amateur radio - The Life of Kenneth

TELEVISION
In This Issue
-
"SIGHT EFFECTS"
SEE
PAGE
710
Frequency Modulated Receiver
What
is the Rhumbatron?
Television Course
International Radio Review
All -Wave
8 -tube
Receiver
Universal Test Meter
Radio Test Quiz
25
IN U.S
AND
CANADA
HUGO
GERNSBACK
EDITOR
RADIO EXPERIMENTING
AMATEUR RADIO
APRIL
1939
R,gDlO
AMATEUR
COURSE,.
/All
Prominent
Ready to Show You This Big Book!
ARIZONA
Sam's Cigar Store.
127 N. First Ave.. Phoeniz.
344
Radio Co.,
Fourth Street, Long Beach.
Wholesale
E.
Electric Co.. Ltd..
Market Street, San Francisco.
Offenbach
1452
Zack Radio
Supply
Co..
Market Street. San Francisco.
1426
Auto Equipment Co.,
Nth at Lawrence. Denver.
CONNECTICUT
Radio Inspection Service Co..
2'1 Asylum Street. Hartford.
Stern Wholesale Parts. Inc.,
210 Chapel St., Hartford.
Radio Service Co., Inc..
W. Peachtree St., N. W.. Atlanta.
930
ILLINOIS
Allied Radio Corporation.
823 West Jackson Blvd.. Chicago.
Newark Electric Company,
W. Madison Street,
226
INDIANA
Van Sickle Radio. Inc..
West Ohio Street,
Indianapolis.
MASSACHUSETTS
RADIO AMATEUR COURSE
NOT REPRESENT THE GREATEST
BOOK VALUE EVER OFFERED TO THE RADIO
DOES
"FANS"
FOR
SOC
TO convince you that there isn't a better
book buy today, the publishers of the
RADIO AMATEUR COURSE make the sensational offer of a money-back guarantee on such
a low-priced book. Stop in at any of the many
dealers listed at the right and examine this
volume. See for yourself if the RADIO AMATEUR COURSE isn't just the book you've always wanted.
Printed on the finest quality paper -well illustrated attractive 4-color cover-complete
with radio information you must have. It contains a step -by-step program for obtaining a
short -wave radio education.
Written by George W. Shuart, W2AMN,
foremost short-wave authority
148
PAGES
6' 9'
x
INCHES
OVER 150 RADIO DIAGRAMS
and TECHNICAL PHOTOGRAPHS
t' eater Boston Distributors,
40 Waltham St.. Boston.
H. Jappe Co., 46 t urnhili, Boston.
Wholesale Radio Service Co.. Inc.
110 Federal Street. Boston.
Springfield Radio Co..
397 Dwight Street, Springfield
R. Jappe Co.,
Mechanic
37
Street. Worcester.
MICHIGAN
Rtsst Brothers. Inc..
5027 Hamilton Ave.. Detroit.
MISSOURI
Modern Radio Company,
409 No. Third Street. Hannibal.
Burstein- ADplebee Co..
1012 -14 McGee Street. Kansas City.
Van Sickle Radio Co..
1113 Pine Street. St. ]outs.
NEBRASKA
Itadio Accessories t onmany,
Farm= Street. Omaha.
2366
NEW JERSEY
Arco Radio Co.,
227 Central Avenue, Newark.
Wholesale Radio Service Co., Inc..
219 Central Avenue, Newark.
NEW YORK
Wholesale Radio Service Co.. Inc.
542 E. Fordham Rd., Bronx.
t \' holesale Radio Service Co.. Inc.,
90 -08 166th Street, Jamaica, L. L
Elan, The Radio Man. Inc.,
64 Dey Street. New York City.
Eagle Radio C
89 Cortlandt Street. New York City.
Federated Purchaser. Inc.,
25 Park Place, New York City.
Ilarrison Radio Co..
12 West Broadway. New York City.
Sun Radio l'o..
212 Fulton Street. New York City.
Terminal Radio Corp..
80 Cortlandt Street, New York City.
Thor Radio Corp..
60 Dey St.. New York City.
Try -Mo Radio Co.. Inc.,
95 Cortlandt Street. New York City
%VbOIesaie Radio Service Co.. Inc.,
100 Sixth Avenue, New York City.
Radio l'arts & Equipment t'o..
244 Clinton Avenue No.. Rochester.
M. Schwartz & Son.
710 -712 Broadway. Schenectady.
If
We
Main Street. Akron.
Canton Radio & Supply Co.,
1140 Tuscarawas Street. W., Canton.
United Radio. Inc.,
1103 Vine Street, Cincinnati.
The Ilughes- Peters Electric Corp..
178 -180 N. Third Street. Columbus.
Standard Radio Parts Co..
135 East Second Street. Dayton.
51
So.
OREGON
Portland Radio Supply Co..
1300 W. Burnside Street. Portland.
PENNSYLVANIA
Radio Distributing Co.,
1124 -26 Market Street. Harrisburg.
AI. & Il. Sporting Goods Co.,
512 Market Street, Philadelphia.
Camera,'; lo Co..
963 Liberty Are., Pitt,bucm.
Chicago.
Wholesale Radio Sen ice Co.. Inc.,
001 W. Jackson Blvd.. Chicago.
34
OHIO
News Exchange.
GEORGIA
R'holeeale
IF THE
NEW HAMPSHIRE
Radio Service Laboratory,
1187 Elm Street, Manchester.
CALIFORNIA
Scott
COLORADO
Your Money Back
DEALERS
RADIO
RHODE ISLAND
W. IL Edwards t'o..
32 Broadway, Providence, R.
I.
TEXAS
Amarillo Electric Co..
111
East 8th Avenue, Amarillo.
UTAH
O'Loughlin's Wholesale Radio Supply.
915 South Main Street. Salt Lake City.
Radio Supply. Inc.
46 Exchange Place,
Salt Lake City.
WASHINGTON
Spokane Radio Co.. Inc..
611 First Avenue. Spokane.
WISCONSIN
Radio Parts Co.. Inc..
State Street. MBwaukr,..
538 -538 W.
AUSTRAUA
McGill's agency.
188 -184 Elizabeth Street. Melbourne.
CANADA
Eaton Co.. Ltd..
Winnipeg, Manitoba.
Canadian Electrical Supply Co.. Limited.
The T.
Craig Street W.. Montreal, Que.
Metropolitan News Agency.
1248 Peel Street, Montreal, Que.
285
CUBA
The Diamond Ness, Co..
Palacio Asturian, roc San Jose.
Habana.
ENGLAND
Gorringe s American
9a,
News
Green Street, Leicester
Agency,
Square,
W.C.2.
London.
HOLLAND
Van 1Vorst :sat. Amster-
Radio Poeten,
dam. Z.
INDIA
Empire Rook Mart.
Box 631,
Bombay.
MEXICO
American Book Store. S. A.,
Avenida Madero 25. Mexico City.
Central De Publicaciones.
Avenida Juarez. 4. Apartado 2430.
Mexico, D. F.
NEW
ZEALAND
Te Aro Rook Depot. Ltd..
64 Courtenay ¡'lace. Wellington.
SOUTH AFRICA
Technical Book Co.
147 Longmarket Street. Cape Town.
this book is not at your dealer's, send your order directly to us.
will credit your dealer with the sale of this book. To order your
of RADIO AMATEUR COURSE, fill in coupon below and
mail/
r
RADIO AND TELEVISION, 99 Hudson St., New York, N. Y.
Gentlemen: I enclose herewith my remittance of Fifty Cents
(50c) for which please send me POSTPAID, my copy of the
RADIO AMATEUR COURSE. (Remit by check or money
order : register letter if you send cash or unused U. S. Postage
Stamps.)
RADIO AND TELEVISION
Name
99 Hudson Street,
Address
New York, N. Y.
City
State
R &T -439
1'LI- TRY, MARY,
BILL, YOU'RE ALWAYS
FOOLING WITH
OUR SET WON'T
WILL
WORK
You FIX IT
-
RADIO- -
I'LL TAKE IT
HOME. TONIGHT
'Ì
-
FIND OUT
I CAN'T
BILL-
-HELLO,
GOT A
ONE
-TOUGH
WHAT'S WRONG
GUESS I'LL MAKE A
TOOL OF
MYSELF
WITH MARY
HELLO JOE- WHERE'VE
YOU BEEN LATELY-'
AND WHERE DID YOU
'f0 TIX?
1_ARN
LET ME
HELP YOU
OUGHT TO TAKE THEIR,COURSE. IVE GOT
A
A GOOD RADIO J08 NOW. LETS MAKE
WITH
CIRCUIT DISTURBANCE TEST .-STARTING
(
THE AUDIO OUTPUT STAGE
AND TESTING EVERY STAGE
ems/
'RIGHT BACK TO THE
-%
C
LESSON WI-IIGH THE
'RADIO INSTITUTE
NATIONAL R
'FREE
f
-,
X
i
/71.
1
'/
\(
HOME- -I'LL
MAIL THEIR
COUPON RIGHT
AWAY
SENDS YOU WHEN
YOU MAIL A
lM
'PRACTICAL AND
COURSE
COMPLETE. I'LL ENROLL NOW
`ANO THEN
CAN
MAKE
FIXING
ANTENNA. LISTEN FOR
THE CLICKS WHEN I
TAP THE GRID LEADS
WITH
A
J
AVIATION RADIO, POLICE
RADIO, TELEVISION,
ELECTRONIC CONTROLS RADIO IS SURELY GOING
OR GET A JOB
RADIO
BROADCASTING OR
AND THE
NATIONAL RADIO
'PLACES.
TRANSMITTING
STATION
INSTITUTE HAS TRAINED
HUNDREDS OF MEN
FOR JOBS IN RADIO
RADIO SETS
1
COUPON =ROM
I
'REAL MONEY
OR INSTALL AND SERVICE
LOUD SPEAKER SYSTEMS
ONE OF THEIR ADS
ç
CONVINCED NOW THAT THIS
15
\
SAY- WHERE
DID YOU LEARN
THAT TEST? ITS
A GOOD ONE
YOU
WITH THE NATIONAL RADIO INSTITUTE.
ANYTHING
I'VE SEEN THEIR ADS
NEVER THOUGHT I
BUT
COULD LEARN RADIO AT
I
IVE BEEN STUDYING RADIO AT HOME, ß11L,
ABOUT
RADIO ?
HERES THE TROUBLE,81LL, IN THE
FIRST I.F. AMPLIFICATION STAGE. I
LEARNED THAT TEST EVEN BEFORE
I STARTED TAKING THE COURSE,
rá111. IT'S 'DESCRIBED IN Pi
//
./
It
1
-
I
a Lesson on
will send you
IT CERTAINLY IS
EASY TO LEARN RADIO THE
ONLY
N -R1. WAY. I STARTED
A FEW MONTHS ASO. ANO I'M
MONEY.
GOOD
ALREADY MAKING
THANKS:
Too GEiTAINIt KNOW
noto. SOunOS AS
GOOD AS THE DAY
I OOUGHT IT.
s-
INN SPARE TIME
WORK IS GREAT
Radio Servicing Tips FREE
FUN AND
'PRETTY SOON
TILL BE READY
TO SHOW HOW PRACTICAL IT IS
TOR A FULL
TIME JOB
TO TRAIN AT HOME FOR
IN RADIO
GOOD JOBS
SMITH
J. E.
circuits. This 50 510 method of training
Clip the coupon and mail it. I will build
President
learning at home Interesting. faschtaprove I can train you at home in your makes
Institute
I drvole mole than 10 Lesson National Radio
tiug,
practical.
spare time to be a RADIO EXPERT. Texts exclusively to Television n elhods and
Established 25 years
FREE.
fundalesson
Television
I will send you my first
applications. and coser
Ito has din- cued
e
Examine it, read it, see how clear and mentals thoroughly In my Course.
it for thef
more
easy it is to understand -how practical
Indtotry
Radio
than anyone else.
make learning Radio nt home. Men
1
I Also Give
without Radio or electrical knowledge
become Radio Experts, earn more
You This
money than ever as a result of my
Professional
training.
Servicing
Why Many Radio Experts Make
530, 550, 575 a Week
I nstru ment
-
Radio broadcast log stations employ engineers.
operators. station ttanagei s and pa) wall rot
trained men. Fixing Radio sets In spare
time pays many $200 to 5300 is year -full
time jobs with Radin jobbers. ntanufa'tllrers
$7.0.
sl.
$30.
or pan.
week. Many Radio Experts open full
time Radio sales and repair businesses. lin
dio manufacturers and jobbers employ tesservice
agi n
ers. Inspectors. foremen.
-'
men. In good -pay jobs with np ers.
Automobile, police, arias Pott.
advancement_
commercial Radio. hind speaker systems are
newer fields offering giskl peon unit les fins
and for the future. Television promises to
open toaty
e
er
jobs In these
have
Rad h. they got their "by. \tail cu,opon.
and
dealers
,
o'
as
much
godlj
as
to.
t Iruint
1
Many Make 55, 510, 515 a Week Extra
in Spare Time While Learning
sling Extra
The day yeti enroll I st.lrt
Money loll Sheets: Awn- yen h an tu do
Radio repair jobs. Throughout your training
I send plans and directions that made good
pare time money -$22011 to $31111 -for penend you special
shile 'learning.
d red
Radio equipment to conduct experiments and
1
OUR WORRIES ARE OVER
OH GILL- I'M SO
ASKED YOU
GLAD
TO FIX OUR RADIO.
11 001 YOU STARTED
I
1
NAVE A GOOD JOB
NOW, AND
FOR US
THINKING ABOUT
NOW
YOU RE
GOING AHEAD
SO
FAST
IN
RADIO
RADIO AS A CAREER,
AND
THERE'S A
BIG FUTURE AHEAD
n
sery Radio expert
is the instrument
All -Wavy all - Purpose,
needs and scants
Set Sers Icing Instrument. It contains e' ry-
Here
-an
measure
necessary
test) tubes, resistvoilages and current
ance: adjust and align an set. old or new.
It satisfies your needs for professional servicing after )'ou graduate eon help you malt,
nLlir t.auun...
exila money fixing
.:,
Get Sample Lesson and 64 page Book
Mail Coupon
FREE
I will
in. >:nnp',. i.eswn Rewards
addition
'Rich
my e..t -naine ....d.
FREE' t,, anyone over
R:ubn'' III
nR:ullo's
old. My hook Ibn in is nut
.
and lull time oM+nrtunit le'. amt
hi Telev lslon: tolls bunt m
iIiaxe cu Teing
shows yoi,
Training ln Radio and Television:
'bal
i trained. telling Money
levers from
they
ber are deeiner ad earning: shows
In
end
aq
SMITE. PRESIDENT. DP:I "r. 911103
NATIONAL RADIO INSTITUTE. WASHINGTON, D.
J.
E.
I
Ìn
16
:
+
`elope.
COUPON
iir t.paste1A`r. TIT' enyl
caul.
J. E. Smith, Pres., National Radio Institute
C.
lesson and your free
Dear Mr. Smith: Without obligation. send me a sample
and
hook shieh points out spare time alti full tinte Radio opportunities.
lime -about the N.R.I.
-bows how I can train for them at hume in spare
write
(Please
plainly.)
you
give.
Instrument
Set Servicing
Age
Name
Address
State
Cit it
14X
-I
Dept. IDB3, Washington, D. C.
Please
tat
.
S..
_'1N
705
RADIO
./le
& TELEVISION
FLASH!
Television
y/2.T11/417 ,i,,,,i;t. _1/ 1,,,,,,,,,,'
,
Sight
HUGO GERNSBACK, Editor
H. WINFIELD SECOR, Manag. Editor
-
APRIL
Vol. IX
1939
ROBERT EICHBERG, Assoc. Editor
pri_,' -1t1
"ice.
No. 12
Jn
/Lt[s
J9luQ
GENERAL FEATURES
CONSTRUCTION
Antennas-Past, Present and Future -Harold H. Beverage, Chief Research Engineer, RCA Communications 709
Television "Sight Effects "
What
Is
a
-H.
W. Secor
710
Rhumbatron?
712
International Radio Review..
.
713
715
715
715
716
717
718
718
718
718
718
INSTRUCTION
Electronic Television Course
Henry Townsend.
Question Box
-
719
724
725
740
TELEVISION
Television "Sight Effects'
Television's Interference Problem
710
713
8-Tube
731
713
Doublets..
716
vision
Separating Video and Audio Signals 717
Television Course
..
7
to 2306 Meters
736
738
742
/vaxt Month
725
Deluxe Transmitter -"Beam Power 3"
-H. G. McEntee, W2FHP
MISCELLANEOUS
The Rhumbatron
The Martian Flash -"Fips
712
A High Efficiency 6L6 Exciter-Harry
D. Hooton, W8KPX
720
722
An
Re-
Gernsback
Ultra -High Freq. Antennas
What Do YOU Think?
Elementary Radio Lessons
World Short Wave Stations
"Let's Listen In" with Joe Miller
Tenth Silver Trophy Award for
Best "Ham" Station Photo
Radio Kinks
Question Box
New Ham Licenses
I Cover the Pacific Coast
New Radio Apparatus
Short Wave League-"On the
"Ham Bands " -Elmcr R. Fuller
723
724
726
727
706
4 -Tube
Receiver
-
Remote Control Unit for
Your Receiver
W. Palmer, E.E.
Push- Button
-C.
A 2.5,
741
How To Build A Television
5
and
10
verter- Herman
Meter U.S.W. ConYellin, W2AJL
Receiver
744
755
764
Published by Popular Book Corporation. Publication OMce -29 Worthington St.. Springfield. Maas. Editorial and
Executive Offices- 99 Hudson St., New York. N.Y. HUGO GERNSBACK. President: TT. W. SF.COR, Vice- President;
EMIT. GROSSMAN. Director of Advertising. European Agents: Atlas Publishing and Distributing Co., Ltd., 1R Bride
Lane. Fleet St.. London, England; Brentano's- Landon and Paris. Australian Agents: McGill's Agency. 179 Elizabeth
St., Melbourne.
by H. Gernsback
Exceptional
Francis J. Bauer
727
733
740
RADIO & TELEVISION Published monthly on the tenth of the month. Entered as second -class matter Feb. 15.
1938, at the post office at Springfield. Mass., under the act of March 3, 1879. Trademarks and copyrights by
permission of D, Gernsback. Text and illustrations are copyright and may not be reproduced without
permission. Subscription price $2.50 a year in the United States and possessions and Canada, $3.00 in foreign countries. Make all
subscription checks payable to Popular Book Corporation.
1939
734
Receiver -Range
-Herman Yellin, W2AJL
Universal Test Meter, 2500 Volt Range
A New Communications Receiver- McMurdo Silver
Cover composition by H. Gernsback and Thomas D. Pentz.
Television "Sight Effects" staff at work. Photos courtesy N.B.C.
Copyright
731
W8KPX
General Electric Answers Television Questions
Vertical or Horizontal Tele-
turns"-H.
W2CDV
721
733
716
720
-Martin Clifford,
Receiver
-Tube 1.4 Volt Superhet for Hams and Fans -Harry D.
Hooton,
Martian Flash -H. Gernsback
CONDENSED FEATURES
6
An All -Wave
719
Radio Test -Quiz
The Radio Beginner- Lesson 6
Modulation
Ultra High Frequency Antennas
Antenna Systems for Hams
713
Radio Test -Quiz-Robert Eichberg
New York and London Mayors
Talk by Short Wave
The 50,000 Hour Tube
Fire-Fighting at the Fair..
Facsimile Reaches the Public
Vertical or Horizontal Television Doublets?
Electronic Musical Instruments
Reducing Hum in S. W. Receivers
Circuit Breakers Protect Tubes
Simple Radio Time Switch
Baffling for High Fidelity
New Pick -Up Feed
Frequency
Radio Kinks
World-Wide Radio Digest
The
Effects
Certified Circuits
When you see this seal on
a set it is a guarantee that
it has been tested and
certified in our laboratories,
as well as privately in different parts of
the country. Only constructional-ex perimental sets are certified.
You need not hesitate fo spend
money on parts because the set and
circuit are bona fide.
This is the only magazine that renders such a service.
QUICK, EASIER WAY
TriA
äELEaRI(
Practical WORK
1Z Weeks
CHICAGO SÑOPS
THEN -You do the job yourself.
FIRST -You are told and shown how to do it.
TO EARN MORE MONEY?
WANT
you ever dreamed
Have
of
world's Electrical Center, you can
in
get 12 weeks' Shop Trainingyou
ELECTRICITY, that can help give
your start towards a better job.
-
you
you
work
the
ding
of
ever dreamed
really like in a job that holds promise
of a real future in the years ahead ?
Well, we all know that you can't get
dreamthe good things in life by ofjustfellows
are
fng about them. Hundreds
a
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01213.
o0eo
troRNG
"2egr th
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will be trained on actual equip
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today holding down mighty fine jobs
prospects of a bright future. They are filling
to
these jobs because they had the foresight
of
equip themselves with the right kindaveronly
training. Most of these men were the
proper
age fellows a short time ago, but
pay
training helped to lift them out of the low
ranks of unskilled workers. The same opportunity is now offered to you. ELECTRICITY
The great fascinating field of
offers a real future to many men and young
to prepare for a place in
men who are
this giant industry.
You
method
ment and machinery and because of our expertof training, you don't need previous of my
ence or a lot of education. Many
successful graduates never even completed
Grammar School.
Here in my school you work on generators,
motors, dynamos ,youdo house wiring,windarmatures and do actual work in many other branches
of electricity and right now I'm including valuable
instruction in Diesel, Electric Refrigeration
cost. Our
and Air Conditioning at no extrato
practical shop methods make it easier learn
First the instructors tell you how a thing should
done -then you do the actual work yourself.
-
YOUR TRAINING
I'LL FINANCE
it
-then
monthly
after
months
- then
it
start
pay for
You can get this training first
payments, starting 60
later in easy
is
days after your 12 weeks' trainingto period
complete
you have 12
over
your payments.
If you need part time work to help out with
expenses while training in my shops, my employment department will help you get it. Then
after graduation this department will give you
valuable lifetime employment service.
Send the coupon today for all details.
When I get it I'll send you my big free book
containing dozens of pictures of students at work
H. C. LEWIS, President
CO(NESt.,
500 S. Paulina
ELECTRICAL
Dept
19
-51,
Chicago
in my shops. I'll also tell you about my "Pay
earn while
After Graduation "plan, how many we
help our
learning and how
graduation.
students
Fill in, clip coupon, mail
toward
today for your
a brighter future.
H. C. LEWIS, President
COYNE FLECTRIGAL SCHOOL
500 South Paulina Street, Dept.
4941,
Chicago, Ill.
of your
Dear Sir: Please send me free your big catalog and full particulars
present offer, also your "Pay- Tuition- After-Graduation" Plan.
NAME
ADDRESS
CITY
Please say you saw if in RADIO
STATE
&
TELEVISION
707
....THESE
ARE
OUTSTANDING SHORT WAVE BOOKS
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AT YOUR DEALER!
YOU buy parts. tubes, kits, accessories from your local radio dealer
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Compiled by the Editors of
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101
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LOOK FOR YOUR NEAREST DEALER
For convenience the publishers list below dealers in all parts of the world where our
books are available. On your next shopping trip be certain
to examine these volumes.
You're sure to want them for your technical
library.
ARIZONA
Sam'ss Cigar Store. Phoenix
CALIFORNIA
Electric Supply Co.. Oakland
Radio u ply Company. Los Angeles
Radio
Television Supply Co. Los Anl'acific'Radio Exchan Re, Inc., Los An
geler
Western Auto Supply. Los Angeles
tack Radio Supply Co. Los Angeles
roman' Book 'tore Pasadena
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n Francisco
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Supply
ranciac0
Specialti) Co.. Sana Jo
Elec.
COLORADO
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Equipment co..
Interstate Radio Supply. Denver
o
CONNECTICUT
The Edward P. Judd Co.. New Haven
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Wilmington Elec. Spec. Co., Inc., Wilmington
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Radio Accessories Co.. Orlando
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w'holesate Radio Service Co.. Inc..
Atlanta
ILLINOIS
Radio Corpnratlon, Chicago
Allied
'alter C. Braun, Inc., Chicago
Chicago Radio Aspanlus
Co.. Chicago
`x. C. McClure-- & Co.. Chicago
Midwest Radio Mart, Chicago
Newark Electric Co.. Chi
Chicago
a
Mare. Roebuck
o
Chicago
Co.. Chicago
Radio Service
Inc.. Chi
cago
eae
Chiaag
rrvo
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Co..
he
Personal
Rado Service Co Ic.. Bosn
Bonk House. Springfield
Tremont icier. Supply Co.. Boston
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Rissi Brothers. Detroit
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St. Paul Booked
St. Paul
Co.. Kansas
RursteinAppiebee
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Radio
alter ) Ashe Radio CO.
Louis
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NEW JERSEY
A pparatus Cn. New ark
ltd Radio
ewark
Wholesale Radio
o.. Service Co..
ewrk
J. K. Gilt Co.,
Radio reefers, Amsterdam,
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Empire Book Mart. Bombay
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Portland
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Radio Electric Sen -ice Co.. Philadelphia
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ìvSeattle Radio Supply Co., Seattle
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Spokane Radio Co.. Spokane
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Radio Parts Co., Milwaukee
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Radio Revista. Buenos Aires
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McGill's Authorized Agency. Melbourne
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Inc..
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Wholesale Radio Sery ice Co., Inc.,
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City
Harrison Radio Co., New York City
Jamaica. L. I.
American News Co.. New York City
Baker & Taylor Co.. New York Clty
Plan, the Radio Man. New York City
David Bogen
Inne.. New
Radio ircular Co.. New York CityYork
C. F... techen & Ca.. New York City
The Steiger Co., New York City
Radio Co.. New York City
Thor Radio Corp.. New
York City
TryMn Radio Co.. New York
City
Van
Riemsdyck Book
City
HOLLAND
College Book F.xrhange, Toledo
Boston
Boston
Iibury
.tores, New York
Wholesale Radio Service Co.. Inc.. New
York City
H. W. Wilson Co.. New York City
Radio Parts & Equipment Co.. Rochester
M. Schwartz &
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Publishers
Please say you saw it
T. Fatnn
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& Ca.. Winnipeg, Man.
Electrical Supplies, Ltd.. Winnipeg.
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Man.
Canadian Electrical Supply Co.. Ltd.,
Toronto. Out.
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Ont.
Canadian Electrical Supply Co., Ltd..
Moutreal, P. O.
Z.
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American Book Store. Mexico. D. F.
Central De Publicaciones. S. A., Hex.
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Te'cn1
Book Co.. Cape Tow
Central News Agency, Johannesburg
1
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IF YOUR DEALER DOES NOT CARRY
THESE BOOKS. ORDER DIRECT FROM US.
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cor which please send
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nanghai
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END
Gorringe's Amer. News Agency. London
City
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I order.
Toute La Radio. Paris
Rehr G.M.B.IH. Swan. Berlin NW No.
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C.
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in RADIO & TELEVISION
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ttains f cheek or unused I
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tt
NEW YORK, N. Y.
RADIO
&
TELEVISION
II
(I
RADIOa TELEVISION
/Bs
H. WINFIELD SECOR, MANAGING EDITOR
HUGO GERNSBACK, EDITOR
ANTENNAS
Pait, P= =gent
Harold H. Beverage
and Tutuz¢
Chief Research Engineer, R.C.A. Communications, Rirerhead, L. L, N. Y.
MARCONI. during his early work with
wireless telegraphy in 1895, used a simple dipole oscillator similar to those used
by Heinrich Hertz in his classical experiments eight years earlier. Marconi soon
discovered that he could greatly increase
the range of transmission by connecting one
side of the dipole oscillator to earth and
the other side to an elevated plate. By using
structures of greater and greater elevation to support his antenna, he found that
the range of transmission increased. Since
the wavelength emitted by this early equipment was a function of the length and size
of the antenna, it is evident that Marconi's
success quickly set a trend toward the use
of longer and longer wavelengths as well as
larger and higher antennas. When Marconi
had the famed letter "S" transmitted from
Poldhu to Newfoundland in 1901, the antenna at l'oklhu was supported by masts
about 200 feet high, and it is probable that
the wavelength was between 2000 and 3000
feet. During the next 20 years, it is not surprising that the trend toward the use of
longer
wavelengths continued, which
in
turn called for higher antennas to increase
the efficiency of radiation, and antennas of
larger area to hold the voltage down to
reasonable values when the antennas were
energized by the hundmIs of kilowatts
found necessary for reliable communication over great distances. By 1921. it was
not unusual to find some long ware transmitting antennas supported by towers 800
feet high. and other types of antennas over
a mile long. The Alexanderson multiple
tuned antenna is a familiar example of
the latter type.
During this period, the bugbear to long
distance communication was atmospheric
disturbances. more commonly known as
"static." It was found that static originated
mostly over land masses, so that, in general, on transoceanic circuits, the static
originated in a direction more or less opposite to the direction from which the signals were arriving over their ocean path.
Consequently, it was possible to greatly reduce the effects of static by using directive
reception. Numerous arrangements were
used with varying degrees of success. such
as the uni- directional "loop- vertical" combinations of Pickard. the ground wires of
A. Hoyt Taylor, and the long antennas supported on poles, such as \\reagant's antenna and the "Wave Antenna." The volt ages induced in these long antennas traveled
at nearly the velocity of light, so that very
for April,
tion of the radiated power in the desired
direction. It was logical that the first directive antennas should consist of arrays of
dipoles with reflectors. Very effective
arrays were developed as exemplified by
the British Marconi Beam antenna, the German Tannebaum antenna, and the arrays
developed in America by the A. T. & T.
Company and the RCA. These antennas.
however, were relatively expensive to construct and maintain, and as the number of
short wave circuits rapidly increased. it
was necessary to develop less expensive
types of antennas. Economical and effective antennas were devised consisting of
wires several wavelengths long orientated
in such a way as to concentrate the radiation in the desired direction. Typical antennas of this general classification which
have found wide use are the harmonic wire
antenna, the V- shaped antenna with reflector, the Rhombic antenna, and the
Marconi Series -Phase antenna. The latter
two are generally terminated in a dissipative network equivalent to their surge
impedance, so that they employ traveling
waves rather than standing waves.
The early short wave receiving antennas
were frequently arrays similar to the transmitting arrays, but less costly receiving anHarold H. Beverage, well -known for his tennas were eventually developed by the
design.
researches in antenna
operators of radio communication services.
In America, the antennas most generally
used for transoceanic services are the
long antennas could be used effectively,
Rhombic antenna and the Fishbone anthe usual length being 8 to 10 miles for
of the traveling
transoceanic wavelengths in general tenna. both of which are
the
use at that time.
The \\'ave Antenna was the first antenna
to utilize the traveling wave principle, as
distinguished from standing waves. Its
effectiveness was due in large part to its
simplicity which eliminated the critical adjustments which were required in its
predecessors which depended upon some
sort of a balancing arrangement.
The second era of long distance radio
communication started with the discovery
during the early 1920's, that short waves
below 100 meters were useful for long distance communication in the daytime, as
well as at night. For these short wavelengths, it was practical to return to the
Hertzian dipole as a radiator. It also became feasible to use directivity in the transmitting antenna to project a large propor-
Twenty -sixth of a series of
"Guest" Editorials.
wave type.
The short waves have been very useful
for studying the characteristics
of the ionosphere and the mechanism of
radio transmission in general. This knowledge has been useful in connection with
studies of propagation in the broadcasting
spectrum. The anti -fading service area of
broadcasting stations has been approximately doubled by antennas designed to
suppress the radiation at high angles above
the horizon.
We are now entering upon the third era
of radio communication, the development
of the ultra -short waves. These waves do
not ordinarily travel via the ionosphere
and are limited in their reliable range to
distances not greatly in excess of the
horizon. This quality is an advantage in
many ways since it makes it possible to
duplicate the use of these frequencies without interference at points on the order of
(Continued at page 752)
as a means
709
1939
www.americanradiohistory.com
H. W. Secor
Television "Sight
THE sight effects expert promises to
was periodically squeezed. The voice of the from top to bottom, or
bottom to top.
frog came from a loud speaker.
Some of these effects
To cause a candle to extinguish itself a lightly silvered sheetare created by using
of glass placed at
while the television camera was focused an angle so that
the first title is seen
it
upon
was a simple trick for Mr. Eddy- through the sheet of glass,
while the second
engineering staff, has already developed a he merely placed a metal
tube up the rear title is picked up as a reflected image from
number of extremely interesting sight of the candle and
when the candle was to the surface of the glass. The change from
effects for television shows. Some of these go out, a quick squeeze
on a rubber bulb, one title to the other is caused by manipueffects, such as books which turn their own connected with the metal
tube, snuffed out lating dimmers so that while one light is
pages, candles which mysteriously extin- the flame.
being slowly decreased in strength, the
guish themselves, and "talking frogs," have
In producing television plays, many cut- light behind the other
title is being gradalready been worked out and used in a backs from the
main television studio to ually increased.
number of television plays which have been the sight effects laboratory,
two floors
The leaves of a large book had to hvn
produced for experimental broadcasts dur- above, take place. In
one of the scenes, a themselves while the television camera's
ing the past few months.
eye
candle suddenly goes out -next, the tele- was focused upon the
book-this was
The accompanying piceasily accomplished by attures show some of the
taching a flexible wire
very interesting and unshaft to each page so that
usual sight effects proby turning a knob, each
duced by Mr. Eddy and
leaf could be turned by
his staff.
the operator who was
In one elaborate marine
outside the focus of the
scene built up especially
camera.
for television broadcasts,
In another scene, a pile
a tank measuring about
of books was supposed to
12 feet square was filled
fall on a bottle of acid
with water, and the telea n d upset the bottle.
viewer saw on his receivSounds simple-but suping screen a parade of
pose that this scene had
warships circling around
to be repeated several
the harbor of a small seadozen times? Here's what
port. A tugboat with a
Mr. Eddy and his staff
string of barges puffed
did. The books were
along so realistically that
guided in their fall by
the viewer would never
means of bent wires ; the
dream that this whole
bottle was secured with a
scene was being staged
hinge so that it would
with miniature ships built
always fall in the same
from cork and other odds
direction when hit by the
and ends. The ships were
falling books. The fumes
caused to move around a
from the acid in the bottle
prescribed path, thanks to
were produced by blowa circular guide track subing smoke into the bottle
merged in the water. The
Painting a miniature building for use in a Television seen e.
through a rubber tube
ships were moved by a
passing through a hole
chain fitted with coudrilled through the botplings, all driven by a motor. The puffs of viewer sees
a pair of hands fumbling with to m of the glass bottle.
smoke from the stack of the tugboat were a match. In the next
scene the candle reSeveral of the accompanying pictures
produced periodically by squeezing a rubber fuses to light-but
what
the viewer does sh ow a television miniature scene where
bulb connected to a smoke tank and a tube not know is that while
a cut -back was made th e camera moves along a street and picks
leading to the bottom of the tug's stack.
showing the hands fumbling with a match, u p images of different signs
pertaining to
The water in the harbor was colored a candle dipped in
a fire -proofing solution the dramatic story at hand. As the camera
so as to hide the mechanical devices used was substituted for
the original one.
nears the end of the street (containing, infor moving the ships. Incidentally, the water
To get the effect of a candle slowly going ci dentally, a number of cleverly
constructed
was colored by placing some dye on the out, the wick was gradually pulled
down ininiature trees and bushes), the televiewer
back of a small turtle and allowing it to inside the previously
drilled out candle.
sees a white picket fence which is used as
swim around in the "harbor."
The flight of time was one of the effects a cue or connecting link ;
next the teleAll the buildings used in these miniature that Mr. Eddy was asked
to produce and viewer sees the front of the house shown
scenes are built from wood and other ma- a photo shows how
this was
terials by Mr. Eddy and his staff, and paint- A set of progressive calendaraccomplished. in the photo. This view is picked up by a
leaves were se cond television camera, which is moved
ed in colors to suit the particular scene and
specially printed for the year in which the in slowly toward the house
until the front
locality.
scene was to take place. These leaves were door appears the same
size as does the
In one television scene it was necessary then placed on top of a frame so
that when im age of a real full sized door being viewed
to build an animated frog, and as one of a rubber roller was rotated, the leaves
slid by another television camera. A live actor,
the pictures shows, the eyes and jaws of the down a pair of bent wire guides
rapidly. su pposedly a doctor in this case, opens the
frog were caused to move by means of The television camera recorded
a flutter of door and removes letters from the mail
flexible shafts passing out through the passing dates with a very
artistic effect.
bo x. The switch -over from one television
"tail" of the frog. The stomach of the frog
A very ingenious titling machine has been ca mera to the other is done
so adroitly that
was caused to pulsate by means of a rubber devised by means of which one
title can be th e viewer never knows that in the first
bag placed inside it, this bag being con- caused to dissolve slowly into
another; in pa rt of this scene he has actually been
nected to a rubber hose and a bulb which other effects titles appear to be
"wiped off"
(Continued on page 753)
be
a mighty busy man once television ha s
become an everyday entertainment feature
-which it is scheduled to do this Spring
William C. Eddy, a member of the NBC
710
RADIO
&
TELEVISION
Effects"
-
Frogs that talk -books that turn their own pages
these and many others
spiders that "obey orders"
are produced by the television "sight effects" man.
-all
METAL
--UBE
Ru.
BEER BULB
SMCK`
POT ,___<.
GROOvEfi'\
CAROLE
¡
JET OF
i
AIR
Above -Model ships were maneuvered
around model "harbor," by means of a
moving chain. Method of pumping smoke
out of ship's stack is shown in circle.
X
METAL
TUBE
Above -How pages of a
book are turned by flexible cables, the operator
keeping out of camera
range.
Right
candle is
extinguished by squeezing
rubber bulb.
MECHANICAL
SPIDERS
RUfi EsER
BULB
CONTROLLED
`,BY CABLES
-
/
RUBBER
VOICE FROM LOUOSPEARE
JAW CONTROL
CABLE
BULB
EVE
CONTROL
Ca8Les
k
!r
rt
%r
7/
Above -Spiders that obey orders -they are
animated by means of tiny rods passing through
the hollow wires forming the "spider web."
The rods are driven by chains and pulleys.
Left -Falling calendar leaves show "flight of
time' in Television play.
RUBBER
BALLOON
Television animals not always
what they seem.
Above -animated frog in
which the eyes, mouth and
stomach more at the will
of the operator.
CAMERA
Camera (scene I) moves
from left to right and
picks up image of street
and signs along the way:
second camera is focused
on the house, Scene 2.
White picket fence is cue
for change in scene and
the canera pick -up.
;AVI ERN
Camera No. I shifts to actor in full size door, and takes up action when
door image in Scene 2 has been
"panned up" to full size.
711
www.americanradiohistory.com
Electrons "Swing It"
in
the
Rhumbatron
Waves only 10 cm. (4 inches) long may guide airplanes through use of high -power tube using new
principle of ''dancing electrons''.
thin was called by the Bureau of Air Commerce to the attention
of the
various organizations cooperating with it in the development of a blind
landing system."
Before continuing with Mr. Gilimor's discussion, pause a moment to
study the following editorial item which appeared in the M. I. T. Technology Review. This item comments upon an address given by Prof. David
L. Webster, head of the Physics Department of Stanford University,
Prof. William W. Hansen tuning the 10 cm.A,
Klystron transmitter in the Physics Laboratory at Stanford University
Varian, credited with the Rhumba invention, inspects his work, with
Russell
tron's
Prof. Hansen.
EXPLAIXIXG the Rhumbatron and
Klystron, R. E. Gillmor, president of the
Sperry Gyroscope Company, says:
"The widespread possible application of
the Rhumbatron and the Klystron in the
development of new safety devices for avisSome sketches to show whet the
trons
the
in
Klystron will
they do it!
4
i
WAVES
LANDING BEAM""
LOCATED IN
PT WITH GLASS
TOP
how
POWERFUL
" LOCATZONN
Rhumba-
do-and
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1
1
FOG
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CATHODE
VOLTAGE
SURGEN
COPPER
ANK
RESONATDRS
r
'Iwo)
-MULTIPLEX TRANSMISSION_
HIGH
ANTENNA
MANY U.
CAN
SENT THROUGH
A' GAIDY" S.-W A EO BE
EACH
CARRYING A DIFFERENT MESSAGE
IMI
IWOO" "gagreN.
ADTIOE
I
I-I
R
S
CONCENTRIC
LINE
ód_iw
--
5 METER
14" WAVES
+1
4 -60 WATT LAMPS
LIGHTED ON 4 INCH
NELD
OCO.) WAVES,WHEN
I
TUNER
1
=
NEAR1NSATRE.
'
ANTENNA
REFLECTOR
-
--
WAVE LENGTH
3.9" OA
NNW,
to ce. (3.9 ") ANTENNA
a
712
to.,
6 DEGREE
BEAM
I
INCHES
before a recent colloquium of M. I. T.'s Department of Electrical
Engineering. and says in part :
What is a Rhumbatron? "In the Klvstron a beam of electrons
representing a constant current is sent through two resonant metal
containers known as Rhunabatrons. In the first Rhumbatron is an
oscillating electric field, parallel to the stream and of such strength
as to change the speeds of the electrons by appreciable fractions
of their initial speed, accelerating some and slowing down others.
After passing this Rhumbatron, the electrons with increasing
speeds begin to overtake those with decreased speeds which are
ahead of them. This motion groups the electrons into bunches
separated by relatively empty spaces. A considerable fraction of
the energy of these groups can then be converted into power of
high frequency oscillation by passage of the stream through the
second Rhumbatron, within which is an oscillating electric field
so changing synchronously as to take energy away from the
electrons in the hunches.
"If the first Rhumbatron (which is called the buncher) is
driven by an external source of power such as an antenna receiving
radiation and the electrons are strong enough to give the second
Rhumbatron (which is called the catcher) more power than the
antenna gives to the buncher. the Klystron is acting as an amplifier.
"If the buncher is driven by power received through a coupling
loop or otherwise from the catcher, the Klystron is acting as an
oscillator. And finally, if the buncher is driven by power from both
of these sources at once, the Klystron is acting as a regenerative
amplifier."
Blind Landing: Continuing with his explanation of the Klystron's purpose, Mr. Gillmor says:
"This new blind landing system
(Continued on page 756)
RADIO
&
TELEVISION
Television's Interference Problem
Interference,
clue to the ignition systems
is becoming a major prop-
of motor cars,
lem among British television users. "Thermiou," feature writer for Practical and
Amateur Wireless. reports that Government departmental vehicles may soon be
equipped with spark suppressors, and that motor manufacturers are rumored soon
to make similar use of such devices. He further suggests that
everybody engaged in radio
and television install suppressors and that they be sold
to all purchasers of television
equipment. However. -Thermion" has said that nearly
five million vehicles are already on the road there and
that no legislation is likely to
be introduced until television
is far more widespread. "Thermion" suggests that the real
solution of the problem is to
allocate higher wavclem;ii
for t elevision transmissions.
The British writer seems to
have overlooked tin. fact II at
high frequencies are particularly suited to wide -band transmissions.
WBRK Joins Three Chains
The eight -mouths -old station, \\IRK.
l'ittsfielrl, Mass., became affiliated with the
Yankee. Colonial and Mutual networks on
larch Ist.
The station brings the Mutual complement to 110 stations, as of February 15.
To Brocdcast Yankee C;ipper's
First Flight
A shortwave relay broadcasting transmitter and associated equipment are installed on the Pan -American Airway's
Yankee Clipper .Vo. 17. This apparatus will
be used during its initial flight to Europe,
the program being broadcast
over the Columbia Broadcastins System.
Clyde Houldson. CBS field
technician, will act as announcer and operator in the
flight. The airplane's station,
\VCBN. has received an F.C.C.
license for eight special frequencies within the 1600 kc.
to 23 mc. band, with an output
of 100 watts.
The equipment is installed
in the lower compartment of
the plane's nose and is remotecontrolled from the radio
room on the upper deck. Its
weight is below 1000 pounds,
including spare parts, spill proof batteries and measuring
equipment.
A preliminary test of the
equipment was given (luring
the plane's test flight from
Seattle to Washington. It was
completely successful.
W RLD
Cabaret Televised
WIDE
RADI
DIGEST
New Mystery Station
British listeners are reporting the recepEngineers of the National Broadcasting
an unlicensed transCompany took television transmission tion of signals from
(U.S.S.R.).
Ukraine
in
the
located
mitter
in
RockeFrançais
Café
equipment to the
to Practical and
feller Center to pick up the floor show as The station, according
propaganda
presented to guests. Among those who Amateur ¡fireless, broadcasts
German, daily
and
Ukrainian
Polish.
in
camera,
television
before
the
performed
17:00 on channels
according to the New York Times. were: at G.M.T. 06:45 and
meter:.
36
28
and
hchvecrl
varying
venGaby.
Sheila Barrett. mimic; Frank
triloquist; Fats Waller. pianist, and sevSixteen Tongues on itol:an
eral skating acts.
Stations
NBC
The report further stated that an
Beginning the first of this year. the radio
executive says. "It is not likely that adconsiderably invertisers generally will become interested stations of Italy have
broadcasts.
language
foreign
their
creased
medium
in television as an advertising
the short waves, according
until there are perhaps 400,000 receivers particularly on Atnatenr It'irrless.
in this area. There are now only a few to Practical and
The stations now transmit news bullehundred television receivers in the same
and propaganda in 16 Lm_t:'iee <.
tins
locality."
HIS
General Electric Answers
Questions
n television are anbooklet. "A Miracle
by Dr. W. G. R. Baker of the
Electric Cl.mpany.
Among the facts which are brought out
is that transmission range is limited to
a radius of 40 or 50 miles and that no
economical system in interstation linkage
is yet feasible. (It has been rumored that
the National Broadcasting Company will
announce trans -continental television by
the end of March. -Editor)
Picture sizes, according to Dr. Baker,
will range from 2.4 x 1.8 inches to 9.5 x 7
inches. Receivers will probably cost from
Many
swered
Begins,General
yucrie,
in
a
ne
v
$150.00 to $1000.00.
MAYOR
HONOR THE MAYOR TALKS WITH HIS HONOR THE
Seated in his horse -drawn coach on a
London street. Major Sir Frank Henry
Bowater, Lord Mayor of London, conversed with Mayor Fiorello H. LaGuardia.
Mayor of New York. Their two -way trans Atlantic telephone conversation was rebroadcast over the National Broadcasting
Company network.
Mayor LaGuardia normally uses his
equipment to keep in constant touch with
the police and fire departments.
The major portion of the conversation
was on how pleased the two mayors were
to he able to talk to each other and to
hear each other so clearly. They also exchanged views as to the hours. it being
2 :55 p.m. in London and 9 55 a.m. in
New York.
Mayor LaGuardia invited the Lord
Mayor to attend the N. Y. World's Fair.
7;3
for April, 1939
www.americanradiohistory.com
(Continued from preceding page)
Flag -Pole Antenna
Because the Bell System's transmitting
station at Norfolk, Va., is located in a
residential section a few blocks from
the beach, an inconspicuous antenna was
desired. Therefore shunt excitation was
used, making it possible to employ a
standard steel flag pole.
As seen in the picture, a diagonal transmission line connects to a carefully selected point on the antenna, the base of
which is connected to a radial ground
system buried in the earth.
The tile and concrete transmitter station is automatic and requires no attendant.
S-W to Catch Crooks
According to General Hugh
Johnson, writing for
Scripps- Howard newspapers,
the police are now experimenting with a miniature battery- operated radio transmitter,
small enough to be concealed
in a brief case.
This outfit, installed in anyone's room or car, will transmit conversations taking place
in its vicinity over distances of
several hundred feet. Thus,
police in a nearby room or following in another car can over tear whispered conversations.
S.
TRAN5MIS51ON
LINE
New York's Fireboats Get 2 -Way Voice
Two -way communication between ship and shore has been made
possible with the installation of General Electric short -wave
transmitting and receiving equipment
on New York City's
ten fireboats, as
well as on the mainland. Lt. John H.
Reagan is shown
Shack of the Esso Baytown
When the New York -Bermuda plane crashed in the Atlantic
Ocean, she sent out wireless calls for aid. These were received
by shore stations; among them Radiomarine's WSC at Tuckerton.
This station, as did others, promptly sent out calls for aid to
ships at sea, and it was a call of this sort rather than one direct
from the airplane that was received by the Esso Baytown.
The operator on the Standard Oil tanker was off duty at the
time, but he had recently installed an automatic alarm which rings
a hell when SOS signals are received, calling the operator
to his
here using tie
handset of the new
50 -watt, ultra -highfrequency transmitter recently installed
on the Firefighter,
new $1,000,000 addition to the Fire
Department's fleet.
The boat's receiver
is a medium -highfrequency set tuned
to pick up all messages sent from the department's 500 -watt transmitter on the
mainland.
Regulations in Germany
shack, a picture of which is printed herewith. The result was
that radio had saved ten more lives. On Jan. 1, 1939, there were
1134 U. S. vessels equipped with the alarm system.
714
Those who aspire to become radio artists broadcasting over
German stations must pass official examinations. To enter these
examinations, they must show at least two years of study in the
entertainment field or have had professional experience. Of the
2,478 persons recently examined, only 1,125 passed the stringent
tests.
(Wonder if there aren't any amateur hours or quiz programs
in the Third Reich ?)
New regulations on Government licenses are also expected in
Germany. It is believed that the license fee will he reduced to
1
reichsmark for certain classes, and that free licenses will be
more liberally issued.
Those who now get free licenses in Germany include the Diplomatic Corps, The Hitler Youth Homes, the Hitler Youth Schools,
the Radio Departments of the Youth organization, the offices of
the Ministry of Propaganda and of the Post Office and Defence
Forces -the latter when the sets are being used in the defence
of the nation. This is said to amount to several thousands.
RADIO
&
TELEVISION
Facsimile
That 50,000 Hour Tube!
The long-life tul e pictured
here was developed in the Bell
Telephone Laboratories to meet
the peculiar needs of telephonic communications. These
include low- power consumption, uniformity permitting replacement without readjustment of associated apparatus,
reliability against interruption
of service, and continuous operation twenty -four hours a day.
This tube operates from a battery, the electrons being emitted from a coated filament. It
is not adapted to A.C. or D.C.
power line use. This, plus the
fact that the average radio
tube of today lasts about as
long as the set, should provide
an answer to those who have
asked. "Why aren't 50,000
hour tubes used in radio receivers in the home?"
Reaches
cidentally, will be sold at $1.00
per roll! A stylus at the end of
a moving arm which sweeps
over the sensitized paper, marks
each dot to be imprinted when
the current passes from the
Inventor inspects work.
on Next Inauguration
was
demonstrated in Washington, the
television
R.C.A.
When
New York Times retorts, Minnesota's Senator Lundeen, appearing before the microphone, asked the announcer whether the
Presidential inauguration of 1941 was to be telecast. An NBC
official then admitted that plans were on foot to do so.
New Service Suggested
British writer suggests that in addition to time signals and
weather forecasts, it would be a valuable service if radio stations
were to broadcast barometric readings. Many homes have barometers which are usually somewhat out of adjustment clue to the
lack of any available standard with which to calibrate and check.
Fire- Fighting at the Fair
To minimize fire hazards at the 1939 New York World's Fair,
a fire chief's car, which will patrol the grounds, is being equipped
with two -way radio.
In the accompanying illustration, the
fire chief is speaking into the handset of the General
Electric's 15 -watt
ultra-high- f requencv transmitter. A
superliet in the car
picks up all mes-
Public
Reproducer and special set.
To "Look In"
A
the
of
The Crosley Corporation, long pioneers in yariuus branchessale
for
receiver
facsimile
a
announced
the radio industry, have
to the public. The new receiver, licensed uner Finch patents, reproduces type and pictures on a strip of paper approximately
can
34" wide (printing space). While the facsimile reproducer
manube operated from any standard radio receiving set, the
facturer suggests the use of a special receiver and a doublet antenna.
He also believes that more satisfactory operation will be obtained
if an automatic time -switch is
used to turn the facsimile
equipment on any time during
the day when transmissions
take place and off at the time
they terminate.
Reproduction is achieved by
means of an electrochemical
process, current passing through
sensitized paper which, in-
Facsimile chassis exposed.
stylus to a roll behind the paper,
thus oxidizing the sensitized
coating.
Transmission is at the rate of
approximately three feet of
paper per hour. Station WL \V
is on the air with such transmissions between the hours of
1 A.M. and 6 A.M. Many other
stations are likewise sending
facsimile material.
n
u'
MIL
stn
ti -s. SNOW int
IS
EARTH. IT MAI DETERMINE iF THE 14.0E1 MARS
ASTRONOMERS
TO
IMPORTANT
INHABITED. BUT MOST
,
AND OTHER MEN OF SCIENCE. IT WILL ANSWER THE
IM`CILES?1ON THAT MEN HAVE ASKED FROM TIME
fi
MEMORIAL:
"W1Á1 LIES BETOMO THE BETONOT"
p
i
sages broadcast
from the headquarters station. Appropriately enough, the
background in this
picture is a Communications Building mural. Note
"mikes" at left.
for April.
Unretouched reproduction of transmission -Actual width
inches overall. Width of type is 35/e inches.
is 4
11/16
715
1939
www.americanradiohistory.com
What the Experts Are Saying About
Radio and Allied Arts
Here and Abroad
Vertical or Horizontal Television
Doublets
H. L. KIRKE, head of the Research De4 partment of the B.B.C., raised
the question of the desirability of vertical or horizontal polarization for television aerials, in
an address made to the Royal Society of
Arts. He said that in England Vertical
polarization has been used while in America, horizontal polarization is favored, because interference from automobile ignition systems affects the latter system less.
FOR
VERTICAL
POLARIZATION
ing, "Experiments have shown that for
the
O.B. radio link, horizontal polarization is
considerably the better, and with a suitable
design of transmitting and receiving array,
a gain of six to twelve decibels in signal
strength over the present arrangement is
expected, in addition to the improvement
obtained by the reduction of general interference from motor cars."
He is quoted by Wireless World as saying, "It is probably simpler to design an
aerial system with symmetrical radiation in
the horizontal plane using vertical polarization. Recent experiments have shown, however, that at any rate, in certain circumstances, a considerable improvement in signal strength has been obtained by the use
of horizontal polarization."
Noise Suppression Circuits
However, a change -over in the British
AS Fig. 2A shows, a burst of static
system would necessitate altering all their 2 or other extraneous noise
may overtelevision receiving antennas (estimated be- ride a signal greatly, with much
distress to
tween 2,000 and 10,000) now in use.
the listener. However, if the noise peaks are
Mr. Kirke concluded his statement say- reduced, as shown in Fig. 2B, it is barely
noticeable.
In noise limiters, the noise impulse is
rectified and used to supply a negative bias,
generally to the I.F. amplifiers. While this
is an ideal system for commercially -made
sets, it is hard to add to sets which have
already been completed, due to time lag
factors, etc. However, a noise suppressor
circuit of the total cut -off type may easily
be added to the A.F. stages of any set. Two
such circuits are shown in Figs. 2C and 2D.
In 2C, the suppressor is connected directly in the output of the final tube and it is
particularly adapted for headphone operation. The two anodes of the diode are at a
potential of 1% volts negative, this bias
being obtained from "C" batteries. When a
noise peak occurs, it causes one of the
anodes to go positive, thus short -circuiting
the phones for the duration of the noise.
Fig. 2D, also taken from Wireless World,
is a modification, in which the suppressor
circuit is inserted in the detector's anode
circuit, and the only components required
are a center -tapped A.F. choke and a duodiode tube. Bias may be obtained either
from batteries or from the cathode circuit
of one of the A.F. stages. A small variable
resistor of 50 to 100 ohms in series with
the bias resistor of the A.F. cathode will
supply the necessary voltage.
Simple Crystal- Controlled
Oscillator
TWO simple
circuits for crystal controlled oscillators are found in a
recent issue of Wireless World, a British
publication.
Fig. 3A illustrates the simplest form of
this type of apparatus. The values in this
3
716
RADIO
&
TELEVISION
Separating Video and Audio
Signals
finger along the string, just
standard instruments.
R2-
5,000 to
R1- 50.000 ohms;
10,000 ohms; while the values of CI, C2,
C3, C4 and LI are determined by the fre-
circuit are
quency of the crystal oscillator.
Fig. 3B uses a few more parts, enabling
the operator to make use of harmonics for
multi -band operation.
C5 in this diagram is often made variable,
but need not be, as once the adjustment
has been found, it can be left "set." I f the
circuit is tuned to resonate at a frequency
slightly lower than double that of the
crystal. it functions satisfactorily. The
points marked "X" indicate connections for
jack into which
a
a
milliammeter may
be
plugged.
Use
for Magic
Eye
a magic eye tube
for a frequency meter is indicated in
Fig. 4. According to the description in
Practical and Amateur 1Virelcss, this instrument is far more sensitive than on
employing a thereto- ammeter, and also
tunes more sharply. In addition, indica +ion
is instantaneous; the absence of lag bcimt
particularly valuable when tuning is subject to rapid fluctuation.
\\'hile this apparatus can be added t..
any existing frequency meter. it will alter
original calibration. The addition of a rectifier would increase its sensitivity, but the
self -rectifier shown is sufficiently sensitive.
4
A
CIRCUIT using
as
in playing
Overcoming Instability
6
,
:-
,
rquency receiver
is
used, oseillaw.n r instability is often
noticed before maximum valuate is obtained. Two simple ideas, illustrated in
Fig. 6, were described in Practical and
Amateur Il'ircicss.
The first idea is to "short" the reaction
choke in the detector stage. If this stops
the instability, the position of the .choke
should be changed or a shielded choke used.
Lt some cases, the addition of a fixed condenser across the B.F. choke will prove
effective, as shown in the a.F. stage of the
diagram.
If neither of these tests prove effective.
there is something radically wrong with
the lay amt or wiring of the set, the article
.
incoming teletheir associated
sound are applied across the terminals T
and T1 to the control grid of a pentode, to-.
gether with local oscillations from a source
7
AS shown in Fig.
vision signals with
7,
According to a patent recently granted to
Ferranti. Ltd., and G. M. Tomlin, if the
picture signals are transmitted on a carrier
of 45 megacycles and sound on 41.5 megacycles, a local frequency of 32 megacycles
is used. In the an(xle circuit A, the tuning
of which is broadened by a shunt resistance R, a difference frequency of 13 megacycles (45 -32) is produced and transferred
to the I.F. stage Al of the picture channel.
:\ second tuned circuit, B, is connected to
the screen grid, and is (Ieeoupled by a resistance R1 and condenser C. Here the
second difference frequency of 9.5 megacycles (41.5 -32) appears and is passed
Continued on following page)
BRASS
CLAMPING
BOLT
Although an external rectifier improves
the unit somewhat, it complicates the apparatus and raises its cost.
Electronic Musical Instruments
5
OLD headphone
magnets
may
be
utilized to build home -made electronic
musical instruments, as described in Practical and .Amateur iVireless.
Fig. 5.\ shows the principle. In this
arrangement, a single stretched metal
"string" vibrates between the poles of the
two coils, which should be spaced as cLsc
as possible without permitting the string
to touch them on its maximum vibration.
The coils are in series, their free ends being
connected to the input of an amplifier.
Fig. 5B shows how the unit may be
assembled with a single stick of wood in
order to make a one- string fiddle.
Fig. 5C shows a multiple unit, as designed
for a guitar. The unit is mounted on a piece
of mahogany and the strings stretched
above it, each positioned accurately over
its pole- piece. Various notes other than
fundamentals are secured by sliding the
for April,
717
1939
www.americanradiohistory.com
INTERNATIONAL
RADIO REVIEW
(Continued from preceding page)
through a separate amplifier, BI, to the
sound channel. The arrangement avoids
cross -modulation and prevents undue attenuation of either set of frequencies.
8
Simple Radio Time -Switch
A TIME-SWITCH which can
be
made from a common clock and little
ether apparatus is described in Populaer
Radio of Denmark.
As Fig. 8 shows, one contact is made
direct to the hour hand of the clock, while
the other is made to a contact which may
be positioned at any spot on the dial. In
series with these two points is an electromagnet (which may be removed from an
ordinary ten -cent store door bell) and a
4% volt flashlight or "C" battery.
