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I 


I 


#123 

One  Dollar 

December 

1970 


I 


iSB  EMPHASIS: 

feuiLOYOURDWN 
SOLID-STATE  EXCITER 

IVDELTAf'SSB  CONTROL 

YOUR  "SECOND"  LINEAR 

OFFSET  TUNING  for  HW  100 


PLUS 


FM  •FUN  PROJECTS  •  HUMOR 


GIANT  1970  ARTICLE  INDEX 


'•'v.-Wwi^^ ■**WA=;' 'i,*;  ;7:^^ .V    .:--•. ■.liV:- 


SWAN 


270B 


SSB  TRANSCEIVER 

The  5  band  deltis:e  270-B,  with  a  power  rating 
of  260  Watts  P.E*P,,  is  a  complete  self  con- 
tained radio  station  wifli  imHt^in  AC  power 
supply  and  speaker  in  one  compact,  portable 
package.  You  can  take  it  with  you  on  vaca- 
tion or  business  trips,  operate  from  your 
motel  room^  your  boat,  car,  or  hide-away 
cabin.  AH  you  do  is  connect  to  an  AC  power 
source  and  antenna^  plug  in  your  mike  and 
y ou^re  on  the  air,  with  enough  power  to  work 
the  world. 

The  Swan  Cygnet  270B  is  a  world  traveler. 
And  the  price  h  a  w<Hrld  beater!  $499 


ELECTRONICS 

305  Airport  Road 

Oceanside,  California  92054 

A  Subsidiary  of  Cubic  Corporatron 


SWAN  1 200W 
1200  WATT  LINEAR 
AMPLIFIER  WITH  SELF 
CONTAINED  AC  POWER 
SUPPLY 

We  built  this  little  gem  to  go  with  our 
Cygnet  270B*  But  when  word  got  around 
that  Swan  had  a  1200  Watt  amp  with  a 
built-in  AC  power  supply,  for  just  two 
hundred  and  ninety -five  bucks,  all  h— 
broke  loose*  Production  has  finally 
caught  up  with  sales  again,  so  see  your 
dealer  soon. 


ELECTRON  ICS 
305  Airport  Road 
Oceanslde,  California  92054 
A  Subsidiary  of  Cubic  Corporation 


#123  December,   1970 


Featu  res 

2  Radio  Amateur  News  Page 
8  Caveat  Emptor 
10  Never  Say  Die 
12  Mr  Virgo  Himself 
14  Leaky  Lines 
90  New  Products 
115  Letters 
128  Propagation  Chart 
128  Advertiser  Index 


Editor*Publisher 

Wayne  Green  W2NSD/1 

Managing  Editor 

Ken  Sessions  K6MVH/1 

STAFF 

Associate  Editor 
Jim  Kyle  K5JKX 

WTW  Editor 

Dave  Mann  K2AGZ 

FM  Editor 

Mike  Van  Den  Branden 

Advertising 
Diane  Shaw 
Roci  Billings 
Hilary  Wye 

Advertising  Representatives 

Bill  Fields 
Manfred  Meisels 
Andrew  McCr eight 

Art  Director 

Roger  Block 

Graphic  Arts 
Nancy  Estle 
Jan  Wozmak 

Composition 
Ruthmary  Davis 
Karen  Mellor 


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75 


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107 


108 


.  W4NVK 


.  K3KM0 


WBeBIH 


Contents 

Solid  State  Exciters W6YUY 

For  The  build-don't-buy  crowd. 

Solid  State  Control  for  SSB  Exciters 

For  really  smooth  tuning. 

Hams  Are  A  Funny  Bunch  of  People 

Except  me  and  thee. 

A  2  Meter  Minitransmttter . ,  * . , 

Hand  portable  for  FM  repeaters. 

Receiver  Offset  Tuning  for  the  HWlOO    WA2EAW 

For  tuning  in  oldtjmers  who  can't  stay  on  frequency. 

The  Little  Gate  Dipper .VV5ETT 

1.7  -  225  MHz    GDO  with  no  G, 

Clinks  In  A  Vacuum  ...,,,.,..,.• 
The  wife's  view  of  amateur  radio. 

Your  Second  Linear » ,  > 

Usfng  the  fabulous  RCA  3-5002. 

General  Class  Study  Course    ..,,,.. 

Vacuunn  tubes„. remember  them? 

Yipes,  it  Talks      _  _ , .W2F 

Startle  your  friends. 

Regency    —   An  FM  Late  Starter    . .  , 

Wow? 

Transistor  tester,  simple. 

Two  Terminal  Current  Li  miter  * .... 
Most  Have  three^  so  this  is  a  step  ahead,  right? 

Index  to  Articles  in  1970 
Ridiculously  detatted  yearly  index» 


Derf  ler 


W4AYI 


Staff 


. K61V1VH 


.  .- W6QPF 


.  .  .  .  Gerald  Beene 


I 


Drafting 

R.  K.  WJIdman  W6MOG 
Wayne  Peeler  K4MVW 
T;M.  Graham  WSFKW 

Subscriptions 

Dorothy  Gibson 

Circulation 
Phil  Price 

Comptroller 

Georgiana  Sage 

Publications 
Jeff  Parsons 
Biff  Mahoney 
Hal  Flagg 

Traffic 
Taylor  Sage 

Propagation 

John  Nelson 


73  Ma^aiine  is  published  monthty  by  73  Inc.,  Peterborough 
New  Hampshire  0345S,  Subscription  rates  are  $6  for  one 
year  in  North  AmericQ  and  U.S,  Zip  Code  areas  overseas,  $7 
per  one  year  elsewhere.  Two  years  $10  in  ij\S.  and  S/2 
ovei^eas.  Three  years  S/4,  and  $16  overseas.  Second  class 
postage  paid  at  Peterborough,  NM,  and  at  additional  mailing 
offices.  Printed  at  Menasha,  Wisconsin  5 -J 95 2  U.S. A,  Entire 
contents  copyright  1970  bv  73  /ric,  Peterborough,  NJL 
0345H.  Phone:  603^924^3813,  We  could  hassle  you  about 
subscribing,  ^ivin^  gift  subscripti€>ns,  bunging  passible  adver- 
tisers and  all  that,  but  we  won't,  if  you  want  to  go  through 
the  next  month  with  one  of  the  blackc^^l  curses  known  to 
man  on  your  head  (hen  all  you  have  to  do  ts  ignore  73.  .  .do 
not  subscrilje,  .  .do  not  send  in  ten  gift  subscriptions  for 
friends  (or  enemies,  dependhig  upon  how  you  think  of 
73).  .  ,do  not  lei  Collins  know  Uiai  you  thought  they  were 
out  of  the  ham  tjusiness  because  they  have  not  advertised  in 
73  in  over  ten  years.  Go  ahead  and  risit  a  curse  so  powerfui 
tiial  it  could  wetl  tiave  a  serious  effect  even  upon  your  family 
two  generations  later. 

The  Cover 
An  impressive  shot  of  the  sky  through  K9JFD's  beam.  The 
photo    was  submitted   by   Mrs,    Gene   Markos  as  a  birthday 
surprise  for  hubby* 


DECEMBER    1970 


1 


Amatmr 


Page 


December  MCMLXX 


Monthly  Ham  News  of  the  World 


73  Magazine 


CHICAGO  OUTLAWS 


RADIO!! 


CHICAGO  AMATEUR 
CLUB  BRINGS  SUIT 

Chicago.  Under  city  zoning  ordinances, 

Chicago  has  forbidden  amateur  radio 
slations  to  be  set  up  in  residential 
areas.  According  to  information  pub- 
[ished  in  the  Chicago  Daily  News,  the 
ban  can  only  be  waivered  on  payment 
of  a  special  $100  fee. 

Proceeding  on  the  grounds  that  such 
anti-ham  legislation  is  unconstitutional, 
a  group  of  Chicago  amateurs  (the 
Chicago  Area  Radio  Club)  filed  suit  in 
district  court,  charging  the  city  with 
attempting  to  reeutate  a  service  that  is 
already  [>eing  regulated  by  the  federal 

fovernment.  The  suit  seeks  to  have  the 
J.S.  district  court  enjoin  the  city  of 
Chicago  from  enforcing  its  ordinance 
and  from  collecting  fees  for  waiving 
such  ordinances. 

in  supplying  this  information  to  73 
News,  Art  Housh older  {K9TRG),  man- 
ager of  Spectronics,  Inc.,  a  Chicago 
area  ham  radio  firm,  said  the  action  of 
the  city  and  the  counteraction  on  tlie 
part    of    the    CARC    were    topics    of 


% 


U.S.  Navy  Radioman  First  Ciass  Larry 
HoUingsworth  sets  up  personal  phone 
patches  for  crew  members  aboard  the 
frigate  Yarnell,  reducing  the  impact  of 
transgiobal  separation  between  family 
members. 


discussion  at  club  meetings  around 
Chicago  and  on  ham  radio  nets.  Most 
of  Ihe  comments,  he  indicated,  were 
directed  against  the  inequitable  city 
ruling.  He  also  expressed  concern  that 
•should  the  court  favor  the  city  rather 
than  the  amateur  operators,  other  met- 
ropolitan areas  might  follow  suit,  deal- 
ing u  crushing  blow  to  amateur  radio. 


NO-MONITOR 
REPEATER 


OPERATION  PROPOSED 

The  editor  of  73,  Ken  Sessions 
(K6MVH),  has  submitted  a  proposal  to 
the  ICC  that  calls  for  toned  repeaters 
to  be  allowed  to  operate  without  the 
requirement  for  UHF  monitoring.  Un- 
der present  rules,  no  remotely  operated 
repeater  may  be  used  unless  the  speci-^( 
fied  repeater  licensee  is  monitoring 
from  the  UHF  control  point  stipulated 
on  his  license.  The  rules  make  it 
impossible  for  the  sole  owner  of  a 
repeater  to  operate  his  repeater  from  a 
mobile  or  from  any  site  away  from  his 
control  point- 
Sessions*  proposal  would  make  it 
legal  for  continuous  monitoring  to  be 
abandoned  when  certain  fail-safe 
measures  and  tone  control  have  been 
incorporated  into  a  repeater  system. 
Tone-burst  and  whistle-on  repeaters, 
under  the  proposed  ruling,  would  re- 
quire no  fixed-control-point  monitor  as 
long  as  effective  automatic  measures 
have  been  incorporated  into  the  re* 
peater  design  to  suspend  operation  of 
the  repeater  when  its  emissions  deviate 
from  the  rules  of  the  Commission, 
Un toned  repeaters  would  continue  to 
fall  under  existing  rules. 


Lucius  Seneca^  an  ancient  philosopher, 
once  said,  "It  is  througli  the  essence  of 
letters  that  friends  are,  in  a  manner, 
brought  together/* 

Although  Seneca  was  talking  about 
letters  one  writes,  his  thoughts  can  also 
be  applied  to  the  call  letters  of  ham 
radio  station  WB^BDH,  aboard  the 
guided  missile  frigate  USS  Harry  E. 
YarneH,  presently  ctrcling  South 
America  on  Unitas  XI  operations. 

Bringing  people  together  via  ham 
radio  and  telephone  patches  is  the 
off-duty  "pleasure'*  of  radioman  Larry 
Hollingsworth,  "It  is  a  pleasure  to  be 
able  to  set  it  up  so  one  of  the  men  on 
the  Yarnell  can  talk  to  his  wife  or 
girlfriend  back  in  the  States,"  empha^ 
sizes  Hollingsworlh. 

Running  WBQJBDH  is  Hollings- 
worth's  hobby.  His  main  job  is  radio 
watch  supervisor  and  controller  at 
Yarnell's  communications  division. 

Instrumental  in  establishing 
wa^BDH  before  Yarnell  departed  her 
home  port  at  Newport,  Rliode  Island, 
HoHingsworth  obtained  an  FCC  license 
and  was  designated  supervisor  of  the 
amateur  radio  activity. 

'it  has  really  been  fantastic,"  Larry 
says.  "We  have  been  gone  two  months 
and  I  have  completed  almost  400  calls. 
It  is  a  real  morale  booster  when  we  are 
8000  miles  from  home," 

Unitas  is  an  annual  training  exercise 
involving  the  United  States  and  the 
major  maritime  nations  of  South 
America.  Larry  and  the  Yarnell  will 
circle  South  America  and  return  to  the 
United  States  in  mid-December, 


A  real  asset  of  the  service  has  been 
demonstrated  in  situations  where  an 
emergency  is  involved.  One  chief  petty 
officer  on  Yarnell  received  a  letter 
from  his  w^ife  saying  they  had  suffered 
a  very  serious  fire  in  their  home.  "The 
letter  lacked  many  details  which  were 
important  to  the  chief  so  we  placed  a 
call  home  via  the  ham  setup,"  Rollings- 
worth  stated. 

A  Navy  wife,  who  is  presently  living 
in  Norfolk  J  Virginia,  and  whose  hus- 
band is  on  the  Yarnell,  in  a  letter  to 
the  YarnelPs  commanding  officer, 
wrote:  ''Larry's  efforts  have  certainly 
helped  bridge  the  miles  between  my 
husband  and  myself,  and  those  four 
wonder  words,  *1  love  you  -  over,* 
have  kept  us  close  in  spite  of  the  miles 
that  separate  us.  It  is  warming  to  know 
there  are  those  who  understand  the 
voice  of  a  loved  one  can  make  a  long 
separation  at  least  bearable," 

"We  really  have  received  out- 
standing cooperation  from  ham  opera- 
tors throughout  the  United  States/' 
the  radioman  said.  "Almost  all  phone 
patch  stations  we  contact  seem  more 
than  willing  to  help  us  place  our  calls.** 

He  does  encounter  the  humorous 
aspect  also-  He  was  talking  to  an 
operator  in  the  midwest  one  evening 
and  the  man  agreed  to  make  phone 
patches  for  Yarnell  men.  However,  the 
operator's  wife  was  using  the  phone 
and  after  ten  minutes  of  idle  chatter 
over  the  airwaves,  HoHingsworth  final- 
ly had  to  thank  the  man  and  sign  oft 

Originally  from  Albia,  Iowa,  Hoi- 
lingsworth  presently  makes  his  home  in 


Middletown,  Rhode  Island,  with  his 
wife  Lynda  and  two  children,  Lee  and 
Lynette. 

Larry  is  anxious  to  talk  to  any 
operators  in  the  world  who  w^ould  like 
to  contact  him  on  the  air  or  by  writing 
to  him  in  care  of  the  USS  Harrv  E. 
Yarnell  {DLG-17),  Meet  Post  Office, 
New  York.  Phone  patches  to  the  States 
are  actively  souglu  and  QSL  cards  are 
available. 


GALAXY  MOVES  TO  LINCOLN: 

Something  Big  in  the  Offing? 


LincoJn  NB.  The  acquisition  of  Galaxy 
by  Hy-Gain  is  now  complete,  according 
to  R.  A,  Kobold,  spokesman  for 
Hy-Gain  Electronics.  The  company  has 
brought  all  Galaxy's  operations  from 
Council  Bluffs,  Iowa  to  Lincoln, 
Nebraska.  Kobold  hinted  of  some 
sparkling  new  products  to  be  evolving 
from  the  merger,  but  would  not  be 
specific  as  to  detail. 

Galaxy  watchers  seem  to  think  an 
unveiling  of  something  new  could  take 
place  at  the  big  SAROC  convention  in 
Las  Vegas  this  coming  January.  Ac- 
cording to  reports  from  within  Hy» 
Gain's  executive  offices,  the  company 
has  reserved  six  bootlis  for  the  occa- 
sion. This  ^^extravaganza"  attitude 
could  point  to  an  announcement  of 
something  the  company  feels  spectacu- 
lar. 


Page  One 


AMATEURS  IN  ACTION 


Coast  Guard  Commends  Ham 
For  Meritorious  Service 


Washington,  D.C.  Admiral  P.  G.  Prins 
Ivds  personally  expressed  tlianks  on 
behalf  of  the  U.  S.  Coast  Guard  to  J.  P. 
Corrigan,  a  radio  amateur  who  pro- 
vided communications  with  a  ship  at 
sea  during  a  personal  shipboard  emer- 
gency* 

In  a  letter  to  Corrigan,  the  admiraf 
reported:  "On  the  afternoon  of  August 
26,  it  was  reported  that  the  radio 
operator  on  ithe  ship)  Stella  Lykes  had 
apparently  suffered  a  heart  attack.  This 
denied  normal  communications  with 
tlie  sliip  and  required  tliat  all  inforina* 
tion  be  passed  through  the  ship's  ama- 
teur radio.  From  that  time  through  the 
evening  of  August  29,  when  the  sdip 
arrived  in  Honolulu  and  transferred  the 
patient  ashore,  you  maintained  highly 
effective  communications,  passing 
medical  advice  for  the  U.  S.  Public 
Health  Service,  rescue  operations  infor* 
ma  tion  for  the  Coast  Guard,  and  port 
arrangements  for  the  ship*s  agent, 
Oahu  Railway  and  Terminal  Ware- 
housing Company." 

By  way  of  expressing  the  apprecia- 
tion of  the  Coast  Guard,  Admiral  Prins 
said,  "'Your  diligence  and  constant 
willingness  to  help  are  noted  with 
pleasure.  I  fee)  that  this  has  been  an 
outstanding    display    of   the    humani- 


tarian spirit  of  amateur  radio  operators 
everywhere/' 

Copies  of  the  admiral's  letter  were 
sent  to  the  Lykes  Brothers  Steamship 
Company,  employer  of  the  cited  ama- 
teur, to  Oahu  Railway  and  Terminal 
Ware liou sing  Company;  and  to  the  U. 
S.   Public  Heallh  Service  in  HonoIuhL 


KARLY  73  BRINGS  $25! 

Tlic  January  196!  issue  of  73,  good 
copies  of  which  sold  just  three  years 
i'^!>  for  as  little  as  $10,  now  is  bringing 
^i:>.  This  issue,  one  of  the  rarest  of  tlie 
early  73  issues,  was  bid  to  the  S25 
price  at  the  ham  auction  at  the  ARRL 
National  Convention.  This  issue  feat- 
ured the  first  published  circuit  for  the 
RCA  Nuvistor  and  was  in  wide  demand 
during  the  early  60s*  Now,  with  JFETs 
and  Ihirigs,  the  issue  is  more  of  value  as 
a  collector's  item.  The  article  on  using 
the  Efco  modulator  with  the  Johnson 
6N2  also  helped  make  that  particular 
issue  rare. 


HAM  OPERATOR  HELPS 

BOY  GET  CRITICAL 

OPERATION 

tBeprinted  from  Florida  Skip) 
by  WA4ABY 

Josef  Darmcnto  (W4SXX)  has  won 
the  recognition  of  his  community  and 
the  plaudits  of  the  ham  radio  fraternity 
for  his  assistance  in  helping  a  small 
Italian  child  receive  a  crucial  heart 
operation.  His  able  use  of  ham  radio 
paved  Ihc  way  for  4*y ear-old  Fabio 
Piampiani  to  undergo  a  heart  operation 
last  month  by  Houston's  famed  Dr, 
Michael  Deliakey. 

On  June  9  Joe  intercepted  an  urgent 
plea  on  20  meters  from  I IBAX,  Roger, 
a  doctor  in  the  Adriatic  Sea  fishing 
village  of  Civiianove.  Roger  outlined  to 
Joe  that  the  ctiild  had  an  atrophied 
right  ventricle  and  would  die  if  he 
didn't  get  an  operation  within  three 
montiis.  Responding,  W4SXX  then 
contacted  his  wife  visiting  in  Austin, 
Te^M  wliu  in  turn  talked  with  Dr, 
DeBakey  in  Houston-  The  famous  pio- 
neer of  heart  transplant  surgery  gave 
his  tentative  approval  for  an  operation 
at  no  charge,  if  the  child  could  be 
brought  to  Houston. 

Da  rm  en  to,  a  Merritt  Island  resident 
and  a  physicist  with  the  Air  Force 
Eastern  Test  Range,  relayed  this  infor- 
mation back  to  Italy  and  arrangements 
were  made  for  the  boy's  trip  to  the 
United  States*  Concerned  Italians  do- 
nated nearly  S6,000  so  the  boy  could 
receive  another  chance  at  life.  Finally, 
during  early  July  little  I'abio  Piampiani 
made  the  trip  from  Rome  to  New  York 
and  on  to  Houston,  W4SXX  enlisted 
the    aid    of    three    New    York    hams 


HAMS  CITE 

IN  CONGRESSIONAL  RECORD 

Washington,  D  'C  'The  Honorable 
Emilio  Daddario,  Connecticut  ap- 
pointee to  the  house  of  representatives, 
pointed  to  the  service  of  U.S.  radio 
amateurs  during  a  meeting  of  the  house 
in  September.  I-roin  the  Congressional 
Record  c  nines  the  accoimt  of 
Daddario*s  speech,  which  said  in  part:  . 

,  J  rise  today  to  call  attention  of  the 
House  to  the  valuable  services  per- 
formed by  amateur  radio  operators  - 
'*hams"  as  they  are  frequently  cat  led. 
Operating  their  own  private  radio  sta- 
tions, hams  render  emergency  assist- 
ance in  providing  communications 
during  disasters  such  as  Hurricane 
Ceiia.  We  have  all  read  accounts  of 
such  activities  and  are  weii  aware  of 
the  irivaluabJe  help  these  volunteers 
provide.  What  is  not  so  well  |cnown  is 
the  continuing  assistance  hams  provide 
in  alleviating  a  most  human  problem  — 
the  loneliness  and  suffering  that  comes 
from  the  separation  and  lack  of  com- 
munications between  our  servicemen 
and  their  families.  Those  of  us  who 
daily  see  our  wives,  children,  and  close 
friends  forget  that  there  are  hundreds 
of  thousands  of  young  people  whose 
contact  with  their  families  is  limited  to 
letters  and  occasional  photographs. 
Like  the  concerned  public  servants 
they  are,  hams  have  stepped  forward  to' 
lend  their  aid  and  provide  radio  com- 
munications facilities  so  thai  service- 
men abroad  can  talk  to  their  loved 
ones  at   home.    Using  '* phone  patch'' 


CNER  2000  ATTEND  ARRL 
NATIONAL  IN  BOSTON 


by  W2NSD 


The  Boston  ARRL  National  Con- 
vention was  an  unqualified  success  this 
year  with  well  over  2000  amateurs  and 
their  families  in  attendance,  setting  a 
record  for  ARRL  National  Con- 
ventions in  recent  years. 

The  sad  part  was  the  tiny  display 
area,  a  far  cry  from  a  few  years  back 
when  most  of  the  manufacturers  in  our 
hobby  supported  these  National  Con- 
ventions. Outside  of  a  few  distributors, 
the  main  displays  were  by  Drake, 
Mosley  (Carl  himself  was  ttiere,  by 
gosh!),  Cushcrafl  (Les  Cushman  was 
there!),  National,  Swan,  Signal  One, 
etc.,  plus  a  few  newcomers  such  as 
Ten-Tec,  Eiirhorn,  Lee,  etc.  Even  the 
most  avid  scrounger  of  data  was  hard 
put  to  spend  more  than  a  few  minutes 
in  the  exhibit  area* 

As  outlined  last  month,  pressure 
from  HQ  prevented  the  convention 
committee  from  permitting  any  73 
personnel  from  participating  in  any 
way  in  the  programs.  Fortunately  73 
was  able  to  get  a  small  auditorium 
room  for  one  of  the  convention  days 
and  hold  several  FM  forums,  meetings 
and  discussion  groups,  show  slides 
of  Jordan,  discuss  incentive  licensing, 
and  keep  conventioneers  from  starvnig 
to  death  with  good  New  Hampshire 
freshly  squeezed  cider  and  homemade 
donuts.  Many  thanks  were  received 
for  the  feed  from  convention  goers 
with  either  stunned  pockcthoLvks  or 
stunned  taste  buds  from  eating  at 
the   local   restaurants. 


The  proliferation  of  local  hamfests 
and  conventions  has  put  a  strain  on  the 
larger  manufacturers,  but  perhaps  they 
should  make  every  effort  to  save 
enough  lime  and  money  to  support  a 
national  convention,  for  without  their 
support  a  convention  looks  more  like  a 
smalMown  picnic  and  is  disappointing 
to  amateurs  who^have  come  from  afar 
for  the  expected  gala  affair. 


(K2JS0,  W2I0M,  and  WB2CBP)  to 
assist  the  boy's  mother  in  finding  the 
right  plance  from  JFK  airport  to 
Houston. 

Sorrowfully  the  child  died  on  the 
operating  table  July  12,  But  at  least 
the  boy  had  a  chance  at  life  he 
wouldn't  have  had  if  it  weren't  for  ham 
radio. 

In  an  editorial  entitled  Humani- 
tarian Ham,  the  newspaper  Cocoa  To- 
day said,  **We  think  this  is  a  fine 
example  of  man's  luimanity  to  man.*' 

For  his  pivotal  role  in  this  out- 
standing example  of  the  good  in  our 
Jiobby,  Florida  Skip  last  month  saluted 
Josef  Darmento  as  "Ham  of  the 
Month," 


Lele  Defiiippis  (HB9AMY),  at  right, 
poses  with  two  others  of  his  recent 
all-band  DXpedition  to  Liechtenstein. 
QSLs  are  to  be  mailed  to  HB9AMY 
Box  768,  Lugano  1,  Switzerland. 


equipment  coupled  directly  to  their 
own  radio  receivers  and  transmitters, 
hams  call  friends  and  parents  of  ser- 
vicemen on  the  telephones  and  let 
then]  talk  to  their  absent  soldier  in 
Vietnam  who  use  military  radio  facili' 
ties  over  there.  Acting  as  the  vital  link, 
the  ham  provides  a  much  needed  human 
contact  between  individuals  separated 
by  the  war. 


RADIO  AMATEURS 

"FILL  IN"  FOR 
LOST  LANDLIIMES 

Cuba,  NY- When  a  work  crew  acci- 
dentally cut  through  an  underground 
telephone  cable  recently^  tlie  local  civil 
defense  group  was  alerted  immediately, 
bringing  to  life  an  organized  commun- 
ications network  revolving  around  a  2 
meter  I  M  repealer. 


Gailerd  Perkins 
stations,    working 

Chaos  repeater 
deployed  at  key 
what    the    Ocean 


According     to 
(WB21DQ),    eleven 
through     the     Mt, 
(WA2UWT).    were 
positions    to    plug 
I  imcs  Herald  referred  to  as  the  ''tele- 
phone gap." 

Volunteers  manning  mobile  radios 
supplied  through  the  CD  office's 
RACES  network  -  and  some  CB*ers  — 
patched  together  an  emergency  net- 
work by  which  tlie  Cuba  Memorial 
Hospital  and  the  fire,  police,  and  am- 
bulance services  of  the  community 
could  maintain  instant  contact. 

A  local  CD  official  said  that  no  real 
emergency  arose  during  the  phone  out- 
age, but  the  network  was  ready  and 
operative  '*jus.   ^    ^  e/' 


Page  Two 


*™ 


Swiss  Government 
Okays  FM  Repeaters 


Switzerland,  The  Swiss  Government  has 
given  the  go-ahead  to  amateurs  who 
want  to  put  up  repeaters  on  the  2 
meter  and  450  MHz  amateur  bands. 
Due  to  the  narrow  operating  spectrum 
in  the  2  meter  band  only  the  input  or 
output  of  a  repeater  can  be  placed  in 
that  band:  the  other  end  of  the  repeater 
system  must  be  placed  in  the  450  MHz 
region. 

Swiss  amateurs  are  expected  to  set 
up  their  repeaters  with  inputs  on  the  2 
meter  band  where  they  can  make  most 
effective  use  of  mobile  range. 


MAHS  Ops  iKik 
UHF  DX  Renri 

U.  S.  Hq.,  Ft.  McPherson,  Ga.-  Bill 
Byrd  (WA4HGN)  of  Muscle  Shoals, 
Ala.,  and  Paul  Wilson  (W4HHK),  of 
Collierville,  Tenn.,  set  out  to  break  the 
UHF  DX  record,  and  break  the  world 
record  they  did! 

Bill  and  Paul  are  both  amateur  radio 
operators,  and  members  of  the  Third 
U-  S-  Army  Military  Affiliate  Radio 
System  (MARS),  as  AD4HGN  and 
A4HHKj  respectively.  Both  are  inveter- 
ate experimenters,  anxious  to  advance 
the  ''state  of  the  art"  in  their  avocation 


INTERNATIONAL  NEWS 


From  lARU  Region  1  News:  "AROUND  THE  REGIONS" 


AUSTRALIA: 

The  Wireless  Institute  of  Australia 
has  secured  permission  for  the  use  of 
slow-scan  television  on  all  amateur 
bands  as  authorized  in  Australia.  The 
bandwidth  of  emissions  shall  not  ex- 
ceed that  of  an  A3  signal.  Identifica- 
tion is  to  be  by  call  sign  in  visual  form 
on  the  televised  picture  and  by  tele- 
graphy on  the  telephony  sound  chan- 
neL 

BULGARIA: 

The  7th  National  Convention  of  the 
Central  Radio  Club  of  Bulgaria  was 
held  on  26  April .1970  in  Sofia.  Dele- 
gates from  amateur  clubs  approved  the 
methods  of  development  of  amateur 
radio  in  Bulgaria.  The  convention  cal- 
led for  further  development  of  SSB 
telephony  and  VHF/LIHF  amateur 
communications  in  this  country. 

DENMARK: 

The  following  information  con- 
cerning reciprocal  licensing  has  been 
submitted  by  the  Danish  Posts  and 
Telegraphs. 

The  Danish  General  Directorate  of 
Posts  and  Telegraphs  is  prepared  to 
consider  applications  from  aliens  pro- 
vided that  they  will  stay  in  Denmark 
for  a  reasonable  period  of  time  and 
provided  that  they  have  a  certain  firm 
connection  with  Denmark. 


case  whether  a  license  will  be  granted 
or  not.  If  a  license  for  operation  in 
Denmark  is  granted,  this  will  be  done 
without  a  renewed  technical  examina- 
tion and  code  test 

GERMANY: 

The  Distrikt  Njedersachsen  has 
plans  to  establish  another  training 
course  in  Wolfsburg  which  is  supposed 
to  take  place  during  the  Easter  holidays 
of  1971.  Talks  with  the  management  of 
the  Wolfsburg  Youth  Hostel  have  al- 
ready been  opened  and  it  is  most  likely 
that  the  course  will  materialize. 

The  training  will  include  lectures  on 
techniques,  laws,  and  regulations  for 
amateur  radio,  and  training  in  Morse 
code, 

GHANA: 

The  latest  edition  of  *^9GI  News" 
reports  the  tenth  anniversary  of  the 
inauguration  of  the  Ghana  Amateur 
Radio  Society.  The  number  of  licensed 
amateurs  in  Ghana  is  now  shown  as  40, 

MALTA: 

The  Malta  Amateur  Radio  Society 
has  obtained  the  use  of  a  historic 
building,  known  as  the  Zabbar  Gate, 
for  use  as  its  headquaxters.  The  build- 
ing originally  formed  part  of  the  forti- 
fications erected  by  the  Crusaders*  The 


NIGERIA: 

NARS  reports  considerable  interest 
in  amateur  radio  at  the  Kaduna  Poly- 
technic from  where  a  station  is  active 
under  the  call  5N2KPT.  The  licensee  of 
5N2KPT  is  David  Wilcox,  G2FKS.  It  is 
hoped  that  arrangements  can  be  made 
to  acquire,  without  payment  of  cus- 
toms dues,  equipment  suitable  to  start 
a  club  station.  Certainly  it  seems  right 
that  an  educational  institution  should 
be  able  to  obtain  a  concession  from  the 
authorities. 

SWITZERLAND! 

In  Switzerland  there  were  917  ama- 
teur licenses  in  force  at  the  end  of 
1969.  Membership  of  USKA  at  the 
same  date  totaled  790  full  members 
and  655  associates* 

The  regulations  governing  amateur 
radio  have  undergone  some  slight 
modifications  in  1969,  The  minimum 
age  for  obtaining  a  license  was  lowered 
from  17  to  15  years.  Operation  of 
repeater  stations  is  allowed  on  450MHz 
and  2m. 

USA: 

The  Foundation  for  Amateur  Radio 

Inc.,  a  nonprofit  institution  devoted 
to  advancing  the  interests  of  ama- 
teur radio  with  its  headquarters  in 
Washington,  D,  C-,  announces  the  esta- 


CLASSIFIED 


^ViiJTi 


t^  ty^9*x?  Jy V<>  iy* 


Caveat  Emptor? 


r/5^iAi^5Hn^^j#>^ 


Price  —  $2  per  25  wi*ifds  for  non- 
-com m«*tcial  adsi  SIO  per  25  words  for 
business  venture.  No  display  ads  or  agency 
discount,  Include  your  cheek  with  order. 
Deadline  for  ads  is  the  Ist  of  tht*  month 
two  months  prior  to  pubii cation.  For  ex- 
niaple:  January  tsl  is  the  deadline  for  the 
March  issue  which  will  bt-  mailed  on  the 
10th  of  February,  Type  copy.  Phrase  and 
punctuate  exactly  as  you  wish  It  to  apptNir. 
No  all-capital  ads*  We  will  be  the  iua^e  of 
suitability  of  ads.  Our  responstbnitv  fnr 
errors  extends  only  to  printing  a  corrt-cL  ad 
in  a  later  issue.  For  $1  extra  we  can 
mainiain  a  reply  box  for  you.  We  cannot 
cheek  into  each  advertiser,  so  Caveat  Emp- 
tor. .  . 


DIGIT  ONE  CONTROL  DEVICES: 
Decodt^rs,  cncoderi;.  li^gic  processors, 
autopatch,  power  supply.  Compact* 
plug'in  solid-state  modules,  Applica 
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Box  Ta-ST,  Bellbrook,  OH  45505. 

ROCll ESTER »  N.  Y,  will  again  be 
headquarters  for  the  huge  W,  N.  Y, 
Ham f est,  V.  H.  F.  Conference  and  Flea 

Market,  May  15,  197K 

CLEGG  VENUS  6M  SSB  TRAN- 
SCEIVER, miit<!hini>  AC  416  suiiply, 
speaker i  excellent,  $250.  Ai5io  NC-1)8, 
matching  speaker;  good^  $55.  KlEOP, 
1234  Ridgebrook  Ct,  S,  E.,  Grand 
Rapids  Ml  49  5  08.  Tel.  (616) 
455-1594. 

FOR   SALE   OR   TRADE:   Frequenele 

Meters  BC221  ;  T.Sl 74;  78323.  All  with 
Powersupply  and  Modulation.  Lamp- 
kin  20  5  A  be  via  Li  on  Meter,  Make  offer 
for  rash  or  trade  for  GriddiposciUator; 
Distortion  Analy/er,  RF  Volt  meter  or 
what  have  you,  KGIDD  Walter  Tille- 
man,  351  Furr  Drive,  San  Antonio  TX 
78201, 


EED  HOT  J  5RK  Delta  Tri-bander  — 
Sensational  breakthrough  in  Delta 
Loop  design.  Proven  outstanding  DX 
ant*  Highest  quality;  also  heavy  duty 
high  performance  quads.  Check  our 
low  prices.  Island  Electronics  4102 
Ave.  S.,  Galveston,  Texas  77550. 

NOVICE  CRYSTALS:  40-1 5M  — 
$l.:m:  80M  —  S1.B3.  Free  flyer.  Nat 
Stinnelte  Electronics,  Umatilla  FL 
32784. 


FABULOUS  OLD  TIME  RADIO  SHOWS 

on  tape.  Drama,  comedy,  mystery. 
Catalog  $1.00  (refundable  with  order), 
RADIO  RERUNS,  P.O.Box  724,  Dept, 
73,  RtHlmond,  Wash,  98052. 

2M  FM  -  GALAXY  FM-210.  Complete 
with  power  booster  for  mobile  or 
115V  operation.  Used  for  73  tests 
only,  $200.  less  crystals,  Wayne  Green, 
73  Magazine. 

FABULOUS  CONDITION!  SB 301  Re- 
ceiver with  400  Cycle  CW  Filter,  $265; 
DX60A  Transmitter  and  HGIOB  VFO, 
$70.  Jan  WB6VRN,  1201  Grand  Vista, 
Monterey  Park  CA  91754. 

SALE:  Super  Pro  600  for  Rack  Mount, 
J.  Modeste  WA2LGJ.  615  Casanova  St. 
Apt,  1,  Bronx  NY  10459.  Tel;  (212) 
329-0147. 

SR-2000  AND  AC  SUPPLY,  realigned 
by  Isi,  will  ship  purchaser's  expense, 
best  reasonable  offer.  J,  Richeson, 
Yolo  High  School,  Rt.  1  Box  1900, 
West  Sacramento  CA  95691. 

15  JOHN  F,  RIDER  PERPETUAL 
TROUBLE  SHOOTER  MANUAL  for 
sale  ^  $35t)  —  or  would  trade  for 
Swan-270-OR-Heath-lOl  —  OR  sim. 
Trnscvr.  L  S.  Olson  (WnGagb)  Box  337, 
Mendocini  CA  95460, 

THE  20th  ANNIVERSARY  DAYTON 
HAMVENTION  will  be  held  on  April 
24,  1971  at  Wampler's  Dayton  Harra 
Arena,  Technical  sessions,  exhibits, 
hidden  transmitter  hunt  and  an  inter- 
esting program  for  the  XYL.  For  infor- 
mation write  Dayton  Hamvention, 
Dipt.  7,  Box  44,  Dayton  OH  45401. 

SELL  APACHE  XMTR  with  SB-IO 
Adaptor,  $100,  Also  Drake  2B  w/Xtal 
cahbrator  &  spkr,  $180,  Paul  Reuter, 
W-9-Rov,  Robinson  IL  62454.  Tel. 
(618)  644-2234. 


EDITORIAL 


THE  NAURU  CURSE 


by  Dan  Whit  sett  W4BRE 


Of  the  300  or  so  countries  I  have 
worked  the  past  four  years,  two  or 
three  stand  out  as  being  unusually 
exciting  contactti.  These  stand  out  not 
necessarily  because  they  were  tlie  most 
rare,  but  because  of  the  etTort  I  had  to 
put  out  to  get  them  -  or  maybe  tho 
unusual  manner  in  which  they  were 
worked.  Just  recently  1  made  what  luis 
to  be  one  of  my  two  most  exciting  DX 
contacts.  Nauru  is  certainly  not  the 
rarest  catch  on  the  band,  but  for  some 
reason  it  liad  eluded  nic  througliout 
my  DX  chasing.  I  had  seen  in  the 
various  DX  columns  and  magazines 
where  the  fellers  were  occasionally 
working  Nauru,  but  never  once  did  I 
hear  him.  1  he  main  reason  was  perliaps 
that  his  operating  hours  would  have 
meant  for  me  to  be  on  between  1—4 
a.ni,,  and  I  felt  confident  that  someday 
I  would  tlnd  hfm  on  during  my  regular 
hours.  The  montlis  went  by  and  still  no 
Nauru.  The  call  changed  from  VK9  to 
C21,  and  I  continued  to  look  for  him. 
Then  my  confidence  began  to  fade,  as  I 
began  to  read  that  the  only  operator 
there,  C21JW,  would  be  closing  down 
for  good  verv  soon. 

Then  I  saw  in  Gus'  "DX'er"  that 
the  iiiiddle  of  June  was  the  deadline,  I 
had  one  week  to  find  and  work 
C2UW  -  a  station  that  I  had  iiol  been 
able  to  find  for  27  months. 

So,  with  seven  days  in  which  to  get 
the  job  done,  I  set  my  alarm  clock  the 
first  night  for  1  a,m-  Listening  until  4 
a.m.,  I  didn*t  hear  anything  of  C21J\V, 


WA6FYC,  one  of  the  guys  I  had  asked 
for  assistance  on  the  first  night  of  this 
"mission  impossible,*'  He  told  me  that 
C21JW  was  on  14 J 28,  and  that  he 
would  try  to  break  them,  and  hold  him 
for  nie.  I  leaped  out  of  the  bed,  and 
like  Jim  Ryan  setting  the  world's 
record  four-mil er,  I  dashed  into  the 
ham  room^  turning  on  every  switch 
I  could  find. 

Just  knowing  that  he  was  on  the 
air,  and  that  I  knew  what  frequency 
was  more  than  I  could  handle  and  stitl 
keep  cook 

Just  as  the  receiver  warmed  up,  I 
heard  \VA6rYC  on  CW  on  14.128. 
Then  some  Australian  came  back  to 
him  and  said,  *^Sorry  OM,  but  C2UW 
just  ORT'd,  and  ORT'd  for  good,  since 
he's  packing  up  to  leave  Nauru*" 

There  i$  no  way  in  the  world  1  can 
explain  my  feelings  upon  hearing  those 
words  . ,  ,but  I  believe  every  true  DXcr 
w^ill  know  the  emotions  I  felt. 

Rut  then,  1  heard  a  "break,"  and  a 
voice  said,  "This  is  C21JW,  Vm  stiU 
listening."  Oh  Happy  Day!  My  lieart 
almost  leaped  out  of  my  chest  Even 
though  he  stood  by  for  WA6FYC  1 
started  pounding  tlic  kcyer,  "C21JW 
DE  W4BRE  PSli  PSE  PSH  K." 

lie  came  back,  he  came  back 
. .  J've  got  him!  Oh  hang  on  . .  ,don*t 
have  a  heart  attack  yet . ,  .please  hang 
on  until  we  exchange  reports. 

He  turned  it  to  me,  I  gave  him  a 
report  and  I  was  in  the  process  of 
asking   him   to   listen   for   me   in   the 


of  radio  communications.  They  have 
conducted  endless  experiments;  de- 
signed, built,  and  modiricd  equipment, 
much  of  it  furnished  by  MARS;  and 
tried  new  techniques  in  preparation  lor 
their  record-breaking  communications 
feat  on  2300  MHz  this  summer.  Bill, 
father  of  three,  works  for  the  Tennes- 
see Valley  Authority  as  an  instructor 
of  student  generator  plant  operators. 
Paul,  also  married  and  the  father  of 
two,  is  a  television  broadcast  engineer 
for  a  station  in  Memphis,  Tenn, 

On  July  9>  Bill  drove  a  panel  truck 
to  a  place  called  Sunset  Rock  near  Bon 
Air,  Tcnn.  Inside  the  truck  was  seem- 
ingly enough  exotic  radio  equipnienl 
to  monitor  a  space  flight,  and  on  a 
trailer  behind,  looking  not  unlike  a 
large  mechanical  turtle,  was  a  specially 
tuned  and  rigged  10-ft.  dish  antenna* 

Working  from  an  elevation  of  nearly 
2000  ft.  above  sea-level,  and  using  an 
astrocompass  to  point  his  dish  antenna 
in  precisely  the  right  direction.  Bill 
first  attempted  to  contact  Paul  on  the 
morning  of  July  10,  Repeated  attempts 
that  flrst  day  were  unsuccessful,  but 
early  on  July  1 1  another  call  brought 
the  looked-for  response:  **This  is 
W4HHK  reading  you  loud  and  cleari" 

The  record  thus  established  was  for 
249  statute  miles,  as  established  by 
aeronautical  charts.  And  the  record  is 
now  official,  having  been  recognized 
early  in  September  tiiis  year  by  the 
American  Radio  Rchy  League. 

To  the  uninitiated,  the  distance  may 
not  seem  very  astounding  in  this  age  of 
moon  voyages  and  globe-girdling  com- 
munications. But  the  record  set  by 
Byrd  and  Wilson  was  at  a  frequency  of 
2.3  GHz  -  approximately  four  times  as 
high  as  that  of  the  higliust-frequency 
UHl'  TV  stations  on  the  air  in  must 
parts  of  the  United  States. 

At  that  frequency,  and  even  at 
those    as   much    as   75    times   lower. 


Aliens  have  to  adopt  the  usual 
procedure  when  applying  for  an  ama- 
teur license  (submit  an  application  to 
the  general  directorate).  It  will  always 
depend  on  a  decision  in  each  individual 


members  of  MARS  plan  to  restore  the 
building  and  undertake  conversion 
work,  A  picture  of  the  Zabbar  Gate 
with  members  of  MARS  appeared  re- 
cently in  the  "Malta  Times.' 


communication  is  normally  limited  to 
iine-of-sight,  or  the  horizon.  And  249 
miles  is  more  than  160  miles  beyond 
the  horizon  in  the  location  used  by  Bill 
and  PauL 

Also,  there\s  the  matter  of  power- 
Commercial  UHF  TV  stations  routine- 
ly use  more  than  a  milhon  watts  of 
power  to  send  an  acceptable  signal  50 
miles  or  less.  Bill  and  Paul  communi- 
cated over  their  record-breaking  dis- 
tance using  less  than  1  kW,  the  legal 
limit. 

It  all  Lidds  up  to  a  most  impressive 
achievcmenl,  especially  when  one  re- 
members that  it  was  accomplished  by 

two  amateurs  using  mostly  home-built 
or  modified  surplus  equipment.  If  the 
two  southern  gentlemen  who  accom- 
plished it  will  excuse  the  expression, 
their  feat  stands  as  a  notable  example 
of  modern  yankee  ingenuity. 


/  y^ 


1 


^......nient  by  it  of  a  Hospitality  Com- 
mittee with  the  objective  of  providing 
visiting  foreign  licensed  radio  amateurs 
with  an  opportunity  to  meet  some  of 
our  local  active  hams  and  if  desired 
visit  a  local  amateur  station. 


PauJ  M.   Wilson  of  CoUierville,   Tenn, 

stands  beside  the  antenna  used  in  bis 
radio  nnoon  bounce  experiment.  Wilson 
is  a  member  of  the  Third  US  Army 
Military  Affiliate  Radio  System  which 
provided  most  of  the  parts  he  modified 
in  order  to  build  his  imposing  radio 
station. 


(L^R)  A4HHK  and  AD4HGN,  Opera- 
ting  as  W4HHK  and  WA4HGN  on  the 
amateur  2300  MHz  Band^  set  a  new 
tropo-scatter  distance  record  on  11 
July  1970f  when  a  two-way  contact 
was  made  between  Bon  Air,  Tenn.  and 
Collierville,  Tenn.f  a  distance  of  249 
statute  miles. 


WAR,  NSS.  NPG,and  AIR  had  a 
combined  total  of  8,208  QSOs  during 
the  twelve  hours  and  forty-five  minutes 
devoted     to     the    military-to*amateur 

crossband  portion  of  the  communica- 
tion tests.  Included  in  this  total  were 
197  air /ground  QSOs  made  by  Navy 
aircraft  on  the  east  and  west  coast. 
Conirnemorativc  QSL  cards  have  been 
mailed  to  all  contacts  that  could  be 
identified.  Any  amateur  who  has  not 
received  a  QSL  card  confirming  his 
contact  should  address  a  request  for 
confirmation  to  the  appropriate  sta- 
tion, or  Armed  1  orces  Day  Contest, 
A  iten  tion:  Headquarters,  U^S.Air 
Force,  !MUX)M.  Room  5B53t,  The 
Pentagon,  Washington,  D,  C-  20310. 
This  request  must  include  the  ama- 
teur's call  sign,  the  station  worked, 
time  of  contact,  and  the  frequency 
utilized  by  the  military  station. 


73  GOES  TO  VIEW  AM 

The  43  MARS  stations  in  Vietnam  and 
Thailand  are  ijII  getting  copies  of  73 
now  on  a  gratis  basis  through  the 
efforts  of  Alex  Scherer  A9EU  of 
Ottawa,  Hiinois.  It  is  hoped  that  this 
amateur  radio  magazine  will  interest 
liic  uKiny  operators  at  these  remote 
stations  in  getting  on  the  ham  bands 
and  in  pursuing  amateur  radio  when 
theV  return  to  the  U,S» 


Page  Three 


MERRY  XMAS  AND  HAPPY  NEW 
YEAR  from  WOCVU,  lowa*s  most 
truthful  station.  Generally  on  20  meter 
SSB.  Collins  KWS-1  and  75A'4.  Telrex 
Optimum  spaced  beams,  U'OCVU, 
Chas.  W,  BoegeU  Jr.,  1  500  Center  Point 
Road  N,  E.,  Cedar  Rapids  I  A, 

TR4  &  AC3  just  factory  checked  and 
alined.  First  Certified  check  for  $450 
winner.  David  Beckwith,  W2Qm,M, 
Box  226,  Pompton  Lakes  NJ  07442. 

TECH     MANUALS     —     R'390/URR, 

R-390A/URR,  TS-1H6D/UP,  BC-639A. 
R-274/FRR,  OS<aC/U,  $6.50  each; 
R-274/FRR,  08^C/U,  $6.50  each: 
TS-174/U,  TS-175/U,  TS-323/UR. 
$5,50  each.  Hundreds  more.  S.  Con- 
salvo,  4905  Roanne  Drive,  Washington 
DC  20021. 

HA-460  AND  TR-lOB,  both  hghtly 
used,  $75  each,  ppd.  D.i^dd  Welty,  320 
N.  Blackstone,  Tukre  CA. 

HAM-M  ROTOR  AND  CONTROL* 

$94.95.  Ideal  Christmas  gift  for  Dad, 
RG8U  foam  coax  $A0  a  foot  FOB. 
Monte  Southward,  WB8GZQ,  Rl, 
Upper  Sandusky  OH  43351. 

BUY,  TRADE*  SELL  USED  RE- 
CEIVERS* or  trade  for  new  general 
merchandise.  Available  HQ-200,  51S-1 
SX-122  and  BC-799B.  1 0-day  money- 
back  guarantee.  30-day  warranty  on 
parts  and  labor.  Steven  Kullmer,  Ever- 
green Hatchery,  Dysart,  Iowa  51114, 

FOR  SALE  EICO  7  20  xmtr  —  $45.00; 

Johnson  6N2  xmlr  —  $45.00;  HA-1 
Kever  w/VIBRO  Keyer  — 
$65.00 ;ARC-b  rcvr  w/ll5  VAC  p.  s.  — 
$20.00;  Novice  Xtals  -  $,75;  Regency 
GT-523  mobile  CO*  xcvrs  —  $35.00 
each;  EICO  221  VTVM  —  $20,00i 
AC-1  QRP  xmfcr  -  $20.00;  P-2  SWR 
meter  —  $15.00.  Need  cash  for  gradu- 
ate school.  Will  ship  collect,  R.  O. 
Lust,  WB9DWG,  320-4  North  Tratt  St„ 
Whitewater,  Wl  5  3190, 

TOLEDO  MOBILE  RADIO  ASSOCIA- 
TION'S 16th  ANNUAL  HAMFEST 
AND  AUCTION  will  be  held  February 
21,  1971,  Lucas  County  Recreation 
Center,  Maumee,  Ohio.  $1.00  registra- 
tion. Open  table  sales.  Map  and  info 
write:  TMRA  W8HHF,  Box  273, 
Toledo,  Ohio  4 3 GDI. 

GREENE  Center  dipolc  Insulator,  with 
..,  or  ...  without  balun.  See  Nov^ember 
issue  73,  page  107. 


SAROC,  January  7-10,  1971,  Flamingo 
Hotel  Convention  Center,  Las  Vegas, 
Nevada.  Sponsored  by  Southern 
Nevada  .'\RC,  Inc,  Box  7  3,  Boulder 
City,  Nevada.  Advance  registration 
+14,50  per  person  accepted  until  Jan- 
uary 4,  regular  registration  at  door, 
includes  Flamingo  Hotel  Late  Show 
and  drinks,  Sunday  breakfast,  Cocktail 
parties,  technical  seminars  and  meet- 
ings, ARRL,  DX,  FM,  MARS,  QCWA, 
WCARS-7255,  WPSS-3952  and 
WSSBA.  Ladies  program.  Flamingo 
Hotel  SAROC  room  rate  $12.00  plus 
room  lax,  per  nigh  I,  single  or  double 
occupancy  January  3  through  12»  1971. 
Mail  accomodations  request  to  Fla- 
mingo Hotel.  Mail  advance  registration 
to  SAROC,  W7PRM,  Club  president. 
W7PBV,  SAROC  Convention  cliair- 
man, 

DRAGON  FLY  .„  antenna,  for 
20-40-75  meters  ...  no  traps  ,,.  no 
compromise  •..  eight  months  in  devel- 
opment ...  one  feed  line  ..•  SWR  one  to 

one  guaranteed.  Construction  drawings 
$5.00.   Box   423,  Wakefield  RI  02880. 

FOR  SALE:  Heathkit  HW  32,  $85.00; 

mint  condition.  M.  Kaufman,  36  Har- 
vard Ave.,  Brook  line  MA  02146. 

MSI-DTL  INTEGRATED  CIRCUITS: 
Guaranteed  new  —  gates  $,56,  F/F 
$.72,  dual  F/F  $.92,  MSI  $2.00,  dual 
Lamp  drivers  $1*60,  Other  inexpensive 
parts,  Mitch^Lan  Electronics  Co.,  Dept, 
7370,  P.  O,  Box  4822,  Panorama  City 
CA  91412. 

CAPACITORS.  100  MFD  at  3  kv. 
Aerovox  or  Sprague,  6"  x  8*'  x  14", 
Single  terminal  welded  steel  cans.  2  for 
$35,00,  FOB.  W5DAU.  Box  1443, 
Hobbs  NM  88240. 

FOR  SALE  —  MAKE  OFFER:  Gonset 
GSB-100,  SSB  XMTR;  Hammarlund 
HQ-llOC;  Homebrew  800  watt  linear. 
John  McLean,  5603  N*  12th  Ave. 
Phoenix,    AZ    85013 

FM  CRYSTALS  FM-210.  They're  ac- 
curate, by  International,  Transmit:  146 
22,  146.25,  146.28,  146,31,  146,34, 
146.46,  146.76*  146.94.  Receive: 
146.76,  146.88,  146,94,  $5  each, 
singly  or  in  lots,  Wayne  Green,  73 
Magazine. 

WEST  COAST  HAMS  buy  their  gear 
from  .4mrad  Supply  Inc.  Send  for 
flyer.   1025  Harrison  St.^  Oakland  CA 


but  I  did  talk  with  several  Calif ornians 
who  had  worked  him,  1  told  them  of 
my  plight,  and  asked  them  to  call  me  if 
they  should  hear  him. 

The  next  night  when  I  heard  some- 
one mention  his  call,  my  hopes  got  up 
and  I  called  in  ,  .  .but  he  had  just  left  a 
few  minutes  before.  Knowing  he  was 
around  somewhere,  J  frantically 
searched  the  band  that  night,  but 
absolutely  nothing. 

The  fourth  night  my  clock  again 
went  off  at  1  a.m.  Bear  in  mind  that  I 
would  only  have  been  asleep  for  an 
hour  or  so,  and  when  the  clock  would 
go  off,  it  would  scare  me  half  to  death. 
Again  1  found  a  QSO  where  C21JW 
had  just  signed  out  to  go  look  for  a 
friend.  1  searched  the  band  and  found 
his  friend,  but  no  Nauru. 

Again  the  fifth  night .  . , nothing. 
The  sixth  night,  same  story  -  and  1 
was  beginning  to  believe  I  had  the 
Nauru  curse. 

On  the  seven  til  night,  whicli  was 
going  to  be  my  last  try  since  he  was 
due  to  leave  in  a  day  or  so,  and  since 
there  was  no  way  in  the  world  I  could 
survive  this  ordeal  any  longer,  1  tuned 
the  band  for  two  hours ,.  .all  in  vain. 
Finally  giving  up,  admitting  that  the 
Great  White  Father  didn't  have  in  his 
plan  for  W4BRE  to  work  C21J\V,  1 
staggered  off  to  bed, 

T must  have  only  been  in  bed  for  10 
minutes  or  so  when  the  phone  rang, 
scaring   me    out  of  my  wits;  it  was 


phone  band,  when,  forgetting  that  my 
amplifier  was  tuned  up  around  14*275, 
Blam!  FUSES  BLEW!  OH  NO!  I've  lost 
him.  Pve  LOST  NAURU.  WE 
HAVEN'T  YET  EXCHANGED 
REPORTS. 

If  I  thought  1  was  panicked  when 
6FYC  first  phoned  me,  thai  was  nothing 
compared  with  now.  I  WAS  OUT  OF 
MY  MIND.  Well,  I  must  have  set  a 
workPs  speed  record  because  when  1 
got  back  on  the  air  C21JW  was  telling 
me  that  he  couldn't  go  to  the  phone 
band  because  he  had  to  leave.  Good 
enough,  I  was  plenty  happy  just  to  get 
tlic  contact. 

WA6FYC  and  I  moved  up  to  the 
phone  band,  and  1  was  tlianking  him 
.  .  .offering  to  send  him  money,  my 
car,  my  house,  anything  in  appreci- 
ation, and  mopping  the  sweat  off  my 
brow,  trying  to  regain  a  little  com- 
posure, when  "Break,  Break,  this  is 
C21JW/' 

He  had  a  change  in  plans,  didn't 
have  to  leave  just  that  minute,  and 
came  up  and  ragchewed  with  61''YC 
and  me  for  30  minutes! 

What  an  experience  .  *  J  was  dying 
to  tell  the  people  at  the  onicc  and  my 
other  friends  about  it.*. but  no  one 
, .  .absolutely  no  one  but  an  honest- 
to^goodness  true  DXer  could  under- 
stand and  appreciate  this  absolutely 
absurd,  insane,  and  ridiculous  under- 
taking, and  why,  after  it  was  all  over,  I 
would  say  to  myself.,, it  was  well 
worth  it 


SELL  HEATH  DX'60A»  5  crystals. 
Used  very  little  Guaranteed  to  be  in 
good  working  condition.  Make  offer. 
Arris  Sigle,  543  N.  2nd,  Osborne, 
Kansas  6747  3, 


VARIAC,  120  volt  J  20  amp.,  uncased, 
new  $25.00  each  plus  shipping  (25  lbs. 
each).  Brian  Sherrett,  TUSLOGj  Dept. 
6  Box  557,  APO  New  York  09254. 


TFRED  OF  ^^MICKEY  MOUSE'* 
TRANSCEIVERS?  Immaculate 
KWS-1,  75A4  (.800  MHz,  2 A  MHz 
filters)  aU  factory  modifications*  Corn- 
del,  Shore  444,  WiD  demonstrate/ 
guarantee.  Top-notch,  $1,000,  (813) 
646-5349,  nights. 

WANTED:  Heathkit  HA  14  Linear 
Amplifier  with  or  without  tubes, 
HL9KQ  American  Embassy,  APO  San 
Francisco  CA  9S301* 


Page  Four 


Q^e/9^u  ^^r^J^m^J 


Sage,  who  is  celebrating  her  first 
birthday  on  Decennber  31,  my  wife 
Lm,  and  I  at  I  wish  every  one  of  you  a 

very  merry  Christmas.  We're  sitting 
on  one  of  those  Heath  Boonie  Bikes, 
by  the  way,  and  we  have  lots  of  fun 
bouncing  around  the  New  Hampshire 
hills  and  forest  trails  on  them. 


Director  Green? 

Many  readers  ask  why  1  don't  run  for  ARRL 
director  since  I  know  the  organization  so  well 
and  have  proposed  so  many  ways  of  improving  it. 
Frankly,  I  somehow  doubt  tlial  the  executive 
committee  would  waive  the  bylaw  prohibiting 
ham  publishers  from  running  for  director,  even 
though  they  have  tn  the  case  of  ARRL  stalwart 
KONL. 

It  would  be  nice  to  be  able  to  run  for  the  job 
and  I  think  I  could  be  a  considerable  help  in 
bringing  the  League  into  the  1970s  if  1  were 
elected.  What,  you  ask,  would  I  do  as  a  director 
of  the  ARRL  to  improve  that  conservative  old 
institution? 

Better  Directors 

Probably  the  first  thing  I  would  do  would  be 
to  try  to  encourage  amateurs  to  run  for  director 
in  other  divisions  of  the  ARRL  who  are  inter- 
ested in  improving  amateur  radio  to  replace  those 
directors  who  are  there  for  the  prestige  of  the 
office  rather  than  as  true  representatives  of  their 
constituents.  Little  can  be  done  to  improve  the 
League  until  at  least  nine  of  the  16  directors 
want  to  improve  it  Right  now  it  seems  hopeless. 

Sound  Financial  Basis 

There  is  no  excuse  for  the  League  losing 
money  every  year!  There  are  many  ways  to 
increase  income  and  to  cut  expenses.  By  reducing 


10 


the  size  of  QST  by  a  fraction  of  an  inch  so  it 
would  fit  on  modern  web  offset  presses  and  by 
using  more  modem  paper  a  saving  of  thousands 
of  dollars  a  month  can  be  achieved.  There  are 
many  other  areas  where  substantial  savings  can  be 
nrade  without  losing  any  valuable  services.  We 
can  see  that  the  League  investments  are  bringing 
in  a  maximum  return.  We  can  plan  ahead  for 
continued  nonprofit  operation,  but  an  eventual 
end  to  the  tax-free  status. 

Washington  Lobby 

Only  wlien  tlie  ARRL  has  a  registered  lobby 
in  Washington  can  it  truthfully  say  that  it 
represents  amateur  radio.  Such  a  lobby  would 
put  an  end  to  the  double  talk  excuses  from  HQ 
and  would  give  amateur  rndio  the  first  real 
opportunity  to  protect  itself  in  Washington.  A 
monthly  newsletter  to  congress  would  be  invalu- 
able in  laying  the  groundwork  for  a  lobby. 
Amateurs  are  making  news  all  over  the  world,  but 
few  outside  of  our  hobby  hear  about  it.  We  need 
to  beat  our  drum.  It  is  entirely  possible  that 
much  or  all  of  the  cost  of  a  lobby  in  Washington 
could  be  financed  entirely  separate  from  the 
ARRL,  thus  keeping  League  expenses  down. 

Emerging  Nations 

The  key  to  the  future  of  amateur  radio  lies 
entirely  with  the  votes  of  member  nations  of  the 
International  Telecommunications  Union  at 
Geneva.  It  would  behoove  us  to  keep  this  in  mind 
and  devote  some  time  and  energy  towards  pro- 
tecting our  frequencies  internationally-  The  ITU 
is  presently  controlled  by  the  emerging  nations  of 
Africa  and  Asia  and  the  League  could  be  of  great 
help  to  many  of  these  countries  at  little  cost.  It 
could  offer  custom-made  amateur  radio  regula- 
tions for  individual  countries,  complete  with 
amateur  license  exams.  It  could  organize  expedi- 
tions to  these  countries  to  explain  the  value  of 
amateur  radio  to  the  heads  of  the  countries  and 
their  top  officials.  Club  stations  could  be  organ* 
ized  in  the  countries,  probably  in  high  schools.  If 
equipment  is  not  available  it  could  be  arranged  to 
be  donated  by  interested  amateurs  and  manufact- 
urers. Every  effort  should  be  made  to  assure 
amateur  radio  votes  at  the  ITU, 

A  Modern  QST 

The  club  magazine  would  interest  many  more 
amateurs  if  it  were  written  in  a  warmer  and  more 
friendly  tone.  It  would  look  more  like  1970  with 
modern  type  and  better  layout  design.  Readers 
miglii  have  more  confidence  in  the  League  if 
both  sides  of  controversial  problems  were  openly 
discussed  in  QST,  Some  of  the  departments 
which  fill  up  so  much  of  the  space  in  QST  could 
be  shortened  or  eliminated  in  the  interests  of 
bringing  information  of  interest  to  the  most 
readers. 

Directors  Meetings 

The  inability  of  management  to  get  decisions 
from  the  directors  more   than  once  a  year  has 

(conu  on  p.  102) 

73  MAGAZINE 


For  The  Experimenter ! 

International  EX  Crystal  &  EX  Kits 

OSCILLATOR  /  RF  MIXER  /   RF  AMPLIFIER  /   POWER  AMPLIFIER 


Available  from  3,000  KHz  to  60,000  KHz.  Supplied  only  in 
HC  6/U  holder.  Calibration  is  ±.02%  when  operated  in  International 

OX  circuit  or  its  equivalent.  (Specify  frequency) 


^ 


'mL>  V 


ox  OSCILLATOR 

Crystal  controlled  transistor  type. 
Lo  Kit  3.000  to  19,999  KHz         ^ 
Hi  Kit  20.000  to  60.000  KHz       ^ 
(Specify  when  ordering) 


295 


-=^^4^ 


MXX-1  Transistor  RF  Mixer  $3J0 

A  single  tuned  circuit  intended  for  signal  con- 
version  in  the  3  to  170  MHz  range.  Harmonics 
o(  the  OX  oscillator  are  used  for  injection  in 
the  60  to  170  MHz  range. 
Lo  Kit  3  to  20  MHz 
Hi  Kit  20  to  170  MHz 
(Specify  when  ordering) 


SAX'1 


SAX*1  Transistor  RF  Amplifier  $3,50 

A  small  signal  amplifier  to  drive  MXX-1  mixer; 
Single  tuned  input  and  link  output. 
Lo  Kit  3  to  20  MHz 

Hi  Kit  20  to  170  MHz 
(Specify  when  ordering) 

PAX-1  Transistor  RF  Power  Amplifier  $3.75 
A  single  tuned  output  amplifier  designed  to 
follow  the  OX  oscillator.  Outputs  up  to  200  mw 
can  be  obtained  depending  on  the  frequency 
and  voltage.  Amplifier  can  be  amplitude  modu- 
lated for  low  power  communication.  Frequency 
range  3,000  to  30,000  KHz. 

BAX-1  Broadband  Amplifier  $3.75 

General  purpose  unit  which  may  be  used  as  a 
tuned  or  untuned  amplifier  in  RF  and  audio 
applications  20  Hz  to  150  MHz,  Provides  6 
to  30  db  gain.  Ideal  for  SWL,  Experimenter  or 
Amateur. 

Write  tor  comptete  c&tahg. 


INTERNATIONAL 


lO  NO-   LEE 


MFO.   CO.,   tiVJC. 

