AM. 
Power  output  is  variable,  1-25 
Watts.  Squelch,  VOX,  PTT, 
semi-break-in  CW  with  side- 
tone,  and  tone  burst  are  stan- 
dard features  of  the  FT-225RD. 
A  superb  noise  blanker  permits 
mobile  SSB  operation,  and  a 
discriminator  center  meter 
allows  precise  zeroing  on  FM 


signals.  Repeater  splits  are  the 
standard  6O0  kHz;  however,  any 
split  up  to  1  MHz  is  possible 
with  optionat  crystals.  Provi* 
sion  has  been  made  for  up  to 
eleven  (11)  fixed  channels  us- 
ing optional  crystals. 

The  transceiver  utilizes  high 
quality  plug-in  circuit  boards 
throughout,  and  an  optional 
memory  unit  enabfes  the 
storage  and  recall  of  any  fre- 
quency Within  the  range  of  the 
unit.  This  aMows  Instant  pro- 
grammabte  QSY  to  a  favorite 
repeater  or  calling  frequency 
with  just  a  flick  of  the  switch. 
The  digital  frequency  is  ac< 
curate  to  0.1  kHz  (or  to  1  kHz 
with  the  FT-225R,  which  offers 
the  analog  dial  readout  only  at 
slightly  less  cost). 

A  built-in  power  supply  pro- 
vides taps  for  operation  on  100/ 
110/117/200/220  and  234  volts 
50/60  Hz.  Dc  operation  covers 
11.5  to  16  volts,  negative 
ground  at  6.5  Amps  on  trans- 
mit, 1.2  Amps  on  receive,  The 
transceiver  measures  280  (W)  x 
1 25  (H)  X  3T5  (D)  mm  and  weighs 
only  9.0  kg. 

An  attractive  four-color 
brochure  is  available  at  your 


nearby  authorized  Yaesu  dealer 
or  from  Yaesu  Biectromcs  Cor- 
po  fat  ion,  15954  Downey  Ave- 
nue, PO  Box  498,  Paramount 
CA  90723.  Reader  Service 
number  Y1, 

ECONOMY  HAND  TOOL 
CRIMPS  BELDEN  8231  CABLE 

AMP  Special  Industries* 
Coax  Economy  Stamped  Hand 
Tool  line  has  been  expanded  to 
include  Belden  6261  cable,  a 
popular  75-Ohm  video  cable 
used  by  television  studios, 
broadcasting  systems,  and  test 
equipment.  Designed  to  crimp 
UHF  and  BNC  connectors  on 
the  Befden  6281  cable,  this 
quality  SUPER  CHAMRTM  hand 
tool  is  lightweight  and 
economical.  Its  features  In- 
clude a  guide  on  the  tool  body 
for  strip  dimensions  in  all  coax 
series— standard,  economy, 
single,  or  dual  crimp.  The 
handles  are  cushioned  for 
greater  comfort. 

For  more  Information,  con- 
tact: Ah^P  Special  industries, 
Vailey  Forge  PA  19482,  Reader 
Service   number   A70.   SUPER 

Continued  on  page  253 


The  FT-225RD  2m  transcetver  from  Yaesu. 


AMP  Special  tnduBtnes'  new  SUPER  CHAMP  hand  tool 


204 


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y^  Header  Service  see  fxage  323. 


205 


The  22S  Goes  Digital 

—  add  7-segment  displays 


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F/g.  7.  IC-22S  frequency  display  schematic  diagram. 


IDO  MHi 
DISPLAY 


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Raymond  E.  Thompson  KH6IEL 
2040  Komo  Mai  Drive 
Peari  City  HI  96782 

Although  very  popular 
since  its  introduction 
by  Icom,  one  big  problem 
with  the  IC-22S  is  that  it  is 
so  darn  hard  not  to  add 
nnodiffcations.  Funny,  but 
with  a  crystal-controlled  2 
meter  transceiver,  the 
thought  of  adding  addi- 
tional channels  seldom 
enters  your  mind.  Six,  fif- 
teen, or  twenty-four  chan- 
nels or  whatever  was 
originally  supplied  seems 
adequate.  When  you  own 
an  IC-22S,  you  can  program 
any  frequency  you  like 
with  diodes.  Frequency 
selection  with  only  one 
knob  is  a  great  feature 
which  really  adds  a  lot  to 
operating  convenience. 
That's  where  the  problem 
comes  in.  The  23  channels 
that  you  can  select  don't 
seem  to  be  enough.  Some- 
thing keeps  you  trying  to 
think  of  different  methods 
of  getting  more  channels. 
Several  easy  ones  come  to 
mind  right  away:  adding  an 
eight-level  DIP  switch, 
using  toggle  switches  to 
add  15,  30,  or  45  kHz  to  the 
programmed  frequency,  or 
adding  a  second  matrix 
board  and  using  the 
previous  high/low  power 
switch  as  a  selector.  All  of 
these  have  one  common 
drawback:  You  have  to 
memorize  switch  settings 
or  use  charts,  tables,  etc., 
to  know  what  frequency 
you  are  operating  on.  Even 
the  mode  switch  can  cause 


206 


problems  if  you  forget  that 
some  of  your  programmed 
channels  are  simplex 
rather  than  repeaters. 
What  is  needed  is  a  direct 
frequency  readout. 

That  is  the  subject  of  this 
article.  A  direct  frequency 
display  for  the  IG22S,  It 
works  on  receive  or  trans- 
mit and  converts  whatever 
binary  code  you  have  at 
the  divider  input  in  the 
IC-22S  to  a  direct-reading 
frequency. 

Programming  the  diode 
matrix  board  for  a  par- 
ticular frequency  has  been 
covered  in  several  articles 
and  in  the  operating  man- 
ual, so  I  won't  go  into  any 
of  that.  The  circuit  for  the 
frequency  readout  can  be 
broken  down  into  two 
functions.  First,  we  must 
convert  the  eight-level 
binary  code  in  the  IC"22S 


The  clock  case  used  to  enclose  the  display  fits  very  nicety  on  top  of  the  IC-ZZS.  No  ques- 
tion as  to  what  frequency  channel  5  is  on  this  IC-22S. 


AODRtSS    SWITCHES 


fteAD^^HOQflfM    SWITCHES 


Fig,  Z  Manual  programmer  from  Signetics  for  82S129  PROM. 


207 


divider  into  the  appro- 
priate BCD  code  for  fre- 
quency, Second,  we  have 
to  convert  the  BCD  code  to 
a  visual  display  of  frequen- 
cy. ''Why  two  steps  and  not 
just  one?"  you  might  be 
asking.  It's  simpler  using 
two  steps.  We  have  eight 
inputs  to  convert  to 
twenty-two  outputs.  Two 
for  the  MHz:  (6  and  7)  and 
ten  for  both  the  100 
kHz  and  10  kHz  positions 
(1-10).  If  we  use  seven- 
segment  LEDs,  this  cuts  our 
requirements  down  to  fif- 
teen. Eight  inputs  must  be 
converted  to  fifteen  out- 
puts. No  such  device  is 
available. 

Instead  of  looking  at  all 


three  displays  together, 
and  by  looking  at  each  one 
separately,  we  come  up 
with  eight  inputs  and  seven 
outputs  for  the  10  and  100 
kHz  digits.  This  is  still  a 
pretty  expensive  thing  and 
beyond  using  simple  gate 
logic.  If  we  use  a  standard 
BCD-to-seven-segment  de- 
coder ahead  of  each  dis- 
play, we  have  cut  our  re- 
quirements to  eight  inputs 
with  four  outputs.  Now  we 
are  getting  somewhere! 
Any  256  x  4-bit  converter 
would  work,  one  for  each 
display  digit.  That's  it.  Tie 
three  256  x  4-bit  PROMs, 
with  their  inputs  in 
parallel,  to  standard 
decoders    to    drive    the 


display  digits! 

Looking  at  the  sche- 
matic diagram  [Fig.  1),  IC1 
and  IC2  are  simply  hex  buf^ 
f er  converters.  They  get  the 
CMOS  binary  divider  out- 
puts down  to  TIL  where  we 
can  use  them.  Since  only 
eight  are  needed,  there  are 
four  unused  buffers  which 
could  be  used  for  some 
other  purpose.  I  used  the 
82S129  PROM  for  two  rea- 
sons. A  256  X  4-bit  device 
was  required  and  the 
82S129  PROM  cost  was 
only  $2.50  from  S.D.  Sales. 
The  PROM  for  the  MHz 
position  (IC3)  has  to  be  pro- 
grammed to  produce  a  5, 6, 
7,  or  8  with  the  appropriate 
binary  input.  Likewise,  IC4 


must  be  programmed  to 
output  the  proper  BCD 
code  in  the  100  kHz  posi- 
tion of  the  frequency 
readout,  IC5  is  for  the  10 
kHz  numbers. 

Let's  look  at  146,520 
MHz  to  see  how  this  works 
out-  146.520  has  the  binary 
address  of  142.  This  is 
found  in  the  owner's  man- 
ual or  can  be  calculated  by 
several  means.  So,  we  need 
the  binary  address  code  of 
142  to  be  changed  to  a 
BCD  code  representing 
146520.  The  hundreds  and 
tens  of  MHz  (1  and  4)  will 
never  change,  so  they  can 
be  either  hardwired  in  the 
display  or  forgotten  about, 
IC3  (MHz)  is  programmed 


Program  chart.  145350-148.035 


Address 

ica 

iC4 

IC5 

13Q 

«4 

^i 

1« 

4 

4 

2 

1 

«  4  2  1 

a  4  2  t 

6  4  2  1 

064 

0 

0 

0 

0 

0 

0 

0 

0101 

0011 

0101 

065 

0 

0 

0 

0 

0 

0 

1 

0101 

0011 

0110 

066 

0 

0 

0 

0 

0 

1 

0 

0101 

0011 

1000 

067 

0 

0 

0 

0 

0 

1 

1 

0101 

0011 

1001 

068 

0 

0 

0 

0 

1 

0 

0 

0101 

0100 

0001 

069 

0 

0 

0 

0 

1 

0 

1 

0101 

0100 

0010 

070 

0 

0 

0 

0 

1 

1 

0 

0101 

0100 

0100 

071 

0 

0 

0 

Q 

1 

1 

1 

0101 

0100 

0101 

072 

0 

0 

0 

0 

0 

0 

0101 

0100 

0111 

073 

0 

0 

0 

0 

0 

1 

0101 

010O 

1000 

074 

0 

0 

0 

0 

1 

0 

0101 

0101 

0000 

075 

0 

0 

0 

0 

1 

1 

0101 

0101 

0001 

076 

0 

0 

0 

1 

0 

0 

0101 

0101 

0011 

077 

0 

0 

0 

1 

0 

1 

0101 

0101 

0100 

078 

0 

0 

0 

1 

1 

0 

0101 

0101 

0110 

079 

0 

0 

0 

1 

1 

1 

0101 

0101 

0111 

080 

0 

0 

0 

0 

0 

0 

0101 

0101 

1001 

081 

0 

0 

0 

0 

0 

1 

0101 

01  to 

0000 

082 

0 

0 

0 

0 

1 

0 

0101 

0110 

0010 

083 

0 

0 

0 

0 

1 

1 

0101 

0110 

0011 

084 

0 

0 

0 

1 

0 

0 

0101 

0110 

0101 

085 

0 

0 

0 

1 

0 

1 

0101 

0110 

0110 

086 

0 

0 

0 

1 

1 

0 

0101 

0110 

1000 

087 

0 

0 

0 

1 

1 

1 

0101 

0110 

1001 

088 

0 

0 

0 

0 

0 

0101 

0111 

0001 

089 

0 

0 

0 

0 

1 

0101 

0111 

0010 

090 

0 

0 

0 

1 

0 

0101 

0111 

0100 

091 

0 

0 

0 

1 

1 

0101 

0111 

0101 

092 

0 

0 

1 

0 

0 

0101 

0111 

0111 

093 

0 

0 

1 

0 

1 

0101 

0111 

1000 

094 

0 

0 

1 

1 

0 

0101 

1000 

0000 

095 

0 

0 

1 

1 

1 

0101 

1000 

0000 

096 

0 

0 

0 

0 

0 

0 

0101 

1000 

0011 

097 

0 

0 

0 

0 

0 

1 

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1000 

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098 

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1000 

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099 

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1000 

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100 

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1 

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0 

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1000 

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101 

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103 

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105 

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107 

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113 

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114 

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115 

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116 

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117 

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118 

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119 

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121 

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123 

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124 

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130 

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136 

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138 

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143 

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145 

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203 


for  a  BCD  6  (0110).  1C4 
(kHz)  at  address  142  is  pro- 
grammed for  an  output 
BCD  5  (0101).  Likewise  IC5 
(10  kHz)  at  address  142  is 
programmed  to  a  BCD  2 
(0010).  The  kHz  position 
does  not  require  a  PROM 
for  conversion  because 
anytime  DO  is  low,  we 
want  a  0,  and  when  it's 
hfgh,  we  want  a  5.  In  this 
case,  the  binary  number  is 
142  (10001110),  so  we  read 
a  0  DO  is  the  last  digit  of 
the  binary  or  the  least 
significant.  For  address 
142,  we'll  have  IC3  =  6, 
IC4  =  5,  IC5  =  2.  and  DO 
=  0,  As  another  example, 
take  a  look  at  146  010 
MHz.   The  binary   address 


for  this  frequency  is  108  or 
01101100.  Here  we'll  want 
IC3  =  0110,  IC4  =  0000, 
IC5  =  0001,  and  DO  =  0. 

The  second  function  is 
changing  the  BCD  outputs 
to  a  display  reading.  I  just 
happened  to  have  a  six- 
digit  display  that  I  had 
been  wanting  to  use,  so  I 
used  7445  BCD-to-decimal 
decoders.  LEDs  and  ap- 
propriate decoders  would 
work  nicely  and  would 
probably  be  the  logical 
choice  if  you  didn't  already 
have  some  other  type  of 
readout  display. 

Programming  the  PROMs 
was  my  first  experience 
with  PROMs.  Until  this 
time,  I  just  didn't  have  a 


need  to  get  into  this.  I  was 
a  little  leery  about  at- 
tempting it,  but  I  soon 
found  out  that  it  wasn't 
that  hard.  I  did  follow  the 
manufacturer's  circuit 
recommendations  and  the 
PROMs  were  programmed 
without  difficulty.  I  built 
the  required  programmer  cir- 
cuit into  my  Heathkit®  IC 
Tester,  since  the  IC  socket 
and  all  the  switches  were 
already  there.  I  had  to 
modify  my  IC  Tester  in 
order  to  do  this;  however,  t 
won't  go  into  any  details  of 
the  modification.  I  will  just 
include  the  circuit  recom* 
mendations  from  the  chip 
manufacturer.  I  will  have 
to  agree  with  others  that 


patience  and  care  are  the 
main  things  you  must  have 
when  you  are  manually 
programming  a  PROM.  The 
manufacturer  also  in- 
cluded waveforms  to  be 
used  with  automatic  pro- 
gramming. 

The  programmer  circuit 
[Fig.  2)  appears  at  first  to  be 
a  little  involved,  but  is 
really  pretty  straightfor- 
ward. The  complete  cycle 
takes  5  milliseconds  and  is 
controlled  by  one-shot  1, 
Its  resting  state  causes  the 
case  of  the  5-volt  regulator 
to  be  grounded  through  Vi 
of  the  75451,  which  puts 
Vcc  for  the  PROM  at  5 
volts.  With  the  address 
switches  set  to  the  desired 


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2m 


The  three  PROMs  m  the  lower  ieti  leave  plenty  of  room  for 
the  four  decoders  and  display  lamps.  This  clock  case 
would  be  almost  empty  if  LEDs  had  been  used. 


address,  flipping  any  one 
of  the  output  switches 
starts  the  5  ms  cycle.  The 
case  of  the  regulator  is 
ungrounded,  which  raises 
Vcc  up  to  8J5  votts  and 
starts  one-shot  2  for  a  2  ms 
delay.  Following  the  delay, 
one-shot  3  is  turned  on  for 
3  ms.  This  removes  the 
ground  from  the  regulator 
and  selected  output  pin, 
which  lets  this  go  to  17 
volts,  it  also  starts  delay 
one-shot  4  which  operates 
one-shot  5  after  1  ms  delay. 
One-shot  5  raises  the  chip 
enable  pin  for  1.5  ms.  The 
waveforms  are  indicated 
on  the  diagram  The  output 


switch  is  returned  to  the 
read  position  and  another 
output  to  be  programmed 
to  a  one  at  this  address  will 
run  the  cycle  again. 

I  started  my  program- 
ming with  IC3.  To  get 
started  and  check  my  pro^ 
cedures,  I  put  in  address  1 
(00000001)  With  ail  output 
switches  in  the  read  posi- 
tion, the  LEDs  remained 
off.  indicating  a  0000  in  the 
output.  I  toggled  the 
switch  for  output  1  [pin  12). 
The  circuit  ran  through  its 
operation  and  was  now 
reading  a  1 .  Leaving  the  ad- 
dress switches  at  00000001 , 
I  flipped  each  of  the  other 


ICI  and  IC2  are  shown  mounted  on  the  shield  using  a 
stand-off.  The  added  accessory  connector  on  the  left 
leaves  plenty  of  spare  connectors  for  other  goodies. 


output  switches  and.  sure 
enough,  they  now  read 
1111.  (With  this  circuit,  just 
toggling  the  desired  output 
switch  from  read  to  pro- 
gram and  back  again  is  all 
that  is  required  to  program 
a  1  into  the  output.  Noth- 
ing could  be  easier,)  I  had 
just  programmed  a  BCD  1 5 
into  address  1.  This  didn't 
matter  because  the  first  ad- 
dress that  I  was  going  to 
need  was  108.  So  with  108 
as  the  address  [01101100L 
all  I  had  to  do  was  program 
a  BCD  number  6  (0110).  I 
programmed  these  outputs 
(pins  11  and  10)  to  ones 
When  I  switched  to  anoth- 
er address,  my  outputs 
went  to  0000  Returning  to 
108,  I  had  my  BCD  6,  big  as 
life.  I  then  went  down 
through  the  remaining  ad- 
dresses, programming  the 
appropriate  BCD  6  or  7.  In 
fact,  I  decided  to  program 
the  appropriate  BCD  num- 
ber all  the  way  from  64 
through  243,  just  because 
my  IC-22S  would  operate 
in  this  range. 

IC4  and  tC5  were  not  as 
straightforward  because 
they  have  a  lot  of  changes 
in  their  outputs.  To  keep 
f^om  getting  confused,  I 
made  up  a  chart  which 
gave  me  the  outputs  for 
each  PROM.  Numbering 
from  64  through  243,  I  put 
down  the  eight-bit  binary 
address  and  then  the  ap* 
propriate  BCD  number  for 
each  PROM.  Before  chang- 
ing to  the  next  address,  I 
checked  the  chart  against 
my  LEDs  to  make  certain 
that  I  had  the  right  BCD 
number  programmed. 
Making  the  output  a  1  is 
easy,  but  once  you  toggle 
the  switch,  it's  a  1,  and  if 
you  toggle  the  wrong 
switch  at  that  address,  you 
are  in  trouble. 

One  suggestion  I  have  is 
to  mark  each  PROM  with 
some  kind  of  identification 
after  being  programmed. 
They  all  look  aHke  and  are 
much  easier  to  visually 
identify  than  to  look  up  the 
output  codes  in  your  pro- 
grammer    to    tell    the    dif- 


ference, once  they  are  pro- 
grammed. 1  marked  mine 
by  the  number  of  kHz. 

I  placed  the  PROMs,  de- 
coders, and  displays  all 
together  in  a  small  clock 
cabinet.  This  kept  my  inter- 
face cable  down  to  11 
wires,  I  used  perf board 
and  point-to-point  wiring. 
ICI  and  1C2  are  mounted 
close  to  the  divider  and 
add  circuit.  I  used  ribbon 
cable  from  the  converter 
outputs  to  the  accessory 
jack.  If  power  is  connected 
through  the  two  spare  pins 
of  the  power  cable,  the 
original  9-pin  socket  is  ade- 
quate. Removing  the  orig- 
inal 9'pin  socket  and 
replacing  it  with  a  24-pin 
connector  would  be  a  iot 
better.  Once  you  use  all  9 
pins  for  a  frequency  dis- 
play, you  will  certainly 
need  more  pins  to  add 
channels,  or  a  scanner,  or 
an  external  meter,  or  some- 
thing. I  couldn't  find  a 
24-pin  connector  locally, 
so  I  enlarged  the  opening 
and  put  in  a  36-pin 
Waldom  connector. 

When  soldering  connec- 
tions to  the  pins  of  the 
divider,  use  care.  The  in* 
puts    for    the    converters 

could  be  taken  from  the 
matrix  board  [DO  through 
D7)  rather  than  the  divider 
(DO  through  P7)  which 
would  be  easier  to  get  to.  If 
this  is  done,  in  order  to 
make  the  frequency  read 
correctly,  two  CD4008  full- 
adders  would  have  to  be 
placed  ahead  of  the 
PROMs  and  operated  with 
the  DP  line.  I  gained  access 
to  the  divider  inputs  (DO 
through  P7)  by  removing 
the  matrix  board,  removing 
the  3  mounting  screws  and 
one  threaded  stand-off, 
and  turning  the  board  up 
so  I  could  get  to  the  pins  of 
the  ICI  divider  The  wires 
were  soldered  onto  pins  1 
through  8  of  ICI  and  run 
toward  the  rear  of  the 
transceiver.  These  wires 
run  under  the  board  out  to 
the  perfboard  for  ICI  and 
IC2.  I  put  my  outputs  of  the 
converters  on  one  side  of 


210 


the  perfboard  and  the  in- 
puts on  the  other  side, 
which  helped  in  keep- 
ing the  installation  neat, 
My  display  lamps  and 
drivers  draw  a  little  over 
600  mA,  so  I  used  two 
separate  5-volt  regulators. 
I  mounted  these  on  a  metal 
plate  with  heat  sinks.  The 
plate  is  mounted  to  the 
back  of  the  IC-22S  with 
stand-offs.  The  logic 
doesn't  draw  much  current 
so,  depending  on  the  dis* 
play  requirements,  one 
regulator  might  do  the  job. 
The  display  can  be 
mounted  on  top  of  the 
IC-22S  or  any  easily 
readable  position. 

Since  the  binary  code 
present  at  the  divider  is 
always  present  and  con- 
verted to  a  frequency  read- 
out  on  the  display,  there 
are  no  adjustments  or 
alignments.  I  checked  each 
section  for  proper  opera- 
tion as  they  were  put  to- 
gether The  display  and 
drivers   were   checked    by 


substituting  a  BCD  number 
into  each  frequency  posi- 
tion. The  PROMs  of  course 
were  checked  during  pro- 
gramming and  the  con- 
verters were  checked  to 
make  certain  that  they 
faithfully  followed  the 
binary  number  in  the 
divider.  Once  connected 
together,  the  job  is  com* 
pleted. 

At  first,  I  tried  to  make 
use  of  all  that  room  around 
the  speaker.  So  I  made  a 
shield  with  a  copperclad 
board  over  the  main  board 
and  mounted  the  shield 
very  close  to  the  main 
board.  This  caused  prob- 
lems by  changing  the  tun- 
ing of  the  output  circuit. 
Moving  the  ICs  up  next  to 
the  divider  and  removing 
my  shield  board  solved  the 
problem.  I  mention  this 
because,  at  first  glance,  it 
appears  that  mounting  the 
hex  buffers  near  the  ac- 
cessory socket  is  a  good 
idea,  but  it  isn't.  I  used  flat 
ribbon  cable  and  kept  it  up 


and  away  from  the  rf  cir- 
cuits. 

Because  of  the  numer- 
ous variations  possible,  I'm 
sure  that  each  frequency 
display    addition    will    be 


done  a  little  differently. 
This  article  outlines  one 
way  that  it  can  be  done,  so 
hopefully  it  will  inspire  you 
to  put  one  together  for 
your  IC-22S.H 


Photos  by  Jan  Kaneshlro 


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211 


Lawrence  L  Cotariu  WA9MZS 
Skokie  fL  60076 


WARC  v9  Preview 


showdown  in  Geneva 


The  World  Administra- 
tive Radio  Conference 
(WARC)  will  reconvene  in 
Geneva,  Switzerland,  on 
September  24,  1979.  It  is 
scheduled  to  last  ten 
weeks  at  the  International 
Telecommunication  Union 
headquarters'  complex. 

The  last  WARC  was  held 
in  Geneva  during  1959. 
Delegates  from  over  100 
countries  attended  to 
discuss  and  revise  regula- 
tions that  govern  the  inter- 
national use  of  the  radio 
spectrum.  Regional  con- 
ferences have  been  held 
since  then  to  review  mat- 
ters such  as  the  handling  of 
third-party  traffic. 

To  understand  how 
amateur  radio  as  a  hobby 
fits  into  the  global  scheme 
of  things,  one  should  be 
aware  of  the  purpose  and 
workings  of  the  ITU.  Therr 
negotiations  will  lead  to  a 
treaty  that  will  have  an 
enormous  effect  on  how 
the  communication  ser- 
vices of  the  world  wif! 
function. 

History  of  the  ITU 

the  ITU  has  existed  for 
over  100  years  and  is  the 
oldest  of  agencies  that  are 
affiliated  with  the  United 
Nations.  It  first  operated  as 
a  separate  body  until  the 
UN  absorbed  it  in  an  agree- 
ment signed  in  1947  It  was 


organized  mainly  to  help 
regulate  the  use  of  the 
electric  telegraph,  which 
was  made  available  to 
the  public  during  the 
mid~1800s. 

Various  treaties  were 
negotiated  between  the  na- 
tions of  Europe.  The 
governments  had  to  face 
difficulties  that  would 
have  to  be  overcome. 
When  Prussia,  in  1848, 
decided  to  link  its  capital 
with  places  on  the  borders 
of  its  kingdom,  it  had  to 
conclude  at  least  15 
treaties  with  the  German 
states  to  obtain  the  rights 
of  passage  needed  for  the 
building  of  telegraph  lines. 

The  International  Tele- 
graph Convention  was 
signed  during  the  1865 
Paris  Conference  by  20 
countries.  These  nations 
made  up  the  International 
Telegraph  Union,  which 
was  the  original  name  of 
the  ITU. 

Then,  in  1895.  the  first 
successful  wireless  trans 
missions  signaled  the 
greatest  revolution  in  the 
history  of  telecommunica- 
tions: the  invention  of 
radio.  It  was  first  regarded 
as  a  radically  advanced 
form  of  telegraphy.  Radio 
spread  across  the  interna- 
tional scene  more  rapidly 
than  the  telegraph  had 

With  the  rapid  use  of 
radio  as  a  form  of  conn- 


munication,  it  became 
clear  that  international 
regulations  were  needed 
to  accommodate  it.  This 
became  apparent  in  1902 
when  Prince  Henry  of 
Prussia  was  returning 
across  the  Atlantic  from  a 
visit  to  the  United  States. 
He  attempted  to  send  a 
courtesy  message  to  Presi- 
dent Roosevelt.  It  was 
refused  by  the  operator  of 
a  U.S.  coastal  station 
because  the  radio  equip- 
ment on  the  ship  was  of  a 
different  type  and  na- 
tionality than  that  of  the 
shore  station.  As  a  result  of 
this  incident,  the  German 
government  called  for,  and 
convened,  the  1903  Berlin 
Radio  Conference, 

In  three  years,  another 

conference  was  held  where 
the  first  international  radio 
regulations  incorporated 
the  principle  that  ships  and 
coastal  radio  stations  must 
accept  messages  from 
each  other. 

The  first  World  War 
greatly  stimulated  the 
development  of  radio,  and 
in  the  early  1920s,  the  In- 
ternational Broadcasting 
Radio  Service  began.  A 
new  problem  became  how 
to  share  the  radio  frequen- 
cies to  avoid  the  inevitable 
interference  between  sta- 
tions Even  today,  the 
global  responsibility  for 
radio  frequencies  remains 


one  of  the  ITU's  heaviest 
and  most  vital  jobs. 

It  was  not  until  the  ITU 
conference  of  1927  that  a 
reference  to  the  Amateur 
Radio  Service  was  made: 
private  experimental  sta- 
tions. The  Washington, 
DC,  meeting  allocated 
bands  of  frequencies  to  all 
of  the  various  radio  ser- 
vices, including  maritime, 
broadcasting,  and  ham 
radio.  Hams  had  been 
operating  in  the  U.S. 
before  this  year  but  were 
now  officially  recognized 
by  the  world  community. 

During  the  second  World 
War,  broadcasting  brought 
the  fact  home  to  everyone 
that  radio  waves  respected 
no  geographical  boun- 
daries. It  was  apparent  that 
much  wider  world  agree- 
ments would  have  to  be 
drawn  up  for  radio. 

Radio  Conference  Pro* 
cedure 

The  upcoming  con- 
ference's purpose  is  to 
review  the  regulations  cur- 
rently in  effect  and  to 
devote  the  proceedings  to 
those  needing  revision.  By 
the  time  the  official 
delegations  assemble  in 
Switzerland,  governments 
would  have  already  firmed 
up  their  positions  with  the 
aid  of  private  organiza- 
tions and  citizen  groups. 
Their    views    will    have 


212 


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been    submitted    to   the 

Secretariat  of  the  ITU  and 
published  in  a  single  book 
of  proposals.  Copies  then 
would  have  been  cir- 
culated to  all  member  na- 
tions to  enable  each 
delegation  to  know  what 
everybody  else  is  thinking. 

In  the  VS.,  negotiation 
of  the  treaty  is  exclusively 
the  responsibility  of  our 
State  Department.  Various 
working  groups  have  been 
meeting  for  the  past  two 
years  hashing  out  what 
they  think  should  be  the 
final  U.S.  proposal  The 
Federal  Communications 
Commission  considers 
these  views,  and  adds  to 
this  their  outlook.  They 
then  publish  notices  of  pro- 
posals. Eventually,  the  FCC 
will  come  up  with  their 
final  position  paper  and 
hand  it  to  the  State  Depart- 
ment to  begin  the  dip- 
lomatic process. 

Much  of  the  nitty*gritty 
negotiations  are  taking 
place  now  and  the  actual 
ITU  WARC  wilt  seem  anti* 
climactic. 

Let's  examine  the  make- 
up of  the  people  who 
can  attend  these  world 
meetings-  Official  voting 
delegates  from  the  various 
nations  have  not  yet  been 
selected  but  soon  will  be. 
If  the  makeup  of  the  last 
conference  in  1959  can  be 
any  indication  of  what  to 
expect,  countries  will  in- 
clude various  governmen- 
tal department  heads  who 
will  administer  radio  law 
back  home.  In  our  case,  the 
military  brass  would  be  in- 
cluded along  with  people 
from  the  FCC. 

Representatives  of  pri- 
vate companies  can  par- 
ticipate along  with  people 
from  international  radio 
organizations.  They  can 
act  as  observers  only  after 
obtaining  the  approval  of 
the  participating  govern* 
ments.  They  can  look  on 
from  the  audience  but  can- 
not actively  have  a  say  in 


policymaking  decisions. 

On  opening  day,  dis- 
tinguished members  will 
be  seated  in  a  large  room 
of  the  ITU  building  to  carry 
out  the  formal  opening 
ceremonies.  A  chairman 
will  be  selected  who  will 
organize  committees  that 
will  meet  separately  to 
take  up  the  various  issues 
that  brought  them  there. 
Each  nation  wilt  register 
members  for  participation 
in  the  discussion  groups. 
They  will  be  meeting  near 
Geneva  during  the  length 
of  the  assembly.  Toward 
the  end  of  the  conference, 
members  will  once  again 
assemble  en  masse  to  vote 
on  the  new  international 
radio  law. 

In  addition  to  commit- 
tee meetings,  there  are 
plenty  of  social  functions 

to  attend.  Much  arm 
twisting  is  done  in  between 

the  wine  and  the  cheese 
dip.  The  diplomatic  of- 
ficials of  the  world  do  have 
a  tradition  of  combining 
business  with  pleasure. 
Where  else  but  in  Geneva, 
which  is  the  world  head- 
quarters of  our  many 
organizations   [Red   Cross, 


Boy  Scouts,  etc.)  that  serve 
humanity,  should  such 
splendid  parties  be  thrown. 
These  occasions  are  legal 
ground  for  the  con- 
ference's  observers  to  con- 
fer with  the  delegates  on 
various  matters. 

When  the  treaty  is  con- 
cluded and  the  officials  ap- 
prove, then  it  is  up  to  each 
member  nation  to  ratify 
the  agreement  In  the  U.S., 
our  Senate  has  to  approve 
the  final  document.  Our 
services  in  the  communica- 
tions field  do  not  have  to 
abide  by  the  new  regula- 
tions until  our  government 
makes  it  law.  One  ratifica- 
tion process  took  our  of- 
ficials in  Washington 
several  years  to  give  it  their 
seal  of  approval  Until 
ratification,  we  continue  to 
operate  under  the  present 
treaty 

U.S.  Preparations 

U.S.  Preparations  have 
been  actively  under  way 
since  1975  at  the  Depart- 
ment of  State,  the  Federal 
Communications  Commis- 
sion, and  the  Office 
of  Telecommunications 
Policy  (now  known  as  the 

Unltid  Nations  Photo 


National  Telecommunica- 
tions and  Information  Ad- 
ministration).  The  FCC  is 
charged  with  primary 
responsibility  for  develop- 
ing non-federal  user  re- 
quirements. The  NTIA  is 
primarily  responsible  for 
federal  government  re- 
quirements. 

The  FCC  and  NTIA  are 
developing  the  different 
needs  and  requirements  of 
the  US  spectrum  users 
through  close  consultation 
with  each  other  and  with 
the  State  Department.  In- 
dustry and  general  public 
interests  have  been 
solicited  by  means  of  a 
series  of  public  Notices  of 
Inquiry,  issued  by  the  FCC. 
Eight  Notices  of  Inquiry 
have  been  issued  and  addi- 
tional Notices  may  be 
released  in  the  future  The 
Notices  treat  different 
aspects  of  WARC  planning, 
most  notably  changes  in 
the  international  table  of 
frequency  allocations. 

How  Much  Can  World 
Politics  Affect  Amateur 
Radio  Bands? 

There  has  been  specula- 
tion on  how  other  nations 


Headquarters  of  the  Internationa f  Telecommunkathn  Union  in  Geneva,  Switzerland. 


214 


view  amateur  radio.  The 
concern  seems  to  be 
focussed  on  how  third- 
world  governments  place 
their  communications  pri- 
orities. At  the  time  of  past 
WARCs,  many  of  these  na- 
tions were  colonies  of  the 
western  nations  and  the 
voting  power  of  these  col- 
onies was  held  by  their 
respective  ruling  coun- 
tries. The  situation  has 
changed  enormously  since 
the  1959  WARC;  the 
number  of  independent  na- 
tions has  increased 
dramatically.  In  Sep- 
tember of  1979,  154  na- 
tions wilt  cast  votes  on  the 
many  issues  facing  WARC. 
Many  of  them  will  be  na- 
tions which  were  not  yet 
independent  at  the  time  of 
the  last  WARC.  The 
balance  of  power  has 
shifted. 

These  new  nations  are 
rapidly  reaching  the  period 
when  their  development 
creates  economic  and 
social  needs  to  fill.  As  their 
domestic  and  foreign 
goals  becorne  clear, 
amateur  radio  may  not  be 
so  important  to  them  when 
compared  with  commer- 
cial, military,  and  govern- 
mental interests. 

If  you  look  through  the 
list  of  those  who  hold 
amateur  licenses  in 
developing  nations,  you'll 
find  that  many  of  the 
licenses  are  held  by 
foreign  nationals.  In  some 
nations,  you'll  find  native- 
born  hams  in  the  govern- 
ment or  military,  but  not  in 
the  population  at  large. 
Most  African  authorities 
consider  hamming  to  be  a 
"white  man's  hobby"  and 
they  discourage  the 
population  from  getting  in- 
volved with  it.  In  many 
cases,  licenses  simply  are 
not  issued  to  natives  of 
these  nations. 

Can  world  politics 
hinder  amateur  radio?  This 
is  a  hard  situation  to  get  a 
handle  on.  One  would 
think  that  the  U.S.5.R,  bloc 


might  be  against  ham 
radio,  but  in  1959  a  very 
curious  thing  happened. 
Most  of  the  ITU  members 
were  attempting  to  slice 
up  the  ham  bands  and 
even  threaten  amateur 
radio's  existence.  Then, 
with  the  aid  of  the  Com- 
munist votes  and  our 
hemispheric  friends,  we 
gathered  enough  support 
to  salvage  the  service 
without  losing  a  kilohertzl 

Last  time  we  went  into 
the  conference  not  asking 
for  anything  special,   like 
the     expansion     of     our 
bands.  WARC  79  may  see 
us    asking    for    additional 
bands    due    to    some    ser- 
vices moving  up  to  com- 
munication  satellites   and 
thus     abandoning     many 
shortwave  frequencies.  We 
may  hear  some  countries 
suggest    that    CB    should 
become    a    world    service 
and  share  the  ham  bands 
with  us.  The  political  situa- 
tion  being   played   out  at 
the  U.N.  and  its  agencies 
may  spill  over  to  Geneva. 
This     would     put     the 
western  world  into  opposi- 
tion with  the  third  world 
just     because     it     is    the 
fashionable  thing  to  do.  A 
44-nation  African  bloc  ap- 
pears ready  to  vote  for  a 
set    of    world    frequency 
allocations     which     will 
mean   drastic  cuts  in  the 
amateur     bands.     Many 
other    third-worid    govern- 
ments will  probably  follow 
this  lead. 

We  do  have  strong  sup- 
port in  some  countries,  in- 
cluding at  least  one  in 
Africa.  Liberia  is  a  staunch 
advocate  of  ours  because 
of  the  way  ham  radio  aided 
that  country  during  an 
epidemic.  Central  and 
South  American  govern- 
ments know  of  our  value  in 
providing  disaster  and 
emergency  communica- 
tions. We  do  have  friends 
who  will  stand  by  us,  but 
the  world  is  changing  and 
only  time  will  tell  what  will 
happen.  ■ 


Call 

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215 


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-I'F 


Fig.  4.  Tfiode  voltage  polar- 
ities. 


9ELF    BIAS 

B 


fig.  5,  Cathode  bias. 

Class  B  is  biased  to  the 
cutoff  point  of  the  tube 
curve,  draws  current  onty 
when  there  is  a  signal  ap- 
plied, amplifies  only  part 
of  the  input  signal  per  tube 
(one  half),  has  an  output 
that  is  proportional  to  the 
input,  and  is  considered  a 
linear  amplifier  It  is  also  a 
more  efficient  use  of 
power. 

Class  C  is  biased  beyond 
the  cutoff  point,  only 
draws  current  and  has  out- 
put when  driven  into  con- 
duction, amplifies  a 
smaller  portion  of  the  in- 
put signal  (less  than  half], 
has  the  largest  and  most 
distorted  output,  and  is  not 
considered  a  linear  ampli- 
fier It  is  the  most  efficient 
use  of  the  available  power. 

Class  AB  is  a  variation  of 
the  class  B  amplifier  that  is 
not  fully  biased  to  cutoff. 
It  draws  some  current  at  all 
times,  is  more  efficient 
than  class  A,  but  less  than 


class    B,    and    is    less   dis- 
torted than  class  B- 

That's  it  for  tube  bias 
classes.  There  is  one  other 
thing  about  tube  bias 
which  should  be  men- 
tioned, Most  tubes  will  cut 
off  with  sufficient  minus 
bias. 

There  is,  however,  one 
kind  of  tube  that  was 
designed  so  that  it  woutd 
not  cut  off  in  operation 
This  is  the  remote-cutoff 
tube  (Fig.  9).  This  was 
designed  for  stages  like  rf 
and  i-f  amplifiers  where 
avc  (automatic  volume 
control)  action  is  desired.  A 
strong  signal  would  bias  a 
normal  tube  to  cutoff  and 
the  set  would  go  dead,  The 
remote-cutoff  tube  does 
not  cut  off.  It  just  con- 
tinues to  reduce  the  gain. 
Strictly  speaking,  that  is 
not  a  class  of  bias,  but  it 
does  have  an  odd  tube 
curve  and  function. 

Now  then,  we  come  to 
transistors.  Here's  where 
we  start  to  have  troubles. 
Once  again  the  flim-flam 
factor  appears. 

The  transistor  was  a 
triode— nothing  more.  Not 
only  that,  it  was  a  triode 
with  alt  the  troubles  the 
tube  triode  had  and  a  few 
more  that  tubes  never 
thought  of.  It  was  the  new 
toy  that  had  to  be  sold  and 
a  great  deal  of  effort  went 
into  making  it  seem  like 
anything  but  a  triode.  All 
the  bad  things  they  safd 
about  triodes  came  back  to 
haunt  them.  And  they  were 
trying  to  do  all  the  things 
with  a  triode  that  they  were 
using  multi-element  tubes 
for. 

There  were  a  few  prob- 
lems,   In    a    well-designed 


circuit,  a  transistor  can  be 
a  reliable  circuit  element, 
but  many  of  the  circuits 
were  not  designed  well  and 
got  worse  as  they  aged. 
This  quickly  gave  tran- 
sistors a  well-deserved  bad 
name.  They  had  oversold 
their  retiability  and  rushed 
into  production  with  too 
many  transistor  circuits 
riding  right  on  the  edge  of 
their  technology.  To  sell 
them,  they  worked  very 
hard  to  disassociate  tran- 
sistors from  anything  to  do 
with  tubes,  particularly  the 
triode. 

As  far  as  possible,  new 
terms  were  given  and  even 
new  ways  of  arranging  the 
schematics  so  that  tran- 
sistor schematics  often 
have  circuit  elements  in 
different  positions  than  a 
tube  schematic  would.  All 
this  overlooked  one  simple 
thing:  There  are  far  more 
similarities  between  tubes 
and  transistors  than  there 
are  differences.  We  will 
need  to  fill  in  just  a  few 
more  tube  items  before  we 
can  fill  in  the  blanks.  There 
were  some  factors  which 
were  deliberately  drawn  to 
widen  the  gulf  between  the 
two  when,  in  fact,  they  are 
just  opposite  ends  of  the 
same  stick. 

Way  back,  ft  was 
thought  that  the  tube  grid 
did  not  draw  current,  par« 
ticularly  in  the  class  A 
amplifier  stage  and  the  ear- 
ly regenerative  stages  and 
so  forth.  One  theory  held 
that  bias  was  a  static 
charge,  a  potential  dif- 
ference as  at  the  poles  of  a 
battery  (which  often  sup- 
plied the  bias  voltage). 
While  the  voltage  ap- 
peared as  a  static  charge  at 


the  poles  of  the  battery 
and  at  the  tube  elements, 
no  actual  current  flowed. 
It  was  not,  in  that  sense,  a 
complete  circuit. 

But  unless  the  Supreme 
Court  has  declared  Ohm's 
Law  to  be  unconstitu- 
tional, grids  draw  current 
All  grids  draw  current. 

The  problem  was  that 
the  grid  resistance  might 
be  several  million  Ohms 
and  the  voltage  only  a  few 
volts.  The  current  was  so 
slight  that  it  couldn't  be 
measured  without  upset- 
ting the  circuit. 

Much  has  been  made  of 
saying  that  the  tube  is  a 
voltage-operated  device 
and  the  transistor  is  cur- 
rent-operated, as  if  this  was 
something  different.  Bunk! 
There  is  voltage  and  cur- 
rent floating  around  in 
both  of  them.  You  can't 
have  one  without  the 
other,  no  matter  who  says 
what.  Why  then  is  there  the 
big  problem?  It's  a  matter 
of  impedance  and  sloppy 
wording.  Here,  we  will 
have  to  use  impedance  and 
resistance  interchangeably 
because  we  are  dealing 
with  both  the  static  dc 
voltages  and  the  signal 
voltages. 

It  is  a  matter  of  conve- 
nience to  speak  of  the  tube 
circuit  as  voltage-operated 
and  the  transistor  as  cur- 
rent-operated because  of 
the  resistance  involved. 
For  convenience,  think  of  it 
as  an  amount  of  power, 
even  though  it  may  be 
small.  The  tube  circuit  has 
a  high  resistance.  The 
signal  is  higher  voltage, 
which  means  that  the  cur- 
rent will  be  very  small.  The 
equivalent  signal  in  a  tran- 


'-s     -? 


Fig.  8.  Grid' leak  bias. 

sis  tor  is  across  a  lower 
resistance,  which  means 
that  the  voltage  on  it  will 
be  smaller  but  the  current 
higher. 

You  have  seen  this 
before  with  antennas.  An 
end-fed  wire  is  a  high  im- 
pedance point,  which 
means  a  high  voltage  point 
but  low  current.  A  dipole  is 
a  low  impedance  feed- 
point,  which  means  a  lower 
voltage  but  a  high  current. 
That's  all  you  have  with 
tubes  and  transistors,  just 
a  matter  of  convenience 
when  speaking  of  signal 
transfer  There  is  voltage 
and  current  associated 
with  both  circuits. 

You  will  also  see  signal 
sources  referred  to  as  a 
current  source  or  a  voltage 
source.  It's  the  same  thing. 
The  voltage  source  will  be 
higher  impedance  and  the 
current  source  will  be- 
lower. 

Now  we  come  to  the 
matter  of  transistor  bias. 
The  classes  of  bias  are  the 
same  for  transistors  as  for 
tubes,  and  the  definitions 
hold  true  for  them,  too. 
The  transistor  also  has  a 
linear  portion  of  its  "cur- 
rent-transfer" curve,  and  a 
cutoff  point.  We  do  have 
to  make  a  distinction, 
though.  Here,  we  are 
speaking  of  the  normal  bi- 
polar transistor,  not  the 
field-effect  type  which  will 
be  dealt  with  later- 
While  the  classes  of  bias 
are  the  same,  they  are 
arrived  at  in  a  slightly  dif- 
ferent manner.  Even 
though  the  transistor  is  on 
the  other  end  of  the  stick 
from  the  tube,  in  one  way  it 
behaves  exactly  opposite 
from  the  tube. 

If  you  look  at  the  tube 
curve,  you  will  notice  that 
when  a  tube  receives  zero 


-* 


RI 


F   SATURATIOIII   f>DMT 


Fig.  9.  Typical  remote-cutoff  tube  curve. 


bias,  it  will  draw  the  max- 
imum current,  which  can 
be  unhealthy.  The  tube 
must  be  biased  just  to  sit 
there.  The  transistor  is  just 
the  opposite.  Without  bias, 
it  will  just  sit  there  and  be 
cut  off.  The  trick  is  how 
you  bras  it. 

Look  at  the  circuit  in  Fig. 
10.  Resistor  R1  is  the  load 
resistance  for  the  tran- 
sistor. It  has  the  same  func- 
tion as  the  tube  load 
resistance  (RL},  R2  and  R3 
are  different  ways  to  in- 
troduce bias  to  the  tran- 
sistor. R2  is  one  of  the  more 
stable  ways  to  do  it-  Tran- 
sistors are  prone  to  a 
number  of  screwball  bad 
habits.  Thermal  runaway  is 
one.  When  it  gets  hot,  it 
draws  more  current  and 
gets  hotter  and  draws  even 
more  current  and  pffft! 

Either  resistor  will  allow 
a  certain  amount  of  bias 
current  to  flow  in  the  base 
circuit,  which  is  how  the 
transistor  gets  biased. 

R2  gets  the  current  from 
the  collector  resistor.  If  the 
stage  draws  more  current, 
the  voltage  drops  and  the 
current  drops  through  R2, 
helping  to  stabilize  the  col- 
lector current  That  is  a 
simplified  circuit,  but  it 
would  work  as  a  simple 
amplifier. 

Fig.  11  shows  a  few  more 
resistors  in  there.  R3  is  the 
emitter  resistor  which  is 
usually  bypassed.  It  also 
has  a  stabilizing  effect  on 
the  stage.  Often  its  value  is 
similar  to  many  small  sig- 
nal tube  stages,  although  it 
is  not  exactly  the 
equivalent  of  the  cathode 
resistor.  R4  is  something 
like  a  load  on  the  grid,  but 
also  helps  the  stability  of 
the  stage.  Its  value  is  usual- 


ly in  the  range  of  one-tenth 
the  value  of  R2. 

Now  we  come  to  the 
name-games  people  play. 
With  the  modern  tube,  you 
have  the  cathode,  the  grid^ 
and  the  anode  or  ''plate/' 
Diodes  have  long  had  a 
cathode  and  an  anode,  but, 
when  they  got  to  the  tran- 
sistor, they  had  to  think  up 
some  new  names  and  came 
up  with  emitter,  base,  and 
collector.  That's  not  too 
bad,  just  a  little  farfetched. 

Then  came  field-effect 
transistors  [FETs),  They  are 
the  ones  that  think  they  are 
tubes.  We  get  back  to  volt- 
age-operated again.  Also 
they  wanted  to  disasso- 
ciate them  from  those  nas- 
ty old  transistors  that  gave 
so  much  trouble. 

FETs  are  compared  to 
tubes  because  they  are  a 
comparatively  high  im- 
pedance device,  more  like 
tubes  than  transistors.  The 
words  "field  effect''  are 
used  because  it  is  the  field 
of  the  input  signal  voltage 
that  makes  them  work. 
They  seem  much  more  like 
tubes  than  bipolar  tran- 
sistors. It  would  never  do 
to  use  the  same  names  for 
their  new  toy,  so  they  came 
up  with  source,  gate  and 
drain.  How  imaginative! 

You  still  have  the  same 
classes  of  bias  possible  and 
bias  is  accomplished  with 
FETs  much  the  same  way  it 
Is  with  tubes. 

There  are  applications 
with  some  tubes  and  FETs 
that  don't  use  an  external 
bias.  These  are  small-signal 
amplifier  stages.  The  usual 
high  load  resistance  limits 
the  current  as  well  as  pro- 
viding the  load.  The  tiny  in- 
put signal  to  the  stage  has 
the  effect  of  riding  in  a 


m 


Fig.  10,  A  simple  transistor 
bias  circuit 

linear  portion  of  the  curve 
over  a  short  distance.  Even 
so,  the  tube  does  provide  a 
tiny  amount  of  self-bias, 
too. 

Which  brings  us  back  to 
the  beginning,  The  tran- 
sistor is  just  another  kind 
of  triode.  Tube  and  tran- 
sistor bias  do  the  same  job 
for  the  same  reason.  They 
just  do  it  somewhat  dif- 
ferently. 

A  tube  is  biased  by  ap- 
plying a  negative  voltage 
to  the  grid  or  by  making  the 
cathode  more  positive 
than  the  grid. 

A  bipolar  (ordinary)  tran- 
sistor is  biased  by  applying 
a  small  current  to  the  base, 
or  by  biasing  the  emitter 
with  respect  to  the  base. 

An  FET  is  biased  roughly 
the  same  way  a  tube  is  bi- 
ased. The  voltage  and  cur- 
rents will  be  smaller, 
though. 

The  FET  either  biases  the 
gate  negative  or  the  source 
positive  with  respect  to  the 
gate.  If  an  N-type,  the 
reverse  if  a  P-type. 

While  this  discussion  has 
been  a  little  shy  on  num- 
bers and  practical  appli- 
cations, it  should  help  you 
make  sense  of  the  more 
detailed  descriptions  of 
tube  and  transistor  theory: 
a  backbone  upon  which  to 
hang  more  detail.  M 


Fig.  71.  Conver^tional  trarh 
sistor  bias  afrangement 


219 


f 


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Build  the  Flexi-Filter 


a  very  active  device 


Donald  Morur  W3QVZ 
3663  Hipsky  Mtit  Road 
Woodbine  MD  21797 


Ever  have  need  for  an  ac* 
tive  filter  with  tunable 
multiple  outputs,  i.e.,  high- 
pass,  tow-pass,  bandpass, 
and  a  very  sharp  rejection 


notch?  The  filter  described 
is  a  "state  variable  filter" 
(svf).  The  5vf  described 
here  has  an  operating  fre- 
quency of  6  Hz  to  60  kHz. 
A  good  discussion  of  this 
type  of  filter  may  be  found 
in  the  IC  Op- Amp  Cook- 
book by  Walter  |ung  and 
the  Active  Filter  Cookbook 
by  Don  Lancaster.  This  svf 


The  various  control  functions  and  input/output  connec- 
tions can  be  seen  in  this  photo.  The  various  filter  functions 
are  available  simultaneousiy  at  the  various  phono  jacks. 
For  those  only  interested  in  general  communications  use, 
the  top  and  bottom  frequency  ranges  may  not  be  wanted 
Ir}  this  case,  only  two  values  of  CI  and  C2  would  be  re- 
quired. .022  and  .0022  uF  capacitors  could  yield  a  range  of 
60  to  7000  Hz. 


uses  5  op  amps.  Four  of  the 
op  amps  are  contained  in 
the  quad  3403  unit  and  U5 
is  a  single  LM318.  (See  Fig. 

U 

Functionally,  the  state 
variable  filter  uses  three  or 

four  op  amps.  Two  op 
amps,  U2  and  U3,  are  con- 
nected as  inverting  in- 
tegrators in  cascade.  The 
output  of  the  second  op 
amp  integrator  is  unity 
gain,  and  is  inverted  and 
fed  back  to  the  input  of  the 
first  integrator,  U2.  There  is 
also  a  feedback  loop  from 
the  first  integrator  back  to 
its  own  input  to  provide  a 
controllable  amount  of 
damping 

The  input  summing 
stage,  U1,  combines  oscil- 
latory feedback,  damping, 
and  input  signals.  If  U1  has 
properly  scaled  input  and 
feedback  resistors,  you  can 
independently  control  cir- 
cuit gain,  frequency,  and 
damping.  The  function  of 
U5  is  to  correct  the  band- 
pass output  phase  so  all 
three  outputs  will  be  out  of 
phase  at  resonance,  and  in- 
crease the  gain  of  the 
bandpass  channel  by 
about  3  dB,  thereby  mak- 
ing the  gain  of  all  three  out- 
puts equal  within  their  re- 
spective passbands    From 


lung's  IC  Op-Amp  Cook- 
book^ page  337,  for  the  cir- 
cuit in  question:  Given  fi, 
Ql,  and  Ho  (passband 
gain),  select  CI  (C2)  Ri  " 
1/(2TTfcC1).  Choose  R3,  R4 

=   QR3,  R7   =  R6Q/Hobp 

Example:  f^  =  723  Hz,  Q 
-  20,  Ho  =  Q.  If  RI  =  R2 
and  CI  =  C2  and  RS  =  R6 
=  R7  =  R8  =  10k,  fc  = 
1/(2t[R1C11,  Q  =  R4/R3, 
Hobp  =  R6/R7[QL  CI,  C2 
=  1/(2T!Rlfc)  =  .022  uF  for 
RI,  R2  =  10k, 

Construction 

As  can  be  seen  from  the 
accompanying  photos,  the 
unit  is  housed  in  a  Bud 
sloping-panel  cabinet, 
Model  AC1613.  A  piece  of 
single-clad  phenolic  board 
was  utilized.  An  isolated- 
pad  drill  mill  was  used  to 
produce  isolated  pads 
through  which  Vector 
"Mini-Klip"  pins  were 
pressed  in  and  soldered. 
The  layout  and  wiring  are 
not  critical. 

Filter    Measurements    and 
Operation 

The  operating  controls 
of  the  filter  are  self- 
explanatory  and  may  be 
observed  in  the  accompa- 
nying photos.  The  curves  in 
Fig.  2  were  made  as 
described    in    the    block 


222 


diagram    of    Fig.    2.    The 
audio    oscillator    output 
was  set  at  100  mV  at  a  fre- 
quency of  1  kHz.  The  fitter 
attenuator    was    then    ad- 
justed to  produce  250  mV 
output.  Setting  250  mV  = 
0  dB,    the    low-pass   filter 
curve  was  plotted.  As  in- 
dicated in  Fig.  2,  the  Q  con- 
trol  must  be  adjusted  by 
trial    and    error    for    the 
smoothest   (without   peak- 
ing)   roll-off.    The    roll-off 
was  also  observed  with  a 
swept    70    to    10,000    Hz 
audio  signal  applied  to  the 
filter  (see  Appendix).  The  Q 
control  could  then  be  ad- 
justed   by    watching    the 
scope  presentation  for  op- 
timum roll-off  shape.  The 
same  routine  was  used  in 
the  plotting  of  Fig.  3.  The 
change  in  the  setup  in  the 
plotting  of  Fig.  4  involved 
changing  the   tuning   con- 
trol to  1.5  kHz  and  the  Q 
control  to  near  minimum. 
Thj^,  tuning  control  must  be 
very   carefully   set   at  1.5 
kHz    or    an    asymmetrical 
plot  will    result.    Examina- 
tion of  the  6  dB  points  of 
the  notch  plot  shows  a  Af 
considerably  underlOO  Hz. 
Fig,    5    setup    conditions 
were    10    mV    filter    input 
with   the  filter  attenuator 
adjusted  to  yield  40  mV  at 
the  bandpass  output  jack. 
The  tuning  control  was  re- 
checked   for   an    accurate 
1.5  kHz  setting  and  the  Q 
control  was  set  near  max- 
imum. This  curve  indicates 
a  Af  substantially  less  than 
200   Hz.   When   this    filter 
was  built,  no  attempt  was 
made  in  matching  the  resis- 
tor and  capacitor  values  in 
the   tuning   circuits   (com- 
ponents  with   asterisks    in 
schematic).    An    improve- 
ment  in    maximum    selec- 
tivity may  be  possible  by 
doing  this,  for  those  con- 
cerned with  obtaining  op- 
timum selectivity. 

Filter  Tests 

I  have  made  a  number  of 
listening  tests  on  my  Ken- 
wood R'599  receiver  with 
the  filter  interposed  be- 
tween the  receiver  output 


INPUT      fATTCNJ 


R7 


R5 


3  OK 


-^ 


laK 


^ 


500a 

— V%rti — 


CI  ""^  *R?  "C2 

,022  M&K       ,^  .022 


^h 


JTX 


R4 
iOk 


iOk  "O" 


^irX- 


-^  NOTCH 


^ 


BfiNDPfliS? 


HIGH 


?7  5 


5K     R, 


t'vVV- 


rh 


•;>-.  «-»;y  ■;•:•:< 


fig.  7.  Versatile  audio  filter  schematic  diagram  +  V  =  pin  14;  —  V  —  pin  7.  U1,  U2,  U3, 
U4  =  3403  quad  unit  U5  =  LM318.  Tune  with  *R1,  R2  =  ganged  10k  pot.  If  *Ct  C2  = 
.022  uF,  fc  =  723  N,  with  RF1,  R2  maximum.  Range  switch  not  shown.  CI,  C2  =  .0022, 
.022,  .22,  and  22  uF. 


(headphones  jack)  and  a 
pair  of  low-impedance 
headphones.  The  filter  will 
produce  as  much  as  2  volts 
rms  outpijt  into  a  low-im- 
pedance headphone  load 
with  only  a  few  mV  rms  in- 
put at  the  bandpass  output 
jack  of  the  filter,  with  the 
filter  attenuator  set  at 
minimum.  One  can  then  lis- 
ten to  sideband  signals 
with  typical  QRM  situa- 
tions and  hear  the  effect  of 
the  low-,  high-,  or  bandpass 
filters  by  varying  the  filter 
tuning  and  Q  controls.  The 
notch  output  was  very  ef- 
fective in  rejecting  CW 
signal  interference  when 
listening  to  phone  signals. 
The  receiver  output  was 
also  fed  through  the  filter 
to  a  separate  audio  power 
amplifier  driving  a  speaker 
to  compare  more  directly 
with  the  receiver's  own 
speaker  output.  There  was 
definite  improvement  in 
the  clarity  of  reception  of 
various  phone  signals  (SSBJ 
by  juggling  the  tuning  and 
Q  controls  and  listening  at 
various  filter  output  jacks. 
The  filter  was  not  as  selec- 
tive as  the  Kenwood  fixed- 
tuned  CW  filter  regarding 
CW  reception,  but  was  def- 
initely superior  as  an  ad- 
justable phone  filter.  The 
Kenwood  SSB  selectivity 
position  is  a  low-pass  filter 
rolling  off  rapidly  beyond 
2.5  kHz.  While  generally 
satisfactory,  under  ex- 
treme conditions  of  QRM, 


the  audio  filter  afforded 
definite  improvement  in 
speech  intelligibility  and 
reduction  of  prolonged  lis- 
tening  fatigue. 