This electro-magnet operates a trigger
to trip a switch which is in series with the
power line to the set.
Reducing Hum in S.W. Receivers
\CCORDING to Practical and Ama-
SENSITIVE
9
RELAYS
PLUNGER
A2
OIL
MERCURY
B+
TRANSMITTER
OR MODULATOR
PERCUSSION
h'ur Wireless, the simplest way to determine the cause of hum is to check the
output of the detector stage, which may be
done with a pair of headphones. This stage
is most likely the source of the trouble.
While equipment of adequate size to carry
the complete current for the plate of a
multi -tube set must be rather heavy and
therefore expensive, it is comparatively
cheap to supply additional filtering for the
detector stage. The diagram in Fig. 9 indicates this, the point from which a separate
detector supply may be taken being marked
X. A standard audio choke may be connected at this point. Better clarity will be
obtained if a condenser network is used
with the choke.
flat response from 40 to 9000 cycles. As
shown in Fig. 11A, the unit is mounted at
the center of a 3 -foot panel which forms
the front of a box 12 inches deep. The box
is lined with cotton batting and a back
provided. At the center of the back, a one
inch hole was drilled to prevent compression of the imprisoned air. A view showing
this is given in Fig. 11B, for a complete
plan.
For such readers as may wish to experiment with this type of baffling, further data
is given at 11C.
New Pick -Up Feed
A NEW and improved Italian pick -up
is described in the German publication Radio Mentor. The speaker is easier
to load and to discard needles from than
any other unit hitherto seen. As shown in
Fig. 12A, a used needle is discarded merely by loosening the screw S. When the
handle H is pulled down, the needle slides
along it and falls into the needle container
C. The needle is replaced by being inserted
from the top, as shown in Fig. 12B.
12
N-I
(__
I
P
HOLE
Circuit Breakers Protect
Transmitter Tubes
AN article by Rene Jourdan, F8LO,
appearing in Le Haut Parleur "8 ",
describes an interesting means of protecting transmitter tubes by means of simply
constructed relays and a mercury switch.
The variable resistance R is inserted in the
circuit to permit careful adjustment of the
relay. Al. When normal current is flowing into this circuit it energizes Al.
This permits the circuit S to be closed.
If excess current flows in the circuit S,
the relay A2 is actuated, opening the mercury switch. Oil is provided in the switch
to prevent arcing.
10
LINED
3 FT. SQUARE
WITH
COTTON
(BOX
PERCUS-
SION
HOLE
Baffling for High Fidelity
RECESSED
BACK L'
SPKR. LEAD
HOLE
no speaker can be better than its
11 AS
baffle arrangement, an article by M.
McGowan. VK2MZ, in the Australasian
Radio World, is particularly interesting.
The speaker used had a comparatively
718
You will notice the handle, pivoted at
B, returns to position so that, as shown in
Fig. 12C, it forms a gauge permitting the
needle to extend the correct distance and
no further.
A Letter from London
In the
January
issue of RADIO &
was stated that the Birmingham- Manchester co-axial cable had been
abandoned for television use and would be
used for telephone conversations. In reply
(Continued on page 751)
TELEVISION, it
RADIO
www.americanradiohistory.com
&
TELEVISION
}2otiart ficñGary's
)Qd0 l'ejt-2til3
For each question answered fully. count
10
points; half tight.
Radio programs are generally loyal to
the theme music, which identifies them year
after year -but early in 1939, which of the
following changed its theme music?
1.
a. The Good iVill
¡lour.
Easy Aces.
e. The Jack Benny Show.
b.
d. The Oak Bucket Boys.
4-
WH /CH CHANGED
/Ts THEME MUS /C
According to the latest complete FCC
report (July 1, 1938) there were six broad2.
cast frequencies, each of which had more
than 50 stations on it. Match the frequency
with the number of stations using it. in the
table below.
a. 1200 kc.
b. 1210 kr.
c. 1310 kc.
d. 1370 kc.
c. 1420 kc.
f. 1500 kc.
A. 65
7. Since the public learned of "long life"
tubes. which give 50.000 hours of operation
in telephone service, there has been sonic
f. Bombay
ordinary tubes.
they would ruin dealers' replacement
business.
r. ordinary tubes usually last about as
long as average receiving sets.
d. receiving set circuits change too
rapidly.
B. 51
C. 59
D. 53
E. 64
F. 60
3. The simplest way to make a volume
expander is to
a. increase the "B" voltage ou the R.F.
stages.
b. reduce the "C" voltage on the output stage.
r. connect a pilot light across the loudspeaker voice coil.
d. connect a 110 -volt, 60 -watt light bulb
in series with the negative "B" lead.
As this goes to press, motion picture
producers are agitating to keep movie stars
from broadcasting. Which of the following broadcasters have appeared in motion
pictures?
a. Fannie Brice.
8.
c.
d.
"Honcychile"
Gracie. Allen
San Fra cicco- KGO-KPO
Salt Lake City -KFT.l -KDYL
r. Denver-KVOD --K0.1
d. Omaha- KO /L- 11'OlV
r. St. Louis- KiVK -KSD
a.
b.
?1
6.
Of the following features, introduced
some time ago, which is not used as much
as
formerly in radio receivers?
d. A.T.C.
A.F.C.
c. A.V.E.
b. A.1'.C.
f. P. -B.T.
n.
for April,
?1-?
?
WEST
FFL
Robert Benchley.
f. Rudy Vallee.
e.
BLUE
RED 4 BLOF, WANCN ARE FARTHEST WE5T7
9. Some of the new concentric cable has
the space between the inner and outer conductor filled with gas under pressure. The
purpose of this is to
a. increase the capacity between the two
conductors.
b. keep moisture out.
r. provide a method for detecting electrical leaks in the outer conductor.
d. raise the inductance of the cable.
The aerials used to radiate the NBC
television signal from atop the Empire State
Building in New York are
10.
horicantal rod dipoles.
vertical wire dipoles.
skeleton masts.
d. torpedo shaped.
14. Of all the various bands, which of the
following is the highest wavelength allocated to television in the United States?
500 kc.
b. 1000 kc.
a.
c. 2000 kc.
d. 50 me..
e. 70 tnc.
f. 100 inc.
15. When hooking up a double- button
carbon microphone for "home broadcasting," the best way to connect it is
a. directly across the grid and cathode
of the detector tube.
b. directly across the grid and cathode
of the first audio amplifier tube.
r. to the grid and cathode of the detector
tube through a special coupling transformer.
d. to the grid and cathode of the first
audio amplifier tube through a special coupling transformer.
3
16.
sists
5. And the ratio of the depth of cut
to width of cut should be
d. 1:2
a. 5:1
c. 1:5
b. 2:1
f. 1:7i_
e. 1:1
Meredith Wilson
D. Kaye Kysrr
C.
13. Of the following stations, one is the
farthest west station of the basic Blue net work: another the farthest west of the basic
Red network. Identify these two stations.
Ben Bernie.
d. :linos 'n' Andy.
b.
c.
is poor.
12. The glamorous feminine comedienne
of a certain broadcast is called "Stinky" by
the orchestra leader of the show. Can you
lind their names in this list?
A. Skinner Ennis
a. Fannie Brice
B. Peter l'an. Sterden
b. Martha Raye
C.
a.
making recordings- perhaps for
veris -on acetate blanks. the proper depth
of the cut is
d. 0.0025 inch
a. 0.015 inch
e. 0.005 inch
b. 0.025 inch
f. 0.0005 inch
e. 0.0015 inch
In
(falter Il'inchell.
GO
E. 3:00 a.m.
F. 10:00 a.m.
c. Yukon
discussion as to their availability for broadcast reception. Which of the following has
or have been given as reasons why these
tubes have not been made available to the
public?
a. they cost 15 times as much as
b.
a good score is 110; below
points; etc. A perfect score i. 170:
b.
r
4.
5
WN /CH /5 THE LATEST 7ELEY. AERIAL
?
11. If you are a short wave listener in
Chicago, and the tinte is 8 :00 p.m. where
you are, what will be the approximate time
in the following places whose stations you
tune-in?
A. 3 :00 p.m.
a. Rio dc Janeiro
B. 5 :00 p.m.
b. Manila
C. 11:00 p.m.
e. Rouse
D. 7 :00 amt.
d. Nome
a.
b.
r.
d.
A line noise filter ordinarily
of
A.F. choke coils.
R.F. choke coils.
fired natden.cers.
variable condensers.
con -
The Purple Network is the name for
a. the Mutual Broadcasting System chain.
17.
b. the Colnmbia Broadcasting System
chain.
e. the combined Red and Blue chains of
the National Broadcasting Company.
d. the Intercity Broadcasting System
chain. (See Answers, page 757)
719
1939
www.americanradiohistory.com
LATEST
INTER -
No.
ßlartman glasig
tic
PLANET
NEWS
3
TRANSMISSION:
COSMICLEAR
APRIL, 1939
tgije Olartían
inagij
An Inter-Stellar Magazine for all Radio
Enthusiasts.
Published :-When Interplanetary Conditions Permit.
Interplanetarian Pub. Co., (Very) Ltd.
gipst- Editor
Subscription Price for All Planets
Priceless.
-
The Editor accepts no contributions of
any kind, neither cash nor literary. This
entire publication is read at your own
risk. The Editor is not responsible for
either the contents or your own reactions.
-
Martian Office
698743209 K K K 9 Street,
Martolus, Mars.
Fips, the Office
Boy, who tells us
Price: None
rarefied atmosphere. For this reason the
Martian nose grew longer and longer so
that it could get toward the source of
the smell rather than have the smell
come to it.
The telescopic eyes are also due to
evolution because the Martians, using
their eyes continually, found it necessary
to grow eyes which could accommodate
themselves better to their complex mode
of living than fixed eyes. There is nothing new in all of this. Barrel chests are
already in existence among certain inhabitants of the South American Andes.
Another example is the elephant's nose.
The peculiar shape is necessary because
its huge bulk hinders it in kneeling down.
Therefore the long, flexible nose has
been evolved. Pop eyes are not new
either. Snails and certain fishes have
had them for millions of years, not to
speak of Eddie Cantor!
As for the web feet, you know that
gravitation on Mars is very low. For
instance, my weight on Earth is 160
pounds, but is only 60 pounds on Mars
Consequently, to get a better foothold
for the large proportioned body, the web
feet were evolved by nature. The antennae on the Martian's forehead are not
so new either because your insects on
Earth have had them for many millions
1
April,
1939
EDITORIAL
1
MANY of
our readers
have written in
asking for information as to how the Martians, as
illustrated in the previous issues of The
Martian Flash, got that way. In other
words, why the telescope eyes, the barrel
chests, the elephantine nose and the web
feet ?
The answer is simple. The atmosphere
on Mars is so thin that it actually compares with the tops of the highest mountains on Earth. Mars, being much
smaller than the Earth, lost most of its
atmosphere through the ages and now
has very little left. Indeed, it would not
have much at all if the Martians themselves did not replenish it continually by
artificial means. When I first came here
I had continuous nose -bleeds and I was
continually gasping for air. Now I am
equipped at all times with a simple
pocket apparatus which automatically
gives me a sufficient amount of oxygen.
without which I could not live at all on
Mars.
Down through the ages the Martians
had to adjust themselves to the rarefied
atmosphere and that is why they must
have enormous lungs (which require a
large chest) to compensate for the
rarefied air.
Scents and smells travel poorly in a
A close -up of Earth 1,250,000 years ago,
showed ape -like beings, but no men.
!
the latest happenings on Mars.
720
MARS -EARTH
SPACE
" -the upper atmosphere
served as
a
of mirror screen for television images
sort
-"
-
of years. So, you see, there is nothing
new under the sun, and the grotesque
to you -is after all not so grotesque as
you imagined.
MARTIAN TELEVISION
*
By Ulysses Mohammed Fips
Martian Star Reporter *
*
EVER since my articles have appeared
in The Martian Flash there seems
to he an intense interest among the readers regarding the present status of television on the planet Mars.
Let me say that, as you can probably
imagine, television has been here for
many millions of years and therefore it
is somewhat different from what you
would expect it to be.
To begin with, at the present time it
is quite unnecessary for Martians to
have any television receiving apparatus.
Like many other things on Mars, all
forms of communication have been personalized in the Martian himself. At
first this was not the case and television
was received on screens similarly to
yours on Earth. Refinements then
brought pocket television receivers and,
much later, television receivers which
could be strapped to the wrist ; still later
they got so small that by means of a
special lens, you could view excellent
images on a small finger ring and get
the sound as well. Still later, huge television images were projected into the
rarefied upper Martian atmosphere similar in principle to Northern Lights on
Earth. These images were so colossal,
yet of such excellent quality, that the
upper atmosphere served as a sort of
mirror screen and standing on the surface of Mars you could enjoy television
in full colors any night of the year. As
there are practically no clouds on Mars
at any time, good television views were
always to be had in this manner. These
images were from 9 to 15 miles above
the surface of Mars and you may imagine how huge these images must have
been in order to see them plainly from
Mars' surface. While such television exhibitions are still being used, especially
for extraordinary occasions, nowadays
the television images are received directly on the retina of the Martian's eyes.
The reception comes over the Martian's
antennae and the special wave motions
are conducted directly toward the back
of the eye. All one has to do is close one's
eyes and see the transmitted television
(Continued on page 762)
RADIO
&
TELEVISION
More About
FREQUENCY
MODULATION
Details of the G. E.
12-Tube Receiver
Left -Dr. W.
R.
G.
(standing),
radio
Co.,
G.E.
engineer, watching
H.
ArmMajor E.
strong demonstrate
mod"frequency
ulation" receiver.
Baker
at r i g h t
Photo
shows the appear ance of the fre-
quency modulation
receiver.
modulation
AS explained in our last number, sev- lion on the standard amplitude
this imeral transmitting stations designed to method, stated, "In sonic cases decibels
t1) 25
utilize the new Armstrong frequency modu- provement is as high as 20
there is a
lation system are being erected, and Pro- (100 to 300 times). This means
and
from
atmospherics
freedom
remarkable
fessor Armstrong's transmitting station,
W2XMN at Alpine. N. J., will be in opera- man-made static, such as X- rays, automoelectric
tion this spring. Arrangements are being bile and aircraft engine ignition.
etc.
sparking.
commutator
motor
fidelity
prohigh
made to broadcast the
"The results show such a marked adgrams from station WQXR.
in netI. R. Weir, G.E. engineer in charge of vantage for frequency modulation
is believed that even
it
operation.
work
report
in
recent
a
development,
transmitter
would be reon measurements made of the noise reduc- with the modification which
actual
tion effected by the Armstrong frequency quired in applying the results to
(C'outintied on page 7461
modulation system, compared to the recepDue to the widy. frequency
Wiring diagram of the new G.E. 12 -tube "frequency modulation" receiver.
free from static and other noises.
band employed. extraordinarily high fidelity reception is afforded,
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SPACERS
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for April,
L_1-Á
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ADDED
NOTE. COIL. DATA
TS SAME AS T4 TO T7.
n1n P
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TRANS
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EC
um-BULN COIL
REFLECTOR
1939
711
Ultra -High Frequency Antennas
500 WATT
TRANSMITTER
100
FEE1
RECEIVED
SIGNAL
300
/V
lO MILES
50 WATT
TRANSMITTER
RECEIVED
SIGNAL
500
FEET
10 MILES
500 "/,.,
10 MILES
-Al
quantitative importance of
shows the
I
the antenna height. In the three cases, the
transmitter power is adjusted to give equal
signals at a fixed distance for three heights of
100 feet, 320 feet and 1,000 feet. The respective transmitter powers required are 500 watts,
50 watts and 5 watts. In so far as the listener
is concerned, the effectiveness of the three
stations is the same although there is a great
difference in power. Effective power is proportional to the square of the altitude or height.
Coaxial Antenna
AN ideal antenna for ultra -high frequency applications is one which uniformly radiates the strongest possible signal along the surface of the earth. To
attain this objective, it must be mechanically
designed for easy mounting at the top of
a high pole to take full advantage of height,
and further it must be electrically designed
to radiate most efficiently in horizontal
directions for the greatest utilization of the
radio power.
The coaxial antenna (Fig. 2) represents
a practical form of this antenna utilizing
certain new principles that attain the desired objective. Its slender proportions,
short length, light weight and coaxial symmetry enable it to be applied easily to high
steel poles of standard construction. Its
superior radiating capabilities make it the
most modern approach to the idealized radio
antenna.
The ultra -high frequency radio antenna
may be considered as somewhat similar to a
beacon light except that it emits polarized
radiations of a longer wavelength. It. too
must be placed high above the earth if i
Fig. 2. Method of terminating lower end o
coaxial antenna in a very high impedance
UPPER
SHORTING
BAR
T/4
BRASS
BUSHING
INNER
SURFACE
TUBE
OF
r/4
OUTER
SURFACE
OF LINE
CONCENTRIC
LINE
t
722
STRAY
B
ZAB'CC
transmitting over long
distances.
In most practical cases the radio equipment is located at ground level in a building
and is connected to the high antenna by
means of a transmission line. In this discussion a low -loss concentric type transmission
line will be assumed. In this line the useful
current at ultra -high frequencies is carried
by two paper -thin metallic conducting surfaces first, the skin surface of the quarter inch copper inner conductor which may
be considered as the outgoing conductor
and secondly, the inside skin surface of
the seven -eighths inch copper sheath which
may be considered as the return conductor.
The outer surface of the seven -eighths
inch copper sheath plays no part in this
transfer of useful energy in the idealized case.
By reference to Fig. 2 which shows a
cross -section of an elementary form of
a coaxial antenna a new circuit element
is evident. The enclosed sheath of the transmission line acts in conjunction with the
inner surface of the larger surrounding
tube to form a short -circuited quarter -wave
concentric line. The characteristics of this
shorted section of line cause an extremely
high impedance to be created across points
A and B. By simple analogy this is equivalent to a high Q anti- resonant circuit which
isolates the pole below point B from the
antenna and reduces the stray pole current
to a minimum.
When this antenna is supplied with
power, the center of the antenna is at
minimum potential, the top is at a high
potential and the bottom of the tube is at a
high potential. The presence of the high Q
anti -resonant circuit element at the bottom
of the tube allows this high potential to
exist even in the immediate proximity ci
the transmission line.
The concentric line which feeds the antenna is a standard seven-eighths inch
diameter gas tight line and is placed for
mechanical strength inside a heavy bras,
supporting pipe approximately 2 inches iu
diameter both terminating in a solid bras,
bushing at the feed point, i.e., center of
the antenna. A three -inch diameter coaxial
tube is attached solidly to this bushing at
the feed point and elsewhere is kept insulated from the 2 -inch pipe by internal
ring insulators. The quarter -wave rod
projects through a sturdy insulator at the
feed point and is connected at the feed
point to the inner conductor of the transmission line.
Electrically, this coaxial antenna is a
center -fed doublet and consequently closely
matches the surge impedance of a standard seven- eighths inch concentric line. The
doublet or dipole antenna consists of the
quarter-wave rod and the outer surface of
the three-inch tube which is also onequarter wave long, making a total active
radiator length of one -half wave.
At a frequency of 35.6 megacycles, a
coaxial antenna was substituted directly for
a "J" type antenna and comparative field
intensity measurements of the signals were
made in two directions and at two distances
away from the station. The measurements
in this case showed an 8 db. increase in signal strength in favor of the coaxial antenna
for equal power input. To obtain a similar
increase in signal strength from a 500 watt
station by changing the carrier power alone
would require an increase in the power of
the station to 3 kilowatts !-Courtesy
"Pick- Ups," Western Electric Co. publication.
;
RECEIVED
SIGNAL
Fig.
is to be effective in
Rotating Beam Loop
For Ham & SWL Use
SINCE very little seems to have been
done (or at any rate published, beyond
bare specifications) with folded aerials,
these appeared to offer the best field for
experiment, and possessed many obvious
advantages when it came to considering 56
mc. propagation. Long aerials are clumsy,
unless one lives in the depths of the country, and are certainly unsightly.
The problem soon boiled down to one of
mechanical difficulties, and it is the simple
solution of these that is offered now.
A rotating beam was indicated, as narrow as possible, provided compass points
were marked on the dial. The Reinartz
double loop is compact, easily pushed up
beyond trees or chimney pots, and it seems
could be made very light ; no small consideration this, when it has to be lifted 40
feet up. Wind resistance could also be
reduced to a minimum.
No claim for electrical efficiency is made
so far as experiments are being carried
out with feeder lines, but it gives an 18
per cent increase over a dipole, and 6-1
ratio from back to front. For reception, car
interference with a low dipole is a very
serious problem, but is reduced by an amazing amount when using this method.
Fig. I. The construction of the 56 Mc. Rotai
irg Beam.
Fig. 2. The loops used for the 56 Mc. Rotating
Beam.
A coaxial cable would solve feeder problems nicely, and several types of such
cable are now available on the market.
Construction
A 30 -inch cross of P4 in. by 1 in. pine
was made by halving at the center, and a
slot cut in an 18 -inch support of 2 in. by
2 in. (Fig. 1). By shaping the bottom of
the slot with a tile, and pinning at the
center, a tight fit with no play was obtained.
A half -inch hole 12 in. long was drilled in
the bottom to fit over a length of pipe,
driven 6 inches into the top of the mastOne metal washer gave a smooth bearing.
An old ebonite lead -in tube 18 in. by 2 in.
with % in. walls was used, but wood is as
good for the support.
Three discs of % in. wood, one soft 6 in.
in diameter and two oak 7% in. in diameter,
were fitted 2 in. from the bottom of the
support, with a screw at each end of a
diameter to hold it tight. This forms the
pulley for a continuous rope to rotate the
loops.
(Continued on page 763)
RADIO
&
TELEVISION
whet Pa fou 1hbh?
A "Ham" Replies to "SWL Punk"
Editor,
I would
like to answer
Mr. Austin
Wardman's very interesting letter in the
February issue and give my opinion of
the QSL situation from a "Ham's" point
of view, which may or may not be representative.
First, I would consider the SWL and
Ham hobbies two very interesting but distinctly different ones. To be a successful
SWL DXer takes a great amount of time
and effort. Hours must be spent identifying
new stations well enough to get confirmations. In the end. success is the reward.
"Ham" radio, on the other hand. requires
much time and effort, but in a different way.
I don't think either of these hobbies, to be
successful, can spare much time for the
other. I'm quite sure Hams almost never
have time to listen anywhere but on the
particular band they are working; in fact.
I have managed to keep very busy on about
100 kc. of the forty meter band for a year
and a half.
Many prospective amateurs have in mind
to go on fone only when they get their
"tickets," and consider code just a "necessary evil." I know because I was that
way myself, but now I think that is all
wrong and after 11/4 years "on the air"
I have no desire to go on fone. The lone end
is O.K., but a fellow should become a really
good c -w operator first, in my opinion.
That means to be able to send code and
receive accurately at least 25 wpm, and
also know correct operating procedure. Mr.
Wardntan, Hain radio welcomes fellows
like that and you will have plenty of
contacts.
The prospective Ham should buy, if possible. a really good "communications" type
receiver, provided with a beat oscillator,
of course. An audio oscillator is not needed
if you don't wish to build one for keying
practice, as you can place your key in series
with the head fores to receiver and use
almost any station to key on their beat note.
Many short wave commercials have their
carrier on the air continuously and WWV
(5000 kc.) transmits a 400 cycle note continuously from 4 p.m. to 2 a.m., which is
good for keying.
Of course. I won't go into the building of
"rigs" as that is always well covered in the
magazines. However, I might say that even
a single 6L6 and a good antenna with about
25 watts input will give you much pleasure.
Many fellows work "all over the world"
with a little rig of that type. I used a
single 6L6 for some time with very tine
results.
The perfection of code technique is a
very fascinating game, and I would suggest
that Austin become an enthusiastic C \\'L
(continuous wave listener). I'm sure the
boys on cw would more readily QSL, as
they would consider a fellow interested
enough to copy call letters worthy of a card.
Most of the SWL's looking for cards from
Hams are naturally sending their cards to
the boys on 20 meter fore. Many of these
boys may have received an initial bunch
of cards years ago, used them all and never
bought any new ones since. So how could
you expect to get a card from them? Then
again they may have a few cards but save
them for their unusual two -way contacts.
I used to get cards from CWL's and was
always very happy to send them a card
in return but lately, I haven't received one
card from CWL's. Guess I'm slipping, hi!
for April,
I have liad over 1500
two -way contacts in my
11/4 years on the air, but
as I look over the QSL
card situation, I find only
about 300 cards there.
That has kept me quite
busy though, and I fear
I would need a secretary
here to QSL 100 %. I can
say that the Hants I have
sent cards to have QSL'd
practically 100 %.
Austin wishes to know
why the Hams are in this
game anyway. I would
say a vast majority are
in it to improve their
operating technique, and
to carry on an interesting conversation on the
air, not merely to say.
Ruppert, 226 East
N. Y. City, is this
yr's.
month's prize winner
Herman
81
St.,
subscription
to
-I
R &T
station of OtaHalas, Brno 2, Krizova
44,
Czechoslovakia. Ca II
OK2RR.
Amateur
kar
Honorable mention -six
months' subscription, to
Domenick Ferrari.
Fan-D.R.D.
S -W
Famous
Wadia, 203 Walkeshwar Rd.,
Bombay, India. (Pres. of India Radio Amateurs' League.)
"Pse qsl es cul." Some
of the old- timers don't get
on the air. for they are
afraid of finding "Lids"
there. hi!
So all you fellows get
on the air and show them
-there are some fine
operators cooling up.
Well, here is wishing
all the SWL DXers the
best of luck. Incidentally.
I could use a little luck
here myself as I need
a couple of states for
w.A.s. and Africa for
.:
'43,4
11
_
i
,
j
w.A.c.
So 73, es I'll bow soon
"on the air."
RADIO W2KSL,
Wm. GORDON,
Apt. 3 -C,
3140 Kingsbridge Ave.,
Bronx, N. Y. City.
He Likes Our Television Articles!
Editor,
I have been a reader of your very FB
magazine for four or five years and I can
sincerely say that I find it very interesting and helpful in all branches of radio. I
am a student of commercial radio and
television with the First National Television in Kansas City, Mo. Your articles
on commercial radio and television are very
; I also like your International
Radio Review and I never pass over What
1)o You Think? without getting a great
"kick" out of it.
My receivers are a Raco Super Clipper
and a Doerle five -tuber. I have only a few
helpful to me
vcris because I spend most of my time
experimenting with new receiving circuits.
amplifiers, photo-cells and cathode -ray tube
circuits. Some of this equipment can be seen
in the photo. I am proud to be a member
of the Short Wave League.
More power to your magazine under its
new name. ( See photo herewith.)
DOMENICK FERRARI,
617 Smith Ave., N.\\r.,
Canton, Ohio.
723
1939
www.americanradiohistory.com
Diagrams above show untuned R.F. amplifier, tuned R.F. stage and tuned impedance R.F. coupling.
RADIO
BEGINNER
The
WE can, for the sake of convenience,
mentally divide a radio receiver into
three separate parts. One of these, the section pertaining to detection, has already
been considered in a previous article. The
other two are the audio frequency amplifying and the radio frequency amplifying
sections. It is with this latter part that we
arc now concerned.
We have already learned, during our consideration of vacuum tube operation, that
the detector tube takes oscillations of radio
frequency and turns them into direct current impulses. It might be thought that the
output of this detector tube would van_ in
direct proportion to the input voltage applied to the grid. However, as the grid
voltage is lowered a certain point, known as
cut off grid voltage, is reached, below which
there will be no effect in the plate circuit
of the detector. In other words, the signal
supplied by the antenna (that is, the radio
frequency oscillations) must be of a certain
order of magnitude before a response will
be secured from the detector. The use of
one or more stages of radio frequency amplification enables the signal to be built
up to such a value that detector action can
definitely be secured. This amplification
ahead of the detector tube makes it possible to receive stations which would otherwise be inaudible. When a potential greater
than cut -off grid voltage is applied, the
output in the plate circuit of the detector
increases more rapidly than the square of
the input voltage.
Unfuned R.F. Amplifier
Figure 1 shows a multiple stage manned
radio frequency amplifier. The very small
alternating, high frequency wave received
by the antenna causes a current (of the
same frequency) to flow in the antenna
circuit, comprising the antenna itself, the
antenna coil, and the ground. The current,
flowing through the antenna coil (or the
primary) creates a magnetic field which in
turn causes a potential of the same frequency to be induced across the secondary
of the coil. Note, however, that this sec-
Ali on
Radio `Ttapancy
Martin Clifford, W2CDV
ondary is in the grid circuit of the first
tube, and hence this potential is impressed
on the grid. 'We recall from our discussion of the vacuum tube that a small potential on the grid can control a comparatively large current in the plate circuit.
This current flows through the primary of
the radio frequency transformer (marked
RFT -1). Once again, as in the antenna
coil, we have magnetic action and consequently a voltage induced across the
secondary of the coil, and impressed on
the grid of the next tube. A sufficient number of radio frequency (abbreviated R.F.)
stages can be used until the signal is of
such strength that it can be detected.
It should be observed that the voltage
amplification is sometimes secured only by
means of the tubes. The purpose of the
R.F. transformers is to obtain an alternating voltage across the secondary (or on
the grid of the tube) from the varying plate
current of the preceding tube. We also
secure a voltage step -up having the secondary wound with more turns of wire than
the primary. There is a tendency in such
an inductance for the amplification to increase as the frequency increases. This
would mean that the amplification would
not be constant over a wide range. Such a
coil arrangement would tend to make the
circuit unstable, since there would be the
possibility of feedback through the tube
capacity. Where the primary and secondary
of an R.F. transformer are of the same size,
amplification, although somewhat lower, is
fairly constant over a wide range, and with
less feedback. By feedback we mean that
condition whereby a tube begins to act as
an oscillator or a generator of radio frequency energy. :\ tube, designed to act as
an R.F. amplifier, and behaving as an oscillator, causes howling, squealing and loss
of efficiency in reception.
We have so far considered a type of R.F.
amplifier rarely used today. An untuned
system of transformer coupling will cover
724
6
j, qi¢r.s
-Pm
only a very limited range of frequencies and
is unsatisfactory. The purpose of an R.F.
amplifier should be not only to increase
signal strength, but also to increase
selectivity
Tuned
R.F.
Amplifiers
When we deal with an R.F. amplifier, we
must handle waves that vary from a few
hundred thousand cycles per second to several million cycles. In order to secure
greater efficiency from our R.F. transformers, we place variable condensers across the
secondaries of these coils, thus enabling us
to tune in the particular frequency we want.
See Figure 2. This type of circuit is known
as a tuned radio frequency amplifier and
(Continued or page 748)
These diagrams show resistance -coupled R.F.
stage and band -pass fiiter or tuner to increase
selectivity.
BAND -PASS
TO
F/LTE2
SHARPEN TUN/NO
RADIO
www.americanradiohistory.com
&
-
TELEVISION
Electronic Television Course
Henry Townsend
Lesson 2 -Photo Cells, Iconoscope, Image Dissector
PHYSICISTS in their experiments with the alkali metals
have found that light falling upon these metallic films produced
enough energy to dislodge electrons from these surfaces. These
electrons were collected by a positively charged electrode and
currents of small magnitude were able to be passed through the
tube. The alkali metals which show this photo -electric effect are
Lithium, Potassium, Sodium, Rubidium and Caesium. Caesium
and its compounds, when deposited upon other metallic films,
respond to that particular part of the light spectrum which nearly
approximates the response (or sensitivity) of the human eye and
also shows the greatest photo -electric effect for a given amount
of visible light of any of the photo -electric metals; consequently
it is most commonly used as photo -electric material in television
IilhI/'
I -B, a
photo cell; 2-A-I -A and
Fundamental action of the Iconoscope; 2 -B- Iconoscope pick -up;
Typical Television Transmitter Line -up;
3 -Image dissector;
Form of scanning pulse; 5 -A -How interlaced scanning takes place.
+
5-
and line by line. This discharge is then amplified by a series of
amplifiers to a level where it may be tral:smitted over a co -axial
cable and modulate a television transmitter.
The invention of the iconoscope is credited to I)r. Vladimir
Zworykin of the RCA Laboratories. Prior to this, Philo T.
Farnsworth was the first inventor to show a successful electronic
picture tube, which he called the Farnsworth Image Dissector.
This image dissector, shown in Figure 3, also incorporates a
photo-sensitive cathode at one end, upon which an image is
focused, similar to a photographic camera. This image causes a
flow of electrons where light strikes it, and some distance away
from the cathode we have an image in the forni of an electronic stream corresponding to the light and dark portions of
the image. This electronic image is then moved past an aperture
in both a vertical and horizontal plane and the electrons are
collected by a positively charged electrode in the proper sequence,
then amplified as in the case of the iconoscope.
Still another type of picture tube used today is called a
monosCnpe because it will only transmit or reproduce one image,
namely, the image deposited in carbon on a target electrode,
usually made of aluminum. This tube operates by virtue of the
fact that carbon is a poor emitter of electrons. It consists of an
electron gun, focusing electrodes, and electrostatic or electromagnetic means of moving a beam of electrons across this printed
image. plus a collecting electrode to collect the secondary electrons which are emitted from that portion of the target which is
not covered by the carbon deposit forming the image. This tube
has an exceptionally high output and is used chiefly for testing
or demonstrating television transmitting and receiving equipment.
Various types of images can be printed on the target electrode,
such as human figures, test charts, etc. When received, these
establish the fidelity of a television transmitter and receiver.
It is presumed that the reader is familiar with the fact that in
(Continued on page 757)
for April,
I
y
1LIGHT
MICRO
AMMETER
-I=
GLASS
ENVELOPE
/
O
BATTERY
CONDENSER FORMED
ON
REPRESENTING
EACH CELL
MOSAIC SCREEN
AMP.
m
/-
METAL
PLATE
OF THE
MOSAIC
M
OSAIC
CAESIUM
)
MICA
+
-
tl'I'I
A
=
CATHODERAY BEAM
6+_
h.
ELECTRON BEAM
CAMERA OBJECTIVE
MOSAIC
.j
(/'
et
The accompanying pictures show at
4-
SOURCE /LENS
ANODE
transmitting picture tubes.
A photo-deaf-if cell consists of
a cathode (coated with a photoelectric material, such as Caesium) and a positive electrode called
the anode, located in front of the photo -electric surface to collect
the electrons which are emitted from the cathode when light is
caused to fall on this sur face. Sec Figures 1 -A arc! I -P,.
The Iconoscope (Fig. 2 -:\) is a cathode -ray tithe in combination with a photo -electric screen consisting of millions of tiny
photo -electric cells. each cell constituting a condenser. This screen
is commonly referred to as a Mosaic screen. and when light is
caused to strike these tiny photo cells (or Mosaic). in the form
of an image, a charge of electrical energy is pick..d up by the
cells where the light of the image strikes. (See Fig. 2-B.) This
charge is discharged through the cathode heant as it traverse this Mosaic screen in the process of scanning point by peint
ELECTRON
FLOW
LIGHT
SILVER OXIDE CATHODE,
COATED WITH CAESIUM
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LIFlERS
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SWEEP SWEEP
TELEVISION
TRANSMITTER
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FREQ
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ELECTRO MAGNETIC
FOCUSING AND
DEFLECTING COILS
Jr
1
TO
AMPLIFIER
POWER
SUPPLIES
ELECTRONIC
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POWER
SUPPLIES
IMAGE
SHAPE OF SWEEP
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RETURN./
FM
725
1939
www.americanradiohistory.com
\X/orld Short Wave Stations
/evi:e4 G'GvHtrl
Complete List of SW
Broadcast Stations
Reports on station changes are appreciated.
Mc.
31.600
31.600
31.600
Call
WIXKA
WIXKB
W3XEY
31.600
W2XDV
31.600
W9XHW
31.600
W3XKA
Mc.
BOSTON, MASS., 9.494 m., Addr.
Westinghouse Co. Daily 6 am. -I
am.. Sun. 8 am. -I am. Relays
WBZ.
SPRINGFIELD, MASS., 9.494 m.
Addr. Westinghouse Co. Daily
6 an. -1 am., Sun, 8 am. -I am.
Relays WBZ.
BALTIMORE, MD., 9.494 m., Relays
WFBR 4 pm 12 m.
NEW YORK CITY, 9.494 m., Addr.
Col. Broad. System, 485 Madison
Ave. Daily 6 -11 pm.; Sat. and
Sun. 1.30 -6, 7 -10 pm.
MINNEAPOLIS MINN., 9.494
Relays WCCO 9 am. -12 m.
PHILADELPHIA, PA., 9.494
Addr. NBC. Relays KYW
IO
31.600
W5XAU
31.600
W4XCA
31.600
W8XAI
9
m.
m
arr.
pm.
OKLAHOMA CITY,
m., Su-.
9.494
12 n -I
pm., 6 -7 pm. Irregular
other times.
MEMPHIS, TENN., 9.494 m. Addr.
Memphis Commercial Appeal.
21.470
Call
GSH
DAVENTRY, ENG.,
21.550
21.450
Stromberg Carlson Co.
WHAM 7.30 -12.05 am.
31.600
31.600
W8XWJ
W9XPD
Relays
DETROIT, MICH., 9.494 m., Addr.
Evening News Ass'n. Relays WWJ
6 -12.30 am., Sun. 8 am 12 m.
LOUIS, MO., 9.494 m., Addr.
Pulitzer Pub. Co. Relays KSD.
ST.
26.550
W2XGU
NEW YORK CITY,
26.450
W9XA
KANSAS
W9XAZ
Co. Testing
MILWAUKEE,
WMCA.
CITY,
11.3
MO.,
m.
18.480
HS6PJ
HBH
m
WIS.,
11.36
m
Addr. The Journal Co. Relays
WTMJ from
pm.
NEW YORK, N. Y., 114 m., Addr,
Bamberger Broad. Service, 1440
Broadway. Relays WOR 12 n.
6 pr-.
SUPERIOR, WIS., 11.49 m. Relays
WEBC daily.
MINNEAPOLIS, MINN., 11.51 m
Relays WCTN 9 am. -I pm., 7 pm.-
W2XJI
26.100
W9XJL
26.050
W9XTC
12
26.050
25.950
W9XH
W6XKG
25.950
W9XUP
21.630
WIXAL
21.570
W2XE
21.565
DJJ
21.550
GST
21.540
W8XK
21.530
GSJ
21.520
W3XAU
BEND,
IND.,
Blvd. at Oak St. Relays KGFJ
24 hours daily. DX tips Mon.,
Wed. and Fri, 2,15 pm.
ST. PAUL, MINNESOTA. 11.56 m.
Relays KSTP evenings.
BOUND BROOK, N. J., 13.8 m.
Addr. N.B.C.. N. Y. C. 9 am. -4
Pm.
NEW YORK CITY, 13.91 m. (Addr.
CBS, 485 Madison Ave., N. Y. C.
Dail 7.30.10 am. Sat., Sun. 8
am. -I pm.
BERLIN,
GERMANY,
13.92
m.,
Addr. Broadcasting House, 6 -7.50
am.
DAVENTRY, ENG., 13.92 m., Addr.
(B.B.C., London)
Irregular at
Present.
PITTSBURGH, PA., 13.93 m., Addr.
Grant Bldg. Relays KDKA 6.45 -9
am. Also Sunday. 6 pm.
DAVENTRY, ENG., 13.93 m., Addr.
(See 21.550 mc.) 545 -8.50 am.
PHILA., PA., 13.94 rn., Addr.
Col. Broad. Syst., 485 Madison
Ave., N. Y. C. -2.30 pm.
1
21.500
W2XAD
SCHENECTADY, N. Y., 13.95 m.,
General Electric Co., 8 am. -12 n.
PRAGUE,
19.58 m.
Sun.,
CALIF.,
19.57
m.
CZECHOSLOVAKIA.
Addr. (See 11.840 Inc.)
Sat. 5 -5.10 pm.'
Wed.,
Mor., Tues., Thurs., Fri. 6.55 -9.55
15.77 m. Mondays 8 -10 em. See 15.23 mc.
15.320
OZH
15.310
GSP
15.300
YD8
15.300
XEBM
pm.
SKAMLEBAK,
DENMARK,
19.58
am. -1:30 pm.
DAVENTRY, ENG., 19.6 m., Addr.
(See 17.79 roc.) 3 -5.15 am., 1.45 -4
pm.
SOERABAJA, JAVA, N. E. I. 19.61
n. Addr. NIROM. 10 pm. -2 am.
MAZATLAN, SIN., MEX., 19.61 m.,
Sun.
8
Adds, Box 78, "El Pregonero del
Pacifico." Irregularly 9 -10 em.,
-'nard
'
BERLIN, GERMANY, 16.82 m., 10.35
am. -I pm.
17.820
2R08
ROME, ITALY. 16.84 m., Addr. (See
2RO, 11.81 mc.) 5 -7.30 am. Re:ays 2R0 to 6 pm. irregularly.
17.810
GSV
17.810
TPB3
DAVENTRY, ENGLAND, 16.84 m.,
5.45 -8.50 am., 12.20 -4 pm.
PARIS, FRANCE, 16.84 m. Addr.
(See 15.245 mc.) 9.30 -11 am.
17.800
01H
17.790
GSG
17.780
W3XL
-2, 8.10 pm.
ROME, ITALY. 19.61 m., Addr. (See
2R0, 11.81 rec.) 10 am. -2:30 pm.
DELHI, INDIA, 19.62 m., 9:30 -11:30
1
15.300
2R06
15.290
VUD4
15.290
LRU
15.280
DJQ
15.270
H13X
CIUDAD TRUJILLO, D. R., 19.65
m. Relays HIX Sun. 7.40.10.40 am.
15.270
W3XAU
PHILA., PA.,
15.270
W2XE
NEW YORK CITY,
pr,,.
17.770
LAHTI, FINLAND, 16.85 meters,
4.9 am.
DAVENTRY, ENG., 16.86 m., Adds.
B.B.C., London. 5:45 -8:50, 9 -1045
am., 12:20 -4 pm,
PH12
17.760
DJE
17.755
ZBWS
BOUND BROOK, N. J., 16.87 m.,
Addr. Natl. Broad. Co., 9 em.5 pm. to Europe, 5 -1I pm. to So.
Amer.
HUIZEN, HOLLAND,
16.88
m.,
Addr. (See PHI, 11.730 mc.) Daily
7:40.9:10 am. Mon S. Thurs. 7:409 a.m. Sun. 6:25 -9:45 am.
BERLIN,
GERMANY, 16.89 m
Addr. Broadcasting House. 12.05
5.50, 6.7.50 am.
HONGKONG,
Addr. P.O.
CHINA,
16.9
m.,
Box 200. Dly. 11.30
Pm.-I.15 am., 5 -10 am., Sun. 9
pm. (Sat) -I.30 am., 5 -9.30 am..
Operates irreg.
11.51
Addr. South Bend Tribure. Relays WSBT -WFAM 2.30.6.30 pm.,
exc. Sat. and Sun.
LOS ANGELES, CAL., 11.56
Addr. B, S. McGlashan, Wash,
OLRSB
am.
DJG
ro
SOUTH
FRANCISCO,
SAN
3 -9 a
e.
17.840
I
26.3x0
Call
W6XBE
m.,
u s
BANGKOK, SIAM,
VATICAN CITY, 16.81
2 n. on Wednesday.
HVJ
Addr. Commercial Radio Eqpt.
76.400
13.99
H o
/6 Met. Stoadcait Sand
17.845
Mc.
15.330
am.-
9
GENEVA, SWITZERLAND, 16.23 m.,
Addr. Radio Naticns. Sun., 10.45.
11.30 am.
Relays
11.33
GERMANY,
Broadcasting
12.05.5.30
19.020
5:45 -8:50,
(See
15.320
BERLIN,
Adds.,
DJS
Relays WMC.
ROCHESTER, N. Y., 9.494 m., Addr.
mc.),
m.
13.97
17.280
W2XGB
FZE8
15.550
CO9XX
15.510
XOZ
15.370
HAS3
15.360
DZG
15.360
-
HICKSVILLE, L. I., N. Y., 17.33 m.,
Addr, Press Wireless, Box 296.
Tests 9.30 -11.30 am. except Sat.
and Sun.
DJIBOUTI,
FRENCH
SOMALI.
LAND, 17.36 m. Test XMSN 1st
Thurs. each month 8.8.30 am.
Next B.C. April 6.
TUINICU, ORIENTE, CUBA. 19.29
Addr. Frank Jones, Central
Tuinicu, Tuinicu, Santa Clare.
Broadcasts irregularly evenings.
CHENGTU, CHINA, 19.34 m. Daily
9.45 -10.30 am.
BUDAPEST, HUNGARY, 19.52 m.,
Addr. Radiolabor, Gyali Ut 22.
Sun. 9 -10 em.
ZEESEN,
GERMANY, 19.53 m
Addr. Reichspostzerstralemt. Tests
'rregu la rly.
SWITZERLAND.
Irreg. 6.45 -7.45 pm.
BERNE,
19.53
m.
/9 Met. Stoadcajt Band
15.340
DJR
BERLIN,
Addr.
11
(See 21.570 r.c.)
1.30.2.30 pm.
15.260
15.7'0
W2XAD
GERMANY,
12.05-
SCHENECTADY, N. Y., 19.56
Addr. General Electric Co.
lays WGY, 12.15 -7 pro
m
P.e.
I
-3
Addr.
pm. Sat. 8
GS!
DAVENTRY,
ENG.,
19.66 m.,
pm.
BOSTON, MASS., 19.67 m.,
University Club. 2.3:30,
pm
ex. Sat. and Sun.
PARIS, FRANCE, 19.68 m.,
98 Bis. Blvd. Haussmann.
Mondial" 6 -11 am.
Addr.
1.30
15.250
WIXAL
15.245
TPA2
15.230
HS6PJ
15.230
OLRSA
15.220
PCJ2
Adds.
or 4
Adds.
"Paris
BANGKOK, SIAM,
19.7 m. IrreguMon. 8.10 em.
PRAGUE, CZECHOSLOVAKIA, 19.7
m. Addr. (See OLR4A. 11.84)
Mo-.. -Fri. 7.50 -10.55 pm. Set.,
and Sun. 5 -5.15 pm., Sun. 5.558.55 pm., Tues. 4.40-5.15 pm.
HUIZEN, HOLLAND, 19.71 m.,
'.I
Addr.
N. V. Philips' Radio Hilversum. 3.4:30 am. Tues., 9:30.
11:30 am. Weds. Daily 7.25 -8.25
am.
PITTSBURGH, PA., 19.72 m., Addr.
(See 21.540 mc.) 9 am: pm.
BERLIN, GERMANY,
19.74
m.,
Adds. (See 15.280
c.) 8 -9
4.50 -10.50 pm. Also Sun.
a
11.10 am. -12.25 pm.
ANKARA, TURKEY, 19.74 m., 5.307 am., 9.30 -II am.,
Relay. 2R0
irregularly Afts.
15.210
W8XK
15.200
DJB
15.195
TAO
15.190
OIE
LAHTI, FINLAND. 19.75 m. Addr,
(See OFD, 9.5 mcl. 1:05 -4 am, 9
15.190
ZBW4
HONGKONG, CHINA, 19.75 m
Addr. P. O. Box 200. Irregular.
I
am. -5 pm,
15.180
19.56
Br'dcast'g House,
19.65 m.,
(See 17.79 mc.) 3.5.15 am., 12.20-
15.175
am.
Tues. and Fri. 8.10 -10.10 pm.
19.65 m. (Addr. See
21.52 mc.) 3 -7 pm.
Sun
End of Broadcast Band
17.310
BUENOS AIRES, ARG., 19.62 m.,
Addr. El Mundo. Relays LRI,
7.9 am.
BERLIN, GERMANY,
19.63
m
Addr. Broadcasting House. 12.05II am. 4.50 -10.50 pm. Also Sun.
11.10 a. m. -12.25 pm.
15.170
11.30 pm. to 1.15 am., 3.10 am.
DAVENTRY, ENG., 19.76 m., Addr.
(See 17.79 mc.) 4.15 -6, 6.20 -8.30
p.m., 3 -5.15 am.
RV96
MOSCOW,
U.S.S.R.,
19.76
m.
Mon., Tues., Fri., Sat. 2.30 -3.30
pm. Daily 3 -4 em. Mon., Wed.,
Thurs. 7 -9.15 pm.
TGWA
GUATEMALA CITY, GUAT., 19.77
., Addr. Ministre de Fomento.
Daily 12.15 -1.15 pm.; Sun. 12.455.15 oro.
(Continued on pape 728)
GSO
All Schedules Eastern Standard Time
726
RADIO
www.americanradiohistory.com
&
TELEVISION
Let's
,....R.u.
R,o,oW:
X.r/
xa,Tw
, ,e
+n
Oìl w,4 el
fNO.
:1111
:long with this most
of seasons arrives the international
amateurs' DX contest, timed to take place when
DX conditions for worldwide reception on the
amateur hands. especially 20 meters. reach an
optimum.
Our interest. and that of most of DXers, will.
of course. be centered in the phone contest. which
is scheduled 'o begin on March 17. at 7:01 p.m.,
E.S.T.. and and on March 26 at 6:59 p.m.. E.S.T.
In these 9 days. it will Ix: possible to hear many
fine DX catches. as amateurs from all over the
world will participate and offer all UXers a grand
opportunity to add many fine DX logs to their
present total. A note here for C.W. UXers and
C.W. Hanes is that the code section of the
7:01
A.R.R.L. Cntest begins on March 3rd at p.m..
F.S.T.. and ends March 12th at 6:59
E.S.T
Last year we "cleaned up" on a good deal of
very fine 1)X. especially from Asia. using toa
\V8JK beam directed \orth over the Pole
cover the eastern half of Asia. and we do hope
that many f you Oil's have a similar beam antenna constructed. and measured for 20 meters. as
that will be the hand, and we would like to have
everyone ready to take the fullest possible advantage of the wealth of DX to he heard before.
during and after the contest.
Further particulars, as to when to tune for best
reception from each continent, etc.. Will be found
in our Ham Stardust column.
Again w' nmst mention the subject. a rather
important t ne for us S\VI: s. of QSI. cards. and
of correct reports. This seems to be a somewhat
sore topic for a number of DXers. but the necessity for some sort of a code of ethics for S\\'L's is
becoming more apparent than ever.
There is. for one thing, entirely too much of the
type of report being
"f heard you. psi QSL"tends
to give- them the
sent to amateurs, which
are ignorant boys
SW
L's
most
that
impression
who collet+ cards just for the fun of it. and are
not at all interested in giving the "pant' a report
of some value to hint. as to bow well his signals
came over. giving him a word-by word report of
his transmission, how good his modulation was.
what stations were QRM ing hint. and every other
detail one eunld ascertain of possible value to
the station being reported. The amateurs appreciate such reports very much indeed, and, judgA
a
y
S.
"
....
xC,AifD.
ONNTN. arlo,
ing from some of our replies, it would seem that
our retort, being fully detailed. was considered
exceptional. if only because of our pains to make
it complete.
So. fellows, let's work together. and do the right
thing. If you are making a report to a "ham:" do
ob as well as it can he done. or don't do
job
bugs, the
it at all. Try to give our brother radioDXers,
and
amateurs. a better impression of us
more
QSL's.
in
result
should
efforts
your combined
with
as there will be less amateurs "fed up"
the S I.'s reports.
a
A word about postage. If a DXer expects
card for his report. he not only should. he must
enclose a coupon with his report. Many "harts"
have ceased QS1-ing. due to the many reports
sent merely on cards. of course with no return
postage. Why should an amateur spend many
dollars monthly for postage to QSL S\ \'L s when
he can use that saute money to purchase some
much needed equipment.'
Dan Madan. ZS411. a popular amateur in South
Africa. whose phone signals are well known in the
States. writes us and requests us to publish his
plea that S\VL.'s enclose return postage if the
wish QSL cards. adding that lies "no millionaire."
Certainly. very few amateurs are! Dan has. like
the grand fellow he is, been sending his cards to
many SW L's who didn't send postage. when he
was in no way obligated to do so not counting
the many amateur contacts he had to QSI.. all
this running into quite some bill.
During the past month conditions have been
fair, but by March. DX should be very much
better. this month commencing the spring DX peak.
INDIA
\'UD4, on 15.29 roc.. Delhi, is a new addition
to the chain of excellent Asiatic broadcasters in
India. and may be heard almost daily between
9:30 -11:30 p.m.. E.S.T.. along with its sister
station. \'U1)3. 15.1(, mc.. but with different
programs on each. Reported by G. C. Gallagher,
and
I.D.A.
Also Masud Akhtar of New Delhi has been
kind enough to send along a late copy of the
"Indian Listener," an Indian radio magazine.
with the latest data on the 60 teeter band V U
Broadcasters.
Reallocations place the stations on these
new
freqs.: VUC2, 4.84; VUB_'. 4.88; VUDI2, 4.92
and V1.71/2. 4.96 inc..
these changes probably
December.
Regarding an item
here a few months
back anent the failure
of the Indian stations
CR7gt,
aytd
, ;...
-...,.-..
many
occasiona.
vit,: Ice
Fs7 67
sulttert sifty
aatte.
Thank You
v
Y1111r
Railway 7e1elre;;y,
Jpw 01d
at
Phwe,
on
SCR1'g
7ia..-.
to QSL reports. which
.
we personally
experienced along with
quite a number of our
reporters (but which
has evidently peen
since enrrectt,l ). OM
Masud tells us in his
interesting letter that
he made a personal
call to the offices of
Radio
All India
failure
was
(A.I.R.)
shown the tiles of rea it d
.
.
Rhodesia Railrays,
Líringatone,
7,
N. RhOdnSta,
"
VQ2PL Here's OM Peter at
home in this eternally verdant
land.
Cî71,
Z9,rD.
on 14.7;/8
ry ahrh
r
MC
J-
Ai..oj
A.R.g
Co.,OrT,oN
w, rra r,ylai.
¡
Vr 73
TentasaA,yars¡,
occurring during early
for Apri
HN
1-
FNOM
Revw'
IOI x........
NC
i.. jo...(.F..,?.....elb
/
Sumya,lilnmura,
..
.;t:17
Near
sOer
.
a.trnN
Look for Shigeo
this Spring. This red and white
QSL is well worth earning!
welcome
--
/
J3FI- JAPAN.
"DX" Editor
here.
B,ND
xw
T
VOL".
s
VwFONravScsRSr
19315
with
En
SPRING
,-...Q%.
i
l;aC /C
ov
Levnp..
ports front listeners.
all of whieh were
marked as answered.
fully satisfying Masud
that such a condition
no intierr exists.
Evidently our first
reports were received
before the station was
equipped to
fu l l y
handle reports, and
send confirmations. The Station Director assured
Masud that all reports will be answered. but that
listeners should send reply ostage. Many thanks
to you. Masud. for your FIT help!
ß'\1'V2. 17.51 mc. (taken from veri) Poona.
was heard during an inverted speech contact with
a Rugby fone at 8:15 a.m. recently.
Ví'62, 9.55 mc.. Bombay. and VUD3. are
reported from 10 -10:30 p.m.. with FB reception
by Daryl Sebastian, \ \'8.
IRAQ
The station lately reported as VIJG, this call
from an English listener. is proven to have the
call V I 5KG. and was mistakenly heard over the
kw.. is on the
air. VI5KG, on 7.20 mc.. with
air daily front 7:30 a.nt. -3 p.m.. one hour earlier
than previously reported. all this front an actual
veri received from Mr. I. Hassan.
Another transmitter of 400 watts is on 6.90 mc.
front 9:30 a.nt. onward; closing time not given.
but probably also 3 p.m. Another transmitter has
been ordered, and will be used as a commercial jolt.
This complete plant is owned by Iraq royalty.
H. R. H. Crown Prince Faisal Ghazi, and the
title of the broadcasting center is "Qasr el Zehoor"
Broadcasting Station. Baghdad. Iraq. Reports
may be sent to this QRA. or to that of the previous one recently given (S.\\-. DL, England).
1
ETHIOPIA
TA11A. 9.65 etc.. and known as "Stazione Di
Addis Abeba." in that city. is being operated by
the Italian Gov't from 11 a.m. 1 p.m. daily, rather
this tine African catch.
a difficult time to log
(I D.A.)
ALBANIA
ZAA. "Radio Experimental Tirana." at Tirana.
is reported as being on from 12:30 -2 p.m.. E.S.T.,
on 7.4875 me.. making it rather too early to be
well. if at all. in the U. S. Another
freq.. 9.9875 mc.. will also he used. both of these
freqs. being intended for European reception, and
15.765 mc., no schedule as yet, for America.
QRA (address) ZAA. Radio Exp. Tirana, Directorate General of Posts and Telegraphs. Tirana.
Albania. (I.D.A.) (S..\V.51.)
PHILIPPINES
KZIB. now 9.49 ntc.. Manila. moved from
9.503 mc. to avoid being QRDI'(d by VIC35IE. and
is heard daily 6 -9:05 a.in.. with good signal.
Ind.,
(I.D.A.) The QRA (address) is 1.440.BeckManila,
Crystal Arcade Bldg.. P.O. Itox
heard
Y.I.
KZRDI, 9.57 me., Manila, is reported being
operated by a new organization "the Far Eastern
Broadcasting Co., and owned by same. per W. G.
Layton, from a recent veri. Schedule is: Mott. -Fri.:
4:30 -6 p.m.. 5 -9 a.m.; Sat.: 4:30 -6 p.m.. 5 -10
a.m.. and Sun.: 4.10 a.nt. He also reports ICZIB.
EZGF. 5.47 mc.. Manila. reported phoning
} ZGH. 5.44 mc.. Iloilo, near 9 a.nt., often, by
Jack Hartley, \\-2.
CHINA
XGRV, reported on 11.38.11.42 mc.. Chungking. the wartime capital being its location. according to a letter received by Jack Wells. \V4,
from II. F. Tong. Schedule is given as -1:35
a.m.. when news is given in Chinese and Japanese.
and 8 -8:35 a.m., when it is given in English and
French.
Mr. Tong. who is Chairman of the China Information Committee, Y.O. Box 90. Hankow. states
that XTJ. replaced by XGRV. has been moved to
the interior to avoid damage from war activities.
G. C. Gallagher. W6. reports XGRV.
XGRV. 15.19 etc.. Chungking, is reported irregular 7 -9 p.m. (I.D.A.)
XGAP. 9.56 mc.. Peking. is heard 4.9 a.m.,
daily, and QRA is: S. Yoshi:mira. Director Peking
Peking.
Hsi -chap -an- Chien.
Station.
[Central
(Continued on page 759)
1
727
1939
www.americanradiohistory.com
Mc.
Call
OSLO,
15.160
XEWW
ported Suns. 10.30 am. on.
MEXICO CITY, MEXICO, 19.79 m.,
12 n. -12 m.,
irregular.
15.160
VUD3
15.155
SMSSX
15.150
YDC
NORWAY,
m.
19.78
Re-
15.120
SP19
DELHI, INDIA, 19.79 m., Addr. All
Radio. 1.303.30 am., 9.301'.30 pm.
STOCKHOLM, SWEDEN, 19.79 m.,
Daily II am.-5 pm., Sun. 9 am..
5 pm.
BANDOENG, JAVA, 19.8 m., Addr.
N. I. R. O. M. 6 -7.30 pm., 10.30
pm. -2 am., Sat. 7.30 pm. -2 am.,
daily 4.30 -10.30 am.
DAVENTRY, ENG., 19.82 m., Addr.
(See 17.79 mc.) 3 -5.15 am., 5.45
f.50 am., 9 am. -noon.
PARIS, FRANCE. 19.83 m., Addr.
"Pans Mondial," 98 Bis Blvd.
Haussmann, 7 -9.15 pm.
BOSTON, MASS., 19.83 m., Addr.
World -Wide B'cast'g
Founda.
tion. University Club. 10 -11 am.,
Mon. -Fri, Sun. 10 am..1 pm.
WARSAW, POLAND, 19.84 m.. 6.9
15.120
HVJ
VATICAN CITY,
15.140
GSF
15.130
TPB6
-
15.130
WIXAL
pm.
