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AMATEUR 



RADIO 




December 1962 

A Joily 
40< 




^ 



^ 



Frrg 




New standard of performance 
for AM, CW, SSB reception 

Band-pass filter front end— equivalent of four tuned circuits preceding 1st mixer. 
Crystal-controlled high frequency oscillator, 

5 steps of selectivity plus Hallicrafters' exclusive upper/lower sideband selection. 
Linear CTO, direct reading in kc. 




The experienced amateur wUI imme- 
diately recognize in the SX-llS a first 
rate engineering triumph that creates 
an entirdij new class oi deluxe receiver. 

FrequeiWij coverage: Nine 500-kc 
segments covering 3-5^,0 mc; 7.0-7.5 
mc; 14.0-14.5 mc; 21''21.5 mc; 28,0- 
30.0 mc,; (4 segments); and WWV 

Additional features: Highest order of 



mechanical and electrical stability; lin- 
ear tuning; constant tuning rate; sepa* 
rate noise li miters for SSB/CW and 
AM; dual loop AVC; spurious signal 
and image rejection better tlian 60 db, 
down; sensitivity less than one micro- 
volt; perfect match for Hallicrafters 
HT-33 and HT-32 series exciters and 
transmitters* 



the new ideas in communications 



are born at . . . 




Overseas Sales; Contact Hallicrafters 
Commercial Products Division 

Canada: Gould Sales Co., Montreal, P,Q. 




5th and KostnerAves. Chicago 24, IH< 



^ 



73 



4 

Magazine 

Wayne Grean, W2NSD 
Editor, etcetera 



December, i 962 

Vol. XIII, No. I 



Cover: WIMEL 



Two Meter VFO W6TKA. . 

Very at able and uses one tube. Dandy bandspread. 



6 



Modifying the Sixer. , . . , . 

For a 50% power increase. 

Modifymg the HE-45 



K4Z9Q, 9 



.WA2INM., 



10 



Improving the modulation & power output meter for 
this nice rig. 



The Irving Hiverter 50 ... Staff 12 

Six meter SSB converter tested at HQ by WIMEL. Works, 



Alternators . . 



K8ERV 



* * m * 



\b 



With mobile SSB coining at us in a rush we will be 
needing these. 



432 mc Antenna Tuner 

Pictorial article. 



WITQZ 18 



Henry 



Auto Anafyzer , . - , 

Not very hsmmy. Tachometer, dwell angle meter, battery 
VM, temp, indicator. 



20 



Coaxial Baluns WA2INM 

Open wire is the lowest loss, but how do we get from 
coax to open line? 

Selectivity Plus , , ... , W6EUM 

The CW man sometimes goes to great lengths for 
selectivity. 

The Heath HR-20 W4WKM 



26 



28 



36 



•73 tests the Heath itnobile receiver. 



73 Magazine is published monthly 
by 7S, Inc., Peterborough, N, H. 
The phone number is 603-924-3873. 
Subscription rates are still abysmal- 
ly low at $3,50 for one year, $6.50 
for two years* and $9,0a for three 
years In North American and TJ-S* 
possessions. Foreign subscriptions 
are $4*00 per year. Second class 
postage is paid at Peterborough, 
New Hampshire and at additional 
mailing offices. Printed in the U<S*A, 
Entire contents copyright 1962 by 
7S, Inc. Postmaster : please send 
form 3570 to 73 Magazine, Peter- 
borough, New Hampshire- Readers 
should stop reading the fine print 
and stick to the articles and edi- 
toriaL 



AM Oscilloscope Patterns W(^OPA. . 44 

YouVe been wondering what your scope was trying to 
tell you? 



Briefcase Twins . 

Complete portable CW station. 



.W2TBZ 



d- ■ a. 



50 



The Heath Warrior W6EUM 

Full kilowatt linear amplifier by Heath. 



60 



Joe's Other World 

Fiction, 



XYL-G3NMR 66 



Transistorrzed Squelch ,....,. WlTUW, ..... 74 

Squelch is very handy and this circuit is so simple you 
have no excuse. 

The Waters Q-Notch Rlter K2CM 74 



For the KWM and 75S Collins owners that want 
something better. 

The R-45/ARR-7 W5UOZ. 

This is practically an SX^28. Surplus conversion. 



86 



Constant Voltage Power Supply. 



- * * 



W4WKM 92 



A real gem is available in some of those old TV sets. 



Clipper 
Letters 



., 19 

19, 43. 46, 65, 70 
Prlie Winners . 



Rate of Change 
New Products . 
, , . 85 



■* ' * * * * m 



35 

72. 8r 



, r - -w 



DECEMBER 1762 



J 




W2NSD/1 



Kever Say Die 

The Institute 

Many interesting suggestions for activities of 
the InsUtute of Amateur Radio have accom- 
panied the membership apphcations. It is en- 
tirely possible that the Institute may take a 
rather active part in the encouraging of some 
of the more obscure phases of amateur radio 
such as wide-baiicl FM, Ham-TV, amateur re- 
peaters and the like. We are open for further 
suggestions. 

One of the first projects of the Institute is 
the projected Ham Flight to Europe which is 
beginning to take shape* We are trying to ar- 
range a minimum cost three week trip which 
will include London, Paris, Berlin, Geneva and 
Rome, This would give us about four days in 
each city, which would allow us time in each 
city to meet the local hams in a big hamfest, 
see the city and visit a few local amateurs* 
We hope to be able to fly you over on a jet, 
take you from city to city, take care of the 
hotel bills and many of the meals, all for 
around $500, As we talk further with the air- 
hnes we will find out how far off we are. 

London seemed like the most promising first 
stop since the language can be learned in a 
few hours, at least well enough to make do. 
This is one of the most wonderful plac^es in 
the world to shop for men*s clothes . . . and 
the prices are quite reasonable. 

Next stop Paris, Bring lots of film. Virginia 
will have some hints for the XYL's on shopping 
in Paris. TU give you the low down on some 
magnificent but inexpensive restaurants. You 
won't want to miss one of the most fabulous 
night club spectaculars in the world: the Lido. 



This is heady stuff for ministers and scout 
masters, but ever>^one else should have some- 
tfiing to remember for life. We'll try to have a 
first class hamfest here, too, so you can meet 
the French amateurs and perhaps talk one of 
them into driving you through Paris in his 
deux-cheveux. You won't forget that, either. 

Geneva, Switzerland, will probably be our 
next stop, I hope you and the XYL saved some 
monev back in Paris for you will find one of 
the most international shopping areas in Ge- 
neva. Not far awa\^ is Mt, Blanc where you can 
enjoy one of the most exciting tramway rides 
in the world. 

Rome! You 11 love it, Don t drink from the 
fountains ... I bied it. Rent a Vespa and see 
all of Rome for yourself- Waitll you try real 
Italian ice cream , . , mnim. Til have some 
hints on restaurants here, too. Stand by for one 
of the best meals you've ever had* 

Last of all, if we can manage it, will be 
Berlin. We may have to settle for Frankfort, 
Berlin is an experience , . . you can visit the 
Eastern zone and see for yomrself what a dead 
city is like* The department stores of Berlin are 
overflowing with marvelous merchandise sell- 
ing at fractions of what we would expect. The 
XYL's will see some beautiful dresses here . . . 
and furs. You may be more interested in round- 
ing out that, ahem . . . collection of foreign 
slides. 

Virginia and I are convinced that everyone 
should make plans to visit Europe, no matter 
how difficult it may be. Once you make up your 
mind the only problem is how to manage . • . 
and somehow you do. Even if you have to go 
now and pay later it is well worth it. This, 
essentially^ is what we did when we went over 
in April . * . and we don't regret one minute 
of it! 

Since it is necessary for you to have been 
a member of a club for at least six montlis 
before you can accompany that club on a char- 
ter flight it would be prudent, if you have any 



Application for Charter Membership in the Institute of Amateur Radio 

(Valid only if postmarked before January 1, 1963) 



Name . , * , ^ , * , , , Call: , , . 



(must be licensed) 



Address , 



• • 



City.... 

Class of license: 

Year first licensed 

Charter membership fee of $L00 must accompany this application. This will pay dues 
in fuU until December 31, 1963. 



.*•.•*«•*••*•*«* ^oue « * * V • *^ i^tatc .*.*»>•.■..• v^ounty •«•.»■■ 
Novice Technician General Advanced Extra Conditional 

Old calls . , ,...,«..... 



73 MAGAZINE 





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The Communications Receiver that meets every amateur need- 
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388 Page 1963 Catalog 630 



Name 



Address 



f-»«*H»*«'t> 



City 



. ■■■» 1 I" W ^ .-« #^>»*A> ^f t-Q *^?' 1 ■■«|*#ka*.«4«fr|f'l« I ■**»*■ 



I 
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DECEMBER 1962 



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FANTASTIC SALE 

6 meter converter 56 postpaid 

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Low noise figure and 1 microvolt sensitivityi 

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73 




uc 



ts 



MICKEY MIKER 50c 

This is the first of our small bookie ta to come 
off the press. It is a complete description of the 
construction and operation of a little device 
which will measure capacity to a high degree of 
accuracy. This is a gadget that can be built out 
of most junfe boxes and will forever be a handy 
item to have around when you are building some- 
thing new or fixing something old. 

S5B TRANSCEIVER 
SCHEMATIC $K00 

There have been many requests for a giant 
sized schematic of the wonderful little transceiver 
that appeared in the November 1961 issue of 73. 
This schematic comes complete with a spare issue 
of the magazine in case you missed it, 

MRT-90 CONVERSION: 50c 

This booklet gives complete conversion instruc- 
tions for converting the little pack-set surplus 
units into a fine two meter walkie-talkie. An ar- 
ticle appeared in 73 on this unit in the October 
1961 issue. 



73 



Peterborughj N. H, 



idea of possibly going along on this flight, to 
send iQ your membership application to the 
Institute immediately. We can only take 150 
maxim Lim on the trip and date of membership 
will be used as a means of accepting flight 
reservations should there be too many. It is 
only necessary for the OM to join the Institute 
for this automatically includes the XYL, 

It is not necessary to cut your magazine. 
Send the information from tlie membership ap- 
plication together with one dollar and your 
membership card will be sent. Charter Mem* 
berships are available only during 1962. The 
rather startling benefits of Charter Membership 
will be announced once it is too late for every- 
one else to sign up for them, 

Christmas Instructions 

Perhaps I should let you know that I have 
been promising our advertisers that you will 
be spending up a storm tliis Xmas (keep the 
X in X-Ma$, as they say). The only honorable 
thing to do, really^ is buy an extra receiver or 
rig and try to keep me from making such rash 
promises again. 

Actually^ this Christmas thing can be used 
to your advantage if you are a httle crafty. 
You can start out by grumbling about Christ- 
mas, just as you always do, and then, in a 
sudden flash of genius, propose theii* getting 
one big thing for you instead of the usual pile 
of SOX, ties, shirts and slacks. How about our 
finally getting that really great receiver which 
would make all the difference in the world in 
tlie operation of the station? What can she 
say? If youVe akeady packed in a new receiver 
in the last few months and things are still a 
little tender over that extravagance then you 
might as well shoot for one of the new 
transceivers. If you word it right, with just a 
hint of tear in the eye, Tm sure that you can 
get the whole family to kick in and make this 
Christmas one to really remember. Don't for- 
get that people get enjoyment out of giving 
. . . make them happy^ let them give you 
(with your money) something &ig. 

This gambit doesn't work nearly as well 
during the rest of the year and you will prob- 
ably find yourself bribing the XYL with a 
couple of new dresses or a trip to get the okay. 
No, take advantage of all the Chiistmas Spirit 
and use it. 

Too Much 

Luckily I am no longer on the mailing list 
of that sick California nut fann calling itself 
the Anti-Communist Amateur Radio Network. 

{Turn fo page 82) 



73 MAGAZINE 



m 



■:i^M,-:-.»:: ■:■ -s:-: 



i 



i 



. . . your buying 
guide for precision 

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and quality 

electronic 

equipment . . . 



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AMATEURS • EXPERIMENTERS • CITIZENS LICENSEES 

Mail coupon today for your FREE copy of International's 1963 catalog. 



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18 North Lee, Oklahoma City, Okla. 
Rush FREE 1963 Catalog, 

Name 



73 M 



Please Print 



Address. 



City- 



Zone .State. 



DECEMBER 1962 




Richard Van WIckle W6TKA 
643 Aurora Avenue 
Santa Barbara, California 



A Stable, 
Two Meter 
VFO 



ALTHOUGH WE'RE USED to scoot- 
ing arouad the lower frequencies witli ease, 
our wings are usually clipped w hen we venture 
much above 10 meters because, as you've 
probably noticed, the schematics for the VHF 
transmitters usually specify 8 or 24 mc crystals 
instead of a VFO. This is basically because 
there are very few VFO's which have sufRcient 
stability to make them suitable for VHF use. 
The VFO which I am about to describe is one 
of the few which you can use on two meters 
and have reasonable assurance that you are on 
tlie frequency you think you are on. 

The higher in frequency we go, the more 
obvious frecjuency drift becomes. With a 40- 
meter \^FO operating into a transmitter on, 
say, 7100 kc, a drift of one kc is relatively 
minor. However, using a VHF \T0 wdth a 
fundamental frequency of, for example, 8100 
kc, a deviation of one kc becomes 18 ke when 
it gets up to 145.8 mc, since the fundamental 
frequeucy is multiphed 18 times. 

Variations in VFO tube plate and screen- 
grid voltage and temperature changes of the 
tuned circuit are the major causes of \T0 
drift, as most of us know. Shock and vibration 
are secondary causes. Separate the hcalgeiier- 
ating components from the tuned circuit, and 
control the plate and screen -grid voltages, and 
you normally have a stable VFO. 

Remote-tuned VFOs are certainly nothing 
new, yet iht^y have l>een largely ignored in 
VHF work. The VFO shown in the photo- 
graphs and in Fig. 1 has been in use at 



W6TKA for well over a vear. Drift is mini- 
mized by regulation of the 5763 screen voltage, 
and by allowing the VFO to run continiiousl>\ 
A relay (Kl) changes the frequency slightly, 
by placing a 15 mm id silver mica capacitor 
from the 5763 cathode to ground during stand- 
by periods, to ehminate VFO interference witli 
received signals. A crystal -con trolled converter 
and communications receiver are used at this 
station, and the frequency sliift obtained with 
this system is sufficient to put the VFO signal 
well out of tlie bandpass of the receiver. 

Choice of \TO operating frequency is gov- 
erned by the equipment with which the VFO 
will be used. In the illustrated case^ the VFO 
is used with an ARC-4, which requires 6.0 
mc cr>^stals, so the VFO operates on 6.0 mc. 
With an SCR-522, the VFO should operate on 
8.0 mc, and with a Gonset Communicator I or 
II on either 8.0 mc or 24 mc* 

A slight modification will usually have to be 
made to the equipment with which tlie VFO 
is to be used. In the case of the ARC-4, the 
6\^6 crystal oscillator must be modified to a 
buffer stage, simply by eliminating the grid- 
cathode capacitors^ groimding the cathode, and 
feeding the \TO output to the grid of the 6\"6, 

Initial cahbration w as made with a BC-221 
frequency n^jeter, with the VFO and all trans- 
mitter stages operating. The 6.0 mc output was 
cliecked wdth the BC-221 (it goes only as high 
as 18.0 mc) and the various points marked 
on the dial, as shown in the photograph. 
You*U note from the photo that the VFO goes 



73 MAGAZINE 



o 



< 



< 




DESIGN 



:^«^-v*^^1*???^^^STl^i;;v ■■■^-^ ■ •> 



fiij 



DEPENDABILITY 



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only to 147,84 mc, but it could go higlier with 
proper ricljustment of the main tuning capaci- 
tor. Since 1 seldom oi>erate above 147*5 mc^ 
this shortcoming doesn't bother me; if it both- 
ers you, you can easily fix it by moving the 
stator plate of the main tuning capacitor closer 
to the rotor plate. The entire two meter band 
can, by careful adjustment, be covered. 

The dial fs a National ACN, and the larger 
letters (the smaller type is hand-lettered) are 
from the "Artist Aid" sheets sold by many art 
supply stores, and is in this case 10-point Fu- 
tura Demi-bold. The numbers are simply cut 
out and applied, which is much easier and 
neater tlian hand lettering* The original ACN 
dial card was discarded in favor of a thin slieet 
of matte-surface acetate, which takes both 
India ink and pencil nicely, making it idt/ul for 
marking net frequencies and such. 

It is possible to install within the transmitter 
a switching arrangement to allow the choice of 
either VFO or crystal control. Being lazy, I 
chose to arrange to use the VFO also as a 
crystal oscillator, having already converted the 



ARC-4 crystal oscillator into a buffer stage. A 
crystal adapter was built using a twu-crystal 
phenolic socket, pins from a discarded 6V6, 
and a couple of capacitors. The adapter is 
shown in the sch( matic and in the foreground 
of the photo of the complete unit. The remote- 
tuning unit is simply unplugged from the oscil- 
lator chassis, and the crystal adapN r inserted, 
witli the crystal in the adapter. 

The scliematic of the VFO is shown in Fig, 
1, You will note that twin -axial cable— RG- 
22/U— is used instead of two lengths of con- 
ventional coaxial cable, due to less capacity to 
ground from the shielded conductors of the 
RG-22/U, 

Ahliough it would probably be better to reg- 
ulate both the plate and screen of the 5763, 
I have regulated only the screen, and have 
had no indications of frequency change due to 
voltage fluctuations. I use an entirely separate 
power supply for the VFO, which X believe 
helps the voltage regulation. 

A 6800-ohm resistor is placed across L2, in 
an effort to "broadband" the coil, and, sinc^ 
there is more output than necessary to drive 
the ARC-4, it also acts as a swamping resistor. 
The coil (L-2) is one removed from the re- 
ceiver section of the ARC-4, and consists of 25 
turns of #26 enameled wire, on a 5/16 in, 
ceramic, slug-tuned form. If a suitable ready- 
made c^il is not available, a Millen #69041 
can be used as the cf>il form* 

Although the oscillator circuit was built in 
and on a 4" by 25^" by 2" Minibox, as shown 
in the photograph, we would recommend use 
of a 5" by 4" by 3" Minibox, to allow more 
room for the components, especially the relay, 
which was added after the design and original 
construction were completed. 

You will note that no provisions have been 

^1 I '") f 



■HI 



DOJ 



SfLVER 
MIGA 



LI 




1 — U" 

vL' act. ^^ 



■0 



ltf-0 J^ 



dfeHK 



24 
(SLVER MICA) 




OTO GROUND 



CRYSTAL AOAPiTER 
(S££ TEXT) 



HAMMERLUNO MC-20-8 0R 
EQUIVALENT, REMOVE ALL BUT 
ONE STATOR a ONE ROTOR 
PLATE. 



MC-20-S OR 
UNMODIFIED. 



TO GRO 
THROUGH CONT. 

RELAY 



fi J we 



C2* HAMMERLUND 
eOUIVAL CNT, 

Jl- SEE TESfT 

J2- RCA- TYPE PMOf*0 SOCKET 
Kl - 6.3 VAC SPST RELAY. 
LI- L2 -SEE TEXT 

ALL RESISTORS 1/2 WATT 
UNLESS OTHERWISE SPEaRED, 



8 



73 MAGAZINE 



made for keying the VFO. This can be done, 
if you must operate CW on two meters in this 
manner^ by placing a keying Jack in the 
cathode of the 5763; it is not recommended, 
however. 

The tuned circuit is built in a surplus radio 
eqnfpmpnt box, from what equipment I do not 
remember, and measures IO/2" by 6Ji" by 8J2". 
Metal utility boxes measining 10'' by 8" by 7" 
are readily available at low cost^ if a suitable 
box is not at hand. 

The VFO coil, L-l^ is an lUumitronic Air- 
Dux type 1609A. The coil is manufactured 
with a lucite mounting strip attached. For 6,0 
mc operation the entire coil is used; for 8.0 mc 
only 18 of the turns sliould be use^d. The coil 
is mounted on E. F. Johnson Co, #135-501 
steatite cone insulators. 

The tuned circuit twin-ax plugs into the 
oscillator chassis by means of a crystal socket 
modified for use as a plug, and a pin-type fack 
for the shield connection. A standard crystal 



socket is mounted on die oscillator chassis, m 
is a pin-type jack. The shield of the twin-ax is 
soldered to the metal plate of the crystal 
holder- A much neater arrangement would be 
the use of a three-conductor socket and plug. 

The output of the VFO is fed to tlie trans- 
mitter through a short (the shorter the better) 
length of RG'59/U, I found that it was neces- 
sary to detune the output coil (L-2) slightly so 
that it did not over-drive the 6V6 buffer (for- 
merly cr>^stal oscillator) stage of the ARC-4p 
This, however, might not be a problem with 
all transmitters with which tlie V^FO will be 
used. 

A final word of cautions be sure to place the 
tuned circuit box away from all heat generating 
components and equipment^ and away from all 
sources of vibration and shock. Observe these 
precautions, and the construction methods 
used J and we predict that you, too, will have a 
stable VFO for two-meter use. 

, . , W6TKA 



Modifying the Sixer 



THAT powerful little five waiter that has 
made six meters so very popular with 
everyone^ can be modified very easily and 
cheaply for a 50% power increase, simply by 
changing the output tube, the 6AU8 to a 
6CX8, however there is a bite to it. In ad- 
dition it becomes necessary to remove and re- 
place three resistors^^ one capacitor, and 
slightly modify the oscillator coil. It requires 
about thirty minutes work for the average 
ham, more or less. 

Remove both the grid resistors from the 
final, that is the lOK from pin 1 to ground, 
and the 22K from pin 7 to ground. Also re- 
move the 4-7 mmf between pin 3 and pin 7, 
this is the coupling condenser between the 
triode plate and the pentode grid. Also re- 
move the 22K 2 watt resistor from the screen 
grid circuit (pin 8 to lug 2 on terminal strip 
G), Now you are ready to insert the new 
parts. 

Connect a 47K % watt resistor from pin 1 
to ground; and a 47K % watt from pin 7 to 
ground. Now connect a lOK 2 watt resistor 
from pin 8 to lug 2 on terminal strip G. Next 
solder in a 25 mmf ceramic from pin 3 to 
pin 7, Always keep all leads short as passible 
but giving sufficient clearance for all parts. 

The final step is the most complicated of all 
and care must be exercised. Either remove 
two turns from the oscillator coil (L201) ; or 
short out one turn at each end of this coil 



by carefully scraping the insulation from the 
wire one turn down on the coil from each end 
for a space of about 1/16 inch, just enough 
to get a good tin on the wire. Be very careful 
not to disturb any other insulation or more 
than is necessary. Now solder in a short wire 
from the solder lug on each end of the coil 
form to the nearest spot where yoa have 
scraped off the insulation at the end of the 
first turn of wire down from the lug on the 
coil form. This has shorted out one turn of 
the coil at each end. BUT d&n^t do both and 
remove two turns and short out two. The lat- 
ter method is given for those who might wish 
to put the set back in its original condition* 
All of the modification to the oscillator coil 
can be done without removing the coil form 
from the chassis. 

The reason for modifying the oscillator coil 
is that with a 6CX8 in the final socket, it 
will not tune above something around 45 or 
46 mc, due to the increase in capacity of the 
6CX8 over that of the 6AU8; but after mod- 
Ification of the oscillator coil it will easily tune 
to 50 mc with the slug set about midway in 
the coil form. 

As a final step, insert the 6CX8 in the final 
socket, and re- tune the transmitter circuits in 
the same mt;thod as described in the kit manu- 
al. The approximately 50% increase in power 
is well worth the time, effort, and small costs 
involved. , » . K4ZQQ 



DECEMBER IW2 




Modifying 
Lafayette HE-45 



Larry Levy WA21NM 



THERE ARE SO MANY good features 
on the HE-45 that it is hard to find anything to 
modify on it The design is different from most 
transceivers in this price class with the result 
being that the usual modifiLatioiis that 1 would 
make on a transceiver are unnecessarv. The 
transmitter uses 8 mc crystals and the 2E26 
final has more than ample power. The receiver 
is a single conversion superhet having one rf 
and two if stages. The sensitivity and selec- 
tivity are almost communications quality (the 
sensitivity is better than 1 microvolt and the 
selectivity is 3 kc at 6 db). It has an S meter, 
which also measures tlie plate current of the 
final amplifier. It has full PTT, a selector 
switch that allows you to choose any of five 
crystals or a vfo, and a spot switch. The 12 
volt mobile supply is built inside the case, 
making it a cornicle te station for use at home 
or in the car. 

There are a couple of minor improvements 
which will make operation easier. The first of 
these is the addition of a non-spring return 
transmit switch. The spring return transmit 
switch seems to be a holdover from the original 
CB model of this transceiver, and on the citi- 
zens band, transmission should be as short as 
possible and it is unnecessary to have a fixed 
switch. This sometimes does make a long trans- 
mission on the ham bands somewhat uncom- 
fortable because of the rather healthy spring 
used to spring-load tlie PTT switch on the 



TO METER 



flMl 



S METER 




22 K 



f 



COAX 

€ONH 



O Z-5Q 



f 16 1 



microphone. This situation is easily corrected 
by mounting a SPST toggle switch somewhere 
on the panel and connecting it to pins 1 and 2 
on the microphone jack. This will make the 
rig easier to operate and you will still be able 
to use the momentary PTT if you should so 
desire. 

It is sometimes necessar\^ to close-talk the 
microphone to get a high modulation percent- 
age, especially if you nomially speak quietly. 
This situation can be corrected by making the 
following changes; 1, Replace the 56K resistor 
in the plate circuit of V4-B with a 330K resis- 
tor, 2. Break the lead betv^^een the cathode of 
V4B and ground and add a 500 ohm resistor 
in parallel with a .25 mfd between the cathode 
and ground, 3. Replace the 5,6K screen resistor 
of the 2E26 with a 27k 2 watt resistor. These 
changes will considerably improve the modu- 
lation as well as eliminating a slight amount of 
instability in the final 

The dip on the final plate current is so slight 
that it is hard to tell when maximum output 
is reached when loading up some antennas. It 
is easy to change the metering circuit to one 
that measures rf output. To do this, first re- 
move the white and the unshielded blue leads 
from the .51 ohm shunt resistor* The white 
lead is grounded. The blue lead is connected 
to the detector circuit shown in Fig. 1, The 
transmitter is then tuned for maxinunn deflec- 
tion of the meter. A few of the HE-45 j eceivers 
have a tendency to drift during the first few 
minutes of uxicralion* To correct this^ replace 
the condensers that are connected to the oscil- 
lator coil as well as the one used for coupling 
to the mixer willi new NPO condensers of the 
same value. 

While these modifications were written for 
the HE-45, they can also be used on the 10 
meter version (IIE50) or the CB unit as well. 

. . , WA2INM 



10 



73 MAGAZINE 



SSE 



ON 

2 

OR 

6 




Telco "SB" Line 

DEPENDABLE • RELIABLE 




ALL "SB" SERIES 

ARE HOUSED 

IN SAME 

CABINET 



HEAR YE... 

All those interested in SSB 



Telcos New "SB" Series in Action 

SYSTEM 
DESIGNED . . 
FOR YOUR 
• • • • • SYSTEM 



TELCO ANNOUNCES THE Following 



SB 
50 



6 meter heterodyne converter 

allows your 20 meter trans- 
mitter to operate on 6. Only 
5 watts 14mc drive needed. 
Input is 90w AM or CW, and 
125w P.E.P. SSB on SOmcs. In- 
put & output 50 ohms. $85.00 



SB-80 
40-M1 



For the KWM-1. Allows SO 
and 40 Bandswitch Operation 
(next month). 



SB 
50 

C 



A must for S-LINE owners. 
Puts your S-line on 6 meters 
with nothing else to buy. 
Complete Plug-In operation. 
Makes use of converter out- 
put and power supply of S- 
line. Delivers 175w P.E.P, on 
6 meters, using 2-6146's. Built 
in with 201 converter tor op- 
timum reception, and allows 
use of transceive feature. 
Complete with all intercon- 
necting cables. $239^00 



SB 
TWO 



Similar to the SB-50 XMTG 
Converter I but for 2 meters. 

$139.50 



MODEL 
SIX 



Complete 6 meter single side- 
band {USB & LSB>, AM, and 
CW transmitter. 175 watts 
P.E.P, (2-6146 finals) filter 
sideband generation, com- 
plete with built-in VXO. wait 
till you see the low price 
(next month). 



SB 
2-C 



A must for S-LINE owners. 
Same as SB-50-C, but for 2- 
meters. $289«00 



SB-80 
Ml 



Same as the SB-40-M1, but 
converts the KWM-1 to 80 
meters. $175.00 



SB 
40 
Ml 



Converts your KWM-1 to 40 
meter transceive operation, 
Obtains power from the 
KWM-1 power supply and 
provides a clean 175 P.E.P. 
punch. Outstanding TELco 40 
Meter Converter assures ex- 
cellent reception on 40. Com- 
pletely ready to go mobile or 
fixed, Tvith all cables. $175.00 




ALL MODELS ARE AVAILABLE NOW 

%^^ THE SB SERIES AT YOUR DISTRIBUTOR. OR 
ORDER DIRECT 

Ask about the Time Payment Plan. 

Howie Ryder-WI-WGH 
Amateur Sales Manager 

TAPETONE ELECTRONICS U80RAT0RIES IKC. 



Write to: 




n fin St., Wttt NtwWi i5. Hva. 



Tel. (617) 332-1123 



73 Tests the 



rving 



verter 50 



Sideband is a real comer on six meters and 
you seldom lack for a contact on SSB Uiese 
days* As more and more converting transmit- 
ters and complete sideband rigs become avail- 
able commercially it is obvious that sideband 
will ])ecome as popular on six meters as it lias 
on the lower frequencies for it gives the same 
benefits. You can wf)rk out over much greater 
distaiices per given watt of input , . . it is 
simpler to build high power oulput stages when 
you don't have to worr>' about getting all that 
plate modulation power together . . , there is 
mirch less QRM, which has become quite a 
problem on six lately . . . and you can work 
through aurora with it, 

A new piece of gear on the VHF mar- 
ket today is the Irving Electronics Iliveiter 
50- The Hi verter will convert any twenty meter 
AM, CW or SSB exciter into an efficient six 
meter transmitter with no trouble at alL A smiill 
company has to be especially caieful of the 
quahty of their product, or pfft goes its entire 
income, *Tappy" Irving has been scruplously 
careful with his products, and believe me . . . 
it shows on the Hi verter 50. 

The miit can be used with any transmitter 
that is capable of producing from 10 to 100 
watts of 14 mc rf. About six watts are needed 
to drive the unit, so transmitters with more 
than a twenty watt maximum must have some 
sort of carrier insertion control or attenuating 
device between their output and the Hiverter 
input* The instruction manual has a nimiber 
of diagrams for simple resistive pads in case 
tlie user finds he has no way to control his 
driving transmitter output. With twenty watts 
input, the Hiverter wiU deliver 20 w atts on AM, 
35 watts on CW and 30 watts pep on SSB. 

There are no nnnsiial circuits involved in the 
Hiverterj a 6CL6 functions as a grid-plate 
harmonic oscillator, and uses an 18 mc crystal 
that doubles in its oul{mt section. So, if the 
twenty meter exciter is operating at 14*2 mc, 
the six meter output from the Hiverter will be 
14.2 plus 36 which equals 50.2 mc. 

The output of the harmonic oscillator is 
capacity coupled to the cathode of the 5763 
mixer. The output of the mixer is timed to the 
sum frequenc\^ of the Hiverter oscillator and 
the 20 meter exciter to produce output in the 



50 mc range. 

The amplifier circuit uses a 6146 that oper- 
ates class ABl or AB2, An rf choke and a 
capacitor form a series resonant circuit at 14 
mc to eliminate the chances of having a 14 mc 
signal appear at the output of the Hiverter. 
The ampliiier output tunes through a pi net- 
work, so any antenna with 50 to 100 ohm 
impedance should work out just dandy. 

The internal wiring is all done on printed 
circuits, and everything is easily accessible for 
maintenance. The onlv maintenance that tlie 
user will be numing into will be the periodic 
tube checks that are reeonrmiended in the 
manual- 

An external power supply is needed to power 
the Hiverter, and most modem transmitters 
should be able to provide the voltages re- 
quired- Four voltages iu*e needed; 6.3 vac, 600 
vdc, 300 vdc, and —130 vdc for bias. If the 
driving transmitter can't supply these voltages, 
a supply such as the Heath HP20 can be used 
or a supply can easily be built. 

Tuning up is pretty simple with only three 
controls: mixer, amplifier, and antenna. Of 
course the driving transmitter must be pre- 
tuned on twenty meters before its output is 
fed into the Hiverter. 

We drove tlie Hiverter on all three modes 
with a 200-V that was adjusted to produce 20 
watts of rf on 14 mc. We got the maximum 
output claimed for the unit with no troul>le at 
alL On SSB, the output, measured with a Gavin 
bridge was thirty watts on voice peaks. We 
also got the full 35 watts on CW, and 20 watts 
on AM. In the course of testing the unit many 
stations were worked on all three modes on six 
meters. All the reports we got ranged from 
five by sixes to five by nines. Modulation re- 
ports were excellent. We experienced no 
trouble at all even when we overloaded the 
Hiverter input for short periods. 

The Hiverter 50 is a heckuva lot of fuii to 
use, and it is a simple way to get a good SSB 
signal on six without having to buy a mess of 
new equipment. The Hiverter should make 
quite a Christmas present . . . it's inexpensive 
($99.50 complete) » efficient, and fun to hook 
up and use. We sure enjoyed it, 

73 Staff. 



12 



73 MAGAZINE 



Here 's the Hg yifu 've been waiting for 

Ctegg 's new 7H0R W Transceiver 

for 6 Meters, 
Astonishing performance , . . Priceii right i 



i 




Fixed station or mobile, this little power package reflects all the 

advanced engineering and design features that have made CLEGG 
the ''most wanted'' gear in the VHF field. 

Talk about performance , . . listen to this: Fifty solid watts on 
both AM and CW; high level modulation willi full speech clipping 
to give you famous CLEGG "Talk Power"; true transceiver opera- 
tion with tuneable osciliator in the receiver serving as the VFO 
in the transmitter; provision lor keying the transmitter. 

A low noise double conversion super-heterodyne receiver com- 
plete with BFO and ANL provides maximum selectivity and sen- 
sitivity with stability equal to the exacting requirements of SSB 
and CW; separate power supply, modulator for 115V AC opera- 
tion. A fully transistorized power supply/modulator for 12V DC 
available soon. 

And best of all, this rig is priced at a level that every ham can 
afford. Place your order with your distributor today. Deliveries 
start late in November* 



4nd ken's Me fw y^u VHF sMebandersi 



9 



It's the new CLEGG VENUS six meter trans- 
ceiver for SSB, AM or CW! Once you've used or 
heard this rig you'll appreciate the engineering and de- 
sign "Know-how*' that made it possible. 

Here*s what you can expect: A superbly engineered crys- 
tal lattice filter, SSB transmitter of greater than 120 
watts PEP input; amazing frequency stability, VFO con- 
trolled by the receivers tuneable oscillator; full power 

input on CW and a substantial signal on AM phone. There 
is also output provision to drive a KW linear final. 



In the receiver section a double conversion, low noise 
sLTper-het of extreme sensitivity and selectivity, with 
crystal lattice filter and product detector provides flaw- 
less reception of sideband, AM phone or CW. A 115V AC 
power supply of adequate capacity is a separately mounted 
unit which can be installed at any convenient distance 
from the transmitter. 

This rig, too, is priced within reach of every ham. Watch 
for it at your distributors late in January, Place your 
order now to be sure of early delivery. 




And here's a winner and STILL champion in it's class! The famous 
Clegg 99*er, six meter transceiver favorite of thousands of VHF 
hams is small in size, low in price and tops in performance. 

The 99'er offers operating features unequalled in far more costly 
gear. The double conversion super-het receiver provides extreme 
selectivity, sensitivity and freedom from images and cross modu- 
lation. The transmitter section employs an ultra-stable crystal 
oscillator which may also be controlled by an externa! VFO. An 
efficient high level modulated 8 watt final works into a flexible 
PI network tank circuit. A large S meter also serves for trans- 
mitter tune-up procedure. 



^f 



LABORATORIES 



DECEMBER 1962 



504 ROUTE 53. MT. TABOR, NEW JERSEY 

OAkwood 7-6800 

13 




ii 




ing 



Good news travels fast. And if youVe been listening 
to local or DX bands you know that Gonset has come 
out with a new single side band transceiver that's 
everything you Ve been waiting for I 



the mail" 



Of course you want the facts on the new Gonset GC- 
102, so here's the scoop. Whether you want to operate 
I at© ly ? ^* barefoot or with shoes, the GC-102 is the best SSB 

transceiver you can buy! 




Coupled with the 
Gonset GSB-201 Lin- 
ear Amplifier, the 
GC-102 gives 1500 
watts P. E.P, input. 



Because the Gonset 
GC-102 receiver uses 
transistors and "hy^ 
brid" tubes, it oper- 
ates from 12 volt DC 
with a minimum 
power drain! 




ONLY THE GONSET GC 102 SSB TRANSCEIVER GIVES YOU ALL THESE DELUXE FEATURES! 



• Mechanical filter used to generate side band. 

• All bands, 80 through 10 meters, in basic 500 KC 
segments. 

• 2-speed concentric dial drive with "coarse" tuning 

ratio of 20:1 (50 KC/revolution) and "vernier" tuning 
ratio of 100:1 (10 KC/revolution). 

• Power input to final: 180 watts P.E.P, 

• Receiver features dual conversion. 

• Semi-digital dial presentation with 10 KC major divi- 
sions, 2 KC minor divisions. 

• Highly stabilized VFO. 

• Designed for mobile and fixed station operation. 



Separate AC and 12 volt DC power supplies. 

AC P/S forms pedestal for transmitter to match 
appearance of GSB-201 Linear Amplifier. 

"Edge-lighted'* dial and illuminated ''S*' meter, 

100 KC Crystal calibrator built in. 

Transceiver tunes WWV U5 Mcs) for calibration pur- 
poses. 

High voltage power supply is used only in ^'transmit'' 
mode. 

VOX and speech amplifier sections are completely 
transistorized. 



For the Gonset distributor in yonr community consult list on tJie next page. 

CS-OlSrSET 

DIVISION OF YOUNG SPRING A WIRE CORPORATION 
801 SOUTH MAIN STREET. BURBANK. CALFFORNIA 




14 



73 MAGAZINE 



FOR FULL INFORMATION AND DEMONSTRATION OF GONSET QUALfTY COMMUNICATIONS EQUIPMENT 

WRITE OR VISIT ANY OF THE FOLLOWING DISTRIBUTORS 



EAfTltN STATES 

iUBAMA 

BIRMINGHAM 

James W CUrsf Company 

1713 ?rtd Ave S^tim 

CONNECTICUT 

HARrrOFED 
Dressier Electronics 
325 TruTTibuM Street 
Hairy ol Karlfcrd, Inc. 
100 Hi£^ Street 

NEW BRITAIN 
Unlversat R^idio 
63 East Ha\r\ Streei 
NEW HAVEN 
Radio Shdck 
230 Crown Strict 

NEW LONDON 

Aihens Etfctrtinic^ Sup., Inc. 

511 Broad Street 

DeMambfC ^ati^o 

334 Broid Street 

STAMFORD 

High Ric}£e Rd. 