Another  interesting  ap- 
plication for  the  audio  ex- 
perimenter would  be  as  an 
audio  sweep  marker.  By  in- 
terposing   the    filter    be- 


tween the  audio  preamp 
output  and  power  amp  in- 
put and  applying  a  swept 
audio  signal  to  the  audio 
system,  the  rejection  notch 
would  appear  on  the  scope 
presentation  as  a  narrow 
notch  in  the  sweep.  The 
position  and  depth  of  this 
marker  would  be  a  func- 


Q    CONTT^CJL 
SET  TO    HIQH 


Odfi  - 


to 


HEATH 


AUPIO 

FILTER 


HEflTH 
AKOIO 
VTVM 


;^di',asv 


AUOIO  osc 

OUTPUT-^O0mV 


\ 


1^    £0 

<t 

z 

LU 

K 

<    30 
4Q|- 


ATTENUATOR   SET    TO 
PROpUCe    S50mV    AT 
(_0W   PASS  OUTPUT   JACK 

TUNING    KNOe    SET 
FOR    HChz 

O    CONTROL    SET    FOR: 
SMOOTH    ROLL-OFF 
(SEE    4PP£N0tK} 


50- 


-L 


2  3 

FRegUENCY   {KHiJ 


Fig.  2.  Low-pass  filter  characteristics. 


QdB 


10 


o 


20 


5     30 
m 


40 


50 


Q    CONTROL 
SET   TO  WJGH 


\, 


J. 


100   £00  300  400  500  &00   70O  BOO  500    IK 

FREQUEMCV   (KHa) 


L4  K 


p-t-t;  -Wv-""  9  *fi?rK|K«  ♦■wacsMrK- ; 


■*  '^^"■K:^;:'^*c5^*'-my;:ytji^ 


Fig.  3,  High-pass  filter  characteristics.  The  same  test  condi- 
tions as  Fig.  1  were  used  except  for  250  mV at  the  high-pass 
filter  output  jack. 


223 


Miai^M^s^^^^tSfaSI^Ki4i^miiiii^mm 


Bottom  view  shows  copper-dad  phenolic  board  construction  as  explained  in  text 


tion  of  the  tuning  and  Q 
controls  respectively.  Any 
portion  of  the  audio  sweep 
could  then  be  read  from 
the  frequency  dial  on  the 
filter.  This  would  be  conve- 
nient for  measuring  roll-off 
rates  of  other  filters  under 
test  equalizers,  etc.  The 
audio  filter  tuning  dial  was 
calibrated  by  applying  a 
known  audio  frequency 
and  peaking  the  tuning 
control  (while  observing 
the  output  in  the  notch 
mode)  for  a  null.  This  mode 
was  used  since  it  has  the 


sharpest  tuning  indication. 

Conclusion 

The  application  of  the 
filter  is  limited  only  by  the 
imagination  of  the  user.  In 
the  notch  mode,  it  could 
meet  highly  selective  null- 
ing circuit  requirements 
such  as  tape-beep  cueing 
removal,  suppression  of 
QRM  in  SSB  and  CW  sig- 
nals, 60-120  Hz  hum  sup- 
pression, etc.  The  notch 
mode  could  also  be  used  as 
the  basis  for  total  har- 
monic  distortion   analysis 


measurements.  The  state 
variable  filter  makes 
available  an  active  filter 
with  high  stability,  predic- 
tability, and  wide  tuning 
range  at  a  very  moderate 
cost  and  relatively  easy 
construction. 

Appendix 

A  measurement  was 
made  (data  not  included) 
which  cor>sisted  of  apply- 
ing a  swept  audio  signal  to 
the  audio  filter.  The  source 
was  a  ''Clarkstan"  sweep 
frequency  phonograph 
transcription   played  back 


through  a  very  flat  Empire 
phono  pickup.  The  filter 
was  connected  at  the  out- 
put of  the  audio  power 
amplifier  and  an  oscillo- 
scope  was  connected  to  ex- 
amine  each  filter  ouput 
mode.  The  characteristics 
of  the  sweep  record  were  a 
Af  of  70  to  10,000  Hz,  at  a 
20  Hz  sweep  rate.  The  ef- 
fect of  the  Q  control  of  the 
high-  and  low-pass  filters' 
roll-off  rates  was  observed, 
The  roll-off  rate  could  be 
controlled  (increased  or 
decreased}  by  the  Q  con- 
trol, but  a  setting  yielding  a 
smooth  roll-off  was  set  to 
plot  Figs.  2  and  3.  Higher 
settings  of  the  Q  control 
were  employed  when  plot- 
ting the  bandpass  mode, 
Fig,  5.  The  dotted  lines  in 
the  plots  of  Figs.  2  and  3  in- 
dicate the  effect  of  raising 
or  lowering  the  Q  control 
settings,  High-Q  operation 
really  only  pertains  to  the 
bandpass  mode.  As  can  be 
seen,  an  excessive  Q  set- 
ting produces  a  hump  or 
peaking  in  the  low-  and 
high-pass  modes  near  the 
cut-off  frequencies-  Ex- 
cessive Q  in  the  notch 
mode  likewise  reduces 
notch  selectivity,  A  Q 
value  of  \^2/2  theoretically 
produces  minimal  peaking 
(Butterworth  response).  For 
those  desiring  more  de- 
tailed design  information 
on  the  state  variable  filter, 
as  well  as  other  types,  a 
copious  amount  of  data  is 
available  in  the  aforemen- 
tioned books  by  Jung  and 
Lancaster.  B 


lu 


m 


50  r 


40  - 


30- 


20 


10  - 


OdB 


10 


13 


■0^^B 


Fig.  4.  Notch  filter  characteristics.  The  same  test  condi- 
tions as  in  Fig.  1  were  used  except  the  tuning  was  set  for  1.5 
kHz  and  Q  control  was  set  for  best  notch  (near  minin}um 
Q  settingl  See  Appendix. 


Fig.  5,  Bandpass  filter  characteristics.  The  same  test  condi- 
tions as  Fig.  7  were  used  except  10  mV  input  to  filter,  at- 
tenuator set  for  40  mV  output  for  bandpass  output  jack, 
tuning  control  peaked  at  IS  kHz,  Q  control  set  near  max- 
imum. See  Appendix. 


224 


#v- 


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FREIGHT:  ALL  SHIPPING  CHARGES  "COLLEa"  -  F.O.B.  WATERTOWNl 


uu1iX:^'^T,:::nru.,.       "America's  Most  Reliable  Amateur  Radio  Dealer" 


PHONE  NO.  (605)-886.7314      P.O.  BOX  73     WATERTOWN.  SOUTH  DAKOTA  57201 


The  Klassic  Kilowatt 


four  811  As  do  it 


Dave  Ingram  K4TWJ 
Eastwood  Village  No.  604N 
Rt,  //.  Box  499 

BirmmghQm  AL  352 10 


One  of  the  most 
popular  rf  amplifier 
circuits  in  use  by  today's 
amateurs    is    a   grounded- 


grid  configuration  of  S11A 
tubes.  Four  of  these  tubes 
can  provide  the  basis  of  a 
flexible  and  economical 
amplifier  which  uses  readi- 
ly available  parts,  operates 
from  home  brew  110-volt 
power  supplies,  and  is  only 
2  dB  weaker  than  a  large, 
power-consuming  2  kW 
unit.    My    previous    ex- 


Fronf  view  of  classic  amplifier  shows  R,L  Drake  cabinet 
and  knobs.  Illuminated  Heathk it-type  meter  is  modified  to 
read  amplifier  plate  current,  grid  current  and  relative  out- 
put 


perlences  with  ''legal 
limit"  amplifiers  have  been 
a  combination  of  back- 
breaking  power  supplies, 
special  220  V  ac  lines, 
elaborate  cooling  systems, 
and  offensive  TVL  Few 
problems  have  been  expe- 
rienced with  this  811A 
amplifier,  however,  and  I 
still  have  plenty  of  power 
for  competitive  operation 


in  DX  pileups. 

The  circuit  (Fig  1)  of  my 
amplifier  is  not  a  new 
design.  It  has  been  used 
(and  proven!)  in  equipment 
for  several  years.  A  very 
similar  circuit  is  used  in  the 
Collins  30L  1  linear  ampli- 
fier. The  difference  in  my 
unit  is  its  layout  and  design 
for  station  compatibility. 
Rather  than  using  a  surplus 


Classic  amplifier  in  service  and  operating  normally.  The  4 
817  As  add  a  soft  glow  to  any  ham  shacL  Room  is  dimly  il- 
luminated for  slow  scan  TV  operations. 


226 


»*^  OUTInJT 


COIL  DATA:  LI  (10  METERS^-  tf^'* 
COPPER  TUBING.  1'  LONG  BV 
Vh"  DIA>.  7  TURNS-  L2:  B  &  W 
3905-A.  4"  LONG  BY  2W  DiA..  20 
TP1,  TAPPED  FOR  15.  20.  AND  40 
METERS.  Zt,  22  fPAHASlTiC 
SUPPRESSORS)  4  TURNS  NO  16 
WOUND  ON  47  OHM.  2  WATT  RE- 
SJSTOR. 


1 1  D  VAC 


NOTE:  Rt  THROUGH  R5  ARE 
2DIL,  20'WATT.  CI  THROUGH  G5 
ARE  200  UF.  600  VOLT. 


■►rO  MEtER  SWITCH  ©PLATE 


Fig.  1.  Classic  rf  amplifier  schematic  diagram. 


enclosure  for  the  amplifier, 
an  empty  cabinet  that 
matched  my  transceiver 
was  purchased  directly 
from  the  manufacturer. 
Matching  knobs  were  also 
purchased  from  the  same 
manufacturer.  In  addition 
to  working  beautifully,  the 
completed  amplifier 
blends  perfectly  with  my 
Other  station  equipment. 
The  overall  result  (which 
includes  similarly  matched 
stow  scan  TV  gear)  Is  a 
''commerciaT'  appearing 
setup  that's  enjoyable  to 
own  and  operate.  The  in- 
formation presented  in  this 
article  is  intended  to  serve 
as  a  guideline  for  others 
desiring  to  construct 
amplifiers,  antenna  tuners, 
monitors,  etc.,  which  may 
also  match  their  particular 
setup. 

Amplifier    Mechanical 
Details 

The  amplifier's  811  As 
are  mounted  horizontally 
in  the  cabinet  and  all  input 
circuitry  is  mounted  in  the 


81 1  As'    rear-supporting 
chassis.  A  bottom  plate  is 

fitted  to  this  chassis,  thus 
totally  isolating  input  and 
output  signals.  This  design 
eliminates  the  necessity  of 
neutralizing  the  amplifier. 
Four  pieces  of  3-inch  metal 
channel  (I  used  Seezac 
plates)  are  fitted  together 
and  used  as  a  framework 
for  the  amplifier.  The 
upright  rear  chassis  and 
front  panels  are  bolted  to 
this  frame,  as  shown  in  Fig. 
2.  All  the  amplifier's  out- 
put circuitry  is  mounted  rn 
the  center  of  this  "free  air" 
space.  Exact  size  of  the  ver* 
tically  mounted  rear  chas- 
sis and  metal  framework 
varies  with  the  specific 
cabinet  used  to  house  the 
amplifier  A  small  minibox, 
with  holes  for  the  front 
panel  meter  and  incoming 
wires,  is  used  as  an  rf-proof 
meter  case.  The  meter 
switch  and  the  meter's 
pilot  lamp  are  also  en- 
closed by  this  case.  The 
plate-tuning  and  load  ca- 
pacitors are  surplus  units 


which  mount  directly  to 
the  amplifier's  front  panel. 
A  10  meter  tank  coil  is 
mounted  between  the 
plate-tuning  capacitor  and 
bandswitch,  while  the 
larger  tank  coil  mounts 
behind  the  bandswitch. 
Both  coils  are  supported 
by  their  leads.  A  small 
phonograph  motor  fan, 
mounted  on  the  amplifier's 
left  side,  cools  the  tubes 
during  use.  Sub-chassis 
mounting  of  the  811  As  is 
accomplished  by  using 
long  screws  and  spacers,  as 
shown  in  Fig.  3.  A  similar 
arrangement  permits  all 
rear  panel  amplifier  con- 
nections to  protrude 
through  the  removable 
rear  chassis  plate. 

Due  to  the  high 
temperatures  produced  in- 
side 811As  during  norma! 
service,  their  rectangular- 
shaped  plates  should  be 
situated  vertically  for 
structural  support,  as 
shown  in  Fig.  4.  This  will 
prevent  a  hot  filament 
from  falling  against  a  grid 


or  plate, 

A  local  sheet  metal  shop 
cut  and  drilled  the  ampli- 
fier's front  panel  for  five 
dollars.  1  merely  painted 
the  panel  to  match  my 
TR-4  and  mounted  it  on  the 
amplifier.  The  amplifier's 
framework  is  directly 
mounted  in  the  bottom 
part  of  the  TR-4  cabinet, 
and  a  thin  piece  of  extrud- 
ed aluminum  covers  the  in- 
side of  this  bottom  to  pre- 
vent TVL  The  rectangular 
slots  in  the  bottom  part  of 
the  cabinet  would  allow  rf 
to  "leak  out/'  but  the 
round  holes  in  the  extruded 
aluminum  prevent  rf  leak- 
age. 

Amplifier  Circuit  Delails 

As  previously  men- 
tioned, the  basic  circuit  of 
this  amplifier  has  been  in 
use  by  amateurs  for  several 
years.  Similar  circuits  have 
also  appeared  in  many 
amateur  publications  and 
handbooks.  The  minor 
variations  of  components 
in    each    schematic    are 


227 


interior  view  of  kilowatt  amplifier  reveals  layout  of  components  discussed  in  text  Note 
eyctruded  aluminum  fining  in  bottom  of  cabinet  for  TV  I  reduction. 


prime  examples  of  the 
amplifier's  flexibility. 
While  some  811A  circuits 
include  tuned  inputs,  my 
unit  simply  feeds  incoming 
rf  directly  to  the  811 A 
filaments  through  a  .01  uF 
capacitor.  Naturally,  tuned 
inputs  for  each  band  can 
be  included  if  desired. 
Suitable  filament  chokes 
which  may  be  used  with 
the  amplifier  are  the  B&W 
FC15A  and  FC25A  or  Ami- 
don's  new  filament  choke 
kit.  The  filament  choke  in 
my  particular  amplifier  is 
an  SB'200  replacement 
type  obtained  from  Heath- 
kit 


Although  a  B&W  851 
tank  coil  and  bandswitch 
assembly  may  be  used  in 
this  amplifier,  I  used  a 
4-inch  section  of  B&W 
3905  coil  stock  and  a 
separate  10  meter  coil  Ap- 
proximate tap  positions  for 
each  band  were  located  us- 
ing a  grid-dip  meter.  Then, 
exact  positions  were  lo- 
cated by  moving  these  taps 
±3  turns  and  noting  the 
corresponding  change  in 
output  power.  Presently, 
the  amplifier's  20  meter 
output  power  is  750  Watts. 
The  bandswitch  is  a  rela- 
tively heavy-duty  unit  ob- 
tained at  a  hamfest  bargain 


f  Ait 


TANK  COiL- 


p — s — p — s 


table.  Any  porcelain  switch 

with  large  contacts  should 
work  equally  well 

T-R  switching  and  811 A 
biasing  is  accomplished 
through  the  use  of  a  —125 
V  dc  divider  network, 
which  consists  of  a  sen- 
sitive 10k  Ohm  plate  relay 
and  a  7500  Ohm  pot.  This 
network  is  ungrounded 
during  receive,  thus  apply- 
ing approximately  —125 
volts  to  the  811 A  grids  as 
cut-off  bias.  When  the 
transceiver's  relay  grounds 
this  T'R  line,  tube  bias  is 
reduced  to  approximately 
—  4  volts.  The  pot  should 
be  adjusted  to  produce  60 
or  70  mA  of  idling  current 
on  the  811  As  [transmit 
mode  with  no  input  driving 
signal),  and  the  amplifier  is 
ready  for  action. 


Power  Supply  Details 

Operating  voltages  for 
the  amplifier  are  furnished 
by  a  home-brew  power  sup- 
ply built  in  two  mating 
chassis.  A  sketch  of  this 
unit  is  shown  in  Fig  5. 
Three  large  series-con- 
nected TV  transformers  are 
mounted  inside  the  bottom 
chassis.  The  filament 
transformer,  bias^supply 
transformer,  and  power 
control  relay  are  also 
mounted  in  this  chassis. 
The  series  rectifier  and 
filter  capacitor  board  is 
mounted  on  top  of  this 
chassis.  The  upper  chassis 
provides  a  "top"  for  the 
power  supply.  It  is  cut  and 
fitted  with  corrugated 
aluminum  for  ventilation. 
The  two  chassis  are  held 
together  by  a  front  panel 
and  a  steel  strap  screwed 
into  the  rear  of  both 
pieces  A  sheet  of  heavy 
perforated  aluminum  also 
covers  the  bottom  chassis, 
thus  serving  as  a  bottom 
cover  for  the  power  supply. 
A  "whisper  fan"  is 
mounted  above  the  power 
supply  to  provide  addi- 
tional cooling. 

Operation 

Amplifier  tune-up  is 
straightforward  and  fol- 
lows conventional  plate- 
tuning  techniques.  Re- 
member to  use  minimum  rf 
drive  when  initially  loading 
the  amplifier  to  avoid  high 
off-resonance  plate  cur- 
rent. If  you  have  any  old 
811  As,  this  initial  tune-up 
time  is  ideal  for  their  use. 
Once  the  amplifier  is  work- 
ing properly,  you  can  make 
a  chart  of  the  load  and 
plate  settings  and  output 


WEAR  PAKtL  JACK 


NUTS 


aANQSWFTCH 


TUfiiNG  '^  METER 

CAPACITOR 


ftEAFT  PAHBl 


NUTS 


3  1/2' 
SCREWS 


•—CMASSiS 


2*  SCftE«S 


fig*    2.    Top    view    of   component    layout    tn    kilo 
amplifier. 


Fig.  3,  Mounting  arrangement  for  tube  sockets  and  parts 
used  in  the  amplifier. 


228 


FlUA^EJVTS 


»WClS%Et>   PLATE   vgLtA^e    HtTER 


PMlTt 


Om   PLUTE 


ENVELOPE 


»OM,fiD 


■9'5EP?F£S 
COKINECTED 
rf?&hr5F0RMERS 


K-  FTAY   SIDE    VIEW 


■FILAMEMT 
Tfif  AM? FORMER 


ff^mi    VIEW 


Fig,  4.  End  view  of  811 A  as  seen  from  front  panel.  The 
filaments  should  be  positioned  as  shown.  The  top  of  the  il- 
lustration corresponds  to  the  top  of  the  amplifier 


Fig,  5.  Power  supply  cabinet  arrangement. 


power  level  for  each  band^ 
This  chart  will  serve  two 
purposes:  It  will  help  keep 
you  from  running  the  plate 
current  more  than  50  mA 
off  resonance  and  it  will 
help  you  realize  when  the 
finals  eventually  begin  to 
lose  output. 

Typical  operating  pa- 
rameters of  my  amplifier 
are  1 700  volts  at  800  m A  on 
20  meters,  producing  750 
Watts  output.  These  rf 
levels  are  possible  because 


grounded-grjd  annplifiers 
allow  the  driving  power  to 
directly  add  with  the  out- 
put power 


Conclusion 

As  this  article  illustrates, 
the  811A  amplifier 
is  one  of  the  most  ver- 
satile and  inexpensive 
amplifiers  that  an  amateur 
can  build  and  operate.  The 
concept  of  separating  rf 
and  power  supply  sections 
is  also  quite  appealing  to 


many  amateur  setups.  The 
ttme-proven  circuit  is  easi- 
ly adapted  to  one's  par- 
ticular station  arrange- 
ment,  thus  producing  a 
reliable  finished  product 
which  can  be  enjoyed  for 
many  years.  Recently,  I 
purchased  a  new  R.  L. 
Drake  TR-4  CW  transceiver 
and  considered  purchasing 
a  new  linear  amplifier  also. 
After  several  weeks  of 
deliberation,  I  concluded 
that  my  seven-year-old 
811 A  amplifier  couldn't  be 
beat.  I  replaced  tubes  and 
filter  capacitors,  cleaned  it 


like  new,  and  It's  now 
ready  for  another  seven 
years'  service  What  more 
could  one  ask? 

I  would  like  to  thank 
Erskine  lackson  W4CEC 
for  his  assistance  in  the 
design  and  layout  of  this 
amplifier.  Erskine's  in- 
genuity was  the  prime  con- 
tributing factor  to  the 
amplifier's  professional 
results.  Thanks  also  to 
Robert  Perkins  of  Bir- 
mingham AL  for  special 
processing  of  the  photo- 
graphs used  in  this 
article  ■ 


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229 


Ham  Radio  Goes  to  School 


W-year-olds  love  it! 


William  L.  Lazzaro  N2CF 
}!  Jefferson  Street 
Highland  Mills  NY  10930 


i  i  LJ  ey,    Mr.    Lazzaro, 

I  I  we  got  Maine!  Our 
RST  was  579,  and  the  guy 
didn't  believe  us  when  we 
told  him  we  were  only  10 
years  old," 

Teaching  fifth*grade 
youngsters  at  Montebello 
Elennentary  School  in  Suf- 
fern,  New  York,  has  been 
an  exciting  experience  for 
me  But  when  I  introduced 
my  students  to  amateur 
radio,  my  vocation  as  a 
teacher  took  on  incredibly 
exciting  dimensions. 

I  began  my  introduction 


to  amateur  radio  one  day 
without  prior  announce- 
ment. It  was  in  December, 
1975,  and  I  had  just  pur- 
chased a  new  Yaesu  FT- 
101 B.  I  obtained  permis- 
sion from  the  principal  to 
put  up  a  40  meter  dipole 
and  I  was  in  business!  As 
the  children  came  into 
school  that  day,  their  at- 
tention focused  on  the 
gray  box  in  the  corner  of 
the  room.  Ten-year-ofds 
are  curious  souls  and  they 
had  many  questions  about 
it.  Finally,  the  moment  ar- 
rived for  our  first  QSO.  I 
went  back  to  the  rig, 
grabbed  the  mic.  and 
called  my  first  CQ^  That 
CQ  has  echoed  in  the  halls 
of  Montebello  School  for 
the  last  three  years.  Little 


did  I  know  at  the  time  that 
I  was  ushering  in  a  new  era 
of  excitement  for  those  ele- 
mentary-school students. 

In  that  first  year  of 
operation  from  my  class- 
room, we  worked  17  states. 
All  my  students  received 
QSL  cards  from  gracious 
amateurs  and  everyone 
had  a  chance  to  talk  over 
the  air 

It  wasn't  long  before  my 
students  wanted  to  know 
how  they  could  become 
hams,  I  explained  the  FCC 
requirements  for  the 
Novice  license,  but  I  per- 
sonally felt  10~year-olds 
were  just  too  young  to  get 
a  license. 

Since  fifth-graders  enjoy 
secret  codes  and  ciphers,  t 
introduced  my  students  to 


Morse  code,  To  my  utter 
amazement,  all  my  stu- 
dents loved  it!  Many 
learned  it  so  well  they  could 
communicate  effectively 
in  code.  The  year  ended  in 
)une  with  sad  faces  as  my 
students  and  I  realized  our 
exciting  year  with  ham 
radio  was  ending. 

The  next  September,  1 
began  teaching  radio 
theory  and  Morse  Code 
long  before  t  brought  in  my 
rig.  Our  year  was  very  suc- 
cessful in  making  contacts, 
but  the  children  loved  the 
code  the  best!  The  profi- 
ciency exhibited  by  the  ma- 
jority  of  my  students 
amazed  all  who  witnessed 
it.  We  had  sent  Morse  code 
with  flags  from  mountain- 
top  to  mountaintop  while 


/  found  flash  cards  to  be  a  valuable  teaching  aid  for     Boys  and  girls  exhibit  equal  enthusiasm  and  prof  iciency  as 
reviewing  material  already  taught.  operators. 


230 


hiking,  and  we  sent 
messages  across  a  lake  at 
night  using  flashlights 
while  camping.  We  even 
made  some  on-the-air  CW 
contacts!  I  was  now  con- 
vinced that  the  average 
lO-year-old  could  learn  the 
code  and  use  it  proficient- 

ly. 

As  September,  1976, 
roiled  around,  my  attitudes 
toward  the  possibility  of 
10-year-olds  getting  li- 
censed were  changing 
One  of  my  first-year 
students  had  gone  to  get 
his  General  class  license! 
He  skipped  the  Novice 
license,  stating  it  was  too 
easy!  (Presently  he  is  in 
ninth  grade  and  holds  an 
Extra  class  license  with  a  1 
X  2  callsign  to  boot!) 

t  taught  my  students  the 
code  and  I  operated  por- 
table from  my  classroom 
with  the  FT-101 B.  As  spring 
came,  I  had  a  group  of  six 
students,  three  boys  and 
three  girls,  who  were  most 
proficient  at  code  and  who 
wanted  to  be  hams.  I  decid- 
ed to  see  how  much  theory 
they  could  learn.  We  began 
classes  at  noon  hour  and 
recess.  They  learned  quick- 
ly as  long  as  I  taught  them 
in  little  steps  and  on  one 
topic  at  a  time.  We  re- 
viewed constantly  what  I 
had  already  taught.  (Later  I 
was  to  find  out  that  flash 
cards  would  be  of  great 
help  in  reviewing.)  In  May, 
all  six  took  their  Novice  ex- 
ams and  passed! 

The  realization  that  I 
had  a  problem  now  be- 
came apparent.  1  had  six 
10-year-old  licensed  radio 
amateurs  on  my  hands  and 
no  gear  for  them  to  use, 
save  a  CW  QRP  rig  I  had 
built.  It  was  ludicrous  to 
think  a  fifth-grader  could 
finance  his  own  station,  so 
I  began  the  search  for  fund- 
ing for  ham  radio  equip- 
ment to  be  located  at 
school. 

My  principal  alerted  me 
to  the  possibility  of  a  dona- 
tion from  our  Parent- 
Faculty    Association,    It 


seemed  that  they  had  had 
an  unusually  successful 
year  at  fund-raising  and 
they  were  looking  for  a  gift 
to  present  to  the  school. 

I  wrote  out  a  detailed 
proposal  for  the  station 
equipment  I  needed  and  1 
planned  an  extracurricular 
program  for  a  ham  radio 
club.  I  presented  my  plan 
to  several  members  of  the 
PFA  executive  board  and  I 
received  a  chilly  response. 
I  would  have  to  convince 
the  PFA  that  my  plan  was 
worthy  of  their  support  if  I 
was  to  get  the  funding  I  re- 
quested. 

An  invitation  to  speak  at 
a  PFA  meeting  gave  me  my 
opportunity  to  "sell"  ham 
radio.  After  carefully  plan- 
ning my  presentation,  1 
gave  it  to  them  with  all  the 
enthusiasm  of  an  ardent 
amateur  radio  operator!  As 
the  meeting  ended,  I  not 
only  had  gained  the  fund- 
ing I  requested,  but  I  also 
had  many  offers  of  help! 
Even  some  of  the  mothers 
asked  if  they  could  get 
their  own  ham  licenses 
through  my  program! 

I  was  thrilled!  My  dream 
of  having  an  amateur  radio 
club  station  at  school  was 
going  to  be  a  real  ity.  Unfor- 
tunately, I  was  to  learn  that 
several  problems  would 
have  to  be  solved  before 
my  dream  came  to  fruition. 

The  first  difficulty  I  ex- 
perienced was  finding 
gear.  I  had  received 
enough  money  to  purchase 
a  low-cost  used  SSB  trans- 
ceiver. My  first  inclination 
was  to  check  the  classified 
ads  in  ham  magazines. 
There  was  nothing  listed  at 
that  time  which  was 
suitable.  Then  I  began  call- 
ing dealers,  hoping  to  find 
a  trade*in.  1  contacted 
more  than  ten  dealers  and 
none  of  them  had  a  thing. 
At  this  point  I  became 
aware  of  the  severe  scarci- 
ty of  low-cost  used  ham 
gear. 

I  wondered  if  I'd  be  able 
to  find  appropriate  equip- 
ment in  my  budgeted  price 


Brian  WB2Q0V  demonstrates  the  way  it's  done. 


range.  My  search  lead  me 
to  a  brokerage  firm.  They 
had  a  Heathkit  HW-lOO 
listed.  I  snatched  it  up  im- 
mediately and  considered 
myself  lucky. 

Setting  up  the  station 
was  relatively  easy.  I  at- 
tached 2  X  4s  about  eight 
feet  high  to  protrusions  on 
the  roof  of  the  school,  and 
I  strung  up  my  dipoles.  As  I 
ran  my  transmission  lines,  I 
wondered  about  the  line 
loss.  Each  transmission  line 
had  a  run  of  200  feet  and 
we  couldn't  afford  any- 
thing better  than  RG-58/U 
coax. 

My  concerns  were 
calmed,  however,  as  I  load- 
ed the  forty  meter  dipole 
and  worked  several  sta- 
tions with  good  reports. 

It  was  difficult  to  con- 
tain my  excitement  any 
longer.  Although  it  was  on* 
ly  August,  I  called  together 


my  vacationing  Novices 
for  a  club  station  christen- 
ing. 

We  met  together  after 
nearly  two  months  without 
any  CW  practice.  As  we 
sent  our  first  CQ  with  the 
club  station,  six  nervous 
Novices,  armed  with  pen- 
cils and  paper,  crowded 
around  the  HW-100  anx- 
iously waiting  for  a  con- 
tact. 

Suddenly  we  heard  the 
sweetest  sound  any  ham 
can  hear!  Our  callsign  was 
being  sent  to  us  in  pure  dc 
notes.  It  was  music  to  our 
ears! 

The  excitement  of  that 
moment  quickly  turned  in- 
to a  mild  panic  as  rusty 
minds  struggled  to  copy 
the  callsign  being  sent  to 
us,  "I  didn't  get  thatr 
''He's  sending  too  fast/' 
"What's  ■  —  ■■r'  'M  can't 
remember/'    These    words 


Severat  YLs  log  another  QSO  made  from  our  dub  station, 
WB2RZP, 


231 


filled  the  station  as  ner- 
vous hands  wrote  the  mes- 
sage being  sent  to  us. 

Once  it  was  our  turn  to 
transmit,  another  problem 
developed  "What  should  I 
say,  Mr  Lazzaro?''  was  the 
question  asked  of  me.  As  I 
hurriedly  wrote  out  a  mes- 
sage format,  I  began  to 
reahze  that  I  still  had  a  lot 
to  teach  these  newcomers. 
CW  abbreviations  and 
operating  format  were  not 
required  material  to  get  a 
license,  yet  they  were 
essential  to  know;  I  had  to 
teach  these  Novices  this 
material  and  fast- 
Later  I  prepared  a  wall 
chart  of  a  typical  QSO  and 
another  with  common  CW 
abbreviations.  We  worked 
together  to  learn  both, 
Once  this  was  accom- 
plished, I  thought  my  prob- 
lems were  solved.  Not  so! 
For  some  time,  my 
students  made  hit-or-miss 
contacts.  Sometimes  they 
achieved  complete  QSOs 


and  other  times  they  only 
received  the  callsign  of  the 
other  station.  Then  the 
percentage  of  incomplete 
contacts  or  no  contacts 
began  to  outstrip  com- 
pleted QSOs.  The  log 
showed  remarks  like  ''tost 
transmission''  and  'QRM.'' 
I  decided  to  go  on  the  air 
myself  and  see  if  the  rig 
was  working  properly.  I 
made  a  contact  imme- 
diately and  had  a  complete 
QSO  without  any  difficul- 
ty. I  was  sure  the  rig 
worked. 

That  week  I  made  ar- 
rangements to  actually  be 
in  the  ham  shack  while  the 
Novices  went  on  the  air. 
After  only  a  few  minutes,  I 
realized  the  problem.  They 
were  sending  CQ  at  about 
thirteen  words  per  minute. 
When  a  station  answered 
them  at  that  speed,  no  one 
could  receive  it,  since  their 
code  speed  was  still  well 
below  thirteen  wpm. 

We  set  up  a  verbal  rule 


stating:  "Send  only  as  fast 
as  you  can  receive/'  That 
corrected  our  problem. 

The  logbook  began  fill- 
ing up  with  completed 
QSOs.  We  even  began  col- 
lecting QSL  cards  at  a  high 
rate  of  speed. 

After  school  Novice 
classes  commenced  in  Oc- 
tober of  1977.  By  February, 
1978,  we  had  ten  more 
Novices,  with  more  on  the 
way. 

Today  the  Novices  are 
operating  at  lunch  and 
recess  for  one  hour  a  day. 
Those  who  have  taken  their 
exams  and  are  waiting  for 
the  results  act  as  third  par- 
ties when  the  Novices 
operate.  These  future  hams 
are  getting  actual  orhthe- 
air  experience  while  learn- 
ing what  they  will  need  to 
know  as  operators. 

My  program  has  arrived 
at  almost  a  self-perpetuat- 
ing  point.  There  are 
children  at  all  levels,  with 
those  children  at  the  higher 


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The  excitement  gen- 
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Students  are  signing  up  for 
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shows.  At  recess,  children 
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ing games. 

It  should  be  noted  that 
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made  it  a  point  to  en- 
courage both  sexes  equal- 
ly. It  has  paid  off! 

Montebello  School 
hasn't  been  the  same  since 
that  first  CQ  in  1975.  We 
are  now  looking  ahead  to 
upgrading  and  the  joys  of 
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233 


Jim  Garrett  K5BTV 
619  Cimmaton 

Lewisvitfe  TX  7S067 


What's  Your  uF? 


a  six-digit  answer 


The  following  project 
VieJds  a  simple  but  ac- 
curate digital  meter  to 
measure  capacitance  val- 
ues from  1  pF  to  999999  pF 
(1.0  uF]. 

Theory  of  Operatian 

The  theory  of  operation 
is  based  on  the  equation 
I  =  C(dv/dt).  Rearranging 
the  equation,  C  =  l[dtidv), 
where  C  is  pF,  I  is 
microamperes,  dt  is  in- 
crements of  one  ^s,  and  dv 
is  change  of  voltage  in 
volts  across  the  capacitor. 

In  other  words,  if  a 
counter  chip  were  to  count 
the  time  it  took  a  given 
capacitance  to  charge 
from  a  constant  current 
source  to  some  fixed 
voltage  level,  that  count 
would  be  equivalent  to  the 
capacity  being  measured. 
A  block  diagram  in  Fig.  1 
further  describes  the 
operation. 

The  start-measurement 
switch  drains  the  charge 
from  the  capacitor  under 
measurement  and  diverts 
the    constant    current 


WF 


source  to  ground.  Also,  the 
1  MHz  pulses  are  not 
allowed  to  accumulate  in 
the  counter. 

Upon  activating  the 
start-measurement  switch, 
the  capacitor  begins  charg- 
ing. The  counter  is  ac- 
cumulating the  one  micro- 
second pulses,  and  the 
race  is  on.  The  capacitor 
charge  voltage,  upon 
reaching  the  threshold  of 
the  count-inhibit  line  of 
the  counter,  prevents  the 
counter  from  accepting 
any  ryiore  1  MHz  pulses. 
Therefore,  the  contents  of 
the  counter  can  be 
displayed  directly  as  the 
value  of  the  capacitance 
being  measured. 

Returning  to  the  equa- 
tion one  last  |jme  and 
assuming  an  example,  ex- 
amine what  capacitance  is 
represented  in  the  follow- 
ing (where  I  =  5  micro- 
amperes ~  5  X  10~^  Amp: 
dt  =  47  microseconds  — 
47k  10^6  sec;  and  dv  =  5 
volts): 

CpF  =  [(5x10-6) 
(47  X  10-6)1/5 


COUNT 

INHifliT 


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I^STAUT^  Ut  ft  5U  W€  M  J  NT J 


fig.    1. 


=  (235  X  10-121/5  pF 

^  47  pF 

So  far,  theory  shows  the 
approach  to  be  a  workable 
idea.  To  reduce  this  theory 
to  actual  practice,  the  use 

of  the  schematic  shown  in 
Fig.  2  resulted  in  being  able 
to  measure  capacitance  to 
within  ±5%,  or  ±1  pF, 
whichever  is  greater,  from 
1  pF  to  999999  pF  (1.0 
microfarad).  Now  those 
unmarked  capaeitors  can 
be  accurately  npeasured 
and  their  value?  displayed 
digitally.  ,   ' 

The  Schematic 

The  key  to  the  simplicity 
of  the  capacitance  meter  is 
the  MK50395N  six-decade 
counter  manufactured  by 
Mostek.  This  counter  per- 
forms the  tasks  of  counting 
up  or  down,  is  presettable, 
has  a  compare  register  that 
provides  an  equal  output 
when  the  counter  contents 
equal  the  register  contents, 
and  also  provides  seven- 
segment  and  BCD  output 
data.  The  list  of  features 
continues,  but  those  in- 
terested can  get  the  data 
sheet  by  writing  Mostek, 
Box  169,  Carrollton  TX 
75006. 

The  1  MHz  oscillator  is 
arranged  using  U1,  CMOS 
NAND  gates,  and  is  a  Stan* 
dard  design.  Since  extreme 
accuracy  was  not  a  require- 
ment,  no  frequency  trim- 


ming or  special  crystal 
tolerance  is  specified.  This 
should  simplify  and  lessen 
the  expense  of  the  com- 
ponents. U2  provides  the 
control  functions  neces- 
sary to  operate  the  meter. 

Linear  amplifier  A1  is  a 
dual  bi-fet  high  input  im- 
pedance amplifier.  A1  is 
wired  to  drive  a  constant 
current  (adjustable  by  R4) 
through  the  capacitor  be- 
ing measured.  Amplifier  A2 
is  used  as  a  comparator  so 
that,  when  the  output  of  A1 
reaches  a  predetermined 
voltage,  A2  switches  its 
output  from  zero  volts  to 
V+-.  This  action  prevents 
further  counts  from  accu- 
mulating in  the  MK50395 
counter.  The  diodes  from 
digit  strobe  lines  on  the 
counter  feed  preset 
counter  BCD  inputs  A  and 
D.  This  results  in  digit  6 
down  to  digit  3  having  a  9 
preset  into  it.  Digit  2  is 
loaded  with  an  8,  and  digit 
1  (LSD)  is  loaded  with  zero. 
The  BCD  inputs  have  inter- 
nal pull-down  resistors,  so 
a  zero  will  be  loaded  into 
the  unconnected  BCD  in- 
put ports.  More  on  this  in 
the  calibration  sequence. 

A  single-pole  three- 
position  break-befo  re- 
make switch  is  used  to  pro- 
vide the  control  sequence 
for  the  unit.  On  the 
schematic,  position  A  is  the 


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Fig.  2.  Note:  Capacitors  are  silver  mica  un/ess  otherwise  specified.  Resistor  values  are  70%,  !^  Watt  urrless  otherwise 
specified. 


starting  point.  While  in 
position  A,  the  counter  is 
being  loaded  with  99980. 

Position  B  stores  the 
data  in  the  counter  dispiay 
after  a  capacitor  measure- 
ment. 

Position  C  initiates  a 
measurennent. 

Upon  returning  to  posi- 
tion A,  the  value  of  the 
capacitor  nneasured  will  be 
stored  for  display  and  the 
counter  preset  for  the  next 
measurement. 

The  unit  utilizes  leading 
zero  suppression,  so,  when 
the  counter  contains  all 
zeros,  the  display  will  show 
only  one  zero  when  turned 
on. 

Calibration 

Calibration  is  ac- 
complished in  two  steps: 
high  value  and  stray.  1 ,000 
pF  5%  silver  mica  or  other 


high-value  close-tolerance 
units  may  be  used  for  the 
initial  setting.  Since  most 
capacitors  are  ±20% 
tolerance  units,  extreme 
accuracy  is  not  a  require- 
ment, and  the  silver  mica 
units  will  provide  suffi* 
cient  accuracy  if  closer 
tolerance  units  are  not 
available,  1,000  pF  to 
10,000  pF  values  are  pre- 
ferred for  calibration. 

Attach  the  known-value 
capacitor  to  the  input  ter- 
minals. Apply  power,  and 
switch  from  A  to  C  with 
SW1.  The  display  will  read 
some  value.  Adjust  R43  un- 
til 1,000  pF  ±  15  pF  is 
shown.  This  completes 
step  one. 

The  next  calibration  se- 
quence will  zero  out  the 
stray  capacity.  Adjust  trim- 
mer  capacitor  CI  for 
minimum    capacity.    With 


no  capacitor  connected  to 
the  unit,  switch  from  A  to 
C.  Some  number  will  show 
on  the  display  (999992  on 
test  unit).  This  represents 
the  preset  number  loaded 
into  the  counter  plus  the 
stray  capacity.  This  value 
must  be  zeroed  out,  so 
small  capacitor  values  can 
be  measured.  Zeroing  the 
stray  is  accomplished  by 
adjusting  the  trimmer  CI 
until  the  meter  reads  zero 
when  switching  from  A  to 

C. 

Upon  completion  of 
zeroing  out  the  stray  value, 
return  to  the  1,000  pF 
capacitor  and  readjust  if 
necessary  to  bring  the  unit 
into  calibration. 

General 

A  digital  display  can  pro- 
duce some  distracting 
observations.  As  an  exam- 


ple, measuring  a  5,000  pF 
(.005  uF)  capacitor  may 
produce  a  reading  of  5040 
pF  one  time  and  4995  the 
next  time.  Remember,  even 
though  that  appears  to  be  a 
large  value,  it  represents  a 
±0.9%  accuracy.  Since 
the  majority  of  capacitors 
are  ±20%,  this  unit  allows 
measurement  of  those  un- 
marked capacitors  suffi- 
ciently accurate  for  most 
applications. 

Two  last  comments  con- 
cern the  constant  current 
source.  The  accuracy  of 
this  type  of  capacity  meter 
depends  on  the  constant 
current  source.  Improve- 
ment in  this  area  will  im- 
prove overall  perfor- 
mance. Secondly,  any 
capacitor  that  is  'leaky" 
Will  give  a  readiiig  that  is 
not  representative  of  its 
true  value.H 


235 


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YD-044 
Dynamic  Mike 


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2M  MOBILE  TRANSCEIVEft.  Svnthesfed  PLL. 
Selectab^  output.  25  watu  or  10  watts.  C  0^i( 
LED  fieq.  dT^iay.  144  148  MH?.  800  CH.  m  & 
KHz  steps.  600  KHi  repeater  otfict.  Contmuaui 
tone- coded  sqyelcN  (CISC).  Tone  BuFSt. 


TS8Z€S 


$124100 


SSB  TRANSCEIVER.  PLL  RF  Monitor  Noise 
Blanker.  Di^aal  hold  locks  counter  &  display  ai 
•nv  ttequencv,  but  allOMf  VFO  to  tunenormailv. 
True  RF  tofnpressor  adjustable  sp^ch  proces^r. 
IF  shift  conirol.  RF  atienuafof.  VOX,  CAIN, 
AfiirVOX  and  VOX  delay  contmls,  RF  m^tm 
feedback,  Opdooil  digjtal  readoift.  ORS  Dial.  High 
ttabilrlv  FET  VFO. 


TS-S20S 


S799.0I] 


SSe  TRANSCEIVER.  Proven  m  the  shades  of 
thousands  of  discriininatmg  hams,  field  day  Sftes, 
OX  and  cofitest  stations  and  mobile  installation's. 
Superb  eogineerifig  aod  styling. 


SP-5Zfl  $33.00 

Optjonil  e^cternal  i{ieaker  for  better  leadability. 

TVSOZS  S29I.00 

TBANSVERTER.  Puts  you  on  2M  the  easy  way. 
I44'14&J  MHz  or  optiofial  145-146  MHz. 


^™         -INIROOUCING-    ^^33°° 

THE  UiTUIATF  tR  RtCllVitt  OESlfia.  „THE  KEIMOOll  »«» 
With  due  t^lMlH  Uufl  ftV  triinv  mttriMi  m  t  i«n-|uMitf  rtfipi*.  T^ 

«i   Ai^BW    tedil  *tVM   liD  ttoDHfHi   n  MUnil^  M  MH  it 

ti^wis,  iMUfeUiiv  imn  tpmum%  otnimmmm  ikn  iP<r  all 

The  fl-m  iMf  ta  «Hd  ift  miJBKliBii  wlh  ih<  K,i 


TS-aSS  HTBtniKihv.  prdwidini  rutt  ir;wtqc«3ii  frt4<iiic¥  mnati 


^ 

^ 


S 


MCSO 


S4aoo 


Dynamic  microphone  designed  expressly  for  ama- 
teur radto  opeiation.  Compleie  with  PTT  and 
LOCK  flitch es,  md  a  mtcrophone  pSug.  1600  or 
50k  ohm} 


COMMUNlCATJOliS  RECEIVER.  1.S  to  29J 
MH2,  WWV  and  CO  bind.  50  MHz.  144  MH^  con- 
verier  optional.  Stable  VFO  &  oicHtator  for  S 
frxed  diatiaeEs.  1  KH^  dial  readout,  Xial  fillers 
jSSS'S  pole.  CW/B  pole,  AM/6  pole}.  Squelch. 
S  meter.  Noise  blanker. 


3^5990  SZLOO  R  B99D  S499.0D  T  5990  $49900 

SSe  TRANSMITTER.  3.5  to  29.7  MHr.  Stable 
VFO.  1  KHz  dial  feadout.  B  pole  Xtal  filter.  AM 
Xmision  aval  table.  Butft-in  AC  pwr  supply.  Split 
trequency  control  available. 


SS 


VFQB20 


SI  75. 00 


Designed  eKcluBively  for  urn  with  TS'82fl.  BIT 
Circuit  md  control  switch,  FuHy  compatible  with 
optional  digital  display^ 

VFOS20  (Not  Shown)  S143.00 

Solid  State  Remote  VFO,  RIT  circuit  with  LED 
if^dicator. 


SM^22Q 


S149.00 


R300 


S279.0Q 


KENWDOD'S  SM-22Q  STATION  MONITOR.  The 
SMZZO'i  unexcelled  vwsatility  atloiws  you  to 
moi^itor  your  transmmions,  monttnr  incomiog 
sifnals,  and  nwnitor  the  aniount  and  strength  of 
band  airtivity*  and  performs  as  a  genera Ipyrpose 
to  MHz  osciltoscope,  as  well. 


ALL  BAND  COMMUNICATIONS  RECEFVER. 
AC,  batteries  or  exiernal  DC.  170  KHi  to  30  MHi 
in  6  bar\ds.  Foreign  broadcasts  or  ham  tidio  in 
AM,  SSB  and  CW.  Dual  gate  MDS/FET  transistors 
&  double  conwereon.  &and  spread  diaL  &0G  KHz 
marker. 


CALL  JIM  TITUS  FOR  FREE  QUOTES  ON  TOLL  FREE  NO.  800-523-8998 


k 


y 


DIVISION  OF  TREVOSE  ELECTRONICS 

4033  Brownsville  Rd  •  Trevose,  Pa.  19047 


IW^uTSWMSiMMSmM^MXTm 


DRAKE 


® 


KNOWN  FOR  QUALITY 
THROUGHOUT  THE  WORLD 


RECEIVERS 

DSR'2 
4NB 


VLF'HF  Digitat  Synthesized  SSB, 
AM,CWJSB,RTTY 
C'Une.  HF.160  10M 
Noise  Blanker  for  R  4C 


TRANSMITTER 


T4XC 


C-Line.HFjeO  10M 


TRANSCEIVERS 


LINEAR  AMPLIFIER 


L4B 


Linear  and  w/power  supply  &  tubes 


MATCHING  NETWORKS 


$3200.00 
$699.00 

$74.00 


$699.00 


TR-7 

Transceiver 

$1100,00 

DR7 

Digital  Readout 

$195.00 

RV7 

Remote  VFO  for  TR7 

$195.00 

FA-7 

Fan  for  TR-7 

S25.00 

MS7 

Speaker  tor  TR-7 

$33.00 

7077 

Dynamic  Desk  Mike  for 

TR7 

$45.00 

34PNB 

Plug-in  Noise  Blanker  forTR-4  Series 

$100.00 

$995;00 


MN4C 

Antenna  Matchlitfl  Network.  200W 

$165.00 

MN'2000 

Antenna  Matching  Network.  1000W 

$a50.00 

W-4 

RF  Wattmeter,  1J  to  54  MHz 

$79.00 

WV'4 

RF  Wattmeter,  20 to  200  MHz 

$89.00 

7073 

Hand-Held  Microphone 

$19.00 

7075 

Etesk  Top  Microphone 

$45.00 

1525EM 

Push-button  Encoding  Microphone 

$49.95 

HS1 

Head  Phones 

$10.00 

AA10 

low,  2M  Amplifier 

S49,95 

TV300HP 

300 ohm  High  Pass  TV  Set  Filter 

$10.60 

TV75-HP 

75  ohm  High  Pass  TV  Set  Filter 

$13.25 

TV42-LP 

Transmitter  Low  Pass  Filter.  100W 

$14.60 

TV  3300- LP 

Transmitter  Low  Pass  Filter.  1000W 

$26.60 

TV  5200- LP 

Transmitter  Low  Pass  Filter  1000W. 

100W,6M 

$26.60 

USED  GEAR  •  TRADE  UP  •  FREE  UPS  SHIPPING  ON  PREPAID  ORDERS 


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COLLINS  AMATEUR  EQUIPMENT 


^M' '  "-^^i^  ^J^ '  ■^''  ™  '^-'w  V. . ,[. ..    •  1  ','■■'  .w  V  !■!'  .■  '  -*■"  ■  'JJmi^^.'.'  jiA*^  '"'.'^.'i^'y^'  ^ 


KWM  ZA  TRANSCEIVER  $353300 

Unmatched  for  mobile  and  fixed  station  applications.  175W 
on  SSB,  160W  on  CW.  Switch  select  up  to  14  optional  Xtals. 
Can  be  used  for  RTTY.  Filter  type  SSB  generation.  Automatic 
load  control.  Inverse  RF  feedback.  Reimeability-tuned  vari^le 
oscillator. 


75S-3C  RECEIVER  $3000.00 

Sharp  selectivity.  SSB,  CW  and  RTTY.  Single  control  rejection 
tuning.  Variable  BFO.  Optional  mechanical  filters  for  CW, 
RTTY  and  AM.  2.1  KHz  mechanical  filter.  Zener  regulated 
oscillators.  3-position  AGO. 


,^^^JLk^X^.h>^f:l>^dAw.v-^>x.^l^ — .^_%> -^4/.- . .    J^^^^^-v^.  J  I,      ll"    ""yllV   y^t^t^i^ 


32S-3A  TRANSMITTER 


$3250.00 


Covers  all  ham  bands  between  3.4  MHz  and  30  MHz.  Nominal  output  of  100  W.  175  W,  SSB  and  160  W 
CW.  Dual  conversion.  Automatic  load  control.  RF  inverse  feedback.  CW  spotting  control.  Collins 
mectianical  filter. 


319B-3  SPEAKER 

$95.00 


W  312B-4 

SPEAKER  CONSOLE 

$648.00 


313B-5  VFO  CONSOLE 

$1616.00 


o 


VI 


516F-S  AC  POWER  SUPPLY 
$440.00 


302C-3  DfRECTIONAL  WATT  METER 

$493.00 


DL-1  DUMMY  LOAD 
$370.00 


CALL  JIM  TITUS  FOR  FREE  QUOTES  ON  TOLL  FREE  IMO.  800-523-8998 


i 


id 


DIVISION  OF  TREVOSE  ELECTRONICS 

4033  Brownsville  Rd  •  Trevose,  Pa,  19047 


/OH  C\ 


A  Mf\i\  ii*\'%  C\ 


conn 


I 


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M 


mRB  THRULINE®  WATTMETER 


•  BUY  ONLY  THE  ELEMENTS  YOU  NEED 
AND  ADD  EXTRA  RANGES  AT  ANY  TIME 

•  READ  RF  WATTS  DIRECTLY 


Table  1 

STANDARD 
ELEMENTS 


MODEL  43 


FrrquervcY  Bands 

1MH£) 

r&^tr 

Rjn|r 

1- 

25- 

50- 

lOO- 

200- 

400> 

W 

M 

125 

250 

soo 

TOOO 

S  watts 

J 

5A 

5B 

sc 

5D 

5£ 

1Q  watts 

— 

IDA 

lOB 

IOC 

1DD 

10E 

25  watts 

2SA 

25B 

25C 

2SD 

2SE 

SOwait^ 

50H 

50A 

SOB 

50C 

50D 

50E 

100  wait* 

100H 

100A 

100B 

100C 

tOOD 

lOOE 

2S0watt^ 

250H 

250A 

250B 

2S0C 

2500 

250E 

SOOwdtts 

500H 

500A 

MOS 

5Q0C 

500O 

sooe 

TOiO  watts 

lOOOH 

lOOOA 

10006 

1000C 

10000 

toooc 

2500  watts 

2S00H 

5000  watts 

SOOOH 

Table  2 
low- 

POWER 
ELEMENTS 


1W4lt 

tjt.  No. 

TS  watts 

Cat,  No. 

fX^m   hAHi 

060-1 

60-80    MHz 

060-2 

80-95    MHj 

OQO-1 

flO-95    MH7 

080^2 

9S-125  MHi 

095-1 

95-150  MHz 

095-2 

nO-160MHr 

110-1 

150-250  MHj 

150-2 

150-250  MHt 

1S0-1 

TOO-JOOMHi 

200-2 

200^300  MHz 

200-1 

25fr450  MHz 

250-2 

275*450  MHz 

275-1 

400-850  MHi 

400^2 

435-650  MHz 

425-1 

BCX)-950  MHl 

800^2 

800-950  MHz 

aoo-T 

WE  HAVE  A  COMPLETE  STOCK  OF  ALL  BIRD  WATTMETERS  AND  SLUGS 


I 


ATLAS 


21  OX 


21 5X 


220CS 


350-XL 


Transceiver.   10-80M. 

200W 

Transceiver.  15-160M. 

200W 

Deluxe  Mtg.  Kit  for  210X 

&215X 

AC  Console  for  21  OX  & 

21 5X 

Transceiver.  SSB.  Solid 

State. 

10-1 60M.  350W. 


765.00 


765.00 


55.00 


155.00 


1195.00 


DD6XL 


305 


311 


350-PS 


DMKXL 


Digital  Dial  Readout  for 

350-XL 

Plug-In   Auxiliary   VFO. 

For  350-XL 

Plug-In  Auxiliary  Crystal 

Oscillator  for  350XL 

AC  Pwr  Supply  w/Spi(r  & 

Phone  Jack  for  350-XL 

Mobile  Mounting 

Bracket  for  350-XL.  Easy 

Piug-ln 


229.00 


1 55.00 


135.00 


229.00 


65.00 


USED  GEAR  •  TRADE  UP  •  FREE  UPS  SHIPPIMG  ON  PREPAID  ORDERS 


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NYE  VIKfNG 


No.  114-310-003     $9.65         No.  114-310-004GP    $50.00       No.  114-404-002    $20.7S 


No.  SSK-1     $23.95 


No.  250-46-1     $36.50 


No.  250-46-3    $46.50 


No.  250-20-1     $19.95 


No.  MB2-1    $315 


NPC 


2.5  AMP 


4  AMP 


6  AMP 


f  y  ■■ 


po 


1^ 


^^.i*^^**^*^^ 


»*#^ 


J**** 


-.^^ 


*»ov*rei»  ^up^i»t»r 


iim«»i%AT«jni 


js$y4S-a.tra**JiKHii 


12CB4  29.95 


103R  39.95 


104R  43.95 


12  AMP 

108  RM 
$104.95 


25  AlVIP 


109R  159.95 


o 

X 


V* 


VIBROPLEX 


H 


"PRESENTATION" 
72.50 


ORIGINAL" 
49.95 


n 


LIGHTNING  BUG" 
49.95 


"CHAMPION" 
46.50 


VIBRO-KEYER 
46.50 


CALL  JIM  TITlJS  FOR  FREE  QUOTES  ON  TOLL  FREE  NO.  800-523-8998 


i 


y 


DIVISION  OF  TREVOSE  ELECTRONICS 

4033  Brownsville  Rd  •  Trevose,  Pa.  19047 


/#i-i 


t%e^   '«jiAA//i-«c\    ^c^   cf^nfs 


I 


"DenEm-  The  MT-3000A 


SPECIFICATIONS: 

•Power  handling  capabHIly  In  excess 
of  3  KW  PEP 

•Front  Panel  Antenna  Switch  with  5 
Antenna  Inputs  ptus  Tuner  bypass  posi- 
tion 

*Bjill-in  50  Ohm— 250  Watt  dummy  load 

•Dual  Wattmeters 

•Compact:  5%"  x  14"  x  14'\  18  pounds 

•Continuous  Tuning  160-10  meters 

♦3  Core  Heavy-Duty  Balun 


M9*S0 


.  .^.•^-iiffifi^^!^- 


Denlfon- 

Super 

Tuner 


160-10  Meters 
Balanced  Line, 
Coax,  Random 
or  Long  Wire 
Maximum  Power  Transfer,  Xmitter  to  Antenna. 

T  KW  Model  $1 29.50        3  KW  Model  $229.50 


If  they  copy  the  quaUtyt  they 
eanH  meet  the  price. 

The  original  DfinTron  Super  Tuner.  The 
original  Super  Tun-er.  The  original  MT- 
30O0A.  And  nov,'  DenTron  brings  you  the 
original  MT-2000Af  an  economical,  fufl- 
pow^r  tunei"  designed  to  handle  virtually 
any  type  of  antenna. 

The  sleek  styling  and  low  profile  of  the 
MT  2000A  is  beautiful,  but  be  assured  ttiat 
Is  only  a  part  of  the  excitement  you'll 
derive  from  the  MT-2000A,  The  MT.2000A 
is  designed  and  engineered  using  heavy- 
duty  all-metal  cabinetry,  and  high  quality 
American  components  throughout. 

When  you  consider  the  MT  2000A^s  unique  features:  5  V/"Hx  14"D?(  14"W,  front 
panel  coax  bypass  swHching,  fror\t  panel  lightning  protection  antenna  ground- 
ing switch,  3KW  PEP,  and  the  ability  to  match  coax,  random  wire  and  balanced 
feedline^  we're  sure  you'll  decide  to  buy  an  American  original  and  stay  with  Den- 

MT-ZOOOA  $199.50 


Denfforu 


The  evolution  of 
the  MLA 


When  the  MLJ^-2&00  was  first  Introduced  it  was  a  new  concept  In  high  perfor- 
mance amplifiers.  Low  and  sleek  yet  powerful  enough  for  the  military.  Some 
wondered  , . ,  needlessly. 


A  promise  kept. 


The  M1_A-Z500  promised  20O0  watts  PEP  Input  on  SSB.  A  heavy  duty  power 
supply.  Two  Etmac  8875' s.  And  as  thousands  of  Amateurs  across  the  world  have 
proven ^  the  MLA-2500  delivers E 

Now  DenTron  is  pleased  to  bring  you  The  new  MLA-25CM1B^  Inherently  the 
same  as  the  original  MLA'250Qr  the  B  model  includes  all  of  the  above  specif ica- 
t  Ions  plus  a  few  refinements.  New  high-low  power  switching  tor  consistent  effi- 
ciency at  both  the  IKW  and  2KW  power  levels,  and  160-15  meters. 


Tested  and  proven. 


What  better  test  for  ah  amplifier  than  the  Ctlpperton  DXpedltlon?  Even  after 
32,000  OSO's,  and  an  accidental  dun K  In  the  ocean,  the  same  3  MLA-2500's  are 
still  amplifying  other  rare  DXpeditions  around  the  world— listen  for  them. 

Convinced?  Isn't  It  tlmeyou  owned  the  ampilller  that  powered  Cltpperton  and 
thousands  upon  thousands  of  radio  stations  throughout  the  world? 


MLA-2500B  $899.50 


Denffon^ 


Big  Dummy 
w/eoolant 


$29.50 


All  Band 
Doublet 


Ttiii  All  Band  Doubltt  or  mvartHd  Typff 
A(M*niii  OQttti  160  fhru  tO  meXtn,  Hn 
tatal  itrigih  4rl  130  ftm  114  qa.  ittm-\dt6 
copFHrh  iifhaud^l  ^^  "W  be  (nidc  ih^rttr 
if  rHciiFtrv  Thit  tuntd  Pfjutlit  ■*  aniil- 
IhI  throu^  IW  liit  ckf  4W  ohm  PVC 
cavtrad  belaficed  Irantmiiiion  llna.  Tht 
Aaiembly  ii  comjilttt.  Add  r^pa  ia  ih« 
fln<fi  «Ki  py(l  MP  into  pfliitian,  Turt* 
Mih  ih.  D4^TrQ«i  SutMT  Tun.r  «id 
you'r*  OA  10  thrQu^hi  1^  n»tifT  wktti 
Ddv  Antannsl  Kdw  juit  lor  the  DvnTron 
All  Band  Ooubiet. 