OKLA    CITY.  OKLA.  73lO? 


Last  Chance  for  SAROC  Flight! 

From  early  indications,  the  upcoming  "fun" 
convention  in  Las  Vegas  (January  1971")  will 
be  the  biggest  success  of  any  ham  conventioii 
ever  held  anywhere  -bar  none.  If  you've  got  a 
vacation  comings  or  if  you  would  just  Uke  to  take 
the  wife  and  get  away  for  a  weekend,  by  aU 
means  attend!  Even  if  your  wife  doesn't  like 
conventions,  sheUl  want  to  go  to  this  one  - 
because  Las  Vegas  is  a  magicland  -  probably  the 
only  place  in  the  world  where  you  routinely 
bump  into  TV  personalities,  movie  stars,  and 
other  famous  personages.  (Last  year  I  poked  Don 
Rickles  with  a  Motorola  telescoping  antenna,) 

If  youVe  planning  a  West  Coast  vacation 
anyway,  here's  your  chance  to  be  really  sneaky. 
You  can  fty  on  one  of  SAROC's  two  chartered 
*'champagne*'  planes  (from  New  York  or 
Chicago)*  stay  a  full  3-njght  weekend  at  the 
Flamingo*  enjoy  a  couple  of  stage  shows,  and 
buddy  it  up  with  hams  from  every  where  -  all  for 
less  than  conventional  airline  rates. 

As  if  that  weren't  enough,  additional  free 
*'flings"  are  being  sponsored  by  public-spirited 
groups  and  organizations.  For  example,  Ham 
Radio  magazine  is  footing  the  bill  for  an  all-you- 
can-drink  cocktail  party  on  Thursday  night;  the 
next  evening,  Sw^an  Electronics  is  picking  up  the 
tab  for  tlie  same  kind  of  arrangement.  And  the 
FM  boys  in  Las  Vegas  are  planning  a  head-busting 
three-night  open  house,  with  free  haidj  soft,  and 
hot  stuff  to  drink. 

The  round-trip  "everything  included"  plane 
fare  from  New  York  is  $229  (from  Chicago,  it's 
$199) J  and  there's  a  full-page  ad  in  this  issue  that 
tells  exactly  all  that  the  price  includes.  But  the  ad 
doesn*t  tell  you  that  SAROC  is  the  Western 
convention,  where  the  accent  is  on  fun  and  the 
emphasis  is  on  ham  radio.  This  January  will  mark 
the  Sixth  Annual  Radio  Operators  Convention 
and  the  fourth  (and  by  far  the  biggest  and  best) 
national  FM  convention. 

With  the  August  FM  lineup  (practically  all  the 
big  names  in  repeaters)  and  the  unprecedented 
current  popularity  of  VHF  FM,  a  turnout  of 
more  than  a  thousand  FM*ers  is  expected-  This, 
coupled  with  the  already  well  established  popu- 
larity of  the  other  aspects  of  SAROC,  should 
make  it  a  convention  to  top  all  others  in  ham 
history. 


If  you^re  going,  better  make  plans  now.  If  you 
don't  reserve  a  seat  on  one  of  the  charter  flights 
before  November  25,  you'll  have  to  get  there 
under  your  own  steam  -  and  that  could  get 
expensive. 

Discrimination.  .  . 

Wayne  Green  used  to  mention  occasionally 
that  the  League  wouldn^t  let  him  speak  at  this 
convention  or  that  —  that  the  League  wouldn't 
let  him  set  up  a  booth  for  73  at  various 
League-sponsored  affairs,  and  other  seemingly 
unfriendly  or  discriminatory  actions  on  the  part 
of  the  ARRL,  To  be  quite  blunt,  I  only  half- 

beheved  him  because  his  charges  all  seemed  to  be 
so  fantastic. 

But  at  the  recent  Boston  convention,  I  found 
out  for  myself.  1  was  invited  to  speak  on 
repeaters,  and  accepted.  But  the  League  said  no.  I 
saw  a  letter  Huntoon  had  written  saying  that  I 
wasn't  fit  to  speak  at  any  League  convention. 

A  few  of  the  fellows  protested  to  the  League, 
even  to  the  extent  of  offering  mild  threats  of 
^'breaking  off  with  ARRL  affiliation.  But 
Robert  York  Chapman,  New  England  Division's 
director,  answered  one  of  the  protestors  with  a 
counterthreat.  It  is  never  too  late,  he  said,  for  the 
League  to  back  out  of  backing  the  convention. 
Clearly,  the  convention  planners  had  to  make  a 
choice  between  the  League  and  the  staff  of  73. 

Working  almost  surreptitiously,  but  closely 
with  the  convention  planners,  73  rented  an 
auditorium  in  the  hotel  where  the  convention 
was  being  staged,  then  held  its  own  programs 
with  its  own  speakers.  And  the  whole  thing  went 
off  extremely  well. 

The  next  convention  was  Tarry  town,  another 
League-sponsored  affair  taking  place  within  the 
Hudson  division-  I  suggested  to  Wayne  that  we 
set  np  a  booth  there. 

"Go  ahead  and  try,"  Wayne  told  me.  ''But  I 
can  teU  you  now  that  they^ll  tell  you  their  booth 
space  has  already  been  sold  out." 

Well,  I  tried  anyway,  1  contacted  Harry 
Dannals,  who  told  me  in  a  very  friendly  and 
congenial  manner  that  there  would  never  be  any 
space  for  73  in  any  convention  that  he  is  involved 
with. 

Now,  fellow  readers,  I  have  just  told  you  the 
truth.  There  is  not  one  ounce  of  exaggeration  in 
the  foregoing-  And  if  Harry  Dannals  is  an  honest 
man,  he  will  certainly  admit  that  what  transpired 
between  us  was  exactly  as  I  have  related - 

1  charge  Harry  Dannals  with  discriminatory 
practices,  and  I  charge  the  ARRL  with  sanction- 
ing such  practices.  I  don*t  want  to  make  an 
enemy  of  Dannals,  because,  quite  frankly,  he  is  a 
personable  and  congenial  fellow.  But  he  must 
learn  that  his  acts  are  not  those  of  a  responsible 
director. 

Those  of  you  in  the  Hudson  division  who 
agree  with  me  could  probably  carry  a  great  deal 
of  weight  if  you^d  drop  Harry  a  line  letting  him 
know  how  you  feeL 

- .  ,K6MVH/1» 


12 


73  MAGAZINE 


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Henry  Radio  has  a  great  antenna  package  program  . . .  big  savings.  Write  for  literature. 


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credit  toward  the  purchase  of  NEW  equipment.  Write  for  bulletin.  Export  inquiries  invited. 


TED  HENRY  (W6U0U) 


BOB  HENRY  (WOARA) 


WALT  HENRY  (W6ZN) 


KmMii 

"Worlds  Largest  Distributor  of  Amateur  Radio  Equipment" 


11240  W.  Olympic  Blvd.,  Los  Angeles, 

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New  York  area:  John  Richardt  W2W1 Y  201/637-4107 

Houston  area:  Jan  Carman  W5SBX  713/464-0419 


1 


M 


Ed.  Note: 

Last  month  (or  the  month  before),  Having  Dave  took  on  the  Technicians  in  the  country,  and  after 
three  rounds  went  down  for  the  count.  This  month,  as  "Dave  the  Brave/'  it's  Conditionals.  Watch  for 
his  subsequent  attacks  on  Novices,  premarital  sex,  Mexican  food,  the  electoral  college,  and  motherhood. 


In  previous  issues  1  have  mentioned  phone 
patches*  usually  Latin-American  in  origin, 
which  have  been  QRM'ing  the  DX  frequencies, 
especially  the  !ow  end  of  the  20  meter  phone 
band,  in  ever  growing  numbers.  The  response  of 
the  readership  has  not  been  particularly 
encouraging;  there  seems  to  be  a  feeling  that 
nothing  can  be  done  about  the  situation 
because^  in  the  words  of  one  of  my  correspon- 
dents, ".  -  .foreign  operations  cannot  be  regula- 
ted or  conliQlled."  While  this  is  partially  true, 
let  me  assure  you  that  it  is  not  completely 
impossible  to  effect 
changes.  There  is  no 
basis  for  the  total 
frustration  which  has 
been  expressed. 

There  are  certain 
actions  which  can  be 
taken  that  may  prove 
to  be  effective;  for 
example,  a  large  per- 
centage of  these 
patches  are  being  run 
by  stations  iri  Florida 
and  Puerto  Rico, 
both  of  which  are 
indeol  subject  to  the 
regulations  of  our 
own  licensing  author- 
ity. The  FCC  -  while 
many  U.S.  hams  may 
consider  it  unsympa* 
thetic  to  the  needs 
and  desires  of  the 
amateur  fraternity  - 
is  quite  responsive  and  sensitive  to  reasonable 
requests,  when  they  are  made  in  a  responsible 
and  constructive  manner.  It  is  far  from  an 
impossibility  to  envision  the  establishment  of  an 
officially  designated  frequency  allocation  which 
would  limit  the  patches  to  sequestered  portions, 
as  is  presently  done  with  RTTY,  thus  going  a 
long  way  toward  eliminating  the  annoyance. 

But  there  is  another  side  to  this  coin.  The 
phone  patch  stations  are  also  entitled  to  a  fair 
measure  of  consideration.  There  is  no  founda- 
tion, either  in  the  regulations  or  by  operating 
precedent,  for  DX'ers  to  feel  that  they  are 
entitled  to  a  preemptive  *iock"  on  those  por- 
tions of  the  bands  which  they  regard  as  desira- 
ble, and  that  they  are  perforce  within  their 
rights  in  bludgeoning  the  opposition  into  sub- 
mission by  their  sheer  weight  of  numbers,  by 
using  power  amplifiers,  extravagant  antenna 
systems,  or  by  any  other  means.  There  is  still  a 
right  and  wrong,  after  all. 

The  problem  is  a  knotty  one.  Both  groups 
have  raised  legitimate  complaints.  Both  have 
valid  grievances.  And  somewhere  along  the  tinef 


accommodations  must  be  found  so  as  to  create 
order  out  of  chaos. 

A  tangential  point  is  being  raised  by  the 
General  class  operators.  Many  DX  stations  seem 
to  restrict  their  listening  frequencies  solely  to 
our  U.S.  Advanced  and  Extra  class  subbands, 
making  it  virtually  impossible  for  the  Generals 
to  compete  for  DX  on  an  equitable  basis.  Of 
course,  it  must  be  acknowledged  that  it  is 
awfully  simple  for  anyone  to  master  the  rela- 
tively elementary  material  covered  in  the  single 
examination  element  which   upgrades  them  to 

the  Advanced  class. 
Anyone  who  is  at  all 
serious  about  work- 
ing DX  would  be 
more  than  willing  to 
devote  a  small  por- 
tion of  his  time 
toward  accomplishing 
this  simple  task. 

The  Conditional 
class  ham,  however, 
is  faced  with  a  genu- 
ine crisis.  He  must 
qualify  in  aU  ele- 
ments, both  CW  and 
theory  .  *  Js  given 
absolutely  no  credit 
for  any  elements  in 
any  of  the  exams 
. .  .hence  must  pass 
the  13  wpm  code 
test  plus  the  General 
and  Advanced  theory 
elements.  Many  of  us 
are  prone  to  forget  that  there  are  vast  numbers 
of  people  who  hold  this  pade.  If  you  will 
examine  the  figures  (they  may  be  found  in 
recent  issues  of  the  callbook),  you  will  learn 
that  of  the  total  ham  population,  more  than 
10%  fall  into  this  category.  There  are  10  states 
in  which  Conditionals  outnumber  Generals!  In  a 
few  of  these  states  the  examination  points  are 
truly  beyond  a  reasonably  convenient  traveling 
radius.  But  in  several  of  the  states  referred  to, 
this  is  not  the  case,  and  I  fear  tJiat  the  Condi- 
tional ticket  has  been  acquired  under  terms 
which  could  not  be  regarded  as  completely 
justified  by  the  circumstances.  The  regulations 
have  been  applied,  in  all  too  many  instances,  to 
circumvent  the  qualifying  requirements,  and 
some  persons  who  could  easily  be  expected  to 
get  to  the  examination  points  have  simply 
exaggerated  the  hardship  angle  of  the  physical 
infirmity  excuse.  1  am  personally  acquainted 
with  several  self-styled  "invalids"  who  eat  like 
horses,  work  like  mules,  and  climb  up  and  over 
ridges    like    mountain    goats    during    the    deer 

fcont  on  p.  104) 


T4 


73  MAGAZINE 


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Name. 


Address- 
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SOLID 


STATE 


Robert  R  Bloom  W6YUY 
8622  Rubio  Avenue 
Sepulveda  CA  91343 


My  original  thoughts  about  under- 
taking a  design  project  of  this  magni* 
lude  were  brought  about  tlirough  a  chal- 
lenge by  W6EGZ,  after  having  just  com- 
pleted a  three-year  design  of  a  solid-state 
receiver.  This  was  early  in  1966.  Based 
upon  the  complexity  of  the  receiver  it  was 
anticipated  that  about  one  year  would  be 
required  to  complete  the  transmitter.  This 
would  mean  using  all  available  evenings  and 
weekends,  abandoning  all  on-the-air  oper- 
ation and  all  other  aspects  of  ham  radio.  As 
with  the  receiver,  it  took  a  similar  three- 
year  period. 

The  big  hangup  in  progress  was  encoun- 
tered in  designing  a  satisfactory  third-mixer 
stage,  free  of  parasitics,  I  tried  many  mixer 
configurations  initially  without  success. 

It  wasn't  until  the  advent  of  a  magical 
*'black  box"  concept  that  appeared  on  the 
industrial  electronic  market,  cloaked  in 
secrecy  and  at  a  price  of  just  under  $200 
that  progress  once  again  was  under  way. 
This  started  a  frantic  search  for  literature 
and  information  as  to  how  this  thing  called 
a  **double-balanced  mixer"  was  operated.  I 
say  ^'magical"  as  this  circuitry  is  so  versa- 


tile that  it  can  be  used  as  a  phase  detector, 
frequency  doubler,  current-controlled 
attenuator,  balanced  modulator,  pulse 
modulator,  phase  detector,  etc.  But  let's 
start  at  the  beginning. 

Were  it  not  for  the  availability  of  all 
commercial  test  equipment  this  project 
would  not  have  been  attempted.  Such 
items  as  a  Hewlett-Packard  counter,  gener- 
ators, and  meters;  Tektronix  oscilloscopes: 
Measurement  Q  meter  and  grid  dip  oscilla- 
tors; temperature-controlled  oven;  sheet- 
metal  cutting  and  bending  equipment:  and 
a  Heliarc  welder  were  some  of  the  items 
used.  For  those  who  wish  to  duplicate  all 
or  part  of  this  system,  all  pert  men  t  dc  and 
signal  voltages  are  called  out  and  all  perti- 
nent coil  data  can  be  found  listed  iji  Table 
L  All  circuits  other  than  the  bulk  elements 
of  the  power  supply  and  the  final  are  of 
modular  construction;  in  today's  teelv 
nology  of  miniature  construction  this  is  the 
easiest  and  neatest,  and  lends  itself  readily 
to  circuit  change. 

The  mdividual  circuits  were  first  bread- 
boarded,  checked  out,  and  then  made  into 
modules  using  single-sided  5/16  in,  copper- 


16 


73  MAGAZINE 


Table  !.  ^ 

Coil  and  Transformer  Data. 

CofI  or 
Trans. 

identify 

Core  Material 

Primary 

Turns 

Secondary 
Turns 

Tap  from 
bottom 

Wire 
type 

Motes 

Transmitter 

Stage 

T 

Ferrox-Cube  cup  core 
tSIIP   AT00-3D3 

SO 
(700/iH) 

16 

Pri.  7/41 
Sec.  15/41 

Unloaded  "Q"  2B0 
Resonant  at  453  VWz 
with  170  pF 

Balanced 
modulator 

Tl 

Ferrox-Cube  cup  core 
I408P   At00~3D3 

70 
(500JUH) 

7 

7/41  Litz. 

''Q"UnL  230 

453  kHz 
LF  ampL 

T2 

Ferrox-Cube  cup  core 
1408P   A-40-4C4 

30 
(40 /iH) 

2           1 

4 

30/44  Litz. 

^'Q"Un  .  T70 

1st  nyixer 
2045  kH; 

13 

Powdered-iron  slug- 
tuned  ceraniic  form 
Vi"  dia  both  coils 

40 

5% 

7/44  Lit£. 

^'Q"Unl.  55 
^'Q*  Loaded  5 

Broad  band, 
2nd  mixer 

T4 

Ferrox-Cube  toroid 
266T-125-4C4 

13 

Tr  if  liar 

13 
26  tota 
wound 

26  solid 
Teflon  cov. 

Sec  tap  is  the  end 
of  one  winding  St 
start  of  another. 

Double- 
balanced 
mixer 

T5 

Ferrox-Cube  toroid 
266T-125-4C4 

9 
Trifilar 

wound 

26  solid 
Tef  ton  cou. 

Pri  tap  is  the  end 
of  one  9-turn  wind- 
ing Si  start  of  other 
9-turn  winding, 

Double- 
balanced 
mixer 

L6 

Powdered-iron  slug- 
tuned  ceramic  'A    dia 

25 

28  solid 
enameled 

Trim  with  8    35  pF 
miniature  trimmer 
8i  fixed  75  pF  silv 
mica  capacitors 

7.0  MHz 
transistor 
rf  ampI 

3/8"  ceramic,  brass, 
slug-tuned 

lOV. 

24  solid 
enameled 

No  trtmmer 

14.0  MHz 

Powdered -iron  sfug- 
tuned  V*"  cerarTiicform 

\VU 

26  solid 
enameled 

Trim  with  8-35  pF 
miniature  trirnmer 

21  MHz 

Powdered- iron  slug- 
tuned  y^"  ceramic  form 

to 

20  solid 
enameled 

No  trimmer 

28.0  MHz 

L7 

Powdered-iron  slug- 
tuned]^'  ceramic  form 

15 

2^/4    & 

9  turns 

26  solid 

enameled 

' 

Band  selec- 
tion osc 
3rd  mixer 

T8 

Ferrox-Cube  cup  core 
t40SP  A-40-4C4 

50 

2 

Pri  32 
Sec  28 

Resonant  with  22 
pF  silver  mica  at 
24.5  MHz 

1st  mixer, 
osci  lator 

T9 

Powdered-iron  slug- 
tuned  3/S'   ceramic 

80 

20 

Pri24 
Sec  9 
&  15 

32  so  id 
enameled 

See  text 

Vfo  output 
transformer 

L10 

Powdered' iron  s  ug- 
tuned  Va"'  ceramic 
form 

25 

28  solid 
enameled 

Trim  with  8-35  pF 
miniature  trtmmer  & 
75  pF  fix.  silv  mica 

1 28  Y7  driver 
plate,  7  MHz 

Brass,  slug -tuned 
3/8"  ceramic  form 

15 

24  solid 
enameled 

Trim  with  7    25  pF 
miniature  trimmer 

12BY7  driver 
plate,  14  MHz 

Brass,  slug-tuned 
3/8''  ceramic  form 

10 

26  so  id 
enameled 

Trim  with  8-35  pF 
miniature  trimmer 

12BY7  driver 
plate,  21  MHz 

Powdered" iron  slug- 
tuned  y*"  ceramic  form 

9 

20  solid 
enameled 

Resonate  with  10 
pF  fixed  silver  mica 

12BY7  driver 
plate,  28  MHz 

L11 

T*  dia  AirDux 
1606T  coil  stock 

15 

3&8 

14  plated 

Tune  with  200  pF 
2kV  split-stator, 
Johnson  200FD20/ 
155-505  C- 11  midget 
air-tuned  300  pF  (Han 
marlund  MC'325-MI 

M  ultiba  nd 

coupler, 

final 

ctad  board,  (Printed  circuits  could  have 
been  used;  however^  the  construction 
about  to  be  described  was  preferred  as  it 
lends  itself  to  change  where  printed  cir- 
cuitry does  not.) 


It  was  first  necessary  to  redraw  the 
schematics,  keeping  all  symbols  to  actual 
size  and  positioned  exactly  as  they  would 
appear  on  the  finished  board  (according  to 
the  overall  block  diagram,  Fig.   1),  A  dot 


DECEMBER    1970 


17 


ICO  vf 


ji — :tr 


ON  injLHSJuir 

SWITCH 

9- f  0'>0 


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♦J3  KH* 


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Figr.  3*  Audio,  balanced  moduiaior,  mechanical 
filter,  i-f  amplifier,  carrier  oscillator,  and  carrier 
buffer  amplifier. 


for  linearity  monitoring  and  testing.  The 
mechanical  filter  is  one  of  the  higher 
quality  Collins  multi-element  3J  kHz 
variety  with  steep  skirts  down  to  90  dB. 
The  input  is  series  tuned  while  the  output 
is  series-parallel  tuned  using  capacitors  in  a 
divider  configuration.  The  loss  introduced 

by  the  filter  is  only  9  dB  and  the  gain  of 
the  following  i-f  amplifier  had  to  be 
severely  limited  by  tapping  the  coil  of  TI 
near  the  bottom  end  and  inserting  degener- 
ation in  the  emitter  of  Q5. 

Overall  gain  measurements  for  this 
board  were  made  using  a  10/1  divider 
scope  probe  connected  at  the  collector  Q4 
of  the  i-f  amplifier.  Using  a  single  tone 
signal  and  no  carrier,  the  50012  pot  in  the 
audio  amplifier  input  circuit  is  set  for  a 
2.5V  p-p  indication  measured  at  the  base 
of  QL  inserting  carrier  to  produce  a  100% 
modulated   sideband  signal,  the  amphtude 


will  increase  to  4-8V  p-p.  Turning  off  the 
carrier  and  switching  to  a  two-tone  audio 
signal  the  indication  will  be  3.8  V  p-p. 

The  next  board,  which  is  located  in  the 
lower  left-hand  corner  on  the  bottom  of 
the  chassis,  contains  the  2045  kHz  first 
mixer  and  2,5  kHz  crystal  oscillator*  The 
major  problem  encountered  with  this  stage 
was  in  designing  a  mixer  transformer,  T2, 
with  a  0  high  enough  to  reject  the  2.5  kHz 
oscillator  signal  from  its  output.  Tills  was 
finally  accomplished  using  the  core 
material  and  data  as  furnished  in  Table  L 

The  L8  kO  series  resistor  from  the  453 
kHz  i-f  to  the  base  of  the  second  mixer  was 
selected  to  limit  the  signal  to  the  mixer. 
With  a  two-tone  signal,  the  mixer  output 
amplitude  at  the  collector  of  Q6  is  1.9V 
p-p,  A  voltage  divider  network  consisting 


Powder  supplies  and  compiete  final  amplifier. 


Vfo    with    lid    removed:    also    shows  selectable 
sideband  crystals  and  balanced  modulator 


20 


73  MAGAZINE 


,1 

1, 

-^H^^ 

Important 

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from  SAMS 


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by  EDWARD  M,  NOix,  W3FQJ.  The  first  com- 
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construction  of  noise  bridges,  line  tuners,  and 
data  on  measuring  resonant  frequency, 
velocity  factor,  and  SWR- 
Order  24006,  only $4.50 

73  Vertical^  Beanii  and  Triangle  Antennas 

by  EDWARD  M.  NOix,  W3FQJ.  Describe  the 

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.enet« 


n  Send  Free  1970  Sams  Book  Catalofl 


Name 

FLLASE  PJtIfiT 

Address. 


L 


Cfty_ 


State. 


^ip. 


Left  —  band  select  switch  and  6146  sockets. 
Middle  —  band  select  crystal  oscillators,  2nd  and 
3rd  mixerSf  and  rf  amplifier.  Right  —  Mike  ampli- 
fier, mechanical  filter,  and  i-f  amplifier.  Back  — 
2.5  MHz  crystal  oscillator  and  1st  mixer;  two- 
tone  oscillator. 


of  a  220  and  a  150X1  resistor  shunts  the 
secondary  of  T2,  setting  the  first  mixer 
output  signal  level  at  300  mV  p-p.  This 
measurement  is  made  with  transistor  Q7 
removed  from  its  socket,  A  voltage  dividing 
network  optimizes  the  2.5  kHz  oscillator 
signal  to  the  mixer  T8,  limiting  the  drive  to 
550  mV  p-p.  Both  T2  and  T8  coil  data  is 
critical  and  is  listed  in  the  coil  data  chart. 
Table  I. 

In  the  chassis  compartment  just  to  the 
right  of  the  audio  and  453  kHz  board  are  a 
total  of  3  modules.  Toward  the  panel  is  the 
band  selector  crystal  oscillator  stages,  Q14 
and  Q15.  To  the  rear  of  the  band  selector 
is  the  broad  band  second  mixer  Q7  and 
emitter  follower  Q8,  Mounted  on  top  of 
this  board  is  the  third  mixer,  the  double 
balanced  mixer  using  the  latest  techniques, 
and  the  rf  amplifier  QIO. 

The  second  mixer  has  a  fixed  frequency 
input  of  2045  kHz  and  a  vfo  input  of 
2900—3550  kHz,  making  the  usable  output 
frequencies  4945—5595  kHz,  The  problem 
encountered  here  was  to  develop  a 
coupling  circuit  with  a  flat  response  over 
650  kHz,  The  coils  were  wound  on  Vi  in, 
ceramic  slug  tuned  forms,  resistive  loaded 
to  a  Q  of  about  5 ,  The  coils  are  spaced  % 


in.  on  centers.  The  coupling  capacitor  value 
is  very  critical;  the  calculated  value  is  10 
pF  but  in  practice  optimized  out  at  8pF. 
The  circuit  has  a  frequency  response  flat  to 
better  than  2  dB.  Coil  data  can  be  found  in 
Table  L  Unloaded  Q  of  each  coU  is  about 
55.  The  collector  Q7  is  tuned  for  the  low 
frequency  end  of  the  bandpass  while  the 
emitter  of  QS  is  tuned  for  the  high  end. 

T4  and  T5  are  wound  on  4C4  ferrite 
toroids,  3/8  in,  diameter.  Ferrox  cube 
266T125  or  equivalent  may  be  used.  I 
must  have  wound  40  coUs  of  four  different 
diameters  and  Vi  doz.  materials  before 
coming  up  with  a  final  design.  Most  of  the 
materials  tried  seemed  satisfactory  except 
for  the  problem  of  driving  their  low  input 
impedance.  The  key  was  to  select  a 
material  with  high  enough  permeability  to 
obtain  an  input  of  something  over  50n 
using  a  smaU  number  of  turns  and  setting 
the  emitter  follower  current  to  10  or  15 
mA,  All  of  the  information  I  received  from 
engineering  contacts  advised  designing  both 
input  and  output  coils  with  identical 
number  of  turns  but  I  found  this  only  to 
be  true  if  a  very  wide  frequency  range  was 
desired. 


Bottom  view  of  power  supply  and  final  amplifier. 

My  final  design  emerged  with  coils  T4 
and  T5  with  13  and  9  turns  respectively. 
These  coils  must  be  trifilar  wound.  It  is 
recommended  that  the  three  lengths  of 
26-gage  wire  be  of  different  color  so  that 
they  may  be  easily  identified.  This  is  not 
an  absolute  necessity  as  identification  can 
be  made  using  a  continuity  meter.  Twist 
the  three  lengths  of  wire  around  each  other 
and  then  wind  onto  the  toroid  cores, 
spacing  the  turns  evenly  over  the  entire 
circumference  and  then  tacking  into  place 


22 


73  MAGAZINE 


Vfo,  12BY7  driver,  6146s,  tuning  capacitor  for 
3rd  mixer  and  driver,  and  function  switch. 


using  a  small  quantity  of  Polystyrene 
cement.  Use  the  cement  sparingly  as  the 
capacity  effect  is  critical. 

Actually,  the  mixer  has  a  bandpass 
much  wider  than  needed  -  possibly  as 
great  as  200  MHz  —  and  should  the  cement 
spoil  the  higher  frequency  end,  you  will 
never  know  it  as  frequency  interest  ceases 
beyond  30  MHz. 

The  diodes  used  in  the  balanced  mixer 
are  Hewlett-Packard  Schottky  hot  carrier 
type  2900.  The  type  2800  was  found 
equally  good.  Experiments  with  IN269, 
1N270,  and  1N277  types  were  found  to 
operate  satisfactorily  in  this  frequency 
range  also.  The  driving  signal  level  into 
transformer  T4   is  700   mV  (p-p)  and  is 


measured  using  a  two-tone  audio  signal 
source  with  no  carrier  inserted*  Examina- 
tion of  the  schematic  for  the  balanced 
mixer  and  rf  amplifier  (Fig.  4)  reveals 
many  components,  yet  all  are  contained  on 
a  board  I  %  x  1%  in. 

The  only  other  circuits  in  this  compart- 
ment are  the  band  selector  oscillator 
module  and  coil  switch  assembly.  The  rf 
coils  are  mounted  on  a  metal  disk-shape 
shield  which  is  assembled  as  part  of  the 
bandswitch.  (See  ARRL  sideband  manual, 
page  66  for  ideas  on  this  subject.)  Both  the 
rf  amplifier  and  the  12BY7  driver  stages 
are  panel-tuned  by  a  miniature  8  —  108  pF 
two-gang  capacitor.  The  tuning  knob  for 
this  is  located  just  to  the  left  of  center  on 
the  panel. 

The  function  selector  switch  (Fig.  5)  is 
also  panel  mounted.  This  allows  selection 
of  operate,  zero-beat,  CW,  single-tone  test^ 
and  two-tone  test-  The  problem  posed  by 
the  band  selector  stage  (Fig,  6)  was  in 
obtaining  an  equal  output  amplitude  from 
each  crystal.  This  section  had  over  three 
designs  before  the  final  one.  This  may  not 
have  been  a  problem  at  all  if  similar  type 
crystals  had  been  used  but  it  turned  out  for 
the  best  since  the  selection  of  crystal  types 
ceases  to  be  criticaL  It  is  to  be  noted  that 
for  80  and  20  meter  operation  the  same  9 
MHz  crystal  would  be  used.  Although  the 
final  will  tune  from  80  through  10  meters, 
no  coils  were  made  for  the  rf  amplifier  and 
driver  stages  for  the  80  meter  band.  Switch 


noH 


HP  \  I 

ta*0 — v^p — i\ — f 


^F.       mx. 


flSPUT 
ClilTTEit 


GftlD 


TO  rvMCTlOM 
SWJTCH 


14-EOO 
2  GAMS 


Fig,  4-  Balanced  mixer  and  rfamplifiet. 


DECEMBER    1970 


23 


TO  1000  CYCLE_ 
TONE  OSC* 

TO  4O0  CYCLE^ 
TONE  OSC 


U^ 

N 


I 


\ 
\ 
\ 

\ 
i^ 


9 


% 


40qO 


1'  " 


O  ^  O 


N 


#|SV 

SUPPLIES 

RtOM 

+r5V  TO 

n 

0»0  RF 

AMPL 

SUPPLES 
+15V  TO 

TWO  TONE 
TEST  OSC 


SUPfi.CS 

+rsv  TO 

MIKE  AMPL 
WHEH  Xli^T 
SWITCH  IS 
ENGAGED 


♦  ISV 

PROM 

PS 


TO  6V0C 
ON  POWE^ 

SUPPLY 


V 

\ 


TO  CUT  OFF 

SIAS  ON 
t28Y7  STAGE 


TO  -28  VDC 

ANTENNA 
l?ELAY 
SUPPLY 


TO  FIELD     , 

TERMINAL  X* 

OH  HIGH 

VOLTAGE 

RELAY 


Fig.  5.  Function  switch. 


positions  are  provided  and  80  meter  coils 
can  be  incorporated  at  a  later  date  if 
desired. 

Because  of  the  650  MHz  maximum 
frequency  coverage  of  the  vfo  it  will 
require  three  crystals  to  completely  cover 
the  10  meter  band,  A  23  MHz  crystal 
covering  27.945-28.595,  a  23.6  MHz 
crystal  covering  28.545 —29 J 95  and  24,2 
MHz  for  29.145^29.795.  Other  combina- 
tions can  be  used  of  course.  In  that  these 
cannot  be  switched,  one  must  decide  what 
third  of  the  band  is  desired  at  a  time, 
changing  crystals  in  order  to  move  to  any 
other  third  of  the  band.  It  would  be 
possible  to  design  a  board  and  switching 
arrangement  containing  all  crystals,  making 
it  possible  to  switch  to  any  portion.  My 
interests  in  this  band  do  not  go  to  this 
extent  and  I  am  satisfied  to  pick  mine  a 
third  at  a  time. 

The  largest  board  on  the  bottom  of  the 
chassis  is  the  one  containing  the  mike 
amplifier,  mechanical  filter  and  i-f  ampli- 
fier 6  X  P/iJ  in.  Actually  the  entire  exciter 
portion  takes  up  only  one  third  of  the 
chassis  space. 

The  vfo  module  is  contained  in  its  own 
shielded  box  and  is  located  on  top  of  the 


chassis  and  in  front  of  the  box  containing 
the  crystal  carrier  oscillator,  buffer,  and 
balanced  modulator.  Incidentally,  these 
two  modules  were  completed  about  a  year 
before  other  modules  of  the  transmitter, 
including  construction  of  the  basic  chassis. 
The  vfo  (Fig.  7)  was  designed  using  a 
tuning  capacitor  out  of  an  ARC-5.  As  you 
know,  this  capacitor  is  considered  as  fine  in 
quality  and  stability  as  any  obtainable.  The 
oscUlator  coil  is  wound  on  a  ribbed  ceramic 
form  %  in.  in  diameter.  The  big  problem 
with  this  stage  was  developing  a  pure  sine 


II  1  W**i 


-tk* 


Fig.  6.  Fixed    crystal    oscillBtor    to   third  mixer 
(double-balanced  mixer). 


24 


73   MAGAZINE 


SR-2000  thaf s  what,  the  Hallicraf  ters  SR-2000  trans- 
ceiver is  packed  with  watts.  2000  watts,  that's  WATTS 
of  power,  you  can  buy  it  today. 


FEATURES:  <  1  KG  readout  •  ex- 
clusive RIT  (Receiver  Incremental 
Tuning)  •  AALC  Amplifred  Auto- 
matic Level  Control  •  built-in 
Noise  Blanker  •  100  kHz  crystal 
calibrator,  VOX,  PTT,  Break-in  CW 
•  <  1  uv  sensitivity  for  20  db  S: 
N/N  •  compact  rugged  cabinet  • 
2000  watts  SSB,  1000  watts  CW 
in  a  package  only  7%  x  161^  x  15 
inches  •  P-2000  AC  power  supply 
including  built-in  speaker,  final 
amplifier  plate  metering,  110/220 
VAC  •  See  WATTS  UP  at  your  lo^ 
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fhm  hafficrafh 


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600  HICKS  ROAD 
ROLLfNG  MEADOWS,   ILLINOIS    60008 


I 

I 


:3,€<< 


<«oo 


GI3 


^^ 


1^ i ♦ 4 •- — ♦ 1 


TO  Q7 


Fig.  7.  Variable  frequency  osciUator  (2.9—3.5S  kHz). 


wave  (undistorted)  rf  output  signal  across 
the  band.  This  was  finally  obtained  after 
designing  an  amplifier  (Q12)  and  emitter 
follower  (Q13)  that  reduced  the  loading  on 
the  tunable  oscillator. 

An  HP  counter  and  temperature- 
controlled  oven  were  used  for  the  process 
of  stabilizing  the  oscillator.  Critical  com- 
ponents are  CI,  C2j  and  C3.  CI  and  C3  are 
silver  mica  dogbones  while  C2  comprises 
four  separate  capacitors  (2  ea.  68  pF 
N-750S,  a  21  pF  N-330,  and  a  63  pF  NPO 
all  in  parallel).  Looking  back  over  my  data, 
the  temperature  tests  were  run  for  over 
two  weeks.  Frequency  drift  is  1 1  Hz  for  a 
change  of  IS'^F  over  the  vfo  frequency 
range  of  2.9—3*5  kHz,  Once  this  module 
was  completed,  the  unit  was  closed  com- 
pletely and  not  opened  again  until  pictures 
were  recently  taken  of  the  entire  trans- 
mitter-  At  that  time,  only  the  top  cover 
was  removed. 

At  the  time  this  unit  was  designed  I  did 
not  know  what  output  voltage  would  be 
required  to  drive  the  second  mixer  as  plans 
for  this  stage  were  still  quite  a  way  down 
the  road.  Hence,  a  multi tapped  coil  with 
output  from  1*0  to  2,5V  p-p  was  made. 
This  turned  out  to  be  a  bad  guess  as  the 
output  from  the  lowest  tap  was  more  than 
optimum.  Rather  than  go  back  and 
redesign  the  coil  (T9),  a  22J2  series  resistor 
to  tiie  emitter  of  Ql  was  incorporated, 
thus  optimizing  the  second  mixer  for  the 
best  output  waveshape.  It  is  suggested  that 
anyone  duplicating  this  design  use  a 
secondary  winding  on  the  3/8  in,  diameter 
ceramic  slug-tuned  T9  form  of  12  turns 
tapped  at  4  and  8  turns,  rather  than  the 


information  as  given  in  the  coil  table.  No 
series  resistor  is  needed  if  this  winding  data 
is  used. 

The  two-tone  oscillator  (Fig.  8)  is 
located  in  the  same  compartment  with  the 
2,5  MHz  oscillator  and  buffer  module  and 
is  mounted  to  the  back  side  of  the  chassis 
in  a  vertical  position. 


♦15V 


.002 


TO  ARM  OF 
500  a  pot 
\H  AUDIO 
INPUT  CKT 


10)C 


.002 


+J5V 


Fig.  8.  Two-tone  oscillator  schematic. 


The  vswr  indicator  circuit  was  con- 
structed so  that  all  components  could  be 
mounted  in  the  space  below  the  rf  tuning 
capacitor.  The  right-hand  portion  of  the 
chassis  contains  the  regulated  power  sup- 
plies (Fig.  9).  A  module  containing  all  of 
the  rectifier  diodes  as  well  as  the  complete 


26 


73  MAGAZINE 


iTfcfiPif^  itrntQ 


TO  iiF  niiM 


iiTV 


l||  14  m*.  WTH  ?M  m*  FIN*L  CUIWENT 
*iOOV 

a  pj_*T£ 


30  n*  <IF1TH  ri*rlL  OFF 


<9  *av    TD  All  rHMititmt  rrjrics 


F^,  9.  Power  supplies  for  SSB  tran^iutter. 


component  circuitry  for  the  low-voltage 
and  antenna  relay  supply  mounts  on  the 
side  of  the  chassis. 

The  high-voltage  transformer  is  hermeti- 
cally sealed,  containing  three  centertapped 
secondary  windings.  The  63V  winding 
serves  three  functions:  furnishes  the  6,3V 
needed  for  tube  heaters,  it  operates  the 
high-voltage  relay ,  and  it  furnishes  3J5V 
primary  power  to  operate  a  separate  trans- 
former for  the  bias  supply.  The  high- 
voltage  rectifier  string  is  made  up  of  8 
1N2684,  600  PIV- diodes,  each  shunted 
with  390  kQ  resistors  and  0.002  mF  (1 
kV)  capacitors  for  transient  suppression. 

The  ac,  line  switch  has  a  configuration 
that  turns  on  the  low  voltage  dc  supply  in 
its  center  position  and  adds  line  power  to 
the  high-voltage  supply  in  its  up  position. 
The  function  switch  is  a  three-deck,  five- 
position,  seven-circuit  affair  made  up  from 
an  Oak  switch  kit. 

Function  Selector 

Function  positions  are  as  follows;  Side- 
band, tune,  CW,  single-tone,  and  two-tone. 


Positions  1  and  2  are  similar  except  that  in 
position  1  there  is  no  supply  voltage  on  the 
third  mixer  until  the  transmit  switch  is 
activated.  In  position  2,  voltage  is  supplied 
to  the  mixer  and  by  inserting  carrier;  the 
vfo  can  be  set  to  zero  beat  in  the  receiver 
at  the  desired  frequency.  This  condition  is 
not  desired  on  position  1  as  it  may 
interfere  with  the  reception  of  the  station 
being  worked - 

In  the  CW  position,  voltage  is  removed 
from  the  audio  stages,  and  B+  is  suppUed 
to  the  driver  and  final.  The  telegraph  key 
interrupts  B+  to  both  the  second  and  third 
mixers  as  well  as  the  transistor  rf  amplifier 
stages.  Positions  4  and  5  provide  voltage  to 
one  or  both  of  the  tone  generators,  respec- 
tively. 

The  transmit  switch  is  the  multileaved 
telephone  switchboard  type,  and  in  the 
transmit  mode  controls  the  following:  cuts 
the  bias  voltage  to  the  12BY7  driver, 
energizes  the  high-voltage  and  antenna 
relays,  supphes  voltage  to  the  audio  ampli* 
fier  and  third  mixer,  and  switches  the 
standby  and  on  the  air  panel  lights. 

.  .  .  W6YUY  ■ 


DECEMBER    1970 


state 


Control 


Exciters 


The  conventional  approach  to  solving 
the  critical  problem  of  tuning  a  side- 
band receiver  is  to  use  lots  of  bandspread 
and  a  very  good  mechanical  knob  linkage 
to  give  very  fine  tuning  adjustment  capa- 
bility with  little  backlash.  Sometimes, 
though,  even  the  best  knobs  get  jerky  and 
develop  some  backlash  after  a  hundred 
hours  use  or  so.  The  only  difference 
betv^een  very  good  knobs  and  not-so-good 
knobs  is  the  amount  of  this  jerkiness. 

To  forever  remove  this  backlash  prob- 
lem and  give  you  a  degree  of  tuning 
fineness  such  as  no  mechanical  dial  can 
approach,  you  need  only  add  a  simple 
diode  variable  capacitor  for  precision  fre- 
quency shifting,  or  *'delta  frequency"  con- 
trol. 

The  best  amount  of  delta  frequency  {^f) 
for  amateur  use  appears  to  lie  between  200 
and  400  Hz,  The  fellows  with  separate 
transmit  and  receive  controls  have  an  awful 
time  staying  on  frequency  in  a  roundtable, 
and  I  frequently  have  to  shift  the  full  400 
Hz  from  the  operating  frequency  to  reach 
the  worst  of  them.  This  control  is  especi- 
ally necessary  to  tune  in  a  feminine  voice, 
since  the  exactness  of  tuning  SSB  gets  very 
critical  as  the  voice  pitch  gets  higher*  1  have 
never  been  able  to  get  clear  reception  on 
female  ops  with  my  mechanical  dial,  but 


with  the  vernier  ^  there  is  one  critical 
frequency  where  their  voices  clear  up 
noticeably. 

This  control  is  a  must  for  the  serious  ^ 
phone-patch  operator,  too,  since  hams  who 
develop    a    facility    for    understanding   a 


TEST  f^OtNT 

?  M0-13VREG 


180K 


irt29S 


^^ 


TO  ROTOR  (VFOJ 


CI 
.06 


C3 


if     h; 
3K      > 


1 


TO  STATOB  iVFOJ 


&p^ 


C2 


.05 


T 


♦  TO  ROTOR  (VFOJ 


/77 


Fig.  1.  Schematic  diagram  of  ''delta  frequency 
vernier  control  for  SSB  receivers. 


ft 


highly  garbled  SSB  voice  forget  that  the 
layman  does  not  have  this  tolerance,  and 
can't  understand  even  a  slightly  garbled 
voice.  In  receiving  an  off-tune  patch,  they 
will  be  polite,  but  they  may  be,  in  reality, 
missing  much  of  it. 


28 


73  MAGAZINE 


This  critical  nature  of  SSB  has  to  do 
with   the  harmonics  and  overtones  of  the 

voice,  all  being  shifted  the  same  number  of 
hertz  instead  of  being  shifted  the  same 
percentage  of  frequency.  You  wlio  have 
tape  recorders  are  probably  aware  of  the 
fact  that  the  voice  doesn^t  appear  to  suffer 
much  if  the  tape  speed  is  slightly  wrong, 
although  music  does  protest  some.  With 
the  same  degree  of  error  in  frequencies, 
applied  as  a  frequency  offset  (which  is  the 
same  number  of  hertz  regardless  of  fre- 
quency), even  voices  become  seriously  gar- 
bled,  and  music  comes  out  as  total  non- 
sense. If  you  doubt  how  critical  thisis^  try 
to  tune  in  music  on  one  of  the  foreign  BC 
stations  with  your  sound  just  right  unlil 
you  get  zero  frequency  error  and  the 
proper  phase,  within  about  90  degrees  of 
the  station  carrier-  Even  with  this  vernier 
control  J  you  won't  find  it  easy  to  tune  to 
music,  since  a  phase-lock  receiver  and  resi- 
dual carrier  must  be  used  to  get  phone  com- 
pany quality  out  of  SSB. 

The  circuit  for  the  ^f  control  is  shown 
in  Fig,  K  As  indicated,  the  only  adjustment 
device  added  to  the  existing  receiver  is  the 
tuning  pot,  which  can  be  mounted  any- 
where you  please.  A  shielded  line  of  a 
three-wire  twisted  line  can  feed  it.  Since 
onJy  dc  is  present  on  these  lines,  their 
length  is  of  no  consequence.  However,  this 
is  a  moderately  high  impedance  circuit  of 
up  to  about  3  kn,  so  keep  the  pot  leads 


The  entire  cu^cuit  can  be  placed  neatly  within  the 
existing  space  of  n^ost  transceivers.  This  photo 
shows  the  components  mounted  near  the  vfo 
capacitor  in  a  Galaxy. 

DECEMBER    1970 


Barker  & 
Williamson 

Now  Offering 
TVaters  Pretax^  " 

COAXIAL 
SWITCHES 


WITH  AUTOMATIC  GROUNDIIMG 

. .  automatically  grounds  entire 
antenna  system  wlien  the  rig  is 
not  in  use! 


MODEL 
375 

6-Positjon 
rear-mounted 
(axial  connectors) 


MODEL 
376 

5-Position 

side-mounted 

(radial  connectors) 


Precision  built  by  B  &  W  to  the  same 
standards  that  escalated  our  coaxial 
switch  line  to  its  present  enviable 
position  in  the  field. 


BW 


Barker  & 
'Williamson 
Incorporated 

CANAL   ST.,  BRISTOL,   PA.    19007 


See  your  local  dealer  or  write  dep  t.  D  for 
descriptive  literature. 


'   ' 


I 


29 


1 


away  from  ac  lines  or  you  might  induce 
enough  ac  to  FM  your  vfo  a  small  amount. 

Placement  of  parts  is  not  critical,  but 
keep  the  components  attached  to  the  vfo 
tuning  capacitor  rigid,  or  the  whole  thing 
will  be  microphonic-  Keeping  reasonably 
short  leads  on  the  components  wUl  ac- 
complish this  objective  just  fine. 

The  pot  I  used  was  a  used  3  kl2  TV  pot. 
I  drilled  a  3/8  in.  hole  in  the  front  panel, 
and  mounted  it  as  shown  in  the  photo. 
Whatever  pot  you  decide  to  use,  make  the 
hole  in  the  panel  far  enough  away  from  the 
calibrated  dial  to  keep  the  pot  from  rub- 
bing the  dial  after  it's  installed,  A  small 
diameter  pot  makes  things  a  lot  easier. 

Tunetip  Procedure 

Before  connecting  capacitor  C3  to  the 
vfo  St  a  tor,  tune  in  a  carrier  and  zero-beat 
the  signal  on  your  SSB  receiver.  Use  your 
oystal  calibrator  if  it  is  of  the  100  kHz 
marker  type,  or  use  a  commercial  BC 
station  that  is  easily  identifiable ,  Pick  a  low 
vfo  frequency  so  that  your  vfo  tuning 
capacitor  is  almost  completely  meshed. 
This  minimizes  the  frequency  shift  when 
you  connect  C3.  Set  the  3  kO  pot  to  its 
center  of  range  and  connegt  the  free  end  of 
capacitor  C3  to  the  stator  of  the  vfo  tuning 
capacitor.  The  carrier  that  was  zero-beat 
will  shift  frequency  as  you  do  this  because 
you  just  added  a  couple  pF  capacitance  in 
parallel  with  the  vfo  tuning  capacitor.  You 
will  have  to  remove  an  equal  amount  from 
the  trimmer  on  the  vfo  to  bring  back  the 
zerO'beat  on  the  same  carrier  you  had 
before.  (Be  careful  not  to  zero-beat  an- 
other carrier!) 

To  remove  the  capacitance,  unmesh  the 
vfo  trimmer  just  enough  to  zero-beat  the 
carrier  like  it  was  before  you  attached  C3, 

That's  all  there  is  to  it:  your  vfo  is  now 
back  in  perfect  alignment,  and  you  will  be 
able  to  shift  the  frequency  up  and  down 
about  300  Hz  with  the  pot. 

Diodes  to  Use 

I  used  a  1N925  TV  video  detector 
dlode^  but  just  about  any  type  will  work. 
Since  we  are  only  using  a  couple  of 
picofarads  of  the  diode  in  parallel  with  30 
pF  or  more  of  vfo  tuning  capacitance,  it 


matters  little  whether  the  diode  is  a  low-Q 
computer  diode,  a  detector  diode,  or  a 
high-Q  varicap.  If  the  diode  you  use 
doesn't  give  you  enough  shift,  just  reduce 
the  value  of  R2  some  (not  below  10  kO, 
though)  or  increase  the  value  of  C3  (not 
above  about  10  pF). 

This  ^  control  shifts  both  transmitter 
and  receiver  frequencies;  therefore,  in  a 
round  table  discussion,  if  you  tune  off  to 
hear  a  station,  go  back  to  the  original  pot 
setting  before  transmitting.  If  the  other 
feUow  has  a  transceiver,  leave  the  pot 
where  you  hear  him  best,  since  this  auto- 
matically makes  him  hear  you  best  also. 

More  elaborate  circuits  can  be  designed 
which  automaticaEy  return  your  vfo  to  the 
center  range  of  the  pot  when  you  transmit, 
by  using  a  contact  on  your  transmit  relay 
and  putting  a  fixed  bias  on  the  diode  when 


If  you  don't  mind  boring  a  small  hole  in  the  face 
of  your  transceiver  you  are  sure  to  find  a  handy 
spot  for  the  adjustment  shaft.  This  one  was 
placed  in  the  upper  left  corner^  right  above  the 
vfo  dial 

you  transmit-  The  desu-ability  of  this  is 
questionable,  however.  With  this  circuit, 
simplicity  is  foremost,  and  in  a  regular 
QSO,  you  just  adjust  the  pot  to  hear  the 
other  party  and  leave  it- 
Should  you  tremble  at  the  thought  of 
poking  a  hole  in  your  *'store-bought"  rig^ 
bring  the  pot  wires  out  to  a  little  handy 
box,  so  you  can  remove  every  trace  of  your 
modification  later  if  you  desire,  I  per- 
sonally would  pay  more  for  a  used  rig  with 
this  control,  but  to  each  his  own.  You  can 
also  calibrate  the  pot  in  hertz  if  you  have  a 
calibrated  af  generator  to  compare  its  shift 
with. 

.  .  ,  W4NVK  ■ 


30 


73  MAGAZINE 


HAMS 


area 


PuNnY  BuNcH 


o 


f 


PEoPle! 


AI  Brogdon,  K3KM0 
RFD  1    Box  390A 
State  College  PA  16801 

Hams  are  a  funny  bunch  of  people. 
They  will  work  for  days  with  their 
beam  antenna  orientation  to  make  sure  it  is 
pointed  to  within  one -half  degree  of  the 
indicated  direction  -  never  considering  the 
fact  that  the  beamwidth  of  the  antenna  is 
40  degrees. 

They  will  overload  their  transmitters  by 
factors  of  50%  or  more*  and  milk  that  last 
watt  out  of  it  —  when  it  takes  a  power 
increase  of  four  times  to  make  one  S-unit 
difference. 

They  will  stay  oul  of  a  ham  club  and 
complain  until  the  cows  come  home  about 
how  poorly  it  is  run.  But  they  never  want 
to  join  and  work  to  straighten  out  the 
club's  problems. 

They  will  spend  five  hours  and  more  a 
day  building  and  installing  ham  equipment, 
telling  the  wife  all  the  while  that  they  just 
don't  have  time  to  put  a  new  line  cord  on 
her  iron. 

Some  of  them  will  crank  their  final 
amplifiers  up  a  little  and  run  3  kW  PEP, 
never  thinking  about  the  fact  that  they 
would  have  to  run  more  than  5  kW  to 
make  a  significant  difference  in  signal 
strength  above  2  kW  PEP.  A  few  of  these 
hams  have  time  to  think  this  over  during 
their  license  suspension  period. 

They  will  spend  hours  every  day  talking 
with  people  all  over  the  world,  but  never 
say  hello  to  their  next  door  neighbor. 

They  will  tell  their  wives  they  can't 
afford  a  new  chair  for  the  living  room 
while  they  are  writing  out  the  order  for  a 
new  S700  mobile  installation. 


They  will  buy  surplus  equipment  to  save 
money,  and  then  spend  an  amount  of 
money  on  it^s  conversion  that  would  have 
bought  good  commercial  gear  that  would 
have  done  the  same  job  better. 

They  will  set  up  stations  with  which 
they  could  communicate  their  ideas,  but 
they  they  will  give  a  signal  report,  a  brief 
weather  report,  a  description  of  their 
station,  and  run  out  of  things  to  talk 
about. 

They  will  spend  an  entire  48-hour 
contest  period  at  the  rig,  leaving  it  only  to 
catch  short  naps  and  take  care  of  necessary 
bodily  functions,  but  during  the  week  they 
can't  spare  1 0  minutes  of  their  time  to  play 
with  their  kids. 

They  will  buy  complex  and  expensive 
electronic  keyers  so  the  extra  dots  and 
dashes  their  sloppy  keying  causes  will  be 
well-formed  and  correctly  spaced. 

They  use  Q  signals  on  voice,  and  then 
have  to  use  phonetics  to  get  the  letters 
across,  since  voice  is  better  suited  for 
communicating  words  than  for  trans- 
mitting individual  letters. 

They  will  apply  for  every  ham  award 
they  can  qualify  for  to  document  their 
accomplishments^  when  many  of  the  certi- 
ficates are  for  a  level  of  accomplishment 
roughly  equivalent  to  being  able  to  cross 
the  street  without  getting  run  over. 

They  will  load  half  a  ton  of  amateur 
gear  and  antennas  into  the  car  and  take  off 
for  Field  Day,  but  then  have  to  suspend 
operation  halfway  tlirough  the  contest 
because  the  didn't  bring  a  spare  fuse* 

They  will  take  great  pride  in  being  a 
ham  radio  operator,  and  tell  all  their 
nonham  friends  of  the  many  accomplish- 
ments of  ham  operators,  and  of  the 
advances  in  the  state  of  the  art  brought 
about  by  hams,  when  they  themselves 
haven't  been  on  the  air  in  three  years. 

But  one  of  the  funniest  things  of  all 
about  hams  is  the  typically  human  short- 
sightedness of  most  hams.  They  see  all  the 
faults  of  their  fellow  hams,  and  they  are 
quick  to  criticize,  but  they  are  not  aware 
of  their  own  shortcomings.  Aren't  you  glad 
that  you  and  I  aren't  that  way? 

.  ,  .  K3KMO  ■ 


DECEMaER    1970 


3T 


Clifford  Klinert  WB6BIH 
520  Division  St 
National  City  CA 


A2M 


For  Repeater  Use 


When  an  FM  repeater  finally  came  to 
San  Diego  last  summer  it  was  soon 
obvious  that  new  possibilities  and  require- 
ments were  placed  on  2  meter  FM  equip- 
ment. First  of  all,  high  transmitter  power 
was  no  longer  required  nor  desirable.  In 
many  cases  output  power  in  the  milliwatt 
level  was  adequate  to  activate  the  repeater 
since  it  is  virtually  line-of-sight  to  most 
parts  of  the  county.  Also,  high  power  on 
146.34  MHz  would  cause  interference  with 
Los  Angeles  area  remote  stations  that  are 
similarly  located  on  high  mountain  tops. 
This  would  add  further  strain  to  already 
deUcate  relations  with  the  Los  Angeles 
groups  who  can  (and  do)  jam  San  Diego 
just  as  easily.* 

Secondly,  a  large  number  of  RCA 
CPCR2D  pocket  receivers  had  become 
available  for  portable  use,  but  the  trans- 
mitters available  with  them  were  not 
transistorized  and  the  batteries  were  heavy 
and  expensive.  With  this  arrangement,  and 
with  the  repeater,  it  became  possible  to 
have  full  use  of  the  repeater  while  walking 
around  on  the  ground  in  most  parts  of  the 
area.  This  is  probably  the  most  fascinating 
part  of  repeater  operation,  approaching  the 
science-fiction  TV  shows  by  being  able  to 

*  Ed.  Note:  Author  is  making  reference  to  L.A/s 
R-0-B.LN-  (Remotes Operated  By  Insociable  Nets) 
problem. 


talk  to  someone  a  hundred  miles  or  more 
away  while  walking  around  on  the  streets 
of  a  city  with  a  handrheld  transceiver. 
However,  the  idea  of  having  to  carry  tubes 
and  batteries  while  doing  tiiis  was  still 
quite  revolting.  Solid-state  transceivers  are 
becoming  available,  but  are  still  in  the 
$250  to  $350  price  range.  In  view  of  this, 
it  was  finally  decided  to  continue  work  on 
a  solid-state  transmitter.  This  article 
describes  the  first  successful  results  of  that 
project. 

Design 

Figure  1  shows  the  schematic  of  the 
transmitter  as  it  is  now.  The  most  signifi- 
cant part  is  the  oscillator,  which  offers 
maximum  simplicity  and  reliability.  The 
crystal  frequency  is  18.29250  MHz,  and  is 
multiplied  eight  times  to  get  the  14634 
output  frequency.  Amateur  designs  of 
about  a  year  ago  used  oscillator  frequencies 
in  the  8  MHz  or  lower  range.  With  the 
sloppy  interstage  selectivity  as  used  in  this 
transmitter,  lower  frequency  crystals  cause 
more  spurious  multiples  because  they  are 
closer  together  in  frequency.  With  a  crystal 
trequency  of  18.0  MHz,  the  multiples  will 
be  at  least  18  MHz;  apart,  and  it  is  easier  for 
the  tuned  circuits  to  select  the  proper 
multiple  and  reject  others.  A  Motorola 
varicap  is  used  to  modulate  the  oscillator. 
With    an    audio    input    of    about    22.5V 


32 


73  MAGAZINE 


peak-to-peak  (maximum  bias  on  the  diode 
from  the  power  supply),  the  deviation  is  a 
little  more  than  the  5  kHz  at  the  output 
frequency.  Two  varicaps  might  be  used  in 
parallel  if  more  deviation  is  desired  —  if  it 
doesn't  lower  the  frequency  too  much  to 
compensate  by  lowering  other  capaci- 
tances. 

A  few  notes  about  the  crystal  should  be 
made:  The  crystal  must  be  a  "funda- 
mental" cut  to  work  in  this  circuit.  An 
overtone  crystal  will  oscillate  on  its  fun- 
damental frequency,  and  will  be  different 


the  transistors  increases  at  lower  frequen- 
cies, it  i^  possible  to  have  low-frequency 
feedback  paths  that  have  been  overlooked 
while  concentrating  on  the  VHF  circuitry. 

Using  the  coil  in  each  stage  for  the  dc 
return  to  the  collector  not  only  simplifies 
design,  but  provides  a  low-impedance  col- 
lector return  for  lower  frequencies  that 
would  not  be  possible  if  choke-and- 
capacitor  coupUng  were  used. 

The  final  transistor  can  be  driven  to  as 
much  as  2W  dc  input  in  this  circuit,  but 
was    held    to    one    watt    to    reduce    heat 


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La^  L4-ST.  TAP  AT  I  ST   F1?Q«f  [>C  EMI 


Fig.  1,  Schematic* 


from  its  marked  frequency.  The  crystal 
load  capacitance  in  this  circuit  is  about  20 
pF  and  this  should  be  noted  in  the  crystal 
order.  A  general-purpose  type  crystal 
(0,01%  error)  might  be  satisfactory,  but  a 
commercial-standard  0.00 1  %  crystal  was 
ordered  by  maiL  and  quickly  tweaked 
down  on  frequency  with  the  15  pF  trim- 
mer. 

The  three  stages  following  the  oscillatoT 
are  all  conventional  common-emitter, 
LC-coupled  doublers.  While  operating,  they 
are  driven  into  class  C.  Interstage  matching 
is  accomplished  by  trial-and-error  tapping 
of  the  coils. 

The  use  of  ordinary  resistors  in  the  base 
bias  circuit  was  found  to  be  most  success- 
ful, TMs  avoids  the  resonance  problems 
when  chokes  are  used,  and  probably  helps 
stability  by  lowering  circuit  Q.  Large 
capacitance  (0,01  juF)  bypass  capacitors 
were  used  to  minimize  the  chances  of 
low-frequency  oscillation.  Since  the  gain  of 

DECEMBER    1970 


dissipation  problems  and  battery  require- 
ments. Power  can  be  adjusted  by  changing 
the  value  of  the  emitter  resistors  in  the 
multiplier  stages,  and  changing  interstage 
couphng-  (Ed.  Note:  This  unit  can  be  used 
to  drive  the  DyComm  15\V  FM  power 
amplifier  described  in  73  review,  Septem- 
ber 1970J 


05 
2N3e66 


ANT. 


Fiq,  2.  AlXQvnale  Oulpui  Circuit.  L  can  be  five  or 
six  turns  3/8  inch  diameter ^  ^18  wire.  Try  to 
make  it  work. 


33 


A  more  popular  output  tuned  circuit  is 
iuciuded  in  Fig,  2^  but  it  was  not  tried  in 
the  transmitter  because  the  circuit  used  in 
Fig.  1  was  considered  satisfactory. 

Construction  and  Tuning 

Simply  having  a  schematic  available 
does  not  mean  that  it  will  be  easy  to  build 
a  transmitter.  Construction  is  very  simple, 
but  making  it  work  will  occupy  the  major- 
ity of  the  time.  Since  all  transistors  are 
different  and  any  two  transistors  with  the 
same  number  can  have  widely  different 
impedance  and  gain  parameters,  the  tuned 
and  coupling  circuits  will  require  extensive 
adjustment.  Many  of  the  values  in  the 
schematic  will  probably  be  a  little  different 
in  different  transmitters. 

Considerable  experience  as  well  as 
appropriate  test  equipment  is  required  for 
the  tuning  and  tweaking-  A  grid  dip  oscil- 
lator is  a  must,  and  a  general-coverage 
receiver  that  cuw  cover  all  the  frequencies 
between  the  oscillator  and  final  output  is 
always  handy.  An  swr  bridge  or  power 
meter  that  works  at  VHF  is  necessary  for 
tuning  for  output  power,  as  well  as  all  the 
other  tools  and  test  equipment  that  are 
usually  available  in  the  average  shack. 


his  own  pet  methods  and  parts  available  to 
work  with.  As  a  final  resort,  industrial 
parts  catalogs  will  list  all  the  components 
necessary. 

Speaking  of  parts,  half-watt  resistors  can 
be  used,  but  quarter- watt  resistors  will  be 
easier  to  work  with  because  of  size.  In  the 
case  of  the  driver  and  final  emitter  resis- 
tors, power  considerations  will  necessitate 
the  use  of  half- watt  resistors.  Small  dipped 
mica  capacitors  are  used  for  interstage 
coupling.  Other  than  the  feed  thro  ugh 
bypasses,  disc  ceramic  capacitors  were  used 
for  bypassing.  Indeed  they  are  not  the  best, 
but  seemed  to  work  in  this  case.  Just  make 
sure  that  all  parts  are  as  small  as  possible, 
JFD  makes  good  ceramic  bypass  capacitors 
as  well  as  small  disk  variable  capacitors. 
The  crystal  holder  is  the  HC-18/U  type  and 
is  soldered  into  the  circuit. 

The  transmitter  should  be  built  one 
stage  at  a  time,  starting  with  the  oscillator. 
Each  stage  should  be  checked  and  tuned  as 
it  is  built.  The  oscillator  will  be  easy 
because-  there  is  nothing  to  t-une  but 
frequency  adjustments  and  the  circuit, is 
very  easy  to  get  working.  Check  for  output 
while  listening  to  a  receiver  tuned  to  the 


Pbotograpb  of  the  complete  minitransmitter  strip^  Note  how  stages  are  shielded  into  '^compartments. 


ft 


The  circuit  was  laid  out  on  a  double 
clad  printed  circuit  board  that  makes  a 
very  simple  arrangement.  Small  Teflon 
standoffs  were  glued  to  the  board  with 
epoxy  to  provide  a  place  to  solder  the 
transistors.  Details  of  the  construction  and 
parts  to  be  used  will  mostly  be  left  to  the 
individual  builder.  Anyone  who  would 
build  this  transmitter  probably  would  have 


crystal  frequency.  Adjust  the  two  resistors 
that  provide  the  bias  to  the  varicap  to  put 
the  diode  voltage  at  about  lOV  measured 
at  the  diode— crystal  connection  with  a 
VTVM  or  oscilloscope. 

An  audio  signal  voltage  can  be  applied 
at  the  "audio  in"  point  in  the  schematic. 
Make  sure  that  the  audio  source  is  isolated 
with  a  series  capacitor  to  prevent  affecting 


34 


73  MAGAZfNE 


IF  YOU'VE 


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1970  Catalog  of  Precision 

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SENTRY 


Somewhere  along  the  line,  in  vir- 
tually every  ham  repeater  in  the 
world,  you'll  find  a  coupfe  of  Sentry 
crystals. 

