Full text of "73 Magazine (November 1984)"

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International Edition

November 1984 issue #289
$2.50 USA / $3.00 Canada

Amateur Radio's

Technical Journal

A CWC/I Publication

CoCo
Slow Scan

Page 10

One-Chip
Audio Filter

Page 34

Secret
Soviet
Signals

Page 53

74470

65946

1 f

CoCo SSTV— 10

73 QRT? QRX\

Page 8

Color Computer SSTV: Part I

\1 Turn your CoCo into a complete SSTV
terminal f How? First, build this high-
reso I u tion d is p I ay s ys te m .

K6AEP.WBBDQT

Wrap Up TV I

Can you endure another evening with-
out transmitting? Use this simple cure
to choke out television interference for
ever , KR7L

But I Know How To Solder!

Anyone can dribble hot metaJ over a joint,
but it takes an artist to really solder Are you
a Picasso or a pig? , . WD4S

Free-Form Filter Design

[\~^ Build the ultimate audio filter: high-
l*--J passr low-pass, bandpass, notch, vari-
able Q and cutoff frequency, all in a single
circuit Circuit? Sorryr that's single chipl

. . KA4QVK

Vour Own

Optoelectronic Anemometer

[\1 Light control and car- top calibration
make this project cheap to build, easy
to align, and extraordinarily accurate

K3VDB

Rampant RTTY

Create the ultimate mailbox ! K0WVN
describes a system that operates from
45 to 1200 baud with dual shifts — automat-
ically . . . K0WVN

Decode Soviet Space Messages

\\A As you read this, mysterious signals are
L*u being beamed into your shack. What
do they mean? Where are they coming
from? Use WD0BCJ's satellite-telemetry
reading program to uncover the facts,

WD0BCI 53

The End of the Line

What's the point in sending power up the
coax \i it never reaches the antenna? These
tips on connector installation and care will
help maximize your station's signal.
, .WB5LBI 56

A Useful Present You Can Build

fy] How about a high-tech holiday gift?

UJ WB4YOD/PWBZAF 58

Ham Over Fist

a Here's a VIC-20 CW program with a
twist: Its real-time display lets you
watch your dits and'dahs dance across the
screen But be forewarned — you may not
iike what you seel WD8BHH

Homemade Defroster Shutoff

This simple gadget has nothing to do

Dr. DX— 76

Never Say Die— 4
QRX-8

Barter N' Buy— 70
Ham Help— 70t 75
RTTY Loop— 71
Sateilites-72
Special Events— 73
Circuits— 75
New Products— 76
Review — 77

with amateur radio, but it's a neat little
project anyway KB2WM 68

Awards— 81
Fun!— 82
Contests— 83
DX— 85
Utters— 86
Reader Service— 88
73 international— 90
Dealer

Directory— 110
Propagation— 110

2 Meter, 220 or 440 MHz

IC4AT

Ml) MH/

• 0

IC-3AT

22()MHz

I02AT

2 meter

Leather Case

Available with o
without cut out
for Touch I one4

Battery
Pack

■

Nominal
Transceiver 1
Power (watts)]

BP2

BP3
BP5

BP8

1.0

1.5 I

2.3

IC-HM9

IODC1

DC Regulator

IOBP3t
Battery Pack

IOBP2 wmmr 8.4 VDC 250 mAH
Battery Pack i 5 hr, charge
7.2VDC425mAH
1 .5 hr charge

IC-BP4 *
Battery Case

BP5«
Ifcittery Pacfc

10,8 VD^T25mAH
1 5 hr charge

IOBC35
Battery Chrfrger

! " jittery

Dctcrrnjjfts
Charge

12 VDC in/9 .6 out
( comes with DC
cord— will not get
power from BC30)

* Requires BC-3 * Charger

tmil tlwrgefmm BCX*. BC-25L\ stet CP1 or
i 2 I IX Ditict i internal!} ' regulated)

ft Accept 6 AA size batteries - Alkaline or SiCd
( IM* rtat attempt tr> charge Alkaline batteries}

IC-BC25U

AC Wall Charger

117 VAC in/
1 2 VDC out

IOML1 12 VDC
44 MHz Booster

W out/ 12 VDC
omes with 5 fcet
x, BNC to PL-259 )

IOCP1

Cigarette Lighter
Cord w/Ftise

(charges BP3/powers DC1 )

ICOM's reliable Jieid proven,
handheld* have been the
most popular handheld on
the market. Here's a lew
reasons why:

The Transceiver*. ThelC-2AT

features full coverage of the 2
meter ham band. TfaelCXSAT
covers 220 fo 22499 MHz. and

the IC-4AT has 440 to 449.995
MHz Each radio is only 2 6<nx
1.4inx6.5ininsize. Excellent
audio quality is provided by a
quality speaker and an
electret condenser
microphone, All have 15
watt output and battery
saving 0. 15 watt law power.
Touch Tone " pad is

included (on T models).

Standard Equipment. Each
transceiver comes complete
— ready to use — with BP3
rechargeable battery, AC
wall charger, flexible
antenna, earphone, wrist
strap, and belt clip.., all
standard.

NEW Accessories

IC-BP8 fong-life BOOmAH Battery Pack (rechargeable with
BC-35). BC-16U Wail Charger (BP8 only), HS-10 Headset and
HS-10SBPTTSwitchbox.

The System. Accessories for
the handheld series are
interchangeable between
transceivers. Slide in
removable battery packs
allow quick changing of
batteries. Batteries may be
charged when removed from
the transceiver.

ICOM

^2TA

Hie V&brld System

'COM America Inc. 21 12-1 16th Ave NE BeHevue, WA 96004 / 3331 Towerwood Drive, Suite 307, Dallas. TX 75234

All tfafed spacticafiora are approximate and 5uo*ect tochenge wrtftaut notice Of obliaaTion. All VZOM rodos signrfjcantty exceed FCC regulations finding spofous emissions W784

• 7r

«:■;■:■:>-> ■ —- ■ ' ■

*Z^*

U£J* (5:*

■ : ■?,,.,* i'r.i ■ ■ 3"

P Jj 5

TW-4000A

TM-201
TM-401

X3VS

"U.„ 4_^ !

TR-7950

KENWOOD

my our

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iff*

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TH-21AT/ TH-21A TR-2600A
TH-41AT TH-41A

TM-211A/

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R-600, R-1000, R-2000

BIRD

MODEL 43 AND
ELEMENTS

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FOR

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FT-757GX V

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EXCELLENT
FOR OSCAR

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FT-708R

CALL FOR
LOW PRICES ON ALL YAESU ITEMS

NEW!
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AMPLIFIER SALE

B-3016 SALE $199.95
B-1016 SALE $249.95
B-108 SALE $159.95
B-23A SALE $ 79.95
D-1010 SALE $269.95

R-71A GENERAL
COVERAGE RECEIVER

ICOM

HAND-HELDS

ALL ACCESSORIES
IN STOCK

_. tW m T" **•

* OS*

Superior grade receiver provides gen
era I coverage 100kHz to 30 MHz.

Q *o a a

IC-751 SALE

CALL FOR SALE PRICES

SALE
PRICES

IC-2AT

$219

IC-3AT
$239

IC-4AT
$239

i LTZP-

NEW!

IC-02AT
2NI,HT

CALL FOR

SPECIAL

PRICES

ri-Ex

SALE!

W-51

$899
W-36
$549

LM-470D

$2799

ALLIANCE

ROTOR SALE

HD-73M ^U-110

$99.95 $54.95

KIM

SALE

KT-34A SALE $329
KT-34XA SALE $469
40M-2 SALE $309

CALL FOR LOW, LOW PRICES
SO THRU 1V4M KLM ANTENNAS

PERSONALIZED
SERVICE

\BOB FERRERO. W6RJ
f I president

*■ I JIM RAFFERTY, N6RJ
/ VP. So Catit.Qiv. Anaheim

Managers

GEQRG^WBSOSV Bwtmgamv

GREG.N6PO Oakland

BOB. K7RDH pno^ntu

GLENN. KSNA San Dwgo
AL. K6YRA Wwi Nuys
ana turner aett¥e amateurs

FREE SHIPMENT

UPS SURFACE (Continental U.S.) (MOST ITEMS)

TOLL-FREE PHONE

Hawaiian amateurs are welcome to use our tree phone

800 854-6046

(Gaiit and Arizona customers pte#se phone or visit listed stores)
PHONE HOURS: 9:30AM to 5:30PM PACIFIC TIME.
STORE HOURS: 10 AM to 5:30 PM MonAhrough Sat

TRISTAO SALE

MA-40 SALE $599

40', 2 SECT. TUBULAR TOWER

MA-550 SALE $899

55' 3 SECT. TUBULAR TOWER.

HAM

WOO

OUTLET

ANAHEIM, CA 92801

2620 W. La Raima,

(714} 761-3033, (213) 860-2040,
Between Disneyland & Knotts Berry Farm,

BURLINGAME, CA 94010

999 Howard Ave. ,

(415) 342-5757,

5 miles south on 101 from S.F. Airport.

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East of Highway 17

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San Diego Fwy at Victory Bivd

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Prices, specifications, descriptions subject to change without notice. Caiif. and Arizona residents ptease add sates tax

HUSTLER

DELIVERS

RELIABLE

ALL BAND HF /

PERFORMANCE

Hustler's new 6-BTV six-
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station antenna offers
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with unmatched con-
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offers lO, 15, 20, 30,
40, and 75/SO meter
coverage with ex-
cellent bandwidth
and low VSWR, Its
durable heavy
gauge aluminum
construction with
fiberglass trap
forms and stain-
less steel hard-
ware ensures
long reliability,

Thirty
meter kits
(30MTK)
for 4-BTV
and 5-BTV
are also
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Don't miss our 30 meter excitement

HUSTLER -
STILL THE STANDARD OF PERFORMANCE

3?75 North "B" fiwenue
Kissimmee, Florida 32741

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'31

73. Amateur Radio's Technical Journal is a
member of the CW CotnmLjnic a li online group,
ttie world's largest publisher of compuier-fe-
lated Information. The group publishes 53
computer publications in 24 major countries.
Nine ml I Hon people read one or mofe of the
groups publications each month. Members of
the group include: Argentina's Computerwortdt'
Argentina: Asia's The Asian Computerworl&,
Australia's Computerwortd Australia, Austra
nan Micro Computerwortd, Australian PC Wortd
and Directories: Brazil's DataNews and Micro-
Mundo, China's China Computerwortd, Den
mark's Computerwortd/Danmark arid Micro
Verdent Finland's Afrftra; Frances Le Monde
tntormatigue. Golden (Apple) and OPC jJBM).
Germany's Computerwoche, Mfcrocomputer-
w&IK PC Weft, Software Markt, CW Edition/
Semtn&r, Computer Business and Commo-
dore Magazine: Italy's Computerwortd ft ana,
Japan's Computerwortd Japan and Perso
Corn-World, Mexico's Computerwortd fMenco
and CompuMundo: Netherlands CIV Benelux
and Micro/Info. Norway's Computerwortd
No*ge and MikroOata. Saudi Arabia's Saudi
Compurerworfrf: Spain's Computerwortdt'Es
nana and MtcroSistemas. Sweden's Compvt
erSweden, MtkroDatom. Mm Hemdator and
Svensha PC World', the UK"s Computer Man-
agemant. Computer News and Computet
Business Europe: the US's Computerwortd.
Hot C0C0. tnCidery InfoWortd, MacWoridt Mi-
cro MarHetworid, Microcomputing, PC World,
RUN, 73 and 80 Micro.

J\.

INFO

Manuscripts

Contributions in the lorm of manu-
scripts with drawings and/or photo-
graphs are welcome and will be con-
sidered for possible publication, We
can assume no responsibility for loss
or damage to any material Please en-
close a stamped, seif^addressed enve-
lope with each submission Payment
for the use of any unsolicited material
will be made upon accept a nee, Ail con-
tributions sbouW be directed to the 73
editorial offices. "How to Write for 73"
guidelines are available upon request.
US citizens must Include their social
security number with submitted manu
scripts.

Editorial Offices:

Fine Street

Peterboroufln NH 0346S

Rwne: 603^24^471

Advertising Offices:

Elm Street

Peterborough NN 03458

Phone: 603-924^38

Circulation Offices:

Elm Street

Peterborough Nh Q345B
Phone: 603.934^471

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73 Amateur Radio's Technical Journal
(ISSN 0745080X1 is published .monthly
by OH Gomrrtijivcaitons/FetertKJrou^i
Inc. 80 Pme Street. Peterborough NH
0345a Second cJass postage paid at
Peterborough NH 03456 and at addition-
al mailing offices. Entire contents copy-
right ■: 1W4, CW Communications/
Peterborough, Inc. Ail rights reserved.
No part of this publication may be re-
printed or otherwise reproduced without
written permission from the publisher
Microfilm Edit ion— University Microfilm,
Arm Arbor Ml 48106. Postmaster Send
address changes to 73, Suoscfiptioo
Services, PO Box 831. Farmingdaie NY
1 1737 Nationally distributed by interna
ttanal Circulation Distributors

2 73 Magazine * November, 1984

Stuck with a problem?

Our TE-12P Encoder might be just the solution to pull
you out of a sticky situation. Need a different CTCSS
tone for each channel in a multi-channel Public Safety
System? How about customer access to multiple re-
peater sites on the same channel? Or use It to generate
any of the twelve tones for EMS use. Also, it can be used
to access Amateur repeaters or just as a piece of ver-
satile test equipment. Any of the CTCSS tones may be
accessed with the TE-12PA, any of the audible frequen-
cies with the TE-12PB. Just set a dip switch, no test
equipment is required. As usual, we're a stickler for
1day delivery with a full 1 year warranty,

• Output level flat to within 1,5db over entire range selected.

• Immune to RF.

• Powered by 6*30vdc, unregulated at 8 ma.

• Low impedance, low distortion, adjustable sinewave output,
5v peak-to-peak.

• Instant start-up.

TE-12PA

67.0 XZ

85.4 YA

10351 A

127.3 3 A

156.7 5 A

192.8 7 A

71JXA

S8.5YB

107,218

131,8 36

162.2 5 B

203.5 M1

74.4 WA

91.5ZZ

110.9 2Z

T36.5 4Z

167.96Z

77,0 XB

94.8 Z A

114-8 2A

141.3 4 A

173.6 6A

79.7 SP

97.4 ZB

11S.B2B

14&2 4B

179.9 6B

S2.5 Y2

100,0 1Z

123.0 3Z

151.45Z

186.2 7Z

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

TE-12PB

TESTTONES:

TOUCH-TONES:

BURST TONES:

600

697 1209

1600 1850 2150 2400

1000

770 1336

1650 1900 2200 2450

1500

852 1477

1700 1950 2250 2500

2175

941 1633

1750 2000 2300 2550

2805

1800 2100 2350

• Frequency accuracy, ±1 Hz maximum -40°Cto +85*C

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

$89.95

f15

COMMUNICATIONS SPECIAUSTS

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

SB'

W2NSD/1

NEVER SAY DIE

editorial by Wayne Green

OUR WORST ENEMY

It was back around 1976,
shortly after the Carter revamp-
ing of the Commissioners, when
we hams had our first serious
problem with the FCC. In case
you are new to amateur radio or
are short of memory, here's what
happened.

The first problem facing the
new Commission had to do with
a proposal to eliminate ten-me-
ter tinears. This was in response
to enormous interference prob-

lems from cheap and dirty lirv

ears made for CB use on 11 me-
ters, which were proliferating.
CB was in its heyday and televi-
sion sets everywhere were driv-
ing their owners crazy as CBers
drove by or worked DX from their
home locations with their kilo-
watts*

The FCC had no way of know-
ing that in a few months their ac-
tions would solve the problems
in an unexpected way when they
expanded the sen/ice to 40 chan-

QSL OF THE MONTH

To entef your QSL, mail It \ft an envelope to 73, 80 Pine Street, Peterboroufln NH 03458,
Attn: QSL of ttie Month, Winners receive a one-yeai subscription (or extension) to 73, Entries
not En envelopes cannot be accepted.

4 73 Magazine * November, 1964

nels, almost killing CB entirely.

The situation was severely ag-
gravated when the previous
Commission outlawed 11 -meter
linear amplifiers. This forced the
legitimate manufacturers out of
business and left it open to
underground manufacturers.
Clean-emission standards were
henceforth Ignored and "ham 10-
meter" amplifiers flooded in
from truckstops and from under
CB-dealers* shelves.

The new Carter FCC held a
hearing on whether to outlaw
10-meter tinears entirely. The
main speaker was the ARRL le-
gal counsel, who proceeded to
lecture them like school kids, I
watched in mounting horror as
Booth went on endlessly while
the Commissioners fumed and
then walked out on him. That
day we lost not only that rule-
making, but all sympathy from
the FCC for four years. We were
fortunate that they did not fol-
low up on thefr plan to make a
new personal-radio service with
CB and ham radio combined.

A Fresh Start

The Reagan FCC gave us a
new change in 1981. 1 went down
to Washington and talked with
each of the Commissioners per*
sonally, giving them some back*
ground on the past, present, and
potential future of amateur radio.
They were eager to help our ser-
vice get back into a strong
growth mode so it could again
attract teenagers and thus bring
the country desperately needed
engineers and technicians— as
it had done so well before the
ARRL's incentive-licensing di-
saster of 1963.

Since no-code had been the
breakthrough for growth in Ja-
pan, they were eager to try it out

Continued on page 82

STAFF

EDfTOWPWRUSHER
Wayne Green W2NS0H

EDITORIAL DIRECTOR

CWC/PETEftllOROUGH
J#lf DeTray WB8BTH

EDITORIAL OPERATIONS MANAGER

CWOPETER BO ROUGH

Jack Burnet I

EXECUTIVE/MANAGING EDITOR
Susan Phllbrtck

ASST. MANAGING EDITOR
Sieve Jewel t

TECHN»CALftNTEftNAT*ON*L EDITOR
Perry Donh»m KKZY

EDITORIAL ASSISTANTS
Nancy Noyd

Owtii Schirrtdt

ASSOCIATES

Robert 8*Jie* WS2GFE

John Edwards KI2U

Bill Gosfley KE7C

ChOd Herri* VP2VL

Avsry L Jenkins WBSJLG

Dr. Marc Uevfty WA3AJR

Rill Pasternak WA&ITF

Petof Stark K2GAW

Robert Swirsky AF3M

ADVERTISING
1-800-4414403

SALES MANAGER
Jim Gray W1XU

SALES REPRESENTATIVE
Roaa Kenyan KAiGAV

WEST COAST OFFICE

1060 Mann Road

Merio P*A CA S40Z5

M1S-32&4I70

SALES MANAGER
&org«o S#i«f

SALES REPRESENTATIVES
AJHSOn Wiith
Karon ■Latendre

PRODUCTION DIRECTOR
Nancy Salmon

ASST, PRODUCTION MGRJMFG.
Susan Gross

TYPESETTING MANAGER
Dennis Chrioiensen

FILM PREP
Rotor! M. Vlllorwuva

PHOTOGRAPHY MANAGER

Nalnanlei Hoynts

CREATIVE DIRECTOR
Cnrlttlne Oeetrempes

DESIGN MANAGER

Joyce MijreHa

DESIGNER
Dtine Ritson

VICE PRESIDENTS ENERAL MANAGER
D*t*a WrtfWfca*

VICE PREStDENTJFI NANCE
Roger Murpfty

ASSISTANT GENERAL MANAGER
Malt Smiin KAnEI

ASSISTANT TO VP/FINANCE

DomlnJque Smith

DIRECTOR OF MARKETING AND SALES
Dave Sc hiss I or

DIRECTOR OF ADVERTISING
Stepnen Twomtty

MARKETING MANAGER
Pamela Eaiy

DIRECTOR OF CIRCULATION
Will lam P. Howard

ASST, CIRCULATION MANAGER
Frank $<r

DtRECT AND NEWSSTAND SALES MGR,

1-800343-0728

DIRECTOR OF CREDIT SALES

AND COLLECTIONS

William M Bayer

DIRECTOR OF PUBLIC RELATIONS
James Leonard

^setter m ameteuf maio

TS-711A

notion

all-mode 2 m transceiver

The node

transceiver is the perfect

ise station unit. It feat;.
Kenwood's innovative D.C.S
drcuftry tl »ws your

TS-711A to respond only to
sign nctude . re-

jected digital ■ ode, TM

tern recognizes 100,000
different 5-dig(t codes rnakjnu

ooss*b?e for e&tt\ st
have its own "pn
group call: or 'comm- air
code. Built in dual digital VFO's
provide commercial -grade fre-
quent :btlity through the
use of a TCXO {Temperature
Compensated Crystal Oscil-
lator) The new fluorescent
multi- function display sil

frequency. RiT . VFO A/I
SPLIT ALERT, repeater offset,
li iff i i ode, call sign code,
and memory ■ hannel. 40 multi-
function memories store fre-

i \\j\

quency, mode, repealer offset
a? ne. It has programmable
scan, memory scan, and mode
The Auto-mode function
naticalfy scte the
re ode for the frequency
being used. When a mo
key is depressed, an audible
i innc -5 mode

identification In intern | ai

Morse Cod

TheTS-711A has all-mode
squelch, noise blanker, speech
processor (SSBr FMv IJ shift

R( power control, alert, a

miqut d

■ling that vanes tuning che
actensiics from conventional
VFO feel, to stepping action
when CH.Q switch is depressed.

