Full text of "73 Magazine (February 1982)"

See other formats

February 1982 $2.9S

ISir.

^n^

)/^

\^X\'i

tH''^

•

for Builders! Page 6

&** ^

m *

-" ^

Also:

Solving the Bobtail Riddle
Requiem for Major Armstro

4 70

ICOMs GoAiTyvvliere HF Rig for Everyone's Fbcketbook

USIi *il!! CW-N

(^Qm.&pT

SHIFT

THANfiMIT
-*IC

9 3 1 1 n

L L I J. U

MOCt.

fOWlfR

■tiBauM

HF TOANSt^KIVEH

WHITE

Full Featured.

Only 3.7 in (H) x 9.5 in (W) x 10.8 in (D) will fit into most
mobile operations (onnpact car, airplane, boat, or suitcase)

Affordable.

Priced right to meet your budget as your main HF rig or as a

second rig for mobile, portable operation.

Convenient.

Unique tuning speed selection for quick and precise QSY,

choice of 1 KHz, 100 Hz or 10 Hz tuning.

Electronic dial lock, deactivates tuning knob for lock on.

Slay on frequeno' operadon*

One memory per band, for storage of your favorite

frequency on ^ch band.

Dual VFO system built in standard at no extra cost.

2D0W PEP input— powerful punch on SSB/CW (40 W out,

on AM)

Recover preamp built-in • VOX built-in

Noise blanker tseledable dme constant) standard

Large RIT knob for easy mobile operation

Amateur band oov^age 10-80M including the new

WARC bands

Speech processor— built-in, standard (no extra cost)

IF shift slide tuning standard (pass band tuning optional)

Fully solid state for lower current drain

Automatic protection circuit for finals under hi^

SWR conditions

Digital readout • Receives WWW * Selectable AGC

Up/down tuning from optional microphone

Handheld microphone standard (no extra cost)

Optional mobile mount available

ICOM

2112 116tli Amtue N.E., BeUe>iie, WA 980D4
3331 Towerwood Dr., Suite 307, D^las TX 75234

M MQied ip*<;ficQiii(Xft cm^ opp^jodimow o«nd fwt»jea to tf^onge without oooc^ or ^J^tMgo-boTi. Al ICQM lafifx fiqnikQPiitf »mc&&$ FCC I»^ji3^&n$ ImUng sftu^cxn emi»loni.

CALL US FIRST! CASH-IN ON

SERVING HAMS
BBTTER.

poll P»w«ro,W6RJ/MAWV,

other we{) kns^n hams
give you coiinsouB. 1

service.

FREE PHONE

5-STORE BUYING POWER!

FAST SHIPMENT POPULAR ITEMS FROM HUGE STOCKS.
QUANTITY BUYING MEANS TOP DISCOUNTS, BEST PRICES.

Amateurs world-wide are taking advantage of
our fast service and special prices.

• I

854-6046

9:30AM to 5:30PM

PAClFtC TIME
Monday thru Saturday.

CAUF CUSTOMERS PLEASE
CALL OR VfSfT LiSTEO STORES

FREE
SHIPMENT

(UPS Brown)

CONJtNENTAL
U.S.A.

mastfif ciUfW]

ANAHEIM. CA 92801

2620 W La Raima,

(714) 761-3033 (213) 860-2040

Betv^een Disneyland & Knot Is Berry Farm

BURLINGAME, CA 94010

999 Howard Ave.. (415) 342^5757
S miles SOulh on lOl fram S.F Airporl

OAKLAND, CA 94609

2811 Telegraph Ava . f415} 451-5757

Hw^ 24 Downtown Lefl 37th off-ramp.

SAN OfEGO. CA 92123

5375 Kearny Villa Road (714) 560-4900
hwy 163 & CJairemont Mesa Blvd,

VAN NUYS, CA 91401

6265 Sepulveda Blvd.. (213) 988-2212

San Dtego Fwy at VjcJOfy Blvd

OVER-THE-COUNTER
Mon. thru Sat. 10AM to S:30PM

AtA- ALLlA^tCi ' ALPHA ■ AMECO » AMPHENOL - Aftfli* ASTflON
^AVANtl-SENCHER* BERK TEK»BfF<0-B4W-CALt,SOOK»CDE
^COLLlMS'CUeiC^CURTtS -CUSHCH^FT. OAlWA - DAtONG
t OEM r RON » DRAKE ■ DX ENGINEERFNG - EJMAC ' NUSTLER
■ HY-GAIM MCOM ■ j WMfLLER - KENWOOD- KLM < LAREEN
*LUMAFt ' MFT^ ^ MFJ ' MICRO LOQ * MINI PRODUCTS
-MIRAGE ' tJVE « PALOMAR- ROBOT 'ROHN*SHURE' SWAN
* TELEX' TEL«EK- TEMPO' r£iN TEC* TRISTAO

SAVE substantially!

Call now for

your price

TS-130S

TR-2500

TR-7850

TS-830S

R.L. DRAKE
TR-7/DR-7

« Continuous recfltver
coverage. 1,5-30MH2

• Transmit covBrage: All
amateur bands. 160 thru
ID meters Optional pro-
gram board lor MARS,
commercial, government,
lutureliani bands.

• Up -con version w/l-f ot
48 05MHz. Hi-level bal^
anced mixer front end for
superior strong signal
handling performance.

• Truepassbandtuningn

• Standard 2:3kHz tiller
w/space for 3 optional
crystal tillers, push-
btilt on selected.

• Broadband, full solid-
state design.

• Rugged, built-in solid-
state power amplifier

• SSBtw/USB/LSB),AM,

CW. RTTY.

NEW! YAESU FT-ONE
HF TRANSCEIVER

1 " ■■*

^ *:^-^"*r^

General coverage receiver,
15DkHiro29.999MH2.

Transmit coverage: Nine
present and proposed baods.

KeyDoardfreq emry FuJfy
digitally synthesized
Mam tuning dial dr pusJi-
button scarifier in
10 onOOHz steps.

Dual VFO's.

Fuji CW break-In,

Up conversion w /first
l-F at 73MH^

Diode ring first mixer

Optional BOOHz or 300Hz
crystal filters,

Variable band widtti

l~f shift

Speech processor.

Digital feadotit tor VFO.
memory ctian.. RIToffset.

Noise blankar

240W pep input, SSB.

115/220VACof13,5DC
operation.

CALL FOR YOUR PRICE

Etp alpha

All ALPHA ampfifiers are in stock
for last delivery

CALL FOR SPECIAL PRICES

COLLINS/ROCKWELL
KWM-380

Umited quantity priced lower
tiian current dealer wholesale.

Prices are increasing!

PHONE TODAY. SAVE I

Pnces. specidcaiions. descriptiot^ subj&ct to chants >M7thmil noiio*. Catit. residants please add satos tax

73Magaztne • February, 1982 3

INFO

Manuscripts

Oofltrttmilons In the form of minu-
icrtpts with dfvwirigs and/Of ptioto
grap^i ara welcome and wtll te cofv
»id«r»d itm possible publicatkMi. We
etifi t«sum» no rsspQr(3iblltlY for loss
or damA^i to any matdrial. Pl«a5«
ti^closs a aTainp9d, seif-addreisad
anvelot>« with oach submis^loi), Pay-
mom for thu U3« of any un&ol^cllad
rriatorlal will ba made upon acoap^
t»nc^. Alt contributions should b9 dl-
reclftd (o the 73 editorial offices.
"How to Wrlie tor 7T guldahnea are
aval table upon request.

Editorial Offices:

f'ine Street

PetBrt)orough NH 03458

Ptmne; 103^4-3673. §24^74

Advdflllslng Offices:

BmSt/eet

Petefborough HH cmse

PhOfw: e03^4.7!;te

Circulation Offices:

EimStraei

P»t«nMrougH HH 03456

Phone: Q||3%4>7296

Subscription Rates

In IM UnUad States and Posacaalmvi:
One Yur f12 iasuaa) S25.00
Two Yeaf^ (24 Issues) $38 00
Three Yman (36 ia^u^) £5100

fisewhere:

Canada^W7.00/1 year only, U.S.
funds. Fofeign surface maia--i35.0C^1
yair only, U.S. funds. Fomian air
mail— $62,00/1 y«ar only, U.S. lunda,

To subscribe,

renew or change

an address:

Write lo 73 Mag&£(tie, Subecrlptkin
D«$}af1ment, PO Box 931, Farming-
da la NY 11737, Fof renewala and
changes of addreea, lF>c]ude thb ad-
Ctm^ l«bet from your mc^ lecefit
iaaua of 73. For gift stitacftptlQrm. in-
ctude iNiur nama and adcfrms ae well
as tlwsa of gift radplents. Rosimaster:
Sand ftarm 1(3679 to 73 Magsim^, Suth
icnptk>n Sef¥lcaa, P.O. BonSS!. Farm-
ingdaie. NY 1*737.

Subscription

problem or

question:

Write (O 73 Msg&ittm, SubscHinion
Department PO Box 931, Farminodala
NY 11737 Pieafl9 l«ioliid« an address

73 MsgaiinB (l$5N 0096-9010) ts pub-
tl«t^ed monttily by 73, Inc., 80 Pine
Streeip Peterborough NH 03456. Sec-
or^d olas9 postage paid at Peterbor-
oogh NH 03458 and al additional mail-
ing offices. Copy rig hi (c) 1961 by 73,
Inc. All riflhlta reaerved. No pari of this
I publication may be reprinted or oiher^
I w^se repfodiiced wlihout written per-
I mission from the publisher. Microfilm
I Edition— University MIcfotilm, Ann
I Arbor Ml 48106.

Antenna Baiuns

Model PB M4.g5

350 watts PEP. 1 .7 to 30 MHz. Low cost. High performance. Just
right for transceivers. Specify desired ratio from table below:

Mod«l

Ratio

Matches
50 ohms to

PB*1

1:1

50 ohms

PB-1 5

1.5:1

75 ohms j

PB-2 1

2:1

100 ohms

PB-3

3:1

1 50 ohms

PB-4

200 ohms

PB-5

5:1

250 ohms

PB'6

6:1

300 ohms

PB-7.5

7.5:1

375 ohrns

PB-9

9:1

450 ohms i

PB-1 2

12:1

600 ohms

PB-1 6

16:1

' 800 ohms 1

Model 1K
$32.50

1 Kw CW, 3Kw PEP input. 1:1 or 4;1

2 Kw CW, 6 Kw PEP input. 1:1 or 4:1

Beam Balun
$57.50

2 Kw CWp 6 Kw PEP input, 1 :1 or 4:1

MqiiwCard

Send for FREE Cataiog

To ordBTf add $3 shipping/handling, California residents add sales tax.

4 73 Magazine • Februarv* 1992

The Fun-Oscillator

— a simple, goof-proof vfo for your QRP
transmitter.. „„.,WA9RBR

Build this Afitennalyzer

—you'll need a weekend

...WIBG 16

hb. 82

MAGAZINE

The Father of FM

— the tragic story of Major E, H. Armstrong
, , Hammond

The Art of Listening

—audio accessories explored ...W8FX

A Dish Antenna Anyone Can Build

— no hyperbole, just a parabola

W8DIY

h4itoft*'4

Police Freqs for the TR-2400

—a sleepless night for the mod squad

Those Amazing Bobtails

—the current-fed connection W1XU

Shoot the Moon!

—visual tracking for your EME array

W9CCA

CQ MARS de IC-2A

— work new worlds............. .,

WDSJLW 46

^b's Own LNA

— rolling your own takes patience

..,. , WA4CVP, WA40SR 92

Microwave Master

—you might not need a

mountaintop. ...... ................WB4APC 96

CW Interface

[3 -^let your computer do the copying

W9fD 104

Never Say Die — 6, Social Events — 48, OSCAR Orbits — 83, Ham Help — 98, 122, 139, Reader Service — 114,
Review — 118, Letters— 120, Fun! — 123, Awards — 1 25, Kahaner Report — 127, Contests— 128, RTTY Loop — 134,
New Products— 135, Propagation — 178

Cover Pastel lliustration by Wiltiam Geise, Wrfton NH.

73 Magazine • February, 1982 5

W2NSD/1

KEVER SAY DIE

ec/itor/a/ by Wayne Green

NOW, THE GOOD NEWS

The easy passage of the Gold-
water ham bilt through the Seiv
ate was certainly good news. . «
and will bring closer some badly
needed changes In the funda-
mental rules by which the FCC
has had to operate.

Another bright spot was a bill
entered m the House (in Novem-
ber) by Rep, Timothy Wirth of
Colorado. Let me gtve you
quotes on some ol the provi-
sions of this bill. . .

Authorize use of smaieur volunteers
for examiRation prdparation

Section 44f> is amend©<i by adding
at the end thereol the (ol lowing new
subsections:

"4{f){A) Noiw I 111 standing Ihe provi-
sions of Part III of Title 5, United
States Code or 31 U.S.C, 5665(b). for
purposes of administering any exam-
tion for an amateur station operator
license, the Commission may accept
and employ the voluntary and un-
compensated services ot any indlvld-
yai who holds an amateur station op-
efalor license of an equal or higher
Class than the class license for
vvhich the examination is bemg pre-
pared. Any person vwho provides ser-
vices under this paragraph shall not
be considered, by reason of having
provided such sen/ices, a Fedeiai
employee for any purpose.**

Explanation

This proposal would provide a stat-
utory basis for present practice at
the Commission, and would allow ex-
panslon m the Commission's use of
volunteers. The amendment would
have no discernible effect on our
budgeta ly req u i re me n t s.

''Mf%5} Notwithstanding the provi-
sions of Part III ol Title 5, United
States Code or 31 U.S.C. §665(b), for
purposes of administering any exam-
ination for any amateur station oper-
ator license, the Commission may
accept and employ the voltjntarv and
uncompensated services of any indt-
vidua! who holds an amateur station
operator license of an equal or higher

€ 73 Magazine • February, 1982

class than the class license for
which the examination is being con-
ducted. Any person who provides vol-
untary and uncompensated services
under this paragraph shall not be
considered, by reason ot having pro-

vided such services, a Federal effV
ployee for any purpose."

Expf a nation

The present practice of the Com^
mission is to permit volunteer licens*

$$ HOME-BREW CONTEST $$

For some of us, there is no more satisfying experience than
designing and building a piece of electronic gear. Now there's a
chance for you honne-brewers to receive special recognition for
your achievements. It's the 73 Magazine Home-Brew Contest.

Between now and April 1, we1i be looking for articles de-
scribing the best home-brew protects in the lar>d for under
SI 00. All useful projects will be published in 73, and the cream
of the crop wift share $500 in cash prizes. Top prize in the con-
test is $250, with $10Q going to the second place project and
$50 to each of three honorable mentfons. These prizes are
over and above the payment that all authors receive for hav-
ing their artictes published in 73,

Contest Rufes

1. All entries must be received by April 1,1982. To enter, write
an article describing your best home-brew construction pfo-
ject, and submit the article to 73 Magazine. Any construction
article received before the April 1 deadline is aulomatically
entered in the contest. If you haven't written for 73 before,
please send an 5ASE for a copy of our author's guide.

2. The total cost of the project must not exceed Si 00. even if
al I parts are puchased new. Be sure to i nclude a detailed parts
list, with prices.

3. All parts used In the project must be available to the aver-
age radio amateur or electronics experimenter. To be on the
safe side, include sources for any unusual components.

4 Projects will be judged by the 73 technical staff on the
basis of usefulness, reproducibility, economy of design, and
clarity of presentation. The decision of the judges is finaL

5, All projects must be original, i.e., not previously published
elsewhere.

6. All rights to articles purchased for publication become the
property of 73 Magazine.

Send your entries to:

Home-Brew Contest

73 Magazine

80 Pine Street

Peterborough NH 03458

Winners will be announced in the June^ 1982, issue of 73.
Have fun!

ees holding an Amateur Extra^ Ad-
vanced, or General Class license who
are al least 16 years of age to admin-
ister Novice Cfass operator license
examinations. The proposed amer>d-
rttent would give statutory recoflni-
lion to this practice and would allow
the Commission to 6)clend tr>6 praCr
UcB lo examinations tor other
classes, al the discreUon of the Com*
mission.

This program would help to corv
serve Commissiori resources and ad-
ditlonal benefits would result from
the fact that applicants would likely
be able to take examinations within
their communities, as opposed to
having to travet to FCC field offices
for testing.

Once the FCC has t>een auth-
orized to let amateurs prepare
and administer exams, we have
the path open to set up a system
whereby certain clubs might be
able to hold classes to teach the
needed theory, rules, and opera-
tion skills to prospective
hams. . .followed by oral exams
and a demonstration of skills.

While there are some ama-
teurs who believe that the ten-
sion and panic of an FCC-ad-
ministered exam are beneficial
in some way, that was not my
experience... nor the experi-
ence of anyone Tve talked with
about it. There seems to be a
general concept that we should
do everything possible to keep
enthusiastic people out of the
hobby rather than doing all we
can to interest people In it. , ,
and making their entry an enjoy-
able experience,

There seems to be some wari-
ness that we will suddenly find
ourselves with a system where
we are bringing in people who
will be rotten hams and thus
spoil the hobby. I wouid say two
things to those worriers . . . first,
we already have a fine system
for bringing in lousy hams, one
which has been working with a
high degree of perfection. On©
has only to visit Los Angeles to
get the full flavor of the
I980s-type ham in full bloom.
It should be obvious that the
present system of filtering out
the weirdos is not working
worth beans.

Secondly, t know of no one in-
terested in opening the flood
gates to CBers to come into am-
ateur radio for a tree ride. Not
even CBers have suggested any-
thing that preposterous, I do
hear hams opposing it, but
these chaps are merely lighting
their own straw man, not any*
thing ever seriously proposed. If
some hams are gullible enough
to get excited over such ma-

■jii,rt»#J»*B*fM****

HI AM

yv^

^^'■"j-'-i-i

wwti n-eocD

low hear

• •*

igital display/ front
ipeakeiv easy tuning

[he R-eOO is a high
performance, general coverage
iommunications receiver
fevering 150 kHz to 30 MHz
30 bandSt at an affordable
^rice. Use of PLL synthesized
cifcyitry provides high
accuracy of frequency with
maximum ease of operation.

R-600 FEATURES:

• 160 KHz to 30 MHz
continuous coverage, AM,
SSB, or CW.

• 30 bands, each 1 MHz wide»
for easier tuning.

• Five digit frequency display,
with 1 KHz resolution.

• 6 kHz IF filter for AM (wide),
and 2.7 kHz filter for SSB,
CW and AM {narrow).

• Up'conversion PLL circuit.

for improved sensitivity,
selectivity, and stability.
Communicatrons type noise
blanker eliminates "pulse-
type" nofse.

IRF Attenuator allows 20 dB
attenuation of strong signals
Tone control
Front mounted speaker.
"^S" meter, with 1 to 5 SINPO
scale, plus conventional
"S" meter scale.
Coaxial, and wire antenna

Digital world clock with
two 24-hour displays,
quartz time base

The HC-10 digital world clock
with dual 24*hour display
shows local time and the time
in 10 preprogrammed plus two
programmable time zones.

terminals for low impedance
(50 0), Wire terminals for
high impedance (500 Q).

• 100. 120, 220, and 240 VAC,
50/60 Hz. Selector switch on
rear panel.

• Optional 13,8 VDC operation,
using DCK-1 cable kit,

• Other features: carrying handle,
- S headphone jack, and record jack.

OPTIONAL ACCESSORIES:

• DCK 1 DC Cable kit

• SP-100 External Speaker.

R-iaao

^ear there and everywhereT..
easy tunings digital display

The R-1000 is an amazingly
easy-to-operate, high-
performance, communications
receiver, covering 200 kHz to
30 MHz in 30 bands. This PLL
synthesized receiver features a
digital frequency display and
analog dial plus a quartz
digital clock and timer.

R-1000 FEATURES:

* Covers 200 kHz to 30 MHz
continuously.

30 bands, each 1 MHz wida
Five-digit frequency display
with 1-kHz resolution and
analog diai with precise gear
dial mechanism.

BuiltHn 12-hoyr quartz digital
clock with timer to turn on
radio for scheduled listening
or control a recorder througn
remote terminal

Step attenuator to prevent
overload.

• Three IF filters for optimunn
AM, SS8. CW. 12-kHz and
6 -kHz (adaptable lo 6-kHz
and 2.7-kHz) for AM wide and
narrow, and 2, 7 -kHz fiiter for
high-qualitv SS8 (USB and
LSB) and CW receptioa

• Effective noise blanker

• TerminaJ for external lape
recorder.

• Tone control

• Built-in 4-inch speaker

« Dimmer switch to controf
intensity of S-meter and other
panel lights and digital display.

• Wire antenna terminals for
200 kHz to 2 MHz and 2 MHz
to 30 MHz. Coax terminal for
2 MHz to 30 MHz.

• Voltage selector for tOO, 120,
220. and 240 VAC. Also
adaptable to operate on 13.8
VDC with optionai DCK-1 kil

OPTIONAL ACCESSORIES:

• SP-100 matching external
speaker

• HS-6 lightweight, open-air
headphone set.

• HS-5 and HS'4 headphones.

• DCK-1 modification kit for
12-VDC operation.

SP-100

R-1000

HS>S

^ ►

KENVUOOD

TRIO-KENWOOD COMMUNICATIONS

1111 West Walnut, Compton. California 90220

STAFF

EXECirriVE VfC£ Ff«£SlDiKT

ASSISTANT PUftllBHEIUlDiTOn
JefJ D-eTray WB$aTM

ASSOCIATE PUBLlSHtE A/ OJ RECTOR
OF PUBLICATIONS

Edward Fermfln WATUFY

MANACilNCI EDITOR
John fiufnall

A5ST. MANAGING EDITOR

Susan PhiF^nck

EDrroniAi assistants

CONTfl'»'i^^C: eDlTOHS
John - T AG^

Tim OaAi«i NSf^K
Urry ftanai)**^ WS2NEt

ADMINISTRATIVE ASSISTANT
P2I Gf «fiAm

ASSOCIATES

RoberTSflk^FWe^GFE

Bill Gosrt»y Kf 7C

Sanger Greep

Dave ifiEfrim KiTWJ

Joe Kaster Q3ZCZ

Dr. Mafc Leav&y WA3AJR

Bill Pasternak WAfilTF

Pete; Slarh K20AW

PRODUCTION MANAGEIlf

PUBLICATIONS

Naricy Salmon

ASST PPODiJCTlON
UANAGERS^PUeilCATlONS

MicritftI m^pHy

ADVENT! SI N{J GRAPHICS

MANAGERS

Sle»^«f BdhdA^ri

Bruce He<l!r>

J3n9 Prntofi

PAODUCr/ON

Fioni Dflvi«A

Linda Difiw

Sandra Oyh«irt

Mall Mil»

Dianne l^itson

Pairici-d Mackow&kyj'Aillen

Thfifssa OatpbQ

Betly Smith
Deborah StortD

Irarre Vail

Judi WkmlMsrry

Dcirtrta Wohllarth

W^IFtam Hty cSoIeU)

Bryan HMltn^s
liwmas VjltorNhi/ve

TYPfSETTlWO

Sdr« a4»a«j|

D«iiCiit Davidson

DavHl HBV«ard

K«l4y Snviih

Slevn Jewetl

CORPORATE CONTROLLER

Rpy A, Jphncipri

EXECUTIVE ASSISTANT

Leatrice O'NqO

ACCOUMTINO MANAQER

Krtuct K€ljQr KV4GGn

aRCULATlON MANAQEA

CiltCULATtON

QonS Day

P^ultne JoHfustorie

&ULK SALES WANAGER
G4tww SoiidMftau

ADVERTtStNO

Jim Gra'y W1XU Myr

Nancy Ciampa, A ait Mfj^r

Ross Kenyon HAlGAV

Corn«lip TaylQf

neuvers, then we should consid-
er them part of the problem, not
part of any solutions.

No, I think it is plain to just
everyone that our present lic-
ensing system stinks. Here we
have a Morse code test which a
four-year old has passed with
flying colors... big deal filter.
We have a technical e^am that
few people even bother to study
for. . . why bother when you can
buy the test answers from Bash
and just memorize the answers?
That Includes questions on
rules^ so we don't even have to
know them anymore. It Is no
wonder that we have jamming of
repeaters, foul language on the
bands, stupid pileups of DX sta-
tions, and a situation on two
meters in Los Angeles that has
to be heard to be t>el]eved.

Not only are things going to
hell in a basket^ but we have the
spectacle of thousands of hams
doing all they can to protect this
terrible system and make sure
that we get even more of the
same kind of hams.

Yes, I do have some ideas on
what to do about the situation.
And I think they will work. They
certainly are right up the alley of
the current FCC changes. The
Commission has two major in-
terests these days . . . deregula-
tion and cutting expenses. I
think that we can take advan-
tage of these and at the same
time improve amateur radio
substantially.

Let's take a look at some ba-
sics, Firstiy, yes. . . we do have
some terrible hams in our ranks.
But we recognize that, as much
of a pain in Ihe ass as these
bums are, they are a distinct mi-
nority. Okay . . . there's a hint foi
us ... a clue on how to start get*
ting out of this miserable
situation.

To me, one of the foundations
of amateur radio Is the ham
club. 1 believe that every ham
should belong to and support a
ham club. This is one of the big
strengths we have. This also is a
key to our separating the good
from the bad and the ugly, for
few of the really bad eggs ever
join clubs. The same behavior
which makes them despicable
on the air keeps them from hav-
ing friends off the air. And what
few do have the guts to come to
club meetings, knowing what
others think of them, are not
thought well of for it. Thus, \ sus*
pect that the more we can in-
volve our clubs In the training

and licensing of newcomers, Ihe
tietter class of hams we will
have on our bands. Perhaps we
could even consider some sort
of trial period for newcomers t^e-
fore their licenses are perma-
nent so that we could observe
them on the air.

We already know that the
most vicious and obnoxious of
people are quite capable of
learning the code. In fact, since
some of the worst hams we have
had have been Extra class, per*
haps there is some correlation
between ugliness and adapt*
ability to code (I'm kidding. . .
aren't I?). I think that CW is one
of the most treasured aspects of
amateur radio, but I also think
that the ability to copy the code
ES meaningless as far as deter-
mining whether someone is go-
ing to be a good ham. I think that
once we make code ability hon-
orable and stop forcing people
to learn It for the test, we will
take a lot more pride in it. Who
can really take pride In some-
thing which he has to do,
whether he wants to or not?

Clubs are an answer to many
of our problems. If we are going
to get amateur radio into any
serious growth pattern we are
going to have to have many
more and stronger ham clubs, I
would like to see ham clubs set
up in every high school in the
country. Td like to know that
every ham club has classes to
teach newcomers the theory,
the rules, and how to operate. If
the Wirth bill goes through. It
will open the way for clubs not
only to teach the fundamentals
of amateur radio, but also to
make up and administer the ex-
ams. Talk about a service being
self-sustaining!

This also would cut the cost
to the FCC substantially, I don*t
know how much they are paying
their people to keep writing new
test questions to try to stay
ahead of Bash and his cheat-
sheets, but it must be a substan-
tial amount. Then there ts the
cost of printing and distributing
the tests. If the field personnel
of the Commission did not have
to sit around and administer ex*
ams they would be freed up for
more productive work... or
even to go into the private sector
and earn money for taxes in*
stead of spending It. We sure
have a need for engineers and
technicians these days in indus-
try... a desperate need.

Monitoring

Another provision of the Wlrth
bill is as fottows. , ,.

Aiithofko u»« Qf vmatAur volimt*»ci
tor ffiontiorlng

'*4(f)^ For purposes of monitonng
arty violation of any provision of this
Act, and of any regulation made by
the Commission pursuant to this Act,
felattng to the amateur radio service,
the Gommtssion, notwithstanding
any provisions of Part III of Title 5,
United States Code or 31 U.S.C. §
665(b), may fl) recruit and train any in-
dividual licensed by tlie Commission
to operate an amateuf station; and (li)
accept and employ the voluntary and
uncompensateij services of such in-
dividual. For purposes of recruiting
and training such individual, the
Commission may also accept and
employ the voluntary and uncompen-
sated services of any amateur sta-
tion operator organ iiat ion. Any per-
son who provides voluntary and urv
compensated services under this
paragraph shall not be considered,
by reason of having provided such
services, a Federal employee for any
purpose."

Explanation

The volunteers' monitoring author-
ity should include the monitoring of
amateur licensees transmitting on
frequencies not assigned to the ser*
vice and i$ intended to permit volun-
teers to collect violation reports and
annotate arKJ summarize them few the
convenience ol the FCC.

Enactment of this proposal would
enhance the Commission's enforce-
ment efforts and bolster efforts to de-
tect and prosecute rule violators. To
ensure that a volunteer monitoring
program helps rather than hinders
the enforcement progi'am, it Is Impor-
tant that violation reports undergo
preliminary review by volunteer
organizations to help FCC personnel
cfetennine which alleged violations
represent the most promising targets
for the Commission's limited en-
forcement resources.

This amendrs\ent would not in-
crease our budgetary requirements.
It may help us to conserve our en-
forcement resources or, at least, im-
prove the efficiency of our enforce-
ment program.

If the Commldsloh Is to fully utilize
the services of volunteer amateur llc'
ensees for monitoring, as envisioned
by this proposal, there should be an
exception to Section 605 to permit
(he monitoring groups to receive end
fiisctose informaUcfi transmitted ty
amateur ticensees antS opera tors^
(See proposed amendment to Sec-
tioft 60S, infrs.)

Exempt amateur

rodiio communications

ynder certain circumstances

Section 805 is amended by striking

the last sentence thereof and adding

the tohowinQ:

Continued on page 131

0 73Magaiine • February, 1982

/*■

^<^

Store

commands,

as well as text,

for automatic execution

The Heathkit /xMatic Memory Keyer's custom
microprocessor stores up to 240 characters of

text or commands. Variable-length buffers elim-
inate wasted memory space. "Command strings"
allow text to be stored in several buffers, then
strung together in any sequence for most effi-
cient use of memory. Command strings can
also select speed, weight, spacing and auto-
repea! count.

No external key to buy

Integral capacitive "touch^" paddles unplug and
store in their own compartment inside the Keyer
when not in use. Left handed? A touch of the key*
pad and the paddles are reversed. Choose any
speed between 1 and 99 words per minute, and
any of 1 1 weight settings. Special rear-panel jack
connects mechanical paddle.

Great code practice machine, too

A "practice" mode sends random code groups of
random length and selectable types for a total of

Heathkif

6,400 different practice sessrai

Each sequence sends approximately 3,0i

characters before repeating.

Other features:

Built-in sidetone oscillator and speaker have
pitch and volume controls. Phone jack and ear-
phone are included for private listening. Complete
details on the great new ^fvlatic f^emory Keyer
are in the latest Heathkit Catalog. Or see It at
your nearby Heathkit Electronic Center*

Send for free catalog

Write to Heath Company

Dept. 011-864, Benton Harbor. Ml.

in Canada, coniact Heam Company.

1480 Dundds Slf«6t E . Misstssauga. ONT L4X 2R7.

Visit your Heathkit Store

) Where Heathkit

jL^t^^ products are

^ displayed, sold

/ and serviced.

^,See your telephone

white pages for locations.

• Unrt? of ^fe^lechrtok)gy

he US

^'S^'
**^

1 ^.

EtectFOfucs Cof pcrat»on m ihe

*^303

^ I

COM SPEC
'C-107

i^y"

I 00

c»*5

l.^

^ ^

cow^

^^07

ftitf ^^

A fresh idea!

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

need to mention our M^^n^'WJ^^ TS-32

1 day delivery and
1 year warranty*

TS-32 Encoder-Decoder

•Size: 1.25" x 2,0" x .40^

• High-pass tone filter included that may be muted

• Meets all new RS-220-A specifications

• Available in all 32 EIA standard CTCSS tones

SS^32 Encoder

•Size: .9'^x L3"x •40"

• Available with either Group A or Group B tones

Frequencies Available:

Group A

67.0 XZ

91.5 ZZ

118.8 2B

156.7 5A

71.9 XA

94.8 ZA

123.0 3Z

162.2 5B

74.4 WA

97.4 ZB

127.3 3A

167.9 6Z

77.0 XB

100.0 IZ

131.8 3B

173.8 6A

79.7 SP

103.5 lA

136.5 4Z

179.9 6B

82.5 Y2

107.2 IB

141.3 4A

186.2 7Z

85.4 YA

110.9 2Z

146.2 40

192.8 7A

88.5 YB

114.8 2A

151.4 5Z

203.5 Ml

Frequency accuracy* ± • 1 Hz maximum - 40''C to + 85°C
Frequencies to 250 Hz available on special order
Continuous tone

Group B

TEST- TONES:

600

1000

1500
2175
280S

TOUCH-TONES:

697 1209
770 1336
852 1477
941 1633

BURST-TONES:
1600 1850 2150 24O0
1650 1900 2200 2450
1700 1950 2250 2500
1750 2000 2300 2550
1800 2100 2350

• Frequency accuracy, ± 1 Hz maximum - 40X to + 85°C

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

Wired and tested: TS-32 $59.95, SS-32 $29.95

COMMUNICATIONS SPECIAUSTS

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

*^15

Mark Oman WA0RBR
528 De'tnes Court
Ft CoUins CO 80525

The Fun-Oscillator

a simple, goof-proof vfo
for your QRP transmitter

Hole: A complete kit of parts, mclyding PC board, is available from RAOIOKIT, Box 41 15. Greenville N H 03043 for $34.95 plus $2.50 shipping
and handling.

The Fun-Mitter (Febru-
ary, 1981, 73) and Fun-
Ceiver (|ulv, 1981. 73) pro
vided the home-brew-ori-
ented amateur with the ba-
sic components for a home-
brew station setup.

Many amateurs have re-

sponded by saying that they
need more frequency f!exj»
bility for their Fun-Mitters.
The simple vfo described
in this article is the result of
those requests. It allows
greater frequency excur-
sions than the simple vxo

Photos by Duane Bertsch

circuit of the Fun-Mitter to
provide approximately the
same frequency coverage
as the companion receiver.

The vfo follows the same
guidelines as the two pre-
vious articles and should be
as easy (or easier) to con-

A Fun-Station!

struct and to get operation-
al.

For those unfamiliar with
my earlier articles, this
series of articles focuses on
simple, easy-to-construct,
easy-to-operate gear with
all parts available from
local Radio Shack outlets.
Size and appearance of the
vfo match the transmitter
and receiver to provide a
nice looking station pack-
age.

Of utmost importance is
the fact that no modifica-
tions have to be made to
the Fun-Mitter to use the
vfo. It simply plugs in where
the crystal was (unless Copi
was installed). This allows
for either crystal or vfo
operation of the Fun-Mitter
Also, it can be constructed
for either 40 or 80 meters It
provides about 70 kHz of
coverage on 40 meters and
about 50 kHz on 80.

The Circuit

The vfo should be the
most goof -proof of all three
pieces of gear as evidenced
by the schematic of Fig. 1.
The basic frequency-deter-
mfning portion of the vfo is
identical to the vfo of the

12 ?3Magazine • February J982

Internal view of vfo.

Fun-Ceiver. This allows for
ease of understanding and
construction as well as simi-
lar frequency range.

Before I began this series,
I developed a set of guide-
lines for the items to be de-
signed. Based on this crite-
rion of setting goals in ad-
vance. ! developed the fol-
lowing goals for the simple

vfo.

• Good performance [no
chirp, minimal draft, clean
waveform)

• Simple construction [PC
board use, less than four
hours total build time, mini-
mum parts count}

• Cost — less than $20 with
new parts

• Minimal modification to
the Fun-Mitter

• Full output from the Purr-
Mi tter

• No variable capacitors or
inductors

The final version of the
vfo meets the above goals.

Only three transistors are
used in the vfo, one as the
oscillator (Q1), one as a
class-A amplifier (Q2X and
one as an emitter-follower
buffer [Q3]- This final ver-
sion of the vfo went
through three revisions
from the original form. This
was necessary to maintain
good performance while
still keeping things simple.
The original design includ-
ed only two transistors, but
at times chirp was detected

on the transmitted signal
The main advantage of the
circuit of Fig. 1 is that only
one tuned circuit is used
(LI). This means modifying
only one inductor!

Q1 operates as a parallel-
tuned Colpitts oscillator
with LI. CRl, CR2, Cr C2,
and C3 being the frequen-
c y-d etermining compo-
nents. The oscillator is
tuned by varying the volt-
age at the junction of the
two diodes. This, in turn,
varies the capacitance of
the diodes which varies the
frequency of the oscillator.
LI is a modified Radio
Shack 10-|iH rf choke It is
modified, as described lat-
er, to provide the needed
inductance. The last few

Front view of the completed Variable Fun-O^cittator.

turns of the modified choke
are spread out over the
choke body to provide an
easy means of setting the
oscillator frequency.

As mentioned in the re-
ceiver article, the capaci-
tors needed to build a sta-
ble vfo are not ea<;ify found
at Radio Shack. NPO-type
capacitors from a large va-
riety pack again are used in
parallel and series combi-
nations to obtain the need-
ed capacitance for CI, C2,
and C3. Silver-mica or poly-
styrene capacitors will give
even better results.

Output from Q1 is taken
through a coupling capaci-

tor, C4. This capacitor
should be kept as small as
possible to isolate the oscil-
lator from toad variations
which can cause chirp. The
capacitor is attached to the
next stage, Q2, a class-A
amplifier. This amplifier
raises the level of the signal
to the level needed to drive
the Fun-Mitter.

Q2 is direct-coupled to
the final stage, Q3, an emit*
ter follower. This stage pro-
vides excellent isolation be-
tween the oscillator and the
transmitter as well as pro-
viding an impedance match
between the two. Without
Q3, as in the original design,

Llj

« J I 1 J 1^

f — 1 /A At

C«2

*tav rro fni

3900

itl03
220

»00^H

C114

iff

f»04

4»

F\^ 1, Schematic of vfo.

73 Magazine • February, 1982 13

*kZV (TO Stl

TO L

EXT

CR3

PC layout for vfo.

PC boards for the vfo are avaifable from the author for S7
ppd. PC boards for the previous articles also are available as
follows: FunMltter— S7 ppd; Fun>Cftiv0r— $7 ppd; Filter'—
$3,50 ppd*

Parts List

Radio Shack

Designator

Value

Part Number

200 pF NPO (approx.J

272 801

C2.C3

4?0pFNPO

272«I1

10 pF (use two 4,7 in

para 1 lei)

2-272120

C5. C6, C9

0-1 mF

272-135

C7.C8

0.01 hF

272-131

CR1 CR4

1N914

On 80 meters, for CR1 and
CR2, use two 1N9145 in
paral el for each (piggybacH)

276-1122

J1-J3

phono jack

274-346

eOm: Two 273-101 inductors
in series: one with no turns
removed, one with 10 turns

removed

40m: 10 turns removed from

273-101 inductor.

For both 80 and 40 m the

last 3 turns of the modified

inductor should be spread

out over rest of the form

100->iH inductor

273*102

FET

276-2035

Q2. Q3

RS2033

276-2033

100k, 1/4-W

27V1347

10k. 1/4-W

271 -1335

4Jk, 1/4-W

271-1330

R4R6

470Q. 1/4^W

271-1317

Not or> PC

board:

Lfixt

lOO-^H inductor

273-102

, R101

agk. 1/4-W

271^1329

R102

10k linear pot

271-1721

R103

220Q, 1/4'W

271 1313

R104,

R105

Ik. 1/4-W

271-1321

SPST switch

275-612

case

270-251

knob

274-392

TO JZ
tOUTl

Component location.

the vfo is not stable when
the transmitter is keyed.

CR4 is used to shift the
frequency of the vfo when
the transmitter is not in use
and you are Mstening to the
receiver. It does this by
changing the voltage at the
junction of CRl and CR2,
which shifts the oscillator
frequency. Without this
feature, the vfo signal
would appear on the listen*
ing frequency and make lis-
tening impossible!

Construction

The construction of the
vfo is Intended to be goof-
proof. It is built on a 2 ^/4''x
3" single-sided board just as
the transmitter and receiver
were It cannot be overem-
phasized that the circuit
should be built on a PC
board. Nearly all of the
problems that readers had
in building the previous two
pieces of gear were due to
breadboard or point-to-
point construction. If you
are an inexperienced home-
brewer, it is fairly easy to
make mistakes when wiring
the circuit apart from a
printed circuit board.

I built my vfo in an enclo-
sure that matches the en-
closures used for both the
transmitter and receiver.
Also, the front-panel layout
was made compatible to
enhance the appearance of
the gear.

As can be seen in the
photographs, the tuning

potentiometer (R7) is
mounted on the front
panel The associated re-
sistors and inductor (R6, R8,
L3) are also mounted on this
potentiometer, and wires
run from there to the appro-
priate circuit points.

The rear panel contains
three jacks. One is for
the vfo output signal, and
one is for the vfo offset. The
connection between the
vfo and transmitter should
be made with coaxial cable
[RC-174or RC'58)

Operation

The vfo is best operated
with a battery rather than
an ac supply. This elimi-
nates any possibility of ac
hum on the transmitted sig-
nal. It also helps improve
frequency stability Two
6-volt lantern batteries m
series will power the vfo for
a long period of time. If the
Fun-Mitter is powered by
batteries, the needed 12
volts can be tapped from
those batteries.

Tuning and operation are
very easy: Only one adjust-
ment needs to be made-
setting the vfo on frequen-
cy. This is accomplished in
the same manner as was
done in the receiver. Using
a separate receiver, listen
on the frequency you want
the low end of the vfo to be
set on (for example, 7100
kHz], Drape a length of wire
near the vfo and attach the
other end to the receiver

14 73 Magazine • February, 1982

antenna input. With the vfo
on and warmed up, slowly
spread or compress the last
few turns of LI until the vfo
signal is heard in the receiv-
er. This adjustment should
be done with the tuning po-
tentiometer (R7) fully
counterclockwise. Finally,
verify that the vfo covers
approximately 70 kHz if
built for 40 meters and 50
kHz if built for 80. That's all
there is to the adjustment.

To operate the vfo, two
connections need to be
made— one to the transmit-
ter crystal socket and one
from the vfo offset input to
J 3 of the Fun-Mitter. (This
jack was added to provide
receiver mute operation for
the Fun-Ceiver.)

If Copt w^^ rtot included
in the Fun-Mitter, then the
vfo signal can be applied di-
rectly to the crystal socket
terminals (see Fig, 2), If Cgp^
was included, remove its
connection and connect
that terminal of the crystal

socket to ground. An in-
spection of the Fun-Mitter
schematic will reveal that
even this step is not neces-
sary if a method can be de-
rived to connect the shield
of the vfo cable to ground
of the Fun-Mitter, Alterna-
tives such as a rear-panel
phono connector on the
Fun-Mitter also can be used.
A plug can be made easily
from two Vi'' to Va'' lengths
of #12 gauge copper wire.
Solder the vfo signal and
ground leads to these wires
and plug them into the ap-
propriate crystal socket
pins.

Once the vfo is plugged
in and turned on, verify that
the transmitter operates as
it did before. With the vfo
in use and all connections
in place, the vfo signal
should be heard only when
the transmitter is in the
transmit mode (due to the
vfo offset feature). Zero-
beat the vfo with the trans-
mitter in the transmit posi-

TO y 3 "

-®-<

JACK I
I

J3 i

€) I

+ 24V

CRYSTAL
SOCKET

H^iJA i^msm

fig, 2. Connections between vfo and Fun-Mitter

tion and the key down. Re-
member that when using a
direct-conversion receiver,
you must zero-beat the cor-
rect side of the signal you
are listening to.

Crystal operation still
can be used by simply re-
moving the vfo leads and
plugging the crystal back
in.

It should be possible to
use the vfo with low-power
solid-state transmitters
other than the Fun-Mitter,
However, modifications
may be necessary to the

transmitter if the oscillator
is not configured as in the
Fun-Mitter.

Conclusion

The vfo should be simple

to build and goof-proof in
its operation. Many more
contacts now should be
possible due to the ability
to move to the frequency
the other station is on. This
series will be continuing in
the months to come with
additional goof-proof proj-
ects. Meanwhile, enjoy the
Variable Fun Oscillator! ■

THE RTTY ANSWER

IBLFSK-500

T HRtSl^LEt

plot f 1 ti

1 ]« I orr

X t % \ %

iHk fSK-iOOO .

MAlti;

nrjuirt

LIMIT

mPUT tlvtL

SW^Cl

WIDE

^UT0i>1 ^n t .

(Air i OFf I LINt

TMRtbltOLD

MtK

frlV 6io

FSK

LtjLAL

Sl-Ad

THINKING OF RTTY??
APPLE . . . TRS . . . HEATH , . . DEDICATED SYSTEM? SOFTWARE?
INTEBFACE? PERFORMANCE? PRICE? We know you have questions
check our answers. Call today for information on our terminal units!

700 TAYCORRD.

fLUMBUS. OHIO 43230
C614) 864-2464

;r charge accepted
immediate delivery

Build this Antennalyzer

you'll need a weekend

Photos by W1GSL

Penn Ciower Wl BC
459 Lowetl Street
Andover MA 0131 0

Photo A. Front view of the dummy toad/wattmeter/rf bridge.
The resistance dial i$B 2-7/4'' diameter plastic skirt attached
to a standard knob.

16 73 Magazine * February, 1982

Here is a weekend proj-
ect that combines two
instruments and an old
technique into a very handy
gadget to have around the
shack. First, it's an 8-to-IO
Watt 52-Ohm dummy load
with a calibrated wattme-
ter: perfect for tuning up
low-power transmitters.
Second, it's also a calibrat-
ed rf resistance bridge
which can make antenna
adjustments a lot easier by
telling you more about the
nature of a mismatch than a
plain swr bridge will The
old technique provides a
nice tie-in between these
two instruments and gives
some benefits besides: The
dummy load is also a resis-
tive power divider that pro-
vides a low-level driving sig-
nal for the rf bridge.

One benefit of this ar-
rangement is that the power
source sees a load which is
essentially independent of
the bridge load. That means
you can load your QRP
transmitter into this instru-
ment put that new antenna

on the bridge output, and
fool around to your heart's
content without risk of
damaging the transmitter or
even detuning its output
stage. In addition, the
power delivered to a 50-
Ohm load is only about 40
mW when the power com-
ing out of the transmitter is
5 Watts. That is a 21 dB
reduction, and it means
that any signal you radiate
while adjusting the antenna
is 3-1/2 S-units less than it
might have been — certainly
a neighborly gesture on to-
day's crowded bands.

Background Theory and
Circuit Description

There is nothing new or

unique about the circuits
described here. Rf resis-
tance bridges have been
around longer than the
more familiar high-power
swr bridges and there are
several examples in recent
publications,^'^ The dummy
load/power divider tech-
nique was described in
Solid State Design for the

HAL Puts MORE Behind The Buttons

45-1200 Baud RTTY
1-100 WPM Morse

72 or 36

Character ^
Lines

2 Page status

Display Indicator

Code

«';*=•* Half

White J^

Characters J^"."

f Unehift ^"iP'"'
I on S

>r / Space

Auto
TXyRX
Control

on Screen I (For Baudot)

Synchronous

Idle
C'Diddle")

Auto All 3 RTTY

Four Internal MarkHold shifts

RTTY Demodulators <Hiflh or Low TonesJ

. High Tones (U.S Standard) LED Tuning Indicators

• Low Tones (lARU Standard) pj!

• 103 Modem (1070/1270 HZ) fWC^™ TMninn Ror

. 202 Modem (1200/2200 HZ) On-Screen Tuning Bar

Ext. Scope Connections

T2100 System:— ^—^

• CT2100 Communications Terminal • RM210G

• KB2100 Keyboard • MSG21I

• Video Monitor "Brag T
« Printer (300Bd Serial ASCI1*MPI*88G)

Audio or

R5232

Data

Transmit

and Receive

With RTTY Loop Devices

Audio Monitor
ut Audio For Either

From Input or Output

verorTape Signals

Interna) Speaker
Plus External Output

Input Audio

From

Receiver or Tape

RIVt2100 Rack Adapter
MSG2100 2000 Character
"Brag Tape" ROM

24 Line Display
2 Pages of 72
Character Lines

-or-
4 Pages of 36
Character Lines
Split Screen
(with KB2100)

CT2100

*^<*™Tw™c«kwi» TMtnin^

CT21AQ

9- TV Monitor

KB2ia0

HAL COMMUNICATIONS CORP
Box 365

Urbana, Illinois 61801
21 7-367-7373

Radio Amateur (ARRL) and
recently used in a trans-
match tuning circuit de-
Scribed in QSTJ

What I hope to empha-
size here is this instrument's
usefulness as a matching
aid, the simple and inexpen-
sive nature of the circuit,
and the fact that the same
circuit can be used as a
dummy load with a built-in
calibrated wattmeter. Ifs
like getting two instruments
for the price of one, and the
final result is a very handy
piece of test gear.

The resistive rf bridge is a
simple modification of the
classic low-power swr
bridge, so before getting
down to circuit details let's
consider swr bridges in gen-
eral for a moment. There
are two main types of
bridges used for measuring
swr, and the most common
type is a high-power han-
dling circuit meant to be
left in the transmission line
for continuous monitoring.
Usually, this type of bridge
requires a minimum of 5
Watts or so driving the load
before the meter readings
are large enough to inter-
pret accurately. This occurs
because the bridge itself is
very loosely coupled to the
transmission line, typically
through a few picofarads or
several inches of wire run-
ning parallel to the center
conductor of the main line.

The other type of bridge
is inherently a low-power in-
strument. The driving signal
runs right through the resis-
tive elements which make
up the bridge, so the bridge
itself must be able to ab-
sorb a large fraction of the
input power. The resistive
bridge doesn't find much
use in amateur circles be-
cause it requires only a
Watt or less of drive and
can't be left permanently in
the line; it's strictly an
occasional-use test instru-
ment

There is nothing wrong
with continuous swr moni-

18 73 Magazine • February, 1982

toring. After all, the familiar
deflections of the high-
power monitor do give a
constant verification that
the transmitter is tuned and
the antenna connected. The
low-power test instrument
described here has some
advantages over the usual
swr bridge, though, espe-
cially for initial antenna ad-
justments, because it tells
you more than just the mag-
nitude of a mismatch.

Swr can be defined sever-
al ways, and one is the ratio
of a load impedance to the
transmission line's charac-
teristic impedance (which is
almost always near 50
Ohms in current amateur
usage). For example, to
cause a 3:1 swr, a 50Ohm
cable could be terminated
with either 150 or 16.6
Ohms. These are purely re-
sistive loads, but there is
also an infinite number of
reactive loads which would
give the same 3:1 swr, and a
common swr bridge can't
tell the difference between
any of them. You can build
a bridge to measure both
the reactance and resis-
tance present in a load/'^'*
but such bridges tend to be
too complex for my taste
and requirements.

When matching a load to
a 50-Ohm line, I generally
have two questions. Is it
resonant, and what's its re-
sistance? If a load is reso-
nant (and that's how I want
all my antennas to be), then
it has no reactive compo-
nent—just resistance. If I
know the value of that resis-
tance, then I know the swr
and whether I need more or
less resistance to get a
match, rll give an example
at the end of the article, but
right now let's look at the
schematic shown in Fig. 1.

There really isn't much to
the circuit diagram. The in-
put signal is terminated in a
53-Ohm dummy load con-
structed with a series-paral-
lel resistor assortment. The
voltage development across
the 10-Ohm portion of that

dummy load drives a sim-
ple bridge circuit made up
from a 250-Ohm pot, a
51-Ohm standard resistor,
and the load impedance.
The bridge error signal ap-
pears between the output
connector and the poten-
tiometer arm and is detect-
ed by a germanium diode.
The result is then indicated
by a TOO-uA meter in a volt-
meter circuit.

Bridge operation is
equally straightforward.
When input power is ap-
plied to the instrument, it
develops a voltage across
the 53-Ohm dummy load.
About 1/5 of this voltage
appears across the 10-Ohm
portion of the dummy, and
this is the driving voltage
for the resistance bridge.
Some fraction of this driv-
ing voltage shows up be-
tween the potentiometer
arm and ground, the exact
amount depending, of
course, on the shaft posi-
tion. Similarly, there is
some other fraction of the
bridge driving voltage ap-
pearing across the load ter-
minal, this fraction depend-
ing on the load resistance
connected there.

If there is no load con-
nected, then the entire
source voltage appears
there and well make use of
that fact later to calibrate
the wattmeter portion of
this instrument. If a 51-Ohm
load is connected, then ex-
actly half the source volt-
age will be there. The differ-
ence between the output
voltage and the potentiom-
eter arm voltage is rectified
by the diode and drives the
meter through the sensi-
tivity control, so with the
51-Ohm load the bridge will
show a null when the pot
travel is exactly centered.
Other load resistances will
show nulls at other posi-
tions and the potentiometer
dial may be calibrated by
marking the nulls corre-
sponding to a whole series
of load resistances. In
theory, the bridge should

show nulls for every load re-
sistance between zero and
infinity, but in practice this
doesn't happen because the
potentiometer isn't infinite-
ly adjustable.

The circuit c^n be cali-
brated pretty accurately for
resistances between 5
Ohms and 1 k, with the best
resolution around the
center of the dial at 20 to
150 Ohms, Notice that the
bridge cannot be nulled
completely if the load has a
capacitive or inductive
component since such a
load would introduce a
phase shift between the
bridge source voltage and
the bridge load voltage. As
there is no corresponding
phase shift between the
bridge source voltage and
the potentiometer arm volt-
age, there never will be a
point where the diode volt-
age will be zero and the
meter nulled, Even when
the voltages at each end of
the diode are equal in am-
plitude, the fact that they
are phase-shifted with re-
spect to each other guar-
antees that there will be a
sine wave or error voltage
for the diode to rectify. In
practice this means that un-
less the load is a pure resis-
tance there will not be a
true null but only a partial
dip in the meter reading as
the potentiometer shaft is
turned,

A true rf impedance
bridge would have two null
adjustments: one for rf re-
sistance and one for reac-
tance. With such a bridge
you can completely define
any mismatch, but, as
noted earlier, that's often
unnecessary, especially in
antenna work where the
goal is to tune out reac-
tance by resonating the
antenna. You can always
tell when a load is resonant
with the resistance bridge
because at resonance the
null will be complete. Then
steps can be taken if
necessary to transform the
remaining impedance to
match a 50-Ohm line.

Reader Service far facing page ^fff—

4<DK MAKES 2 METER FM
SIMPLE AND EASY!

KDK INTRODUCES A NEW GENERATION OF 2 METER FM RADIOS.

The sparkfing 2025 A MKII is loaded with new features! East of operatt0n is the design caneept at KDK

KDK VHF FIV1 TRANSCHIVeR

AXQ

IVtS

* -■ ' - ^ ^fi

FAA-sass

-.6 +,B

OiA^

WRTTE

VOL-^SOL

^/IQDE

IVIEMOFIV

fsAJC

SPECIAL!

WINTER SALE!

Includes:

Touch Tone® Mike (Ready lo Usel

ORDER NOW DIRECT

eatyres such as ten ctianngE memory in two banks of ffve each, a
kOlid 25 watts of power, full MARS and CAP coverage from 143,000 Mhz
to 148.995 Mhz, plus built in memory retention for up to one year , . .
ind much, much more makes this the radio of the y^ar. If you have been
ivaiting to move up to a new model, or have wished fiir a radio with
'everything".,. KDK has it!

#The ten channel memory is easily addressable and you have two banks
rf five channels each. You can even use both banks at once for odd splits.

•Standard 600 hz shift up or down. Band scan or memory scan. Memory
Ecan is easy. There is atso band scan with upper and lower limits you can

choose yourself!

•Built in nicads for the memory retention which has drain in nano-amps,
lot mitri amps. The internal battery will hold the memory for up to one
fear! No other radio offers you this feature.

• Fast and easy dfaling. Full solid state dtaling and you can choose from
he front panel either a fast or slow dial rate*

• No reiays are used, only solid state switching. This eliminates a trouble
pot many radios encounter.

• KDK h^ also eliminated another trouble spot by compfetely hand
viring each radio. No internal plugs to become intermittant and no wire
vraps either, juit good solid wiring.

DRDER NOW DIRECT
I CALL TOLL FREE

800-251-4141

This number for ORDERS ONLY!
Mall Order - COD - Bank Cards

'^*itm cn#^

HOURS - 9:00 * 5:00 CST Monday - Saturday
Phone (&tS) 865 7949
Tetex 80-8327

• KDK gives you one of the hottest receivers you can find. By using UHF
(not VHF) dual gate MOS-FETs with electronic auto tuning for the RF
amplifier and the first mixer, you have a combination of ultra sensitivity
and maximum quietness.

•The audio output stage in the 2025A Mk II uses an integrated circuit
which has internal protection against over-voltage and shorted output
conditions. Plus it is a high audio output chip — just what you need in a
noisy mobile situation.

• The transmitter uses direct VCD varicep modulation for true FM. Your
transmitted audio sounds as it should; crisp, clear and naturaf.

•The power output stage of the 2025A Mk II will not break down even
with an infinite VSWR load, and uses heavy duty solid state antenna
switching with a four stage low pa^ fitter. All this gives you an exception-
ally clean, spur free output.

•KDK has included an adjustable sub audible tone circuit which can also
be used for CTCSS or tone burst on transmit. Again, more features!

•Size is 2 7/10" high - 7 1/8" wide - 3 t/2" deep.

•You can switch from 25 watts to 3 watte low power.

•And, of course, the DC cable is included along with the microphone
and mobile mounting bracket.

Write for brochure - Dealer inquiries invited!

Warranty information available at yotjr dealer
Company reserves the right to change specifications without nottce.

Exclusive US Distributor - Dealers Welcome!

ORDER DIRECT

OR AT VOUR DEALER!
Distributed by;

KDK DISTRrBUTING COJNa

617 SOUTH GALLATIN ROAD ~ MAOISON.TN 37115

Phone (61 S)865-7949

POWER >— ^

LOAD

SEE TEXT

MET

exER

Fig, t. Schematic diagram of dummy load/wattmeter/rf

bridge. R1 is chosen as necessary to calibrate the wattmeter

This same bridge circuit
can be used to measure the
power delivered to the
dummy load by the trans-
mitter, A glance at the
schematic will assure yo^J
that with no load connected
to the bridge and the resis-
tance dial set to zero Ohms,
the voltmeter circuit will in-
dicate the rf voltage across
the 10-Ohm portion of the
dummy load. Knowing that
voltage, we can easily cal-
culate the voltage across
the whole dummy resis-
tance, and knowing that, we
can calculate the power
there from P = V2/R. The
calibration can be accom-
plished using only a dc volt-
meter and will be described
shortly.

Construction

A lot of articles begin
their construction descrip-
tion with the assurance that
"the layout is completely
noncritical/' That is certain-
ly not true here, but "criti-
cal" is also too strong of a
word, so let me just caution
you to be careful with lay-
out. There are three main
areas that can cause trou-
ble.

First, it's best to arrange
the dummy load portion of
the circuit so that current
flowing in the ground path
from the bottom of the
dummy load back to the in*
put terminal does not share
any conductor with part of
the bridge circuit. If it does,

20 JSMagazine • February, 1982

then variations in the input
power will shift the null po-
sitions on the resistance
dial. Photo B shows one
way to solve that problem
by bringing the input power
and its ground return to the
dummy resistors on a single
piece of coax, thus avoiding
the temptation to ground
the bottom resistors to
some point on the chassis.

Second, the detector di-
ode should have one end
connected directly to the
output jack. My first few at-
tempts had more compact
physical arrangements with
the diode connected to the
bridge output terminal with
lengths of wire or brass
strips. This always inter-
fered with getting good
deep nulls on both ends of
the resistance range.

Third, the detector
should not be a silicon
diode, since the 0.6-volt
threshold of a silicon diode
will cause the bridge nulls
to be too wide. With a given
load termination there
should be a single, sharp
deep null on the dial, not a
dead zone covering several
degrees of rotation. My col-
lection of diodes is pretty
large, and the best of the lot
turned out to be some ger-
manium 1N34 equivalents I
paid 10^ each for some 15
years ago! Radio Shack's
276-1123 diodes cost the
same today and should
work as well.

The dummy load nomi^
nal value is about 51 Ohms
with the circuit shown. I
used an assortment of resis-
tors from the junk box, so
feel free to substitute val-
ues, but do observe a few
simple rules. Wire-wound
resistors are definitely out
because they look like coils
at radio frequencies. Also,
stick with carbon resistors
having values less than Ik.
When paralleling resistors,
try to have them all of the
same value so they dissi-
pate equal amounts of pow-
er. Keep the leads short and
the wiring direct; this keeps
the dummy load looking re-
sistive at the higher fre-
quencies and prevents stray
coupling which might inter-
fere with the bridge nulls.

The rest of the physical
arrangement is pretty clear
from the photographs with
the exception of the bridge
potentiometer mounting. A
similar bridge is described
in WeSAI's 1962 Radio
Handbook^ and the author
there cautions that stray ca-
pacitive coupling between
the potentiometer resistive
element and ground can
cause frequency sensitive
errors in calibration.

The suggestion made
there, and followed here, is
to cut a large hole in the
box (say, 1-1/2" in diameter)
and mount the pot in the
center of this open space
using a piece of insulating
plastic, bakelite sheet, or
unplated circuit board for
support. This insulates the
pot body from ground and
thereby greatly reduces the
capacitive coupling be-
tween the pot resistive ele-
ment and ground. It seemed
like a good suggestion so I
followed it. I can't strictly
say it is necessary because I
didn't try it the other way,
but it sure can't hurt.

The skirt on the resis-
tance dial covers the hole
from the front of the box. If

you want to use a smaller
knob with a pointer, you
could mount a rectangle of

insulation over the hole
from the front side of the
panel and use that to hold
the pot and the calibration
marks. The actual value of
the bridge potentiometer is
not too critical It should be
at least 50-Ohms so that it
doesn't draw too much
power, and anything over
Ik is probably asking for
trouble with stray capaci-
tance. If you have anything
inside that range, try it
before you buy a new
250-Ohm unit.

The box shown is a cut-
down Bud minibox that
started out as 3"x4"x5^

The 3" height was reduced
to just under 2" because it
fit the hand better, but
there is nothing magic
about these dimensions.
Use anything of roughly the
same size as long as it is
made of metal. You also
will note in the photographs
that BNC connectors are
used instead of the more
common (in amateur cir-
cles, anyway) UHF series. 1
don't run enough power to
require RG-fl, and I find the
smaller quick*connect BNC
connectors more conve-
nient for my home-brew
projects, Naturally, if all of
your antenna cables have
UHF connectors, then you
also should use them on
your bridge.

Calibration

There are two things to
calibrate here: the watt-
meter and the bridge scale.
The meter serves as a null
indicator when using the
bridge, so the wattmeter
calibration can be done
after the bridge has been
checked out*

The bridge dial can be as
simple or fancy as desired
but it should be large
enough to read easily. The
skirt on my dial is 2-1/4" in
diameter You probably will
want to start with a paper
scale and save the fancy
artwork until everything is
working properly.

Assemble a collection of
carbon resistors covering as

many values as possible be-
tween 5 and 1 000 Ohms and
then Qui the leads to about
1" in length. The leads are
bent so the resistors can be
spring loaded into contact
with the bridge output con-
nector. If you have a lot of
spare connectors, you also
could make up a number of
dummy loads with the dif-
ferent resistors similar to
the one shown next to the
bridge in Photo B.

Any layout problems will
be more pronounced at the
higher frequencies, so fire
up a 10-meter rig if you
have one and feed several
Watts of rf into the bridge.

(I've used this instrumefit
only on 10 meters, but it
might work all right up to 6

meters.) With the bridge ex-
cited, check the nulls at
both ends of the range, say,
with a 10-Ohm then a
680-Ohm toad.

Both nulls should be
deep and well defined. If
one isn't as deep as the
other, then there is prob-
ably something wrong with
the physical layout of the
bridge elements. Try mov-
ing things around some or
try another ground routing.
If you followed the layout
shown, then there really
shouldn't be any trouble.
Remember that this is an rf
resistance bridge and with
resistors on the bridge out-
put, the nulls theoretically
should be right down to
zero meter movement In
practice, stray reactances
prevent the nulls from be*
ing perfect but they should
come pretty close to it If
the load does contain some
reactance, there still will be
a dip but it won't be to zero
as previously mentioned.

When you're satisfied
with the basic bridge opera-
tion, make a temporary
scale and mark off the posi-
tions of the nulls due to the
collection of sample resis^
tors. Standard resistor val-
ues aren't nice round num-
bers, but with enough cali-
bration marks you can

Photo fi. Interior of the instrument, showing layout and construction details. The obiect in
the foreground is a dummy load typical of those used during calibration.

make a final scale with lines
at 5, 10, 20, 30, etc.. Ohms
as shown on the front panel
in Photo A,

The wattmeter scale can
be calibrated easily using a
dc power supply and a
good dc voltmeter. Remem-
ber that the wattmeter is ac-
tually reading the rf voltage
across the lOOhm portion
of the dummy load when
there is no bridge load and
the bridge pot is set to zero
Ohms, Under these condi-
tions, the 00027-uF cou-
pling capacitor [that's not a
critical value — anything
from 0 001 to 0,05 will work
as well) will charge to the
peak value of the rf sine
wave.

Since the peak value of a
sine wave is 1 .41 4 times the
rms value, it is easy to cal-
culate a dc value which,
when fed into the instru*
ment, will read the same on
the meter as some given rf
power. A conversion chart
for the 53-Ohm dummy
load is given in Table 1
along with the equation
necessary to calculate your
own equivalents should you

use some other combina-
tion of resistors. Since I was
interested in converting CB
sets, I calibrated my watt-
meter for a full-scale
reading of 5 Watts, even
though the resistors can
handle 10 Watts for short
periods. To make the
5- Watt calibration, feed a
measured 22.9 volts into
the unit, turn the sensitivity
control ail the way down
(maximum resistance), and
select a value for R1 that
gives a full-scale meter
reading.

Now comes the hardest

part: making the meter
face. I don't like conversion
charts so I made a whole
new face for my meter. It's
not as difficult as you might
think, but it does require a
steady pair of hands.

Open the meter, remove
the two screws holding the
faceplate in place, and
remove the faceplate while
taking care not to damage
the meter pointer Glue a
clean piece of white paper
over the old faceplate using
paper paste and not liquid
white glue (which tends to

dampen the paper so much
that it wrinkles). Be sure to
cover the faceplate evenly
with paste so the paper
won't have a chance to
wrinkle. The pointer travels
close enough to the face-
plate that it can get stuck
on wrinkles,

When the paste is dry,
use a sharp knife to trim off
the excess paper, and a pin
to punch through the screw
holes. Now a drawing set
with an ink compass can be
used to draw in a nice arc
for the baseline of the new
scale. Remount the face-
plate, center the meter zero
adjustment, and make a
light pencil mark under the
pointer tip to define the
zero rest position. Reapply
the 22,9 volts and make
another pencil mark to spot
the 5-Watt full-scale posi-
tion. Now go down the list
in Table 1 and mark off
each intermediate point,
checking occasionally that
all of the poinb are repeat-
able and properly marked.

Finally, remove the face-
plate again and finish off
the scale graduations with

73 Magazine • Fabruary, 1982 21

TAP POSITION
SeT &1 FACtOftT

TR^NSMrSSlON

VERTICAL AAlKitTOR

OF AQ4UStJlSL£ LEffGTM

LOAC^ING COIL

'"''"=*"'f='>'^'^ ^ V j MATCHING COII-

LINE TO RtQ ^ 1 f

J_ CAPAtiTlVE COUPLIMO

seao^asopFi TO sflouNG

77////////////////

aRDU»iD P'lANE - THE CAR ROOF

fig. 2. Shortened haded verticai a CB mag-mount whip.

ink or dry transfers using
the light pencil marks as a
guide. With a little care, the
results can be pretty profes-
sional. One real bonus of
this technique is that the
calibration is correct with
the particular diode, resis-
tors, and meter actually
used, since the whole cir-
cuit is calibrated at once.
That's important because
the diode is not a perfect
rectifier and the meter
scale will be influenced
slightly by the characteris-
tics of the particular diode
used*

An Application Example

The most obvious use for

Input Power

Dc Voltage

Watts

Equivalent

5.0

22.90

4.0

20.49

3.0

17.74

2.0

14.49

1.0

10.24

0.5

7.24

0.4

6.48

0.3

5.61

0.2

4.58

0.1

3.24

Table 1. Wattmeter calibra-
tion. Input power levels cor-
responding to dc voltage
equivalents. Values are cat-
culated using E = V 2RP,
where P = rf power [in
Wattsl R — total dummy re-
sistance, and £ = ofc input
voltage (where E is peak
value of rf sinewave}. Cau-
tion: With these dc inputs,
the dummy load is dissipat-
ing twice the indicated rf
power, so be careful not to
overheat the resistors.

22 73 Magazine • February. 1982

the rf resistance bridge is in
making matching adjust-
ments to antennas. Some
antennas^ dipoles, for ex-
ample, are easy to adjust
with an swr bridge since
their feedpoint impedance
at resonance is already
close to the typical cable
impedance. When a dipole
is fed with either 52- or
73-Ohm coax, its swr at
resonance is bound to drop
to somthing like 1.5:1. This
isn't true with shortened an-
tennas such as mobile
whips since their feed im-
pedance may be only a few
Ohms.

There are two adjust-
ments necessary to get a
low swr with such an anten-
na: one for resonance and
one for impedance match-
ing. Making these two ad-
justments With only an swr
bridge can be very difficult
because a low swr will re-
sult only when both settings
are correct. With a re-
sistance bridge, the adjust-
ment is much easier.

Consider the antenna
shown in Fig. 2, a magneti-
cally-mounted, base-load-
ed CB whip. The antenna
really has two adjustment
points, although the tapped
loading coii is normally ad-
justed and sealed at the fac-
tory and all that is neces-
sary for 27-MHz operation
is a slight height adjust-
ment. Putting this antenna
to use on 10 meters or using
a different length whip sec-
tion may change things
enough that a low swr can-

not be achieved without a
change to the coil size or
tap position.

For example, I am using
one of these antennas on
the roof of my house as a
loaded ground plane. The
eight 1 /4A radials laid out on
the roof do not provide the
same type of ground return
as the roof of an automo-
bile. In addition, a 5' whip is
being used as a radiating
element in place of the orig-
inal 3' length. This longer
length lets me use a smaller
loading coil with lower
losses I built this test irv
strument partly because of
the difficulty I was having
trying to tune this antenna
with only an swr meter and
grid dipper.

Adjusting such an anten-
na is a lot simpler with the rf
resistance bridge, but first
the bridge must somehow
be connected to the base of
the antenna, ft would be
nice to locate the bridge
physically at the base of the
antenna but this isn't
always practical For one
thing, the bulk of the oper-
ator's body would probably
upset the antenna tuning If
the bridge is connected to
the antenna through a
length of coaxial cable then
that cable length must be
chosen carefully because
the impedance seen look-
ing into a transmission line
depends on three things:
the line impedance, the
load impedance, and the
line length.

Luckily, it happens tiiat a

section of transmission line
which is some multiple of a
half wavelength in length
will have an input imped-
ance almost exactly equal
to its toad impedance. Us-
ing such a line makes it pos-
sible for the bridge to be
located at some convenient
position and still indicate
the antenna base imped-
ance At 28 5 MHz, a half
wavelength in free space is
16' 5" and in coaxial cable it
will be about 2/3 of that or

If you have a section of

cable this length, it is easy
to check its electrical
length with the bridge. First
put a 10-Ohm resistor dh
rectly on the bridge and
check for the null at 10
Ohms Then insert the cable
section between the bridge
and resistor and see that the
bridge still reads a resistive
10 Ohms, If it is a little off,
as indicated by an incom-
plete null somewhere near
10 Ohms on the dial, you
may want to change the
transmitter frequency a bit
to adjust the operating
wavelength to the line's
physical length.

lust for fun, you might
try a quarter wavelength of
cable and verify that it
transforms the 10 Ohms in-
to 270 (52'Ohm cable). In
fact, you might get out a
good article on transmis-
sion-line matching sections
and try a number of things
with different loads and
line lengths — it's fun and
really brings that dry old
theory to life.

With the antenna fed
through some multiple of a
half wavelength of cable,
the radiator length can be
adjusted for resonance as
indicated by a complete
null of the meter reading.
The resistance indicated at
resonance is the feedpoint
impedance of the antenna,
and the ratio of that imped-
ance to 52 Ohms is the swr
on the cable — assuming
you're using 52-Ohm cable.
If the swr is more than 21
(antenna impedance great-
er than 100 or less than 25
Ohms), then you may want
to change the coil tap posi-
tion. It probably is easier to
change the inductance be-
low the tap by squeezing or
separating the coil turns
there slightly than it is to
unsolder and move the tap
itself. These adjustments
can be pretty fine and you
probably won't end up
changing the coil size by a
whole turn's worth anyway.

With the inductance
changed, look for the new
null on the bridge and, once
again, adjust the antenna

height until the feedpoint
impedance is pure resis-
tance. Depending on
whether that resistance is
closer or further from the
52-Ohm target, you now
know in what direction the
coil must be altered to ef-
fect an acceptable match.

Conclusion

Of course, there are
many other tuning applica-
tions for this instrument
besides CB antenna conver-
sions. You will find it more
useful than an swr bridge
for any application which
requires both resonating a
load and transforming its
impedance. As a bonus, you
can use it to measure swr
when the load impedance is
mostly resistive. The inter-
nal dummy load lets you
adjust and modify antennas
without danger to your
transmitter and without
putting a big signal on the
ait YouH also find that the
dummy load and calibrated

wattmeter are a valuable
QRP tune-up aid Last, but
not least, you can develop a
real understanding of trans-
mission-line matching tech-
niques by using the bridge
to verify some of the theory
you read when studying for
your ticket] ■

Referdnc«8

1 a KISnet WB6BIH, ^'Home-
Brew Rf Impedance Bridge/' 75,
May, 1980.

2. J. Sevick, "Simple Rf
Bridges/' OST, April, 1975.

3. W. Vissers, "Tune-up Swiftly,
Silently, and Safely," OST,
December, 1979.

4. R. Luetzow. "Build an Oper*
ating Impedance Bridge," QST,
November, 1979.

5. R. Hubbs and R Doting, 'Im-
provements to the RX Noise
Bridge/" Ham Radio, February,
1977,

6. J. Hall and J. Kaufmann, "The
Macro-Matcher/' QST, January,
1972,

7. W. Orr, editor. The Radio
Handbook, Editors and Engi-
neers, Ltd.. 1962,

Iowa's Only Icom Dealer

ICOM

G&K Amateur Supply

2920 East 9th St.

Des Moines, Iowa 50316

7:00—5:00 Mon-Fri.
7:00— 1:00 Sat.

Leroy WD0CZO

^ tot

reader:

SHOULD KNOW

What does MBA mean? it stands for Morse-Baudot and ASCIK
What does the M BA Reader do? The RO model (reader only) uses
3 32 character alphanumeric vacuum fluorescent display and
takes cw or tty audio from a receiver or tape recorder and visually
presents it on the display.

The copy moves from right to left across the screen, much like
the Times Square reader board. Is the AEA model MBA Reader
drfferent from other readers? It certainly is! It is the first to give the
user 32 characters of copy (without a CRT), up to five words at one
time. It can copy cw up to 99 wpm and Baudot at 60-67-75 and 1 00
wpm. Speeds in the ASCI! mode are 110 and hand typed 300
baud. The expanded display allows easy copy even during high speed reception.

The AEA model MBA has an exclusive automatic speed tracking feature. If you are copying a signal at
'3-5 wpm and tune to a new signal at 90 wpm, the MBA catches the increased speed without loss of copy.
The MBA Reader allows a visual display of your fist and improves your code proficiency. It is compact
In size, and has an easily read vacuum fluorescent display.

The Reader operates from an external 12 VDC source. This allows for portable/mobile or fixed
operation.

Check the AEA model MBA Reader at your favorite dealer and see all the features in this new
equipment. If your dealer cannot supply you, contact ^^ ^^B ^^

Advanced Electronic Applications, inc. ^^ ^S ^m Brings VOU th0

RO. 80x2160. Lynnwood. WA 98036 Call 206/775-7373 ^^HB^^ Breakthrough!

Prices and specfficaMons subject to change wrthout notice or obligation

uwmnmBsm

S&e List of Advertisers on page f t4

73 Magazine • February J 982 23

*^4ia

WE'RE ROLIN
IN CRYSTALS!

2 Meter Crystals — $3.95 each
(10 or More — 83*50 each)

Quick Delivery

We Stock Crystals For:

Clegg Drak€ Icom

Kenwood Midland Regency

Standard Wilson Yaesu

Lafayette Tempo VHP Eng

(Custom Crystal Orders Accepted.)

Rotin Distributors

P,0* Box 436 Department 7
Dunellen» NJ* 08812

201-469-1219

Precision Cut Land Moblle9 Available

ORZ Wl's, W2's and W3'b...

LOOKING FOR AEA PRODUCTS
IN THE NORTHEAST?

LOOK TO RADIOS UNLIMITED...
NEW JERSEY'S FASTEST GROWING
HAM STORE!

Gel your haifids on AEAs great Iteyers huge stock of hsm gear y and try before

and Isopole antetiftas ai Radfos y nlimited. you buy* Wie don I mean a Itttie off -ihe-aif

You can reach us easily via the Jersey diddling with the keyef *e let you PUT

Tumprke and when you get here you can *T ON THE AIR AND HAVE A QSO.. really

TRY BEFORE YOU BUY at our in store cbeck it out under YOUR kind of operating

opef ating position Yes! Pick oul any AEA conditrons. then decide We know AEA,

keyer, (or any other equipment from our and we knovv you "I I seieci one of these;

MM-1 fwlorsef^atFC^*^ memory keyer with
two micorcomputers and 37 faolastfc fea-
tures including up to 2O0O characters of
memory plus virtually every capability of all

, t he other keyers Strainers fasted below

cad iQi super -tow pnce!

CK 1 Contest Keyer with 500 chafacler
memory, soft message partdioning, auto-
matic serial number, and much, much more.

caif tor super low pncef

MK-1 Morse Keyer with selectable dot &
dash memory, full weighting, calibrated
speed, bug mode and more ._.......,.

call for super- low pnce '
KT-1 Keyer Trainer with all the features of
the MK-taboveand the Mil below. , .

caif for super-tow pnce ^

iyiT'1 Morse Trainer tor pul ling up that code
speed the easy way with automatic speed
increase, hve letter or random word length

and more. more, more , _ . , , . , , , ,

caff for sapertow price ^

it»v

THE EXCITING ISOPOLES THAT ARE
BOOMING OUT THOSE INCREDIBLE
VHF SIGNALS WITH MAXIMUM GAIN
ATTAINABLE, ZERO
DEGREE RADIATION
ANGLE AND 1.4:1
SWR ACROSS THE
ENTIRE BAND! ^^

Jsopoie 144
Isopole 220
isopole 144 jumof
Isopoie 2:20 juniof

C3it tor

super-toy^

price*

Find them all at Radios Unlimited, plus a huge collection ot new gear from alt
major manutaeiurers-.a big selectior^ of used eduipment bargains, all youll ever
need in books, accessories, operating aids, coax, connectors and parts plus a
modem sen/ice department dedicated to keeping you on the air It's like a perpetual
flea market! For directions, call
(201)469-4599

FIND AEA
AT

1760 EASTON AVENUE, SOMERSET. NJ 08873 • (201)489-4599

TOWERS

Up to 200 foot
Installed

24 73 Magazine • February, 1982

PeaiSer Sfvit* tOt tKing p»g» •'S"

^M^T'

^ i] ^

y^m

[jff

^yjiXiYi^^B

IS!

W^tM I

^^^^^^1

•

&5PG

# ###

K «5>

w .%'**

*i«im%%

r.Mt '^^

SUPERIOR
COMMERCIAL GRADE
2-METER FM TRANSCEIVER

TOUCH-TONE'
PAD KIT INCLUDED

COMPARE THESE FEATURES WITH ANY UNIT AT ANY PRICE

8 MHZ FREQUENCY COVERAGE, INCLUDING CAP/MARS BUILT IN: Re-
ceive and tiaAsmrt 1 42.QO0 to 1 49 995 M Hz m selectaOte steps ot 5 of 1 0 kHz.

.it J ' •

out by a

• SIZE Ur[-e .evabi^ OnfyS^k' bv2*^" bv9f^". COMf - l

• MICROCOMPUTER CONTROL: All frequefKiy control is
microcompiiter

■ MUSICAL TONE ACCOMPANtES KEYBOARD ENTRIES: When a key is
pressed, a bnet musical tone mdicaies posrtive erttry into the fntcrocomptiter
COMPARE'

• PUSHBUTTON FREQUENCY CONTROL FROM MICROPHONE OR
PANEL: Frequency is seiected by buttons on the froni pane5 or microphone,

• a CHANNEL MEMORY: Each memory channel is reprogrammaWeand stores
the frequency and offset. Memory is backed up by a NfCAD battery when
power is removed

- INSTANT MEMORY 1 RECALL By pressing a button on the microphone or
front panel, memory channel t may be accessed immediately

• MEMORY SCAN: Memofy channels may be contrnuously scanned for quick
bcatron of a busy or vacant frequency

< PROGRAMMASLE BAND SCAN: Any section of tt^ band may be scanned in
steps of 5 Of 10 kHz Scan limits am easily reprogfamiiifld

- DJSCRiMlNATOR SCAN CONTROL (AZDEN EXCLUSIVE PATENT): ine
scanner slops t^ sensing the channeJ center, $o the u^^itafways tands on the
COrf«ct frequency CC^PARP ttiis with other units \hat claim to scan ir\ S-kHz
slepsi

• THREE SCAN MOOES WITH AUTO RESUME: "Sampling" mode pauses at
tHJsy channels, tnen resumes 'Busy mode stops ai a busy ct^nnel then
resumes shcniy after frequency clears "Vacant" mode Stops at a vacant
channel and resumes when signal appeara. If desired auto resume may be
prevented by pressing one button ^PARE"

■ REMOTABLE HEAD: The control head may be located as muchas 15 feet
away from the main unit using the optional connecting cabia COMPARE!

• PL TONE OSCtLLATQR BUILT IN: Frequency is adjustable to access PL
fBpeater&

-MtCROPHONE VOLUME/FREQ. CONTROL: Both functions fimy be
adjusted from either tne micfopnone or front panel

• NON-STANDARD OFFMTS: Three accessory offsets can be obtacr^ed for
GAP/MARS Of un jsuai rei:«aief spJita CAP and A^r Force MARS splits are
eUlLTIN!

• 25 WATTS OUTPUT: Also 5 watts low power to conserve Daitenes in portabie
usa

• GREEN FREQUENCY DISPLAY; Frequency numerals are green LEDs iof
supenof visibility

» RECEIVER OFFS^: A Channel lock switch allows monitoring of the repeater
input frequency, CDMPARS

• SUPERIOR RECEIVER: Sensitivity is better than 0.28 uV for20-dB quieting
and 0.1 9 uV lor 1 2-da SI NAD, The squelch sensitivity is superb, requiring less
than OT uV to open, The receiver audio circuits are designed for maximum
inleiisgibHity and lidefity. nOMPARii-r

• ILLUMINATED KEYBOARD: Keyboaid bscklightir>g attows it Id be seen at
night

• TRUE FM. NOT PHASE MODULATION: Transmitled audio quality is opK
tiffiized by the same high standard of design and construction as is found in the
iBOeivef. vtm micrpphcr^e ampiilier and compression circuits Offefintelligibiliiy
secorxJ to none

- OTHER FEATURES! tDynamic microphortfetbuJii- in speaker, n^obife mounting
bracket, external renrote speaker Jack {head and radto) and much, much mora
AH cords, plugs, lusesi. microphone hanger etc fncluded Weight: 6 lbs,

• ACCESSORIES: CSECK ! 5-foot remote cabte. CS-6R e-amp ac power
suppiy CS'AS remofe speaker: CS-TTK touchtone* microphone kit
(wired and tested).

AMATEUR-WHOLESALE ELECTRONICS ORDER now toll free

8317 aw. 1 29tri Terrace. Miami, Florida 33i 76
Totephone {305) 233-3631 • Telex: 80-3356
HOURS: 9-5 Monday thai Friday
• US. DISTRIBUTOR' DEALER INQUIRIES INVITED

L *.1

m 800-327-3102

CREDIT CARD HOLDERS MAY USE OUR TOLL FREE ORDERING NUMBER

Arnai Cook N9AKX

1591 5. Lane Ave.. Apt. 2JC

/acksonv/l/e ft 32210

Police Freqs for the TR-2400

a sleepless night for the mod squad

I do not need to extol the
bounty of convenience
and luxury Kenwood's new
TR-2400 hand-held 2-meter
transceiver has brought to
VHF enthusiasts. Most
hams, no doubt, have seen
or read of its features— no-
tably 10 channels of pro-
grammable memory and its
ability to scan these mem-
ories, stopping on active or
inactive channels. Being
strictly a VHF enthusiast,
my mind began to drift
when my TR-2400 arrived to
what the next advance in ra-
dio/scanner technology
would bring forth. It didn't
take very long to imagine
the first tri-band program-
mable hand-held scanner

4i.

I 1 I v^«

< COLLECTOR

fig, 1. Vco location,
26 73 Magazine * February. 1982

After alL the TR-2400 had
broken the ground, at least
in a single-band version.

I also began to ponder
the possibilities of convert*
ing the TR-2400 to the "ac-
tion band/' One sleepless
night was spent tracing the
schematic lines and deci-
phering its method of oper-
ation. I would like to thank
Trio-Kenwood Corporation
for their practice of supply-
ing block diagrams and full
schematics with their prod-
ucts. 1 wish all manufactur-
ers would make it a policy
to do the same with every
unit This ham, for one, dis-
trusts "black boxes."

Several possibilities
emerged to modify the
TR-2400 so that reception in

the 154- to 158-MHz range
would be possible. Three of
them will be outlined here,
from simple to complex.
The simplest of these is cur*
rently working in my rig
The second requires moder-
ate circuit modification,
but may not work depend-
ing on the range of the vco.
The third method requires
additional parts and good

instruments to adjust but is
sound in theory. I present
these here in hope that
someone else will follow
my theories, try to imple-
ment them, and report their
results. I cannot because 1
begin Navy pilot training at
Pensacola, Florida, within
two weeks of writing this
draft and don't have the
time!

Theory in Operation

The operation of the
TR'2400 is fairly straight-
forward as frequency syn-
thesizers go. Referring to
your owner's manual (pages
14 and 15) with the follow-
ing description may be
helpful, but not necessary,
to follow the principle of
the synthesizer.

Transistors Q7 and Q8
and associated power sup-
ply pass transistors Q2 and
Q3, respectively, form a
complementary electronic
switch — i.e., when Q2 is ON
during receive, Q3 is OFF,
and vice versa during trans-
mit Q2 controls the fixed
frequency receive beat os-
cillator/tripler (XI, Q1), Q3

controls the transmit beat
oscillator/tripler (X2, Q4).
During transmit positive
bias on the base of Q7
causes it to conduct to
ground and turn off Q2 and
Q8, which turns on Q3 and
Q4.

The output of Q4 (138.5
MHz) and the VHF voltage
controlled oscillator [vco,
QIO) are mixed, filtered,
and amplified by Q5 and
Q6 This forms a downcon-
verter, much like the i-f sys-
tem when in a receiver. As
shown on the block dia-
gram in the manual, the
output of Q6 is always be-
tween 5,5 and 9.5 MHz for
2-meter operation (144.0 —
138.5 = 5.5 MHz). The full
range is 5 4 MHz to 9,995
MHz, In receive mode, pass
transistor Q2 activates Ql
(127.8 MHz) and D3. The
output of Ql is lower than
Q4 by 10.7 MHz, which is
the i-f frequency in order
to keep the output of Q6
between 5,5 and 9,5 MHz,
the vco must drop its fre-
quency by 10.7 MHz, too.
Most of this drop is ac-
complished by D3 bypass
ing C27 when forward bi-

ased, effectively increasing
the value of C26 (the value
of two capacitors in series is
lower than the smallest
value; bypassing one of
them therefore increases
the value of capacitance in
the circuit). This lowers the
vco frequency by about
10 7 MHz.

IC Q20 is a binary-en-
coded 3 Vi -stage decade
programmable counter (i.e,,
it divides by any integer,
not just powers of two). Ac-
tually, as used here, only 3
decades are program-
mable: units (A1-D1), tens
(A2-D2), and hundreds
(A3-D3). The thousands half
stage (A4-B4) is wired at one
thousand (i.e., A4 goes to
Vdd and B4 goes to ground,
a binary one). Frequency
division of the signal from
Q6 is therefore 1000 plus
whatever is loaded into
Q20 by the microprocessor,
Q25 (and interface ICs Q23
and Q24). Divisors range
from 1080 at 143.900 MHz
to 1999 at 148.495 MHz, the
limits of the TR^2400.

The phase comparator
reference frequency (5 kHz)
is derived from X3 (10.240
MHz) and fixed binary di-
vider IC Q22. To get 5 kHz
in this case, a divisor of
2048 is used, which is 2^\
hence pin Q11 on the sche-
matic. 10,240 kHz -s- 2048==
5 kHz.

The divided outputs from
both IC Q22 (reference) and
ICQ20 {signal} are fed to IC
Q21 , the phase comparator.
Any difference between
phases in the two signals
(usually caused by a dif-
ference in frequency) causes
an error voltage to appear
at pin 1, ''AMP OUT." This
output is proportional in
magnitude to the phase dif-
ference of the two signals.
This error voltage is applied
to D2 (actually a varactor
diode) to tune the vco fre-
quency and hence correct
the phase difference the
comparator in IC Q21
senses. Simultaneously, this

voltage is fed to four varac-
tors In the front end (Dl-4)
to ensure peak tuning
across the band in the re-
ceiver front end. The error
voltage was measured at
nearly 1/2 volt per mega-
hertz of frequency change.

Back to the beginning for
a moment. The trans-
mit/receive switching volt-
age used to drive Q7 and
Q8 is closely associated
with the biasing voltage for
diodes D9 and D8/D27.
These diodes select the
routing of the vco output
signal to either the receiver
(D9) or the transmitter
(D8/D27) as it is needed.

To complete the theory
of operation, the deviation
for transmitting is devel-
oped in the vco. Output
from microphone amplifier
IC Q13 is applied to D5 in
the vco, another varactor.
Thus, modulation is true
FM, produced directly at
the VHF frequency without
the use of frequency multi-
pliers.

Conversion

The most commonly
used portion of the VHF-hi
public service band of
usual interest lies almost
exactly 10 MHz above the
2-meter amateur band (154
to 158 MHz). The transmit-
ter frequency from the vco
(1 43.9 to 1 48.495 MHz) is an
appropriate injection fre-
quency to the receiver for
nearly the same range
( + 10.7 MHz = 154.6 MHz
to 159.195 MHz).

The only trick necessary
to accomplish this higher
injection frequency is to
use the higher-frequency
transmitter beat oscillator
(Q4) with the receiver and
turn off the receiver beat
oscillator (Ql) and D3. Two
wires can be rerouted
through the S. TONE switch
(if not being used) to shift
the receiver up band. No
critical or sensitive circuits
are disturbed, so perfor-
mance is virtually ensured.

9.6 V DC

4eJEerfiMH£

if f ^ TO C2. C4

JUNCTION

*ro ca

vcv

TO VCV LINE

Fig. Z Suggested circuit Note: LM358 is a dual op amp /n ar}
8-pin DIP designed for single-ended power supplies.

In operation, the collector
of Q7 is bypassed to
ground, which switches the
oscillators, as needed, but
not the radio circuits.

The Mod

Turn the radio off and
the TX offset to BU OFF. Re-
move the four rear screws,
back cover, battery cover,
battery pack, and the two
screws beneath the battery
holder. Disconnect the bat-
tery. Locate the empty area
in the center of the rear cir-
cuit board where the tone
board would go. Find the
red {V + ) and black
(ground) wires and short
them together (use a piece
of insulated wire if you
like). The red line will be
disconnected from V+ in a
moment. Replace the back
cover without screws.

Turn the radio over, face
up. Carefully lift the face
plate up and off to the right.
All these ICs are CMOS and
could possibly be de-
stroyed by statWfc charges on
loose fingers or tools. There
is no need to touch these,
so donV Note: You will be
on a remote lead of the
microprocessor (PA2), but
this lead has static protec-
tion (C9, R66).

Find the 5. TONE switch
assembly in the top, center.
Just to the right of this
switch is a black wire
marked B1. Follow this wire
down to the bottom edge of
the board. Remove this one
end of the wire from this
point by cutting or un-
soldering it. This discon-
nects the red wire on the

bottom board from V + .
Lay the black wire aside.

In the lower left corner is
a shielded portion of the
circuit. This is the vco. At
the top of this box is tran-
sistor Q7 and its associated
resistors. To the right, in the
2 o'clock position, is R18.
See Fig. 1. The wire lead of
R18 is the connection point
for the end of the black
wire removed above. The
lead on R18 has a ceramic
coating for insulation, part
of which must be removed
to make a place to solder
the black wire. This coating
will chip away easily under
a pen knife, razor blade, or
even serrated plier tips if
done very gently. After
removing the insulation,
solder the black wire to the
resistor lead quickly. These
small resistors won't handle
much heat for long. Don't
break the circuit. This is just
a convenient attachment
point.

That is the entire modi-
fication. Put the case to-
gether, careful not to pinch
any wires, and connect the
battery pack. Be careful not
to overtighten the screws.
Turn the radio on before
moving the TX OFFSET
switch from BU OFF,

Operation

This modification causes
the ON AIR indicator to be
on when the S. TONE
switch is depressed. The
transmitter is not on. The
microprocessor (pin PA2)
reads the collector of Q7,
which you just shorted to
ground, as the transmitter.

73 Magazine • February, 1982 27

CALL TOLL FREE

1 -800-238-61

• r»

In TN. call 901-683-9125

MEMPHIS AMATEUR
ELECTRONICS

(Formerly-Germantown-Sere-Rose)

Authorized Dealer for: Kenwood, Yaesu, Icom,
Drake, Mirage, AEA, Info-Tech, Ten-Tec, MFJ,
Cubic, and B&W.

IVION-FRI 9:00—5:00
SAT 9:00—12:00

^^ 139

Write: 1465 Wells Stat Rd., Memphis, Tn. 38108

Only the transmit beat os-
cillator is on. While in this
mode, I suggest you keep
the F LOCK ON and the TX
switch in the STOP position
to avoid inadvertent trans-
mission while monitoring. If
you do transmit, the trans-
mission will be in the
amateur band as usual. The
transmitter is not shifted up
band by this modification.

To receive the desired
new channel, subtract 10/7
MHz from the known fre-
quency (e.g., 155.61 MHz —
107=^144.91). Make sure
the S. TONE is off (up po-
sition] and program the
radio as usual for the cor-
rected frequency (e.g.,
4.910). Now depress the S,
TONE switch. As the ON
AIR flag appears, your
radio is tuned to the new
channel.

While in this mode, the
keyboard wit] not function,
just as if you were transmit-
ting; thus, there is no band
scan or memory scanning,

28 TSMagazme * February, 19S2

These features may be re*
gained by the more com-
plex modifications, or by
isolating pin PA2 of the mi-
croprocessor and keeping it
near Vcc (which I do not
recommend). If the radio is
turned on with the S. TONE
switch already depressed,
an incorrect display is likely
to occur. Simply turn the S.
TONE switch off, then on
again to correct the read-
out. Receiver sensitivity in
the new band will fall off
because varactors D1-D4
(front end) are not being
properly tuned for this high-
er range. However, sensitiv-
ity remained sufficient to
receive my local sheriff's
department near the edge
of the county.

Other Theories

The best theory requires
some careful circuit work,
but has great promise. Ba-
sically, if you add 2000 to
the divisor at IC Q20, all fre-
quencies would be shifted

up by exactly 10.0 MHz,
This is easily done by lifting
B4 from ground and con-
necting it to Vdd, or A4.
Thus, programming would
be just as on 2 meters — just
the last 4 digits of the fre-
quency, without the need
for a correction factor. Us-
ing this higher divisor would
allow using the receive beat
oscillator and keep band
and memory scan capa-
bility.

The easiest way to keep
the vco working 10 MHz
higher than usual above the
receive beat oscillator is to
isolate D3 in the vco by
breaking the control line
from Q2. An additional
switch would be needed to
switch it back in for normal
two-meter operation.

A more extensive circuit
addition may yield better
results. The AMP OUT line
from IC Q21 goes from
about 1.2 volts to 3.4 volts
(a range of 2.2 volts) from
143.9 MHz to 148.5 MHz (a
spread of 4.6 MHz], or
roughly +.5 volts/MHz.
Thus, to go 10 MHz higher
would require about 5 volts
more, in addition to 3.4
volts, for a maximum swing
of 8.4 volts. This is below
the battery voltage and is
therefore feasible, but may
not be practical. There are
several limiting factors that
must be checked before im-
plementing either modifica-
tion: T capacitance range
and response curve of D2
for these voltages; 2. main-
taining the supply voltage;
and 3, will tC Q20 handle an
input frequency of 20 MHz?

The output of the AMP
OUT line of ICQ21 is limit-
ed to Vdd, the supply volt-
age from regulator Q9, This
is 6 volts, or about 10 MHz
of total possible spread, us-
ing 1 volt as a minimum
figure and linear mode of
operation from D2. One
possible solution to this
limited voltage swing is an
amplifier stage with a volt-
age gain of 2 connected to
the battery line. The output

would feed varactors D2
and D1-D4 in the front end.
This may tune not only the
vco over the full 15 MHz,
but also the front end to
maintain sensitivity. How-
ever, it may be impractical
to use the unregulated bat-
tery voltage. Low batteries
and varying load conditions
(e.g., audio) may cause volt-
age fluctuations and insta-
bility in the vco.

Still one more option ex-
ists. Alternating X2 with a
crystal for 45,9333 MHz
would shift the transmit
beat oscillator exactly 10.0
MHz above the receiver os-
cillator instead of 10.7
MHz. These crystals would
be switched in or out by
means of their ground con-
nection. These two crystals
(X2 and X2A) would differ
by less than 250 kHz, so the
bandwidth of the oscillator
should not be a problem.
The accurate tuning of
these crystals is imperative.
To tune the front end, an op
amp could be used in a volt-
age summing circuit. (See
the suggested circuit in Fig.
2.)

The trimpot would be ad-
justed to add a preset value
to the vcv (varactor control
voltage] line to feed the
front end (only) when
switched in. When not in
use, both sides of the pot
would be grounded so it
would add zero votts for
normal operation. Note:
X2A may also work on the
receive oscillator side if Q1
is broadband enough, and
D2 will work on a higher
voltage. If so, change R3, 4,
and 5 (Fig. 2) to 220k and
connect the vcv line to D2
as welL Eliminate the con-
nection to Q7. This will re-
store memory scan again.

It is my hope that some-
one else will pick up on
these ideas and work them
out to completion. In emer-
gencies, such capability to
switch between ham and
police or fire department
channels could prove very
valuable.

Good monitoring! ■

VFO

I «B

VfO

Iniagine.,25 watts/5 mem-
ories/2 scanner systems
ina2"Hx5'/2"Wx7"D
2 meter transceiver!

A t^ery small package with a 25 watt
punch, the IC-25A is a full featured FM
transceiver for the space conscientious
operator- Nearly the same size as an auto-
motive AM radio> the IC-25A will fit in
places usually considered impossible for a
one piece 2 meter transceiver. The IC-25A
IS no lightw^eight when it comes to features:

• 5 memories. Store your favorite fre-
quencies.

• Priori t>^ channel Monitor your most
important frequenc>^

• 25 watts high/1 watt batter}^ saving
low power.

• Touchtone^^ mic standard. -no extra
cost,.;to work your favorite autopatch re-
peater,

• Full band scan/programmable scan
(set your owti limits)/memor\" sc^n....all
vdih automatic resume after preset delay or
carrier drop.

• 2 VFO's with data transfer standard.

• 2 tuning rates 5KHz (A VFO) or 15
KHz (B VFO).

• Nor/Rev switch for instant monitor-
ing of repeater inputs.

• Memory back up power supply option
holds memorv when attached.

Actual Size^
(CUp this actual photo out and try it in your car

^1 inches uide

PRI

S — 1 — 3^5 — 9—20'

OFFSET

KtllHaS!

WRITE

■ FULL'S SIMP

• PROG-S DUP

Hon

REV

S/S

yli^O"- vWtg.SQi-

\%4Mm TM i*l-MB A.

OFF

PULL LOW

^Hi'Sninim

'^umtm

\eniie jnc, oeuevoie, W A 9800-1
3331 Towerwood Drive, Suite 307, DaUas, TX 75234

ICOM

vfttem iwoce or filijiirinir AH tC0M ads* nm£i3wU% c%4f<4 Y t t r^^iuitii

lim Cray W1XU
73 Magazine St^H

Those Amazing Bobtails

the current-fed connection

The Bobtail antenna sys-
tem described in the
references has created
quite a stir Various com-
binations of construction
methods and feed systems
have been suggested
through a great deal of cor-
respondence between vari-
ous amateurs.

A nagging problem has
been the lack of a satisfac-
tory explanation of the op-
eration of the antenna
when it is current fed. It is
hoped that this article may
shed some light on this sub-
ject and spur others on to
try this excellent antenna.

To begin, we need a cou-
ple of definitions: 1) Volt-
age feed — feeding an an-
tenna at a point where a
voltage loop (or maximum)
occurs, 2) Current feed —
feeding an antenna at a
point where a current loop
occurs.

Antenna theory shows
that whenever you have
two vertical radiating ele-

ments spaced 1/2 wave-
length apart, the radiation
will be reinforced in a direc-
tion perpendicular to a line
drawn between the anten-
nas. By using three vertical
radiating elements Cor four,
five, or morej all spaced 1/2
wavelength apart, the radi-
ation will be reinforced in
the same directions as be-
fore, approximately propor-
tionally to the number of
radiating elements. Such an
antenna is known as a cur-
tain, Because our antenna
has only three elements, it
is known as a short, or Bob-
tail, curtain.

Curtain antennas of the
type described are bidirec-
tional, with radiation pat-
terns that look like elongat-
ed figure-eights viewed
from the top of the antenna
looking down. The figure-
eight pattern extends per-
pendicularly from a line
drawn between the anten-
nas, and when many ele-
ments are phased, the fig-

ure becomes longer and
skinnier and the result is a
bidirectional beam: a
broadside array.

^r-T

(NSULATQfT

I Ma,

iMib

Fig. 1. The current-fed Bobtait.

30 73 Magazine • February, 1982

In order to understa
the operation of the Bobtail
curtain antenna, one must
consider the antenna cur-
rents in terms of their mag-
nitude and phase relation-
ship. Ideally, in an antenna
of this type, all radiation is
from the vertical elements,
and little or no radiation oc-
curs from the horizontal
sections (flat-top portion)
because these exist merely
to achieve the proper phase
relationship between the
vertical elements.

Heretofore, the Bobtail
has been voltage fed by
means of a coupling net-
work attached to the bot-
tom of the center element,
although it is possible, if de-
sired, to attach the cou*
pling network to the bot-
toms of either of the verti-
cal end elements

For many reasons, in-
cluding convenience, ease
of matching, simplicity,
eltmiriation of coupling net-
works, and other factors, it
has been considered desir-
able to find another way of
feeding the Bobtail, and
such a method has been
reported as having been

used with success by a
number of different ama-
teurs. Here's how it works:

In Fig. 1 observe that the
Bobtail array, as before,
consists of the three quar-
ter-wave vertical elements
at A, B, and C, The two end
elements at A and C are es-
sentially a portion of the
flat-top and connected di-
rectly thereto.

The center vertical ele-
ment is separated from the
horizontal flat^top portion
by a small insulator at C,
and the conductors of a
coaxial feedline are at-
tached to the flat-top and
to the vertical element,
across the insulator, with
the center conductor con-
nected to the vertical, and
the braid connected to the
exact center of the flat-top,
at B.

Vertical element A is sep-
arated by 1/2 wavelength
from element B, and verti-
cal element B is separated
by 1/2 wavelength from ver-
tical element C Flat-top
sections A-B and B-C act as
phasing lines to make the
current relationships in the
antenna come out properly,
i.e., the current in section
A-B is iaO<^ out of phase
with the current in B-C, and
therefore they cancel.

STILL MORE
USABLE ANTENNA
FOR YOUR
MONEY . . .
PLUS 30 Meters!

Butternut's new HF6V
automatic bandswitching
verticat lets you use the
entire 26'foot radiator
on 80/75, 40. 30. 20 and
10 meters (fuN quarter-
wave unloaded perfomn-
ance on 15 meters). No
lossy traps. Butternut's
exclusive Differential

Reactance Tuning cir-
cuitry uses rugged ce-
ramie capacitors and
large-diameter self-sup-
porting inductors for
radiation efficiency and
DX performance un-
matched by conventional
multiband designs of
comparable height.

=t:

For complete information
concerning the HF6V Ef
other Butternut products
see your dealer or write
for our free catalog.

BUTTERNUT

GARY AIRPORT

BOX 356E Rte 2

SAN MARCOS, TX 78666

DAIV^A Communications

Essentials

Simultaneous SWR/Forward SWR & POWER METERS
& Reflected Power Readings

Tolerance: ± 10% full scale
Inpiit/output Impedance' 50 Ohms
Connectors: 30-239

Model CN-620B (New 2 Kw Scale) Model CN>720B (New 2 Kw Scale)

'■. !

,'/

I i J

Frequency Range: 1.8— 150WF5 Frequency Ranga 1,8—150 MHz

SWR Detection Senstlrvity: 5 Watts min. SWR Detection Sansittvrty: 5 Watts min.

PcswefT 3 Ftenges (Forward, 20/200/2000 Watts) Power 3 Ranges (Forw^d, 20/200/2000 Watts)'

(Reftected. 4/40/400 Watts) (Reflected, 4/40/400 Watts)

Dimensions: 165 x 75 je 97 mm; Dimensions: 1^ x 120 x 130 mm;

eii )c 3 X 4 in, 7 X 4 J5 x 5 in.

Model CN 630

Frequency Range; 140—450 MHz
SWR Detection Sensitivity: 5 Watts mia
Povifer 2 Ranges (Forward, 20f200 Watts)

(Reflected, 4/40 Watts)
Dimensions: 180 x 85 x 120 mm;
7,12 X 3,37 X 4,76 ia

Automatrc Antenna Tuner
Model CNA-1001 •

Frequency Range: 3.5—30 MHz
(Including WARC Bands}
Power Rating; 500 Walts PEP
Internal Dummy Load: 50 Watts/
1 Minute

Impedance Matching; 15-250 Ohm^
to 50 Ohms Resistive !■

Input Power Required for Automatic
Tunen 1, 6 or 10 Watts (Set by rear
panel switch)

Tune-up Time: 45 Seconds Max,
Power Requirement: 13,8 VDC^2 Amp

Coaxial

Swltche

Power Rating; 2.5 kW PER IkW CW

Impedance: 50 Ohms

Insertion Loss: Less than .2dB

VSWR: 1.1,2

Maximum Ffequency: 500 MHz

4 Position/
Model C5-401

2 Position/
Model CS-201

Exctusfve USA agent
for these units;
Enquiries invited.

Write for literature,

*-30B

iller Division

BELL rNDUSTRIES

19070 REYES AVE ■ P.O.BOX;
COMPTON, CAUFORNf A 9Q224

Phone <213) 537-5200

The currents in the ver-
tical elements are in phase
and add because the cur-
rent is traveling tn the same
direction at any given in-
stant (but the currents are
not equal tn magnitude).
The reason for this is that
the vertical elements are
each only 1/4 wavelength at
the operating frequency.
The current divides be-
tween the vertical elements
in 3 ratio of two to one.

In order to satisfy the
phase requirements, the
magnitude of the current in
the end elements must
equal the magnitude of the
current in the center ele-
ment. Since there are two
end elements and only a
single center element, the
current in the center ele-
ment must be twice that in
each of the end elements.

If you study Fig. 1, you
will notice that for a par-
ticular given half-cycle, the
+ and — signs are as
shown, changing sign at

each T/2-wave point. We
have assumed the feedline
to be exactly 1/2-wave-
length long. The arrows be-
tween the plus and minus
signs show the direction of
current during the particu*
lar half-cycle we've chosen
to illustrate. During the
next half cycle, note that
the polarity at each of the
half wave points will
change and the current ar-
rows will reverse direction,
but also note that, once
again, the currents in flat-
top sections A-B and B-C
will cancel. The currents in
the vertical elements will
again add in-phase in spite
of the fact that their direc-
tion is reversed. Thus, on
each half of every full cycle
the vertical elements al*
ways add irnphase and the
flat-top sections always
cancel.

ialeresting Side Notes

If you turn a current-fed
Bobtail upside down, it

looks like a much more
familiar antenna system. By
eliminating the phasing line
(flat-top) and substituting
ground, you have three
1/4-wave verticals spaced a
1/2-wave apart. This is very
common practice in anten-
na systems, for example, in
the broadcast industry for
directional beaming.

The disadvantage of all
but perfect ground systems
is the resistance loss in im-
perfect conductors Con-
sider, now, what happens
when we use the Bobtail ar-
ray: The "ground" becomes
the horizontal wire or flat-
top—nearly loss-free com-
pared to ordinary ground
and, better still, elevated
above earth by at least a 1/4
wave.

What this means is that
the antenna becomes more
efficient and the radiating
portion is raised The high-
current portion of an anten-
na is the portion which does
the biggest share of the

radiating and that is why it
is best to get it as high and
as in the clear as possible.
The Bobtail array accom-
plishes these things and,
therefore, is a good antenna
compared to one in which
the radiating portion is low
and the losses in ground re*
sistance are high*

One more item. Radia-
tion from a Bobtail is ver-
tically polarized and there*
fore, when placed as in the
configuration shown in Fig,
1, exhibits not only gain, but
a very low angle of ''take-
off/' as is typical of many
vertical radiators. Hence,
it's a good DX antenna. ■

References

1. Jerroid A. Swank W8HXR,
"The 2aMeter Double Bobtail,"
73 Magazine, May, 1980.
Z Jerrotd A. Swank W8HXR,
"The Amazing Bobtaii. . .Our
Headers Respond," 73 Maga-
zine, Decembef, 1980.
3, Alan Kaul W6RCL, 'The Both
tail Curtain: Round Three," 73
Magazine, Ju\y, 1981.