Repeater  owners  and  FM  "old- 
timers"  don't  take  chances  with 
frequency— they  can't  afford  to.  A 
lot  of  repeater  users  depend  on  a 
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took  a  tip  from  the  commercial 
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depend  on  your  local  repeater  to  be 
there  (precisely  there)  when  you're 
ready  to  use  it,  FM'ers  use  the 
repeater  output  as  a  frequency  stan- 
dard. And  for  accuracy,  crystals  by 
Sentry  are  THE  standard. 

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SPECIFY  SENTRY  CRYSTALS. 


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check   or  negotiable  securities. 


the  diode  bias.  A  maxiniiim  of  about  20V 
peak-to-peak  can  be  applied  here.  A  pre- 
assembled  imported  audio  amplifier  can  be 
used  for  modulation,  or  an  amplifier  can  be 
buill  to  fit  individual  requirements.  If  the 
amplifier  is  designed  for  driving  a  speaker, 
a  transformer  may  be  necessary  to  step  up 
the  output  voltage.  It  should  be  possible  to 
detect  FM  from  the  oscillator  by  listening 
to  a  general-coverage  AM  receiver  and 
slope^detecting  the  signal. 

Tuning  tlie  multiplier  stages  can  be 
iccomplished  by  measuring  the  emlLler 
voltage  of  the  following  stage  while  tuning 
the  preceding  one.  Voltage  across  the 
emitter  resistor  measures  emitter  current, 
which  is  a  measure  of  rf  drive.  To  deter- 
mine that  the  stage  is  operating  class  C, 
compare  the  emitter  and  base  voltage,  as 
measured  with  a  VOM,  The  emitter  should 
show  more  voltage  than  the  base.  The  base 
never  really  has  more  bias  voltage  than  the 
emitter,  but  when  the  VOM  probe  touches 
the  base,  it  partially  shorts  out  the  rf  there 
and  reduces  or  eliminates  drive.  Since  the 
emitter  is  bypassed,  measuring  emitter  volt- 
age has  no  effect  on  the  rf  drive,  A  grid  dip 
meter  must  be  used  for  the  final  tuning  to 
be  sure  that  the  state  is  operating  on  the 
right  frequency,  and  to  check  for  para- 
sitics. 

The  resistors  across  the  coUs  in  the 
schematic  were  used  as  a  cure  for  parasitic 
oscillations.  The  stage  shoidd  be  built 
without  the  resistor  first,  and  then  resistors 


can  be  added  when  instability  occurs.  A 
grid  dip  meter  can  be  used  to  detect 
parasitics  and  oscillation,  but  an  AM 
general-coverage  receiver  is  much  more 
sensitive. 

Adjusting  the  output  stages  is  just  a 
matter  of  changing  taps  on  the  coils  while 
watching  for  transistor  overheating,  check- 
ing for  parasitics  and  oscillation,  and 
retuning  each  time  for  resonance.  Also  be 
sure  to  check  that  the  right  harmonic  is 
being  tuned  for  on  the  grid  dip  meter  used 
as  a  wavemeter. 

Leave  a  TV  set  turned  on;  it  will  let  you 
know  when  oscillation  breaks  out  and  give 
a  little  entertainment  while  you're  work- 
ing. Watch  channel  eight;  the  36  MHz 
signal  tends  to  come  through  the  72  MHz 
doubler,  and  multiply  five  times  in  the  144 
MHz  doubler  to  cause  TVI  on  channel 
eight.  This  has  been  the  major  source  of  TVI 
after  the  transmitter  was  operating  prop- 
erly, A  36  MHz  series-tuned  trap  might  be 
used  at  the  collector  of  Q3  as  a  last  resort, 
but  witli  proper  tuning  this  should  not  be 
necessary. 

The  final  results  will  take  a  considerable 
amount  of  time  depending  on  the  intuition 
or  "feel"  tliat  the  builder  has  for  what  is 
happening  in  the  circuit. 

Conclusions 

This  transmitter  has  provided  good 
results  in  the  final  analysis,  but  there  are 
problems  and  changes  that  could  be 
worked  out.  The  thing  is  quite  difficult  to 
tune  and  clean  up^  and  some  kind  of 
standard  chassis,  housing,  shield,  board,  or 
whatever  should  be  designed  to  provide 
ease  of  mechanical  construction  and  dupli- 
cation, rf  shielding,  and  mechanical 
strength.  D  o  u  b  le  - 1  u  n  ed,  induct  ively 
coupled  interstage  circuits  might  be  used  to 
provide  better  selectivity.  Tapped  iron 
slugs  are  available,  but  I  haven't  located  a 
source.  Supposedly,  this  would  be  much 
less  expensive  than  using  the  ceramic  vari- 
able capacitors,  and  much  smaller. 

Other  variations  of  this  same  theme 
might  include  a  low-power  100  mW  version 
for  short  range  use  with  an  absolute  mini- 
mum of  size  and  power  consumption.  Be 
creative. 

.  .  .  WB6BIH  ■ 


36 


73  MAGAZINE 


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FiushingNY  11367 


RECE I V 


TUNING  FOR  THE  HW 100 


ant  transceiver  offset  tuning  with- 
out costing  a  cent?  Without  altering 
your  rig?  Give  this  a  try: 

The  introduction  of  the  transceiver  to 
ham  radio  has  brought  many  advantages. 
But  the  one  disadvantage  that  will  force  a 
fellow  not  to  select  a  transceiver  is  its 
inability  to  follow  the  drift  of  a  CW  signal 
without  altering  the  output  frequency. 
This  separation  of  frequencies  was  realized 
by  a  very  simple  method  which  can  be 
employed  in  many  other  rigs.  It  has  two 
good  things  going  for  it:  no  modiiication 
and  no  money  required. 

Theory 

The  theory  behind  this  method  of  offset 
tuning  is  simple  when  you  recall  some  of 
the  laws  we  all  knew  to  get  our  ticket  (and 
then  promptly  forgot  as  they  were  of  no 
practical  value).  Inductive  coupling  is  the 
first  order.  This  is  the  method  by  which  we 
will  get  the  change  into  the  rig  without 
altering  or  soldering.  This  method  will 
allow  you  to  introduce  a  change  in  the 
frequency  of  the  main  vfo.  You'll  also 
want  to  be  able  to  remove  the  change  at 
will,  as  on  transmit.  Figure  1  shows  that 
the  inductive  coupling  links  the  main  vfo 
with  the  added  tuned  circuit.  It  is  with  this 
outboard  tuned  circuit  that  we  can  change 
the  received  frequency.  The  capacitance  of 
the  variable  capacitor  should  be  iow.  Try 
and  keep  it  in  the  area  of  the  tuning 
capacitor  of  the  vfo.  In  my  rig,  the 
HW*100,  this  is  63  pF,  so  anything  near 
that  will  do.  The  vfo  coil  in  my  rig  is  5  juH 
so  1  kept  the  inductor  of  the  remote  circuit 
as  near  to  this  as  possible.   None  of  the 


values  are  too  critical  as  to  demand  adher- 
ence to  strict  values.  By  keeping  close  to 
the  values  of  your  rig  you  will  have  better 
tracking  and  zero  beating  of  the  received 
CW  signal.  And  youMl  know  that  when  the 
remote  tuner  is  switched  out  of  the  circuit 
you  are  still  near  enough  to  be  hearing  the 
same  signal  you  were  listening  to  on  the 
offset  tuning.  The  greater  the  change  in  the 
offset  tuning  circuit  values,  then  the 
greater  the  coverage  up  and  down  fre- 
quency from  the  zero  beat.  I  felt  that  in 
CW  a  great  range  of  offset  tuning  was  not 
of  any  use  and  it  also  would  make  tuning 
more  difficult.  I  just  about  use  the  full 
rotation  of  my  capacitor  and  keep  within 
the  passband  of  my  rig,  the  tuning  rate  is 
slow  enough  that  1  can  move  it  around  in 
the  400  Hz  CW  filter  1  have  added  to  my 
HW-100.  It  is  this  simple  remote  tunable 
circuit  that  allows  the  offset  tuning. 

Construction  and  Circuit 

The  variable  capacitor  1  used  is  a  BC 
tuning  variable  with  only  the  rear  section 
in  use.  If  you  have  any  old  variable  in  the 


>  I 


VFO  ENCLOSURE 


VFO  COIL 


M^ 


^2       Ci  ,      If  /^ 

eOllTACTS  2  6  10 

Fig*    1 


DECEMBER    1970 


junkbox,  then  that's  the  one  you  use.  I 
reduced  the  high  capacitance  of  this 
section  by  putting  a  100  pF  Mylar  capaci- 
tor in  series  with  it,  (You  can  fool  around 
with  values  until  you  get  what  goes  best 
with  your  rig.) 

The  coil  for  the  remote  tuner  was  made 
after  looking  in  the  ARRL  handbook;  I 
found  that  a  I  V2  in,  long  coil  by  ^i  in.  wide 
(36  turns  per  inch)  would  give  me  close  to 
5  juH,  which  is  good  enough.  The  coil  was 
made  by  winding  24-gage  magnet  wire, 
enameled,  around  one  of  those  fat  penciis 
used  for  advertising  gags.  The  size  of  the 
wire  is  not  important  just  so  you  can  get 
about  36  turns  to  the  inch  on  a  half-inch 
diameter 

If  you  have  spent  any  money  up  to  this 
point  you  need  a  new  junkbox.  Now  for 
the  hookup. 

The  vfo  of  the  HW*100  is  removed 
according  to  the  Heath  manual  instruc- 
tions. Reference  will  be  made  to  my 
HW-lOO,  but  any  transceiver  that  allows 
you  to  get  at  the  vfo  and  its  coil  can  be 
used  with  this  offset  tuner.  The  vfo  is 
turned  bottom-side-up  so  the  inside  of  the 
enclosure  is  accessible.  Be  careful  not  to 
damugc  the  screened  diah  One  end  of  the 
pickup  wire  has  its  insulation  scraped  away 
and  it  is  soldered  to  ground  on  the  inside 
of  the  vfo,  as  close  to  the  coil  as  you  can 
manage.  This  is  the  only  soldering  and 
modification  to  the  rig.  In  my  rig,  the 
ground  for  I  lie  coax  feed  through  into  the 
vfo  was  used  as  ground.  With  tension  on 
the  ground  connection,  make  one  full  turn 
around  the  vfo  coil  and  while  still  keeping 
tension  bring  the  wire  to  the  nearest  spade 
bolt.  Wrap  the  hookup  wire  around  the 
bolt  2  or  3  times  Just  for  anchorage.  Make 
these  turns  just  at  the  base  of  the  spade 
bolt  where  it  meets  the  edge  of  the  vfo 
enclosure  and  tuck  the  turns  down  into  the 
little  space  between  the  shaft  portion  of 
the  spade  bolt  and  the  edge  of  the  enclo- 
sure. 

By  tucking  the  turns  of  wire  into  these 
spaces  you  will  keep  them  from  being  cut 
or  grounded  by  compression  from  the  edge 
of  the  vfo  enclosure  when  it  is  remounted 
and  the  nuts  tightened.  It  is  most  impor- 
tant that  the  turn  of  wire  around  the  vfo 


coil  stay  in  place  without  the  least  move- 
ment. Movement  of  any  kind  no  matter 
how  slight,  even  from  vibration,  can  alter 
your  received  signal  a  few  hertz  up  or 
down  the  band.  A  drop  of  some  kind  of 
glue  will  do  the  job  of  keeping  the  wire 
turn  in  place. 

Remount  the  vfo  as  directed  in  the 
Heath  manual.  Make  sure  the  remaining 
free  end  of  wire  is  not  caught  under  the 
edge  of  the  vfo  and  is  outside  the  vfo 
enclosure.  The  wire  is  now  fed  to  SI,  from 
Si  to  CU  to  rotor  of  C2,  then  to  ground 
from  C2. 

ff  automatic  switching  is  desired,  place 
RLl  contacts  2-6-10  before  SI,  The  home- 
brew coil  is  placed  across  the  variable 
capacitor  to  ground,  placing  it  in  parallel 
with  C2.  Keep  all  leads  as  short  as  possible. 
TMs  completes  the  wiring  of  the  remote 
offset  tuner. 

Alignment 

The  transceiver  must  now  be  adjusted 

only  because  the  loop  of  wire  aroujid  the 
vfo  coil  has  moved  the  vfo  frequency  and  it 
will  not  be  the  same  as  the  readout 
frequency  of  the  dial  This  alignment  is 
simple  because  the  vj'o  Is  not  udjuKtetL  This 
is  the  pari  Ihut  can  be  frustrating  at  first 
because  you  do  not  know  where  the 
frequency  has  shifted  to,  I  found  the  turn 
of  wire  dropped  my  vfo  down  30  kHz.  This 
meant  nothing  had  changed  as  far  as 
function  of  my  vfo  except  that  there  now 
was  a  30  kHz  shift  down  the  band.  This 
was  corrected  by  *'slipping"  the  dial  on  the 
rig  until  the  frequency  coming  from  my 
vfo  and  the  readout  frequency  on  my  dial 
were  the  same,  i  used  CHU,  7335  kHz,  as  my 
locating  frequency.  I  used  this  instead  of 
my  signal  generator  only  because  my  trans- 
ceiver receives  CHU  (and  besides.  I  was  too 
iazy  to  set  up  my  signal  generator).  Any 
method  of  obtaining  a  locating  frequency 
IS  fme. 

For  alignment  with  the  offset  tuner  in 
the  circuit,  tune  in  a  CW  signal  on  any 
band  with  the  offset  tuner  out  of  the 
circuit.  I  found  RTTY  signals  to  be  of 
longer  duration  and  more  dependable. 
Adjust  the  vfo  for  the  highest  meter 
reading    of    the   locator   signal.   Place   the 


40 


73  MAGAZINE 


variable  capacitor  of  the  offset  tuner  in  the 
fully  unmeshed  position.  Put  the  offset 
tuner  into  operation  by  closing  SI.  When 
SI  is  closed  you  should  still  receive  the 
same  locator  signal  if  your  capacitor  and 
coil  vahies  are  close  to  the  values  in  your 
rig.  One  thing  you  may  notice  is  a  change 
in  pitch  of  the  locator  signal  due  to  a  slight 
frequency  shift  (but  don^t  worry  about  it), 
I  am  only  interested  in  following  the  drift 
of  a  CW  signal  —  not  in  how  much  fre- 
quency spectrum  my  offset  tuner  ranges 
over  or  in  how  many  hertz  the  CW  signal 
drifts.  (Though  this  can  be  done  if  you  care 
to  take  the  time  to  calibrate  for  it.) 

Adjust  the  variable  capacitor  so  that 
wlicn  the  remote  tuner  is  removed  from 
the  circuit  by  SI,  the  pitch  (frequency) 
will  be  close  to  the  pitch  of  the  signal  from 
the  rig  alone.  What  you  will  be  doing  here 
is  getting  a  zero  beat  for  the  offset  tuner 
against  the  rig.  Try  to  get  this  position  of 
the  offset  tuner  as  close  as  you  can  to  the 
rig's  signal.  Mark  this  zero  beat  position  on 
the  variable  so  you  can  return  to  it  at  any 
time.  Now  when  you're  receiving  and  the 
offset  is  placed  at  zero  beat  you  can  tune 


up  or  down  frequency  as  a  CW  signal  drifts. 
I  found  that  my  zero  beat  on  the  offset  did 
not  change  from  band  to  band-  It  would 
appear  that  alignment  for  one  band  takes 
care  of  all  the  bands.  This  completes  the 
adjustment  and  alignment  of  offset  tuner 
and  the  transceiver. 

Placement 

My  offset  tuner  at  present  is  outboard. 

It  can  be  mounted  in  the  HW- 100  without 
making  holes  in  the  front  panel.  The  screws 
in  the  upper  right  and  left  corners  of  the 
front  panel  are  replaced  by  the  variable 
capacitor  and  the  on -off  switch  (SI).  The 
components  in  this  case  will  have  to  be  of 
the  miniature  type  to  use  the  holes  as  they 
are  now.  To  use  what  comes  out  of  the 
junkbox,  in  my  case,  meant  enlarging  the 
holes.  But  f  think  this  is  one  case  where 
modification  will  add  to  the  worth  of  a  rig 
and  should  not  be  a  deterring  factor.  The 
shame  of  it  all  would  be  spending  money 
for  miniature  parts  after  having  come  this 
far  for  free, 

.  .  ,  WA2EAW  ■ 


FM'ers! 

GET  THESE 

EARLY  ISSUES 

OF  FM 

BULLETIN, 

BOUND  INTO  A 

SINGLE 

VOLUME 


WHILE 
THEY 
LAST 


Only  500  copies  of  this  collector's  edition  have  been  printed.  The 
material  consists  of  FM  bulletin's  rarest  issues,  and  is  reproduced  in 
its  original  form  by  lithography.  Contains  FM  Bulletin,  Volume  I  (Feb. 
1967  to  Feb.  1968). 


a 


DECEMBER    1970 


41 


The  Most  Powerful  Signals  Under  the  Sun! 


PICK  YOUR  PERFORMANCE 

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A^..-v 


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•  Antenna  ImpedanGe:  50  ohms  nominal 

•  Power  Requirements:  12-t4v  DC 

•  Transmitter:  5  watts  (10w  with  AC-210  pow- 
er booster) 

^  Microphone:  High  2 

•  Deviation:  Adjustable  narrow  or  wide  band 
with  clipper  filter  also  adjustable  for  opti- 
mum clipping  lever 

Receiver: 

•  Sensitivity:  SINAD  ,5  uv  for  12  db 


Quieting:  1  uv  provides  20  db 

Squelch:  Continuousty  adjustable 
Modulation  Acceptance;  FM  wide  band  (nar- 
row band  available  on  special  request) 
RF  Circuitry:  FET  front  end  and  duo  con* 
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IF  Frequency:  10.7  MHz  and  455  KHz, 
Frequency  Control:  3  channel  transmit.  3 
channel    receive.    (146.94    MHz   furnished) 
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Audio  Output:  3  watts  from  internal  3.2" 
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•  Input  Voltage:  12vDC.  negative  ground  only 

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•  Operation:  Class  C 

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Drive  Requirements:  SVz  watts  required  for 
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Mi 


John  Aggers  W5ETT 

1509  Desoto 

Ponco  City  OK  74601 


The 

Little 

GATE 
DIPPER 

Covering  f .7—225  MHz,  tt  ts  simple, 
inexpensive,  and  eaSy  to  build. 


Possibly  you  now  own  a  grid  dipper, 
but  is  it  small,  easy  to  handle,  and 
cordless,  making  it  completely  portable?  If 
not,  you  will  want  to  build  this  gate  dip 
meter.  The  cost  is  extremely  low  —  only 
about  $7.  AU  parts  are  readily  obtainable 
and  construction  is  simple.  The  plug-in  coil 
forms,  using  battery  plugs  and  polystyrene 
tubing,  are  easy  to  make. 

The  Circuit 

An  MPF  102  FET  is  used  in  a  modified 
Colpitts  circuit.  Except  for  the  #1  coil, 
where  a  choke  is  used,  the  B+  is  fed  to  the 
centertap  of  the  coil.  This  is  necessary  to 
obtain  a  fairly  constant  gate  current  as  the 
oscillator  is  tuned  to  its  end  frequencies. 
Drain  current  varies  from  4  to  1  mA 
proceeding  from  225  to  1.7  MHz.  At  the 
same  time  the  gate  current  varies  from  20 
to  well  over  50  juA, 

From  this 5  it  is  apparent  that  the 
stronger  the  oscillations  the  smaller  the 
drain  current  and  the  larger  the  gate 
current.  In  gate  dip  operation^  as  power  is 
drawn  from  the  oscillator  the  drain  current 
will  increase  and  the  gate  current  will 
decrease  or  dip, 

Limited  wavemeter  operation,  obtained 
by  switching  off  the  B+j  is  accompanied  by 
a  slight  sliift  in  calibration.  When  the 
circuit  picks  up  rf,  the  FET  suddenly  goes 


into  oscillation  using  the  rf  as  its  battery. 
Thus,  the  amount  of  rf  picked  up  must  be 
large  enough  or  there  will  be  no  oscillation 
and  no  meter  indication.  However,  despite 
these  deficiencies,  it  is  still  considered  a 
useful  mode  of  operation  and  for  that 
reason  has  been  included •  It  is  only  neces- 
sary to  wire  the  sensitivity  control  so  that 
the  resistance  is  maximum  when  the  switch 
is  in  the  off  position . 

Construction 

A  natural  finish  aluminum  minibox  (4  x 
2-f/8  X  1-5/8  in-)  is  used  for  the  meter 
case.  The  variable  capacitor  came  from  an 
old  transistor  radio  and  measured  1  3/8  x 
1/2x1  in.  The  shaft  was  already  squared 
and  tapped  for  a  small  screw.  Since  those 
listed  in  the  catalogs  have  a  plain  or  flat 
shaft,  you  wiU  have  to  use  a  collar  with 
setscrew,  or  drill  and  tap  the  shaft.  The 
trimmer  capacitors  are  not  used  and  should 
be  removed. 

To  make  the  coil  socket  you  will  need 
three  pin  receptacles  from  an  octal  socket, 
two  pieces  of  1/8  in*  Plexiglas  approxi- 
mately 7/8  X  3/4  in.,  and  one  battery  plug 
for  a  pattern.  The  pins  of  the  battery  plug 
form  a  triangle,  I  shall  refer  to  the  holes  at 
the  base  as  the  outside  holes.  Drill  holes  in 
one  piece  of  plastic  to  match  the  pins  of 
the  battery  plug.  Match  the  two  pieces  of 


44 


73  MAGAZINE 


i 


The  little  gate  dipper  with  spm^e  coils. 


001  iiF 


2  PLUG -W 


COILS 


SOURCE 


DRAINV«  *  VGATE 


SWITCH 

OFF 
POSITION 

BAMYTHmG  Fm)li 
5K   TO  K>K 


eOTTOM   VIEW 
liPFI02  FET 


Fig.  1.  Schematic    diagram     of    the    little    gate 
dipper. 


plastic,  clamp  in  a  vise,  and  drill  the  two 
outside  holes  in  the  second  piece.  Bend  the 
lug  part  of  each  socket  pin  to  a  right  angle. 
Slip    one    over    each    outside   pin   of   the 


battery  plug.  Using  this  as  a  jig,  soider  the 
lug  portions  to  the  stators  of  the  variable 
capacitor.  Remove  the  plug,  and  the  pieces 
of  plastic  should  fit  down  over  the  variable 
capacitor.  The  lug  part  of  the  center  socket 
pin  is  brought  out  between  the  two  layers 
of  plastic. 

File  a  small  notch  in  the  bottom  piece 
to  accommodate  the  lug.  Before  cementing 
the  two  pieces  together  and  to  the  frame, 
make  each  hole  slightly  larger  than  the 
diameter  of  the  socket  pins.  This  will  allow 
for  expansion  when  the  plug  is  inserted. 

The  dial  is  made  of  2-1/4  in.  diameter 
1/8  in,  Plexiglas,  To  give  the  dial  a  rough 
edge,  for  good  thumb  traction,  I  heated  an 
old  gear  wheel  and  rigged  up  an  arrangement 
to  rotate  the  dial  against  it.  The  gear  should 
have  rather  coarse  teeth  and  rotate  with  the 
dial,  or  you  will  create  flat  spots. 

The  variable  capacitor  can  now  be 
mounted  in  the  case.  Position  it  so  that  the 
top  and  sides  of  the  dial  will  be  just  about 
even  with  the  edges  of  the  case. 


DECEMBER    1970 


45 


The  dial  marker  is  mounted  on  square 
aluminum  posts.  The  top  post  (2  in.  long) 
has  I  ^h  in.  of  its  length  filed  down  to  a  1/8 
in,  thickness  to  reduce  its  bulky  appear- 
ance. To  make  the  hairline,  scribe  a  line  in 
a  !4  in.  wide  piece  of  plastic  and  fUi  in  with 
a  ballpoint  pen. 

The  sensitivity  control  I  used  was 
already  prepared  for  the  knob  shown.  If 
you  don't  have  one  like  it,  use  a  dime-size 
pot  and  a  setscrew  knob.  Any  resistance 
from  5  to  10  \Xl  will  be  fine. 

Keystone  light  meters  are  available  from 
Olson  Electronics  in  a  package  of  five 
($3-99)  or  Transistors  Unlimited  Co,  (75^ 
each).  Some  modification  of  the  meter  is 
necessary-  Remove  the  light  ceil  and  series 

resistor-  Drill  two  holes,  spaced  14  in,  apart 
in  the  back  of  the  case  to  pass  4 --40 
machine  screws  for  easy  soldering,  make 
sure  the  heads  and  nuts  are  clean  and  free 
of  any  nickel  plating.  The  screws  should  be 
filed  even  with  nuts  in  order  to  make  room 
for  the  battery.  Solder  the  leads  from  the 


meter  movement  to  the  terminals,  but  be 
quick  because  the  plastic  case  tends  to  melt 
in  a  hurry  • 

Wiring  is  just  a  here-to-there  proposi- 
tion, requiring  no  terminal  boards  or  ter- 
minal lugs.  The  FET  is  soldered  in  place 
supported  by  its  own  leads.  With  reason- 
able care  you  should  not  damage  it.  A 
battery  holder  was  found  unnecessary; 
however,  it  is  a  good  idea  to  wrap  a  layer 
of  tape  or  stiff  fiber  paper  around  the 
battery  to  prevent  the  metal  case  from 
shorting  out  the  meter  terminals. 

Coil  Construction 

Figure  2  and  the  photo  give  the  neces- 
sary dimensions  and  show  the  parts  needed 
to  make  the  coil  forms.  The  battery  plugs 
are  listed  in  the  catalogs  to  fit  #482  and 
M3  batteries.  The  center  pin  should  be 
fUed  slightly  shorter  to  make  the  plug  seat 
evenly  in  the  socket.  While  you  are  at  it, 
file  the  nickel  plating  from  the  ends  of  all 
plug  prongs.  This  will  make  for  easier 
soldering- 


MelBT  is  held  against  the  front  panel  by  a  small  bracket.  The  FET  is  the  small  black  object  in  the  center. 


46 


73  MAGAZINE 


l-3/e  in  LG  COf*P£R 
STRIP  a  1/^  in.  WDE 


CLEAR  PLASTIC 

5/e  Dm 


RFC;  JOT  20  mm 

CLOSE  WOUND 
ON  t/B  ill   LO. 


MO  BATT  PLUG 


-I   SOT  CT  CLOSE  WOUND 
as  AWG 

J        IK 
^ — WS^ — 


<: 


G  CT   D 
6-15   MHi 


CTu 


\K       ^       '^ 

6ATE  DRAIN       CT 


32-85  MMi 


J8T  CT  CLOSEWOUNO  2eAWG 

(SPACED  1/4  tfj.  BETWEEN  TWO  WINDINGS) 


POWDERED -IRON  SLUS 

(1/4  It  f/Z  mj 

(5/8  X  \/Z  m  FOR  1.7-3  MHi) 


60T  fllOT   FOR  f  7-3  MHx) 
CLOSE  WOUft©  30  AWrtS  SILK 


SOT  (HOT  FOR  IJ-3  MHl) 


e  0  CT 

3      13-32  MHz 


G     CT    O 
2.9-6  MHi 
{(.7-5  MHil 


Fig.  2.  Coii  configurations  for  various  frequencies  of  resonance. 


Complete  coiJ  information  is  given  in 
Fig.  2.  However  a  little  explanation  may  be 
in  order.  The  irregular  method  of  winding 
the  §2  coil  is  necessary  to  reach  85  MHz 
and  still  maintain  oscUlation.  With  4  turns 
dose-wound  the  highest  was  too  low.  With 
the  4  turns  spaced ^  oscillation  ceased  at  the 
highest  frequency.  The  30  AWG  silk  wire 
was  taken  from  a  TV  flyback  transformer. 
The  resistors  in  the  centertap  of  the  last 
three  coils  improve  the  meter*s  sensitivity 
slightly.  They  are  mounted  right  next  to 
the  coil  winding.  With  a  slight  groove  filed 
inside  the  insulating  sleeve,  it  should  slip 
over  the  resistor. 

The  #6  coil  is  layer-wound  as  space 
permits  and  scrambled  wound  the  rest  of 
the  necessary  turns.  The  top  winding  of  all 
coiJs  should  end  near  the  very  edge  of  the 
coil  form.  This  will  make  for  easier 
coupling  to  a  tuned  circuit.  After  the  coils 
are  checked  out  the  insulating  sleeves  may 
be  glued  to  the  plug  base- 


Allow  the  glue  to  dry  for  several  days 
before  plugging  the  open  ends  of  each  coil 
with  a  small  cardboard  disk.  The  coils  are 
painted  with  colored  lacquers.  Colored 
paper  between  the  coU  and  the  insulating 
sleeve  will  probably  work  just  as  well. 
Calibration 

For  calibration  purposes^  you  will  need 
another  indicating  oscillator  or  dip  meter. 
Operate  it  in  the  diode  or  wavemeter  mode 
and  loosely  coupled  to  the  gate  dipper,  I 
calibrated  only  5  points  on  each  scale  plus 
any  ham  bands  which  appeared.  Remember 
the  dipper  is  not  a  frequency  meter  but 
something  to  get  you  in  the  ballpark. 

Conclusion 

The  little  gate  dipper  was  checked 
against  a  well  known  commercial  tube 
equivalent  and,  as  near  as  1  could  tell,  they 
were  just  about  even.  The  battery  should 
last  for  a  long  time  because  the  current 
drain  is  extremely  low. 

.  W5ETT  ■ 


,  I 


*  • 


DECEMBER    1970 


47 


Marlene  F.  Derfler 
804  48th  St.  S. 
Great  Falls  MT  S9401 


CLINKS  IN  A  Va' 

(A  LOW  PRESSURE  ARTICLE  FOR  WIVES) 


My  husband  is  a  builder:  No,  he 
doesn't  build  coffee  tables  or  book- 
shelves or  breakfast  nooks.  Instead  he 
builds  important  things  like  linear  ampli- 
fiers, grid  dippers,  calibrators,  and  all  those 
other  things  you  need  around  the  average 
American  home. 

They  say  that  Nature  abhors  a  vacuum. 
Well,  my  husband  does  too.  Most  of  the 
time  1  understand  his  drilliiig  and  pound- 
ing, his  screams  when  he  grabs  the  wrong 
end  of  a  hot  soldering  iron,  and  the 
horrible  whistle  that  wakes  up  the  baby 
and  indicates  he  is  getting  ''zero  beat,"  Our 
day  of  trial  comes,  however,  when  all  too 
frequently  it  becomes  necessary  to  vacuum 
the  house. 

We  have  a  shaggy  dog  that  sheds  and 
you  have  to  really  keep  after  the  clumps 
that  surround  him  whenever  he  stops  to 
scratch.  This  means  toting  out  the  vacuum 
nearly  every  day. 

My  part  of  the  great  vacuum  debate 
comes  when  I  start  hearing  the  pings, 
clanks,  and  pows  of  ^'things"  being  sucked 
into  my  little  vacuum *s  innards.  It  sounds 
disturbingly  like  bullets  ricocheting  among 
the  rocks  in  a  "B''  western  movie  and  it 
certainly  can*t  be  doing  my  vacuum  any 
good.  Investigation  long  ago  showed  these 
""tilings"  to  be  various  little  pieces  of 
plastic  stripped  off  the  ends  of  wires,  bits 
of  wire,  melted  glops  of  solder,  small  nuts 
and  bolts,  and  other  little  indescribable 
things  of  Ham  Husband  origin.  We  have 
agreed  that  he  should  keep  his  activities 
confined  to  the  spare  room  that  is  his 
*'shack,"  but  these  things  come  out  on  his 


shoes,  follow  like  a  dust  storm  in  his  wake, 
and  1  think  roll  out  by  themselves  in  the 
niglit.  Once,  when  1  shoved  a  handful  of 
'*clinks"  that  1  had  gathered  out  of  the 
vacuum  bag  under  his  nose,  he  peered  at  it, 
carefully  picked  out  the  little  nuts  and 
screws,  and  ran  back  to  his  shack 
mumbling  something  about  precious  hard- 
ware. 

There  is  another  side  to  the  story  to  be 
sure.  1  usually  just  get  the  vacuum  started 
and  have  suffered  through  the  initial  ten  or 
twenty  internal  ricochets  when  he  comes 
tearing  out  of  that  dark  hole,  often  with 
headphones  strung  around  his  neck, 
striving  to  be  heard  over  the  combmed 
noise  of  the  vacuum  motor  and  a  sound 
like  ball-bearing  Ping  Pong,  After  pulling 
the  plug  out  of  the  wall  (a  move  which 
someday  may  be  fatal  because  he  wired  it 
himself),  lie  finally  gets  across  the  point 
that  my  vacuum  is  making  a  horrible  noise 
in  his  radio.  I  suppress  the  urge  to  ask  him 
why  he  doesn't  talk  to  this  horrible  noise 
just  like  he  does  to  all  the  others  and 
instead  1  ask.  the  same  question  that  I 
always  ask  him. 

*is  there  any  way  to  cure  our  mutual 
noises  without  my  giving  up  vacuuming 
and  you  giving  up  ham  radio?''  At  the 
mention  of  the  latter  sacrilege  he  usually 
turns  paler  and  retreats  a  few  feet  toward 
the  comforting  smell  of  burning  solder.  It 
is  hard  for  him  to  turn  any  paler  because 
the  only  sun  he  ever  gets  is  when  he  works 
on  antennas  during  the  winter  and  at  an 
occasional  hamfest  in  the  summer,  but  the 
burning  solder  smell  is  always  around. 


48 


73  MAGAZINE 


r 


Normally  then,  we  just  stare  at  each 
other,  both  of  us  silently  remembering  the 
time  he  did  try  to  do  something  about  his 
noise.  On  thai  occasion  he  had  grabbed  up 
my  vacuum  and  carried  it  off  to  his  lair 
where  he  gutted  it  and  added  little  round 
things  to  its  insides  with  his  ever-ready 
soldering  iron.  In  a  way  he  did  temporarily 
solve  both  of  our  problems  because  when 
he  plugged  it  in  lie  l>lew  the  last  fuse  we 
had  in  the  house.  I  wouldn't  let  him 
replace  the  fuse  with  a  piece  of  solder,  so 
he  tramped  out  to  the  store  muttering 
someLliing  about  "ac  working  voltages." 

I  havcMiH  let  him  touch  my  vacuum 
since,  of  course,  but  I  ask  him  the  same 
question  each  time  just  to  bring  him  back 
to  liis  senses.  He  usually  is  torn  for  a 
moment  or  two,  contemplating  an  ocean  of  ' 
dog  hair  on  the  one  hand  and  a  normal  hfe 
on  the  other.  Remembering  that  dog  hair 
gets  into  the  fan  on  his  linear  amplifier,  he 
usually  compromises  at  this  point  and  says, 
"QRX  one  ..."  I  take  the  minute  to  pick 
up  whatever  bits  and  pieces  and  "things"  1 
can  see  that  he  carried  out  with  him  on  his 
last  excursion.  When  i  start  vacuuming 
again  after  this  mysterious  ritual  of  *'QRX" 
I  know  111  be  greeted  by  a  sound  worse 
than  a  trio  of  two-year-olds  let  loose  to 
play  with  all  the  kitchen  pots  and  pans. 

All  this  that  1  have  been  telling  you  was 
true    until   just    the   other   day.   On   that 
particular  fateful  day  we  had  gone  through 
our  usual  routine  and  1  had  asked  him  the 
usual    question.    This   time   to  my   amaze- 
ment he  said,  **You  know,  sweetie,  maybe 
you're   right.    1    should   spend    more   time 
with  you  instead  of  with  my  projects  and 
radio.  I  could  help  you  around  the  house. 
We  could  go  out  more,  meet  new  people.  1 
couldn't    get    much    money    for    all    that 
homebrew    gear,    but    1    could    give   it    to 
somebody  who  could  use  it  and  then  you 
wouldn't   have   any    more   clinks  in  your 
vacuum  cleaner.** 

That  day  1  was  so  happy!  We  closed  the 
hamshack  door  and  right  then  he  started  to 
help  me  around  the  house.  The  first  Ihiiig 
he  did  to  help  was  to  shake  out  the  rugs. 
The  same  eyes  that  can  spot  the  latest 
transistor  in  a  radio  store  window  from  a 
moving  car  at  six  hundred  feet  didn't  see 


r 


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I 


DECEMBER    1970 


49 


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I 


my  hand  washables  hanging  on  the  line 
upwind,  but  he  was  helping!  The  second 
thing  he  did  to  help  was  to  put  the  dark 
things  in  the  washer  for  me.  He  even 
included  the  skirt  to  my  dark  wool  suit 
which  was  in  the  pile  going  to  the  cleaners. 
He  said  he  wanted  to  make  a  full  load. 

That  night  we  got  a  babysitter  and  went 
out  to  dinner.  He  paid  ten  dollars,  for  our 
steak  dinner,  and  then  my  reformed  hus- 
band suggested  that  we  go  somewhere  else 
for  an  after-dinner  drink.  Dazzled  by  all 
the  attention,  1  happily  agreed.  We  had  just 
gotten  settled  with  our  dollar-fifty  after- 
dinner  drinks  when  who  should  pass  by  but 
his  old  high  school  girlfriend  and  her 
heavy-handed,  shifty -eyed  husband. 

After  we  had  paid  the  babysitter  her 
ransom  and  my  husband  was  taking  her 
lionic,  I  began  to  tiiink.  ''It  would  be  nice 
to  have  help  with  the  housework,  but  the 
experience  might  take  years  off  my  life. 
What  would  he  do  when  he  found  that 
doing  chores  together  really  isn't  much 
fun?  Would  he  go  to  the  bur  wiUi  the  boys 
and  maybe  run  into  that  floozie  without 
her  heavy-handed  husband?  The  ham 
friends  that  come  over  now  are  really  quite 
polite,  even  when  they  are  loaded  down 
with  all  that  stuff  they  carry  in  and  out.  At 
least  now  he's  around  if  1  need  him.  That 
smile  on  his  face  when  he  shows  me  his 
latest  contraption  does  bring  a  lot  of  joy 
into  the  house  -  .  •*' 

The  next  day  we  agreed  that  we  should 
go  into  the  hamshack  together  and  start  to 
clean  it  out.  It  was  just  by  chance,  of 
course,  that  I  bumped  against  the  receiver 
and  turned  it  on.  When  that  station  came 
on  calling  CQ  I  was  only  curious  when  1 
asked,  "Can  he  hear  you  as  well  as  you 
hear  him?"  It  was  with  a  great  deal  of 
pleasure  that  I  saw  his  eyes  flash  with  an 
inner  determination  not  to  weaken,  which 
died  when  flooded  out  by  the  desire  to  get 
just  one  more  signal  report. 

The  smell  of  burning  solder  fills  the  air 
around     our    house.    The    clinks    in    the 

vacuum  cleaner  are  still  there,  but  some- 
how they  mean  something  different  to  me 
now  than  before.  They  mean  I  have  a  ham 
at  home  that  loves  me. 

.  .  .  Derfler  ■ 


50 


73  MAGAZINE 


YOUR 


Norman  Ralph  W4AYI/5 

124  Teresa  Drive 
Greenville  MS  38701 


After  building  a  grounded-grid  linear 
using  four  811  As  and  modifying  it, 
improving  it^  ctc.^  I  decided  to  build  a 
linear  that  would  perhaps  reflect  some  of 
the  knowledge  and  experience  I  had 
learned. 

Much  thought  was  given  to  what  type  of 
tube  or  tubes  would  be  used.  The  new 
3-5 00 Z  was  chosen  for  several  reasons. 
First,  a  tube  requiring  plate  voltages  in  the 
2—3  kV  range  was  to  be  desired  to  keep 
the  plate  tuning  capacitor  to  a  reasonable 
size  (250  pF).  Secondly,  a  tube  with  a  large 
plate  dissipation  was  wanted  to  give  a 
much  larger  margin  of  safety  than  was 
available  with  the  81  lAs.  The  3-5  OOZ  has  a 
plate  dissipation  of  almost  twice  that  of 
four  81 1  As,  Third,  the  low  output  capaci- 
tance of  the  3-5 OOZ  enables  it  to  be  used  at 
higher  frequencies  much  easier.  Fourth,  the 
3-5 OOZ  efficiency  range  makes  it  very 
versatile.  Output  ranges  from  7 SOW  out 
with  IJ  kW  input  at  3  kV  to  500W  out 
with  800W  input  at  2  kV,  And  finally,  the 
intermodulation  products  are  very  low 
with  the  3-500Z  as  with  other  zero-bias 
triodes  designed  for  grounded-grid  class  B 
service.  Here  is  a  table  showing  typical 
operation  of  the  3-500Z. 

Dc  plate  voltage 
Zero  $pg.  p(,  current 
single  tons  pi.  current 
singfe  tone  grid  cur, 
PEP  input  povver 
PEP  useful  output  pwr 
Resonant  load  imped 
Cathode  mput  imped 
I  ntermodu  Nation  prod. 

The  schematic  diagram  of  the  amplifier 
(Fig,    1)   is   pretty   much  self-explanatory 


3.0 

23    3,0kV 

160 

130 

95   mA 

370 

400 

400   mA 

115 

120 

130  mA 

1110 

1000 

800  W 

750 

600 

500  W 

5000 

3450 

2750  fl 

115 

100 

fOO  U 

-30 

-33 

-38  dB 
C3rd  order) 

and  there  is  not  very  much  new  about  the 
design.  It  follows  what  is  in  the  handboolc 
and  other  publications.  A  high-capacitance 
tuned  input  circuit  was  used  to  obtain 
greatest  linearity.  Without  the  tuned  input 
circuit  the  exciter  sees  a  low  load  imped- 
ance over  part  of  the  rf  cycle  and  a  very 
high  impedance  over  the  remainder  of  the 
cycle.  Consequently,  the  waveform  suffers. 
Also  with  an  untuned  input  the  rf  plate 
current  return  path  to  the  cathode  must 
travel  the  outside  shield  of  the  coax  to  the 
exciter  plate  circuit  and  then  back  the 
center  conductor  to  the  cathode.  This  can 
result  in  high  intermodulation  distortion. 
With  the  tuned  input  circuit  these  prob- 
lems are  solved  as  the  tank  circuit  provides 


Inside  the  3'SOOZ  linear  amplifier, 

a  **flywheel  effect"  for  good  waveform  and 
a  short  rf  return  to  the  cathode. 

Many  of  the  components  used  were 
obtained  from  suppliers  advertising  in  73. 
Relay  Kl  in  the  rf  section  is  included  to 
enable  the  linear  to  be  switched  in  and  out 
of  the  circuit  with  the  plate  voltage  switch 
S2. 


I 


DECEMBER    1970 


51 


9T  NO   14 


500 


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tj 


L3 


30  llV 


.C2 


3  kV 

-HFC 

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RIFItAR  ^CLfDSEWOUffD  ON 

WlNf^M  KERAWfC  «gD 

ZO-30T  NO   lO  1»  "rfl.  OlA  1  9  ifl 

FORMVAfiE  mm^ 

FERRm   1*00  '^^■'^' 


O  S4 


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/77 


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IIOQ 


2. a  mH 


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HF  our 


Al  HA.  OlA  1  9 
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4   rfn  TAPPED 
P<W?  EACH  SAND 


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_L^  Af4D  L  a.  eg  AMO  CB 


nCACTANCE  OF  S5Q^^ -CI 
riEACMMCt  OF  30r-^C2 
RCACTANCf  OF  Z?3[2-L2.  Ll 


C£  '  teO  ||F  AT  a  5  HHf 
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49  Df  AT  L4  MHt 
30  pF  AT  21  IMv 
2?  if"  AT  £9   l«if 

LS-tZj9  »H  «T  3  5  iMi 
«29  VH  AT  7  2  HHi 

312  j^  AT  14  ie4t 

2  ft  ^  AT  ?i  HHii 


C3-  IfiOO  pF  AT  3.5  MHi 
790  pF  AT  t  2  Mrti: 
JTft  pf  AT  t*  WHi 
250  pF  AT  21  UHi 
190  pFAT    M  UHI 

L2-tA  l#4  AT  28  MHt 


/W 


01 


J 


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RFC 

2J3  mH 
900  ifeA 

PIMHMI 


20M 

torn 


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o 


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1LAI««(lT 


TO 

lis.  VAC   l-PWl? 

SUP 
COMMON 


13  V*C 


Fig.  I.  Schematic  of  the  3-500Z  linear  amplifier. 
Coil  data  is  shown  on  the  table  insert. 


\ 


Tube  Socket 

The  tithe  socket  is  home-made.  I  cut  a  3 
in.  round  hole  in  the  chassis  for  the  tube 
socket.  The  socket  consists  of  a  4  in,  piece 
of  Plexiglas  with  a  2  in,  hole  cut  in  it  (Fig. 
2).  Five  large  tinned  forked  terminal  lugs 
were  purchased  from  a  local  automotive 
store.  These  could  be  made  to  fit  the  pins 
of  the  3-500Z  by  springing  the  part  of  the 
Uig  where  the  wire  normally  would  be 
inserted.  J  bent  the  forked  part  at  a  right 
angle  and  bolted  to  the  Plexiglas  in  posi- 
tion to  take  the  pins  of  the  tube. 

The  part  of  the  terminal  lug  taking  the 
tube  pins  protrudes  out  and  down  into  the 
2  in*  hole  and  air  can  flow  freely  around  all 
the  pins.  Short  wide  copper  straps  were  run 
from  the  forked  part  of  the  terminal  lugs 
to  the  chassis  on  the  three  grid  pins  of  the 
tube  when  the  Plexiglas  Is  mounted  under 
the  3  in.  hole  in  the  chassis.  This  not  only 
effectively  grounds  the  grid  pins,  but  also 
provides  a  heatsink  for  them. 

I  used  an  SK-406  chimney,  but  you 
could  use  a  chimney  from  a  Coleman 
double  mantle  lantern.  The  lantern  chim- 
ney sells  for  under  $2,  which  is  quite  a 
savings  over  the  SK-406,  However,  as  the 
sides  of  the  lantern  chimney  are  straiglit, 
they  do  not  deflect  the  air  flow  past  the 
plate    heat   dissipating  connector,   so   the 


tube  should  be  observed  closely  that  it 
doesn't  overheat.  A  suggested  remedy  for 
this  disadvantage  of  the  lantern  chimney 
would  be  to  cement  a  ring-shaped  piece  of 
Plexiglas  to  one  end  of  the  chimney.  The 
diameter  would  be  slightly  larger  than  the 
diameter  of  the  chimney  and  the  center 
hole  would  be  2.5  in. 

The  HR-6  plate  heat  dissipating  con- 
nector must  be  purchased  separately  and 
lists  for  $2.20,  but  a  supplier  that  adver- 
tises in  73  has  them  listed  in  his  current 
catalog  for  less  than  a  dollar. 


PUE^ItLAS  SQUAI^ 

4  in 


3  is.  CMA  HOLf  ftCOaJR^ 
m  CHASSIS 


TMKI  CHA&&4   STRAP 


S^PADE  LLi(*  BENT 
U3*  AT  >0' 


COPPErt  STftAP 


Fig.  2,  Layout   and  plans  for  the  do-it-yourself 

tube  socket. 


52 


73  MAGAZINE 


n 


AMERICAN  MADE 


Mobile  2  Meter  FM  Transceiver 

Here  is  what  the  2  meter,  FM 
Ham  World  has  been  asking  for. 

Specifications:  90  day  warranty 


RECEIVER 

The  HR-2  receiver  is  a  double  conversion, 
superhetrodyne  with  highly  selective  ce- 
ramic filter. 

Fr^uency  Range...  144-14^  MHz 
Sensitivity,.„*«.«__J).35/iv  (nom.)  20DB  Quieting 


Selectivity ,..^_. 

Audio  Output 
{3-4  ii  Speaker) 


,6DB  Down   ±   16 KC 
50 DB  Down   ±  32KC 


Channels..„<„»„, 


.  .3  Watts  10%  Distortion 
5  Watts  l\^3ximum 

„_6  Crystal  controlled  with 
provision  for  adding  an 
additional  6  channefs 

f.F.   Frequencfes..-^I0.7  MHz  &  455KH2 


TRANSMITTER 

The  HR-2  transmitter  uses  phase  modula- 
tion for  the  ultimate  in  carrier  stabiltty. 
Built  in  SWR  load  mismatch  circuitry 
provides  protection  ajgainst  open  and 
shorted  antenna  conditions. 


Frequency  Ra 
Power  Output 
Modulation... 


Deviation*., 


Microphone. 
Channels,,.,,, 


nge„„144-148  MHz 

...„„,.  10  Watts  (min*)  @  13.6  VOC 

.phase  Modulation  with 
automatic  deviation  limiting 

..Automatic  Limiting  with  in- 
ternal adjustments  from 
O-^ISKC  deviation 

„Plug-in,  hand  held,  high  Z 
Ceramic  supplied 

.,6  Crystal  controfied  with 
Individual    trimmer    capacj'- 
tors  for  Frequency  netting 


tA 


O 


m 
i(/i 


I 


to 

a 

m 
o 


m 


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CD 


P. 


GENERAL 

Power  Requirements  13,6  Volts  (nominal) 

Receive  (Squelched), 180  MA- 

Receive  (Max.  audio 
output) . 800  MA. 

Transmit„*««,.,» .2*5  Amps  (max,) 


STANDARD  EQUIPMENT 

Built-rn  4''  Speaker 
Mobile  Mounting  Bracket 
SO-239  Antenna  Connector  Socket 
T  &  R  Crystals  for  146.94  MHz 
PTT  Ceramic  Mike 


^ 


only  «22900 


Amateur 
Net 


C^-C^Cy      ELECTRONICS,  INC. 

i  7900  Pendleton  Pike,  Indianapolis,  Indiana  46226 


CO 


o 

o 

o 

3 

'a 
o 


I 


1 


02 


4000  PIV 
t.5  AMR 


T4QO0  PIV 
^1.5  AMP 


ALL  FILTER  CAPAClTOftS 
50O  |4^/  3IO  VOC  EACH 


ALL  BLEEOER  RESISTORS 
2-IOOK,  2W  CAftSON 
IN  SERES 


500K 


^.0-1  ITT  A 

*)CAL(BRATED 
0-5000  VOLTS 


P29 


r 


B- 
115  VAC 

COMMON 


Fig,  3.  High  voltage  power  supply. 


Power  Supply 

For  the  power  supply  (Fig,  3)  I  used  the 
filament  transformer  from  an  old  TV.  I 
removed  the  shell  from  the  transformer 
and  discovered  the  filament  windings 
wound  on  top  of  the  primary  with  the 
secondary  HV  wound  on  the  bottom  next 
to  the  core.  I  removed  the  filament  wind- 
ings, counting  the  5V  windings,  end  then 
wound  a  new  filament  winding  using  the 
10-gage  wire  1  used  on  the  filament  choke, 
I  taped  up  the  HV  secondary  leads  and 
they  are  not  being  used.  The  voltage 
checked  out  at  5 -25V  without  the  tube  in 
the  socket  and  5V  with  the  tube  in  the 
socket  and  Ut.  The  shell  was  replaced  on 
the  transformer  for  maximum  shielding.  In 
use,  the  transformer  stays  cool  at  all  times. 

The  pi-network  is  designed  around  a 
reactance  of  275n  in  the  coil,  25012  in  the 
tuning  capacitor,  and  300  in  the  loading 
capacitor.  This  will  give  you  a  Q  of  20  if 


you  use  a  plate  voltage  of  3  kV,  If  your 
plate  voltage  should  only  be  2  kV  or  you 
should  later  add  a  second  tube  your  Q 
would  still  be  a  respectable  10.  At  2.5  kV 
the  Q  is  almost  14.  Actual  values  of  L  and 
C  are  given  in  the  chart  on  the  schematic. 

All  the  metering  is  done  in  the  negative 
lead  of  the  cathode  circuit.  This  keeps  high 
voltage  off  them  and  allows  the  grids  to  be 
grounded  direct.  The  panel  meters  axe 
small  imported  ones  that  sell  for  less  than 
$5  each.  The  voltmeter  in  the  power 
supply  could  be  mounted  in  the  rf  section 
if  desired. 

The  power  supply  is  of  standard  design 
with  a  full-wave  voltage  doubler  system 
that  gives  an  approximate  no  load  voltage 
of  2,8  times  the  secondary.  Voltage  regula- 
tion will  depend  on  transformer  capabili- 
ties and  house  line  voltage  regulation  as 
well  as  the  output  capacitance  of  the  filter. 
The  filter  capacitors  used  here  were  pur- 


54 


73  MAGAZINE 


chased  from  an  ad  in  73  for  $1  each  and 
provide  over  40  ^F  of  filtering. 

A  relay  and  250  20W  resistor  was  put 
in  the  primary  circuit  of  the  transformer  as 
shown  in  the  schematic  to  protect  the 
rectifiers  from  the  high  surge  of  current 
that  occurs  when  the  large  filter  capacitors 
are  charging.  The  other  relay  was  installed 
in  the  power  supply  to  keep  the  control 
wiring  to  the  rf  section  in  a  small  cable  of 
20-gage  wire. 

The  power  supply  is  a  separate  unit.  It  is 
in  a  well  ventilated ,  completely  enclosed 
box  that  is  kept  under  the  operating  bench. 

Finishing  Touches 

The  rf  section  is  enclosed  in  a  home- 
made  cabinet.    I    had   a  local  sheet-metal 

shop  cut  and  bend  the  aluminum  to  my 
specifications.  I  painted  the  panel  a  light 
gray  and  the  bottom  and  top  cover  are 
painted  black.  The  tube  and  input  circuit 
are  moainted  on  one  side  of  the  cabinet, 
and  the  pi-network  and  filament  trans- 
former are  in  the  other  half  of  the  cabinet. 
An  access  panel  was  cut  in  the  bottom 
plate  under  the  chassis  and  a  Roton  muffin 
fan  mounted  on  the  cover  plate.  Rubber 
feet  were  mounted  on  the  bottom  to  let  air 
under  the  cabinet- 
There  you  have  it  —  a  linear  that  no 
longer  looks  like  a  "Rube  Goldberg" 
special  and  is  pleasing  enough  to  the  eye  to 
be  placed  alongside  your  exciter.  There  is, 
by  the  way,  enough  room  in  the  rf  section 
for  a  second  3-5 OOZ  if  you  have  power 
supply  enougli  to  handle  it. 

,  .  .  W4AYI/5  ■ 


^«. 


JVIANUFACTURERS, 


SPEC   SHEETS  ^  INSTRUCTION   BOOKS 

While  our  typesetting  and  art  departments 
are  not  exactly  underburdened,  they  are  not  all 
that  flat  out  either-  Neither  is  our  printing 
departnnent,  so  if  you  need  any  spec  sheets 
made  up  or  instruction  booklets  for  your 
equipment,  why  not  get  in  touch  with  us  for  a 
quote.  We  have  the  technical  department  to 
write  it,  edit  it,  set  it  in  type,  take  pictures  of 
the  equipment,  lay  out  the  booklet  or  spec 
sheet,  paste  it  up,  and  print  it.  After  aM,  we 
turn  out  two  rather  good  sized  magazines  a 
month  plus  a  lot  of  brochures,  letters,  pro- 
motions, and  even  a  fair  amount  of  job  work 
for  our  locaHty. 

Perhaps  you  need  counter  cards,  posters, 
bumper  stickers,  or  almost  anything  else  that  is 
printed  or  silk-screened? 

73  Magazine  •Peterborough  NH  03458 


NOW! 


from 


ROSS  AND  WHITE  COMPANY 

ELECTRONICS 

SOLID  STATE 

TONE  BURST  ENCODERS 

(TO  THE  FREQUENCIES  OF  YOUR  CHOICE) 


MODEL  TE2 
2  tone 

Factory  preset, 
only 
S29-95 
postage  paid. 


MODEL  TE-5 
5  channel  model 
Factory  preset, 
only 
S39.95 
postage  paid. 


GUARANTEED  FOR  ONE  YEAR! 

Use  it  for  10  days,  if  not  completely 

satisfied  return  for  a  full  refund. 

•  Easy  to  install,  3  wire  hookup, 
attaching  bracket  included  for  car  or  home. 

•  Operates  from  a  single  factory  supplied  internaf 
9  volt  battery. 

•  All  frequencies  factory  preset.  Can  be  field 
adjusted  from  1600  to  2800  cycles.  Other 
frequencies  on  special  order. 

•  Nominaf  0.5  sec-  tone  burst  length. 

•  American  made  commercial  grade  components 
on  glass  epoxy  PC  board  for  maximum 

reliability. 


ROSS  AND  WHITE  CO.,  Electronics  Dept,  73-12 

50  West  Dundee  Rd.,  Wheeling,  ML  60090 


Gentlemen: 
Send  me  model. 

Xcvr  make 


.tone  burst  encoder 


Model. 


Check  or  money  order  enclosed.   Please  set 
frequencies  for 


Send  additional  information.  Check  Q 
Name 


Address 


City 


State 


Zip 


DECEMBER    1970 


55 


The  HT-2  Mark  II,  now  with  a  new 
and  improved  transmitter,  is  the 
only  2  meter  FM  walkie-talkie 
built  for  the  amateur.  It  features 
an  extra-sensitive  receiver  with 
crystal  and  mechanical  filters 
for  excellent  selectivity,  and  1.6- 
2  watts  out  with  very  good  audio 
quality.  The  ideal  rig  for  re- 
peater operation  —  in  town  or 
hilltopprng!  Comes  with  many 
i6xxr3s« 

Amateur  Net    $269.95 


One  year  warranty  —  atl  products. 


It's  undoubtedly  the  finest  amateur  2  meter  FM 
transceiver  on  the  market.  This  unit  has  better  than 
0.4  fiM  sensitivity,  uses  FETs,  ICs,  and  ceramic  fil- 
ters and,  as  a  result,  the  receiver  audio  is  superb. 
Rated  at  10+  watts  out  (often  delivers  12-15).  Has 
6  channels,  transmit  and  receive.*  The  APC  (auto- 
matic protection  circuit]  prevents  PA  failure  due  to 
open,  shorted  or  mismatched  antenna.  Great  for 
mobile  applications  —  it's  so  small  and  compact. 
The  IC-2F  is  a  beauty! 

Amateur  Net    $349.95 
IC-3P  49.95 

^Available  soon  —  concentric  6  position  switch  alfowing 

36  channel  combinations! 


I 


8ut  if  fie  doesn't,  surprise  him  with  one  of  our  fine  2  meter 
all  solid-state  FM  transceivers  or  that  exciting  new  "REDHEAD  " 

the  AS-2HG  2  meter  gain  antenna. 


'I 


You've  gotta  see 
THE  REDHEAD 


The  AS-2HG  two  meter  FM  3.4  db  gain  groundplane 
antenna  is  the  newest  addition  to  the  Varitronlcs 
quality  line.  This  commercial  quality  antenna  is 
built  of  heavy  gauge  aluminum  tubing  and  is  adjust- 
able for  minimum  VSWR  over  the  entire  2  meter 
band.  Rated  at  500  watts,  it's  easy  to  assemble  and 
all  mounting  hardware  Is  included. 

Amateur  Net    $18.95 


A  very  happy  holiday  season  to  all  of  you  from  all  of  us. 

Varitronics  Incorporated 

Arizona  Interstate  Industrial  Center 
2321  East  University  Drive,  P.O.  Box  20665  •  Phoenix,  Arizona  85036 


Amateur  radio  enthusiasts  have  been  using  surplus  V.H.F.  -  FM  equipment 

for  years,  but  until  recently  most  of  this  equipment  was  not  specifically 

designed  for  amateur  use,  and  was  very  expensive.  Standard  Radio 

Corporation,*  one  of  the  largest  manufacturers  of  electronic  equipment  in 

the  world,  has  applied  solid  state  technology  to  develop  a  professional 

quality  2-meter  system  specifically  for  amateur  use. 


The  SR-C806MA  is  most  frequently  used  as  a  mobile  unit;  however,  it 
also  makes  an  ideal,  low  cost  base  station  unit  when  used  in  conj unction 

with  the  A.C.  power  supply  accessory. 

The  popularity  of  2-meter  FM  amateur  communications  is  rapidly  growing. 
In  most  metropolitan  areas  of  the  country  146.94  MHz  is  extensively 

monitored,  and  open  repeaters  make  it  possible  to  maintain 

communications  over  wide  areas  of  the  country.  Standard's  new 

professional  quality  2-meter  system  now  makes  it  possible  for  you  to  enjoy 

the  fun  of  amateur  mobile  communication  in  your  car  for  just  $335,00, 


*  Manufacturing  division  of  Standard  Communications  Corp. 


Dealer  Inquiries  Invited : 


Erickson  Electronics 

4657  N.  Ravenswood 

Chicago,  III  60640 

312-334-3200 

Artie  Specialty 

2252  Dixie  Highway 

Ponliac,  Mich.  48055 

313-335-4505 


Henry  Radio 

11240  W.Olympic  Blvd. 

Los  Angeles,  Ca.  90064 

213-272-0871 

L. A. Amateur  Radio  Sales 

23004  Crenshaw 

Torrance,  Ca.  90505 

213-534-4456 


Export  Agents: 

Mint  home  International, 
2200  Shames  Drive 
West  bury  Long  Island, 

N,Y-  11590 
516-334-3304 


^ 


GENERAL 

Freq,  Range  —  143  to  149 

MHz 

12  channels  in  2  MHz  spread 

Supply  voltage  —  11  to  16 

VDC, 

1 3. 8VDC  nominal 

Current  Consumption — ^.15 
amp  receive  standby,  2.4  amp 
transmit 

Polarity  of  supply  voltage  — 
Negative  ground 

Number  of  channels^  12- 
S applied  with  4  channels 

1)  146.94  MHzTx  and 
Rx  (national  calling 
channel) 

2)  146.34  Tx— 146.76 
Rx  (repeater  channel) 

146.20  Tx— 146.80 


3) 


4) 


(repeater  channel) 

146  J4Tx— 146.94 
Rx  (repeater  channel) 


Microphone  —  Dynamic 
type  with  retractable 
neoprene  cord 

Dimensions  —  6%  "w  x 
2^^"h  X  9^8  "d 

Weight  —  4¥i  lbs,  max. 

Frequency  stability ^ — .001% 
(— 10to+60°C) 

TRANSMITTER 

RF  power  output  —  .8  or 
10  watts 

Audio  response hi  — 3 

dB  of  6  dB /octave 
pre-emphasis 

Output  impedance  —  50 
ohms  nominal 

Deviation  —  Internally 

adjustable  to  ±  10  kHz  min, 

factory  set  to  ±7  kHz 

Spurious  and  harmonic 

attenuation  —  50dB  below 

the  carrier  power  level 

Audio  roll  off  above  3  kHz 
—  12  dB/octave 

Type  of  modulator  —  Phase 


STANDARD 
COMMUNICATION  CORR 

P.O.Box  325.  Wflmington, 
Calif.  90744  (213)  775-6284 


RECEIVER 

Sensitivity  —  .35  or  less 
microvolts  for  20  dB  quieting 

Squelch  sensitivity  — 
Threshold  ~  ,2  microvolts 

or  less 

Maximum  (tight)  — 

Between  20  dB  quieting 

sensitivity  and  20  dB  quieting 

plus  10  dB 

Deviation  acceptance  — 
Up  to  ±  1 5  kHz  deviation 

Spurious  and  image 
attenuation  —  50  dB  below 
the  desired  signal  threshold 

sensitivity 

Adjacent  channel  selectivity 

(30  kHz  channels)  —  60  dB 

attenuation  of  adjacent 

channel 

Type  of  receiver  — 

Dual  conversion 

superhetrodyne 

Audio  output  —  2  watts 

minimum 

Audio  distortion —  10% 
maximum  at  1  watt  output 

$335.00 
(complete  as  shown  with 
microphone  and  built-in 

speaker) 


-1 


SWITCH 

SOLID 


^  F  ET  front  end  Por  low  noise  and  low  cross  mod. 
^0,5U  V  for20dbof  quieting  or  better 

►  rf  Power  output  10  WATTS  rnini mum 
^2channela  installed  CH.1  34/94  CIH.2    94/94 

AMATEUR  NET  $249.96 


RECEIVER  PC  BOARD 
0.5u  V  I  20db  quieting  ) 

94  installed 
3.5X  7"x  1 " 

«  68.50 


PC    BD. 


TELECOMM 


TRANSMITTER 
O.BWmin. 

34,  94  installed 

3  b'x  7"x  1" 

♦  79.10 


POWER  AMPLIFIER 
Q5Win  lOWoutmin. 
1.6x2"x7r 

#86.00 


ELECTRONICS 


ROBOX4ei   CUPERTINO,  CA.  95014 


The  new  2K 


6^ 


IT'S  EVEN  BETTER  THAN  THE  2K-3. 


JJ 


STILL  all  the  famous  2K-3  features: 

Rugged   Construction  —  Built  to   last 
a  lifetime. 

Reliable  Performance  —  When  you  call 
you  QSO. 

Heavy  Duty  Components — Our  power 
transformer  alone  weighs   more  than 

some  amplifiers. 

Conservatively  Rated  —  Loafs  at  full 

legal  power. 

Floor  Console  or  Desk  Model. 

PLUS  these  additional  features; 

Modern   Styling  —    Keyed    to   a   new 
decade. 

Tilted  RF  Deck  for  Easier  Operation  — 
Looks  you  right  in  the  eye. 
Mechanically  Refined  —  Pride  of  own- 
ership is  part  of  the  package. 
Brushed  Aluminum  Panel  and  —  Mod- 
ern Square  Meters  (Amplifiers  can  be 
beautiful). 
Recessed  Power  Supply  Pedestal. 