DJL
BERLIN,
GERMANY,
Addr. (See
em.,
Sur., also
8.9
15.080
14.960
14.940
PSE
14.920
KQH
14.600
JVH
14.535
HBJ
HCIJB
14.166
PIIJ
13.997
EA9AH
SPW
19.85
m.,
mc.) 12.05 -2,
15.280
10.35
am. -4.25
pm.
KAHUKU, HAWAII,
11
20.11
m. Sats.
12.862
W9XDH
12.486
HIN
12.235
TFJ
12.200
12.000
RNE
11.885
TPB7
Works Europe 4 -8 am.
GENEVA, SWITZERLAND, 20.64 m..
Addr. Radio Nations. Broadcasts
Sun. 10 45 -11.30 am., Mon. 4 -4.15
am.
RADIO MALAGA, SPAIN, 20.78 m.
Relays Salamanca 5.40 -8.40 am.
Sometimes 2 -4 pm.
QUITO, ECUADOR, 20.79 m. 10,0.30 cm. except Mon. 9 -9.30
pm. and irreg.
DORDRECHT, HOLLAND, 21.15 m.,
Addr. (See 7.088 mc.) Sat. 12 n.
12.30 pm.
TETUAN, SPANISH MOROCCO,
WARSAW, POLAND,
pm, Sat.
& Sun.
22 m. Daily
6-9 pm.
ELGIN, ILL., 23.32 m. Press Wireless, Tests 2 -5 pm.
TRIJILLO CITY, DOM. REP., 24.03
-^. 7.10 -10.'0 pm.
QUITO, ECUADOR, 24.08 m. Daily
exc. Mon. 8 -10.30 pm.
REYKJAVIK, ICELAND, 24.52 m.
Works Europe mornings. Broad.
casts Sun. 1.40 -2.30 pm.
TRUJILLO, PERU, 25. m., "Rancho
Grande."
Address
Hacienda
Chiclin. Irregular.
MOSCOW, U.S.S.R., 24.88 m. Daily
6.7 am., 12 n..2 pm., 3 -6, 10.15 -11
11.990
CB1180
11.970
HI2X
CIUDAD TRUJILLO, D. R., 25.07
m., Addr. La Voz de Hispaniola.
Relays HIX Tue. and Fri. 8.10
10.10
11.880
-
W8XK
11.870
11.865
11.860
VLR3
GSE
DJP
11.850
C81185
11.850
OAX2A
I1.640
KZRM
11.840
CSW
11.840
OLR4A
11.830
W9XAA
11.830
W2XE
11.826
XEBR
G5N
11.810
2R04
11.805
OZG
11.801
DJZ
11.800
COGF
11.800
JZJ
11.795
DJO
11.790
WIXAL
11.780
HP5G
11.780
OFE
11.770
11.760
11.760
11.935
T12XD
SAN JOSE, COSTA RICA, 25.
11.910
CDI190
VALDIVIA, CHILE,
La Voz
10
a
Box
pm.,
..
del Pilot. Apartado
4 -10
DJD
TGWA
642. Relays
7 -10 pm.
25.2 m.,
CB69
10
XETA
11.760
OLR4B
I1.750
GSD
2
1729.
pm.
P.
0.
am. -I
2 -5
am.,
Addr.
11.15
SP25
11.740
COCX
11.740
HVJ
11.730
PHI
11.730
WIXAL
11.730
LKQ
11.720
CJRX
Sat, and Sun. 9 -11 pm.
OSLO, NORWAY, 25.58 m. 4.30 -9
Suns. 2.309 am.
WINNIPEG, CANADA, 25.6 m.,
Addr. James Richardson & Sons,
Ltd. Daily 6 pm. 12 m., Sat. 6
pm. -Sun. 4 am.
11.720
ZP14
VILLARICA, PARAGUAY, 25.60 m.
11.718
CR7BH
LAURENCO
PARIS,
FRANCE, 25.24 m. (See
mc.) 9.30 pm. -mid., 12.15am. Irregular.
MELBOURNE, AUST., 25.25 m.,
3.30-7.15 pm., 9 pm..3 am. week.
days. Suns. mid. -3 am.
PITTSBURGH, PA., 25.26 m., Addr.
(See 21.540 mc.) -11 pm.
BERNE, SWITZERLAND. 25.28
I
Irreg. 8-9 pm. to No. Amer.
m.
DAVENTRY, ENG., 25.30 m., Addr.
(See 11.75 mc.) 3 -5.15, 5.45 am.10.30 am. Sun. 1.1.30 pm.
BERLIN, GERMANY,
25.31
m..
Addr. (See 15.280 roc.) Irregular.
7.15 -10.50 pm. for No. Amer.
SANTIAGO, CHILE, 25.32 m. Sat.
6.11 pm. and irreg.
TRUJILLO, PERU, 25.32 m. Testing
on this free. (See 12.200).
MANILA,
I
P.
25.35
m.
Addr.
Erlanger & Gallinger, Box 283.
9 pm. -10 am. Irregular.
LISBON, PORT., 25.35 m. Nat'l
Broad. Station. 11.30 am,1.30
pm. Irregular.
PRAGUE, CZECHOSLOVAK IA, 25.34
rn., Addr. Czech Shortwave Ste.,
Praha XII, Fochova 16. Daily
1.55 -4.30 pm. Mon. to Fri. 7.5510.55 pm., Sun. 5.55 -8.55 pm.
CHICAGO, ILL., 25.36 m., Addr.
Chicago Federation of Labor.
Irregular 7 am. -6 pm.
NEW YORK CITY, 25.36 m., Addr.
Col. Broad. System, 485 Madison
Av..
N.Y.C. Mon. -Fri. 3.306
6.30 -10 pm. Sat., Sun. 3 -6. 6.30.
pm.
HERMOSILLA, SON., MEX., 25.37
m., Addr. Box 68. Relays XEBH.
9.30 -11 am., -4 pm., 9 pm. -12 rr.
DAVENTRY, ENG., 25.38 m., Addr.
(See 11.75 mc.) Irregular.
ROME,
ITALY, 25.4 m., Addr.
E.I.A.R., Via Montello 5. Daily
4.40 -8.45 am., 10 am. -12 n.
SKAMLEBAK.
DENMARK,
25.41
m. Addr. Statsradiofonien, Irreg.
BERLIN, GERMANY, 25.42 m. 4.5010.50 pm.
MATANZAS, CUBA, 25.42
Addr. Gen, Betancourt 51. Relays CMGF. 2.3. 4 -5, 6 pm. -Mid.
TOKYO, JAPAN, 25.42 m., Addr.
Broadcasting
Co. of Japan,
Overseas Division. 7 -730, 8 -9.30
am., 2.30 -4, 4.30 -5.30, 8 -8.30 pm.,
12.30 -1.30 am.
BERLIN, GERMANY, 25.42 m. 4.50
Addr. (See 15.280 mc.) 11.30
am. -4.25 pm., 4.50 -10.50 pm. Irregular.
BOSTON, MASS., 25.45 m.. Addr.
(See 15.250 mc.) Daily 4.55 -6.30
pm., Tues., Thur., 4.40-6.30 pm.,
Sat. 1.45 -6 pm -, Sun. 5 -6.30 pm,
PANAMA CITY, PAN., 25.47 m
Addr. Box 1121. 6 -10 pm.
LAHTI, FINLAND. 25.47 m. Addr.
(See OFE, 9.5 mc.) 1.05 -3 am.,
5.6.20, 10 am. -12.30 pm.
BERLIN,
GERMANY, 25.49 m.,
Addr. (See 15.280 mc.) 11.30 am.4.25 pm., 4.50.11 pm.
GUATEMALA CITY, GUAT., 25.51
m. (See 17.8 roc.) Irregular 1011.30 pm. Sun. 6 -11.30 pm., irregular,
MONTEREY, MEX. 25.51 m., Addr.
Bon 203. Relays XET, n. -3.30 pm.
and evenings.
PRAGUE, CZECHOSLOVAKIA,
25.51 m.. Addr. (See 11.840 mc.)
Irregular.
DAVENTRY, ENG., 25.53 m., Addr.
B.B.C., London, 3.5.15
9
.noon. 12.30 -6 pm., 6.20.9.30
BOSTON
MASS., 25.57 m., Addr.
World -Wide B'cast'g Foundation, University Club. Daily exc.
9.70.11 70
r^.
o..
7.07 -9.07
GUESE
12.05 -1,
12.05 -4
pm.
2
11.715
TPA4
PARIS,
15.245
(2
11.710
11.710
YSM
n.
MARQUES,
-
FRANCE, 25.61 m.. (See
mc.) 7 -9.15 pm., 9.30 pm.to No. America.
1
11.705
SIP
11.700
HP5A
8 -9 pm.
PANAMA CITY, PAN., 25.65 m.
Addr. Radio Teatro, Apartado
954.
10
am. -I pm.,
5 -10
6.10 pm,
11.700
PORTU-
AFRICA, 25.6 m. Daily
4.30 -6.30,
9.30 -11
am.,
pm., Sun. 5.7 am., 10 am:
E.
SAN SALVADOR, EL SALVADOR,
25.63 m., Addr. (See 7.894 mc.)
2.30 pm.
SAIGON, FRENCH INDO- CHINA.
25.62 m., Addr. Boy -Landry, 17
Place A Foray. 7.30.9.15 am.
MOTALA, SWEDEN, 25.63 m., 1.202.05, 6 -9 am., 11 am. -I pm., Sat.
1.20 -2 am., 6 am. -I.30 pm., Sun.
3 am. -1.30 pm. Wed. and Sat.
CBI I70
pm. Sun.
SANTIAGO, CHILE,
25.65 m. Addr.
P.O. Box 706. Relays CB89 10
am. -2 pm., 3.30 -11 pm.
End of Broadcast Band
11.676
IQY
11.535
SPD
11.402
HBO
11.040
CSW2
11.000
10.950
ROME, ITALY. 25.7 m. Relays 2R0
1.35 2.25, 6 -9 pm.
WARSAW, POLAND, 26.01 m.,
Addr. 5 Mazowiecka St. 6.9 pm.
GENEVA, SWITZERLAND, 26.31 m.,
Addr. Radio Nations. Sun. 7 -7.45
pm., Mon. 1.1.15 am., 7 -8.30 pm.
LISBON, PORTUGAL, 27.17 m
Addr. Nat. Broad. Sta. 9.30 am.Noon. 2 -5.30 pm.
BANDOENG, JAVA, 27.27 m. Relays YDB. 6 -7.30 pm., 10.30 pm:
2 am., 4.30 -10.30 or II am. Sat.
until 11.30 am.
TANANARIVE, MADAGASCAR,
27.40 m.. Addr, (See 9.38 mc.)
PLP
-
12.30 -45,
1011
am.,
2.30 -4
exc. Sun.
am.,
10.670
CEC
10.660
JVN
10.600
ZIK2
SANTIAGO, CHILE, 28.12
m.
Irregular.
NAZAKI, JAPAN, 28.14 m. Broadcasts daily 1.50.7.40 am. Works
Europe irregularly at other times.
BELIZE, BRIT. HONDURAS, 28.30
10.535
JIB
TAIHOKU,
10.400
YSP
10.350
LSX
Works Japan around 6.25 am.
Broadcasts, relaying JFAK 9.05.10
am., -2.30 am. Sun. to 10.15 am.
SAN SALVADOR, EL SALVADOR,
28.85 m.,
-3, 6.30.11 pm.
BUENOS AIRES, ARG., 28.98 m.,
Addr. Transradio International,
10.330
ORK
10.290
TIEMT
10.290
DZC
10.260
PMN
10.220
PSH
-
r.r
WARSAW, POLAND, 25.55 m., 69 pm.
HAVANA, CUBA. 25.55 m. P. 0.
Box 32. Daily 8 am. -I am. Sun.
8 am. 12 m. Relays CMX.
VATICAN CITY, 25.55 m. Tasting
regular. Wed. 2.30 -3 pm.
HUIZEN, HOLLAND, 25.57 m.,
Addr. N. V. Philips' Radio. Daily
6.15.6.45 pm. Sat. 7.15.7.45 pm.
p'....
1
11.820
pm.
25 /H¢t. iltoadca3t iland
roc.)
15.245
Call
11.740
15.245
pm.,
aiso Tues., Thurs. 8.30 -9
Om., also Sun. 6 -10.30 am., 12 r..
5 pm., 6 -6.30, 8.30 -9, 10.15 -11 pm.
SANTIAGO, CHILE, 25.02 m. 7 -11
Pm.
PARIS, FRANCE, 25.24 m.,
2
-11.30 pm.
NAZAKI, JAPAN, 20.55 m. Broadcasts
irregularly 5 -11.30 pm.
4.15 am., 7 -9.30 am., 150 watts.
MEXICO CITY, MEXICO, 25.21 m.,
Addr. P. 0. Box 2874. Mon.,
Wed., Fri. 3 -4 pm., 9 pm. -12 m.
Tues. and Thur. 7.30 pm. -12 m..
Sat. 9 pm. -12 m, Sun. 12.302
o^r.'6
-I.30
MOSCOW U.S.S.R., 20.25 m., 1st
of month, 6 pm. Dutch program.
RIO DE JANEIRO, BRAZIL. 20.08
m., Broadcasts Wed. 3.45 -4.15
6 -8
HC2JB
TPA3
Mc.
HANOI, FRENCH INDO- CHINA.
25.21 m. ''Radio Hanoi ", Addr.
Radio Club de l'Indochine. 3.45
(See
10.30I
21.43 nr. Apartado 124. 5.15.6.15
Pm., 6.30 -7.30 pm., 9 -10 pm. Re',vs Salamanca from 5.40 pm.
12.460
11.885
XEWI
End of Broadcast Band
14.430
13.635
11.900
-
6 -8
-1.30 am.,
14.440
11.900
11.855
m.,
Suns.
pm.,
am.
MOSCOW,
U.S.S.R.,
19.87
m.
Works Tashkent near 7 am. Broadcasts Sun. 12.15 -2.30 pm. Daily
7.9.15 pm.
RKI
-
19.83
Les only.
am..
_.45
15.110
Call
Mc.
LKC
15.166
m., Tue., Thurs., Sat.
9
1.30 -2, 8.30-
pm.
TAIWAN,
28.48
ro
I
I
Tests
irregularly.
BELGIUM, 29.04 m.
Brcadcasts 12.302 pm. Works
OPM 1.3 am., 3 -5 pm.
SAN JOSE, COSTA RICA, 29.15
m., 4.308 pm.
ZEESEN, GERMANY,
29.16 m.,
Addr. (See 15.360 mc.) Irregular,
RUYSSELEDE,
BANDOENG, JAVA, 29.24 m. Relays YDB 6 -7.30 pm., 10.30 pm.2 am.. 4.30 -10.30 or II am., Sat.
to 11.30 am.
RIO DE JANEIRO, BRAZIL, 29.35
m.. Addr. Box 709. Broadcasts
6.7 om.. Mon. 8 -8.30 pm.
(Continued on pane 730)
All Schedules Eastern Standard Time
728
RADIO
www.americanradiohistory.com
&
TELEVISION
7QIIL4
SILVER TROPHY
Avatd
For Best HAM Station Photo of the Month
Awarded to X. W.
"god' Preston,
W9VXL
Savanna, III.
is a photo of myself and
station for your contest. \ly transmitter
is a Collins 301:XB with sonie alterations
of my own. The receiver is a Patterson
PR15.
I built a rim R.4 unit and a new power
supply for the final stage. I run either 250
or 400 watts phone and prefer the ten
meter band. The tube lineup in the new R.F.
unit is a 42 oscillator, 807 doubler, 809
buffer and a T125 final.
The speech lineup is a Shure 701A mike
into the standard Collins 7C speech amplifier, driving a pair of ZI-1120's Class "B."
The remote control box on the desk contains the filament. plate, stand -by and push to- talk switches. The switches on the transmitter panel provide a means of applying
plate voltage to each stage individually
when tuning up. The antenna used for ten
is a rotatable Johnson Q and reflector. The
control wheel may be seen on the left -hand
corner of the desk. An antenna changeover relay shifts the beam from the transmitter to the receiver, which is a PR15.
The room measures eleven by twelve
feet and is built into one end of the attic.
It is constructed of heavy celotex and has
double walls to provide a dead air space.
The floor is covered with an insulating material under the carpet. The room is perfectly sourd -proof and DX contacts may be
held at any time of day or night.
HERE\WITH
Thirty -nine countries have been "worked"
in the six months I have been on the ten
meter band.
In closing, let nie congratulate and thank
you for a very fine magazine. I have every
issue from 1934 and refer to them many
times.
Sincerely yours.
L. W. "BUD"
TELEVISION magazine for the best photo of a
Ham station. The silver statue stands on a
handsome bakelite base on which is a silver
plate. The name of the winner w'll be engraved
on this plate before the trophy is sent to him.
Silver Trophy Award
Note These Important Rules
The photos must he sharp and clear and preferably not less than 5" x 7 ".
The pictures will be judged for the general layout of the station, the quality of workmanship
exhibited. and the appearance of the photograph
itself. The judges will also consider neatness as an
important point.
When you submit the photograph of your Ham
station. send along a brief description not longer
than 300 words, describing the general line -up of
-L.
1939
W9VXL,
Savanna, Ill.
This beautiful silver trophy stands 113/4" high
and one is awarded monthly by RADIO &
Prize-Winning "Ham" Station this month
for Apr'I,
PRESTON,
W. Preston, Savanna, III.
the apparatus employed. the size. type and number
of tubes. the type of circuit used. name of commercial transmitter --if not home -made. watts rating
of the station. whether for c.w. or phone or both.
etc., also name of receiver.
State briefly the number of continents worked.
the total number of stations logged or contacted,
and any other features regarding the station which
you think will he of general interest to the reader.
'Mention the type of aerial system used. especially
any unique or new features about it. and which
type of aerial yoti use for transmitting and receiving; also what type of break -in relay system. if
any, is used.
Important-Don't forget to send along a good
photograph of yourself. it your likeness does not
already appear in the picture!
Note that you do not have to be a reader of
RADIO & TELEVISION in order to enter the contest.
Pack all photographs carefully and the description
had best be mailed in the sante package with the
photos. The Editors will not be responsible for
photos lost in transit.
Do not send small. foggy -looking photos because
they cannot be reproduced properly in the magazine. If the picture you have or may take of
your station is not thoroughly sharp and clear and
at least 5" x 7 ". it would be best to have a commercial photographer take a picture of your station.
If you cannot do this, you most probably have a
friend who owns a gond camera and who can
arrange to take the photograph. You are not limited
to one picture, but may submit as many different
views as you like.
Address all photos and station descriptions to
Editor, Ham Station Trophy Contest, c/o RADIO &
TELEVISION, 99 Hudson Street, New York. N. Y.
729
Mc.
10.100
10.042
9.955
-
Call
DZB
COBC
9.607
9.600
RAN
30.02 m.,
Addr.
9.595
Relays
CMBC
HBL
9.590
VU D2
regular.
HAVANA, CUBA,
0. Box 132.
6.55 am. -I am.
P.
9.920
9.892
JDY
CPI
Call
Mc.
DEUTSCHE FREIHEITS SENDER,
29.70 m., loc. in Germany, undercover. 4 -5 pm.
ZEESEN,
GERMANY, 29.87 m.,
Addr. Reichspostzenstralamt. Ir-
DAIREN, MANCHUKUO, 30.24 m.
Relays JOAK daily 7.8 am. Works
Tokyo occasionally in early am.
SUCRE, BOLIVIA, 30.33 m., 11 am.7.9 pm.
MADRID, SPAIN, 30.43 m., Addr.
Post Office Box 951. 7.30 -8, 8.40.
9 pm.
ROME, ITALY, 30.52 m. Works
Egypt afternoons. Relays 2R0,
6 -9 pm.
HAVANA, CUBA, 30.60 m. Addr.
Transradio Columbia, P. 0. Box
33. 8 -1 am, Relays CMCM.
HP5J
9.830
9.805
9.760
9.753
FAQ
IRF
COCM
ZRD
SAIGON, INDO- CHINA, 30.72 m.,
Addr. 17, Place A. Foray. "Radio
Boy -Landry." Heard 6 -9.15 am.
DURBAN, SOUTH AFRICA, 30.75
m. Addr. S. A. Broadcasting
Corp., P. 0. Box 4559, Johannesburg. Daily exc. Sat. 11.45 pm.12.50 am. Daily exc. Sun. 3.307.30, 9 -11.45 am., Sun. 5.30 -7, 9.
11.30 am., also 4.5 am. on 3rd
Sun. of month.
9.735
CSW7
LISBON,
PORTUGAL,
9.590
PCJ
9.708
COCO
6 -9 pm. for No. Amer.
HAVANA, CUBA, 30.90 m. Addr.
25 No. 445,
Vedado, Havana,
7.1
9.690
-
9.690
TI4NRH
LRA
9.685
TGWA
9.680
ZHP
9.675
DJ%
9.670
W3XAL
9.665
-
9.660
9.650
9.650
9.645
LRX
W2XE
CS2WA
Ht-13W
HEREDIA, COSTA RICA, 30.94 m.,
Addr. Amando C. Marin, Apartado 40. Sun. 7 -9 am., Tues.,
Thurs., Sat. 9.10 pm.
BUENOS AIRES, ARG., 30.94 m.,
6 -9 pm.
GUATEMALA CITY, GUAT., 30.96
m. Daily 10 -11.30 pm.; Sun. 710.45 pm.
SINGAPORE, MALAYA. 30.98 m.
Sun. 5.40 -9.40 am., Wed. 12.401.40 am., Mon. -Fri. 4.40 -9.40 am.,
Sat. 12.25 -1.40 am., 4.40 -9.40 am.,
10.40 pm. -1.10 am. (Sun.)
BERLIN,
GERMANY, 31.01
Addr. (DJD, 11.77 mc.) 10.35
am. -4.25 pm.
BOUND BROOK, N. J., 31.03 m.
Addr. NBC, N. Y. C. 5 pm. -I a--.
ROME, ITALY. 31.04 m. Relays 2R0
12 n. -6. 7.30 -9 om.
BUENOS AIRES, ARG., 31.06 m.
Addr. El Mundo. Relays LRI,
6 -6.45 am, 9.15 am: 10.05 pm.
NEW YORK CITY, 31.09 m. (See
21.570 mc. for addr.) 10.30.11.33
om. exc. Sat. and Sun.
LISBON, PORTUGAL, 31.09 m.,
Addr. Radio Colonial. Tues..
Thurs. and Sat. 4 -7 pm.
PORT -AU- PRINCE, HAITI, 31.1 m.,
P.
0.
9.635
JFO
2R0
HJ7ABD
A117.
I
-2,
7.9
ROME,
VK2ME
9.590
W3XAU
Call
OZF
SKAMLEBOAEK,
9.580
GSC
9.580
VLR
ergsgade
9.520
YSH
9.510
GSB
9.570
KZRM
MANILA,
WIXK
3 -10
am. Daily exc. Sat.
4.30-7 pm., 11.15 pm. -12.15 am
Daily exc. Sun. 4 -10 am.
BOSTON,
MASS.,
31.35
m.
I.
P.
Copenhagen, 8 -9.30,
9.30 -II pm. to No. Amer.
SAN SALVADOR, EL SALVADOR
31.51 m., Addr. (See 7.894 mc.)
Irregular 6 -10 pm.
DAVENTRY, ENGLAND, 31.55 m.,
Addr.
9.510
HJU
9.510
HS6PJ
9.510
-
9.503
KZIB
9.503
XEWW
9.500
VK3ME
9.500
OFD
9.490
OAX5C
9.488
EAR
Erlanger
Galinger,
&
Box
9.465
TAP
283.
9.560
XGAP
am. -I am.
PEKING, CHINA, 31.38 m.,
9
am.-
2
9.560
DJA
BERLIN,
GERMANY,
31.38
Addr. Broadcasting House.
9.550
HVJ
9.550
TPBII
9.550
W2XAD
9.550
OLR3A
-
PRAGUE,
31.41
CZECHOSLOVAKIA,
11.840 mc.) Mor.
m. (See
XEFT
VERA CRUZ, MEX., 31.41
am. -4.30
a
9.550
YDB
m.
SOERABAJA,
m. 10.30
pm. -12.30
10.30
pm.,
JAVA,
m.
31.41
Addr. N.I.R.O.M. Daily exc. Sat.
9.550
VUB2
9.540
9.538
DJN
HJ5ABD
VPD2
COCH
HAVANA, CUBA,
2 B St., Vedado.
9.380
-
TANANARIVE, MADAGASCAR,
8.15.10.15 pm..
Sun.
7
am. m.,
JZI
9.535
-
Sat- to
Re-
9.530
W2XAF
BUCARAMANGA, COL.,
11.30 am. -I
31.14
pm.,
m.
6 -11
VUC2
9.526
XEDQ
9.370
XOY
9.355
HCIETC
9.350
COCD
9.345
HBL
GENEVA, SWITZERLAND 32.11 m.,
Addr. Radio Nations. Sun. 8 -8.45
Mon. 6.45 -8.30 pm.
9.340
OAX4J
LIMA,
HJIABP
CARTAGENA,
COL., 31.20 m.,
Addr, P. O. Bon 37. Daily 9 a^ .
30 pm., 4.30 -10.15
pm..
S .4.30 -9 pm.
KLIPHEUVAL, SOUTH AFRICA.
1
9.526
ZBW3
9.615
ZRK
31.2
.
m.,
Addr,
P.
0.
Box
4559
Johannesburg. Daily, exc. Sat.
11.45 pm. -12.50 am. Daily exc.
Sun. 3.20.7.20. 9 -11.45 am., Su-.
3.30 -4.30 or 4 -5, 5.30 -7, 9 -11.45
3
am.
9.523
LKC
ZRH
pm.,
5
pm. -I am.
SHANGHAI,
XGX
CHINA, 32.26 m.,
89.05 am. Varies between 9.180-
BOMBAY, INDIA. 31.41 m., Addr.
All India Radio. 9.30 -10.30 pm.,
-3.30 am.
BERLIN,
GERMANY, 31.45 m.,
Addr. (See 9.560 mc.) 12.05 -11
am. 4.50 -10.50 pm. to So. Amer.
9.300
CALI COLOMBIA,
La Voz de Valle.
9.200
COBX
11.40 am. -2.10
pm., 3.40.9.40 pm.
HAVANA, CUBA, 32.59 m. Addr.
9.165
HC2CW
GUAYAQU IL,
9.125
HAT4
BUDAPEST, HUNGARY,
9.300.
31.45 m.,
Addr.
n. -I.30
12
5.109.40 pm.
SUVA, FIJI ISLANDS,
31.46
9.300
HIG
CIUDAD TRUJILLO,
Sun.
CMBX
22.
9.100
COCA
9.091
PJC2
31.46 m.,
-2
HONGKONG, CHINA,
Addr. P. O. Box 200.
31.49 m
11.30 pm.
to
am., 3 -10 am.
JELOY, NORWAY, 31.49 m., 4.3010.30 am., Sun. 2.30.10.30 em.
ROBERTS HEIGHTS, S. AFRICA.
31.5 m., Addr. (See ZRK, 9.606
mc.) Daily exc. Sun. 5 -7.30 a.m.'
Sun. 5.307 am.
32.28
194,
Altos.
Relays
7
Addr.
m., Addr.
2.30.4, 4.30
pm. exc. Mon. and Tues.
SCHENECTADY, N. Y., 31.48 m..
Addr. General Electric Co. 4
pm. -12 m. Sat.
pm. -12 m.
CALCUTTA, INDIA. 31.48 m. Addr.
Al India Radio. 2.06 -4.06 aGUADALAJARA, GAL., MEXICO,
31.49 ro., n. -4.30 pm., 8.11.30 c
R.,
am. -12 m.
ECUADOR, 32.74
7 -11.30 pm., Sun. 3.30 -6 pm.
.,
TOKYO, JAPAN, 31.46
(See 11.800, JZJ)
5.30 pm. 8 9 37 am.
BERNE, SWITZERLAND,
Miguel
San
pm.,
m
D.
m. 7.10 -9.40 am.,
32.88 m.,
Gyali -ut,
Sat., 6 -7 pm.
" Radiolabor,''
Daily
7 -8
pm.,
HAVANA, CUBA, 32.95 m., Addr.
Galiano No. 102. Relays CMCA
9 am. 12 m.
CURACAO, D. W. INDIES, 33
., 6.36 -8.36 pm., Sun. 10.36
2.36 pm.
am:
9.030
COBZ
HAVANA, CUBA, 33.32 m., Radio
Salas Addr. P. 0. Box 866. 7.45
am. -I.15 am. Sun. 7.45 am.-I2 m.
8.965
COKG
SANTIAGO, CUBA,
Relays CMBZ.
Box
137. 9 -10
pm.,
I
9.525
Addr. Box
"Radio Universal." 12 n:
PERU, 32.12 m.,
1166,
'
9.618
Addr. Le Directeur des
Radio Tananarive, AdminisPTT. 12.30 -12.45, 10 -II am.,
2.30 -4 am., exc. Sun.
CHENGTU, CHINA, 32.02 m.,
9.45 -10.30 am.
QUITO,
m.,
ECUADOR, 32.05
Addr. Teatro Bolivar, Thurs. un.I 9.30 pm. 8 -1I pm. Sets.
HAVANA, CUBA, 32.08 m., Addr.
Box 2294. Relays CMCD 10 a.m.11.30 pm. Sun. 10 am. -9 pm.
PTT,
1
9.530
am. -12 m.
8
tration
4.30 -11.30 am.
1
ITALY, 31.13 m., Addr.
mc.) 12.05 -9 pm.
exc. Sun.
31.8 m
Addr.
8 am. -9.30 pm.
31.96 m.
6.7.30 pm., 4.30 to 10.30 am. Sat.
Australasia, Ltd. 5.30 -7 am., exc.
9.535
BUENAVENTURA, COLOMBIA,
31.55 m., Addr. National Railways. Mon., Wed. and Fri. 8pm.
BANGKOK, SIAM, 31.55 m. Thursday, 8 -10 am.
HANOI, FRENCH INDO- CHINA.
31.55 m. "Radio Hanoi ", Addr.
Radio Club de L'Indochine. 12
m. -2 am., 6 -10 am. 15 watts.
MANILA, PHIL. ISL., 31.57 m.,
7.9.05 am.
MEXICO CITY, MEX., 31.57 m.
Addr. Apart. 2516. Relays XEW.
9 am..12.30 am.
MELBOURNE, AUSTRALIA, 31.58
m., Addr. Amalgamated Wireless
of Australasia,
167 Queen St.
Daily except Sun. 4.7 am.
LAHTI, FINLAND, 31.58 m., Addr.
Finnish Brest. Co., Helsinki. 12.155 pm.
ICA, PERU, 31.61 m., Radio Universal, 811.30 pm.
MADRID, SPAIN, 31.6 m., Addr.
(See 9.860 mc.) 7.30 -8.30 pm.
Mon., Tues., Thur., Sat. at 9.30
pm. also.
9.437
I
9.540
pm.
ANKARA, TURKEY, 31.70 m., 1.205 pm. Irreg.
HCODA GUAYAQU IL,
ECUADOR, 31.77
4.40 -5.10 pm.
9.550
4.15 -6,
1.30 -4,
-11.25
9.445
m.,
12.05
II am., 4.50 -10.50 pm.
VATICAN CITY, 31.41 m., Sun. 55.30 am.
PARIS, FRANCE, 31.41 m. Addr.
(See 15.245 mc.) 2 -5 am., 11.15
am. -6 pm.
SCHENECTADY, N. Y., 31.41 m..
General Electric Co., 7:15 -10 pm.
to So. Amer.
mc. -GSC)
9.580
n
9.20
End of Broadcast Band
&
8
(See
I
Sun.
Addr. Westinghouse Electric
Mfg, Co. 7 am. to
am. Sun.
7,
am. -12
;0.30
6.20 -8.30,
m.,
31.35
DENMARK, 31.51
Addr. Statsradiofonien, Heib-
m.,
I
11.810
5.45 -6.30,
9.520
Addr- Amalgamated Wireless of
TAIHOKU, TAIWAN, 31.13 m.
lays JFAK irreg. 4 -10.30 am.
(See
9.630
Box
COLON IA URUGUAY, 31.12 m..
Addr. Belgrano 1841, Buenos
Aires, Argentina. Relays LR3
Buenos Aires
2.15 am.
9.636
9.590
9.570
FORT DE FRANCE, MARTINIQUE,
30.92 m., Addr. P. O. Box 136.
pm.
CXA8
pm., 6.10.30 pm.
MOSCOW,
U.S.S.R.,
31.25
m.
Daily exc. Sun. 6 -10 pm. Sun. 6 -7,
9.15 -10 pm.
GENEVA, SWITZERLAND, 31.27 m.,
Addr. Radio Nations. Irregular.
DELHI, INDIA, 31.28 m. Addr.
All India Radio, 1.30.3.30 am.,
7.30 am. -12.30 pm., 8.30 -10.30 pm.
HUIZEN, HOLLAND, 31.28 m
Addr. (See 15.220 mc.) Sun. 2 -3,
7 -9.25 pm. Tues.
1.45 -3.40, 7.158.45, 9 -10.30 pm., Wed. 7.15 -8.30
pm., Fri. 8.9 pm.
PERTH, W. AUSTRALIA, 31.28 m.,
Addr. Amalgamated Wireless of
Australasia, Ltd. 6 -9 am. exc. Sun.
SYDNEY, AUSTRALIA, 31.28 m.,
Addr. Amalgamated Wireless of
Australasia, Ltd., 47 York St.,
Sun. -3 am.; 5 -11 am.
PHILADELPHIA, PA., 31.28 m.
(Addr. See 21.52 mc.) Mon. and
Thurs. 7.30 -11.30 pm. Sat. 7.30
10.45 pm.
DAVENTRY, ENGLAND, 31.32 m.,
Addr. B. B. C., Portland Pl.,
London, W. I, 12.20 -1.15. 4.15 -6,
6.20 -8.30, 9.20-11.25 pm.
MELBOURNE, AUSTRALIA, 31.32
m. Addr. Box 1686, G. P. 0.
Daily 3.30 -8.30 am. (Sat. till 9
am.) Sun. 12.01 -7.30 am. Also
daily exc. Sat. 9.25 pm.-2 or 2.15
am. Sat. 5 -10.30 pm.
1
Addr.
9.640
VK6ME
am. Sun. 6.55 arn. -I am.
3/ Met. Aeadcaet .gaied
9.705
9.590
m.
30.82
n. -2 pm..
Addr. Nat. Broad. Sta.
31.23
n. to
1.30
,
9.860
Mc.
PANAMA CITY, PANAMA,
m. Addr. Apartado 867. 12
3
-4.30,
am.,
5
-6,
33.44 m. Addr.
11.30 am.1.30
10 -1I
pm., 12
m. -2 am.
8.841
HCJB
QUITO,
ECUADOR,
33.5
am., 11.45 am. -2.30
pm., except Mon. Sun.
1.30 pm., 5.30 -10 pm.
(Contimrrd on page 732)
7 -8.30
5 -10
m.
pm
n.
12
All Schedules Eastern Standard Time
730
RADIO
&
TELEVISION
Antenna Systems for HAMS
Herman Yellin,
of which the following is the first, describing amateur antennas and containing con-
structional data and tuning hints.
One of the simplest antennas is the half wave Hertz with a single wire untuned
feeder. For greatest efficiency, the antenna
should be used on only one amateur band
and should be cut for a half wavelength.
If operation is desired on only one frequency, the antenna should be cut for that
frequency, whereas if operation is desired
over the entire band, the antenna should
be cut for the center of that band. The
following formula will determine the antenna length
:-
LENGTH
(feet)
-
468,000
frequency (KC.)
All untuned transmission lines or feeders have a defit,ite surge impedance determined by the feeder's mechanical characteristics. If the feeder is terminated at the
antenna in an impedance equal to its surge
impedance, there will be no reflections from
the antenna and no standing waves along
the line to cause radiation from the line.
A single wire line has an impedance of between 500 and 600 ohms. The impedance
of a half -wave Hertz antenna varies from
about 70 ohms at its center to about 2000
ohms at its extremities. At a distance
from the center equal to 1/7 the length of
the antenna, this antenna has a 500 -600 ohm
impedance, and so if the single wire feeder
is coupled to the antenna at this point, no
N.
CENTER
INSULATOR
INSULATOR
W2AJL
A
468.000
O
1. Half -Wave Hertz Single -wire Untuned Feeder
IT IS generally realized that a guod
antenna requires much lower transmitter power than a poor antenna for equal
effectiveness; effectiveness being measured
in signal strength at a distant point. Therefore, a series of articles has been prepared,
_J
FEEDER
A (FEET)- FREQUENCY (KC .)
TO
standing waves will occur. For hest results,
a little experimenting should be done by
varying the position of the feeder tap. The
correct position will be indicated by a
constant value of R.F. current along the line
which may be any length up to several hundred feet. An R.F. ammeter can be placed at
several points along the line, or several
neon bulbs placed along the line, and the
antenna tap adjusted until the current is the
same at all points along the line. When
tapped at the correct point, there will be
minimum or no detuning of the final amplifier tank when the feeder is clipped
thereon, and this is a simple method of
adjustment. On long lines there will be a
slight but steady diminution of current.
The feeder should be at right -angles to
the antenna for a distance equal to about
1/3 the length of the antenna to prevent
interaction between antenna and feeder.
Coupling the feeder to the transmitter
can be simply accomplished by clipping
the feeder onto the final plate coil, starting at the point Of minimum R.F. potential
(ground) and going up the coil until the
tube draws the desired plate current. if
direct current is flowing through the coil
a fixed condenser of .001 mf. or more should
be placed in series with the feeder to keep
n.c. out of the antenna. Otherwise, if the
antenna were accidentally grounded, the
power supply would be shorted. Also unfortunate accidents may result if some unsuspecting neighbor should come in contact
with the antenna.
A more desirable method of coupling,
resulting in elimination of any harmonics.
is shown in Fig. lb. The LC circuit should
tune to the transmitter frequency while
the feeder is adjusted on the coil in the
same manner as before.
When this type of system is operated on
ANTENNA
kl
MP
/-
R.F.C.
- B.TO
FINAL STAGE
ANTENNA
)3
E1 ,. ,, ,.
NC
ID
T
R.FCB+
Z TURN UNK
1 OR
COIL CONNECTED BY
TWISTED HOOKUP
WIRE.
_-
half -wave Hertz Antenna, with single wire
untuned feeder, showing different methods
of coupling.
The
a harmonic, the feeder will have standing
waves along it and will radiate. However,
where it is impossible to erect more than
one antenna and multi -band operation is
desired, the antenna should be cut for the
lowest operating frequency. The feeder
should be tapped on the antenna so that
distance "B" on the diagram is 1/6 the
length of the antenna. Although not a
perfect match on the highest wave band, a
better match is afforded on the lower wave
bands. Better results will be had with this
multi -band antenna if the feeder is a multiple of a quarter wavelength long.
NEXT MONTH-Half- ware doublet with
twisted pair feeders.
Ultra -High Frequency Antennas
BRITISH radio listeners have had far
more experience with the problems of
ultra -high frequency reception than has
the average American experimenter. for
television has become part of the Briton's
daily life. In this article, two engineers of
the British branch of General Electric Co.
discuss their findings.
FIG.2
N (ARMOR )= MEAN
OF SOUND AND
VISION WAVE -
LENGTNS
CONCENTRIC
FEEDER
Television Aerial and Input Circuit
Owing to the relatively high level of
radiated interference in the region of 7
meters it is an advantage in almost all cases
to use a frequency selective aerial feci by a
correctly matched low impedance line to
the receiver input.
The interference is thereby substantially
limited to the frequency range necessary
for reception, and as the aerial is of relatively small dimensions it can be situated
in a position of minimum interference.
The most satisfactory aerial of this type
is the center -fed dipole, shown in Figs. 1
and 2, tuned by adjustment of its length
to the mean sound and vision wavelengths.
The impedance of this varies from a
maximum of several thousand ohms at its
ends to about 80-100 ohms at the center.
Transmission lines of this characteristic
impedance can easily be obtained of compact construction in the form of a concenfor April,
in England to
pick up television and sound signals.
Center -fed dipole aerial used
tric feeder, using a minimum of low -loss
insulating material.
The feeder used for this purpose is shown
in Fig. 1. It has an overall diameter of
about % inch, and is protected externally
from climatic conditions by a layer of insulating material. The characteristic im-
pcdance is approximately 90 ohms, with
attenuation at 45 mc. of approximately
1.0 db. per meter.
In positions of very weak signal strength,
it is therefore possible to obtain improvement by using a higher aerial position, provided the vertical signal strength gradient
is greater than about 1.0 per cent per meter.
At the receiver end, the line is terminated
in a step -up transformer to match it to the
input circuit of the first tube. This transformer also serves the purpose of reducing
the effect of any direct pick -up on the
feeder.
Since the aerial is used to receive both
sound and vision signals, the secondary is
tuned to 44 nie. by the grid- ground capacity
of the R.F. amplifier tube (pentode) and
damped by a terminating resistance to cover
the necessary band -width of both the sound
and vision channels. In the case of the
combined television and broadcast receiver,
the aerial coil is center tapped and connected to the aerial terminal of the broadcast receiver without the use of any
switches. The feeder line is thereby used
directly as an aerial for the broadcast receiver without modification, see Fig. 2.Excerpt front article "Television Receivers,"
by Espley and Edwards, in the Journal of
the Television Society, London.
731
1939
www.americanradiohistory.com
Call
Mc.
Mc.
8.700
HKV
BOGOTA, COLOMBIA, 34.46
Tues. and Fri. 7 -7.20 pm.
8.665
COJK
CAMAGUEY,
CUBA,
m.
and Sun.
W2XGB
HICKSYILLE,
Addr.
N.
8.580
YNPR
MANAGUA,
Y5D
&
7.870
HCIRB
m.,
34.64
NICARAGUA,
SAN SALVADOR,
34.92
Tel.
SALVADOR,
EL
Addr. Dir. Genl. Tel.
m.,
37.99
6.625
PRADO
6.610
YNLG
7 -10.30
pm.
QUITO,
ECUADOR, 38.1 m. La
Quito. 8.30.11.30 pm.
GUAYAQUIL, ECUADOR, 38.2 m.
Evenings to II pm.
GENEVA, SWITZERLAND, 38.48 m.,
6.558
6.550
6.550
1-1140
XBC
TIRCC
Voz de
7.854
HC2JSB
7.797
HBP
7.614
CR6AA
Addr. Radio Nations.
LOBITO,
ANGOLA,
7.510
JVP
7.450
112R3
7.410
HCJIH
7.410
YDA
YV4RB
NAZAKI, JAPAN, 39.95 m., 8 -9.30
em.
SAN JOSE, COSTA RICA. 40.27 m.
" Radioemisora Athena ". 9.30 -11
pm., exc. Sun.
QUITO, ECUADOR, 40.46 m., 79.30 pm. irregularly.
6.516
YNIGG
TANDJONGPRIOK,
6.480
2
JAVA.
40.46
pm.
am.
6.500
HIL
HIIL
HKE
BOGOTA, COL.,
7.200
YNAM
7.177
CR6AA
MANAGUA, NICARAGUA, 41.67
m. Irregular at 9 pm.
LOBITA, ANGOLA, PORT. WEST
6.470
YNLAT
6.465
YV3RD
6.450
HI4V
S. A., 41.55 m.
Tues. er.d Set. 8 -9 pm. Mon. and
Thurs. 6.30-7 pm.
7.100
FO8AA
7.088
PIIJ
7.050
FG8AA
POINT
-
A
GUADELOUPE,
6 -7 pm., also
PITRE
-
F.W.I., 42.55
m
Irregular. P.O.
Box
YUCATAN, 42.89
No. 517,
59,
"La
9.10.30 pm.
125.
6.990
XEME
MERIDA,
Addr. Calle
XBA
6.805
HI7P
6.790
PIH
Irregular.
TACUBAYA,
MEX., 43
9.30 am..1 pm., 7 -8.30 pm.
D.
F.,
6.400
TGQA
6.775
6.750
6.730
6.720
6.690
HIH
JVT
HI3C
PMH
TIEP
6.335
OAXIA
6.324
COCW
or 11.30 am. Also Sat. 9.30 pm.1.30 em.
SAN JOSE, COSTA RICA, 44.82 m.,
Addr. Apartado 257, Le Voz del
Tropico. Daily 7.11 pm.
GENEVA, SWITZERLAND, 44.94 m.
Addr. Radio- Nations- Off the air
at present.
6.675
HBQ
6.672
-
6.672
YVQ
MARACAY, VENEZUELA, 44.95 m.
6.635
1-1C2RL
GUAYAQUIL, ECUADOR, S. A.,
45.18 m., Addr. P. 0. Box 759.
Sun. 5.45 -7.45 pm., Tues. 9.15-
--
44:94 m., relays
Salamanca, Spain, 7 -9.45 pm.
11.15
pm.
6.150
CJRO
WINNIPEG,
48.78 m.,
W8XK
6.137
CR7AA
LAURENCO MARQUES, PORT. E.
AFRICA, 48.87 m. Daily 12.05 -1
4.30 -6.30, 9.30 -11 am., 12.05 -4 pm.
Sun. 5 -7 am., 10 am. -2 pm.
6.133
XEXA
MEXICO
1
-3
del Radio Philco,
P.
O.
6.130
GEORGETOWN,
VP3BG
HIZ
CIUDAD TRUJILLO,
Daily except Sat. and Sun. 11.10
am. -2.25 pm., 5.10 -8.40 pm. Sat.
5.10 -11.10 pm. Sun. 11.40 am. -I.40
pm.
MARACAY, VENEZUELA, 47.62 m.
6.30 -9.30 pm. exc. Sun.
LIMA, PERU, 47.63 m., Addr.
Apartado 1242. Daily 7 -10.30 pm.
6.270
YVSRP
6,255
YVSRJ
6.243
HIN
6.235
HRD
D. R., 47.52 m.
TRUJILLO CITY, D. R., 47.77 m.
7.10-9.40 am., 11.40 am.-2.10 pm.,
3.40 -9.40 pm.
CARACAS, VENEZUELA, 47.79 m.,
Addr. "La Voz de la Philco.'
Daily to 10.30 pm.
CARACAS, VENEZUELA, 47.18 m.
5.30 -8 pm.
CIUDAD TRUJILLO, D. R., 48 m.,
Addr. "La Voz del Partido Dominicano." 12 n. -2 pm., 6 -10 pm.
LA CEIBA, HONDURAS, 48.12 m.,
Addr. "La Voz de Atlantide.''
8 -11 pm.; Sat. 8 pm:
am.; Sun.
4 -6 pm.
VA6
VENEZUELA, 48.15 m.
-9.3LERA,
0 pm.
SAIGON INDO -CHINA, 48.28 in.,
I
6.225
6.210
6.205
6.200
-
YVIRG
YV5RI
14180
Addr.
Boy Landry, 17 Place
A. Foray. 4.30 or 5.30 -9.15 am.
CORO,
Radio
VENEZUELA,
48.32
6.130
TIEM
"El Mundo'', Apartado 1049. II
am.-II pm., Sun. 10 am. -6 pm.
HALIFAX, N. S., CAN., 48.94 m.,
Addr. P. O. Box 998. Mon.-Fri.
7 am.-11.15
pm., Sat. II am:
II pm., Sun. 12 n.-11.15 pm. Relays CHNS.
CHNX
6.130
LKL
6.126
CXA4
6.122
HJ3ABX
6.122
HPSH
6.122
FK8AA
6.185
TG2
I
HUA
P.
O.
Relays
Sat. 6
6.117
XEUZ
6.115
OLR2C
I
5 -II pm,
NOUMEA,
NEW
CALEDONIA,
m., Radio Noumea, Addr.
Charles Gaveau, 44 Rue de l'AI.
ma., Wed. & Sets. 2.30 -3.30 am.
MEXICO CITY, MEX., 49.03 m.,
Add,. 5 de Mayo 21. Relays
XEFO 9 am.
pm., 7 pm. -2 um.
I
6.110
P
GSL
RAG U E,
CZECHOSLOVAKIA,
(See 11.40
DAVENTRY,
ou.)
ENGLAND,
49.1
m.,
6.20 -8.30, 9.20 -11.20 pm.
MEX., 49.1 m
Addr. La Voz de Aquila Azteca
desde Mex., Apartado 8403. Relays XEJW II pm. -I am.
MANIZALES, COL.,
COL. 49.14 m., Addr.
P. O. Box 175.
12.15pm. Tue. and Fri. 7.30 -10 pm.;
MEXICO
6.110
XEGW
6.108
HJ6ABB
CITY,
I
Sun. 2.30 -5
6.100
YUA
BELGRADE,
m. -3,
pm.
1
6.100
WIXAL
6.097
ZRK
6.097
ZRJ
6.095
JZH
Sun.
D. R., 48.5 m., Addr.
Box 423. 7 am. -5 pm,
PANAMA CITY, PAN., 49 m.,
Addr. Box 1045. 10 am. -I pm.,
49.05 m.
Mon. -Fri,
TGI
pm: em.
3.8 pm.
I
49.00
Irregular.
GUATEMALA CITY, GUAT., 48.4.
m., Addr. Dir. Genl. of Elect,.
Commun.
6.11 pm.,
7 -II am.,
SANTIAGO,
JELOY, NORWAY, 48.94 m.
am.6 pm.
MONTEVIDEO, URUGUAY, 48.98
m., Addr. Radio Electrico de
Montevideo, Mercedes 823. 8
am. Noon. 2 -10 pm.
BOGOTA, COL., 49. m., Addr. La
Voz de Col., Apartado 26 -65. 12
n:2 pm., 5.30-11 pm.; Sun. 6 -11
Om.
m,
6.190
GUIANA.
SAN JOSE, COSTA RICA. 48.94 m.
6.130
m.,
Addr. Roger Leyba, care A.
Urbina y Cie. Irregular.
CIUDAD TRUJILLO, D. R., 48.36
BRIT.
48.94 m. 9 -10 em., 2.15 -6.30 pm.,
Sun. 5.30 -11.30 am., 3 -5 pm.
am. -10 pm.
6.310
m.,
em., 2.30 -4 pm., 7.30 pm:
12.45 am. Sun. 1.30 pm. -12.45 am.
8 -11
pm.
ICA, PERU, 47.33 m., Addr. La Voz
de Chiclayo, Casilla No. 9. 8II pm.
HAVANA, CUBA, 47.4 m., Addr.
CITY, MEX., 48.93
Addr. Dept of Education. Daily
am. -I.40
QUEZALTENANGO, GUATEMALA,
46.88 m., Mon. -Fri. 9 -11 pm. Sat.
am. Sun.
CANADA
(See 11.720 mc. )
6.140
GRANADA, NICARAGUA, 46.36
m., Addr. Leonidas Tenoria, "La
Voz del Mombacho." Irregular.
BARQUISIMETO, VENEZUELA,
46.37 m. Radio Barquisimeto, irregular.
SAN FRANCISCO DE MACORIS,
-1
MAN.,
Addr.
Daily 6 pm. -12 m., Sun. 5 -10 pm
VILLARRICA, PARAGUAY, 48.788
4 -6 pm.
BULAWAYO,
RHODESIA, 5
AFRICA, 48.8 m. Mon., Wed.
and Fri. 1.15.3.15 pm.; Tues. IIÌ
n.; Thurs. 10 am. -12 n
Sun. 3.30.5 em.
MEDELLIN, COL., 48.79 m. II am.
12 n., 6 -10.30 pm.
PITTSBURGH, PA. 48.83 m., Addr.
Westinghouse Electric & Mfg
Co. Relays KDKA II pm. -I2 m
D. R., 46.13 m.
623. 12.10 -1.40
pm., 5.40 -7.40 pm.
SANTIAGO DE LOS CABALLEROS,
pm.
am.
7
Box 130. 6.55 am, -12 m. Sun. 9.55
Daily
BANDOENG, JAVA, 44.64 m. Relays N.I.R.O.M. programs. 4.30-11
CIUDAD TRUJILLO,
Addr, Apartado
La Voz
HIG
KokusaiDenwa
Ltd.,
Tokyo. Irregular.
LA ROMANA, DOM. REP., 44.58
m., Addr. "La Voz de la Feria."
12.30-2 pm., 5 -6 pm.
VP/3
pm.
6.280
Addr.
HI5N
6.150
HJ4ABG
CIUDAD TRUJILLO, D. R., 47.32 rr..
Sun. 7.40 -10.40 am., daily 12.101.10 pm., Tues. and Fri. 8.10.10.10
OAX4G
m.,
Kaisha,
6.153
6.145
46.02
las
HIIX
6.295
44.44
YV5RD
CARACAS, VENEZUELA, 48.71 m
II am. -2 pm., 4 -10.40 pm.
MOCA CITY, D. R 48.75 m. 6.40
9.10 pm.
C01.10OMBO,
CEYLON, 48.78 m.,
6.156
pm. Except
6.340
and Sun. 12.40 -1.40. 6.40 -8.40 pm.
Set. 12.40 -1.40 pm. Sun. 10.40 am.11.40 am.
NAZAKI, JAPAN,
49 Ad. Litoadcaet iland
ZPl4
BASSETERRE, ST. KITTS, W. INDIES, 46.99 m. 4.4.45 pm. Wed.
7 -7.30
am.
YV4RD
SAN PEDRO DE MACORIS, DOM.
REP., 44.26 m. 12.10 -1.40 pm.,
7:30 -9 pm. Sun. 3 -4 am., 4.15 -6
pun., 4.40 -7.40 pm.
I
ZBB
-10
8
NEW YORK CITY, 48.62 m., Addr.
Col. B'cast System, 485 Madison
Ave. Mon., Fri. 12 m.-1 am. Sat.
& Sun. 11.30 pm.,
em.
6.147
ZIZ
6.300
6.06 -8.36 am., Sun. 9.36 -11.36 am.
Daily 5.36 -8.36 pm.
1.2.20,
Call
W2XE
6.150
6.384
m.
44.16
D. R., 45.74 m.
MANAGUA, NICARAGUA,
m.,
Addr. "La Voz de
10
CIUDAD TRUJILLO, DOM. REP.,
44.06 m., Addr. Emisoria Diaria
de Commercio. Daily exc. Sat.
PARAMIRABO, SURINAM.
Addr. P. O. Box 18.
1.30-
Except Sun. 11.55 em.I.40 pm.
VERA CRUZ, MEX., 45.8 m. 8.15.9
am.
SAN JOSE, COSTA RICA, 45.8 m.,
Addr. Radioemisora
Catolica
Costarricense. Sun. 11 am. -2 pm.,
6 -7, 8 -9 pm. Daily 12 n. -2 pm.,
6 -7 pm., Thurs. 6 -11 pm.
BOLIVAR, VENEZUELA, 45.84 m.,
Addr. "Ecos de Orinoco." 6 -10.30
Pm.
VALENCIA, VENEZUELA, 45.98 m.
11
am. -2 pm., 5 -10 pm.
R., 46.48 m,
11.40
pm., 5.10 -9.40 pm.
m.,
desde Merida."
Voz de Yucatan
6.977
CIUDAD TRUJILLO,
45.39
Dario.
D.
AFRICA. 41.75 m., Mon., Wed.,
Sats. 2.45 -4.30 pm. Also see
7.614 mc.
PAPEETE, TAHITI, 42.25 m., Addr.
Radio Club Oceanien. Tues. and
Fri. II pm.-12.30 em.
DORDRECHT HOLLAND, 42.3 m.,
Addr. Dr. M. Hellingman, Technical College. Sat. 11.10 -11.50 am.
NICARAGUA.
D. R., 46.28 m., Addr. Box 356.
9.40 -11.40 am., 7.40 -9.40 pm.
MEXICO CITY, MEX., 40.65 m.,
Addr. Foreign Office. Sun. 7 -8
7.220
MANAGUA,
Mc.
6.170
Sundays.
am.; Sat. 7.30 pm.-
-2
TRUJILLO, D. R., 45.25
m., Addr. ''La Voz de la RCA
Victor," Apartado 1105. Daily
exc. Sun. 12.10 -1.40 pm., 5.40.8.40
pm.; also Sat. 10.40 pm..12.40 am.
RIOBAMBA, ECUADOR, 45.28 m.
Thurs. 9 -11.45 pm.
Lagos."
Addr. N.I.R.O.M., Batavia,
10.30
XECR
YV6RB
6.520
m.,
7.380
6.545
39.39
Mon., Wed., Sats. 2.45 -4.30 pr-.
Also 7.177.
CIUDAD
m. Emisora Ruben
2.30, 6 -10.15 pm.
9
Radiodifusora Pilot.
m.
7.894
Y.,
Wireless, Mon. to
am. and 5 pm.
Press
Fri. News at
HIT
m
34.64
Addr. Finley No. 3 Altos. 5.306.30, 8.11 pm., daily except Sat.
8.665
Call
6.630
pm.
JUGOSLAVIA,
6.30 -8.30
49.18
am., Noon -6.30
BOUND BROOK, N. J., 49.18 m.,
Addr. Natl. Broad. Co.
KLIPHEUVEL, 5. AFRICA, 49.2
Addr. S. African Broad. Co.,
Johannesburg. Daily 12 n. -4 pm.,
Sun. 12 n. -3.20 pm.
JOHANNESBURG, S. AFRICA, 49.2
m. Addr. S. African Broad. Co.
Daily exc. Sat. 11.45 pm. -12.50
em.; Daily exc. Sun. 3.15 -7.30,
9.11.30 em. (Sat. 8.30 -11.30 am.)
Sun. 3.30 -4.30 or 4 -5 am., 5.30 -7,
9.11.30 am.
TOKYO, JAPAN, 49.22 m., Addr.
(See 11.800 mc., JZJ.) Irregular.
(Continued on pane 758)
All Schedules Eastern Standard Time
732
RADIO
&
TELEVISION
First Prize EUinner
Pilot Lights Replace
Meters
Visitors to Ham shacks often
fool around with the variable
transmitter settings. Then, when
the transmitter is put into operation, the buffer or amplifier stage
draws excessive current which
damages the tube unless battery
Radio Kinks
will award a 2 year subscription for the best kink
submitted. All other kinks published will he awarded eight months'
subscriptions to RADIO & TELEVISION. Look over these kinks: they will
give you some idea of what is wanted. Send a typewritten or ink description
with sketch of your favorite to the Kink Editor.
Each month the Editor
down to
ti \)
xT AL
RI/
on a
._ 60 HA.
BULB
A
B*
circuit while the rig
is in operation. Purchasing pilot
be used in
in the crystal circuit of the oscillator with a 60 ma. bulb in its
socket. This enables me to watch
the crystal current at all times
for overheating. I wired another
in series with the 11 positive lead
to the final stage and put a Xmas
tree bulb in the socket. When
the amplifier is tuned, the bulb
barely glows, but if excitation
fails or the tank is detuned. etc.,
the bulb glows brightly and attracts the eye immediately.
Recently, I put a bulb into
each stage, which makes tuning
of individual stages easier and
more precise. A Xmas tree bulb
is the correct size for such tubes
as 10's, 801's and their equivalents.- Operator, if '8Q K:1.
Fancy Glass Panel
A neat and attractive panel
may be made by taking a sheet
of double -strength window glass
the required size and drilling the
MOLE
DRILLED
LETTERS
CUT OUT
PANEL
ENAMELED
ENAMELED
WHITE OR SILVER
BLACK
a
three -cornered point
grinding wheel. After drill-
ing the holes, clean the glass
thoroughly and apply a coat of
black enamel to the back of the
panel. Allow this to dry, then
scrape the paint off the back
of the panel with a razor blade
where the lettering (such as
AVC, ON, OFF, etc.) is to
appear. Paint over the back in
white or silver where the lettering was cut out. The finished
job has a mirror -like appearance and will improve the looks
of your receiver or transmitter.
Payne Hawley.
-I
light mountings fitted with colored jewel windows, I numnted
these on the panel. I inserted one
DOUBLET
l
140 MMF.
ANTENNA
J
(
1
140
30
LINK
SAME AS
GRID COIL
IN RECEIVER
GRID COIL
Doublet Coupling
Here is a method of increasing the sensitivity of a small
radio receiver.