524 '50 


JR.  MONITOR™ 
Antenna  Tuner 


Continuous  tuning  from 
1.8-30  MHz.  3O0  watt  power 
capability.  Forward  reading 
relative  output  power  meter 
— simply  tune  JR.  MONh 
TORTw  controls  for  max- 
imum RF  output  on  the 
meter.  Built-in  ba!un.  Mobile 
mounting  bracket,  Ceramic 
rotary  12-posEtlon  switch. 
Cap  acltor  spacing  1000  volts. 
Tapped  toroid  inductor. 
Antenna  inputs:  coax  un- 
balanced SO  239,  random 
wire*  balanced  feed  line 
75-660  ohm.  Weight:  2Vi 
pounds. 


S  79.50 


'DerHfon.  W-2  PAD 

INLINE  WATTMASTER 

Kead  forward 
and  reflected 

watts  at  the 
same  time 


^■■■■i--i.  . 


Tired  of  consunt  switching  and  guasiwork? 

Every  serious  ham  knows  he  musT  read  tK>th  lofw^rtf  and  ravtsne  watxagp  umuttansaui^v 
for  diat  p«rffi^t  match.  So  upgrade  with  the  DenTrqri  W-2  Dual  in  I in«  Wattmst«f , 


599.50 


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USED  GEAR  •  TRADE  UP  •  FREE  UPS  SHIPPING  ON  PREPAID  ORDERS 


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HSIF 


INC- 


TRITON  IV 
EQUIPMENT 


MODEL  940  Si  10.00 

ONE  •  SIXTY  CONVERTER 


MODEL  S49  SI 79.00 

REMOTE  VFO 


TRANSCEIVERS 


MODEL  540-SOOW,  SSB/CW 
3.5  -  30  MHi  $699.00 

MODEL  544-  DIGITAL,  SOOW 
SSR/CW,  3.S  •  30  MHz 

$869.00 


MODEL  344  $197.00 

DIGITAL  READ  OUT/COUNTER 


MODEL  262-M  $145.00 

DELUXE  POWER  SUPPLY 


ARGONAUT 


MODEL  S09  $369.00 

SW,  SSB/CW,  3.5 -30  MHx 


AMMETER 
307         $14.00 


XTAL  CALIBRATOR 

206-A    $29.00 


LINEAR  AMPLIFIER 

MODEL  405  $159.00 
100W,  3.5-30  MHz 


KEYERS 


ELEaRONIC  KR-50 

$110.00 


ELECTRONIC 
KR30-A 


S69.50 


8 


ELEaRONIC    KR-5A 

$39.50 


KR-2A 


817.00 


KM -A 


$35.00 


CALL  JIM  TITUS  FOR  FREE  QUOTES  ON  TOLL  FREE  NO.  800-523-8998 


y 


DIVISION  OF  TREVOSE  ELECTRONICS 

4033  Brownsville  Rd  •  Trevose,  Pa.  19047 


I 


I 


ICOM 


VHF/UHF  AMATEUR 
&  MARINE  EQUIPMENT 


VHF/UHF  AMATEUR 

8(IVIAR(I\IE  EQUIPMENT 

10245,  SSB  146  IVIH^  FM  10W  x 
CVR.  LSI  synthesizer  with  4  digit 
LEO  readout.  Xmii  &  Rev  frequencies 
independently  programmable.  60  dB 
spur  to  us  attenuation*     **- ji  f-  a  a 

$545.00 
1C245SSB.  $689.95 


IC215.  2  METER  FM  PORTABLE, 
Three  narrow  fillers  for  superb  perform- 
ance. 3W  or  400  mW.  15  CH.  capacity, 
MOS  FET  RF  Amp  &  5  luned  ckts, 
S-Tneier  front  panel 


$265.00 


$239.00 


IC-5Q2.  6  METER  SSB  h  CW  PORTA- 
BLE XCVR.  Includes anlenna&  battery 
pack.  3W  PEP  &  stabie  VFO  for  tun  & 
FB  QSO's.  Cr>weft  first  800  KHz  of  6M 
band,  where  nrost  acliuity  is. 


$1650.00 


\C-2U 


IC-21K  4  MEG,  MULTI-MODE  2M 
XCVR.  144-145  MHz  an  SSB  &  CW, 
plu?  148^147  MHz  on  FM.  Work  AMAT 
OSCAR  SIX  or  seven,  LSI  synthesizer 
wah  1  digit  LEO,  MOS  FET  RF  Amp, 
5  helical  cavities,  FET  mixer  S  3  LF, 


filters. 


$850.00 


IC701  W/POWER  SUPPLY  &  MIKE  •  Dual  Independent  UFO's  Built-in  •  100 
Watts  Output  •  All  HF  Bands,  IBO-IOM  •  Fully  Synthesized  Tuning  • 
Continuously  Variable  Bandwidth  •  Double  Balanced  Schottky  Diode  1st  Mixers 
RF  Speech  Processor  •  VOX;  Fastbreak  in  CW;  RIT;  AGC;  Noise  Blanker;  Full 
Metering  • 


IC280 


%ttt--** 


$480.00 


IC-21A.  146  MHz  FM  TOW  XCVR.  MOS 

FET  RF  Arrrp  h  5  helical  resonator 
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NEVER  SAY  DIE 

ec/ztor/aA  t>y  Wayne  Green 


from  page  113 

these  days,  having  proven  his 
theories  rather  spectacularly. 
Spots  mean  better  DX,  so  the 
DX  brethren  are  up  to  here  in 
countries.  They  can't  stop  wor- 
rying about  WARC  and  the 
coming  1979  ITU  plenipoten- 
tiary  conference  which  has  the 
power  to  completely  delete  alJ 
amateur  frequency  allocations. 

Where  we  actually  stand  as 
far  as  gaining,  holding,  or  los- 
ing frequencies  goes  is  more  of 
a  matter  of  belief  than  one  of 
certainty,  since  no  one  can 
know  for  sure  which  way  the 
critical  African  44-vote  black 
b)oc  will  go.  That's  the  bunch 
which  wiped  out  our  237,000 
MHz  of  satellite  microwave 
channels  in  1971.  Oddly 
enough,  time  has  not  seemed 
to  increase  their  enthusiasm 
for  giving  up  what  they  con- 
sider their  frequencies  for  a 
white  man's  hobby. 

The  ARRL  complacency  Is 
reassuring  to  many  amateurs. 
A  reading  of  the  report  In  QST 
of  what  happened  in  1971  when 
the  ARRL  went  to  the  ITU  at 
Geneva  to  preserve  our  ham 
satellite  frequencies  and  lost 
virtually  everything  might 
dispell  some  of  that  com- 
placency. Well,  since  it  is  now 
far  too  tate  to  do  anything 
about  it,  why  fret  more.  Let's 
just  wall  and  see.  ff  we  come 
out  okay,  we  saved  a  lot  of 
needless  worry.  If  we  lose  our 
shirts,  then  we  can  indulge  in 
an  orgy  of  recriminations.  I'm 
not  sure  how  the  League  will 
work  things  around  to  put  the 
biame  on  me,  but  they  man- 
aged it  with  'Incentive  Ticens- 
ing,*'  so  I  have  a  profound 
respect  for  their  ability  to 
rewrite  history  and  get  gullible 
amateurs  to  buy  it. 

Rather  than  spend  a  lot  of 
time  on  WARC,  I  see  the  ARRL 
tied  up  with  a  whole  rash  of  pet- 
ty squabbling.  Their  persecu- 
tion of  Mary  Lewis  and  their 
dedication  to  preventing  her 
from  being  the  first  woman 
ARRL  director  has  resulted  in  a 
lawsuit.  Their  insurance 
scheme  has  come  a  cropper 
and  must  betaking  a  lot  of  time 
to  hassle.  Then  there  \s  a  suit 
pending  with  Al  Ogden,  chal- 
lenging the  ARRL  to  put  up  or 
shut  up  on  keeping  Techni- 
cians from  holding  office  in  the 
League,  The  ARRL  Foundation 
mess  is  coming  apart,  despite 


heroic  efforts  to  cover  up  the 
situation  . . .  which  is  tied  in 
with  the  almost  total  inaction 
on  solving  the  real  WARC  prob- 
lems. 

Recent  efforts  to  try  to  scut- 
tle  the  Canadian  Amateur 
Radio  Federation  have  been  ty- 
ing up  many  HQ  staffers.  CARF 
seems  to  be  weathering  the 
battle  rather  well  and  we  see 
more  and  more  Canadians 
resisting  the  carpetbaggers 
from  south  of  their  border.  They 
still  have  time  to  harass  hams 
who  write  In  with  a  beef.  One  re- 
cent sample  was  Terry  Staudt^ 
who  wrote  to  Baldwin  with  a 
complaint  and  for  his  trouble 
found  Baldwin  trying  to  get  him 
fired  rather  than  answer  his 
complaints, 

ARMA  (the  Amateur  Radio 
Manufacturer's  Association) 
members  got  uptight  over  the 
ARRL  Code  of  Ethics.  They 
didn't  object  to  the  concept,  on- 
ly the  jamming  of  it  down  their 
throats.  They  called  Baldwin  on 
the  carpet  and  demanded  some 
explanation  for  the  QST 
editorial  claiming  heavy  in- 
dustry support  for  the  scheme. 
Baldwin,  according  to  the  in- 
dustry people  Tve  talked  with, 
came  out  a  liar  in  their  estima- 
tion. He  was  totally  unable  to 
back  up  his  editorial  with  facts. 
The  industry  is  further  very 
upset  over  the  new  ARRL  push 
to  set  the  prices  to  be  charged 
for  ham  gear  and  to  force 
manufacturers  to  have  a  sam- 
ple unit  tested  in  the  ARRL  labs 
before  it  can  be  advertised  in 
QST.  It*s  the  arrogance  that 
really  gets  to  the  industry  peo- 
ple. 

If  the  League  would  spend  a 
fraction  of  the  time  they  invest 
in  petty  harassing  of  hams  who 
are  critical  of  them  and  in  mak- 
ing life  difficult  for  the  industry, 
they  would  have  plenty  of  time 
to  attend  to  the  more  important 
matters  such  as  WARC,  and  I 
don't  mean  the  relatively  in- 
significant WARC  meetings  in 
Washington.  The  votes  of  the 
other  153  countries  are  going  to 
determine  what  amateur  radio 
is  like  in  the  80s,  not  what  hap- 
pens in  Washington. 

ARMA  members  were  as- 
tounded when  Noel  Eaton 
(ARRL-IARU)  reported  to  them 
in  Atlanta  this  year  that  nothing 
whatever  had  been  done  or  was 
in  prospect  to  approach  the 
44-vote  African  black  bloc  to  try 
to  get  their  support  for  amateur 


radio  at  WARC.  It  appears  that 
the  whole  future  of  amateur 
radio  is  being  left  entirely  to 
chance.  Good  iuck. 

ARRL  BUSINESS 

!f  the  ARRL  isn't  busy  trying 
to  cope  with  the  WARC  situa- 
tion, then  what  are  they  doing 
. . .  besides  trying  to  cut  ex- 
penses by  firing  people?  Oh, 
they're  busy  with  a  multitude  of 
problems  , . .  such  as  the  in- 
surance program  which  seems 
to  be  giving  them  more  and 
more  troubles.  They  may  really 
be  in  the  soup  on  that  one.  Then 
there  is  the  project  to  try  to  stop 
Mary  Lewis  from  getting  to  be 
the  first  woman  ARRL  director 
. . .  this  seems  to  be  getting  into 
court.  The  incumbent,  Thurs- 
ton, has  been  a  terrific  yes- 
man,  so  he  would  be  a  serious 
loss  to  HQ,  particularly  since 
Mary  Is  the  kind  of  person  who 
does  not  knuckle  under  easily 
. . .  as  they've  found.  Another 
big  time  waster  is  the  HQ  battEe 
to  prevent  a  Technician  class 
ham  from  getting  elected  as  a 
vice  director.  Al  Ogden,  a 
Technician,  is  challenging  this 
bias  In  a  court  case.  Then  there 
is  Terry  Staudt,  a  ham  who  had 
the  gall  to  write  Baldwin  with  a 
beef  and  who,  for  his  trouble, 
found  the  League  trying  to  get 
his  employers  to  fire  him  1  And, 
despite  monumental  efforts  to 
cover  it  up,  the  mess  with  the 
ARRL  Foundation  just  won't 
die.  Ask  your  director  about 
some  of  these  Incidents  the 
next  time  he  comes  to  your  ciub 
, , .  and  let  me  know  what  he 
says. 

With  ARMA  in  disarray  after 
their  African  plan  was  de- 
stroyed, the  League  is  back  to 
business  as  usuaL  ARMA  has 
been  trying  to  come  up  with 
some  ideas  on  other  things 
they  might  do  which  would  at- 
tract members,  such  as  work- 
ing up  a  ham  industry  exhibit 
for  use  at  trade  shows,  but  this 
seems  to  be  leaving  the  smaller 
firms  cold  since  they  wou  Id  get 
little  benefit  from  it.  ARMA, 
having  no  paid  staff,  has  to  de- 
pend on  volunteer  time  from  in* 
dustry  people*  In  general,  this 
is  in  very  short  supply,  for  most 
industry  leaders  are  already 
spread  thin  trying  to  keep  up 
with  their  own  work.  The  lack  of 
any  significant  benefits  to 
firms  supporting  ARMA  has 
kept  down  paid  memberships, 
thus  making  it  impossible  to 
have  a  paid  staff.  Until  ARMA 
comes  up  with  a  convincing 
goal  which  will  benefit  the  en- 
tire industry,  it  is  going  to  have 
tough  sledding  and  be  a  sitting 
duck  for  ARRL  pot^shotting. 

COWAN  PROMISES 

On  page  1  of  the  October, 
1976,  issue  of  CQ,  Dick  Cowan 
said,  ". .  .CO  has  slipped  badly 
In  both  circulation  and  adver- 


tising." He  went  on  to  say  that 
this  had  happened  because  he 
was  preoccupied  with  SB  and 
other  more  profitable  publish- 
ing ventures.  He  points  out  that 
"it  would  be  very  expensive  and 
time-consuming  to  rebuiSd  it/* 
Next  he  says  he  has  the  money, 
the  manpower,  and  the  know- 
how  to  rebuild  OQ,  and,  by  God, 
he  intends  to  do  just  that. 

Okay,  here  we  are  two  years 
down  the  pike.  All  that  money, 
manpower,  and  know-how  have 
resulted  in  a  magazine  that  is 
hardly  different  from  two  years 
ago,  running  about  six  or  eight 
articles  an  issue  (like  Ham 
Radio  Horizons).  There  has 
been  no  noticeable  change  ex- 
cept for  a  slight  increase  in 
advertising,  and  that  is  due 
primarily  to  the  yeoman  efforts 
of  Jack  Gutzeit. 

Far  from  being  first,  as  prom- 
ised, CQ  is  running  neck  and 
neck  with  Ham  Radio  Horizons 
for  last  place  . . .  getting  ads 
out  of  sympathy  more  than  per- 
formance. This  sympathy  can 
be  costly.  One  advertiser  com- 
plained to  me  that  he  had  run 
an  ad  and  been  incredulous  at 
the  reader  service  response.  He 
was  had  J  he  felt,  for  sending 
out  catalogs  costing  him  nearly 
$1,000  and  the  results  were  vir- 
tually nil.  Would  he  re-run  his 
ad  for  half  price?  No  way! 

The  secret  to  having  a  good 
magazine  is  no  secret  at  all. 
You  pay  authors  well  and  you 
pay  them  promptly,  not  after 
they  have  to  sue  you  for  pay- 
ment. This  will  bring  you  the 
cream  of  the  crop.  It  will  also 
bring  you  plenty  of  readers  who 
will  respond  by  buying  from 
your  advertisers.  You  really 
have  to  share  the  money  with 
the  authors,  not  take  it  all  and 
put  it  into  trains  and  yachts. 

There  is  no  real  secret  to  put- 
ting out  a  good  magazine  and 
getting  hams  to  read  it.  You 
have  to  give  good  value  ...  in- 
teresting articles  and  lots  of 
'em.  To  get  these,  you  must  pay 
money  . . .  funny  how  a  quick 
check  for  an  article  seems  to 
motivate  people. 

EXCITING  THE  FCC 

The  Tatest  catalog  from  Hen- 
shawls,  7622  Wornall,  Kansas 
Cpty  MO  64114,  should  get 
some  people  at  the  FCC  in  an 
uproar.  They  have  three  stores, 
the  others  in  Independence  and 
Ft.  Worth,  and  they  are  not  ham 
stores.  The  catalog  is  strictiy 
CB,  but  with  two  items  marked 
as  being  for  amateurs.  These 
are  Items  you  won't  find  in  a 
ham  store  catalog.  There  on  the 
back  cover  you'll  find  an  ad  for 
an  "amateur"  GW  transmitter. 
It  says,  "Illegal  to  modify  for 
use  as  a  CB  linear.''  This  gem  Is 
a  125-Watt  CB  linear  disguised 
as  a  10m  ham  transmitter.  As 
long  as  I  see  ads  like  that  right 
out  in  front  of  the  CBers,  I  have 


246 


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247 


no  confidence  that  the  FCC  has 
any  Intention  of  making  their 
CB  and  ham  linear  rules  stick. 
Oh,  ham  dealers  seifing  ampli- 
fiers which  cover  10m  to  hams 
will  get  ihe  full  treatment  from 
the  FCC,  but  CB  dealers  selling 
CB  linears  under  the  most 
transparent  of  covers  will  be  ig- 
nored by  the  FCC. 

The  other  gem  from  Hen- 
shaw's  is  a  10,5-GH2  police 
radar  jammer  which  is  called  an 
*'amateur  transmitter."  The  ad 
goes  on  to  say  that,  "This  may 
be  illegal  to  use  as  a  police 
radar  jammer."  This  $400 
gadget  can  be  set  to  Indicate 
speeds  of  20,  30,  40,  55,  or  60 
mph  on  police  radar.  Here  we 
go  again! 

SPEAKING  OF  10.5  GHZ 

When  Microwave  Associates 
came  out  with  their  cute  little 
10  GHz  units  a  couple  of  years 
ago,  I  got  quite  interested  and 
urged  our  then  editor  to  get  a 
couple  and  play  with  them.  He 
did  and  wrote  them  up,  but 
didn't  ever  otter  to  let  me  in  on 
the  fun.  Then,  when  he  left,  the 
10  GHz  stuff  left  with  him.  so  I 
rrstssed  out  completely. 

Weli,  almost  completely. 
Chuck  WA1KPS  of  Tufts  Elec- 
tronics recently  got  a  pair  of  the 
units  and  added  the  i4  strips 
which  turn  them  into  trans- 
ceivers. Since  I  have  one  of  the 
more  accessible  mountains 
just  up  the  street  (actually,  the 
mountain  had  a  lot  to  do  with 
my  picking  this  location  when 
we  moved  up  here  16  years 
ago),  Chuck  got  one  of  the 
transceiver  units  into  my  hands 
for  some  tests.  The  first  test 
was  between  Pack  Monadnock 
(NH)  and  Blue  Hill  (MA). 

I  had  it  easy,  having  only  to 
pack  the  10  GHz  rig  and  a  cou- 
ple of  HTs  in  the  73  van  and 
head  up  the  road.  The  road 
goes  right  to  the  very  top,  I  then 
climbed  up  into  the  fire  tower 
and  set  up  my  system,  coor- 
dinating it  on  223.5  MHz 
simplex.  Chuck  had  a  more  dif- 
ficult time,  having  to  carry 
everything  up  from  a  parking  lot 
to  the  top  of  his  mountain,  a 
20*minute  hike.  It  was  worth  the 
trouble,  for  the  signals  came 
through  full  quieting  over  the 
58-mile  path. 

All  is  not  beer  and  skittles  for 
the  pioneer,  I  forgot  to  bring 
gloves  and  the  wind  was  icy 
cold  up  there  In  the  framework 
of  the  fire  tower,  so  1  about  got 
frostbite.  It  was  worth  it  once 
we  got  the  two  rigs  tuned  to 
each  other;  This  Is  no  simple 
matter  when  your  hands  are 
cold  and  the  wind  is  blowing 
you  around. 

As  I  was  driving  back  down 
the  mountain,  fired  with  the  en- 
thusiasm of  success,  I  got  to 
thinking  about  Pack  Monad- 
nock, I've  spent  many  a  night 
on  that  mountain  working  far- 


off  repeaters  . . .  particularly 
back  about  ten  years  ago  when 
there  weren't  so  many  of  them. 
From  that  location  I  had  no 
probl<em  working  repeaters  in 
Maine,  Vermont,  Massachu- 
setts, and  even  down  into  Con- 
necticut, i  couldn't  quite  make 
any  Rhode  Island  repeaters  ex- 
cept under  belter  than  average 
conditions.  Why  not  see  what 
DX  we  could  work  on  10.5  GHz? 

Chuck  is  a  sucker  for  any- 
thing to  do  with  amateur  radio^ 
so  a  few  days  iater  he  was  tak- 
ing a  day  off  from  the  store  and 
heading  for  Mt.  Ascutney  in 
Vermont  (they  have  a  splendid 
76  repeater  on  Ascutney). 
Again  I  pooped  on  up  the  Pack 
and  coordinated  via  first  2m, 
then  223.5  MHz  until  we  made 
the  contact  on  10.51  Again 
Chuck  had  quite  a  hike  to  the 
top,  carrying  the  10,5  rig  plus 
his  HTs.  It  was  even  colder  than 
the  previous  contact  and  it  took 
about  15  minutes  before  we 
finally  got  everything  tuned  up 
right  and  had  full  quieting 
clean  signals.  We  were  afraid 
for  a  while  that  we  might  not 
make  it.  The  distance  was  only 
52  miles,  but  it  was  over  some 
very  rough  terrain. 

Well,  the  day  was  still  early, 
so  why  not  drive  on  over  to 
Maine  and  up  to  the  top  of  Mt. 
Agamenticus,  near  Ogunquit, 
Chuck  climbed  back  down 
Ascutney,  packed  everything  in 
his  van,  and  drove  clear  across 
New  Hampshire  and  to  the  top 
of  Agamenticus,  This  was  a 
6d.5-mile  hop,  so  it  would  be 
stretching  the  ability  of  the  tiny 
rigs.  We  were  using  them  bare* 
foot,  with  only  the  little  horn 
antenna  which  Microwave 
Associates  furnishes. 

By  late  afternoon,  Chuck  was 
on  top  of  Agamenticus  and  I 
was  back  up  on  the  fire  lower 
on  the  Pack,  listening  carefully 
and  aiming  the  rig  at  where  I 
thought  his  mountain  should 
be.  Once  Chuck  heard  me  call- 
ing and  tuned  me  in,  t  was  able 
to  aim  the  rig  a  bit  better  and 
peak  the  signals  to  perhaps  an 
S*7.  Hmmm,  that  made  three 
states  on  10.5  GHz,  Not  a 
record,  but  not  bad. 

A  couple  days  later.  Chuck 
was  off  to  Rhode  Island  for 
another  try.  This  time  we  were 
looking  at  a  69*mile  path,  but 
with  some  formidable  moun- 
tains right  along  the  route. 
Chuck  first  had  to  get  permis- 
sion to  climb  the  tower  on  the 
hill  (there  are  no  mountains  in 
Rhode  Island).  This  turned  out 
to  be  a  production  in  itself. 
Then,  when  he  got  there,  he  had 
to  climb  the  hill,  which  took  on 
the  proportions  of  a  mountain. 
Next  he  had  to  climb  Ihe  ce- 
ment base  of  one  leg  of  the 
tower  and  work  his  way  up  the 
tower  framework  until  he  got  to 
the  ladder  at  the  20- foot  leveL 
From  there  it  was  a  bit  easier. 


climbing  the  wet  and  very  cold 
tower  in  the  wind,  holding  on  to 
the  fig  with  one  hand,  pockets 
bulging  with  the  HTs,  and  hold^ 
ing  on  very,  very  tight  with  the 
other  all  the  way  up  to  the 
150-foot  level. 

While  Chuck  was  trying  to 
aim  the  rig  and  not  fall  off  the 
tower,  his  fingers  gradually 
freezing  in  spite  of  his  gloves,  I 
was  getting  cold  clear  through 
up  on  the  Pack.  I  was.  as  usual. 
Inadequately  dressed  and  with- 
out gloves.  The  wind  was  cold 
and  brisk,  and  the  entire  top  of 
ihe  mountain  was  engulfed  in  a 
thick  cloud.  We  tried  to  get 
through,  but  even  the  223,5  HTs 
were  not  doing  very  well.  We 
were  doomed  by  the  clouds,  if 
not  by  anything  else.  Those 
10.5  GHz  signals  drop  dead  in 
clouds  or  even  In  rain,  so  we 
really  didn't  expect  to  make  it. 
Wedidn*t. 

Chuck  has  been  going  over 
the  maps  looking  for  a  hill  in 
Connecticut  which  might  have 
a  good  iine-of-sight  path  to  the 
Pack.  The  fire  warden  on  the 
Pack  says  you  can  see  Ragged 
Mountain  in  Connecticut  on  a 
clear  day,  so  perhaps  weMI 
make  it. 

Oddly  enough,  we  had  not  yet 
worked  New  Hampshire,  so  one 
recent  Sunday  Chuck  packed 
everything  into  his  van  and 
headed  up  here.  After  visiting 
the  Pack  to  see  how  visible 
some  of  the  mountains  were  up 
north,  he  headed  for  Mt.  Wash- 
ington. There  was  no  time  to 
lose  since  the  road  to  the  top 
would  be  closing  the  next  day 
for  the  winter.  The  auto-road 
people  warned  that  the  top  of 
the  mountain  was  in  a  cloud 
with  250-foot  visibility.  Well, 
perhaps  it  would  blow  off  and 
we'd  make  It, 

After  allowing  Chuck  enough 
time  to  reach  Mt-  Washington 
(6,288  feet,  the  highest  point  In 
New  England),  I  called  him  on 
the  Mt.  Washington  repeater  on 
67.  He  was  stuck  at  the  base, 
wattmg  out  a  long  line  of  cars 
waiting  to  pay  the  $7,50  toll.  I'd 
had  to  wait  almost  a  half  hour 
to  get  up  the  Pack,  this  being  a 
Sunday  at  the  peak  of  the  fall 
foliage. 

Eventually,  he  got  through 
the  toll  gate  and  made  it  to  the 
top  of  the  mountain.  It  was  still 
socked  in,  so  1  had  little  hope 
for  a  contact.  We  had  mea- 
sured the  path  on  the  map  and 
it  was  106  miles,  which  seemed 
a  lot  for  the  tiny  rigs.  We  set  up 
anyway,  with  me  in  gloves  and 
a  heavy  Jacket  for  a  change.  I 
was  only  braving  temperatures 
In  the  40s,  while  Chuck  had  15 ' 
and  a  40  mph  wind.  We  tried  to 
gel  through  until  frostbite 
started  to  set  in  on  Washing* 
ton.  The  top  of  the  mountain 
was  teed  over  with  rime  ice  and 
the  clouds  were  still  heavy. 

After  the  three  and  a  half  hour 


drive,  a  half  hour  wait  In  line, 
and  the  long  drive  to  the  top, 
plus  the  fact  that  this  would  be 
the  last  chance  to  try  the  path 
until  next  summer,  Chuck  was 
not  about  to  give  up  without 
one  more  try.  He  set  up  in  the 
parking  lot,  maybe  a  couple 
hundred  feet  down  from  the 
top,  and  we  worked  at  it.  The 
clouds  parted  for  a  moment 
and  there  it  was  , . .  "W2NSD, 
this  is  WA1KPS,"  1  acknowl- 
edged it  and  we  had  a  contact, 
lt*s  funny,  but  you  can  hear 
your  own  voice  coming  through 
the  system  when  you  have  a 
contact.  This  was  a  weak  one 
and  didn't  last  but  a  couple  of 
minutes  before  the  clouds  were 
in  again  and  it  was  lost.  I  could 
always  teil  Just  how  well  Chuck 
was  tuning  in  my  signal  by  how 
clearly  I  could  hear  my  voice 
coming  back. 

Next  spring,  when  we  see  a 
particularly  clear  day  In  pros- 
pect, perhaps  we  will  again 
head  for  the  mountains.  I 
measure  1 50  miles  between  Mt, 
Grey  lock  in  Massachusetts  and 
Mt.  Washington.  Til  bet  we  can 
make  it.  In  the  meanwhile,  you 
can  be  sure  that  we'll  be  work- 
ing on  Connecticut  and  Rhode 
Island.  The  very  eastern  edge  of 
New  York  might  just  be  reach- 
able, too.  Who's  worked  seven 
stales  on  10.5  GHz? 

SOME  NEVER  LEARN 
DEPARTMENT 

While  on  the  one  hand  many 
amateurs  are  trying  to  get  the 
FCC  to  live  up  to  its  promise  to 
deregulate  amateur  radio,  on 
the  other  a  few  amateurs  are 
trying  to  tie  us  up  again  with 
more  rules.  I  seriously  doubt  If 
any  of  the  amateurs  who  went 
through  the  FCC  repeater  rules 
screw-up  are  in  any  way  in- 
volved with  the  present  move  to 
try  again  for  repeater  regula- 
tion by  the  Commission. 

The  sooner  amateur  groups 
stop  trying  to  solve  their  prob- 
lems by  getting  more  rules  from 
the  FCC  and  tackle  their  prob- 
lems directly,  the  more  we  will 
be  in  control  of  our  future.  What 
amateurs  who  are  pushing  for 
more  regulations  are  saying  is 
that  they  don't  want  to  either 
take  the  time  or  make  the  eftort 
it  requires  to  solve  their  prob- 
lems. 

Yes,  I  am  all  too  familiar  with 
the  repeater  situation  where 
any  amateur  can  set  up  a  re- 
peater and  mess  things  up  for 
hundreds  of  others.  I  also  know 
there  are  some  reasonable 
solutions  to  this  problem  for 
those  who  tackle  the  situation 
with  determination. 

The  first  step  is  for  the  local 
repeater  counci  I  to  decide  what 
has  to  be  done.  If  there  is  an  u n- 
coordinated  repeater  in  the 
area,  get   the  other  repeater 

Continaed  an  psge  254 


248 


CALL  TOLL  FREE 


I    I 


Communications  Center 

443  N  48ih  Street 
Lincoln.  Nebraska  68504 
tn  Nebraska  Call  (402)466-8402 


^058 


I     I 


Communications  Center 

West 

1072  N,Rancho  Drive 
Las  Vegas.  Nevada  89 106 

In  Nevada  Call  (702)647-3114 


18HT 


master  cnarge 


tm  WTl:' 


TH6-DXX 

TH3-MK3 

Hy>Quad 

TH3Jr. 

18  HT 

14AVQ/WB 

18AVT/WB 

203 

205 

208 

214 


Classic  33 
Classic  36 
TA-33 
TA-36 
TA-33  Jr. 
TA-40KR 


ATB-34 

ARX-2 

A147-20T 

A144-10T 

A144-20T 


4BTV 
RM-75 
RM-7SS 
G  6- 144- A 


HY-GAIN 

Super  Thuoderbird 
3ele,  10,  15,  20  Mtr.  beam 
2ele,  Quad  10,  15,  20  Mtr. 
3ele,  10,  15,  20  Mtr.  beam 
Hv'Towef  10*80  Mtr.  Vertical 
10-40  Mtr,  Trap  Vertical 
10  80  Mtr,  Trap  Vertical 
3  ele.  2  Mtr.  beam 

5  ele.  2  Mtr.  t>eam 
8  ele.  2  Mtr.  beam 
14  ele.  2  Mtr.  beam 

MOSLEY 

3efe,  10,  15.  20  Mtr.  beam 

6  ele.  10,  15,  20  Mtr.  beam 
3  ele.  10,  15,  20  Mtr.  beam 
6  ele,  10,  15,  20  Mtr,  beam 

3  ele.  10,  15,  20  Mtr-  beam 
40  Mtr.  add  on 

CUSHCRAFT 

4  ele,  to,  15,  20  Mtr.  beam 
2  Mtr.  Ringo  Ranger 

2  Mtr.  Twist 

10  ele.  Twist  2  Mtr. 

20  ele.  Twist  2  Mtr. 

HUSTLER 

10-40  Mtr,  Trap  Vertfcat 
75  Meter  Resonator 
75  Meter  Super  Resonator 
6db.  2  Mtr,  Base  Cojinear 


WILSON 

System  One  5efe.  10,  15,  20  Mtr.  beam 
System  Two  4  ele.  10,  1 5,  20  Mtr.  beam 

CDE  ROTORS 

Ham  III  $125,00 

T2X  Tail  Twister  S225.00 


CUSHCRAFT 
ATB-34 

Regular  Special 


$296.95 

219.95 

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144.50 

299,95 

67,00 

97.00 

14.95 

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232.50 
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335.25 
151.85 
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259,95 
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15.50 
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$209.95 
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82.95 
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239.95 

189.95 


*' 


MOSLEY  CL-36 


ra*» 


miSHP 


RtNGO 
RANGER 


4BTV 


We  carry  aU  major  brands  of  ham  radios 

AT  DISCOUNT  PRICES 


Yaesu 
Ten-' 


—  Kenwood  —  Drake —  ICOAA 
Swan  —  Tempo  —  Midland  — 


—  Dentron — - 
E.T.O.  — Wilson 


BankAmeaicaro 


(<''  Readar  Service — see  page  323, 


249 


James  ^yma  WA7DPX 

SIS  W.  JOih  Sl 

Casa  Grande  AZSS222 


Fail-Safe 


protecting  repeater  batteries 


Most  repeater  owners 
want  to  have  a  bat- 
tery on  the  repeater  so  that 
the  system  will  continue  to 
function  during  a  power 
failure.  But  the  problem  is, 
how  do  you  keep  the  bat- 
tery charged  up  so  it  will 
work  when  you  need  it? 

The  following  circuit 
came  about  as  the  result  of 
a  need  for  a  battery  charg- 
ing  circuit  for  our  371.97 
repeater  in  Casa  Grande, 
Arizona.  The  following 
capabilities  were  needed 
on  the  charger: 

1.     Normal  charging  — 


turn  charger  on  at  approx* 
imately  12.5  V  and  off  at 
approximately  15  V. 

2.  Low-voltage  fail- 
safe in  the  event  of  charger 
failure,  approximately  11.5 

3.  Overvoltage  fail-safe 

in  the  event  of  malfunction 
in  charger  turn-off  sensing, 
approximately  15.5  V. 

4.  Battery  connected 
to  110  V  ac  line  only  during 
charging  period- 

The  obvious  question 
that  comes  to  mind  is, 
''Why  not  just  float  the  bat- 


tery?" In  my  experiences  as 
a  two-way  service  techni- 
cian, 1  have  found  that  the 
majority  of  lightning- 
caused  damage  is  because 
of  lightning  hits  on  the 
commercial  power  line. 
With  this  in  mind,  it  was 
figured  that  the  probability 
of  damage  would  be  great- 
ly reduced  if  the  battery 
were  only  hooked  to  the 
charger  for  the  2  to  3  hours 
per  week  when  it  was 
charging.  If  you  don't  ex- 
pect to  ever  get  hit  with 
lightning  at  your  site  or  if 
you   like  to  gamble,  then 


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QMD 

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iCa  MCOO   OH   MOO  QUJCLQ  NANO 

01.02  m&*& 

0X0^   IM4DQZ 

SCfll       ZHm  OR  ?«I3S3£ 

(*C  ITO-7*0«  I20K  CniW91 

1^  v-102  15*  OHl*iJ 

Cr  PC--     4    25V   ELECT 

CZ  IpFf^   .5  ,    ILEGT 

C3,  C«     l|iF  ^  i^V 


Fig.  i.  All  fixed  resistors  are  V4-Watt  10%.  The  PC  board  mates  with  a  15-pin  edge 
conriector. 


skip  this  article  and  jump 
over  to  the  next  one. 
However,  if  you  ^re  a 
natural  pessimist  like 
myself,  read  on.  (Re- 
member Murphy's  Laws:  If 
it  can  possibly  go  wrong,  it 
will  If  it  is  impossible  for 
anything  to  fail,  it  still  will) 
Another  reason  for  using 
the  type  of  charging 
described  here  is  one  of 
battery  life.  A  battery  that 
is  on  a  continual  float  is 
likely  to  go  bad  much 
faster  than  one  that  is 
charged  and  recharged  on 
a  regular  basis.  The  follow- 
ing circuit  contains  all  of 
the  features  previously 
described. 

Circuit 

The  circuits  for  sensing 
charger  turn-on,  charger 
turn-off,  and  low- voltage 
disconnect  make  use  of 
three  sections  of  a 
Motorola  MC3302  quad 
voltage  comparator.  This 
device  provides  a  TTL- 
compatible  output  that  is 
at  a  high  stage  when  the 
inverting  input  is  below  the 
reference  voltage  (on  the 
noninverting  input).  When 
the  voltage  on  the 
inverting  input  is  equal 
to  or  higher  than  the  refer- 
ence voltage,  the  output 
switches  to  a  low  state  The 
reference  voltage  is  sup- 
plied by  an  MC7805CP 
regulator  chip.  Potentiom- 


250 


WR7AEK/WMDf=*X 

WiTTERV   CHARGER 
V0LTIK66    SEN5ING. 


Fig.  2.  PC  board 


eters  R1  and  R2  are  used  to 
set  the  switching  levels  for 
the  voltage  comparators. 
(Both  pots  act  as  voltage 
dividers  across  the  batterv 
voltage.)  (See  Fig.  1 J 

The  output  of  the  com- 
jarators  (lA  and  IB)  are 
looked  to  a  NAND  gate 
(1/4  of  a  7400  IC  section, 
2A)  which  drives  two  more 
sections  of  the  7400  chip 
(28  and  2C).  Sections  2B 
and  2C  are  hooked  in  what 
is  called  a  set-reset  latch 
configuration  (abbreviated 
S-R  latch).  The  device  is  ef- 
fectively an  on-off  switch 
(an  electronic  latching 
relay,  if  you  will). 

When  a  low  is  applied  to 
the  set  (S)  input,  the  output 
(Q)  goes  high  and  stays 
high.  The  Q  output  will 
stay  high  even  though  the 
low  on  the  S-input  is 
removed.  To  "turn  off"  the 
latch,  a  low  is  applied  to 
the  reset  (R)  input.  The  out- 
put will  stay  low  even 
though  the  low  on  the 
S-input  is  removed.  The 
Q-output  drives  an  MPS- 
A12  Darlington  amplifier 
transistor  (Q1)  which  acts 
as  a  relay  driver. 


Because  of  the  ex- 
tremely high  gain  of  the 
MPS-A12  (HpE  =  20,000), 
the  device  works  very  well 
at  TTL  levels.  The  device  is 
capable  of  switching  a  5(X) 
mA  load.  Q1  drives  relay 
Kl  which  is  used  to  switch 
the  110  V  ac  line  to  the  bat- 
tery charger.  A  relay  with  a 
good  gap  between  the 
normally-open  contacts 
should  be  used  so  that  line 
surges  (i.e.,  lightning  hits) 
will  not  jump  across  the 

gap- 

Let's  look  at  the  action 
of  the  circuit  during  a 
typical  discharge  and 
recharge  cycle.  The  logic 
states  for  the  output 
switching  points  are  shown 
on  the  schematic  to  make 
it  easier  to  follow.  Starting 
at  a  full  charge,  both  out- 
puts (pins  1  and  2  of  IC1) 
are  low;  hence  Kl  is  turned 
off  (the  S-R  latch  is  reset  by 
the  low  on  the  R~input  (pin 
2,  IC2).  As  the  voltage 
drops  below  15  V,  output 
pin  1  switches  high,  placing 
a  high  on  one  input  of 
NAND  gate  2A(pin13)„  In- 
put 2  of  IC2  is  still 
low,  since  the  voltage  is 


still  over  12.5  V.  When 
the  voltage  drops  below 
12  5  V,  ICIB  output  (pin  2) 
switches  high.  We  now 
have  both  gates  of  NAND 
gate  IC2A  high.  This  causes 
its  output  [pin  11)  to  go 
low.  This  low  makes  the  S-R 
latch  output  (Q)  go  high, 
turning  on  Q1,  which  pulls 
in  Kl.  Kl  turns  on  the 
charger.  As  the  battery 
charges,  the  output  of  IC1 B 
goes  low  when  the  voltages 
go  over  12.5  V.  The  battery 
will  continue  to  charge  un- 
til it  reaches  15  volts.  At 
this  point,  1C1A  output  will 
go  low.  When  this  happens, 
the  S-R  latch  is  turned  off 
by  the  low  on  the  R-input 
(pin  2,  IC2B).  Q  goes  low, 
which  turns  off  Kl  and 
disconnects  the  charger. 

The  remaining  two  sec- 
tions of  the  circuit  [IC1C 
and  Q4)  are  the  low- 
voltage  and  overvottage 
protection  fail-safe  circuits. 
The  circuits  are  referred  to 
as  fail-safe  because  a 
failure  that  actuates  either 
circuit  will  result  in  the  bat- 
tery being  disconnected 
from  all  circuits,  and  the 
charger    will    be    discon- 


nected from  the  ac  line. 
This  results  in  a  "safe''  con- 
dition where  the  battery 
cannot  be  damaged  by  ex- 
cessive discharge  or  over- 
charge* Either  of  these  con- 
ditions is  a  major  fault  that 
requires  technical  atten- 
tion. Consequently,  a 
nonreversible  disconnect 
(blowing  circuit  breaker 
CB1,  which  must  be 
manually  reset)  was  chosen 
to  accomplish  the  job. 

The  low-voltage  section 
of  the  circuit  uses  the  third 
section  of  IC1  as  the  sens- 
ing element.  Operation  is 
the  same  as  IC1,  A  and  B. 
When  the  voltage  goes 
below  11.5  V,  the  output  of 
1C1C  goes  high  through  D1 
to  the  gate  of  SCR1  The 
high  on  the  gate  causes 
SCR1  to  fire,  placing  a 
short  across  the  circuit 
breaker  and  battery, 
which,  of  course,  causes 
the  circuit  breaker  to  open. 
Since  the  coil  of  Kl  is  ac- 
tuated by  the  battery 
voltage,  the  relay  cannot 
pull  in  to  connect  the 
charger  to  the  110  V  ac 
line. 

The  remaining  section  is 


251 


WXXiiiA  CH¥HetH 


Fig.  3.  Component  layout 


the  overvoltage  protection 
circuitry.  This  is  a  conven- 
tional  "crowbar"  circuit, 
D3  and  CI  act  to  suppress 
negative  transients  which 
might  trigger  the  circuit 
When  the  voltage  exceeds 
15.5  V,  the  gate  of  the  UJT 
(Q4)  fires,  causing  a 
positive  pulse  to  be 
generated  at  base  one  of 
Q4,  The  pulse  is  coupled 
through  D2  to  the  gate  of 
SCR1,  which  blows  the  cir* 
cuit  breaker  as  previously 
described. 

Output  C  is  an  optional 
output  used  to  drive  a  tone 
generator.  The  purpose  of 
this  option  is  to  place  a 
tone  on  the  repeater 
transmitter  to  indicate  that 
the  battery  is  below  12.5 
volts  and  is  not  getting 
charged-  This  warning  will 
give  you  time  to  correct 
the  problem  before  the 
battery  drops  to  11.5  V  and 
is  shut  off  by  the  low- 
voltage  protection  circuit. 
Fig,  4  shows  an  example  of 
an  oscillator  that  could  be 
used  for  this  option.  If  you 
want  to  use  this  feature, 
lumpers  JU1  and  JU2 
should    be    installed    and 


resistor  R5  omitted.  If  the 
option  is  not  used,  jumpers 
]U1  and  I U2  should  be  left 
out  and  R5  installed.  Do 
not  install  the  jumpers  and 
the  resistor,  as  damage 
could  result  to  the  com- 
parator IC, 

Circuit  Adjustments 

The  voltage  levels  stated 
were  found  to  be  correct 
for  the  battery  we  were 
using  (a  2CX)  Ah  battery), 
However,  you  should 
check  your  specif  ic  battery 
to  determine  the  limits  you 
want  to  set.  The  main 
voltage  to  watch  is  the 
"full-charge"  turn-off.  The 
logical  thing  to  assume  is 
that,  when  the  battery  hits 
13.8  V,  it  is  fully  charged. 
That's  wrong!  The  battery 
must  be  brought  to  a  point 
above  that  for  it  to  take  a 
full  charge. 

The  best  way  to  deter- 
mine this  voltage  is  to 
discharge  your  battery. 
Run  it  down  to  about  12.5 
volts.  This  should  show  a 
'high  red"  area  on  your 
hydrometer.  Now  charge 
the  battery  at  the  rate  you 
intend  to  use  in  your 
system      Take    regular 


hydrometer  readings  until 
the  battery  shows  in  the 
"green"  on  the  float. 
Check  the  voltage  at  this 
point.  This  is  your  full- 
charge  turn-off  voltage. 
When  the  charger  is 
disconnected,  you  should 
read  approximately  13.8  V 
with  no  load  on  the  bat- 
tery. The  other  voltage 
levels  stated  should  be 
adequate  to  prevent 
damage  to  the  battery. 

The  easiest  way  to  set  up 
the  voltage  comparators  is 
with  a  variable  voltage 
power  supply  connected  to 
the  "BAT"  terminal  (pin  A) 
of  the  circuit.  Connect  a 
VOM  [12  V  descale)  to  pin 
1  of  IC1,  Set  the  power 
supply  for  15  volts.  Adjust 
R1  until  the  voltage  on  the 
VOM  changes  from  high  to 
low  (approximately  5  V  to 
less  than  .5  V).  Drop  the 
voltage  to  about  14  V  dc- 
Run  the  voltage  back  up  to 
15  V.  Make  fine  adjust- 
ments on  R1  until  the  out- 
put switches  to  a  low  at  ex- 
actly 15  V.  There  wilt  be  a 
very  distinct  switch  from 
high  to  low  at  the  output 
switching  points. 


Move  the  VOM  to  pin  2 
of  tCI.  Repeat  the  pro- 
cedure, but  set  R2  for  a 
switching  point  of  12.5  V 
dc.  Repeat  this  again  using 
ICI  pin  13  and  11.5  V  dc 
(Disconnect  the  gate  of 
SCR1  to  prevent  it  from  fir- 
ing.) Adjust  R3,  The  remain- 
ing adjustment  is  on  the 
overvoltage  circuits.  Con- 
nect the  VOM  (3  V  scale)  to 
D2  cathode.  Adjust  R4  for 
a  voltage  increase  (to  ap- 
proximately 1  volt)  at  15.5 
volts.  Run  the  voltage  back 
and  forth  a  few  times  to 
check  the  setting.  The  fir- 
ing voltage  should  be  a 
very  distinct  point.  Recon- 
nect the  gate  of  SCR1. 

After  making  all  ad- 
justments, give  the  circuit 
a  final  smoke  test  Start  at 
15  V,  The  relay  [KD  should 
be  unenergized.  Increase 
to  1 6  V,  The  circuit  breaker 
should  open.  Drop  to  15  V, 
Kill  the  power  and  reset  the 
breaker.  Drop  the  voltage 
slowly.  At  12.5  V,  K1 
should  pull  in.  Run  the 
voltage  back  up.  At  15  V, 
K1  should  open.  Drop  the 
voltage  down  to  11.5  V.  At 
this    point,    the    circuit 


252 


breaker  should  open  and 
K1  should  open.  Be  sure 
your  power  supply  has 
enough  current  to  blow  the 
circuit  breaker. 

Construction 

The  value  for  CB1 
should  be  chosen  to  meet 
the  requirements  of  your 
particular  station.  The  SCR 
listed  is  sufficient  to  han- 
dle at  least  a  25  Amp 
breaker.  If  a  fuse  is  used  in- 
stead of  a  breaker,  a 
smaller  SCR  could  prob- 
ably be  used.  Be  sure  to  tie 
all  unused  inputs  of  IC2 
to  +5  V  through  a  Ik 
resistor.  It  is  recommended 
that  a  74C00  CMOS  chip  be 
used  for  IC2  because  of  the 
higher  immunity  to  falsing 
that  it  has  as  compared  to 
the  7400.  The  extra  154  for 
the  CMOS  chip  shouldn't 
kill  you  unless  you  plan  to 
make  two  or  three  gross  of 
these  circuits.  All  other 
areas    of    construction 


should  be  pretty  straight- 
forward. The  circuit  can  be 
built  on  a  PC  board  (see 
Fig.  2)  or  perfboard,  which- 
ever suits  your  needs. 

The    printed    circuit 
board  was  set  up  so  that 

either  a  12  V  dc  or  6  V  dc 
relay  could  be  used  for  K1. 
If  a  12  V  dc  relay  Is  used, 
diode  D5  should  be  in- 
stalled with  the  cathode 
connected  to  the  12  V  line 
or  battery  (base  of  U3),  If  a 
6  V  dc  relay  is  used,  the 
cathode  of  D5  should  be 
connected  to  the  regulated 
5  V  dc  line  (E  of  U3).  The 
high  side  of  the  relay  coil 
would  be  connected  to 
+  12  V  dc  (pin  A  of  card)  or 
+  5  V  dc  (pin  C  of  card)  as 
required.  Do  not  omit 
diode  D5.  This  diode  is 
used  to  suppress  the 
counter  EMF  developed 
when  K1  is  turned  off:  The 
fow  side  of  the  relay  and 
the  anode  of  D5  are  always 


20^  ]r — )h 


^  fx  4UDI0 


/fr 


Fig.  4. 


connected  to  pin  D  of  the 
card. 

Fig.  2  is  a  full-size  draw- 
ing of  the  PC  board.  Fig.  3 
shows  the  parts  layout  for 
the  PC  board. 

Parts  can  be  obtained 
from  a  number  of  the 
advertisers  in  73.  However, 
to  save  you  time  and  prob- 
ably money,  arrangements 
have  been  made  with  Tri- 
Tek,  Inc.,  to  provide  all  of 
the  parts  [including  PC 
board)  in  a  kit  form.  You 
can,  of  course,  order  the 
entire  kit  or  just  the  parts 
you    need-   The  entire   kit 


can  be  ordered  by  asking 
for  a  "WR7AEK  battery 
charger  kit/'  [This  doesn't 
include  board  or  parts  for 
the  oscillator  option.)  The 
entire  kit  costs  $24  00.  (It 
includes  SCR1 ,  but  not  CB1 
or  the  edge  connector.)  The 
PC  board  alone  is  $6.00. 

I  have  made  every  effort 
to  make  the  text  and 
schematics  as  complete  as 
possible.  If  you  have  a 
problem  with  the  circuit 
that  I  can  help  you  with, 
drop  me  a  letter.  I  will 
make  every  effort  possible 
to  answer  your  questions 
[SASE,  please)  ■ 


Nen^  Products 


from  page  204 

W6T0G  RECEIVER 
MODIFICATION  KIT 

It  wasn't  until  I  began  using  a 
new  FT'901DM  that  I  finally 
concluded  that  my  trusty  FT- 
101 B  could  stand  some  im- 
provement in  the  receive  mode- 
With  the  two  rigs  tuned  to  the 
same  signal,  and  the  antenna 
switched  back  and  forth  be- 
tween them,  it  became  quite 
apparent  that  the  FT^QOIDM 
was  much  livelier,  t  was  also 
able  to  copy  weak  signals  very 
close  to  extremely  loud  signals 
that  all  loo  often  were  impossi- 
ble to  pull  out  with  the  FT-IOI B. 
Happily,  as  I  was  pondering  the 
situation  and  wondering  what 
might  be  done  to  punch  up  the 
older  rig's  performance^  one  of 
the  W6T0G  FT-101  series  re- 
ceiver modification  kits  arrived 
In  the  mail  from  S-F  Amateur 
Radio  Services. 

My  long-standtng  reluctance 
to  go  mucking  about  in  the 
densely^packed  solid-state  in- 
nards of  modern  rigs  was 
quickly  overcome  by  the  dis- 
covery that  only  four  small 
components  and  three  simple 
steps   were   involved   in   the 


modification.  The  fact  that 
things  can  be  quickly  and  easi- 
ly restored  to  their  original 
state  was  also  reassuring. 

According  to  the  instruction 
sheet,  the  purpose  of  the 
modification  is  to  'Improve  the 
receiver  sensitivity  and  help 
eliminate  receiver  blocking  due 
to  local  signals/'  That  sounded 
exactly  like  what  I  was  looking 
for,  so,  taking  screwdriver  and 
soldering  iron  in  hand,  I  pro- 
ceeded to  install  the  modifica- 
tion kit  in  my  FT-101B. 

The  Installation  procedure  is 
quite  simple.  You  locate  the 
receiver  rf  board,  remove  it,  find 
the  rf  amplifier  transistor  (Q1), 
and  replace  it  with  one  of  the 
transistors  from  the  modifica* 
tion  kit.  Then  you  locate  foil 
track  8  on  the  board  and  solder 
one  end  of  the  pair  of  back-to* 
back  diodes  supplied  with  the 
kit  to  the  track.  The  other  end  of 
the  diode  pair  is  soldered  to  foil 
track  7.  The  rf  board  is  then 
plugged  back  into  the  unit  and 
the  high  frequency  if  board  is 
removed.  Find  the  receiver  sec- 
ond mixer  transistor  (Q2)  and 
replace  it  with  the  remaining 
transistor  from  the  kit.  Replace 
the  board  in  the  transceiver  and 


the  modification  is  complete. 
The  entire  process  is  quite 
straightforward  and  takes  only 
a  few  mmutes. 

In  some  instances,  you  may 
find  that  after  making  the 
modification  you  will  have  to 
repeak  the  receiver  section.  If 
you  do,  be  sure  to  carefully 
follow  the  instructions  in  the 
alignment  sectton  of  your 
owner*s  manuaJ.  The  time 
spent  properly  tweaking  things 
up  wiEl  be  amply  rewarded  later 
by  improved  performance. 

The  installation  of  the 
W6T0G  receiver  modification 
kit  has  clearly  improved  the 
performance  of  my  FT-101  B. 
It's  livelier  than  ever  before, 
and  I'm  now  able  to  copy  sig- 
nals that  would  have  been  very 
difficult,  if  not  outright  im- 
possible, to  pull  out  of  the  crud 
in  the  past.  The  decision  as  to 
whether  or  not  you  should 
make  this  modification  to  your 
own  rig  is  one  you  will  have  to 
make  for  yourself,  and  depends 
largely  on  the  sort  of  operating 
you  do  and  the  conditions  you 
are  confronted  with  when  on 
the  air.  To  help  you  decide,  you 
may  want  to  write  to  S-F  Ama- 
teur  Radio  Services  for  a  copy 
of  the  combination  information 
sheet  and  order  form. 

In  addition  to  the  FT-101 
series,  there  are  receiver 
modification  kits  available  for 


the  FR-101  series,  TS*520. 
TS-520S  and  TS-a20/820S. 
There  is  also  the  "MAGICOf^'" 
processor  modification  kit 
which  converts  the  TS-820 
speech  processor  from  an  rf 
compressor  to  an  rf  clipper. 

W6T0G  receiver  modifica- 
tion kit  prices  are:  TS-520, 
$27,60;  TS'520S,  $32.50;  TS- 
820/820S.  $34.50;  FT-101  series, 
$32,50;  FR-101  series,  $34.50. 
The  ^'MAGICOM*^  processor 
modification  kit  for  the  TS-820 
IS  S27.50.  All  prices  are 
postpaid  from  S-F  Amateur 
Radio  Servtces,  43B4  Keystone 
Avenue,  Quiver  City  CA  9Q230: 
(213}  837^4870.  Reader  Service 
number  S33. 

Morgan  W.  Godwin  W4WFL 
Peterborough  NH 

S-F  RADIO  DESK 

I  used  to  set  up  my  first  rig  on 
a  small  folding  card  table  each 
time  I  wanted  to  operate*  and 
then  disconnect  everything  and 
put  it  away  in  a  cupboard  when 
I  had  finished-  Since  then  1  have 
used  quite  a  variety  of  objects 
to  hold  my  equipment  and 
serve  as  an  operating  position, 
including  an  old  rolltop  desk,  a 
kitchen  table,  a  garage  work- 
bench, basement  storage 
shelves,  and  a  bookcase.  For 
the  past  year  t  have  been  using 

Continued  on  page  262 


253 


W2NSD/I 

NEVER  SAY  DIE 

editorial  i^y  Wayne  Green 


from  p&g$  248 

groups  to  cooperate  toward 
getting  it  off  the  air.  You  can't 
telt  me  tliat  an  uncoordinated 
repeater  can  stick  it  out  wl^en 
several  hundred  local  harns 
decide  that  ft  should  not  be  on 
the  air.  There  should  be  no 
problem  at  all  working  up 
teams  of  amateurs  to  drive  the 
scoundrel  off  the  band.  Hun- 
dreds of  tape-recorded  mes- 
sages played  through  the  of- 
fending repeater  demanding 
that  It  be  taken  off  the  air  might 
encourage  it  to  be  shut  down- 
VtsHs  to  the  owner  of  the 
repeater  by  rather  large  groups 
of  determined  hams  might  also 
get  the  idea  through. 

There  are  a  great  many  ways 
of  tackling  the  situation,  and 
the  mabtlity  to  cope  with  it  is  an 
admission  that  the  repeater 
owner  Is  smarter  than  your 
group.  Let's  use  brains  instead 
of  trying  to  get  the  government 
into  the  act.  Remember  that 
once  you  get  the  FCC  moving, 
you  wHI  have  one  hell  of  a  Job 
stopping  them.  The  FCC  invar- 
lably  overreacts  to  things  like 
this.  It's  the  way  government 
works.  Don't  mess  with  it. 

If  repeater  councils  feel  they 
are  not  mentally  equipped  to 
cope  with  some  of  the  local 
repeater  owners,  perhaps  they 
should  get  together  with  other 
nearby  councils  and  try  to 
locate  someone  in  the  group 
with  some  ideas.  There  are 
always  a  tot  of  ways  of  tackling 
problems ...  if  you  have  a 
creative  thinker  handy, 

YOU  MISSED  BOXBOROUGH 

Despite  a  heavy  all-day  rain 
(or  perhaps  because  of  it),  ex* 
hibitors  at  the  ARRL  conven- 
tion at  8oxborough  (Massachu- 
setts) set  all-time  records  for 
equipment  sales.  Many  were 
delightedly  reporting  double 
and  triple  the  sales  of  Dayton, 
previously  the  top  hamfest  for 
cash  sales. 

One  reason  for  the  tremen- 
dous sale  of  ham  gear  was  the 
recent  price  increases.  Dealers 
at  the  convention  had  bought 
at  the  old  prices  and  were  sell- 
ing at  discounts  off  the  old 
prices,  so  hams  found  them- 
selves in  a  wonderland  of  fan- 
tastic prices.  They  reacted  by 
buying  everything  fn  sight.  OSI 
was  there  with  their  new 
counters  and  sold  out  com- 
pletely on  Saturday.  By  Sunday 


morning  they  had  a  new  stock, 
flown  in  overnight. 

The  New  England  ARRL  Con- 
vention is  an  odd  one  in  many 
ways.  For  many  years  it  was  run 
at  the  old  Swampscott  Ocean 
House.  Then  one  year  the  hotel 
burned  to  the  ground  Just  a 
month  before  the  convention 
and  the  event  had  to  be  moved 
to  Boston.  This  was  not  a 
popular  move,  considering 
Boston  hotel  and  parking 
prices-  They  tried  Cape  Cod 
one  year  and  found  that 
Greater  Boston  hams  were  not 
about  to  drive  that  far  for  a  con* 
vention.  The  new  convention 
complex  on  Route  495  (the 
Boston  outside  perimeter 
road),  the  Sheraton  hotel  at 
Soxborough,  is  a  fine  location 
and  met  with  ham  approval.  It  is 
estimated  that  well  over  5,000 
turwiJ  put. 

I  say  estimated  because 
security  is  not  lax  at  this  show 
— It  doesn't  exist.  If  you  want  to 
buy  a  ticket  and  have  a  chance 
at  the  multitude  of  prizes,  so  be 
it.  They  had  3,500  tickets 
available  and  ran  out  of  those 
early  in  the  first  day.  Tickets 
were  generally  bought  just  by 
the  ham  of  the  family,  with  the 
rest  tagging  along  at  no 
charge. 

Most  of  the  planning  for  the 
show  was  done  by  Gene  Hast- 
ings W1VRK,  an  old-timer  at 
this  event.  Exhibitors  had  some 
gripes  . . .  such  as  paying  $300 
for  a  booth  with  one  table  and 
one  chair,  extra  chairs 
available  for  $20  each  from  the 
show  decorator . . ,  only  to  find 
themselves  facing  flea  market- 
ers  in  the  exhibit  hall  who  had 
bought  a  table  and  two  chairs 
for  S4.  Even  worse*  some  of  the 
fleas  hung  up  their  business 
Signs  and  went  right  into  sell- 
ing commercially. 