/ 


/ 


11240  W.  Olympic  Blvd.,  Los  Angeles,  Calif.  90064 

213/4776701 
931  N.  Euclid,  Anaheim,  Calif.  92801  714/772-9200 
Butler,  Missouri  64730  816/679-3127 


STILL  a  superb  value  at . .  *  $795.00 

If  you  are  one  of  the  more  than  3000  happy  2K 
owners,  trade  up  to  the  new  2K-4,  If  you  are  not 
one  of  the  group  now  is  the  time  to  join.  For  full 
information  write: 


Henry  Radio  has  representatives  in  different 
areas  of  ttie  U.S.  to  simplify  ordering  for 

those  living  near  one.  Or  you  can  order 
direct  and  we  will  ship . , .  across  the  street 
or  around  the  world.  CatI  or  write  for 
specifications  and  terms. 

New  York  area:  John  Richardt,  W2W1Y  (201)  637-4107 
Houston  area:  Jan  Carman  W5SBX  (713)  464  0419 


>4//^«j^#^».   AA*f*t^^A,  ^^J  ^^*«*«^*^;^/  *.r^^r     The  3K  amplifier  IS  now  available  for  continuous 

Attention.  Military  and  commercial  users,  ^^^^  ^-^^  ^^^^^  pttty  and  extra  power  ssB 

operation.  $895.00  F.O.B.  Los  Angeles,  Calif. 


i 


w^ 


IV 


CiflJ'iS 


UNHlttWV 


rt^tnor 


our  unFistmas  Shopping 
with  73  Gift  Subscriptions. . . 
You'll  be  giving  something 
that  will  be  appreciated  and 

^used  al(  year  long.PLUS:  73 
will  send  a  special  Christmas 
gift  card  in  your  name  along 
with  the  January  issue  -  in 
plenty  of  time  for  Christmas. 
And  the  Special  Christmas 
Price  will  make  it  easier  than 

g  ever  for  you  to  remember  all 
your  ham  friends.  The  first 

Wbscription  is  $6.  The  sec-4 

V  ond  is  $5.  Additional  gifts  aiV 
m     only  $4  each.      


^ 


k 


01?  out 


I  4 


JT^: 


ir 


lT*  >" 


^> 


v 


\-\ 


i¥  i  I 


hmu 


Sent  by. 


.Call 


Address 


City/State 


Enclosed  $. 
Bill  me.. 


-ZIP. 


.for 


_subscriptions. 
New Renew  (in- 


clude address  label) 


Vi 


Name/Ca 


Address 


1 


lV; 


A 


Ctty/Stata 


Renewal 


ZIP. 


Don't  know 


T    - 


I 


iV^ 


$6  for  this  gift 


fc:* 


Name/Call, 


Address 


City/State. 


ZIP. 


New. 


Renewal Don't  know 


$5    for   this  gift   when   accompanied  by 
the  first  six  dollar  sub. 


\V 


A 


^^PJ^ 


Name/Call. 


Address. 


City /State. 


New_ 


ZIP. 


Renewal 


Don't  knoy\i  [^^-'^ 


$4    for    this    gift    accompanied    by    the 
first  and  second  gift  subs. 


j^ 


Name/Call. 


Address 


City/State. 
New. 


2IP_ 


Renewal Don't  know 


i^ 


$4  for  this  gift  accompanied  by  the  first, 
second,  and  perhaps  third  gift  subs* 


Helpful  Hanna  says: 

If  you  don't  Want  to  cut  up  your 
nnagazine,  Make  a  reasonable  fac- 
imife  of  a  coupon  ,  filf  out  and  nnaiL 


y^^^ 


Send  to   73   Magazine,   Pine  St. 

Peterborough,   IM.   H.   03458 


1 


SPECTRONICS 

the  FM  supplier 


Professional  gear  at  less-than-amateur  prices! 

U43GGT $150.00 

T51GGV $  80.00 

—  All  prices  complete  with  accessories!  — 

L/KE  NEW:  450  MHz  BLOWER  MOTORS $10.00  (motors orriyl 

CALL  OR  WRITE  FOR  OUR  UNBELIEVABLE  SPECIALS  ON  HT200 
NICADS,  "EXTENDED  LOCAL-REMOTE"  PHONES,  OUTDOOR 
SUBMERGENCE-PROOF  25W  SPEAKERS,  HZ3DCN  (BRICK) 
TRANSMITTER  BOARDS,  AND  OTHER  HAM  FM  GOODIES! 


REMEMBER-AMATEURS  ONLY  and  FOR  AMATEUR  USE  ONLY 

PLEASE  SUPPLY  YOUR  CALL  LETTER  WITH  CORRESPONDENCE 

OPEN-9;30  to  6;00     FRIDAY  NIGHT  till  8:00 
CLOSED-SUNDAY,  MONDAY  and  HOLIDAYS 

PHONE;  Area  Code  312-848  6778 


SPECTRONICS 


k^ 


The   FM  People 


11 


1009  GARFIELD  AVE. 


OAK  PARK,  ILL.  60304 


JMH  *J^* 


2  Meter 


6  Meter 

GENERAL  ELECTRIC  . . .  RCA  . . .  MOTOROLA 


When  it  comes  to  great  used  mobile  communications  equipment,  we  wrote 
the  book"  . . .       Send  for  a  free  copy  of  "the  book"  (our  new  catalog). 

Here  are  only  a  few  of  our  LOW  PRtCES: 
2  METERS 


4i 


$148.00 


GENERAL  ELECTRrC  MA/E33  6  or  12  volts,  30  watts 
Vibrator  Power  Supply   with  accessories 

MOTOROLA  X43GGV,  New  Low  Price,  Specia!  Model  in  10"  case, 
30  watt,  transmitter  narrow  band,   receiver  wide  band,  vibrator 
powered,  2  freq.  transmitter,  and  transistor  powered  2  freq.  "Private 
Line"  receiver  (single  squelch),  less  reeds, 
complete  accessories $108*       '"  quantities  often  ....  $88. 


6  METERS 

MOTOROLA  FMTR140D,6  or  12  volts,  60  watt,  wide  band,  ^-j, 
Dynamotor  Power  Supply $4u. 

Transmitter  Narrow  Band $aO. 

Fully  Narrow  Band $68. 

cpmplete  with  accessories       (less  accessories  deduct  $15) 

GENERAL  ELECTRIC  PRE-PROGRESS  4ER6  RECEIVER, 
ET5  OR  ET6  TRANSMITTER 

30  or  60  watts  (as  available),  6  or  12  volts,  aoo 

including  all  accessories $28> 


UHF 


MOTOROLA . . .  T44A6A  with  accessories $38. 

T44AAV  with  accessories $48. 

RCA  CMU15A ...15  watts  minus  accessories $18. 


For  Your  Convenience  SCHEMATIC  DIGESTS.  (Postpaid) 

G.E.  SCHEMATIC  OUTLINE  AND  INTERCONNECTION  DIAGRAMS 
FOR  GE  2- WAY  FM  RADIOS. 

Voi  1  Pre-Progress  Line  ('49  -  '55)    25-50  MHz  72-76  MHz 

Vol.  2  Pre-Progress  Line  ('49  -  '55)  a  ii  en 

150-170,  405-425  MHz,  450-570  MHz each  volume  $4.50 

MOTOROLA  FM  SCHEMATIC  DIGEST 

revised  edition  to  1960 $6.50 


I 


GREGORY  ELECTRONICS  CORP. 


249  Route  46,  Saddle  Brook,  N.  J. 
Phone  (201)  773-7550 


Dept.  73 


^^C^m 


ann 


for  the  best  in  USED  FM 
communications  equipment 


Two-Way  FM  Units  •  Walkies 


Mobile  Phone 


Bases 


Repeaters 
Mobiles 


Here  are  some  of  the  great  buys  at  Mann 

Motorola  Models 


X53GAD 


ME  36 


T43GGV 


2  Meter  Motorola  Mobile  Unit  with  Accessories, 
2  Separate  BOW  Transmitters  with  single  rcvr. 
6/12  Volt  Dynamotor  Powered  in  20  inch 

2  Meter  General  Electric  Mobile  Unit  with  Ace. 
50  Watt  Vibrator  Powered  6/12  Volt  in  17  inch 
Housing $150 

2  Meter  Motorola  Mobile  Unit  with  Accessories 
25  Watt  Vibrator  Powered  6/12  Volt  in  10  inch 
Housing $115 


WRITE  FOR  FREE  CATALOG 


Mann  Guarantee 

Money  refunded  without  question  if  equip- 
ment is  returned  within  seven  days  from 
shipment,  undamagedp  freight  prepaid. 


Conditions  of  Sale 

Unless  otherwise  specified,  equipment  is 
used,  and  is  sold  as-is*  All  items  shipped 
FOB  Tarzana,  California.  Crystals,  ovens, 
antennas  not  included  unless  specifically 
stated  in  catalog.  AH  equipment  is  sold  or, 
a  first-come,  first-served  basis. 


ann  communicatiohs 

RO.  Box  138,  18669  Ventura  Blvd.,  Tarzana,  Calif.  91356 

Phone:  (213)  342-8297 


htroduces  theFMer's  Most  Useful  Tool! 


Integra t ed-Circu it  Freq u ency-Standard  Oscilla tot- 
Generates  a  WW V— Zeroed  Signal  at  30  kHz  Increments  on  2  Meters! 


If  the  .94  in  your  city  seems 
different  from  the  .94  they 
have  in  other  parts  of  the 
State,  you  need  a  standard. 
The  PEP  oscillator  is  that 
standa  rd...as  a  single 
WWV-compared  oscillator,  it 
will  generate  a  solid  and  sta- 
ble rf  signal  on  alt  narrow- 
band and  wideband  channels 
of  the  2  meter  band. 


$19.95  (kit) 

wired  &  tested:  $23.95 


The  circuit  is  a  3  MHz  oscillator  divided  down  to  30kHz  with  an  output 
at  15  MHz  to  zero  with  WWV  and  another  output  that  provides  30  kHz 
markers  on  2  meters.  The  unit  requires  only  a  4V  power  supply  (3 
penllght  cells  are  adequate).  Short-term  stability:  within  50  Hz  at  150 
MHz;  long-term  stability:  within  100  Hz  at  150  MHz.  Wired  and  tested: 
$23.95  -  Complete  Kit:  $19.95  -  Board  &  Schematic  only:  $4.25. 


CORR 


PERFECTION  ELECTRONIC  PRODUCTS  CORP. 


404  E.  HARRISON 


ROYAL  OAK,  MICHIGAN  48067 


J 


1 


RADIO  RECEIVERS  AND  TRANSMITTERS: 

R-390/URR  Receiver,  digital  tuning  BOOkhz  to  32  mhz  .  , ,  .  .  .  , 

Hammarlund  SP-600JX  500khz  to  54mhz ,  .  , * •  •  » 

URR-13  UHF  Receiver,  tunable  200— 400mhz,  ideal  for  UHF  ham  bands  and  monitoring  Air 

Force  and  astronaut  frequencies  *.*.,,.,... ,  •  • •  , 

Collins  R-389/URR  VLF  Receiver,  tunes  15khz  to  ISOOkhz,  the  best  in  VLF ...._. 

R-444/APR-4Y  (ALR-5)  Receiver,  less  ptug-in  converters,  CV-253/ALR  or  TN  plug-ins  .  .  .  ,  . 

ARC  R-19  Receiver,  1 18— 148mhz,  late  version  Command  set  ,_,..__. 

ARC  R-1 1 A  Receiver,  190— 550khz,  late  Q-5er  Command  version 

BC-348  Receiver,  tunes  200— 500khz  and  1 .5— 18mhz  .  . ,  , *...••■ 

NEIVIS  Clarke  Model  1671  Receiver,  175— 260mhz    *  .  . ..*••••.•,•• 

CV-1 57/U  R  R  SSB  Converter,  455khz  i-f  input,  used  on  all  military  receivers  for  SSB  reception   . 
ARN-5  GItdepath  Receiver,  332— 335mhz,  uses  90/150  cycle  tone  transformers  plus  alot  of 

good  components  and  tubes  or  use  it  in  an  aircraft 

TCS-12  Transmitter  type  52245,  1 .5mhz  to  12mhz , 

URC-11   Emergency  Handle  Talkie,  243mhz,  less  1.5  and  135V  battery,  ideal  for  aircraft, 

marine  or  220mhz  conversion,  see  May  69  CQ , , , 

R-48B/TRC-8  UHF  FM  Receiver,  230-250mhz,  115V/60cy  _._.__ 

T-30B/TRC-8  UHF  FM  Transmitter,  230-250mhz,  1 15V/60cy .  . , 

R-316/ARR-26  FM  Receiver,  500khz  through  30.5mhz    ,  .  .  . ,,.....•,..,,.. 

TEST  EQUIPMENT! 

TS-186D/U  Frequency  Meter,  100  to  10,000mhz,  ,01%  accuracy,  1 15V/60cy    .,-... 

TS-535/U  Signal  Generator,  made  by  H.P.,  VLF  Type  7-'100khz,  1 15V/60cy 

TS-318/UP  Field  Intensity  Meter,  range  1550khz  to  2500khz .,...,,, 

H.P.  3358  FM  Monitor,  Has  two  panel  meters  to  show  carrier  deviation  and  percentage  of 

modulation  with  lamp  to  indicate  peak  modulation    ..........,-.,.• ,.,....,.. 

TS-583B/U  Square  Wave  Generator,  range  20cy  to  1 0Okhz   .-,,....,*...... 

AIM/UPM-2  Wavemeter  Test  Set,  range  80— 1220mh2,  absorption  type    ,.....,. * .  . 

TS-226A/AP  Power  Meter,  range  405— 425mhz,  0— 1000W   .  . 

0S-34/USM-32  Oscilloscope,  3WP1  tube,  portable,  genera!  purpo^,  lOcy  to  4mhz .  . 

Motorola  Model  TU*546  Portable  Test  Set  for  Motorola  FM  equipment   *  * 

LM  Freq  Meter  125khz  to  20mhz,  .01%,  AM/CW,  original  calibration  book    , 

SG*85/URM-25D  Signal  Generator,  lOkhz  thru  50  mhz,  0.25%,  portable  type  in  case 

TS-155/UP  Signal  Generator,  2400  to  3750mhz    ...........,...•*, 

A.R.F.    Products    Model    A  R-1  A    FM    Deviation   Meter,    quad    scale,    0^500khz  deviation, 

0 — 220mhz,  nice  to  check  FM  equipment -  #  *  • , 

URM-26  Signal  Generator,  3— 405mhz,  portable  type  in  case,  replaced  Model  80  with  military.  . 
IE -19  Test  Set  for  SCR -522,  has  signal  generator,  field  strength  meter,  VHF  100-156mhz, 

complete  in  case •*.,...-..,,.,.., 

Motorola  F4MV-24B{B)1C,  152— 174mhz,  FM  modulation  and  carrier  station  monitor,  used 

for  FM  alignment , 

UPM-6B  Transponder  Test  Set,  used  to  check  aircraft  transponders.  A  popular  set ........  . 

H.P.  4608  Wide  Band  Amplifier,  19"  rackmount , ,  . 

Ballantine  Model  302  AC  Voltmeter,  range  100/iV  to  1000V , •  • .  , 

Measurements  Model  11  IB  Crystal  Calibrator   .,.,,.,* * * .  ,  * 

Tektronix  RM-IBI  Time  Mark  Generator .  .  .  • * - .  . 

Tektronix  Type  162  Waveform  Generator ^ ,.,,..... 

ZM-11A/U  R-C-L  Bridge,  1 0jHUF - 1 00/iF ,  lOOjUH-IIOH,  1  ohm  to  11  meg 

Western  Electric  Model  19C  Audio  Oscillator,  SOcy  to  150,000cy  .  ,  .  . 

Measurements  Model  79B  Pulse  Generator,  60  to  100,000cps  , , , . 

Ballantine  Model  350  Precision  rms  vtvm,  range  .IV— 300V,  digital  readout 

M99  Dynamotor  Test  Set,  checks  dynamotor  output ..,,..... 

TS-382/U  Audio  Oscillator,  20— 200,000cy,  one  of  the  best    ,,.,..,......... •  .  . 

G.R*  Type  544-B  Megohm  Bridge,  A  to  1000  megohms  *..,.. ............* 


$495.00 

$295.00 

$119.00 
$345.00 
$  37.50 
$  19.50 
$  12.50 
$  65.00 
$  95.00 
$185.00 

$  4,95 
$   19.50 

$  14.50 
$  18.50 
$  18.50 
$375,00 

$  69,00 
$125.00 
$   45.00 

$225.00 
$  49.00 
$  37.50 
$  18.50 
$  85.00 
$  69.00 
$  45.00 
$265.00 
S  65.00 

S  85.00 
$225.00 

$   18.50 

$125.00 
$175,00 
$  35.00 
$  29.50 
$  45.00 
$  27.50 
$  27.50 
$  65.00 
$  18.50 
$  21.50 
$135.00 
$  27.50 
^  /  o  »o\j 
$  60.00 


TELETYPE  EQUIPMENT: 

0-5B/FR  Exciter  Unit 

TT-56/IVIGC  Reperferator  Teletype  Machine  with  keyboard ..,....,. 

AISI/UGC-40  Mitey-Mite  RTTY  Page  Printers 

CV-89A/URA-8  Frequency  Shift  Converter,  audio  type,  built  In  scope,  a  popular  converter  . , 

TT-63A/FGC  RTTY  Repeater,  used  with  FGC-7A 

Northern  type  115  Variable  Master  Oscillator,  2— 32mhz 

RA-87  Teletype  Power  Supply,  converts  ac  to  dc  for  operating  RTTY  line  circuits . 

Test  Set  TS-2/TG  Teletypewriter  Signal  Distortion  Test  Set.  Transmits  four  test  signals,  R,  Y, 

space  or  standard  test  message.  A  needed  item  for  all  RTTY  operations 

CV-57/URR  Frequency  Shift  Converter,  455kc  i-f  type  input,  built-in  scope    

TH-5/TG  Telegraph  Terminal  with  TA-182/U  telephone-telegraph  converter  and  F-98  filter  . . 

Western  Electric  Model  161A1  Telegraph  Station  Test  Set , 

Kleinschmidt  TT -76/000  Reperferator— Transmitter  with  keyboard 


$  13.50 
$  65.00 
$119.00 
$125.00 
$  21.50 
$  65.00 
$   18.50 

$  35.00 

$  75.00 

$  50.00 

$  17.50 

$  85.00 


ALL  EQUIPMENT  EXCELLENT  CONDITION,  F.O.B.  ELLENTON.  FL.  SATISFACTION  GUAR- 
ANTEED OR  MONEY  REFUNDED.  IMMEDIATE  SHIPMENT,  WRITE  OR  PHONE  (813)  722-1843. 

SLEP  ELECTRONICS  C0MPAIMY«2412  Highway  301  N.,«Ellenton,  FL  33532 


NEW  G&G  CATALOG! 

MILITARY  ELECTRONICS 


24  PAGIS,  crommed  wJrh  Gov*!  Surpl^  Et«ctrofiic  Geor  -  t*^e  Big^eir 
Borgaiini  Bu/ih  in  America  t         \f  will  pay  you  to    fSEMP    ^^Z^ 
tor  tFOuf  copy  -    Refunded  with  ytujr  Firif  ofdfcf  ♦ 


BC-645  TtANSaiVet     15  fuhm,  42b  to  5GQ  Ni^. 
Eotity  odapied  for  2  woy  voice  dr  code  on  Ham, 
Mobile,  Televiiiofi  EKperimenhil,  ond  CtHi«n$. 
Bpndti    Wirh  rubes,  leas  power  lupply  ^  *»^ 

r«i  factory  cortan,   SRAND  MEW^,,,,  $16«95 

TRANSMITTIR  hos  4  mKw:  WE-316A,  2-6F6,  7F7 

RECEIVER  has  1 1  rubes:  2-953,  4-7H7,  2-7E6,  3-7F7 

RECEIVER  LF-:  40  Megacycle* 

SIZE:    10-1/2"  K  13-1/2"  x  4-1/2".  Shpg  wt  25  lbs. 

SPECIAL  PACKAGE  OFFER:    6C-645  Trofuceiver,  Dynomofor  and  all 
QQceaoTie^r  including  mounHng,  UHf  AnNnno  Assemblies,  control  box, 
coniplefe  teF  of  connectors  and  plug) «  *#fc*    ^^m 

Bfand  New $26*95 

AN /APR  *  4Y  FM  &  AM  RECEIVER         "FB'^  for  SoreMife  Tracking] 

High  prircHfon  lob  inafryment,  for  morlttof  ing  and 

meoiyring  frequency  ond  relotwe  fignol  itrengfh, 

3fl  (o  4000  Mc.  *n  5  timing  tangvl..    For  tlO  v  60  Cy-    ^^»^^^pr-^^^^ 

deAC.    EbHr- in  power  supply.    Original  circuit         mKmXu9BSKi 

diogram  TfiHciuded,    Checked  ouf,  ^^MI^SiJP^^^^ 

Perfect.    LIKE  NEW*,^..., ,,  $S8.50  lpl0l| 

All  luning  units  orvtailable  for  above. 


TG*34A  CODE  KEYER,     Klf-con^oine^,  oviormiMc, 
repri^ucei^ode  proctice  ligiwll  from  poper  tope* 
5  lo  12  WPM  Builr-tn  speoker.     frond  new  with  tech 
monuoU    tokeup  r«ck  ond  AC  line  cord.  •••S24*50 
Code  prdCitrce  tapej  for  above  P.U.R, 

WllLARD  2-VQLT  STORAGE  BAHERY 

Ra red  ot  20  Amp- -Hours.    Model  20-2.    iechiaf^obte, 
Coitipoct  r>an$pill  conslruction.    Lightweight  polytty- 
rene  conramer,  3x4x3  1/2*'*     Shipped  dry,  uses  itondord 
electrolyte.    Shipping  Weight  3  Ibt^    NEW,  eoch* •••«•**• 


.  $2.79 


HEADSET 

Low  inipedonce^    With  large  chomoii  oor  cushions.    4-ft,  cord  one 

plug.    Reg.  il2.50*    OUR  SPECIAL  PRICE,, .,. $2*95 

High  Impedortce  ladoptor  for  above » ,  ^^C 


SCR-274-N,  ARC-S  COMMAND  SET  HQ! 


Freq. 
RECCIVEflS, 

B  ■  9  T  *     M'C .  .  .  4  .   ' 

4f S ■  S    Mc ■ 

7^9. 1     *«C  ^  .  .  . 


t^pe  Oied 

Cam0irte  vrltti  Tube* 

ec  4S3  tl£.9£ 

BC-4S4.  tie-50 

eC-4  5S                             $14.93 
«-25  


LlHe 
14  ew 

it9-50 
1 17^95 
919. SO 


CoTnotrl# 

BC-4S7 
BC-4SH 
BC-459 


with    TLltvl 
%    «.95 


BJtAMO 
NEW 

92?. SO 
922  94 
421. SO 

.tri.so 

f  1  t  .99 

911-^4 
92  3  $D 


ARC-RllA  Modern  Q-5  Receiver  190  -  550  Khi  ,.**• 
ARC-R22  540  -  lAOO  Khz  Receiver  with  tvnln^  graph 
R*4/ARft-2    R««eiver  234-258  Mh£,  11  hibn,    NEW  .. 


-  *  4-  »  ■  w  a 


S16.S0 
„  124  SO 


SCR-625  ARA^Y  MINE  DETECTOR  Complete  .  •  •  * *  ^32. 50 

EE-8  SIGNAL  CORPS  fJELD  PHONIS $16.95 

T-30  THROAT  MIKE,      NEW 59?        USED , ...  39? 

T-17  MICROPHONE,      NEW $8,50     US  ED,  checked  out  $4,95 

6C-605  INTERPHONE  AMPUFIER,  NEW  $3*45  EXCUSED. .. ,  $1.95 

TELEPHONE  HANDSET,  W.E.  type, ....LIKE  NEW        $2*95 

SCft-522  TRANSMITTER-RECEIVER,  wtth  18  tobef -  LIKE  NEW432.50 


AM -200/ Arc  PUSHPULl  AMPLIFIER 

4-tvbe  PP  power  amplifier  wlfh  dynomotof,  worUi  on 
28  VDC*  Automotic  gain  control-  *ji   n 

SlipQwt15lb*   LIKE  NEW J4,95 


FREQUENCY  METER  MODEL  LM 

fifie  ger»erol  purpoie  Navy  unit,  rangift  125  to  20,000 
Kc.  Operotes  on  12/24  VDC  &  200V  10  Mo  DC* 
Complete  witfi  tgbes,  crysta  I ,  co  U  b  *  bcxjk. 

Checked  out,  EXCELLENT  USED , ,  $59.50 

Aj  above,  le»  book  $24.50  AC  Power  Supply. $19,50 


McELROY  AUTOMATIC  KEYER  for  keying 

tronsmittef  or  for  code  proctice, Photoelectric  cell 
&  ^emitrve  reloy  *  Voriobie  speed  mofor  110V  60  cy 
Complete  with  tube*,  EXC,  USED $11.25 


BC'733  RECEIVER  Receivei  radio  signqls 

being  trartsmitted  by  US  Kile  Mite  on  approx,   108 
Mc#  AM^  crystD  I -controlled  o#*  6  preset  freqs«  in 
108,3  to  1 10,3  Mc  range.  Operates  on  12/24  V 
DC  &  220  VDC  80  V«,  Complete  witH  10  tub«* 
Con  be  converted  to  FM  Receiver 

SO  to  TOB  Mc,  bccUsed.. $5,95 

BC-732A  Control  Box  for  above,  NEW. . .    1 ,75 


T-41  /  APS  -  18  TRANSMIHER 

ANTENNA  UNIT        designed  for  115  V  600  to 
1400  cp(.  Tubes  irvcluded  ore  two  T5£  ond  one 
15R,  Cofnplete  with  shock  moirnti 
arwJ  bbvyer  f7iotor.7xax18\  NEW $7-45 

RAOrO  SET  AN/  APR-21  TRANSMIHER 

&  RECEIVER     .   Freq.moduloted  152  to  174  Mc, 

Operated  on  any  preset  freqi>ency  wit4iin  VHF 

range  152-174  Mc  FM.  Relioble  voice  communi- 

catto*!  over  moderate  distances.  Includes  ontenna, 

handset  H~33  and  two  carrying  slTaps, 

Size  12i«8^l/4^5-3/4*  Wl  15  lb. 

LIKE  NEW,  complete $69.50 


AM-26/A1C  PHASE  INVERTER  AMP. 

4  —tube  pushpu^ll  power  amplifier*  Corbotf  mike 
input, hi -lo  imp*  output*  Workj  on  24 VDC*  Eas- 
ily converted  to  dor^dy  9'^>watt  amplifier*  Complete 
with  tubes  ond  dynomotor 
UKE  NEW $6«95 

DUAL  AMPLIFIER         bos  Iwo  inpur  circuits  eoch 
feeding  a  single  6SN7GT  twin  triode  dmplifier, 
Cornplete  with  1 15V  60  cy*  power  supply 
gssing  6X5 GT  rectifier.    NEW 95*95 

IP-69A/ALA-2  INDICATOR           3"  scope* 
Front  porkfll  contnols:  Vertical  Pos*;hori£ontol  poi. 
intensity,  locus,  gain,  width ^  center  ffoq.  Pan, 
Operates  or^  1 15  V  380  to  TOOO  cF»^ 
Complete  wtth  tubes.  LIKE  NEW $24-50 


BC-929  US  GOVT  SCOPE  INDICATOR 
Compact  nador  display  unit  uses  3BP1 ,  A  favorite 
with    TTY  fans  os  foundation  for  converter  with 
cross-Jme  scope    presenfation,  Aiso  for  Horns s 
Modulation-monitor  foundation. 
Complete  with  all  tubes,  LIKE  NEW. . . .  $16*95 


I 
I 


I 


TG-5B  TELEGRAPH  SET           for  code  commun- 
ications or  code  practice*  Portable,  with  hinged 
lid*  Two  or  more  unSti  operate  up  to  25  miles  o- 
parK  Bell  coll  iyitsm,  TOOO  cycle  Howler,  key^ 
headpi  ece  ,  co  nvos  case  ,  book . 
SJze  5-1/^5-1/2x10-,   NEW .  _$8*95 


TS-100AP  TEST  OSCILLOSCOPE        StmII 

portable  instrument  used  to  test  ond  calibrore 
range  meosuring  circuits  of  rodar  systems*   Ui&i 
for  viewing  short  video  pulses  on  3"  t(^ee»i, 
PovAfef  supply;  ITS  or  230  V  50-1200  cps. 
Complete  wItK  pi  tigs,  cobles. . . . .  ^**  ,*,  $59*50 


TS-126/AP  RANGE  CALIBRATOR  TEST 
SCOPE  Top  quolJty  2"  scope  with  oil  position- 

ing, focus,  gain  and  intensity  cor^trols* 
Complete  wllh  tubes  ond  cobles,  NEW.  $24. SO 
Demilitarized, like  new. ......  *****.**,,  i  $  13,75 


TELEPHONE  TYPE  RELAY 

Mode  by  J.H.Bunnell,  hos  adjustable 
sensitivity.  150  ohm  coil.  NEW $3»45 


T-28   /   APT  TRANSMITTER          ,  rodor  jomming 
covering  freq.  140  to  210  Mc,   0$c . Amp p Plate, 
Grid  Plote  &  Mixer  Plate  controls  on  front  panel. 
Complete  with  tubes,  7-1/2x10x20" 
Wt40  lbs,  NEW $32,50 


rFHM;S;       1:^  .   l>[|KtMt  *  tUi  oriJi»r,  balaiti:*  r*U«li.  -vr-  KcmiUanci?  in  lull, 
MinMiium  urUrt  $b,w\    j^.ti.  H,    NVt'.   Subjt*!  U.  ifriipf  ^ialv  and  |>riCL'  ehvi^i^i^^ 

G&G  RADIO  ELECTRONICS  COMPANY 

47  Warren  Sf ,  '2r%d  F! !  New  Yorfc.  NY.  10007      Ph   212-267-4605 


the  all 


ii 


NEW 


ft 


CRYSTAL .  CALIBRATOR 

100-50-25-  KC  Markers 

•  Zero  Beat  to  WWV 

•  Uses  New  100  KC  Crystals 

(included  in  all  units) 

•  Glass  Epoxy  Boards 
•  Very  Compact 

rxTxYz" 
•  3.5  v.  Operation 


tMTlGRAUD   CIRCUITS 

FACTORY  FRESH  -  NO  REJECTS 

W/SPEC.    SHEET 

FAIRCHILD  -  MOTOROLA 

UL  900  BUFFER    80c— 10/6.00 

UL  9U   GATE    80c— 10/6.00 

UL  923  J  K.  FLIP-FLOP    $1.50—10/900 

MC  790P  DUAL  JK  FLIP-FLOP.  $2.00— 10/18.95 
MC  789P  HEX   INVERTER  i      i  i« -, 

10/9.50 


MC  724P  QUAD   2    INPUT  GATE 
MC  799P  DUAL  BUFFER 


\ 


MC  780P  DECADE 

MC  757P  QUAD    LATCH 

MC  9760P    DECODER   DftJVER    .  .    . 

THREE  ABOVE  $11.95 


V      4      *       * 


r    1      *    «      4 


$3.50 
$3.50 
$S.50 


KIT 


with 
100  ffC 

cfty5r4L 


Wired  and  zeroed 
to  WW  V  $15.95 


ARN-30  108-135  mc  tunable  re- 
ceivers. High  frequency  version  of 
the  famous  command  receivers.  Lis- 
ten to  local  airport  frequency  or 
convert  to  2  mc.  New,  with 
schematic  and  operating  instruc- 
tions  $19.95 

Western  Union  facsimile  machines, 
send  and  receive  pictures  and 
memos.  Works  on  lib  v  60  cycles. 
Shipped  with  auto-start,  auto-phase 
&  pos-4-pos,  conversion  instruc- 
tions  $19.95  each 

Telfax  paper  2d  each,  1000  for 
$12.95. 


,^^f  r 


KIT  INCLUDES: 


1-PC  BOARD  and  CONNECTOR 
1-NL  940S  READ  OUT  TUBE 

anil  SOCKET 
1-MC  9760  DECOOER  DRIVER 
1— MC  780P  DECADE 
1-MC  767P  QUAD  UTCH 


NIXIE 

READ   OUT 

STAGE 

"NEW" 

FROM 


USES: 

•  FREQUENCY    COUNTER 

•  DIGITAL   VOLTMETER 

.  TIME   INTERVOLTMETER 

•  DIGITAL  CLOCK  (has  facilities  for 

dividing  by  six  for  clock) 

PRICE  1  ta  2  -  $21.49  EA. 
PER  3  to  4  -  $20.49  EA. 
KIT         5  Of  more  $18.25  EA. 


R  &  R  ELEaRONICS,  311  E.  SOUTH  ST.,  INDIANAPOLIS,  IND.  46225 


UP 

Professionally  Engineered  Antenna  Systems 


Single  transmission  line  "TRI-BAND*  ARRAY" 


By  the  onfy  test  that  means  anything  ,  .  . 
on  the  air  comparison  . . .  this  array  con- 
tinues to  outperform  all  competition  , , , 
and  has  for  two  decades.  Here's  why 
,  .  .  Telrex  uses  a  unique  trap  design 
employing  20  HiQ  7500V  ceramic  con* 
densers  per  antenna,  Telrex  uses  3  opti- 
mum-spaced, optimum-tuned  reflectors 
to  provide  maximum  gain  and  true  F/B 
Tri-band  performance. 

ONLY  TELREX  GIVES  YOU  ALL 
THESE  FEATURES--. 

•  Power  rating  4  KW  PEP  . . , 
rain  or  shine 

•  Wind  rating  survival  110  MPH 

•  Patented  broad-band  coaxial  Balun 

•  Heavy-duty  steel  gusset  mounting 
plate 

•  Aluminum  boom  2  in.,  2Vz  in.  0*0, 
X  18  ft. 

•  Large  diameter,  .058  wait  taper- 
swaged  dural  elements  for  minimum 


weight  and  exceptional  strength 

to  weight  ratio 

Stainless  steel  electrical  hardware 

a  Telrex  Tri-band  Array  you  get  49 
lbs.  of  educated  afuminum  engineered 
and  built  to  provide  many,  many  years 
of  performance  unmatched  around  the 
world  by  any  other  make.  Longest  ele- 
ment 36  ft.  Turning  radius  20  ft.  Shipping 
weight  65  lbs.  Shipping  container  13  in- 
x  5  in.  X  13  ft 

Note:  If  not  available  from  your  dealer, 
order  direct.  YouM  get  fast,  personal 
service. 

Telrex  Labs  are  design  engineers,  inno- 
vators and  manufacturers  of  the  world*s 
finest  %  to  160  meter  communication 
systems  and  accessories  priced  from 
$25  to  $25,000. 

For  technicaf  data  and  prices  on  com- 
plete Telrex  tine,  write  for  Catalog  PL  71, 


TC99D 


BALUN 


\ 


t4 


J^  ^. 


Elements  shortened 
to  show  details. 


■> 


TRAP 


L 


I 


Some  thoughts  from  Mike  Ercolino,  P,E,  —  W2BDS,  Telrex  Chief  Engineer . . . 


'Tve  been  in  the  game 
over  50  years  (pounded 
brass  for  25}  and  found  out 
a  long  time  ago  that  an- 
tennas were  the  weak  link. 
We  changed  all  that" 


*'Good  antennas  such  as 
those  we  build  can  be 
ruined  in  two  minutes  by  a 
tinker.  So  put  'em  up  and 
leave  'em  up  the  way  we 
make  'em/' 


''Our  Big  Bertha'  systems 
cost  more  than  a  Rolls 
Royce,  Three  of  our  cus- 
tomers have  bought  two  of 
them  , . .  that's  living." 


—let 


fp  V  COMMUNICATION  ENGINEERING  LABORATORIES 

■    %^y^  TV  And  Communications  Antennas  Since  1921 

Asbury  Park,  New  Jersey  07712     201-775-7252 


1 


ATTRACTIVE  PRICES  for  the  R39QA 


L.!!'i«  QM» 


The  R390A  communications  receiver,  long  used 
for  rniiitary  surveillance  of  discrete  frequen- 
cies between  500  kHz  and  32  mUz,  is  a- 
vai table  now  at  but  a  fraction  of  its  worth.  Both 
new  and  remanufactured  sets  are  in  stock  each 
furnished  with  appropriate  Instruction  Manuals 
and  necessary  ancillary  parts. 

Providing  digital  readout  with  an  accuracy  to  300 

Hz,  the  R390A  is  the  latest  and  best  made 
general  coverage  communications  receiver 
that  you  can  buy.  Robustly  constructed  on 
sub-assembled  units  this  receiver  provides 
unequaled  stability  and  maximum  flexibility  of 
controls.  Six  degrees  of  band  pass  from  100  Hz 
to  16  kHz  and  two  positions  of  audio  filtering 
enable  this  set  to  be  used  for  the  most 
sophisticated  moon  bounce  conversion  purposes 
all  the  way  down  to  deluxe  short  wave  listening. 

Mechanically  this  receiver  Is  a  marvel  of  gears, 
ratchets^  and  cams  providing  ferrite  slug  tuning  of 
both  the  front  end  and  one  of  the  triple 
conversion  IF  stages. 

There  are  two  audio  systems  within  the  set,  one 
intended  for  feeding  a  monitored  600  ohm 
telephone  line  and  the  other  used  for  a  local  loud 
speaker  loop.  Two  meters  are  provided,  one 
measuring  the  incoming  RF  signal  and  the  other 
the  level  of  audio  set  to  fit  a  600  ohm  line. 

The  balance  of  this  set  is  impressive,  the  knobs 

for  example  having  been  designed  for  maximum 
comfort.  The  controls  are  not  so  closely  set  that 
any  of  them  are  awkwardly  adjusted.  There  is,  of 
course,  a  dial  lock  and  a  means  of  zero  adjusting 
to  the  extremely  high  quality  calibrator  circuit 
provided  internally.  There  is,  of  course,  the 
antenna  trim  control  and  the  AGC  slow,  fast,  and 
medium  control.  The  very  effective  noise  I i miter 
is  built  in  and  of  course  the  receiver  is  designed 
to  be  used  with  associated  transmitters  and  is 
therefore  provided  with  a  muting  cirucit. 


Both  balanced  and  unbalanced  antenna  inputs  are 
available,  and  there  is  an  IF  output  at  50  ohms  to 
enable  the  receiver  to  function  with  a  spectrum 
analyzer  or  a  panoramic  adaptor. 

Perhaps  one  of  the  most  unusua!  advantages  of 
the  receiver  is  its  extreme  stability.  It  is  so  good, 
for  example,  that  you  can  pretune  the  receiver  to 
any  choice  frequency  such  as  the  Canadian  Time 
Standard  CHU  in  Ottawa  or  to  our  American 
WWV  even  while  the  set  is  cold  and  in  off 
position.  Turning  on  the  set  and  then  turning  up 
the  audio  control  will  reveal  the  desired  signal 
perfectly  tuned  in.  So  accurate  is  this 
presentation  that  you  can  literally  use  the 
receiver  as  a  frequency  meter.  This  unusual 
stability  is  achieved  by  a  combination  of  superb 
mechanical  engineering  and  very  expensive 
permeability  tuned  oscillators  one  of  which  is 
used  as  a  VFO  control  while  the  main  one,  of 
course,  is  ganged  mechanically  with  a  kilocycle 
change  knob. 

Thermostatically  controlled  ovens  enclose  both 
PTO's  and  the  crystal  oscillator  circuitry.  The 
R390A  can  be  used  remotely  with  suitable  signal 
circuit  control  connections  to  the  terminals  of 
the  set. 

Although  the  set  was  designed  for  CW,  MCW, 
AM,  FSK  and  SSB,  it  does  not  contain  a  product 
detector.  We  can  add  in  our  shop  a  compatibly 
designed  product  detector  assembly  at  a  small 
additional  cost  which  will  facilitate  tuning 
sideband  signals. 

This  is  the  ultimate  communications  receiver 
priced  at  a  figure  that  serious-minded  individuals 
can  afford.  Many  professional  men  or  those  who 
have  recently  retired  have  purchased  these 
receivers  from  us  to  their  entire  satisfaction.  It  is 
the  kind  of  set  which  will  last  years  and  years  and 
years.  Indeed  there  would  be  no  normal  reason 
for  ever  wanting  to  replace  such  a  set  for  the 


generally  available  merchandise  made  these  days  tf    sufficient    numbers    are    interested,    we  will 

does    not    begin    to    approach    in    quality    or  prepare     an     illustrated     brochure    about    this 

performance    what    you    can    expect    from   the  receiver  and  make  it  available  without  charge.  In 

RCSOA.    Foreign    customers   should    understand  the  meantime,  study  the  specifications  and  if  you 

ttiat  the  set  will  also  function  on  230  volts  50-60  are  in  the  vicmity  of  Harvard,  Mass,  do  stop  in 

cycles.    Although    when    packed    in    its   special  for       a       demonstration       of       this       superb 

container  the  shipping  weight  is  100  lbs,  the  net  communications  receiver. 
weight  of  the  set  itself  is  but  75  lbs.  The  shipping 
cube  is  3.9  cubic  feet 

PRICE  LIST 

R390A  new $1495 

R390A  new  fitted  with  product  detector 1565 

R390A  remanufactured 1 195 

R390A  remanufactured  fitted  with  product  detector 1265 

R390  remanufactured    995 

R390  remanufactured  fitted  with  product  detector 1065 

R391  new 1995 

R391  new  fitted  with  product  detector .2065 

R391  used  fitted  with  product  detector 1865 


? 


I 

The  R390  is  the  original  series  Bet,  Essentially  the  same  is  the  R390A  with  a  more  complex  mechanical 
tuning  system  and  a  voltage  regulated  power  supply^  The  391  is  a  special  series  similar  to  the  390  but 
intended  for  servo-con  trolled  remote  operation  of  up  to  seven  pre-deter  mined  frequencies.  Above 
prices  are  FOB  Harvard,  Alass.  Shipments  are  effected  in  approximately  two  weeks  after  receipt  of 
order  and  remittance, 

TECHNICAL  CHARACTERTSTCS  OF  R390A  RECEIVER 

Type      of      circuit:       Triple-conversion     superheterodyne      on      eight      lowest      frequency      b^nds; 

double-conversion  superheterodyne  on  all  other  bands. 
Frequency  range:  0.5  to  32  me. 
Types  of  signals  received:   Al,cw;  A2,  mew;  A3,  voice;  A9,  single  side-band,  Fl,  frequency-shift 

Keying, 
Type  of  tuning:  Continuous;  frequency  read  directly  on  counter-type  indicator. 
Method  of  calibration:  Built-in  cry staJ-contr oiled. 
Calibration  points:  Every  100  kc. 

Audio  power  output: 

60Q-ohxn  unbalanced  line 

600-ohm  balanced  line 

Headphones   ...,.,,,.,........ 

IF  selectivity:  100  cps  to  16  kc  bandwidth  in  six  steps. 
Intermediate  frequencies: 

First  variable  IF  (used  on  eight  lowest  frequency  bands)  17.5  to  25  mc- 

Second  variable  IF  (used  on  all  bands)  2,5  to  2  mc  on  lowest  band:  3  to  2  mc  on  all  other  bands. 

Third  (fixed  IF)  455  kc,  _^ 

Power  source;  115/230  volts  ac  ±10%,  48  to  62  cps. 
Power  input: 

115/230  volts  ac;  225  watts  total:  140  ^atts  with  OVENS  switch  turned  OFF. 
Number  of  tubes:  26  (including  current-regulator  tube  RT510)* 
Antennas: 

Unbalanced:  Straight-wire  of  random  length  or  vehicular-mounted  whip. 

Balanced:    125-ohm    terminating    impedance;  matches  50   to   200-ohm  balanced   or  unbalanced 

transmission  lines  by  using  adapters. 
Temperature  range:  — 40oc  (--40c*F)  to  65^0  {149oF) 
Altitude:  Up  to  10,000  ft*  above  sea  leveL 
Weight:  75  lbs. 
Range  of  tuning  PTO:  3.455  to  2,455  mc. 


#  «  •  •  « 


n     «     * 


500  mw,  minimum. 
-  10  mw,  minimum, 
.  .  .Imw,  minimum. 


HERBERT  W:  GORDON  COMKVNT 

HELPING    HAMS  TO  HELP  THEMSELVES 


T' 


PHONE    617  456  3548 


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73  MAGAZINE 


STUDY 
GUIDE 


ILIKgJl 


Partv   Something  for  Nothing 


For  nearly  50  years,  the  vacuum  tube 
reigned  supreme  and  virtually  unchal- 
lenged as  the  amplifier  for  electronics. 
From  the  passing  of  the  spark  gap  and 
decoherer  in  the  years  following  the  first 
world  war  until  the  advent  of  the  transistor 
in  1948,  the  vacuum  tube  had  no  serious 
competition. 

The  period  of  the  vacuum  tube,  not 
entirely  by  coincidence,  was  also  the  time 
during  which  electronic  engineering  as  it 
now  exists  made  the  major  part  of  its 
growth,  and  the  characteristics  of  the 
vacuum  tube  left  their  indelible  imprint 
upon  the  entire  field* 

And  despite  the  phenomenal  growth  of 
semiconductor  electronics,  some  areas  yet 
remain  the  province  of  the  vacuum  tube* 
UHF  amplifiers,  cathode-ray  tubes  such  as 
TV  picture  tubes,  and  high-voltage  devices 
are  three  major  regions  in  which  the 
vacuum  tube  remains  the  least  expensive 
device  to  do  the  job. 

Both  because  the  vacuum  tube  is  still  in 
wide  use,  and  because  many  other  areas  of 
electronics  and  radio  in  particular  are  built 
upon  a  foundation  derived  from  vacuum- 
tube  experience,  the  General  class  amateur 
examination  contains  a  number  of  ques- 
tions dedicated  to  determining  the  appli- 
cant's knowledge  of  vacuum  tubes  and 
their  operation. 

The  specific  questions  in  the  FCC  study 
list  are: 

5.  Describe  the  operation  and  usage  of  a 
cathode  follower, 

8,  How  is  the  plate  circuit  efficiency  of 
a  vacuum  tube  determined? 

14- What  is  meant  by  the  maximum 
plate  dissipation  of  a  vacuum  tube? 


5 1 .  Compare  the  operating  features  of 
the  grounded-grid  and  grounded-cathode 
amplifiers. 

Not  one  of  these  four  questions  makes 
any  sense  at  all,  unless  you  are  already 
familiar  with  the  principles  upon  which  a 
vacuum  tube  operates.  Before  we  can  get 
into  the  details  required  for  the  FCC 
questions,  therefore,  we  must  delve  into 
just  how  tubes  do  their  job.  Then  we  can 
examine  the  various  ways  they  are  used 
and  the  factors  which  limit  their  use,  to 
determine  answers  to  the  exam  questions. 

Our  first  question,  then,  will  be  "How 
does  a  vacuum  tube  work?''  When  that  is 
out  of  the  way,  we  can  move  on  to  learn 
**What  factors  limit  a  vacuum  tube's  useful- 
ness?'*, and  finally  find  out  "How  are 
vacuum  tubes  used?"  By  the  time  we  get 
even  a  brief  view  of  the  realms  opened  up 

by  our  final  question,  we  should  have 
adequate  knowledge  of  tubes  and  their 
operation  to  handle  any  questions  such  as 
those  on  the  study  list. 

With  such  a  broad  set  of  questions,  and 
limited  space  in  which  to  explore  them,  we 
cannot  go  into  excessive  detail  about  any 
part  of  vacuum-tube  operation.  Here,  we're 
only  providing  enough  to  satisfy  the 
General  class  exam  questions. 

How  Does  a  Vacuum  Tube  Work? 

Before  we  can  determine  how  a  vacuum 
tube  works,  we  must  first  determine  just 
what  a  vacuum  tube  amounts  to.  Even 
though  we  know  that  by  "vacuum  tube" 
we  mean  only  those  gadgets  used  in  radio 
transmitters  and  receivers,  that  still  leaves 
an  almost  unbelievable  amount  of  terri- 
tory —  diodes,  Iriodes,  tetrodes,  pentodes. 


DECEMBER    1970 


75 


hexodeSj  heptodes,  multifunction  tubes, 
klystrons^  magnetrons,  ,  ,The  list  doesn*t 
go  on  forever,  but  it  might  as  welL 

Ail  of  those  special  types  of  tubes  share 
the  fact  that  they  consist  of  electrodes 
sealed  into  a  tube  full  of  vacuum.  Since 
"vacuum'*  is  defined  as  the  absence  of 
anything  else,  that's  where  our  phrase 
about  "something  from  nothing"  derives. 
Unfortunately  as  we  have  just  illustrated, 
that's  not  precise  enough  to  sort  out  the 
kind  of  *  Vacuum  tubes"  the  exam  is 
concerned  with. 

Rather  than  try  to  define  .all  the  differ- 
ences, let's  start  with  the  one  common 
element  and  see  what  develops. 

We  already  know  that  an  electrical 
circuit,  to  be  a  circuit,  must  be  complete. 
That  is^  it  must  have  both  an  input  and  an 
output.  Even  the  simplest  vacuum  tube, 
then,  must  have  at  least  two  different 
electrodes  sealed  into  its  vacuum,  one  for 
input  and  one  for  output. 

The  first  recorded  vacuum  tube  was  just 
about  that  simple.  It  was  built  by  Thomas 
A,  Edison  in  1883,  and  its  operation  as  a 
vacuum  tube  was  purely  accidental.  Edison 
was  trying  to  improve  his  newly  invented 
incandescent  lamp,  and  one  of  his  experi- 
ments was  to  put  a  metal  plate  into  the 
bulb    near   the  filament  (Fig.    1).   He  dis- 


FrUAMENT 


EVACIJATED 

GLASS 

ENVELOPE 


Fig.  J*  Vacuum  tube  owes  its  existence  to  Edison 
effect,  discovered  by  light  bulb*s inventor.  Circuit 
which  revealed  Edison  effect  is  shown  here.  Metal 
plate  was  sealed  into  hulb^  near  filament  but 
electrically  insula  ted  from  it.  When  filament  lit, 
current  flowed  between  plate  and  filament  More 
current  flowed  when  plate  was  connected  to 
positive  pole  of  filament  battery,  than  when 
connected  to  negative.  Edison  didn't  know  why 
this  happened;  others  followed  it  up. 


covered  that  when  the  filament  lit*  a  small 
electric  current  flowed  between  plate  and 
filament.  The  discovery  was  duly  notedj 
published,  and  became  known  to  the  world 
as  ''the  Edison  effect."  Since  it  did  nothing 
either  way  for  the  operation  of  the  light 
bulb,  Edison  apparently  ignored  it  and 
went  on  to  other  inventions  —  thereby 
missing  the  chance  to  become  known  as 
the  inventor  of  electronics  atop  all  his 
other  laurels! 

Serious  scientists  did,  however,  sit  up 
and  take  notice  of  the  Edison  effect.  As  a 
direct  result  of  it,  Sir.  J*  J.  Thomson  spent 
several  years  in  study  and  experiments,  and 
in  1900  or  so  announced  to  the  world  his 
"electron  theory-"  That's  the  familiar 
structure  of  electrons,  protons,  and 
neutrons  which  we  accept  now  as  the 
**true"  picture  of  the  way  things  are  made, 
and  the  reasons  for  electric  current. 

The  electron  theory  explained  the  cur- 
rent of  the  Edison  effect  as  an  '^evapora- 
tion"  of  electrons  from  the  surface  of  the 
filament,  caused  by  the  heat  energy  present 
in  the  filament.  As  these  electrons  boiled 
off,  some  struck  the  metal  plate  —  and  any 
time  we  have  electrons  in  motion^  we  have 
to  have  a  current.  That's  the  current 
Edison  observed, 

Edison  also  noticed  that  when  he  con- 
nected the  metal  plate  to  the  positive  side 
of  a  battery,  the  current  flow  went  up,  and 
if  the  connection  was  to  the  negative  side, 
the  current  went  down.  This  showed  that 
the  moving  particles  had  to  be  negative  in 
polarity,  since  they  were  attracted  to  a 
positive  pole  and  repelled  by  a  negative 
one, 

A  few  years  later,  in  1905,  an  Engiish- 
man  named  Fleming  obtained  a  patent  on  a 
device  making  use  of  the  Edison  effect, 
which  he  called  a  "valve."  It  was  intended 
to  detect  radio  signals  by  making  use  of  the 
one-way  property  inherent  in  the  current 
flow  from  a  hot  filament  to  a  metal  plate 
(anode).  It  worked  in  just  the  same  way  as 
today's  diode  detector  circuits,  and  it 
established  ihe  vacuum  tube  as  a  part  of 
the  growing  art  of  radio  communications. 

Let's  look  a  little  more  closely  at  just 
what  goes  on  in  the  simple  diode,  since  it 
was  the  first  vacuum  tube  to  be  discovered. 


76 


73  MAGAZINE 


the  first  to  be  used,  and  is  still  the  basis  of 
all  conventional  vacuum-tube  action ^ 

We  have,  as  we  have  mentioned,  two 
elements  inside  the  vacuum  for  a  diode. 
One  is  known  as  the  cathode,  and  the  other 
is  called  the  anode,  or  piate. 

The  cathode  is  normally  heated  to  a 
rather  warm  temperature  (between  1000 
and  3000^ F.)  The  heating  may  be  done  by 
a  separate  '*heater'*  which  is  electrically 
insulated  from  the  cathode  itself,  or  it  may 
be  done  by  forcing  a  current  through  a 
high-resistance  cathode  materiaL  Normally, 
an  Indirectly  heated  cathode  makes  use  of 
a  "heater,"  and  the  word  *'filament"  is 
reserved  to  mean  a  combination  heater  and 
cathode.  So  far  as  the  basic  principle  of 
operation  is  concerned  it  doesn't  make 
much  difference  where  the  heat  comes 
from  so  long  as  it's  present,  but  in  practice 
if  ac  is  used  to  provide  heating  power  it's 
better  to  keep  the  ac  out  of  the  signal 
circuitSj  and  so  the  heater— cathode  com- 
bination is  most  frequently  encountered  in 
ordinary  tubes. 

At  the  cathode  temperature,  some  of 
the  electrons  of  the  cathode  material  liter- 
ally boil  off  into  the  empty  space  sur- 
rounding the  cathode.  This  forms  a  cloud 
of  electrons  known  as  the  "space  charge*' 
around  the  cathode  itself. 

The  plate  or  anode  is  separated  from  the 
cathode  by  distance,  and  it's  far  enough 
away  that  the  space  charge  never  quite 
reaches  it. 

Under  these  conditions,  with  no  voltage 
applied  between  plate  and  cathode,  the 
space  charge  is  self-limiting.  It  always 
contains  all  the  electrons  emitted  (boiled 
off)  from  the  cathode,  and  so  always  has  a 
negative  charge  which  just  balances  the 
positive  charge  produced  on  the  cathode 
by  loss  of  the  electrons. 

If  the  temperature  of  the  cathode  is 
raised  so  that  more  electrons  are  emitted, 
the  space  charge  will  increase,  but  the 
current  flow  to  the  plate  will  remain 
essentially  zero*  Similarly^  if  the  cathode 
temperature  is  lowered,  the  plate  current 
will  remain  unchanged  at  zero. 

If  we  return  the  cathode  to  "normal" 
temperature  and  put  a  small  positive  volt- 
age on  the  plate,  the  picture  changes.  The 


positive  voltage  on  the  plate  attracts  some 
of  the  electrons  from  the  space  charge,  and 
a  current  flows  between  plate  and  cathode. 
Not  all  the  emitted  electrons  reach  the 
plate,  though.  When  we  put  voltage  on  the 
plate,  this  created  a  "voltage  gradient" 
from  cathode  to  plate  something  like  a  hill 
in  the  path  of  the  emitted  electrons  (Fig. 
2),  and  only  those  electrons  which  left  the 


NEAT  FOF»ceS 
ELECTRONS  OUT 


HILL  PRODUCED 
SY  SPACE  CHARGE 


1 


liiOTlO«i  OF 

ELEcrnoiiS 


Z^" 


VOi.TACE-  O 


+  50 


+  100 


€:ATHOO€ 
Sl^n^ACE 


SURFACE 


IMPACT 

RELEASES 

ENERGY 


Fig*  2.  Action  of  electrons  inside  simple  diode 
tube  is  shown  here.  Difference  in  voltage  between 
cathode  and  plate  surfaces  forms  a  'Vo/tage 
gradient"  shown  here  as  a  downhill  slope.  Space 
charge  puts  a  hump  in  this  hill,  near  the  cathode. 
Angry  ram  represents  action  of  heat,  boiling 
electrons  off  the  cathode  surface.  Those  electrons 
with  enough  energy  to  make  it  over  the  hump  fall 
down  the  hill,  and  hit  the  plate  with  a  crash, 
releasing  more  heat. 


cathode  with  enough  energy  to  "make  it 
up  the  hill"  go  to  the  plate.  Some  are 
repelled  by  others  in  the  space  charge,  and 
a  few  even  return  to  the  cathode  as  a 
result. 

Making  the  cathode  hotter  doesn't 
change  things  much  --  but  if  we  cool  it 
down  somewhat,  the  number  of  electrons 
in  the  space  charge  is  reduced  and  we  find 
that  the  "hUl"  is  not  so  steep.  As  the 
temperature  cools,  we  find  one  point  at 
which  all  the  emitted  electrons  go  over  to 
the  plate. 

We  can  achieve  the  same  effect  without 
changing  cathode  temperature  if  we  simply 
increase  plate  voltage.  When  plate  voltage  is 
high  enough,  it  will  pull  all  the  electrons 
over  the  hill 

In  a  diode,  we  have  only  these  two 
factors   available   with  which   to  vary   the 


DECEMBER    1970 


77 


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plate  current.  If  either  stays  constant,  the 
other  exercises  control  (so  far  as  it  is  able). 
With  constant  plate  voltage,  cathode 
temperature  will  determine  the  current  up 
until  the  increased  space  charge  with 
increased  temperature  makes  the  hill  "too 
high"  for  the  plate  voltage  to  pull  electrons 
over.  With  constant  cathode  temperature, 
plate  voltage  will  be  the  ruhng  factor  until 
it  is  great  enough  to  pull  all  the  electrons 
over  the  hill,  at  which  time  temperature 
again  takes  over. 

This  "hiir'  effect  determines  the  maxi- 
mum power  dissipation  rating  for  Lhc  tube, 
in  a  slightly  indirect  manner.  The  *'hiir'  is 
hefM^een  cathode  and  pfate,  so  that  elec- 
trons leaving  the  cathode  must  '"chmb  up" 
the  hill  to  get  past  it^  and  those  which 
reach  the  plate  are  "falling  down"  the 
other  side.  (The  analogy  to  a  hill  is  not 
quite  real,  but  if  the  voltages  are  plotted  on 
B  graph  as  in  Fig.  2  it's  close  enough  for  all 
practical  purposes,) 

The  more  electrons  that  hit  the  plate,  or 
the  harder  they  fall,  the  more  shaken  will 
be  the  molecules  of  the  plate  material.  This 
shaking  up  of  molecules  is  what  we  gener- 
ally call  heat,  and  a  large  amount  of  it  goes 
on  in  a  typical  vacuum  tube.  Plates  often 
run  at  a  dull  red  glow,  and  some  lubes  are 
designed  to  operate  with  their  plates  white 
hot  -  with  the  heat  all  coming  from  the 
impact  of  the  electrons  falling  down  the 
'^voltage  hill"  between  cathode  and  plate. 

Any  material  eventually  gets  hot  enough 
to  melt,  and  the  plates  of  vacuum  tubes  are 
no  exceptions  to  this  rule.  For  this  reason, 
any  tube  is  rated  for  a  "maximum  plate 
dissipation"  which  is  the  power  in  watts 
tlie  plate  can  safely  convert  into  heat. 
Power  is  the  rating  factor  because  it 
includes  current  (the  number  of  electrons 
hitting  the  plate)  —  and  voltage  (the  hard- 
ness  with  which  they  fall).  It^'s  also  easy  to 
calculate  and  to  measuire,  in  operation. 

While  we've  explained  "power  dissipa- 
tion" ratings  in  terms  of  the  simple  diode, 
it's  the  same  situation  for  any  kind  of  tube. 
Not  only  the  plate  is  involved,  either.  Any 
electrode  which  is  more  positive  than  the 
cathode  (on  the  ""downhUr*  side  of  the 
voltage  hump)  must  dissipate  the  impact 
energy  of  the  electrons  that  get  to  it,  and 


78 


73  IVIAGAZINE 


such  electrodes  are  individually  rated  for 
maximum  power  dissipation. 

The  diode's  main  usefulness  in  radio 
today  is  as  a  polarity -sensitive  switch  (Fig, 
3),  If  the  plate  is  positive  to  the  cathode,  it 
conducts  a  current,  while  if  the  plate  is 
negative,    the    electrons   are    repelled    and 


e 


ciiRHEivrr 


MO  cunncNT 


A    A 


OUT 


Fig.  3,  Primary  use  of  diode  in  electronics  today 
is  as  a  switch.  When  plate  is  positive  (top)  current 
can  flow.  When  piate  is  negative  (center)  no 
current  flows.  This  action  can  be  used  to  change 
ac  input  into  pulsating  dc  output  f bottom),  or  to 
detect  the  envelope  of  an  ampUtude-modulated 
radio  signal,  as  well  as  for  many  more  exotic  uses 
not  strictly  a  part  of  radio. 


current  flow  stops.  This  makes  it  useful  as 
a  power  rectifier  to  change  ac  to  pulsating 
dc,  and  also  as  a  nonlinear  device  for 
modulation,  mixing,  and  detection  of  sig- 
nals (which  we'll  explore  later). 

The  first  great  advance  over  the  diode 
came  about  when  Lee  Deforest  sur- 
rounded the  cathode  with  a  coil  of  wire 
which  he  called  the  "'grid*'  (Fig.  4).  By 
applying  a  negative  voltage  between  the 
grid  and  the  cathode,  it  became  possible  to 
add  a  new  dimension  of  control. 

For  proper  operation  of  a  triode,  as  the 
three-element  tube  is  known,  cathode  tem- 
perature and  plate  voltage  are  kept  in  the 
range  where  plate  voltage  controls  cathode 
current-  The  plate  is  kept  positive  to 
permit  large  currents,  but  the  grid  is  kept 
negative  so  that  it  repels  electrons  from  its 
neighborhood  and  so  holds  down  the  plate 

current. 

The  effective  ''size''  of  the  grid,  as  it 
shows    up   in   its   interference   with   plate 


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DECEMBER    1970 


79 


current,  depends  upon  the  voltage  applied 
to  it.  The  more  negative  the  voltage,  the 
more  effectively  the  grid  blocks  current 
flow,  It*s  possible  with  most  tubes  to  bring 
plate  current  down  to  zero  by  putting  an 
extremely  negative  voltage  (known  as  "cut- 
off voltage")  on  the  grid.  If,  on  the  other 
hand,  the  grid  is  allowed  to  reach  a  positive 
voltage,  it  acts  just  like  another  plate,  and 
loses  its  control  of  current  flow. 

For  normal  amplifier  operation,  the 
*'bias"  voltage  applied  to  the  grid  is  some- 
where between  the  limits  of  cutoff  and 
positive  voltage,  and  is  chosen  so  that  the 
variation  in  plate  current  which  results 
when  small  changes  occur  in  the  grid 
voltage  is  a  reasonably  true  repljca  of  the 
variations  in  the  grid  voltage.  Picking  the 
right  combination  of  plate  voltage,  plate 
current,  and  grid  bias  to  achieve  this  happy 
effect  is  one  of  the  fine  points  of  engi- 
neering design  work  which  we  won*t  go 
into  deeply  right  here. 

For  our  purposes,  we  can  think  of  the 
tube  as  something  a  little  different.  As  we 
mentioned  in  our  previous  installment, 
either  a  tube  or  a  transistor  can  be  con- 
sidered to  be  just  a  resistor  in  the  circuit 
from  cathode  to  plate,  with  the  value  of 
the  resistor  being  controlled  by  the  grid 
voltage. 

This  is  a  somewhat  unconventional 
approach  to  the  matter  -  and  one  you 
won't  find  in  any  engineering  testbooks  — 
but  it  works.  Keep  in  mind  that  the  more 


PLATE 


S04EMATIC 

SYM80L 


^CATHODE 

Fig,  4,  Introduction  of  grid  between  cathode  and 
plate  made  it  possible  to  control  cathode  current 
by  means  of  a  separate  isolated  electrode j  and 
gave  birth  to  electronic  amplification  as  we  know 
it  today.  Appearance  of  simple  triode  is  shown  at 
left;  schematic  symbol  is  at  right. 


negative  the  grid-to-cathode  voltage,  the 
more  ohms  in  the  "resistor"  presented 
between  plate  and  cathode  connections, 
and  the  less  negative  the  grid,  the  fewer 
ohms  in  the  ^'resistor.'*  As  grid  voltage  goes 
positive,  then,  the  resistance  value  goes 
down  and  more  current  flows.  If  the  tube 
is  in  series  with  a  fixed  resistor,  this  will 
reduce  the  voltage  at  the  plate,  and  we 
have  a  change  in  plate  voltage  which  is 
brought  about  by  the  change  in  grid 
voltage  which  is  180  degrees  out  of  phase. 

When  used  in  this  manner  as  an  ampli- 
fier, the  triode  vacuum  tube  operates 
almost  exactly  like  the  transistor  except 
that  its  resistance  is  controlled  by  the 
voltage  on  its  grid  rather  than  by  the 
current  injected  into  the  base,  and  it  uses 
somewhat  higher  voltages  than  do  most 
transistors. 