Procure a coil form the same
size as that used in the first
stage of the set and wind a coil
on it of the same size wire and
number of turns as the grid
coil of the set. Remove the antenna trimmer condenser, connect the coil, as shown in the
accompanying diagram. Coupling to the grid coil of the set
is made with two single turn
coils of ordinary hook -up wire.
The condenser used to tune the
coil you have wound should he
of the same value as the main
tuning condenser in the set. In
the diagram the dotted line
represents the original antenna
connection, which has been reI find a doublet works better
than an inverted L to pull in
BLACK
necessary holes in it. If a mixture of camphor and turpentine
is used, the glass will drill easily.
Drills may be made from old
tiles
ground
three-cornered
for April,
weak
signals. Frank
'HOT" LEAD SOLDERED
TO
SLOT FOR SCREW-
DRIVER
BAKELITE
STRIP
Smith,
.]r.
8-32
SCREWS
SPRING
SHIELD
SOLDERED.
"NOT" LEAD
SOLDERED TO
EYELET
SHIELD SOLDERED
for microphone or phonograph
pick -up, can be easily and quickly made with male and female
parts of an auto antenna connector. The wires are soldered to
the insulated plugs. The shield is
soldered to the case of the units.
-Raymond T. Stephens.
Electric Heater For
Soldering Iron
An electric heater, that brings
any cheap soldering iron to operating temperature and maintains
it at working heat, can he made
front parts bought at the 10 -cent
store. The base of this iron
heater is a piece of wood about
5 "x7 "x3 ". To this I screwed a
SHEET METAL
3
-x 6^x I/6 THICK
PORCELAIN
SOCKET
HEATER
ELEMENT
SOLDERING
IRON
STIes
WIRE
BASE BOARD
7 ^x
5'x3/4 -
Connections between long sections of one -wire shielded cable,
ANGLE IRON
easily constructed from workshop scrap. The essentials are:
two 8/32 screws, two small
angle irons and a strip of hakelite. One hole in each of the
angle irons is threaded to take
the screws. The irons are then
mounted on a Bakelite strip, as
shown in the diagram, and are
thus insulated from cads other.
The screws are then mounted
as shown and a slot cut into the
end of the upper one, so that
it may be adjusted by a screwdriver. Lock nuts may be used
on the screws to prevent their
shifting, if desired. If the unit is
to be baseboard mounted, a third
angle iron can be used at one
end of the bakelite strip, as
shown.-Charles :Allen.
Tank Coil Terminals
In low -powered transmitters,
tank coils are usually wound on
standard coil forms. The following kink has been used to provide a way to connect antenna
feeders neatly to the coupling
coil. Two grid caps from a pair
of defunct tubes were obtained
and drilled out to pass small
bolts. They were then bolted
to opposite sides of a standard
coil form. The ends of the
coupling coil were connected to
the grid caps on the inside of
THICK
SMALL SCREW
AND NUT
piece of 1 /16" metal, the dimensions of which are shown its the
sketch. On this metal I mounted
a porcelain socket to hold an
electric heating element in a
horizontal position, and opposite
the opening of the heating element I mounted a piece of stiff
wire to serve as a rest for the
handle of the iron. The head of
the iron is inserted into the heating element and the current
switched on to bring the iron to
STANDARD
COIL
FORM
GRID
CAP
OLD GRID CAP BOLTED
SIDE OF COIL FORM
(ONE. ON OPPOSITE SIDE ALSO)
TO
of the sheet metal must be
mounted so that it comes between the beater and the wooden
base in order to prevent scorch-
the coil. All that is necessary
when changing coils is to pull
the feeders, which are terminated
in insulated grip cap connectors,
yank the coils and substitute the
new ones.
Richard L. Kite,
ing.-Carvil Mason.
K6QPG.
working temperature. The foot
Shielded Cable
Connector
LEAD
ANGLE
EYELET
IRON
MIAF.
moved.
ENAMEL
A simple neutralizing condenser, convenient for neutralizing a 61.6 beam power tube. is
LEAD
bias is used. My rig at W8QKA
has cheap meters which cannot
2A5.61.6.42
Improvised Neutralizing Condenser
-
733
1939
www.americanradiohistory.com
-21"" A 6-Tube,
1.4 Volt
for
the "#a11111
battery- operated 6 -tube super has surprising
sensitivity and selectivity. The circuit employs a
regenerative mixer, an oscillator, I.F. amplifier, regenerative detector, B.F. oscillator and A.F. output
tube. Operation is very economical, the total filament drain being only .3 ampere.
This
superhef,
6 -tube
economical
This
receiver to be described here,
Tillas sensitivity and
selectivity are concerned,
the equal of many standard
Lc.
c,.nuuunications" type
receivers using the same
i'.
which will appeal to Hams and Fans
alike, will operate a loud speaker.
THE fine results obtained with the
number of tubes.
The circuit, as is shown below, consists
of a 1A7 -G regenerative mixer, a 1\15 -G
oscillator, a 1 \5 -G 460 kc. I.F. amplifier,
a 1.1%15-G regenerative detector, a 15 -G
beat -frequency oscillator and a 1. \5 -G
1.4
volt "Economy Three" T.R.F. receiver
described in the February issue induced
the writer tu try out the new tubes in a
superheterodyne circuit. The results far
exceeded his expectations and the six-tube
2
I
'
DOUBLET
IATG
TENNA
35
ANT.
'
L5E[
s
v
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2
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OS
-
LN5G 05C.
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OHMS
Ni.
H
2
ANT
CI9
35
MMF,
35
NtniF
(OPTIONAL)
G.
GANGED
'"
NSG -,
IR. AMP.
50 OR 60
TURNS
N=34
I
MEG.
1
01'
r
at~,
200
'6'
(ADJUSTABLE)
ANTENNA
COIL
r"""",..FIG.S^
I
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1N5G
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.
J
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30H.
I
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0.5-
CH.
COIL
SW.
I
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MEG.
C'h V+(1.5V.)
1
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MMF
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RFC
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100
35
MMF
(OPT IONAL)
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460KC BO.
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TICKLER
I
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,
I
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025-
0.1 _MF.
COIL
FORM
\
OS/ME
1
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ASSEMBLY
/
R.F.C.
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100
MMF.
given below.
are
2.5MH.
3
KC
BEAT OSC
I FT.
OHMS
(CAP)/
/
50.000
DHMS
(EACH)_
-460
STAND-OFF INSULATORS
G
O -LTSEETExTe
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V
I.FT
MbF
GND.
C1!'z
B-.A-,C+-+
50
.MMF
2000
T
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B+
90v.
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s;
OHMS
/
TÑ15TE0
1A-I0 MIXER
ANTA-1.741A
2
TEXT)
qqOUND FORM.
.006MF
l00
50
MEG.
20R3TURNS Ne12
WIRE,2 DIAMETER
-ww
MMF
MMF.
I
MIXER COIL
-rpFC
2.5
-
MF
50.000
c
I
I
I
ti
C
200
3
1
-_
j
1N5G
B.O.
/
(/
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(ADJUSTABLE)
L5p
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L6
0.25-
G GANGED
1
SMH.
i
250
N1MF
LT
R.FC.f
3
..-.-
NIP
for the superhef
ZOO MMF
LNSG
ADJUSTABLE DETECTOR
KC
O.l-
(EACH)
-
TICKLER
I
Wiring diagrams, both schematic and pictorial,
(CAD)
L
qqr
6
w%v`I
LTA
KC. (CAP)
OHMS
a
COIL
460
T0.000
(CAP)
.
i.
LF.AN;PLIFIER
3
1^¡
REGEN.
1N5G
natER
LI
%IMF
1
audio output amplifier. The tubes used are
all of the new economical 1.4 volt type, the
total filament drain being only 0.30 ampere and the measured "B" drain less than
0.02 ampere at 90 volts. The R.S. gain
(sensitivity) in the 1. \7 -G circuit is tremendously increased by making the mixer
regenerative. The method of introducing
feed -back is novel but extremely simple
\../
/
I..'
1
MF
f`
I
F
1
50
I
MF
I
I
MMF
I
0.25
'1
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2.5
MH.
II
i
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R.FC_
'0
II
'o
MEG.
B-
B+
+
C1/2V.
90V.
,
,
0.1 MF
734
'
/.001MF
0.25'
y
---1016'
SEE
TEXT
s
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www.americanradiohistory.com
2
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E.
.p SW.
'
A+
(15v)
TELEVISION
view of the superhe+
showing the National
precision band- spread dial.
Front
SUPER -HET
oz
S-W
chassis,
7czn
Harry D. Hooton,
W8KPX
-a
small home -made R.F.
and effective
choke (L7) consisting of about 25 to 30
turns of No. 26 enameled wire is wound on
an old broadcast R.F. choke spool (one -half
inch diameter) and inserted in the positive
leg of the 1A7 -G filament return, close to
the tube socket, as shown in the diagram.
The other (negative) filament lead is returned to ground through the tickler winding, L4. A 2,000 ohm potentiometer shunted
across IA permits the feed -back to be
varied over a considerable range. The oscillator is of the conventional type, the R.F.
output being taken from the plate of the
tube through a small adjustable coupling
condenser. Although better screening between the oscillator coupling grid, GI, and
the mixer elements could be obtained by
returning the anode grid, G2, to ground, it
has been connected to the positive 90 volt
plate return, in order to take advantage of
the higher conversion gain thus made
possible.
The I.F. transformers are of the iron -core,
air -trimmed type which gives the maxi
mum gain in this circuit. The tickler winding in the detector circuit. L7A, consists
of about 50 or 60 turns of No. 34 g.s.c.
wire jumble wound on the I.F. transformer
core, about one -fourth inch front the grid
coil, as shown in the drawing. The direction of the winding is not important as the
leads can be reversed until oscillation is
obtained. It should be emphasized at this
point that the detector is not permitted to
oscillate; the feed-hack condenser, in series
with the tickler coil, is adjusted so that the
1N5 -G is operating just below the point
of oscillation at all times. A separate beat
oscillator is used
for the reception
of c.w. code signals when this is
desired.
This
method of operation greatly facil- j
itates the reception of the weaker signals, which
would be lost in the noise if the detector
circuit was allowed to oscillate. However,
if a great increase in I.F. selectivity is desired, or if the set is to be used for c.w.
code reception only, the detector can be
permitted to oscillate and the output I.F.
transformer adjusted to cut off one sideband, giving the effect of "single signal"
reception. Alignment details will be found
farther on in this article.
The mechanical construction of the receiver is not at all complicated or difficult.
As the photos and drawings show, the
various parts are mounted in the National
"C- One -Ten" steel cabinet, no separate
chassis being used. The dial and tuning
condenser assembly is the National "l'\V -2"
type, which spreads the tuning scale over
500 degrees on the dial. The photograph
of the sub -base assembly, taken before the
receiver was wired, shows how the tuning condensers, the I.F. transformers, the
coils and the tubes are placed. For exact
dimensions, refer to Fig. 3.
In wiring the circuit, keep the "hot" grid
and plate leads as short and direct as
possible. Place these leads right against
the metal sub -base in order to limit their
external fields; it may be necessary to
shield the plate
and grid leads
from the I.F.
transformers
and the 1A7 -G
and INS -G
mixer and I.F.
tubes to eliminate oscillation
at the I.r. level.
Place the bypass
condensers right
on the socket
terminals themselves in order
to obtain
Rear top view of the 6 -tube
receiver.
a
short, low -impedance path to
ground for the
R.F. and LF. currents. lise solid
No. 14 tinned
copper bus wire
for making the
(Continued on
page 754)
Ports List, 1.4 Volt Super
NATIONAL CO.
-P V -2 tuning unit (50 mmf.
double -spaced)
2- Iron -core S.F. transformers,
with
1
-"C -One -Ten" cabinet,
sub -base
-R -201 R.F. choke, 12 mh.
-R-100 x.r. choke, 2.5 mh.
I -Set XR -5 coil forms (see
2 -5 -prong isolantite sockets
per section,
450 -550 ke.
panel
1
and
1
1
text)
4-8-prong isolantite
2
3
-UM
-No.
sockets
-35 tuning condensers (35 mmf.)
8
grid clips
1- Beat -frequency oscillator transformer,
450 -550 kc.
-M -30 padding condenser (30 mmf. max.
1
capacity)
HAMMARLUND
2
_
-Adjustable padding condensers,
220 mmf.
max. capacity
-- Aluminum tube shields
SPRAGUE
6 -Paper dielectric tubular condensers,
Inf.. 600 volts
0.1
-Mica
condensers, 0.006 mf.
- -Mica condensers, 0.0001 mf.
2condensers, 0.001 mf.
I -Mica condenser. 0.00025 mf.
1 -Mica condenser, 0.01 mf.
2
I.R.C. (Resistors)
I -Fixed resistor.
3 -Fixed resistors,
2-Fixed resistors,
I -Fixed resistor,
200.000 ohms. ?, watt
50.000 ohms. 1 watt
250.000 ohms, I watt
70,000 ohms, 1 watt
(Volume controls)
1-Volume control, 2.000 ohms. with DPST
switch (regeneration)
1-Volume
volume)
control,
500.000
ohms
(audio
BRUSH
I
-)'air crystal headplomes, or bnulspcaker
RAYTHEON (Tubes)
1
4
1
-1A7 -G
-1 N -G
-IA5 -G
5
tube
tubes
tube
CROWE
4- Pointer
knobs
WRIGHT DECOSTER
I-Permanent
magnet dynamic
universal transformer
speaker with
EVEREADY (Batteries)
-No. 386 "B" batteries
,,; volt "C" lottery
I -11', volt dry cell or 15. volt
2
1-
"A"
pack
MISCELLANEOUS
Hook -up wire, solder, machine screws, etc.
735
for Apr;', 1f39
www.americanradiohistory.com
#ow to Build
An All -Wave
8 -Tube
Front View of All -Wave
8 -tube
of
This unusual 5 -band super -het, with range
Super-het receiver.
to Z306 meters, employing 8 tubes for
loud- speaker reception, can be built with 5
tubes for head -phone use. It has band- change
switch, beat oscillator, noise- limiter and built in power -supply.
7
MANY Hams and S\CL's would like a receiver covering not
only the complete short -wave spectrum, but the broadcast band
and the long waves as well. A receiver covering such a wide
range presents rather impressive difficulties in the coil arrangement. Naturally one must have coil switching, but this presents
quite a problem in designing the necessary coils and still greater
difficulty in getting the coils for each band to "track" properly.
Fortunately the problem has been solved by the availability of an
efficient multi -wave coil assembly 'designed by the Meissner company. This coil assembly covers the frequency spectrum between
132 kc. and 42.E megacycles in five bands. Designed to he used
Hook -up of
5 -band 8 -tube
receiver: it can be built with
tubes for head -phones, eliminating power A.F. stage, "magic- eye ", and "B" supply.
5
MEISSN
COIL
EP
ASSEMBLY
G
I
R.F.
C14
0.14 MF.
SECTtONti
D
6H6 2ND.- DETECTOR.A.VC.
AUTO NOISE LIMITER
1853
^.ANTENNA
tt"
WHITE b
BROWN
with a 3 -gang, 410 mmf. tuning condenser, the coil assembly comes
already aligned at the factory so that only slight readjustment is
necessary for efficient operation.
The set built around this coil unit by the writer contains a
50.000
R12
OHMS
4 MF
'
BLACK`
=
`-R6
50
OHMS
6
C23
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OHMS
OHMS
CMH6u5--I
'TU NIN
DICA
6H6 2ND.- DET-A.V.0 -AUTO
1.--R 27
8R
1
NOISE LIMITER
1ST
SEE TE
AFL
' 777
MEG.
PHONE
BEAT OSC.
657
I. F.
14
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A
IOOMA
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A%
OHMS
-
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NOTE
75.000
PHONE JACK
-.L._._.__
RECT.
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75000
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923
ANTENNA
rJACS
1
SECTION
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TRANS.
R12
GVG
A.F.
R13
AMP
Cl
DETECTOR
SECTION
R24
R27
R28
LINE
C12
OSCILLATOR
SECTION
9
TUNING
INDICATOR
SW.
'4L-WP
;q
110
AC
736
C28
C27
10N. IOOMA
CHOKES
RADIO
www.americanradiohistory.com
&
TELEVISION
Herman Yellin
W2AJL
Ultra -Mo derì'
Receiver
A
Top view of 8 -tube super -het.
,
total of eight tubes. hut the constructor can
easily omit the power audio stage, the rectifier and power supply, and the "magic -eye"
tuning indicator. Thus if the builder already
has a power supply and amplifier, only five
tubes need be used.
The complete receiver was assembled on
a chassis factory -punched with the necessary holes, so that only a few small holes
had to be drilled. Construction is thereby
greatly facilitated. Incidentally, the large
slide -rule type dial should be supported at
its ends by a pair of simple brackets which
can be obtained with the dial.
For the R.P. stage, the new variable -mu
high frequency pentode, the 1853, was em
ployed. Even on the lower frequencies, the
increased gain over the standard 6K7 was
noted. On the high frequencies, of course,
the increase was more marked. Unfor
tunately, when using such a large value of
tuning condenser, the use of an R.F. stage
results in an actual loss instead of a gain
on the very highest frequency band, so that
on this band the R.P. stage is omitted. The
sensitivity on this hand is still adequa e.
however. It will be noted that only a por
tion of the 1853 cathode resistor is bypassed. This is done in order to minimize
changes in input capacitance and input conductance with changes in plate current. Also
note that the suppressor is connected directly to ground and not to the cathode.
Combination 1st Dist. & H.F. Oscillator
A 61<8 tube is used as a combination first
detector and high - frequency oscillator. This
tube is equivalent to a 6L7 -6C5 combination
and has a much higher conversion efficiency
than the old converter tubes. St the single
I.F. stage is a 6S7 which is somewhat like
a 6K7 except for its higher amplification
and lower screen voltage. Its filament current is only 0.15 ampere. Following the 6S7
is a 6H6 which performs a multitude of
functions. First, it operates as the second
detector; second, it provides Ave.: and third,
(Continued on page 743)
for April, 1939
Tuning
*
*
*
s
Full range selectivity in the
crystal filter makes the "HQ120" ideal for either phone or
C.W. operation.
Over 310 degrees spread for
each amateur band. Direct calibration in megacycles allows
the amateur to check frequency
with marked accuracy.
Due to uniform R.F. gain and
constant crystal filter output,
the calibrated "S" meter provides an accurate check on sie'nal strength.
=
=
c
*
*
*
range- 31- -.54
-
mc.
Special
15 -gang
condenser,
main tuning, and 9 -gang
band spread, provides uniform
band spread and high efficiency
on all bands.
Efficient noise limiter for redue
ing automobile ignition QRM
and similar disturbances.
6 -gang
Antenna compensator permits
perfect circuit alignment with
all types of antennas. Also pro
vides maximum image rejection.
Write Dept. RT4 for Booklet
=
= _
Canadian Office: 41 W. Av. No., Hamilton
FEATURES
MARTIN FLASH
SIMPLICITY
PERFECT
CONTROL
SEMI-AUTO.
MATIC
The greatest VALUE
ever offered
EASE OF
OPERATION
STURDY CONSTRUCTION
Single lever. Two pairs of coin silver
contact points . . . one for dots, the
other for dashes.
Designed especially to meet the demands of
amateur operators. Beautiful black
crackle finish. This key is a "winner." Weight. 2 pounds. Base. 6x3x3, S6.
New low list, each
Discount to Amateurs 404/e
Ask your dealer to show you the FLASH
supply you. send your order direct to us.
Key.
If
he
cannot
Write for complete catalog illustrating and describing all models.
MARTIN RESEARCH & MFG. CORP.
98
Please say you saw it
in
RADIO
&
PARK PLACE
TELEVISION
www.americanradiohistory.com
Dept. RT -4
NEW YORK CITY
737
-
a
U n ¡vers al
Test Meter
This fest meter can be built at nominal cost.
It has A.C. and D.C. ranges of O-10, 50, 250,
¡000 and 2500 volts. Current ranges are I,
IO, 50, 250 ma. Three resistance ranges are
incorporated. Special scale fo fit standard
meter accompanies this article.
Owing to the fact
Ihat a switch quickly
converts the meter for
the different ranges,
tests of many kinds
may be made rapidly
instrument.
this
with
rectifier for reading voltages. If a meter
with a lower maximum current reading
were used, it would be necessary to shunt
the meter for A.C. and use separate sets of
multipliers for direct and alternating
current.
inaccurate after being in use for some time.
Unless checked with a reliably accurate
instrument, the owner will remain bliss.
fully unaware of any errors in his cheap
test meter.
\VHILE the necessity for a universal
type of test meter is agreed upon by
all experimenters, the form which it is to
take is a matter of wide disagreement.
Practically everyone will agree as to the
desirability of having as great a meter sensitivity as practicable. However, the greater
the meter sensitivity, the larger the size of
the multipliers for a given range and so
the higher the cost.
There is one school of technicians that
leans toward the use of carbon or metallized
resistors as multipliers, thereby greatly
reducing the cost. However, carbon resistors tend to undergo changes in resistance with age and also have a tendency to
change in value when subjected to overload. Therefore, an instrument which reads
accurately when new may become quite
Medium Priced Meter Used
The writer is of the opinion that an instrument having a resistance of 2000 ohms
per volt is of sufficient sensitivity for all
ordinary purposes, and at the same time will
result in multiplier resistor values which
are economically feasible.
The universal test meter described herein
was built around a 4" Triplett 500 microampere meter. One reason for the choice of
the 500 microampere unit was that this
was about the lowest current meter which
would operate satisfactorily with a meter
Front
Wiring diagram for the all-around test meter. which, with ifs rectifier,
permits A.C. and D.C. tests.
MnER
.,
M CTE R
,,J
ADJUSTING
(A.0
-0C
SWTC)
f
a__________
________
lZPOt.E 24P01NT
ROTARY SWITCH
CNL 17 PO5ITIN5
I
I
METER
RECTIFIER
-
+
45V
BATT
,,flVVV
MA.
SHUNT
NOTE C"/2W. ME1ALIZEO(BT/Z) RE5ISTOR5.
ALL OTHER RE ISTORS ARE
PRECISION TYP W.W 2 S W.W.4.
SOMA
SkUNT
ARE USED.
D.c. ranges
of O to IO, 50, 250, 1000 and 2500 volts
at a sensitivity of 2000 ohms per volt.
Current ranges are 1, 10, 50 and 250 milliamperes D.C. Three resistance ranges are
incorporated in the instrument using a
built-in 4Y2 volt battery and provision has
been made for connecting an external 224
volt battery for reading very high resistance values. All these values can be read
directly from the meter scale.
This meter has both b.c. and
SHUNT
40000UM5
(NEEDED
W.EN
meter
Measures Both A.C. and D.C.
5T4NÓARD
MIC4PER
MCAMPERE
view of the handsome fest
described in this article.
+
I
SMA
t5MEG\
fz.so
5OMA
P
(EACH)
1MEG.
o
5.7
ç
MEG
5oM4J
í000v
25::
f
M3
I
I
:4VL
:
i
.
SOMA
SHUNT.
'4
Z5OMA.
SHUNT
MF
I
MEO.
,/OHM5
-.\PT
4j
.-.-.-.-.-.
-H
25.000
I
80.000
20000
OHMS
R-EXT
.
I
OHMS
GANGED
-
s
i-ptjt
-
SWITCH)
New Meter Scale Provided
Since no ready-made scale VLS available,
it was necessary to have one drawn especially for this instrument. A ftill size facsimile is reproduced and can be cut out and
pasted over the regular metal scale. When
removing the regular metal scale, be extremely careful not to bend the meter
pointer. Paste the new scale over the metal
scale, being careful not to have any wrinkles
¡n it and replace in the meter. This operation should be performed some place where
there are no air currents, as a little dust
in the meter movement will cause some
stickiness.
RADIO & TELEVISION
738
www.americanradiohistory.com
fa
illy
and
Ave ALLIED'5Ji,4,,irq (ta/oq
Brings you everything new in Radio
cheaply Guilt
G
DEALERS
SERUI[ERIEtl
AMATEURS
BUILDERS
ÇPt //our aple
y anyone
ATPpO
ES
T
SOOnD SPECIALISTS
zday'
NEW SETS!
Now in ALLIED', brand
new Spring Catalog, sec
the new Knights, with
ariPush-Button T b t s
Magnet"
newest buut ,--
aerials, newest featuresat prices never before pos--
sible! 60 Models, some as
AIR- MAGNET
low as $6.95 -AC, AC -DC,
RADIO
I t4, Volt, 6 Volt, 32 Volt,
-
portable and auto sets
and radio's biggest line of
P h o n o- Radius,
graphs, and recordphonoplayers! All backed by an
ironclad guarantee! See
many "specials" "Pee
Wees," "Magic Wireless" record players, etc.
For real radio profits,
send coupon now!
-
NEW
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8
to 65
watts- standard
SEMAI.
new e
all t h
ó : Ha11>:T
--
and de luxe
-permanent, portable and
mobile
Monitor Speakers,
Remote
pMp1EUR
,
o
LOW -COST
AUTO -RADIO
Control
also complete recording
discs, accessories; read all equipment,
new low-priced "Flex-disc"! about the
gatlns
s
a
dRM
es,sthe pnw
pationiow°
tnttor
'FCC
aten
L
Leading
EVer
--all
pricesL
Rear view of the test meter, showing the
resistance units.
teur
t
NEW TESTERS!
The panel size shown in the drawing is
about the minimum possible and need not
be strictly adhered to. If a cabinet of different distensions is already available, use a
panel to lit it and re- arrange the parts to
make a well balanced layout.
Not Necessary to Change Test Leads
As reference to the diagram will show.
there are only two tip jacks, obviating the
necessity of moving test leads to different
jacks when it is desired to change from
voltage to current or to output or to ohms.
The two small switches under the meter
are an A.c. -n.c. three -pole, double -throw
jack switch used for connecting in the
meter rectifier for reading A.c. voltages and
the single -pole, single -throw jack switch
which shorts out the built -in .5 mf. condenser used in measuring receiver output
voltages. Between these two switches is the
cero olsius adjuster. Incidentally, the resistors in the ohmmeter circuit are of the
watt metallized type, since they are not
required to maintain the rated resistance
values. The ohms adjuster takes care of
any deviation from the correct and needed
value. The main selector switch is a special
Mallory 2 -pole, 24 -point rotary switch, not
all of whose contacts are used, leaving several for any additional ranges to be added
at some future time.
Reference to the photos will show the
method of mounting the various components. The .5 mf. condenser and the 41/4 volt
battery are fastened down by means of large
size fuse clips or Mallory FPM -l4
(Continued on paie 745)
for April, 1939
New equipment with pro vision for new Loctal
Tubes, etc.
leading
lines of tube checkers, set
testers, analyzers, oscillographs, etc. -and over
11.000 parts at lowest
prices, in ALLIED's new
-all
catalog!
ALLIED Radio Corp, Dept. 3 -D -9
833 W. Jackson Blvd,, Chicago, Ill.
) Send me your new FREE Radio
I
Catalog for spring.
ALLIED
(
)
Enclosed find 10c (plus 3c postage) for Radio Builders' Book.
Name
Address
CORPORATION
City
State
See Pages 752, 738 und 766 for Interesting Subscription OfJi'r.'
Yo
O
otteY
rtotYoo
BRUSH
HIGH LEVELER SERIES
Y
%to'
MICROPHONES
Range in price from
$22.50 to $32.50
New Brush Headphones
Write for your Brush catalog today
THE BRUSH DEVELOPMENT COMPANY
3326 PERKINS AVENUE
CLEVELAND. OHIO
Catalog upon request
BLAB MFG. CORP. 599 Broadwa Naw York
FI,,_.- s:.
RADIO
8
TELEVISION
www.americanradiohistory.com
739
being played is heard through the receiver. This
adjustment should be made carefully so that the oscillator is
exactly in tune with the receiver. In cases where the receiver
cannot tune to 540 kc., any other clear channel up to 740 kc. may
the record
211QJticrn I/OX
Vertical Autenon
Unfortunately, I have
stored into a new location
where I find it impossible to
VERTICAL
ANTENNA
12,
an
antenna cannot
2
SET
'RADIO
SET
ÁIRRÉ57pRR
1 -2
Meter Transceiver
iII -ill you please publish a diagram of a 21/4 meter transceiver,
one using the two volt type tubes namely, a 30 and a 49. The
transceiver should be for battery operation and should show all
the necessary parts needed.-Walter Hooker, Winnipeg, Manitoba, Canada.
A
be
used. In fact, a prominent radio
manufacturer has recently
brought out a vertical an-
Where sufficient signal is not received at the receiver, due to
undue static or stormy weather, couple an insulated wire from
the set antenna post to the free lead on the record player line
cord. Do not make positive contact with this line cord wire,
merely twist the two insulated leads together.
TO
RADIO
erect an outside antenna. Can
one of the new type vertical
antennas be employed?-Larry
Hamsley, Hoboken, N. J.
A. There is no reason why
such
MMF
be used.
tenna for home use. It conDiagram for Vertical antenna,
sists of a 12 -foot vertical rod.
No. 1174.
Attached to one end are two
special insulators and metal straps. The straps are so constructed
that they may be easily strapped or clamped around the roof
top vent pipe or any similar protrusion. Also it is possible to
mount the clamps on the outside of the building.
A single wire connected to the vertical connects it to the radio
receiver and lightning arrestor. Connection to the radio receiver
is made through a 2000 mmf. condenser in order to isolate any
charge picked up by the vertical. At the same time it allows
radio frequencies to pass freely to the receiver. The arrestor and
coupler are shown.
The 99.000 ohm resistor acts as a leak for any static charge
which might build up on the antenna and lead -in. The value of
the resistance is sufficiently high so as not to affect signals picked
up by the antenna proper. A gap -type arrestor connected across
the resistor discharges the antenna on large static charges to
ground.
Remote Record Player
Is it possible for you to print a diagram for a remote record
player? This player should have a crystal pickup and at least one
tube as amplifier.-Harold Morgan, Saginaw, Michigan.
A.
A schematic of such a player unit is shown here. A crystal
pickup feeds its audio output into the Number 1 grid of a 6A7.
Grid Number 2 has a positive voltage applied to it through a
5000 ohm resistor. The remaining elements are so arranged as
to become an oscillator, operating in the range from 540 to 740 kc.
The coils Ll are used to determine the frequency of oscillation,
tuning being accomplished by a 40 -250 mmf. trimmer. Con aired
Here is a diagram of a 2% meter transceiver. It can be built
into a compact carrying case. Miniature dry batteries can be used
and in spite of their small size they should give approximately
8 hours continuous service. A 4 -pole double -throw anti- capacity
switch changes the circuit from SEND to RECEIVE.
Two -volt type tubes are used: a type 30 and a 49. The circuit
diagram shows the values of the parts needed. From the circuit
diagram it is seen that the 30 type tube is used as a super regenerative detector in the receiving position or as a modulated
A.
u,
30
i
o
rOH,.IS
\M
R
MM
T
.002MF.
J--.00000
p
RFC
)
H
OOF-
.002MF
L2)
Transceiver for 2.5 meter communication, No. II 76.
oscillator in the transmitting position. The 49 tube serves as a
tetrode audio amplifier for receiving and a modulator tube for
transmitting purposes. Transformer Tl serves as a modulation
transformer for transmitting and an output transformer for
receiving. The R.F. choke is the 2% meter conventional type. The
tuning coils needed are Ll and L2. Ll consists of 4 turns of
number 12 wire tapped at turn 1. L2 consists of 4 turns number
12 wire and tapped at the center.
Veri Cards
How does one go about getting "veri" cards from foreign
stations? -L. J. Hallos. Brooklyn, N. Y.
A. Merely
make a note of the time. date and character of the
program received. This, together with an International Postal
Reply coupon should be sent to the station, together with a
request for verification.
Response Range of HI-FI Set
in the line cord is a length of wire which extends from the cord
few inches from the plug end. The other end of the wire is
coupled to the grid of the oscillator circuit through a 10 mmf.
condenser. This wire serves to radiate energy generated by the
Con you informs one of your ardent readers what is the
response range of a so- called high- fidelity receiver? -M. K.
Laboring, St. Louis. Mo.
A. A high -fidelity radio receiver should be capable of reproducing frequencies from about 30 to 8000 cycles or higher. The
RMA defines such a receiver as one that has a frequency range
of from 50 to 7500 kilocycles, with not more than 5% harmonic
oscillator.
A 25Z5 is used to supply power to the 6A7. The rectified voltage
is capacity-resistor filtered. The phono motor is shown at the
lower left.
To operate the unit, tune any receiver to 540 kc. With the unit
in operation, carefully adjust the 40 -250 mmf. condenser until
A fee of 25c (stamps, coin or money order) is charged for letters that are
answered by mail. This fee includes only hand -drawn schematics. We cannot
furnish full -size working drawings or picture layouts. Letters not accompanied
by 25c will be answered on this page. Questions involving considerable research
will be quoted upon request. Flames and addresses should be
clearly printed on each letter.
Hook -up for remote "record player ", No. 1175.
a
distortion.
740
RADIO
www.americanradiohistory.com
&
TELEVISION
New
HAM
Licenses
COMPILED FROM THE LATEST RECORDS OF THE FEDERAL
COMMUNICATIONS COMMISSION
THERE are now approximately 50,000 licensed radio amateurs in this country. And dozens of new amateurs are being licensed every month.
Heretofore no publication has listed the names and addresses of the new
licensees as issued. RADIO & TELEVISION Magazine now provides this
unique service, and publishes a list of newcomers in every issue. Check the
names carefully so that you will be able to get in touch, not only with
amateurs in your neighborhood and vicinity, but also with those distant amateurs whom you wish to contact either by mail or by radio.
This list contains 85 names of newly licensed amateurs. YLs' names
appear in blackface type.
K7FAK
WILSC
Victor
Ross, Coliseum Apts., Apt. M,
B.
Juneau, Alaska.
Leonard Rubin, 16 Almont St., Malden,
WBSSM
Oney, 617 Herrick Ave., Wellington, Ohio.
John E. Kimar, 2060 W. 41, Cleveland,
WBSSN
Stephen A. Hoynos, 848 Dana St., Warren,
WBSSE
Mass.
WILSD Wm. A. True, 97 Myrtle St., Waltham, Mass.
WILSE Harvey J. Jacobson, 35 Homestead St.,
WILSF
W2BEC
Roxbury, Mass.
Joseph W. Sheehan, 436
Mass.
John A. Friel, 134 -03 95th
Hill, L. I., N. Y.
Sea St.,
Quincy,
Ave., Richmond
Wm. Weingart, 201 Allen St., New York,
N. Y.
WILUD Gideon Van W. Stivers, West Main St.,
Riverhead, N. Y.
W2LTW Sylvester Montecuollo, 97 St. Pauls Ave.,
Jersey City, N. J.
W3HWX Howard M. Shade, 7 Russell Rd., AlexanW2LUC
dria, Va.
Calder C. Murlatt, Jr., 2008 Swatara, Harrisburg, Pa.
W3HXA Norman Tuip, 7025 Clinton Rd., Upper
Darby, Pa.
W3HXB Joseph H. Snyder, Elm Ave.. East Millstone,
W3HWY
N. J.
W3HXE
George E. Schellhes, 726 Grentley St.. Baltimore, Md.
W4ACO Robert Van Sleen, 221 S. Marietta St.,
Gastonia, N. C.
W4FUB Jones C. Tipton, 809 Lamar Ave., Charlotte,
W4FUD
H. Turner,
254
Church St.,
Macon,
Ga.
W4FUE George Wentz, R.F.D. No. 3, Hickory, N. C.
W4SY Samuel Sayler, 10 S. 3rd St., Fernandina, Fla.
WSHPO Earl E. Ordway, U ^it 3, Sec. 8, U.S.N.R.
c/o Nat'l Guard Armory, Ardmore, Okla.
W5HPQ Walter M. Mayer, 2106 Frio City Rd., San
Antonio, Texas.
W5HPS Clarence Scott, 131 S. St. Patrick St., New
Orleans, La.
W5HQA Clarence Traylor, Kernel,, Texas.
W6EJD Kenneth M. Curtis, 27 -13th St., National
City, Calif.
W6GKR Clifford L. Johnson, Oakland Way, Emerald Lake, near Redwood City, Calif.
W6LYL Jay D. B. Lattin, Signal Corps Unit, New
Men's Gym, Univ. of Calif., Berkeley,
Calif.
W6QQM Walter Nestler, 2055 Del Mar Ave., San
Marino, Calif.
W6QQN Sta -ley C. Hall, Trustee, Mission Radio
Club. 1394 Villa St., Mountain View,
Calif.
W6QQP Hebert Woods, 2625 Carlton Place, Riverside, Calif.
W6000 Edwin S. Reiten, 1947 W. 43rd St., Los
Angeles, Calif.
W600R Leonard F. Melsha, 8416 San Carlos, South
Gate, Calif.
W6QQX Rexford R. Haslam, 1071 N. Angeleno
Ave., Burbank, Calif.
W6QQY Charles W. Worman, 140 N. Louise St.,
Glendale, Calif.
W6QUA William Sharp, 731 S. Chapel St., Alhambra. Calif.
W60UB Robert Ullery, Rt. I, Neal Rd., Paradise,
Calif.
W6QUC Francis D. Wells, 340 Hayes St., San
Francisco, Calif.
W6QUE Lon M. Hildebrand, 682 N. Central Ave.,
Stockton, Calif.
W6QUF LeRoy W. Jillson, 811 East F St.. Colton,
Calif.
W6QUG
Richard E. Fricks, 4534 Idaho St., San
Diego, Calif.
W6QUTO Freeman F. Gosden, 900 N. Alpine Dr.,
Beverly Hills, Calif.
W7AAQ Jack W. Worley, 5616 N. Wall St., Spokane,
W7HS
Ohio.
W8SSP
Wash.
Oscar A. Schwartz, S. 3010 Lamont, Spokane,
Wash.
Joe H. Van Wie, 5534 Marlborough, Detroit, Mich.
W8JZH John F. O'Shea, 1057 Albert, Toledo, Ohio.
W8SRL George M. Hudimar, 1597 Hopkins Ave.,
Lakewood, Ohio.
W81PO
for April, 1939
Ohio.
George Reinhart,
210
Main St., Stroudsburg,
Pa.
James
Sackrider, 529 Clark Ave., Owosso, Mich.
WBSSR Gregory W. Sawmiller,
121
E.
Corning
Ave., Syracuse, N. Y.
W8SSS John J. Schueler, 32 Worcester Pl., Buffalo,
W8SSQ
B.
N. Y.
Thaddeus F. Dudek, 6722 Fullerton, Cleveland, Ohio.
WBSSU Russell E. Geiger, R.F.D. No. 4, Youngstown, Ohio.
W85SW Ralph L. Archbold, 1195 E. 146th St., Cleveland, Ohio.
W8SSX George Weinrich, 306 W. McClellan, Flint,
Mich.
W8SSY Corby Stone, 518 Rawlins St., Port Huron,
Mich.
W8SSZ Kenneth Huggett, 22 Reading Ave., Hills.
Completely revised and enlarged
Spring edition of the greatest catalog
in radio -out now. Send for your copy
at once. It's FREE! Tear off coupon
below and mail.
WBSST
W8STA
dale, Mich.
Herbert F. Keith, Wanakena, N.
W8STB
Ralph
WBSTC
N. C.
John
Ernest
Y.
F. Stadt, 4927
Dearborn St., Pittsburgh, Pa.
Windsor F. Hernenway, 130 N. Erie, Mercer,
Pa.
W9AAP
W9BMY
W9EBD
W9ESB
W9JPF
Jess,, W. Foster, 6834 Roberts,
City, St. Louis, Mo.
University
James W. Justice, 5803 A Michigan, St.
Louis, Mo.
Elliot D. Full, 529 Hawthorne Lane, Win -
ith this
-
son. Ind.
W9JZH
Clifford
E. Johnson,
1409 5th
Ave., Des
Moines, la.
M. Leidholdt, Trustee, Chippewa
Q.R.R. Club, 101/2 Jefferson Ave., Chippewa Falls, Wisc.
Anthony T. Maruca, 4827 18th Ave., Keno.
sha
Wisc.
Roland R. Petersen, Iota 9810, Block 3,
Flaxton, N. Dak,
Vernon E. Rardin, 212 Lombard Ave., Muscatine, Iowa.
H. Louis Robinson, 1306 Waverly Ave.,
Kansas City, Kans.
Robert H. Oberman, 1303 San Pedro, Trinidad, Colo.
Clarence Rasmussen, 656 Utica St., Waukegan, Ill.
Peter P. Viezbicke, III Ilth St., So.. Virginia, Minnesota.
Robert Wm. Yeager, 30 N. 3rd. St., Madison, Wisc.
Edwin P. Westbrook, N. W. corner 2nd
S 8 Swift Sts,,
Winnebago, Ill.
Chester D. Walters, 701 Prospect Ave.,
Wausau. Wisc.
Cyril Strehlon, 499 Grotto, St. Paul, Minn.
Robert J. Spellman, 2586 Crown Point,
Omaha. Nebr.
Bennett L. Jackson, C.C.C. Co. 3541 Camp
W9NOQ Carl
W9NPK
W9NQU
W9NRC
W9NRL
W9NVU
W9NWY
W9NXB
W9OAV
W9OBP
W9OBZ
W9OCF
W9ODC
W9ODM
S.C.S. 5, Walton, Ky.
George Zurian, 13641 Chatham St., Blue
Island, Ill.
W9OGR Clifford F. Susag, 415 7th Ave., East Alexandria, Minn.
W9OPX Helen M. Kolar, 59th & Marion, R.F.D. No,
2, Downers Grove, III.
W9OQZ Wm. C. Haggard, Jr., 1605 Joesting, Alton,
III.
catalog today.
Hers-ttecO1,,Lal
SIN
CORRECTION NOTICE
The call of F. V. Frost, 4548 47th Ave., Seattle,
Wash., was incorrectly given as W7HCO in the
March issue of R 8 T. Mr, Frost's call should have
been listed as W7HCU.
Please say you saw
it
in RADIO 8 TELEVISION
www.americanradiohistory.com
MI
FOR YOU
there's o section packed solid with
up -to- the -minute gear at down.toearth prices. Plus the scoop of the
year -Frank Lester's revolutionary
new 5 -10 converter. Tear off coupon and mail at once.
ADDITION -60 stunning new radio
models, kits, ports, tubes. Mail the coupon.
YOUR FREE COPY IS
LAFAYETTE
W9OEZ
*Freeman Gosden (W6QUT) is known to millions of
radio listeners as the "Amos" of "Amos 'n' Andy".
issue Lafayette an-
nounces a great new line of sound systems
for 1939. Here is revolutionary P.A.-new
in smoother, finer performance, new in
streamlined styling, new in operating economy. And for the first time, 3 distinct fines
for you to choose from
Economy, Stand.
ard and DeLuxe. Truly Lafayette can offer
this year a sound system for every purse
and purpose. Complete range in all three
lines from 5 to 70 watts. If you sell or rent
sound systems, or if you've ever considered
this highly profitable field, be sure to see
what Lafayette has for '39. Send for FREE
retka, Ill.
Homer C. Cutler, 818 S. Marion St., Carbondale, Ill.
Charles F. Pippen, 15 W. 12th St., Ander-
AND
Of DIO
COOP.
WHOLESALE RADIO SERVICE ea
NEW YORK, N. Y.
I
WAITING!
CHICAGO, ILL.
ATLANTA, GA.
'00 Si Y TH AVENUE
SOI W JACY.S'DN BLVD
255 PEACHTREE Sl.
BOSTON. MASS.
BRONX. N. Y.
NEWARK, N. J.
JAMAICA, L. I.
Rush New FREE Radio
Catalog No. 76.
1
I
Nome
PLEASE PRINT
I Address
City
1
Stale
LAFAYETTE RADIO CORP,
1
1
Dept,4D9 -100 Sixth Ave., New York, N. Y.
741
Fig.
Panel view of the new Silver Super. Complete control of all
1.
functions
A
is
provided.
New Type or
Fig. 2. Top of Chassis. Points to note include attractive
and geared tuner.
layout
COMMUNICATIONS
Receiver
McMurdo Silver
Built from standard parts, or wired from a factoryassembled kit, this receiver introduces many new features.
THIS new communications receiver follows closely the designs
prescribed by the A.R.R.L. as the means of providing the maximum of results at a minimum cost. It goes considerably beyond
these earlier designs in that it includes a new noise iirniter which
is as effective as it is simple, covers the full range of 5 through
550 meters with sensitivity of about 1 microvolt absolute throughout, has the highest signal -to-noise ratio of any receiver the writer
has ever operated, is completely free of "warm -up" drift, is both
"portable" (battery operated) and "permanent" (A.c. operated)
in the same unit, can be expanded into anti- fading dual -diversity
reception at no increase in size, yet can be built to "battleship"
ruggedness by even a novice to use from three to eight tubes with
maximum complete chassis cost below $50.00. Capable of being
built from standard parts, it is also available as a completely
assembled 8 tube kit, requiring only a couple of h( urs to wire and
test. It can be aligned and tested without any service gear whatsoever, although a test oscillator (borrowable from, or usable at.
Fig. 3.
any local service shop) makes the task most easy and sure -fire.
When this receiver also has A.v.c., six low -C tuning bands, uses
the newest all -glass "Loctal" tubes, has nearly twenty-two inches
of effective dial length per band readable to one part in 5000
which can be stretched to eleven feet per band at slight extra
cost-selectivity continuously variable from 12 kc. "high-fidelity"
right up to sharper than the 1 kc. necessary to single -signal c.w.
reception, 4.25 watts undistorted power output, and appearance
and controllability which are outstanding even among very expensive communications receivers, it comes close to being the ideal.
Yet this is what numerous Chicago amateurs, young and old, who
have tested the new "Silver Super," have found it to be.
-
Regeneration Put fo Work
of this is made possible through regeneration, amazingly
neglected considering its tremendous benefits by factory -built
(Continued on page 749)
All
Wiring diagram of Silver Super. It can also be assembled
as
a
"3 -tube set",
described herewith.
as
PHONE JACK
TAT
7A7
6V6G
.05
MF
MEG.
TRIM
~I
IT
OHM
NI F.
CONTROL
0.25
MEG.
ME.
.DM0F1-
MÉG
A.V.C.
SW.
r325
SP'K R
OHMS
MF
NOTE: DOTTED LINES FOR
A.C. OPERATION
OHM
105 10V.
50-
SV=
100
NOTE:
MME.
AI.F.
VR150
T
GAIN
B
0.5-
MEG.
(EACH)
CONTROL
C. NOISE
LIMITER
CONTROL
D. REGEN.
CONTROL
742
o
0
50.000
:1%
OHMS
ME
8.0.5W.
0.1MF.
6.9vó
r
;TO
SW
(C)
OHMS
RADIO
&
TELEVISION
All -Wave 8 -Yule
Receiver
(Continued front page 737)
half of the tube acts as an automatic noise limiter of the modified Dickert type. This
type of noise limiting is very effective on
noise pulses whose amplitude is greater
than the desired carrier signal. Two de-
When a pickup is plugged into the phono
jack, the R.F. section is automatically disconnected from the audio. Another jack
located on the rear of the chassis permits
the listener to use headphones. The 6V6
audio power tube is automatically disconnected when listening -in with phones.
The I.F. transformers are of a rather unconventional type. Instead of the trimmer
condensers being adjustable, the transformers have fixed condensers and adjustable
inductance coils. This is an extremely valuable feature for the ordinary type of adjustable mica trimmer varies in capacity
with temperature, humidity and vibration.
By varying the position of the Polyiron
cores in the coils, the inductance is adjusted
to the proper value and, once set, the I.F.'S
will remain permanently aligned.
grees of noise limiting have been made
available; one for use in copying cw (telegraph) signals and the other for listening
to phone signals. This is switched in automatically when operating the combination
avc -itou switch, about which more later.
Tube Acts as 1st Audio and B.O.
6C8G dual triode is used as a first
audio stage and as a beat oscillator to enable the listener to copy cw telegraph signals and to facilitate locating weak vx
stations. The aro transformer contes complete with a built -in grid condenser and
resistor. The condenser shown coupling the
plate of the BFO half of the 6C8G to the
plate of the 6H6 detector is made by merely
wrapping about five or six turns of hookup
wire around the lead running from the I.F.
transformer to the 6H6 plate.
Getting back to the rather unusual
method of .VC -BFO switching: a single Opole, 3- position rotary switch is used for
controlling all the various features of the
receiver, the 110 volt A.c., the AVC, BFU, and
the degree of noise suppression. As the
diagram shows, in position 1 the receiver
is disconnected from the 110 volt line; in
position 2 the set is connected to the line.
Ave is switched in, BFO switched off and the
noise -limiter adjusted for action on voice
signals. In position 3 the Avc is cut off, the
BFO turned on and the noise -limiter adjusted
for its greater limiting action for use on
cw (telegraph) signals.
I
.\
Switch Coil Assembly
All the R.F. coils, mounted on a six gang,
5 -band switch, are adjusted to exactly the
proper value of inductance at the factory
and the trimmer condensers are adjusted
for correct "tracking" in the receiver. However, a little readjustment will be necessary
in the individual receiver. Although complete coil information is given in the chart,
it is inadvisable for the constructor to
attempt to make these coils himself, because
of the great difficulty in getting the coils
for each band to have the proper inductance
to "track" properly. So the purchase of the
complete coil assembly is strongly advised.
Incidentally, the small variable trimmer
condensers shown in the diagram across
each coil are of 12 'miff. maximum value.
Between the antenna and R.F. sections and
between the R.F. and oscillator coil sections
a metal shield is placed.
Head-phone and Phono Jacks Provided
The 15,000 ohm potentiometer simultaneously controls the gain of the 1853 and
the 6S7 tubes, providing effective control
against overloading the detector by any
strong "local" signals. A phono jack has
been incorporated so that the audio section
of the receiver can be used with a phonograph pickup. A half mcgohnl "pot." permits complete variation of audio power.
the trimmers on the R.F. coil assembly, tune
in a station emitting a signal of approximately constant amplitude; an aviation
(Continued un following page)
n el
t. No.
length
None
ntcters)
(air wound)
t
prim. 3r., t. No. 36
DSC interwound at
ground end of sec.
secondary IO s, turns
5.85.18.2 mc.
(51 to 16.4
meters )
No. 18 spaced
444"
10;: t. No.
print.
SSE
1.74 -6.45 mc.
sec.
(172 to 46.48
meters)
.lf"
diam. form.
34'/
14
on
or
Oscillator
-pnccd to
'
dia.
_
-turns
sec. 10% t. No. 18 spaced
to 3n'
prim. 7'.: t. No. 36 DSC
interwound at ground end
of secondary
34" dia. foret
36
t. No. 28
both coils close wound
and separated by yö"
wound on ))4" dia.
prim. 15;ßs t. No. 36 SSE
sec. 34yí t. No. 28 enamel
4}" dia. forth
grid coil
prim. 254t No.
38 SSE
5/44 SSE
universal wound on
34" dia. forni
sec. 91
meters)
t.
3
i'
1
t.
spaced to
7/16"
grid coil
1044
No.
14
plate coil 4 turns No. 36
SSE interwound with grid
coil
coils 4" dia.
spaced to 3/4"
t. No. 18
plate coil 6 turns No. 36
DSC at grid end of grid
coil
grid coil 30% t. No.
28
enamel
plate coil 10'.. t. No. 36
SSE. both close wound
4ÿ" «lia. form
An indispensable radio instrument
for every ham, serviceman and experimenter. Fuse protected, fool-proof,
guaranteed. Dozens of uses. Determines resistance values; estimates
tapers and values of controls; serves
as voltmeter multiplier. rheostat or
potentiometer; voltage divider; calibrated gain control or attenuator, etc.,
etc. Direct reading dial. Only 1 knob
adjusts resistance from 0 to 1.0 megohm. Bakelite case 41/4 "x31/4 ". Three
fuses. Interesting 16-page instruction
manual supplied with each Analyzer.
Net -Price (complete)
.... $4.95
All Metal
long x
S'/a" deep x
S1/2" high
11"
prim. 528 t. No. 38 SSE
sec. 93 t. No. 3 5/44 SSE
coils spaced 3 /16"
wound on 34" die. form
RADIO'S HANDIEST
PARTS CABINET
This new All -Metal IRC RESIST
O- CABINET contains the first really
balanced resistor assortment. Supplied
complete with 59 famous IRC Resistors
in practically every type and range
commonly used in service work. You
pay only the standard prices for the
resistors. The cabinet is yours at not
one cent of extra cost. The 59 resistors
include popular ranges in 1/- and 1
watt Insulated Metallized Resistors;
also 10 -watt fixed and adjustable wire
wounds, the latter giving every range
from a few ohms up to
10,000 ohms. Cabinet contains four large drawers
with seven compartments
0
in each. Designed to stack
solidly, one atop the other.
List Value of Resistors S1S.16
(The Cabinet is included)
NOTE: Radst- 04ablset est mild empty.
INTERNATIONAL
t. No. 32
32" wi de
plate 30 t. No. 32
gr3/id
530 -1800 kc.
(565 to 166.6
FOR USE WHEREVER
RESISTANCE MEASUREMENTS
ARE MADE
Aligning the Receiver
Antenna
13.5-42.5 mc.
(22.2 to 7
ANALYZER and INDICATOR
Lining -up the receiver is not particularly
difficult, even without a signal generator.
First, the two I.F. transformers must be
aligned to 456 kc. Without touching any of
COIL CHART
Ifarld
RESISTANCE
62
3/32" wide
SSE
RESISTANCE CO.
SSE
401 N. Brood St.,
Philo., Po.
both coils close together
universal wound on
h"
«lia.
sec.
SSE
prim.
SSE
132 -405 kc.
(2306 to 740
meters)
NOTE: No.
for April,
492
No.
t.
715
t.
3 -41
No. 38
V," wide
wound on %" dia
form
universal wound
each coil
3
-41
1939
SSE and
3
print. 1305 t. No.
3/16" wide
%sec.
492 t. Nu.
" wide
38
SSE
3 -41
SSE
coils spaced 5/16" apart
universal wound on %"
«lia.
grid 217 t. No.
3/16" wide
32
SSE
plate 69 t. No. 32 SSE
3/16" wide
coils close together
universal wound on %"
dia.
7)?,eta.[lilect
RESISTORS
STANDARD OF QUALITY EVERYWHERE
5/44 SSE wire is Litz (stranded) wire.
Please say you
saw it in
RADIO
&
TELEVISION
www.americanradiohistory.com
743
All -Wave
HOWARD
pize4ed,
DX 10
ON
8 -Tube Receiver
onlinued from preceding page)
beacon station is ideal. Then merely adjust
the i.e. coils until the signal is at a maximum. To line up the front -end of the set,
start with the lowest frequency band. Tune
in a signal at the high frequency end of the
TUNING
INDICATOR
band, preferably a signal of known frequency, and adjust the oscillator alignaire
(trimmer) so that the frequency of the
''AUDIO
(TUNING J
signal corresponds to the frequency printed
ZB.F.O..
A.V.C.. CONTROL f
CONTROL
R.F.
on the dial scale. Adjust the antenna and
A.G.
GAIN
detector coil trimmers for maximum re- CONTROL SWITCH
SELECTOR
SWITCH
sponse. Then tune in a signal at the low
frequency end of the band and adjust the
POWER
oscillator padding condenser while rocking
TRANS B.F¡.0.
8C6Ca
eH6
FORMER
the tuning condenser to obtain maximum
response. The oscillator padder is the conTUN NG COND.
,rte
denser in series with each oscillator coil.
L¡,
The above procedure should be repeated
2ND.
L.F
for each band. On the highest frequency
OSG.
CHOKES
band there are no aligning or padding con densers, the coils being adjusted by spacing
DET.
657
the end turn to give the desired amount
1653
of inductance for tracking.
ANT.
(C
1`
METERS
ELECTRIC BAND SPREAD
U
15T.
Parts List
INTERNATIONAL RESISTANCE CO.
15.000 ohm potentiometer. type 14-118
500.000 ohm potentiometer, type 11 -133
500,000 ohm, y: watt BT'/:
100.000 ohm, 54 watt BT%
75.000 ohm, Vt watt BT;4
50,000 ohm, Vs watt BT
3 -2,000 ohm, % watt BT%
1 -1,500 ohm, 'A
watt BT%
10 watt type AB
1 -235 ohm.
20 watts
1 -3,500 ohms,
15.000 ohm. 20 watts
2 -300 ohm, % watt BT'''/
1 -150 ohm,
watt BT'A
1 -50
ohm, y watt BT'S
I.
F.
3534-
1-
THE SCOOP
RCA RADIOTRONS
1- -1853
of the
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Check these outstanding features; 4
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AMERICA'S OLDEST RADIO MANUFACTURER
Complete Technical
Details Send this Coupon
FREEFor
HOWARD RADIO COMPANY
1735 BELMONT AVE.. CHICAGO. ILL.
Gentlemen:
(
)
(
)
Send me Booklet No. 430.
I desire a demonstration.
My name is
Address
City
744
State
-6V6
-5Z4
'8x61(8 MP
'
DIAL
11-
1
ELECTROLYTIC
Layout of panel and sub -base.
MEISSNER COMPANY
13.7600
1 -All -wave coil assembly
1
gang tuning condenser 410 mmf. No. 21-514111
1
Slide -Rule dial with brackets No. 23 -8206
Standard chassis No. 11 -8226
11 -8221
1 -Panel No.
1-- Cabinet No. 11 -8221
4-Ceramic octal sockets No. 25 -8437
Bakelite octal sockets No. 25.8209
4- -11A" knobs No. 25 -8224
I --1 W knob No. 25 -8225
1- -Magic eye socket assembly No. 19285
ALADDIN RADIO INDUSTRIES
1-465 kc. I.F. transformer type P -101
1-465 kc. I.F. transformer type P -200
1 -a1,0 transformer, 465 kc. type C -350
-3
-9"
1-
3-
CINAUDAGRAPH CORPORATION
--6U5
1
SPRAGUE PRODUCTS COMPANY
10 -.1 mf. 600 volt paper condensers type TC -1
1 -.05 mf. 600 volt TC -15
-.5 tuf. 600 volt TC -5
1-8 x 8 x 8 mf. electrolytic PLS -888
1
mf. 50 volt electrolytic TA -55
1
mf. 25 volt electrolytic HC.5
1
mf. 450 volt electrolytic RE -1
1 -.0001 mf.
mica IFItI -31
.00005 mf. mica 1F11-45
1
-5
-5
-1
1-
I
P.M. speaker type NZ10 -10 (with 5000
ohm output transformer)
P. R.
MALLORY
1-4 -pole,
rotary switch shorting type
3- position
No. 3143J
-2
circuit
-2 circuit
midget jack type A -2A
jack type No. 15
JEFFERSON TRANSFORMER CO.
1-350-350 volt transformer No. 463.431
- -10 henry 100 nia. chokes No. 466-410
1
1
COVER THE PACIFIC COAST!
This column has been added as a new service
to readers of RADIO & TELEVISION. Cooperation of Pacifie coast listeners and any reports of
reception will be greatly appreciated. Please address any reports or other correspondence to
Lyle M. Nelson, RADIO & TELEVISION. 99
Hudson Street. New York, N. Y.
(All time is Pacific Standard)
INCREASED activity among short -wave stations in the far East has been reported from
all parts of the Pacific Coast during the last few
months. Stations in Asia and Oceania have always,
particularly during this time of the year. occupied
the major part of Pacific Coast axing.
A New Zealand station has been reported testing
on 6.95 mc. by many listeners. According to these
reports the call letters are ZL2ZB and the address
is announced as: Hope Gibbons Building. Dixon
Street, \Vellington. Cl. New Zealand. The station
is heard in the early morning hours with best
reception near 3 a.m.
According to W. T. Choppen of Timaru. New
Zealand, new transmitters to be installed at Wellington will be ZLT1 on 6.085 mc.. ZLT2 on 9.54
mc.. ZLT3 on 11.78 inc.. ZLT4 on 15.28 mc.,
ZLTS on 17.77 mc., and ZI.T6 on 25.91 mc.