The  flea  market,  which  was  a 
wet  mess  on  Saturday,  perked 
up  on  Sunday,  but  to  thinner 
crowds.  It  was  well  managed  by 
Jack  W1QXX,  the  keeper  of  the 
antennas  and  large  power 
behind  the  yearly  VHP  contest 
effort  from  Pack  Monadnock  in 
New  Hampshire,  Jack  will  also 
be  found  wherever  there  Is  a 
ham  auction,  a  tradition  going 
back  as  far  as  I  can  remember 
**.  when  there  is  an  auction, 
Jack  is  the  auctioneer.  He 
takes  these  things  seriously 
and  got  into  a  big  battle  with  an 
itinerant  badge  maker  who 
tried  to  set  up  in  hts  flea  market 


in  competition  with  the  one 
who  paid  for  a  booth  Inside  and 
had  an  exclusive  agreement. 
This  was  finally  settled  when 
the  inside  badge  maker  ran 
completely  out  of  badges.  Only 
then  would  Jack  let  the  flea 
market  badger  start  grinding. 

Despite  a  blanket  prohibition 
of  my  being  permitted  to  speak 
at  ARRL  conventions.  Gene 
managed  to  get  me  on  the  pro- 
gram twice,  once  speaking 
about  software  for  microcom- 
puters and  the  other  on  the  sore 
subject  of  WARC.  I  think  he  got 
the  software  talk  through  head- 
quarters by  not  telling  them  I 
was  going  to  do  the  talking.  My 
name  didn't  appear  on  the  pro- 
gram or  on  any  posters  In  con- 
junction with  that  talk.  I'll  bet 
he  had  a  battle  with  the  other 
one.  One  year  they  wouldn't 
even  let  73  buy  a  booth  and  ex- 
hibit at  Boston! 

Speaking  of  sore  subjects^ 
all  of  the  dealers  exhibiting  at 
the  show  were  absolutely 
furious  about  the  HR  special 
deal  with  the  ARRL...  ap- 
parently a  sweetheart  deal  . . , 
where  ARRL  Handbooks  were 
t>eing  sold  across  the  counter 
for  $4.25!  This  is  85«  teas  than 
wholesale,  so  dealers  were  left 
with  piles  of  Handbooks  which 
they  couldn't  sell.  The  book 
regularly  sells  for  S3.50,  so  HR 
was  selling  it  at  half  price  . , , 
wonder  what  they  had  to  pay 
for  it?  Wonder  what  laws  were 
broken  with  that  secret  deal? 

Despite  the  few  grumbles 
about  the  show,  there  is  no 
doubt  whatever  that  New 
England  needs  a  yearly  ham 
convention  in  the  Greater 
Boston  area.  Finding  the  spot 
for  It  is  the  big  problem.  The 
Sheraton  Boxborough  was 
hopelessly  overcrowded  by  the 
event.  You  couldn't  get  around 
on  Saturday.  The  exhibit  hall 
was  filled  with  about  70  booths 
. . .  perhaps  35  exhibitors.  The 
restaurant  couldn't  cope  with 
the  people,  not  having  brought 
in  extra  cooks  or  waitresses. 
They  had  lines  an  hour  long  and 
then  ran  out  of  food.  Unfor- 
tunately, there  are  no  fast  food 
places  within  easy  driving 
distance  of  the  hotel 

On  the  good  side,  this 
Sheraton  is  one  of  the  best  of 
the  chain.  Tve  had  such  lousy 
rooms,  service,  and  so  many 
problems  that  I've  been 
avoiding  the  Sheraton  chain 
like  the  plague.  I  had  breakfast 
there  before  the  crowds  arrived 
and  their  food  is  no  better  than 
elsewhere  at  Sheratons . . .  very 
poor.  But  the  decorations  were 
gorgeous  and  they  really  tried 
hard  to  make  sure  that  those 
with  room  reservations  had 
rooms. 

Perhaps  if  Gene  would  cut 
the  banquet  and  use  the  ban^ 
quet  halt  for  more  exhibits  .  .  .  ? 
And   please,   some   sort   of 


lounge  for  the  exhibitors. 


MORE  TROUBLE  BREWING 
A  newspaper  clipping  sent  in 
by  KA2CKV  is  enough  to  give 
us  a  bad  case  of  hives.  It  has  to 
do  with  a  proposed  city  health 
code  amendment  which  is  in 
the  works  In  New  York  City. 
This  has  to  do  with  setting  the 
levels  for  radio  field  strength 
for  emitted  radio  waves. 

If  this  beauty  goes  through,  it 
will  effectively  throw  most  of 
the  hams  in  New  York  off  the 
air.  Oh,  hand  transceivers 
might  escape  the  impact,  but 
most  hams  would  have  to  have 
their  antennas  a  minimum  of 
200  feet  from  anybody,  In  New 
York  that  kind  of  distance  is 
pretty  expensive  to  buy. 

At  least  there  Is  some 
fighting  of  the  proposed 
amendment  by  TV  broad- 
casters, since  they  would  have 
to  either  drastically  lower  their 
transmitted  power  or  else  move 
their  transmitters  out  of  town. 
Either  move  would  ruin  televi- 
sion pictures  for  much  of  the 
city  and  be  a  godsend  to  cable 
television  firms. 

Until  they  outlaw  irradiation 
by  police  radar  units,  who  ir- 
radiate us  with  roughly  5,000 
times  more  energy  than  is  per- 
mitted to  leak  from  microwave 
ovens,  they  should  lay  off 
amateurs.  The  problem  comes 
from  a  worry  about  rf  pollution. 
1  love  that  use  of  the  word 
"pollution/'  because  It  is 
ridiculous  in  this  context— yet 
is  a  great  emotional  phrase  for 
the  uneducated.  Who  can  be  in 
favor  of  "pollution?" 

The  fact  is  that  there  have 
been  no  definitive  tests  as  yet 
which  indicate  that  radio  waves 
cause  harm.  I've  been  around 
'em  for  over  40  years  now  . . , 
but  perhaps  that  would  be  a 
case  to  support  strict  control  of 
radio  transmissions.  Perhaps  I 
can  point  to  my  continual  ir- 
radiation by  signals  from  DX 
stations,  repeaters,  HTs,  and 
such  as  a  possible  reason  for 
the  weird  behavior  of  my 
children.  We  all  need  some  ex- 
cuse for  that,  right? 

If  New  York  gels  this  one 
through,  will  Los  Angeles  l>e  far 
behind?  Will  Peterborough 
pass  such  a  law  and  force  me 
to  move  my  antenna  at  least 
200  feet  from  myself?  There 
may  be  a  big  sale  of  200'foot 
towers  soon.  Should  w©  invest 
in  a  tower  firm? 

MORE  ASSISTANCE 

We  are  looking  for  a  couple 
of  hams  who  will,  In  exchange 
for  a  subscription  to  73,  for- 
ward mail  to  us.  We  have  a  mail- 
ing  list  we  rent  out  in  the  com- 
puter field,  and  we  need  to 
know  when  mail  is  delivered  to 
it,  how  long  it  takes  for  the  mail 
to  arrive,  and  if  the  use  of  our 
list   was   authorized.   Alt   our 


254 


^ 


assistants  have  to  do  is  date 
the  receipt  of  mail  and  forward 
it  immediately  to  os  for  our 
records. 

4U1ITU 

While  visiting  the  ITU  back  In 
June  to  check  on  the  prospects 
for  survivai  of  amateur  band 
aliocations,  I  paid  a  visit  to  the 
ham  station  in  the  ITU  buiiding 
in  Geneva- 
Here  I  am,  on  the  left,  with  my 
very  good  friend  Gerard  de 
Buren  HB9AW,  who  is  the  chief 
operator  at  4U1ITU,  We're  in 
front  of  the  ITU  building,  with 
my  little  rented  Fiat  reflected  in 
the  doorgiass. 

This  is  the  new  ITU  building, 
just  a  short  distance  from  the 
older  one,  where  4U1  ITU  is  still 
set  up.  H  the  African  vote  bloc 
has  too  much  influence  at  the 
WARC  meeting  next  October, 
will  it  destroy  the  whole  ITU 
bodyof  agreements  which  have 
been  built  up  over  the  last  hun- 
dred  years? 

I  thought,  if  I  didn't  show  you 
this  picture,  you  wouldn*t 
believe  my  report  that  one  of 
the  two  (only  two  these  days) 
stations  set  up  at  4U1ITU  is  an 
oid  CoiNns  system.  While  I  have 
nothing  in  the  world  against  us- 
ing one  of  those  lovely  old  rigs, 
still , . .  for  a  station  that  is  sup- 
posed to  be  used  as  a  demon- 
stration to  delegates  from  all  of 
the  countries  of  the  world, 
shouldn't   something    more 


lechnicalTy  modern  be  on 
display? 

Just  to  the  left  of  the  Collins 
equipment  is  one  of  the  new 
ARRL  low-cost  CW  rigs  for  im- 
poverfshed  amateurs.  This  was 
designed  as  a  solution  to  the 
problem  of  amateurs  not  being 
able  to  afford  the  average  nevw 
sideband  rig.  While  it  is  true 

that  amateurs  in  many  of  the 
small  countries  are  not  able  to 
afford  a  new  Yaesu  901,  the 
whole  concept  of  individual 
communications  is  an  anath- 
ema to  the  leaders  of  countries 
which  are  unstable,  and  that  In- 
eludes  virtually  every  one  of  the 
44-vote  African  bloc.  These 
countries  might  be  talked  into 
the  use  of  radio  clubs,  where 
operators  could  be  supervised, 
but  there  is  no  way  you  are  go* 
ing  to  get  very  many  individual 
amateur  stations  permitted.  It 
Is  Just  far  too  dangerous 
because  the  stations  could 
then  easily  be  used  for  subver- 
sive communications.  This  is 
why  the  chaps  at  the  ITU  are 
laughing  at  the  ARRL  and  their 
mini-rigs. 

if  you  find  yourself  within 
driving  distance  of  Geneva, 
stop  in  and  say  hello  to  afl  of 
the  hams  at  the  ITU , . ,  they  are 
a  great  bunch  and  you'll  enjoy 
the  visit.  Bring  your  license  and 
get  on  the  air  from  one  of  the 
smallest  "countries"  .., 
4U1(TU.  Be  sure  to  give  my  very 
best  to  Gerard. 


DXPEDmONING  HINT 

For  those  of  you  who  would 
like  to  get  a  little  taste  of  what 
it's  like  to  be  on  the  other  end  of 
the  pileups,  take  a  good  look  at 


the  most  interesting  Eastern 

Airlines   special    fares.   The 
chances  are  that  you  may  be 

Continued  on  page  277 


255 


Code-Practice  Oscillators 


an  exhaustive  report 


Hank  Oison  W6GXN 
1 75 1  CronerAve. 

Menia  Park  CA  94025 


From  the  earliest  days  of 
amateur  radio,  code- 
practice  oscillators  have 
been  an  integral  part  of  the 
process  of  learning  Morse 
code.  To  be  sure,  a  great 
deal  can  be  accomplished 


O0t|iF 


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PHONES      KEf    ^^*^ 


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Fig.   1.   Vacuum-tube  code 
oscillator. 


KEV 


Fig,  2.  Simplified  vacuum- 
tube  code  oscillator. 


by  copying  off  the  air  in 
terms  of  receiving  prac- 
tice, but,  for  group  instruc- 
tion with  a  teacher  or  for 
individual  keying  practice, 
the  code-practice  oscilla- 
tor is  a  necessity.  In  this  ar- 
ticle, I  will  take  a  look  at 
the  various  forms  of  code- 
practice  oscillators  and 
suggest  ways  of  improving 
them. 

Perhaps    the    simplest 


code-practice  oscillator  is 
an  electromechanical  buz- 
zer and  a  battery.  Such 
code-practice  sets  have 
been  widely  used,  and 
some  high-frequency  buz- 
zers for  this  purpose  have  a 
remarkably  ''pure''  note. 

Vacuum-tube  oscillators 
came  into  use  in  the  1930s, 
and  one  very  common  cir- 
cuit for  a  code-practice  os- 
cillator is  shown  in  Fig.  1,* 


JACH    OF 


Fig.  3,  Code-practice  oscillator  using  r]eon'bulb  relaxation 
oscillator: 


OMCS 


750 1   lL0yD1«€SS) 


fig.  4.   Code-pra ct/ce  oscillator  using  early  germanium 
NPN  transistor. 


In  earlier  designs,  a  type-30 
tube  was  usually  em- 
ployed. Note  that  the  key 
and  earphones  are  in  the 
B+  lead. 

A  simplified  vacuum- 
tube  code-practice  oscilla- 
tor was  also  possible  [one 
that  did  not  need  an  audio 
transformer)which  utilized 
the  inductance  of  the  ear- 
phones themselves,  in  a 
Colpitts  circuit.  This  is 
shown  in  Fig.  2;  the  ear- 
phones and  key  are  still  in 
the  B+  lead. 

Since  there  are  many 
forms  of  vacuum-tube 
oscillators  possible  (the 
tickler  feedback  and  Col- 
pitts versions  are  in  Figs.  1 
and  2),  it  is  possible  to  find 
considerable  variation  in 
code-practice  oscillator 
circuitry.  However,  gener- 
ally, the  oscillators  all  are 
simple  tickler  feedback, 
Cofpitts,  or  Hartley  oscilla- 
tors which  are  started  at 
each  application  of  the 
keyed  B  + . 

The  neon-lamp  relaxa- 
tion oscillator  was  occa- 
sionally used  as  a  code- 
practice    oscillator,    as 

shown  in  Fig.  3.^  This  unit 


256 


SOME 


msmfo 


ms\s 


Sooner  or  later  almost  all 
ordinary  ham  antennas  are 
going  to  become  victims  of 
bad  weather. 

But  Shakespeare's 
brand  new  line  of  two 
meter  and  HF  antennas  is 
an>ihing  but  ordinary. 

WeYe  new  to  the  ham 
market,  but  we've  been 
making  marine  and  mili- 
tary antennas  for  26  years. 

And  those  26  years  have 
taught  us  how  to  make  a 
ham  antenna  that'll  take 
just  about  anything  Mother 
Nature  can  dish  out. 

Look  at  our  5705  om- 
nidirectional VHF  base 
antenna,  for  example. 

Its  radiating  elements 
are  non-ferrous  brass  and 
copper,  the  finest  practical 
material  available  for  con- 
ductivity and  corrosion 
resistance.  Surrounding  the 


ffS 


Rberidass  protects 
radimingeleriient:^ 
from  raifi  und  ice. 
Therefore  no 


COfTOStCHL 


Rbcrglass  gives 
added  strength  to 
the  antenna.  J\e* 
veiils  breakage  in 
Hind  and  sleet. 


Fibert^lass  shield 
firotects  eteclncal 

Ciiinpaiunls  from 
eorrtmon  caused  liv 


Hber^ass  prevents 
rudiaiion  p^terns 
from  cliiinging  in 
net  weather. 


rain  or  jce. 


rf»- 


Tte  Mixif  1 57m 


V}W  Base  AntcnM 


And  you  don't  have 
to  worry  about  radials 
breaking  off,  because  the 
5705  do^n't  have  any. 

But  it  does  have  seven 
vertically  polarized  and 
phased  1/2  wave  elements, 
stacked  in  col inear  array 
and  providing  an  impres- 
sive 10  dB  gain. 

And  you  can  get  op- 
tional style  5709  reflector 
that  blocks  out  unwanted 
coverage  and  gives  you  an 
additional  2  dB  gain  in  the 
opposite  direction. 

And  here's  another  im- 
portant piece  of  informa- 
tion: the  5705  is  pre-tuned 
at  our  factory  to  operate 
in  all  environments.  So  it'll 
never  have  to  be  re-tuned. 

Our  full  ham  antenna 
line  is  featured  in  our  new 
catalog:  The  Cbmplete 


radiating  elements  and  electrical  components  is  a 
tough,  flexible  fiberglass  shield.  A  shield  that  gives 
the  antenna  the  strength  to  withstand  winds  in 
excess  of  120  miles-per-hour. 

The  fiberglass  keeps  out  rain,  sleet  and  snow 
too.  So  the  antenna's  radiation  pattern  won't 
change,  no  matter  how  bad  the  weather. 


Works  of  Shakespeare.  And 
the  catalog  is  yours.  For  free. 

For  additional  information  just  write  Shake- 
speare, Electronics  and  Fiberglass  Division,  Ctepart- 
ment  C,  Post  Office  Box  246,  Columbia,  South 
Carolina  29202. 

Or  call  National  Sales  Manager  John  Hughes, 
(803)  779-5800     WA4EAU. 


d^z^e^aea^e 


* 


UI12 


® 


-Jh- 


J 


Fig.    5.    Code-pracf/ce 

oscillator  using  early 
P-channet  FET. 

was  designed  to  be 
plugged  into  the  octal  ac- 
cessory jack  of  a  National 
receiver,  thereby  utilizing 
the  receiver's  speaker, 
audio  amplifiers,  and 
power  supply.  The  neon- 
lamp  relaxation  oscillator 
was  the  only  form  of  tube- 
type  RC  oscillator  com- 
monly used  as  a  code- 
practice  oscillator.  Unlike 
conventional  oscillators 
(which  produce  a  more  or 
less  sinusoidal  output),  the 
neon-bulb  relaxation  oscil- 
lator produces  a  sawtooth 
waveform. 

When  the  first  produc- 
tion (germanium)  tran- 
sistors became  available  at 
prices  low  enough  to  in- 
terest experimenters,  they 
were  immediately  pressed 
into  code-practice  oscilla- 
tor service.  Fig.  4  shows  a 
typical  early  transistor 
code  oscillator  using  a  ger- 
manium transistor./"  Note 
that  this  is  very  similar  to 
Fig,  2,  except  that  an  NPN 
transistor  replaces  the  tube 
and  a  lower  plate  (collec- 
tor) voltage  is  used.  The 
convenience  of  only  one 
low-voltage  battery  to 
operate  such  a  transistor 
code  oscillator,  and  that  at 
very  low  current  drain,  was 
a  real  boon  to  portability. 
The  circuit  would  be 
substantially  the  same  us- 
ing a  more  modern  silicon 
NPN  transistor,  such  as  a 
2N3641,  If  a  PNP  transistor 
is  used,  the  same  circuit  as 
in  Fig  4  can  be  built,  but 
the  battery  polarity  would 
be  reversed. 

As  FETs  became  avail- 
able,  these  were  also  used 
in  code  oscillators.  Fig.  5 
shows  a  simple  code  oscil- 
lator using  one  of  the 
earliest     available     P- 


channel  junction  FETs.* 
The  N-channel  circuit 
would  be  the  same,  except 
with  the  battery  terminals 
reversed.  The  FET  code- 
practice  oscillator  is 
generally  a  bit  simpler  than 
an  equivalent  bipolar  tran- 
sistor circuit 

It  must  be  made  clear 
that  in  all  the  oscillators  in 
Figs.  2,  4,  and  5,  the  circuit 
requires  the  use  of  mag- 
netic phones  having  an  im- 
pedance of  2000  Ohms  or 
higher,  tf  low-impedance 
phones  or  piezoelectric 
(crystal)  phones  are  used, 
the  circuits  do  not  have  the 
required  inductance  to  os- 
cillate at  the  correct  fre- 
quency (if  at  all). 

The  circuit  of  Fig.  3  used 
a  neon  tube  as  a  negative- 
resistance  element.  In 
order  to  redesign  the  cir- 
cuit for  solid  state,  one 
could  simply  replace  the 
NE2  with  a  four-layer  diode 
having  approximately  a 
50~volt  breakdown  voltage. 
Such  diodes  are  made  by 
ITT.  The  circuit  would  then 
be  as  shown  In  Fig  6.  Four- 
layer  diodes  are  available 
in  lower  voltages,  however, 
than  neon  bulbs,  so  a  relax- 
ation oscillator  could  be 
built  using  an  even  lower 
voltage,  i.e.,  battery  oper- 
ated. 

The  circuit  of  Fig.  7 
shows  a  unijunction  tran- 
sistor code  oscillator,  with 
an  FET  audio  isolation 
source-follower  after  it  to 
drive  the  phones  and  an 
NPN  transistor  as  a  keying 
device.  With  this  circuit, 
you  no  longer  have  the 
supply  current  flowing 
through  the  key,  and  you 
finally  have  removed  that 
same  dc  current  from  the 
phones.  [Dc  through  the 
phones  tends  to  eventually 
demagnetize  the  magnets 
in  them.)  The  unijunction 
transistor  oscillator,  like 
the  four-layer  diode  cir- 
cuit, produces  sawtooth 
waveforms. 

Fig.  8  shows  a  "com* 
plementary"  circuit  for  a 
simple  code  oscillator  that 
uses  an  NPN  (silicon)  and  a 


tJOOwi 


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itOOOff 


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Fig,  6, 


/?? 


Fig.  7,  Q1  =  2N3643;  Q2  =  2N2646;  Q3  =  MPF102. 


PNP  [germanium)  tran- 
sistor  which  has  been  used 
extensively  by  those  hams 
who  swear  by  the  ARRL 
Handbook.^  The  circuit 
works  well,  driving  an 
eight-Ohm  speaker  direct- 
ly, but  is  somewhat  sen- 
sitive  to  transistor  substitu- 
tions. 

Since  we've  used  nearly 
every  other  active  device 
as  a  code-practice 
oscillator.  I  feel  that  for 
completeness  I  should 
show  one  using  an  in- 
tegrated circuit  The  cir- 
cuit of  Fig.  9  uses  an  inex- 
pensive and  widely- 
available  IC.  The  NE555V, 
as  first  introduced  by 
Signetics,  is  now  second 
sou  reed  by  nearly  all  linear 
IC  manufacturers.  This  IC 
costs  about  50  cents  and  is 
keyed,  in  this  circuit,  by  a 
transistor  costing  about  30 
cents;  so  the  semiconduc- 
tor cost  is  well  below  a 
dollar.  The  key  is  not  in  the 
+  Vcc  line,  nor  are  the 
phones;  and  the  code  oscil- 
lator operates  on  a  6*volt 
battery  such  as  a  4F  lantern 
battery.  The  waveform  out- 
put is  essentially  a  square 
one. 

Up  to  this  point,  I  have 
concentrated  on  code- 
practice  oscillators  that 
have  as  their  prime  goals 
simplicity  and  the  use  of 


low-priced  components. 
This  aim  has  apparently 
been  in  vogue  because  it 
was  assumed  that  such 
oscillators  are  used  only  by 
beginners.  However,  there 
are  many  clubs  with 
regular  code  classes  con- 
ducted by  expert  CW 
operators,  who  no  doubt 
despair  at  the  sound  of  the 
average  code-practice  os- 
cillator. 

Morse  code,  as  it  comes 
out  of  the  receiver,  has  a 
somewhat  different  quality 
to  it  than  that  from  a  code- 
practice  oscillator.  The 
receiver  output  is  usually  a 
near  sine  wave  (providing 
the  station  being  copied  is 
'T9"  and  we  have  a  good 
signal-to-noise  ratio).  The 
note  sounds  as  if  it  simply 
"appears  and  disappears" 
rather  than  having  the 
"crashing"  quality  of  some 


Fig.  8.  Code  oscillator  using 
complementary-pair  (PNP 
and  NPN]  transistors.  Q1  — 
2N2102;  Q2  =  2N301, 


258 


code-practice  oscillators. 

In  a  search  for  a  code- 
practice  oscillator  which 
has  a  more  authentic  on- 
the-aif  sound,  the  first  re- 
quirement is  having  a  sinu- 
soidal waveform.  There  are 
a   number   of   circuits   for 


generating  sinusoidal 
waveforms;  one  such  cir- 
cuit is  the  Wien  Bridge, 
used  in  most  laboratory 
audio  generators.  The 
purer  the  sine  wave, 
however,  the  longer  these 
oscflfators  take  to  stabilize 


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Fig.  9.  Code  oscillator  using  NE555V  integrated  circuit 


when  B+  Is  applied.  In 
short,  really  pure  sine-wave 
oscillators  are  not  suitable 
for  being  keyed  on  and  off. 

One  solution  to  the 
problem  would  be  to  allow 
a  high-purity  sine-wave 
oscillator  to  run  con- 
tinuously and  then  gate  its 
output  on  and  off.  This  has 
one  problem:  The  key 
closure  and  opening  times 
do  not  coincide  with  the 
zero-crossing  times  of  the 
[asynchronous)  sine  wave. 
Such  asynchronous  gating 
of  the  sine  wave  causes 
transients  to  be  generated 
that  are  very  much  like  the 
''key  clicks"  of  an  im- 
properly operating  trans- 
mitter, so  far  as  the  listener 
is  concerned. 

It  is  possible  to  build  a 
zero-crossing   gate   circuit 


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Fig.  n.  U1  =  LM458N;  U2  =  LM741CN.  Q1   =  2N3641  (pick  individual  transistor  for 
best  noise  output). 


which  delays  turn-on  and 
turn-off  of  the  sine  wave 
until  that  sine  wave  has 
reached  a  zero^crossing 
point.  The  penalty  we  must 
pay  for  the  transient-free, 
pure-sine-wave  gated  audio 
pulse  is  delay.  If  the 
sine  wave  is  1000  Hz,  the 
worst  case  would  be  slight- 
ly less  than  1  ms  delay  at 
the  start  and  1  ms  at  the 
end  of  a  keying  pulse.  Such 
a  1  ms  delay  would  be 
almost  totally  undetectable 
to  the  ear. 

A    circuit,    admittedly 
complex,      which      ac- 
complishes   the    zero- 
crossing  gating  function  is 
shown  in  Fig.  10.  A  Wien 
Bridge  oscillator  is  used  to 
generate  a  pure  sine  wave, 
and    this    is    gated    by    a 
CD4016  analog  gate.  The 
CD4016  is  a  member  of  the 
RCA-CD4000    series    of 
CMOS    logic;    it  functions 
very  well  as  an  analog  gate 
and  is  much  less  expensive 
than  special  ICs  made  for 
this  purpose.  The  same  sine 
wave    is    squared    by    a 
Schmitt  trigger  (LM311)  to 
more    sharply    define    the 
zero  crossings.  The  output 
square  wave  of  the  Schmitt 
trigger  is  differentiated  and 
the    negative    resultant 
spikes  removed  by  a  diode 
(D3).    The    positive   spikes 
are     inverted     by     the 
saturated    amplifier,    Q1, 
which   makes   them   avail- 
able at  CMOS  level  to  the 
logic  ICs.  The  sequence  of 
events  in  the  logic  is  too 
tedious  to  go  through  here; 
you  can  go  to  reference  6 
for    details,    if    you're    in- 
terested. The  net  effect  is 
to    delay    the    opening    of 
gate  U3,  after  application 
of    a    key    pulse,    until    a 
negative-going        zero 
crossing  of  the  sine  wave  oc- 
curs.   The    gate    is    then 
held    open    until    the    key 
pulse  ends,  plus  whatever 
time  It  takes  until  another 
negative-going        zero 
crossing  of  the  sine  wave 
occurs.  The  logic  uses  the 
negative-going  spikes  from 
Q1    as    information    as   to 
when  the  sine  wave  is  mak- 


260 


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259 


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p^  Peatfer  Service— s&e  page  323. 


2i6l 


ing  a  negative-going  zero 
crossing. 

If  you  really  want  to  of- 
fer code  practice  with  as 
close  as  possible  to  of f-t he- 
air  flavor,  and  yet  have  it 
under  the  control  of  your 
code  class  instructor,  one 
additional  complication 
may  be  added.  A  white- 
noise  generator  and  opera- 
tional adder  can  combine 
the  code  signal  and  the 
noise  to  produce  any  (ad- 
justable) signal-to-noise 
ratio  desired.  In  Fig.  11  is 
shown  such  a  noise 
generator  and  operational 
adder.  A  back-biased 
emitter-base  junction  of  a 
transistor  is  used  to 
generate  the  noise  as  it 
goes  into  avalanche.  Two 
operational  amplifiers 
amplify  this  weak  ava- 
lanche noise  by  a  factor  of 
up  to  500.  The  third  op  amp 
is  the  operational  adder, 
which  has  three  combina- 
tional inputs:  noise,  code, 
and  a  third  extra  input.  This 
third  input  could  be  used 


to  input  background  QRM 
from  an  actual  HF  receiver, 
if  you  really  wanted 
realism.  Note  that  each  of 
the  three  inputs  to  the 
operational  adder  has  its 
own  level  control  and  the 
total  combined  signal  level 
may  be  adjusted,  also, 

Fig.  12  shows  a  regulated 
power  supply  and  audio 
output  stage,  suitable  for 
Figs.  10  and  11.  One  of  the 


older  IC  audio  amplifiers  is 
used  because  it  is  easier  to 
use  in  the  low  gain  mode 
than  some  newer  ones, 
which  operate  only  in  the 
fixed  (high)  gain  mode.H 

References 

1,  Editors  and  EnQineers,  Radto 
Handbook,  7th  edition.  1940,  p. 
15, 

2,  Lewis,  A,,  ^^HJnts  and  Kinks, 
Code   Practice   Oscillator" 


QST,  March,  1950,  p,  51 

3.  Sytvania,  Performance 
Tested  Transistor  Circuits, 
1958,  p.  35. 

4.  Flanagan,  R.,  "Hints  and 
Kinks,  FET  Code  Practice  Oscil- 
lator," OST.  July,  1967,  p.  4a 

5.  ARRL,  The  Radio  Amateuf's 
Handbook,  48th  edition,  1971, 

p.  12, 

6.  Oison,  H,,  "Tone-Burst  Gale 
Minimizes  Distortion,*'  Elec- 
tronic Products,  March  19, 
1973,  p.  190. 


on 
HEFirs 

MOTOftOLHl 


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1^ 


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ADJUST 


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Tr  5it 


Fig.  12.  Power  supply  ^nd  audio  amp  for  zero-crossing  code  oscHtatOf  (use  with  Fig.  10  or 
111  U7  =  Motorola  Ma454Q  HEP593,  HEPCe093Q  MC1554C. 


Nei^  Products 


from  page  253 

an  office  conference  table, 
perhaps  the  most  practicai  and 
convenient  of  all  the  many 
items  pressed  Into  service  over 
the  years  I  have  been  an 
amateur,  However,  the  con- 
ference table  is  novw  being 
relegated  to  more  prosaic  duty 
in  my  of  flee- work  room.  The 
reason  for  the  table's  retire- 
ment is  my  new  S-F  Radio  Desk. 

The  S-F  Radio  Desk  was 
ctearty  designed  by  an  amateur 
for  use  by  amateurs.  It  is  a  two- 
tiered  affair  with  pienty  of  room 
for  two  HF  transceivers  and  an 
amplifier,  as  well  as  my  2*meter 
rig,  an  antenna  tuner,  and  a  cou- 
ple of  other  small  accessories 
— without  crowding  or  over- 
loading. The  rear  of  the  bottom 
tier  is  angled  so  that  equipment 
placed  on  it  is  tilted  upward  at 
the  correct  angle  to  provide 
comfortable  viewing  and  ease 
of  operation.  Below  the  main 
desk  surface  is  a  convenient 
shelf  for  holding  small  ac- 
cessories when  not  in  use- 
logs,  Cailbooks,  and  all  the 
other  items  that  otherwise  lend 
to  clutter  up  the  desktop. 

Measuring  39  x  30  x  50  Inch- 


es, the  Radio  Desk  is  available 
in  either  teak  or  walnut  finish, 
or  unfinished  birch  veneer. 
Assembly  is  required.  All  hard- 
ware is  supplied,  and  clear, 
easy-to-follow  illustrated  In- 
structions make  it  simple  to  put 
together.  The  only  unsupplied 
item  I  needed  was  a  bit  of 
Elmer's  glue.  Assembly  went 
without  a  hitch  and  was  com- 
pleted by  the  time  I  had  fin- 
ished two  cups  of  coffee.  The 
finished  desk  is  a  mighty  at- 
tractive addition  to  the  shack 
and  I  wouldn't  hesitate  putting 
it  in  the  living  room  for  every- 
one to  see. 

If  you  could  use  an  operating 
desk  that  will  hold  your  equip- 
ment, improve  your  operating 
efficiency,  and,  at  the  same 
time,  has  sufficient  eye  appeal 
to  satisfy  the  wife  and  rest  of 
the  family,  you  ought  to  be  con- 
sidering the  S'F  Radio  Desk. 
The  desk  is  priced  at  $139.95  in 
teak  or  walnut  finish^  and 
$124.95  in  unfinished  birch. 
Prices  inciude  shipping  by 
UPS.  S-f  Amateur  Radio  Ser* 
vices,  4384  Keystone  Avenue, 
Culver  Cffy  CA  90230;  (21 3h 
837-4B70.    Reader   Service 


number  S33. 

Morgan  W.  Godwin  W4WFL 
Peterborough  NH 

NEWTRONICS  ENTERS  220- 
MHZ  AMATEUR  BAND  WITH 
iNTRODUCTlON  OF  ALL-NEW 
1V4 -METER  7-DBGAlN 
VERTICAL  FIXED-STATION 
ANTENNA 

The  alt-new  Hustler  220-MHz 
vertical  fixed-station  amateur 
antenna,  designated  the  Model 
G7*220,  was  recently  intro- 
duced  by  New-Tronics  Corpora- 


220  MHt 
Vertical  Anteniu 


rft. 


New'Tronics'  new  220-MHz  ver- 
tical Mustier  antenna,  the 
Model  G  7-220. 


tion  of  Brookpark,  Ohio.  The 
G7-220  marks  New-Tronics*  en* 
try  into  the  now-popular  220 
MHz  band  and  complements 
their  existing  base  and  mobile 
amateur  antenna  line.  The 
superior  7-dB  gain  of  the  anten- 
na, fof  both  transmitting  and 
receiving,  makes  it  one  of  the 
most  powerful  omnidirectional 
1%  meter  antennas  available. 
The  ail-new  rugged  design  of 
the  Hustler  07-220  antenna 
keeps  the  signal  radiation  pat< 
tern  at  the  lowest  possible 
angle  to  the  horizon,  for  max- 
imum efficiency  and  longest 
range. 

The  Model  67-220  has  an  swr 
of  1.5:1  across  its  entire  5-MHz 
bandwidth,  with  swr  at  reso- 
nance of  1.2:1  at  the  antenna. 
The  radiating  elements  of  the 
Hustler  07-220  are  dc-ground- 
ed  for  lightning  protection,  and 
the  antenna  has  a  SOOhm  base 
impedance. 

This  new  Hustler  220-MHz 
vertical  combines  the  latest 
antenna  technology  and  the 
best  available  corrosion- 
resistant  materials  for  extra- 
long  life.  Only  Hustler  uses  all 
stainless  steel  hardware  in 
amateur  and  professional  prod- 
ucts. Each  component  is  pre- 
cisely built  for  quick  and  easy 
assembly. 

Continued  oft  f^age  272 


262 


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SEC  GATE  AVAILABLE  ACCURACY  ±.001%.  UTILIZES  lO^MHl  CRYSTAL  b 
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COMPLETE    KIT , .....,,,., ^i4<T,, t12» 

HAL'^OOA  ZOIGIT  COUNTER  WITH  FREQUENCY  RANGE  OF  ZERO  TO  300 
MHz  FEATURES  TWO  INPUTS:  ONE  FOR  LOW  FREQUENCY  AND  ONE  FOR 
HJGH  FREQUENCY;  AUTOMATtCZERO  SUPPRESSION  TIME  QASE  IS  l  0  SEC 
OH  1  SEC  GATE  WITH  OPTIONAL  10  SEC  GATE  AVAILABLE  ACCURACY 
*  001%.  UTILIZES  10-MHi  CRYSTAL  5  PPM 

COMPLETE    KIT.. ,.,,,, ,,...>«<r.... ,.........,,,.,..... SIM 

HAL'SOA  B  DIGIT  COUNTER  WITH  FREQUENCY  RANGE  OF  ZERO  TO  30 
MHz  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  ±001%.  UTlLiZES  lOMHz 
CRYSTAL  5  PPM.  ^ 

COMPLETE    KIT, .,..„ >i*^ ■"- **'0S 

ATIENTION  RADIO  CLUBS  For  club  or  group  projecrs,  request  FREE  infor- 
mation a&out  Qur  DISCOUNTS  on  any  of  1  tie  HALTRONIX  kits.  Discounts  range 
ffom  10-25%,  depending  upon  the  quantity  needed. 

We  are  experienced  in  supplying  kfts  m  volume  quani^ties  to  schools. 
Laboratones.  ClutKS.  and  comrTx>n-mtete3l  groups.  Nobody  beat^  HAL^TRONIX 
quality  and  ptice.  Just  tty  us  arid  see  for  vourself . 

IlCl?       HALTRONIX 

DELUXE  12^BUTTON  TOUCHTONE  ENCODER  KIT  utilizing  irte  new  ICM  720& 
ctilp.  Pfovides  both  visual  and  AUDIO  indicaiions'  Comes  wMh  its  own  t*o 
tone  arroditzed  alummum  cabmet.  Measures  only  2  3i'4  x  3  3/4'V  Complete  with 
Touch-Tone  paa.  tKiard.  cfy£taJ«  chip  and  all  necessary  cofriponents  to  firkish 
the  kit. 

For  those  who  wish  to  mour^l  the  encoder  in  a  handheld  unit,  the  PC  board 

measures  Only  9/1 B"  ^  1  3/4".  This  partial  hit  with  PC  board,  crystal,  chip  and 

compcinenls 

PRICED  AT....... - S14.95 

PRE-SCALER  KITS 

HAL  300  PRE .$19.95 

fPre-d rilled  GIO  board  and  ^11  compor>ents]i 

HAL  300  A/PftE. , . , , .  „ .  $24.95 

{Same  as  atjove  writi  preamp) 

(Pffrdhlled  GTO  board  and  all  componenls) 

HAL  600  A  PRE. , $39.95 

(Same  as  above  but  with  preamp) 


SfECIAL  OFIER— While  they  Ust 

FND'70  Common  cathode  readouts  direct  replacement  for 
the  FND-359  same  pin-out. 

10  units  {.40«)—     10/     4.00 

100  units  ^35e)—   100/  35.00 

500  units  (.300—  500/150.00 

1000  units  (.25(1;}— 1000/250.00 


HAtOiD  C    NOWLAND 
WBZKH 


Hal-Tronix 

P.O.  BOX  1101 

SOUTHGATE,  MICH.  48195 

PHONE  (31 3J2&5' 1782 


i^H24 


f^  Readm  Service— see  page  323. 


263 


S-r  Amaleur  Rodio  /brvice/ 

(213)837-4870 
4384  KEYSTONE  AVE..  CULVER  CITY.  CA.  90230 


the  W6TOG*  ^^'^ 

RECEIVER  MODIFICATION  KITS 

INCREASE  SELECTTVIP/  •  [MPROVE  SENSITIVIW 

LOWER  INTERNAL  NOISE 

IMPROVE  NOfSE  BLANKER  OPERATION 

COMBAT  BLOCKING  FROM  LOCAL  SIGNALS 

TS-&20  KIT $27,50  FT- 101  SERIES  KPT  . .    $32.50 

TS-520S  KJT 32.50         FH-101  SERIES  KJT . . .    34.50 

TS-820  &  820S  KTT         34  SO  FT ^301  SERIES  KIT         34.50 

R-599  A/D  KIT  .  27,50  FT~901  SERIES  KIT . . ,    34,50 

EXPUOT  INSmUCnONS  MAKE  MODtFICATlON  A  ONCH 


IT'S  MAGIC. . . 
IT'S  "MAGICOM" 

PROCESSOR  MODIFICATION  KIT 

IMPROVES  AUDIO  PUNCH 
IMPROVES  PROCESSED  SPEECH  QUALITY 

Converts  TS'820  /  820S  speech  processor  from  RF 

compressor  to  RF  dipper  $27.50 

RF  speech  pmcessor  for  TS-520  /  520S  $4Z50 

The  "MAGICOM"  RF  processor  module  provides  up  to 

6dB  increase  in  output  with  smooth,  dean, 

non-distorted  audio  and  more  penetration  for  those 

pile-ups. 

ENDORSED  BYAVSTOG  AND  BIG  GUN  T>Xmm  WORLD  WIDE 

the  W6TOG  * 

INTERNAL  ELECTRONIC  KEYER 

FOR  ALL  AMATEUR  TRANSMITTERS  OR 
TRAl^SCEIVERS  USING  GRID  BLOCK  KEYING 

•  No  holes  mounting  with  TS-S20  Series 

•  Mounting  options  forTS-520,  TS-520S,  FT-101 
Series,  TR4  Series,  T4X  Series,  T-599  Series  and 
325  Series. 

•  C-MOS  DESIGN  —  E)ot  and  dash  memoiy  —  fuH 
iambic  or  manual  operation. 

•  Simple  installation        v[^  $49.50 

THE  S-F  REJEKTOR 

FILTER 

AN  II^EGRATED  CIRCUIT 

ACTIVE  BANDPASS  FILTER 

FOR  PROCESSED  RECEIVER  AUDIO 

•  Separate  active  filter  demente 

for  CW  and  SSB  audio  output  stage 

•  8  ohm  input  and  output  impedance 

•  Headp hone  jac k  for  con ve nience 

•  ON  CW:  from  500  hz  to  100  hz.  variable 

•  ON  SSB:  2  Khz  fixed  bandwidth 

•  Rej^:ts  unwanted  signal  better  than  60  dB 

•  Designed  for  today's  transceivers 

or  yesterday' s  older  equipment      $49 .  50 


HZ  EuniioniQ,  IK. 


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We  accept 

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All  prices  po«iitpaid  -  in  C^lif.  add  6%  »alcs  tax  -  MaitCTchai^  &  Visa  accepted 

fc^    SATTSFACnON  GUARANTEED  OR  MONEY  REFUNDED    J 


A'V 


264 


p^  pB^dBr  Service— see  pags  323. 


the  microcomputer-controlled 
appointment  clock 


—  IMOTAKIT 

Regular  Price  S  79.95 
Introductory  Offer  by 

Hal-Tronix 

only  $69.95 


FEATURES: 


•  Sleek   modern   styling    to   complement   any 
home  or  office  decor, 

•  Tells  the  time, 

•  Tells  the  date  and  year, 

•  Op-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  appomtmenls  up  to  one  year. 

•  Dimmer  switch  for  display^ 

•  /viemory  will  hold  up  to  30  appointments, 

•  Lithium  power  cell  to  retain  memory  during 
power  outage. 

•  Appointments  entered  out  of  chronological 
order  wiii  be  stored  in  chronological  order* 

•  Colon  flashes  once  each  second. 

•  A.M./P,M.  indicator, 

•  Plugs  into  any  wall  outlet, 

•  Easy  to  read  vacuum  fluorescent  display, 

•  Extremely  accyrate  quartz  crystal  clock, 

EFFICfpNT.  REMARKABLE. 

TimeTrac  sold  and  distributed  by  HAL-TROC^IX,   Deajtfs  w^lc^me. 

Send  1 5<t  stomp  or  S.A.S.E.  for  information  and  fSyef  on  other 
HAL-TRONIX  products.  To  order  by  phone?  1-310-2d5-1762. 


'MAL" 


HAiOtD  C    NOWIAHD 

wezxH 


Hal-Tronix 

P,0,  DoK  H01 
Southgate,  Ml  46195 


^H24 


SHIPPiMG 
IHFOKMATiON* 


ORDEfti  OVER  i  1  5.00  WILL  DE  SHIPPED  POSTPAID  EXCEPT 
ON  ITEMS  WHERE  ADDITIONAL  CHARGED  ARE  REQUESTED. 
ON  ORDERS  LESS  THAN  SI  5.00  PLEAS£  INCLUDE  ADDITION- 
AL »  LOO  FOR  HANDLING  AND  MAILING  CHARGES. 


TERMINAL  UNIT 


Connsct  to  your  receiver  speaker,  transmitter 
microphone  jack,  and  teletype  machine  and  you^re  on 
the  air.  State  of  the  art  design  features  make  the 
TU-170  Ideal  for  HF  and  VHF  autostat  operation. 


Proved  170  Hz  shift  actpve 
filter  demodulator 

Lighted  tuning  fiieter  for 
easy  tuning 

Current  regulated  loop  keyer 
&.  power  supply 

Autostat  with  threshold 
control  and  solid  state  relay 


,  Stable  audio  frequency  shfft 
osciNator  prodifGes  ph^se 
coherent  sine  wave  tones 

TTL  compalfble  mputs  and 
outputs  for  auxilliary 
equipnnent 

.   High  levei  output  ioT  scope 

tuning 

TU-170  TU-170 

Kit       149.95    Wired     219.95 


Fhsher  productB  .  .  .  Me  cr/f/cs  cAo/ce/ 

B  FieSBEl  MRP.  ^ 

P-O.  Box  976,  Topeka,  Kansas  66601     (913)  234-0198 


N888 

HAIMD-HELD 

HF/SSB 


D  10  Watts  PEP 

D  2-9  MHZ 

D  USB/LSB 

D  Rechargeable  batteries 

D  Accessories 

The  NSaS  permits  long 
range  communications  in 
difficult  and  adverse 
locations,  thereby  offering 
important  communication 
advantages  over  AM  and 
FM. 

The  smallest  complete 
personal  H.F,  SSB 
communication  system 
available. 


1^ 


NORTHERN  RADIO  COMPANY 

COMMUNICATION  PRODUCTS 

T4g75NORTHEAST40TH.f^eDMOWD.WA3KINGtON9B052,lJSA 
^2QQ^  SB3-7700  TELEX"  32-1160,  CABLE  ADDRESS'  -NOFlLECTfl AD 


p^  F^eader  Service— see  psge  323, 


265 


BARKER  & 
WILLIAMSON,  INC. 


POAviAi    oxMixr^uirc  am  n  A^r^CQQr\D  I  PQ 

PRICE 

V   1     1    ^^  1     1   L 

and  RF  swi 
Outputs 

tching 

37& 

18.95 

6 

PROTAX  Sk/Vitch   Gfc^uixJsall  except  «tec!eri« 

37€ 

18.96 

5 

PHOT  AX  switch.  Grsiuridsau  excepl  aclef:ied 
ouipuT  CifCyit.  Suflb  !S-^wiTi:n  PO.SiTiQft  grounds 

5G0A 

14,00 

5 

5S0A.2 

12.50 

2 

S51A    ^ 

17.50 

2 

special  2-pole,  2-pH3sitian  swrTch  usftd  to 
swiich  any  RF  devn:*  <n  of  oui  ot  series. 

S56 

.95 

-■ 

SfacKBl  oniv.  tor  wall  mounTii^ot  f4Jdi^> 
g  onnec  tor  s w  1 1  ches. 

590 

1  7.9S 

5 

59QG 

17.95 

5 

Griiurtdi  i^if  except  selected  -ouTput  cifcu^t. 

S92 

1^.50 

2 

505 

18.50 

6 

Grounds  aH  e^cepi  stiJ4i<:ie0  output  circuii . 

COAXIAL  SWITCHES  AND 
ACCESSORI  ES  for  antenna  selec- 
tion and  RF  svuitching.  These 
high^qualitv  switches  have  set  the 
standard  for  the  Industry  for 
years.  Ceramic  switches  with  sil- 
ver alloy  contacts  and  silver- 
plated  conductors  give  unmatched 
performance  and  reliability  from 
audio  frequencies  to  150  MHz. 
BSiW     coaxial     switches     are     de- 


signed for  use  with  52-  to  7 5- ohm 
non-reactive  loads,  and  are  power 
rated  at  1000  watts  AM,  2000 
watts  SSB  Connectors  are  UHF 
type.  Insertion  loss  is  negligible, 
and  VSWR  is  less  than  1.2:1  up  to 
150  MHz.  Crosstalk  (me&sured  at 
30  MHz)  is  45  dB  between  adja- 
cent outlets  and  -60  dB  between 
alternate  outlets. 


McMkf  37ft 


HiMWBHa 


-•■v- 
*••«•. 


MhIm  Svo 


MhMUOA-2 


IVfaiM5e2 


kA250lH  Kit    . 

PA4010H  Kit  . 
PASO/25  Kit.  . 
PA144/IS  Kit  . 


PA  144/2 5  Kit  . 
PA220/1S  Kit  . 
PA432/10  Kie  . 

PA14O/10W/T 
PA  140/30  W/T 


2  mtr  power  amp -kit  lwin-2Sw 

out  wiih  *olid  stale  switching, 

case,  connectors-   .   „  .  h  .  ^  *  ,  *         64,95 

2  nilt  power  amp-lOw  in— 40w 

out— relay  svvitching   ........        64.95 

6  mtr  power  artip,  Iw  in*  25 w  out, 

1*£S  case,  connettorji  &..  switching         S4.9S 

2  mtr  power  amp-lwin— iSw 

out— less  case^  connectors  and 

switching ,  .  .  .  ,         44.95 

same  as  PA144/1S  kit  but  2Sw  .  54.9 S 
similar  to  PA144/1  S  for  220  M Hi  44/95 
power  amp-siTniiar  to  PAj44/iS 
except  10wand432  MHz  ...  S4,^S 
lOw  in-l40w  out-2  mtr  amp  .  219.95 
30w  in-l40w  out— 2  mtr  amp    .       189.95 


POWER  AMPLIFIERS 


Blue  Line 


Model 

BLC  10/70 
BLC2/70 
BLG  10/150 
BLC  30/150 
BLD  2/&0 
BLD  10/60 
BLD  10/120 
BLE  1  0/40 
BLE  2/40 
BLE  30/SO 
BLE  10/80 


Rl  power  amp:;  wired  <t  iested4  emiH^ion  — 
L'W-LM-SSB/AM 

Power  Pcjwtir 

BAND  I"P"t         Oyipul 


144  MHz 

tow 

70W 

La'*.^? 

144  MHx 

2W 

70W 

169.95 

144  MHt 

Km 

I50W 

2  5  9.9  S 

144  MHz 

30W 

\  50W 

23  9.95 

220  MH2 

2W 

60W 

164. 95 

230  MHi 

low 

60W 

IS9,95 

220  MHz 

lOW 

120W 

25  9  95 

420MH1E 

lOW 

40W 

179,95 

420  MHz 

2W 

40W 

179,95 

420  MHz 

30W 

eow 

259.95 

420  MHz 

low 

sow 

289.95 

POWER  SUPPLIES 


PSiSCKJt 


PS15CW/T.   , 
KS25M  Kit,  . 


PS  25M  W/T, 
PS3A  Kit     .  . 


1  5  amp-  1 2  vf>lt  regulated  power  Sup- 
ply w/cAse,  w/fold-back  current  limit- 
lit E  ^nd  overvoltagt^  protect toa   .   .      94,95 
same  as  above —wjrt;! tl  ^  tested,  .  .    124.95 
25  amp— 12  volt  regulated  power  sup- 
ply w/c^se,  w /fold -hack  current  limit- 
ing and  ovp^  with  meter  .►,,..    154^95 
^ninie  as  above— wired  &  testi^d.  -  .    17  9.95 

adds  over  voltage  protection  to  y<3ur 
power  suppllL'S.  15  VnC   max.      .   ,       12.95 
1  2  volt '  poller  supply  regulator  card 
with  fold-back  turirent  limiting  ,  .       10.95 


PS3012  W/T 


new  dommercial  duty  30  amp  12  VD€. 
regulated  power  supply  w/case, 
w/fald-back  current  limitini^and 
overvtiltage  prfjtection      ,,,..,    249.95 


f  engineering 


The  most  convenient  way  to  order!  Just  call  our  Credit  Card  Order  Department  9AM'9PM  at  (617) 
395-8280,  Your  order  will  be  processed  immediately— you'll  be  receiving  it  even  more  quickly  than 
if  you'd  sent  it  by  mail.  Any  way  you  look  at  it,  our  same-day  service  plus  our  special  telephone 
credit  card  service  equal  the  fastest  way  to  shop  by  mail!  (Sorry— we  can't  accept  collect  calls,) 
Helpful  hint:  To  make  your  order  as  clear  as  possible,  fill  in  ail  Information  on  this  order  form,  then 
read  it  when  you  call. 


VfSA 


Prices  FOB  Medford  MA. 
MA  residents  add  5%  sales 
tax. 

Minimum  $3,00  for 
shipping  &  handling 
on   ALL   ORDERS. 


Name 


Call 


Address 
City 


State 


^  Zip 


Order: 


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PRICES  SUBJECT  TO  CHANGE  WITHOUT  NOTICE 


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PLEASE  -  No  Cash  Or  C.O.D.s! 


Radio  Electronics      v^ia 

209  Mystic  Avenue 
Medford  MA  02155 
(617)  395-8280 

Toll  free: 
[800]  225-44SE 

OPEN  DAILY  9-9 
SATURDAY  9-6 


Tufts  Radio  Electronics  •  (6T7J  395-8280 

TC-1 


THOMSON  CSF 


NPC 


ELECTRONICS 


MODEL 
12V4 
102 
107 

loan 


NET  PRICE 
$24.95 


$39.gs 


104R 

lOaRM 
109R 


$49,05 
179.35 

S149.95 


MODEL  103R 


AUTOPATCH  -  Ready  to  gol 


aODEL  108RM 


r^  iwtf^  M|r  ipi  ^antf 


^     r  ^f    fii 


J 


-^iflinAa:  HT  lifflll  fiWHHHMii  tli  ^if  wii   W  iai« 

■of  oiTBit  DvtFiiiBi,  Hvmitl^  iild  Pvinti!  Dron^tHn 
lwBp«f«nf  nahlvHjHiiiMviilMMr  m|Mh  mfta 

innHittt  bMdi  peMf  nnn  ttm  iviMo  mtf  mmom  of 

Rii'Tl'rihl'CDnm'iHMia  I^Anlp 

euimnH  imil  HAmp 


15*   ■  woe 


lilV 


lis 
121 


ilCvTJtiiMOC 


#'*  tMM*^  i*»in  i&t 


%kSO  AV4ILAKLC  AS  MODEL  tSB^tA 
4IITHQUT  MCTiq  '!NlD  OwERVOl-TAGf 
*nOTECTlOH 


MODEL  10411 

n«(uia»d. 
$«l<4  Sl«ta   Ouai 

115  *^  AC  ■  11 »  f«l 


•■  T»W  J(X 


tin    Tvnc 

i  W  MM} 


frnp^mf  Mli^fnit  'd4n 


MODEL  107 


ft.Jt' 


HilUM 


ill 


Cv**rtiiifiisuwa 


MODEL  12Ua 

NPC  1.7&  Amp 

PiQiNBf  Supply 

3  Amp  Mm 

H4  lis  «D<t5  AC  b|  il  HfAl 

DC  4dMtir  &y«ied  t«f  iiwii 

lAcJ^ing  l-Hicfc  fl#iw  avglv 


A  Comprete  Autopatch  facittty  that  requires  ortly  a  repeater 
and  a  telephone  line.  Features  include  sir>e^e-djgi|  access/ 
disconnect,  direct  dialing  from  mobde  or  hand-held  radios* 
adjustable  amplifiers  for  transmitter  and  telephone  audits,  and 
tone-burst  transponder  for  acknowl^edgement  of  patch  dis- 
connect. 

RAP-200   P.   C.    Card  S1§9,S0 

RAP-2D0R   Rack   Mount  |249.50 


ADDON 
POWER! 


Nighefl  qLiaUTv,  AmefJcan-rrtadfl  'brand ' 
iraflSiSlOiS  are  luliy  prDtecteH  fOf  VSWR. 
shofi  and  overload,  rei^erse  poiirrfy 
Highly  effective  heat  smiof^g  as&uttf  $  inr>g 
hie,  rehfltfe  perfofmajice  84Ck  yia<liied 
comaners  exdusive  klM  extruiion*, 
h«¥e  aewn,  full  lengm  lim  on 
both  *Mlci' 


KLM  RF  Power  AmpUtiers 


or  ridifl  jm 


■iv  r  fH]  >  c^'  iw:i  ■  |ih-  ii>f 


IVIODB.103R 


Pbpi*^  Supply 
Soiid  Snt*  Duvt 


jmvti  11^  vDltR  AC  11}  tl  E  vQln  DC  t  ZOO  milliuOUt  hjntm  7.E> 
npj  [;aiiiinLiiiit!i  ind  4  aitip^  mji  IdtaEly  sui'ted  lor  &j»|)li(;iit|(Hkt 
tiw&  [»  hrfudnd  DC  KabNlily  art  impodanft  sudU  as  Cfi  IraninitupiKi, 
mM  Hiam  ridiD  trjubmlltoi.  tind  hi{h  qualify  e^i^t-t^icN  cai  iilimi. 
IF1  ilu  be  usKi  3D  lriEi>e  cioiKi  1?  MfHl  C3f  bactwies 


•■  A  Simple,  add-on-immediaiely 
RF  ampiiiiec 

•  Merely  coax-connect  ampflHer 
beiween  antenna  and  transceiver. 

•  No  tuning'  Efficient  strip-lme 
broad  band  design. 

•  Automatic!  Internal  RF-sensor- 
cont roiled  relay  connects  amplifier 
w/ bene ver  transmitter  is  switched  on. 


Manuat,  renroie-posiiian  switching 
IS  optional 

•  Models  for  6.2.1^^4  meters.  70CM 
amateur  bands  plus  MARS  coverage 

•  Two  types:  Class  C  for  FM.'CW, 
Linear  (or  SSB/AM/FM/CW. 

•  Negligtbte  insertion  loss  on  receive 

•  AmefEcan  made  by  KLM, 


New  Model 

List  Price 

PA  2  25B 

$  69.95 

PA  4-70BC 

189.95 

PA4-70BL 

189.95 

PA  15reOBC 

164.95 

PA15^40BL 

109.95 

PA45-T20BC 

2D9.95 

PA  15^  SOB  L 

1  79.95 

PA  4-40C 

169.95 

PA16-160BL 

250.95 

PAT5^35CL 

154.95 

PA45-140BL 

219.95 

PAIS^nOCL 

279.95 

i'tHii'>*~ifwiii**' 


Ti'PHIAL 

1 3.6    I  2  VtiC 
MffiV 

ti 
it)l 


13  Hi  »  JVIK 

Umv 

5  mV  NMft 


MODEL  102 

WrC  2  S  *rwp 
PQin«f  Supply- 

4  Arfip  M*ii.  Solid  SlBTI 

FiilKilCHls  silrt^tly  11^  CQiiv«r1 
Nifj  11^  vdU  AC  10  l^.vnlla 

DC  S.Sanips  cHUiniwtK,  4  irnpi  mti   Eiifibl«s  anymie  id  flniiiy  CB 

wMo,  cv  B'tach.  oflrbdov.  cui^nn  Ujh!  pliiyp  or  car  radio  m  a  hanu 

fli  tfNIcse 

CenmuDua,  Cuirenllf  ullltiDiW^] 

Aulpul  VDlts^e  1.N0  Load! 

Ouipuj  Vonag*  {Fun  vjomAi 

Ripfrtv  trull  LHdt 
Short  C*ct*r 


2  5  Amp 
lEVmu 
4^J  Vnnn 
SjOKMuF 


i'plj  m*l»-  pi)  ■  *V  (Of 


■  ttn 


slinky 


SLINKY!  S43,95  Kit  A  LOT  oX  antenna 
in  a  LITTLE  spate  Now  SflJnky^Uipole* 
with  hoJicaC  Loading  radiataK  a  gooci 
'fiJBnali  at  ; /10  wafvelength  longf 


>NIW*(  w#  lit^.^lQ 


NEW 

^Continuaut  tuning  1.8—30  IVlHz 

*  Forward  reading  relattve  output 
pouu@r  meter 

►  300  watt  power  capabrlity 

*  Built-lr^  drtcQpsuiated  balun 

*  Mobile  mounting  bracket 


Ceramic  Rotarv  Switch  l2-|>o^- 

tion 

Capacitor  spacing  1  000  volts 
Tapped  loroid  inductor 
Anter>nd  Inputs^ 

a.  Coax  unbalanced  50239 

b.  Random  wire 

c.  Balanced     feedline     75 — 660 
Ohm 

S%'*  w.  X  2%''  h.  X  6"  d. 

All    metal   black    wrinkle   finish 

cabinet 

Weightr  273  pounds 

Price:  $79.95 


mrL 


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This  olectricaMy  smalt  SO/75,  40 
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any  length  from  24  to  70  ft.  •  no 
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*  portable  ~  erects  &  stores  in 
minutes  •  small  enough  to  f»t  in 
attic  or  apt.  •  full  fegal  power  • 
low  SWR  over  complete  80/75, 
40  8t  20  meter  bands  •  much 
lower  atmospheric  noise  pick  up 
than  a  vertical  &  needs  no  radtals 

•  kit  inch  a  pr,  of  speciaMy  made 
4*'  dia.  bv  4"  long  coils,  con 
tainirm  335  ft,  of  radiating  con- 
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COMMUNICATIONS    WITH   ATB  34 


Hy^Giin  REEL  TAPE  PORTABLE  DIPOLE 
for  10  tiiru  80  Meters  Model  18TD 

Ikt  most  partible  high  perfofmajice  dipoJa  ever... 