WATERBUftr 

Bond Rjd<& 

439 West M4in Street 

WEST HAVEN 

Alliens Electronics Suppty 

&7Q0r3n|e Stff«t 

WEST HARTFORD 

Radio Shjck 

39 South Main Street 

WESTPORT 

Music Systems of Westport 
PO!it Road 

fifSTfllCT OF COLUMBIA 

WASHIMGTQN 

Electronic Whclesaie:St Inc. 

23^5 Sherman AvenuSt N.W. 

FtOIIIDA 

MIAMI 

Electronic Wholesalers, Inc. 

9390 N.W. 27th Avenue 

OltLANfK) 

Amateur E9#^£trOnic Simply 

23 Aj^lei PAtk Shop. Ctr. 

TAfiMPA 

Kinkade RatiiO Supply, Inc. 

t^l§ Grjnif Central Avenue 

MAINE 

AUBURN 

Radto Supply Cd. 

2A Crass Street 

BANGOR 

R^dici Sen^ice UH. 

23 Ptlm Street 

POflTlAND 

Radio Service L^b 

1004 Congress Street 

MARYLANO 

BALTtMDRE 

Amateur Radio Cen!**r 

2203 N, Fulbn Avenue 

SALISByRY 

Standard Electronics Co.^ Inc. 

3G1 Snaw HIM Road 

TOWSON 

BkjfnesviUt Eteclronics 

1631 E. Joppj Road 

WHEATOH 

Electrpnfc 0is1r^bMtors. Int. 

11324 Fern Avenue 

MJiSSACHUSEnS 

BOSTON 

Cramer Ekctrarrics 

111 Boylston Street 

D«Mafnbr« R^dio Suppler Co. 

1095 Cofnmpnwealth Avenue 

lifayelte Radio 

110 reHerat Stf««t 

Raijio Shack 

730 Comm^nweaNh Avenue 

BRAIMREE 

Radio Shack 

Shopping Center 

BROCKTON 

p^^Mpcnbro Radio 

1S39 Mair^ Street 

BUZZARDS Ui 

fiuf7ards flay ElentrpnicS 

1§6 Mairr Street 

FALL RIVER 

Haddad Electronics 

121 Pine Street 

HAVlRHru 
Vallejr Electrontes 
201 Winter Street 

HYANNtS 
DeMantbro Ridio 
223 Barnstable Road 
LAWRENCE 
Atco Electronics 
3 Weicptt Stieel 
DeMarnbro RidiO 
194 iroadwair 
LEOMmSTER 
DeMarritjfo Radio 
760 Sfsuth Mam Street 

NEW BEDfOaO 
E. A. Ro£S Co. 
1663 Purchase Slre*t 

IWEDFORD 

0£Minibro Radio 

135 Mystic Avenue 

N. WESIPORT 

DeMambro Radio 

§S QAR Hwy., State Road 



READING 
Graham fUdJQ 
SOS Main Street 

SALEM 

DvMafnbro Radio 
2S0 Highiand Avenue 

SAUGUS 
Radio Shacfi 
ShoppLnK PI a/a 
SPRINGFIELD 
deMambro Radio 
269 Spring Street 

WORCESTER 
Radio Maintenence 
SO Ttioma'S St, 

DeMambro Radio 
222 Summer Street 

NEW HAMPSHIRE 
CONCORD 
Evans Radio. Inc. 
P, 0. Boi 312 

DOVER 

tleNlifnbro Ra4ia 
3 Hale Street 

KEENE 

DelAambro Radio 
300 West Street 

MANCHESTER 

beMambfo Radii» 
130i Elm Street 

POtTSMOUTH 

Rackrr^fttiam Electrie 
377 Court Street 

HIW JERSET 

CAMDEN 

Radio Electric Service Co« 

513 Cooper Street 

MOUIMTAINStDE 
federated Purchases. Ine, 
1021 U. S, Rte. 22 

PARAMUS 
Lafayette Radia 
182 Route 17 

PATERSON 
National Erectranics 
276-t7ih Avenue 

UNIOH CITY 

Nidi ICO, Inc. 

2fll2 Hudson BauEevard 

NEW TOflPC 

A L BANT 

Fort Orange Radio D^st. Co. 

904-916 roadway 

AMSTERDAM 
Adirondack Radio 
laS We^t Ma.n Street 

BUFFALO 

Gene»e Radio & Parts C$, 

2550 Oelawife Avenue 

CORTLAJND 

Wincheii Electrflnics 
6S-$7 Clinton Avenue 

ELM1RA 

ClremLin^ ElectronicSp fnc. 

403 E. Third Stfeet 

FREOONIA 

Barker Hitl>e«f Inc. 

27 water Street 

iAMAJCA 

Ha rr If on Radio 

144 24 Hillside Avenue 

La Fayette Hatfio 

165 Wl liberty Avenue 

MINEOLA. LI. 
Arrow Electronics 
525 Jericho Ttirnpib^ 

a*£W YORK 
Arifii-v EtectronFcs 
65 Cortlandt Street 

Harrison Radio 

225 CreerrMicN Street 

Harvey Radio Co,, ^nc. 
103 West 43rd Street 

Terminal Hudson Radio 
236 West 17th Street 

ROCHESTER 

Rochester Rad^o Supply Co. 

600 Ea&t Matn Street 

KORTH CAROLINA 

ASH£VllU 

ffttk Radio & Supply Co., Inc. 

38 Biltnwre Avenue 

CKARLORE 

DiKte Radio Supply Cornpany 

1900 BarTiwall Street 

RALEIGH 

Southeastern Radro Sup. Co. 

4U Hillsboro Street 

OttiO 

ASHTABULA 

Morrison's Radio Supply 
331 Center Street 

CINCINNATI 
The Mytronic Co* 
2145 Florence Avfftue 

SteihbefK'Sp Inc. 
633 Walnut Street 

CLEVELAND 

Bernot> :Fray Service, Inc 

ailS£a$.t 21st Street 



Broadway Electric Supply Co. 
£209 BroadHriy, S.E, 

PiDoeer Electronic Sup. Co. 
5403 Pf osp«ct Avenue 

Radio & EtectrOflic Parts Cor|}. 
3235 Proif^cl Avenue 

COiUMBUS 
Universaii Service 
114 North Third Street 

OATTON 

Cusitc^m Electronic^H tnc. 

1919 South Brown Street 

Srepco, Inc. 
314 Leo Street 

DOVER 

Southeastern EFectranics 

Spec^ahsts Co. 
203 N. Tuscaravvas Avenue 

FREMONT 

Swartilander Radio, Ltd. 
1524 Oak Ha r tor Road 

L0RAJN 

Pione«r Eiectrn^nic Supply Co. 

1^48 flroidway 

MARION 

flell Radio SuMty 

527 N Mam Street 

STEUBENVILLE 
D & R Radio Supply 
2 lb South Third Street 
P, 0. Box §70 

TOLEDO 

Seiectroncc Supplies, Inc. 

3IB5 Bellevue Road 

Warren Radio C{>. 
1002 Adams Street 

PENNSVLVANtA 
ALLENTOWN 
A. A. fetersn Inc. 
231 N. 7th Street 

AITOONA 

Aitoona TV Supply. Inc, 

1720 Union Avenue 

ELKINS PARK 

A. G. Radio Parts Co. 

939 Fownship Lff^E 

PHILADELPHIA 
Alnu] Rad»<} Ooflnparry 
913 Arch Street 

PET1S8URCH 
lydings Company 
933 Liberty Avenue 

PGTTSVILLE 

Moyer EJectranics Supply Co, 

330 East Norwegian SUtit 

HEADING 

George 0. Barbey Cc, Inc. 

333 North 4!h Street 

WVNCOTE 

Hfjw^ird C. Buerger Co., Inc. 

Rice^s Mill Rd. & Glensjde Ave. 

RHODE ISLAND 

CRANSTON 

Radio Shack 

1301 Reservoir Avenue 

PROVIDENCE 

DeMambra Radio 

1292 Westminster Street 

Wp H. Edwards Co. 
Hi Hartfoiif Avenue 

TiNHfSSEE 

NASHVILLE 

|lectf« OistriiNitinf Company 

1 914 V^ett End Avenue 

VERMOMT 

BURLlNCTOfV 
Radio Service Lab. 
703 Pine Street 

ST. JCHNSBUHY 
OeMambro i?adici 
52 Portland Street 

VIRGINIA 

ARLiNGTON 

Key Electronics^ Division 

Indu&try Servfces, Inc. 

100 South Viayni^ Street 

NORFOLK 

Pnest Electronics, Inc. 

643 i TideiN'ater Drive 

WEST VIRGINIA 

CHARLESTON 

Chemcity Electronic Oist. 

1637 Fotlrth Avenue 

HUHTJAGTQN 
Elytron ic Supply, Inc. 
222 S«ver}th Avenue 

CiitrtAi STATES 

ARKANSAS 

TEXARKANA 

Lavender Raifio & TV Sup. Co. 

522 E. 4th Street 

GOLQRADd 

DENVER 

AiidtQ Products Sales COi 

123Jr-lSth Street 

ILLINOIS 

CHICAGO 

Aiiit^d Radio Corp. 

IPO H, Western Avenue 

Amateur Eiectronlc Supply 

64 W N. Milwaukee Avenue 



Green Mill Radio Supply Co, 
MS West mill Street 
Newark Electronics Corp, 
2?3 W. Madison Street 

MOLtNE 

Loffren Dtstri&utiire Co. 
1212 Fourth Avenue 

PEORIA 

Klaus Rattio ft Electric Co. 

403 E. lake Street 

Selectr^nics Supplies, inc. 
sot S. Adams Street 

ROCKFORD 

H i H Electronic Supply, Inc. 

^0G-!)10 Ki^hwaukcB Strt^el 

INDIANA 

CHfSrERTON 

Northwest Distributini CO, 

P. 0. Boi 7 

EVANSWILLE 

Cist r up s Radio Supplies 

1014 W. Franklin Street 

H^DIANAPOLIS 

Graham Electronic Supply^ Inc 

122 S. Senate Avenue 

Van S ckie Radio Sucipiy Co, 

4131 N. Keystone Avenue 

UARIO^t 

Myers Radio Suppty 

lis i 17 West 22nd Street 

SOUTH tEfiO 

Coifai Company, lnc« 

747 So. Michigan Street 

IOWA 

COUNCIL BLUFFS 
Worid fladio lab. 
3415 West Broadway 

PES MOUSES 

Radio Trade Suppiy and/Or 

Amateur Radio Center 
1224 Grand Avenue 

SIOUKCiry 

Two* Way Radios, Inc, 

R. R, fZ 

KAHSAS 

WICHITA 

Amateur Radio E^rtitpfncnt Co. 
1203 East Doug! as 

SALINA 

Etectrontcs. Inc. 
227 No. Santa ft 

KENTUCKT 

LEKINGTON 

TelRad Electronics, Int. 

1401 Oc la ware Avenue 

LOUISVILLE 

Mobile Co rfrmuni cations, rne. 

Bowman FieEd 

LOUISIANA 

NEW ORLEANS 

BqW RadiD Supply Co, 

2625 Tuiane 

Crescent Eiectronic Supply 

537 South Cfaib-orne 

SHREVEPORT 

Ports Electronic Parts Co, 

2423 Southern Avenue 

MrCNIGAH 

ANftARBOR 
PUfclme Radio 
321 E. Hoover St/eet 

OHROIT 

M. N. Duffy A Co. 

2040 firand River W. 

Radio Supply ^ Engr. Cc 
90 Selden 

Reno Radio Company 
1314 Broadway 

FLfNT 

Shand R^dio Speciatties C0» 

2606 Leith 

KALAMAZOO 

Warren Radio Company 

1710 S. Westnedge 

MARQUETTE 

Northwest Radio of ^lichigan 

3(910 W. Washington 

MUSKEGON 

Eicttrcinic Distributors, Inc. 

IB<15 Peck Street 

MJiNESOTA 

DULUTH 

Northwest Radio of Dululh 

123 East Is! Street 

MINNDIPOLIS 
Lew Bonn Company 
1211 li Sa^te Avenue 
ETectffinic Center 
to? -3rd Avenue 

MISSOURI 

BUTLER 

Henry Radto 

an N. Main Street 

sontu 

Norman Electronics 
402 Walt Street 

KANSAS CITY 
Burstein^AppFebee Co. 
1012-14 McGee Street 

ST. LOUIS 

Walter Aslie Radio Co. 

1125 hne Street 



NEW MEXICO 
ALBUQUERQUE 
Radio EayipTienT Co. 
523 Centrai Avenue 

MORTK DAKOTA 

Ml NOT 

John Iverson Company 

216 Second Street, S.W. 

OKLAHOMA 

lav; TON 

Reynoids Radio Supply Co. 

90a ^ B'^ Avenue 

OKLAHOMA CITV 
Cnneral Electrortic 
1032 Ciassen 

TULSA 
Radia, Inc^ 
30130 S. Main 

SOt^TH DAKOTA 

WAIEfliOrtN 

Burf hardt Radio A Supply Co. 

TEXAS 

AMARILLO 

R & R Electronic Supply C0» 

707 Adams Street 

CORPUS CHRISTI 
Electronic Equip. & Ertir. Co^ 
Box 3687 

DALLAS 

Amateirr Electronics 

2S02 Ross Avenue 

HOUSTON 

Buiacker Ei^ectronk Equip. Co. 

1216 West Clay 

Citbert Company 
^301 N. Mafn Street 

Madison Electronics 
1508 McKinney Street 

SAN ANTON CO 

Radio A Television Parts Co. 

IS2fl W. St. Mary's Street 

UTAH 

SALT LAKE CITV 
Manwill Supply Co. 
2611 South State Street 

WISCONSIN 

U CROSSE 

Communications Equip. Co. 
SU State Street 

KEIIOSHA 

Chatter EJectfonic Supply Co. 

2012-52nd Street 

MILWAUKEE 

Allied Radtoof Wtscortslit 

5314 N. Port Washmgton Rd. 

Amateur Electronic Supply 
^B22 W. Lisbon Avenui 

WESTERN STATES 

ALASKA 

ANCHOJ^AGE 

Yukon Ra&iQ Supply^ Inc^ 

P. 0. BD3t 406 

ARIZONA 

PHOENIX 

RadiQ Parts of Art^oni 

214 So. nth Avenue 

Southwest ElectfOPiic Dt vites 
129 E, Jeffefson, 
Paaoi3751 

CALIFORNIA 

fiURiANK 

Kagerty Radio Supply 

2926 W. Magnolia Slvd. 

euRllNGAME 

Amrad Electronrcf 
999 Howard Avenue 

EL MONTE 

Htmball & Stark 

709 South Tyier Avenue 

tNCLEWQOO 

Acprn Radio & Electronics 
473B West Century Blvd. 

LONG BEACH 

Scott Radiio Supply Co, 
266 Alamitos Street 

LOS ANGELES 

Henry Radio 

11240 W.Olympic Bivd. 

Radio Product Sales Co* 
1501 So. Hill Street 

MANTECA 

Fulton Electronics 

IfiORTH HOUYWOOO 

Arrow Sales, inc. 

7035 Laurel Canyon Blvd. 

OAKLAND 

El mar E fee Ironies 
140-llth Street 

ORANGE 

Robinson Etetlronfcs 
922 West Chapman 

PALO ALTO 

Zack Electronics 
654 meh Street 

PASADENA 

Oow Radio. Inc. 
1759 East Colorado 



Com-Ce rater 

2134 N. Carey Avenot 

RIVERSIDE 

Mission Kam Supplies 
S472 Mission Blvd. 

SACRAMEI^TO 

Calamar El^ectronics CO, 

2153-A Fulton Avenue 

Sefectronics 

4113 Franlilin 8lvd» 

SAI^ CARLOS 

Fortune Eieclronics Corp» 

^30 El Camino Real 

SAN DIEGO 

Western Radio & T.V. Supply 

1415 India Street 

SAN FRANCISCO 

Amrad Supply, Inf. 

3425 Balboa Street 

San ffanctsco Radio Supply 

1^0 Market Street 

Zaci< EleitfOftics 

1424 Market Street 

SAN JOSE 

Quem^ni Indust. El6ctrOnrcS 

16 1 North San Fernando 

VAN NlfYS 

ValTey Efeclronii: Scrpply 

17047 Sherman Way 

OREGON 

ALBANY 

Oregon Ham Safes 

409 West IstAvenua 

WASHINGTON 
EVERETT 

Pringie Radio Wholesale 
2101 Coiby Avenue 

OLYWPJA 

Co I son Communlcatiqrts 
4553 Stewart Street 

SEATTLE 

Bad fa Supply Co, 

6213-13th Avenye, So, 

CANADA 

ALBERTA 

EO MO NT ON 

Radio Supply Co.. Ltd. 

lDia4-I&4lh Street 

Sacker Elettronics Co., Ltd^ 

I0235-I03rd Street 

iRtriSK COLUMBIA 

VANCOUVER 

Taylor Pearson & Carson Ltd, 

1006 Richards Street 

MANITOBA 
WINNIPEG 

LeeSern £ Company Ltd^ 
341-347 Wiifiam Avenu^ 

NEW BRUHSWICIC 

MONCTON 

Lewi 5- Price TV Co.. Ltd, 

IS Mount Hoyal Blvd. 

NEWFDUNDLAitO 
ST. JOHNS 

Electronic Centre, Ltd, 
90 Campbell Averiue 

NOVA SCOTIA 

HALIFAX 

Consolidated Suppty CO-i Ltd, 

a§ HQliii. Street 

OltTARIO 

DOWfiSVIEW 

Alpha-Aracon Radio Co., 114, 

555 Wilson Avenue 

FORT WILLIAM 
Lee-Bern i Company Lid, 
105 Simpson Street 

HAMILTON 

Crawford Radio 

119 Jotin Street N, 

LONDON 

C. M. Peterson Company* Lld> 

575 Dundas S'reet 

NIAGARA FALLS 

Niagara TV Supply Co. 

1525 RIaift Street 

NORTH BAY 

JohnsQit Electric Sitpply COt 

tJS Mc^ntyre Street, East 

TORONTO 

Electro-Sonic Supply Co., Ltd. 

543Yonge Street 

QUTREC 

MONTREAL 

Electronic Tube Co.^ Ltd, 

464 McGi II Street 

Payette Radio Co., Ltd. 

730 St. James Street, W. 

SASKATCHEWAN 

SASKATOON 

Radio Supply Co., Ltd. 

561 Second Street 



DECEMSER 1962 



15 



Tom Lamb K8ERV 
1066 Lorchwood Rd. 
Mansfteld, Ohio 



A New 
Look at 
The Alternator 




THE ADVANTAGES of the alternator 
are not new to most mobile amateurs. Unfor- 
hmately their high cost usually Umits their nse 
to those who can obtain used machiiies from 
trucking companies, or from tlie police. 

Motorola is now making all electronic 30 and 
45 amp alternator systems that are ideal for 
amateur use. This new equipment is lights com- 
pact, easy to install^ and costs only about one 
dollar per amp! The solid state regulator elim- 
inates all regulator noise. 

One of the major problems with the con- 
ventional dc generator is its complete lack of 
output at idle* While plenty of power may be 
produced at highway speeds, the average out- 
put in city driving is very marginal^ and com- 
pletely inadequate to support that new 100 
watt mobile rig! Let's look at the reasons for 
this performance. 



A,C. GENERATOR 




CONDUCTOR 
LOOP 



D.C, FIID 
EXCITATION 




A ROTATING FiaOAROUND A STATIONARY CONDUCTOR 
PRODUCES AN A, C, VOLTAGE TO THE LOAD 

Fig. t 



* 

AH common generators generate a no-load 
voltage that is directly proportional to the 
rotor's speed. To obtain a given voltage at a 
very low speed requires that the rotor have a 
large diameter and contain many turns of 
wire. But many tuins of (fine) wire will not 
produce high output current, and a large rotor 
may spin the wire out of the rotor slots at high 
speeds. The practical speed range of a dc auto- 
motive generator i.s limited to about 1400- 
12000 rpm. The pulley ratio must of course be 
set for the high speed limitations, giving in- 
sufficient speed at engine idle. 

Now let's see how the alternator overcomes 
these speed limitations. Since no internal com- 
mutator is needed in an alternator, the machine 
can be built 'inside out.^ That is, the field is 
placed on the rotor, and the load winding 
(armature) is on the outer shell, or stator. 
Fig- 1 illustrates this rotating field construction. 
Notice first that a single Hght field coil is 




2009 4000 AOOO 

AUEflMAfON SHAFT RFH. 

PIS 1 



lO|M>0 



16 



73 MAGAZINE 



wound around the sliaft, not along it, and thus 
cannot spin off at high speeds. This single 
cliange allows the alternator to spin much 
faster than the generator, allowing it to pro- 
duce more power at low engine spcLds. The 
Motorola units \mI1 generate 5-20 amps at idle, 
and full power by 20 niph! (See Fig. 2,) 

The rotating field construction provides 
other features. The rotor has only two soldered 
connections, compared to 28 in a generator. 
The three amp maximum field current can be 
carried by ver\' small shp-rings and brushes, 
reducing the unit's size. The load current does 
not pass through any moving contacts. These 
features plus good dynamic rotor balance 
should give the alternator long care free life. 

Regulation 

Both s\stems use an external rei^ulator to 
keep the output voltage constant and to pro- 
vide system protection against overload* Tlie 
generator's regulator has three relays: a cut- 
out rela} to pre\ ent the batterj from discharg- 
ing back through the generator \^*hen the motor 
is stopped, an o\ er current relay to protect 
the generator, and a voltage sensing relay to 
prevent system over voltage. While this 
mechanical equipment works fairly well, its 
vibrating relay contacts cause a high-frequency 
hash that is discouragingly difficult to filter. 




ISOLATION 
DIODE 

DC 

OUTPUT 



AUX TEIMINAL FOR 
FIELD EXITATIOM 



ROTOR 
WINDmC/^^ 

DC EXCITING 
FIELD 



Fig. 3 



R« 



R* 




GROUND 



FiaDTERM. OF 
ALTERNATOR 



MOTOROLA SEMI-CONDUCTOR VOLTAGE 
REGULATOR (Complete Circuit) 

Fig. 4 



vaTAGE SUPPLY 
AND SENSING 

— C=l 




ANTENNAS IN 





6 & 2 teeter 
Model Mo A 62 
Amateur Net A.62 $33.00 
Stacking Kit AS-62 $2.19 



Patents a I tawed 
and pendmg 



fhe Only Single feed Line 

6 and 2 METER 
COMBINATION YAGI ANTENNA 



another first from 



FiNCO 



ON 2 METERS 

18 Elements 

1 — Folded D I pole Plus 

Special Pliasmg Stub 
1 — 3 Element Co^near Reflector 
4 — 3 Element Colmear Directors 



ON 6 METERS 

Full 4 Elements 
1 — Folded Dipole 

1 — Reflector 

2 — Directors 



See your FINCO Otstributor 
or write for Cataloe 20-226 

THE FINNEY COMPANY 



Dept 20 



Bedford. Ohio 



CUSHCRAFT 



VHF BEAMS 



SINGLE 



DUALS 






BEAMS (A) 

3/4 ^elef 11 element 



1 1/4 Meter 

2 Meter 

2 Meter 

6 M#fer 

6 Meter 

6 Meter 

6 Meter 



11 •Jemerit 
7 «1e merit 

11 •lement 
3 element 

5 element 

6 clemftnt 
10 element 



DUAL STACKS 

3/4 Mfter 22 element 

1 1/4 Meter 22 element 

2 Meter 14 clement 

2 Meter 22 eJement 

QUADS CC) 

3/4 Meter 44 alement 

11/4 Meter 44 el^mttnf 

2 Merer 28 element 

2 Meier 44 clemtnl 



S«« yotir diilributor or writs for compTet* 
Cofcifog No. 116 



Model N 


a. 


Ham N«t 


A430-n 




$ 775 


A220-1 1 




9.9S 


A144-7 




8.85 


A1 44*11 




12.75 


A50^3 




13.PS 


A50-5 




19^0 


A50-6 




32^ 


A50-10 




49M 


A430'1 1 


D 


IBJO 


A220'1 1 





22.90 


A144-7 


D 


21J5 


A144<11 


D 


29.00 


A430-1 1 


Q 


43.00 


A220 11 


Q 


54,50 


A144.7 


Q 


62.50 


A1 44^11 


Q 


76M 



ush 



HiHiittUi ■ H 



411 Httm*4 (towvl 



ra 



A FULL IINI Of 
• AMAfiUP COMMUNICATION 
AHTEHNAi 






DECEMBER 1962 



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^EflULAt^D OUTPUT -VS- r£M^Cn*TVfle 
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HOMtUL SETTING 






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143 VOLTS AT 7S^F 
OUTPUT WE ASSURED 
*T OiJTEnr WITH 






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lEMPEHATURE t*n- 
Fid ■ 



ITS 



ZOO 



The ^lotorola system uses a solid-state regu- 
lator—no contacts^ no hash! No reverse current 
cut-out relay is needed, the rectiKing and iso- 
lation diodes takes its place (Fig. 3). Nor is 
an over-current relay used. Fig- 2 shows the 
aiteniator to be self limiting at high speeds. 
This IS due mainK^ to an effect called "armature 



reaction/' As die outx^ut current increases it 
produces a reaction field that counteracts the 
rotating field, leveling off the output. (Tlie 
temperature effect in Fig. 2 is due to the 
change in coil resistance with temperature). 

This leaves only tlie output voltage to be 
regulated. Fig. 4 shows the regulator circuit. 
When the output exceeds the present level 
(about 14.5 V) the 10 volt Zener diode con- 
ducts, A highly amplified current decreases the 
field current J restoring the proper output. The 
circuit is so good that the system voltage varies 
only ,1 volt from 10 to 70 mph! A thermistor 
is used to match the regulator and battery 
characteristics over a wide temperature range, 
as shown in Fig. 5. 

I have used this svstem in a Renault for six 
months, and consider it the most useful possible 
addition to a mobile installation. 

I am indebted to Motorola, Inc, for the 
technical information contained in this article. 



432 mc Antenna Tuner 



Dear Wa>'ne, 

Took me a long time but I finally inked the 
drawing on the 432 mc Antenna Tuner, It 



works for me^ showing almost unity SWR in 
the coax with a Jones Micromatcli, 

Francis LeBaron, WITQZ 



3-30 mkd 



/*' 



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/iatk from 7' ^/f **'/« 




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73 MAGAZINE 




c 



iDDer 



The CIuaiL'ibox, made by C-Y ElectronicSj 
is a clever little gadget that connects bet%veen 
your mike and your rig and gives you a re- 
markably higli pt'iL tiitage of modulation. This 
little transistorized clipper-filter gives you extra 
gain to make up for any deficiencies of your 
rigj increases the average percentage of modu- 
lation to give you much greater talk-power 
(punch), and keeps your signal within the 
2>5 kc bandwidth best for communication. The 
gadget also works just fine with tape recorders, 
phone patches, and public address systems. 
$24, 95* Write for poop-sheet and complete 
price list of different models. C-Y Electronics, 
3810 East 363th, Willoughby, Oliio. 

C-Y sent us one to try out in the HQ ham- 
shack. The reports were very gratifying. We 
plugged it into every rig in the place and 
botliered everyone who would come back to 
us for a comparison. The universal result was 
that our signals had much greater punch with 
the Chatterbox in the circuit. It made quite 
a differeiice on marginal signals on two meters 
where fading and low signal strength often 
took us out of the picture without the Chatter* 
box. On t\\^ent\^ meters we just sounded a 
little louder than normal * * * as one chap said, 
"Now you sound like you are 50 db over 9 
instead of 30!" 



Letter 



Waytic; 

Why don't you pass alonir to the boys the fact that 
the spEr€ strips in the hamshack TV can easily be mod- 
tlied to tune the FM hand. Pull one turn off the oscilla- 
tor coil for channel six and you*ve got it made. Just 
tune the slug to the proper position onee. In this area 
we have five TV and seven FM siatiotis, just rig:ht to 
a 12 position tuner^ 

Hubert Tomich K7GYH 




HARMON IC/TVI 
V ^.PROBLEMS??? 



T 



**. 



%-rtp 



'•- -v. 





6 METERS 



/ 



TtSABLn LOW-PASS MAVERICK 

The only low-pass fi her designed expressly for 6meteis, 
With 9 individwally shielded sections and 5 stages tun- 
able forming a cornposit filter of unequaied performance. 
1 DB loss. Handles 400 watts PL 35 DB rejection. Size 
S " by 2' by 3 V AMATEUR SET $16,9 S 

MA VH RtCK U WITH POWER MOSiTOR 
Same as above but with 6 meter power indicator cali- 
brated in watts output. Indicator Size 4'' by 4*' by 4^^**. 
Slant Face. Reads 0>SO, 0-400 watts. 

AMATEUR NET $34^93 

2 METERS 

EAND'PASS MODEL 8P^144 

A narrow band-pass filter with 6 mc pass band and 146 
rac center frequency. 1 DB insertion loss. 35 DB atten- 
uation of harmonics. Handles up to 185 watts PI- 
Size 4" .by TA" by 214", AMA TEIR SET SILSJ 

Write fof complete brochures. See your local dealer^ 
Manufacturers of the finest UHF TV Converter 




l\l 



INSTRUMENTS, INC 



DEPOT SQUARE & 
DIVISION STREET 
SOMERVILLE, NJ. 

TEL: 722-6311 
AREA CODE 201 




THREE IMPORTANT 
REASONS WHY 
YOU NEED THE 

NEW 1962 
WINTER 

CMtBOa 

Foreign Listings 
# If your present CALLBOOK (aii outside u,s.) 
is only a year old, over 20% $3.00 
of the 'listings have been 
changed or added! 

• Over 13,000 new amateurs added since 
the Summer, I9t2 issue— another major 
license increase! 

• Completely revised essential data—latest 
international prefixes, Q signals, postal 
info,, airline distances, time chart, etc. 

Now ofi sale at your amateur equipment dealer; If not conven- 
iently located you may order by mail (please add 25<^ for mailifig) 
from; 

RADIO AMATEUR CALLBOOK, fNC. 

Oept. B, 4S44 f ullerton Ave., Chicago 39, EIL 

K, Write for illustrated brochure on exclusive 
, WORLD ATLAS , , . DX GUfOE . . .SPECIAL FULL COLOR MAPS. 



U.S. Listings 

(All K and W calls) 

$5.00 



DECEMBER 1962 



If 



Bu 





Auto Analyzer 



for fun and profit 



Carl Henry 
1910 Kirby Ave. 
Chattanooga 4, Tsnn, 



HOW MANY TIMES have vou said 
to yourself, **if only I had a tachorneter on this 
car**l Never? That doesn't disturb me a bit. I 
am still going to tell you how to build this 
auto anah zer* You really NEED to know. It 
contains among otlier things a tachometer, 
dwell angle meter, engine wall temperature 
indicator, and battery voltmeter. 

Sounds complicated doesn't it? It is. How- 
ever, think of the satisfaction of sa>ing to your 
garage mechanic, **I noticed a slight knock at 
1300 RPM the other day." Or, "the dwell is 
two degrees off^* (whatever that means). 

The whole project was started to replace an 
*idiot light* on my Corvair, and was ended 
when I created this Frankenstein's monster. I 
get quite a bit of cnjovnnent from it however. 
Seldom do I diive Into a service station with- 
out someone saying, 'Vliaf s that thing?" This 
gives me a chance to explain the theory behind 
the circuit, and generally gets me faster serv- 
ice, since they are so happy and grateful to 
learn just how the circuit works. 

An added athaction is that it enables you 
to tune up your own engine. The only addi- 
tional equipment required is a shop manual 
for yom' particular type auto, and a mechanic. 
But on to more important things. 




There are four separate circuits in the auto 
analyzer. Any one or all four can be incorpo- 
rated by the builder into his owii unit. The 
tachometer is of course the most complicated 
circuit. Referring to the circuit diagram, notice 
that tlie taeh input is tied to the high side of 
the points. This makes no noticeable difference 
in the operation of the engine, since the load 
applied by the circuit is very^ light, Resist(3r 
Rl and capacitor CI form an integration net- 
work to integrate the pulses. (Along with all 
true southern boys, T am trying to find a 
segregation network to replace these integration 
networks and offer separate but equal facilities 
to all pulses, but I am unable to get a toe-hold 
on tlic problem as yet,) 



4' 



T 



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J 



K 




|- O— ^ ■ /^ 

^(M^|-0-fe^_ 



T 



Hti*-^^. ii_ 



li 



if*" 
I 



I 



BOTJOtt 



t* I A KS?" * . 



1 



FRia^fT 






•' 



1 



ns t 



t» 



Fig- 1: Auto analyier mounted In car* 



To continue, capacitor C2 feeds the now 
integrated positive pulses to the tiansistor net- 
work^ which is actually a pulse counter dis- 
guised as a tachometer. Observe that Q2 is 
normally cut off by the Ql collector current 



20 



73 MA&AZINE 




THE 



SIX" XMTR CONVERTER 

WORKS LIKE A CHARM!' 

In Norfh Dakota, Soufh Dakota, See It At The John Iverson 

Company, Minot, North Dakota 

Continental Electronics, P. 0. Box 1 6, Sumter, S. C. 



ONLY 
S9995 






drop across R5, and the battery BAl, Ql is 
normally drawing a collector current deter- 
mined by the base bias supplied by the resistor 
E2. When a positive pulse arrives from the 
ignition points, Ql is cut off, the voltage on the 
base of Q2 rises, and the meter reads the 
collect current of Q2. Capacitor CI and C3 
tend to average the pulses and cause the meter 
to read steady, instead of fluctuating wildly as 
you would expect. 

Now, at 5000 RPM, the points of a 6 cylin- 
der auto give out with a pulse repetition rate 
of 5000 divided by 60 times 3 per second. Th's 
figures out to be 250 pulses/second. With the 
proper value of CI and R6, the meter reads 
full scale at this repetition rate. The zener 
diode Dl prevents battery voltage variations 
from affecting the meter reading. 

The other functions of the analyzer are com- 
posed of much simpler ciriults. The batteiy 
voltage is measured by an expanded scale volt- 
meter. This expansion is aceomxilished by 
utilizing the fact that an ordinary silicon diode 
will not conduct on less than 0.6 volt. A divider 
is constructed with Rll and R12, such that 
at 10 volts input to the cii'cuit the voltage 
across the diode D2 is just 0.6 volt. The meter 
then reads from 10 volts to 15 volts over the 
entire scale. This function is not as convenient 
as a battery ammeter, but is some help in 



determining whether your generator is charging 
the batteiy. 

The engine temperature measurement is 
actually a measurement of whether the engine 
w^^U temperature is normal, A conventional 
ohmmeter circuit is used, consisting of RIO (a 
thermistor or temperature-sensing resistor), R9 
(the normal calibration resistor) and the meter. 
RIO is mounted on the engine wall and R9 is 
adjusted to center the meter m the normal 
zone, after the engine is wai'med up. 

The point dwell is measured by an even 
simpler circuit. It works by virtue of the fact 
that the meter will indicate the average con- 
dition of the point circuit (that is, whether the 
points are open or closed). The meter is con- 
nected to the high side of the points by a re- 
sistor (R8) sufficient to allow the meter to 
read fullscale when the points are open. 

When the points are closed, the meter reads 
zero. The meter therefore reads the average 
open time of the points, and is calibrated in 
dwell angle, 60 degrees to degrees, 

Consfruction 

In order to save space, the analyzer is built 
to mount under the dash of an automobile. 
A standard chassis is used, measuring 6X4X2 
inches. The open side of the chassis is used 
as the top, and is mounted against the under- 



OECEMBER 1962 



21 



10 

fa 



1000 2000 3000 4000 50 

iLnihi|iji,iii)\,iii.[jr,ij r.[ii,r,i. 



AQ. 



TSS 



jmr 



20. 



mi 



fe 




Bg, 3; Meter scale used on analyzer-, 

Side of the dash, tis shown m Jig. 1. A special 
meter must be used to fit this type of con- 
struction* This type ul meter is called an "edge- 
wise/' meter. 

Begin the constniction by punching the 
ehassiii as shown in Fig, 2. After punching the 
chassis, mount switch SI. Connect the strap 
and five wires, each 6 inches long to the proper 
lugs on the switch (see Fig, 7). The meter 
may now be mounted* Although a correction 
or read-out clunt can be used with the meter, 
a proper scale is desirable. Fig. 3 shows the 
scale used on my analyzer. This will be correct 
for everything except an engine w^hose RPM 
will exceed 50UO, A 10,000 RPM sc^Ie can 
be substituted in this case. Or you can make 
up a scale to fit your own requirements. Paste 
the new scale over the meter scale, using an 
epoxy resin cement. Other cements will buckle 
with moisture* 

The most difficult part of tlie construction 
is the printed circuit used for the tachometer. 
If you do not have the means of etching such 
a boards or a friend who can do it, you can 
use the perforated phenolic board listed as an 
alternate in the parts Hst. If you use a per- 
forated board, you must of course wire be- 
tween the connections shown in Fig, 7 with 
hook-up wire, Use rivets or eyelets at the 
connection points, and put the hook-up wire 
on the back side of the board. When the 
wiring on the board is completed, mount the 
board behind the meter on % inch standoffs. 
If metal standoffs are used, be sure they do 
not ground any of the wiring. Mount BAl 
beside the board. 

Fig. 4 shows the completed analyser. You 
wiU notice that diere are comiectors mounted 
on the back of the chassis for the input and 
battery cables. These are optional with the 
builder, and should only be used when it 



may be necessary to remove the analyzer ire- 
(iu(*ntly from the car. In permanent install a* 
tions, rubber grommets can be used, and the 
cables connected directly to the analyzer. 

Other components not included on the 
printed board are mounted on two teiTninal 
strips, one on each side of the unit. When 
these components are mounted, the wiring can 
be completed. Two 8-32 bolts are installed 
head down, one on either side of the chassis, 
extending upward. These bolts are used to 
mount the analyzer to the underside oi the 
dash. 

Three cables must be run to place the ana- 
lyzer in operation. Two of these go to the 
engine, and the other connects to the battery 
fuse block, under the dash. Fig, 8 shows the 
method of rurun'ng the engine cables to the 




Fiq, 4; Inside view of the analyzer. 

rear; in this case on a Corvair, The first of these 
cables is a 15 foot piece of RG-58/U coaxial 
cable. Ground the shield at the analyzer end, 
and leave the shield unconnected at the other 
end. The center conductor of the coaxial cable 
connects to the high side of the ignition points 
(the low side of the coil) as in Fig. 9. The 
center conductor goes uito the analyzer circuit 
as shown in Fig, 6, 

The second cable to the engine can be any 
type of two conductor insulated wire, such as 



I 






<S> 



1 



BXTJ 



^ POINTS 






SmPLrtEO DWELL METER QRCUIT 





TO 

REGUUCTEO 
VOLTAGE 
FROM 01 



SlimJF^D BATTERY CHECK ORCUIT 



SIMPLLFnED EN43n^ TEMPERATURE QRCUIT 



FIG S 

Fig. 5: Simplified schematic of the temperature, 

battery, and dwell mefer circuits. 



22 



73 MAGAZINE 



BATTERY 
POSITIVE 



TO R9* 



BATTERY 
NEGATIVE 



TO O ON SI 




TO Rl 



TO BATTI+J 
•■ TO BATrt-l 



CONNECT WITH 
WIRE OH QACK. 



TO METER 




wmmO OF SWTTCH 31 
REAR VIEW. 