Optional accessories:

• CD -10 Call Sign D ^y

• n CTCSS I ♦ i -1

e Synth^ ■

Deluxe Desk Mic • !

Desk Mir • IAC-8 I. Mic

• SP J Exl-

• ME A 30 Mobil ml

■ 2J DC C

fi-nu

A R9

^ 0

#«<*■

K I 3

"^■""•■J&i * ■<*•

C^ftfPVWH SQL-§Mf SHIFT

/V6.57C

TS-670 AN-mode
"Quad Bander"

The TS-670 "Quad Bander-
is a unique ail -mode trans-
ceiver that covers the 6 meter
VHF band ar •? 104 15 and

B40 me <F bands FM opera-
n may be added wil le
optional FM-430. Key .feature
in le dual digital VFO's, 80
memory channels, mt-
scan, and programmable band

an. Direct keyboard fre-
quency "ion allows you
enter a frequency to either vi
or to a memory channel usfn
the to button key-pao on "
front panel Tf -color a-
rescenl lube display indicates
frequency to the nearest

tzerunftl thai
oular option available, All

is if shift mode
v semi-br with

row-w r

se n. n and

R.F, attenuator make tneTS -670
Quad Bande text trans-

Optional accessories:

100 Hi (10 Hz mod rid ceiver you should ov

includes LED indicators that

;nai the specific ons in

use The optional GC-1Q gen
eral coverage rec*
allows continue 3 fro

500 to 30 MHz. The V

Flltet • YK-88CN 2 70 I W
Fillet • YK-88A 6 I AM Fill

• PS -430 DC

• KPS-7A DC P ■ Su|

• MC-60A Delu

-Function I

• I VOX u-

Unit. 500
Vc
FM t

ts-7" rs-

Wesi
B8C 500 I Com

••■>..

ized

■■

I rcwl

\**Qli}

hMl

[e«t

biJ

MFJ'S MOST ADVANCED RTTY/ASCII/AMTOR/CW COMPUTER INTERFACE HAS
FM, AM MODES, LED "SCOPE" TUNING ARRAY, RS-232 INTERFACE, VARIABLE
SHIFT TUNING, 170/850 Hz TRANSMIT, TRUE MARK-SPACE DETECTION.

Hit front panel lensitivity control

Normal/ Havana twitch eliminates retunmg while
checking for inverted RTTY, Speaker Jack +250
VDC loop output

£*ar 22Q6 line wave generator gives phase con-
tinuous AFSK tones. Standard 2125 Ha mark and
2295/3975 Hi space. Microphone lines: AFSK out,
AFSK around, PTT out and PTT ground.

FSK Keying tor tramcelveri with FSK Input.

Has sharp 800 Mz CW filter, plus and minus CW
keying and external CW key jack.

Kantronlcs tottware compatible socket.

Exclusive TTL7RS-232 general purpose socket
allows interfacing to nearly any personal com-
puter with most appropriate software. Available
TIL/flS^2 lines: BTTY demod out. CW demod
out {TTL only). CW-ID in, RTTY in, PTT in,
key in All signal lines are buffered and can be in-
verted using an internal DIP switch

Metal cabinet. Brushed aluminum front. 12Vzx
2V*x6 inches, 18 VDC or 110 VAC with optional
AC adapter, MFJ-1312, $9.95,

Plugs between rig and C-64, VIC-20, Apple, TRS-
8GC, Atari, Tl-99 and other personal computers.
Use MFJ. Kantronics. AEA and other RTTY/
ASCM/AMTOR/CW software.

MFJ-1229

$ 1 TO 95

179

Engineering, performance, value and feature*
sets MFJ's most advanced RTTY/ASCtl/AMTOR/
CW computer interlace apart from others.

FM (tirnrtJiKi) mode gives easy, troubte-free oper-
ation Best for general use. ofi-shift copy, drift-
ing signals, and moderate signal and QRM levels.

AM rnon4imiting: mode gives superior per-
formance under weak signal conditions or when
there are strong nearby stations.

Crosshair mark-space LED tuning array simu-
lates scope ellipse for easy, accurate tuning
even under poor signaRo-noise conditions. Mark
and space outputs for true scope tuning.

Transmits on froth 170 Nz and B50 Hi shift.

FREE MFJ RTTY/ASCIt/CW software tor C-64/VIC-20.
Complete package includes MFJ-1229, software on tape,
cables for C-64/VIC-20.

Built-in RS-232 intflrface.no extra cost.

Variable shift tuning tets you copy any shift
between 100 and 1000 Hi and any speed {5-100
WPM RTTY/CW and up to 300 baud ASCII).
Push button for 170 Hz shift

Sharp multi-pole mark and space filters give
true mark-space detection. Ganged pots give space
passband tuning with constant bandwidth. Factory
adjusted trim pots for optimum filter performance.

Multi-pole active filters are used for pre-
limiter. mark, space and post detection filter-
ing Has automatic threshold correction. This
advanced design gives good copy under QRM.
weak signals and selective fading.

7-IN-1 RTTY OPERATING AID

MFJ-1221

$79.95

*4 • *

Indispensable, Improves any RTTY station.

t. Crosshair LED "scope" Tuning Array. Makes
tuning quick and easy with deadon accuracy. Tune
for maximum vertical and horizontal display.

2. Scope Adapter Mark/Space outputs for scope.

3. Shift Indicator. LEDs indicate 170, 425, B50 Hz
shift. Especially useful for RTTY outside ham bands,

4. Sharp Mark and Space Fitters. Greatly improves
copy under crowded, fading and weak signal condi-
tions For 170, 425, 850 H: shifts.

5+ Normal-Reverse Switch. Check for inverted RTTY
without changing sidebands and retuning.

6. Output Level Control, Adjust signal level into TU.

7. Limiter. Evens out signal variation for easier,
smoother copy.

Ptugs between receiver and TU. Mark is 2125 Hz
and Space is 2295, 2550, or 2975 Hz 10*2x6 inches.
Uses floating 18 VDC or 110 VAC with AC adapter.
MFJ-131?, $9.95.

24/12 HOUR CLOCK/ID TIMER

Switch to 24 hour UTC MFJ- 106 $19.95
or 12 hour format! Bat-
tery backup, ID timer a-
lerts every 9 minutes
after reset. Red .6 in
LEDs. Synchronizable to WWV. Alarm, Snooze func-
tion Minute, hour set switches, PM, alarm on indica-
tors, Gray/Black cabinet. 5x2x3 in. 110 VAC, 60 Hz.

MFJ ELECTRONIC KEYER

MFJ-407

$69.95

MFJ-407 Deluxe Electronic Keyer sends
iambic, automatic, semi-auto or manual, Use
squeeze, single lever or straight key. Plus/
minus keying, 8 lo 50 WPM. Speed, weight,
tone, volume controls. On/Off, Tune, Semi-
auto switches Speaker. RF proof. 7x2x6
inches, Uses 9 V dattery, fc-9 VDC or 110 VAC
with AC adapter, MFJ-1305. $9.95.

MFJ PORTABLE ANTENNA

MFJ's Portable Antenna lets you operate 40,
30, 20, 15. 10 meters from apartments, motels,
camp sites, vacation spots, nearly any electri-
cally clear location where space for a full size
antenna is a problem.

A telescoping whip (extendi to 54 fin.) is
mounted on salt-standing 6x&fl inch aluminum
case. Built-in antenna tuner, field strengnt me-
ter. 50 feet RG-5B coax. Complete multi-band-
portable antenna system that yiu can use near
ly anywhere. Up to 300 watts IEP.

MFJ-1621

$79,95

MFJ ANTENNA BRIDGE

MFJ Antenna Bridge. Trim your an-
tenna tor optimum performance Quickly
and easily, Read antenna resistance up
to 500 ohms. Covers all hams bands be-
low 30 MHz. Measure resonant fre-
quency ot antenna. Tells to lenghten or
shorten antenna. Easy to use, connect
antenna, set frequency, adjust bridge
for meter null and read antenna resist-
ance. Has frequency counter jack. Use
as signal generator. Portable, self con-
tained. 4x2x2 In. 9 V battery or 110
VAC with adapter. MFJ-1312, $995.

MICROPHONE EQUALIZER

MFJ-204

$79.95

MFJ.550

$49.95

Greatly improves transmitted SSB speech lor maxi-
mum talk power. Evens out speech peaks and valleys
due to voice, microphone and room characteristics
thai makes speech hard to understand Produces
cleaner, more intelligible speech on receiving end
Greatly improves mobile operation by reducing bassy
peaks due to acoustic resonances. Plugs between mic
and rig. 4 pin mic jack, shielded output cable. High
mid, low controls provide ± 12 db boost or cut at 490,
1170, 2800 Hz, Mic gain, on/of f/bypass switch
"On" LED. 7x2x6 inches. 9 V battery, 12 VDC or 110
VAC with adapter, MFJ-1312, $9,95,

ORDER ANY PRODUCT FROM MFJ AND TRY IT- NO
OBLIGATION. IF NOT DELIGHTED. RETURN WITH-
IN 30 DAYS FOR PROMPT REFUND (LESS SHIPPING)

■ One Year unconditional guarantee * Made in USA.

■ Add $4 00 each shipping/handling * Call or write
for free catalog, over TOD products

MFJ ENTERPRISES. INC.
Box 494 . Mrssisijppi State, MS 39762

TO ORDER OR FOR YOUR NEAREST
DEALEIt. CALL TOIL-FREE ^g

800-647IB0Q. Call 601*323 5869

in Miss, and outside continental USA
Telex 53-4590 MFJ ST KV

300 WATT ANTENNA TUNER HAS SWR/WATTMETER, ANTENNA SWITCH, BALUN.
MATCHES VIRTUALLY EVERYTHING FROM 1.8 TO 30 MHz.

MFJ'j fastest selling tuner packs in plenty of new fiaturet!

• New Styling! Brushed aluminum front. All metal cabinet

• Hew SWR/Wattmetar! Mare accurate Switch selectable
300/30 watt ranges Read forward/reflected power

• New Antenna Switch! Front panel mounted. Select 2 coax
lines, direct or through tuner, random wire/balanced line or
tuner bypass for dummy load

• New airwound inductor! Larger more efficient 12 position air-
wound inductor gives tower losses and more watts out Run up
to 300 watts RF power output. Matches everything from 1.0 to
30 MHz: dipoles, inverted vee. random wires1 verticals, mobile
whips, beams, balanced and coax lines. Built-in 4:1 balun for
balanced fines. 1000V capacitor spacing. Black. 11x3x7 inches
Works with all solid state or tube rigs. Easy to use, anywhere.

$99.95

MFJ- 941 D

NEW

FEA TUHES

RTTY/ASCII/CW COMPUTER
INTERFACE

MFJ-1Z24

$99.95

■ *» m * m

-- • ,

Free MFJ RTTY/ASCII/CW software on tape and
cable lor VIC-20 or C-64 Send and receive com*
puterized RTTY/ASCII/CW with nearly any per-
sonal computer (VIC-20. Apple, TRS-BGC, Atari.
TI-99, Commodore 64, etc.). Use Kantronics of
most other RTTY/CW software. Copies both mark
and space, any shift (including 170. 425. 850 Hz)
and any speed {5-100 WPM RTTY/CW, 300 baud
ASCII) Sharp 8 pole active filler for CW and 170
Hz shift. Sends 170, 850 Hz stiitt. Normal /reverse
switch eliminates retuning. Automatic noise limner
Kantronics compatible socket plus exclusive general
purpose socket. 8x1 Vix6 in. 12-15 VDC or 110 VAC
with adapter, MFJ-1312, $9.95.

RX NOISE
BRIDGE

Maximize
your antenna

performance! $59.95 MFJ-202B

Tells whether to shorten or lengthen antenna for
minimum SWR Measure resonant frequency,
radiation resistance and reactance.
New Feature!: individually calibrated resistance
scale, expanded capacitance range (1150 pf).
Built-in range extender for measurements be-
yond scale readings 1-100 MH2. Comprehensive
TOnuai. Use 9 V battery. 2x4x4 in.

INDOOR TUNED ACTIVE

cia/i improved/ ANTENNA

h hiaher gaM "World Grabber" rtvali
with nig ■ or wcee(js reception

of outside long wires! Unique tuned Active
Antenna minimizes intermode, improves select-
ivity, reduces noise outside tuned band, even
functions as preselector with external antennas.
Covers 0.3-30 MHz, Tele
scoping antenna, Tune,
Band, Gain, On-otl
bypass controls. 5x2x6 in.
Uses 9V battery, 9-
18 VDC or 110 VAC with
adapter, MFJ-1 31 2, $9,95, MFJ-1020A $79.85

POLICE/FIRE/WEATHER
2 M HANDHELD CONVERTER

MFI VHF

CONVEftTEl

fTFJ

**}

Turn your synthesized scanning $39.95
2 meter handheld into a hat Police/ * * MFJ
Fire/WBather band scanner ! 1 I -3i 3

144-148 MHz handhelds
receive Police/Fire on 154-
158 MHz with direct fre-
quency readout Hear
NOAA maritime coastal
plus more on 160-164 MHz

Convener mourns between

Handheld and rubber ductoy

Feedthru allows simultaneous

scanning of both 2 meters

and Police/Fire bands. No

missed calls. Crystal controlled Bypass/Off

switch allows transmitting (up to 5 watts). Use

AAA battery. 2V*xV/i%Yh in. BNC connectors,

MFJ/BENCHER KEYER
COMBO

MFJ-422

$109.95

The best or
all CW worlds

a deluxe MFJ Keyer in a compacfTonfiguration
that fits right on the Bencher iambic paddle!
MFJ Keyer - small in size, big in features Curtis
8044-B IC, adjustable weight and tone .front panel
volume and speed controls (8-50 WPM) Built-
in dot-dash memories Speaker, sidetone. and
push button selection of semi-automatic/tune
or automatic modes Solid state keying Bencher
paddle is fully adjustable, heavy steel base with
non-skid feet. Uses 9 V battery or 110 VAC with
optional adapter. MFJ-1305. 6.95.

VHF SWR/WATTMETER

LOW cut MFJ-312 $29.95

VHF SWR/

Wattmeter!
Read SWR
(14 to 170 MHz)
and forward/
reflected power

rCm<<

fTJJ

at 2 meters. Has 30 and 300 watts scales. Also
read relative field strength. 4x2x3 in.

1 KW DUMMY LOAD

MFJ-250$39.95

Tuna up fttt, extend *^^^J^^^+
life of finals, reduce ^™^^^5^
QflMf Rated 1 K W CW - /m *»*■

or 2 KW PEP for 10 mm

utes Half rating for 20

minutes, continues at

200 W CW. 400 W PEP

VSWR under 1,2 ta 30

MHz. 15 to 300 MHz.

Oil contains no PCB

50 ohm non-inductive resistor. Safety vent.

Carrying handle. 7VtxB¥* in.

24/12 HOUR CLOCK/ ID TIMER

MFJ- 106

$19.95 H^/

Switch to 24
hour UTC or

12 hour format!
Battery backup
maintains ttme during power outage, ID timer
alerts every 9 minutes after reset. Red LEO .6 Inch
digits. Synchronizable with WWV, Alarm with
snooze function, Minute set, hour set switches.
Time set switch prevents mis-setting. Power out,
alarm an Indicators. Gray and black cabinet. 5x2x
3 inches. 110 VAC. 60 Hz.

DUAL TUNABLE SSB/CW/RTTY
FILTER MFJ-7S2B $99.95

/fff

# * o o

Dual flltart give unmatched performance!
Trie primary filter lets you peak, notch, low
pass or high pass with extra steep skirts.
Auxiliary filter gives 70 db notch, 40 Hz peak.
Both filters tune from 300 to 3000 Hz with
variable bandwidth from 40 Hz to nearly flat.
Constant output as bandwidth is varied; linear
frequency control Switehable noise limiter for
impulse noise Simulated stereo sound for CW
lets ears and mind reject QBM. Inputs for 2 rigs.
Plugs into phone jack. Two watts for speaker.
Off bypasses filter 9-18 VDC or 110 VAC with
optional adapter, MFJ-1312, S9.95.

ORDER ANY PRODUCT FROM MFJ AND TRY IT-NO
OBLIGATION. IF NOT DELIGHTED, RETURN WITH-
IN 30 DAYS FOR PROMPT REFUND (LESS SHIPPING)

• One year unconditional guarantee * Made in USA.

• Add HOG each snipping/handling * Call or wiii*
for free eatilog, over 100 product!.

MFJ ENTERPRISES, INC.
Box 494. Miiiiulppl SUM. MS 39762

TO ORDER OR FOR YOUR NEAREST
DEALER, CALL TOLL-FREE

800-647-1800. Call 60^323-5869

in Miss and outside continental USA
TeJex 53-4590 MFJ STKV

-9

VfSA'

EDITED BY PERRY OONHAM KK2Y

PUBLISHED REPORTS that 73 had been put
up for sale by its parent company, CW Com-
munications, Inc., were absolutely true.
GWCI felt that 73, as an amateur-radio mag-
azine, did not fit in with its 50 or so other
computer publications, Pro-73 forces, how-
ever, suggested that modern ham tech-
niques, such as packet radio, are Indeed
high tech and also that selling a successful
property might not be a sound idea, GWCI
subsequently withdrew its offer to sell and
committed its Ml backing and support to
73. As a result, we believe our readers and
advertisers will be seeing some exciting im-
provements in 73 as we enter our 25th-anni-
versary year!

SOFTWARE PIRATES are looking over their
shoulders after Kantronics successfully
prosecuted Cindy Gladwell of Cindy's Com-
puter Software, Cindy sold a pirated copy of
Kantronics" Hamtext computer program,
along with a full set of documentation, to
Mike Forsyth at the Michigan State ARRL
Convention in Detroit. Mike happens to be
Marketing Director of Kantronics. Ms. Glad^
well was served an injunction to halt all
software-reproduction activities and di-
rected to forfeit $2000 in damages to Karv
Ironies.

THE BID FOR 220 MHZ by several commer-
cial interests has been stalled at press time.
The petition by Sideband Technology, Inc.,
RM-4831, has been put on hold while the
FCC investigates charges of conflict-of-in-
terest filed by the Inland Waterway Commu-
nications System. Art Reis K9XIT editor of
220 Notes, has asked for a congressional
investigation into the activities of the FCC
Office of Science and Technology, which
seems to be behind the bid for 220.

THE MOUISfT GREYLOCK REPEATER was

saved from an untimely demise recently

when Governor Dukakis of Massachusetts
signed into law a bill giving the Northern
Berkshire Amateur Radio Club a twenty-
year lease on the repeater site. Overwhelm-
ing support from amateurs across the coun-
try in the form of cards and letters was
Instrumental in preserving this heavily-
used machine.

A SPREAD SPECTRUM BEACON is now on

the air near Falls Church VA. According to
Chuck Phillips N4EZVt the system operates
from 144.5 to 147.7 MHz, with a hop rate of
10 per second. Output power is 25 Watts,
and the beacon transmits a series of Vs
after an identification that is simulcast on
the AMRAD repeater, 147.21/,81. After nor
mal business hours, the beacon may be
turned on by sending the touchtone™ dig-
its 4-3-2-1 on 144.5 MHz. Chuck has plans
for HF spread-spectrum beacons on the 10-
and 15-meter bands. If you are interested in
the application of this fascinating tecl>
nique to amateur radio, contact Chuck Phil-
lips at Tactical Communications, Inc., 5711
B Center Lane, Falls Church VA 22041.

PACKET RADIO will be the subject of the
next North American Teleconference Radio
Net (TRN), heard through over 150 gateway
stations across the United States, Two of
packet radio's pioneers, Lyle Johnson
WA7GXD and Harold Price NK6K, will be
the featured speakers, lyle is president of
the Tucson Amateur Packet Radio Society
(TAPR) and was the primary influence be-
hind the development of the TAPR termlnal-
node-cont roller (TNG) hardware. Harold is a
director of TAPR and worked on the soft-
ware end of the TAPR TNC. For a complete
list of TRN gateway stations, send an SASE
to TRN Manager, c/o Midway Amateur Ra-
dio Club, PO Box 1231, Kearney NE 68847-
1231, or check CompuServe's Hamnet XA4
database.