However,  both  the  triode  and  the  tran- 
sistor share  a  common  problem.  The  grid 
and  the  plate  are  both  conductors,  and 
they  are  separated  by  an  insulating 
medium.  This  makes  them  form  a  capa- 
citor —  which  permits  some  of  the  plate 
voltage  to  feed  back  to  the  grid.  This 
plate-to*grid  capacitance  makes  the  triode 
tricky  to  handle  as  a  radio-frequency 
amplifier  (and  the  transistor  too,  for  that 
matter,  but  we're  talking  about  tubes  at 
the  moment). 

To  solve  the  problem,  another  grid 
structure  was  introduced  between  the  origi- 
nal  grid  (now  called  the  "control"  grid) 
and  the  plate*  The  new  grid,  being  added  to 
screen  the  control  grid  from  the  plate,  was 
called  the  "screen"  grid.  It  was,  like  the 
plate,  connected  to  a  positive  voltage  so 
that  it  had  little  or  no  effect  upon  the 
electron  stream  passmg  through,  but  was 
bypassed  through  a  capacitor  to  ground  to 
prevent  any  signal  from  coupling  back 
through  grid  -plate  capacitance. 

The  screen  grid  worked  nicely,  and  the 
resulting  structure  is  known  as  a  *'tetrode'' 
because  it  has  four  elements.  However,  it 
introduced  a  new  problem.  Sometimes  the 
plate  voltage  is  driven  to  a  value  lower  than 
the  screen  voltage.  Electrons  still  hit  the 
plate  hard  -  hard  enough  to  knock  a  few 
*'secondary**  electrons  free.  These  secon- 
dary  electrons   then   went   to   the  screen 


80 


73   MAGAZINE 


rather  than  returning  to  the  plate*  The 
result  was  an  effective  "negative  resis- 
tance" between  plate  and  screen  under 
certain  conditions^  which  could  cause  oscil- 
lation. 

The  direct  cause  o£  this  effect  was  the 
fact  that  the  screen  was  the  most  positive 
tiling  around  when  secondary  electrons 
were  released.  A  direct  cure  was  instal- 
lation of  still  another  grid,  the  third, 
between  screen  and  plate.  This  *'suppre- 
ssor"  grid  is  connected  to  the  cathode,  so 
that  it  will  be  more  negative  than  either 
screen  or  plate.  When  secondary  electrons 
leave  the  plate  now,  the  negative  charge  on 
the  suppressor  grid  drives  them  right  back 
where  they  came  from. 

With  five  elements  —  a  cathode,  three 
grids,  and  a  plate  -  the  resulting  tube  is 
known  as  a  pentode.  Most  present-day  rf 
amplifier  tubes  are  pentodes.  Some  power 
tubes  are  "beam  power"  tubes;  they  make 
use  of  special  beam- forming  plates  attached 
to  the  cathode,  which  focus  the  electron 
beam  in  such  a  way  as  to  create  a  ^'virtual 
suppressor''  by  space-charge  effect  between 
screen  and  plate* 

Each  of  the  additional  electrodes  intro- 
duces  a  small  amount  of  noise  into  the 
signal.  Normally  this  is  of  no  consequence , 
but  in  critical  applications  such  as  the  first 
stage  of  a  VHF  receiver,  triodes  are  still 
preferred  despite  their  problems  simply 
because  of  their  low  noise. 

The  many  other  kinds  of  tubes  you  may 
meet  are,  for  the  most  part,  combinations 
of  the  kinds  we've  examined  here.  They  all 
start  out  with  the  elements  of  a  diode,  and 
all  conventional  tubes  then  add  grids  as 
necessary  to  do  their  job.  Often  I  wo  or 
more  separate  tubes  are  combined  in  the 
same  enveiope  for  convenience  (the  6 USA 
(Fig,  5)  is  an  example  of  a  triode  and  a 
pentode  sharing  the  same  chunk  of  glass), 
but  the  essential  structure  remains 
unchanged. 

What  Factors  Limit  a  Vacuum  Tube's 
Usefulness? 

The  vacuum  tube  is  a  most  useful 
gadget,  but  each  individual  one  is  limited  in 
its  use  by  a  number  of  factors.  One  of 
these,    power    dissipation,    we've    already 


met.  Some  of  the  others  include  such 
tilings  as  the  circuit  efficiency,  operating 
frequency  limits,  and  power  requirements. 
The  major  limits  on  any  specific  tube 
are  those  set  by  its  power  requirements, 
power  dissipation  J  and  operating  frequency 
limits.  The  power  requirements  include 
both  the  power  necessary  to  heat  the 
cathode  and  that  required  to  operate  the 
tube's  plate  circuit  (and  screen,  if  any). 
Power  dissipation  involves  not  only  the 
ratings,  but  the  method  by  which  the  tube 
is  cooled.  Frequency  limits  are  usually 
one-sided.  Almost  all  tubes  will  operate  at 
frequencies  down  to  and  including  zero  (or 
dc),  but  every  tube  has  an  upper  frequency 
hmit  beyond  wliich  it  wUl  no  longer  act  as 
a  tube  should.  Let's  examine  these  in 
reverse  order,  looking  at  the  frequency 
limits  first. 

The  absolute  frequency  limit  in  any 
tube  is  set  by  the  physical  distance 
between  its  electrodes.  The  electrons  in  the 

tube  do  not  travel  at  the  speed  of  light; 
they  take  a  definite  amount  of  time  to 
make  the 'trip  from  cathode  to  plate.  If  the 
signal  frequency  is  so  high  that  the  distance 
from  cathode  to  plate  is  an  appreciable 
part  of  a  wavelength,  then  everything  goes 
sour.  For  instance,  a  positive-going  signal  at 
the  grid  should  increase  plate  current  —  but 
if  it's  a  half-wave  from  grid  to  plate,  the 
plate  current  will  be  decreasing  at  that 
instant  rather  than  increasing,  and  cannot 
increase  until  a  half-cycle  later  when  the 
grid  signal  is  going  negative. 

Almost  no  tubes  actually  make  it  up  to 
this  limit  J  though.  Other  factors  impose 
even  lower  frequency  limits  on  them.  One 
is    the    combined    effect    of   the   cathode 


6U8 


PINS  l,9,8H/2    6J6 
PINS  2/3,6,7  =  6 AG 5 


Fig.  5-  Combination  tube  such  as  type  6U8  is 
actuaUy  two  different  tubes  enclosed  in  same 
glass  envelope  and  sharing  same  heater  for  con* 
venience.  Triode  haff  of  6U8  is  same  as  half  a 
6J6t  while  pentode  portion  is  same  as  a  6AG5, 
Portions  can  he  used  independently. 


DECEMBER    1970 


81 


WHEN  IT  COMES  TO  ANTENNA  SYSTEMS...  IS  YODHS 

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structure's  own  inductance  and  the  capaci- 
tance from  cathode  to  each  other  element 
in  the  tube.  Taken  all  together,  these 
effects  add  up  to  a  low-pass  filter  circuit 
which  prevents  any  signals  above  the  fil- 
ter's cutoff  frequency  from  flowing 
through  the  cathode  —  and  so  makes  the 
tube  unusable  at   these  higher  frequencies. 


FILAMENT 
BUTTONS 


PLATE   RING 


GRID  RING 
CATHODE   RING 


Fig-  6,  In  quest  for  UHF  operation,  tube  design- 
ers have  come  up  with  strange  designs.  One  is  this 
"planar "  triode  which  is  made  of  ceramic,  with 
eiectrode  connections  coming  out  as  rings  around 
tube  body  to  eliminate  lead  inductance  as  much 
as  possible.  Tube  operates  well  into  UHF  region, 
but  still  has  an  upper  frequency  limit. 


Tube  designers  combal  these  limits  by 
making  tubes  intended  for  VHF  operation 
physically  small,  and  providing  multiple 
connections  for  all  elements.  An  extreme 
example  is  the  family  of  tiny  "'planar" 
iriode  tubes  made  for  space  use,  which 
have  no  connector  pins  as  such.  Instead, 
each  element  is  brought  through  the  envel- 
ope as  a  ring  (Fig,  6).  Distance  between 
elements  is  reduced  to  thousandths  of  an 
inch.  The  tubes  operate  far  into  the  UFIF 
region  —  but  they  still  do  have  frequency 
limitations. 

Power  dissipation  comes  about  because 
the  electrons  which  compose  the  cathode 


current  have  energy,  and  release  it  in  the 
form  of  heat  when  they  get  where  they're 
going,  as  we  already  saw.  The  limiting 
factor  here  is  almost  always  purely  physi- 
cal; when  things  get  just  so  hot,  they  melt. 
It*s  not  uncommon  to  see  overloaded 
power  tubes  with  large  dents  in  their  glass 
envelopes,  where  lieat  has  softened  the 
glass  to  such  an  extent  that  anything  can 
change  its  shape! 

The  type  of  cooling  provided  has  a  lot 
to  do  with  the  limiting  effects  of  power 
dissipation.  If  a  stream  of  cool  air  blows 
past  a  tube,  it  can  handle  much  more  heat 

than  if  it  is  sealed  into  an  airtight  box  of 

polished  aluminum.  Very-high-power  tubes 
are  often  liquid  cooled,  with  water  actually 
flowing  through  the  interior  of  the  plate 
structure  just  like  an  automobile  engine's 
cooHng  jacket.  Published  ratings  usually 
assume  good  ventilation  is  provided. 

Power  requirements  limit  the  usefulness 
of  tubes  in  a  number  of  ways,  most  of 
them  indirect.  In  comparison  with  a  tran- 
sistor, for  instance,  a  tube  requires  much 
more  power  —  so  much  so  that  the 
vacuum-tube  portable  radio  is  almost 
extinct  now.  More  power  is  necessary  for 
heating  the  filament  of  just  one  radio  tube 
than  is  used  by  all  the  transistors  of  an 
average  pocket  receiver. 

Similarly,  in  the  case  of  mobile  radio 
equipment,  those  tubes  which  require 
extremely  high  plate  voltage  supplies,  or 
high  current,  are  usually  ruled  out  because 
operating  power  is  limit ed. 

In  some  instances^  even  when  high 
voltage  and  high  current  are  available,  the 
comparative   danger  of  high-voltage  oper- 


82 


73   MAGAZilME 


ation  as  compared  with  low-voltage  circuits 
(transistors,  etc.)  tends  to  swing  the  choice 
away  from  the  tube. 

Circuit  efficiency  also  limits  the  useful- 
ness of  any  circuit,  not  just  those  using 
tubes.  In  general,  the  efficiency  of  any 
circuit  is  the  ratio  between  power  put  into 
the  circuit  and  power  taken  out.  For 
vacuum-tube  amplifiers,  it's  sliced  a  little 
thinner  in  the  standard  definition  of  plate 
circuit  efficiency, 

Plate  circuit  efficiency,  according  to  this 
definition,  is  the  ratio  of  signal  power 
output  to  supply  power  input  (Fig,  7)<  It 


SKiNJIL           ^ 

AMPLlHEII 
STAGE 

^SISNAL 

5J6NAL  OUT 

IN                     1 

OUT 

DC    INPUT 

1    1 
1    1 

1    t 
DC  \Hf^ 

UT 

EF¥. 


Fig,  7.  Efficiency  of  an  amplifier  or  a  circuit  is 

figured  as  shown  iiere,  by  dividing  signal  output 
power   by  dc  power  put  into   the  stage.   Input 

signal  power  is  ignored  in  the  calcuiation. 


has  nothing  to  do  with  signal  power  input. 
Thus,  an  rf  amplifier  which  operated  on  1 
kV  plate  supply  and  drew  500  mA  current 
would  take  500W  from  the  supply.  If  it 
delivers  300W  of  rf  output,  its  plate  circuit 
efficiency  is  60%, 

While  circuit  efficiency  up  to  95%  or 
better  is  possible  on  paper^  almost  no 
working  circuit  has  ever  been  buOt  which 
gets  better  than  75  to  80%  efficiency.  The 
trouble  with  the  higher  efficiencies  is  that 
they  measure  all  rf  power  output,  not  just 
that  at  the  signal  frequency >  In  order  to  get 
figures  above  75%,  it's  necessary  to  choose 
operating  conditions  which  greatly  increase 
the  percentage  of  harmonics  in  the  output 
—  and  all  the  "extra''  output  power  con- 
sists of  just  those  harmonics! 

Most  audio  power  amplifiers  are  far  less 
efficient  than  this.  Typical  figures  are 
around  20  to  25%  for  **moderate"  distor- 
tion. We'll  get  into  this  a  bit  more  a  little 
later  when  we  look  at  some  of  the  ways  in 
which  tubes  are  used. 

The  definition  of  plate  circuit  efficiency 
contains  a  built-in  loophole,  and  in  the 
early  days  of  SSB  operation   many  oper- 


ators took  advantage  of  the  same  loophole 
(which  was  also  in  the  FCC  rules  at  that 
time).  The  loophole  is  this;  signal  power 
input  is  not  taken  into  account. 

Some  types  of  amplifier  circuits  use 
only  a  small  fraction  of  the  input  signal  as 
input,  and  feed  the  rest  right  on  through 
into  the  output  circuit.  Such  an  amplifier 
can,  for  instance,  accept  lOOW  of  signal 
input  power,  amplify  1 OW  of  it  by  a  factor 
of  30  to  get  300 W,  and  feed  through  the 
remaining  90W  of  input  to  the  output.  The 
output  power  will  be  390W,  yet  the  ampli- 
fier produced  only  300  of  them.  If  input 
power  were  to  be  reduced  to  lOW,  output 
would  drop  only  to  300.  And  in  either  case 
the  dc  supply  power  taken  by  the  circuit 
would  be  the  same.  This  means  that  the 
same  circuit  might  produce  300W  at  an 
efficiency  of  60%,  or  390W  at  an  efficiency 
of  78%^  with  no  change  in  the  circuit  or  its 
adjustments! 

For  the  definition  of  efficiency,  this 
loophole  is  closed  by  requiring  that  only 
the  power  output  produced  by  that  circuit 
be  used  in  calculating  efficiency. 

The  loophole  in  the  rules  had  to  do  with 
the  maximum  power  limit.  It  was  originally 
stated  as  "1  kW  to  the  transmitter  stage 
which  delivers  power  to  the  antenna/*  and 
the  fellows  who  found  the  loophole  went 
through  it  by  using  a  1  kW  final  of  a  type 
which  could  feed  through  almost  unlimited 
power,  and  driving  it  with  a  10  kW 
"driver/'  Most  of  the  10  kW,  of  course, 
would  go  right  on  up  to  the  antenna,  with 
apparent  efficiency  in  the  final  of  several 
hundreds  of  percent. 

The  loophole  no  longer  exists.  Part 
97,67  of  the  current  edition  of  the  Rules 
and  Regulations  states  that  power  input 
shall  now  be  measured  to  **the  tube  or 
tubes"  delivering  power  to  the  antenna, 
and  the  Commission  has  served  notice  that 
in  the  case  of  feedthrough  amplifiers,  this 
is  interpreted  to  include  all  driver  stages  as 
well* 

How  Are  Vacuum  Tubes  Used? 

Wliile  at  first  glance  it  would  appear 
that  vacuum  tubes  are  used  for  many 
purposes,  we  can  compress  all  the  uses  for 
the  ordinary  garden  variety  of  tube  (that  is^ 


DECEMBER    1970 


83 


■■ 


all  except  such  special-purpose  items  as  TV 
picture  tubes,  oscilloscope  CRTs,  tuning 
indicators,  and  the  like)  into  one,  with  our 
**voitage-variable  resistance"  concept  intro- 
duced in  the  previous  section. 

The  diode  J  for  instance,  when  it  is  being 
used  as  a  rectifier,  changes  from  being  a 
very  high  resistance  (when  cut  off)  to  a 
relatively  low  resistance  (when  turned  on). 
The  amplifier  simply  controls  tke  flow  of 
current  between  two  terminals  in  response 
to  the  voltage  between  one  of  the  two  and 
a  third.  The  oscillator  is  simply  an  ampli- 
fier connected  in  a  special  circuit.  Even  the 
digital  logic  circuits  used  in  early  electronic 
computers  for  timing  and  storage  can  be 
viewed  as  resistances  controlled  by  volt- 
ages. 

The  exact  characteristics  of  any  indi- 
vidual type  of  tube  such  as,  for  instance, 
the  6C4  triodCj  depend  upon  the  materials 
from  which  it  is  made^  and  primarily  upon 
tlie  shape  and  spacing  of  its  electrodes. 

These  shape  and  space  factors  are  gener- 
ally called  the  "internal  geometry"  of  the 
tube  type,  and  they  fix  the  amount  of 
effect  the  grid  voltage  will  have  upon  plate 
current,  the  maximum  plate  dissipation, 
the  maximum  cathode  current^  etc. 

If  yoii  know  the  geometry  of  the 
tube  —  or  what  amounts  to  the  same  thing, 
know  what  its  effects  are  —  you  can  apply 
the  tube  in  almost  any  way  you  like.  To 
make  life  easier  for  equipment  designers, 
the  people  who  design  and  build  tubes  run 
measurements  upon  their  products  and 
pubUsh  "characteristic  curves"  which 
describe  the  key  factors, 

A  typical  characteristic  curve  for  a 
triode  (Fig,  8)  graphs  plate  current  against 


so 


lOO      r&O    200     250    300     350    400    450     SOO 
PLATE    VOLTS 


Fig.  fi.  Typical  set  of  plate-voliage/p}ate-current 
curves  for  a  triode  tube  shows  relation  of  plate 
miUiamperes  to  plate  volts  for  six  selected  values 
of  grid  vohage.  Relationships  for  other  grid 
voltages  must  be  interpolated  between  these,  if 
they  are  needed. 


plate  voltage  for  various  values  of  grid 
voltage.  A  not-so-typical  curve  might  graph 
plate  current  against  grid  voltage,  for  vari- 
ous plate-voltage  values.  For  most 
designers'  purposes,  though,  the  plate- 
current/plate-voltage  curve  is  best,  so  it's 
the  one  most  often  supplied, 

However,  if  we  know  plate  current  and 
plate  voltage  at  any  instant,  then  by  Ohm's 
Law  we  can  determine  the  effective  plate- 
to-cathode  resistance  represented  by  the 
tube. 

If  the  tube's  plate  is  working  into  a 
reactance  rather  than  a  resistance,  as  for 
instance  the  primary  of  a  transformer,  or  a 
choke-coupled  output  circuit,  the  plate 
voltage  averages  out  to  be  constant  and  the 
manufacturer's  curves  can  be  used  as  they 
are.  Changes  of  grid  voltage  then  change 
only  plate  current. 

If  the  plate  works  into  a  resistor,  as  in  a 
resistance-coupled  amplifier,  it's  "a  bit  dif- 
ferent and  the  picture  gets  messier.  A  "load 
line*'  must  be  drawn  on  the  curve  to 
determine  the  dc  plate  voltage  present  at 
any  instant. 

By  using  the  curves,  together  with  his 
accumulated  training  and  experience,  the 
equipment  designer  picks  an  "operating 
point"  for  the  tube  by  proper  choice  of  the 
plate  and  grid  voltages,  so  that  the  change 
in  grid  voltage  will  cause  a  corresponding 
change  in  resistance  between  plate  and 
cathode.  That  is,  if  a  0.5  V  increase  in  grid 
voltage  causes  a  10%  drop  in  resistance,  a 
IV  increase  of  grid  voltage  should  cause  a 
20%  resistance  drop  and  a  IV  decrease  at 
the  grid  should  result  in  a  20%  increase  of 
resistance.  These  figures  are,  of  course, 
merely  examples  and  do  not  correspond  to 
any  actual  circuit. 

When  this  had  been  done,  the  result  is  a 
circuit  which  produces  for  its  output  an 
**amplified'*  or  stronger  version  of  the 
input  signal.  The  "linearity"  of  amplifica- 
tion is  a  measure  of  how  accurately  the 
output  follows  the  input;  another  phrase 
used  for  the  same  effect  is  "distortion/* 

NQtice  particularly  that  this  same  pro- 
cess occurs  in  any  kind  of  amplifier  based 
on  tubes  or  transistors,  no  matter  what  the 
circuit's  name  may  be.  Class  A,  B,  or  C 
amplifiers,     as     well     as     grounded -grid, 


84 


73  MAGAZINE 


grounded-cathode,  and  cathode-follower 
circuits,  all  act  on  this  same  basic  process. 

The  terms  "class  A,"  "class  B,"  and 
"class  C**  describe  the  operating  point  of 
the  circuit.  A  "class  A"  circuit  is  intended 
to  produce  low  distortion,  and  to  give  an 
output  which  is  a  faithful  replica  of  the 
input.  A  class  B  circuit *s  operating  point  is 
much  closer  to  the  cutoff  point  (a  true 
class  B  circuit  operates  exactly  at  cutoff); 
output  is  distorted  but  efficiency  is  higher. 
A  class  C  circuit  remains  cut  off  most  of 
the  time  and  passes  current  only  during  the 
peaks  of  the  input  signal.  Output  is  dis- 
torted beyond  recognition  but  efficiency  is 
highest  under  these  conditions.  Since  the 
distortion  can  be  removed  from  a  continu- 
ous (unmodulated)  rf  signal  by  a  resonant 
circuit,  class  C  amplifiers  are  used  for  rf. 

As  we  have  already  learned,  any  circuit 
requires  two  conductors  to  complete  it;  we 
can  think  of  one  as  the  "hot"  lead  and  the 
other  as  a  "return"  path  for  the  current. 
The  usual  "return"  past  in  most  radio 
equipment  i^  the  chassis,  which  we  refer  to 
as  "ground"  or  "common"  since  it  h  often 
connected  to  ground,  and  provides  a 
common  return  for  all  signal  paths, 

Our  vacuum  tubes,  with  their  associated 
components,  convert  an  input  signal  into 
an  output  signaL  This  means  that  four 
conductors  are  involved,  two  for  each 
signaL  The  return  for  each  signal,  however, 
is  almost  invariably  grounded,  which 
reduces  the  number  of  conductors  to 
three  —  an  input  "hot"  lead,  an  output 
"hot"  lead,  and  ground.  This  is  fortunate, 
since  a  triode  tube  has  only  three  elements; 
we  have  exactly  enough  conductors  to 
assign  one  conductor  to  each  element:  with 
neither  elements  nor  conductors  left  over. 

Because  of  the  physical  means  by  which 
the  tube  does  its  job,  the  input  signal  must 
be  applied  between  grid  and  cathode,  and 
the  output  signal  must  be  taken  from  plate 

and  cathode.  However,  this  does  not  neces- 
sarily mean  that'  the  cathode  must  be 
connected  to  ground,  input  to  grid,  and 
output  to  plate. 

While  it's  true  that  the  most  conven- 
tional use  of  tubes  follows  just  that  assign- 
ment (called  grounded-cathode  operation), 
we   can  connect  our  common  ground   to 


any  one  of  the  three  elements  (Fig.  9).  If, 
for  instance,  we  ground  the  grid,  then  we 
must  apply  the  input  between  cathode  and 
ground.  In  order  to  take  output  with  only 
one  wire  at  the  plate,  we  must  pass  all  the 
output  current  through  the  input  circuit- 
That  is,  since  the  input  is  connected  to  the 
cathode,  the  output  signaTs  path  must  go 
through  the  input  to  get  to  the  cathode  in 
order  to  reach  the  plate. 

Similarly,  we  could  ground  the  plate* 
The  input  signal  is  now  applied  between 
grid  and  plate,  while  the  output  signal  is 
taken  from  cathode  and  plate.  For  the 
input  to  get  to  the  cathode,  it  must  travel 
through  the  output  circuit. 

Tliis  means  that  in  both  the  grounded - 
grid  and  the  grounded-plate  (usually  called 
cathode-follower)  circuits,  the  input  and 
output  circuits  are  directly  connected.  In 
the  grounded-grid  circuit,  they  are  in  series, 
so  that  all  the  current  of  one  must  pass 
through  the  other,  while  in  the  cathode 
follower,  they  are  in  parallel,  so  that  the 
voltage  of  one  becomes  the  voltage  of  the 
other. 


GROUNDED  cathode: 


GROUNDED  GRID 


OUT 


SIG 
OUT 


GROUNOED  PLATE 
(CATHODE   FOLLOWER) 


Fig.  9,  Differences  between  the  three  ways  of 
connecting  tubes  in  amplifier  circuits  are  shown 
here.  These  are  simplified  schematics  and  leave 
out  all  the  necessities  such  as  grid  bias,  coupling 
capaciiorSf  etc^  to  emphasize  the  similarities  and 
differences  of  the  three  different  circuit  types. 


DECEMBER    1970 


85 


^ 


Amateur  Radio  Operator 


c^  t  ten  tioit 


I 


Just  after  the  first  of  the  year 


CjaSmruoA^Mia 


will  have  something  of  interest  for  you, 
at  your  nearest  Ham  Radio  Supply  Emporium 
We'll  be  Celebrating .  . . 

Our  25th  Year. 

1946  to  1971 


In  the  conventional  grounded-cathode 
circuit,  the  input  and  output  circuits  are 
isolated  and  do  not  interact  so  directly. 

The  apparent  differences  between  these 
three  different  circuits  are  due  primarily  to 
this  difference  in  relationships  of  input  and 
output  signals.  In  the  grounded-grid  circuit, 
a  small  input  voltage  causes  a  large  change 
in  plate  current  —  which  forces  a  large 
change  in  input  current  because  of  the 
series  connection.  This  makes  the  circuit 
look  like  a  low  impedance  to  its  input,  and 
a  very  high  impedance  to  the  output.  It 
also  permits  feedthrough  of  power  from 
input  to  output. 

Since  it's  voltage  rather  than  current 
which  interacts  in  the  cathode  follower, 
the  effects  are  reversed.  Input  impedance  is 
very  high,  and  output  impedance  is  very 
low.  Coupling  of  signal  from  input  to 
output  is  small;  voltage  gain  is  always  less 
than  1,  which  means  that  a  cathode 
follower  actually  introduces  a  voltage  loss. 

The  gain  of  any  individual  tube  is 
determined  by  the  internal  geometry  of  the 


tube,  together  with  the  applied  voltages 
and  currents.  If  voltages  and  currents  are 
the  same,  the  tube  must  provide  the  same 
gain  in  any  of  these  three  circuits.  The 
stage,  however,  need  not  deliver  the  same 
gain. 

For  instance,  a  conventional  ground ed- 
cathode  amplifier  has  its  input  and  output 
circuits  separated  and  minimizes  inter- 
action between  them-  In  such  a  circuit,  the 
stage  gain  can  approach  the  maximum  of 
which  the  tube  is  capable.  Both  the  current 
and  voltage  of  the  input  signal  can  be  made 
larger  in  the  output. 

A  grounded-grid  stage,  however,  has  its 
input  and  output  circuits  in  series,  so  that 
the  output  current  and  input  current  must 
always  be  the  same.  Its  gain  can  affect  only 
the  signal  voltage.  Thus  the  current  gain  of 
the  grounded-grid  amplifier  cannot  exceed 
1,  but  high  voltage  gain  is  possible.  While 
the  gain  of  the  tube  itself  remains  high,  the 
interaction  between  input  and  output 
signals  outside  the  tube  reduces  stage  gain. 


86 


73   MAGAZINE 


The  cathode  follower  has  its  input  and 
output  circuits  effectively  in  parallel,  so 
that  the  voltage  in  an;out  must  be  approxi- 
mately the  same.  Its  gain  can  affect  only 
current.  Voltage  gain  cannot  be  greater 
than*  1,  but  high  current  gain  is  possible- 
Again,  the  tube  gain  is  unchanged,  but  the 
input/output  interaction  outside  the  tube 
provides  the  restricting  factor. 

Since  both  the  grounded-grid  and  the 
cathode-follower  circuits  produce  less  gain 
than  does  the  groundcd-cathode  arrange- 
ment^ and  since  amplifiers  are  usually 
intended  to  produce  gain^  this  gives  rise  to 
the  question  "Why  use  these  inefficient 
circuits?" 

Each  of  them  has  its  own  unique 
properties^  which  provide  certain  advan- 
tages in  special  situations.  When  the 
properties  are  not  needed,  the  special 
circuits  aren't  used. 

The  grounded-grid  amplifier  reduces  the 
stray  coupling  between  input  and  output 
circuits  inside  the  tube,  because  the  grid 
acts  as  a  sliield  between  cathode  and  plate. 
This  makes  it  possible  to  avoid  having  to 
"neutralize"  a  high-frequency  amplifier^ 
and  in  some  cases  makes  it  possible  to 
operate  a  given  tube  at  a  higher  frequency 
than  would  otherwise  be  possible  (by 
modifying  the  effect  of  the  built-in  "low- 
pass  filter"  we  examined  earlier). 

In  addition,  the  low  input  impedance  of 
the  grounded-grid  circuit  is  often  con- 
venient for  a  high-power  rf, amplifier,  and 
the  capability  of  feeding  througli  power 
from  input  to  output  is  also  nice  (although 
no  longer  offering  a  loophole  in  the  FCC 
regulations). 

Contrary  to  popular  opinion,  there  is  no 
appreciable  difference  in  amplification 
quality  between  a  grounded -grid  amplifier 
and  one  using  the  conventional  grounded- 
cathode  circuit.  Quality  in  each  case 
depends  upon  proper  adjustment  of  oper- 
ating point  and  input  signal  level,  not  upon 
the  choice  of  the  common  electrode. 

The  cathode  follower's  special  proper- 
ties depend  upon  its  high  input  impedance 
and  low  output  impedance.  This  makes  it 
ideal  for  use  in  transforming  impedances 
from  high  to  low  levels.  The  input  capaci- 
tance is  reduced  by  the  same  factor  that 


input  resistance  is  increased,  making  the 
cathode  follower  an  excellent  device  for 
coupling  energy  out  of  critical  circuits  such 
as  rf  oscillators.  The  low  output  impedance 
makes  it  capable  of  driving  a  feedline 
without  any  intervening  transformer, 
although  other  factors  make  this  idea  less 
attractive  than  it  may  sound  at  first. 

The  cathode  follower  offers  an  ideal 
example  of  "feedback"  in  action;  this  is  an 
important  idea  iii  aU  electronics^  and 
seldom  appears  so  clearly  illustrated  as  in 
the  cathode  follower.  Let's  take  a  conven- 
tional grounded-cathode  circuit  and  change 
it,  step  by  step,  into  a  cathode  follower  to 
see  how  feedback  provides  all  the  special 
characteristics  of  the  cathode  follower 
while  the  tube  itself  continues  to  operate 
just  as  it  did  before. 

We'll  start  with  an  imaginary  triode 
which  operates  normally  with  a  plate-to- 
cathode  potential  of  lOOV,  a  cathode-to- 
grid  potential  of  5  V,  and  a  plate  current  of 
10  mA.  Under  these  conditions,  with  a  10 
klZ  resistor  as  its  load,  the  tube  provides  a 
voltage  gain  of  21  times  (Fig.  10).  That  is, 
a  0.1  V  change  In  grid  voltage  will  change 
the  plate  current  by  210  /iA,  causing  the 
plate  voltage  to  change  by  2.1V*  A  IV 
change  in  grid  voltage  will  change  plate 
current  by  2,1  mA,  causing  a  plate  voltage 
change  of  2 1 V, 

Now  let's  move  1  kO  of  the  plate  load 
resistor  around  to  the  cathode  cu-cuit, 
leaving  9  kf2  in  the  plate  lead  (Fig.  1 1 ). 
This  1  kfi  in  the  cathode  circuit  is  in  both 
the  cathode—grid  circuit  and  in  the  platen- 
cathode  circuit,  so  that  the  plate  path  still 
sees  10  kn. 

If  we  change  the  grid  voltage  by  1 V,  the 
plate  current  will  change  by  2,1  mA.  This 
will  increase  the  cathode  voltage  by  2.1V 
(if  the  grid  is  going  positive  so  that  the 
current  increases)  and  decrease  the  plate 
voltage  by  18,9V-  The  plate— cathode  volt- 
age change  is  still  21 V.  The  output  voltage 
change  would  be  less  than  that,  however, 

Unfortimately,    the    2,1V    change     in 
cathode  voltage  is  of  such  a  polarity  as  to 

reduce  the  effect  of  the  IV  input  signal; 
were  the  entire  2J  V  increase  to  occur,  it 
would   completely  cancel  the  input  signal 


DECEMBER    1970 


87 


mi 


21  X  IN 


10  K 


+  200 


J^+2J 


FtG.  10 


+  102  J 

100V>9000 


7x  IN 


+  200 


1000 


FIGM1 


+  150 


1.83  X  IN 


+50  +200 

0-91  K  IN     ^^ 


+200 


0.95  X  IN 


+ 105 


FIG.  12 


FIG.  13 


Figs.  JO— 13.  These  four  schematics  iilustrate  how  feedback  introduced  by  resistance  in  cathode 
circuit  reduces  stage  gain  although  tube  itself  continues  to  operate  unchanged.  Voltage  applied  £o 
grid  maintains  grid-to-cathode  voltage  at  5;  as  cathode  voltage  changes,  grid  voltage  is  changed  to 
always  be  5V  less. 


which  produced  it.  This,  of  course,  cannot 
happen.  What  does  happen  is  this: 

The  effective  input  signal  is  the  one 
between  grid  and  cathode,  while  the  actual 
Input  signal  is  between  grid  and  ground. 
When  the  grid  voltage  goes  up  IV,  it 
cannot  do  so  instantly  but  must  increase  a 
few  millivolts  at  a  time.  As  it  does  so,  the 
cathode  voltage  comes  right  along  behind 
to  buck  it  —  and  at  some  point  they  meet 
and  level  off  so  that  IV  applied  between 
grid  and  ground  produces  a  grid-to-cathode 
voltage  just  right  to  permit  the  cathode- to- 
ground  voltage  at  that  instant. 

In  our  example,  this  wlli  happen  when 
the  grid -cathode  voltage  is  a  little  higher 
than  0.322V.  The  cathode  current  increase 
caused  by  this  voltage  is  a  little  more  than 
0.67  mA,  and  the  rise  in  cathode  voltage  is 
about  0,676V,  The  two  voltages  add  up  to 
0:998  —  which  would  have  been  LO  except 
that  we  rounded  off  our  figures. 

The  "feedback**  voltage  appearing 
across  the  cathode  resistor^  then,  reduced 
the  effective  input  voltage  to  a  smaller 
value.    This    in    turn   reduces   the   output 


signal  voltage,  since  there  is  less  input 
signal  available  to  the  grid.  Stage  gain  is 
reduced  -  but  the  tube  itself  is  still  pro- 
viding a  2  1-time  voltage  gain- 
Input  resistance  of  the  stage  increases, 
because  resistance  is  defined  as  voltage 
divided  by  current  (Ohm's  Law).  Only  the 
effective  input  voltage  sees  the  original 
stage  input  resistance,  but  the  entire  input 
signal  is  affected.  Tliis  means  that  the 
original  input  resistance  must  be  multiplied 
by  the  same  value  that  the  voltage  is 
divided  by  in  order  to  keep  current  con- 
stant. In  our  example^  the  effective  voltage 
is  about  a  third  of  the  actual  voltage,  so  the 
effective  input  resistance  is  three  times  that 
of  the  original  circuit. 

Now  let's  move  some  more  of  the 
resistance  from  the  plate  circuit  to  the 
cathode  (Fig.  12).  This  time,  let's  make  it 
50/50,  with  5  kU  in  each. 

The  feedback  causes  the  effective  signal 
input  voltage  to  be  smaller  than  the  actual 
input,  just  as  before,  only  more  so.  Where 
in  our  first  example  the  cathode  voltage 
rose  2,1    for  every  volt   increase  in  grid  — 


88 


73  MAGAZINE 


1 

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MODELS 


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with  the  t-JLajJDiJu  BEARCAT 

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Fire.  Civil  Defense,  Marine,  Weather,  Utititles,  Business,  etc.  Stops 
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mobfie,  relay  and  repeater  stations.  AM  aircraft  band  model  also  avail- 
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ELECTRA    CORPORATION    *    CUMBERLAND,    IND,    46223 


cathode  voltage,  it  will  now  rise  10.5 
because  of  the  greater  resistance. 

Effective  stage  gain  under  these  condi- 
tions is  reduced  from  21  times  to  about 
1.83  times.  That  is,  a  IV  input  signal  frpm 

grid  to  ground  will  produce  an  apparent 
K83V  change  in  plate  voltage -- which 
means  a  183  juA  change  in  ptate  current. 

This  means  that  the  increased  cathode 
resistance  caused  the  leveling-off  to  occur 
with  an  effective  input  voltage  of  only 
about  0.087V.  The  remaining  0.9 13V  of 
the  input  signal  was  bucked  out  by  cathode 
voltage- 
Input  resistance,  similarly,  is  much 
greater  now. 

If  we  move  all  10  kH  over  to  the 
cathode  circuit  (Fig.  13),  we  find  that 
effective  stage  gain  is  down  to  21/22,  That 
is,  a  1  V  input  signal  will  cause  a  0.954V 
change  in  cathode  voltage.  The  effective 
input  between  grid  and  cathode,  then,  is 
only  about  0.05  V.  The  tube  is  still  pro- 
ducing its  2I-time  gain,  because  0.05  times 
21  is  1.05  factually  the  input  is  a  little  jess 
than  0.05.  providing  0.95V  out).  Input 
resistance  is  now  21  times  larger  than 
originally. 

The  cathode  follower  circuit  we  have 
just  developed  can  accept  much  larger 
input  signals  than  could  the  grounded- 
cathode  circuit  with  which  we  began.  For 
instance,  we  had  a  5V  bias  on  the  grid  at 
the  beginning,  which  meant  that  any  input 
signal  more  positive  than  5V  would  carry 
the  grid  positive  (a  condition  to  be  avoided 
in  most  cases).  With  the  approximate 
20-time  division  of  actual  input  voltage 
produced  by  the  cathode  follower's  feed- 
back,   a    5V    input    signal    is    effectively 


reduced  to  0.25V,  and  even  a  20V  input 
signal  is  effectively  cut  back  to  IV  from 
grid  to  cathode. 

Where  originally  we  ran  out  of  the 
operating  range  with  a  5V  signal^  we  can 
now  go  up  to  a  lOOV  signal  without 
exceeding  the  same  operating  limits. 

This  is  not  the  only  advantage  produced 
by  controlled  feedback.  The  changes  in 
input  and  output  impedance  are  also  due 
to  feedback's  modification  of  effective 
voltage  and  current  levels.  Not  so  obvious 
is  the  fact  that  any  distortion  introduced 
by  the  tube  is  reduced,  because  it  is  not  a 
part  of  the  original  input  signal. 

The  grounded-grid  amplifier's  character- 
istics of  low  input  impedance  and  high 
oulput  impedance  are  also  the  result  of 
feedback;  in  the  grounded-grid  circuit,  it  is 
current  that  feeds  back  rather  than  voltage, 
and  this  reverses  the  effect  upon  imped- 
ances. 

Feedback  also  makes  oscillation  possi- 
ble, if  the  feedback  voltage  boosts  the 
input  signal  rather  than  bucking  it.  We'll  go 
into  all  this  in  another  chapter,  however, 
when  we  examine  practical  amplifiers  and 
transmitter  circuits. 

A  Place  to  Start 

By  this  time,  w^'ve  fairly  well  covered 
the  basic  components  and  ideas  upon 
which  electronics  and  radio  theory  are 
built-  With  our  foundation  estabhshed, 
we're  ready  to  begin  putting  things 
together  into  operating  circuits.  One  thing 
which  any  circuit  must  have  is  a  source  of 
power,  so  the  power  supply  is  a  good  place 
to  begin  our  study  of  practical  circuit 
theory*  .  . .  Staff  ■ 


i 


DECEMBER    1970 


89 


NEW   PRODUCTS 


Crystal-Controlled  Microcircuit 


A  crystal-controlled  microcircuit  oscil- 
lator (Model  MCO-F),  which  uses  thin-film 
capacitors  and  resistors  on  a  single  sub- 
strate, is  totally  contained  within  a  4-lead 
TO-5  Koldweld  package.  The  new  unit  is 
designed  for  application  as  the  local 
oscUlator  or  second  mixer  in  dual- 
conversion  receivers,  ft  is  especially  suited 
for  use  in  advanced  paging  and  personal 
portable  receivers  where  rugged  environ- 
mental conditions  may  be  encountered. 
TRW  Electronics,  1 1 00  Glendon  Ave.,  Los 
Angeles  CA  90024. 

IC  Breadboard  Socket 


A  new  device  is  now  available  for 
bread  boarding  with  12-Iead,  round  TO-5 
integrated  circuits.  The  device  consists  of 
an  epoxy  glass  wafer,  2-3/8  x  1-5/8  in.,  on 
which  is  mounted  a  12-pin  socket,  the  tabs 
of  which  have  been  soldered  to  two 
adjacent  rows  of  reliable  solderless  termi- 
nals. 


The  device  should  speed  IC  breadboard- 
ing  because  as  many  as  four  solderless 
connections  can  be  quickly  made  to  any 
terminal  pin  with  ordinary  hook-up  wire.  If 
discrete  components  are  required,  they 
may  also  be  easily  connected.  Vector 
Electronic  Co.,  12460  Gladstone  Ave,, 
Svlmar  CA  91342. 

Power  Transistor  Line  Expanded 


Four  new  transistors  have  been  added  to 
the  industry's  only  line  of  silicon  PNP  rf 
power  devices.  The  transistors,  types 
MM4020  thru  MM4023,  bring  to  nine  the 
number  of  devices  in  Motorola's  PNP  rf 
power  family  and  increase  the  variety  of 
output  powers  available  to  the  designer. 
These  now  range  from  0,5 W  to  40 W  @  175 
MHz, 

Each  of  the  transistors  features  bal- 
anced-emitter construction  for  maximum 
safe  operating  area,  isothermal  design  for 
flat  power  output  versus  temperature 
performance,  and  low  lead  inductance 
striphne  packaging. 

The  transistors  are  designed  for  the 
12.5V  VllF  large-signal  amplifier  amplifica- 
tions required  in  military  and  industrial 
equipment  operating  at  frequencies  up  to 
250  MHz. 

In  the  unusual  construction  used  for  the 
four  new  transistors,  thin-film  Nichrome 
resistors  in  series  with  each  of  the  multiple 
emitters  distribute  power  evenly  through- 
out the  chip.  This  technique  prevents  **hot 
emitters*'  and  results  in  maximum  safe 
operating   area   and    a  rugged  device   that 


90 


73  MAGAZINE 


stands  up  under  the  high  voltage  standing 
wave  ratio  conditions  sometimes  occurring 
in  a  mistuned  rf  system. 

The  MM4020/2 1/22/23  transistors  bring 
another  important  characteristic  to  the  rf 
designer  —  exceptional  output  power 
stability  versus  temperature  —  through  the 
use  of  isothermal  design.  This  type  of 
transistor  design  insures  the  even  genera- 
tion and  flow  of  heat  in  and  from  the  chip 
so  that  the  "power  slump"  usually 
encountered  in  an  rf  power  device 
operating  near  its  maximum  frequency  is 
nearly  absent.  Motorola  Semiconductor 
Products  Inc.,  Box  20924,  Phoenix  AZ 
85036. 

Amplifier  Modules  in  Semi-Kit  Line 


Eight  different  special  and  general- 
purpose  audio  amplifier  modules  are  being 
offered  by  GC  Electronics  Division  of 
Hydrometals,  Inc.,  as  part  of  its  new 
Calectro-Amperex  line,  Basic  module 
shown  here  is  a  20-watt  stereo  amplifier, 
which  is  blister-packed  and  displayed  on  a 
pegboard  rack.  The  line  also  includes 
lower-power  hobbyists'  amplifiers  and 
guitar  amplifiers,  along  with  a  profession- 
ally finished  universal  chassis/ cabinet  kit, 
Ivens  Stanton  Assoc,  122  East  42nd  St., 
New  York  NY  J 001 7, 

Miniature  FM  Mobile  Unit 

The  Regency  solid  state  Model  HR-2 
features  a  lOW  of  rf  power  output  with 
operation  on  any  of  12  transmit  and 
receive  channels.  The  receiver  section  of 
the  new  radio  is  double  conversion,  super- 
heterodyne with  a  highly  selective  ceramic 
filter  for  operation  on  both  wide  and 
narrow  band  signals.  Sensitivity  is  rated  at 
0.35  juV,  20  dB  quieting.  The  transmitter 
features    phase    modulation    for    exacting 


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In  100  ft.  interconnected  coils 

18  Copperweld,  Per  100  feet ...-,*.$   1.19 

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AN  major  lines  Of  Amateur  gear—  Rohn  #25  towers 
and  accessories  —  Coaxial  switches—  Dow  Key 
relays  -  Greene  Baiuns  -  New-Tronics  Hustler 
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Please  Include  Postage 

CQNMECTICUTS  OLDEST  HAM  STORE  I 

U«  ••••••  ••••••«! 


DECEMBER    1970 


91 


1 


carrier  stability.  Individual  trimmer  capaci* 
tors  enable  frequency  netting  for  optimum 
performance  in  point-to-point  or  repeater 
applications.  Built-in  swr  load  mismatch 
circuitry  protects  against  open  or  shorted 
antenna  conditions. 

The  IVa  X  5Vi  x  IVz  in,  package  comes 
complete  with  plug-in  ceramic  microphone, 
built-in  speaker,  and  mobile  mounting 
bracket-  One  pair  of  factory  installed 
transmit  and  receive  crystals  on  146.94 
MHz  are  included  in  the  $229  amateur  net 
price.  Regency  kicctroiiics,  7900  Pendle- 
ton Pike,  Inifiana polls  IN  46226. 

High  Power  on  450  MHz! 

Requiring  only  8-lOW  of  rf  input 
power,  the  Alpha  PA-100  UHF  amplifier 
will  achieve  a  power  output  of  lOOW. 
Designed  for  fixed  base  station  or  repeater 
use  in  the  450  MMz  band,  this  compact 
unit  has  a  self-contained  solid-state  power 
supply,  no  electromechanical  moving  parts, 
and  requires  only  5V^  in,  of  rack  space.  The 
true  integrated  coaxial  plate  cavity  con- 
struction assures  high  plate  efficiency  and 
low  plate  operating  temperature,  making 
possible  continuous-duty  use  while  assuring 
long  component  life.  The  grid  input  circuit 
works  to  suppress  harmonics  generated  by 
the  input  transmitter,  thus  reducing  the 
problem  of  inlermod.  The  PA-100  is  said 
to  be  easy  to  install  and  is  ideal  to  upgrade 
existing  low-power  repeaters  or  base  trans- 
mitters. Alpha  Electronic  Services.  S43! 
Monroe  Ave.,  Stanton  CA  90680. 

High  Power  on  2  FIVI 

The  new  ''22'er  FM''  by  Clegg  features 
60W  of  rf  input  power  plus  a  highly 
sensitive  TUNABLE  receiver-  Ten  crystal- 
controlled  channels  are  available  for  trans- 
mit. Made  in  the  United  States.  Clegg 
Associates,  hu\,  Littell  Road,  East  Hanover 
NJ  07936. 

Solid  State  Transmitter-Receiver 

Another  2  meter  FM  transceiver  has  just 
been  introduced  to  the  amateur  scene.  The 
unit  sells  for  S250,  has  a  5W  transmitter, 
6-channel  receive-transmit,  FET  front  end. 
The  i-Fs  and  af  circuits  are  IC,  ajid  the  unit 
comes    with    two   installed    channels   (.94 


direct  and  J4-.94),  A  front  panel  meter 
indicates  signal  strength  and  rf  output 
relative  power.  Price  includes  mike, 
bracket,  and  dc  power  cable.  Te  leva  mm. 
Box  461.  Cupertino  CA  95014. 


PhaseLockedLoop  Linear  IC 

Two  new  ^*^phase~locked  loop*'  linear 
integrated  circuits  are  ideally  suited  for 
such  applications  as  accurate  multiplication 
and  division  of  frequencies  virtually  in  any 
ratio,  according  to  Anliur  E,  Fur\\ 
Manager  of  Linear  Product  Marketing. 
Range  of  operation  extends  from  suhaudio 
frequencies  to  VHP, 

**These  units  are  unique  in  the 
industrJ^"  Fury  said,  "because  they  are 
designed  to  perform  mathematical  func- 
tions that  are  quite  impractical  with  digital 
circuits.  Our  devices  can  multiply,  divide, 
and  even  fractionalize  frequencies  virtually 
in  any  ratio.  For  example,  they  can  divide 
a  fundamental  trequency  by  10/3,  if 
desired,  a  process  which  is  virtually 
impossible  with  digital  devices/' 

Operating  range  of  the  562,  a  model  of 
the  device  fabricaled  with  a  dielectric 
isolntion  process,  is  0.1  Hz  to  more  lliim  50 
MHz,  The  562  chip  is  67  by  75  mils  in  size* 
Signetics  engineers  designed  the  two  new 
phase-locked  loop  circuits  in  direct 
response  to  comments  received  on  the  first 
PLL  linear  circuits  which  were  introduced 
by  the  company  several  months  ago,  *'We 
have  added  a  number  of  features,"  Fury 
said  J  ''which  makes  the  phase-locked  loop 
more  useful  for  specific  applications.  Most 
important  among  the  features  is  that  we 
have  opened  the  loop  and  provided  connec- 
tions that  permit  the  insertion  of  external 
devices  into  the  loop  circuit," 

Four  separate  sections  comprise  each 
device:  a  phase  comparator  that  also 
operates  as  a  multiplier  and  mixer,  a 
low-pass  filter,  an  error-signal  amplifier, 
and  a  voltage-controlled  oscillator.  The 
loop  circuit  has  been  opened  between  the 
VCO  and  the  phase  comparator. 

Additional  information  is  available  from 
Sign  erics  Corp,,  811  East  A  rq  ues  A  re. . 
Sunnyvale  CA  94086. 


92 


73   MAGAZINE 


Low-Harmonic  High-Povuer  Linear 

Raytrack  Company  of  Columbus,  Ohio 
is  introducing  its  new  lowband  linear 
amplifier,  the  DX2000L.  This  amplifier  has 
an  input  capability  of  2  kW  PEP  SSB,  and 
I  kW  AM,  CW,  and  RTTY,  and  is  for 
operation  on  the  80-10  meter  bands.  The 
DX  2000L  is  the  first  high-power  linear 
amplifier  to  use  a  hybrid  tank  circuit 
(Raylrack's  unique  toroid  and  air  inductor 
combination).  This  system  gives  the 
DX2000L  extraordinarily  high  efficiency 
on  all  of  the  80—10  meter  bands,  and,  in 
combination  with  the  pretuncd  toroid 
input  makes  this  amplifier  far  less  prone  to 
radiate  TVI,  according  to  the  manufac- 
turer. 

Two  zero-bias  triodes  (EIMAC  3— 500Z) 
are  operated  in  class  B  and  are  preneutral- 
ized  for  maximum  stability.  Other  features 
include:  an  adjustable  ale  output  (negative 
feedback)  that  is  compatible  with  all 
standard  equipment;  an  exciter  feed- 
tin  o  ugh  that  eliminates  the  need  for 
additional  relays  to  operate  the  exciter 
only;  precision  taut-band  meters:  and  a 
very  handsome  case.  The  DX2000L  has  a 
separate  power  supply  that  is  included  in 
the  price.  Raytrack  Co,,  Columbus  OIL 

Hybrid  Povuer  Amplifier 


TRW  Semiconductors  announces  the 
addition  of  the  HMD  2000  hybrid  power 
amphfier  to  their  microelectronic  product 
line.  This  amphfier  can  be  operated  in 
either  a  linear  or  switching  mode  willi 
capabilities  of  delivering  3 A  peak  current 
for  power  supplies  to  ±25  V.  Mounted  in  a 
TO-3  package,  it  is  ideal  for  a  broad  range 
of  appHcations  including  switching;  class  B 
servo;  hi-fi  audio  amplifiers,  and  motor 
drivers.  Power  amplifier  is  priced  at 
SI 0.50.  TRW  Semiconductor  Diw^  14520 
Aviation  Blvd.,  Lawndale  CA  90260. 


SERVICE  AND  FRIENDUNESS 

To  Radio  Amateurs  For  32  Years 

WE  MUST  BE  DOING  SOMETHING   RIGHT. 


RECEIVER  TUNING  OPTIONS 


PHONE 

510-842 

8350 


In 


The  Clegg  22'er  FM  \s 
now  availabte  with  two 
RECEIVER  TUNER 
choices: 

Series     24:      Full     2 

meter     band     coverage 

from     143.4    to     148,3 

100    kHz    increments    and 


MHz.     Calibration     is 
readable  to  25  kHz. 

Amateur  Net  Price  of  the  24  Series  units  *s  $369.95 
with  Transmit  crystal  for  146.94  and  PTT  micro- 
phone. 

Series  2S:  Restricted  coverage  from  145. 9  to  148.2 
MHz  with  the  tuning  dial  calibrated  in  30  kHz 
"channer^  designations. 

Amateur  Net  Price  of  the  25  Series  unit  is  $384.95 
with  th#  same  accessories.  The  25  Series  units  also 
include  a  steeper  skirt  ceramic  filter  in  the  IF  stages. 
ADDITIONAL  TRANSMIT  CRYSTALS  can  be  fur- 
nished {.0005%  tolerance  from  1  to  40  degrees  C 
ambient)  at  $9.00  each.  All  standard  30  KG  increment 
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con  be  supplied  by  Sentry  Mf§.  Co.,  Crystal  Park, 
Chrckasha,  Oklahoma  73018.  Order  their  Stock  No, 
88001  plus  desired  output  frequency. 

Just  off  Exit  27  on  Thruway 

Distributors  of  all  major  lines 

of  amateur  equtpment. 

185  WEST  MAIN.   AMSTERDAM.   N.Y,   12010 


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1003  SOUTH  FIRCROrr  STREET 
WEST  COVINA.  CALIFORNIA  91791 


I 


DECEMBER    1970 


93 


Yipes,  It  Talks 


f 

i 


W.  Edmond  Hood  W2FEZ 

116  W.Park  Street 
Albion  NY  11411 


1  shall  never  forget  one  Hallowe'en,  long 
ago  when  1  was  a  neophyte  in  electronics. 
My  dear  old  grandmother,  God  rest  her, 
came  into  the  parlor  ready  to  settle  down 
with  a  good  bloody  murder  mystery.  It  was 
quite  late  and  the  whole  family,  she  thought, 
was  sound  asleep.  She  switched  on  the  light. 

^*Good  evening/* 

Grandma  jumped  back.  Then,  getting  a 
grip  on  her  nerves^  she  quickly  checked  the 
closet,  looked  under  the  couch  and  behind 
the  curtains.  She  was  quite  alone  in  the 
room. 

"What  'cha  looking  for?"  It  seemed  to  be 
coming  from  the  coffee  table.  An  old  news- 
paper lay  innocently  on  the  table.  Grandma 
adjusted  her  glasses,  bent  over  the  table  and 
scrutinized  the  paper.  She  was  breathing 
rather  hard, 

"Lady,  you  really  ought  to  do  something 
about  those  adenoids/* 

Grandma  jumped  back  as  if  she  had  seen 
a  rattlesnake.  "It  talked,"  she  gasped,  "The 
d^ thing  talked!'' 

"So,  what^s  wrong  with  that?  Do  I  get  all 
shook  up  when  you  talk?" 

Grandma  was  completely  befuddled  by 
now.  The  last  remaining  black  hairs  on  her 
head  had  just  turned  snow  white.  Then  a 
strange  thing  happened.  She  shrugged  her 
shoulders,  set  her  mystery  aside,  and  began 
to  talk.  Of  course  she  never  told  anybody 
about  the  conversation,  but  she  confided 
with  the  newspaper  that  she  hadn't  had  such 
an  enjoyable  conversation  in  ages.  The  two 


of  them  chatted  together  until  the  wee  small 
hours, 

I  never  had  the  courage  to  confess  to 
Grandma  that  I  had  been  the  culprit,  A  few 
times  after  that,  when  she  thought  she  was 
alone,  she  tried  to  strike  up  a  conversation 
with  other  newspapers^  but  none  of  them 
were  anywhere  near  as  sociable  as  that 
Hallo  we  *en  issue. 

Since  I've  already  mentioned  that  1  had 

been  the  culprit,  you've  probably  guessed 
that  there  was  a  loudspeaker  concealed  in 

the  room.  Not  exactly.  The  secret  really  lay 
in  the  newspaper.  If  grandma  had  picked  it 
up,  she'd  have  caught  on  right  away.  For- 
tunately for  me,  she  was  far  too  polite  to  lay 
hands  on  her  guest. 

It's  really  a  pretty  simple  thing  to  rig.  All 
you  need  is  a  copy  of  the  DaOy  Dirt  and  a 
package  of  aluminum  foil.  Open  up  a  full 
sheet  and  spread  a  strip  of  the  foil  inside  it. 
Fold  the  sheet  over  and  lay  another  strip  of 
foil  on  top.  When  you  fold  the  sheet  again,  if 
you've  done  it  right,  the  foil  should  be 
completely  concealed  and  the  paper  should 
look  the  same  as  it  did  when  it  was  on  the 
news  stand.  The  two  pieces  of  foil  should  be 
insulated  from  one  another  by  the  paper.  In 
other  words,  the  whole  business  should  look 
like  a  big  capacitor.  The  next  step  is  to  wire 
it  up,  but  before  we  do,  let*s  take  a  look  at 
how  and  why  it  works, 

I  said  before  that  it  is  a  big  capacitor.  I 
can  qualify  that  slightly  and  say  that  actual- 
ly  it   is   an   electrostatic   loudspeaker.   The 


94 


73  MAGAZINE 


audio  signal  is  impressed  between  the  two 
foils.  Since  two  oppositely  charged  objects 
attract  each  other,  and  since  the  audio  signal 
consists    of   a    varying    voltage,   there   is   a 


o 


OPEN      VQfQt    COrL 
^CIRCUIT    HEPE 


e 


3K 


\ 


/77 


Fig.  L  Method  of  connecting  electrostatic  speak- 
er to  vacuum  tube  outpuL 


varying  attraction  between  the  plates.  The 
plates,  in  this  case  the  foils,  will  therefore 
vibrate  and  reproduce  the  sound* 

When  I  first  rigged  up  this  demonic 
device,  solid  state  equipment  was  virtually 
unheard  of,  so  I  simply  connected  one  foil 
to  the  plate  of  my  final  amplifier  tube,  and 
the  other  to  the  chassis.  Electrostatic  speak- 
ers work  best  when  the  audio  is  riding  on 
top  of  a  high  dc  voltage.  This  polarizing 
voltage,  as  it*s  called,  was  neatly  provided  by 
the  plate  supply  voltage  which  was  there 
anyway. 

Nowadays  most  audio  equipment  is  solid- 
state.  Since  solid-state  operates  under  very 
different  conditions,  you  will  now  have  to 
artificially  duplicate  vacuum  tube  condi- 
tions. An  electrostatic  speaker,  you  see,  is  a 
very  high  impedance  device,  and  so  it  must 
be  fed  with  a  high  voltage  signal  from  a  high 
impedance  source.  You  can  meet  this 
requirement  by  connecting  a  small  output 
transfonner  in  reverse.  That  is,  the  voice  coil 
winding  connects  to  the  output  terminals  of 
your  amplifier.  The  plate  winding  connects 
to  the  foils,  A  polarizing  voltage  of  a 
hundred  volts  or  so  can  be  supplied  either 
from  a  rectifier  or  from  a  battery,  the 
capacitor,  C,  providing  a  path  for  the  audio 
voltage- 


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73  MAGAZINE 

Peterborough  IMH  03458 

Tl<^COUMON     OLfTPUT    TRANSFORMER. 
Tl     varC£     COfL     WINDING      SHOULD 
WATCH       AMPLIFIER     OUTPUT, 
OTHER      WINDIflOS       SHOULD      Bt 
AS      HIGH      IMPEDANCE     AS     POSSIBLE 


AMPLfFIER 
SPCAKCR 
TERMINALS 
4-^9   OHM 
OUTPUT 


10  II F 
400  V 


/77 


ii 


100    TO    900    V 

POLARlIlltd     VOLTAOC 


Fig,  2,  Method  of  connecting  electrostatic  speak^ 
er  to  output  of  solid  state  ampHfier. 


Even  if  you  do  not  have  a  sweet  old 
grandmother  to  bug  with  this  tomfoolery^  it 
can  still  be  an  excellent  party  gag,  and  I 
know  of  no  better  way  to  have  your  best 
friends  tag  you  as  an  absolute  unmitigated 
nut. 

.  .  .  W2FEZ 


I 
* 


I 


DECEMBER    1970 


95 


an  FM  Late  Starter 


,  ,  could  be  a  front  runner! 


I  have  nothing  but  praise  for  Regency^'s 
new  HR-2  minialure  multichannel  all- 
Iransislor  2  meter  FM  transceiver.  This  is 
far  and  away  the  best  buy  in  American- 
made  amateur  FM  units.  It's  priced  right,  it 


Ken  Sessions  K6MVH 

output  power,  and  it  is  one  of  the  smallest 
units  obtainable.  And  it  has  some  very 
desirable  features  that  none  of  the  other 
manufacturers  have  thought  of  yet. 

Of  all  the  good  points,  the  price  itself  is 


performs    right,   it   1 

las  a  very 

respecta 

ble       ttie  mos 

it  impressive.  J 

VL  bJiy 

there  should 

Manufacturer 

Model 

Price 
(S) 

Channel 

Combinations 

Available 

Total 

Xtals          Mfr 
T     R        Loc 

Xmtr 
Pwr 

Out 

W) 

Rcvr 
Sens 
(^V  -  20  dB) 

Regency  Electronics 

HR-2 

229 

12 

6        6 

1 

U.S. 

10-12 

0.5 

Galaxy  (Hy-Gain) 
(w/power  booster} 

FM-210 

230 

9 

3        3 

U.S. 

2.5 

1.0 

Telecomm 

FM144-10F 

250 

6 

6        6 

U.S. 

10 

0.5 

VariTronics  (Inoue) 

FDFM-2S 

270 

6 

6       6 

Jap. 

10 

0.8 

Standard 

SR-C806M 

349 

12 

12      12 

Jap, 

10 

0.5 

Varitronics  (Inoue) 

IC-2F 

349 

36 

6        6 

Jap. 

12-15 

0.4 

CI  egg  Associates 

22er 

400+ 

Tunable 

10        0 

U.S. 

30 

0.4 

RX.  Drake  Co. 

329 

12 

12      12 

Jap. 

10 

0.5 

96 


73  MAGAZINE 


be  no  reason  at  all  for  any  VHF  enthusiast 
to  put  off  going  to  FM  any  longer.  You're 
just  not  going  to  get  on  2  meters  FM  in 
style  for  anything  less. 

Now  let's  take  a  look  at  what  you  get 
for  that  $229: 

How  about  power?  The  Regency  HR-2 
runs  between  10  and  12  watts  owfpwf /The 
Motorola  transistor  that  the  Regency  unit 
uses  in  the  final  rf  amplifier  is  guaranteed 
to  crank  out  at  least  10  watts,  and  the 
people  at  Regency  are  making  sure  that 
each  unit  produced  meets  or  exceeds  that 
specification. 

Deviation  level.  When  the  Regency 
leaves  the  factory,  the  deviation  is  set  at  10 
kHz.  Since  this  is  a  little  much  for  the  New 
England  repeaters,  I  had  to  crank  our  test 
model  down  to  about  7  kHz.  The  deviation 
can  be  adjusted  anywhere  from  less  than  5 
to  slightly  more  than  15  kHz  with  an  easily 
accessible  pot  inside  the  rig.  The  unit 
comes    with    microphone,    too,    by    the 


way  -  and  from  reports  of  the  local 
repeater  groups^  the  audio  is  exceptionally 
clean. 

What  about  the  receiver?  The  receiver  is 
a  dual-conversion  superheterodyne  type 
with  six-channel  capability.  It  is  relatively 
broad-banded,  requiring  no  peaking  on 
individual  channels  in  the  2  meter  range.  A 
ceramic  filter  in  the  second  i-f  stage  gives 
adequate  selectivity  for  most  metropolitan 
areas^  even  where  adjacent  charmels  are 
active. 

If  you  buy  this  rig  and  later  decide  to 
add  crystals,  you've  got  to  be  a  bit  choosy 
as  to  where  you  buy  your  rocks.  The  HR-2 
has  no  means  of  rubbering  "receive" 
crystals  onto  frequency;  if  the  crystals  are 
off,  your  receiver  wUl  be  off.  The  people  at 
Regency  say  nobody  will  ever  have  trouble 
if  they  order  from  Sentry  Manufacturing 
Company  (Oklaho  ma) ,  I  n  ternational 
Crystals  (Oklahoma),  or  Shepherd  Indus- 
tries (Kansas).  To  my   mind,  the  lack  of 


Accessories  Included 
in  Purchase  Price 


Extras 
You 

Must 
Buy 


Comments,  Special 
Features 


Problems,  disadvantages 


Microphone,  power  cord, 
mobile  mounting  bracket, 
crystals  for  146.94. 


Power  plug. 


Mike,  mobile  mounting  bracket, 
power  cord,  crystals  for  146.34 
and  146.94, 


Mike,  mobile  mounting  bracket, 
power  cord,  crystals  for  146.34 
and  146.94. 


Mike,  moinle  mounting  bracket, 
power  cord,  crystals  for  146.94. 


Mike,  mobile  mounting  bracket, 
power  cord,  crystals  for  146.34 
and  146.94,  antenna  connector, 
spare  fuse,  connector  for 
optional  external  speaker. 
Discriminator    test    socket    and 
plug. 


None 


ALL 


None 


None 


None 


None 


See  text 


Power     booster     supplies 
24V  dc  to  final  transistor 
to  bring  the  rf  output  up 
to5W.  (costs  S50  extra). 


Panel  meter  for  rf  out  & 
signal  strength. 


Illuminated  panel  meter 
for  rf  out  &  signal  strength 


in. 


High/low  power  switch; 
illuminated  panel  meter. 
Add-on  amplifier  avail. 