TW 



Fig* 7: Schematic drawing of printed circuit 

board and wiring on Si, 




Fig. 8; Photo showing cables in channel to rear 

engine for tachometer and temperature circuits. 

lamp cord. It connects to the thermistor which 
is mounted on the engine block. This thermis- 
tor is a small bead^ about 1/16 inch in diame- 
ter, mounted in a slender glass tube, Vs inch 
in diameter and 1 inch long. To make it more 
rugged, and easier to handle and mount, put 
the thermistor in a brass or copper tube, and 
seal it in place with epoxy. Longer wires 
should be connected to the present thermistor 
wires. I used a brass tube M inch in diameter 
and 2 inches long. A 3/16 inch hole was 
bored to mount the themiistor, and then the 
brass rod was clamped to tlie engine block. 

The thiid cable supplies power to the in- 
strument. One conductor supplies power to 
the analyzer, through the ignition switch^ while 
the other conductor supplies power to the lamp 
in the unit, through the panel light switch. 
Fig. 10 illustrates the method of picking up 
these voltages from the fuse block. None of 
the cable lengths are criticaL 

Calibration 

Refer to Fig, 5 and 6. First of all, the cali- 
bration methods will be given. Then conver- 
sion to 6 volts and positive grounds will be 

discussed. 




MODEL DI-1 

RF 
DISTORTION 

INDICATOR 



# Specifically designed for correct adjustment of 
linear amplifier*, SSB exciteri or transmitting 
converters* 

# Displays RF trapezoid or RF envelope patterns. 
Uses 3'' scope tube with full mu-metal shield. Green 
filter provides unusually sharp display, even in 
bright light. 

# Trapezoid pattern compares detected envelope of 
exciter with RF envelope of amplifier or transmit- 
ting converter. 

• The accessory Two-Tone Plug- In oscillator Model TT-1 
provides the signal when moking adjustments to 
the amplifier or transmitting converter. 

• No modifications or internat attachments to exciter 
or amplifier required. Rear connections provided 
for 50-70 ohm coax lines* 

• Operates 160 thru 6 meters. NO TUNING required. 
Handles any power 5 wotts to 2 KW PLUS. 

• Built-in, hum free power supply for 117 VAC. 

# Comes completely wired and tested, with oil tubes 
and ready to operate. 

Amateur Net Price _ .MODEL Dl-T . , .$99,95 

MODEL n*l.,. $19.95 



ELECTRONICS INC 



424 Cotumbia 



LafayeHe, ind 




DECEMBER 1962 



23 



TO MK3H 

StDC OF 
TOMTS 




THERMrSTCI! 



f?lO 



MOUNTED ON 

EHGINE eUDCK 



TO BAIT 
T>ffOUGH 
IGMITICV^ SW 

TO BATT 
SUPPtTlNG 
PmEL LAMPS 



fia t 



TV 



Fig. 6: Complete sc 

To calibrate the tachometer circuit, you 
must first understand how it operates. Con- 
nected to the points, it is a counting circuit, 
which cornits e\er\^ time the points close. On 
a 4 cycle 4 c> linder engine, the points operate 
twice for ever\' engine revolution; 3 times for 
a 6 cylinder engine, and 4 times for an 8 
cyhnder engine. Remembering this fact, con- 
nect the input of the tachometer to a 60 cycle 
source such as the ac line, (If you use a com- 
mon outlet there may be a shock hazard; use 
an isolation tran^lormer.) Put a 0,02 mid 
capacitor in each side of the connection. The 
ac line will supply 60 counts per second to the 
tachometer. This will correspond to 1800 RPM 
on a 4 cylinder engine, 1200 RPM on a 6 
cylinder engine, and 900 RPM on an 8. Adjust 
R6 nntil the meter reads correctly. 

To calibrate the temperature circuity use 



hematic of analyser. 

the values shown on the scliem;itic to begin. 
Operate the engine until it has reached normal 
temperature. Now adjust the value of R9 until 
the meter reads mid-scale. Color the HOT 
section of the meter scale red. An air-cooled 
engine will heat very quickly when the air 
flow is stopped or reduced. This indicator will 
change into the HOT zone rapidly if the 
engine overheats. 

The same procedure is used witli the battciy 
circuit as with the temperature circuit. A volt- 
meter is placed on the batteiy as an aid to cali- 
bration. When the batteiy reads 12 volts, 
adjust R12 until the meter reads mid-scale as 
before. 

The dwell meter circuit calibration is harder 
in that it is relative to the present condition 
of your points. Tf they are not new, either file 
them smooth or replace and tlien gap proper!} 





Fig, 9; Pho+o showing connection of RS-58/U 

to low sida of coil* 



Fig. 10; Battery pickup on fuse bloct under dash 



24 



73 MAGAZINE 



with a gauge as you would normally do. Then 
adjust tlie value of R8 until the meter reads 
the correct dwell for your ignition system. 
From then on, the pniuts condition is readil> 
apparent by variations in the meter reading. 
You can get a much more accurate check on 
pitted points in this manner. The reading is 
not accurate, however, if the engine speed 
exceeds 1000 RP\h 




iii II 



TV- CAMERA 

BUILT AT 
LOW COST 
DETAILS 



50c 



DENSON ELECTRONICS 
CORP. 



lyuHS I Box SS, Rockvilte, Conn. 



Posiftve Ground Sysfems 

On autos with positive grounds, the follow- 
ing changes must be made for proper opera- 
tion. First, use 2X214 (NPN t\pe) transistors 
in place of the 2N654, Reverse BAl; reverse 
Dl and D2; reverse the meter; and reverse 

6 Volt Operation 

For 6 volt operation you must make tht^sr 
changes: first, eliminate Di and R7; then 
chanu;o the resistor values as shown in the 

parts list, 

* . . Henry 

Pmrts List 

Wattaire and voltage minimuin. 

CI— 0.06 mfd, 600 wvdc, paper tubular 

C2-^.001 mfd, 400 wvdc, ceramic 

C3— 20 mfd, 25 volt, electrolytic 

Rl — 22€0 ohms, V> watt carbon resiBtor 

R2— 18 kilohm (12 volt battery); 10 kilohm (6 volt bat- 
tery), Vj watt carbon 

R3 — 1000 ohms, % watt carbon 

R4^47 ohm, % watt 

RS-^TOO ohm (12 volt battery) ; 3900 ohm (6 volt bat- 
tery)t 1 watt carbon 

R6 — tacbometer calibration resistor; 2200 obm, 1 watt 
for 6 cylinder engine with 12 volt battery 

R7 — 470 obm. 2 watt earban 

R8 — dwell calibration rcBiBtor ; 15 kilohm, 1 watt for 6 
cylinder engine with 12 volt battery and 33 degree 
normal dwell angle, 

R^ — temperature calibration resistor; with air cooled en- 
gine and 12 volt battery, S.2 kilohm. 1 watt- 

RIO— thermistor, OJennite type 51PA1, 100 kilohm, bead 
in prtass probe. Available from Lafayette Radio* 

Rll— 6800 ohms (12 volt battery) : 3900 ohras 6 volt bat- 
tery K 1 watt, 

R12 — battery calibration resistor; 3<J0 ohm, ^A watt for 

12 volt battery- 
Si — slide switch, 1 circuit 4 position, Lafayette stock 
#SW-T4 or equivalent 

^ — 1 milMampere meter, edgewise typei Lafayette stock 
#TM-21 or eauivalent 

Dl — Zener diode. Motorola type lMt2, available from La- 
fayette Radio Corp, 

D2— silicon diode type IN636 or equivalent 

Ql— 2N664 transistor (negative eruiind) ; 2N214 (posi- 
tive ground) 

Q2 — same as Ql 

Cha SI? b— Lafayette #MC-159 or equivalent 

Printe^i board — Lafayette MS-519 or equivalent (alter- 
nate) Perforated board — Lafayette MS-^04 or 
equivalent 

Rivets t eyelets for board) — Lafayette MS-7H2 or equivalent 

Iftttnp — with 12 volt baltery, type #53: with 6 volt bat- 
tery, type #51* either with scx^ket. 
All above listed parts available from Lafayette Radio 

Corp* 



# _ 





^ 



Our New Model 1062 

for 6 & 2 Meters 

This new model will Eive up to 500 watts AM & 
CW linear, up to 1000 watts pep on 6 & 2 with 
a 7034 finaL 60 C*F,P.M. blower. Requires ap- 
proximately 5 watts drive on 6 & 2, Voltage re- 
quired^plate 800 to 2000 at 250 ma, screen 300 
volts, bias — 50 volts* 



Price— $Hi9.95 



less power supply- 
Power supply Slld*95 
Both only %ZUM 



J&D LABS 



73. Hwy- 35 
Eafonfown, N* J. 
[201} 542-0840 



JEFF-TRONICS 

for the finest in Ham 
Military Syrpius 



anil 




AntD-ina Relay, ccra-mh intulatEri, DPDT 15 Amu. tantacts. 
2" X ^" X 1%"* Specify coii valtago* i2V. ilc» 6V. AC, 1 15V* 
AC> $2.50 (1^ 

RF Cable. 10' 3'' lonfl. RG-B U with UG-21 U type N con- 
nector on ©at;h end. 4 lbs. $1.25 each, 10 for SID. 00. 
Audio outfiut trans. SO'JO nhms P-i^ to 4, 8, 16, 500 ohms, 15 
*atts- Good respanit to 15 Kc. 3'^ % 3Va" x 3'/2". 4 lbs. 52.00. 

(2 

Po^er trans. 395- 0-395 V. 



5V. 3A., e.3V. 3.3A. 



200 ma., 
3%' X 4'/2" X 4". 7 ids. $4-00, (3) 
6 BQ5/EL 84 lubes. Brand new, made in Germ any. SI. (HI, 

TA« fotiawinic 2 tf^m* or^ madf f*tr us, io vur tpei^** 
Filame.it trani., 2 windings each 12.6V. I Amp. 2V4" x 2" x 

Power trans. I2SV* 20 ma., 6.3V. 0.6A. 1%" x 2W « I'/t". 

I pounds $1.50 (Looks similar to 4 above) 

Pli^a^i^ rtftfi ampt^ p&siagef and in Oh in add 3% »«ttet 

tax. Any arctfSA fs r^* funded. 
In our new eouitiment deot.. we have in stack Drake 2B re- 
ceivers, New-Trortics **Hustkr/' Notion*fcl receivers. Hvoain 
antenna;^, FinDO anttiniias, Premier chassis &. cabinets, Amv^ap 
Sonoione. 
4791 Memphis Ave., Cleveland 9, Ohio, SH 9-4237 



DECEMBER 1962 



25 



Coaxia 
Baluns 



Larry Levy WA2INM 

THE HIGH LOSSES of coax on the 
VHF and UHF frequencies maVe the use of 
open wire traosmmion hne (ladder line) very 
practical and economical, esi^ecially consider- 
ing the high cost-per-watt on 144 mc and the 
even higher cost-per-watt on 220 and 432 mc, 
Ordinary 300 ohm twinlead will work, but 
the tubular polyfoani is recommended. The 
lowest loss possible can be achieved by the 
use of hidder line. The loss of this line is very 
low compared to coax. At 2 meters, the loss of 
100' of RG8/U is about 3Ji db. The loss of 
300 ohm ladder line is about U db for the same 
length. Translated into power, this means that 
about twice tlie power reaches tlie antenna 
with the ladder line. Losses on the other bands 
are proportional to the frequency. 300 ohm 
ladder line does not seem to be a standard item 
but it is available from Lafayette Radio. Tlie 
cost for 100' is only $L90 (Lafayette stock 
no. WR'125) which is so much more economi- 
cal tlian RG8/U that it would pay to use it 
even if the losses were equal 

Most transmitters are designed to load into 
a 52 or 72 ohm unbalanced line (coax) and 
not into a 300 ohm balanced line. A coaxial 
half wave balun can be used to match the 
ladder line. The baluns have an impedance 
ratio of 4:1, so if 72 ohm coax is used, the 
resulting impedance will match tlie 300 ohm 
line quite well. The impedance can be changed 
back to 72 oluns l>y anotlier balun connected 
in raverse at the antenna end of the line. This 



10 KMTR 



lUMBALtANCEOt 




TO AWT 



•ALUH 



LIUXSEH UN£ 



TO KMTfl 



LADDER UNE 



END BALUN 
CrRE'^UlRED) 




TO ANT 



f L 



is necessary if the antenna is g^unma niatched^ 
etc. If 52 ohm line is used, the resulting im- 
pedance is 200 ohms which will match 200 
ohm twinlead (KT-200, etc.) or be^uns that 
are "T" matched. 

By the use of ladder line and impedance 
matching baluns, the required impedance can 
be obtained with a substantially lower line 
loss than can be gotten with coax, \^'ithout 
investing imy extra money in your rig, you can 
double your ERF on 2 meters (if you are using 
100' of RG8/U) h\' just replacing the coax 
with ladder line. On tlie 432 mc band, RG8/U 
has a loss of approx. 6-8 db per hundred 
feet. The 300 olmi ladder Hne lias a loss of less 
than lM-2 db for 100' of line. This means 
that with RG8/U, only 15-25% of the power 
reaches the other end of 100' of coax. With 
the ladder line, over 75% of the power reaches 
the antenna with the same length of line. 
On a band where there is a power limit of 
50 watts, the power lost in die hne is irre- 
placeable as it cannot be made u^i by incrciis- 
ing the input. Even if it could be replaced by 
increasing the input, power at this frequency 
is expemive to generate and the extra power 
could be put to much better use than heating 
a length of coax. The losses become important 
on the receiving end where there is a fixed 
amount of tube noise (as low as it is) and 
every bit of attenuation by the transmission 
hne reduces the signal-to-noise ratio tliat much 
more. (The same amount of noise and less 
signal) If a weak signal is received at the 
antenna, there is very litde chance diat it will 
be heard if coax is used because of the reduc- 
tion of the useful signal-to-noise ratio. 

If there is a situation where a 432 mc signal 
reaches the antenna at a level that is 4 or 5 db 
higher than the front end noise of the converter 
and 100' of RG8/U is used for the transmission 
line, the signal will not be heard (the signal 
will reach the converter 6-8 db weaker be- 
cause of the line attenuation and will be 1-4 db 
below the noise). If ladder line is used (with 
a loss of less than 2 db), the signal will be out 
of the noise by 2 or 3 db. The example cited 
IB far from uncommon and having a low^ loss 
transmission line will make the difference be- 
hveen no QSO and solid copy many times. The 
advantages are multiphed when low loss lines 
are used on both ends of a QSO. 

The lengths for the various bands are given 
below. 

50Mc.--76^' Icm^ end, 74M" high end 
144Mc,-26)i" 
220Mc.--17r 
432Mc,-8X" 

• , . WA21NM 



26 



73 MAGAZINE 



SIX 







kit only 



$59^^! 




HIVERTER 



50 



LWDtb tttC tJUf*>iC-. t*^ *^ 



6CL6 osc. 
6146 amp. 



5763 mixer 

2 OB2 regulators 



AM — CW 



SIDEBAND extends your range amazingly . . . gives you VOX operation 
. . . nrtakes amplifiers extremely simple for higher power. SIDEBAND gets 
through first when the band starts to open , . , even works through aurora 
flutter. Now you can go on sideband on six meters with the Hiverter wHh 
utmost simplicfty. You'll need a source of 20 meter sideband, the HI- 
VERTER and a power supply. Any of the popular sideband exciters 
or transceivers will give you the ten watts needed for the HIVERTER 50. 
The $29.95 Heathkit HP20 power supply delivers the voltages needed: 
600 vdc @ 150 ma., 300 vdc @ 60 ma., 130 vdc bias, and 6.3 vac @ 
2.65A. 

The HIVERTER 50 will run about 50 waifs PEP input (30 watts output) 
on sideband, about 40 watts input on AM phone and 50 watts on CW. 
You can work that CW DX and ail the transceivers with this unit . . . and 
still be ready when the band starts to open up to blast away on SSB, 

The HIVERTER 50 is available wired and tested, complete with all tubes and crystal, 

less power supply, for > $99.50 

HIVERTER 50 KIT, complete with tubes, crystal and two prewired and tested printed 
circuit modules (very little to do, really), less power supply ,$59,95 



PREVERTER 
50 & 144 




Send tor fft* lilt tf 
mort thin 80 printed 
circuit kits* 



THE BEST PREAMPLIFIERS AVAILABLE 
AT ANY PRICE — TRANSISTORIZED — 
12 volt. NO NEED FOR EXPENSIVE HIGH 

VOLTAGE SUPPLIES — LOW NOISE 
FIGURE— 

6 or 12 Meter model. . .$14.95 post paid. 




DECEMBER 1962 



27 



*?":■:«>:•:■ j-rj:?"?re^'^t??fr-:^-=Si:rJ;5f'-^K'::-:>y--,:;n;5 




Selectivity 




^SiiwS^s^;.. 



■m 



Don Wherry W6EUM 
2121 Grand View Drive 
Camarillo, California 



WITH the addition to our ranks of hun- 
dreds of new amateurs each month the 
time is rapidly approaching, if in fact it is not 
already here^ when it will be nearly impossible 
to carry on a conversation with anyone but 
those with the loudest signals* The only solution 
to that problem, it would seem^ is to utilize 
either greater and greater receiver selectivity 
or some other spectrum saving device. SSB with 
its single sideband and reduced bandwidth char^ 
acteristics has allowed oor receiver selectivity 
to approach the optimum for fone, but let*s 
look at the CW pichne as it stands today, 

A selectivity curve for a CW receiver could 
be obtained which would have a half power 
point (3db) of one to two hundred cycles. This 
bandwidth might be adequate, but let's exam- 
ine such a situation* To obtain such selectivity 
the passband must be very sharply peaked, 
which presents a knife edge center frequency. 



This is great except for one small detail — no 
one could copy the code passing through be- 
cause of the excessive **ringing" of the high Q 
circuits necessary. This means that the nar- 
rowest usable passband must be several hun- 
dred cycles wide at the 3db point to be even 
remotely usable, and even then the ringing 
presents a difficult and tiresome experience to 
the operator. This ringing has been alleviated 
to some degree in the flat top characteristic 
curves of the mechanical filters, and by the 
use of low frequency if strips, but again there 
is a limit to the narrowness of the passband 
which will allow a readily readable signal to 
pass. It becomes obvious, therefore, that some 
new approach is necessary if we are going to 
intprove our lot — which brings us to the sub- 
ject of this article. 

Several years ago a method of improving 
our CW reception was presented which utilized 






+3^30 VOC Q 



Fig* I 



2S 



73 MAGAZINE 




The HAM-M gives you both I 



Right from the shipping carton, the 
HAM-M is ready to use with almost 
any antenna /support structure com- 
bination. That's versatility! 
What's more, our warranty records 
show that the more than 10,000 
HAM-M rotors now in service have 
logged more than 268 million hours 
of service. That's dependability! Of 
course, we've made design changes 
along the way to improve the best, and 

CDE makes a complete tine of the world's 
standard*duty automatic, standard-duty man 



we've made fie!d modification kits 
available for servicing older units. 

At $119.50 amateur net. the HAM-M 
is the greatest rotor value around! 
For technical information, contact Bill 
Ashby K2TKN, Your local CDE Radiart 
Distributor has the HAM-M in stock. 

CORNELL DUBILIER ELECTRONICS, DIV. OF 
FEDERAL PACIFIC ELECTRIC CO., 118 EAST 
JONES STREET, FUQUAY SPRINGS, N. C* 

finest rotors: Ham, heavy duty automattc, 
uaL*.and the industry's only wireless remote 



CD.E 



CORNELL- 
DUBILIER 



heavy-duty manual, 
control rotor system! 



the principle of passing a low frequency audio 
signal from the receiver through a bandpass 
filter, rectifying this ac signal and using the 
dc voltage thus developed to trigger an exter- 
nal oscillator. In this manner the operator was 
hearing the trigj^ered oscillator and not the 
original signal as presented by the receiver. 
This circuit presented an idea which seemed 
to have considerable promise, however the unit 
as described had several weaknesses as some 
of you who tried it foundp They were^ 1 — inad- 
equate filter, 2 — something less than positive 
keying, 3 — tricky to adjust and 4 — no way of 
actually hearing the original signal from the 
receiver simultaneously with the keyed version. 
This latter feature, at first glance, might not 
sound important, but those of you who may 
have tried this device can attest to the utterly 
helpless feeling you experienced when the 
oscillator ceased to trigger and you were con- 
fronted by a deep silence, with no way of 




Fig- I A 



knowing if your contact had drifted up, down, 
or just faded away. 

The unit to be described here is related to 
the original device, but has overcome the un- 
desirable characteristics of its predecessor • 

Looking at the schematic (Fig. 1) I will 
take you rapidly through the circuit operation 
and then go back and comment on the various 
details. The first tube in the unit, VIA and 
VI B, takes the signal as received from the 
receiver and amplifies it through a vei*y nar- 
row passband filter. This filter is placed in the 
plate circuit of the amplifier tubes and consists 
of two high Q inductances tuned to the desired 
frequence by two condensers. The signal is 
then rectified by two diodes in a voltage dou- 
bling circuit with the resultant dc voltage used 
to trigger a flip-flop multivibrator, V2A and 
V2I!. This multivibrator then turns "on** and 
"off' a keyer tube (V3A) which keys a neon 
osciJator, the output of which is fed into the 
grid of V4B, and into the output of the unit. 
The second input channel goes tx? V3B where, 
bypassing the filter, it is amplified and passed 
to the grid of V4A- There it is mixed with the 
output of the neon oscillator and presented to 
the output. It is apparent even by now that 
this device has corrected the major difficulties 
incident to the original modeL 

A more detailed breakdown of this circuit 
is as follows: The first tube VIA and VIB has, 
as its two plate loads, a high Q tuned circuit 



DECEMBER mi 



29 




which is resonatedf in this case, to 500 cycles. 
As yoti know, selectivity is a percentage situ- 
ation, so to get a real narrow passband a low 
frequency signal from the receiver must be 
used. A frequency lower than 500 cycles could 
just as well be used if more selectivity is 
desired — more about that later. The two in- 
ductors used in the filter here are UTC vari^ 
able inductors of the VIC type* These are 
roughly tuned to the desired frequency by the 
capacitors C3 and C4 with the final peaking 
done with the slugs. Any type inductors can 
be used^ but the job of peaking will have to be 
done by padding the condensers and this is 
much harder than turning a slug, A VlC-15 
will tune to 500 cycles with a condenser of 
0.02 shunted in parallel. However if you wish 
to change the resonant frequency to a lower 



value use the formula F =- 



wherp. C 

6.3 V LC 

is in farads and L is in henrys. Remember 
again that the lower the resonant frequency 
the better the selectivity. The inductances used 
in this model are VIC-9 which have a low in- 
ductance requiring a rather large condenser 
in shunt. This lowers the Q somewhat and in- 
creases the bandpass, but even this unit has a 
bandwidth of 90 cycles at the 3db point. 

The audio signal leaving VIB is then fed 
into a voltage doubling rectifiei* circuit 'which 
uses any good diode such as the IN 63 or the 
older 1N34. The diodes are connected to fur- 
nish a positive voltage output. This rectified 
voltage is then smoothed by C6 and fed into 
the multivibrator input circuit. C6, by the 
way, does more than just smooth the rectified 
voltage; the noise spikes from auto ignition, 
vacuum cleaners, etc,^ are effectively taken out 
by this condenser. 

The multivibrator circuit, V2A and V2B, 
is the heart of this unit and as such warrants 
some detailed discussion. Going baek^ if you 
pass a square wave, such as a keyed CW sig- 
nal through a high Q circuit with its high se- 
lectivity you reshape the square wave very 
badly. This is what causes the ringing sound. 



Figure 2 A shows a typical keyed CW "dot" 
after passing through a narrow passband filter 
circuit. This sloping of the start and finish 
shows why it is so diflRcultj if not impossible, 
to directly copy the output of such a filter. 
While the rectified voltage, as fed to the multi- 
vibrator, looks like *'a" on 2Cj if the action 
of the multivibrator can be made to take place 
at some voltage above zero as on line "x" of 
2A and the neon oscillator can be keyed on at 
this point then the tone, as heard, will start at 
*^c" on 2C and stop at "d." This will give an 
output signal shaped as shown in 2B, effec- 
tively eliminating the slope, or ringing, of the 
selective filter. This is done as follows. The 
multivibrator circuit is designed so that V2B 
is normally in a saturated condition. Under 
these crcumstances V2A, which is cut off, or 
nearly so, has the full plate voltage at its 
plate. This voltage when applied to the grid 
of V2B through RIO, consequently holds this 
grid at a slightly positive (or zero) voltage. 
This, as mentioned, causes plate current to 
flow through V2B and causes a large voltage 
drop through R12. This lower voltage fed 
through R9 to the grid of V2A fails to over- 
come the negative bias voltage on this grid and 
leaves it at a negative potential , or the tube 
in a cut off (or nearly so) condition. This mul- 
tivibrator h known as a flip-flop circuit which 
means that it can rest in either the condition 
described or in the reverse condition, in which 
V2A is heavily conducting and V2B is cut off- 
However, in this application the circuit is un- 
balanced which means that, while at rest, V2A 
will always be in the cutoff condition and V2B 
will always be in the heavy current carrying 
state. Now when a signal passes through the 



, a_fcr^. .'. .■ \-. t : 



■■■■li '^TT: .■:-:'.-:.-*.t-. .■.4-: il'...- 




30 



73 MAGAZINE 









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fijter and is rectified into a ppsitive pulse by 
the diodes and applied to the grid of V2A it 
overcomes the negative bias and starts a eur- 
reftt flow through the tube. This in turn in- 
creases the voltage drop through R8, decreas- 
ing the voltage at V2A plate which, in turn, 
decreases the positive grid voltage on V2B al- 
lowing the bias to take over on that tube, thus 
decreasing the plate current flow through its 
plate load resistor R12, This, of course, in- 
creases the voltage on the plate and^ feeding 
this increased positive voltage through R9 to 
the grid of V2A enforces the original positive 
signal pulse and flips the circuit over to the 
opposite condition it assumed while at rest. 
Now when the signal is removed by the end 
of the dot being sent, the voltage on the grid 
of V2A goes down and starts the entire se- 
quence in reverse. Forcing the circuit to flop 
back to its original condition. This is why this 
circuit is known as a flip-flop circuit, with 
its characteristic ability to change rapidly (a 
few microseconds) from one condition to the 
other. 

Just how does this apply to this device? 
Let*s look at Fig, 2 again. Let's say, for ex- 
ample, that the signal is plus 2 volts in value 
with the trigger level set at plus 1 volt (line 
"X" on;2A or at points ''C* and *'D'* on 20). 
LfOoking at 2C again, as the signal voltage 
builds up, from zero to one volt (point **C^0 
the multivibrator remains in the original no 
signal condition, however upon passing the 

DECEMBER 1962 



one volt lever V2A starts to conduct and due 
to the action of the multivibrator instantly 
flips over to full reverse condition from the 
original state. At the end of the dot the vol- 
tage at the grid of V2A starts to fall as shown 
on 2C and as it passes point "D" the plate 
current of V2A starts to fall thereby revers- 
ing the seqLience of events with V2B and 
flopping the circuit instantly back to the origi- 
nal condition. 

Now why do we do this? We have taken 
a square burst of signal, representing a dot 
for example, and in passing it through a high 
Q selective circuit have destroyed its original 
shape and then we have reshaped it back to 
its original shape by the action of the multi- 
vibrator. This will allow us to use this re- 
claimed signal to trigger an oscillator on and 
off to give us a clean, positive keyed output 
signal thus overcoming one of the prime ob- 
jections to the original circuit of a few years 
back. 

The oscillator is a typical neon bulb relaxa- 
tion oscillator comprising of R13, R23, R14, 
C7 and the neon bulb NEl. This circuit^roiild 
be normally oscillating except for the action 
of the keyer tube V3A* This tube has its grid 
in parallel with the grid of V2B so that in 
a normal no signal input condition the same 
plus voltage is applied to its grid as is applied 
to the grid of V2B, This saturates the tube 
which causes such a large voltage drop 
through R13 and R22 that the neon bulb fails; 






t:4 



to oscillate. When the signal is applied to the 
unit the multivibrator tube V2 flips over, 
which cuts off the plate current of V2B and 
V3A* This cut off condition of V3A removes 
the tube load through R13 and R22 thereby 
raising the voltage on the neon bulb thus al- 
lowing- it to start oscillating- Wlien the signal 
ends, the multivibrator flops back and stops 
the neon bulb from oscillating — this explains 
the "why" of the multivibrator. 

The output of the neon bulb is then taken 
off R14 and fed into V4B where it is ampli- 
fied and delivered to the output phones, or 
possibly a small speaker, A speaker will prob- 
ably need another stage of amplification how- 
ever. 

The second channel comprising of V3B and 
V4A is a straight amplifier which takes the 
normal output of the receiver, before it passes 
into the filter eircuitj and after passing 
through V3B is fed into V4A- It is there am- 
plified and mixed with the output of V4B by 
the common plate load resistor R17. Either 
signal can then be heard, or both can be heard 
at once, depending upon the setting of the in- 
dividual volume controls R14 and R18* For 
normal use R18 is set for comfortable output 
level and with R14 set at zero, a signal is 



tuned in, in the normal manner. If interfer- 
ence conditions require it then R14 can be in- 
creased and the receiver tuned (or the BFO 
adjusted) until the beat note is of the proper 
frequency to pass through the filter network. 
The neon tube will then be triggered and can 
be heard in the output by advancing R14- 
The original signal with its interference, com- 
ing in on the other channel through R18, can 
be eliminated by turning down that volume 
control until it no longer bothers — to zero if 
you desire- The interfering signal must be 
outside of the passband of the filter of course 
but since this band is only 90 cycles wide at 
the 3db points, and can be made much less 
than that by lowering the resonant frequency 
of the filter, this usually can be accomplished. 
The power supply is normal with nothing 
critical. The only thing about it, which might 
be termed unusual is R21j which sets the nega- 
tive bias on V2. The value of this potentio- 
meter might have to be changed if a low^er 
plate voltage is used. If so a 2K potentiometer 
should be OK. The important thing is to have 
the grid voltages on V2 as described. R23 can 
be adjusted to set the plate voltage to 220 
vdc if it is normally higher, or can be omit- 
ted if the output voltage is below 220, 




32 



73 MAGAZINE 




DRAKE 



MODEL 







AMATEUR NET 



^^Wi 



„__ — ■ ' MODEL- ZB 




^-v ■■■--ti 



It has been gratifying to read comments 
of 2-B users on their warranty cards* 
Here are a few . . • 



«—«■ ^r^'oui*/ ^r '■" 



* ' ^ ? » tT-'^* 



'■*;" 



,i^: 






^\kV*' 



"The 2-B is not a receiver, it's HUMAN, Cuts up 
those novice bands like hamburgers/' 

KIMJS, Lexington, Mass. 

^fi ^ ^ 

''Have owned and operated many receivers in 

40 years of hamming but the 2-B is the best. It 

has everything/' W2JJr New York City 

t^^f- B^^. ^J^ 

''Excellent! Reatty amazed at its performance. 
Stable as a boulder, even with 'fist test/ Would 
be worth it at twice the price/' 

K6HIU, San Drego, Calif, 

• jMf ^U ^^ 

■'I* T* *|5 

''Wonderful! Can't see how such a small box 

runs rings around my big " (5 months later) 

"After 2000 DX contacts I can't see how it per- 
forms so well at such a price and small size/' 

W9GFF, Chicago, III, 

4^ ^ # 

"Am studying for novice and find the 2-B an 
excellent receiver to pick out stations for code 
practice/' Alex H- Tinker^ Jr., Scottsdale, Ariz* 

3|E J|C ^ 

"Very stable, real good AM receiver/' 

KSGYU, Kilgore, Texas 

^ 3fe 9|c 

"After searching for a year have concluded the 
2-B comes closest to perfection. Everything in it 
is aimed at communication effectiveness/' 

HPIFQ, Panama 



"I've had them all and this receiver tops them 
all/' KGDI, Santa Barbara, Calif. 

^b bI* mM* 

"9^^ ^^^ ^T^ 

"Particularly like the variable passband/' 

W6KHH, Novato, Calif, 
* * * 

"Excellent on SSB and CW, Have compared with 
receivers costing up to 3 times as much and 
sensitivity and selectivity of 2-B is as good or 
better/' WA2P0H, Rome, N. Y, 

iflpi ^P -^Wf 

"One of the most surprising purchases 1 have 
ever made. Performance is superb in every way- 
First receiver ever owned that exceeds advertised 
claims/' W5NKE, Jacksonville, Ark, 

i^^w ■^P' ^^r* 

"In 20 years of hamming have never been more 
pleased. Operate 40 CW and the 2-6 has the 
selectivity to make DX chasing again worth 
while/' W6WAW, Los Angeles, Calif. 

^ m ^ 

"Didn't know so much receiver could be built so 
compact and neat Best I've seen for SSB- It's 
a pleasure to get on the air now/' 

W5WJQ, Thibodaux, La. 

a|E #; # 

"The 2*B is my fifth receiver, but the best I've 
hdd." LXIDE^ Luxembourg 



For more information ask your distributor or write us. Coming soon TR-3 All-Band Transceiver 

Box [8 7- A 
Miamisburg, Ohio 



R. L. DRAK 




CO 




PANY 



DECEMBER f962 



33 



Perhaps we should go through a brief "set- 
up" procedure for the unit, By steps it is as 
follows — 

1. Remove VI, V2, V3 and turn on the 

power supply, 

2. Adjust R23 (if used) to give approxi- 
mately 220 vdc to the unit. 

3. Plug in a pair of fones and you should 
hear the neon bulb oscillating. Adjust 
R13 for the tone desired and R14 for the 
correct volume. 

4. Insert V3 and allow warm up time. The 
tone should stop. 

5. Plug the unit into receiver, or into an 
audio oscillator, and adjust R18 for 
proper volume of signal heard in the 
output, 

6* Insert V2 and allow warm up time. No 
change should occur, 

7. Insert VI and allow warm up time* With 
no signal into the unit from the receiver, 
or oscillator J no change should be de- 
tected. With a signal in, if it is of the 
proper audio pitch, it should key the 
neon bulb, which can be heard in the 
output. Adjust the receiver gain until the 
noise does not trigger the unit. 

8i Now tune in a signal in the normal man- 
ner and, as the tone goes through the 
passband of the filter the neon should 
plop into oscillation in step with the sig- 
nal and you can hear either one individu- 
ally or both at once as you desire. If 
yoo use a filter frequency of 500 cycles 
or lower this neon signal will plop in 
and plop out as you tune the receiver 
leaving interference noise, etc., noticeably 
absent* 

In case, after step 4, the neon tube does 
not stop oscillating, check the voltage at the 
grid of V3A. This should read zero or slight- 
ly positive. If it is not — and after the wiring 
has been checked for a mistake — check the vol- 
tage on the grid of V2A — ^this voltage should be 
approximately one volt negative. In case these 
readings are reversed with V2A positive and 
V3A negative and the wiring checks out OK, 
the value of Rll will have to be changed. In 
fact it might be advisable to put Rll in as a 
pot, of 20 K value and mount it on the back 
of the chassis^ — especially if you deviate from 
the 220 volts dc used on this unit. The plate 
voltage is not at all critical, in fact and any- 
thing from 100 to 250 volts can be used — If 
you adjust Rll and R21 for whatever you*re 
using. Going back, if the grid of V3A is not 
zero or slightly positive with no signal input 
it must be made so by the adjustment of RH, 
Then with a signal going through the filter, 
the grids of V2 will flop back and forth from 
2ero to minus. The readings should be, for 
V2A, from approximately minus one volt to 
a plus half volt or so and for V2B (and V3A) 
from approximately 3sero to three volts nega- 



tive or so. These are the only critical features 
of the unit, and these are not especially so. 

You have noticed from the photo that this 
unit is constructed on a printed circuit board. 
This is for no special reason except that I 
recognize this to be a good method of con- 
struction and enjoy laying out the boards. It 
was done in my home workshop using a small 
artist brush and ordinary enamel for the re- 
sist (the name for the material which covers 
the copper that is to be left after etching). 
The etchant acid was placed in a glass dish 
and warmed slightly before the board was 
immersed. This warming is not necessary, but 
it speeds up the process, A very mild warm- 
ing is sufficient, in any event, and for best 
results keep stirring the acid with a wooden 
paddle while the etchant is working. Laying 
out the circuit board is not complicated, but 
is tricky and probably could be the subject 
for an article in itself. If it is desired to copy 
the board used here, Pig, 4 is an exact layout 
drawn to scale. 

This completes the description of the unit- 
It will be found to be a very real assist in 
copying signals through QRN and QRM. One 
of the requirements is, of course, that the de- 
sired signal be not too far down in the mud. 
If the noise triggers the neon while you are 
trjdng to dig out the signal the device is of 
limited use. However, the action of C6 does a 
good job of eliminating noise peaks, so many 
times it would appear that you are, in fact, 
below the noise level while the unit is operat- 
ing satisfactorily. Generally speaking this 
unit will be of the most value to the Novice 
or "rag chewer.'* It would seem that by the 
condition of the bands these days only Heaven 
can help the DX hound. 

One more comment on the circuit — one re- 
sistor that shows on the schematic is R6, This 
potentiometer was used to set the threshold 
level for the neon oscillator keying and theo- 
retically was a useful adjunct to the unit, 
however, in actual practice it was found to 
be excess baggage and it is recommended that 
it be omitted. The threshold is set close enough 
by R5 and the volume control of your receiver 
can be used to meet the level requirements 
very easily. 

The unit as described, is, in fact, a protot) pe 
and any builder can probably improve upon 
it with a little thought. But in any event if 
you think you need some more selectivity for 
your code contacts — and who doesn't — get the 
old head gears turning, the soldering iron out 
and erive it a go, , . . W6EUM 



CLUB RATE 

Subscripfions will be accepted at the 
Club Rate of $3>00 each when sent in 
groups of five or more. This holds for 
either new or renewal subscriptions. 
Please list names, calls, and QTH's. 



I 



34 



73 MAGAZINE 



Using the 
Rate-of-Change 
Noise Limiter 



Larry Levy WA21NM 



THE rate of change limiter is one of the 
first big advances in noise hmiter design 
that we have had in quite a N\'hile. I won't go 
into a description of all the advantages of 
the limiter as Jim Kyle K5JKX, has done an 
excellent job of that already. (See 73 maga- 
zine, Apr., 1961, P. 16.) After looking at 
table 1 of Jim's article, X decided to see if 
those seemingly impossible figures were true. 
To do this, I installed a rate of change Hmiter 
in my 2 meter mobile transceiver. 

The original circuit had a few faults, but 
these were mainly in connecting the limiter to 
a receiver. One problem was that there was 
no place to connect the AVC line, and another 
was that there was no way to disable the 
limiter, if only for comparison purposes. 

The necessary modificatioiis are shown as 
bold Hnes in the schematic. AVC voltage 
equals that from a standard diode detector. 
The diodes used were a pair of 1 N295s but a 
12AL5 would probably work better, 

I noticed that the addition of the limiter 
lowered the audio slightly so if your rig does 
not have spare audio gain, it may be neces- 
sary to add another stage of audio. A nuvistor 
will work fine and takes up very Uttle space. 
Details are shown in Fig. 2. Since my trans- 



si- anl 







FIQ. 1 



»Z50 



TO VOC , 

CONTROL 




OUTPUT 



ita^iM^ 



WHAT IS IT? 



mifrnt. H^!^3t ^mmitt 



mtmim 



»i»«ti^ 



'#iiigLfT)Vfeii;triai4f9 



4iJl»' ftlfM ' 



iKmm ^^ 



Pi n ir-r<* 



HP» •TjT 



[\ if the V/aUrs Universal Hybrid Coupler, one of 
the handiest gadgets youVe e^^r seen for the 

hamshack. 