Massachusetts Governor Michael Dukakis chatted with nearly 125 hams after signing leg-
islation saving the Mt. Greytock repeater. That's Warner WtYBTon the right

8 73 Magazine * November, 1984

SEVERAL ARRL QSL BUREAUS have new

addresses.

Third call area: CCARS, PO Box 448, New

Kingston PA 17072*0448.

Fourth calf area, twr>letter prefixes (AA4t

KB4, etc): Sterling Park ARC, Call Box 599f

Sterling Park VA 22170.

Fifth call area: ARRL W5 QSL Bureau, PO

Box 44246, Oklahoma City OK 73144.

US Virgin Islands: Virgin Islands ARC, GPO

Box 11360, Charlotte Amalie. St, Thomas,

Virgin Islands 00801.

VE5: VE5 QSL Bureau, B, J, Madsen

VE5ADA, 739 Washington Drive, Weybum,

Saskatchewan, Canada S4H 2S4.

VE6: CRRL Incoming Bureau, N. R Walt ho

VE6VW, General Delivery, 9714 94th Street,

Mortnville, Alberta, Canada TOG 1P0.

SWL: Mike Witkoski, 4206 Nebel Street,

Stevens Point Wl 54481.

THE FAILURE RATE of the new volunteer-
given amateur exams is exceptionally high.
Most groups report that only 25% of their
applicants are upgrading. There's a good
deal or contusion regarding who is actually
running things— although the W5YI Report
and the ARRL are both Volunteer-Examiner
Coordinators (VECs) for all 13 districts,
many districts have up to seven separate
groups acting as VECs. In some areas, the
district VECs are bowing out in favor of the
League, which is still trying to bully its way
into control of the program. In any case, the
FCC will be out of the testing business at
the end of the year. For a complete list of
VECsh send an SASE to 73, Pine Street, Pe-
terborough NH 03458, Attn; VEC LIST.

FCC HAS NAILED another jammer. Dave
Meehan W7IVK has had his Advanced-class
amateur license suspended for one year for
willfully interfering with communications
on the 40-meter band. After the year is up.
Meehan will be permanently barred from
operating in the 7235-to-7280*kHz segment
of the band,

$140,000 WORTH OF ILLEGAL CB GEAR

was seized by US Marshals recently in one
of the nation's largest radio-related raids.
Most of the equipment consisted of linear
amplifiers and subassemblies destined for
use in the CB service, The distributor, D&D,
Inc., of Shelby NC, faces fines of up to
$10,000 and prison sentences for its viola-
tion of the Communications Act of 1934,

CONGRATULATIONS TO ROY NEAL
K6DUE on his new duties as Deputy Bureau
Chief for News Operations for NBC. Roy
had previously served as the science cor-
respondent for the network, giving live on-
the-atr commentary during most of NASA's
space shots. Good luck, Roy!

THIS MONTHS NEWS was courtesy of the
W5Yi Report, Wesifmk, and WA1HXQ.

^300

ttaiden provides major financial support to the Neighborhood Crime Prevention Coordinating Committee,

Like a smoke detector protects
yon from fire, a Uniden*
Bearcat* Scanner Radio is a
simple way to help protect you
from neighborhood crime.
Because if a crime wave hits,
you'll be the first to know about
it with up-to-the-minute police
reports. And youll be ready to
take precautions against the
kind of people who do their
shopping at night.

Gel up to $50 back on Uniden' Bearcat4 Scanners.
To set Hie rebate on the Uniden* Bearcat* Scanner you've
purchased, send: (1 ) original dated saJes s3ip (non-retumaWe},

(2) purchase confirmation cut from carton flapr and (3) this
completed request to: Crime Detector Rebate, RO. Box 50206,
Indianapolis. Indiana 46256.

Please circle the scanner purchased:

[1 ) BC-300/S50 Rebate

(2) BC-21QXUS25 Rebate
{3) BC-100/S25 Rebate

(4) BC-20/?0/$20 Rebate

(5) BC-250/S20 Rebate

(6) BC-220/$20 Rebate
(7}BC-260/$l5Rebate
(Q)BO20l/ $15 Rebate

(9) BO20G/$1Q Rebate
{10) BC-160/S6 Rebate
0DBC-t55/$5 Rebate

(12) BC- 1 51 /$5 Rebate

(1 3) SC-S-6/$5 Rebate

(1 4) BC-5S$5 Rebate

(15) BCM 5/55 Rebate

Fin* initial Middle Initial

Last Name

Address

Crty State Zip

Requests must be postmarked by December 8. 1984.

Offer v^Iilj Qf|(y gfl pUft£tA9a rnede Ij^twH^n October l , i@S4 and NovemDSf
25, 1984 All requests musl be postmarked by December 8, -964. Umif of
one UnKJen ' Bearcat" Scanner per household and/or consumer, repaid-
less of number of Uniden' Bearcat ' Scanners purchased1 This is a con-
sumef rebate offer ptfy Resellers, companies and employees of Unndef>*
^heir adwdising agencies, distributors and retailers are not eligible This
official coupon must accompany ail requesls. ajid may not be reproduced.
This offer may not be used in conjunction wrth any olher rebate offer from
Uniden' Bearcat." Offer good only in USA Void where taxed or prohibited
by [aw. Allow 6 -8 weeks for delwery of check-

<s>

& 19-64 Uniden Corporation ol America

Color Computer SSTV: Part I

Turn your CoCo into a complete SSTV terminal!
How? First, build this high-resolution display system.

Photo A. Multimode display hoard, showing the physical
size oi a production display interface. The board has 16K of
display memory.

10 73 Magazine * November, 1984

Clayton W. Ahrams KbABP
1 756 Comstock Lane
San lose CA 95124

This two-part article de-
scribes a high-resolu-
tion display system for the
Radio Shack Color Com-
puter® (CoCo). This system
provides the CoCo computer
with more display capability
than any low-cost computer.
You might ask why you

Dr. Ralph A. Taggan WB8DQJ
602 /efterson Street
Mason Mt 488S4

should use your CoCo to
display and generate televi-
sion images. One answer is,
for communications.

Imagine taking your CoCo
with a hardware-software in-
terface and connecting it to
amateur-radio equipment
and transferring a picture to

Photo B. Multimode CoCo interface board, which plugs into
the expansion interface of the CoCo, A 26-pin fiat cable inter-
connects the interface board and the display board.

someone miles away, or re-
ceiving weather-satellite
pictures. The digital-tele-
vrsiorhdisplay field is one
which has not been explored
by the amateur-computing
community, and only a
small amount of commer-
cial equipment exists for
such applications. In this ar-
ticle, instructions will be
provided to construct a card
to display high-resolution
images and provide inter-
faces to receive weather-
satellite pictures or ama-
teur-radio SSTV.

Before plowing ahead with
a lot of technical jargon and

confusing terms, some defi-
nitions are in order,

Background

In display terminology
two terms are particularly
important. These terms are
used also in television. The
first is pixef, and it relates to
the smallest element of a
picture which can be seen
on the TV screen. In normal
TV, the pixels are so small
that they tend to blend to-
gether to form a contiguous
image. In digital TV, a pixel
is a unit in the picture which
can be seen by the unaided
eye. Each pixel in digital TV
has an intensity or discrete
color The main goal in dig-
ital TV is to place the most
pixels on a line to form the
smoothest image. To do this
as well as standard TV does
takes a lot of complex and
costly circuitry.

The second term is num-
ber of lines per picture. In
the USA, standard TV has
262 lines per frame or 525
lines per interlaced picture.
In digital TV, the number of
lines is often reduced from
normal TV for cost and sim-
plicity reasons.

If a digital-display system
could be developed around
a standard microprocessor
system, the system would be
very versatile. The few com-
mercial display systems
which have been developed
to date have some disadvan-
tages.

Expandability. Micropro-

cessors have been installed
in some of the new display-
system designs. All of these
units are not user-program-
mable. Most vendors would
rather provide users with
new units when their func-
tion is to be expanded. If a
system were to be based on
a commercial microproces-
sor with a good software
base, the system could be
expanded as technology
progresses.

Fixed Architecture. Most
commercial systems are built
around a large planar board
with lots of ICs and discrete
components. These units are
designed for a specific appli-
cation and a limited life
span. Adding interfaces like
FAX and other applications
is difficuft. For this reason,
the modular approach of
functional units connected
to a microprocessor makes
good sense.

Up to a few years ago,
digital TV was not possible.
With the explosion of the
semiconductor industry, the
price of ICs has fallen to a
level which makes this eco-
nomically possible. Most of
the early digital TV scan
converters used were hard-
ware-only devices. These
units were very dumb and

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SSTV

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EXPANSION
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SSTV

RECEIVE
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SSTV
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VIDEO

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HAM

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TRANSMITTER

ANT

Fig. 1. System block diagram, showing the interconnection of
the computer and ail the interfaces.

could only generate and dis-
play images. The explosion
of digital computers and the
incorporation of digital
displays in computers
makes the whole concept
very exciting* Once an im-
age is placed in the com-
puter, almost anything is
possible: communications,
image analysis by computer
for manufacturing inspec-

tion, medical applications,
or art forms for their own
sake.

Two applications will be
described in this article. The
first application is amateur-
radio slow-scan television;
the second is weather-satel-
lite reception. While the ap-
plications are similar in that
they require some means of
picture displaying and a

LATCH
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DATA 9US

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Fig. 2. Display block diagram, showing how the display interface functions. Only the impor-
tant ICs are shown.

73 Magazine • November, 1984 11

Fig, 3, Display board schematic.

hardware interface to prop-
erly condition the signal,
and each requires tradeoffs
and compromises to achieve

12 73 Magazine * November, 1984

adequate results, we will
treat them separately in
order to do an adequate job
on each.

SSTV

Since all interfaces use
simple hardware, the heart
of the system is software. It

would be impossible to pub-
lish an entire software pack-
age in an article of this type.
To date, thousands of lines

Photo C The prototype board by K6AEP was one of the first
display boards constructed. The board is plugged into a
CoCo. The board was point-to-point wired and is exactly tike
the schematic in Fig. 3. All of these photos in part I of this arti-
cle were generated by this board. The same results can be
achieved by the commercial display boards.

of code have been devel-
oped. What will be provided
here is a technical descrip-
tion of how the software and
hardware interfaces func-
tion and the steps necessary
to develop code. You will
find it possible to modify the
concepts we present for in-
terfacing with any micropro-
cessor system.

The Display Criteria

Since the main goal of the
display card is to produce
quality images, it is impor-
tant to make the picture
density as high as possible.
This requires the addition of
RAM memory in which the
image will be saved and dis-
played. Experimentation
by many people over a peri-
od of years has determined
that a minimum of 128 pixels
per line is required tor low^
resolution images, with at
least 16 gray levels. Some
experimentation which I
conducted in mid-1982 indi-
cated that a minimum of
256 colors per pixel is re-
quired to display low-resolu-
tion color-TV images.

Armed with this informa-
tion, a design criteria of 256
pixels per line, 16 gray
levels, on 128 lines was
defined for black and white
displays. This equates to a
display size of 16K of dis-

play RAM. With a little
clever programming and
slight reconfiguration of
data bits, a total of 256 col-
ors can be displayed for
each pixel with 128 pixels
per line on 128 lines.

Obviously, a system can
be constructed with higher
resolution, but as the digital-
display density increases so
do the cost and complexity.
Since this project was cre-
ated for the average hobby-
ist with a limited budget the
above criteria seem adequate
for today's technolgy.

Hardware Design

It is unfortunate that no
off-the-shelf module or de-
sign provides the necessary
ingredient to display TV-
type images. Many manu-
facturers have developed
display-controller ICs for
computer terminals, but in
most cases they are unus-
able in TV applications. One
of the few ICs which make
the job easier is the Motoro-
la 6845. This \C is the heart
of the display board and
causes the image to be dis-
played.

The card is designed to at-
tach to the Radio Shack
TRS-80C Color Computer,
but the design concept is so
basic that it can be altered
to attach to any microcoria

Photo D. A multimode SSTV receive interface. This board is a
commercial version of the SSTV receive interface. The phys-
ical size is the same as the display board.

puter The card functions by
first generating or placing an
image in the main memory
of the computer The TV im-
age can be received through
a slow-scan demodulator at-
tached to the receiving
equipment then connected
to the joystick input of the
computer.

Another method of image
generation is to attach a spe-
cial hardware interface to
the display card and frame
grab the image into the
display card from a TV cam-
era. At this time the TV-cam-
era interface has not been
developed. When using the
TV camera, the image will
be loaded into the video
card first and then trans*
ferred by computer soft-
ware to main memory.

System Description

Fig- 1 provides a block
diagram of the entire system
The TRS-80C in this applica-
tion acts as an intelligent
controller. All interfaces are
very primitive and cannot
function without intensive
control from the computer,
When an image is to be dis-
played from the receiver,
the audio tones are first
detected by the display de-
modulator and converted to
two types of signals: sync
pulses and a dc voltage
which changes as a function
of the input audio fre-
quency, These signals are

connected to the CoCo's
RS-232 input and the joy*
stick input

The joystick input is ac-
tually an analog-to-digital
converter which can be used
to digitize slow-scan TV
video into picture informa-
tion. All of the operation is
controlled by software in
the CoCo. When digitized,
the pixels are transferred to
the display card and imme-
diately displayed. For
transmission, the image is
first created by software and
placed in the CoCo's mem-
ory. To transfer the image to
a transmitter, the sync
pulses are controlled by the
RS-232 output line and the
video is controlled by the
computer's cassette output,
which is a digitako-analog
converter.

The above process is true
only for black and white
television. Color digital TV is
more complex. Color TV is
developed or transferred
from three image planes
Each plane consists of the
three prime colors (red,
green, and blue). When the
three frames are mixed to-
gether, a color image is
formed. The image can then
be transferred to the display
card. The transmission
method of colored televi-
sion is either by frame-
sequential or by a colored
line-sequential multiplexed
method.

73 Magazine * November, 1984 13

S5TV
IN FROM
RECEIVER

+ iav

RIGHT HAND
JOYSTICK

Tj-

-Ft

TRs-aoc

PIN I

♦ PIN 5-GND

i OK

BRIGHTNESS

TRS-flOC

RS-232
PIN 2

-^ PIN 3-GND

F/g+ 4, SSTV/FAX receive demodulator schematic showing a front end which can be used with
the computer to display both SSTV and FAX images. The FAX application can be used only on
the HF bands.

The block diagram of the
display card is shown in Fig,
2 and the schematic is
shown in Fig. 3. The follow-
ing sections describe the
major functional parts of
the display board.

Display Board

The display board is at-
tached to the expansion port
on the side of the CoCo. This
port provides connection to
the address, data, and con-
trol signals of the 6809E

MPU, Wiring to the CoCo
must be as short as possible;
less than one-half-inch leads
are a must The data lines
are connected to both the
eight RAM ICs and the VDG
U18 (6845) display-controller
IC through a data bus trans-
ceiver (U20). The R-W line
determines if the CPU is
reading or writing to the
board.

In order for the display-
controller IC to function,
you must first write data to

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its 18 internal registers. Only
three address bits of the
6809 CPU IC are connected
to the card. These low-order
address bits select the mode
which you are performing,
The SCS line on the TRS-80C
connector is used to select
address FF40- The interface
E line is the enable signal
from the 6809 CPU. This line
is used to synchronize the
6845 to the CPU IC for
writing to its internal regis-
ters.

1. Functional Selection.
All internal functions of the
card are software-selected
by a U14 (74LS138). The
functions are shown in

Table 1 and are described in
more detail in the program-
ming section of this article.

2. Random Access Mem-
ory, This card contains 16K
of display RAM (U1 to U8) in
eight 2K-by-8-bit ICs. Static
RAM was used so as to
make the design as simple
as possible. Dynamic RAM
has the advantage of lower
cost but requires extra cir-
cuitry to develop RAS and
CAS signals, and it is dif-
ficult to correct and diag-
nose problems when they
occur, Simple changes can
be made to the circuit to
add more display memory.
Modifications have been
made to add 32 K RAM. The
board can then display 256
pixels on 256 lines, black
and white. Television pic-
tures in this mode are start-
ing to approach standard US
TV quality pictures.

Control of read or write to
the RAM is determined by
U25 and U26. During most
of the time, RAM is in the
read mode, This causes the
video data to be valid on the
internal data bus. When data
is written, it is transferred to
and from the CoCo through
bus transceiver U20 to the
RAM ICs.

3. Video Display Gener-
ator The VDG U18 is the
heart of the display board.
This integrated circuit has
18 registers. In order to
make the board operational,
the registers must be pre-
loaded before a picture can
be displayed on the card.
This IC is used to develop
the video refresh timings of
the RAM. By simply chang-
ing the initialization values,
either SCMHz or 60-Hz video
can be displayed.

An example of CRT initial-

^CRITICAL COMPONENT USE
POLYESTER FILM (MYLAR J

* + IO TO 20V

* SSTV [I VOLT P/P] TO
TRANSMITTER

Fig, 5. SSTV modulator, used to transmit SSTV pictures on the
HF amateur bands.

14 73 Magazine • November, 1984

ADDRESS

SIGNAL

FF40

VGO VDG controller address register

FF41

VG1 VDG controller data register

FF42

Spare

FF43

Spare

FF44

Reset— reset RAM address counter

FF45

Select— send picture data to card

FF46

Frame Grab— TV camera— reserved

FF47

Color— TV camera — reserved

Table 1.

* ASSEMBLER EXAMPLE FOR CODING A PROGRAM

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Fig, 6, Pro-am example for SS TV/FAX receive, written in 6809
assemb/er language, to demonstrate how easily a receive roth
tine can be written. The routine cannot be executed without
software additions.

iz3tion is contained in the
programming section. The ini-
tialization constants were
chosen to display an image
with the minimum amount
of tearing and proper cen-
tering on a 9-inch RCA Color
Trak TV set The TV set was
interfaced to the video card
by a Radio Shack rf modu-
lator.

4. The Master Clock, The
master clock is a crystal
oscillator operating at 6,144

MHz and is generated by a
74LS00 U21 IC. This crystal
frequency was chosen to
display an active picture
time of 42 microseconds,

The initialization software
of the 6845 is used to fine-
tune this display time. A
counter is used to divide the

clock frequency by 2 and 4+

5, The Internal Data and
Address Bus. The entire card
is designed to display an
SSTV picture continuously.
Since the card must be
powered by an external
source different from the
computer, power can be
dropped on the computer
and the display will still be
active.

When a picture is to be
displayed on the card, the
refresh process is inter-

PP44

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DURATION, THE HORIZONTAL
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• #>R|_AC» E5#ti HZ
*

TAOLE RMt 16 J 6 ftfES OF DATA

• COUNTERS IN RAH
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END XM1T

Fig. 7. Program example for SSTV transmission.

rupted for a few microsec-
onds. This causes a small
white line to appear on the
display. The direct memory
access (DMA) scheme used
on the card is very simple in
principle. Normally the ad-
dressing of RAM is from the
VDC through two tri-state
buffers, U16 and U17. When
the CPU writes to RAM, not-
RAM select is brought low
and the RAM address is gen-
erated by two counters, U10
and U11. At this time, VDC
buffers U12 and U13 are
floated on the address bus
and the counter buffers
drive the bus. After the RAM
has been written, the
counter advances to the
next address,

6, Display Data. The dig-
ital display data is latched
from the data bus at the cor-
rect time by the 74LS374

U24; the black and white is
twice the rate of the color.
The 74LS374 U39 is latched
from the data bus every 650
nanoseconds. This data is
fed to both the black and
white and color modulators
A multiplexer is used to feed
the black and white mod-
ulator. The multiplexer
74LS157 U 30 is clocked at a
rate of 325 nanoseconds,
which is 256 pixels per line
of SSTV.

7. Black and White Mod-
ulator. The black and white
modulator is fed from the
multiplexer, U30. which
feeds first the 4 low-order
bits (nibbles) then the high-
order nibble. The output of
the multiplexer is connected
to a simple digitakoanalog
converter (D/A) which con-
sists of a transistor and 10 re-
sistors*

73 Magazine • November, 1984 15

Photo E. RTM Circuit Board's SSTV transmit interface placed
on a Tandy prototype card. The card can be plugged into a
card cage or a socket for ease of removal and repair

Sync pulses are generated
by the VDG U1 3, are ORed
together by U27, then mixed
with video data in the single-
transistor D/A converter.
Since 4 bits are used, the
modulator is restricted to 16
possible gray levels per
pixel.