Wc VI c<»rnefed iJ^e DirkeJl

VERSATIU '"ify^i ^^^
USER PHOGHAMMABL£ CHIP

• iLny Itty ^iqu9ftc«. ineludmg aMstants
B«t dfll ii fintf II pofTiEs. ma V Be stored

iijceciilH'ft Ml Ihe Run h^iHjie
■ W Ili{» slor up capasiiv a^ up la 47
diridranl k»^ « F Ki^ad In « 12 x 4 mair 1 1

Its f)ossibia to tMnkl rna^v' pr>>jf cts wah this
ctMp Pm nuit Mid spKt siiiiplied mm srdei

WATCH
GUTS

PLUG INTO SAVINGS!

sunn

sioom

SfiOM

llillEitl.|:ifri .TS

LCD WATCH GUTS

(unlBiEiHJt J9

Mil Rfld M&lch, aw lour w«l«ti guts
iof S? «.

S 10014 Mtfltir>ti4ll|)trCrri1«l1)«CtL

i\f|ii.4WHfQw1.TTL[k!mpaCib6!
w/pftiduls 4.19

i 1 1

lM.

SlWOi

mtra inAiiii

Ttii Ewrle^l wt^ \t3 IH4 up yaur parts
bm OKU bwltfir We-ttvK^ a\\ sorts □!
ntst nmidfi. diKTBtH cam >cs.

B 10003 Omt lurtl » fsUU

Htlt/4J9

COPPER CUD

%mm rv»*oinHt3idKtpc

LINE PRJNTHfl
HAMMER DRiyEHBDARO

\m iMJiid canl^ins nopKHi ^30
♦■iKh sMJfBOO -iSi'itDn DiirlirH]
luri WU hir t^ t^, Abaur

•Htoii* OMtuQC a vBora lot a^

imok 41

CC.iM

A&fqrrm«iW90PD0ul^r

S«njuirs?4f^

SHOCKING SAVINGS

SiaQQ4 ItiV N CltllrEvi<r«^(lvl
Umi, wilt run vaiif wJilch
guK ji- <a1 longtM iriJin »
Qutlni) cell's i^

mvm n>ghi Ani}lf PfiQiH Jick
IPC Mc)ifPilii2fK««ch

ttivm 4c4ii^ahl5«f«ctq i

WiQODt S4WI frufttv W «^Aisi 1

vJuSr

"/* wm

RESISTOR
ASSORTMENTS

mm- msartm net

mm. I2#B Km
Kom ft^Tiw fimr^iii P

ntim,mmm.mmm

Aims fie$istv AtauPmM U
Diddle AlQiHin.

Avno? nesotur tnmnf* I

1DH£hLiaK.3ttL4 7K,

M. 18K. i as

AKMS ftssfftw Assorlnwnt F
KhBUh 2iV. ??K UK.

A 10009 Rtai&for A55ni fntflfil G
lOeajch: IMK. lflOt(,?30K

WCX GSOK.dfCK 2%
AlDOlO' Flesislor Assar tmeaT H
10 each 1M 1 7M 1 SW
l.BM ^^ 2 7M 3^

3m.*m.bm t^

Anmt RR;ftDrAs5Drtniii4A4i
include^atii'tiiiKir
jSssrtTnffiJjiKlO

X10003

4 ^ v^ « jl)^MA Aownip

INSTANT

REBATE

■ gram.

SHOCKING SAVINGS
CONT.

10042

t0Q0WfJ(25V
ElecErolyliefR)

35€ ea

BULit PHIiCE Vi-1 DO

22 U m T«i &9f

Electronic Sales, Inc.

Phone (206) 682-5025 (in Wash. State)
2300 First Ave. Seattle. Washington 9S1 21

JANUARY SPECIALS

BPACK CILCUUITIJRS
S6.95

l^eterfitAent-

rAflncp

CUARAHTEED GEFECTIVE! 1 1««^

briV^^VbKii MAT J^fftorii, MtfWWt

svnet mmm Pmtt mtm no* «eiM t% •
s^am feu »»» i^ um m di6ti3i

For Phone Orders:

TOLL FREE HOT LINE
1-800-426-0634

VISA

For Ar^as Outside Of Washington State
(Includiirtg Alaska & Hawaii)

TERMSi Mlninium order $10 00 /US Funds Only ,■■ Often aC-
counl to BChooh and govern men I ag^ndfis / All orderi
shipped UPS. or PP / Add 10% (posiage & handling) for o^"-
ders under StOD.OO. For orders greater than SiOO 00, we'll pay
Ihe trerght ,' Back-ordered itertia shipped prepaid ,. Washing-
Ion State residents add 5 4% sales lax / MasterCard & Visa
accepted / C O D"s odd $2 00 extra

We reserve- the right to limit quantities / All items subject lo
prtor sale • We reserve the right to sut^stitute rnenufaciurers

32 73 Magazine • February, 1962

When it comes to

AMATEUR
RADIO QSUs . .

rsthe

ONLY BOOK!

US or Foreign Listings

1982

NOW READY!

Here they are! The latest edftfons. World-
famous Radfo Amateur Callbooks, the
most respected and complete Hsting of
radio amateurs. Lists calls, license classes,
address information. Loaded witli special
features such as call changes^ prefixes of
the world, standard t^me charts, world-
wide QSL bureaus, and more. The U,S,
Edition features over 400,000 listing?,
wjth over 70,000 changes from last
year. The Foreign Edition has over
370.000 listings, over 60,000 changes.
Place your order for the new 1982 Radio
Amateur Callbooks, available now.

Each

Shippirtfl Total

Foreign
Callbock

$18,95 $S.05 $22.00
SI 7.9 5 $3,05 $21.00

Order both books at the same time for
$39.95 Including shipping.

Order from your dealer or directly from
the publisher. All dprect orders addshipping
charge. Foretgn residents add $4,55 for
shippirig. Illinois residents add 5% sales tax,

SPECIAL LIMITED OFFER!

Amateur Radio

Emblem Patcii

only S2, 50 postpaid

Pegasus on blue field, red lettering. 3" wide
X 3'* high. Great on Jackets and caps.

ORDER TODAY!

Ilbook

flADiO AMATEUR

OOK INC.
Dept. B

925 Sherwood Drive

Lake Bluff, I L 60044, USA

^^6^

DOUBLE BAZOOKA
COAXIAL ANTENNA

* Injection Molded Plastic Fittings for Strength,
Durabirity and Weather-proofing,

* Broad Banded Low VSWR

* No Tuner or Balun Required

* Feed With Any Length 50 Ohm Coax

* Power Handling Capacity • Two Kw

* Not A Kit - Ready For Use - Made in USA

* Steel Eyeietts For Installation and SO-239
Fitting Are Molded into Antenna

80 or40 Meter 39.95 ea.

20, 15» or 10 Meter , , , 34.95 ea.

tiowsp gain systecns __

□ Payment enclosed $_
D VISA DMC

Card no Exp,

Slg n at u re .

Name

date.

1007 E^presj ^gg

WsstMonro«, La. 71291

mM\ti ?li,j^

Address.
City

.State Zlp_

New Automatic Antenna Tuner

AutoTrack AT 2500

*--*' inqi i^^ ^.

mn^ ««fi tf .^

Designed and Built by J. W. Miller Div.

Check these state-of-the-art specifications

Power Capability: 2500 W PER

Frequency Range: Continuous 3,0 to 30
MHz (Including WARC Bands).

Impedance Matching: 10 ohms to 300
ohms to 50 ohms resistive.

Direct Reading SWR Meter 1:1 to infinity.

Direct Reading Power Meter: Two meter
scales from 0 W to 250 W and 0 W to 2500
W; front panel switch selects FWD or
Ref tec ted Power (iff urn Ina ted pan e/ me ters).

Power meter displays RMS with con-
tinuous carrier and autcmaticaity displays
PEAK when driven with S3B signal.

Dealer

Inquiries

Invited

iVerage "Automatic" tune-up time: tff
seconds or less.

Tune-up time not affected by power level;
can be as tow as 1 W (5-10 W preferred).

Power requirements are 115/230 VAC 50-60
Hz, 10 W operating/5 W standby; or 13.5
VDC, 1 A opefating/.5A standby.

Antenna tuner packaged \n cabinet 17"W
X 53/4 "H X 14''D (Front panel handles or
raci< mount optional at extra cost,)

Wnte for literature.

Speclfjcatlcms 5Ub|ect to change without notice.

Division

BELL INDUSTRIES

19070 REYES AVE ■ P.O. BOX 5625
COMPTON, CALIFOBNIA 90224

Phone (213) 537-5200

See List of Advertisers on pag^ 114

73 Magazine • February, 1982 33

David I, Brown W9CCI
Route 5, Box 39
Noblesviile IN 46060

Shoot the Moon!

visual tracking for your EME array

{[} (2) {3)

-^- -i COL-^ CG:

HORIZ.

ROW- I

HOW -2

i3)
ftOW-

— CIRCLE

(4J

■4

(51

P?DW-

■5

€

'71

W-7

i.yj

VERT

ReTf5A<;E

f/g. 7. Video monitor screen presentation. White squares
with nunnbers are the maximum number of squares that can
be lit Dark areas are never lit One possible moon image is
shown by circle G7, This would light squares 6, 70, 17^ and
14. Adjust your lens or lenses for approximately this kind of
spot size. The numbers correspond to the LDRs in Fig. 10.

34 73 Magazine • February, 1982

IS your OSCAR or EME
array all automated for
tracking? Mine is, but 1 still
wanted a means of visually
tracking in a manual mode-
This article details the sim-
ple "moon" camera I came
up with to look at the moon
while I stayed comfortably
in my basement (Indiana
winters get cold!). It also
makes a fine motion detec-
tor or low-resolution sur-
veillance camera.

Take a look at Fig. 1 for a
moment. What I have is the
screen of a TV set or, in my
case, a video monitor.
There is no reason why you
can't feed the video output
of my simple camera to one
of the TV game modulators
and pipe it into any TV set
as rf on whatever channel
the game modulator out-
puts on.

As shown, the spot or im-

age of the moon has been
concentrated into a round
circle that just illuminates
one or more of the photo-
sensitive devices (more on
them later). Whenever light
shines on these devices,
their resistance is greatly
lowered and I sense that
change to light a square on
the monitor screen. In order
to have the different posi-
tions on the screen repre-
sent different aiming posi-
tions of the antennas, there
are two main requirements.

The first and easiest is
that the camera be phys-
ically boresighted to the
antenna. That's just a fancy
way to say that it has to be
aligned to look where the
antenna is looking.

Secondly, the photo de-
vices must be arranged in
an array that duplicates

what you want to see on the
screen and then scanned in
step with the monitor scan-
ning. These last two require-
ments are met easily using
the circuitry and board lay-
outs provided by this arti-
cle.

Since I have started you
out at the photo-sensing
end, let's begin there on the
circuitry and boards. The
first thing you will notice is
all the boards are round in-
stead of square or rectangu-
lar. This allows for mount-
ing in a round enclosure
(details later, under Me-
chanical Assembly). The
first board to consider is the
LDR Board, shown in Figs. 2
and 4. I used light-depen-
dent resistors (LDRs) as pho-
to devices; mine are about
V4 " in diameter at the light-
input end. This allows the
array of 16 LDRs you see
the pattern for to fit easily
on my round board.

To mount the LDRs in the
board, you need sockets of
some kind. This avoids di-
rect soldering and the pos-
sible altering of the resistive
characteristics of the LDR. I
highly recornmend an item
called a matrix pin by AMP,
Inc.; it is their part number
380598-2. These are single-
terminal push-in sockets

and are sold by many parts
houses and the magazine
advertisers. Just drill out
the circles to hold the
sockets of your choice and
load the board up as shown.
All leads come to the
board from the copper side
and pass through their
holes, leaving a small
amount of the stripped lead
on the copper side to solder
to, When this board is com-
plete, there should be
seventeen leads 4'' to 5"
long coming off the copper
side. (Use different colors
to avoid confusion.) 16
leads are to one side of
each LDR, and one lead is
common to all LDRs and is
called the video lead [VI D),
There is really no easy way
to test the board at this
point, so set it aside and go
to the counter chain sche-

matic in Fig. 3. The cor-
responding foil and compo-
nent sides are shown in Figs.
5 and 6.

The counter chain should
go together quickly, and it
can be checked out fully
when completed — less any
other boards. Load the
board as shown and then
check the test points using
a frequency counter or os-

Fig. 2, Foil side of LDR board.

cilloscope at each test
point against Table 1. The
starting point is at the 555
IC, as this is the master
clock. It should run at
122.88 kHz, and you adjust
to that using the PC board
thumbwheel pot, Ra. The
set you use for a monitor
will more than likely lock
up [have steady sync] if the
clock is from 122.0 to 123.5

kHz, but you may have
something called flutter
due to a difference be-
tween your divided-down
vertical (59.57 to 60,3 Hz in
the clock range just given}
and the proper 60-Hz rate
used to avoid beats against
the power line 60 Hz.

The wide range of toler-
ance on most TV sets
allows you a lot of leeway

-!.lAfll"<>j-ji^,-JO*iJ^w»'l^>I'^"!^l^^l"W^i-%»^'^'!

TO FtG 7
DECODERS

TO PIS. t
DECODERS

/h. j^ j'h

-»*t*?^i^i^

+ 5V

12 ^

i' B' C' D'
7490

6.7

!»

C2 - .01 FrtYUAR

Fig. 3. Counter chain. Set for a frequency of 125 to 126 kHz at Frp test point For this appli-
cation, CI = 220 pF, Ra - 10k thumbwheel PC pot Rb = 18k, V4-W fixed resistor. General
formula is: f = 1/7 = (1A4]/Ra + 2Rb) X C

JSMagazine • February, 1982 35

TO DECODER SOA^D A

M R

;■"*,

o„jy^^ •

4^W*

e-^

«-^''>-4#

• *

-^/<k«

0^V«^-a •

9^^"*^
&

j^^m

A^^%/^ •

■M>^*^ «

■. ■■ »■.

D>'VV4

M P.

P.R

W P

14
7490

7490

lift

e-'v^-fl' •

<8^ *^

flMVM) •

M7i

IMITE

t4 ■ r

li,Pi

tCAO

220fF
MtCA

® .;:

*MJ*

10«

.01
iRTUAil

MP.

«OT€

M P

W P,

• L€AeS fROU DCCOOEft
B0&RD e

riiSERT FROM CORPCn SiDC-
SOLDER -CLIP EKCESS OM
eOJHPOMENT SIDE SEfORt
INSERTtiie LORS

o AMP SO€fC£T P\H

U P MOUNTING
POST LOCATION

•'^ PLUG m LOR
Hei TOTAL

NOT£ - SEE TEJCT

M P MOy»«TING POST
LOCATIONS

^\-^ cAPAcrroR

0^^ JUMPERS

0 TEST PT.

Fig, 4. Component side of LDR board. M.P. designates

mounting post (threaded spacer) locations. Use alternate '''S 6. Component side of counter chain board. Standard
locations between any board pair, thus only three spacers schematic symbols are used to show component mounting
looking like a triangle between any board pair. Small circles locations. Solid lines connecting dots indicate jumper
are socket pins for LDRs. Solid dots are leads from decoder i^^ds. Circled x indicates test point
board B and should be inserted and soldered from the cop^

per side and excess lead on component side clipped off in the setting of Ra where using a 10k pot for Ra and
flush with board. Resistor symbols are LDR locations. the set will lock up and look junnpers in the fixed Ra

atright. If you can't get positions, a smaller pot can
things as good as you want be used along with fixed re-
sis toKs) to allow Ra to ef-
fectively tune slower. You
would have to find the two
extremes of Ra settings that
create a locked-up picture,
measure the resistance of
Ra in each case, and use the
difference as the new Ra
value. Then fixed resistors
make up the jumpers. Re-
member, the total must be
10k.

Example: If the set
locked up alright on resistor
Ra settings of 2500 Ohms to
7500 Ohms, use a new Ra of
5k and one fixed resistor of
2500 Ohms in either fixed
Ra {jumper) position. Your
new range then becomes
2500 to 7500 Ohms.

Ignoring the +V and
ground leads needed by all
boards except the LDR
board, there are only six
leads leaving the counter
chain board (A. B, C A', B\
CI and they all go to the
Fig. 5. Foil side of counter chain board. points lettered the same on

3fi 73 Magazine • February, 1962

WORLD TIME
WATCH

thi first micfoproeessor watefi
made especially for hams

24 hr. timer

microprocessor
water resistant

fofar assist

New Low Price

^$59.95

Ttie HAM'1 functions include local time,
worid time, fG^MT. too) coum-up and
count down chronometer, day, month,
date, atarm and hourly chime, It^s ideal
for l09*keeping, OX time conversion and
10 mifHjt« \.D, timirvg. The HAM-1 tea-
nires a high contrast Seiko display avMi
solar ceJJ battery assift. Battery life is
belter than 4 years. The HAM 1 is water
resistaril to 20 meters, the case is tOO%
sotid stainFess $teel and the crystal t$
scratch resistant mineral ^Fass. The HAM-
1 i% rugged and durable and has a 1 year
warranty.

2 METER AMPLIFIER

• 2 Watts In, 10 Watts Out • V.S.W.B.
Protected • Can be Used for F,M. & S.S.
B. • Led Status Indicators • Low Loss
SO-239 Connectors •Current Drain Less
Than 2.5A at 13.6 V.DX. • Massive
Heaisink •Buill «n T/fi Switch

TEMPO S-1 UPGRADE KITS
$39J5

upgrade your BStly Tempo S-1 to cur*
rent Production Specifications* kits
include: #450 M.A.H. Battery Pack
m Naw Cdse Assembly • Alt New Es-
cutcheons • SpkrJMic. Jdck w/Dyst
Cap • New Earphone Se iack • P.C.B.
and Parts for Easy Instaiiation •Detailed
instruction Manual • For Radios With &
Without T,T. Pad.
Other Accessories Available;

Spkr/Mic. Designed for S-1's.
Heavy Ouiy Belt Ctip. . . . .
Flex Antenna ..,,.....

To Order Call or Write toi

ADVANCED COMMUNICATIONS

INTERNATIONAL

2411 Lincoln Avenue

Belmont, CA. 94002 U.S.A.

(41 B) 595-3949

Add S3 .00 per order for shipping Si
handhng, California residents add 6%
sales tax. Visa, Master Charge accepted.

i& ft <i

$24,95
7.50
B.QQ

Discover the newest in
amateur radio - all in easy-

to-build, money-saving kits.

• Complete line of transi^ivtrs, Indudlng
the popular HaathkitNW'l 01,

• New deluxe antenna tuner puts you in
conifo) of all your power.

• Unbeatatjie values in receiver/
transmitter combos.

• VHF&HF Wattmeters

• Rugged Linear Amps

• Exciting 2-Meter Digital Scanning
Transceiver

Plus a complBte line of antennas and acc^-
sorieB---Bfl money-saving ¥alu^, now in the
new, 104-page Heathkit Catalog- Send for
yours today

If coupon is missing,
write Heath Co.,

Dept 011-662

Benton Harbor, Ml

49022 I Name

In Canada, write

HeattiCo.,1480

Oundas Highway East

Mississauga.

Ontario L4X 2 R7

I
I

^S5

Please send my free Heathkit Catalog.
I am not currently receiving one.

Sendto Haath Co., Dept 011-8«C1
Banton Harbor, Ml 49022

Address.

I aty

Stale

AM-421

.^448

IM !¥!-'•£ I

Zip^

1
I
I
I
I
I
I
I
I
I

decoder board A (Fig. 7). If
these points are outputting
according to Table 1, the
7442 decoders (I CI. IC2)
will decode the BCD line
codes into one of ten out-
puts. Since the D line is not
used off the 7490s, the 7442
becomes a one-of -eight
decoder. In IC1, positions 1
to 7 represent seven verti-
cal columns across your
monitor screen. Position 0 is
left as horizontal retrace
and is covered on the vid-
eo/sync board. ICl runs the
sequence of 1 to 7, then 0,
32 times before any change
occurs in the vertical scan
decoder. This means 32
lines that are identical In
vertical coding across the
screen. This is accom-
plished by placing a fixed
divide-by-32 chain between
the horizontal and vertical
counters.

In the case of the number
1 LDR, if light is shining on
it each of the 32 lines will
go white from a black
screen as it scans over the
column position 4 (center).
When this happens 3 times,

fig. 8. Foil side of decoder board A.

a white square is formed at
the top center of your
screen. When you have all
your camera boards to-

gether but no optics or
lenses over the LDRs, the
monitor screen will tight

white squares in the same
pattern as the LDRs are laid
out on the board if

Fig. 7. Schematic of decoder board A.

31 73 Magazine • February. 1982

TO COUNT£ft CHAIN BD.

a c V a* ^,

MtP,

GNP

'6 9 i€ f

CD 74 4? 0 74 4 Z

1 a I •

—4

MP.

I »4

TAO*

m p

T404

M.P.

i\ »

T404

*" T M W

e» c» JUMPERS

M P MOUNTINS POST
LOCATIONS

EXCEPT FOR LETTERS
V a M TO VIDEO/SYNC
BOARO

LETTERS 0 THRU K
AND 3 THRU Z TO
O^CODCR aOARD B

Fig. 9. Component side of decoder board A. Letters Vand H
are leads to video/sync board. Letters D to K and StoZ are
leads to decoder board B (except Vand HI Solid lines corh
necting dots are jumpers on component side.

> QUALITY parts at *
* DISCOUNT PRICES!^

FULLY AUTOMATIC RECOflD CHANGER

'"^■^'^

<V^

FU^-L SUM Di''i:r.FK-
B.S.R. MCIC3EL Cl^fl

PlATS 3 5, »*5 t 78

lU-OWD D^W«E» TJOeS NnfT iTCLUOl BASE Oft A.C

S 25.00 EACH 4 lor S90.00

co^^

4PDT RELAY

mm. *

• 3 * - r . . • f jc«i

»170 EACH

MINI SIZE
BUZZERS

^ i)^ to S »ii» 75t«a

WITH WLWE LCACtS

_llJ4io 3 wilt* T&e«a

^1^ WITH PIM TEfa^JfdM-S
WITH PtH TEf^l>«IM.S

^ 75 c each

COMPUTER

GRADE
CAPACITOR

3.8O0 mrd.
40VDC S1.00

6.400 mf d

60VDC %t50

20,000 mfd. 25VDC

MITSUMI

MODEL UIS'ASSF I
IVAAACTOR UHF TUHER

t.-]i7 .>Ar<:

22,000 rnfd.2SV0C

22,000 fnfd.40VQ^^
„ :^ . '" -!.' $300

4&000fnfd.25VDC

. ' Di*. * V* «iu« S3 50

S2.000mfd.1SVOC
, * .. < ^ I . ' - $3,00

72.000 mid, 1 5 VDC

ClUiPt t© *i t CiPACil 0*4 «k »•

S 25,00 each
ror $22000

16.5 VAC 1AMP
CLASS 2 XFMR

S3O0
EACH

fr, SEND FOR NEW 1982 .\
'*©• 40 PACE CATALOG f®

TYPE N
CONNECTOR

KthCS LJG V5fe B/U
FITS RGI5, HSS8,
RSl**!^ mi^7. RG13J
SOLDER TYPE
SI 75 EACH
10 fOf S16.00

®3

TRANSFORMERS!

120 volt
primaries

fi VOLTS flMSO mA

12 VX.T. It 500mA

1fi 5 W. al a AMPS

\B VOLTS »t 1 AMP

55 2 VCT m\ 2-B AMP $5 50

SUPER SMALL
PHOTO -FLASH

170 MFD 330 VOLT

1 V^'-t 7%'

2tor$1.50
TO for $7.00

STANDARD JUMftO
DIFFUSEP

RED 10 FOR S].SQ I

GM£N 10 Fofl &?.aa

YELLOW 10 FOR $?,S0

FLASHVR LED yif

S VOiT OPERATION

juMao Size

? f uR J L , 70

Bl POLAR LID
SUD MINI LCD

,Orft*K .009
20 m A «1 USv

10 f-'OR ^i.m

300 FDR SlB.OC
cXtANTlTT PRICES AVAILABLE

750 MFP 330 V
PHOTO FLASH

1 i/**" OtA.
$1.35 EACH

10 ^Foc 5^1 .ao K*^

CANNON xiiu-3-13
CONNECTO

J PROfJG
CHASSIS f€kMT
OfiNECrOfi

»00 EACH

10 for $19.00

RECHARGASLE

SEALED
LEAD -ACID

BATTEBIES

FLAT LEVER
MlHI-TDGaLE

SPOT (OW-ONJ

SIOOEACH
10 lof SB.50

100 fo| S7S00

2 DtA r^TfOC
mjZZMB SPECIAL

idivS4 00

lOOIor t^SOO

« VOLTS SAMP^n
5:^ it } X lil| IN.

S 10,00

• YOLTt TV2*»/
^^5 ji 2 A 'tlj iS. HR

$r2,50

2"ALLiaAT0fl CLIPS

7 clips for $1.00

fOO cJip^i For f 12 00

900 dipt for tSO.OO

SFlCtAl *

RF B01

HICnOVVAVE
TMAKStSTOn

S2 S^OEA

AU CLEaROfltCS CORP

905 S. VefmonI Ave, r^20

PO BOX 20406
Los Angeles. CalU. dOOOfi
(213)3e0'8000

Mon. * Fri. Salurday
9 AM 5 PM 10 AM 3 PM

TEAMS

^ OM«rtrili*t LiinrtH
A«}S2 SO

FIADIO STATIONS COMMON? NOT THIS KIND is a histOfy of comTnunJca
lions cqFtimeficing with ihe first visual systems, tefmirtatjng in a brief
deficripyon of \he elocuonica fitted In the modem merchant ship, and
c^niered afound the largest marme radio station In Canada. Halifax Radio
VCS. As a mambar of iha Royat Canadian Navy, Matro Goidwyn Mayar Inc..
A(r Services Branch Department ot Transporl, Gypsum Transportation Ltd,,
Royal Canadian Mounted Police, and Canadian Coast Guard. Mr. Floscoe
has enjoyed iwenty^five years as a radio operator. He operates Amateuf
f^aOio Station VE1BG and is an active member of Sociely of vyireiess
Pjoneef». Veteran Wifeless Operators Association. Canadian Amateuf
Radio Federation. Nova Scotia Amateur IRaOio Associal^on, Kinfjs County
A mateuf Bad io Club, Am^r I ca n Red 10 Relay League and World Ship Soc lety
Anyone with an interest In Amateur Radio. Ship Radio Stations, Commercial
Radio Opefaiing, Telegraphy. Aifcratt, Ships, or Nova Scotian should find
this book inleresimg «nd mforfnalive. R»«*m youT t<>py r»oi*. S«nd r^o
money at this tlm*. Vou wllJ be rhotJfl*d ol the shippjnn date, and will t>«
billed at that lima

S.G. Ro$qo«, Box 1, SHe 5, R.R.#5, Armddle. Nova ScoHa,
Canada B3L 4JS, (902) $60-2343. *^ ^

VoCom Power Amplifiers^

Drive
Le¥er 1

Output
Power

Model
Numb«f

1 50-200 mw

25W

2CO2S-^}0mW

1,5W

20-25W

2C025-2W

1 5W

4S-S0W

2C050-2W

1.5W

80-90W

2C100-2/'2S

2W-5W 1

>30W

2C025-2W

2W-5W

>50W

2C0SO-2W

2W-5W

>100W

2C100-2/25

10W

100W

2C10O-10/25

25 W

100W

2C1 00-2/25

25 W

100W

2C100-10/2S

with range-^xtendltig products
from VoCom

25, SO^ Of too Watt* Power— wnatever your
present output tevei — - from 200 mW hand-
held on battery saver" mode to 25W mo-
pile or base — yoy can use that to drive a
compact, 12V power amp from VoCom lor
much more lalk-out power (see chart).
Each model has a front panei switch to Jet
you go "barefoot" for short hauls, pfus an
L.E.D. indicator to show the mode you're
in. Fulf 10 MHz bandwidth gives you vir-
tually unchanged power across the entire
2-meter band. High efficiency design holds
down generated heat, low Input VSWR
saves battery drain by yotif radio's final
amp. Use the chart to see which VoCom
Power Amplifier gives you the power out
you'd like from the power that you now have.

Power Pocket'** Mobile Amplifier/Charger

— Simply plug in your (com 1C-2A(T) and
you have a 25W synthesized mobile rig --
take It out again, alt charged "and ready,
when you want hand-held operation. Ac-
cepts any rC-2A version. Delivers 26 W RF
output, 2'AV^ audio with 4'* speaker to
overcome road noise. Charge pocket
accepts al! icom battery packs, has inde-
pendent charging switch, mdicator. Mic
preamp makes Power Pocket compatible
with any mobile microphone and with
Icom speaker/mic.

5/S HT Gain Antenna boosts reception while
giving your hand-held full quieting out ot
spots youVe nearly dead In with a rubPer
duck: provides excellent improvement Only
8" telescoped, 47" extended. Better than
1.5:1 VSWR BNG conf>ector.

Spting-loaded 1f4 wave antenna ^nd 4"
Stubby duck afso av^iiabie- See your favonte
amateur radio daa/er.

VoCom

..^90

PRODUCTS CORPORATION

65 East Palatine Road
M Prospect Heights. IL 60070

^ I {312) 459-3680

Fcomand t02A mp tiaOiMJitsf^ *coffl»Amer*ea. inc
^^^wef Pc<ii*t and ¥dComiire trademarKs^VoGom

rgfi^j&y Vo<^ pjwHjctsCjo^

PfOHtjCi&CQfp'

»^See List of Aifvef users on p^ge t M

73Magaifne • February, 1982 39

COi_rilCJW 0€C0[)EII9

OPTION i -MQVKS kOA # »

FRiJM C0L-4/flaW4 (CENTER!

TO cat- 4 /HOW r ibtm center}

CHANOE ICe-l^ Z, 3 AS SHDWRf

BTW CENTER

fWSTEAO pf CEIiTER
OF SCREEN

Fig. 10. Schematic of decoder board B. Option 1 moves LDR
#9 from column 4/row 4 (center) to column 4/row 7 (bottom
center). Change iC8 pins 1, 2, and 3 as shown, and load LDR
at bottom center.

light is falling on all the possible7X7 or49-position

resolution. The complexity
is not worth it, and the
camera functions just fine
using only 16 of these 49
possible locations. This is
accomplished by allowing
the focused moon image to
be larger than one square of
resolution and using multi-
ple lit boxes to show where
the image is relative to
center screen (on target) A
perfectly aimed antenna
will produce a white + sign
at the center of the monitor
screen.

LDRs. This will be a fina
check that all is working,
before the mechanical
assembly.

The row decoder (IC2)
does the same job as the
column divider (IC1) but at
a slower rate, to handle
horizontal rows Therefore,
it advances one position
after each 32 horizontal
lines This happens seven
times, forming 7 horizontal
rows of 32 lines each- If
more LDRs and decoding
were used, the camera has a

IC3, tC4, and IC5 are
merely inverters to get the
low 1-of-8 outputs of the
7442s back to highs that
can be gated together in
further TTL logic. Figs. 8
and 9 show the foil and
component sides of
decoder board A.

The last of the decoding
occurs in Fig. 10, decoder
board B, where 7403 gates
are used to detect which of
the 49 squares the monitor
is scanning over and en-
able the proper LDR for
that segment. Figs, 11 and
12 show the foil and com-
ponent sides of decoder
board B.

For the positions that
have no LDRs, as you will
see more clearly next on the
video/sync board, there will
be no LDR enabled and the
video (VI D) tine will be at or
very near +V. This +V on
the V ID line will represent a
black screen on the monitor
in the final video com*
posite. For those squares
that have an LDR sensor,
each has a corresponding
7403 gate section. When
the gate is enabled, the
open collector output tries
to pull + V down to ground
through a load resistor. All
the LDRs are in parallel by
the video line, but only one
at a time can be considered
in the circuit— the one en-
abled by the scanning
chain.

Going briefly to point C

on Fig. 13, the video/sync
board, you wit! see a 10k re-
sistor to H- V in the base cir-
cuit of the first video stage.
The circuit is really a
voltage divider consisting
of that 10k at all times, in
series with either (1) an LDR
that is in series with the out-
put transistor of its 7403
gate to ground, or (2) the
10k alone with no enabled
LDR for those positions not
having LDRs.

Remember, I said + V on
the VI D line meant a black
screen. Automatically, you
have 33 positions represent-
ing no LDRs and a black
screen. In the 16 positions

having LDRs, the LDR rep-
resents the lower resistor in
a voltage divider and as
such will cause the voltage
at point C to be very close
to +V [LDR off- no light),
or very close to ground
(LDR on — light shining on
it). My LDRs swing from
several megohms (dark) to
about 400 Ohms (light).
That means the voltage
divider changes from (1)
+ V through 10k through
megohms to ground, caus-
ing the junction of the 10k
and LDR to be very close to
+ V, to (2) a series of +V
through 10k through 4(X)
Ohms, causing the junction
of the 10k and LDR to be
very close to ground. This
junction voltage controls
the base of the first video
stage.

Following through the
video for an example of one
LDR with light on it. the VID
line and point C wilt be low
or near ground, The first
video stage is just an emit-
ter follower, so no inversion
occurs and the base of the
second video also will be
low and the transistor at or
near cutoff. When it is cut-
off, the collector rises to at
or near + V, and this repre-
sents white on the screen.

The last stage is also just
an emitter follower to allow
enough current to drive a
750hm cable and the 75-
Ohm load presented by
either the game modulator
or the video monitor input
If the monitor has a gain or
video drive control, jumper
A to C in the last video emit-
ter circuit and omit the on-
board gain pot, RL, If the
monitor has no control or
the game modulator no in-
put gain adjust use RL and
jumper B to C to allow
some means of adjusting
overall composite video
level.

The base of the final vid-
eo stage has control from
two more points that
should be covered here.
The two transistors with H
and V for inputs are the
sync mixer and make up the

40 73 Magazine • February, 1982

final composite video. Each
time the H line goes high
[every horizontal line, posi-
tion 0) or the V line goes
high (every vertical scan or
field, position 0), the base
of the final video is
dropped to approximately
0,2 volts, or close enough to
be called ground. This is
sync-voltage output in my
camera.

If the video example
were reversed, using a dark
or absent LDR position, the
second video stage can turn
on only to the point where
its collector is at 1.4 volts.
This is caused by the two
diodes in its emitter for 0.6
volts apiece and the 0.2
volts from emitter to col-
lector on the second stage.
This 1.4 volts becomes our
black level, and allows for
the normal video com-
posite of sync being blacker
than black. If you consider
my composite video as
0.2-volt5 sync, 1.4 volts-
black, and 5.0-volts white,
then divide it down with the
level control, you will end
up with video composite of
very close to the standard
of 1,0-volt video, 0.4-volts
sync. It at least seems to be
close enough for a perfect
picture with stable sync,
and I felt that trying to get
any closer was not worth
the time or extra com-
ponents. Foil and compo-
nent layouts for the
video/sync board are shown
in Figs 14 and 15.

That about completes
the electronics package,
and if you have a power
problem, the 74Cxx equiva-
lents can be used for ail the
TTL devices except the final
7403 decoders The 555 is
running well below its max-
imum + 18 volts, but seems
content and quite stable on
+ 5 volts.

Mechanical Assembly

The area of mechanical
assembly will vary, as with
most ham projects, along
with its uses. For that rea-
son, rll outline how I did
mine and you can carry on

Fig. n. Foil side of decoder board B.

or modify from there. As il-
lustrated in Fig 16, the
housing on my camera is
PVC plastic pipe! That's
why all the boards are
round and separated by
three spacers between each
board. You can, thereby,
build up a board-over-
board sandwich by skipping
every other hole of the six
given per board to set the
spacers on.

Looking straight into the
LDR board, it is spaced
from the board below it by
3 spacers in a triangle, The
next board befow, by 3 in an
inverted triangle, and so on,
I used 4-inch id. black pipe,
and would suggest that
whatever you use be black
inside to avoid light re-
flections and stray light.
You can buy end caps for
the pipe, and I used one as
is on the rear of the camera.
It was stuck on with rubber
cement for easy removal.
One hole in this cover al-
lowed the RG-59 feedline to
exit through, and a second
would have to be provided
if the on-board level control
is used — I did not use it.

The front cover 1 made

from another end cap, but 1
sawed off the entire lip
from the horizontal center

line down. This allowed me
to add small aluminum
brackets to one side To the

■4 JUMPER

# , LTR tN/OUT LINES

M P MOUNTING POST
LOCATION- SEE
ASSEMGLV NOTES

Fig. 12. Component side of decoder board B. Numbers and
letters indicate proper placement of input/output leads to
other boards. Solid lines Connecting dots are jumper leads
on component side.

73Magazfne • February. 1982 41

FIG ID

HI 'LEvei.
TEST POINT

COttPOSiTt

*5V

©r'^O Q^

;>o)c

PA»*EL Trt^E
FEMALE ftHC

-0

nc T

F/g, 13. Schema f/c of vic/eo/sync board. Al! transistor de-
vices shown are smail'Signal NPN devices in an RCA IQ
CA3046. Numbers shown around the e-b-c of devices indi-
cate pin numbers of that /C for reference and
troubleshooting. Note: If cable is terminated in 75 Ohms at
the monitor or a drive-level pot (usually 50 to 100 Ohms in
monitorsl use H from A toC and omit pot RL. If no drive
level is used on your monitor, jumper B toC and use RL as
your drive control to prevent overtoad.

bracket is attached a rod
that runs down the side to-
ward the rear to a small,
sealed, metal box that
holds a 4-rpm dc motor I
had lying around. It is much

like the ones the advertising
signs use, and I think it was
for 6-V dc battery opera-
tion. Plus 5 votts runs it just
fine, if a bit slow. This al*
lows me to remotely rotate

a 'iens cover" of sorts on
and off the end of the pipe
to keep rain, snow, dirt, etc.,
out of the lens area.

On the topic of lenses, or
optics, I am still trying for a
better setup, but one of my
prime criteria was that it be
cheap. After all, I'm trying
to avoid using an SSTV or
FSTV monitor camera be-
cause of cost, so why use a
camera lens that costs more
than the system electron-
ics? So far, the best combi-
nation I have found is with
dime-store magnifying
glasses with their handles
removed.

I fixed-mounted one that
was right at 4 inches o.d. at
the center of a 6-foot piece
of PCV pipe, and that al-
lows me to slide the elec-
tronics in and out towards it
from the rear. I also have a
33-inch lens mounted in a
4-inch collar that I can slide
in and out from the front of
the pipe to form a com-
pound lens system. That is
the area of experimentation
at the moment and 1 don't
mind admitting my physics
classes were too long ago.
Optics was never really my
bag, nor was photography,
so all help offered will be

Signal

Location

Measured Frequency

1- F,^

556 IC pin 3

122.880 kHz (for H

2. A

Column *C pin 12

61.440 kHz

Column IC pio 9

30.720 kHz

4.C

Column IC pin 8

15.360 kHz

5.0

-i- by IC pin 11

960 Hz

6.Q

-i- by IC pin 12

480 Hz

7, A'

Row IC pin 12

240 Hz

6. B^

Row IC pin 9

120 Hz

9.C'

Row IC pin 6

60 Hz

= 1 5,360 Hz, V = 60 Hz)

This has the horizontal sync running about 400 Hz low, but allows the vertical sync to be
correct to avoid vertical ^'flutter/' This is a compromise to reduce system electronics, but
all sets tried pulled in easily to the tower horizontal rate. The following is a representation of
ttie VID Ime with light shining on all LDRs. L rs TTL low pulses. Scope Horz, rate = 1/60 sec
per full horizontal scan or about 3 ms per cm on a 6~cm Horz. scale.

HHHLHHHSHHLHLHHSHLHLHLHSLHLLLHLSHLHLHLHSHHLHLHHSHHHOHHHS

H is TTL high, S is sync (app. 0.2 volts). 0 is option LDR 9

Table 1.

gratefully accepted.

The limitation of this sys-
tem would seem to be use
only during full moonlight,
but that depends on the
response of the photo de-
vice you use and the lens
system you end up with. As
it stands now, 1 can track in
some very hazy conditions,
and even clouds don't con-
fuse things too much. Next
to try is a full-blown in-
frared system, I think I

For all the OSCAR fans
who read on when the name
was mentioned in para-
graph one, I have not gone
bananas enough to try visu-
ally tracking an OSCAR sat-
ellite with the LDR system.
However, the same elec-
tronics system is being
tried, mounted in the same
waterproof 'type housing
with two full caps. The dif-
ference is that the 7403 out-
puts will be used to activate
PIN diodes [or similar
switching devices) on the
downlink antenna system. I
am trying to build onto the
outdoor, steerable OSCAR
antennas something like my
Twin lead Terror antenna
system [73 Magazine, No-
vember, 1977, p. 54J, and
then do the video add-on at
the monitor end using the
sync/white commands com-
ing down the 75-Ohm cable.
The video then would be
derived from some form of
the receiver age. I men-
tioned this earlier, in the
Twinlead Terror article
twhich got titled, "Cheap
Ears for OSCAR" V

You can do some posi-
tively wild things with
scanned and electronically-
steered antennas when you
have only receiver power
levels to worry about. It
becomes even easier when
you have a full-duplex, two-
band arrangement like the
OSCAR uplink/downlink.
The receive antennas scan
at a high enough rate to be
above audio, so you can
easily filter out the switch-
rate whine A I! you hear is
the additive result, but each
antenna's age product is

42 ?3Magaime • February, 1982

RAC

TRAC'ONE + DELUXE
CMOS KEYER

$119.95

Features:

Model TE'4e4

*Tru€ CW stgrial reproduction— Single &iQrui t^c&p-

lion

^Retnoves all QRM ana QRN
*04g& oul CW signal decodes il with Phasecl Lock

Loop Tone D^coOet tfmn reproduces it wiih fult

gperatof control ov& Gain. Freq, Tcwie, D&fay,
'All cpnlrois on Iront panel
•Freq control variable 300 Hi to 2500 Hz will rnaich

arty r^g.

*LEO Hashes f^uring decode* operat>on
"Oper^i^ In line wilti fig audio— leave in ijrw on

OFF/BYPASS
'Buill in speaker

* Headphones jack rear panel
*&atlerv or AC-adaplor. WOC ofsoratiofl

PLUS:

^Deluxe CMOS Keyer— '-State-oMtie arl'^ CMOS cir-
cuitry

*Seircompleling dois and dashes
'Solti del and dash memory
'Iambic keying wilh any squeeze paddio
"5-50 w.p.m.

'Speed, Volume, Tone, Tune and Weight controls
'Sidetone and speaker
'Semi-auto switch for bug or straight key

* Deluxe quarler-lnch jacks ior keyJng and ouipul
'Keys grid block or solid stale riga

TRAC*ONE CW
PROCESSOR

$89.95

Features!

Model TE 424

'TTMe CW signal feproduci»on— Singte^ignai recep-
tion

' Removes all QRM and QRN

*Dtgs oul CW signal, decodes if witn Ptiased Lock
Loop Tofw Decode< Itien reproduce it wnti^ tuN op-
erator control over Gafn. FreQ. Tor>e, Delay.

'All controls on *roni panel

'Freq control vartabte 300 Hi to 2500 Hz will maicti
any tig

'LEO f I assies during decoder operaiion

'Operates ifi lir>e with rig audM3 — leaTi^ in line on
OfF/BYPASS

* Built- in speaker

* Head|}}iones jiack rear pariel

'Battery or AC adaptor 9 VI3C operation *^76

SEND FOR BROCHURE ON OUR FULL PftODUCt UNE

ELECTRONiCS. INC.
1106 RAND BLDG.

BUFFALO. NY 14203

(716) 852-8188

RAC

HF MOBILES
DELIVER
FIXED STATION
PERFORMANCE

Hustief HF antennas deliver
outsftonding signal reports —
wtierever you're mobile!

Design your own HF rriobile
from a fu?l selection of tap-
qualrty; U.S.-made stainless
steel ball mounts, quick dis-
connects, rrxssts. springs, and
resonators. You can ccuBt any
6-to80-meter band. Choose
from medium or Ngh power
resonators with broadest
bandwidth and lowest SWR for
optimum performartce on any
band. Easy band change and
garaging with Hustler's fold-
ever rrxast. too.

T-l RANDOM WIRE
ANTENNA TUNER

Ask any ham — the best HF
mobiles on the road come
from: Hustler — stiU ttie
starKJard of p^ilofmoncs.

3275 North "B'Avwue
Kissimmee. Florida 32741

All bands {16010 mj with any

200W output - — Any trartsceiver

or portable — Neorf tuneup indicalor.

wire —
— Home

Only $32,95

T-2 ULTRA TUNER

Tunes out SWR on any antenna — coax
fed or random wire U^-10 roeter^}. Any
rtg — up to 200 watts RF output- Rugged,
yet compact; 5*/** x 2V<- x 2^^*,

Only $43-95

T-6 ULTRA TUNER

C««p«*i

Most vBfsatile antenna tuner available.
Any antenna ~ coax fed or random wire
(Ibb-lOm,). Front panel function switch
selects between two circuits — a Pi or L
network — or tuner bypass. Front panel
antenna switch. Relative output meter.
200w output — will work with virtually
any transceiver. ^V^" x a*' x 3'', Attractive
bronze finished enclosure.

Only $64.95

T-3 MOBILE IMPEDANCE
TRANSFORMER

Matches 52 ohm coax to the lower tmpe-
darvce of a mobile whip. Taps between 3
and 50 ohms. 3-30 MHz- 300 watts output.
2%' « 2" X 2y+-,

Only $24.95

DL-1 K4RLJ DUMMY LOAD

l»

The DL-l is a unique
chemical dummy load-
Untike messy oiMilled
dymmy loads, it will not
leak. Sealed ready to use.
Max. 1000 watts PEP for
15 sec. SWR Jess than
1.5:1 1-225 MHz. Portable
— only 3%' X 4^-,

Only $19.95

Van Gorden Engineering

P.O, BOX 21305
S* EUCLID, OHIO 44121

t^Sec Ust ot Advert ts&rs on p&ge ? 14

73 Magazine • February. 1982 43

Fig. 14. Foil side of video/sync board.

sampled, and only the high-
est is used to light the white
box on the monitor — sort of

a sample, hold, choose-the-
highest-figure, and use*for-
displav system.

INPUT LRD VIDEO
FflOM ytD
OH LRD BQ

INPUT \/ERT SVNC
FROM DECODER eOARD A
HOLE V

INPUT HO 2 SYNC
FROM DECOOER
BOARD A- HOLE H

I am still deciding wheth-
er to use steer antennas to
produce center-box white
scheme, or sample and dis-
play all levels as boxes in
the same arrangement in
which the antennas are me-
chanically set up. The latter
has the advantage of being
able to tell what polarity
sense the signal really is, at
the antennas, by observing
what box(es) are lit the
brightest, and to what
polarity you have those
antennas aligned. It does re-
quire small changes in the
video stage of the camera,
however, so you don't get
just saturated white or
black off positions in-

tentionally chosen for the

EME arrangement

1 have tried several sam-
ple-and-hold circuits and
antenna positionings so far
and have found none to be
the perfect result I want
Many such circuits are al-
ready around as described
in the articles over the past
couple of years and IO-
meter antennas are easy to
build, so you may have
your system running before
1 have mine complete. I am
working hard on the EME
version at the moment, but
should get back on the
OSCAR version soon.

The cost of the A-to-D
converter IC is quite attrac-
tive now, and with my love
for digital circuits I am go-
ing to try one more sampie-
and-hold circuit using that
type of device. It is an
analog in, 3 digits in BCD
output device covered a bit
further as an antenna read-
out device for use with CDE
Ham 3 rotator controls in
Ham Radio, January, 1979,
p. 56, The device used there
is an AD 2020 by Analog
Devices, Norwood, Massa-
chusetts.

If there are any ques-
tions, please include an
SASE, and HI sure try to
help you. if you come up
with other uses (surveiU
lance, etc.), please write, as
several people have al-
ready approached me with
ideas beyond what I had in
mind. Til try to act as a go-
between as best I can for
any new ideas for my
camera. Good lookin'.B

use i^Af^m HOSE clamps

TD ANGLE tnOhl FOR AlOUP^TmC

CABLE WITH
+ 3V AND 6N13

TARGET

CAP

ROTATES

ROD AND
BRACKET

JUMPER

(^'vv^^ RESISTOR

MP. MOUNTING

POST LOCATIONS

IN9(^ diode:

Fig. IS. Component side of video/sync board. Schematic
type symbols are used to show hading placement of com-
ponents. Solid lines connecting dots are jumpers on compo-
nent side.

MOVABLE
LENS

LEVEL
CONTROL SHAFT

OF REQ'Dl

nS^ED LENS
CAMERA

4" PVC PiPB

RG-59

Fig. 16. Mechanical assembly of the camera.

44 73 Magazine • February. 1982

f^esder S^fvice for facing page ^331^

♦ *'

M f"^-'

K H )

• \^.

,rrfl*^

1 j4

^ 2.M HanrtWW FM Traww**

r; msS5^tw1d lamp . o-s..™^"-"'

16KEY «m)«"CH • MV»a")w»«»

^ K'waWT SCAM I«1K8 . sc" -•"•»"" "«■»""'
"•"""^r^ POWER • 3 ««s wg". 1 «'"°"' '•'" ""^

*l^^ hand strap cfflvj^S^'^tw operator -
^^ and soac a stand ror xaow-ti^ ■'>^ ^^

TKj

l^lt^UFACtUF^E^

.>r» 1:3*

r'_-srt

T«»«»

ES^Cws^^-

4MATHUR-WH0tESALt ^^^^'^^"'^'^^

►'^- T«rra«- ■

*t^3356 Toii-<T«et800)^*

Mike Zedan WDSIiW
4221 turn Road
AttiC^ Mi4B4l2

Technical Clinic
PO Box 636

SterUng Heights Mt 48078

CQ MARS de IC-2A

work new worlds

H4RNESS

FRCaHAMWAALC
DIVIDER IC

juirpcn on

Bff!G>&£ MERE

BOTTOM

fig. 1.

Being a group that takes
pleasure in passing
along useful information to
fellow hams, Technical
Clinic sends this public in-
formation bulletin on the
10-minute frequency modi-
fication for the new I com
IC-2A hand-held. The short
and simple job will allow
operation (depending on in-
dividual radio characteris-
tics) from 141.000 MHz to
149 995 MHz

TC was pleasantly sur-
prised to discover that
Icom has made another rig
that lends itself to tinkering.

This happened while one
was on the bench for a
product development
experiment,

You will need only solder
and a low-wattage solder-
ing iron. The two-step oper-
ation is as follows:

1. De-solder the brown
jumper wire from the MHz
BCD thumbwheel switch.
This will allow the MHz
switch to run through its
whole range.

2. Solder a small piece of
wire (or form a solder
bridge) at the position

where the cellophane PC
harness terminates at the
programmable divider IC,
as shown in Fig, 1. This
allows the radio to recog-
nize a request for 148 and
149 MHz.

That's it. You now have a
radio with MARS/CAP capa-
bility which has not had any
of its normal operation im-
paired one bit. It is hoped
that all present and future
owners of this rig will take
full advantage of this mod
once their individual war-
ranties expire. ■

NEMAL ELECTRONICS

COAXIAL CABLE SALE

-Th^V'i^leSaVs

SuP^

iSP®

RG8X (mini 8) 95% shield . $14.95/100 ft.

100 ft. RG8U with PL-259 on each end - . .. $19.95

BELDEN Coax in 100 ft. rolls

RG58LI #9201 .......... .$11.95

RG8U #9208 ... $24.95

Qrouriding strap, heavy duty tubular braid

3/16 In. tinned copper. , . . 10^/ft-

3/8 In. tinned copper. 30'=/ft,

3/16 in. silver plated. IS'^/ft.

(HDLYETHYLENE DJELECTftlC
RGSaOU noi%-cOfit am mating 96% shield
RG21^3 nonconla/riinating 9&*/i shield m4 s#flc

liGl74/U mil &fmc ^% shield

HGI tU ge% shield 75 ohm mtUpec .
RGfiU 96V* gnreld mil spec . ,
RG&AAI double shiejd 75 ohm
RG55AUIRG223} double silv^ Shield 50 Ohm
HGS8U mil spec 96% shield . .

LOW LOSS rOAM DiELECTRIC

RG&U aO*/* shold , .

RG5SU 80% shield

RQ&aU 95% shieJd

RGMfU 10Q% toH shield TV type. ,

RGSU97% shield 11 gage

Rotor cable 2- 1 6gs 6-22Qa

ICab]e— ehipplng S3.00 1st 100 ft.. $2.00 each add'l 100

5665 SW 60fh. Str«0t Dept. 4X MU

Come See Us At The Tropic

« P I i

■ rf ■ ft

36^t'

07*tlt

07Vtl.
3VfU.

CQNNECTOnS MADE IN USA

PL-2^ pusli-on aiJaotef Shell .... 10^ 89

PL2S9 & SO-239 10/15 89

E>pLible Male Connecio' - . , .Si. 79

Pt258 Double Female Conitectof ge*

1 fi. patch cord w/RCAiyp« plugs each end. . ..3/$i.00

Reducer UG'1 75 or 176 . . . .10«1 99

UG2^(PL-2591O0NC) $3,50

Elbow (M359) Silver Placed $1.79

F59A (TV type) 10/ST.99

UG 2lO;u Amphenol Type N Male for RGB $3 00

Double Female N Chassis Mt. UG-30 $4.75

a/1fimch Mike Plug lor Gollirismc ...$1.25

Connectors— shipping 10% add'l, S1.50 minimum

FREECATAIOQ

ft. COD add $1.50- FLA. Rta. add 4% SalMTax

im], Fi. 33143 Call (305) 061-5534

ai Hamboree F©b 6th. & 7lh. *^^^^

THEY TALK

Spies ...
Smuggle^rs . , .

Plrale

StaHons .

Secret

Police . . .

Foreign
Agents..

YOU LISTEN

it Miniature Active Antennas
# Scanner Signal Boosters
it Frequency Converters
if Frequency Lists
^r Antenna Tuners
^ Code Breakers

Low cost

Fully guaranteed

FREE

CATALOG

C3ROVE

Far mdr* intormmUon wftim
GflOVE ENTERI>RISES

Dep*ftm«fil C
Braislown, H C. 26902

46 73Magazme • Febrgafy. 1982

ATIONS I

has acquired tne Antenna

Rotator Systems product
^roup of CDE (Cornell-Dubilier

I Electric Corporation)

-^^

antenna

Famous Tailtwister''^ , Ham IV^^ ,
CD 45, AR 40 and AR22XL Rotators
join the other fine amateur products
manufactured and marketed by
Telex/Hy-Gain.

Now. the must trusted names in annateur
products are all being produced by the
same manufacturer:
0" Hy-Gain Antennas
[^ Hy-Gain Crank Up Towers
0* Hy-Gain Antenna Rotator Systems
0 Telex Headphones and Headsets
Turner Microphones

Effective Immediately:

Please address all correspondence

and inquiries regarding CDE

ienna Rotator Systems to the
central marketing office of Telex/
Hy-Gain Amateur Products.

nn-gain

^3ie TELEX CQMMUNICATONS. INC

9600 Akkieh 4«c Sa . lAnneapiite. MN 5542Q aSJi
iurope 82 rue de is |j§gio<n-crHQnneijr, 9^S00 Si. Oenia. frsnca

AmHfeur Antefins 5. Towers Roialofs MiCTOphones and Heao^efs— heard The wG^td rooiKJ

See Lmi of Ad¥effiS^rs on psgv f T4

73 Magazine • February, 1982 47

SOCIAL EVEHTS

Listings in this column are
pro^iiiefS free of charge on a
$pace'av3if3t>fe basis. The
fotiowing inform&tion should be
inctuded in every announce-
ment: sponsor, event, date,
time, place, city, state, admis-
sion charge (if any), features,
tafk'in frequencies, and the
name of whom to contact for
further information. Announce-
ments must be received two
months prior to the month in
which the event takes place.

knuHtnon heiqhts il

FES 7

The Wheat on Community
Radto Amateurs will hold their
annual hamfest on February 7,
1962, beginning at S:00 am at the
Arlington Park Race Track EXPO
Center, Arlington Heights IL.
Tickets are $3.00 at the entrance
and $2.50 in advance. There will
be free fiea-market tables, ex-
panded floor 3|mce, parking,
awards^ and a large commercial
areai, including the new com-
puter section. Talk-in on
146.01/Jt and 146.94. For com-
mercial info, call WB9TTE at
{312>-765-16S4; for general info,
call WB9PWM at (312)^29-1427.
For tickets, send an SASE to
WCRA. PO Box QSU Wheaton
IL 60187,

TRAVERSE CITY Ml
FEB 13

The Cherryfand Amateur Ra-
dio Club will hold its ninth annu-
al Swap 'N Shop on Saturday.
February 13, 1962, from 8:00 am
through 2:30 pm at the Immacu-
late Conception Middle School
gymnasium, 218 Vine Street,
Traverse City Ml. General admfs*
slon Is $2.50 and single tables
are $3.00. Talk-in on 146.35 and
146.52. For further information^
contact Jerry Cermak K8YVU,
Chairman, 3905 SI usher Road,
Traverse City Ml 49684. An SASE
wJ]] be appreciated^

MARLBORO MA
FEB 14

The Algonquin Amateur Ra-
dio Club will hold en electronics
flea market on February 14,
1962, at the MarltHDro Junior
High School cafeteria, Marlboro
MA. Sellers will be able to set up
from 9:00 am to 10:00 am and
doors will be open from 10:00 am

4t 73 Magazine • February, 1

until 2:00 pm. Admission is
$1.00. Tables are $5.00 if a writ-
ter> reservation is made before
February 7, 1982, and $7.50 for
any tables remaining after that
date. Refreshments will be avail-
able. Tatk-in on *01/-61 and .52.
For reservations, contact Mac
W1BK. 128 Forest Avenue, Hud-
son MA 01 749.

MANSFIELD OH
14

The Mid-Winter Hamfest/Auc-
tion wHI be held on Sunday, Feb-
ruary 14, 1962, at the Richland
County Fairgrounds, Mansfield
OH. Doors will open to the pub*
lie at 8:00 am. Tickets are $2.00
in advance and $3.00 at the door.
Tables are $5.00 in advance and
$6.00 at the door. Half tables are
available. Features will Include
prizes, an auction, and a flea
market, all in a large heated
building. Taik^in on 146.34/. 94.
For additional information, ad-
vance tickets, and/or tables,
send an SASE to Harry Friet*
Chen K8HF, 120 Homewood
Road. Mansfield OH 44906. or
phone (419^529-2801.

VERO BEACH FL
FEB 20

The Treasure Coast Hamfest
will be held on February 20,
1982, at the Vero Beach Com*
munity Center, Vero Beach FL
Admission is $2.00 in advance
and $2.50 at the door. Features
will include prizes, drawings, a
QCWA funcheon, and tallgatir^g.
Talk'in on 146.1 3/ J3, 146.52/.52,
146 04/64, and 222.34/223.94,
For additional information^ write
PO Bojc 3088, Beach Station,
Vero Beach FL 32960.

FAYETTEVILLEWV
FEB 21

The Plateau Amateur Radio
Association will hold Its fourth
annual hamfest on Sunday. Feb-
ruary 21 ^ 1982, at the Memorial
Buildfng, Fayettevflie WV. The
doors will open at 9:00 am. Ad-
mission is $2.50 and children
will be admitted free. Flea mar-
ket tables are $2.00, AiJ activi-
ties will be indoors and wilt in-
clude ARRL displays, forums,
exhibits^ door prizes, and wom-
en's programs. Hot food, re-

982

freshments, and free parking
will be available. Talk-in on
.19/, 79 or .52. For more informa-
tion* contact Bill Wilson
WA8YTM. 302 Central Avenue.
Apartment 2, Oak Hill WV 25901,
or phone (304)-469-99l0 or
(304)-469'93l3.

LANCASTER PA
FEB 21

The Lancaster Hamfest will
be held on Sunday, February 21,
1982, at the Guernsey Pavilion,
located at the Intersection of
Rtes, 30 and S96, east of Lan-
caster PA. Doors will open at
0800. General admission Is
$3.00; children and XYLs admit-
ted without charge. Each 8rfool
space with a table »s $5.00
(limited to two tables for norv
commercial use and six tables
for commercial use). All inside
spaces are by advance registra-
tion only, and the registration
deadline is February 10, 1962.
All vendors myst set up between
the hours of 0600 and 0800;
reservations will not be held
past 0900 hours without prior ar-
rangement. There will be free
tailgating In specified areas out*
side (if weather permits) on a
first'Come, first-served basis.
Food will be served at the
hamfest. Talk*in on 146.01/.61 or
146.62. For advance registration
or more information, write
SERCOM, Inc., PO Box 6082.
Rohrerstown PA 17603.

ELKIN NC
FEB 21

The fifth annual Elkin Winter
Hamfest will be heid on Sunday,
February 21, 1982, at the Elkin
National Guard Armory, iocated
one mile from Interstate 77 at
exit 85, Elkin HO. Breakfast and
lunch will be served at the ham-
fest by the Foothills ARC of
Wilkesboro NC and the Briar-
patch ARC of Galax VA. Talk-in
on 144.77/146.37. 146.22^146,82,
and 146.52, For table reserva^
tions, ticket inquiries, or other
information, contact Earl Day
WB4GQP, 131 Harris Avenue, El-
kin NC 28621, or phone (91 9)-835-
3509.

MORRIS PLAINS NJ
FEB 25

The Split Rock Amateur Radio
Association will hold its annual
eq uipment auct ion on Thursday,
February 25, 1962, at the Morris
Plains VFW Post #3401, located
on Route 53 in Morris Plains NJ.
Doors will open at 7:00 pm to
unload and Inspect equipment

and the auction will get under-
way at 6:00 pm sharp. Admis-
sion is free. Please limit your
items to working electronic
equipment — no lunk — and make
sure any loose parts are bagged
or boxed. The club will take a flat
10% commission on all sales of
Individual items up to $50.
Above $50, the club will take a
$5.00 commission on each In-
dividual sale. All commissions
are payable In cash only. There
will be refreshments available
and the site has plenty of park-
ing. In case of inclement
weather, the auction will be held
on Thursday, March 4, 1982, at
the same location and times.
The Morris Plains VFW Post is
located approximately 1 mile
north of the intersection of
Routes 202 and 53 in Morris
Plains WJ. For more informa-
tion, write PO Box 3, Whippany
N J 07981 ,

GLASGOW KY
FEB 27

The annual Glasgow Swap-
fest will be held on Saturday,
February 27, 1982, beginning at
8:00 am CST at the Glasgow
Flea Market Building, 2 miles
south of Glasgow on Highway
31 E. Admission is S2.00 per per-
son with no extra charge for ex-
hibitors. One free table will be
provided per exhibitor with extra
tables available at $3.00 each.
There will be a large heated
building with plenty of free park-
ing. No meetings or forums will
be held— just door prizes, free
coffee, and a large flea market.
Talk-In on 146.34/.94 or 147,63i
.03. For additional information,
contact Bernie Schwitzgebel
WA4JZ0, 121 Adairland Ct.,
Glasgow KY 42141,

VIENNA VA
FEB 2B

The Vienna Wireless Society

will hold the 9th annual ARRL-
approved WINTERFESTTm ^32

on February 26, 1982, beginning
at 8:00 am at the Community
Center, 120 Cherry Street, Vien-
na VA. Tickets are $3.00 and in-
clude one chance for the prize
drawing* Prizes will include a
Kenwood TS*630S HF transceiv-
er, an Icom IC-26A 25- W mob its
2-meter rig, and a Santec
HT-1200 hand-held, as well as
accessories and books. Excel-
lent food service will be avail-
able. Featured will be deaiers*
and manufacturers' displays, an
Indoor flea market, and outdoor
frostbite tailgattng. Tables are

$5.00 and $10.00. Talk-in on
.31/.91 and 146.52. For addition-
al information, send an SASE to
WINTERFEST"^f^ ^82, Vienna
Wireless Society, PO Box 418,
Vienna VA 22180, or phone Ray
Joiinson at (703)-938^3ia

DAVENPORT lA
FEB 28

The Davenport Radio Ama-
teur Ciub will hold its 11th an-
nual hamfest on Sunday, Febru-
ary 28, 1982, from 8:00 am to 4:00
pm in the Davenport Masonic
Temple, Highway 61 (Brady
Street) and 7th Street, Daven-
port !A. Tickets are $2.00 in ad-
vance and $3.00 at the door. Ta-
bles are $5.00 each, with a $2.00
charge for an electrical hookup
(limited number). Hotel dis-
counts, food, and drinks will be
available. Talk-in on 146.28/.B8,
W0BXR, For advance tickets
and table reservations, write
Dave Johannsen WBOFBP, 2131
Myrtle, Davenport I A 52804.

LAPORTE m
FEB 28

The LaPorte Amateur Radio
Club Winter Hamfest will be
held on Sunday, February 28,
1982, at the Civic Auditorium,
LaPorte IN, beginning at 3:00 am
Chicago time. The donation is
$2.50 at the door and reserved
tables are $2-00 each. For res*
ervations, write PO Box 30.
LaPorte IN 46350,

AKRON OH
FEB 28

The Cuyahoga Falls Amateur
Radio Club will hoid its 28th an-
nual electronic equipment auc*
tion and flea market on Stinday,
February 28, 1982, from 8:30 am
to 4:00 pm at North High School,
Akron OH. Tickets are $2.00 in
advance and $2.50 at the door,
Sellers may bring their own ta-
bles or rent a table for $2.00.
There Is plenty of space and lots
of free parking. Prizes include a
Kenwood TS-ISOS, an I com 3AT,
and an loom 2AT, A 16KTRS'80
Model III will be raffled at $2.00
per chance. Talk-in on 146.04/
.64. For more details, contact
CFARC, PO Box 6, Cuyahoga
Falls OH 44222, or phone K8JSL
at (216)-923-3630.

LfVONIA Ml
FEB2S

The Livonia Amateur Radio
Club will hold its 12th annual
LARC Swap 'n Shop on Sunday,
February 28, 1982, from 8:00 am

t^See List of Adv&rtis&rs on page 114

to 4:00 pm at Churchill High
School, Livonia Ml. There will be
plenty of tables, door prizes, re*
freshments, and free parking.
Talk-in on 146.52. Reserved ta*
ble space of 12- foot minimum is
available. For further informa-
tion, send an SASE (4 x 9) to
Neil Coffin WA8GWU c/o Livo-
nia Amateur Radio Club, PO Box
2111, Livonia Ml 48151,

PHILADELPHIA PA
MAR 7

The Penn Wireless Associa-
tion, Inc., will hold its Tradefest
'82 on Sunday, March 7, 1982, at
the National Guard Armory,
Southampton Road and Roose-
velt Boulevard (Rte 1), 2 miles
south of exit 28 on the Penn-
sylvania Turnpike, Philadelphia
PA. General admission Is $3.00
and a 6'x8' seller's space is
$5.00 (bring table) with an addi-
tional $3.00 for a power connec-
tion (limited number). There will
be prizes, displays, refresh-
ments, rest areas, and surpris-
es. Talk-in on 146.115/.715 and
,52, For additional information,
contact Mark J. Pierson KB3NE,
PO Box 734, Langhorne PA
19047.

WINCHESTER IN
MAR 14

The Randolph Amateur Radio
Association will hold its 3rd an-
nual hamfest on Sunday, March
14, 1982, from 8:00 am to 5:00 pm
at the National Guard Armory,
Winchester IN. Tickets are $2.00
\n advance anf^ $3.00 at the
door. Table space Is $2.50 and
table space with table is $5.00.
Setup times are 6:00 pm to 8:00
pm on Saturday and 6:00 am to
8:00 am on Sunday. For reserva-
tions or additional information,
contact RARA, PO Box 203, Win-
chester IN, or phone W9VJX at
(317)'584'9361.

MODEL

SO-1 UNIVERSAL ANTENNA STANDOFF

Price $29.50

U.P.S. INCLUDED

* Clamps to any size ptpe or tower

* Idedi for ubf & vhf use
(ringo ranger&l

* Quickly installed with radiator
hose clamps [two supplied)

*i Galvanlred durable finisin

-K Strong structural design

« Optional pully kit allows
quick raising and lowering
of all types of wir© antennas

PO-1 Pulley Kit - $8.50

IIX GOUIPmEfTT Ltd

P O BOX 9

DEALER INgUtRIES iMVtTEP

OAK LAWN IL 60453-0009
12)2) 424.7007

1^474

MAOt IN U.S.A.

YAESU FT 207 n
ADJUSTABLE AUTOMATIC RESUME SCAN PCS

SAVE M 0 N EY — AiW iTw auta scan PCB to yotir FT-^OTR
now and scaii Memory and the band Ilka- the- 1>«« Irarqacalv-
e^s, with Aulomalic Scan Rsafafl on "ACTIVE" chanfiaH.
Also, you ean now s^t Ihe tiet^nin^ (ime to auil youf own d^
$ir^$^nd change i^ lel^r again and »gii>n

FEATURES:

*AdJua]at>le scan ^ale— Scan far "84JSY" Eti$inft$l— Set scan

to fcsian duiornailgally in 4 io 12 secondd after channel

bec-om^s'ACTJVE"
'Scan Re3lart9-'<mn>Bdia]el)^ wiin cartHf dnofi— NO MORE

WAITING.
*Hfliia Scan Faatyr*— On any active channel— AuimriKtic

Scan Ftesiaft
'Ho PCB cnang«s m tfanscslMer— Simple rnstaHatioft— Four

wl^nes^Ona iransistar

*Scan en!lr# band in approxirrai«iy 2^ $ecotr>dE
■PCS bu ill a/Id te$tAJ
'Many nK»r^ l^alur^S
"Order WAF PCB 5-1. Include H,20 shilppiftg and Imridling.

N¥S rgsklenta include J"/* Sales tax

WAF PCB &1 S29.95

,^94

QRZ SCAN INC.
11 Pleasant Drive, Rome, New York 13440

parabolic Reflector Kll acji oc
9O0MHt-2,SGH£ ^M^.TO

A tow cost, htgh qualrty
alternative to snow sleds
and yagis. 44'' diarrieier, 2
preoe difrabJe lightweight
sie^l cor^sl. Includes feed-
horn bracket, pre— cut hard-
ware cloth and all hardware
needed for assernbly
Excellerit for weather satel-
lite and 12W MHj experi-
mentersJ

Our kit g^HQ corner in
a 2 ft. size wkh 19 db
gain- ONLY«4.60

TERMSr Check, Money order, Vrsa, MasterCard
arid C.O.D. [Add $2). Allow twoo weeks
clearance on checks. Shipping and hand-
ling charges. C.O.D. by UPS or parcel
post unless pre-paid witfi bank cards. All

WELCOME pricft?^ subjecl to change without notice

PHONE

ORDERS

AMATEUR KITS

2300 MHZ CONVERTER KIT. , ,,..,.., ,,..,. 136,00

Includes PC buard, pflfts h instruclion manuaf

SELECTIVE PREAMP , $44 ,6C

l^i?r 1.^56 Wish above converter This preamp can also t>e used ^4^.
other mafTufactufer'a boards for impifoved pfiifoifmasnce

VARIABLE POWER SUPPLY, ...,,.,, , n.A.»

Includes all components, case, overlavs, and built in antenna switch.

DELUXE 2300 MHZ CONVERTER KIT. 199.96

Re^omnn^Ad&d foi dxps^srHidc;! kit builders, pu^r-^iaga $^^<:tiv? p?^-
amp. n><xaf, i.l. .^mprifmr anci r^a-dnft crv.s^aE-canirolie{| Crsx^\\\mir^

IZV STATtONAH V POWER SUPPLY, , , , ^^kM

]rO\ use Afih DeruK.& Converier .j^nd 50c (or p^odLicl hiochure.

COMtlVG SOON
1i91 MHZ WEATHER SATELLITE CONVCffTER KIT HOME TVRO
NATION WITH POLAR MOUNT

TEXAS MICROTROIMICS

P.O. BOX 141ie
ARUNGTOIM, TEXAS 76013

817-860^5440 ^ 323

73 Magazine * February, 1962 49

The Father of FM

the tragic story of Major E. H. Armstrong

teanne H^mfnond

Atop the Palisades at
Alpine, New lersey,
across the Hudson River
from Yonkers, stands a tail

1 *

i g^^— --

Armstrong if} WW I uniform. (Photo by Bradley B. Hammond)

50 73 Magazine • February, 1982

Armstrong's radio tower atop the Palisades at Alpine, New
lersey, as seen from Yonkers. (Photo by leanne Hammond)

three-armed tower. It is ac-
cepted as part of the land-
scape by those who five on
the river's east bank and is
seen daily by thousands of
commuters on Conrail's
Hudson Division trains, yet
few know what this tower is
or how it has affected their
lives.

The tower and its ac-
companying radio station
were built in 1938 at a cost
of over $300,000 by Edwin
Howard Armstrong, pioneer
radio inventor, to demon-
strate the superiority of his
new system of radio broad-
casting-frequency mod-
ulation (FM). After Pro-
methean battles with the
broadcasting industry,
which fought to preserve its
investment in the estab-
lished system (amplitude mod-
ulation—AM), FM was finally
accepted and today is the
preferred system in radio,
the required sound in TV,
and the basis for mobile
radio, microwave relay, and
space communications.

As fittle known as the sig-
nificance of the tower is the
man who built it. Armstrong
was born in New York City
in 1890. When he was
twelve years old, the family
moved to 1032 Warburton
Avenue — known to family
and friends simpfy as
"1032" -in Yonkers. The
house, which still stands
just up from the Greystone
railroad station, was de-
clared an historical land-
mark in 1 978 by the Yonkers
Historical Society.

Next door, on the north
side of the house at the cor-
ner of Odell Avenue, was
1040 Warburton Avenue,
the home of Armstrong's
maternal grandparents. The
members of the two fam-
ilies were a gregarious lot,
and Howard's childhood
was a happy one filled with
large gatherings of rel-
atives, many of whom were
teachers. Learning was
prized. "Quick, boy! How
much is nine times five.

Howard Armstrong, about six years old, with his sister, Ethel

minus three, divided by six,
times two, plus nine?' His
great uncle, Charles Hart-
man, principal of New York

City Public School 160,
would quiz his nephew to

encourage his mental agili-
ty.

When Howard was four-
teen years old, his father,
who was American repre-
sentative of the Oxford

1032 Warburton Avenue, Armstrong's boyhood home in Yonkers. His earliest experiments
were carried out in the cupola on the third floor.

73 Magazine • February, 1982 51

His bedroom/workroom in the cupola looked out on the spot on the Palisades where his
radio station would later be (Photo by Bradley B. Hammond)

UniversitY Press, bought
him (on one of his yearly
trips to London) a book, The
Boys Book of Inventions.
Reading of Guglielmo Mar-
conTs sending of the first
wireless message across the
Atlantic so excited his imag-
ination that he determined
then and there to become
an inventor.

In his attic room in the
cupola overlooking the
Hudson River, Howard
Armstrong began tinkering
with radio. In those days,
broadcast sound consisted
of Morse code signals
picked up with earphones.
The incipient young invert-
tor set out to make them
louder. He was dogged in
his search and developed at
this early age a capacity for
infinite patience in his ex-
periments which was to
mark his life's work.
"Genius is one percent in*
spiration and ninety-nine
percent perspiration/' he

Armstrong consiructed /arge anlenna kites which he flew
from the upper stories of '103T" in an attempt to improve

reception.

52 73 Magazine • February J9B2

The young inventor at work on the '1032^' pole.

used to say in later years,
quoting Thomas Edison.

Armstrong explored
many paths in his attempts
to strengthen the sound.
Reaching up into the air to
better catch the broadcast
signals, he flew from the up-
per stories of 1032 large an-
tenna kites which he had
built with the help of his
Yonkers friend, Bill Russell.
He built a 125-foot antenna
pole, the tallest in the area,
in the south yard. His youn-
ger sister, Edith T'Cricket'l
helped in the construction,
holding the guy wires and
handing him buckets of
paint as he swung aloft in a
boatswain's chair. Neigh-
bors watched with awe and
apprehension. His mother,
however, had complete
faith in her son. When a
neighbor telephoned to say
that Howard was at the top
of the pole and it made her
nervous to watch, "Don't
look, then/' was her confi-
dent reply.

Howard attended Public
School 6 in Yonkers and
Yonkers High School, and
went on from there to Co-
lumbia University, com-
muting on a red motorcycle
his father had given him as
a high school graduation
present. His interest in radio
led him to the study of elec-
trical engineering.

In his junior year at Co-
lumbia, Armstrong's dil-
igent search for improved
radio reception paid off. He
invented the regenerative-
oscillating, or feedback, cir-
cuit which greatly in-
creased radio signals, made
them loud enough to be
heard across a room and
led the way to transatlantic
radio telegraphy. His sister^
Ethel, remembers vividly
the night it happened.
''Mother and Father were
out playing cards with
friends and I was fast asleep
in bed. All of a sudden
Howard burst into my room
carrying a small box. He
danced round and round
the room shouting, 'Tve

Major Armstrong's sister, Ethel, and her husband, Bradley Hannmond, listen to a crystal set
With their evening meai around 1920. [Photo by Bradley B. Hamniond)

done it! Kve done it!' 1 real-
ly don't remember the
sounds from the box. I was
so groggy, just having been
wakened, I just remember
how excited he was/'

Later, another inventor,
Lee DeForest, challenged
Armstrong's priority for this
discovery and the issue was
twice argued before the US
Supreme Court — which

found in De Forest's favor.
However, the scientific
community has always
credited Armstrong for the
invention and he received a
gold medal for it from the

Thomas j. Styles, Armstrong's longtime associate, Ethel Howard, and his mother. (Photo by
Bradley B. Hammond)

73 Magazine • February, 1982 S3

Billboard in Yonkers dating around 1921. [Photo by Bradley B. Hammond)

Institute of Radio Engi-
neers. Years later, the report
accompanying the presen-
tation to him of the Franklin
Medal, by the Franklin tn-

stitute in Philadelphia, also
credited him with the inven-
tion of the regenerative cir-
cuit.

After graduation from
Columbia in 1913, Arm-
strong worked as an inr
structor at the college.
When the US entered the
war in 1917, he Joined the
Army Signal Corps and rose
to the rank of Major— his
preferred title for the rest of
his life. While in the service,
he invented the super-
heterodyne circuit which
amplified even further the
sound of radio transmis-
sion. This invention brought
him into contact with David
Sarnoff, who later became
President of Radio Corpora-
tion of America and whose
bright and attractive secre-
tary, Marion Maclnnis, he
later married.

After the war, Armstrong
returned to Columbia
where he worked as an as-
sistant to Professor Michael
I. Pupin, famed physicist
and inventor. When Pupin

Armstrong and his wife, Marion, by the "1032" pote. (Photo
by Bradley B. Hannnnond)

54 73 Magazine • February, 1982

Close-up of the tower. (Photo by Bradley B. Hammond)

the ALL
NEW

tempo

/Tia

Tempo S-4

The first 440 MHz hand hefd and siilt a
winner.offers the perfect way to get into
an uncrowded band- Check one out at
your local Tempo dealer or wnte Henry
Raa'O S289 S-4T $319

Boost the power of your hand held or
mobMe unit with a Tempo solid state
powef annphfier. A broad range of power
outputs available at very affordable
prices. Please write for literature.

COMMERCIAL HAND HELDS

Henry Radio offers a fme line of UHF and
VHF hand heJd transceivers for
commerciat applfcations. The operating
frequency of the FMH-12 and FMH-15 is
135 to 174 f^Hz and the FMH-40 and
FMH'44 is 440 to 480 f^Hz. They are
extremely sturdy, their superb
dependability has been thoroughly
proven and the price is much lower than
you might expect. Ptease call for
complete Information.

Tempo Ml

Tempo does it again* This lime wtth the
worlds firs! and only ALL CHANNEL
synthesized hand hefd marine
transceiver, The Tempo M1 operates on
all marine Channels. ..both U.S. and
international, plus four weather
channets. Thisrsa real working tool and
a hobby ng with hundreds of uses it is
skillfully engmeered and built to provide
endless hours of hard use 1 watt tow
power— 2^/ watts high power postliuns.
And the price. LESS THAN $500,

more radio

"money

TEMPO'S ALL NEW S-15 SYNTHESIZED

HAND HELD OFFERS IMPORTANT
FEATURES AT A PRICE THAT DEFIES
COMPARISON.

Compare these features with any other hand held
available... the S-15 Is the abvious choice

* 5 WATT OUTPUT (1 watt tow power switchable)

* "EASY REMOVE" BATTERY PACK

* 1 HOUR QUICK CHARGE BATTERY SUPPLIED (450 ma/HR)

* BNC ANTENNA CONNECTOR & FLEX ANTENNA

* EXTREMELY EASY TO OPERATE

* PLUG FOR DIRECT 13,8 VOLT OPERATION

* 3 CHANNEL MEMORY. (1 channel perm lis non-standard repeater
offsets. 200 micro amp memory maintenance (standby)).

* VErtY SMALL AND LIGHT WEIGHT (only 17 ounces)

^ 10 MHz FREQUENCY COVERAGE: 140-150 MHz (150-160 for
export customers)

^ AMPLE SPACE FOR PROGRAMMABLE ENCODER

* SPEAKER/MICROPHONE CONNECTOR

* ELECTRICALLY TUNED STAGES (receiving sensitivity and output
power are constant over entire operating range)

^ LOW PRICE,„$289 S-iS with touch ton© pad $319

SUPPLIED ACCESSORIES:

Rubber antenna • Standard charger • Ear
phone • Instruction manual • 450 ma/HR
battery {quick charge type)

OPTIONAL ACCESSORIES:

1 hour quick ctiarger (ACH l5)*16button
touch tone pad (StST) • DC cord * Solid
state power amplifiers (S-30 & S-80) •
Holster (CC15J • Speaker/mike (HM 15)

Available from Tempo dealers and

WmML

2050 S. Bundy Dr., Los Angeles, CA 90025
931 N. Euclid. Anaheim, CA 92B01
Butler, Missouri 64730

(213) 820-1234
(714) 772-9200
(816) 67^3127

•See Li$tof Advefttsers on page i t4

HEW TOLL FREE OtHER NtiMBER: (800) 421 15831

For aJ) stales eKc«p! Caliiomia

Calif le Sid ems please call collect an oyr regujar nurrtb«fs

73 Magazine • February, 1982 55

1
^^ 1

*^\]

r^:

In 1923, to celebrate the opening of New York's first radio
station — and to impress his fiancee — Armstrong cavorted
atop the new WjZ transmitter tower, (Photo by George
Burghard]

died, Armstrong took over
his professorship and, fi-
nancing his own research —
his inventions had by now
made him wealthy — con-
centrated on the eiimina-
tion of static.

In 1933, Armstrong se-
cured four patents which
were to be the basis for fre-
quency modulation. This
was an entirely new system
of broadcasting. Unlike
amplitude modulation
which varies the amplitude
or power of radio waves to
transmit sound, frequency
modulation varies the num*
ber of waves per second
over a wide band of fre-
quencies. As static is trans-
mitted by amplitude modu-
lation and cannot break in-
to the wide band of fre-
quencies of frequency
modulation, the latter is
virtually static-free. Arm-

strong, who enjoyed apho-
risms, liked to quote defeat-
ists who said, ''Static, like
the poor, will always be
with us/' He proved them
wrong.

The first public broad-
cast of FM was made in
1935 from the home of his
friend C.R* (Randy) Runyon
at 544 North Broadway in
Yonkers. Runyon was a ham
who operated under the
call letters W2AG and
broadcast from a tower in
the yard of his house. The
tower and the house are no
longer standing. The Run-
yon living room served as a
studio for a demonstration
of different kinds of sound
that were broadcast to a
meeting of the Institute of
Radio Engineers at the Engi-
neer's Building on West
39th Street in New York City,
Water was poured, paper

Armstrong receives the Meda! of a Chevalier de la Legion

d'Honneur for his contributions to wartime wireless, from
General Ferrie, head of French militarY communications.

was crumpled, and live and
recorded music were
beamed from the Runyon
tower to the audience forty
miles away.

Although the engineers
marveled at the fidelity of
the sound, FM did not im-
mediately take off and it
would be some time before
it would become a commer-
cial success. "If you build a
better mousetrap the world
doesn't necessarily beat a
path to your door/' Arm-
strong said ruefully in later
years as he fought for the
acceptance of his new sys-
tem of broadcasting. As a
matter of fact, FM was so
revolutionary that an entire
industry had to scrap its
hardware and start over
before its potential could
be realized. Understand-

ably, the establishment was
less than enthusiastic at the
prospect

However, for several
years RCA gave Armstrong
experimental broadcast
privileges in its studio at the
top of the Empire State
Building But in 1937, say-
ing that they wished to de-
vote the space to the de-
velopment of TV, they
asked Armstrong to with-
draw.

More determined than
ever to prove the superior-
ity of FM, Armstrong built
his own station in Alpine,
New Jersey. The site he
chose had been visible to
him as a boy from his attic
cupola at 1032, and it
served his purpose well. It
was one of the highest

56 73 Magazine • February, 1982

Bender Sorvfce for iacttig pugm ^ TCh*

Dual \TOs Give You IWo Radios for tlie Price of One!

Competitively priced, ig^uaHty
American design and construction
by Cubic ... a leader for 3 dec-
ide rn defense and oomnn#rdal

Features:

Ail band coverage Including WWV
and the new WARC bands

DUAL VFO's each provide com-
plete band coverage, (You are not
Umiled to a single memorized fre-
qtiency)

^5 Watts Input, SSB and CW on
lall fiBQuencies

IF Passtend Tuning not to be corv
[fiised with ineffective "IF shift "

Utilizes an 8 po(e filter which \b
continuously variable for either
high pass or low pass.

CW Crystal Filter (optional),
400H2 6-pofe

Unique Visual Display of
Passband

External Receive Antenna Jack
allows separate transmit and
receive antennas

Tunable Nolch Rller when com-
bined with passband tuning,
provides the ultimate m removing
interference

Full or Semi CW Break-In

Selectable hard/soft keying
makes the difference in pile up

Continuously Variable AGC lets
you hear ^e wBBk iignal whtcli
would nonmaHy be maslced by
strong sdiacent chsmel inter*
fefonce

Logrithmic Speech Processor

AF, RF and IF Gain Controls to
provide an Intinife selection of
receiver dynamics

4 Functton Meter reads "S" unite
In receive, and selects fonvard

power (calibrated in watts PEP).
reflected power, or ALC level in

transmit

Military Quality PC Boards of doy-
bio sMod, plated through glass
epoxymatsrial

Moc^lar Construction with PC
boards and assemblies intercon-

nected by plug-in strip line and
ojaj^iai connectors Chasms and
cabinet are of rugged steel con-
struction

Call or write for a Free Brochure

^^F^

CUBIC COMMUNICATIOIMS

305 Airpon Roitdp Ocean dld«. CA 92064 (714) 757'75?5

Complete System 103

PSU-6A
Power Supply 'SpeaKsf

ASTRO 103
Transceiver

15002- A

1 500 Wall Lsnear

Amplifier

ST-2B
2k W Anlenna Tunef

Interested In DX?

Dick Bash says you need THE COMPLETE IDIOFS GUIDE TO
DX (by Sfu Gregg, NF4Z) if:

you Ihink IRC means Internatidnal R&d Cross

you'r« sttll wofifing on your DXCC

you Ihink WAC means a female army p«rson

youVe not a BIG GUN (y«t)

ydy tNrtk the 'BUREAU' is wherp you put your

socks

The Idiot's Guide pulls no punches and doesn't 'snow' you
with nonessentmls. but it does unlock some DXers^ secrets;
for example: How to QSL. What to say, Where to place your
antenna, How much power to use. Whose awards can you get.
Why and When lo use SSB or CW. and much more- . .things
that you need to know, and information that Honor Roll mem-
bers had lo learn the hard way.

Dozens of DXers have been interviewed and their suggestions
have been included here. Take a tip from the "Big Guns' and
use their secrets and tricks.

THE COMPLETE IDIOTS GUIDE TO DX is available at dealers
nationwide for only $12.95, but if you can't stand lo wait, rush
Dick $15.45 (which will cover First Class postage). If you live in
California, please include 844i; for Sales Tax. Telephone orders
accepted 70 AM^-d PM Calif ornia time.

BASH EDUCATIONAL SERVICES, INC.

P.O, Box 21 1S

San Leandro^ California 94577

(415)352 5420

*^26

points in the region and had
unobstfLTCted space around
it for the broadcast of the

station's signal.

Programs originating
with WQXR in New York

City were transmitted by
wire to Alpine and broad*
cast first under the call let-
ters W2XMN and later,
WE2XCC. Today, the sta^
tion is owned by UA Colum-
bia Cabtevision Company
of Oakland, New Jersey,
and is operated for closed
circuit TV transmission.

During the Second World
War; Armstrong devoted
himself to military research
and allowed the govern-
ment to use his patents
royalty-free. He received
the Medal of Merit for his
contributions-
After the war, Armstrong
turned his attention once
more to the promotion of
frequency modulation. He
saw it grow in popularity as
a broadcasting medium as
more FM stations went on
the air and more FM sets
were sold to receive the
programs. However, few
outside the industry had
ever heard of Edwin
Howard Armstrong — the
man who invented it Fur-
thermore, manufacturers
began to build and sell FM
equipment ignoring his pat*
ents. Goaded perhaps by
the bitter memory of losing

Armstror}g at his desk at W2XMN.
58 73Magazine • Februafy, 1982

hfs regenerative patent
years before, Armstrong be-
came embroiled in twenty-
one infringement actions to
adjudicate hts FM patents.
Battling giant corporations
with batteries of lawyers
used up his resources. Final-
ly, in 1954, ill, disillusioned,
and his fortune gone, Arm-
strong took his own life.

After his death, his wid-
ow, Marion, set out to finish
what he had started. She
continued the lawsuits, sit-
ting in the courtroom each
day following the argu-
ments and watching as tes-
timony was given. Her first
victory, over RCA in 1954,
gave her funds to continue
the other suits. In 1967, with
the victory over Motorola,
she had won all twenty-one
and established clearly and
decisively that Edwin
Howard Armstrong was the
inventor of frequency mod-
ulation.

Today, the Alpine tower
stands as a monument to
the brilliant man whose iri-
ventions touch our lives
every day. His contribu-
tions are perhaps best
summed up by Lawrence
Lessing in his biography of
Armstrong, Man of High
Fidelity (J, B. Lippincott
Company, Philadelphia and
New York, 1956). "The lone-
ly man listening to music in
the night, the isolated farm-
er hearing nightly the news
of the world, the airplane
pilot guiding his craft safely
through the ocean of the
sky, the astronaut now in
his capsule gathering in the
whispers from space, the
earth bound emergency
crew contending with some
mission of mercy or di-
s aster, the army on the
move and the man in his
armchair, charmed or in-
structed for an hour by a
great play, a symphony, a
speech, a game of ball — all
owe a debt to this man who,
in some forty years of high
fidelity, fashioned the irir
struments illimitably ex-
tending these powers of hu-
man communication."B

WE SHIP WORLDWIDE

WORLD WIDE AMATEUR RADIO SINCE 1950

Your one source for all Radio Equipment!

All Handy Talkie* In Stock For Immediate Deliveryl

Vc»Com 2 meter SIB Telescoping Whip & Duckie

Antennas & HT Amp's HEAVILY STOCKED

Wo Will Not Bo Undorsoid
™^^ JlJ^ Call: 212-925-7000

World Wide Satelllta
Systems Available

SANTEC

HT'1^00.ST'7/T

YAESU

FT-208R

FT 290R, FT'ZOSR

tCOM
IC2AT
IC3AT
IC4AT

DRAKE TR-7 & R-7

L-7 2K W Linear Amprifler

DRAKE

Keyboard

MURCH Model UT2000B

FT-ONE

We Stock Special Satellite Cable.
BQ>213;U at $3.50 per/ft.
RG<59/U Stranded Center Core
at $0,25 per/ft.

DIGITAL

FREQUENCY

COUNTER

Trlonyx*

Model TR-1 000

0-600 MHz

Digimax Model [>S10 SONzlGHi

FT-101ZD MARK III, FT-480R,

FT-707, FT-720RU, FT 720RVH,

FT^902DM, YR-M1-CW/RTTY

AEA Morse Matic,
MBA & IsoPole Antennas

BIRD

Wattmeters &

Elements

in stock

ROCKWELL/COLLINS
KWM^380

MIR AG El
B1016

ASTRO 103 150A & 100 MXA
DIPLOMAT 150

ROBOT 400 & 600

ICOMI IC'720AJC-730
HY-GAIN IC-25A, !C-251A, IC-2KL, tC-4S1A

TOWERS
& ANTENNAS

KANTRONICS

MlniReadar

Field Day

Super Sale On Alt Surplus Parts, Meters, Capacitors And Connectors, Etc.. .Come In And Save Over 50%

LARGEST STOCKING HAM DEALER

New York Citv's LAHutbi tiiut^MNu mam utALbR we STOCK arrl & bash publications-

new lorK «#iiy 9 COMPLETE REPAIR LAB ON PREMISES

MAIL ALL ORDERS TO BARRY ELECTRONrCS CORP..
512 BROADWAV: NEW YORK C(TY, NEW YORK 10012.
BARRY INTERNATIONAL TELEX 12-7670 212-925 7000
TOP TRADES GIVEN ON YOUR USED EQUIPMENT.

AUTHORIZED DfSTS. MCKAY DYMEK FOR
SHORTWAVE ANTENNAS & RECEIVERS.

''AquI

Se Habia
Espanol"

1^305

WE STOCK— NEW ROBOT MODEL #500. BIRD WATTMETER, HY-
GAIN, LARSEN. SHURE, KDK2015R, TURNER. ASTATIC.
VOCOM. VHF ENG., MFJ. KANTRONICS. AVANTI, CORDLESS
TELEPHONES, POCKET SCANNERS, NYE, BENCHER,
VIBROPLEX, ALPHA.

WE NOW STOCK COMMERCIAL COMMUNtCATTONS SYSTEMS
DEALER rNQUlRiES INVITED. PHONE IN YOUR ORDER & BE REIMBURSED.

Amateur Radio Courses Given On Our Premises

Export Orders SKipped Immediately.

ELECTRONICS

^ m

61 Lowell Rd., Hudson. N-H. 03051

9^ Daily (603) 883-5005 ^^-S Sunday

TUFTS ELECTRONICS is pleased to introduce our two
newly affiliated stores. ARLINGTON RADIO is a new store
serving the greater BOSTON area. Their speciality is a new
system of CONSIGNED sales with an automatic mark-down
every thirty days. BUZZARDS BAY ELECTRONICS is an
established electronic supplier serving CAPE COD and the
PROVIDENCE area. TUFTS ELECTRONICS will be estab-
lishing a few more affiliate stores lo make your shopping
m.ore convenient. For details on how to become an affiliate
store contact our main office in HUDSON' NH_

ARLINGTON RADIO
1301 Massachusetts Ave
Arlingtari, Mass 02174
617 648 2097

BUZZARDS BAY ELECTRONICS

19G Main Street

Buzzards Bay, Mass 02532

617-759 3376

DISCOUN19- FREE CATALOG -EXPORTS- PACKAGES

3!:

l^M

■V BO-riv I*! DL

t*tMJt X W^f

4 *Bl "t»" m/*

IWJWK

m*^a MATT

TBM«

TD HW PWri LIMP Ml-m

iw iH Htm n HW& trnmn

if T/fl |ta|.fl3f ui

«rri

n.ao

19'. HI

-Ha r tmti 9d cwvn*] rwi

C^llVIl

m Li

i^tMF««nik

tt-t

IT,W

WOT1

I ■ L St l^.

41. •»

Mancltester

Nashua

in.t

■mfi

T.I

k^4«*> iiMi 'k^ i aji« ^rzm. =h>.i iKiw^
«mi-iM ■■« r^ mm^awu awrrw ^tatir
Lb-i<4i-rt n Mci n^ m ni-sqg^i^-ii ttm PS

ft, 40

eU«MCnAV~T fft<]><rzzcij'4'7CI «MHT«f4MAH

rat* j|xi~n4^ J' EHjM^ it^

■ 4

0,H

'-n i-w** p^rcv

m.-'9Hi API 'IJ im ^iLrm
*.- IWH I MHI Iff III r- 1 1 Tti
4h-l9H Iflm HI -^Mt 'llTpi
■t-Hiapfl «wi.l ■Mj ^ r II rip

■ike-^ «wnr Pitia ijt mm. Mr*

w^- '■ «m>i v«)^ «v tPi- *

t^-i 94t[Li m^nt *^ im-f

^LS ^iAELP "ir itv ™»T

^iv • ^HPiim ill

■HO ^MK I'M ■»<*

i ■■'

■n.m

If.

^••.^ pfT.^

PT>LC I ltp-n«ll l^AB
#T^(pip pHl iraT Ihit."

k^'^E. ppa' rjMWH PM PFPiw

■ . I ■ ■ u ■ — ■ .m — ^ ^fcjgaT^niri " ■ — *^

^mm 111 tuCtl-MI «l urp KPivaLi ■
ft-M« . Il MTirnff Mii TjprpirTPMJ l

■•■-■■§ ItT^yT n^mi^ ^a^inp

*3* V 'MGlta IP* i^ H KiPi Mr
^U-o e4 m^ IJP PW

ttt

IIM^tP

UirH

I.H

I Ml IP
ii«.lD

.11

I ^ *rw*-*mw % ■*>«

«-

jiTap ID-4V ^t* v<H ^tT I* K*i» if*^ ■*E.

Ic-i». wm fr It

ii.-^tm wrrr rw> ?1 k^rT p^lr TVta MK LIWK

dC-(pfa> ^ WTB lajLI ^B rm LM 'M'H T1k WTf:

ic-aifl i^TB n4.i|F^^]q. i^niii <rv>
ii-lm 1 1T> tALiii '■'-HI 1:1:1 pBii M^f^a

It-^n 3 Tm -ppp *tm\mmiM

IC-^it 'feaMJ PPP mTHB.f

■crsa7 * m* VHP »-^Tna.i

••-Il •t Hl»"n.¥ rm "jJmi

PT'» PC il.*#Ll »m 331B

1^-1 141 ■WTT t. II^PH kllh IL-H

■C-U twta pwrm DWiiMft PV irE'H

^-'* M.F^.J^C -DP^ IBI Lf-IA
^3 -^^ r^ t?i,TP mi3 Pai llL>J«

17 • 1 »«LI4 Hm

m--\ m, m net iw ttr-M

'kti EH ru-nn pzb r^m

.DA

irp.«e M^.at:
t9/t,vf zi^.'ap

^IrW

^^ "uz 4 riPi

■ r.

M-V

f1* 4

i*+t-

T^-Mf* fWli *.*■ Mn^ riHm Hr^ipti
u-f M* 1^ ■«(» Urn Uto aw *^Bt ip «c :
^t-iPK «p »i| i|ii|« imr ew HriN^ ^v

Hv^vM L'lM nMTitfMP4m

U.-lB

i»tit

-I* «,*i

■ i«.ip|

CUWMCflMPT » HI. I mm nNfaNMMH

ILECTRONIC5
Ent34 tB'fiiffJ

n-i* Ni-k«« wi If 1UMN1

ilM» LW.kPJ. mt |i auiVT
IIM'* I«4.ft'k4«mi I* EL^iVlT
»Wk V 1I.4* ul*H imiimia nn

41*f-t P ILIMJ*!' UW rVLMT KM

«]4r'l> I I IM.IHIIO HM

p|if-jMt fu p).Ei«iiir |Bi «4rr in

PitP'U na> PL4r tl riiTM Fditi^idt ^4 ■«
MiiH AliAI PPrtkP LH-kMi IP4]

p|pp-|i»t \*^t i.a tLlrvMT 'RuipT laiLn^

A|kP-3<IF L«l )Wl 9il lUM^I lam 4<mt

Hiti' ^ vrB *ir rm» z r^iv

(W,»l

ipfrfn

J t-^m fppfkPI

lt*.|Hl

•xi.-aa
il.H

J J 1. 9a

PP.PD

HUDSON, NH
STORE HOURS

DAILY 9-6
SUNDAY 12-5

BOSTON

tMSia P il MailT m-^M* TWWH DCP

\m-i wrrfljH ■ bjemr ikiM tw t- ihmm

■HBk 1 b«wtr m f-iwBiw.

THmc3 9 hji^c"! t"J "**"■"

tmMii K^ i«w«!fa*ipp p ELrMMn ni-

D*IVI*^ 1 lLtl>«nT I 0-1 1 «Tri>* MHI
a«l* 1 tUlHMt Hi iStfii
»H^ 1 ILt^BtT 1.1 WTfP
|.a3*A p V.IfViii 4ti 4qrn* ■"<-
iiHBA 1 ptpi^T L.n* |[»pf IP pan*

aMtt* 4 iLCnltTr \.#* m* >< ma Pf
Lpra p^i^^Bj: <«rq piaoj: 13^

■pi ^

Kp.M

***■•■
lkfL«l

l.fp.l»

iltil.M
314. W9>

liu.pi

IT*- VI

1 1 1 . to

I44.IP

Flrli

iM.H n* v

D.I

wv-

r '*
*■ n

#* #*

» at «r w
• • H r' w

^ *..P ^ FT
f' H FT «p

4^ ^ El ilii

I* tm ** M
I •.■ ■■ *1

L«- P**.^

I h,i1 1

iPih4 t wm wtK^m wm*

T*P 10— I

'ID 4KTIIP PIP WTttH Mp IP *IIP~> WTK.

Hb-ic ■*f«P «ip Dii tiviAV IP muri

'iWQ-m^ PVHg^ 6I1IT^ WB NIIW MMlia

1i*D-240 IBHJIJ Tillll [■ Aim

Ai-fw ipiit^P^ liPK^ **!# mm* wm mit'»
ia-]id.i» ^-in i«tiLj icvp Hwe ^iBO' friippra
wet IK) PENQTi ^*q rip ri^iipi

VC'IH DlPITta. PIKB [:TltaFPp,LPP MitmK >(V <a-IIQ

4i|>i:Hi «[«i^ UrtCH^en >li-t»
1^ i.9* pvBii^ Min-PT Pip r^iia

B^ma CEPVi <r:^ DtprTPh pevum
lihcB^. «>«|k rVi » It

*t».wa

TPP-.iq.

^P. PS

PlCfluB'

[I*

TJi.t*

Tl.W

l'»J,»
41. ttt

lu.ln
4e.^

144. 1

4P«,3
i).1

#f,l

li^it jwyiL

P4II- L

r ■
a I

77} 1*41 EP-EIV ^^n M*.'i

«.^

3T «*

ITP.

•94-

rpiP-liqa »■« ^PU 11-1 II ■»■"*» FB.'i

KMI4TnO<l4 X CZH

p:in.p w 11 nDot-'H'MVi'Mcii HMn ppf-'va

* liLJl ppT -■■. RUiriHi HniW »E» ^ i-ti..ws

qJi4l-«BPgBP d^-PT" niHI^mHillPf r«p CN-BTIi'dtKJI iJi.H

VIHVnp fivHB. rjraicEJi taJM aipia F||,rcp it».^

UPHIFUT ii>MiFELTTi HEB4 ■JH.irr Mmut p El, na ll^.-vi

*3*.9li
Ztl.941

LiH.'ila

«tWf

!C iP>

LTT.q »k1,1

■<M.«1 IT-.]

ilrl

IT-:

tl-

•1^1
iii. Btan

1 t.
1«

■».1

Tlrl

E1-I

With the completion of our recent move to HUDSON, NH
TUFTS ELECTRONICS is ready to bring you more ex-
citing innovations. Our complete AMATEUR RADIO
CATALOG is again available, packed with DISCOUNTS,
PACKAGE DEALS and plenty of those hard to find items?
Our catalog is computerized and updated daily to assure
you of the best prices and the most up to date information
available anywhere. Come visit our NEW MODERN SHOW-
ROOM, Tufts Electronics is only 30 minutes for Rte 128
in Boston via Rte 3. With the SAVINGS from our
DISCOUNTS plus NO SALES TAX in New Hampshire
you'll be smiling all the wayf To make your shopping
even more pleasant our new store hours are 9-6 daily and
12-5 on Sundays. Come visit us SOON.

60 73 Magazine • February, 1982

DISCOUNT CATALOG

in-taill 2i-H. IiCh itXt PqiHI ) 4(TII e>/p iHI
Lll-IV-* rWVBlli: 4fe*l 1.^4 HUH* WWM i*ti«MH

w-fm'xxt xxB -v^MftK fmjt* m -bit
TiJ^na T^^* klP MB*^ b-t »* airr
ui'iiBf I'* ■!■» 'du i^ur a^t 'tin' #^p Bt

1^< Ik

44-111

4.1

zh.1

■ J J Pq.4.[liYtH./4Ar

t4..li>9

»1

W*,^S

|ICi«Oi-'On E=E3««r

*''>C

■MJMPlfM HICt

IC*T|^

I4V9.4W ZlSll.Hk

r4tii-lL.i

]

i-p^_a

t^^ XV^-r

ITT tT».^^ if.Sfl

«ir| -liivA -^i^ni Mr wmt hf w4<-SF^ ^^V

I.Hi

'h.1

fffff

WITH PURCHASE OF
3-TBA ANTENNA

ALLIANCE HD-73 ^

3-TBA Tri-Band Beam

10-15-20 METER

Fixed Station Antenna

in«r tvavv duty .CinntNtj^
liun •t^Diifliyiul' nvut
!jr<ig|]|(i dQarMion

TUPTS

ELECTRONICS

SAVE

■OTH ron emit

LIMITED iUrm^

-4 fV' atTdlpi. *t^antim n ii-rt rnr

pa, - »ti» -Ml

«f

•u*

I^t

bu IDM I'll I3VJ

13, 9»

4T.Wli
M.»

Bl-ao

4.9P
A-t*

Br'*

1 M'

!■

talOi

VM Pit iif BMK J/E*" (1
M^M^f W 't r»«P M«B4

IM ■ II «d rr rasB pw>w
TV- 1* y *^ rFEB. cnjp4a
THT'iiii m Fan TiiLr^ 4^fJf^
THT-iij m pair mj^p ithii*-
J- 1 1 BE MM hmij:i
aif 1 1 PC «fn K>1 H^

U* P^ com -V ■. 'HI r*^ iP«

at #-1 TfLfvi'ua iniL wi

u v^v « rar> -HUW BCP

II i4if«

1 «:p

.IIHt

*t,t9

*^*B

«t1B

'VI 'n<

MVK VIMKNIB 'TU^bBI

T>* ta94VM THtt

.IB* pni r BiBII

KPl.M WUi

Lki*.M IM.lBi

.AUAH

t-2

■ >«f

vim w i*f » V

tii.K

IT, 9*

IS EBU- *"* **!'
MMi^E&'ItlTWI B

■■LEB VUtTE DIIL
IB

aici

*(T

HJ^
*■<—

tltli

1 a.^ v< *l»

4..H
Tr»a

i!iv

^c n*i ttiMtt ^Mfl'9'n mj^imft iBl i*flMfeT n.*q -tmh

il*-'| Utrp« lin^t M AH3VI FUJI *S 4* KjIrPiOc irP.n III.!.*!

FI-IM4 NICH b*M>ri m'fimii wen* d Kjif/tAMr it*-** ■tI'/w]

■BF-WM #H «B|.kP«M ■TIlVi]''Ln^» Mil ■fcWT ^-n Bk.lfi

ELECTRONICS

«l

T* i+* . *

tic:i

^Fr-E*4 I 4m ^tt^^rwm a ^."b aiiD irpri

^FT-4M Tit ^^iJ HC1''~E* IMIprr* «9l 4 P t+^ht

TP4N-1rMO tfcic

]^ HIMt« i4«*Ml<

»4

-Ii

-StV.aC iMll. Ml

ki ■llk'-i

*11

n^*

A *^*t* F^

mAca Bi-KE] -miHi' I CI

n m 941 VuttiBiiEC

EV-*» SM* ILBeTBIMIC VKIP

tl J44 B4I.UII CHB [LEr14g>l1[; |t|*M

■i-m J*iatlili •Kw^T pf-^B

l-n* ^UUIK VBVK rtTBhT M'lW

d-Hi bw*4»iiM an n fmmr nn*

I»~B^ W ■

iB-.ae
|itt.ijf<

IIB'IB

at.H

61 Lowell
Hudson, N.Hb

rrr IH 1 1* I" y t Mim

^-m'E *«PBri« «i«vip

f-rv-«]l* tlk^MHllNftB B.^mi MOKLf.
Hlf% r«?»A< IVWJL.I Fm rrV-VQLB
TQCM lilXlLLI mimit WC^ fTV-4uik

Ytl^-««E fm -MlfT Hl*Hll lUlDCD PCHlllX 4.111 IM I

fp-**] mi; 1 1 MifiP"?

Fl-I«in iUf^lO PBin* FUM tirm ■•i«Br RkKITlA, iEfl.lW

EF--i-D1 Lflllawk "■ BirTTl Fin JDT

r^-i<ij' j.in'tiB* ti mt-ry t ¥:m fi-ib^
Fi-ibT mtritrnm 'itm'
FV-iflT tr14«««« 'J-O

^-tmr ■.HBH^ BIB^HB

■Fv-IAU BJiMB

^ rni 4* V4I

^B^OO I Ilk, to

tv*.a. pto.M
■S.P*

-W-VP Ml, W

I IB, to

■p^.aa d'jL.to
1lia,W «««,«

LT^IM 1*1. H

H.to

[«.«4 IH. H

II*. W I PI .to

E^.^ IW,:to

W.to

m ■« M* ■• »m«» I
^11 »4M qp ■!: Eli m

W II

t^K

T.3

r.l

p.to

I,]

BtC

4-1 ^Hi^r'NW F^ #«aipi

e;- e ¥■« B^ 4iP' >CHtoT 1
H^I Bllh I^T -MH [tol IBM4IT

iqu-LB

i ^^jlh ^n^VGO

*-l

FiV i^bLtok tUt-^LH

«ll ll-f

t»to

il.*t

to'to.