It IS a Phone Patch, connecting your receiver and 
transmitter to the phone lines. 




Hybrid: Works on SSB (VOX) and AM • 
even CW! 



- or 




FIG 2 



Tape record your CQ's — DX contacts — messages — 
etc. Tape record and play back on the phone too- 

See Year Disfrlbufor . * • 

UNH ERSAL HYBRID 
COUPLER 

only $49.50 
See page 54 ia Sepf. '62 73. 

WATERS MFG. 

WAYLAND. MASSACHUSETTS 



DECEMBER 1962 



Buy from 73 adverfisers 



35 



r 



ceiver uses a series- pur allel heater string, it 
was necessary to change the 6U8 to a 12AX7 
and connect the nuvistor in parallel with the 
12AX7- Another solution would be to add a 
second nuvistor as an rf amplifien 

The results are amazing, as iJie limiter 



completely eliminated all ignition noise from 
my XK-140, wlxlcli was so noisy that I gave up 
trying to operate 2 meter mobile from it. With 
very Httlu uifort, it should be possible to add 
this hniiter to any receiver, and eliminate al- 
most all qrn. . . . WA2INM 




Roy Pafenberq W4WKM 
John Bowden W4SYJ 



73 Tests the 

Heath 




-20 Mobile Receiver 



^ANOTHER MOBILE RECEIVER? 
Well, not exactly. While Heath calls their new 
HR-20 kit a mobile receiver, an SSB receiver 
andy at tknes, a mobile SSB receiver, it is 
more than this, Tlie HR-20 is an advanced 
design amateur band receiver, less power sup- 
ply, which provides, in a compact package, 
those receiver characteristics and features 
wliicli Ilealli Ixelieved would provide the most 
performance for the money. As far as the 
writers are concerned. Heath has a whinner. 

The HR-20 Receiver is a 7 tube (plus gas 
regulator^ Zener diode and transistor reg- 
ulator) single conversion superheterodyne re- 
ceiver designed for CW, SSB and AM recep- 
tion in the 80 through 10 meter amateur 
bands. Modem design techniques and com- 
ponents insure excellent performance in all 
modes. Before we go into the circuit details, 
a few comments regardmg the design phi- 
losophy and histor)^ of the HR'20 Receiver are 
in or den 

As shown in the photograph, the physical 
configuration of the HR-20 is similar to that 



of the previous Heath mobile receiver, the 
MR-1 Commanche, Much of the circuitry, the 
panel layout and physical dimensions of the 
original model have been retained. The major 
changes are in new features for improved SSB 
reception. Included in these are replacement 
of the original variable frequency BFO with 
a dual frequency, cxystal controlled oscillator 
for selectable sideband operation, selectable 
AGC time constant and a transistorized high 
frequency oscillator filament voltage regulator 
for 12 volt dc mobile operation, 

The initial design concept for the HR-20 
was as mobile receiver to be used in confune- 
tion with the Heath HX-20 Mobile SSB Trans- 
mitter. When used in this application, both 
units may be mounted on an accessory base 
which is available as the AK-6 Mobile Base 
Mount. Such an installation is shown in the 
second photograph. An external, 8 ohm 
speaker is required and the AK-7 ^fobile 
Speaker is available for this purpose. Heath 
also markets the HPIO, 12 volt dc power 
supply for mobile use. Tliis transistorized^ 120 



36 



73 MAGAZfNE 



The GOLDEN GUARDIAN (48bi) 




for discriminating ann 
who are satisfied 

ing less than 



NGLE SIDE 




FILTERS 



rtc I 




TECHNICAL DATA 

Impedance: 640 Ohms in and 
out (unbalanced to ground) 

Unwanted Side Band Rejection: 
Greater than 55db 

Passband Ripple: ± -5db 

Shape factor: 6 to 20db 
1-15 to 1 

Shape factor: 6 to 50db 
1,44 to 1 

Package Size: 2%" x 1%" x 1" 

Price: $42,95 Each 



- "GOdti 




T 



r — r 







+ M * 



lit I r t?- ■ atflU ■C'HV 



The SILVER SENTINEL (32bi) 




t-flfce -^1 



' -€(MS 



*-50d» 



-^40i* 



-■Mdb 



"i&Oi 



—i 1 ] ft~ 1 T" 

as^ a^e b«9 so sixm 9^002 900^ 



TECHNICAL DATA 

Impedance: 560 Ohms m 
and out 

Unwanted Side Band Rejec- 
tion: Greater than 40db 

Passband Ripple: ± *5db 

Shape factor: 6 to 20db 
1,21 to 1 

Shape facton 6 to 50db 
1.56 to 1 

Package Size: }H"xV4''xl 

Price: $32.95 Each 



ff 



Both the Gofcfen Guardian and the Sif- 
ver Sentinel contain a precision McCoy 
fitter and two of the famous M^ McCoy 

Oscillator crystals. By switching crys* 



tals either upper or lower side band 
operation may be selected. Balanced 
nnodulator circuit wtU be supplied upon 
request. 



Both sets are available through 
teadiri£ distrffeytors- To oMain 
the name of the distribijtor 
nearest you or for additional 
speciftc information, write: 



ELECTRONICS CO. 

Oept. 73-12 

MT. HOLLY SPRfNGS. PA. 
Phone: HUnter G-3411 



SUBSIDIARY OF OAK MANUF * "'"irRfNG CO 



DECEMBER 1962 



37 



w 



iHTI 



k»1 PL t AHF 



vi 



UUMI 



1 « C 
rtLTEP 



n 



T 



Hn 



tcr tr itMf 



I i 



Q> 






k't 




k/j U.1 






BLOCH DiACAAW 



watt unit supplies power for both the HR-20 
Receiver and the HX-20 Transmitter in the 
normal mobile installation- 

Both the HR-20 Receiver and the HX-20 
Transmitter are well suited for home station 
use and, in this application, Heath recom- 
nunds their HW-20 Utility ac Power Supply. 
Although the HR-20 is designed for easy in- 
tegration into the home station or mobile in- 
stallation, it may of course be used as a 
straight, ham band receiver. In this case^ all 
that is re(jiiired is an antenna, speaker and 
a power supply considerably less elaborate 
than those mentioned above. Power supply re- 
quiremeiits for the receiver alone are shown 
in the specification chart. 

The HR-20 circuit diagiam is a bit large 
to include in a review article, however the 
block diagram shown in Fig. 1 will aid in 
understanding the following discussion. The 
receiver is a single conversion superhet using 
a 3.0 mc if with a crystal lattice filter, A 
6BZ6 if stage feeds a 6EA8 mixer-oscillator 
stage which in turn feeds the crystal lattice if 
filter. Use of the relatively high, 3.0 mc if 
£requenc\ , along with the sclecti\dty provided 
by the high Q rf and mixer grid circuits, gives 
good image rejection. The cr>'stal lattice filter 
provides the if bandpass diaraeteristics re- 
quired for effective SSB reception. The HFO 
tuned circuits are individually temperature 
compensated to insure low drift. This coupled 
with rugged construction and the use of a 
transmitting type variable capacitor pro\ides 
a high order of stability for the HFO. This 
capacitor is a two section unit which also tunes 
the mixer mid circuit. The rf input circuit 
is resonated by a single section capacitor 
designated "ANTENNA TUXIXG," While 
slightly unconventional, this arrangement al- 
lows use of the compact tiansmitting type 
capacitor for the osciUator-mixer tuned cir- 
cuits and permits better physical layout of the 
stages. 



The selectivity characteristics of the crystal 
filter, listed in the specifications, provide a very 
good compromise bet\veen the requirements 
for AM and SSB reception. Selectivity is suf- 
ficcntly sliarp for effective SSB reception while 
an AM signal may be centered in the pass- 
band witliout loss of intelligibility. Two stages 
of *'/ amplification, using a 6BZ6 and the pent- 
ode section of a 6EA8, follow the crystal fil- 
ter and i:)r oxide most of the receiver gain* 
The second if ampliiier feeds either a conven- 
tional diode detector for normal phone opera- 
tion or a product detector for CW, SSB and 
exalted carrier AM reception, 

A conventional diode gate noise limiter, 
wliich is disabled when the product detector 
IS used, is provided for AM reception. A 
separate diode AGC detector is used for gain 
control and to drive the triode section of a 
6EA8 tube which is used as an S-Meter 
amplifier. The AGC circuit used in the HR-20 
provides AGC operation for both AM and 
SSB reception. A front panel switch provides 




38 



73 MAGAZINE 



24 HOUR CLOCK 

Chrome-plated 8'' metaf wall clock. Inner dial with south 

polar projection map of world indicates time around 

world. Polar projection dial adjustable for various time 

zones. Shipping weight 2 lbs. 

110 V, 60 cy, $8,47 

12'', 24 hr. crocki 110 V« 60 cy. without world map. $13.95 

(Prices include taxi 





CLEGG 99'er 6 METER TRANSCEIVER 

A true ham sta- 
tion, ideal for 
both fixed sta- 
tion and mobile 
operation, Dou- 
ble conversion 
superhet gives 
yoii extreme se- 
lectivityand free- 
dom from images 
and cross modu- 
lation. Transmitter section has an uitra^stable 
crystal oscillator which also may be contrafled by 
external VFO, Efficient, fully modulated 8 watt final 
works into flexible Pi network tank circuit. Large 
S meter serves for transmitter tune-up procedure. 

Amateur net price $159.95. 

ZEUS and INTERCEPTOR also in stock. 




SUPEREX HAM HEADPHONES 

Full comfort even after many en- 
joyable hours of continuous use. 
Superb comfort even for eyeglass 
wearers. Crisp, distortionless reoro^ 
duction and high sensitivity allows 
you to single out that weak signal 
and hard to reach station, 600 
ohms impedance, completely adjust- 
able head harness. $24.95 



AMECO CB-6 CONVERTERS 

Tube-type low-noise, high-gain 
converters, IF easily changed. 
Specify IF. 

CB en — 6 meter kit, 6ES8-rf 
Amp., 6U8-mix,/osc. $13.95 

CB^BW — 6 meter wired and 
tested. $27.50 

CB-2K — 2 meter kit, 6ES8 
1st rf amp., 5U8'2nd rf amp/ 
mix, 6J6 osc. $23.95 

CB 2W — 2 meters wired and 
tested, $33.95 




^ 





Model PS-1— Matching Powe 
Supply — plugs directly inti 
CB-6, CB-2 and all CN units, 
PS-IK — Kit — $10.50 

PS-IW — Wired — $11,50 



Shown approx. 
actual size. 



PRECISION PLANETARY-VERNIER 
for exceptionally fine tuning 

Superb craftsmanship by Jackson Bros, of England. 
Ball bearing drive, Va" dia. Shaft IVs" long, 6:1 ratio. 
Vy FB for fine tuning. Easily adaptabie to any shaft. 

Comnarabie value $5.95. Amateur net $1.50 63. 
10 for $13.50 



for ham^ 



SEND FOR 
FREE CATALOG 



Tradeins 

welcomed. 



PRECISION BALL DRtVE DIAL 

Another superb product of 
Jackson Bros, of England. 4" 
dia, dial with 6:1 ball drive 
ratio. Fits standard Va" shaft. 
For that velvet touch.*. 

Amateur net $3.95 



VERSATILE MINIATURE TRANSFORMER 

Same as used in W2EWL SSB Rig- March, 1956 
QST. Three sets of CT windings for a com- 
bination of impedancesi 600 ohms, 
5200 ohms. 22000 ohms. (By using 
center taps the impedances are quar- 
tered). The ideal transformer for a 
SSB transmitter. Other uses: inter* 
stage, transistor, high imped- 
ance choke, line to grid or 
plate, etc. Size only 2 
%" w. X W d. New 
fully shielded. 

Amateur net $1.39. 
3 for $349* 
TO for $10.75 





\*f 



h. X 

and 



MAIL ORDERS 
PROMPTLY PROCESSED. 

SAME-DAY 
SHIPMENT FROM STOCK. 



TO SAVE C,0,D. CHftRSES. PLEASE INCLUDI 

SUFFICIENT POSTAGE WITH YOUR Or^DiH. 

ANY EXTRA ""JNEf WILL BE RETURNED. 



ELECTRONICS, INC 



ALL P:T:CES F.O.S. N.Y.C. 
Arrow's Export Dept. JHips To All ^ arts Of The World! 
Prices Subj et To f^hi.ige Without Notice 



65 Cortlandt St., N.Y. 7, N.Y. • 525 Jericho Tpke., Mineola. N.Y. • 225 Main St, Korwalk, Conn. 

212 - Dlgby 9-4730 516 - Pioneer 8-8686 203 - Victor 7-5889 



I 



a* (f AMP 



J J 



i^ ''« ©i^-^::^ 




1*'^ AMOlO 
AMP 




tj'—^ ^*Q^ 



i«n>fr*^ 



V6 



PRODUCT 






DCTEC^OR -^ 



short or long time constant or disables the 
AGC as desired. 

The product detector utilizes a 6BE6 penta- 
grid converter as the mixer and cr>stal eon- 
trolled oscillator. This circuit provides very 
good performance with a minimum of com- 
ponents and should be of interest to amateurs 
seeking improved SSB reception with their 
conventional home brew or commercial re- 
ceivers. Fig, 2 shows the schematic diagram 
of this circuit. Crystals CA, 2998,5 kc% and 
CB, 3()()L5 kc, are positioned T5 kc below 
and above the 3,0 me center frequency of the 
crystal filter. Therefore, selectable sideband 
reception is possilile l>y positioning the oscil- 
lator on the upper or lower slope of the crys- 
tal filter selectivity curve. It should be noted 
that the "SIDEBAND SELECTOR" switch 
only selects the appropriate product detector 
crystal It is still necessary to time the main 
tuning dial to zero beat the crystal oscillator 
with the actual or suppressed carrier of the 
if translated, desired signal 

An OA2 gas rt^^ujator tube supplies a con- 
stant 150 volts to the plates of the two oscil- 
lators and to the screens of the rf amplifier, 
1st mixer and the if amplifiers. The balance 
of tlie receiver circuitry is more or less con- 
ventional with the ex or jit ion of the transistor- 
ized filament voltage regulator. This circuit, 
shown in Fig. 3, supplies a constant voltage to 
the heater of the 1st mixer-oscillator and rf 
amplifier tubes. This feature, used only in the 
12 volt dc power supply wiring option, stabil- 
izes the oscillator fihunent voltage and there- 
fore contrihutes to the excellent frequency 
stabiht> of the high frequency oscillator over 
the wide range of primary* voltage encountered 
in mobile service. Regulation of the rf stage is 
incidental to a simi^le 6 or 12 volt wiring 
option. 

This circuit should be of value to those who 
have been fighting the complex problem of 
mobile VFO stability^. Tlie parallel connected 
heaters of VI and V2 are wired in series \\ ith 
the emitter follower transistor chcuit. The 
base input voltage of the transistor is the 



breakdown voltage of the Zener diode which 
is relatively constant for a wide range of 
supply voltage. Resistor R46 provides the 
base drive current for the transistor and break- 
down current for the Zener diode. Since the 
t>ase to emitter resistance is quite low^ the 
emitter potential is held to a value slightly 
lower thaji the base. The overall eff-ect is that 
the unwanted voltage variations appear be- 
tween the emitter and collector of the tran- 
sistor while the voltage applied to the tube 
heaters is regulated. 

One of the first kits off the production line 
was shipped for this test, Tlie kit was well 
packed and^ on unpacking, no damage of any 
kind was noted, AH components were ex- 
amined and found to be of excellent quality. 
Dipped mica and disc ceramic capacitors are 
used extensively. The only paper capacitor in 
the receiver is a high quality molded plastic 
cased unit. Insulation on all rotary switches 
is apparently one of the new plastic laminated 
fiberglas materials. Mechanical parts are higli 
quality. Dial drive gears are spring loaded 
where required and nylon, brass and steel 
gears are used. All exposed steel surfaces are 
heavily plated* 

Mecliiinically, the reeeiver is quite com- 
plex, consisting of a main chassis assembly 
secured to a heavy, die Last front panel. Sub- 
panels are used to mount the various con- 
trols, gear drive for the dial and some other 
components. Extensive shielding is used. 
The result, when everything is bolted to- 
gellun', is an extremely rugged assembly tliut 
contributes greatly to the stability of the re- 
ceiver. However, construction is not unduly 
complicated. The main chassis consists of a 
Hat plate on vvliiuh most components are 
mounted and most of the wiring completed 
prior to mechanical assembly of the chassis 
parts is accomplished. As Heath points out 
in the form letter packed with the kit, ^TThis 
receiver is one of the more complex and 
compact products marketed in kit form by 



1337 
FILAMENT 
VOLTAGE 
REGULATOR 



DtOOE 




nL+ 



40 



73 MAGAZINE 



the Heath Company." Asseiiibly, wiring and 
testing is not diffieult but plenty of time and 
carrfiil attention to detail are required. 

The instruction manual supplied with the 
HR-20 was evaluated as the kit was con- 
structed. This manual is quite comprehensive, 
consisting of 64, 8^2'' x 11" pages. The manual 
contains some 50 drawings showing the as- 
sembly, wiring and installation of the re- 
ceiver. Many of the more complex assembly 
drawings are printed on large, fold-out sheets. 
In addition, a separate "giant size" schematic 
diagram is supplied for wall mounting. Con- 
struction , testing and installation are covered 
by nearly 500 "check off" steps. These instruc- 
tions are arranged so as to be self checking 
and it would indeed be difficult to goof any 
part of the construction. 

Three minor errors, possibly typographical, 
were found in the instructions. Since the er- 
rors are obvious and Heath is correcting them 
with an errata sheet, they will not be listed 
here. The pictorials were remarkably good 
and the only error noted was omission of a 
small nylon w'asher in the gear drive assembly. 
All parts are shown in drawings in the front 
of the manual so that even the relativelv 
inexperienced amateur should have little dif- 
ficulty in identifying tlie components. Sepa- 
rate sections of the manual are devoted to 
installation and noise suppression. All in all, 
the manual is extremely good. 

Assembly, with minor exceptions, pro- 
ceeded according to the instructions. The 
hermetic seal bushings on the bottom of the 
crystal filter would not quite pass through 
the chassis clearance holes. A pass with a file 
took care of this problem. The same was 
true of the crystal socket mounting holes- 
Wiring was easily accomplished. The flat, 
open main cliassis plate makes it a snap to 
achieve professional results. Despite tlie ap- 
parent complexity of the dial drive assem- 
bly, it goes together qmte easily. One "E" 
retaining washer required bending to make 
a snug fit in the shaft groove. Only one ease 
of crowded assemblv was noted. The audio 
output stage screen filter capacitor, a 20 mfd 
350 volt unit, barely fits as shown in the in- 
structions. This is probably accounted for by 
the increase in value (and physical size) over 
the 8 mfd capacitor shown in the pre-produc- 
tion schematic diagram. 

The completed receiver was carefully 
checked before power was applied. Every- 
thing clu eked out so power was applied, with 
no smoke resulting. Alignment was started 
but stopped when high pitched, audio feed- 
back was noted at certain settings of the audio | 



I 








TR 

sviriTc 



(TBAKSMfT RECEIVE SWITCH) 

MODEL 381 



kn electronic antenna changeover switch. Transmitter is 
continuous!/ connected lo antenna, antenna circuit lo re- 
ceiver is blocked during transmit. Ho switch contacts to 
arc or burn. Switching is instantaneoys. Setectable 
band^switching insures no loss in receiver sensitivity. 
Substantial gain ifi receiver sensitivity results in mosf 
installatifiiis. Ideal for hreak-in operation on CW, SSB 
and AM* Bandswikh conveniently located on front. Three 
coai connectors are moynted on rear, Conservalivefy de- 
signed for fiifl leQal power. Operates from 115 volts^ 
60 cycles- For 52-75 ohm tines. 

Size 4%" X r t SUj" 
BARKCR & WHJJAMSON, Ine, 

^adio Connutiniendcti pfjufpinfitf fiincc f932 

BRISTOL., F£NNSYJLVANIA • STillwell SBBBl 






DOW-KEY DK60 SERIES 



DK60-C2C 




Small, Compact, 

Light Weight, 
Less than 9 oz- 



4 VERSATILE 

MODELS 
A.C. or D.C. 

COAXIAL 
RELAYS 



Also Available 

with Type C* 

TNC. BNC. N & 

UHF Connecton 



Outstanding favorite for amateurs . 
hi nations for industrials! Low VSWR 
from to 500 mc. LOW LOSSES 



, Versatile com- 
less than 1,15:1 
High Contact 



Pressures, LOW CROSS-TALK through use of patented 
"isolated connector" arrangement HIGH POWER RAT- 
ING, All coils encapsulcd in epoxy resin for quieter 
operation and resistance to moisture. 



^ UNCONDITIONAL 
GUARANTEE for 
one year, (We 
win repair If 
faulty within 1 
year.) 

i^. See one of our 
100 dealers and 
distributors In U. 
8» mnct Canada for 
catalog sheets or 
write: 



ik All Relays In weatherproof 
boxes for exterior Installation. 

ik Ganged, xnuUlpie position 
iiwitch arrangement available 
for remote control selection 
of antennas. 

STANDARD RELAYS: DK60, DKeO^G, 
DK60-2C and DK60-G2G ^^ 



PRICED rROM 



..$12.45 



DOW-KEY COMPANY 

Tliief River Fall^, Minnesota 



DECEMBER 1962 



4t 



gain control. Wiring, lead dress and conv 
ponents were checked with no luck* Finally, 
the .001 mfd capacitor across the primary 
of the audio output transformer was replaced 
with a ,002 mfd unit* This proved to be a 
permanent fix. The oscillation was probably 
caused by an unusual combination of extreme 
tolerance components. However, to avoid the 
possibihty of this occurring in otiier receivers, 
we recommended to Ikalh that this change 
be incorporated in all kits. The balance of 
the alignment went smoothly with no com- 
plications of any kind. Heath proved correct 
in their estimate of the time required to com- 
plete the kit, roughly 30 hours from start to 



Then came the pay-off—the "on tlie air" 
tests. Be advised that the performance of the 
receiver is all that the specifications say it is. 
Sensitivity is extremely good, with receiver 
noise way down. The selectivity, as previously 
mentioned, is a very fine compromise between 
the requirements for SSB and AM reception. 
CW is of course another story; a vaUd com- 
parison is the CW performance of the Collins 
75S-1 with SSB filters. Interference on one 
side of the desired signal may be "dropped 
over the edge** of the crystal filter bandpass 
but you have to live \vith what is left on the 
Qtlier side, Wliile audio gain is adequate, there 
is no great reserve. 

Tuning SSB signals is a pleasuie. The dial 
ratio is about the optimum compromise be- 
tween SSB tuning requirements and the need 
to scan each amateur band in one receiver 
tuning range. While a dual speed drive would 
probably be better, the resultant complexity 
might prove prohibitive for kit construction. 
Although the gears are spring loaded, a slight 
roughness was noted in the tuning drive* 
Based on experience with previous Heath 
gear drives^ this is expected to diminish with 
use- The AGC system used in the HR-20 is 
excellent, with very effective action being ob- 
tained on SSB signals. Use of selectable AGC 
time constants reaUy pays off in SSB recep- 
tion* 

Frequency stabiKty of the HR'20 is ex- 
tremely good. AFter all, the stability require- 
ments for mobile SSB reception are demand- 



ing to say the least. Total warm-up drift on 
20 meters was 3 kc from an absolutely cold 
start. After warm-up, the receiver is rock 
stable. The receiver was heterodyned with a 
10 meter signal; lifted a couple inches off the 
bench and dropped. The result was an in- 
stantaneous **gurgle'' but the beat note did 
not change. Try this test %\ith other receiv- 
ers; it is quite revealing. 

The frequency stability of the HR-20 is of 
great interest to the writers. It would ap- 
pear possible to convert the HR-20 Receiver 
to an SSB transceiver, using a small inboard 
or outboard adaptor imit. The performance 
of the receiver circuitry that would be used 
in such a conversion has proved more than 
adequate for the job. Therefore, plans are in 
the mill for this conversion. If it all pans out, 
this will be the subject of a future article. 

For a really rugged final test, the HR-20 
was compared side by side with a Collins 
75S-1. The 75S-1 uses a s>''stem of sideband 
selection where both the HFO and BFO 
frequencies are shifted with a single switch. 
This feature, coupled with the better dial 
ratio, made the 75S-1 easier and more con- 
venient to operate. However, for actual per- 
foimance, the Heath receiver did not suffer 
in comparison. Dollar for dollar, the HR-20 
will be extremely difficult to beat. In tlie 
opinion of the writers, the HR-20 is the best 
buy on the market today. 

. . , W4WKM and W4SYJ 

SPECIFICATIONS 

Freauency Coverage 

80 Meters — 3.^ to 4*0 mc 

40 Meters — 7.0 to 7,3 mc 

20 Meters — 14*0 to 14. 3S mc 

15 Meters — 21*0 to 21*5 mc 

10 Meters — 28,0 to 29.7 mc 
Intermediate Frequency 

3 mc 
IF Cnrsts! Filter 

Mid-frequency — 3*0 mc 

Bandwidth at — 6 db — 3,0 kc 

Bandwidth at — 60 db — lO.O ke maximum. 
Sensitivity 

1 microvolt or less, at 10 db sig-nal-to-noise ratio* 
Panel Controls 

SB1-SB2 

RF GAIN 

AF GAIN, power OFF 

CW/SSB-AM 

NOISE LI MITER OFF-ON 

AVC. OFF-FAST-SLOW 

Main Tuning 

BAND switch 

ANT TUNING 



5 KW PEP 
"8ALUN" 



Mep NEW/ 







WHITE fOR FREE'BALW* *SXIiPBO *S^«T*^rt 
BOOKLET Of PL'77 DESCSJe*^ ^ POfW^ AMTpWl^ 



A COMPLETE fyPNO- BAND KH -INCLUDES 1 KW 

5Cioeo"BAUurj " wire , insulato rs p p p 

AND COMPl^ETE fNSTRUCtiON S,^'^^'^ „ 
TO PROPERLY INSTALL ^ALUN 
S0or40or^or|5 ii096 

or n Of 10 Meter '1^— 

HIGH PERFORMANCE IMVERTED'V 
ANTENN A 

TEU«EX LABOftATORieS ASBURT PARK N.i 




42 



73 MAGAZINE 



Hear Panel Connectors 

Antenna (ANT) 50-75 ohms 

Power (PWRK 

Speaker (SPKRi 8 ohms 

Earphones (PHONES) 500 ohms 

FUSE 
Meter 

Front panel "S" meter itidicates received signal 
strength. 
Tube Complement 

6BZfr— RF amplifier- 

6EA8 — Mixer-oscillator. 

6BZ6 — First if amplifier, 

6EA8 — Second if amplifier and "S" meter amplifier, 

fiBK*?— Product detector— BFO. 

fiBJ7 — AM detector — AVC — noise limiter. 

6EBB — ^First audio — audio output* 

OA-2^ — Voltage regrulator. 
Power Requirefnents 

Filaments; 12 v at 2*5 amp ac or ^c. 

6 V at 5 amp ac or de^ 

B+ Voltaere: 275-350 v dc at 85-125 ma 

Total Power: 6S.5 watts. 
Cabinet Si?je 

6%" high X 12 1^'' wide x 9 IB/IG^' deep. 
Net Weight 

16 lbs, 
Shipoing Weight 

19 lbs. 
Cost 

$1S4.60- 
Assembly Time 

Approximately 30 Hours. 



Letters 



Dear Wayne & Virginia, 

Enjoy "73** and sorry yon eouli!n*t get to tbe Disney- 
land Convention* I suppose you're going to be so busy 
fixing up your new location that it will be some time 
before you get out this way again. Remember, Virginia 
wants to see Disneyland, Don't work her to death feed- 
ing and making beds for the freeloaders, I'm an old 
Yankee and who knows, I may drive up to your place 
sometime with my bedroll and a slab of bacon and give 
you a hand. Good luck with your new location and **73*\ 

Royal Bailey W6SEU 



Bdltofp 

Do you know of anybody using a Valiant on SSB with 
the SB- 10 adaptor? Vm. having a problem here after fol- 
lowing the QST article, page 48, August I960. I lost grid 
drive after installing switch SW4C. Perhaps some of 
your readers can help out* 

C. J. Williams WIROM 
47 Lake Avenue 
Old Orchard, Maine 
Perk&ps. 



Dear Wayne: 

Please print this in the '"My face is red" column. 
In refereiice to the Mobile Scope on page 36 of the 

August iBSue, I have received several comments such as, 
"It won't work/* In order to make it work change the 
intensity and focus controls to 500K and the resistor in 
series with the focus pot to 1.5 meg» The power supply 
works better if the 25 K bias resistor is changed to about 
fi20 ohms and R2 to 130 ohms at 1 watt. 

The external shell of the Itl3 is tied internaUy to pin 1 
so grounding the shell shorts the power supply. leaving 
it ungrounded presents a shock hasianL This probiem 
was solved here by coating the tube with several coats 
of Krylon and placing tape under the bracket. An alter- 
nate method would be to insert the 013 into a section 
of plastic tubing- K the scope is to be used in the shack 
use a separate filament transformer for the 913 and move 

the HV ground to pin 1 of the 913, 

Robert L. Williams K9DYS 



WVG 
MARK 



I 



f 1 




^^ 



POSTPAID! 



ALL BAND 
VERTICAL 

WVG MARK H 



New low cost vertical on- 
tonna which can be tuned to 
any amateur band 10—80 
meters by simple adjustment 
of feed point on matching 
base inductor. Efficient 
radiator on 10, 15, 20,40, 75 
:ind 80 meters. Designed to 
be fed with 52 ohm coaxial 
cable, 

Cbnvenlently used when in- 
stalled on a short 1-5/6" 
mast driven into the ground. 
Simple additional grounding 
wire completes the instal- 
lation. Roof top or tower In- 
stallation. Single bond oper- 
ation ideal for installations 
of this type* Amazing ef- 
ficiency for DX or local con- 
tacts. Installed in minutes 
and can be used as a port" 
able antenna. 

Mochonical Specif e cot ions: 

Overall height — 18' As- 
sembled (5* Knocked down) 
Tubing diameter — H4" to 
7/16". Maximum Wind Un- 
guyed Survival .— 50 MPH. 
Matching Inductor — Air 
Wound Coil ZVz'' dia. Mount- 
ing bracket designed for 1- 
5/8" most- Steel parts irri- 
dite treated to Mils Specs- 
Rase Insulator material — 

Fiberqlas impregnated sty- 
rene- 

Etectrlcol Spec if icot ions; 

Multi-band operation -* 10- 
80 meters. Manual lop on 
motching inductor. Feed 
point impedance — 52 ohms 
(unbalanced). Maximum power 
- 1000 watts AM or CW-2KW 
PEP. Omni-dl recti on ai. Verti- 
cally Polarised. 

■ TTJ>1H WORLD RADIO 
^^^^1 LABORATORIES 

^^^^^^^^ Couneii Bluffs^ Iowa 
D Check enclosed, □ Ship 
one WVG MK, II @ $15.95 
Postpaid. 

Cal 1 



Address^ 
State^_ 



J 
I 



DECEMBER 1962 



43 



AM OscilloscoDe Patterns 



Harvey Pierc© W0OPA 
5372 E. Bald Eagle Blvd. 
White Bear Lake 10, Minnesota 



THESE ARE TYPICAL patterns as 
seen on the "Simplescope" (See Sept., 1961^ 
*'73 Magazine") hooked to an AM ti'aiisraitter. 
Any other 'scope with its vertical j>lates con- 
nected to an rf pick-ui) will give envelope pat- 
terns as shown, even from a receiver if output. 
For the trapezoid figures ^ though, the hori- 
zontal plates must be connected direct, without 
amplifiers, through a dj-opping resistor only if 
needed, to the modulating voltage. Most com- 
mercial scopes do not provide for this type of 
connection. 

A 'scope gives instantaneous readings so the 
majority of these drawings represent a fleeting 
picture, not a steady state. They are idealized 
and simplified, yet the viewer should be able to 
recognize, from them^ when a similar condi- 
tion exists in his transmitter. Oscilloscope pat- 
terns change constantly as the modulating 
voice changes^, yet over all they obey certain 
rules for certain conditions. Let's look at the 
pictures and see. 

A, Til is is the undeflected spot. It should be 
small and round* "Z" is the horizontal reference 
line (imaginary) drawn through the spot^ 
representing the point of zero rf output* 
B* This is the unmodulated carrier of a trape- 
zoid pattern. Length "X** represents rf output 
(carrier) voltage. The rf coupling to the 'scope 
should be adjusted so that "X" is not over 1/3 
the diameter of the 'scope face, 
C If the vertical trace is wider than the spot 
seen as in drawing "A", there is hum or noise 
in the audio system or in some cases the power 
supply. 

D- Speaking in the microphone should produce 
a pattern like this. (A trapezoid.) The horizon- 
tal or "Width" control (audio coupling) should 
be adjusted so the slanting sides of the figure 
are from 30 to 45 degrees to reference fine 

E, This is exactly 100% raodulatioji* In a per- 
fectly modulated transmitter, "Y" should be 
twice "X", (It rarely is!) 



F, This is overmodulation. **Y" is now more 
than twice "X'\ "A'* should be equal to *'B" 
plus ''C\ but in practice it rarely is. Portion 
*'C" is a bright horizontal line, and indicates 
the amount or degree of overmodulation on 
negative peaks of the audio cycle* 
G- This is phase shift between the audio to the 
'scope deflection plates and the audio doing the 
modulating. Any amplifier or coupling except a 
simple resistor between the horizontal plates 
and the modulating audio will cause this pat- 
tern. The "loop" changes shape with voice 
frequency changes. 

H, Here is a picture of a slight case of what is 
termed "a lack of modulation capability." Note 
the rounded left-hand comers, 
I* A severe case of "lack of modulation capa- 
bility," 

J, A typical pattern of lack of modulation 
capability. There are many causes* For plate 
modulation the commonest cause is lack of grid 
drive or (what amounts to the same thing) 
over-coupling to the antenna or load. Other 
factors may be bad or overloaded final tubes, 
poor power supply regulation, or an overloaded 
power supply. In screen, grid, or other forms of 
"efficiency" modulation this pattern usually 
means improper operating voltgages. In a few 
circuits nothing will help, for they are just in- 
capable of linear modulation. 
K. This is the pattern for choke or Heising 
modulation with the final heavily loaded and 
the modulator tube(s) operating class AB2 or 
B, Note that 'T" is a little greater than ^^X", 
and "A" is much smaller than "B" indicating 
essentially negative modulation. 
L. The ideal pattern for negative peak clipping, 
''A" is greater than "B'* showing extra positive 
modulation. Right hand point is bright and 
rounded showing clipping action. 
M, "Envelope" pattern for unmodulated car- 
rier. This and the rest of these pictures show 
patterns seen with 60-cycle ac applied to the 
horizontal plates instead of the modulating 



44 



73 MAGAZINE 



01 














o 











m 








DECEMBER 1962 



4S 



audio voltage. Rf coupling tlie same as before. 
Width is set so that all four comers are seen 
for hum analysis, but may be expanded if de- 
sired for more detail on other patterns, 
N. 60-cycle in- phase hum. Rare, Top and 
bottom of pattern not parallel. 
O. The commonest pattern for 60-cyde hum. 
The open *1oop*' shown here at the right end 
may occur at other places. 
P. 120-cycle in-phase hum. Rare. Edges MAY 
bow out rather than in. 

Q. 120-cycle hum, commonest form. Same as 
''0*\ but with two loops per edge* 
R» Noise. Top and bottom edges, rough and 
constantly changing. Sometimes called ''grass/' 
S, Modulation. Note that TWO patterns ap- 
pear, one as the trace moves left-to-right, an- 
other as it reverses to go right-to4elt. The 
audio waves will be in constant and confusing 
motion but it is only essential to judge the dis- 
tance *Tr" (the audio peak-to-peak voltage) 
and compare it with '^X*' (the carrier) or what 
is easier the amount "Z'' of carrier not modu- 
lated by the audio. Either way you can judge 
modulation percentage. 

T. 100% modulation, "Z" has reached zero, and 
"Y" is now equal "X". Bright dots appear along 
the center line as the negative peaks meet in 
the middle of the pattern, 
U- Over modulation* *'Y" may be greater than 
**X"j but the most important indication is that 
the bright dots of pattern "T" have now be- 
come dashes, indicating periods of no carrier, 
V. Clipping. "Z" has a steady value, and the 
peaks of the audio wave can be seen to be 
flattened. This is sometimes caused by satura- 
tion of the modulation transformer (core not 
big enough for the power). 



W* High frequency "Spiking/* The spikes are 
2 or more times the height of the rest of the 
audio waves. Usually caused by *^ringing** 
(momentary oscillation at a high frequency) in 
an audio transformer, triggered by the high 
frequencies that naturally occur in speech, 
X. This is the envelope equivalent of trapezoid 
pattern ''K'\ Trapezoid patterns *1" and *7'* 
will look like this^ too. 

Even with tlie rapidly changing double trace 
of the envelope pattern it should be possible to 
distinguish between smooth and rough modu- 
lation by fleeting glimpses of the audio weaves. 
Distortion usually shov^^s up as excessive highs, 
similar to pattern '*W/' With a commercial- 
t}pe scope the regular sawtooth sweep set at 
near 60-cycles with internal sync will hold 
most audio waves steady for good viewing. 

In actual practice the wave forms in the 
envelope pattern will be much more complex 
than those shown. A sharp eye should have no 
trouble in recognizing the t>pical conditions 
illustrated, tho. In general the envelope pat- 
tern is best for telling what kind of audio waves 
you have doing tlie modulating, while the 
trapezoid pattern is best for showing how^ the 
rf is being modulated. 

In a typical ham shack the envelope pattern 
need only be used to check newly installed 
audio equipment (clippers, preainps, micro- 
phones, etc.) while the trapezoid pattern 
should be used constantly to monitor modula- 
tion percentage and the modulation capability 
of the rf stage being modulated (adequate 
drive, etc). 

Envelope for your audio, trapezoid for your 
modulation. 

. W*OPA 



* ■ 



Letters 



Dear Wayner 

Regarding the article on page 22 of the September 
1962 issue: Treasures in the Junk Yard, Auto radios 
run fine on 6 vac if they have permanent magnet 
speakers, but do not work ^vith field coil speakers. 
They play, but sound like hell. $10 or $15 seems 
like a lot for old car radios, I have purchased a 
dozen or so in the last 15 years for 25(* to 75^ and 
have had a half dozen more given to me, 

John MarlaH K7ACI 

Wayne, OM, 

Vui a fumbling amateur, as dumb as dumb can 
be, Many of my projects fail to work for want of 
proper knowledge. But I have inspirations as often 
as it rains — and a few of them do work. It's prob- 
ability. The best sky wire I ever had was a cubical 
quad — I made it to the measurements printed in the 
book. That thing could hear a gnat sneeze in 
Mongolia — if pointed that wa^'; the side pickup was 
down 30 db. It lasted IS months, this bamboo wind- 



catcher — ''til a November gale bent the steel that 
held it vertical. Later came the circle quads, shaped 
of alunninum tubes. These were simply polished, 
*sophisticated' versions of the quad. I tried one on 
ten, but in my fumbling way. It never acted as a 
beam — too many compromises in its framework. In 
recent months IVe seen the helix touted for ama- 
teur use. The helix shows handedness,* which the 
quad never did, so is useless if the other guy is a 
southpaw. Too, in this tracking jazz, a signal shows 
^rotation* effects when it travels through a layer 
of free ions. The Oscar signal is all screwed up 
when it reaches our waiting wires. The only logical 
efficient antenna for adequate reception of Oscar 
signals is a completely impartial quad-ty-e antenna. 
I've scanned the literature with a microscope, but 
have found no mention of any attempt to adapt 
the quad to high-gain configurations. Wayne, am I 
missing something — ^like maybe a few buttons? Or 
is this an area that has been buried under the 
QRN of helices, etc ? Bob Russ K^GKI 



46 



73 MAGAZINE 





RF 
PATCH 




FRONT PANIL 
PATCHING FOU 
TIMPORARY 
RE-ROUTING OF 
CIRCUITS ONLY. 