A picture-smoothing ca-
pacitor (1000 pF) was placed
across the 510-Ohm resistor
to ground at the D/A sum-
ming point. The value of this
capacitor can be optimized
to produce the picture most
desirable. The absence of
the capacitor produces a
more digitized picture.

8. Color-SSTV Modulator.

The color-SSTV modulator
consists of three ICs,
LM1889 U32, LM1886 U31,
and a 9602 U33. The SSTV
modulator functions by
clocking the picture data on
the latch. The data is next
transferred to the LM1886
which converts the digital
pixels to difference and
luminance signals. These
signals are internally con-
nected to the color modu-
lator which provides com-
posite color video.

Three additional signals
are provided to the LM1886,
blanking, sync pulse, and a
burst gate. The burst gate is
developed from a 9602

ASStMbLtlk COPE ex.
CONTROLLER TQ THE

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•FF4W

CRT

CONTROLLER ADDRESS PORT

FF41

PDRT1

ecu

•FF41

CRT

CONTROLLER DATA FORT

CRT

CONTROLLER 1C

: eeoateS

9S13

C»

CONCR.T

*C0

RE6

HORiZ TOTAL

0414

urn

FOB

128

REG

CHAR /ROW

fcifalS

FCS

1?2

REE

HSYNC POSITION

0616

FCB

REG

HSVNC WIDTH

0617

FCB

*79

REG

VERT TOTAL

0613

FCB

*35

REG

VERT SYNC ADJ

061'?

FCB

«7F

REG

CHAR ROWS /FRAME

061A

FCB

*fiu

REG

VSYNC P0S

06 1 U

**■

FCB

REG

INTERLACE flQDE

061 C

FCB

REG

SCAN LINES/ ROW

3&] ::■

£>a

FCB

REG

CURSOR START

(06 IE

FCB

REG

CURSOR END

0MF

612

FCB

REG

MSB START ^/JDEO

0620

FCB

REG

L.BB STOP VIDEO

13621

1 LB

RES

ItSB L/P

0622

FCB

REG

LB© L/P

END

Fig. 8. Initialization of the display board; this is an example of
how the display board 6845 can be initialized,

16 73 Magazine • November, 1984

which is a dual single shot
The burst gate serves as a
reference signal. The loca-
tion of the burst gate must
be adjusted to the correct
position on the horizontal-
blanking back porch. This is
the only adjustment on the
board.

The digital data to the
LM1886 (U32) is in the for-
mat of 3-by-3-by-2 bits of
red- green-, blue-frame in-
formation. For example, the
lower three bits of the byte
are the red-frame informa-
tion, the next three bits are
for the green frame, and the
most significant bits are for
the blue frame.

This configuration allows
for a possible 256 combina-
tions which are unique col-
ors. Since the LM1886
allows for nine bits of digital
data to be inputted, the LSB
is tied to the MSB of the
blue-frame input of the IC to
make the bit pattern com-
patible with the eight-bit
display-data bus. This trick
allows for black and white
images to be displayed.
Without this modification,
the black and white images
would have a blue hue.

9+ TV- Camera Interface. A
number of points are identi-
fied in the logic of the dis-
play-board interface for the
inclusion of a TV camera at
a later date. The camera in-
terface will function as fol-
lows: When the 74LS0O U9-5
is brought low, the counter
will drive the address bus.
The TV-camera pixel counter
will be incremented by the
input U9-9. The RAM read/
write is controlled by U26(
and the TV-camera input at
U25-12/13 will cause the
RAM to switch to the write
mode. Pixels can next be
written to the RAM from the
data bus.

Receive Demodulator

The receive demodulator
is a device which decodes
the SSTV tones into a dc
voltage proportional to in-
put frequency and digital
sync pulses. This circuit con-
verts video tones of 1 500 Hz
and 2300 Hz to 0 volts and 5

volts, respectively. A fre-
quency of 1200 Hz converts
to a positive digital pulse.

The circuit consists of
four stages of filtering and
one stage of pulse shaping.
Its schematic is shown in
Fig- 4.

The decode by this circuit
is not only compatible with
SSTV but can also be used
to decode FAX pictures
transmitted commercially
on the HF frequencies.

The SSTV video enters the
demodulator through the
limiter circuit, U1 . The
limiter is connected to two
bandpass filters, U1 and U2(
which have bandpasses of
approximately 1100 to 2400
Hz. These filters are con-
nected to two diode-dis-
criminator circuits which
are combined into a differ-
ential amplifier. The signal
at TP2 is the carrier frequen-
cy of the audio signal with
amplitude modulation. The
signal in this path with TP3
(U3 and U4) is a series of
bandpass amplifiers which
allow only the video com-
ponents of 1500 and 2300
Hz to be passed.

The path of TP4 and U4 is
used for the detection and
waveshaping of the sync sig-
nals. The Schmitt trigger,
7414, is used to develop fast
rise times of the sync signals
and to produce TTL-level
voltages. The sync output
from the circuit contains
both horizontal and vertical
sync pulses.

Modulator Circuit

The modulator interfaces
to the CoCo and is the cir-
cuit which produces the
SSTV audio tones for the
transfer of video informa-
tion in computer memory.
The interface, shown in Fig.
5, connects to the CoCo
through the RS-232 and cas-
sette-output ports. The cas-
sette-output port is a 6-bit
digital-tr>analog converter.

The circuit functions as
follows. When the RS-232
output is raised, the modu-
lator outputs a sync fre-
quency of 1200 Hz. To gen-
erate video tones, a ground

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To get ihe fastest delivery from CE of arty
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directly to our Scanner Distribution Center.*
Michigan residents please add 4% sales tax or
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orders are accepted from approved govern-
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10% surcharge for net 10 billing, AH sales are
subject to availability, acceptance and verifica-
tion. All sales on accessories are final Prices,
terms and specifications are subject to change
without notice, All prices are in U.S. dollars. Out
of stock items will be placed on bacKorder
automatically unless CE is instructed differ-
ently. A $5,00 additional handling fee will be
charged for alf orders with a merchandise total
under $50.00. Shipments are RO. B.Ann Arbor,
Michigan, NoCOD's, Most products that we sell
have a manufacturer's warranty. Free copies of
warranties on these products are available
prior to purchase by writing to CE International
orders are Invited with a $20.00 surcharge for
special handling inaddit ion to shipping charges.
Non-certified checks require bank clearance.
Mail orders to: Communications Electron-
ics!" Box 1002, Ann Arbort Michigan 48106
LLS,A Add S 7. 00 per scanner, radar detector or
CB or SI 2.00 per shortwave receiver for UP.&
ground shipping and handling in the continental
USA For Canada, Puerto Rico, Hawaii, Alaska,
or APO/FPO delivery, shipping charges are
three times continental U.S. rates. If you have a
Visa or Master Card, you may call and place a
credit card order. Order toll-free in the U.S. Dial
8O0-521-4414. In Canada, order toll-free by
calling 800-221*3475. WUI Telex CE anytime,
dial 671*01 55. If you are outside the U.S, or in
Michigan dial 313-973-8688. Order today.

Scanner Distribution Center"" and CE logos are irade-
marks of Com m u n Icat ions Electronics." Ad*07Qia4-E
t Bearcat js a rogisiered trademark of Uniden Corporation,

OrderToll Free... call

1-800-521-4414

COMMUNICATIONS
ELECTRONICS'

lTH

296

Consumer Products Division

Bta Phoenix G Box 1002 G Ann Arbor. Mtchpgan 48106 U S A
C*H TOLL-FREE 400-521-4414 Of ttutaW* U.S.A. 31 3 973 MAS

w See List of A cfVe/ risers on page 88

73 Magazine * November, 1984 17

Photo F. A color -SSTV picture displayed on a Tl color
monitor attached to the K6AEP prototype display board. The
picture was received over amateur radio on 28.680 MHz by
the TRSSOC and saved on tape. The picture was generated by
WB&UNB in St Louis, Missouri

Photo C A color-SSTV picture generated by W&LMD and
placed on audio cassette tape and loaded into the TRS-80C.
This picture shows the effect of color contouring. Since the
display has only 256 possible colors, the shading in the flesh-
tone regions are noticeable.

potential is applied to both
the RS-232 output and the
video input This causes a

video frequency of black
1500 Hz to be outputted.
When the video level is in-

creased to approximately
1.1 volts by outputting a dig-
ital F to the cassette-output
port, a frequency of 2300 Hz
is generated. By the use of
software, an SSTV picture
can be generated by soft-
ware and transmitted.

The Software

The preceding section
provides you with a com-
plete description of the
hardware requirements for
SSTV applications Obvious-
ly, the hardware performs
few useful functions with-
out the software. The intent
of the hardware design is to
place the burden of all tim-
ings and control on the soft-
ware. This allows for the
maximum utilization of all
hardware interfaces. There
are the following limiting
factors.

Microprocessor Speed,
The reception or transmis-
sion of images is limited by
the rate at which the instruc-
tions can be executed by the
CPU. Fortunately; the 6809

18 73 Magazine * November, 1

microprocessor is very fast
due to its rich instruction set
and its ability to process
16-bit data even though the

processor is on an 8-bit data
bus.

Internal Analog-to-Digital
Converter. All of the pre-
ceding interfaces are based
upon the use of the internal
analog-to-digital converter
in the TRS-80C This feature
is used to process joystick
inputs when playing games.
The A/D converter uses a
simple successive-approxi-
mation technique and is
driven by the microproces-
sor When this technique is
used, the conversion rate is
quite slow. The tightest loop
which can be written to uti-
lize this feature allows for
the conversion of 4 bits of
data in approximately 75 mi-
croseconds. Even though
this is slow, the rate is suffi-
cient to allow for SSTV and
FAX reception.

Software Functions

In this section, the soft-
ware and hardware will be
described in a simple, broad,
overview approach. The
principles described can ap-
ply to SSTV, FAX, or any
other communications mode

984

which uses a slow rate of
transmission or reception
Normally this type of soft-
ware is called firmware or
microcode. Since the soft-
ware is extremely time-de-
pendent, care must be taken
with each instruction writ-
ten to make the time as
short as possible. The de-
scription of the software
routines will be general
enough so that they can be
recoded for any general*pur-
pose microprocessor. One
important point is that all
software must be written in
the microprocessor's native
assembler language. High-
level languages are too
slow. Even the most effi-
cient compilers are too slow
for SSTV applications.

Receive Software. In Fig. 6
is a simple routine which will
receive a picture through an
interface attached to the
CoCo joystick and RS-232 in-
put ports. The interface can
be either the SSTV receiver
(Fig, 5) or the FAX receiver
(Part II of this article). In
both cases the software is
identical. The only change
in both modes is the delay
between pixel reception
The software routines pro-
vided are not complete but

they do provide an example
to readers ambitious enough
to learn assembler-language
programming The program
functions as follows.

The first six lines of code
initialize program constants
for the correct number of
lines and place the CoCo
multiplexer to the correct
joy stick- in put- con nee tor
pin. The hardware counter
PORT3 is reset to the upper
left-hand corner of the pic-
ture area, As soon as a ver-
tical sync signal is received
on the interface, the pro-
gram starts to digitize the
picture.

The A/D routine converts
the analog input voltage to
four digital bits and places
this information into the
lower nibble of a byte. The
byte is next placed on the
stack, and a software delay
is executed Upon comple-
tion of this delay, the next
A/D reading is converted.
These two values are next
added together on the stack,
then placed into RAM, and
simultaneously displayed
on the video card.

The byte in RAM is the
same format as the byte on
the video card. In the black
and white format, the byte

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73 Magazine • November, 1984 19

contains two pixels of 4 bits
each. In the color format,
each byte of the displayed
picture has three bits for
each color plane except for
the blue color. Each time a
byte is loaded into the video
port, the hardware counter
is incremented by one value.
This places the DMA ad-
dress counter to the next
location in RAM where the
next pixel will be written,

Transmit Software. Fig. 7
contains a simplified exam-
ple of how an SSTV transmit
routine can be written This
example, like SSTV receive,

is very general and is pro-
vided only as an example to
allow for a guideline for de-
velopment of more complex
code.

The software starts off by
placing the picture con-
tained in memory onto the
display card. This is accom-
plished by a simple block
move of data to the display
card. Prior to the block
move, the card hardware
counter is reset to zero and
16K bytes are taken from
RAM and transferred to the
video card. Each time the
byte is stored at the video

Parts List

Display Board

0.1 ^F

IDs

10^F

8 U1-US

TMM2016or

6116 1

Variable cap, 9-35 pF

1 U9

74LS00

Crystal, 6.144 MHz

2 um

U11

74LS393

Crystal, 3.579545 MHz

2 U12,

U13

74LS244

2 UK

U15

74LS138

SSTV Modulator

1 U16

74LS244

IC XR2206

1 U17
1 U18
1 U19

74LS367

6845

744LS93

1
1

0.O33,iF Mylar™
0,01 pF Ceramic

1 U20

74LS245

Resistors

1 U21

74LS00

200 Ohms Va W, 5%

1 U22

74LS11

5.1k V4WP5%

1 U23

74LS367

10k % W, 5%

1 U24

74LS02

22k % W, 5%

1 U25

74LS00

39k Va W, 5%

1 U26

74125

47k V4 W, 5%

1 U27

74LS02

1k Trlmpot

1 U28

74LS05

5k Trimpot

1 U29

74LS374

50k Trimpot

1 U30

74LS157

1 U31

LM1886

SSTV Receive Interface

1 U32

LM1889

!C 1-4 MC1458

1 U33

9602

IC5 7414

Transistors

Resistors

2N3904

620 Ohms 1/4WT5%

Resistors

1 75 Ohms Va W, 5%

2 150 Va W, 5%

2 220 Vk W, 5%

2 470 Va W, 5%

1 510 V4W,5%

1 600 '/„ W\ 1 %

1 680 Va W, 5%

8 1k V* W, 5%

1 1.2k lttW.1%

1 2.4k Xq Wr 1 %

1 4,7k Va W, 5%

1 5.1k KtWt1°/o

2 5.1k V4W,5%

1 10k V4 W, 5%

2 50k Trimpot

Capacitors

3 43 pF Mica
2 100 pF Mica
1 1000 pF Mica
1 0.001 \JF

1 0.01 >jF

20 73 Magazine • November,

2 1.0k V4 W, 5%

1 2k % W, 5%
4 4.7k Va W, 5%
11 10k V* Wt 5%

3 15k Va W, 5%

2 18k Va Wt 5%
1 20k Va W, 5%

3 39k Va W, 5%
3 82k Va Wf 5%
1 220k Va W, 5%
1 4.7 M Va W, 5%
1 1k Trimpot

1 10k Trimpot

Capacitors

3 '0.0047 MF Mylar™

1 *0.01 j/F Mylar
6 *0,022 PF Mylar

2 '0.068 ^F Mylar
1 *25 ^F Mylar

Small Signal Diodes

8 *1N914
1 Or equivalent.

1984

card address, the hardware
automatical ly increments
the RAM address to the next
location.

The transmission process
starts off bv issuing a ver-
tical sync pulse. This pulse
allows for the receiver on
the other end of the trans-
mission path to reset the pic-
ture to the top of the screen.
In the following steps, a pic-
ture byte in memory is loaded
into the A accumulator,
Each nibble is formatted into
the lower nibble of a byte.
This byte is next used as an
offset to a lookup table in
memory which will convert
the address to an appropri-
ate digital signal which can
be transferred to the D/A
converter in the CoCo This
signal will then be trans-
ferred to a vco (variable fre-
quency oscillator or modu-
lator) which converts this
signal to a sinusoidal fre-
quency in the audio range.
This resultant signal is SSTV.

The program continues to
transmit pixels until 256 pix-
els are transmitted. At this
time a horizontal sync pulse
is transmitted. The program
next checks if 128 lines have
been transmitted. If so the
whole process is terminated.
If not, the program contin-
ues to transmit pixels.

CRT Controller Initializa-
tion, Fig. 8 contains a soft-
ware routine which will ini-
tialize the 6845. The routine
takes 16 bytes of data in the
table CONCRT and stuffs
them into the controller reg-
isters This process is ac-
complished by first present-
ing the controller register
number to the IC Next the
data byte is loaded into the
accumulator then trans-
ferred to the card.

The display constants in
CONCRT are for a standard
60-Hz display system. To
revise the formats to 50 Hz,
625 lines, registers 1 and 5
must be changed. The val-
ues should be selected by
trial and error

Hardware Construction

The hardware mentioned
above can be constructed

on prototype cards or as-
sembled from printed cir-
cuit boards. To assemble the
display interface on proto-
type cards takes a lot of
work and is vulnerable to
errors. Problems experienced
with prototyping the card
have included: grounds con-
ductors were too small, too
few bypass capacitors on
power lines, and hardware
counters U10 and U11 re-
quired a small capacitor on
the counter-reset line.
Despite these problems,
about 5 boards have been
constructed to date with ex-
cellent results.

Photo A shows the multi-
mode display board.1 This
interface is very compact
and its design is slightly dif-
ferent from the one shown in
Fig. 3. The board is attached
to the computer through a
short cable (see Photo B).

Photo C shows the orig-
inal prototype card con-
structed by K6AEP The card
was point-to-point solder-
wired on a prototype SS-50
computer interface card. A
small adapter card was con-
structed to plug into the
CoCo expansion interface,
(An etched PC board or
completely assembled ver-
sion of this card is available
from L. W, Interface.3

The SSTV receive and
transmit interfaces are avail-
able in a number of forms.
Photo D shows the multi-
mode receive-board inter-
face card; Photo E is a
transmit interface from
RTM Circuit Boards.2

All boards can be placed
in a cabinet with the appro-
priate power supplies of 5
volts (1 Amp) and ±12 volts
(100 mA). Cables can be
made to attach to the com-
puter and receivers.

Part II of this article will
describe the FAX hardware.

Conclusions

The computer approach
to displaying images is a
very cost-effective method.
Most alternative methods
available are limited in func-
tion and are considerably
more costly. The commer-

cial units have one advan-
tage in that they can be pur-
chased and plugged into the
wall and they are opera-
tional. The computerized
system described takes a lit-
tle more work, but it is ex-
tremely flexible and not sub-
ject to obsolescence as are
its commercial counterparts.
The results achieved with
the system described here
rivaled those of commercial
counterparts.

Photo F is a typical color
image, 128 pixels per line on
128 lines, 256 colors per pix-
el. Photo G is another color-
SSTV image which shows
the resolution of the display
board on facial flesh tones.
This type of image is the
hardest type to display. This
picture shows color con-
touring due to the 256 colors
per pixel Photo H is another
color picture with computer-
graphics overlays generated
by software. The picture is
the same as Photo G but re-
duced in size by one half.
The colored image was

Photo H. A color -SSTV picture with graphics. This picture is
the same as Photo Q hut reduced in size by software and
placed in the center of the /mage area The graphics were
generated by software and placed around the picture, The
graphics and picture were all generated by the K6AEP SSTV
7 A Revision 2 program.

moved to the center of the
display screen and graphical
characters of various colors

were distributed around the
picture.

Better results can be

achieved with 32K of dik-
play memory, but photos
were not presented in this
article for this mode. The
black and white images de-
veloped by this display den-
sity approach fast- scan TV
quality.

More photos will be pre-
sented in Part II of the arti-
cle, on the FAX application.

Obviously a project of
this magnitude is not a one-
person effort Some of the
people who contributed
were Ron Adair K5HFT of
Multimode Corporation,
Bob Blackstock WB5MRC
who helped with the display-
board design, Larry Fritz
AC80 of L. W. InterFace,
and Bob Wilson WB0RTM
of RTM Circuit Boards. ■

References

1 Multimode Corp., PO Box

171171, Arlington TX 76016;

(817^572^3996.

1 RTM Circuft Boards, 206 Efm

Street, Van Home IA 523460400.

* L W. InterFace, 9570 Kinsman

Road, Novelty OH 44072.

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73 Magazine * November, 19&4 21

DOCTOR DX

Work The World With No Antenna

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With Doctor DXf all you need is a Gommodore-64 computer, akey(orkeyer), and a TV set. There is no
need for an expensive transceiver, amplifier and antenna farm to enjoy the thrill of working "rare DX."
No more TVI or dead bands! Doctor DX is more than the most sophisticated CW trainer ever devel-
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Doctor DX simulates real H-R CW band conditions. All the stations you will work are generated by
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Radio population density, with 304 possible countries represented. The speed of stations operating in
the lower portion of the bands is much faster than those operating in the upper band segments. The
"operators" are also more polished in the lower portion of the bands-
Radio propagation (programmed for each band) represents what you would expect to hear on a
good propagation day at the peak of the sunspot cycle. The propagation follows the internal real-time
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fixes) are at distances you would expect to hear for the time of day and band selected.