^^^^stfi 


Tb?  Model  IHTD  i*  uivtnmtmoMMj  Ifae  maA  fbutpffxirhii^h  pcf^irmaticp  pcirtnble 
lioubtet  antesna  •yiunn  *w  lirtthumi  h  tm  prtriiii/<n  iiivaluAbltf  in  proviiiini^ 
TvU«b}e  o^miniuiiicAlkiJfiti  in  vitaJ  mililAf^  uidtiifQiDrrvtal'*(3pLicatii3(ii^  thmogh- 
cvi  the  world  T««  fUiolnv  jtoirl  tapes,  calibrai«d  in  mmtm*„  extendi  fhuo.  «tllter 
t»Ae  id  tlie  mam  bounnff  up  to  a  EotaJ  dialaDCtt  lof  132  f««t  iw  3.S  at  <Mptf*tivn 
J-'i  It,  l*^f*li*  ei  fQtjrprapylcnr  lupc  Mlaciwd  L^  mcb  Lupr  prmuts  instalUtK^ 
to  fHtes,  tRci.  buildiiaif*  •  hcsc^  «r  is  awaiiablr  Ibr  Fomunc  a tioubki  aniiHiaa  tefUgm 
'-^    — vitd  m  tIui  Ikifli  miyci  hmaing  u  >  frequanc^  Is  length  nnnrcfalfWi  dHift 

^t«d  tjs  Rirtar  ■!<— irenaiiti  on  tlir  tapn     raaltaa  nntaJlatioQ  btijraai.  Faidi  wiili 
SI  oiub  OE«K.  Di;hlif«n  outwaivlran:  perfkvniaiKC  ML  «  portabte  er  pensanait  xEiiialliiiion 
MeosufEi  lpKSHk:2  IftfKiTB  rrUsOed.      Wt.,  4.1  Ibi. 
Ordef  No.  22&  Prio  59436 


^IhjHlAffi 


ALL  NEW 
3-BAND, 
2  ELEMENT 
HY-QUAD 


l«  *v^  full 


a  Nibf*  lit  irit«f  qMAiiUufcli* 

a  H^  Mr«B^,  !■*  mpid  liad 

f  W  H»  g^rf  fffWH  ItT^^BA  mifen  j«  wrbt*  4|«4i  vtma/ktt* 

Ini.  ri i  iht  'HAf  iftM  lhi>l  ■  «Ha|ltlr   Tlwir  m  nerttt*^ 

ivvvMllt.  It  «&  wmfiidi-  il«ufiKil  fev  tht<  tt  o^mvaima  iD  fd  Itv  pir»itMrif 

■Mdmnlilf'  f  r«l  urri  iiilirKnl  ■«  quvdi 

Hit  M\  •luiTHnHrn  ttrw^wc  titt-x-  up'  tht  fMffr  f*t4  linr  iM^d  dpiAnmd  i4i*vf 

Hv  Ciiri  «  '14  It*   H^-Qiuid  W'tn  uii1ilt:iill  ollm  qUiAibmuM  if%  mfwic*ir4 

Lu  du  ^UlJ  ikVJ  Tfac  H\-0'liail  l»  M*>«<.  irL  Mt|I4fd(ll,  ll  l^rURl^EtE.  h\  lllF  tlllt 
l]iiud  III  h|w  Fvr;|>lliiii|r  %pT».|lerih>ir  |h  uk^m  l^fVJII  ttfill'tl^ 'If^fii^*' J^l^Ol 
wiil|(  t:^4r'nkl4^  jnnuNl urni  /  iri-bnnd  !  ekn'Ki'ili  ^Oitiilruti'licjiri  v^iiIl  incllviiliiitLy 
fv^fntiUfd  ffleMinnH  *mi  rw  lolrrjii'lUjM  /  Hir-Ut44il  iKujuifti  nulir  "Tf  I'^il  I't^^ 
Em  kII  Hirrp  bandi  /  indtrtduith  4iin«d  larnnvi  nmlcht^i  an  carh  t^iitd  wtlh 
H^  (iilji  ch^'lutlvf  trrten  Iced  /  lull  <*fw*w  vl^rnfni  Jwpi  Eequicc  tiu  tunini 
hImIii.  Iiiiipti  kijdtnf  coih  or  btlupu  /  h«a^r  Aui}  (net tunic bIi  icnniifucl ton  d| 
tliiti^t  twiftil  aiupuiiiMiti  tutHttg  i4kil  liic  IriniKJ  M^^id^r-iit^bufHifti  c'Eiitipt  / 
ftllt  Iwailp  KuiT  uni*vrul  biutm  Ki  rnn^i  ^biin[7  th«|  )||i«  f4iil  rnimnlii^n  tnt 
HMt  l^i"  14  lli'^'  m  tlaaTnrEcr  ?  tIttRnAUm  tiriad»id  Mrg>ff.  Ycm  cin  oprn  iMl 
Lliif*  iIh  faaiKlK  wtih  I  mi  BRicnmi.  ttfm'UfupirmwKr  ika  rbnti  ol  rtd  Dl^t 

Ordcrr  No  ^44  f¥>a:  S?T9SS 

S^CtflCATIDMS 


HY  GAIN  S  INCOMPARABLE 

HY-TOWER 

FOR  80  THRU  10  METERS 


A^ 


Arn^Tt^r  Hjdk)  S^rfJ^eimt 


1~<Z> 


-u 


N*t, 


Modi-I  18HT 

•  QuUtaiidme  Omnj-Dif*ctiririal  Performnnc^e 
^Automatic  Bjind  Switching 

•  |nsiiili!£  on  4  sq.  ft,  of  real  estate 
S Completely  S«lf^upparLln^ 

By  any  standard  of  measurements  the  Hy*Tower  Is  unques* 
tlonabb'  the  finest  multi-band  vertieal  antenna  system  on  the 
market  today.  Viriuiilly  indestructible,  the  Model  18HT 
featuTesi  automatic  band  selection  on  80  thru  10  meters 
through  Ihe  use  of  a  unique  stub  decouplinc  system  M^htch 
effectively  isolates  vanous  sections  of  the  antenna  so  that  ait 
electrical  U  wavelength  (or  odd  multiple  of  a  1%  wavelength) 
exisli  <in  all  bands.  Fed  with  52  ohin  coaK*  it  takes  maximum 
lefal  power  ,  .  .  deUve»  outsiandine  perforinance  on  all 
bands.  With  the  addition  of  a  base  loading  et^il,  it  also  delivers 
oui3«tanding  performance  on  160  metersi.  Structurally,  the 
Mnde)  ISHT  is  built  to  last  a  lifetime.  Ru^fied  hot-dipped 
galvanir.ed  24  ft.  tower  requires  no  guyed  supports.  Top 
mft*t,  which  extends  to  a  height  of  50  Ft.,  i»  6061 5T6  tapers 
aluminum.  All  hardware  i»  iridite  treated  to  MIL  specs.  If 
youW  looking  for  thi'  epitome  in  vertical  ttnie»na  systems. 
youMl  wwit  Hy-Towt^r,  Shpg.  Wt.,  96.7  lbs.  Order  No.  182, 
Price:  $279.95 

NFW  Special  hinged  bafie  assembly  on  Model  l&HT  allows 
complete  assembly  of  antenna  at  gtuund  level  ,  .  ,  peimtts 
easy     raising    and     lowering    of    the    antenna. 


MULTI-BAND  H  Y-Q  TRAP  DOUBLETS 
Hy-Q  Traps 

■  Install  Horizontally  or  as  Inverted  V 
B  Super-Strength  Aluminum  Oad  Wire 

■  Weaihrrpruuf  Center  and  End  Insulators 

Installed  horizontally  or  as  an  inverted  V,  Hy-Gain  dnubleis  with 
Hy-Q  traps  deliver  true  half  wavelength  perfurmance  on  every 
design  frequency.  Matrhed  traps*  individually  pretuned  for  each 
band  feature  large  diameter  coils  that  develop  an  exceptionallv 
fav^irable  L/C  ratio  and  very  iugh  Q  perform,anre.  MechantciUy 
iiUperior  solid  aluminum  trap  housings  prtjvide  rnaa&imum  protec- 
tion and  support  to  the  loading  coil.  Fed  with  52  ohm  coa?i« 
Hy^Gain  doublets  employ  super-strengih  aluminum  clad  single 
strand  steel  wire  elements  that  defy  deteriutatiun  from  salt  wattr 
and  smoke  .  .  .  will  nat  stretch  ,  .  .  withstand  humcane-hke 
wmd»-  SWR  less  than  1.5:1  on  all  band».  Strong,  lightweighln, 
weatherprool  center  insulators  are  molded  from  high  i^npact 
ryolac.  Hardware  is  indate  treated  to  MIL  specs.  Heavily  serrated 
T-inch  r'nd  insulators  molded  from  high  impart  cyrolac  incrcjiJte 
leakage  path  to  approKimately  12  inches. 

MOUt:L  2BDQ  for  40  and  ftO  meters;.   ItJO'  lOi/i"  overall.  Takes 

maximum  legal  power-  Shpg.  Wt.*  7-5  lbs  $49*95 

Order  Mo.  380 

MODEL  5BDQ  for  10,    15,   20.  40   and   80   meters.  94'  overall. 

Takes  maximum  power.  Shpg.  Wt.«  12.2  Ibii.  $79.95 

Order  No.  3ft3 


Meet  the 
SuperTuner 


fKW  Model  Sf29.50 


Tha  DwnTion  Sugmi  Tunef  njnei  vMryrfhinii  fittm  t^-lD  meierK  Whtthtr  ymi  haw 
balArtCad  tiiiiipi,  CQiix  i^sbl^.  ranclOTii  m  lt>ng  4>yite,  [be  Supei  Tunet  v\hI\  msiTah  thff  nnt^nina 
impvdartcii  to  your  iranimittat.  All  DtinTrnn  tunef s  give  vc^u  mrtKinnjiii  paw»r  uimsfer 
Irarr  ytsur  iraMfmrttifr  to  your  snlfliinu,  anil  iln't  \h»l  where  it  rqiiiriy  c&untl? 


JItUi 


^  Model  TA-33  Jr,,  3  elements, 
10.1  dB  forward  gain  (over  iso- 
tropic source)  —  $197.00 
•  Model  MPK3,  7500  Warts  AM/ 
CW  and  2000  Watts  P.E.P,  SSB  - 
$52,25 


L 


*HtHl«(  TA^a 


•  Modal  TA'33,  3  elements.  10.1 
dB  forward  gain  (over  isotropic 
source)  -  $264.00 


•  Model 
$392.75 

•  AK-60 
$14.60 

•  Model 
$304,7  5 

•  Model 
$392.7  5 

•  Model 
$290,00 

•  Model 


TA-36^  6  elements  — 
mast  plats  ad^t^  ^ 
CL-33,  3  elements  — 
CL-36^  6  elements  — 
CL-203,  3  element*  — 
TA-40    KR    —    40  meter 


conversion  kU  -  $119,50 


Tufts  Radio  Electronics  •  (€1?)  395-82&0 


TELEX. 


PROFESSIONAL  HEADPHONES 

&  HEAOsrrs 


M&ni 

c«ie 

»L(I« 

Cilil 

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cm  ait  , 

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?0  ahffli 

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Freasupncf 

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Wptitnit 

Hiqh 

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$59.95 

Iheindf 


fU^BIIfY   »|M#t  IWUll 

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.»V»tt 

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^axw4 

THRUUNE 

MODEL  43  $125.00 

Elements  (Table  1)  2-30  MHz  45. OO 

Elements  (Table  1)  25  1000  MHz  38,00 

Carryirig  cate  for  Model  43  Si  6  elements  27.50 

Carrying  cb%9  for  1  2  elements  1 7.00 

R£AD  RF  WATTS  DIRECTLY!  (Specify  Type  N  or  S0239  con- 
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—  1,06.  Unequalled  economy  and  flexibility.  Buy  only  the  element(s) 
covering  yoor  present  frequency  and  power  needs,  add  extra  ranges 
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Model  C610 
(S^L610i  Model  0  1320  Model  CM  610    Model  C  1210 


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Model  CM  1320       Modal  CM  t320S 


Mi>del  MB  II  $2eS 
(wtlh  Balun)  $31S 


MB  II  provj'dest 
•Constant  SWR  mQnilonng  *  Prectsion  tunrng  of  tmai  amp  *  Harmonic  suppression 
*  Receiver  inpur  irnpedance-matchmg  *  Maximum  power  transter  lo  anrenna  *Con- 
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Why  Waste  Watts? 
SWR    1 A  $29.95 


SWR-1  guards  against  power  loss!  If  you'^re 
not  pumpinQ  out  all  the  power  yqu^'re 
paying  for^  our  little  SWR-1  combination 
power  meter  and  SWR  bridge  will  tell  you 
%o.  You  read  forward  and  reflected  power 
simultaneously,  up  to  1000  waits  RF  and 
1:1  to  infinity  VSWR  at  3.5  to  150  MHz. 

Got  it  ali  tuned  up?  Keep  it  that  way 
with  SWR'1.  You  can  leave  it  right  in  your 
antenna  circuit* 


o 

< 


t«iaii(4tfl  imc 

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ll%QUH1fE£) 


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Ideal  for  Recseivers  —  Con  vertex 
High  Gain  —  Low  Noite 

FEATURES: 

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When  oiilei-inff  b«  »ui«  TQ  VHCrty 

2.   >ingl«  or  doutjlt  b«ni]  ii«9p 

3    kht  or  Mi#mbl»cl  waniqn 


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USE 

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DATA  SIGNAL,  INC. 


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Tufts  Radio  Electronics 

TC4 


(€17)  39S-B280 


Brian  E,  McAnhur  VESCGE 

67  Nan  wood  Drive 
Brampfon,  Ontario 
Canada  L6W  IMl 


PCs  Are  Easy 

step-by-step  details 


The  vast  decrease  in  the 
cost  of  integrated  cir- 
cuits over  the  past  five 
years  has  opened  a  totally 
new  frontier  for  the  elec- 
tronic experimenter.  Maga- 
zines, such  as  this  one.  of- 
fer a  multitude  of  projects 
designed  to  whet  the  ap- 
petite of  the  most  reluc- 
tant builder.  These  articles 
invariably  offer  schematic 
diagrams,  parts  lists,  sup- 
pliers, and  full  or  half-size 
printed  circuit  board  lay- 
outs. Herein  lies  the  crunch 
of  the  printed  circuit 
board. 

The  avid  experimenter, 
through  frustration,  usual- 
ly ends  up  buying  a  com- 
mercially-made printed  cir- 
cuit board  at  a  rather  high 
price.  This  will  obviously 
yield  the  desired  result,  a 
good-looking  finished 
product.  There  is  not,  how- 
ever, the  self-satisfaction 
of  having  done  it  alt  by 
one's  self. 

An  alternate  and  less  ac- 
ceptable method  is  to  at- 
tempt to  hard  wire  every- 
thing on  the  back  of  a 
piece  of  vectorboard.  (Vec- 
torboard    is    made    of    a 


non conductive    material 

which  has  prepunched 
holes  so  that  component 
leads  may  be  passed 
through  and  soldered  on 
the  other  side  of  the 
board.)  I  cannot  think  of 
any  reason  why  the  com- 
pleted project  should  not 
work  well,  if  reasonable 
care  is  taken  in  parts  layout 
and  soldering.  Aesthetical- 
ly, however,  it  leaves  much 
to  be  desired. 

Where  do  you  go  from 
here?  There  is  only  one  ob- 
vious step,  and  that  is  to 
make  your  own. 

Before  I  get  into  actual 
construction  methods,  per- 
haps I  might  discuss  briefly 
just  what  is  involved  in 
making  a  printed  circuit 
(PC)  board. 

The  basic  PC  board  is 
composed  of  a  thin  layer  of 
copper  coating  on  one  or 
both  sides  of  fiberglass  or 
other  nonconductive  mate- 
rial. To  obtain  the  desired 
circuit  layout,  it  must  be 
reproduced  on  the  PC 
board  using  some  type  of 
"resist."  (Resist  is  the 
coating  which  inhibits  the 
etching  process.)  Once  you 
have  a  perfect  layout,  the 


unwanted  copper  between 
the  traces  must  be  re- 
moved This  process  Is 
called  "etching.''  Ferric 
chloride  solution  is  most 
commonly  used  and  will 
remove  the  unwanted  cop- 
per  in  short  order.  All  that 
remains  then  is  to  clean  up 
the  board,  drill  a  few  holes, 
and  solder  on  the  compo- 
nents. Sound  easy?  It  is, 
Well,  almost  that  easy! 
There  is  still  one  big  prob- 
lem: How  do  you  get 
the  circuit  onto  the  board 
before  you  etch  it? 

There  are  two  answers  to 
that  question.  The  circuit 
layout  can  either  be  drawn 
onto  the  board  or  it  can  be 
done  photographically. 
Both  of  these  methods  will 
be  covered  later  in  this  arti- 
cle. 

Procedure 

To  begin,  there  are  four 
basic  steps  in  the  manufac- 
ture of  circuit  boards: 
Step  1 :    Procure   the 
blank  circuit  board. 
Step    2:    Reproduce 
the  circuit  board  lay- 
out on  the  board  with 
resist 
Step  3:   Etch  the  PC 


board. 

Step  4:  Clean  and  drill 

the  board. 

Now,  let's  deal  with  each 
step  in  turn  and  get  down 
to  the  how-to-do-Tt  stage. 
First,  you  must  obtain  a 
piece  of  blank  circuit 
board  of  sufficient  size  for 
your  project.  Size  is  not  as 
important  as  the  thickness 
of  both  the  copper  and  the 
insulating  backing.  Thin 
copper  will  etch  off  much 
faster,  which  is  helpful,  but 
it  may  not  withstand  as 
much  heat  during  solder- 
ing. The  thickness  of  the 
board  must  be  considered 
when  mounting  heavy 
components  such  as 
transformers,  etc.  You  do 
not  want  a  warped  board! 

Having  satisfied  yourself 
as  to  the  choice  of  board, 
the  next  step  is  to  clean  it 
before  applying  the  resist* 
[I  cannot  emphasize 
enough  that  the  board 
must  be  clean!)  The  sur- 
face  should  be  scoured 
thoroughly  using  a  steel 
wool  soap  pad.  Absolutely 
all  of  the  oxidation  must  be 
removed  and  the  board  left 
in  a  bright,  shiny  condition. 
After  scouring,  the  board 


270 


must  be  rinsed  thoroughly 
under  hot  tap  water  to 
remove  any  soap  residue. 
Dry  it  with  a  clean,  soft 
cloth,  being  careful  not  to 
touch  the  surface  with 
your  hands  as  this  will 
leave  an  oily  film  which 
could  affect  the  applica- 
tion of  the  resist. 

Setting  the  clean  board 
aside  temporarily,  you 
must  decide  which  method 
to  use  in  applying  the 
resist.  There  are  two 
choices  available  — the 
freehand  and  the  photo- 
graphic methods. 

The  freehand  method  re- 
quires that  the  connecting 
foils  be  drawn  on  the  clean 
board  by  hand  with  a  resist 
pen.  Positioning  your  copy 
of  the  full-size  layout  on 
the  blank  circuit  board  and 
fastening  it  securely  with 
Scotch^J^  tape,  still  being 
very  careful  not  to  touch 
the  copper,  take  a  sharp 
center  punch  or  awl  and 
gently,  very  gently,  mark 
all  of  the  holes  by  punch- 
ing through  the  paper. 
When  this  has  been  done 
and  the  paper  removed,  a 
clear  mark  should  be  left 
where  the  components  will 
eventually  be  positioned. 
From  now  on,  the  neatness 
of  the  board  is  determined 
by  how  carefully  the  marks 
are  connected.  The  holes 
should  not  be  drilled  now 
since  the  etch  ant  could 
undercut  around  them  and 
ruin  your  efforts.  For  the 
very  fine  lines,  a  resist  pen 
is  recommended.  This 
looks  very  much  like  an  or- 
dinary magic  marker;  how- 
ever, the  ink  is  resistant  to 
ferric  chloride  solution. 
These  pens  are  not  really 
suitable  for  the  larger  areas 
for  which  resist  is  sold  in 
bottles  and  applied  with  a 
brush.  Every  area  of  cop- 
per you  wish  to  retain  must 
be  thoroughly  coated  with 
resist.  It  isn't  necessary  to 
use  commercially-sold  re- 
sist, since  many  pens  of  the 
waterproof- ink  variety  will 
work  just  as  well,  as  will 
nail  polish,  for  the  larger 
areas. 


At  times,  it  gets  difficult 
to  draw  fine  lines  and  in- 
tegrated circuit  patterns 
which  are  very  small  and  so 
often  required.  There  are 
all  types  of  decals,  rubber 
stamps  and  drawing  aids 
sold  to  help  with  this  prob- 
lem. For  the  larger  and  less 
complicated  circuits,  this 
method  is  best  because  it  is 
quick  and  does  not  require 
a  lot  of  equipment,  just  pa- 
tience and  a  steady  hand. 
The  biggest  drawback  to 
this  method  must  now  be 

apparent. 
What  do  you  do,  though, 

if  a  full-size  layout  is  not 
available?  A  very  compli- 
cated circuit  can  become  a 
nightmare!  Now  is  the  time 
to  investigate  the  photo- 
graphic method. 

Assuming  that  everyone 
at  one  time  or  another  has 
seen  a  black  and  white  neg- 
ative, you  should  realize 
that  it  is  really  not  black 
and  white  at  all,  but  mostly 
made  up  of  varying  tones 
of  grey.  This  is  not  good 
enough  for  these  purposes. 
What  you  need  is  a  full-size 
negative  of  only  two  tones, 
black  and  perfectly  clear. 
This  is  accomplished  by  us- 
ing lithographic  film.  Com- 
mercially, it  is  sold  by 
Kodak    (Kodalith)    and    II- 

ford  (llfolithL  both  of 
which  will  serve  your  needs 
if  the  manufacturer's  di- 
rections are  carefully  fol- 
lowed when  using  these 
films. 

The  first  step  in  making  a 
full-size  working  negative 
is  to  take  a  black  and  white 
picture  of  the  circuit  board 
in  the  magazine  with  a 
camera  and  close-up  at- 
tachment. The  layout  must 
be  kept  perfectly  flat  and 
the  camera  level  and  paral- 
lel to  it,  Care  in  this  part  of 
the  procedure  will  keep  all 
of  the  lines  in  their  proper 
perspective  and  to  scale. 

One  magazine  (that  I 
know  of)  does  not  give  a 
true  black  and  white  cir- 
cuit layout.  Instead,  they 
use  grey,  and  show  the 
components  overlaid  in 
red  ink.  This  does  not  pre- 


sent much  of  a  problem. 
Simply  by  placing  a  deep 
red  filter  over  the  camera 
lens,  presto,  the  com- 
ponents disappear  and  the 
grey  lines  appear  black.  Be- 
cause you  need  the  small 
negative  to  make  the  big 
one,  your  film  has  to  be 
processed.  The  next  steps 
require  the  use  of  an  en- 
larger  and  darkroom,  so 
now  is  the  time  to  enlist  the 
aid  of  the  local  camera 
club  if  this  equipment  is 
not  readily  accessible. 

You  now  progress  into 
the  darkroom  where  you'll 
be  using  the  special  "lith" 
film  mentioned  earlier. 
Lithographic  film  requires 
special  safelights  and  de- 
veloper, so  following  the 
manufacturer's  directions 
is  a  must.  Placing  the  nega- 
tive into  the  enlarger,  pro- 
ject the  image  onto  the 
easel  and  focus  it  perfect- 
ly. You  must  project  the  im- 
age the  exact  size  of  the 
printed  circuit  board  you 
desire,  or  none  of  the  com- 
ponents will  fit.  This  is 
quite  easily  accomplished. 
Simply  place  the  full-size 
magazine  layout,  photo- 
graphed earlier,  under  the 
enlarger  and  adjust  the 
projected  image  until  both 
are  exactly  the  same  size. 
If  the  layout  was  only  half 
scale  to  begin  with,  you 
will  have  to  measure  the 
size  of  some  known  com- 
ponent and  adjust  the  im- 
age to  suit.  The  enlarger  is 
switched  off  and  the  maga- 
zine layout  is  removed 
from  under  the  enlarger  and 
replaced  with  a  piece  of 
lithographic  film.  Exposure 
for  the  film  may  vary,  but  a 
figure  of  thirty  seconds  is  a 
good  starting  point.  The  ex- 
posed film  is  placed  in  the 
developer  for  about  one 
and  a  half  minutes,  stop 
bath  for  fifteen  to  thirty 
seconds,  and  then  fixed  ac- 
cording to  the  instructions. 
Before  turning  on  the 
lights,  you  must  put  away 
the  rest  of  the  lith  film.  The 
wet  full-size  positive  must 
now  be  washed  and  al- 
lowed to  dry. 


The  next  part  of  the  pro- 
cess is  relatively  easy. 
After  the  full-size  has 
dried,  you  can  make  the 
full-size  negative  that  you 
were  after  in  the  first  place. 
The  positive  is  placed  on 
top  of  a  sheet  of  lith  film 
(again  in  the  darkroom)  and 
a  clean  sheet  of  glass 
placed  on  top.  The  glass 
will  keep  everything  flat, 
while  you  make  a  contact 
negative  by  exposing  the 
film  to  light,,  A  60-Watt 
lamp  held  two  feet  above 
the  film  for  15  seconds  is 
approximately  the  right 
amount  of  time,  The  film  is 
processed  as  before,  and, 
while  it  dries,  carry  on  with 
the  next  step,  the  prepara- 
tion of  the  circuit  board. 

In  order  to  transfer  the 
image  of  the  full-size 
negative  to  the  circuit 
board,  you  must  first  coat 
it  with  "etchant  resist  sen- 
sitizer." This  type  of  resist, 
available  in  an  aerosol 
spray  can,  when  deposited 
on  the  circuit  board,  makes 
it  sensitive  to  light  much 
like  a  photographic  paper, 
except  in  this  case  it  is 
most  sensitive  to  ultra- 
violet light.  The  spraying  of 
the  circuit  board  must  be 
done  in  the  darkroom 
under  a  safelight  with  ade- 
quate ventilation.  Starting 
from  the  bottom,  spray  the 
board  evenly,  holding  the 
can  about  5  to  8  inches 
away.  The  resist  looks  like 
a  thin  lacquer  with  a 
purplish  tint  to  it.  The  ex- 
cess is  allowed  to  run  off 
by  holding  the  circuit 
board  vertically  by  the 
edges.  Now  put  it  away  to 
dry  overnight,  somewhere 
where  it  will  not  be  ex- 
posed to  light. 

The  time  has  now  ar- 
rived to  expose  the  circuit 
board  to  ultraviolet  (UV) 
light.  Carefully,  the  full- 
size  negative  is  placed 
over  the  treated  circuit 
board  in  the  darkroom  and 
covered  with  the  sheet  of 
glass  to  hold  it  flat.  In  order 
to  expose  it  to  ultraviolet 
light  the  board  should  be 
placed  outside  in  the  sun 


271 


^^ 


about  one  and  a  half 
minutes  or  under  a  sun 
lamp.  (I  use  a  sun  lamp 
about  18  inches  above  the 
board  and  expose  for  1 
minute.) 

The  PC  board  is  brought 
back  into  the  darkroom 
and  developed  in  ''photo- 
etching  developer/'  This 
chemical  dissolves  the 
resist  which  was  not  ex- 
posed to  UV  light.  After 
careful  washing,  the  board 
is  allowed  to  dry.  (For  safe- 
ty's sake,  read  and  follow 
all  instructions  on  both  the 
resist  and  developer  con- 
tainers because  they  are 
both  highly  toxic  and 
volatile  chemicals  requir- 
ing a  lot  of  ventilation.) 

After  taking  one  last 
look  and  possibly  touching 
up  an  area  or  two  with  the 
resist  pen,  you  now  are 
ready  to  actually  etch  the 
circuit  board  using  ferric 
chloride  solution.  (Take  my 
word  for  it,  ferric  chloride 
solution    is   a    highly   cor- 


rosive substance  which  will 
eat   its   way   through   the 

copper,  the  concrete  floor, 
or,  as  1  found  out  the  out- 
side of  my  wife's  washing 
machine.  Wear  gloves  artd 
eye  protection,  and  follow 
the  instructions  to  the  let- 
ter!) 

Having  chosen  a  glass 
tray,  not  metal,  of  ap- 
propriate size,  pour  in  the 
ferric  chloride  solution  to  a 
depth  of  about  three 
quarters  of  an  inch.  The 
solution  is  used  at  room 
temperature  and,  again,  in- 
halation of  the  fumes 
should  be  carefully  avoid- 
ed. The  PC  board  is  placed 
into  the  ferric  chloride 
solution  face  up  and 
agitated  gently  by  raising 
and  lowering  the  tray 
about  one  inch.  The  etch- 
ing process  will  take 
about  one  half  hour,  so  pa- 
tience is  the  key  word  here. 

When  sufficient  time  has 
elapsed,  the  PC  board  is 
removed  from  the  solution 


and  the  etchant  gently 
washed  off  under  running 
water.  By  holding  the 
board  up  to  the  light,  you 
can  see  if  all  the  unwanted 
copper  has  been  removed. 
If  not,  replace  the  PC 
board  in  the  etchant  and 
continue  agitation.  The 
completely-etched  board 
will  have  to  be  scoured 
with  the  soap  pad  again  to 
remove  all  the  resist.  There 
are  chemical  removers,  but 
this  is  the  easiest  way  and 
makes  the  board  easy  to 
solder,  too. 

Steps  1 ,  2,  and  3  were  the 
hardest,  and  drilling  the 
board  is  child's  play  in 
comparison.  The  only  trick 
here  is  to  use  the  correct 
size  of  drill  bit  (see  the  drill 
guide  in  Table  1)  to  fit  the 
electronic  components.  A 
drill    press    is    an    asset. 


although  not  a  necessity;  a 
little  care  will  go  a  long 
way. 

All  of  the  items  used  in 
this  article  are  available  in 
most  areas  from  the  local 
electronics  supplier.  The 
resist,  developer,  and  etch- 
ant will  run  about  $15.00, 
but  that  will  do  many, 
many  PC  boards.  The 
lithographic  film  costs 
about  $30,00  for  fifty  8"  x 
10''  sheets.  It  is  definitely 
more  expensive  to  make 
the  PC  boards  photograph- 
ically,  but  the  results  cer- 
tainly justify  the  expense  if 
more  than  one  board  is  go- 
ing to  be  made. 

Thus,  with  a  little  time 
and  effort,  home  manufac- 
ture of  printed  circuit 
boards  can  be  both  rela- 
tively easy  and  definitely 
self-satisfying.  ■ 


Number  65  drill 
Number  60  drill 
Number  56  drill 


#20  AWG  wire;  Molex  pin;  V4-Watt  resistor 

V2-Watt  resistor 

1'  or  2'Watt  resistors;  IC  sockets 

7ab/e  1,  Drill  guide. 


New  Products 


from  page  2S2 

The  122"'long  vertical  ele- 
ment  and  four  14^4"-long 
radiaJs  of  the  G 7-220  are  made 
from  high-strength  heat-treated 
aluminum.  Each  radial  has  a 
3/16"  o.d.  The  G7-220^s  N^type 
connector,  used  on  all  new 
Hustler  amateur  verticals,  pro- 
vides a  tight  all-weather  seal 
and  virtually  perfect  rf  charac- 
teristics under  all  conditions, 

The  G7-220  weighs  only  7 
pounds,  and  is  easily  mounted 
on  any  capable  vertical  support 
of  up  to  IV4"  o.d.  The  wind 
loading  of  the  antenna  is  only 
26  pounds  at  100  mph  veloci- 
ties. 

For  further  information  on 
this  or  other  Hustler  products, 
write:  Sahs  Department,  New- 
Tronics  Corporatfon,  15800 
Commerce  Park  Drive,  Brook- 
park  OH  44142.  Reader  Service 
number  N2. 

B  ELD  EN  INTRODUCES  TWO 

NEW  LOW-NOISE  COAXIAL 

CABLES 

For  high-Impedance  appiica- 
tions,  including  test  leads  and 
instrumentation,  Beiden  Cor- 
poration's  Electronic  Division 


has  introduced  two  low-noise 
coaxial  cables. 

The  two  are  a  1 74/U-typ6  with 
26-gauge  stranded  conductor 
(no.  9239),  and  a  SWUtype  with 
a  22-gauge  solid  conductor  (no. 
9224).  Construction  details  in- 
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steel  conductors,  polyethylene 
insulation,  and  a  conductive 
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and  .242  inch  (9224). 

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write:  Manager,  Marketing  Com- 
munfcations,  Beiden  Corp,,  2000 
S.  Batavia  Ave.,  Geneva  iL  60134. 
Reader  Service  number  B41. 


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273 


Merwirt  Updyke  WB3EUG 
609  Belt  Avenue 
Aiioana  PA  16602 


The  Games  People  Play 


why  not  hams? 


Pldyirig  games  on  ham 
radio  is  nothing  new. 
There  is  almost  always 
someone  on  the  air  who 
will  play,  dnd  the  element 
of  radio  communication 
adds  a  new  twist  to  any 
game.  A  good  ham  game 
could  liven  up  dead  bands, 
fill  those  extra  hours,  pro- 
vide excellent  opportuni- 
ties for  those  who  are  not 
particularly  given  to  rag 
chewing  or  new  "mike  shy" 
hams,  give  use  to  little- 
used  2  meter  simplex  chan- 
nels, and  possibly  even 
make  some  new  "wall- 
paper" available  for 
award-conscious  oper- 
ators. 

But  good  ham  games 
have  been  few  and  far  be- 
tween. To  be  well  used  on 
the  air,  a  game  should 
fulfill  alt  or  most  of  the 
following  requirements: 
The  ideal  ham  game  must 
1)  be  easily  played  by  two 
people,  2)  be  able  to  be 
played  with  only  a  paper 
and  pencil  as  well  as  on 
commercial  game  boards, 


3)  have  rules  that  are  sim- 
ple and  can  be  easily  given 
over  the  air  to  someone  not 
at  all  familiar  with  the 
game,  4)  be  able  to  be 
played  in  a  relatively  short 
time,  5)  have  individual 
moves  or  plays  that  can  be 
executed  in  a  short  time, 
and  6)  be  challenging  and 
contain  logically  varying 
degrees  of  difficulty  to  en- 
sure continued  interest  and 
allow  advancement  in 
playing  skid. 

After  1  found  two  games 
that  met  these  re* 
quirements,  a  topical  CQ 
of  "CQ  game,  CQ  for  a 
game"  brought  hours  of 
challenge  and  enjoyment. 
Why  not  give  them  a  try 
yourself? 

Game  #1 

This  one  is  my  favorite 
and,  of  the  two,  holds  the 
most  promise  for  a  game 
that  will  be  played  on  the 
air  for  years.  Master 
Mind®  by  Invicta  Blastics, 
Ltd,,  is  a  new  game  that  has 


won  tremendous  popular- 
ity throughout  the  world. 
There  are  even  British 
National  Master  Mind 
Championships  held  year- 
ly. It  is  said  to  be  80%  logic 
and  only  20%  luck,  is  inex- 
pensive to  buy  in  its  attrac- 
tive game  board  form, 
can  be  played  almost 
anywhere  (even  comes  in  a 
pocket-size  board  good  for 
field  days,  etc),  and  comes 
with  instructions  in  ten 
languages. 

Rather  than  give  more 
details  of  the  game,  the 
following  is  offered  as  an 
explanation  suitable  for 
use  on  the  air  with  a  person 
who  has  no  knowledge  of 
the  game.  You  may  want  to 
make  a  few  changes,  but  I 
found  this  order  to  work 
well.  These  rules  are 
designed  for  convenient 
use  of  the  board  by  I  nvicta. 

After  calling  "CQ  game" 
and  having  secured  a 
promise  to  at  least  give  it  a 
try,  give  the  following  in- 
structions: 

1,     Secure   a    piece   of 


lined  paper  and  a  pencil  or 

pen. 

2.  There  are  6  colors. 
Write  down  "R"  for  red, 
"W"  for  white,  "Bu"  for 
blue,  "C"  for  green,  "Y"  for 
yellow,  and  "Bk"  for  black. 

3.  Number  down  10 
lines,  starting  with  10  and 
ending  with  one 

4.  Above  these  10 
lines,  write  a  4-color  code 
of  any  combination  of  the 
6  colors.  For  this  first  game, 
do  not  repeat  a  color;  use 
four  different  colors. 

5.  Starting  with  line 
one.  I  will  try  to  break  the 
code.  I  will  give  you  a 
4-color  code.  Write  it 
down.  Then  give  me  a 
rating  of  "Xs"  and  "Os," 
Write  on  your  paper  "X"  = 
right  color  and  right  place; 
"O"  =  right  color  but 
wrong  place. 

If  I  have  two  reds,  for  ex- 
ample, but  your  code  has 
one  red,  I  get  only  one  ''X" 
or  ''O",  depending  on  posi- 
tion. The  order  you  give  me 
the  "Xs"  or  "Os"  is  not  to 
show  anything  about  the 


274 


order  of  the  ones   I   have 
right. 

6.  I  have  up  to  ten  tries 
to  match  your  code.  The 
winner  is  the  one  who 
breaks  the  code  in  the  least 
amount  of  trys.  Any  ques- 
tions? My  try  for  line  one  is 

.   What  is  my 

rating? 

7.  When  he  gives  a 
rating,    say    'That   means 

..."  and  explain  the  rating 
to  be  sure  he  understands. 

A  condensed  form  of 
these  rules  for  quick 
reference  is  found  in  Table 
2.  Both  players  should  be 
keeping  track  of  the  entire 
game  on  a  board  or  paper 
(the  board  is  generally 
easier).  After  you  break  his 
code,  make  one  for  him, 
and  the  play  goes  on  You 
will  find  that  it  helps  to 
"think  out  loud'  over  the 
air. 

The  sample  game  in 
Table  1  should  help  you  to 
better  understand  the 
above  instructions.  Try  to 
break  the  code  on  the  next 
try.  The  answer  is  at  the 
end  of  this  article, 

If  your  experience  runs 
like  mine,  you'll  find  your 
opponent  saying,  "Once  is 
not  enoughr',  and  the 
minutes  will  quickly  and 
enjoyably  pass  by.  Hope- 
fully there  will  soon  be 
many  on  the  air  who  have 
played  a  few  times.  That's 
when  the  many  variations 
keep  the  game  going 
strong.  First  remove  the 
restriction  that  all  the  col- 
ors must  be  different.  You 
can  make  the  code  all  one 
color  if  you  want.  Next  you 
might  want  to  change  the 
number  of  possible  com- 


10 

9 


r 

6 
5 

4  W  R  By  G   00 
3  R  Bk  G  By  OXX 
2  Bu  G  Bk  Y  000 
1  G  W  Y  R  COX 

7ab/e    7.    Sample    Master 
Mind  game. 


bin  at  ions.     For    young 
children,  you  may  want  to 
make  it  three  positions  and 
only  four  colors.   But  you 
will  most  likely  want  to  in- 
crease the  number  of  possi- 
ble   combinations.    The 
regular  Master  Mind  game 
(the  one  just  explained)  has 
1296  permutations,  but,  by 
allowing  an  empty  space  to 
be    played    as    a    color 
(designated  with  an  "S"  on 
the  air),  it  increases  the  per- 
mutations to  2401.  Those 
who  expect   to  enjoy  this 
game  and  want  to  further 
develop    their    skills    may 
want  to  purchase  the  Super 
Master    Mind    version    of 
the  original  (also  by  Invicta 
Blastics,    Ltd.).    It   can    be 
played  as  the  version  ex- 
plained above,  but  allows 
for  a  game  with  5  positions 
and   eight  colors  (orange, 
''O",  and  brown,   'Br",  are 
added),  allowing  1 2  tries  to 
find  the  one  of  32,768  (or  if 
space  is  used,  then  one  of 
59,049)  permutations  in  the 
code.  (Note:   The  formula 
is:  no.  of  permutations  — 
CP,  where  C  =  no.  of  col- 
ors and  P    ~    no.  of  posi- 
tions.)   Other    interesting 
variations,  such   as  allow- 
ing   the    codemaker    to 
make  one  incorrect  rating 
during    the   game   are   of- 
fered   in    Modern    Board 
Games,    edited    by    David 
Pritchard  and  published  by 
William    Luscombe    Pub- 
lisher,  Ltd.,  which  should 
be  available  at  your  local 
library. 

Developing  strategies  is 
an  important  part  of  the 
game  and  is  necessary  for 
the  more  advanced  games. 
Also,  the  codemaker  can 
learn  to  play  more  of  an  ac- 
tive role  as  he  analyzes  his 
opponent  and  tries  to 
psyche  him  out  with  little 


1.  Secure  paper  and  pencfL 

2.  Colors  =  R,  W,  8u.  G.  Y,  Bk. 

3.  Number  10  lines. 

4.  Write  down  code. 

5.  Rate  each  try  "X  '  or  "0'\ 
6v  Review  rating  given. 

Table  2.   Master  Mind  in- 
structions. 


"extra  comments/'  The 
history  of  the  game  and  its 
tremendous  popularity 
make  interesting  rag  chew- 
ing. All  this,  plus  discussion 
of  tournaments  and  many 
more  topics  (with  even  a 
short  chapter  on  com- 
puters that  play  Master 
Mind),  can  be  found  in  The 
Official  Mastef  Mind  Hand- 
book by  Leslie  H.  Ault, 
published  by  Signet.  It's  a 
must  for  the  serious  Master 
Mind. 

For  those  who  desire 
more  practice,  a  computer 
pocket  calculator-type 
game  that  will  play  against 
you  is  offered  by  Milton 
Bradley  Co.  under  the 
name  Comp  IVTM  Yqu  cgp 
play  this  with  up  to  5  posi- 
tions and  10  choices.  Cost 
is  around  S25.00. 

This  game  presents  a 
golden  opportunity.  Why 
not  have  some  awards  for 
the  Master  Mind  ham? 
How  about  WM-20— won 
Master  Mind  in  20 
states  — or,  for  real 
operators,  WMAS  — won 
Master  Mind  in  all  states? 
Perhaps  a  grueling 
challenge  would  be  MDX- 
15  — Master  Mind  played 
DX  in  15  countries— or  the 
ultimate;  MDXCCl  Well, 
anyway,  it  would  be  great 
to  see  some  enterprising 
ham  advertising  saying 
'^Send  $1,50  with  a  log 
to  .  _  "  for  some  sort  of 
Master  Mind  or  game 
award.  Perhaps  a  common 
frequency  could  be 
chosen. 

Who    knows,    maybe 


there  will  even  be  some 
''Mind  nets''  and  "tour- 
naments in  the  air"  and 
.  .  .  better  get  on  to  the 
next  game. 

Game  #2 

Here  is  another  game 
that  meets  most  or  all  of 
the  requirements  previous- 
ly stated.  Those  who  tire  of 
Master  Mind  [devotees  say 
that  this  is  impossible]  may 
find  that  this  game  offers 
the  variety  needed  to 
spruce  up  their  ham  game 
venture.  This  game,  which 
is  also  offered  in  plastic 
under  various  names  (Tri- 
Tac-Toe  at  )C  Penney  for 
$6,951  is  a  complex  varia- 
tion of  tic-tac-toe  I  call  Tri- 
Tac  (for  three-dimensional 
tic-tac-toe). 

Following  are  two  varia* 
tions  of  the  game,  the  sec- 
ond being  the  more  dif- 
ficult The  first  game  re- 
quires 3  in  a  row,  the  sec- 
ond requires  4  in  a  row.  The 
rules  are  the  same  as  in 
regular  tic-tac-toe,  except 
that  those  in  a  row  can  be 
on  different  levels.  Letters 
and  numbers  provide  easy 
coordinates  for  positioning 
^'Xs"  and ''Os"  over  the  air. 
In  the  examples  given  in 
Fig.  1,  1  use  the  letters  a,  b, 
c,  and  d  to  show  winning 
combinations.  Study  them 
and  try  to  imagine  them 
stacked  up  in  layers  to 
form  a  cube. 

For  the  first  game,  the 
person  challenged  goes 
first;  thereafter,  the  winner 
goes  first  The  challenged 
calls  coordinates  to  place 


275 


( 

2 

s 

1 

2 

S 

4 

A 

b 

b 

k 

B 

b 

B 

a 

C 

L 

c 

c 

.0 

a 

D 

E 

■ 

F 

E 

a 

F 

c 

b 

G 

L 

a 

H 

a 

H 

{l 

1 

k 

ii 

i 

c 

K 

L 

a 

c 

b 

1 

M 

■ 

fl 

N 
0 
P 

d 

tt 

d 

d 

C 

tF 

Fig.  1.  Trf-Tac. 

his  ''O",  the  challenger 
calls  coordinates  to  place 
his  "X",  and  so  on,  until  one 
person  gets  his  required 
number  in  a  row  and  is  thus 


the  winner. 

You  may  want  to  write 
down  a  list  of  instructions 
to  be  given  over  the  air  for 
Tri-Tac,  as  was  done  for 
Master  Mind. 

Yet  another  variation 
that  can  be  played  on  the 
four-grid  version  would  be 
to  give  each  player  two 
markers ^to  one,  ''W"  and 
'X;  to  the  other,  "Y"  and 
"Z"  — allowing  for  either  to 
be  played  at  any  time.  The 
first  to  get  four  of  one  of 
them  in  a  row  wins.  Or  try  it 
as  the  first  to  get  both  of 
his  markers  four  in  row  is 
the  winner. 

Again,  some  Tri-Tac  en- 
thusiast should  offer  a  few 
awards  as  for  Master  Mind. 
Will  you  accept  this 
challenge? 

I  hope  you  enjoy  these 
ham  games  as  much  as  I 
have.  When  playing,  keep 
the  individual  plays  short 
repeat  plays  and  instruc- 
tions often,  think  out  loud 
so   as  to  occupy  the  fre- 


quency, and  watch  that 
10-minute  timer  for  ID. 
Even  if  no  one  offers 
awards,  you  may  want  to 
keep  a  notebook  of  all 
your  games,  times,  etc.,  for 
review  and  strategy  devel- 
opment. 

''Okay,  my  first  try  is  W, 
Bu,  Y,  R.  What's  my 
rating?'' 

(By  the  way,  the  answer 
for  the  sample  Master 
Mind  isY,  Bk,  G,  R.  It  is  not 
one  of  the  most  simple  you 
will  run  into,)B 

Editor's  note: 

i  enjoy  Master  Mind 
enough  so  that  Sherry  and  I 
take  one  along  on  trips  and 
use  it  during  plane  rides  to 
while  away  the  time.  Super 
Master  Mind  has  eight  col- 
ors of  pegs  and  five  holes, 
making  it  even  more 
demanding  than  run-of-the- 
mill  Master  Mind. 

Then  you  can  play  the 
same  game  with  words. 
Thirik  up  a  real  stinky  four- 


letter  word  and  use  the 
same  system  for  playing- 
This  takes  no  equipment  at 
alt  other  than  a  pencil  and 
pad.  Sherry  and  I  have 
played  this  while  driving. 

Card  games  have  been 
difficult  to  play  over  the 
air .  .  .  obviously.  But  wrfh 
the  advent  of  microcom- 
puters which  can  shuffle 
and  deal  cards  for  us, 
perhaps  the  day  of  the  over- 
the-air  gin  rummy  game  is 
not  that  far  of f.  If  any  group 
gets  going  with  this  and  gets 
porky  about  their  prowess 
at  cribbage,  ril  be  on.  fre- 
quency to  challenge. 

Computers  can  throw 
dice  for  us,  too,  making 
backgammon  possible. 
Please  be  sure  to  let  73 
know  if  you  get  involved 
with  this  sort  of  mischief. 

Oh,  if  you  would  tike 
some  rotten  words  for 
Word  Master  Mind,  you 
might  try:  BUNK  PUMP, 
LULL,  XRAY,  }AZZ,  FIZZ, 
FLOX,  etc. -Wayne. 


YEARS  WARRANTY! 

EXACT  Replacements  for 

SYLVANIA     •*^** 


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4.24 

320 

26.00 

J  57 

1.63 

l^fi 

l.*S 

283 

6.32 

321 

7,65 

lie 

l.M 

199 

.59 

284 

T.35 

322 

l.SO 

ii* 

.66 

210 

1.37 

285 

7.99 

321 

3,53 

160 

i.ti 

ZU 

1.5« 

286 

i.7i 

324 

3.53 

161 

,*S 

lU 

l.Oi 

i«7 

.69 

325 

27.50 

162 

5h75 

119 

4 .  16 

288 

,n 

MA 

.94 

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276 


W2NSD/1 

HEVER  SAY  DIE 

editor/at/  by  Wayne  Green 


from  page  255 

able  to  take  a  simple  business 
trip  and,  for  less  than  the 
regular  fare,  fly  anywhere  In  the 
Eastern  system  , . .  and  this  in- 
cludes such  interesting  DX  hot 
spots  as  Saint  Martin  {which  is 
two  countries!),  Martinique, 
Trinidad,  and  a  lot  of  other 
great  Caribbean  islands. 

Write  ahead  and  get  your 
license  from  the  Department  of 
Telecommunications.  If  you 
wait  until  you  get  there,  you 
may  find  yourself  up  against 
several  days  of  red  tape,  and  be 
back  home  before  the  ticket 
comes  through. 

Here*s  the  only  border  be- 
tween the  French  side  of  Saint 
Martin  and  the  Dutch  side, 
Saint  Maartens,  It's  just  a 
marker  alongside  the  road,  and 
you  have  to  keep  your  eyes 
open  to  see  it. 


You'll  find  that  there  are 
other  demarcations  between 
the  two  countries  when  you  try 
to  make  a  phone  call  from  the 
Dutch  side  to  the  French.  Good 
luck  in  dealing  with  the  French 
operators  ...  if  they  get  off 
lunch  break. 

We  could  use  a  lot  more  ac- 
tivity in  the  islands^  so  check  in- 
to the  Eastern  fares  and  see  if 
you  can't  activate  an  island  for 
a  few  days  and  find  out  why 
some  hams  get  so  addicted  to 
DXpeditioning.  With  the  cur- 
rent line  of  tiny  rigs,  you  can 
carry  one  along,  complete  with 
antenna,  right  under  the  plane 
seat. 

The  Eastern  fares  have 
substantially  changed  the 
economies  of  the  Islands,  so 
youMI  want  to  be  sure  to  reserve 
your  seat  well  ahead  of  time 
and  make  sure  that  you  have  a 


-S'  :• 


1' 


r ,  " 


■AUK  ^ 


hotel  reservation,  complete 
with  permission  to  use  your 
ham  rig  and  antenna,  YouMI 
want  to  save  up  some  money, 
too,  for  the  boom  in  Caribbean 
travel  which  has  resulted  from 
the  Eastern  fares  has  also 
jacked  up  the  costs  of  hotels, 
food,  etc. 

AUGUST  WINNER 

"Ham  Radio  Is  NOT  A  R*ch 


Man*s  Hobby"?  Rick  Ferrantf 
WA6NCX/1,  author  of  August's 
most  popular  article,  will  find 
himself  fn  a  slightly  higher  in- 
come bracket  this  year,  thanks 
to  the  $100  prize  our  readers 
voted  him  with  their  Reader 
Service  card  ballots.  Rick,  we 
suggest  you  drop  the  hobby  or 
stop  writing  crackerjack  ar- 
ticles for  73 — or  it  will  be  a  rich 
man*s  hobby  for  you. 


Ham  Help 


I  am  a  public  school  teacher 
at  the  Pine  Point  Experimental 
School  on  the  White  Earth  In- 
dian Reservation  in  Minnesota. 
The  school  is  the  main  focus  of 
the  Pine  Point  community,  and 
is  involved  with  preschoolers 
through  adults. 

There  is  much  interest  on  the 
part  of  the  students  and  com- 
munity m  general  in  com- 
munications, and  many  stu- 
dents are  excited  about  study- 
ing for  their  amateur  radio 
licenses  and  starting  a  ham 
club.  Interest  was  spurred  by 
the  CB  club  we  started  last 
spring,  but  the  sunspot  cycle 
put  the  iid  on  legal  11  meter 
communications  during  the 
school  day.  The  motivation  and 
built-in  incentives  in  ham  radio 
would  serve  an  important  func- 
tion here,  especialty  during  the 
long  and  frigid  winter. 

In  addition,  the  Tribal  Coun- 
cil has  been  talking  of  a  future 
Chippewa  radio  station  to 
cover  the  reservation,  and  ham 
radio  would  be  the  seed  from 
which  engineers  and  techni- 
cians could  grow. 

ff  any  individual,  organiza- 
tion, or  company  could  provide 
the  school  with  worki  ng  station 
or  test  equipment,  learning 
aids,  etc.,  new  or  used,  donated 
or  at  low  cost,  please  contact 
me  at  the  school. 

Walter  Kfmmel  KBOCB 
Fine  Point  Experimental 

School 
Ponsford  MN  56575 


1  need  a  diagram  or  Informa- 
tion  on  a  2  meter  1  W-in/10 
W-out  amplifier.  The  circuit 
board  has  #85-1661^091974- 
080674  printed  on  one  side  and 
the  other  side  has  #85*1 66M 
plus  2  other  numbers.  A  thick 
aluminum  panel  has  #203-1466 
stamped  on  it.  It  uses  one 
2N5589  and  one  2N5590.  H  has 
a  4PDT,  12-volt  relay  built-in  on 
the  board,  I  am  also  missing 
coils  L304  and  L305.  Can 
anyone  help?  I  will  pay  you  for 
whatever  is  needed  to  copy  the 
info. 

Jung  Y.  Lem  KB6B0 

5222  Coringa  Dr. 

Los  Angeles  CA  90042 

I  need  a  manual  or  schematic 
for  a  Swan  11 7B  (117  V  ac) 
power  supply.  Thanks. 

B.  Mongeau 

2215  Marie  Victorin 

Sillery,  Quebec 

Canada  G1T  1J6 

I  am  in  need  of  a  schematic 
diagram  for  a  Royal  Canadian 
Navy  transmitter-receiver,  type 
FR-12-PH  05161-PH,  The  rating 
is  12  V  do  6  A  cont.,  11  A  int., 
spec,  is  122904,  and  it  was 
manufactured  in  1944  by  the 
Canadian  Marconi  Company. 
Also,  I  would  like  the  address  of 
the  Canadian  Marconi  Com- 
pany in  Canada,  if  at  all  possi- 
ble. 

Emil  Sohuchardt,  Jr. 

21  East  Clark  St, 

Springfield  OH  45506 


277 


OSCAR  Orbits 


Oscar  7  Orbilal  Information 


Oscars  Orbital  Information 


The  listed  data  tells  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  calculate  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  !ess  five  minutes).  The  chart  gives  the  longitude  of 
the  day's  first  ascending  (northbound)  equatorial  crossing.  Add 
29*  for  each  succeeding  orbit.  When  OSCAR  is  ascending  on  the 
other  side  of  the  world  from  you,  it  wilt  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  should 
be  abfe  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  Jf  it 
passes  right  overhead,  you  should  hear  it  for  about  24  minutes 
total.  OSCAR  7  will  pass  an  Imaginary  line  drawn  from  San  Fran- 
cisco to  Norfolk  about  12  minutes  after  passing  the  equator.  Add 
about  a  minute  for  each  200  miles  that  you  live  north  of  this  tine.  If 
OSCAR  passes  1 5  *  east  or  west  of  you,  add  another  minute;  at  30  ^ 
three  mmutes;  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,  145.975%925  MHz  downlink,  beacon  at 
145,972  MHz, 

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.  Due  to  incorrect  tracking  information  ob- 
tained during  the  early  days  of  OSCAR  S,  the  equator  crossing 
times  contained  in  most  published  charts  are  in  error-  To  correct 
this  error,  multiply  the  orbit  number  by  0.00205  minutes  and  add 


Orbit 

Date 

Time 

Longitude 

Orbit 

Date 

Tirrt& 

Longitude 

{Dec) 

(GMT) 

Cmseing  ^W 

(Dfic^ 

(GMT) 

of  Eq. 

1^495  Bbn 

1 

0009:15 

62.7 

3771  Abn 

1 

0111:17 

59,6 

1&50BAbn 

2 

0103L32 

76.a 

3766  Jbn 

2 

0116:29 

60.g 

1S520Bbn 

a 

0002:53 

©12 

3799  Jbn 

3 

0121:39 

62.2 

13533  Bbn 

4- 

0057:10 

74.8 

3613  Abn 

4 

0126:50 

63.5 

185^6Abn 

5 

0151:27 

88.3 

3627  Abn 

5 

0132:01 

64,8 

l355S8bn 

6 

0050:48 

73.2 

3841  X 

S 

0137:12 

66.1 

18571  Bbn 

7 

0145:05 

see 

3355  Abn 

7 

0142:24 

67.4 

18563  Ahn 

8 

0044126 

71.6 

3868  Abn 

8 

0004:21 

42,9 

Ifl596  Bt>n 

9 

0136:43 

85,2 

3882  Jbn 

,9 

0009:32 

44.2 

lS60BBl>n 

10 

00313:04 

70.1 

3696  Jbn 

10 

0014:43 

45.5 

1 6621  Abn 

11 

0132:21 

83.7 

3910  Abn 

11 

0019:54 

46,8 

13633  Bbn 

12 

0031:42 

esj 

3924  Abn 

12 

0025:05 

46,2 

18646  Bbn 

13 

0125:59 

82:1 

3936  X 

13 

0030:16 

49.5 

18658  Abn 

14 

0025:20 

67.0 

3952  Abn 

1^ 

0035:27 

50.8 

18671  Gbn 

15 

0119:37 

80.5 

3966  Abn 

15 

0040:33 

52.1 

18683  fibn 

16 

0018:5T 

65.4 

3980  Jbn 

16 

0045:49 

53.4 

18696  Abn 

17 

0113:15 

79.0 

3994  Jbn 

17 

0051:00 

54.7 

16706  Bbn 

18 

0012:35 

63,8 

4008  Abn. 

18 

0055:11 

56;o 

larai  Bijn 

19 

0106:53 

774 

4022  Abn 

19 

0101:22 

57.3 

13733  A  bn 

20 

0006:13 

62.3 

4036  X 

20 

0106:33 

58.6 

18746  Bbn 

21 

0100:31 

75.9 

-^050  Abn 

21 

0111:44 

59.9 

18759  Bbn 

22 

0154r4B 

895 

4064  Abn 

22 

0116:54 

61.2 

18771  Abn 

23 

0054:08 

74.3 

407B  Jbn 

23 

0122:05 

62.6 

18734  Bbn 

24 

0143:26 

a7.9 

4092  Jbn 

24 

012;^:16 

63.9 

18796  Bbri 

25 

0047:46 

72.S 

4106  Ahn 

25 

0132:27 

65.2 

iae09  Abn 

26 

0142:04 

BS.3 

4120  Abn 

25 

0137:38 

665 

18821  Bbn 

27 

0041:24 

71.2 

4134  X 

27 

0142:49 

67.3 

16834  Bbn 

28 

0135:41 

84.6 

4147  Abn 

26 

0004:46 

43.3 

1 8646  Abn 

29 

0035:02 

69.6 

4161  Abn 

29 

0009:57 

44.6 

13359  Bbn 

30 

0129:19 

832 

41 75  Jbn 

30 

0015:07 

45-9 

18671  Bbn 

3t 

0026:40 

66.1 

4189  Jbn 

31 

0020:18 

47,2 

the  result  to  the  equator  crossing  time  as  printed  in  the  chart.  For 
example,  the  published  time  tor  orbit  number  3352,  the  first 
equatorial  crossing  on  November  1, 1978,  is0018;50  UTC.Thus,  for 
orbit  number  3352,  the  corrected  equatorial  crossing  time  would 
be: 

Corrected  time  =  0018:50  +  (3352  x  0.00205  minutes) 

=  0018:50  +  (6.8716  minutes) 
=  0025:42,3 
The  longitude  figures  contained  in  the  OSCAR  8  chart  are  virtualfy 
unaffected  by  this  tracking  error.  The  chart  gives  the  longitude  of 
the  day*Q  first  ascending  equatorial  crossing^  Add  28°  for  each 
succeedi  ng  orbit.  To  find  the  time  OSCAR  8  passes  the  North  Pole, 
add  26  minutes  to  the  time  it  crosses  the  equator.  OSCAR  8  will 
cross  the  imaginary  San  Francisco-toNorfolk  line  about  11 
minutes  after  crossi  ng  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,  435.20435.10  MHz  downlink,  beacon  at 
435.090  MHz. 


Canadian  Amateur  Radio  Federation,  itic. 