...by means of TMCs spp so-m 



POSITIVE 

"NORMAL-THRU'' 

COAXIAL 

SWITCH PANELS 



USE OF Rhodium-Teflon-Gold mini- 
mizes NOISE 

NEW Quick Disconnect Miniature co- 
axial CONNECTORS PROVIDE HIGHER 
DENSITY- ^ 

B MORE IN A GIVEN 
PANEL AREA 

• ACCEPTS ALL SMALL DIAMETER CABLES 




Writ* For Complete Catalog 




sjiffOE So. 







THE TECHNICAL 

MATERIEL 

CORPORATION 



DECEMBER 1962 



amd Subsidiafies 
OnAWA, CANADA • ALEXANDRIA, VA. • GARLAND, TEXAS • 
U MESA. CALrF. • POMPANO BEACH. FU. • LUZERN, SWITZERLANO 



47 




IVffli All the Trimmings 



Wise Amateur Radio operators know that they can 
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Kit HM-f 1 



3. 100 KC CRYSTAL CALIBRATOR: Perfect for 
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I 

I NAME 
I 



ADDRESS 



:i 



CITY 



ZONE 



STATE 



- ! 



I 



I 



Briefcase 
Twins 



Sidney Rexford W2TBZ 
Coltorii New York 



WHILE I may be classified as a dyed in- 
the-wool fone man, the old CW bug 
occasionally bites and the only sohition is to 
work away on the nasty stuff until the spell 
passes and sanity returns. In the middle of an 
unusually mean attack it became evident that 
the station CW setup was as antique as high 
button shoes and something needed to be done 
about it- 

The more the problem was studied the more 
it began to look as if a small self contained CW 
transmitter and receiver would be an ideal 
answer to the problem. If it was small enou^ 
and portable enough several other pipe dreams 
could be realized too, 

A rather imposing '^Vant List" was pre- 
pared of the desirable features a small CW rig 
should possess. It went like this: 

1» High Portability— To fit in a briefcase if 
possible. This limited dimensions of the con* 
tainer to about 3'' x IC x 14''- 

2, Self Contained — To include everything 
necessary for operation except an antemia and 
a 110 volt AC wall socket. 

3, Full CW Cav^age — Of the transmitter 
and receiver of some popular band **Open'' 
during civihzed times of the day— preferably 
40 Meters. 

4, Rugged Reliability — Must be conserva- 
tively designed and built with components 
operated well below critical levels to reduce 
maintenance and repair problems. 






Three quarter view showing panel layouti built- 
in key, and ventilating holes on side and top 
of the chassis. The relatively symmetrical lay- 
out gave the unit iis name. 

For tliose who question why the little rig 
was not designed around a transceiver circuit, 
I hasten to add diat the idea was given con- 
siderable thought before being discarded, Tlie 
chief argument against a transceiver circuit is 
the fact that retuning the receiver to duck 
QRM moves the transmitter frequency too and 
with the low transmitter power it is reasonable 
to assume tliat the guy on the other end of the 
QSO will have his receiver selectivity screwed 
up so tight that a small shift in frequency could 
easily put the signal outside his band pass 
and lose the QSO. 

With the exception of the built-in key and 
the non-standard power transformer the parts 
are standard and easily obtainable. While this 
article isn't designed to provide the reader with 
much more than the impetus to take the solder- 
ing iron in hand and whomp up his own 
^'Briefcase Twins" for his favorite band, this 
rig probably could be duplicated right down 
to and including the built in key by some hardy 
souls. This built-in key came from a surplus 
water-tight knee bracket job with no identifica- 
tion other than "BRELCO NY" in raised letters 
on top of its water-tight box. The key mechan- 
ism was removed from the box and mounted 
in a %^^ hole as shown in the photos. Key 
adjustments are accessible through holes drilled 
in the bottom of the chassis. 

Key fo Key 

The little rig provided an opportunity to try 
out a somewhat novel keying circuit which 
proved highly successful and is worthy of 
dupheation in any future CW transmitter de- 
sign. 

Sequential keying is not new. There are 
several circuits available all of which are suc- 
cessful and widely used. Most of them I have 
tried resulted in satisfactory ke>ing of the 
transmitter but failed to properly mute the re- 
ceiver, provide monitor facilities, and provide 



50 



73 MAGAZINE 



for antenna switching without an annoying 
clatter. What was desired was an automatic 
circuit that would do all of these little chores 
and do them the first time the key was closed, 
then undo them after keying was CQmj>leted. 
This would provide clean keying character- 
istics and still permit a reasonable breakin 
capability, 

The basic keying circuit is shown inside the 
dotted lines of Fig. 1* The mode of operation 
may not be apparent at lirst glance so a few 
words of explanation are in order. For the 
explanation assume a |umper between H and L 

With the key open —150 volts of blocking 
bias is applied to the final amplifier grid and 
the monitor oscillator. The diode connected 
of the 12.4X7 does not conduct because 



the receiver tube grids and the receiver oper- 
ates normally. Disabling cutoff bias is applied 
to the transmitter grids. 

When the key is closed cutoff bias is re* 
moved from the monitor oscillator and normal 
operating bias of —15 Volts is applied to tlie 

Fig. I 

NOTE: The voltages measured at the circled 
points wtll depend upon the transformer used. 
The table values given are approximate^ and 
nneasured from point to chassis. 



negative (or equal) voltage is applied to the 
plate with respect to the cathode, Tlie .1 mfd 
capacitor betwm the cathode and ground is 
charged negatively above ground through the 
3 Megohm resistor. This negative voltage is 
also applied to the grid of the second half of 
the 12AX7 biasing it beyond cutoff leaving tlie 
plate relay open. No bias voltage appears on 



Voltage 
Point 


VoHage 
Key Up 


Voltage 
Key Down 


A 


6.3vac 


6.3 vac 


B 

C 
D 


+400v 
+400v 
— I50v 


+400v 

+390y 
O 


E 


— 150^ 


O 


F 


— 1 50v 


— I5v 


G 


— I50v 


O 


H 
1 

W 


+400v 

-i-400v 

o 


+300v 

+390v 

ISOv 


X 


— ISOv 


o 


Y 

Z 


+400v 
6.3vac 


4-390V 
6.3vac 



POWER SUPPLY 



CHICAGO PHC-120 
FfiEED PG P-IO 






(!) 



I2-I2/450V 



NOTE 



II' 

C? 

O e.3V, AT 5A 



© © 




I2AK7 
FtLAMENTS 



(D 



INDICATES 

SCREWDRIVER 

ADJUSTMENT 



S3V 



V 



— wv- 



M-600 I 

K T I 



DOV 



&/450V 



* 



STAf^COR 
P-6465 




<D 



25W 

vyv ^|t 

rrWE DELAY 
CONTROL 



lOK 

IW 



<*) 



CALL 

•11 — » 



— o o * 

/ 

SPST 9 



rm. I 



jlZAXT 



© ©© 



RELAr 

CURRtNT 

C9NTflOL 




|I2AX7 




© 



External 

PCEY 
JACK 



BUILT IH 
KEY 



KEYER CFRCUIT 



DECEMBER 1962 



SI 



1 






TRANSMITTER 



2E26 



> 

z 



iTOiwnf 
ZERO 

TfMP 



{40M1 



a5t f DIA 
i" LONG # 18 
EI^AMEL 




NOTE: All by-pass capacitors are 600v disc 
ceramics ynleis otherwise! indlcat&d. 




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filial amplifier grid. The plate uf tlie diode con- 
nected half of the 12AX7 appears positive with 
respect to the cathode; the tube conducts and 
quickly discharges the ,1 mfd capacitor. This 
removes the cutoff bias from the grid of the 
relay tube half of the X2AX7, Plate current 
flows and the relay closes. When this DPDT 
relay closes cutoff bias is removed from tlie 
transmitter oscillator^ permitting it to operate. 
At the same time cutoff bias is applied to the 
receiver tube grids niutiug all l;ut the a£ por- 
tion of the receiver. 

During normal ke>ing speeds the .1 rafd 
capacitor is discharged each time the key is 
closed. The time constant of charge of this 
capacitor through the 3 megohm resistor is 
relatively slow and cutoff bias for the relay 
half of die 12AX7 does not have time to de- 
velop between characters. When normal keying 
ceases, and after a short delay, the ,1 mfd 
capacitor will cliarge sufficiently to cut off the 
plate current, the relay to open and the cycle 
is completed. 

Since it is also desirable to change the an- 
tenna from the transmitter to the receiver 
whenever the receiver is in operation a second 
relay for this purpose has bren located near 
the antenna connection lu the transmitter 



chassis. Two electrically identical relays are 
placed in scries to perform both of the re- 
quired functions. It was found that one relay 
opened a fraction of a second earlier than the 
other* The relay that opened first w^as chosen 
for the antenna cliange over relay. This pre- 
vented an additional snap in the receiver by 
connecting the antenna before bias was re- 
moved from the receiver grids* This relay was 
not designed to handle rf but with this fre- 
quency and power level it works well and no 
future trouble with it is anticipated. Any relays 
capable of operating on 15 ma or less will do 
the job. The relays used closed on about 9 ma 
of plate ciurent even though they were marked 
5f)(}() ohms and 110 Volts dc operating voltage. 
The driver, final amplifier and keying moni- 
tor oscillator, being divorced from the relay 
all key in a normal blocked grid manner. Sta- 
tions worked report the keying to be com- 
pletely free of clicks, tails, chirps or other 
keying ills at any speed. With a bug plugged 
into the external key jack, and the weights off 
keying is still faultless. The first dot from the 
wide open bug is enough to set the whole 
keying circuit in operation and put rf into the 
antenna. This is better performance than was 
expected. 



DECEMBER 1962 



S3 



o^ 











^ 


T 


VI 


< 

— 


i L 








1 


1 








i 


u 


^\^/\ 

-L 


Sjn 


r^ 


i 








^ 
« 







54 



73 MAGAZINE 



^tSBt^S^ 



SAVINGS ON NEW 
SEMICONDUCTORS ! ! 



ZENER DIODES 

% watt 20% 4.3piv HAS 

% waft 20% 6.2ptv 1J5 

% watt 20% 8,5piv 1.15 

% wdtt 20% 15. plv M5 

% watt 20% 22. plv M5 

I watt 20% 4,3v K35 

T watt 20% 6.2 V L35 

1 watt 20% 8.5v 1.33 

1 watt 20% 15* V V.35 

1 watt 20% 22. V 1.35 

Double onade 6,3v ±20% .50 

TRANSISTORS 

Similar CK721, CK722, CK786 2 for 60^ 

PNP repl'fn't 4-tront radio 2.10 

PHP repVm'f S-tran* radio 2.45 

PNP rept'm't 6-traiis radio 2,75 



« * 



DIODES 

German'm replaces TN34A 

Similar 1N137, 1N137A, 1N138, 

etc. . , . . * . ^ ^ . ^ » « » . * 

Gen. purp, gfass $ilkon , 

R-f gen. parp replaces 1N82A 



m * 



* w t 



10 far 
$0.98 

1.20 
.98 



RECTIFIERS 

lOOma lOOOpiv hJ-V silli^n $1,70 

lOOma ISOOpiv hi-V siticon 2.25 

lOOma 2000piv hi-V silicon 2,95 

lOOma GOOOpiv hUV silicon 4.45 

500ma 200piv epoxy, sim, 1N2069 .30 

500ma 400piv epoxy, sim. 1N2070 ,40 

500ma dOOpi v epoxy, lim. 1 N2071 ,70 

750ma 50piv replacoi 1N599 ,11 

750ma lOOpiv reploces 1N600 ,20 

750 ma 20Qpiv replaces fN602 .33 

750ma 300plv replace* 1N603 .39 

750ma 40Opiv replaces 1N604 .48 

750ma 500ptv replaces 1N605 .60 

750ma 600piv replaces IN606 .75 

750ma 700piv — ,95 

750ma SOOpiv — 1.25 

750ma 900plv — 1.50 

750ma lOOOpiv — 1,95 

750ma ISOOpiv -* 3,25 

750ma 2000piv — 4,15 

2amp SOpiv replaces 1 N2026 .17 

2amp lOOpiv replaces TN347 ,30 

2amp 200piv replaces 1N2027 ,45 

2amp 400plv replaces 1N2029 .90 

2aiT>p 600piv replaces 1N2031 1.35 

2amp eOOpiv replaces 1N1236 1.75 

2amp lOOOpIv replaces 1N3366 2.90 

2amp ISOOpiv replaces 1K337I 4.70 

2amp 20OOpiv — 6,50 



RECTIFIERS 

2am p SOpiv axial lead 

2omp lOOpIv dxiol lead 

2amp 200piv axial lead 

2amp 400piv axial lead 

2amp 600pi¥ axial lead 

2amp SOOpiv axial lead 

2omp IDOOpiv axial lead 

2omp ISOOpiv axial lead 

2amp 2000piv axial lead 



$0.15 
-27 
.40 

1,20 
T.60 
2.80 
4.30 
6.00 
.75 
1,20 
1.75 



2amp Cont. Rect, similar 2N1600 3.50 

NOTE! AM semiconductars listed above are NEW*CIEANI Fully guaranteed. Subject to 

MADE Olid Individually letted to meet above roHngi 



T2amp 50pEv replaces 1N1199 

12amp TOOpiv replaces INI 200 

12amp 200piv replaces INI 202 

12amp 400piv replaces 1N1204 2.60 

t2amp 600pjy replaces 1N1206 3.75 

12amp SOOpiv ~ 6.90 

12amp lOOOpIv — 9.50 

20amp to 400 piv, Cont. Rect. 14.00 

25amp 50piv replaces 1N248A 1,50 

25amp lOOpiv repia«« 1N249A 2.50 

25amp 200plv replaces 1N250A 3.70 

25amp 400piv replaces 1N2136A 4.75 

25amp 600ptv replaces 1M2138A 7.75 

25a mp SOOpiv » TO.OO 

SOamp 25piv ~^ 2,70 

50omp 50pjy similar TN411B 3.98 

SOamp lOOpiv similar 1N412B 5.98 

50amp 200piv similar IN413B 6.50 

50amp 400plv — 9.75 

50amp 600piv — 16.00 



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21 SO. BROADWAY 
LAWRENCE, MASS 



Power Suppfy 



The Twins are built in two standard 3'' x 
5'^ X 10''' chassis joined together in the center 
by the power supply and keyer chassis which 
is 4^' X 5'' X 6'^ with an outboard power trans- 
former projecting out the rear which extends 
its overall length to about 10"* The front end 
of the chassis becomes the panel and contains 
the ac switchj the transmitter calibrating 
switch J the 0-75 ma plate meter, the built-in 
key and tlie external key jack. The circuit 
diagram is shown in Fig. 1, 

The power supply chassis was constructed 
first and was by far the most difficult of the 
three to wire. To anyone considering construc- 
tion of such a piece of gear I recommend shop- 
ping around for physically small components. 
Being a natural born cheap skate I used what 
was in the junk I) ox as long as it could be 
fitted in without resorting to too big a hammer. 

As much wiring as possible was made before 
the chassis began to get too fuli Leads to what 
were to become inaccessible points when sub- 
chassis and brackets were installed later were 
brought out and carefully tagged. It is a good 
idea to prepare a step by step construction 
gm'de, Heathkit style, by mentally wiring the 



unit several times before final construction is 
undertaken. Brackets containing the filter 
capacitors, the keyer tube and its relay, and 
the rectifier tube were prewired and inserted 
in that order. Each wiring step was carefully 
checked for accuracy before progressing on 
to the next. 

It is a good idea to take stock of the inter- 
connections going from the transmitter to 
the receiver chassis which must pass through 
the power supply chassis but not stop along the 
way. The chore of trying to fi^h them tlirough 
later can be most exasperating. 

The 5000 ohm variable resistor in the cath- 
ode relay tube lialf of the 12AX7 provide for 
adjustment of maximum relay current* It is 
adjusted by holding tlie key down and reduc- 
ing its resistance until both relays close. The 
250,000 ohm potentiometer provides for ad- 
justment of the time delay length. If maximum 
available delay is not sufficient for your taste 
the 3 megohm resistor may be increased to 
4 or 5 megohms. 

The power transformer used was a surplus 
Halhcrafters 52 C 243 made by the Chicago 
Transformer Company, The transformer has 
two 110 volt primary windings, one of which 
was pressed into service to provide the —150 



DECEMBER 1962 



55 



volt bias source. Fig. 1, however, shows a 
back - to - back filament transformer for this 
purpose. This is to preclude frustration of 
builders wlio cannot locate an exact dviplicale 
of the transformer I used. Those who run into 
space problcnis may relieve the congestion by 
substituting silicon diodes for the 5Y3 rectifier 
tube. 

In the construction of the power supply 
chassis tliree Vi\ #6-32 bolts w^ere installed on 
each side to fit matching holes in the receiver 
and transmitter chassis and provide for future 
alignment. These bolts later become inacces- 
sible in hotli the receiver and transmitter so no 
effort was made to bolt the complete unit 



tugilhen 



Transmitter 



The transmitter was the second chassis con- 
structed and wired. The circuit, shown in Fig, 
2, could have been made much simpler and 
with few^er stages but I doubt ii it would have 
worked nearly as satisfactorily. About three 
volts of signal is provided by the vfo wliile a 
fnrt}' meter crystal provides in excess of twenty 
volts. The high values of grid resistors in the 
6BA6 and succeeding stages provide linn ling 
action and uniform drive to the grid of the 
2E26 final amplifier. This keeps operation in 
the class AB- region througliout the entire band 
and regardless of the amount of drive provided 
by the vfu or cr\^sta] used. Class AB:; is only 
slightly less cllicient than class C operation 
and resuhs in an exceptionally clean signal 
No hint of TVI can be fomuh 

The front panel controls of the transmitter 
consists of a tiny Japanese import vernier for 
die vfo, a cr\'stal socket, a switch to choose 
between the crystal and the vfo, final tuning. 




Internal view showing placement qf parts and 
generaf location and size of brackets and sub- 
chassis. 



antenna loading and an SO-239 coax connector 
for the antenna. 

The complete layout of tubes, voltage drop- 
ping resistors and other heat producing com- 
ponents was determined and ventilating holes 
drilled in the bottom, rear and right side of 
the chassis. Areas for the ventilating holes were 
squared off in Vd' srfviares and Ji''' holes were 
drilled in each corner and the center of eacli 
square. Dont be skimpy on the ventilating 
holes! The bull work necessary to drill a couple 
of hundred of them will really pay off in 
stabiHty later on. You lazy guys might try 
using squares of **Reynakrs Do-It- Yourself' 
perforated aluminum sheet bolted in place. It's 
a little thin for the job but presents an easy 
out* 

Tlie oscillator sub-chassis w^as installed and 
tested first. Coverage of the vfo was adjusted 
by removing plates of the 50 mmfd APG tun- 
ing capacitor until 3.5 mc to 3.6 me covered 
approximately an art^a between 1 and 9 on the 
vfo vernier dial. After doubling in succeeding 
stages of the transmitter this permits coverage 
of the 40 Meter CW band from 7.0 mc to 7.2 
mc. 

The second subehassis constructed, prev\ired 
and inserted contained the rest of the trans- 
mitter tubes and the rf choke for the final 
amplifier plate circuit. Considerable thought 
must be given the layout of this chassis with 
parHcular attention to being able to remove 
and replace tubes later and to adjust tuning 
slugs w^itliout tearing the vvIiuIb shebang apart, 

A small L bracket under the antenna load- 
ing capacitor accommodates the antenna 
change over relay, 

Plate current on the completed final amph- 
fier rises to about 50 ma off resonance and 
gives maximum output when loaded to about 
33 ma. Loading above the 35 ma level results 
in loss of output. Once the stages are all 
aligned at about 7>1 mc, tlie entire band can 
be covered with only minor touching up of 
the final tuning. 

Receiver 

The receiver front panel controls consist of 
a Japanese import vernier for tinn'ng, an if 
gain, af gain, phone jack and speaker switch. 
Access of the Clapp oscillator tuning slug is 
also available under the timing vernier. The 
panel as can be seen from the three-quarter 
photo is a niii 1 f}! image of the transmitter con- 
trol layout. As an> fool can plainly see, that's 
where tlu^ **TWINS" comes from. 

Construction of the receiver, shown in Fig. 
3, produced far more headaches than liad been 
anticipated. If its construction was to be under- 



56 



73 MAGAZINE 




this complete 



tA^ 



am 



ANTENNA SYSTEM 

WITH 56 foot Spaulding Tower 

WORTH OVER $500.00 

or one of 24 other valuable prizes 




IN HY-GAIN's 
SECOND ANNUAL 




CONTEST 



Contest open to any Licensed Amateur^' on Planet 
Earth. All entries must be postmarked no later than 
23:30 GMT, 31 December, 1962. 

NOTHING TO BUY. .Here's all you have to do- 

Simply pick up an Oflicial Skyhook II Entry Blank from your 
favorite Hy-Gain distributor and, in twenty -five words or less, 
complete the following statement: ^If I were the New Product 
Manager of Hy-Gaini I*d ask my engineering department to 
develop an antenna design that w^ould (25 w^ords or less)." 
Send your entry to Hy-Gain Antenna Products, NE Highway 
6 and Stevens Creek, Lincoln, Nebraska, All entries will be 
judged on the contribution the suggestion offered will make 
toward tin i versa Uy improving reception or transmission and 
will remain the property of Hy-Gain Antenna Products^ Inc, 

3.5-500 MC including RBX-1 Rotator and Directional Indi- 
cator, DS-1 Discone with range of 50 thru 500 mc, TH-4 
Tribander, 402-6 40 Meter Monobander, 2BDP Multiband 
Doublet and 56' Spaulding Tower. 
2nd PRIZE- DB-24 Duobander, 20-40 meters 
3rd PRIZE- 18HT All Band Vertical 
4th PRIZE -TH-4 Thunderbird Tribander 
5th PRIZE" TH-3 Thunderbird Tribander 

'Sorry, we must exclude entries from Cities, States or Countries 
where contests are prohibited by law. 

BE A WINNER! pick up an Official Entry 
Blank TODAY and submit your suggestion NOW to: 




iSin antenna products 



8405 NE Highway 6 

lincoln, Nebraska 



DECEMBER 1962 



57 



taken again some different techniques would 
be employed. Let's see what actuall) was done 
and what changes would be made. 

Ventilating holes were liberally drilled in 
the receiver chassis bottom, rear and left side. 
The same system was used as was employed 
in the transmitter. Similar holes were drilled 
for the speaker which was located in the front 
bottom of the chassis. The speaker, an 89 cent 
4-8 ohm, 4'' diameter job of unknown manu- 
facture, output transformer and phone jack 
were installed and wired together before the 
other sub- chassis was installed. 

The second chassis contained the audio 
ampHfier and keying monitor. Small values of 
coupling capacitors and cathode by -passes 
tailor the audio output to peak around 1 kc. 
No trouble with the audio portion was ex* 
perieuced but the relaxation t> pe keying moni- 
tor oscillator proved critical and die chassis 
had to be removed and the values of the 
circuit changed to obtain proper operation. 
Builders of this monitor circuit may have to 
juggle components slightly to achieve a pleas* 
ing note. If the area underneath this sub- 
chassis is cut out of the main chassis so that 
access can be made available, the wiring 
changes of this nature can be made without 
removing the entire assembly. The cutout can 
be covered with a perforated plate held in 
place with self-tapping screws. 

The // stages^ bfo and detector cii'cuits were 
assembled and installed next* This portion of 
the receiver produced all of the headaches and 
the sub -chassis was removed and worked on 
a dozen times before satisfactory operation 
was aclueved* Again a plate covering an access 
hole on the left side of the main chassis would 
prove a godsend. 

The receiv^er front end was designed around 
the tried and true "Converterette'' circuit pub- 
lished several years ago in CQ. Receiver cover- 
age was adjusted to correspond roughly to the 
same vernier dial readings as the transmitter 
by removing plates from the tuning capacitor. 
The only precaution necessary is an adequate 
sliie'Id Ijetween the rf and mixer tuned circuits. 
No trouble was anticipated or experienced with 
this portion of the receiver. 

The selectivity of the 1700 kc if strip, while 
not considered inadequate, could be improved 
by tlie addition of a crystal filter preceding it. 
The crystals intended for the job were found 
to be sour so the filter was by-passed tempo- 
rarily. Adequate gain in the if strip is available 
to take care of the filter insertion loss. Without 
it the rf gain is normally run at minimum. 
Anyone contemplating the design of a stmilar 



receiver would do well to consult "Phasing for 
Audio Selectivity" by Jim Kyle, K3JKX/6 in 
the November 1961 copy of 73. Tliis little 
device would go a long way toward increasing 
selecHvity and, if built in as part of the af 
amplifier, might eliminate any need for a crys* 
tal filter and permit one stage of if to be 
efiminated. 

All brackets and sub-chassis were hack- 
sawed from an old aluminum bottom plate. 
The garden variety of "Do-It-Yourself* alumi- 
num sheet is a little too tlim and flimsy for the 
job but probably could be used. 

The internal photo shows the general inter- 
weaving of components mounted on the 
various sub-chassis and brackets. Tubes are 
placed under the if cans in the receiver and 
are so arranged that all tubes can be removed 
without having to remove any complete as- 
semblies although some tubes from other 
assemblies must be removed first 

Screwdriver adjustments are accessible un- 
derneath the unit and through holes in the 
cover plate and sides of the receiver chassis. 

The cover plate was cut from one piece of 
sheet aluminum and installed with self-tapping 
screws. It offers the main "stiffening*' tying the 
three chassis together. A short strap, bridging 
the three chassis, across the bottom finishes tiie 
stiffening fob. 

Rubber feet in each corner of the completed 
rig prevents marring the furniture and keeps 
the womenfolk happy. 

The "buttoned up" rig becomes mechanic- 
ally stable and can be picked up and shook 
vigorously without changing the note of the 
receiver or transmitter. Drift is noticable for 
about twenty' minutes then both units stabilize 
satisfactoril>% The mistake of laying the log 
book on top of the rig and shutting off ventila- 
tion through the holes will prolong the drift 
indefinite! v. 

The entire rig weighs 123^ pounds. With its 
built-in key and monitor oscillator it becomes 
an ideal unit for providing code practice or for 
giving Novice code examinations* The note 
from the monitor compares favorably with 
most code practice oscillators on the market. 
Design of the transmitter circuit precludes 
damage to the rig because of failure to tune 
the final to resonance or operation without an 
antenna. 

The first afternoon of operation into a nm- 
of the-mill doublet bagged seven states from 
the Sunday QRM with an average report of 
569X, Which only proves that they will never 
know that you are a QRP if you don't tell em! 

. . , W2TBZ 



58 



73 MAGAZINE 



m 



TEST EQUIPMENT-STEREO COMPONENTS 
COMMUNICATIONS EQUIPMENT 



TEST EQUIP.— NEW, ORIG. BOX 



VHF britfae, Hewlttt-Packard #W3A 

Phase mtUr, Industrial Instruments #200A8, 

Power sypplits. Lambda :r28 .. 

Ekctronic switch. Teletronics morfeT iirESlSO. 



$595.00 
325.00 

295,00 



STEREO— NEW— WAR RANTEED 



Mfgr*d by 

sow, 



Crosby 



Stereo receiver. 

Stereo receiver* 2Sw, 

zr6500EMX 

AM/FM tuner. Croshy :!rlOO- 
AM/FM tuner/Multiplex, 

:rlOOMX ___„ «.__orig. 

Stereo pre-atnp/amp, 40w 

:=r22S arig. 

Stereo pre-amp/amp, 28w^ 

^6aOOEM - orifl. 

Transislor micamp. it30 ^orig. 

Muflipltx adapter^ #1VIX101 orig. 

Multiplex adapter, #MX102^^orJo. 
Multiylex adapter, #MX103__orio. 



-PfiO. 5-125.00 now $243.95 



orig, 280.00 now 133.95 

orig. 159.95 now 49.50 



179.50 now 74,50 
150.00 now $9.95 



115.00 now 
10.25 now 
69.95 now 
49.95 now 
39,95 now 



44.50 

2,95 
34.95 
29.95 

23-95 



• TEST EQUIPMENT— USED 

All in good working condifion 

Electronic counter, Potter mortef #850^- $400,00 

Autlio freq. njeter, H,P, #500„ .— 99,50 

Audio freq, meter, G.R, #S34B „^- 75,00 

Electronic switch, Dumont #330 195.00 

Precision capacitor, GR #722.. „^^^ 125.00 

Diode tester, Teletronics Lab #DT-lOO„-_^ . 75,00 

Diod& tester, Teletronics Lab #DT-257 . — - 150.00 

Frequency metBr. GR #1141A 65.00 

Output power meter, GR #5S3A^^— 75.00 

VTVM, GR ±:726'i .^^^ 50.00 

VTVM, HP #410 .,,. . 95.00 

Audio oscillator. HP #200C— .^ - ■- 65.00 

Pwr. supply, TLI #PS440 (same as HP #712A) 125.00 
Pwr. supply, const, cur. & const, volt. TLI 

#PS 110 — ^— ^— 150.00 

Wave analyzer. HP i^5O0A___ . 295.00 

Distortion analyzer, HP #330B ^-, 195.00 

Double pulse generator, Teletronics TLI IrPClOO 195.00 

MJllimicroamfTteter, RCA ^WVg4 ^^^^— 55,00 



COMMUNICATION EQUIP.- 
USED & NEW 



All in good working condifioti 

Collins #51Jl receiver with cabinet 

Antenna coupler, it«w, Ikw. zrCU'362/FRT 

Frequency shrft keytr, ffteWt gov*t type 

#MD-200/FRT . == ==_=.__ ^_^^ 

Viking mobile emitter, used, in good condition 
Heath DXlOO xmitter. used, in flood condition.. 
Eldico ssh 500 watt linear, SO thru 10, used— 

RME receiver ::r4350, with xtal calibrator.^ - 

Hammarlund HO-I40 receiver — 



5275.00 

175,00 

475.00 
6500 
145.00 
195.00 
165.00 
169.00 



WRITE FOR COMPLETE LISTS 
OF STEREO & AMATEUR COMPONENTS 



TRANSMITTER PARTS 

TRANSMITTER PARTS— ALL NEW 

Purchosed to gov't spec. 

Capacitor, vacuum, JenningSp 10-400 mmf» lOkv 
Capacitor, var*, 4 sec, 24 L2 mmf/sec*. . » . . , 
Cap., var.. 12-224 mmf. Johnson #250E20. . . , 
Cap-, var„ 425/425/850 mmf. Cardwell 

#CI009959 . . - , 

Cap., var,, 15-353 mmf, Johnson #350E20 

Cap., var*, 45-800 nnmf. Johnson #800D35. ... 
Cap., mica, 2000 mmi 6000 v, JAN 

Cap., mica, 1500 mmf, 6000 v, Jan 

^ C m 7 5 B I 52 J „*,.,,,,.♦,...,--.-*---*»• 

Cap*, o»l, .5 mfd, 4000 v pic. ..,,.. 

Cap., oil 4 mfd. 4000 vdcw, #CP70E I EM40SV 
Cap. Oil. 10 mfd, 1500 vdcw, #CP70EI EH 106V 

Crysfal oven, 100 kc, Bliley #7C9II. ., 

Tuning inductor, var,, Johnson ^226-1 ...... 

Relay. Struthers^Dunn #2I8DXBI05 .... 

Relay, 25a, I I 5 vac coif, RBM ....... ^ , 

Relay, keying, .5a, 6000v pk dc llOvac coil. . 
Relay, time delay, adj., spdt, Str,-Du nn 

Choke, MIUT-27; 

lOhy, 250ma, 3500v test 40 ohm 

lOhy, I lOma, I500v test 50 ohm 

lOhy, 430ma, 2500v test 18 ohm . . 

I Shy, 60ma, 1500 v test, 1600 ohm 

7.5hy, 280m«, ISOOv test, 75 ohm . 
Meter, 2 inch, 0-1 made, rd., 

#MR25WI56DCMA 

Meter, 0-50 microamp, #MR25W050DCUA 
Meter. 0-300 acv, RD., #MR25W300ACVV 
Meter, 0-5 kvdc, RD., # MR25W005DCKV. . 
Meter, 0-500 made, RD., #MR25W500DCMA. 
Meter, 0-5 made, RD., # MR25W005DCMA. . , 
Meter, 0-500 vdc, RD., #MR35W500DCVV. . . 
Meter, elapsed time, GE, MSvac, 60 cy...,. 
Transformer, MIL-T-27j rect. fil. 5vct, BOOOins 
Transformer, MIL-T-27, plate. 6300 vet, SOOOma 
Transf., MIL-27, plate pri 220, 2770vct, 680 ma 
Transf, MIL-T-27, modulation for (2) 4-I25A.. 
Transformer, auto, pri MS v, sec 220/115, 

2500kva , 

Var. line transformer, adf. input 103.5 v to 

I26.5v or 207v to 253v, 60cy., I phase, output 
82,8v to l5L8v or I86v to 278v, 33 or 16.5 

amp, adj by crank GE #3ID2030G( 135.00 

Tube. Eimac #4-400A ____,-. 29.00 

Tube, Eimac #4-65A 13.50 



#«'>'« 



d « % « 



$59.95 
5.00 
4.20 

25.00 

7.50 

12.95 

1 2.50 

12.50 
2.95 

11.50 
3.50 

35.00 

29.95 
7.50 
4.95 
6.95 

14.95 

4.95 
3.75 
14.95 
2.00 
4.50 

3.25 

4.50 

3.75 

3.75 

3.25 

3.25 

3.95 

9.95 

5.40 

27.50 

10.95 

32.50 

12.50 



SEND CHECK OR MONEY ORDER 



25 



Oi 



with COD^— ^Exps. chgs. collect 
Mintmiuii order $10.00 



Servtnq Amateurs oitd Industry Since 1945 



ALGERADIO 



ELECTRONICS CO. 



37 Greenwich Sfreet 

Hempstead, New York 

Phene IV 9-0808 



DECEMBER 1962 



59 



A Ham Looks at the 



Heath Warrior 



Don M. Wherry W6EUM 
2l2i Srandvlew Drive 
Camarillo, Calif. 



A RECENT EX.\MINATIOX of the 
QSL cards received here at W6EUM during 
the past two years revealed aji interesting fact 
—for the cards received, over 44% of the sta- 
tions mvolvcd used some model of Heatlikit 
transmitter. This fiict stnick your writer with 
some httle impact. There must be some reason 
for such a situation and since he does possess a 
well known 140 watt SSB transmitter, the de- 
cision was made to look into it by the pur- 
chase of a Heathkit Warrior Linear Amplifier. 
This article is an attempt to review this War- 
rior as joe lilow ham might see it and not 
necessarily as an advertising agent for the 
Heath Company might. 



\Mien you, as the purchaser, receive the unit 
you \\ ill be impressed by one thing— it is heavy 
(shipping wciglit 99 pounds). This would im- 
mediately indicate rather solid construction 
and, upon unpacking, this belief is verified^ The 
chassis is made from hea\^^ gage steel, the 
panel and cabinet are soUd construction and 
the tiLLiisformers, while not oversize, seem to 
be adequate. The chassis, in fact, is outstand- 
ing in its solid, heavy construction. It is made 
in two parts, the sides and the top, with tlie 
top, for example, bolted to the sides with 
twenty-two machine screws and nuts. Not self 
tapping screws, but 22 machine screws— shades 
of military equipment. 



4000, 9KV 



tf#VT 



01 01 ., 



MS »c 




■ ■ O OtfTRJT 



Z0*i&O 



•COPC 



£0A 



005. i 4iev 



60 



Last chance for Charter Membership in lOAR 



73 MAGAZINE 



The genenil parts, coiitleiisers, resistors, 
tubes, etc., are standard quality brands— RCA, 
Jolmsoiij etc* No attempt at all was made to 
cut financial corners on parts. 

The mechanical assembly was straightfor- 
ward and offered no difficult) with but two 
exceptions. One machine screw holding the rf 
shield around the rf section was quite inacces- 
sible, taking the special nut starting tool which 
they furnish, and the use of long nose pHers 
to start. The second exception was a little more 
serious. The front panel has t\vo indicator light 
assemblies which go througli the front escutch- 
eon plate^ the front panel and on through the 
chassis. In my unit the holes in the three pieces 
were not quite in line which necessitated a few 
judicious swipes with a round file. The material 
filed off probably amounted to only a couple 
thousandths of an inch, but if the assembly 
doesn't go together it might as well he an inch. 

Electronically the circuit is a standard 
grounded grid linear amplifier. The drive is 
applied via a 50 ohm co-ax directly to the fila- 
ments of the four 811 A tubes. The rf is coupled 
to both sides of the filament through disc 
ceramic capacitors. The rf choke in the filament 
leads is physically quite small— by B and W 
standards—and consists of a bifilar winding 
about 234 inches long by 1 inch in diameter, 
wound around an iron core which apparently 
js made of normal slug material. The interest- 
ing part of this assembly is the feedback wind- 
ing which is spaced over the filament portion 
and is connected in series with a neutralizing 
condenser to the plates of the 811 As, 

The unit I^ ven,^ easy to drive, their state- 
ment of 50 watts needed to drive it to a full 
KW seems to be a perfectly safe statement if 
a reasonable SWR is present in the output co- 
ax. No exact measmements were made but on 
the lower frequency bands a full gallon was 
possible at something less than 50 watts* This 
is output from your exciter, of course^ and not 
input. An input of around 75 watts seems to 
be a safe minimum figure. Of course if your 
exciter is a little short on power you can drive 
it to something less than a KW. It will operate 
fine at 700 watts, for example, with consider- 
able less than the rated drive for a KW. 

The plate circuit is also normal Good sym- 
metry is practiced around the four 811 A tubes, 
each of which has their small parasitic suppres- 
sor mounted in a symmetrical setup- The tank 
coil is made of good size wire and appears to 
be adequate-especially the 10 meter coil 
which is heavy copper tubing. The band 
switch could be a little heavier. It looks a litde 
small for a KW but again it works fine and in 
view of the low plate voltages used (1400 to 



500 Watts PEP! 




Complete transmitter, including 
heavy duty power supply. 

Features 

Upper and lower sidebands on all ranges 
Power output control 75-500 watts 
Automatic level control (A. L. C.) 

Meter for monitoring plate current and transnnltter 

output 
Provisions for FSK 

Rugged heavy duty cast aluminum chassis 
Modern styling and ertra compact for table top use 
Heavy duty full time blower 
Smooth tuning lOO-f VFO tuning 
500 watts PEP 

Carrier suppression more than 50 db 
Unwanted sJdeband suppression more than 45 db 
Spurious frequencies down more than 45 db 
All Crystals included 

VFO Stability: 50 cps. after one-half hour warmup 
Pi network output. 45-100 Ohms 
Voice control 
Anti-trip circuitry 

Frequency Ranges: 3.5-4.0 mc« 7,0-7.5 mc, 
14^0-14.5 mc, 21.0-21.5 mc. 28.0-23.5 mc. 
28.5-29.0 mCt 29.0-29.5 mc. 