You can learn and enhance your CW operating skills with Doctor DX. Doctor DX will not reward bad
habits. AEA even offers an awards program to owners of Doctor DX that work all zones, 100 countries,
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The Doctor DXCW trainer is a totally new concept in Amateur Radio. See what all the excitement is
about. Send for full details, and see your dealer for a demonstration.

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For information: (703) 643-1063 '

Stores hours: MWF: Noon-8PM

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in Virginia CALL TOLL FREE 800-572-4201

Send 3 stamps for a flyer. Dealer inquiries invited.

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AEA also has two on-going CW contests that you can enter with Doctor DX as your own schedule
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In addition to the two AEA contests, we are offering award certificates for achieving certain mile-
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AEA DrDXCC is achieved when you have worked 100 different countries, regardless of the frequen-
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Each award can be obtained by filling out a photocopy of the award application form (supplied)
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There is no need to ever be bored with your hobby again just because the bands are dead or you are
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Send 3 stamps for a flyer.

Dealer inquiries invited.

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Amateur Radio's
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24 73 Magazine * November, 1984

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PUBLIC
NOTICE

So you have three grand sitting there in
the shack, bui ham radio just isnH much
fun anymore? And your family would kill
you if they knew how much that gear
reallv cost? And vou love ham radio* but
somehow the old fire just isn't there
anymore? Is that what's troubling vou,

OM7

Remember how much fun it used to be?
The thrill of those first QSO's.1 And later,
the excitement of your first DX? But now
you have it all; the new rig. good
antennas, the upgraded license,
everything - everything except the old
thrills. You hoped that a new rig would
relight the fires, and it did, too. For a
week.

But remember those early QSO's? The
ones that sent shivers up and down your
spine? They were on CW, right? Sure,
you weren't very proficient at first. But
you got by, and you got better, too. But
CW always seemed like a lot of work, and
you couldnt wait to gel that upgraded
ticket and go on phone. Besides the old
J -38 key gave you a sore arm. But
somehow, after you made t he big move, it
was never the same again.
Maybe this is the time to go back to your
roots, back to the fun that you used to
have. On CW. Times have changed, you
know. J-38Ts and old bugs aren't state of
the an on the CWr scene anymore
Advanced keyers and sophisticated silky-
smooth Bencher paddles are where it*s at,
making CW the modern communication
mode that it is today.
A new keyer, a CW filter for the rig and a
Bencher paddle are the tools that you
need for modern CW. You will be
delighted and amazed how easily and
smoothly the letters flow from your
fingers. Practice for a few evenings, get
the feel of it, then slip into the novice
bands for a few QSO*s. They will be glad
to work you, and the practice will help
sharpen your skills. You will rediscovei
the thrills and satisfactions that made
ham radio such an important part of your
life. Try it. You'll be glad thai you did.

This message is brought to you by
Bencher, Inc, makers of the finest
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Lake Street. Chicago* Illinois 60606^\%2

73 Magazine • November, 1984 25

Bradley Wells KR7L
5053 37th Ave, SW
Seattle WA 98726

Wrap Up TV I

Can you endure another evening without transmitting?
Use this simple cure to choke out television interference forever.

One of the most per-
plexing problems for
the amateur can be TV I
complaints It seems that no
matter how clean your rig,
how little power you ra-
diate, or what operating
hours you choose, it is only a
matter of time before a TVI
problem comes home. The

best defense against these
complaints is the ability to
prove you are not ruining
your own TV reception. The
unfortunate fact of this de-
fense is that few of us can
boast of ''clean" TV recep-
tion while running our trans-
mitters.

After collecting some TVI

Photo A The TVI cure in place. The antenna coax and TV
power cord are wound in opposite directions through the
core to minimize coupling effects.

26 73 Magazine * November, 1984

complaints, most from my
own household, a solution
to the problem was sought.
The original attempt to cure
our own TVI problem was
the installation of cable TV.
This failed miserably and, in
fact, enhanced the sensitivi-
ty of both television sets to
my transmissions. How, with
the capability of jamming
every channel day or night,
an ultimatum was issued:
cure the problem or find an-
other hobby

Several solutions were
tried. The addition of high-
pass fi iters seemed to have
little effect on the interfer-
ence. A new grounding sys-
tem was installed utilizing
multiple copper rods with a

braided-copper ground strap
run to the rig. This lessened
the TVI but did not cure the
problem

Since my efforts were
proving less than effective,
current literature on TVI pre-
vention was avidly read dur-
ing my nonoperating time.
Despite being hooked up to
cable TV, the symptoms ap-
peared to be the result of
front-end overloading of the
TV receivers. Further reading
indicated the probability of
inductive coupling between
the TV coax and the trans-
mitter. In this case, rf cur-
rents are induced to flow in
the shield of a coaxial cable
situated near a transmitter
or antenna A high-pass filter

TO TV AKTERftft,
T£RM)HAL

ftQT WORE T*iAft 3-**
BETWEEN CHOKE &HQ TV

CORE FROM
COLOR TV
DEFLECTION
YOKE

«*Eft CORD #0uftO
i ft OPPOSITE piRECTlQft
TO vrwitrZE COURMMO

Fig. 7.

is of no use in this situation
since the rf current flows
down the shield of the coax,
through the filter casing,
and into the TV-
There are several possible
solutions One is to install a
quarter-wave stub at the an-
tenna terminals of the TV,
but this is effective for only
one operating frequency. A
better method is to use a
large ferrite toroidal core
and wind the coax around it
This functions as a shield
choke, preventing rf cur-
rents from flowing into the
TV, and is effective at all op-
erating frequencies. The on-
ly problem with this arrange-
ment is the cost of a suitable
ferrite core They are typical-
ly S10 00 to SI 5.00 apiece.

A less-expensive alterna-
tive was sought Remember-
ing that picture-tube deflec-
tion yokes have a toroidal
core, several were picked up
from a local TV repair shop
They were obtained free of
charge, being detective
units that had been re-
placed The copper wind-
ings were stripped off re-
vealing a large, bell-shaped
split core bound together
with a metal strap. The TV
coax was coiled around this
core in the same manner as
winding a toroidal trans-
former (Fig. 1). Three inches
of cable was left free for at-
tachment to the television.
This placed the homemade
choke as close as possible to

the TV antenna terminals
to minimize unwanted rf
pickup.

The results were truly grat-
ifying. With the transmitter
running at full power, only a
faint cross-hatching could
be discerned on the picture
Next the television power
cord was wound around the
ferrite core in the same man-
ner as the coaxial cable. At
this point, all symptoms of
interference vanished. Even
with one television oper-
ating a mere four feet from
the transmitter, the picture
and sound remained crystal
clear.

The same setup was tried
with the stereo system in an
attempt to achieve the same
spectacular results. The
speaker leads and the
power cord were wrapped
around the core in the same
manner as with the televi-
sion. Again it worked
beyond all expectations.
CQ CQ from KR7L' was
never heard on it again.

This system will not cure

every TV I or RFI problem
you might have. If your
transmitter is spewing out
harmonics or other spurious
radiation, you need to go to
work on the rig, not the tele-
vision. On the other hand,
this method will cure simple
overload problems and the
cost can't be beat. The TV
repair shops in my area were
more than happy to give

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away all their old, defective
deflection yokes.

Now when the neighbor
comes over to announce
that I'm pulverizing his TV, I
set him down in front of
mine while I fire up the rig. A
short demonstration results

in profuse apologies and a
willingness to listen to some
solutions. In addition, I can
rest assured that I am free to
operate when and where I
choose without disrupting
the family's favorite TV pro-
grams ■

Photo B. The ferrite core is removed from the deflection yoke
by releasing the metal restraining band or by cutting the
masking tape that holds it in place,

f See List of Advertisers on page 83

Photo C The correct method of coiling the TV coax through
the ferrite core.

73 Magazine * November. 1984 27

lohn P. Burke WD4S
1135 Nova Terrace
Tttusvitle Ft 32796

But I Know How To Solder!

Anyone can dribble hot metal over a joint, but it takes
an artist to really solder. Are you a Picasso or a pig?

Do you? Do you really
know how to solder?
We have all seen good and
bad soldering in commercial
products, from the small
battery-operated AM radios
and their atrocious work-
manship to high-quality and
reliable products both do-
mestic and foreign. Most of
the amateur-radio equip-
ment manufacturers have
rigid quality control which
ensures that you are getting
a good product

But how about you? Can
you duplicate their results
when you work on that
home project? And when if s
finished, do you stand back
and look at it with a feeling
of accomplishment or do
you say "good enough for

as long

government work;

as it works?

Then and Now

Lefs look at this process
of joining two pieces of met-
al together by the use of a
solder alloy, ifs one of the
oldest known joining tech-
niques and probably the
least understood by most
hams. Believe it or not it
was first developed in an-
cfent Egypt; the technology
has advanced to such a de-
gree today, however, that
even to mention its origin
would be like comparing the
first crystal set to the mod-
ern-day receiver.

Today, in the field of elec-
tronics, soldering is far from
the simple task it was in the

TIN /LEAD PERCENT AGE

WCJ

550* F
£ (288*0

£ 500* t
3 [£eO°Cl

% 45Q* F
£ (ZSZ'Cl
i-

400* F

590*f

WTf'Cl

(337*C>

Fig. 1. Fusion characteristics of tin/lead solders.

28 73 Magazine » November, 1984

early days of radio. It could
be considered a fine art and
one that requires experi-
ence, a thorough knowledge
of fundamentals, and great
care. Faulty solder joints still
remain the chief cause of
equipment failure.

What is presented here
will cover bask soldering for
electronics and certainly does
not represent the details
which should be covered for
one to become skilled, It
should provide you with
the fundamental knowledge
needed to perform soldering
operations with a fair degree
of reliability. It will cover
the fundamentals of solder
action, the selection and
proper use of the soldering
iron, and some clarifying
definitions. It will not cover
the accepted procedures for
soldering wires and compo-
nents to single-sided, dou-

Fig. 2. Types of cored solder,

with varying solder-flux per-
centages.

ble-sided, and multi-layer
circuit boards.

All aerospace contractors
have in-house training pro-
grams that are a certifica-
tion requirement imposed
on them by NASA These go
into great detail and are
quite lengthy. To cover
these related requirements
would fill a book, but the
average amateur has no use
for information on a "PWB
lapped termination, a PWB
stud termination, PWB
clinched termination, turret
terminal termination, or a
bifurcated terminal termina-
tion." This subject can get
very dry after about a week.
and just a little bit goes a
long way.

So, the key word here is

reliability High-reliability
soldering has been an an-
swer to early failures in
space equipment and the

60/40

II lilt h

II I 111

36IHF 37S-F
IB3-C 1*I*C

E3H

■-.I'JUiO

ITiC

F/g. 3. Plastic range of 60/40
solder: Melt begins at 361* F
and is complete at 375° F.

concept has spread to in-
clude aviation, weapons,
and medical equipment To-
day, we expect this reliabilh
ty in every-day electronics
as well, from your hand-held
to receivers with complicat-
ed bells and whistles.

General Considerations

In order to form a contin-
uous electrical path that will

ensure a good contact one

that vibration and mechani-
cal shock won't loosen and
will not be subject to oxida-
tion or corrosion, we must
solder it according to ac-
cepted standards. Look at
Fig. 1; it details the fusion
characteristics of tin/lead
solders, Notice the melting
point of lead and tin and
their different alloys. These
will be discussed later in
more detail.

The term ' 'soldering" gen-
erally means "soft soldering,"
which simply means a meth-
od of joining two metals to-
gether with an alloy of rela-
tively low melting point,
usually composed of tin and
lead

Common soft solder used
by aff of us at one time or
another comes in ribbon,
wire, and bar form, Wire sol-
der may be either solid or tu-
bular with a core (or cores)
of either acid or rosin solder-
ing flux. Bar solder is always
used with heavy irons or
with blow torches, plumb-
ing, and large sheet-metal
work. Ribbon and wire sol-
der are used with light irons
on electrical wiring and
other small jobs, as shown in
Fig. 2.

Solder is designated by
numbers; the first number
represents the proportion of
tin and the second number
the proportion of lead. 60/40
solder means a solder that
is composed of 60% by
weight of tin and 40% by
weight of lead. A common
solder for all-around use is
50/50 or "half and half."
There are others for a more
specialized use. Soft solders
for gold and silver and for
copper and brass sheet gen-

** See List of Aawrrtsms on page 36

erally contain more tin than
lead and melt at a low tem-
perature.

So-called liquid solders,
or "cold solders," usually
are not solders at all but are
cements or glues fortified
with aluminum or other me-
tallic powder. Avoid trying
to make a metal-to-metal
bond with these products.
They are not electrically
conductive and they may
disintegrate in the presence
of organic solvents or at
temperatures considerably
below the softening point of
tin and lead solders.

The Need for Fluxes

What does the applica-
tion of flux do? Why do we
need to apply flux to a sur-
face to be soldered? In order
for the solder to adhere to
the metals to be joined, the
surfaces must be complete-
ly free of oxide. Oxides are
present on most metals;
they form at room tempera-
tures but almost immediate-
ly when heated, A coating or
some material must be used
that will remove the film al-
ready present and protect
the solder and the metal
from further oxidation. Such
a material is flux. It is a Latin
word, and it means "to
flow."

Except for electrical
work, the fluxes most com-
monly used for soft solder-
ing are solutions of pastes
that contain zinc chloride or
a mixture of zinc and ammo-
nium chlorides The heat of
the soldering operation
evaporates the medium con-
taining the chloride flux.
The flux then melts and par-
tially decomposes with the
liberation of hydrochloric
acid which dissolves the ox-
ides from metal surfaces.
The fused flux also forms a
protective film that prevents
further oxidation. These
fluxes are called "acid
fluxes" and come in both
liquid and paste form.

It goes without saying
that acid fluxes have a cor-
rosive action and most cer-
tainly should not be used to

solder electrical connections.
On printed circuit boards —
and if it is necessary to wipe
the surface with flux prior to
soldering — it would certain*
ly be wise to use a good
grade of flux and one that
can be removed completely.

Some assembly proce-
dures recommend that all
solder pads be wiped with a
coat of flux This is a bad
practice, ft is hard enough to
remove the last traces of ex-
cessive flux and its residue
without damaging the print-
ed circuit board or the in-
stalled components. If there
is adjacent wiring attached,
there is always the danger of
rosin flux wicking into the
wire between the conductor
and the insulation, which
would not be removed when
the board is cleaned.

Always use a good grade
of solvent to remove the un-
wanted flux and its residue.
Ethyl alcohol, isopropyl
alcohol, trichorotrif luoro-
ethane, or tricholoethane
can be used. A mixture of

Quick charge cordless
soldering iron, up to 125
electronics joints per

charge. Total recharge
in less than 4 hours.
Isolated tip design. One
of more than 2 dozen
ISO-tip and ORYX irons
available, write for free
catalog and name of
nearest distributor,

AHOtTip

Cordless
Soldering

about 90% isopropyl al-
cohol and 10% naphtha is
excellent for most work.

An acid brush with about
half of the bristles cut away
makes an effective tool to
remove the flux and residue.
Rub gently but firmly, taking
care not to press too hard,
until all traces of the flux are
removed. In some cases the
joint can be polished using
several thicknesses of
Kleenex,

Solder

Rosin core solder, when
heated to its melting point,
undergoes several changes
which should be noted in
order to make a good joint
It is solid to begin with,
changes to a plastic, and
then changes to a liquid
form Pure tin melts at about
450° F and lead at 621° F It
would seem that a 50/50 al-
loy would therefore become
liquid at about 535° F. Not
so 50/50 is a solid until it
reaches a temperature of
about 361° F. At this point it

Mo. 7700

QUICK CHARGE

Cordless

Soldering Iron

ORYX

WAHL CUPPER CORPORATION

Sterling. Illinois 61081 ■ (815) 625-6525

^310

73 Magazine • November. 1984 29

I CI (D

X o

P31NT

G£V£i POlhT

THE WETTING ACTION

SOLDER

TiNfiEO ON fi£VE

•x

S£tll- CHISEL PfrnT

BEVEL ED -COItt «H«T

CHISEL -CQHE POWT

COKE POINT

Fig 4. Tip types.

becomes plastic and re-
mains in this condition until
it reaches 41 5Q F when it be-
comes liquid.

Let's take 60/40 (see Fig
3). At 361° F, 60/40 changes
from a solid to a plastic and
remains in that state until
375° F when it turns into a
liquid. The time that 60/40
remains in a plastic form is
considerably less than the
50/50. If the joint is moved
while the solder is in a plas-
tic state, it could well be de-
scribed as a disturbed joint
It might check out with your
meter, but when an electri-
cal load was applied, it could
fail to conduct

Lefs take another case:
63/37 alloy. This is what is
called an eutectic (low melt)
composition, It is 63% tin
and 37% lead, It has no
plastic state and is trans-
formed from a solid to a liq-
uid at 361 ° F. 63/37 is most
generally used on printed
circuit boards. It can be seen
that this would have an ad-
vantage since the plastic
state does not occur Also,
the importance of the sol-
dering-iron tip temperature
suddenly takes on a new
meaning.

Heat Sources and Tinning

A temperature-regulated
soldering iron is a must
when soldering printed cir-
cuit boards. A 50-Watt iron
can easily be regulated with
a variac or a homemade
voltage regulator using a
tight-dimming rheostat The
temperature can be adjust-
ed to suit the need of the
joint to be soldered. The
larger the mass, the more
temperature will be re-
quired. Start with a low tem-
perature and gradually in-

crease it until the desired re-
sult is achieved.

The geometric shape of
the soldering tip controls
the rate of heat flow to the
extreme point of the solder-
ing tip. Two main considera-
tions should be made in
choosing a proper tip point:
access to the solder joint
and maximum wetted con-
tact of the tip point with the
joint members to be sol-
dered. Because of high com-
ponent density, one often is
restricted to just one or two
shapes. The standard solder-
ing tips are shown in Fig, 4,

Lefs look at Fig. 5 and con-
sider that word "wetted/'
Wetting is the flow and ad-
hesion of a liquid to a solid
surface. It is characterized
by smooth, even edges In
other words, a tip that is hot
and tinned and ready to do
its job. Conversely, de-wet-
ting is a condition in a sol-
dered area in which the liq-
uid solder has not adhered
intimately to the joint or, in
this case, the solder tip,

Selected tinning (Fig. 6) is
an important consideration
in certain soldering opera-
tions and the point should
be tinned on one side only.
There is a good reason for
this: There is less chance of
disturbing an adjacent joint
with the immunized side of
the tip's point When a sol-
dering iron is removed from
its holder, the soldering tip
should be cleaned on a wet
sulfur-free cellulose sponge.
The wet sponge will provide
a thermal shock to break
free and remove secondary
oxides from the surface of
the tip

A tip will de-tin or de-wet
and degradation (or the start

30 73 Magazine • November, 1984

COPPER

LEAt

CONCAVf
FILLET

5OL0EH
FEATHERS
OUT to £
I KiN LDQE

Fig. 5. Molten solder dis-
solves and penetrates a clean
copper surface forming an
intermetallic bond

of oxidation) of the tinned
areas will start when the sol
der begins to ball up on the
tip. Once this action has start-
ed, it usually will continue
until the tip will no long-
er wet with fresh solder and
makes a dry contact with
the work. Then the operator
will believe the iron is not
hot enough. This can all be
avoided if the tip is tinned
after each soldering opera-
tion and prior to placing the
iron in its holder.

Another cause of de-tin-
ning is an excessively high
tip-idling temperature at
which the solder oxidizes
faster than you are able to
replenish the tip with fresh
solder. At high temperatures
the flux usually burns and
carbonizes, further adding
to the de-tinning of the tip.
Two simple axioms should
be remembered:

1) Solder at the lowest
practical temperature, and

2) Keep your soldering tip
tinned.

Stranded wires may be
tinned very simply if you
keep in mind the mass they
present to the soldering iron,
In other words, the larger
the wire, the larger the sol-
dering iron. For example,
suppose we wanted to tin a
22-gauge wire and a 14-
gauge wire. Both could be
handled the same way, with
a couple of exceptions, A
small, 25-Watt iron with a
tip temperature of about
500° F would be sufficient
for the smaller wire. How-

■■e : :-:

Fig. 6. Selected tinning.

everp in order to tin the larg-
er wire, an iron of at least
100 Watts should be used
but with the same tip tem-
perature.