DOC  PUBLISHES  DETAILS  OF 

NEW  "NO-CODE"  '^DIGiTAL^' 

CERTIFICATE 

Changes  to  the  Radio  Reg- 
ulationSr  featuring  the  long- 
awaited  details  of  the  new  "no- 
code"  certificate  known  up  to 
now  as  the  "experimenter's'' 
certificate  and  "packet  radio," 
were  made  public  on  Septem- 
ber 14,  1978.  These  changes 
came  into  effect  September  30, 
1978.  Holders  of  the  new  ticket, 
now  called  the  "Amateur 
Digital  Radio  Operator's  Cer- 
tificate," will  be  permitted 
operation  on  two  meters  and 
above  using  various  modes  of 
operation,  including  pulse 
modes.  They  may  obtain  an 
Advanced  certificate  after  a 
year's  operation  and  passing  a 
15-wpm  coda  test.  Advanced 
amateurs  may  use  pulse 
modes  after  passing  the  rele- 
vant portion  of  the  new  exam. 
The  new  exams  for  all  three 
classes  of  certificates  will  start 
November  15  of  this  year. 

Packet  radio  will  be  permit- 
ted to  all  three  classes  in  cer- 


tain parts  of  the  220-MH2  band. 
Along  with  other  modes,  It  may 
be  used  from  220.1  to  220.5 
MH^.  An  exclusive  two  mega- 
hertz slot  for  packet  radio,  only, 
is  allowed  from  221.0  to  223,0 
MHz.  There  are  no  other 
changes  In  the  220  band  which 
affect  Amateur  and  Advanced 
Class  operators.  Another  ex- 
clusive packet  radio  slot  is 
from  433.0  to  434.0  M  Hz.  Packet 
will  also  be  permitted  on  24.0  to 
24.01  gigahertz.  For  identifica- 
tion purposes,  packet  headers 
will  carry  an  ASCII  mapping  of 
the  catlsign.  Secret  codes  and 
ciphers  are  not  permitted. 
Modulation  techniques  and 
emissions  for  packet  radio  will 
be  determined  by  experiments 
undertaken  by  amateurs 
themselves. 

Pulse  modes  PCS  and  PI  are 
permitted  on  two  meters  be- 
tween 145.5  MHz  and  145.8 
MHz,  and  P0,  PI,  P2,  and  P3are 
allowed  from  434.0  to  434.5 
MHz,  with  P4,  P5,  and  P9  being 
added  in  the  1215.0-  to 
1300-MHz  slot   and    in   bands 


from  2300  MHz  on  up. 

Further  changes  to  the  Regu- 
lations note  that  for  all  classes 
of  certificates,  exams  will  be 
held  four  times  annually,  nor- 
mally in  October,  January, 
April,  and  July.  Separate 
credits  for  code  exams  are 
good  for  one  year,  Muiti pie- 
choice  questions  will  remain 
for  the  Regulations  portion, 
with  narrative-type  questions 
for  the  theory. 

Details  of  the  new  regula- 


tions and  the  examination  re- 
quirements for  all  three  classes 
of  certificates  are  contained  in 
the  new  DOC  bulletins,  TRC  24, 
effective  October  1,  1978^  and 
TRC  25,  effective  September 
30,  1978.  These  may  be  ob- 
tained from  the  Department  of 
Communications  Regional  of- 
fices in  Vancouver,  Winnipeg, 
Toronto,  Montreal,  or  Moncton, 
or  from  the  Telecommunication 
Regulatory  Service  at  DOC  HQ, 
300  Slater  Street,  Ottawa,  On- 
tario K1A  oca. 


Corrections 


Please  pass  this  Information 
on  to  the  good  people  who 
were  kind  enough  to  read  my 
article  "Sleight  of  Hand''  in  the 
August,  1978,  issue  of  73, 

The  circuit  shown  in  Fig.  5 
on  page  77  should  not  be  used. 
This  is  due  to  the  fact  that  as  a 
greater  load  is  placed  upon  the 
output,  the  impedances  of  the 
primary  transformer  windings 
begin  to  change  every  halt- 
cycle.  The  impedance  of  one 
primary  increases,  while  the 
other  transformer  primary  im- 
pedance decreases.  This  gives 
rise  to  a  sharp  drop  in  output 
voltage  as  the  load  resistance 


decreases. 

My  apologies  to  anyone  who 
has  tried  to  make  this  circuit 
work. 

Bob  May  K4SE 
Jonesboro  TN 

We  have  just  received  a 
belated  correction  to  ''The 
Beeper,"  {January,  1977)  which 
should  allow  the  unit  to  func- 
tion as  intended.  It  appears 
that  a  lone  decimal  point  mis- 
placement transformed  C5  to 
0.001  uF  when  it  should  have 
been  0.01  uF. 

Gene  Smarte  WB6T0V 
News  Editor 


278 


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etc.,  etc. 

Authorized  Distributors  For: 

Continental  Spec.  (Breadboarding 

Devices) 
Datak  Corp.  (Photo  Etch  Supplies) 
Vector  Electronics  (Ferf  Board) 
OK  Machine  (Wire  Wrap  Supplies} 
E'Z  Hook  (Test  Clips  and  Jumpers) 

Viait  our  Setail  SlorCj  Open  Daily  at  IQ:A.M. 

MINI  DIP  SLIDE  SWITCH 


7  Switches -SLSO 
5/$7*00 
This  offer  good  thru 
12/31/78. 
Reg.  price — ^$L65  ea. 

47.6  MFD-4500vDC  CAPACITOR 
Ideai  (or  linear  power  . 

supplies.  De  rate  to  approx.       r^^^I^^ 
27S0vDC  lor  continuous  duty,     ^"-^ 
Mfd:  Cornell- Dubilier 
Ship:  Wt.  28  Lbs. 
Dim:  12V2-H  x  8"W  x  4"D 
$30.00  ea.  2/S55.00 

HEAT  SINKS 

6030  B  -  Vertical  Board 
Mount  ForTO~220  J.^ 

Devices,  z^ 

6/$  1.00  m 

6010  B-For  14  &  c^  \     .^ 

16  Pin  DIP  IC's 

lO/Sl.OO 


All  Mercbandtse  New  aod  100%  Guaraiifeed. 
PJedse  m elude  sbjpping  charges  wUh  y&ur  qrder. 


R.W.  ELECTRONICS.  INC. 

3Z03  North  Western  Avenue 
Chicago,  Illinois  60618 


312*248  2480 


INTERESTED? ACTIVITY  IS 

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FOR  COMPLETE  DETAILS 

APTROIM 


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BLOOMINGTONJNDIANA,47401 


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M  COMPLETELY  SCANS  ALL  400  CHANNELS 

■¥  TWO  SCAN  MODES  PLUS  CONTINUE 

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^  STYLED  TO  COMPLEMENT  THE  MEMORIZER 

-^  EASY  TO  ASSEMBLE  INSTRUCTIONS 

DMlgnsd  and  englne«(«d  lor  the  YAESU  FT-2a7R.  Ihs  scannar  fi  Idsal  lor  locotlng 
occupied  chonneli  and  (ocal  rapaaler  (raquenclai.  eipaclallv  while  liavellng. 
Channel  lampiing  occun  In  the  PAUSE  mode  wMh  piagrammable  moflllorlng  time,  In 
the  USTEN  mode,  the  tcannar  locatai  and  lock*  onto  an  occupied  channel  unNI  the 
CONTINUE  Pulton  li  depretted  0(  Itie  channel  remalni  unoccupied  lo(  the  ptepto- 
grammed  period.  Complete  icanner  kit  onlv  $33.99  plut  $I.OO  itilpping  (AZ  retldenit 
add  SI  tax).  Send  your  oFdei  to: 

HOUV  SYSTEMS,  1642  M.  OLEANDER,  TEMK,  AZ  85281        ^H3Z 


KRia 


i^  Reader  Service— see  page  323. 


279 


$95  Stand  Alone  Video  Terminal 


! "  #$;;i<  ■■■  < )  *+ ,  - .  /  U 1 2456739 :  i  < = > ? 
iHBCDEFGHIJKLriNOPQRSTUUyKVZCM^, 
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SCT-lOO  FEATURES: 

iB4  X  Ifi  line  Tormnt  with  128  displayable  fhJirjiders 

I  Serial  ASCII  or  BAUDOT  with  multiple  Bnud  rates 
•  $1S7  Assembled  or  $137  Kit  (Partial  Kit  $95) 

•  Full  cursor  eonlrol  with  scrolling  and  pftging 
.      m  On  board  power  supply 

l\         Call  or  writer  today.  MC/VISA  accepted 

>WIT^Y  rnnp    ^'^^^^^  Nt-ul mn       P.  O.  Biix  4021 10 
z/Aii^Ai^wni;    Dallas.  Texas  7524(1  i2l4i  38B-3859 

I  Overseas  orders  and  dealers  inquineg  welcoinff 


DISCOUNT  SCANNERS 


;  The  "toiKh- 


$  255. 00       y  g^ 


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CHECK.  M,0.,  MASTERCHARGE,  VISA 


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617'545'9700 

Other  Regency  models  at 
similar  savings— send  for  list 

^^Mass.  residents  please  add SVo  fax. 


Trans  Gom 


I/-T35 


Tone  Signaling  Equipment 

FmrntUTtfiW  Ihtf  TG-tB  3u^'Mu4iht9  Tmn*  Encoder 
C«iTtpallbl<  urllh  FX.,  CC  dnrf  i»th«r  tifttmini 

Low  nine  wave  diMtiriLon  nf  \tii  than  1 .5%  THD 

PJtt#  in  rone  clement 

EatcelUnil  Tcni|icralurc&  rrequency  MabiHiy 

Jjo*'  currcni  draw  using  CMOS  IC'f 

|fnmun»ly  to  RF 

Two  wear  Mtirrtmfw 


1^ 


Touch  tone  encod«n  Uom  $29.95,  tou^?h  tone  decoder*  and 
two  lone  fequential  tone  encoderi  and  decoders. 
Ordc!  Uoni  oi  for  funhfi  inkitmaimn  lOfii^ict 


^ 


=- Trans  Com 


f'  O.  Bd%  120.  AJdjwn,  ininort  ftOlOI  ilZ-*?i-6^Z-i 


CONNECTOR  ASSORTMENT 

$25.00  $23.50  ^^^^ 

Postpaid  lots  of  three 

Inctydes;  S  PL259,  5-S0239,  S-UG175,  5-UGI76, 
2  -  PL25e,  I  *  DM,  \  -  M3&8,  2  ■  M3&9.  I  ■  UG2&5. 
I  ^  UG27I,    a  '  PL259PO,    I  -  102 120,    I  -  Llqhit^mq 

M^tef  Qt^r^  &  V/sa  accepttii  /  Sen^  for  Fris^  Cafftiog 


CDAKIT    -<^ 


P.O.  Box  lOI-A  Dgmofii  K  X  0762i 

Circi«  C2I  on   Redder  Service  Card 


REGULATED  POWER  SUPPLY 

•  Fully  regulated,  duaJ  proiecte<i^  13  B  vglts 
•  Illuminated  onyoff  switch 

■  Hammertone  metal  case 


3 3  Amp  (30  Amp  contfnyous}  -  $119  95 

20  Amp  (16  amp.  cont,J  ,*.,,  S74.95 

8  Amp  (6  amp.  cont.)  S39:95 

TIMES  CABLE 

nG-9U*100  murtipJes    Ifie/tt. 

RG-213U  -  (Nt>n -co ntam mating  lacket) 

*}OCr  muJttptes  22«/a 

^^"  Aluminum  Jacketed  nardline  -  75  ohm 
1000'  foHs  orttv  ..,  29c/ft 

PL259  connectors 35/50C  ea. 

or  100/45C  ea   POSTPAID 

UNIVERSAL  TOWERS 

SUPER  DISCOUNTS  — 
S,A,S.E.  Tor  brochure  ^nd  prices? 

Send  S  A  S,E  for  ^dUional  inrormalion.  Include  ship- 

3jng   charges   wiifi   checK   Of    money   Ofde«     '«^t'>!> 

rosideots  add  4  >%  sales  tax) 

JRS  ELECTRONICS  ^'^ 

P.O.  Box  1893— Cincinnati.  Ohio  45201 


PCP"  TVPE ! fl 


piinr 

PfMIK 


Hf  tm-N   itiumit  FllM  littilkf  lili  Ollt^m  Iran  ft\iM  pi|il 

IND  C14tHlCJIl£  N   PHOT(lGliJlP«T  ii^yiirifil 

■■ll  tifithiiiij  uttritb  if 41111  ti  irt    Stiiihril  burti,  brrierii^I  ilE^nr' 


SEE  POPULAR  ELECTRONICS 
FEB  ^78  ISSUE! 


fHtllT  ritM  luii  IKI  lilUIII  fTMEil  E.cEwr  luvii  riirntif  Imb 
Mhlt  fM«l.  f?Ht  p4mI  itulL  t4Bfi«fj  itUcfattt  AKih  1  flRtn 


Small  Pkg.  6pcs  4x6  $5.49 
Med.Pkg.  4pcs  6x9  $6.95 
Large  Pkg.  3pcs  9x12  $7.95 


PCR 


niHii  ami  rtniEn  a 

Pi  Ml   HH 
»A  P2€    KLIU.  Bt       Milt 


ANTENNAS  FOR  ALL  BANDS! 


— £IISE>- 


■^±^ 


LOW  COST  -  LIGHT-  STRONG  -  NEAT*  HIGH  QUAHTV 
SINGLE  6 AND  itantiard  TrinimtEtlnQ  or  rec^vlno  HoMJtantml 
ANTENNAS  lor  AN  AMATEUR  BANDS,  MARS.  Short  Wava. 
SpetJ^I  Ff«{3uen£le3.  POWEH  vp  TO  20O0  walls  -  alt  crm^at  - 
Ai  MAIVCS  -  MODELS  TRANSRECIDTERS!  Wf.  3  it*  wnti 
30  fL  300  <|k.  1«st  D«ai3n  eftdi,  IGi  &■  Cootierwreld  -  IfttuUlM*. 
Mallard  conn«€t«r  wftn  iflrtJllBB  ■rrcitor  -  50  tt.  FOAM  HGS^OU 
mOSU  *t  «IO.OO  Mw^tj  WHJi  PL259  ConnettfM-  .  COMPlCT* 
EL¥  ASSEMBLED  -  RIAOT  TO  PUT  UP  AND  USE]  S*t  tar 
low  tnd  9t  b«n#  ii  ad^DttaWe  to  anj  afaet  trMu  wnhout  t»q4a  or 
njtttBiQ  CFrtq-  elart  hiifcliiill  Can  to*  vvctf  vn  lop  of  ^ji-i^tik- 
kr  ittKLs  ^  ANYWHERE  f<^r  TRUE  CM-POLE  rMWlaa  *  ih* 
STANDARD  or  ALL  RADIO  ANTCIINAS!  POftTABtE  - 
EAST  t«  MOVE  ■.ml  Brcct.  W ral  hwfhroof    -LONli  LlTCs 


SO  reifltar  - 125  ft, 
40  m«t«f  «  6$  rt. 
SO  flitlaf  -  33  ft. 
IS  ni«tar    *  22  tu 


No.  HD-QO  10  rrttter  -  f6  fL  No.  HD^IO 

N<t.  H0-4O  6    m«tw    -  9  fL  H*.  MD*S 

ho  HO-ao  Cntxcni  B-  1?  H,  Ho.CB^O 

No.   HD-IS  4d  in«4ar    7Tn.  No   Hl^>49 


ANT  MODEL  No.  $13,95  fplui]  «2.00  paatJiiia  In  USA. 
{Speckal  Froflj.  S3.0O  more  -  Adw^i*  DiiKct  freq.  In  MHZ  -  2  to 
ISO)  SEND  FULL  PRICE  OR  ORDER  WITH  VISA(Banh- 
tmorlcard)  MAS  TEH  CHARGE  -  AM  EXP  Glwa  Nw.  oiid  Ek. 
Date.  Fh  I-30H-S3G-5333  DAM-6PM,  >iM««1cdBy&.  We  ihJp 
In  2-3  diyi,  Ordier  naw  and  t3«at  pHce  irii:rcaEF     -     FREE 

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D«m.  AT^t^  K««rfiey  ,N«bit»hB.  GB947      f^  Vtf  IS 


iSQNVailVHOJSVNNHlNV 


280 


j^**  Bender  Servtce — se#  pa^ge  323. 


$95  MORSE  TRANSCEIVER 


SEND, 

•  1  to  150  WPM  Iset  from 
terminal) 

•  32  charaeter  FIFO  buffer 
with  editing 

•  Auto  Space  on  word  boundri^^ 

Grid /Cathode  k«y  output 

■  LED  Readout  for  WPM  and 
Buffer  space  remaining 


SERIAL  INTERFACE: 

ASCII  a  10.  300,  600,  1200) 

or  Baudot  {45,  50,  57,  74}  coin p sit ibie 

Simplex  HiV  Loop  or  T?L 
electrical  interface 

Interfaces  directly  with  the  XITEX^ 
SCT-100  Video  Terminal  Board; 
Teletypes*    Models  15.  28,  33*  etc.; 
or  the  equivalent 


-  MR5-100  CONFIGURATIONS:  - 

'  $95  Partial  Kit  {includes  Microcomputer  components 
and  circuit  boards;  less  box  and  analog  components} 

•  $225  Complete  Kit  (includes  box,  power  supply, 
and  all  other  components) 

•  $295  Assembled  and  tested  unit  (as  shown) 

^—  Overseas  Orders  and  dealer  inquires  welcome  i^^ 


COPY: 

•  1  to  150  WPM  with 
Auto-Sync  > 

•  Continuously  computes 
and  displays  Copy  WPM 

•  80  HZ  Bandpass  filter 

Re-keyed  Sidetone  Osc. 
with  onboard  speaker 

*  Fully  compensating  to 
copy  any  'fist  style 


See  your  local  dealer  or 
contact  XITEX*    direct- 

■n 

MC/Visa  accepted 


»XIT€X  CORR 

13B2H  Nt'UtroTi  •    P.  O.  Box  402110 


Seze-  n^oAe  &  Speneet 


Eieeti 


ZOHiCS      i^S39 


1465  WELLS  STATION  ROAD 

MEMPHIS,  TENN.  38108 

PH  (901)  683-9125^685-8461 

Authorized  Dealer 

DRAKE— ICOM^KENWOOD 
REGENCY— TEMPO— DENTRON 

CALL  OR  WRITE 
FOR  BEST  DEAL 


FLV  YOUR  RUBBER  DUCKY  M 

Get  off  the  trunk  lid  and  into  the  best  location 
on  the  car  ,  .  .  the  center  of  the  roof  t  Test^  have 
proven  that  the  low  profile  quarter-wave  whip, 
or  the  rubber-ducky  from  a  Handy-Talkv,  out- 
performs a  5/8  whip  on  the  trunk  Take  advan- 
tage of  the  super  ground  plane  by  converting  to 
the  FLYtNC'OUCKY  magnetic  rr^ount  Although 
designed  specifically  for  use  with  a  H-T,  it  can 
be  used  with  any  mobile  rig.  Ten  second  installa- 
tion. 

FLVING-DlJCkV  rtiagnetic  mount  consists  of; 

•  Chrome-plated  super  magnet  (holds  50  lbs  J 

•  Compatible  coax  plugs  furnished  to  match  rig 
reQuifements,  Specify  BNC,  F  type,  PL259' 
S0239.  For  TNC  Wison  type  add  $3. 

•  Coax  cable  lO^  in.  long. 

FLYING  DUCKY  MOUNT  ANDCABLE. . .  $13  95 
QUARTER  WAVE  WHIP 

(specify  connector) $  5.95 

RUBBER  DUCKY  to  match 

[specify connector) $  7  95 


Ifr^f 


t^PIS 


Bo?^  234 
Middlebury  CT  06762 

(203)_758-9228 


CIRCUIT  BOARDS 


REPEATER  CONTROL 

COMPUTER  PROJECTS 

SENSITIZED  BLANKS 

NEGATIVES/POSITIVES 

PROTOTYPE  BOARDS 

PARTS  KiT 

CUSTOM  ETCH/DRILL 

RCA  1002  MP  BOARDS 

CIRCUIT  BOARD  DESIGN 

PROGRAMMING  PADS 

ART  MASTER  PREPARATIONS 


We  can  supply  many  oi  the  ll«mft  you  nei«d 
10  mak«  a  p-o  bflftrd.  Senct  SASE  +  25  csr^i* 
tor  catalog. 


QC     Stafford 


t^-SSO 


Electronic  Service  and  Development 

427  S.  Benbow  Rd* 

Greensboro,  NC  27401 

919-274-9917  DAY/NITE 

Serving  Amflteurs  Around  the  World 


Send-Receive  RTTY&CW 


'i'':.i'4 


M65K 

$69.95 

KIT 


$99.95 
WIRED 


ALitom^tic  iend  &.  receive:  RTTY  and  CW 

I  Complete  hardy^are  and  software  ptick<ige 
Connects  to  yout  PLT  User  Port  *ind  the  key/head- 
phone \Acks  of  your  rtg 
Ten  message  memortes—ZSS  char,  each 

I  Keyboard  buffeT^aHow^  typing  ahead 

'Uses  L>ulk-ln  PLL  Or  external  TU 
Morse  tratriier — random  S  letter  wordii 

I  Includes  hard^ft^are,  cassette  fi^  manual 

'TRS-80  version  available 

Write  or  call  for  detadled  brochure 

Calif tjrni&  r^SidenlS  iCl<3  e%  t^X 


(nwfti^  ij™op 


Microtronics 


V/SA 


r.O*  Box  74T(S)  •  Kcy«,  CA  95328 
(209)634'8S88  •  667-2888 


Write  for   CATALOG 

CRAMMED    WrTH    GOV'T   SURPLUS 
ELECTRONIC  GEAR  send  sm  for  handling 


•  ARCS  TRANSMITTER— wilb  all  tubes  &  crystal, 
brand  n^w  in  original  carIon.^v^i«r<^,  ......  $12.95 

•  SCR-522  TRANSMITTERmECEIVER— 100-15*  mc, 
crystal  controlled  on  4  chanrte^s,  in  excellenf  condi- 
tion iivith  ^E(  tubes  f18} S2©.50 

•  LM  FREQUEI^CY  METER— Ireqweticy  range  125  20, 
OOQKC,  operates  on  12  or  24  V  dc  with  tubes,  crystal 
St   original   calibration    book,   ex,   cond,,   checked 

oyl. , S54.5D 

AC  POWER  SUPPLY  lor  above  (original) S22.50 

•  HEAOSET,  2000  Onms  with  7'  cord  &  PL  55  ptug, 

new , , .  $3.95 

HEADSET,  low  im{>edanc9  with  chamois  cushions, 

4'  cord  &  plug  eK,  cond , . . , , . , ,  i .  v ^ . .  $2.95 

RUGGED  HEAVY  DUTY  CARBON  HANDMIKE  with 
cord  &  plug,  new S1,SS 

•  All  types  of  transmitiing^  receiving  &  special  pur- 
pose tubes  available.  We  invito  your  inquiries. 

Terms:  F.Q.B.  NYC,  25%  deposit  wtlh  order,  balance 
COD  or  remittance  in  full.  Subjecl  lo  prior  sale  and 
[^^^ce  change. 

G&G  RADIO  ELECTRONICS    ,,„ 

COMPANY    45-47  Warren  St.  {2fid  floor) 
Ph.  212-267  4605  New  Yorh.    N.¥,   10007 


Electronics 


GXRXI 


Furt  ASCII  Professional 
Keyboard  K\U  Model  756 


•  full  128  Character  ASCfl  •  TM-ModeMOS  En^ 
coding  •  MOS/DTiyTTL  Compatible  Output  • 
Two-Key  Rollover  •  Level  and  Pul&e  Strobe  • 
Shift  and  Aipha  Lock  •  Seiectiible  Parity  • 
Positive  or  Negative  Logic  ♦  AN  New,  OEM 
Grade  Cqmponems  •  Gold  Corttact^  Low 
Bounce  Key  Switches  •  Rugged  G- 1 0  frinted 
Circuit  3oarcl  •  Low  Power  Consumption  ,  ,  , 
and  More 

Model  756  Keyboard  Kit  S64.95 

Model  701  Plastic  Enclosure  SM.55 

Model  702  Steel  Enclosure .     .%19.^5 

S«nd  lor  cjitalogue  at  other  NEW  merchendlse. 
SemiSt  Sockets,  ICs,  Res.,  Caps,  Anil  MORE 

N.Y.S.  Residents  Add  4%  Sales  Tax 


Send  to;        Key  ilectronlcs 
P.O.  Box  350a 
Schenectady,  NY  12303 


i^Kl4 


f/^  Header  Servfce — see  page  323. 


281 


MFJ  INTRODUCES  A  NEW 

24  HOUR  DIGITAL  CLOCK 

with  HUBE  1-5/8  inch  digits  that  you  can  i(eep  set  to  GMT. 
Alarm  and  snooze  functions  let  you  use  it  as  an  ID  Timer. 
Assembled,  too! 


MFJ  Enterprises  brings  you  a  new  2A  hour 
diglta!  alarm  clock  with  HUGE  1-5^8  Inch  orange 
7  segment  digits  that  you  can  mb  clear  across 
ttie  room. 

Ttiis  one  \%  strictly  for  your  ham  shack,  one 
ttiai  you  can  ^eave  set  to  GMT.  No  more  menial 
calculations  to  gel  GMT, 

Use  till!  aJanrt  to  remind  you  ol  a  SKED  or 
witti  the  snooze  function  as  an  ID  timer  to  buzz 
you  in  8  minute  mtervals. 

A  constantly  changhig  t^aleidoscopic  pattern 
indicates  continuous  operation. 

Beige,  2  1M  x  4-1/8  x  8  3/4  mcties.  UL  lisfed. 
1 20VAC,  60Hz. 

Order  from  MFJ  and  try  rt  -  no  obHgation.  tf 
111  del^ohied,  return  it  wittiin  30  days  for  a  re- 


lund  {less  shipping).  One  year  limited  warranty 
by  MFJ  Enterprises. 

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— »  1 


How  You 
Can  Convert 
Your  Rohn 

25G  Tower  to  a 
FOLD -OVER 


CHANGE,  ADJUST  OR  JUST 
PUIN  WORK  ON  YOUR 
ANTENNA  ANO  NEVER  LEAVE 
THE  GROUND. 


If  you  have  a  Rohn  25G 
Tower,  you  can  convert  it  to 
a  Fold-over  by  simply  using 
a  conversfon  kit.  Or,  buy  an 
inexpensive  standard  Rohn 
25G  tower  now  and  convert 
to  a  Fold-over  later. 

Rohn  Fold-overs  allow  you  to 
work  completely  on  the 
ground  when  installing  or 
servicing  antennas  or  rotors. 
This  eliminates  the  fear  of 
climbing  and  working  at 
heights.  Use  the  tower  that 
reduces  the  need  to  climb. 
When  you  need  to  ^^get  at" 
your  antenna  ,  ,  ,  just  turn 
the  handle  and  there  it  is* 
Rohn  Fold-overs  offer  un- 
beatable utility. 

Yes!  You  can  convert  to  a 
Fold-over.  Check  with  your 
distributor  for  a  kit  now  and 
keep  your  feet  on  the  ground. 

47"  ROHN  YOU  GET  THE  BEST 


Do  not  attdfnpt  to  raise  antonna  or 
antenna  support  near  power  (ifies  — 
You  can  be  KILLED. 


Unarco-ltohn 

FO  Box  2000.  Peoria.  niinoaetGOl 


^m 


$^  Reader  Service —see  pag€  323. 


283 


1978  Index 


ANTENNAS 

Tune  Your  Tower  To  80/160. K9S0G 

The  Extreme  Basics  of 

Antennas , . ,  . . .  K4SE/WA4DBG 

The  $5  Magnetic  Mount WA2UMV 

Keeping  the  Zap  Out  of  the  Shack ,  W7RG 

Can  A  M miature  Antenna  Work? W6AQM 

The  Powerful  Grounded  Antenna W0SII 

Meet  the  Plastic  Wonder K0OXB/5 

A  2m  Antenna  for  the  Perfectionist. WB2AWG 

A  Brass  Horn  ForX-Band.. W1SNN 

Extended  Double  Zepp W6TYH 

New  Dipole  Feeder AA6AX 

The  Cliff-Dweller's  Detight WA2UVC 

Wait  Til!  You  Try  16  Elements! WA8FCA 

Working  15m  With  A  20m  Beam W8ZCQ 

A  Better  Feedthrough  For  Cables, WA8FCA 

Resurrecting  The  Beverage  Antenna ,  W5USM 

How  To  Hang  A  Longwire W5GN 

The  '^German"  Quad WD4CPK/DF3TJ 

Mobile  In  Disguise. K9MLD 

Better  Than  A  Quad . , WA4NWW 

The  Perverted  Double  Vee  Antenna VV5VSR 

Towering  Low  Band  Antennas K3QQF 

The  80  Meter  Pile  Crusher W20ZH 

Phased  Verticals  For  Easy  DX W1ZY/LA(DBP 

The  Miserly  Magnetic  Antenna . , . .  W2AZD 

The  75m  DX  Chaser  Antenna ...,,.,....  N4VD 

The  Invisible  Allband  Antenna. . .....  WA4FYZ 

Who  Says  Verticals  Donl  Work?, W2LFJ 

New  Use  For  CB  Antennas. WA2KBZ/JY9KS 

Confessions  Of  A  Vertical  Fanatic. .,,...  KH6HDM 

The  21 -Element  Brown  Bomber W9GGI 

The  Two  Hour,  Two  Meter  Beam, WB9TNW 

The  OSCAR  Boppers G3ZCZ/W3 

The  S-Meter  Bender . , W8HXR 

Amazingly  Simple  Log  Periodic  Antenna. . .  K1QAR 

Disguised  Birdhouse  Vertical K5LUW 

Enjoy  All  Five  Bands. ......_ W8FX/4 

Novice  Guide  To  Phased  Antennas. .,...,.  W8HXR 

The  PVC  Portable WA6RJK 

The  Swiss  Fork  Special , Staff 

The  Sneaky  J \ W8FX/4 

High  Q  Antennas. K4KI 

The  Ten  Meter  AM  Antenna  Special W6RCL 

Antenna  Design:  Something 

New! W4FD,   W4ATE 

The  Schizophrenic  Triangle. ,...,..,,,...  WA4JTJ 

CALCULATORS 
Negative  Numbers  On  A  $9  Calculator. . .  WB6IXT/7 
The  Experimenter's  Dream  Calculator Reid 

CB 

The  Ham  CBer. .... . . ,  WA4BaU 

CB  to  10— part  VIM:  the  Publicom  I WB6LQE 

From  CB  To  Amateur  Radio. WB4P0H 

How  About  SSa  CB  Conversions?, W4GBB 

What?  CB  Repeaters?! , WA4E0X 

CB  to  10— part  IX:  a  pair  of  Radio  Shack 

CB  to  10— part  X:  Reaiisttc's  Mini 

23 K5LUW/K5SA 

CB  to  10— part  XI:  Hy-Gain's  PLL  rigs. . . .  WB58SG 
CBto  10— part  XII:  convert  aKraco  PLL  rig, ,  .W1PI 
CB  to  10— part  XIII:  the  Lafayette 

Telsat DF1SP/W2 

CB  to  10— part  XIV:  a  Realistic  PLL K0QLC 

CS  to  10— part  XV:  a  Realistic  HT K5UKH 

CLOCKS 
The  "Do  ft  All"  Digital  Clock- , K6UGT 

COMMERCIAL  GEAR 

Reprogram  Your  IC-22S. , W6UTE 

Simple  Scanner  For  the  10-223 KH6EM 

Improve  the  AX-190  Receiver WA3TLD 

I  Love  My  GTX-1 WA4H VH 

Heath  HT  Goodies. WA1 IZS 

Drake  TR-4CW  Review , K4TWJ 

The  Tempo  2020, WA2K0K 


118 

Jan 

116 

Feb 

118 

Feb 

130 

Feb 

160 

Feb 

26 

Mar 

58 

Mar 

154 

Mar 

164 

Mar 

34 

Jun 

38 

Jun 

40 

Jun 

42 

Jun 

46 

Jun 

50 

Jun 

52 

Jun 

58 

Jun 

60 

Jun 

62 

Jun 

64 

Jun 

66 

Jun 

74 

Jun 

76 

Jun 

82 

Jun 

86 

Jun 

88 

Jun 

92 

Jun 

96 

Jun 

122 

Jun 

134 

Jun 

140 

Jun 

154 

Jun 

160 

Jun 

170 

Jtin 

174 

Jun 

178 

Jun 

32 

Jul 

48 

Jul 

49 

Aug 

90 

Aug 

160 

Aug 

68 

Sep 

146 

Sep 

282 

Oct 

44 

Dec 

32 

Jan 

114 

Apr 

172 

Jan 

98 

Feb 

114 

Mar 

96 

Jul 

34 

Aug 

78 

Aug 

138 

Sep 

172 

Sep 

254 

Oct 

86 

Nov 

120 

Nov 

238 

Nov 

176    Aug 


54 

Jan 

74 

Jan 

106 

Jan 

150 

Jan 

180 

Jan 

30 

Feb 

48 

Feb 

Put  A  Sony  In  Your  Shack Staff 

Don't  Miss  the  Excitement  of  QRP K9SGZ 

Wireless  Monitoring  For  the  Bionic  Ham. . .  W8FX/4 

The  Go  Pro  HT  Mod. ,....,,.  W8FXM 

Good  Grief,  Not  the  22S  Again?. . , WB2LEI 

Improve  Your  HW-2021. , K1WXK 

The  IG-102  Goes  Transistor. .. Rossnick 

No,  Not  Another  22S  Mod? VE2TM 

Cushcraft  Does  It  Again!. .,.,,...... K10PQ 

Can  A  $20  FM  Rig  Work?, ......  WB4LJM,  WA4WDL 

Hiss  Exterminator * K9P0X 

The  FM  Rebroadcaster.  *..,...,..........  W8FX/4 

22  Remote. , , W8FX/4 

The  IC  22S  Scanner. W9LI J 

A  Much  Needed  Micoder  Power  Supply K3MPJ 

Sometimes  A  Kit  Is  Best. W6SWZ 

Rock  Steady. ,.  WA5R0N 

Updating  the  Wilson  1402 WA9RAQ 

HW-101  Owners,  Check  This! HB9SLU 

The  Toggled  22 Fletcher 

The  End  of  Autopatch  Embarrassment W4CUG 

Another  IC-22S  Scheme. WA1ZMQ 

Improving  the  SWTPC  UDI K3MPJ 

When  In  Doubt,  Improvise! W6LTV 

The  Case  of  the  Missing  Off  set K3JZD 

What  Do  You  Do  With  ATimekube? Staff 

Another  Trick  f©rthe223 WB7SHW 

MicoderTM  Magic K4BJF 

Mighty  Mods  for  the  820S. .........  K4FK,  WA4KIL 

Improving  Heath's  HT WA6TLK 

Oddball  Splits  and  the  IC-22S W6YUY 

Triple  Threat K3CMY 

Two  Meter  HT  Survey K5XY 

Happiness  Is  A  Smart  Scanner K8JS 

Improved  Scanner  for  the  VHF/One  Plus. . .  W7AAY 

Further  Adventures  of  the  IC-22S , , .  W6WUT 

The  Multifunction  Scan  Can W1IBI,  W1HZH 

Happiness  is  a  DMM  Kit W7AAY 

Deep  Dark  Secrets  of  the  TR-7500 WB9SEQ 

Heath's  GR-88  Gets  Rengiont W2AQ0 

Wow!  A  Good  Portable  Receiver! WA2EJT 

The  XITEX  Video  Terminal AH6AQ 

Light  Up  Your  Life WA4NUE 

The  22S  Goes  Digital. KH8IEL 

CONSTRUCTION 

Forget  Ohm's  Law Stanf ield 

Build  A  Deluxe  QRP  Transmatch WB4VLQ 

Dodge  That  Hurricane! WB4IXK 

New  Life  For  Old  Transformers WA7NEV 

Cool  It'  K4KI 

Build  A  Simple  Capacitance  Meter. , W8DCC 

PC  Techniques Staff 

Inexpensive  EKG  Encoder. WA3AJR 

Build  A  Better  Phone  Patch. ,  Poirier 

Build  A  3-1/2  Digit  DVM. WA5VQK/5 

Tune-Up  Aids  For  the  Blind — ...  WB1FFQ 

Measure  Periods  With  Your  Counter. , , 

The  Overkill  Stall  Warner..* 

Flash  Project  For  Camera  Fiends, ..... 
The  Solar-Powered  Ham  Station. ...... 

A  Cheapskate's  Circuit  Board 

Build  This  Digital  Ball  Game- ...... 

In  Search  Of  the  Ultimate 

Super  Deluxing  the  TR  33 WA6JFP 

Hey,  Old'Timers!  The  Breadboard  Is 

Back! WA7NEV 

The  COR  Goes  Solid  State WA6ILQ 

Enjoy  All  Bands  With  A  Remote  Tuner. . KL7AE 

Counter  Accuracy  For  Perfectionists K&KDT/5 

Graduate  to  a  Better  Operati ng  Desic. WB6EK0 

Relief  for  the  Rockbound WB2EQG 

The  ARC  Tuner K9QLL 

Buddy,  Ya  Got  A  Match? , K4KI 

"Stop Timeouts!*'  Revisited WB3ELV 

Add-A-Scanner N2YK/WB2NyK 

The  Circuit  Board  Aquarium WB9QZE 

Build  a  Realistic  S-Meter. DJSNW 

Build  the  Flexi-Filter. W3QVZ 

The  Klassic  Kilowatt K4TWJ 

Code-Practice  Oscillatofs. W6GXN 

PCs  Are  Easy. VE3CGE 


,  K6MWM 
..W9CGI 
WA6UNK 
..W5VB0 
WA1BVD 
.  ,.N2RG 
. .  W6YUY 


CONTROL 

Simple  Sequential  Decoder 

The  World  Of  Tone  Control. 


W7JSW 
.  K3JE/2 


102 

62 

134 

152 

172 

130 

120 

158 

166 

52 

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148 

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214 

48 

54 

64 

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206 


46 

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62 

70 

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40 

64 

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66 

72 

46 
162 
118 
76 
48 
74 
128 
152 
168 
116 
240 
126 
222 
226 
256 
270 


166 
82 


Feb 

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Sep 

Sep 

Sep 

Sep 

Oct 

Oct 

Oct 

Oct 

Oct 

Oct 

Oct 

Oct 

Nov 

Nov 

Nov 

Nov 

Dec 

Dec 

Dec 

Dec 


Jan 
Jan 
Jan 
Jan 
Jan 
Jan 
Jan 
Feb 
Feb 
Feb 
Feb 
Feb 
Feb 
Mar 
Mar 
Mar 
Apr 
Apr 
Apr 

May 

May 

Jun 

Jul 

Sep 

Sep 

Sep 

Sep 

Sep 

Nov 

Nov 

Dec 

Dec 

Dec 

Dec 

Dec 


Jan 
Mar 


284 


Fake  'Em  Out  With  Remote  Control W4VG2 

The  Miser's  Delight  Repeated  Controller. , .  W2PMX 

Give  'Em  A  Break .... WB6JPI 

Should  Repeaters  Use  Subaudibfe  Tones?. . . .  K9XI 

Power  Line  DX ,. , N2CX 

Hung  Up  On  Autopatch? V\/A6THG 

The  Tiny  Tone  Repeater  Saver W4VGZ 

The  Autodialer  Revisited, , .. W7JSW 

The  Easiest  Offset  Ever. K4GOK 

Automatic  Repeater  Offsets. ......  N2yKyWB2N VK 

The  2Sc  TouchtoneTM  Mod .  W9CGI 

SSTV  Recorder  Controller. , , ,  K3JML 

COUNTERS 

VHP  On  Your  Frequency  Counter WB0CLH 

Good  News! Lassagne 


CW 

Brass  Pounding  Simpltfled 

Simple  CW  tnterferer^ce  "FIfter" 


•  m  i«^  .« .  K6JM 

W8FX/4 


You.  Too,  Can  Go  DigitaL .  -  - 

The  Best  Probe  Yet? . . . 

A  Darn  Good  IDer 

Time  and  Tide— Digitally. . . 


DIGITAL 

......  WABJMMmeWA 

. . .  K50M 
.^WAITNG 


!§      -«      i-      -I       ^      S      tb 


I       ■■      P      ■■      «■ 


»      »     «     «     4 


ri    4    'i    p    «- 


..W1HCI 
.  W7RXV 
..K3Je2 
WA4GIM 
..W6NUI 
..WlOiS 


GADGETS 

The  Trailer  Light  Solution. 

Custom-Made  Thermistors, . . .... 

^hJ'U  LrfT  t^  I  ^J  I  I    ^^  II-      -  r      *      t,      M     M      ,M      m>      *      «      *      !!■»■■      -P      9      *      *     ^      M:     *      m       «      ■' 

New  Protect  ron  For  Your  Car. .... 

Kerchunk  Counter ...,,,..,, 

Shock  the  Car*Burglar. , , , . . 

The  Super  Setect-o-Ject. , , W8FX/4 

De-Zap  Strap W6SWZ 

The  New,  Improved  Automatic  Thermo- 
stat  W9YBU 

It's  Flora  Clocki , W8FXy4 

Computerized  Capacity  Meier. Eccleston 

The  Universal  Notcher W9CGI 

Beat  the  Microphone  Biahs. K1 HQW/4 

Roy  Rogers  Special:  Triggered  Sweep.  ..*..,  Reoaud 

Watch  the  Wind*. ....... WA4FWH/5 

The  Op  Amp  Beam  Heading  fndrcator. K0BV 

Watergate  Special , . . . ,  HB98tU 

Be  Mr.  Clean! WB4FXD 

Maintain  Control!.  .....**....... .....  Stanfield 

Active  Voltage  Divider PY1AQUCT1EM 

Light  Right? Mills 

Build  A  Better  Beeper, W3QVX 


HISTORY 

11  ow  n  was,  ..1 ,-.---,...  w ■, %  -r  *  t -^ ^  ^ , ^ ^ 

The  H  istory  of  Ham  Radfo— part  VI 

The  History  of  Ham  Radio— part  VH 


W6LM 
.W9CI 
.W9CI 


HUMOR 

I  Need  A  Contact , WB2DYU/2 

Murphy's  Masterpiece WA6PPZ 


IC 


W7BBX/4 

........,.W3HB 

K4IPV 


WA2SUT/NNN(5ZVB 


1 69I    I  rl05c  ivSi.  ...V........ 

IC  Timer  Review , ... 

The  Op  Amp  Encyclopedia. . . 
How  Do  You  Use  ICs?— part 
IX, ,,__ ._ , . 

Is  TTL  Already  Obsolete? , ....  WB5IRY 

Schottky:  A  New  IC  Generation McClellan 

The  New  Op  Amps WAOUVX 

How  Do  You  Use  ICs?— part 

X, , .,, .  WA2SUT/NNN€2VB 

Build  the  IC  Experimenter, . . - .  Leonard 

The  Long-Term  Effects  of  Working  with 

ICS . .  - , . .  WA2SUT/N N  NOZVB 

Bargain  Preamp. W5REZ 

555  Basics—And  More! WB4CE0 


I/O 

To  Err  Is  Human. —  . 

Practical  Computer  Projects . . . . 

You'll  Like  SOL! * . 

How  To  Keep  Your  Computer  Happy. 
The  Bionic  Clock!.  ,...,*... . , . 


. . .  WB2T0C 
, , Mickle 

,...WB6JYK 
. . .  WD9DDV 
W4CQI 


52 

124 

62 

102 

52 

112 

132 

32 

34 

74 

82 

56 

82 


32 

134 
142 
156 


50 

50 

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143 

185 

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60 
64 
S8 
S8 
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142 

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102 


May 

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44    Oct 


58    Feb 
132    Apr 


Mar 
Apr 
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Aug 


Feb 
Feb 
Feb 
Mar 
Mar 
Mar 
May 
May 

Jul 

Jul 

Jul 

Jul 

Jut 

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Jul 

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152  Jan 
68  Oct 
90    Nov 


138     Mar 
48     Nov 


24   Jan 

40    Jan 
166    Feb 


Apr 
Apr 
Apr 
Ju 


44 

120 

158 

78 


94  Sep 

220  Sep 

182  Oct 

44  Nov 

60  Nov 


Jan 
Jan 
Jan 
Jan 
Jan 


.  K4HBG 
. . K7SBK 

WA5JSF 

. .  W4KFT 
,  W6GXN 
, . Lasher 

, .  Stewart 
Eaton 


w    d     n    * 


KIM-1  Can  Do  ItL W4CQI 

A  Secret  Weapon  For  Road  Rallies. , , .  K9PTI 

Looking  For  A  Micro?. O'Reilly 

Fiendish  New  QUBIC  Program. ... ....  Bishop 

Put  An  ELF  In  Your  Keyer. , WB9MQY 

Try  HCAI. Hughot 

Solve  Those  Parallel  Problems N3IE 

At  Last!  An  RFIfree  Computer.... ....  WB6JYK 

Another  Approach  To  the  ASCII/Baudot 

Programming  CoM  Design 

Outstandmg  Computer  Bargain 

Do  Biorhythms  Really  Work? 

Feeding  A  Hungry  Microcomputer. ...... 

The  Exterminator .,,....,.,., 

At  Lastl  A  Use  For  Your  Computer!. . 

Now  Anyone  Can  Afford  A  Keyboard. . .. 

Godboul  Strikes  Again. WA7NEV 

The  Kllngons  Are  Comingl. WB9LSS 

Diary  Of  A  Survivor , ,  — WA6PPZ 

How  Good  Is  the  North  Star  Disk?. ...,,,..,.  Bosen 
Pseudorandomness  Is  Just  Not  Good 

Enough. WA1 PTZ 

Beethoven  Need  Not  Fear. G8HBR 

Hex  Converter  For  True-Blue  Octalists Pol  i  near 

The  Cheaper  Beeper VE2SVW 

Semi-Instant  Program  Loading WB4GXE 

Low-Cost  Keyboard-  II Eaton 

Computerized  Loop  Antenna  Design, .....  WB2IPD 

He'^l  Wail  For  Me! .., **.. WA3MWM 

Morrow's  Marvelous  Monitor. .*......  Eigsti 

RAMmed  by  Morrow. Hallen 

Six  Said  His  First  Words  Today!. .......  WA3MWM 

The  22s  Programmer  Program. . , ,  W60VP,  K6MAR 

The  Occult  Computer.  ,....*,, .,...,  WA6VIY 

A  Baudot  Program  For  Your  Micro Fricke 

The  Kalcufating  Kl M-1 Lasher 

A  No-Cost  Digital  Clock N8RK 

The  BASICS  of  L-Network  Design K7SBK 

Nuclear  Attack!. . , WA7WKA 

Computerized  QSO  Records WA7VZR 

RAM  Checkout's  A  Snap .........  WA7NEV 

Interrupts  Made  Easy. WB6L0A 

Use  A  Computer?  Who,  Me?. , . . , WB2H  JD 

Bird  Watching  in  BASIC  Land .  K6EW 

Computers  and  the  Real  World , , . .  W1 FZA 

World's  Cheapest  QSLs. . . , WA7VZR 

"Look  What  Followed  Me  Home!** LIlie 

A  Hex  on  Your  6223. Schneider 


p  V  »  1 


The  Micro  Maestro!.. 

SSTV  Meets  SWTPC:  Part  1 .... 

Whither  Microcomputers?. .... 

SSTV  Meets  SWTPC:  Part  2 

A  Multt-Memory  Morse  Machine, . . , 

*'This  is  Your  Computer  Speaking" ....  Sorrels 

RTTY  with  the  KIM. .................. VE1 AKL 

DX  Delight , . . .  WA4VQD,  N3NN 


. . . .  K6EW 
...K6AEP 
,WB2HJD 
...K6AEP 
.  WA8TIW 


KEYERS 

Try  A  Sensor  Keyer. , ...,,.,*. 

The  New,  Improved  "Best  Keyer  Yet'\ 
Novices,  Paddle  Your  Way  To 

Happiness. ...... . 

A  Keyer?  Who  Needs  Another  Keyer?. 

The  $5  Memory  Keyer.  - .  - ...,.,, 

The  Heavyweight, 

Sidetonels AMust. .....  — ....,..,. 

Custom-Make  Your  Key  Paddle. ....  * 

Build  the  Triple  Threat  Keyer. . 


.WB4TED 
K4JEM 


ri       I        i      -i 


■w     *      ■*      * 


..W0OGX 
. . .  W6APZ 
.  WA2EBY 
....K9MX 
..VE3EKR 
....W6JB 
,.W8FX;4 


MISC 

The  Unbeatable  Base-Loaded  Three-Element 

Rotary  Vertical. .**.  ♦  - . .  W3KBM 

Hooking  the  Kids * Di Blast 

Home  Brew  An  Elephant! WB6iQS 

Grow  A  Giant  Junk  Box!.  .,.•,, WB7CTH 

Is  It  Glass  . , .  Or  Iron? ....  WA2SUT/NNNiBZVB 

Raid! * .,.- W8JJO 

See  Q,  See  Q ..........,,.,,. VE3FLE 

Coming  of  Age. — VE3FLE 

How  To  Compete  With  An  HT VE7AQS 

S.A.S.E. W9CGI 

A  Ham's  Life  Cycle VU2JS 

How  To  Dissipate  200.000  Megawatts W4NKV 

The  Great  Cover-Up. . , W4FXE 


68 
72 
76 
78 
82 
84 
88 
92 

96 
98 

104 

110 

76 

84 

88 

92 

102 

104 

92 

100 

103 

106 
110 
111 
112 
100 
108 
111 
114 
110 
112 
114 
116 
118 

too 

106 
10s 
100 
106 
112 
146 
154 
156 
161 
166 
142 
148 
150 
168 
148 
152 
160 
164 
170 
174 


44 

24 

100 

74 
128 

15D 
144 


22 
114 
146 
158 
160 

88 

90 
100 
110 
112 
114 
153 

78 


Feb 

Feb 

Feb 
Feb 
Feb 
Feb 
Mar 
Mar 

Mar 
Mar 

Mar 

Mar 

Apr 

Apr 

Apr 

Apr 

Apr 

Apr 

May 

May 

May 

May 

May 

May 

May 

Jun 

Jun 

Jun 

Jun 

Jul 

Jul 

Jul 

Jul 

Jul 

Aug 

Aug 

Aug 

Sep 

Sep 

Sep 

Oct 

Oct 

Oct 

Oct 

Oct 

Nov 

Nov 

Nov 

Nov 

Dec 

Dec 

Dec 

Dec 

Dec 

Dec 


184    Jan 
22     Mar 


Mar 
May 
Jul 

Aug 
Aug 
Aug 
Sep 


Jan 
Jan 
Jan 
Jan 
Jan 
Feb 
Feb 
Feb 
Feb 
Feb 
Feb 
Feb 
Mar 


285 


Are  You  Afraid  To  Build?  ,,,,,,, 

Can  A  Diode  Replace  A  Relay?, . 

If  You  Want  To  Know  Where  You  Are. 

CWthe  Hard  Way , 

Why  Not  Go  First  Class''. 


,  W4RY0 
,  *  + .  oi  a  ii 
Burhans 
. .  Pel  ton 
W9C6I 


Another  Ten  Minute  Timer?. . .  N9MX,  K9MX 

[f  You  Want  To  Know  Where  You  Are, ,  _ , .  Burhans 

Scare  the  Hell  Out  Of  Burglars. WA6WUt 

Happiness  ts  Being  A  Ham 

Manufacturer W2NSD/1 

Creeping  Crud  Got  Your  Signal?p . , K4TWJ 

Modernize  The  Matchbox, ,,..,,...,., W8FX/4 

The  Towertess  "Tower*" K4FK,  N40G 

Finding  Radio  Pests.,..,. WA1UUK 

Video  Magic  For  Your  Home, ,  ,,4. -,.-•-,..  K4TWJ 

Instant  Engraving , .  W7RXV 

J.  B*  Fields.  Radioman WB7SZC 

Handling Ole George K5GNZ 

Forbidden  Contacts. ...,.,.. -^.. •.-..* Nobel 

Instant  Paddle W3IH A 

The  War  Against  Rust. K8AO 

Radio  Row  Revtsited. W8JJ0 

Shockl!. ...., McAlrstef 

Sleight  of  Hand. ..............._.  K4SE 

2001  -  3.  * ....  - ,♦..♦..,*,.......,...  WA5SNZ 

Dispense  I!  Right! W4RY0 

Ham  Radio  Is  NOT  A  Rich  Man's 

Hohhv  WAfiNnx/1 

Poor  Man's  Cruise  Controi. -  W9CGI 

Be  Legal. „  AD4A/W A4M FY 

The  SWL  Bible. W2XQ 

Relax  and  Unv^md , .  WA4TJ J 

Home- Brew  Circuit  Boards W9IWI 

Kerchunk  ,  . .  Kaboomt . . ...,.,..  N5KR 

The  KM1CC  Story. WAI JWD 

Reusing  Coax  Connectors W0FEV 


,WA7NEV 
WN3NNY 
..VE3FLE 


Building  From  Magazine  Articles 

Hello  Hamdoml 

More  "'Coming  Of  Age" 

High  Seas  Adventure— Ham  Style- 
part  L  . . , WA6FEI 

DMM  Buyer's  Guide ...*♦,. »  McCfeilan 

The  Ultimate  T-Hunt WB6JPI 

It's  A  Ham's  World. .......................  K2HTO 

Tuned  Circuits  In  Your  Junk  Box W3KBM 

Electro  Sculpture* VP2DN 

Sifence  Groaning  Refrigerators* K4K1 

How  About  Some  Ham  Shack  Safety? W7FGD 

Who  Uses  All  Those 

Frequencies? WS6JPI,  WB6HDB 


«      !       I      V      4 


I    i    4    ft   -i    ^    # 


,  Edwards 
WA4DQN 
,  .WB5ILK 


,  _  WA6FEf 
.WA1PDY 
,,.W20LU 
, , , . ,  K4S  E 

N4AL 

...KSNQN 
....K4IPV 


MDS:  What  Is  It?. .... 

The  Junk  Box  Station. 

R-X  Bridge  +  Calculator  =  Vswr. ... 

High  Seas  Adventure— Ham  Style— 

Squelch Ifying  Cheap  Receivers 

Vintage  Receiver  Mods. ............ 

Using  Bar  gain  Muff  m  Fans 

Ham  HelpL* 

Close  Encounters.  ..,-.i.        ...... 

Receiver  Diseases 

Htgh  Seas  Adventure— Ham  Style- 
part  m, WA6FEI 

The  Packet  Radio  Revolution VE2PY 

WARC  79  Preview, WA9MZS 

Ham  Radio  Goes  to  School. N2CF 

The  Games  People  Play , WB3EUG 

An  Improved  HV  Tube  Socket Miller 

MOBJLePORTABLE 

Hands-free  Mobiie  Mike. ........_  W9KXJ 

The  Double  Whammy  Mobile  Glarifier K8JS 

The  Amazing  Mobile  Lite  Preserver W2EVM 

The  Mobile  Dream  Machine. .,. ..... K9SQG/8 

Mobile  Security  Blanket, .... ....  WA1RTD 


OPERATING 

Guilty?  Or  Not  Guilty? 

Where,  Oh  Where —  . , . . , 

Shoestring  Switching  For CW. , ..... 

Relaying  For  Fun  And  No  Profit ....... 

Repeater  Procedure 

How  To  Work  Europe  With  An  HT. ...... 

Ruddy  Good  Show* ........... 

The  End  of  the  Rat*s  Nest. ..,-... 

Four-Wheel  Frenzy!. ...... 


. .  WA6HDK 

W2XQ 

...Baldwin 
.....  N2RG 
..WB4NAY 

N2MW 

. .  WB9PYM 
....  G3WDt 
..WB9FRM 
.....K6WS 


156 

184 
106 
178 

84 
128 

146 
160 

30 

72 

84 

146 

42 

44 

58 

74 

84 

136 

170 

176 

26 

44 

76 

94 

141 

142 

184 

40 

50 

98 

132 

140 

38 

72 

74 

102 

103 

112 
126 

136 
210 
256 

32 
42 
52 

104 
106 
126 
130 

136 
182 

210 

276 

286 

36 

90 

142 
192 
212 
230 
274 
287 


69 
138 
32 
34 
52 
54 
2n 
58 
92 
26 


Mar 
Mar 
Mar 

Apr 

May 

May 

May 

May 

Jun 

Jun 

Jun 

Jun 

Jul 

Jul 

Jul 

Jul 

Jul 

Jul 

Jut 

Jul 

Aug 

Aug 

Aug 

Aug 

Aug 

Aug 
Aug 
Sep 
Sep 
Sep 
Sep 
Sep 
Oct 
Oct 
Oct 
Oct 
Oct 

Oct 
Got 
Oct 
Oct 
Oct 
Nov 
Nov 
Nov 

Nov 
Nov 
Nov 
Nov 

Nov 
Nov 
Nov 

Nov 
Nov 
Dec 


Dec 
Dec 
Dec 
Dec 
Dec 
Dec 


!78  Jan 

168  Apr 

51  Aug 

58  Sep 

270  Oct 


Jan 
Jan 
Feb 
Feb 
Feb 
Feb 
Aug 
Aug 
Aug 
Sep 


Tracking  the  Wild  Turkey .,.._...  WA8BHR 

Meet  Mr.  Biiz2ard. . .  K8YQH7AA8P 

The  BIrzzard  of  78. W8HXR 

Two  Meters  At  the  Summit, , W6FJT 

DXpeditioning WA2VMS 

The  Lady  Saw  Red WB4ZVZ 

Tweaking  Your  Linear , . . , W5VSR 

Support  Your  Local  Fire  Chief W1 FYR 

Try  FM  On  29,6  MHz.  ...*..... , WA7WYF 

Automatic  Autopatch W6GJS 

A  DXer's  Dream  Vacation WB6JPZ 

POWER  SUPPLIES 

Power  Suppfy  Regulation . ..,...,,, WA3TLD 

How  To  Cut  Costs  On  Power  Suppfies. ....  W9HDA 

Surprisingly  Low-Cost  Latj  Supply W6GXN 

Avoid  An  Overvoltage  Catastrophe, W7RXV 

Coming  In  Out  Of  the  Cold. W6GXN 

In  the  Eye  of  the  Beholder WB6JYK 

Super  Charger WA7YGB 

Don  t  Let  Your  Battery  Die WB8TXG 

Power  Supply  Magic. Burt 

Charge! W4VGZ 

The  Frugal  Aiternative. ....... . . .  W8FX/4 

A  Perfect  Power  Supply?. ,  WB3BUU/8/KSUR 

Build  the  Brute , , . . , .  N9KV 

Four  Terminals  Are  Better  Than  Three. .  _  .  W1SNN 

roll'  OCi   1^.*.......      ,      .m-m-r      *....*.*..     ...... ...^         W  r\  f    %J  f       f\ 

RECEIVERS 

0(d  Receivers— A  Hidden  Gold  Mine W6GXN 

Build  This  Excitingly  Simple  Receiver. K4DHC 

Build  Your  Own  Digital  Dial. W1  OOP 

RTTY 

On  Your  Mark! WA4KIL,  K4FK 

The  UART  Gear  Shifter KB8CE 

Novel  RTTY  Autostart. K20AW 

No  More  Excuses!. WB4MBL 

Build  the  "Version  Three' Colby 

Blockbuster  RTTY  ArtJcleL W9IF 

SATELLITE— OTHER  THAN  OSCAR 

Weather  Satellite  Pix  Printer. ...............  W3KH 

Toward  A  More  Perfect  Weather 

Picture Cawthon 

Attention,  Weather  Watchers*. ..........  Cawihon 

Be  A  Weather  Genius. WS8DQT 

Autoplnasing  for  WEFAX Cawthon 

SSTV 

What  Are  They  Showing  On  SSTV?. .... ....  K4TWJ 

What  Happened  To  SSTV? .  ^ . .... K4TWJ 

SURPLUS 

Space  Age  Junque  III . . ....  W9CGI 

Surplus  Adventures. W9HDA 

Be  A  Surplus  Survivor, WB4APC 

Another  Surplus  Treasure. , , . , ,  McClellan 

Space  Age  Surplus Endress,  Endress 


TEST  GEAR 

Brew  Up  A  Signai  Generator. Staff 

Clean  Up  Your  Act. Staff 

Build  This  FM  Signal  Generator W9HDA 

Pulses  Galore!, # . , . .  .4 . . .  Plavcan 

Versatrie  Transistor  Tester, ..............  WA5TFK 

The  Quicker.  Slicker  Transistor  Checker Sergo 

How  Many  pF  is  That  Capacitor, 
Real  I  v'^ 

How  Much  Power  Does  It  Draw? . , , . 

The  Amazing  Zener  Sweeper. 

Ecstasy  in  Multimeter  land. ... 