The mysterious Chinese station on 11.40 has
finally been identified as XGRV of Chungking.
This popular broadcaster is very well received
every morning front 4 to 4:30 and sometimes later.
Two other new Chinese stations to appear on
the air during the last month are XGXA on 6.98
mc. and XGXII (possibly XGXG) on 7.02 mc.
Both stations come through to the Pacific Coast
with good volume. XGXA is on the air front
6 to 7:20 a.m. daily. Occasionally it has been
reported as early as 4 a.m. XGXB (or G), although heard very well. is rather irregular in
schedule. It can usually be picked up in the mornings from 5 to 7.
Please say you saw it
-10"
in RADIO 8 TELEVISION
www.americanradiohistory.com
Portable transmitters located somewhere in the
jungles of Belgian Congo and New Guinea have
been reported on the 20 meter amateur band during the mornings and late evenings by George
Goehring of Oakland. California.
A new station in Siam has been putting a fair
signal through to the coast. The station works on
6.11 mc. from 5:10 to 7 a.m. on Wednesday. It
has also been reported broadcasting irregularly on
other weekdays. According to word from Siam the
call of HS8PJ has been changed to HS6PJ.
Application has been made by "Radio Burma"
of Rangoon for permission to use the call letters
XYZ and XZZ on 6.012 and 3.79 mcs., according
to John Cavanaugh of Oregon City. The latest
schedule for "Radio Burma" is from 2:45 to 5:30
a.m. and from 5:30 to 7 p.m. with best reception
during the morning broadcast, he reports.
Station RV15 of Khabarovsk. U.S.S.R., is back
on 4.27 mcs. after various reports had placed it
on 6.05 and 6.82 mcs. Latest developments seem
to indicate that the stations heard on the latter
frequencies were new stations and not RVIS as
believed.
ROUND 'N' ABOUT -from listeners' reports.
\-PD of Suva has added a number of new frequencies. It can now operate on 15.16, 11.89 and
6.13 mcs. with a power up to 10.000 watts. .
"Radio Hanoi" is using additional frequency of
11.91 mc. from 10 p.m. to 4 a.m. Station still very
weak on 9.51 mc.
. New
station TAO of
Ankara. Turkey. coming through weakly on 15.20
mc. from 2:30 to 4 p.m.
.
New TAP on 9.465
also reported on the air during afternoons.
Prague is now on 11.84 mc. from 4 p.m. to 6:15
with good volume. . . New Spanish Loyalist station
Radio Norte." EA4RM, on 9.49 after 6
p.m. with weak signal on coast. ZBW on 9.53 mc.
is still very well received from 5 to 7 a.m. .
PCJ coming through very well on 9.59 mc. during
evenings.
.
RADIO
&
TELEVISION
I'LL SHOW
This Universal Test Meter
nWi rued from paye 739)
C
54t'i4
A
4
3(d^I
mounting clips. The battery can thus 1..
readily replaced. The holes in the panel
fastening the meter should preferably be
tapped for 6/32 screws -this will greatly
facilitate mounting the meter.
1
f'
}6e-} á1-f5/6
.
A=%8"D.
B
9216
.
E
.
%4'O.
c=3iäo.
211a
D.
t6
Shunts May
/i6D
Be
YOU HOW TO MAKE
REAL MONEY IN RADIO
r
AND
TELEVISION
Home -made
The shunts used for the four current
F
F
ranges and the two low ohm ranges can be
Fs TAP
6
purchased ready made, or easily made by
FOR 6/32
SCREW
the experimenter, if one has access to antt5"
other millianuneter of the necessary range.
115
16
Shunts can be made from the resistance
wire procured from old rheostats or from
regular No. 24 or No. 28 resistance wire.
Fig. shows the method of hooking up the
fI¡
standard meter in series with our 500 microV
ampere meter, which is to be shunted with
1á-e1.1.
t4"
the home-made shunt. These two meters
22
must be hooked up in series with a battery
cf
( the 41/, volt battery will do) and a variaPqNEL ble current -limiting resistor. The 1000 ohm
zero adjuster can be used for the low current ranges; for the 100 ma. and 250 nia.
14"
8
ranges a 100 ohm variable resistor should
A
A
%4
he used. Adjust the length of wire used for
--0--.
! ..
the shunt until the 500 microampere meter
reads the same amount of current as the
MATERIAL'-%16"BAKELITE
standard meter. Always use the maximum
amount of series resistor until the shunt
COVER IS has assumed its approximate final resistWIG" DEEP
ance value.
OUTSIDE
7/8" DEEP
To measure A.c. or D.C. voltages, turn the
INSIDE
A.C. -D.C. switch to either A.C. or D.C. and
rotate the selector switch to the desired
range. If in doubt as to the magnitude of
-METER
CABINETvoltage, play safe and use the highest
range! With the A.C. -D.C. switch in the D.C.
" DEn/
position, current can be measured by rotatgE MATERIAL:8i2
ing the selector switch to the required range.
3/8" PLYWOOD-SI DES
'/4' PLYWOOD- TOP
TO MEASURE OHMS, have the
BOTTOM & PARTIT ON
A.C.-D.C. switch on D.C. and rotate the
i=MINI1111
IMfiBlllllIMIMlíllll selector switch to one of the resistance
ranges. For measuring very high values
40 IMMINIIII IM6111111iIN61111
MIN1111E1111 11<11111111121111111161111
turn the selector switch to R -ext. and con30
nect a 221/: volt battery in series with the
s3IRí11Í116161111
w
test leads. Scale readings should be multim 20 monies II
I Im1111m61111
ú
plied by 60 since the meter scale reads 900
w 1p
tIB1111IMBB1111
o
mIi11I11MIIBIIIIIINIM11111 ohms at the center of scale. When the
switch is turned to the position "R
0
10,"
IIIMEM\1I1IIMIENIMII111
merely divide the scale readings by 10 and
IO MEMNBIIIIIMINIIIM111IIIMWIIII
similarly when using the "R x 10" range,
10
20
50 00 200
500
multiply the scale readings by 10. For each
A.C. VOLTS
range, the ohms adjuster rheostat should
be adjusted so that with
the two test prods shorted
Above-Chassis and cabinet details. Below-Full
-Full size +sin- together,
the meter will
plate for meter dial: cut this one out for your meter or copy it.
read zero ohms. On the
_
R
10 range, this adE:2%äD.
16-
1
Professional
TEST EQUIPMENT
plus
35
-
.
:
:
.
J
.
EXPERIMENTAL
OUTFITS!
146
-.-Jr
RADIO TOOLS
/4~
Ali- Purpose. All -Waco
ANALYZER
.
\
MIIIII
MBIIII M1lr111111
ItiI11!iam1111
_won
BB1
i1111MI111II1111
MII
-
\
00 O
oqOñ
O O O
aI
toyoo
p
,t,lp
°° y°
ry
4
ti
50
C,
Off
100
0p
O
20
\
o°
g
150
30
i
4.0,3
UNIVERSAL METER
e/
`OO
RADIO& TELEVISION
O
for April, 1939
l
justment
is
I'll
Prove That
You Can Have
....
A GOOD JOB IN RADIO
OR A BUSINESS OF YOUR OWN
I offer
OUTPUT -Since
t he
you a1.new and altogether different
to
EASY to LEARN - - EARN
www.americanradiohistory.com
from the START
YOU DO PRACTICAL EXPERIMENTS with real Radio
Equipment
with your own hands. Thus the principles of Radio
tal.riear to you. The valuable
spare -time BUSINESS BUILDERS I s nl ly will show
You
njob
handling
profitble Radiot
edwhilee learning.
.
.
mite
NO PREVIOUS EXPERIENCE NEEDED
It
no difference what
ou
education has
My Training startss at the beginning of Radio.
simple
style all essential
Television.
Electronics. Facsimile
dio. Radio Set Repair and Installation.
been.
co
in
Rasubjects
READ WHAT THIS STUDENT SAYS
"Earned $250 Since Starting Course"
I
completed
the
Course and
fintl
interesting.
hs,nake reit
to learn.
a,,,i seerviciseveral
daily
tudy)
g I have male :lout
5250 gross since starting the Course.'
Earl W. Hostetter. R. No. 4. Lebanon.
Pennsylvania.
g
SERVICEMEN
I offer Advanced Training for those
i(ready in ltadio Get complete details
n
my FREE. 52 -page Rook.
REMEMBER -TNE SPRAYBERRY
COURSE IS SOLD UNDER A
MONEY -BACK AGREEMENT
DON'T DELAY!
ACT NOW!
SPRAYBERRY ACADEMY OF RADIO
F.
L.
245 -11
SI,rayberry.
Pres.
University Place, N.W., Washington, D. C. I
e d
FREE copy of "(WOW TO LIARE I
Please
MONEY IN RADIO...
I Name
output of a radio receiver IAddress
consists of an alternating
voltage, and since fre- I City
Tear off this
(Cont. on following page) Lp enny postcard.
.;ease say you saw it in RADIO & TELEVISION
tc
N,,
after Ifyou
career in Haan.
d Telvision."
matter
desire to BE YOUR
OWN BOSS in your
businessu or hold down a good
Job in Radio, i,
Pcrsonalizcd T ramming ill give you
the useful knowledge
edge
win success.
Practical
somewhat
critical and care should
be taken not to turn the
rheostat to its zero resistance position. If it is
expected to use the external battery quite frequently, it might he advisable to include as part
of the 45,000 ohm resistor
a 10,000 ohm variable
rheostat to serve as a
more effective zero adjuster for this high resistance range. Parenthetically, it might he
mentioned that the 45,000
ohm resistor consists of a
20,000 and a 25,000 ohm
resistors in series.
RADIO PARTS
Age
State
upon, mall in envelope
paste on
firemen -Cheek ehere O.
J
745
CISIN'S
H. G.
This Universal Test Meter
FAMOUS KITS
(Continued from preceding page)
1939 Senior Metal Tube
SPACE EXPLORER
All -Wave All Electric Beam Power
5 Tube Communications Receiver
G
OVER LAP
PINN-SKIP
meter..
Professional
Band Spread. Beam
Power,r.CommunieaSet.
SENSI.
POWERFUL.
SELECTIVE
Feaodeert,n
U ltra'
tures include: Beam
Power Output. BuiltEec
in
Patmitenedëisn A C.:
D.C.
Circuit. Low.
loss
Air Dielectric
-
t
Power Supply
hum. Full
Control. Headphone Jack. Dual Regeneration
Control. Beam Power tube furnishes over 2 watts undisgiving Full drillded apea
dynamic
t1
Volume1ONStudioo
Qualtity.glvSt
chassis. yowled foreign reception reported by many
Gives professionalr results. hut plans
rlearr anyone, even a novice. can build this set s ess
ful y
tt "g"
100% Metal Tubes rather than low-priced
engineered circuit as follows:
tam tubes in carefully metal
metal tube
tube 6C5.
tube 0J7,
etal tube 2526. one metal tube K -55 -A:
25Lmetal
6. °uone
e n grid pentode ágenerative detector, powerful
tuned
1st audio° amplifier. 2nd audio two -watt Beam Power
and automatic ballast stage.
Output. Half-wave
Kit
Senior Space
of all chassis parts. Power Supply andd
TT
m
clear. simplified wiring
wired, less tubes. coils and speaker)
Five Matured Metal Tubes $3.75: Four S.W. Coils
St,. to 200
ters 61: Two Wrest Coils 200 to 625
tern SI: Full toned
Si: Long Wave Coil 550 to 2000
all bands,
Band
PrreciisionreFiiltered
cab
and tested ív$225- Lexttra.wShipp
$1.50: Wired1.9d
Send
for Circular. 251'. deposit
weight
7 lbs.
C.O.D. orders.
SPECIAL- Sembled.St i`-led.Eé for T
with all coils Bi/ to 625 meters. set
metal tutus bout -In dynamic sneaker,
o
ed chassis.
matched
'.¡.f1
ready to
'39
JR. SPACE EXPLORER
RECEIVER
4 -TUBE
SANDS-
SEVEN
Junior
Proles.
Communications
Spread
Rand
sional
Set.
MODERN. SENSITIVE
AND SELECTIVE: Ample
Volume. Recepption from
as many as 30 foreign
'l
L
stations
evening
76.
`
in
by
tedn
y o
one 12A7
and
K- 105 -A;
.
anted
tuned
foal
po
uve deteerctor.
two-stage pentode audio
éerre-
automatic ballast stage.
amplifier, half-wave rectifier and
operates n 105.120 volts.
u
Self -contained power supply
D.C. Interchangeably. Built -in
frequency A.C.°
Chany
romatic Speaker. phone lack, antenna control. full
vision dial. band spread variable, dual regeneration á+asturdy
.
ring. Ideal for the beginner.
gralm simplifies
COMPLETE JUNIOR SPACE EXPLORER KIT
of
ils"lndasppeaker, '7
I (unwiréd. °lss tubes,
Coils
Four Matched Tubes $2.45. Four Short Wave meters
10 to 200 nt. Si. Two freest Coils 200 to 600
2000 meters Ill. Tru550
to
61. Long Wave Coil
TruFidelity
$1.45.
Speaker
Magnetic
Fidelity Chromatic
31.05. Attractive Two.
Chromatic P.M. Dynamic Speaker
Wired and factory tested $2n
toned Wood Cabinet $1.50.lbs.
No circulars available
ra. Shipping Weight 6
is model.
this
e495
i
SPE6IAL -e.un",Il,led. s"w'ir°ca.ExFártóri'-tésleTá lcña%sä+n;
tubps,all buÌlÌ,fn1 Trtu°F?éOOy"'Chroina+e oQ'f13.75
P.M.
H. G.
Dynamic
Speaker,
ready
.
to
CISIN'S All -Warr Air Scout Jr.
THREE -TUBE
20
$
WITH
PHONE
All Electric All Wave
Model 3AE Receiver
Les.
Tubes
rod
nouderful
all -wave set.
reception. Also
ssitive
A
werful foreign
records
e. `
° phone and broadspowerfuleus
1cast entertainment. Excellent
'
Works from any A.C.
ia st cor
DC house current.
to build.
tubes.
ballast tube as one of
n
attractive
mounts
Speaker
Panel. Range nt.'s to 610 meters
{ or
with
special
to 1500 meters
il. Complete Kit inloo wave
broadcast coll.
_._
7O
200 meter coll. Panel,
Variable
Chassis.
MODEL 3A -E
Pat. No. 2.086.256 Trimmer. IPoientiometer.
Dial.t Sockets, Knobs.
parts
her
ored
Resistors. Condensers- api all
With Phone (Las
Including instructions and dietubes. unwired)
ONLY
available: 90 to- 20
Following Auxiliary Parts are 45
il (foreign'
meter
coil (foreign) 25c; 15 to
Loud
5e: 40 to 80 meter coil (foreign) 25cí 5' Find -ait Screw
Kit 50e; Wood Wave
Antenna
peaker $1.25: Complete
Long
40c.
SA
each
-E
Kit loc. Tubes for Model
AtBandspread
81.30.
F.arphones
SI. Double
('nit and coil
model
tachment 75c.
ro extra foreign
NOTE: If you already have earphones.
3AE.
odel
coils may be substituted In
H. G. CISIN, CHIEF ENGINEER
ranf
.
-It
4b°dami
..
E= Measured
It
746
Park DPlaé
TRIPLETT ELECTRICAL INSTRUMENT CO.
1 -500 microampere 4" meter. type 421
fila., 5 ]lia., 10 nia.,
1 each following shunts
250 ma.
2 -50 ma. shunts
Full -wave meter rectifier, type C -4
-1
1P.
1
1
WATTS-
MALLORY & COMPANY
potentiometer, type CIMIP
-Pair
13124
jacks,
type No. 523
CUSTOM AUTO TRUNK CO.
1- Special
meter cabinet
MISCELLANEOUS
I -5" x 8%" hakelite panel
1-4.5 volt battery
(Engraving optional). Lines can be scratched in
Bakelite and filled with China white.
R=Line impedance
E'
Also
R.
-1000 ohm
1Special 2 -pale, 24 -point tap switch No.
type No. 10
1- S.P.S.T. jack switch.switch.
type 763
jack
-3 -pole,(12-throw
black and I red) insulated tip
1
E'
.006 R
voltage
A.c.
-
80,000, 400.000. 500.000 ohms
type WW 4
1 --1 meg., type M'M' -2
2 --1.5 meg.. type \VW -2
1 each -600 ohms. 8000 ohms, 20.000 ohms. 25.000
ohms, !$ watt. type IBT -%
:-
DB. -10 log
List
each- 20,000.
1
is not generally known
DECIBELS
that a decibel meter is merely an A.c. voltmeter. A chart has been prepared which
can he fastened inside the meter case cover
and which gives the number of decibels
corresponding to the A.C. voltage measured
across a 500 ohm line. For measurements
across any other impedance line use the
following formula
-
R
More About Frequency Modulation
(Continued !roui page 721)
Antenna and Ground
conditions, frequency modulation is the only
system which is worthy of consideration."
Since this receiver operates at a relaSome of the critics of the new Armstrong tively high radio frequency, it is very essenmodulation system have stated that ordinary tial to construct a good antenna and ground
transmission by amplitude modulation on system in order to obtain maximum results.
the ultra short waves is so static and noiseFor distances up to within thirty miles
free that it compares favorably with the from the transmitter, a simple horizontal
Armstrong method, but in a recent letter di-pole as shown in Fig. 1 should give
to the New York Times, Major Armstrong excellent results. It should be located free
challenges his critics to state (or to dem- from all obstructions and placed as high
onstrate) how they can produce the static from the earth as possible. Make sure it is
and noise -free transmission with their sys- run approximately at right -angles to the
tem comparable to that obtained by his fre- direction of the transmitter; i.e., if the
quency modulation method.
transmitter is located due west, run the
Through the courtesy of the General horizontal doublet in a north and south
Electric Company, we present herewith the direction. The horizontal flat top has an
wiring diagram and receiving antenna data effective antenna length of 10 feet 8 inches
on the new 12 -tube frequency modulation and consists of No. 12 or No. 14 bare
receiver.
copper wire (preferably stranded), cut in
(E.rperimenters might try connecting a the middle and the two halves insulated by
high frequency T.R.F. or other type K.F. glass insulators. A twisted lead-in wire is
receiving unit ahead of the second detector, then soldered to each side of the doublet as
instead of the superhet line -up shown in the shown, and the other two ends of the transstandard diagram, incorporating of course mission line are connected to the No. 1 and
the demodulator tube shoran in the present
No. 2 terminals on the receiver chassis. The
diagram. In any event, it is highly impor- lead -in transmission line may be of any
tant that the various stages be properly length up to 100 feet and should consist of
"lined up" with an oscillograph, if possible, low loss antenna lead -in wire. A good
as otherwise there is likely to be quite an
ground connection to a water pipe is conamount of distortion.Editor.)
nected to the terminal marked "G."
Somewhat better results may be obtained
The Model GM -125 receiver is a de luxe
instrument designed solely for the purpose by constructing the antenna shown in Fig.
of receiving and reproducing programs 2. This varies somewhat from the di -pole
transmitted by the frequency modulation antenna and is more efficient due to the
system. By special electrical and acoustic fact that the transmission line has very
treatment. this receiver will reproduce pro- little loss.
The antenna proper consists of a 10 foot
gram material with the exceptionally realistic fidelity that is characteristic of this 8 inch length of 1 inch diameter copper
pipe supported at the middle by a pole lomethod of transmission and reception.
d
Allied
Parts
INTERNATIONAL RESISTANCE CO.
95
dial.
B
quently the point at which this voltage is
measured also contains direct current, it is
necessary to use a .5 mf. condenser to block
out the D.C. component. The SI'ST jack
switch shorts out this condenser for all
measurements except for output measurements.
New York.
Tube
6SK7
6K8
Application
RF
Con,
Osc.
1st IF
2nd IF
6SK7
6SK7
6SK7
6SJ7
6Q7G
6J5G
(2) 6L6G
Plate to
Gold Colts
240
238
188
238
230
225
65
3rd IF
4th 1F
48
267
Inverter
51.14G
350/350
Line Voltage-120
S-54
Please say
yol+
sew it
iP
o
o
90
83
83
65
0
0
8.1
6.1
6.1
0
o
1.7
285
21
6.4
6.4
8.0
6.4
6.4
6.4
6.4
6.4
6.4
6.4
7.2
2.0
112
180
50
V. A.C.
RMS
N. Y.
90
90
2.9
Filament
Volts
Cathode
Cur. MA
7.5
65
1st Audio
Output
Rectifier
Tube Voltage Table
Cathode to
Syrern to
Gnd I'olts
G,d l'olts
RADIO
&
TELEVISION
No signal input
RADIO
&
TELEVISION
cated as high above the ground as possible.
The transmission line is made up of two
No. 12 or No. 14 copper wires, spaced about
2 inches apart and transposed every two
or three feet. The antenna end of the transmission line is soldered 131/4 inches each
side of the center of the copper pipe and
should form a triangle, 27 inches on all
sides. As in the previous installation, the
horizontal flat -top should run approximately
at right -angles to the direction of the trans mitter.
For greater distances, somewhat better
results may he obtained by using a reflector
in conjunction with the antenna described
and shown in Fig. 2. A suggested system is
to use a 1 -inch diameter copper pipe similar to the antenna, running parallel to the
regular antenna and located farthest from
the direction of the received signal. Fig. 3
shows a diagram looking from top and
dimensions should be followed very carefully. By experimenting, however, with the
distance between reflector and antenna, improvement in the individual installation may
iï!1;,:;t:_;>s:.::::.
THORDARSON
;P
GUIDES
:Tdó DARSON
The way to Easier, more
Efficient
Transmitter Construction
Amplifier Building
Radio Servicing
Thordarson engineers tell you how -simply, accurately.
You benefit by their constant and up- to-date laboratory
developments in these fields.
Transmitter Guide. No. 344-48 pages on transmitter design
and operation -from portable and beginners models up to
kilowatt rigs -fully described with circuit diagrams, parts
lists and photographs.
Sound Amplifier Guide, No. 346-32 pages of value to
every sound man. Circuits, constructional details and parts
lists for amplifiers up to 120 watts output.
Radio Service Guide, No. 342 -32 pages full of charts,
tables and shortcuts, which are always useful; together
with information on how to build a 32 volt power supply:
an improved condenser analyzer and impedance bridge.
COMPLETE MANUAL
All three guides, plus the Thordarson Replacement Transformer Encyclopedia, No. 243; complete catalogs; and
latest Thordarson bulletins are combined in an attractive
loose-leaf binder -the Thordarson Transformer Manual,
No. 340 -price 50c (postpaid).
be noted.
Note -The reflector is a floating copper
bar and there are no external connections.
Connect and install the regular antenna as
shown in Fig. 2.
Operation
The receiver has three operating controls,
as follows
Volume Control and Power Switch.
The control marked volume (left -hand
control) also actuates the power switch for
the receiver. When the control is in the
extreme counterclockwise position, the receiver power is off. From this position,
slight rotation in the clockwise direction
will turn the receiver on and the volume
will be at a minimum setting. Further clockwise rotation will increase volume until full
output is attained.
:
Tone Control
This control (right -hand control) is continuously variable from bass to full -range
to treble. The proper setting depends largely
upon the tone most pleasing to the listener
and upon the type of program being received.
Tuning Control
The tuning control is the large drum
located above the volume and tone control
knobs. To tune the receiver merely rotate
the drum dial ith the thumb. The scale
is calibrated in megacycles so as to approximately locate the desired station.
When a station is located, a final adjustment is made by leaving the drum dial set
at the point of minimum noise background.
This point of exact tune is very important
as it is only when the receiver is tuned to
the position that the full, rich tones are
available.
Circuit Alignment
I.F. Amplifier
Due to the good stability of components
and the wide band characteristics of this
amplifier, alignment should be unnecessary
under normal operating conditions. Should
it become imperative that an LF. alignment
is desirable, it will be necessary to use a
cathode ray oscilloscope in conjunction with
a 3.0 megacycle signal generator with a
superimposed ± 300 kc. sweep frequency.
This generator may be built up by constructing an oscillator with the tank condenser semi -fixed and variable, the variable
portion being designed to be rotated by a
motor and of proper capacity to give ± 300
kc. variation of the 3.0 megacycle slid -frequency. Connect the vertical plates of the
oscilloscope across the resistor R -15 of the
4th I.F. stage and align transformers T -7,
T -6, T -5 and T -4 in a progressive step by
step method.
for April, 1939
-
Get your copies today
from your distributor or
from factory postpaid
at prices indicated. Address Dept. RT. 94.
THORDARSON ELECTRIC MFG. CO.
50o W. HURON ST., CHICAGO, ILL.
Frequency Demodulator
With the saute oscillator and sweep signal as used above, connect the vertical
oscilloscope plates across the resistors, R -18
and R -19, then align the transformer T -8
for a cross -over curve as shown in Fig. 4.
Proper alignment of trimmer C -51 is indicated when the curve crosses about midway in a vertical plane. Proper alignment
of C -50 is indicated when the sides of the
curve near cross -over are nearest to a
straight line.
Note -Keep signal input high enough so
that noise limiter is functioning. This point
is indicated when an increase in signal input
no longer changes the size of the curve.
Alignment
R.F.
Make sure the last division on the low
frequency end of the drum dial coincides
with the escutcheon mark when the gang
condenser is completely closed ; then, proceed as follows:
1. Connect a high resistance 0 -10 V. D.C.
voltmeter across R -15.
2. Apply a 42.8 megacycle unmodulated
signal to the antenna terminal board.
3. Set dial scale so it is tuned to 42.8
megacycle and peak oscillator trimmer C -4
for maximum voltage reading on the meter.
4. Peak the antenna (C -2) and R.F.
(C -3) trimmers for maximum voltage output on meter.
Electrical Specifications
volts
115 -125
Frequency
Watts Consumption
E_
/i
_.
e
..__
J
.
proud to announce what we
believe to be the first 100% com-
WE are
munication receiver kit. Designed
by McMurdo Silver, it incorporates and
goes beyond the design principles laid
down by the A.R.R.L. Handbook, QST
and practically every technical mega.
zine.
Fully assembled and with complete detailed instructions, it can be wired and
tested by even the novice to produce
the maximum of results for the very
minimum of cost.
it at your jobbers .
or write
Dept. RT I for full details of this
other
.. items.
See
and many
50/60 Cycles
160
Tuning Frequency Range
37 -44 nie.
8.1.6.81 meter,
Intermediate Frequency
Mid- frequency
3.0 M.C.
Band Width
300 K.C.
Electrical Power Output
Undistorted
12.0 Watts
Maximum
15.0 Watts
Please say you saw
i SIlVER
S¡/PER
it
in
RADIO
&
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www.americanradiohistory.com
EDWIN
I.
C
400
S
PEORIA
cuu
Si.
CHICAGO.
CD..INC
U.S.A.
osmaso
747
The Radio Beginner
RADIO INSTRUCTION
(Continued from page 724)
radio sets employing it are known as T.R.F.
receivers. The action of such an amplifier is
the sanie as the one already described. Plate
current, flowing through the primary of
the transformer, by magnetic action causes
an alternating voltage to be placed on the
grid of the following tube. In this instance,
however, the secondary is tuned to resonance at the frequency desired by means of
the variable condenser connected across it.
Sometimes the primary is also tuned in this
fashion. It should be observed in Figure 2
that use was made of screen grid tubes,
in this way avoiding feedback through tube
capacities, a situation difficult to overcome
with the triodes shown in Figure 1, except
through the use of an external neutralising
device.
In receivers employing R.F. amplification,
the T.R.F. (tuned radio frequency) amplifier has found the widest application, but
it should not be thought that the circuits
described so far are the only ones in use.
YOU CAN BECOME
A CODE
EXPERT!
Quick
Candler Way!
Learn the
Candler doesn't care if
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he has taught thousands upon thousands
of others, including such operators as
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after you've started Candler
lind yourself reading code a.
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strain or conscious effort. A few weeks of Candle)
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Learn how the Candler system works. read what
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In
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you'll
Tuned Impedance R.F. Coupling
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British Address: Rm. 56. Craven House
Kingsway, London. W.C.2
YOUR FUTURE IN
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mm
$2.25aeach
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month more.
oper month exttra,
head phones
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111.
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RADIO
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500 LICENSED graduates placed in past 7 years
in shipping, broadcasting, aviation, police. etc.;
we also teach radio servicing and repairing: new
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MASS. RADIO SCHOOL
18
BOYLSTON ST., BOSTON
Est. 1899
RADIO
ENGINEERING,
broadcasting, aviation and police radio, servicing, marine
radio telegraphy and telephony. Morse telegraphy and
railway accounting taught thoroughly. 48 weeks' Engineering course equivalent to 3 years of college radio work.
All expenses tow. Catalog free. School established 1874.
Dodge's Institute, Turner St., Valparaiso, Ind.
748
Another type of amplifier is known as
the resistance coupled R.F. amplifier, and is
shown in Figure 4. This circuit is now seldom used for amplification before the detector stage, but has found wide use as an
audio frequency amplifier and will be described in a future article on audio amplifiers.
Band Pass Filters
Sometimes certain undesirable effects
known as cross-modulation and second harmonic generation are present in receivers.
In order to avoid this effect, a band pass
filter or band selector is used, as shown in
Figure 5. The purpose of such a filter is
simply to present a high impedance or resistance to all unwanted frequencies and at
the same time allow the reception of those
frequencies it is desired to receive. Since
the band -pass filter couples the antenna to
the grid of the first tube through a number
of tuned circuits, a sufficiently high order
of selectivity is obtained so that a strong
signal, after passing through the filter, will
not be strong enough to cause the R.F. tube
to act as a detector.
Please
say you saw
it in RADIO
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Insure your future!
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Resistance Coupling
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RP esentatiivesd foreplace.
Radio College of Canada. 863 Bay
In the tuned ionpedante coupled R.F. amplifier, shown in Figure 3, we obtain a
voltage drop across an impedance and apply
the changes in voltage across this impedance to the grid of the next tube through
a fixed condenser. The coupling device consists of a coil and condenser placed in
parallel (or shunt) and inserted between
the plate of the tube and the source of
voltage; that is, in the plate circuit. In
rotating the variable condenser, the coil condenser combination is tuned to resonance with the frequency to be received, and
in so doing offers the greatest possible impedance to that frequency. The plate current meeting this maximum impedance produces the highest possible voltage drop
across the coil- condenser combination. The
voltage changes are applied to the grid of
the following tube by means of the fixed
condenser connected to the impedance. The
size of the coil and the capacity of the
variable condenser are so chosen that they
tune over the desired bands of frequencies.
In a circuit of this type, difficulty is often
experienced with feedback, since it cannot
be controlled by neutralization. Resistors to
control oscillation are placed in the positive voltage lead. Generally speaking, such
R.F. amplifiers are seldom multiple staged,
RADIO INSTRUCTION
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Also specialized courses and Home Study
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AMERICAN RADIO INSTITUTE
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NEW YORK.
RADIO
&
N. Y.
TELEVISION
New Type Communications Receiver
(Continued from page 742)
receivers. vet recommended in every re- to the receiver. At the center is the 73C
ceiver described in the A.R.R.L. Handbook. dial, accurately calibrated for six waveOriginally advocated, it is 'believed. by the bands from 540 to 61,000 kc., inclusive. It
writer in 1932 -33 as the easiest means in can be turned fast by its center knob, or at
an I.F. amplifier of obtaining single-signal 15 to 1 reduction by the knob at its lower
selectivity, its inclusion in first detector right. The outer edge of this dial carries
circuit also gives the high R.F. gain before 500 vernier divisions with 0 -10 decimal infrequency conversion, so essential to good dicator. Where greater band -spread is designal-to -noise ratio, as well as tremendous- sired a simple 12:1 gear train can be slipped
ly increasing effective image frequency
over the condenser shaft behind the panel,
selectivity. In this particular design the I.F. and projecting through a panel hole beneath
regeneration knob is no more critical than the right center of the plain dial, carries an
ally variable selectivity control-actually 0 -200 degree, 4" band- spread dial which
simpler to operate than usual crystal filter then "peeks out" at the upper right of the
controls -while R.F. regeneration, once set, main dial to be read against a second decineed never be touched again. Thus no mal vernier indicator to give eleven feet of
criticism of possible complexity of opera- dial length per hand with a readability of
tion in the bands of amateur or short -wave one part in 21,600.
Dx -er is justified, while the gain from the
intelligent use of regeneration is amazing.
Band -Switch
One particular advantage is the eliminaAt the lower left of the dial is the wave tion of tubes which regeneration makes change knob operating four separate
possible. This reduces cost and power (train, switches insulated with the new "X2B" bebut even more important, cuts circuit noise neath the chassis. These have double- spaced
to a surprisingly low minimum. Actually contacts spread over a full 360 degrees to
in the "Silver Super" inherent noise is only give short connecting lead lengths and the
2 milliwatts at
microvolt absolute sensi- lowest possible inter -circuit capacity. R.F.
tivity. In his experience of designing hun- and oscillator circuits are simultaneously
DIO
TRAINING
T
G E T
;OR
r!
1
Fig.
4.
Sub- chassis
view. The coil and
switch unit is factory -
Complete in 1 Big Book
Just think Packed into this
large x
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You can start learning at once, for Ghirardi's
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dreds of receivers over nearly three decades,
the writer has never before been able to
attain such a quiet yet super- sensitive
circuit.
Noise
Limiter Included
Following closely the Irnv cost single signal super -het described in the October,
1938, and February, 1939, QSTs this new
set uses one 6K8 regenerative first detector oscillator, one 7A7 "Loctal" regenerative
1.F. amplifier, 7A7 audio beat oscillator, 6118
second detector, A.v.c. first audio amplifier
and new type noise limiter, 6 \'6 beam power
output tube, 80 rectifier, and one \íR150
automatic voltage regulator tube. Including
A.c. power supply, it mounts on a chassis
1/16" thick for absolute mechanical rigidity.
This pan is Only 15)Q" lung. 7" deep and
3 Va" liigll, with control panel 17" by 9/"
A steel cabinet with hinged lid and removable hack is available, 9;;" high. 177/a" long
and 12" deep -with plenty of room behind
the chassis to carry a 6 -volt battery power
supply or dry ":\" and "B" batteries for
portable operation, or the improved forni (if
the Diversity Coupler recently descrihcd
in RADIO & TELEVISION which turns the
"Silver Super" into a full -fledged dual
diversity receiver to minimize fading and
its accompanying noise. The simplicity of
parts layout. resulting in the extremely
short and direct leads so essential to maximum efficiency, are clearly illustrated in
Figs. 2 and 3.
Fig.
shows all of the controls essential
1
for April, 1939
switched, with all unused coils short -circuited to prevent dead-end or absorption
losses, which can become very serious at
short wavelengths. All coils, including the
extreme high frequency coil, are mounted
on the wave -change switches themselves, as
arc the oscillator high -frequency padding
ci,n(lensers which set dial calibration. These
padding condensers are compression mica
un ceramic bases, not air -trimmers. Through
special secret processes, these particular
condensers (Guthman No. C45) are actually as stable as good air -dielectric condensers, and of very low loss design. R.F.
coil sizes are such as to produce optimum
Q versus shield proximity.
At the tipper left of the panel is the calibrated S- meter, with below it the noise
limiter knrih, the extreme upper right knob
being the beat oscillator pitch control.
\long the bottom, left to right, are tone
control. ht all -phone jack, antenna trimmer,
ben oscillator on -off switch, wave change
switch, vernier tuning, send -receive switch,
audio volume control, A.V.C. on -off switch
and I.F. selectivity control. Attention is
called to the antenna trimmer knob; manual
control of circuit tracking is provided in
order to insure the very best possible results,
and to take no chances of differences in antennae or adjustments of first detector regeneration upsetting circuit tracking, in
line with recent trends in this direction in
the newer communication receivers.
Fig. 3 shows a 6K8 tube used as detector -
Electra.
Reds
B a
the
training
that
>
not
Radio. but alw
about
Electricity,
Sound,
Cathode -Ray Tubes, und Television
cell- Ìt 's the
Sound. s
Electron
eta., .t l.,
:
.
,
self.
-nt
i
SO
;
Marne
.. TransInformers
Conductance
densers
Cur-
Onee you
.
rent Circuits
antl. No
I
I
the
1ng Foult
a r ,i
Audio
is
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o, her
any
until.
USE IT
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OUR RISK!
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,,,,
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is
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reading I:hlrtraining Is
elr.ta l- clear. That's shy
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hl de-
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al
1 revolons
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.n
s knack for M aking un-
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Filters
Tcasurng
Instruments
Radio war..:
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Broadcast
linos
and
ITS
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AMAZING!
Sou
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TEAR
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OUT-MAIL NOW!
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ri.
TLIevi-,.
RADIO & TECHNICAL
PUBLISHING CO., Dept. R&T -49
as Astor Piace. New York
'. nere is S.t iSi rio foreign) for in
of RADIO PHYSICS rot MSI
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(Continued on folloudny page)
Please say you saw it
in
RADIO
&
TELEVISION
749
New Type Communications
Your Inquiries Invited
(Conlinucd from preceding page)
oscillator. Numerous tests of many different
combinations of different tubes, single and
separate, showed the 6K8 to be definitely
the best converter available today in terms
of stable oscillator output right down to 5
meters, maximum conversion gain, and freedom for interaction between first detector
and oscillator circuits. Regeneration is independent of wavelength, and permanently
set upon installing the receiver, is adjusted
by the potentiometer connected to the feedback condenser Cl. Stable and permanent
regeneration is secured in a manner new
to receivers. An R.F. choke, R.F.C., in the
plate return lead provides R.F. voltage which
is fed back from the arm of a potentiometer
across R.F.c. to the grid circuit A.v.c. return
through Cl. At first this may look inoperative, but consideration of the capacity
ratios of Cl and C2 should make it clear
that regenerative feed -back does occur.
Tuning condenser capacity is 140 mmf.amply low for maximum gain, and far lower
than is found in most all -wave or even
communication receivers. C3 is the antenna
trimmer, adjustable from the front panel.
High impedance antenna primaries prevent
differences in antennae upsetting regeneration or circuit tracking, but no chance is
taken with hard-to -get signals and C3 is
made manually variable. It is not critical
and can be forgotten except when the weakest of signals must be pulled through.
Compare My Terms with Others
Model and
Receiver
12Monthly
Down
Cash
Payment Payments
Price
115.50
23.10
LIS
RME-70
$138.60
HQ -120X & NCI01X 129.00
$27.72
25.80
$9.79
120.00
24.00
NCBIX 99.00
Grating 49 and SI6 99.00
Howard 438
49.95
NC-44 and S-20
49.50
Sky Buddy
29.50
19.80
8.48
6.99
19.80
6.99
9.99
3.53
9.90
3.49
Skyridar SX -23
NCIO0A
NC8OX
and
9.11
2.08
5.90
Also HRO. Breting 9. Howard,. Sargenta.
all others
Similar terms on Hallicrafters, National,
Harvey, RCA, RME, Temco transmitters and
Thordarson, National, U.T.C., Utah, Kits.
All orders and inquiries attended to by Bob
Henry, W9ARA; active amateur for 14 years;
h
graduate M.I.T.E.E.; owner of Henry Radio
Shop selling amateur supplies for ten years.
N'11:AR:A
MISSOURI
MIDWEST FAncter SALE!
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to easy
put this big
new 14 -tube worldwide Midwest chassis in
your cabinet and get
CHASSIS
IN YOUR CABINET
exciting world -wide recep-
tion. Midwest
makes a radio
to suit every
purse...6-tube
to 17-tube, 5band models.
Prices start
._COMPLETE
WITH TUBES AND SPEAKER
os
low
as
$
1
0
.
5.
9
An Much A+
TRADE - IN ALLOWANCE
. on the beautiful 17 -tube, 5 -band
Model D" shown on left.
Money - back guarantee. Write
for new FREE 1939 catalog.
$40
MIDWEST RADIO CORP., Dept. 14-LL, Cincinnati, O.
Do you need
BINDING POSTS?
XL
Arion
PUSH
POST
..;ira
um.tant
N iprIng
Coonuct
1
MaeS
nufactured t' in All Aluminum Type
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lurni
Al
umc Body, Bakelite
Top Type
insulated with
I
M
et
?Yp Insulating Shell
CI at 20eBeach
:old proven by 240 hr Salt Spray Test
AS NON CORROSIVE our Types CP or
NP at 28e each.
Manufacturers and Dealers liberal
Discounts
X. L. RADIO LABORATORIES
420
750
West
Chicago
Ave..
Chicago.
Ill.
The I.F. amplifier uses two permeability tuned high -Q 1.F. transformers. These are
the most stable types known today, for
their tuning capacities can not vary, being
"Silvercons," in which silver is directly
plated onto mica, so that capacity cannot
change. They are really fired condensers.
Tuning is effected by micrometric adjustment of powdered R.F. iron cores inside each
1.F. coil. These two transformers represent
much research and experiment to allow
them to be regenerated without any frequency shift. Ordinary 455 kc. transformers
used in a regenerative 1.F. amplifier will
show up to 10 kc. frequency shift for different degrees of regeneration, and this is,
of course, highly undesirable. if not intolerable. Careful adjustment of coupling and
stray capacities results in the "Silver
Super" showing no measureable frequency
shift at any degree of regeneration. The
I.F. tube is the new 7A7, all -glass "Loctal"
Type. In this new tube, element leads enter
a flat base or stem, instead of running up
through the usual 1%" long stem tube and
so providing harmful capacity and inductance. Having no molded bakelite base, but
rather contact pins set directly in the glass
itself, base losses are a thing of the past.
A small metal socket aligning -cap shields
the base so that both grid and plate leads
come out the same end-the new "single ended" type of R.F. pentode construction.
Gaits is higher than for the older 6K7, for
the "Loctal" idea makes real sense in tube
design. A second 7A7 is the beat oscillator,
coupled to the second detector by capacity
provided through judicious parts placement.
and tuned from the front panel by a knob
controlling its powdered iron core so as
to permit optimum choice of beat note for
single - signal selectivity, zero beating for
broadcast reception, or different beat note
pitches to reduce heterodyne interference
-which is noticeably absent due to the
extreme selectivity possible. J.F. regeneration
selectivity and gain control is
through cathode bias with feed-back
-
Please say you saw
-
it
in
RADIO
Featu rest Nickel Silver framed Indicator with Integral
friction springs. Scales calibrated directly on wellseasoned
Retains
regardless of trn.
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Instructions and Illustrations Of primary operations
clearly printed on
er
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teachingatàcbn,le
e
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pocket
&
TELEVISION
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offer an eight inch. hits ood, accurate
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two36 -page Rook of 300 Examples and Answers.
toned Facalmlie of the Declaration of Independence,..
suitable for framing. and an S -page catalog illustrating
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Prices o n binders. P.P.
prepaid.
.............$1.00
STOPPANI
COMPASS
A
Precision Instrument
made in Belgium. Purchased by the U. S.
Government at more
than $30.00 each.
Ideal for Radio F:x-
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al
a
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BUTLER,
The
PRACTICAL, EDUCATIONAL, TIME SAVER
Receiver
When you reed amateur equipment it
is to your advantage to write to me.
You get personal attention; 6% terms
financed by myself so you buy with less
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100% satisfied. For any equipment, the
latest information and technical help,
write to W9ARA.
A PROFESSIONAL SLIDE RULE
for tfo
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Our price prepaid $4.50
i
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Send for catalog containing full descriptions of these
and many other interesting items.
GOLD SHIELD PRODUCTS
---- M
Dept. RT -4 -9
New York
350 Greenwich St.
EE!
Our new Catalog describing over
thirty -two books in the "How to
Make More Money" field has just
come off the press. This catalog describes each book in detail. It enables you to select one or more
books which will meet your requirements in an attempt to improve
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Many of the books in the NATIONAL PLANS INSTITUTE catalog tell
you how to start a spare- or full time business of your own.
Write today for your FREE copy
of the "NPI" Book Catalog -address a one-cent postcard to Dept.
RT439 -and mail it today.
NATIONAL PLANS INSTITUTE
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--- - - - - -J
246-T FIFTH AVENUE, NEW YORK, N. Y.
...
RADIO
&
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through slightly augmented grid -plate
capacity of the 7A7 I.F. amplifier.
A.V.C. Switch Provided
The diode second detector and A.V.C. of
the 6B8 is essentially conventional with optimum values chosen and the switch provided
to cut out A.V.C. without affecting detector
action when desired, as for code reception.
A 7A7 is used as a V.T. voltmeter, feci
from the diode load, for super -sensitive tuning meter operation. The pentode of the
6B8 is used for first audio stage -not so
much for its high gain as to provide the
simplest possible noise limiter. Varying the
screen voltage on a pentode controls its
plate current-in effect, controls its "saturation" or the strength of the signal it
can handle. This characteristic allows noise
louder than signal to be held clown to no
louder than signal by variation of screen
voltage. This can be done automatically,
which does not give most satisfactory results in operation, for then the system becomes a true "hole- puncher" silencing reception when noise appears. So operated,
such automatic silencer is so effective that
loud noise will actually shut off reception
during its duration. A manual control is
obviously more desirable, and so is provided. By permitting noise to be held down
to signal volume, it gives the impression
of having almost completely eliminated
noise, so great is its seeming reduction.
This noise limiter is equally effective on
all types of noise, at all wavelengths.
Audio gain control is in the 6B8 grid circuit, with tone control and head -phone jack
in its plate circuit, which is followed by a
6V6 beam power output tube for loudspeaker operation -and this set will "rattle
the speaker" on almost any signal that can
he heard. Power supply is essentially conventional, with chassis -mounted power
transformer of ample size for good heat
radiation, large, very high effective inductance filter choke and plenty of sealed -inmetal -can dry electrolytic capacity of generous voltage rating for extreme safety.
Sockets are provided for the VR150 automatic voltage regulator tube for the user
who desires the frequency stability usually
associated only with a tine frequency meter,
but seldom with receivers. This tube is not
essential, but is a distinctly worthwhile refinement.
"Send-Receive" Switch
In line with attaining extreme stability,
the send -receive switch is used in a new
way. Instead of breaking only one or two
plate circuits to mute the receiver during
transmission, the S -R switch cuts the entire "B" supply to all tubes, including
power to the filter. Thus, the operator, desiring a taste of real receiver frequency
stability for a change, may leave the onoff switch on all the time -or turn it on
in the morning before an evening of opera tion-so that tubes and set will have reached
stable temperature by evening and there
just won't be any frequency drift.
Still another refinement is the eight prong socket and dummy plug just before
the filter. fulling the plug opens the filament and B- supply circuits so that with a
live plug another source of power -dry
batteries. dvnamotor or vibrator "if' and
battery "A" can be connected to the set.
It is thus substantially independent of
power sources, and can be operated A.C.
or battery.
For the amateur who cannot afford to
immediately buy all parts for the receiver
as described, a distinct convenience exists
in that he can buy parts for everything except the power supply, 6V6 power output
for April, 1939
Complete RADIO TRAINING
for
$
95
Regular $39.00 RADIO TECHNICAL INSTITUTE Course
AN UNUSUAL OFFER
limited quantity of
R.T.I. $39.00 radio servicing courses have been reprinted and are offered to
you at only $1.95. These
are the latest 1937
courses, complete in every
detail with all supplementary material. and exactly
t he same as
the originals.
Radio is the present -day opportunity
field. Hundreds of men with no special
talents have studied Radio Servicing for a
short time and are now making twice and
three times as much money. R.T.I. unique
radio training brings rich rewards ; you can
get ready quickly. inexpensively, easily. and
in your spare time for a good job in radio.
A
It.T.I.
THREE COURSES IN ONE
course is really three complete essential r
mbined. You get training in
u nd
Applied Radio; III Fundamentals11)of Practical
Radio Fria
tildes; and 131 Advanced Specialized Training.
Thi,
Is the raining that
ill place .run above the average
radio servicemen -.and you get
this training for
0015 31.
There are over 32.000.000
dlo sets in use. Over
4,5011.000 auto radios alone. You should
cash in on
a
this gigantic money market. The R.T.I. easy practical course will pave Ue a to your ital.-in., in
Radio work.
training Is complete. Everything
simple
farts to complex alignment problems. Manyfrom
servicemen
have found that R.T.I. training Is excellent for brush
up and study of modern servicing methods. This is
the best buy in a radio education. Take
advantage of the bargain price today.
The
LATEST DATA
ACCEPTED BY INDUSTRY
Forty large radio manufacturers have helped to prepare the R.T.I. course. Just think what this barking
by the radio Imlustry means to you. KT.!. practical
training will give you facts and real data you will
Hundreds of diagrams and illustrayou. You will pass quickly from
lesson to lesson and In a surprisingly short time
will be ready to do real radio servicing.
.
will help
COMPLETE IN ALL DETAILS
No Special previous education or experience is needed.
It.T.I. course will give you all the training you need.
The lessons are clear, interesting, easy to master and
use. Fellows who knew nothing about radio before
taking the A.T.I. course are now the leading servicemen In their communities. This is your chance to
obtain thus excellent course for only $1.95.
From the very start you are introduced to practical
servicing equipment and practices. You are told hen,
to open your own shop or radio store. Lesson I.
"The Radio Servicing Business," will give you n
practical ideas and hints. The course is so planned
that you will he able to earn spare -time money before
>ou have reached your tenth lesson. The special $1.95
price of the complete course can bo earned in
single evening's work.
YOUR GUARANTEE
You are completely
protected. We
guarantee
these
to be exactly as the original $39.00 Radio
Technical Institute courses. Money back guarantee.
courses
References: Liberty National Rank, Chicago.
Yes. In the R.T.I. course you will find
complete explanation of A.V.C., how
to use an oscilloscope. sound feed -back,
resonance phenomenon
every possible fart you must know to be the best
servicemen. You get a real radio training.
One of the REST radio courses is yours
for only $1.95.
a
need on the lob.
tions
-
TELLS HOW TO USE INSTRUMENTS
Iu
LIMITED QUANTITY
Hurry your order to us today. There is but a small
quantity of the courses left at the special price. You
are completely protected with our guarantee. Send
total remittance with order. or we will ship C.O.D.
Postal money orders. checks, currency. unused stamps
accepted. Answer today.
SUPREME PUBLICATIONS, Agents
3729 W. 13th Street, Chicago, Ill.
Please send the complete R.T.I. radio course at
the special $1.95 price.
O I am enclosing $1.95, send prepaid.
C Send C.O.D. I will pay mailman $1.95, plus a
rew cents Postage.
NAME
ADDRESS
stage, beat oscillator, tuning meter and
voltage regulator tubes. He can then assemble a 3 -tube set -regenerative detector
oscillator, regenerative I.F. amplifier, second
detector, A.v.c., audio amplifier and noise
limiter that on headphones, with batteries
or "junk -box" power unit, will give performance which will amaze the hard -boiled
operator who sniffs at any communication
receiver costing less than $200.00. The user
can then add on as he can afford to, until
in the full -sized eight tube set he has something that has banished his receiver worries
for a long time to come.
The writer will gladly answer questions,
or give complete parts list and full "how to-build -it" details to any who may care
to write to him in care of this magazine.
Photos and description courtesy of Edwin
I. Guthman & Co., Inc.
-
A
Letter from London
nlimte d from page i l8)
to a letter from the editorial department
of the British Broadcasting Corporation,
asking further information, J. R. T. Hopper
writes "We would like to make it clear
that the cable has been installed by the
Post Office primarily for multi-telephone
work, and that the suggestion that it may
be used for television has been purely incidental.As a matter of fact, decision on the
possibilities and method of extending television beyond the London area lies with the
Television Advisory Committee, and so
far no official announcement has been
made."
:
that MUST
AST!...
Performance far beyond normal expectation
accounts for the growing popularity of AEROVOX
condensers and resistors. Likewise AEROVOX
predominance in most assembly specifications. So
be guided accordingly if you seek the LONGEST
service at the LOWEST cost.
DATA
it
in
RADIO
&
TELEVISION
www.americanradiohistory.com
catalog
available
at
_
CORPORATION
NEW BEDFORD, MASS.
IN CANADA
Please sty you saw
Latest
local AEROVOX supplier. or
from us direct. Ask for details regarding our
monthly RESEARCH
WORKER publication.
AEIOVOX CANADA LAWN.'
Haaiea.
ono
751
Antennas -Past, Present
Astonish
and Future
YOUR FRIENDS!
(Continued Iron/ pays- 709)
500,000 Vts.
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TESLA -OUDIN HI -FREQ. COILS
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Solenoid & Magnet Data -Get Our List]
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The DATAPRINT Co.
RAMSEY, N. I.
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PLUG -IN COIL FORMS
Especially Recommended
For All Home-Constructed Receivers And Low Power Transmitters.
from natural
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eight -rib f o r m s are
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note that there are as many cycles between
5 meters (GO megacycles) and 10 meters
(30 megacycles) as there are in the entire
radio spectrum above 10 meters. The services that will undoubtedly develop in the
ultra -short wave spectrum may eventually
become as important, or even more important, than the services now existing in
all of the rest of the radio spectrum. For
example, the ultra-short wave band is the
only part of the spectrum suitable for high
definition television. Bands of 6 megacycles
width in this spectrum have already been
ear-marked by the Federal Communications Commission for experimental television transmission.
We have seen that in the transition from
the long waves to short waves, there was a
radical change in the type of antennas that
were found useful a »d necessary for the
new services. Will the development of the
ultra -short wave spectrum see a radical
change in antenna structures such as we
do not dream of today?
In the long distance use of short waves, a
limit was found in the concentration of the
radio beam that could be used successfully.
To obtain a high power gain. it was necessary to concentrate the radiation into a
narrow beam in the vertical plane as well
as the horizontal plane. It was found that
there is no single vertical angle at which
the radiation can be launched that will be
effective over a considerable period of time.
The classic work of the Bell Laboratories
in the development of the MUSA system
indicates very clearly that the signals
may travel over several bundles of rays,
but that these paths are quite variable and
require a wide range of vertical angles to
obtain reliable communication over a considerable period of time. This phenomenon
sets a limit on the usable concentration of the radiated or received radio
energy. As a practical matter, an antenna
with a concentration which produces a
power gain of 100 is probably close to the
useful limit. Will a similar limitation in
the concentration of power he found on the
ultra -short waves? No such limitation is
known today, and as the wavelength becomes shorter it is practicable to build antennas that will highly concentrate the
radio beam. Will we see strange contraptions with power gains of 1000 or more
on relay chains carrying television network programs and multiplexed mass
communication ? If power gains of a high
order can be used, the transmitter power
required will decrease in proportion so we
may see a miniature "acorn" tube transmitter associated with an enormous directive antenna structure. The possibilities of
using radio repeaters even smaller than
telephone type repeaters, and concentrations of energy that reduce the attenuation
over a given path to a very low value are
indeed intriguing to the imagination.
Another factor that will affect the antenna design for the ultra-short waves is
the necessity for providing antennas covering an extremely wide band for high
definition television. We have already seen
some radical departures from familiar
forms of antennas in this field in the television antenna recently erected on the
Empire State Building in New York. Here
we see radiator elements looking like Indian clubs projecting from an expanding
throat, appearing somewhat like the streamPlease say you saw it
in
RADIO
&
TELEVISION
ELECTRON
a
INC
OvTf7T
Now
YouCan ELECTROPLATE
Easily with a BRUSH!
new for amateurs, fans, set buildSOMETHING
ers-something which gives you the opportunity with which to experiment. Here's an
ELECTROPLATING KIT amazingly simple to
operate -you just Electroplate with a Brach! Re-
quires only one single dry cell.
NOT A
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equipment to you for plating articles in hotels, apartments. office buildings. medical and dental offices. far tories. schools. laboratories. etc. Exactly the same outfit
(hut larger) is used professionally by electricians, radio
service men, automobile repair shops. etc. And for radio
work. you can electroplate tarnished receiver parts, chassis.
contacts. own radio parts and accessories.
Pm this REAL ELECTROPLATING KIT to use immediately-make It the most useful article In your lab
or work bench. And, you can get it absolutely FRED
)except for slight mailing coat).
You can electroplate for profit,
household- ashtrays. fixtures.
Rend your subscription today to RADIO AND
TELEVI-
SION for One Year (12 issues) and receive absolutely FREI: one of these REAL ELECTROPLATING KITS
-New aubsrrlhers are accepted or you may extend your
present subscription another twelve months n ter this
offer. Mail your remittance of $2.50 (Plus 10e for shipAND
the publishers
ping charges
(Canada and
$2.85. f You
promptly receive your FREE REAL ELECTROPLATING
below
to
order
the
coupon
return
mail.
Use
OUTFIT by
Your subscription.
99 Hudson
RADIO AND TELEVISION
New York, N.Y
Street
RADIO AND TELEVISION
HUDSON STREET, NEW YORK. N. Y.
Gentlemen: Enclosed ynu will find my remittance of $2.50
AND TELEfor which enter my .subscription to RADIO promptly
my
VISION for One year 12 Issues,. Send me
OUTFIT. (Canada and
FREE REAL ELECTROPLATING
foreign a2.8n5.1 In U.S. add 10e additional to cover
99
shinning
(
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(
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NEW SUBSCRIBER
EXTEND PRESENT SUBSCRIPTION
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Address
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(Send
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sumps.)
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rash
or
RT -a -39
RADIO
&
TELEVISION
lined Nacelle of a modern air liner. By this
unusual design, a radiator is obtained
which, electrically, looks like a resistance
over the complete octave of frequencies
from 30 to 60 megacycles, many times
wider than any omni- directional (all directional) antenna known to the prior
art. In other words, this antenna has a flat
characteristic over a range 30 times as
wide as the normal broadcasting band.
As we learn how to use shorter and
shorter wavelengths we may well expect to
see increasingly radical antenna designs
which have little resemblance to the antennas that have been familiar to us in
the long wave and short wave fields.
MARINE and COMMERCIAL -TYPE RECEIVERS
-
MODEL
13 Tube Performance
(10
ed)
(Continued from page 710)
looking at a miniature house. And what a
house! -the shingles were even cut on a
taper, and every detail of the full -sized
door, even down to the doctor's nameplate,
was accurately reproduced in the miniature.
The chimney of this model house was constructed of lumps of sugar suitably painted
with water colors.
In one of the interesting scenes, an
animated spider's web was desired, and
here the spiders -which were made in the
studio specially for the purpose -were
caused to move by a series of small rods
rotating inside hollow tubes forming part
of the web. These rods were geared together by means of a chain and driven by
a motor.
Some of the books used in the television
scenes are made of plaster of I'arts, suitably
painted to resemble actual books.
The writer was quite astonished to learn
at what speed some of these objects were
constructed and painted. Warships in
miniature are made in a jiffy, as also are
models of certain animals desired, not to
mention artificial flowers and trees, miniatures of people in any style of dress or
uniform, etc.
In making motion pictures, such effects
as those here described are very easy to
produce, for the camera can be stopped
while certain changes are made in the objects or in the scene before the camera;
but in television, the action of the scene
cannot be stopped to permit such changes
being made and the action must be continuous. Thus, an entirely new method of
procedure had to be worked out by Mr.
Eddy and his associates.
51
A.C.-D.C. Circuit
Full Wave A.C.
Rectification
High voltage, oiled paper
Isolantite Insulation
Iron Core I.F.
Television "Sight Effects"
Band Spread
filter ,,s
5-nn elec.
C.W. Pitch Control
trolytics
R.F. and Pet. Panel
Both power lines filtered
Trimmers
Shielded. moisture -proof
Push -Pull Audio
bypasses
AC -Dc. communication -type superhet. built to hielteat
NOTICE
tion that the price of this bulletin (No. 346 -D) is
15e, direct from the manufacturer, or through
jobbers at the usual trade discounts.
Third of the new series
"Getting Started in Amateur Radio,"
by C. W. Palmer, E.E., in the next issue,
fewer Transformer Coil Winding Machines.
I 'aper
Layer Type. will wind series of coils
12 and 131' by 3" die. Sizes of machines 31'
35" long by
wide by 8' high.
Weight 100 to 110 pounds. Price, each
UP
pl
-
to
lv
25.00
will
_Small Paper layer Type.
wind coils up to
wide by í5Y die. Size 14" beg x 9'
high. weight 30 pounds.