To tin, place a drop of sol-
der on the tip, place the wire
in the solder, and add solder
to the top of the wire so that
it sweats completely and
through the strands. Move
the wire slowly along the
length to be tinned while
adding solder constantly un-
til the strands are thorough-
ly wet with solder

Another way to tin wires
is called the "reflow" meth-
od. Tin your wire in the usu-
al way and note if it has sur-
plus of solder on the wire
and separate strands cannot
be distinguished. Reflow
can be accomplished by
raising the iron temperature
considerably, then dipping
the soldered portion of the
wire into flux (a good grade
of rosin flux) while wiping
the tip rapidly on a wet
sponge to shock off the ox-
ides. Very quickly hold the
wire in a vertical position
and place the tip of the wire
on the soldering-iron tip
The excess solder will be re-
moved and will flow to the
soldering-iron tip, and the
wire strands will be visible.
The wire will be thoroughly
tinned and will not "bird-
cage" when bent.

A Word to the Wise

Use a thermal shunt or a
heat sink whenever install-
ing heat-sensitive compo-
nents like transistors, flat
paks, or integrated circuits.
It is very easy to damage
these items with excessive
heat When trimming tran-
sistor leads for installation
on your favorite PC boards,
grip the lead to be cut with
needle-nose pliers between
the transistor case and the

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73 Magazine * November, 1964 31

point where you cut The en-
ergy that makes the unused
end go flying across the
room can also be expanded
in the opposite direction
and can fracture the con-
nection inside the housing
easily scratch one tran-
sistor.

Definitions

Cold solder joint: An unsat-
isfactory connection result-
ing from de-wetting or
movement of the conductor
during cooling. Also caused
by too rapid cooling (like
dousing it in water) These
joints usually appear frosty
and granular. They will show
up as an intermittent when
you least expect it and will
drive you up the wall. When
checked with your trusty
meter, they show good con-
tinuity, but when an electri-
cal load is applied, things will
change from time to time,

Plated-through hole (PTH):
An interesting thing to look
for on printed circuit

boards. This is a
through hole formed by the
deposition of metal on the
inside surface of the hole,
(Also known as a supported
hole.) It is used to provide
additional mechanical
strength to a soldered termi-
nation and/or to provide an
electrical interconnection
on a multilayered printed
wiring board. Use extreme
care whenever removing a
component from one of
these. You could loosen it
up on one side and it would
still be solid on the other
side. It is best to use solder
wick here or a solder sucker
and remove all the solder.

Rosin solder joint: A connec-
tion with entrapped rosin
flux. The only recourse is to
re-solder— carefully.

Solder icicle: Most generally

noted on small imported
hand radios. It is a cone-
shaped peak or sharp point
of solder usually formed by
the premature cooling and
solidification of solder upon

removal of the heat source.
High-speed production
causes this unsatisfactory
condition If the operator
worked that fast, it makes
one wonder what other bad
practices he was guilty of
Be suspicious of the whole
unit if this is noted

Things to Remember

• Flux is very corrosive at
solder-melting tempera-
tures, which accounts for its
ability to remove oxides. If
you must use flux, use a t *
good grade Kester No. 1544 p
is a good grade for afmosr* c
all electrical and electronic
soldering,

• Vary the voltage input to
your soldering iron and there-
by control the tip tempera-
ture. Also choose a solder-
ing iron that is matched to
the thermal mass you wish
to solder. Light work, light
iron; heavy work, large iron

• If the iron tip is too large
for the work and too hot the
heating rate will be so fast
that it cannot be controlled.

If the tip is too small the
heating rate will be too slow,
A good rule to prevent over-
heating rs to get in and out as
fast as you can. This simply
means using the hottest iron
you can react to, or one giv-
ing about a two-second con-
tact on the joint being sol-
dered. Caution: Too much
heat, too much pressure, too
many times on a printed cir-
cuit board — even on the
very best board — will lift
the pad.
► Always remove the flux
nd other impurities. Keep it
clean, clean. . clean!
• Finally, some soldering
irons are simply not compat-
ible with transistors and in-
tegrated circuits. They are
not isolated from ground
and can easily zap every-
thing you solder. Choose
well

I would like to acknowl-
edge the encouragement
and help of Merv Holm berg
KQ1C. His constructive
comments and enthusiasm
made research a pleasure, ■

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32 73 Magazine • November, 1984

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Free-Form Filter Design

Build the ultimate audio filter: high-pass, low-pass, bandpass,
notch, variable Q and cutoff frequency, all in a single circuit

Circuit? Sorry, that's single chip/

Jonathan A, Titus KA4QVK
PO Box 242
Biacksburg VA 24060

Many hams use filters
to block interfering
signals so that CW, phone,
and RTTY transmissions can
be copied better. Crystal fil-
ters are used in many mod-
ern transceivers in i-f stages,
and add-on audio filters are
available from many manu-
facturers. Most audio filters
don't vary much in their de-
sign, using operational am-
plifiers (op amps), resistors,
and capacitors to put to-
gether active-filter building
blocks. These have been de-
scribed in many publica-
tions, and a typical filter ts
shown in Fig. 1. Common au-
dio filters are low-pass, high-
pass, bandpass, and notch.
See Fig. 2 for typical frequen-
cy response curves.

Circuits are available if

you want to build your own
filter Articles in 73t QST,
and other ham magazines as
well as sections in The Ra-
dio Amateur's Handbook
provide circuit details.1'
Most of the parts are inex-
pensive and readily avail*
able, but if you want to look
at off-the-shelf filters, they
are available from many
manufacturers. The MFj-720
is a typical bandpass filter
centered at about 750-800
Hz. Standard filter circuits
can be duplicated, and by
using several filter stages in
series, you can get a fairly
narrow bandwidth You also
can buy a filter such as the
M and M Electronics MSB-1,
which contains all of the fil-

0 001

.; ooi

OUT

Fig. 7. A typical op-amp bandpass filter for 750-800 Hz.
34 73 Magazine • November, 1984

ter types. Even more com-
plex and expensive filters,
such as the Datong frequen-
cy-agile audio filter, are
available.

Integrated-Circuit Filters

If you decide to build
your own filter circuits, you
might consider using the
AF-100 integrated circuit
from National Semiconduc-
tor. This "chip" contains
three op amps preset in a ba-
sic filter circuit By adding a
few external components,
bandpass, low-pass, and
high-pass filters can be built
A "spare" op amp in the
chip is used if you want to
build a notch filter Filters
are easy to set up; a few cal-
culations are needed to se-
lect the right combination
of resistors and capacitors,
but the math is simple
There is a 20-page data sheet

I LOW- PASS

AMPL

A H P I

HIGH -?f> .

FREQ

FKEQ

available that explains the
types of filter functions that
can be obtained, and several
examples show how to use
this filter chip. There is also
an AF-150 universal wide-
band active filter and an
AF-151 dual universal filter

One of the limitations of
most of the standard fil-
ters is that you can't easi-
ly change the cutoff fre-
quency once the filter has
been built For example, in
a filter with four op amps,
you would need to carefully
vary at least four resistors
to change the cutoff fre-
quency.

By the way, the term cut-
off frequency is used a bit
loosely, since low-pass and
high-pass filters have a cut-
off frequency, while notch
and bandpass filters have a
center frequency. Since it's
cumbersome to say both.

bAMfj-PASS

AfclPL

i hi. ;j

AMPL

NOTCH

FREQ

Fig, 2. Frequency response curves for standard filters.

tefs use cutoff frequency,
since ifs fairly standard

If a CW signal is being
masked by one at a slightly
higher audio frequency, you
may be able to shift the in-
terfering signal a bit higher
and then use a bandpass fil-
ter to add further selectivity
to the signal you are copy-
ing. If the cutoff frequency
of your filter is fixed, this
type of adjustment may be
difficult Many less expen-
sive filters have a fixed cut-
off frequency, while some
of the more expensive ones,
such as the M and M Elec-
tronics MSB-1, use ganged
potentiometers so that the
center frequency can be var-
ied. Ganged pots get to be
expensive, so designs are
generally limited to two
pots operated by the same
knob. Since ganged poten-
tiometers don't always track
one another perfectly, filter
performance is affected.

The Bencher XZ-2 band-
pass filter has a variable cut-
off frequency, but ganged
pots are not used. A single
potentiometer controls sev-
eral transistors that act as
variable resistors in the indi-
vidual filter stages. This al-
lows the center frequency to
be changed rather easily,
and It seems to be a reason-
able solution to the mechan-
ical problems of ganged po-
tentiometers.

CW Regenerators

A CW regenerator is a
fairly simple circuit in which
a phase-locked loop (PLL) or
other tone-detecting circuit
is used to pick out a narrow
frequency band* Since the
output of the PLL is a logic
signal indicating tone or no
tone, the CW signal being re-
ceived is tuned so that the
PLL "follows" it An LED on
the output provides a visual
signal that can be used to
show you when the PLL is
accurately tracking the CW
signal you are hearing. The
output of the PLL is used to
trigger an oscillator, and this
tone is heard in a headset or
on a speaker

The net effect is to "re-

construct" the signal by hav-
ing a narrow tone band-
width detected and using
this to generate a perfect
tone for the listener, A CW
regenerating unit called the
Amcoder was available
from AMC Engineering a
few years ago, and a block
diagram of this unit is shown
in Fig. 3. Since PLL circuits
are sensitive to the ampli-
tude of the input signal, an
age stage between the re-
ceiver audio output and the
PLL input is recommended

Another CW regeneration
circuit was described in
QSTJ This makes use of an
"envelope detector" that
demodulates the CW tones
and triggers an oscillator to
regenerate a perfect tone.
This circuit also incorpo-
rates a delay so that noise
spikes do not trigger the
tone oscillator.

Many other types of
filters — LCr RC, acoustic,
etc. — have been described
by amateurs and profession-
als.*

Swttched-Capacttor Fillers

During the last year or so,
a new type of filter inte-
grated circuit has come on
the market. This is called the
switched-capachor filter, or
SCF, and several types are
available. Among the easi-
est to use is the National
Semiconductor MF-10 SCF**
It costs about $3.00 and can
be set up easily to perform
any of the four filter opera-
tions. No external capaci-
tors are needed, and only a
few external resistors are
used. There are two filter cir-
cuits in each MF-10 inte-
grated circuit. Without go-
ing into the theory of opera-
tion, I'll just tell you that the
cutoff frequency of the
MF-10 filter chip is set by us-
ing an external clock. The
clock frequency is selected
to be either 100 or 50 times
that of the cutoff frequency
of the filter you are design-
ing. The 100/50 ratio is pre-
set at one pin on the MF-10
chip. Since this is just a log-
ic-state input, it provides an
easy way to change the

AUTOMATIC
LEVEL

CONTROL

(» 'LOCK

TO'
DETECTOR

JU — 1

TfllOGER

TONE
OSCILLATOR

OUTPUT

FREOUEWC*
ADJUST

Fig. 3. Block diagram of a CW regenerator,

range of the filter. Either a
CMOS- or a TTL-compatible
clock signal may be used,

If you want to use the
MF-10, you can set it up for a
particular type of filter and
vary the cutoff frequency of
the filter by varying the
clock frequency. One prob-
lem with all SCF circuits is
that a small amount of
clock signal is superimposed
on the audio signal being fil-
tered. However since the
clock frequency is so much
higher than the audio signal,
one, you won't be able to
hear it, and twor it's easy to
put a simple RC low-pass fil-
ter in the final audio output
circuit to remove most of it
A typical fourth-order, 1-kHz
low-pass filter is shown in
Fig. 4.

In this circuit, both filter
circuits in the SCf (hip (each
of which is a second-order
filter) have been used in se-
ries. Using a common clock
frequency for all of the filter
stages lets you easily change
the center frequency of the
filters, and they all track one
another without significant
errors. Additional informa-
tion about the MF-10 is
found in the 12-page data
sheet for this device.

Two other SCF devices
are the Motorola MO 4541 4
dual tunable low-pass filter

and the MCI 45433 notch fil-

ter.1*" These devices were
designed for use primarily in
data communications equip-
ment and modems, but th^y
can be adapted for amateur
use. They are a bit expen-
sive, in the $10 to $20 range.

The Reticon R5620

I have found that the
most interesting SCF is the
R562G, manufactured by EC
& C Reticon and available
for about $7.50. This filter
has built-in high-pass, band-
pass, notch, and low-pass
operations, and no external
filter components are need-
ed. All of the filtering is
done on the chip with built-
in circuitry. The EC & G Reti-
con Company manufactures
linear photodetector arrays

> * I*

t t *++m

-1

:Ci

lOQKHJ

•

v •

9 I* I*

i >i

R4
Vk*V-

Fig. 4. Using an MF-10 filter
chip for a 1000-Hz, fourth-or-
der, low-pass filter.

VL+9V1

GND

VH-%VJ

GNi __
IN*

■Q

J" -k- Jl.

BW20

h* fo ht 1-? |« Is |* U 1?

F0& Q4 00

. ' *- ^ '

5ICNAL OtJTPUt

CLOCK IKPUT
100 » ITTL)

FHEOUEWO*
CONTROL

CONTROL

DIGITAL CONTROL INPUTS -
TTL - COMPATIBLE

Fig. 5. Pin configuration of the Reticon R5620 SCF chip.

73 Magazine • November, 1984 35

Fig. 6, Response curves for the Reticon R5620 used as a band-
pass filter.

and x-y photodetector ar-
rays that are used in solid-
state TV cameras. They also
produce very complex and
expensive fitter devices for
special signal-processing ap-
plications.

In a filter circuit that uses
the R562Q, the cutoff fre
quency and its Q are inde-
pendently set by providing
five binary (logic 1, logic 0)
inputs for each function.
This means that there are 32

Frequency

Clock Frequency

Cutoff Frequency

Binary Code

Cutoff Frequency

for 100-k Hz Clock

F04 ,

FO0

0 0 0 0 0

200.0

500 Hz

0 0 0 0

191.3

523

0 0

182.9

547

0 0

174.9

572

0 0

167.2

598

0 0

159,9

625

0 0

152.9

654

0 0

146.2

684

0 1

0 0 0

139.8

715

0 1

0 0

133.7

748

0 1

127,9

782

0 1

122.3

818

0 1

116 9

855

0 1

111.8

894

0 1

106.9

935

0 1

102.3

978

1 0

97.8

1022

1 0

93.5

1070

1 0 0

89.4

1118

1 0

85.5

1169

1 0

81.8

1222

1 0

78.2

1279

1 0

74,8

1337

1 0

71.5

1399

1 1

68.4

1462

1 1

65.4

1529

1 1

62,5

1600

1 1

59.8

1672

1 1

57.2

1748

1 1

54.8

1825

1 1

52.3

1912

1 1

50.0

2000 Hz

Table 7. Binary frequency-control codes. Frequencies are for
a IQQ-kHz clock signal.

Filter Action

Low-pass
High*pass
Bandpass
Notch

LPin

Signal
GNO
GND
Signal

HPIn

GND

Signal

GND

Signal

BPin

GND

Signal

GND

independent settings tor
each one. Any one of the
four filter actions can be se-
lected. Except for a few re-
sistors on signal inputs, no
other external components
are required. A pin configu-
ration diagram of this chip is
shown in Fig 5. This chip us-
es a split +9-volt power
supply and an external
clock signal. The clock sig-
nal can be TTL-compatible,
but it is also easy to build a
clock circuit that will run
from the +9-volt power
supply.

The center frequency of
the R5620 filter can be
changed by changing the
clock frequency or by
changing a 5-bit binary code
applied as logic levels to
five pins on the R5620 chip.
It is this set of digital inputs
that gives the R5620 a great
deal of flexibility The five
digital inputs are tabled
FO4-FO0 and they are
shown in Table 1. The clock

Q Binary Code

04 . Q0
0 0 0 0 0
0 0 0 0 1
0 0 0 10
0 0 0 11
0 0 10 0
0 0 10 1
0 0 110
0 0 111
0 10 0 0
0 10 0 1
0 10 10
0 10 11
0 110 0
0 110 1
0 1110
0 1111
10 0 0 0
10 0 0 1
10 0 10
10 0 11
10 10 0
10 10 1
10 110
10 111
110 0 0
110 0 1
110 10
10 11

110 0
0 1

1 1

11110

11111

0.57
0.65
0,71
0.79
0,87
0.95
1.05
1.20
1.35
1.65
1.95
2-20
2.50
3.00
3.50
4.25
5.00
5.80
7.20
8.70
10,0
11J
13.0
15.0
17.5
19.0
23.0
28.0
35.0
40.0
80.0
150

Table 3. Signal input connections for different filter actions,

36 73 Magazine • November, 1984

Table 2. Binary Q-control
codes.

rate is listed as the ratio of
the cutoff frequency to the
clock frequency The con-
trol inputs are simply pro-
vided as a 5-bit straight-bina-
ry code. Let's look at an ex-
ample. Well assume that a
100-kHz clock signal is used
and that the ratio of 102.3
has been chosen by setting
FO4-FO0 to 01111. The fil-
ter's cutoff frequency is 978
Hz.

If the 100-kHz clock sig-
nal is used, the filter's cutoff
frequency can be varied
from 500 Hz to 2 kHz by
varying the 5-bit binary code
on frequency-control lines
FO0-FO4 between 00000
and 11111. The 32 frequen-
cy steps are logarithmic,
which simply means that the
frequency ratios are fairly
evenr about 4 to 5% per
step.

The alternate approach is
to preset the 5-bit frequency
code for the R5620 at about
its mid-frequency setting
(10000) and then vary the
frequency of the clock sig-
nal controlling the filter
Without careful clock-cir-
cuit design, this can present
problems Many home-brew
clock circuits spread out the
low frequencies on one side
of the frequency-controlling
potentiometer, but high fre-
quencies are "scrunched" at
the other side. Using a fixed
clock frequency and chang-
ing the 5-bit control input
seems the better method of
frequency control.

The Q of the filter also
can be varied by using the
five digital inputs labeled
Q4-Q0. As shown in Table 2r
the Q can be varied from
0.57 to 1 50. That's right, 1 50!
Of course, you're not going
to get much useful informa-
tion through a bandpass fil-
ter with this high a Q, but in
between 150 and 0*57 there
is a lot of useful filter power
Typical bandpass response
curves are shown in Figure 6.

The R5620 has three sig-
nal inputs, LPin, HPin, and

BPin, and by connecting the
audio signal to be filtered to
one of these, the appropri-

Now, turn the AIR-1 program loose
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Use your old favorite T.U., or experiment with new designs,

The AIRDISK makes it happen, with all the features of the AIR-1 program on

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Uses the AIR-1 style RTTY cross hatch on screen tuning in-
dicator that has become so popular for perfect tuned copy
without taking your eyes off the video or use whatever
scheme your present T.U. has. "Red Dot" and regenerated
audio pitch reference tone for easy CW tuning*

Choice of full- or split-screen with large type- ahead text
buffer and user selectable color display.

ID and programmable memories that save to disk and
auto-load at start-up to get you on the air quick.

VIC-20 and C-64 program on the same disk. (VIC rcq. lb'K)

Keyword or manual control of Commodore serial printers*

Receive text saves to RAM and disk for real-time RX/TX
from disk.

Separate CW, FSK, PTT keying output lines from the
computer.

Three uncommitted TTL logic outputs that are controlled
by the receipt of a user programmable keyword*

Independent normal /invert control from the keyboard

for receive and transmit means compatibility with
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• Full speed operation: transmit and receive Morse 5 to
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110 & 300 baud.

• Four mode AMTOR: Mode A (CHIRP), Mode B (FEC)
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AIRDISK for both C-64 and VIC-20 $39.95. For
those who want a complete T.U. with software in
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Microlog Corporation, 18713 Moonev Drive*

Caithersburg. MD 20879 Tel: -301*258*8400

MICROLOG

** Sm List of Advertisers on page 68

INNOVATORS IN DIGITAL COMMUNICATION

Note: VtC-20 is a trm it-mark of Commodate Electronics, Ltd.
Copyright I 1984 Micro) op Corporation

73 Magazine • November, 1984

*9v

rvn

TO *S¥ ClflCUlT$

:■

KUF

:*oopt

DAT* gas

-J I1 J la110

F/g. 7. Using an 8-bit ADC0804 A/D converter as a knob en-
coder

ate filtering is done, When
the notch filter is to be used,
the audio signal is routed to
both the LPin and the HPin
inputs. The chart in Table 3
shows how the signals are
connected. There are other
combinations of these three
inputs, but they are not use-
ful for filtering.

Since the R5620 has a
0-dB insertion loss, no exter-
nal signal amplification or
attenuation is needed. How-

ever, if you want to use this
filter between your receiver
and headphones or a speak-
er, an audio output amplifi-
er is recommended. There
are many of these in inte-
grated-circuit formp and they
are easy to use

The R5620 filter circuits
can be cascaded, and you
can control each one sepa-
rately or you can use paral-
lel digital inputs and control
them simultaneously. The

AUDIO
SIGNAL -i
INPUT

L V J

4 TOO

$m r 'srrons

4700

i
4.