41. H

It.
ir.

fB-sh* phmbi ^n'BHtT<4lt1B
Tl»l il*P« S»4 ^
TC-l-iUIH. |.J]iBlha MTA

F«-f EDO. tna ■*'iw

i:i#-IfM BEHIIJh NtMv ULF ID MMtl PC4I
nlU-TTM' HPBBIV lArl r

fT-S. ^,t ^Ol «*• F Ik ™«
DC-TTm ^ M<l> IIP Fl^

raiv-T'c^ HB- t*» mtt H»*i«'iP'
Tt-lp. i^i# nil fT^hilB
t^ [<■ *rB ^tC HltiLD Fl^ ■FlfTlB'
fB-I* to* ■!! WkrVB VW MCI^^ir

•v-H le^ ^rr iiir^PBT

n T~ -ia*4 toe twr>Ti^

fi-

l*-H

to. to

ffu.lll

fto-to

C lltl.lB

n,i»

llt.H

p*>to

»,to

■«*.to

ir.to

n.i»

«i.

WKI_L.pR

EE-IH4 IDLHk w^tifran. wmi m Mfe iitm
Ml-nt TIB IMP VMSIilf

iA,p«H MM ito/tto tor™

|i:^ili> bv.-K]

|*«.M ■I9..M

t«,#| 14., Pt

HhI* B-to

tt, tB ».to

to.<il U.H^

«.B iLfl*

l«iM> t-^

to,t< n.to

M. to u.'to

tT.|« flL ■»

(n.1

-lit

»-m

M-to

f ^TT

^T-1.3^ il iptBMn i'nt I'" 'c:''^
rT^4^ it^ iiu >«M > >^F lO

n.^BB 111 1-Tt IBll iTtBl BJ-1I-

^i-fl 14 ilto

mic Fi

1.1*

aj*,« lin.to

iTP.Hl «|4.to

-to «*!.]

ft, to

Lto. trt.to

■.It

•^toi

Hkto

-i+

m^^*

Vf I

PUFT^ liMtC

CT IflF

IpQ

kTf4.L[Pi inyiiBiif
H IBPWm V MIPIU CBJLnVP''

ww^Tllto Bl EMOi iWrntaaf
'IC9 m««tCIH

T.l^
LB

jg PLlMi Btwi: ^>viJt< ainfW BUINI* to^r* d'to

"^to J»t: pi' oji-iVMi B.IW iCl^MUTffi LiH^ tr.to

««W^ d« -ftj-H ■ I ^t rm EPPIflB im- V^JIB fBB* *^ P*

IPI,-3J BMMMIvVn ^ I niliJ^ CFB 4 mfTTto- 14.19

lu-^i 1 1 ph F11 i-Lim DjUtRi IPIWIMA «tol ij.K

nc miBvrKH B.L^ J0I41 Htufm i- t>^

■•BOP ttito OiniCii irBiFfni 11L4 biiiib kukii h.mt

■ pB {.Fn'hBM im KLBTXn tT , Hi

iC-^icKHi vvi'Ui^ rm. p^ii ii> rcn.'P it ^tvcn JBiT.H Jto^BB

n:-ilf>rr m vp- 34 -dtk. 1' tol^Vto HI BT> e»^ 7EI<-i« »<e.mi

n^lMBt mi B«V to r*iB!nMU X* toiwn » ^»« to*.!* IfetLH

l*Bl£ HUMC »

l««IC nto i«Mii: B»*

Vl-pD^aTVH Mmit diAOV Pt-BFEB
Vltofl-Pfl^VA «1B»«MBB Ilto.

Mi|pfHrAri£H arip dcli/iE

4BITBFMI1. toVhirt RKt
CKEBIPtA. l|1H|Bi|l(l 4>
L[»CE|M» KH tokUU
Ll4p4Mt« KB V1BBMM *t>t
&#iV]IW IMIfltoll IC Rl

l«<to
1*.H

^ IM1

EL.'

I».-
I*.,

DISCOUNTS

EXPORTS

PACKAGES

ORDER BLANK

[NlanTrfl^otj

1 "^^F"^^ J

MODEL

OPEN DAILY 9 -S
SUNDAYS 12-5

FREE CATALOG

DESCRtPTlON

QUANTITY
ORDERED

UNIT TOTAL
PRICE PRICE

61 LOWELL ROAD aSJbW

CITf _

Prices tubj^act to cnan^^ without mittee
CALL

STATE

ZIP

nUDoUlM^ iMn UJU^ Iq^j^^p^, £„g,(j,,(f a visa G lVlHBtBrC#rd P Sana Free Catatog
603-883-5005 Cird N&. . Ctrd Etip. Date

Shipping
H*nctlln9

Amount
Enelat«d

m.so

Hih.

Card No. -
SignalUfB

^$#0 Ust of A(fv9fft$ers an psQ^ t14

73 Magazine • February J982 61

DXPEDrnoNS international

THE WEEKLY DX NEWSLETTER FOR ALL AMATEURS

I =., 4

52 WKS

$28 (US)
$40 (US)

N. AMERICA
ALL OTHERS

Name

.^A

il^''*

Address

City.

SI.

Zip

DXI, 999 WILDWOOD RD,. WAYCROSS, GA. 31501

A TRUE STATEOFTHE-ART
COMMUNICATIONS TERMINAL!

NEW

from

INFO-TECH

$1475.00

(with 12" Monitoi)

$180.00

MEMORY EXPANSION BOARD
(10K of Memory)

For use by amatetir fadio operators In itue
tfansmissiofi aixj receptiao of RTTY (ASCII &
Saudol) and Morse code Micrc3proce5sof con-
Irolltd with 20K of memofy {BK ROW, dK RAM.
4K video RAM)

User programmable messages, SelCal,
WRU, mailboK, real lime clock, large running
bLftfsrs, buffers for printers, basic word pro-
cessing for on-screen editing, full and half
duplex, casserte tape interface. ^Iit screen
for mais, ASCII or Baudot prir^tef outputs, au o-
Slart, push lo talk, accessory switches, pro t-

Order direct or from these dealers:

(contains mailbox systems)

^ons fof tmUBty baok-yp, many other featufes

The M-500 consists ot jhfee parts:
1 KEYBOARD Connected !o mamframe tjy
5 -ft umbilical cord for maximum operating fSeKi-
bilify. Entire system keyboard controHed.
2. MAIN FRAME Houses 95% ot the elec-
tronics, all! /O jacks, power supplies, modulator.
demodulators. Mela -I fram^ cabinet is tabfe fop
or rack mounted.

3 12" VIDEO MONfTDR Htgh quality to insure
undistorted video, provrde flexibility for operai-
wyq position placement.

Carltof)

Msamh Florida 33173
(305) 271-3675

Colfflty Prodiiet&

14903 Beachvlew Ave

White Rock S C Canatk V4Blht3

(604^ 535-3056

Dislls Amittiif Rattta Supply

2n 4«m Si

Rapid Cilv, Sum Ekkoia S7701
(Bm 343'6t27

Electrcink Equipmant Banli
5ie MiNSI

VtBFtiu, vimtvA 2nBa

INFOTECH

RECTRONIC

EQUIPMENT

AtSMiiter Int.

52 ParJ< Ave

Parn Ridge. Niw Jetsey 07fi56

{201) 39l'7aB7

Global Cammunkcatlcifis
606 Cocca isles evd
CiMX»a Be^cti, FlofHla 32931
f30S) 753 3624

Him Ridllo CtflUf
S343 Qliv« BMt
St. Louis Wci$<un B3132
1B0Q 3?5 3636

DIGfTAl ELECTRONIC SYSTEMS. INC.

1633 Wisteria Court * Er>gl&wood. Florida 33533
Bl 3474 9518

1445 WMs SWkon Rd.
Manplvs. Tsnntssn 38108
t-8O0-Z3B'616B

Miclijgjn Rjdkl

.38??0 Mast

Mt_ Clemens. MJchigan 4^045

f3l3| 463-465G

II & & mstnbgllfii

7201 mt vm SI

Miami. Flwicta 33t3f6
(3G5J 592-9685, 763-8170

Um World

Tormmal Building
On«ida COiinty Atrport
Orishany. ftew York 13424
(315^ ne-0470
T'9X 448-9338

Ray' I AitiMfur Radii
1590 u : '^ i^***i iSSoath
Cteifwa;--. - ^'Kte 33516
\t\%\ 535-1416

UntVBrul AmalsiiT RaiNo
1280 A^ Dr

fleynotds&urg. Otito 43060
{614) 866-4267

For the best deal on

AEA* Alliance* Ameco* ASP* Beldeo
Bencher«Bird«CDE*CES« Collins
Commufiications Specialisls* Cubic
Cushcraft«D3iwa*0enTron*Dr3ke
HAL«Hustler»Hy Gain»lcom»IRL
KLM« Kantrortics* Kenwood
Lirsen* Macrotronics* NIFJ

MinJ-PrQducts*Mirage«NPC*Nye
Panasonic* Palomar Engineers
Regency* Robot*Shure*Sony
Slafidarrf*TfirTtpo*Ten-Tec
Transcflm*Y3esu

FEBRUARY
FINDS

ICOIVI IC-730 HP Xcvr. regular

$829 special $729.95

(less $40 factory rebate...
in effect througli February!]

KENWOOD TR-25G0 new 2-M
tiand-held in stock $299.95

HAL CT-2100 Communications
Receive Terminal $759.95
KB-21G0 Keyboard $157.95

YAESU FT-208R compact 2M
liand held Calll

YAESU FT-708R compact UHF
liand-lieid Catll

Quantities limited... all prices subject to
change without notice

We always have an excellent
assortment of fine used eguip-
ment in stock... Come in or call

CALL TOLL FREE

(outside HHnolt only)

(800) 621-5802

HOURS: §] 30-5:30 Mon., Tues., Wed, & Ffl.
f^^^' 9:30-9:00 Thuriday
9:00-1:00 Saturday

ERICKSON

CQIVIIVIUNICATIONS

Chicago. IL 60630

5456 North IVIifwaukee Ave.
|3l2|631-5t8l|wahintiimDisi

Ir^J

.- *, r

62 73 Magazine • February, 1982

AEA

ADVANCED ELECTRONIC
APPLICATIONS, INC.

MM 1 Morse Matic ProgrammabJe ht^yer 16 button pad tailors
ufiil to operate as a Memory Keyer, Mofse Trainer, Beacpri, or
Automat^c Serial Number Sequencer. Speed 2-99 wpm, 500
charade f memory. Use with all popular paridtes Keys gnd block,
calhode or transistor cucuits. 91&vdc @ 350 ma

Regular $1 99-^ - Sate Price $t79^^

IIT-1 Morse Trainer Generates random Mocse characters at
pcecjseJy calibrated speeds. 1-99 wpm. One character speed can
be seJected with another (sioiwert actual speed. Two levels of
difficulty Select five -letter code groups, or random won} length
Programmable aytomattc increase m speed from a beginning
speed to an ending speed over » duration of .1-99.9 minutes.
NormalFy operates in a random mode, but for cfiechmg progress, a
24,000 character answer bookie! is supplied S-lSvdc (§5 200 ma

Regular $99^^ - Sale Price $89^

WT-IP Morse Trainer Portable version of the MT-1. Take it with
you! Contains a rechargeable battery pack which provides hours of
practfce between charges.. With battery pack and charger.

Regular $139'' - Sale Price $125^'

CK-l "^ "^-^ "^ IIKI

CX*1 Contest keyer. Incorporates virtually afl of the features of the
famous MorseMatic, with the ejtcephon of the Trainer and Beacon
modes. Two pre set speeds for fast recall and a stepped variable
speed control for contesting, 199 wpm. 9 16vdc @ 350 ma

Regular $1 29^' - Sale Price $116^'>

KT-1 Keyer/Tratner. All of the features of the MT-1. However,
except for the on /off volume control all other functtons including
speed, stdetone pitch, wejghtmg. tune & more, are programmable
by using the keypad to address the internal microprocessor Speeil
variable, 1-99 wpm. Automatic tune function aJlows two harnfed
Amtr luning Trainer provides a sequence of 24,0OD characters with
10 starfine positions or a random point 9'16vdc @ 350 ma

Regular $1 29^^ - Sale Price $t t6»«

MK-1 Morse Keyer Features s^rmlaf to the keyer portion of the
KT' 1 without automatic tune tunctron 9^I6vd€ @ 350 ma

Regular $79^'- - Sale Price $74^

Keyer & Trainer ^ccessorie*.

WE-l 20O0 character meniory expansion for MM- L...... S59*'

AC I I2vdc/600ma. AC adaptor for MMl with ME-L 14*^

AC 2 12vdc/350ma. ACadaplor .,.,... 9**

DC-1 Cigarette lighter cord for all except MMP 5**

AEA MBA-RO Basic CW/ASCIl/Baudot Reader, feadsand displays up to 99 wpm
CWcopy. 60-67-75.100 Baudot & ASCII at 110 baud [hand typed. 300 baud) 32
character floyrescent display shows up to 5 words af one time 12vdc

Regular Price $299^^ - Sale Price $269^'

ll8A-ftC DeJuxe Reader /Code COriverter Simitar to the MBA-ftO with the addition
of 3 code converter which converts Morse CW input (o Baudot or ASCIi TTY output

Regular Price $399^^ - Sate Price $359^^

A£A PFDF Radio Direction Finder Locates signals quickly and accuritely; even
those appearing for only a split second. Self-contained computer drives eJectroni
cally spun array antenna, computes relative bearing within I"" and shows it on 3
digit Lf 0 display arid 16 LEO nng quadrant display Works with any FM receiver
4ust plug rnto externsl Speaker jack: has self-contained aiMlK) amplifier & speaker.
Inclydes 130-180 MHz VHF antenna.

Regular Price $749^^ - Sale Price $674^^

AEA ISOPOLE Ommdirectionai VHF Base ^tion Antenna A tin ique. efficient twin
H-waveier^gth design using resonant decoupimg sieeves. Factory tuned, low SWR
over entire band |ust assemble and install on I '4" mast Connections and
impedarjce matching network weather protected, wind survival 80+ mph Jr.
modeis are shorter, ^^wavelength design. All models are UPS shfppahte.

ISOPOLE 144 2 meter base station antenna , , , ,

ISOPOLE 144 Jr. 2 meter base station antenna . ,

ISOPOLE 220 220 MHz base station antenna

ISOPOLE 220 Jr 220 MH^ b^se station antenna

ISOPOLE 450 450 MHz base station antenna (Reg, $69^^) ...... . ,SAU

Afl pricei and ipedficationi. subject to change without nor/ci*

« f q ¥ r

3995

MosterCard

Call TOLL FREE

Use your Credit Card

New AES Branch Store. . .

CLEARWATER, Fl - 1898 Drew St Ph. (813) 461-4267

Store Hours: Won, Tue, Wed & Fri 9-5:30; Thurs 9-8; Sat 9 3

fl^ ViCAS & CLiARWATtR ifofes nor opf n Thursday evf^nings^
E-X-P-A-N-0-E-D WATS PHONE HOURS

Our MILWAUKEE Headquarters wilJ answer tfie Nationwide WATS line
1 -800-558-0411 until 8 pm {Milwaukee time). Monday thru Thursday

Call Toll Free: 1-800-558-0411

Inc.

WICKLIFFE. Ohio 44092

28940 Euclid Avenue

Phone (216) 585-7388

Ohio Wats 1 800 362-0290

OutsideOhio 1-800-321 3594

ORLANDO Florida 32803

621 Commonwealth Ave.

Phone (305) 894-3238

Fla. Wats 1 800 432 9424

Outside Fla 1-800-327-1917

LAS VEGAS. Nevada 89106

1072 N Rancho Drive

Phone (702) 647-3114

Pete. WA8PZA & Squeak. A07K

Outside Nev 1-800-634-6227

ERICKSON COMMUNICATIONS

CHICAGO. Illinois 60630

5456 N. Milwaukee Avenue

Phone (312) 631-5181
Outside ILL. 1-800-621-5802

In WIteontin (ouitldt MHwmukaa Uatro Ana)

1-800-242-S1 95

4828 W. Fond du Lac Avenue; Milwaukee, Wl 53216 - Phone (414) 442-4200

AES BRANCH STORES ASSOCIATE STORE

73 Magazine ■ February, 1982 63

Kart T. Thurber, Ir WBFX
117 Faptar Drive
Mittbrook AL 36054

The Art of Listening

audio accessories explored

A high-quatity station receiver having attributes of acceptable sehctivitY, serjsitivity,
stability, image and spurious signal re/ectfoa and accurate readout forms the heart of any
installation --amateur or SWL Due to cost considerations, front-panel control space limita-
tions, and other factors, not all desirable features can be included. In this article, we look at
important audio-related accessories that can be used in tandem with a good set for
outstanding performance and versatility. These include proper headphones and speakers,
audio filters, and tape recorders. The front-panel phone jack provides the umbilical con-
nection for these devices. The Kenwood R-1000 receiver pictured here has one interesting
feature of special interest to SWLs: The function switch at upper left controls a timer used
to turn on the radio for scheduled listening or to control a recorder through a remote ter*
minai (Photo courtesy of Trio-Kenwood Communications, Inc.)

M 73 Magazine • February J 982

In this interesting and high-
ly-readable article, WBFX
highlights in a casual, non-
technical way some impor-
tant considerations in
choosing key audio acces-
sories for your station.
Whether a licensed amateur
or a serious shortwave lis-
tener, we think you will be
interested in what he has to
say about speakers, head-
phones, tape recorders, and
filters for the ham shack.

No transceiver or re-
ceiver is perfect, and
none comes complete with
all possible accessories to
fill every operating need.
The design of such a radio
would certainly push the
technical state of the art,
not to mention that it
would most certainly be
cost-prohibitive. Various
accessories and modifica-
tions narrow the gap be-
tween needs and reality and
allow one to tailor perfor-
mance accordingly.

There are many receiver
audio add-ons one can
build or purchase: external
speakers, headphones, tape
recorders, audio interfer-
ence filters, phone patches,
radiotetetype (RTTY) and
Morse code readers, slow-
scan television (SSTV) view-
ers, and monitorscopes, to
name but a few perfor-
mance-enhancing accesso-
ries.

In this article, we will
look at construction and se-
lection considerations for
the first four groups listed
above. Our review will high-
light a number of commer-
cial phone-jack products
from the standpoint of their
contributions to material
reception improvement
and making on-the-air oper-
ating a more convenient
and enjoyable pastime.

Let's begin with the main
link between your rig and
your ears— the speaker.

Speakers: A Special Breed

Anyone who rates him-
self or herself a hi-fi buff
knows just how important
the speaker is to overall au-
dio system performance.
Unfortunate (y, the speak*
er's importance to receiver
or transceiver performance
is too often forgotten— by
the individual ham and by
manufacturers as welL
Most amateur equipment
made today, whether of
domestic or Japanese orh
gjn, contains but an under-
sized, inexpensive, and in-
adequate loudspeaker This
results in poor audio perfor-
mance from otherwise ex-
cellent equipment. Defi-
ciencies are magnified
when equipment is stacked,
since the speaker is normal-
ly mounted on the top or
bottom of the radio where
its output will be muffled
by the operating desk or
other equipment above or
below the radio.

Most radios have provi-
sions for using an externa!
speaker, and I recommend
you use one to help attain

the overall performance

you expect from your set.

Fixed station external
speakers. It's a good idea to
obtain the matching acces-
sory speaker at the time of
the receiver or transceiver's
purchase. However, you
should be able to use al-
most any communications
speaker as long as the voice
coil impedance matches
that of your sets output,
normally 8 Ohms [4-16
Ohms is the usual range].

Only a commun/caf ions-
type speaker should be
used, however, as the re-
stricted frequency response
of these units is optimized
for speech reproduction.
Hi-fi speakers, though per-
haps of superior overall
quality, will unduly accen-
tuate any low-frequency
hum as well as high-fre-
quency noise and back-
ground hiss.

Of late, I've observed
that accessory speakers of*
fered by some manufactur-
ers are marginal in size and
quality; hooking up one of
these units will not produce
the improvement one
would expect from an exter-
nal speaker. A possible rem-
edy is to scour the next
hamfest or swap meet for
one of the 8- to 12-inch
boat-anchor speakers of the
1950s and 1960s bearing
such names as National
Hallicrafters, Collins, and
Hammarlund. These units,
if in good condition (voice
coil intact and speaker
cone undamaged], will run
rings around the 4- to 5-inch
jobs seen today. A little
clean-up, and possibly a
paint job, will do wonders
to restore a unit to respecta-
bility.

You can "roll your own''
versions of these increas-
ingly difficult-to-find ac-
cessory speakers, too; your
effort will likely be reward-
ed with superior speech
quality and intelligibility.
Send for the catalog of
McCee Radio and Electron-
ics, 1901 McGee St., Kansas
City MO 64108. It's chock

[■•■■■I

An external speaker is a near-must in view of the minimal
speaker usual ty provided in most amateur gear produced
today. The Kenwood SP-180 shown here is designed for use
with the 75-780 series of gear; it has a few "'belts and
whistles^' of its own. These include three selectable tone
filters and two-channel selectable input The headphone
output can be routed through the tone filters, too.

full of speaker and enclo-
sure possibilities at moder-
ate prices. Select a 6-inch-
diameter or greater unit
that will handle 5 to 10
Watts of audio power.

For the experimentally
inclined brasspounder. Sky-
tec offers an unusual de-
signed-for-application CW

speaker- This acoustically
tuned unit develops virtual-
ly single-stgnaf selectivity
for excellent Morse recep-
tion. The CW-I combines an
acoustic filter resonant at
about 750 Hz with a loud-
speaker in a small enclo-
sure; a sleeve in the output
opening may be extended

SJi^ytec CW-1 speaker is an unusual device that is expressly
designed for receiving CW radiotelegraphy. The unit com-
bines an acoustic filter resonant at about 750 Hz with a
loudspeaker to closely approximate "single-signal'' selec-
tivity. (Photo courtesy of Jim Bowles W6DLCI Skytec)

73 Magazine • February, 1982 65

HDP 1228

Mobile instal fat ions can benefit most of all from a
carefully-chosen and proper/ y-rmta//ed external speaker.
Built-in speakers found in most HF and VHF/UHF mobile
sets are inadequatety sized and positioned to compete with
road noise, car sounds, and passenger chatter Inexpensive
CB-type units usually work welt or a special ly-designed
unit such as this Heathkit^ portable twin speaker can be
used. Unit includes a visor mount to help direct sound
downward to overcome road noise. (Photo courtesy of the
Heath Company]

to varv the resonant fre-
quency slightly.

How does it work? In the
Skytec speaker, back radia-
tion fronn a vertically
moLinted loudspeaker near
the base is deadened by
sound-absorbent materraL
A cylindrical sound cham-
ber (tube) is coupled to the
front of the speaker
through only a small hole in
a plate that otherwise clos-
es the lower end of the
tube; the tube's upper end
is open to the room. At the
frequency at which the
chamber length is acousti-
cally one quarter wave
long, it is resonant and acts
as a matching section be-
tween the high impedance
fto sound) of the small hole
at the speaker end and the
low impedance to the room
of the open end. Audio en-
ergy transfer is very effi-
cient at this frequency but
it falls off sharply off-
resonance.

Using this special-pur-
pose speaker desired sig-
nals can be peaked consid-
erably (on the order of
about 20 dBl while adja*

cent channel signals still
can be heard in the back-
ground. This feature allows
the band to be conveniently
scanned without the need
to switch back to the regu-
lar station speaker. The
speaker can be used in con-
junction with standard in-
termediate frequency (j-f)
filters and narrow-bandpass
audio-frequency (af) filters,
as well However, the filters
must be compatible; that is,
bandpasses must be cen-
tered on the same frequen-
cy. Thus, other filters may
or may not be used to ad-
vantage with the CW-1, de-
pending on whether their
peaks may be set such that
the audio pitch that results
is within the speaker's re-
sponse capability.

You also may want to
route your radio's output to
a remote location such as
the workshop, patio, bed-
room, or yard. A general-
purpose PA type speaker
(weatherproof for outdoor
use) will usually fill the bill.
It's advisable to allow
switching between the in-
shack speaker and the ex-

tension, and also for sepa-
rately controlling the vol-
ume on the remote speaker.
An FM wireless mtke mod-
ule also may be used to
broadcast received signals
to any standard FM receiver
in the home or around the
yard — more on this possi-
bility later.

You may have noticed
that many of the bells and
whistles now standard on
the latest transceivers and
receivers are finding their
way into accessories of all
kinds. For example, the ex-
ternal speaker for my Ken-
wood TS-180S is not iust a
speaker, but a triple audio
filter, audio distribution
point, and headphone jack
box; it can handle the out-
puts of two receivers, or a
receiver and a transceiver
The two af filters are fixed-
tuned and push-button-se-
lectable to attenuate either
low-frequency (below 400
Hz) or high-frequency (1.5
kHz or 3 kHz up) signals.
The headphone output is
switchable through the fil-
ters, as is the output from
either audio source A line-
out jack on the rear apron
provides a convenient
source of filtered audio for
RTTY^ SSTV, monitorscope^
and other applications
where receiver audio is re-
quired.

The speaker's fixed filters
can't compete with sophis-
ticated "active" audio
filters, but can do a good
job augmenting existing t-f
filtering. The narrowing of
the af bandwidth to at-
tenuate the noise compo-
nent after i-f processing can
materially enhance recep-
tion.

Speakers for the mobile
rig. Practically all mobile
amateur transceivers con-
tain small internal speakers.
The harsh sound and re-
stricted size and range of
most puts a crimp in the
quality of reception of all
signals. Although many ra-
dios have the speaker in-
stalled on the top of the rig
so that the driver will hear it

best, most sets aim the
speaker downward — the

worst possible direction.
The set's full audio output
is directed where it is large-
ly absorbed by floor mats
and carpeting. Even with
solid-state equipment,
cranking up the audio gain
to overcome road noise and
passenger conversation can
result in microphonic-type
squeals from the transceiv-
er due to acoustic coupling
back through the rig's in-
nards.

Thus, even more so than
in fixed-station operation,
an external speaker is clear-
ly desirable. Extension
speakers markedly improve
intelligibility when posi-
tioned and aimed better
than the rig's internal
speaker and will probably
be more efficient than the
set's speaker. This fact
allows the transceiver's
usual 2- to 3- Watt audio
stage to be throttled back,
resulting in less overall
distortion — a real problem
with some of the less-
weighty mobile rigs, par-
ticularly handie-talkies.

A hi-fi speaker, such as
that used for automobile
F M/ A M/t ape-deck use,
should not be used for the
same reasons discussed pre*
viously. Instead, a 1- to
5-Watt communications-
type speaker should be pur-
chased, one designed ex-
pressly for the speech
range, 300 to 3000 Hz or so.
An inexpensive source of
this kind of speaker is the
CB market still flooded
with a mass of unsold ac-
cessories as well as two-way
radios The quality of CBr
type units varies all over the
spectrum, but with speak-
ers sometimes going for $4
to $5 at discount and parts-
store sales as well as ham-
fests and CB coffee breaks,
it's not too much of a risk to
try one out. Other sources
of quick-and-easy mobile
speakers are the small
speaker boxes which are a
part of many telephone am-
plifiers, such as the Radio

66 73 Magazine • February, 1982

SUPER STICK II

2 METER 5/8 WAVE TELESCOPIC ANTENNA

6-9DB

over a Rubber Duck

Available In
95 BNC, TNC, Tempo S-1,

Motorola and F Type
Connectors

SUPER
STICK

BRAND
C

BRAND
V

PRICE GAIN • CONNECTOR

$19.

S26.

S24,

6-9 DB

6-9 OB

5-6 08

BNC-Tempo
5/15-32
TNC-F— 50239

BNC ONLY

FULLY
COLLAPSED

Collapsed is a
matched 1/4
Wave Antenna

WiH no\ iran*mii

Win not trafisJTUt
id cDlI^psed position'.

* Measured Field Strength Over Rubber Duck
*• Specify Base Type BNC. Tempo, Ect.

The Tuned Antenna Company brings you the Super Stick M
for those long hauls with your H,T., plus our 5/8 Wave
Antenna may be operaied collapsed with the same operating
characteristic of a Rubber Duck Antenna The Super Stick II
IS avarlable with Tempo S-1. BNC-TNC-F-PL-259 Bases at a
price that is several t>ucks under other 5/8 Wave Antennas,
making the Super Stick II the best buy around. See your local
dealer for stock. Settle for nathing less than a Super Stick II

FOR DEALER LOCATJON

OR TO ORDER CALL:

(714) 268-0720

V^A

GO.

^Bj

1C-«AT

9520 Chesapeake Dr. #603
San Diego. California 92123

MFJ KEYERS

Uses Curtis 8044 IC. Iambic
operation, dot-dash memo-
ries, weight control, solid
state keying. RF proof*

The MFJ-40B Deluxe Electronic Keyer s^nds
iambic, automatic, semi-automatic, manual. Use
squeeze, singie lever or straight key.

Speedmeter lets you read speed to 100 WPM.

SiKket tor £?(tenial Cyrtis memory, random
code generator, keytoard, Opfional cattle. $4 9S,

lamtiic operation with squeeze key Dot liash
insertion Semi-automatic "hu^*' operation pro-
vides autfHBatiL vuis aiMl manual dast)6S.

Dotdash memoryt self completing dots and
[iashes, lam proot spacing, insfeni start RF prtjol,

S^lid' state keying: grid block, solid slate ^mtrs.

Front parcel controli: Tinear speed, weight,
tone, voJume, function switch. 8 to 50 WPM.

Welghl control adjusts dot dash space ratio;
makes your signal distinctive to penetrate ORM.

Tone control. Speaker. Ideal lor cfassroom.

Function swilcti selects ofl. on, somi automatic/
manual, tune. Tune keys transmitter for tuning

Uses 4 C'Cili. 2,5 mm jack lor power (6 9
VDCi Optional AC adapter MFj-1305. $9,95

Eggshell white, walnut sides. 8x2^6 inches

MFJ-406. S69.95» like 40S less speedmeter.

$49

New MFJ*401 Econo Keyer II gi^es you a
reliable. M\ feature economy keyer lor squeeze.
single fever or straight key.

Has sidetone, speaker, volume, speed, Internal
weight and tone controls. Sends iambic, auto-
matiCn semi automatic, manual. Tune function.
Dot-dash memories. 0 50 WPM. "On" l£D. Use
9V battery. 6 9 VOC, or 1 1 0 VAC with opttofial
AC adapter, MFJ 1 305. $9 J5. 4K2x3Vr,

Refiable soTId state keying. Keys v^noalty all
solid stale or tutie type transmtlters

MFJ-405'Econo Keyer f1. Same as MFJ 451
but has hmWm single paddle with adjustable
tra^eJ. Also jack (or external paddJe 4x2x3Vg'V

Optional: Bencher Iambic Paddle, $42.95;
110VAC adapter, MFJ- 1305, $9,95. Ffge catalog.

Order from MFJ and try il. If not deltghted.

return withm 30 days for refund (less shipping^.
One year unconditional guarantee.
Order yours today. CaU toU fret 300-647*1 SDO.

Charge VISA, MC Or mail check, money order.

Add S4 00 each tor sfrppping and handling

CALL TOU FREE . . . 800-647-1800

Call 601 323*5869 loi technical infonnatw, qr
der^repair slalus. Also call 601 323 5869 oul-
sirJe continental USA and in Mississippi. ^^47

lUIB I ENTERPRISES,

IWirV INCORPORATED

^ BOJ< 494. Mississippi State. MS 39762^

t^Bee List of Adverrisers on page 1 M

73 Magazine * February J982 67

Shack 43-230 and similar
units. Though small, these
units seem to be adequate
for casual FM-style mobile
work. Old police or taxicab
speakers in good condition
also can be used.

For the operator who
likes to occasionally use his
handie-talkie in the family
buggy. Heath's HDP-1228
clip-on sun visor speaker is
a good bet. The 7-oz. dual
speaker has two large
mounting fingers (similar to
those used on visor mirrors)
to hold the speaker onto
the visor just above the
driver's head. This method
of mounting allows opti-
mum positioning of the
speaker to direct the sound
downward where if s need-
ed to overcome road noise.
An eight-foot-long cord and
mini-plug allow easy con-
nection to the HT or any
other mobile transceiver.
(This item, manufactured
by Superex Electronics
Corp., may have been dis-
continued by Heath, as I
haven't seen it advertised in
recent catalogs,)

lust about any CB4ype
external speaker will yield
adequate results. However,
there is one new amateur
unit on the market that war-
rants mention; the Ken-
wood SP-40. This is a com-
pact, but high-quality, light-
weight (.44-lb,) speaker hav-
ing a power handling capa-
bility of 3 Watts with a fre-
quency response of 400 to
5000 Hz. Although speaker
size is only 57 mm, the little
unit appears to be quite ef-
ficient and free of annoying
resonances and vibrations
that too frequently plague
lesser CB counterparts The
speaker leg has a magnet so
that it easily can be mount-
ed on any magnetic sub-
stance. If the speaker is to
be installed in a location
where the magnet can't be
used, mounting screws or
double-faced adhesive tape
also can be used. Some-
what on the expensive side
[about $25), the unit never-
theless represents good

value (I own two, one for
each automobile). The
speaker's aircraft-instru-
ment styling makes it an es-
pecially attractive comple-
ment to any mobile installa-
tion.

Headphones for
the Ham Shack

Loudspeakers are great
for armchair-copy SSB work
and for casual, FM-style op-
erating. But there are a
number of advantages in
owning and using a good
set of headphones as an ad-
junct to the trusty station
speaker.

Many DX signals are too
weak and QRM-obscured
to be properly copied on a
loudspeaker; a good set of
phones will be of consider-
able value in increasing
your ability to pull weak
and near-buried signals out
of the pack, particularly on
CW. Room, household, and
outside distractions also
will be markedly reduced,
allowing maximum concen-
tration on the signal being
copied. The overall effect
of using headphones can be
about equivalent to dou-
bling received signal
strength, when compared
with straight loudspeaker
listening. This may mean
the difference between a
solid DX contact and none
at all.

A secondary, yet impor-
tant, reason for using head-
phones is that the phones
isolate the ham shack from
the rest of the household,
whose members may not
appreciate the objection-
able whistles, squawks, and
other noises that are music
to the ham's ears. This is
especially important when
practicing code, since
Morse blasting forth at 750
Hz can have a very shrill
and unnerving quality that
readily penetrates wails,
ceilings, and floors — not to
mention people! Apart-
ment and condo dwellers
are well aware of how un-
popular Morse can be with
the neighbors.

. 0-> .:.:.uB.iuv>X'C°0^:

/ built a small FM rebroadcaster for cord-free headphone
monitormg /n my ham shacL The unit shown uses the
100-mW Ramsey FM module, which easily can be tuned to
a clear spot on the FM band. Output of the station's
TS-WOS, FRC'7, or R-1000 is fed through the Autek Re-
search QF-1 audio filter to the FM unit. A pair of lightweight
''radio headphones'' completes the installation.

Communications phone
requirements. Many begin-
ners start out by appropriat-
ing the closest set of stereo
hi-fi phones for their rigs,
with little thought of wheth-
er the unit can do the job.
Most decent stereo phones
can be used, but because
they are designed for high-
fidelity reproduction, their
wide frequency response
may elevate internal receiv-
er hum and noise to an ob-
jectionable level; also, some
lead-switching needs to be
done to adapt them for
monaural use.

Far better, and a more
suitable investment for a
lifetime amateur radio ca-
reer, is a good pair of com-
munications-type head-
phones. Such phones wilt
boast a relatively narrow
frequency response, high
sensitivity, and easy physi-
cal adjustment. They also
will be designed for com-
fortable wearing over ex-
tended periods, and the ear-

muffs will be effective in
isolating the operator from
distractions. Several manu-
facturers sell communica-
tions-type phones, includ-
ing Telex, Superex, Radio
Shack, and Amplivox. Ma-
jor ham gear manufacturers
such as Kenwood and
Yaesu offer a selection of
radio headphones designed
to both physically and elec-
tronically match their
equipment lines.

Several considerations
emerge. Input impedance
should match the output
impedance of the receiver
or transceiver's audio stage.
In almost all solid-state am-
ateur gear this is low imped-
ance, in the 4-tCh16-Ohm
range; normally, 8-Ohm
headphones should be ob-
tained, though lower-im-
pedance units will probably
work nearly as well Some
older ham gear was de-
signed for high-impedance
phones, usually Ik to 5k
Ohms, however; imped-

68 73 Magazine • February, 1982

Ik>

. ^ I iVa^ 3" k-t- ri -r

'Hfn'i-ir-P."!^'^

■MiTYJfcllll"

Transmits perfect Morse Code * Built-in 16
cliaracter buffer * Internat speaker and sid$-
tone * Reed rejay output eliminates i<eying
problems * All solid state circuits and sockets
for reliability * Speed range 5—45 WPM * Perfect
companion to our MORSE-A-WORD CW code
reader.

MORSE-A-KEYER KIT, model MAK^K, Complete kit of parts & manual . , . .

MORSE-A-KEYER, model MAK-F, Factory wired & tested . » . ,

MORSE-A-KEYER ESSENTIAL PARTS KIT, model EPK-K.

(Essential parts kit for home-brewers consists of pc Jaoard, board parts and manual.
You suppty ASCII keyboard, cabinet, power supply &^ miscellaneous parts.)

Send check or money order. Use your VISA or MasterCard, Add $5,00 shipping and
handling for Continental U-S. Wlsconspn residents add 4% Wisconsin State Sales Tax.

$159.95
S199.95
$ 69,95

1^50

"TMioto^ta^

Corporation Telephone; (414) 241-8144

Post Office Box 51 3G, ThiensvHle, Wisconsin 53092

QRP Comer

Kits

IN STOCK

BiW coils, switches, antennas
Jackson dials and drives
J.W. Miller parts
Miljen compc^nents
Multfonics roller Inductors
Toroids^ cores, beads, baluns
Variable capacitors

Cardwell— E,F. Johnson
Hammartund— Millen

Fun OscJIlator {73 £/82) 80 or 40 Meter, VFO for Fun-

Miner

40 Meter Transcselver |hr At^) 40 Meter, 1 watt output

lAHU Transmitter (QST 12/78) 20 Meter, 6 watt output

lARU Receiver (QST 4/76) 20 Meter

PC Boards ^

Fun Mltter {73 2/01) 80 or 40 Meter, 5 watt output

Fun-Celver {73 7/B1) 80 or 40 Meter

Boots for the HW^ (QST 4/73) 80-15 Meter 10-12 watt

output

454

Catalog — 25 cents

RADIQMr

8d)i 411 S, Gre«nvm», NH 0304fl
(803) S78>10a3

THELASTWORD
READERS

THENEW

FEATURES:

• 32 CHARACTERS FOR EASY HII3141SPEED COPY
OF MORS!

• ASCII and BAUDOT RTTY

• NO RECEIVER MODIFICATION NECESSARY

• INSTANT SPEED TRACKING FOR MORSE CODE
OVER WIDE SPEED RANGE FROM 2 TO 99 WPM

• OPERATES FROM 12 \^D.a

R>r AEA Headarf or other
AEA Products, call or visit:

AEA

Brings you the
Breakthrough!

C + A ROBERTS, INC.
22010 So. Wilmington Ave.
Suite 105 Carson, CA 90745
CALL: (213) 834-5868

MFJ SWR/
WATTMETERS

HF SWR/Wattmeter
reads SWR, forward, reflect-
ed power from 1.8-30 MHz.

MFJ-814

New low cost in-line HF SWR/Wmtmeter.

MFJ-614 lats yau monitor SWR, forward,
reflected average power in 2 ranges from 10
to 30 MHz. Read 200/2000 watts forward.
20/200 watts reflected power. SWR, 1:1-6:1.

Easy pusli-button switch operation: has power/
SWR, high/low range, torward/refteded push-
button switches. SWR sensitivity control.

Lighted mefer [requires 1 2V). Rugged alumi-
num eggshell whfte, black cabinet. 5V4x3V4x4V^",
SO 239 coax connectors, 2 color meter scale,

MFJ VHF SWR/Wattmeter/
Field Strength Meters

$0095

MFJ-812

hmm,

New Fdw cost VHF aperating aids.

MFJ-&12, $29.95: Read SWR from 14
170 MHz to monitor antenna and feedilnes.

Read forward and reflected power at 2 meters
(144.146 MHZ). 2 scales (30 and 300 watts).

Read relative field strength from 1 to 170
MHz, Binding post for field strength antenna.

Easy push^butten operations has farward/re-
flected and SWR/tiefd strength pushbultons.

Atummum eggsliell white, black catiinet.
4V4x2V-ix2V4", SO-239, 2 cotor meter scale.

MN-S10, S24.95: similar to (VlFJ-812 less
fietd strength function.

MFJ "Dry" 300 W and
1 KW Dummy Loads.

$g495g^||gl$26^''

MFJ-262 ^mtf^ ^^^ MFJ-Z60

Air cooled, non-inductive 50 ohm resistor in

perforated metal housing with SO 2 39 connectors.
FuH load for 30 seconds, de-rating curves to
5 mhutes. MFJ-260 (300 WJ. SWR; 1 1:1 to
30 MHz. 1.5:1 for 30-160 MHz. 2V^x2V?x7".
MFJ-26Z (1KW). SWR 1.5:1 30 MHz 3x3x13'.

MFJ^IO. 3 foot coax with connectors, $4.95.

Order from 1VIFJ and try it. If not delighted,
return within 30 days for refund (less shipping)

One year uncondittenal guarantee.

Order yours today. Call toll free BOO 647-1800.
Charge VISA, MC. Of mail check, money order.
Add $4.00 each for shipping and handling.

CALL TOLL FREE . . . 800-647-1800

Call 601-323-5869 for technical infonnation, or
der/repair status. Also call 601 323 5869 oitt-
side continental USA and tn Mississippi t^ 47

nil B I ENTERPRISES,

IWirV INCORPORATED

Box 494, Mississippi State, MS 3S762

See List of Advertisers on fiage 114

73Magaztne ■ February, 1982 69

A good pair of headphones will last a lifetime of hamming.

Though communications-type phones are usually recom-
mended, high-quality stereo headphones are often pre-
ferred because they usually sport extra'Soft, oversize
cushions and padded, adjustable headbands. An adapter
cord or plug would be required to convert a stereo phone
such as this Radio Shack unit for monophonic use with your
receiver or transceiver. (Photo courtesy of Radio Shack)

ance matching is more criti-
cal in such instances. Most
military surplus head-
phones, often attractive be-
cause of their rugged con*
struction and oversize ear-
muffs, are 500-to-600-Ohm
units, though they are
sometimes seen in higher-
and lowerHmpedance ver-
sions.

Sitting in front of a ham
rig for many hours at a
stretch is fatiguing. Doing
this while wearing an un-
comfortable set of head-
phones, sporting a tight and
close-fitting headband, is
torturous. For reasons of re-
taining one's sanity and a
pleasant disposition, it's
critically important to pur-
chase earphones having
good earmuffs; the muffs
keep the signal in and dis-
tractions out. Thick, but
soft flexible pads are what
are required; they should be
held fairly tightly against
the head by the headband's
pressure, though not so
tightly as to be noticeably
uncomfortable. One should
be careful in purchasing

used headphones, even !f
they're OK electrically, be-
cause old earmuffs even-
tually become shopworn
and stiff, primarily due to
their having been soaked in
the operator's perspiration.
Deterioration of the high-
frequency response is the
result, along with a reduced
isolation ability. Overly
large, heavy headphones
should be avoided due to
the discomfort caused by
carrying their weight over
an extended period.

Some features to look for
include a coiled cord, ir^
dividual headset volume
controls, interchangeable
or easily-replaceable ear-
muffs, type of headband
construction (single, dou-
ble, padded, etcl and a
means of adjusting the
headband. These factors
may be either pluses or mi-
nuses, depending on indi-
vidual operator prefer-
ences.

I have found that buying
headphones is one task that
is best done in person, not
by mail. It's important to try

out the phones, if possible
with the radio with which
they will be used, both from
the standpoint of equip-
ment compatibility and op-
erator comfort. All the
printed specs in the world
are useless if you can't
comfortably wear the
phones over a long time^
span. If possible, borrow
several different phones
from friends and check out
their suitability in your own
station before making your
choice.

Except for mobile work,
where a single headphone
may be worn in conjunction
with a boom mike/headset
combo, a pair of head-
phones is universally used.
Since the human hearing
system tends to cancel out
noise which is applied
equally to both ears, adding
the second headset allows
recognition of signals sever-
al dB lower in level than
with a single headset. Also,
most people do not have
equal or symmetrically bal-
anced hearing in both ears;
dual phones tend to mini-
mize this anomaly.

A few headphone operat-
ing tips should prove help-
ful:

1) Try using a pair of fit-
ted earplugs under the
headphones. Desired sig-
nals will come through the
earplugs fairly well, while
noise will be suppressed.
Using earplugs is particular-
ly effective when working
on an extremely noisy band
for a long stretch. You abo
may find fatigue is reduced.

2) Experiment with revers-
ing the audio leads to one

headphone. The human ear
tries to cancel out noise
which is presented irnphase
to both ears; swapping the
normally in-phase headsets
can produce a substantial
readability improvement
while letting the signal of
interest through with mini-
mum impediment- If results
are favorable, you may
wish to install a switch to
conveniently reverse phase
for routine listening.

3) Learn to "ride gain" on
your set's rf and af gain con-
trols, avoiding "blasting/'
which will have the tempo-
rary but undesirable effect
of desensitizing the ears.
Generally, best CW copy is
had by running with the af
gain wide open (or nearly
so) and working with the rf
gain control, keeping levels
low enough to avoid receiv-
er and headset overloading,
A good receiver age system
makes doing this a lot easi-
er.

4) When operating on
CW, carefully adjust the
set's main tuning or beat
frequency oscillator [bfo, if
the set has one) to produce
a strong yet pleasant audio
tone. Don't opt for a too-
low pitch; around 750 Hz is
usually about right, give or
take 100 Hz, or so.

5) If you're an inveterate
SSB contester, consider the

use of a boom mike/head-
set combo. This device re-
places, or supplements, the
transceiver's existing mike
and speaker. The boom is
attached to the back of one
of the headphones and
curves around the opera-
tor's cheek, thereby posi-
tioning the mike directly in
front of the mouth for
close-talking and essential-
ly hands-free operating. A
press-tCHtalk [PTT) switch is
part of the cord itself,
though most boom-mike as-
semblies can be 'hot-
wired" and a foot-switch
used for PTT switching for
true hands-off operation.
Use a double-headset type
for fixed-station operation
and ensure that mike and
headphone impedances are
right for the transceiver or
receiver/transmitter pair
with which the combo is to
be used. Avoid cheap CB-
type boom assemblies like
the plague!

6) If you want to try cord-
free headphone operation,
purchase a pair of light-
weight, cordless FM radio
headphones — the kind that
has a built-in FM or AM/FM
radio inside the headphone

70 73 Magazine • February, 1982

RTTY/C\A/

For theTRS-BD

* A TradeiTiarR at !he t&nOY Corp

ROM-116

RTTY/CW Operating System

Detailed brochure available on requQsL

Featuring:

1200 BAUD OPERATION. Not limited to 1 10 baud be-
cause of timmg loops. 60, 66/75 & 100 W, P.M.
Plus 110, 150. 300. 600 & 1200 t}aud operaliofis
possibie.

FLEXABILin OF OPERATION. Instantly cnange Baud
Rates; Program Mode (ASCII/baodot): Program Status
SPLIT SCREEN VIDEO. Transmit & receive data dis-
played separately.

REAL TIME. Automatic CW/ID without user interven-
tion. Automatically updates \^^^ roj^t
at end of montt^ or year. ^^5 CBOulCI

nicroProducts

Other features
include:

• Two Sfif lai Ports
Fourteen Buffers

- Automatic CW ID
Transmit Control

• Selective Call Feature

• Errof Correcl^on

• Word Wrapping
Easy To Interface
30 Day Unconditional Guarantee

I Hardware requifements. TRS-80
Model! or 3 16K
External terminal unit.

606 Sl^te Street, P.O. Bom 892-R • MarYsvdle. WA 98270 • (206) 659-4279

... at last . . .
i;our shack organized!

A beautiful piece of furniture — your XYL will love iti

$16450 S-F RADIO DESK

Deluxe - Ready to Assemble

AJftO Available
Floof S{iac«; 51" Wide by 30" Oe^p

Designed with angled rear shelf for your
viewing comfort and ease of operation

FINISHES: Walnut or Teak Stain,
Floor Spica: 39 ' Wide by ^'^ Owp

AMttionar Information on ^h&qiiest-

Ch«ck3, McH^ Orders. BankAnieficard
and Master Charge Accepted.

FO.B. CuW^T Gtty. iln CaJil A44 6% Sales Tax ^

, DEALER INOUIRreS INVITiD

*^65

4364 KEYSTONE AVENUE * CULVER CITY. CALIF. 90230 - PHONE (213) 8a7-4fl70

'over 70 iRAHDSWLAND-MOBILE^
IN STOCK O RADIO

AMATEUR

Full Service Shop •Specfrum Analysis * Antennas
New and Used Eqyipment •CW-SSB-FM. Etc. •Towers
FCC Study GuKies •Code Tapes •Books •Accessories

■COM

SHORTWAVE

CLOSED

SUNDAYS.
HOUOAYS

HOURS

MDNJUES, WED.
9:30-6:00 PM

THUDS, m.:
9:3O'S:00 PM

Specialists in Amateur Radio,
Short-Wave Listening
And Contemporary
Electronic Gear.

SAT 9:30-3:00 M*

4J:m;i[.i.-

1D09 dARFlEiO ST OAK PAflK^ IL 60304

(312)848-6777

MFJ

SHORTWAVE

ACCESSORES

NEW Indoor Tuned Active
Antenna. Rivals, can even
exceed reception of out-
side long wire.

Rivals long

MFJ-1Q40 BECEJVER PIlESElECJOIi. Improves
weak sigi^ar reception, rejects out of band sig
nais. reduces image resijons^, 1 8 to 54 MHr
Up to 20 d& gam. Low fio^se MOSFET. Gain
control. Bandswuch. Can use 2 ant.. 2 rcvrs,
ON OFF/Bypass, 20 db attenuator. LED. Coax,
phono jacks. 8x2x6 in. Also lor XCVRS to 350
watts input. Auto bypass Delay control. PIT
lack. MFJ-1045, $69,95, Same as MFJ 1040,
less attenoator. Kcvr auto bypass, delay control,
PTT, Use 1 am. 1 fcvr. 5x2x6 in, 9V bat. Both
requifes 9*18 VOC or 110 VAC with optional

AC adapter. S9.95

$Q095

— '— - ~^^='^'-itim — r

MOBJLE SWL COIiVEHTERS to hear the shor^
wave world while you drive. MFJ-304 (169.95)
covers 19, 25, 31, 49 meter bands. MFJ-aOS
(S89,95) adds 13. 16< 41, 60 meters. Two
dual gate IVIOSFETS give excellent sensitivity,
selectivity with car receiver Push button band
selector Tune with car radio. Plugs betweeii
antenna and radio 12 VOC, 304 is 5V<x1V4x4".
308 is 6V4XI V«x5", Fme catalog.

MFJ- to, Z tool coax with cofinectors. $4.95.

Order from MFJ ind try Ji II noi delighted,
return wittiin 30 days tor refund (less stripping)

One year uficondilioftal guarantee.

Order yours today. CaH (off free aOO 647-1800.
Charge VfSA, MC Or mail check, money order
Add £4,00 each for shipping and handling.

CALL TOLL FREE . . . 800-647-1800

Carl 601 '323-5869 for technical information, or
der/refiair status Also oall 601 323 5869 ojt
side continental USA and m Mississippi- ^4?

UEr I ENTERPRISES,

IWir^f INCORPORATED

Box 494, Mississippi State. MS 39762

MFJ-iaZO HEW INDOOR ACTIVE ANTENNA
sits on your desk ready to listen to the world,
Rivals, can ojten e>cceed. reception of outside
long wire. Unique Tuned Active Antenna mini
mizes intermod. provides RF selectivity, fe
duces noise outside tuned tsand. Also use a:
preselector for external antenna. Covers 300
KHz to 30 f^Hi m live bands. Adjustable tele
scoping antenna, ContTols: Tune. Band Selectw,
Gam. OnOtif/Bypass. LED. FET, bipolar circuitry.
Phono jack tor eKternal ant, 6x2x6 rnches.
912 VOC or 9 V battery for portabfe use
110 VAC with optional AC adapter, $9.95.

p'Stfe Ustof Acveftis^fs on p^ge 1 14

73MagazinB • February, 1 982 71

itself— and feed your rig's
output to a small wireless
FM broadcaster module.
Doing this allows true cord-
free flexibility in the ham
shack by doing away with
clumsy, entangling head-
phone cords. The setup also
has the benefit of allowing
one to monitor band or net
activity anyplace in the
home or yard by tuning in
the rebroadcaster on any
standard FM receiver. Ram-
sey Electronics, 2575 Baird
Rd., Penfield NY 14526,
sells a simple, SOOfoot-
range kit for $335. Food for
thought]

Using stereo phones. We
have cautioned against us-
ing stereo hi-fi headphones
in the ham shack, regard-
less of their quality and
comfortability. Headphones
with extremely wide fre-
quency response character-
istics simply reproduce
additional interference, de-
tracting from desired sig-
nals. Nevertheless, many
hams will wish to use a pair
of existing stereo phones
for reasons of economy or
personal preference. Hands-
on experimentation will
reveal if the pair will, in
fact be suitable for use.

Unfortunately, you can't
just plug a set of stereo
phones into your ham rig.
Almost all such head-
phones use a SQ-cdlled stan-
dard three-conductor (in-
cluding ground) plug, one
circuit being used for each
channel Most amateur
equipment uses a two-cir-
cuit (including ground) jack
for use with monaural com-
munications headphones.
This fact requires replace-
ment of the headphone's
3-circuit plug with a single
circuit plug and the
paralleling of the two
separate leads so that the
receiver's output will be fed
to both headset units. Alter-
nately, the stereo head-
phone's plug can be left in-
tact and an adapter pur-
chased or fabricated to
convert the stereo-config-
ured cord to monaural use.

Using an adapter has the

advantage of allowing the
headset to be used as a
stereo unit whenever de-
sired, without making fur-
ther wiring changes.

If you do purchase a set
of stereo headphones to
use with your ham rig, con-
sider a suitable pair that has
an internal ''stereo-mono''
switch. This feature allevi-
ates the need for an adapter
plug. I own a Calrad 15-135
headset that does a credit-
able job both in the ham
shack and with a small
stereo set and it boasts in-
dividual earphone volume
controls, a coiled cord, and
comfortable muffs

IVe indicated that the
stereo headphones' wide
frequency response may be
annoying when used with
ham gear. This may be par-
ticularly aggravating if you
try to use a pair of stereo
phones in tandem with an
active audio filter, since the
filter may emphasize resid-
ual ac hum and noise pres-
ent in the receiver or trans-
ceiver's audio output You
can minimize this problem
by adding a 50- to 1 50-Ohm,
1/2 -Watt resistor in series
with the headphone lead to
cut down their low-frequen-
cy response and overall sen-
sitivity. The exact value to
use must be determined by
experiment

Tape Recorders

Though by no means
necessary accessories, tape
recorders represent often

overlooked but very useful
station adjuncts. There are
countless practical uses for
recorders, many of which
are suitable for the ham
shack. In fact, many ama-
teurs wouldn't be without
one any more than they
would be sans mike or key:

Ham shack apptications.

Small recorders have a
wide range of applications
in the ham shack that is
limited primarily by the in*
dividual operator's ingenui-
ty and imagination, Record-
ers can be used for such di-

Using a high-qualftY pair of communications-type head-
phones has several advantages. Switching from speaker to
headphones can material ly improve the readabiHty of
received signals and keep distracting room noise out
Lightvi/eight units with soft cushions that are peaked for
communications-range audio are best Low-impedance
models, such as the Yaesu headset shown here, are suitable
for most modern solid*state receivers and transceivefs.
(Photo courtesy of Yaesu Electronics Corporation)

2] Signal reporting. An-
other common use is to pro-
vide ''live'' signal reporting
to others, Most hams are
genuinely surprised to learn
how they really sound over
the air, particularly at a far-
distant location. They are
usually highly appreciative
of an offer to play back
their signal to them as
much more meaningful
than a simple readability-
and-strength report If you
make a practice of pro-
viding on-the-air playback,
keep the engineering prac-
tice up to snuff; hardwire
the connections (no mikes
placed up against the set's
speaker), and ensure that
your wiring arrangements
permit professional switch-
ing between mike and re-
corder. Random bleeps and
fast-forward monkeychat-
ter are not well received
over the air A recorder with
an accurate tape counter is
a near-must.

3} Transmitted signal
quality checking. A good

verse purposes as recoromg
DX and other important
contacts, verifying trans-
mitted audio quality, re-
cording messages and traf-
fic, code practice, making
short CQ and other trans-
mission tapes, signal report-
ing, and SSTV signal orrgi*
nation, to name but a few
popular uses. Let's look at
some of these:

1) Taping contacts. This
represents the most com-
mon, obvious use of the re-
corder. The machine is sim-
ply connected to the receiv-
er's output jack, either
through a Y-plug across the
speaker or, in some sets, to
an auxiliary tape-output
jack- The tapes made can
serve as documentation for
exceptionally rare QSOs
and as a logging aid in fast-
paced DXing and contest
work. (In the latter applica-
tion, a reference time is re-
corded at the beginning of
the tape so that log entry
times can be conveniently
determined.)

72 73 Magazine • February J982

PORTA-PEATER™
INSTANT REPEATER

Command and controJ module mah«$ an milant re
plater from any 2 radios wrlti absolLilely no mod if'
cations to the radios inteirfaces via if>e««1&mal speaker
and m*c lacka P#H©cr »of a pervoriai, ^mer^^ncy. or
rijt«d repeater Wr iie o^ caia tor detailed data many a I We
accept VISA and M/€, Re^u^t cat a tog

• 4 individual CWrOs (IK PfiOM}

• vOX-^COfl, COR Ifiggefs

• Adj. 0-15 min ID cycle timer

• Adj 0-15 min. Time Out timer

• Ad| 0-30 sec hang limer

• AdJ- 20db local mic amp

• True repeater l^nacon. or in any Ml mgd^s
#250 volt switching capability

• C&rnpiete gairv interface cofi trots

• Complete technical irtanuat

• PCBsiieS*^" X 5^.4"

• 22 pin Bdgecard intaffac«

$99.

Assembled,

Testedi
Burned In,
Programmed
(Inc. $3. postage)

W-S ENGINEERING

P.O. BOX 58

PINE HILL. N.J. 08021

24 HR. PHONE: 201-852-0269

MFJ Hybrid Phone Patch

Feature Packed: VU meter. Has receiver gain, transmitter
gain, null controls. Bypass switch. RFI filtered. VOX or push*
to-talk. Works with any rig.

*^MFJ'fi24 TEIEPATCH T - the hybrid phone
palcli with the mosi wanted fealures.

Gi¥es you cnsp clear, hum-fme audio wh^cti ts
wtfat {^hone patehir^ is all aboui Use automaUc
VOX or mafiual push to talk.

VU meter monitors telBptione line levels. Lets
you adjust nijll control for maximum Isolation
between receiver and transmitter.

Separate transmitter and receiver gain conlrols
eltmmate readjustmq ng's controls

Function iwitcti: OFF (or normal operation.
ON connects riQ to plioae Irne for f»3tching,
NULL swit€ties VU meter to adjust for nult.

Simple 2 cable instaiafion (plus phone line)
when rig has patc^ in-patch out jacks. Connects
easily to any ng RFI filters, PC board construc-
tion eliminate RF teedbacN.

Phono jacks for patch-m patcti out, speaker,
microphone. Screw terminals for phone lines. ^

Cr/sp, cfmar hum-frmB audio

im what phonm patching is sH
about and MFJ has rt.

Eggsheti whie, walnut sides, 8x2x6 lm;hes

MfJ-6Z0, S54J5, Same as MFJ624. less
VU meter. 5)f2)(6 inches.

Onfer frotn MFJ and try J1 — no obiigation. it
not delighted, return it wiltiin 30 days tor refund
(less shipping) One year unconditional guarantef?

Order iDday. Gail toJl Iree BOO 647 1800. Chargt;
VISA. f^C or mail check, money order tor $64.95
for MFJ 624 or $54.95 for lVIFJ-620 plus $4.00
each shfDping and handling.

Enjoy quafify phone patctiing, order now.

CALL TOLL FREE .. . 800-647-1800

CatI 601-323 5869 for technical mformation. or-
der/repair status, Afso calf 60t "323-5869 otitside
continental USA and in Mississippi.

ME I ENTERPRISES,

IwirV INCORPORATED

47 Box 494, Mississippi State, MS 39762

1*4 ^^^4*

2 Meter

"All Mode"

Amplifiers

FM - SSB - CVI^

B108 low. m— SOW. oMt
BlOl* low in -^ 16Q W. out
B3016 30 W in — 160 W qui
fi 3 3 3 W. Jn = 30 W. «ui

YEAR

WARRANTY

Parts ond Lnbor
1 yr, on Rf Powar Tr«insisHiri

Peak Reading
WaH/SWR Meters

l»W — HF

1 .1 to 30 mhi

35, 700, 2000

waffi * 5*:^

$119.95

MP? — VHF

SO to 200 mhz
SO. 50O„ 1500

S I 1 9.95

New!! DIO 1 0 430-450
Amplifier

"All MODE" fM-SSB-CW'ATV

$179.95
279.95
339.95

09,95

These amplrfiers, exce|>t 023^ Hay* built in RX prr-
amps. TJrts BIOS and 8(016 may b* used with HU
or franscervtfft. They will key with 1 Wo ft input.

10 w

W. out

RC - ! Remote Control $24.95

SEE YOUR NEAREST DEALER FOR INFORMAtlON
MIRAGE COMM, EQUIP,, INC, * P.O. BOX 1393 ■ GILROV, CA 95020

2 W. in = 25+ W. out
RMAtlON " $319.95

CA 95020 ' (40e} 047-1957

BASSETT HEUUM
MOBILE ANTENNAS

For
Commercial, Amateur,

and Government Seii/ices

Rugged, low drag, high efficiency
mobile antennae engineered lo
mairitain resonance af all times.

Maximum overall hetghl of only
70" , Average weight of only 6 oz.
They remain vertical at all speeds.

HeJicat inductors seated in helium
tilled Fttjergiass impervious to alt
weather. Adjustable l7-7ph wtiips
and ^M brass hardware chrome
plated and polished.

Optimum gam collmears for VHF
and UHF. Unity gajn models for HF,
Amateur band models are inven-
toried for 'off the sheir' delivery.
Commercials to specs.

Write or phone for free brochure
and prices on Basselt mobiles and
Helium Trap Antenna Systems.

REX BASSETT

ELECTRONICS, INC,

1633 NE 14th Ave,. BIdg. 11
Ft. Lauderdale, Fla, 33305
Tel: 305/56 M 400

^440

See List of Atfwftts^^s otipAge ff4

73 Magazine • February, 1982 73

The uses for a tape recorder in the ham shack are legion: tap-
ing QSOs, CQs, code practice, traffic for relay, etc. The
recorder is probably of most use to the SSTV enthusiast in
editing programs and recording QSOs— though recorders
for SSTV work must be a cut above the average home-typ^
cassette. The Sony C-104, shown above, is ideal for these
purposes.

way to find out how your
own signals sound is by us-
ing your recorder to tape
them. You will need an aux-
iliary receiver for the pur-
pose, one whose antenna
can be disconnected or
which has an attenuator to
eliminate front-end over-
load by your own signal.
You can record your actual
on-the-air transmissions and
QSOs, of course, but if you
do any extensive "hello. . .
testing" for the specific pur-
pose of making a tape
check, be sure to use a dum-
my load rather than radiat-
ing a signal.

4) Code practice. You
easily can make custom
code-practice tapes using
your key, keyer, audio oscil-
lator, and/or keying moni-
tor in your transceiver or
transmitter to feed the re-

corder's input. If you have
an open-reel machine, you
can in most cases vary the
recorder's speed in a 2:1
ratio, that is from 1-7/8 to
3-3/4 ips, or from 3-3/4 to 7
ips- This capability allows
code tapes recorded for the
level of instruction desired
(audio pitch will change,
naturally). The recorder
also can be used to tape on-
the-air code practice ses*
sions regularly broadcast
by WlAW, the ARRL sta-
tion at Newington, Connect-
icut for later playback and
practice>

5) Traffic handling. Using
a recorder as a running
backup in traffic handling is
a good idea practiced by
many experienced brass*
pounders. If you handle a
great deal of traffic, you
know that a telephone call

or other unwanted interrup-
tion can make you miss part
of a message or cause you
to hold up your net while
you get d ''fill." Using the
recorder, you can effective-
ly tape your own fills.

6) Taping CQs and other
transmissions. There is
nothing wrong with prere-
cording phone CQs, if the
practice isn't overdone and
technical quality is main-
tained. For the most part,
tape-recorded CQs are not
necessary, and those using
them often sound a bit silly.
However, for contesting
and some DX work, there
ate time-saving possibilities.
A related application lies in
making extended antenna
adjustments and TVI check-
ing. Since radiating an un-
modulated carrier is illegal
(except for short periods),
you may want to prerecord
a signal which can be
played through your trans-
mitter again and again. For
both these applications,
special continuous-loop
tapes are available; these
come in various lengths to
fit the desired transmission
message length. Again, the
watchword is modera-
tion—don't overdo a good
thing!

7) SSTV recording and
play back. The tape record-
er is a "must" for the
SSTVer, who finds a wide
range of specialized ap-
plications. These include
generation of gray scale,
test pattern, and other
reference signals; im-
mediate playback of the
other fellow's over-the-air
picture; and building a li-
brary of interesting pro-
grams from two-way con-
tacts. By far the most im-
portant use is in prerecord-
ing one's own "programs'"
for later broadcast, This
allows for careful prepara-
tion and capturing of art-
work and photography,
tape editing, and review.
The judicious use of a sinrv
pie tape machine has en-
abled many SSTVers to pro-
duce very smooth, interest-

ing and professional-quality

program material that's a
pleasure to watch,

8) Computer interface.
Small cassette recorders
provide the basic means of
programming home-type
microcomputers If you're
equipped with a microcom-
puter with an electronic
RTTY and/or CW interface,
the recorder provides the
means to set up the com-
puter for RTTY or Morse
transmission and reception,
and it also serves other an-
cillary functions. For exam-
ple, in the author's Macro-
tronics M^650/PET 2001
system, the recorder is used
to prerecord messages for
later transmission and to
record received messages.
So-called "brag tapes" and
artwork can be stored on
the tapes and exchanged
with others.

Besides these specific
uses, it's often handy to use
a tape recorder to verbally
document equipment set-
tings and alterations, meter
readings, and test results.
The work being done is de-
scribed as you're doing it
with the recorder doing the
"writing." Subsequent play-
back of the tape, and writ-
ten transcription to a
notebook or log if required,
may be helpful in inter-
preting and analyzing re-
sults and in learning from
past mistakes.

Technical considerations.
Authentic high-fidelity
sound reproduction isn't a
necessity in a ham shack
recorder, though a few re-
quirements do exist. The
recorder should be of rea-
sonably good quality [not a
child's toy, to be sure),
feature low distortion, have
an auxiliary input for direct
connection to the receiver's
speaker, and include a
recording level meter and
tape counter. A "pause" or
"edit" control is also a
desirable feature. Re-
quirements are tighter if the
unit is going to be used to
record SSTV signals or in*
terface with a microcom-

74 73 Magazine • February. 1962

6EMQUAD FfBREGLASS

ANTENNA FOR 10, IS, and 20 METERS

TwoBements $215.00
Extra Elements 5154.00

Price is

F.O.B. Transcona

INCLUDES U.S.
Customs Duty

KIT COMPLETE

WITH

• SPIDER

• ARMS

• WiRE

• BALUNKIT

• BOOM WHERE
NEEDED

2 element 2-me}:er Quad N/C on
request, introductory offer with pur*
chase of quad.

WINNER OF MANrrOBA DESIGN

iNsrrruTE award

OF EXCELLENCE

Bui; two efements now — a third
and fourth may be added later with
little effort

Get a maximum structural strength
with low weight, using our 'Tride-
t\c" arms.

GEM QUAD PRODUCTS

Traitscondi Manitoba, Canada R2C2ZS
Box 53 Telephone (204) B46 3333

TRS-80* I, III OWNERS:

Send and receive CW with MFJ's new CW transceive pro-
gram and interface. Just plug-in interface, load program and
operate. Gives you Tri-Split screen, 3295 cliaracter buffer,
10 memories, "Fist Fixer." aii you need to

send and receive CW.

TRSaO Modalt I iitd 111 CW Transceive pr(»'
gram and interface lets you send and receFve CW.
No modilications to rtg or computer,

Tri*Split screen lor receive, transmit, message
index. On screen transmit/receive "LEOs", trans-
mit speed indicator. "FiSt Fixer."

TRANSMIT: 3295 cliaracter (or more) buffer.
Preload buffer while feces vmg Transmit wfien
ready Ten 199 character memories. Repeat/link
memories. Erase chatacter, buffer screen. 12-55
WPM, Store 2200 cbamcters for gfoup practrce.

BECEIV£: Adjustable ^T\s\ Fmt" helps to copy
poorly sent CW, Self sdiustmg to tOO WPM, Re
turns lo receive when Iransmit buffer is empty.
Store Lip to 5 screens of received CW.

HARDWARE INTERFACE: Pfugs between rig
and compjter, Moise limiter, 4 pole active band-
pass filter, post detection filter, tracking compa-
ralor. Keys tube or solid state rigs. Tunmg. trans
mil. ON LEOs. 6?(1V4?t3 inct»es. Aluminum cabinet

'TBSftOisa
reg^iered trade
marii at Tandy
CorpnTaiaiwi

HF Shielded, 9-18 VDC or 110 VAC mXh opltonal
MFJ 1312 AC adapter, S9 95.

Requires TR$ BO Model i nr III with at least
16K. Program supplied on cassette tape.

Onler from MFJ — no obligation. If not delighted,
return wUhm 30 days for retund (less shipping)
One year unconditional hardware guarantee.

Order today. Call loll free 800 647 1800 Charge
VISA, MC CH man check, money order Im $99 9S
pJus S4.D0 shipping and handing. Order MFJ-1210
for THSeO Model t Of hAFJ t212 for Model IIL

Enjoy CW. See deafer or call MFj today.

CALL TOLL FREE . . . 600 647-1600

Call 601 323 5869 for technical intormation, or-
der/repaif status. Also cail 601 323-5869 outside
ccntinental USA and in IMisslssippi, 1^47

HAB I ENTERPRISES,

iWirW INCORPORATED

Box 494. Mississippi State, MS 39762

for your TRS-80

Cede Cl(a§§

LEARN

fVlORSE CODE

Code Class is a machine language progrsm
designed to teach the beginning Ham to copy
and send Morse code. It is very simple to use
and exgeptionally effective. With Code Class
you will be ready for your FCC license exam
in no time* Each o1 the lessons contains onty
4 characters and may be repeated as often as
you wish. Lessons combine doth easy and
hard characters so you learn the whole
alphabet. Also, for a greater challenge, the
cfiaracters learned in previous lessons may be
included in the currenl lesson. Of course, the
speed may be changed at any time without
interrupting the lesson.

PRACTICE

FOR LICENSE UPGRADE

The code practice portion of Code Class is
designed to help you increase your speed and
accuracy as simply as possible. You will be
able to practice copying random words, ran-
dom characters or random callsigns. After
each page of text the program stops to let
you check your accuracy. You may then try
the same page again or a new page. The
sp^ed is always displayed and is adjustable at
any time, even in the middle of a page^ And
Changing the speed does not mteirupt tJie
character flow.

RECEIVE

HAJSIDSENT CODE

Code Class helps you learn to send clean,
correct Morse Code. When coupled with a
Macrotronics Ham interface listed below,
Code Class will copy your handsent code.
Warning, this might hurt your ego, but it will
quickly improve your fist. Code Class even
displays your sending speed.
Requires a TRS-80 Model I f16K, level II
BASICS or Model III (16K, level IN BASICJ. To
receive handsent code attach a Morse key
and any Macrotronics Ham interface IM80.
Me3, CM80, CM83. TM80. TM83 or Ter
mi nail K Add any audio amplifier for super
sound effects. Disk S39, Cassette $!^.
Specify (VIodei I or III,

TO ORDER TOLL FREE

1 -800 344-7493

In CA & for service (209J 634-8888/667 -2888

* TRS-aO a B fiseognljted TrjKtemsrlc o* Tawtv Coifi>&f3lion

/VUtCROniONICS. inc. «

\\25N Gokfw Slit« Blvd.
Turiodk, Califcwnia 9S380

t^44

*^Ste Ltst at Attvefttsers on page T ?4

73 Magazine • February, 1982 75

puter; in these cases, a top-
qua! ity recorder having low
wow and flutter should be
selected Other desirable,
though not absolutely es-
sential, features include a
monitoring and/or auxiliary
speaker jack, public ad-
dress (PA) mode, automatic
shutoff or track reverse,
and fast forward and re-
verse capability A mono-
phonic unit is fine; there is
little advantage in using a
stereo unit.

Several tape formats are
suitable: eight-tracic, reel-
to-reeL and cassette. The
eight-track recorder, oper-
ating at 3-3/4 ips, uses
1/4-inch tape in a track con-
figuration that allows eight
mono channels or four ster-
eo channels to be recorded
Since the cartridge is ac-
tually an endless tape loop,
it will run continuously if
left to play out Very short
length cartridges are avail-
able, making this format ex-
cellent for phone CQs and
even short SSTV "takes."
The eight'track format does
have its drawbacks, howev-
er, in terms of less-than-
optimum audio quality, a
tendency for tapes to be-
come jammed internally,
and the objectionable
"click" and momentary loss
of audio when tracks are
switched.

The open-reel recorder is
hard to beat for quality. Us
distortion figures and fre-
quency response are best
among the three formats.
Various combinations of
reel size, tape length,
speed, and available acces-
sories add up to maximum
versatility and flexibility.
Recorder mechanical de-
sign is relatively straightfor*
ward (when compared with
eight-track and cassette
models), and maintenance
is less difficult and costly to
perform. However, the
open-reel recorder — at
least a good one — is ex pen-
sive, and tapes are not as
convenient to use as in the
other two formats, manual
tape threading being re-
quired on most models

Tape recorders fmd many useful applkattons in the harr} ^hack. A growing use h connec-
tion with digital microcomputers, where they are used for loading and recording of cassette
programs and data. Radiotetetype (RTTY) and Morse code interfaces are available from
several sources for popular home computers such as the Apple, PET, and TRS-80, shown
here in addition to the basic program-hading function, the recorder can be used to digital-
ty record on-the-air transmissions and to prerecord outgoing messages (including ''brag
tapes''} fof later broadcast (Photo courtesy of Radio Shack]

The cassette machine is
the most popular for ham
shack use today, for rea-
sons of relatively low cost,
operating convenience, and
steadily increasing quality.
The cost of a small cassette
unit is certainly not pro-
hibitive, with usable ma-
chines available for as little
as $25 to $30. Even high-
quality monophonic por-
tables come in at less than
$100 The ever-increasing
popularity of cassette ma-
chines is due in large mea-
sure to the ease with which
tapes can be selected, load-
ed, recorded, and removed
from the recorder, features
that are very attractive for
station use. Tapes in prac-
tically any length can be
obtained for recording peri-
ods up to 120 minutes or
more, using the standard
cassette speed of 1-7/8 ips
The biggest disadvantages
are that cassette editing

isn't practical, the low tape
speed mitigates against top
quality recording, and ac-
curate cueing is difficult.
Most portable machines
have an audio response that
is entirely adequate for
ham-band and shortwave
signal reproduction, howev-
er.

An SSTVer, 1 opted for
the Superscope C-104, a
very high quality mono por-
table that includes such de-
sirable features as cueing
capability, pause control,
nicad operation, built-in
condenser mike, PA func-
tion, and variable tape
speed The front-panel con-
trols and meter make it es-
pecially convenient for
stacking above the station
speaker or receiver — you
don't have to look down on
the recorder to operate it
as one must do with most
small portables.

Standard front-loading
stereo decks offer excellent
potential though probably
represent an overkill in
quality. A stereo deck or
recorder obtained at a rea-
sonable price could likely
be put to good use in the
shack, though the second
channel would be wasted.
The micro-cassette record-
ers also offer good possibili-
ties. Many of these units are
quite small, can be operat-
ed vertically, and thus can
be sandwiched in between
equipment units on the op*
erating console.

In using a recorder in
your station, you may ex-
perience trouble with rf
pickup, making it unusable
when transmitting. The
problem can be acute in
solid-state units and comes
about because of audio rec-
tification of your signal by
the set's amplifier stages.

76 73 Magazine • February. 1982

Alaska Microwave Labs

4335 EAST FIFTH STREET ANCHORAGE

ALASKA 99504 (907* 338^340 DE?T 73

«^0p DVftOK W^

Mir 3I| ■ ^. *i #<»

GaA5 f^&

MQF MO -*».«

4«,&

' .A.I

CMKcniiccei^

■h ai rt - *■ ^*. >f

r * ^ f a.4 Hb .j;^P

^iw

i««*i

raodTt iSBuniRS

>^#v •jfrvF^ ^ - r«t^ -^'^ fait.

'Nit N

Till '14 ft* *J

flt4

*7^

1H^

3,7-^-Fj&*/

^*S(9??

^bb. ftit*^ u0*« "rti- sa i*^ *^ ^

4fi.co

VTO

1^ "R*Sc

^^uo

3« W^*^

NEW VIDEO TAHNG AIDS

VIDEO STABILIZER: Eliminates copyguard. Lets you
duplicate and play any pre-recorded tape. DISTRIBUTION
AMPLIFIER/SWITCHER: Lets you tape 4 copies at
one time and select from 4 video and audio sources.

OPEN AT «PM EST CLOSED OPM PST
_ „ 9n Of H 5 A II i t^mitt* Cic paid

IF VOUOONOT SE£ <^4tJ6

WHAT VOU WANT ASH

WOf 0 STABfUZER
MFJt4QQ

¥i0EQ STABILIZER, WFJ 1400. Copyguarded
tapes cause picture roll and |itter tttat prevents
viewing and duplicatmg prerecorded tapes. Tne
MFJ Video Stabilizer removes copyguard so you
can play copyguarded tapes on any TV set and
duplicate any prerecorded tapes. Simply adjust
Lock Control for stable picture, 4x2x6 inches.

VIPEOAIIMO aSTBIBUTlON AMPURERySWTTCH-
ER, MFJ'1410. Lets you tape 4 copies at one
lime that are as good as the original. Amplifiers
supply video and atidio power tMiost tiiat eriminates
generatton loss and signal degra^lation. Buit-in
wftfeo-atidio switcher lets you select from four
video- audio sources (VCR s, games, etc.) and
distnbule lo 4 outputs (VCR's, monitors, etc) with-
out touching a single cabie. 6x2x6 inches.

Both kinltf have standard RCA jacks, eggshell
white cat>ir»et with simulated walnut grain sides.

DtSTRiBUTION AMPUFfER/
SWtTCHBR, MFJ-t4iO

1 to VAC or 1? VDC for ol^ftab^e use.

Premium videfl cuv cables with BCA pfugs
Gives distortionless video signal transfer, S feet.
$24.95 pef pair.

Order from MFJ ind trv ft - no obligalion. if
not delighted, return it within 30 days for refund
(less shipping). One year unconditional guarantee,

Mer tpday. Call toll free BOO 647 1 800. Charge
VfSA, MC or marl check, money order f&r amount
indicated plus $4.00 each snipping and handiing.

[hjpicatj«rt o( copyrighied malerial is illegal.

CALL TOLL FREE . . . 800-647-1 800

Call 601 323 5869 in Miss., oulside continental
USA OB for technical info, order/repatr status. ^47

ENTERPRISES,

INCORPORATED

MFJ

921 louisville Road, Starkvflla, MS 39759

^Ae <^meet (^oun^ina (^^epeater

MARK

SCR

A Stradivarius is more ilian a body, neck, and strings. The name alone says il is an instrument of out-
standing quality and beautiful sound.

In repeaters the name for optimum performance and clean, natural sound is Mark 3CR. And Mark 3CR
also means:

• Receiver sensitivity <0.25 uV, • Spurious rejection > 65 dS.

• Schmitt trigger squelch to capture fading signals • Autopatch and reverse autopatch

• 13 Morse messages • 15 Function controlled outputs

• Die cast aluminum receiver and transmitter enclosures

For the Finest in

Repeaters • Controllers • Power Amplifiers • Link Transceivers

MICRO CONTROL SPECIALTIES

^^ 49

23 Elm Park, Groveland, MA 01834 (617) 372-3442

^Se^ Uslof A^vwnt^^r^ qo psge n4

73 Magazine • February, 1982 77

ERC SL-55 audio filter is said to improve SSB and CW recep-
tion under severe conditions. The unit contains three
separate filters: independent and continuously-adiustabie
bandpass f liters as welt as a fixed tow-pass filter that can be
cascaded with the others. The unit generates 1 Watt of au-
dio and has an input/output in}pedance of 8 Ohms. (Photo
courtesy of Electronic Research Corporation of Virgina)

Simple RF [-preventive mea-
sures, such as installing an
rf choke and bypass capaci-
tor in the recorder's mike
and/or auxiliary input leads
and bypassing tine audio
output leads and ac line,
will often do the trick,
unless you have a very poor
station ground or are using
a voltage-fed antenna that
produces an inordinate
amount of stray rf in the
shack.

Various patch cords, con-
nectors, switches, and
jumpers may be required to
conveniently use the re-
corder with your equip-
ment; these only can be
determined after deciding
which functions the record-
er is to filL Using shielded
cable for all audio connec-
tions should go a long way
in reducing rf feedback,
noise, and hum pickup.

Audio Filters

The congestion on the
amateur bands has placed a
premium on receiver/trans-
ceiver selectivity. Simple
fixed-bandwidth i-f crystal
filters were good enough
for the 40s and SOs, but not
good enough to adequately
handle present-day QRM
conditions. Densely-packed
and overlapping SSB sta-
tions, closely-spaced CW

signals, and RTTY reception
through potentially obliter-
ating heterodynes demand
complex i-f filters or other
means of achieving a high
level of receiver selectivity.

Many upper-end receiv-
ers of 50s and 60s vintage
contained special i*f cir-

cuitry using double-conver-
sion techniques to allow
the operator to peak the de-
sired signal or null out an
offending one. At the time,
the best way to improve se-
lectivity on inexpensive re-
ceivers was to add an out-
board i-f -stage ''Q-multipli-
er/' which enabled the op-
erator to either peak a de-
sired signal or null out an
offending one by manipu-
lating one of several panel
controls. The Q-multiptier
(the best-known being
Heath's QF-1) was capable
of doing a good job, but
some practice was required
in using it It went out of
favor as the once-standard
455 kHz i-f frequency was
largely abandoned for high-
er and lower i-f frequencies
in double-conversion con-
figurations. The transition
from tube to solid-state de-
signs also had a lot to do
with the Q-mu!tipUer's de-
mise.

The basic means of at-
taining the desired amount

of receiver selectivity today
is by means of an i-f stage
crystal or mechanical filter,
Most high-quality transceiv-
ers use a filter with a steep
shape factor to reduce out-
of-passband signals and
noise; the same fitter is
usually used on transmit. If
your receiver or transceiver
has provisions for optional
i-f filters for reduced-band-
width SSB and CW recep-
tion, it's a wise investment
to obtain them— especially
the CW filter. Some manu-
facturers^ such as Ken-
wood, also offer provision
for adding a second (dual)
SSB filter assembly to fur-
ther sharpen the response
curve and improve the i-f
stage's signal-to-noise (S/N)
ratio Addition of the sec-
ond filter also has a benefi-
cial effect on transmit,
allowing a greater degree of
speech compression to be
used without a significant
increase in sideband splat-
ter and resultant band-
width.

While most i-f filter ar-
rangements don't offer true
single-signal reception,

those receivers and trans-
ceivers that have provision
for shifting the center fre-
quency of the i-f crystal
filter (variously known as
i-f-shift or passband tuning,
depending on the manufac-
turer) offer additional possi-
bilities for minimizing QRM
and further improving over-
all S/N ratio.

Even in those sets having
adequate i-f filtering, the

addition of an audio filter
can enhance performance.
The audio filter acts in two
ways: 1 ) It cuts down on the
wideband noise generated
by the set's i-f chain,
preventing amplification by
the sef s audio stages, and
2) it further narrows the
receiver's overall response
curve, often allowing true
single-signal reception.
Both characteristics signifi-
cantly aid reception when
the QRM level is up and
when working under weak-
signal conditions.

Passive audio filters, A
fixed-tuned, passive (norh
amplifying) audio fitter can
do a great deal to improve
the selectivity of a receiver,
especially one without an
i-f filter; in some inexpen-
sive sets, an audio-stage
filter is the pnmary selectiv-
ity-determining device.
Many hams found that war
surplus radio range filters
inserted in their radios"
headphones lead did a
good job in separating
closely-spaced CW signals,
though the filter frequency
of most of these units was a
bit high-pitched to suit
many and receiver tuning
and stability became criti-
cal when using very narrow
bandpass filters.

More sophisticated de-
signs have been developed
over the years, using large
fixed-value inductors to
achieve the desired degree
of selectivity at audio fre-
quencies. The radio hand-
books are full of good pas-
sive filter designs, especial-
ly for use on CW. A particu-
larly good one is the six-
element L/C CW bandpass
filter designed by Ed Weth-
erhold W3NQN. It appears
on page 8-27 of the 1980
ARRL Radio Amateur's
Handbook. Other W3NQN
designs appear in the De-
cember, 1980, QST Anoth-
er practical filter approach
is that of Del Crowe! I K6R I L
that appeared in the March,
1968, CQ Magazine in his ar-
ticle, "Adding CW Selectivi-
ty for Transceivers,"

Passive filters are brute-
force devices, however;
they are lossy — very notice-
able if one wants to drive a
loudspeaker. Though easy
to build, the passive de-
vices rely on large, cumber-
some and often hard-to-find
toroidal inductors, Also,
there is no flexibility in set-
ting the center frequency
and bandpass curve or
changing these characteris-
tics during operation. A far
more satisfactory approach
lies in the use of the active
audio filter.

78 73 Magazine • FebriraryJ982

electronic mail
aerospace
press
satellite

training aids
embassy/diplomatic

maritime

government

emergency/disaster

meteorological
oceanographic
handicapped
civil defenae

CONSIDER THE

You know of its reputation in Amateur
Radio. But did you know of its world-
wide uses in commercial/industrial
communications networks? ATR-68Q0's
are communicating over land-lines, via
satellite, and on HF/VHF radio links all
over the world. They're teaching
Morse Code on military bases around
the country and operating as TELEX &
TWX terminals. We offer engineering
expertise for your particular require-
ment be it Data Encryption, Computer-
ized Training or any special interest.
ATR-6800 with 9" video monitor and
one plug-in Applications Module . . .
$2495. Companion MX-80 printer . . .
$699. Contact the "REAL-WORLD"
at MICROLOG CORP. 4 Professional
Drive. Suite 1 19, Gaithersburg, Md.
20760. TEL: (301) 948-5307. TELEX:
908778. You'll be pleasantly surprised.

MICROLOG

INNOVATORS IN DIGITAL COMMUNICATION

t^See if St of Advert tsers on page ? M

73 Magazine • February, t982 79

Active audio filters. The
active, or tuned, amplifying
audio filter uses RC net-
works in conjunction with
solid-state amplifiers to
synthesize the inductor
characteristics. The simu-
lated inductance is resonat-
ed with a capacitor to pro-
duce a tuned'filter effect.
What makes this kind of
filter so popular with hams
is that the filter can be con-
structed with variable Q
and variable center and
cutoff frequencies; this
allows convenient front-
panel control of the filter's
operating characteristics
that the operator can
precisely tailor to suit his
mode of operation, per-
sonal preferences, and
band conditions.

The current spate of
solid-state active filter
designs are descendants of
the classic National Radio
"5electH>|ect" audio filter
that was immensely popu-
tar about 30 years ago. This
tube-type accessory was a
handy, quick-and-dirty sup-
plement to a receiver hav-
ing little real setectivity.
Present-day active filters of-
fer a number of spec J at J zed
features that make them of
great Interest to both CW
and SSB operators.

An active audio filter can
be built from one of the
many designs regularly fea-
tured in the ham maga-
zines; several are In the
Handbook, At least a dozen
firms sell these very cost-
effective QRM-suppressors
that allow even a modest
receiver or transceiver to
come to life in the selectivi-
ty department, particularly
on CW. Manufacturers in-
clude Autek Research, Kan-
tronics, M&M Electronics,
Datong, Electronic Re-
search Corp of America,
Palomar Engineers, MF|
Enterprises, and several
others.

Typical handbook and
commercial designs enable
operation on either CW or
SSB, though a few less-

expensive filters are for
CW-only or SSB-only use.
The majority are self-con-
tained and include their
own power supply or draw
power from the receiver or
transceiver's accessory
jack. Most are connected to
the set's audio output jack
and contain a small internal
audio power amp to direct-
ly drive a speaker or head-
phones. The filters enable
the operator to adjust selec-
tivity from a few Hz, for
razor-sharp CW perfor-
mance, up to a completely
flat response. Many have
separate high-pass and low-
pass operating modes, es-
pecially useful on SSB; oth-
ers have a deep notch fea-
ture that is used to null out
an interfering signal or
heterodyne without degrad-
ing the desired signal A few
sophisticated models allow
dual (simultaneous) notch-
ing and filtering; at least
one model contains a built*
in noise limiter.

Using the active filter on
SSB is a gratifying ex-
perience, especially if in

conjunction with a modest
set — though top~of-the-line
models will benefit as well.
By proper control-knob ma-
nipulation, if s possible to
dramatically improve sig-
nal readability under condi-
tions of QRM, static, splat-
ter, and the like— reducing
operator fatigue and mak-
ing listening a great deal
more pleasant. SWLs, IO-
meter AMers, and CB oper-
ators should be interested
in the capabilities of the ac-
tive audio filter, too. Selec-
tivity on the crowded AM
shortwave and standard
broadcast bands is consid-
erably improved, and sta-
tions just a few kHz apart
can be separated with little
cross-channel interference.

The real thrill comes
when using one of these
filters on CW. Used in con-
junction with a set's existing
CW i-f filter, results can be
truly impressive. With the
active filter, the desired
signal can be peaked with

Palomar Engineers' CW filter connects between the receiver
and a set of stereo headphones. There are actually two
filters, a narrowband one with an 80-Hz bandwidth

(centered at 800 Hz) and a wideband one that cuts out hum
and high frequency interference but passes most of the
receiver audio signal. The narrowband signal goes to one
ear, the wideband to the other, giving simulated-stereo
reception. The effect is to offer a signal ''mrx" that is an /n>
provement over either filter alone: The off-frequency
signals appear in one headphone, the desired signal in both.
The operator's mind concentrates on the desired signal and
rejects the interference. Long operating periods are said to
be less fatiguing using such an arrangement (Photo
courtesy of Palomar Engineers)

an effective bandwidth
measured in tens of cycles,
even in the presence of
close-by strong signals that
have managed to bull their
way through the radio's i-f
strip. Even with a sharp i-f
CW filter installed, it's
possible to actually tune
through the set's i-f pass-
band with the audio filter
and discover several in-
dividual CW signals that
can be brought up to solid-
copy levels that were un-
readable or scarcely detect-
able without the filter. Of

course, there is a limit to the

degree of selectivity one
can crank in; with too much
selectivity, filter ''ringing"
becomes objectionable. Al-
so, using the notch feature,
very pronounced unwanted
signal rejection [sometimes
70 dS or more) can be at-
tained by proper control
manipulation.

Space-age f Uteri ng. A
couple of takeoff s on ac*
tive filtering techniques
have surfaced in recent
years. One is the concept of
simulated-stereo reception.

SO T3 Magazine • FebriiaryJ982

Same peopU u/tont t^ ^cH€4t,

Introducing the New Loiv Cosi Spectrum
SCR-77 Repeaters— 2M, 220 & 440 MHz!

SPECTRUM COMMUNICATIONS

SES11 FM REPEATER

rvioaE

la.avac

^^U t&ANSMlT

• •^tii\.umm-

-Be^iLrtai^cTK'

AC t,tMB ' mil AC |3Cl^WEtl

LQCAC IV1ICI

- ^ -s

15 or 30 Wt xmtrs.

Includes: •Q.aS^V Rcvr. d Pole IF Filter

• Crystals— high stability .0005%

• Local Mic

• Your Cat! programmed into IDer

• Provision for Auto-Switchover to Btry, Pwr.

• Builtnn AC Supply; basic Panel Controls, Spkr,
LED Indicators

If you're looking for a new Repeater, but you real-
ly don't need (or can't afford) all the features and
options on our world famous, 'super deluxe'
SCR1000/4000, then our new economy line of
SCR77 Repeaters is ideal for youf

These new Repeaters maintain the quality of design, com-
ponents and construction which made Spectrum gear
famous. However, ail of the "bells & whistles" which you may
not need or want have been eliminated— af a large cost sav-
ings to yoal The SCR77 is a real "workhorse" basic machine
designed for those who want excellent, super reliable perfor-
mance year after year— but no fnlfsf ('PL' 12 Pole IF Filter,
Ffont End Preselector, and a 30Wt. Transmitter are the only
"built-in" options available; but Autopatch, Remote Con-
trol, and other equipment can be connected via the rear
panel jack)

"Y^ ^ eomfdete (me

caMe , etc,, C^ aJUa^ ^u^atiaHe*

^! ■T.«--\: ^

Of course, if you do want a fuij reaiured/super defuxe
repeater, with higher power and a full list of available 'built-in'
options, then you want our SCR1000 or 4000 *'Dream
Machine", These units will continue to be available for those
who want The Ultimate in Repeaters'.
SCR77 Pricing (15Wt,): 2M qx 220 MHz, $995.00 Amateur Net.
440MHz, $1150.00. For no 'pfug-in' ID board (Export), deduct
$40.00, Oat\ or write today for a data sheet, or to place your
order! Sold Factory Direct or through Export Sales Reps only.

10M FM RX/TX Boards, Repeaters & Remote Bases NOW IN
PRODUCTION! Call or Write for Full Info,

*^6e

SPECTRUM COIUimUMCA TKONS

11055 W. Germantown Pk, S2« Norristown, PA 19401 •(215) 631-1 710|

An ^'outboard'' active audio filter can yield surprising per-
formance benefits in conjunction with even the most ex-
pensive receiving equipment Assuming such a filter is used
witti a receiver or transceiver having reasonably good i-f
selectivity wrth good "skirts/" weak and QRM-plagued SSB
signals can be made to ''jump out of the noise'' in many
cases. And in the sharpest modes, several CW signals may
be copied within the set's passbandand tuned in separately.
Autek filter shown here is based on a design pioneered by
the firm in 1972, (Photo courtesy of Autek Research)

described by Max Blumer
WA1MKP in his October,
1974, Ham Radio article,
"Enhancing CW Reception
Through a Simulated Stereo
Technique." In this ap-
proach, an active filter is
used. Unprocessed receiver
audio is fed to one ear, and
filtered (processed) audio is
fed to the other ear. This
technique allows v^u to
read slightly off-frequency
CW stations white simulta-
neously hearing the desired
signal, in the clear, in the
other ear. The brain does
the ultimate filtering — it
"hears" all the signals, but
the processed signal stands
out so f idly, with the others
mentally rejected. The bot-
tom line is that the filter
allows greatly improved
reception of the desired
signal, but also allows you
to hear off-frequency re-
plies to your CQs; it's also
easier to scan the band us-
ing the simulated-stereo
technique. A stereo head-
phone is required for this
type of filter, which is of-
fered commercially by both
Palomar Engineers and
MFJ.

Especially interesting is
the automatic-tracking au-
dio filter offered by Da-
tong. In addition to some
impressive narrowband tun*

82 73 Magazine • February, 1982

ing capabilities, the FL-1
frequency-agile audio filter
features fast automatic sup-
pression of interfering het-
erodynes in the range of 280
to 3000 Hz by means of its
sea rch-lock-and- track
notch fitter. The tracking
notch can be left in the cir-
cuit with no audible effect
until a whistle appears, the
circuit then goes after it
and will suppress it within 1
second.

How does it work? Two
phase-sensitive detectors
control signals used for
automatic tuning. One pro-
duces a voltage propor-
tional to the degree of
mi stun ing, and the other
produces a logic level in-
dicating the presence of a
signal within the filter pass-
band In the absence of
such a signal, the integrator
becomes a sweep genera-
tor. But when a signal is
detected, the sweep stops,
the unit's lock lamp il-
luminates, and the integra-
tor becomes part of an au-
tomatic frequency control
(afc) negative feedback
loop. The filter then re-
mains locked to the "caf>-
tured" signal and will track
it, if required, throughout
the filter's range of 280 to
3000 Hz. This capability al-
ows the routine use of an

extremely narrow (20 Hz)
notch which does not no-
ticeably affect received sig-
nals and which would be
nearly impossible to manu-
ally tune and maintain in
tune. Of interest to CW ops.
an attenuated afc voltage is
also used in the manual tun-
ing mode to allow the filter
to automatically track drift-
ing CW signals over a
100-Hz range!

Whether you opt for a
simple or complex filter,
youH likely be glad you
made the investment. Dol-
lar-for-dollar, an audio filter
is one of the best accessory
aids you can buy for your
receiver or transceiver,

Wrap4Jp

In this article, we have
discussed a wide range of
basic, yet important,
phone- jack accessories:
headphones, speakers, re-

corders, and filters, with a
view to obtaining maximum
usefulness from dollars
spent on station equipment
For most hams, this group
of reception accessories
probably represents the
most important initial ac-
cessory investment- For this
reason, and for space limi-
tations, we've not discussed
exotica which might other-
wise fit the article's "phone-
jack'' scope, such as SSTV
viewers, RTTY/Morse de-
coders, monitorscopes,
phone patches, and the like.
We'll reserve discussion on
these "second-leveT' ac-
cessories until a later time.
In the final analysis, you
must decide which, if any,
accessories to build or buy.
Hopefully, the criteria, sug-
gestions, and observations
provided in this article will
help make your decisions
both logical and wise.l

Further Reading

The following reference sources provide addttionai infor-
mation, theory, and construction details. Several contain fur^
ther references to other information sources you may wish to
consult:

Jim Ashe. *'How to Use Hi-Fi Headphones," Poputar Elec-
tronics, July, 1972.

Ronald M, Benrey, ''Adapting Stereo Phones for Hams/' Efec-
trorrics illustrated, May, 1972.

Fred Blechman K6UGT, ''How to Use a Tape Recorder In Your
Shack," Electronics Illustrated, July, 1962.

Max Blumer WAIMKP, '^Enhancing CW Reception Through a
Simulated Stereo Teohnique,'* Harr\ Radio, October, 1974.

Len Buckwalter, "CB Scene" column in Popular Electronics,
May, 1974.

Richard Humphrey, "Accessories for Yoyr CB Rig/" Popular
Electronics, October, 1973.

Del Crowell K6RIU "Adding CW Selectivity for Transceivers/'
CO Magazine, March. 1968,

James R. Kates WB8TCC, ^'Put a Tape Recorder to Work in
Your Shack/' CQ Magazine, December, 1977,

The Radio Amateur's Handbook, Newington, Connecticut,
American Radio Relay League, 1980 edition.

Charles Schauers W6QLV/4, ^'Ham Clinio" column in CO
Magazine, May and June, 1961.

Karl T. Thurber, Jr. W8FX, "Ham Shack Accessories: What
You Really Need/' Ham Radio Honzons, December, 1979.

Karl T. Thurber, Jr. W8FX, "Ht^Tech Gear for Hams and
SWLs/' Popular Electronics, August, 1980.

William G. Welsh W6DDB. "Headsets and Ham Radio/" 73
Magazine, February, 1972.

Edward E Welherhold W3NQN, **Modern Design of a CW
Filter Using 88- and 44-mH Surplus Inductors/* QST,
December, 1980.

OSCAR ORBITS

OtCML • OfiBITAI iivoiHAnov r&x mwgjjt

d«CU ff QUITKL lirQiRATll?* FClfe ftWAXr

• Th© Amsat Software Exchange has recently been formed and is
now accepting orders. The first program being made available is the
orbital prediction program written by Df. Tom Clark W1IWJ, it is
available for most popular machine environments, with other ver-
sions being developed. Presently available are TRS-80 disk and cas-
sette versions. Apple/M diskette. Microsoft BASIC, and PUI-BO. This
progrann will accommodate the elliptical orbit tracking required for
the Phase III satellites. For complete information on versions
available as well as new additions and ordering information, send an
SASE to: AMSAT Software Exchange, Sox 338, Ashmore IL 61S12.

• The early months of amateur radio's newest satellite, UoSAT-
OSCAR 9, were full of developmental work. The Surrey, England-
based ground crew concentrated on generating and relaying to the
bird a computer program that will allow the craft to stabilize itself via
on-board torquing coils and a gravity gradient boom. Once this is ac-
complished, the experimental part of the mission will commence.

• AMSAT, the people who organize ham radio's space communica-
tions program, received a "royal boost" from JY1, Jordan's King
Hussein. While visiting the US In early November, the King ex-
pressed his support to AMSAT President Tom Clark W3IWL

• Although the AMSAT financial picture has been brightened by
several large donations, there is still a need for grass-roots support
by the entire ham population* You can find out more about AMSAT
by writing to: The Radio Amateur Satellite Corporation, PO Box 27,
Washington DC 20044,

Information for this column comes from the AMSAT Satel-
Me Report.

OWIT *

TUB.

■Op CBDSaiVC

OtSIT •

turns.

firift

WO* CSDiVlK

foni

mtSMSES HfSfl

torn

toaomt msf*

ifi»

VMSfSt

7f,l

177i

tUlifl

157, •

ltf41

it%i±ai

■t.2

17*1

§131 i$T

lf4^S

tf»i»

«t55£n

11.4

ISffi

ftllti^4

113.1

n^tt

§959t25

12.5

1021

mil St

149. 'J

199U

tli*it7

93,7

1B1&

§l»i4T

147.1

1949S

0109^39

114. »

1151

§§4li43

14 4.5

31113

«113iil

B£.i

18««

|«3«t39

142,1

3ti2«

HIT; 41

»7.2

isal

■I2l»]ft

139,3

2§U§

•

tiia^ii

IS. 4

letb

§§l§tl7

114.9

199V*

il2fi±4T

B9.S

1934

Itltr29

114*4

2«i«i

40I:II

f»,7

1927

I12S44I

155. •

Still

ril&sSl

fl,fi

194JZ

fttiiia

l&l.J

U9M

tli.9t72

93.1

19*7

§l§5iJI

15§.«

3ttt»

ii4I±41

fit. 4

l»72

■■55t34

141,2

IBM J

■ ■Htl5

6f.5

19IT

■■45L3f

145.T

3tI37

4lli:4T

n.7

3fll

1«

lt3St27

141.3

3fl&l

lil^fll

71. i

J»17

ttasiaj

141^7

UitS

It 14? 51

73,*

2t3l

ttlsll*

131.3

If 179

Ip24t22

74.2

2t47

1113 111

135,7

20193

iPzaTU

75.3

3iG3

illi:}!

1^7 * t

ii2ti

B^JJiXS

76,5

lilti

l91Jiai2l

154,5

10321

lll37E5e

n.$

2P93

§lltl2S

I52.i

3§2n

Df42^2e

78, B

21M

tltllll

U9.3

2»34«

0l4St»9

it,t

2121

§§5ffll8

147,1

I919i

H^ifSl

U.l

Sl3i

§141 iM

144,5

It 277

tt»?t2

92^

21S3

§ill[ll

14 3. §

lf2»l

fltlr33

■3.4

21 « I

§ff3§l§7

llf.5

2i]iS

ill5£l4

t4.i

21 ■!

2fll

§ittit4

137^1

oaCMt 1

fXW^ltm. tHrcMATIOK

rOR KARCR

oacuft t

OUITM. UrOMATIOII

warn luitai

OIUJT $

bMt

yiJE

BQ. csssBtva

ot«rr f

GATE

TIW

TO. CHOSffilSG

fiiwr)

fCiBQItSES WEST}

(GHt(

tDEORF.ES KCStI

2i319

Bi09?35

35.1

219a

§i§<iii

134.5

2tl31

HlKiBT

a£.»

2214

ll3!ilS

i54*a

»34T

Piie^ie

«a,x

1229

in^iH

151,1

ZMUi

»123ii9

as. 2

2244

1145119

15«.l

J*Jt5

»i2Ts4l

M.4

225t

§§55ii5

14£.l

ZflBt

•112:11

n,5

2274

i§4»ii2

141.«

i9$93

•3 36^42

«_7

22lt

t§MiS§

143.3

ini?

ii4ia3

ta,t

2314

#§}4|5S

141.1

U€l»

i 112; 33

49.2

21I«

•114 t 51

131.3

2t44t

fif7:t4

7f.4

1134

f§#4i47

m.t

M49>i

1.1

It U 1 35

TX.5

21^t

ill*it4

157.1

aM7f

Ills It*

r2,t

a3^«s

f 12«i ft

154.*

114 If

fl2iiJ7

73.1

21»i

•lt»iS«

152,1

iHii

fB2^iiir

75, ■

2395

§§5»j51

141. §

21514

li.

tl29t3i

7fia

24Iff

§949 i4»

141,1

2iaii2S

«S34tt»

TT.3

242S

1«

■Ii9t4f

U4.i

,m^<2

0«3»H»

7&.5

2441

§l29i«^

141. §

Ifi

B043il0

79. ff

2455

ill9<3e

119.5

». J _ s L.'

B047i41

B0,e

2471

§t»9jl&

lJ7»i

i9bBi

ll^^tXl

■1,9

24Bft

pii4t^i

151.4

a»va

tiMi4J

sia

Z5tl

Ill4i47

14 J. f

2fil3

*ieiit2

i4>3

25i«

»114t44

153^4

»«;(

«I»:4l

f^.«

7^11

•It4j4§

iit.i

If it*

tiif±ij

*£.S

254«

•»M]37

I4t»l

Ji«54

1114:44

■7.7

2HI

ff#44ll3

I45.t

i*i«a

1I1»j14

tt.t

257f

ft34fl§

141.1

Ut9t

tl23;i4

99.9

75»1

•t34i3C

t4t,t

2t9H

tlUilS

fl,l

2ft«

4iUi22

111.2

29119

tll2ti5

f2,l

3«2i

ff§§4at

llf^t

2IT34

§137*15

13, S

2«37

tU9f35

llT.l

2IT»

il4l : *%

94. i

2i%2

§119iJl

154^i

WHAT IS AN AUdfO RLTER -^

W^v buy a Dalong audio tiliar wtusfi

yc3u can get o{^>ef audo HtBri lor

naif the ptice'^

To answef this you Brsi n«d to

f gmcmtef fiatiha iie suciiohH^

C8n mi^an aili^^hin^ even down to 3

coup{€ of 74 1 s and a handfur o<

parts OnJy bv compafHig hke- mtifi

me can you make an iRfornred

decision This means comparing

features, performs ixie and qu rill tv I'

you send lor our free daia sheets

and compare our producls wi4h ihe

CGNtipelitKin vtHj will ^>e that reaiiy ifiere ts wirtuaiiy nooomjsetrttoti

iEt Oijr chdsen standard of peftormance

. What other aide Wer can
A tyiie ^140 heteiodyn

j^^l wMsHes snd notdi itieiTi
■'^^H out i4iiioffiJtteeiiy Wte our
B ^ ModeiFLt'' YetMbdeifLi
H am *5 also such a good CW filter
H V^ thai itiswidi^^yu^eKiby
|H ^^ pro(ess«onaMria(fi€ handlers,
^1 # What olher aiidio filler ha^
I^Jr passband edgtis sharper itran 5SB
i^iir ciysial f trters and yc\ which can be
tsm&a at wiU from 200 lo 35O0 Hz*^ To puii oft itits inclt ouf
Msde^ FL3 tees rip ie$§, Ifian 32 op amps plus ^ale-of-the-
art pM^te iividRh rfwdutatun technKiuas Two^-pcs^eeipta:
liters and a 2-$Kiie|»aii^ notch hhptfiKineboi ai
irviepeiideii%tijwabie add up toa koi Ftiore ItHerK}
Capabtirty 1^ ^O. FUTV CW ttian you wiiH find in arty oCt¥T
auOio tinner" that we^noAr of
To answer our question (Hen. an 'audio 'titer' ' can tw almost
anything On the oih-er hand, (he phra-Mt " Daiong Aydto
Filt^F" 15 ^ loi mote pf«ise IT aiartds Tof staie-of the-art
filTenrtg biaci^ed by exlra capabilitv o^lra Itiorough desigh
and exira rraality If you need conlirmaljon ask a user*

A0OmONAL PRODUCt$

Ju$i ^B. <iu^ fwQ diud)^ iiVi^v sefi new siin^^tii ^orwwmv siwor^ t/fitS
tfwntion oiralberpniduct^&demanctnneifsconsjcter^loilor
some riosons EachD'ier^aLtfVpieoomtmsioiDliedSurKwhcfi'

Model ASP: TTie -smart"

speech pfocncor

The automatic circuiifY ^ Model

ASP senses your voice tevel ann

reacts accordingly lo always

maintain the deqrwe of true r!

dipping selected fin decibels) by

Ihe panel pHJsh-buUons Novel

cif cuitry avoids ' ' han^- ups " by c^scr^inating against noise spikes and non'Speech infxits Mahe no

misrake Model ASP ccmnKts in the mcrophone tine yet ^ves ime r1 dffiing tor speech

enhanoerneni wiiti frurwrnyrn dtstmtofi

Modes D70." The go-en ywherw Ueir«c Codm Tutof

EiCf acung siity hours orfcMCte pfaca<« from alow c««i fine wottdati^

10 practice anywti«fe ^ stM your bmeoble and hte$ty%. VkMM DTQ's vsnatlm warn deiay between

tettgfs IS ilie key lo painlBSSPfpptass *i code receptton Sm-ipiyseTthe SPEED control to say t2

words per minute and feduce (f»e eifira "OELAV ai your ai3«ifty (mpro'w^es

$99.95

unib

'Lc4Mi|i^|i.j^

,^^.1 •^•^_ ^zz^

Ti n . I HV^^^^^

Mfftel PCF : Adi^ fill I ra^ve
cuverflge lr»m saKili i« ja MHi
to tny 3 m4lri §H modt rtf .
tlMJgned for hJgh pe^rformnnct.
Model PCi '«§turei LSt
lyrirheai&ehri for 1 MKj &ie».
^rimetrlc mlRitr f^r extrfe gooa
dyfiAfnic ran{i«, 4itH9n%tf ic sfHccTiori
<rf rf pr«#tector iiltem &Ann« c«t«
Si rie a4 f^L 1 ar>d ASF prict flH, r»

&»a C*

iiodel O70

Modal DC »4VUl Hl■^ dTn«mlC
r§n#« 3 mem cenirtfitr

Eip«cliilly luitabi? tor u»« with Model PCI

Id 4^(7 SpO kHl to 30 MHf cov^raoe to

2» ^ MHi rK^itfw. U^n ScJnoltky mtKFr PTH boarU

ittii Dv«rtpnv crvit«i DicMlatcr. Pricf 174 f3

MadBl VLF: Cmtal conl rolled i:&nvtTivr Adda H) ^Hi

ic- UO kJHii rec«i»iion to ».0 to 2t.5 MHt receiver

PfK»IJ4-»f

>«

Technicot
Products

Cofp

Box 62,
155 S.B«t«s St.,
BrrmlnghKnii MIchiQAn 40012
T9t«ptioni 313^44-5696

ALL DATONG PRODUCTS CARRY A 90 DAY WARRANTY
VISA ^ MASTERCH ARGE WELCOME

.^329

i^See Li^t of Adverfisers on page 1 14

73 Magazine • February, 1982 83

ANNOUNCING

A newr standard of comparison for

the all NEW

BROADBAND WITHOUT COMPROMISE

For years now, whenever hams got together and talked about the performance of
any triband antenna, they would invariably compare it to the famous Hy-Gain
TH6DXX. Now, there's a new standard of comparison— the NEW Hy-GainTH7DX.
This amazing new tribander. using a dual driven element system, maintains a
VSWR of less than 2:1 on all bands, including ALL of ten meters. Hy-Gain didn't
compromise on performance to achieve this efficiency either. The TH7DX utilizes
a combination of trapped and monoband parasitic elements for more efficient
broadband performance. This unique combination produces an average front*to-
back ratio of 22dB on 20 and 15 meters, and 17dB on 10 meters. The TH7DX,
with itsgreat broadband characteristics* is the ideal choree for "all mode"' operation.