25 3't'
II
$15,00
leash'
ids
quency; Antenna Measurements; Electromagnetic
Wave Measurements; Measurement of Electron Tube Coefficients and Amplifier Performance;Electromotive Force; Current Power; Measurement
of Wave Form; Modulation. Receiver and PiezoElectric Crystal Measurements. The index is par-
ticularly ample and
for April,
1939
easy to use.
212
that
5
C
Coll winding Machines
Winding
21/2" and 5" wide, 4 winding spindles
with every machine with different size
le of machines. 13" and 15" long z 5
z 6" high. Weight 17 and G 1
:Ir.
and
50-
R.F.
0.50
PP
Coll
Winding
Machines.
1.F.
1.r.
traight
winding arranged with turn counter and
automatic stop. Size L' long z 9' wide C1
z 7" high. 1Velght 20 pounds Price, each 'P 1.GO
J
1
IC-Hand
I'oil winding Machines. Arranged with turn
enter and 3" winding spindle. Cwt be replaced
any
with any
winding spindle. Size i0"
x 6' .x li". Weight 12 lbs. Price, each,... 'P
$6.50
Mai
days.
73
Phone Worth 2-8655
New York City
-6
Sts
--
--
EVERYTHING IN RADIO!
I tllltll MCI IN 1M WII RfM
Our
" r eek el M,a win. p.m ..d
n.bl o you ee puck.r yeur.
on oono
FREE
Ye. vat
gee.. F.,L.arr
WRITE
NEW
end
all
d,r hie
P.ccny
a
beak
o,d.
BURSTEIN-APPLEBEE CO.
1012 -14
McGee St
Please say you saw it in RADIO
o
&
K
t52Ay,t
TIME PAYMENTS?
Check these easy
h
Receiver
NC- 101 -X,
HQ -120 -X
NC -100A
)town
Price Payment
516, Breting 49,
NC-
81-X, NC -804X
New SX -23, speaker
SX -16, speaker
SX 17. speaker
RM E -69
RME70
$129.00
120.00
$19.96
18.48
99.00
127.50
123.00
149.50
152.88
138.60
19.40
19.60
22.60
24.10
15.34
21.10
termsMonthly
l'ay menta
8
OR
12
$14.21
13.22
$9.66
10.90
7.41
14.08
13.47
16.53
16.78
15.31
9.00
9.58
9.16
11.25
11.41
10.41
these ternis to suit your minienlenee.
can change
ltallietaflers. Ilanlnl arillnd.
City, Mo.
TELEVISION
www.americanradiohistory.com
OUR USED DEPT
reconditioned and guaranteed
ln Receivers and Transmitters at attrattile
has many good
M. M. LEVINE
nods
.eillilattison,
Your
every
Warren St.,
n.,
fair and square deal, every time.
Iiow art. Sargent, Bret Mg.
Patterson. Tellico, Itl'A Thnrdarson, Utah, etc.,
Receivers, Transmitters and Kits.
work-
Terms: 1/3 with order. balance S.D.B. L., F.O.B., N. Y.
84
a
Also terms on all
Nat Iona!, RII E.
hilly,
All machines overhauled and guaranteed i n
ing rondiU,m or money refunded within 30
Spays dens not permit to list all Items.
inquiries are solicited for machinery of
drsrrlpl ion.
Oakland. Calif.
-a
-is
I
Extra Gears to fit any of the above machines at
-mr each.
Also carry extra Darts for above
!oll
You, too, will find it to your advantage
to deal with me whenever you want to buy
a new receiver, transmitter, or any other
equipment.
My Personal attention to your wishes,
fair trade -in allowances, reasonable terms
for your convenience, prompt safe delivery.
and above all
sincere desire to give you
full co- operation
your assurance of complete and lasting satisfaction.
Be sure to write to me.
50
- i:,. 15tnr
E. M. SARGENT CO.
is the only Way to keep up a successful
business. That must be right, because since
1925 more and more men have been buying
their radio equipment from me.
1
'P
'39-
g believe
Coil Winding Machines. Wind
colt
200 atFeld
a time. size of spindle %" dia. x 4' long.
Flange 21/2' die. and 31/2" die. ]Lachine has automatic stop. Size Di' long z 10' wide x 7'$7
high. Weight 30 pounds. Price, each
AMATF URai-STREAM LINER
ties
NET PRICES
ATTENTION!
200
ieo
ps
eo
stages
n so
kiocck- outtton JO meters. 5 tube amateur superhet. write for details. Net price,
8:13.90.nEquals performance of sets selling for
many
2
Model 51 -AK. 9.7-550 meters, 110 rims AC -nC net $157.00
Model 5l -M K, 9.7 -3,750 meters, 110 volts .1C -DC net 5175.00
Battery l,1rH also ac a ilahle.
BOOK REVIEW
RADIO -FREQUENCY
ELECTRICAL
MEASUREMENTS. Hugh A. Brown, M.S. E.E., 384 pages,
trated, size 6" z 9 ". Published by McGraw-Hill illusCo.,
Inc., New York and London.
Mr. Brown, who is. Associate Professor of Electrical Engineering at the University of Illinois.
has done a masterly work covering his
most thoroughly. Not only does he give the subject
sary formulae for use in various types of necesmeasurement work, but also gives diagrams of apparatus
and lucid explanations on procedure. The book is
very well illustrated with circuits and schematics,
as well as a number of very interesting graphs,
etc.
The principal chapter headings are: Measurements of Circuit Constants; Measurement
of Fre-
kr
I I has
I3
the tubes.
WE PURCHASED THE ENTIRE QUANTITY OF 1,000 RADIO COIL WINDING
MACHINES FROM THE WORLD FAMOUS
ATWATER KENT MFG. CO. AND OFFER
SAME SUBJECT TO PRIOR SALE AT
LESS THAN 10% OF THEIR ORIGINAL
COST.
sets.
coil switching. hand
calibrated dials. break -in switch. phone Jack.spread,
built
l
Ideal
m1 al opeator's
"al receiver. Available In
any voltage and for A.C.. D .C. or battery. In 3
tuning ranges. An acce
accepted
bed s ndard in this field
since Ú0
MODEL Il NET PRICES
Net
Modes
Model II-AA.
.351
552.00
0.5-3750 meter a
557.00
Model Ì Ì - Ä.
0.090
meter,,
7.00
Immediate Delivery. Prices i lude power supply.
weaker and RCA tubes.
tl
51
de-
Selectivity c,mn sues favorably with larger
,nllilnpe
Features: Model
...birds. Continuous tuning range 9.7 to 3,750 meters
:hl
airplane
00(1 meterfl`
Is t police. each
broadcast.
.teurs and short
marked.
amateur. bn,adcastadanddt. hips bandsc
retive
rives almost complete
mplete i age section.
weak signals that arc unreadable without It.
1,,
rugged. dependable communication
ivey float
tion
go-getter
ar
ÓSeuLaneed too
unisti
made
justmets
factory thousands of miles away. R.F.
and detector trimmers. on the panel. allow wthe operator to align the
n
perfectly for any
mtrutn f the best
materials. wNo electmlyties frequency.
or deteriorating parts except
MODEL
circuit
C.W.
veloped.
-
Price. each
In reviewing the Thordarsnn Electric Mfg. Co.'s
"Sound Amplifier Guide," we neglected to men-
MODEL II 9.5 TO 20.000 METERS
Contlnuous tuning from the ultra highs to the audio
frequencies-the greatest tuning range of any advertUsed rreceiver. An exceptional CW receiver but good
N,hone an
roadcast. Designed for the
operator whose Interests are not confined to any
set of frequency hands. Flexible, quiet. easy
to ohcmle. ultra -sensitive. Employs tuned
R.F.
regenerative detector ircult^bcheved by manyand
to
e most sensitive
receiving"
ever
Good
values:
Send
sl:unp for
trade
prices.
HARRISON RADIO CO.
12 West Broadway, New York City
PRECISION CRYSTAL CONTROL
FOR ALL AMATEUR BANDS
BLILEY
CRYSTALS
BLILEY
N $3e35ifP
ELECTRIC CO.,
ERIE, PA.
753
6 -Tube, 1.4 Volt Superhet.
SALE!
CLEARANCE
on Surplus, and Army and Navy Merchandise
Rockbottom Prices
EVER WILL BEWhen prices are low we buy! They're low now -LOWER THAN THEY
hence this sale. Most of the merchandise is new-never used; some of it reconditioned.
100% satisfaction on each transaction or your money refunded.
sufficient
FROM THIS PAGE. Use the convenient coupon below. Be sure to include
, else the order will be shipped express. charges
extra remittance for parcel post ch
If full
deposit.
a
20%
require
collect. Any excess will be refunded. C.O.D. shipments money order-certified check
remittance accompanies order deduct 2% discount. Send
new U. S. stamps. No C.O.D. to foreign countries.
QUICK SHIPMENTS ASSURED
QUANTITIES LIMITED
ORDER TODAY
-
GYROSCOPE LIQUID
SPERRY
Made for U.S. Signal
Quick readings
Live
defrom top' accurate readeal>
KOLSTER RADIO
BEAUTIFUL
Brand New! Never been used before! Packed In their original
crates. Beautiful walnut highboy
cabinets designed for the one-
ings of graduations ' through focussing
rnsfying Iena on aide of instrument. Complete with level sights
and russet leather carrying case. Excellent for boats. boy scouts, campetc. A few turns of
ers.
re around its case makes it usable
battery
expensive Roister
time
OHr
receivers
never
.F,
tun
the
In
still In them and
used,
idget
modern
with them. A
chassis Installed in one
these beautiful cabinets would
ofreceiver
favorably along
certainly
omtem console
compartments r available:
Three co
a for
one for the R.F. tuner,'
batthe speaker and one for thebuild.
for
teries. What
Ing
a combination radio-phonoor a TELEVISION
.
.
graph!
. . plenty of room
RECEIVER
for a cathode ray tube. Measure
tae. IS.
high.
184 lbs.w
deen° -s
Ram
galvanometer. Sap. Wt. 3 tbs.
ITEM NO. 12
Your Prise
as
$1.85
P
-
p.
ITEM NO. 32
Your Price
VARIABLE SPEED UNIVERSAL MOTOR
110 VOLTS. A.C.
FOR
for
Made
machines
Dictaphone
$4.95
a
FAMOUS VACUUM CLEANERS
Rebuilt Like New
Guaranteed for 6 Months
o
ma-
We give you new brushes. bags, handles. belts
and other parts. The chassis is replated. All
moving parts overhauled. Money back if not
satisfied.
Simple to install: °R wires
from the line and 2 wires
the load. Sturdily
etal
in
heavy
structed
case. Sise: 84 " high.
overall.
deep.
5Wt. 13 lbs.
'T
M NO. 33
ITEM
to
-
$4.50
Price
Your
WESTINGHOUSE MODEL "WN"
ELECTRIC HEATER
1250 -Watts
115 -Volts.
11-Radical deEgn, c hinder
sign. cylinder
all attachments. Foot
control switch. Has 101 ev
Cl
tc.
mattresses.
urt ins, ma'
ies.
`
Shp. coa. IS lbs.
List Price. 580.75.
ITEM NO. 30
Your Price
-
hest
Radiant, clean Electrical
flip of
always there at the
the bathroom.
switch. Use it In the
anyden,
living
the
v` no dirt, n
where-it leaves
per designed for persoot. It i
wall
installation
manent
ent
is mountHeating element brick
and
heater
special
ed on
protected by a cadmium-plated
hazard! A special
guard. Not fire panel
the
protect
back
baffle
and
white- enameled iron frame. Size:
15
°a high.
.
w
23 .Iti41id
$16,48
NO. 105 -Motor dr:.eo
brush. Foot control switch. Marl,
housing.
otor
steel
12.ienameled
nch nozzle. Shp. Wt.. 24 lbs.
List price. 503.50.
HOOVER
ITEM
Your
high
NO.
Pria
$13.95
28
$5.49
ITEM NO. 34
Your Pria
NEW FUEL PUMPS
WESTON MODEL 562
A.C.-D.C. AMMETER
Brown
bilt
$1.25
35
U.S. ENGINEER DEPT
MAGNETIC COMPASS
ltrió
Wee
strnv Electric. A w
buy if only for the
pans it co tains. New-
is
tderful
never been nee
for
code pre
sIg al.
Ing. communications. etc.
Contains
.mne. high -re.
quemy buzzer
DIatI.
num contacts. telegraph
telephon
switches.
earphone. co denserc
transformers. chokes.
ting.
liding heightgoand
sliding
maIntalnin an
scale
metal
A
balance.
arounda the periphery has a
graduated scale Permitting actual readings of
all
tstoff
it as galvanometer by
around It. Excellent for
hikers. campers.
rangers.
forent
instrument Is recessed
case.
ShpntWI,
ra
electricity can
udennene
bopilne.
y
na girl
trailer
homes.
t.
f
use
5
rions.
ITEM NO. 18
Your Price ....
$2.65
'Coorn-
wan
inetruc.
case
Dicte invwoodens
diagram.
d
Shp. Wt.
i
ITEM NO. 36
Your Pria
BUZZER
AND
TELEGRAPH
FIELD SETS
PORTABLE
Designed to the high precision standards f the V.S.
overnment by Hersrheede.
m`runtedena
needle
ñéside
Jeweled
turns
fewrcW
bn
$4.45
.
ITEM NO.
Your Price
pumps.
ep"
never
new;
for
Can be used
gasoline, il. kerosene. and
muter. Take: standard hread
Mar input and output pipes.
Has v2 drive
3Vn diam.
4
overall. Shp Wt. 81/s lbs.
ITEM NO.
11)... 24
a .. W
Your
EastDesigned by Weston isfora the
precision Co. It
ma
magnetic -vane type ammeter
be
can
shunts,
suitable
with
which.
is
milliammeter too. It for
used
In ° diameter and designed and
base
Bakelite
p
panel mounting.
2
Shp.
Wt.
black- enameled
lbs.
$2.55
YourN:.'atl
The
could
counter
Gram-
American
o
Completely overhauled and
for Immediate service.
Dready
esigned for regular 110.
Ire A.C.
circuit. Servvicem en me
in their shops to of
tletc
current consumption
eép
irons
down. If dismantled.
alone would
thSts
e
parts
gear "train
ON D.C.
by
but
pcial
exccellent condition.
excellent
ri'
permits
D
able speeds up to 3000
Has shaft extends
from 'both ides of motor.
3>.a
Measures
11.
bp. We. 8a/
Mean. overall.
WESTINGHOUSE WATTHOUR METER
orate
COMPASS
(Continued from page 735)
various connections in the R.F. circuit ; the
filament, I.F. and A.F. circuits are wired
with the stranded push -back hook -up wire.
The I.F. circuit should be aligned from
the 460 kc. signal of a test oscillator if
possible. However, in lieu of a test oscillator routine, the following procedure may be
used. Plug in a pair of coils covering the
7 mc. amateur band and tune for one of
the "dotter" stations usually heard in this
region. A weak, steady signal is best for
alignment purposes. Turn up the mixer
regeneration control about three fourths
way full -on and rotate the R.F. (mixer)
trimmer condenser for maximum sensitivity. Now with an insulated screw -driver
or neutralizing tool, beginning with the output I.F. transformer, adjust each I.F. trimmer screw for maximum signal strength.
The beat- frequency oscillator is built on
a separate 4x3x1/ inch chassis and is
coupled to the 1N5 -G detector control grid
as indicated in Fig. 1. Condenser "C." indicated on the diagram, consists of two
pieces of insulated hook -up wire about one
inch long, loosely twisted together. The lead
from the oscillator must be shielded right
up to the point where it connects to condenser "C "; otherwise, the oscillator signal will get into the I.F. amplifier, causing
the detector to block on strong signals.
If the receiver is to be used for c.w.
code reception only, the beat- frequency
oscillator may be omitted and the receiver
aligned as follows : First, tune a "dotter"
signal as outlined above and, with the detector out of oscillation, adjust the I.F.
trimmers for maximum volume. Adjust the
mixer regeneration control just below the
point of oscillation and rotate the mixer
and oscillator trimmers for greatest sensitivity. Now, while tuning back and forth
across a signal, turn the output I.F. transformer grid trimmer screw to the right or
left until the signal can be barely heard.
Adjust the detector regeneration condenser
until the 1N5 -G is oscillating and advance
the I.F. trimmer, still rotating the dial back
and forth across the signal, until a point
is found where one side -hand is almost completely cut off.
The set will operate a loudspeaker with
fairly good volume on most stations. When
purchasing a speaker it is advisable to get
a permanent magnet dynamic type fitted
with a universal output transformer, which
will permit accurately matched output from
the 1A5 -G audio amplifier. When using
crystal headphones, an A.F. choke of about
30 henries. 15 ma. rating and an .05 mf.,
600 volt condenser should be connected to
the 1A5 -G plate as shown in Fig. 1. Be sure
that the coupling condenser is not leaky and
is of good quality.
Either a doublet or single-wire antenna
may be used with the receiver.
12
lbs.
Grid Coil Spar
rag
L3
$5.45
40 -T West
HUDSON SPECIALTIES
N.Y.C.
B'way
AT-439
40 -T West Broadway, New York, N. Y.
(include shipping
ordering. My full remittance Of S
I hare circled below the numbers of the Items
charges) Is enclosed.
stamps.
is enclosed (20% required). ship order C.O.D. for balance. (New D.S.
OR my deposit of 6
ro
Oscillator Coils
Grid Coil Spacing
L6
1"
4 turns
12 turns 1"
1%"
turns
15
32 turns I
52 turns 1g^
check or money order accepted.)
Circle Item No. wanted:
Name
City
754
11
12
16
24
23
30
32
33
34
35
36
Send remittance by check, stamps or money order; register letter
Tickler
Wire
Dia.
Band
LS
10 meters
turns 20 E. I"
20 meters
1"
20 E.
4 turns
40 meters.
11/,^
22 E.
6 turns
80 meters
1 VI"
9 turns 26 E.
1,4" 160 meters
16 turns 28 E.
ticklers
All coil forms are 5 -prong types. All form.
close -wound on "cold" or ground end of
3
f"
Address
State
Band
1
IT'S EASY TO ORDER-CLIP COUPON -MAIL NOW
HUDSON SPECIALTIES CO..
Dia.
L4
10 meters
20 E. 1"
3 turns
turns 1"
20 meters
turns 20 E. 1"
4
11/."
12 turns
V" 6 turns 22 E. 11/s" 40 meters
17 turns
80 meters
26
E.
11/:"
37 turns 114" 9 turns
1.)4" 14 turns 28 E. I Va" 160 meters
58 turns
of turns
number
Antenna coil L2 same wire and
as for tickler.
4
ORDER FROM THIS PAGE.
WE NAVE NO CATALOG.
Coil Data
Mixer Coils
Tickler Wire
if
you send cash or stamen
Please say you saw
it
in
RADIO
&
TELEVISION
r
RADIO
&
TELEVISION
NEWEST RADIO APPARATUS
New Band- Switching Pre -Selector
e
actually
refinements in its "gun" Structure to oldaln heft,
focus and modulating characteristics. The electron
aun is operated at the sante potentials and in th
sante manner as other tubes of corresponding typ.
and screen diameter.
NEW 5 -band pry- selector.
tinuous coverage front 5 to 185 ti-m- 11.6 to
64 mc.) with band- switching. has been announced
by the Browning Laboratories, Inc.
The unit employs an 185' tube as regenerative
R. F. amplifier.
Image rejection ratios of 500 or
more are obtainable, while the use of a high -Q
tuned antenna system affords marked gain in the
signal- to-noise ratio. R.F. amplification may be as
high as 800, even on the 5 and 10 meter bands.
depending upon the amount of regeneration used.
The main tank condenser with electrical land.
spread, used for tuning. is provided with a dial
calibrated for each of the five bands.
The unit. which is known as model No. Iì L-5 DX.
includes a filament transformer so that it may be
used with any receiver. It may be had either in kit
A
they
.
work
i
li
form or completely assembled.
C -D
New Set Tester
RADIO INTERFERENCE FILTERS
Like all C -1) products -Quietone Radio Interference Filters were tested under exaggerated "life" conditions before being
introduced to the industry. That's why we
can say with confidence . . . "THEY
ACTUALLY WORK."
Don't overlook this opportunity to increase your
sales with little or no effort. Extremely simple to
install, unobtrusive in appearance and available in
three colors to match room interiors. On your nest
call demonstrate Quietone -and see how easy it is
to increase your profit on each and every call.
Remember -for new profits demonstrate
Quietones, the filters backed by the
twenty-nine year C -D seal of quality. Attractively priced to retail from $1.00 up.
Cat. No. I66A on request.
C -D
Product of the world's largest
Full Line of Dual Atoms
THE Sprague midget line now includes a full
lute of dual combinations which, according to the
manufacturer. are the only small duals having
common negative leads. The new line include- a
manufacturer
:\ NEW set tester, which indicates the presence
of a signal throughout all sections of a receiver.
draws no current from the circuit at any time.
There are four input connections, one of which ico-axial cable for use on ultra -high frequencies.
The input impedance consists of approximately 5
nrmf. Three of the inputs operate on AC and one
..
of capacitors
CORNELL- DUBILIER
ELECTRIC CORPORATION
1O27HomJton Bled., So. P1amLald. N. I.
Cobla
AC or DC.
The circuit incorporates electronic rather than
radio engineering principles, and ntak es use of
four 6E5's, two 6F8's and one 76, AC output.
The instnmtrnt, known as the "Million Sig nalyzer,' simulates the functions of a vacuum
tube voltmeter, output indicator and potential
measuring device. It permits any 4 sections of a
set to be checked simultaneously and a service man
can learn its use in five minutes, its sponsors say.
Addrue: "COADU"
n
450 V. 8.8 mf.; a 50 V. 10 -10 mf.; 200 V. 16.16
and 8 -16 mf. units; a 250 V. 6.18 mf.; and 450
V. 8-16 tuf. The condensers are hermetically sealed.
New Style and Performance
to Modernize Your Equipment
at Amazing Low Cost!
New TURNER
Torpedo Crystal
Microphone
It's
to aire
New Type of Switch
A NEW line of carbon fixed resistors of solid
molded construction, permanently bonded into
one compact unit, has been announced by Consolidated \ \'ire & Associated Corporations. These
resistors are guaranteed within 10% plus or minus
and variation is maintained within a 55; average.
They are completely moisture -proof and non -inductive, having no capacity effect, and maintaining
resistance value over an extremely wide temperature range.
The same company also announces an iron core,
double- tuned, hand -expanding I.F. transformer.
Their new transformer line includes air core and
iron core I.F. transformers, mica -trimmed- permeability- tuned, double and triple -tuned units;
antenna. a.r., and oscillator coils; chokes, replacement primary windings, etc. These coils are prealigned and checked to assure their ready interchangeability and easy installation. Each is treated
with a special moisture proof compound to insure
permanence in the original adjustment.
Intensifier Type Cathode -Ray Tube
A NEW type of bier spin tube. called the
-Intensifier.- is considered by
manufacturers as "the first fundamental its
improvement
affecting sensitivity since the inception of cathode ray tubes 40 years ago.
The intensifier electrode takes the form of one
or two metallic deposit rings near the screen end
of the cathode -ray tube, and serves to accelerate
the electrons after deflection, to afford increased
brilliance without corresponding loss in deflection
sensitivity,
The DuMont 54 -9 -T five -inch tube is provided
with the intensifier feature, as well as several
for April,
1939
.t
A LOW capoc
ity lever- action
switch has just
been announced by
the Centralab con-
New Resistor Line
Sign
Sign
MODEL 55C
Side
15 oft cable.
Llee,
evel -acopa. 50.
7000
les.
Free
wiring ddiagrams.
Li, en ?r -I
RADIO
&
TELEVISION
www.americanradiohistory.com
t1.
NEW
Quality Torpedo.
Vualner
with Ibo
Turner Torpedo.
St. amlines ie,
anel finish. Streamline de
and absolute absente of
peaks redeye feedback.
perform many mi kes
selling for
morel Works
directly
grid of almost
amplifier.r.
rder today.
Write for Bulletin 41A
Ire,
all abour the late.t dein
pc.
tails
atinh,,nc.f all
models
appui
Ale nun
tuf! spinet 'Ikea:
write for Vol,
copy nalinil
1
"d
$1 595
1,
LIST
CEDAR RAPIDS, IOWA
P.rtinv of tie Itrusb Ihr-1; m.,
1939 CATALOG
248 PAGES
d
in
c
equipment
es,ks
THE TURNER CO.
Coaxial Cable for Hams
Please say you saw it
y
good looks and ttir
top
51K
cern. The switches
are similar to toggle
switches in
their action. as far
as the operating
lever is concerned,
but the contacts
are more like those
of
the familiar
rotary
switches.
They take up an
extremely small amount of space on the panel, and
multiple mounting plates are provided so that
they may be conveniently grouped.
A NEW type of coaxial cable is
being produced by the Transducer Corporation. This cable consists of a length of braided tinned
copper sheath, a length of tinned
copper cable and a large number
of ceramic insulated beads of
unique shape. The amateur makes
his own coaxial cable by stringing
the beads on the cable and then
forcing them through the braided
copper sheath. When the sheath is
clamped to the end beads, the cable
is ready for permanent ruse. It is
flexible so that it may be employed
for antenna lead -ins, cathode -ray
tube uses. P.E. cell connections. etc.
Its capacitance is 10 mmf. per foot and its characteristic impedance, 150 ohms.
w
e
SHOWING ALL LATEST
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Our 1939 Catalog Mailed F ree on Request
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126 illus
MODERN RADIO ESSENTIALS.
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306 Illus.
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EXAMINATIONS.
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THEORY OF VACUUM TUBE
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PRINCIPLES OF RADIO
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over 1,000 Illus.
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OFFICIAL SHORT -WAVE RADIO
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Metcalf of the former Bureau of Air Commerce.
Here are 15 up-to-date books on
radio and air conditioning. Modern
"When Mr. Metcalf and John Easton,
In
ery sense. ALL BOOKS UNIof the Aircraft Section, Bureau of
FORM -they contain 04 pages; 50 to
Chief
120 illustrations.
authors. Order
au
Commerce, first studied the principles
Air
Number.
of the Klystron and the Rhumbatron at the
2. MODERN VACUUM TUBES
invitation of the Stanford authorities, they
SUPERHETERODYNE
3. THE
saw immediately a broad general field of
BOOK
application embracing, in addition to the
5. HOW TO BECOME A SERV
blind landing system, a number of other
ICE
including obstacle detection, colliprojects
SETS
8. BRING
sion prevention, traffic control, en route
UP TOI G ELECTRIC
guidance, position fixes, and others.
8. RADIO QUESTIONS AND ANSW ERS
"The Sperry Gyroscope Company, as one
RADIO AND
9.
of the collaborators in the Isfetcalf blind
AUT MOBILE
landing development and as a manufactur10. HOME RECORDING AND ALL
ing unit, assumed the responsibility of deIT
INSTALveloping the Klystron in order to make
12.
LAT ON AND SERVICE
LATION
sure that the finished product would fit the
13. ABC OF AIR CONDITIONING
needs of the Bureau's blind landing system.
14. POCKET RADIO GUIDE
"Sperry's interest in this blind landing
IS. ABC OF REFRIGERATION
problem is very logical. The gyroscopic
16. PRACTICAL RADIO CIRCUITS
instruments, especially the directional gyro
WITH SET AN17. SERVICING
ALYZERS
and the gyro- horizon have added very conRESISTsiderably to the safety of en route blind
18. POINT -TO -POINT
ANALYSIS
ANCE
flying. The Metcalf blind landing system
RADIO
KINKS
19. PRACTICAL
involves the application of modified gyroAND SHORT CUTS
scopic instruments as well as considerable
PRICK: PREPAID
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prepaid (innot U.S.
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that are
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collect if sufficient
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are
physics department. Other scientists who
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ic
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W. W. Hansen. associate professor of
physics at Stanford and Mr. John WoodNEW YORK, N. Y.
yard. research associate in the physics department."
V. AC
A. C. ELECTRICAL POWER
from your
page 712)
is based on some original ideas of
" Buncher"
1/ere
;i
.
TECHNIFAX,
Division RT-439
560 W. Washington Blvd., Chicago,
Illinois
TECHNIFAX, Division RT -439
Seo W. Washington Blvd., Chicago. Illinois
Gentlemen: Enclosed please
stamps
sed
money order.
POSTAGE PREPAID.
d
tented) for which
One Copy of FORMULAS AND RECIPES For the
Man.
Practical
rne
V.
Name
Address
State
City
RT439, Chicago. III.
Please say you sow
it
in RADIO & TELEVISION
and "Gaither "_Klystron
Two rhumbatrons, called the "buncher"
and "catcher," together with other apparatus, make the Klystron. Its name comes
front the Greek verb "klyzo," denoting the
breaking of waves on a beach. This is
roughly descriptive of the action of the
device. for in the buncher Rhumbatron is
an oscillating electric field, parallel to a
stream of electrons passing through it. The
field is of such strength as to change the
speeds of the electrons by appreciable fractions, accelerating some, slowing down
others. After passing through the buncher,
the electrons with increased speeds begin
to overtake those with decreased speeds
which are ahead of them. This motion
groups the electrons into bunches separated
by relatively empty spaces. By passing the
stream through the catcher rhumbatron,
within which is an oscillating electric field
changing synchronously so as to take energy
away from the bunched electrons, a considerable fraction of the power of the electron bunches is converted into power of high frequency oscillations.
Advantages of the Klystron principle are
threefold. It produces strong waves; they
are at stable frequencies; and they have
strong amplification at the receiving end.
The present working minimum wavelength
employed by airlines in radio work is about
one meter. But the Stanford Klystron produces waves one -tenth that length. Such
waves, when eitted from a reflector one
meter in diameter, would radiate within a
narrow angle of only six degrees. The
Klystron's inventors believe wavelengths
considerably less than 10 centimeters can
be reached, thereby still further narrowing
the angle of radiation.
RADIO
&
TELEVISION
Electronic Television Course
SPRAGUE
ILoutiuucd it -am page 725)
order to transmit an image by television.
radio frequency ti lc%ision transmitter, suitwe insist pick up this image point by point
ably couplet) to an antenna for radiating
and line by line, and transmit each point
the electrical impulses picked up and prorapidly enough so that the eye may receive duced by the picture
tube. The deflection
each complete picture in rapid enough suc- circuits mentioned
in the above paragraph
cession to give the illusion of notion. Mo- serve to deflect
the electronic cathode beans
tion pictures in our theaters. when pro- ill a vertical
ECONOMICAL CONDENSERS
and horizontal direction, while
jected on a screen, are repeated at the rate it sweeps the mosaic
screen or target elecof 24 pictures per second and each picture is trode, as the case may
a , a
those
interrupted twice by a shutter incorporated flection circuit causes be. The vertical dethe beam to move
in the projecting apparatus. so that the eye
from top to bottom 60 times per second and
receives 48 periods of light and 48 periods
Jobs
the horizontal
circuit causes the
of dark for each second that we view the beats to move deflection
Just because they're the smallest
from left to right 13,230
midget dry electrolytics on the markettimes per second. The sequence in which
just because they're priced eo amazingly
the picture is scanned is as follows: lines.
low does not mean that Sprague ATOMS
No. 1, 3, 5, 7, etc., to 2201/2 are scanned
are cheap. Not by ten jugfuls! And
they've got more features than any other
in the first /60th of a second (see Fig.
Feature Articles April, 1939
similar unit -more sizes -more voltages
5-A). The beam then returns and scans lines
-more real "guts." They'll build up to high',
RADIO -CRAFT
surges
Nos. 2, 4. 6, 8, etc.. in other words, the
leakage
loer powerr factor, The
beam scans one -half of the picture. then
Sprague vent
ABSOLUTELY
Radio Abroad in 1938
Review
GUARANTEES
against
"Omreturns and scans the space between the
ups." ATOMS are self- supiwrtManufactured Speech
Ina. You can mount
lines previously scanned, giving us 60 halfn hip
tub,ilars.
paper
use
'eat
t
for
any
At Long Last -Static -Free Radio!-Part
frames or 30 complete frames or pictures
replacement job.
per
second.
Announcing the "Novachord
This
process
of
scanning
each
Electronic
picture twice, is called interlaced scanning
DUALS, TOO!
Music's New 163 -Tube "Baby"
because each pair of odd lines is interlaced
ATOMS are made
A Modern Amplifier for Recording and
)most
by an even line. This is analogous to the
minao
Playback
with common
negamotion pictures in the theater where each
tive led o simplify
An Easily -Built 3 -Tube Midget Broadcast
iring. They fit in
picture on the film is projected upon the
theyre
a anywhere-and
whale artf a lot betSuperhet.
screen twice while standing still in the pro,
ter
syle condensers
sesay
man,
A Home -Made String -Music Pickup
jection aperture.
sise. An
Making a Shop -Type A.C. to D.C. Power
listnfdata only ATOM
Interlaced scanning reduces the amount
dual 8 -8 at
Iy
Supply
Ask your !nt,ber 31.
of flicker in a picture when viewed, because
day
wr,,, r,,r
the eye receives two impulses of light;
How the "Beam -a- Scope" Works!
Caialul.'ui
whereas in sequential scanning (scanning
lines 1, 2. 3, 4, 5, 6, 7) the eye would pera-ive each picture but once and consequently
SPRAGUE
picture. In modern television, we hava' the apparent projection rate would be
slower and cause more flicker. During the
stepped up this rate of projection to 30
PRODUCTS CO.
interval of time that the vertical deflect'. -n
complete frames or 60 half- frames per secNorth Adoms Mo.. s.
circuit is sweeping the beans downy
ond.
the
horizontal
Television standards in the United States,
deflection circuit is nI :.0
the beam from left to right rapidly enough
as agreed upon by the Radio )l.untfacturers'
to
Association Television Committee. standscan 220% lines. It might be well t,
ardized 441 lines per picture, 30 pictures mention at this point that the electronic
beans
moves in both directions; top to butper second, interlaced (i.e., 60 half -frame
ALL METAL
UTILITY CABINETS
pictures), an aspect ratio of 3 to 4 (3 units tons and left to right in a linear manner.
and
in height to 4 in width) negative transmiswhen reaching the end of a line or
Indispensable for keeping under
and key all
VALUABLE parts including yourlockQSL
frame returns to its starting point in 1 /10th
sion and 10% of each line and frame
or SWL
alBards. Top drawer has 10
lotted to synchronizing impulses. These of the time that it took to travel the line
compartments
for
small
or
parts. In the 6 and 8 drawer
frame. as illustrated in Figure 5. It will
standards and their relation to the transcabinets, the two lower ones
he
perceived that the voltage or current
mission and reception of television images
are made into one unit to
hold tubes, crystals, meters.
will be more fully explained in this and wave-forms assume the shape of a saw -tooth
pick -ups,
camera
lenses,
and it is for this reason that oscillators
subsequent chapters of this course.
films,
micrometers.
slide rules. etc. In the
Figure No. 4 shows in block diagram the producing this wave shape are often termed
smaller
compartments
sae'-tooth oscillators. This quick return of
essential apparatus required for the transyou can keep resistors.
condensers. bolts, nuts.
mission of a television image. It consists the electronic beam causes a large signal
washers, etc., from being "borrowed ".
of an iconoscope, ntonoscope or image dis- in the output of the pick -up tube which is
sector, vertical and horizontal deflection used at the receiving end for a synchronizHeight
Depth
Width
List
ing pulse. When delivered to the grids of
circuits, amplifiers, power supplies, and
drawers
y'
s,
a
G3.50
the sweep circuit oscillators it causes them
s drawers
st_ne
G'
0.50
liar with lock and key
to keep in step with those of the transmitter,
.50
Finished
In
wrinkle,
olive
green.
thus giving perfect synchronization between
Amateur's Discount. 40%, Write for complete catalog.
Answers to QUIZ on page 719 transmitter and receivers.
your dealer
show you a sample. If he has
As
none,
ur
send your o.der direct.
Due to the fact that the television signal
1. b
Is transmitted ncyatfvely (the carrier of
KORROL RADIO PRODUCTS CO.
2. aC, 6E, cA, dF, el), JR
the transmitter increases in amplitude for
350 Greenwich St.,
Dept. 439,
New York City
3. c
the black portions of a picture anti de4. e, minimum; d, maximum/
creases
in
amplitude
for
the whites). these
5. d
synchronizing impulses represent the high6. a -too costly
If
CANNON -BALL
est
modulation
capabilities
of the television
7. c & d
transmitter
and
when
received
they repre8. all-- though not all are classed
is a
as
movie stars, their major activities being in sent in the picture what may he termed
"blacker
GOOD
HEADSET
than
black"
and consequently are
other fields.
of no significance, as far as the eye is con9. b
For clarity of tone
cerned
when
viewing
Cannon - Ball sensitive
an image.
10. d
phones. Assure depend11. aC, 6F, cE, dA, oB, JD
In
Chapter
No. 3, we shall discuss the
able
performance. Guar12. cA
radio and video frequencies involved in the
anteed to give absolute
13. d-KOIL, Blue; WOW, Red
h-a,s,ission and receptions of television
satisfaction. Write
14.
experimental
Headset Headquarters
images. Nec elements of cathode ray receiv15. c
for folder T -4 illustrating tubed. 'lectro- static and electro-mog16. Most often c or b; sometimes
ing complete line,
b & e;
nelfr
deflection,
and
the
modulation
of
a
almost never a or d
cathode ray electronic bean, by the transF.
C.
CANNON COMPANY
17. b
mitted picture impulses.
SPRINGWATER. N. Y.
for
Economical
1
-A
"-
I
sI
-
-
'
G
It's a
It
c-
for April,
1939
Please say you
saw it in
RADIO
&
TELEVISION
757
Mc.
Call
6.090
CRCX
12
6.090
6.081
YVIRD
6,080
W9XAA
6.079
6.077
OAX4Z
Call
Mc.
6.070
CFRX
6.070
VE9CS
RV59
6.030
OLR2B
MOSCOW, U.S.S.R., 49.75 m. 5-6,
Irregular.
10 -II pm.
PRAGUE, CZECHOSLOVAKIA,
11.875 mc.) Off the
(See
49.75 m.
air at present.
6.023
XEUW
VERA CRUZ, MEX., 49.82 m.
Ltd. Mon., Fri. 5.30 -6 am., 11.15
am. -2.15 pm., also Tues. aad
Thurs. 8.15 -9.15 am.; Sat. 11.15
am. -3.15 pm.; Sun. 10.45 am:
1.45 pm.
MARACAIBO, VEN., 49.32 m. 6 -II
pm.
CHICAGO, ILL 4934 m., Addr.
Chicago Fed. of Labor. Relays
WCFL irregular.
6.060
W3XAU
6.057
ZHJ
DJC
6.017
HI3U
STATES,
II
Sun., also Sat.
.6.054
GERMANY, 49.34 m.,
Addr., Broadcasting House. 4.50 II pm.
LIMA, PERU, 49.35 in. Radio National 7 pm.-I.30 am. Except
6.050
6.015
PRA8
6.010
OLR2A
PEREIRA, COL., 49.52 in. 9.30
12 n., 6.30 -10 pm.
GSA
DAÓ
ENGLAND,
HPSF
I
6.045
XETW
6.040
W4XB
m.,
P
449,599
TRY,
49.63
U.S.S.R.,
KHABAROVSK,
am.
2 -11
RVIS
6.045
am:
BARRANQUILLA, COL., 49.65
Addr. Emisora Atlantico. II am:
11
pm.; Sun. II am:8 pm.
COLON, PAN., 49.59 m., Adds.
Carlton Hotel. Irregular.
HJIABG
TORONTO, CAN., 49.42 m. Relays
am.-I2 m., Sun.
7.30
CFRB
IO am.-I2 m.
VANCOUVER, B. C., CAN., 49.42
m. Sun. 1.45 -9 pm., 10.30 pm:
am.; Tues. 6 -7.30 pm., 11.30
pm. -1.30 am. Daily 6 -7.30 pm.
pm.
am.
pm.-I
HJ6ABA
E
6.050
La
regular 7-11 pm.
MIAMI BEACH, FLA.,
-3 pm.,
W OD.
pm.-12
9
1
49.65
6.010
COCO
6.010
VK9MI
PRAGUE,
49.92 m.,
m.
6,010
CJCx
7.30 am.
SYDNEY, NOVA SCOTIA, 49.92 m.
Relays CJCB 7 am. -I pm., 4 -8 pm.
1.30 pm. 8.30 pm.
6.007
ZRH
ROBERTS
6.001
ZRJ
JOHANNESBURG
HEIGHTS S. AFRICA,
m., Addr, (fee ZRK, 9.606
mc.) Daily exc. Sun. 10 am. -3.30
pm.; Sun. 9 am.-I2 n., 12.153.15 pm. Daily exc. Sat. 11.46
pm. -12.50 am.
m,
I
TANANARIVE, MADAGASCAR
49.42 m., Addr. (See 9.53
12.30. 12.45, 3.30 -4.30, 10-11
Sun 2.30 -4.30 em.
6.065
SBO
6.060
-
mc.)
am.,
MOTALA, SWEDEN, 49,46 m. Relays Stockholm 4.15 -5 pm.
TANANARIVE, MADAGASCAR.
49.5 m.,
11
12.30-12.45, 3.30 -4.30,
BOSTON, MASS., 49.65 m., Addr.
WIXAL
6.040
6.033
HP5B
6.030
VE9CA
University Club. Irregular.
PANAMA CITY, PAN., 49.75 m.,
Addr. P. 0. Box 910. 10.30 am.pm.
2, 6.10
CALGARY,
10-
12
am.
6.005
HP5K
49.94 m.,
Addr.
S.
AFRICA.
S.
African Broad-
cast. Co., 3.30-4 pm. exc. Sun..
COLON, PAN., 49.96 m., Addr.
Box 33, La Voz de la Victor. 7 -9
am., 10.30 am: pm.,
(Continued on page 761)
I
m
n.-
ALTA,am.;A 5ún 49.7
11.84
mc.) Wed., Thun., 4.40 -5.10 pm,
HAVANA CUBA, 49.92 m., Addr.
Daily 7.55 am:
P. O. Box 98.
12 m., Sun. until II pm.
S. S. KANIMBLA, 49.92 in. (Travels
between Australia and New Zea-
Relays
m.
CZECHOSLOVAKIA.
Addr. (See OLR,
land). Sun., Wed., Thun. 6.55-
MEXICO, 49.6 m. Ir-
TAMPICO
pm:
ddr, (See 6079Nm.) 19430 pm.
SANTIAGO DE LOS CABALLEROS
D. R., 49,85 m. 7.30 -9 am., 12 n:
Sun.
2 pm., 5 -7 pm., B -9.30 pm.;
12.30 -2, 5 -6 pm.
PERNAMBUCO, BRAZIL, 49.84 m.,
Radio Club of Pernambuco, 4 -9
I
4951m.
m.
Addr.
m.
BERLIN,
6.020
PHILADELPHIA, PA., 49.5 m. ReFri., Sun.
lays WCAU Tues.,
I
pm. -Mid. Wed. -IO pm.
P
lO
98.
Av., Independencia
a
lays WLW Tues., Fri.,
am.-I2 n., II pm. -2 am.; Wad.
5.45 am..12 n., 9 pm. -f em.;
Mon., Thurs., Sat. 5.45 am.-2 am.
GUIANA,
SRI.
Sun. 7.45.10.15 am.;
49.35 m.
Daily 4.45 -8.45 pm.
-
6.069
page 73L)
Call
6.030
Sun. 5.45
GEORGETOWN,
VP3MR
Mc.
Stations
CINCINNATI, OHIO, 49.5 m.,
Addr. Crosley Radio Corp. Re-
WBXAL
6.060
Sun.
6.075
-W
(Continued from
BERLIN,
DJM
S
n.
HONGKONG, CHINA, 49.26 m.,
Addr. P. 0. Box 200. Irregular.
NAIROBI, KENYA, AFRICA, 49.31
m., Addr. Cable and Wireless,
ZBW2
VQ7LO
6.083
World
TORONTO, CAN., 49.26 m., Addr.
Can. Broadcasting Corp. Daily
7.45 am.-5 pm., Sun. 10.30 am:
m.
ONE or ALL
5.11
pm.
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Let's Listen In with Joe Miller
fr ont page
(Continued
(S DA.)
XGAP yet too. promptly. Reports on
XPSA, 7.01 mc., Kweiyang. are desired. Don
Williams. \\'6, reports XPSA.
JAPAN
JLG. 7.285 ntc.. Tokio. is broadcasting daily
to Europe from 2:30-4 p.m.. but very difficult to
hear on East Coast. bring in the 40 meter amateur
band. and too early for such a frequency to be
well heard. even if in the clear.
Ntw "Jap" phone, to be added recently are:
JVW. 7.2o; JV\Y2, 9.673; JVW3, 11.725;
JVW4, 17.823 mc. (I.D.A.)
JIA, on approximately 15.80 me.. in Formosa.
recently QSL'd by Jap phone QRA. along with
JVL, another phone. J1A was heard at 3:30
a.m.. but may also be heard much later, being
frequently lugged at 6.7:30 a.nt.
Murray Ituitekant reports JFZC. 17.64 mc.,
the Chichi in Maru. at 7:45 a.m., JVT. 6.75 mc.,
at 3:50 a.m., and JVA. 18.91 mc., at 7:30 a.m.
FB OM! Ralph Gozan. also \V2, got a JVJ veri.
JVE. 15.66 mc., heard here at 8:10 a.m.
Anyone reporting Jap phones now will receive
very prompt and certain reply, if report correct,a
with their new attractive card, recently illustrated, so now is the time to clean up on J's!
afternoons till 5 p.m., or so during
week -ends. TAQ, 15.195 nie., is reported on daily
5:30 -7 a.m. W. G. Layton, W3, states that the
reason why no QSLs of the Turkish stations have
been received, at least as yet. is due to the very
poor mail service there. Mr. Layton relates he
once was in Turkey. and after mailing some 50
letters to the U. S. front there, found that not
one ever reached its destination! He adds that
evidently the P.O. employees collect stamps, hi!
Turkish Ambassador please note. This mention
is made in the light of universal plaints regarding lack of answers front TAP -TAQ reports.
Ian Jamieson, England, reports TAP at 3
Jllilliammeter
JOTTINGS
him.
G. C. Gallagher, \'6. reports a "FB" QSL in
ZHO. 6.185 nie.. Singapore. A nice catch, OM!
Jack \\'ells recently got a Flt YCP, Dutch Borneo
veri,, and gives our of column all the credit.
Thanks. Jack! He also was sent a clipping of
a New Zealand paper in which his excellent report
of VK9\II, S.S. Kanimbta, was commented upon,
this by Miss Eileen Foley, who answers the reports on 91\MI. Whatta thrill!
Hal Clein, \1'6. states ZNB, which Fl] catch
in Bechuanaland recently QSL'd to him, is
the friendliest station on the air, judging from
his very courteous, personal letter front the operator, Chips Ilrittz. ZNB sends a gorgeous QSL,
recently shown here.
HAM STARDUST
20 meters has been rather dead during the past
month, mid-Jan- to mid-Feb., but the advent of the
A.R.R.L. 1)X contest. and the fine DX condi-
ANGOLA
tions soon to be experienced as Spring evidences
itself, will doubtless bring much interest back to
this usually reliable amateur band.
As this issue will be published just before the
Contest begins- we hope a couple of tips will be
of assistance to you.
Last year, European "hams" were heard between
-4 a.m. on East Coast, and many rare calls were
"logged," so watch 20 at this time, from the
time y-ou read this.
Tlten, too, some Asiatic DX may be heard between 2 -4 a.m. as the J hams are licensed to operate at certain periods daily, and one of them is
2 -4 a.m.,
when a number of J's were well heard
last year. J's are also licensed to operate 6 -8
a.m. This period is the best time, of course, for
East Coast reception of Asiatics.
Africans can be heard during afternoons. and
North Africans at same time as Europeans, which
will roar in during afternoons, and occasionally,
around 10 -10:30 p.m. Europeans will often hold
up during afternoons till 7 p.nt.
Now to reports:
CR6AA. 7.614 mc., at Lobito, was recently
"logged," but with a weak signal, at 4:30 p.m.
on a Saturday. CR6AA operates Weds. and Sats.,
2:45.4:45 p.m., and supposed to be also on Mons.,
but has never been heard or reported on this
day. This makes 3 frogs. heard oil this "FB"
catch. the 9.6 and 7.177 me. silts being verified.
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Section 284 Harmon Ave.
1
DX REVIEW
-F08:\Ä, 7.10 mc..
-I
Volt -Ohm-
Bert Wolfe, W6, reports the first VU card
veri, from VUD2. Also reported by Bert is a very
handsome QSL from ZHP, Singapore, FB! Bert
says Bangkok, Siam, and CSW will not QSL to
U.S.S.R.
Papeete, is not
Q SL'ing reports, according to numerous contplaints from readers. We don't know what can
he done, except that registered reports may help.
FO8AA always has had a bad "rep" for QSL's,
but thought answering after long delays. usually
has conic through. We will send a copy of this
issue of our column to FO8AA, when published,
hoping notice will be taken of this item by the
Station Director, and the situation remedied.
FRENCH MOROCCO - CNR. 12.83 mc., Rabat,
heard using the usual .side -band secrecy transmission at 1:30 a.m.. when frequently logged.
NORWAY -KC, 9.53 flic.. Oslo. has been verified by Ray A. Bernhardt. W6. a nice catch
West Coast. LKQ, 11.72 me.. is also reported for
on
same schedule. 4:30 -9 a.m., daily. Sims., from
2:30 a.m. Another transmitter on 15.166 mc. is
reported on after 10:30 a.m., but may be only on
Sundays. (1. D.A.)
TURKEY -TAP, 9.465 mc., Ankara, continues
A.C. -D.C.
p.m. on.
RV15, 4.275 mc., at Khabarovsk. Siberia. will
positively not verify, according to letter received
from Radio Centre, Moscow, recently received by
Harold B. Clein, \V6. We had wondered why our
report of RVIS was not answered. but this
clears things up, although a big disappointment.
Gail T. Beyer, \V9. reports similar failure to
elicit a QSL for ROL', Omsk, from Moscow,
so it seems the only stations in the U.S.S.R. that
may be verified are SW Broadcasters in Moscow.
RKI. 15.083 me., and RAN, 9.60 mc.. reported
on Sunday at 10 p.m.. with RKI very strong, by
Daryl Sebastian.
TAHITI-
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PYRO
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ASIA
VU2FU. 14375, India, announcing as "France.
United," reported by Hal Clein, \V6, who also
reports a "beaut" of a QSL from VU2JN.
"FB" DX, Hal!
VU2CQ. 14120, and VU2BG, 14145, also reported by Gail Beyer, W9.
(Cmitinued on following page)
The Finnish Short Wave Broadcasting
Transmitter at Lahti, Suomi (Finland)
Georg. loc. 25° 39'
` °c
r.
r
60° 59' N
E,
.. -_';nr
Size of Box:
12v, x 8!;
inches
We acknowledge with thanks Your report
on our short wave transmissions It checks well
with our o
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f,D
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OIH
Oli
The t kW tramonitter You Fore hewnt. The two
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31;68
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19,75
16,85
13,92
9500
11780
15190
17800
21550
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for April, 1939
B y are:
-14.
Our short wave transmitter is daily on the
air and usually relays the regular Finnish Broadcasting Programmes.
,1
;ns,
Oy. Suomen Yleisradio Ab.
Landen Yleisradioosema
Attractive "Vert" Card -one to
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Outfit will be forwarded by Express Collect if
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WELLWORTH TRADING CO.
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Please say you saw it
Shipping weight,
such as Leather, Wood, Cork, Bakelite, etc.
Plug the Pyro-electric pencil in any 110 volt
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By the use of the Pantagraph included in the
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GM(.
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RADIO
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TELEVISION
Dept. RT-439
Chicago, III.
759
Let's Listen In with
Joe Miller
(Continued from preceding page)
PK1JR, 14300; PK4KS, 14320; PK4JD,
text books give you an excellent
RADIO FANS EVERYWHERE: t :ese fine ten cent written,
profusely illustrated and
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GERNSEAC'S EDUCATIONAL LIBRARY
fAMOUS
N! 5
BEGINNERS
RADIO
G
DICTIONARY
u
aa
GERNSBACKS EDUCATIONAL LIBRARY
HOW TO READ
RNSB ACK
OCCT(0NAI
N!?
14020, Java, reported by Mike Soplop, W8. PK4's
are in Sumatra. PK4KS also reported by Ralph
Gozen. W.?. PKIRI, 14350, and PK4JD. 14090,
reported by Ian ,Jamieson, England. PK1\"\I.
14100. and PK4KS reported by Gail Beyer.
l'KIGL, 14080, heard here at unusual time of
4:45 a.m.
XZ2DY, 14350, logged at 7:45 a.m. by Mike
Soplop. W8, a Fll catch!
KAIME, 14260; KA1CS, 14145; KA7EF.
Philippines, reported by Mr. Soplop, also. KAIME
also by Mr. Beyer.
ZC6EC, 14316 (announced) Palestine. heard
at 8 a.m. by Ralph Gozen, W2. A real ace!
FI8AC, 14080. French Indo- China, reported
Ian Jamieson, England. XU8ET, 14050,
by
9 a.m., by Mario Cassino, W2.
AFRICA
a
"ZS" stations too numerous to mention, and
data on them will be of little use now, So. Africa
having more or less faded out for the seison.
SU2JR, 14070. Egypt, by Ian Jamieson.
VQ4ECJ, 14010. Kenya. logged here at 3 p.m..
also by Ralph Gozen.
good sig.
VQ2H &, 14070 and 14320. Northern Rhodesia.
reported by Ian Jamieson. Also VQ2FJ, 14130.
LIBRARY
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Title: ALL ABOUT
AERIALS. Book4
NEW YORK, N. Y.
N! 8
a
i
DX!
FB8AD, 14310, Madagascar, also by Ian.
FB8AH, 14340, reported by Torn Jordan. W8.
FB8AH also by Norm Kriebel, W8.
We skipped over VQ2PL. whose FB card is
illustrated this month. Vg2PL reported on 14415
by Mr. Soplop and Mr. Kriebel. Peter Lowth. who
interesting letter we
as VQ2PL. tells us in the
received with his QSL, that his ambition is to
some time relay the roar of the famous Victoria
Falls in Northern Rhodesia to the fellows here.
It would be interesting, indeed! Peter is located
but 5 miles from the Falls. Ralph Gozen also
reports VQ2PL.
CN8AW, 14110; CN8BA, 14070; CN8AL,
14070 and 14110; CN8MT, 14100; CN8AN,
14040; CNBAY, 14130; ('N8MB, 14068; CN8AI.
14070, all reported by Messrs. Kriebel, Gozen,
Beyer and Y.T., besides Ted Bottema, so French
Morocco is well represented this month! Also
CNSDE V. 14055. by Y.T.
Also from Egypt is reported SUTAIW, 14130,
and SUTAX. by Norm Kriebel, 1AX being reported on 14050 by Norm, and on 14028 by Gail
Beyer.
ZEIJX. 14030. by Norm and Gail, and ZE1JR.
14074. by Ted Bottema, these in Southern Rhodesia.
CT3AB, 14050. 3 :30 p.m., is a "FB" catch in
Madeira, for Gail Beyer.
40 METERS
CT3AN, 7090. Madeira. heard regularly around
8:30 p.m., E.S.T.. by Ian Jamieson. England.
CN8AJ, 7050. French Morocco. was logged by
Norm Kriebel. along with other Africans and
:30.4 a.ns. CN8MT, 7050, by
Europeans, from
1
Ralph Cozen.
FA8AW. 7070. FA8CF, 7180. Algeria, also by
Norm. FA3WW. 7260, and FA8CF by Ralph
ì
Cozen.
Best reception on this band was in early December.
N
--
RADIO PUBLICATIONS sol HUDSON
8-RADIO
T
NtWrORlt WY
FOR BEGINNERS
Hugo Gemsback. the internationally famous radio pioneer.
author and editor. whose magazines. RADIO & TELEVISION and RADIO -CRAFT are read by millions,
scores another triumph with this great book. Any beginner
who reads It will get a thorough ground work in radio
theory. clearly explained in simple language. and through
the use of many illustrations. Analogies are used to make
the mysteries of radio as clear as "2+2 is 4 ". It also
contains diagrams and instructions for building simple
radio sets, suitable for the novice. stook tells you how
transmitters and receivers work. how radio waves traverse
space. and dozens of other interesting facts about this
most mo.h -rn moans of communication.
OTHER DX
ZL2BE, 14210, and ZL2JQ 14260, heard after
7:30 a.m. by Norm Kriebel. These in New Zealand. ZL2BE. 14170. also by Ted Bottema.
ZAICC, 14130, Albania, reported by Ian Jamieson, at 2:15 p.m. Sun.
SVICA, 14055, Greece, by Y. T. SP1MR, 14025,
Poland, by Y. T. OH20I, 14160, Finland, Y. T.
and
Mr.
Gozen.
ICI METERS
Some fine DX has been reported and heard on
this band of late. and we do hope good conditions
will continue on this exciting stretch of kilocycles.
From Africa, numbers of ZS stations are heard
from 10 a.m. -? p.m.. peaking around noon.
Other Africans on 10 are: SUIMW, 28400,
Y. T. and Norm Kriebel. this one from Egypt.
ZEIJZ. 28400. So. Rhodesia. by Y. T.
CN8BA, 28150, CNBAV, 28150, in French
MAIL COUPON TODAY!!
Morocco, Y. T.
7
From Oceania are heard ZL2BE, 28500, and
Ir
ZL2BT, 28400. by Norm Kriebel.
RADIO PUBLICATIONS. Dept. R &T -4.39
101 HUDSON STREET, NEW YORK. N. Y.
Also from New Zealand. Y. T. hears ZL3IF,
28600, ZL2FY, 28120, ZL2BT and ZL2BE. the
Gentlemen: Please send immediately, POSTPAID, the
latter usually very fine. along with 2FY.
book numbers circled below. I am enclosing.. - -septs
From Greece, we have SVICA, 28200.
-each book being 10c.
From Latvia. on the recent I.D.A. special broad8
6
7
4
5
1
2
3
cast arranged by Roger Legge. an old reporter,
and now editor of I.D.A.'s Ama. touring, we had
O Send FREE list of 48 special 10e publications.
the good fortune to hear a FB catch in YL2CD,
28080. YL2CD was heard R6.7 solid. very good.
Name
Some late tips from Hal Clain. W6: YN3DG.
14256. 7128. will gladly QSL, but only if a U.S.
10e piece is sent him. Also. XAR2LA. 14370,
Address
aboard a Norwegian freighter, giving his name as
Gunnar. and is a ham in Oslo, when home.
¡qty
State
We wish to thank all you OM's for the swell
if
letter
order
-register
or
money
Remit by check
bouquets you've thrown at us. and do hope we can
you send cash or unused U. S. postage stamps.
continue rating your praise. We sure appreciate it!
IN
760
Please say you saw
it
in
RADIO
&
TELEVISION
RADIO
&
TELEVISION
-W
World
S
Stations
(t,ontiuurd front page 758)
Mc.
Call
6.005
CFCX
MONTREAL, CAN.
49.96 m., Can.
Marconi Co. Relays CFCF 6.45
em.-12 m.; Sun. 8 am. -10.15 pm.
6.006
VE9DN
DRUMMONDVILLE, QUE., CAN.,
49.96 m., Addr. Canadian Mar.
eoni Co.
6.002
CXA2
MONTEVIDEO, URUGUAY, 49.98 m.
Addr. Rio Negro 1631. Relays
LS2, Radio Prieto, Buenos Aires.
7.30 -10.30 pm.
6.000
6.000
ZIA
SALISBURY, RHODESIA, S.AFRICA,
50 m. (See 6.147 mc., ZEB.) Also
Sun. 3.30 -5 am.
XEBT
MEXICO
Addr.
CITY,
MEX.,
O. Box 79.44.
P.
am.
50
8
SHORT WAVE COIL
SN CO
11
5.975
OAX4P
LISBON,
PORTUGAL,
The
Trotter
m.,
am. -I
.