Ac/dc  power  supply,  micro- 
phone, power  cords  for  ac 
and  mobile  operation. 


Mobile  antenna,  coax,  mobile 
mount,  mike,  ac/dc  pwr  splys. 


None 


None 


Panel  meter  illuminated 
white  on  rev,  red  during 
transmit.  Meter  indicates 
S'Unitsand  rf  out.  Freq 
selector  switch  is  concen- 
tric so  xmit  and  rev  chan- 
nels are  independently 
controlled. 


Built-in  ac/mobite  power 
supply. 


Built-in  ac/mobile  pwr 
supply.  Extremely 
selective  &  stable  rcvr* 


No  meter;  no  receiver 
rubbering  capacitors. 


No  accessories,  no  meter, 
unstable  rubbering 
capacitors. 


Test  unit  did  not  meet 
specs. 


Antenna  connector  makes 
sloppy  fit  to  VHF  connector. 


Squelch  and  volume  controls 
too  tiny  for  easy  mobile 
operation. 


Tunable  receiver.  Too 
large  for  mobile  use- 
Tube- type  transmitter 

final. 


Transmitter  has 
vacuum-tube  final, 


1 


DECEMBER    1970 


97 


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serviceman  or  amateur  should  b«  without  this 
tremendous  book. 

f25  One-Transistor  Projects,  hardbound   .  »  $6.95 

Practicai  circuits  for  the  eitperimenter  end 
hobbyist.  Have  fun  building  the**  l-transistor 
€ircu its, „ test  ir>struments,  audio  amps,  osciHe- 
tors,  receivers,  transmiiiers^  alarm  devices,  etc. 
Never  will  you  have  so  n^uch  fun  for  to  little. 


3458 

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wonderfut  book.  Also  info  on  noise  bridges, 
other  test  equipment  you  can  n'^ake  and  use  to 
advantage. 


73  Oipole  and  Long  Wire  Antennas 

W3FQJ.     Better    buy    both    books, 
dimensions,  details. 


$4  JO 

Includes    all 


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Installing  6f  Servicing  Home  Audio  Systems  $?S5 
Hardbound,  256  pages.  Worth  its  weight  in  gold. 
Positively  the  finest  book  ever  written  on  the 
subject.  Make  a  fortune  in  part  time  audio  work. 
Hi-fi  is  everywhere  and  none  of  them  are  working 
right. 

64  Hobby  Projects  for  Home  and  Car 
Hardbound.  ...«...<«..-■*  ^ ., p , .... .  $6.95 

Any  one  project  li  worth  more  than  the  price  of 
the  whole  book,  Light  sensitive  garage  light, 
wireless  TV  commercial  kitfer,  fire  alarms,  smoke 
alarm,  etc.  If  you  are  having  less  fun  in  radio  you 
aren't  building  enough  smalt  projects.  This  book 
is  guaranteed  fun. 

CB  Radio  Operator's  Guide,  hardbound    . .  $6.95 

Most  complete  book  ever  published.  Lists  all 
equipment  and  antennas  available,  all  acces- 
sories...how  to  use  them,  how  to  set  up,  test,  get 
best  action.  Contains  complete  CB  rules  end  regi. 

Servicing  Modern  Hi-Fi  Sy^ems 

by  Crowhurst.  ,  .  , ,  .  $7.95 

Hardbound^  Paperback  is  only  $4.95,  but  won't 
look  as  nice  on  your  shelf  or  last  as  long,  Thom 
solid-state  hi-fi's  bugging  you?  Like  duck  soup 
with  this  gem  of  a  book.  Why  take  hours  to  find 
miseries  when  you  can  take  this  book  mn^ 
pin-point  difficulties  imrnedtately.  This  book  will 
either  save  you  a  fortune  or  make  you  one. 

Basic  Electronics  Problems  Soved;  Smith  .  .  $7.95 
Hardbound.  Paperback  is  only  $4.95  if  you  don't 
care  how  your  library  looks.  Solid  state  Bn0  tube 
circuits.  This  is  a  "cheat  book"  which  will  whiz 
you  through  any  electronics  course  by  showing 
you  short  cuts  in  solving  electronics  problems 
and  math. 

Modern  Electronic  Circuit  Design  by  Long  $9.95 
Hardbound,  286  pages^  McGraw-Hill.  Written  for 
professional  circuit  designers,  graduate  engineers. 
Published  at  $18.95.  Looks  very  impressive  on 
the  reference  shelf.  Worth  many  times  the  price 
as  prestige  book.  Also  handy  if  you  happen  to  be 
an  engineer.  Limited  quantity  on  hand.  Hurry. 

Handbook    of    Practical     Electronic    Tests    and 

Measurements,  Lenk.  Hardbound  $9.95.  Pub- 
lished at  $18.  A  guide  to  the  basic  theory  and 
application  of  every  practical  electronic  test  and 
measurement  procedure  for  technictani  Lnd 
amateurs.  Limited  supply  so  act  fast. 

Pulse  and  Switching  Circuits^  hardbound  .  .  $7.95 

Almost  ev  ery  phase  of  electronics  uses  switching 
circuits, .TV,  radar,  telemetry,  computers,  etc. 
About  time  you  read  up  on  every  one  of  these 
circuits  being  used,  isn't  it?  256  pages,  over  200 
illustrations.  Available  paperbound  (fails  apart) 
for  $4.95. 

FM  Receivers  by  Cook 

Hardbound,  528  pages.  ...  * .  $14.50 

Published  at  $2&.  Most  comprehensive  boolc  ever 
published,  absolutely  up  to  date..,  ail  circuits. 
Invaluable  for  professionals  and  advanced  ema-^ 
teu  rs. 


Amateur   Radio   Advanced   Class   Licen»  Study 
Guide. $6.95 

Hardbound  book  for  your  library  shelf.  193 
pages!  Absolutely  everything  you  need  to  know 
to  pass  this  license  exam,  written  by  one  of  the 
top  radio  editors  in  the  business.  Written  for  the 
simple-minded  so  they  can  pass  the  exam  by 
knowing  the  answers  ipstead  of  memorizing 
them.  This  book  is  available  in  softbound  for 
$3.95.  Vou  ere  going  to  have  to  get  an  advanced 
license  so  you  might  as  well  get  this  book  right 
now. 

Electro  mechanical  Oeviees  for  Energy  Conversion 
and  Control  Systems,  by  Del  Toro 
Published  at  $25.   Limited  supply  at  $10.  Hard- 
bound, 617  pages. 


tweaking  ability  on  the  receiver  is  a  distinct 
disadvantage  —  but  it  is  overshadowed  by  a 
considerable  margin  when  I  consider  the 
xmit's  sales  price. 

Special  features?  The  most  useful  single 
feature  of  the  HR-2  is  its  multiplicity  of 
transmit— receive  combinations.  There  are 
six  crystal  positions  each  for  the  trans- 
mitter and  the  receiver,  but  a  twelve 
position  switch  is  used  for  selection.  The 
first  six  positions  on  the  switch  (numbered 
1  through  6  on  the  faceplate)  select  the  six 
crystal  positions,  and  the  next  six  positions 
on  the  switch  (labeled  A  through  F)  can  be 
used  to  select  specific  combinations  of  the 
various  crystal  sets.  Positions  A  through  F 
are  chosen  by  jumpering  on  the  switch 
itself,  so  that  there  are  a  total  of  12 
available  channel  sets  from  only  six  sets  of 
crystals. 

Now  does  the  Regency  HR-2  stack  up? 
Probably  the  best  way  to  determine  the 
relative  merits  of  the  HR-2  is  to  compare 
the  unit  with  other  2  meter  FM  trans- 
ceivers. The  chart  on  the  preceding  pages 
will  give  you  an  opportunity  to  make  your 
own  comparison  and  evaluate  the  features 

you  consider  to  be  the  most  important, 

. . . K6MVH  ■ 


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WORLD  ATLAS  —  Only  atlas  compiled  for  radio  ama- 
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11  maps,  in  4  colors  with  zone  boundaries  and  coun- 
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—  a  complete  set  of  maps  of  the  world.  20  pages, 
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World's  Finest  Log  Book? 

Designed  and  executed  by  W2NSD/1,  thTs  Is 
the  most  relevant  amateur  radio  log  ever  de* 
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contact,  a  small  column  to  indicate  whether 
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a  good  wide  space  for  the  station  call  con- 
tacted, little  columns  for  the  reports,  a  good 
space  for  his  location,  a  QSL  column,  and  lots 
of  room  for  notes.  The  log  Is  the  long  way  on 
standard  BVk*'  x  11"  paper  and  padded  into 
pads  of  12B  sheets^  with  room  for  20  contacts 
per  page.  The  whole  book  of  log  sheets  will 
carry  you  through  2500  contacts.  There  is  a 
pJace  to  indicate  on  each  sheet  the  band  being 
used  and  the  power  m  case  these  change  now 
and  then.  The  log  pages  can  be  numbered  for 
file  card  reference.  Why  use  a  log  book  designed 
in  the  1920's?  This  one  was  designed  for  use  In 
the  70's  and  is  exactly  right  for  the  DX'er,  the 
rag  chewer,  or  even  the  round-table  denizen.  It 
Is  fine  for  CW  or  phone,  AM  or  srdeband.  It  will 
work  for  RTTY,  ATV  or  even  slow  scan 
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125  Super  W2NSD  log  sheets.  .  .  .only  $2  ppd. 

73  Magazine,  Peterborough  NH  03458 


DECEMBER    1970 


99 


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VHF  ANTENNAS 
This  handbook  fs  a  complete  collection  of  up-to- 
date  mformation  about  VHF  and  UHF  antennas, 
with  design  hints,  construction  and  theory.  If 
you've  been  wondering  what  array  you  need,  this 
book  will  give  you  enough  background  to  make  the 
right  decision,  $3 


ADVANCED  CLASS  STUDY  GUIDE 

128  pages  of  up-to-the-minute  simplified  theory, 
written  with  the  beginning  radio  amateur  in  mind. 
This  unique  book  covers  all  aspects  of  the  theory 
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exam.  .  .nothing  else  like  it  in  print,  $3 


DIODE  CIRCUITS  HANDBOOK 
An  invaluable  reference  book.  Cavers  rectifiers, 
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COAX  HANDBOOK 
Invaluable  book  for  the  ham  or  the  fab  and  for 
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73  USEFUL  TRANSISTOR  CIRCUITS 
If  you've  been  looking  for  a  transistor  circuit  to  do 
a  speciai  job,  chances  are  there  is  a  circuit  in  this 
book  that  will  give  you  a  head  start.  It  covers 
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INDEX  TO  SURPLUS 
Do  you  have  a  piece  of  surplus  equipment  that  you 
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DX  HANDBOOK 

Includes  giant  world  country-zone  wafi  map. 
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record  lists,  time  charts,  propagation,  etc.  Special 
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SIMPLIFIED  MATH 
Does  math  scare  you?  —  It  shouldn't.  This  easy-to 
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FM   ANTHOLOGY 


Vol.  (.  This  book  is  largely  a  collection  from  FM 
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The  material  is  taken  from  the  editions  of 
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Books  shipped  prepaid  in  US  and  Canada, 

73  Magazine 

Peterborough,  N.  H.  03458 


* 


Of  all  the  various  transistor  tester  pro- 
jects that  have  appeared  in  numerous 
amateur  radio  and  electronic  magazines 
this  past  decade,  I  beheve  I  have  come  up 
with  a  circuit  that  will  outdate  previous 
articles.  Many  of  these  projects  have  been 
designed  so  you  may  utUize  a  tester  with 
your  scope,  VTVM,  or  some  other  gear- 

This  particular  circuit,  which  I  named 
the  'Transi-Test/'  is  designed  with  simpli- 
city and  is  very  accurate  in  measuring  beta, 
leakage,  and  shorts.  It  will  test  any  NPN  or 
PNP  transistor  (signal  or  power).  1  also  find 
it  great  in  checking  silicon  or  germanium 
diodes  by  using  the  emitter  and  collector 
leads  to  test  for  shorts  and  leakage.  The 
Transi-Test  is  100%  portable,  using  a  9V 
battery  for  its  power  supply- 
Most  transistor  testers  employ  a  4pdt 
switch  for  polarity,  but  this  one  is  designed 
around  a  dpdt  switch,  which  is  easy  to  find 
at  any  parts  store.  To  say  the  least,  all  the 
parts  can  probably  be  found  in  your  own 
junkboxf  I  used  a  Premier  #SPC-23  meter 
case  to  give  the  Transi-Test  a  professional 
appearance.  The  three  test  leads  should 
extend  6  to  8  in.  from  the  front  of  the 
case.  For  easy  connection  to  small  transis- 
tors, a  micro  alligator  clip  should  be  used 
such  as  the  Mueller  #34-C.  Be  sure  to  use 
an  alligator  insulator  on  the  collector  lead 
to  prevent  the  emitter  and  collector  leads 
from   shorting   togetlier   due    to  stiff  test 


Lew  Christy  WB6QQP 
342  E.  Second  Street 
Rialto  CA  92376 


leads.   This  will  save  unnecessary  battery 
failure. 

If  you  do  transistor  servicing  quite 
frequently,  it  is  advisable  to  use  a  toggle 
switch  (SI)  which  will  last  indefinitely. 
The  only  holes  that  have  to  be  drilled  in 
the  case  are  for  the  three  test  leads,  using 
rubber  grommets.  The  SPC'23  meter  case  is 
already  prepunched  for  the  meter  and  two 
switches,  which  is  why  I  happened  to 
choose  tliis  particular  one.  Bud  Radio  also 
manufactures  a  case  identical  to  this  one. 


p 


60K'! 


47 


31 


6 

E 


Si 


6    6 

B      e 


After  completion  of  this  small  project, 
you  can  rummage  through  your  junkbox 
and  start  identifying  those  "lost  cause" 
transistors  that  have  been  lying  dormant  all 
this  time.  Vm  sure  you  will  find  the 
Transi-Test  to  be  a  very  valuable  test 
instrument  on  your  workbench- 
Lew  Christy  WB6QQP  ■ 


• 


DECEMBER    1970 


101 


^« 


Never  Say  Die  (cant,  from  p.  10} 
been  a  strong  factor  in  freezing  the  League  into 
immobility.  We  cannot  afford  this  paralysis  in  the 
1970s,  if  directors  were  to  attend  four  regional 
ARRL  conventions  each  year  (east,  midwest, 
southwest,  west)  and  consult  the  membership  at 
open  forums  at  these  conventions,  they  could  act 
immediately  upon  the  wishes  of  the  members. 
Their  way  would  be  paid  to  the  four  conventions 
by  HQ. 

Public  Relations 

A  competent  public  relations  firm  (preferably 
run  by  an  amateur)  should  be  engaged  to 
promote  amateur  radio  with  articles  in  national 
magazines  such  as  Life,  Look,  New^sweek,  Play- 
boy,  etc.  They  could  coordinate  amateur  radio 
talent  such  as  writers,  cartoonists,  and  performers 
for  maximum  effect.  They  could  help  to  organize 
ham  films  for  television,  for  schools,  and  even 
shorts  for  movies.  They  could  prepare  strip  slide 
shows  for  schools  and  libraries.  They  could 
prepare  news  releases  for  the  papers  and  news 
services,  thus  making  sure  that  amateur  accom- 
plishments reached  the  television,  papers,  and 
radio. 

Club  Material 

In  order  to  increase  interest  in  radio  clubs 
throughout  the  country  the  ARRL  should  have  a 
wide  variety  of  films  available,  covering  all 
aspects  of  amateur  radio  operation. ,xon  tests, 
DXpeditions,  moonbounce,  television,  RTTY, 
traffic  nets,  mobile  operation,  repeater  operation, 
etc.  There  are  many  amateurs  that  would  be 
happy  to  work  to  produce  films  and  slide  shows 
on  amateur  radio  subjects  if  only  there  were  a 
central  organizing  effort.  ARRL  could  provide 
this  coordination.  Films  and  slides  can  do  a  lot 
toward  building  club  membership  as  any  member 
of  sports  car  clubs  and  skin  diving  clubs,  will  tell 
you.  Amateur  radio  is  almost  alone  in  its  lack  of 
interesting  program  material  for  clubs.  This 
should  be  a  function  of  the  League.  Who  else  is 
there? 

Outgoing  QSL  Service 

Virtually  every  other  national  amateur  radio 
society  in  the  world  provides  an  outgoing  QSL 
service  for  its  members  sending  cards  to  other 
countries.  There  are,  as  far  as  I  know,  no  in- 
surmountable problems  stopping  the  League  from 
providing  a  simitar  service.  This  should  be  care- 
fully investigated  from  the  viewpoint  of  fmding 
out  how  to  do  it  rather  than  trying  to  find 
out  why  it  can't  be  done. 

Legal  Fund 

The  legal  problems  involved  in  setting  up  an 
emergency  fund  for  helping  amateurs  fight  law- 
suits which,  if  lost,  could  seriously  affect  the 
whole  amateur  radio  hobby  should  be  investi- 
gated and  overcome.  Is  there  any  real  reason  why 
the  League  should  not  help  beleaguered  amateurs 
in  such  legal  fights? 


Amateur  Radio's  Future 

Satellite  repeaters  for  FM  and  ATV  are  within 
the  realm  of  technical  feasibility  today.  The 
League  should  take  the  lead  in  planning  for  the 
future  of  our  hobby.  Even  the  cost  of  a  set  of 
satellite  repeaters  covering  the  whole  world  could 
be  organized  by  the  ARRL.  Perhaps  the  techni- 
ques of  multiplexing  can  be  developed  and 
applied  to  solve  ORM  problems  on  20m  and 
other  crowded  bands.  Dialog  in  QST  on  new 
ideas  should  be  encouraged. 

Radio  Clubs 

It  is  possible  that  the  role  of  amateur  radio 
clubs  could  be  expanded  in  the  administering  of 
exams  for  the  FCC, Certainly  the  clubs  could  be  a 
powerful  factor  toward  developing  new  amateurs 
with  guidance  and  encouragement  from  HQ.  A 
monthly  newsletter  to  provide  dialog  between 
radio  club  presidents  and  the  directors  might  help 
encourage  amateurs  to  take  more  interest  in  their 
future, 

lARU  Development 

The  International  Amateur  Radio  Union,  made 
up  of  the  national  amateur  radio  societies  of  the 
world  and  organized  by  ARRL  could  function 
better  and  provide  better  leadership  if  ARRL 
were  to  publish  a  monthly  newsletter  for  aU 
member  societies.  At  present  all  that  is  provided, 
1  understand,  is  a  yearly  calendar.  Region  1 
(Europe  and  Africa)  periodically  publishes  news- 
letter. The  amateur  radio  societies  in  the  rest  of 
the  world  might  have  more  confidence  in  lARU 
if  it  provided  some  leadership  and  communica- 
tions. 

The  lARU  could  spearhead  a  drive  to  collect 
older  amateur  radio  equipment  and  ship  it  to 
underdeveloped  nations.  The  shortage  of  equip- 
ment is  one  of  the  most  important  deterrents  to 
new  amateurs  in  these  countries.  India  could  have 
thousands  of  amateurs  instead  of  a  few  hundred 
if  only  gear  were  available- 
Unity  of  the  lARU  societies  would  provide 
unity  toward  the  problems  of  the  ITU  and 
frequency  allocations.  Communications  is  the 
first  step  towards  unity. 

New  Books 

The  ARRL  book  department  should  be 
turned  upside  down  and  cleaned  out.  One  look  at 
the  Editors  and  Engineers  handbook  is  enough  to 
prove  that  a  major  change  is  needed  in  the 
production  of  books  at  HQ.  The  yearly  ARRL 
Handbook  changes  like  a  glacier.  Not  only  that, 
but  one  of  Iife*s  more  frustrating  experiences  is 
to  try  and  learn  radio  theory  from  that  book. 
This  is  not  necessary  as  we  showed  with  our 
license  study  courses. 

Spend  25^  and  buy  a  copy  of  the  ARRL  book 
on  "Operating  an  Amateur  Radio  Station."  This 
publication  is  all  too  typical  of  League  literature 
and  is  beyond  description.  As  a  director  I  would 
make  every  effort  I  could  to  see  that  those  re- 


102 


73  MAGAZINE 


sponsible  for  this  type  of  claptiap  were  trans- 
ferred to  some  other  job. 

The  League  has  a  responsibility  to  produce 
interesting  and  up-to-date  books  on  every  aspect 
of  amateur  radio-  They  should  have  thorough 
study  books  on  each  amateur  exam,  not  memo- 
rization manuals  as  they  do  right  now.  They 
should  have  a  definitive  and  continually  up- 
dated book  on  RTTY,  DX,  ATV,  FM,  moon- 
bounce,  traffic,  VHF,  learning  the  code,  high- 
speed code,  frequency  measuring,  160mj  antennas, 
microwaves,  etc. 

QST  can  carry  information  on  building  gear, 
on  new  developments,  and  such,  but  books  are 
needed  to  provide  detailed  information  on  speci- 
fic interests.  Obviously  these  would  all  pay  for 
themselves. 

New  General  Manager 

Few  amateurs  with  whom  I  have  talked  have 
had  anything  encouraging  to  say  about  their  visits 
with  the  present  ARRL  manager.  Though  I  donU 
talk  with  him  often,  I  must  admit  that  on  each 
occasion  I  have  found  him  to  be  as  close-minded 
as  the  visitors  have  reported.  If  he  were  capable 
of  doing  his  job  we  would  not  have  the  growing 
problems  here  and  all  over  the  world  which  he 
has  brought  upon  us. 

Were  I  to  be  elected  a  director  I  would  try  to 
get  the  other  directors   to  start  looking  for  a 

suitable  manager  for  ARRL, 

It  would  not  be  simple  to  find  the  right  man 
for  this  difficult  job.  There  are  many  qualifica- 
tions that  he  should  have  to  be  worthy  of 
consideration.  But  you  may  be  sure  that  such  a 
man  exists  and  that  it  is  important  that  he  be 
found  before  it  is  too  late. 

What  sort  of  man  do  we  need  for  this  post? 
As  I  see  him,  he  should  be  a  man  who  has 
devoted  a  good  deal  of  his  life  to  amateur  radio. 
He  certainly  should  have  a  record  of  being 
interested  and  active  in  several  branches  of  the 
hobby,.. DX,  TV,  RTTY,  VHF,  FM,  traffic,  etc.  I 
would  expect  that  he  has  done  a  good  deal  of 
building  and  designing.  I  would  think  it  strange  if 
he  had  not  had  several  articles  pubhshed. 

The  ARRL  is  a  $1,500,000  business,  so  we 
should  expect  our  man  to  have  experience  in 
running  a  medium- sized  business.  One  of  the 
problems  at  HQ  is  mismanagement  of  finance. 
There  is  no  shortcut  to  business  knowhow. 

Our  manager  is  also  the  editor  of  QST,  so 
some  background  in  publications  would  be  valu- 
able. He  will  need  this  to  help  cut  the  present 
runaway  costs  of  publication  of  the  magazine.  Of 
course  he  could  learn  about  all  this  after  being 
hired  if  you  like  the  idea  of  on-the-job  training  at 
your  expense. 

Our  man  should  be  able  to  speak  well  in  front 
of  large  groups-  The  general  manager  is  also  a 
front  man  for  ARRL  and  must  attend  most 
ARRL  functions  as  host.  He  would  also  be  ex- 
pected to  speak  for  the  United  States  at  inter- 
national gatherings  and  at  the  ITU, 


One  would  hope  that  the  manager  of  the 
ARRL  was  highly  intelligent-  Can  we  afford  to 
have  a  mediocre  brain  at  the  head  of  265,000  U.S. 
amateurs?  And  remember  that  he  is  the  titular 
head  of  amateur  radio  worldwide.  This  spot  calls 
for  all  the  brains  we  can  muster, 

I  suspect  that  we  should  also  be  sure  that  the 
man  we  choose  is  one  with  a  long  history  of 
getting  things  done,  A  man's  history  speaks  for 
him.  If  he  is  too  wealthy  he  has  devoted  himself 
to  wealth  alone  and  not  to  other  interests.  Has  he 
a  wide  number  of  accompHshments?  Is  he  well 
read?  WiU  he  be  interested  in  working  for  a 
modest  salary  with  his  major  payment  in  achieve- 
ment? The  answer  is  simple,  of  course.  If  you 
ask  any  director  of  any  large  corporation  how  he 
goes  about  finding  a  new  general  manager,  he  will 
tell  you  that  there  are  a  number  of  organizations 
that  specialize  in  just  that.  You  consult  one  and 
let  them  find  your  man. 

Most  of  the  directors  that  I  have  talked  with 
recognize  that  it  is  important  for  them  to  locate  a 
new  general  manager,  but  they  are  afraid  to  take 
the  bull  by  the  horns. 

Other  Ideas 

This  is  by  no  means  the  end  of  my  ideas  for 
improving  the  ARRL,  but  I  have  probably  lost 
90%  of  my  readers  already  and  should  shut  up. 
Now  that  I've  told  you  some  of  the  things  I 
would  try  to  do  if  I  were  elected  director  of  the 
ARRL,  perhaps  you  can  encourage  your  own 
director  to  go  ahead  with  some  of  them*  Or  you 
can  work  to  get  a  director  elected  that  will  do 
what  you  want, 

73  at  Boston 

The  ARRL'  National  Convention  hit  Boston  in 
the  fall  this  year,  providing  a  splendid  display  of 
New  Hampshire  foliage  for  those  interested  in 
beauty. 

When  f  got  word  from  the  convention  com- 
mittee that  no  one  from  73  would  be  permitted 
to  speak  at  any  convention  function,  I  made 
arrangements  to  hire  an  auditorium  room  in  the 
hotel  to  provide  forum  space  for  those  interested 
in  FM,  repeaters,  ham  politics  and  my  slides  of 
Jordan  taken  just  before  the  civil  war  there- 
in 1969  we  took  along  an  international 
Crystal  microwave  oven  and  cooked  some  New 
Hampshire  hotdogs  as  a  feature  of  our  exhibit. 
This  was  popular,  but  I  didn't  want  to  repeat  so 
we  decided  to  have  some  freshly  squeezed  New 
Hampshire  apple  cider  along  with  fresh  home- 
made New  Hampshire  donuts  this  time. 

On  the  Friday  afternoon  before  the  conven- 
tion we  went  up  to  Hancock  (N-HJ  and  helped 

Joe  Quinn  run  off  almost  30  gallons  of  the  best 
apple  cider  you  ever  tasted.  Early  Saturday 
morning  we  stopped  by  Crane's  Bakery  in  Jaffrey 
(N.H.)  and  picked  up  73  dozen  old-time  New 
England  donuts.  None  of  those  machine-made 
crullers  for  us!  There  wasn't  a  really  round  one  in 
the  bunch. 


I 
I 


DECEMBER    1970 


103 


mm 


We  served  the  cider  and  donuts  all  day 
Saturday  in  between  slide  shows,  forums,  and 
talks  in  our  auditorium  room.  By  the  way,  one 
leally  outstanding  show  was  put  on  by  George 
Fataki  Y02B0*  showing  slides  of  visiting  DX 
hams  and  his  recent  visit  to  DX'ers  in  Europe, 

To  those  who  have  written  to  thank  us  for  the 
feed  and  the  programs,  we  hereby  acknowledge 
your  notes  and  want  you  to  know  we  appreciate 
your  thoughtfulness. 

A  Look  Around  73 

In  looking  at  last  year's  staff  picture  we  see 
several  absentees,  alas.  Two  of  our  gals  left  to  get 
mairiedj  and  a  third  left  to  work  with  her 
husband  who  started  his  own  business. 

We've  had  some  interesting  replacements  for 
the  dear  departed,  starting  with  Nancy,  who  was 
with  us  back  in  early  1970,  but  had  gone  off  to 
seek  her  fortune  in  Colorado,  and  returned,  she's 
not  sure  why.  Nancy  puts  together  most  of  the 
ads  in  each  issue  as  well  as  laying  out  many  of  the 
articles-  Jan,  the  other  gal  in  the  art  department, 
does  most  of  the  rest  of  the  articles.  In  her  spare 
time  Jan  is  an  outstanding  artist,  joining  Lin  out 
in  the  73  art  studio  afternoons  and  weekends. 

Ken  Sessions  (K6MVH)  has  added  a  new 
dimension  to  the  editing  of  73,  as  well  as  an 
almost  undetectable  tendency  to  favor  FM  arti- 
cles. Ken  is  responsible  for  the  new  arty  look  of 
the  articles  in  73. 

Taylor  Sage  joined  us  recently  and  does  just 
about  everything  that  we  can*t  get  anyone  else  to 
do,  from  supervising  the  maintenance  of  the  HQ 
building  to  keeping  our  recalcitrant  machinery 
running.  His  wife  Gigi  handles  the  bookkeeping. 

In  our  print  shop  we  have  Jeff  Parsons  and 
Biff  Mahoney,  who  run  our  three  offset  presses, 
turning  out  local  job  work  as  well  as  office  forms, 
advertising  letters,  and  stuff  like  that.  73  is 
printed  in  Wisconsin,  not  here,  but  we  do  have 
complete  facilities  for  smaller  printing  jobs  and 
turn  out  our  books  right  here, 

Nixon  Letter  Reprints 

Several  clubs  have  called  and  written  asking 
for  bulk  copies  of  the  October  73  Action  Coupon 
addressed  to  President  Nixon,  This  coupon  re- 
qiiLsts  an  investigation  of  the  recent  increase  in 
license  fees  for  radio  amateurs.  If  you  would  like 
reprints  of  this  page  just  send  a  sell-addresscd 
stamped  envelope  to  73,  Peterborough, 
N-H.03458  and  indicate  how  many  reprints  are 
desired. 

Ham  Bumper  Stickers? 

Several  readers  have  suggested  thai  bumper 
stickers  be  made  available  for  amateurs.  Since  wc 
have  dandy  facilities  for  printing  up  bumper 
stickers  here  at  73  we  are  all  for  the  idea.  But 
what  do  you  want  on  the  stickers?  We  are  open 
for  any  clever  suggestions.  The  only  sticker  we 
have  seen  so  far  is  BAN  THE  HAM,  and  that 
doesn't  seem  appropriate. 

73. ,  -Wayne  ■ 


Leaky  Lines  fconr,  from  p,  14) 

season,  but  who  lapse  into  a  state  of  sudden 
paraplegia  when  any  mention  of  the  FCC 
examination  is  made.  They  remind  me  of  some 
unnamed  soldiers  of  my  acquaintance,  who, 
never  having  served  overseas  in  World  War  II, 
wore  some  unauthorized  ETO,  Asiatic  Theatre, 
Persian  Gulf  Command  or  Purple  Heart  ribbons 
on  their  tunics  when  they  went  out  on  dates 
with  young  and  impressionable  (or  old  and 
impressionable)  females. 

I  know  that  \  am  running  the  risk  of  falling 
into  disfavor  with  the  35,000  odd  Conditionals 
when  1  say  this,  but  I  feel  strongly  that  some 
changes  in  this  situation  are  long  overdue. 
Perhaps  I  am  being  unduly  harsh  toward  the 
Conditionals,  but  ever  since  the  implementation 
of  Incentive  Licensing,  I  think  most  of  us  tend 
toward  a  less  permissive  and  less  tolerant  atti- 
tude concerning  all  '*something-for*nothing" 
advocates. 

I  am  already  considered  persona  non  grata 
among  large  numbers  of  Techs  who  objected  to 
my  published  views  with  respect  to  the  granting 
of  a  portion  of  ten  meters  on  an  exam-free 
basis.  They  labeled  me  with  ever>'  pejorative  in 
the  book,  and  with  a  few  even  I  had  never 
heard  before.  And  I  suspect  that  this  new  call 
to  sanity  will  place  me  squarely  in  the  path  of 
the  ''slings  and  arrows  of  outraged  Condilion- 
als."  So  be  it.  Might  just  as  well  be  hanged  for 
a  sheep  instead  of  a  goat 

I  truly  believe^  and  I  am  confident  that 
many  share  my  view,  that  all  classes  must 
somehow  be  drawn  into  the  vortex,  the  main- 
stream if  you  wilU  of  the  present  context  of 
licensing.  Operating  i\  ham  station  is  a  privilege, 
not  to  be  taken  lightly.  Any  preferential  excep- 
tions to  the  standards  which  are  now  being 
demanded  (intermediate  In  difficulty  tliough 
they  may  be)  constitutes  a  very  real  disservice 
to  aU  those  who  have  been  compelled  to 
uppade  in  order  to  maintain  their  allocations. 
Unless  all  amateurs  are  governed  by  identical 
rules  and  regulations,  subject  only  to  legitunaiB 
exceptions  for  valid  reasons,  the  entire  Incentive 
Licensing  structure  becomes  an  empty  mockery. 

Simply  stated,  \  am  catling  for  the  abolish- 
ment of  the  Conditional  class  license.  Now, 
liold  on  a  minute  .  ,  A  didn't  say  I  was  calling 
for  the  delicensing  of  Conditionals,  but  merely 
for  the  retirement  of  the  category.  I  have 
thought  for  a  long  time  that  the  designation 
* 'Condi  tional**  implies  by  its  very  name  a  type 
of  second  claims  stutus,  carrying  a  certain  stigma 
with  it.  Since  the  privileges  of  the  class  are 
identical  witli  the  General  ticket,  the  onlv 
reasons  why  it  is  maintained  are:  (1)  die  holder 
is  physically  handicapped,  or  (2)  he  lives  in  an 
area  so  far  removed  from  an  exam  point  that  a 
journey  thereto  would  consittute  an  unreason- 
able hardship.  Iience  has  not  taken  the  custo- 
mary FCC  administered  exam-  He  has,  however, 
attested  to  his  proficiency  in  the  required  tech- 


104 


73  MAGAZINE 


nicaJ  elements,  by  taking  an  exam  by  mailj 
supervised  by  a  volunteer  examiner.  In  all  other 
respects  the  grade  of  license  is  not  distinguish- 
able from  the  General  Hcense,  Why  then  must 
he  be  given  this  appellation  "Conditional"? 

An  apt  analogy  is  that  of  native  born 
citizens  and  naturalized  citizens.  Both  are 
entitled  to  exactly  the  same  rights  and  privi- 
leges. Both  are  expected  to  shoulder  the  same 
obligations  and  responsibilities.  No  one  asks  a 
citizen  whether  he  is  native  born  or  naturalized. 
He^s  an  American  citizen,  and  that's  that! 
Another  case  which  comes  to  mind,  unfor- 
tunately still  not  expunged  from  American  life 
compietely^  is  the  regrettable  holdover  from  the 
unspeakably  horrid  days  of  Puritanism,  when 
the  innocent  and  blameless  offspring  of 
unmarried  parents  were  stigmatized  with  the 
label  of  illegitimacy.  Though  they  were  not 
different  in  any  way  from  others,  they  were 
regarded  as  inferiors,  and  because  of  this  bar- 
baric practice,  were  denied  status  in  society  in 
an  unbelievably  broad  spectrum  of  areas 
. .  jobs,  education,  social  acceptance,  marriage* 
civil  service,  freedom  from  the  mischievous, 
wagging  tongues  of  the  vicious  hypocrites  who 
enjoy  making  others  miserable  at  every  oppor- 
tunity. 

Let  us  grant  that  tlie  mail  exams  have  been 
on  the  up  and  up  .  -  .that  not  a  single  Condi- 
tional was  party  to  any  hanky-panky.  Despite 
this  concession,  there  will  always  be  those  who 
will  wink,  place  their  fingers  alongside  of  their 
noses  and  nod  knowingly.  So  long  as  someone 
wears  that  designation  on  his  sleeve  he  is  fated 
to  be  suspected  of  having  cheated.  Since  we 
have  just  finished  granting  that  such  is  not  the 
case»  and  since  all  the  Conditionals  have 
applauded  my  eminent  fairness  with  eathusiasm^ 
the  next  logical  step  would  be  to  require  some 
of  them  (ju*it  a  few  ,  ,  ,75%,  for  example)  to 
prove  that  our  utter  confidence  in  their  inte* 
grity  was  well  merited.  Boy,  1  can  hear  the 
gnasiiing  of  teeth  and  the  blue  vitriol  ascending 
into  the  air  right  now,  really  I  can. 

Why  in  the  name  of  Tophet  cannot  some 
machinery  be  devised  for  the  purpose  of  taking 
the  exam  to  the  applicant  who  cannot  come  in 
under  his  own  steam.  If  a  single  volunteer 
examiner  is  regarded  as  untrustworthy,  why  not 
employ  the  services  of  (if  you  will  forgive  a 
Russian  term)  a  *  troika*  .  .  .three  people  are 
hardly  likely  to  risk  any  joint  dishonesty  for 
fear  of  subsequent  disclosure.  They  could 
undertake  to  administer  the  test  to  the  truly 
handicapped  person  who  cannot  possibly  get  to 
the  examining  point  And  the  exam  should  be 
given  the  same  weight  as  the  regular  FCC  exarn^ 
with  all  credils  applicable  for  higher  grades. 
This  should  be  limited  to  absolute  establishment 
of  the  candidates'  inability  to  get  to  the  l-CC 
office.  All  others  should  be  required  to  meet 
the  standards  that  have  been  established  for  the 
upper    three    license    grades.    If    necessary,    as 


seems  likely,  some  of  the  additional  revenues 
now  being  reaped  from  the  increases  in  renewal 
fees  {up  125%)  could  be  apphed  to  the 
establishment  of  additional  exam  centers,  and 
could  be  u.sed  to  help  defray  the  salaries  of 
additional  personnel.  Then,  when  the  test  is 
taken,  either  by  the  troika  method  or  the  FCC 
method,  let  the  appHcant  be  issued  a  General 
class  license,  completely  indistinguishable  from 
othets,  destigmatized  and  totally  immune  to  the 
jibes  and  insults  of  any  *Tirst'Class"  amateurs 
who  might  feel  an  inclination  to  accuse  them  of 
skullduggery. 

The  fact  is  that  we  cannot,  in  good  con- 
science, permit  a  large  number  of  operators^ 
comprising  hterally  thousands  of  individuals,  to 
continue  to  enjoy  a  privilege  which  is  earned  by 
the  vast  majority,  simply  by  feigning  physical 
disabilities  which,  in  far  too  many  instances, 
exist  only  in  their  wishful  imaginations.  We 
cannot  continue  to  tolerate  equality  of  partici- 
pation by  those  who  waltz  blithely  through  the 
mile-wide  loopholes  of  the  law,  which  conven- 
iently allow  them  to  take  the  ticket  while 
ignoring  the  basic  technical  requirements.  No 
matter  how  sorely  handicapped  an  individual 
might  be,  he  should  at  least  be  required  to 
conform  to  a  standard  within  the  limits  of  his 
own  ability  and  competence.  To  offer  him  a 
completely  free  pass,  an  Annie  Oakley,  is  not 
only  derogatory  to  the  rest  of  us  ,  .  ,it  is  an 
insult  to  the  integrity  of  every  single  Condition- 
al with  a  legitimate  reason  for  holding  that 
grade  ,  ,  -and  there  are  many,  many  of  them. 

I  am  sure   that  we  all  know  sightless  hams, 

amputees,    victims    of    dread    disease,    shut-ins 

-  .  .who   have   spurned    the    Conditional   license, 

and  who  have  insisted  upon  being  examined  in 

the  standard  fashion,  just  like  everyone  else,  in 

order     to     avoid     being     deemed     cripples    or 

invalids.  We  are  all  mighty  proud  of  them,  for 

Uiey    are    a    source    of   inspiration,    and    their 

achievements  set  an  example  of  courage  for  all 

of  us.   Within   the   framework  of  that   type  of 

pluck  and  determination,  how  can  we  possibly 

dare     to     countenance     the     flimsy    alibis    and 

"plea-copping"   of  the   indolent,  unindustrious, 

shallow^    cheats    who    masquerade    behind    the 

technicalities    of   legalistic   gobbledegook,    even 

tliough  it  may  be  within  the  definable  semantic 

terms  of  the  FCC  regulations? 

Isn't  it  time  some  changes  were  made? 

*    *    * 

I  never  saw^  the  beat  of  it;  when  you  write 
comment^  many  people  take  it  as  a  persona! 
point  of  privilege  to  challenge  you  on  every* 
tiling  .  -  .opinion  as  well  as  fact  It  is  as  though 
an  editorialist  had  no  right  to  express  his  own 
ideas  . .  .that  somehow  when  he  allows  his  name 
to  appear  on  the  printed  page,  he  must  express 
only  til  at  which  coincides  with  what  they  think 
. ,  .all  other  ideas  become  invalid! 

Really,  you  have  no  idea  of  the  tone  of 
reproof,    sometimes   downright   abusive,    which 


DECEMBER    1970 


105 


1 


even  one's  best  friends  are  likely  to  use  in 
disagreeing  with  this  or  that  editorial  point  of 
view  on  any  given  subject.  Take  the  recent 
growth  of  lists  on  the  DX  bands,  for  example. 
This  has  now  become  the  chief  target  for  the 
rugged  individualist  types  who  keep  insisting 
that  they  prefer  pileups. 

1  have  no  axe  to  grind  either  way,  I  have 
such  a  minuscule  number  of  DX  credits,  that 
Vm  happy  to  take  'em  any  way  I  can  get  *em. 
So  my  views  are  not  subjective  . ,  .not  based 
upon  my  own  needs  . ,  .therefore  unprejudiced. 

While  it  is  perfectly  true  that  a  well  opera* 
ted  station  using  standard  power,  a  medium 
height  tower  and  an  ordinary  tri-band  antenna, 
is  adequate  in  the  average  hurly-burly  of  a 
minor  or  medium-size  pileup,  it  is  decidedly  at 
a  disadvantage  in  the  prodigious  traffic  jam 
which  inevitably  occurs  whenever  a  rare  one 
turns  up.  The  recent  operations  at  ZA,  AC3, 
ICP6>  ZKl,  and  Gus  Browning*s  Indian  Ocean 
activities  all  demonstrated  the  folly  of  attempt- 
ing to  compete  on  an  equal  basis  with  the 
super-kilowatt  boys  with  the  sophisticated 
antenna  systems.  Those  boys  stick  out  like  a 
sore  thumb  .  ,  .many  "dB"  stronger  than  the 
other  hundreds  of  poor  sh nooks  calling  in  the 
pileup* 

In  such  cases,  the  list  method  tends  to  favor 
the  less  powerful  stations^  enabling  them  to 
make  QSOs  which  they  would  have  very  little 
hope  of  getting  under  normal  circumstances.  Of 
course,  this  displeases  some  of  the  big  noises, 
who  evidently  feel  that  they  do  not  wish  to 
lower  themselves  by  soliciting  anyone's  aid  for 
the  demeaning  purpose  of  standing  in  line  to 
make  a  contact  ,  ,  ,any  contact  They  seem  to 
think  that  they  should  not  be  required  to  wait 
in  line,  but  should  be  accorded  instantaneous 
and  undivided  attention  by  whomever  they  call. 
They  are  perfectly  willing  to  have  everyone  else 
stand  in  a  long  queue,  twiddling  the  thumbs, 
just  so  long  as  it  is  not  they  who  are  made  to 
wait  And  whenever  these  certain  parties  hear  a 
list  operation  in  progress,  a  couple  of  them 
invariably  try  to  break  right  in  and  call  right  on 
top  of  everybody,  simply  because  they  are  just 
not  about  to  get  used  to  waiting  their  turn. 
When  they  are  asked  to  move  off  because  the 
DX  is  working  to  a  list,  they  commence 
lecturing  all  and  sundry  on  the  evils  of  lists,  and 
how  this  is  likely  to  destroy  amatuer  radio.  Or, 
they  move  off  about  t\%o  kilohertz  and  QRM 
the  frequency  with  all  of  their  side  hash. 

If  ever  there  was  a  sterling  reason  for  me  to 
feel  kindly  disposed  toward  the  lists,  this  would 
be  it  1  think  that  it  is  high  time  that  some  of 
these  super-mouths* oh  the  bands  were  made  to 
feel  a  tittle  less  secure  about  their  positions  on 
invincibility.  lt*s  time  somebody  gave  them  a 
comeuppance. 

Well,  anyway,  to  get  back  to  the  lists  . .  J 
decided  that  maybe  I  would  support  a  couple 
of  them,   not  just   to  get   in   on  the  DXj  but 


because  I  happen  to  be  a  strong  advocate  of 
their  sponsorship  of  DX  stations  by  distributing 
gear  to  them.  So,  I  sent  in  a  few  bucks  , .  ,not  a 
large  amount  at  all,  and  I  had  the  unmitigated 
temerity  to  announce  the  fact  on  the  air  to  a 
few  fellows  1  know.  Boy!  That*s  when  the  eggs 
hit  the  fan!  They  wouldn't  even  control  them- 
selves to  the  extent  of  waiting  their  turn  to  tell 
me  off.  They  said  1  was  stupid,  shortsighted, 
foolish,  naive,  ignorant,  radical,  vicious,  treason- 
able, and  that  1  was  losing  my  marbles.  They 
doubled,  tripled*  and  quadrupled,  drowning 
each  other  out  in  a  caca phony  of  indignant 
outrage. 

Well,  if  there's  one  thing  IVe  learned  since 
beginning  this  column,  it  is  this:  Whenever  you 
get  an  angry  reaction  as  a  result  of  something 
youVe  written,  you  can  be  pretty  sure  you're 
on  the  right  track!  Nothing  gets  people  who 
have  enjoyed  an  advantage  (particularly  an 
unfair  advantage)  more  upset  and  riled  than  a 
movement  toward  equalizing  the  situation. 

Of  course,  even  if  the  edge  could  be  taken 
away,  they  would  somehow  find  a  way  to 
regain  it  I  know  a  couple  of  guys  who  would 
do  it  legally,  by  developing  more  efficiency  in 
the  antenna  system,  and  that's  fine  with  me* 
But  the  answer  for  many  of  them  *  *  ,far  too 
many  . .  •would  be  an  illegal  increase  in  power. 
Don't  ever  get  the  idea  that  the  so-called 
California  kilowatt  is  confined  to  the  Golden 
State.  The  overpowered  stations  are  all  over  the 
map,  and  what's  more,  everyone  knows  it  And 
as  long  as  there  are  people  who  are  willing  to 
sidestep  the  regulations  by  running  illegal 
power,  then  I  am  solidly  in  favor  of  list-taking, 
because  it  is  just  about  the  best  way  yet  devised 
for  overcoming  the  overwhelming  odds  which 
have  been  unfairly  lengthened  by  these  cheats 
and  chiselers. 


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your  car  when  you  are  on  a  trip 
and  meet  tfie  tiams  afong  tfie  way. 
Comes  rig  fit  off  wfien  tfie  XYL 
drives  tfie  car,  if  sfie  doesn't  want 
to  be  bottiered  by  fiams  tooting  at 
fier. 

Send  $4  afong  with  your  caff 
fetters  today.  Radio  Boofcshop, 
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106 


73  MAGAZINE 


Gerald  Beene 
Greenville  TX  75401 


Many  power  supplies  wiU  not  survive  a 
short  circuit.  The  reason  for  this  is 
that   in   the  low  voflige  supplies  used  for 


02 


Fig,  1,  Series  current  luniter  circuit. 


transistor  circuit  work,  a  series  transistor  is 
used  to  regulate  the  output  voltage.  If  an 
unusually  large  current  is  demanded  from 
the  supply,  and  there  is  no  current  limiting, 


UMfTER 

TO 

+ 
POWER 

SUPPLY 

1 

£ 

CKT 

± 

Fig.  2.  Biock  diagram  of  iimiter  in  typical  applica- 
tion. 


the   peak  current  rating  of  the  regulating 
transistor  may  be  exceeded. 

Other  than  the  sensitivity  of  some  power 
supplies  to  overload,  experimental  circuits 
are  also  subject  to  damage  if  for  some 
reason  excess  current  is  allowed  to  flow. 


A  fuse  alone  will  not  necessarily  provide 
the  needed  protection  for  current  setisitive 
semiconductors. 

The  simple  two-terminal  current  iimiter 
shown  in  Fig,  1  will  give  instantaneous 
limiting  for  those  slips  of  the  probe,  sudden 
shorts,  etc.  The  use  of  a  fuse  in  series  with 
the  Iimiter  will  reduce  the  need  for  a  heat- 
sink  on  the  transistor  Ql. 

The  Iimiter  is  placed  in  series  with  the 
line  so  the  current  is  from  collector  to 
emitter.  Though  shown  polarized  in  Fig, 
2,  the  Emiter  may  be  used  with  either 
polarity  supply. 

In  order  to  design  for  a  particular 
maximum  current,  select  Re  such  that 

.6V 
^     I  (amps) 

and  make  R^  about  ten  times  as  large 
as   Rg,    CRl    and  CR2   are  silicon  diodes 

such  as  1N4002,  1N645,  1N2070,  or  just 
about  any  diode  capable  of  at  least  100 
mA.  Ql  is  a  sUicon  transistor  capable  of 
the  current  to  which  the  Iimiter  is 
designed. 

It  works  like  this,  Ri,  is  small  enough  to 
keep  Ql  saturated  as  long  as  CRl  and  CR2 
are  not  conducting.  As  soon  as  the  voltages 
drop  on  R^  reaches  0,6V,  CRl  and  CR2 
conduct  and  regulate  the  output  current  by 
regulating  the  base  voltage  on  QK 

Gerald  Beene  ■ 


I 


DECEMBER    1970 


107 


1 


XK 


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ARTICLE 

DIRECTORY 

1970 


This  master  article  directory  lists,  by  subject,  all  the  major  articles  featured  in 
73  Magazine  during  1970,  Entries  are  first  by  subject  (alphabetically^  then  by 
article  title  (chronologically).  A  brief  abstract  of  each  article  appears  once, 
though  the  article  itself  might  be  listed  under  more  than  one  category.  When 
no  abstract  appears  and  a  subject  heading  is  shown  in  parentheses  between 
the  author's  call  and  the  date  of  publication,  refer  to  the  parenthesized  sub- 
ject heading  to  read  the  abstract. 


Antennas 

AAB— AM— FM  Modulalion  System 
W2B5P  Jan 

TonBue-in-che*k  technical  article  about  a  system 
th*  author  actually  uses,  H*  calls  it  **freqwency 
apertio'e'"  modulalicm.  The  mait  interesting  part 
of  Ihc  article  is  ihe  Authot\  clever  adapialion  ol 
a  &5  eallon  drum  for  use  as  a  10  meter  cavity. 

Base*Tuned  Center- Loaded  ARtenittl 
WZEEY  Jan 

An  antenna  can  be  c*»ntpr-kj*idi*d  without  hiiving 
the  reactive  elemeni  physitally  prescni  ,it  the 
center  at  the  antenna.  Transmission  line  transfer 
of  the  reactive  element  is  the:  Jiey. 

Variable*! mpedauce  Mobile  Mount 
WIEMV  Frb 

A  roLan*'  twitch  with  a  few  capacitcirs  can 
effectivetv  change  the  matching  trnpe^-inei-  «>£  a 
mcibile  antenna, 

Qiiick'Stap  and  Reverse  Antenna  Rotator  Circuit 
rV2AUC  Feb 

A  yimple  rot4*r  itindificatmn  in  make  the  antenna 
stop  when  yOti  w^nt  it  tt>.  A  No  lets  you  suddenly 
rrvtine  the  antenna's  travel  without  fearing, 
damage  to  anythtne  too  hi^  to  reach  eamfor- 
tabiy. 

The  Glop  Will  Get  You  if  Vou  Oon*t  Watch  Out! 
W20LU  Ftb 

Thi^  effects  of  Klup  (dirl  and  crud)  on  antenna 
connections.  Contain;;  suggestions.  lor  mmimi/ine 
the  likelihood  of  Glop  buiId-up. 


18*in.  Dipole  for  15  Meters 
K9LGH  F«b 

Rupt-rsmatl  Hnirnna  for  cliffdw**!lrr!>^  incorporates 
two  prinied^cijTcuil  radiaUitii  elentents. 

Loiiy  f  ransmissDn  Lin^^ 
KH6IJ  Feb 

A    deschptjon    of    the    ef  fet'ts    of    an-  ajiienna 

tiansniission  lme*s  losses^  and  a  discussion  as  to 
the  insignilicartce  of  svtr  meA$uremenU  under 
con di Lions  i>f  a  lossy  line. 


How  to  Megger  Your  Antenna 
W2EEY  Apr 

A  simple,  pjfoved  method  for  period icajly  fht'tk- 
ine  performance  of  a  iransmisBion  line  iind 
antenna  system.  Can  uncover  fautts  not  indie  -iii'rt 
by  svvr  measure  men  Is. 


7 /S -Wave  Mobile  Antenna  for  2  meter  FM 
W2E1UP  Apr 

An  r Xpert  describes  an  antenna  of  original  design, 
and  compares  it  nfojectively  wnh  other  antennas. 
of  commerciiil  m.anufaeture,  In  the  Buffalo  tirea, 
this  7/&'wave  antenna  has  held  the  FM  mobile 
^in  record  sinee  1^67. 


5;8  Wavelength  Verlicals 
WAt^NGV  May 

1  hi'ory  and  information  on  5|ffl'wave  verticals  of 
various  descriptions.  Includes  radiatjon^angle 
data,  construction  informaiion.  and  necessary 
equations  for  original  design. 


DECEMBER    1970 


109 


Vi^ 


1 


TH«  LittJr  Wondrr:  Mark  U 
W5ZBC  Jun 

Another  cliff  dweller  antenna.  ThU  ame  can  br 
tlt$hioned  from  an  oM  po!f>  lamp. 

The  663  Bpam 
ZL2ASJ  Jun 

Six  i^l^menls  nn  tO  aJid  !5.  and  3  elements  on 
20ni.  Canstrucli[»n  plains  were  left  out,  but  w*ri 
printed  in  the  Aug  issue  4 p.  S3). 

Qtiarter^W^ive  Top-Loaded  MoblU^  Antenna 
WSAZE  Jun 

An  effjcienL,  ifth«rt  quarter-wuveleneth  dipuk- 
antennti  for  20  meters. 

Eleven -Element  2  meter  Circylar  Quad 
W4itAE  Jun 

A  new  type  tit  ^miemna  that  seems  to  have  a  lol 
ti»  offet . 

TIm  Sly  Beam 
ZL4TAH  Jun 

21  dB  gmn  an  2  nueLeTs  with  a  new  approach  to 
the  constfufrtion  of  y»gils« 

lieasorinc  the  Difference  Between  Incident 

And  Reflected  Powrr 

vrins  Jun 

The  difference  is  the  differenre  Trtrludes  circuit 
for  mea^urtng  n? fleeted  and  f^^rwrtrd  rf. 

The  EfrectK  nf  Temper^itnre  und  Frequency 
On  Coaxial  Call  1 1^  Lo.tsi 
W9KXJ  Jun 

As  Irdnsmisajon  line  tempers Lun-  inrrtases,  so 
does  loi5  —  and  vice  versa.  Complieatiiie  matters, 
the  losses  get  worse  as  the  operating  frequeney  i» 
raised,  includes  eharts- 

Jmprovxnf  the  Ferfarmnincc  of  Trap-Typt 

Vertieal  AntennaA 

W2EEY  Jun 

The  addition  of  another  element  can  consider- 
ably improve  the  performanee  of  multiband 
verticals.  The  added  element  c^n  be  automati- 
eallv  band  switched  aiid  a  transmission  tine 
system  ujed  which  ^tows  ^mple  ehanaeovef 
from  an  omnidireetional  to  a  directive  radiation 
pat  tern « 

A  Practical  DDRH  Antenna 
W6WYQ  Jun 

Ring-type  Inw-prutiW  radiator  thai  i&  hard  to 
build.  Good  for  mobile  rooftupa^ 

Two  Receivers  from  One  Antenna 
WA6IIFW  Jun 

An  easy-to-make  sjenat  splitter  that  allows  niaxi- 
mum  utilization  and  minimum  loss. 

Remote  SWR  Indieator 

vnmsY  jyti 

Concentionallv  pUced  swr  meters  iiften  do  not 
ir^cate  the  true  swr  at  the  lync^tion  of  the 
ttmnfmission  bne  and  antenna.  Remote  location 
of  the  re  fleeted -pnwer  sensing  ^sortion  of  an  s:wr 
unkt  is  the  key  tu  true  sw^r  v^ue  IndicaUan. 

The  Low-Noise  Antenna 
WBGJNJ  Jun 

B-lasting  the  theory  that  an  antenna  always  works 
aa  well  receiving  as  it  does  transmitting, 

MfaSuTioE  RF  Output 
WA6CPP  Jun 

U^ing  a  cheapie  meter  to  measure  wattage. 


Raising  a  Rhombic 
WflDYF 
All  you  really  need  is  space. 


Atn 


Log  Periodic  Antenna  De^gn*  fov  VHF/URF 
W3DUQ  Auf 

Three  Arrays  are  featured:  21—55  MHz.  50—150 
MHz,  and  150-450  MHz. 

ATV:  GettinE  a  Better  Picture 
WA6BJV  Aug 

Plani  for  a  lood  antenna  and  suggestions  for 
other  station  improvements. 

Brew  I  on  2  ^^  a  2  Meter  Coaxial  Antenna 
WA9RWQ  Sep 

The  title  is  alluding  to  California's  '^Brew  102*^' 
beer.  The  ^irtiele  describes  u  beer-t^an  coaxUil 
antenna  that  can  be  fun  to  make  if  you  obtain 
the  cans  as  the  author  suggests. 

Four-Wire  Inverted  Vee 
WABCOB  Oct 

Simple  but  effective  antenna  for  4B  and  BO 
meters. 

Remote  Quad  Tuning 
W6AJZ  Nov 

How  lo  tune  a  quad  stub  from  a  control  bon 
gat ua ted  at  the  operating  console. 


CW 

The  Combo 
K4FQU  Jan 

A  CW  monitor  that  is  installed  hetween  the  key 
and  the  traruimittei-.  Contains  but  one  transistor. 
Simple.  Effective, 

Mobile  CW 
KGRA  Jan 

A  fantasttcallv  great  way  to  get  yourself  killed  »n 
a  Los  Angeltr:^  Freeway. 

Fint  Clasa  Keyer  Key 
W6BLZ  Jan 

Quickie  article  describes  a  cute  modification  to 
fnodernize  an  mcKpcnsive  but  readilv  available 
"by|U  ■ 

A  CW  Monitof 
WB2GQY  Mar 

How  to  get  a  08 if  oscillatoi  module  to  key  on  and 
off  w^ith  rf.  Uies  a  voltage  doubter  rf  pickup. 


Tltmlni  the  AN/GRC^  Into  A 

Novice  Ria, 

W6JTT  Mai 

A  simple  converfion  puts  this  surplus  unit  on  80 
and  40  meterit.  Converted,  the  rig  will  run  about 
I5W.  Includes  n  det^led  power  supply  circuit, 
Modula  tori  ess,  the  transmitter  Is  intended  for  CW 
operation  i. 

What  Will  Become  of  CW? 
W5TOM  May 

A  di^tfi^rtiiticm  on  the  st^te  of  hum  radio  todity^ 
pod  sugge^stions  tor  possible  Improvement.  I^fukcs 
a  case  —  of  sorts  —  for  CW,  aiKl  offers  predictions 
for  CWs  role  in  amateur  radii^'.s  future. 

A  Mobile  CW  Transmitter 
W6BLZ  May 

For  those  who  donH  know  what  to  do  with  their 
free  hands  while  drivings 


CW  Can  Be  Fun 
Staff 
An  evaluation  of  Ord*s  DK-I  keyer. 


Jan 


QRF 
WA3JBN  Jun 

Two  simple  rigs  for  CW  opeoition  on  40  meters. 

How  in  Biiild  a  Keyer  and  Retain  Your 

Status  tts  an  Appliance  Operator 

WSKXJ  Jul 

A  couple  of  guitar  picks  and  »iome  relay  contacts 

can  turn  nut  a  pretty  nice  looking  liending  key. 

Mobile  CW  Receiver 
W6BLZ  Jul 

For  people  who  just  can't  seem  to  get  enoufh 
code  during  the  evening  at  home, 

the  ICmittef 
Goldstein  Aug 

Costs  hi  tie  and  do^-sn't  run  much  power,  but  It 
will  put  out  a  signal  —  AM  ot  CW  —  on  40 
through  160  meters. 

Integraled  Circuit  CW  ID  Generator 
W7PUG  Sep 

A  device  for  automatic  identification  —  with 
CW  —  of  FM  repeaters.  Author  also  offers^  to 
supply  PC  boards  plus  computer  printout  of  any 
call  letters,  as  optiTni?,ed  with  the  author's  tiom* 
puter. 

Low-Cost  Automatic  ICeyer: 

A  Firsi  Project 

WB4MYL  Nov 

Schematic,  description,  and  circutl  board  layouts 
for  an  ine^penvive  keye?  thai  can  send  from  10 
wpm  to  over  30, 

DX 

How  to  Visit  Foreign  Countriet 
W2NSEI/I  Feb 

A  few  salient  hmts  for  prospective  travelers  and 
sometimes  DX>rs» 

Ham  Exchangp 
WA2ELA  Miir 

First-hand  report  of  a  "^ham  ps change"  whereby 
DX  visitors  slay  i^ith  U.S.  amatt'urs,  then  recipro- 
cute  later  when  the  U.S.  hams  visit  the  DX 
country, 

QSLing:  Ham  Radio's  Own  Con  Game 
VK4SS  Jul 

One  ham's  negative  opinion  of  the  state  of  DXing 
today. 

Latham  Island  DXpedition 
5HaLV  Jul 

Problems  and  iucccs&es  Ln  a  recent  DX  trip  to 
Zanzibar, 

Worldwide  ITU  Prefix/Call  Area  List 
WISWX  Jul 

Reprinted  from  DX'er  Maga/Jne. 

YO  —  An  Interesting  DX 
Y02B0  Oct 

A  look  at  Roniitnia  and  a  deKcnption  of  the  h^ms 
jjnd  country^ 

FM 

VHF— FM:  A  New  Involvement 
K6MVH  Jan 

The    story    of    FM    Maga^ne^s   demise    and    the 

promise  of  73  to  give  adeqi^ate  attention  lo  FM. 
an  area  alt  but  neglected  by  ham  joumaJs  in  the 
past. 

Low-Cost  Electronlci: 

Japan *s  FM  Invasion 

K6MVH  Jan 

A  brief  overview  of  some  of  the  2m  FM 
triin^cetvers  th^^t  lire  being  inported  for  sale  to  the 
booming  VHF  hiim  market, 

Setting    Up  the  Tone-Burft  System 
W6TEE  Feb 

The  little  details  that  are  necessary  in  setting  up  a 
toned  repeater^  including,  a  tone-burst  timer  for 
the  user  mobiles. 

Tone  Decoder  for  Remota 

Switching  AppbrptiDns 
KBMVH  Feb 

A  simple  and  tested  tone  decoder  that  may  be 
used  for  such  repeater  control  supplications  as 
whistle-on  and  tone-burst  arceKSi  systems. 


Hitooders  for  Subaudible,  Tone-Burst 

or  Whistle-On  Use 

W6CZL  Feb 

An  extremely  simple  and  stable  transistor  oscil> 
laior  circuit,  with  adaptations  for  the  varioui 
modes    of    repealer    controL    tncludc:5   PC    board 

layout  and  construction  plans, 

Freqiuency  Synthesis: 
The  Modem  Way  to  Control  Frequency 
W2EUP  Feb 

A  complete  anti  comprehensive  article  covering 
theory  and  techniques  of  indirect  frequency 
synthesis,  plus  schematics  and  u  deschpLion  of  a 
practical  tOO-c'hanne|  synthesizer  used  in  a  2 
metet  FM  tF.tnsi  eiver»  with  only  one  frequency- 
determining  ci y^i^ 

VHr— FM  and  You 
K9STH  Mar 

A  "wh«t*s^t-a^^ilboul'*''  lype  article  covering 
everything  that's  happening  in  FM  tigbl  now. 

6*tO'12-»volt  Filament  Conversion 

for  the  -11  V 

W6YAN  Mar 

Changing  the  cheaper  6V  Motojhala  FM  units  to 

12V  types. 

AC  Power  Supply  Conversion 

for  the  Motorola  41 V 

K9PKQ  Mar 

Schematic  diagram  and  helpful  hints  for  con* 
verting  Motorola^!  truhk-mounlinf  mobile  unit  to 
a  base  station. 


Remote  Muttjfrequeney  Oscillator 
W2Al,M  «.»Sun.lu»FMOml.  ^^ 

Complete  plans^  PC  layouts,  and  construction 
info  for  a  four-frequency  osciUator  deck  thai  can 
be  used  in  the  control  head  of  such  trunk* 
mounted  units  as  GE.  Motorola.  Link. 

Converting  the  Snnoliuoy 
to  a  2W  FM  Transmit tef 
WlBYX  Mar 

Schematic  diagram,  photo,  and  instructions  for 
converting  the  AN/SSQ-23A  underwater  trans- 
miller  to  A  2W  2  meter  FM  rig.  Also  tells  where 
to  get  such  transmitters. 

Kfli  Smiming  Receiver 
Staff  Mar 

A  close  look  at  one  of  the  newest  entrants  into 
the  hjun  radio  field, 

A  Look  at  Amatem  FM  Standards 
WB6DJT  Max 

A  general  survey  of  the  VHF  revolution  with 
respect  lo  repeaters  over  the  pat;  few  years  and 
some  sugge«tioni  for  planning  ahead. 

A  Poor  Man's  Frequency  Meter 
W6YAN  Mar 

How  to  turn  a  che*ap  LM  frequent u  meter  into  an 
extremely  accurate  piece  of  ipsit  equipment. 
You'll  need  the  front  end  from  a  Sensicon 
receiver,  too. 

The  Fine  Points  of  FM  Operation 
WB2AEB  Apr 

Good  common  sen«  for  FM  befinners.  Includes 
good  hints  on  setting  deviation  level. 