HIGHEST TRIBAND PERFORMANCE, BUT
MANAGEABLE SIZE.

The broadband TH7DX has high performance specifications that meet or exceed

the monster antennas that seem to take up most of your real estate and part of

20 Mo1«r«

ISlMers

,'V

to Mttlon

-i-j_4_ja-^-

•I

iJl

t*« ■!*«.■ a. ■■■■«■ ■■■■■««

*•■

*!# ?!■ ttj ¥ij »« ni irt»

m KH

Write for our technical data report and oonnparative test results.

your neighbor's. However, with its short 20 ft. (6.1 m) turning radius and 31 ft.
(9.4 m) longest element, it's no more imposing than a THSDXX.lfs easy to assemble
and weighs only 75 lbs. (34 kg), The wind loading is 240 lbs, (109 kg) at 80 mph
(1 29 kph) with only a 9,4 sq. ft. (0.9 sq, m) wind surface area, so the TH7DX is one
of the safest and most manageable high performance tribanders you can buy. And.
you don't have to spend a fortune on special towers and rotators either

MECHANICALLY SUPERIOR

In a parasitic array such as the TH7DX< high efficiency traps are used rather than
parallel stubs. These Hi-Q traps are capable of handling the maximum legal power
with a 2:1 safety margin, and are superior to parallel stubbing for ease of assembly
and maintenance as well. In fact, quality materials are used throughout this antenna.
Includes 18-8 stainless steet hardware for all electrical— and most mechanical-
connections plustaper swaged 6063-T832 thick-wall aluminum tubing. The antenna
includes Hy-Gain*s BN-86 balun and exclusive heavy, die-cast aluminum, rugged
boom-tomast clamp, and heavy-gauge element-to-boom brackets.

CONVERT YOUR TH6DXX

Hy-Gain hasn't forgotten about the thousands of proud TH6DXX owners, A conver-
sion kit is available which offers all of the broadband advantages of the TH7DX
and includes a complete stainless steel hardware package.

Ifs easy to assemble, andwhencompleted. you have the
finesttriband antennaon the market, the TH7DX,

Limited time only

FREE OFFER

Buy thftXHZDX befora March 31 , 1982; send us the warranty
card and dated proof of purohase no later than April 15, and
we'll B0nd you a free Pro Com 30O boom mic headset—
an f6d.d& value.

THs is an ullrallght, slngle-aided. avJatiof>-style headset w4th
powerful electret mlcrophofve. The dual impedance micro^
phone haa a 100 to 8000 Hz frequency response specifically
tailored to the human voice. And, it equals or exceed-a the on-
the-ak performance of any desk mic. regardless of its size
or weight Leaves your hands compieteTy free for maximum
flexibility Once you Ve tried it, you may never clutter up your
operating area with a desk mic again.

hu-gam

COMMUNICATIONS. INC.

9600 AJc»nc:h Ave So . Mrnnespc^a. MN 55430 USA.
22. rue de la LoQion-d'H^K^nmjr. 93200 St OBns, Franci

NEW MFJ-312 VHF Converter lets you

HEAR POLICE/FIRE CALLS

and Weather Band on 2 meter rigs. Covers nearly all FCC
allocated police/fire VHFhi freq. (154-158 MHz). Direct freq.
readout on synthesized, VFO 144*148 MHz FM rigs.

Scanning rigs bmcomB

Now with weather band coverage! poiic^/fire scanner.

Oirmct frcq. readout on
mynthesis^d and ¥FO rigs.

H«ir eitcltfng poUce/fire ciUs, weatt^^r band,
maritime costal and more on yoof 2 meter nq]

Scanning rigs become fMJIiceifire scanner.

Ttut ingemoos MFJ VHF Ctrnverter turns your
syntfieSFied of VFQ M4 148 MHz FM rig into a
twt polbce/ttfe receive! (1M 158 MHz) with direct
frequeficy readout on your ng.

Receive weather plus more on 1 60-164 MHz.

Feedihru allows simultaneous scanning of bolU
2 meters and polree/fire band. No massed calls.

Enjoy all benefits of youf rig sucfi as squelchp
excellent sensitivity^ sefectivify; stability, limiling,
AM reteclion For tiandhelds. too

Two MOSFETS (tuned RF amp, mixer), bipolar
crystal osctllatof gtves o?(cellent peHarmanco.

Bypass/off switch allows transmitting, Won't
bum out li you transmit (up to 25 wattS/ witt\
converter on. Low insertion SWR.

■Oi" LED. 9-18 VDC, SO 239 Mtg M. 3*4x1 "-

MFJ 311. $49,95. Like MfJ 312 less WX band.

Order fmm MFJ and try it — no obNgation. If
not delighted, return it wittiin 30 days lof reiund
(less shipping). Qtie year uncondittpnai guarantee.

M«r today. Call toll ifee 800 647 1800. Ctiarge
VISA, MC w mail check, money ofder lor $59.95
for MFJ 312. $49.95 for MFJ-311 plus S4 00
each shipping/handimg.

infoy exciting police and f}re calls, order now

CALL TOLL FREE

800-647t800

Call 601-323-S8S9 for technical informalion, or
def/repair status Also call 6Q1 323 5869 outside
cominental USA and m Mississippi. t^*i

ME I ENTERPRISES,

Iwl m%M INCORPORATED

Box 494, Mississippi State, MS 39762 ^

ANYBODY CAN

SELL TVRO EQUIPMENT

But Only Our Dealers can

sell the right equipment
for the right price.

Dealer Single Lot
1395 FOB Hastings

/\Star Vie

t^ 86

Systems

H&R COMMUNICATIONS, INC.

Route 3, Box 1 03G - Pocahontas, Arkansas 72455

Introduces the

MODEL 12K
SYSTEM . . .

A complata •«t9llit9
r»coivtng system that you
can assembls yourself as a

week-end project*

Why spend $7,000 to
#10,000. Why pay someone
else to install H^ Do K
yourself in a week-end and

onIy $2,400.00

UPS
SHIPPABLE

>AJB Miscellaneous Cable
arid Connectors Needed
Everything Vou Need
No Special Tools. Needed
Complete Antenna Weight Only 125 Pounds

KIT CONTAINS

*12* Aniennii

*A2/EL Mount

•24 Channel Receiver

•120»LNA

■Teed Hom

See Your Local Star View Dealer or Call

800-643-0102 or 501-647-2291

DeaFer Inquiries Invited

^^ ^^m^^^ ^^ a^H ^^

12 Ft.

* Scaler Horn

F/D .375

• Rotor

Alyminufti 24

Section

• Rotor
LNA

Mounts

Offset Polar

« 41 DB Gain

mount

Nominal

COMPLHE SYSTEMS AVMUBLE

HASTINGS

ANTENNA

COMPANT,

INC.

847 W. 1ST ST.
HASTINGS, NEBR. 68901
402-463-3598 ^a

FOR THE SERIOUS DEALER ONLY

86 73 Magazine • February, 1982

Birth of a legend

National Microtech, Inc. introduces
Apollo « X9 Satellite Antenna $1995*

National Microtech, Inc. continues to sell
more home satellite antenna systems than anyone in
the world. Microtech's new Apolio, ^X9 is so far ad-
vanced over our competition — in features, perfor-
mance and cost — that we feel Apollo, „is destined to
become a legend in the satellite industry.

If you are interested in buying or selling Apollo

systems, give us a call today.

Remember, no one sells Apollo J>ut Microtech
dealers and distributors. This special introductory offer
is good for a limited time only.

^Suggested retail price, LNA and Receiver not includ-
ed, Optional Remote Satellite Finder $995-

National Microtech, Inc.

1 -800-647-61 44

In Mississippi 60V226-8432

t> 100

A Dish Antenna
Anyone Can Build

no hyperbole, just a parabola

Michael Brown WSDjY
6297 Brown Run Road
Middletown OH 4S042

Are you contemplating
the challenge of oper-
ating on the amateur micro-
wave bands? What about
getting in on the excitement
of receiving satellite TV sig-
nals? These and similiar
projects usually require a
dish-style antenna. You
could buy one or, better
yet, you can build one. This
article will tell you how.

I wanted to put a signal
on the 1296-MHz band. To
do the job right I needed a
dish antenna. I took the
plunge at a hamfest, buying

a surplus military job made
of spun aluminum, about 6
feet in diameter. It was one
of those good deals you
can't pass up,

Now my "good deal" sits
in the corner collecting
dust, waiting to be sold at
the next hamfest. I man-
aged to get a signal on 1296
using a dish two meters in
diameter that 1 built myself.
The design is one which
uses easily-obtained materi-
als and has a total cost of
less than $100, Best of all Jt
need not be a long, in-
volved project. In fact, you
can build a dish like mine in
a single weekend.

Photos by Tim Daniel HBRK

Photo A. The finished dish is light enough to be moved easi-
fy; the author stores his away each winter.

73 Magazine * February, 1962

Some Theory

Before we jump into the
details of construction, it
would be a good idea to
took at the basics of dish
design, The dish, resem-
bling an oversized child's
snow saucer, is a parab-
oloid. Its unique geomet-
ric properties cause it to
collect a beamwidth of
energy from a distant
source and reflect it to a
central point known as the
focal point, or focus. Sinni-
larly, a signal radiated to-
wards the dish from the
focus will be effectively ra-
diated by the antenna.

The important dimen-
sions of a paraboloid are
shown in Fig. 1. The reason
my ''good deal/' dish turned
out to be a piece Of junk
was that the relationship be-
tween the focal point and
the diameter was all wrong.

Known as the f/d ratio,
this relationship is very im-
portant when it comes time
to feed the dish. Experience
shows that dishes with f/d
ratios of 0.5 and greater
can be fed easily with a
horn-style array, (My com-
mercial dish's f/d ratio was
about 0.25 and was difficult
to feed.)

The diameter (d) is impor-
tant in determining how

much gain the antenna will
have. Obviously, a dish 6
feet in diameter will collect
more signal than a 3-foot
dish. Each time you double
the diameter, the gain in-
creases by a factor of four
(6 dB). The actual gain of a
dish depends on its efficien-
cy and the frequency it is
used on. Assuming a rea-
sonable efficiency of 50%,
a 2-meter dish should have
about 25 dB of gain over a
dipole source at 1296 MHz,
The 3-dB beamwidth will be
about 8 degrees. Fig. 2
shows these relationships.

Once you have chosen
the desired diameter, you'll
know where the focal point
should be to achieve an f/d
ratio of about 0.5. In the
case of a 2-meter dish, f will
be at one meter.

The exact curvature
needed to obtain a parabo-
loid with the desired focus
and diameter can be found
using the equation y^ = 4fx.
By calculating a number of
points for x and y, you'll
have an accurate plot of
the shape required. Let's try
an example for a dish with
the focus at one meter: The
X value corresponding to
the y point of 0.5 is found
by solving the equation
0.5^ = 4n)x. A little algebra
yields: x = 0.5V[4(1)].

10
9

T
6

-i

■

3
1

' \

ISf

«
7

FOCUS -1 METER /

4 » e T a • 10 /

y»=4fit

y=1,x = .25

y = .9, X = .2025,

y = .8, x = ,16,

ysj, x = .1225

y=.

6.>

t = ■

d>Z METERS

y =

.5,

x =

.0625

y =

^4.

x =

.04

.3,

X-

.0225

x =

.1.

)C-

,0025

fig. 1. Dish dimensions. Width (c) is found by solving:
f = d'/16c.

Punching the calculator
keys, we come up with the
answer x = 0.625 meters.
Fig. 1 also shows that the
total width of the dish, c, is
found with the equation
f = d^n6c.

That's all there is to de-
signing the reflective part
of the dish. Now let's look
at how to build it For
starters, you should be
prepared to work with
metric measurements of
length I found that the use
of meters and centimeters
helps to ensure accurate
results. For noncritical mea-
surements, we'll refer to
English units.

Once you have a set of x
and y values, it is time to
fabricate a surface that ac-
curately depicts them. Any
irregularities will impair the
antenna's gain. At 1296
MHz, deviations of up to
1.5 cm are tolerable. As the
frequeocy increases, this
tolerance decreases. Using
care, this dish can be built

with deviations of less than
0,5 cm.

Making the Ribs

The structural elements
that give the dish its
strength and special shape
are eight wooden rtbs. I
made mine from scrap
3/4-inch white pine. Each rib
was cut from a 40" x 14'*
piece. Any available substi-
tute should work, provided
that it is reasonably light
and can be cut to the need-
ed shape.

Carefully draw a center
line lengthwise. 5 8 cm from
one edge of the board, as
shown in Fig. 3. Work from
this line to lay out a
parabola, using the points
generated by the y^ = 4f)£
equation. The more points
you use, the more accurate
your paraboloid will be.
Carefully draw a line to
connect the points on the
inner surface. The outer sur-
face should have a shape
like the one shown. The

** 30

OUHETCR iM ttCTEffS

Fig. 2. Dish rf/a meter/gam relationship.

lower flat edge will be at
the center of the dish, while
the upper end will be at the
edge, fastened to a ring of
aluminum tubing.

After checking the lay-
out, the eight ribs can be
rough-cut to about 0.2*cm
accuracy using a band or
saber saw. Final trimming
should be done by sand-
ing. Be sure to keep the
flat edge parallel to the
center line.

The ribs are all joined at
the dish's center by a
3/4-inch-thick plywood
mounting plate like the one
shown in Fig. 4 Ribs A and
B are mounted first, using
1-1/2Hnch wood screws. All
the other ribs must be short-
ened to obtain equal inside
diameters. Ribs C and D

have 3/8" removed from the
inside end. Ribs E, F, C, and
H are shortened 3/8" and
mitered with two 45* an-
gles as shown in Fig. 4(a).

Finally, aft the remain-
ing ribs are fastened to
the mounting plate, first
with glue and then with
wood screws.

To add strength to the
dish's outer edge, I encir-
cled it with 1/2-inch alumi-
num tubing. Four six-foot
lengths were used. To bend
the tubing into a circle, one
end is plugged, then the
tube is filled with sand and
carefully bent into shape.
This was easier to accom-
plish than 1 thought it
would be. An undersized
piece of tubing is used for
coupling between the sec-

Photo B. A feedhorn can be easily constructed. The pickup
is a simple, nnonopole element

73 Magazine • February, 1982 89

Photo C A circular plate holds the reflective screen mg in
place at the dish's center.

tions The shaped lengths
are fastened to the dish per-
imeter with 5-cent con-
duit clamps as shown in
Fig. 4(b). Since the ribs give
the dish its shape, getting
the outside circle perfect is
not necessary.

Covering the Frame

The next step is to cover
your frame with a reflective
surface- I used 1/4-inch
hardware cloth because it
was cheap and avaiIab!e.To
make the job easier, I cut
the cloth into eight slightly
oversized triangles. Staple
a triangfe between two ad-
joining ribs and then trim
the excess outer edge to
size. Next, tie-wrap the
perimeter to the aluminum
tubing using nylon cord

with cable-wrapping tech-
nique. Be sure to wear
gloves when working with
the hardware cloth.

Once all the screen is in
place, eight flathead screws
are used to hold it on each
rib. (The staples are no
longer needed and can be
removed.) Since eight
layers of hardware ctoth
overlap at the center, they
must be trimmed and then
securely fastened beneath
a seven-inch diameter disc.

At this stage, all the
essential parts of the reflec-
tor are complete. Since my
dish is going to be mounted
in an exposed location, I
decided to strengthen it by
adding bracing between the
ribs about midway from the
center. A framework was
fastened to the center plate

so that the whole antenna
can be bolted to a mast.

Feedhorn Ideas

Because of the f/d rati
of 05, the obvious fee
choice becomes a horn. The
theory behind horn design
is not trivial. To make mat-
ters worse, there often is a
vast difference between a
design on paper and one
that works The horn shown
in Fig, 5 has been field-
proven on the 1296-MH2
band by K9KFR and others.
Horns of this type have
about 8 dB of gain. Other
types of feeds can be used;
one good source of infor-
mation is the RSCB book,
VHF-UHF Manual, by
Jessop and Evans.

Unless you can find a tin
can that meets the dimen-
sions shown in Fig. 5, you
will need to make one. Us-
ing light-weight aluminum
stock, I made a cylinder
from a 18" X 28,25" piece.
Next, a cap is fashioned to
fit into one end. Small vee-
shaped tabs are bent 90**
and rfveted to the cylinder
wall. The result is a tube
with an inside length of 16"
and a diameter of 9".

The location of the tuned
element is critical. A type-N
connector should be
mounted 2" from the rear
wall A 1/4-wave driven ele-
ment (1.8" of 1/4-inch cop-
per tubing or 1/8'' welding

rod) IS adjusted by filing.
Using approximately one
Watt of power with an in*
line wattmeter, file for best
vswr Caution: The ham is
emitting microwaves; keep
hands and eyes away from
the opening. Be sure to use
hardline for all connec-
tions.

It should come as no sur-
prise that at this point the

antenna is almost finished.
Now the horn is mounted
on the antenna frame with
four sections of telescoping
aluminum tubing.

The exact distance be-
tween the dish center and
the horn must be found
experimentally. The focal
point will not be at the
horn's outside edge, it will
be inside the cylinder To
find the exact focus, the
dish should be aimed at a
signal source and the horn
moved up and down until
the received signal is at a
maximum. If your 1296
receiving gear includes a
low-noise amplifier, then
one excellent signal source
is "sun noise.'' Aim the dish
at the sun. and your re*
ceiver should give a notice-
able output.

The antenna's polarity is
determined by the position
of the driven element.
Rotating the horn 90**
changes the antenna from
vertical to horizontal or
vice versa. When the driven

£ 1/4 in OH O^tn

FLAT ED€E

CENTER
LIME

2 \/A tn,
OR

2l/4«.0f| Q^9m

4' erf It 1^2 In 00 ALUMINUM TU&E

CENtER CUT fCm RtSS
E.r.G.K

ZH,

\Mm. HARDWARE
CLOTH

TIE WRAPPED TO
ALUMINUM TlietNC
WITH NYLOM GORQ

PLT*000

— ^ h— 3/* tn

S£€TfOf,f A -A

Fig, 3. Rib detail.
W 73 Magazine * February, 1982

Fig, 4, Assembly of the ribs.

TYPE W CQIVNECTOR

9 lA

llfp

POP RiVCTS

Fig. 5. Feedhorn design.

element is horizontal
relative to the Earth, the

antenna is horizontalfy
polarized and is set for
1296-MHz tropo operation.
Once the focus and polarity
are set, bolt everything into
place and start enjoying
your new antenna.

Life on 1 296

You might be interested
in the rest of my 1296-MHz
station. For receiving, I use
a preamplifier made with
an MRF901 transistor, fol-
lowed by a Microwave
Module that converts the
signal to 28 MHz where an
amateur transceiver is used.
On transmit, a home-brew

varactor tripler provides
3/4-Watt output on 1296
when driven with a ten-
Watt, 432-MHz signal. This
may not seem like much
power, but I make the most
of it by using hardline be-
tween the dish and the
shack, Thanks to my dish
antenna, the 1 296 effort has
been a success. The first
two contacts were with
K9KFR and WA8|HW. each
more than 100 miles away.
This article is being writ-
ten in the winter, and the
dish has been stored away,
safe from ice and other haz-
ards. When warm weather
returns, you can be sure
that W8DI Y will be back on

Photo D, Building a 1296-MHz dish need not be difficult,
but it will require sonne home-brewing.

1296, In the meantime,
plans are being made for a
much bigger dish and a
more powerful transmitter.
As you can see, build-
ing a dish need not be
difficult. This project was
the result of a lot of help
and ideas from fellow VHF-
UHF enthusiasts, including
WB8EEX, whose garage
proved invaluable, W8ULC,
who handled the fancy foot-

work on the tower, and
K9KFR, who patiently
helped get a feed that
worked.

About the only thing that
can't be changed is the ba-
sic parabolic shape Make
the most of the materials
that are available in your
area; be brave; experiment!
If you have questions,
please include an SASE. See
you on 1296IH

ESR24 Earth Station Receiver

«***!■<

*■

« f

Full-perforinance Satellite TV Receiver

► All 24 Satellite Channels *» Attractive Styling • Digital Display * Up/Down Channel Button Control

• Fixed and Varrabfe Audio Tuning for all Subcarriers • Normal /Inverted Video Switching
Signal and Tuning Meters - Single and Doubie Down Conversion Models • Afc for drift-free operation
• Remote Control and Remote Metering Options • Suggested List as low as $995.00

Write for brochure or see your desler.

540 Richard St Miamisburg. Ohio 45342, USA
Phone {51 31 866-2431 • Tetex: 288-D1 7

R.L.DRAKE COiWiPANY

DRAKE

FEATyfl£S AND PRaC^S SUBJECT TO CHANQ& WrtHQUT MCfTig^ QR OmJQMiOH

73 Magazine * February, 1982 91

Richard Christian WA4CVP
Rl h Sox 209-W
Creota AL 3652S

5. f. (Mitch) Mitcheli, Jr. WA40SR
TO Box 973

MobihALSSem

Job's Own LNA

rolling your own takes patience

Yes. it is possible to
home-brew a workable
LNA (Low Noise Amplifier)
for your home-brew satel-
lite TV receiver! But to do
it, you must have the pa-
tience of lob and start with
a full head of hair!

We'll let you, the reader,
decide as you read the arti-
cle just how much patience
we have.

In ham radio receiver
terms, the LNA is the "front
end" of the satellite receiv-
er. Commercial units gener-
ally have about 40 to 50 dB
of gain at 4 GHz. They usu-
ally are constructed of one
or two stages of CaAsFET

OHAfrTCOMM. UfCs

transistors and several
stages of bipolar transistors
to achieve the amplifica-
tion desired. The CaAsFET
transistors are a special
type of transistor with a
very low noise figure. They
get their name from the ma-
terial used to achieve the
low-noise figure, gallium
(Ga) arsenide (As).

This article describes the
trials and tribulations that
we went through in building
the LNA for our satellite-TV
receiving system. Although
we had access to absolutely
no test equipment for 4
GHz until after it was
known to be working, we

111914 tOpf

I W f )h-

555

■fflj

5«ie

lit

were very successful in get-
ting the complete system
going. We wish to share our
hard-earned information
with 73 readers who are
considering building their
own systems.

First, a tittle history. Our
initial attempt to build an
LNA used a commercially-
available board which, for
reasons to be discussed,
will be nameless. The board
was supposedly designed to
work with Nippon Electric
Company (NEC) NE21889
GaAsFETs. These FETs are
expensive at $103 25 for
two, but they have a noise
figure of 1.2 dB at 4 GHz.

«1 TAUT

ADJ. FOR ITV

« • *U TO *iOY

f 1

.01

/ft
9V

TPC /^

TE$T TOlNT

-'lAfSp (*

— vw*- ♦

3.av

3.9V

ji^an

ZlN3l4 ZlN9H

St QZ

TPZa-

LHltTT

39V

-' p^

TO GflTE^

■ TO DRAIMS

Fig. 1. Bias supply schematic.

73Magaifne • February J 982

So, being the scroungers

that we are, we attempted
to substitute cheaper (high-
er noise figure) GaAsFETs.
The result was two blown
FETs that cost $62,50 and
two grown men crying. We
then bit the bullet and
ordered two of the NEC
FETs from its US distrib-
utor, California Eastern
Labs(CEL).

With cold, dry weather,
we were in a real dilemma.
How do you protect a hun-
dred bucks worth of minute
transistors from static elec-
tricity while you are solder-
ing them into the circuit?
We finally decided that we
needed a work area with a
good ground and high hu-
midity. Richard's front
bathroom was selected to
be converted to a reduced
static work area. We turned
on the hot water in the
shower to steam things up.

A piece of copper braid
wrapped around my wrist
and grounded to the cold
water pipes provided the
ground needed, A large
piece of copper^covered PC
board also was grounded to
the cold water pipe and was
used as the work surface.
We let the soldering pencil

heat up and then un-
plugged it from the ac line
and grounded it with a
jumper to the work surface
for more static protection, f
quickly soldered the first
transistor in before the iron
could cool. After I stopped
shaking, we reheated the
soldering pen and 1
soldered in the second tran-
sistor. It's amazing what
lengths you will go to when
a hundred dollars worth of
FETs are at stake.

The LNA was mounted in
a box made of double-sided
PC board, with feedthrough
capacitors supplying the
correct operating voltages
from a very simple resistive
divider power supply. Next
we gave the LNA a try. It
wailed like a banshee! In
other words, it acted more
like an oscillator than an
amplifier.

How did we tell that it
was oscillating without us-
ing test gear? We discov-
ered that any oscillation
within the 3J-to-4.2-CHz
band is immediately ob-
vious on a TV connected to
the receiver. If the oscilla-
tion is strong, there will be
very prominent black bars
on the screen regardless of
where the local oscillator is
tuned- If the oscillation is
weak, there will be a very
weak but still visible black
bar. Black bars will occur
twice, 70 MHz apart, within
the tuning range of the
local oscillator, if you are
using a single conversion
receiver (since you get both
the signal and its image).

If the oscillation is out-
side the tuning range of the
TV, however, it will not
show up on the TV screen.
If you can't see it on the TV
and if you don't have a
spectrum analyzer to test
with, how do you know that
it is still oscillating? Noise,
noise, and more noise at the
70-MHz i-f stage.

What to do with the oscil-
lating LNA? Start over! We
wrote California Eastern
Labs for their Application
Note AN80903 that de-

scribes an LNA using the
NE21889S. A prompt re-
sponse from CEL brought it
to us. In the CEL design, the
LNA was mounted in a ma-
chined-brass enclosure. We
could not immediately lo-
cate any half-inch-thick
brass to make the enclos-
ure, but Richard, scroung-
ing through his junk pile,
located a short piece of
copper bus bar which was
suitable, A little persuasion
was applied to a local
machine shop and presto,
we had two nice machined-
copper enclosures.

Since we thought it
would be impossible to re-
move the GaAsFETs from
the first LNA board without
destroying them, we or-
dered two more NE21889s
from CEL. At $103.25 for
the pair, this project was
getting expensive!

Richard arranged for a
local print shop to make
negatives for the printed
circuit board to within .002
inch of the dimensions
specified in the CEL Ap
Note. We quickly made a
board and waited for the
second pair of transistors
to arrive.

While waiting for the
transistors, we did some se-
rious thinking about a pow-
er supply for the LNA. As
previously mentioned, we
had already zapped two
''cheap'' FETs. We wanted a
reliable LNA power-supply
design that would protect
the expensive little buggers.
Many hours of design,
building, and testing of cir-
cuits by Richard resulted in
the LNA power supply
board described here. We
call it our "How Not to Gas
Your FETs Bias Supply
Board/' It was designed
specifically for a two-stage
LNA using the NEC 21889
FETs.

Some criteria for the de-
sign: It should —

• Supply +3 volts for
the drain and —3 volts for
the gates.

• Power two stages of
CaAsFETs.

Fig. 2(al PC-board layout

+ v

Fig. 2(b}, Parts placement

• Require only one pair of
wires for the LNA so the
supply voltage, with proper
blocking, could be carried
on coax cable.

• Provide reverse polarity
and overvoltage protection
for all gates and drains.

• Regulate gate bias and
drain voltage with a main-
supply voltage falling any-
where between +15 and
+ 30 volts.

• Have most parts avail-
able from Radio Shack.

The circuit described in
Fig. 1 meets all of the de-
sign criteria. The input volt-
age, which can be from
+ 15 to +30 volts, is ap-
plied to an LM317T adjust-
able voltage regulator,
which reduces it to +3,7
volts. The + 3 J volts is then
filtered by a 1-uF tantalum
capacitor and fed through
33-Ohm current-limiting re-

2f bHar^^AAMlMS^^Ad**J f I

CAPACITORS

-4h

4i — ^i(-

"Th

]OUT

'^h?.

|^]ch3 []'Ch4

( ^

/f?

CASE Sl&E

TO BIAS BOARP

62 D^

TO BEAS BOARD

Fig. 3. Typical GaAsFET amplifier schematic.

I Ip^t

fig. 4. Typical LNA board layout (not to scale).

73 Magazine • February, T9S2 93

HEjff.ll^NK

::2Toa

L4 Jllff^
SOPiV

*I|V
COMPLETE

taht

fig. 5, Receiver power supply schematic.

sistors to the drains of the
two CaAsFETs. The test
points on each side of the
33-Ohm resistors are used
to measure the voltage
drop across the resistors
and, therefore, the current
being pulled by each FET. A
voltage drop across the re-

sistor of 33 volts equals 10
milliamperes of current be-
ing pulled by the FET. A
3.9-volt zener diode limits
the maximum drain volt-
age, and high-frequency
filtering is provided by the
,01-yF capacitors. The
voltage is then fed through

IN 91 4 diodes for reverse
voltage protection. This
completes the drain supply.
We decided to generate
the required negative volt-
age from the positive sup-
ply instead of going with a
bipolar supply. Past experi-
ence has proved that for us,
the negative-voltage regu-
lator always fails first. With
no negative bias, high-drain
current would probably
result, zapping the expen-
sive FET. For the gate sup-
ply, the +15 to +30 volts
is applied to a 78L12 regu-
lator. The regulated +12
volts is used to supply a

Fig. 6fa| Receiver power-supp/y PC board layout

TANT

Fig. 6(bl Parts placement

NE555 timer iC configured
as a free-running multivi-
brator. The output of the
555 fs rectified with a volt-
age doubler and filtered to
give a negative voltage for
the gate bias. The negative
voltage is applied to two
lOkOhm ten*turn pots. The
zener overvoltage, diode
reverse-polarity protection,
and high-frequency filtering
are the same as for the
drain supply. A PC-board
layout and parts overlay for
the LNA power supply are
shown in Fig. 2.

Everything was now
ready for the arrival of the
second pair of FETs. When
they arrived, Richard
soldered them in using a
Radio Shack battery-
powered, isolated-tip
soldering pen that we had
purchased for working with
the CaAsFETs. By having
Richard solder these in, we
discovered that the guy
who supplies the money for
the FETs shakes the most
when soldering.

After assembly of the
bias supply board, but be-
fore connecting it to the
LNA, apply +15 to +30
volts. With a voltmeter, ad-
just pot R1 for + 37 volts at
the test point IPC (Test
Point Common). This will
result in approximately +3
volts to the drains after the
.7-volt drop across the re-
verse-polarity protection di-
odes. Set the 10k bias pots
for —3 volts at points G1
and G2,

The supply is now ready
for connection to the LNA,
using the isolated-tip, bat-
tery-powered soldering
iron, with the tip grounded
to the LNA board Refer to
the "typical" LNA schemat-
ic. Fig. 3. Be very careful to
connect the gate leads, CI
and C2, before connecting
the drain leads, D1 and D2.
With a voltmeter across the
33-Ohm resistor, + probe
to TPC, — probe to TP1, ad-
just G1 bias for a 33-volt
reading. This indicates that
10 milliamperes of current
is being pulled by the

S4 73 Magazine • February, 1982

CaAsFET. Move the —
probe to RP2 and adjust the
G2 bias pot for a 33-volt
reading, Now go back and
check FET #1 . As you adjust
the bias pots, the current
should evenly increasel If
the current jumps or is
erratic, the LNA is probably
oscillating. How to stop os-
cillation is the subject of
another article!

Using the above-de-
scribed LNA power supply
and tune-up procedure, the
CEL LNA design came up
beautifully, with no oscilla-
tion. Its two stages gave a
solid, measured 21 DB of
gain. We were unable to
measure the noise figure di-
rectly, but the fellow with
the test equipment said that
it appeared to be very low,
based on his evaluation of
the ratio of gain to noise
generated by the test
equipment

What type of picture do
you get with a two-stage,
21 -dB gain LNA that has an
unknown noise figure? Very
poorf After getting the first
CEL LNA working, Richard
was able to remove the
NE21889S successfully
from the commercial
board, We built up a sec-
ond board, using the cell
design and our LNA power-
supply board. Again, the
CEL design came up with
absolutely no problems.
Now, by cascading the two
boards, we were getting
some results.

After optimizing the
boards, which I will cover
r>ext we have numerous
transponders on SATCOM I
above noise. We are locat-
ed in the 32-33-dB footprint
and the antenna is a home-
:>rew 12-foot spherical. We
lave made comparisons of
>ur four-stage CEL LNA and
i 120-degree commercial
-NA. Our home-brew LNA
lompares very favorably
vith the commercial unit.

rrimming an LNA for Best
sloise Figure and Best Cain

After having gone
hrough the misery of trying

'See Ltst of Advertts&rs on page 714

to build an LNA with almost
no information and abso-
lutely no test equipment,
we now can describe some
of the procedures we had to
discover the hard way.

The first step is to pre-
pare a work area so that
you minimize the possibili-
ty of blowing those costly
CaAsFETs. A piece of print-
ed circuit board makes an
ideal work surface. Again,
you will need a good isolat-
ed-tip soldering pen.
Ground the tip of the pen to
the work surface with a
jumper. The battery-
powered pen sold by Radio
Shack works great. You
should ground yourself to
the work surface with a
piece of copper braid. You
also will need an X-acto®
knife, a BB or small ball
bearing, a plastic tuning
wand, and a steady hand.
Clue the BB or small ball
bearing to the end of the
plastic tuning wand.

The LNA, as built should
produce watchable video in
most areas of the country.
With power on and a tran-
sponder tuned in, make
sure that the correct cur-
rent is set for each stage of
the LNA (10 mA per stage
for the NE21889). You
should monitor the current
of each stage as it is
trimmed. Place the BB on
the PC-board trace edge as
per Fig. 4. Slowly move the
BB around the outside pe-
rimeter of the striplines,
keeping it in contact with
the stripline. Monitor the
quality of the received pic-
ture as you move the BB.
When a point is found
where the picture quality
gets better, you need to add
copper to the stripline. If
the picture quality gets
worse, you need to remove
some of the stripline by
making very light cuts. We
only score the copper with
the X-acto knife so that it
can be soldered back to-
gether if needed. Make sev-
eral trips around the strip-
lines and note the effect

TELEVISION

WE WILL NOT BE UNDERSOLD!!

Complete Systems, Antennas,
Receivers, LNA's & Accessories
CALL US TODAY! -320

812-238-1456

hoosier
electronics

*'Nation*s Largest Total Communications Distributor''
P.O. BOX 3300 • TERRE HAUTE, INDIANA 47803

before doing any adding or
trimming, Make a log of the
points where changes occur
and see if they repeat each
time you run the BB by
them. After you are con-
vinced of the points that
need changing, then make
the necessary adjustments.
Copper can be added by
salvaging a piece of foil
from another piece of PC
board or by using GC Elec-
tronics Silver Print paint.

After the adjustments are
made, make a slight in-
crease in the current for
each FET stage while watch-
ing the picture quality. We

have run the current up to
40 milliamperes on a stage
with no oscillation. The first
stage will probably have to
operate at 8 to 1 2 milliamp-
eres for best noise figure.
Successive stages can oper-
ate at higher current levels
for more gain.

The basic power-supply
design (Fig, 5] and PC board
layout (Fig 6) power the bias
board and also our com-
plete satellite TV receiver.
There is nothing special
about it except, again, that
an effort was made to use
parts available from Radio
Shack. ■

Printed circuit boards are available from IVIartcomni, Inc.,
PO Box 74, Mobile AL 36601, for the power supplies and the
LNA. The LNA board is $20.00, the LNA bias supply board is
$t2.00, and the receiver power-supply board Is $10.00. Add
$1J5 per order for first class postage.

You may request the CEL LNA Application Note ANa0903
by writing to Caiifomia Eastern Labs at 3005 Democracy Way,
Santa Clara CA 95050. A copy of the Note is supplied with
each LNA board ordered from Martcomm, Inc.

73Magazine * February, 1982 95

BifiyL Nlehen W&4APC
Rte 2, Box ISll
Raddiff KY 40160

Microwave Master

you might not need a mountaintop

With the growing inter-
est in satellite televi-
sion reception, weather pic-
ture reception, and higher
frequency utilization, the
need for a better under-
standing of microwave prin-
ciples becomes more im-
portant than before.

To better understand mi-
crowave techniques, we
must first understand the
frequency bands and the
characteristics of the mi-
crowave spectrum in rela-
tionship to other lower fre-
quency radio waves. As we
know, radio waves travel
mostly along the ground
path and are not readily af-
fected by mild changes in
the weather or atmosphere.
When we get into the mi-
crowave region, the charac-
teristics are entirely differ-
ent

To begin, let us take a
look at what microwaves
are. Radio wayes above the
lOOfrMHz level are called
microwaves. It is a common
practice to relate to this
portion of the frequency
spectrum in terms of Giga-
hertz (GHz), With a frequen-
cy of 1000 MHz being equal
to one Gigahertz. The basic
spectrum of microwave fre-
quencies is made up of

three very basic bands.
These bands are: the S-band
centered at about 3000
MHz (10 cm), the X band at
about 10.000 MHz {3cm),
and the K-band at about
27,000 MHz ni cm).

Table 1 shows the rela-
tionship between the bands
by wavelength in both cen-
timeters and inches, and
Table 2 shows some of the
services operating there.
You will notice from the
table that a full wavelength
at the microwave frequen-
cies is not very long. When
we get into working with
the construction of micro-
wave equipment and subas-
semblies, these measure-
ments will have a very
significant meaning.

The first cavity magne-
tron was developed in
Great Britain in 1940, after
the publication in 1936 of
two papers on hollow wave-
guides. These papers are:
"Hyper-frequency Wave-
guides—General Consider-
ations and Experimental
Results" by G. C. South-
worth, and "Transmission
of Electromagnetic Waves
in Hollow Tubes of Metal"
by W. L. Barrow. During the
period of early develop-

ment around 1940, most of
the experimental work was
carried on in the Radiation
Laboratory at the Massa-
chusetts Institute of Tech-
noIogy> During this time,
almost all experimental
work in microwaves was di-
rected towards the design
and use of microwave radar
equipment, due to the
small size of antenna equip-
ment required in the micro-
wave region.

After the second world
war, more efforts were
made in other areas to the
extent that today, almost
all long-range telephone
communications are re-
layed by microwave links
As scientific advances be-
gan in outer space, the role
of microwaves became
even more important. In
fact microwave technolo-
gy has made possible many
of the products used today
in our homes, business, and
in private industry. An ex-
ample of a modern use of
microwave technology is
the microwave oven found
in many homes and busi-
nesses.

Microwaves are also
used in many of the security
alarm systems found to
business use and have been

used by private industry for
some time for cleaning of
parts, removal of broken
screws and bolts, and for
controlling signal devices
at railroad crossings and
drawbridges Another use
with which almost every-
one IS familiar is the radar
speed control devices used
by police forces all over the
country.

To understand micro-
wave principles, we must
first take a look at some of
the characteristics of mi-
crowaves in relation to
other forms of radiation.
We must also learn what
variables affect the micro-
wave signal itself

To begin, microwaves
normally travel in one or all
of four basic paths. These
four paths are direct wave,
reflected wave, surface
wave, and sky wave. In
most microwave installa-
tions, the direct wave is the
desired path, although the
reflected wave also may be
of importance in some in-
stances.

The direct wave is so
named because of its direct
path from one point to an-
other. With optimum condi*
tions, the most reliable
communications can be ob-

96 73Magaiffte • February, 1382

Band

Frequency
(MHi)

Wavelength

cm Inches

S-band
X-band
K-band

3,000

10,000

27,000

10 4

3 1.2

1.1 .44

Service

Fi«quency

Amateur

WEFAX

MDSTV

Table 1. Microwave bands.

tained through the use of
the direct wave.

The sky wave normallY is
considered to be a wave
that has been reflected
from the ionosphere, a re-
gion that extends from an
altitude of approximately
30 miles on out to about
250 miles. In the area of sat-
ellite television or weather
fax, a signal which is trans-
mitted from a satellite is
not considered to be sky
wave but instead, falls un-
der the classification of a
direct wave that has been
retransmitted.

Surface waves are waves
that travel along the sur-
face of ground or water.
They are mostly predomi-
nant at the lower frequen-
cies. At microwave frequen-
cies this mode of propaga-
tion is usually insignificant
and in most cases may be
disregarded.

The reflected wave is a
wave that has been reflect-
ed from the land or water
surface of the area between
the transmitter and receiver
antenna sites. A factor that
determines the strength of
the reflected wave is the
type of surface that the
wave is reflected from.
Land is considered to be a
poor reflector and will scat-
ter the wave in many direc-
tions. Water is a good re-
flective surface and gener-
ally will reflect the entire
wave in one direction. The
reflected wave is only im-
portant when the reflected
signal is picked up at the re-
ceiving antenna with a
strength comparable to the
strength of the direct-wave
signal. At this particular oc-
currence, the reflected
wave may either boost the
direct-wave signal or cancel
it almost completely. The
determining factor at this

t^See Ust of Advertisers on page 7^4

time is whether the two sig-
nals are in phase with each
other. If the two signals are
in phase, or nearly in phase,
or if the two signals are of
nearly equal strength, the
combined signal can be
twice as strong.

However, if the two sig-
nals are nearly 180^ out of
phase with each other,
there will be a reduction in
signal strength since the re-
flected signal will cancel
some of the strength of the
direct-wave signal.

A phase difference be-
tween the direct wave and
the reflected wave is usual-
ly introduced by the dif-
ference in the distance
each wave travels. This dif-
ference may vary from in-
stallation to installation
and can be anything from a
fraction of a wavelength to
many wavelengths. When
the path difference is an
odd number of wave-
lengths, the two signals
{direct and reflected) will
arrive at the receiving
antenna in-phase. This is
especially true when the
wave is reflected at small
angles of incidence, which
cause a phase reversal of
1 80®. In the case of horizon-
tal polarization, the phase
reversal is nearly 180*' re-
gardless of the magnitude
of the grazing angle^ This is
also true for almost all in-
stances of vertical polariza-
tion in most point-to-point
communications systems.

An interesting fact about
microwave energy is that
the signal tends to be slight-
ly curved. This is because
the signals travel through
the atmosphere at speeds
that depend on tempera-
ture, atmospheric pressure,
and the amount of water
vapor present in the
atmosphere.

1296 MHz
1691 MHz
1900-2600 MHz

Satel I ltd TV 37004200 M Hz

Table 2. Some services operating in the micfowave

frequencies.

Wivelength
cm Inchei

23 ai

17,8 7

15.8-12 6.2-4.7

fr7 3,2-2.8

The following three con-
ditions will have an effect
on the microwave signal;
The higher the temperature,
the faster the signal; the
lower the atmospheric pres-
sure, the faster the signal;
and the lower the water
vapor content, the faster
the signal.

With these influences,
the net result is that the
signal speed changes with
altitude. Under normal con-
ditions, the variation is a
small and uniform increase
in speed of the signal with
an increase in altitude. In
this manner, it readily can
be seen that in a way, the
microwave signal acts very
much like a light beam. Just
as a light beam can be re-
fleeted or bent, so can a mi-
crowave signal be reflected
or bent.

Using the above informa-
tion, we also can see that
microwaves can be very re-
liable for communications
systems. The most impor-
tant factor is to ensure as
direct a line-of-sight path
from the transmitter anten-
na to the receive antenna as
possible. With prior study
of the potential path, it is
really not too difficult to
plan a microwave system.
The thing to keep in mind is
that the complete path of
the microwave signal must
be free of any obstructions
such as trees, hills, or tall
buildings. When transmit^
ting over water, the reflect-
ed wave may play an impor-
tant role in the received sig-
nal. When you are design-
ing over-water point-to-
point systems, it is very im-
portant to ensure that this
reflected signal does not ar-
rive at the receive antenna
in an out-of-phase or nearly
out-of-phase state.

A simple rule-of-thumb
method can be used to de-
termine possible antenna
heights, especially for over
water paths. The antenna
heights chosen must satisfy
the following relation:
/2lTi + /2lT,= S, where
H, and Hi represent the an-
tenna heights in feet above
sea level and S represents
the distance in miles be-
tween the antennas.

The next step is to calcu-
late a correction height
using the formula H =
n/S/F, where H is in feet, S is
the distance between the
antennas in miles, and F is
the operating frequency in
MHz. The required antenna
height for each antenna is
the sum of the tentative
height and the correction
height for each antenna, or,
more simply stated, H, + H
and Hi + H. If the values
obtained are not conve-
nient, then select new ten-
tative antenna heights and
perform a new calculation.

For example, if we as-
sume a transmitting anten-
na height of 1 400 feet and a
receiving antenna height of
2000 feet at a distance of
100 miles, the computation
would be: V 2(1400} +
V 2(2000) = 100 (miles). The
square root of the H^ com-
ponent is 52.92; the H^
square root component is
63.25. This gives us a total
of 116,17 miles. It is then
quite evident that one or
both of the contemplated
antennas are too high. By
using the S value of 100 and
working backwards with
the formula, using Ht as the
base antenna and recom-
puting for Ha height: 100 —
52.92 = 47.08 squared =
2216.53 divided by 2 =
1108.26 feet. Therefore, the

73 Magazine • February, 1982 97

STATE-OF-THE-ART

Quantity discount price structures available upon
request for dealers. Dealerships, both domestic
and foreign available in many areas. For further
information, please contact John Michaels, Sales
Manager. Telephone hours: Monday thru Thurs-
day, 10-4.

ELECTRONIC

4558 Auburn Blvd., Sacramento, CA 95841

(916)452-0193 ^ ri

new height that meets the
relation is 1108 feet for H^.
By the same token, we
could have kept antenna H j
at the height desired and re-
computed the height f or H i .

Using the corrected fig-
ures for antenna heights of
1400 feet for H^ and 1108
feet for H^, v^e now can
compute the correction
heights for both antennas at
a frequency of 1296 MHz:
H = 660V 100/1296 =
183J3333 feet. This gives
us a final figure of antenna
height for H| of 1400 +
183.33 or a total of1583J3
feet and for Hi 1108 +
183,33 ora total of 1291.33
feet. Given the figures
above, we can now look for
possible sites to install
antennas.

Of course, we may not al-
ways find the ideal spots for
our antenna construction.
In this case, we go back and
recalculate using different
antenna heights (plus eleva-
tion above sea level) to ob-

tain 3 relative figure equal
to the desired distance fig-
ure. Sometimes just one or
two feet may make the dif-
ference at the receive end.
In any attempt at micro-
wave, if at first you do not
succeed, try again at anoth-
er location or change the
height of one or both of the
antennas. In selecting a
good antenna site, a very
good aid to locate the ideal
sites is a topographical map
of the area locality of
choice. A source of infor-
mation for obtaining topo-
graphical maps is at your
state capital. Try writing a
letter either to the State De-
partment of Natural Re-
sources or the State Forest*
ry Division. There is a fee re-
quired for copies of these
maps, but it is usually very
small when one considers
the information that can be
obtained and the time that
can be saved. Happy ham-
ming on the microwave
bands.

Hm HELP

I am in need of the schematic
and alignment information for a
Gonset G'77 transmitter and in-
formation on a TU-8-B plug-in
unK used with 8C1 91/375 trans-

mitters, I will copy and return
your originals,

Howard Palmer WfflRT

1125 Basswood Land

St Louis MO 63132

I am looking for employment
in the electronics field, in the
Knoxville-Chaltanooga, Tennes-
see area. My background in-
cludes 25 years of experience
with rt circuits, and 1st phone
license with radar endorsement,
and an Extra amateur license.

Herman F. Schnur

115 Intercept Ave.

N, Charleston SC 29405

I am giving away, free, in ex-
change for postage, a
R336/GRC26 army receiver and
6K7, 6J5, 6R7, and 6C6 tubes,

I am looking for ar> Ameco R5
receiver and schematic for
same. Please state condition
and price,

Kevin Keal

Route A, Box 211 A

FJIppln AR 72634

Satellite TV

FOR THE HOME
Sick of Network TV?

Qur receiver lets you get
over 75 channels of tele-
vrsion di rectly from earth-
orbiting cabEe TV sataJ-
I ilea! : HBO, Showtime, su-
per stations, sports and
movtes wcrldwide.

We don't just
sell information!
We Manufacture
Hardware!

From offshore oil rigSn
data links to hotels
and backyard instal-
lations, we wrote the
book, Constantly up-
dated, our 94 Pag«
technical information book and catalog gives you all
the facts. Inexpensive dishes, feeds, telem-
etry software, kits and more. Recom-
mended reading by NASA^ The Office
of Consumer Affairs and quality com-
panies iike Rockwell/CoMins, Send
$7.95 today! ^^^^ ^^309

24-hn. Q.O.D. HQlttn9
fSDS; 339-7600

SPACECOAST

RESEARCH CORPORATION

P.O, Box 442-0, Aftamonte Spgs, FL 327Q1

HEATHKIT
SB-104A OWNERS!

Improve BOTH RX and TX Perform-
ance Greatly! See Article in April 1981
Ham Radio Magazine.

ALL parts now available from a

SINGLE Source. Buy the Kits you need.

Complete Instructions,

FTH-1: RX SensUivity tmprovBment. .... $13

FTH-2: RX Mixer Improvement ........ $15

FTH'3; Selectivity Improvement* $60

FTH-4; Strong Signal Handling. ... $10

riH-b: TX Switclimg & Audio. $5

FTH-A: All above^ with Coax Only $100

•Includes &;^cellem 8- pole Fo;( -Tango Filler

OFder wlt?T Ccinilidence — Mon&y Bac1< Gu^ranlee

We accept Visa/Masi^rCard

Fof Airman id uS/Cartaaa sOQ $2, Elsewhere 15

FREE' Complete Instructions. Send Lafge SASE (or £1 j

FOX TANGO CORP.

Box 15944&, West Palm Beach, FL 33406
Phone: <305) 683-9587 <323

PRESERVE

Peterborough nh 03458

Keep your i&sites ot 73 Magazine togethef, handy
and protected In handsome and durable Hbrary files
or binders. Both styles bound in r&d leatherette with
the magazine logo stamped In gold.
Files: Each file holds 12 issues, spines vislbia

for easy reference, ¥&.95 each, 3 tor $17.00,

6 for $30.00
Binders: Each binder holds 12 issuas and opens

flat for ea$y reading. $7.S0 each, 3 for S2175,

6 for $42.00
(Postage paid In USA. Foreign orders Include $2.50
per item^

Please state yearsi 1977 to 1963
Send check or monay order to:
JESSE JONES aOX CORP.
P.O. Box 5120
PhifadelphJa, PA 19141
Allow 4 to S weeks for delivery

9S 73 Magazine • February, 1982

Enjoy Satellite TV Now

•v

Better than Cable TV -Over 200 TV and radio
services Why waste money ^ Learn the whole
story and build a video system the family can
enjoy No commercials. FREE movies, sports
and Vegas stiows — worldwide, crystal clear
reception connects to any TV set . Big (8 x 11 in . )
book loaded with details, photos, plans, kits—
TELLS EVERYTHING f Satfsfadion Guaranteed.

Send S7.95 TODAY! Add S2.00 tor isi class lair mail) or call
our 24 hour COD rush order line |305) B6Z-5(f6a.

GLOBAL ELECTRONICS,

RO. Box 219>H, Maitland Florida 32751

Uye l/IA SATELUTE

399

COMPLETE
(fECEiVlNC
SYSTEM

mKmemwmm

MOD i^It{!/MD^

JU5I PUBLISHED: $'A X 11
BOOH givis a mbICI of ip-

datid liforvatipi on «
Aitfiiis • RKtlvin > Low

il»lM iflpUfllK - SHiKtf

* sirfket • fq«LiiiHit •
Mainffietinfj • miicb i«ri.

Our book t3J(« the mystery out of the sophisticated technologv
of satellite transfnissioFi and rneption This volume represents ail
the essential knowledge msit t^sv to iidifstaid, and will show
you how easy it is to liawe a 90 channel reception system so that

you cai enjoys first run movies, foreictn films, Las v&gas enter-
tainnnent, live sports, and muci more. Everything ijeing telecast
in the world could be vours at a twist of a knobf

UMOWR tsao

uwm wiM mATSLurm, inc.

P O. Box 2561, Depl M-2, Delray^ Beach, FL 33444

Send $9,95 prus $2.60 shipping & handling
qr call our 24 hr. QO.D. order line (305) 845-4447

Name _^

Address

MICROWAVE ANTENNAS 'i.

PflFlft&Dt.JC ANFENnfiS FOIl SJiTELlTl FtCfPTIW, PplNT TO *fliHl,
OR HCCROMM A.t,-V. \ifM.-

n fOOl »[-5ft H'it* trfflcm nount iar fninl point

um.fla

?\lLf» i*H)ftT f<fr i*t«l 1 tt t..<i.

U4«,(»

HCTOIIIILD I'OLflfit rCiyiiT nun CBflimot u*"t

;i?M.(B

l<HOHI£ED KlIUTH - titl/ATISh HQlMT

.it%s.oa

e F[»T Dl^N

iJ5JJ,CO

FlilfLD-. [Di£t: rtOsjtr

|]iO,C»

TDiJER TOf^ H'tL M&::t.:T

lAlt.fSi

4 rOCT D'C^li o&ii -Sine munlt m. ^ fact diiti

Sf^fl.OD

TBCPliD H3b«T tor Tuofme iflulliftB flf *«*•!

.si™;flo

ja Inch aiiH i^unts id Cimfm trli^ad

Tw>:dd

Ki- RErilCTOPi. r-ACi: -DF rerii JWWfihATIJl F[HE«S5LWi. a* I
rtftfllJ^WE TBEAtED FOB CftflKK-JM KSl St JWCI .
FLLilPl>l;rHT fC* Hasr rft£.&llENC]eS ftMA]LffiL£ DM HfOilESr.
S«IPP]Nt IT IJl^i OS HCffm itlEiOIT flLLOW 6 «tEKS FOR ULlVEiiT
CALi FDH <lORf IHFO (?&S] ??^',«i6|t ^ W tO. Spin tnoiptlir tlM.

PRICES SL-&JtCT TO dtWttt M TO HATEP-tW. 1CST5

1^327

NORDLUND & ASSOCIATES

;!JU i*NP] PlKEi KUiHA JiJfti>;. n36M

JOrt r. HDMLUIID ^UlKt^

+ ♦■-■#—

s : I ■ ■ I

? I 1 r ■ .Is" ■ : I i

Introducing the Model 7600 Satet

eiver: New

3|ilbspie bM2

iBtistic^arid ease of op^rfifionfCaM^ Ajtl^^'^'^^'S'

4, ^

^ Receptiori 3700 to 4200 MUz^
4 Built-in video modulatoi? \ \ \\ ] :

- f'

f4^^tM^Hls

. I...X .

._ jS0€^ri 1pd?iy and experienice the difife|r|r^^ppt^

1-L-

JmpfdvJB^ videcj) senisitiUt^

;"j»i Ait wood walnut cabinet^,

hihe Model 7600SatelIhG Receiver System Paid^Spteisfii^W^^

cable a

i J = ; t

"^ ^^1 — I — I — I — \ — I — I — '

inbu^ted Image Rieject Mixer {DqwniGonveiit<>]l);;lQ^'5Q^
; iQO' of Bdden DC cable with corinfBctbrs! mst^lled' ■ *"

GEt^ THE LAST WORDTlRStl'' LtHtii
XQIUR qilM§P||£^ A^pPPPATEiS DEALER^!

I i } \\-\ Khi Hj- i -j-tj- i ill i M 1 1

- ^—' ' ' '■ • ' • '' ' ' ' ^- -i- --- -L- -L ...■^■: -L

The Luly ANTENNA
and POLARIZER

Completely portable Antenna, comes fully assembled (folds like
an tjnbrella and is not a kit).

The Polarizer is an electronic rotator, which
can change polarities with a flick of a
switch [no moving parts). Eliminates weight,

twisting cables, freeze
ups, and down time.

LULY TELeCOMMUNICATIONS CORP.

P.O. Box 2311, San Bernardino, California 92406

(714)888-7525

Dealer and Distributor Inguirtes Welcome

See Usi of Advertisers on fiage 114

73 Magazine * February, 1982 99

SATELLITE TV SYSTEMS

"COM PARK OlIR QUAl IT\\ PRICf:S AND StRVlCEr'

WKMAMiFACTtRt:

PARABOLK DISHES
POL AK MOUNTS
DEMO TRAILERS

WASHBURN

AVANTF.K
UAjfl DINER

MOTORIZATION SYSTEMS
LNA HOLDERS
ALUMINUM HORNS

ALLIANCE

ATV

CABLE & CONNECTORS

SWITCHES &. HARDWARE

CALL, WttrrLOK ^ frOR OJIR LATKS^T PROtHlitL AND FRICfrJ^.

AUSTIN C. LEWIS LEWIS CONSTRUCTION CO j^457

K4CGC P.O. BOX UX)

901 7S4'2I?1 HUMBOLDT, IN. ?S345

MN BLSINLSS AT IHl^ LOt ATICJN SINCE 1%4"

♦* AZDEN

AVAILABLE NOW

PCS-300

TWO-METER HANDHELD

KDK

atso: 2025A MR II
(W/TT micj

$290.00

PCS-300 HT $290.00
PCS-3000 XCVR 290.00
eemot* cable 37-00

Phase n ant. 28.50

Other ace. Call

Frea ahlf)pin§ in U.S.A.
tof all XCVR or HT ordars

B. Q. CARL ELECTRONICS

11128 Claire Ave.
Northndo«i Calif. 91326
Call: C213} 363-1216 - anytime

s^4€9

ALL NEW
1 5 Meter Mobile CW & USB

21.000— 2 1.450 MHz

High (OW (PEP) low 2W (PIP): VFO tuning; noise blanker; fine-
tune SB^ KHz ± CW of f-5et; digital frequency counter; J 3.8V dc
@ 3A, nege^cive ground: L9.5" x W9" x H Z.5"; weight (2.3 kg)
5.7 lbs.; mobile mounting bracket.

SERIOUS DEALER LISTS AVAILABLE

tvLt::.aL CO-

NCG

^3li

1275 N. GROVE ST.
ANAHErM, CALIF. 92806 (714) 630-4541
NOTE: Price, specifications subject to change wtthout notice
tfind obligation,

WORK THE U.H.F. BANDS

Add a trans verier or converter to your existing 10m, 6m or 2m equipments.
ChtKJSe from the largest selection of modules available for DX. OSCAR,
EME, ATV.
TRANSVERTERS MMT 50-144 $234.95

MMT 144^28 $219.95
MMT 432-28 (S) $319.95
MMT 439-ATV $379.95
MMT 1296^144 S399,95
^^^^ OTHER MODELS AVAILABLE

CONVERTERS

Choose from many models to suit your needs.
Examples: MMC 432-28, MMC 426/439— ATV

MMK 1296-144, MMC 12S0— ATV
Write for details and available options,

FILTERS

Prevent OSCAR 8 Mode J desense
Use MMF200-7 $42.95
Stop receiver IMD birdies
U-.' PSF432 $59.95

ANTENNAS

420^50 MHz J -beams

48 eL 15.7 dBd $75.75

88 eL 18.5 dBd S105.50

1250^1300 MHz loop yagi 1296-LY S49.75

Send 36C stamps for full details of all our VHF/UHF items

Pre-seleaor filters Transverters

Low-pass filters Converters ^VSA ^

Varactor triplers ^ Antennas

Pre-ampiifiers W ^Trystal Filters

Spectrum iTtteriiatlaiial, Inc.
Post Office Boi 1084S
Concard, Mass, 01742 USA

70/MBM 48

masi^t crvarge

t^436

FAST
SCAN

A modular approach. . Jor your own custom-designed ATV

system Here's how TXAS^4ATV£XCITER^M0DULAT0R.te»ppd

Tfiim wIrwJ and lasted madufe la deaiorad to drivi- th*
Motorola MHW-ZIO module in me PA5 113 wall llnsar
iff\\t. Tn* crvalal m (Ke 100 mHz reflion k&eps har-
mor^iCi C^ijI 4! luvQ melftra fqi talk bkcih. The v^d«Q
(TMsdiila^oF is lull fl mHjt lor compuJ&r gyaptiica and col-
or. Requires l3.-&¥-dic r^ ^ 70 ma. Tuned wllh ittal on
439. M. 4S4.0, or 42e.2^ rnHj, Provision fgr ayrtc ftn-

pandirtg Freq. a^^aiiabie.

PAS 10 WATT ATV POWER MODULE %S9 ppd

Th9 PAS will pul OUT 10 wans f^MS pQw^r an tne sync
t^ps wh*n df<v#n with BO mw fty line TXA5 e.<cller. SO
ohms in and oul, ptus bandw>icF(h lor the wtioie band
wkth good lln«ar'it¥ fot CQ^of and sound. Requir<&s \3,3
vd€ rflgulaled @' 3 amps.

FMA5 AUDIO SU&CARfllER GENERATOR

w -r ■ !■-■■■ ■ ■■■■■■4 ■ m * t m ^)9^ if-ll pihfeAHiBBia-HBB ^&9 UQU

Puis audio on wiih /our camera video (usi as iac^^}-
caei TV iJo^sai <.& mHz, Pci&out tip to 1 w p^p 10 dnve
ih* TXAS at VM'2. 3, or 4 rrodulalors. nequii>e$ l^w Z
itiht (ISO 10 6W otiimsj. and + 12 Id IB vdc ® 25 ma.
Works with any xmlr wtlh b mHz vid^^ baniJwicl^lh,

TVC-2 ATV DOWNCONVERTER. . . . «S5 ppd

&tri]>iirte MRFftOl j1.7 db H^} pr*6m:p and (foubie bai'
anted mtjcer module digs ouE Iheweil^ criesbur t«si£.iis
mlBirmocJs and o-verJoad. C<?Tvn&ctsbel*sen uhf anlen-
na and TV aet 1un«d lo ch^nnei 2 pr 3 vnficap' tun^s-
4^0 to 450 mHz. Requires + 12 to TS vdc ® 20 ma.
Super ssnailive TVC'2L *i(h NE64535 o^eamp^.9d±) NF}
Stage . . SE9 pp<l

*TXAS, PA&, FMA5 and TVC Baslo Module Pkg-

Call tif wrtle tor our complete Det qf specificatjons, statiion set-up dlagrams^, and

optional accessories v^tiich include antennas, modulators, detectors, test

generators, cameras, etc. WE ARE A FULL-LINE SUPPLIER OF ALL TOUR ATV

NEEDS.

TERMS: VISA or MASTER CARD by tefephone or mail, or check or money order by

mail. Afl prices are delivered in USA. Allow three weeks after order tor delivery.

(213) 44? 4665 Charge card orders only

P.C, ELECTRONICS 2522 Paxson lan©,
Tom weORG Maryann WB6YSS Arcadia, California 91006

100 73 Magazine • February, 1982

Two Keys TO Perfect code. . .

^^ssmmua^m^

Save over $14.00 with complete CW package for H-8/H-89-

Package includes CODEM, Interconnect Cable, Power Supply, CW39
Software, compfete documentation and shipping.

CWa9P $249.95

COMMDSOFT

^59

665 Maybell Avenue • Palo Alto, CA 94306 • (415) 493-2184

Write for free catatog

Ca I Ef 0 rn la res tdB n t a ad d ap p I i dab le sal e ^ tax . Master Card and V ISA ace epted

The CODEM: a universal CW interface for
your personal computer

*1 24.95

Here is an easy way to get your Morse code software on

the air I The CODEM converts received CW audio to
RS232 or TTL signal levels and RS232 or TTL signal
levels to transmitter keymg. The CODEM doubles as a
code practice oscillator and CW regenerator A sharp
800 Hz bandpass filter, AM detector and low pass filter
are designed into the CODEM to provide outstanding
noise and QRM rejection. Requires a 9 VDC power supply.

vUUtrVI .>.« .riiTciiii #1^4.93

9 VDC PowerSupply 9,95

Shipping and IHandting , 5,00

CW89: a sophisticated split screen Morse
code transceiver and trainer program for
Heath computers.

99.95

Transmit and decode CW with your H-S/H-IS, HB9 or
2-89. This feature packed program incorporates 4-99
WPM operation, receive autotrack, a 1000 character pre^
type buffer, 10 user-definable messages, unique break-
in mode, on-screen status, disk I/O and hard copy and a
versatile code practice section. A comprehensive
manual and prompt card are included with CW89.
Requires HDOS, 32K RAM and hardware interface (such
as the CODEM).

CW89posfpa/d $99,95

CW89C H.8/H-89 Interconnect Cabie for CODEM 24.95

PLESSEY- AVANTEK- PLESSEY

PLESSEY fNTEGRATED CfRCUITS

SL1610 RF Amplifier
SL1611 RF AmpHfter
SL1612 AF Amplifier
SL1G13 Limiting Amp
SL1621 AGC Gen
5L1622 AF AmpVOG

It;

S.Ob

4.07
3-72

SL1623
SL1624
SL1625
SL1S26
SL1630
SL1631

AM Det/ACC Amp 6. IT SLH^a

MultimodG Det 6.17 SLl^til

AM Det/ACC Amp 4,07 SL1680

VOCAD/SJdetone 3.72 SL6600

AF Amp H.Mi SL6640

AF Amp 4.07 SL66S0

DoubFe Bal Mod
Receiver Mixer
Ktal Maint Ckt
IF Amp/Det

4-07 SLE690 L.P. IF 5, 93
(|,07 &L6700 L.P.AM \f5.m

5.45 speeto 200 mmo 5.22

6.78 SPB66S 1. 0 GlIO 54.24

FM Rcvr W/Amp 4.41
FM 'ti^vr W/O A 3.39

SP8680 600 MtIO 17.^0

AVANTEK GPD SERIES AMPLIFIERS (GPD 401 ,402,403) $25.00 EA.

^2 - U dB Gain 5-500 MH Z -
CIRCUIT BOARDS FOR GPD 400 SERIES AMPS $200 ea.

AMATEUR MICROWAVE DOWNCONVERTER

COMPLETE - ASSEMBLED - READY TO INSTALL - NOT A KIT

50+ dB SYSTEI^ CAIN
TUNES 2.1 Ghz* to 2.H Gh;.
PREAMPLIFIER 7^ dB GAIN @2.5 dB HF
OUTPUT TUNES TV CHANNELS 2 TO 6
OUTPUT IMPEDANCE 75 OR 300 OHMS
FULL YEAR WARRANTY
PERFORMANCE GUARANTEED OR
VOUR MONEY REFUNDED

SPECIAL $179.95

INCLUDING SHIPPING (U,P.SJ

VISA AND MASTERCARD ACCEPTED
WE STOCK WHAT WE ADVERTISE

- t

I ■ r - -

CALL (804) 489-2156
ELECTRONIC HOBBY INNOVATIONS

(^447

7510 GRANBV STREET SUITE 207 NORFOLK , VIRGINIA 23505

^Sse List of Advertisers on page 114

73 Magazine • February, 1982 101

.If s becoming very clear now. . .
Yoyr microcomputing life is going to be very

exciting. ., Money! I see mucli
money for you. Perhaps it is the
money you will gain when
Instant Software's new
business applications
guide your financial
endeavors. I see
travel . . . you will
Journey to distant
worlds in distant
times. You will build
kingdoms from des-
erts and armies
from slaves. Never
will you be bored,
one! Your
programming burdens will
lighten with new utilities-new
tools. I see color! Many
bright colors! I see new
packaging for all these trea-
sures . . .everything new!
And... yes, a tall, hand^
some stranger who will
guide you to these won*-
ders. It will be your In-
stant Software dealer—
a wise one indeed. All
awaits you — all is
yours for the asking.
Soon. . .very soon!"

THIS MANY DEALERS CANT BE WRONG.

THE COM'\|t£n 5HCHP OidlMn

CXMWUTEH T4LJL ANCMHI^ii

CfiP

ro* iox s^prfivisia

AOVAJKt fUDiOcPVS OEIU.inh Qtm viii«f
ACh^ADKCO COMPUTEfl PPOMJCtfr. emu *rm

d4J.TII0MlCS, Svi Jaw

COUPiiTIA PvM$. SunnyvM*
CflMnJTEn &TDflE SMfi tundra
COMPlilEI WDRLD, WBtirriliitlBF
DEPK^eSAH AFWllAltCf A lEOA^R WkiVMUlllf
DlUCNStCHUAuSanViAJUt KanQicpa

mmoM t«fua cuTB

ffnOKbM *iATuHAL roo«

MfT •woriT co¥pyriBi Tofti

□woPitilNrnES i=D1t LUflMNO. CM.1i«Drti>

PC COMPUTE K5. tl C^TitC

Q I COWPUT ERS, INC . lAWPIdihtt

tUC PHOfiuCt^ S^n Jm

l|AO>0iHA{^ ElCaton
HAOIDtnAClu PklMSpiiii^

■UV ■pUtvD iKS DEAl.£lfc **niui«

aitiM*tu t<]Hat ciMttH fawt

THf CC«JPiir Efl STCHW f*H^U HarKS
TWiratMI'EDGflChJ* C4]iii<t[^vc*
THf larrVyAAEfiTaPf HNinlingli^Mi B«Kr>
TW*. MfTWAflE STflRE, tol AngMM
^AftAtH APPie. !► T«g
VUf tfNEH piJ$lHEBa IVlTf ML Uit M[l»

»CAt£UL#tQI»«=lin

OmTDlCT SPCtKUHBIA

rut uMiMfljiM STOflt withingiepi. DC
PLOfliDA

ALL nYirfilffi GO, Whviai Odrdtt

Ahr MICQOCDMnJTinC£*n'Cn T»quw

cemmtwumk

aATiKUiHJifl''EO' M^I»nHr»»>
HAH MOUv SAkES &ir«.wt4
HUTHUrr tLECTFtONIL, CtNlEB. H
H4 COUPvT£niylATIDN, bhHRiurr^
HDfeV'l KORMEH. l^niAEatJ

ttaaaoui^ ltd . thvu

litUNTAC(3iymiTtHM*flT *1iiili
SAiLtl'SCQHJ'UltflSHOfl AuDi^r*
MLTA OAT* DtNAWiCS Tuchw

rif «imiG OBmQ eo wwf

EtiECtnOHiC Vf OALllfS. Bv*B

HiL Data BT&TfMS I4>>^ Falls

ILUHDIt

ALPINE COMPUrCA CEtrrER f*M^iQiti
ChICJ^GD MJ^IN NFWSiTAND. EMU!«IIMt
iX^VPBE;H£t#5l W[ MICRO Sl'STttti. CUKaffQ
€yD*rPUTEBJU*KtlCiN Eiw-uHi
€C»tfUtlimiD*t itscAimi

dAfcu t Assocum.

ft«P4J3irXllH

04 D ElCC mONK^. ApvMb
DIG^FAL TECHNCKOQV. LiJayana
FALLCREEEffi EUQrnONICS Pldr^Jmign
QAhC HUf K\titim\riifton
GAME P^ES^HVF Indianapalia
PnOFESBlOMAt UfCKKfiMPUnn
fOrrWAKE, WuWw
SMMTOi LAiAf {MUC9
Tl^l

t>«haaishm:h

B««11M«.

eC*TTEH

AtMTELlfl RADtQ |C3Ut*«iEHT VMtMt

COMMUNK:AThPN!l C^ENTiq. tKiTC«ln
OaSilB^NI'L WicKiii
MArCH CDMnjUh SeNTTER. AlhWWI
NliaH tEOHJiOLDOT. WiClut*

kfHTiifCiir

C$U iHK L«nAg|IM
^Wtr^ GOMPllTf «

tuiHfOOUPurnOtwCS Sanger

41AINE uicno 5rAT|U$ PNC Aubunt

M■C!-HAl«trcQvl^^^fF! c^HPjiihiv Airfnurn
IMAvuiNCi

co<iMiM cifN'TEn Liii^pi

SO^rwAFS ETC 'I^i«i3«"^k

«ou««i

Ttff GaMC SHOIP mWtACJV

mCHIfiAh

ALL iFDR: LEAHNIkTCi VV B'tOOmf^W

AtTEi^NATt SCLfHCi L»i4ino

Akr CLECTROtttCa. AnnArtwr

COMIC K9NG0OW. Owliod
OGMPUtth CCNTi n Os^Mri Cdy

ooHnrtea cONNfCinoii, Fanwr^^ mm*
CnmTjTtttMiniT rMr

f«Ht»l

L£AR7iilitG CEhTlPI UTD. AMI A4»
HAWSv-fiTEMa INC FUM
MlfrMlCHiaAhl MIHO'T' Qir^CiMyH
hiEMMA*! I10MMUNICAT»DNS. Ofir^d tUjHll
NIJMMAN CfMl^lE'REKCHANae Ann A|t^

Tnii.C[::MjNTr elec^pwihics a sou^b

WCATHERWAA EAuC» atMMrfi
WZUIDl A4SEM)L Lfelfi LVWI9
rf OJE TEACt^m I»«n«. n

Wl*lHf STiFA SOFTWARt yVhIti ftipr L«»
AiJHAL iMt mCA E*JTE:nPmiei. Uir^h^H
f"M CClMPJuTtRS awoAl^n Cw*ltt
IMIAIIWP*!

mfASuvC: H*flPprt
«»T»fA«€MHajK 4«C1W

&t.Cgll1l4l

Moont lOrTWAni p»iii*i»*

BOmMflt SHACK Oaiiofi

HOItTAAI'k.

COMPuTEf^iironE aielinm
THE COMthJIEA (nJlCE, K^Uktrili

A1>PU'n|| SOmAARE BflMli l>

OKEAT MACE Ntoeai' puct

LEZDTtE EtUkD

ccumrTEH ■toAt

vrsHirTm coMfUTEii cjcjf Tt*

CCWfRCIULrr A4«|<Mrll

P*Ul 5 Ty. f TTfnonf

PORrUHCWrH COUPUTEf) etN-TIH

Pwlimaifin

fWDIO IMACR A5&OC STOflt Mipn*

AAQIO Sma^^K. Cl^rafnan*

fliDtn piACtD in.'So&AUiD

SfUliOiyAJiit AM? HUMlL

■OCUlAArt tT ATiQMIP*^ 0&

CIIHnjTE««AAWA

ipqMnjTimMQfMJ] on^ wtStntLD. hhi*w«

CRCWLEVI. Wf^iitttayH 3.|«iiWi
l»VE"t HICmOMlCE. INC P»fln»ri|i«
tLlCtHQfflC WORtO Uintup

AtJllECTRDHiC WOflLD MAntiH
LjAtNfNCLCCTnomCS IMC amtttUt
WBAA DATA SrSTEtA5 «NC tAwitOR
JlimAll*MAK ASBOt tlDAt

: cn*
sonwutcm

A4^1^ Ei.ECtiv«:3 no «««*,

OOMnJilP Liuafl,

hiTCmEli MiStC C«*M<a

THOATAA E €ARR JCWELIPi Awn9gp«10Q
M^AHOJIiMEGVVt'ST Aie^^(taj«r(|ti«

NEW VDfln

Afll9T0> CRAFT {}|£TIMCTIVE HIMIAmHES

hfi^ Voir.

ABO «*OHt COMPUTER CftrTIR,

ft>JBl>>»Bpli«

QOMmURi

ctwiTuTtixnrj^ rr "ii^r itawTaM
EMHfrnwSTlMS ■wr* T^tf*
iftMiCJW)cJPWPiirtH s£ BvicEi. c«nj«

iFUTLjRI VISIONS CQHfljTtA I TORE Wftorila
iWCRONlTT 9nj(^\>,f\
MODERN TEA SHOPS, 5P>vlMr

VH CCMltMTER. WlppllWfl ^kllt
PNR C;i IAN AIR ENTCANjJlEi

I^Afllbvipti
rtWMTOftAESEARi:^^ Cak^Im

muiiAva EMuatf i£ii

At^AlH IVStfWS^ INC. EhftQit

ciNC^HNNAti i::;>aMi\irEn si'Oflt. Cinctmit

COMPy 1 ER 5toft£. Tciipjo
KjM^HjTtftLANO. ^qlgmiigi
COuPUtERLAND Uflvl^vl K^Qfill.

Wmmjtftuino. i«i>rni oiP!i»H(rt

QIWnj7E<nLANP, MM*t
JfHPm QCHinJTEII
I ENTUIPJISES

COUPvTfnampi

hifCnO' MINI COMPUT ER WDRLP. CCiiiinKKIt
fiVENTY FiflaTCfhTlint shop. dr-ciHiiiii
MANNA PLAY CincuWAM

0HLAHD4U

C43u»LiTEHSTOI*l (h(C trtH
COMPUTER «fOn|.D tinm

£vk.#l£ Q«A PWOPV-ElMlOiT

IT i
fTC.

CCWPUTEHLAAID O* ROmUWD

UHmJCnteRjCt-Jhiw*^

FELFCtWlMttfc

PtHHIfLVAHlA

ALLlCCf HOBBiCfi. PhilMMtfiMi
*Hrr,0 ELECtaOiflCfi. *'tHi*te^i
QELLfLECrnONlCS Ediiboro
tEiL £4.£€TA0MIC* OiPim
COIAPUTCMUND. OiVwyiiu
■OOMPUT^flUmO OF HAA^iSBi^jRG

AftE COUliLMlCATlOl

4f*FiA Assocwrn

fltVBfi ItoOO lAulOt HALEft I

(Ui^cbsnuMi TOT tMOP *i*> »
rf LfvciOH PHPrrt coupAMT »HC .

pumTD ntm

MkCRQ CDMPU ti'^ STORf. C4;ipit4 TirrHnl

RMDOE l34uAlffi

EDl04rlAL EI^TIPiDltiaES \^$- DEALEPt.

I^atlnf

iOUTR -C^MXIHA

OM**i ELE^'ftOi^lC* ChulBfl^

tfurfi otiPvTfw CEVTSt

TI14

AlJIllO MORK&. UiflMI

CO&EDATA iNC . Arnr^fUFi

f:OMPUrER CONCtPTK ■adiunO'^T

COMPUTER 'N THINQft Aultin

{U^MPUTEH PHOtil^AMMrNa ASSOC , L44tll«eA

COMPUTER *ClRT A\\\ns[otf

COMPUTF^SAlEt^BEmnCE FDrtMofth

COtAPUTEnLANDClP^IIMHGUSlIIOh HbuUM
CDHPim^ It O Nt^LL UH ,

i-TDOD

tUCSTVJTi

«liliR¥MAClhOlATIHi ittS DEAlEI%

MiCnQ COMPUTER CQ»<C£PTS. PlArto

?*H AMERICAN ELECrnONlCamS PiALLEPU,

n i CDLE'& ELECTNUNICS. San ArrldiriUi
HQr-fi Ca 1 ELECTHiShlCS Armiiui PlAi
IP J^QFTAAAE bA AnioniD
TOTAL C«AmTl.MtrOH[. liULin-iI^
rtACMALTE3l BCnUi ftiC He^^

UVJUI

I3UUJTV ffCHPfOtOO* imgi^mCmr

^vt!-Q CO 4H ocALf n

OQWPUTEH SOCUTtOHa

CJOMPUTER WVORHi IKM: HfriHAlimrii
FPUH£ OALLERV. HfHKhsn
MOWe CCXMPVTiiB CtNTIfl INC.
tfirgiflll B*Kh
LlTtLESOLUiefl AMiNnQn*
trS.r^MS MARKET iNOI AtaiFigfiMi

WAIMHtlTIQW

#lit«CAM HEilCAltfriLE DQW«NV Suttlli

C4^l

Jl ULE5

iOi»va.pwj«B|iiva

PtHUtiAL COUnjriRS ihC^iB4iA<*r

UNIVlRSItV VlLLAQil MUSK. S«riM
iJ^b ENTEAPfllftE h-"Klinit
WHf^ttRN MiCHDCCMPUriRCENTEfl.
rt*iM ii'-'j*iam
WE5tVlR9JMI4

C.OMPgtsn COWlPI M«iivn9csMi
COUffirTtA STORE. MiMPVlon
QMOVAUJpf EUECtlOK: STETEtIi,

ft BficmoMC SPfC3ALnEi

t^AiiTi3s cawpnirt*

umF Sal is fitini

WUCONWH

BVTE SHOP arHhFifild

BfTE Shop Mih«BuA«

.QOMWiTtPtwoRLj? Ketmon

COHPUTtA WOftLD &AA« tei
OOktfUf EHLM0 Hdi»#

c3ni«urE«i.AJia or fq? wf» vA4jlet

WtQMMQ

COMWTIP CONCEITS. C)**HI(iw*P

AUSTMLIA

C.ISA MicnocoMPunNo. &uin4^

□ E FOREST liiCKnVlARE. NhiiLtitaiUiiB. V«.

MUCD ooMmjtmip (XMTDEL

AULL COMRUfERSV5TE4tt VvtWHi IC
8IT^ I nrrti EMnmaulh N i
CE«t|UL OiafWBUTOflfl LTO, LHlllAt.
QfJVtHC

CCwPuCQPiNEn. JmiinvA. B C
CnM^I/MAFU 1*lt^i.«K QnlfllHJ
aWnjTF'' Bf 'I SwniB.OilA'iA
nOMnfrTt- r^JitcmT. umAKi Ckiupia
COU^/TfA inrti0WA.TlOI« Oftf

camj^EASMCPLTT)
goimrTciitio««j3^ "wtetikn^r bC

CH6ATWE OPMPLi'E^
QATA1BQ0IM.T^I>

BAUIfnCA CQWWT^IB LTQ IdnwiWn.

AltWil

IVQNS l.-CMie LT& , ipmijKwi. On\ma
MM^ftOUAUOtl. lurntna During
UtCflOtt^ACA. S«:khatDoti 5dU
MfCW IMACA. A^fnL BAbk

lUA »im^te:ib. mwimmia Onim

;-Ct htKtL *.J-9PB^ CMmm
Li e#*Ct. HACnMEA imm m

SATwocn^rii^si^TEia w

4iEsr MqmoCdAtPVTEJffi l<

rTALT

iFTS k BVTES MtJHt

FAANCI

eoiitVTiiipiu.Kmg
M<:ipa ^cautrfwtt. I
MCPtosvi^iMca.i

MUaCPAMl CHff ArMI'

ON^L aO«*HE. DtJtf-Hn

RAL MtCHOCOMPUTERS Th* HAQu*

NEW FEALAND

ViSCGuN' llECTHQMICS Piilni#mgR (mirth

HOmVAV

A.'SSOHLLrND V#d»rl0*ft

SENTEC^II JJf^Mmt

CALVrg COMRVTEPQ
TW BPfvwmt mOUK. I

.llpiF fi

YOUR NAME COULD

BE HERE, CALL:

1 800-258 5473

WHAT DO THEY KNOW THAT YOU DON'T?

Find out Fill out this coupon (or make a photocopy) and
mail it today. You'll receive a dealer pack, filled with details
on how you can join the ranks of the successful dealers

listed above— with Instant Software.

NAME:

ADDRESS;

CITY:

STATE:

.ZtPi

Instant Softwcire Inc

^A4S J

Peterborough, N.H. 03458 603924 7296 ^^^ y

iP^See List of Advertisers on page 114

73Magazme • February, 1982 103

ieny Dijak W9/D
215 Tareyton Dfive
IthacA NY 74B50

CW Interface

let your computer do the copying

It is one thing to obtain
software to decode
Morse code with your com-
puter, but it is quite another
to process the audio signal
delivered by your receiver
in such a way that the com-
puter can use it. This article
will describe one approach
to solving this hardware
problem and also describe
the construction and opera-
tion of an interface circuit
using these principles.

I will assume that you al-
ready have software for de-
coding Morse and will de-
scribe the needed hard-
ware. An example of such a
program was presented by
Thomas' in the December,
1977, issue of 73. For our
purpose, we will assume
that your software requires
a TTL signal that is logic
low during the key-down in-
tervals and logic high dur-
ing the key-up intervals.

Proper operation of your
decoding algorithm will re-
quire the presence of one
logic level during the key-
down interval and the op-
posite logic level for the
key-up state The computer
must see only one or the
other of these states at any

LIHlTEf^

♦-PCILE

BANDPASS

FILTEII

one time, and they must
change only when the state
of the desired signal
changes. State changes
should not be affected by
interfering signals or ran-
dom noise.

An extremefy simple cir-
cuit could successfully be
used to interface a com-
puter to a ham receiver if
the audio signal produced
by the receiver were perfect
(absolutely noise-free and
of constant level and fre-
quency), but the circuit
must be considerably more
elaborate if the computer is
to perform property with
the imperfect signals typi-
cal of ham-band operation.

Typical receiver output
during CW reception on to-
day's ham bands presents a
difficult problem when at-
tempting to decode the sig-
nal with a computer. Even if
the operator is using a se-
lective receiver (400-Hz
bandwidth) designed for
CW reception, several dif-
ferent signals usually will
be present in the audio- The
signal that the operator is
trying to copy probably will
be tuned for his preferred

pitch, while the others will
be present at other frequen-
cies- The desired signals
probably wilt be the strong-
est, but the others may be
fairly strong also.

In addition to these inter-
fering Morse signals, there
will be noise. In the signal
output that is available to
the computer interface cir-
cuit we will have, in gener-
al, voltage due to our one
desired signal and also con-
siderable voltage due to all
the other signals and noise
being processed by the re-
ceiver. In order to decode
the desired signal success-
fully, we must have a way
to detect the voltage due to
our desired signal while ig-
noring as best we can the
other signals and noise.

Desirable Interface
Qualities

We can summarize sev-
eral design objectives for
our receiver-computer in-
terface. First of all, it should
be (as always) small, inex-
pensive, and easy to con-
struct and operate. Second,
it should respond only to
one very narrow band of au-
dio frequencies, for maxi-

OtTECTOB

FiLl'tff

I .

SUCER

^•e TTL UUfPWT

THBESHOLO
SELECT

Fig. 7, interface block diagram,
104 73 Magazine • February, 1982

mum immunity to adjacent
signal interference and
noise. Third, the output
should be bistable and TTL-
compatible for proper inter-
pretation at the computer
input port; the output
should be either logic high
( + 3,5 to + 5 volts) or low (0
to +0.6 volts) and never in
between. Fourth, the deci-
sion threshold of the detec-
tor should be adjustable to
allow the interface to oper-
ate properly with both high-
and low-level audio so that
the operator is not forced to
operate a certain audio
gain setting which may not
always be convenient. And
fifth, the interface should
work while the speaker of
the receiver is operating, so
that the operator can hear
the code while it is being
decoded to allow detection
of computer errors (decod-
ing errors can be expected
under adverse reception
conditions).

Theory

Fig. 1 is a block diagram
of one approach to doing
the required processing of
the receiver audio. The first
stage is a limiter which pro*
duces a known signal level
at the beginning of the cir-
cuit; this allows the rest of
the device to be designed
optimally for this level. The
limiter is followed by a
4-pole active bandpass

AUDIO ^OK

IfiPUT ° ^

CAPACITOR VALUES fN ^F

o TTL OUTPLiT

F/g. 2. Interface schematic.

THRESHOLD

SELECT

(TTLt

filter. The filter is tuned to
950 Hz and has a design
bandwidth of 80 Hz. This fil-
ter works by amplifying the
signal about 16 times at its
center frequency and atten-
uating signals not within its
passband. This ensures that
the detector stage only sees
voltage due to the desired
signal. The detector itself is
merely a half-wave rectifier
(a diode), and it is followed
by a simple RC tow-pass
filter so that the output of
the filter follows the pulse
shape of the signal as close-
fy as possible. The output of
this stage will be maximum
when the signal is present
and minimum when there is
no signal present,

The slicer stage decides
whether there is a signal
present or not. It does this
by comparing a preset
threshold voltage to the
voltage it receives from the
detector and filter. When-
ever the received signal ex-
ceeds the preset threshold,
the slicer quickly switches
its output state from -10 V
to +10 V.

Under ideal conditions,
the output voltage at this
point in the circuit would
never exceed this preset
threshold when only noise
and interfering signals were
present. If the voltage ex-
ceeds the threshold only
when the desired signal is
indeed present, no errors
will be generated. If this is
not the case (and usually it
IS not), errors will be
generated whenever the
combined level of the inter-
ference and noise exceeds

the threshold. (The slicer
will change state.) As soon
as the voltage subsides, the
slicer will revert to the cor-
rect state. For optimum op-
eration of the overall
hardware/software system,
your decoding algorithm
should be designed to ig-
nore these spurious but
unavoidable brief state
changes due to noise.

Finally, the output buffer
converts the signal levels
produced by the slicer
(which are incompatible
with the computer input
gates) to correct TTL levels.

The Circuit

Fig- 2 shows the sche-
matic of one circuit that
meets the design objectives
outlined above. I know that
not many people build any-
thing exactly as it is de-
scribed in a magazine arti-
cle [neither do I), so I will
not only describe this cir-
cuit but will also give a lit-
tle of the thought behind
the design choices that I
made.

Diodes D1 and D2 form
the limiter, and these
should be silicon types to
give a limited signal of
about ±0.6-V peak at this
point. R1 is used to keep the
input impedance of this in-
terface high so that it may
be used across an existing
high-impedance output of
your receiver {the anti-VOX
output on a Drake R-4, for
instance), in parallel with
whatever you normally
connect to that output. So,
this circuit can simply be
added to your existing lay-

out with little effect. Also,
because the signal level is
limited to 0.6 V, only about
al-volt peak of audio signal
is required at the input to
this device. On my receiver,
the anti-VOX output puts
out more than enough volt-
age at moderate speaker
volume levels. Another ad-
vantage of permanently
connecting the interface to
a high-impedance point in
your receiver is that the
speaker and headphone
outputs can be used or dis-
abled without affecting the
connection to the interface.

Components R2 through
U2 make up the 4-pole ac-
tive bandpass filter. My first
prototype used only a sin-
gle-stage filter (2-po I e), but I
found that it was allowing
too much interference from
adjacent signals. I therefore
decided to go to a 4-pole
design, with the resultant
much steeper skirts to the
passband. The filter design
itself was arrived at with the
help of articles by Stark^
and Stewart^ in past issues
of 73, regarding active filter
design. Each stage of the
filter is designed for a Q of
10. The center frequency of
stage 1 is 975 Hz and that of
stage 2 is 930 Hz. This yields
a 3-d B passband of about
80 Hz and very steep skirts
and requires only 2 ICs.
(Strictly following the cri-
teria used by Stark would
have yielded filter stages
with higher Qs, but also
would have required a total
of 4 ICs and several more
resistors in the design. My
approach sacrifices some

skirt steepness but elim-
inates many components.
That was my choice,)

Each filter stage is de-
signed for a gain of 4.8 so
that at the overall filter cen-
ter frequency of 950 Hz the
complete filter has a gain of
about 16. With the 0.6-V
peak input, about 10-volts
peak output is developed at
the detector. If you would
like to try your own hand at
designing the filters (per-
haps you'd like to use ca-
pacitors you have in your
junk box or a different
center frequency), use the
procedures given in either
of the above two articles
but be careful to keep the

first resistor (R2) around
look or greater so that the
input is not loaded down.
R1 and R2 form a voltage
divider, and smaller values
of R2 will require more
drive voltage from your re-
ceiver for full limiting.

Diode D3 is the detector,
and R8, C5, and R9 form the
simple low-pass filter. The
filter components were ar-
rived at by experiment, the
goal being use of a physi-
cally small capacitor at C5
and optimum following of
the keyed signal pufse
shape at speeds up to about
30 wpm. These values meet
these criteria well.

U3 is the slicer, and the
resistor network RIO, R11,
and R12 with Q1 produce a
software-controllable vari-
able threshold. Using the in-
dicated resistor values,
when Q1 is not conducting,
the threshold at pin 2 of U3
will be about 1.8 volts.

73 Magazine • FebruaryJ982 105

* f#'

'^ 4i 4: ..Jh' 'K'<

'*:■:.« *

* ■» •

^ •• ■■*

¥. ^'

1 4 l^ f* f r^ M ( r I I f J ' i i I f M I * f ' I ■ * ' ' " * * ( ' * ^ ^ * ^ ^ 5

When Q1 is conducting, the
threshold will be lowered to
about 1=0 volt. Thus, by ty-
ing the input to R13 to one
bit of an output port, you
can control the slicer
threshold through software.
This could have been done
with a mechanical switch,
but I wanted to mount this
circuit deep within the bow-
els of my computer, con-
trolled only by my com-
mands via the keyboard.
This approach took a while
to design, but it requires
very little additional space
on the circuit board.

Under normal condi-
tions, one would use the
higher threshold for the
best performance. But
when you are operating
with a signal level that is
not strong enough for full
limiting and noise condi-
tions are favorable, you
can extend your operating
range by lowering the
threshold to about 1 volt.

The output of U3 is either
about +10 or —10 volts de-
pending upon the detector
output to U3. These levels
could not be applied safely
to the TTL input port of a
computer, so the buffer
stage, Q2, was added to
provide a signal that always
remains within the TTL op-
erating range of 0-5 V. The

Photo A. Interface prototype.

output of Q2 can be tied
directly to one bit of an in-
put port.

With this circuit, the idle,
or no Signal, state of the
output is logic high ( + 5 V).
When a signal is present,
the output drops to 0 V.

Construction

Photo A shows the proto-
type of this circuit in final
form. My next step will be
to reassemble it on a plug-in
vector board for mounting
directly inside my comput-
er. As you can see, it re-
quires a total area of about
2 by AVi inches on the
board. None of the compo-
nents dissipates an appre-
ciable heat, so it is safe to
mount them adjacent to
each other (but be careful
not to short any leads). The
wires visible in the upper-
right portion of the board
are for my temporary
power and computer con-
nections to the circuit.

All resistors used in the
circuit need be no larger
than Va Watt. I used what I
had in my junk box, so some
of the resistors in the photo
are Vi Watt. Capacitors CI
through C4 should be high-
quality polystyrene or
mylar^M (and not disc
ceramic) as pointed out by
Stark. Try to get values for

€l

R2, R4, R7 as close to those
listed as possible — al-
though the final adjust-
ments of R3 and R6 will
compensate for any varia-
tions from the optimum
values. The values for the
two trimpots, R3 and R6,
need be considered only
approximate, and the final
adjustment of these two
can be expected at about
mid-range if the indicated
values are used.

Diodes Dl and D2 must
be silicon types (small sig-
nal) and D3 can be either
silicon or germanium, C5
can be disc ceramic. Ql
and Q2 are any general pur-
pose silicon transistors
capable of operating with a
2-mA collector current and
a beta of at least 100 (type
2N3566 were used here).

As you can see from the
photo, it is not necessary to
etch a PC board. All three
tCs are type 741. Power sup-
ply voltages of +12, —12,
and +5 volts are required,
but these should be avail-
able readily in most com-
puters.

Alignment and Check-Out

The only alignment re-
quired is that of properly
tuning each filter stage. For
this, you will need some
type of known frequency

audio input. Apply an input
to the circuit at 975 Hz, at a
level of 1 volt or greater,
and adjust R3 for maximum
output at pin 6 of U1 .
Change the input frequency
to 930 Hz and adjust R6 for
maximum as measured at
pin 6 of U2. You then
should find that the 2-stage
filter has a center frequen-
cy of about 950 Hz and an
80-Hz passband. With an in-
put signal level sufficient
for full limiting, about 10
volts (peak) signal should
be available at the output
of U2. Under these same
conditions, the voltage at
TP-1 should be about 3
volts (dc). As a final check,
you can confirm that the
output of Q2 is + 5 V with
no signal applied and 0 V
when a 950-Hz signal is
present.

Operation

Once the above initial
alignment is completed, no
further adjustments need
be made. When operating
the interface, all one must
do is tune the desired CW
signal properly so that it
falls within the filter pass-
band and adjust the re-
ceiver's audio level to an
optimum value. These two
tasks, however, are not
quite as easy as they sound.

The easiest way to tune
your receiver for optimum
operation of the interface
requires an oscilloscope.
While there is another tech-
nique, it has some severe
limitations. 1 will first ^oyer
tuning with an oscilloscope,
and then the alternative if a
scope is not available,

Oscilloscope Method

For the moment, let us
assume that you have a
dual-trace oscilloscope at
your disposal for operation

of your receiver-computer
combination. Connect one
channel to TP-1 in the cir-
cuit and the other channel
to TP-2, Use dc coupling for
both. Use a vertical sen-
sitivity of 500 mV per divi-
sion for both channels and
a sweep speed of 10 ms per

106 73 Magazine • February J982

division. Adjust the base-
lines of both traces to exact-
ly the same point near the
bottom of the graticule. You
should then obtain a dispfay
similar to that shown in
Photo B when a properly
tuned signal is being re-
ceived.

In the example, both
traces have their zero base-
lines one division from the
bottom of the graticule and
the vertical and horizontal
settings are as recommend-
ed above. The trace visible
about one division above
the center of the graticule ts
the TP-2 threshold voltage
[about 1.8 VI The other
trace shows the leading
edge of a CW pulse that is
being received. This display
shows just about ideal re-
ception conditions and is
what you should strive for
in your tuning. At the base-
line of the signal trace, we
can see that there is almost
no noticeable noise be-
tween CW pulses. This
situation is rare but does
happen occasionally. (In-
deed, the photo was taken
during reception of a very
Strong off-the-air signal at
about 25 wpm J

The first step in tuning is
to tune the receiver until
the tone of the desired CW
signal is centered in the
filter passband, as evi-
denced by a maximum sig-
nal amplitude for the signal
pulse on the oscilloscope
display. This will take some
care, due to the narrowness
of the filter pass band. After
this condition has been
achieved, the next step is to
optimize the level of the
receiver audio which is be-
ing fed to the interface.
Making this choice op-
timally will require a little
experience on your part
(which will come with time],
but I can give you a few
hints.

Your primary
maximize the
noise ratio at
(which is what the TP-1 sig-
nal shows). This condition
will give you the minimum
error rate out of the slicer

goal is to
signal'to-
the stJcer

stage, and hence within the
decoding algorithm in the
computer. Since you have a
limiter in the first stage of
the interface, you will no-
tice that you can increase
the level of the desired sig-
nal only up to a point, be-
yond which it will no longer
increase.

You will notice also, how-
ever, that if you continue to
increase the drive level, the
amplitude of the noise and
interference evident be-
tween pulses will increase.
This is undesirable. There*
fore, you want a condition
where the signal gives the
greatest difference be-
tween the peak of the signal
and the peaks of the noise
and interference as viewed
on the scope. Next decide
whether the normal (high)
threshold voltage is best or
if the lower threshold
would be better. Ideally,
the threshold of the slicer
should be halfway between
the signal peak and the
noise peaks. Then, by moni-
toring the oscilloscope dis-
play, you can ensure that
the signal remains opti-
mally tuned even if your
receiver drifts a small
amount or if the noise and

Photo S, Osciltoscope display.

interference conditions
change.

When using this type of
display, it is convenient to
have the current slicer
threshold (TP-2) superim-
posed on the display with
one channel of the scope,
but it is not absolutely nec-
essary. If you have only one
single-channel scope, just
remember where you have
set your threshold, or use an
external voltmeter to moni-
tor it while you display the
TP-1 signal.

Alternate Tuning Method

As you probably have
guessed by now, without an
oscilloscope it would be
very difficult to adjust the
receiver for the optimum
conditions described
above. This does not mean
that you cannot tune it to
work fairly well most of the
time, however. A VTVM at-
tached to TP-1 also will give
an indication of when you
have reached maximum sig-
nal strength, but its fluctua-
tions with the signal will be
much more difficult to irv
terpret. You also will have
very little ability to judge
the noise conditions be-
tween the pulses, but, if you

are having a problem* you

can compensate for these
by doing a little trial and er-
ror with the detection
threshold and seeing which
one works better. You will
find that you must tune the
receiver slowly in order to
find the very narrow pass-
band of the fitter.

Summary

This circuit evolved over
several months of experi-
mentation and testing, and
i think it is a good compro-
mise between circuit com-
plexity and satisfactory per-
formance. I think you will
find, however, that while
the computer can do a very
good job of decoding well-
sent Morse code under
good reception conditions,
the machine is no match for
the human brain when it
comes to poorly-sent code
or very adverse noise or in-
terference conditions. ■

References

1. Thomas. William L, "Decode
Morse— With an 8080," 73, De-
cember, 1977.

2. Stark, Peter A., "Design An
Active RTTY Fiiter/' 73, Septem-
ber, 1977.

3. Stewart, Dr. John F., "At Last!
A Use For Your Computer/' 73,
April. 1978.

73MagBime • February, 1982 107

Before you buy
that won't fill your

take a look at

Our General Ledger Package is what we

believe to be the best on the market ... but

don't take our word for it — you make the
decision!

Our General Ledger System Offers:

A iea'digit alpha^nuineric account code that accom'
modates the most sophisticated structure of accounts with ease.

It can serve sra^H business or, equaity well, larger companies
TieeJing to control several departments, cost centres, sub-
sidiaries^ branches* or various currency accounts and tax divi-
sions.

A frcC'forniat code. With no limitations on the use of the
account code, you can organize your structure of accounts to suit
your company's individual requirements exactly. You can have
as many groupings or secdons in the structure of accounts as you
need. And the number of accounts is governed only by the
physical storage capacity of the computet.

if you set up a suitable library of accounts, there are %irtually
no limits to the ledger s ske.

Flexible processing capability* and budget control. The
system wiU process accounts for 12 or 13 periods per annum.

It will maintain budgets in whole monetary units.

Comparisons for management decision purpose are readily
available for 12 or 13 period processing.

Automatic accrual convenience* The system automatical'
ly reverses accrual entries made in the previous period* This
simplifies adjusting accounts and improves control.

Simple data throughput. The facility of next-period pro-
cessing lets you enter next-period transactions before the present
period closes. Tills raises data throughput and allows ad*
justments to be made in the current period-
Simple seaAonal comparisonfl* The system, can maintain
details of activities period by period so that comparisons of this
year/last year^ for example, are quite scraighribra'ard.

Account Jtle inquiries on all accounts. You can probe
where and when you want. TTie system will display current and
historic budget detaiis» current and prior-period movemenCt
year-tend ate balances^ all on a single screen display or In a print'
out.

108 73 Magazine • February, 1982

Transaction file information facility. With over 60 selec-
tion options at your disposal, this is a very powerful enquiry
feature* Again, the irrformation can be displayed or printed.

Physical audit trails of all new% revised and amended ac^
counts are produced automatically, also audit trails of all transac-
tions! detailing account and reference numbers, type of transac-
tion, description, date, and batch*

A batchir:ig facility. There is a built-in technique for con-
trolling input so that all transactions can be batched.

Optimum management control This system can hold up
to 99 separate report riles, each containing up to 9 sub repons.
They can draw upon all data on the master files and can be
chang^ or modified as and when you wish.

Typically, standard reports such as trial balances are pre-
programmed. But profit and loss statements, cost centre activity,
income statements, representative reports, balance sheets and
the like can be set out as you want them.

The tmplkadons of this for management decision-making are
obvious.

Balancing controls. Sophisticated validation techniques en-
sure the integrity of input data.

Limitless flexibility. Standard ledger accounting is only the
start. Depending on how the structure of accounts is de^gnedj
the system can undertake project accounting, job/proJect
costing J sales analysis, contract ledger accounting, incomplete
record accounting, etc.

Growth capacity* Not every user will need all these fimc-
tions from the outset. But most features are potentially ap-
plicable to most businesses. With such capacities inherent in the
system right from the start, you can avoid complexities later.

business needs,
software that will!

Extended Software Maintenance Agreement. This
agieement will enable you to receive maintenance service
as will as enhanced versions of your package.
Technical Support Hot Line. Should you encounter
any problems during operation which are not covered in
the manual, you can contact our Technical Service
Department,

To Order:
Call Toll Free

1-800-258-5473

or use the order form below

AN ADDED EXTRA:
UTILITY FEATURES

Disk Formatting — allowing you to format new disks with-
out getting into the operating system*

Disk Swapping — allows the user to remove and exchange
disks without causing damage to data.

Disk Labeling— enables the user to create labels to put on
the disk which contains information identifying a disk in any
drive.

Disk Backup— allows the operator to make copies of his dat3
and program disks with case.

Disk Initialize — allows the newly-formatted disk to be
organized to run on our system*

File Move— enables you to move the account, transaction
and report files to user specified disk^.

FOR A

DEMONSTRATION,

SEE YOUR LOCAL

INSTANT SOFTWARE DEALER

D Please send me more information on your

General Ledger package,
n Enclosed is $699.00 + $5.00 shipping for my

General Ledger package.

D CHECK D MC D VISA
Card No. .

Exp-.

Signature

Please send me information
on your: D Accounts Payable

D Accounts Receivable

n Payroll

Name

Co. Name

Street

City

State.

2ip.

Inslant Software

Peterborough, N.H, 03458 USA

A Subsidiary of Wayne Green Inc.

Rt. 101 W, Dept. 16
Peterborougti, N.H. 03458

73 Magazine • February, 1982 109

t^A

NEW from

THE

NEW

WEATHER

SATELLITE

HANDBOOK

BY DR. RALPH E. TAGGART

Here is the completely updated and revised edition of the best-
selling W6ath«r SateUfte Handbook— containing all the infor-
mation on the most sophisticated and effective spacecraft
nowlnofblt.Dr.Taggart has wriuen this book to serve both the
experienced amateur satellite enthusiast and the newcomer.
The book is an Introduction to sateiUte watching, providing all
the information required to construct a complete and highly ef-
fective ground station. Not just ideas, but solid hardware de-
signs and ail the Instructions necessary to operate the equip^
ment are Included. For the thousands of experimenters who
are operating stations, the book details all procedures necea-
sary to modify their equipment for the new series of space-
craft. Amateur weather satelltte activity represents a unique
blend of interests encompassing electronics, meteorology
and astronautics. Join the privileged few in watching the spec-
tacle of eartli as seen from space on your own monilofing
equipment. Order 8K7aa3 $8*95

SAVE $2.95

WEATHER SATELLITE
HANDBOOK {first edition)

By Dr Ralph E. Taggart WB8DQT, Valuable information in this
first edition /s not included in Dr. Taggari's just published
book, Th9 New Weather Satellite Handbook (see above).
Chapters such as "How to 8uird an Electric Timer for Satellite
Tracking" and "Buiiding an Automatic Control for the SaieiJite
Receiving Station" will no longer be available when this edi-
tion is out of print. This is a good entry level text for those
discover mg the exciting new use of weather satellites. Regular
price: $4.95 SPECIAL PACKAGE PRICE-BOTH BOOKS FOR
ONLY S10 J5, SAVE I2J5[ (This offer available only while sup-
plies last.} Order WS7300 and receive both editions of tne
Weather Satellite Handbook for only SI 0.95 (plus $1.00 shipp*
ing and handling charge).

*Us# lh« order card in this magazine of Wmnlte your ofder on a sepa^ aie piece of paper
ajicJ mail ro: 73 Radio Bookshop • Potsrbofough NH 03458, Be sure to include check or
^l*ii?^ ^^^'^ ^'^ intpfm*tfon. Add 11 50 first book. JI.OO each additional bCMSk
»T0 00 per Doo* forenQn airmail Noie: Prices subject 1p ctiange on books not put>iished
by 73 Magazine Oyest^on* fegaiding your order? Ptease write to Custorner Service a)
the above address, PJease aftow 4^ weeks for deliwofv. Ho CO.D. orders acceoted far
Toll FmeordtringciJ 11 ^800^258-5473. *^i«j. ui

K^'i

N^\;i

* ^

1,1

JL^

MkKE
MONEY. . .
$ELL
MAGAZINE

Selling 73 Magazine, the ham radio
magazine that offers quality and
quantity, brings the ham into your
store. Once through the door you
can sell him anything.

Our dealers are telling us that *73"
outsells them all. . . so call today
and join the dealers who make
money with 73 Magazine.

For information on selling 73
Magazine call 800-25Q-5473 and
speak with Ginnie Boudrieau, our
Bulk Sales Manager. Or write to
her at:

MAGAZINE

80 Pine Street
Peterborough NH 03458

110 73Mag3Zfne • February J902

FOR THE NOVICE

Mw »^ tfOVlCE

NEW, UPDATED

EDITIONS OP OUR

PAMOUS NOVICE LICENSE

STUDY GUIDE AND
NOVICE STUDY TAPES

• NOVICE STUOY GUtDE— SG7367— by nmofhy M Daniel NSFIK. Here \s lh« most up lo da!e nov^ct
guide available H is oorrrp^e v^tti Information aboul learning Morse Code, has the latest FCC
airtateur ragulati^ons and tNe current FCC applicaltc^ni rorrns. mis guide fS not a quesliori/ansiAfier
memanzatiOTk ^^Oyrse but rair^er it emphasises The practical s^deof geitirH] a ham license and pii£t»ng a
s^atron on iha air. it re^lecls wfint \\m FCC expects a Novic^e lo know witfwut page after page of dull
theory. Tho mosl Current informal ton all 1 1 availabie at last year's pnoe. (4.35

• NOVICE STUDY TAPES— CT7300— If you aie |u^ idling started In ham tm^, yoult fir>d tl
tapes indispensa&ie! This up^o-thfrminute revision of irte 73 Sludy Course istheperrecl M^y to lesrn
ewfythinft you r>aQd to brMze tmoggti \h& Novicit written exam. Theory, FCC regulattona and
Operating sMlfs are aH covered^ and you'll be amazed at how fast you aearn us^no these tapos!