Use  Noise  To  Tune  Your  Station 

Now— A  Digital  Capacity  MelerE 

Make  Antenna  Tuning  A  Joy. 

Home-Canned  Dummy WB2BWJ,  WA2JZR 

Reincarnating  Old  Test  Equipment W3KBM 

Your  'Scope  Can  Be  Improved. N5KR 

Pick  A  Frequency  . . .  Any  Frequency. , W8FX/4 

In  Search  Of  Stability. ...... . ...  Burhans 

Build  A TTY  Tester , . . . , ,, , , 

Interchangeable  Test  Leads, 

Build  An  Audible  Transistor 

Tester.  .,,...„-,.. WB7N2G/DA1DB 


WA0ZCR 
. .  Fowler 
WB4YOD 
.WA4AIH 
.  W600B 
.W3KBM 
. . .  K5QY 


64 

BB 

92 

224 

26 
184 
252 
258 
184 
266 

30 


Sep 
Sep 
Sep 
Sep 
Oct 
Oct 
Oct 
Oct 
Nov 
Nov 
Dec 


140 

Jan 

28 

Mar 

132 

Mar 

176 

Mar 

154 

Jul 

64 

Aug 

120 

Aug 

151 

Aug 

78 

Sep 

201 

Sep 

186 

Oct 

268 

Oct 

186 

Nov 

7?5 

Nov 

250 

Dec 

36 

Mar 

76 

May 

66 

Jul 

82 

Aug 

38 

Nov 

68 

Nov 

124 

Nov 

216 

Nov 

218 

Nov 

254 

Nov 

82    Jan 


.  K7YZZ 
,K3MPJ 


116 

218 

196 

96 


24 
72 


170 

126 

62 

96 

60 


50 
136 
154 
194 
122 

31 

48 

131 
178 

24 
160 

58 
134 
154 

40 

92 
146 

80 
198 
249 


Apr 
Oct 
Nov 
Dec 


Feb 
May 


Jan 

Feb 
Sep 
Nov 
Dec 


Jan 
Jan 
Jan 
Jan 
Feb 
Mar 

Mar 
Mar 

Mar 

Apr 

Apr 

May 

May 

May 

Jul 

Jul 

Jul 

Aug 

Oct 

Oct 


291     Oct 


236 


The  Chip  Switch. 

Build  An  FM  Tweaker 

FM  Calibration  or>  a  Budget. . . . . . 

Build  the  S80  Wonder. .......... 

Build  A  Decent  Dummy 

A  JunK  Box  Load  Srmulator. ...,., 

An  Eicpenmenter's  Delight. 

The  Lunch  Counter .,.*,... 

This  Voltage  Standard  Is  Precise! 
What's  Your  uF?,„„ .,, 


WB2QEL 

,.WA6THG/KH6JSA 

W3HB 

K4tPV 

.  W5J J 

.WA1WLW 

_WA4PIN 

. .  WB6NTR 

..,.K5BTV 


«    m    *   ■*   *   m  '9  ■ 


THEORY 

Think  You  Understand  SSB? , . .  W2FEZ 

Try  The  ID  VIP  Method Hargett 

Op  Amp  Insights, ,,.,,,, . K41PV 

Transistor  Primer. K1UZ 

Ham  Shack  Anthropometrics W3ZVT 

Logical  Logic,  ........,.,,.,„...  h*6WA/WAejMM 

How  To  Use  A  Varactor W6JB 

New  Life  For  Your  Old  Dipper W2CHO/K4EA 

How  Sunspots  Work WA4FDE 

Danger!  Microwave  Radiatron WB6JPt 

Official  FCC  RFI  Report FCC 

DMM  Survival  Course McClellan 

Novice  Guide  To  Phased  Antennas ....  W8HXR 

The  End  of  Rf  Feedback K4TWJ 

A  WWV  Primer W8FX/4 

New  Life  For  Double  Sideband K1I0 

More  CW  Fun  With  Break-In  Keying. WBC&KTH 

DVM  Scrapbook. McClellan 

Gourmet  Guide  To  Capacitors W5J  J 

Reveals  BiasL  .,..,... , , , . W5JJ 

Microstrip .._.__ N6TX 

Low-Pass  Filter  Primer .,_. K20AW 

PLL  Techniques Earnshaw 

The SUMSUE  Method. KiRH 

Head  "Em  Off  ai  the  (High)  Pass WB6GNM 

Educate  Yourself. WBt  AHL 

One  Meier— Many  Jobs. .  _ Fletcher 

Who  Needs  Transistors?. WSJ  J 

Loran-C  as  a  Frequency  Standard, WA4EID 

Ffom  CW  to  Computers , N6RY 


78 
100 
108 
112 
244 
252 

28a 

105 
200 
234 


34 

58 

142 

149 

174 

188 

182 

40 

136 

170 

30 

62 

136 

72 

84 

152 

180 

82 

126 

136 

80 

98 

188 

36 

56 

64 

102 

250 

278 

48 


Nov 
Nov 
Nov 
Nov 
Nov 
Nov 
Nov 
Dec 
Dec 
Dec 


Jan 
Jan 

Jan 

Jan 

Jan 

Jan 

Mar 

Apr 

Apr 

Apr 

May 

May 

Jun 

Aug 

Aug 

Aug 

Aug 

Sep 

Sep 

Sep 

Oct 

Oct 

Oct 

Nov 

Nov 

Nov 

Nov 

Nov 

Nov 

Dec 


Tuned  Feeders  and  Other  Good  Stuff. ......  W0VM 

Big  Max  Attacks. . .  W2DU 

The  'TJim-Flam"  Factor WA2SUT/NNN02VB 


118  Dec 
182  Dec 
216     Dec 


TOUCHTQNE 

Clean  Up  Your  TouchtoneTi^  Act 

Autopatch  Digit  Suppressor.  * . . . . . . 

Painless  TouchtoneTM  Adjustment 

Is  Your  Repeater  Up-To-Date? , . . . 

A  ^  n  e  a  per  wnip, .  ^  .•«*■<...>■.*..  i,*... 
How  To  Thwart  Ma's  Dial  System. ...... 

Quick  Check  For  TT  Pads. 

Total  Control , 

Super  Simple  TT  Generator. . . , 


.  WA6THG 
. . . K4FFW 

. . . .  W3HT 

. . .  W4VGZ 

.  .  W7JSW 

Ring 

. . . K3SPP 
.WB2MPZ 
,WA6AFX 


TRANSCEIVERS 

Tighten  Up  Your  56-102. W2PQG 

TS'700A  Calibrator K9POZ 

Exorcising  Power  Supply  Demons K4rPV 

Re|uvenate  A  Pawnee!. ......,..._  K4GRT,  W4IEV 

TRANSMITTERS 

0\6  Rigs  Can  Live  Again! K4IPV 

You're  Still  Using  Tubes? 

Yeccchl , . . W6HPH/G5AWI 


VHP 


Try  220,  You'll  Like  It! ....  K0OST 

VHF  Notch  Filter WA4WDL,  WB4LJM 

Yes,  You  Can  Build  A  Synlhesi^erL  .,.*....  K2DVQ 
VHF  Trans verlers  and  the  FT*  101 W60JF 

UHF 

UHF  Propagation KL7IEP/1.  W1KIQ 

1220  MHz— Use  It  Or  Lose  It?. ........,.,,,.  K1CLL 

How  To  Succeed  On  1296 W4UCH/2 

The  Challenge  Of  10.5  GHz. ......  W1SNN/WR1 AJE 

Can  Hams  Counter  Police  Radar?. . . WA4WDL 

Novw  Try  1296  MHz, WA4WDL,  WB4LJM 

A  Complete  X-Band  Transmitter W1 SNN 

A  New  Type  of  10  GHz  Receiver. . . , .  Kopeika,  4Z4TJ 
An  X-Band  Transceiver , W1SN N 


44 
124 
146 

66 
150 
164 
115 

60 

78 


53 
128 

52 
104 


Feb 

Feb 
Feb 
Mar 
Mar 
Apr 
Aug 
Oct 
Oct 


Feb 
Feb 
Mar 
Oct 


40 

Mar 

50 

Apr 

154 

Feb 

123 

Jul 

124 

Jul 

168 

Jul 

62 

Feb 

72 

Mar 

32 

Apr 

60 

Apr 

80 

May 

158 

Jun 

38 

Aug 

222 

Sep 

64 

Dec 

An  Improved  HV  Tube  Socket 


easy  modification 


Harry  J.  Milter 
991  42nd  Si. 
Sarasora  FL  33580 


V 


ertical    sweep    ampli- 
fiers may  have  a  high 


pulse  voltage  on  the  plate 
pin  of  the  socket.  This  may 
cause  an  arc  to  the  adja- 
cent cathode  or  filament 
pin. 

Socket  replacement, 
white  proper,  may  take 
considerable  time. 


[  suggest  that  a  slot  be 
cut  with  a  keyhole  saw  be- 
tween the  pins  which  are 
defective.  This  air  gap  be- 
tween the  defective  pins 
now  provides  better  insula- 
tion than  the  original 
socket.  ■ 


SHORT   ACROSS   Pm% 


SAW  SLOT 


BEFORE 


fig.  7. 


AFTER 


287 


type 
7H2n2  tiP% 

7nnz2  sen 

■hUSw 


LITY  and  SERVICE 


» 


SCR 


TRANSlSTOitS.  Ef  C. 

C«»    VCE  IC       PO      Ft        H£Pf 

rD92    4tlV  .lA    ^3U     MHIU     /£4 

n^Oi  *9  1.%     )pO     ISO      S3931 

*    m  1.D  a.o    so 

T097     SO  .9       .S      10 

TO«f    OT  .i      .5    ISO 

tO>5     IW  t  AH^   ^2m     " 

Tflll       4*  .ft       .♦    3TO 

TO-1-  ?50  UO    10,0    SO 

TO106*  TO  -J 
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6  939 

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98 

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9J 
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9999 
10.0000 

10071 
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10311 

10,5 

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11,535 
11.69626 

11.71 
1260902 

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132155 

1 3. 2455 

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13-2845 

13,2945 


2J207063MC 

2^08313 

2^09563 

2-2lOet2 

2210813 

2.212063 

2^14562 

2-214563 

2.215625 

2.217936 

221975 

2.222125 

2,22325 

222675 

222875 

2.23725 

2.2395 

2.24075 

2.241 

2.246 

22475 

2.2925 

25975 

2330 

2:320 

2.32fi2S 

2328a5 

2.3525 

235256 

2  368 

2.374 

2.375 

2.38725 

2.395 

2.396675 

242 

2-4375 

2.44275 

2  4495 

2.45 

24585 

l3  3045iytC 

13.3145 

13-3345 

13,3445 

13.3545 

14-315 

15-016 

15-036 

16.80417 

16.99958 

17  2800 

17.8710 

179065 

17,9165 

17  9265 

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2199965 

22. '99966 

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2547867 

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26  656S7 
26  8965 

28  958 
25  9flS 

27  77776 

28  728 
28.88889 

29  696 

30.0000 

310000 

31  11111 

31 .66667 

32.0000 


246125MC 

2  482 

Z4m 

2B 

2,51375 

2.581 

2.604 

26245 

2618 

2  62625 

2.633125 

2,639 
2,63575 
2  84325 

2.646 

2  647 
2  650750 

2  6545 
2.65825 

2.6G0 

2,6^2 
2.66S75 

2  6695 

2677 
268075 

2681 

2.6645 

2.68625 

2.69575 

Z7 

2.702 

2.704 
2,71075 

2,T^S 

2,716 

2723 

2.730 

2.7315 
2.73225 
2  7326a 

2  733 

32  22222MC 

33.0000 

33  33333 

34  0000 
344 

34  4444 

34  44444 

35.0000 

35  25000 

35  55555 
36,0000 
36.21750 

36.6666 
36.66666 

36  66667 
37.0000 
38.0000 
3877777 
38  77778 
3888889 

:»oooo 

39-160 

40.0000 

4897222 

49.95 
50,14166 
53.45 
54.95 
55.45 
57.45 
58.45 
6945 

60  45 

61  95 
72855 

75 
75  185 

62  75 
83 
64 

85.833330 


2.737MC 

273975 

27*2125 

27425 

2744 

2  7445 

2.74475 

2746675 

2,751 

2.754 

2.75525 

2-762375 

2.7735 

2.776625 

2.78 

2. 81 4 

2.817 

Za225 

2835 

2-854 

2-^65 

2868 

28725 

2.876875 

2J87 

2.889 

2.894 

2.910 

2-920 

2.925450 

2.92545 

2.931 

294375 

2.945 

2.94675 

2.952 

2-966 

2-973 

2.980 

2981 

2-98325 

90.833MC 

93.1346 

93.535 

93  9353 

943 

96 

95-35 

102 

106.850 

123.5 

146-4 

146,54 

147.09 

165.5 

LATE  ADO 

ONS 


200KC 
Z3WC 

24 

3,2 
3.64 
3.7S 
3.60 
5^455 
7SH 
7.15 
728 

7.5 

11 

22 

29 

30 

40 


2-9e7MC 

29989 

3.001 

30235 

3.045 

3.049 

3.053 

30^ 

3.067 

3.074 

3.1125 

3.128 

3.137 

3.13975 

3.1435 

3.144 

3-145 

3.151 

3.1545 

3158 

31585 

31615 

316^ 

3166 

3  16975 

3177 

a  161 

3J825 
3-18475 
3.1885 
3.2035 
3.2072S 
3.2105 
3.2165 
3.2175 
3.23  IS 
2.23275 
3.2365 
323775 
32385 
3  238875 


3.23925MC 

3.24 

3.24025 

3.2405 

3.241 

32425 

3.244 

3  246875 

324925 

3  24975 

3.2515 

3.255 

3.256125 

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3.271125 

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3.4675 

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3.7735 

3.805 

3.803 

3.901 

3.908 

3.9166 

4.O0O0 

4.011 

4.126666 

4.26 

4.3 


4  6895MC 
4  6965 

4  7 
47175 
4  7245 
4.7315 
4  765 
489 
5.0000 

5348400 

5  426636 
S.4366:u> 

5,4990 
5.4675 
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5544 
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SS74 
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5,6265 
56415 
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bon  for  ia02  coo^Hjt?^  iis^s  is  ayHtabk  by  sub- 
scnptkn  fof  S  12.00  p«r  ytar. 

Tiny  Basic  for  ANY  1 802  System 

Cuwtle  ilQM-  fk  flOM  l^ontior  S3S  00, 
Sup*t  £F!  owners.  30*-  Qt*  Uhiazlc^t  llstiflf  or 
ptptr  ta|w  wnii  manuil  SS.SQ. 
Original  EU  Kit  Board  S!4.9S. 

Cassette  Interface  S89.95 

vmply  by  calljno  ttiem  up.  km  prove  m^nti  and 
revtsio  n  1^  »o  easily  done  with  t  he  monil  of  1 1  y o  u 
>ii)ve  the  Super  Eipansion  Board  and  Suptr 

DAonitar  tli&  moniior  js  up  and  running  at  ttie  pu^h 
Of  a  button 

Dther  on  hoerd  options  inctud^  Parallel  Inpul 
«nd  Qutpul  Ports  wilh  lull  handshake  They 
allow  easy  connection  of  an  ASCN  keyboard  1o  the 
Input  part  RS  2 3£  and  20  ma  Current  Loop  tor 
iQleiypfi  or  athier  devicB  are  on  hn^rd  m^l  if  you 
need  more  memory  there  are  two  S- 100  slots  for 
static  RAM  or  video  boards.  A  Godbout  6K  RAM 
board  fs  available  tor  S 1 27.  S5  Para  I  lei  I  /O  Ports 
$1«5,  nS  23?  $4  50,  TTY  2Q  mi  tt¥  %^M, 
S-ld014.5O  ASOpiReaanKtarietwitniibbon 
cable  i^  tvaikbte  M  S12.&0  ^  eisy  conn«ciion 
bitwetti  Uw  Sipir  Ell  and  the  Suffer  Eipmilon 
Inrt. 

The  Power  Suppty  f or  itie Super  Expansion  Soard 
tsiSimptup^ly  with-i-fiv  ;r  l&v  +  12v  -  5v 
iegu£i!ed  voteges  ve  ^5v  S  -i2v  $29  96 
Deluxfi  imitQn  in^u^  t1>e  case  m  S3S  95 


Auto  Clock  Kit  $15.95 

QC  dock  Hth  4-50-  dtsptiy^  Usv^  NirtiOfql 
MA-I0t2  moduh;^  wiU]  alarm  opbon.  Indudes 
Hgtitdimrnef  ctyitallJiiclnstPtbOirTis  FiJ|f 
ngulidd.  comip  Instftcts  Add  $3.95  lor  beau- 
tf^uj  dst  gny  c^e  Best  v^ik  aiywtiere 


RCA  Casmac  V!P  Kft         Z29.Q0 

■.  ^'      ompuier  *rtn  garnes  and  Qraphics 

Not  a  Ctieap  Clock  Kit  iUM 

IntluOes  everv?ninQ  BKcapi  case,  ?-PC  boardE 
6*  50"  U  1)  n. 5 plays,  53 1 4  clock  cftip,  lians^ 
lormer,  all  components  and  W  instrucs.  Green 
and  orange  displays  ai&o  avid  Same  Ml  w/  BD 
dfiplsyi.  Red  only  $21  (Jfi 


Digitil  Tempefstui^  Meter  Kit 
mdoot  ir»d  nutdoor.  Swrttttes  bi^  «na  icfth 
Btauftlul   50'  LED  reaciouts  Mi^tnp  iikee  rt 
avaiiibile.  Needs  i»  additiofiaJ  ptfts  lor  com^ 
pleia.  fnH  fipercton.  ttni  measufe  - 100'  io 
^?0D"F.  tefilhs  of  a  degree,  air  pir  liquid 
Very  accurate  $39. &5 

Seaut^ful  ha^wood  cse  w  l>e:^         $1 1J5 


NiCad  Battery  FUer/Charger  Kit 

Qpen^  BhQned  cells  rbat  wpn't  hold  a  charge 
md  ihen  charges  ihem  up.  all  m  one  ltd  w/toll 

parts  md  instructions  S7.25 


PROM  Eraser 

IJ II r*7 violet.  assGmbled 


$49,95 


60  Hz  Qrvstal  Time  Base  Kit  $4.40 

Cotiveris  digital  clocks  Irom  AC  line  Ir&quuncy  to 
crystal  lime  base  OiJtstafidlnfl  accuracy.  Kit  Jn- 
eludes  PC  bEjard.  MM53B9.  crystal,  r&sistors. 
capaptars  and  trimnrer 


CiDcIc  Calendar  Kit  $23.95 

CT7015  direct  onve  chip  di^pi^ys  date  and 
time  on  S"  LEDS  with  AM-PM  Indicator. 
Ala  r  m.i'  doze  featu  re  I  n  cl  ud  &&  b  u Z2er  Co  rn  p  ici^i 
witti  all  parts,  pow^r  supply  and  instructions. 
less  case 


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CEH<I9 

CCMTfS 
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cn*(i?5 

CD44a7 

^040-10 
CD4{]42 
C0W3 
CS4^4 
004045 
a?4CMIB 
0^4050 

OMQBQ 
BD«fla 

CHon 
nwir? 


Smclair  3^2  Digit  Multimeter 

B^.ACnpe^  tmVind  YltAresokiMn  Ftesn 
mneeip3Drn^T%icaney  Smil.  portable, 
oomfiiatelyassem.  in  tast.  1  yt.  QuAr»niee  Be$t 

Video  Modylalor  Kit  SB. 95 

Converf  your  TV  set  into  i  t^iQti  quality  moniior 
w^ttioirt  affectum  nonnat  usage  Complete  kit 
mih  hj!]  ins^udions. 


Stopwatch  Kit  S26.95 

■    i  so.  ^pt  beltvy  opcfaSed    2-5  vpfti 
3  ?7&fl  MJfe  crystal  acojrKy,  Tunes  to  59 
mirt ,  59  sec  .  99 1/1 00  set  TimtS  «id  ,  sr  ' 
and  Taylor  7205  eiup.  all  components  nu^^^ 
FulT  instructions 


2.5  MHz  Frequency  Courrtar  Kit 

CoinplBtB  liil  less  case  $37.50 

30  MHz  Frequency  Counter  Kit 

ComplEte  kit  less  casa  S47.75 

.Pn^scalgr  kit  ta  35Q  mi S1fi.9S 


1978  tQ  Update  Master  Manuat 

lB7a  IC  Lipdate  Master  Mnncjal  SSO.OO.  Com- 
plate  fC  data  s&lector.  2i7l3  pg.  Maslitr  rafer- 
ence  tjuide.  Over  42.DDO  cross  references 
Free  update  service  through  197S.  Oomastic 
postage  S3. 50.  Fp reign  $6,00 


0  Connectors  RSZ32 

25  Pm  Su^minkittUf^ 

DB25P 

DB25S 

Cover 

RS232CQmpltt&£et 


2.95 
3.§5 
150 


QE9P  150 
0E3S  t  % 
0A15P  2  m 
DABS  3  10 


S-100  Computer  Boarils 

BK  Static  RAM  Kit  $127.00 

16K  Static  RAI\^  KH  265  00 

24K  Static  RAM  Kll  423.00 

33K  Djfnamic  RAM  Ktl  449.00 

64 K  Dynamic  RAM  Kit  %A^  m 

8K/16K  Eprom  Kit  (less  PROMS)  $89,00 

Video  Interlace  Kit  $1 39.00 
Motherboard  S39,      Extender  Board  $8.99 


TERMS:  SS.OOmfn.  order  U.S.  Fundi.  Caiil  residents  add  G%tax. 
BankAmericsrd  and  Matter  Charge  ac^pleft. 
Shipping  charges  will  Ite  added  on  efiarge  tards. 


FREE:  Seiift  (or  your  copy  o1  our  NEW  197B 
QUEST  CATALOG.  Include  ZBm  stamji. 


294 


GALUUM  PHOSPHIDE  L.E.D, 

Provjdes  Higher  fnterisiiy  Tf»an  Regular 
LEDs,  T1-3/4  Dome  i^ed  Dif*ysed> 
AND  Part  ini4R  199    .,22c  100+        20iE 
We  Slock  th«  full  Una  of  AN O  L.e.D.'i 


^^MSSw 


<  I  I  I  I  •  •  I 


DIP  socicrr  specials 

1^*9  50- 

ifi   Pin  Lo*  pFoliie  Scildw  Tad                  20t  \bt 

IS  Pin  StandftfdHetflhTri  Sotdin' Tab      Z5C  JOt 

24  Pm  LOW  PnjJita  Soktef  Tat)  GOLD     €0t  S5c 


CALCULATOR  GIFTS  Experymeiv 
t^f's  delight.  Ea(;h  kevb'Oad  ir^cludes  a 
monoEirtiic  calculator  cliip  and  d  display 
These  are  rejects.  II  might  be  somethina 
simple  to  repair  or  H  c^Quld  be  very  nasty. 
At  thfs  price,  who  cares!  9  voii.  lt.SO  e«. 


5  FUNCTION  L.C.D. 
WATCHES  FROM  NATIONAL 


Seconds 


SEMICONDUCTOR 

•   Hours  •  Month 

'   Minutes  '  Date 

(Gofd)  Leatherette  Band;  f Chrome)  M&ta^ 
Band;    (Goid)   Uelu\    Band;    (Chrorne) 
Leathereite  Band.  SId.OO  EacSi,  Specify 
Model  (Add  SI  00  For  Metal  Sandl 
A  SPECIAL  FACTORY  PURCHASE! 


rNSTRUMENT/CLOCK  CASE 

KIT  Per! eel  foc  youi  opto  proiecia.  Solid 
aiumnnurn  construction  with  real  walnut 
sides.  O  O  safS  '  tfy  5^3/8"  by  2".  S6.95ea. 


50  20B   10 

aWCH  252   10  30  1' 


EDGE  CARD  COMiECraR 

C  nch  Jones  t0^20  Pms  .156  Spacing  PC 

Mount  aSc 


Electronic 


^U9 


A  dtviHiDn 


1'  united  ^incducts 


Corparatiian 


Corp.  Hdcfts.,  2322  i«t  Ave.,  Seattle,  WhIi.  9S1^1    •  (^OfiJ  S«2  5025 


INSTRUMENT/CLOCK  CASE 

KIT  A  reai  j^evuei  for  thnose  smaUer  proj- 
eels  Hiriged  top  door  allows  yoii  to  tiide 
yoyr  conirol  area.  0-0  4'/i "  tiy  4"  by  T ^^ 
$1  50  ea 

EUROPEAN  220V  LINE  CORD 

Building  something  for  export?  Then  fou 
might  nee-d  tht$.  40c  ea.  1 0^53.00. 


TRANSFORMER  Pri  hdvaGScc 

1 1.2  and  5  VCT  @  1  amp.  95t  ea. 


TRANSFORMER    PC   mount     prl 
110  vac  Sec.  12:G  @  1  amp.  11.25  ea. 


CLOCK  DISPLAY  national 

SEMICONDUCTOR  B  digit  multipleKeo 
display  Vt"  char acters.  (Common  anode) 
A  real  buy  at  ju&t  SI .00 


5    FUiiCTiON    L.C.D.    CAR 

CLOCK  Wan  fio  longer.  We  ttrought  the 
price  do^n  on  UC.D.s.  This  is  not  a  kit-  It 
comes  completeiy  assembled,  ready  for 
you  to  easily  install  in  the  dasJh  of  your 
car,  twat,  or  R  V.  5  functions,  ;>rovidiFig 
hours-  minutes-  seconds-  month  and  tiay. 
Power  fS  provided  trom  a  simple  pen  light 
cell  which  will  servjce  fof  about  t  years. 
Ml  grit  lighting  is  through  connection  to 
your  eKistmg  dash  lights.  Time  accuracy 
To  4  seconds  per  month.  You  wonl  fieed  a 
magnifyjng  glass,  to  see  the  time,  either 
This  beauty  boasts  a  big  Vi "  character 
dispi^ay.  Which,  inctdentatly,  has  passed 
the  lemperature  est ( r ernes encour^tered  in 
an  automobile.  Battery  not  included. 
S24,&S 


8PECTRA<STR}P 

bon  cable  *22  sirancj&d 
*Mt...i99;50t.    -100 


Muiltiicolor    t\h- 
20  COfid    75c  a 


mm 


rr 


36      PIN      GOLD-PLATED 

HEADER  Break  olt  Id  desired  lengrh 
Has  dip  spacing    Ust  pnce  Si  36    Your 
price  65«. 

PLASTIC  PARTS  BOX  a  mce  nme 

"  '  ^ed-iop  boK  tor  sioring  all  your  ^nali 
,.^rts  Oct,  %^Jt  by  3^/  by  ?"  7S«  ea. 
1(V$S.OO. 

COMPUTER  POWER  SUPPLY 
TRANSFORMER  pri  itQ.720  var. 

SEC.  12. 1  V  it  9  A,  44  a  V  ,i  2  5  A.  1 2  9V    : 

2  0  A,  12.9  V  «rs  3  2  A   Only  $14.95  *i. 

EDGE  METER  100^ too  ua  1/2 '  by 

11/1S^  Compare  with  other  meters 
costing  SeOO-  ONLY  12-00  •m.  Why  pay 
iTigre? 

CALCULATOR  BUBBLE  DIS- 
PLAY BRAND  NEW  pocket  calculator 
disptays  Flanging  tram  &9  digit  Youf  luch 
SI  25  ea  3^3  00 

KEYBOARD  HOBBY  SAG  Com 

pare,  then  really  save  wiih  our  calculator 
hobby  bag  assoftmenf  Each  one  contains 

3  calculaior  keyboar^j^.  All  this  for  only 
Sl.TS. 


TOGGLE  SWITCH  j  b  t    #jmt 

423 1  Subminintura  4  P.D.T.  S  amp.  ;>t< 
125  VAC  LIST  PRiCe  $5.95  YOUR  PRICE 
$1.11  ea. 


REPEAT  OF  A  SELL-OUT  A  com 

pJete  12  hour  digital  clock.  Some  are  m^tr 
ufacture  line  rejects,  some  are  returns, 
and  some  ara  ju$t  scratched  Features: 
houfS'  minutes-  alarm-  snooze  alarm 
Parts  value  alone  would  equat  $20.00.  you 
pay  only  ie.OO  an. 


%#  Ut  ''■-■  1^ 


DEFECTIVE  CALCULATORS 

Well,  some  are  and  some  are  not.  We  tan '; 
afford  the  time  to  test  them  ^ZSO  ei.  Bal 
re^  es  not  included  2^,00 


#30  KYNAR  Bik  .  Brn,^  Red  .  Or .  Yet,. 
Grn  ,  aiu  .  Vio  .  Gry.,  Wh. 
We  will  do  OUT  b«9t  to  sti'p  the  co^of  you 
specify.  To  ensure  prompt  delivery  of  your 
order  we  will  substitute  colors  should  we 
be  temp,  out.  unless  you  specify  olhef- 
wtse  S2.3fi  per  tiundred  foot  spool: 
Sl4.1Gper  inousand  tpot  fi|K»1; 
MulLiplesol  100' «n|y. 

Call  ua  for  quotes  on  larger  quantifies. 


! 


'' 


V 


l^£  I  I  I  * 
III  I  I  V 


PARTS  BOARDS  a  great  waf  to  buy 
parts  on  a  biidqet  We  guarantee  youf 
money's  worth,  ^NLY  S1.00  aa. 


CAPACITORS 

Capacitance 

Voltage 

style 

Price 

lOOOtil 

25VDC 

PC 

25€ 

220ut 

25VDC 

P-C 

25e 

2000u« 

25  vex; 

AXIAL 

50e 

40^40 

150  VDC 

AXIAL 

45c 

luf 

15VE>G 

AXIAL 

1^ 

-Qie 

icov 

MYLAR 

25e 

001 

100  V 

MICA 

11* 

01 

DISC 

7c 

.02 

DJSC 

6c 

-1 

DISC 

9c 

A  CHRISTMAS  BONUS  Free  with 

ewery  S50.00  purchase  this  manlh    One 
each    National   Semtconducior   LCD 
men's  watch  that  you  see  advert  tsed  on 
this    page.    Hurry,    this   oHer   e?ipires 
December  31. 


DIPPED  TANTALUMS 

Capacitance  Voltage    ToL% 

luf  50  V          20 

2,2uf  50  V          20 

4,7uf  50  V          20 

22uf  20  V          20 

We    stock  the    full    line    of 

MiCONICS  dipped  tantalums. 


Price 

42(t 
62i; 
5H 


SELECTED  VALUES 

Those  ilems  are  chosen  from  our  vasi  in- 
venlory  of  industrial  quality  components: 
Extruded  heat  sink  10  7/8"  by  2  1/4'   by 

5/e" - .$1.49 

500  Ohm  PC  mount  irtmmer  2Cte 

L  me  cord  #1 B  ga  6". .  .  .         .    .  25c 

74LS1  75  Quad  D  Hip-flop 50«^ 

S  P.D.T.  sub  mm  slide  switch.  40c 

s  p  ST  PC  SWITCH aoc 

EKiension  speakers  18"  cabinet  Ipatr^    . 

51^.00 

ACID  BRUSH tOe 

SWITH  #8523  SPACER  5  by  #8  hole &S 

2 cond.  #24  spiral  wrap shid.  cable        tlH 

For  Master  ChargflA/iaa 

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TOLL  FREE  HOT  LINE: 

1-eOD-42  6-0634 

for  arees  Qutsido  Washington 

[inci,  Alaska  &  HawBiQ 


O^E.M.'s  WELCOME 


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Store  Hours   MF  9-6*  SAT  9-5 


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P.O.  BOX  19442E      DALLAS,  TEX.  75219 


(214)823-3240 


SC^i.-iv'i 


->: 


iji-:^^ 


ti^Ei^e*::;-.. 


^:>^. 


■■*-  ■■■  j 


MINI  GHANDFATHES  CLOCK  KIT 


J  %* 


Wi 


ChimK  ths  hoar  ftp:  3  times  fo*  3  O'doc^l 

Unic|ue  "svimnpfig"  LED  fHndu^um 

Tick  tock  KHmcf  mitchcs  pendulum  swing. 

Lirge4  digit  ,5"  LEO  rndout 

AHCMOS  comstfucMofi 

Compl«t£  €LectrooiCt  indudifig  irinifprTner  &  ^xraker,- 

drilted  and  plated  PC  boiifcfi  me«ure  A.S**  x  6.S" 

BEAUTIFUL  SOLID  WALNUT 

Custom  case  for  Above  kit   Ov^r  9^"  tait       1  jr#V5 


POWER  SUPPLY  KIT 
PS-14 


39.95 


^f  ."J 


la-.^,^ 


<j.j 


*  Setter  than  200MV  N»d  and  line  regulation 

*  FolifiiiKlt  Cufreni  Lifniiijig 
'  Short  CifCuil  Protected 

*  Thennal  Shuttkwn 

*  Adjuittble  Curmenf  UmiiJng: 

*  Lnsdian  1%npplt.  ^*     ¥ 

*  15ampi11,5to  14SV 

*  AIT  pam  tuppfied   including  heavy  duty  trans- 
ffirmer. 

*  Quality  plated  fitHrgien  PC  board. 

REVIEWED  IN  7/78  73  MAG. 
15A  CONT. 


,hG 


20A  INT      42.95 


mi 
MP- 


NEVEH  A  SWEETER 
METER! 

Beautiful  Amirlcflii  mid«  panel 
rnelers  are  a  snap  Co  install  Hug«i 
3"^^"  vv^dfidldjs  ar*0AsyiDreftd  Y{>u 
woukf  exped  lo  pay  mor*  for  each 
than  me  geE  tor  the  pakr^  MATCHED 
SET  {M5VDC,  0-30ADC 


OVERVOLTAGE  PROTECTION  KfT 

6.95 

Provides  chnap  insurance  tar  your  eKp^nuvB  ec^ufpmfnt 
Trip  voltage  n  adiyntab^e  from  3  to  ^  volts.  Overvolt^tfe 
instafitiv  fires  a  2SA  SCR  and  shom  the  output  tti  protect 
equipmefit  SHould  be  used  on  units  that  ^tb  fu^.  Di 
recdv  compatible!  with  the  PS  \2  and  PS  T4.  All  $l«ctron- 
ici  supplied.  Drilled  and  plated  PC  board.  (Ord^rOVP  1) 


l'*'j 


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J^£^«l@&:]Sf^l21S^»%ifiCiI%^^^£l 


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MK-05  MINI  MOBILE  CLOCK 

'    -r  vrtatiesT  mil  hen  nn^tsii  ittc^iic  ckK> 

PEATUftES 

-'    cfy*«1  iitf%lMtt 
T,.i.H,j  &  /etwr  rkQPSFSEOvervoltniefirQiacttcin. 

-  Udijrtkr^ed   IS".  6  digit  LED  rualdtiL 

'   Compleif  KHitfi  pnwiuhte  24  hr ,  alarm. 

'    9-t4  VDC#40ioS0rfia,  HQ    Qf> 

•    EASY,  QUICK  ASSEMBLY 

-  All    c&itTparrents    ri&cfuir«d    meluiliHl    [you   upplv  the 

"   Top  qui^1^Iy  drlllod  and  plaiett  HC  bo«rd> 
aoc*<hoard    2.6"  «  2* 

Readout  board:   2  3/8"  »  .75" 


tnaynl  I'l  l^i# 
iFi^ll-unMHl  pinifl 


UNIVERSAL  SOUND  EFFECTS  BOARD 


mm  1DU  EVEB       a>  YOU  could  duplicate  the  so^j^iu  of  a  steam 

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297 


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♦super  SPECIALS:      ^ 


IN34      (IfltrrTiiinilutii  Dioite  10/51 

tNOli    IQOV^IOniA  Diqdi  20/$1 

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1hl4l&1  3flV  1Ngi4  ?5/$li 

SHT  60V  ^jA  arltlQH  H(M:  4/S1 

ZNZ222     NPN  Trpniiitar  5/St 

a^i2B07  P  NP  TriniiitDF  6/S1 

;{M3DS5  PoMMf  XtitoF  IDA  £0.7^ 

IN^aCM  MI>N  Amp/Sw  i.1 1 00  fi/Sl 

2N3a»  m»  Artip/Sw  ^  100  6^1 

CPCCO  rami!  FET  MAmp  t& 


F5A3&01MDlod«Ariey 
MPFtOI  200MHr  RF  Amp 
40873  iyiOSFETHF  Amp 
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LM14S8  Diul  741  rn^lP 
CA30U  S  Tram  Arrvy  DIP 
nCAffi  ^wr  Xitiw  1A  3(m 


RF391  RF  P^HW  Amp  Tramiitav  lO-ZSW  #  3  JOMKl  TO-J 

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LM318CN 
LlVI3ieO 

ilVI33gN 
LM380N^e 

NE567V 
XR567CP 
LM723CN 
LM747CN 


Ki|hS|)Beil  Op  Amp  SOV/^smOtP 
High  Speed  Op  Amp  gOV^s  DIP 
Quad  Cdrnparator  Single  or  Dual  Supply 
7iW  Audio  Power  Amplifier  8 -22V 

Tone  Decoder  (PLL)  D.OTH;  to  500kHz 
Tone  Decoder  (PLL)  OJtHztti  500  kHz 
Preciston  ValtAge  Regulator  2-37 V  DIP 
Dual  741  Compensated  Op  Amp 


SAD1024       Dual  512  Stage  (t024}  Audio  Delav  line 

"Buclcet  Brigade"  AppL  Data  included 
XR2206CP     Function  Generator  with  spplic.  data 
XR2242GP     Long^Range  Precision  Timtf  ^%  to  days 
1  YEAR  TIMER  Kit  2  XR2242'$  ind  Applic.  Note 

LM2901N       Quad  Comparatof  +5V  or  2  to  36VDC 
4  Transistor  Array /Dirlington 
RF/IF  Amplifier  DC  to  120IVIHZ 
Dual  Hiih  Gain  Op  Amp  mDIP 

SPACER  Kit '  4  eB  of  5  assorted  size  spacers 

±15  VDLT  Regulated  Power  Supply  Kit-Easy  assembly, 
&mV  regulation,  IQOmA,  fully  protected. 
Includes  all  components  and  hardware, 
no  PCB  or  ca$e-Add  $L50  for  shippins 


$0.94 
JO 
J9 
JO 

J9 
M 

3/S1 
2/$l 

S13J5 
4,40 
1.50 
3 


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R04558 


SK20 

!,25 
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$13J5 


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1Ngi4 

1N3Q44 
1N3045 
1N3071 

2N2915 
2N3819f\/T 

2N4020 
2N4445 

2N5394E 
2N6912 

2N6Q2a 
2NS44d 

CP&40 


Germanium  Diode  80V  200mA 

Temp  Comp  Reference 

B,2V±5%  1 .005%/  C 

SiNcon  Diode  100V  iQmA 

100V  Zener  IW-Oetter  than  an  0B3 

1T0V  Zener  IW-Better  than  an  DB2/0C3 

200V  IDQmA  Switching  Diode  40ns 

NPN  Dual  Trami^or  3m V  Match  jlOO 
N  Channel  RF  FET  10QMH^Amp 
PNP  Dual  Transistor  5m V  Match  j250 
N  Channel  FET  5;i  Switch 

Ultra  Low  Noise  i  FET  Audio  Amp 
Dual  J  FET  RF  Dif  Amp  to  800MHz 
Programmable  Uniiunction  Transistor 
300  Volt  ly-Channel  J  FET  Amp/Sw 


Broadband  FET  RF  Amp  140dB 

Dyn  Range 
E304  N-Cbannel  RF  FET  3.8dB  NF  @400MHz 

MPSA1Z        NPN  Darlinglon  Transistor  ^20,000 
TISfia  N -Channel  FET  400MHz  RF  Amp 

RESISTOR  Kit-150  pes  %W,  20  most  common  values, 
individually  packaged,  S  to  20  pes  each  . 

PC  BOARD  Mounting  Kit-8  ea  spacer,  screw,  nut 
ind  washer-32  pes  total. 


4/Sl 

$0,60 

25/$  1 

Jfi 
M 

$1.95 

.35 

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3.S0 

$1.25 

2.30 

.45 

2.00 

$4  JO 
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NEARLY  1000  SEMtCONDUCTORS,  KITS,  CAPACITORS,  ETC-SEND  25^  STAMP. 


t^A24 


ELECTRONICS 


BOX  4181  GS 
WOODSIDE,  CA  94062 

Tel.(415)    328  1500 


300 


^   Real-Slate-of-the-Art 

V^  TWO  NEW  AC#DC«BATTERY  PORTABLE   COUNTERS 

OPTO-SOOO.IA  10Hz  to  600  MHz  — FREQUENCY  COUNTER  ACCESSORIES 

•  Precision  TCXO  time  base  0.1  PPM  Stability  17-40=C  PROBES: 

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<10mV  to  50MHz.  25  mV  @  1 50  MHz  <50mV  to  600MHz  #p-ioi       Lo-Pass". .... ... ....... . . .     1 6  95 

•  Auto  Decimal  Point  •  Aluminum  Case  •  Socketed  IC's  #p-i02      Hl-Z,  2X 16.95 

•  Three  oosltion  attenuator:  XI,  X10,  X100  {avoids  false  #aP' 8015  UHF  Counter  Preamp  20  MHz  to 
counting)  600  MHz  1 5-50  DB  Gain 

#OPTO-8000. 1 A     Factory  Assembled    $329.95  (Not  Shown) . .    $49.95/Kit  $39.95 

#OPTO-8000.1  AK    Kit  Form    $27995  ^^  ^g^  Antenna 

#NI-CAD-80  NI-CAD  Battery  Pack $  19.95  Rubber  Duck  RF  Pick-up  450  MHz  ...  $12.50 

OPT0-70CO  10  Hz  to  600  MHz  MINIATURE  COUNTER  #D-146  Same  as  above 

•  XTAL  fTCXO)  Time  Base  ±.08PPM/  C  146.5MHz $12.50 

•  Aluminum  Case  •  Hl-Z  &  50  Ohm  inputs  #RA-BNC  Right-Angle  BNC  Adapter  for 

•  1  Sec.  &  1/10  Sec.  Gate  times  •  Auto  Dec.  R.  above  Antenna 2.95 

•  Built-in  Prescaler  and  Preamps  Standard 
#OPTO-7000      Factory  Assembled  -  1  Year-Guar .  .$139.95 

#OPTO-7000K    Kit  Form 99.95 

#AC-70  AC  Power  Pack 4.95 

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<0.1  PPM.  17-40C 79.95 


OOODDOOO 


ai>T0-i90ii 


ORDER  FACTORY  DIRECT  —  PHONE  OR  MAIL 

TERMS:  Orders  to  US.  and  Carrada.  add  5%  to  maximum  of  S  10.00  per  order 
Ibf  shipping,  handling  and  fnsurance.  To  all  olhec  countries,  add  10%  of  total  of- 
def.  Rorida  res  stents  add  4%  state  tax.  CO.D,  fee:  $i  00,  Personal  checks  must 
baiom  mere  hand  se  is  shipped 


$^Qi 


OPTOELECTRONICS,  INC 

5821  NE 14  Avenue 

Fl.  Lauderdale,  FL  33334 

Phones:  (305)  771-2050     771-2051 

Phone  ofdef  s  accepted 


1^  Rwad^r  Service— S99  pAge  32 J. 


301 


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(   #  *   *   1    p  ■ 


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#••••••#•««« 


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7U«)! 


KTT  FEATURES: 


16K  E-PROM  CARD 

IMAG1HE  HAVING  16K  OF  SOFTWARE  ON  LINE  AT  ALL  TIME! 

S-100  llmsal/Altalrl  Buss  Compatible! 


1.  OoufaJE  sided  PC  board  with  solder 
mask  and  silk  scieen  and  gold  plated 
contact  fingers. 

2.  Selecul3l0  wait  states. 

3.  AH  address  lines  &  data  lines  buf- 
fered! 

4.  All  sockets  included. 

5.  On  card  regulators. 

KST  I  INCLUDES  ALL  PARTS  AND 
SOCKETS  (except  27Q3'5).  Add  $25.  far 
assembled  and  tested. 


S|>t)%7*9o 


SPECIAL  OFFER: 


Our     27QB's     (4&0NS)     are 
when  purDhased  witb  above  lit. 


$8.95 


NEW  PRODUCTS  FOR  1979 

New  Products  are  Scheduled  for  delivery  during  January  1 979.  Some  may  be  available  sooner.  CalL 


•  ••■** 

•  #•••- 

•  ••+•* 

•  ••••' 

•  •••*- 

^  J  •  •• 


Z-80  CPU  KIT 
$129 

For  S-100  Buss.  Features  Jump 

on  Reset  capability.  We  feet  this 

board    has    the    most    correct 

PSYNC  signal  for  trouble  free 

operation.  Complete  kit.  More 

data  on  request,  (for  4MHZ 

ADD  $10) 


16K  STATIC  RAM  KIT 

For  SS-50  (S.W.  TECH.  6800) 
Buss.  Fully  static  uses  2114 
RAM^s,  450  N,S.  At  last,  a  quality 
RAM  board  forthis  popular  Buss 
at  an  affordable  price.  Complete 
kit,  Additional  Data  on  request. 


DUAL  DENSITY  FLOPPY  DISC 
CONTROLLER 

For  S-100  Buss.  Reliability  and 
Quality  assured.  Uses  WD1791 
Controller  Chip.  For  5V^  or  8  inch 
drives.  Full  IBM  and  S-100 
compatible.  Perfect  for  use  with 
CP/M,  Special  P.L.L.  design  for 
maximum  reliability.  Assembled  & 

Tested  -  $219    Additional  Data 

^  on  Request. 


COMPUTER  PARTS 

Z-80     -$19.95    8080A-  $6.95 
Z-80A  -     24.95    821 2    -     2.25 


CPWI  is  a  Tradetnark  of  Digital  Research  of  Califorriid. 


ALARM  CLOCK  CHIP 

N.S  MM5375AA  Six  Digits. 
With  fuil  Data.  New! 

$2.49  each 


MOTOROLA  7805R  VOLTAGE  REGULATOR 

Same  as  standard  7805  except  750  MA  output 
TO^220.  5VDC  output. 

44c  each  or  10  for  $3 .95 


FULL  WAVE  BRIDGE 

4  AMP.  200  PIV. 
BB^         10  FOR  $5.75 


NOT  ASSOCIATHD  WITH  DIGITAL 
RESEARCH  OF  CALIFORNIA.  THE 
SUPPLIERS  OF  CPM  SOFTWARE. 


450  NS!  2708  EPROMS 

Now  full  speed!  Prime  new  units  from  a  major  U.S.  Mfg.  450  N,S. 
Access  time.  1 K.  x  8,  Eqiiiv.  to  4-1  702  A's  in  one  package. 


75  ea. 

PRICE  CUT 


$9 


95 


«295™ 

COMPLETE  KIT 


1 6K  STATIC  RAM  KIT 


ASSEMBLED  &  TESTED 
ADD  $30 


OUR  LATEST  COMPUTEI^  KIT! 


FULLY  S-100  COMPATIBLE! 


FULLY  STATIC,  AT  OVNAMIC  PRICES1 


? 


WHY  THE  2114  RAM  CHIP? 

We  feet  the  21 14  will  be  ihe  nexlindListry 
standard  RAM  chip  (Eike  th$  S102  was). 
Thf&  means  price,  availabiiily.  and 
ualjty  wiM  ell  be  good'  Next,  the  2114  is 
ULLY  STATIC!  We  feel  this  is  tiie  ONLY 
way  lo  go  on  llie  S-100  0uss!  W$'v&  all 
heard  the  HORROR  stones  about  sonnie 
Dynamic  Ram  Boards  having  trouWe 
with  DMA  and  FLOPPY  DISC  DRIVeS, 
Who  needs  these  kinds  of  problems''' 
And  finally,  even  among  ot hex 4K  Stat Jc 
RAM's  the  2114  stands  out*  Not  all  4K 
static  Rams  are  created  equaM  Some  o* 
the  olJief  4K's  have  clocked  chip  enable 
lines  and  variou-s  timing  windows  juit  a* 
crlllciil  as  tSynamic  RAM's  Some  of  ouf 
competitor's  16K  tioards  use  these 
"tricky"'  devrces.  But  not  ua?  The  2i14  is 
the  ONLY  iOQECSi  choice  for  a  trouble- 
free,  straightforward  deigign 


^  w<>IL-ja^.«rti^  Mm^^m^ 


a^^B*"" 

iiiiiiiigiiiiiiin 

.:;  :&«iMttii    .mam 

ijp-.' 

;■■!: 

■    -- 

■ 

'ViU    ir     npTTIUIH    IlilTIUJ^  ...   , 

$33.00 


(450  HS) 


BLANK  PC  BOARD  WITH  DOCUMENTATION 
SUPPORT  IC  S  4  CAPS  -  $19.95 
LOW  PROFILE  SOCKET  SET  -  $12.00 

211 4'S  4K  RAM'S  -  8  FOR  $69.95 
SUPER  SPECIAL:  BUY  32  Kl  I  S  (512  KILOBYTES)  (8-64K  BANKS)  for  ^8,995 


KIT  FEATURES 

1.  Addressable  as  tour  separate  4K 
Slocks. 

2.  ON  BOARD  BANK  SEtECT  Circuitry 
(Cromemco  Standard!)  Allows  up  to 
S12K  on  iine^ 

3.  Uses  2114  (450NSI  4K  Stattc  Rams. 

4.  OM  BOARD  SELECTABLE  WAIT 
STATES 

5.  DoubJe  sided  PC  Board,  with  solder 
mask  and  sHk  screened  iayout.  Gotd 
plated  corttact  fiRgers 

6.  All  address  and  data  lin#s  fully 
buffered 

7.  Kit  includes  AIL  parts  and  sockets. 
S.  PHANTOM  IS  jumpered  to  PIN  67. 

9,  LOW  POWER:  under  2flmpsTYP|CAL 
from  the  +fl  Volt  Buss, 

10.  Blank  PC  Board  can  be  populated  as 
any  multiple  of  4K 


P0 


NATIONAL  SEMICONDUCTOR 

JUMBO  CLOCK  MODULE 


IVlALOOeA 
BRAND  hJEW! 


mm»?: 


ASSEMBLED!  NOT  A  KtTi 

21J1.U  VEHSlONl 

We  h^vca  Itmil^d  number  ol  thie  ?4  HH  flt^l 
l\\T\t' f^i\\'jT\  pi  IfiFS  nMiHJi,:l4'  irr  llijCi; 

#MAiaoeD-SB.S5 


PERFECT  FOn  USE 
WITH  A  TlMe&ASE^ 


FEATUReft. 

*  FCUR  JUMBO  >HNi,:ri  LED  CIS  PLAYS 

*  12  HP  REAL  time:  format 
♦■•S4HR  ALARM  SIGNAL  OUTPUT 

*  SD  Ofl  eO  Hz  OPERATION 

*  LED  BHICHINSSS  COnTRO'. 

*  POWER  FAtlURE  IMQICATOR 
»  S^.£6P  £  SNOOZE  HWERS 

*  OlReCt  L£D  DRiVt  I  LOW  RFIS 
iAC;(FMRS1.g5J              'COWES  WITH  FULL  DATA 

COMPARE  AT  UP  TO  TWICE 
OUR  PRICEl 


W^ANUFACTyRER•S  CL05E0UT1 


Digital  Research  Corporation 


{QP  TEXAS) 


^  P.  O.  BOX  401247    /GARLAND,  TEXAS  75040/(214)  271-2461 


SALE! 

1N4148  DIODES.  SILICON, 

Same  as  1N914.  New, 

factory  prime,  Full  Leads. 

100  FOR  $2 

1000  FOR  $17.50 


New!         REAL  TIME 
Computer  Clock  Chip 

N.S.  MM531  3,  Features 
BOTH  7  segment  and 
BCD    outputs.    28    Pin 

DIP^       $435  With  Data 


16K  DYNAMIC  RAM  CHIP 

16KX1  BU3  IfiPtn  Package.  Sarnfii  as  Mustek  411 5-4.  ?5J0NSa<!<;es.s  itONScyde 
tune.  Oyr  best  price  yet  <oi  ih^g  stale  ot  ihe  an  RAM  32K  and  6h4K  RAM  hoards 
using  this  chip  aKC  ired<ti'ty  ^^djbbr^  Th^se  ^r^  new  Fully  gui^rdnl?^  ijevjces  by  a 
rnaior  mig  VEHV  LIMITED  STOCK! 


$14.95  each 


8  FOR  $89.95 


TERMS:  Add  30<t  postage,  ^e  pay  balance.  Orders  under 
$15  add  75^  handling.  No  C.O.D,  We  accept  Visa,  Master- 
charge,  and  American  Express  cards.  Tex.  Res.  add  5%  Tax. 
Forejgn  orders  (except  Canada)  add  20%  P  &  H.  90  Day 
Money  Back  Guarantee  on  all  items.  J 


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••#**#**#«*#*«»#««#ft#««*#**999«*if 


•  ^*. 


•  •  •  «  # 

*  *  *  •  * 

*       •      «       B       « 


*  ■  •  «  ■  i 

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ROTRON  FANS 

#CT3A52  -  CENTAUR.  4%'' 
SQUARE  220  VAC  60  HZ.  WILL 
WORK  ON  117  VAC  REMOVED 
FROM  NEW  EQUIPMENT. 

LIMITED  STOCK  *_«- 

3  EACH 


*  *  • 


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*•«•«*<•■••• 
»•«•«•«««•« 


•     V     •    a 


•    •    • 

■     «     * 


?  t  J : ?; 


1N4148  DIODE  SALE! 

FULL  LEADS!  BRAND  NEW! 
COMPUTER  MFG.  SURPLUS 


PRECISION  OPTICS 

31.5  POWER  f;2.8 
THREADED  MOUNT 


$195 

I  each 

ORIG.  COST  $16 
These  were  used  in  MICRO- 
FILM equipment.  Perfect  for 
experiments. 


100  FOR  $2 


1000  FOR  $17.50 


PC  BOARD 
EDGE  CONNECTORS 


*-■*-¥- 


r,f~%.^.-—-^',-  -  ■*="  'v- 


7SC  4  FOR  $2.50 

36  Pin.  Gold  Plated  Solder  Tail.  .156  IN.  Spacing, 
Double  Rows  of  18  Pins.  For  standard  thickness 
(.062)  PC  Boards  Major  U.S.  MIg.  PRODUCTION 
QUANTITIES  AVAILABLE. 


SUPER  BRUTE  RECTIFIER 

(limited  stock) 

160  Amps  100  PIV 

Stud  mount  by  Motorola 

$6.95  ea.  or  4/$25. 


FERRITE  BEADS 

8  FOR  M°o 

%  inch  long.  For  RF  cir- 
cuits. Make  inductors 
or  use  forRFI  suppres- 
sion. 


FULL  WAVE 
BRIDGE 

25  amp 
50  PIV 

$1.25 


MALLORY  ELECTROLYTIC 
FILTER  CAPACITOR 

1500  MFD.    16WVDC. 
Radial  Leads.  Factory  Fresh! 

3  FOR  $1         10  FOR 

S2.95 

Perfect  for  Power  Supplies! 
Small  Size:  VM  x  %  Inches. 


1 


12VDC  Relay  by  CDE. 

SPOT.  Coil  is  280  ohm. 
Small  Size.  $1.29 


DC  PANEL 
METER 

TOP  QUALITY. 

SMALL  SIZE. 

500  MA.  F.S. 

$099 


Z-80  PROGRAMMING  MANUAL 

By  MOSTEK.  or  2ILOG.  The  most  detailed 
explanation  ever  on  the  working  of  the  Z-80  CPU 
CHIPS,  At  least  one  full  page  on  each  of  the  158 
Z-80  instructions.  A  MUST  reference  manual  for 
any  user  of  the  Z-80,  300  pages.  Just  off  the 
press.  $12.95 


14 
16 

18 
22 

28 


PINS 
PINS 

PINS 
PINS 
PINS 


IC  SOCKETS 

LOW  PROFILE 
LOW  PROFILE 
LOW  PROFILE 
LOW  PROFILE 
LOW    PROFILE 


6/$1 
5/$1 
4/$1 
3/$1 
3/$1 


OPCOA  LED  READOUT 

SLA-1.  Common  Anode. 
.33  inch  character  size. 
The  original  high  efficien- 
cy LED  display,     75C  ea. 

4  FOR  $2.50 


WESTERN  DIGITAL  UART 

TR1602A.  PIN  FOR  PIN  SUB  FOR 
AY5-1013  mND  TMS6011. 

FOR  SERIAL  I/O 


»2 


99 


EACH 

SURPLUS  SPECIAL 


HEAVY  DUTY  DC  MOTOR 

1.5  to  SVDC  High  Torque.  Heavy 
duty  magnet.  Reversible,  Do  not 
confuse  with  cheap  toy  motors  sold 
by  others.  High  RPM. 

75«P  EA. 

3  FOR  «2 


TIP-30  POWER  TRANSISTOR 

Prime  new/  units.  TO-220  Case. 
PNP  silicon.  VCEO-40  IC-1AMP. 
FT  -  3  MHZ.  30  WATTS. 

3  FOR  «1 

SURPLUS  SPECIAL! 


COLOR  BURST  CRYSTAL 

3.579545  MHZ.   New  Units. 

Used  in  time  bases,  etc. 


.0?^^ 


^' 


990 


EA. 


ELECTROLYTIC  CAP  SPECIAL 

Factory  Fresh!  Small  Size. 
100  MFD    16  WVDC 

6  FOR  M 
30  FOR  *3»5 


FAIRCHILD  RED  LED  LAMPS 

#FLV5057  Medium  Si^e,  Clear  Case.  RED  EMITTING,  These  are  not 
retested  oH-spec  units  as  sold  by  some  of  our  competition.  Theseare 
factory  prime*  first  quality,  new  units. 

10  FOR  sr« 


50  FOR  ^4^^ 

WE  BOUGHT  250,000  PCS."  | 


^D20 


Digital  Research  Corporation 

**  (OF  TEXASl  • 

P.  O.  BOX  40T247  •  GARLAND.  TEXAS  75040  •  (214)  271  2461 


FAIRCHILD  PNP 
"SUPER  TRANSISTOR" 

2N4402.  TO-92  Plastic.  Silicon  PNP 
Driver.  High  Current.  VCEO-40  HFE-50 
to150at150MA.  FT-150MHZ.  Asuper 
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8  FOR  $1 


VOLTAGE  SUPPRESSORS 

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voltage  transients,  spikes,  surges,  etc.  For  use  on  AC  or  DC  in  the 
range  of  12  to  28  Volts  Small  Size;  .5  Inch  Disc  with  radial  leads.  For 
use  across  Iransformer  secondaries,  relays,  etc  More  rugged  and 
reliable  than  silicon  devices.  Rated  at  30  WATT-SEC.  ,25  WATT 
CONT.  Perfect  for  use  on  AC  operated  clocks  and  instruments. 

(THE  GLITCH  SNITCH  J 

SPECIAL  PURCHASE:   3  FOR  $1 


TERMS:  AcJd  3QC  postage,  we  pay  balar^ce  Orders  under  S^5  add  75e 
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•  fl  •  •  * 

«  •  •  «  • 


•  •   *    •   « 

•  •  *  «  * 

•  *  «  •  • 


«  *  •  «  • 

•  ■  •  •  * 


•  *    •   »  « 

•  *    •    9    • 

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*      w      *     * 


*  m 

•  *    *   * 


•  • 


S-100  BUSS  MEMORIES 

THE  BIG  OIVE: 


32K  ECONORAM  y^ 

unkit  only  $599! 

Here  is  dense,  low  power  static  memory. 
Guaranteed  4  MHz  operation.  Configured  as  3  indi- 
vidually addressable  and  protectable  blocks  (one  16K 
and  two  8K].  At  last .  .  .  you  can  fill  your  computer's 
memory  without  overstuffing  your  motherboard,  or 
emptying  your  wallet. 


MORE  PRODUCTS  . . . 


TRS-80  CONVERSION 

fQT  $159 

Expand  the  TRS-80  mainframe  from  4K  to  16K,  or 
use  with  the  memory  expansion  module;  our  detailed 
instructions  describe  both  conversion  processes. 
Includes  all  parts  necessary  for  conversion,  and  is 
backed  up  by  our  standard  1  year  limited  warranty. 
Also  suitable  for  memory  expansion  in  APPLE  com- 
puters, 3  kits/$45Q. 


ECONORAMS  COME  IN  THREE  FORMS  . . . 

Most  of  our  boards  are  available  as  "unkits"  [sockets  and  bypass  caps  pre- 
soldered  in  place  for  easy  assembly);  assembled  and  tested;  or  qualified  under  our 
Certified  Systems  Components  fCSC)  program.  CSC  boards  are  burned  in  for  200 
hours,  serial  numbered,  and  guaranteed  to  run  at  4  MHz  over  the  full  temperature 
range.  We  exchange  CSC  boards  if  any  defect  occura  within  1  year  of  invoice  date. 