Examining  FM  Repeater  Operation 
WB6PJT  Apt 

A  state-of-the-art  article  telling  il  like  it  ii,  with 

sugjg^stioiiB  as  to  how  it  ought  lo  be, 

A  Repeater  Controller 
WA4YND  Apr 

The  myriads  of  mechantcul  contrivances  thai 
repeaters  inevitably  wind  up  with  can  be  replneed 
with  transistor  cquivalentfi.  .  .with  a  resulting 
increase  in  system  reh^bilitv  and  decreases  in 
headaches  for  the  repairman.  Complete  circniu, 
with  timers.  COR ,  keyer  control,  etc. 

Understanding  the  Carxter^Operatcdt 
Repeater 
K6MVH  Apr 

The  complicated  repeater  is  not  rvally  so  com^ 
p|e:K  after  all.  .  .it's  only  a  matter  of  under- 
fl*nding  the  simple  op  era  lions  that  are  taking 
place  when  i.»mebody  tr^ntmitc  on  the  input 
fere<juency. 

Evaluations  Standard  2m  FM  Transceiver 
WfiQGN  Apr 

A  cioiii>  ItKik  at  the  SR-C-ftOfiM  transistor  triin* 
sceiver* 

Directory  of  American  Open  Repeaters 
Staff  Apr 

A  comprehensive  listing  of  open  repeaters  in  the 
United  State*  and  Canada.  Includes  editorial 
introductjon  and  vnjteup  afaoiil  repeaters  in 
geneiaiL 

FM  Repeateca  Under  Fire  From  FCC 
Staff  Apr 

The  first  pubhshed  notice  of  FCC's  infamous 
Docket   IB803.  Sketchy  but  eEsentially  accurate. 


no 


73  MAGAZINE 


A  Woird  AbciuL  Repeaurs 

WB2AEa  AP* 

The  trend  for  the  future  seems  to  be  to  use  a 
compaiibie  denatiort  eif  both  narrowband  and 
wideband  rigs:  this  is  Accomplished  with  a  pe^k 
devintion  of  about  8  kH?.  at  the  repeater  iran- 
smitter.  Other  trends  and  characteriiiics  alio 
naied.  tnclwded  with  the  repeater  directory* 


7 /B -Wave  Mobile  Antennft  for  2  melef  FH 
W2EUF  Ai*' 

(Antennai) 

FM— AM  Transmitter-Receiver  AUftnet 
W3JKl^  May 

A  fieiial  generator  that  can  be  used  in  cofijunc- 
tion  wiih  #  transmitter  to  givt  m  zero  beat  for 
frecLuency  measurement*,  AUo  uicfut  for  alieumg 
F.M  receivers. 

The  intemgeiit  Vam  of  2  Meters  FM 
KIZJH  May 

A  eeneral  description  of  the  wif  it's  done  un  FM 
(it  IS  different^  ajid  a  few  word*  of  wiidom  to 
people  who  arenH  used  to  working  throuftb 
rrpitaters. 

A  Low-Band  fohce  MonlloT 
W6JTT  May 

How  to  modify  Motorola**  old.  no  lonfer  used 
30O  type  receivers  bv  buildmc  Up  a  simple 
supply  and  diddling  with  the  receiver  oscillatof. 

Thf  Wichita  AutopAieh 

w«DKu  ^^y 

Tied  in  with  the  local  repeaicf ,  this  phone  patch 
receiwed  approval  from  Ma  Bell.  Include*  descrip- 
tions of  the  patch  and  tells  ho*  Ma  BeU  was 
canoed  into  going  along  with  the  idea. 

An  FM  Beit  Buy 
WATCliM  May 

Bojf  to  convert  the  world**  rarest  FM  rig 
(ComcoJ  from  commercial  service  to  the  ham 
band. 

FET  Preamps  for  VHF  FM 
WA4WDK  May 

Two  good  preamps  are  described  —  one  for  S  and 
the  other  for  2  meters.  Complete  performance 
curves,  construction  data,  schematics*  etc*  are 
given.  Preamps  are  grounded -gate,  which  offers 
high  Rain>  ease  of  Lunins,  and  simpUcjtv  of 
constructioTii 


K9STH 


Allied  Portable  FM  Hecelveir 


Jul 


An    evaluation    of    AlUed's    A-26e7    pocket    FM 
receiver. 


Jul 


A  Two-ChanneJ  Search-Lock 
for  FM  Receivers 
W3DTN 

Simple  gadget  turns  a  S-channel  rig  into  an 
automatic  scanner  type,  and  provides  the  added 
capabUity  of  locking  onto  a  channel  where 
activity  is  sensed. 

Super  Autopatch 

K6MVH  ;f"* 

Why  automatic  phone  patches  are  important  for 
public  service.  Includes  construction  data  for  a 
p4itch  thai  does  everything. 

Repeater  Audio: 
Time  Out  for  Quality 

KfiM  VH  ^  '^' 

Use  of  a  cathode  follower  to  pick  audio  du-ectly 
from  the  repeater*s  discriminator  can  do  wonders 
lor  an  ailing  amateur  relay  system. 

Optimising  Antrnna  Separation  * 

in  FM  Rrpcaters 
K6HVtl  Sep 

If  the  receiving  range  of  your  repealer  cant 
match  the  output  capability,  the  problem  could 
be  desensitj/ation.  And  chances  are  you  cart  solve 
tfve  problem  by  as  simple  a  step  as  moving  the 
antennas  around  a  little  at  the  repeater  site. 

DyComm's  15W  2  M«t«r  Minl-AmpMfier 
Staff  ^eP 

Afl  evaluation  of  a  ready-made  15W  class  C 
■mpUlier  that  can  be  used  for  VHF  CW  or  FM 
applicationsn,  requiring  only  20  mW  of  drive. 

JmegraUd  Circuit  CW  ID  Generator 
W7PUG  Sep 

{CW) 

Low*Co£t  pseiliator  it  Infintic  Attenuat^ir 
for  Tuning  VHF  Receivers 
KICLL  Sep 

A  signal  generator  with  A  very  reliable  ^ad 
repeatable  attenuation  device  for  adjusting 
receiver  front  ends  lo  maximiie  scnsitivily. 

Controlling  Hepeatert  with  Tones 
K6MVH  O"^ 

Basic  repeater  control  logic,  and  how  to  set  up  a 
tone  control  system  for  tone-burst  or  whtstle-^n 
use» 


Semiautomatic  FM  Channel  Scanning 
WA^QFM  Nov 

Usmfi  ordinary  flasher  module,  this  unit  connects 
to  a  lwo*channel  FM  transceiver  to  allow  moni- 
toring of  both  channels  bv  a  scanning  setjuence. 
Does^  not  lock  onto  a  signal. 

■ 

2-Meter  Mini  transmitter 

for  Repeater  Use 

WSGSIH  Dec 

A    straightforward,   simple   transmitter   with  five 

stages  using  five  transistors. 

Regency  —  m  FM  Late -Starter 
Staff  ***« 

A  comprehensive  comparison  of  the  Regency  2 
meter  transceiver  with  other  units  currently 
a  vd  Liable. 

General  Info 

Fascinating  Fundamentals; 
VoiU  and  His  File 
W2FEZ  Jan 

The  interesting  story  of  Voila  and  his  ex  pen- 
ments  in  galvanic  resifarch.  Describe*  an  early 
(and  easily  duplicated)  battery. 


Fascinating  Fundament^Ls* 
The    Terrible    Jar    at    Leyden 


¥V2F£Z 


Feb 


Interesting  historical  facts  about  the  Leyden  Jar; 
how  to  duplicate  it  and  make  you?  own  capaci* 
tor. 

How  Do  Ham  Radio  Stores 
Decide  Trade-in  Frices? 
W2CEP  Apr 

The  owner  of  Stellar  Industries  gave  this  run- 
down on  the  way  pnces  aJre  figured  in  the 
amateur  radio  game.  Stellar  ii  no  longer  in  the 
ham  business,  but  the  article  is  nonetheless 
applicable* 

fieryllia  —  The  Lethal  Refractory 
WB2PAP  Apr 

Take  another  look  at  those  lube  bostes  on  your 
shelf;  tho^e  ceramic  jobs  that  are  made  with 
beryllia  r=>uld  be  dynamite!  I 

Inexpensive  New  Semiconductor! 

for  the  Ham 
WA7KRE  Apr 

Descriptions  and  representative  circuits  for  « 
whole  flock  of  recently  introduced  semieon- 
ductors  from  Motorola.  Includes  dual-gate  MOS- 
FETs^  several  power  amplifiers*  thyristorSt  recti- 
fiers, etc.  Circuits  included:  VHF  amplifier,  audio 
amplifiers,  telephone  ampUfier, 

London's  Science  Museum 
Demonstration  Station 

Ellison  ^^y 

A   look  inside  the  museum  and  a  description  of 

the  amateur  radio  facilities  there.  Includes 
photos. 

Plus  Ten  dB.  .  ■ 
W20LU  M*y 

A  quick  way  to  rcJate  power  to  decibels^  and  an 
easy  method  for  calculating  one  commodity  or 
the  other  when  one  of  the  commodities  Is 
known. 

Selectivity  Has  Come   a  Long  Way 
Swan  May 

The  theory  of  bandpass  fillers  and  a  descriptiort 
of  Swan's  n&west  entry,  [ncLudes  performance 
specs. 

Science  Fairs;  Science  EducatilHlf 
Mocking  May 

A  revealing  look  at  the  schools*  approach  to 
science  education  these  days.  Good  reading  for 
those  who  care. 

Bigger  Knobs  for  Better  Performance 
WB21CV  May 

An  encapsulated  rundown  on  the  findings  of  a 
hi^h-cost  program  to  human -engineer  consoles. 
Modt-rn  j^ience  now  says  tiny  knobs  can  cramp 
your  style! 

Epoxies  for  Electronics 
W9ICXJ  May 

How  to  steal  a  trick  from  the  professionals  and 

use  modem  epoxies  lo  perform  the  bonding  that 
once  had  to  be  done  with  a  hot  soldering  u-on. 

Comments  on  FCC  Repeater  Froposal 

Staff  **■*' 

A  poi»t4iy -point  reprint  of  the  FCC*s  Docket 
1SS03.  along  with  suggested  revisaons  to  make 
the  rules  more  realistic  and  easier  to  live  with. 


Ground  Support  for  the  Powder  Puff  Derby 


W7ZC 


Jun 


The   ins  and   outs  of  providing  commumcation* 
ior  the  most  famous  ak  contest  in  the  world. 


WBSJNl 


W^KXJ 


The  Low-Noise  Antenna 

(Antennas) 

The  EffecU  of  Temperature  and 
Frequency  on  CoRAlal  Cable  Loss 

I  Antennas) 


Jon 


Jun 


Government  Surplus 

Straight  Froin  the  Hor&e's  Mouth 

WA9ANW  Jtm 

How    to  get  on  the  Government's  surplus  gravy 

traln«  How  to  buy:  how  to  bid. 

Improving  the  Performance  of  Trap-Typ« 

Vertical  Antennas 

W2EEY  Jun 

The  addition   o      (Antennae I  m  consider-^ 

The  Club  for  Blind  Amateurs 
Champagne  Aug 

Pictorial  story  of  KlTpX,  the  Perkins  Radio  Club 
for  the  Blind. 

Bam  Radio  Chess 
W1EMV/©BMW  W  Au» 

Two  schemes  for  annotating  chess  games  for 
over*  the -ait  play. 

What  Really  Happened  to  Hamdom? 

W9HBF  ^P 

The  author  asks  why  we  are  in  the  sute  we  are. 
He  advocates  QRO  and  a  good  beam  as  opposed 
to  brute  force  power,  and  poinu  to  socne 
uncomfortable  comparisons  between  ham  radio 
and  citizem  band. 


Y02B0 


YO  —  An  Interesting  DX 
CDX) 


Oct 


AC  Switchiog  with  ^eU -Powered  ICc 
W2FBW  Nov 

A  new  approach  to  pow^er  switching  of  ac 
circuits:  rii  is  eliminated,  power  supply  diodes 
are  protected,  switch  contact  wear  is  reduced « 
and  tube  heater  life  extended.  iCs  switch  at  the 
icro  current  point. 

Pioneer  Radio  on  the  Frairte 
W6CXC  ^^v 

Sentimental  remembrances  of  E,  E.  Krebsbaeh 
and    the    contributions  he  gave  to    the    field    of 

amateur  radio. 


Helpful  Hints 
Proper    Use    of    Silicon    Diodes 

1WA3ACL  J»" 

How  to  use  the  ratings  of  diodes  in  your  rectifier 
projects.  Includes  suggested  applications  for  such 
diodes* 

Simple  Compact  6m  Bandpass  FiUcr 
WA5SWD  J*'^ 

A  high-performance  TVl  for  6  meters  that  costs 
less  than  S5  to  huild.  The  filter  is  to  be  installed 
in  the  transmitter's  transmission  line. 

Using  Diodes  for  Adapting 
AC  Relays  to  DC 
WASSWD  J«*l 

Simple  shorty  article  showing  the  right  way  to 
use  diodes  for  low- voltage  rectification  where  the 
object  is  to  use  dc  relays  with  an  ac  supply. 

The  DX-aS  Revisited 

W2AOO  ^^^ 

A  trick  or  two  for  updating  Heathkit's  popular 

DX*35  Novice  rig. 

From  Breadboard  to  Printed  CirciilU 

the  Easy  Way 
KIAOB  ,     Feb 

A  simple  system  for  making  PCs  by  usmg  an 
Xacto  knife  to  cur  around  original  artwork. 

professionalP  PCs  From 
Roll-Your^wn  Negatives 

K6MVH  W"' 

A  means  for  creating  high-quality  printed  circuits 
without  the  time-consuming  and  expensive  dark- 
room processes* 

Easy  Diode  Testing 
K4JK  Mar 

A  clever  means  for  nondestructive  I  y  testmg  * 'bar- 
gain** diodes  to  leam  their  PI V. 

Super  Sizer 
WASAQS  ^" 

Many  little  modifications  that  will  cut  the  resale 
value  of  Heath^s  Sixer,  hut  which  will  surely 
make  the  rig  work  better* 


Apr 
and 


Renovating  Surplus  Meters 

WAtABI  .   ^ 

A    test    or   two,   a  dab  of   w*iiite    paiov   - 

presto! 

Keep    'Em    C^lO^    to    KFO    Cajis 

G3KFO  .     ^     ,  **f^ 

Construction  data  for  building  simple  heatstnks 
for  vacuum  tubes.  The  idea  is  to  extend  tube  life 
and  reduce  heat  dissipation  within  the  lube 
envelope^ 


W9KXJ 


Epoxies  for  Electronics 
(General  Iriforfnation) 


May 


Bigger  Knobs  for  Better  Performance 
WB21CV 

(General  Inlormation) 


May 


DECEMBER    1970 


111 


1 


Educated  tdiot  Lithlc 
Holfoitf  Mar 

Hon    to   modiFy   the  tM-t"*  "klitii  Itght^"  wanting 
ivit«m  l>y  Ada[)tfT)i  a  buxi,er  to  complein^n^  tt, 

CoaK  Adaptcf  -  VHF  to  BNC 
W9MEV  Jun 

A     "quLehlr*'     article     ihowE    how     tp    combine 
fiuines  tci  gpt  a  professiorial  Look  Ins  adapter. 

UsefuL  Cable  Clampi 

A  brask  iK<irty  tellinc  how^  to  uw  host  cSainps  to 
hold  cabLci. 

De^&r  Your  VTVM 
WA0FFi  Jun 

A  quick  and  crafi^  wav  to  clean  il  up. 

Two  Recrtven  Ijom  On*  Anlrnna 
WA6UFW  Jun 

CAnleitnai) 


WAGCrr 


MeaitETinf  RF  Output. 
(ADlennasJi 


Jun 


InaUUing  the  Swan  350C  Noi««  Stlincer 
WA6CFP  Jun 

PiftairiaL  itoTy  tells  how  to  do  it  neatly. 

A  Sotderinf  Gun  Tip 
WB€rKA  Jul 

UiinE  silver-plated  winr  for  ^otderina. 
Mount  That  Mobile  Riaht 
K4IPV  Aug 

The  rlRhi  kind  of  mobile  Initall^tior  wlfl  retult  in 
bigger  sigrub.  better  operator  safety,  and  more 
fun  m  hamming  an  Ibr  road,  ,  T 

ATVt  Getting  a  Belter  Picrtof* 
WA6BJV  Aiig 

CAntcfinaJ^ 

Converting  24V  DC  Rt^tays  to  116 V  AC 
Douglai  Sep 

Thr^e  circuits  and  a  brief  article  on  how  to 
accomplish  this  La^. 

Reed  ReUyc  for  UHF/VHF  Coaxial  Switching 
W7CRV  Sep 

How  to  us#  reed  relayi  in  plaee  of  the  expensve 
e««3i  rvLays  awi  get  better  overall  performance. 

tnctudei  frequency  loa  and  isolation  curves. 

Neater  Cabling  With  Nylon  Cotd 
WA9ABI  Oct 

Use  o(  nylon  and  he^t  to  make  it  neat. 

Irnproving  Regulation  in  High  Voltage  Suppliea 
KGBW  .  Oct 

Shoriirtg  nut  the  surge  resistors  with  a  delay 
circuit  Co  improve  perrormance  of  a  high -voltage 
regulated  power  iupply. 

Calibrate  that  Catibrator 
W2KPE  Nov 

Uung  WWV  to  calibrate  the  receive^r  100  kHz 
calibrator  more  accurately  than  it  ha*  ever  been 
calibrated  before^. 

Sotid-State  D«tt«-r  Control  for 

SSB  EKCiter« 

W4KVK  Dec 

Vernier  tuning  eliminates  dial  backlash  and  other 
tuning  anomalies,  and  gives  precision  variable- 
fre<juen.cy  cnntrol  of  operfttjng  slot, 

Two-TeTmlnal  Cuirent  LlmJter 
Beent  Dec 

Simple  series  circuit  holds  current  to  tafe  leveL 


Humor 

The  Manuicript  Game 
Staff 

Every  good  article  gets  its  due  reward. 


Jan. 


How  I  Read  the  Radio  Operator*! 

Handbook  and  Found  Happinru  ,  ,  , 
Johnson  Mar 

The  author's  fitoi-y  Of  ho%v  he  mastered  ham  radio 
theory  overnight. 

Bob-Bob- Bobbin"  Along 
K1YS0  Mar 

titter  <rhaot  and  hilarious  confusion  from  the  pen 
of  7^'5  only  in^ne  author. 


That  Contest  Craze 
VK4SS 
An  old  tiger  bares  his  fangs. 


Aug 


Code  Frartice  a  la  Baby  Tail 
W90XA  Sep 

Sometimes  there  are  advantages  to  becoming  a 
ham  that  irenH  even  listed  in  tne  manuals. 

Camouflage 
K99AZG  Oct 

How  to  buy  lots  of  ham  gear  without  letting  thf* 
old  lady  know. 

Clinks  In  a  Vacuum 
Derfler  Dec 

A  )ow-pTf*S!(ure  article  for  wives^  (Or  for  hubsands 
to  show  wives  who  don't  dig  radio ,) 

Hami  are  a  Wufutf  Bunch  of  People 
fc3KMO  Dec 

A  few  of  the  paradoicrs  that  make  it  emsr  for  us 
to  Eaugh  at  ourselves, 

T^pm.  It  Talkal 

WSFEZ  Dec 

Kool  vour  friends  with  a  newspaper  that  talk*;. 
IVs  a  homebrew  electrn static  speaker  fashioned 
from  paperK  and  foil. 


IC  Proiocts 

Frequency  Synthesis: 

The  Modem  Way  to  Control  FreqiJericy 

W2EUP  Feb 

(FM) 


Hew  Linear  ICs  for  the  Ham 
WA4KRE  Feb 

A  dowo-to-earth  description  of  Motorola**  latest 
ICs  doe  amalcurs.  along  with  schematics  lifted 
from  Motorola's  application  notes.  Includes 
Ikower  supply  and  regulator  circuits^  amplifiers, 
modulatori. 

A  Logical  Approach  to  Surplus  Buying 
K5JKX  Mar 

How  to  identify  and  te^t  ICs  commonly  found  in 
the  surplus  market.  Includes  an  extremely  literate 
discussion  of  the  principles  of  logic. 

Low  Frequency  t«F  Modules  Using  ICi 
K1CLL  Mar/ Apr 

Description  of  what  the  author  feels  is  the  ideal 
hi.  This  teat  includes  a  very  good  dis$ertaLton  of 
the  ins  and  ottts  of  such  populaj-  i-fs  as  455  kHz. 

High'PerfDrnuince  Power  Supply  Ufuig 
an  IC  Voltage  Regulator 
KdfCF  Jul 

0-20V  at  up  to  KDO  mA  in  a  iinv  package. 

An  Impedance  Multiplier  for  the  VOM 
K6DQB  Jan 

Using  an  IC  to  do  the  trick. 


Goldstein 


The  tCmitt«t 
CCW 
Three  Versatile  IV  Testers 


AtJg 


WA2IKL  Sep 

This  article  lists  pin  diagrams  for  the  common  ECs 
and  diescnbcs  simple  testers  for  checking  digital, 
linear,  and  counter  ICi^ 

Understanding  and  Using  Integrated  Circuits 
W6DNS  Oct 

All  the  baticsi  what,  they  are,  how  they're  used; 
why  they're  used. 


The  Phaae-Locked  Loop  Comes  of  Age 
K5JKX  Oct 

A  new  IC  and  how  it  can  be  used  in  some  pretty 
snphis^ticated  circuitry, 

Low-Cost  Functton  Genermtor 

for  Expertmrnters 

WAJ2EKL  Oct 

Makes  sine,  square,  and  sawtooth  with  excellent 

quality. 


tC  Marker  Generator 
K4BBC  Oct 

Simple  tC  device  gives  marker  signal  when  you 
approach  the  edge  of  your  authori^^d  band. 

Ptactical  IC  Regulator  Circuits  for  Hams 
WB2EGZ  Oct 

For  a  500  mA  supply. 

ICs  for  Amateux  Use 
KI CLL  Oct 

Describes  m  couple  of  good  rf  amplifiers  using 
inexpensive  ICs,  One  for  6  meters,  another  for 
40. 

AC  Switching  with  Self-Powered  1C« 

Nov 
(Gen,  Info^li 


WB4MYL 


Low-Cost  AtiNimfltic  Reyeri 
A  First  Project 

(CW) 


Nov 


SoUd^tate  Transceiver  for  40  Me  ten; 

the  SST'l 

W9ZTK  Nov 

A  modulari/ed  QRP  rig  with  huJit'in  twr  bridge, 
CW  monitor.  Has  ICs  in  audio  and  receiver 
lectio  OS. 

Solid-Sate  ExciUr 
W6YUY  De* 

IC'S  and  transistors  makes  this  SSB  exciter 
modern^  inexpensive,  and  efficient. 


<HR  PROJ) 
W2  FEZ 


Yipea,  It  Talks! 
(Humor^ 


D«c 


lC«y«rt 

Transceiver  Companion 
W^AJZ  jaa 

This  ii  a  complete  control  console  and  accessory 
for  the  transceiver  that  doesrk''t  already  have 
everything.  It  includes  ci»m pressor^  preamp.  elec- 
tronic keyer.  phone  patch,  speaker,  cloc^,  and 
the  kitchen  smk  all  tn  one  neat  package. 


SUff 


WB4MYL 


CW  Can  Be  Fun 

<CW) 

Low><}ost  Automatic  Keyer; 
A  First  Prole  ct 


KfiKA 


tCW) 

Uabile  CW 
{CW> 


Jun 


Nov 


Jan 


Base^Tuned  Center-Loaded  Antenna 

WaEEY  ,  Jan 

(Antennas) 

SSBh>AM*FM  Modulation  System 
W3BSP  Jan 

Tongue-ifi-rliepk  techfilcaJ  article  about  a  system 
the  author  actually  uses.  He  trails  il  ^'frequency 
aperture^'  modulation.  The  most  inleresiing  part 
of  the  article  i$  the  author 'n  clever  fid^ptiatian  of 
a  53  e^on  drum  for  use  as  a  10  meter  cavity. 


The  Camper  —  Mobile  and  Portable 
WA9EHE  Feb 

How  to  get  the  most  out  of  a  ham  station  when 
you  own  a  camper,  plenty  of  radios,  and  like  to 
travel  a  lot. 

Variable- Impedance  Mobile  Mount 
WIEMV  Feb 

(Antennas) 

7/B-WBve  Mobile  Anietuui  lor  2  meter  FM 
W2EUP  Apr 

(Antenami) 

»^«» ,  ^^  Riviera  Style 

K9BDJ  May 

The  story  of  «  Buick-owner*i  problems  and  how 
be  traced  them  down  in  order  to  eliminate 
mobile  interference. 


WliBLZ 

I        I 


A  Mobile  CW  TransmJttee 
tCW) 


May 


WA7EMM 


An  FM  ''Best  Buy" 

(FM) 
A  Ham-Si  ylc  Burglar  Alarm  for  the  CttT 


May 


K2JLD  May 

Description   of  a  scheme  for  foiling  prospective 
rig  thieves- 


Hplford 


EAO^TGV 


Educated  Idiot  Lights 

fHelpftU  HinU> 

S;a  Wavelength  Verticals 

lAntertnas) 
The  2 7 -Minute  Mobile  Limltcr 


Mmy 


Mar 


W7SOH  May 

How  to  build  an  effective  noise  Jimitpr.  As  an 
alternative,  the  author  shnws  how  to  modify  an 
existing  Bishop  type  noise  li miter*  The  modifica- 
lion  takes  27  minutes. 


wurYQ 


A  Practical  DDRR  Antenna 
CAntennai) 


Jun 


Suarter-Wave  Top^Loaded  Mobile  Antenna 
_     ZE  Jun 

(Antennas) 

Installing  the  Swan  25 OC  Noise  Silencer 
WA6CPP  Jun 

(Helpful  Hints) 


K4IPV 


Mount  That  Mobile  Right 
(Helpful  Hints) 

toV  From  12  —  The  Easy  Way 


Aug 


K3GSY  Sep 

HijLh  cur?«fft  tegulator  that  uses  two  transislur 
at^d  a  zener.  Better  approach  than  the  ^'dropping 
RSistor*'  tdea« 

Semi  auto  nu  tic  FM  Channel  Scanning 
WAfQPM  ijo^ 

(FM)  "*** 


IMoi5«  Clippers 

A  Noise  Blanker  That  Works 
WflRHR  Apr 

it  DOES  work,  but  the  article  somehow  got  into 
print  utithouit  being  edited,  yind  there  ^v^  Kome 
errors.  Those  who  want  let  build  should  drop  a 
card  to  editor  of  73  to  get  straightened  out  on 
discrepancies. 


WTSOH 


The  27-mlnute  Mobile  Limiter 
(Mobile) 


Mar 


Installing  the  Swan  25C1C  Noise  Silence^ 

WA6CPP  „,    .    .    ,  ,.,        .  Jun 

(Helpful  Hints) 

Nova  I  Ham  Radio  Proiects 

CDnvertind  the  4CX1000  into  a  Lamp 
K3QKO  Jan 

A  clever  lamp  for  the  hatii*t  ham.  Even  has  a 
switch  fashioned  from  a  coaxial  connector.  Bet- 
ter not  to  use  a  new  tube  f<rtr  the  lamp,  though;  it 
will  have  somewhat  of  Mti  impact  on  the  total 
cost  of  the  project. 


WGAJS^ 


Transeeiver  Companion 

(Keyers) 

The  l>ip  Light 


Jan 


VE3ECU  Mar 

A  grid -dip  ppr  that  uses  lamp  int'^nsity  tnsLt«ad  of 
a  m^eter. 

Add  Spotting  to  your  VFO 
KRBYO  Mar 

Cuti^  and  simple  technique  thut  lets  you  hear  the 
vfo  without  transtnitting. 

He  verse-Current  Charginc 
K8YUC  Mar 

With  an  almost  foolishly  simple  technique  you 
i^^n  successfully  recharge  ordinary  drv^  cells,  and 
make  them  hold  the  charge  again  and  agaid. 

Single-Side  hand  on  the  All-Wave  Radio 
W7CSD  Apr 

A  miniature  tunable  oscillator  provider  an  Ideal 
s<»urce  for  h  bt'al.-frequcnrv  ^^igna],  and  Allows 
you  to  hear  code  and  SSB  on  any  self.*ctive 
receiver  without  making  modifications  to  your 
store -bought  eiM^^ 


W6JTT 


A  Low^Band  Police  Monitor 
(FM) 


May 


112 


73  MAGAZtNE 


A  Ham* Style  BiusUr  AUrm  fox  the  Car 
K2JLD 

(Mobile} 


Holford 

Hfvw 


Educated  tdiot  Litfhti 
(Helpful  HLntfi) 


Mmr 

May 


Thi  Consummate  Console 
WB2FBF  Aug 

Increasine  station  efficiency  and  enjoy m.^ril  with 
«  broadcaM-$tyle  console.  J n elude ^s  plans  and 
construe Uon  data. 


K4B6C 


IC  Mȣkrr  Generatotr 
(IC  Proiecuj 


Oct 


Solid -Statf  lO-Minutc  Timef 
WB4MYL  Oct 

FlAns,  layout^  and  PC  pattern  for  a  M05FET 
tkmer  for  vanous  station  functions  or  repeater 
applicationjl. 

Power  Supplies 

Simple  Bench  f  ower  Supply 
2L2AMJ  Jan 

PfOvide^*  foKir  output  voltages*  three  current- 
overload  Limits.  The  techniques  described  can  be 
applied  to  other  power  supplies. 

Pfopez  Use  of  SiUcoo  DiiKies 
WA3ACL  Jul 

How  to  use  the  rating  of  diodes  in  your  rectifier 

Srojects^  Includes  sugsesied  a ppli coitions  for  such 
lodes. 

A  IQmiCB  Fireamp 
WA3IIMW  Jan 

Using  $.  smrpki^  10m  preamp  with  a  slight  amount 
of  conversion*  Details  Include  power  supply 
Instructions^ 

Usinf  Diodes  for  A  dating 
AC  Relays  to  DC 
WASSWD  Jhtp 

Simple  shorty  article  showing  the  right  way  to 
tiM  diodes  for  low-valtage  rectificauun  where  the 
object  is  to  use  dc  relays  with  an  ac  supply^. 


WA4KRE 


New  Linear  ICs  for  the  Haia 


(IC  Projects) 


Feb 


Tuiming  the  AN/GRC-S  Into  a  Kovtee  Rig 
W6JTT  Mar 

(CWJ 

A  Simple  Bias  ReEEUlator  tot  Linear  Ampll/iers 
ZL2ANG  Apr 

Shunt  ro£ul«tic»n  for  bias  supplies  nffers  the 
ad^'antage  of  low  constant  current  drain,  and  it 
can  be  u5e^i  wfih  the  netleete^  —  till  now  —  class 
B  and  AB2  linear:^ 

Va<;ttyiB-Tub«  Load  Box 
Aalie  Apr 

Schema tic«>  photos^  and  coo^truction  details  for 
a  power  supply  test  set  .  .  , 

Power  Supplies  From  Surplus  Components 
WB6BIH  May 

Lots  of  theory  and  a  few  schematics  for  con- 
verting old  surplus  Junk  into  something  usiefuL  If 
you're  a  muthematiclan,  this  is  certAlnty  your 
bag. 


K<PECF 


MJjth-Performance  Power  Supply 
Umtng,  an  iC  Voita#e  Regulator 

etc  Projects)  kkfcc. 

More  Notes  oik  Diode  Stadu 


Ju! 


W2BDG  Sep 

A  description  of  GE*s  high-power  (5  kV  aL  300 
mA}  rectifier  modules. 


K3GSY 


6V  From  12  —  The  Easy  Way 
(Mobile) 


Sep 


Simple  Regulated  Power  Source  for  ICi 
WIRAN  Oct 

Regulated  power  supply  uilng  series  diodes  (not 
xeners)  to  give  precise  vMu«t  of  required  voltages. 

Practical  t€  Regulator  Circuits  for  Hams 
WB2EGZ  Oct 

(IC  Projects) 

improiring  Regulation  in  High  Voltage  Supplies 
KSBW  0«^* 

(Helpful  Hints) 

Differential  J^FET  Preamplifier 

W4RAE 

Design,  construction  data,  arid  performance 
curves  for  a  low- noise  preamp  using  an  tti^A 
CA^3028  J-FET.  Includei  separate  power  suppJy 
circuit. 

Vour  Second  Linear 

H^b^wer     linear     amplifier    "S^ihSmftfc^f^r 

vacui^  tube  for  the  fin*!.  Includes  schematic  lor 

a  kilowatt  power  aupplF. 


QRP" 

''Quasar*'  QRP  40m  DSB  Tranfimitter 
WA5WWN  Jan 

Good  low-power  rig  for  nid^'bnnd  or  CW;  u.ms  4 
transistors  and  an  audio  umplirjer  module. 

Postage  Stamp  Transnattter  for  Sise 
KICLL  Mar 

Complete  plans  —  including  part  list,  layout, 
srhem^atic.  and  construction  details  for  a  irans- 
miuer  thai  is  an  eighth  of  an  mch  thick  and  oniy 
'3/4  in,  square.  This  one  really  works,  to-o. 


QRP 
WA3JBN  Jun 

Two  sample  rtgi  for  CW  operafJoD  on  40  meters. 


Goldstein 


The  iCmttter 

(CW) 


VHF  AM  Transmitter  Using 
Low -Co  St  TranMftors, 
Btubakcr 
If  it'll  work  on  AM  it  11  work  on  FM. 


Aug 


Aug 


KICLL 


Oct 


ICs  for  Amateur  Use 
(IC  Project*) 

2W  S  Meter  Transmitter 
Using  the  Beterodrne  VFO 
KICLL  Nor 

Breadboard  design,  tuneup,  and  performafice  of 
itn  rf  power  stage  on  6m  using  a  So  trmnfistof  and 
a  stable  vfo  circuit. 

Solid-State  Transceiver  for  40  Meters: 

the  SST-1 

W9ZTK:  Nov 

(IC  Projects) 

^-Meter  MinilraiisiiiJtter  for  Repeater  Use 
WB6BIH  Dec 

<FM) 


Receivers 

Solid-state  Double*Band width  Tunabk 
l-F  Converters 
KICLL  Jan 

A  good  tunable  converter  can  get  you  any 
frequency  or  band  in  the  VHP  rai^ge  you  want. 
This  article  tells  how,  and  it  includes  schematics, 
parts  lists,  afid  completi  instructions. 

A  lOm/CBPreamp 
WA3HMW  Jan 

Using  a  surplus  lOm  preamp  with  a  slight  amount 
of  conversion.  Details  include  power  supply 
iiutructions, 

A  Simple  IC  Q^M uH jplier 
W2EEY  Feb 

l/sing  an  IC  opamp  for  a  Q-multipiier,  Ad  vantages 
include  simpiicily,  broad  r^nsn'  of  operjitiaii„  xind 
variable  Q  and  peaking  frequency. 

High-Performance  Con%'erter  for  6 
WABHES  Feb 

Tube-type  converter  uses  a  Nuvistor.  This  article 
may  become  valuable  as  the  last  tube  converter 
circuit  ever  published. 

Low  Frequency  I-F  Ifodutes  Using  ICs 
KICLL  MariTApdr 

CIC  Projects) 

High  Performance  i-F  Amplilier 
„.  ^  "nd  AGC  System 

Zt2BDB  Apr 

For  C.  W  or  SSB  work,  you'll  find  this  system  hard 
tti  beat  with  its  fast-attack,  slow-decuy  char- 
acteristics. A  wide  blilud^"  of  slug e  ijain  is  dsiured 
with  both  forward-and  reversei-acting  age  ele- 
ments^ 

Hot  Carrier  Diode  Mixer  Converter  for  2  Meters 
WA6NCT  Apr 

Low  noise,  high  gain,  eKceltent  overload  reMst- 
ance,  and  a  very  high  degree  of  isolation  combine 
to  make  the  hot  carrier  dMnJe  particularly  attrac- 
tive for  applicatiuns  in  receivers  and  converters 
This  tut^cie  has  good  PC  layouts,  photos,  schema- 
tic^. 


WA4WDK 


FET  Fteamp»  lor  VHF 

(FM) 


May 


I-F  Filter,  Converter,  AVC  "Ideal" 
_,„,  Circuits 

KICLL  May 

The  second  half  of  Hoisington's  two-arttclo  series 
on  the  ideal  i*!'.  This  one  m  eludes  bread  boarding 
the  complete  l-f  syst^^m. 


450  MHz  Mighty  Mite 


A    superregenerative   receiver   for   432  MHz,   tn* 


K9VXL 
A  supei 
dudes  PC  layout. 

Mobile  CW  Receiver 

CCW) 


Jul 


WGBLZ 

c 


Jttl 


Dclune  Receiver  Gain  Control 
VU2JN  Sep 

Improving  age  'jpformanee  In  tube-type  receivers 
with  the  addition  of  a  triinfiislor  control  circuit. 
Intludes.  charl  showing  tracking  cur^^e. 

A  Versatile  and  Stable  MOSFFT 

CriDverter  for  144  MHz 

WBCYVT  Sep 

A  low -noise,  high  performance  converter  with 
eiccellent  gain. 

The  Phase'^'Locked  Loop  Comes  of  Aie 
K&JKZ  Oct 

(IC  Projects) 


W4KAE 


Differential  J -FET  Preamplifier 
(priwer  Supplies  1 


Nov 


RF  Applications  of  the  Dual-Gate  MOSFET 
Sir  Hon 

Application  suggestions  from  Ihe  engineering 
desk  at  Fairchild  Semiconductors.  Includes  re- 
ceiver circuits  and  amplifiers  for  VHF. 


W6TEE 


Feb 


Repeaters 
Setting  Up  the  Tone- Burst  Sy lEtem 

Tone  Decoder  for  Remote  Switching  Applications 
K6MVH  Feb 

(FM) 


Encoders  for  Sub  audible.  Totie-Buirst 

or  Whistle-On  Use 


Feb 


A  Look  at  Amateur  FM  Standards 
WB6DJT  Mar 

(FMl 
A  Work  Session  on  the  Wichita  Repeater 

WC^D  K  U  ^  P^ 

Nobody  knows  any  better  than  the  tepeater 
owner  just  how  religiously  Murphy "S  law*  are 
followed  by  Nature  ,,  .  . 

FM  Repeaters  Under  Fire  From  FCC 

Stafr  Apt 

The  first  published  notice  of  FCC's  infamous 
Docket  18803,  Sketchy  but  essentially  accurate* 

Examining  FM  Repeater  Operation 
WBBDJT  Apr 

<FM) 

Understanding  the  G*rrier*Operat«d  Repeater 
K6MVH  Apr 

(FMJ 

Directory  of  American  Open  Repeaters 
Staff  Apr 

(FM) 


WA4YND 


WB2AEB 


W9DKtr 


A  Repeater  Controller 
CFM) 
A  Word  About  Repeaters 


Apr 


Apr 
<FM|  iioofc... 


The  Wichita  Autopatdh 


St^ff 


KIZJH 


CFM) 

73  Commentjc  on  FCC  Repeater  Proposal 

(General  Information) 

(General  Information) 

The  Intelligent  Use  of  2  Meiers  FM 

<FM) 


May 


May 


May 


A  Two^hannel  Search'Lodt  for  FM  Receivers 
W:iDTN  Jul 

(FM) 


K6MVH 


Super  Autopateh 
CFM) 


Jtil 


Repeater  Audio:  Time  Out  for  Quality 
KfSMVH  Aug 

(FM) 

Optimizing  Antenna  Separation  in  FM  Repeaters 
K6MVH  Sep 

(FM) 

Integrated  Circuit  CW  ID  Generator 
WTFUG  Sep 

CCW) 

Controlling  Repeaters  with  Tones 
K6MVH  Oct 

(FM) 


WB4MYL 


SoUd-State  10«Minute  Timer 


(Novel  HR  Projects) 
2 -Meter  Mini  transmitter  for  Repeater  Use 

(FM) 


Oct 


WB6BLH 


Dee 


Staff 


Reviews 
Kris  Scanning  Receiver 

(FM) 


Mar 


Evaluation;  Standard  2m  FM  Transceiver 
WeOGN  Apr 

(FM) 

The  GmiMlift  "Satellite '"Receiver 
Staff  Jun 

An    evaluation    of    a    portable    receive    th^l    has 
every  th  in  g«  in  cludirkg  stable  SSB, 


Suff 


K9STH 


CW  Can  Be  Fun 

Allied  Porta:ble  FM  Receiver 
(FM) 


JUB 


Jul 


The  Knight'Kit  RF  Generator 
W9KXJ  Aug 

An  evaluation  of  the  KG-694i  signal  generator, 

DyComm'^s  15W  2  Me(«r  Mini- Amplifier 
Staff  Sep 

(CW) 

Regency  —  an  FM  Late ^S tarter 
Staff  Dec 

(FM) 


i  I 


I 


DECEMBER    1970 


113 


SSB 

Single^idebajid  on  the  Atl-Wav«  Radio    ^ 
W7CSO  Apr 

(Novel  HH  ProKcts> 

A  New  Approach  to  Communications  Eqiilpfnent 
K9ALD  Sep 

The  author  describes  ft  modular  concept  for 
■tandardizing  of  SSB  triLnsceiver  desifin.  The 
object  U  to  improve  oerforrrtance  of  each  module 
itk  an  SSB  system,  while  affording  hams  the  op- 
portunity of  building  or  repairing  their  own^ 


W4AY1 


WSYTTY 


W4NVK 


Touf  Second  Lineai: 

{Power  Supplies) 

Solid-state  Exciter 

([€  Projects} 

Solid-State  Driia-F  Control  for 
SSB  ExcUezs 

CHcJpful  Hints) 


Dec 


Dec 


Dec 


WAaHMW 


Surplus 

A  lOm/CB  Preamp 

CPower  Supplies) 


Jan 


UdDf  Diode  I  for  Adaptinc  AC  Relays  to  DC 
WA5SWD 


Jan 


(Power  Supplies) 


Fac^mlte  «nd  Ihe  Radio  Amateuf 
K€GKX  Jul 

More  on  adapting  surplus  equipment  to  hftm 
FAX  service;  m eludes  photos  of  equipment, 
block  diafiams^  and  a  cha^i  showitt^  tr^msmission 
frequenciea  and  times  for  various  stationj. 


W^KXJ 


The  ICnifht-Klt  RF  Generatof 
CPtoducl  Reviews} 


Aug 


An  Impcdanee  Multiplier  foi  the  VOM 
KDEQ  Jan 

(IC  Projects) 

File  Box  Retittance  Decade 
WB4ITN  Sep 

The  firit  in  a  series  of  "fUe  box"  Articles.  Here 
the  author  ma^eis  a  precbion  decade  box  and 
inctudec  ic  he  ma  tics  for  v^rLations  of  his  own 
de$ifn. 

The  Indicatlni  OsciUaloT 
RH6AF  Sep 

\  gnd^pptit  without  fridi.  Uses  FETs.  Includes 
A  Circuit  for  amplifying  microajnpi  to  miUiamps, 
which  should  be  bandy  fot  other  projects  as  well. 
But  be  caj-elul.  Fie  J  ii  Imbeled  2  and  vice  vena. 


WA21KL 


Three  Versatile  IV  Testcti 

(EC  Projects) 


Sep 


Low-Cofi  Osicillator  &  Infinite  Attenuator 

for  Tuning  VHF  Receiver* 

KICLL  Sep 

(FM) 

A  Low-Cost  RF  Wattmetci 
WAaAJR  .  Nov 

Inexpensive  means  of  using  an  ordinary  meter 
and  i  conversion  chart  lo  accurately  gage  power 
output  from  4  to  4O0O  Walts. 


W2KPE 


Calibrate  that  CalibratoT 
(Helpful  Hints) 

The  Tmnd-Tesi 


Nov 


WB6QQP  Dec 

Useful  but  simple  device  can  measure  traniiistor 
beta^  leakage^  and  shorts. 

The  Little  Gate  Dipper 
W5ETT  Dec 

Anotber  grid -dip  per  with  no  grid:  eoveri  1.7  to 
ZZb  MH£«  yet  is  cneap  and  quick. 


Turning  the  AN/GRC-d  Into  ■  Novice  Rie 
W6JTT  *Mar 

(CW) 

A  Logical  Approach  to  Surplus  Buying 
K5JKX  Afar 

(IC  Projects} 


W6YAN 


A  Poor  Man's  Freauency  Meter 
(FM) 


Mu 


Convertirti  the  Sonobuoy  lo  a  3W  FM  Tranimitter 
WIBYX  Mar 

tFM) 

_„  An  Inejcpeniive  RF  Wattnjeter 

WB41fYL  Mar 

Simple  adaptation   of  a   piece  of  surplus  equip- 
mentc 

Power  Supplies  From  Surplus  Components- 
WB6BIH  May 

(Power  Suppties) 

Government  Surplus 
Straight  from  the  Horse's  Mouth 
WA9AKW  Jun 

(General  InformAtton) 


Converting  24V  DC  Relays  to  115V  AC 

Douglai  Sep 

(Helpful  HinUI 

Test  Eiiulpment 


Equipment 
Panoramic  Rewlver  for  VHF 
IISLO 


Feb 


A  spectrum  analyzer  of  tons.  Let's  you  see  on  a 
CRT  the  whole  2  meter  band  at  once, 

Frec|ueney  Syntbens: 

The  Modem  Way  to  Control  Frcqtwney 

WZ%UW  Feb 

(FM) 


Extra  Services  from  Your  Grid  Dip  OscilUtor 
WA4UZM  Mar 

A  pltig'in  jidiipter  turtle  a  grid-dipper  into  ii  good 
crystal  eaijbrutur. 


WB4MYL 


An  tneacpenffive  RF  Wattmeter 


Mar 


W6YAN 


A  she 


(Surplus) 
A  Poor  Manx's  Frequency  Meter 

(FM) 

Vacuum-Tube  Load  Box 

(Power  Supplies} 


Apr 


How  to  Megger  Your  Antenna 

W2EEY  Apr 

(Antennui) 

FM-AM  Truumitter-Receiver  Aligner 
W3JKL  May 

(FM) 

Measuring  the  Difference  Beiwteti 

Incident  and  Reflected  Power 

VE7BS  Jim 

(Antennas) 


W2EEY 


WA6CPP 


Remote  SWR  Indicator 

(Antennas) 
Measuring  RF  Output 
(Aniennai) 
Amateur  Wattmeter  for  S3.85 


Jun 


Jun 


KICLL  Aug 

Tells  you  your  power  output  from  about  10  mVV 
to  5W.  over  the  f^n^^e  from  160  meters  thcough 
450  MHz.  Principle  is  based  on  cotnpanson  of  an 
rf  activated  lamp  with  another  of  same  bnlli^ce 
whose  power  input  is  known. 


TrBfism  (tiers 

''QuaiEftr"  QEF  40m  D SB  Transmitter 
WA5WWN  Jaa 

(QRP) 

Postage  Stamp  Transmitter  for  Six 
KICLL  Mmt 

(QRP) 

VFO  Circuit 
K0HVK  Jun 

Tube-iype  for  BO  and  40  meters.  Em%y  to  build. 


WA3JBH 


QRP 

CCW) 

Cheapie  6-Meter  Half  Gallon 


Jun 


KICLL  Jul 

It  works  out  to  $12.&0  a  quart,  and  features 
low-cost  tubes,  no  screen  voltage,  no  bias  require- 
ment e,  and  no  btower^ 


Goldstein 


The  ICmitter 
(CW) 


Aug 


VHF  AM  Transmitter  tiling  Low'Cost^  Tnosistors, 
Brubaker  Aug^ 

tQRF) 


KICLL 


ICs  for  Amateur  Use 
(IC  Projects) 


Oct 


Solid -State  Transceiver  for  40  Meters^ 
the  SST-1 

W9ZTK  Nov 

(IC  Projects) 


W6YUY 


W4AY1 


So  lid -SI  ate  Exciter 
(IC  Prof  ecu) 

Your  Second  Linear 
(Power  Supplies) 


Il«c 


TV 

Slow-Scan  Color  TV 
W4UMF  Jftn 

The  principles  of  color  separalion.  as  applied  to 
slow-scan  tele  vision  $>-tlemf.  Includes  tpectral 
charts^  photos  of  ofl^the^air  pix. 


Bfbliofrmpbr  t»f  SSTV 
W4UMF 

Complete  directory  of  «rtie:les. 


Jul 


Improved  Color  TransntlHian  — SlowScan  TV 
W4UMF  Jul 

Applying  ihe  principles  of  color  separation  and 
synthesis. 


WA6BJV 


ATV:  Getting  a  Better  Picture 

(Antennas) 

Amateur  TV  is  Easy 


Aug 


IC20JL  [>ec 

It  actually  costs  no  more  than  flOO  to  get  starteil 
In  the  fun  hobby  of  amateur  T v. 


ctnir> 

K20JL 


K9VXL 


Amateur  TV  b  Easy 

(TV) 

UHF 
4EiOMiIz  Mighty  Mite 
(Receivers) 


Dec 


Jul 


Log  Periodic  Antenna  De^siu  for  VHF/ UHF 
W3DUQ  ^^ 


WA6BJV 


(Antennas) 

ATV;  Getting  a  Better  Picture 

(Antennas) 


Atig 


Aug 


Reed  Relayi  for  UHF/VHF  Coaxial  Switching 
W^vtiRY  Sep 

(Helpful  HinU) 

VHF 

SiQlid^State  Double- Band widfli  Tunable  l-F 

„, Conre  rtcn 

KICLL  Jan 

(Eecciv.    ) 


IISLO 


TuMkfUnle  Receivt*  forVHF 
(Te«t  Equipme  tl) 


Feb 


High  •^Performance  Con^  ^rter  for  B 
WASHES  Feb 

(Receiver!) 

Super-Sixer 
WAaAQS  Mar 

Many  little  modifications  that  win  cut  the  resale 
value  of  Heath's  Sixer,  but  which  will  *ur*ly 
make  the  rig  work  better. 

Inexpensive  New  Semiconductors  for  the  Ram 

WATECRE  Apr 

(General  Information) 

7/B*Wave  Mobile  Antenna  for  2  Meter  FM 

W2EUP  Aps 

(Antennas) 

Postage  Stamp  TranimJtler  for  Six 
KJCLL  May 

(QRP} 


ZL4TAH 


The  Sly  Beam 
{Antennas) 


Jun 


Ele¥en*Element  2  meter  Circular  Quad 

W4KAE  Jtin 

(Antennas) 


KICLL 


Cheapie  S-Meter  Half  Gallon 

(Transmitters) 


Jul 


VHF  AM  Transmitter  Using 

Low-Cost  Tranilittors. 

Bru  baker  Aum 

(QRP) 
Log  Periodic  Antenna  Design 
for  VHF/UHF 
W3PUQ  AtlC 

(Antennas) 

Low-Cost  Oscillator  gt  Infinite  Attenuator 

for  Tuning  VHF  Receiver* 

KICLL  Sep 

(FM) 

Brew  1  on  2  — a  2  Meter  Coaxial  Antenna 
WA0EWQ  Sep 

(Antennas) 

DyComm's  15W  2  Meter  Mlni-AmpUfler 
Staff  Sep 

(CW) 

Differantiftl  J -PET  PreampEfieir 
W4KAE  Nov 

(Power  Supplies) 

2W  6  Meter  Transmitter  Using  the 

Heterodyne  VFO 

KICLL  Nov 

IQEP) 

Semiautomatic  F^  Channel  Scanning 
WAOQPM  Nov 

(FM) 

RF  Appllcitlons  ol  the  Dual^Gste  MOSFET 
Sir  Nov 

(Receivers) 

20Meter  Mini  transmitter  for  Repeater  Use 
WB6BIH  Dec 

(FM) 


114 


73  MAGAZINE 


Statement  of  Ownership^  Management 

&  Circulation 

Date  of  filing:  October  9,  1970.  Title  of  publica- 
tion: 73  Magazine.  Frequency  of  issue:  monthly^ 
Location  of  publisher:  Peterborough,  NM, 
0345S,  Publisher:  Wayne  Green,  Peterborough^ 
NM*  Editor:  same*  Managing  editor:  Ken  Ses- 
sions, Owner:  73  inc.^  Peterborough,  N^H.  Bond- 
holder: Wayne  Green,  Peterborough,  N.H,  Bond- 
holders, mortagees,  other  security  holders  owning 
or  holding  1%  or  more  of  bonds,  mortages  or 
other  securities:  none.  Extent  and  nature  of 
circulation:  Average  number  of  copies  each  issue 
during  preceding  12  months:  total  number  of 
copies  printed  72868,  total  paid  circulation  (mail 
subscriptions)  72251,  free  distribution  127^  total 
distribution  72378,  of  (ice  use  490,  total  72868, 
Actual  number  of  copies  single  issue  nearest  to 
filing  date:  total  copies  printed  74285,  total  paid 
circulation  (mail  subscriptions)  73649^  free  distri- 
bution  132,  total  distribution  73781,  office  use 
504,  total  74285. 


Over  250 
of  USED  EQUIPMENT  on  SALE 

Be  sure  to  check  this  list— over  $20,000  worth 
of  good  used  Receivers,  Transmitters  and  Trans- 
ceivers offered  at  these  reduced  prices!  While 
the  stock  lasts  —  let  us  serve  you? 

We  have  Signal  One  CX7's 

in  stock  ready  to  ship 

Sandy  Jackson  mgr  —  T.T.Freck  W4WL 

FRECK  RADIO  &  SUPPLY  COMPANY 
38  BILTMORE  AVENUE 
ASMEVILLE,  NORTH  CAROLINA  28801 


B^E 


IC  Troubleshooting: 
A  Matter  of  Temperature? 


any  hours  can  be  wasted  trouble- 
shooting IC  equipment  if  you  over- 
look  one  important  characteristic.  The 
popular  Fairchild  epoxy  case  ICs  and  the 
Motorola  MC  700  series  and  HEP  (dual 
in-line  package)  series  are  designed  to 
operate  between  the  temperature  extremes 
of  +59''F  to  +131°F  (Fairchild)  or  +167^F 
(Motorola). 

If  your  shack  is  in  the  garage  like  mine 
or  at  least  unheated,  you  may  very  well  be 
operating  these  ICs  below  their  design 
temperature  range  during  the  winter 
months.  Therefore,  if  your  keyer,  counter, 
or  whatever  seems  to  be  operating  errati- 
cally or  not  at  all,  take  it  into  the  house 
and  give  it  six  or  more  hours  to  attain 
room  temperature.  Then  see  if  your 
trouble  is  still  there.  You  may  save  yourself 
alot  of  time  and  frustration.  (You  may  also 
have  to  buy  a  heater  for  your  shack.) 

Rich  McMahon  WA6IGU  ■ 


advised  by  my  lawvers  that 
ou  goons  don't  ever  orooir 

n 

ev 
ov 


I  Insist  that  you  print 
should  be  boiled  in  oil 


Bottomless 

I  would  like  to  take  advantage  of  your  most 
gracious  inoney  saving  special  3-yeai  subscription 
to  73,  I  still  have  a  card  you  gave  me  at  a 
Hamfest  last  year  so  1  could  get  3  years  for  S10» 
but  I  suppose  it*s  too  late  to  use  it  now.  73  is  still 
the  best  ham  magazine  on  the  market,  and  I  am 
tired  of  having  to  run  down  to  the  dirty  book 
store  on  Broadway  in  San  Francisco's  "Topless- 
Bottomless''  North  Beach  night  club  strip.  You 
would  be  surprised,  though,  how  many  hams 
from  all  over  I  have  met  standing  in  that  dirty 
booic  store  reading  73. 

So    please    accept    my    check    for   a    3-year 

subscription  to  73,  and  come  on  out  to  California 
again  when  you  can,  and  maybe  you  can  stop  in 
and  meet  some  hams.  They're  always  in  the  dirty 
book  store  reading  73, 

Larry  Johnson  K7VZH 

2051  Fremont  Street 

Klamath  FaUs  OR  97^01 


Jordan 

After  attending  the  ARRL  convention,  and 
sitting  in  on  several  of  your  meetings,  1  felt  that  I 
should  write  you.  First  of  all,  may  I  honestly  say 
that  1  found  the  most  interesting  part  of  tiie 
entire  convention  to  be  located  in  the  73  room 
on  the  4th  floor.  In  particular,  1  was  fascinated 
with  the  slides  of  King  Hussein  and  Jordan,  and 
the  slides  of  Y02BO,  whom  I  talked  with  at 
Y02KAC  in  the  late  195 Ox.  As  one  of  those  who 
spoke  with  you  when  you  operated  JYl  in 
Jordan,  I  sent  my  QSL  card  to  Box  1055  in 
Amman  and  received  a  beautiful  QSL  card 
personally  signed  by  the  king. 

I  then  decided  to  write  again  and  request  an 
autographed  photograph  of  His  Majesty  suitable 
for  framing.  In  the  letter  I  told  the  king  that  I 
was  a  Social  Studies  teacher  and  that  I  would 
surely  appreciate  an  autographed  photograph 
that  I  could  not  only  use  for  educative  purposes, 
but  also  could  frame  for  display  purposes  in  my 
radio  room,  I  really  never  expected  an  answer 
from  such  a  busy  and  important  person.  About  a 


DECEMBER    1970 


115 


1 


New! 


Shown  above: 
Model  3,  for 

10/15/20  meters. 

Terminals:  SO-239 

$29.95  ppd. 


MULTI-ANTENNA  COUPLER 

Eliminates  Antenna  Switching 

Chang©  bands  without  having  to  switch  antennas! 

Combme   your    antennas    into    a   multi  band    antenna    system    while   retaining  optimum 

antenna  performance  on  each  band! 
Coupler    feeds    any    combination    o^    antennas   from    a   single   transmission    linet    Saves 

operaiing  timel  Saves  coax  and  switches* 
Coypter  isolates  the  Itne  fronn  all  antennas  but  the  one  in  usef 
Works  with  all  types  of  antennas?  Handles  full  legal  power! 
Models  available  for  any  bands^  2  to  160  meters!  Weatherproof  I 


POST  OFFICE  BOX  468.  OCEAN   BLUFF,  MASSACHUSETTS  02065 


month  later,  however,  the  postman  brought  a 
large  white  envelope  with  ten  stamps  on  iL  On 
the  back  of  the  white  envelope  was  a  large  gold 
crown. 

Upon  opening  the  letter  I  was  amazed  to  find 
another  QSL  card  signed  by  the  king  along  with  a 
personally   autographed   photograph  dated  July 


k  A 


#..  -_ . 


.•Sa  .w  ^M  >Cj 


25,  1970.  Both  the  date  and  the  signature  were 
obviously  in  tiie  king's  own  handwriting.  1  have 
framed  the  card,  picture,  and  stamp  section  of 
the  envelope  and  am  enclosing  a  picture  of  it 
with  thiji  letter. 

Vernon  G.  Dameron,  Jr.  KIDRN 

265  Davis  Road 
Bedford  MA  01730 


You  have  no  doubt  kept  up  with  the  situation 
in  Jordan  in  the  iast  few  weeks.  According  to  the 

reports  I  have  heard  tlie  situation  is  bad, 
especially  in  regards  to  medical  help,  food  sup- 
plies, and  so  forth.  Perhaps  someone  else  has 
already  made  this  suggestion  but  I  was  thinking  it 
might  be  helpful  if  we  hams  banded  together  and 
ail  pooled  our  contributions  for  some  help  to  the 
people  in  Jordan.  I  don't  know  who,  if  anyone, 
could  organize  such  a  program  within  the  ham 
population  but  1  would  help  if  such  a  program  is 
feasible. 


The  king  was  very  friendly  while  you  were 
there  and  it  would  be  very  generous  on  the  part 
of  the  hams  of  the  U.  S.  if  we  could  help  him  in 
his  time  of  need.  I  would  appreciate  yojar 
comments  on  this.  Keep  up  the  good  work 
in  73.  I  am  now  a  lifetime  subscriber  and  am 
happy  to  be  one. 

Richard  J.  Malby  GS9E 

537-^44-0619 

579th  Ordinance  Co. 

APO  New  York,  N.  Y.  09035 


Cairtotiflage 

I  just  finished  reading  K9AZG*s  article 
CAMOUFLAGE,  73,  October  1970,  and  I  think  I 
can  help  him  out.  He  was  in  a  similar  position 
to  mine,  trying  to  get  a  50  ft  mast  and  tri- 
bander  up  without  letting  the  XYL  know* 
I  solved  the  problem  by  covering  the  top 
section  of  the  mast  with  brown  paper,  adding"  a 
few  branches  or  so  on  it,  and  ''planted"  it  Every 
few  months  or  so  I  added  a  section  to  the  bqttonj 
to  make  it  *'grow/'  The  tribander  was  painted 
green  and  covered  with  leaves.  Next  [  ''pruned'* 
the  lower  branches  off,  leaving  only  the  beam. 
The  brown  paper  eventually  falls  of,  and  if  the 
XYL  is  at  ail  near-sighted,  the  system  is  almost 
foolproof* 

Bin  Ames  WA9WBJ 

1909  Karlin  Dr. 

St.  Louis  MO  63131 


WAAS 

Do  you  still  issue  the  WAAS  certificate?  If  so, 
will  you  please  forw^ard  the  necessary  forms  so 
that  1  may  make  application  in  the  name  of  the 
club  w^ho  sponsored  and  operated  K6SB  for  the 
San  Diego  200th  bicentennial  celebration.  K6SD 
operated  from  October  1968  until  October  1969 
contacting  as  many  hams  as  possible  while 
celebrating  San  Diego's  200th  birthday.  During 
that  year  we  were  able  to  contact  every  state  in 
the  union,  including  Alaska  and  Hawaii,  except 
Delaware. 

So  you  can  see  K6SD  does  trulv  qualifv  for 

"Worked  Almost  All  States." 

Robert  R*  Smith  VVB60DR 
President  El  Cajon  ABC 

Yup,  still  available.  Send  49  cards  and  $1,00  to 
cover  costs  of  mailing^  etc*  * .  .  Wayne 


116 


73  MAGAZINE 


FM  Coverage 

I  am  involved  with  two  repeater  groups  here  in 
the  Denver  area,  and  am  in  charge  of  a  project  to 
set  up  a  new  repeater  for  the  Colorado  Civil  Air 
Patrol  west  of  Denver.  Colo,  Thank  you  for  the 
excellent  coverage  your  magazine  has  given 
during  1970  to  FM  repeater  activities  and  tech- 
niques. 

CUff  Flatiarty  WA*  CKS 

Box  1007 
Littleton  CO  SOI  20 


Inflation  In  a  Nutshell 

Popular  opinion  seems  to  be  that  the  FCC  fee 
hike  is  an  inflationary  move.  Well  let's  get  things 
straightened  out  The  fee  hike  happens  to  be  a 
noninflationary  move.  By  making  amateurs  pay 
more  for  their  licenses  this  will  take  money  out 
of  circulation  giving  hams  less  to  spend. 

The  whole  thing  that  starts  inflation  rolling  in 
the  first  place  is  the  fact  that  people  have  too 
much  money  to  spend.  This  action  of  spending 
puts  more  money  into  the  hands  of  the  business 
man.  When  he  gets  more  money,  his  workers 
want  more  money.  When  the  workers  get  more 
money  this  cuts  down  on  the  profit  margin  of  the 
business  man.  Seeing  that  he  is  making  less 
money  the  business  man  will  raise  prices  to  equal 
what  he  was  making  before.  And  the  cycle  goes 

on  and  on.  Joseph  F.  Lutz  WB8EAS 

2951  S.  Moreland  Blvd 
Cleveland  OH  44120 

Delightful  theory,  but  I  don't  believe  it.  I  tend  to 
agree  with  the  economists  who  feel  that  histori- 
cally inflation  arrives  on  the  heels  of  the  night 
shift  at  the  Treasury  Department  when  they  print 
more  money  than  is  being  taken  out  of  the 
economy  in   taxes. 

.  ,  ,  Wayne 


CBers  and  Hams 

What's  going  to  happen  to  American  Private 
Citizens'  Radio?  That's  how  I  refer  to  all  civilian 
radio  communications,  chiefly  amateur  radio  and 
CB,  Today  we  are  in  the  strange  and  destructive 
position  of  having  two  separate  and  competing 
civilian  radio  services.  Competing  for  members, 
prestige,  and  frequencies.  How  absurd!  Under 
this  set-up  it*s  not  only  likely,  but  inevitable  that 
conflicts  wilJ  arise,  and  it's  not  too  difficult  to 
see  who's  been  winning  the  last  few  years.  I  don^t 
know  how^  this  unfortunate  situation  developed, 
completely. 

I  think  Wayne  Green  came  close  to  the 
solution  a  couple  of  months  ago  witJi  the 
proposal  of  the  Hobby  Class  license.  This  would 
move  tlie  CBers  and  their  sliort  range  com- 
munications to  220  MHz.  the  least  wanted  ham 
band.  Actually  it  was  sort  of  a  compromise,  but 
■the  important  point  is:  it  would  unite  the  two 
services  into  a  single  licensing  and  com- 
munication structure!  1  support  this  100  per 
cent.  But  There  are  problems,  875,000  CBers 
won't  relish  the  thought  of  replacing  their  equip- 
ment, just  so  they  can  call  themselves  hams.  Most 
people  already  think  they  are!! 

Anyway,  how  about  a  conciliatory  approach 
to  CB?  They're  not  dumb.  Most  are  friendly  and 


some  are  real  sharp  ops.  If  we  can  assimilate  and 

unite  the  two  radio  services,  not  abruptly  but  as 
fast  as  possible,  then  we  will  be  able  to  provide 
better  total  service,  and  we  will  have  a  much 
more  powerful  position  in  the  national  and 
international  radio  structure.  It  won't  be  easy, 
certainly;  but  it  appears  to  be  the  only  reasonable 
solution  that  would  not  interfere  with  the 
distinct  but  related  services  we  provide. 