OnoelrM^teSt i% f?^ind you, the^e tap^ will go hght on boing useful, beca u set ney are packed with
tri6 Eatdst In Format ion on selling up your own ham station, and getting on the air.

Thousands of people have dt^covered how easy learning from cassette can t^e^ofder rKiw and
ent^r the fa&einalino world of ham fadJoJ— Set of :j— $16.96. *

Scientists have proven that v^u learn taster by listening than by reading because you can ptay a cas^
sette lapB over and over in youf spare time— even v*/hlTe you're drivingl You get more and more Irilo
each t4me you hear It. You can'l progress wilhoul solid fijndamentaLs.Tnea6 three hour-long 1 apes give
you aJltha bafiica you'll need to pass the f^oviice exam easily. You It have an undersiaoding ol the ba-
sics which wi^l be invaiuable to you for the rest of your life! Can you a I lord to take your Novice exam
witfKHjt lirsi listwlng to these tapes?

SPECIAL OFFER! Both NoTlce Ue«aB« Stud^ Guide and If ovice Studf
Tapes S 19.95. Order NP7300.

^f\ General License Study Guide

OHNERAL LICENSE STUDY GUlDE-by Timothy M.
Daniel MBRK, ThJs Ls the complete guide to Ihe General
License. Learning rather than memorising Js the
secret. This Is not a quasiion-and-answer guide that
will leather dust when ihe FCC issues a new test. Jn^
stead, this book will be a helpful reference, useful long
after a ham upgrades to QeneraE. includes up-to-date
FCC rules and an app^llcalion form. Order yours today
and talk to the world. SGT358 $6.95

# ADVANCED CLASS LICENSE STUDY aUIDE—
SGlOfll — Ready to upgrade your Hcenae? To prevent
retahing the FCC theory exam^ you need the 73 Ad vane
ed theory guide. S5B, antenna theory, transmitters, and
elect ronfc^s measuring techniques are covered in detail
in this easy-to-fotlow study guide. Special modes and
techniques. su*jh as RTTY, are also treaied. An engineer.
\n^ degr^ \^ not necessary to master the Advanced
thiofv— try thjs booh before visiting the examiner's of-
fice! 9&.9&.* IPub^ished by TAB Booka previous to reoent
changes in FCC exam material.^

FOR YOUR HAMSHACK

• OSL CARDS— ?3 turns out a fantastic series of QSL
carda al about half the cost of having them done eise-
where because they are run as a fill in between printing
books and other Items In Ihe 73 Print Shop. 250 Style
W— QWD250— for $B 95'; 500 Style W— OW0500— for
$13.95*; 250 Style X— OX0250-for 18.95'; 5O0 Style
X^QX0500: 250 Style Y— QY0250— for t8.95*; 500
Style Y— QV0500-ior $13.95," Allow 6-l£ wks, for
deffvery.

• LIBRARY SHELF BOXES— These sturdy white, cor-
ruga ted. dirl^e^sistant boxes each hold a fultyearof 73,
Kmb&ud Mfcrocomptttffig or SB Microcomputing. With
vouf order, request seU-stickrrvg labels tof any of the
follow ing. 72. Kiiob&ud Micfocomputing^ W Mtcrocont-
P0ing. CO, QST, Ham Radio, Pers<tnAt Computfng,
Radio Electronics, Inmrfsce Age, and Byte. Order 1 —
BXIOOO— for S2.00*: order 2 -7-8X2002 -for |1.50
each'; order S or more— BX 1002— for S 1.25 each*.

Style Y

Style W

Style X

MAGAZINE

• Preserve and protect your collection for a lifetime!
Ort^tr these hanc^some red binders with gold lettering,
$7 50 for 1. 3 for S21.75, 6 for $42 00. (Postpaid v/ithin
USA. please add $2.50 per order outside USA.) Check or
money orders oniy, no phone or COO. orders, 73
B Incurs. P.O. Box 5120. Philadelphlm. PA lit 41.
*fiOtE — Abo«« ftddrcH for BlAdera onJj.

CODE TAPES

ANY FOUR TAPES
FOR $15,951
$4.95 EACH

"OENEStS"

5 WPW— CT7305— Thm is ttw beginning tape for people
who do not know the code at all. it takes Ihem throuot)
the 2B letters, 10 numbers and necessary punctualkKi,
comptete with practice every step ol the way usl^ng the
newest blitz teaching techniques. It Is almost mirac-
ulousl In one hour many people— including kids of ton —
are able to master the code. The ease of liMmtng gJves
confidence to beginners who might otherwise drop out

"THE STICKLER''

e+ WPM— CT7306— This Is the practice tape for the
Novice and Tech ntc Ian licenses, it is made up of one
solid hour of code, sent at thte official FCC standard (no
other tape we've hea/d uses tr>ese standards, so many
people flunk tf>e cod« whrni they are soddenly— under
prfr&sure^facect with ehmctsrs sent at 13 wpm and
»p»ced forSvppm). This tape is r>ot memonzoljle, unlike
the zany 5 wpm tape, since tfie c^xja oroups are sfitirely
nfidom ct>^racters aenl in groups of fiveu

13 +

■SACK BflEAKER"
WPM— CT7313— Code groups mln^ tt a brisk 14

per so you wiiT be at ease when you flit down fn front of the
9tdely^ed government inspector and r>e starts ser>dl rig
you plain language at oniy 13 per. You need this extra
margin to overcome the panic which Is universe t in the
test all u at tons. Wh^n you've spent your money and time
to lake the test, you'll thank heaven you had this back-
breaking tape.

■^OURAQEQUS"

30+ WPM — CT7320— Code is what gets you wtien you
go for tfie Extra dasa license, it is so embarrassing to
panic out just because you dkfn't prepa/e yourself witfi
this tape. Though this is only one word faster, the code
groups are so dttf icuil thai yoa'il aJmost faiJ asleep copy*
fr^ the FCC stuff by oom(»rl9oa Users rvport ttiat thsp
cert't believe how easy 20 per really is wtth this fantastk;
OfMi hour tape.

"OUTRAGEOUS"
25+ WPM— CT7325— This is the tape for thai small
group of overach ie vi ng hams who woul d n 't be cont a nt to
almpty satisfy the code requiremenie of the EMra Class
ilcense. It's the toughest tape weVe got and we keep a
permanent file of hams who tiave mastered it. Let us
know when you're up to speed ar»d we'll inscribe your
name In 73's CW "Hall of Fame."

SSTV TAPE

• SLOW SCAN TELEVISION TAPE-CT7350— PrtZB^

winnir>g prog rams from th* 73 SSTV conteat. Excellent
for Oomo! S5.96.'

BACK ISSUES

«6ACK ISSUES— Complete your collection; manv are
prime collect at>les now, classics in the field! A full col-
lection is an invaluable compendium of radio and elec^
tronics knowledgel

STDOOO — ^Smgie Pack issue t>elore July 1980. - - .
ST0S50 — Single bacit issue July 1960 on,...*...
STD500 — Syouf choice

Add $1.00 pef m^agazine tor shipping,

STltXKJ — 10 your cfioice

ST25O0— 25 our choice .
ST2501— 25 your ct\oice *

Add S7.ao per ordef for alitppjno.

..$3.00

..$a75

I W » « #• 4 I

' « * P 4 •' I

.##»! #■.■#«# ^

.$14.00
.S1Z00
.$25,00

• FREE BACK ISSUE CATALOGS are yours tor the ask-
ing. . . Specify 73 Magaitne. and/or Kilobaud Mlcfocom-
puifng, bacic issue catalog when you send your name
and address to us on s postcard.

BINDERS

"Use the ord^r card in this msf^azine or itemize your order on a separate piece of paper and mall to: 73 Radio Booiltshop *
Petertjorough NH 03458. Be sure to include check or detailed credit card information. No C.O.O- orders accepted. All orders
add $1 50 handling fir^t booK^ $1.00 each additional book, S10.Q0 per btx^ foreign ikkmaiL Pfease allow 4-6 wee>(s for
delivery Questions re9ardir^ your order? Reas« wnietoCiistonierServrceat trie atx^ivsiaddress. (Prices subject to change
on t>ook$ not published by 73 Magazine.|

FOR TOLL FREE ORDERING CALL 1-800-258-5473

THE 73 TECHNICAL LIBRARY

_j\rt.."i»».i*-joi-

BEHIND THE DIAL— by Bob Grove. Get more fun out of
shortwave liSitenlmg with this Intoresting guide Ko
rscehvers, antennas, frequeo^ie^i and interference^
$4.95/ BK7307 "

THE CHALLENQE OF 180— ts the newesi book In the 73
technical library, dedicated to i60-m$ter operating. SI
Dunn provides all necessary infornnatfon to get started
on this unique band. TUB all-lmportanl antenna and
ground systems are described fn detail Tt^e Introduction
contains fnteresting photos of Stew Perry's (the King of
160J shack. This reference Is a must for new and ex-
perienced 'Top Band" operators. Pnce: $4,95/ BK7309

SSB. . .THE MtSUNDERSTOOO MODi-by James 8.
WJIson. Single Stdebar>d Transmission. . thousands of
us use It every day, yet it remains one of the least
understood facets of amateur radio. J. B, Wilson
presents several methods of sideband generation, am^
ply Illustrated with charts and schematics, which vviil
enable the ambitious reader to construct his own side-
band generator. A must for the technically-serious hem.
$5.50.^ BKZaSI

PfiOPAOATIOh* WlZARD^S HANDBOOK— fey J. H,
Nelson. When sunspots rjddled the woridwfde com-
munications networks of the 134Qs, John Henry Nelson
lool^ed to the planets for an answer. The resuit was a
theory of propagation forecasting based upon in-
terplanetary alignment that made the author the most
rehable forecaster in America today. The book provides
an enilghtened took at communications past, present,
and future, as weH as teacfilng the art of propagation
forecasting. 16.95.' BK7302

• TOOLS & TECHNIQUES FOR ELECTRONICS—
BK7348'— by A, A. Wicks is an easy-to-understand book
written tor the beginning kit bulider as well as the ex-
perienced hobbyist. U has numerous pictitres and
descriptions of tne safe and correct ways to use basic
and specialized toots for electronic projects as well as
specialised rrtetal working tools and the chemical aids
which are used in repair shops. $4.^.*

WORLD PRESS SERVIQi FREQUENCIES-by
Thomas Harrington. Can't wait to hear the evening
news, or are you wondering about the news that you
aren'f hearing? Receive by Radio Teletype (RTTY} aft
the worid news and financial happenings from the
world cepitois on a 24 hour aday basis. This bookgives
you the frequencies and times of broadcast of such
news services as AP, UPI, Reuters, TASS, VOA and
London Press. Also Included is an introduction to
RTTY with information on equipment, antennas, abbre-
viations— everything you need to get started in RTTY.
S5,95*BK1202

NE^^

FOR
THE

CONTE

THE CONTEST COOKBOOK— reveals the secrets of the
contest winners {domestic, DX, and specialty con lests),
complete with photos and diagrams of equipment used
by the top scorers. Find out how to make 1 50 contacts in
one hour, $5.95." BK7308

THE NEW WEATHER SATELLITE HANDBOOK- by
Dr. Ralph E. Taggart WBeOQT Here is the completeiy
updated and revised edition containing all the informa-
tlon on the most sophisticated and effective
spacecraft now In orbit, this book serves botb the ex-
perienced amateur satellite enthusiast and the new-
comer, It Is an Introduction to satellite watching, pro-
viding all the Information required to construct a com-
plete and highly effective ground station. Solid hard-
ware designs end all the instructions necessary to op-
erate the equipment are included. For experimenters
who are operating stations, the book details all proce-
dures necessary to modify equipment for the new ser-
ies of spacecraft. Amateur weather satellite activity
represents a unique blend of Interests encompassing
electronics, meteorology and astronautics. Join the
privileged few in watching the spectacle of earth as
seen from space on your own monitoring equipment.
Se.95." aK7363

INTERFERENCE HANDBOOK— by William R. Nelson,
WA6EQG— This timely handbook covers every type of

RFI problem and gives you the solutions based on

Kractlcail experience. Covers Interference toTV, radio,
i-fl, telephone, radio amateur, commercial and CB
equipment Power line interference Is covered in depth
—how to locate itr cure It, work with the public, safety
precautions, how to train RF/I investigators. Written by
an RF] expert with 33 years of eKperlence, this profuse-
ly illustrated book is packed with practical easy-to-
understand Information. aKl23l3 $6.95

IC OP-AMP COOKBOOK— by Walter G, Jung. Covers
not only the basic theory of the IC op amp In great
detail, but also Includes over 250 practical circuit ap-
plications, liberally iiiustrated. 592 pages, SVi xBV?,
softbound. $14.95." aK102a

OWNER REPAIR OF RADIO EOUIPMENT-by Frank
Glass K6RQ Here's a book that will teach you an ap-
proach to troubleshooting without a sh@ck full of test
equipment. Written In a narrative, non-mathematical
style, it will encourage you to successfuily fix your own
rig problems BO to 90% of the time. Even if you don't
want to fix, you can learn a lot about how things work
and fail. Add to your iJbrary and personal expertise.
$7.95/ SK7310

HANDBOOKS

FOR THE
HAMSHACK

THE TEN METER FM HANDBOOK- by Bob Hell K9Eia
This handbook has been pubilshed to help the ten meter
enthusiast learn mora about the many methods of con-
versions and iricKs that are used to make existing units
work better. Join the great "tlnkerers" of the worldon ten
FM and enioy the fantastic amount of fun in communi-
cating with amateur stations worldwide on ten meter
FM. *i.95.* SK1190

THE PRACTICAL HANDBOOK OF AMATEUR RADIO FM
REPEATERS- by Bill Pasternak WA6ITF {author of 73
r^agazines monthly column 'Looking West'') This is the
bOOK for tiie VHF^UHF FMer, compiled from material
submitted by over a hundred Individuals, clubs,
organizations and equipment manufacturers. A "must
have" for your ham shack shelf. SUBB* BK1 185

The 7$

Test Equipment
Library

VOL, I COMPONENT TESTERS— How to build tran-
sistor testers (8j, diode testers f3)p IC testers [3),
voltmeters and vTVMs {91, ohmmeters {8 different
kinds), inductance |3K capacity {9), G measurement,
crystal checking {6), temperature (2), aural meters for
the blind (3), and ali sorts of miscellaneous data on
meters. . .using them, making them mors versatile^
making standards. Invaluable book. $4.95.* LB7359

VOL II AUDfO FREQUENCY TESTERS- Jam-packed
with ail kinds of audio frequency test equip ment. If
you're into SSB, RTTY, SSTV, etctnis book is a must for
you . . .a good book for hi-fi addicts and experimenters,
tool $4.95,* LB7360

VOL. Ill RADIO FREQUENCY TESTERS— Radio frequen-
cy waves, the common denominator of amateur radio.
Such items as swr, antenna impedance^ tine impedance,
rf output, and fieid strengtii; detailed Instructions on
testing these Items Includes sections on signal generat-
ors, crystal calibrators, grid-dip oscillators, noise gen er
ators, dummy loads, and much more. $4.^." LB7361

VOL. IV IC TEST EQUIPMENT-Become a
troubleshooting wizard! in this fourth volume of the 73
TEST EQUIPMENT LIBRARY are 42 home construction
projects for building test equipment to work with your
fiam station and In servicing digital equipment. In-
cludes a cumulative Index for all four volumes for the
73 TEST EQUIPMENT LIBRARY. $4.95/ L873fi2

RF AND DIGITAL TEST EQUIPMENT YOU CAN
BU ILO— BK1044— Rf burst, function, square wave gen-
eratorsn variable length pulse generators — 100 kHz
marker,, l-f and rf sweep generators, audio osc, afi'rf sig-
nal injector. 146 MHz synthesizer, digital readouts for
counters^ several counters, prescaler^ microwave
meter, etc. 252 pages. $5.95,' BK1044

"Use the order card In this magazine or itemi2e your order on a separate piece of paper and mall to: 73 Radio Bookshop •
Peterborough NH 0345&. Be sure to include cheek or detailed credit card information. No C.O.D. orders accepted. All orders
add J1.S0 handling first book. $1.00 ^acU additional book, $10.00 per book foreign airmail, Please allow 4 6 weeks for
de 1 1 very . Q u est i o n s reg ard t n g your order? P lease w ri te to Customer Ser vi c e at t h a above ad d res s. ^ Pr I ces subjecttochange
on books not published! by 73 Magazine^

FOR TOLL FREE ORDERING CALL 1-800-258-5473

ANTENNA BOOKS

THE WELL
BgUIPPBD

HAM SHACK

PRACTTCAL ANTENNAS FOR THE RADIO AMATEII

^A manual describing how to equip a htm stition with
a su liable antanna. A wide range of antenna topics,
systems r ^^^^ ac^cesaorles are pfeaent^d giving the
readi^r some food for 1 bought and practical data for con-
struciioa Designed to aid the experienced ham and
novtce as well. Only BK1015 $9.95/

VHF ANTENNA HANOeOOK-The new VHP Antenns
H§n{^bQQk details the theory, design, and cOn$tructl'On
of hurtdreda of different VHF and UHF antennas... a
practical book written for the average amateur who
lakes }oy in buHcfing, not full of ^rinp^ex formulas for itie
design ertgineer. Packed wfth fsbiilous antenna projects
yoy can buikf. f5 95/ 3X7368

73 DIPOLE AND LONQ-WIRE ANTENNAS~bv Edward
M Nolt W3FOJ. This is the hrst coriaction of virtual ty
every type of wire antenna used ^ amatwrs. Includes
dlm«rtslons,conrigyration3,an(f detailed construction
data foe 73 d Iff a rant antenna types. Appen drees
describe the consi ruction of noise brl<dgea, fme tuners,
an<} daia on measuring resonant frequency^ velocity
factor, and swr, $5,50/ BK10ie

• ALL ABOUT CUBICAL QUAD ANTENNAS {2n4 edi-
tion)—BK1 196— The ^'Clftsaic" on Quad deslgji,
theory, cronslructfon, and operation. New 2nd adlttofi
contains new fe»d and matching systama and r»»w
data. tSJS/

• BEAM ANTENNA HANDBOOK (New &lh •dlllon}—
BK1 1i7— Vagi beam theory, construction and operation,
tnfomialion on wife beams. SWR curves and matching
systems, A "musi^ tor serious DXefs, S5.96"

• VHF HANDBOOK FOR RADJO AMATEURS— BK 11 96
— Contairts information on fM theory, operatkm aiKf
equipment. VHf a ntenns design and construction, satef-
lita-EME. arxf tn«^ rvewest solid-^tate circuits. V&95*

• THE RADIO AMATEUR ANTENNA HANDSOOK-
BK11W— Aii at>out wire antennas, beams, tuners,
baluns, coax, radial:^. SWR and towers. Clear artd com-
plete information, $6.9^'

• SIMPLE, LOW-COST WIRE ANTENNAS FOR RADIO
AMATEURS— BK 1200— Atl new data and every thing you
want to know about low-cost, muiti-baind antennasjnex-
l>enslV0 beams, "invisible" antennas for hams In
'Uough" locations. $6.95''

COOK BOOKS

TTL COOKBOOK— by Don Lancaster. Explilne what
TTL Is, how It works, and how to use it. Discusses prac-
tical applications, such as a digital counter snd
display system, evants counter, ^Eectronic stopwatch,
digital voltmeter and a digital tachometer.
iSo/ BK1063

CMOS COOKBOOK— by Don Lancaster Details tt>e
application of CMOS, the low power logic (amrly
suitable for most appHcatlons presentiy dominated by
TTL Required reading for every serious digital ex-
penmentar! $10.50/ BXlOll

TVT COOKBOOK— by Don Lancaster. Desorfbes the
usa of a standard television receiver as a micropro-
cessor CRT terminal Explains and describes charac-
ter generation, cursor control and interface Informa-
tion in typical, easy-to-understand Lancaster style.
59^5/ BK1064

SPECIAL OFFER

Chmrtof

imiTED STATES AMATEUH

RADIO FRIYILEGES

hf claaa ef Uceoae* cmi^itoo trpc. mad frtr
qaencj from 160 thrtt 2 meterA, £EH!ltidij]^ pTO-
"rlalon Tor the nev 30, 1 7, and 13 meter banda.
TliJi 32 X a« la. tw«lve-<^olor cluut U Uic flrat
of Ita kind to be both InfonnatlTC and decora-
tlve. S3.00 value. Qoij $1.9& vltli the puT'
cliaa« of 1 or more book* from the Radio Soofe-
shop* (9upplle» limited, order aow.)
CH7300S1.0fl.

• HOW TO DEFEND YOURSELF AQAINST RADAR— eKl2Dl — by Bfuce F, Bogner and James R Bodner; a lawy^
and radflj- expert, This book gives you the ammunPtion to challenge the radar "evidence" that usually leads to a
apoeding conviction. The ma^or part of the booK details the inner workings of radar— you'U beoome mofe of an ejc-
pert than most pollcs officars and judges. The rernalndflr of I he book out lines how to defend youraalf against a
speeding ticket— the observations, measures and testimofty you must obtain to defand yourself wfthout the help of
a lawyer The price is a tot less ttmn a fme! $6-95'

WOflLD REPEATER ATLAS— Completely updated, ovef
230 pages of repeater listings are indexed by location
and frequency. More than SO map^ pinpoint 2QQQ repeat-
er locations throughout the USA. Foreign listings In*
duds Europe, tiie Middle East, South Amirlcan and
Africa, S4,»5* BK7aiS

THEMAQICOF HAM RADfO- by ctenoid Swank WSHXR
begins with a brief histoiy of amateur radio arnlot Jerry's
in^vemervt in it. Part 2 detilis many of ham radio's
I*af0*c mo<i>entfi. Ham<iom s dose ties wtth the cont^
nent Of Antarctica are th« subfaci of Part 3. In Part 4 ttw
Strange ar>d humorous sides of ham life get tf^tr due.
And what of the ftjiure? Pari 5 peers into tfis crystaJ bill.
S4.95/8K7312

A QU1DE TO HAM RADlO-by Larry Kahaner WB2NEL
What s Amateur Radio all about? Vou can learn the
basics of this fascinating hobby with this excellent
beginner's guide. It answers the most frequently asked
questions in an easy going manner, and il shows the
best way to go about getllng an FCC license, A Guide to
H«m Radio IS en ideal introduction to a hobby enjoyed
by people around the world ^ $4.95/ SK7321

WORLD RADJO TV HANDaOOK 1ii2, 25TH EDITION
— This book is the bible pi international broadcasters,
providing tf^ only authoritative source of exact informa-
tion about broadcasting and TV stations world wide.
Th^S ?9S1 edftion Is completely revised, giving conv
Dfihensive coverage ot short, medium and long wave,
560 pages of vital aspects of world listening
liaso. &Klia4

MICROCOMPUTER BOOKS FROM 73

C(HMPIJTEK

GAMES

ftom

1-:* rjoucj microconnputin^

• SOME OF THE BEST FROM KfLOBAUO/MICROCOM-
PUTINO— 6K731 1— A collection of the best artiqles that
have recently appeared In Kilobaud/ MICROCOMPUT-
ING. Included Is material on the TRS-80 and PET
syslems, CPfM. the 8080/8085/ZeO chips, the ASR^3 t«r*
minal. Data base management, word processing, text
editors and f lie structures are covered too. Programming
techniques and hardcore hardware construction proj-
ects for modems, high speed cassette interfaces arbd
TVTs are aJso ir^cluded in this larige format, 200 plus
page edltioti. 1 10.96,'

1 40 COMPifTER GAMES— BK73B1— Forty D«mes In all
in nine different cateoories Games fer targe arid small
systems, and even a section on cafeuletor gam«s. Marty
versions of BASIC usad and a wide variety of systems
represented, A must (or the senous computer ^mes-
mail. S?.9€*

• THE NEW HOBBY COMPUTERS- BK 7340 -This
book takes it from where "H08BY COMPUTERS ARE
HEREI" leaves off, with chapters on Laroe Scale Integra-
tion, how to choose a microprocessor chip, an IntroouC'
tlon to programming, low cost I/O for a computer, com-
puter arlthmstic, checking memory boards... and
much, much moral Don't miss this tremendous value!
Only $4.95/

• UNDERSTANDINO AND PROGRAMMINQ MfCRO^
COMPUTERS- BK7a&2- A valuable addition to vour
computing llbfary. This two-part text Includes the best
articles that have appeared in 73 and Kilobaud
Microcomputing magazines on the hardware and soft-
ware aspects of microcomputing. Well-known authors
and well-structured text helps the reader gat Invoivsd.
$10.95*

HOW TO BUILD A MICROCOMPlTTER—AliD REALLY
UNDERSTAND rT— by Sam Creason. Th« electronics
hob&yist who wants to build hrs own mlcrocomputef
system now has a practicsl "Kow-To" guldet>oOk. This
book Is a combination technical manual and progfam-
ming guide that takes 1h« hobbylsf step^-step thrtHK}h
iha d«slgn. construction, testing, and debugging of a
complete microcomputer system. Must reading for
anyone desiring a true understanding of small computer
systems 59,95/ BK7352

HOBBY COMPUTERS ARE KEREilf you want to come

up to speed on how computers work—hardware and
software— this la an excellent book. It starts with fun-
damentals and ©xplalna the circuits and the basics of
prog ram m in o, along wllh a couple of TVT construction
projects, ASCII. Baudot, etc This book has the hlohest
rpcommendalions as a teaching aid. $4.95/ BK7322

*Use the order card in this magazine or itemize your ordar on a separate piece of paper and mall to: 73 Radio Bookshop •
Petert>orough NH 03458. Besuretoir>clud6Check0f detailed credit card information No C.O.D. orders acGSptSd, Ail orders
add It. 50 harKll^ng first book. Si. 00 each additional book, SlOOO per book foreign airmail, Please allow 44 weeks for
delivery. Questions regard! rig your order? Please write to Customer Service at th^aDOVe address^ (Prices tyib|ict to change
or^ books r»at published by 73 Magazine.}

FOR TOLL FREE ORDERING CALL 1-800-258-5473

LisT of AdvERTISERS

To receive fuW inforinatton from our advertisefs
please complete (he followmg postage-paid carcJ

R.&NQ.

P«t6

Its. Mo.

Page

2 AEA/Aclvanced Eiecironic Applies
Hons. .......... ....... 53

329 ARTochnkal Products. ,,,. .h ...fl3
448 Atlvancfld: ComrrunlcallonB Inter-
national ,..,.,...,.., 37

406 Alaska M'crovtrave Labs. .. .^,.,.77

20 All eiBcifonics, 38

402 AlumaTDwer..... ^36

Amaieur Electronic Supply 63

5 AmaTaur-WtKilesafe Electronics. . 25
331 Amateuf Wholesale El«ctrofiics, . 45

334 Am idon Associates ,,,.,. „1^

7 American Crystal Supply, 153

97 AMP Lgtter 153

Antenna Bank . . 147

Associated RadJO V46

* Auieh Research. 147
4S9 BG Carl Electrontcs. . 100

11 Bari^er & Wii I lamsdd. ...... T49

305 Barry Electronics. 53

2€ Baah Educatforial Services 58

440 Rex Basket t Electronics, Inc. 73. 152
420 Benjamin Michael Induatnes^ - . 147

Srilts Two-Way Hadio^AEA t4S

12 Bullet Electronics,.... 156
&ufternut Elect rwiECS 31
CAARotwrtsfAEA 69

321 Certified International .154

m Ctuttedree Modular Consoles 146

CO(*o Qtiick,,... 154

^ Connnsoft ...,, 101

28 Communications Cer>lef, NE 172

362 Communication Concepts, Inc.. 145
377 Communioations Electronics. . . 157
462 Communications Electronic

Specialties . , .,,.. 1 51

1 5 Communi cal Ions Specl a I Ists . 10, 1 1
444 Computer Plus 154

Crown Micro Products. ..... 71, 152

70 Cubic Communications, ........ 57

307 Debco Electronics. 133

[>efT»ch Electronics/ A£ A 150

t>esklop Computrng 141

477 DFO SKSteffTO*^..*. 1T9

DGMEf^cifonlcsjRC- .,,,,,»., 142

* Digit tl Research Parts. ITS

43 ONE, Inc 13S

425 Doppler Systems. . 1 54

■

R, L Drake Compsnjf.

..91

•

DXpedilions International. . . .

.62

453

E'GhE^i Inc.. ...... .......

.142

80 MIcrocompuliriQ

.144

Electronic Equipment Bank, . . .

.145

447

Elect ran EC Hobby innovations.

.101

Electronic Recyclers o( MA

153

400

Engineering Consulting .

154

Erickson CommunicatJOfiS. . .

..&2
,149

eTCo tiectronics.

Fexscan, Ino,,.,,,,, ,,

,138

-439

Ben Frankrin Eiectrofites, .-...

323

Fo*-Tari§oCQrp..

44£J

Fronlier Eniefprises

irv\

tOl

G It K Amateur Supply

..23

Gtllaspielt Associates

.99

•■

Gefn Ouad Products Ltd, ....

.75

Global Electronics, . ....«^.«*,

..m

417

Gotham Antenna. . ■

.155

Grove Enterprises.

..45

HMRlt

154

fl6

HSR CommuntceHons. ♦....,

345

Hal Communications. . . ^

.17

479

Hal Coftimunications.

.136

HalTronlst.

137

■

Ham Radio Outiei

. .3

Hamtfonics, NV

.173

460

Harfdi-Tek

154

Hastings Antenna. .........

..m

Heath Compeny ...,...,..

..37

303

Healh Company..,,,

...9

Her^ry Radio.

bigain Electroniics. . » . , .

316

Myosin Div. ot Tetex Ccmm.

..*, 47.a4,BS

Hooiler Eiectf onlca. ,........,

,,95

Hustler, tnc ...,.,..,

..43

474

MX Equipment

.49

■

ICOM ,,,.., Gov 11,29

■

iWL - ..„.

,/15

Independent Crysta! Supply Co.

.153

IfKty Amateur Suppty. ,...,.,,.

.las

lnto-Tech._. ,.._,,...,_,.,,

.52

445

instant Soflwant

De*^s.

. 103

Amateur Radio Programs

--^^- 102,109

.109

nS. Na P»o«

27 Iscan Engineering. 155

409 JDR MfCrodevJcas ..,..,,.116, 117
25 JJT D^stribLiilnQ. .............. ISS

38 Jameco Electronics. . , 177

KB Microcomputing. 144

Bl KDK Distributing — .... . . , 19

4?6 KDK Dislnbulinfl Hi

Kantronics .... 150

• Ker^wood, Gov iV, 7
4 t-acue Communications

Electronics ,.♦.»*»,,,♦ ...«,..•- . I5t
457 Uwis Construction Co.. . 100

Live Vie Sarelltte. lr>c.. ..9&

480 LNR Communications.... 135

53 Luly Assoctales. ...... >-. 99

96 M&MEJecironicsSaJes ...32

47 MFJ Enterprises

67.69.71,73,75.77.66

47B MFJ Enterprises- . , 136

45 MHz Electronics 156-157

77 M- Squared Engineering. ....... ISO

56 Macaw Electronics, — 146

44 Macrotronics, Inc 75

45 Madison Electronics Supply. . . , 151

4ft Maggiore Electronic^. 140

139 Memphis Amareur Etectroniios . 28

49 Micro Control SpeciaUtes 77

51 Microlog . - 79

313 M^cfo Wanagiiiiant Syst^mfi. .156

50 MicJ0CTaflC5*p.. .....,.,.. ea. 156

52 Mid-Com Electronic* 148

308 J, W. Miller Div./Bell IndustriesSI. 33
' Mirage Comm. Equip., Inc, .,.,,. 73

31 S National Comm. Group tOO. 139

412 Nemal Electronics^ , . , . — ... 46
327 Horciluncl & Asaodaiea. 9S

* Orbit Magazine,.,,,., ,.,,, 137

P.C. Electronics 100

Palomar Engineers,,,,.., ,.4

404 P. B, Radio Service 152

421 Pliillips Tech Electronics i53

300 Pipo CofnmuntcalionS. - . 153

96 Powef Gain Antennas. . 33

459 QRO EnQJiie^ring T3B

9i QRZ Scait, Inc. 49

60 Ouest E^ec1ionice-.-...^^-..-. 166
21 R.W.D.Jnc- t4i

R.&NdL Page

61 Radio Amateijr Can ltxx>k, Inc 33
Radio Publications . ... 1 19

381 Radio Systems Technology I Inc. 153

454 RadiokM 69

397 Radio World 156

Radios Unlimited^AEA. .... ,24

62 Ramsey Electronics. . , 1^. 174

4ia RollnDistfibutocs 24

96 S. G. Doscoe. . 3B

376 SMP 151

65 S-P Amateyr Radio Service — ..71
64 SemtcortdbCtors Surplus. 170,171

73 Magazirbe

Books , .110-113. 143, 144

DteaiemAd. .. ..,.,..*.. HO

"Mo¥ing ...,,♦*,,» 137

SubscHpttons . - , . .^ * . . . 1 15, 154
University Microtilms. . . 155

Sherwood Engineering t65

433 Skytec... 154

367 Slep Electronics 139

309 Spacecoast Research Corp.. * - . . 98

* SpectromcSj Inc - — 71,176
6fi Spectrum Communications. .61
436 Spectrum international. Inc. 100, t39
32 Steiimaker EniefpriseSw t55

30 Stfujt Corp,,*..,... 153

69 Surplus Electronics Corp . 155

316 Tehex Conrnuimcations, Inc.

, 47,64,85

Ten-Tec. Inc^ 135

328 Texas MleroironlcSv , . . 49

449 The Main ShacK. i52

57 The Tuned Antenna Co. ... 67

76 Trac EleclfOnics 43

88 Tufts Electronics . 60, SI

* Universal Communications 140

* Van Gorden Engineering ^ . 43

481 Valor Enterprises. ......... ^ .. . 136

31 1 Vanguard Labs 153

90 VoCom Products Co.. ^......,...^.39

302 W-S Engfneerir>g. . 73

79 Wacom Products......... ...... 150

Wi^sexPutJlishingCo,. 138

29 Windwaid. Inc .- 24

63 Yae$y ElecmmiCS Co ...Covin

BooksrETC

Citilog* ^tein Prtei

. 1ft 10

7$ MAGAZINE

To order, complete the following postage-pard card, or itemize your order including
detailed credit card information or check and mail to:
73 Magazme/Mail Order Depi./Peterboroygh NH 03458.

Ilvrfl

StOQCO

smoo

STOMO

STiixn

8T2501
BKilfr

wryar

BK730B

CT7305

CT7313
CTT99

Ct73»

BK^oe
SO 7:11^

mruz
bursas

BR1»t

n &ACK issifE-

.^^ s im

73 S*Clt issues- »OOI1CMOIC£ I1?C0
73 &ACK tSSUES— SYOUR CHOHCf S & ?5

n B*CK, issuis— 10 voyn c»taiCE

,..-._.. .„,__ -.„*H.OCI

73 BACK lSSUES-» TOun CHOICE

»aoo

ALL ABOUT CUBtCAL OUAD ANTENNAS

t.bh,^ ri ■ T 1^1 in-- - T I I i i I I I i I ■■^H^i ii^y^ 3 VD

BEAM ANTENNA hAN0BOOIt„ A 505

B£Hlt^D THE OtAL . I «flS

CHALLENGE OF iW S * «

CliOS COOftSOOK. mtnna

CdOETAM— SWPM _j *m

COCC TAPE— 1* WPm. J 405

COOEIAK-U* WPM I 4»

coot TAPE- 20* WPM J 4 05

COD£TAP£— S+ WPU 14^

CODE TAPES I AN f FOUR ABOVp flS.H

TIME CONTEST QOOKSOOR.,. 4 Sflft

4&C0MPuTf n GAMES .% 705

GENEHAl lfCENSESTIjaV<SUlDt.5 flSS
GIANT BOOK OF AMATEUR HAPiO

ANTENNAS,.,.. --..,.-■,■ .112,05

A GUIDE TO MAM RADIO ...,.^ i 4 06

HOBBY COHPUTfRS ARE HERE t 4 05

HOia TO BUILD A MiCnOCOMPUTER i
iiPAi I V ufciof agTAiun it f ^^

HCMf TO t5f FEND VOUBSELF AfiAIKST
flADAR^ - 1 6 95

Catalog

SAiOZB iCORAMPCfKM^eOOH.

Price
J1205

Cilalog «

II (m

FOn RAOiO AMATmHt&.

Price
.9 ej6

IMTERFERENCe HANOflOO* J$ 09$

KAGiC OF HAU flAOlO T 4M

WIASTEil HANDBOOK OF HAM PlADiO CUR.

OUITS _.. .. ^ „t B.B

BKT34CI TMENEWMOftaYCOMPirreiS. J 4.ftS

BKr3&3 THE NEW WEATHER SATEiUTE

n AN P BOOK, i..i..D.....i;, I 111. ,...»...»..... S o 00'

CT73CtO NOVlCe THEORY TAPES, ....«15.?&

&K7310 OWNER REPAIR OF RAptO Et^UiPhtENT

^^.^. s 7.*a

mti.ry35 powea supply hanobook j b «

BKtOi S PRACTICAL ANTEN N AS FQfl THE RADIO
AMATtUfl „ » 0i&

an $ ti5 THE PRACTICAL HAMOBOQK OF Fli

ft£P£ATtRS____ J 0.ia>

axnoa pnopAOATiON w^Ams hamdboqk

1 tJB

OW0S£e O&L CAftDS - STYLE W -23Q_

Bi^73ll
BICr351
CT7350

SQiDSt
SQ10B0
SG7367
&K11B0
LBT3ge

Laraao

LB7»i

OWtKOO

0W3W

QX0500

OY0S5C

OYOMO

BK1109

BK1CN4

Bxiooe

8ICTS0Q

OSL CAUDS— BTYU M -SU.

—I a05

OSLCARDS^STYL5M-2S0._„„...t 0 09

OSLCAHOS-STYLf X^SOO. ^.t13.!ft

OSU CARD&^&TVLE Y-25a _...» Q 0i

OSL C ARDS^ Sty L E Y -500 .»1 3 ,BS

THE RADIO AMATEUR ANTENNA

HAND&OOK..... - ^ SM

RFi DIGITAL TCST EQUIPMENT....- J tiS

RTL COOKflOOR- ^ t eSO

SHELF BOX—* ,^ I 2.00

SWELF BOX ES- 1 f :it SO ucn

S«ELF a03teS-4 AHO UP- It.25
SiMPLf, LOW C^^T WlR£ AHJ^HN AS

aKn4fl
BAioia

6K73«^

CHTIOO
BK10e«

BK119B

BK7370
B«130?

BKtia«
BtCOIS

SOME OF THE B£ST FAOM ^liOSAUO

— rtow

30«IEOFTHEB£ST f 7 86

SSe THE WiSuNDERSTOOU MODE..! S.SO

SSTV TAPE { 5,9S

STUDY GUIDE— ADV GLASS.. , J 695

ST U D V G U I DE- iXTR A CLASS. . - . J 5.fl5

3TUPV GUIDE-NOVICE CLASS $ 4.fl5

THE TEN METER FM HANDBOOK S 4^
TEST EQUIP US VI -COMPONENT

TESTERS-^^ .. * 4 35

TEST EQUIP UB V?- AUDIO TISTH^

S 43S

TE5TEDUIPUBV3— PlAOtOEOlJfP $ 4J6
TEST EOUIP UB tf4— IC Tf ST EG _J A.BS
TQOtS 4 WCHmOUm % 40S

TTLCO0li90<M f 3 50

Tin COOKBOOH * B.es

UNf3EllSTAP«tnNG 4 PFID^RAMMING
MlCWOCOMKTTEWS ..|ia.0&

tJ.S. AMAtEUR RADIO CHART .^^1 95

VEmit^Ai BEAM & TRIANGLE ANTM5

: .... ... ,..l 5.50

VHP ANTENNA HANDBOOK S 5,95

VHP HANDBOOK FOR RADIO AMATEURS

■ ■JiB^MJiii 1 n , . . . . f 0.39

WEATHER SATELLITI HANDBOOK.! 2-SO
MK>RLO Pf^SSS£RVtC£ FRCOUENC^ES

— . . .1 SJS

WOAU} RADfO TV HAMOlOOit SfC 5fl
WOAUlf^FEATERATLAS t 4 05

114 73 Magazine • February, 1982

WHAT WILL YOUR NEW

RIG BE LIKE?

Read 73 and Find Out

The magic of digital electronics is coming to ham gear . . , and you'll be able to read about these
developments in 73. There probably will be more changes in ham equipment in the next few
years than ever before in history. You'll see these changes coming in 73, where you'll read about
the experiments and pioneering. 73 has more articles than any other ham magazine . . , often more
than all the others combined.

When sideband got started, it was moved along by the many pioneering articles in 73. In the 60s
it was solid state, with sevfcfal times as many articles on the subject than in all the other magazines
combined. When repeaters and FM got going about ten years ago there were over five times as
many articles on the subject published in 73 as in all other ham magazines combined . . . and you
can see what changes that brought to hamming. Now we're looking at exciting developments
such as narrow band sideband for repeaters . . . which might give us six times as many repeaters
in our present bands. We're looking at automatic identification systems which may make it possi-
ble for us to read out the call letters of any station tuned in . . . and even the development of self-
tuning receivers.

Will stereo double sideband techniques make it possible to have up to 30 times as many stations
within a given HF band as is now possible? Hams will be experimenting and reporting on these
developments in 73. 73 is an encyclopedia of hamming. . .present and future. . .and just a bit of
the past, too.

Without the endless fillers on station activities and club news, 73 is able to

publish far more information. . .valuable information. * ,on hamming and r-— ^.,..-.,_

ham equipment. | ^|U--. , : '^^

You may or may not be a pioneer, but you certainly will want to keep up t^S^^^^m^H

with what is happening and what the new rigs are going to bg hke. And, frank- |- w^^^

ly, your support of 73 is needed to keep this type of information coming. fes -/jfinH^

"tf ©©o bill me for 1 year of 73 Magazine at 325.00

^ 32aB6

Name.

Address.

City . State Zip.

Canadian S27/1 year only. US funds. Foreign $35/1 year only. US furds

Please allow 4 to 6 weeks for delivery
73 Magazine#PO Box 931»Farmingdala NV 11737

ISMagazine * February, 1982 115

4116-200ns

ALL MERCHANDISE 100% GUARANTEED!

CALL US FOR VOLUME QUOTES

EFROMS

Eieh

8 p««

1T02

256 1(8

itfisj

4.95

4,50

tim

1024 s a

(450n»j

2.93

2.75

275B

1C^4»8

<5V) (450na)

9.95

8.95

TMS2S16

2max8

(5V) (450n»)

6-95

5.95

2716

2046x8

iSV) (4mm]

5.50

4,95

2716-!

2048x8

iSVy (SSOnsJ

5,00

8.50

TMS2716

2048 itB

(450ns)

995

8.95

TMS2532

4095x6

(SV^ (450n»)

12.95

11.^

2732

4096x6

{5V) (450nsj (200 ns J

CALL

2764

8192 >f 6

tSV} (450rh8)

CALL

DYNAMIC RAMS

100 pem

^027

4096 K 1

(250ns)

2 50

2.00

411&120

16.384 X 1

(120ns)

3/29.95

CALL

4116-150

16,384 X 1

(iSOns)

8/16.95

1.95

4116 200

16,384 X 1

1200 ns)

3/15.95

1.80

4115-300

16,384 X 1

(BOOns)

3/14.95

1.75

4164

64,536 X 1

(200ns)

CALL

STATIC RAMS

100 pc«

2101

256 k 4

(450ns)

1.9S

1.86

2102-1

1024 n T

f4S0ns}

.89

21LQ2 4

1024x1

(LP)(450ns>

1.29

1.15

21L022

1024 X 1

(LP) 1250ns)

1.G9

1.55

2111

256x4

(450fl»)

299

2.49

2lt2

256x4

(450ns)

2.99

279

2114

1024 X 4

f450n5}

8^16-95

1.95

ai14L2

1024 « 4

(LP) iSOOn*)

a/t9-95

2114L-3

1024 X 4

(LP>i300ns)

S/ta.95

2?6

21141-4

1024X4

(tP) i450n*)

8/17.95

210

2147

4096 X 1

(55n3>

9.95

CALL

TMS4044-4

4096i1

(450*is)

3.49

3.25

TMS4044 3

4096xt

pOOns)

3.99

3.7S

TMS40L44-2

4096x1

(LP} (200nfl^

4.49

4.25

TMM201$

2048x3

(200ns) (150ns)

CA1I

HM6116

2048x6

(200ns) ( iSOns) (I20nsj CALL

CRYSTALS

LP = LOW POWER

74LS00 SERIES

74LS00

MLS01

74LS02

74LS03

74LS04

74LS05

74LS0S

74LS10

74 LS1 1

74LS12

74LS13

74LS14

MLS15

r4LS20

74LS21

74LS22

74LS26

74LS27

74L5ae

74LS30

74LS32

74LS33

74LS37

74LS38

74LS40

74iS42

74LS47

74LS48

74L&49

74LS5!

74LS54

74LS55

74LS63

74LS73

74LS74

74LS75

74L:576

r4LS78

74LS83

74LS85

74LSa6

74LS90

74LS91

74LS92

74LS93

74L595

?4LS9B

74 LSI 07

74LS109

74LS112

74LS113

74LS114

74 LSI 22

74LS123

74 LSI 24

74LS125

74LS126

74LS132

74LS136

74LS137

74LS13e

74LS139

74LS145

74LS147

74 LSI 48

74LS151

74LSt53

74LS154

74LStS5

74LST56

74LS157

74 LSI 56

74LSieO

74LS161

74 LSI 62

74 LSI 63

74LS164

74 LSI 65

74LS166
741S168
74L6169
74LS170
74LS173
74LS174
74 LSI 75
74LS181
74LSia9
74LS190
74LS191
74LS192
74LSt93
74LS194
74LS195
74LS19B
74LS197
74LS221
74LS240
74LS241
74LS242
74LS243
74LS244
74LS245
74LS247
74LS24B
74L5249
74LS251
74LS2S3
74LS257
74L&258
74LS259
74LS260
74LS266
74LS273
74LS27&
74LS279
74L&2eO
74LS2a3
74LS290

74LS293
74LS295
74LS2^
74L&324
74LS352
74L3353
74LS363
74LS364
74LS365
74LS36e
74LS367

74LS36e

74LS373

74LS374

74LS377

74LS378

74LS379

74LS385

74LS38e

74LS390

74LS3g3

74LS395

74LS399

74LS424

74LS447

74LS49D

74L3668

74LS6B9

74LS670

74LS674

74LS6a2

74LS6S3

74LS684

74LS685

74LS688

74LS6e9

81LS95

eiLS96

aiLS97

81LS9S

32 768 KHZ

3.95

1 0 MHZ

495

1 8432

4.96

2.0

3.95

2 097152

3,95

24576

3.95

3.2768

3.95

3579545

3.95

4 0

3 95

5.0

3.95

5.06BS

3.95

5 185

3.95

5.7143

3.95

6.SS36

3.95

395

10.0

3.95

14,31818

3.95

18.0

3.95

18.432

3.95

20.0

3.95

22.1184

3.95

32,0

3.95

MISC.

Ay5-2376

12.50

11C90

13,95

XR2206

4f»5

3242

7 95

3480

900

MC4024

396

MG4044

4.50

7103

9.50

7106

7107

1295

76477

3.95

8038

396

95H90

799

9602

150

January Specials

DISC CON-
TROLLERS

1771
1791
1793
1797

24 95
36 95
44.95
54.95

UARTS

AY3-1014 695

AY5-1013 3.95

TR1602 4,95

IMG402 7 95

INTERFACE

erae im

eT28 2 49

flT96 .99

aT96 jgiB

6T97 .99

8T98 .99

OM8131 2.9S

0S8636 1.29

CLOCK
CIRCUITS

MM53e9 3.95

MM5375 3.95

MSM5832 7.45

7207 7.50

7206 15.95

CONVERTERS

MCI 408 L8 4.95
DAC-0800 4.95

ADCQa04 4.9i

Z^OAGPU

Z-80A-PIO

8214

8216

6800

6810

6.00
6,00
2.95
1.50
4.95
3.95

IMS 40L44-20
4096 X 1 low power 200ns RAMS

By Texas Insuumems ■ not equivalent pari
number made by another manufacturer as
sold by oihers:

4.49 each 125.00/32 pes.

Spactali and Jangiry 31 , 1 962
P36ast stili "Jcnyiry Sp«cials'^
whvrt ofdarirtQ

800-538-5000
800-662-6279

(CALIFORNIA RESIDENTS^

CALL JOR eeFORE YOU BUY!
WE WILL BEAT ANY COMPrnTORS' PRICES

CMOS

74C00
74C02
74C04
74C08
74C10
74C14
74C20
74C30
74C32
74C42
74C48
74C73
74C74
74076
74C83
74C85
74C86
74C89
74C90
74C93
74C95
74C107
^40150
/4C151
74C154
74C157
74C160
74C\Bl
74 CI 62
76C163
74C164
74CtK
74C173
74C 1 74
74CT75
74C192
74C193
74C195
74C200
74C221
J4C373

74C374

74C901

74C902

74C903

74C905

74C906

74C907

74C90B

74C909

74C9tO

740911

74C912

740914

74C915

740918

74C920

74C92t

74C922

74C923

74CB25

74C926

74C927

74C928

74C929

74C330

4000

4001

4002

4006

4007

4006

4009

4010

4011

4012

4013

4014

4015

4016

4017

4018

4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4034
J035
404D
4041
4042
4043
4044
4046
4047
4049
4050
4051
4063

4068
4069
4070
4071
4072
4073
4075
4078
4078
4081
4082
4085
40B6
4D93

6502

65C2

6S02A

6504

650S

6507

6520

6522

6532

6551

Z80

ZBOCPU
Z80ACPU

zsO'Piq

zaoAPio

zaocTc

Z&OA'CTC
ZeOOART
Z80ADABT

zaoo^A

Z80A DMA

Z8OS10/O

ZSOASiOJO

290-810/1

ZSOASlOn

Z0&S1OV2

zaoASiQ^

Z8aSlO«9
Z80AS1Q/9

Z80BCPU
Z80BCTC

zsaspio

28671
.^^6132

409Q
4099

T4409

1^4410

1 44 1 1

14412

14419

4502

4503

4508

4510

4511

4512

4514

4515
4518
4518
4519
4520
4322
4526
4527
4528
4531
4532
4538
4539
4543
4565
4S66
4581
4582

4584

4585

4702

4724

B0C07

80C95

80C96

80C97

0OC98

a. 95

6.00

6.50

600

595

865

15.25

1875

1750

27 50
23 95
28,95
23.95

28 95
23 95
28 95
17 95
22.95

18.95
1795
17.95

^.95
34.95.

HOURS: Mon. - Frl,. 9 to S; Sal., 11 to 3

VISIT OUR RETAIL STORE!

inaslei cnargt*

ViSA*

JDR MICRODEVICES, INC.

1224 So. BasGom Ave.

San Jose, CA 95128

800-538-5000 • 800 662-6279 (CA)

(408)995-5430 * Telex 17M 10

TERMS: For shipping include $2 00 for UPS ground, S3. 00
for UPS Blue Label air SlO.OO minimum order Bay Area
regldenia add 6v^% sales tax. Califomta residents add 6%
sales tax, We reserve the right to llmii quantities and sub
slHute manutaciurer. Prices subject lo change witnoyt
notice Send SASE for complete list.

116 73Magazine • February, 1982

271 6 EPROMS 450NS (5V)

ALL MERCHANDISE 100* GUARANTEED!

CALL US FOR VOLUME QUOTES

80QO

8200

S035
&039

doeoA

SOBS

3085A2

3086

8086

8155

3156

8185

3ie&'2

8741

6746
&755

1695
1995
3.95
1295
16.95

39.95
11.95
1195
2995
39 95
39,95
29.95
44.95

6800

63Q0
6602
6608
6609
6809E

6aio

6820
6821
6828
6834
6640
6643
6344

6645
6847
6850
6652
6660
6662
6675
6880

6BB0O
66821
6SBS0

8202

8205

82t2

62U

8216

3224

8226

6228

8237

6238

8239

8243

8250

8251

8253

8253r5

8255

8255^5

8257

6259

8272

6275

8279

6279-5

6282

8263

8284

6286

8287

8288

8289

10.95
12.95
12.95

LEDS

Jumbo Red
Jumbo Green
Jumbo YeHow
5062-7760 43'CC
MAN74 =3CC
,MAN72 .3'CA

lonoo
en .00

6/1 00
.79

TV
CIRCUITS

MCI 330 1.89

MC1350 1.29

MC1366 V79

Lhl380 1.29

LM386 1.60

LM565 .99

LM741 .29

LM1310 2.90

LM1&00 2.99

LM1889 1.49

EPROM ERASERS

PE-14 78.50

PE-14T (with timer) 10830

PE-24T (with timer) 154.50

ALL ARE HtGH QUALITY UNtTS ENCLOSeO IN
A 9I>CK ANOOIZEO ALUMINUM ENCLOSURE

OUR AD MAY BE IMITATED BUT
OUR SERVICE CAN NEVER BE
DUPLICATED.

VOLTAGE REG'S

7805T
7808T
7eiZT
7815T
7824T

780SK

78T2K

7615K

7eL05

7eL12

7aLl5

LM309K
LM317T

7905T
7912T
7915T
7924T

7905K
7912K
?aLOS
79L12
79L15

LM317K
LM323K
LM337K

3.95
4.95
3.95

T = To^220 K = raa l = Ta92

74S00 SERIES

74SO0

74S74

.69

74S163

3.75

74S257

1.39

74S02

74385

Z39

74S166

4,6S

743256

1,49

74S03

74306

1,44

745-163

544

74S260

1,83

74S04

.79

74S112

1.59

74S174

1 09

743274

19.96

?'4S05

74S113

1,96

74St7S

109

743275

19.95

r4Soe

.46

74S114

1.S0

74S161

4.47

74S20O

2.90

74S09

74S124

Z7/

743162

2^95

745267

4,75

74510

74ST32

1,24

7431 sa

3.9S

743266

4.45

74Sn

745133

.98

74S189

14.96

743289

6.98

74S15

.70

745134

7431M

295

74S301

6.95

74S20

-66

74S135

1-48

74S195

169

743373

3.45

?4S22

743136

i.oe

74S196

490

74S374

3.45

74S30

74S139

1.25

74S197

42S

743361

7.9S

74S32

74S140

1.46

74S201

149S

743387

5,75

74S37

187

74S151

1.19

743225

695

743412

2.^16

74536

166

74S153

74S240

3.98

74S471

9.95

74S40

74S157

1,19

74S24T

3JS

74S472

I6.fl*»

74S51

74S156

!.45

74S244

3.96

74S474

17.85

74S64

74Sl6t

2,65

74S251

1.90

743462

15.60

74S65

1.25

74S162

3.70

74S253

745

743570
74S571

7,60
7.B0

LINEAR

LM301V .:

LM30BV S

LM309K 1.^

LM311 1

LM317T 1.S

LM317K 3.*

LM318 1,'

LM323K 4J

LM324 .£

LM337K 3.^

LM339 .%

LM377 2.:

LM380 tS

LMseev 1.*

LM556V ,;

LM556 .(

LMS65 .?

LM566V 1.J

LM567V 1.:

LM723 *

LM/33 .!

LM741V ,4

LM747 .i

LM74«V i

LM1310 2.f

MC1330V 1J

MCI 350V 1i

MC1356 i:

LM14T4 1,1

LMT458V i

LMt4a6 <

LM1469 \

LM1800 2i

LMl8e9 2 J

LM390D J

LM^09V A

LM3914 3.*

LM3915 3,*

LM3916 3.*

75451V .:

75452V .:
75453V

APPLE FAN $69.00

DCTRA PLUG'IN CARDS CAN
CAUSE YOUR APPLE TO
OVERHEAT

ULTRA-QUIET APPLE FAN
DRAWS COOL Am THROUGH
YOUR COMPUTER

ELIMINATES DOWN TIME

SAVES REPAIR CHAFlGES

INCFIEASES RELIABILITY

CLIPS ON — NO HOLES OR
SCREWS

COLOR MATCHES APPLE

LONG LIFE. LOW NOISE
MOTOR

■#

'.}'

*ArFU 15 A TiAqtMARK
OF APPLE COMPUTCR INC

TRANSISTORS

PH2222
2N2222

2N2907

2N3055

2N3904

2N3906

1N4146{1N914)

1N40O4

lorioo

79
101.00
1011.00

100^ 699
S0fl0 39
50^1099
1(V 6.99

IC SOCKETS

1-99 100

e pin ST .13 ,11

14fiin3T .15 .12

16 pin ST .17 .13

IB pin ST -20 ,18

20 pin 3T .29 .27

22 pin ST .30 ,27

24 pin ST .30 .27

28 pin ST .40 .32

40 pin ST ,49 .39
ST = SOLDERTAIL

8 pin VVW .59 .49

14 pin WW .69 52

16 pin WW .69 ,S6

16 pin WW .99 .90

aOpJnWW 1.09 98

22 pin WW 1,39 1.28

24 pin WW 1.49 1.35

26 pin WW 1.69 1.49

40 pm WW 1,99 1.60
WW = WIRE WRAP

CONNECTORS

RS232 MALE 3.25

RS232 FEMALE 3.75

RS232 HOOD 1 25

3-100 ST 3.95

S-100 WW 4 95

DIP SWITCHES

4 POSITION JBb

5 POSmON .90

6 POSlTrON .90

7 POSITION 95
5 POS«TlOfl 95

7400
7401
7402
7403
7404
7405
7406
7407
7408
7409
7410
7411
7412
7413
7414
7416
7417
7420
M21
7422
7423
7425
7426
7427
742S
7430
74^
7433
7437
7438
7440
7442
7443
7444
7446
7446
7447
7443
7450

7400 SERIES

7451 .23 74136

7453 .23 74141

7454 .23 74142

7460 -23 74143
7470 .35 74144

7472 .29 74145

7473 .34 74147

7474 .35 74146

7475 .49 74150

7476 .35 74151
7480 .59 74152

7461 1.10 74153

7482 ,95 74154

7483 .50 7415S
7486 66 74156
7466 .36 74157
74W 4.9$ 74159

7490 .35 74160

7491 .40 74161
74ft2 JO 74162

7493 49 74163

7494 .65 74164
7496 .56 74165

7496 .70 74166

7497 275 74167
74100 1,00 74170
74107 JO 74172

74109 .45 74173

74110 .45 74174

74111 JS 74ira
74116 1.55 74176

74120 1.20 74177

74121 29 74176

74122 45 74179

74123 .55 7*160

74125 .45 74161

74126 45 741B2
74123 .55 74164
74132 .45 74165

,70

74186

74190

74191

74192

74193

74194

74195

74198

74197

74196

74199

7422t

74246

74247

74246

74249

74251

74259

74Z65

74273

742m

74279
74283
74294
74285
74290
74293
74296
74351
743^5
74366
74367
74366
74376
74390
74393
74425
74426
74490

HOURS; Mgn. * FrL, 9 to 5; Sat 11 to 3

mas^ei toary*

ViSA

I-

*^409

JDR MICRODEVICES, INC

1224 S, Bascom Ave.

San Jose, CA 95128

800-538-5000 • 800-662-6279 (CA)

(408)995-5430 • Telex 17M10

VIStT OUR RETAIL STORE!

TERMS: For shipping include SZOO for UPS Ground, S3. 00
for UPS Blue Label Air £10,00 mirnmum order Bay Area
fesidenls add 6^/? % sales tax. Californta residents add 6%
sales ta)( We reserve the nghr to limit quarittties and sub-
siltute manufacturer Pnces subject to cfrange without
notice. Send SASE for complete fiSL

t^Se€ LtSt of Aitlfeftise'^s or} page T T4

73 Magazine • Fedruary. 1982 117

REVIEW

KDK FM-2025 A TWO-METER
FM TRANSCEIVER

When you think about two-
fneter transceivers^ what brand
names come to rnind first?
Chances are, you'll name one of
the big "full line" Imported
labels- There is nothing wrong
with this except that you may be
overlooking some of the other
guys. What about firms like
Azden and KDK? Both concen-
trate on selling a specific but
high-quality line of radios. Until
recently, I dismissed firms like
these as "also-rans." Then I had
a chance to revievw KDK's new
FM-2025A two-meter FM trans-
ceiver. Now Tm a firm believer.

The FM-2025A is the latest in
a series of two-meter mobile rigs
that are manufactured by
Kyokuto DenshI Company and
imported into the United States
under the KDK name. The 2025
represents a rather substantial
departure from the earlier
models, whfch included the
201 5R, a great rig once you
modified it. The staff at KDK has
learned its lesson well; the FM-
2025A offers many of the
features that today's ham ex-
pects yet it remains simple and
straightforward to operate.

Diode Matrix Programming

Like many of its modern day
counterparts, the 2025A utilizes
microprocessor control. In what
seems like a step into the past,
KDK has chosen to use a binary-
coded^decimal diode (BCD) ar-
ray to act as a program for the
computer. Shades of the
venerable I com IC-22S. Or is it?
Twenty-five diodes are used to
program such functions as the
loW'frequency band edge, high-
frequency band edge, transmit
high-frequency band edge, a
choice of S-kHz or 12,5'kHz
steps, the standard repeater off-
set, and band-scan step size.
The unit comes factory pro-
grammed rn a manner that will
appeal to the vast majority of
North American users. However,
if you move overseas or have a
need to operate outside of the
US amateur allocation, it's a
straightforward task to
reprogram the KDK to meet your
new needs.

118 73 Magazine • February, 1982

If you are like me^ most of
your two-meter operating is
done on a few local repeaters
with occasional forays to other
machines if you're traveling-
Perhaps the easiest way to use
the KDK IS to program your
favorite machines into the
memories. There are two sets of
memoryp five channels each.
You can use the channels in-
dependently or in a duplex mode
where you receive on the "A"
channel and transmit on the "B''
selection. Since I frequent only a
few repeaters, I find myself us-
ing the duplex mode. That way, I
don't have to worry about
switching the repeater off-
set selection when 1 change
frequencies.

If you use more than five
channels on a regular basis,
then yoy may want to make full
use of the ten memories by
employing the offset switch for
everything but the repeaters
with oddball splits. The FM-
2025A includes a nicad battery
that provides internal backup
for the memory when the radio
is switched off. The infinitesi-
mal 57'nano-ampere current
drain allows the battery to last
for as long as one year between
charges.

Scanning

The FM-2025A offers two
modes of scanning. You can
search the ten memories for an
open frequency or for a frequen-
cy In use. When the channel
changes status, the receiver

starts scanning again. If you
want to lock the rig on frequen-
cy, just flip the scan control to
the HOLD position.

The same optfons are avali-
able in the band-scan mode. The
scanning starts with the fre-
quency stored in memory A5
and proceeds upward to a limit
determined by the contents of
B6. But you can't fool the rig; if
the B5 frequency is lower than
the A5 selection, there will be no
scanning.

The nice thing about the
KDK's band scanning Is its zero
detector. This ensures that
receiver scanning stops only on
the center of a signal. The only
difficulty I encountered came
when I tried to scan near 144.000
MHz. An internal spur caused a
false locking there.

One useful 2025A extra is a
built-in tone switch. An internal
switch allows you to select be-
tween a continuous tone or a
hatf'Second lone burst. There is
no need to run out and buy a
new encoder if your favorite
machine goes private. There is
easy access to adjustments for
the tone generator's frequency
and output level

Procedures like this are ex-
plained well in the instruction
manual Unlike many manuals
that accompany new gear, the
KDK book is written with the
assumption that the reader has
some intelligence; it presents
more than just an idiot's guide
to installation. You'll even find
four pages of technical and ad-
justment Information plus a
larger-than-usual schematic
diagram.

The KDK's construction is
nothing short of rugged. The
vast majority of the rig's cir-

The KDK VHF FM-2025A transceiver.

cuitry Is on two boards, with the
digital based control circuitry
on one and the rf blocks on the
other. The lack of interconnect-
ing wiring harnesses and ca-
bling leads me to tielieve that
the 2025A will easily withstand a
harsh mobile environment.

The back panel includes a
jack for an external speaker (an d
once you have tried this you will
never settle for a built-in speaker
again), antenna and power con-
nectors plus an accessory con-
nector that includes micro-
phone input, audio output,
transmit-receive switching, and
connection to the IS-volt dc
power supply.

Moving back inside, I noticed
that all of the frequency genera-
tion and most of the audio cir-
cuitry was centered around in*
teg rated components. The rf
section stUI utilizes a fair
number of discrete semiconduc-
tors, but the chip-based
technology is rapidly closing the
gap.

Plus and Minus Points

With a growing trend towards
higher power for two-meter
transceivers, the 2025A holds It
own with a choice of two power
levels, either one of which can
be set between 3 and 25 Watts.
If you need still more power,
then consider an amplifier; you
also get the added advantage of
a receiver preamplifier that way.
Unlike most of the other new FM
rigs appearing on the market,
KDK retains the traditional d'Ar-
sonval meter movement for the
power-oot and signal-strength
measuring chores. I can't knock
the newfangled LED bar
displays without trying them,
but I do know that the old-
fashioned meter makes the
radio look more "professional."

Among the bells and whistles
that you won't find on the 2025A
is a priority channel. Nor is there
a provision for up/down scan-
ning via switches on the micro-
phone. For me, the Jack of these
features had no effect on my
operating style.

Perhaps the biggest draw-
back of this easy-to-use radio is
the close proximity of the vol-
ume/squelch, mode, and memo-
ry-select knobs. They are alf the
same size and easily confused if
you don't glance down at the rig.

On an overall basis, I give the
FM-2025A high marks. It
represents a substantial step
forward In ease of operation.

While it doesn't resemble the
mission-control- panel look
prevalent on a lot of new ngs, it
Is a sophisticated, fealure-laden
radio. It should be especially
popular with amateurs who
want a radio they can tmker
with. The 2Q25A certainly proves
that KDK is more than just the
'*other guys" when it comes to
building radios.

\n (ate t98i. the FM'2025A
was priced at $299. For more in-
formation, contact KDK
Distributing Co., 617 South
Gaffatin Road, Madison IN
37115, Reader service number
476.

Tim Daniel NBRK
73 Magazine Staff

OFD SYSTEMS

RT-89 RTTY SYSTEM

The DFD Systems RT'89
package Is a dfsk-based RTTY
system for Heath/Zenith H89
and H8/H19 computer systems.
It runs under the Heath Disk
Operating System (HDOS), pro-
viding unmatched features and
tiejcibility for the serious RTTY
enthusiast. The system is
designed to operate on a single-
drive, 48K machine with plenty
of space (eft over for disk
read/write files and memory buf-
fer space. All input/output
operations are buffered and
interrupt driven, allowing true
full duplex (send-whlle-receive)
Operation and real-time disk file
read/write capablftties without
loss of data.

There are 66 commands im-
plemented to configure the
system and control program op-
eration. In addition, a special
file. "RTTYINIT.TTY", is auto-
matically read at program start-
up time to establish the mttial
system environment. This frte
can be indrvidually tailored by
the user to automatically boot
the system in any desired con-
figuration.

RT'89 will operate at speeds
of 60, 66, 75, and 100 wpm in the
Baudot mode^ or at any stan-
dard ASCII baud rate from 110 to
19,200, Automatic synchronous
idle (diddle) may be selected at
any of these speeds in either
mode^ and an automatic down^
shift-on*spaG©(DSOS) feature is
selectable in the Baudot mode,
Af[ CW identification Is
automatic, including an ID at
nine-minute intervals during any
single transmission. This
feature can be disabled with a
keyboard command if desired.

In addition, a CW ID shift control
and transmitter on/off control
are available from the computer-

An automatic drsk log is main*
tained each time the transmitter
^s keyed, and mar^ual entries
may also be Inserted on the log
at any time with the N= com-
mand. The time of day is
automatically recorded with
each log entry, so the system
log can also be used as the sta-
tion log if desiredS

System tine width can be
varied from 20 to 80 characters
since the H89/H19 terminaf has
a full 80x25 line display. The
screen is split into four func-
tional areas; a receive window, a
transmit and command window^
a split-screen and statusdis-
play bar^ and a "times square*'
moving-marquee format on the
25th line that displays the
transmitted data as it is actually
transmitted. This latter feature
is useful when the transmit buf*
fer has been preloaded or a disk
file is being transmitted, since
the transmit window displayed
the buffer contents as the trans*
mit buffer was loaded, and the
25th line actually displays the
buffer data as It is being sent.
Therefore, the operator always
'*sees" what is t>eing transmit-
ted over the air at any given
time. The sizes of the receive
and transmitycommand win*
dows are dynamically variable
and may be changed at any time
during system operation, In fact,
any commands may be issued
at any time (except during
transmit), so there is never a
need to stop the program to re-
set any parameters as there is
on some other systems.

The system may be directed
to ignore carriage returns in the
receive window, thus "packing"
a maximum amount of data on
the screen. The carriage returns
are not ignored, however, on the
printer or disk files, so the actoal
format of the received data rs
not lost (you can write on the
printer, read and write on disk,
and receive and transmit all at
once, in real time, due to the
interrupt-driven I/O structure).

Any number of tiles can be
written to or read from disk at
any time, and the printer may be
turned on and off at will, in-
dependently for received and
transmitted data!

A variable-length **word-
correction buffer" is provided to
allow correcting of keyed Input
data prior to its release to the
system. The length of this buffer

may be set from 1 to 80 charac-
ters, and facilitates backspac-
ing over entry errors and correct*
Ing them before transmission.
There are actually two cursors
displayed on the screen: a
flashing underline cursor which
indicates where the word cor-
rection buffer starts, and a
destructive block cursor in-
dicating the next location that
will be occupied by keyed Input.
In addition, the system can be
directed to automatically **wrap
around ' when the end of a line is
reached and no carriage return
is keyed. In this event, the
system will automatically move
the last word keyed to the next
line. If it is incomplete, and Issue
the carriage return itself.

An unusual and very en-
joyable feature provides the
ability to process RTTY pictures.
The system may be placed in the
PIX mode, and overlining will be
allowed on input and output
files and the printer. In addition,
three off-line programs are In-
cluded with the package that
will allow one to edit PIX files
with the standard HDOS text
editor, and automatically com-
press and expand those FIX
flies to conserve disk space. PIX
files received over the air are ac-
tually compressed before they
are written to disk, and com-
pressed PIX files on disk that
are read for transmission are
automatically expanded by the
system at transmit tfme!

In addition to the unlimited
disk file capability, there are
three temporary single-line buf-
fers that can be loaded and read
out using the three colored func-
tion keys on the H89/H19
keyboard. These are handy for
holding cails of current stations
in QSO or repetitive contest in-
formation. Other function keys
can be used to rnsert the current
date and/or time in the transmit
buffer. (The time of day is also
always maintained on the split-
screen bar.)

In operation, the TX or TXF
commands will put the system
in transmit mode, and a
CONTROLC will terminate the
transmit mode. Data can be
entered into the transmit buffer
while in receive mode, and that
data will be transmitted the next
time TX (transmit) mode Is
entered. TXF (transmit fast), on
the other hand, will not send the
data in tl^e transmit buffer, but
will only send data keyed from
the keyljoard. TXF, therefore, is
used to answer a quick question

or to send a quick message
without sending the data In the
transmit buffer. After TXF, more
data can be entered Into the
transmit buffer, if desired.

Disk-based commands in-
clude opening and cfosing disk
tiles for either read or write,
displaying directories^ deleting
files, exchanging files, and
swapping disks in drives 1 and 2.

Performance

The RT-BS system has per-
formed very well for more than a
year of operation on both the HF
and VHF bands. The system
was designed to support Navy
MARS message traffic as well
as amateur traffic, and has now
replaced all mechanical
teletype equipment at Navy
MARS stations NNN0AFL and
NNNOZVW. No system prob-
lems or failures have yet been
encountered at either station.

The system includes com-
plete operational documenta*
tron and directions for inierfac-
ing the computer to a terminal
unit. The system has been suc-
cessfully interfaced with a HAL
ST-B, commercial and home-
brew Flesher TU'170s» and the
IRbSOO. The iRL-500 interface
was the easiest to accomplish
since it already had inputs and
outputs to directly interface to
the computer at RS-232 voltage
levels.

Each RT-89 system is per-
sonally generated for each pur-
chaser to include the station
callsign. This callsign is per-
manently displayed on the split-
screen bar during system opera-
tion and is used In generating
the CW identification. Minimum
hardware requirements are an
HStwith an H19 terminal) or HS9
computer, a single disk drive,
and 48K memory. HDOS is also
required to operate the system.
The package consists of the pro-
grams on a 5V4" diskette and an
instruction manual. The cost Is
S39.95, For further information,

contact DFD Systems, 4W5 N.

107th Street, Omaha NE 68134.
Reader Service number 477.

Dick Jugel K9DG
8014 Taylor Circle

Omaha NE

INTERFERENCE HANDBOOK

Whether the alphabet-soup
nomenclature Is TVI, RFI, or
EMI, interference is a constant
threat to the radio amateur, lurk-
ing in the shadows, waiting to

Magazine • February, 1982 119

turn docile neighbors into a
horde of angry enemies. Even
though tue war against interfer
ence has just tegun, there is
hope tor the ham-radio army-
Radio Publications' new book.
Interference Handbook, is des-
tined to become a biUe for the
tactlcs-mmded foot soldier. The
author of interference Hand-
book knows what he is talking
about; William Nel&on WA6FQG
is the veteran of sixteen years of
trench warfare as an RFI in-
vestigator for Southern Califor-
nia Edison Company.

RFi has plagued us ever since
Marconi made his first transmis-
sions nearly a century ago.
While moderfi'day legislators
and manufacturers grapple over

a long-term sofutfon, the prob-
lem gets worse and the poor
radio amateur is caught in the
middle. The approach that fn-
terference Handbook takes is
best summarized by the quote:
'The purpose of this handbook
is to Dutime the many sources of
Interference; explain how to
eliminate or reduce them; and
tell you how to protect yourself
against RFI. The causes and
cures of RFI are discussed in
nontechnical language that Is
easy to read and understand."

The topics discussed range
from interference caused by
home appliances and the RFI
emitted by power lines to the
misunderstood role that hams
and CBers play in causing and

solving Interference problems.
Along the way. the author gives
case histories based on his
years as an investigator.

Tips for locating interference
with inexpensive gear are ac-
companied by descriptions of
commercial and homemade
cures. The contents will be ot in-
terest to anyone who deals with
electronics. This could include
the members of a radio club In^
terference committee or a music
lover who is plagued with auto-
mobile ignition noise. The t>ook
is rounded out with a listing of
addresses for gaining help from
manufacturers.

Interference can work t)cth
ways as evidenced by recent ex-
periences at the 73 Magazine

ham shack; Several months ago,
a pulsating noise of unknown
origin kept us bewildered (and
off the air) for several weeks.
More recent ly» a neighbor has
complamed abouX TVI that may
be the result of our station. In
both of these cases, a volume
like the 247-page Interference
Handbook would have helped to
reduce the mystery and ag-
gravation for everyone involved.
A paperback edition of In-
terference Handbook is
available from the publisher^
Radio Publications, Box J49,
Wifton CT 06397, or 73's Radio
Bookshof}, Peterborough NH
03455.

Tim Daniel N8RK
73 Magazine Staff

LETTERS

[

QRZ CONTEST?

The weekend is here, I canl
wait to get my cup of coffee, go
downstairs and turn on the rig,
and relax with some CW.
Cranked up the old workhorse,
my TR4'C, switched on the
keyer. I love CW. my phase of en-
joying ham radio, and spend
most of the time on 20 meters
and a little on 40 meters.

Here comes the audio, and
what? Not again! The entire
band loaded! Another contest? I
thought they just finished one;
you know how time flies, t must
admit I have l^een in only one
con lest, in the early 60s, and
cannot rememt>er what it was
for, but learned it was not for
me. There are no redeeming fac-
tors in them that I can see. A
field day or emergency prepar-
edness operation so as to be
able to get a station on the air
fast in almost any location, por-
tabie, of course, to assist those
in need of help, I am all for with-
out exception, but to sit for 1 2 or
24 hours at a key or a micro-
phone cau^ng a traffic jam
worse than the California free-
ways ever saw is a gross waste
of time and energy.

I enjoy a good rag chew— or
at least to find out more than a
QTH and a name that's in the
Ca//i)0O/r— talking over your ex*
perienceSt experiments, good or

bad. is a greater way to enjoy
one*s on-air time.

Let's think about it; contest
weekend as it appears to me
seems to relate itself to the
opening of hunting season, the
night before everyone partici-
pating making final prepara-
tions, checking their '*guns" for
the big day. From cannons to
peashooters they are all ready.
The clock is ticking away the
last few minutes before the ac-
tion begins. The beams are
poised at each other, power sup-
plies humming away, fingers be-
gin twitching, one ready to
send, one ready to record the
contacts, then bang! A solid
wail of rf rips through the ether
and for the next day the battle
for t he climb to the top rages on.
Stepping on each other, over,
under, and around. When Ihe
period of time for the contest is
over and the electromagnetic
radiations clear, the battlefiled
can be seen strewn with broken
and mangled coffee cups, smok-
ing ballpoint pens, splinters of
pencils, and scraps ot paper.
The casualties are entering the
''hospitals'' with keyer finger,
tennis wrist, another fomn of
keyer finger, and ear-ring: a new
one, being a depression in a cir-
cular fashion around both ears,
manifested by a constant series
of tone bursts that won't
subside.

Why so many contests?

ArenM there enough awards to
be gotten on one's own without
the additional promotion of con-
test after contest? I wouid like
someone to reply and let me
know.

Mow don't get me wrong. I
have gotten a few of those
symptoms myself. What I am
trying lo say is those who prefer
contests are good hams, they
enjoy their phase of ham radio, a
great hobby filled with very nice
people. But all 1 ask for us m the
apparent minority is that on
those special weekends, those
who sanction such contests
tfiink, think of the other hams
who are not participating and
leave at least 10 or 15 kHz aside
for those of us who would like to
just get on and relax with a good
QSO, be it CW or SSB.

Why should the bands be to*
tally monopolized during these
periods? A toi of us just do not
have the time to spend on the
bands and really look forward to
our weekend operation.

Gary L. Jackson N2ACX

Delron NJ

N2ACX UR 599 Nh DE WB8BTH
BK.

THANK YOU, ERIC

As a subscriber, I feel it is my

duty to inform you of the good
job you are doing. I am a new
subscriber to your magazine
and I love it I I am 13 years old
and a General class ham. My fa-
ther is also a ham and he likes
your magazine, too. Between my
father and I we receive GST.
Ham Radio, CO. 73, and CVRA-

SERA Journal We enjoy your
magazine the best. The $25 is
well worth it. I find many inter-
estlng articles In your magazine.
In QST, Ham Radio, and CO f
rarely find a really good article.
Many times the advertisements
are the best things in QST\ I
can't say QST Is a bad maga-
zine— it has many important ref-
erences. The other magazine
(journal), CVRASERA Journal,
is a great magazine. I find it and
73 the most interesting.

Thank you for your time, I just
wanted to tell you how great
your magazine fs. Keep up the
good workl

Eric Lasslter KA4KEG
Danville VA

WIN SOME. LOSE SOM

The last of the ham radio
pubtrshers bit the dust! I never

thought you would pass us off
for the quack electronics, but
my new Decemt>er issue with
satellite TV, computer scanners,
and all really opened the oid
eyes. I think Til go back to model
trains. I get enough of the elec-
tronic garbage at work all day.
NO renewal for me next spring.

Ed Chenoweth K4HYG
Zephyrtiills FL

Sorry to fose you, Ed. but we do
have to bang news of what is
happening in electronics to
those amateurs who are helping

the hobby to grow, . . who are in-
terested m things beyond spark
gaps, t realtze that not all hams
are going to be inventing and
pioneering new techniques, bat

120 73Magaiine • February, t982

/ had hoped that those who are
more interested in takmg a free
ride on the shoulders of those
who are doing the work would at
feast be honorable enough to
read about It and cheer them on
instead of frying to shoot them
down.^Wayne,

Seldom do I write to the editor
of a magazine, but every once in
a WfhIJe something will catch my
eye. Such was the case when
you asked in the October 73
Magazine what we could do to
spur the growth of ham radio.

Let me state that I am flatly
opposed to no-code licenses.
We already have them m the
form of citizens band commun-
ications (I use the word "com-
munications" with some res-
ervation in this case), and I
for one don1 want 15-meter
phone sounding Hke that. J really
can't imagine that you do efther.
Now to the basic question:
What can we do?

1. We can exert pressure on
the Federal Commuoicallons
Commissfon through our elect-
ed representatives to take the
tricks out of amateur exams. For
exampfe, a friend recently took
(and passed) the Extra class ex^
amination in Boston. Part of
his code proficiency test m-
volved the apparent word
"Sprfngfieid," but on the tape
II was sent '^Cprlngfield," Grant*
ed, this qufckie will determine
If the examinee Is paying abso-
lute attention, but does it
prove anything else? Is this the
type of thing one would encoun-
ter in a normal QSO (which the
tape is supposed to emulate)? f
think not.

Z We can stop regarding our-
selves as an elitist group. While
my previous reference to citi-
zens band could be construed
as elitist— and perhaps It Is—
we must recognize that our hob-
by is no better than that of any^
one else. If a CBef wants to be a
CBer, then so be it. If an audio-
ph//e gets enjoyment from his
"things' then (et him. We should
not continue with the attitude
that everyone in electronics
either should ^'progress" inlo
the ham fraternity or be rele-
gated to second class. Perhaps
if we are less pushy more people
would want to join us.

3. Along the same lines, we
should make more of an effort to
help the newcomer. We spend a

lot of time and effort getting
people into ham radio through
Novice classes, but how many
Novices have given up on our
hobby because the Techs, Gen-
erals, Adva needs, and Extras
were too busy with their own in^
terests to give a hand after the
newcomer got that much-antici-
pated ticket? If youVe not really
sure of what youVe doing and
there's no one to help, amateur
radio can be pretty confusing.
Take the time to help a Novice;
you may be saving tomorrow's
Extra class licensee,

4. Again, along the elitist line,
we need to have more of those
'in the know" willing to make
what they know readily avails
able. It does not seem consis-
tent to this writer that an editor
of a widely-read ham publica^
tion could advocate the spread
of our hobby on the one hand
and then ask $1,000 or more tor
a speaking engagement at a
hamfest on the other. Granted,
Dayton and Birmingham can
probably afford this tariff, but
Windsor (our local hamfest)
can't, and Windsor is more likely
to touch a greater number of
new and prospective hams in
central Maine than are Dayton
and Birmingham combined.
Please don't take this as a per*
sonal attack, Wayne, but you did
ask for constructive ideas.

5. We need more affordable
equipment designed for begin-
ning amateurs. Unfortunately,
our hobby is pricing itself out of
the reach of many would-be
joiners because they can't af-
ford a Kenwood TS-530, an loom
720A, or an Astro T50. What we
need are more Ten-Tec Century
21s thai lei the little guy get his
feet wet with new (a Novice
doesn't need the problems
which often come with used
gear), reasonably priced, and ef-
fective equipment.

6. Finally — for now, at
least— we need effective repre-
sentation in the FCC. Some
government commissions are
required to reflect in their mem-
bership the interests of those
that ihey regulate. Why not a
ham as a required commission-
er, and a CBer, too? Who knows
better what we want than one of
our own? Certarnfy not some
politician from the "in" party
who had the misfortune of los-
ing in the last election.

and different fdeas. I wouldn't
even object if theirs were better.

BiflCrowtey K1NIT
Ha Howell ME

No offense. Biff; the $1,000 goes
for a special fund for promoting
amateur radio, not into the gen-
eral coffers. Without that limita-
tion rve found that i am getting
dozens of invitations to taik.
few of which would be possitle
for me. Thus, this is a fil-
ter, . . and also a benefit for am-
ateur radio. You're right about
the tricky exams, . . there is no
excuse for them. There wilt be
cheaper ham gear for beginners
when we have enough begin-
ners to make it profitable to
make the stuff. Remember that
plenty of equipment has been
put on the market in the past,
but it has not been continued
due to an almost total lack of
newcomers. And took what hap^
pened to the newcomer maga-
iine. Ham Horizons]- Wayne

THE HEATH SNOOZE

' have just finished the con-
version of my Heathkit clock as
stated in the November issue of
73 h4agazine ("Extra Accuracy
for Heathkit Clocks," page 124).
There were no conversion or
cross-reference fists at any of
the local Radio Shack stores for
a switch with part number 275-
430. f could have used another
RS switch, but keeping with
amateur radio practice I quickly
realized that the Alarm Set
Switch (SW3) could be used and
the oid Snooze Alarm Switch
(SW2) wired in Its place. It Is a (it-
tie cumbersome to use fn set-
ting the alarm, but then I don't
use this function. My clock
works as stated in the article.

The wiring is done in the same
manner as Art N5AEN stated,
and the new SW3 is wired as
shown in the clock manual

Others may be Interested in
this miser's scheme to beat
down the rising cost of ham
radio.

rve enjoyed 73 hAagazine and
will continue to do so.

Jack Gamar KB7HH
Phoenfx AZ

cjally interested In the radar
devices you use and test. My
mobile friends tell me the de-
vices are not very good any-
more. The policeman with the
gun pops It on and gets a read-
ing and you are hooked. No
more carrier to seek out. I don't
travel much anymore, but I do
have a new approach to traffic
tickets.

I propose a tape-deck player
and a speciaJfy^prepared deck
that starts with fifteen seconds
of sofi music. an<^ men a con-
vincing commercial announcer
who breaks in with the news
that the USA is being attacked
by USSR missiles and the Presi-
dent is on his way by helicopter
to the Virginia underground
shelter. . .all citizens are to go
to any nearby shelter. News
flashes give reports of missiles
twenty minutes from Chicago,
Detroit, Washington,,,

I think by this time the trooper
IS on his way and you are free to
go to your destination.

Just don't get stopped by the
same guy the second tima

£d Kirchhuber K4JK
Elkmont AL

Fiendish. .J like iff The radar
gun? I've only run into one once
in New Hampshire so far, so it
isn*t much of a problem here, fn
that case, / got plenty of warn-
ing before I even got close due
to the sensitivity of the superhet
detector and was safely not
transmitting on two meters
when I went through the check
point. Your detector should pick
it up a half-mile to a mile away
and give you plenty of warning
to stop transmitting so you
won t rack up a speeding ticket
even when you are moseymg
atong at 55 per. The officer gen-
eratfy takes a shot at a car
ahead of you and you pick up
that blast. This also gives you a
chance to check your speed,
which averages around 70 mph
on most of our interstates.—
Wayne,

Well, Wayne, there you have
it. I hope this letter will prompt
others to put on their thinking
caps and come up with more

When 1 read QST, j first look at
the silent keys. With your 73, I
read the editorial I was espe-

Those of you who have been
around ham radio for more than
a few years undoubtedly remem-
ber Gus Browning's fabulous
OXpedittons of the 50s and early
60s. Welt, W4BPD is back at it
again and will be sending us
monthly reports on the progress
of his current round-the-world
trip. Welcome aboard 73, Gus!

73 Magazine • February, 1982 121

This ifttle episode is being
written while we are at anchor
down in Florida awaiting a few
minor repairs to be completed
on the boat, but by the time you
read H we will be somewhere in
the Caribbean. We have named
the ship DX since DX is what it's
all about with us. Our mail ad-
dress from now until this trip is
completed is just "DX, 29039.
USA/'

A friend of mine talked with
me up at DXPO 80 last Septem-
ber and asked mo the question,
'*Have you ever thought about
another DXpedition, Gus?'*

You know what my answer
was (''I have the time if you have
the money"), and he said that
money was no problem! It ended
up that a boat was purchased
and the old rat race of getting it
shipshape for a real DXpedition
began. The resutt is that here we
are about to take off for the com-
/j/e/e Caribbean tour; we'll goto
every country down there that
we can get permission to oper-
ate from. (They tell me that 11-
censing is no problem at almost
every one of them.)

This feller Wayne Green must
have lots of pull somewhere be-
cause both on our way from An-
napolis to Beaufort, South
Carolina, and then again from
Beaufort down here, I saw a sign
on the Inland Waterway on the
left side each time with the num-
bers 73 on a green background.
And this Wayne Green don't fool
around, neither, because when I
mentioned writing a series of
letters for 73 Magazine, he said,
'^Don't stand there, start
writing." So here I am doing just
that.

This DXpedition should be
considerably different from the
others I have been on. This Is
planned to be an island-hoppmg
DXpedition with inland excur-
sions when it's possible and
worthwhile from a DX viewpoint.
We will be going by the seat of
our pants all the way. This DX-
pedition by boat sure will be a
lot better than the other ways I
have used before, and it sure will
be lots cheaper to charter a ship
than to spend anywhere from
$100 on up per day the way I've
done it many times before.
Since 99% of our traveling will
be sailing, using the wind for
power, it will be very interesting
to see how our overall expenses
compare with those of trips
when other means of transpor-
tation were used.

The purpose of the first por-

tion of this trip will be twofold:
We will be shaking down the
boat and we will be trying to see
how we get along with each
other being cooped up over long
periods of time in a small space.
There are three of us— myself,
my XYL, Peggy, and Sam, a WA3
from the Washington DC area
who purchased the boat. So far
we are quite compatible, though
at times a little touchy with
each other, which we all
expected before we ever got
started.

Our tentative plans are to
cover the Caribbean, probably
taking until the next hurricane
season, which starts next June.
Then we will sail back to Beau-
fort to have the boat gone over
with a fine-tooth comb and to
visit all the grandchildren, the
kids, and our friends. We'll
restock the boat's larder, tight-
en up all the bolts and nuts,
and then take off for the Pana-
ma Canal, the big, wide Pa-
cific, and all those countries out
there waiting for us to Dxpedite.
If things are still "go," then we
will continue on around the
world, hitting as many spots as
we can along our line of travel.
We won't mind deviating from
this line of travel a few hundred
miles when, from a DX view-
point, it looks like that's what we
should do.

The very first thing we all
agreed upon was that we
wanted this trip to be a safe one.
Since we have no set date to be
anywhere along our route, we
can always wait for the weather
to get right before we depart
from spot A to go to spot B. If all
three of us like a certain place
and want to spend a few more
days or even weeks there, we
willdojustthat.Thiswill more or
less be a leisure trip with DXpe-
ditioning a first priority on our
list. Right now, we are at the
creeping stage; we hope to be at
the walking stage when I write
the next installment, and at the
running stage from there on out.

We have a very good ship, an
O'Day 37 (measuring 37 feet
long and 11 feet across). How
would you like to make some-
thing like this your complete
home for up to five years? It will
be on the rough side, but we will
be in there trying our best to
stick it out. Our ship is fully
equipped with all the very latest
gear We have a satellite naviga-
tor that does a better job of pin-
pointing our position than most
maps, We have a good radio

direction finder^ a good VHF
transceiver, and, of course, a
sextantp which I have practiced
on for months. I still need more
practice to get good on It. We
have a huge pile of maps and
charts but will need many more
when we get to the Pacific and
other oceans on our way around
the world.

We will be taking it easy along
the way and hamming as much
as possible. We plan to use both
CW and SSB on equal terms, go-
ing by the apparent needs of the
fellows. We have the full Ten-
Tec line of gear, their Omni-C,
Hercules linear, electronic key-
er, and antenna tuner for the
long wires we may put up for the
low bands. I cannot get over the
Ten-Tec's fast break-in, the no
tuning when you change bands,
and the almost silent receiver
when you disconnect the anten-
na. As a back-up, we have Ten-
Tec's Delta. Our antenna is a
TET and it will get a real test of
endurance on this trip. As you
can see, we're delighted with
the equipment we have.

QSLs will go out three dif^
ferent ways. When we have time
after the trip, every QSO in the
logs will go out via bureaus. The
second way of QSLing will be
direct to those who send their
cards to out "DX 29039 USA"
headquarters and contribute
$1.00 to help us defray the cost
of QSLs, postage, and Girl Fri-
day making them out. The third
method will be direct from the
spot where we work you or, if
necessary, from the next spot
we operate, to those making a
$2.00 contribution to help us
with expenses. (We do not ex-
pect to come anywhere near
breaking even on our expenses.)

I don't think we can help any^
one with 300 or more countries,
but we might be able to help you
if you have 200 or so. Maybe we
will help some of you on 40, 80.
or 160 meters. Later on we may
use other means and ways of

communications. We are* of
course, open to your sugges-
tions. We may or may not follow
them, but '1ry us"— hi.

On CW, look for us 25 kHz
from the low end, except on 160,
80, and maybe even 40. On SSB,
when we are not under FCC
rules, we will try using more or
less these frequencies: 28490,
21190, 14105, 7090, 3790 kHz;
and on 160— who knows, hi- But
once we settle down on the ir^
quencles we want to use, these
will be where we will always be
founds plus or minus QRM. I can
promise you I wiil never get mad
at anyone on the entire trip. A
real nuisance to us may have a
difficult job getting our OSL for
his contact— the last laugh will
be us doing the laughing, hi.

Up to now, there has been
very little contributing or donat-
ing by anyone, so I am under
obligation to just a few and I
know who they are. I don't mind
tail-enders or any other way you
can come up with to get your
call in my log, I try to work the
weak ones first, so if you are
QRO please go QRP if you want
to work us first, hi. At times we
will QSY into the Novice bands
and will usually be tuning in the
parts of the band Generals can
use. But you had better have
wide shift-split capabilities, or
you may miss us. Occasionally,
we will use transceive, but don't
depend on this mode for many
contacts with us. I say get your-
self an outboard vfo and join in
with the real DXers.

There will not be any of this
list type of stuff on this DXpedi-
tion—if you want to QSO, get in
there and work me. I don't want
any of this stuff: "Gus^ so and so
said you are Q5-S7"; I want to
hear that report and call myself
without any assistance from
helpers on the sidelines.

That's it for this episode,
fellows— 73 de Gus 8PD.

Gus Browning W4BPD

MM HELP

I am fn need of technlcaf Infor-
mation for the RCA AR88D re-
ceiver. I am also looking for a
24-hour brass ship's clock.

Mickey McOaniel W6FGE

940 Tempie St.

San Diego CA 92106

I am searching for informa-
tion on the use of electric limit
switches with a Tnasto TX-455
crank-up tower.

Don Greenwood KC8GZ
2687 Timothy Place

Wooster OH 44691

122 73Magaifn& • February, 1982

FUN!

John Edwards Kf2U
78-56 Beth Street
GfendafeNY 11385

HAMS AND COMPUTERS

Shh! Keep this quiet! Don't tell anyone, but I think microcom-
puters are taking over amateur radio.

Take last Friday, for instance- I'm working this station on
CW— AF2M, I think the call was— and he's telling me about his rig,
the weather, and all those other things that make QSOs so in-
teresting. Then, alJ of a sudden, something must have blown in his
shack because he just keeps sending "599, 599, 599. . ."After about
10 minutes of having my signal verif ied^ it dawns on me— AF2M is a
machine! Egad! This is worse than CB. At ieast on the chicken band
you pick up animals, not androids.

it's scary. So scary, in fact, that I decided to write a column about
ham radio and microcomputers. Hme it Is but don't tell anyone. I
hate to be an alarmist. Where the heck did 1 put my nightlight?

ELEMENT 1— CROSSWORD PUZZLE
(lllustratian 1)

Across

1 Letters and numerals

8 Below high frequency (abbr.)

9 Direct memory access
(abbr)

10 Computer lingo
13 Package type (abbr.)
15 Operating position
18 line

19 Former big-time computer
manufacturer {abbr.)

20 Program that revises (2
words)

22 And off

23 Data processing (abbr.)
25 Bulletin board (abbr.)

27 Semiconductor type (abbr.)
29GOSUB

■

f?^^

■

Down

i Computer use

2 Scheme

3 Below VHF (abbr.)

4 They bought micro for shut-
tle (abbr.)

5 Statement of condition

6 "Only" type of memory

7 User

11 Crummy software often runs
out of this

12 Golly

14 Instruction

16 To follow immediately

17 Bright diodes (abbr.)
21 Memory type (abbr.)
24 Cycles in a second

26 Smallest computer unit
28 fj

ELEMENT 2-MULTIPLE CHOICE

1) Computers can exchange information by using a code known as
ASCII. What does this acronym stand for?

1. American Standard Code for interchanging

Information

2. American Standard Code for Information

Interchange

3. American Standard Code for Interconnecting

Information

4. American Standard Code II

2) Who was Herman Hollerith?

1. Father of the punch card

2. Father of punched paper tape
3.! Inventor of the floppy disk

4. Inventor of the CRT

3) What are "Napier'^ Bones"?

1. The remains of August Napier, inventor of the

first analog computer

2. The first pocket calculator, named for the

device'3 ivory color

3. A figment of the imagination

4 Ivory rods which, when placed next to each
other, can be used for multiplication
calciiiations

4) An "automaton" is:

1. A mechanism under the constant control of its

own resident intelligence

2. A mechanism under the constant control of a

human or other external inteliigence

3. A mechanism under the constant control of a

programming routine previousiy supplied
by an external inteliigence

4. A waste of time

5) How many laws of robotics did Isaac Asimov detail in his book
I Robots

1. One 2. Two 3. Three 4. Four

ELEMENT 3— TRUE-FALSE

True

False

Illustration 1.

1) HAL, the computer in 2001: A Space
Odyssey, was built at the Hal Plant in
Urbana, Illinois, on January 12, 1997.

2) Speaking of HAL, his name stood for
Heuristically-pfogrammed ALgorith-
mic computer,

3) The word ^' robot" was coined by
Czechoslovakian author Karel Capek
in his play R.U.R.

4) An early electronic computer, ENtAC
(1946), contained 19,000 vacuum
tubes.

5) After ENIAC, there was a computer
caiied MANIAC.

6) PASCAL, the computer language,
was named after Blaise Pascal, a
17th century French philosopher.

7) The ' Computerlst's Code" states
that a computer user should never
use his equipment to harm anyone.

73 Magazine

February, 1982 123

8) BASIC is a high-level language.

9) Bubble memory uses microscopic
magnetic bubbles,

10) CPU stands for "Control Program-
ming Unit,"

READER'S CORNER

Do you have a ham-related puzzle you would like to share with
FUN'S readers? Then send it in for a chance to see your name in
print. This month's contribution is by Joe Strolin K1 REC, of Norwalk,
Connecticut.

ELEMENT 4— HIDDEN WORDS
(Illustration 2)

Hidden in this puzzle are words representing 15 different com-
puter terms. The words are formed In any direction— horizontally,
vertically, or diagonally, forwards or backwards. As you find each
wordj circle it.

MAGtC SQUARE
(Illustration 3)

Circle any number, then cross out all numbers In the same row
and column. Do this until only one number is left, to get the
message.

Send in your answers. We'll print the name and call of everyone
who solved the puzzle.

Z M

A R

A A

lilustration 3.

Iliustration 2.

THE ANSWERS

Element 1:
See Illustration 1A.
Biement 2:
1)— 2, And you know what great stuff American Standard makes.
2)— 1. Ever noticed how these cards are only a little larger than a
dollar bill? That's because HH used the dollar bill of his
time {1890} as the template for his card. He invented the
card and its reader for use in the US census.
3>— 4- Scottish inventor John Napier (1550-1617} developed this
precursor to the slide rule.

ALP

H A

N U Mi

ERIC

pMl

aHo

■ eMo

rIa^H

sId

M aIm

LAN

G U

A GiE

O^^T

0 rHr

1 P^Ia^HeH

0 0 n1

S 0

L EH

eIM

aWe

TEX

D 1 T

nIIm

D P

SIH

BB B

Hi 1

|m 0 S

■■It

■s u

B R

OUT

1 N Ell

Illustration 1A.
124 73Maga2ine • February, 1982

R
P

N O

W R E H (y R A N I

P
O

E
N
A
T
H
R

T I
A S

d) R

L
U
M
N
D
1

T L V A

E S

A/t) D R [ E 1 S S) K

E E

DON

1)A R R

E
A

R
A
H
C
W
O

ilfustration 2A.

4)— 3. 1 is an android, 2 is a robots and 4 is what noting tiie dif-
ferences iS.
S>— 3, And if you break one of the three, you 11 gel a robot fine.
Element 3:

1)— True Long way from the ST-5000, Dr. Chandra.

2)— True Try saying that 10 times, fast.

3(— True Rossum's Universal Robots,

4)— False Ha-ha; sHghtly under IS.CXX).

5)— True Engineers just love snappy acronyms.

6)"True Blaise Pascal (1623-1662), who, after a day of philoso-

phi?fngp would tinker with his adding machine.
7)— False The computerisrs what?
8)— True Afso the most popular, as if you didn't (tnow.
9) — True And if you took through a microscope^ yoLt can even

see them move.
10}— False Central Processing Unit
Efement 4:
See lltustratton 2A.

SCORING

Element 1:

Twenty-five points for the completed puzzle, or Vi point for each

question correctly answered.

Eiement 2:

Five points for each correct answer.

Element 3:

Two and 1/2 points for each correct answer.

Eiement 4:

Two points for each word found.

Are you digitally inclined?

1-20 points— Still mad at the government for outlawing

spark.
points — Thinks computers might have a future,
points— Likes to play with display computers in

stores.
points- Owns a nice, sensible computer system,
points— Home-brews own computer.

21^-40
41-60

61-80
81-100 +

/IIVARDS

Biil Gosn&y KE7C
Micro-80, Inc.
2665 North Busby Road
Oak Harbor WA 98277

WAT AWARD

The Cabin Fever Radio Club
of Tok, Alaska, offers a cer-
tificate for contacting three
amateurs in Tok. There are no
band or mode restrictions.
However, all contacts must be
made after December 15, 1980,
to be considered valid.

To apply, prepare a list of con-
tacts in order by callsign. In-
clude the name of the station
operator, the date and time
worked in GMT, and the mode
and band of operation. OSLs not
required. Amateurs located in
Tok include AL70, AL7B0,
AL7BV. and WL7APG.

Send your application with
$2.00 or 10 IRCs to: Cabin Fever
Radio Cfub. Box 451, Tok AK
99780.

WORKED ALL FORGOTTONtA

Announcing the awards pro-
gram sponsored by LEARC, the
Lamoine Emergency Amateur
Radio Cfub of Macomb, Illinois.
The Worked Forgotten la award
is issued amateurs who confirm
contact with three (3) licensed
amateurs of Forgottonia. The
Worked ALL Forgottonia is
awarded operators confirming
contact with at least one
amateur in each of the sixteen
counties of Forgottonfa.

What is Forgottonia? It is the
51st state! It consists of the
tollowing counties, formerly

a^mimmA^oK

'dBS€0'

wesi central Illinois: Adams,
Brown, Calhoun, Cass, Fulton,
Greene, Hancock, Henderson,
Knox, McDonough, Mercer,
Morgan, Pike, Schuyler, Scott,
and Warren counties.

All contacts must be made
after June 28, 1980. to be valid.
From the letter we received from
the club, the award evidently
is Issued at no charge since no
remittance was mentioned- For-
ward your list of verified
contacts and a 9" x 12" SASE
to the attention, of AG9Y, c/o

LEARC, l224MapleAvenuepMa'
comb IL 61455.

JUNIATA VALLEY

In March, the Juniata Valley
Amateur Radio Club (JVARC>
will be celebrating its 25th year
as a bona fide club. In honor of
the event, they will be operating
a special event station. The club
station Is K3DNA, located in
Lewistown PA {Mjfflfn county).
Having started operation fn
January, %hQ\T heavy operation
is scheduled for the month of

^ <

THiS CiBrffWAfB fS AWARDED tN RfCOGmnON Of SUPfmR DPfBAfm Smi
Am NQ8LE DiD/CATm TO TmmH£ST PmCfPUS OfAmnUH ffADIO.

me REcmmr has QEmmiRATm these AimBms by MAms rm wav MDfo

COmACT WiTH A UCEmEQ AMATim W EACH Of THE SIXT^N COUNTIES Of

^BGOTTQMA, "^*

<?^

OPE/tATOff

£^€

WAHftiH

JJAjM

STATION ^D? X y^L

^ #n>HiJHi1

fOHGOTTOmA ^ THE Stsr STATE Of T^ iMM&i. matm Y WEST C&fTfmL MmOfS

tr WAS fomoED m 1373 wheh the naif Mtam ftESiOfNTS Of THE AREA /minm

rmr wEfiE ommG mAt^i r mFA^ABtE ffOAOS. SEHtom wbr ammm to tmoEfi

ftmED scMtrng Am sEm monEO or Mi iimois officms emceft rm

DEPAffTMmtT iff jRfl^iftM,

73 Magazine • February, 1982 125

March. The station will operate
on different bands, CW and
phone, according to the opera-
tors' wishes. One contact with
any club member wiff efititle the
operator to receive the club cer-
tlficate.

VK1 ACHIEVEMENT AWARD

The A,CT. Divrslorr of the
Wireless Institute of Australia is
proud to announce the creation
of its newest award, the VK1
Achievement Award. This award
has the arm of increasing in^
terest in the VK1 prefix and in
promoting Canberra and Austra-
lia Internationally.

As there are only 300 VK1
licensees, the award will not be
an easy one to achieve, par-
ticularty on some bands and
modes.

The VK1 Award fs available to
licensed amateurs throughout
the world. To qualify, stations
within Australia must work 20
stations in VKt land on HF and
on VHF. Stations outside Aus-
tralia must work a minimum of
10 VK1 stations for the HF seg*
ment of the award.

To apply, submit your list of
contacts,, includmg the GMT
time and date worked, the band

and mode of operation, and any
reports or ciphers exchanged.

To be valid, all contacts must
be made on or after January 1,
1978- Endorsements may be
given at the time appltcalion is
made. Five IRCs or S2.00 fn
Australian currency covers the
cost of the award and should be
sent to the Award Manager, c/o
WIA. PO Box 46. Canberra A,C.T-
2600, Australia.

By the way, the VK1 Award is
also made available to short-
wave listening stations on a
heard basjs. QSL confirmation
is required*

SNOWFLAKE MADNESS

The Michigan Technological
University Amateur Radio Club
and the Copper Country Radio
Amateur Associatbn announce
a radio celebration of our Winter
CarnivaJ festivities in the nor-
thernmost part of Michigan's
Upper Peninsula.

Tech's Wrnter Carnival is
probably the most spectacular
winter festival in America, with
fantastic snow sculptures,
dogsled races, lots of skiing,
and other festive events.

In association with the Cop^
per Country Chamber of Com-
merce, they are issuing a cer-

•«***iMa«am

iwnp«inn^«<aw>Pt#cooecnnnnnmi«ffWM—

N**

M»

**^

.i*S>NSTITOKo,^^

A. c.T. Division
f

^/.

4»

^^/

•< ■»■

Thi^K liii:crlir> tllttt

liiis C4im|i1cli:d lilt: rct|tiiri.iiHn|s

CIIIITKAII NUMIiH

k «n|iii. «%%««« wm« «. viL« ih %'^% 4

PAlt

1NtKltl.|J«ltHit

ni«i,iE»Hf

/^t_, .\

%c^n^%^

■•*••••«

oaammmmmm*m

tificate to all amateurs who
make contact with any ham in
the Copper Country between
OOOOZ January 25 and OOOOZ
February 1, Only one contact is
required for the certificate.

Suggested frequencies are:
3.975. 7.105, T.2S5. and 21.3B5.
Listen for CQ WINTER CAR*
NIVAL

Send your QSL along with 2
(twoj 20-cent stamps to: Kevin J.
Nietzke WDBDQR, 2005D Wood-
mar Drive, Houghton Ml 49931*

WORKED BROWARD
COUNTY CITIES

The Broward Amateur Radio
Club, Inc, sponsors the new
WBCC award available to
licensed amateurs who submit
proof of two'way contact as
fodows:

A) Residents of Broward, Col-
liers, Dade, Glades, Hendry, Lee»
Martin, Monroe, or Palm Beach
counties must work all 29 of the
following cities listed below.

B) All other amateurs must
work 15 of the 29 cities within
Broward county.

To t>e valid, all contacts must
be verified by at least two fellow
amateurs and application must
show all logbook information as
well as the QTH of the station
worked.

To apply, mall your applica-
tion with $1.00 US funds and

two first-class stamps (DX sta-
tions; send 10 IRGs) to: BARC
Award Manager. WD4RAR 1921
NW 41st Street. Oakland Park
FL 33309.

Qualifying city contacts In-
clude: Coconut Creek, Cooper
City. Coral Springs. Danfa,
Davie, Deerfteld Beach, Fort
Lauderdale, Hacienda Village,
Hallandate, Hillsboro Beach,
Hollywood, Lauderdale-by-the-
Sea« Lauderdale Lakes. Lauder-
hill. Lazy Lake, Lighthouse
Point, Margate, MIramar, North
Lauderdale, Oakland Park,
Parkland, Pembroke Park, Pem-
broke Pines, Plantation, Pom-
pano Beach, Sea Ranch Lakes,
Sunrise, Tamarac, and Wilton
Manors.

THE SOUTH EAST

QUEENSLAND TELETYPE

GROUP AWARD

This award is open to all
transmitting and listening

amateurs who gain award
points m the following manner

Australian amateurs must
score 5 points and overseas
amateurs must score 3 points.

(a) To qualify, a station must,
where possible, copy the official
station of the South East
Queensland Teletype Group,
VK4TTY, during a news broad-
cast and in the case of a
transmitting amateur par-

WBCC

W4>rk€Ht BnnviircJ Cloumy c:itleii

1 4 lljlH I Mh-

I Itr Ht*«^^*iiiL Mil* lit -in Kiiih«* t nui liii

I t'lllllt '^ lli<l1

lui*% srtJiiii|(i|t''H t'Vinf ri' < I M lv\i. \\,i\

1 I If 1 ft ru If IK ^iiinns Willi f triiH m

• is M-ifJ.

l*f«^ii|f-nf

126 TSMagaime • February. 1982

tjcipate in the caJlbaok (2 award
points). A portion of the printoul
of the news broadcast together
with the date, time, frequency,
and broadcast number are to ac^
company the request for the
award.