AND  ALL  OFFER  THE  FOLLOWING  FEATURES:! 

Fully  static  design,  buffered  lines,  tri-state  outputs,  dip  switch  address  selection 
and  deselection,  write  strobe  selection  switch  for  S-100  boards,  complete  socketing, 
guaranteed  current  and  speed  specs,  a  1  year  limited  warranty,  and  more. 


8K  ECONORAM  IF^ 
$139  unkit,  $159  assm 

Our  least  costly  way  to  add  static  menaory  to  S-100  machines* 
Configured  as  two  mdepeiident  4K  blocks,  with  separate  protc?ct 
for  eacti  blocJc  and  vector  interrupt  provision  if  you  try  to  write 
in  protected  memory.  Handles  DMA,  Less  than  1500  mA  current 
consumption, 


M 


12K  ECONORAM  Vr 

$235  unkit,  $270  assm 

Same  basic  features  as  our  S-100  memories,  but  designed 
specifically  for  the  Heath  H8.  Configured  as  two  blocks  with 
switch  selected  protect.  Also  includes  hardware  and  edge  con- 
nector required  to  mate  mechanically  with  the  H8. 


16K  ECONORAM  IV 


TM 


$279  unkit,  $314  assm,  $414  CSC  I  A  SUPERB  CLOCK:  $16.50! 


Static  memory  configured  as  4  independent  hflocks  (two  6K 
and  two  4K).  Write  protect  for  each  block;  use  with  or  without 
phantom  line;  provision  for  two  qualifiers;  runs  DMS  at  2  or  4 
MHz;  draws  less  than  2500  mA  (1800  mA  typical). 


TM 


24K  ECONORAM  VH 

$445  unkit,  $485  assm,  $605  CSC 

Manual  write  [protection  for  4K  blocks,  use  with  or  without 
phantom  line,  runs  DMA  at  2  or  4  MHz.  Guaranteed  undnr  2000 
mA  current  [typically  1500  mA).  Now  you  can  hav^e  full  static 
storage  at  less  than  the  cost  of  dynamic  equivalents, 


We  think  the  MA1003  dock  module  is  the  best  clock  module 
going  .  ,  .  add  three  time-setting  switches,  a  source  of  power, 
andyouYeupand  running.  Includes  crystal  controlled  timebase 
for  12V  DC  operation  —  ideal  for  car,  van,  truck,  boat,  field 
day,  or  any  other  mobile  application.  Large  [0-3"]  blue-green 
flourescent  readouts  are  visible  under  ambient  light  conditions 
that  would  wash  out  LEDs.  Also,  there  arc  special  options  for 
car  applications  (for  example,  turning  on  headlights  dims  the 
display  slightly  for  night  viewing).  All  in  all,  whether  you  need 
one  for  yourself  or  want  to  present  someone  with  a  neat  gift, 
this   is  an  excellent   choice,   Includes   applications  data, 

3  modiiJes/S46. 


FREE  FLYIS:  40  pages  packed 
wttli  the  latest  in  electTonlc  goodies. 
Send  us  your  name  and  address,  well 
take  care  of  the  rest.  For  first  class 
delivery  enclose  41^ 


BILL  GODBOUT  ELECTRONICS 
BOX  2355,  OAKLAND  AIRPORT.  CA  946U 


TERMS:  Add  Si  hendlitig  to  orders  Lindar  $15, 
Allow  up  5%  shipping  [excflsa  refundedK  We 
prefer  street  address  for  LFPS  delivery. 
VTSA*  /Master charge*  cali  our  24  hr.  ordfir 
desk  fli  (415J  Sfia-Oesa  CODs  OK  with  street 
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01 


ELECTRONICS 


Kits 


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*  U9«  LM  309K 

«  Heat  smk  pTovrded 

«  PC  tHWrd  conslciiciJon 

*  Provides  a  sdid  1  amp  (^^ 
5V 

*  iTicludes    com;iontnts. 
hardware  and  insrryciians 

JE200      $14.95 


Function  Generator  Kit 


m  PfovidflS  3  basic  mave- 
larms,  sine,  rnangle  A 
square  ivave 

•  Frfquen^  nn^t  Trofli !  Hz 

*  Output  imphtu^e  from 

» ll$«s  a  ISV  supply  EH^  a  - 

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C9fnpdrt«nts  and  ifmntc- 

trons. 

JE2206d        $19.95 


NT 


Digital  Stopwatch  Kit 


_Wwl« 

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f 

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PC.  Boaid 

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mo  res*i 

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stngfe  event,  spin  icummjl^tive^ 
and  Eaytor  isequeflM  timiniy) 

*  Uses  3  penfite  t^ftefiis 

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JE900     $39.95 


MICROPROCESSOR  COMPONENTS 


s.-n 
nzsa 


cpy 

Pfionff  Inle^ujal  Coranal 
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t  9% 
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II.  Miflf^Jril  I  Mill 
■  ,bpf  11111 


EflfLiitifii   lub  ifL^iriikytit  hiM»i|iMi»r  (f¥ 


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« Sequenlial  flashing  colon 

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JE730 


$14,95 


6-Digit 
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»  Bnghl  300  ht  conirtion  cathode  display 
.  Uses  MWS314  dock  aip 

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w  Hours  easily  viewable  to  20  r«et 

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•  Size  6-3i4-jt  3-1/8' «  1-3/4- 

JE701  $19.95 


Jumbo 


Clock 
Kit 


•  Four .  630"  H  and  two  3Q(rht  common  laodei 
.  Uses  MM^14  dodc  dup 

.  Switches  fof  hours.  nMfuilfs  and  hold  tlMCbons 
.  Hdut^  easily  ^iwiiBte  to  30  feet 
.  SimifigM  wainur  ci$e 
.  1)5  VAC  opemion 
.  i3ar?4tioufOpvallon 

*  Includes  all  compomsnts.  case  ami  wall  transformer 
Size:  6-3/4- 31  3-1 /r  I  l-3;4' 

JE747  $29-95 


XMAS  SPECIAL  -  Get 
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your  PDM-35 
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fttoder  ZBDO 
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CCiTirir  •   I    :r   ■ 


a^'OlQit  Porta  bla  DMM 

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*  \rm   Wl  {]  •  IWiti  n^yHSn 

*  f'J  qieg  incul  irnpenilenLi 

AEVMipe  U-IDtKlV 

FfbI   AsiCHinsE   ^"ICIO  HZ 

^?iSistoiK*  Q-lDmetfaPirti 
Slit  ^  J   .  I  *  ti 

AC  Adapter  IC'2B      $9.00 

Retl^irseajilt 


MtniT  I  tiiiHOV 

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Ilii4iiimi  tli  niimiii.|i 

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i^lSMffk  H^HtMin*.  I  }^  T  <  fliuli. 

AtM>  p»MMlH  1  tHMIMtl'laik  MAiffl 

tHrMMtaMr  (( in  I  I  ni  I  w  i  a 
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i^ulirmi'lM^i 

IMIaiHi  M.  itJi|iiii  liirlir  ^ 

Aillli'l,  I'VLTi   1^  IvirflfihlrJ 


100  MHz 
8-Diglt 

Counter 

lii:iti«i.  1  iQ  1)1  "S'ityi  ttm 
c>i4'tl*i  '^V  wirti  luid 
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•W""  «1 34.95 


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ACCESSOI^ieS  FOR  MAX  100: 
MDbllt  OHtpr  Dlwunir 

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.tf  1  lii  ¥  U  H*M  in  —  CM  MM 


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Mini -Max  6  DIqU  SOUm  Frequency  counter 


rtne«  (It  1W  Hi  a  SO  UHr 
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MINI-MAX      $89.95 


—  Ori^tat 


Pati  No. 

VM-CS 


lut^Aca 


Aj^cessortes  For  Mini -Mai 
Description 

Attt 


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Ib.m  U.yj\im\im  Order  -  U.l  Fundi  Ofity 
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TRS-8Q  16K  Cofiversion  Kit 

Expand  your  4K  TRS-SQ  System  lo  16K.  Kil 
OKTies  complete  wtt)i; 
*  8  eacn  lfPD416  f16K  Dynamic  Ranis) 
'  Documentation  for  conversion 

TRS-16K  $115.00 

Special  Otfef  -  Order  Doth  your  TRS-16K  ami  me 
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OUAtlTYC'lSCASSm^S 

•  piastk:  case  iiiauDei 

12  CASSETTt  CAPACTTY 
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SUP  'R'  MOD  II 

UHF  Channel  3a  TV  Inlertace  Unit  Kit 

*Wide  Band  B/W  or  Cdar  Sys(frm 

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ikr,  SQL-2C1,  IRS -BO.  Chdltangirr. 
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^  MOO  II  ts  pretune^  to  Channef  33 

*  Includes  coaxial  caDie  and  antenna 
transfcnriBT 


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Custom  Cables  &  Jumpers 


Part  No, 

D;B25P-^P 
□S25P-4^S 
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0J1M 
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DB  25  Series  Cables 


CabJe  Lengtii 

4  F] 
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An 
Dip  Jumpers 


Connectors  Prifja 

2-DP?5P  STS  9S  ca 

1-DPZ5P.I1-35S  STSSSea 

?-DF35P  S17  9&  ei. 


1  tt. 
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1  ft 
1  tt 
t  fi 
1  tt 


1  14  Piti 
1-16  Pin 
l-^-lPin 
2-14  Bn 

2-24  Pm 


SI  59  «a 
1  TOfli 
3  79  m 

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OBSI^TBI  cable  Cover  for  DB25  P  Of  S      175 


63-Key  Unencoded  Keyboard 


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1  *'  tasg ails fWBtip^iafen  msTDQi  $2§  QS^eacfi 


Hexadecimal 

UnencDded 

Keypad 

19-kev  pad  indudes  1-10  iteys, 
ABCOEF  and  2  ootion^  bi^s  ^0  i 


$^  H&adet  Service^see  p^gm  323. 


305 


DIODES/ZENERS 

SOCKETS/BRIDGES 

TRANSISTORS,  LEDS,  etc. 

1N914 

lOOy^ 

lOmA          .06 

8-pin       pcb        .20       ww          .35 

2N2222 

NPN   (2N2222  Plastic. 10) 

,15 

TN4005 
1 N4007 

600v 
lOOOv 

1 A             .08 

lA             .15 

14-pin       pcb        .20       ww          .40      ' 
16-pin       pcb        .20       ww          .40 

2N2907 
2N3906 
2N3904 

PIMP 

PNP   (Plastic  -  Unmarked) 

NPN  {Plaitic- Unmarked* 

,15 
,10 
JO 

TN4148 

75v 

1C 

)mA           .05 

18-pin       pcb        .25       ww          J5 

2N3054 

WPN 

.35 

1N4733 

5.1v 

1   W 

Zener      .25 

22-pin       pcb       .35       ww         .95 

2N3055 

NPIM      15A    60v 

.50 

1N753A 
1N758A 

6,2v 
lOv 

500  mW  Zener    .25 

,25 

24-pin       pcb        .35       ww          .95 

28-pin       pcb       .45       ww        T,26 

T1P125 
LED  Gfesn, 
D.L.747 

PNP      Oartington 
Red,  Clear,  Yellow 
7  seg  5/8"  High  com-antjde 

.95 

J5 

1.95 

IN 759 A 

I2u 

.25 

40-pin       pcb        .50        ww        1.25 

MAN72 

7  seg  com-snode  ( Red) 

1.25 

TN5243 
IN  5244 B 

13v 
14v 

^'              .25 

"                 25 

Mo  lex  pms    .01     To-3  Sockets     ,25 

MAN3610 
MAN82A 

7  seg  com-af>ode  (Orange J 
7  seg  com-anode  ( Yellow  J 

1.25 
1.25 

1N5245B 

15v 

.25 

2  Amp  Bridge         100-prv              .95 
25  Amp  Bridge      200'prv            1 .95 

MAN74A 
FN  0359 

7  segcom-calhode  (RedJ 
7  seg  corn-cathode  (Red) 

1.50 
1.25 

CMOS 

-    T    T     L    ^ 

4000 

.15 

7400 

.10 

7473              .25 

74176            .85 

74H72 

,35     ; 

74S133 

.40 

4001 

.15 

7401 

.15 

7474               ,30 

74180            ,55 

74H101 

,75 

74S140 

.55 

4002 

.20 

7402 

.15 

7475               ,35 

74181           2,25 

74H103 

,55 

74S1 51 

.30 

4004 

3.95 

7403 

J5 

7476               .40 

74182            JB 

74H106 

,95 

74S1 53 

.35 

4006 

.95 

7404 

.10 

7480               .55 

74190           1.25 

74S157 

,75 

4007 

.20 

7405 

,25 

7481                ,75 

74191             .95 

74  LOO 

.25 

74S158 

.30 

4008 

.75 

7406 

.25 

7483               .75 

74192            .75 

74L02 

.20 

74S194 

1.05 

4009 

.35 

7407 

,55 

7485              .55 

74193            .85 

74L03 

.25 

74S25?  (8123) 

1.05 

4010 

.35 

7408 

.15 

7486              .25 

74194            .95 

74L04 

.30 

4011 

.20 

7409 

,15 

7489             1 .05 

74195            .95 

74L10 

,20 

74LS00 

.20 

4012 

.20 

7410 

J5 

7490               .45 

74196            .95 

74L20 

.35 

74LS01 

.20 

4013 

.40 

7411 

.25 

7491               .70 

74197            .96 

74L30 

.45 

74LS02 

.20 

4014 

.75 

7412 

.25 

7492               .45 

74 1 98          1 .45 

74L47 

1.95 

74  LS04 

.20 

4015 

.75 

7413 

.25 

7493               .35 

74221           1.00 

74L51 

.45 

74LS05 

.25 

4016 

.35 

7414 

.75 

7494               .75 

74367            .75 

74L55 

.65 

74  LS08 

.25 

4017 

.75 

7416 

.25 

7495               .60 

74L72 

.45 

74LS09 

,25 

4018 

.75 

7417 

,40 

7496               .80 

751 08  A         ,35 

74L73 

.40 

74  LSI  0 

.25 

4019 

.35 

'       7420 

.15 

74100           K15 

75491             .50 

74L74 

.45 

74LSt1 

.25 

4020 

.85 

7426 

,25 

74107            .25 

75492             .50 

74L75 

.55 

74LS20 

.20 

4021 

.75 

7427 

.26 

74121             .35 

74L93 

.55 

74LS21 

.25 

4022 

.75 

7430 

.15 

74122            .55 

74  LI  23 

.85 

74LS22 

.25 

4023 

.20     1 

7432 

,20 

74123             -35 

74H0O            .15 

74LS32 

.25 

4024 

.75 

7437 

,20 

74125             .45 

74H01             .20 

74S00 

.35 

74LS37 

.25 

4025 

.20 

7438 

.20 

74126             .35 

74H04            .20 

74S02 

.35 

74LS3S 

.35 

4026 

1.95 

7440 

.20 

74132            -75 

74H05            .20 

74S03 

.25 

74LS40 

.30 

4027 

.35 

7441 

1J5 

74141             .90 

74H08            .35 

74S04 

,25 

74LS42 

.65 

4028 

.75 

7442 

.45 

74150             .85 

74H10           .35 

74S05 

.35 

74LS51 

.35 

4030 

.35 

7443 

.45 

74151             .65 

74H11            .25 

74S08 

.35 

74LS74 

.35 

4033 

1.50 

7444 

.45 

74153            .75 

74H15            -45 

74S10 

.35 

74LS86 

,35 

4034 

2.45 

7445 

.65 

74154             .95 

74H20            ,25 

74S1 1 

.35      1 

74LS90 

.55 

4035 

.75 

7446 

JO 

74156            .70 

74H21             .25 

74S20 

^5 

74LS93 

.55 

4040 

.75 

7447 

.70 

74157             .65 

74H22            .40 

74S40 

.26 

74LS107 

.40 

4041 

.69 

7448 

.50 

74161             .55 

74H30            .20 

74S50 

.20 

74  LSI  23 

1.00 

4042 

.65 

7450 

.25 

74163            .85 

74H40            .25 

74S51 

,25 

74  LSI  51 

.75 

4043 

.50 

7451 

.25 

74164            .60 

74H60            ,25 

74S64 

-15 

74  LSI  53 

.75 

4044 

.65 

7453 

.20 

74165          1.10 

74H51            .25 

74S74 

.35      ' 

74  LSI  57 

.75 

4046 

1.25 

7454 

.25 

74166           1.25 

74H52            .15 

74SI12 

.60 

74  LSI  64 

1.00 

4049 

.45 

7460 

,40 

74175             -80 

74H53J          .25 

74S114 

.65 

74LS193 

.95 

4050 

.45 

7470 

.46       1 

74H55           ,20 

74LS367 

.75 

4066 
4069/74  C04 

.55 

.25 

7472 

.40 

74LS368 

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4071 

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8038                  3.95 

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LM201                  .75 

LM320T12        1,65 

LM340K18 

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LM725N 

2,50 

MCI  4409           14,50      | 

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LM320T15        1.65 

LM340K24 

1.25 

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MC  14419 

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LM308  (Mmi)       .95 

LM324N            1.25 

78L05 

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4511 

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LM339                 .75 

78L12 

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LM311DfMlnl)     .75 

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9309       .35 

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9322       ,65 

9602 

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("BBUN  GmE  IT  THIN  PHfCES 
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hta.  3139  and 
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:    SANYO 
*     AUDIO 
:AMPLIFI£R 
MODULES 


•*t«»«t*«t< 
tajy  tabujtd  *  tpmpJ'CU'  hu^)« 
Ainplifiar  for  hifi,  ip[i*,  AM 
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CJJ.  No.   1219  FUEICALIR  RJT 
Cat.    Ma,     11221    PREBcai  r» 

WmtO  IMPS       "-wwcALii 


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STK  4$4 
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includJngtlit  btit  birfAlnB^t 

•  ICMtCOirDl^CTDBS  *  ft«l.r  Epafffl 
o  C*Maa|*f  C«mp»fi*ata        •  Flfa«r  Optica t 

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p^  Peatler  S€rvic«—te*  page  323. 


309 


7294  N.W.  54  STREET 
MIAMI,  FLORIDA  33166 


URPLUS 
LECTRONICS 


PHONE:  (305)887-8228 
TWX:       810-848-6085 

WHOLESALE-  RETAIL 


PL  259's 

QUALITY  AMERICAN  MADE 
10/$5.00  100/$35.00 

50/$40.00  100G/$300.00 


E.  F.  Johnson  Desk  Top  Microphone 

Ceramic  Element/High  Imp 

$20.00  ea 

While  They  Last 


IC  SOCKETS 

Cambion 

Gold  Plated  Wire  Wrap 

14  pin       .35  ea  l0/$3.00 


16  pin       .38  ea 


10/$3.30 


SURPRISE  PACKAGE 

Resistors^  Caps,  Semis,  Pots, 
Relays,  etc.  We  guarantee  it  to  be 
$25,00  worth  of  matefiai.  Every 
package  is  different. 

$5,00 


TEXAS  INSTRUMENT  KEYBOARD 


$1.95  ea, 
5  for 
$8.00 
10  for 
$13,95 


Has  3  slide 
switches— 28 
different  keys 
keypads  re- 
movable by 
removing  4 
screws. 


White  Porcelain 
Egg  Insulator 

IV2"  X  1'^  50$  ea 
3  for  $1.25 


MINI  TOGGLE  SW 
C&H 

SPOT 

SroOea  B^SS.OO 


Neon  Panel  Light 

110  Vac  Amber,  w/  built  in  resistor 

&  wire  leads— 3  for  $1.50 


WIRE  WOUND 
RESISTORS 

.1  Ohm— 5W 
.10  Ohm— 10  W 
15(f  each 


12  Udc  RELAY 
SPST  35  Amp  Contacts 

Open  Frame 

Rugged,  great  for  mobile  usie 

$4,50  ea  5/$20.00 


MODEN  CABLE 

50'  cable  contains 
13    #   22   ga.    wire    DB-25p   with 
DB-51 226-1  cover  on  one  end 
$6.50  ea  10/$5D.OO 


New  Dry  NIcket-Cadmlum  Battery 

2Va''  )c2¥4"x  8¥4" 

General  Electric 

12.0  Volts  dc  @  4.0  Amp  hrs, 

$19.95  while  they  tast. 


PANEL  METERS 

ZVr  X  2V4"  also  2V4"  X  3" 
10-0-10  dc  Amps    .  $4.00  ea 

0-20  dc  Volts 
25-0'25  dc  Volts     >  2  for 

0-25  dc  Volts     \  $7.00 

0-50  ac  Volts    ^ 

-Shunt  Required- 


CB  SPECIAL 

Complete  brand  new  printed  circuit  board  assembly  with 
all  parts.  Used  in  all  Hygain  40  channel  CB  Transceivers. 
Fits  many  other  manufactures  units  also. 

Board  dimensions  6"  xSVa" 

1-9— 7.50  ea 

10-50— 6,60  ea 

50-100— 6.00  ea 

100-up— 5.50ea 


MUFFIN  FANS 

3  Blades,  110  Vac,  4V4"  sq. 
Removed  from  equipment- 
Excellent  condition— $4.95 


^*New"  Muffin  Fans 

3  Blades-110  Vac,  4W  sq. 
$9.95 


CMOS 

RCA  CD  4012  AE 

Dual  4  in  Nand  Gate 

6/$1.00  100/$1O.O0 

50/$6.00  1000/$80.00 


12  Vdc  RELAY 

SPST  Open  Frame 

5  Amp  Contacts 

Mfg-Magnecraft 

$1.50ea  4/$5.00 


POLYFOAM  COAX— 50  OHM 

Equal  to  RG174 

$4.95/100* 

Low  Loss 

Polyfoam 

Coax  Cable 


TRIMMER  CAPS 

Small  enough  to  fit 

in  your  watch— 

3.5  to  20  pF 

5  to  30  pF 

7  to  40  pF 

$75  ea.,  2  for  $1.25 

5  for  $3.00 


DCellNicad 

mfg.  by  G,  E.  2.50  ea 

1,2  volts  3.5  amp  hrs. 

cat  No.  41B004  AD08G5 


Computer  Grades 

23,200  uf  @ 50  Vdc  3.00  ea 
3^^dlamx4y2"  highG,  E, 


Coax  Connectors 

UG-273/U  BNC-F/UHF-M  2.50 

UG  255/U  BNC-M/UHF-F  3.00 

UG'146A/U  N'M/UHF-F4.50 

UG-83B/U  N-F/UHF-M  4.50 

UG-175  RG-5a  Adapt.  .20 

Uai76RG-59  Adapt.  .20 


New  Boxer  Fans 

5  Blades  110V  ac 
43/4-_$ii^95 


JOY  STICK 

For  TV  games  and  hi  fi 
with  four,  100K  pots 

23/4"  X  2W  X  1" 
with  V  handle— $3,95 


GOLD  PLATED  CARD  EDGE  CONNECTORS 


Double  Row/Wire  Wrap  ,100 
25  pins  $3.49  ea  10/$30,00 

30  pins  $3.96  ea  10/$32.00 

50  pins  $5.43  ea  10/$45.00 


PoubiB  Row/Solder  Eyelet  .156 

Spins  $1,10  ea  10/$9.00 

15  pins  $1,55ea  10/$12.50 

22  pins  $2.08  ea  10/$17.00 

43  pins  $3.66  ea  10/$30.00 


22  pins/ Double  Row/Dipped  Solder 
.156  $2.08  ea  10/$17.00 


22  pins/Double  Row/Wire  Wrap 
,156  $2.44  ea  10/$19.00 


Aff  ma  ten  A  { gu^rsnteed  •  if  for  any  reason  you  are  not  satisfied,  our  products  may  tie  rettjrnei^  wrthfn  W  days  for  s  tuii  refartd  {less  shipping}.  Pfease  add  $ 
TER  MS-  for  shipping  snd  handiing  on  stf  orders.  Additional  5%  charge  for  shipping  any  item  over  5  fi?S-  COD's  accepted  for  orders  totaffog  $50.00  or  more.  AH  order 
shipped  UPS  unless  otfierwise  specified.  Florida  residenfs  pfease  add  4%  sales  tax.  Minimurr}  order  $15^00. 

EQUIPMENT  /  COMPONENTS  /  W/RE&  CABLE  /  ACCESSOHJES 


310 


GET  YOUR 


ue'*' 


Published  December  Ist,  1978 


Specialize  in  DX?  Then  you're 
looking  for  the  Foreign  Callbook 
with  over  280,000  calls,  names  and 
addresses  of  radio  amateurs  out- 
side the  USA  plus  many  valuable, 
additional  features  of  interest  to 
the  DXV. 

FOREIGN   GALLfiOOK 

$14.95 

PLUS  SHIPPING 


RADIO  AMATEUR 


CALLBOOKS 


The  U.S*  Call  book  has  over 
350.000  W  &  K  listings.  It  lists 
calls,  license  classes,  names 
and  addresses  plus  the  many 
valuable  back-up  charts  and 
references  you  come  to  expect 
from  the  Cailbook. 

UNITED   STATES  CALL  BOOK 


T^^- 


ym-.Kfr- 


Respected  worldwide  bs 
the  only  complete  authority 
for  radio  amateur 
QSL  and  QTH  information. 


$15.95 

PLU9  SHIPPING 


See  your  favorite  electronics  dealer 
for  the  latest  issue  or  order  direct 
from  the  publisher  using  handy  order 
form. 


Payment  in  U.S.  funds  must 
be  sent  directly  to  publisher 
not  through  a  bank. 


Radio 
Amateur 

callb 


i^m 


k 


ORDER   FORM 


C 


linn 


□  " 


S     CALLBOOK 


rn  FOREIGN  CALLBOOK 


Pi-ic«     EkK 


^T 


$15.35 


S14.9S 


S^vtp'pint 


st.rs 


$1.75 


Tutjil   Pirir 


SI  7.70 


$1S.70 


\moh  residents  only  add  5%  soles  tax 


,  INC. 


niame. 


Address. 


TOTAL 


925  SHERWOOD  DRFVE 
LAKE  BLUFF,  JLLJHOJS  60044 


City. 


State, 


Zip, 


Ctiarge  my:  D  Visa  Card    D  Master  Charge 

Card  No 

Dcpt.  B  Signature 


Expiration  Date 


iL 


1*^  Reader  Senftce — see  pege  323. 


311 


Provides  full  frequency  coverage.  220-225  MHz,  lor  your  Midland  509. 
Cobra  200t  or  Clegg  76  transceiver  Provides  simpler,  repealef.  and 
reverse  modes  on  all  frequencies.  New  irripfoved  mterface  circuit  pro- 
vides greater  flexibility  and  RF  immunily.  FULLY  ASSEMBLED  & 
CALIBRATED 


Cushcraft 
Beam  I 


still  only  $129»* 


ATTENTtON  22S  OWNERS! 


Buy  your  Synthacoder  509  during  -c>^^^^^ 
our  SOS  sale  and  receive  a      ^^"^^^ 

FR€E  Cushcraft  BEAM  AMTENNA        / 


Regular  87,95 
SOS         69.95 


"The  Original"  Synthacoder  22.  used  by  many  hundreds  of  ICOM  ow- 
ners throughout  the  country  tor  years!  The  ultimate  in  frequency  con- 
trol for  the  22S  Full  thumbwheel  control  in  15  KHz  steps.  You  won't 
want  to  miss  oul  on  th+s  SOS  Super  Saverl 


SYNTHACODERS  ARE  AVAILABLE 
THRU  YOUR  LOCAL  DEALER 


We  Are  About  To  Announce  Some  New 
"SUPER  PRODUCTS" 

WATCH  FOR  OUR  ADS 


E12   Engineering  SpecialtieH 


* 
* 


P,0  Box  2233 
1247  Commerctat  Avenue 
OKnard.  Cahfom^a  93030 

(805}  4^6-0617 


* 
« 


.^-i?^ 


Name 


Address 
City 


Yes    I    want    to    take   advantage   of    your   SOS   Super    Saver! 

a     Please  BUSH  my  Synthacoder  &09  and  FREE  BEAM  ANTENNA 
Enclosed  is  my  $129,95  plus  S3  00  postage  and  handling. 

D     Please  RUSH  my  Synthacoder  22.  Enclosed  is  my  $69.95  ptus 
$2  00  postage  and  handling. 

California  residents  add  6%  sales  tax. 


OCheckQ  Money  OrderO Charge  Card 


Please  charge  my  D  Master  Charge   D  BankAmericard/VISA 
Credit  Card  # EKpiration  dale 


Signature 


Call 


■ 

i 


* 


Slate. 


Zip 


73-12    • 


312 


ALDELCO  ELECTRONIC  CENTER 


OVERVOLT 12 

Crow  Bar  circuit  protects 
Transceivers  &  Tape  Decks  from 
runaway  power  supply  voltage  that 
can  zap  expensive  components.  OV 
12  causes  fuse  in  Power  Supply  to 
blow  if  voltage  exceeds  preset  level 
(approx.  16  to  18  volts),  Rated  at  25 
Amperes.  $  7.95 

Model  0V5-  Protects  5  Volt  circuits. 
Triggers  at  7.5  Vo?ts  $8.95 

Other  units  available  at  3.3  to  100  Trig- 
ger Voltages  $10.95  ea 


A  EC  1074  50W 
#30  MHz  $21.15 
A  EC  1076  75W 
m  50  MHz  $24.00 
botn  cases  500  4LFL 


THE  LUNCH 
COUNTER 


1 


LUNCH  COUNT  FA    "^ 


Build  a  600  MHz  6  Digit  Frequency 
Counter.  We  supply  3  PC  Boards,  Silk 
Screened  Front  Panel  and  complete 
Instructions  OnJy  $12.50 

Chips  used  in  Counter 

11C90PrescaJer  $14,50 

74C925  9.95 

F9368  {2  used)  ea  3.95 


NEW! 

THE  FUTURE  NOW! 

FM2015R 


KDK 


do**  fDiJi  uibi  c.iiw*t  Th*  Niw 


A.IV  SoHd  State  CMOS  KL  <fi«itJi4  ivntlifliiisd  -  No  Cryftatt  l[»  Suvl  &KHt  tiApt  ■ 
1  44  -  14:^  MHt-LED  d4$ll«l  f^^oul  P^yS  MARS-CAP.' 

■  G  WHi  BiTvd  Cby/vwrn^  -1000Chann«l»  rin4l«fta of  tht  uiuil  2MHi  to  4KKz-400 
t«  8D0  Ctmnn^^il^  ■  4  CHA^ffyEL  RAM  IC  MCMOftr  WJtH  SCAIVNfNG  • 
MULTII^L£  FBeaueNCV  OFFSETS  •  ELECTRONIC  AUTO  TUNING  TRANSMET 
AND  RECEIVE  •  FNTERNAL  MULTIPLTHPOSE  TOJ^E  OSCILLATOR  •  RiT  • 
DJSCftlMlh^ATOR  METER:-  iSWatti  Output-  Ufwqualad  R«caib«t  $Brti;|kw4iy«nd 
SBlectSwty  15     POLE     FILTER.     MdNdLITHIC     CRYSTAL     FJLTEfl     AND 

AUTOMATIC  TUNED  RECEIVER  FROr^T  END.  CCMPAREI+SuperbEnBinHnng 
and  Superror  CommefclAl  Awionic»  Qr«d«  QuilitV  and  CtirtilructiiDn  Ss^ond  to 
None  at  ANY  PRICE. 


PRICE 


Cc 


Har<J  to  find  replacement  for 
VHF  MotJile  t  Marine  use. 
Successfully  used  in  Stan- 
dard and  other  VHF  Rigs, 
Rated  t2  Watts  at  200  MHz 
12,5  Volts  with  5.3  OB  Gain. 
Heat  Sink  stud  (3/32)Jsolated 
fromieads.  Only  $12.30 


110  TTF 


$439.95 


**»» 


C*W5    -   '      ~:      ^ 


-^.-IV.-ltsVpffc. 


I 


PHI^   ^  ^b^ 


■Jta™ 


RF  DEVICES 


AEC  1158 


LEDS 

Monsanto  MAN  72  Red  LED 
Readout  300"  High,  Common 
Anode  ONLYS    69 


Monsanto  MV5053 
and  Holder 
LED  Hoiders,  .  ,  ..  . 
Jumbo  Red  LEDS 


JUMBO  LED 
oniy  .25 

10 

e  for  SI. 00 


2N237e 
aN3375 
2N3553 
2N3a66 
2N3g26 
2N4427 
2N55a9 
2N5590 
2N5591 
2N5913 
2N6DeO 
2N60S1 
2N6082 
2N6083 
2N60a4 
2N6094 
2N6095 
2N6096 
2N6097 


10W 

3,0W 

2.5W 

LOW 

7.0W 

LOW 

3.0W 

10W 

25W 

1.75W 

4.0W 

15W 

25W 

30W 

40W 

4.0W 

15W 

30W 

40W 


200  MHz 
4CM3MHZ 
175  MHz 
400  MHz 
175  MHz 
175  MHz 
175  MHz 
175  MHz 
175  MHz 
175  MHz 
175  MHz 
175  MHz 
175  MHz 
!75MHa 
175  MHz 
175  MHz 
175  MHz 
175  MHz 
175  MHz 


T060 

T060 

T039 

T039 

T060 

T039 

MT71 

MTr2 

MT72 

T03G 

MT72 

MT72 

MT72 

MT72 

MT72 

X106  PNP 

X106PNP 

X106PNP 

X106PNP 


$12.35 
5.60 
L40 
1.25 
a  30 
1.36 
4.75 

?.ao 

10.25 

1.70 

5.40 

6.45 

10.95 

12.30 

16,30 

6.50 

8,50 

10.35 

20.00 


ALDELCO  KITS 

DUAL  DIGITAL  12/24  HOUR  CLOCK  KIT 
NOW  WITH  A  NEW  WALNUT  GRAIN  WOOD 
CABINET 


Features: 


n  Si    31  S3   Bl  31 


—  THE  MIMIC  — 

PROGRAMMABLE  IAMBIC  MEMORY  KEYER 


Jumbo  Gfeen,  Orange  or  Yeifow 
LEDS 5  tor  $7. 00 

FETS 

40673 .....1.55 

MPF102 .    .55 

2N3ei9 35 

2N5457 50 

2N545e  , 50 

2rsl5459 55 

3N5485 50 

DARLINGTON 

MPSA   13 - 60 

MPSA  14 .  ..40 

2N5306 50 

SCR 

CIOGA. 55 

C106Q...... 65 

C  122B ,85 


•  Four  memory  inputs,  sixty  let- 
ters each 

•  Five  minutes  of  memory  #  10 
wpm 

•  Operates  on  110  V  ac  and  6-16 
vdc 


•  Triggered  ciock  for  memory  re- 
cording 

•  Built-in  side  tone  monitor 

•  Speed  controi  5  to  40-plus  wpm 

•  Two  to  three  Hmes  the  memory 
of  nearest  competitor 


Comes  in  attractive  iight 

biue  cabinet  measuring 

2y2  '  high  x  4"  wide 

X  5"  deep. 


12  or  24  Hour  Operation  on  either  clock 
Each  Clock  separately  controHed 
Freeze  feature  for  time  set 
Easy  assembiy  tor  clock  and  cabinet 


BIG 
0.5  LEDS 


MODEL  ALD5-W      ONLY  $49.95 


KIT  ONLY  $7e.9S 


Kft^ith  set  of  paddles 
Assembled  unit, .._,.. 
Peddles  onljf 


$104.95 

. .  99.&5 

.  29.95 


VOLTAGE   REGULATORS 

TO220  Package 

Positive  $1.00  Negative  $1.25 

7805  7905 

7S06  7906 

7808  7912 

7812  7915 

7815  7913 


CLOCK  CHIPS 

5313 3,49 

5314 349 

5316  .............._....  .3-95 

5375, 3.95 

CT7001 6.95 


2200  MFD  16  volt 
Radial  Cap  3  forS9q; 


ALARM  CLOCK  KIT 

6  Big  0.5  LEO  Displays  *  On  Board  AC  Transformer  "  12 
Hour  Formal  with  24  Hour  Aiarm  *  Snooze  Feature  *  Eiaps- 
ed  Timer.  Timer  feature  makes  this  Popular  in  Broadcast 
Stations.  It's  a  naturai  for  cars,  boats  and  campers  when 
used  with  optionai  crystal  tfime  base,  Fits  our  standard 
cabinet.  319,95 

Crystal  time  base  when  purchased  with  c  iock.  $2,95 

12  or  24  HOUR  DIGITAL  CLOCK  KIT 

Uses  0,5  Dispiay  LED,  5314  Clock  Chip.  Freeze  feature  for 
accurate  set,  fitsour  standard  cabinet,  ONLY$ia.95 

CLOCK  CABINETS  ea,$4,95 

Woodgrain  or  btacl^  leather 

CRYSTAL  TIME  BASE  KIT 

includes  PC  Board,  Crystai,  all  parts  and  instruc- 
tions. $4.95 


CLOCK  FILTERS 

Biue.  Red,  Green,  Amber  ot  Smoke 

Blinky  Flasher  Kit 

PC  board,  555  &  all  parts  workg  on  9  voK&-  Mouse 

$1.00 


$.60 

$295 
on— 


DIGITAL 
MULTIMETER  & 
THERMOMETER 

3Vi  Digit— 5  ranges  on  each 
function  AC^DC  .2  Volts  to 
2000  Volts  Current  2 
Microamps  to  2  Amps 
Resistance  2000  Ohms  to  2 
Megohms,  includes  PC 
Board,  ICL7107  Chip  and  all 
parts.  Only  $49.95 


LOGIC  PROBE  KIT 

Measures  Logic  1,  Logic  0, 
and  pulsing  circuit  Condi- 
tic  n  s  N  O W  red  u  ced  to    $9.95 


SPECIALS 

MC1458P 29 

655T(mer^ 3  for  $1.00 

4011 .23 


CRYSTAL  SOCKETS 

HOLDS  8  HC25U      -   S  .^^ 

SmgieHC25U 29 


144  MHz  10  Walls 
RF  Transistor 
2N55dO  $5.50  ea. 


NEW! 


Tunable    420    MHz 
Fast  Scan  TV 
Converter 


Receive  Fast  Scan  Amateur  TV  in  the  420  to  450  MHz  Band 
with  any  TV  set.  Low  noise,  high  gain  rf  Amp  with  Varactor 
tuned  input  and  outputs-  9uMt  in  AG  syppEy,  Comes  in  two  tone 
walnut  &  beige  catjinet  measuring  1  7/8"  x  4  1/4"  x  AVb'' 
Factory  wired  with  2  year  guarantee. . $59.95 


Self  Completing  Dots  &  Dashes 

Samtjic  Operation 

Single  Dot  &  Dash  Memories 


AC CU KEYER 
KIT 


Provision  for  attachment  of  256  or  512 
Bit  Memory  for  DX  or  Contest  work 


ADJUSTABLE  POWER  SUPPLY  KITS 


5-1&Volts500MA 
12  2&Vo(ts500MA 


$6,95 
e.95 


Revised  version  of  the  Accukeyer  featured  rn  the  ARRL  Handbook.  Has 
more  logical  IC  Layout  and  ON  Board  sidetone  Qsciilator.  Includes  PC 
Board,  TTL  ICs^  S55  Timer,  IC  Soci^ets,  Switch,  Speaker,  Transistors, 
c  apac  I  to  rs  and  res i  stor s ,  R  eq  u  I  res  5  V  DC.  ON  LY  S 1 9, 95 

ACCUKEYER  MEMORY  KIT 

Simple  low  cost  Memory  Kit.  Uses  2  programmable  1 101  Memory  chips.  Pro 
vides  2  canned  messages  of  30  Characters  each.  Adaptable  to  Handbook 
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313 


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•  INTRODUCTION  TO  RTTY— BK7380— A  beginner's  guide  to 
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•  THE  NEW  RTTY  HANDBOOK-"BK7347-is  a  new  edition  and 
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been  changing  radically  and  has  made  all  previous  RTTY  books  ob- 
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alike.  $5.95/ 

•  PROPAGATION   WIZARD'S    HANDBOOK— BK7302— by   J.    H. 

Nelson.  When  sunspots  riddled  the  worldwide  communications 
networks  of  the  I940'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  look  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  least  understood  facets  of 
amateur  radio.  J.  B.  Wilson  presents  several  methods  of  sideband 
generation,  amply  illustrated  with  charts  and  schematics,  which 
will  enabte  the  ambitious  reader  to  construct  his  own  sideband 
generator.  A  must  for  the  technically-serious  ham.  $5-50/ 

•  SSTV  HANDBOOK— BK7354(hardcover),  BK7355{SoftCover)— 
This  excellent  book  tells  all  about  It,  from  its  history  and  basics  to 
the  present  state-of-the-art  techniques.  Contains  chapters  on  cir- 
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more.  Hardbound  $7.00.  softbound  $5.00.* 

•  WEATHER  SATELLITE  HANDBOOK— BK7370— Simple  equip- 
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Taggart  WB8 DOT, $4,95.* 


ANTENNAS 


•  73  DIPOLE  AND  LONG-WIRE  ANTENNAS— BK1016— by  Ed- 
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•  73  VERTICAL,  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- 
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line  tuners,  as  well  as  methods  for  measuring  resonant  frequency, 
velocity  factor,  and  standing-wave  ratios.  160  pages.  $5.50.* 

•  VHP  ANTENNA  HANDBOOK— BK7368— The  NEWVHF  Anten- 
na Handbook  details  the  theory,  design  and  construction  of  hun- 
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written  for  the  average  amateur  who  takes  joy  in  building,  not  full 
of  complex  formulas  for  the  design  engineer.  Packed  with 
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TEST  EQUIPMENT 


•  RF     AND     DIGITAL     TEST     EQUIPMENT     YOU     CAN 

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•  VOL.  I  COMPONENT  TESTERS— LB7359— .-.  how  to  build 
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criD  mieTniuicD  ecDifir«i 


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•  SSB  . , ,  THE  MISUNDERSTOOD  MODi 
—  BK7351— by  James  B.  Wilson.  SmgJe 
Sideband  Transmisston  . . .  tJiousands  ol 
us  use  it  every  day^  yet^  it  remains  one  of 
the  least  undefstood  facets  of  amateur 
radio.  J  B.  Wilson  presents  several 
methods  of  sideband  generation,  amply  il- 
lustrated with  charts  and  schematics, 
which  wil)  enable  the  ambitious  reader  to 
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must  for  the  technically-sefious  ham. 
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•  PROPAGATION  WIZARD'S  HANDBOOK 

— BK7302— by  J.  H.  Nelson,  When  sun- 
spots  riddled  the  worldwide  communica- 
tions networks  of  the  1940's,  John  Henry 
Nelson  looked  to  the  planets  for  an 
answer.  The  result  was  a  theory  of  propa- 
gation forecasting  based  upon  mterplan* 
etary  alignment  that  made  the  author  the 
most  reliable  forecaster  in  America  today. 
The  book  provides  an  entightened  look  at 
communications  past,  present,  and  future, 
as  well  as  teaching  the  art  of  propagation 
forecasting.  6.96.* 


•  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  ex- 
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probes  .  .  .  JUST  ABOUT  EVERYTHING 
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A47    Aluma  Tower  Company 290 

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A2G   Am idon  Associates , 113 

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A6     Aptron  Laboratories 279 

A50    Associated  Radio 308 

A64    Aureus  Elec,  IncJEdgecorti . , .  71 

B1      Babylon  Electronics 288 

B23    Baj-ker-Williamson 191 

B32    Bay-Com , 2B0 

B41    Belden .....272 

B29    BrHt's  2'Way  Radio 178 

08      Bullet  Electronics 296, 297 

G30  Burghardl  Amateur  Center. . .  225 
CBS    C  &  A  Electron  tc  Enterprises  .  205 

C3      Clegg.    ....    ,. 125,179 

C21    Coakit ...  280 

C95    Cohoon    Amateur   SupplyiEdge- 

com , 47 

C75    Com m  Center,  Laurel 232 

C106  Command  Productions 279 

C105  Communications&TVUnltd  . -276 

Cse    GommuniGationsCtr,  NE  ,  249, 273 

C96    Communications  Center,  NE^ 

Edgecom  . »...,,,.....,. ....  .69 

05  Communications  ElectfOni OS  .  159 
C89  Communications  Sen/ices  , , . ,  202 
C6      GOTTimunications  Specialists  24, 25 

C90    Curtis  Electro  Devices .140 

Dade  County  Hamfest . . , ,  190 

D6      Peter  W.  Dahl  Company 1 71 

D10    Davis  Eiectronics 290 


D35  Day  tap  ro  Electronics,  Inc 283 

D39  Jim  DeNinno  &  Co. 279 

D15  DenTron 5 

D29  Dfeiectric 211 

D20   Digital  Research  Corp 302, 303 

D23   Dovetron ..... 77 

D11    R.L  Drake  Company 94,95 

D25   DSl  instruments 21,220,221 

El  ECM  Corporation  .._,,,..  75, 79 

E19    Edgecom 35 

E12  Engineering  Specialties  ......  312 

F5     Fles her  Corporation  _ 265,283 

G 1 2  Germanto  wn  Am  ate  u  r  Su  p  ply  .171 

G20  G  &G  Radio  Electronics  Co  . . .  281 

G22   G.iS.M.0 282 

G23  Globaiman  Products 211 

G4     God  bout  Electronics 304 

HAL Gornmunications Corp.  ...76 

H24  Hai'Tronix 263, 265 

H2     Ham  Radio  Center 215.291 

H31   Ham  Radio  Outlet. 289 

H16   Hamtronics,  NY 299 

HS  Hamtronics,  PA ........ .  236^245 

H26   HartvweiisOfficeWorid 290 

H30  HeuerTime  &  Eiectronics 158 

H3     Henry  Radio  ........ Gil,  117 

H32  Hobby  Systems 279 

H4  Hy  Gain  Electronics .........  45 

i1       ICOM .,.17 

132     Instant  Software 180, 181 

19       Integrated  Circuits,  Unltd 306 

127     IRL 23 

J 1  Jameco  Electronics ..........  305 

J2     Jan  Crystals. 140 

JS      JRS Electronics ,  .75, 260 

K13  Kantronics 163 

Kilobaud 16& 

Kenwood.-.. CIV,  6^13 

K1 4  Key  Electronics , .  .281 

L18    Lafayette ........ .2i 


:^ 


L9     Long  s  Electronics 194-199 

Li  7  Lunar  Electronics 60 

M35  Madison  Electronics  Supply  .  139 
M36  MaggioreEiectronlcLab  ....229 

M71  Matric . . , . ._.,_...  54 

M52  MFJ  Enterprises 45, 103, 282 

Ma    MHZ  Electronics 292,293 

M69  Micro  Control  Specialties. . . .  279 

M48  Microtfonics 19, 281 

M62  Mid  Com  Efectronics,  IncJEdge- 

oom ._...,.,................  .63 

M41  Midland  International ,..,,.  .233 

N2     NeW'Tronics ...  141 

N14  Northern  Radio  . . 265 

05    OK  Machine  StTooi 171,173 

03    Optoetectronics,  Inc 301 

P15  Pace-Traps . 281 

P30  Paiomar  Electronics  .... 138 

Paiomar  Engineers,*... 19 

P41    P.C.  Electronics. 75 

P2     Poly  Paks  .... 309 

P25  Printed  Circuit  Products . . , .  280 

P21   Priority  One 151, 153 

Q3     Quest  Electrontcs 294 

B1     Radio  Amateur  Gailbook,  Inc.. .  31 1 

Radio  Worid..... ...,,75 

RIO  Raintx)w  Industries , , ,  77 

R8     Ramsey  Electronics. 29, 298 

R25  F.  Reichen  &  Saies 307 

R27  RF  Power  Labs,  Inc 276 

R.  Lee  Tower  International ..,  283 
R15  Roim  Distributors. ...... . . .  .290 

R21   Hush  Electronics  . . ! 288 

HI 8  R.  W.  Electronics,  Inc.  . 279 

S63  Semiconductors  Surplus  314,315 

S3     Sentry ,  76. 282 

S39  Sere-Rose  &  Spencer  Eiec. ...  281 
S  33  S  F  Am  at  eur  R  ad  io  Servi  ces  75, 264 

S58  Shakespeare  ,.,.,,.... 257 

S70  Signetics 272 


S4      Slep  Elecironlcs  Co 178 

S8     Spectrum  Com 1 10, 1 1 1 

S10    SST  Electronics 87, 98. 89 

S50    O.  C.  Stafford  Electronics 281 

S1 8    Standard  Communications  . .  190 

S38   Stuart  Electronics , ,  288 

S43   Surplus  Eiectronics 310 

TenTec 135 

T34   Thomas  Communications  . . .  261 
T48    Tower  Electronics  Corp. .....  1 13 

T44   Tower   Electronics   CorpJEdge- 

com 43 

T18  Trac  Electronics  J  nc  . 79 

T35   Trans  Com —  280 

T3     Tufts  Radio  Eiec.  . . .  232, 266-269 
145  Tufts  Radio  Electronics/Edge- 

com ,    . .  59 

U2    Unarco-Rohn 283 

Ue     United  Products  . , .  - 295 

ue     U  n  I VG  rsal  Am  at  eu  r  R  ad  io  Servi  ce , 

inc 79 

VI     Vanguard  Labs 75 

V5     VHP  Engineering .......  27 

Via  VHF  Engineering/Edgecom . .  .55 

WIS  Wacom. ,....,...  78 

W17  Westcom  Engineering, , . .  42, 140 

Vtfia  Western  Electronics 79, 280 

W2    Wilson  Eiectronics 3 

Y 1      Y  ae  E  u  E I  ectron  I  cs  CJoqp^ CI  H 

21      Z22  Electronics,  Inc. 264 

From  73 Pages  77,  259. 316-322 

^Reader  Servi€«  inquiries  not  honored. 
Please  contact  ad  vert  is  er  directly. 


/^ 


BK1016 

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ST2500 

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ST 1000 

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B  K7302 

QW0250 


73  DIPOLE  &  LONG  WIRE  ANTENNAS  ....,.$  5.50 

73  BACK  ISSUE, $  3,00 

73  BACK  ISSUES— 25  OUR  CHOICE $10.00 

73  BACK  ISSUES— 5  YOUR  CHOICE . .  $  5.00 

73  BACKlSSUES-10  YOUR  CHOICE $12.00 

73  BACK  ISSUES— 25  YOUR  CHOICE $20.00 

BEHIND  THE  DIAL $  4,95 

BINDER— 73— 1 ,$  6.50 

BINDER— 73--2&UP $  6.00 

CHALLENGE  OF  160 $  4.95 

CODETAPE— 5 WPM $  4.95 

CODE  TAPE— 6  WPM $  4.95 

CODETAPE— 10  WPM $  4.95 

CODE  TAPE— 13  WPM $  4.95 

CODE  TAPE— 20  WPM $  4.95 

CODE  TAPE— 25  WPM $  4.95 

CODETAPE— LEARN  MORSE  CODE $  4.95 

CODE  TAPES  (ANY  FOUR  ABOVE) ,$15.95 

GUIDETO  HAM  RADIO $  4.95 

HOW  TO  BUILD  A  MICROCOMPUTER $  9.95 

IC  OP  AMPCOOKBOOK $12.95 

INTRO  TO  RTTY $  2.00 

NOVICETHEORYTAPES $15.95 

PRACTICAL  TEST  INSTRUMENTS $  4.95 

PROPAGATION    WIZARD'S  HANDBOOK. .  $  6.95 
QSL  CARDS— STYLE  W— 250 $  8.95 


QW0500 

QX0250 

QX0500 

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QSLCARDS— STYLE  W— 500 , . .  . ,  $13.95 

QSL  CARDS— STYLE  X— 250 ......$  8.95 

QSL  CARDS— STYLE  X— 500 ........,.,.,.  $1 3.95 

QSL  CARDS— STYLE  Y^250. .$  8.95 

QSLCARDS— STYLE  Y— 500. .... , ... . . , . .  $13.95 

REPEATER  ATLAS  $  1.95 

RF  DIGITAL  TEST  EQUIPMENT $  5.95 

RTTY  HANDBOOK .......$  5,95 

SHELF  BOX— 1 ,  $  2.00 

SHELF  BOX— 2 , $  1.50 

oiH  tL_r  otJA^ — o  Ui     .■i..i..i.i...,i..* *   1  .tD 

SSBTHE  MISUNDERSTOOD  MODE $  5.50 

SSTV  HANDBOOK  (HARDCOVER) , .  .  $  7.00 

SSTV  HANDBOOK{SOFTCOVER)  ..,......$  5.00 

SSTVTAPE , . , . . , $  5.95 

STUDY  GUIDE— ADVANCED  CLASS $  5.95 

STUDY  GUIDE— EXTRA  CLASS $  5.95 

STUDY  GUIDE— GENERAL  CLASS  .$  5.95 

STUDY  GUIDE— NOVICE  CLASS  ..........$  4.95 

TEST  EQUIP  LIB  VI  —COMP TESTERS  .....$  4.95 

TEST  EQUIP  LIB  V2— AUDIO  TESTERS $  4.95 

TEST  EQUIP  LIB  V3— RADIO  EQUIP $  4.95 

TEST  EQUIP  LIB  V4— ICTEST  EQUIP.  ......$  4.95 

VERTICAL  BEAM  &  TRIANGLE  ANTNS $  5.50 

VHF  ANTENNA  HANDBOOK ......,.-.$  4.95 

WEATHER  SATELLITE  HANDBOOK $  4.95 


322 


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immuiumiummiVhi«iiinMii«iiniuii 


4i 


^  ^\\S\\\\\\\\\\\\\ 


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mmy  Load/Wattmeter;  SP-101 PB  Speaker/Patch;  FT-IOI E  160-10M  Transceiver  with  YC-601B 
'ounter;  FV-101B  External  VFO;  YO-101B  Station  Monitor;  FTV-250  2-Meter  Transverter;  FTV-650B  6- 
R-101  Digital  160M-10M  Receiver;  FL-101  Ali  Band  Transmitter, 

il  Coverage  Receiver;  FRG-7000  General  Coverage  Digital  Receiver;  FP-301  13.8VDC  Power  Supply; 
0-10M  Transceiver;  FV-301  External  VFO;  FT-301D  Solid  State  Digital  160-10M  Transceiver;  FP-301  D 
ly  with  Clock  &  Identifier;  YO-301  Station  Monitor;  FC-301  Antenna  Coypler;  LL-301  Landliner  Phone 
r  Supply. 

e  Band  Transverter:  FV-901DM  Synthesized  Scanning  VFO;  FT-901DM  160-10M  The  Smart  Radio" 
Station  Monitor/Analyzer;  FC-901  Antenna  Coupler;  SP-90tP  Speaker/Patch;  QTR-24  World  Clock; 
adset;  YD-844A  Hi/Lo  Imp.  Desk  Microphone;  YD-14S  Ht/Lo  Imp.  Flexible  Neck  Desk  Microphone. 

d  Held  2M  Transceiver;  YC-500E  High  Precision  Frequency  Counter;  FT-227R  2M  FM  Mobile  Trans- 
er;  FT-227RA  2M  FM  Mobile  Scanning  Transceiver-4  Memory;  CPU-2500R/K  2M  FM  Mobile  Com- 
r;  FT-7  20 W  PEP  Mobile  Transceiver;  FT-225RD  2M  All-Mode  Digital  Transceiver;  FT'625RD  6M  All- 
giver. 


r/Microphone  (FT-202  Accessory);  YM-2500  Keyboard  Microphone;  FFDX-50  52  Ohm  Low  Pass  Filter 


THE  CHRISTMAS  GIFT  OF  A  UFETIME! 

YAESU  ANNOUNCES  THEIR  SENSATIONAL  COMPUTER  AGE 

CPU-2500R/K  2-METER  25  WATT  TRANSCEIVER 


Again,  Yaesu,  THE  RADIO,  takes  a  giant  step  fonvard  with  thetr  computer  age  4-bit  Central 
Processor  Unit  controlling  the  Phase  Locked  Loop.  It  allows  selection  of  800  PLL  channels 
with  touch  button  station  selection  built  into  the  optional  keyboard  mike  .  .  .  PLUS  auto- 
matic scan,  up  or  down  across  the  entire  2  meter  band  .  .  .  PLUS  four  memory  channels 
.  .  .  PLUS  optional  tone  squelch  encoding  .  .  .  PLUS  tone  burst  .  ,  .  PLUS  high  SWR 
and  reverse  voltage  polarity  protection  .  .  .  PLUS  3/25  watts  of  power  .  .  .  PLUS  fixed 
±600  KHz  offsets  .  .  .  PLUS  programmable  offsets  .  .  .  PLUS  tone  pad  microphone 
option  .  .  .  PLUS  bright  3/8"  LED  six  digit  frequency  display  and  another  LED  for  memory 
display  .  .  .  and  much  more. 

The  CPU-2500R/K  is  a  space  age  radio  for  discriminating  amateurs  utilizing  the  latest  solid 
state  techniques  and  it's  on  your  dealer's  shelf  today ! 


Pric«  And  Specifications  Subjed  To 
Change  Without  Noiiee  ot  Obligation 


wsu 


I 


YAESU  ELECTRONICS  CORP.,  15954  Downey  Ave.,  Paramount,  CA  90723  •  (213)  633-401 
YAESU  ELECTRONICS  Eastern  Service  Ctr., 981 2  Princeton-Glendale  Rd., Cincinnati,  OH  452' 


iiE^ffncl 


tt^mmmm^i^^m^M 


Price  And  Specjtications  Subjecl  To 
Change  Wifhout  Notice  Of  Obligation 


W 


TAISU 

YAESU  ELECTRONECS  COBPORATION 

15954  Downey  Avenue,  Paramount^  CA  90723  (2X3)  633-4007 

EASTERN  SERVICE  CENTER 
9812  Prtnceton-Glendale  Rd. ,  Cincinnati  OH  45246 


Lett  to  Right 

Top  Row :YP- 158" 
Display/Frequent 

Meter  Transvertei 

Row  2:  FRG-7  Gei 
FT-301  Solid  State 
13.8VDC  Power  Si 
Patch;  FP-4  4A  Pi 

Row  3:  FTV-901  T 
Transceiver;  YO-9 
YH-55  Super  Soft 

Row  4:  FT-202R  i 
ceiver  "The  Mem 
puterized  Transci 
mode  Digital  Trar 


Row5:YM-24Spc 


I 


1278C 


Mm 


MA 


MHz 


« 


MIC^ 


EVERY  FEATURE  YOU  COULD 
POSSIBLY  WANT  IN  A  2-METER 
FM  RIG  IS  AVAILABLE  NOW  IN 
THE  KENWOOD  TR-7600 


-« 


The  new  TR-7600  gives  you... 

•  Full  i-mi  coverage  t144.000"147  995  MHz)  on 

2  meters  «  800  channels  •  Dual  cDncentric  knobs 
for  fast  frequency  change  [lOQ-kHz  anct  10-kHz  steps} 

•  5-kHz  offset  switch  •  MH^  selector  switch. .Jor 
desired  band  (144*  145, 14G,  or  147  MHz) «  Mode  switch 


for  operating  simplex  or  for  switching  the  transmit 
frequency  up  or  down  600  kHz  for  repealer  operation.,. 
or  for  switching  the  transmitter  to  the  frequency  you 
have  stored  in  the  TH-7BQ0's  memory  (while  the 
receiver  remains  on  the  frequency  you  have  selectett 
with  the  dual  knobs)  *  Memory  channeL.with  simplex 
or  repeater  (pfus  or  minus  BOO  kHz  transmitter  offset) 
operation. 

The  optional  RIH-76  Microprocessor  Control  Unit 

provides  more  operating  features  to  the 

TR-7B0O  2-meter  FHfl  trafisceiver  than  found  in  any 

other  rig!  Vith  the  Microprocessor  Control  Unit 

attached  to  your  TR-7600,  you  can... 

•  Select  any  2-nii?ter  frequency «  Store  frequencies  in 

six  memories  •  Scan  afl  memory  channels  •  Auto- 


NWOO 


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^  OM 


$  kHr 


TR-Tc  .c:> 


Actual  Size 


RM-76 
Microprocessor 
Control  Unit 


matjcally  scan  up  all  frequencies  m  b-kHz 

•  Manually  scan  iip  or  down  m  5*kHz  steps  *  ox^i  lower 
and  upper  scan  frequency  limits  •  Hesel  sc.        144  MHz 

•  Stop  scan  (with  HOLD  button)  •  Cancel  scan  (for 
transmitting)  •  Automatically  stop  scao  on  first  busy 
or  open  channel  * 


Subjecf  io  FCCv  u^^- 


•  <3f 


TRIO  KENWOOD  COMMUNICATfONS  J 


\f^^ 


1111  WEST  WALNUT/COMPTON    TA  90220 


^KEIM\A/00 


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