PECEtV TRSBITTIEPS
ZaCrots
Pd. ,ut1CAT0N5
5.968
HVJ
5.950
HH2S
RADIO PUBLICATIONS
HUDSON STREET NEW YORK, N. Y.
t..a..,a..i.e..n.a...w®w.,.a..
97
CARACAS, VEN., 50.26 m., Addr.
Radio Caracas. Sun. 7 am.-10 pm,
Daily 7 -8 am., 1.1.45 pm., 4 -9.30
or 10 pm.
VATICAN CITY, 50.27 m. Off the
air at present.
PORT-AU- PRINCE,
m., Addr.
pm.
5.916
YVIRL
YV4RH
of
50.37
P. O. Box A103. 7 -9.45
MARACAIBO, VEN., 50.52 m.,
Addr. Radio Popular, Jose A.
Higuera M, P. O. Box 247. Daily
am.-1.43 pm., 5.13.10.13
pm.; Sun. 9.13 am.-3.13 pm.
VALENCIA, VEN., 50.68 m. 5.9.30
ZNB
MAFEKING,
BM.
BECHUANALAND S. AFRICA, 50.84 m. Addr.
The Govt. Engineer, P. O. Box
106. 6 -7 am.
-2.30 pm.. Ex. Suns.
5.900
TILS
5.898
YV3RA
SAN JOSE, COSTA RICA, 50.85 m.
6 -10 pm.
BARQUISIMETO, VEN., 50.86 m.,
Addr. La Voz de Lare, 12 n.-1
pm., 6.10 pm.
5.885
11198
5.875
HRN
1
5.855
5.845
I-411J
YVIRB
SANTIAGO, D. R., 50.95 in. Irregular 6 -II pm.
TEGUCIGALPA, HONDURAS, 51.06
m. 1.15 -2.16, 8.30 -10 pm.; Sun.
3.30.5.30. 8.30 -9.30 pm.
SAN PEDRO DE MACORIS, D. R.,
51.25 m., Addr. Box 204, 12 n.2 pm., 6.30 -9 pm.
MARACAIBO, VEN.,
Addr. Apartado 214.
am.,
9.45
pm.;
pm.
5.826
TIGPH
51.3
m.,
8.45 -9.45
am. -12.15 pm., 4.45.
Sun, 11.45 am:12.45
11.15
SAN JOSE COSTA RICA, 51.5 m.,
Addr.
11
Tice, Apartado 800.
pm., 6 -10 pm, Relays
Alma
am. -1
TIX 9 -10 pm.
5.813
TIGPH2
send you six back
numbers of SHORT
WAVE & TELEVISION
assorted, your choice, for
5.768
YNOP
GUATEMALA CITY, GUAT., 51.75
m. Casa Preidencial, Senor J. M.
Caba lleroz. Irregular.
MANAGUA, NICARAGUA, 52.11
5.740
YV2RA
SAN
m.
8 -9.30
pm.
CRISTOBAL,
VENEZUELA.
m., Addr. La Voz de
Tachira. 11.30 am.-12 n., 5.30.9
pm., Sun. till 10 pm.
HCIPM
5.145
OKIMPT
6.145
PMY
4.995
VUD2
4.950
VUM2
4.905
VUB2
4.900
HJ3ABH
QUITO, ECUADOR, 52.28 m. Irregular 10 pm. 12 m.
PRAG U E,
CZECHOSLOVAKIA,
58.31 m., Addr. (See OLR, 11.84
mc.) Fri. 4.45.5.10 pm.; Saf. 5.155.40 pm.
BANDOENG, JAVA, 58.31 m. 5.30-
-All
for April,
1939
have been sold.
We accept U. S. stamps, U. S. coin, or money
order. Rush your order today.
Every copy of SHORT WAVE
Mc.
4.880
RADIO & TELEVISION
4 -39
Hudson Street, New York. N. Y.
Gentlemen: I enclose herewith 70e, for which you
are to send me six back number copies of SHORT
99 -101
WAVE & TELEVISION
as
follows
-all
-all
&
Name
Address
TELEVISION
Cur
State
Call
VUC2
U. S.
CALCUTTA, INDIA, 61.48 m. Addr.
All India Radio. 6.36 am.-I2.06
ARMY
SIGNAL
Om.
4.880
HJ4ABP
MEDELLIN, COL.,
pm.
4.876
ZRD
DURBAN
m.,
61.44
m.
4.542
HJ3ABD
8.1I
till
HJIABE
CARTAGENA COL., 62.46 m., La
Voz de los Laboratorios Fuentes.
Addr. Box 31. Daily 8.30 am.-11
pm., Sun. 10 am.-9 pm.
4.780
HJIABB
BARRANQUILLA, COL., 62.72 m.
La Voz de Barranquilla, Addr.
P. O. Box 715. 11.30 am.-1 pm.,
4.30.10 pm.
SANTA MARTA, COL., 62.85 m.
11.30 am. -2 pm., 5.30 -10.30 pm.
except Wed.
4.740
HJIABJ
HJ6ABC
LAMPS
The lamp
BOGOTA, COL., 61.95 m., Addr. L.
Nueva Granada, Box 509. 12 n:
2 pm., 7.11 pm., Sun. 5.9 pm.
4.800
4.772
CORPS
SOUTH AFRICA, 61.5
Addr. (See ZRK, 9.606 mc.
Daily 12 m. -3.45 pm., Sat.
4 pm., Sun. till 3.20 pm.
IBAGUE, COL., 63.25 m. 7
m.
pm: 12
-
Don't Miss
Latest TELEVISION
and FAC- SIMILE News
IN THE
of
MAY
NUMBER
Please say you saw it in RADIO & TELEVISION
www.americanradiohistory.com
100
uses
Stout Signalling
Night Bowling Alleys
Trailer Lamp
Night Motor Boat Races
Auto, Truck and Trailer
Camps
Tractor Light
Camp
Light
Barnyard Lighting
Night Fishing
Radio Shacks
Bungalows
Picnics, etc.
Large size-12,
Scouts Signalling
wide.
Is- high Infs
,t. fitted Vwith
O" silver plated reflector 110
a,
nothing to break, Parkedeeel.
...voodoo
in portaoe
,n
r
uh hinged
,
latin
ad
Eve,y
v o tains
. therproof e , sep
r, nil
n l
nailii, 2 extra d IA
!r
rmnailing
Igoe key and let a U.
U.S. Army
Manual.
4hipping
,v Ions
,a
II am.
DELHI, INDIA, 60.06 m., Addr. All
India Radio. 7.30 am.-12.30 pm,
MADRAS, INDIA. 60.61 m. Addr.
All India Radio- 7 am.-I2 n.
BOMBAY, INDIA, 61.16 m. Addr.
All India Radio, 7 am.-I2.30 pm.
BOGOTA, COL, 61.19 m., Addr.
Apartado 565. 12 n.-2 pm., 6.11
pm.; Sun. 12 n. -2 pm., 4.11 pm.
is a chance to get those copies.
As only a small supply of back numbers on
hand, this offer will be withdrawn as soon as they
rents.
70
52.23
6.735
contains information which you should have. Here
The usual price for six copies would be $1.50,
and most publishers charge a higher price for
back numbers over one year old.
We can supply only the following back numbers: Dec., 1930 ; Feb., April, June, Sept., Oct..
1931 ; July, Oct., 1932: Jan., April. Oct., Nov.,
1933; Jan., Feb., Mar., May, June, July, Aug..
Sept. 1934 : 1935
issues except January,
February and March : 1936, 1937, 1938
issues:
1939
issues to date.
If you do not specify copies, we will send assorted numbers to fill your order. Note, we cannot
exchange the copies for ones that have been sent
to you.
H.
TGS
limited time
a
only. and as long as
they last, we will
SAN JOSE, COSTA RICA, 51.59
m., Addr. Senor Gonzalo Pinto,
5.790
70¢-
For
pm.
1.900
6
-+IEY FELLOWS ! BACK NIIMBiRS
SHORT WAVE AND TELEVISION
LSENT ANYWHERE IN US. FOR
HAITI,
11.43
5.920
For a copy of this handy book, send
45c in U.S. Coin or stamps to
o
Voz del Centro del Peru. 8 pm.
YVSRC
PRICE 25e PREPAID
m.,
Addr. Rue Capelo 5. 3.30 -6 pm.
HUANCAYO. PERU, 50.16 m. Le
on.
5.970
Contenta Briefly Outlined
Tuning Inductance Charts
Coil Data for T. R. F. ReOne
Zsctllndyne
Two rube Rnndspreader
noC
rime Old Reliable
2 -orne clone
2 Winding C'ils -lO -Slit. Meters
Doerle JTube "Signal Gripper" Electrified
a -Tube nnndspreader
for the Hain
Cenral Coverage Coils on Ribbed Forms
Coll Dal for
porkt or S -W Converter Ultra W Coils
Coils for -V Superbets
Experimental Coils
-W Antenna Tuner
Most Popular . -W Tuning Circuits
s Self-Supporting Transmitting
Circuits Employing Cois
Described
All Rand Antenna Tuner for Transmitting
Plug in Coils for Exciters
Frequenry.W'avlangth
version Chart.
ceivers
COpR Ñ
50.15
f
S -W
1
CS2WD
o
8..
DpT
DATA BOOK
Every experimenter knows that the difference between
and
a poor radio sot is usually found in the
constructiona good
of snort mila. coil winding information vitally
important and in
the new coil book all dope appears. isThere's
illustrations which
give instructions onn how to ins
Is,
times of
and
to plut them. Everydimensions,
experimenter
Wilke it also contains
this
complete data on all types needs
receiving coils,
together with many suitable
circuits using these
c Is. Also complete data m, various
ypes of transmitting
o Is
th many tr osnratir
circuits
h u s exciters and
amplifiers using the various coils
described.
óRjN;AN
End of Broadcast Band
5.977
and ONLY
1
l
sk
xeO
g
rot. erlre
o at
we covemmene a b o u t
the
F.O.B. N. V.
825.00)
Send for catalog containing full descript, ,. ,.r it,,,
..od many orner ¡ntorestq
m
terns.
GOLD SHIELD PRODUCTS
Dept.
RT -4.9
330
Greenwich
St.
Nt.
York
761
The Martian Flash
COMMERCIAL NOTICES
(Continued front page 720)
images exactly as if one were viewing them
from the outside. It took a long time for
Martians to become adept in this form of
reception, as there are a minimum of ten
different wave forms necessary, all being
transmitted simultaneously to accomplish
this purpose.
Let us suppose, however, that a Martian
does not wish to receive the television images
being transmitted. That again is very simple. As the Martian antennae is made in
such a fashion by nature that it can be
straightened out or curled at the tip, (as
similarly accomplished by insects,) it is
only in the straightened condition that the
interception of the oscillating waves is possible. At the saute time and using the same
Under this heading o c advertisements of a commercial nature are accepted. Remittance of 10c
per word should accompany all orders. Copy should reach us not later than the 10th of the month
for the second following month's issue.
AGENTS WANTED
350 Oscar B. Kusterman, 297 DeKalb Ave.,
Shield Products,
Gold
l'reenwich St., New York City.
PATENT ATTORNEYS
foot.
SELLING GOLD
Leaf Letters for Store windows; Free
samples. Sietailic Co., 446 North Clark.
300%
PROFIT
Brooklyn.
N.Y.C.
PLANS 18 RECORD-BREAKING
Crystal sets, S\t' record 4250 miles.
with Radlobuilder" -year. YSr, laboratories, 7700 -A East 14th, Oakland.
California.
ANY RADIO CIRCUIT DIAGRAM
Y O t' R
INVENTORS-PROTECT
tlon
rights before disclosing purr invention
to anyone. Forni "Evidence of ConCORRESPONDENCE COURSES
ception"; "Schedule of Government
and Attorneys' Fees" and instructions
Order mentioning manufacturer's
CORRESPONDENCE COURSES sent free. Lancaster. Allwine & Romand educational books, slightly used. mel. 436 Bourn Building, Washington. name. model. r ('at AM: Free. Surprenne
Publications. 3727 West 13th. Chicago.
All sub- D. C.
Sold. Rented. Exchanged.
jects. Satisfaction guaranteed. Cash
CRYSTAL, SELEITIVE CRYSTAL
CISL-CARDS-4WL
paid for used courses. Complete leset plans 15e. Trent. Dux 291. New
tails and bargain catalog free. Send
Brunswick. N. .1.
none. Nelson r mpauv, 3391 Manhat
100 NEAT S\VL CARDS PRINTED
with your name and address sent posttan Building, Chicago.
SHORT WAVE RECEIVERS
paid for $7 hunch of samples and RST
Chart for fire cents In stamps. W1BEF.
INSTRUCTION
WE STILL HAVE A FEW l'SED
16 Stockbridge Ave.. Lowell. Mass.
Deserle receivers Models D -38. BSI
RADIO ENGINEERING. 11110ADQSL. SWL CARDS, SAMI'I.ES and 7('. reconditioned by fartory, at
casting, aviation and police radio. Free. The Royal l'ress, Meriden. Conn. 40r7 off. See Dec. 1938 Radio and
Television for description. Oscar B.
servicing. marine and Morse telegraphy
Kustennan, 297 DeKalb Ave.. BrookRADIO
taught thoroughly. All expenses low.
lyn. N.Y.C.
Catalog free. Dodge's Institute. Colt
.1
STOP:-BEFORE YOU
SI.. Valparaiso. Intl.
SONG POEMS WANTED
short wave receiver. send dine for our
diacircuit
24 -page catalog containing
MISCELLANEOUS
WANTED
POEMS.
ORIGINAL
grams and information On over
Doerle short wave receivers and trans- songs for immediate consideration. Send
7 MILLIAMMETEI1. HEAVY RUB ber insulation, high voltage lacquered mitters. See Dec. 1938 issue for page poems to Columbian Music Publishers.
Toronto,
Can.
Ltd.,
Dept.
K.19.
few
of
our
models.
cable, suitable for transmitter. 2c per ad describing
Chicago.
means, the sounds are also received and thus
the Martian can hear and see what is going
on in the distant television transmitter, without any special apparatus of any kind. If
Itll'
he does not wish to receive the television
program, he merely relaxes his antennae,
which then curls at the end and the reception is blotted out, due to the changed wave
length of the head antenna. If anything of
special national importance arises, special
A
impulses are transmitted which are received
T WORD
by- the curled antennae and the Martian
twill instantly know that something of unUnder this heading we accept advertisements only when gouda are offered for sale without profit.
usual significance has occurred. He will
the
reach
us
not
later
than
orders.
should
Copy
Remittance of 3c per word should accompany all
automatically straighten out his antennae
10th of the month for the second following month's issue.
and will be ready for reception in the flash
SKY CILIMPION 8 TUBE REINTERNATIONAL CORRESPONI)ItIRANI) NEW 11.\DI0 ttl'G $4.25
of a second.
eeiver
electrical mechanical
perfect
(money back guarantee). 160 -80 meter ence School Radio Servicing
Slosta- condition $35.00. Alvin Abrams. 20
There are all sorts of refinements, but
;0 -80 1938 edition, conmplet e
crystals (ground) $1.15, blanks:
New
York
Laurel
11111
Terrace.
K.Y.C.
meter $.85, 40 -20 meter $1.00. radin cello. 2714 Bainbridge Ave.,
I will only mention one: Suppose a
tulles (most popular types) only 20e City.
SKY BIDDY $15.00. Sw'3 $12.50.
Martian is busy with his own work and can
each.
Richard Dawson. 1308E, The
HAVE SW -3s. SKY BUDDIES, F117 $19.00, RME -69 $89.00. W9ARA,
Dalles. Oregon.
not find the time to have his television other apparatus for sale. Send for Butler. Missouri.
(1lIIItAItl) ' "RADIO PHYSICS and
sound program at the time. That makes
('ourse.'' second edition $3.00. Rider's List. John \\'oinark. Dimmitt. Texas.
IN
SALE,
SEVERAL
NEW
FOR
two books ¢Servicing Superheterodyne.
little difference because he can enjoy it
t'BACTICALLY NEW INSTItI(TO- foc cases 8' PSI speakers for 38 or 39
Servicing Sets by Resistance Measurelater on if he wishes to. In his own home or
ment $1.50. Frederick Aldridge. 1228 graph. seven tapes $8.98. wlldtV, 16 Buick $10 or $12 list, $2.75. A. Jonas,
Flint,
1019
Wood,
Mich.
St..
Medford.
Mass.
Sanger
Shepard St.. Petersburg. Virginia.
in his abode where he performs his work
there is a certain recording apparatus which
for a whole Martian clay, stores not only
the television and sound programs but many
AN°
other programs too. These programs can
then be reeled off as it were, from any
NO ADVERTISEMENT TO EXCEED 35 WO RDS. INCLUDING NAME AND ADDRESS
MUSaccepted from any reader in any one issue. All dealings
intended
sold. It
department is
time of the day simply by pressing or
the U.
you
using
board.
Remember
above
T
be
a
to
dens.
swish
o
force then bene
d therefore you are bound
mail in all these transactions
manipulating a few buttons. If, for inexchange radios. torts. ahonographsi cameras. bicycles,
offer
anything
Laws.
Describe
S.
Postal
you
h
U.
the
sporting goods, o pokey forgthesesann
can.
accurately and without exaggeration. Treat your fellow
announcements.
stance, at what would correspond to noon
we e
wish
to be treated.
you
the
men
n
he
way
by
made
statements
for
y
not accept responsibility
make this dewelcome suggestions that will help
on Earth one would wish to get the noon
readers.
helpful
to
o
interesting
and
can
be
partment
o
e
advertisement
Only
freely.
Use these Columns
month's issue.
program at midnight. manipulation of a few
Copy should reach us net s later than the 10th of the month for the second following
buttons will bring that program instantly.
TRADE 5x8 PRINTING PRESS.
WILL SW AP 163131 PROJECTOR.
HAVE ON RR 2.000 BOOKS TO
rack. all accessories.
pans, stamps, - meter trans- complete modern National
At the end of the day the programs are
trade for anything I can use. Your radio
with
receiver
FBTX
power
for
used
low
banks
for
radio
2913 Ruckle. ceiver,
list for mine.
automatically obliterated.
transmitter. All letters ans. Anthony rolls. good working condition. Trade
l.
Indianapolis. M.EEpstein.
C. Conlin, 83 Westfield Rd., Holyoke. notion picture camera, projector (Key One can, if he so desires, go to the Centone) both perfect working rendition
SWAP A N S L E Y PORTABLE Mass.
for Sw'3 National. D. M. Sheehan.
radio and
tral
Office and get a program no matter
POWER
PARTS,
RADIO
HAVE
nsnowshoes,
Bradley
Franklin
St..
Stoneham.
WILMS. 96
bile° 20 ando90,
tsn
old it is. Thus, the other day, just for
how
t'rsley model 51. two tube portable
Mass.
Want
sand
electricOlio
watch. tube battery
battery set. Silver key wound Street.
STAMP'S,
EXCHANGE I400KS,
the fun of it, I went to the Central recordrifles. cameras. field glasses or what
for? Joseph Kubik. 37 Pine
have you. John Haynes, Doe Run. Mo. precancels, Buro prints for all radio
ing office and enjoyed a very fine television
Gt. Barrington. Mass.
films. taxidermy supSUB - books. 16 nun history
EXCHANGE MAGAZINE
magazines. Send
plies, natural
HAVE FIRST FIVE VOLUMES criptlons
and musical presentation which had been
equipment.
for
transmitting
comMagazine
want
Joseph
Stories
list
ith
lists.
swap
Science wonder
subscriptions to any maga- your
recorded 1,250,000 years ago! And I am
Bourette. Box 66. So. Station. Fall
plete. first class condition. Amazing Will give
transformers
crystals.
for
good
Stories dating from August. 1928. zine
here to tell you that it was a good program
other transmitting apparatus. Like River. Mass.
Others. Send for list. Trade for com- and hear
w'ANTED-265 SISIFD. PER SEt,
from t-. H. F. fans. 100r; (ISL.
munications receiver. radio equipment. to
too. It showed, among other things, special
7
ill.
11111. Ont., Hon split stator condenser.
Richmond
It.
It.
Alexander.
J. H. Hood. 37 Club Drive. Greenville. Canada.
transformer. T40 or 153. Will swap
ultra -telescopic view's of the planet Earth
S. C.
for?
W4FQX,
Edw.
KC. crystal
BROWN BOBBY DOUGH 1961
during the midst of one of its periodical
WANTED. FOR COIN COLLEC- nutHAVE
Blackmon.
2955 Memorial Dr..
T.
course
dumbbell
Jewett
machine.
also
lion 1899 Liberty head nickel.
five volume en- Decatur. Ga.
ice ages and when Man as yet had not made
want Indian head pennies. Will swap complete. McFadden
WILL TRADE 5 -TUBE T.R.F. RE- his initial appearance. Close -ups showed the
of physical culture. Want
200 U.S. stamps for nickel or for four cyclopedia
set. relver, meters, RCA-852's. Cardwell
clasher.
barbell
rug
Von
Schrader
Dawson.
(4) Indian head pennies.
courses. or chat have condensers, Thord. 1200V. C.T. at 300
wild animals still in full reign on the
1308F, The Dalles. Oregon.
our Harold 1'. Sheehan. Caledonia. MA for what have you? write E. Kam ANI) prorrespondenre
planet and as far as Man was concerned,
merling. 616 N. Central. Chicago.
Minn.
TRADE AC'l'OMORILE
motorcycle license plates with collectors
HAVE l'HIIAO OUTPUT MI:TER,
all I saw was ape -like beings. It made me
repeating
STEVENS
.222
buy
HAVE
Will
and
countries.
in other states
tube Ghirardi's Remo Physics Course. 2nd
et and big rifle. headphones, Atwater -Kent
shiver to think how far the Martians were
if cheap. Swap shortwave
0
-1
D.C.SI.A..
edit..
radio
parts.
want
iin
sewing
reversible
radio,
attery
Or? Anthony
r. n
Western hat for old
D. P.D.T. Federal antieap`eity switch.
art
ahead of us even BEFORE we existed.
Shtmienus. Newport. N. J.
answered. Steve Nagy'.
a
ant ers All letters
doble
radio, nuother
WANT SAMPLE OF FLINT AND manuals. ?. Harold Hitcher, w7GIt1I. Main St., Box 273. Twin Rocks. Pa.
This is the third issue of The Martian
other rocks. minerals (ore). foreign Ito. Newberg. Oregon.
S\\'AI' I RCA ELECTRIC SET.
coins, samples of wool (graded) and
servicing,
$5 microscope, variFlash. The publishers would like to know
SWAP GOOD FOREIGN STAMPS needs
parts
samples from five different breeds of
stamps.
radio
able
condensers.
penkinds of things. for Lincoln pennies. Indium head
if you like it. Vote and mail coupon.
sheep. Have all
dollars or other and speaker for auto radio, working
e
FOR SALE (NON COMMERCIAL) 3
.
11
l
EXCHANGE
BARTER
-
FREE!
1
c
s
-
1
ttmike.li
1
t'.
Street.
South
nies. Columbian half
coins. Karlerbeks. 905 501 order, or?
Raymond. Maple
I Gulley Falls. Mass.
Ate.. Moline. l
WILL GIVE 59 FOREIGN ST.AM1'S
WANTED -ALL 8 SIM AND (OMM
for 15 P.S. cmntnem. except NIL\.
and prnjert tar. Offre
10 films. also Camr
Anthony.
Chicago,
barks.
greeting igcords :und view arils
10 tax tokens,I
some cash. Write to Joseph Nagy.
f'. S. commem. Orville Arnold. Box 311. and
Jr., 9010 Kennedy Ave_ Cleveland.
lfenryetta. Oklahoma.
Ohlo.
HAVE: CHARLES ATLAS PIIYSIWANTED -- SKY-BUDDY REcal Development course. western Klee
undut'
heavy
Phonnnnotor eeiver. Will trade 7000 different. radin
trie pickup.
views. SI °clin g's
turntable. Want S-'V 3 or other short used postcard
receiver. Paul O'Donnell. 83 manual. Supreme 333 analyzer. etc.
wave
St..
Sagamore Avenue. Atlantic. Massachu- Joseph McGuire. 5022 So. 38th
setts.
762
!'.
Omaha.
.
Nebr.
Please say yc
Raymond
Blnonrsburg. l'a.
Hover, Rural
3.
FICTION
SCIENCE:
ntagazlnes. Wonder. Amazing. Astoumling. etc.. 1931 to 1936. Will trade
S. roon
each for 15e fare in mint
stamps before 19 ^8. Fred W. W'aylulan,
280 Pike St.. Carbondale. Pa.
MILL T(RAI)E NEW li -TU1tF IsATten. set, Silvertone radio for typehwriter. musical Instruments or what
are you? Value $In to trade.
Owens. wellhtgton. Alabama.
HAVE
47
I.
(('ontinned
saw
if
in
on opposite
RADIO
&
.
THE MARTIAN FLASH
C.
STOP IT
KEEP IT
Nalllt'
\ddre
pane)
TELEVISION
RADIO
&
TELEVISION
Rotating Beam Loop
BARTER and EXCHANGE FREE ADS (continued)
(Continued from page 722)
Twenty-four inches of % in. by % in.
iron (an old coal scuttle handle) was fitted
with one bolt as a bracket near the top,
and a 12 -inch piece of dowelling was clipped
in this for the rope to rule over.
A 6 -inch wheel was fixed to a 30 -inch
length of iron rod (from a car bonnet
hinge), and this rod is passed through a
hole in a hard wood block near the bottom
of the mast, and through the side of the
French window- frame. A car window
winder mikes a neat job on the inside and
one complete rotation moves the loop 360 °.
A compass card under the handle gives the
bearing.
The
WANTED
TYPEWRITER.
BEST
Will site teen dallas rush no will exchange fifteen dollars worth Indian
stone pipes. pots. bowls. copies of
A 193o F'l'L'l'ONE S AND I. WAVE
receiver complete. in perfect condition.
value
$14.00
AC -DC.
Trade
for
bicycle of like value in Arizona only.
Send stamp. William Sickle, Rte. 4.
Box 1153, Torso.. Arizona.
prehistoric. fur il. Mrs. Suenan.
1. Box 125. Saul lads Obispo.
California.
',VANTER 4115 KC \T \1, V tit.
HAVE CA.D:ILtS. tW.t'l'CHES, 55 tube It meter, crystal mike. (leave
Stanley plaie.
Stanley brace,
titer
typewriter Oliver.l Green ii3er phono machines, .studio licha, Ma.sunie books. motor an,i xtal pickup, uulthneter and
\Vau small pla[vua .,
kodaks, oscillator. Triplett. S'VSM.!, answered.
small radin, ladin beaks naand ,ourses 'Let's Swap." Eldon Wooster. teesRoute
'
A.
Sizemore. Box
483. bora. Ohio.
Jarkuet. Ky.
I1.\ \1: Sx -11 SI PER SKYlli UEIR
HAVE MIÂNV Pur. MIECII. R. cirh Ilallirrafters
speaker. 8 n
Seienee. whet meth. t..agazirrs. 1-tube camera, 2 sets Sw'K0 Broils, numerous
potable battery t
t,
last, '30 tube. parts
ami tubes. Want lute Model
Want radin parts.:'i_tl h-a unity' snilah, bp otltbmod. ore C. Brown, 333 Hazel
or tube -lest ln- e ausformer. Robert St.. L.,m aster, l'a.
Dick. ion W. John Sq., Martiu,t,urg
'fl'I;E
Sud parts.
S.
if
u
W. Va.
and
Till E'i'O.NF:
broadcast
Al'
S111)1tT-
mantle
re-
WANTED -- UNIVERSAL S.It. ceher ai 18 -tube AC Siitertone
Ir
lapel alike. lu nut.
tat. .ßz3 tube, met broadcast receiver. .22 pump rifle.
0 -100 MA steter for that do you want Speakers. Need radin
books, parts.
In exchange or what Imre you got be- meters, etc. Al Slaney. 3517 Hennepin
sides. John 11. Walker. 97 -34 Alaty'ne Ave.. Minneapolis. .11nn.
Ave., Cornea, L. 1.. S. V.
HAVE $39.30 ELGIN N.t'ITR.tL
WANT MODERN Si II' tlECE1 1'l3 gold watch, pair photo cells.
Nat' or Ito A. Snap Candire course. Melt ups, elec. razor, pair magnetic
crystal
iuiulructiigrapli and Iaprs. Si,,,d -X tones. 2-tube A.C. et. want Sky
bug even mole)'. Ilivr
particulars. ISUddy or receiver capable of operatM$ilsl
cm, colonic.
-tal bands 000 ing speaker. L. warren Morris, Wilu
Aerial
?M'AI'
reeeiter
will
NT1N(1 FbR R.W.
F.11. 1'11
or transmitter parts nr? L
pa)' spot rash for a small begin-
ner's V.W. transmitter if reasonably
priced. yl liai be complete. Lawrence
Pleasant,
P.O.
Itox
58.
Mattoon,
I
llua,is.
t\'.\\TEI/: r, -METER RECEIVER.
Will trade f3.00 chemical set. ORA
L
Krehel,
3581
land, Ohio.
E.
U.S.A.
St.,
1114
Cleve-
WILL TRADE RADIOS. AMI'LIflers. and watches. Want good typewriter. Eugene lox. Ilarrisunville, ulo.
SlAVE BRAND NEW At'DI'M)IfIt'MI
complete
com
guitar
Wamplifier
Went: goal
case.
with
velocity or crystal micr,Have N.It, I, Radio and Television course complete.
What have
you? Walter Iturdine. Waynesville, O.
HAVE CODE PRACTICE OSCI1.
lato, one tube audio amplifier, radio
magazines. ,cant miepalmne, 0-1110
nia milliaunneter
0.'m0 colt voltmeter, 0 volt tibrator transformer and
phone.
vibrators.
William
Rim-ha.
Pawnee
City. Nebr.
The aerial itself was made possible by
SWAT'
FUIt
Tlt-LNSMITTElt
the discovery that steel cored copper wire
pans. Garage battery charger, Presto.
lite tank, auto radio. plumber's fireis now available cheaply, and two 8 foot
pot, washer motor. t yrs. Radio- Craft.
lengths of 12 S.W.G. made two very stiff meters iii,, John
Maytag engine, 2-tube Kadette, large
Pantosml, 3259 N. liamstown. Pa.
telescope, oint 't r $200. E. C. Warloops. The open ends are
inch apart and Philip SI., Chile.. Pa.
TRADE: COLLEITION OF AP- ren, Capar. Miel,.
WILL Tlt.\IH: 220110 VOLT IN- proximately 4.01111 postal card views.
cemented into two small pieces of bakelite duction
HAVE BRUNSWICK. J11. POOL
coil giving 114 inch spark. for 12 ga. repeating shotgun. Crosby table.
48' by 31' (folding legs) with
that happened to he available, but celluloid radio parte
swill as variable condensers. "filer" radio. electric shaver. want
M agate balls. triangle, two
(tikes. eta. James Mrshall, outboard motor. stamp eolleelion or set
or glass tube would (Io as well. (Fig. 2.) carbon
unfinished
wise! cues. Very good condi1728 Paeltie .Ave.. Ali:ultll- City, N. J. Ehat have you? Answer all inquiries.
tion. 'vaut
equipment, or?
Eight stand -off insulators were screwed
l'ente. Box 22. :ri'gecllle, Ili. \'ereoe Jaws, testing
IL'V'E MIDST ANYTHING. POST'il Carlton Ave.. Trencarols.
1anenirs.
or.,
TRADE
ton.
In
swap
N.
J.
trans
COMPLETE
L\
`SALLE
to the ends of the wooden cross, and small portetlon tokens of street for
cars. buses, accounting course. rosi $130.00. for
HAVE Al101'S CANDID l'.\MLF:IIA.
brass clips (springs from lamp batteries)
de, Roan anywhere.
answer all. superbet radio, 30 watt amplifier. servnew. Mani U. S. stamps or short
B. Mdtnbie. 10311 Big Falla Ave.. ice equip.. or. G. IL Heidenbrand, Like
ware equipment
hold the two loops firmly in place under Ak,
set or that have
on. Ohio.
Si aplehurst.
Nebr.
ur Jantes E. Wilkehn. Ilex 693,
the terminals.
WANTED 1011 CIt''ST. \L5. TIIAIhE
WANTED- .\C -Sit3 WITH COILS Elkins, W. Va.
for
15
Popul:u
Gdncaors
tubes
and
power
(newt'
supply
or
or Sky ChamAt present a waterproof cable, twin complete
II-\VE ONE 5!'l'Ett1Olt ALL
set of UST macs .lune '37 pion or Howard or other suitable SW wave signal
e rrat or with audio frerubhercd flex. covered with Empire cloth
to '38 and Once other late editions or remiser. Trade 555 meal Bit clarinet. quencies.
wand a - meter transmitter
radin
from
All
letters
December
to
February.
answered
I
ddleston.
018
or a receiver n' anything that you
(or oil cloth), as used for car lighting, Stanley IfortIo', R5GTN -A ANS. 15 .m01 2511, Street. Temple, Texas.
have to swap. Write what you have.
St., lint Sprinngs. Ark.
is being tried. This has worked well
ONE
PROJECTOR
354' Will answer. Albert Sebesta. Snack.
ir:\\'E l'lAhl'I.F :TE N.R.I. IUURSE lens. for showing solid WITH
object like Texas.
up to 14 Mc.; spaced feeders are heavy 110281,
and Transmitting. postcards, snapshots, onto screen. up
WANTED POSTCARD SIZE
and clumsy to mount. A matching stub is with codeServicing
instructor. with 5 tapes. lo six (t. in diameter, Exchange for
E6.3 lens. will (rude a pair
\V':uu S.W. receiver. Make trade offer. tix wit generator in excellent condi- Kaiak.
of 800 mutt tins tribes. 0 -25 II.'..
not being used, as this cable draws into Cl:rry
m
11.
/inure. 1322 Gillum St.. ion. F. McNabb. Green CIO'. Missouri. Weston. II -IOU
MIA.
Triplett.
Ft
100 ohms. Up to 14 Mc. power loss is l'Liladrinhla. Pa.
11 201111.
Avenue H. New York City.
WANTED ilIDEI'S M\\1' /1.3
StV.tI. .1N EILEN 7C -Ail RE- to 9 volumes. will pay cash. Carl M.
reasonable, and climatic conditions do not rebel.
SWAP--WESTINGHOUSE Ill) V.
IIn tolls
20 -4080 -1iu .Jensen. 211 East 2110 St.. Bronx N. Y. A.C. 2110 watt generator- 4 replacebring changes, as with flex or even some col!.,. Al condition with
for small 5 -meter
\\'ANTED-- -s'ASH OR TR.\UE
ment carbon brushes and blueprint.
Or small lull mfrs. soar
or
xl
For Speed key. Mac. n
open lines: and this cable is also com- Iranseeitrr.
tubes workingll
Barbells,
what
Slaurlren Duberoil. Lavaitrle.
ete. .0. Hellen. ILEA( No. 3. New
Need not be
condition
If
Quebec. Canto la.
paratively light.
eye perfect. Send list. have Iluplicates Brunswick. N. J.
\t'.
SCIENCE FICTION. TI:LE- for trade. M. Snavely. 1014 Cedar
In case references are not available for vision\NT
WANT l'ODF. MACHINE WITH
magazines. Id and new want St.. Elkhart. Ind.
tapes. Have Darold tuba
hecker,
old television stun, test equipment.
a Reinartz loop, the following informaCANADIANS-WILL TRADE S'VI' Ranger signal g aerator and Triplett
lane radio nuagazIncs. 1:123 l'g'ular es Radio
& Television mega es radio teeters. Donald II. Marcotte. Garvin.
tion is given :-56 Mc., 8 ft. 'A in. of wire, Mechanics. 1927 toilet ilion magazine
Minnesota.
for
cashing
parts
machine
engine
gas
30 inches diameter, loops spaced 3 in.; 28 valued at $5.Im. diagrams, cowboy or 250 toll 50 null motor generator.
WANTED
STAMPS,
Whig.
Riot
lialIrk. Norwich. J. O. S. Hunter. Kensington. P. E.
rids and hook notches front POSTAL
Mc., 16 ft.
in. wire, 60 inches diameter, Kan..
all forIsland.
eign countries. Hate such to exchange
loops spaced 3 in. Loop ends approximately
HAVE 51ST OF LIONEL ST.\NI1\c'.\NTED ItC.t 933 ACORN TI'BE, from this end. Will also exchange
uni gauge trains tallied at approxl- have new Cardwell
variable cond. 15 Colorado tokens for other tokens. Ellis
1 in. apart.
mately $75.uit tt1'irh
would like to
^ Iianunariund 5 -prong Isolan- L. l'arr, 405
Ash Street. Trinidad.
for soue radio equipment or mmfd..
A narrow beam, in a direction away from trade
Colorado. U. S. A.
sockets. 2 R.F. chokes s
1111
testing apparatus. lark Iledlundh, 153- the
John Etaunvalo'.
17
Robert St., So.
HAVE 2 11.1'. Ot'TIBOAIti) Mll>TOIL
the open end of the loop for transmitting, 16 32 Ate.. Flushing. N. Y.
Paterson. N. J.
2 B. and L. microscopes. 3110 to 2.0011
INTEIIESTF:D IN SECURING .1
is given.
WANTED VARIABLE BEAT FEE diem.. I pr. I,ino-uhtrs n pwr..
1
411
I
.
-
1
,
l
s
b,
sSummit
1
o
,
"r
I
-
c
1
1
1
Master Tektites
Results
A month's test with a constant input of 7
watts has obtained an average report of S4
at 20 miles, with a hack coverage of S1
using a frequency of 57,488 kc. Short range
tests have given reports of S6.
BOOK REVIEW
NOSTRAND'S SCIENTIFIC ENCYCLOPEDIA.
pages, illustrated, cloth covers, size 8" s II"
1 21/2 ". Published
by D. Van Nostrend Co., New
York City,
Among the many subjects covered by leading
authorities. we find Aeronautics, Astronomy, Botany,
1234
Geology, Mathematics, Medicine, Navigation, etc.
Twenty -one leading scientific authorities wrote it.
All of the subjects are arranged alphabetically
and can be located quickly. Under "A," for example, we find such timely and important subjects as
airplane engines, airships, alcohols and avigation.
Under "B" appears, ably treated and illustrated
balloons, bees, bending moment, binomial formula, blast furnace, blind landing, blood (with
color charts), oil burners, etc. Under "C" important
topics covered include-cancer, catalysis chemical
compounds, coal, coke and colloids. Linder "D"
appears -definite integral, derricks, digitalis, dyes,
etc. In the "E" section we find eclipses, Einstein
theory, electrical topics (such as dynamos, motors
and controlling systems), electro- magnets, esters,
eugenics and evolution.
The
variety of topics included is beyond
the scope of this review column, but we might
mention a few more subjects just to give the reader
some idea of the vast scope of this remarkable
volume. Among others we note-fish, fuels, fungi,
harmonic analysis, helium, hydraulic turbine, interferometers, invertebrate paleontology, Lentz's law,
leukemia, ultra short wave, uremia, vectors, X-rays,
-
for April,
1939
un
-80-
.
VAN
telephony, television, tonsillitis, etc., etc.
1
with tape. Gustave
audio oscillator, will pay cash. Schick dry shaver. Will swap. l'eter
Mlnndrush, 9918 Lander Ave.. Detroit. quency
Give make, urodel, ennditlon and price Lambert, 27 Vernon Street. WorcesMich.
in first letter. Gardner Radio Service ter. Mass.
TRADE: 32 VOLT TO 230 V. 2089 1. St.. San Diego, California.
M'. \Illarmodea,'
power supply. Silvettone 7-tube battery
TRADE: EILEN EX -14 -AH 6. Blues on
Tt)Brandes
set. late model. comolete 32 volt At- tube
receiver. Cost $24.40 new. "Superior" headphones. type 30 tube.
water Kent radin 7 tube. crystal mike. Coils T.R.F.
for 20- 10
100 --BC hands. Will strap for electric barer or wristrb
mike. for? C. .1. Gates, 239 ISUIIt -In speaker.
watch. MI. Konen, 48 Edwards St..
What
have
you?
All
Main St.. Jonesboro. .\tk.
letters ans. VL'9TME- 2901 N, Kilbourn t'atrhngne. N. Y.
TRADE: 250 F:Xt'ELLENT AIR - Ave'.. Chicago. Illinois.
1V'.LNTE14 RADIO PARTS. PICEFplane pictures. Army. Navy and forWANTED: C. S. ST.t'IPS. 111(:11 rwably headphows n
r. omdensers.
eign planes. what have .yon in radio values. commemoratives.
um. 209 U. S. and foreign stamps.
preranmis
or
don't
want
IITII
Y
Raymond Berubo. slogan meters. Will trade magazines Over half are ennrmeumrat Ives. Two
you
24 Hawley St.. Lawrence. Mass.
tiffs
Including Iladio- Craft. out Issues of are
Carl O.
NEEDED VERY BADLY. MODl'- Electrical Experimenter. Esquire. ate. Hicks. Roulr
Lave, ne.hOkla.
lator or speech a up., stets. any kind Send for free list. Charles l 'henowet h.
WANTED: NATION:AL FR7 WITH
of 'unifier wanted. \nythi ng swifter 1218 S. Blanchard St.. Findlay. Ohio. coils and parer supply. or cher
good
or recording n cded. Swap ()SI.. S1V-I.
communication receiver. will pay cash
Sw'AP- TOOLS, l 'AMIERA,
cards. OSI. 101i'á. Send details, Ray E. crimping machine. mourned CROWN
Have several Interesting
owl, jig or trade.
Murphy. 7311 Georgetown Rd Bethes- aw, stereotype caster. noelties.
items
to
trade.
II.
S.
Lair,
Vineyard
small
da. Maitland.
printing press. etc. \l'snt- ndcrosconr Haven. Mass.
BATTERY ('ILURGER, I -20. HOYT typewriter. postal scales. .22 cal rifle.
RAVE 7 WATT AMP. 4 TUBE.
meter battery tester 38 h.p Sage
cary tool. Will exebange lists. Albert trade for good lathe.
goal phono
blunting knife, sheath. No. f pocket O. Rimer. Rimer. Penna.
piekup-motor.ami- turntable. or small
Kodak. lr11aal. Popular Mech.. Popular
gasoline engine Trade tubes. R.F.C.
10 11.1'.
Science, National Geographic macs. motor. will LO,'KWOOD OUTBOARD coils and ant. eoils. El ihre Thompson.
for mtorryrle. hort
Want gelai SW receiver. elect. M. 'are receiverswap
or what have You. w' Ii Raz 451. Kosrhsko. Miss.
Gohr. Box 64. Willow Springs, Ill.
Cotter, 31 ('earl St.. Springfleld. Mass.
HAVE Fit 1311. MIKE. SW4 WITH
It('A - VICTOR
940
RADIO HAVE NEW $150 PORTABLE l'Of- 11 colts to 18 meters. handset, 0 -5
chassis. tuner. power park. dynamic
rn marhi ne for new or nearly new Weston 3 volt-meter. also 3 P.I -4
speaker and loon. Ideal fnr experi- U,, i irrafter or
tubes. a real antique. So wat ea
menters nr loud sneaker system. Instru- what have yon? National receiver. or w'1LU1. Roxbury (191. Mass.
?
Gerald IL \\'mit
t
ment
cost
for 8e:1 Randolph. Waterloo.
$t000.On. Exchange
lava.
WANTED AN ULTRA STRATI/standard make
over outfit.
rifles.
sphere
'10"
complete
with
all
HAVE OVER 422200 WORTH OF
coils.
P.O. Box 124. Somerset. KY.
be In perfect shape. alzo want
1111,11 grade s .w. receiver parts and kits must
WANTED- NATIONAL, l'w'2 TUN- to exchange
short wave sets and transceivers. Steve
for stamps or receiver
h
Ina hilt. Pie mIefd, per section. com- as Sky Champion
410 Novela. Jr.. Maaveagna. III.
or
Howard
plete with gear hex and dial. Aladdin .1, Kasperski. 34 Albern Ave.,
CANADIANS- HAVE 2.01111 RARE
OceanIrs types S- 2212:1. S-224211 only. side. N. Y.
British Colonies. Dominions. stamps
Have IInstructograph with tapes. oseil
SWAP 300 INDIAN HEAD PEN - mounted, including Coronations. Collectaira like new Andrew ILIUM. 3315
nie,. half cents. two- and three -rent tion costing SID). 80 Stamps MagaW. 31st St. Cleveland. Ohio.
pleas, old nickels. half dimes. Bliley zines. Rankin Favorite album. for
WANTED: COILS FOR PHOT vial. D.B. mike for portable batten' good transmitter. 50 Watts, or parts.
Super Wasp battery type s.w. reeve.. receiver
or
turntable. Herbert w'agntan. U Lauder. Toronto.
phonograph
also Riders manuals. It Elim lnalora 1V2GPG. 139 So. Day St.. Orange.
TRADE
FOLLOWING
PIIOTOand cote
write. Archibald
tapes.
graphic articles -8x10 plate Kodak
Rursey. Burlington. Newfoundland.
with several old lenses: Fah DerbyS \V'AP ARGT'S CANDID CAMERA, movie projector anld filmmss. violin, phono F:2.5 new. with case: enlarging lens
F:3.5; t'nivex male lens F:3.5; radio
or G.E. 1/. h.p. electric motor. heavy oscillator. mike. test equipment. align
duty induction type. fnr model airplane Ins tools. radio hooks and ,nagazines. parts. For? Gerard Lacombe. Box 513.
mane or repeating rifle. Ra > Cecil. tootle ramera, films. or. Harry Parker, Madawaska. Maine.
Winters Lane, Col Springs. Kentucky. Sylla. N. C.
(Continued on page 764)
.
t
Please say you saw it in
RADIO
&
TELEVISION
www.americanradiohistory.com
763
s-w
BARTER and EXCHANGE FREE ADS (continued)
HAVE B SUPPLY AND NUl1ERHAVE NE,, (RIDERS VOLS. 2. 4.
moud. ous
other radio parts to swap for
Mateo signal gen. All a
rad photographic equipment. All letters
1
Il8g, Jewell analyzer. mod. 911.Da
v
for answered quickly and cheerfully. Billy
ports
tube testers, short
what? .los. Itakutis..791 (tannipiac Criswell, 57 pinard Street, Lockport,
New York.
Ave.. New haven. Conn.
MOVIE
HAVE MOVIE AND CANDID
MM
200W -10
11.tt'E
movie
cameras. filters. mint t'. S. comm.
ft.
with
1.000
IAUOCi
Projector
g min movie stamp. prerancels. electric shaver. etc.
filins .aloe $59.00.
quipment, or what have hlyou. J. Want good reties camera. enlarger.
Winkler. 662 Bergen Ave.. Clifton, photographic items. or? Michael Clan .
N.
SWAP
erle,
39
JAN .T1'E
C
dition.
ROTARY
CON -
to 110 AC. for Sky
In good condy$35. Also have 12
D.
typewriter.
or
Buddy
Cost
namic spkr., for crystal. parts. Jack
Spencer. 513 W. La. ate.. Ruston. La.
/LIVE 1/6 1Ll'. A.C. MOTOR, 2
Magie Eye tubes. Will exchange or buy
old coins dated before 1900. I'leaso
send exchange list or price In first
letter.
oltA; Stanley, Box 183.
Winchendon. Mass.
TELEWANT
MICROSCOPE.
scope. chemistry outfit. electrical engineering course. large dictionary or
encyclopedia set. Have audio amplifier. speakers, power packs. 4 radios
and bundles of tubes 2loi radio parts.
('laude Carpenter. Sweet Springs.
SWAPPERS!
Ihing under the
Roods
what
SWAP EVEItYMostly hobby
1
sun.
have you? anStamjpoitbrings X11tfor
South
Roswell,
C'lmnelsot,
Dakota. U. S. A.
WILL EX. FLANGE: R.C.A. MAGnetic speaker. trickle charger. Tungar
batten' charger. old typewriter; for
Ieating equipment. l'refer good tube
tester. Write. .1. Marsh. 111 Van Liew
Ave.. Mitlnar'n. N. J.
HAVE) NO. 4 ERECTOR, LINO.
equip.. barks.
lab.
carving tools,
kpeaker,
pin collection. tent.
nife, etc. George Fried, 1.1)4 Weeks
Virgil
shat
Describe drill and
wap fors drill.
swap
you need. Merman Yellin. 331 New
lote Ave.. Brooklyn. N. Y.
WANT 436 KC Alit TUNED 1.F.
transformers. 436 KC I.F. crystal.
Meissner slide rule. dial. rolls, and
tuning condenser. Have radio parts.
tennis racquet. cantera. cash. Harry
BC parts. power pack and new tubes.
Want Stromberg- Carlson No. 69 SW
converter or fishing teek:e. H. D.
Statueh Lowell. N. C.
l'
Coand
air
nails
Mervyn
preferred.
lhotm. 18 Grove ('lace,
dccc). Northern Irelnal.
L.
London
PK4KS. PK4CT, and PK4HW.
RECEIVER.
43
To get clown to business, we have reports from
the following sections of the world:
Wells. Jack
Alabama
pr. rolls. freq. meter. ztals. trans.,
vernier dials. tubes. misc. Everything
for ham Smiller. Want stamps or
camera. All letters answered. Jack
Clark. 4 Gibson St.. Natrona. Pa.
3
.
IRELAND CALLING. WILL EX- barometer. F4.1
change stamps. cigarette cards, or post yrs. Pop. Sci..
cards for stamps only. British colonials Chem. Soc. I.eo
Normandol Court, 109 Kerk Street, Johannesburg,
South Africa.
From February 11 to about March 14, \V2IWT
will be en route to the island of Sumatra on an
expedition. During the time he is gone. he will
maintain communication with W4ULH of Goulds,
Florida. He will also be in communication with
Dinarkus, 800 Sixth St.. heading. Pa.
HAVE FISHING TACKLE, ItIFLES.
radio mage., short wave radio parts.
HAVE NATIONAL
'f. VI'K camera. 3
yrs. Journal Amer.
Colorado
Connecticut
France
Georgia
Ave.. Rutland. Vermont.
WILL TRADE NEATLY CON transmitter.
50 watt ('SV'
6L60 xtal and 10 final. for medium
such
power transmitting parts
Illinois
strueted
power supply. tubes, or what have
you? WSRXW. 2119 -12 Street. Moline.
Illinois.
BEST TRADE OFFER TAKES 2"
cycle power transformers. 0 volt speakers OST class It output transformer.
33, 2A3. 81 tubes. 110 volt. 700 watt.
60 cycle generator. band suits) coil
(luck. 43
assembly. condenser. D.
Hagen Ave.. N. Tonawanda. N. Y.
4
HAVE OLD 9 -TUBE l'HILCO B.C.
sensitivity. needs
.1. Jennings. 73 Hume receiver. goal tone.
Ave.. Medford. (lass.
minor repair; trade for typewriter.
Ill.
AM A BEGINNER IN RADIO. Ivan Rice. Meredosia.
WANTED: 5 METER C.W. TRANS
Would like to swap parts and corre-
B. Hume. tt'IK III. 51 Atlantic
BATTERY K.
Ave.. Boothbav II vrhor. Maine.
broadcast receiver. Want lathe. elerBABY
E:.t S T ll A N
TRADE)
h.p. motor.
trie drill or drill press.
camera 81.00. t'nivex motel A
A.C. short wave set or what bave you? Brownie
50e. Want canera that takes
Carroll P. Clark. Gossville, New ameraexposures.
snapshots. Will add
tinte
Hampshire.
If vour camera costs a little
MOVIE books
HAN VICTOR 16
more. Alexander Polstepny. 217 l'Ine
approx.
81011.00.
Wprojector. silent. cost
St.. Phot.. Penna.
ill trade for a Hallicrafter Sky
WANTED A G(R/1) SHORT WAVE
r'bampion. fluet be in good condi-
.
llll
C.C.C.. receiver. Have three months' old Remington portable with case. Also cash
1
I.
if
in.
TRADE KELSEY 5.g PRESS, Franklin Street
II Oitst se
Let
of
type.
new
8
rases
pedal operated.
11EILICIL\F°l'ER
HA
WANTED:
rollers. 2 new type 10 National Lnlon
lo aviation and 29
lime
heavy duty tubes. Want low power ceiver.
aboard motor. Popular Science magazines. Dick Satter.
ten meter phone or
Dayton. Ohio.
cour.
Vo'usi'.
.t,
306
Minn.
II. Cary, W'9TOF. Eagle I Ake
BEST TIt )15E OFF'I:li TAKES
YOUR DUCK HUNTING STAMP .Jewell
all glass
Cheeks
tester.
tube
purple
postage
is worth ten unused
radio equipment.
stamps to me. if in good condition. limbes. Traite for 0539 Gaviota Ave.,
Stamps, rovers. postais. seals. radio Columbus Emma.
parts. to swap for same. Drop a Van Nuys. Calif.
today. Mervyn Reynolds. JefHAVE 133 ILU:S., ,íE110 DIGEST.
Maine.
1mai51
ferson.
Popular Aviation. tir Trails. Flying
Popular Mech.. Ox hlaseope.
WILL SWAP CAt11NErED MA- Aces and from
Majestic 70. Want s.e.
heath. speaker. 2 dynamic 5 in. speak- all parts
Lukas. 87
ers. 2 tube I'hilmore all wave re- A.C. receiver or. Joseph
S. Bemire St.. Jonson City. N. Y.
A.
Send list for mina
razanskos. 105 Elizabeth St.. Athol,
BIver.
SWAIN STAMP S. PRINTING
Mass.
equipment, printing. fiction magazines.
{CANTED: ARGUS F_NLtIIOF.R and radio parts for communications
sr? have rifle- radio tubes and parts. receiver. radio parts. mechanic magatamV catalog. back Issues of S.W. zines or what have you? Earle Ham&T.. also many other assorted books mond. Apion. MO,.
and magazines. Robert E. Lloyd. Box
SWAP: 1V, H.P. FAIRBANKS9t. Portsmouth.
Morse gas engine like news, battery
344,
i
.
1
1
.
REGULAR
LINOTYPE
KEY - charier AI
shape. ta
lI.P. "B line"
110\' electric motor. radio magazines.
Good for learning to operate.
exchange for receiver or what good A eliminator for radio parts,
Walter Blumer
have you? George Mraz. 015 7th Ave.. especially
tt
x m 11Img.
112.
Williamsport. Pa.
hoard.
Will
SWAP COMPLETE: SET TEACH-
ern and Pupils Encyclopedia. like new.
value $28. for good buttery operated
receiver. Ernest Verity, Box
20. floodwater. Sask.. Can.
HAVE GE 12.00 VOLT CT 22
Buescher
transformer.
milliampere
It Mat soprano saxophone. large stamp
nunc C. S. commemoracollection.
tives. Want transmitting equipment.
test instruments. nl ufarenred receiver.
crystal microphone. a wV,FER. 1403 East
Washington. Boise. Idaho.
amateur
TRADE-NBA KODAK BANTAM.
827.50 value with anastigmat f4.3 lens.
1/2011 S.P. lens and camera In pert.
rond.
Will trade for Si'.' receiver of
similar
Raymond Mueller, 33
Fond du Lae. Wisconsin.
calme.
Seventh S'..
¡
WANTED TO SWAP "CORTEX"
HI'
Underwood typewriter for '4 in
gasoline engine or goal batter' radin.
Typewriter complete with new ribbon
and carrying ease. Thomas H. Brook.
Hal eyvl l e. Alabama.
I
WANT ENLARGER. DEVELOPING
tank. pH ute-r, exposure meter, and
wogs Input and 150 volts output. other photographie equip Will trade
Zenith wind charger. Maytag gasoline printing of stationery. etc.. new earphones. phone -pickup. 10 watt amplimotor. 32 volt lite plant. Sonora
n[ed Riders fier. power supply. Oafs printed or
ta
Wilier
Gottfried ^ash. Bill Pearce. P.O. Box 671,
Gernsback
or
II.tVE EMERSON DYNAMOTOR,
Streckert. Chilton. Wisc.
764
Kansas
Louisiana
Maine
Nebraska
New Jersey
New York
North Carolina
Ohio
Oregon
Pennsylvania
South Carolina
South Africa
-
.hr
2 -VOLT
tion. 1. A. Dare. Co.
Yellowstone l'ark. Wyo.
Clarke. Stanley
Wallen, Dan T.
Kemp, Howard
Le Rasle, Charles
Patterson. C. R. ( "Pat ")
Carling, Len M.
Hegler, Burns E.
Wynne, Maurice
Barker, Elwyn
Noyes, William Dean
Fitzpatrick, John
Herzog. W. F.
Fuller, Charles H.
Yours truly
Oglesby, William W., Jr.
Gallagher, L. F.
Truentan, Elwood C.
Hartzell, Clarence
Halliday, Ray
\-ersfeld, Joint F.
\ \'esanan, Oscar
Parker. Robert
Lang, Ernest W.
Canada
I want Ralston cale records or what
have you. Robert C. Dole. 10 Clinton
Klamath Falls. Ore.
Rudolph Thoma.
Brooklyn. N. Y.
1720
Putnam
Au e..
HAVE TRIPLET(' SIGNAL GENrator, Model 1230. Gated rond., but
less batteries. Will trade for "hoc"
H.
Dubois,
Bruns.
Idaho.
G.
(CC
4607
150 -98.
SWAP-ABSOLUTELY ALL NE
-
parts for six tube super
Meissner IF's. Hammarlund's, tubes,
power supply. speaker: for Vnllenda.
essary
Kayak flore by
Gold', enlarger.
letter If interested. Hubert Siud,
3703 Belmont. Chicago. 11 Imo's.
WILL EXCI (ANGE 90LESSON
Spanish guitar course for SW receiver
or
or what have you. Charles A. Nuss.
812 Locust St.. Williamsport. l'a.
TRADE
FOR
GOOD
BATTERY
all wave radio 4 -6 tubes. Mar Practice set. 20 tubes. camera. 2 headsets
W. E., Trimm. 39 ARRL Handbook.
2 crystal sets. world globe. Hover. Bo:
55..
Leman Grove. California.
SWAP-125 VV'.TT RIG WITH
2"
meter
cycle supplies for good
transmitter and receiver. 25 watt P.A.
69
b
Simeoe. Cook
ntario V Canada.
syst
Box 419.
SVm'AI': THItEE POSTMARKS FOR
bag sent me, one
Planters
peanut
each
perd) stamp brings one hune
sired, send return postage. all hunting
Stamps must be on original paper.
tanley W'rlelu. Howard. S. Dak.
WILL SWAP AGFA D6 CAMERA.
6 jewel wrist watch. 50 foreign coins.
foreign stamps and currency. oil paint
set, magazines. for radio parts and
equipment. S. Bederman. 1295 Sheridan Are.. Bronx. N. Y.
2 GOOD Ht('KOCK HIGH FEEgummy mllliammeters. 0.1000, 0 -4000,
mounted; Shure 22N microphone (poor
condition); Noiseless portable typewriter like new (with case). Want
supplies.
or photographic
cameras
West
End
Eiehberg.
Robert
752
Avenue. New York City.
WANTED: SKY CHAMPION. SIG sal generator. beat frequency oscillator.
oscillograph. Trade and cash balance.
Must be in excellent condition. Write
directly for arrangement. EL S. Loh.
tl Mellen Street. Cambridge. Mass.
SWAP PAIR T -20'S. 50 WATT
class B I ransfpmers. double Mutton
mike and stand. pair 600 volt 200 mill
UTC with 4 filament windings for 3000
volt condenser or transmitter pans.
VVSGIT. Rio Hondo. Texas.
(Continued on opposite page)
Please say you saw
it
in
RADIO
&
TELEVISION
.
Fuller, Lester
Henderson, Bill
Arizona
Arkansas
I (LAVE 10' UT.tII SPEAKER. 3'
RCA speaker with output transformers.
WANTED: SWITCH BAND SHORT spond
beginners.
.h
()elver. Trade home chemical laboratory
and long wave receiver. I have 1).10 Berkshire. Its.