(b) Addftionaiiy, a transmit-
ting amateur must work three
member stations of the South
East Queensiand Taietype
Group on RTTY (1 point each).
Log extracts and/or printouts
are to be included with the
award application, and each
member station may be counted
only once towards the award.

(c) Listening amateurs should,
in lieu of (b), forward log extracts
and/or printouts of three con-
tacts involving different
member stations of the South
East Queensland Teletype
Group 0 point each).

Applicants for the award
should forward the above infor-
mation together with one dollar
Australian or 5 IPCs to cover
postage and printing costs to
' the Secretary. SEQTG, PO Box
274, Sunnybank; Queensfand
4109. AustraNa.

WORKED ALL
BERMUDA AWARD

The WAB Award is issued to
amateurs throughout the world
by the Radio Society of Ber-
muda. To qualify, applicants
must submit proof of having
worked a minimum of nine (9)
parishes in Bermuda as listed
below:

1. Sandys

2. Southampton
a Warwick

4. Paget

5. Pembroke

6. Devonshire

7. Smith's

8. Hamilton

9. St. George^s

The award is an antique map
of Bermuda {20" x 23") suitably

AU ASfiAtt AHMd

class

This award is given to ^3 Mcn^a-2.ftng_ f^^

establishing two way contacts with radio
amateur stations in ntentber countries of the
ASEAN namely; indonesiat Malaysia, Singa^
pore, Thailand^ and the Philippines,

Awarded Man^ js, /*ao by the ORIENTAL
CLUB, Quezon City, Philippines,

inscribed with the recipient's

name and callsign and Is signed
by His Exceilency, the Governor
of Bemiuda.

The award is not available to
stations who worked Bermuda
via mobile including maritime or
aeronautical mobile. No band or
mode endorsements are
available. Only one mobile or
portable from within Bermuda
may be used in making clatmed
contacts on your application.

QSL cards are required as
proof of contact and they must
be sent to the awards manager
with sufficient postage for their
safe return. The Bermuda Award
is issued free of charge! Submit
your applications to: Award
Manager, PO Box 275, Hamilton
5, Bermuda.

WORKED ALL DU AWARD

This award is availabFe to all
licensed amateurs who can

show proof of having contacted
at least one station from each of
the call areas in the Republic of
the Philippines (DU1 to 0U9, ex-
cept DU5),

Contacts may be made on
any band or mode and special
endorsements will be issued
upon request for All-Phone. AH-
CW. Single-Band, or Five*Band
accomplishments.

Contacts for the DU Award
must be made on or after
January 1, 1970. To apply, for-
ward a list of contacts which
have been verified by two of-
ficers of a radio organization.
Your application must show all
logbook Intormation for each
contact- Send the list and $4.00
US funds only {no IRCs pleasel)
to: Edwin Zambrano DU1EFZ,
PO Box AC-166, Quezon City
3001, Philippines.

WORKED ALL ASEAN AWARD

The WAAA program requires
the applicant to work other

amateurs in the member cpun-
tries of the Association of
Southeast Asian Nations:

Work 5 Philippine contacts, 1
Malaysian contact. 2 Indone-
sian contacts^ 1 in Thailand, and
1 station in Singapore.

Speciaf endorsements will be
given for All-Phone, AII-CW,
Single-Band, and Five-Band
contacts.

Have your list of contacts
verified by at least two radio
club officials and be sure all
contacts were made after Jan-
uary 1, 1970, to be valid. Forward
appropriate logbook informa-
tion in your application along
with $4,00 US funds only (no
IRCs) to the Award Manager: Ed-
win Zambrano DU1EFZ, PO Box
AC-166, Quezon City 3001,
Philippines,

KAHANER REPORT

Larry Kahaner WB2NEL
PO Box 39103
Washington 00 20016

By now you probably know
that the FCC gave up m its at-
tempt to rewrite the Amateur

Radio Service roles. After
spending thousands of dollars
and consuming thousands of
man-hours, the whole Idea was
thrown in the trash compactor.
We may never learn exactly
what led to the shelving of the

massive revamp nor will we ever ponents caUed the rewrite overly

realize any t>enefit from all that
work. However, several FCC em-
ployees said privately what we
all know intuitively about
the project: It was just too big
and too complicated to be
completed.

You must admit the main
premise was sound. Whenever a
government agency wants to
put its roles Into plain English,
we should all support it. tn this
case^ it went a little too far. Op-

simplistic and said that many of
the fine points of amateur radio
were lost In the translation. They
also claimed that the question
and answer format— which
worked so well for the rewritten
CB rules— just didn't work for
hams. Amateurs, they declared,
were intelligent and took of-
fense at the condescending
stance of Q & A.

Moreover, the bulk of hams
who responded to the petition

73 Magazine • February J982 127

for rulemakmg took umbrage at
the very beginning of the rewrite
proposal which dropped the fa-
mous reasons for amateurs' ex-
istence: promoting international
goodwill, experimentation, and
50 on.

FCC otflcials told us that the
rewrite contained many errors
and mistakes—not just typos,
but in substance as welL And ah
though FCC proposals always
contain errors, in this case it
would have been just too much
work to set things right. Normal-
ly, the commission works with
opponents and proponents alike
until the regulations are honed
to where everyone can live with
them. But for the ham rewrite,
there was too much to do, too
few staff to do it, and no funds
available to keep the project
alive.

On one hand, the FCC should
be applauded for realizing that it
would take resources beyond its

means to complete the task and
dropping it now before any more
lime and money was wasted. On
the other hand, perhaps the
commission should be scolded
for even beginning a course of
action that came under fire from
hams at the onset. Even those in
the commission ej^pressed
doubts as to whether it was nec-
essary to rewrite the rules. It's
certainly apparent that much of
the impetus for change was po-
litical (see Kahaner Report,
September, 1981), Thai should
never be a reason for a govern-
ment agency to do anything
with taxpayers' money.

So, it seems that hams fought
the measure and won. But the
question arises—who lost?

OUR OWN CHANNEL 9

Paul Moratto KC5Jig6. from

Universal City CA, mailed the
FCC a petition for rulemaking re*

questing that 11 destgnate a par-
ticular 2m frequency to be used
exclusively as an emergency
and assistance channef. Paul
also sent us the petition asking
for our comment. Here goes.

It's a great idea» Paul, but It's
not necessary. Hams donl need
the FCC to set aside a special
channel for emergency use.
Hams can do it on their own.

If hams can set up a national
simplex channel {.52) and work
out an entire repeater coordina-
tion scheme which only tew
hams don't adhere to. they can
certainly decide for themselves
if they want one frequency des*
ignated for emergency and as-
sistance useonty.

In his petHion, Paul noted:
*'Various law enforcement offl*
cials have stated that the
2-meter amateur band is rarely
monitored due to that fact that
no Bmergency frequency has
been officially designated ex^

closively for such communica-
tion/" Frankly. Paul, I doubt that
police departments would t>e
willing to shell out bucks for a
scanner that would pick up 2
meters or even buy crystals to
place in scanners they may al-
ready own- Indeed, cops have
enough to listen to without
keeping an ear open on another
frequency. If and when ham ra-
dio ranks reach that of CBers,
maybe theyll listen— but right
now it's not worth it.

Besides, even if they heard a
distress call, they couldn't re-
spond unless they were li-
censed hams. Many police are,
but many aren't.

Any hams out there want to
start work on a national emer-
gency channel? Be my guest.
Although I can't answer for the
FCC. I II bet they'll tell Paul ex*
actly what t just tord you: '1f you
want to do it, do it. You don*l
need us."

COHTESTS

Robert Baker W82GFE
15 Windsor Dr.
AtcoNJ 08004

RSGB 7-MHZ CONTESTS

Phone Section

Starts: 1200 GMT February 6

Ends; 0900 GMT February 7

CW Section

Starts: 1200 GMT February 27

Ends: 0900 GMT February 28

Licensed radio amateurs and
listeners throughout the world
are invited to take part in this
year's RSGB contests. Log and
cover sheets may be obtained
from RSGB Headquarters, 35
Doughty Street, London, En-
gland WC1N 2AE. Please In-
dude an SAE.

The general rules for RSGB
HF contests, published in the
January, 1982, issue of Radio

Communication, will apply.
Please note, however, that urv-
marked duplicate contacts will
be penalized at 10 limes the
number of points claimed, and
that logs containing in excess of
5 unmarked duplicate contacts
will automatically be disquali-
fied. Duplicate contacts should
be included in your logs, marked
BB such, and without any claim
for points.

Only RSGB members within
the British Isles are eligible,
while anyone else worldwide
may enter. The only valid
operating class is single
operator.

EXCHANGE:

RS(T) plus serial number
starting at 001.

FBBOUENCtES:

Phone— 7.04 to 7 A MHz; CW
—7,00 to 7 04 MHz.

SCORING:

Non-European stations with
British Isles count ^5 points per
QSO. European stations wtth
British Isles count 5 points per
QSO. British Isles stations with
European stations count 5
points per QSO, 15 points per
non-European contact. British

Isles stations may not work
each other.

Multiplier for British Isles sta-
tions is the number of different
countries worked— ARRL DXCC
list applies. In addition, each VE,
VK. W, ZL, and ZS call area
counts as a country for this
purpiose.

Non-British Isles stations
count one multiplier for each dif-
ferent British Isles prefix worked,

maximum of 42. Please note
that GB does not count!

Final score for all is QSO
points times the total multiplier,

AWARDS:

The Thomas (G6QB) Memorial
Trophy will be awarded to the
leading British Isles entrant in
the CW contest. Certificates will
be sent to the entrants placed
first, second, and third in the
British IsleSp European, and non-

Feb $.7
Feb 6-7
Feb S*7
Feb 13-14
Feb 1314
Feb 20-21
Feb 26 28
Feb 2728
Mar 6-7
Mar 13-14
Apr 17^18
Jun 12-13
4un 26 27
Jul 10*11
Aug 7*8
Aug 14-15
S«p 11-12
Sep 11 12
Nov 6-7
Nov 13-14
Nov 20*21
Dec 4-5
Dec1M2

MLENMR

RSGB 7 MHz Contest— Phone

South Camftna QSO Party

Arizona QSO Party

WAS SSTV Contest

QCWA QSO Party -CW

ARRL DX Contest— CW

CO Worldwide 16{)*Meter Contest— SSB

RSGB T-MHz Contest— CW

ARRL DX Contest— Phone

QCWA QSO Party— Phone

ARCI QRP Spring QSO Party

ARRL VHF QSO Party

ARRL Field Day

lARU Radiosport

ARRL UHF Contest

European DX Contest— CW

ARRL VHF QSO Party

European DX Contest— Phone

ARRL Sweepstakes— CW

European DX Contest— RTTY

ARRL Sweepstakes— -Phone
ARRL IBO-Meter Contest
ARRL 10 Meter Contest

12fl 73 Magazine • February, 1982

European sections of each
contest.

ENTRIES:

Log sheets should be headed;
date, time (GMT), callsigrr of sta-
tion worked, RS(T) and number
sent, RS(T)and number received,
if muJtipJJer, and QSO points
claimed. A summary sheet is re-
quired showing the countries or
prefixes worked. Each log must
be accompanied by the follow-
ing declaration: "I declare that
my station was operated in ac-
cordance with the rules of the
contest and in accordance with
the terms of my license." The
declaration must be signed and
dated. Closing date for receipt
of logs Is April 3rd for the phone
section and April 24th for the
CW section. Address entries to:
RSGB HF Contests Committee,
PO Box 73, Lichfield, Stafford-
shire WS13 6UJ England. In the
case of any dispute, the ruling of
the Council of the RSGB shall be
final.

RECEIVING SECTION:

Rules are generally the same,
as applicable, British Isles en-
trants should fog only overseas
stations in contact with British
Isles stations and must record
the report and serial number
given by the overseas station
and the time in GMT. European
stations logged count 5 points;
outside Europe, 15 points. No
more than 20 QSOs made by any
one British Isfes station may be
fogged.

Overseas listeners should log
British Isles stations and must
record the reports and serial
numbers given and the time in
GMT. European listeners claim 5
points per QSO togged; others,
15. A bonus of 20 points may be
ciaimed for each British Isles
numerfcal prefix logged. GB
prefixes do not count, and not
more than 20 QSOs made by the
same British station may be
fogged.

ARIZONA QSO PARTY

Starts: 20C0 GMT February 6
Ends: OaOO GMT February 7

Sponsored by the Arizona
Amateur Radio Club. Each sta-
tion may be worked only once
per band.

EXCHANGE:

BS(T) and state, province,
country, or AZ county.

FREQUENCfES:

SSB — 1815, 3895, 7230,
14280, 21365, 28560, CW— 1805,
3560, 7060, 14060, 21060, 28060.
Novice — 3725, 7125, 21125,
28125.

SCORING:

Count 1 point per SSB QSO
and 2 points for each CW or "ex-
otic" mode QSO. AZ stations
multiply QSO points by number
of states, provinces, and coun-
tries. Others multiply QSO
points by number of AZ coun-
ties. The AARC club station
W7I0 also counts as 1 multiplier
for non-AZ stations. Anyone
working all AZ counties and
W7I0 may double the multiplier.

AWARDS:

Certificates for the highest
scoring station in each state,
province, country, and AZ
county.

ENTRIES:

Show each station worked,
RST and exchange, plus time
and frequency. Include a sum-
mary sheet of your scoring and
other information, Include a
large SASE for results. Mailing
deadline Is March 6th and
should be addressed to: AARC,
c/o Gary Kent KB7VE, 16647 N.
34th Avenue, Phoenix AZ 85023.

SOUTH CAROLINA QSO PARTY

Starts: 1800 GMT February 6
Ends: 2359 GMT February 7

The QSO party is again spon-
sored by the Colleton County
Contestofs. The same station
may be worked on each band
and mode, simplex only. SC
mobile stations that change
counties are considered new
stations* Novice and Technician
stations please sign IH or U,

EXCHANGE:

RS(T) and state, province,
country, or SC county.

SCORING:

Phone contacts are worth 2
QSO points, CW contacts are
worth 3 points. The multiplier for
SC stations is the number of
states, provinces, and DX coun-
tries worked. Others multiply
QSO points by the number of SC
counties worked (46 maximumj.

FREQUENCIES:

Phone~3895, 7230, 14280,
21365, 28560. CW— 3560, 7060,
14060, 21060, 28060. Novice—
3725, 7125,21125,28125.

REmJS

RESULTS OF THE 1931 OHIO QSO PARTY

Ohio

KA2EPS

ENY

5,550

Stations

Score

K9GDF

4,008

WB8M77

1,501,640

W2EZ

WNY

3,900

KB8EI

820,155

KA8LPV

3,810

WBSJBM

666,000

K8EIO/3

MD/DC

3,430

WDSALG

448,707

N04P

3,360

KA8HXX

428,736

WB3IET

WPA

3,240

KC8JH

339,000

W40VT

2,940

KFBK

206,550

WB4ZPF

2,875

N8AKF

163.674

NOCLV

2,314

KASIAH

1 48,830

N1BDB

2,180

KA8CTL

104,636

W4KM3

1,692

KB8AC

100,940

WB3FNS

MD/DC

1,628

N8JJ

47,120

N4CD

1,552

W8DXT

45,628

KG9Z

1,482

WA8WFX

39,285

WB9CWE

1,364

WD8MC0

33,178

WA3JXW

E PA

1,232

KB8WB

31,820

WA3GNW

EPA

828

KA8IGM

31,620

WB9NRK

780

WB8MIP

28,968

K2NC

W NY

737

W8HFK

26,048

WBIGLH

672

NBDCJ

23,408

W4LEP

588

N8BJQ

12,810

WA9MRU

676

W80JM

3,335

WB7TJI

351

W8VPV (CI I

lb Station)

KA1VE

340

183,012

N5AFV

306

KA2EG0

N NJ

208

Out of

AK7J

165

State

Score

KF2T

NNJ

132

WAeAVU9

IL 11,086

KB9Ti

W4F0A

VA 10,480

K1BV

AWARDS:

made with

"caotive"

stations.

Certfficates to top scoring
station in eacti SC county, state,
province, and DX country. Nov-
ices and Tecfinicians compete
only with other Novices and
Technicians,

ENTRIES:

Include a summary sf^eet with
your entry showing scoring and
other information. Indicate each
new multiplier in your log as it is
worked. Novice and Technician
indicate cJass on your entry. In-
clude a large SASE for results.
Mailing deadline is March 5th;
send to: Colleton County Con-
testors, c/o Elliott Farrell, Jr.
WA4YUU, PO Box 994» Walter-
boro SC 29488.

QCWA QSO PARTY-CW

Starts: 0001 GMT February 13
Ends: 2400 GMT February 14

This is the 25th annual QCWA
QSO party with separate week-
ends for CW and phone. Con-
tacts with the same station on
more than one band can be
scored only once. Contacts

such as when operating in local
nets, are not valid.

EXCHANGE:

QSO number, operator's
name, and QCWA chapter iden-
tification (official number or
name). Members not affiliated
with a chapter should use "AL".

FREQUENCIES:

Any authorized amateur fre-
quency is permissible. The fol-
lowing suggested frequencies
have been selected to minimize
rnterference to others: 3530-
3560, 7030-7060, 14030-14060,
21040-21070, and 28040-29070,
These are selected as a starting
piace. When pileups occur,
don't be afraid to go either side
of these frequencies,

SCORING:

Each contact made with an-
other QCWA member win count
as a single point. This year's
contest has two multipliers. The
first is the same as in years past:
each chapter is a multiplier of
one. The second is that DX sta-

73 Magazine * February, 1982 129

QSL OF THE MONTH

Call us chauvinists* but the beautffut rendition of the New Hamp-
shlfe countryside on this attractive card wins WBlGGQ hrs choice
of any book in T3's Radio Bookshop.

Is your card a winner? To enter, place your card in an envelope
along with your book selection and mail to 73 Magazine, Pine Street,
Peterborough NH 03458. Atlention: QSL ot the Month. To be eligible,
your entry must be sent in an envelope and must be accompanie<l by
your book selection.

tions are a multiplier of two. DX
stations are defined as Europe,
Africa. South America, Asia, and
Oceania— the same as for WAC
of ARRL. Contacts within your
own country count oniy as a
chapter multiplier. Final score is
then the total QSO points times
the sum of the number of chap-
ters and DX stations worked.

AWARDS:

Plaques for the top phone and
top CW scorefs. Certificates wilf
be given for the 2nd through 5th
runnerS"Up in both the phone
and CW Parties. Standings and
scores will be published In the
QCWA News, Issue of summer,
1982.

ENTRfES:

Logs should include the fol-
lowing information: lime (GMT),
call QSO numbers* name, chap-
ter number or name, state or
country. It is the responsibility
of each contestant to provide a
legible log, no carbon copies,
and to list alt claimed contacts.

The total contacts for each page
win be recorded at the bottom of
each page. The total contacts
for the Party should be recorded
at the top right of the first page
of the log. Log sheets will not be
returned. Make sure you have
correct postage when you mail
your logs. Send logs no later
than March 31st to: Pine Tree
Chapter 134, Glenn Baxter
K1MAN, Long Pond Lodge, Bel-
grade Lakes ME 0491 8. Separate
logs and scores must be sub-
mitted for the CW and phone
parties,.

Work as many QCWA mem-
bers as possible and appiy for
the severai special QCWA certif-
icates which you have quali-
fied for in the QCWA Parties:
Worked 50 States. Worked 60
Chapters, Worked 100 Mem-
bers» and Worked 500 Members.

WAS SSTV CONTEST

Starts: 0900 EST February 13
Ends: 2100 EST February 14

Sponsored by amateur televi-
sion's A5 Magazine. Use all au-

NEWSLETTER CONTEST WINNER

Humor is a key part of this month's newsletter winner. The
Narional H^mpoon, published by the Cleveland-based South
East Amateur Radio Club, is chock full of puns, good-natured
put*downs, and inside jokes. Editor KA8KTR is not above pok-
ing fun at himself or the 33-year-otd club. Besides being fun to
read. The National Hampoon provides a deluge of information
about what individual club members are doing. Don't lei your
club's members fall into the trap of not reading each newslet*
terTry adding some life and humor; the readers will anxiously
await the arrival of the next issue.

thorized and recognized SSTV
operating frequencies within
the HF bands. Attempt to work
as many SSTV operators from
other states as possible during
the 36-hoyr contest period. The
emphasis is on quality, not just
quantity.

SCORING:

Count 25 points per contact
with 10 bonus points awarded
for live exchanges of "mug-
shots/' color two^way contacts,
or 256 or 128 (t/2-speed) mode
transmissions. Add 100 points
for each new state listed. Alaska
and Hawaii contacts count a
bonus factor ot 500 points!

EXCHANGE:

Station calls and signal re-
ports must be exchanged in vid-
eo format by either camera, key-
board, or light-pen generators.

A WARDS:

First place winnner receives a
S-year subscription (or renewal)
to A5 Magazine, a framed Spe-
cialized Communication Certifi-
cate, and his photo published on
the front cover of the magazine.
Second- and third-place winners
receive 1-year subscriptions and
certificates. All contestants will
receive gold certificates with
submitted logs.

ENTRIES:

Submit actual or copies of
contest log sheets by no later
than March 1st to Contest Man-
ager, A5 Magazine, PQ Box H,
Lowden lA 52255. Official re-
sults will be published In the
May/June issue of AS Magazine.
Those winners attending the
Dayton, Ohio. Hamvention will
be awarded certificates at the
regular ATV Forum meetings.

CO WORLDWIDE 160'METER
CONTEST--SSB

Starts: 2200 GMT February 28
Ends: 1600 GMT February 28

EXCHANGE:

RS plus a three^iglt contact

number starting with 001, US
stations include state and Cana-
dians include province.

SCORiNG:

US and Canadian stations
count 2 points per QSO with
other WA/EA^O stations: DX con-
tacts are 10 points each,

DX stations count 2 points per
QSO with stations in the same
country and 5 points with sta-
tions in other countries. QSOs

with W/vevO stations are 10
points each.

All stations count one multi-
plier point for each US state, VE
province, and OX country. KH6
and KL7 are considered DX. Fi-
nal score is total QSO points
times the sum of multipliers.

AWARDS:

Certificates to the top scorers
in each state, VE province, and
DX country. Additional awards if
the scores or returns warrant.

Two plaques are t>eing award*
ed by the West Gulf ARC. both
for single operators, one for the
highest scoring US station and
the other for Europe. The World
Champion in the contest will
receive the John Doremus
WilAW Memorial Plaque from
friends of WHAW. This plaque
may be won only once by the
same station in a three-year
period.

PENALTfES:

Three additional contacts will
t>e deleted from the score for
each duplicate, false, or unverl-
fiable contact removed from the
log. A second multiplier will also
be removed for each one lost by
this action*

Violation of the rules and reg-
ulations pertaining to amateur
radio in the country of the con-
testant, or the rules of the
contest, or unsportmanship con-
duct, or taking credit for exces-
sive duplicate contacts or multl*
pfiers wiii be deemed sufficient
cause for disqualification. Dts-
qualified stations or operators
may be barred from competing
in CO contests for a period of up
to three years,

ENTRIES:

Sample log and summary
sheets may be obtained from
CQ by sending a large SASE
with sufficient postage to cover
your request. It is not necessary
to use the official form; you can
use your own. Logs should have
40 contacts per page and show
time in GMT. numt)ers sent and
received, and separate columns
for QSO points and multipliers.
Indicate the multiplier only the
first time It is worked*

Mailing deadline for SSB en-
tries is March 31st- Logs can be
sent directly to the 160 Contest
Director, Don McClenon N41N,
3075 Florida Avenue* Melbourne
FL 32901 USA. Alterr^atively.
they can be sent to CQ, 160-
Meter Contest, 76 North Broad-
way. Hicksville NY 11801 USA,

130 73Magazme • February J 982

W2NSD/f

NEVER SAY DIE

ecfitor/a/ t>y Watyne Gr&en

show them around. Have the 450-MH2 band? How about 220

from page 8

*'TWi section shalf not appfy to re*
celvjng, divulging, publishing, or util-
izing the contents of any radio com-
munication whJch Is transmitted by
any station for ihe use ot the general
public: or which refers lo ships, air-
craft, vehicles, or persons in distrets;
or which is monitored pursuant lo
section 4(fK6) and which is received,
divulged, or used In any investiga-
tion or enforcement action by the
Commission."

Explanation

This amendment conforms §605 to
§4<f) to accommodate proposed lan-
guage to permit use of volunteef
monitors.

Here Is another way that ama^

laurs could help the Commis-
sion cut down on their costs.
Not that they are spending a lot
monitoring the ham bands these
days anyway . . . and who needs
*em? But with the rules changed
so that amateurs could set up a
moniloffng system, we would
be able to clean up a lot of
miseries which are now plagu-
ing our bands.

We have tens of thousands of
retired hams and several thou-
sand more handicapped hams,
ail with loads of time on their
hands and an eagerness to be of
value. WelL here is a service thai
these hams could provide which
would be priceless to us. IVe
talked with the FCC commis-
sioners about this and they
seem to be enthusiastic about
the concept. You see. not only
could hams be organized to
monitor the ham bands, but they
could also assist the FCC moni-
tors in watching over some of
the non-amateur bands, too.

If we once started getting into
this monitoring idea, it would
not be long before innovative
hams would start coming up
with automatic bamS scanners
and receivers which would be
connected to microcomputers
and would program themselves
to fisten for unrecognized trans^
missions. With digital receivers
and frequency counters, it is on-
ly one more step to a system
which wiil keep track of what
signals are okay on what fre-

quencies and spot the anoma*
lies quickly so they can be
Identified.

Not onfy would this be of
great help for digging out
emergency signals fast, but it
would be even better protection
against illicit transmissions in-
volved wfth spying and drug traf-
fic and so on. Coded transmis-
sions? We have some mighty
sharp ham cryptographers who
would love to have challenges
like that.

Why should the government
spend wads of money doing
something which we not only
could do but probably could do
better, and which we would
enjoy doing?

YeSj a ham monitoring sys-
tem would take some organiza-
tion, but it wouldn't be difficult
to handle. Much of the work
could be done over the air, with
unknown signals spotted and
triangulated via a ham net. And
with hams everywhere, even the
UHF channels could be watched
over in every part of the country.
This would raise hell with crooks
using CB or HTs on commercial
channels to coordinate crimes.
There would be no safe frequen-
cy or place in the country for
them. Pity.

FRIENDLY CLUBS

Several letters from readers
have made mention of a situa-
tion which I've noticed in some
clubs I've visited... a lack of
friendliness. Oh, it isn*t inten-
tional ... but it is a drag. I sug-
gest that club officers take a
good critical look at the way
their club is working and start
doing something about it.

When someone new comes to
a club meeting he (or she!)
should be met by members and
introduced around. Each person
shoutd have an identification
badge so newcomers will know
to whom they are talking. Mem-
bers of the club should be aware
that It is their responsibility
to go out ot their way to
be friendly with any new-
comers. . .to talk with them, ..

glad hand out
When the newcomer arrives,

try to find out about him. . .his
call, If licensed. . .or if he is not
yet ficensed and might be inter-
ested In coming to the club li-
cense classes. . .what bands he
works . . . and so on. Then get up
at the meeting and introduce the
newcomer and tell about his
background so the others will
know him. Make a big deal out of
the newcomer and he will be
back. You won't be able to keep
htm away wfth a stick.

In case you haven't noticed it,
darned few hams are outgoing.
The gregarious ham is unusual.
Most hams are loners who may
do just tine on the air, but are
afraid to talk on a one-to-one ba*
sis. You should recognize this
and gear your club meetings to
overcome this situation. If you
have a table where they can
show their new and exciting
QSL cards. . , that's a conversa-
tion breaker. Another table
where they can show something
they've built is another winner.
Perhaps a spot to show off new-
ly-purchased ham gear. , .stuff
that is just recently on the mar-
ket. Everyone is always interest-
ed in new rigs and gadgets.
Anything you can work up in
ways to get members showing
and telling will break the ice and
help everyone have a good
time. . .and it is a good time at
meetings which witi bring *em
back alive next month.

This isn't the time to get into
the details on how to run a ham
club, but I wifi just touch on
some of the basics. Remember
that when you are runnmg a
ham club you are in show busi*
ness. You want to keep for the
board of directors as much of
the dull business aspect of the
club as you can, letting the
meetings be times when you are
entertaining the members.

What is entertaining? Well
demonstrations of unusual
modes of communications are
winners. You probably have
someone in the area who is
working with slow scan and can
knock the socks off the mem-
tjers with color slow scan. Or
perhaps some members are into
computerized RTTY communi-
cations. Anything on 10 GHz?
Any new antennas popped up
which can be shown on a black-
board and explained? Slides of a
Dxpedition are great fun.

How much do the members
know of what is going on in the

MHz? Anyone working with SSB
on 2m? How al>out aurora OX-
ing, meteor-scatter DXing,
moonbounce?

Manufacturers will go a long
way to show their products
when they have something new.
Keep your eye on the new prod-
ucts section of 73 and see
what you can generate. They
want to show their products and
they also want to get feedback
from your members on possible
new products. They need both
the sales and the Input.

DEREGULATION

The interest In deregulation
by the Commission got started
back in 1974, triggered by the en
banc hearing at which a group
of amateurs testified as to the
need for deregulation. This
turned out to be a matter of do-
ing the right thing at the right
time. , .as the Commission was
just at that time getting interest-
ed in the concept. The hearing
made clear the need for deregu-
lation of amateur radio, and the
Commission started with our
service, intending to use it as an
example of what could be done.

The hearing, by the way, was
In response to the then-new reg-
ulations on repeaters, which
were particularly onerous. Lack-
ing any initiative from the ARRU
I got representatives together
from repeater groups all around
the country to testify before the
Commissioners. If anyone Is in-
terested^ I have a tape of this
historical confrontation. The
ARRL refused to participate,
putting the effort down as naive
and useless. The result was the
biggest change in our rules ever
brought about.

Of considerable significance
is a recent paper (August, 1981)
from the FCC. This is a working
paper on deregulating the per-
sonal and amateur radio servic-
es. The paper is quite candid . . .
surprising in its frankness.
There are some interesting con-
cepts., ."many .. .agree that
the goals of expanding techni-
cal skills and manpower and ad*
vancing the radio art have failen
on hard times in recent years." It
goes on, "If there is criticism of
amateurs for not being tech-
nically more advanced, it could
be misdirected. Perhaps one
should place some of the re-
sponsibility on the regulations^
not the licensees. Substantially
more regulatory flexibility than

Magaitne • February. 1982 131

the service now has would be
desirable."

Frankly, that's an understate-
ment.

The other day, on my way
down to Ffofida to give a talk to a
group of accountants who are
using TRS-SO systems, 1 stopped
by Tytts Electronics in Hudson,
New Hampshire. Chuck recently
moved from down near Boston
to tax-free New Hampshire, thus
saving nearby Massachusetts
hams a bundle on their pur-
chases. ThjB new Yaesu FT-208R
HT had just arrived, so I bought
one.

As I punched up the channels
on the synthesizer, program-
ming the unit to scan several lo-
cal repeaters and a simplex
channet or two, I got to thinking
about the whole two-meter US
vs. Japan situation. Having been
in the 2m ham field for over 40
years, 1 remember how things
got started.

The first FM rigs were con-
verted commercial systems,
mostly by Motorola and G.E.—
monsters, dumped on us when
the commercial two-way specs
were changed, rendering tens of
thousands of taxi and police
transceivers obsolete. Then
came a rig from I.C.E. (in Texas)
which never got to first base. . .
mostly because it didn't work
very weJl. The next try was from
Galaxy (Missouri). Though un-
stable and much too large, it
sold reasonably well. The engin-
eering design was dismal. Ed
Glegg, who had been building
VHF equipment for us for years,
came up with one of the better
FM rigs of the time, but by then
some of the Japanese equip-
ment was starting to arrive.

loom was designing very nice
equipment, and it was selling
welL Unfortunately, the com-
pany was taken to the cleaners
by a crooked Arizona importer/
distributor. Nothing daunted,
Mr. Inoue, the president of the
firm, came to the US and
shopped around for a new im-
porter, He also asked a lot of
questions about what kind of
new equipment was wanted, . ,
and listened carefully to the
answers. The result was the
IC-230, the first synthesized
ham rig. Before that, the best-
selling rigs were from Standard
and featured ever more crystal
sockets. I got to where I had to
have hundreds of crystals on
hand to cope with all of the re-
peaters going on the air. . .and
the many different rigs.

Mr. Inoue said that he would
some day be able to put a syn-
thesizer into an HT for us. Well^
we knew It would happen, but it
seemed like a dream. You know,
there was a small outfit out near
Buffalo, New York, which came
up with a synthesizer early in the
game, but they never really fol-
lowed up on it. It started out as a
club project and then changed
into a business. I think if they'd
piayed their advertising right
they could have developed into
a large busmess by now with
perhaps $50 million in sales.

Another firm which had a
crack at it and dropped the ball
was Vanguard, down on Long Is-
land. Andre developed a synthe-
sizer to plug into the older rigs,
but didn't take it the next step,

It isn't really fair to put down
US firms for losing the baJ! on

One of the facts of business
is that the more of the product
you make, the cheaper it is to
manufacture, When you double
the production of a piece of
equipment, the cost of making it
goes down 15-25%. So this
bunch of eager buyers in Japan
has done two things to the ham
equipment market. First, their
enthusiasm has encouraged the
Japanese firms to keep up a
continuing deveiopment of new
equipment. The volume of sales
has forced American firms out
of the market because the
Japanese equipment has been
both better and cheaper in
most instances.

Where the shoe really begins
to hurt is that we are now seeing
the results of the over 500,000
Japanese hams and their enthu-
siasm. These chaps have now

WARNING
Due to numerous compEalnts received from readers who have
dealt with Electronic Specialties, Inc., of Miami, Florida, we
have discontinued their advertisements and urge all readers
to use caution when dealing with this firm.

FM equipment. . .or any other
ham gear for that matter. You
see, the Japanese went right on
by us in the number of licensed
hams, so their firms had a great
advantage. Not only did they
have more hams, but their hams
were much more enthusiastic
and active than we were. Ama-
teur radio really took hold in Jap-
an when they got rid of the
Morse code requirement. Clubs
sprang up in high schools all
over the country, and today they
have double to triple the number
of active hams that we have.
Further, their spirit is almost
unbelievable.

Have you even thought of go-
ing on a DXpedition? Well, the
Japanese have organized DXpe-
ditions where they have had
about 400 active hams going
along and getting on the air!
When you read the Japanese
club magazine you find that it is
packed for dozens of pages a
month with pictures of club ac-
tivities and outings. We don't
appear to have a single club in
the US which even comes close
to the enthusiasm which has
spread through Japan... at
least rm not familiar with any.
I've asked several times for pic-
tures of any outstanding club
activities for publication in
73. . .nothing yet

gone from high school through
college, on into industry, and
are wiping out the American
consumer electronics industry.
Their rate of graduation of en-
gineers, technicians, and scien-
tists has zoomed past ours.

)n this respect, amateur radio
has let America down. If you
stop and think about it, most
technical career people gel
started in their teens. By stop-
ping the growth of amateur
radio in 1963, with little since
then, we have managed to kill
off virtually a whole generation
of technical people. Unless a
person gets interested in elec-
tronics in high school, there is
little reason for him to go into
electronics as a career. So now
we have a bunch of philosophy
and liberal arts majors wander-
ing around looking for work, . .
while our electronics industry is
getting wiped out by Japan.

There really Isn't much we
can do about the situation right
now. We will be outgunned in
technicians for some time to
come. If we are going to get
back into the driver's seat, we
are going to have to figure out
some way to get a whole genera-
tion of teenagers interested in
technical careers. That's quite
a challenge.

In the meanwhile, as I go fur-

ther and further into the instruc-
tion book for the 208, I wonder
what next in HTs. With the LCD
display of the frequency, the 208
should have a substantially
longer battery life than the 207. 1
like the scanning system, , .just
what I've wanted for years,
wherein it scans, stops on a
busy channel for a few seconds,
and then continues scanning.
You can set it up for a priority
channel ... for instance, I gener-
ally monitor 147.540 for simplex
calls. They've even made the
battery compartment so that
you can open it without a coin.

I picked up a mailing piece at
Tufts which was rather clev-
er, . .and sad. The headline on it
was, "Where have all the ama-
teur radio stores gone?'' Then
there are drawings of eleven
graves with headstones for the
eleven Greater Boston ham
stores which have gone out of
the ham business {or just plain
out of business) in recent
months.

With the recent even further

drop in new licensees down

around 35%... ham stores all
around the country are folding.
The ones that seem to be failing
the most are those which had lit-
tle slogans such as, never un-
dersold.. .call for low, low
prices. . .20% off. . .and soor^.
You know, unless we do some-
thing about all this, amateur
radio will soon be little more
than a retirement playground for
elderly hams.

I admit to getting a bit frus-
trated when I visit some ham
ciubs and find that many of the
members . . .old-timers, of
course. , .are prepared to resist
any efforts to bring in new hams
as much as they can. They don't
want the QRM . . . and they don't
much enjoy talking to young
hams... and don*t want them
trying to join their club. They
would like to raise the code
speed to 50 wpm and have every*
one coming in pass the Extra
class license exam, . ,and then
get restricted to the CW bands
for a few years. They like OST,
not 73. These chaps are turning
amateur radio from a friendly
fraternity into an old farternily.

Apropos of the mention of the
1963 debacle, I looked back over
my editoriais and found that I
had indeed predicted at thetime
that one of the resu Its of the pro-
posed rules change would be
the demise of a great many deal-
ers...and manufacturers,
About 75% of the ham dealers

132 73Magazine • February, 1982

went out of the ham business as
a result . . . and most of the man-
ufacturers. It's inlerestlng to
see the old ads for Hammarlundf
HalUcrafters, National, John-
ston, Squires-Sanders, Central
Electronics, Lakeshore, Multl*EI-
mac» United Tfanstormer, Stan-
cor. Bud, Gonset, Polytronics,
and so on. It sure wiped 'em out.

The 208 is a great rig. . . but \i
is not a breakthrough Into any-
thing really new, II we're going
to get amateur radio pepped up,
we have to get into the ^s and
digital communrcatlons tech-
niques. We really have nothing
new to be excited about. FM is a
bore for most of us . . . and heck,
DX has been around for a Hfe*
tiffie. What have we that is really
new and fun? We need some*
thing to get our |ulces flowing.

What have you got?

HAM WATCH REPAIR

Eventually, those Casio C-60
and C-90 watches run out of bat*
tery and need to get a battery re-
fill The replacement of the bat-
teries fsn't a really big deaL . .
you can probably do it. Or, of
course, you can fire it back to
Casio for their $tO repair charge.
Many Jewelers are afraid of dig-
ital watches and claim they
can't fix them. Tsk. t

You can run into a problem
with the Casio watches fn that \
they often do not start when you
replace the batteries. You have
to short out the battery cover
and a nearby metalHc dot
marked ''AC" with a wire, tweez-
ers, or even a paper clip to get/ "
the watch to start again. Jewel-
ers have gotten instructions on
this, but often Just don't want to
be bothered. . .or didn't read
the instructions.

The C-80 and C-90 Casio
watches, which I've written
about before, are the ones
which did the most to put both
Texas Instruments and Commo*
dore out of the watch business.
Casio came out with a $50
watch which knocked the socks
off everything else on the mar*
ket More and more of us around
the magazine are wearing the
C-90, beeping away every hour
in unison.

My thanks to WB90JD for the
battery information on the
watch.

GETTING RICH

Firms which are publicly held
have a problem that privately
owned firms don't have to worry

about: making ever more money
to keep the stock prices high.

This came to mind when I got
a tetter the other day. . .and not
the first one, , .saying that the
reason I want ham growth is so
that f can make more money
from 73 Magazine. Let's take a
good look at that cop-out*

First point. If I were interested
in money, spending tfme on try-
ing to get amateur radio growing
would be one of the last ways t
would invest my time. The real
money today is in microcomput-
ers, and the maximum return for
hours spent is obviously In that
field. Every time I start a new
computer magazine, I generate
a couple of million dollars more
cash flow for us and bring em-
ployment to a bunch more peo-
pie. I also help the microcomput-
er field to grow by virtue of the
communications I bring atx^ut.
No, from a business point of
view, I could care less whether
amateur radio grows or not. If I
were to fold up 73 Magazine,
we'd make more money using
the people and facilities for the
much, much more profitable
computer publications. But Td
miss a lot of fun. . .and amateur
radio would lose a lot of artrcfes
and enthusiasm.

Point Two. Even if we got Into
a great growth pattern and 73
Magazine started to make a
huge profit, the money would go
toward my real goals, not to me.
My goals are to provide educa-
tion through my publications
and through any other medra
available. If I had a million to
spare right now, I would quickly
put it Into the development of
Hawthorne-Green Institute, a
college to teach electron-
ics, communications, and
computing.

I seriously doubt if many read-
ers spend much less on them-
selves than I do. I do have to buy
clothes so I look well, even If I
begrudge the expense. That's
part of being in business. My en-
tire life revolves around the
business. I grab breakfast at my
desk, have a business lunch al-
most every day. . .or else I eat
an apple and cheese at my desk.
Dinners are often with advertis-
ers, at ham clubs, computer
shows, or on trips to visit manu-
facturers. I don't think my wife
and I get together to eat dinner
at home ten days a year. She,
too, is wrapped up in our busi-
ness, and we shiare a two-room
apartment in the old house that
is our headquarters building.

I'm serious about trying to get
American technology back into
the lead and I think I have the
key to this. If you were in my
shoes, wouldn't you feel that
was a worthy goal? Further, 1
think it is a goal \ can achieve.

Probably the *^richest" time of
my life was back in the mid-50s
when \ was the editor of CQ and
also the president of a small hi-fi
manufacturing firm. I made a big
S15.D00 at that time, which is a
whole lot more than Vm making
now in today's dollarettes. I was
able to support a home, family, a
seaplane, an Arabian horse, a
small yacht, and two Porsches.
One of the things which I
learned was that toys like those
own you, not the other way
around. Tlie horse had to be ex-
ercised every day... and
trained. The Porsches needed
constant service, most of which
had to be self*provided. The
damned yacht had to be
scraped and painted every year
or so, the engine worked on, and
so on. The plane? You have no
idea of misery until you own
your own plane, it cost more per
year to own and run than any
two of the other toys. It was fun
and Tm glad I did it, but I'm all
over wanting yachts and planes.

Money has value only for
what it can do towards my
goafs, if I can generate more, I
can do more. . .and there is far
more satisfaction In that than
having a pocketful of hundred-
dollar bills. . .or a bankfuL

I have this dream of being
able to help get amateur radio
into more countries . . . as a way
of helping those countries to
grow. Countries have a desper-
ate need for electronics and
communications experts. . .
technicians, engineers, and sci-
entists. The best way, by far, for
getting these needed people is
via infection of teenagers with
the virus of electronics...
and that means amateur radio.
It works f

If the United States is going to
stay on top over the next genera-
tion or two, we need to invest in
technical people, Tm working on
that via my push to get amateur
radio and computer clubs into
every high school in the country.
I'm also working on it via my
Hawthorne*Green Institute
concept ... a college which is
geared to the 1960$ and
90s... one which will feature
high-speed concentrated educa*
tion in both technical matters
and business. My aim is to pro

vide the education which will
bring us tens of thousands of
entrepreneurs, all with elec-
tronics and computer back-
grounds. Let's see any country
get ahead of us then!

So, when someone puts me
down as looking to make mon-
ey, agree with them... and
point out that so far I have a
good record of investing that
money for the benefit of ama*
teur radio and computing...
and, I hope you'll agree... for
our country.

My ideas on how a college
should be are spreading, Vm get-
ting calls and visits from educat-
ors who are interested in the
plan and who see it as a way to
guJde their schools into sol-
vency in the next few years. With
many private colleges failing,
some radical change is needed.
My talks on the subject in Brazil
and South Africa brought great
intereat, with invites to come
back and get together with gov*
ernment officials to further pur-
sue the idea.

No, If I was Into a personal for*
tune, one of the first things I
would do would be to stop writ*
ing editorials, which Vm sure
would immediately increase our
circulation by about 50%. The
next would be to stop my cru-
sades, such as the very costly
one twenty years ago to self
sideband to the readers— who
hated it and fett that AM was the
only way to go. Or the effort in
1969 to get amateurs interested
In a little-known mode: NFM and
repeaters. While I published
hundreds upon hundreds of arti-
cles on repeaters and NFM, or*
ganlzed FM symposiums, put
out a repeater bulletin, and doz-
ens of books. . .the readers re-
volted, with about 20,000 drop-
ping the magazine in disgust.
Oh, most of 'em came back,
sending me notes saying that,
golly, rd been right, sorry about
that. But it was rough going for
several years.

Not having a house or **family
life" to take up my time, and not
having a yacht, plane, horses,
and dogs, \ have the time to read
so that I can keep up on comput-
er technology, ,, time to keep
dozens of business projects go-
ing, .to personally use comput-
ers, video cameras. . . to go ski-
ing occasionally, to travel...
and even get on the air more
than you might think. I have the
time to write my editorials and
even articles for other maga*

73MagBzme • FebruaryJ082 133

2ines. I can get to Florida to give
a talk on computers to an ac-
counting group (expenses paidh
to participate in a workshop on
how to start special interest
magazines (at the Folio show in
New York). . . to get to South Af*
rica and address data pfocess-
ing professionals on the impact

of microcomputers. . .and so
on, I do have to give up some
things which are important to
most people in order to do what I
enjoy. . , pursuing my goal of ed-
ucatlon for as many people as
possible.

It doesn't take money to do
many of the things \ do— just

time management, I was able to
set the 10.5-GHz record for
states worked with borrowed
equipment because I was will-
ing to go up a damned mountain
at all hours of the day and night
for skeds. . .freezing my gaiuc-
CIS off.

Of course, if I get a lot of stat-

ic about getting rfch, I can al-
ways find some sucker to buy
me out and go for a twenty-year
sail around the world, charging
$50 a contact to the Honor Roll
hams, and live like a king^ An en-
terprising ham can make
$50,000 a year or more that way,
as we have seen in the past.

RTTY LOOP

Marc i Leavey, M.D. WA3AJR
4006 Winlee Road
RandatlstQwn MO 21133

One of the fastest growing
phases of RTTY these days, at
least as evidenced by the ques-
tions I receive from readers of
this column, is "computerized/'
or at least video, RTTY, More
and more, the amateur is getting
away from the old grease-
monger of mechanical tele-
printer and turning to one of the
oew microcomputer systems.

One of those systems hams
appear to be turning to is the
new Radio Shack TRS-30C{R),
the so-called "Color Computer."
Based on the powerful Motorola
6809 central processing unit,
the TRS-80C appeals to the ham
on many levels. Until recently,
however, little was available in
the way of RTTY software for
this computer.

Now, Clay Abrams K6AEP, an
author whose works are well-
known to the readers of 73, Is of-
fering some rather nice software
for the TRS-80C at reasonable
prices, Appealing to both the
RTTY and SSTV enthusiast,
Clay has put together some
rather nice packages.

For the slow-scan television
(SSTV) operator, Clay has three
programs of varying degrees of
capability. SSTV 7.2 converts
the TRS-80C to an SSTV key-
board for sending frames of five
lines each consisting of six
characters. The next step up is
SSTV 7.3, which expands the
previous system to include an
SSTV keyboard, color keyboard,
video mixing, and joystick
graphics. His ultimate system is
SSTV 7.4, which allows gray-
level picture transmission and
reception, color-picture recep-
tion, tape-save ability, and many
other features. The cost? SSTV

7.2 IS only $20, and SSTV 7.3 and
7.4 are $30 each.

Not interested In SSTV, huh?
Well, Clay has a few good RTTY
programs, too! His bottom-line
RTTY program, RTTY 7,01, al-
lows RTTY transmission and re-
ception in Murray and ASCII at
all common rates. Three trans-
mit buffers, an RY buffer, and a
CW identifier are also provided.
All this for $20. Clay's top-
line program, RTTYCW, pro-
vides RTTY transceive, CW trans-
ceive, random code groups,
split-screen display, multiple
buffers, and tape saving. Requir*
ing an external demodulator and
CW interface, the program sells
for the lofty sum of $30.

I nterested? Drop Clay a line at
Clay Abrams Software, 1758
Comstock Lane, San Jose CA
95124. Be sure to mention
that you read about it in RTTY
Loop, OK?

Interest in older machines is
still around. Chuck Euola
K8YPU, of Redford Township,
Michigan, is using an Altair
eaob. This M6800-based com*
puter was introduced shortly
after the Altair 8800, the "origi-
nal" B080 computer. Chuck is in-
terested in receiving RTTY with
his 680b, and wonders if some of
the programs published to run
with other 6800 systems will
work. Other than changing the
1^0 address, the biggest prob-
lem you may have is with the
slow speed of the 680b, as the
clock runs at 500 kHz, roughly
one half to one quarter of most
other 6800 systems. However,
you might try halving the con-
stant in a delay loop, as calcu-
lated for a 1-MHz system, and
then fine tuning as necessary.
The program published in this
column back in July, 1978,

should work reasonably well
134 73 Magazine • February, 1982

Not everybody likes a com-
puter, though. I have a letter
here from Richard E. Christina,
in Pahrump NV, who writes, "I
need a transmitter strictly for
RTTY. . J would like about 200
Watts, 100% duty cycle, tubes,
vfo. . . I do not desire to use a
computer at this lime."

Well, Richard, first of all, let's
get our apples and oranges
straight. The computer, if you
use one, replaces the mechani-
cal teleprinter, not the transmit-
ter and receiver. No matter what
method you use to display the
RTTY signal, from an ancient
Model 12 to a Whiz-Bang 6880
Micro^Term, you still need a
transmitter, receiver (or trans-
ceiver), and antenna to get on
the air.

Now, to the point of your
question. A look through the
back issues of 73 or any other
amateur radio magazine or
handbook will turn up many cir-
cuit descriptions for CW trans-
mitters. Basically, that's all a
RTTY transmitter is: a CW, I.e.,
continuous wave, transmitter in
which the frequency determin-
ing element is modified by the
digital RBY information. Adding
that modification to the vfo, for
example, involves a simple
diode-capacitor combination,
called a "shift pot," that we have
covered in this column several
times in the past few years.

As for the teleprinter itself,
finding information on this ma-
chine or that can also take some

ViOL£T

YEllOw

BLK/QRN

WHT/tlWf

JWHT/BLK I ZUa)"

WHT/ BLU

0THSI /YLW

i::^

GREEN

n£t>

r:3t>

5RAT

WHT /RED

IZ:::&

UIVAC

<l)

doing, 1 have another letter here
from K. D. Hardin KC51I, out in
Albuquerque NM, who recently
purchased a Teletype® Model
3320 and is looking for data on
hooking It up. The 3320 is the
"I/O" version of the Model 33,
and is a very useful machine.
This machine is designed to
work in a 20'mA loop, and con-
nection is via either a nine-
position terminal strip or a
twenty-pin plug, located on the
back of the call control unit. This
is the right rear corner of the
machine, as you face it. Fig. 1 is
a diagram of the nine-pin strip,
terminal strip 151411, at the rear
of the machine.

Unfortunately, not all Model
33s are alike, and minor differ-
ences In the call control unit can
lead to major difficulties in
hooking the machine up. Manu-
als are available from several
sources; see the ads in this mag-
azine for current availability.

I have a note here from Jeffrey
A. Maass K8N0, who relates
that RTTY DXers will have an op-
portunity to add Anguilla (VP2E)
to their DX totals between Feb-
ruary 23 and March 3, 1982. A
group of contesters will travel to
Anguilla to participate in the
ARRL CW and SSB DX contests
between February 15 and March
10J982, and will be taking along
a complete RTTY station. Ama-
teurs using the calls VP2EV
(QSL to K8ND), VP2EJ (QSL to
WA8C2S), and VP2E0 (QSL to

TEfiHIHflL STRIP

PRINTER'

COMMO*i

KE^BOARO

Fig. 1. Modef 33 teletype hookup.

WB8VPA) will be operating in
the time slot detailed above.
Good luck!

By the way, the number of you
(merested in BTTY DXing does
seem to be growing. Not only for
two-way communications, but
for looking for those rare press

and commercial stations, too!
Lt. Mike Anderson, with the U.S.
Navy in Europe, is one of those
folks. So 1 am happy to let you in
on a little tip. A few months
back, I mentioned Tom Harring-
ton's book, Worfd Press Servic-
es Frequencies, in this column.
Available from the 73 Radio

Bookshop at $5.95, this book
contains iistings of hundreds of
commercial and governmentai
RTTY stations. One of the ser-
vices promised by Tom was to
keep buyers updated of recent
"finds" and changes to the
listing. Well, I have received his
latest listing, and it is quite a

gold mine for the individual in-
terested in RTTY monitoring.

Well, this month brought
Groundhog Day! Did the ground-
hog poke his head out of
Baudot, see his shadow, and
ASCII for six more weeks of win-
ter? Who can say? (Murray can!)
Find out here, in RTTY Loop!

A/EIV PRODUCre

TEN-TEC 2-KW
ANTENNA TUNER

Another first for Ten Tec is
a new 2-kW antenna tuner/swr
bridge/power meter. The new
tuner uses a reversible "U' con-
figuration with a silver-plated
roller inductor, high-voltage vari-
able capacitor, and selectable
fixed capacitors for greater ver-
satiffty in impedance matching.
The design automatically pro-
vides a low Q minimum loss
path when properly adjusted.
Power ratfngs are 2 kW PEP and
1 kW CW. Frequency range is
1.a^ MHz. Model 229 matches
conventional 50-Ohm unbal-
anced outputs of transceivers or
linear amplifiers to a variety of
balanced or unbalanced load
impedances. Antennas such as
dipolest inverted *'V"s, long ran-
dom wires, windoms, beams,
rhombics, mobile whips, Zepps,
Hertz, and similar types can be
matched. A built-in balun con-
verts one antenna to a balanced
configuration if desired.

The built-in swr bridge and
dual-range power meter indi-
cates swr from 1:1 to 5:1 and
power from 10 to 2000 Watts.

Front-panel controls are vari-
able capacitor with spinner
knob, roller inductor with spin-
ner knob, 11-position bypass/hi-
lo capacitor select switch, 4-po-
sition antenna selector switch,
swr sensitivity, forward/reverse
switch, 2000/200-Watt power
range switch, and swr/power
meter switch.

Bear panel Includes coax in-
put connector, four coax anten-
na connectors, three thumb-
screw-type connectors for
single wire and balanced line,
ground connector, and 12-V dc
input for dial lighting power.

Styling matches the Ten-Tec
Omni transceiver and Hercules
IJnear amplifier with black and

bronze front panel with blackout
lightfng, satin-finish wrap-
around aluminum bezel, black
textured vinyl-clad aluminum
clamshell top, and bottom with
fold-down stalniess steel bail.
Size:6V2"H x 12V4"Wx ISVa"
D. Wt.: 9 lbs.

For full information, write
Ten-Tec, Highway 411 East,
Seviervilie TN 37862.

MFJ-401 AND
MFJ-405 ECONO KEYER II

The MFJ-401 and MFJ-405
Econo Keyer II from MFJ Enter-
prises is a new full-feature econ^
omy keyer using the Curtis 8044
10 for reliability. The MFJ-401 /405
Econo Keyer II has a much
easier to use design and layout
than the old Econo Keyer line.
All controls are located on the
front panel where they are easy
to find and use.

The MFJ-401 M05 Econo Keyer
fi has front-panel controls for
both speed and volume. The
on/off switch and auto/semi-
auto switch is on the front

The MFJ-401 Econo Keyer U.

The Ten-Tec 2-kW antenna tuner.

panel. This switch lets you use
the Econo Keyer II ]Jke a bug or it
can be used to make tuning
more convenient. A red LED indi-
cates when the MFJ-401 /405
Econo Keyer II is on. It may be
used with an internal 9-volt bat-
tery or any source of 5-9 V dc.
Circuitry is provided for both
grid block and direct keying.
This features lets the keyer work
well with tube-type and solid-
state rigs.

The MFJ-405 Econo Keyer II
has a built-in clear lucite paddle
and a jack on the back for an ex-
ternal iambic paddte. The
MFJ-401 does not have a built-in
paddle, but all other features are

the same.

For more information, con-
tact MFJ Enterprises, Inc.,
PO Box 494, Mississippi State
MS 39762, Reader Service
number 478.

LNR DOWNGONVERTER FOR
SATELLITE COMMUNICATIONS

The new Model DC4-E1 is a
high-performance, low-profite rf
to i-f converter especially de-
signed for small terminal satel-
lite Earth stations. Available in
single thread and redundant
configurations, this unit offers
low phase noise ^n^ good fre-
quency stability for digital and
voice carriers, such as QPSK
and FM-SCPC. The DC4-E1 is
compact, measuring only 1^3/4"
in heightp and is designed for
19" rack mounting. Interfaces
are coax connectors, so that the
signal may be carried on low*
cost coaxial cable. FET LNA
power on the rf input connector
is available as an option.

Low translation phase noise
is ensured by an internal crystal*
controlled phase-locked oscil-
lator. Additionally, designed op-
timization ensures minimal in-
termodulation distortion. Each
converter module is self-con-
tained, including power supply.
The unit is designed for unat-
tended operation and has a re-
motable summary alarm and
front-panel monitors for key op-
erating parameters, LNR is a

Magazine • February, 1982 135

■i^

leading manufacturer of tele-
communications equipment for
satellite Earth stations.

For more Information, please
contact LNR Communications,
Inc., Marketing Department, 180
Marcus Blvd., Hauppauge NY
11787. Reader Sen/^ce number
480.

NEW TOWER TRAILER

For those special situations
that require communications
tower mobility, Aluma Tower Co.
introduces an all-steel trailer for
transporting and erectmg any
Aluma Tower Co. aluminum or
steel tower, Ideal for Field Day,
civil defense, remote signal test-
ing and many other situations,
the tower/trailer combination is
easily towed. Once in place, the
tower is tilted up and cranked in-
to position. The trailer acts as a
secure base.

For more information, con-
tact Aluma Tower Co., 1639 Old
Dixie Highway, Box 2806, Vero
Beach FL 32960. Reader Sen/ice
number 482.

PORTABLE RTTY/CW
TERMINAL

HAL Communications Corp.
is pleased to announce the new
CWR685A Teiereader portable
RTTY^CW terminal. Featuring
compact s^ze and 12-V dc opera-
tion, the CWR685A is just the
thing for the traveling RTTY am-
ateor who wants to "take it with
him.'' A green phosphor 5" dis-
play Is built into the small
12-3M" X ir'x 5" main cabi-
net, as is a RTTY modem for 3
shifts, both "high" and "low"
tones. The keyboard is separate
and connects with a 3-foot cord
to the main unit. Advanced fea-
tures such as programmable
HERE IS messages, type-ahead
transmit buffer, and automatic
transmit-receive control are in-
cluded with the Telereader. The
CWR685A can easily be slipped
into a suitcase for a ham outing.
In the home shack^ the Tele-

136 73Magazlne * FebruaryJ

■i

The LNR frequency converter

The Aluma Tower trailer.

The HAL portable RTTY/CW termmaL

reader consumes little space
and can be connected to an ex-
ternal monitor and parallel
ASCII printer for even more ver-
satility.

For more information, con-
tact HAL Communications
Corp., Box 365, Urbana IL 61801.
Reader Service numtjer 479.

982

SUPERCW

Frontier Enterprises has In-
troduced SUPERCW, a comput'
er-aided instruction program for
the TRS-80 Model I or Ml micro-
computer. Sound and graphics
are combined to teach the user
International Morse Code. By
progressively increasing the

copy speed, SUPERCW brings
the user to 20 words per minute
in as little as 72 hours of
practice.

The disk-based SUPERCW
package requires a 32K, 1-disk
system. Features Include ran-
dom or plain text practice, sam-
ple testing, and provision for
multiple users. For more Infor*
mation, contact Frontier Enter*
prises, 3511 Gallows Road, Falls
Church VA 22047, Reader Ser-
vice number 483.

MOBILE HT CHARGER

Mobile amateurs can operate
and recharge their hand-held
radios anytime with the new HT
Power-ChargerTM from Valor En-
terprises. They simply insert the
charger Into the lighter socket
and attach the mating plug to
the radio. It will charge hand-
held radios in less than an hour.
The HT Power-Charger is not
just a dropping resistor and
diode, but a pair of transistors in
a variable current regulator that
is self-adjusting depending on
the batteries' state of charge.

Mobile amateurs will appreci-
ate the convenient package— all
circuitry Is enclosed In the plug
With no box dangling on the
cord. The HT Power-Charger
features a built-in LED to in-
dicate lighter socket function,
with a five-foot connecting
cable and plug to mate with the
radio. There are six models de-
signed to fit most popular ama-
teur hand-held radios.

For more information, con-
tact Valor Enterprises, Inc., 185
W. Hamiiton Street, West Miiton
OH 45383, Reader Service
number 481,

Valor Enterprises' mobile HT
charger.

I
I

#rMV

m^i ■ I 1.1 I

ORBIT is the Official Journal for the
Radio Amateur Satellite corporation
(AMSAT), P.O. Box 27, Washington, DC
20047. Please write for application.

For a FREE SAMPLE COPY please
send $1 to cover First Class Postage
and handling to: Orbit, 221 Long
Swamp Road, woicott, CT 06716.

MOVING?

Lef us knaiv B weeks in advance so that you won't
miss a single issue of 73 Magazine.
AHach old label where indicated and print new ad-
dress in space provided. Also include your mailing
label whenever you write concerning your subscrip-
tion. II helps us serve you promptly. Write lo:

magazine

Subscription Department

P O Box 931

Fafmingdale NY 11737

D Payment enclosed

D Addrt v> change only

D Extend subscription

n Enter new subscripnon- D Bill me later

D 1 year $25 00 (Canada S27. Foreign $35/US funds)

I
I

I If you huye no label handy, print OLD address here. .

cy% Name,

i'^

Address

t City,

State

Zip

I
I

Name

print NEW address here:
^Cal!

Address p.
City

State-

Zip.

321

— I
_ I
_ I

WATCH FOR OUR NEW PRODUCTS

COMING SOON

istts

ECAST

HAL 2304 UHi DOV,\ . . ', , £RTERS (f flEO flAKGt 2O0O/25O0 MH^j
2304 MODEL #1 KIT EASlC UNIT W/PREAMP LESS HOUSING & FITT^GS
2304 MODEL §2 KIT \m\h presmp)
2304 MODEL t3 KIT ^irtt H^gn G«m pfumpt

WODtiS 2 4 3 A, in C^rtj( f iTTtiiaS "N 1 OUT IU4D WllH WEATHER- P«30F£|J

FACTORY Wll^B&HSTfO fSOad^MiofiAl

BASl C POWER S U P!^¥ , ..__ 119*5

POWtfl SUPPLY KIT FOR *BQVt WITH CASf I24,i5

f ACTOflv WIRED S T^STco t34.tS

ANTENNAS 1 OTHER AQCESSOfllES AVAtUBLE SEND FOR MtHiE INFO

COMPLETE KJTS: CO*JS'Sti**G Of EVEftV ESSENTIAL PART N€fDtO TO WAKE VOUR
COUNTtft COMPETE HAL 600 A T 0lGfT COUNTER WITH fREQUENCY HA»*5£ Of ZERO
TO 600 WH/ FEATURES TWOiNPUrS OPHE FOR LOW FREOUENCV ANO ONE FOR HtGH
FREQUENCE AUTOMATIC Z£»0 SUPPI^ESSlOM TiME SASC iS i 0 5EC Ofl 1 SEC GATE
WITH OPTfONAL TO SEC GATE AVAJLABLE ACGliftACV ±00^% yTiLiZES lO-WH/
CRYSTAL 5 PPM COMPLETE KIT 11 39

HAL'300A ?-^\m COUNTER (SIMILAR TO fiOOA) WITH

FREQUENCE RANGE OF D
COMP-LETEKIT SlOO

HAL^SOA fl-DiGiT COUNTtfl WllM FREQUENCY RANGE OF ZERO TO 50 MHz OR aETTER

AUTOMATIC DECIMAL POINT ZERO SUPPRESSION UPON DEMAND FEATURES TWO iN
PUTS ONE FOR LOW FREQUENCY IhJPljT AND ONE ON PANEL FOR USE WITH ANY «NTER'
NALLY MOUNTED HALTRONIX PRE SCALER FOR WHICH PR0\/lSlONS HAVE ALREADY
BEET* MADE i 0 SEC AMD 1 SEC TIME GATES ACCURACY ± 001% UTIUZES 10-MH/
CRYSTAL 5 PPM COMPLETE KIT $109

FREE: HAL'79 CLOCK KIT PLUS AN iNLtNE RF PROBE WITH PUflCttASE OF Ai^Y FRt
OUEMCV COUNTER

HAL JOO PRE .
HAL 300 A/PRE
HAL 600 PRE
HAL 600 AiPRE.

PRE'SCALERKITS

{Pre-dniled G-IOtKjarci ^nd alt cGmponent&j ... tl4.4£

.... (Samg as abov« but m\h preampji. .... S24,9S

(Pre-dnllBd G 10 board arrd all components) $28.95

tSame as above but «ith pfeamp)

S39 9&

HAL-1 GHz PRESCALER, ^Hf & uhf input i out

PUT DIVIDES B¥ 1000 OPERATES ON A SINGLE 5 VOLT SUPPLY

PREeurLTt TESTED S7« »5

TOUCH TONE DECODER KIT

HIGHLV STABLE OECODEft KIT COMESWlTw^SiOtO PLATED THR^ -'.: SOLOEH FLOWEO
G 10 PC BOARD 7 567 5 ??iO? ASO ALL iLECTROl^tC COMPOKEHTS ffiJAWJ WlAS
URES 3 1/2 ■ 5-1/2 INCHES HAS t ? ilHES OUT ONLY 139.95

NiW— ie LINE DELUXE DECODER %mM

DELUXE 12BUTT0N TOilCHTONE ENCODER KIT UTiLl2lHlG THE NEW iCW
;206 CHIP PflOviOES BOTH VISUAL ' »U0ID ^iprCAliOl^S' COMES WITH iTS OWN
TWO TONE ANOOIZEO ALtiMl*iiUW L«ii *: V-l-SuRES 0«LY 2VA- t 3-3/4" COM
PLETE WITH TOUCH TONE PAD BOARD CRYSTAL CHtP ANO Ali NECESSARY COMPO
*||NTST0NNISHTHEKIT PRICED At *2S,95

r^EW - 1€ LINE DELUXE ENCODER l^d 95

FOfl THOSE WHO WISH TQ MOUNT iHt ENCODER IN A HAND HELD UNiT ThE PC SOAflO
MEASURES ONLY 9/lfi*^ v V3V4- THIS PARTIAL KIT WfTH PC PC-R::! CRvSTAi CHIP
AWD COMPONENTS PfilCEOAT 114.tS

ACCyKEYER (KIT) this ACCUKEVER IS A ^EViSEO VERSrON OF XHi VERY POPULAR
WB4VVF ACCUKErtJ^ ORlGiNALLY DESCflrBEO BY JAMES GARRETT m OST MAGA^iNl
AND THE 1 57^ RADfO AMATEUR S HANDBOOK 116.95

ACCUKEVER — MEMORr OPTION KIT PROVIDES A SIMPLE LOW COST METHOD
OF ADDING MEWOflV CAPA&lliTY TQ [HE WB4VVF ACCUK£VER WHILE DESIGNED FOR
DIRECT ATTACHMENT TO THf. ABOVE ACCUKEYER. IT CAN ALSO BE ATTACHED Tfl ^NY
STANDARD ACCUKEYER BOARD WITH LiTUE OlFfiCULTY S18.95

8UYB0TH THE MEMORY AND THE KEYEfl AND SAVE COMBLf^ED PRICE ONLY *32.00

HAL PA 19 WIDE

PDtNJSj IS dB GAIN

PREAMPLIFIER

BAND PRE-AMPLIFIER. ..'^'Cio MHz BANDW'DTH 1 - MB
FULLY ASSEMBLED AND TESTED »i.9fi

CLOCK KIT ^ HAL n FOURDIQIT Sf^ECIAL - VM.

OPERATES 0^ 12 VOLT AC iNDT SUPPLIED! PROVISIONS FOR DC ft.ND
AtARM OPERATION

6-DtGtT CLOCK* 12/24 HOUR

COIIPLtTE KtT CONS^ST.JiG Of ^ PC G m PRt-DRaLEB PC 60ftfl0S I CiOC« CHIP 6
FNDCOMM CATh readouts ^ 3 TRANS 3 CAPS 9 RESlSTOHS 5 DIOOES 3 PUSH
BUTTON SWrTCHES POWER TRANSFORMER AND KNSTmiClKWlS QOftT BE FOOLED BV
PAl*TiAL«(TS WHERE. YOU HAVE TO SUYEV£flYIH^NG EXTRA PRICED AT 11^.95

CLOCK CASE AVAILABLE AND WILL Fif AN* ONE Of THE AHJVt CL -' - i .^R
PRICE Ifi 50 BUT ONLT U SO WHEN SDU&HT WITH CLOCK

SlXOkClT ALARM CLOCK KIT i OR HOWE CAMPEII KV. OR FlElI)-OAY USE OPfft
ATESON U-VDlT A£ Off OC AND HAS 'TS OWN 60 H| TiM( BASE ON THE BOARO COM
PLETE WTTH ALL ELECTRONIC COMPONENTS AND TWO PIECE PflEORlLtED PC BOAf»DS
BOARD SIZE ■*" k r COMRETE WITH SPEAKER AND SWITCHES IF OPERATED ON DC

There is nothing more to buy * priced at tie.95

■IWELVE-VOLT AC LIME CORD FOR ThOSE WhO WiSH TO OPERATE THE CLOCK f«OM
110- VOLT AC *2.M

SHIPPING INFORMATION; ORDERS OVER S25 WILL BE SHIPPED POST-
PAID E>(CEPTON ITEMS WHERE ADDlTtONAL CHARGES ARE REQUEST-
ED ON ORDERS LESS THAN S25. PLEASE INCLUDE ADDITIONAL $2.00
FOR HANDUNG and MAILING CHARGES. SEND 204 STAMP FOR FREE
FLYER.

DISTRIBUTOR FOR

Aluma Tow«r • AP Products

(We have the new Hobby- BIom Syslem)

.^31

"HAL" ^^ ^-
HAROLD C NOWLANO

W8ZXH

HalTronix

P.O. BOX 1101

SOUTHGATE, MICH. 48195

PHONE (313) 286-1782

,^See Usr of A^¥9f timers on ptagB i 14

73 Magazine • February. t982 137

■1

CLOCKS & KITS

SEE THE WORKS CLOCK

Our Easiest Clock To Assemble

nfffrrrr:

RAodel 850

Six drglts LED clock. 12 or 24 hour
formaL Attractive cfear plexigtas
stand. Kit is complete including pre-
cut and drilled plexiglas stand and all
hardware. Size: 6" H x4-1/3" W x 3" 0

Model 850 _ , _ . _ S29,9S

Model 8S0 WT (Factory wired & tested) . . .

, $39.95

Now available with GREEN LEDs

Model GeSO . _ $39.95

Model G850WT(Factory wired & tested) . ,

(10% off If you buy 3 or more)

6 DIGIT CLOCK KIT

12 or 24 hour format. Six large .5"

digits. 50/60 hz operation. Kit is

complete with aitractlve plexiglas

cabinet.

Model 5314 ....._,,,.._ . $29 J5

Model 5314

MOBILE CLOCK KIT

Mod^l 2001

6 Digit LED dispfay. 12 or 24 hour
format. Will operate 12 VDC or 12 VAC
Accurate crystal time base. LED
display turns off and on with ignition if
desired. Kit is complete with cabinet
and 4 way mounting bracl^et.

Model 2001 R $29.95

($27.95 in qtys. of 3 or more)

60 HZ CRYSTAL TIME BASE

Enable your digital clocks to run on DC power.

Model TB-1 ,....,,.,, , $4.95

Model TB-1 WT (wired & tested) , $9.95

VEHICLE INTRUSION ALARM

Easy to assemble and install, this kit offers options not
normally found in other alarm systems. Hidden switch
mounts under the dash. Kit has provision of sensors and
remote control switch. Programmable time delays for exit,
entry and alarm periods. Basic hook-up utilizes the dome
light circuit activating when doors are opened. The aJarm
will drive a siren or pulse horn at a 1 HZ rate. Not prone to
false alarms due to reliatJle CMOS circurtry. No
external switch required: Complete kit with easy to fotlow
instructions and diagrams.

Model ALR-1 , _ _ ..•*,. **,,,..... , . $14 JS

Model ALR-1WT (wired & tested) , , $24.95

(10% Off if you buy 3 or more)

TERMS: US & Canada add 5% sliipping, handling & msurance.
Fofeign orders add 10% (20% airmail}. Orders under $20.00 add
$1.50 extra handling. COD add $2.00, Visa /Mastercard welcome,
Ohio residents add 4^% sales tax.

Prices subject to change without prior notice.

^307

DEBCO ELECTRONICS

P. O. BOX 9169 DEPT. K

CfNClNNATU OHIO 45209

Phone; (513) 531-4499

BEEPER

The Professional Touch
Comes to Amateur Radiol

tiie-.- •■ ■■■■ in<MCII* Uf '4»*n. • I(m> DMp IB
• r%itpLt tfr iOH ^aAe tram dui'ii^ Atit^

','aff

i-n«hwi CMOS tm^amiirt^ tsm

SP^ for «» w Of* !««'
• &viLtaMft«ctc0t«nwiton 73iV ■

BP-SA: case, c^ble. siatidard 4-piii
C&rinfrctors $39.9& pfid
W*-3B; same as a&Ove* without con-
nectors'.^-.-*-'.****<*'ih36.96 ppd
BP-3C: circuM tioard only, lor
custom Installatiaftft S29 95 ppd

Atl TTHMMt* M* Assamb^sd/tfrfitidi and csny a W day limirsd warrantY Wa
ship FIRST CLA5S^INSUH£tl and m M^EPAY snapping \r\ |h« US X)«fl/af
inqufftes iryiiit9C OHnio iiiftsidartt^ pisase ajjd ^^ ^l«t isx C^ack or nioney

31 48 Oorf Drive,

INC.

Dayton, Ohio 45418

Two-meter HT. Amplifier Kit

1.5watt9 In— 20 out
COR BNG in— SO 239 out
smaH size: 1-3/16" x 3' x 4-1^^
Class C or ABl

ask about
Oiir other
UHF & VHF
amplHrer kits

^459

QRO ENGINEERING

1^8 Edwartfs Ave,

LakewDod, OH 44107

(216)221 9500

APARTMENT BLUES?

Get m the oil NOW)

with
HANDBOOK OF APARTMENT OPERATION

by Don Fox. W2IQD.

Every tt^ing you need to know oboui operating from these

tough spots. Over 150 foot -tilled pages cover

every aspect of oporimem/condo opeiotion,

MONEY BACK GUARANTEE

only S12,50 + $1.50 p&h Check. MC. VISA (card#^ate)
to Wessex Publishing Co. Dept, B9
POS 175 N. Chelmsford. MA. 01863

UNSCRAMBLE

SCANNER ACCESSORIES

FREE LITERATURE

501-623-6027

DNE, INC., RT. 7, BX257 ^13
HOT SPRINGS, ARK. 71901

POLICE CODE

138 IBMagaztne • FebruarVp 1962

MM HELP

I am in need of a schematic or
Instfuction manuaf for a MARC
multiband radio receiver. I wiil
pay copying and mailing
expenses.

Scognamiglio Vincenzo

Piazza Trieste e Trento^ 17

80046 S. Giorgio A Cremano

Naples, Itaiy

I am In need of information on
the Gataxy V MK3, conversion
details for an Aerotron trans-
ceiver, and information on inter-
facing a TRS-80 to a Model 15
printer via an M-80 interface.

Tom Van Schuyler WA2L0J

57 Needle Lane
Levtttown NY 11 756

I am In need of manuals for a
Gonset 3136. an Ameco
5a220^M Hz vfo, and a Seco 520
antenna tester.

Orlo Taylor WASHWM

18412 N. 148tliAve.

Spring Lake Ml 49456

I need help interfacing a DEC
(Digital Equipment Ckirp.) dot
matrix printer. LA-30 (1972 vin-
tage), I have no schemattc or
configuration info, and can't
seem to shake one ioose any-
where, I will pay for copFes and
postage.

Stephen F. Gent WB2VKL

Berry Rd
FredoniaNY 14€G3

I am in need of a service
manuai or wiring diagram for a
Hallicrafters S120A receiver. I
wNI copy your original and
return it to you.

Bill Suffich W4UUC
55 So. Carien St
Mobile AL 36606

I would UkB to phone QSO
with anyone into weather fax
recording,

Dante Ventrier© KA4JRE

17831 NW 81 Ave.

Miami FL 33015

MILITARY SIGNAL GENERATORS

RECONDITIONED AND LAB CALIBRATED

TSr51WU RANGE lO MHZ THRU 420 MHZ AM/CW OP PULSE MODULATION. CAU-
BRATED ATTENUATOR. MILITARY EQUIVALENT TO HPSOaO I ITLm

TS^inJRMjZ. RANGE 3uB TO 7 GHZ, AM/PULSE MODULATION, CALIBBATEO
ATTEMUATOR, military EQUIVALENT TO Hf>6iaA 34^,00

i-fPeCfeA. RANGE 50 KHZ TH RU 50 MHZ AMiCW. G A LfBRATED ATTENtiATOft ASOOT
HP6T2A, RANGE 450 TM«U tZ30 MHZ. AM/fHJLSE MODULATION. CAUfiRATED
ATTENUATOR 47&ilO

HP614, RANGE 90Q THmj 2t00 MHZ AM'PUL^ MODULAnON, CAUfiRAT^O ATTfN.
UATOR i4S.OO

LIRM^ RANGE 10 KHZ THftU 50 MHZ AMiCW, liOOULATlON 400 A \ KHZ,
CAUBftAtlD OWTPUT. PREOStON 50 OHM STOP ATTENlJATOH jmm

URM26. RAP4GE 4 MHZ THRU 40& MHZ AM^CW MODULATION. CAUBRATED
AITENUATOB iftS-W

TS497aiRR. RANGE ? MHZ THRU 90 MHZ CALf&RAT^D ATTENUATOR. AM/CW
MODULATION^ MiyTA^Y VER&pON Qf MEASUREMENTS MOCtELaO ^StSM

SGtJtfU. AfRCRAFT VORrlLS. RANGE lOB THRU t3S 9 MHZ AND 329 9 TO 335 MHZ
OUTPUT SIGNALS INCLUDE VOR LOC, GLIDESLOPE AND 1000 CPS SAME AS COL
UNSiTgrj OPERATES FflOM 2fi VOC AT 3 1 1 AMPS BENCH POWER SUPPLY OR AlP
CRA F T B ATTER lES I DEAL FO R A IflCRAFT RADIO REPAl R aW-OO

SGIA/ARN. AEflCRAFT RADIO SlG GEN WITH PP34a/ARN 1 tSVffiO HZ P/S. RANGE B8
THRU Up MHZ AND 110 1 TO lU 9 MHZ fN fO KHZ STEPS CALIBRATED OUTPUT
400/1000 HZ. MODULATION INT OR EXT, MILITARV EQUIVALENT TO BOONTON SUA

345.0O
SGijMJ, RANGE 20 MHZ THRU ICM MHZ, METERED RF OUTPUT 0-5 V METERED
DEVIATION 0 100 KHZ, PERFECT FOR LOW BAND FM RADIO SERVICING OR USE TO
REPAIR YOUH PRC. GflC, VRC. FM RADIOS 185,00

ABOVE SIGNAL GENERATORS ARE OF EXCELLENT QUALITY, BUILT TQ MIUSPECS
0S-1g1/USM-14Q. OSCILLOSCOPE WITH MX307a^USM HO RIZ CHANNEL PLUG-I M AND
MX-2g30 DUAL TRACE PLUG^IN, 5"CRT. INTERNAL SWEEP, Z4 CALIBRATED RANGES
WITH SWEEP EXPANSJON, TRIGGER MOOES, CALIBRATOR, DC £2 MHZ. HOUSED IN
VENTED AIR COOLED CABINET. SIZE 22' L * U'H » iS" W. A BEAUTIFUL MIUTARV
OSCILLOSCOPE AT A GOOD LOW PRICE 2SS.M

T S 29/U TEL ET^PEWR ITER T EST SET 4i JM

HPSOSVHFBi^lDGE KOO

SIERRA 1268 FREQUENCY SELECTIVE VOL TMETfR " 8S.«>

HP415B STANDING WAVE INDICATOR 4$J0O

UPM-gB RADAR TEST SET liS.OO

URM32tA FREQUENCY METER 13S*< HZ THRU TOCO IIMZ S500

HP741A AC/DC 01 FEERENTIAL VOLT METER DC ST AI*DARD WSJM

FOB OTTO N.C.. 30 DAY MONEY BACK GUARANTEE
WE ACCEPT MC VISA OR CHEC^t P^QNE BILL SLEP (7041 ^^-J^n

Slop Electronics companif

p. O. BOX lOO, HWY 441. DEPI. 73
OnO, NORTH CAROUNA 28763

Electronic Distributors t^M'

WORK THE U.H.F. BANDS

Add a transvertcr or converter to your e?Eisiing lOm, 6m or 2[n equipments.
Choose from the largest selection of modules available for DX, OSCAR,
EME, ATV.
TRANSVERTERS ^^^ 50^144 S234.95

MMT 144-28 $219.95
MMT 432-28 (S) S3 19.95
MMT 439-ATV $379,95
MMT 1296-144 $399.95
^^^^ OTH E R MODELS AV AJLABLE

CONVERTERS

Choose frofn many models to suit your needs.
Examples: MMC 412-2g, MMC 426/439— ATV

MMK 1296-144. MMC l2Sa^ATV
Write for details and available options.

nLTERS

Preveni OSCAR 8 Mode J desense
Use MMF200-7 $42.95

Slop receiver tMD birdies
U-.^ PSF432 S59.95

ANTENNAS ^ ^ "

420-450 MHz J -beams
4a el. 15.7dBdS75.75
88 eL 18.5 dBd $105,50

1250^1300 MH/ loop yagi 1296-LY $49,75

Send 36C stamps for full details of all our VHF/UHF items.

Prc-selector 11 iters

Low -pass fillers

Varactor tri piers

Pre-ampJificrs

70/MBM 48

Transvertcrs

Converters

Antennas

Crystal Fillers
Spectrum InteraalloiijiL Inr.
Post Office Bo\ 1084S
Cuncord. Musis. 01742 I SA

VfSA_

masief Charge

j^436

DOLLAR SAVER/SPACE SAVER

WELZ SP-300 SWR & POWER METER

1.8 to 500 MHZ/1 W to 1 KW

Will S^

Exclusive cross over frequency" range

3 Transmitter/ 3 Antenna Connectors,

One SWR/ Power for the serious amateur who operates all bands, HF

to 450 MHz

Serious Dealers Lisiing Available.

NCG

*^318

1275 N. Grove St.
Anaheim* CaL 92806

(714)630-4541

NOTH: Price^ Specifications subject to change without notice and
oMiualion.

^See^ UstQf Advertisers ^n page 114

73 Magazine • February J 982 139

Hi Pro Mk

LB'VHF-UHF REPEATERS soon to be fcc type accepted

NEW SUPERIOR RECEIVER AND TRANSMITTER SPECIFICALLY DESIGNED
— NEW— FOR REPEATER SERVICE. ADJUSTABLE TRANSMITTER POWER, FROM 1

to 25 WATTS MINIMUM OUTPUT WITH EXTREMELY COOL OPERATION.
^-AUTOMATIC BATTERY SACK UP SYSTEM CAPABILITY WITH BATTERY
CHARGING AND REVERSE POLARITY PROTECTION. --NOW WITH A FULL
COMPLIMENT OF INDICATORS AND STATUS LIGHTS, 100% DUTY CYCLE-
ADVANCED REPEATER SQUELCH SYSTEM NO CHOPPING, POPPING, OR
ANNOYING REPEATER KEY LfPS DURING LIGHTNING STORMS,— DIE CAST
ALUMINUM R.F. ENCLOSURES-SMALL SIZE 5 V^X 19X13' -HIGH QUALI-
TY LONG LIFE DESIGN. — AMATEUR DISCOUNTS AVAILABLE—
■ fr« ni-^i-iifi-n ^FVAiLi^»..-i-.-i^n NOW USED IN ALL HI PRO REPEATERS

Hi Pro RECEIVER and TRANSMITTER also available m kit form

NEW

HI PRO TRANSMITTER

DESIGNED FOR REPEATER

SEflVfCEWITH EXCELLENT

AUDIO, STABILITY,

HAflMONICHEJECTION,

AND LOW

SIDEBAND NOISE.

NEW

SMALL SIZE
37/8 X 6-1/8"

ADJUSTABLE
POWER
OUTPUT—
UP TO 5 WATTS
FROM THE
EXCITER BOARD
COOL OPERATION

THIS EXCITER ES USED TO DRIVE THE HI PRO 25 WATT
POWER AMPLIFIER AND (S AVAILABLE KIT OR
ASSEMBLED,

HI PRO RECEIVER

THIS RECEIVER tSTHE
HEART OF THE REPEATER
AND BOASTS SUPERIOR
SQUELCH ACTION NEEDED
FOR THIS TYPE OF
SERVICE. EXCELLENT
SENSITIVITY, STABILITY
AND SELECTIVITY

USE THIS RECEIVER
TO REPLACE THAT
TROUBLESOME RECEIVER
IN YOUR PRESENT
REPEATER.

WRITE FOR COMPLETE SPECIFICATtONS ON OUR FULL
LINE OF ACCESSORIES AND LOWER COST
REPEATERS.

SMALL SIZE
3-7/8 X 6-1/8"

'46

MAGGIORE ELECTRONIC LAB.

590 SNYDER AVE

WEST CHESTER, PA. 19380

PHONE 215-436^6051

llnlv«r«Al ComnynlcjirioA*

A DIVISION OF INNOVATIVE LABS. INC.

P.O, BOX 339

ARLINGTON. TEXAS 76004-0339

SUPERVERTER I $99.95

The ultimate In converter technology! Dual-stage selec-
tive preamp, mixer, i.f. ampUfler and no*drift crystal-con-
trolled oscillator. We recommend this unit for experl-
•nc^d kit bulldtfft. t2v Stationary Power
Supply, . ,$24.95 for Suparverter L

SELECTIVE PREAMP. $44.50

This new unit Is not tike other wideband preamps. Ex-
perienced kit builders can easily add this unit to our ex-
isting boards or to other manufacturers' boards to im^
prove overall performance,

2300 MHZ CONVERTER KIT. ....,.,,. $35.00

Complete with PC board, parts and 10-page Instruction
book.

VARIABLE POWER SUPPLY. ........ $24.95

Complete kit includes all cofnponents for working unit,
including deluxe box and overlays.

DISK YAGI ANTENNA $25.00

Complete kit with PVC and mounting bracket. Stronger
than loop yagi, and equal In gain.

4-FOOT DISH ANTENNA $54.95

Overall 25 dB gain. Partial assembly required. Shipped
UPS (ground) only.

DL-2000 SATELLITE RECEIVER $749.95

Fully assembled receiver— this is not a kit.

1 20 * LNA $650.00

TERMS: COD, Money Order, Bank Cards (800) 433-5172
HOURS: 8:30-4:30 COST; MON-FRI (817) 265-0391

ORDERS ONLY
INFORMATION

Hope to see you
In Miami

Our product may be copied, but the performance Is never equalled. p q qq^ 339 ARLINGTON

^UNIVERSAL COMMUNICATIONS ^ "^°°^^»^

140 73Magazlne • FebruaryJ982

Are yoii on the verge of drowning in the flood of
t^^hnieal information about computers in the
marketplace? Wayne Green Inc. can help!
Desktop Computing is here, and each month will
explain all about computers without the "com-
puterese/'

Desktop Computing will cut through the techni-
cal hocus*pocus to bring you all the
information you need to take advantage
of the computer age. Thousands of
businessmen, like yourself are saving an
amazing amount of money as they find out
that computers do thing*; faster, provide
access to more information,
and allow a smaller staff
to do more work.
You can provide
more ser\ ices at a
lower cost than
\ou have ever been
able to do before.
Now is the time for
you to get in on the
savings with the "plain
language** information that
only Desktop Computing
can offer vou.

l^he real bargain Ls that all the "plain language"
information you need about computers Ls available
for only S24,97 for a 12 issue, \ear subscription
that is tax deductible!

To order, fill in the couiM>n below. A photocopy
of the coupon is acceptable. I ntroduce your friends

to Desktop Computing — it
makes a great gift! We accept
Mastercard, Visa, American
Express and personal checks or
monev orders. If vou>e not
delighted with Desktop
Computing, well refund
the unused balance of
your subscription.
Take advantage of this
no- risk offer todav.
After all, how
often does your
own [Personal
oasis come along?

coupons to;

Desktop Computing

Subscriptions

Box 917
Farmingdale, NY 11737

One year, 12 issues of Def^top Computing, only $24.97.

Your tirst issue will arrive after receipt of payment.

Canadian, one yeai/US funds only $26,97 1 Foreign, one

>eii3r/US funds only $34-95.

Desktop Computing

PorVbu:

n ChecW money order D MiLStercard O Visa

Q American Express

Name .

Desktop Computing

For a Friend*

32Z&6

Please enter m subficription m niy ^t to:

Njirm; -

Oty _

Slale.

Zip.

Adrin?fiA
City _

Stitc

ZifL

Signature.

.£xp. Date,

.Interbflti)i| ^

IDO

DO NOT VI ANT A C;IFT CARD ENCLOSED IN MY NAME.

Box 917, Farmmgdale. NY 11737

PLEASE SEND IS BOTH COIPONS WHEN ORDERING FOR A FRIEND.

.^See Ust of Adwerttsees on pege 7J4

73 Magazine • February J 982 141

MORSE

RTTY
r ASCII

QUALITY AT AN AFFORDABLE PRICE

MKB-2000

Comptete set of alpltanumeric, pynctuatlon. and

specfal function keys CQ,DE.BK.KN,SK,AaAS.BT

500 character text buffer wtlh BREAK feature

10 reprogrammable 40 character message memories

M99 WPM, WelgW & Intercnar. space. Random Code

BiiMl-in 1 10 VAC power supply

Suffer/Memory fullness indicators

1 ygaf warranty on parts and labor

Attractive ano<Jlzed brushed aluminum and gray

wfinKle finish case, only 13.3 x 9.4 x 3.5 in.

BTTY/ASCII option includes— '^Brag Tape" interface.

CW ID, QBF and BY lest messages, auto CFULF and

LTR/FIG Sfiift 60.66,75.100^32 WPM Baudot 110.300 baud ASCII

Other options --Memory expansion, AFSK modulator

MVD-1000

Copies Morse Cocfe direcUy from your receiver

Automatic speed tracking with self calibration

6-60 WPM speed range

Manual speed tracking to give operator more

control

Active filters and digital sampling for increased

noise rejection

Operates with any TV 89t* no expensfve monrlor

ne^^joo

Two page display with 16 fines of 32 characters per

page

Attractive anodized brushed afumlnum and gray wrinkle

fintsli case, only 3 x 10 x 10 in,

RTTY/ASCil option Includes demodulator

MKB-20QO (Morse Qnlyj
RTTY/ASCI1 Option

Send For
Free rnformafion

S3td,00

50,00

MVD<1000 {Morse Only)
RTTY/ ASCI I Option

S369.00
89,00

Add$5Mfi^ unit tor shipping US. A,

^OGMIelectronics, ffic,

787 BRIAR LANE, BELOIT, WISCONSIN 53511 (608) 362-0410

ORDER

TOLL

FREE

FEBRUARYSALE

1-800-336-4799

ORDER HOURS: 11 am - 8 pm M-F

9 am - 4 pm Saturday

Bonus: 2% Discount for Prepaid Orders
fCash/er^s Check or Money Order}

vtu

Closed fue&days

CUSHCRAFT {other antennas in stockj

A4 New Tnband Beam 10-1 5-20rn 20B,95

A3 New Tfjband Bearn 1 0-1 5-20m .1 6&.95

AV3 New 1 0-1 5-20in Verticai t . , , , 41 ,60

ARX 2B New Ringo Ranger 2m , 33.95

A32-1 9 2ni "Soomer" DX Beam 76.95

220B220 MHz Boomer' 68 95

214B Jr. Boomer 144-1 46 MHz. SI 95

214FB Jr Boomer 144.5-148 MHz.... 61.96

At4 7-11 11 Element 2m. . 34.50

TELEX HEADSETS- HEADPHONES

CI 21 0/Cl 320 Headphones 22-9S/32 95

f*ROCOM 200 Headset/dual Imp. MIC ... 77 50
Pf^OCOM 300 It/wi Headset/ dual Imp m it. 69 95

CASLE IIGS/U Foam 95% Shield 26C/h,

a w*re fiolor 2 #1 8, S #22 1 BC/fr

KLM Ar^TENNAS (other antennas in itock}
iCl34A 4-Elcmenl Tribar^d Beam 320 7B

KT34XA 6'Elem«jiT Tnh^nd Beam . 469.50

144-148 13LS 2m 13' Element with feaiun 77.95

144-146 16C 2m Ig-Elemem for oscar 93,55

420-450 1442O-450 MHz 14-eiemem beam . , 37 54
420-450 1 8 C4 20-450 M Hz 1 a-e{«n eni osc*r 58 70
432 16LB1 6 elem. 430^34 hAHz beam/babn 60 70

HUSTL£R 5BTV lO-BOm VerticaJ . 92 50

4eTV I0-40m Veftic^* 73 95

3TBA Hwm 10-1 5-20tii Beam 1 88 95

HF Moliil« R«SQn0tors Standard SopttT

10 and 15 metei 7.95 12 50

30 met* r? 10.95 14 95

40 meters 12.50 17 30

75 me^i-rs 1350 27 95

Av*rni AP 151.36 2m on glass aflt . 27 95

TEN TEC SPECIALS

515 Argonaut HF XCVR . , 399

525 Argoiy HF XCVR 469

580 Dfltta HF XCVR , , . , , , 748.

546 Omni-C HF XCVR 1040,

TEN'TEC AdcessoHes
III s.iin:k jii I discount prices

MFJ PRODUCTS {Calt for other MFJ ttems)

389 Nflw 3KW Tuner , .

962 1 5^W Tuner mir/swdch

949 B 300 wnX^ delude (uner, , . , .

941 C 300 wati tuner swnch/fnif

940 300 wair tuner swucii/mtr. . ,

484 Grttndrn^iifer memory kever t2 m«g

482 4 ms9 Memarv liey«r. , , , .

422 Pacesetter Kcyer w/ Bene her BY! .

408 Deluhe Keyer with speed mtt.. .

496 KeyiHiaid 11

7528 Pijal tMrnable 'filler

102 24-hOLjr clock
DAIWA/MCM

CN 520yCN 540 Wati Metar*.

CNW41 8,-'CNW 5 \ 8 Anienna Tune^.

CMA 2002 Auto 2 5W Tuner
ASTRON POWER SUPPLIES 0 3.8 VDQ

R57A 5 amps cor»i4nuOii«. 7 *mp ICS

RS!2A9 ampft commuDut. 12 amps ICS

RSZOA 16 afntts cortlmuouS. 20 »mps JCS

RS20M samp as RS20A + m^tefs

RS35A 25 amps eortiifiuous, 35 smp ICS

RS35M same as RS35A 4 me<ief«
MINIQUAO Hai
ALLIANCE HD73 Roiof
CDE HAM IV ROTOR

96
00
95

287,

199

122

121

296

76,

59.95/69.

169 95 .'279

399

66.

87
105
131
151
t29.

91
169

75
95
00
42
70
72
96
15
69
95
42
95

95
95
95

60
35
20
50
95
95
95
95
95

VoCom Antennas/2m Amps

5/8 wave 2m hand held Ant .

2 watts in. 25 walls oui 2m Amp . . , .

200 mw in, 25 watts oui 2m Amp. .,,,,,,

2 watts in. 50 watts out 2m Amp , . .

MIRAGE AMPS & WATT METERS

MPI HF/MP2 VHF SWR/Watt Meter

B23 2 in, 30 out. All Mode

B108 10 in. 60 out. AH Mode. Pre*Amp. . .

B1016 10 in. 160 out. All Mode. Pre Amp
BENCHER PADDLES Bleck/Chrome. . . 35
BUTTERNUT NEWf HF6V 10 SOm V*rnc*l

+ b b I

19.96
69.96
82.95

105.95

. . . CALL
CALL
. . . . CALL
.. 235 95
25/42.96

SUPER SPECIALS

AEA bopole Ant-. Keyers. Code Readers . CALL

ASTRON POWER SUPPLIES
VS35M 25 amp continuous ad^«t«bla. ..... 171.00

V520M 1 6 antp continuous adjustable. . . . * . 124.00

AZDEN PCS 300 handheld. 2m. 269 95.

PCS 3000 2m XCVR wdh Tone Kit , . 294 00

SAftlTEC H7120O 2m handhdd 27900

S7*7/7 440'450 handheld 284 00

MtW SANTEC 2m h 440 MHz handhelds . Call for Qyotvs

KDKFM2025A 26995

BIG DISCOUNTS

KeNWOOD. ICOM. YAESU. A20EN. KOK
— Call for our quote —

HY-GAIN ANTENNAS

N£Wf TH70XX Triband &e*nft CALL

TH3MK3 3-E1emcnt Beam. 1 79 95

TH3JR 3-Elemenl Tnband. 138 95

1 SAVT/WB 10-80 Ven<cal 82 95

T4AVQ/WS 10-40 Vertical 50.77

ORDER IMFORMATrON
Ordei^: 1 -800 336 4799

Information

at^d Virginia ordars: (703) 643-1063

Stofft Hours: M-W-F: 12 noon-S pm

SatuTday: 9 sm-3 pm

Mailing Address: 24 1 0 Drexet St

Woodbridge, VA 22192
Store Locatfori: 1 44T 5 Jefferson Davis Hwh^.

Woodbridge, VA22191

,^453

— CALL FOR QUOTES —

Send stamp for a flyer- Temis: Pnces do not include
shipping, VISA and Master Ct^arge accepted, 2%
discount for prepaid orders (cashier's check or
money order}. COD fee S2.00 per order. Prices
subject to change without notice or obligation,

142 73 Magazine • February, 1982

Wayne Green Books

i:trciii0Nacs

bill Jd your

■TRS-80 IS a ifademarfc Ot

fladKj Snack Oivlsion of Tandy Cotp.

Annotated BASIC— A New Technfque for Neophytes.

BASIC programming was supposed to be simple— a beginner's programming
language which was so near to English that it could be easily undefstoo<l. But, in re-
cent years, BASIC has become much more powerful and therefore much more dif-
ficult to read and understand. BASIC simply isn*t basic anymore.

Annotated BASfC explains the complexities of modern BASIC. It includes com-
plete TRS-80' Level II BASIC programs that you can use. Each program is annotated
to expfain in step-by-step fashion the workings of the program. Programs are
flowcharted to assist you in following the opefational sequence. And— each chapter
includes a description of the new concepts which have been introduced,

Annotated BASiC deals with the hows and whys of TRS-SO BASIC programming.
How is a program put together? Why is it written that way? By observing the pro-
grams and following the annotation, you can develop new techniques to use in your
own programs— or modify commercial programs for your specific use.

AnnatmtKi BAStC V^lami f cofltaifvs Profectino Profiis, Sunwyof. Ttitnts to Do. Tas She^ief. IfHroducfion to
Digaai LoQic Cameloi, The S<mmleit Code. Dedi*ctKm, Op Amp, Contraetof Cost Esiimaiing, (avatlalite
November) BK73a4 S10.9S ISSN 0«d006^02S-X

Annoistmi BASIC Vo/uma 2 coniains Rougti Lumber U%t Trip Mileage. FH^ght Ran, OSCAR Data, SWWAmefina
Design. Supemia^e. Petals Around llTe Ros«, Nume/c Analysis. Demons. Air Raid, Geography Test P1iumb*ng
System Design, (available February) 8K7385 Si 0.9$ iSSN 0>^00&037^9

Order Both Volumes and Sawe! BK738402 $18.95

Kilobaud Klassroom—

A practical course in digital electronics

by George Young and Peter Stark

Learning electronics theory without practice isn't easy. And it's no fun to build an
electronics project that you can*t use. Kilobaud Ktassroom, the popuiar series first
published in Kifobaud Microcomputing, combines theory with practice. This tsapracti-
caf course in digital electronics. It starts out with very si m pie electronics projects, and
by the end of the course, you'll construct your own working microcomputer!
Authors Young and Sta/k are experienced teachers, and their approach is simple
and direct. Whether youVe learning at home or in the classroom, this book pro*
vides you with a solid background In electronics— and you'll own a computer that
you built yourselfl

Kilobaud Klassroom contains Getting the Ball Rolling, Gates and FIJp-Flops Explained^ J.K. Flip'Flops and
ClocKed Logic, PC Boards and Power Supplies, Hardware Logical Functions. Voltage, Current and Power Sup-
plies. Transistors, Diodes and OP Amps, Pufeses and Mof© Putses, Counters and Registers, Bus Traffic Con-
trol, ROM and RAM Memories, I/O Circuluy, Para^le1 and Serial I/O Ports, Computer 1^0 lU, Computer I/O W,
Computer I/O V, Processor Connections. Finally. , .The Kilobaud Krescendo, Eproms and Troubleshooting,
^Kpansions and Programming, Machine-Language Programming^ AB^embly-Language Programming, Con-
necting to the Outside World. ... ^ ^,s^~mj^^^ ^^ M ^^

ISSN 0^8006027 1 (available December) BK7386 $14.95

The New Weather Satellite Handbook

By Dr. Ralph E Taggart WB8DQT

Here is the completely updated and revised edition of the best-selling Weather
Sateiflte Handbook— containing all the information on the most sophisticated
spacecraft now in orbit. Dr Taggart has written this book to serve both the ex-
perienced amateur satellrte enthusiast and the newcomer. The book is an Introduce
tion to satellite watching that tells you how to construct a complete and highly effec-
tive ground station. Not just ideas, but solid hardware designs and all the instruc-
tions necessary to operate the equipment are included. An entire chapter is devoted
to microcomputers and the Weather Satettite Station. And for the thousands of ex-
perimenters who are operating stations, The New Weather Sateftite Handbook
details all the procedures necessary to foitow the current spacecraft.

Weather Saieilite contain* Otserational Saleltde Syatema, Antenna Systems. Weaihef Satellite Recewef^, A
Cathcjde Ray Tube (CITTl Monitof fof Satellite Pictufe 0i5|»l*y. A Dir^ci Pfinting Facsimile System for Weather
Saleltite Display. Ho* to Find trie Satellite^ Test Eqitlpmofit. MicrocompulefS atnS ttw Weattief Satellite Station,

siation op«aiions. is8N aaflooMiM available HOW ! BK7383$8.95

FOR TOLL-FREE ORDERING CALL 1-800-258-5473
WAYNE GREEN BOOKS • PETERBOROUGH NH 03458

Use ttie order c«r<J or k\emizQ your order qn a separate piece of paper and mail lo Wa^no Green BooK AH: Sales • Peterborough NH 0345S.

Be sure to include check or detailed credil card information. (Vl&a, Master Card or American Enpfess accepted,)

No COD orders accapTgd, All orders add Si. 50 for first ^ok^ S1.O0 each additmnal Dook. St 000 per tiook foreign airmaiK

Please a^o* *"$ weeks after publicatiofi lor deHvery, Questions regarding yoyr order? Please wnie to Custorrjer Service at ttie above address.

From

THE
MOST

'^mGAZINE

UP-TO-DATE
REPEATER

iTLAS

ATLAS
AVAILABLE!

INCLUDES:

• USTINGS BY STATE AND COUNTRY

• LISTINGS BY FREQUENCY

• MAPS FOR EACH STATE

• 28 MHZ THROUGH 1 296 MHZ
•PERFECT FOR MOBILING

• WORLD REPEATER ATLAS— BK73 15— Completely
updated, over 230 pages of repeater listings are In-
dexed by location and frequency. More than Sd maps
pinpoint 2000 repeater locations throughout the USA.
Foreien listings Include Europe, the Middle East. South
America and Africa, $4.95.

IN STOCK AND READY TO SHIP

"Use the order card \n the back of this magazine or itemize your order on a

separate piece of paper and mall to: 73 Radio Bookshop* Peterborough NH

03458. Be sure to include check or detaNed credit card Information.

No C.O.D. orders accepted- Add $1.50 handling charge for the first book;

$1 00 tor each additjonat book. Ouestfons regarding your order?

Please write to Customer Service at the above address.

Please allow 4-6 weeks for delivery.

FOR TOLL FREE ORDERiniG CALL 1-800-258-5473

From

MAMZIHE

THE 1382 EDITfON

GENERAL LICENSE
STUDY GUIDE

by Timothy M. Daniel N8RK

This is the complete guide to the General License.

Learning ratlier than memorizing is the secret. This

Is not a question-and-answer guide that will gather

dust when the FCC issues a new test, instead, this

book will be a helpful reference, useful long after a

ham upgrades to General, includes up4o-date FCC

rules and an application form*

ORDER yours today and tailt to the world.

SG7358 $6.95

The 1982 edition will be ready to ship in February.

^Use the order card In the back of this magazine or itemize your
order on a separate piece of paper and malJ to: 73 Radio
Books hop'Peterbo rough NH 0345B. Be sure to include check or
detaii^d credit oard InformatJon. No G.O.O. orders accepted. Add
$1.50 handling charge for the first book; $1.00 for each additional
book. Questions regarding your order? Please write to Customer
Service at the above address, Please allow 4-6 weeks for delivery.

FOR TOLL FREE ORDERING
CALL 1-800-258-5473

A recent survey showed that 20% of the 73 subscribers aJao read
Kilobaud MICROCOMPUTIHG magazine . . . andenjoy it^Thisisthebest way
to learn and keep up w£th the rapidly developing woi^ld of microcomputers.
There* 5 nothing to be afraid of, you just have lo read an interesting
magazine and youll learn* Try a subscription to Kilobaud MlCROCOmPtlTING
and see for yourself,

n Mew subscription D Renewal G 12 issues for $25,00

Q Payment enclosed $ D 24 issues For S3a,00

O VISA D MC n AE a em me Das Usues for $53.00

Cardn

Signature
Name

Interbank §
^Exp.date

Address
City

State

Zip

—for even faster ordenng service cali tofi free (300) 258-5473

Canadian; $21, one year onty^ U.S. funds. Other foreign:

$35^ one year only, U.S. funds. Please allow 6-8 weeks for 322 B6

delivery.

WiCROCOMPmjMG • POB 997 • Farmingdale HY 1 1 737

Arise and subscribe to 80 MICROCOMPUTING, the
newest and fastest growing microcomputer magazine. This
is full of news about programs, accessories and theory on
the world's largest selling computer, the TRS-80*—
defintteiy beginner level and includes lots of program
listings. Find out what all the fuss Is about.

H. New »ub&crlptlon
UPayiTKfit encioaed *.
LI VISA L_WC

Card #

L'. Renewal

UAE

GBilli

G 1 2 Issues for S25.0Q
□ 24 issues for S38.CH)
D 36 Jssues foT $53.00

Interbank #.
Slgnature_
riame

Exp. date.

Address
City

State.

Zip

'microcompyting

Please allow 6 weeks for delivery
Canadian: ] yr. only7$27 In QS, Funds
Foreign: 1 yr, onVS35 In tJ.S. Funds

• P.O.B. 981 • Farmingdale N.Y, 1 1737

*TRS'B0 is a trademark of Tandy Corporation.

32286

144 73Magazine • February, 1982

Take your favorite H.T. out
for a drive tonight.

VISA or MASTERCARD for
same day shipment.

For $64.95 you get the most efficient,
dependable, fully guaranteed 35W 2 meter
amp kit for your handy talkie money can buy.

Now you can save your batteries by operating
your H.T. on low power and still get out like a
mobile rig, The model 335A produces 35 watts
out with an input of 3 watts, and 15 watts out with
only 1 watt in. Compatible with IC-2AT, TR-2400,
Yaesu, Wilson & Tern pol Other 2 meter models are avail-
able with outputs of 25W and 75W, in addition to a 100W
amplifier kit for 430MHZ. ^^382

Communication Concepts Inc. ^^5^^-^-*-^"^*- ^"^^*^

f^.

IRON POWDERand FERRITE PRODUCTS

AMID0IM^

Fast, Reliable Service Since 1963

Small Orders Welcome

Free 'Tech- Data' Flyer

Toroidal Cores, Shielding Beads, Shielded Coil Forms
Ferrite Rods, Pot Cores, Baluns, Etc.

12033 OTSEGO STREET, NORTH HOLLYWOOD. CALIFORNIA 91607

ASSEMBLY, VEBY

RUGGED

i$O-440

ANTENNA FOR YOUR NEX

VHF OR UHF BASE
STATION INSTALLATION

fBO'144
ISO-220

FOR A^ A ANTENNAS
OR OTHER AEA PRODUCTS,

CALLORVrSIT:

AEA

Brings you the
Breakthrough!