TRI-STATE Eiectronks, Inc. 

2734 Lee Hwy.. Falls Church, Va. 



Send information on the TRl-X-500 SSB Transmitter 
to: 

Name 



A * p * Ik A 



Address . . , 



City 



P ■ ' ■ S P 



«<■ ■■■>» ^ -i * * m wldT^ 



DECEMBER 1962 



Send for literature from our ddvertisers 



61 



Here is the sensational 



Z^i. 



xc- 



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lU U4 JIJ 



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-/«? 



SINGLE SIDEBAND TRANSCEIVER 



The ultimate in TALK-POWER at 
Low Cost 

High Efficiency, One Band Design 

Proven Reliability; Highest Quality 

240 Wafts PEP with 800 Volt Supply 

Mobile, Portable, or Fixed Station 



Models for 20, 40, and 75 Meters 
Now in Production 

$275 

Ask your dealer for odditional 

InformaHon 



wan 



ASK THE HAM WHO OWNS ONE 



ngineering Company 



OCEAN SIDE, 
CALIFORNIA 



1600) this is not reaDy a serious problem » The 
contact spacing is good so no danger of rf 
arcing is present, especially since the peak 
voltages under SSB or CW are not nearly as 
severe as those with a K\V using AM modu- 
lation. 

The standard pi network is used for the out- 
put tank circuit. The ability to match an anten- 
na load of 50 to 75 ohms is advertised and is 
a conserv^ative figure. No loading problem 
should exist with any tolerable SWR in the 
feed co-ax- 

An interesting adjunct to the rf output cir- 
cuit is a small condenser and an rf choke from 
the output line to the ground. The midpoint 
is brought out to a small jack on the rear chas- 
sis apron for use as a feed for the vertical 
deflection plates of your scope— or your vertical 
input amplifier if your scope has good enough 
frequency response. This will allow you to 
watch your scope and get some indication of 
your modulation characteristics* It may not be 
exactly a laborator>^ method for modulation 
monitoring but it does help, 

TTie neutralizing system, as mentioned ear- 
lier, uses a variable condenser from the plates 
of the 811 A lubes, through ihe condenser to 
the coil which is v/ound around the filament 
choke to the ground. The neutraHzing process 



is described in the manual as simply spacing 
the condenser plates a prescribed distance 
apart. This seemed to be a very rough way to 
neutralize and some doubt existed in my mind 
as to the effectiveness of this method. How- 
ever, upon operational test the amplifier is 
perfectly stable with no indieafaon of regenera- 
tion on any frequency. 

The metering system measures the grid cur- 
rent, plate current, relativ^e power output and 
the high voltage. This is indeed fine— these are 
exactly the tilings the operator should know. 
The tendency of modern transmitter manufac- 
tining concerns to simply meter the relative 
power oil I put leaves me cokL For the added 
price of a switch and a few resistors it seems 
that lIjc policy of metering only the output is 
very ill ;id vised, I am of the opinion that tht 
prime reason it is done that way is to conceal 
the fact that a fixed loading circuit does not 
always load your final the way you might wish. 
How many of us have a perfect 1::1 match 
to our antenna? 

The bias supply is taken from a special ten 
volt winding on the filament faansfonncr, half 
wave rectified J filtered and bled through a 5 
ohm and all olmi resistor. The volluge for the 
tube grids is taken from the junction of these 
two resistors and is very stiff, being held very 



62 



73 MAGAZINE 



close to the 4.5 volts desired when under mod- 
ulation. Tlie groLiiided end u£ the bias supply 
is brought out to a terminal board on the rear 
chassis apron where it may be grounded di- 
rectly or placed in series with an external (or 
internal for that matter) voltage of approxi- 
mately 50 or more volts to furnish cutoff l>ias 
for stirndby or "no modulation" conditions. This 
js desirable because some modern exciters gen- 
erate a hash while in tlie "on" status but \\ ith 
no output, such as is the case when no speech 
is present on SSB or the key is "up" on CW. 
This hash may be amplified by the final ampli- 
fier when it is not in a cutoff condition and can 
be very annoying. Odd as it may seem this 
hash, which another commercial rig of mine 
does generate to some extent, did not seem to 
get through the Warrior, even when only the 
normal 4,5 volts were used- In any event the 
addition of some VOX controlled external bias 
can remedy such a condition easily. 

Now J while we are on the subject of bias 
let me digress from the original theme of this 
article for a moment and describe a modifica- 
tion which can be placed in the amplifier to 
furnish this cutoff voltage. Don't turn the page 
as this modification does not require alteiation 
of the original amplifier, but only an addition. 
In other words if you might wish to sell tlie 



unit at some later date you can return it to its 
original condition easily and quickly. 

Fig. 2 shows a bias and switching arrange- 
ment which can be added to the linear to fur* 
nish cutoff bias and/or higher operating bias 
for class C CW operation. The small power 
supply in the uvnt furnishes voltage for the 
cutoff bias and for energizing the control relay 
—providing a low current plate relay is used. 
In case an ae relay is used omit R18 and bring 
out both coil leads as described later in Step 8 
of the construction notes. This bias supply and 
relay will allow several transmitter conditions 
to exist i.e. 1) by connecting a jumper on the 
outside of the chassis from terminal 1 of T to 
the ground terminal on the chassis^ normal 
operation of the amplifier will result regardless 
of the condition (open or closed) of relay Ry 1, 
2) by grounding terminal 2 of T and actuating 
the relay for transmit, cutoff bias is applied for 
standby and the normal voltage of 4,5 volts is 
applied for transmit, 3) by removing jumper 
from T and actuating relay on transmit a cutoff 
bias is established for standby and a high oper- 
ating bias is established for class C CW serv- 
ice, 4) by shorting terminal 1 and 2 of T and 
not actuating the rela\ u condition of no cutoff 
standby bias is established and a high operat- 
ing bias for class C CW is established. These 




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63 




RI9 Oj 
5fL ^ 



czr 

l€mr 

588 




TO HV 
WOICATDR 
UGHT 
ASSOIBLr 



TO EtrtrmAL 

CONTROL 



R6 2 



four bias sitnatious will cover any normal oper- 
ating need and the unit, as can be seen later 
by the installation instructions, can be easilv 
removed at some later date if desired. 

A step by step method of constructing and 
mounting this unit is given here— 



Step 1 



Step 2 



Step 3 



Step 4 
Step 5 



Step 6 



Step 7 



Step 8 



Bend an ahiminum bracket as 
shown in Fig. 3, Mount under the 
nut that holds HV indicator light 
as indicated* 

Build circuit shown in Fig. 2. 
Suggest using printed circuit 
board or a piece of bakelite* 
Mount on bracket of Step 1, 
Remove ground from terminal 2 
o\ terminal striji T and connect 
a 0,1 eeramic capacitor in its 
place, 

Connect center arm of relay to ter- 
minal 1 of terminal strip T. 

Connect normally open contact of 
relay to terminal 2 of T. Keep 
wire for step 4 and 5 clear of 
filter condenser terminal NN2. 

ConncLt primary of power trans- 
former in parallel with HV indi- 
cator light. 

Fabricate juniper w^ire 7Ja inches 
long and connect one end to 
ground lug on rear of chassis. Put 
spade lug on free end of this 
jumper. Use this |umper to ground 
either terminal 1 or 2 of strip T 
as described earlier. 

Bring out free wire from relay 
coil to outside of chassis bv run- 
ning through same grommet as 
115 VAC power wir^.* 



TOP CMASS© 



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REAR 



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TO FIT UftllT ItOUNtlNe 
&OAAD SiZE 



€-3? MACHINE SCREWS CZl 



no 



Step 9 



Step 10 



This 
course this 



Connect 0.1 ceramic capacitor 
from terminal 1 of T to terminal 
2 of terminal strip TA. 
Cut wire 3 inches long and put 
spade lugs on each end. To be 
used to short terminals 1 and 2 
of terminal strip T when amplifier 
is to be used with no standby cut* 
off bias and with high operating 
hi its for class C CW, 
completes the modification. Now of 
small unit can be mounted on a 
separate chassis and wired to the outside of 
terminal board T but it makes a cleaner job 
to do it on the inside. The relay of the unit 
can be connected to the VOX circuits of your 
exciter to be turned on or off with the antenna 
relay, receiver quid in g, etc. If you use an ac 
relay for your antenna changeover switch it 
might be advantageous to use and ac relay in 
the luiit and parallel it with the antenna one. 
Each individual case might be a little different 
Enough for the bias— the power supply is 
normal except for a slight novelty regarding the 
choker and power transformer— both which have 
very lartie cores. This^ perhaps, was to allow 
fewer turns per volt on die windings and allow 
larger wire per given voltage. The choke is a 
swinging type which goes from 5 to 50 lieniys, 
which is quite a swing. Both the power trans- 
former and choke nm at a normal warm tem- 
perature under both SSB and CW operation— 
in fact somewhat cooler than ^vas expected or 
is the case in some other commercial equip- 
ment. One other interesting featine of the 
power supply is that of the switching. The 
transmitter hns two sv\ itches--one to turn on 
the filaments and one to turn on the high volt- 
age. This is to allow the filaments to heat up 
before the high voltage is applied. The interest- 
ing feature is that it does not make any differ- 
ence which su itch you turn on first; the fila- 
ments light first This means diat if you make 
a mistake in turning on the switches you still 
turn on the filaments first- They are marked Fil 

isote * — If an ac relay is used instead of the plate 
type run both leads from the coil out with the 115 vac. 



64 



73 MAGAZINE 



and HV^ of course, for those of us who watch 
what we are doing. 

Doiilile shielding is used— the rf section is in 
its own shielded enclosure which is mounted 
on the chassis and then the cabinet iumis a 
good shield for the overall luiit- 

No special TVI precautions were practiced 
except for the good shielding, A linear running 
a little on the A side of class B is not much of 
a harmonic generator so if your exciter is clean 
your TVI should not be too much of a problem. 
In case you use the higher bias for class C CW 
you might run into more of a TV^I problem but 
usually they can be cleaned up with enough 
effort. Also in the real fringe areas the prol>]eni 
of high power overloading nearby TV receivers 
will present itself but a good high pass filter on 
the receiver antenna input will cure that 

The unit comes with the cabinet painted a 
deep green. The escutcheon on the front panel 
is a matching green with the panel itself a light 
grey w^ith a slight green tinge. It's real pretty— 
if you like green. 

To summarize, it seems to your re\ iewer that 
Heath has done a very commendable job here 
—it's a lot of transmitter for $229, The only 
wish here is that it could have been packaged 
a little smaller. Nothing about it is on tlie 
**skimpy" side, the operation is every tiling a 
KW should be and it really puts out a signal. 
This linear, if it's indicative of the rest of the 
Heath transmitting line, perhaps explains that 
44% noted earlier. 

. , . W6EUM 

Farts List 

Rl ' — part of original unit 

Rl6 — part of original unit 

R16— mC lOK 5 Watt 

R17— IRC 5K 2 Watt 

RIS^IRC 5K 2 Watt 

Rli*— 760 ohm 2o watt IBG typ3 SD 

C25 — Disc ceramic O.l ufd , 

C26 — Disc ceramif! D.l ufd 

Tl — 115 volt ,013 selenium rectifier type 

Relay— See notes 



Letter 



Bear OM : 

Here is n list of my fellow Cubans who are usin^ our 
hobby to spr^d communiat doctriiie from the Isle, COl- 
AF, AH, GN; C02-BG, HY. CF, CJ, CM, CR, CX, DL, 
DT, Eil, FM, FV, GM, HT, IF, IG. IS, IT, JI, JL, KG, 
KI, KY, LD, LM, LT, MF, MN, MR, NF, OF, OM, 
PVp QQ, QS, QV, RO, RQ, RV, SF, ST, TW, VB, VH. 
VJ, VN, VO, WF, WU, XG, XI, XM, XN, ZL, NO: 
C03-AG, BU, JD. MM, NR, PF: C05-CG, CN. ER, FM. 
JA, JP. OF. PV; RB. RP, SA, TZ; C06-AB, ED, FA, 
FB, GF, JC; KF, NV, FF, XZ : C07-AI, CA, CG, HS, 
JM, LM, RQ, RS, RV, SL, SO. LG. FC, XW, JS ; COS- 
AL, BN, BO, CO, CP, CR, DL, DN, ER, ES, HG, HP, 
IC, LA, RM, SD. There are many more which we lack 
proof on so far. 

Rafael M. Estevci C02ZQ 
Kadto Club of Cuba in Exile 
Box 1688, Miami 1, Florida | 



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r«ll '•m you saw it In 73 



65 




Joes Other Worlc 



VS/HEN she came in as usual to open the 
^ curtains to the early-morning sun, she 
knew this was to be no ordinary day. She made 
Joe comfortable, doing automatically for him 
the intimate jobs which had become so much 
part of her routine that it might have been a 
piece of her highly-polished furniture which 
she was putting in order. When he w^as clean 
and tidy, she gave him his breakfast, feeding 
him patiently^ making occasional remarks 
about the weather and the news in the papers. 



Usually he hung onto her every word in 
these moments of intimacy, for she w^as his only 
link with the world outside. But today she 
sensed his lack of attention, that he was think- 
ing of something else. The meal over, she stood 
up. 

**What time do you think they 11 arrive?'* he 
asked. 

Deliberately she pretented puzzlement 
"Who?" 

**Fred and the boys, of course/' 



66 



73 MAGAZINE 



'*0h, sometime. Depends on whether they 
have finished it. Might not be today at all. 
Might be next week." 

She felt an immediate flash of compunction, 
for he suddenly looked like a little boy who 
has been unfairly punished- But Em had never 
been a woman to give in to emotion or what 
she would have called **sloppiness/* "I'll switch 
on the radio for you* There's a nice music 
programme.-^ 

She knew as the room filled with sugar- 
crested waves of Jerome Kern that Joe would 
have preferred a different kind of radio sound 
but it was in her power to decree what he 
should hearj^ at lea^t for this morning. 

Twice in the routine of the hours that fol- 
lowed she had to climb the stairs to answer his 
calL Had his friends phoned yet? 

With bitter triumph she told him twice — no, 
there had been no call yet from the Radio Club. 

Em was a good woman. For thirty years she 
had been a good wife to Joe, keeping immacu- 
late the little house which they had been able 
to buy on account of her penny-pinching. Her 
cooking was famed for miles around, Joe's 
shirts were always spotless, his sweaters and 
socks hand-knitted in intricate designs. All 
their life she had saved money so that now, 
when their only income came from insurances 
and pensions, she was still able to maintain 
the house and their previous careful living 
standard. 

Em even tolerated her husband's little weak- 
nesses, Joe was allowed to smoke except, of 
course, in the parlour, whose velvet drapes and 
hand-embroidered cushions must on no account 
be sullied with the fumes of tobacco • The 
ancient refrigerator always had room for a 
can or two of beer. 

But one thing Em had fought all her life — 
Joe's other world, his hobby, his love for ama- 
teur radio. When they had first married she 
had given little thought to the ominous way he 
would spring to life, so to speak, when con- 
fronted with the load of junk in the attic. Like 
all young brides she had thought a few months 
of marriage would change him sufficiently to 
make him give up all that nonsense. But Joe, 
gentle and mild like so many big men, was 
remarkably obstinate on that point. He was 
hers, body and soul^ except for the time he 
spent upstairs, producing unearthly sounds out 
of the junk and talking incomprehensible Jar- 
gon to people thousands of miles away in whom 
Em had no interest at all. 

Joe gave the major part of his wage-packet 
to his wife, keeping only a small sum for his 
own meagre expenses. But, by depriving him- 
self of cigarettes and beer for nearly three 
years, he saved enough to buy himself a com- 
niunications receiver which was the pride of 
his life. Em hated thi^ interloper worse than 
if it were another woman come to break up 
their marriage. It came to represent for her 
the other world into which Joe escaped from 
her and into which she could never penetrate. 



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DECEMBER 1962 



73 mates a fine Christmas Giff 



67 



However, the junk in the attic acenmulated 
over the years until the receiver was only part 
of a dingy, dusty chaos perpetually over her 
head. Em, whose pride was the gleam and gloss 
of her arrid homej attempted to "clean up*' the 
mess but she met with alarming resistance 
from Joe. Considerate as ever, he would say, 

"Don't you go bothering yourself with the 
attic, dear. The stairs are too much for you. 
I'll look after it/' 

Sometimes, though, when he was away at 
work, she would trudge up the narrow stairs 
into the enemy territory and confront the 
bland, blank face of the detested receiver. She 
would even run her duster over its surface, for, 
hate it as she might, it was against her nature 
to tolerate dust, A more passionate woman 
might have smashed it beyond repair, so that 
it could no longer come between her and her 
husband, but care with money had become part 
of Em's life and she knew that, even second- 
hand, the instrument could realize good cash 
Some time. 

There were days, three or four sometimes, 
when Joe was all hers. He would sit opposite 
her by the stove. Neither of them was par- 
ticularly articulate, but there was some kind of 
commune between them. She would knit, Joe 
read the paper, yawned, scratched himself and 
went early up to bed. Days after, she would 
discover, to her humiliation, that **the bands 
had gone dead," that radio communications the 
world over had briefly come to a stop, for 



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reasons which were beyond her understanding 
and which she did not think it worth her while 
to try to understand- 
Once a week, on Thursday nights^ her re- 
sentment against Joe's hobby rose to hatred 
level. He would kiss her dutifully, tell her not 
to wait up for him and drive off into town in 
the current ten-year-old car to a meeting of 
the Amateur Radio Club. And every Thursday 
night Em would sit brooding over her knitting 
for she knew that, once Joe was with bis 
cronies at the Club, he was no longer hers, no 
longer her man, her child, her property. He 
was beyond her control. 

She always did wait up for him^ greeting him 
sourly on his return ^ yawning ostentatiously. 
But inevitably Joe was so exhilirated by the 
meeting with his friends that he never even 
noticed her meaningful glances at the clock. 
Sometimes Joe would suggest that she come 
with him to a social evening organized by the 
Radio Club for the wives of the radio ama- 
teurs* Most of the other women good-humour- 
edly played along with their husbands in this 
respect, really enjoying the friendly atmos- 
phere of the parties- They accepted their hus- 
bands* hobby for, to most of them, it was part 
of their lives, just as much as wage-earning or 
love-making. Their men^s regular disappear- 
ance into the ether was no worse than the drift 
of other women's husbands into bar or pool- 
room. 

Em could never come to terms with this at- 
titude. She scornfully dismissed the other 
women, either as fools or flibbertigibbets who 
didn^t look after their men properly. A badly- 
ironed shirt, a sock darned with the wrong 
color wool on another man would ensure her 
scorn for his wife. She never forgave the 
merry woman who blithely suggested that she 
forsake her weekly baking session to accom- 
pany her husband on National Field Day- 

^'Reckon she buys all her cakes in the store," 
she muttered. The condemnation was final, ir- 
revocable, 

Joe's friends rarely visited him at home but 
when they did she would be greeted respect- 
fully; then the two of them would firmly climb 
the stairs to the attic and that was the last she 
would see of them for hours. Towards these 
men she maintained an icy silence, barely 
polite* They represented Joe's other world- 
Then, a year ago, things had dramatically 
changed. An accident at work had broken Joe's 
spine. Weeks in hospital had ended with his 
being brought home to spend the rest of his 
life completely helpless, paralyzed from the 
neck down- 

The doctor spoke to her pityingly, admiring 
the fortitude and lack of hysteria with which; 
she bore the blow. 

**He might live for months^ or it might just 
be a matter of weeks. Do all you can to keep 
him comfortable and happy.^' 

He might have spared his pity, Em*s stoic 
expression concealed neither misery nor con- 
trolled shock. It hid a singing triumph- For 



68 



73 MAGAZINE 



hard physical work and extra financial scrimp- 
ing held no fears for her. She could face them 
intrepidly for now she had her husband all to 
herself again. 

Not since the very earliest days of their 
marriage had she been so close to him. She 
was his slave — but he was once more utterly 
hers, at her mercy, the child she had uever 
had. She spent night after night without sleep, 
helping him through the pain and desperation. 
She performed uncomplainingly the most 
menial and offensive tasks. Out of their reduced 
income she managed to prepare luxurious 
dishes to tempt him, revelling in the slowness 
with which he chewed the food, whilst she held 
the next spoonful ready. On her he relied, not 
only for the very pith of his existence, but for 
companionship and entertainment. She read to 
him for hours. She rarely left the house and 
then only for necessities. She never spared her- 
self, caring for his wasting body, putting into 
her scrubbing and bathing and mopping up of 
filth a devoted energy built up of years of frus- 
tration. 

Financial difficulties meant sacrifices, Em 
was scrupulously fair. Her modest diamond 
engagement ring, her prized silver teapot and 
the radio equipment were all sold at the same 
time. Extra cash was needed immediately and 
it seemed logical that each of them should give 
up something valued and loved. 

A winter passed- Em installed her small 
portable broadcast receiver in Joe's room. If 
she heard him the time he tentatively sug- 
gested that it might be possible to pick up part 
of the amateur bands on this instrument, she 
gave no sign. Joe had come back to her from 
his other world. 

Soon, though, a crack appeared in the struc- 
ture Em had built herself* One of Joe's radio 
friends called to see him, Em greeted him with 
the minimum of ceremony and unwillingly led 
him up to see her husband. She stalked out of 
the room, making it quite clear that their talk 
held no interest for her, but she knew with a 
shivering dread that something was going to 
happen. 

The man left and she went back to Joe. 
His eyes were shining. 

"They're going to build me a special receiver, 
Em^one that I can tune myself." 

**What do you mean — tune yourself?'^ she 
said brutally, **you know you can't move a 
muscle!" 

**One of the boys is an engineer. He's rigged 
up something with a lever that I can hold in my 
mouth." 

Em's brief happiness dwindled to nothing in- 
stantly. She carried on with the tasks of 
running the huust* and caring for Joe, but she 
could feel the excitement building up in the 
man. Then came the call from the Club to say 
that the new equipment was complete and 
would it be convenient to bring it over. Em 
stalled for a day or so, making the excuse that 
she was spring-cleaning the room, that Joe 



. 



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Deseend upon the newest amateur equip- 
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a htg ham display and carrjf a huge parts 
sto^k. We carry all makes of ham gear, in- 
cluding Collins. We'll meet just about any 
deal that you can make anywhere and give 
you top notch service to boot. Free home 
trial? Sure! Trades . . . easy payments - - . 
and everything you could possibly expect 
from a group of eager hams selling to hams- 
Call TEmple 1-3171. Come in and bring your 

QSI see Bill WASFCL, Dick WN8ECG and 

Joe W8V5K. 

RSE HAM SHACK 

Division of Radio Supply and Engineering Co. 
93 Selden Avenue, Detroit 1, Michigan 



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DECEMBER 1962 



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MPH 



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USING A TRl-BAND 
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wasn't really well enough for all that excite- 
ment. Finally, though, realising fully well 
what she was doing for herself, she agreed to 
let them come over that Sunday. 

On the Saturday night she had to give Joe 
one of the luminal tablets the doctor had left 
in her keeping, for he w as so excited. 

"Just think, Em," he babbled, "It'll be just 
like old times," 

Her lips tightened but^ when the Club mem- 
bers arrived, she was forced to have four of 
her husband's despised cronie?^ trampling up 
and down the stairs, opening doors and win- 
dows, hammering and shouting and bringing a 
flush excitement to Joe's withered cheeks that 
all her devoted ministrations had never been 
able to arouse* 

Dry-eyed she waited downstairs for the hub- 
bub to quieten. Finally they came down, 

"He*s as happy as a kid, ma'am. Just you go 
nn up and look at him." 

"I'll wait until you've all gone. Then I can 
sweep through my front hall before I go 
w^asting my time with that nonsense/* she said 
ungraciously and did not relax until she heard 
the diminishing roar of their car engine as 
they drove away. 

Stolidly and obstinately and carefully and 
very thoroughly she swept and tidied where 
they had trodden. When everything was once 
more in order she climbed the stairs heavily to 
Joe's room. 

He lay there, still and quiet, with the ghost 
of a smile on his face. The engineer's tuning 
lever, no longer needed, lay on the pillow be- 
side him* 

Em wept the first bitter tears of a life- time 
when she came to realize that Joe had died 
hapT>y and that his other world had won the 
last battle. , , . G3NME 




• 




WITH HEAD MOUNT 



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PLANT 



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Available from your foe a! 
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I ■•■ . « 




F 

* - - 


SUPREME 1 
ELECTRONICS 1 

FRONT &1^A1N STsJ 
UPLAND. PENNA. | 



Letter 



Dear Wa>ne; 

Anent my recent article about chirps in a kit vfo, 1 
learned the reason for the poor performance of the 
dipped Micas. They had cavities in the center where there 
was loose folL Three out of five that I crack sd open were 
faulty. I bought three of another manufacture lueally 
and they all were i^olidly o*k. So, we can't condemn the 
dipped micaSp per se, nor the manufacturer either, he- 
cause a bad !ot could got by easib*. I have written the kit 
maker about it* 

You m&y recall that I wrote an article for AP Features 
about workinif Russian hams. Someone from 73 maited 
me a copy from the White Plains Reporter Dispatch. The 
article still is being run here and there, and I continue 
to Ket fan letters, with the most asked question beinsc 
how to get into ham radio. 1 tell them to buy a copy of 
7S and drool over the ads. But I made the mistake of 
recommending the Drake 2B receiver, and got a prompt 
reply from a lady who wants to know why I recommend 
the Drake, and it isn't even advertised in 73, Tsk, tsk. 
Oh well, I still think the Drake 2B is a Eood receiver, 
but please, get an ad from them. 

The latest query was from a housewife in your area 
who wisihes to buy her husband a ham station for Chfist- 
mas. Lucky scuy I Drake better get that ad in the next 
issut of 73 ! 

Harold Carlj^on K7MSL 





^ 



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utjreme 




SIX METER SS£ JhanAmiJtisUi 

Using The McCoy 32B1 Silver Sentinel Crystal Filter 

75 Watts PEP Input, 6146 Final 

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7360 Balanced Modulator 

Unwanted Side Band Suppression better than 40 db. 

Carrier Suppression better than 50 db. 

Size-Width 12" Height 61/2" Depth ZW Weight 714 lbs. 

Model SSB-6 $ | qq 50 

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For additional informaHon^ write; 




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UPLAND, PA 



DECEMBER 1962 



71 



New Products 




Only a Dollar 



These little call letter signs are about the 
lowest cost signs weVe ever seen. They are 
nicely made and great for mounting on top of 
relay racks, on the operating table, on the back 
shelf of your car, etc. Be proud of your call 
, . , display it. Made by New Products, Box 
481, Grand Haven^ Michigan, 

Centralab Catalog 

C's catalog 200, a 16 pager, lists everything 
Centralab makes in the line of controls, 
switches, ceramic capacitors and packaged cir- 
cuits* It even gives prices. It certainly is well 
worth the three cent postcard required to have 
them mail it to you. Centralab, 900 East Keefe 
Avenue, Milwaukee 1, Wisconsin, Ahem . . . 
mention 73 . . . they're not advertising here 
yet. 




Six Meter SSB 

Six meters, though one of our most active 
bands, has been slow to shift to sideband. One 
reason is obviously the lack of six meter side- 
band equipment which is now being delacked 
by a number of manufacturers. Heath has just 
recently announced a six meter sideband ex- 
citer (io watts) with built in VFO for $189.95 
in the usual complete easy-to-build kit form 
and a companion linear which boosts that to 
125 watts PEP for $99,95, The spex make 
these look like well designed units and they 
should do a lot toward popularizing SSB on 
six meters. Heath will seiid vou full info on 
this pair if you ask. Heath, Benton Harbor, 
Jiigan, 










eciue^ 



9 



st vyur 




ew 




neral Catalosr Mo 






ba Sendi 



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TELEWRITER FREQUENCY 
SHIFT CONVERTER 

$189.00 Rack Mounted-} 14.50 for Caliinal 

The New Model *'K" Telewriter Converter (designed by M. J. *^Dcn^^ Wiggins W4EHU) in^iudBS: I. Linear audio dtstriminatur 
with hlqh Q torolds for fnaximum interfecflnce rejection. 2. Advanced keying tube circuit \u comjiensate fflr distorticn with front panel 
contr©k 3. Sepfarate magnet current supply with milliammeter. 4. Dual nye indicsitor. 5. Cha^s^is tirminals for polar relay bias. S-R 
relay, and loop. 6. Front panel jacks for keyboard and printer. 7* Send-Rec. and Polarity Reversing switclies. For further informatiori 
and reconditioned teletype list, write: Alltronirs Howard Coa.. Box IB, Boston 1. Mass. (Richmond E-0048). 



72 



73 has the widest VHF coverage 



73 MAGAZINE 



BOOKS FOR XMAS 

Your hamshack is no better than your 
reference library. This Christmas buy two 
or three good reference books. 



40— RADIO HAMOBOOK, ISth EDITiON— Orr 

(W6SAi). This is far and away the best amateur radio hand- 
ever printed. Over 800 pages, BARGAIN $7.25 



%%M 



«3-G.E. TRANSISTOR MANUAL 6th EDITION. 



1-EL£CTR0NICS & RADIO £N0INE€RING-T«rmarr. One 
of the most complete text books ever printed. 1078 
poget. Theory, but easy oit th« moth. $15.50 



f-ANTENNAS-Kfous (WSJK). The most complete book 
on antennoi in print, but largely destgn ond theory^ 
complete with math. $12,00 



}|— NEW 16th EDITION of IT'S HERL 
RADIO HANDBOOK. $9.50 



13-REFERENCE DATA FOR RADIO ENOINEERS. Ttiblet, 
Formulas, graphs* You will find this reference book on 
the desk of ofmost ^vmrf electronic engineer in th# 
country. Published by Internalionol Telephone and Tele- 
froph, $6.00 



le— HAM REG I STE ft— Lewis (W3VKD). Thumbnail 

sketches of 10,000 of the active and weM known hams on the 
air today. This is the Who's Who of ham radio. Fascinating 
readfng. Only etfitioti/ Now iinly $2.S0 



tl-VHF HANDBOOX-Johnson (W6QKI]. Types of VHP prop- 
ogotton, VHF c»rcultry« component limitations, antenno de* 
sign and construction, test equipment. Very thorough bciok 
and one that should be in every VNF shack. $2.95 



22— BEAM ANTENNA HANDBOOK— Orr (W6SAI). 
Basics, theory and construction of beams, transmission lines, 
matching deviceSp and test equipment. Almost all ham stations 
n^ed a beam of some sort . . . here is the only soifrce of basic 
info to help you decide what beam to build or buy, how to in- 
stall it, how to tune it. $2.70 



23-NOVICE t TECHNICIAN HANDBOOK - Stoner 
(W6TNS). Sugar coated theory t reeeivefs, transmitters, 
power stipplfes, antennas; simple construction of a 
complete station, converting surplus eciuipment. How to 
get a ham license and build a ttotion. $2.85 



BO-SURPLUS RADIO CONVERSION MANUAL VOLUMf 
NO, 1 u«cond edition). This book gives circuit dio- 
grcms, photos of most equipment, ond rother good ond 
complete conversion instructions for the follow mg: 6C- 
22 1, BC 342, BC-312, 6C-34S, aC-4l2, BC-A45, BC-946B, 
SCR-274N 453 A series receivers conversion to 10 meief 
receivers, SCR-274N 457 A leries tronsmitters (conv^r- 
fion to VFO), SCR-522 £BC 624 ond BC 625 conversion 
lo 2 meters], TBY to 10 and 6 meters, PE 103A, BC- 
t068A/1161A receiver to 2 meters, Surplus tube index, 
«ro5s index of A/N tubes vi. commercial typei^ TV & 
FM channels. St 00 

fit -SURPLUS RADIO CONVERSION MANUAL VOLUME 

NO. IL Original ond conversion circuit diagrams, plus 
photos of most equipments ond full conversion dis* 
cussion of the following: BC-454/ARC-5 receivers to 10 
meters, AN/APS-13 xmtr/rcvr to 420 mc, BC-457/ARC^5 
xmtrs to 10 meters. Selenium rectifier power units, ARC-3 
power and to include TO meters, Colt data*simplified 
VHF, GO-9/TBW, BC-357, TA-12fl, Atsl/ART-13 to a« 
winding charts, AVT-112A, AM'26/AIC, LM frequency 
meter^ rotoforSir power chart, ARB dfogfom. S9.W 

82-SURPLUS RADIO CONVERSION MANUAL VOLUME 
f^Q^ Ill^Originol and conversion diagrams, plus some 
photo of these: 701 A, AN/APN-1, AN/CRC-7, AN/URC-4, 
C8Y-29V25, 50083, 50141, 52208, 52232, 52302 09, FT- 
ARA, BC-442, 453 455, 45d 459, BC-69d, 950, 1066, 1253, 
241 A for xial filter, MBF (COL-43065), MD.7/ARC5, 
R.9/APN-4, R23 R 2S/ARC-5, RAT, RAV, RM52 (53), 
Rt-19MRC-4, SCR274N, SCR 522, T-15'ARC-5 to T* 
23/ARC-3, IM, ART 13, BC 312, 342, 348, 191, 375. 
Schematics of APT-5, ASB-5, BC^59, 1335A, ARR-2, 
APAIO, APT-2. $3*00 

731-HAM-TV-WcT>KYQ, This Is the only boofc available 
on this fascinating branch of ham radio. Describes com- 
plete ham TV station thot costs under $50, Very 
simple, $3,00 

738-SlMPLIFIED MATH FOR THE HAMSHACIC BY KSIR- 

Unbelievobly simple explanation of Ohm's Law, squares, 
roots, powers, L/C, logs ond the slide rule. No student 
should be without thts booklet* SOc 

739-COILS by KSBYN— Wonderfully wTitten and illus- 
trated through discussion of coils, their resistance, re- 
actance, impedance, Q, and distributed capacitance, 50c 



t4-iETTER SHORT WAVE RECEPTION-Orf (W6SAn, 
How to buy a receiver, how to tune it, align it; build* 
ing accessories; better antennas; QSL'i^ mops, ourora 
I ones, CW reception, SSB reception, etc. Handbook for 
short wove liitenert and radio amateurs. S2*SS 



26-5-9 SIGNALS-Orr (W6SAI). A manual of practical de- 
tolled data covering design and construction of highly ef- 
ficient, inexpensive antennas for the amateur bands that 
you can build yourself. $1.00 



27-QUAD ANTENNAS-Orr (W6SAI}, Theory, design, eoti- 
struction, and operation of cubical quods. Build -it your- 
self info. Feed systems, tuning, $2-BS 



Order Form 

Circle fho book mimbors you v/lsh to ordsr 
Please include cosh, check, money order • • , 
or somethmg we c^n deposit in the bank. 



Name 



t # ' « « 



Call 



Address 



* * • t 



%g#'i fy>..««*»« ■#••• ■• w I o I w «•*••■•• 



SB-TELEVISION INTERFERENCE-Rand (WIDBM). This It 
the authoritotive book on the sub|ect of getting TV I out 
of your rigi and the neighbor! sett. S1.7f 



at-RCA RADIOTRON DESIGNERS HANDBOOK-1500 
pages of design notes on every possible type of circuit* 
Fabulous. Every design engineer needs this one. $7*50 



RADIO BOOKSHOP 

1379 East 15th Street, Broolclyn 30. N. 

(N.Y.C. ada 3% fax) 

Add 8^2% ^^ Canadian Checks 



Y. 



DECEMBER 1962 



73 



Transistorized Squelch 



HERE IS A SIMPLE little circuit that 
will open the eyes of all mobile men. It is 
simple, cheap and you can build it in about 
an hour's time. The few parts required can be 
squeezed inside most any radio- Here is how 
it works, 

^^'ith no signal being received, the negative 
AVC voltage present at the base of the tran- 
sistor is low. The transistor h tlierefore "Cut- 
Off/' and there is no current flow through the 
470K collector resistor. The voltage at the 
collector is now a negative six volts. This nega- 
tive six volts is applied directly to the grid of 
the 1st Audio tube, through a 220K resistor, 
driving tliis tube to cut-off, thus silencing the 
receiver. When a signal is received, and the 
negative AVC voltage is applied to the base 
of the transistor, the transistor conducts^ thus 
pulling current through the 470K collector re- 
sistor. The voltage at the collector drops al- 
most to zero, thus removing the negative vol- 
tage from the grid of the 1st Audio stage, 
allowing the receiver to operate in a normal 



maiuien 



AC 



mo 



PUP 
2NI574 

-^^AA^ W — f ■ ! 



e 



® 



DflvidCabanissWITUW 



The setting of the 50K potentiometer de- 
termines the level of AVC voltage necessary 
to operate the squelch. The 1N34 diode pre- 
vents the negative voltage from the batteiy 
from being appUed to the AVC line. (When 
wiring this circuit, be sure to note tlie polarity 
of the diode.) 

The component values shown on the circuit 
diagram were optimum for the particular re- 
ceiver in which the author's squelch was in- 
stalled. Wlien this circuit is installed in other 
receivers, it may be necessary to lower the 
value of the collector resistor (470K) or in- 
crease the value of the input resistor (18K) 
(or both) due to the various levels of AVC 
voltages available from different receivers. Al- 
most any inexpensive PNP type transistor can 
be used. 

The author has spent many agonizing hours 
''trying'' to build various types of squelch (an:! 
ANL) circuits using conventional electron 
tubes; after building this gimmick, Vm con- 
vinced that transistors are "Here to Stav-" 

. , , WITUW 






2201C,I/ZW 



TO Fr(TST 
AP GRID 



J^470K 
t/2 W 




BOTTOM VJCW 



r 
e 
c 



TM 




w ri ._ ^>^Lr-*-+«' ~ »- 



Wfs-WdM-^tJI yfe'- 



I ■■S-JIIH< ^«_ W: Jv^A -:"' 



The Waters 
Notch Filter 



Tom McCann K2CM 
146 Hillcresf Avenue. 
Morristown, New Jersey 



m 



TIMELY RELIEF is at long last af^ 
forded owners of KM'M-2 transceivers and 
75S-1 receivers who have frustrated when a 
big, hot heterod)ne parked in their passband 
and swamped out the wanted signal. Waters 
Manufacturing has an inboard notch filter for 
these luxurious ligs at less than three percent 
of the bucks you put into the transceiver and 
an hour or less of installation time. 



Coded 337-S-l and 337-M^2, either model 
at $33,95 net, these new units die fin-nished 
assembled, complete with the knobs and 
escutcliion plates matching tlie Collins panel. 
When the unit is mount ed^ it looks, performs 
and handles like Mr, Collins himself furnished 
it with the equipment in the first place. 

No drilling is necessary to mount these units 
or the controls, except for one hole in the 



74 



73 MAGAZINE 



Pacific Plantronics now offers to the Amateur Radio Operator.. 




It is a Miniature Boom-I\1icrophone Headset Combination 

It is the smallest such device in the world , . . 2/3 oz- 

It has flown the fastest - . . 17,560 mph. (see below*) 

It has flown the highest, .-..., 176 mi. (see below*) 

(t is the MOST in sophisticated communications devices in the world for the money. 



MS-20. . , .$32,50 Microphone only 
MS-30. . . .$47.00 Microphone & Receiver 



Price includes 1 oz. headband for 
optional wearing 

A Development of: 

• Pacific Plantronics MS-41 (standard in the 
Project MA-8 Mercury Astronauts' space 



d 



Pacific Plantronics MS-50 (Soon to be 
standard on United Air Lines jet fleet) 

Dealer Inquiries Invited 

{Pat, Appl. for) 



O^ PACIFIC PLANTRONICS, INC. 