LOW -PASS

HIGH -PASS
BAND- PASS
NOTCH

TO LP INPUT TO HP INPUT TO §P JNPyT

i-POLE. 4- POSITION RtHAfiV SWllCH

f/g. & Schematic diagram of the filter control switch.

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next question is how to get a
5-bit binary code.

Digital Filter Control

One of the obvious ways
to generate the 5-bit code is
by using a series of five
on/off or logic 1 /logic 0
switches. This may be fine
for testing, but for on-the-air
use, if s impractical. Thumb-
wheel or rotary switches
provide an alternate, but
most of these are limited to
12 or 16 positions. There are
lots of 40-position binary-
coded rotary switches avail-
able from old 40-channeI CB
units, but these use an odd
type of binary code, so they
can't be used easily to gen-
erate the required 5-bit
straight-binary code.

A solution that isn't as ob-
vious is to use an analog-to-
digital (A/D) converter to
generate the binary codes
that are needed An A/D
converter has a minimum
and a maximum voltage
range, and when an "un-
known" voltage is within the
range, the converter will
provide you with a binary
code that represents the un-
known voltage. Thus, for an
8-bit converter the range of
measurable voltages might
be between 0 and 5 volts,
with the binary outputs
being 00000000 up to
11111111 Computers and
other digital devices use A/D

OQ47^p

tOK

* •

^i.U -9V

* *

IOO0

_vi = =

-r::

1 1

T *7O0

wy4

1 000

?B05

[power
9 > »3v( to other

555

"A^ 4 i v

ft?

Z 4

(circuits

00i

fTT

3000 .

(ADJUST CLOCK FOR ^T" *
ABOUT lOOitHO fa

Fig, 9. Schematic diagram of the complete filter circuit.

73 Magazine ■ November, 1984

converters to measure un-
known voltages.

The National Semicon-
ductor ADC0804 8-btt A/D
converter was chosen be-
cause it ts easy to use, readi-
ly available, and inexpen-
sive. It is used in a free-run-
ning mode, so that conver-
sions are done one right af-
ter the other. A potentiom-
eter is used to provide the
voltage input and the A/D
converter provides an &-bit
straight-binary output as
shown in Fig. 7.

This circuit provides an
ft-bit output that goes from
00000000 up to 11111111,
from one side of the pot to
the other The function is
the same as that of a
256-position binary-coded ro-
tary switch. Not bad for
about $4 00, Since only five
bits are needed, the most-
significant five bits, D7-D3,
are used The other three
bits, D2-D0, are not used.
This arrangement provides
for 32 binary codes, linearly
spaced across the range
of the potentiometer. The
ADC0804 chip has a fairly
low input impedance, so
a low-value potentiometer
must be used to provide the
unknown voltage that is to
be converted into a binary
code.

A rotary switch with four
positions and three poles is
used to route the input au-
dio signal to the correct in-
puts for the four filter ac-
tions. This is shown in Fig. 8.

A complete filter circuit is
shown in Fig. 9. You can cas-
cade as many of these
stages as you want to and
put them together in various
combinations. For example,
you might have two filters in
series. Both could be set up
for low-pass operation, pro-
viding a fourth-order low-
pass filter. Or you could set
one for low-pass operation
and the other for notch op-
eration Of course, the au-
dio output amplifier is only
needed at the end of the fil-
ter chain.

Using the Filter
There are many uses for a

■The

HAM SHACK

220 N. FULTON
Evans ville, IN *t 7710'^
812-422-0231 j

81 2-422-0252

WaiterCort*

CALL FOR PRICES

ALA

Prices and Availability Subject to Change

ENCOMM (SANTEC)

CP-1 /6^i or Vic 20 Software Package
MP-&^ Interface Package ......

T^4 Isopole Antena . , .

MBA -TOR Software * *

Sq- Ft.) Rotator
Elevation Rotator

ALLIANCE
HQ-73 (10*7
tl-110 Small

ASTRO N

RS7A 5-7 Amp Power Supply . .
RSlOA 5-10 Amp Power Supply .
RSI2A 9-12 Amp Power Supply .
RS20A 16-20 Arcp Power Supply.
RS2QM 16-20 Amp W/MeteC
RS35A 25-35 Anp . . ,
&S35 25-35 Amp u/Meter.
RS50A 37-50 Amp . . .
K5 50M 37-50 Amp W/Meter

BENCHER

By-1 Paddle ......

ZA-1A Balun , . ■ ■ i. .
BUTTERNUT

HF6-V 80-1 0M Vertical -
2MCV-5 2 Htr * . . . -

CONNECT SYST EM

Private Patch

CUSHCRAFT

A3 Tr? bander 3 EL

M Tribander ^ EL * * . , -
2\bB/2]b?E Boomers 14 EL 2H
32-19 Super Boomers 1 9EL 2H
AR!(-2& Rtngo Ranker . . •
A0P-1 Oscar Package * . .

Of AW A

CN-520 1.8-60 Mhz Swr/Pwr Mtr , .-
CN-620B KS-150 Mh£ Swr/Pwr Mgr .
CN-&30 1J+D-150 Khz Swr/Pwr Htr
CS-201 Max. Freq; 500 Mhz 2 Pos.Sw

I I (Works Great)

$239*00
129,00

i+5.00
99*00

$109.00

$ 49.00
59-00
69.00

89. 00
109.00
135.00

149,00
1 99 ■ 00
225.OO

$ 39-00

19.00

$125.00
k 5. 00

$%19,Q0

211

HAL
Cfti

UP 2 Htr

UP 220 MHz

UP 4^0 Mhz

Call for Accessories

1Q0/CRL 200 Computer
Interface . . . . .

$265-00

283*95
235*00

KUvl

OSCAR Antennas in Stock * .

KANTRONICS

The Challenger $ 99.00

UTU Interface . , , . 179.00

Interface II 219,00

Large Variety of Software Available
for RTTY, CV. Ascl i 6 Amtor

CALL FOR PRICES & INFORMATION

HYGAIN

TH7 0XS Tr 1 bander . . . *
TH5 MK2S Tribandtir. . , -
Explorer 14 Tribander . .
CD45 8*5 Sq. Ft. Rotator
Ham IV 15 Sq. ft. Rotator
T2X 20.0 Sq* Ft. Rotator
V2S 2 Mtr Vertical . , .
5/8 2 Htr Mag. Hnt * . .

$225-QO/$270.00

$1+25-00
369,00
269-00
129.00

199-00

2^3.00

49.00

25.00

KEN PRO

KR-5Q0 Elevation Rotor , . « «

LARSEN

NLA I50 MM 5/8 Wave 2H Mag. Mt.

MFJ

9^10 Tuner, MTR, Switch, Balun
1224 £ 1228 Computer Interfaces
313 VHF Converter ».,.,.,.

$185*00
39^95

$ 39.95
CALL

36.00

$215.00
279-00

149

00
00
00

471A/47TH 430-^50 Mtr ♦ . .
IC27A, 37A, 4?A, 2MT 22QMhz.

2AT 2Mtr H.T

3AT/1jAT Handhelds . . ♦ , ,
02AT, 04 AT Mew H.T. Series
PTT or VOX Boom Hfx Headsets

Free Shipping on all Crank-up Towers

I COM

751 Ultimate Transceiver
745 General Coverage Xcvr
730 Great Mobile Rig . ,
R-71A Gen. Cov. Rcvr . .
271-A/271H 2 Htr ...
27H 4$W 2 Htr

199-00
. . . CALL
. . . CALL

. . . 643.00

S615. 00/789. 99

. . . $359-00

$699-00/^9.00

440 Mhz

tch

$ 63*00
105-00

I25.OO
23*00

VERY
KDK

2033
£+033
7033

LARGE JCOH STOCK

25W Mob 1 le
220Mhz Hobi le
440 Mhz Hob Me

CALL
215-00
235*00
CALL
39- DO
CALL

$265-00
339-00
339*00

VERY LARGE STOCK
VIOEO PROOUCES

Ml RACE

B1016. 10-160 Amp/Preamp .

B30I6 30-160 Amp/Preamp .

01 01 ON kkO Mhz Amp . .

NYE

MBV5 3KV Deluxe Tuner
SHURE
444D HI/LO Desk Kid. .

TEN TEC

560 Corsai r .

525 Argosy »,,>...

2531 2 Htr H.T

251 0 Satel 1 1 te Stat ion .
Century 22 CW Xcvr . , ,

TQKYG HY POWER

YAESU

FT980 Computer Aided Xcvr
FT757 GX Super Value

FT726R T ri-Band X cyr- -
FT203R W/TT Pad. ■ . ♦

FT209S New SW H.T* . * .

OF HFC PRODUCTS INCLUDING

CALL FOR DISCOUNT PRICES

$2*15.00

,,.... 193.00
279-95

$^75*00

$ 55.00

$1 ,020,00

* « , . , 535*00
..... 269.96

439.00

359.00

CALL FOR DETAILS

CALL

CALL
479,00
229.00
CALL

Send SASE for our new & used equipment list
MON-FRI SAM ■ 6PM * SAT 9AM ■ 3PM

USED EQUIPMENT

This list was compiled 9/13/84.
Our used equipment, changes daily,
Please write or call for our cur-
rent 1 i st i ng.

MatterCd"!

AEA

CP-l/6^ Interface Package

AZDEN

PCS-3000 2 Mtr* . . * , .

PCS-4000 2 Htr.

PCS 300 H.T. .....

PCS 300 Spkr/Mlc ....

PCS 4S00 10 Mtr

DENTRON

MT 200GA

HT 3000A .

JR Mon 1 tor .,.,...

DRAKE

I n/ * i > : I t t , I - •. * ■

PS? - * .

TR7, 500hz, fan/PS7* fan

7077 Desk Hie

r R 3 j Rv 3 f AC .....<

ENCQMM

ST ]kk Up 2 HTR HtT

ST 7T ^0 Mhz

HAL
CT 2200+ KS^lOO . . * > i: .

HEATHKIT

rlrT I U I } r J ■ 1 w ■ r m m ■ ■

SB&00, Spkr ...*.,,
SA 20^0 Roller Inductor Tune

PS 9Q00 PTS., Spkr, Clicks

HYGAIN

HG 52SS Crank^up Tower , *
HDR 300 Digital Rotator . ,
TH5DX 5el Tribander ....
*l02BA 2el i»0mtr .,...,

$185.50

S7-09.50

229.50

189,50

20.50

215-00

SI 59-50

225*50
49.50

$62 5.00

185*50

849.50

29.00

269.00

$199-50
169.50

. S649.50

. $269.50
25*60

. 139.59

. I69.50

. $693,50

, 339-00

* 149.50

. 169-00

[COM

720AT CW ....
740 Xcvr ....
7^0, Internal P.S. FL4^*
720 Gen, Cov - Xcv r

PS-20 20A, spkr .
2AT 2Mtr H.T, . *
25H ^5W 2 rntr
R70 Rcvr ....
AG-1 UHF Pre- Amp

KANTROMC5

The Interface . .

Vic 20 Hamsoft .

Vic 20 Hamtext .

$625*00
599-50
783-50

548,50
155-00

18S, 00

239-50

459-50

59*50

S 69*50

29-50
53-50

m . . . .

NB * , , •
21 Digital
21 .

KENWOOD

R600 Receiver . , .
TS70OA 2 Mtr Al 1 mode
RM 76 Remote ....
TR240O H.T. . . . .
Leather Case* . , . .
ST- 1 Chgr ,,*...

MFJ

1224 Interface . . .

Cwf-2 FI 1 ter , , - ,
k8k Grandmaster Keyer

101 24 Hr, Clock . ,

752 Dual Fi Iter . .
496 Super Keyboard

$249

323

179

50
50
50
50
50
50

s 69.50

13*50

S 93-50

19.50

43.50

179-50

30 DAY WARRANTY ON USED

TEN-TEC

0MNI-C ,
DMNI-D/B
DUN I -A/B
544 , CW.
540, CW.
574 Cent
570 Cent
255 P. S. /spkr , . .

280 P. 5

252MP.S

262G P,S,/&pkr - .
6^5 Key cr . . . ,
234 Speech Proces&or
Vfo Del ta ....

YAESU

FT901DM

FT101E

FT301D/FF3O1D . . .
FL210QB 1 .2Kw 10-80M
Land Line Phone Patch
YR-301, YK901 Reader, Kybrd
FT221R 2mtr All mode

FT202 H.T

FT301 SD Xcvr . . ,
MISC.

Diawa CNA 1001 Autotuner
KLM KT 34 xA 6EL Tri bander
Galaxy 5 HK 1 P.S.
Galaxy Vfo . • , .
DX 200 Rcvr - - * *
Micro Craft Reader
Lunar 2M 10-SOP Amp
Pace Comrn. Mx 2Mtr H
KLM PA 100-I60B 2 mtr Amp
VHF PA 10-140 2 mtr Amp
Alliance H0-72 Rotator -

S 599. 00
403,50
369.50

369-00

239,50

289.50

239,50

113-50

99.50

85-00

85,00

53.00

63.50

125-00

$589.50
499-50
499*50
i|25,00

49-50
h 53* 00
289*50

99*50
273-00

$225.50

373*50

199.50

69-50

33.50

99.50

95.50

89.00

163,50

129.00

55-00

Send SASE for

MON-FR1

our new & used equipment list.
9AM 6PM * SAT 9AM-3PM

Addresses of

SCF Manufacturers

National Semiconductor

Corporation

2900 Semiconductor Drive

Santa Clara CA 95051

Motorola Semiconductor
3501 Ed Bluestein Blvd.
Austin TX 78721

EG & G Reticon
345 Potrero Avenue
Sunnyvale CA 94086

The R5620 and other inter-
esting devices are avail-
able from:
Applied Invention
Rte, 21, Box 390
Hillsdale NY 12529

versatile filter, particularly
since all of the basic filter
operations are available on
one chip. Since the cutoff
frequency and the Q can be
varied, this type of filter is
useful for SSB, CW, and
RTTY operations.

For example, if you are
using a Bell-202-compatibie

modem, you'll be using
tones of 1200 and 2200 Hz.
You can build a switched-
capacitor filter for each
frequency, deriving the
clock signal from one com-
mon crystal. The frequency
would be 1200 X 2200,
or 2.640 MHz. Since the fil-
ter's clock frequency must
be 100 times the center fre-
quency of the signal being
filtered, dividing the 2.640-
MHz clock by 22 and by
12 gives the proper clock
signals for the two filters;
120 kHz and 220 kHz, re-
spectively

In this application, band-
pass filters would be used
and the cutoff frequency
controls would be preset.
The Q of both filters could
be set in parallel by a single
control or each could be set
separately.

A filter-and-monostable
RTTY demodulator is de-
scribed in the 1982 edition
of The Radio Amateur's
Handbook,12 and several

SCF circuits could be used in
place of the op-am p-based
active filters. Using SCF cir-
cuits allows the filter char-
acteristics and frequencies
to be easily changed.

Switched-capacitor filters
provide an alternative to
op-amp-based filters in
many ham-radio applica-
tions. They are not much
more expensive than the
classic circuits, particularly
when you consider their
flexibility and the ease of
designing circuits around
them. I think you'll see more
amateurs using SCF chips
and coming up with new ap-
plications for themB

References

1. Robert E. Lee K2TWK, "Build
an Audio Filter With Pizzazz!",
QSTt February, 1982.

2. Tom Cook N3AXN, "Concept
and Construction of a CW Filter
and Enhancer/' QST, April, 1982.

3. Howard M. Berlin W3HB, De-
sign of Active Filters, with Experi-
ments, Howard W. Sams and Co.,
Indianapolis IN 46268, 1977,

4. Several active filters are de-
scribed in The Radio Amateur's
Handbook, 1983 edv pp. 8-30,
8-44, and 8*53,

5. Doug DeMaw W1FB, "Under-
standing and Using Audio Fil-
ters,'* QST April, 1983.

6. Howard M. Berlin W3HB, De-
sign of Phase-Locked Loop Cir-
cuits, with Experiments, How-
ard W. Sams and Con Indianapo-
lis IN 46268, 1978.

7. David Jagerman KC2FR, 'The
KC2FR QRM Fighter/ QSTt Ju-
ly, 1982.

8. R Charman G6CJ, "Coherent
Audio Filters for CW Recep-
tion," Wireless World, Novem-
ber, 1980,

9. Tim Regan, "Switched-Capac-
ttor ICs Improve Filter Specs,
Ease Design/' EDN, June 23,
1982,

10. Richard Schellenbach W1 JFT
"Versatile Switched-Capacitor
Filter with ALC,n QST, Novem-
ber, 1982,

11. Steve Bramblett, "Adjust-
able Clock Tunes Notch Filter/'
Electronics, February 24, 1983.

12. "A General-Purpose RTTY
Terminal Unit/' The Radio Ama-
teur's Handbook, 1982 ed., p.
14"4o,

State of the Art Kits by Hal-Tronix, Inc.

HAL 2304 MHZ AMATEUR DOWN CONVERTERS

IFREQ RANGE «WKIi'25Q0 MHB
2304 MODEL*! KIT

BA5IC UWT W4TH FHfAMP L.E55 PIE CAST CASE * FITTHJCS
230* MODEL tf I HIT
B^SIU UN:*- WITH PRET-A.MPWITH D^ CAST CASE A FITTrNGS

2KH MODEL*! KIT

BASIC WITH HH43AIM PRC-AMP WITH DIE-CAST CASE *• FITTINGS

POWER SUPPLY

FDR THE ABOVE COMPLETE WITH ALL PAflTS i.ESS CASE

POWER SUPPLY CASE

RlAC* PlASTIC CASE UNDRfLLtLF

CQWiFEH PARACEPTQFLAh 'IN 14 A

lJE!HFECT FOR THE 230* MOD 2 13 ft DB OVER ANY LUSH

HAL-PA It QHZ 2 STAGE PREAMP [KIT| (M-BS

DESIGNED FOR THE 23«M DOWN CQWERTEP. MACE TO PIGCJE BACK 0*1 THE ZSOfl HOARD OFFERS 22 OB
MORE GAiN. MAS I MACE REFECTION FILTER

PRE- AMP TR AN515TOR EXCHANGE JS.QO

EXCHANGE TRANSISTOR l« 23(H WITH NEC S4535-

.129.9*.

MB.B5

SLOTTED ARRAY A NTE N M A

1tf OB GAIN U5-E WITH 2304 MOD ' KIT NO CAGE REDLIhRED

AMATEUR MICROWAVE RECEIVER
21 00-2500 MHZ

-AMR COMPLETE UNIf

COMPLETE SYSTEM AS SHOWN, MOT A KUT tNClUPES A PflE-ASSEMBLED
PROBE DOWN CONVERTER. DISH. POWER SUPPIV. CABLES AND CONNEC-
TORS TESTED UNIT OFFERS 34 DBC*IN OR GRESTER

■4jYQM(M m.K

BUYTHREEORMOHE IS9.951*.

-AMATEUR MICROWAVE RECEIVER

PRE SCALER KITS

HAL 300 PRE

=■'. nrjARP AND ALL COMPONENTS

HAL3WJ AVPRE

PG BO-AND ftNU ALL COMPONENTS won »H£.flMP-ONBOAN!D

HIALDOOPHE

PC HOARD- AND ALL COMPONENTS

HAL 600 AJPRE

PC BOARD *ND ALL COMPONENTS WITH PflE-AMP ONDQARD

HAL 1.2 GHZ PRE SCALER

BUILT AND TESTED REQUIRES 5 VOtTS D.C

SHIPPING INFORMATION: ORDERS OVER J25 WILL BE SHIPPED POSTPAID EXCEP" ON ITEMS WHERE ADDI-
TION Al, CHARGES ARF RFOUESTED On ORDERS LESS THAN *36. PLEASE INCLUDE ADDITIONAL 12 50 FOR
H-ANCLING ANC MAiLlNC CHARCES. MICHIGAN RESIDENTS ADD 4Vi SALES TAX ftEND 20- STAMP OR SASE
fan FREE fLYER CANADIAN ORDERS ADD S-xDO POSTAGE IN US ^UNDS

Hal-Tronix, Inc. -31 WP-^ ^

P.O. BOX 1101 -DEPT.7 ^

SOUTHGATE, MICH. 48195
PHONE (313) 285-1782

i£S

"HAL" HAROLD C. NOWLAND
WBZXH

AMATEUR TELEVISION

ATV TRANSMITTER/CONVERTER

iTV TRAN5KITTIft/£«NV

ALL YOU NEED IN ONE BOX

SpOaw delivered
T01 plus

• OVER 10 WATTS PEP OUTPUT. Crystal controlled continuous
duty transmitter. Specify 439.25, 434 0. 426 25 standard or other
70 cm frequency 2 freq. option add S26

• BASE, MOBILE, or PORTABLE. Use the builtin AC supply or

external 13.8 vdc Do parades. Marathons. CAP searches, etc

• TWO VIDEO AND AUDIO INPUTS for camera, TVRO VCR W
computer Wide bandwidth for broadcast quality color Video and
computer graphics. Standard broadcast subcarner sound which is
heard thru the TV speaker.