MAST NOT INCLUC^D

BRITT'S 2WAY RADIO

SALES & SERVICE

2508 Atlanta St. Smyrna, GA 30080

CALL: (404) 432-8006

ICOM

WINTER SALE

Now! EEB Is The Only

ICOM Authorized

Service Center

In The

North

East

Buy With
^D l^^ Confidence

AT YOUR SERVICE

Dick
Danny
Curtis
Scott
Lafry
Ned
George
Mary

-K4EIH

WA4SDE

-WB4KZL

WB2YSY

-KOLB

-K4SYF

-W4EV

Ellen

ICOM

IC2AT
IG3AT/4AT
1C25A
IC730DC

Cheryl

FULL ICOM
LINE ON SALE

NET SALE

I 269.50 $242.55

$ 299.50 S269.55

% 349

% 829

$40,00 factory rebate ex p. Feb 27th
Your cost will be $689.00
IC 720 ADC $1349

IC251A $ 749

I C 290 A $ 549

IC451A $ 899

$314.00
$729.00

$1199,00
$669.00
$439 00
$779.00

FULL YAESU LINE ON SALE

FT208R

$ 359.95

$323.00

FT708R

$ 359.95

$323.00

FT 707

$ 810

$729.00

FT lOIMKMI

$ 925

$799.00

FT 290R

$ 399

$359.00

FR 7700

$ 549

$479.00

FT 902DM

$1535

$1379.00

FT'ONE

$2995

$2,695.00

Becomina vi

Durfll Am

ateurStoi

Visit us on your next trip to
Washington, DC.

order desk

(800) 336-8473

prices subject to change

Tue-Sat

10am-4pm EST

Technical information,
VA orders (703) 938*3350
Store opens 10am Tues-Sat
Close 5pm Tues, Wed, Fri,
Close 9pm Thurs, 4pm Sat

516 Mill Street. N.W.
Vienna, Virginia 22180

ELECTRONIC EQUIPMENT
BANK

*^See Ust of A dver timers on pag& tH

73 Magazine • February, 1982 145

ASSOCIATEa RADIO

aoie coNSER box 4337

OVERLAND PARK. KANSAS 6B904

BUY

All Brands New & Reconditioned

9i3-38i-SaaO

TRADE

€- *\

mjr-n:\n i

< * • ^ * * * \

l«t.« 'J

^Oi^

r**

:.t OL

4 -i-^^

m ^L- «

htQilS •'*0'

9t?:. 9^V?g.

i _ *

« ^ » u

^'• •^

IankAmericaro

7WMC

master charge

We Want to DEAL— Carl Us— We'll Do It Your Way.

WE'RE #1 _

NOTE: SEND S1.00 FOR OUR CURRENT CATALOG OF NEW AND RECONDITIONED EQUtPMENT^

* ALSO WE PERIODICALLY PUBLISH A LIST OF UNSERVICED EQUIPMENT AT GREAT SAVINGS.

A BONANZA FOR THE EXPERIENCED OPERATOR,

TO OBTAIN THE NEXT UNSERVICED BARGAIN LIST SEND A SELF ADDRESSED STAMPED ENVELOPE

ELEGANT"

DESKNEO FOR THE PARTEULAR HAM.

CLUHERFREE CONSOLES

PRICES START AT $203.35

SEND FOR FREE BROCHURE

•1^89

TAlcoma. WA/UM {20») 7fia!frf|

140 73 Magazine • February. 1982

THE AUTEK "QRM ELIMINATOR"

Model QF-1A
For SSB & CW
$73.00

Corvilfiuously varl- Corttinuousiy varh

able main selectivity able main frequsiHy.

(to an IncredJbla 20 (250 to 2500 Hz)
Hzri

1f 5 VAC Supply butll^ Auxiliary Notcli re- Four main filter

in. Filter by pa ss&d jectsSO to 11,000 Hz! modes lor any QRM

when off. Covers signals other situation.

notches can't touch.

AUTEK pioneered the ACTIVE AUDIO FILTER back in
1972. Today, we're still the engineering lesder-Our new QF-
lA is the latest exarnple. \Vs INFINITELY VARIABLE. Yoy
v^iy seiecUvity 100;1 and frequency over the entire usable
audio range This Jeis you feiecl whistles with dual notcJises
(10 70 dB), or reject SSB hiss ancf splatter with a f jHy ad-
justable lowpese plus au*. notch. Imagine what the NAR-
ROWEST CW FILTER MADE will due ro QRM! HP rejects
Jovtf kequencies. Skirts exceed 80 dB. 1 watt speaker amp.

Built-in 115 VAC supply. 6V2x5x2Vi. Two-tone grey styling
Even latest rigs include or\ly a fraction ot ihe QF-1A
sel-ectivrty Yet il hooks up in minutes to ANY ri^-Yaesu,
Kenwood, Drake, Swan, Atlas, Tempo, Heath, CoH"ir>s, Ten-
Tec, etc, Just plug i1 into your phone jack and connect spki.
Of phones lo the oulpuL Join the thousands &f owners who
now t>ear stations ihey couldn'l copy without a OF-1A! Il
really works!

WORLDS RECORD KEYER. OVER 4000 DX QSO'S IN 2 DAYS!

Probably the most popular "professional" contest keyer
In use, yet most owners are casual CW operators or nov-
ices. After a few minutes, you'll see how memory revolu-
lionizes your Cvy operation! Just start sendmg and record
your CQ, name, QTH^ &{c. in seconds. 1024 bits stores
about 100 characters (Fetters, numbers). Playback at any
speed. Dot/dash memories, triggered clock, repeat, com-
bine, 5 to 50 -H WPM, built-in monitor and 115 VAC supply.
Wofhs with any paddle. Sit back and relax whiieyour MK-1
calls CQ and handles standard eKchanges!

Optionat memory expandei' IME-I) expands any MK-1 to
400 characters. ME-1 factory I r» stalled $35. Owner in-
stalled, only $25. Add more memory now or iatert

Model MK1 Keyer $104.50

NO LONG DELAYS. WE SHIP 95% OF
ORDERS FROM STOCK

We sell only factory dtrsct. No dealer markup In our prtce.
Order with check, M.O., VISA, MC. We pay shipping in 48
states. Add 4% tax in Fla. Add $3 to Canada, Hi., AW. Add
$18 eacji et sew here. (Shipped air.)

Model 173DM

Dual, independent cfocks/Solld walnut case/

Functional and beautiful
$69.95 (plus $3.00 shipping)

Model 173B

Internal backlight/Aluminum

and Poly case^ Portable

$34.95 tpJiis $3.00 shippings

Independent Military Option

Military time format clocks by Benjamin MichaeL Independent of power
lines these units are energy efficient, secure, and free to provide
accurate quartz controlled time in any setting. Used by the Military and
U.S. government agencies as well as many municipal taw enforcement
and public safety departments, these units won't quit just because
commercial power did.

Exercise your independent military option now.

**'42Q

O U INC.

65 E. Palatine Road

Prospect Heights, IL 60070
312-459-5760

EAST COAST #1 GOES
NATIONAL

THE ANTENNA BANK is
East Coast's #1 supplier of

ANTENNAS — TOWERS

ACCESSORIES

CUSHCRAFT:

A3 Nevi^ El^rn^nt Tnbiand Beam „.. 5165.00

A4 New 4 Element Triband Beam....,.,..,,...... $204 00

AV3 New 3 Band Ver^^dan0-20m ..,. * 4(5.00

AV4 WeWf4 0aod Vert icaJ 1040m. ... S 81.00

AV5 New 5 Band Veritcal TD-aOm $ BT.oO

RS 20-15' tOm Motor tuned Vef tical ,,„.... S20?.0q

32-19 19 Element 2m BDom-er DX BeaiTi..,.......i, S 74 00

2MB u Eiern&nt 201 Jr. Soomtr \A4-\AU.. S eO.OO

Al47'ii tl Element 2fn.,. $ 33.00

ARX2B2m ■■Rifigo Ranker" H.....„. t 33.00

-COMPLETE LINE OJSI SALE-

MlNl QUAD HQ-1 e-10-T5-20m

HYGAIN:

V2 He-A 2m V&rlical

TH3JP 3 Elemeni Tritjand Beam

TH3MK3 3ElementTflbandBeam

TH5D)( New 5 EiemenE Tribai^d Bearii

TH6DXX 6 Element Tritiaod B^am

vDSBASEtemeni lOfn^'Loi^gJotin'

1556A5 Element 15m "LDng John"

20SBA5eiemeftl3iOFn-L-ongJohn-

t4AVC!4Banfl Vertical 10 40m

IBAVT 5 Band lO-SOm Trap Vertical

-COMPLETE LINE ANTENNAS OMLY OM

$129.00

. S 33.50

$1 33 00

.. .S175.0O

... ,195.00

|£3&,00
...J 95.00

SMS .00
.. S235.00

$ 4f^.tX)
....$ 7S0O
SALE-

ROTORS & CABLES:

CDE HAM IWCD-lIill .

Allj^ftce HD73,iU100

RG^^U Foam 95% Shield

RG2t3Mii Spec

Mt-ni-S

.$165.00/94.00
593 0*42 00

24*^i|.

2a<F^[L

12tm.

8 Wire Rotor Cable .,,.16«^IL

Phjlly Slran GLiy Cat>Fe in sioqK— for price & delivery
inlormalioi^ caH <7031 569-1200

#1 ROHN TOWER DISTRIBUTOR
SALE:

20G tO'To'ATB/ Sect ion £29.50

25G 10' Tower Settmn 5 3g'.50

45G tD'ToweiSactiOn $ fi?.50

H D B X 4^' Ff fl€ Sra nd i ng Tower tt^20 00

FP|254» 4B ■ 25G Fo I d-ovet Tovv fic 5695 .00

iFroiqiT^t prepafcd an Fcldover Towers Pnces iD^-v. highoF
west ol Roci^y M:oun tains)

We StocK Rorin Accessories— tor pnoe 4 delivery n>tor-
n^iahon <is\\ |703) 56.9-1200

HUSTLER SPECIAL COMPLETE
LINE:

4BTV.i"5BTV 4 Or 5 Band Vertical
MO-liiMO-a HF MQtJilB Mast...,,..

.$74.00'92.0O
. S 1/60

HF MOB RES. 5TD 4kw

10 OF I5m $ a.OQ

2Dm... ......,...:...S11 00

40m.. ..,,........,.. SI 3.00

75m J 1.4.00

SF2 2m5ySWriip...

HOT ■■■Husileolf" MounL

BM'T Bumper Moun! with Ball.

SUPER 2 OKw

- $14

- *15

^ sie

- »20

00/
00::

9.00
14.00

.$ 13.00

AVANTiAPTSl.3G Glass Mount.. S 27.95

W2AU Saluo ' — "'"S:17.55 Lisl^SaJe £ 13-35

Traps 10. 15. 20or40flri--— — -S24.95Lisl^Saae S 16.79

VAN GORDON:

PD BOlO I0-a0m Ware Dipole S 26.80

PD40miO-40TnWFfeDipOJe. . S 25.20

PDe04040-80mW<raDipole ,, S 26 40

SD40 40triSf»Of1 DipOle S 2160

SDaoaomShori Dipole S 22.BD

HiQ Balun IT0.9& List/Salfi $ 7.95

HjQ Center ..S 5.95 Liat/Sale £ 4.95

ORDERS ONLY
(800) 336-8473

ALL OTHER CALLS (703) 569 T 300

Shipping cost net included— Prices subject tocliange

ALLOW 2 WEEKS FOR DELIVERY

No COD— We ship UPS

We reserve tlie right to limit quantities

THE ANTENNA BANK

6460 General Green Way

Alexandria, VA 22312

Tij^im I nai-^s I

See Ust of Advertissrs on page 114

TSMagazine • February, 1982 147

FACTORY-DIRECT INFLATION FIGHTERS!
PRICES SLASHED DRAMATICALLY!

MULTTWETEft

POVHER

MODEL

T^l? MM-T 15 High qu^liiy 20Korim/VDC Mummetpr us^tiJe <is
int S*u?/R3weF Meier ds well Dy comecung The d^^«:tjon^(

CCujpkrr unat iradudrtl

DC Vok 0 - 0.3. 1.2. 6. 30, \20. 600V j20»<-ohm/V) t 3%

AC Volt 0 — 6. 30. IZO. 600V faK-ohm/Vj t 4%

OCmA 0- 6(XA 3. 300mA i 3%

OHJVl ....,.,.,. .,,, Rxl RkIO, felK

dB — 20— +TBO— ♦32dSm

C 200pF — OSuF

U ,.,., 0 - 0.1 10. f 00mA

3.b — ]SOMHZ

IJ — 3-T

0 — 20. ZOO JOOOW i 10%

, Drrettional coupfer unJt \ftHth felev'itnl;

conrtectof cable, i^i leads and i:>aiEe*y

, AW'iWl Jt 6k^"JH} X r\Dl: Multimeter

*WW\ * 2W'(H) >t 21D|: Coupler

T.06 IDS \480 gr^rtisj- Multimeter

0 75 lbs [340 gramsf: Coupler

Frepuercy Cavtisgc

RF ftjywf r Range
Acceisojy Jnclyded

DrmefiiicHni , ,

NeE MWighi

SWR A POWER METER FOR HF/VHF BAND
MODEL PM-IHV 140.

High qualJty S'^R/W^n rnetet devigned ai SWfi srwJ power ian
be meaiurecf independenrf^ at a tune With meter ilJurfidnation
and "O'hEf'iif-A/r" jndnjitof J^mp.

SptcHlcatlorif!

Freqijt-rKy Ct^vefiig* 3 — iSOMHi

Hf Ftower Range . . 0 — ZO. 2O0_. (. DOQW. 3 rAn^es ■ 10%

accuracy
Power Source , , . , 12V AC/DC (for nieter illurnination onfy}
Accesicny fixfuded .... ?fi. long connector caois with fuse

for meter iPJurrnndtiOra purpose

Dhmensiom , . TiW\ k 3"^HJ x 3k>lD|

Wet Weight , _ . , ...,._ I.S ijm. fO.e kg5i

SWR « POWER MriER FOR HF/VHf BAND
MOOtL i»M-4MV . . S30,

Compatt and' Jr^fn weipfit SVt/H/Walt merer designed For
rncsiD-iie operation as H^fil as bAse ilacion yie

Stptcrffcjrtlonts

Frequerxy Co^/er^ige ..,.;._,.... 3 — 150MH?

RF Rovv«r ftanije . , 0 — 20. 200. lOQOW, 3 farigei t 10%

accuracy

Accessory Included Velrro double Dack adhesive

rTBuntjng foe rmotnk- irftijtiJJairDn

Dinwrnnons fi'iwf ^ 2W[Hf x 2Y?"\U}

Net yyeight 3 ic ^0.44 kgi)

MigH by? AKIOAHH ELECTRONfCS COl^l'. ■ Exduilw INltHbvtVfi; AkCAW ELECTRONICS. IliC. > P.O. Bo4 «4: C^riilhMl. CA 92^6; l*tt0ME jTf4| 434-107^^ lELEXs 111743 MACAHrC£BJ>

i^ 56 Prices do no[ wtciude shipping and handling and are su&jecl (o ehflrige wilKui rvHif.*

CALL NUMBER ONE!

CARLOAD INVENTORIES • ROCK BOTTOM PRICES

SUPER-FAST SERVICE

LINES: AEA

ALPHA

CUSHCRAFT

DENTRON

KANTRONICS

MINI-PRBDUCTS

NYE

TEN TEC T^

AVANTI

BEARCAT

COLLmS

HY GAIN

KLW

MOB GAIN

PALO MAR ENG

UNIVERSAL

ASTRDN

BIRD

COF

HUSTLER

KFNWdOD

MIRAGE

REGtNCY

UNARCO HOHN

ALLIANCE

BENCHER

DRAKE

icaM

MFCROLOG

MFJ

SWAN

VIBROPLEX

CALL TOLL FREE 1-800-325-3609

MID COM ELECTRONICS • 8518 MANCHESTER ROAD • BRENT

hf%g% IN MISSOURI

Wif 314-961-9990

BRENTWOOD, MO 63144

148 73 Magazine ■ February, 1982

Introducing

*'21

YOUR OWN
AUTOPATCH FOR
OPERATION

Mobile Connection

ONLY
$14995 KIT

Wired and Fully Tested

$199.95 •Shipping $3.50
inU.SA -N.Y.S.
Residents add appropriate
sales tax

Hundreds already in operation • Call anyone— anywhere— anytime

NOVAX interfaces your standard 2 meter; 220; 450; etc. base station and DTMF
(Touclitone) Telephone, using a high speed scan switching technique so that you
can direct dial Ironn your automobile or with the HT from the backyard or poolsrde
—automatically. Easy instaflation. Ringback (reverse autopatch) option available
for $29.95 kit— $39.95 factory wired.

• SMALL SIZE- (5" tc 6" x 2")

• STATE OF THE ART
CIRCUITRY 12-16 VD.a

• ADJUSTABLE ACTIVITY TIMER

EASY INTERFACING with radio audio
& squelch circuit

SINGLE DIGIT CONTROL
(connect and disconnect)

(clears out if mobile is out of range) • 3 MIN, CALL DURATION TIMER

TO ORDER— SEND Check— Money Order (MasterCard or Visa accepted) to:
R.WD. Inc., Oriskany N.Y 13424 or caH 315-736-3087

CABLE TV

•iiJ^PJWIlT^rK

AND OTHER ^9,

GOOD STUFFr

SMASHING ALL SALtS RECORDS •• OUR NEW
30CHANIVEL CA8LE TVCONyERTtR!

P^hiMHTi mid & tM:t^i
bana lEiblB ch^n nsis

TV wV

Ni 354Ata*7

i;:t4 ii^li

HOT NEW IMPORT! REMOTE CONTROL
30 CHANNEL CABLE TV CONVERTER!

a-^ i' 6

174.95
*B -ID

v^fofi swclch anfl

ETCOMKII WIRELESS -

TNi ULTIMATE CABLE TV CONVERTER<

Ha. l^-iATAMi

lOO

VIDCOR 2QO0 CONVERTER ELIMINATES PROBLEMS
WHEN VIDEOTAPING FROM CABLE TV

M:aii-i i^mOLH i:hdr:llHl a: II
fCII. £:kdlil^J .i|1i:iilSi|llJlU!

fjl' i^ne- LUA'iii |iiu[|r«iii
fthtlt ^va■cilll'><| 4n.i:i|hijii
Mfi 3B4V*i95Cl

ViEKOR

2000

UNUSUAL FACTORV SURfLUS
MIOBANO ^ SUPER BAND CABLE TV TUNER

cnrtwnun If lrfi|U(f!ei,v Exfr"-
men rers tm M c*i^p ^mi-.-,-
Egr^, Mindimt!'! i:1£ Willi
MrfimnauL Nd.- 3MVA34Z-

' ai ) ii(i
in

FACTORY SURPLUS UHF TUNERS

BraniJ nifi* pmcJuctton Surfihii
ik\- s^litj 5-tace \i\ra\ icn esper
iiTi*ntil vAirM. bu.ld'nfl. -rahti! TV

MINIATURE FM WIRELESS MiCROPHOfVE

BRCVID B/4ND
FOLDB> DIPOLE

BARKER &

WILLIAMSON'S
MODEL
370-15

^ 11

B & W's Broad Band Folded Dipole covers all amateur
bands including the new 12. 17, and 30 meter bands.
Also covers CAP frequencies, MARS, Military or any
frequency from 3.5-30 MHz- Being used ttirougtiout the
world! Total length only 90 feet long— spreader spacing
19 inches. SWR— less than 2:1 from 3,5-30 MHz. Rugged
construction for long life. Can be installed as a flat top-
inverted "V" or sloper. Also available for 2-22 MHz.
Power handling capability 2 KW-4 KW PER Supplied
completely assembled with RG 8 type cable with SO-
239 connector Terminated with PL-259 connector on
each end. Patent Pending.

Price $149.50

Cable available in the following sizes:
25 ft. $18.25
50 ft. $26.00
75 ft. $33,75
100 ft. $41.50

Barker & Wiltiamson, Inc:

10 Canal Street

Bristol Pa. 19007

Phone #215-73a-5581

MHtwCCII«d

Hidn in the palm tjT yw
hand Bf!;*5]C,i>n (iiian^ Esar
rijnj FM facfioor r*cei^€i .

QUARTER-MILE WIRELESS MICROPHONE
& RECEIVER SYSTEM

hue dhUWiKa'vil liV^I'i' :.Ll-Mllllll'Hi

wirplfc»trti>^!t'& TNli*iV'i< ^11

IjialUtry l)n^l.;«(QII. CiHCtl-Fl M 11 Ih

FACTORY SURPLUS VHF / UHF
TWIN" VARACTOR TUNERS!

S27 SO

Bff A^Cl -hJEi^' UiriiH! I in liiiMih"^!
r,r k4<|ig> I i iv^ i;i|'rlhiiiin.;tHly liiliinl
TV f^MNl f ';r- ■ ■' iijiiil ([I
'I'll I irftm ^|.M ^^ ptii fli

Nst ssdvcaoa

DUmnnGS NORELCO ENDL£SS LaOPCASS£TTES<

5f34.g€

I mposiiale to Krifl it ahv
prji^e!

e iflinutBl - No 354VA6a$.

Ty5^

£SS!

m STOCK - THE MURA
CORDLESS TELEPHONE SYSTEM I

..I I...?.- 1 ^ ■;■■ i:m III '■
^^Mt V¥«in I 111', vr.--

leu pacAi^'ptMiif
400 ft rriB*' flA

niim^ci '<;r,^ii ^.jij-
'IH iri^lillKi Uut;^Ar:l*-
■riJi','. i.-'ji-Cf'tvirj-ro-

Mo. a^VAllA

SALE Of QUARTZ BATTERY-
OPERATED CLOCK MOVEMENTS?

£\ p icr-jiacv :-' f iV.i • .irM ii|i

r ^ jiiui "f! ' im;II ItriliuiiH"! 'rwn
Sa.e& '^^JiKi Gfe^ri^-sv Wo 3&aVft531 ^

*•' '' 1"^VA565 Wl&ltchni^ H«Mft ^A^iifU.

S12*.*i

311 AMF» REGULATED 12VDC POWER SUPf L V f

"■ 3g4tfAa95 aa fllj^^<. TS H>"R«

n tt ,1^ II MiY <• I^LI I ? 5 .41L Ik.ll

H)#!l %t^:.\t i'a\'iiMe' liiiitl.iTff'ifii"
rixii I lie :Hli(l. SSB I " i^i J ■ '
-4130^ PEP -Br^ixf fte-ir ■ : -
s^viiipi I r r?'i V AC. Hij 11^4 VA ;-ni'i

i:ii B

OUR LATEST ^ PACE
F ASC IN A TlfttG CATALOG

■ I-

\mitAum'4ii I"

EtCO ELECTRONICS

NOflTN COUNTfiy 5H0PP<NG CENTER

fl-ATTSBURGH. N V 12401

Ch9(* wnti o«ihi. pteaw Vis** IWfliwfcaiu O-K •!;So<iri '"S C 0 Cf * Ana tSi
for UP3 f^ HandMfni(i:Jie*+rrn1iiiiiiodi Sj.V Sl-ii^ rfliidums iflri ? TB|H^ [hi
OwaUp Bi iKptjuP inquirmi .ii»ilHi1. Oyi ii.'l*jj|i,unr utik-r ilMt \in<(nt diihij

copy RTTY, ASCII

and Morse
from the palm
of your hand.

Have you waited to get into
code reading until you found
out what this latest fad was
about? You can stop waiting,
because it's no longer a fad.

Amateurs everywnere
are tossing the gigantic
clanking monsters of yester-
year that once performed
the job of reading
radloteletvpe. They are trad-
ing them in for state-of-the-
art code^readlng devices
that are incredibly small,
noiseless if desired and in-
finitely more versatile than
their antique predecessors.

Kantronics, the leader in
code-reading development,
has just introduced the latest
and most-advanced break-
through in the copying of
Morse code, radioteietype
and ASCII computer langu-
age.

The Kantronlcs Mini-
Reader reads all three types
of code, displays code speed,
keeps a 24-hour clock, acts as
a radioteietype demodulator
and reads all of its decoded
information out on a travel-
ing display of 10 easy'to-read
characters, it is so compact
that it fits in a hand*held,
caicuiator^size enclosure.

At S289.95, the Mini -Read-
er outperforms anything
within another S400 of its
price range.

Call or vrslt your Authoriz-
ed Kantronjcs Oeater now to
find out what the latest in
technology has done to
code-reading.

I Kantronlcs

(91 3) 842-7745

1202 E. 23rcl Street
Lawrence. Kansas 66044

1
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I
I

W^BW^i^BpBp

IMPROVE YOUR
NORSE SKILLS

WITH THE

MODEL KT-1
KEYER TRAINER

FEATURES INCLUDE:

• PRECISE SPEED CONTROL

• 24,000 CHARACTER PSEUDO-RANDOM LOOP WITH
10 STARTING POINTS AND FREE ANSWER BOOK

• EXCLUSIVE AUTOMATIC SPEED INCREASE

• RANDOM PRACTICE MODE

• OPERATES FROM 12VDC

call or visit

AEA

Brings you the
Breakthrough!

DERRICK ELECTRONICS
714 West Kenosha
Broken Arrow, OK 74012

TOLL FRFEE (800) 331-3688

USERS
IT'S

M^ ENGINEERINGS' NEW

HANDI-CON V

^''tft

Are

HJieiQ wo? IHtl

•ANY FULLY SYNTHESIZED 2 METER
H T CAN NOW BE A COMPLETELY

PORTABLE VHF-hi MONITOR
•2400 CHANNEL CAPABILITY
•DOUBLE BAND COVERAGE

154 -ISSMhz fire,police,sheriff,

paging & more
159 - 163 Mhz maritime coastal ,

railroads. N.O^A.
weather & more
•MULTI-BAND & MULTI -CHANNELLED

MONITORING WITH SCANNfNG H T/s
•SINGLE 3-POSITlON CONTROL

• "OFF RETURNS TO NORMAL TRANS-

CEIVER OPERATION

• LOW LOSS COUPLING TO ANTENNA

• UP TO 6 MOS OPERATION UNDER AVG.

USE WITH A SINGLE AAA CELL

• Bl -LATERAL PROTECTION AGAINST

ACCrOENTAL TRANSMISSION FOR
UP TO 5 WATTS

• size 2 25 5t 1 5 xT4 inches

• wejght - 4.5 ozs.

$44.95

+ S2.50 pstg. &hndl9.
in Calif, add S% s.tx.

I
I

contact

p^n

M SQUARED ENG.
1446 Lansing ave,
San Jose.Cal 95118

' Of -

Ph 40d'266 9214

Pfease write for cfyb discounts
on quantity orders

150 73Magaiine • February J982

look here

call toll free:njghts
1-800-231-3057

6-10 PM CL M.W.F.
days 1-713 658-0268

ICOM IC 3AT/IC 4AT 269 00 ea

IC 25A 309.00

IC 730 729 00

IC 2AT 249.00

IC 22U 269 00

Santec HT 1200 269.00

ST 144UP 299.00

1 0% OH Ust on Stock Items

Tel rex
Drake

» « P -M «■

^ * *

, . 995 00
. 1 299 00
,,169 00
.,11500

. 1 00 ea

Call

24 95

749 00

67500

.699 00

.159 00

TR5 . , . .
R7/DR7
AEA Morsematic.
CK1 Contest

MBA'RO Reader . . . 269.00

Order KWM380.. $3095 00

Si 2 Free Frtters

High Serial Numbers, All Mods

Ampheno! Silverpfate

PL259

Antique rare Tutjes

TJm«x 24 Hour Wallclock

Robot 800A ......

400

HalC!2100

KB2100

New CWR 685 A Telereader .875 00

Cubic 103 1195 00

Bird 43, Slugs Stock

Drake Theta 7000 995 00

Belden 9405 Heavy Duty Rotor

Cable 2#16, 6#18 45C/ft,

Belden 8214 RG S Foam . . . 36C/ft

Belden 9258 RGSx Min(-Coax19C fi

Belden 8267 RG 213

Non Contam Jacket 43C tl

AlHance HD73 109 95

Large Bookstore

10% OH Curtis, Sherwood: Palomar

Call Quotes Kenwood TS830S,

TS530S. TS13DS, New

We Want Special Orders^

Yaesu Specials
New FTI

FT 707 . . ,

FT 101ZD Mark 3
FT 208R

MASTtRCAftD VISA
All prices fob Houston «Hc«pr wfiere imjicated Prices
subjecl lo tf^an^e wiT^oui noifce. all nemsguaranieed
Some Items sub|9Ct pnqr sa\v Texas res4<^nt5 ddd 6%
idi Pi«fts# add suHtci^m pf7$ia^, balance cnlfieet

2395 00
649 00
749 00

289 00

Electronics Supply

"« 1508McKinney
Houston, Texas 77010

Lacue Likes You . . .
and you'll like Lacue

WIRE AND CABLE

^ G-2 t 3l ir r — ■■— ■■ ^jTZft/f 1

RG*U roam 95% stii«l« . — 23 St/*1

^ G-BX foam 95 % %hmtQ — 1 1«Ht

RG SaCflJ m,l spec — tleih

R G Sd mt3 spec ^ ^ ^ Bull

RG T % — iSWfl

i 50 ohm Taddcc I me 1 00 »T roil- SIQ 2S

B-Cortductw Hoior Caoie — — iStrtT

t<G* Stranded Coppe'iM'f muiiiplesl- Ttlft

tlGa &o<HdGoppemeidiSOil mufltplcs) 7tlft

tJGa Solid Cop p«f weld (50 f( ms»llip(#«— — Strft
SGa SoikdAmminum 15011 muU^plMSi" — ^ — -^ — tttltl

ANTENNA ACCESSORIES

Ceramic Insu^aiors - . iii i- 45* ea

A mp heno I PL- 259 - - ■«im»».i»wi — — — -75* ea

Van Gorderk" — ._,„,_„_„„,g|,|yn,.. 17 50

C*rtle^ lr^»U^ ■^-*— -1 — %A 60

W2AU B3fun i 1 or I 1 ^... $13 25

B4W Traps 40 Thru tO -'" -■ '—tfi 65 per pair

8&W Traps 80 thtu IG- -—'■■'-'•"-'■"■■- $25 65 per pair

ROTORS

CDE HAM 4 — " .„...,.™.^-_ tlS2 95

CDE CD 45^-.^-™" -^ —'■ — S B9 55

CDE AR Z2 " * 48 95

1962 CALLBOOKS

us. version .$14.95

O'X vfifSion — . $14.05

ALSO AVAILABLE

Cusftcrad. Hy-Gain f^l^i Bencher Bullernui i%egenc)r

Mint Prod ucls.tarH»'n SAvy Huflle'r Shure ARHLStrd.

CaltbQDli Affieco Sams f^j&iicalions FU>nfi Vibf<rpiei

Ham Key. Vocpm Dnwa arnl manr more

Pffcea S4jb|ecl lo ch#r*ge *k!hou1 nor»ce

Hours Mofi — Sal 1 0AM — 6PM Tum% * Pn tiJ 3PM

Teiephorte rei4iS3fr^500

mOJE COMMUNICATIONS ELECmOMCS

fOl Vlkir Sinn ^

Jol«towii. PA i^fn

SMP 2300 MHz

Now Order Toll Free!
1-8QO-368-3028

pfTC nn*'^

Ty,S— 44.95. Deluie Tunable PS. Very
smootti tijniing MIL SPEC pat S-ISV
Complete,

UCC-1— 35.00

2100-2500 MHz
components

DownconveHer Kit.

Quality board and

SMC-2^50.00. Deluxe downconverler

kit. Wiiti tiigh gam RF franststor and
lemperature compensation

ft FA-1— 44.95 2 stage RF preamp.
Selective filter 16 db nei gain.

large SASE brings catalog ot kits and
parts and the 2300 MHz slory

Aii prices postpaid m U S.
VISA and MC accepted
In Vtrgfnfa. AEaska and Hawaii
Calf 703-255-2918,

,^376

SMP

Superior Microwave Products, Inc.

P.O. Box 1241

Vienna. Virginia 22180

INTRODUCING THE

CES 500SA

SIMPLEX

AUTOPATCH

The First Affordable
Private Phone Patch

As dtscribed In 73 Magazine. fi/SI.

Now. for the first time! Every amateur
operator car) enjoy ttie urjparalletied freedom
of a private ptione patch m an economicai
package.

The dramatic new CES 500SA Autopatch is alt
the eQUipment you need to patch an FM base
station to your home or other telephone line,
without expensive fepeaters. cavities, or other
equipment Cctfifiections with any standard
FM base station are rapid and simpte.

Bypass the congestion and expense of shared
repeaters — break through lo greater privacy
and convernence with ttie new CES 500SA
Autof^ch.

COHEREI^E IN
COMMUNICATIONS TECHNOLOGY

CES

COMMUNICATIOHS ELECTRONICS
SPECIALTIES, Inc.

PO, Box 507

Winter Park, Florida 32790

Telephone: (305) 645-0474

^462

See Lnl Qf Advertisers on page ii4

73 Magazine • February. 1982 151

rfb

MHz MICROWAVE
DOWNCONVERTERS

DOWNCONVERTER

Kit

Assembled

2300 MHz PREAMP

Kjl

POWER SUPPLY

Assembled. . .

¥ T •

.... $28.50

$48.50

. $25.00

$35.00

2300 MHz
ANTENNA

w w >&■

SATELLITE TV EARTH STATION

• 24 Channel Receiver

• 10' Antenna

• Dexcel 120° LNA
Call for details and price

Also AvaHable: Connnnercial System with
Bogner Antenna .............. $169.00

WITH BOX
FOR DOWN-
CONVERTER

$27.50

PB RADIO SERVICE

1950 E. PARK ROW • ARLINGTON, TX 76010

t^ 404

CALL ORDER DEPT. TOLL FREE

(800)433-5169

FOR INFORMATION CALL

(817)460-7071

RTTY/C\A/

A Trajdemark or the Tandy Corp

R0MH6

RTTY/CW Operating System

Detailed brochure available on reQuest

Featuring:

1200 BAUD OPERATION. Not limited to 1 10 baud be-
cause ot timmg loops. 60. 66. 75 & 100 W.P.M.
Plus 110. 150, 300. 600 & 1200 baud operations
possible

FLEXABIUTY OF DPERATIOH. Instantly change: Baud
Rates: Program Mode (ASCII/baudoi}. Program Status
SPLIT SCREEN VIDEO. Transmit & receive data dis-
played separately

HEAL TIME, Automatic CW/ID without user interven-
tion. Aylomatically updates \^^^
at end ol month or year ^^S CROfdCI

nicroPiodiicts

Other features
include i

• Two Serial Ports
Fourteen Buffers
AuiomaticCWID
Transmit Control

• Selective Call Feature

• Error Corf eclioti

• Wora Wrapping

• Easy To Interlace

• 30 Day Unconditional Guarantee

• Hardware requirements. TRS-SO

Model tor 3 16K
Exif rnal termmat unit.

606 Slate Slreet. P.O Box 892-R • Marysvdle. WA 98270 • (206) 659-4279

BASSETT HEUUM
MOBILE ANTENNAS

For

Commercial, Amataiift
and Government Services

Rugged, low drag, high efficiency
mobile antennas engineered to
maintain resonance at all times.

Maximum overall height of qnty
70'. Averaoe weight of only 6 oz.
They remain vertical ai all ^seeds.

Hetical inductors sealed in helium
filled Fi&erglass imperviousloaH
weaihef. Adjust able i7-7ph whips
and solid brass hardware chrome
plated and polished.

Optimum gain colllnears for VHF
and UHF. Unrty gain models for HF,
Amateur band models are mveri-
toried for "off the sheff delivery.
Commercials to S|>ec3.

Write or phone for free brochure
and prices on Bassett mobiles and
Helium Trap Antenna Systems.

REX BASSETT

ELECTRONICS, INC.

1633NE14thAve..Btdg. 11
Fi, Lauderdale. Fla 33305
Tel: 305/561-1400

-iho

ace N, Mitn
Evans vlllfl J N 47711

TENTEC

546 OmnhCXcvr $1050

580 Delta 750

525 Argosy ^BQ

280 Power Supply 150

255 Power Supply/Speaker 1 70

243 VFOOrnni 169

283 VFO Delta 169

234 Speech Processor 125

ST-144/;aP

SANTEC

call

AEA MBA Reader 275

ALLIANCE HD73Rolalor 99

AZDEN PCS-SOO 2m Hand HeW call

CUBIC Astro 103 1175

DAlWACN5lB2,5KWTunef 255

HAL CT 2 100 call

HY-GA!NTH7Tn band Ant. call

1COM25A 2m Mobile 309

ICOM 251 A 2m All Mode 625

KANTRONICS miniReader Package 259

lVlFJ496Kevboard 290

MFJ 722 Notch/CW/SSS Filter 59

MIRAGE B3016 2Tn Amplifier 206

812-422-0231 -*«

mU-f^l 9AM^6PM • SAT 9ilW-3PM

jflff'tm tOF (Jut nf * ^ififl uSiPC v

SYNTHESIZED

SIGNAL GENERATOR

MADE IN
USA

MODEL
SG TOdC

• Cowers 100 !o 179 999 WH/ ifi i kHz steps with
ihumtt wtteel diaf • Accoiacy 00001% al all fre-
quencies • iniemai ffCfluBncy mocfulation from 0 to
over 100 kHz at a 1 ft Hz ra!e • Spurs anif nctse af
least 60ilB below carrier • RF ourpyt adjustable from
5 SOOinV across SO ohms • Operates on t2vdc #
Vt amp In stock tor immecfiaie shippiirg $3?9 95
plus shipping Overnighi delivery avaH^bts a! extra
COS! • Range txtender (phase-focked mix&r/divid-
eri lor above unit Extends Hie range Irom 1 to 580
MK? Same size as SG-100 Mounts piggyback
f I e 1299 95

*^311

VANGUARD LABS

imr2^ J»m«cia Av».. Hollit, NY 11423

CB. TO 1 0 METER KITS

AMElfCA*S # f SOUICi FOl
FM — SSB — AM

IN STOCK— Kits for rrroM C.B. Modeb

NiW— 1 0-meter FM DiscriminatoT Board

—fits most PLL rigs. Kit— Assembled and

rested.

NiW AND USID— FM S. SSB converted

C B.s now In Mock — from SQO,

LOW COST— Prices range from SlO

to S50.

ORDER lY PMONi— f6l7> 771 46B4

VISA 1 MASTERCARD— accepted

IREE CAT AlOO— write or call todayf

AMERICAN ClYSTAl iUrPLV COMPANY
P.O. iOK 61S

WEST YARMOUTH, MA. 0267 J
(«17)77I'4«S4 ^^

CB TO TEN METER
CONVERSION KITS

KITSforAM— SSB — FM 40 Channel PLL
chassis conversions
DETAILED rNSTRUCTIONS for easy In-
stallation with minimum time and equip-
ment

BAND COVERAGE ftexibillty provides
up to 1 MHz coverage for most PLL
chassis,

PHfCES Low cost prices range from
Sa.OO to $50.tX)

All kits are in stock including
several different FM kits,
FREE CATALOG Write or call today.

-^TB INDEPENDENT
CRYSTAL SUPPLY COMPANY

P.O. Box 183

Sandwich, Ma. 02563*0183
(61 7) 888-4302

THE PROFESSIONAL

TOUCH TONE

ENCODER

' ^^^ ^^ An urtra high qyallty

encoder for professional
application. Absolute refi ability and
function makes the difference. There s a
Pfpo encoder for every system and
application. Totally sarviceabte, easy to
opermXe and Instalf. Ca// or write tor free
catalog and informatsoni (213) 652-1515
or P.O. Box 3435. Hollywood. CA 90028,

PATENTED - A TAT

^ipocgommunications

Emptia$t& ts on Ousiity & Rensbtisry *^ 300

AMP LETTER

imp LET TERJ f».
put^Hcacfon devot
t i an f a R^ opera 1 1

? . A rrewsl et tsr t

you IT next ampl 1 f1

The mp'llllin \l
Clflin ev^ry three
It i i orgflfiized I'

1 Cdf tor's Corn

il Letters

1 1 [ J^tn Topics i

IV Feature ArtU

t AWP-LETTER |R

I , An Anateur R»d{<i

ed tD th? d^itgn, ci>nstruc-

on nf Amateur jjn jj^ i" f f e r 5 .

hat can save ^^u mprty tjti
(jf constrirctlon project.
rt% and information.

pubMjhed and mafled Ftrst
weeks (17 t ilne^/jreir) .
13 to rive depir imtti'lLS -

Hive pif Is to se^ 1 7
Run mil id in the
*IIP-lftTEft TRIDEft.
Subvert titr rate \%
l^t p*^ (word.

Tfie AKP*LETTEFr believes that hOfttbrewfug
^n antp can be fvif^i ^ducat 1 dPta 1 * and hdlf
t% costly as buying i co^fperdal amp^

A ore year subscript tQti to the AHP-LETTEfi
i5 JlB.OO/year (1? issues). Mention "73"
Napaf7fne and >ou i!ia> subscribe it the spiclat
one time rate of SlS.DQ/year

mH*J m\%^ A SINCLC ISSUE OF

AHP-LITTEIt
RR? tox I9A
T**cnnpso"iif ^ Tie

^ 97

THE

a«p-le:up

Place An
ad, ICC/norrf

Send l^.QO For ■ ^inple c
for « fgH year of t

or StS.OC

PILOTS :

^ ^

ThB RST-*42B voice actuated inter-
com iS59 50i ts tust one of o^er 20
exctfing avtonics kits from Radio
Systems Techftology. Test gear too*

FREE CATALOG

Caif folf free outside Ca/^/om/a

e24B97e *

OTHERWISE ■

ate ->. J

2722203 /

Radio Systems
Technology, Inc.

-~«a£afeG-«flASS VALLEY AVE
GRASS VALLEV. CA 959i5

QUAUrr MICROWAVE SYSTEMS

2100 TO 2600 MHz ANTENNAS
MINIMUM 34 db GAIN OR GREATER

Complete Sy&tem ai pictured $149.95

(6 month warranty)
Down Converter (Probe Wnld-J

wsembifrd Ir leiled $59 §5

Down Convertef (Chassti Itlnd.)

assembled A lesled %S9^S

Powef Supply, aiiembled ft teifed $4S.9$
Down Converter PC board.

with pans, unasMmbled A Data $39.95
Data Information (Plans) 19.95

Send cash, cheek
~ or money order to:

Phillips-Tech

Bectronics

Dept SP-73 ,>H.42i
P.O. Box 33205
Phoenii,
Arizona 85067

for tp^clat qusnttfy

pricing. CCD/t,

Mmterct^arg0,

ana ViSA calt:

{6021 274-2885

FINALLY. . .

A SQUARE DEAL

ON YOUR

ELECTRONIC

SCRAP

il/rtnv "hrffkftv' pay flat rutv% nn ni'ffip, not
payment tm fhe value Gfyourmattriat.All
mai**rml sp^i/ tn uh m mdwifiuftny rvfinvd and
iimayf'dfor mtixtmum retitrn Takf a. htok at
urtmi" fypiraf ywifh

PC Boards
Connectttr*
PC Fingrrv
Gold fHOttd pin^

SOC to$7ftt^rfh.
$l2i**$5npfrlh

Far further mfttrmalton, ctrvtt itur frader serriae
nttm hfr or catthtrtrr

/r^%.

^^Q

ELECmomC REC YCLERS
OFMAmjNC

263A S. Main Strret. Box €

Middieion, Mum 01949

TnU Free fSOO^ 343-8308

In Mass, (HI 7) 7770455

WEVE GOME NATIONAL

Strux Corporation manufactures and
distributes National Radio, Inc. Com-
ponents: Chokes, inductors, coils, and
hardware. We also distribute fixed and
roller inductors, contactors, mU-spec
and designer knobs. For all your elec-
tronic needs, contact Strux Corpora-
lion. 100 East Montauk Highway,
Lindenhurst, New York 11757,

ISTXUXl

CORPORATION

100 EAST MONTAUK HIGHWAY
LINDENHURST. NEW YORK 11757

S** LfSf of Aitvmrfts^fs on psg^ f f *

73 Magazine • February, 1982 153

If s Incredible!

OD£.qui!c«c

Now You Can Master Code * • .

For your fif si ham license ch yp^rad? m 4
maftwofdays CODE QUICK 1^ a fi^K>{Ll

iionary bneAkihrougK cbscowry which dr^s
ttcalty sifnplrfies the Naming ol Morse Code
Oort'r torture vourseH wilh an pndWss rmue
g| diis and dahs With CODE QUICK each
tetter magHiaUy calb out its own nanw* Your
amazirYg kit Lon tains S power park^ c*5
&pttes. visual breakthnxigli carafe, and nrig
inal manual s^ridSl?^ today to

WHEELER APPLIED
RESEARCH LAB

PO Box -1261
Cnv of hdustry, CA 91744

Ask for CODE QUICK ftl03

(C^lif add 6'm salps T^n.t

Even if you have failed b*?foTe CODE

QUICK must work for you or return

the l<3t for total immedtal^ refund!

DiREcnon

FINDBHG?

New Technology (patent pending) con-
verts any "^H^ FM receiver into a
modern Doppler Radio Direction
Finder. No receiver mods required. See
June 1981 issue of 73 for technical
description. Kits available from $245.
Write for lull details and prices.

I DOPPLER SYSTEMS
/^ 5540 E, Charter Oak
Ly Scott^dale, Arizona 85254
\ (602) 998-1 151 ^425

GO MOBILE WITH YOUR H.TJ

NOW FOR FT-208R & TR-2500

*^ unique battttry etirtimitof *

HANOI-TEK ReQui^tof allows centtani h«n^l>«ld

operation Uom auto OC or biM supply witi^ no ni-

ctd drain «r>d WITHOUT RAD»0 MODIFICATION!

Modvl I— Icom 10-2 AH; K— TR 2400; N~FT-20flR

Y— FT'207R, T— Simp!* mod ^Of Temp

124.95 PPO In USA. CA add Si 50.

*^460

HANDITEK

P,0. iOX 2»$, LA PUENTE. CA >ir4i

Icom—s lidos on bottom of rtd'o
Vaiflu^hts into t^ativry compartmttn'l
Kenwood— povtrefed tt^ru batta^y plug

C:ERTIIIFJ} INTl-RN \rKI\AL

"rajHULL BE tti_AD ¥ouc»ecped BfiTM MI rim

QtfHCRMFT AMD mJET^ER fMl hh* n ?fi% of l] . LARSEN,

FALOMAft. NtE VIKIHG. TlllOifVK, TUAC JAIff L
•EMCHER. VlBflOTLEJC AlM4£l«OL GOULD ttCiLEN.
EVIIIEAJ^Y AND 0THERS

we IFOCK EVBTTKINDOF WiRE TME AMATf UH f«E£IK
BY 9EIL0EK Q^^Pi

CRTtTAU F13ESM CUT TO TpOH ORDtR tftCW HJ6

QSL'i. CUSTOM Hhm, lOE VOtJ

Ol TO 10 INEftn COIfVF^IOiyS FRCiM the STil.f«pA1IEl STTTEfl

CERTIFIED COMMUNICATIOIMS

j^a^l Wf COM ^EflT OVER 1 WliRODELSlil^ ANP U^
^^""^ AMD SELL NEW 10 METER flIGSWFTftOOyBLf
WARRAMTY F RDM Si 76 00

Al(t fOA 4WCFTE, I:ATALDG, CON trE AilQ«4 flDOKUirr.
OIL UUPLES 4IMCLUDE 549 BnnJ. OH PNFDAMAr»Of«,

WE BHfNO OUR STORE TO VOU AT OVER 70 HAMFESTB PER VfAR.
set VOU IN SOUTH BEMP< AH LIWGTOJ^ H EIGHTS AND WiST ALLIE

TS WOfffH 1^Di/l? tW^tf TO CALL Oi» Wfl/ Tf

4141 ii»umf«Trfl, 141*1 aj**5it *liwi»ii>il W( 4MTJ

fHEHMRiri_

MICROWAVE RECEIVER SYSTEM

24* dfl GAIN * TUiASU Zl TO 36 &Kz RAIIGE

i nOilll WAMMTT • CPiniTlirEADr TO IM&T All

PIRTS OF HMR H AVAlUMi SEFAHATaf

$139S^ACM

SEND CHECK MONEY

ORDER 01^ CERTIFIED

fUNDSTO

HMR

POeOX440fi5a* AUt^OflA

COLORADO aD(H4

DEPT MB

fOflTHE LOWEST PHICE ON QUAMTITTOHDEItS.
COD». MC OR VISA ORDdlS CALL

^9 QOat 620-0736

FOR THE DO'lT-YDURSELFEfl

DOWN CONVERTERS

PC0 PJIRTSAFUHS W

PLANS

POWER SUPPl*

WITH CI an:^

PCa PARTS CiSf 4 PLUNSaq
tail

S-LINE OWNERS

ENHAMCE YOUR INVESTMENT

with

TUBESTERS

Plug- in. soltd it^e lube rcptscmnenti

• S'tine perform a tiee—iot id stattt
* Heat dissipation r^cfiio^ 60%
• Goodbye Nard-to-f ind tubes
• Unlitnited equipment life

TUBESTERS cost Jess than two tubes,
and are guarantBed for so long ^% you own
VOurS-IJne,

1^433

^■^^^^^ Write or phone for

Box 535 jpecs and prices.

Talmage, CA 95481 (707) 462 6S82

You can pay more —
But you can't get more!

RtodeMLiieK
$839

Model III 4dK
I disc 8e RS232C

$2100

immrn^

Color Computer 4K

$310

w/l6KExt Basic

$459

BUY DIRECT These are jus! a law d1 our great
oflers which include Printers, Mudsms. Com-
puters, Peripherals, Disc Drives, Software and
more, c^ii toll free 1<OOIM4S^812«

Wb have the lowest ^ 444
possible fuHy
WMTantBDi} prices ^'
mtf I luH complement ^reecaraloq
*a Ml **. iTr. t» 245A Gfeai Rood

Ol Radio Shack Software. Litne^on. MA 01*40

617 • 466 * 319 J

comp^fBT

te for your WiUS^

o
o

Q
O

YAESU FT-207R OWNERS

AUTO SCAN MODULE AND BATTERY
SAVER KIT

15 minutes to in-
cA m^^^^^M stall: scan restarts

when earner drops
ofL busy switch
controls automatic
scan on-olt: in-
etudes module and
instructtons.

Model AS- 1. $25.00

lt%^ FT-207R BATTERY SAVER KIT
Ijk^ MODEL BS-1 $14.95

'No more dead bettefies due to men^ory back-
up

'30¥s 1^3 s power drain when squelched
*SiiTip](3 to Install, step-by-step irvstmctiona
and parls included

'd mA memory backup reduced to 500 AA.
•45 mA receiver drain reduced lo 30 mA
'Improved audio Tldetiiy artd tcudness

ENGINEERING CONSULTING

P.O. BOX 94355 -'^^^o

RICHMOND. B. C. V6Y2A8. CANADA

Subscrwtion
PrdbLSvi?

73 MagaiifiB does not keep subscrip-
Iron records on the premrses. Ihere-
fore calling us only adds (ime and
doesn't solve the problem.

Please send a description of the
problem and your most recenl ad-
dress label to:

73 Magazine
Subscription Dept.
PO Box 931
Farmlngdal«, NY 11737

Thanli you afxj enioy yout ^ytiscnption

154 73 Magazine • February. 1382

ETCH BOARDS FAST

This Power Etching Svstem will
handle PC boards up to 6" x h'\
The pump keeps acid agitattng for
faster more even etchmg

Send $34.50 plus $3.50 for
postage and handling to:

STEILMAKER ENfERPRISIS

250PEQUOT TRAIL

WESTERLY R 1.02891

^32

MICROWAVE
DISH

24" True Parabolic
Reflector

12" Focus

Made from .050"
Spun Aluminum

Approximately
21 dBi Gain

$18.95

■dd 4S t>l*s tax

INDY AMATEUR SUPPLY

P.O. Box 421
Indianapolis, IN 46206

i^6

Lsn

RED HOT SPECf A

Azden PCS3000 two-metef

S2SS

Santec HT 1 2Q0 2 m handheld

S279

KDK 2025. MKII, wfTT mrke

$269

Janel QSA 5 2*m preamp

$36.50

Bearcat 20-20 Scan ner

$278

KantronJcs FOII Code Reader

$360

All MFJ items 12% off list |

Ten-Tec Argosy Xcvr

$469

Ten^Tec Delta Xcvr

S738

Ter^*Tec Omni Xcvr

SI 040

A2den PCS'300 2-m handheld

$280

2 only Icom 2KL tin ear amps

S999

AEAMorsematic

$167

icantronics Micro HTTY sender

S25S

Sencher black paddles

$35

Ben Franklin Electronics

11572 N Main Hillstxsro KS 67063

316-947-2269

1^439 1

C.B. SPECIAL

(Repeat Of a sail out)

CONVERT THESE TO
10 METER Fil

Hm* Hy-Gam 40 criinn») pnnltd Ctrcuit
boards ass«rnt)iy (^^ticrv po! vOlumi
COf^trot artd Ch«r>r>el swflch HHpr incJudedl
Boards told as is Ojmensjon S 'X6'

1-0 pet $7.50 •!,

10-49 pet $6.50 ei.

fWhM«guanMttai la»1)

REMOTE 40 CHANNEL C.8.

Hemoles tiave a matat !ram« Speahef,
piaaric case, ai^d control m^c nor inciudtKl.
Sold as IS $14.95 •«

C.B BARGAIN

G.6. boards rrnssmg parts Or damaged,
Can h^ used tot st^are parts Buv 9evera^' >

Order mlormal^on Please add 14,00 for
S/H via UF5 COD s accented tor orders
Toiahnfl S&OOO or rrora l^londs residents
add 4°/d sales l»* Minimi^m order $15 00
Foreign Orders US funds oriiy add ;Q% for
S/H MASTER CARD ftnd VISA accoc>t*d

Surplus Ei«ctronlG$ Corp*

7294 NW 54th St.

MtamJFL 33166 *^*^

P H J 305 887^228

TRS-80® DISCOUNT

*^313

1 ^800-84 1 -0860 i^it nwi

MICRO MANAGiMINT
SYSTEMS »NC.

DEPT. NO, 1 3

DowniQwri FIqzc Slioppmg Canttf

115C Second Awe S.W,

Colro, Georgio 31736

913'377-7120 Go. Phono No,

Write For Free Catalog

RF MODULATORS

Small SJi«
1^ X 3 1 1'.^

Only

49,95

» CRYSTAL CONTHOLLEO FOR STABJI.ITV

• IC CtRCUITRV FOR EXCELLENT RELIABILfTY

• EXTERNALLY SWITCHED FOR CHANNELS Icr 4

The VM-1000 Rf Modufator is the same type and
qu&lrty of Ihoae found in todays video tape lecordefs. II
h as con ^e n ient ph o no j a c k 3 f o r v ideo and a udio 1 npu ts a nd
has a sisndard "F" lyp^ conn&ttor for RF oulput. Power o
SLippliE?d by an AC to DC power pacK wnich js included
Call NOW forrmore inrormatlon and torquantity diacounts,

JJT DISTRIBUTING ^25

17210 Yukon Ave., Suite #1

Torrance, Calif. 90504

Call COD Orders lo; (213} 515-6800

this publication
is Qvoiloble in

mKlOiOiin

j_ * *< « '

University Microfilms Internsttonal

300 North Zeeb Road

Oept. P.R.

Ann Affcor, Ml 48106

U.S.A.

l&BadfordRow
Dtpt PR.

London. WC1R4EJ
England

16-Pole Equalizing

RF Processor

hr«w SrwTHixid £E'2 mllt^itne ipMeh fnoamor for «nv iranr
mitiBr or transceiver. An ouu^iMiifi nf tlv SJunmocxl no-
con^raT^ RHIF jKOcenoo- ContMm bti^li-tri SE-1 mJki
fiwiMiSKV-mpanK «|u«li»r for maximum Inuliigibilitir,
Emv TO insttfl. No iiBiiwiiei modfficvtknf nqMlrKl Tws
speciallv dsa^ned ftfnta crfOMi riiten. plu» tunl. ■«>«« IC
dipping msotB exc^lvnT taih,|»wvf end linghi tjii i,ii.i^lnii iffl-
d«v. VVidfr ^ynaniic-nngi IC balancaiJmodulitorfndpraduet
detecior. Aim£o inpni/cquaSzar cirajitrY wof^ wttii both
-.- and kiw- imprtwcf mtempNinw wntiout ovtrkw) or
ntswrtian, AdiusTibte dipping 1} to 30 dO or mCMf*. Ec|uMiluiition
G » 20 dB. VfeTsstility^ quatrtv. pg for nunc*: for ttw mniur
iifho ctemands th? b««^ Model SE 2: I4O0.0O.
Aifai 53 iMppiriQ pv onto^: $ 1 S cpverteas #ir
CLPnipevisr PlHKoontacilngomipuc, PeBifadk24 49,!>4070,
Ifl^otosdt, West Germvnv.

5h6*wood &igfn€€ring Inc

MS8 South Ogden St.

Denver, Colo. 80210

(303) 722-2257

-™ rt *yift Au torn* lie
TR-2400 Kind Scinmr

iat Kenwood TR 2400 ^tops and locks on busy, ur slops^
and resumes i*hen c^rrter drops. ConlroKed by Itey
board, no swilche;. td> add. Irtstalls easily tnsrde rig. six
SuTipEfl coinnflcTioriiS> no modifrca^lJons. Does nol UiS#
ipsct provided for PL
Afls«mbeed— $24 9S Kit— £14.g&

TR*9000 PiMfiOfV Sc«nn«f

lor Kenwooo Tft.gOGO scans 5 memory channets Slops
on busy and resun^es when cafri<er drops U^es «mi sling
controls, NO 3wii£:r>es la add. InstaHs easily tn«id« rig
StC product nflviiBiw S«f>t. issue 73 Magaiinm.
AssflmblAd— S39^

tC-280 i*r>d Se«nrMr^S2i.95

Utinorv Sc«nn*f— (3ft.l£ botTi for K9M

* S^annefs do nol aftsct ftofmai rig opetration

* PiQ'laF readouts di9|iC9v scanned FreqtMtncy

' Alt scannefs are easy tD install using complete ^nd de
tailad inslallation instructions

* AH scanners ASSEMRLED £ TESTED (emeepl kin

* Sa lis tad ion Guaranteed'

Send crhftcki ot money of der to:

^SC^VN

261 ST W Maiy Ann Rd^ Anlkx:ti. IL 60002

ir>clude It j50 postage £ nafxllirtg
iljmois res incluid^ 5''^^Ji state tav

^.^a?

^See List of AdvefUs^rs on p»ge^ J i*

73 Magazine • February J 902 155

Decodes RTTY signals directly from youf re-
ceiver's loudspeaker. » Ideal tor SWLs, novices &
seasoned amateurs. * Completely solid state arid
self-contained. Compact size fits almost anywhere.
No CRT or demoduiator required . . . Nothing
extra to buy! # Burtt-ln active mark & space
filters with tuning LEDs for 170, 425 & 850 H^
FSK. * Copies 60, 67, 75, & 100 WPM Baudot &
100 WPM ASCIL * NOW you can tune in RTTV
signals from amateurs, news sources & weather
bulletins. The RTTY READER converts RTTY
signals Into alphanumeric symbols on an eight-character moving LED readout. Wrjte
for details or order factory direct.

RTTY READER KIT, model RRK , , , S/^.fl^ S149.9S

RTTY READER Wired and tested, model RRF . . , , , . , . %if^.p^ $219,95

Send check or money order. Use your VISA or MasterCard. Add $5,00 shipping and
handling for continental U.S. Wisconsin residents add 4% Wisconsin State Sales Tax.

'-'SO

Corporation Telephone: (414) 241 8144

Post OHice Box 51 3G, Thiensville, Wisconsin 53092

^Hiffwcta^

WACOM

UJS.ra1flnt Plo,4jEI8aB€1

CEHIHAI NEW YORK'S MOST COMPLETE HAM DEALER

(t&HWOOD TEiSaiDS

BQBOT BOO

DflAKE Tfl7DR7

VAESU FT707

Featuring Kenwood, Yaesu, Icom, Drake, Ten-Tec. Swan, Dentron, Alpha, Robots
MFJ, Tempo, Astron, KLM, Hy Grain, Mosley, Larsen, Cushcraft, Hustler, Mini
Products, Bird, Mirage. Vibroplex, Bencher, Info- Tech, Universal Towers,
Callbook, ARRL, Astatic. Shure, Collins, A6A. We service everything wesefH

Write or cat! for quote. You Woa't Be Disappointed.
We are just a few minutes off the N YS Thruway (i-90) Exit 32

ItlHW C^l^l

OUT OF STATE

ORDER TOLL FREE

800 448-9338

ONEIOA COUNTY AIRPORT TERMINAL BUILDING
ORISKANY NEW YORK 13424

N Y Rfts CalJ (3l5f ?36 Olti^

,^397

Warren- K2IXN

6ot>^WA2MSH

AI~WA2MSI

OUR NEW BANDPASS-
REJECT DUPLEXERS WITH EXCLUSIVE

BpBrCmCUIT FILTERS®

. . . provides superior performance,
especiatlv at dose f requencv spacing.

Models avaiiatJle for alt cammerctal and nam bands.
Special prices for amateur repeamr clubs.

K-79

fHaiHiBBapi

:Trr;r;Tn'zrriTTi^i

■■Y^ilAi-M^^Siii-i

P.O. BOX 7127 • WACO. TEXAS 76710
817/848-4435

BILLEf ELICTB«MCS

r.O.IOM4l)124aE BARUND. TX 75040 214/278^3553

^^^2

i 7 Watt Audio Amp Kit $6.95

5 SMALL, SIN<;LE HVBniD IC AND COMPONENTS FIT ON A r

5 K 3 1*0 BO AII^D (INCLUBEP) flUNS OM IS^VDC. GREAT FOR

Si ANV PI^OJECT THAT MEEDS AN INEXPENSIVE AMP. LE&S

f THAN 3% THD & 5 WATTS COMPATIBLE WITH S€ 01

Dooinsilay Alarm Kit $^<9$

If you hqve trcujhlp ai-eepsng iancl you wothLd l^ke ihe rest of
l:^e neighborhood To share yoi-'f misery ihcn Hns lima kil
will Defor you' There is no way toaccuralelydescFitelhe
un&arlhly howl.s. *creatn.«5 and 1 fines thai r.omfl out of ITiis
kEl fcnit separate Enne ofiCiHalorfi nre mixed, cancelled
and stei5pfirtai ay^rymg rale. lOW&ltsolcraiy^otinds A
great (on kii or a practicfil burglar afann Corn plolle with
PC board and all necessary components less speaker For
6-T? VDC ORDER DA-Q2

H^'

3T3t Time Zone Clock Kir

Mi'croprocfissor/ROM ClocX kit kpfrps lo-caltim'e <I2 hour
iifji^matl. artcl 2 wOrl<i lime iOneS (24 hour torrrnat): Large
.6" ORANGE readouts 10 ftiin ID limer for HAMS. Comes
complete with altratliveisJ^slrctaseandwallpliEgXFMR,

J Overvoltage Protection Kit $6.9S

■ H DksiI ihin mm ti^..[

• F#|1hArlQuc:h IrnrtI p^ni^l

• QygrtjfSTj^L TimelMse
' Qua!l1v collier irififitkfd ^n^

F^oieci YO\jt ^tpvnttvB i?quipmepl Irom -overvoiiagB
COiifTitions Ewery compuUsK should hsye Ome' WDrfti wlfh any
luied DC |3i.Dwvr «Outc» frcmi 10 m 2^1 vollfc up ro 2& HmiH

Seund Effects Kit

th« SE-01 SQurvd Ellicli K1tt ha& all ycm
iKHMl to h II lid a pn>aiamrn3tnn! sound effBcts
mactiineexcepl a bfaSterv -arvd s-pesker On\y
Ih* Sf-Ot provides you w»!h adPltionaf
cif-cuitry Inal frtnliKjfcj n PuIh Geniritof.
■VKjIt <S)df1«ldr tnd Comparalar !0 n)i)ki>
mere complex a&untJs ^ srsap lnclLjd«a
Tlf^iTT tw/sipec&J aaaembly tftsTrutrtiortS
and progrjimmiris^KJinhptES Y-ou can aasHy
Cri&ate G-UniKQlt, E]iploB.^cni, Sitam TraJnt,
Wind ft SuFt ana rnuch fn0f6.
Complete Kll $1B^D

W-1h dualilv PC Bosrrt fLesstjUliJery * EpHr 1
JMTT Chip It PncludHJ
EHira chtpi 13.19 H.

ElECTRONIC i^USlC MAKER

THIS Uf^iaUE KIT COMTAIIsrS A
MICflOPfiOCESSO!^ Ct*tf WITH ffOM,
IT HAS BEEN PftOORAMMED TO PLAY
THE FIRST * ro 10 HOTES OF THE
TUIWES LISTED BELOW. CONSTitUC-
TfONtS SmPLE, WORKS W^TH ANY 9
OR 1A Ot^U ^PKn.lftOT IfiCtUDFDi.

TflE K3T WILL OPEflATE Of*

tSVfiC OH 12VAC WITH OPTIONAL

TflANSFOttMMIJ, (CONVERTS TO

117 V A O.Alt COtlPOHMttrS 3 BOAfiO

CempltltKil $16.95 TfanifarmerSl.lS

TuH^ TnrcudDT ' WllllMit TiHI ■ H^I«t|i^NChonjf ''

^l-fi $p»ni^t:4 Bnnncr ' YinhM EJo^tdl* "- Amatin

*m*MiT» • D^irihvhljnn) It^a - W#[3[S(nfl Hjiri:*! ■

OmUhimwi & iltijvi^ Jlh 't^tll »flrlli " L* ^i*n t r, fl oa* '

Sr<r Wnv Themr ' C^cm^ntln^ '' Augi.itlinc' ' jm^iv

0*411 ' -Grnd Si«c tht QuMn -^ Cf,if,f,ri Btj^^^f '

M HriPillpK^F ' O ^ole Mi« ' ^»m& L ikI* ' T IH £ nil ' Blu*

iJanubr " Bratrnit |.itllJihr ' Wrt*iwTin™t*r thirfiB "

Simpiv ChlmE ' C!i«f:intll[M| QnhjtPK ni-imE

Start the newyeeir rigftt , . the satfing w&yf

OtA.

CA3O90 TRA^JS COND AMF

TLO-SZ DUAL BI-FET AMP

C D J Sfifi C MOS S^O 'SO CM Tfl

MC3301 QUAD OP AMP IH?>E »l

FPT500 PHOTO TRANSISTOR

TIP \m HPH DARL £A IC

TEMP CONTROLLED HOTPLATE V

.A6

.44
.44

rf 1ft

DUAL PHOTO RESISTOR 3/S
T' BOHM SPKR, ?5 W
AV 3-S9-fO SOUND EFFECTS
fin PAGE MANUAL FOR ABOVE
JUMBO RED LED ASST STYtES

Ti.as

2D>1.BH

Regulator Card
Kit $14.9S

Tnii Hi ihB PegH^'ijiicir Cird frflm ouj Famoys.
2EIA pQwtr Supply KIL Although we ran oul of
1l»e tfansiLKmera anJ healslnka, rnany

£Ll:tilpni-n a hn^t; hc;f!n ^hl^1c.7<iiic:ji4¥'hl'»<ir (iw^

vcilliQi r^ulaticn end *iSi 4diiis14tol* foSd
tdck curreni inriiciTig: Output voHjigeli ilibdii
lo SOOHV irtjm D lo U Ampi ind idjuililidt
tiwm 11 Id %^ yollB.. "Designed 1o driMe2 high
c\*iTEin J N FN .trans lalor-s \2^unx zwasoi or
equlv.^ Tn^unfl asaammes quIchJy Indudf^d
are alH tha en bn^rd com^rn^ts lAi^lvd^i^^^ ?i
di'iv^^ hr9Fi$i.K!&l dn^ O-vcir-E^imp $h<Jl:d^wn

^uni&cw De!jign0i7tri&cTP*do*TiioaBtaflda-rd
3"' diamale^ t^mpuler grade Inier tap. the
quaJlly fjlated PC card la 3-1/?" « ^^*' .

IHITM INS^TR.'C.IIOMS^

niOUiATOn CARO KIT %M,M

HIQKCURRSNT PARTS

(2 ' ihlllrf 2 a JSA arW4*| fS.QO

3 1 .OM HFD OfiO 4DV Camputtr (if Ml* S3. SO

Roqulrt* TrMKarnnr with 14 - 1tUJC Oyl # Thi

THE SUPEfl MUSIC MAKER KIT

REVtSiaN2-SZ4.95

Nrw vOM Ciu) pl^v l!iir<liE-[fH ul smgs'Rina the
BuHill Supur Wuilt' MaN Bt Tt* e •:! 1 it liHurM t iIuqIei
ftcflqrv p«rai}4-atnmHd rnln-DprDCBiNr IC tha; CCtllfS
wi th 2!:- |:.i £ • |M .-iiir.:i niiiiivLl ¥■ I a ■ UuhES E V at^itinq
l?re add 111 D i^H I PRflM S I ??(ifl"s I We ^ys lem uan bi:
fi^prtrHHd l[?pl(ivi up 10 ll)0&i»lBS[rtrPRaPi( TSu;
w-l i:<i iritis wilh ill ElfElrwilc utniwiinlt |1kSI Iht
PflQMI. and a [Jr'IfRd. plaietf and LciERnE4l PC
fionrci which mflasuffii ^" s J-.V t^k 7 i^tll
intf IJMir ^ECEidr en on ^he Si^me fC board and
dnvE'i an & ohrn SiPCiikur rnal incluilRdI Smcf
Ihfl ijnil vtorK*. m 12 VUC or I? PC ■.■i^hitie di
por 1^1 tk 11 i!?r HM>n It- pQ'^'iihte Whll ild VBu pi fflr
k24.S&T fMHrythlna IVUl I stwakar. Er3nE.lDfmEr.t1.tt
SWilchK. ami Pinil. Ai1ditiJi.;i;il :!?0e PflOMS
allMj'n con! aim Rg, otipular imwiS ^■i&ivilahln In?
iS.ffi Riich Lists fi! JvijilalilE' PROM aUKifps 3r»
AVitilabIc mn rAq^iiCAl

HIP SurlEctiBS l>ri; g pn-s [}w! ^ rxD.!i ?.a)/Sat
fC^n =lie dJFEnlly $af{lir«j td PC Bri Id acnejs

tllHR?.!

Ullry SwitttiBt ywg ^jKi^MiOn ?.$''Sb|

iFn-r reflinll Wklofl l-Q PC Bd to kc^^s liinftsi
htUBClJMf Tjh Plastic CilB ft.M

WHHpJiig TraPBlflrfflir J.DIT

iFi:i optiatmn OJi n?VAC h&use VDHlaaEl

ORDERING tN FOR MAT ION:
C9U or Wffta far Frae^ Cutshg

TEMP ERE D G L A SS 11 0"F to 1 60'f 1 ■ BB
3550 < Fa f M ICRO P CH I P Z JQ

lOtCia SENSITI\/E GATE SCH 3^*B

i
i

f
f

SUPER SPECIAL DEALI
STANDARD C, 60 CASSETTE NEW
IN PLASTIC CASES rOP QUALITY
DRIG. USED m-' PJGtTAL' APP
PREO RE-r-.POf*S.E :iOOH2 - IfiKHZ
1.3^5*^. 3/3.50

CO-D MINl*fllJM $JO.OD A ADD SJ.SO FOR COD'S

- UPS DELivtnv ApORES^ MUST ACCOMPAr^r ALL coo F

ORDERS

jl.DD HANDLING QN OROFHS UNDER Sld.H)

VI$A. MC CAflDS- Ofl CHECK

ADti ^■•■^ FOR SH1PP1HC

TEKA^ «E&IOf NTS ADD S^a STATE SA|,|&^ 1 An

ALL f OqErGN ORDERS ADD 2W-- FOIl SHIPPING

(CANADA n=..| No FOREIGN COD &

CALL (214) 37fl-3iSS5 TO Pi Att CRtDIT CARD Qfl COO

ORDER

■I

futwi tfm^

GOTHAM
ANTENNAS

(81 3) 584-8489

SMALL LOT TRAP DIPOLES

MODEL
TSL 6040
TSL 4020

BANDS

80,40

40.20.15

LGTH

78'

40"

SMALL LOT SHOf^TENED DI POLES

SL8010

eO,-30.20.
15,10

75'

S59,95

SL reo

1^0

130'

S36,95

SLSO

63-

S35.S^5

SL'40

40,15

33-

$34.95

FULL SIZE PARALLEL OIPOLES

FPD8D10

80.40.20.
15.10

130'

S499&

FPD4010

40.20,15.10

S449S

^»EW! POflTABLE VERTICALl IDEAL FOR

APAHTMENTS> CAMPING. TRAllERSJ

Folds to &' PacVage No RadtaJs, R^qutred
Fufly Assembled. Full Legal Lirrtil. 11 VSWR

MODEL BANDS HGHT PRICE

PVeOlO 8010 13" $5995

PROVEN DESIGN ■ QOTHAM ALL SAND
VERTICALS

V160

V-flO

V40

i6o,ao.40.?d,

33'

53^.95

fS.10.6

80,40,20

$3795

15.10,6

40.20,15.10.6

£3S.§S

FAM0U5G0THAM QUADS
^ 2 Elem^nis — 3 Bands Complele £1 19.95

CHAMPIONSHIP GOTHAM BEAMS
Fyll Size Complete trom t79.95

CALL OR SEND LARGE SASE FOR CATA-
LOG Shipping: Dipok«£ & Verl^cals
52.50 USA;S7.00 Ca nada: S5 00 FPO. APO
Beams & Quads Shipped UPS or Freight
Collect. FIs. add 4% Sales Tux

P.O. Box 776 • Largo, FL 33540

1^417

PRICE
$49.95

S4/.S5

150 TSMagazin^ • February, 1982

Scanners!

NEW Rebates!

Communications Electronics™ the

world's largest distributor of radio scan-
ners, celebrates 1 982 with big savings on
Bearcat scanners- Electra Company, the
manufacturers of Bearcat scanners is
offering consumer rebates on their great
line of scanners, when purchased be-
tween February 1 and March 16, 1982.

With your scanner, you can monitor the
exciting two-way radio conversations of
police and fire departments. Intelligence
agencies, mobile telephones, energy/oil
exploration crews, and more. Some scan-
ners can even monitor aircraft transmis-
sions! You can actually hearthe news i)efo/'©
if s news. If you do not own e scanner for
yourself, now's the time to buy your new
scanner from Communications Electron-
ics. Choose the scanner thafs right for you,
then call our tolHree number to place your
order with your Visa or Master Card

We give you excellent service because CE
distributes more scanners worldwide than
anyone else. Our warehouse facilities are
equipped to process thousands of scanner
orders every week. We also export scanners
to over 300 countries and military instal-
lations. Almost all items are in stock for
quicl( shipment so if you're a person who
prefers fact to fantasy and who needs to
know what's really happening around you,
order your scanner today from CEl

NEW! Bearcat^350

The Wf immte SynfhmsixBd Scanner!

List price $599 95/CE price$399.C»0/£50,00 rftbate
Your final cost is & low $349-00
7-Bandf 50 Chmnnei • Alpha-Numoric • If o*
gtybM sesttner m AM Aircraft mntt Pubiic
Servicm bands* • Frioriif Channel • AC/ DC
Bands: 30-50, 11 8-136 AM. 144-174,421-512 MHz.
The new Bearcat 350 introduces an incredible
breakthrough in synthes^^ed scanning: Alpha-
Numeric Display. Push a button— and the Vacuum
Fluorescent Display switches from "numeric" to
word descriptions of whaf s being monitored 50
Channels in 5 banks. Plus, AutoS Manual Search,
Search Direction, Linttt & Count. Direct Channel
Access Selective Scan Delay Dual Scan Speeds.
Automatic Lockout. Automatic Squelch, Non- Volatile
Memory. Order your Bearcat 350 today!

Bearcat® 300

Li5t price $549. 95/CE price S349.OO/$SO.0O rebate
Your final cost is a tow $2d9,00
7-Bandf 50 Channel « Service SeBreh * Me-
Gfystaf scanner * AM Aircraft end Puhlic
Service tends* • Priority Channel • AC/ DC
Bands: 32-50, 11S-136AM, 144-174,421-512 MHz,
The Bearcat 300 is the most advanced automatic
scanning radio that has ever been ottered to the
public. The Bearcat 300 uses a bright green fluo-
rescent digital display, sc it's ideal for mobile
applications. The Bearcat 300 now has these added
features: Service Search, Display Intensity Control,
Hold Search and Resume Search Keys, Separate
Band keys to permit lock-m/lock-out of any band for
more efficient service search.

I4EW! Bearcat® 350

FREE Bearcat® Rebate Offer

Get a CQupan good for a £50 rebate when you purctiase a
Bearcat 350 or 300" $25 rebate on model 250 or 20/20; $1 5
rebate on modet 210XL $10 rebate on model 160 or 4-6
Thin Scan. To get your rebate, mait rebate coupon with your
Original dat^d sales receipt and the Bearca: model number
from the carton ro Electra, Voull receive your retiate In foLir
to six sAi'eeks. Offer valid only on purchaser made betwen
February 1, 1 962 and March 1 5, 1 932 All requests must be
postmarked by March 31, 1&S2 Umtt of one rebare per
household. Coupon must accompany all rebate reqwesfa
and may not be reproduced. Offer good only in the U.S.A.
Void where taxed or prohibited by law. Resellers, companies,
clubs and organizations-both profit and non-prottt-are not
eligible for rebates. Employees of Electra Company, I heir
advertismg agencies, distributors and retaiiers of SearcaP
Scanners are also not eligible for rebates. Please be sure to
send in the correct amount for your scanner. P^y the listed
CE pri,ce in this ad. Do r^ot deduct the rebate amoimt since
your rebate will be sent direcUy to you (rom EJe-ctra. Orders
recei^ved with insufficient payments will not be processed
an d wri I b e ret u rn ad. Otte r sul^ ject t o c hang e w J t ho ut not ice.

Bearcat® 250

List price $429.95/CE price «279-OO/$25.O0 rebate
Your final cost is a low $254.00
S-Bandf 50 Channel m Crysiailess e Searches
Stores « Recoils • Digiiat dock • AC/ DC
Priority Channel • 3-Band * Count FmatureM
Frequency range 32-50, 146-174, 420'612 MHz,
The Se^rcaf 250 performs any scanning function you
could possibly want. WWh push button ease you can
program up to 50 ctiannels for auto nna tic monitoring.
Push another button and search for new frequencies
There are no crystals to limit what you want to hear A
special search feature ot the Searca? 250 actually
stores 64 frequencies and recalls them, oneat atilne^at
your convenience.

MEW.' Bearcat® 20/20

List price S449. 95/CE price S2eQ.0O/$25.O0 rebate
Your final dOSt is a low $264.00
7-Band, 40 Chennel • Crymtailmsm • Search e^
AM Aircraft and Pubiic Service bands * AC/DC
Pricriiy Channel • i>ir»ctOhann&l Access • DelsY
Fr^QuertCYCsnge 32-50. 1i8-T36AM. 144-174. 420-5^2 MHi.

The Bearcat 20/20 automatic scanrfing radio
replaces the Bearcat 220 and monitors 40 Jrequen-
cies from 7 bands, including aircraft. A two-position
switch, located on the front parrel allows monitohng
of 20 channels at a time.

Bearcat® 21 OXL

List price S349 95/CE price S229.00/$l 5.0O rebate

Your final cost la a low §21 4. GO

S'Banvtf iO Channel • Crysfalless • AC/ DC

Frequency range: 3250, 144 174, 421-512 MHz,
The Searca/ 21 OXL scanning radio is the second gener-
ation scanner that replaces the popular Bearcat 210
and 211. It has alrnost twice the scanning capacity of
the Sear(?af 210 With 18 channels plus dual scanning
speeds and a bright green fluorescent display. Auto
matic search finds new frequencies. Features scan
delay, single antenna, patented track tuning and more!

Bearcat® 1 60

List price $a99.95/CE price S194.0O/S10.0O rebate
Youf final cost is a low Si S4.0O
5'Band, 19 Channel • AC only * Pricritw
Dual Scan Speeds • Direct Chennoi Access

Frequency range: 32-50, f 44 174. 440-512 MHi.
The Bearca f 1 60 is the least expensive 0eafcaf crystai-
less scanner Smooth keyboard. No buttons to punch
No knobs to turn. Instead, finger-tip pads provide
control ot ait scanning operations.

NEW? Bearcat® 100

riM first no-crYstmiprosremmat>l0 h^ndh^fd scanner.

At tow 30-120 d^ys for detivery after receipt of
order due to the high demand for this product.
List price $449.96/CE price $299. OO
B*Band, f 0 Channal s Litiuid Crysial Display
Search * Untit • Moid • Lockout • AC/DC
Frequency range: 30-50, 138-174, 4Q8-51 2 MH^
The world's first no-crystal handheld scanner has
compressed into a 3^' x 7" x 1 VV case more scanning
power than is found in many base or mobile scanners.
The Searcaf 1 00 has a tuli 1 6 channels with frequency
coverage that includes alf public service bands (Low.
High, UHF and ' r bands), the 2-Meter and 70 cm.
Amateur bands, pfus MiHtary and Federal Government
frequencies. It has chrome-plated keys for functions
that are user controlled, such as lockout manual and
automatic scan. Even search is provided, both manual
and automatic. Wow,,, what a scanner!

Th e Bearcat ^ 00 produ ces a udi c po we r out pu t of 300
milliwatts, is track-tuned and has selectivity of better
than 50 dB down and sensitivity of 0.6 microvolts on
VHFand 1.0 microvolts on UHF, Power consumption is
kept esttremety low by using a liquid crystaJ display and
exclusive low power integrated circuits,

I nc t u d ed i n ou r low C E pr ice i s a St urdy ca rry i n g case^
earphone, battery charger/AC adapter, six AA ni-cad
batteries and flexible antenna. For earliest delivery
from CEt reserve your Bearcat 100 today.

TEST ANY SCANNER

Test any scanner purchased ifom Communicattons
Electronics' tor 31 days before you decide to keep it K tor
any reason you are not completely salisfiet^, return it in
original condition with all parts in 31 days., for a prompt
refund (less shipping/handling ctiarges and rebate credits).

Bearcat® Four-Six ThinScan'"

List price $189 95/CE prfce $1 24.0O/S1O.00 rebate
Your ftnal cost is a low $1 1 4. 00
Frequency range: 33-47, 152)64, 450-503 MHz.
The incredible. Bearcat Four-Six Thin Scan" is like
having an information center in your pocket. This four
band. 6 channel crystal con trolled scanner has patented
Track Tuning on UHF Scan Delay and Channel Lockout.
Measures 2^ X 6 V* « V I ncludesfuhher ducky antenna.
Order crystal certificate tor each channel. Made in Japan.

Fanon Slimline 6-HLIJ

List price $169 9S/CE price $109.00
tow cost S-channelt 3- band scannerf

The Fanof^ Slimline S-HLU gives you six channels of
crystal Controlled excitement. Unique Automatic Peak
Tu n ing C i rcui t adj usts t h e rec e i ve r front e nd I or max i^tn u m
sensitivity across the entire UHF band. Individual chan-
f>el I oci<out switches. Frequency range 30"50r 146-1 75
and 450-51? MHt Si^e 2^A xS^/* x 1' Includes rubber
ducky anlen na. If you don't need the UHF band, get the
Fanon model 6-HL forSSg.OO each, and save money.
Same high performanceandfeaJures as themodel HLU
without the UHF band. Order crystal certificates for
each channel. Made in Japan,

OTHER SCAHHERS £ ACCESSORmS

HEWl Regency' t 0810 Scanner $319,00

mew? Rgency' D300 Scanner $219.00

JiEW/ Regency' DItMD Scanner $169.00

«eWf Regency' H604 Scan rier $129 00

Regency" M400 Scanner $259 00

Regency' Ml OO Scanner $199 OO

Regency ^ R1 040 Scanner , , $149,00

SC M A'6 Fa no n Mo bi le Acta pter/ Battery Qh^ rger ... $49 00

CHB-6 Faron AC Adapief/Batlery Charger $1 S.0O

CAT-6. Fanon carrying case wjth b(?lt cNp . , $15.00

AUC-3Fancinayto1ighleradapter/BaitervCharger $15 OO
PSK-6 Base Power Supply/ Bracket for SCMA'6 . . $;J0 00

SPSO &QsrC0t AC Actapter S9 00

SP51 Bedrest Sartery Charger . $9 00

SPSS B&arcat 4-6 ThinScan" carrying case Sf 2 00

MA&Q6 fl^gertgyf carrying case foe H604 . . . $t S 00

FB-E Frequency Directory for Eastern USA St 2.00

FB'W FrequfSncy Directory lor Western Lf, SA $1 2.00

FFD Federai Freqiienc/ Dhrectory for LI.S.A. . $12 00

TSG TopSeerer Regrstryof US, Government Freq. . .510.00
ASD Frequency Directory for Aircraft Bartd . . . . $10.00

B-4 1 .2 V AAA Ni Cad batteries [Set of four) $9 00

A-1 3&CC Crystal cerliticate - $3.O0

Add $3 .00 shipping for aM accessories ordered alt he same time.

INCREASED PERFORMAHCE AMTEMNAS

If you want the utmost in pertorrr^ance from your
scanner, i^t isessentiallt^atyouuseanexternalantenna.
We have six ba^e and fTl!obi^e antennas speci'fically
designed tor receiving all bands Or^der #A60 is a
magnet mount mobile antenna Order #A61 is a gutter
clip mobiie antenna Order #Ae2 is a trunk-lip mobile
antenna. Order #A63 is a ^* inch hoie mount Order
#A64 is a % inch snap-in mount, and # A70 isan ail band
base station antenna. All antennas are $35.00 and
$3 00 for UPS shipping in the continental United Slates.

BUY WITH CONFIDENCE

Togo! the test est detivery from CE ot any scanner, i^end
or phone your order directly to our Scanner Disintaution
Cenrer' Be sure !o calculate your pnce usmg the CE prices
in this ad. Michigan residents ptease add 4% sales tax.
Written purchase orders are accepted from approved gov-
ernment agencies and most weli rated firms at a HO*
surcharge for net 10 billing. AH sales are subiect toavaila-
brjity. acceptance and verffication. All sal^aon accessories
are fma! Prices, terms and specifications are subiect io
change wilhoal notice. Out ot stock items w^ll be placed on
backorder aulomatfcalty unless CE is instructed diff^renlly.
Most products Jhat we self have g manufacturers warranty,
Free copies Of is/arranties on these products are avaiiable
prior to purchase bv writing to CE. lnternati;onal orders are
invited with, a $20 00 surcharge tor special handHr^g in
addition to shipptiig chfsrges. A^f shrpmenis are RO B. Ann
Arbor Michigan No COIN'S please Non-certi^fiedandforei^gn
checks require ban-k clearance. Winirr^urn order S35.O0

Mail orders to: Communications Electronicsr
Box 1002, Ann Arbor, Michigan 48106 USA. Add
$7.00 per scanner or phone product for U.P.S.
ground shipping and handfing, or $ 1 4.00 for faster
U.P.S. air shipping lo some locations. If you have a
Visa or Master Card, you may call anytime and
place a credit card order. Order toll free in the
U.S-A. Dial 800-521-4414. If you are outside the
U.S. or in Michigan, diat 313-994-4444. Dealer
inquiries invited. Orber without obligation todayl

Scanner Distrfbution Center' and CE logos are trade-
marks of Communications Electronics*
f Bearcat is a federalty registered trademark of Electra
Company, a Division ot Masco Corporation of Indiana,
trtegencj^ is a federally registered trademark of Reg^ency
Efectrontcs Inc AD # i 1 2 1 0S 1

^377

COMMUNICATIONS
ELECTRONICS"

a54 phoflnii n BoJi ^007 D Ann ArtKvr. WHthigan 4fl106 U S A.
Cal I TOLL^ F n E E {AOO] 52 1 44 1 4 or wi*i4* U . S. A ( 1> S| 904^4444

^"■^ electromc;^

Introducing

(602) 242-3037
(602)242-8916

2111 W. CAMELBACK ROAD
PHOENIX, ARIZONA 85015

TVRO CIRCUIT BOARDS

Satellite Receiver Boards— Now in Stock

DUAL CONVERSION BOARD .$25.00

This board provides conversion from the 3,7-4.2 band first to
900 MHz where gain and bandpass filtering are provided and,
second, to 70 Mliz. The board contains both local osciilators,
one fixed and the other variable, and the second mixer. Con-
struction is greatly simplified by the use of Hybrid IG amplifiers
for the gain stages.

SIX 47pF CHIP CAPACITORS

For use with dual conversion board ..-...,, ,$6.00

70 MHz IF BOARD $25,00

This circuit provides about 43d8 gain with 50 ohm tnput and
output impedance. It is designed to drive the HOWARD/
COLEMAN TVRO Demodulator. The on-tKDard bandpass filter
can be tuned for bandwidths between 20 and 35 MHz with a
passband ripple of less than Vt dB, Hybrid IC's are used for
the gain stages.

SEVEN .01 pF CHIP CAPACITORS

Foruse with the70 MHz IF board. , . , . .$7,00

DEMODULATOR BOARD ,$40.00

This circuit takes the 70 MHz center frequency satellite TV sig-
nals in the 10 to 200 millivolt range, detects them using a phase
locked ioop, de-emphasizes and filters the result and ampli-
fies the result to produce standard NTSC video. Other outputs
include the audio subcarrter, a DC voltage proportional to the
strength of the 70 MHz signal, and AFC voltage centered at
about 2 volts DC.

SINGLE AUDIO. .... .$15.00

This circuit recovers the audio signals from the 6.8 MHz fre-
quency. The Miller 9051 coils are tuned to pass the 6,8 MHz
subcanier and the Miller 9052 coil tunes for recovery of
the audio.

DUAL AUDIO , .$25-00

Duplicate of the single audio but also covers the 6.2 range.

DC CONTROL. $15.00

SPECIAL SET OF FIVE BOARDS $100.00

INCLUDING DUAL AUDIO (2 single audio boards)

1900 to 2500 MHz MICROWAVE DOWNCONVERTER

MICROWAVE RECEIVER This receiver is tunable over a range of 1900 to 2500 MHz approximately, and
is intended for amateur use, The local oscillator is voltage controlled, making the I.F. range approximate-
ly 54 to 88 MHz for standard TV set channels 2 thru 7.

P.O. BOARD with DATA 1to5 $15.00 6to11 $13.00 12to26 $11.00 27-up $9.00

P.O. Board with all parts for assembly $49.99 P.O. Board with all chip caps soldered on. . . $30.00

P.C. Board with all parts for assembly P.O. Board assembled & tested $69.99

plus 2N6603. $69.99 P.C. Board assembled & tested with 2N6603$79.99

HMR 11 DOWNCONVERTER with Power Supply, Antenna (Dish) & all Cables for installation. 180 Day Warranty.

1to5 $150.00 6 to 11 $140.00 12- up $125.00

YAGI DOWNCONVERTER with Power Supply. Antenna (Yagi) & all Cables for installation. 90 Day Waranty.

1to5 $150.00 6 to 11 $140.00 12 -up $125.00

YAGI DOWNCONVERTER as above but Kit. (NO CABLES) With Box.

1to5 $125.00 6to11 $115.00 12-up $100.00

HMR II DOWNCONVERTER as above but Kit. (NO GABLES) With PVC.

1to5 $125.00 6 to 11 $115.00 12- up

.00

«#^¥*»»**if*»»#*»*#«»^"

f *=**^*^

SPECIAL NEW STOCK OF CARBIDE DRILL BITS— YOUR

1.25mm
1.45mm
3.2mm
3.3mm

1/8

3/16
5/32

7/32

13/64
19
20
24

29
30

36
37
38
39
40
44
45
46

47
48
49

50
51
52

53
54

CHOICE $1.99

■**■■ urn

■

1$0 73 Magazine • February, 1982

"DOWN CONVERTERS"

1900 to 2500 MHZ Microwave Downconverters

In Regards to your request for information concerning our microwave receiver. This
receiver is tunable over a range of 1900 to 2500 MHZ approximately, and is intended
for amateur use. The local oscillator is voltage controlled (i.e.) making the I.F.
range approximately 54 to 88 MHZ For Your Standard TV Set Channels 2 thru 7.

P. C. Board with Data

1 to 5

$15.00

6 to 11

$13.00

12 to 26

$11.00

P. C. Board with all chip caps solder on.

P,C. Board with all parts for assembly.

P. C. Board with all parts for assembly plus 2N6603

P. C. Board assembled and Tested.

P. C. Board assembled and Tested with 2N6603.

HMR II Downconverter with power supply — antenna (Dish)

180 Day Warranty .

1 to 5

$150.00

6 to 11

$140.00 12 to up

$125.00

Yagi Downconverter with Power Supply , Antenna (Yagi) and all cables for
Instalation. 90 Day Warranty.

1 to 5

$150.00

6 to 11

$140.00 12

$125.00

Yagi Downconverter as above but Kit. {NO CABLES) With Box.

1 to 5

$125.00

6 to 11

$115.00 12

$100.00

HMR II Downconverter as above but Kit, {NO CABLES) With PVC.

1 to 5

$125.00

6 to 11

$115.00 12

$100.00

$9.00
$30.00
$49.99
$69.99

$69.99
$79.99

Special New Stock Of Carbide Drill Bits.

1.25rnn

1.45mm

3.2inn

3.3i[in

1/8

3/16

5/32

13/64

Your Choice $1.99

Tod Free Number
800-528-01 80

(For orders only)

Q^^^§\x elect roi|ics

*^159

See List of Adv&fUsers on page T 14

73Magazine • February, 1982 159

"FILTERS

Con ins Mechanical Filter #526-9724-010 Model F455Z32F
455KHZ at 3.2KHz Wide.

$15. 00

AtUs Crystal Filters

5.52-2.7/8

5.595-2.7/8/U

5.595-. 500/4/CW

5.595-2.7/LSB

5.595-2.7/USB

5.645-2.7/8

9.0SB/CW

5.52MHZ/2.7KH2 wide 8 pole
5.595HHZ/2.7KHZ wide 8 pole upper sideband
5. 595MHz/. 500KHZ wide 4 pole CW
5-595MHz/2.7KHz wide B pole lower sideband
5.595MHZ/2.7KHZ wide 8 pole upper sideband
5. 645MHz/ 2. 7 KHz wide 8 pole
9.0MHz/ 8 pole sideband and CW

Your Choice
$12.99

Kokusai Electric Co. Mechanical Filter #MF-455-ZL-21H

455KHZ at Center Frequency of 453. 5Kc Carrier Frequency of 455Kc 2.36Kc Bandwidth

$15.00

Crystal Filters
Nikko FX-07800C
TEW FEC-103-2
Tyco/CD 001019880

Motorola

4884863B01

PTI

535QC

PTI

5426C

A10300

Ceramic Fi

Iters

Murata

BFB455B

CFM455E

CFM455D

CFR455E

CFU455E

CFU455G

CFW455D

CFU455R

SFB455D

SFE10.7

SFG10.7MA

Clevite

TO-OIA

T0-02A

Nippon

LF-B4/CFU455I

LF-B6/CFU455H

LF-C18

Tokin

CF455A/BFU455K

Mat sushi ra

EFC-L455K

7.8MHz

10.6935

10. 7MHz 2 pole 15KHz Bw. Motorola #48D84396K01

Thru #48D84396K05

11.7MHz 2 pole 15KHz Bandwidth

12MHz 2 pole 15KHz Bandwidth

21.4MHz 2 pole 15KHz Bandwidth

45r^Hz 2 pole 15KHZ Bandwidth (For Motorola

Comnuni cations equipment)

10.00

4.00
5.00
5.00
5.00

5.00

455KHZ

455KHZ +-

5.5KHZ

455KHZ +-

7KHz

455KHZ +-

5.5KHZ

455KHZ +-

1 . 5KHz

455KHZ +-

IKHZ

455KHZ +-

IKHZ

455KHZ +-

3KH2

455KHZ

10.7MHz

455KHZ

455KHZ +-

IKHz

455KHZ +-

iKHz

455KHZ

455KH2 +-

2KKZ

455KHZ

$ 2.40
6.65
6.65
8.00
2.90
2.90
2.90
4.35
2.40
2.67
10.00
5.00
5.00
5.80
5.80
10.00
4.80
7.00

RQTRON MUFFIN FANS Model Mark 4/MU2A1

These fans are new factory boxed 115vac at 14watts 5O/60cps

CFM is 38 at 50cps and 105 at 60c ps.

Impedance Protected- F

$ 7.99

SPECTRA PHYSICS INC. Model 088 HeNe Laser Tubes.

Power output l,5niw. Beam Dia. .75niii. Beam Dir. 2.7mr. 8Kv starting voltage

68f( ohm Iwatt ballast lOOOvdc +-100vdc 3.7ma. TUBES ARE NEW $59.99

lao 73MagaTine • February, 1982

"AMPLIFIERS"

AVANTEK LOW NOISE AMPLIFIERS

Model s

Frequency Range

Noise Figure

Voltage

Gain

Power Output

Price

UTC2-102M

30 to 200MC

1.5d8

+15vdc

29dB

IdB Gain +7dBm

$49.99

/\p_20-T

200 to 4aOMC

6.5dB

+24vdc

30dB

IdB Gain +20dBm

$49.99

AL-45-0- 1

450 to 800MC

7dB

-6vdc (a +12vdc

30dB

IdB Gain -5dBm

$49.99

AK-IOOOH

500 to lOOOMC

2.5dB

+12vdc 0 -12vdc

25dB

IdB Gain +8dBm

$69.99

Mini Circuits Double Balanced Mixers

Model RAY- 3

Very High Level (+23dBm LO) 70KHz to 200MH2 LO,RF,DC to 200MHz IF

Conversion Loss,dB One Octave From Band Edge 6Typ./7.5Max. Total Range 6.5Typ./8Max.

Isolation, dB Lower Band Edge To One Decade Higher (LO-RF/LO-IF) 55Typ./45Min. Mid. Range

(LO-RF/LO-IF) 40Typ./30Min. Upper Band Edge To One Octave Lower (LO-RF/LO-IF) 30Typ./

25Min.

Price $^4.99

Model TSM-3

Standard Level (+7d8m LO) .IMHz to 400MHz LO,RF,DC to 400MHz IF

Conversion Loss.dB One Octave From Band Edge 5.3Typ./7.5Max. Total Range 6.5Typ./8.5Max.

Isolation, dB Lower Band Edge To One Decade Higher (LO-RF/LO-IF) 60Typ./50Min. Mid. Range

(LO-RF/LO-IF) 50Typ./35Min. Upper Band Edge To One Octave Lower (LO-RF/LO-IF) 35TYP./

25Min.

Price $11.99

i^^^^^"^^^

Hewlett Packard Linear Power Microwave RF Transistor HXTR5401/35831E

Collector Base Brakedown Voltage at lc=100ua
Collector Emitter Brakedown Voltage at Ic=500ua
Collector Cutoff Current at Vcb=15v
Forward Current Transfer Ratio at Vce=15v,Ic=15ma
Transducer Power Gain at Vce=18v»Ice^60ma,F=2GHz.
Maximum Available Gain at Vce^l8v,Ic^60ma,F=^lGHz/F-2GHz
Price $29.99

Motorola RF Power Amplifier Modules

35volts min*
SOvolts min,
lOOua max*
15min,40typ,125max
3dBmin,4dBtyp
14dB typ»8dB typ

Model

MHW612A

MHW613A

150 to 174MH2

MHW710

MHW72a

Frequency Range

146 to 147MHz

400 to 512MHz

400 to 470MHz

Voltage

12.5vdc

Output Power

20watts

30watts

13watts

20watts

Minimum Gain

20dB

19.4dB

21dB

Ha nnon i cs

-30dB

40dB

RF Input Power

400nfiw

500mw

250nM

250mw

Price

$57.50

$59.80

$57.50

$69.00

Toll Free Number
800-528-01 aO
(For orders only)

Q^^i\T elect roi|ics

See Lt^f of Aa^erttsers on pjtge tJ4

73Magsime • February, 1982 161

fifi

TRANSISTORS"

WATKINS JOHNSON WJ-M62 3.7 to 4.2GHz Communication Band Double Balanced Mixer

$100.00

SSB Conversion Loss 4.9dB Typ. 6dB Max. fR 3.7 to 4.2GH2

5.5dB Typ. 6.5dB Max. fl DC to 1125MH2 fL fR

fl 880MHz fL fR
fR 3.7 to 4.2GHz
4.9dB Typ. 6dB Max. fl'aO to il25MHz fL fR

SSB Noise Fiqure

Isolation

fl at R
fL at I

5.5dB Typ. 6.5dB Max. fl 880MHz fL fR

30dB Hin. 40dB Typ.

25dB Min. BOdB Typ.

20dB Min. 30dB Typ.

15dB Min. 25dB Typ.
Conversion Compression IdB Max.

fL 2,8 to 5.35GHz
fL 4.5 to 5.35GHz
fL 3.6 to 4.56Hz
fL 2.8 to 3.6GHz

fR Level +2dBm

Flatness .2dB Peak to Peak Over any 40MHz Segment of fR=3.7 to 4.2GHz

Third Order Input Intercept +ndBm fRl=4GHz fR2=4.01GHz Both at -5dBm fL=4.5GHz
Group Time Delay .5ns Typ. .75ns Max. fR3.7 to 4.2GHz fL 3480MHz @ +13dBin

VSWR

L-Port

1.25:

:1 Typ. 2.0:1

2.8 to 5.35GHz

R-Port

1.25:

:1 Typ. 2,0:1

3.7 to 4.2GHz fL fR

1.4 :

:1 Typ. 2.0:1

3.7 to 4.2GHz fL fR

I-Port

1.5 :

:1 Typ. 2.0:1

fl--

=100MHz

1.3 :

:1 Typ. 2.0:1

fl =

=500MHz

1.8 :

:1 Typ. 2.5:1

fl =

^1125MHz

SGS/ATES RF Transistors

Motorola RF Transistor

Type.

BFQ85

BFW92

HRF901 2N6603

Collector Base V

20v

25v

25v 25v

Collector Emitter

V 15v

15v

15v 15v

Emitter Base V

2.5v

3v 3v

Collector Current

40ma

25ma

30ma 30ma

Power Dissipation

ZOOwM

190mw

375mw 400niw

HFE

40mi n .

200max.

20min. 150max.

SOmin. 200max. 30min. 200max.

4GHZ min. 5GHz

max. 1.6GHz Typ.

4.5GHz typ. 2GHz min.

Noise Fiqure

iGHz 3dB Max.

500MHz 4dB Typ

IGHz 2dB Typ. 2GHz 2,9dB Typ.

Price

$1.50

$2.00 $10.00

National Semiconductor Vari

able Vo

Itage Regulator Sal

e !!!!!!!!!

LM317K

LM350K

LM7236/L

LM7805/06/08/12/15/18/24

1.2 to 37vdc

1,2 to

33vdc

2 to 37vdc

5. 6, 8.12.15,18,24vdc

1 . 5Amps

SAmps

150nia.

lAmp

TO- 3

TO-lOO/TO-116

TO-220/T0-3

$4.50

$5.75

$1.00 $1.25

$1.17 $2.00

P & B Solid State Relays Type ECT1DB72

*May Be Other Brand Equivalent

Toll Free Number

800-528-0180
(For orders only)

5VDC Turn On 120VAC Contact 7 Amps

20Amps on 10"xl0"x.062" Alum.Heatsink with
Silicon Grease $5,00

(fVI^jz electroi|ics

182 73 Magazine • February, 1 982

MIXERS"

WATKINS JOHNSON WJ-M6 Double Balanced Mixer

LO and RF 0.2 to 300MH2
Conversion Loss (SSB)

Noise Figure (SSB)

Conversion Compression

IF DC to 300MH2
6.5dB Max. 1 to 50MHz
B.5dB Max. .2 to 300MH2
same as above
8.5dB Max. 50 to 300MH2
.3dB Typ.

$21.00

WITH DATA SHEET

NEC (NIPPON ELECTRIC CO. LTD. NE57835/2SC2150 Microwave Transistor

NF Min F=2GHz
F=3GHz
F=4GHz

dB 2.4 Typ.
dS 3.4 Typ.
dB 4.3 Typ.

MAG F=2GH2

F=3GHz
F=4GHz

dB 12 Typ,

dB 9 Typ.
d8 6.5 Typ

$5.30

Ft Gain Bandwidth Product at Vce=8v, Ic^lftna. GHz 4 Min. 6 Typ.
Vcbo 25v Vceo llv Vebo 3v Ic 50ma. Pt. 250niiw

UNELCO RF Power and Linear Amplifier Capacitors

These are the famous capacitors used by all the RF Power and Linear Amplifier manufacutures
and described in the Motorola RF Data Book.

lOpf

14pf
20pf

22pf

25pf
27pf
27.5pf

30pf

32pf
33pf
34pf

40pf
43pf

62pf
SOpf

lOOpf
120pf
180pf
200pf

250pf 1 to lOpcs. .604 each

820pf 11 to 50pcs. .504 each

51 to lOOpcs, .404 each

NIPPON ELECTRIC COMPANY TUNNEL DIODES

Peak Pt. Current ma.
Valley Pt. Current ma.
Peak Pt. Voltage mv.
Projected Peak Pt. Voltage
Series Res. Ohms
Terminal Cap. pf.
Valley Pt. Voltage mv.

Ip
Iv

Vpp

Vf=Ip

MODEL 1S2199
9min. lOTyp. Umax.
1.2Typ. 1.5max.
95Typ. 120max.
480m1n. 550Typ. 630max
2.5Typ. 4max.
1.7Typ. 2max.
370Typ.

1S2200 ^^'^^
9min. lOTyp. Umax.
1.2Typ. l.Smax.
75Typ. 90max.
440m1n. 520Typ. 600max
2Typ. 3niax.
5Typ. 8max.
350Typ.

FAIRCHILD / DUMONT Oscilloscope Probes Model 4290B

Input Impedance 10 meg.. Input Capacity 6.5 to 12pf . , Division Ration (Volts/DIv Factor)

10:1, Cable Length 4Ft. , Frequency Range Over lOOMHz.

These Probes will work on all Tektronix, Hewlett Packard, and other Oscilloscopes.

PRICE $45.00

MOTOROLA RF DATA BOOK

List all Motorola RF Transistors / RF Power Amplifiers, Varactor Diodes and much much
more.

PRICE $7.50

Ton Free Number
800-528-0180

(For orders only)

^/i*^x electroi|ic$

t^See Ust of Aavernsms on fiOffe f t4

73 Magazine • February J 982 163

"SOCKETS AND CHIMNEYS"

EIMAC TUBE SOCKETS AND CHIMNEYS

SKUO

Socket

SK406

Chimney

SK416

Chimney

SK500

Socket

SK506

Chimney

SK6Q0

Socket

SK602

Socket

SK606

Chimney

SK607

Socket

SK610

Socket

SK620

Socket

SK620A

Socket

JOHNSON

TUBE SOCKETS

$ POR
35.00
22.00
330.00
47 . 00
39.50
56,00
8.80
43.00
44.00
45.00
50.50

SK626

Chimney

SK630

Socket

SK636B

Chimney

SK640

Socket

SK646

Chimney

SK711A

Socket

SK740

Socket

SK770

Socket

SK800A

Socket

SK806

Chimney

SK900

Socket

SK906

Chimney

7.70

45.00

26
27
55

192
66
66

150
30

253
44

40
50
00
50
00
00
00
80
00
00

124-115-2/SK620A Socket
124-116/SK630A Socket

$ 30.00
40.00

124-113 Bypass Cap.
122-0275-001 Socket
(For 4-250A,4-400A,3-400Z,
3-500Z)

$ 10.00

10.00

2/$15.00

CHIP CAPACITORS

.8pf

ipf

l.lpf

1.4pf

1.5pf

l.Spf

2.2pf

2.7pf

3.3pf

3.6pf

3.9pf

4.7pf

5.6pf

6.8pf

8.2pf

PRICES

I to 10 -

II to 50 ■
51 to 100

lOpf
12pf
15pf
18pf
20pf
22pf
24pf
27pf
33pf
39pf
47pf
51pf
56pf
68pf
82pf

.99*
.90*
.80*

lOOpf*

430pf

llOpf

470pf

120pf

510pf

130pf

560pf

150pf

520pf

leopf

680pf

180pf

820pf

200pf

lOOOpf/.OOluf*

220pf*

lB00pf/.0018uf

240pf

2700pf/.0027uf

270pf

io,oaopf/.oiuf

300pf

12,000pf/.012uf

330pf

15,000pf/.015ijf

360pf

18,000pf/.018uf

390pf

101 to 1000 .60*
1001 & UP .35*

* IS A SPECIAL PRICE

10 for $7.50
100 for $65.00
1000 for $350.00

MATKINS JOHNSON WJ-V907: Voltage Controlled Microwave Oscillator $110.00

Frequency range 3.6 to 4.2GHz, Power ouput, Min. lOdBm typical, 8dBm Guaranteed.
Spurious output suppression Harmonic (nfo), min. 20dB typical, In-Band Non-Harmonic, min.
60dB typical. Residual FM, pk to pk. Max. 5KHz, pushing factor. Max. 8KHz/V, Pulling figure
(1.5:1 VSWR), Max. 60MHz, Tuning voltage range +1 to +15voUs, Tuning current. Max. -O.lmA,
modulation sensitivity range. Max. 120 to 30MHz/V, Input capacitance. Max. lOOpf. Oscillator
Bias +15 +-0.05 volts @ 55mA, Max.

Toll Free Number
800-528-0180
(For orders only)

(fVI^l^ elect roi|ic$

164 Z3 Magazine • February » 1982

TUBES"

TUBES

2E26

2K28

3B28

3-500Z

3-1000Z/8164

3CX1000A/8283

3X25Q0A3

4-65A/8165

4-125A/4D21

4-250A/5022

4-400A/8438

4.400C/6775

4-1000A/8166

4CS250R

4X150A/7034

4X150D/7035

4X1 5QG

4X250B

4CX250B/7203

4CX250F/7204

4CX250FG/8621

4CX250K/8245

4CX250R/7580W

4CX300A

4CX350A/8321

4CX350FJ/8904

4X500A

4CX600J

4CX1000A/816a

4CX150QB/8660

4CX3000A/8159

4CX5000A/8170

4CX 100000/8171

4CX15000A/8281

4E27/A/5-123A/B

4PR60A

4PR60B/8252

KT88

0X362

DX415

572B/T160L

811

81 lA

81 2A

813

4624

4665

5551A

5563A

5675

PRICE

TUBES

$ 4.69

5721

100.00

5768

5.00

5836

102.00

5837

300.00

5861/EC55

200.00

587 5A

200.00

5881/6L6

45.00

5894/A

58 . 00

5894B

68.00

6080

71.00

6083/AX9909

80.00

6098/6AK6

300.00

5115/A

69.00

6146

30.00

6146A

40.00

6146B/8298A

50.00

6146W

30.00

6159

45.00

6161

45.00

6291

55.00

6293

100.00

6360

69.00

6524

99.00

6550

100.00

6562/6794A

100.00

6693

100.00

6815

300.00

6832

300.00

6883/8032A/8552

300.00

6884

300.00

6897

400.00

6900

500.00

6907

700.00

6939

40.00

7094

100.00

7117

175.00

7211

15.00

7289/3CX100A5

35.00

7360

35.00

7377

44.00

7486

10.00

7650

13.00

7843

15.00

7868

38.00

7984

100.00

8072

350.00

8121

100.00

8122

77.00

8236

15.00

8295/PL172

PRICE

$200
85

100

110
15
5
45
55
10
89
14

100
6
6
7

14
11
70

125

110

110
35
55
15
75
17
60
34
11
67
75

250
58
4
12
55
50
85
30

300

NOTICE ALL PRICES ARE SUBJECT TO CHANGE WITHOUT NOTICE !!!•!