P. O. Box 604 • Santa Cruz, Calif. • GA 6-5858 



Voice Engineered Freq. Response: 

Nominal 280 — 4200 cps ± 6 db 

• 3,000 ilimpedence, microphone 

600 ^ impedence, receiver 

• 49 dbm at normal speech level 



r 
I 

I 
I 

I 



^B> PACIFIC PLANTRONtCS, INC. 

P.O. Box 604 -Santa Cruz, Calif. * GA 6*5858 

Gentlemen: Please send me Air Mail pre- 
paid 

. ^MS-30 Headsets @ $47.00 

MS-20 Microphones . . .@ $32.50 



j I am enclosing my check for. 

I " 
I 



in payment (please add 4% sates tax to 
California orders) 



1 Name. 

I 

i 

I City. 



Address. 



State 



I 



DECEMBER 1962 



75 



KWM-2 panel wlucli is thin aluminum at the 
point selected and is an easy operation with 
the template provided. Installation and con- 
necting instruct ions are furnished in the form 
of clearly stated numbered items of procedure. 
For those wlio are nerxous about "lifting up 
the hood" of these pretty boxes, we miderstand 
the Collins service stations will gladly do tlie 
installation job for a nominal charge, 

Q-muItipliers and their equivalent have been 
available to us now for several years. They 
can be tempemiental things* Aly own experi- 
ence with them covers varieties all the way 
from home-spun, through Idts to various com- 
mercially availa])le units. Some hav^e been un- 
stable, some have a good depth of notch but 
take out tou much of tlie wanted signal, others 
have required a critical adjustment of balance 
to attain satisfactory suppression without im- 
pairment of the wanted signal. So my curiosity 
was more than a little aroused as to how^ 
Waters achieved a remarkably narrow notch 




uc 



h 



TV BULLETIN 
$T.OO per year 

The first issue of the TV Bulletin is now ready 
for mailing. This is a bi-monthly bulletin designed 
to keep all fellows interested in Ham -TV up to 
date on technical improvements in Ham-TV gear 
and on all activities. In the first issue of the 
Btilletia there i§ a list of aU known hams who 
are reported to be getting on the air on TV, The 
Bulletin is edited by Mel Shadbolt, WjztKYQ, 
the author of the popular HAM-TV book. Get in 
on this from the first issue and have a complete 
set of information at your fingertips. The pres- 
ent plans call for six issues of the Bulletin per 
year* with at least 12 pages per issue, 

BOUND VOLUME $15 

If you've missed the early issu^ of 73 this is 
a fine way to rectify that oversight This book 
will keep you up to all hours of the night for 
weeks trying to catch up with the hundreds of 
articles we have published and the ridiculous 
editorials. This volume contains the first 15 issues 
of 73, from #1 in October I960 to December 
196L Bright RED, stamped in gold. 

YEARLY BINDERS 
$3.00 

These are also BRIGHT RED and stamped In 
Gold! Specify what year ytm are collecting: 
I96€-l, 1962, or 1963, Preserve thf^se copies for 
prosperity, 

73 Peterborough, N, H, 







which is effectively deep (40 db) and is at 
onc*e so stable and easy to adjust to the in- 
terfering signal. 

Its qtiite apparent that Waters engineers 
have shrewdly taken full advantage of the 
specialized characteristics of the CoUins equip- 
ment for which their unit is specifically in- 
tended* They use a bridge T network with a 
carefully designed high Q shunt-tuned coil as 
the series element, Tliis network is in the plate 
circuit of a 12AX7 tube which serves as a 
cathode follower coupled to a regenerative 
amphfier* This combination is connected in 
series with the if amplifier of the set at the low 
It \e] end. The regenerative amplifier is ad- 
justed below the point of oscillation where the 
plate circuit lias a very high Q and introduces 
a high loss to a very narrow band of fre- 
qucjicies. The front panel tuning control moves 
the notch from well outside one edge of the 
passband, through the passband to well out 
tlie other side. Dealing vvitJi tlie uniformly 
excellent shape factor of the mechanical filter 
and a fixed piissband of 2.1 kc, Waters adopted 
a hming range of 455 — 2.5 ke, so when not 
required, the rejection notch is simply dropped 
over the steep slope of the mechanical filter 
by timing it to either extreme. The insertion 
loss with the tuning control in either extreme 
position is less than a quarter db. 

The Waters 337 unit provides amazingly 
satisfying iclief both from heterodynes appear- 
ing in the receiver passband and from ^'monkey 
chatter" slopping into the passband from sig- 
nals just above or just below^ the selected 
chaimel. Sophisticated operators seldom oper- 
ate their receivers at miLximum rf gain unless 
they are ''digging for the weak ones." They 
run their gain at tlie point where the incom- 
ing signal at its lowest fading level just ticks 
the S-meten Operated in this mamier, the 
Q-notch will siipress practically any hetertidvne 
except from the K\\^ next door, Whde the 
Q-notch is inherently a very narrow band de- 
vice, smart operators are finding them remark- 



76 



73 has th© mosf surpfus ads 



73 MAGAZINE 




Kl 






A PRE-ENGINEERED HAM EQUIPMENT 
CENTER WITH BUILT-IN POWER & 
\J\J 6 COMMUNICATION FACILITIES 

Bring the ham center up out of the cellar — let the whole family share in the 
fafciimting world opened up by global communications. The handsome styling of this 

functional unit fits well in any dteor — neatly organiies equipment and coblei, 

OUTSTANDING FEATURES— 

1. UNIQUE power channel safely encloses all inter- 
connectingf wiring, relays, etc. Eliminates "rat's- 
neat" behind equipment. Room for built-in power 
supply p filter network, etc- 

2, CONVENIENT "big switch" with indicatini; fuse- 
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HAM-TV 

This is the only book ever prin+ed on the subject. It covers 
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INDEX TO SURPLUS 

W4WKM took the time to go through every radio 
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conversion of surplus radio equipment, hie lists not 
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conversion, $1.50 



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rules; etc. 50^ 

73, Peterborough, N. H. 



78 



73 MAGAZINE 



ably effective in suppressing 'monkey chatter" 
by setting the notch just inside the high or low 
edge of the passbaiid* This has the effect of 
narrowing the receiver passband, which under 
conditions frequently encountered, can make 
tihe difference between ^'getting the message 
tlirough" or having to give the whole thing up 
in disgust* 

A Q^notch Model 340-PT ($44,95 net) has 
recently been made available for transceivers 
associated with a separate PTO for separate 
receive and transmit frequency control of tlie 
KWM-2. No Q -notch is presently available 
for the KWM-2A equipment equipped with 
extra crystals for Mars and other frequencies 
as Collins has used the refection tuning control 
mounting hole in these models, 

You'll like this Waters Q-notch. It performs 
beautifully and looks good. It certainly wiU 
enhance the value of your current equipment, 

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Complete set: $5.00 

73 Peterborough, N. H. 



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would give you one of these if he could make 'em, but it takes huge machines 
to crank these precision moulded gems out. Give one to the XYL for Xmas, 
be a Dandy Sandy, Give one to the J r op so he can put it up on your shack 
walk But when you give it you don't have to let on about the free one 
year subscription to 73 (or extension) that we're sending. Now, about these 
maps . . . they're 28^" x 18^" and the mountains stick right up at you, all 
in the right places. This is not one of those cheap crumby maps either, it is an 
expensive uncrumby one with eight colors, all diff extent. Send, 

Sir: Please include at no charge with this order a 

Enclosed is $9.95. Please send me one of your 3-D one year (new) (renew) subscription to 73 

maps immediately. U.S. — World — starting with the issue. 

Name Call (Two years with two maps.) 

Address Send order to; 73 Magazine, Peterborough, New 

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DECEMBER 1962 



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73 MAGAZINE 




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BACK ISSUES 




73 




AMi^TEUH RADIO 









We have a diminishing stock of all back issues 
except January 1961, We are willing to part with 
this stock for only 50# each. How about that! 

73 Pe+erboroughi N* H* 



DECEMBER 1962 



81 



(W2NSD from page 4) 

W6RNC is still turning out Junk mail from liis 
hot little mimeograph and the pity of it is that 
every now and then he finds a sucker to re- 
print some of his garbage in a ham chib bulle- 
tin. 

Look fellows, if the editor of your club paper 
lives in such a vacnum that he doesn't know 
what tiie ACARN is really all about then 
please give him the word* This supposedly ex- 
treme rightist group (one man) is using the 
time tested com mm list technique of waving 
the flag and calling everyone who objects to 
him a communist or a pinko. I don't know^ if 
this joker is a communist^ but he certainly is 
following their line. 

The basic ''idea" espoused by \V6RXC is 
that we should use ham radio to broadcast 
U, S, nationalism, including twice daily play- 
ing of the NATIONAL ANTHEM by every 
American station. This is supposed to counter 
the expansion of communfsm. What fantastic 
stupidity! The FCC and every responsible 
thinking amateur is on tliis guys neck. He will 
shut up when everyone ignores him. Explain 
to yoiu' club paper editors. 

One of the latest blasts was at the Inter- 
national Ham Hop Club, which RNC called 
pinko. Balderdash. First of all the IHHC has 
virtually no organization other than a couple 
of f cllow^s who coordinate the desires of fellows 
to put up visiting hams with the desires of 
tx'aveling hams to visit hams in other coun- 
tries. The only political piece that they have 
ever put out in tlicir little bulletin was one 
which I suspect makes RNC furious. , , . It 
was a list of the popular complaints about tlie 
United States whicli you might face during a 
trip through Europe and good logical explana- 
tions to answer these questions. The paper was 
very well done and gave w^ell thought out 
answers to all sorts of anti-U. S, gripes. This 
is the sort of thing which obviously would 
enrage dedicated communists. I considered 
printing the piece in 73, but decided not to 
on the basis that few of ovir readers would 
be able to use it. I have met many of the 
questions it answered during my trips to Eu- 
rope^ but haven't run into tliem over the air. 

Watch for my name on the top of tlie pinko 
or red list from RXC (ACARN) next month 
. 111! That's the only way he can fight facts. 



* * 



Reciprocation 

Wellj Congress adjounied without consider- 
ing our Reciprocation Bill, thus limboing it 
with all other unen acted proposed legislation. 
Wliat happened? Apparently somew^here along 



the line some government agency biought up 
the dread word "security" and that was tliat* 
This means that important foreign amateurs 
visitinc]^ this country can not, even if the FCC 
considtrs it a matter of great importancej 
allow them to operate an amateur station in 
this country. 

When you consider the number of Americans 
that have been permitted to operate in foreign 
countries you can perhaps understand why tliis 
is so galling to foreign amateurs. Unfortunate* 
ly for us the same amateurs \\ ho are efiected 
by this ruling also are the ones who swing 
considerable weight in dieir own countries. 
Outside of an occasional grumble when you 
work or visit a DX operator you probably won't 
notice much difference in tilings until the 
cards are on the table at the next international 
radio conference at Geneva in about three 
years. At that time we w^iU be w^anting the 
entire world to support the largely American 
hobby of ham radio by sacrificing the frequen- 
cies that they feel they badly need for com- 
mercial and government purposes so we can 
continue to have a good time* We almost got 
our ears pinned back in 1959, Our "friends" 
were after our scalp and guess who pulled our 
chestnuts out of the fire , , , the U.S,S.RJ Is it 
likely to liappen again? No. 

Why no reciprocation legislation? Apathy, 
It is un fori una Lc that we have fellows that 
are quite dedicated to undermining our hobby 
and no one, apparently, dedicated to its sur- 
vival. 

RM^34I 

A petition was sent in to the FCC request- 
ing the expansion of the twenty meter phone 
band down to 14,150 kc. After only a short 
deliberation this petition was rejected. We 
have much to learn from this action. In this 
case there were many factors which made 
consideration of the actual request almost im- 
possible* The petition itself was wandering 
and \ague. It went on and on witli non -per- 
tinent rambling, complete w^ith a bitter attack 
on the A.RJl.L, Pub heat ion of the petition 
as submitted would have put the FCC in the 
position of publisliing a long harangue agamst 
t!ie A.R.R.L* Now, no matter what the feelings 
of the men at the FCC^ they certainly can't do 
that. 

The petitioner proceeded to put undue 
pressure on the FCC for action on his petition^ 
rather than waiting for them to take action on 
their own. He circulated his petition and got 
it printed in st \ mil ham club bulletins whose 
editors didn't mind the anti-ARRL nature of 
the text. lie pressured on the air, wrote letters^ 



82 



73 MAGAZINE 



etc. If only we had liad someone as dedicated 
working for the reciprocal licensing bill! 

The ARRL, according to the November is- 
sue, page 61, is looking into expulsion of the 
petitioner from the ARRL. 

The FCC had several other problems with 
this same chap, and these might have influ- 
enced tliem negatively. There were numerous 
reports of TVI in which he was uncooperative, 
complaints of overpower, complamts of ex- 
cessively broad and splattering signal, com- 
plaints of malicious interference, and several 
other serious prol)lems much too lengtliy to 
cover here. Quite a few* people seemed to sus- 
pect that tlie petition was submitted more for 
personal reasons than any interest in the hobby* 

If tliere are adequate reasons for the twenty 
meter phone band being extended down 50 kc 
more, then I am sure that the FCC would wel- 
come a reasonable petition reqiK sting same. 



How Long Has This Been Going On? 

A letter came the other day, sent to my 
Call Book address in New York, extolling the 
virtues ol Rockefeller, complete with illustrated 
brochure, sent bv four New York hams, in- 
eluding one lesser A.R^R.L. oflScial. Since these 
fellows were, as I recall, the sarne chaps who 
confeiTcd with one of Rockefeller's aides in 
die matter of getting the New York call letter 
Kcense plates, it seems rather obvious that 
some sort of bargain was struck. That's the 
way politics works, I suppose. Are the New 
York lads in there with a new first, using ham 
radio for political ends, or have I just been 
out of touch? 

Several rehgions have been using the ham 
bands for ''discussions*' with the idea of gather- 
ing more adherents. The anti-comniunists are 
going great guns with their nets (they say they 
are anti-communists^ but everything they print 
sounds exactl)^ as if it came direcdy over Radio 
Moscow), perhaps we will soon see Demo- 
cratic nets. Republican nets, and Vegetarian 
nets, ril be watching the Operating News col- 
umn in QST for further developments. Any- 
body for a Porsche Net? Or how about a Ham 
Radio Net for the few of us who are interested 
in that? 

National NCX-3 

Our proximity to Boston and the National 
Company plus the understandable pride in a 
startling new product brought .Mike Ferber, 
WIGKX, the Equipment Sales Manager, up 
here on a Sunday to show off the new National 
Tri-Band NCX-3 Transceiver. 

We looked it over, talked it over and then 
hooked it up and bied it out. I like trans- 



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COLUMBIA 



ElECrRONICS 



4JC5 WES! PICO filVD, lOS ANLlliS n. CALIF 



DECEMBER 1962 



83 



eeivers. We had the thing on the air and in a 
QSO inside of one minute. All we did was 
connect the power supply /speaker unit to the 
transceiver, plug it in the wall, screw on the 
antenna, plug in the mike and we were on tlie 
air. 

There wasn't any point in trying to set vip 
a big lab test at this time since we were 
interested in getting reports from some critical 
operators and getting the feel of the trans- 
ceiver. The reports on both 20 and 75 were 
completely complimentary . . . we were put- 
ting out a clean, strong signal and voice qual- 
ity was fine. We tuned 40, but didn't try to 
make a contact there. The receiver tuned nice- 
ly, having plenty of band spread and a solid 
feel to the nice large knob. At $369 for a 
three band transceiver I suspect that National 
will sell an awful lot of these. 

Judging from the large number of trans- 
ceivers tliat will be on tlie market by next 
spring, the manufacturers are intent on satisfy- 
ing the pent up demand for sideband trans- 
ceivers for mobile and home use. The day may 
not be far away when most of us are using 
transceivers instead of the old receiver-trans- 
mitter combinations. 

What About CD? 

Though the odds are overwhelmingly 
against any possibility of war, the recent 
Cuban affair got a lot of fellows tliinking about 
CD and the part that ham radio would play 
should something happen. It is always better 
to consider alternatives before an emergency 
rather than wait mitil the emergency presents 
itself and sound consideration is impossible 
with temporary expediency becoming the rule. 

At the outbreak of the last war we were 
promptly thrown off the air. This freed equip- 
ment and frequencies for military use. (My 
old SX-24 went to Brasil with the Rubber 
Development Commission^ a government out- 
fit that spent millions of dollars to try to grow 
rubber in Brasil and never sent back a rubber 
band. The 2)2 meter band was turned over to 
tlie SD radar, a unit that was planned as an 
anti-aircraft radar, but which turned out to be 
a wonderful homing beacon for aircraft look- 
ing for submarines). 

It seems likely that in the event of another 
war our government, if they have time for 
such an action, would again institute a com- 
plete ham radio blackout. Of course, if the 
next war takes the course that we tliiiik 
probable, we may find our telephone, telegraph 
and power systems all disintegrated . . . which 
would essentially leave us governmentless. 
Without communications you don't have any 



government. Our country could conceivably 
be held together by amateur radio. What else 
have we got? 

Pursuing this thought a bit, it seems to me 
that there should be some encouragement 
above and beyond Field Day for the establish- 
ment of independent power for our stations. It 
might also be a good idea to acquaint ama- 
teurs with cyphering techniques. There are 
several fairly simple but e|Eective systems 
which we could experiment with were it not 
for the FCC regulations prohibiting this. Per- 
haps it is time for someone to petition the 
FCC to permit en cyphered transmissions on, 
say, two meters, where our Technicians could 
get a chance to play around. 

Club Notes 

A letter from K7RPT of North Bend, Ore- 
gon, suggests that we follow up tlie article on 

page 50 of the Octo^ber issue of 73 wherein it 
is suggested that clubs have a local net by the 
establishment of a sort of national net fre- 
quency, I have been sort of tinkering with this 
idea myself. RPT suggests diat we standai'dize 
on 29.2 mc since this is fourth harmonic of the 
popular surplus 7300 kc crystals, iVe checked 
with a couple of crystal manufacturers and find 
that we can get a good supply of crystals all 
on the same channel quite reasonably. With a 
little encouragement we might see what we 
could do about this* 

It seemed to me that it mieht be nice to 
establish channels on all amateur bands for 
members of the Institute of Amateur Radio to 
congregate , . , sort of calling frequencies. The 
number 73 somehow seems to wander through 
the suggested frequencies. Like 145,73 mc, 
50,73 mc, 21.373 mc, 14,273 mc, 7173, 3973, 
etc. And thoughts on this? 

ARC-2 

Several fellows have wiltten in to tell us 
how much fun they are getting from their 
ARC-2's which they converted per our article 
in the October 1962 issue. They seem to be 
available from Columbia, JJ Glass, Fair and 
Bill Slep. The parts list for Fig. 3 was not 
complete and the following might be helpful. 
Tl-117vac/24v 4A Stancor P-6378 or equal 
CR-1-CR4 silicon diode 400v PIV 500 made 
Sarkes-Tarzian M-500 or equal. CR"5*CR-8 
silicon diode 50v PIV, 3A dc if autotune not 
desired or 6A dc if desired, available from 
TAB for 50fl^ 3 A or $1.50 for the 6A. J401 is 
ex-dynamotor connector and PlOl is main pow- 
er connector. We are working on a booklet 
on the ARC -2 which should be available in 
a few weeks. It will sell for $1. 



84 



73 MAGAZINE 



Saddle Stitching 

Some of the letters ask when we are going 
to change from a saddle stitch binding to the 
flat back binding med by CQ and QST. Well, 
I really hadn't planned on changing. We could 
save quite a bit each month if we went to this 
less expensive binding, but it seemed to me 
that saddle stitching was better since it allo\N s 
you to lay the magazine flat for reading and 
for building from the articles. Did you e\ei 
try to flatten out a copy of QST and lay it on 
the workbench? There are se\^eral of the larger 
magazines that use saddle stitching, including 
the New Yorker and Playboy, Unless you have 
some reason for wanting us to change well 
stick wqth saddle stitching, 

W</>RQF Improvement 

Tlie schematic on page 90 of the March '62 
issue of 73 was pretty good, but not perfect* 
RQF points out that the one meg resistor in 
the plate of V2 should be moved to the right 
one connection so the NE-51 won*t have plus 
300v on it. If you are going to do any RTTY 
converter building you had better go back 
and mark that diagram right now. 




Prize Winners 

The Rock Creek Amateur Radio Association 
(Washington, D. C), W3RE President, has 
taken a long step fonvard in this day and age 
of kit building and 100^ commercial gear sta- 
tions. They have instituted a yearly set of 
awards for the best lionie built equipment by 
beginners licensed less than one year. The 
winners tliis year were Donald Campbell 
KX3RAZ, Larrv Rubin KN3STB and James 
Henkel KN3TIV, all of Maryland. Left to right 
in the pliotugraph are K\3RAZ, Robbie 
W3RE, KN3TIV, Joe W3PIH (contest chair- 
man) and KN3STB. 



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08 VAC 3« 2 

0-10 VAC 2' 2 
0450 VAC 3 
0-250 VAC 4«/2 
2D00-20O VDC 
0-300 VOC W2 
0-50 M MA 2! 



R.-,. 

" R^ 

R 



/ fi 



R„, 



0.200 MMA 3^2" S- 
0.500 MMA y/2" R- 



.93.95 

, 3.^ 

- 3.95 

. 4.95 

- 3.95 
_ 6.95 

, 4.95 

. 4,95 



I-S2A. Ind.. new_^ $3,&5 

I-81A, Ind,, ntw_^ 2.95 

SO^C Thermostat ___ 2.95 
Oa MADC IVz* R„_ 3-95 

0-15 MA 2i/z" R „ 3.95 

MA 2*/i" R,__ 3.95 

MA 2»/2" R 3.95 

MA 2* 2" R._— 3.95 

3;95 



0-20 
0-30 

0-35 
0100 



MA 21 



R ^_ 



RADIO ZONE MAP 

GET YOUR FREE COPY. . . 



OF IHE UNtnO STATl! 




REQUEST IT WITH YOUR NEXT 
ORDER OR INQUIRY TO:- 

Udd Elhtronks 

III No. 41 ST., OMAHA 31. NE BR. 



DECEMBER 1962 



8S 



R 





eceiver Modifications 



James M. Sfueber WSUOZ-AFSUOZ 
8410 Flower Place N.E. 
Albuquerque, N, M* 



THE R-45/ARR-7 receiver is a con- 
tinuous tuning type covering the range of ,55 
me thru 42 mc* It is a single conversion super-- 
hetrodyne circuit, with two tuned rt stages 
and one untuned preselector rf stage. The 
design is a modification of the well known 
Hallicrafters SX-28 receiver. The particular 
modified receiver was built under a Signal 
Corps contiact by the Belmont Radio Corp. 

Inclusion of the described changes will pro- 
vide the user with a good communications 
receiver, overcoming the major disadvantage in 
the original design, which is the lack of band- 
spread tuning, 

A schematic of tlie receiver and a coil lavout 

w- 

for alignment purposes is included for those 
who may require them. 

Appreciation is extended to Mr, Amos Peters, 
AF5LIIX, for suppl)lng the receiver through 
the MARS Central Technical Net, thereby 
making these modifications possible. 

The changes described consist of the follow- 
ing: 






COM 



m tcT 



O 

O 

II* ti 

o 

ii-n 

O 



o 
o 

O 

tl-4t 

o 



—^ — 

o 
o 
o 

o 




Oo 

^^-^ PVkC 

Oo 



Cl-4t 

Oo 



FPOifT 



1. 

2. 

3, 
4. 
5. 

6. 



L 



2, 



3. 



4 



5. 



a 



7. 



8. 



Addition of bandspread tuning and dial 

Addition of necessary wiring to provide ac 

power supply operation 

Addition of Send-Rcv, Switch 

Improvement of "S" meter circuit 

Audio amph*fier modification for speaker 

connection 

Low impedance antenna input stage 

Bandspread Tuning and Modification 

for ac Power 



Remove the screws holding the cover plate 
which houses the tuning clial motor re- 
versing switch and stop mechanism. Dis- 
card* 

Cut the wires from the motor reversing 
switch SW3 and remove the switch. 
Remove the stop mechanism from the 
main tuning dial shaft and discard. 
Remove all the knobs from the receiver 
and the screws from the power connector 
so the front panel may be taken off. 
Remove the main tuning dial by loosening 
the alien-head screws^ 
Remove the cover from the cast aluminum 
housing containing the 28V dc motor and 
associated parts. 

Remove the filter, motor and misc. parts 
from inside the box. 

Remove the fiber gear from the vertical 
shaft. 

This may be sealed witli paint and may be 
di£BcuIt to loosen, but with the proper size 
alien wrench and solvent to loosen the paint, 
it will come loose. 



86 



73 MAGAZINE 



Meshna jr Astoundments 



TELETYPE PRINTER PAPER, rolls, 8% 

inch wide . • • * , 2/Sl.OI) 

TELETYPE PERFORATING PAPER, case 40 

ARC-S TRANSMITTER, 80 meters, 3-4 mc. 8.50 

MD-7 MODI LATOR, brand new . 8,50 

IBM MEMORY PLANE, 8JJO0 bit storage,.,. 15-00 
COAX SWITCH, Thompmm. new, 115 volt 

AC 60 cycle , _ 12,50 

SOLAR CELL BANK KIT. 5 cells, with 

instructions ♦ , , , , L50 

OSCrLLATOR TRANSISTORS, same as 

PHILCO SB-100 2/3.00 

RESISTOR ASSORTMENT, marked % watt, 

Ceil l/UII k\f\J »«*BPiaiK*i.B*Cfi«a*. *.*«**«.«•« X»Ov 

28 VOLT 4 AMP DC SUPPLY, unused sur- 
plus, input 1 15 V, 60 cycle , * * . 12.50 



MICROAMETER, dual 150 microamp move- 
ment, used in teletype operation as signal 

meter w/instruc* «**•#« ^ ,,,.*.*..... , 

COLLIN- \RC-12 TRANSCEIVER 22Cl"40l> mc 

1,000. nofi KC CRYSTAL, HC-6 holder 

220 MC: rJTPOLE ANT, BRAND NEW 

NICAD liiHY 1,2 volt, 4 amp hour .-,_ 

DISC CERAMIC COND. bag of approx. 100 



$L95 
22.50 
2.00 
3.00 
1.95 
1.00 



TD-2 



• ■•■'■■■ 






Q 



ic H;?a:«« Sl- 
it ttA«»ll#^ 

■ ft ^aiBttK^' 



L M 

FREQUENCY 

METER 

witH book. OK. $49.00 



TD 2 MICROWAVE GENERATOR wifh WE 416B, 2C43, 
etc* Complete os shown, output of 3700-4200 mc. 
Eloborote tronsmiHer used by WE for microwave 
tronsmfsilon. Frequency multiplier stages may be 
tapped for lower output frequencies, makes nice 
itoble pump source for parametric amp., lab 
signal source, etc* $40.00 

With extra amplifier stage ond tube 50,00 



NEW Catalog #62-Wi just out. Send one thin dime for handling charge. 

Afl materia! FOB Lynn» Mass, 
JOHN MESHNA JR-. l? ALLERTON ST,, LYNN, mass, tilTJ LYiin 5-2275 



11. 



12. 



13 



9, Remove the poLuiitiometci R41 and brack- 
et, located on tlie top rear oi the chassis. 
Cut the wire leads free near the poten- 
tiometer terminal and leave them in po- 
sition, 

10, Remove the wires from the POWER 
switch, tie tngother, solder and insulate. 
Remove the white wire witli blue and 
orange tracer from the MOTOR switch. 
Remove the groimd connections from pins 
A and C of receptacle SO-1. 
Attach the white wire, with blue and 
orange tracer, which was removed from 
the KIOTOR switch, to one lug of the 
POWER switch. 

14- Attach the other end of the wire which 
was attached to the motor, to pin C of 
SO-1 connector, 

15, Cut the white wire w ith green tracer from 
tlie MOTOR switch and attach to the 
other Ing of the POWER switch. Pins C 
and D of SO-1 now become the ac switch- 
wires to turn ac power off and on. 

The bandspread tuning knob will project out 

of the top of the case, since tliere is no front 

panel space available. 

16- A three-eighths inch hole is driUed in the 
top of the cast alumfnimi motor housing 
located 11/16 inch from the front of the 
case^ and li inch from the left. A shaft 






We spent our years advertising budget 
in October, so look back on pages 40 
and 41 of the October 1962 issue of 73 
and see what we have. You'll find com- 
plete prices and ordering information 
there. 

KTV TOWERS, SULLIVAN, ILLINOIS 



bushing is installed in this hole to accom- 
modate a length of M inch diameter shaft 
and solid shaft coupling. The bandspread 
timing will be engaged by throwing the 
MOTOR switch to ON, which engages 
the electric clutch in the turang mecha- 
nism. When fast tuning is desired, the 
MOTOR switch is thrown to OFF and 
timing is accomplished with the TUNING 
knob. 
Parts are now installed to provide dc voltage 

to energize the clutch. 

17. Mount a 6,3 volt L2 amp. filament trans- 
former under the chassis on the side lip 
near the SO-1 connector. Refer to Fig. 1 



DECEMBER 1962 



87 




73 MAGAZINE 



TO PIN 
OF V4 




SOO A 

— vw 



IN93 



ItOV 



""^t" 



TO WHITE 
^ WIRE WITH 
■* SLUE 

TRACER 



10-I50V 



MOTQfi 



FIG. I 



Tr 



18. 



19. 



20, 



21. 



22, 



23. 



24. 



1. 



2. 



for the sclienivttic of this portion o£ the 
modification- 

Connect one of the 6.3 volt leads of tlie 
transformer to pin 7 of 6SA7 tube V4. 
The center tap connection of this win ding 
is not used, so cut the lead oflF close to the 
transformer winding. 

Remove the wire with bluL^ tracer from the 
MOTOR switch. 

Connect the other 6.3 volt lead to one con- 
tact on the MOTOR switch. 
Connect the other switch contact to a con- 
venient ground* 

The 500 ohm 5 watt resistor, the 1N93 
diode, and 10 mfd capacitor are conveni- 
ently located near the transformer on a 
three lug terminal strip and wired as 
shown in Fig. 1. 

Connect the wire with blue tracer, wliich 
was removed from the MOTOR switch, 
to the junction of the 1N93 diode and the 
10 mfd capacitor shown in Fig, L 

Addiflon of SEND-RCV Switch 

Drill two holes in the front panel which 
will accommodate a SEND-RCV switch 
and a pin jack (RCA Phono Jack) for a 
keying relay connection. Due to the close 
spacings and limited panel space available, 
care must be exercised in location of the 
two holes. A % inch hole for Uie SEND- 
RCV switch is located 5% inches from the 
left and 1 13/16 up from the bottom. A 
three-eighths inch hole for the pin jack 
is drilled 6 inches from the left and 2 7/16 
inches up from the bottom of the front 
panel. Refer to Fig, 2 for the schematic of 
the circuit. 

Estimate the length of ware needed to go 
from pin A and B of SO-1 to the new 
SEND-RCV switch, a SPST toggle switch 
on the front panel, and install these leads. 
Do not solder these leads at the toggle 
switch at this time but solder at pin A 



SOI 






NEW 
#) PIN 
JACK 



FIG. 2 



TH 



ARC-3 and ART-ISA TECH MANUALS! 
Handbooks matnteir., op&r.^ theory^ seheni. dwfls, €iAAn 
fltft. Either book postpaid * fJU,l/U 

RADIO RECEIVER AND/OR SPECTRUM ANALYZER 
AN/APB'4 rtvr i& the ll-tube 30 me IF etc. for is 
plug-in tunlnf unltir has S-meter, 60 cy pwr Wiy* 
Pafi, VidflQ L Audio outuuti. AM. CheckwJp artgned. 
with h«ads fiH- Sa-IOOO ni«, tlAAaCk 

pwr plug ^ H andbook, foli Lw Anf. »lO*l*WU 

Add $59.50 for 1-2.2 kmc^add $79.50 for T*st Oscillator 
TS-47/APR, 40-3000 mt ±1%. CW, AM. PM, w/built-ln 
m cy pw«r iply. fob Lo» Aug. Add $45.00 U ffet AM/FM 
rcvr initead of AM. 



2- METE ft RECEiVER & 2/6/10 METER XMTR 

SCR -522 reyr, imtr. meli Ml 
cas«, oKC. cond. id tubes »rt- 
cludt aSU's, lOO-lse mc AM. 
Sat lif act ion frtd. Sold at less 
than the tubo eost in surolus. 
Shpg wt 85 lb$. Fob Bremerton. 
Wash. 
Only »,^....«*, 

Add $3.00 tor eompbte tvcbniemi 
data group including oriainai 
sehefnaties 4 parti liiti. IF, xtl 
f^rmuias, instruct tor AC pwr 
sply, for rcvr continuous tuning. 
for xmXr 2- meter UMj A. for putting 



$14.95 



xnitr on 6 &. 10 meters. 



2nd 



eoflVerL 

$12.95 



COMMUNtCATfONS RECEIVER BARGAINS 

eC453B: 190-550 kc fi-tube ^uperhet w/85 kc IF's, 

a^ long-wave rcvr. a^ tunable IF &. as 
W/aii data. CHECKED ELECTRICALLY 
Grtd. ok: 11 lbs. fob Lo* Angeles 

Same, In handiome cabinet w/pwr spiy. spkr, ^•- -* 
ett,. ready t^ use, H our ax-535, 19 lbs. --• *^'-?" 
RB$* Navy's prLdo 2-20 me 14-tube supern«t nas volM 
filter for low noise, ear*saving AGC, high sens, & select. 
IF is 1255 kc, Cbeiiked, aligned, w/pwr spiy, eords. 
teth data, ready to use, fob Chiarleston, S. C. *^a m^ 
or Los Anqeles -.„,.- ,,-.•..-. ?/t,3u 

g-45/ARR'7 brand no*, 12-tube auperhet .55-43 rac in 
6 band*. S-meter. 435 ke IP's, xtl Alter, 6 scl. positions, 
etc. Hot and complete, it ean be maife stiti better bv 
di>ab1e-eonvertin» into the BC-453 or QX-535, Pwr sply 
includes DC for the Automatic tuning motor. }| 79,50 
Fob San Antonio ..^»f»*>**#* #»#4»a »»••-■•*■ 

Time Pay Pian: |l7.i5 down. 11 x $IG.03 

Wrife stating your specific needs in lab- 
type test equipment: Scopes, Signal Gen- 
erators, freq, meters, etc- etc. 

R. E. GOODHEART CO. 

Box 1220-GC BCVEIILY HILLS* Ci^LIF. 



Special Introductory Offer 



t m *i * * 



SCH 522 TniiiKif^lVcr 2 niPier or 2/6/in oti 

t?o[iipU-tct wJili tiil^t^s uud 4 random irrystal^ 

R4/ARR2 V*T«atiU* HiTpfver. ...,....*,*.- - 

Tfil/AXT2 420 MC TrttimijlUer. , . . . . ,, 

BC 029 ^rope *,« 

ID59 APAII Siopo. 

ALA Scope {S«me mm IPlS.MPAll) 

BC 375 TrHnsmliter (Ivas T. U*K..< 

T67,ARC3 Transmitter,. 

RM 52 ivhnne Puldi. 



»' •'«-«'*i * 



A > ■ * - 4 * 



* * * • « 



Trans, 

.^New 

I N 

. Ly N 

Esc 

■fa » it ■• ■ » « It* *'%«.■■ 

New 



SA azS U (V^axUl Switi?h <B«0 Aug. 73* ,..WN 

RTT¥ SSB Klc.—etc. Versatile MultlmatHi 

Trahsf<>rmi?r «•••..,, 1 . , * , . ^ . . * . — --- - • ,New 

BC 433 B IT Bsnr! Tlec. (40O ryrle) „ ...Esce. 

APS 13 liiO MC TriiiiM'«?h'er=cliassis onls^ — l^s tubes 

with rtmv. iiiita_..'^.' «i..««,^. ......#•*-,« 

255A K*n' V^ i*al«r Belay * * , * * ..-.-. 

A PX G TranE[Kiiiui|*'» . ..«.«.eii«*t«*'*>«ii*<^>. •'---> <'■ 
TZ^S/URW 3 6 Meter Transcelrer— same as BC IISS 

N { - C a d Jl at terl e$ 1 - 2 v , .»< t.m-*******',^*''*^^-***'-*'-^- 

Btower AC-IK 12 V to 65 V....... ....-,**,*- 

MO 7 Modu]ator....««4. «*....... _New 

DC 45a CT21 ) 5-7 >rC. , . . » * Xew 

BC 457 («a) 4'S.3 MC Ne**' 

I 1 15 » ' ■> JaL ir. .• »■ -. *#i#i.#*.-*»».--.»Ti ew 

fl G 54 Coax 5^ Ohms .,-,... $935 per 380' 2.95 

aC 1206 2IJCI 400 KC- RHi. Less Tubes 

Tubes — Headuetfi — -Mikes — Components 

Dynamotors — Transformers 

Send for Cat. #562, 

ARROW SALES-CHICAGO, INC. 



7^95 — ^Used 
7.95— Hied 
7.05— iTied 
7-95 — Used 



$14,95 
$1.95 

10,115 
14.95 

12.1*5 

15,1*3 

1,95 

$12.95 

.79 
9.95 

1.65 

2.95 

14.95 

39.&5 
1,75 
2,95 
5.95 
4.95 
4.95 
4.95 
per 65' 
1.93 



2534 S. MICHIGAN AVENUE 
CHICAGO U, ILLINOIS 
CA S-4750-475I 



DECEMBER 1962 



89 




mA 



J0OB2 




R& 3 



and B of SO-1. 

3* Estimate hvo lengths of wire to run from 
the toggle SNvitch to the pin jack. The tog- 
gle switch wire from pin A of SO-l goes 
to the insulated lug of the pin jack and 
the other wire from the toggle switch to 
the ground lug of the pin jack. Solder all 
these leads at this time, 

4. The main hining dial, front panel^ and 
knobs may now be reassembled. 

Improvement of "S" Meter Circuit 

It was found that the maKimum deflection 
that could be had from the local broadcast 
signals was S-6 with the original circuitry. The 
following changes will improve the circuit. 
Refer to Fig. 3 for the revised circuit, 
1. Replace the 6SK7 tube V5 with a 6SD7 
tube. 



TWO-WAY ^ 
COMMUNICATION CRYSTALS 



UNCONDITIONALLY 
GUARANTEED 

FAST SERVICE 

Ampriran spct^ializes In Uvo-uay eommiinf- 
t'all(*ifii. Frt'quenry i^orreUtltm date for 
G,E., Moturula, BX-A,, CylUna. Lear, 
NarcOs Ualllerafter, Link, Gonset, Aerotros, 
Heath. Betidix. Johmson. Gloli^, U.S5, Gov^t 
and many other c<impanM$. Seiid postaRO, 




Frequency Rante 
3 to 9>9 me 

3 to 9.9 me. Fund 

15 to 2^.9 fflc. T.W 

30 to 5(^ me, T.M* 



IQ to t? me. Fund 
2 to 2.H mt. Funtf 
50 lo m JBc. F.M. 
50 In 80 mx. fM. 
1.0 mt, to 2.3i ne- 



Com- 

mereial 
Oven 
O02"o 


Com- 
mercial 
Rosm 
002% 


$4-25 


S3.75 


4.23 


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4.50 


4,00 


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5.50 


4.00 


5.00 


E.OO 


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8.50 


7-50 1 



Amateur 
01** 

2QTHmf 

$2.85 



3.35 



3.35 



3.35 



4.00 



5.00 



6.50 



€,lt. ,104*^ eiTiitllty. al! I'liannels. all -eifuijiment, $2.85 
^imafeui. mt?ifr*:: S,3 to 8.6 me 6ih miiillple Tran*. FTSiJi. 
$1,50 

EHi I' YwjiisHi* Kits — Three 7 me Xilas. Two noyiiers, SL05 
WritL fof quantity discounts or phone Victor 2-5571 



AMERICAN CRYSTAL CO 

P.O.BOX 236G . KANSAS CITY 42, MO 



2, Change the 100 ohm resistor R22 to 1000 

3- Add a 1000 ohm resistor in parallel with 
the 330 ohm resistor at he cathode of V5. 