.
nsisling of approximately 300 'ifor rill pay wcash. Not over t tubes.
ferent chemicals in vials. Jars. Also
MM)IF
16.11111
100
l'SEI'
WANTED.
Prefer metal ones. Chas. ell. Miller.
includes
glassware. several books of
11SL
condenser. Will
]rural Sta., volt transmitting
elicit
Pinewood.
$20.
Box 4143.
with YL's in foreign countries only. chemical analysis. Onlflt
Minns. Fla.
HAVE 6- TURF:.
Hamyl bands
CONDITIONS during the past month have
not been any too good, although some very
fine business DX has been heard at times. The Europeans have been coming in very well. and about
two hundred were reported by our observers in
January. Conditions on the ten-meter band have
been much better than ever before this season.
and about half of the stations were reported on
this band. Twenty meters has improved somewhat
from the previous month, and is now staying open
until a much later hour at night. At present it
is open until around 2:00 a.m.
We have learned that ZT6P has changed his
call to ZS6CK: his QRA is: E. P. Alxlo, 314
City. Mich.
WANT ELECTRIC DRILL. HAVEZ
numerous transmitting and receiving
luxe or similar set:
Jy
League
Edited by Eimer R. Fuller
WANTED A 61.611 ll(ODL'L. AND
speech amp. O1.6 tubes also. Condenser
and mike. l'ay cash or swap. Ilar
Rozek, 712 So. Farragut St., Bay
SWAT'-FOIL USED DO-ALL DE-a G.E. Tungar
charger. (larges up to 16 batteries.
INSTItI'e'rot ;RAI'N Olt OTHER (Swell for serviceman.) Has extra bulb,
A-1 condition: list free. Don
crate machine wanted or set tester. all
Trade 180V genemotor. model A100 Yoram. Beltsville. Ohio.
Utah trynamic speaker with power supTWO 12 Ga. DOUBLE
SWAP:
John \(alder,
radio
ply or
hammer style. Stevens 410 Ra. double
other Idaho. parts.
hammerless shot guns. Eastman 4 z 5
HAVE; $260.00 BUSINESS COR- autographic kaiak. registered A.K.C.
respondence course. ten tube battery rocker spaniel pups. Started, trained
radio and many radio parts. Swap beagles. Wanted: Koulaks. rifles. Gust
for test equipment. meters. Riders Spink, Route 7.0. 3'uskegom. Mich.
Emanuals. National SW3 or preselector.
WANTED: STItAYBEItltY'S LtTS. Barnett. Smolt Roston. Va.
est regular radio course. Have to trade
TRADE 2 LIONEL STANDARD automatic raie machine and code
trains and equipment worth over $100. course, all -wave amateur set, :milting
for good .22 repealing ride and hot - parts, milt 's. meters. etc. For list
gun or late Sk'rider or Howard
write to: S .1. Nicewicz. 79 Church
Ray St.. Broad Brack. Conn.
a-elver. etc. Also have stamps.
Borers. 071 E. 92 St., Cleveland.
WANTED: TEST EQUIPMENT,
Ohio.
auto radio. have 57 -1112A5-80 amKC
WANTED: CHEAP ELECTRIC Motor with turntable. suitable for use crystal. 353IM L De \rjkrcamera. C.
with pick -up. Tell R.P.M.. ge. make Fortier. 4 Clinton St.. Potsdam. N. Y.
ill USL 10ñ')-. Don WANTED RIDER'S 3IANU.t1S.
and price. I
I'ettilohn, 2117 East Mifflin St..
C.11. tube. double extension plate
Madison. VVisromin.
C.R. tube. excellent
tuera. Have
M lexouri.
On the
H.P. generator D.C. Packard electric
razor. 6 volt model. Hammond type writer. For 16 mm films. ('lare E.
Ernst, 1107 Root St.. Flint. MA).
Ave.. Crow.. R. I.
froeco, 604 Union
.1.
WILL SWAP ONE ELGIN 3 TUBE
receiver and coils complete for
Iller parts, meters or good mike.
All mall answered. Pauline White.
Pittsrille. Maryland.
WILL EXCHANGE 32 VOI.T ONE
S.W.
Utah
\\ a.shington
Beginning with this issue, another new plan for
listing stations reported heard by our observers
of this new method.
is thought that it will be much more useful to
readers are interthat
our readers. It is believed
ested more in :there a station is bring heard than
in who is hearing it. Therefore, instead of placing
the name of the observer after the station reported,
the name of the section of the world which the.
is being inaugurated. By use
it
observer represents will be printed.
From Asia, the following stations have been
retorted. This is the largest number of Asiatics
to be reported this season.
Il 'here Heard
R S
Freq.
Coll
6
Canada
5
14.3
XZ2JII
South Af14.067 4.5 5-8 Penna..
XZ2DY
rica. Ohio
9
South Africa
14.
5
XZ2EX
Ohio
3
5
14.06
XUBAM
France
6
5
14.13
XUSET
3
5
Ohio
14.3
YL'2Df
France
6
5
14.265
VL'2LY
France, South Af9
5
14.19
V U2FU
VL'2CQ
VU2BU
ZC6A:\
ZC6AE
ZC6EC
YI_B:1
\'S1 Ai
VS2AS
V S6A S
VS7RA
VS7RF
14.12
J2AK
VS7GJ
L'81 B
5
9
14.415
5
6
14.1
5
5
14.36
14.0
14.08
5
8
5
7
14.
5
14.13
14.28
5
5
8
9
6
14.1
4
5
14.04
5
14.
5
14.445
5
9
9
6
14.
rica
France. Ala.. Penna,
France
France
France
France
France
France
South Africa
France
France
Ohio
France
South Africa
France
Africans have fallen off some since last month.
but several are being heard in the eastern United
States, and are very consistent in France.
ZS1BL
ZSIT
ZS1:\X
ZS1B
ZS2X
ZS2AZ
ZS2AF
ZS2N
ZS3F
ZS4H
ZS5AW
14.03
14.09
14.102
14.08
14.01
14.04
14.110
5
8
5
5
7
8
4
7
5
8 -9
28.215
3
5
14.1
14.07
14.06
28.1
5
3
4 -5
7 -8
5
5
9
7 -8
5
7
France
France
Penna.
Ohio
Canada
Canada.
France
France
I Ii.
France, Penna.
Penna.
Canada. Penna.
Canada
RADIO
&
TELEVISION
Call
ZS5T
ZS5CL
ZS6A
ZS6BR
ZS6S
ZS6X
ZS6AJ
ZS6D W
ZS6AJ
ZS6W
ZS6DK
ZD2H
ZEIJG
ZEI JE
ZEIJX
CN8AW
Freq.
R S
14.1
5
28.0
14.085
5
8
8
3
7
14.015 3.4 6
14.047 4 6
14.120 5
8
14.005
3
6
14.085 4
8
14.03 4-5 6 -8
28.03
14.04
28.26
4
14.01
14.065
14.3
14.045
5
5
S
5
7
7
5
5
6
9
6
5
8
Where Heard
N.
France
France
France
France
14.0
France
vQQ2HC
VQ3LJP
5
5
Ala.
France
Penna.
Ohio
France
France
France,
rica
South
Af-
For the benefit of the amateurs in our own
country, the following have been heard in foreign
countries mostly across the big ponds. These are
all in North America.
TG9BA
TG9AA
K4FAC
KSAF
K7FBE
K7FST
CO2EG
CO2 W M
CO2LY
CO6OM
CO7CX
VP1BA
VP6YB
VP7NS
VP9L
HI6
HI7
NY2AE
TI2AV
VOIY
VE2AK
V E4 BF
V E4 SS
WI AFJ
WIANA
WI BIM
WICM)
WIDIK
W1FVO
W1('US
W1HJK
WIIGD
W11YE
WIKUD
W1KRW
W1LMB
W1LNE
WIWV
WIBLU
w1AXA
WIAJZ
WI
B TZ
WIID
W2111)1
W2I XY
W2JKQ
W27P
W2ALK
W2FGB
W2HJU
W2JMC
W2JXZ
W2 HR
W2CLK
W3 RSO
W3DKY
W3FN
W3CHE
W3FOU
W3HQV
W3UX
W4RC
W4 DU
W4BIV
W4RMR
W4DLH
W4AAU
W4AEI
W4DCO
W4DWX
W4EDD
W4 M V
W5EI.W
W5GDU
WSDNY
14.285
14.060
28.55
14.13
14.25
14.25
14.2
14.07
5
14.1
S
28.4
28.3
5
5
14.08
5
5
7
8
14.1
5
8
5
9
5
8
5
5
5
5
8
9
8
9
4
6
3
5
5
5
- -
14.
14.37
14.160
14.
28.4
14.2
14.
14.17
28.15
28.3
28.5
28.7
29.0
28.15
29.25
28.84
28.55
28.265
29.4
29.12
28.65
28.54
29.45
28.68
28.94
29.3
-
8
6
7
5
7
8
9
4
7
- -
5 8 -9
5
9
-5 8
- 5
5
9
9
- -
8-9
5
9
5
5
5
14.2
14.175
14.185
14.24
14.225
14.17
8
8
5
8
5 6 -8
3
6
5
7
8
5
5
5
5
8
6 -7
8
4
8
6
5
7
5
5
5
28.725
5
7
8
7
8
- -
28.5
5
28.7
29.3
28.9
- -
8
5
9
29.11
29.15
14.
5
5
9
8
4 6-7
-
14.24
S
6
5
28.6
29.115
29.0
5
7
7
9
S
14.2
- 5 8.9
- -
14.23
5
29.1
28.935
29.0
28.7
29.445
14.205
5
8
7
5
5
9
9
5
5
5
7
8
8
4
7
5
9
5
8
4
6
Canada
Canada
Canada
Canada. Ore.
France
France
France
France
Canada
Canada
Canada
South Africa
Canada
Canada
France
France
France
Canada
France
France
France
France
France
France
France
France
France
France
France
France
France
France
France
France
France
France
France
France
France
France
France
France
for April. 1939
will
will
send you
any
Garcia. S. Trinidad
tuba.
SWL'S. XYI. S,
de
U
and OM. Send me fir rda and I
send
mine. Q1íÁ: Arnold
Shafer. 14810 Pepper Ave.. Cleveland. Ohio, l' e \ 73's. I QSI, 100' ;.
COME S VL'EIt$ AND GET YOUittelf an Idaho card. I QSL 100%. Will
answer ail cards. OltA is LaVere
Herbst. General Delivery. Blackfoot.
Idaho.
ATTENTION SWL'S. FSII'ECI.ALLY
IL's, don't be shy. Lets hear
I USL 100% with anyone.
anywhere. My QRA is Stephen Mecseri,
34th St.. John l'1.. Stamford, Conn.,
U. S. A.
SWL AN1W ER
WE
swap SWL cards.
QSL 1A00
QRA
Marvin and Nathan Greenberg, 444
East 32nd St.. Paterson. N. J.
you
from you.
HE.
WI.
'
1
ea
change
1
1
.
'
France
South Africa
South Africa
France
France
France
France
Africa
Africa
Africa
Africa
I
1
NI
1401
St.,
N.W.,
Washington.
Brighton, 7, Sussex. England.
ATTENTION
31 S
SWL'S.
\t'ill swap (1SLs.II Ashack
fotos. with
isatt Armand any OM's, IL's, XYL's
L'e.
Lee. N. H.
Also pleased to try skeds, 2031.SW40M,
ATTENTION SWLS IN U.
L
s
foreign
S.
AND
-
WANT AI)\'ANCED
CANDLER IQSL 100%.
course and associated
Candler Lebeau. It. E'.i i. No. 1.
touch typing
irse. Must be complete
ATTENTION ALL Soli: S, W'114, BUSt. C.W. only. limns about it?
anti in good condition. Have som
radio parts m will pay cash if price le exchange correspondence and postcard VE19t', Summerside, P.E. Island,
Canada.
right. Harry r (lreutich, Republic, Ohio. views with anyody
OR
Pltaerr, 62nPell) St.. City
SWL'S IN THE UNITED STATES
TRADE HIGH QUALITY 5 METER. Island. John
New York. U. S. A.
and foreign countries. 1 exchange SWL
10 watt transreceiver. 5 meter transTO ALL SWL'S IN THE. U.S.A. cards 100%. Also radio parts to trade.
ceiver, pressure gauges. For quality
and
foreign
countries. would like to GILA: Donald D. Warnock, Converse.
test equipment or H.M.S. Pinafore
records or album. S. Andrewskl. 11 exchange my SWL. card for ne
f Indiana, U. S. A.
ours. also swap "shack" fotos. o I
linratio St.. Newark. N. J.
ATTENTION DXERS
WOULD
QSL 100%. Howard Perkins, 14811 Ilke
to exchange notes on reception,
WILL SWAP TWO 350 31MF. Pepper Avenue. Cleveland,
Ohio. receiving equipment. etc. I answer
condensers with dials. one LA, four
10055.
Also
exchange
OIA tubes in perfect condition for
S\\T.
ATTENTION SWL'S IN CANADA. Mario Catlne, 2143 Central Ave., cards.
e 11,4,
two '30 tubes. three -circuit
Ashtuner to match a 350 mmf. condenser. U. S. A, and all foreign countries I land, Ky.. I'. S. A.
would like to exchange SWL rants
Norman Minks. Terrehonne, Oregon.
WILL
with you. Will positively answer all SWL
cardsLanLietters0with (all SW11,
WANTED
RECORDING OF
rots received with mine. .lames W.
and UXers all over the world, Albert
"Stardust." 456 K.C. I.F. stns and Newman.
45 Sixth St,. New Toronto. Pickering.
Jr.. West Medway. Mass..
to join U. S. and foreign short-wave
Canada.
V. S. A.
clubs.
I QSL 100'$. Paul
Bahr,
Marion. Indiana. U. S. A.
I WOULD LIKE TO EXCHANGE
MILL EXCHANGE Soli. CARDS
cards with SWL's
Imams all over with any /MIL or Ham in U. S. and
WILL
ELECTRICAL, IORTA- the world. I promiseand
to QSL as soon as foreign countries. Also swap stamps
ble and
itchbusrd meters or instru- I get tir card.
Larry
Kaczmarczyk 100,%. All cards will be answered with
ntents. Edward L. Boardman. 428 E. 511 West Pine St.. Mahan}
City. my card. Rober Yheuln, 122'2 W.
13th St., ;,:ew York City.
l'a., U. S. A.
Thompson St., Phila., Pa., U. S. A.
code
7
South Africa
8
France
(Continued on page 767)
28.6
5
5
IL's
I
1
HAVE FIVE DOLLARS TO
laland. U. S. A.
spend on radio parts. What will you Jersey.
give me? Eugene Goldman. Co. 4600,
SWLS WILL EXCHANGE SWL'S
HI FELL AS AND IL'S. LETS
C.C.C.. Rupert, Idaho.
swap cards. 1 QSL 100%. You want with
HAVE A 7- TUBE. 7 -BAND BACO nine -1 need }'ours. QRA: Robert J. IlarryarCoeAleier. Ire Roosevelt 1Ave..
Super Clipper. Desire to trade in an Ellis, 3539 17th St.. San Francisco. Cranford. N. J.
goal enperhet., will pay difference Calif.
GE
A. I1. SleChiloch, 11.F.D. No. 4, MonWOULD LIKE TO EXCHANGE SWL cards with anyT
or IHam
roe City, Missouri.
card with SWL's or A.A.'s anywhere. U. S. or foreign countries. I will
EXCHANGE AN
F.N.U. Francis Leslie Qe4L 1005,. Leonard Meadows. 3855
ALL
WAVE; I (.1SI. 1110',;,.
T.R.F. live -tube receiver. complete. Leach. 28 Wellington Street, Glouces- Stanten Ave.. New Boston, Ohio.
Has received all continents. Let's hear tor. England.
ATTENTION SWL'S ALL OVER
your trade offers. It. Willey. 1705 E.
ATTENTION S VLS in U. S. A. the world.
will swap SWL. ards
Burnside St.. Portland. Oregon.
and foreign countries. I QSI. and ex- 1U0% with everyone.
3s. My QRA
Is
Paul Ankerman, 404 Lima St.,
WANTED-FOUR Olt FIVE TUILE change shack photos and postcards of
t wave receiver.
Have telescopy the N. Y. fair 1005) and answer Wapakoneta. Ohio. U. S. A.
lho\. stamps worth $75.00 and one Promptly. Oita: C. latent. 104 -41
ATTENTION
ONd
small motor. also science magazines. ltlSth St.. Richmond Bill. L. I.. N. Y.
newt
and wud like Ito exW hat
have you in exchange. Gavin
with you.
EXCHANGE CARDS WITH
QSL 100(;, QH,t
tardier, 825 Sibley St., Hammond. allSAILS.
countries. have attractive VK card. Norman E. Whitn, 76 Green St.,
Indiana.
Will definitely QSL. Also welcome cor- Greenwood- Mass.. U. S. A.
SWAP: MOTOROLA CAR RADIO espondenee from SW'1.s. If interested
ATTENTION ALL SWL'S IN
tubes. Weston 0 -7 voltmeter. 0 -1.1 local views also QS!. for sane. C. U.
and foreign countries. Would
mill iammeter. ham key, other radio Jariett, 26 Edith Street. Huretril1e. likeS. toA.exchange
SW1. cards with anyparts for double -barreled shotgun or N. S.W.. Australia.
one. All cards received answered 100%.
31 -30 or so rifle. or else. Nicholas
William
WILL
Thistle.
GLADLY EXCHANGE
7 Flint St., GreenDenono, 8148 102nd Ave.. Ozone Park. S\l -l. cards with
anyone
anywhere wood, Sties.
N. Y.
Carl Prince, Clifton. South Carolina.
I tVOCLD LIKE TO HEAR FRO31
RAN.IO UKE. GUITAR. ERECTOR l S. A.
Hams and SWL's anywhere. W'111
dimotor. auto safety lighter, sharp taller
SWL_. OF THE WORLD U. S A. cards, photos or view carda 100% swan
with
al. 2 tube
radio with amplifier.
merseas. l want to swap SWL. anyone. Stan Brus. 1441 Bell Avenue,
postmarks, approval stamps. block fours and
cards with all
QÌLA. Brat North Braddock. Penna.
with plate number. want duplicator. It. Anderson. Metropolis. you.
III.
HI, U HAMS Est SWLS.
Lewis, GrimlMllle. Ark.
SW'1V AND HAMS ANYWHERE es IL's. Send me ur QSL or OM'S
SWL.
HAVE 2- 5 AND 10 METER RE. in the world. wish to correspond with I QSL 100'; anywhere with my SWL.
SL
celvers using 6F5 -4;C5-25141 -2545. you. lour SWL. or QS'. appreciated. QRA:
rout u. 51,
W'ingfleld
Street.
Portsmouth.
also riC6,- 70- 43- 25'A.1 15-550 meter I will send you my SWL. OR
England.
F
receiver. Want a tube Howard. Ex- Hoffman. 1744 Wilmot Ave.. Chicago.
ATTENTION SWL'S ALL
III.. U. S. A.
change
test
the world. I will swap SWL OVER
ShelO n Ra lionClub, 202
q2n St.,
WOULD LIKE Tl) SWAP SWL. 100% with everyone. Sly ORAcarda
is
Brooklyn. N. Y.
cards with anyone. anywhere. I WI. Oscar Corwin. 703 S, Columbia St..
S\\':\l' R1tO
NI; 3511 AMA - 1901'. QUA: Harlan C. Pruett. 514 Frankfort. Ind.
teur receiver chassis. beat note oscil- Lineberger Street, Shelby, North CaroSWL CARDS SWAPPED WITH
lator. phone lack-stand by switch. per- lina.
anyone. Cnte
you
DX hounds.
fect condition. just overhauled, new
Stall me your ca
S \l'L FItO)I
IDAHO.
mine In return
tubes. 12' dynamic- speaker. {Want 1931 Wyoming, Delaware. NorthNEVADA. mall. ORA: NI. P. rd.Wynne.
Dakota.
210 Hector
Super Skyrider. Patterson PIt12- 1931. Louie Kucera, P.O. Box
Metairie Branch.
102. Apache. Ave.,
New OrT. Marks, 109 -I9 96th St.. Ozone Okla.
leans. La.
Park. L. I., N. Y.
I
EXCHANGE
SW'1. YARDS WITH
OVERSEAS
SWL'S
SWAP:
SEND ME UR
TItA IN
EQUIPMENT. the entire world. Send me your card card.
stamps. telescopes. microscopes, army and
mine In return. I correspond include ! Briighton Lvie s
binoculars: also have radio magazines. also. get
to any St\L
hear from all of you. Fat sending view M his
Wanted-any type of short wave re- Ziny, Let's
town
to this QRA.
S.
California. Chicago, R. T. Parsons, 14. Carlyle
ho.. Send for list. Sid Mickelan Illinois.7217
Avenue,
U. S. A.
3617
D. C.
France
France
France
France
France
France
France
Ill.
WAN'T'ED) GOOD TYPEWRITER.
Hase 8 tube Super cot auunications receiver 550- 24.000 K.C. A.V.C. manual
switch. standby switch B.F.O. injection. pitch control. bandswitch. volume control and off switch. R meter.
Alvin heal, Fontana. Calif.
VWl
rd. Jose A.
alla _3. Santiago
tOSIE ON ALL
SWL'S! YOUR ATTENTION l'SE.
I will exchange SWL carda with any
SWL In U. S. A. or foreign counSWL EXCHANGE
tries. All crds received will be promptly
SWL'S FROM ARIZONA. AItKAN- Bobanswered. What say. sane f (IRA:
sas. Delaware, Georgia. Idaho. Ken- ley, Greenough, 46 Chapel St., ShirMau.
tucky. Nevada, New Mexico. Noah
ATTENTION SW1.S ALL OVER
Carolina. North Dakota, Rhode Island.
South Dakota, Tennessee. Vermont. the world. I will swap SWL cards
Wisconsin. Wyoming -send your card. 100% with anyone. You mend yours.
100% QSL. ORA: Jack Ilartley, 88 I'll send mine. QRA: Miles H. Mott,
Diamond Bridge Ave., Hawthorne. New 61 Grace Street,
Cranston, Rhode
1
France
France
South Africa
South Africa
France
France
France
France
France
France. South Africa
South Africa
South
South
South
South
Peoria.
AN
3
Swap
Ix
France
France
WANT TO TRADE OR BUY
SWL'S OF THE W1)1t1.D. LET'S
transmitting parts. Need: x-tul alike; swap
lands. 100°
QSI. anywhere by
power supply components: audio z- return post. QRA.
Wilfred Tarboltan,
torment; tank coils, condensers. etc., 25 Curzon Rd.. Bradford
Moor. Itradfor 100 watt transmitter. Have: 845. font. forks, England.
801's (used 10 hours); .410 shotgun;
SWL'S.
LET'S SA\'. \l' l'AI{1)
h.
Dean Cooper, So. 17th. Fort
Will exchange cards with anyone In
In81ge. Iowa.
the
Will QSL 100%. QRA.
WANTED: ALL TYPES 1RA1)10 Jamesworld.
Nelson,
Erlo Street,
testing equipment. also hiders man- Toledo. Ohio, U. S.1838
A.
uals in A -1 condition, also a short
S\t'L EXCHANGE. WOULD LIKE
course in radio for beginners. Cash.
Fred) Ilabson. 501 E. Lowe St., Fair- to exchange SWL card in U. S. and
foreign countries.
SW AC -DC RE- field. Iowa.
tubes and coils. runs
HAVE ELECTRICAL LIBRARY.
for SW3 with colle QST Magazines.
other
magazines.
and tubes. N. Dale. 25 Wall St., radios,
radio parts. motors. other
Arlington. Mass.
things. Send swap list for swap list.
FOR SKY BUDDY OR Ail letters answered. Want test osell.
TitADE
Super
Clipper. Stereos heavy barrel lator and crystal pickup. Bert Agnew.
target rifle. Barrel drilled for scope 360 North Itockhill, Alliance. Ohio.
blocks. also interested in buying or
STAMPS TO TRADE: 1300 IN EXtrading for A.C. Ultra Air Rover 2. pensive album. Would like to get
transceiver. Bobbie llover. Box 111. short-wave set in running order or
Jams 1. Calif.
what have you in this liner Roger
TRADE: SW3. 160, 80. 20. BAND - Minard, Jr., Concord Rd.. Westford,
spread coils. power supply. eleven tube, Mass
dual band. Kadette radio, dynamic and
WHAT AM I OFFERED IN TRADE
magnetic speaker. tubes, parts, cann- for: Radio parts, Itobotrol, auto fan
era. Want Sky Champion. Sargent 39, roller skates. sheet metal punch, teleNI44.
Hue
Diament,
Perklomen scope. jigsaw, 2 books). More informaSchool- Penneburg, l'a.
tion on request. Best trade offer taken
111'NDRED GOOD EO1t511'I.AS. them. Arthur Hiller. Manito. III.
radin reading course, 'Business Letter
SWAP OENEMOTOR 6 VOLT INWriter."
Toasts
Speeches." Dut, 135 volt 30 ma. output for 11141
and
"Tricks and Knacks of Fishing." crystal oscillator or preselector or what
"Tricks with Coins." guitar and violin have your Write: Lester Fuller. Jr.,
instruction books. What have you? Seligman, Ariz.
W.
R.
Schroeder. 803 Wisconsin.
HAVE
speaker.
Neb.. Penna.
on
Y.
I
teiver. with
VQSELD
OOSAJ
S )1MW
FA3FB
J-r
Md.
Neb.
VSSââ4KTB
CNIAF
N.
Penna.
ISNTltt799(1N:i
artificial marble. etch
resilver mirrors and 97 other
quality formulas. Also two tube recoiver (13 -343 meters). What have
your M. E. Schleicher. 930 Hamilton,
Peoria. 111.
HAVE $25 WORTH OF S10DEI(N
radio parts. tubes, books. etc.. teem
numerous to mention to swap for photographic
equipment
or
microscope.
Sieser, 56 Willett St., New York.
glass.
Penna.. N. C.
Penna.
Penna.
Md.. Ala.,
Ohio
Ti4\DE
how to make
Conn.
Ohio
Conn.
Conn.
N. J.
Ohio
Ala.. Penna.
CN8BA
WILL
Penna.
Cann., Ariz.
14.38
5
6
14.04
4 6
14.095 4 6
14.09
4
7
14.08
5
6
14.10
5 6.9
14.08
4
6
28.11 4 -5 6 -7
14.06
4
6
28.52
5
8
14.160
4
5
14.260
7
5
14.05
4
6
14.13
5 7.8
CN8AY
CN 8MV
ZT6LN
BARTER and EXCHANGE FREE ADS (continued)
Md.
Neb.
u
l
-
-
BIT
Please say you saw
it
in
RADIO 8 TELEVISION
765
featuring construction of the most popular
short -wave receivers and transmitters
with
to Radio & Television
a One-Year's Subscription
are particularly valuable to the experimenter
LIST. These
and conprojects
structor who builds "his own'. Indeed, the 50 publications shown on this page
represent the cream of recent radio construction by the master radio builders
of America. Designs of this kind usually are sold for 25e to $1.00 apiece. and
frequently you do not get half the technical information we gire you.
When mailing us your subscription. use the special coupon on this page.
Select your 15 projects by their serial numbers. We accept money orders, cash.
checks or new U.S. stamps (no foreign stamps Or currency accepted). If you
send rash or stamps register your letter against possible loss.
in size about
publications are large printed sheets which average
All have photographic
11 317. the majority of them printed on both sides. detail illustrations.
In
well
as
as
7HFSE
reproductions of the complete project,
and various technical details to
addition, there are complete wiring diagrams
set.
assist the experimenter and builder in constructing thetext
runs anywhere from
Full parts lists are always given, and the printed
the complexity of the radio receiver.
500 to 3,000 words. depending
ARE STRICTLY UP -TO -DATE:
ALL RECEIVERS AND TRANSMITTERS-DATE
PUBLICATIONS IN THIS
THERE ARE NO ANTIQUES OR OUT -OF
THESE 15 PROJECTS, IF BOUGHT SINGLY, WOULD HAVE COST
YOU $1.50. YOU CAN NOW GET THEM ABSOLUTELY FREE!
HOW TO BUILD THE SWITCH BAND -2 RECEIVER.
A law -cost receiver for 6 volt battery or A.C. operation
which enables the short-wave fan to hear stations in all
parts of the world
THE
HOW TO MAKE A 2 -TUBE RECEIVER FOR
two
BEGINNER. This receiver consists of detector toandsecure
used
audio
the
audio stage... Tubes are for 11V, volt battery operNo. 2
ation.
4.
HOW TO MAKE THE PORTABLE SUPERHETThis
operation.
battery
for
An ace all -wave superhet
receiver features band - spread End has a built -in beat
No.
oscillator.
HOW TO MAKE A REAL 5 -METER SUPERHET. This
carefully designed receiver for ultra 'short w v e recepstraightforward circuit. Careful placetion employs
Ne. 17
ment and high quality parts insure One results
HOW TO BUILD THE 2 -VOLT SUPER DX -4. This
n
performance.
is
big
size
superhet. though small in
Using battery type tubes. tt features continuous bandspread. and automatic volume control. which may be cut
No. 18
in or out as desired
HOW TO MAKE THE ULTRA -HIGH FREQUENCY
regenerasuper5
-meter
WIZARD -8. This is a first -cless
tive receiver. using acorn tubes in the R.F. and detector
HOW TO BUILD A 4-BAND 3 -TUBE SUPERHET.
A 3 -tube receiver giving 4-tube results. Rack and panel
type construction is employed. It has a regenerative
second detector
HOW TO MAKE A FIXED -BAND 8 -TUBE SUPERHET.
TMs short -wave "fan" receiver tunes over a wide band
of frequencies without coil switching or changing. It's
A.C.
real performer. It operates directly from 110 V. No.
and has band- spread
HOW TO BUILD A 5 -TUBE SUPERHET FOR FAN
AND HAM. A sure -fire receiver for all short -wave en-
HOW TO BUILD A HIGH -GAIN METAL -TUBE RECEIVER. This little receiver is a real performer. tuning
from 10 -200 meters. Continuous band - spread is Pro-
stages. The other tubes are of the metal type. The use
of the acorn tubes insures exceptionally fine results. No. 19
WORLD -WIDE 10-METER
TO BUILD THE
CONVERTER. Many enthusiastic reports have been received from the builders of this unit. which may be
attached to your present receiver for picking up 10 meter
signals from all parts of the world. Only 2 -tubes
HOW
operation with headphones
HOW TO BUILD AN EFFECTIVE
SHORT WAVE
PRESELECTOR. A signal- boater that will greatly improve reception on any short -wave super. It employs two
in
6E7 tubes In parallel in a highly efficient circuit
No. 8
which both Input and output are tuned
This
HOW TO BUILD A REGENERATIVE 2-TUBER.
unusual receiver has the tickler coil in the screen grid
circuit of the detector.
meters; band -sD ead
may be employed
ie
ncluded;
tunes
metal
or
glass tubes
No.
9
HOW TO MAKE THE S.W.aT. COMMUNICATIONS
critical
RECEIVER. An unusually fine receiver for the features.
Ham and Fan. incorporating many exceptional
stage
the
uan
Regeneration is employed
acorn tube. The receiver alo
akes se
noise -control circuit. variable selectivity
incorporates
No. 10
tuning meter
control and
HOW TO MAKE A BAND -SWITCHING 2 -VOLT REemoperation
battery
for
receiver
foe
This
CEIVER.
ploys
a
tune afomw16 -550 meters gby flipping aliswitch. No.
I
I
HOW TO BUILT THE MULTI -BAND 2 RECEIVER.
reA receiver for the short -wave beginner. It has
with hand markable tuning range of 2% -270 meters and
complete
spread on all bands. Plug -in coils are used
No. 12
data for an A.C. power supply is given
HOW TO MAKE THE VS -5 METAL TUBE SUPER
This complete all -wave receiver boasts. among
H ET.
ether things. variable selectivity. metal tubes. AVG and
17
-550
is
from
range
The
tuning
bend- spread.
No.
meters.
13
HOW TO BUILD A BEGINNERS 2 -TUBE SUPER. A
simplified superhet using 2 volt battery tubes which is
lust the thing for the beginner. It employs plug -in
15-200
from
tuning range
which cover a
coils
.
meters.
HOW TO MAKE A T.R.F. -3 FAN RECEIVER This is
an all- around receiver employing 2 volt tubes. A T.R.F.
stage ahead of the regenerative detector insures good
bY
selectivity and sensitivity. Band- spread is provided
No.
two -speed dial
RECHIVER
HOW TO BUILD THE FORTY-NINER
FOR LEAN PURSES. This novel receiver features
space-charge detector and requires only 12 volts of B
from
operated
be
which
may
tubes
battery. It uses 2 -49
-A
8
any 2 volt A battery
RADIO & TELEVISION,
99
are
used.
I.B.
thusiast*. It uses plug -in coils and iron core No.
6
transformers which assure plenty of gain
RECEIVER.
-PENTODE
TWIN
HOW TO MAKE A
embeginner,
This receiver, especially designed for the gives results
ploys but one dual purpose tube which 2 -volt battery
equivalent to a 2 -tube receiver. It is for
receiver
No. 20
vided.
HOW TO BUILD A DE LUXE 3- TUBER. This is the
receiver for the Ham or Fan who wants a really high
class receiver of simple design. It employs an unusual
metal
The circuit. employing
band -spreading dial.
tubes, has a stage of T.R.F. followed by a regenerative
No. 22
detector and a stage of audio
HOW TO BUILD THE OCTODE METAL TUBE -l.
This receiver is capable of excellent performance on
the short waves. It requires only one plug -in coil for
stage of untuned R.F. precedes the
each band as
detector. It also has an A.F. stage for boosting the
No. 23
volume to comfortable headphone level
HOW TO MAKE THE 3 -IN -1 REFLEX SET. A 2 -tuber
giving 4 -tube performance is this receiver which does
its work with a minimum of tubes. A 6F7 is used as
combined R.F. amplifier, detector and first audio stage:
No. 24
a 6C5 is used as second audio stage
HOW TO BUILD THE 100 WATT 0RM DODGER
A COMPACT -METER TRANSMITTER. This M.O.P.A.
rig puts out a hefty signal and by use of a calibrated
vernier oscillator control will overcome the QRM problem
-
5
on
5
No. 25
meters
BUILD A DE LUXE 3-METER MOBILE
STATION. A really One M.O.P.A. mobile transmitter
which will work real DX on portable location. It emHOW TO
MEDIUM POWER
TRANSMITTER. A crystal control set with an output
of 90 watts. Band -switching is employed for operation
the 80, 40, 20 and 10 meter Ham bands. It gave
NO. 27
excellent results under test
HOW TO MAKE THE 806 ALL -BAND TRANSMITTER.
An unusual transmitter delivering 400 watts output
from an 806 final amplifier. A crystal pen -tet oscillator
is used, followed by a driver stage. Real DX has been
worked on 10. 20, 40 and 80 meters with this smooth
No. 28
working lob
HOW TO BUILD A 125 -WATT MODULATOR USING
35T's. This is an Ideal unit for the amateur and will
modulate any transmitter with a power input up to
about 400 watts. A total of 10 tubes are used including
No. 29
the power supply unit
HOW TO BUILD THE C -O-M ISO WATT TRANSMITTER. An unusual crystal oscillator. multiplier with
but one tuned circuit. It uses a pair of RK3T's in
parallel with a RK39 driver. The crystal oscillator
circuit
uses
a
No. 30
81,6
-METER
LONGLINES TRANSMITTER FOR
TRANSMISSION. AND A COMPANION RECEIVER.
A really special job for the seriously minded experimenter. This outfit permits short distance contacts
cto. 31
in
this interesting band
A
1
Hudson Street, New York, N. Y.
or 33.5o for which
Nun.
State
Wes-
ey order. Register letter If you
n
Send remittance by checkunused
U. S. Postage Stampa
a h or
':l'
d
8
10
13
14
15
18
23
19
20
25
33
24
29
34
38
43
39
44
48
49
40
45
50
2
7
3
11
16
12
17
22
28
36
41
27
32
37
42
46
47
21
26
Please say you saw
it
in
5
4
9
1
6
31
Address
766
M -G -M
on
my remittance
Gentlemen: Enclosed you will find
AND TF.I.EVISñON for One Year (1!
bacriPtion to RADIO
enter my
l'.
promptly. absolutely FREE, and POSTPAID- the
Ìsxues). Send
$3.15 .'
at
publications
SUBSCRIPT ON
t D EXTEND PRESENT SUBSCRIPTION
NEW SUBSCRIBER
city
No. 26
ploys fire metal tubes
HOW TO BUILD THE
30
35
RADIO 8 TELEVISION
HOW TO BUILD A 200 WATT XMITTER WITH
PEN -TET EXCITER. This transmitter will reIly go to
town. The use of the Pen -Tot crystal oscillator and
multiplier circuit eliminates many headfrequency
No. 32
aches from cracked crystals
TO BUILD A 10 AND 20 METER TRANSMITTER. A 200 watt transmitter which worked worldwide DX on test. Although compact. it U highly
efficient In the 10 and 20 meter bands. Five tubes are
HOW
No. 33
used.
TO MAKE THE WIZARD I -TUBE 50 -WATT
TRANSMITTER. An amateur, crystal -controlled c.w.
transmitter using the RE20 screen grid pentode. In tests,
No. 34
it compares with 250- wetters
HOW TO MAKE THE "OSCILLODYNE" I TUBE
short
-wave
WONDER SET. One of the mat sensitive
sets designed, employing a really new circuit for the
No. 35
first time. Battery operated
HOW TO MAKE THE "19" TWINPLEX (ONE TUBE
HOW
PERFORMS AS TWO) RECEIVER. One of the moat
sensitive I -tube sets ever designed and very popular.
140W TO MAKE THE IMPROVED S -TUBE DOERLE
SET FOR BATTERY OPERATION. One of the finest of
the Merle series. by the famous short -wave invent
r.
MAKE THE "GO- GET -'EM 2" RECEIVER
THE BEGINNER. This unusual 2 -tube circuit
Battery operated. Excellent for
3 -tube results.
38
beginner..
THE
-TUBE ALL-ELECTRIC OSCIL
HOW TO MAKE
re-wave
LODYNE. This is the famous electrified short
ceiver. Easy to build for little money. Operates on A.C.
No. 39
and D.0
HOW TO MAKE THE 2 TO 5 METER TWO -TUBE
LOUDSPEAKER SET. This receiver may be used with
batteries or with an A.C. power pack. Packs a big
HOW TO
FOR
gives
1
No. 40
wallopHOW TO
MAKE THE 3 -TUBE BATTERY SHORTprice winner in
WAVE RECEIVER. This receiver was
SHORT WAVE CRAFT. An unusual short-wave receiver..
easy
to
build
BRIEF -CASE SHORT -WAVE RECEIVER AND
HOW TO BUILD IT. 8o small that the entire set, bat
brieftories, head set, aerial and everything. goes into
case. Stations from Europe are often received. By Hugo
NO. 42
Oernsback and Clifford E. Denton
HOW TO BUILD THE POCKET SHORT -WAVE REreCEIVER. One of the smallest, pocketsize, battery
ceivers ever designed by Hugo Gernsback and Clifford
B. Deacon. A marvelous set that brings in Europas
Ne. 43
statiopa.
HOW TO BUILD THE CIGAR -BOX I -TUBE "CATCH
set
ALL" RECEIVER. An effective short wave battery
small cigar box. Inuring high portability
which fits into
No. 44
yet great emciency
HOW TO BUILD THE "DUAL -WAVE" SHORT -WAVE
BATTERY RECEIVER. With this set. you can hear both
ends of radiophone talk, on one set of phones. In
other words. you can listen to a ship at sea and the
land station communicating with it, simultaneously, by
eiver
means of this double
HOW TO BUILD THE I -TUBE "53" TWINPLEXRECEIVER. The twinpiex, although it has only one tube.
Marvelous in efficiency. Uses
two.
it
had
If
works as
either batteries or A.C. power pack for "B" Np ply,
THE
SHORTHOW TO BUILD THE PORTABLE MINIDYNE
TM
WAVE BATTERY SET. Uses no aerial, no ground. Self
total weight is 3% lbs. and measures 5x516 inches. ghlycontained batteries. tube, condensers. and loop.
sensitive circuit
HOW TO BUILD THE HAM -BAND "PEE -WEE" 2-and band
TUBER. A dandy receiver with high efficiency
spread tuning. Work]. a loudspeaker. yet the entire reeither
ceiver is no larger than your hand. Works with No.
48
power
pack
batteries or an A.C.
ideal
The
AMPLIDYNE.
DUO.
THE
BUILD
HOW TO
1 -tube
finest
of
the
One
set for the beginner.
1 -tube
for batsets: it really gives 2 -tube performance. Made
tery operation. With only ten -foot antenna brings
No. in
stations
European
the good
Ñ
V. No more
coils. This set eliminates bothersome coil.
to cover short -wave bands. Works with
Mo. 50
either batteries or A.C. power back.
TO
HOW
"plug in"
and
is
BUILD THE "MONO -COIL
made
RADIO & TELEVISION
HUDSON STREET
NEW YORK, N. Y.
99
RADIO
&
TELEVISION
On the "Ham" Bands
Call
W5DW
W5EB
W61TH
W6BYL
W6NBU
W6PDB
W6EJC
W7AFS
W7AYO
W8BJJ
W8CRR
W8DST
W8ETJ
W8FAR
W8FGU
WeHHZ
W8JLW
W8NKA
28.8
29.4
14.23
28.85
29.015
29.0
14.16
14.228
29.0
28.85
28.635
28.75
29.4
28.6
29.0
29.425
29.5
28.915
France
France
South Africa
5
France
6
France
8
France
4
6
France
5 3.6
France
5
7
France
5
7
France
5
8
France
5
9
France
4
7
France
5
7
France
3
7
France
France
5
8
France
5
9
France
5
8
France
5
7
France
- - France
France
5
8 France
5
9 France
5 8 -9
France
4
6
France
5
8
France
France
5
9
France
3
France
7
5
8
France
5
France
7
France
5
7
South Africa
5
8
South Africa
5
8
France
5
8
France
4
7
France
5
9 France
5
9
France
5 8 -9
France
3
8
France
5
8
France
5
9 France
5
8
France
5
9
France
- - France
W8RWN
WBNYD
WBOXY
W8PES
WBPPR
W8PYO
WBRKR
WBRLT
W8SRP
W9ULJ
W9ZAL
W9L'HA
W9WBW
W9CBJ
W9URQ
W9EAB
W9PBY
W9QHS
W9ROQ
W9TWZ
W9UDW
W9USU
W9UWY
W9WUC
W9ZNA
6
6
9
3
5
5
5
5
5
14.24
W8I1SX
FREE CATALOGS and INFORMATION
(continued from page 765)
Freq.
R S
Where Heard
14.215
14.195
28.6
29.1
29.46
29.04
28.645
29.1
29.11
28.7
14.225
14.
28.5
28.5
29.11
29.1
28.98
28.515
28.91
29.375
29.0
28.68
29.315
29.11
carefully reading the advertising columns, you will find many offers to fu nish li erature
containing valuable fchnica information that will help you in your work. Use this lis freely.
By
Firm
Business
Aerovox Corporation
Allied Engineering Inst.
Allied Radio Corp.
American Radio Institute
Bliley Electric Co.
Brush Development Co.
Bud Radio. Inc.
Burstein -Applebee Co.
Cameradio Co.
Candler System Co.
Parts Mfr.
Kit Mfr.
Mail Order
Radio School
Parts Mfr.
Parts Mfr.
Parts Mfr.
Mail Order
Mail Order
Cannon, C. F., Co.
Code Course
Parts Mfr.
Capitol Radio Engineering
Radio School
Institute
Cornell -Dubilier Elec. Corp.
Coyne Electrical School
Parts Mfr.
Trade School
Dodge's Institute
Gold Shield Products
Guthman. Edwin I., & Co.
Hammarlund Mfg. Co.
Radio School
Mail Order
Set & Parts Mfr.
Set & Parts Mfr.
Reception of the South American amateurs is
falling off fast. A few months ago, there were
too many to publish, but this month it is quite
different story. We have a few reported. but
not nearly as many as have been in the past.
VP3AA
14.195
5
9
Ark.. III.. Colo., Me.,
Ariz.. Conn.
LUIDA
14.075
5 6 -8
Ark.. Wash.. Ill.,
Ariz., N. Y.
a
LU2AC
Ltt41tC
LU4UJ
LU4PII
LU4CZ
LU5CZ
5
8
4
14.1
4
6
9
6
6
5
5
14.04
5
8
14.085 4-5 5-9
LU5CK
LU7AG
LU7HK
LU8AB
LUSEC
LU8I1L
LU9DM
PY1MH
PY2PV
PY2M I
PY2JC
PY2AC
14.02
14.095
5
14.
5
14.100
5
14.01
14.
14.01
4
7
5
9
5
8
14.080
14.155
14.272
4
5
5
5
7
5
7
5
4
14.
9
9
5
9
14.105
4
6
14.075
5 4 -5
14.090
5
7
14.03 3.5 5 -9
PY2DA
PY2CA
PY4CT
PY5AQ
PY7A1
PY8CF
14.
4
5
14.3
5
5
6 -7
5
6
3
5
4
5
5
14.090
14.290
14.06
14.055
14.02
CXIAA
CX1AH
CX2CO
CX3AL
HCIFC
HC1PZ
HCCC
HC2HP
HC2BU
ON4DM
ON4ZK
ON4FE
HK1AG
HK1AZ
HK2AA
HK3TO
HK3CG
14.1
14.3
4
14.16
14.265
14.01
28.3
4
8
6
6
5
7-8
5
5
5
5
5
6
4
4
6
6
14.2
5
5
6
14.28
5
14.01
5
28.0
14.035
14.05
14.25
HK3CW
14.27
5
14.07
5
14.272 3-4
14.087
4
14.253
5
14.070 4
HK4DF
HK5EE
HK5AR
HK5D11
CEIIIC
CEIAH
8
3
5
28.2
HK3K
CE2BX
CE2BR
CE3BK
28.05
14.030
14.19
14.075
7
7
8
6
7
7
5
5 -7
6
7
5
6
9
8
8
4
5
14.
5
14.14
14.059
14.10
5
Canada
Wash.
Ark.
Ark., Md.
III.
Colo.
Ark.. Wash.. Ill.,
Ariz., N. Y.
Md.
Wash.
South
France
III.
South
France
Africa
Africa
Ark.
N. Y.
N. Y.
South
Wash.
1939
Martin Research & Mfg. Corp.
Mass. Radio School
Africa
Ark.. N. Y.
Ark.
France, South Africa
Colorado
Canada. N. Y.
France
France, Ill.
III.
III.
Wash.
France,
Md.
Mail Order
Mail Order
Set Mfr.
Code Machine
Parts Mfr.
Parts Mfr.
Set Mfr.
Coil Winding
Machines
Radio Keys
Radio School
Midwest Radio Corp.
National Company, Inc.
National Plans Institute
National Radio Institute
National Schools
Radio & Technical Publ. Co.
Radio Train. Assn. of Amer.
RCA Institutes. Inc.
Remington Rand. Inc.
Set
Sargent, E. M., Co.
Solar Mfg. Corp.
Set Mfr.
Parts Mfr.
Mfr.
Set & Parts Mfr.
Publisher
Radio School
Radio School
Radio Textbooks
Radio School
Radio School
Typewriter Mfr.
Ill.
Ill.
Canada, N. C., Ohio
France
Canada
Canada
Canada
Connecticut
Connecticut
N. Y.
N. Y.
Me.
Sprague Products Co.
Sprayberry Acad. of Radio
Supreme Publications
Teleplex Co.
Thordarson Electric Mfg. Co.
Parts Mfr.
Radio School
Publisher
Code Machine
Parts Mfr.
III.
Canada, Colo.
Colo.
Ill.,
Ill.
N.
Y.
N. Y.
Wash.
South Africa
III., Colo., Ariz.
III.
N. Y.
(Continued on following page)
for April,
Harrison Radio Co.
Henry, Bob
Howard Radio Company
Instructograph Company
International Resistance Co.
Korrol Radio Products Co.
Lafayette Radio Corp.
Levine, M. M.
Triplett Electrical Inst.Co.
Tri-State College
Turner Co., The
Wholesale Radio Service Co.
X. L. Radio Laboratories
Zenith Radio Corporation
Please say you sew
it
in
Parts Mfr.
Radio School
Parts Mfr.
Mail Order
Parts Mfr.
Set Mfr.
RADIO á TELEVISION
www.americanradiohistory.com
Offer
No.
Catalog
Circulars
Spring Radio Catalog
Radio Builders Handbook
Booklet
Engineering Bulletin
Circular
Catalog
Catalog
Station Log & Data Bk.
Catalog
1939 Catalog
Book of Facts
Folder
Booklet
Catalog
Electrical Catalog
Radio Catalog
Catalog
Catalog
Information
1939 Catalog
Booklet
Information
Information
Booklet
Information
Literature
Cost
Ado.
Page
Free
751
Free
746
Free
739
10c
Free
748
E -6
10c
753
A -6
Free
Free
739
RT49
Free
752
10c
T -4
166-A
430
Free
753
Free
755
Free
748
Free
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707
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Free
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744
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Catalog
Free
737
Catalog
1939 Catalog
Catalog
Book Catalog
64 -page Book
Radio & Television Skit.
Circulars on each Book
Book
Catalog
Free
748
Catalog
Radio Catalog
Information
76
52 -page
Catalog
Information
General Parts Catalog
Transmitting Catalog
Condenser Testers Cat.
Condenser Catalog
9S
2X
CBCC -I
Bulletin
Radio Catalog
Information
Information
750
Free
I.B.C.
Free
750
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Free
705
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749
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S-4
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344
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747
346
15c
342
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52 -page
Book
Information
Booklet
Transmitter Guide
Sound Amplifier Guide
Radio Service Guide
Transformer Manual
Catalog
Catalog
Free
340
41 -A
76
748
50c
Free
759
Free
748
Free
755
Free
741
Free
750
Free
B.C.
767
G REATEST
BARGAI N
in
10
years
On the "Ham" Bands
Index to Advertisers
(Continued from preceding pogo
Call
CE3DU
YVIA
YV1A
YV4E
YV4APB
1'V4ABG
YV4AE
YV5AK
YVSADY
YV5ABY
YV5AY
1'VSAE
YV5ABF
Y\'6AM
VP4TK
R
S
5
14.05
5
14.005
14.2
5
14.2
5
4
14.16
14.089 4 -5
14.065
5
6
6
Freq.
14.030
14.11
7
7
Ill.. Me., N. Y.
Wash.. Ill., N.
4 -8
7
8
5
5
5
9
4
7
5
A
14.165
14.06
14.087
4
4
4
6
14.1
5
6
8
Barter & Exchange Free Ads
Bliley Electric Co
Brush Development Co., The
Bud Radio, Inc
Burstein -Applebee Co
France
Camcradio Co
Candler System Co
Cannon, C. F.. Company
Capitol Radio Engineering Institute
Commercial Notices
Cornell -Dubilier Electric Corp
Coyne Electrical School
little
as
Remington
VK2XU
VK2ABU
VK2RY
NOISELESS
V K2JO
VK2GN
Portable
VK2TL
\'K2AFQ
VK3KX
VK3XG
NOW AS LITTLE AS
lOc a day
Imagine a typewriter that speaks in a whisper!
You can write in a library, a sick room, a Pullman berth, without disturbing others. And
superb performance that literally makes words
flow from the machine. The Remington Noiseless Portable is equipped with all attachments
that make for complete writing equipment
manifolds and cuts stencils perfectly. Furnished
in black with chromium fittings.
-it
SPECIFICATIONS
Standard keyboard. Takes paper 9.5 inches
wide. Standard size, 12 yard ribbon. Makes up
to 7 legible carbons. Back spacer. Paper fingers.
Roller type. Black key cards with white letters.
Double shift key and shift lock. Right and left
carriage release. Right and left cylinder knobs.
Large cushion rubber feet. Single or double
space adjustment. A brand new NOISELESS
typewriter, right off the assembly line.
10 -DAY FREE TRIAL
For the first time in history you can own a genuine Remington Noiseless Portable for as little as
10c a day or $3.00 a month. Think of it! The
finest Remington Portable ever built at the
lowest terms we have ever offered.
And you don't risk a penny! We will send this
brand new Remington Noiseless Portable for a
TEN DAYS' FREE TRIAL! If you are not
satisfied, send it back. We pay all shipping
charges.
FREE-
COURSE
-
With your Remington Noise-
absolutely
course in
teaching you the
Touch System, always used
by experts. With the help of
this course you will find typing the most enjoyable way
you ever wrote.
less
Portable
-a
typing
free
19 -page
SPECIAL
Address
768
State
5
14.1
5
14.25
14.337
5
4
14.
4
6
6
9
6
6
14.3
14.09
14.31
5
8
4 -5
6
6 -8
6
F
762
For Sale Ads
South Africa
Ohio
Ohio
France
Penna.
South Africa
France
Penna.. Ohio
France
750, 761
747
H
Kan., Colo.. France.
South Africa. Ala.
Ark.. Ore., Colo.
Korrol Radio Products Co
5
K6OFW
14.225 4.5
K6ILW
14.12
14.085
K6IQN
K6C)IC
1:60Q
K6RG
K6GAS
K6PLG
7
-8
5 6 -8
4
7
5
6
5
6
4
8
8
5
14.1
14.2
K6LKN
K6BNR
28.575
14.235
28.4
28.5
28.9
28.5
14.18
K6PLZ
K6OQE
14.185
14.190
5
5
8
8
28.375
5
5
9
9
K6TP\\'
K6QQM
K6OJI
14.2
PKIJIF
PK11iX
PK1VY
PK4KH
PK4KS
PK6XX
ZL3GU
ZI.3TF
ZL4CB
ZL6AZ
4
5
5
6
5
5
5
14.250
14.342 4 -5
9
5 -6
14.145 4 -5 6 -8
9
5
14.310
8
5
14.282
9
5
14.11
14.
5
8
14.228
14.14
4
5
5
6
14.2
14.26
5
5
5
8
14.08
14.285
5
14.3
5
9
9
9
14.
14.
5
5
5
8
8
9
14.295
5
9
14.14
5
14.225 4-5 6 -9
5
6
14.34
7
14.3
5
14.050
14.3
28.25
14.115
28.1
Ill..
Ariz.
Wash., Ill.,
Colo.,
Wash.,
4 -5 3 -7
14.31
Colo.,
8
9
14.21
VR2FF
Ill.,
5
5
4
7
5 8 -9
KA7EF
Colo.,
8
Canada
Ore.
Ore.
Ore.
Ore.
Wash..
14.185
14.175
29.01
28.75
K6QAF
K6DTT
VR6AY
Ill.,
7
14.18
K6IlIR
K6NVV
Martin Research
7
K6\IZQ
K6OTH
Lafayette Radio Corp
Levine, M M
5
5
4 6 -7
8
5
- 5
4
6
4
5
7
it
757
L
741
753
M
Ariz.
Penna.
Wash..
Colo..
Ariz.. Utah
Wash., Colo.
Wash., South Africa
Ill.
Ill.
Africa
Ill.,
Kan..
Ohio.
France. Colo..
Ala., South Africa
Kan., South Africa
South Africa
South Africa
South Africa
South Africa
Utah
Utah. Wash., South
Africa
France
France
France
France
France
South Africa
South Africa
France
France
France. South Africa
France
France
Kan.. Ariz., N. Y.
France
France
Ore.
France
Ore.
Well. that finishes it for another month. It is
hoped that you will like our new arrangement.
and your letter of comment will be greatly appreciated. If you have any ideas for bettering this
department. send them in to us. Your criticisms
are always welcome.
Please say you saw
744
754
743
&
Manufacturing Corp
Mass. Radio School
Ariz., Utah
Wash., III., Colo.
Colo.
South
750
K
Ark., Ill.. Colo.
Ark., Wash.
Ark.
Ark.
5
K6KGA
PK2FS
PK3W
PK4CB
Name
14.4
752
748
748
PK2KT
PK2AY
Remington Rand Inc. Dept.800-4
465 Washington St., Buffalo, N. Y.
Tell me, without obligation, how to get a Free
Trial of a new Remington Noiseless Portable,
including Carrying Case and Free Typing
Course for as little as IOc a day Send Catalog.
14.
D
Dataprint Company
Dodge's Institute
G
Gold Shield Products
Guthman, Edwin I., & Co., Inc
Ariz.
6
748
757
748
762
755
707
Instructograph Company
International Resistance Co
PK1ZZ
PK1GR
MAIL NOW
7
Oceanic stations
KAIBH
KAIJM
KA2O\'
take your machine anywhere.
You can use it on trains, or
on your knees at home. Don't
delay. Mail the coupon.
France
Penna.
Penna.
8
8
4
4
4
755
increased in number during
January, particularly those located in the Hawaiian
Islands and the Netherland Indies.
VK4JP
VK5MF
VK7CL
VK9VG
KA1HS
CASE
5
739
752
753
737
753
K Al CS
CARRYING
14.1
14.05
14.234
14.135
753
Hammarlund Manufacturing Co., Inc.
Harrison Radio Co
Henry. Bob
Howard Radio Company
Hudson Specialties Company
KA1ME
Carrying Case, handsomely
covered in DuPont fabric is
induced with your purchase.
The case makes it easy to
City
From Australia we have only a very few stations reported. They were rarely heard during
January.
5
762-765
C
Due to the large number of Europeans heard
and reported by our observers during January. it
is impossible for us to print the usual list. This
continent seemed to be very well heard last month.
and about two hundred stations were reported.
Therefore, we will skip Europe for this issue. but
continue to send in your reports on this continent
as it will probably be used in the next issue.
as
746
739
748
Colo.. Ariz.
France, Conn.
N. Y.
Ohio, N. Y.
N. Y.
N. J.
Colo.
Ill.
7
751
Aerovox Corporation
Allied Engineering Institute
Allied Radio Corporation
American Radio Institute
Me.
Me.
8
5
14.1
14.1
Where Heard
France
Wash.
Ohio
in RADIO 8 TELEVISION
Midwest Radio Corporation
737
748
750
N
National
National
National
National
Inside Back Cover
Company, Inc.
Plans Institute
Radio Institute
Schools
750
705
748
R
Inside Front Cover
Radio Amateur Course
749
Radio & Technical Publ. Co
756, 760, 761
Radio Publications
748
Radio Training Assn. of America
748
RCA Institutes. Inc
768
Remington Rand, Inc.
5
Sargent. E. M., Co.
Solar Mfg. Corp
Sprague Products Co.
Sprayberry Academy of Radio
Supreme Publications
753
739
757
745
751
T
756
748
Technifax
Teleplex Co
Thordarson Electric Mfg. Co
Triplett Electrical Instrument Co
Tri -State College
Turner Co., The
747
759
748
755
W
Wellworth Trading Company..
Wholesale Radio Service, Co., Inc.
756, 759
741
X
750
X. L. Radio Laboratories
z
Back Cover
Zenith Radio Corporation
(While every precaution is taken to insure
accuracy, we cannot guarantee against the possibility of an occasional change or omission in the
preparation of this index.)
RADIO
&
TELEVISION
-
'
-v.. ,...,a..--........
..
.
.
.
.
.
.
,
..
....-.1.-.,...
NC -44
If you judge receivers on the basis of performance per dollar
of cost, you will find the National NC -44 an outstanding value.
This seven -tube superhet covers from 550 KC to 30 MC in four
ranges. The full- vision dial is carefully calibrated in frequency.
A straight -line- frequency main condenser is used in conjunction
with a separate band spread condenser, and both have inertia type tuning. A CW oscillator is provided. The performance of
the NC -44 is remarkably fine, even at ten meters where so many
receivers are unsatisfactory. The Net Price is only $49.50, including tubes, speaker and built -in power supply.
NATIONAL COMPANY, INC., MALDEN, MASS.
AMATEURS= YOUR
THOUGHTS
MAY BE WORTH MONEY
CORPORATION
ZENITH RADIO AVENUE --6001 DICKENS
CHICAGO
February
E
F
15,
1939
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www.americanradiohistory.com
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