TUBES

8462

8505A

8533W

8560A

8560AS

8608

8624

8637

8647

8737/5894B

8807

8873

8874

8875

8877

8908

8916

8930/X651Z

8950

6BK4C

6DQ5

6FW5

6GE5

6GJ5

6HS5

6JB5/6HE5

6JB6A

6JM6

6JN6

6JS6B

6JT6A

6KD6

6K66/EL505

6KM6
6KN6
6LF6
6LQ6
6LU8
6LX6
6ME6
12JB6A

PRICE

$100.00

73.50

92.00

55.00

57.00

34.00

67.20

38.00

123.00

55.10

1000.00

260.00

533.00

12.00

1500.00

45.00

10.00

00
00
00
00
00
00
00
00
00
00
00
00
00
00
50
50
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00
00

1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 H 1 1 1 1 1 n 1 1 1 ! 1 1

5.00
4,00
5.00
5. 00
5.00
5.00
5.00
5.00
5.00
5.00
5.00
5.00
5.00
5.50
5.00
5.00
6.00
6.00
5.00
5.00
5.00
6.00

"WE ARE ALSO
TUBES NEW/ US

LOOKING FOR
ED ECT."

WE BUY SELL OR TRADE

Toll Free Number
800-526-0180

(For orders only)

^^^L? electroi|ic$

^See List of Adverttsers on page t ^4

73 Magazine • February J 982 165

"MICROWAVE COMPONENTS"

MIPfllJAVl COWGHEVIS

All

7tM

HeiK SHmt

7010

Mcive S«iffxt ,2 t« ?,«Olz

JUL

QTO^

ikiit« Source

$11

orosi

itolH S«yi1^ 7. OS 16 ]DGH£

07091

ik>4K^ ^6yr?€ |?.4 to IB^t

CUSZQK

VaridbW Atirny^tor

24)6-Z0

VtnaBle AttcnwiaEar Q-ZOdB .5 to l&il lObf

jum

I6H-60I

Var tattle AtteniMtAr D-60cfB 1 to mii lOw

AftW

46S4-Z0C

Vartat>1e Attcny^ator (}-limK I to 4GHr IDk

AHU

»e4^20F

Veni&le AttemittDr O-ZIMB 7 to il£i^f

Aifre*

SMpler Aticfiuitor 1 to Z&H 0 to SOd€

AHrtd

U$2

SMfi1*r Attftiuitor 2 ta 4QU ti to SOdBi

Alfred

U51

SMvtkr AtC^mMtor 4 to SS^E 0 to 50dB

jtomcofi

aODD-6754

Adapter X to SMK S.Z to l2.4eKz

JlKrican

202D-fieOO

Olrectioml Coupler .5 to IGKz edH

Bow ton

4i'4a

PiM^r Dittctor

CmxHiI Dyn«ii1ci

30?:j

Directional Powr Detector 60wfwJ/l^wrff^/2?5-40Cknc

Coaxlil Dynmlci

302S

DlrectlOJiil Power Qe tec tar eQwfwd/i&wrev/ni-l'ianE

FXR/Mlcrolab

erw-A2i

Coupler

F)tB/>1tcfolab

XP-AJ^

Crystal Detector

FXft/Microlib

SI 64 A

ViriabU' Attenyatar 0~&DdB 2.^ to :].tSail

FJtR/Hicrglib

N414A

Frei^ucn cy Wet#r 3.ff5 to llCHz

FJtR/MiCfOlib

G01A07

Adaptigr

FWHlCrtfllb

G£OLe

Adactf-

Gentril MkroMfVt

N40EA-3

Power Detector

General Mlcrcwave

Nno-20

Directional Coupler 2 to 46Kz 2QdD
li}D:l k>^vldtr ik tc Z5DW

Serve rj J MIcrowivf

4276-2

Heirlett PicUfd

BZBIA

Adapter d to « 5. 95 to 5.85Gc

Htwyett PicUrd

H^IA

Ai^aprer h to i« 7. OS to lOGc

Hnlett PAck«rd

XZ91A

Miptrr I to N fi.f to 12,46c

Heir1«tl. Ptclttrd

Hl292e

kUoif'f IQ to t^Gc

Hfiilecit PicMnJ

NK292A

Wapt«r IS to 22Gt

Htkf1«tt PtcUnl

»Si

Motw Source If 3U/60HC

H«if1ett P«cUnl

fi347A

Moue Source 3. »S to l.SSl&L

H«Hl«tt Ptchjnj

H347A

MHt l4^rcc 7. OS to 10^

KChIeU PtChird

5347*

KD-lie Source ?.t to l^^SGc

HtM]ett PKfcAfd

tWM

Moite Source S,? to lZ.4£c

KNwIetl P«t*nJ

itoit* SADTCt tOOlc ta 4Cc

Htw^tU fictind

3S5t

Virt*b)e Attnuator . Sh DC to Ific

HivlEte Picking

MOD

im Pn% FHter 4100^:

Hptlett T>K4urd

G3aZA

VartAbU AtttAMtor 0 to 5IW 3.95 to %.^%c

HMltCt ficfcird

JJKA

rariabte itiemiator o to sOdS 5.6S to &.2&c

Umlrtt P*curd

fsezA

far»*6l* Attenuator 0 to SQiB 12.4 to laSt

NwtfU Hcllt^

1»SA

fertal^le Atte^LMtiir 0 to 50tf 8.2 to 12.4GC

^icwTett PiCUrd

41lA-^U>

i rer for 411A

Hsilttt PlckJird

M«21A

Crntal 5et«tor 7. OS to IDGc

ftcwlett Piciard

MI21A

CrytUl Detector 7. OS to 10^ Kitched Pair

HchIfU HcUf4

iM^a

Crrvtal Dttcctot 7.05 to lOSc llitcrie^ Pair

H&m\tt* Packird

tT»

therBHtor feunt For 430 SErrei IIM: to )06c

Hi«f!flt Pitkir^

MftiA

Mrritur Munt 1.9% ta ^.fiSSc

ftWltftt P^KkAPd

^ias»

OcUctor Hnmt S.es to B.2Gc

H^litt fackant

JUGA

TlWVlitor Houht S.SS to a.2&c

Hewlett ^ftclbtrd

nmt

Th«f^ttor Hount 7. OS lo lOSc

Hftflett f>iek4rd

K«7C

TI*ei^1itof "teufit It to 2Me

HeifVvtl PicMrd

PM7B

TftiTplstor Hownt 12.4 to 185c

Hewlett P*ck»(^

X4&7A

Thiffllitor tount &,2 to l?.4Sc

Hewlett pAckird

I487B

ThcrmHtor Hount S.2 to l2.4Gc

H«ylBtt P«ckAr4

G&32A

Freqi,»ene;y Heter 3.9^ t? S.flSGc

Hnlett PicUrd

H53ZA

Frequertcjr Heter ?.a5 to 106c

HMl«tt PftcUrd

JS3ZA

Freqijency Meter 5.3 to a.2Cc

HpHlttt pAckird

nS^M

Frequency Meter 10 to 15Gc

Hatlttt Packard

P53ZA

FrA^ucncy Meter 12.4 to iSGc

Kevlett P«qlcarEl

X532A

Frequency Meter B.2 to l2.4Gc

Hewlett Packarij

536A

Frequency Meter ,94 to 4.ZGc

Htift#tc PAClcinJ

G752D

D^rectloriil Coupler 20da 3,95 to S.flSGc

Kiwl#U Packard

Xr52A

Dlfectlotial Coupler 3<ja 8.2 to l2.4Gc

Hewlfrtt Packard

J(752C

Dli'ectlonil Coupler 1MB B.2 to L2.HiC

Hewlett Packard

17 KD

Street lonal Coi^pler 2QdB S^S. to t2.4gc

HnUtt PdCUrd

7i£0

Ouil Olrectionil Coupler .94 to K97SSc 20iiB

HcHlett Packard

767Q

Dual Dlrectlotial Coupler 1.9 to 4(ic ZOdB

Hewlett Packard

7870

mF«tton«t detector 1,9 to 4.1Cc

Hevlett P«ck4r4

G91QB

Tafirttittlon 3,95 to S.BSGc

HewUtC Packard

J1914B

Moving Load 8.2 to I2.4Gc

HevlttC P§QkMri

ZS30A

Senter O-^Elllitor

McHlftt Pich«P4

35(13

Nkrowavc imiUh SOQii: to I2.4& SPSf

Hvlett Packard

843 lA

Sandjiati Filter 2 to 4Gc

HCMlett FKkird

8416A

Aandpast Filter B to l2.4Gc

Healvtt Ptckird

«7lA

RF Detector

Mpileti Packaif4

$4TZA

Crrsut Detector .Oi to 18&:

Hotflett Packard

SfWk

Pin Hodiilatior l.S to 4.S6c SOa

Hotlett Packard

«}J3A

pin Nadwlat^ 3.7 to &.!&: 3SA

Mariett PacUN

lOlOOB

l«r*tfMtlQft no otai

Hewlett PkUp^

IDSS5A

Pr«a^p. / to inoic

HHlctt ficure

Il6bDA

Trtcklfif G#neratiir SNmt

fl«ifl«tt'^acUP4

IJfcgiA

Lf»Her

H«lEtt Packard

DiKI

frantHtof Tett Jig

>*HUtt ^atkard

33Rnc

Hh Absorptive Nodylator

PalBtt Fatfcard

93110*

mcfwive Switct) iOGnc ctp iemt

Mskleit PacLtard

PS-IWl?*

■HcrOH^ve Saltch DC to iBGc SPQ^

HfwUtt Pacur^

3909eA

HtcrCM4«e Swittft

KJ-Qi'437n

0 t4 lOldfi variable Attenuator DC to I&C

woai

Itolili Source

El/

7921A

Noise Swirce 10 U MWc

Kiy

7921A1

iolsc Soiree 10 to tOOQMc

Lectronk

K53A

Tube Ht^.Mttenuator And 2ft2S

WLU^e^l

t Band Lu-d

PCCA

7H-1S?

Directional Coupler 4 to 6&c 20dO (flarda ^Q44ft20)

mrrimtHi

AU-2fiA/

SO 1162 iTirlablc Att«iuator

Hicrotech

fl49?Z

Mkfowave Switch

HlUUry

AT-ea/ijPH

Horn Aflienna ft. 5 to 9,66e

Hllltarjr

U[S-52a/U

MB Attenuator

Minla

703

Variable Atte^udtor 0 to 40da

NinSi

79ZFH

Variable Attenuator 2 to 2.5Sc 0 to l7dB nU.
£.5 to 12.4GC 0 to 20dB nln.

Mtrdi

2301-20

Directional Cojipler 2 tQ 4Gc: ZCMB

lUr^*

2301-30

Directlofiil Coupler 2 lo 4Gc 3{MB

Mtrdi

2366

Var1al}1e Directional Coupler 1.2 to r.4Gc 7 to 12

Ntrdi

2EG3

Htnda

28«

NirdA

2979

BlOlrectlonal Coupler 4 to SSc 20dfi

Ninii

3002-10

Directional Coupler .95 to ESc lOdB

Narda

VKl?'2d

Direct locitl Coupler .S5 to 2Gc ZOdfl

Hanja

30G3-1D

Directional Coupler 2 to 4&; lOdB

Hir4i

3003-30

OlrtctlOMl Coupler 2 to 40c JOdB

iti^i

30W-KJ

(Hri<t1o^«l Coupler 4 to lOGc IWfi

1100.00

100.00

100-00

ISA.OO

200.00

IDO.OO

50.00

75.00

200. oe

ZOO.OQ

JM-QCi

7S.0O

75. OO

?5.0O

5Q.0O

50,00

3^.00

35,00

450.00

35.00

lOO.OO

75.^W

35.00

50. OQ

15. DO

3S.O0

75.00

7^.00

200. QO

^50. 00

250.00

3E5.00

Z50.00

300,00

tfO.OO

so. 00

^00. 00

soo.oo

350.00

3ZS.00

J5.00

50.00

200.00

400^00

75.00

85.00

ISO. 00

50.00

IJS.?^

155/00

65.00

SS.OO

100. DO

500.00

4O0.D0

500.00

400. OD

3SO.O0

600.00

200,

200.

200. OC

200.00

50.00

50,00

200.00

?5.Da

100.00

50.00

IDO.OO

200.00

2DO.00

7S.0O

1D0.00

400.00

350.00

2S.00

eoD.oo

SD.OO
3flO,00
150.00
lOC.OO
100.00

75.00
100,00
100.00
250.00
200. «}
250 00

50.00

sa.oo

100,00
75.00
50.00
25.00
35,00

100.00

250.00

100. OQ

100.00

40,00

too. 00

100.00
100. QO
100. M
100. OO
100.00

.00

166 73Mag3zinB * February, 1962

TEST EQUIPMENT

loon ton

Alfrgd

SyEtron Ogmrter
S Infer

Po1«r«4
tHilinmO

rtcvltit Pi£Urd
NiMltte PlCkAi^
flMTttt fiekird
Haiti vie PAir44r4

Z3fM

Hi«ll'l«tt

WW leu

HtvUtt

wt^lett
Hewlett

Hmtett
HmUu
Heyl ett

Hewlett
Hewlett
tt*wletE

Ptci.4r^

Ptcfcftrd

Packird
Pdckird
PackdriJ

Packard
Pdckard
Pdckarij

Hewlett Piduird

Hewlett PAckord;

Hch-Utt

Meviett
Hffilett
«e*il*U
K«ilitt
hfiilett
Hewlett
He«Tett
i^ewlett
Hewlett

Hewlett

Ptck^rd

Ptc kirt
Ptcurd

fKktft

PtClcjrd
Pickjnd
PicUf^

Hewlett ^i^UH
Te^tronii
Hicro Tel
TekironlA

T£5I tOmPtgifT

Z02J AN FM Si anil ^neritur 195 ccr 77Mli CIO^OO
2a7J/Z07H AM FM Slgnil ^^neritar jnd Un^verter

lOOKHi CO 55HC Ai^d 19S to 270Mc 600.00

?3i Het«i*odyiiB Cchn verier 200 ta UOOrtc £00.00

HCH5 NOfiUOr 750.00

eOOD/7D&L Swe«p Nctworlt Analyzer lOOKNf to 40Ge AOO.OO

KSG'ZZS^A Stindird Signal Generator F^r ZS ?^O.Q0

FW3 Frwiuency Meter 20 to lOOOMc 150,00
1037/ U9 1 A Frw^u«ncy Met^r 0 to SOHc wUh Plug ir^ td SOOHc 500.00
SPA3/?5A Spectfutii Arfl.lyzer IKc td ^5Kc And e Q-£ CainpianiOn

Sweep Senerttar 0 ta ISMc ^ni PS- 19 Powr Supply 1500. OD

6SB StaiKlird Sigttil Gefierator ?5Hf to 351^ 250.00

140 SUndifd Oevfatior; NEter IS to lOoOnc 200.00

KSa-Z Si|na] gcnerttor £l^ to «&00f1c 5A0.00

S?4 Hfcroweve Swept Oscil liter fl to l2,4Gc ?5a.OO

U(3^ T|»e Intersil Hug In fd.OO
TS^lOll/ Wm* Spectrins tnalyi^r iWc to lOSc irilh

Alien Filler FJ35/F33fi/F3aT/f33e/F3*l/liac♦^
Aticfivatipr Cllin/C]t4WOI409 «mJ lEech Adapter

UGl?3W0GI24O/UG124iyifitZ4Z ISOQ.DO

StAAdind Signal CamrMtot IfiCc t» §IMc 300.00

Peiw Ai^iHner 10 U MSMt i.5ii«tts 400.00

PtMCT A^Hfier 10 tc SOOfc i.iwtUf iOO.OQ

24IMI Smccp Qeneritor 4.5 to llOPto 4110.00

4iX vmi £0 70Gm7 400.00

4I5D sun Heur Z 50.00

41 tS PMcr Pleter lOMc to 40Gc ISO. 00

60«A 5tgnil Generator SOKHf ta frSHc TOO OO

£OeO SljAll Gen»rdt{}<^ 10 tD 42Qfle «O0,0O

6Q8C Si«^l Generator ID to laOHc SOQ>PO

60af S{9<v4^ Generator ID to 4a<Mc l$O0,OO

bOSF Sfgml Generator ID to 4S5Mt 1^00,00

6I2A Signil Generator 450 to l?J0Mc 500,00

ei4A Stgnd! Generator 90D to 210DMc BOO. 00

&16A Signal Generator Lfi to 4.2(iC 400.00

gl^B Signal Generator i.a to A.iQt: BOO. 00

file A Signal Gen ere tor 2.B to 7.6Gc 400. 00

^ISB Signal Generator 3.8 to 7.6Cc bOO.OO

&ZOA Signal Generator 7 to U4k ^QD.OO

62 ja Tett Sat 5925 to 775QH£ 5*>0,00

fi26A S4gnil Generator 10 to ISGc 2000.00

£2aA Signal Generatm- 15 to 2l<k^ 2500,00

94m Freqti^cy Ooubler Z6.5 to 40Gc 1000.00

J5»m Portable Teit Set lOOO.OO

5249. frmxitftdf Cdintter 0 ce 50llt 1000,00

525^ ^l(#g In For Above 20 to lOlK 100. OO

5252A Plvg Ift Fflf «e)Oif& lOO tu J5<3Wt ?00,00

52536 Plug In F«r itwv« 50 to 5O0Hc 150.00

52S4t PI 119 I fi For above 20QMc to 34c 750.O0

S2fiQA frti^tm^f Otvider to I2.4fic Tor atmre 1000.00

S^saA Hif9 Iff For above Tim Inteofl 100.00

53Z7B INM ifkd Freqyencj Pteter t& S5<ilc 150(>.OQ

01f5«3« H UAd Scwntor/Teat Set 7.t Cn 8.5Gc 1000. 00

491 !&o#ctn0) Afidl/ter Solid St4te lime tn 40Gc. 70QQ.G0

MSmOl HlcrD^ve J^ceiwer to 40ee DIgiUl RhAoiA 90O0.QO

l%fi ^tatiil fieneracor JSOttHj to SOHc 150.00

Telontc ?001 Sweep/Sl^riift^ Uei^erator ^^$t

J 305 5 to ISOOHc AuUlpleI.?/3^^5 1 to 20QdHc Varidble Hart(er,}34D AF /Output

AttCfiuttor 50 atiu,i3^iLi J^ DeteLtor,J3€OA Rite ModiJlatiofv.JJ^OOUplay Prcoesslng. lOOO.OO

TeloBlc 2003 Sweep/Slqtiat Generator Sj^tttn'S

3303 5 to SDOWt B weep. 3323 1 to 2000Mt VirJable Har1<er,3343 RF/Output 50 ohms. 3 340

flf Output/Attenuator 50 ohms ,3350 SF Oetettor.3360A Rate K)ElulitiQn«33?D Display

Praces&ing. 750. 00

(^^

Karda
Hir^
Nirdi
Njirdi

liarda
Harda
Harda
H«rd«
Nirda
Hftfda
Harda
ftarda
Mtrda
iirdi

Nirda
Kardla
Harda
Kirdt
iirda

i«rii«

Pffi

rao
mo

PftO
pao
Pro

Quantdtron

Hadar Design

Sage

Safe

Sage

Slwrry Hicroline

StDddart

Systron Danner

Tefetronu

Tcttroniii
Tektranlt
Telonfc
Tekscam
Trans to
MaveTiFie
Havel ine
iitvetei
MvlntcMl tt^.

Kaiiitfictiir^
^ftO

Hewlett Pact*rti
Hfvfett Pacta rd
Hewlett Packard

Hewlett Paqkard

3004-20

3032

3033

3039- ?0

3040-20

3043-20

3044^20

3544S2n

3045C30

4035

22006/

22007/

£2011/

eaoii/

ZZVT
22SW

22539/

22574
2M§9

22«76/

l«0ft4.10
ClOE
17101
20M

sesA

C3414

116001
Xfi2e4
SlOO
A-?filOC

[Jl*3«

752-3

2503

7?53-S

l^Q]

9D515

[)&U19A

550

lUOA

DTrectional

Coupler 125 to 75Qftc ?0(JB

Coupler 240 to 5DOi4c 20dB
Coupler 2 to 4Gc 20d&
Coupler 4 to SGc 20dB
Coupler 3.7 to B.JGc 2'OdB
Coupler 7 to lZ,4Gt 30dB

Coupler 4 to lOGc 20dB
Hybrid .95 to 2Gc 3de
Hybrid 2 to 4Sc 3ija
Directional
Directional
Di^ett■i^^n4l
Oi recti anal
Directional
Directional
Hybrid 3dB

3043-20 Directional Coupler 1.7 to 4Gc 20dB
3D43-30 Oirectlona) Coupler 1.7 to 4Gc 30da
3003-10 Directional Coupler ?
3003-30 Directional Coupler 2
Alllptei^ K to n B,2 to 12.4&C
4014-10 Directional Coupler 3
4015C1D OlnBctiona^ Coupler 7
4013C10 Direct iontl Coupler 2 to 4€f: lOcQ
IHrcctiOtfiAl Coupler 2 to *Gc lOOB
»ir^£iofii1 Coupler 1%.S t« 17.1&:
4014C« Directional Cwftler l.ftS to dEf fitfl
4015C30 OlrecticMiel CoipTer 7 143 l2.4Sc 30i«
Olr^tional Coepltr t to IKc 300
ViFiable Atte4t4#iter S.S^ to B.2fic 0 to iOdl
VAriablp AtteAu>atO^ 12.4 to ia& 0 t4 fiOdO
Slotted Lire wUh Probe 4 to lOGc
Frequenci' Meter B,2 to lOGc
90^ Twist l& to 2£.5Gc

to 4fic IDdB
to 4Gc 30dB

£5 to s&c \om

A to inc lOtt

,00
00

t^vovter 7 to l0.6Cc

Crystal Switch

Tnermistor Mount 3*2 to 12,4Gc

fiodustub Tuner

Variable Attenuator

Directionftt Coupler

Coup^ er

Mixer

Directional Coupler 4 t.D SGc 3dB

Frequency Meter 5,614 to fl.2Gc

IDdB AttenuatOf

Tunable Detector IB to 2£.5Gc

Saaip^lng Nead

Saapling Head

Pulse Gef>eraCor Held

170 oiie V4H««te Attenuator
TI!f4]7-34-SCDZ Bandpass Filter
5YF2S0-50O-1AA Ti#i«bl« Bandpats Filter 250 to SOOfc

*m70ioo sp&r swi tch

£01 Mapter I to TIC i.2 to 12.4«C

9009-10 ftirec:t3«»I CQUp\mr 4 to lOGc lOffl

5070 0 to 7«A Variable Attenuitur

2fr« *X to mm Viirit^le Attemiatar

^^»/33o^/

33oa/U0fiA

0OM

eo5c
eo9e with

IQO.OC
ISO. 00
150. CH]

150,00

125,00

100. 00

IDO.OO

150.00

125,00

150.00

100. DO

100.00

100. DO

35.00

?5.00

B5.00

75.00

100^00

125.00

100.00

too.

7S.

ISO-

100.
too. 00

125,00
50,00
75. CO
50.00

125.00
M.OO
50.00
75.00
fS.QO
25.00
50. ao

200. DO
35. Tin

JOOiiJi'

Can

M^DO
15.00

250.00
25,00
3S,00

101.00
?5.00
50.00

Frice

1250. «}
JOO.OO
400. 00

809E btith

Detcriptloii

20 to ioamu

Standing Mave Pe tec tor And Hatched Le^d

Slotted tine SOOWii to 4Bij

Slotted line SOOitii to 46Hz

W6& Slotted lirre 3 to L2GH2/Ciei0e Slotted

Line 3,95 to S.aSOMi/JaiDB Slotted Line

5. as to e.2aHr/)(aiOfl slotted Line 8.2 to

\2AGHz/P&im ^latteil Line 12.4 to JBGHJ/

tZEiP, £ H2KtA Adapt«r/H)(?926 Tapered

Trans it1on7444A Prote 2,6 to laCHi/and d

447B Probe/HttlOB Slotted Line 7.05 to 10.5

BO£B Shotted Lirte 3 to l2GHz/Hai{)G

Slotted J-ine 7,0& to id.sghz/xsidb slotted

Line a.2 to l^.4G#1ir/HK?92@ Tapered Tranjition

H to X/H2ai* i K2&lA/^Wlth Probe. H^^l^ 5S0.0Q

900.00

Toll Free Number

800-528-0180

(For orders only)

electrof|ic$

(602) 242-8916

2111W. Camelback
Phoenix, Arizona 85015

t^4^

t^See Ltit of Advertisers on page U4

73 Magazine • February, 1982 167

FULL LINE ALL PARTS & COMPUTER PRODUCTS

P.O. Box 4430M
Santa Clara, CA 95054

Will calls: 2322 Walsh Ave.

(4QB) 988-1640

Samt div itilpmirt. Rrst Wrm pans only Factory t^td ClvajiJite«d
mcni;v bach Quality IC's and o\im componefm at factary pdc^

ELECTRONICS

tNTfGRATED CIRCUITS

Phone orders only (800) 588-8198

■JK
I.M»IAN<AH

LH3CibH
LM11IH-N

JJ
»4

CtMOUl

cmooft

CMOID-

4 116 ZDOns Dvntmic RAM B $15,40

ELICTHOMIC SYSTEMS KITS

A|lple Ptrlphtral Kiti

SERIAL I/O INTERFACE 0 to 30.000 tjauri.
D T B . Input & DiilpuJ from rnonlt&r or basic, or
usEAppla as IntuHtQfiiil Teimjnal, td orly (P:N 2^
SH.S5, Kit (P/N 2A) 151,25, Assembled [P/N

PHOTOT^PrNG BOARD (P/N 79€7^ 121. H.
PARALLEL TRIAC OUTPUT BOARD 8 inacs,
each can swIEcti 11 QV ^ lo^dS. Bd only (P/t^
2 'Oi S19 20. KMP N 21DA) $119.53.
OPTO'ISOLATED INPUT BOARD 8 inpuls. can
be driven from TTL logic, Bd only |PN 1201
$15,65. Kit IP N120Ali».»&.
lAtf rtaci Hm

SERIAL PARALLEL INTERFACE Bidireetionai.
Baud rates from ttO 10 19 2K. sw sateti^
polarity oi tnput and outpui strobe. 5 to Q di^
bits, 1 CH 2 flQp bits . parity odd or t vtn or none,
all ctianctOT conlun a si^t bit. ^5 4 -12V
required Bd only (P.N 101} %^^M. U {?H
tQ1Ai S4Z.tl.

RS'232.ni IMTERFACE BM<rtclional. n-
qufres rl2V. «it (Pm 23ZAJ tl.K.
RS-23^'20l1lA INTERFACE BritifRt«ntL 2
Dassii« otfo-^oiilMl cktutts, m (PM T%m
S1I.9S.

PROM Eraser

t\- ii.. 25 PROMs «n 15 (Wfiufes U*l?3vlolit,
iSlcfTitiifrd 25 PROM capacity WM iwdh
liRKi UB.^' 6 PfiOM cipKiy OSHkUL vef-
lion S7t.SI) I wrth timer liOi.U)

NICad Battery Fixer Charger Kit
Opans snorbBd cms tm won i ttoiid a ciiarpe ana
j tiivi charges ft>ern up, afl in one hit w-lufl parts
snd instructHHif . tS.ftS

Z80 Microcomputer

16 bit 1/0, 2 MH? clock, 2K RAM. ROM Bread-
board space. Excellent for control HarR Board
S2B.S0. full Kir 199.00. Monitor SZfi.OO. Power
Supply Kit £35.00, Tiny Basic Ufl.U.

Modem Kit $60,00

State of the an, ori^., answer Ha tuning neces-
^ry. 103 compalible 3Q0 baud inexpensive
acDusrio coupler plans included. Bd only
S17.0C Article in June Radio E/ecfnon^cs.

60 Hz Crystal Time Base Kit $4.40

Conwrts Hiqnai clocks from A€ Ime frsqiaency to
crystal time base. QjtstandinQ accuracy.

Video Modulator Kit $9.95

Convert TV s^t into a high quaJity fnonltor w.o
atfectm^ usa^e. Gomp. hit wf ul^ mstruc

Mult}-volt Computer Power Supply

Sv 5 arnp. =18^ .5 amp, 5v 1 i anvp. by
Samp. 12v .5 amp, -1?y option itSv. rllv
aftf^^ilated BasicKit^S 95. Kitwitfi^ssis.
antallhanhiarf SS1.99LAiMS5.0Qsh{p|iir)Q Kit
of hard^re HLOe, Woot^grain ose $10.01.
Si. 50 shqjping

iype-M4al1c by Votrax

1^ to speech synthesoif mth unlatiltad vocabu-
lary, hmh-^ t&t to spMdialootiQvn. 70 10 100
Ms pe^ secoml sp«edi qraOMa^iBrp RS232C
tmeil9ce (319.00.

1602 18K Dynamic RAM KH $143.00

£xpsnddbli Sq b^ Hdoen refresn M.tJob^ up v:-
4Wtw^tii^S^s.AdEl. 1»<RAMS25Q0
S-100 4-^ ecpansiOD $ 9 95

S4i|)er MofFhor Vt .1 Sou rce Ltitlao £ 1 5 00

RCA Cosmac 1802
Super Ell Computer 5196,95 '

The Soper Ell IS a smj^ single boari} GOrnputw i:har
(toes many big ihirigs Ms an «ceiiflt computer
lor tnming vtf fc^ ^anwig proTanrniig wih is
machine fsngmoe m ^ its eis^ ea^nM
wWt tillllonil nwnwry. Ftll Batlc. ASCII
Ktfbovill^ 1M» ctiarader generatJOii, elC,

ROM fTunHoF; SMb imd Aitodft diSfA^S', SviQic
step^ Opbonid adttress dtspbys; PtPMf Supply*
Audio MtfMie' and Spfiton My si^Bbil tir ^
s. rui oocufiwfxXNin.

"^ &iar ar ndydes i HOH monitor tarpni-

g^r^koading, """t) rt rnnfttm Tritr WfTia F
STff ^ pragnm dttHnlii wticfi Is not «-
dhJded n oltiers at the sane price^ Wrtti SINGLE
STEP you cm lee ihe micfopfocessor cihp oper-
SBiQ Mth tfifl niqije Ouetf address vd dan tus
disffai^ Mwt. 4imeg ifid Mv ^secutpig inr
striKtons Abo, CPU fTVde and instruciioft t^de
are decDdec a^ dkspHyed on a LB) ridicators.

An fCA la&t vk^ grapftio atp Hows you to
DQtinK] m your o«vn TV Mtti an netpRns^ve video
mniuMOr to do ira|ihic$ ^nd gams There e& 3
tpaiier iiiluii mduded (ik writing your onm
m^tsic Of using many muse prpgram^ already
wtitiert ttwsp&ker jimpiifi«rfliiyatobeiisedtd
6ttm ma^ lor control purposes

A 24 key HE^ ktytuard ^ndudt^s 1& t€X ksys piLS
loatf, rts«t, nA, waH, ti^, memory poj/tad,
monitor seiad ^nd itngle slftp Unje, on board

dispii^V^ piovide ouipul and optional littgh md low
■lUrwii. lhe\t is a 44 p^n ^ndaid cannector siot

Super Expansion Board with Cas

This Is truly an asioundioQ ^lue' Tttis t^rd fias

been designecl to allow you to decide ficw you
want d optioned The Supef Expansioit Boanf
comat wHh 4K or low power RAM lully address-
able anywhsfe in 64K wrth buiH-ln memory pro-
t^ and R cHSsafli lirieriaes. Provisions have
been made for aij other optiois on Ihe same board
and H fits neatly inta the iiardwood cabinet
alongside the Super Elf Tfie board includes slcts
Tor up to 6K of IPfiOM (2706, 2758, 2716 or It
?7l6] ^nd i$ lully sockeied. EPROM can b« u^ed
for Hie monilor and Tiny Basic or other purposes^

A IK Super ROM Monilor SIS. 95 is available as an
on hoard option in 2706 EPRGM which has been
pFBpnsgnmmad with a prograni ioadfir/edilor and

error checking mult I fita cassette read /write
soltware, {reiocjLjOie cassette lilel another exclu-
sive from Quest It Includes register save and
Foadout, block mowe capability and video graphics
drtwf with blinking cursor Sreak points can be
used with the register save feature lo isolale pro-

Que$l Super Basic V5.0

A new enhanced ver^tan oJ Supet Bai^e now
avHilible. Quest wa^ the first corn par^y worldwide
to shjp a M size Basic for ia02 Sysiems. A
complete tonctton Super Sesic by Hon €enker
including floating point capability wilti scienEific
mitation t number range ± 17E*|. 32 bii inte^et
±2 billion: myib dim arrays, string arrays. Sitrlng
manpilation; cassette LD. save and Icid, basic,
data and m^hrne langitage programs and owr
75 statements, functions and operations
H^tf improved taster vermin- ncludirig (t*
nuntticF ^nd ess^nttalj^ unlimited firiihii.
Also an exdusive user expanoad^e commind
Liiifaiv
Senaf and Paralt^t i o routines induded

Sii|ier flasic od (^ss«tte £55 00.

for PC CXI& anj a 50 pn csnwiQr slot Iqr the
Quest Super Expansan Boird. Pomr supply and
sudets for aO Cs 317 induded plus a dcniM
127 pg. msmxim imnat whiii now iidjdes
over 40 pgs of sottMarv li^. {ndufiOQ a S8is o(
lessons Ui hdp get you sorted wd i muse pro-
03n and gtapiks target ifsnt Itoiy schools
and urvwfstKs are usmg the Sit^ @l ts a
course of study 0B4 s use i tar trailing and
Fl£D.

REfinndec other QonpitasDrty oObt Super B
fabiEsdadifiian^Oosf ornottf il Conwan
bribi« rou btiy, S^v El Kit $106.9$. ligi
aMmu option SB.SS, U^r addnen o^ion
SiJL teton> €^iK^ wtth dniKi wd taumn
pie»s^tes foam p^Dij $2Aw£l Al metf &«armi
CatNTiet piiiBd and sl( soeened. with foom lor
5S-1D0 boards and po«er supply 157.00. WCail
OMenr Memoff Ssver Kii Sfi 95. All k3te and
options liso Dompletely ass9n(M and fested.

duesjda^, a sottwai piiiUion lor ^802 oom-
piigf users is avaiitile by subs^ipdon tor $12^00
per ^^ issuer, Srqie fasws Si 50. testes M2
bound SIB 50

MocM^ Videg Gr^i^ics S3.50, Sanes and Musio
S3.0II Dup S liiW^^ SS.SO. Siarship 4K cas^
setlE WM.

Free 14 page brochure

ol complete Super Elf system,
sette Interface $89.95

Qrarti bugs ^ms^. tf>en follow wtth single step. H
you have the Super Expansion Boanl and ^per
Monitor the monitor is up and running at the push

01 a button.

Other or* Doarti options indudf Penllel Inpul and
Output Paris witli hill handshabie They aNow ea^y
connection of an ASCII keyboard to the jnpul port,
fIS 232 and 20 ma Current Lopp for teletype or
other device are on boaid and If you need more
mfifDory there are Iwo S-100 slots for static RAM
or video hoards. Also a I K Super Monitor ^rsion

2 with video driver for lull capabilfty disp|:ay with
Tiny Basic and a video interfeoe bqard PBrallol
I/O Por^s $BM, RS 23? $4.50. TTT 20 ma l/F
S1.95, S-IDQ S4.5a. A 50 pin conneclof set with
ribbon cable is available at $13,95 fo^ easy con-
nection between the Super Bf and the Sufwr
Expansion Board.

Power Supply Kit for the Domplets syslem (see
Mufti -volt f^jwer Supply below)

Reckweil AIM 65 Oomfiuter

6bii£' od:ieu Sim\t mam wnn tuLi ASCII keytioard
arirt 20 Golymn rnermal pnmer 20 char aFjihanu'
me IK display FiOM monfor Mly eaipandaUe
I419.IW. 4K vgfiion $449,00 4K Assemtsier
laSJOO BK Base Inferprdff SI&OO

Specyi nm^n power supply 5V 2A 24V .5A
assem m trame ISV.DO, Molded pi ash c
enclosure to fe boin aim fiS and power supply
55?. 90. MM 65 IK m caOt%1 wittt power supply
swidi. luse. cord ^sem S55§ 00 4^ S579 OQ
A^ ^SOOO AIM ^40 « 16t( HAM aitf mcfiilor
$121500. flAM Boy- - ■ ^^^ ItlS^ iA
IlISi VDWWdw S113.MJ. A&T

imM Comtme AIM 65 m Dftn bndc^e mm
po«per sop9ily fSll.flO SpioaiPadcageFtice 4K

Ai¥. m Sue. poiKf ^m^ cabin:' unm

AIM 6S^iM,S¥M^upit Bf iM fy : - '"

Ell II Adaptfif Kit IZAM

P!u^ into EW II pmvid ir^ Supef EH 44 and 50 ptfi
plus S-100 bus expansion (With Super Ex-
pmsKMi) Huh and low address dispiay^. sta^
ifvJ mute L£Ds d^ioniJ S18.00.

Super Color S-10t) Video Kit $129 J5

BtparuS^sle to 2SG i 19^ higl] lesotutioo cofor
gupfiics. 6047 wih il abpby modes oKnpviter
ajftroied Memoiy nuppsf. IK RAM uiviS-
aUeto6K B-100 biis 180? 800(1 SD85 Z80
etc Oulofs: Send iDf iiatl«ni pricifi§ margin
pmgran.

TERMS: $5.00 min onfer US, Funds. Ctlii resldems add G%1ai,

$10 JO min, VISA and MasterC^rtt ac&epted. S1.0Q insurance opffiRiL
Shipping: Add 5%; orders under S2S.00— 10%.

FREE: Send for your copy af our MEW 1981
QUEST CATALOG . Include 88c Stamp.

168 73Magazme • February, 1982

lansa^j the first name in Counters !

9 DIGITS 600 MHz $129

CT W Kit W da) pun t * 1^

HiiliTTlnir 1Li9

cnr I. taMto-ttrmt thm

The CT-9Q is the ma^r versitile, feature ptckti^dl cuiihter ivaLtable for leis
ihvi $300,001 Advanced dcifti|n feituFes include; ihrec sekcuibk stat times,
nine di|iu, gate indicAtor tnd ■ unique displiy hok) functign which huldi (he
displsyed couni alter the input ijjnAl is removetf A\&<x m. lOmHzTCXOlJme
bue is used which enibln euy zero hut ciJibritkiti checks tgiiiut WWV.
OptiofiiJty; in ini«nuU nic&d b«ii«ry |i*ckctteiiL«l ttent b&te input MRd Mtcro^
power high stxbiliiy cryiul avta time bue are ivaiEabit The CT-90,
peffdi'inance ym can count ool

SPECIFICATIONS:

WIRED

Rjuifc
Seniitivity;

Reiolulionc

Diipliy!
Time bue

20 Hi to 600 MHz

Less ihan 10 MV lo 150 MHz

Less ih^n SO MV l£) 500 MHz

O.J Hi (10 MHz range)

LO Hz (60 MHt range)

10 0 Hz {600 MHz nnge)

9 difjn 0 4' LED

SiMiKlarES- 10 000 mHi, LO ppm 20-4<rC

0|iaoiuil Micfo power ovei>0.! ppm 20-40'C

S-I5 VAC « 750 mA

7 DIGITS 525 MHz $99

SPECIFirATTONS:

Ftimie:
Seiuitivity:

Iljeiolutioix

Dtipliyt
Tune bti
P^*ec

20 Hz to 515 MHi
Uas thanSO MV lo 150 MHk
Lc« than 1 50 MV to 500 MHz
JO Hf {5 MHz rfingc)

IOO.OBmSOO MHi range)
T(tiffm0 4" LED
LO ppi!BTCXO20-40=C
12 VAC « 250 ma

WIRED

The CT-70 breaks the price barrier an lab quaJtty frequency count«n.
Deluxe fealurei such as three frequency ranges -each wil h pre- BLmpliric it ion,
duaJ Kleclible gatetimes^ and gate activity indication make measufeinents a
loap. The wide ^nequency range enables you to accurately measure signaJi

from audio thru UHF with 1 0 ppm accuracy - thal't .0001%! The CT-TO it
the answer lo all tout meuurvmeni ne«(js^ in the fteld. l$h or hatn shaclL

PRICES;

CT 70 wired, I yearwarranEy

CT-70 Kit 90 day parts *ar

ranty

AC- 1 AC adapter

BP>] Ntcad pack + AC

adapter/ chargei

S99.95

7 DIGITS 500 MHz

MJNIIOO wired, 1 year

wafTiJity %19.95

AC' Z Ac adapter for MINl^

100 13S

BP-Z Niead pack BAd AC

adapter,!' chjugcr 12,95

$7995

WIRED

Hef«'t a handy, generiJ purpof^e counter thai provides mo«t couniir
funcLioni at aii unbelievabJc priceL The MINMOO doesii't have the fulL
frequency rinie or Lnpui impedance qjiaJjtie& found in liigher price imiu, but
for basic RF signal itieaiuremenu^, it can't be bead Accurate measuremenli
can be made frnm I MHz all the way upfoSOQ MHz with excellent sensiuvity
ttuoogliout tJw range, and the two gate timet let you seiect the moliuion
defined Acki the nJcad pack af?uon and the MIN I- 1 00 makes an ideal addilioA
to yoyf tool boi for 'in-ihe-fiel^' frequency checki and rcpain.

SPECIFICATIONS;

Range;

Seniitjvity:

ttesolutioEE:

Dupliy:

Tunc base

I MHz toJOO MHz
LeiU than 25 MV
100 Hi{%ki^u'^}
LO KHi(fiwi gate)
7 digjti. 0 4 LED
2.0 ppm 20^40 C
5 VDC 4 200 QU

8 DIGITS 600 MHz $159

WIRED

gPECIFICATIQNSi

Range:
Sens 111 vityr

ResotutXHT

Diiplay:
Tane base
Pcrwen

20 Hz to 600 MHz

Leas than 25 mv to J 50 MHz

The CT'SO \% i verutile tab bench counter that wflJ meuure up to600 MHz
with 8 digit preciiion. And, one of its brit features ii the Receive Fr&quency
Less iha* 1 50 flsv 10 600 MHz Adap«r. which tunu the CT-50 into a digiul readout fof any receiver. The
I 0 Hi (60 MHj ringe) ji ^r a ^ JL v.

TOO H iliOO MH I adapter ti easily proframmed lor any receiver and a simple connectMm !o the

B diam 0 4" LED receiver's VF O is alJ thai is required fof use Adding the recei ver adapiet in no

2.0 ppm 20-40 ~C ^'T Etm^ the operation of the CT-50, the adapier can \x convenjaitl>'

1 10 VAC or 1 2 VDC twitched on or ofC The CT-50> a counter thai ctn ^mk doubJe- duty!

FRJCESr

CT'50 wired I yearwuraniy

CT-50 Kii, ^ day pajfti

warramy

RA- i , ivGciver adapier kit

RA'J wuiedandpfe-profrajn-

med fsend copy of receiver

schema tic ji

SI 59.95

T 19,95
14.95

DIGITAL MULTIMETER $99^

WIRED

PRICES:

DM^TOO wiml t year wtiiflfi^

S99,95

DM^700 Kit, 90 day paiu

warranfty

79.95

AC-1, AC adaptor

393

aP-3. Nicad p«ck ^-AC

idapte? charger

19,95

MP-L Probe kit

2.95

The DM'70C ol^feri prDfessional qualltv pterfornuince ar a Kc^hhytst pricr^
Features include; 26 different ranfpi and ^ Functiona, nil arranged in a
convenieni, eauv to use format- Mruurements are diaplaved on 1 lar^ 3^
difit, ^ tneh LED rndout with jutomafK decimal placrfnrni. •uicTmaiic
polarirv. ovrrrantfr (ndtcaOMOft and over load procccrion up 10 1 250 vc^ejon aJ|
raitRA. makmg it vmualtv ffoof^fvoolf The DM-700 Looka ^etri. a kandsosne,
fci Hadt. rifffped AftS caa* wnli coftvemenc fewaoafeJ* nk hail makes tt an
ideal addition (o k\\ slia|i.

SPECIFICATIONS;

DC/ AC voha: lOOuV to 1 KV. 3 range*

DQAC

cufTcnt 0.1 uA to 2.0 Am|»&, 5 ranges

Rc535iance D. 1 ohms to 20 Metohnm ^ ranges

impedance IQ Megohins. DO AC vohi
Accurwry: 0, J % basic DC volu

Power 4 C ceHa

AUDIO SCALER

For high resotuiio^ audiO measuremenuiH, niulUphej
UP in frequency,.

• Great for PL tonei

• Multiplies by 10 or 100

• 0 01 Hz resojuiionf

$29.95 Kit 539,95 Wired

ACCESSORIES

Telescopic whip aAietuia- BKC plug. .«..«..*

High impedance pmbe, light toading

Low pas3 probe, for audio measure mentdi. .*^r
Direct probe, general ^urpoie usage . . , , ^ , . . ,

Tilt bail for CT 70, 90, MINMOO

Cojor bui^t c;alib'rBtioii uniti calibratea counter
against color TV signal

V 4' t V * a 4 I

S 7.9J
15.93
15.95
12.95

COUNTER PRE AMP

Fof measuring rxtremelv weak signals from 10 to LOOO
MHs. Small *tie, fHiwercd hv plug ETnrLsiormer- Included,

• Flat 25 db gain
4 BNC Conneclort

• Great fo'' snifTing RF Hrjth p4ck-up Ux^

S34 95 Kit S44.95 Wired

remsey etectranic's, inc.

2575 Baird Rd. Penfield. NY 14526

PHONE ORDERS
CALL 716^586-3950

-%wran*r *« D Aia^-fliMM ftl 1 1 0 0-»-**« »dW I % COO a4*l

^5*tf List ot Advsrftsefs o/> if9g& tj4

73 Magazine • February, 1982 169

2822 North 32ncl Street »1 • Phoenix Anzona 8bUUB • PhGne602-9S6-9423

CHOKES

AND

INDUCTORS

4/1.00

.3uH
.56 uH
1.8 uH

2uH
3.1 uH
6.6 uH

52 uH

55 uH

2/1,00
Z4mH
22 mH

MHIer 9055
50-120 uH

Summlta 20K359
455 kc discrfmination
Miller #8e06/34H-650

TUBES

6KD6

6LQe/eJE6

6MJ6/6LQ6/6JE6C

6LF6/6MH6

12BY7A

2E26

4X1 50A

4CX250B

4CX250R

4CX300A

MINIMUM ORDER $10.00 NOT

4CX350A/8321

4CX350FM/8904

4CX1500B;8e60

811A

6360

6939

6146

6146A

6146B/d29B

6146W

6550A

^06

8950

4-400A

4400C

572B/T160L

7289

3-1000Z

3*500Z

82uH

91 uH
1B0uH
220 uH
270 uH
410 uH
450 uH

68 mH

$2.50

* 5.00

6.00

10.00

6.60

4.00

4.69

29.99

45.00

69.00

109.99

INCLUDING

100-00

100.00

300.00

20.00

4.69

30.00

7.95

9.00

12.95

10.00

14.00

13.00

145-00

145.00

44.00

39.99

229.00

141.00

SHIPPING

500 pes.
1000 pes,

LED Diaptay
FND 357, 362 red
C.C.

TIL312 LED Display
Red

Assortecf Heat Sinks— 3 each.
For TO-3, TO-220, T(>66 & 105.

CAPACITORS

DIPPED SILVER MICA CAPACITORS

5pF $.40

120pF

$.25

10pF .25

150pF

.25

12pF .30

210pF

.40

15pF .30

250pF

.40

20pF ,25

330pF

.40

22pF .25

470pF

.40

24pF .25

SOOpF

.40

33pF ,25

560pF

.40

50pF .25

620pF

.40

75pF .25

82DpF

.50

82pF .25

SSOOpF

1.00

100pF .25

Quantity pricing also.

ASSORTMENTS

Electrolytic Caps.

All types (new),

50 pes. S6.99

GapacHors, Resistors & Diodes

Assortment

(All New) (Not Junk)
100 pes. 4.00

250 pes. 7.00

12.00

20.00

2/100

2/1.29

12/1.99

Assorted Potentiometers

*rAII new" not junk. Some with switch,

some with 1/4*' shaft.

#3.5.283 30 for 4.00

#S.S.284 100 for 10.00

New Miniature Toggle & Rocker
Swltcti— 25mix. $6.99

New Assorted Toroid Cores

10 big & small 4.00

TO-3 and TO-66 Used Power Transistors
High voltage switching in CRTs.
30 pes. Good/Bad? $ 2,00

100 pes. 10.00

Hardware Assortment

1 pound mixed screws, standoffs,

washers, feet, Insulator 5.00

IC Assortment

50 New IC's. Not Junk.

7400/S/LS Linear, DTURTL etc. $10.00

House numbered AYS 2376
Keyboard encoder chip— 88 (keys)
same as OR 2376 6.99 each

5 Way DC Voltage Adapter
Selective voltage: 6, 9, and I2VDC.
input voltage— 11 5VAC $9.99
WALL TYPE TRANSFORMERS

115 VAC input

6 VAC @ 10 MA 2.99

12 V @ 700 MA _.. 4,99

15 V@ 300 MA. _,a99

115 VAC & 220 VAC input
15 V @ 300 MA. , , . . . . .3.99

DL-1416

4-Dig»t 16 Segment Alphanumeric
Intelligent Display with Memory,
Recorder, Driver $14.95 each

Fuse Holders

HKP type for 3AG J9 each

UHF Varactor Tuners— Sony

19.99 each

TeledyneSerendip

Solid State Dip Relay

Part#A641-1 2.49 each

RCA TRANSISTORS
80684

40235

AM PER EX/MOTOROLA

RF TRANSISTOR

BFR91 J5

MRF901 2.00

170 TSMagMzine • February J 982

RF Transistors

MRF203

MRF216

MRF221

MRF22e

MRF227

MRF23e

MRF240

MRF245

MRF247

MRF262

MRF314

MflF406

MRF412

MRF421

MflF422A

MRF422

MRF42d

MRF428A

MRF42e

MRF426A

MRF449

MRF44gA

MRF450

MRF450A

MRF452

MRF453/GE185

MRF454

MRF454A

MRF455

MRF455A

MRF468

MRF472

MRF474

MRF475

MRF476/C1306

MRF477

MRF4dS

MRF492

MRF502

MRF604

MRF629

MRF648

MRF901

MRF902

MRF904

MRF911

MRF5176

MRF8004

BFR90

BFR91

BFR96

BFW92A

P.OR.

31,00

10-90

12.65

3.45

12.65

15.50

34,00

34.00

9.20

20.70

13.80

25.30

36.80

41.40

46-00

46,00

15.50

15 50

12.65

13.90

13.80

15.00

17>25

19.90

21.83

16.00

19.90

1.00

3.00

2.90

11.50

3.00

23.00

1.04

2.07

3.45

33.35

2.15

8.00

3,00

3.00

2.10

1.30

1.65

2.20

1.15

eFW92

MMCMSid

MMCM2222

MMCM2369

MMCM2484

MMCM3d60A

MWA110

MWA120

MWA130

MWA210

MWA220

MWA230

MWA310

MWA320

1,00
14,X
15.65
15,00

15.25
24.30
10,00
10,00

laoo

10.00

10.00
10.00
10.00
10,00

Transistors

2N2e57

2^2857 J AN

2N2949

2N2947

2N2950

2N3375

2N3553

2N3818

2N3866

2N3866JAN

2N3866JANT)(

2N3925

2N394a

2N3950

2N3959

2N3960JANTX

2N4072

2N4427

2N4429

2N4877

2N4959

2N4976

2N5Q70

2N5071

2N5108

2N5109

2N5179

2N5583

2N5589

2N5590

2N5591

2N5635

2N5636

2N5637

2N5641

2N5643

2N5645

2N5S42

155

3.60

15.00
4.60
8,00
1.57
5.00
1.30
2,50
4.00

10.00
2.00

25.00
385

10.00

1 ao

1.30

7,00

1.00

2.30

15.00

18.40

20 JO

4.00

1,70

1.00

4.00

6.65

10,35

1360

10,35

12,00

15.50

9.20

15.50

13,80

8.00

2N5849 20.00

2N5942 40,00

2N5d46 19.00

2^5862 57.50

2N6080 9.20

2N60ei 10.35

2N6082 11.50

2N6083 13.25

2N60e4 15.00

2N6095 12.00

2N6096 15.50

2N6097 1 7.25

2N6166 40.25

2N6368 28.75

A210/MRF517 ZOO

BLY38 5.00

40280/2N4427 1,30

40281/2N3920 7.00

402e2/2N3927 17,25

MMT74 1.04

IC SALE

400CJ 36

2805HC/1405A 1.00

74LS27 25
P3101/82525/74S289 1.0O

SCL4013A/BE .25

MC14001BCP .25

MC14017BCP .75

MC14012BCP ,19

MC14023BCP .20

MCI 4027 BCP .39

MC14069BCP .39

MC14093BCP .60

MC3420P 1.00

MCM10152L 5,00

MC7408P .19

74LS05PC .20

AD580 1.00

8T01B .60

CH164A .25

CG388V .25

74LS20F .20

748SN .39

DS0026CH 1 .00

CD 4013BCN .30

CD 4028AE .49

CD 4040 BCN ,80

CD 4069CN/74C74 .30

MM74C74N .40

CD4015CN .75

DS/DM 8839N .60

DM75L51N .75

TL0-61CP .30

SN7420N .25

ZBOCPU 4.99

2708-6 1.00

2516/2716 2.50

2732-6 10.00

2102 .50

21 1 4-2 & 3 8/16.00

4104 a/16.00

D21 16/4116 8/18.00

D8257 3.00

MC6845 10.00

2S0CTC 4.00

280SIO/Oor/I 8.00

ZBOPIO 4.00

74LS273 .80

74LS373 .80

74LS374 .80

74LS245 1.40

74LS367 .40

74LS14 .60

7aM06 .39

78L05 .30

78L15 .30

78L08 .30

79L12 .49

LM317T ,1.99

MC7808T/LM340T-8 .49

7805/LM340T-5 .89

7812/LM340T^12 .89

7ei5/LM340TO5 M

7824/LM340T-24 .89

06202 20.00

D8212 1.00

D8214 2.00

8251 3.00

TMS1000NL 2.00

MC1306P .75

MC1414L .29

LM/SN 1458V .40

LM565V .30

LM309K/7805CK 1.00

MG6852P 3.00

RC74LS51N .15

SN74LS74N .20

PT 14826 2.00

EC1422B 2,00

LA 4220 Sanyo 1 .00

SN75427N .30

N8T28N/MC6889 1.00

D3232/MC3232 1,00

ORDERING INSTRUCTIONS

Check, money order, or credit cards welcame. (Master Cliarge and VISA only,) No personal checks or certified personal checks
for foreign countries accepted. Money order or cashiers check in U.S. funds onfy. Letters of credit are not acceptable. C.O.D.—
$2.25^-52 35 shipping.

Minimum shipping by UPS is $2.35 + .35 per $100.00 for insuranea Please allow extra shipping charges for heavy or long items.

All parts returned due to customer error or decision will be subject to a 15% restock charge. If we are out of an item ordered, we
will try to replace it with an equal or better part unless you specrfy not to, or we will back order the item, or refund your money.

PRICES ARE SUBJECT TO CHANGE WITHOUT NOTICE. Prices supersede all previously published. Some items offered are
limited to small quantities and are subject to prior sale.

We now have a toll free number, but we ask that it be used for charge orders only. If you have any questions, please use our other
number. We are open from 8;00 am-5:C)0 p.m. Monday thru Saturday.

Our toll free nymt>er for charge orders only is 800-528-361 1.

MINIMUM ORDER S10.00 NOT INCLUDING SHIPPING

»^64

2822 North 32nd Street. »1 • Phoenix. Arizona 85008 • Phone602-956-9423

p'See List of Aifvefttsen art page f N

73Magaz(ne • February, 1982 t71

CALL TOLL FREE

3:
c
m

-I

IS BACK!

Dentron Clipperton V

Big power on 2 meters!
Self-contained A.C. power supply
500 watts from 4-CX-250 B final
CALL FOR SUPER SPECIAL!

Dentron RT-3000

Panasonic RF-3100

111

NAV369 95

AC/battery FM/MW/SW radio
3 1 band operation
All quartz synthesized tuning
5 digit frequency readout
Linnjted 2 year warranty

CALL NOW!

$299.95

<
0

III

<
C£
O

• 3Kw capability

• Roller inductor

• Power/VSWR meter

• Bypass capability

CALL FOR SPECIAL DISCOUNT!

%-r^

DM81 Dip Meter

Frequency range 700 kHz-
250 MHZ (7 band)
Function — inductive coupling
capacttive coupling
Compact size

CALL NOW FOR PRICE!

z
o

X
m
3]

"Our Most Popular Scanner
the JIL SX-100"

o
o

rNAV $399.00

16 Channels, 30 54 MHz; 140OB0
MH;; 410-514 MHz Digital Ciock
Date Display 110 V AC or 12-
16 V DC

Seeh Rale Fast ^Och/sec
Stow ScH/sec
Bfight Green 9 Digii Ffequeocy Dis-
play Ext Antenna Jack Exi
Speaker Jack Large Top Mounung
Bracket Scan Rale Fasi Sch.sec

Slow 4ch/&ec
Scan Delay Time Variable 0-4 sec

UNBELIEVABLY PRtCED
ATA LOW $199 95

^KEIMWOOD HC-1 0

Digital Clock

Attractive, functional layout, with switch buttons on
slanted panel. Cabinet is trigonal pnsm shaped for
stability. With a pleasing color cx>mbinatton and
modern styling, the HC-lO will enhance the appear-
ance of any ham shack.

CALL NOW FOR PRICE I

31
O

Computer

Call for Discount Prices.

Amateur Radio

AMDtK
APPLE

ATARI

BASE?

CENTRONICS

COMMODOflE

DC NAVES

NAZELIINE

LEED€M

MACRO T RON ICS

MAXELL

MCflOSOFT

MOUNTAIN HAROWAHE

NEC

NOflTHSTAR

pamasonh:

SANYO
5VNCOM

AVANTI
SASH BOOKS
eCAHCAT
BENCH£R
CALL BOOK
CUShC«AFT
OAIWA
DENTRON

DRAKE

ETO

huSTlER

HV-GAIN

ICOM

KENIVOOD

MIRAGE

PANASONIC

ShURE

TEMPO

TEt£X

fRAC

tA£SU

fll

ANTE£NNAS

PRICES SUBJECT TO CHANGE AND AVAILABILITY

OPIR . .

WE TRADE

WE EXPORT

C€NTifl

Nationally Advefiise<l Value

1840 "O" Street Lincoln, Nebraska 68508
In Nebraska Call (402) 476-7331 - a

V/SA

172 73 Magazine • February, 1982

LINKS •REPEATERS • THANSMIHERS
RECEIVERS • PHEAMP8 • CONVERTERS
TRANSCEIVERS • POWER SUPPLIES • PA'S

TRANSMimSs QUALITY VHF/UHF KITS

AT AFFORDABLE PRICES

FM-5 PC Board Kit ^ ONLY $159.95
complete with controls, heatsink, etc.

SAVE A BUNDLE ON
VHF FIW TRANSCEIVERSf

1 0 watts, 5 Channels, for6M, 2M, or 220

^^V^>%

\0'

^«"

h^Z.y^'

r' ■¥

HIGH QUALITY FM MODULES FOR
REPEATERS, LINKS, TELEMETRY, ETC.

• R75 VHF FM RECEIVER for 10M. 6M.
2M, 220, or commerdal bands. 4 fantastic
SB[ectivity options. Kits from S84,95 to $ 1 1 9-95

• R45OUHFFMRECEJVERfor3e0-520MHz
bands. Kits in selectivity options from $94.95

• R1 1 0 VHF AM RECEIVER Kit for vhf aircraft
band or ham bands. Only S84.95.

COfl KITS With audio mijcer and speaker
amplifier. Only $29.95.

CWID KITS 159 bits, field programmabre,
clean audio. Only S59.95.

A1 6 RF TIG HT BOX Deep drawn alum, case
wfth tight cover and no seams. 7x0x2 inches.
Only $18.00.

SCANNER CONVERTERS Copy 72-76.
135-144. 240-270, 400-420, or 806-8 9 4 MHz
bands on any scanner. WifectAested On^ $79.95.

TS1 VHF FM EXCtTER for lOM, 6M, 2M,
220 MHz or adjacent bands. 2 Watts contiiv
uoys. Kits onfy S54,95.

T451 UHF FM EXCITER for 450 ham band
Of adjacent Kits only $64,95.

VHF & UHF LI NEAR AMPLIFIERS. Use on
either FM or SSB, Power levels from 1 0 to 45
Watts to go with exciters & xmlg converters.
Kits from S69.95.

VHF & UHF RECEIVER
PRE AM PS. Low noise.

VHF & UHF TRANSMITTING CONVERTERS VHF & UHF RECEIVING CONVERTERS

For SSB. CW. ATV, FM, ela Avaflable for 6M. 2M,
220,440 with many IF input ranges. Converter board
kit only at $79.95 (VHF) or $99.95 (UHF) or kits
complete with PA and cabinet as shown.

20 Models cover every practical rf and if rarvge to
Nsten !o SSB. FM, ATV. etc. on 6M. 2M. 220, 440, and
1 1 0 aircraft band. Even convert weather down to 2M!
Kits from $39.95 and wired units.

VHF Kits from 27 to 300 MHz. UHF
Kits from 3O0 to 650 M Hz. Broadband
Kits: 20-650 MHz. Prices start at
SI 4.95 (VHF) and SI 6.95 (UHF). All
preamps and converters have noise
figure 2dB or less.

Call or Write for FREE CATALOG

(Send $2.00 or 5 IRC's for overseas MAILING)
Order by phone or mail • Add $2 S & H per order
(Electronic answering service evenings & weekends)
Use VISA, MASTERCARD, Check, or UPS COD.

mironics, inc.

65Q MOUL RD, • HILTON NY 14468

Phone: 716-392-9430 ^3a

Hamtronics" la s reglstarod trademark

RAMSEY

ELECTRONiC'S
•^62 Inc.

PARTS WAREHOUSE

We now have available a bunch of goodies too
good lo hypass items are Jimiied so order today

2575 Baird Rd.
Penfietd, NY 1452<

716-586 3950

MINI KITS - YOU HAVE SEEN THESE BEFORE NOW

HERE ARE OLD FAVORITE AND NEW ONES TOO.

GREAT FOR THAT AFTERNOON HOBBY.

MINI

MIKE

A »upflf high p&rtDrmance FM wjre-
tes$ rnlkt kit! Tranfimits a stable
signal up lO 300 yar<f} with except
TiOf^tl fiu(^«0 quality t>y means 4I tt;^
by^lt 411 decirei mike Kit mcJiudes
case mikff o*i-off swrtlch int*nf>a
bftttfffy irHJiupef tnifrucrions TfKiS
IS me finest unit avatiainv

FM 3 Kit $14,95

FM 3 Wired ana Teklftd 19.»S

Cotor Orgafi

$e« music come
alive' 3 d^ifferent
tights llick^F 'Mvith
musiC- On^ l^Qht
eactt for, high,
mid-range and
lows Each indi-
vidually adjust'
ab^e and drives up
!o 3O0 W runs on

Complete hit.
ML-l
$i.95

•ifw4*n Uv^ulmittT Kit
StaMa luiUAit S ^^n» on S>-

Led BHnkf K\l
A greai aitorntion get-
ter which alternately
flashes 2 Jumbo LEDs.
Use lof name badges.
buttons, warning
pAMt lights ^iriythingi'
Runs on 3 to 15 vO^tS
Comp*ei« kti Bt-t
%3M

Super Sleuth

A (ly per sensihv* ampl I -
ti(?r which wiH pjck up a
CMn {irop at 1 5 teei' Greai
tor monitonnig baby's
room ct &% general pur-
posfl ampiifi&f Full 2 W
rma output . runs on 6 to
15 wo' 15 u^es fl-45 ohm

speaker
OomfMtB kit Bi^9

CPO-1

Runs on 3- 15^ VdC 1 wall
Atamn. Audio Oscillator

cnit 1 KHZ qood tot CPO
Complete kit tS-tS

Call Your Phonp Order in Today
TERMSi Saiislaction gLaianitt?ed or monnj
letunded COO add $2 00 Wllnfmum ofde
S6.00 Orders iinUm $10 00 add it 1 SO Add b'
lor pot»tayt;, insurance, hartdling Over-jt'd
add 15*= N V re^idenis ddd /' la*

CLOCK KITS

Vchjf 0^ fSToritM are here tg^ln. Over T,OtlO Sold to Dele
Wm orte at ifie Qan>g and ortler youn lodayt

Try your hand at buildcng the finest tookmg c^ock on the
market >ts satm fifKsh anodlzed aluminum case looks great
anywhere, whife six 4" LED digits provide a highly readable
display This is a complete kit, no extras needed, and it only
takes 1-2 hours to assemble Your choice of case colors:
silver, gold, black (specify).

Cfock lilt. 12/24 hour. DC-S $24M

Clock with 10 mtn 10 timer 12>24 hour. DC-IO S29.95

Alarm cJock. 12 hoyf only. DC-8 129.95

12V DC car ctock, DC-7 S29.95

For wired and tested clocks add $10 00 to kii price

SPECIFY 12 OR 24 HOUR FORMAT

f M Wlreteta Mik* Kil

Trannmits up to 300' to

any FM bioadcaM ra^

iiio. uses any lype of

TYiike Runs on 3 to 9V

has added sensthve mtke preamp

stage

FM^I kit 13.95 FM-£ltit $*%5

Type FM-2

Unhfcrul Timer tttl

Provides the t»a$ic pani and PC
|>oard f'^Qyired 10 providfr a source

at praciSiODi irmmg af<d pu^^
generation Use$ 5S5 timer IC and
includes a range ol paria for moBi
timing needs

UT-S Kit SS.tS

Whisper LiQhl Kit

An interesting kit, small mike
picks up sourids and converts
them to light The louder the
sound, the brighter the lighl
includes mike controls up to
300 W. runs on PO VAC
Complete kM WL-t
S6^S

Mad Blaster Kit

Produces LOUD ear snattenng and
atterFttoo getting siren like sound
Can supply up lo 15 watts of

ObfKSKioys ayflro Runs on S-IS VDC

Me-t Kit

S4^£

Tone Decoder
A complete lone deco-
def on a tmgle PC
board Features 400-
5000 Hz adiuslable
range via ?0 turn pot. voltagi? rr.j:,
iation 567 IC Useful for toucfi-
tone buj'st deiection FSK eic
Can at^o be used as a stable tone
encoder Runs on 5 to 1? volts
Complete kit T{>1 $595

Car Clock

TTie UN- KIT. only 5 i»t^r eofineeltona

Sirefi Kit
Produces upward^ a:nd downward
wail characteristic of a |>oiice
Siren 5 W peak nudto ouiput. runs
on 3-15 volts, uses 3-45 ohm
speaker
Corrplete kit, SM-3 S2.95

00 Hj TlmnF QtM

Rii<n3 on §-M yE3C Law cufrBni |l)ini»i <
iflin wortlfi JccuFKr TB-^ Wit U W

HeicB ft tupor laQkinq rugged Jind accurnEe kuio croch wh^cri \'i n tnmp to build aird
ir^stnil Cloch movsnienT n cflmplelely aiiemhlitd - yot* oniif iOild*i+ 3 wnfe-$ and 3
^witchi04 lAhM Eboij-l 15 mmLitiDi' Display la bnighr f^teen with lutomntic bfighrnest
coriirQit E^inoiaceM — asfyief vclji ol 1 higfily Ftidftbtr display div ^^ itt^ht Co^e$ ^'^l
Ht^n trmifi iAodi^^ii ^iMtni^MiTV CAt^ AtKcti can b* ftllacfted 5 diHirvnl wa^ysi>itg? t^ilvO
iaf» Cnonet or s^pr ei«ich o' ^>d casa (icMcifvi

OC-3*<1 1?hQUftorfnai t21 •»

DC 3 «ifK] vvd tP5t«d

Cutcmdar Atarifi Ctock
The Clock mat s tot it ait B- 5 LEDs
i2?4hour loooie ?4 r^ou^' alarm J
year caliendar itansiTy tjachup bdei
JOIS mor« The super 7Q0i chip is
UE&d Size 5K4K2 inchpF Complete
kii less case [not ^^^a^iAbtei
DCS 134.95

Under Oa«h C^f Clock

1:3 I^mMfcaK^t^AKaaypii^ -#«tu««i

a tu'^VOHil} LEDS luBtiKt- I., -1- "^1 attt

3 4M4 hdCNkiip. d<«pNlf b««n*.» *«Cn ^imttofi •mr

T„rtivf ii^iriicl^i>fl OpIiO'^Ai i^im-mHT aluomil^riilii
•CJjMi'li ili^^ljir 10 At1^&)f ni 1-^)14 l««ll
t>p. 1 1 eioeli wiil\ tfit{j bi^Llt'i^ fir n k,il

1>S/A 1 «)iiTim4r muAptVT HM

Add $1000 4«»v KhH T«tt.

PARTS PARADE

VIdffO Tfrmlnii

• ' • ' r 1*1 f c CHitsmpi"] irgrtft nhfun- atc^fio rr^rm
■ r-. i^* icemp^STi- tr'ffi.MiaiLiflii feai-j^es *■
-d IWlWOf temp J3U!»* i»''D prf&fi-

^-0tf and ^vfivrtf E i . : ^ aS^N p*ui fsaradg ^

»- 1 -- *^fi| Bfift comirttf ifn(tiii«><U4j<>

-MA«i etfffl kit itdd Me de hat

«»*

'■' ■ ■ ■Ft'?' trf

ffpUMif *SC<fh#rfrO*Ti3»"«:|TV

V^LrPE". rmritMkrd h-nc ai^d B«uil

_. The aii4<«fl«ttiJ> i>T ^fl><'<H win

HIM
114 fS

I'M

IC SPECIALS

LINEAR

38D

56€
5#?
T41

3it4
«3i

4»

t 3S

11 SO

II. ill

$ 49

tt»
11 M
(1 90
in 2%

t so
s se

I7 9S

%2K

4011
4013
404«
4049
4059
4511
451a

CMOS

Ifffi

.50
.50
$1.65
.50
$9.00
S2.0O
51.35
$1.75

READOLFTS

fNp»rrsio5CA %m

MAN 7?.HPrT» irC A 1»

Ni^fMi *rcA i.«

TRANSISTORS

jNim* »#M c* F 1 i^i da

7^4403 mp C^F IVII H

7nu,]oi#«iC*r 11.11011

JMBQtC*' 4«Mt

ztoTTi D^ii 5ACOA ti at
HPN HKM trfw ^*f* fam.m

PHP 3»0i T^pf T>ft |«/»,M
?N:Wfi I.H

3iN»4e u^r l/4a.ee

TTL

74SCK)

7447

74n

7490

?4196

$ 40

$ .6S
t.50

1,50
t1 as

SPECIAL

72oe

72C7A

72ieD

710TC

5314

a375AB/G

7001

115,00
S 1^
$1?,S0
$ 5.50
S2TD0
$12.50
3 2.95
$ 2,95
S 6 SO

FERRITE BEADS

'111 W

Soektli

14 Pin 10/S2 OO

16 Pm 10/Sa 00

?4 Prn 4/S2.00

?8 Pin 4/S2.00

40 Pin 3/$^.Q0

ficftislQr Aii'l
AssorimenT of Popular values - %
watt Cut lead tor PC rn hunting. ^^■'
center ^o" leads, big ot 300 or

more.

$1.50

Switches
Mini ic^gie SPDT
Red Pushbuttons N '^

{too

it 00

r ivAdB

iafphones

ft of^m goQ0 tt)f vnm* ton*
«tarmcic»cU Mc

f ofiifi 5p««itef
ADpiQi « 1 di^m Hound

3 lor ia 00

Cvyitala

3&79&45 4UIHZ 11. SO

10 00000 MHZ tSOO

5 24BeaO MHZ SI.OO

AC Ad«p^l*n

cKv^ftfi.BK 110 VAC plug

Dllff «fKl

i5tlK#.20mA ft 00

16 VK # l€iOmA ft,M
t2 TK # 2»^A tJ 09

i4«4 9I»I* Butxtn
vmti buizer 4S0 hj M cfB lound
DJalpul on &<17 vdc Ml 10^30 mA TTi
epmpaiifelt |1,iO

Stug Tuntd Colti
Small 3/16'^ H^x Stugs lurngd cqii
aiurns, 10 for $1.00

AC Outlel

Panal Mounl with Leads

4/11.00

CAPAClTOftS

TAHTAlum

15tiF25V3/$1.00
1.8ijF25V3/ST.OO
22 uF 2SV 3/S1.00

ALUHINUH

>ClQO uF 1^ nadi^a^ t «a
UO wf »V A>.Bf I M

lie w# irv Ajui Ml eo

DESK CEIIAMIC
91 1&V divk Ifrtt M
< iSV 11 f 1 M

001 tiv n If ae
Ocr«r

Plodat

5 t V ^enef M/H 00

lN914Type 50/5 too

tKV2Afnp ilVOO

tOOV lAmp IS^SI.OO

25 AMP

100V Bridge
$1.50 each

Mini-Bridge 50V

1 AMP

2 tor $r. 00

PC-PC Cvnmtm Cer«mic IF FiltBfl

^5 flic ifKHrt pnya -9 vUc # 30ina Mini ceramic filt«ra t IcMz

'9r<ScerOiJuC«-lSwtfCi1S 3Sma 11.15 Q i^ 455 h;H2 S1 50 «>a

^SK 30 Turn Tc<m Pod |1 00
TK 20 Turti Tnm Poi 1 .SO

Tnr»irn*r C*^
Spri^iui! - 9-40 pl

Siibl« Poiypropyltn*

Audio
Preicalar

Maka high resolution audio
rrieasurments. greai for musical
instrumenl lunmg, PL tones, etc
MulttplJes 9udm UP in frequency,
selectable xlO or a 100. gives 01
HZ resolution with t sec gate
hme' High sensitivity ot 25 mv, 1
meg input i and built-in Mlermg
gives great per^OTmance Runs
on tv battery all CMOS
PS-2 kit $39.tS

PS'2 wire^ t^.9S

600 MHf
PRESCALER

Extend the range of your
counter (o 600 MHz Works
with all counters Less than
150 mv sensitivity specily -
10 Of -100

Wired, tested. PS-IB $59,95
Kil, PS-IB S44.95

30 Watt 2 mtr PWR AMP

Simple Ctass C power amp features 8 times power gam. 1 Wirt
for 8 out , 2 W in for 15 ouU 4 W in for 30 out. Ma n, output of 35 W,
incredible value, complete with all parts, less case and T-R relay.
PA-1 , 30 W pwr amp kH S22.9S

TR-1 RF sensed T-R relay ki! 6.9S

MRF-2MI 1fins43lor u uaed m PAO
a-lOdb^tm T50fflh£ I11JS

RF actuated relay senses RF

(1W) and closes DPPT relay

For RF sensed T-R relay
TR'1 KFt $6.flS

Ponvtr Supiily KII {,

Compi«ie triple re^uUfed oowm
supply jpfOw«d^ vsriiibi« fi ID t i vti-Kf «1
200m«vitl-*^an Acnp £;i Calient I04ld
rt^UilitiQn good Mt^fing nm) smaHl
ti£t tewtrsmtoriner^ r«!quir«5S3V
/# 1 A and 24 VCT
Complete kit PS-3LT U^%

Cry Mil lllcrophont
Small }" diameter 'a" Ihack
c^y^EAl mike cartndge $,T5

Cfi«)t Cofm*ct«r

Chassis mount
BNClype Sl.N

Mini RG-174 Coa*
10 It lor $1.00

Nice QuAiiry ti'&% s tw ft oa

%~ ^jMMf QiWl«in«is lOiortTM

A«l 0tC«VW» *e|C £4H IflM f-H4WiX
■in e«« I m pcT Vvm q Ug l}» {K^ ttJ»

Conn*c10f1
0 ^11 type go>ta£Dn1i»Cl» tor

pric4 7S ««

L»4i - your cht^ee ti>««se' specify

Mini Rftd Jumbo Red Hugh intensity fltd Tlfgimlriator Fted i/fl

Mini VeltOMv, Jumbo Yellow Jumba Green %/$i

V*i«cton
Molorcta MV Z20d 30 PF Noinindl cip 20-90 Pf - Turiible ringi <

JO Hc*i Of 1/11 00

OP-AMP Sp*d«l
Bt"FETLf 13741 - Off ect pin for pin 741 compatible but 500,000 MEG
Jnpul 2. super law SO pa input curr«nit io* power dram
50 tot onty Si.Oa 1Q lor SI QO

7«MQ
71MG

7?3

7*05

11,25

isa

t* 15
Si DO

Rvguliitd-rt

7S12
7815
TvOft

7912

SI. 00
t1 OD
tl.25
S1.25
S1.15

ftlwirtli Tubtfug Hubm

shnnh IQ' ■*" Gr^a! lor =p' -••', SO.'Sl.OO

iUn4 TO-42 HtH SInkt
T^tttninQy 8r|i^d $ for t1 W

Tr,

?M HMf Sinfci

3 iw %im

Opto Isolators - 4N2B type

Opto Reflectors - Photo diode * LED

S.SO t«.
SI. 00 M,

Mol«it Pini

WqIbm iJrBHjy preciit m i^rHjih cvf ? l^trfKl

cos lhNeloc«4li
naitiiinc* vcnei wiin iigriT £5D ohmt ia
ov«r 3 m*g 3 Ivr It.Ott

174 73 Magazine • February. 1982

"TOP QUALITY PARTS FOR LESS

It never fails: Someui-e calls you on the telupr.orit; .itnj yuu heeci to cliti-.w,u

' phones to get some infofmation. You put the phone down, go to another

phone and give them the information, then hang up. Oops! You forgot to hang

up the phone you first answered! No more phone calls for you until you discover

your mistake!! Or, the phone rings right in the middle of a serious talk with your

children, spouse, girl friend, efc. You have to lay the phone down, go to another room

to finish your conversation, leaving your caller in silence. Or how many times has one

of you r not-so-good friends asked you and your spouse to go out Friday night and you are

fl^^ 0 sitting there making all these weird gestures and rollmg your eyes. etc. Your spouse does

^■l^ not know whether to pour cold water on you or run screaming into the street. Well NO MORE

^^^ Digital Research is proud to announce the M.O.H-0,. the first patented, electronic hold control

for your home telephone Return to the same phone or any phone in your home and your party is

still there. All the time your party is on hold, they may listen to A.M.. F.M.. casette. T.V,, or any other device

you wish to hook up to M.O.H.O. No need to butcher your phone either. Only two wires to connect to your

existing phones. One wire to tip and the other wire to ring. For those not too telephonefCBlly inclined — one

to the red wire and one to the green wire. The M.CH.O, reisdes in an attractive box approximately 6" x 4" x

2", which may be placed anywhere. Now comes the fun part. You have just received M.O.H-0. (kit form takes

about 1 Vz hours to complete}. There are only two things to do: hook the red and green wiretothe telephone

and plugM,O.H,0, into A. C. outlet. Remember M,O.H,0. is completely legal, patented and FCC. approved,

(We provide you with a Registration Sticker too.) . -,. ihOft f%C

Kit i^du.uO Complete

(For rotary dial add S1 50 per phone)

Assembled and Tested $37.50

POWER SUPPLY
TRIPLE OUTPUT
25 Volts @ ISA

5 Volts @ .8A

15 Volts @ 1.25A

Isolated independent
outputs

Positive or negative
operation

Constant Voftage Regu-
lation

25 Volt line adjustable
with 10 turn pot from
23,5 V to 28 Volts. 120
Volt - 60 Hz input Fused ■
H-3^^" W=5V' D=4''

Fixed Inductors

.39uh-6/1<**> 12.5 uh -8/1°°
500 uh- Hash Filter

(S 2 Amps ^ 4/1 °°

Molded Choke

l3uh-8/r^50mh^6/1^^
1.2 mh 8/1"***

Precision Hybrid
Oscillator Module

Has both 1 MHZ and 2 MHZ
TTL - outputs —Hermeti-
cally sealed —Ultra high
stability over wide temp,
range —originally cost over
$40,00 each — we made a
super purchase from a
major computer manufac-
turer — 5 Volt operation -
fits standard 24 pin socket -
Manufactured by Motorola
oscillator division.

MC6871A

1 a %f*m

iM.

3/20

w/data

Variable
Inductors

30-40 uh
.9uh- 1.2 uh
11uhto20uh /
,25 uh- .35 uh
,85 uh - .95 uh

NEO 2137 by NEC

• Microwave R F. trans-
istor (N.P,N,)

• Micromold Package
#37

• Dual Emitter leads

• FT to 4.5 GHZ

• VCEO 10V-CC 20
MA. HFE 40-20Q

• Gain 10V'20MA'
1GHZ - 14DB Typical

• Very low noise - High
gain 1.5 DB @500
MHZ

• Cleared for high reli-
ability space appli-
cations

COWPARE 1 ^'^

El AJ #18398

NEC #4981 -7E
Microwave - Schottky

barrier diode

HP-Hot Carrier diodes

5082-2835

• It

*^ or 6/5°°

REGULATORS

LM309K *S V. 1.5 amp TO-3 1-00

LM120K -5v. V5 ampTO-3 1.00

7805 ^5 V. 1 ump TO220 1.00

7812 +5 V. 1 amp TO220 1.00

7905 -5 V. 1 amp TO220 1.00

7912 ^12 V. 1 amp TO220 1,00

UNIVERSAL

TIMER KIT

* Adjustable from 1 sec
lo 1 hr.

* Control up to 1 amp
*Tum Things On Or Otr
Kit includes ail parts
necessary to buiid this
exciting kit Uses: Children's
TV programs - Darkroom
exposures - Amateur 10 mm
ID er - Egg Timer - Inter-
mittent Windshield Wiper,
Absolutely endless uses.
Complete kit including
power supply, pc board
DPDT relay, and all parts to
make timer operational

$895

ORDER YOUR

TERNS

AU I |^4;f|fe if* pif h^inff (hiti% vtii^t IS i44 7S hioJiPf 1^4

idd 5^ Uf F&i^i^fl gr^rt |Cin»d9 lOx] t4ik 10^ PAH

• VISA • MASTERCARD - AMERICAN EXPRESS *

1982 CATALOG TODAY!

Digital Research: Parts

P.O. Box 401247 • Gsriand. Tm« 75040

(114) 271-2461

73 Magazine • February, 19S2 175

M SP€€I ALISTS • CUSHC Anf T • DRRKC - HUM HCV * HUSTUR • HV-GMN • ICOM * KflNTAONICS

SONY
ICF2001

OUR BEST-SELLINQ MULTI-BAND!

D ^*

DIGITAL
DIRECT ACCESS
SHORT WAVE RECEIVER

• tSOKHz -30 MHz + FM BROADCAST

• PLL SYNTHESIZED WITH SCANNING & MEMORY

• AC ADAPTOR tNCLUDED

• 1 YEAR SONY USA FACTORY LIMITED
WARRANTY

• AM/CW/SSB

• SURPRISINGLY AFFORDABLE

CALL AND ORDER YOURS TODAY

Kirog^tfji)

AS LOW AS

$n^50

• Wuiti-bano Muiti-trn^ucncy

• liUjtflnum etticie^Y — no tfips, toMfft^ cods m stuM

• Ftiiy iSscinUed in<3 p^^-lumtf — no measuring, no cuthng

• M i^cattitr mwi — 1 KW Ml. 3 5 KW £W or PEP SS3

• Proven perlcKmjnrt — m&re rt»an lO.OOO have Sef n dctivtfn)
« Permit use of IM lull ca[»bilities of lodiay s ^band <cvrs

« Ont leedline lof operaiion on all Eiaixts.

Add $5.00

for shipping

(Cont I U.S.A.}

Eawsfb'^iper

SHORT WAVE BROADCAST
RECEIVING ANTEHHA

* AUTOMATIC iANDSWItCHINQI

&0'40HD/A 80/40 Mtr bands (69). . . . 9t*00
75/40 HO/A 75/40 Mtf bands (66). . . . 94,50
75-10HD/A 75/40/20/1 5A10 Mtr (66). . 126.95
80^1 OHD/A 80/40/20/1 5/1 0 Mtr (69), . 1 32.00

AMECO ALLBAND PREAMP!

Our Most Popular Preamplifier

MODEL PLF2

$5295

plus $3.00 shipping

piit« f 3.00

■hippiinf]

(Conn U.5J

♦ COMPLETELY |wrATHEftPn0OF!

• coMPLrre, no assembly neeoeoi

• eO. 4S. 4K 31> 2S, tf, It. 13 ft ITM BAND$! ^«

Au the worlds *ftpiiiiia»i bnuacati isvids an
r^^ri. Aiih thff Ejwidiopptf Alt Bartd *fl|«Ai>A.
4t^d<Yq3u»il|r hPied Iraprs itioi* lh* EAvHdrOMtftf

a iJiifflrBiir iriieniai^Dnai tiro«acd»t t*na Ais^
i7> cowrt It and 60V tiAndsAX wall U% tOO ruDl, 3^^

Dititi tMiancM teecntna- pro^idM m ft«Kt ma^h to ii^

S&sernbleti amU re»dy tO *Wlf#ll WItti » ft of <S0 ^j;
tb lest ny+on rOptt Ov«tlll l^fltfltn 4l ItJ' Wtt
i 14; copper cLad sleiH BindSMfifchiivg Autocrutic
lifipsdArice to rcvr SO Tb ohmt t4)iMV«d

*■ <^^'^r^^»^<'«'*^"'

TRANSCOM

PROGRAMMABLE SUB AUDIBLE TONE
ENCODER FOR ICOM HANDHELDS.

$2Q95

MODEL PLF>2..Jmproves weak signals as trmch
as image and spurious rejection of most receivers.
Direct switching lo rec, or preamp. Includes pwr.

supp. 1 1 7 VAC wired & tested, , , , SS2.dS

MODEL PLF-2E...240 VAC 5060 Hz operation. . „ .

K'-f-taBAap«,|p«4«. ■■4.1. •>»*•!■«»■■** «-'-«-' « »«>'■■- m. »■ m Mi. A -m ^PWV «VV

MODEL PT*2...Fof iransceiver use. Continyoysly
tunable iJ^om & to 160 meters. Features dtial-gale
FET Ifanststof ampUfier for improved receiver sen*
sitivrty and low noise figure. Requires no
transceiver modifications and can handle up lo
250W transceiver 0ulpuMt7 VAC 60Hz. . , .$79.95
MODEL PT-2E...240 VAC 5060 Hz opera1ion$B4.95

ICOM WE'VE SOLD FM GEAR FOR 14 YEARS

& IN OUR OPfNfON ICOM tS..,
"SIMPLY THE BEST"

Plus SZhOO

shipping and

Itnndling

•ONLY 1.1" X 55" X .2"

• PRESET OUTPUT LEVEL FOR IC2A

• LOW TONE DISTORTION LESS THAN 1%
THD

• TONE STABILITY ± .2% Hz FROM -20G
TO +70C

• 1 YEAR LIMITED FACTORY WARRANTY

• 5VDC POWERED

I . it

IC2A, IC2AT

OUR MOST
POPULAR HAND
HELD & THE BEST
VALUE AVAILABLE

• COMPACT

• QUAUTY CONSTRUCTION

• VERSATILE

• AFFQFIDABLE

• WIDE RANGE OF ACCES-
SORIES AVAILABLE

IC3AT (220 MHz)
IC4AT (440 MHz)

IC25A

A LITTLE PACKAGE WITH A
LOT OF BIG FEATURES...

• 26W OUTPUT • MEMORIES

* ENCODING MIC • SCANNING

CALL FOR PRICE & AVAILABILITY

^ _^ rtnrifci-n ^^^^ ^R WRtTE. MASTER CARD, VISA, MONEY ORDERS, PERSONAL CHECKS TAKE 3 WEEKS

3 TO ORDERl to clear, accepted, international orders welcome, please request pro forma

m INVOICE,

HOURS:

MON. THRU WED. 9:30-6:00, THURS-FRI. 9:30-8:00. SAT 9:30-3:00

stop by and visit v\/hen IN the chicagoland areaii

5
8

176 TBMagaime * February, 1982

SS££^Ut» Clock Modules

12V DC

AUTOMOTIVE/

iNSTRUMEfVT

CLOCK

API" LIGATIONS

• A1t*'-rfitri!*i #Liba/
HV ffoeiii

• .Airc#»l!T-miiFiiHi elki.

• Portibl^/l^aUiry
povnetati init^umnti,,

F«gtiir«i:Brl^tit 0^3' cif»n diipliv. Internal cryttMl ll^mir-
bl IB , t O.B ABE . /d»v Accu r,. Au ta. d I ipl4iv brigh t ntf^t can Ual
4oi|]ic, Qitpld^ CGlar fHi&rablt t^d blii^e, blue^greBn, graon^i

valloM. C^nvptete-juil add iWltC^n snd^ Iftnt.

MA 1003 Module [iw"LKi,ys>'HK.w"pj . $16,95

CLOCK MODULES

.7" PiwS Pigji^F LEO Cieck Moduli*
?" Gk3. LED Alarm Ci^HhrthwrmtMtrit^m

.3" Had Digiut LEO Cloch/Ttimer

,3*' RhI Digital LED CMlch: A XfOrmV
ff - T^cd D>A»T«i LED C^oek

CSA J" Dil4t4J LCD CIdcJH

.7^' Graan Dlfiui LED Cicch

TTlAP4SF0Fl||£ltS
Jl fornitnr ^Or M A T 0^ J. I DA3 & «)3e Mw*>t
)Cf4^i>n«f for MAIC^ Cfoch Moctuin
Xtormar ror MAIOTQ Clock *^odu«

itAlOS^

MAtOSQ

KAAioai

uAiooa

MAtQIQ

MAiOja

MA104:i

IBJ^JO

IM P23

102-^2*

MICROPROCESSOR COMPONENTS

SUPPORT a LV ICES

C^J

DATA ACQUtSlTlDN iCCi^TliiU£DJ'-
o^caiiLciM ja^aitVAi

ylNi«Di

liO C^MWH

JUt^ik«niton4u« Cmwwri. CM«n4Af

at^fl iftM^rlt T|m#i

Prot. hrMtnaral l/tl (PS^I)
Profl QWkM CgnFPDt

PFvg. cm ConlrQUDi
Fran KivtiiWU'/PiilPlilV
fiyitam th'ilikti £ii5nan1
I^B't ai D^^^tlltnAl RtcilvBF
H-Sil ■H'Ott*t1t<ph*| R«tivu
HNl lai Cl>r»tlNkni« NKrlrfe<!
eUMMM M^ftm* hrijriur^ Dp i

6a»/nD0 SUPPORT DE¥IC££

«HtA

■awiDfAC:

~ftAir$-

!NCWI

Suf? Power Voof Etectronics!
SOLAR CELL PANEL KIT

FaplMiat:

« Output: 10VDC, to ^mmtk irt Birlet

^VDC. ID 2D0mA In FaniJItl

- t'dnti mif Im •■fl'lljr cann«cl«d fof
t>afKfti: »r PirillMl oul

* Ovarii aquua Inehas al ■«ih«'e*4l

■■■■«

« VatlMga llfw lap V OrSV MHVrianu
< PfOTtalan Iv etwrgln^ HMIWfta*
* OvaialJ pan^ aka:

teMv

JE30S,

$3995

EPROM Erasing Lamp

Mm mm

- Eram J^Oi, 2716. 1702 A. &?03a 52040, ate.

> £faHt up 19 4 chipi wrihFRi 2<0 rnmutRL

" MamiBtni pan^itafit mftp^mtm ifirtan^ of a<w »ik^.

" Spacial eoncfuctnifcHm1tnaraliTrin<tesxtvfkfa«jilif-«ffi.

• Audi tn Bfvtv lock to pfaawfl. UV mpopirw.

* Compact - only J-^iV m f-J/t^ m T*
^ Camptvta mnh hiildinq if tv tv 4 efi^Ki.
inriS^IIEL RaptocfTwnt QaW* f tftJl6

Diirljl UQOEli

MlCftOPf^OCESSOR CHIPS'

^K^ I'lfri) CPU [WnMei^'i] i'MMf (

CDJ=>iKl CPU

I BMJSftl AOC CaU-* an ll k* iC em. Tump, a 'Mil

Will Crtn^mli

« llllK
UM>] tli4K
ifNHJ S-tMHC
»Ari4 SiCIIIC
iU'< built, MOB
tOMic* If illc Writ
)I|IP4 aiHtlC 4|Cn| Law P^rtnir

Uallc »»Hk

tlUK JfiA^f Maw f^mmr

»
I Ji

J.fl
4K

i y.

iNBKiiHN«
irvsayaN-i

ir«&K»N

hiPL^i^V^rctcK 4Uhc Byi«t Mtntpcv^

CPU-lfl- Cmtt l-Bbl 1 UlDV7«i « AWJ
ClHJ (Mi ayui flfcM-)
cih;-* ivtvi n*ui

Cnj #/a«Ui. M'Cdt inimiThrmlMT

CPU

uau-HkHlo

-SHJFT REGISTEHS

O^P«lip-it«J
Drt

IL«I

H.ll
H.ll
II.K
IL.II

)»
iM

a rt

uatH

aiitiiiKatitnda
RtWt Cnmtm*

bst-aii Dv')ti*'«

Dut'i IM Qil StMlW
□I'll JH-IM ttflllC
□ utOW-lJI l[«ttt
^Kidtfrtll ataElt
FITQ IQutI »i

-DATA ACQUfSITlON —

Uhl¥«'UI 4(1 '<• FN) I' a-51»
f «gc.h ToM« i.o>T Bl'^e F|it|ir«
TM«h T«nt i^*^ Aanfl FtiUr
«wa«^«aiTiOp Itnv
Cftna^'t C tV rtflfl

«FCT KIWI lOa Amp

JLIt

M*
LS
Ul
Ml
IJI
Ma
iM

t.n

UVS-11E

$79

JS4K

JOYSTICKS

JS ICWK lOaK Linwt Taper P«a . .
JVC -40 40 K iZ) V^rtMo C9<T(re^lar il^

ALLIGATOR CLIP TEST LEADS

HlMn<!ulr baids. 'CdIof codaO- f nivfnlafl al Nq Blar tllp on luh lod 1 Q'''
IMf.Tia9 iach b«HC»i. rfl*]_ bJus, whilw ur^d yelnow.

#ALCP 00 per pack) $2.95/pkg.

^'^ J E215 Adjustable

Dual Power Supply

GtrvinI 0«CfP|}tiOfi= Th| JE2!$ ti » Duel P««v«f^
Sunfiiy until tadgpewtwl MljLiitibtt poaitiHtvncf ncp
i»vt twtpvn wllj|>A. A nptnti ntjinEiiiiiit lor etch
Qt thi Euf^pliH |>fdvid4sih« utftf unlimiTTli f|lpl^tJortf
For IC Cvrrvfit voltifi nqurtintntL Tin nipfily ctn
llio IM u»i^ a$ • g«nvil tlF-pUT^OK vircttiit poiiivr

lUpplVn FEATURES

■ Adit/ttaD^arvBuiata^pCwaf tupplktt^
PQf. ani;] mafli I.^VDC t«i 19VDC

• Pewa' Ouipui taich fupplvl
hVOC 9 SOOmA, iavcCl» 7S<lmA,
12VDCi»aC0rTiA. and
ISVDCO t7BmA

•Two. atirmlnil idj. IC rii3i.tl itort
With Thafftiil ovarioed prstactlon.

• H«Bifink i-tff^litor ce?oliiinu

• LiO "or\" Indlfiatnr

• Pi^Jn3*cl doard Conti'uCTlan

• 13DVAC 4nt3iit

• Sl««: 3 i/J-w » 6 t/ie "L f 3"'H

JEZUMj. Ou«l Poww Supply Kil (aiUitnwnJ . . SZ4.iS

t.ft
11^11
]*«

■4 aWW IBiii ■£!

4 ll*!*

rROws/EPf^cMyi$-

4.H

ttm

imint«l ti
7^4

JIM i/u t^«tu» iTQotiii m

liK tpaoM inv^ **v, ■•■[IV ( *.!•

liK CPHQiVI 4li[>tl« +IVt LH

UK EPNOM L^.n

|4^ f P^'Hd'r^ LiAOni] 'laingii' -^$v| T,ff

MK Ei* li UM I HI tlLH I HNt«J Wj jf ,|(|

JOHPnQM J4,tt

^^I'PKCiM iOHir CQlElveiti'] LH

4(M arpfKiiJ PMGM It.H

Ihl T ^ I ^IJU BiDWkt PJ40M ILlI

m^ *«<>** 1*.

ftOM*t

IIIS311T4S11B)

ii^HCOaUHr
iUI4ia

Cm^Wiai Qai^^iqr I1JPW cawi

#4W0S ftEAD 014 Ly IWEIW^mES —
MlCROPtlOCf^On MANUALS —
ITfCrAl FUNCTIDN ■

E9U1 IWH CMK^ O'livr aJM-fl
:N DiiV wot C»<A Dr;4Br |iVtZ|

iJ^lilTlhrl Fjd^^v Oi*( CtmtTEi'iai'

INSatlh Caniriimf|i<l1l«n CHIII

MMmfTK V^tiiPai'MiluiF A«iP tin* CiDCH

COPaSN hUlEfaeafiUulltr wPtn H-QJflM AaM

iHD Dli^lCI Ltb brivi
CaPASMh hlicroccinlrvNtr w^Pi H-'DISH HAM

t pirtui L.l:4^ Uni'rt W/Fw Bulii Ini.
CDPilQM Ukitl VAC r iu«r. Dplvt:r (jfrpin pHi

1«

urn

(ja

«v.^n

'TELEPKOME/KEVBQARD CHIPS'

€ai^ Q*vi.» n^umttot

I Cauaif IP ti*T«t

tw;»iiillH^yir|

i»

ji.li
■ ti

ILH

t,H

1.41
1 J.S

ll n

^ ft

BQOK^

UtoaanBtTTLLaalaG

&yr

tif mvi^

^iTtvfvll Data icriA 1 1474 epg««J tS K

mWDD PP»Ht Campoamil E}«U Cqtad^B ttlUPD

FvK !^1^ «na>l4 ^ Inlal'i prciducti tm^. ittWMMy 4<lrvk»B,
miemprnr . ppnqhwnli ft iKduGr /mit iIHMliiCia 1 t.3BM MBMt

10 lntBl43«rLpitBPfl10n>li|n Hpndtfdak .. ^....0.60

Full dsLB 9imBL'». niilt<i mdeib f pr InHl p«rlphar«t dautci

CDrnpnuDi^la 1044 (Ui(|Ak1

-i^

AC and DC Wall TransfDrmers

WIUi UninvnaJ t^Mg *nd
»V laltary trip

PotafHyi HiaMDB i^t^ W-fQat

■lie bva. ■ttapiB' ta Bii^i -^ a^ ■
mcii una i^i^i adipW' tobanvy

AC ao
ac 500

ACtOCB

ovism
Dceoo

unawt

117V40H2
tt7V<HH£
ItlVflOHJ

lan'flOHt
ityvmoitt

izvAO«o£aiyi
mACt 7.

■viLITVDC aODfiWI

WDCroOniA

WDCSOKiiA

1335

I3S
t3 9E

CONNECTORS

PBSSP
P2041BU2

uaee,aj

UG«9/U

■JOIT^/U

SOZ39

pLzse
PLzsa

1JG260AJ
UGtG94AJ

D-$ubminiBtuF« Plug

D Subm^nLvtuirv Sc^kaf .. .
SE^av^LiM^ Hdwr, (2) OQ^&S/P
OQvut tor DB25P/S .......

P.C Edfp J.22/44 Prill

Sf4C Ptufl . _ . _

aNC J^icfc . . . . -

UHF Adamar .... . . .

UHF Panai Racfi. ^ , i. * . . . .

UHF Afl4rtar .....

UHF Phf^ .... ........

BNC flufl ....,...•<..

QNC Bu^khavd n*cp-

. %23B

. «1.75
. $2.95
. t1.79
. S3, 79
. t .49
. S1.29
t1.&0

. tt.to

. ST. 79

S1-2S

2«t-1t

EECO floeliar DIP Swiich — "Mui^D^ m" 2«0 S«dM

THt HOST UHlQUt CKP IWITCH AVAOAAiCl

^vfrflr lanatM yap^H isaaamiaB* 7-frf^fw Man a"

Cat^yariiMn

hn'fy

14411^3

1S14

A!ii:it
i:;Hn;n

I pin

B pin

14{iIb

.71
.»

.tfl

.'fli
.01

It/ |W

MDD-E

PQ/ 7.1B

fUd-?

PC/ i.yit

F4n-i

Pfl./ I.Bfl

un-i

10/ ■.»

?1H-111

**ni;

Itl

C'Cntigyritliqnt

lS4(S^^~
1»4UT

tZUHTHV

hdm

14 iM
tipta

15 pin
IS pin
ID pJF

1.«

lis

1.»
1.»
I.U

PDnflit

10/11 n

iDMjia

JE608 PROGRAMMER

17D4^2T0a EPROM PROGRAMWER

• To mrwmw^ EPfMMH XPVi

JE610 ASCII

Encoded Keyboard Kit

arwilttlM«4 KUTi ^a hajaaar^amr^A^ Aiawi Mapaiil _
hKflllen. Stama'aKHM tPHOH PfaQmniaat CMUdfttM at; a

H«M

iitoiaii1PM|yp' Hid da«n) al 4«tip

■I Kartaafd HHnWr. PwrBm-

pa aatHnUy. Tlw ThiI' Saeul la

nwf Soflpd ■•Dvnbtv w^ 4 p«ww lupfrftaw amd t LiVTiHt Bocfcal PwhI ■<

ttm totem Invarthn^ tiipa Poii«r r»qu1rafn«nrt liUVAC, W-Mi. 8W CompiN;! i3««|i.rop *nek»urv CAtor^
BOOfdlpu'hid dHlBnaTi ciia *I1!) Hqtil tin paniti aiiiS nt^ldad §nti plaeta In moeha brtm-i^. SJia: 3'.i"H i ir'W
t i^"T}. WiPghl:> Ibt

Tlia JEGCB E>*F10IVI PruijrirTHTMr a a complaUlv MlP'SPnCalntd iMill'wtHOi itrndapa^anf. grcQinpi^rgprTtriiJ lUidTKiuirH no
tddlilQrMi it^^iafni far \n atiat»\tf\r\a Th« 'E^FlOM cm'i b* prpf^mrnai riium mi NindHjImil Kaybotfrl nt ^^an a pm

pr&if^mmK] EPBpM TPia ^^^0$ pTogrrmmir cin flmmJNla h prugrimniKl [;4*B0M by Ifia ul| pi in Iptimil RAM filfCkilll
Tm*M |IJ(MVlh*'UM^ IVL7H1 nrpnitfl I Oi-O'Ki'ft'n IdF I IVIHIii p^f te<prOilT«iri|iilri^aeN|l Any chpngai Inlha pMqrtmctn
bM-aotflmd diradl^ into \Jt* maniDrv ciiz ulta wrfi tliv HpiMf^lrnfl Kavt>oird ip that liwHtlnQQiv vnEiri prpgrpm will npi U*

niiiinry. TNi JftQI frBvafirw Eonuma • Fregiammkr ! Kc«rd w.'S iCTt h Induih* .^bwar ii^laa et< BV
4-»/. 4 13VtM tlfyr TtwHaBKiai3ni^lCrrtMar«4rfdLEQ>'TwlS«fa|tFli«b«Mi4ii*H0a*aMaaHn^li*«-^:ttln

jE§OflK Kit ,,..--.- .

J E6€8 A A«Mmbl9d and TertMJ

^*^*********

I399.es
$499.fS

JESOa-IOK ADAPTER BOARD

JfZOQHafrP^W ffS^PP^v Kiti^VOC. 1 ampi tt4.fiS

iE30SA4lp^Btil.!foJE200HS.-»& r12V S1Z,»S
JE2?0V*f.Pwr Sptv Kpl.S^IBVOC.toT&a'Tip fifths

»iaaai4Mii«leriw

JEQOa^UpgricIt
jEAOSA-ieKMad

iSwidaaaaniblMf JE9KT&1«etQTvf(>radipi«rifm«litf6on tSff.tS

of ma JEaOO-^filC Adapter Board Kit J

Aaiflrntjicd J EBOt vir/^ Adapttr | JESCB-I SK] inttallad 15S9 J9

S 10.00 Min. Qt d*f - U.S- Fuhda Onfv
Calif. RaiJdanTi Add €% S^le^ TaH
Pasla^a-Add 5% ptui91.&E> Imurinca

Spac Shaali - 2&4

Sand BB* Pnilafl* lor ynur

FREE 1982 JAMECO CATALOG

^it^N

\^?

^ck;^.

J^V

o<^'

ameco

ELECTRONICS

PHDNC

ORDERS

WELCOME

(415) ssz-sag?

2/Ul

MAiL ORDER ELECfROSfCS - hORlDHWE

13SS SHOREWAY ROAD. BELMONT, CA 94002

PRICES SUBJECT TO CHANGE

.^30

Tna JEEIO ASCII Kayboard Kit can ba Inia'faoad tnio

rrvaii any cdmpUiar tyttam. Th* kit roiTiif Eomplata
lyvitN an indutirlal D'lda kayhaard iw^tfih aiaamblv
(fi2-K«v*L Id. IOC kali, cannactar, alactronlo compo-
nanti Bod a dDublalldad DfifiTeiJ ui/lrlrijj bDtFct The
kavbo-ard aiaat^rtjlv raquirt* ♦^V ^5* l&OmiA and — ISV
9 TO rr^A tar oparrlilon. Faatur«: SO kavt ^hai^ttt liha
l^e ehafactan. upp*r amJ \tmW eaw ASCpJ lal FuHv
Oulfi-rwd. TvMD uaaF'dalina kava prpvidad Tar custDm
apDl teat jQ n«. Capa lacN for up0ar-caaa-4 1^ iv alpha Sftnc-
T»T» ytiJiiai a 23 76 laO cinh «ncoc*w^ rai#d-DnP¥ iilift»fV
<chi6. QuiDuu diracTlv eafTipwl3)la witti TTLJOTL or
MOS Tf^sK affava Eatv ImlarfacJoi Mlth a 19 pin diD or

JEglO/DTE-AK ifiSJ^'^SSSi .. $124.&5

iccin I/*:* « ««¥ Kaytoard.Pcaoa^a. * tq qjt
JEiDIUnlL .4 CQniiP^nanEf |oo casai . . . .^ /3*93

K62 &2-Kay Kayaoai'd (KaybDAtO an>y> . ^ -S 34.95

DTE-AK (cat* only - laii"MiclI"Wietai'*ojS 49.95

JE600
Hexadecimal Encoder Kit

FULL f^lT
LATCHED OUTPUT
19 KEY KEYBOARD

trm JE€00 Enco4«r KavbO^fd KttprDwidai t#D
hmMmawcimai dlfJta p'Oducad from taquannal KtY arnr^a^i
ia a1{f3n/v difact prbfiramfnlnB for S bri rn tcrppf qcaiap f
or B'bfl ma^'^Hirv ci'CMlIt- Thr*a addaionaP h«vi ara pra-
vtdad for ijatr oparaltani wltti ona lucv^ng a biilabla
OulpuT vvalPabla- T^^a ouTpuTt ara laTcrvao anU manitorsd
with fl LEO I'aadOuti. Alio intPui^ltdivaiKay amry itreba.
Fva^Mfiiiii: puPl fl-bit Patch^ output fgr mlcroproceiiar
Uia. TNraa uiar-dlt4na kav> WhTfi on* b-llri(r OJfTabia
Qpfli'ltlnin. Dabaunca cIrcuJt prOvldad (or all 19 kayi.
i LEO rpacl<»uti to varltv antrJan. Eaiv Intarfaalnp iwlih
iTand«fct Ifi pJfi IC coorwclPr, Dihlv *BVDC rv^yirad
t^T {>ppr«tion Stra a^-l'H p 8W"VV ji Sii'O

JESQO/DTE^HK ji p<cui?td a&&»a) $99.95

Jt^QO Ktt PC eo«r4 «• Cmoritli. [fio caM) - $99 'TD
K19 l^tivf KarDOard (Kay^Haarfl oniyl , . , SI 4,95

OTE-HK icHtontf 3i7''Hsd>»'-iw^i*"D3 S44.95j

TRS-80
16K Conversion Kit

Expand your 4K TR& BO Syitepi to 16K.
Kkt CPITii( comptata wilh ;

* B aa. IViMe200 (UPD4l6/41ie! 10K Dyn. Ram (*NSl

♦ DoeumtntJitlon ivt Copivarakin

TRS-16K2 M&ONS ............... S29.95

TWS'16K3 *20t)NS ........,,,*,.. $24.95

TRS-16K4 *250NS _,..,,..,. Sl9 9b

f,/VAM^ JE2I3 - Naoativa 12VDC Adaptar Boird Kct
ZNEWI? fof JE610 ASCII KEVBOARO KIT

Tv^vJ^^ Pro,wlaiJ-iSVDCtrOrTTiFlCOm|iirjS.VOC $9.95

'Se# jL^sf □/ Aiivefftsets on p^ge J t4

JSMagazme • FebruaryJ982 177

q)Em£R

Internet Archive Audio

Featured

Top

Images

Featured

Top

Software

Featured

Top

Books

Featured

Top

Video

Featured

Top

Mobile Apps

Browser Extensions

Archive-It Subscription

Save Page Now

Full text of "73 Magazine (February 1982)"

See other formats