Audio Amplifier Modifjcafion 

Refer to Fig, 4 for the revised circuit- 

1. Remove the 68k resistor R39 located on 
the terminal board on the back chassis Up, 

2. Tie a jumper wire across the two terminals 
where R39 resistor was removed and 
solder. 

3. Remove the 7500 ohm 10 watt resistor 
1140 located in a cluster of four upright 
resistors under the chassis near the rear. 

4. Coimect the two white wires with red 
tracers together after removing them from 
R40, insulate and solder them. 

5. Install a 5000 ohm to 8 ohm output trans- 
former in the location on top of the chassis 
near the rear where the R41 potentiometer 
and bracket were removed. 

6. Remove the white wire with blue tracer 
attached to pin 3 of 6V6 tube V9. This 
wire leads to a .5 mfd capacitor C52 which 
is a metal can type and is tlie bottom unit 
of two stacked ones near the cluster of 
upright mounted 10 watt resistors. This 
capacitor maj^ be removed or left in, as 
desired^ and white wire with blue tracer 
may be removed from the harness or 
clipped short and left in, 

7. Install a wire from the other terminal of 
C52 to a lead of the 8 ohm secondary of 
the oulput transformer, (There is already 
a shielded wire attached to this teiTainal 
of C52j leave it there,) 

8» Tie the other lead of the 8 ohm transfonii- 
er secondary to any convenient ground. 
The white wire with black tracer wlilch 
attached to the potentiometer R41 may be 
used for this ground. 

9. Connect one wire of the output trans- 
former primary to pin 3 of 6V6 tube V9* 
Do not solder. 

Kl Connect the other primary wire to pin 4 
of 6V^6 tube Y9. Do not solder. 

IL Remove the 100k resistor R47 connected 
from pin 3 of 6\^6 tube V9 to a terminal 



JUPlU 

ntw 

CHJTPirr 

TRANS 




^ TO SHiELOED 
WIRE ON C52 



^ TO *rHITE WlRE/BLK 
TRACER GHOyNO 



FIG .4 



m 



90 



Subscribers needed badly 



73 MAGAZINE 



FALL SURPLUS SPECIALS DE K2BBC 



Reod-N-Sove 



DB Meters ^<4" rcf —10 to +6dei Imw @ 600 ohms 

NEW 

Sperti Vacuum Switches for ART-3J, etc. NEW 

M*359 Coax Right Anoles ^^5 for 

Velvet Verniers w/laroc knob NEW 

600 Ohm 300 Watt Non-induttive Resistors 
WE-255A Polar Relays for TTP ___„__ 

Sockets for yse with above relay . 

Dummy Loads 27 to 40 mcs 30 watt A g3 



Chopfei-s Stvns Arnold ^222 AC-DC llOvdc max 

NJcad Storage Batteries l,2v Samp hrs. ^, ., 

Sank of 10 batteries in pfastic case (12v) 

Chargers for above (12¥) llSac input 



$2,75 
$1.00 
$1.00 
$1.00 
$2.50 
$4.50 
$2.50 
$1.00 
$5,00 
$2.00 
$17.50 
$4.95 



NEW SURPLUS TUBES GUARANTEED 



2C39A _,, $7.50 
3CX100A5- S14.50 
afil -.,, $35.00 
8296 $9.50 



6F4 ( acorn )-$L75 5Sgl 

lOOTH -. $1L00 6AN5 

250TH $18.50 ^46 

6159 ^^-^ $3.75 44€A 



._ $1.50 

._ $1.25 

._ $2,95 

- $0.50 



MONEY BACK GUARANTEE ON 

ANYTHING we SELI 

We stoct large qudnfifies of Military and Com- 
mercial Tesf Equipment* We buy AN/GRC, PRC, 
TRC and test equipment TS and AN/UPM or 
URM, What have you for sale or trade? 



Dumont Scopes 256D ^- 

304H ,..^^„.. 



SIIO.IW 

$19S.O0 



SPACE ELECTRONICS CO. 

218 West Tremont Ave.* Bronx 53« N. Y. 

TRemont 8-S222 



6AB7 



C95 
.0082 



ANT 



f 




StJC 4 



R5T 
470K 



C79 — 
.0082 



F!0 5 



TM 



12. 



board on the rear chassis apron. Removal 
of this negative feedback resistor will re- 
sult in greater output and better com- 
munications qualit\r, 

Install a -02 mfd 600 volt capacitor from 
pin 3 to pin 4 of 6V6 tube V9 to reduce 
high frequency response. Solder tlie con- 
nections. 
Either headphones or a speaker may be 
connected to the PHONES jack. 

Low Impedance Anfenna Input Stage 

Refer to Fig. 5 for the revised schematic. 

1. Remove the wire lead from pin 5 to pin 3 
of 6AB7 tube V12. 

2. Connect a wire from pin 3 to pin 1 of this 
tube socket and solder, 

3. Remove the ,0082 mfd capacitor C79 from 
the terminal board on the underside of the 



807 Tubes, new . _ ^ $l*oa 

Removed from equipinent & tested 6 for $5.(10 



Sockets for 4X1 50 A etc. _ 
Eimac #SK-610 ,— 



$6.50 ea. 

... ^2/12.00 



T-n9 AKT-26 Transmitters 300-GOOmc, 35w 
Brand new w tubes, for ham TV ^_S59.S0 



SP-600-JX Receivers ,545-54 nic 
Like new 



-^$425.00 



Model 15 TTP complete with synch, 

motors. ExceUent ... «___ __522S,00 



Berkeley Model 550OC Universal 

counter & timer Lab tested— perlect--- -5425,00 



Low Freq. Marine Heceivers— RCA 
,"i bands 240 to 2000 kc— 115vac 
New condition ^^-_— — 



$6B^ 



BC-463A Transmitter and Modulator 

converts to 6 mtrs. uses 

815 tubes. New with tubes 



$19.50 



Coax Relays SP3T 28vdc 

General Communications 3N120RC or 

Thompson Products 10566, New $1735 



Bird Model 6250 Mitliwattmeter 

0-250mw, 30-500 mc. for Handi-Talkies 

New -.^- — $42,50 



chassis near the tube socket of V12. 

4. Disconnect the center wire of the shielded 
antenna wire lead where it terminates at 
the terminal board on top of the chassis 
near the 6AB7 tube V12. 

5. Ground the terminal from which this wire 
was removed, 

6. Connect one end of a ,0082 mfd capacitor 
to the free end of the wire removed in 
step 4 and add on a piece of wire to the 
other end of the capacitor, long enough to 
go through the chassis grommet. Connect 
it to pin 5 of the 6AB7 tube V12, 

A typical power supply is shown in the 



POl 



HV. 
CTAP 

PWFtSW 

PHWSW 

6 3 VilC 

4 AMFS 

^250VDC 
ISO MA 



117 %M 




FTO S 



TU 



DECEMBER 1962 



Mention 73 



91 



schematic of Fig. 6, No attempt is made to 
design an exact supply for the receiver in this 
article^ since most users have power supplies 
capable of siipplving adequate power to the 
receiver. 

A white \\ ire with blue and black tracer will 
be left over from the modifications. It may be 
cut close and left in the harness under the 
chassis. 

A slot is cut in the cover to allow it to be 
slipped over the bandspread tuning knob. This 
shaft may be cut short enough to allow a knob 
to fit flush with the ease cover, 

A dummy knob is installed on the shaft on 
the front pane] from which the stop mechanism 
was removed. 

A bandspread dial is attached with cement 
to a % inch diameter knob and installed on the 
tuning shaft* This dial is reproduced in Fig, 7 
as a guidr rnily because each receiver will vary 
slightly in calibration and the dial will have 
to be tailored to each case, A suitable pointer 



Blank Calibration Boak for BC-221 freq. meter. 
also LM, New. boxed Dallvered $2.59 

FL-5 Filter w own BC-345 switch Delivered Sl-69 
ART-13 Plugs U-7/U or U-S/U PeliYered 52.59 ea. 

Both f#r $4.00 

Sctietnatics 29<* @ 5 for a doUar — Schematics 
SCR-522. ID-G APN-4, ARC-5-T/IS-22, ARC-5T/23, 
BC-603. BC-S83, ARC-5-H/25-27, BC-923. R-9/APN- 
4, BC-924. 

Filament Transformer, UTC #FT-5, 2.5 vac 10 a. 
sec. 115/60/1 PRI. 1500vt, New; boxed 

Delivered $2.30 

Plugs & Receptacles of all kinds, drop us 8 line. 
SATISFACTION GUARANTEED 

HI WAY COMPANY 

1147 Venice Blvd., Los Angeles 15, Ca 




for the dial is made from a short length of 
solid #20 wire which is attached under the 
screwhead of the nameplate. . , . W5U0Z 



Farts List 



1— Shaft bushing for % inch shaft 

1 — ^4 inch dia. shaft afiprox. 4 inches langr 

1^ — shaft coupHng^ for % inch shaft 

1' — 2 inch dta. bandspreiicl tuning' kni>b 

1— SPST toggle switch iSEND-RCV switch) 

1 — Pin jack (RCA phono jack^ 

1^ — % inch dia, tuning knob (mount bandspread tuning 

dial to this knob) 
1 — 6,3 volt L2 amp fllnment tranfiformer 
1—1 N9S diade 

1 — 10 mfd 150 volt elect, capacitor 
I — 600 ohm 5 watt resistor 
1 — 3 luif terminal strip 
1— GSD7 tube 

2 — 1090 ohm 'yi watt reabtor 

1 — 500O ohm to 8 ohm output transformer, 5 watt 
1 — .02 mfd 600 volt cupacitor 
I— 1 Mh rf choke 



J. J. GLASS 

THIS MONTH'S SPECIALS 

CRYSTALS 

Low Freq* for Sideband & Experimenta] lAppli- 
cations: 370-540 kc within Va kc or less. Use on 
fundamental ar harmonic. Originally used on 
54th or 72nd harmonic.__-*->4B<^ each, 5 for 92.25 
Sealed Overtone Crystals tn small Metal Holder, 
V2' Spacing: 11, 12, 13, lU. 17, IH, 10. 20, 23, 25. 26, 
27, 28, 31, 35. 36, 37. 38. 42, 43. 44, 45, 46. 47, 48, 
49. 50 MC. fractions omitted. We will ship to the 

closest fraction requested 52i} each. 3 for 1.49 

Special Purpose Crystals 



000 kc FT-241 Imliler 
2ni» kf FT "211 »ii>liler 






7%i 
L49 



200 Kr st^aliHl meial holder ...,*.....,.,.-,,,.... 1.95 

too ke in large bakelite holder 2,49 

Crystals for Test or Marker Purposes 

l.ir* 
1.1*- 
l.i*.> 



1 ,00*1 k£ In aesled metatl inilikr *^" at»a^ifig. , , 

5,00*0 kL! Ill FT'243 liold<?r , , . , , , , 

9,000 kv In E«al6d metal holder ^'* ipactn^.. 

10,1100 kc in lealed melai hotdt^r W spselng. 



I d- A *> * 



I3.00n kc In leiled meui holder ^k** ftpacine, 1,05 



in 



Very, Very Low Frequency Crystal 
sealed holder. Wtth fraction. For 
perimental pyrposcs. 4 k€ * . . . . 1.95 



WANTED! GRC, PRC He IS JElquipment. WiH 
swap or buy lor cash. 

J. J. GLASS CO. 

1624 S. Main St., Los Angeles ISp Calif. 

Rl 9-1179 (213) 



Fridays 'til 9 



Send for Catalog! 



A Constant- 
Voltage Power 

Supply 



Roy Pafenberg W4WKM 

THE subject of using salvage TV receiver 
transformers for amateur power supplies 
has been exhaustively treated in the literature, 
notably by WIICP In the QST series. There 
is, however, a power supply used in some of 
the earlier Duniont television receivers tliat 
is particularly desirable, 



92 



73 MAGAZINE 



GUARANTEED CRYSTALS! 



ALL MARINE Fft£Q.-FT-243, DC-34 Holders. ToL .DOS $2.50 

POLICE, C.A.P,, CD, MARS, lot .01% 52,00 

CITIZENS BANO-TT METERS- .005% Tol 
26.965 to 27-225 MC, 3rd Over. Harm. Seal or FT-243 . $2,95 
13.4825 ro 13.6V25 MC. 2ncl Harm.Herm. Seal or FT^243 $2,95 
6741.25 to 6d06.25 Kc, 4rh Harm. FT-243 only $2.50 



SPECIAL! 

STOCK CRYSTALS 



FT-243 Holders 5700 KC to 8700 
KC in steps of 25 KC'i 

SEND FOR FREE CATALOG 

DC-34 Holders 1690 KC to 4400 KC steps of 10 KC ea. . . .$M9 



NOVICE BAND FT-243 Fund. 

80 Meter 3701-3748— Steps of 1 KC. FT-243 

40 Meter 7150-7198— Steps of 1 KC. FT-243 

Dbl. to 40 Meter 3576-3599. Steps of 1 KC. FT-243 

15 Meter 5276-5312—7034-7083 Steps of 1 KC. FT-243 




■ 1 4- t 1 * 



FT-243-2 Meters (Steps of T KC) 
FT^243-6 Meters (Stepi of 1 KC) 

FT-243-Frofn 3000-4000 . . . . 

FT-243-From 1005-2999 (Steps of 5 KC) . . 
FT^241 SSB Low Freq. Xtats 370 to 540 KC 

(Steps of 1 .S52 and 1 .388) 

FT.241 SSB Matched Pain , 



, , f , 



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$1 .49 
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$ ,69 
$2.39 



Include 5c per crystol far postage (U- S. Only) Calif, add 
4% Tax. No C.O.D.'s. Prices subject to change, Ind. 2nd 
choice; mbstttwtion may be r^ecessary. MIN. ORDER S2.50 

"The House of Crystals" 

U. S. CRYSTALS, Inc. 

1342 S. La Brea Ave* Los Angeles 19, Calif, 



2.3*6.5 My. CHOKE hermetically sealed, 850 
ma/lOC ma. 6 KVA test ,»,,,.,...-,*-*, 12.50 

TRANSFORMEB pri, 115v 60 eye. sec 2.5v 5A, 

6500v test 5600v @ -D04A 2,76 

TRANSFORMEit. pri 115v 60 eye. Sec 6850/5400/ 
5a00v @ 40 ma *.. S.50 

TRANSFORMER, pri lOov 60 eye, low^induction 
type. Sec 6V @ 22A. 75,000V test .. 14,00 

CHOKE 1,72 Hy, 400 ma, 10 KV teet. Kenyon 3.75 

CHOKE 2 Hy, 350 ma. 7KV test, American 
Xfmr , .... 3.76 

TRAKSFORMER Pri 115V 60 eye, Sec 800 VCT 
250 ma. 5,1 V @ 4 A. 6.5 V @ 7.5 A, Her- 
metically sealed . * * * . , - 6.00 

TRANSFORMER, Pd 110 or 220 V, 60 eye. Sec 
1050 VCT @ 220 ma. 2.6 V @ 12 A. 5.2 V 
@ 3 A. .... 4.75 

TRANSFORMER, Pri 115 V 60 eye. Sec 1120 VCT 
@ 150 ma. 5 V @ 3 A. 6*3 V @ 3 A. 7.5 V 
@ 2.5 A .^, ,,,.,,.,.,......., 4.75 

TRANSFORMER, Pri 115 V 60 eye. Sec. 2.5 V 
@ 20 A .^ 2.5 V @ 20 A. 1780 V test,. 5.65 

CONDENSER, Sprague. 4000 MFD 50 V . . 1.50 

GOLD-PLATED VARIABLE CONDENSER, 20- 
245 mmf . double-spaced. . • 1.50 

E K PI 9 Los Angeles 44, Calif. 

All Orders FOB L. A. — Phone (213) PL 1-0278 



TONS OF AMATEUR EQUIPMENT IN STOCK 



SAN DIEGO 
1331 Ind?fl Sfreet BE 9-0361 



MON - FR J 8:30 tp g:00 



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94 



73 MAGAZINE 



Some of these earlier sets used a constant- 
voltage transformer to oflFset the degradatioix in 
performance at reduced input voltage. These 
transformers were mamifactured by Sola and 
were of the saturable reactor Wpe. \\Tbile they 
were used primarily to compensate for primary 
voltage variations, they also provide good reg- 
ulation with changing load. 

The RA-109 chassis^ used in many sets mar- 
ted in 1931, is typical of those using the 
constant-voltage transformer, AUliough very 
fine sets, housed in good cabinets, many are 
being junked today and a little searching will 
dig them out. 

The schematic diagram of the regulated 
supply nsvd in the RA-109 chassis is shovm 
in Fig, 1. Both the recti Jier filament and the 
higli voltage secondary windings of the trans- 
former are regulated. The inductance of the 
high voltage secondary winding is tuned to 
resonance by the 2 mfd capacitor. Because of 
this resonant condition, a high circulating cur- 
rent flows in the winding, causing this section 
of the ct)rc to become saturated. Because of 
this saturation, the secondary voltage is rela- 
tively constant over a wide range of load and 
priman' voltage variations. 

Specifically, this transformer is designed to 
maintain the dc \ oltage output constant with- 
in ±2^ lui line voltage variations of ±1055 
from the rated 117 volts. Tliis insures stable 
dc output for line voltages ranging between 
105 and 129 volts. Only one precaution is re- 
quired ill amateur use of this supply. The 
nominal 2 mfd capacitor used to tune the 
secondary is hand selected in production to 
match the transformer used. Do not change 
the value of this capacitor or much of the 
regulating effect will be lost. 

This particular supply is rated at 362 volts 
at 210 ma and no undue heating occurs at tliis 
load. This salvage power supply is a low cost 
answer to the critical voltage regulation prob- 
lems encountered in many amateur applica- 
tions. . . , , \V4WKM 



117 » 



&^ 



12. 6v 



9U4 



R0 I 




^ 56£t 

210 lAA 



eomi 



Technical Manuals 



* * I ft • 



* p * 



TM-n-215 TS-2«8 Crystal rectifier set,.. 

235 Radio set SCR-536-BC-611 , . . 

243 Radio set SCH-IiOO-BClOeO 

263 Fadto set SZR-8-8AZ-8XX 

257 Frequency ahift exciter 0,39-TRA-7 

277 Radio s-t VRC-l . .... 

283 Radio sets VRC-fi-R*257-T-2u8 .... 

284 Radio sets GRC -3 -4-5-6-7 -8 

28$ Radio sets VRC'8-9-10 •.....• 

296 Radio set AN/PRC^ 

297 Radio sets VRC-19-X-Y . 

36ft Frequency meter BC-221 all models 

352 TG-7 TG-^7 Model 15 teletype 

356 Radio teletype terminal AN/FGC-i~lC 

343 Keyer TG-:i4A ..,..., 

447 Keycra TC-lOA through J 

441 Re<;order BC-IP16 .. 

600 SCR-508 BC-fif);i BC-604 

601 SCR-ftflS BC^WI'A BC-924 ..,,. 
60S SCK-509 SCU-510 BC-620 .,, 
607 Radio set VRC-2 7-322 RAM 

611 Radio net VRC-16-17-18 _. 

612 Radio set PRC-8-9-10 ..... 
617 Radio set AN/TRC-7 RT-iS 
642 Radio set VRC-2 0,2 1-22 



* t- k m r * 



. * # . . 



• *•*»* 



* * ■ » 



. « V '«• « 



-IX 



w m m 



*' ■ * * 4 i 



*' » 1 4 . i 



p ■■ . . . 



m t n I ■ t * i i 4 « 



******* 



« * 4 * 



r**w******^t**r 



* i • » * 



* ♦ • - ♦ 



« » 9 * 



> # . « . 



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660 Introduction to Electronics , 

661 Electrical Fundamentala (DC) ......... 

6(i2 Basic Theory ^ App* of Electron Tubes 

665 Electronic Power Supplies , » , . , * , ,.,.., 
664 Theory & Use of Electronic Test Equip - 
66^ CW & AM Transmitters & Receivers.*.. 

666 ATitennas & Radio Propajratian ,.,,,.,. 
6G7 Higher Frequency Techniaues (Not MIC) 
66^ FM Transmit tern ^ Receivers 
66U Transients & Waveforms - . . 

670 Special Purpose Oscillators & Amps 

671 Cathode Ray Tubes & Their Assoc, Cirs.. 

672 Pulse Techniques ........ ^ . . ... _ 

673 Generation Sc Transmission of Microwaves 
67S Fundamentals of Telephony 
C7t> Fundamentals of Carrier lU|Mjuters 

681 Electrical Fundamentals (AC) 

690 Basic Theory & A pp. of Transistors 
820 Transmitters BC-610 GRC-26 

829 Radio set VRC-4 T-91 RlU ..., 

839 Radio transmitters T-278 T-416 

850 Receivers BC-:n2 BC-S14 HC-WI BC<;J44. 

851 Radio set SCR244 R'274 R*320 R*4S3...., 
receiver R-388 

R-390 
R-391 

R-:^92 

BC-78T-B™C 

AN/URR-2?> R-2fl0 
MS Radio receiver R-140/FSM (National HRO 

896 Radio receiver AN/FRR-12 

898 Radio receiver R-108 R-109 R-110/GRC ..• 
1191 Interrogation Set AN/TPX-20 ..**......, 

2137 Telegraph Sisrnat Converter TA-182 . 

Radio set SCR-522 .....-,.,.• 

Navships 928S2 Tranamittinpr set ANAJRT-7. 

91424 Radio set AN/PDR*27A ..... 

91707 Oscilloscope OS-8BAJ 

Na\T set RBB-1 RBC^l 

Teat sets TS-174 
Test seta TS-175 , 



8S4 Radio 
8S$ Radio 
863 Rndio 
861 Radio 
867 Radio 
882 Radio 



receiver 
receiver 
receiver 

receiver 
receiver 



«!««**• 



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We Buy Manuals — Any quantity — Any 
subject* Send check. We pay Postage. 

Technical Manuals Company 



p. O, Box 406 



Utica, New York 



DECEMBER- 1962 



S3 



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Fietory TMted GtdJ 

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TYPE VRMS/PIV AMPS PRICt 
T86i 5000/10400 0.3 lie 

T5R4 l@00/2g00 O.S 07 



'TAi FOR TRANSISTORS ft orODfSr 
Fuii Length Lmad* Faeiory Tm$$0d 

& Guaranteed! V*S Aw Mfg. 
PNP 111 Powor 15 Amp. T03 
A TO30 Roynd Pcfcg. 
2N441. 2N277 11.15, 4 for 84; 
2N442, 2N27B $5®, Z for 851 
2N443. aNl74 $4®, t fw 87: 
2K6T7 Sl@, 12 for SlO: 
SNOTTA $2®. 6 for tlO; INffTTB |3tt« 
4 for tlO; 2N6T7C S5@; PNP SNlSa, 
2N107p CKT23 4 for 1 1« » for $5; KPM 
2N292, 2N:*^S. PNP ZNS23 #30#, 15 for 
14. 100 for $22: PNP 2K67O/30OMW #40^. 
20 for %7; PNP 2N671/1W #00®, 10 for 
$5: 2N507. 2N598, 2N5&9 PNP tl.50O, 
4 for 




r25'C SILICON PNP TRANSISTORS 
250 fo 400 M W 

FULL LENGTH LEADS 
Factory TmMtmd Si GTDt 

$5 to $11 -SMALL -TOS ft TOTS Pckg. 
Replocet 2N327A; 332, 3, 4, 5, 4, 7, %\ 
474, 5, 6, 7, S, 9; 2N4aO, 541, 2, 3; 
2N935; 36, 37; 2N1034; iN1131, 2; 1276, 
7, a, 9. "TAB'* SPECIAL #69@, 7 for $4, 
20 for $10. 

$10 or more this flem, hjm pay P^P^/US,A* 



$10 or mors ttiU It^ POSTPAID U.t.A, 



RND(T036}. or 

mica kit 30# ae. 
Pinned (fiO" aq. 



Diamorid (T03> 
, Power fiael itall 

) SI, 25, 5 for $5, 



0T D I Po w ■ r« D I imo n if -Trui»t»t9rt 

Faotory Teitad 
•••MFGRD In U.S,A. 

TJniT. Eeplcmnl 
SN155, SNlSe. 1N23I. 
2N256, 2N307. 2N554 

SPECIAL T03GP 55#, 10 for S3 

40 f«r lU 
$10 or more Ihla llom we par P.P./tT.S.A. 




6A1.5 



6AfT 



■ v* e ■ « 



.59 
.59 
Hft9 
.99 
.99 
l/Pl 
.69 

t/ii 

.69 



4\250R 
4-400 A 
£501 L 
3074 
VR^2 

3ASA 
350* 

35oe .. 

«I4« . 
4S0Tt] . 



30.00 

Si.oo 

1«.00 
3/tl 
5/il 

1/ii 

■ 1410 
H 1.00 

. 2 4:; 



5I1F4 , 
5JPI , 
SjFI , 
5JPJ4 
5LF1 . 
51J*IA 
5LP4 . 
5IJ*TA 
SRPl , 
SSP7 , 



..... IOpOO 
, ■ ■ . 2,00 
..... 1.00 

25,00 

.....lt.00 

.;..,15joo 

..... 4jOO 
.....25.00 
. 1S.00 



Wonteil Test Sets ond tqutpfnent 



.59 

.75 
2AS 



1.49 

.79 



4S0TL , 
460 p, 
707B ., 
715C .. 
723.4 B . 
71SA . 
005 .. 
007 .. 
SI I .. 

iiiA . 



*...IL50 

.,,. «10.0Q 
.... 2.50 

— 5je 

! ft ■ * « -<3i|-Vd 

1. 10 

3,90 

C7S 



SI PI . 
5VPJ . 

inn . 
7ep4 . 

7Dr4« 
TBI*T . 
TBPtA 



31.00 
. S.0O 
. 4.00 



5J)0 
5.00 
5.00 
2.00 
500 



Top $$$ Paid lor 304TL, 813, SUA, 81 2A luh^i 



Kit Glisi DIodee oiiuiv. IN34A, 48. 
43. 51, M, 84. 8T. 105, lOf, lit. Iff, 
26*. 295, t2 for It, iOO for |7,S0, 



««ji;7 
&nL7 

*fl|.7 
MA 

Ai:P6 



#R5 

ftr4 

hFfi 

6116 
6J4 
6J5 
IiJ4k , 



« A -ft, ■ ft 



I -V 1 ■- ft^ « 



i- -I -^ ■ ft 



.99 
1.30 

I. It 

1,19 

.73 

.43 

2/11 

2/11 
.70 

L49 



ill 
813 

SIS 

ai2A 

a.?3A 

&£7 
8644 
954 . 
9S7 . 



• ... * 



, 3.9S 
.1200 
. 1.75 
, 7.50 
. 5.00 
.36.00 
. 1.50 
. 1.50 
lO/fl 
10/11 



7EP« .. 
7GP4 .. 
9Al#F7 . 
9JPJ ,. 
9LP7 .. 
I0IIP4 . 
I0KH7 . 
I2C;P7 . 
I20P4 . 
I2KP4A 



* * 



5.00 
7.00 

s.oo 

5.0O 
LOO 
6^00 
.IIjOO 
, 7jO0 
. 9.00 
. 9.0O 



Top $$$ Paid for 304TL TubocI 



K -p q ft 



- p ■ ■ I 



h .# a ft 



,79 

1.85 

2/IJ 

I/li 
.74 
4/tl 
L72 
2/fJ 
2/51 



991 

1619 

16M 

1625 

1626 

1629 

2050 

5517 

560V 



. S/ll 
. S/tl 
, 1,00 
, 5/11 
12/11 

. 4/ii 

, 1.20 
, 2/tl 
. i.9S 



t2SP7 , 
14EP4 . 

iAi;p4 . 

|6DI'4A 
J7AVPI 

I7CJP4 
17lkP4 . 
191>P4 



W ■ F + * 



« V « ft * H 



11.00 

10,00 
12.00 
12.00 
14.00 

14.00 
14.00 
16.00 



"TAB" 



TERMS: ill« 0r4«r S8--21% 
wHh order F.O.B. How Ymk. 
Tm tfmy iuermirtee. prito ol 
Mdte. only. Ow I till 



WE BUYl SWAP & SELL 
TRANSiSTORSy DIODES. ZENEfIS 



Fi-I«ea ■Jbtfiejt Aine mthfmmi l« 

iUma Llborty St. H. Y* 0, N. Y. t RE 2-0245 



Til'* FOM THE lEST RfTif 






>«- to 

" — N 




U ^. 4.^ *rf *« ^ ^ ii^ ^^ *.^ 4-k ^ *^ *^ *^ *^ 

i2 ?^SS£SSSi?Sv2SSZ 



TWO OeOA't end FiLAMEN 
XFMR 10 Kv Imltd SPECIAL 



^je] 



I 



Tranilitor Po«ir 
CONVERTER 

2VDC to 500VDC 
up lo 200MA 

WdffY? T«p m 

250 VDC 

DBSOO $33 

I2VDC to 250 VDC op tt I30MA 
Type CI 225 E t30 




Lmecm Nmtfill^ ChmFgmr Sytimmw 
Smmlmd SiUei»n Siud Rmcti0tr 
Finnmd Siack, Dlrmd Jt*^U«emeiil 
j FOB 8 or UTDC # lOOA* 

Try* YJ9 |I8 

'TAB" BARGAINS 

Now V«rltci/or equlr O'lSST/T.SA 113.50 
New Vftrfaen/or equlT 0-136V/3 Amp tiO.65 
0C-METER Dejur 800 Mt/2H" $3®. 

DC MTFt IMMti/tW $3@, 

RF-MTH nE:/475 Ml gc 5 Amp $4®, 2/S7 
DC-MlCTKIl On* Mft/4" Rd.. .S5®, 2/$« 
RNOOpPmBCOPK TtTBE 2''. . .$5@, 2/$9 
MINI-FAN or l2VAC/eO Cfn $2®. 3/$5 
Xmlttinff MIfra'i .006 P 2500y. 5 for $L00 

4xlfS0 rernmtt/LOKTAI. 2 for $1.00 

SftflA Xfmr. 2.5V/tOA/lflKV TnBl...$3.95 
MIcTOSwJtfh Bl/f^PNG/SO Amp 49^®, 

Tybo Clumpi TJtrtcIier. .,5 for $1.00 

.012 at 25Kt CD Condenser. .- .$4®, 
WE Choke 4ny/450M*/2T Ohmi S4@, 
Un« Filter 50Amo/250VAC, . ,$ti<a^. 
Ltfie Filter 200Amp/l30VAC, .$ie#. 

BrunlDf Parallel «" Bule 80*@, 

KS1513S Line*? Sawtooth Pot _2 for $1.00 
-*CTC" Delaj Line 1 MiCPMec'd SI @. 3/t2 
Vac-iinm rwifUra f»flMmfd/7.5Kt,S3® * 



DX. Powir Supply H5V/00 to 80O 
Cyt. Output 330 & E65 VDC un to 150 
MA. Cased SPECIAL $5. 



SELENIUM F. W, BRIDGE RECTIFIERS 

DC II8VAC 1 35VAC 
AMP |t4V0C 28VDC 



O 



Vt 

\ 

2 

3 

8 

10 

12 

20 

24 



1 1 ,00 
1.30 

2,t5 
2.00 

4.15 

6.10 

7.75 

I2,B5 

15.00 



72VAC I I30VAC 
54VDC lOOVDC 



ll.SfJ 

2.00 
3.00 
4.00 

e.on 

12.15 
f4,M 
24.60 
2d.45 



13.85 

4.90 

8.25 

8,60 

18*75 

26.30 

30.95 



$5.00 

'D. I ^ 

11.10 
13.45 

3I.!I0 
4I.&0 
43.45 



WriU For 



Send 25^ for New Cafaloq 



POTLITCK 8E^^lCONI>UCTOR KITS 
(NO OPENS OR SHOBTSJ 
SILICON STUD DIODES A8STB. 

2 to 6 Amp ,, Ofoffl 

TRANSiSTOES T05 GEUMJlNIUM 

PNP .,_..,..,, 6 lOfli 

TRANSI aTORS T05 OEBMANI V\l 

TRAN8I9T0E3 SILICON tip to 

4001fW/PNP , , , . .3 fflr II 

SILICON DIODES up to TSOMi. .18 for ll 
ZENBB DIODES up to 10 WatU..4 for |l 
110 or n^a this Item, mm Mar P.P./U.B.A. 



DECEMBER 1962 



95 



*- 




to all our Ham Friends the world over 



from the 



Allied 



Ham Shack 





W9NNR 

Ron De Marco 
(Trades d Tech Help- 
Maii or Phone) 







W90BB 

Tasker Day 

(Ham Shack) 



K9L0K 

John Chass 
(Ham Shack) 



W9HLA 

Joe Gizzi 

(Ham Shack) 



K9WLB 

Lou Green 
(Ham Shack) 



W9WHF 

Jim Sommerville 

(Ham Divtsfon 

Manager) 







K9KV0 

Rodger Nordtund 
(Ham Shack) 



In Mtfwaukee 

W9NGV 

Lowell Warshawsky 



In Mtfwaukee 
W9V0B 

Burt Fischei 



tn Milwaukee 
WN9AWB 

Neil "Bud" Cain 



ancf from all the gang (over 60-strong) at Allied 



W9CCW 
W 9 V Q D 
K 9 A V U 
W9W0V 
K 9 K W Y 
K9M D M 
W9BU D 
K 9 C D J 
W 9 T H G 
K 9 W Z E 
WN9CNV 

W9TT0 
W9S FW 
K 9 G S B 
K9G S A 
K 90 E P 
W9D C B 

W 9 F D I 



R. Ackermann 
J. Baird 
Marcel I Bell 
George Bercos 
Sherwin Berger 
Theodore Bleiman 
Larry B I ostein 
Joel Bolker 
Leo Borek 
Gordon A. Cooley 
Pauline Course 
Gerald Daht, Jr, 
Lou Dezettel 
Norman Eastman 
N orman Eastnnan , J r, 
William Efland 
Milton Fojtik 

Marvin Garber 



K 9 O A L 
WA0EBO 
K9 G T K 
K8Z R A 
WN9BTL 
W9BBH 
K 9 G H I 
K0 B Y U 
WA9ACE 
W 9 V H I 
W 9 A R B 
WN9EVD 
K 9T T F 
W 3 L X C 
K 8 Y U K 
W9RN D 
K9 K WT 
WA9DNW 



Dave Gunzel 
Brian Harris 
Thomas Ivas 
Lee Jackson 
Don Janis 
R. E. Jankauski 
William Johnson 
Charles Kaiser 
Arnold Klein 
Don Kobiljak 
Nort Lang 
Leslie Levin 
Mike Levine 
Leon Lutz 
James Marker 
Jack Matin 
Robert Oat ley 
Tom Orzech 



K9Z W K 
W9 E N K 
W9UWM 
K 8 H A H 
W 9 N P F 
W 9 K U V 
K 9 E I L 
W9 V ES 
K 9 K B M 
W 9 C 6 
K9 K D 
K9 S R W 
K 9 B D F 
W9Z J U 
W9 Y P C 
K 9 H B 
K 9 I O U 
K9 G X K 



Emmett Paschke 
Robert Patejunas 
Cliff Rati iff 
Fred Rekich 
Donald Rossi 
Seymour Sabitt 
Don Saxon 
Phil Simmons 
Da'^e Sims 
Rich Stiebel 
Wayne Strahl 
David Thornburg 
Jay Thomas 
"Doc^'Towler 
Charlie Vaughn 
Don Wisniewski 
Thomas Weismantel 
Jack Wolfson 




serving the Amateur since 1921 

ALLIED RADIO 

100 N. WESTERN AVE., CHICAGO 6 0, ILL. 



96 



73 MAGAZINE 



* v/ 



#r# 



^ # ^ 






r T 



»# 



«*fc 



^t 



♦#. 



9 » 



'■j|;„ 



!. J!^ 



NQ-170A 
$369.00 



-Mips 



iiiii lamipiiiiiiiuivn 



i^O 



fiS¥M-^^i-^^^ 



% 



mi^ff'M 






I 



^J 



'» 4 



HX-50 
$399.50 









x&mmmmm. 



~ ' 'r!-.^>i%^v''-fj. 






•iW'. 



..^rtwpiM*^ 



^;si^ 



#* 






1^ "^^ 1^ 






p • 



FROM THE GANG AT 



HAM MAR LUND 

MANUPACTURtNO COMf»ANY 

A Giannini Scientific Company 

03 W*st 2drd 8tr«*t, N*w Verk 10, N.V. 

And Factory, Mars Hill, North Carolina 



.^ 





Choose the 3est 



;x«l Trl^Bind SS& Triiiseciver: $369 



KC^303 Hifli Perform inif* 
Rtceiv^r; |449 



Hem BtfiH SSB 



NC-IOS Low Friccd Stntrsl Cov«rtfe 



«■ 



Write for big fact-filled Equipment Guide giving full 
details of National's entire line of up-to-the-minute 
communications gear. Telts you all about the new 
NCX-3 Tri-Band Transceiver . . . the 80, 40 and 20 
meter SSB rig with 200 watts of SSB sock together 
with break-in CW, AM facilities, VOX, S meter, SSB 
AGC, filter SSB generation . . , and all the other 
features you want and need for high performance 
amateur operation at home or in your car , * , at a 
price you can afford. 

This new guide also features NattonaFs famous 
NC-303 SSB/AM/CW Receiver. This versatile re- 
ceiver has the widest selectivity ^nd frequency 
range of any ham-band SSB receiver, together with 
remarkable sensitivfty and stability. The NC-303 
includes more important operating features for all 
modes of operation than any other ham-band re- 
ceiver on the market. 

One of six general coverage receivers described in 
full detail is the modestly priced NC-105. Designed 
specifically to provide the beginning amateur with 
a receiver within his budgett the NC-105 has the 



important features he needs; even a multiplier! S 
meter and product detector! The NC-105 is ideal for 
the novice or short wave listener or as a second 
receiver for the more advanced ham shack. 

WRITE FOR FREE COPY OF NEW 
NATIONAL EQUIPMENT GUIDE 

■ Complete technical details and fea- 
tures of all National gear 

■ Tells all about National's exclusive 
One Year Guarantee 

■ Helps you choose the right equip- 
ment for your needs 

A Wholly Owned Subsidiary of 
National Company, Inc. 

Export: Ad Auriema Inc., 85 Broad St., N. V. C. 

Canada: Tri-Tel A^soc, Ltd.i 81 Sheppard Ave. W.^ 

Willowdale, Ontario 

Mationa) Radio Company 37 Washington Street Melrose, Massachusetts 
Itush me a tree copy of your new Equipment Guide 





Nam0, 



♦ p#ii •■»■■♦••••»•*•• 



Address. 



City /. * .State 



-'■•'■^•••'•••«**«4*^«