Mark  R.  Hansen  WA9YEC 

1701  West  Eighth  Street 

Maxshfield  WI  54449 

Boo  Boo 

I  have  been  receiving  a  tremendous  ajnount  of 
mail  concerning  two  items  in  the  August  1970  73 
article  on  Log  Period ics.  Perhaps  you  could  print 
a  couple  of  items  to  straighten  things  out  for 
your  readers, 

In  middle  columns  of  Table  1  (p.45),  the  third 
longest  element  length  is  L404  ft.,  not  1304. 

Also,  perhaps  you  could  redraw  Fig.  1  with  a 
top    view    of    one    boom    assembly    only.    My 
questioners   aren't   sure   of  the  element  attach- 
ments which  are  not  clear  in  the  figure. 
Try  this  idea: 

TOP  VIEW  (one  boom) 


4    J'" 


8 


TO- 


12 


11 


13 


I  hope  you  can  find  room  to  put  this  in  73 
real  soon  to  straighten  people  out. 

BiU  Nagle  W3DUQ 

RD  1  Box  188A 

Honey  Brook  Pa  19344 


Busted 

My  fictional  story,  *That  Contest  Craze/'  in 
August  '70  issue  of  73  (in  w  hich  I  am  not  too 
kind  to  a  young  cop  who  slaps  on  me  a  $5 
parking  fine)  has  prompted  members  of  the 
police  force  here  and  abroad  to  write  and  say, 
^Wiiy  send  us  up.. .Don't  we  have  enough  trouble 
with  the  teenagers  without  an  oldie  like  you 
getting  on  the  wagon?" 

Constable  First  Class  Gerry  Letford  ( VE3FTV) 
has  added  another  S5  violation  fine  (No,l  10932) 
for  illegally  parking  mv  Big  Red  Kangaroo  car  in 
his  hometown  of  St,  Catherine,  Ontario  ^  and  if 
unpaid  a  warrant  follows. 

Another  Constable  ham  mate  in  the  north  of 
my  home  State  has  invited  me  up  for  a  few  days. 
He  guarantees  to  land  me  with  something  heavier 
than  a  parking  fine. 

In  the  local  village  here,  the  sergeant  (who 
borrows  my  73  mags)  booked  my  son  and  said, 
^Vd  prefer  to  give  this  ticket  to  your  OM. 


I 


+? 


DECEMBER    1970 


117 


T  A  GIOBE? 


Particularly  when  these  fabulous  Hammond  globes  (the 
best  in  the  biz)  are  available  at  our  LOW  PRICE. 

13"  inflatable  globe  {guaranteed,  by  the  way),  regularly 
selling  for  $15,  now  special,  while  they  last,  ONLY  $10. 

13"  lighted  globes,  reflularly  $25,  now  ONLY  $15.  We 
have  a  few  of  these  in  stock  and  when  they  are  gone, 
that  is  it. 

RADIO  BOOKSHOP 
Peterborough,  New  Hampshire  03458 


DUAL  GATE  MOSFET 

PRE-AMPS 


ANGUAR 


^ 


««U«fa.Ai¥  h*l  AWAi 


Its,!**    %■ 


to  175  MHz.  $21.95  ppd. 
to  300  MHz.  $25.95  ppd. 

NEW   FOR    1970! 
The  above  models  now  have  rf  gain  control. 

For  300  to  470  MHz 

See  Model  202  in  our  catalog. 

•  AiraTlabtft  from  S  MHi,  to  4S0  MHz,  Bdndwldth  ts 
approximately  3%   of  frequency. 

•  Volfag«  Odin   30  to  40   01   depending   on  frtqutncy. 

•  Two  Dual  Oote  MOSFET  amplifitr  stages  with  each 
having  a  tuned  Input  and  tuned  output.  Each  Dual 
Gate  MOSFET  It  actually  an  fntegrated  cascode  cir- 
cuit thui  giving  you  2  catcode  circuits  equivalent 
to  4  triodes. 

•  Except Jona fly  low  noise  (2,5  Dfl  at  ITSMHx.),  great- 
ly reduced  crosi  modulation  and  10  times  the  dy* 
fiamk  range  (iigna]  handling  capability)  of  the  best 
bi-polar  traniistori.  Alio  luperior  to  preamp$  using 
junction    FETt   and    Single    Gate    MOSFETs. 

•  Internal  connections  for  high  Impedance  AGC  or 
manual   qain   control    if   needed. 

m  Type  BNC  input  and  output  receptacles  for  minimum 
loii  at   UHF.  Standard   impedance   is  50-75   ohms. 

•  Carefully  tuned  at  our  laboratory  with  sweep  genera- 
tor and  oscilloscope  for  the  best  bandpass  character- 
istic. 

•  Full   wave    UHF  diodes  protect  input  transistor. 

•  Operates  on  6  to  \h  volts  DC,  S  to  15  Ma. 

New  York  Cify  and  State  residents  add  local  sales  tax. 

VANGUARD  LABS 

Dept.  H 
196-23  Jamaica  Ave.,  Hollis,  NY  11423 


Fve  already  paid  the  $5  fine  that  pi nh ended 
cop  put  on  me  in  the  story.  If  much  more  of  this 
keeps  up,  the  check  for  it  will  be  busted.  So 
please,  fellers,  lay  oft  I  know  when  Pm  beat,  FU 

go  quietly* 

Alan  Shawsmith  VK4SS 

West  End 

Brisbane 

Queensland 

AUSTRALIA 

Blunders^  Blunders 

I  still  think  your  magazine  is  the  greatest  for 
the  ham;  have  continued  to  think  so  ever  since  1 
subscribed  very  early  in  your  magazine^s  career. 
Keep  it  up. 

I  want  to  be  an  old  stinker  and  point  out  a 
couple  of  technical  goofs  in  Sept  73,  First,  a  little 
layout  problem  on  page  30.  Figures  1  and  2  are 
obviously  interchanged,  OthenAise,  I  have  to 
suspect  that  it  will  work  fine.  FlI  soon  know;  I 
am  in  the  process  of  converting  my  old  Heathkit 
grid  dipper,  since  most  of  the  key  parts  can  be 
used. 

Now,  look  at  page  26  (same  issue).  That 
voltage  dropper  has  something  goofed  up  on  it. 
The  way  it  is  drawn,  01  will  never  conduct 
Either  Ql  and  Q2  must  be  changed  to  cor- 
responding NPN  types  or  the  input  and  output 
polarities  must  be  switched  (with  a  corresponding 
reversal  of  the  zener  diode).  Otherwise,  it  seems 
to  be  a  good  scheme,  within  the  limitations 
already  mentioned  by  the  author. 

HotYy    K.    Lotie.    W7CQK 
220    Seneca    Ave    NW 
Rentont  Washinston  93055 

Yoxx'tb  right  in  both  cases,  Here^s  the  correction 
for  the  p.  26  gooL 


> 


20A 


JN 
I0-I6V 


> 


Q2 
2N3635 


OUT 

6.5-T5V 
Q-ISA 


iN;76I9 
B.2V 


^ 


.  Ken 


118 


73  MAGAZINE 


Objectivity 

This  letter  has  a  dual  purpose.  As  long  as  i 
must  write  to  you,  I  want  to  express  my  deep 
satisfaction  with  the  policies  of  the  mag*  73  mag 
has  reached  a  height  of  editorial  freedom  1  have 
not  encountered  even  in  Time  or  Newsweek.  73 
allows  each  of  its  editoriaJists  complete  freedom 
while  it  has  also  opened  its  pages  to  critical 
comment  and  occasional  discussion.  Your  head- 
ing to  the  'Tetters''  shows  that  you  are  inter- 
ested in  the  irate  and  sometimes  ignorant  views  as 
well  as  informed,  intelligent  ones, 

Jim  Altman  WAVUWL/2 
Box  6136,  River  Campus  Sta. 

Rochester  NY 


Politics,  Religion  and  Sex 

I  have  been  an  amateur  for  8  years  now  and 
have  become  somewhat  sick  with  the  regular 
routine  in  which  a  OSO  is  supposed  to  be  carried 
on.  A  few^  months  ago  I  began  to  experiment  on 
40  meters  in  the  way  of  trying  to  make  a  OSO 
more  meaningfuL  I  have  been  told  by  many 
people  on  the  bands  that  politics,  religion,  and 
sex  shouldn't  be  discussed  in  a  QSO,  but  my 
personal  feelings  on  this  subject  is  different  from 
that  of  the  majority  of  hams.  We  are  a  society 
and  almost  a  big  fraternity  of  people  with 
different  interests  and  thoughts  and  if  we  want  lo 
get  to  know  each  other  better,  we  should  learn 
by  our  QSOs  how  each  of  us  thinks.  In  the 
process  of  my  experiment  I  found  many  ama- 
teurs that  w^ent  along  with  my  ideas.  We  dis- 
cussed topics  ranging  from  Vietnam  to  women's 
Ube ration.  But  it  seems  that  whenever  we  would 
get  into  a  sticky  subject  one  of  the  members  of 
our  society  would  come  on  to  the  frequency  and 
throw  a  carrier  on,  whistle  Dixie,  or  sing  the  Star 
Spangled  Banner,  as  the  case  may  be.  As  other 
groups  on  the  amateur  bands  have  found,  when- 
ever someone  disagreed  with  what  you  are  doing 
-  no  matter  if  it  is  in  the  form  of  breaking  the 
norms  of  the  frequencies  or  conducting  a  net 
such  as  the  one  conducted  by  the  students  - 
choice  stations  show  their  inteUigence  by  throw- 
ing all  sorts  of  interference  on  the  frequency. 
These  kinds  of  people  don't  deserve  the  privilege 
of  operating  amateur  radio, 

I  d  like  to  relate  a  story  to  the  readers  of  73.  1 
have  a  very  good  friend  on  40  meters  (K2PJG)< 
Bob  is  crippled  from  .the  waist  down  and  is 
confined  to  a  wheelchair.  He  is  very  active  on 
ECARS  and  does  an  excellent  job  as  monitor 
control.  He  has  frequently  been  the  recipient  of 
all  kinds  of  insulting  remarks  and  has  almost 
given  up  hope  on  the  bands.  I  happened  to  be  on 
the  frequency  one  day  when  one  of  our  fellow 
hams  came  on  and  started  to  insult  Bob-  When  1 

broke  in,  the  fellow  insulted  me  as  well.  After  the 
OSO  I  ran  into  Bob  and  he  asked  me  if  1  knew  of 
anyone  who  wanted  to  buy  his  rig,  I  have  also 
thought  about  selhng  my  40  meter  equipment 

Going  back  to  my  original  topic  of  sex^ 
religion  and  politics,  I  feel  that  the  amateur 
bands  might  be  more  exciting  and  challenging  to 
hams  if  some  other  hams  would  try  my  method 
of  learning  and  discussing  the  problems  of  the 
world  today.  And  maybe  if  more  of  us  discussed 
problems  and  issues  of  the  world  and  the  amateur 
bands,  there  might  be  less  conflicts  and  dissatis- 
fied hams  today. 


Be  a  PtONECR  in  HASyi  TV 
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OWall  sized  (23"'  x  3TT 
OShipped  fiat  in  mailing  tube 
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OMost  complete  map  available 

O  Up-to^<late  world  prefixes  shown 

P^TPAID  O  Color  in  countries  as  worked 

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Bay  iavishly!  Order  today  from: 

73  MAP,  Peterborough  NH  03458 


I 


DECEMBER    1970 


119 


CUSTUI  MADE  DX  CHMIIS 

When  you  need  a  DX  bear- 
ing you  need  It  immediately. 
You  don't  want  to  have  to 
look  it  up  on  a  map  or  fiddle 
with  a  globe. 

These  Custom  DX  Charts 
are  computer  print-outs  for 
your  exact  shack  location  and 
give  the  bearing  and  mileage 
for  every  country  in  the  world. 
They  are  printed  out  by  call 
prefix  for  speed  of  location 
and  the  capital  city  is  indi- 
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Custom  DX  Chart 


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postage  prepaid 


Peterborough  NH 
03458 


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colls  with  Hustler  4-87 V  trap  vertical, 
fcr  expanded  bandwidth  up  to  ?40  KHz 
on  75/flO  meters.  {See  article  "Two  on 
Top"  by  W6AJ2,  73  Magazine,  May 
1969.)  Or  use  to  build  your  own  5-band 
vertical  antenna  (Article  "1-2-3-4  Oti  a 
Mast''  by  W6IEL.  Popular  Electronfca.  August  1970). 

Excellent  foundation  for  Ham  and  CB  ground  plana  radials,  or  "spider"  for 
mounting  spreadera  on  $mall  cubical  ^i^ads. 

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If  any  stations  wish  to  discuss  the  topics  I 
have  mentioned,  just  drop  me  a  line  with  a  sked 
and  if  possible  we  will  have  an  out*of-the- 
ordinary  QSO-  Which  is  pretty  rare  to  find  these 

days. 

Jim  MiUner 

116  Comw^aU  Ave. 

Trenton  NJ 

Incentive  Licensing  —  Fro  and  Con 

The  following  letters  are  representative  sam- 
ples of  letters  received  in  response  to  73*s 
incentive  licensing  questionnaire.  Those  opposed 
to  IL  far  outnumbered  those  for;  thus^  we  cannot 
reprint  ail  of  the  letters  against  the  principle, 
even  though  the  'Tor"  ietters  reprinted  here  are 
the  sum  total  of  all  letters  backing  incentive 
licensing  we  received  from  amateurs  as  of  1 
October^ 

Pro 

Anything  as  worthwhile  as  amateur  radio  is 
worth  the  time  and  effort  involved  in  learning  the 
code  (20  wpm).  My  gripe  is  that  you  may 
interpret  my  responses  to  your  biased  advantage, 
so  I  have  only  answered  the  questions  you  will 
have  difficulty  biasing. 

Jerry  Poi;>e  W4YRY 

5112  Cedarwood  Dr. 

Raleigh  NC  27609 

1  am  for  incentive  licensing,  but  I  think  the 
principle  should  be  reconsidered,  perhaps  favor- 
mg  new  bands  as  an  incentive. 

Jack  Petree  WB40VX 

Box  5175 

Roanoke  VA  24012 


The  only  answer  I  can  give  to  anyone  op- 
posing an  incentive  of  any  kind  is  that  he  must  be 

classed  as  too  lazy  to  want  to  better  himself  and 
(improve)  his  knowledge* 

BiU  Cooke  W3GBB 

427  Grain  Hwy  NE 

Glen  Burnie  MD 

I  favor  IL,  but  all  amateurs  who  held  the 
original  Class  A  license  should  be  issued  the  Extra 
automatically.  They  earned  the  top  benefits,  so 
why  take  them  away? 

Paul  Fritich  W3HHC 

11  Oakleigh  Rd. 

Allentown  PA  18104 

I  have  Extra  class,.-took  many  days  of  code 
practice  but  consider  the  time  well  spent.  Some 
people  will  never  pass  the  Extra,  but  most  have 
the  capability  to  do  so  if  they  really  want  to. 

Bob  WB9ABT 

Rt  1  Box  269 

Lake  Zurich  IL  60047 

Twenty  wpm  is  the  speed  of  the  expert  and 
Extra  class  should  be  expert.  Incentive  licensing 
gives  one  something  to  strive  for,  keeps  the  mind 
strong.  Without  (such  an  incentive  program) 
some  people  would  tend  to  grow  stale.  I  think 
incentive  licensing  should  be  as  the  name  implies 
-  an  incentive,  something  extra  -  not  something 
restored  that  was  previously  taken  away, 

John  Mrozinski  WB2EX1 

155  Eckford  Street 

Brooklyn  NY  11222 


120 


73  MAGAZINE 


Con 

*lndian  giving"  -  that  is,  offering  something 
in  exchange  for  a  demonstrated  proficiency  in 
certain  skills  then  revoking  that  something  —  is  a 
very  poor  way  of  creating  goodwill, 

M*  W,  Macy  W9UM 

Rt4 
Syracuse  NY  46567 

I  want  to  see  ham  radio  grow  -  why  not  give  it 
a  chance?  The  Generals  should  be  given  back  all 
the  bands  taken  from  them.  If  incentive  is 
necessary,  lei  the  Extra  have  a  small  part  of  one 
band  for  phone  and  code.  It  is  not  hard  to  see 
why  so  many  people  say  to  hell  with  the  FCC 
and  the  ARRL  and  go  to  CB  where  they  can  have 
almost  as  much  enjoyment  and  can  work  the 
country  without  all  this  nonsense! 

Roy  Gunter  K9GNK 

1637  Rock  Spring  Dr. 

Alton  IL  62002 

In  spite  of  the  fact  that  I  am  against  IL,  don't 
get  the  idea  that  I  do  not  study  and  strive  to 
improve  my  knowledge  of  amateur  radio.  It's  just 
that  I  would  rather  see  us  go  back  to  the  previous 
system. 

Richard  Weiner  WA8WMC 

Rt  2     2660  Lincoln  Ed 

Ludington  MI  49431 

Hams  in  Alaska  are  under  a  particular  hard- 
ship with  respect  to  upgrading  because  of  the 
tremendous  distances  involved  in  getting  to 
Anchorage  (where  exams  are  administered).  But  I 
am  against  IL  regardless  of  where  I  am  located. 
Thanks  for  standing  up  for  the  majority  of 
amateurs,  who  are  against  incentive  licensing. 

Jack  Bone  KL7GKY 
Sitka,  Alaska 

I'm    certainly   glad    the   FCC    doesn't   have 

anything  to  do  with  my  birth  certificate,  mar- 
riage license,  bachelor's  degree,  etc.,  where  re- 
vocation  of  privileges  could  really  be  serious! 

C.  H-  Smith  K»ERL 

611  Wesley  Dr. 

Farmington  MO  63640 

Granting  extra  privileges  to  a  few  at  the 
expense  of  the  majority  is  hardly  justifiable.  The 
ARRL  never  proved  it  was  speaking  for  a 
majority  -  surely  the  FCC  must  know  that! 

Theron  LriOie  V\^A2UrG 

190  Henrietta  St* 

Rochester  NY  14620 

I  don't  favor  IL  the  way  the  ARRL  presented 
it  and  as  far  as  I  am  concerned  they  can  go  to  h— 
with  their  incentive  licensing* 

John  PerUck  WBQADO 

3400  Edgewood  Ave  North 

Minneapolis  MN  55427 

Thanks  for  giving  us  hams  the  opportunity  to 
express  our  feelings  about  IL.  I  do  not  favor  the 
principle,  I  can  see  no  useful  purpose  in  knowing 
how  to  send  and  receive  CW  at  20  wpm  unless 
someone  simply  wants  to  be  a  faster  operator. 
The  entire  mess  has  dealt  a  severe  blow  Xo 
amateur  radio;  I  sincerely  hope  the  FCC  will 
reopen  the  whole  matter  for  reconsideration, 

Kenneth  Cregar  K3KBG 
3411  Stoudt's  Ferry  Bridge  Rd 

Reading  FA  19605 


National  NCX-fOOO  Transceiver 


Transistorized  trar>scei\/er  (except  for  driver 
and  final),  runs  1000  watts,  yet  is  just  a  bit 
larger  than  ordinary  transceiver!  Complete  kilo- 
watt ham  station  in  one  small,  light  unit.  Tested 
by  73  staff  and  found  to  be  a  really  great  unit. 

The  wortd  of  transistors  and  ICs  makes  ft 
possible  to  have  a  complete  kilowatt  all  band 
ham  station  in  one  small  unitl  Not  much  larger 
than  normal  transceiver  yets  runs  solid  1000 
watts.  Extremely  sensitive,  processed  speech  for 
maximum  umph  when  wanted,  everything  you 
need  in  one  Httle  package.  Only  tubes  are  driver 
and  final. 

The  NCX-1000  lists  for  $1100  and  is  an 
unusual  bargain  at  that  price.  The  73  test  unit, 
used  a  few  days  and  under  brand  new  factory 
warranty,  is  available  to  the  first  $700  check 
received. 

73  MAGAZINE 

RBOROUGH  NH  03458 


Radio  Amateur 
Emblems  engraved 
with  your  call  letters, 


n   Gold 

□    Rhodium 


call  letters 
$6.00  Ea. 


^9.0.Z^ 


□  Gold 

□  Rhodium 

call  letters 
$6.00  Ea. 


/v?^;  ^  :  ■ 


All  iflu^trotions 
pre  octual  size. 


,  w  9  X  yz  J 


□  Gold 

□  Rhodium 

'^' '  J    call  letters 


Two  or  more  'emblems  at  the  same  time  $5.00  each. 


fttfsfc  Orrfer  To:  RADIO  AMATEUR  CALLBOOK,  Inc. 

Dept.  B    925  Sherwood  Drive,  Lake  Bluff,  III.  60044 


DECEMBER    1970 


121 


JEFF-TRONICS 


SURPLUS  BARGAINS 
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160  102  1.5  5  pF  50d 

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3  32  pF  80^ 

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2.7-10.8  pF  bulterflv  SOtf 

2.3  14.2  pF  deferential  B04 


160  127 
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HUM1DISTATS  Hon  ev  well 
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creasing  humidity.  17/8'*  n  11/8"  x 
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switchrng  point  extends  from  end, 
45c  ea.,  5  for  S2,  100  tor  S30. 

BC    343    receiver    200-500   kc,    1.5-18 
mc,  converted   115V   to  60  cycle  excel 
lent  used     , 

BC  221  frequency  meter,  125  kc,  20  mc, 
115V  60  cycle  power  w/crystal  Si 
calibration  book  &  mstructfon  book. 
Excellent  used    ...,,....     


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LAPEL  BADGES 

IMaine  and  caM  identifies  you  at  cfub  meetings, 
hamfests,  busted  pot  parties.  Hand  engraved  by 
skilfed  New  Hampshire  craftsnnan  with  loving 
care.  Only  one  lousy  dollar.  Send  first  nanie 
and  call  and  buck  to; 

RADIO  BOOKSHOP,  Peterborough  NH  03458 


Desk  Call  Plate  ofi/y  $2.00! 

Up  to  20  letters  on  a  desk  plate,  em- 
bossed white  letters  on  walnut  back- 
ground; ebony  stand.  Looks  great  on  rig 
with  your  name  and  calL  Watch  envy  race 
through  your  neighborhood.  Send  along 
20  well  chosen  letters  (spaces  count  as 
letters  too),  include  a  nice  fresh  two 
dollar  bill,  and  give  us  a  strong  hint  on 
where  to  mail  the  exquisite  piece  of 
craftsmanship. 

RADIO  BOOKSHOP,  Peterborough  NH  03458 


My  low  opinion  of  IL  h  colored  Uy  the 
pcrsonul  blight  of  downgmding  after  more  than  a 
haltWenturv  of  Eood  bchuvjor  on  the  ham  bands. 
It  all  seems  so  unnecessary.  I  would  think  that 
old  experienced  people  could  be  let  alone  and 
not  subjected  to  such  indignities  as  have  been 
dreamed  up  from  time  lo  time  by  the  ARRL.  I 
cdui  be  mad  at  tlie  I 'XX\  who  -  I  am  sure  - 
simply  fell  that  Newjnglon  could  hardly  be 
wrong.  As  a  matter  of  fact  I  recall  that  the  t^CC 
turned  this  thing  down  some  years  earlier  on  the 
basis  that  it  would  lead  to  an  elite  establishment 
with  a  sLtpposedly  democratic  government  put  in 
the  anomalous  position  of  enforcing  a  caste 
system. 

R*  A.  Hllferty  W2HEY 

Box  409 
Miller  Place,  Li;  NY  11764 

I  hope  that  someday  this  incentive  licensing 
tliiniz  can  be  rehashed,., Now  I  have  a  General 
license  which  restricts  me  to  certain  portions  of 
the  amateur  bands  ...and  ihc  ironic  thing  is  that 
EMias  seem  to  operate  in  the  General  portion  of 
the  band. 

John  Stagnaro  W6MAB 
2305  Panorama  DrXa  Crescenta  CA  91214 

I  don't  have  any  idea  how  much  influence 
you  will  be  able  to  swing  in  your  effort  to 
convince  I  CC  that  this  whole  thing  was  ill- 
advised,  but  if  1  can  help  by  sending  you  my 
opinions,  then  it  is  the  least  I  can  do.  I  am  against 
IL.  and  would  only  be  for  a  20  wpm  requirement 
if  use  of  a  typewriter  were  optional. 

BUI  GuUedge  W9LWG 

Rt  3  Box  56 

Phillips  WI  54555 


r'lnally  someone  uses  a  magazine  to  get 
3plnions  on  the  IL  program  on  a  national  scale.  I 
lopc  that  60%  of  votes  is  not  the  losing 
percentage  (see  p.  9  QST  Sep  1970)- 

Harris  WBSBTV 


It's  not  incentive  licensing  when  the  FCC 
narrows  and  removes  frequencies  so  as  to  load 
the  remaining  spectrum  with  nets  and  phone 
patches.  And  cramming  ARRL  activities  into  the 
highly  congested  remaining  portions  of  the  bands 
is  idiotic. 

R.  W.  Daniels  K^KYH 

Rt2  Box  212 

Aitken  MN  56431 

IL  was  supposed  to  be  a  step  above  General; 
instead,  the  space  between  Novice  and  Lxtra  was 
split  in  three  rather  than  two.  And  the  present 
Genera!  is  not  up  to  his  predecessor,  who  knows 
half  the  Advanced  test  from  his  old  General 
exam.  Thus,  either  increase  the  exam  require* 
men  15  for  Advanced  or  throw  it  out!  Let  those 
who  know  the  code  at  high  speed  get  credit  for 
iU  but  let  the  chap  who  doesn^t  know  it 
demonstrate  some  alternate  ability.  If  the  FCC 
insists  on  restricted  privileges,  how  about  power? 
New  Generals  to  get  150W,  maybe  Advanced  and 
Lxtras  could  get  the  full  gallon. 

Joel  Look  WIKCR 

Box  25 
Claremont  NH  03743 


122 


/3  MAGAZINE 


Radio  Interference  Reduction 

Some  hams  try  to  purchase  new  electric 
razors  for  neighbors  in  an  attempt  to  reduce 
existing  razor  QRM.  However,  attempts  I  have 
made  to  find  any  razor  thut  is  treated  to  reduce 
ORM,  have  not  been  successful  at  dealers,  rinal- 
ly,  I  received  a  reply  from  a  SEARS  buyer  who 
said  that  their  92737  razor  (Austrian)  claimed  to 
be  so  treated.  I  had  read  many  instruction  sheets 
with  new  razors  without  seeing  any  such  com- 
ment on  other  products, 

[  think  that  the  magazines  should  be  willing 
to  mention  this,  and  to  Ust  products  that  have 
reduced  QRM, 

Note  Public  Law  90-379,  90th  Congress, 
which  amends  the  Comm.  Act  of  1934,  permit- 
ting FCC  to  regulate  the  interference  potential  of 
devices.  QST  published  a  request  for  letters  to 
FCC  suggesting  items  heading  such  regulation. 

I  think  that  amateurs  should  encourage  FCC 
to  bring  out  at  least  a  general  requirement  that 
household  appliances  be  treated  for  reduction  of 
QRM,  and  especially  that  tiicr  mo  stats  be  treated 
to  prevent  "hanging"  of  the  contacts  in  a 
sparking  condition.  Also,  essentially  all  light 
switches  could  be  so  treated  -  which  1  under- 
stood was  required  in  (ranee  35  years  ago.  I 
encourage  the  magazines  to  stir  op  a  little 
thought  on  the  use  of  the  Public  Law  to  reduce 
QRM. 

E,  H-Conklin  K6KA 

402  Olivet  a  PL  Box  1 

La  Canada  CA 

Sparkling 

Keep  up  the  good  work  with  73  Magazine. 
You  have  a  good  following  at  KEYN.  We  have 
four  active  hams  on  the  staff.  Our  News  Director 
K0WTM  has  his  two  young  sons  hcensed  as 
Novices.  Fm  now  working  on  the  general  man- 
ager and  his  oldest  son  and  hope  to  get  them 
tickets.  The  station  supports  the  W0DKO  re- 
peater with  tower  space  and  power.  You  can 
imagine  the  response  a  CB  organization  receives 
when  our  program  director  (W5MGC)  takes  the 
call.  Our  weekend  disc  jockey  and  engineer 
WA(JTHQ  is  a  senior  at  Wichita  North  High 
SchooL  Oh  yes,  we  also  operate  a  station 
WA0ZZX  on  2  meter  FM  from  the  KEYN 
studios. 

Anyway  we  here  at  KEYN  heavily  support 
Amateur  Radio  and  73  Magazine.  Each  copy  I 
receive  from  my  new  life  subscription  is  well 
digested  before  I  safely  file  it  away. 

Larrv  Waggoner  WA9QPM 
KEYN,  3357  W.  Centra] 

Wichita  KS 

Lackluster 

I  keep  reading  in  the  letters  column  tlie 
bouquets  that  come  your  way  regarding  the 
magazine.  I  started  subscribing  some  time  ago 
and  thought  the  same  way  -  even  got  the  back 
issue  Gunsmoke  and  enjoyed  them  all.  However, 
in  the  last  year  or  so,  it  seems  to  me  that  73  has 
lost  its  sparkle  and  is  becoming  a  lackluster 
publication,  'aybe  it's  me,  maybe  not.  Anyway,  it 
seems  to  be  turning  into  a  specialty-type  maga- 
zine geared  for  VHF-Novice  interests.  Of  course, 
maybe  this  is  what  you  want. 

I  wonder  how  much  the  advertiser  influences 
editorial  policy?  I  have  yet  to  see  an  article 
saying  that  a  particular  piece  of  equipment  is  a 
piece  of  junk.  These  *' reviews"  in  all  the  maga- 
zines claim    that   anything  is  the  biggest  thing 


■ 


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123 


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UkhJ  lor  int«fn#l  cKa&t  wtHng,  •ntenn«  cOuptirH}.  RF  CDUplmg  bar/i^een 
itaQin.  fftc.  Random  langthi  from  35  foot  to  150  foot.  Cohort:  black,  rad^ 
brown,  blue,  {|rav.  Orange  R#9giar  prka-  23^  per  foot.  Our  p€i^^  ^  p«r 
foot  $3.00  p»r  100ft 

4B6  Khi  cfl ramie  Utxtn  Xyo*  BF^55-A.  Thtn  fillers  vwill  help  to  shftrpen 
the  wltctivttv  of  moit  tati  uiing  45B  Khz  IP's  Uie  bctdss  cathodfl  bin 
rattttor  in  plac*  Of  •  opKilor.  or  in  tr«n»istorifed  Ht£,  Kron  The  emitter 
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ImpedaoDi  incraaaal  rapkjty  ai  you  feir^a  455  Khi:.  Plan  your  own  LC 
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TOROID  POWER  TRANSFORMERS 

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out  m  70  waffi  S«t  42  -55  volts  DC  bios.  Sec.  #3  1.2  volts  AC  for 
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TRANSFORMERS 

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since  ttie  ice  cream  cone.  For  instance,  I  had  a 
Swan  VHF-  antenna,  made  by  the  Stockton  man, 
that  tlew  apart  in  the  wind,  mainly  because  of 
insLifncicnl  hardware,  I  wrote  something  about  it 
and  sent  it  in  -  no  responiie.  Wrote  another  and 
sent  it  to  QST  -  and  got  a  nice  letter  from  the 
technical  consultant  that  they  only  checked  the  2 
meter,  not  the  6  meter. 

I  believe  there  is  a  little  more  than  a  year  to 
go  on  my  73  subscription  and  I  frankly  don't 

intend  to  renew  it  for  a  lack  of  interest  in  the 
contents. 

Paul  Schuett  WA6CPF 

A  lot  can  happen  in  a  year 

.  ,  ,  Ken 

Easter  i&Land 

On  March  20,  1970<  I  was  licensed  to  operate 
my  amateur  station  from  Easter  Island  with  the 
call  sign:  CE0AE-  I  have  been  operating  with  this 
sign  since  May  20,  and  work  all  bands,  CW  and 
SSn.  Only  twice  have  I  operated  above  21,400  on 
the  15  meter  band.  My  name  is  ''Dave",  my  QSL 
Manager  is  WA3HUP,  and  my  QSL  card  is  red 
and  white.  I  do  NOT  have  an  APO  address.  I  have 
received  fewer  than  one  QSL  card  for  every  three 
contacts,  and  would  appreciate  more.  My  usual 
frequencies  are:   28,550  -  21,360  -  14,332  - 

7030  -  3530.  Fr.  David  h.  Reddy,  O.  F.  M. 

Parroquia 
Isla  Be  Pascua,  Chile 

Flamboyant 

In  my  opinion  your  increasingly  flamboyant 
lieadlines  lower  the  appearance  and  appeal  of  73 
to  the  level  of  cheap  trash  like  CQ  and  PE,  and 
waste  space  that  could  otherwise  be  devoted  to 
several  more  pages  of  articles. 

73  is  not  Movie  Mirror  or  True  Confessions* 
For  examples  of  proper  headlines  for  a  technical 


magazine  sec  July  QST. 


R-  B.  Kuehn  W(^HKF 

St,  Paul 

MN 


The  Good  .  ,  • 

A  friend  loaned  me  the  June  and  July  copies 
of  73  magazine-  They're  the  greatest.  1  saw  your 
notice  about  a  bundle  of  back  issues  of  73  for 
$6-00*  My  check's  enclosed,  Hope  Vm  not  too 
late, 

Vm  in  a  Code  &  Theory  class.  As  soon  as  1  get 
my  Novice  ticket,  Vll  subscribe  to  your  fine 
magazine,  Can*l  see  how  any  amateur  can  be 
Without  it. 

My  sentiments  are  with  your  point  of  view  on 
every  issue  in  these  two  issues  of  73.  Keep  up  the 
good  work. 

JijTi  Edwards 
Chiilicothe  OH 

.  .  .  and  the  Bad! 

In  your  recent  letter  asking  me  to  renew  my 
subscription  you  said  that  you  were  worried  that 
1  would  not  renew  my  subscription.  Well  Gentle- 
men I  would  like  to  say  tliat  you  had  better  start 
worrying  for  your  publication  has  become  sheer 
garbage  in  the  past  9  months.  If  you  want  to  sell 
your  mag,  you  had  belter  try  the  funny  farm  for 
they  are  the  only  people  that  might  find  your 
magazine  of  interest! 

Lloyd  Dotese  Jr,  WN5ZZF 
220  E,  Maple  Ridge  Dr. 

Metaire  LA 


124 


73  MAGAZINE 


Mideast 

Wayne's  helping  Hussein  out  was  a  true 
gesture    of    gentlemanllness    in    the    true    ham 

spirit  I  guess  you  just  have  to  remind  some 
people  that  you  are  not  a  discriminating  person. 
To  me,  Hussein  is  a  person  who  has  same 
common  interest  as  myself,  ham  radio,  and  this 
ham  fellowship  (to  me  anyway)  is  not  affected 
by  either  race,  creed,  color,  religion  or  place  of 
birth.  As  for  those  childish  kids  who  say,  ''OK, 
now  go  to  Israel  or  you're  anti",  let  them  go 
somewhere! 

Wayne  has  befriended  a  great  ham  for  all  of 
us.  May  1  remind  some  people  that  Hussein  has 
understandable  troubles  of  his  own  and  he  gets 
on  the  bands  (like  most  of  us,  anyway)  to  relax 
and  take  it  easy.  You  must  forgive  some  of  us, 
Hussein,  for  those  pileups,  but  you're  still  a  rare 
one  for  many  of  us.  Take  it  easy  and  as  long  as 
you  are  a  member  of  the  fellowship  of  hamdom, 
I  won't  yell  at  you  about  the  Mideast,  My 
feelings  remain  much  the  same  for  Wayne.  Keep 

up  the  good  work.  Times,  they  are  a-changin\ 

Chip  Cohen  WAIJHO 


Ham  Critic 

It  Strikes  me,  Wayne,  that  the  technical 
quality  of  the  articles  is  slipping.  "More  Notes  On 
Diode  Stacks'"'  must  have  been  written  for  the 
Novices  or  the  XYLs.  Maybe  my  interests  just 
were  not  touched  -  we'll  let  it  go  at  that. 

Brown  (W9HBF)  must  not  have  listened 
recently  on  CB;  further,  he  should  keep  track  of 
what  hams  do  in  emergency  communications,  I 
could  have  enjoyed  the  Sept.  issue  a  lot  more  if 
this  article  had  not  been  in  there!  QRP,  yes  - 
CB,  no! 

WB41TN  could  have  something  real  useful 
going  with  his  file-box  series  if  he  handles  it 
correctly^  and  produces  some  really  handy  gad- 
gets for  the  shack. 

One  has  to  question  the  use  of  the  word 
"waveguide*'  in  KICLL's  attenuator  article.  Two 
coffee  cans  soldered  together  will  do  the  same 
job  only  it\  called  shielding! 

There  are  a  lot  of  pluses  in  the  Sept  issue: 
W7PUG's  CW  ID  Generator,  WA2IKL's  IC 
Testers  J  K6MVH's  Antenna  Separation,  and 
Douglas's  Relay,  etc„  The  study  guide  material  is 
always  excellent.  Too,  WB6YVT's  2M  Converter 
looks  good. 

It  is  noted  that  the  number  of  advertisers 
seems  to  be  picking  up,  Wayne,  Anyway,  I  guess 
you  know  that  I  read  ''It"  from  cover-to-cover. 
Thanks. 

73's  Carl  K2IA 

10-16  Burbank  Street 

Fair  Lawn  NJ 

In  regard  to  the  letter  by  Ernest  Robarge, 
who  says  he  would  make  a  good  ham  except  he 
can't  pass  the  code  exam,  it  really  made  me 
laugh.  Over  600  hours  of  code  and  he  still  can't 
pass  it.  I  took  16  hours  for  my  Novice  and  passed 
with  no  trouble.  So  as  far  as  code  goes  Pm  okay 
but  I  can't  get  enough  theory  to  pass  the  General. 
But  I'm  still  going  to  keep  on  and  not  write  to  73 
to  teU  the  world  what  a  fool  1  am. 

Bob  Mackey  WN9ERZ 

Somebody's  sure  been  writing  letters  over  your 
signature,  ,  .  .  Ken 


Special-Purpose  Receivers,  Panadapter 

RAK-7  complete,  w/dwg,  15-600  khz  TRF  ,  .  .  J25.0Q 
RFI  (Noise  8t  Field  Strength  Meters)  are  basically 
radio  rcvrs.  TS  587/U  (no  ant.  accessories)  some- 
what modified  as  an  RFI  Meter.  OK  as  rcvr,  15-400 
mhz,  $195.00,  Ferris  #32 A,  ;15-20  mhz,  complete, 
OHC  w/charts  &  book,  $175.  #32B  is  later  model, 
$275'.  Navy  OF1,  .15-17/2  nihz,  OHC,  with  book,  $75, 
MORE  PR0FESS10MAL  setups,  to  $4000.00,  Stoddart 
and  Empire  Devices:  ASK!  Also  ask  about  SPECTRUM 
ANALYZERS,  if  interested, 

455  kh^  Panadapter,  various  models,  all  100%     ^     ^_« 

OK,  all  with  instruction  books 3/.DU 

\N\NV  Comparator  Rcvr  has  meter  to  zero  beat  your 
signal  with  WWV  switched  tuning  at  2^3/5/10/15/20/25 
mhz.  Beckman  #905R  sold  for  $650.  From  us  - 

OHC  and  with  book *  /3.UU 


Hi  Sensitivity  Wide-Band  AM/FM  RCVR 

3^_1000  MHz:  AN/ALR-5  consists  of  brand  new 
Tuner/Converter  D\/-253/ALR  in  original  factory  pack 
and  an  exc,  used,  checked  OK  &i  grtd.  main  rcvr  R-444 
modified  for  120  v,  50/60  hz.  Packed  with  each  tuner  is 
the  factory  checkout  sheet.  The  one  we  opened  showed 
SENSITIVITY:  T.l  uv  at  33.3  mhz,  0.9  at  133  mhz,  5 
at  538  mhz,  A'A  at  778  mh2,  7  at  1  ghs;  w/book, 
8t  pwr-input  plug,  all  for .,*,,...,.. 


275.00 


R-390/URR       Rcvr:       Collins      xtl-zero-beating, 
drifttess  receiver,  grtd  100%  perfect ,  . 

R-390A/URR  has  mech.  filters,  grtd  perfect   ,  ,  . 


795JD 
995.00 


ReguL  Pwr  Sply  for  Command,  LM,  Etc. 

PP'106/U:  Metered,  Knob-adjustable  90-270  v  up  to  80 
ma  dc;  also  select  an  AC  of  6-3  v  5A,  or  12.6  v  2>iA  or 
28  V  2/2  A.  With  mating  output  plug  &  all  tech. 
data,  Shpg,  wt  50  lbs  ...... 

Bargains  which  the  above  will  power: 

LM-{*)    Freq.    Meter;  .125-20   MHz,    .01%,    CW 

w(th    serial-matched    calib.     book,     tech,    data, 

plug, 

Shfpplng  wt.  16  lbs ,,*«,, .  .  . 

Same,  less  calib.  book  ......................  27.50 

A.R.C.  R1  1A:  Modern  Q-5'er  rcvr  190-550  khz.  .  .  2.95 
A.R.C.  R22:  540  — 1600  khz  rcvr  w/tuning  graph  .  17.9& 
A.R.C.  R32;  108-132  mhz  rcvr 32.50 


19.50 


or   AM, 
matmg 

.57,50 


IF  YOU  DON'T  SEE  IT  HERE,  ASK  FOR  IT!  But  don't 
ask  for  a  general  catalog.  .  .we  believe  that  is  nonsense  in 
surplus.  .  .we  get  new  things  in  almost  every  day  I  WE 
ALSO  BUY!  Bo  iell  us  what  you  have,  condition,  and 
your  asking  price* 


R.  E.  GOODHEART  CO.,  INC, 

Box  1220  GC,  Beverly  HiJIs,  Calif.  902 T 3 
Phones:  Area  Code  213,  Office  272-5707 


Thousands  of  IWts 

NO  FLIERS 

DOW  TRADING  CO.JNC. 

ELECTRONIC  PARTS  &  EQUIPMENT 

1829  E.  HUNTINGTON  DRIVE 
DUARTE,  CALIFORNIA  91010  357-3763 


SCOTT'S  QSL  SERVICE 

1510  Lynnvfew    Houston,  Texas   77055    USA 

Fact!  We  forward  cards  anywhere  (except  betwet^n 
continental  U.S.)  for  34  •  We  offer  Stateside  and  DX 
roanae^^  service  at  an  unbelievable  low  price  ♦We  keep  an 
up  to  date  day  to  day  Ust  of  QSL  managers  to  which  we 
forward  cards  along  with  SASE^  supplied  Dy  us* 

Reason  far  usine  our  service:  There  is  no  cheaper  way 
to  QSL  than  us  •  No  easier  way  to  QSL  than  us  # 
You  do  not  have  the  time  or  money  to  keep  up  with  and 
hunt  for  QSL  managers  and  QTH's  for  every  station  in  the 
world,  we  do  —  it's  our  business. 

WRITE  FOR  FREE  INFORMATION  TODAY 


DECEMBER    1970 


125 


.>,  •  •;•  -vr.    *  ;  ■■x..:;' 


A7000 


A7001 


A7000 

Contains  cadmium  sulfide  photocell,  potenti- 
ometer, relay,  lamp  &  Fairchild  2N2657.  1-5/8"  x 
1-1/4".  Originally  used  as  exposure  meter  control. 
Complete  circuit  diagram  &  application  data   .  1.25 

A7001 

Contains  cadmium  sulfide  photocell,  2— 500J2 vari- 
able resistors,  8i  Fa  ire  hi  Id  2  N  2240.  Presence  or 
absence  of  light  changes  bias  on  transistor.  Useful 
for  all  types  of  alarm  &  light  sensing  devices. 
Complete  with  diagram 75  ea. 


3  A7000&  3A7001 


li      >      I 


.5.00 


aniriiEii  man  specims 


Ag082 

Honeywell  Computer  boards,  4%"  x  12",  Transis* 
tors,  diodes,  zeners,  capacitor,  precision  resistors, 
heat  sink,  trimmers,  etc,  2  different  boards   ,    1,00 


A9093 

Honeywell  Power  Board  contains  4  2N1137B  80 
watt  PIMP  power  transistors,  8  Top  Hat  diodes,  8 
precision  resistors  &  41 N 642  diodes  stock,   1,25  ea. 


A2040   Sangamo    or    Pyramid    4'A*'    x    1%"   4000 
MFD  50V .50  5/2.00 

A4016    FET   Field  Effect  Transistor  TO-18  25V 
Source  to  Gate  N  Channel    50  5/2.00 

A4017  Tunnel  Diode  similar  to  1N371 7   -50  5/2.00 

$1.00  FREE  WITH  $10.00  ORDER 
MINIMUM  ORDER  $3.00 


Lots   of  other  items — send   for  free   flier:    All  mer- 
chandise  fully   guaranteed^   Please   include  post- 
age:   excess  will   be   refunded. 


A  DELTA  ELECTRONICS  CO. 
BOX  1,  LYNN,  MASSACHUSETTS  01903 


SLOW  SCAN  TV 

Now  for  the  first  time  din  S.S,  monkor  designed  for  your 
own    custom    instaMation.    Available    m   3  econonay   kits. 

KIT  1  PC   Boards  only  (2  req.)  ea.  S     9.95 

KIT  2  PC   Boards  {Both)  Ei  all  parts  (unwired) 
KIT  3  P,C.  Boards  Wired  &  tested 
Power  Supply  Kit-No  chassis 
Complete  Monitor-  tn  handsome  cabinet 

All  k  KS  lube  lypewith  instructions, 
CRTs^  Pow^r  Supplies,  av^tl  cabinets  not  included 

E.K.Y.  VIDEO  VISION  CO.  Box  15,  Stockhofm  NJ  07460 


$  80,00 
$125.00 
S  54,95 
S298.00 


SCHEMATICS  AVAILABLE  FROM  73 

$1.00  each 

ARR-1S  from  June  1965  73,  page  78. 
ARC-27  2M  Guard  Channel  Receiver, 
SSB  Transceiver,  N6v-  1961  73,  page  23. 
R508/ARC,  June  1965  page  48,  before  &  after. 
73  Magazine,  Peterborough,  N.H.  03468 


\      if    ^        „   ! 


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Q.. 


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G:R,  Frequency  IVleas* 

uring  Equipment 

Type  11 05 A 

This  primary  frequency 
standard  will  measure 
from  1  Hz  to  over  100 
MHz  with  an  accuracy  ot 
one  cycle  up  to  10  IVIHz. 
This  IS  a  laboratory  stan- 
dard used  primarily  for 
calibrating  other  equip- 
ment. This  is  the  last 
word  in  frequency  stan- 
dards. Send  for  details. 
SPECIAL  ..,.$1935.00 


DGP  COMPANY  box  431  Jaftrey,  N.H.  03452 


126 


Atlanta  Repeater  Problem 
K6MVH's  recent  editorial  on  the  Atlanta 
repeater  was  an  accurate  description  of  the 
situation  as  it  now  exists  in  that  area.  I  lived  in 
Atlanta  for  over  five  years  and  still  maintain  my 
**4*'  call  because  of  frequent  trips  to  the  Atlanta 
area.  The  group  which  originally  began  construc- 
tion of  the  Atlanta  repeater  consisted  of  serious 
amateurs  with  a  desire  of  promoting  the  growth 
of  FM  activity.  This  group  was  gradually  over- 
taken by  a  group  of  ex-Army  MARS  operators 
who,  atter  a  change  in  command  of  the  MARS 
group,  became  dissatisfied  with  the  Army  MARS 
FM  repeater  program.  This  group  then  used  its 
political  and  financial  contacts  to  establish  the 
Stone  Mountain  repeater.  This  group  has  never 
liked  to  have  its  inner  circle  questioned,  even 
while  affiliated  with  MARS. 

There  still  remain  a  few  stations  who  will  work 
transient  mobiles.  However,  the  control  station 
will  not  work  anyone  with  what  he  calls  a 
"Yankee  Brogue,"  which  includes  anyone  who 
does  not  come  from  the  4th  call  area.  I  have  been 
called  down  by  that  station  because  he  cannot 
understand  anything  but  deep  southern  drawl!! 
On  my  last  visit  I  made  the  statement  on  the 
repeater  that  the  Atlanta  area  was  getting  a  bad 
reputation  in  FM  circles.  This  stirred  up  some 
comments,  both  pro  and  con.  However,  it  did 
serve  to  wake  up  some  of  the  operators  in  the 
Atlanta  area,  and,  for  several  days  every  transient 
operator  was  worked  by  several  stations,  Thus^  I 
hope  that  Ken's  editorial  did  some  good. 

Glen  Zook  K9STH 

818  Brentwood  Lane 

Richardson  TX  75080 


73  MAGAZINE 


HIGH  VOLTAGE 

1  AMP  ifO«< 


PtV 

D  2000* 
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D  4000 
O  5000 

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□  10000 


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SILICON 
RECTIFIERS 


1  AMP 
800  P  IV 

SILICON 
RECTIFIERS 

ir  Avotanche  Type 
i^  Micro  Mtniafur^ 
*  Up  to  2  Amp% 


for 


3  AMP 

1000  PIV 

SILICOH 
RECTIFIERS 

4  ^or  $2 


RAYTHEON     I 
5U4  SILICON  I 

$J98 

1  AMP     5$1 

lOOOPIVfor      I 

SILICON  RECTIFIERS 


FAIRCHILD  LINEAR 
IC    AMPLIFIER  SALE 

An>f  3  -    10%  Diicountl 

D«tcripljon  Each 

Wide  Band  DC  1.49 
RF-IF  Amp  1 .25 

Operational  Amp  1 .49 
Hi-Sp«ed  Diff  I.19 
Dual  Comparator  T.49 
Freq.  Comp.  709  2.50 


6  AMP  SILICON 
FULL   WAVE  BRIDGES 


GIANT  SALE  ON  NEW  TTL 
TEXAS   &  NATIONAL   ICs 

*^/Spec  SheeH       Any  3  ^    10%  DhcoonN 


Typ# 

□  SN7400N 
n  5N7402N 
3  SN7404N 
U  Sf^74lON 
3  SH742QH 
3  SN7430N 
H  SN7440N 
U  SN7440F 
J  SN7441N 
J  SN7442N 
J    SN7447N 

n    SN7470F 

n    SN7472N 
G    SN74r3n 

n    SN7474N 

n  SN7475N 
n  SN7476N 

D  SN7483N 
n  SN7490N 
D  SN7492N 
J  SN7493N 
~2  SN749SN 
Code:   F 


I  ■«*#'A-«^«  i'-a  ■'« 


■i^iPfPi 


D«scrtptton 

Quad  2  Input  Nand  Gate  , 

Quad  2  Input  NOR  Gate  .««... 
Hex  Inverter 

Triple  3  In.  NAND  Gate  

Dual  4  In,  NAND  Gate  ,„.,„. 

8  Input  NAND  Gate 

Dual  4  In.  Nand  BUFFER 

Dual  4  In.  Nand  BUFFER 

BCD  to  DeciTnal  Driver 

BCD  to  Decimal  Decoder 

BCD  to  7-Seff. 

Decoder-Driver 

J-K  Flip  Flop  . 

J-K  Master  Slave  Flip  Flop 

Dual  J-K  Master  Slave 

Flip-Flop    

Dual  **D'*  Type  Edffe 
Triggered  Flip  Flop  ... 

4  Bit  BisUble  Latch  

Dual  J-K  Master  Slave 

Flip   Flop  - 

4  Bit  Binary  Full  Adder 
Decade  Counter 
Divide-by-twelve  Counter  .»»** 
4  Bit  Binary  (divide  by  16)  „ 
4  Bit  Right  &  Left  Register  .. 
—  Flat  Pak,  N  —  Dual  Inline 


SALE 


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1.49 
2.95 


D  lot   Catalog  on  Fiber  Optics,  MPs',  Semis,  Parts 

Terms:  mid  post;ige.  Rated:  nel  30,  cod's  2^*^/r 
Phone  Orders:  Wake/ield.  Mass.  (617)  243^3820 
RefaiU  211  Albion,  St.,  Wt^kpfieid,  Mass. 


POLY  PAKS 


P.O.  BOX  942  A 
lynnfield,  Mass. 

01940 


WORLD  QSL  BUREAU 

5200  Panama  Ave.,  Richmond  CA  USA  94804 

PLAN  I.  We  foTtvvard  yotur  Q^Lii  (please  arrange  aiphab^'ti- 
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and  to  or  wtthui  USA,  Canjjtda,  cind  M«;xico,  for  4V  euch. 

PLAN  2.  Ydu  usfr  our  ip^cuJ  t^g  form  and  send  us  a  copy. 
We  supply  QSh—mmkc  out  QSL^a^bver  QSL,  aU  for  8^  each. 


HHb 


EVICES 


Hot  C«rTii*  Diodn:  HP^8O0 90i.    12/SlO.OO     Maichnd  by  HAI 4/M.^5 

ICj:  f  ^  L  900.  914.  .„  , 60^  f  ^  L  923 90^ 

MRTU  MC790P.  MCS90P S2.00,    10/$19,50 

MC734P.  MC7e9P.  MC792P,  MC7Z5P Si  05.  10/S9.50 

AlsoA^aMabler   MC7g8P,  MCS80P.  MC7e7P,  MC97^P 
OP  AMf^    SH72713m  (DlPl.  SN7270eL  itOBJ  . . .  $1.B0.  7/SlO.OCi 

TOROJOS;  Indiina  OBfwnlCF  102-06,  CF  102^1.  Cf10t<»2 Gtk 

CINCH  iCiCH*iti,14^Dir.riCS. Md  HAL  DEVICES 

AfM  Poftagt,  wnd  for  aim(ti«t«  iret.  Box  365  L.  Urbana,  Illinois  61601 


PROFESSIONAL  REPAIR  AND  CALIBRATION  SERVICE 

SpeciaJut  in  the  maintenance  and  calibration  of  school 'i  electfonic 
-laboratory  ffquipmentp  teit  equipment  and  amateur  equipment  Prompt 
fenricf  by  holders  of  amateur  and  commercial  FCC  Licenses.  Wri(e  for 
shipping  inttmctions. 

PANTRONICS  OF  VIRGINIA,  INC- 

&e08  Ed»li  Rd, 

Alexandria,  Virginia  22312 


VHF-UHF 

CRYSTAL  CONTROLLED 
CONVERTERS 
Model  432CA  —  *64<S5 -^ 


•  Silicon 
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Available    for    50    through    432    MHz 
FET  Clrcuftrv  •  Silver  Plated  Circuits 
ac     Pouver    Supply  *  Wfite     for    detailed     Data 
I A  (U  F  I     Shirats  or  order  direct,  fpecrfying  i-f  frequency. 

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LABORATORIES  teiephon*  ?a  1584^521  1 


LARGEST  ASSORTMENT  of 
BRAND  NAMES 

You  can  save  enormous  amounts  of  money 
while  choosing  from  a  complete  fine  of  trans- 
ceivers, receivers,  transmitters,  etc, 
WE  HAVE  EVERYTHING  IN  HAM  GEAR 

SAVE  MONEY  ORDER  BY  MAIL 
CB  Radio  Co,,  Inc.  se  Aspen  Rd. 

Swampscott,  Mass.  01901 617-598  97 QQ 


l^l^^  CONTROL  CENTER 

FOR  SWirCHlHG  SYSTEMS  IN  PUT /OUTPUT 


3-ChitnneIat  Vs0,  push 
switches  to  aeiftit  TV 
camernst  monitors,  RF 
antenna  systems.  "M" 
type  connectors  on 
reur  side.  No  impe* 
diiLnce  worries^  Mitny 
audio  model*  too. 
LawrenceV  Ma.  0i842S>i*PP^d      postpaid. 


A I    m^''^^^'  ^"^  134SS 


WE  PAY  HIGHEST  CASH  PRICE 

for  Electron  Tubes  &  Semiconductors 

Immediate  Payment  on  Unused  Tubes 

H  &  L  ASSOCIATES 

Elizab^thport  Industrial  Park 

Elizabeth,  New  Jersey  07206 

(201)  351  4200 


VibropleX 


ENJOY  lASY, 
RESTFUL  KEYING 

$21 .95  fo  $43.95 
THt  VfBltOPLEX 

CO..    INC, 
833  Broadway, 
New  York,  NY  10003 


DECEMBER    1970 


127 


h 


No  on©  likes  to  go  into  a  store  without 
buying  somethmg,  right?  It  Is  the  same  with 
these  information  requests.  You  will  be 
*ixpected  to  buy  something.  Oh,  it  doesn't  have 
to  be  a  $50,000  antenna  system,  but  It  should 
be  something  modest ...  a  transceiver  •  •  .  a 
linear  .  ,  ,  you  know-  Ws'll  leave  the  decision  up 
to  you,  knowing  that  we  can  trust  you  to  do 
the  right  thtng. 

And  we  are  definitely  not  saying  that  the 
use  of  this  service  coupon  has  any  curative 
powers,  but  we  cannot  but  notice  that  many 
readers  report  remarkable  relief  from  simple 
backache,  headaches,  lumbago^  and  acid 
indigestion  after  sending  in  their  coupon.  Why 
take  any  chances? 

AOVERTISEfl  INDEX 


J  Adirondack    93 

Perfection  Products   68 

Arco    127 

Poly  Palti    127 

AmateLir  Electronic  37 

t  J 

Regency   53 

«  .'  Antenna  Labs  116 

a 

Ross  a  Whrte   55 

a  Antennas  Inc.   32 

p 

BP  Electronics  79 

LI  ATV    119 

□ 

R&R    70 

o  saw  29 

a 

Sams   21 

=  Calibook    78,99,121 

O  Stones  aSL    12B 

M  CB  Radio    127 

r 

Sentry    35 

Cfvstck   78 

1 

Signal  One   49 

D^Kl  122 

u 

Siep   67 

n  Delta  126 

n 

Spectronics  64 

i  '  Dow  Trading   12& 

o 

Standard    58.  59 

n  Drgke    IV 

□ 

Swan    \  1 

1  J  EKV  Video  Vision    126 

II 

Telecom    60 

LJ  Electra    89 

n 

Telre>t    71 

O  Epsilon  119 

D 

Tower    124 

O  Flammgo   90 

n 

Tristao    120 

DFreck    115 

u 

Two  Way    123 

Gateway    123 

n 

unique  Products   93 

1  1  GgfG    69 

I.; 

Vanguard    50,  118 

11  Goodheart  125 

n 

Varitronics   56,  57 

M  Gordon    72 

n 

Vibroplt!i<    127 

;  Gregory    G5 

i 

World  QSL    127 

!  Hal    127 

U  73  Stuff 

Mallicrafters  2B 

Gunsmoke   36 

Ham  Buerger    38 

FM  Anthology    41 

Hatry    91 

Spec  SheetB  55 

1.!  Heath    15 

73  Subscriptions   63 

t:i  Henry    13,61 

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73  Reader  Service  Coupon  \ 

Now  w«  dort't  say  that  every  single  reader 
must  buy  every  last  product  advertised  m  73. 
W©  believe  that,  but  we  don't  say  it.  The  very 
feast  every  reader  can  do  is  to  put  on  a  show  of 
interest  in  the  products  herem  advertised.  To 
make  this  a  simple  task,  even  for  ttie  faziest 
reader  (now  there  Is  a  contest  for  you!),  we 
have  cF overly  arranged  the  advertising  index  to 
double  &%  a  readers  service  coupon.  AH  you 
have  to  do  is  tear  it  out  ^or  photocopy  it)  and 
send  it  in  with  the  appropriate  boxes  marked. 
(We  have  a  prize  for  the  most  boxes  marked 
,  .  ,  a  silent  prayer  of  thanks  from  the  pub- 
lisherK  WeMl  accept  postcards,  slips  of  paper,  or 
I  almost  anything  else  that  lists  the  companies 
*    you  want  to  hear  from  and  your  address. 


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128 


73  MAGAZINE 


Here's  a  transceiver  designed  for  the  amateur 
who  would  rather  spend  his  hard-earned  radio 
dotlar  on  performance  than  frills.  The 
NCX-1000  is  built  to  meet  the  demands  of  the 
operator  who  needs  and  desires  a  high  perfor- 
mance SSB-AM-CW-FSK  rig  with  solid-state 
dependability  and  plenty  of  power.  Add  to  this 
the  convenience  of  having  your  transmitter 
{including  linear  amplifier),  receiver,  power 
supply,  and  monitor  speaker  in  a  single,  com- 
pact, smartty  styled  59  pound  package. 

So  let's  look  at  the  NCX-1000,  starting  with 
the  double-conversion,  solid  state  receiver. 
After  the  received  signal  is  processed  by  a 
doubie-tuned  preselector,  a  stage  of  RF  amplifi- 
cation, and  another  preselector,  it  is  applied  to 
the  first  mixer  for  conversion  to  the  first  IF 
frequency.  The  first  IF  contains  passband  filters 
and  a  stage  of  amplification.  A  second  mixer 
then  converts  the  signat  to  the  second  IF 
frequency  for  additional  processing  by  a  6- pole 
crystaMattice  filter  and  four  IF  stages.  Finally, 
the  signal  is  detected  and  amplified  by  four 
audio  stages.  The  unparalleled  high  dynamic 
range  lets  you  tune  in  weak  stations  surrounded 


by  strong  interfering  signals.  The  result?  High 
performance  for  SSB,  AM,  CW,  and  FSK. 
Sensitivity  of  0,5  EMF  microvolt  {for  a  10  db 
S  +  N/N  ratio). 

In  the  transmitter  you'll  find  three  stages  of 
speech  amplification  followed  by  a  balanced 
modulator,  a  crystal-lattice  fitter,  a  filter  ampli- 
fier, and  an  IF  speech  processor  {clipper).  A 
mixer  converts  the  signal  to  a  first  IF  frequency 
for  processing  by  two  crystal  passband  filters, 
and  two  IF  amplifiers,  A  second  mixer  converts 
the  signal  to  the  transmitting  frequency  where 
It  is  amplified  in  five  RF  stages  before  it  gets  to 
the  grid  of  the  6BM6  driver.  Final  power 
amplification  takes  place  in  a  forced^air-cooled 
8122  ceramic  tetrode  which  feeds  the  antenna 
through  a  pi  network-  Other  features?  You  bet! 
Grid  block  keying  for  CW.  Complete  metering. 
Amplified  automatic  level  control  (AALC). 

So  here's  a  package  that  can  give  you  1000 
watts  PEP  input  on  80  through  10  meters,  1000 
watts  on  CW,  and  500  watts  for  AM  and  FSK„ 
The  speech  processor  lets  you  double  your  SSB 
average  power  output  with  minimum  distor- 
tion.   No  frills  with   the  NCX-1000.   Just   top 


performance. 

For  complete  (and  impressive)  specifications  and  details,  writei 

NATIONAL  RADIO  COMPANY,  INC. 

MwF€%^M      111  Washington  Street,   Melrose,  Mass.   02176   (617-662-7700) 


At  last— Drake  quality  in  a 

* 

VHF  FM  Transceiver 


Marker 
Luxury 


f/ 


The  best  of  the  Japanese,  the  Marker  Luxury  VHF  FM  Transceiver 
is  built  for  and  distributed  and  backed  by  the  R.  L.  Drake  Co. 

mclLdes  transceiver, 
two  channels  supplied, 
I         hH^    ^fm  mobile  mount,  microphone, 


•  Exceptional  receiver 

•  Backed  by  R.  L.  Drake 

•  Complete  package  for  .*. . 


e      ^ 


329 


95 


coax  cable  and  antenna. 


General 

Frequency  Coverage     144-148  MHz 


SPECIFICATIONS 

Transmitter 


Humher  of  Channels 


Modulation 
Transmitter  Control 
Power  Drain 


Power  Source 


Dimensions 
Weight 


12  Channels,  2  supplied 

Channel  1 
Receive  146,94  MHz 
Transmit  146.34  MHz 

Channel  2 
Simplex  146J4  MHz 

Frequency  Modulation 

Push-to-Talk 

AC:  Receive  6  Watts 
Transmit  50  Watts 

DC:  Receive  0.5  Amps 
Transmit  4  Amps 

AC:  117  Volts  Factory  Wired 
220/240  Volts  50-60  Hz 

DC:  13.5  Volts  ±10%. 
7%"  W  X  2W  H  X  10y4"  D. 
m  lbs. 


RF  Output  Power 
Frequency  Deviation 
Frequency  Stability 
Spurious  Radiation 


10  Watts 

15  KHz  maximum 

±.001%  or  less 

Greater  than  —80  dB  below 
Carrier 


Frequency  Multiplication  12 


Input  Impedance 
Sensitivity 


Standard  Accessories  Dynamic  Microphone, 

Antenna,  Connector  Plug, 
AC/ DC  Cord 


Receiver  ,  i. 

Receiver  Circuit  Crystal-controHed  Double 

Conversion  Superheterodyne 

Intermediate  Frequencies  1st  107  MHz,  Znd  455  kHz 

50  to  75  Ohms 

0,5  >iV  or  less  for 
20dBS+N/N  ratio 

1  >uV  or  less  (30  dB  S+N/N 
ratio  at  10  kHz  deviation 
with  1  kHz  modulation) 

Greater  than  80  dB 

At  40  kHz  separation 

,  Greater  than  -80  dB  0.5 
Watt  with  10%  or  less 
distortion. 


Intermodutation 
Spurious  Sensitivity 
Audio  Output 


See  at  your  distributor,  or  write  for  details..  Jl 

R.  L.  ORAKE    COMPANY 

540  RICHARD  ST.,  MIAMtSBURG,  OHIO  45342