• RECEIVE ON YOUR STANDARDTVSETtuned to channel 3 or 4.
Sensitive vancap tuned TVC-2Ldownconverter covers simplex and

repeater freq. over the whote 420-450 mHz 70 cm amateur band-

• ATTRACTIVE 10,5 x 3 x 9 CABINET.

CALL OR WRITE FOR OUR CATALOG or mure pflforrnatwfl on

ATV antennas. transmit modules, cameras. et£: or who is on m your area
See chapter 1 4 1 984 ARRL Handbook

TERMS Visa. Mastercard, or cash cnjy UPS CODs by telephone or mail
Postal money orders and telephone orders usually shipped within 2 days. All
other checks must clear before shipment. Transmitting equipment sold only
to licensed amateurs, verifiable m the 1 984 call book

(81 8} 447-4565 m-f 8am-6pm pst

P.C. ELECTRONICS

Tom W60RG Maryann WB6YSS

2522 Paxson Lane
Arcadia CA 91006

40 73 Magazine ■ November 1984

ICOM

Hf Equipment Regular SALE

1C-740* 9 band 200w PEP xcvr w/mrc$ 1099.00 899"

*FREE PS-740 Internal Power Supply &

$50 Factory Rebate - until gone!

PS-740 internal power supply 1 59.00 149"

*EX241 Marker unit.. 20.00

"EX-242 FMumt 39.00

*EX-243 Electronic keyer unit 50.00

*FM5 500 Hz CW lifter (1st 1F> 59.50

♦FL-54 270 Hz CW filter (1st IF(.... 47.50

♦FL-52A 500 Hz CW lifter (2nd IF) 96.50 89"

*FL^S3A 250 Hz CW filter (2nd IF) 96.50 89"

♦FL-44A SSB filter {2nd IF) 159.00 144"

SM-5 Spin etectret desk microphone 39 00

HR-10 Scanning mobile microphone 39.50

MB 12 Motaile mount 19.50

^Options also for iC-745 listed below

IC-730 8-band 200w PEP xcvr w/mic $829.00 569"

FL-30 SSB filter (passband tuning) 59,50

FL-44A SSB filter (2nd IF).. 159,00 144"

FL-45 500 Hz CW lifter 59,50

EX- 195 Marker unit „.♦*♦„., 39,00

EX-202 LDA interface; 730/2KL/AH-1 27.50

EX-203 150 Hz CW audio filter 39.00

EX 205 Transverter switchrng unit 29.00

SH-5 8-pin electret desk microphone 39.00

HM-10 Scanning mobile microphone 39.50

MB-5 Mobile mount 19.50

(C-720A 9 band xcvr/ 1-30 MHzrcvr $ 1349.00 899"

FL-32 500 Hz CW filter 59.50

FL-34 5.2 kHj AM filter 49.50

SH-5 8-pm electret desk microphone 39,00

KB-5 Mobile mount 19.50

IC-745 9 band xcvr w/.l 30 Mhz rcvr$999 00 769"

PS-35 Internal power supply 160.00 144"

CFJ-455K5 2.8 kHz wide SSB filter 4.00

HM-12 Hand microphone 39 50

SM-G Desk microphone 39 00

*$ee tC*740 list above for other options (*)

IC-75I 9band icvr/.l-30 MHz rcvr $

PS-35 Internal power supply .

FL-32 500 Hz CW filter (1st IF)--...

FL-63 250 Hz CW filter (1st IF)

FL-52A 500 Hz CW filter (2nd IF)...

FL-53A 250 Hz CW filter (2nd IF)...

r L- Jw t\pti uier*.**.?- ».......***»»*

FL-70 2.8 Khz wide SSB filter

HH-12 Hand microphone ....

SH-6 Desk microphone

CR-64 High stability reference Ktal

RC-1Q External frequency controller

MB- 18 Mobile mount

Options: 720/730/740/745/751
PS-15 20A external power supply

EX444 Adaptor for CF-l/PS-15 ....

1399 00

160,00

59,50

48.50

9650

96.50

31.50

46.50

39.50

39.00

5600

3500

19.50

Regular

$149.00

6.50

1189
L44"

89"
89"

SALE
134"

■ m m m m <■

Options - continued

CF4 Coohngfanfor PS15.
EX-310 Voice synth for 751 R 71A
SP-3 External base station speaker ...
Speaker/ Phone patch - specify radio

BC-10A Memory back-up ...

EX-2 Relay box with marker

AT- 100 1 GO w 8-band automatic ant tuner
AT- 500 500w 9 band automatic ant tuner
AH-1 5- band mobile antenna w /tuner
PS-30 Systems p/s w/cord, 6-pin plug
OPC Optional cord, specify 2 or 4-pm

GC-4 WorirJ clock „„....

HF linear amplifier

IC-2KLw/ps 16015m solid state amp

VHF/UHF base multi-modes
IC-251A* 2m FM/SSB/CW transceiver

*$50 Factory Rebate

Regular

45.00

39.95

49.50

139.00

8.50

34.00

349.00

449.00

289.00

259.95

5.50

99.95

Regular

1795.00

SALE

1291!

314"
399"
259"
233"

94"
SALE

1299

Regular SALE
1749,00 549"

until gone!

IC-551D 80 Wait 6m transceiver

EX-106 FM option....,

BC-10A Memory back-up

SM-2 Electret desk microphone ....
1C-Z71H lOOw 2m FM/SSB/CW xcvr

P3-35 internal power supply

PS- 15 externa* power supply

CF4 Cooling fan for PS 15. .,.

IX 144 PS-15/CF 1 fan adaptor

AG-25 Mast mtd. GaSFET preamp
IC-471 H 75w 430-450 SSB/CW/FM xcvr

PS-35 Internal power supply

PS-15 20A power supply

CF-1 Cooling fan for PS 15

EX-144 PS15/CF I fan adaptor

AG-35 Mast mounted preamp

IC-271A 25w 2m FM/SSB/CW xcvr...
PS-25 Internal power supply

AG-20/EX-338 2m preamplifier....
IC-471A 25w 430 450 SSB/CW/FM xcvr

AG-1 Mast mounted 15dB preamp

PS-25 Internal power supply

Common accessories for 271 A/H

SM-G Desk microphone

EX-310 Voice sythesjzer

TS-32 Co mm Spec encode /dec oder ,,.

UT-15 Encoder /decoder interface. . .
UM5S UT 15$ w/TS- 32 installed ....
VHF/UHF mobile mutti-modes
IC-290H 25w2mSSB/FMxcvr,TTPmic
IC-49QA 10w 430440 SSB/FM/CW xcvr
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IC-22U lOw 2m FM non digital xcvr

EX- 199 Remote frequency selector
IC-27A Compact 25w 2m FMw/TTPmic
IC-27H Compact 45w 2m FMw/TTPmic
IC-37A Compact 25w 220 FM. TTP mic
IC-47A Compact 25w 440 FM, TTP mic

UM6/EX-388 Voice synthesizer...
IC 120 Iw L2 GHz FM transceiver....

ML 12 lOw amplifier..,..,.....,...
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IC SOS 3/10w 6m port. SSB/CW xcvr

BP-10 Internal Nicad battery pack

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125.00 112"
8.50
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399.00 799"
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149 00 134"
45.00
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45.00
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99.00 89"
56.95
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89.00

99.00 89"
and 471 A/H
39.00
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EX-248 FM unit

LC-10 Leather case ..
SP-4 Remote speaker

MMH4rii>-M*

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29900

35.00

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409 00

449.00

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2995

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419"

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379.00

Regular
239,50
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299 95

29995

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Accessories for Deluxe modeh Regular

BP-7 800mah/132V ticad Pah ■ use BC-35 6750

BP-8 800mab/84V Nod Pak - use BC 35 62.50

8C 35 Drop in desk charger ■ all batteries ., — . 69,00

BC-60 Six position gang charger all batts TBA

BC-16U Wall charger ■ BP7/BP8 , 10.00

Ace essories for both models Regular

BP-2 425mari/7^V f*cad Pak - use BC35 39.50

BP-3 Extra Slri 250 mah/8.4V Mead Pak 29-50

BP^4 Alkaline battery case 1250

BP-5 425mah/108V Ntcad Pak - use BC35 49.50

CA-2 Telescoping 2m antenna 10.00

CA-5 ^wave telescoping 2m antenna 18.95

FA-2 Extra 2m flexible antenna 10.00

CP-1 Qg. lighter plug/cord ■ BP3 or Otx 9.50

DC- 1 DC operation pak for standard models 17 50

LC-02AT Leather case tor deluxe modets,... 39 95

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LC-11 Vinyl case for standard models

LC-14 Vinyl case lor Deluxe models

RB-1 Vinyl waterproof radio bag
HH-SS Handheld shoulder strap
HM-9 Speaker microphone —
HS10 Boom microphone/ headset

HS40SA Vox unit foe HS10 (dbc only)

HS40S8 PTT unit for HS^IO 19.50

Mil 2m Z3w tn/lOw out ampler ........ SALE 79.95

ML-25 2m 2.3w in 20w out amplifier ....... SALE 179.95

SS-32M Commspec 32 tone encoder 29.95

Shortwave receivers Regular SALE

R-71A 100 Khz-30 Mhz digital receiver $799.00 689^

FL-32 500 Hi CW filter,.,... 5950

EX-310 Voice synthesizer „ 39 95

RC-11 Wireless remote controller... 59 95
CR-64 High stability oscillator xtal
R-70 100 Khz 30 Mhi digital receiver
EX- 257 FM unit.. ,.

749.00 599"
38.00

IC-7072 Transceive interface, 720A 112.50

FL-44A SSB filter (2nd IF) ..

FL-63 250 Hf CW filter (1st IF)

SP-3 External speaker —

CK-70(EX-299) !2vOCopbon

MB- 12 Mobile mount

159.00 144"

48.50

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1950

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73 Magazine • November, 1984 41

Your Own

Optoelectronic Anemometer

Light control and car-top calibration make this project
cheap to build, easy to align, and extraordinarily accurate.

< Juries / i letter KiVDB
1 1 5 Dixie Drive
Red Lion PA J 7*56

In my January, 1983, 73 ar-
ticle, the question was,
"Can you realty see which
way the wind is blowing with
optoelectronics?" Now, I
ask, can you really see how
fast the wind is blowing?

The answer to both ques-
tions is, of course, yes We
will use the GE H13A1/H21A1
interrupter module to tell us
wind velocity— how fast the
wind is blowing,

Perhaps I should reiter-
ate at this time that the (it
number for the H13A1 in-
terrupter module has been
(hanged from H13A1 to

H21 A1 , The modules are in-
terchangeable So from
here an, I will refer to it as
the H21A1.

General Circuit Description

This circuit uses very few
electronic components, A
good portion of the work in-
volved in building the ane-
mometer head is the me-
chanical end of it. But more

about that later. The elec-
tronic components consist
of an H21A1 and a 2N3904
transistor line driver up in
the head of the anemome-
ter. Down in the shack there
is an LED that blinks when
the wind is blowing (I am
not quite sure why I put
that in there— I guess I just
like whistles, lights, and
bells) There are twelve in

Photo B. Anemometer head with cups removed showing
Photo A. Anemometer head with weather cover removed, top bearing seal and side mounting surface.

42 73 Magazine • November, 19S4

Mph

Pps

Rpm

.17

7.2

,33

14.3

107

.50

21.5

161

,67

28.7

215

.83

35.8

269

ija

43.0

322

High

Scale

21.5

161

.•So

43.0

322

.50

64.5

484

.67

86.0

845

.83

107,5

606

1.0

129.0

967

G€> MOV
VIBZAI

Table 1. Speed conversion
chart.

verter gates in the two DIP
packages, a few resistors
and capacitors, a 3.6-volt

power supply, and a 1 -mi Mi-
amp meter. Perhaps I
should mention at this time
that the meter and your cal-
ibration are the only two
things that would limit the
accuracy of the electronic
circuit The electronics are
extremely linear, so it is im-
portant that you use a good
meter, one with which you
can redo the scale as we
did — it's not hard. More on
that later, too.

TheMC789PorECC9989
RTL inverters are part of an
old family of ICs, but they
are still readily available at
an inexpensive $3.00 price.
The most important reason
we like this circuit is that it
works without a hitch.

The trend toward digital
readouts is usually an im-
provement over the old an-
alog meter, but there are al-
ways exceptions to the rule
and, in my opinion, wind
speed is one of them, Un-
less, of course, you need a
digital number to be used in
an automated calculation,
the otd analog readout is a
more comprehensive repre-
sentation of what the wind
is doing.

About the Circuit

From the schematic and
the test-point waveforms in
Fig. 2, the theory of the cir-
cuit will become apparent.
A three-wire shielded cable
is required to connect the

Fig. 7. Velocity meter circuit. Alt resistors V* W except as noted. All capacitors uF. Look on
top of H13A1/H21A1 for correct pinout

anemometer head, up on
the tower, to the readout in
the shack From thereon it's
just ones and zeros. Well,
almost. The first entire IC
package (6 gates) is used for
shaping and compensating
the input pulses. The sec-
ond chip uses an RC net*
work to generate a low for
the exact period of time it
takes to make the meter
read correctly.

Switching-in the 47 ^F
capacitor affords you a full
scale of 30 mph (a good
scale for normal operation);
during a storm, flipping the
switch will give you 90 mph
full scale. The 2000-jiF ca-
pacitor across the output
tailors the meter to a nice,

TP*t

2LOV PEP

TP#?

I 9V PE.P.

TP#3

3.5V P. E.P

TP#4

_f""

REP

TP#S

VARIE5 WITH GAL POT AMD
/"FULL SCALE SWITCH fWTlON

tflV PE.P.

TP #6

3 5V PEP

Fig. 2. Pulse trace. Waveforms taken with 43 Hz in, 2-ms
sweep.

73 Magazine • November, 1984 43

Photo C. A view of the bottom of the top bearing and the
gasket that will seal the weather cover

smooth, responsive move-
ment The 36-volt power
supply is a snap; we used
one of the adjustable three-
terminal regulators from
Radio Shack (number
LM317TJ. ThelSGOhmpot
allows ease of adjusting the
output to 36 volts.

The data in Table 1 con-
cerning mph, mAr pps, and
rpm is supplied for refer-
ence only. Your anemome-
ter may not perform exactly
as mine did, but this data
will give you a starting
point.

If you have a signal or
function generator with a
1.5- to 3-volt range and you
can adjust its frequency
from 7 Hz to 130 Hz with
reasonable accuracy, you
should be able to duplicate
these readings by substitut-
ing your generator for the
input from the anemometer
head, I have gone one step
further and used the gener-
ator to drive the H21A1
emitter directly by remov-
ing the "lOOOhm dropping
resistor from the 3.6-V posi-
tive bus and connecting the
generator to the free end of
the resistor and to the nega-
tive bus. Of course, in this
case, the anemometer head
will remain connected to
the readout board.

As seen in the photos, the

electronics in the head and
at the readout are mounted
on PC board, Radio Shack
#276-170. But ! cannot rec-
ommend this board. For my
purposes, the board worked
out fine mechanically How*
ever, when I wanted to sol-
der to it, solder would not
flow as I thought it should
(even after cleaning), so ad-
ditional flux was used result-
ing in nice wet-looking joints
but a lot of flux residue. The
board was tested and
worked fine. By the way, the
circuit was debugged and
tested on a push-on bread-
board before assembly on
the Radio Shack board,

The board was then
washed in a commercially
available flux remover, and
that's when my trouble
started. After a few hours of
"What the h— happened to
this thing?" and "I can't be-
lieve what the scope is say-
ing/' f finally found I had
contamination bridges all
over the board. I had never
used fiber PC board before
and never will again, f had
used the flux and flux re-
mover together lots of
times with no trace of trou-
ble, but always on glass
board, I finally washed the
whole thing in detergent
and water after trying some
other solvents to no avail.

Photo D. The disk interrupter with its 8 holes running
through the H211 interrupter module.

After drying and retest-
ing, I gave the solder side of
the board a coat of clear
Krylon™. It has been doing
fine ever since. The moral
to the story is to use a good
glass epoxy board.

There is only one other
electronic component that
bears mentioning, that be-
ing the CE MOV #V18ZA1
metal oxide varistor, locat-
ed in the anemometer head
It plays no part in making
the circuit work; its job is to
limit the voltage on the
3.6-V bus during a lightning
strike or other power-line
spike. They have proven to
me to be very effective in
their job of over-voltage
spike protection If these
units are sized correctly for
the job, they will conduct
during a spike and then re-
store to normal, over and
over again For their low
price they sure can save
you a bundle of trouble So
a word to the wise is suffi-
cient: If you are not familiar
with the MOV line, you may
needlessly be jeopardizing
some of those priceless
gems in your shack,

The Mechanics

The model pictured in
Photo A has 4" cups. They
are bigger than they would
have to be for just a wind-
velocity meter These cups
were fabricated from 4"

aluminum funnels, I cut the
snouts off the ends of the
funnels and bent very thin
aluminum sheet metal into
the shape of a cone to close
the holes Then I secured it
to the funnels with alumi-
num pop rivets. I would
suggest using aluminum
soup ladles, approximately
the two-inch size, for your
cups. The rods are VS "
aluminum, threaded on one
end to secure the cups, and
they're approximately 2,25
times the diameter of the
cups in length. The hub that
mounts the rod to the bhait
was machined from a solid
piece of aluminum round
stock 2" x«" thick. Holes
were drilled and tapped for
set screws to secure the
rods and shaft. If soup la-
dles were used I am sure
some bolting or clamping
arrangement could be de-
vised to secure the ladle
handles to the shaft. This
would eliminate the need
tor a machined hub, if the
machine work is a problem.
I would also recommend
using a %" shaft instead of a
Vi " shaft.

Photo B is a view of the
anemometer with the cup
assembly removed to get a
better look at the top bear-
ing seal and the side mount-
ing surface. The top bearing
seal is exactly as described
in the previous article ex-

44 73 Magazine ■ November 1984

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73 Magazine • November, 1984 45

cept it is epoxied to the
shaft instead of clamped
with a set screw. The
mounting surface would
depend on what you are go-
ing to mount it on We
mounted the wind-velocity
and directions heads on a
piece of 2,PX2'* box alumi-
num approximately 5' long
and bolted it to the tower.
There will be some wind
load so whatever you
mount it on must be good
and stiff.

Photo C is a view looking
up under the top plate to
show I hat the bearings in
this unit were pressed into
the Va * top plate and bot-
tom plate rather than using
bearing blocks as described
for the wind-direction mod-
el 1 prefer the bearing block
method because of ease of
precision alignment Also
shown in Photo C is the cork
gasket used for sealing the
five-sided weather cover

Photo D is a look at the
disc interrupter running
through the H21A1 with its
associated electronic com-
ponents such as the 2N3904
line driver, the V18ZA1
MOV, etc, The disk inter-
rupter is nothing more than
a 2 Vi "round by V'-thick

iiluir Jin dis< with eighl

evenly spaced IS " holes in
it It is secured to the shaft
by a machined collar It
also serves as the bottom
shaft stop, which rides on
top of the bottom bearing
Collars such as those pic-
tured in Photo C can be pur-
chased for approximately
SI 00 at any machinery
house, and the interrupter
disc could be epoxied to it
instead of a machined
collar

The PC board is mounted
on a piece of aluminum an-
gle with insulating standoff
washers [such as are used in
mounting transistors to heat
sinks}. The hole in the bottom
plate that the angle mount-
ing screw goes through is
oversized to facilitate align-
ment. The same method used
in the wind-direction indica-
tor for getting wires off the

Photo E. The circuit hoard that drives the readout meter
Note test points.

Photo f. Rear ol readout panel.

board and down to the
shack is used here There
are two male pins near the
top of the board and one fe-
male pin covered with
shrink tubing below. Anoth-
er method would be to run
the three wires of the board
to a barrier strip as pictured
in Photo F, but with only
three lugs of course.

Photo E is the electronics
board at the readout. Lay-
out of this board is not criti-
cal. (Where have I heard
that before?) The vertical
trimpot at the right-hand
i orner is the ( alihration
pot. It's the only electronic
adjustment in the whole cir-
cuit except for the power-
supply voltage.

Photo F is a view of the
back of the readout panel
This panel as seen in Photo
G is used for wind direction
and velocity with some
spare room for future gen-
erator control. On the left is
the velocity meter with the
2000iiF capacitor across its
terminals. Under the meter
are the range switch and
blinking LED. On top is the
barrier strip on which all the
wires terminate that go to
the two heads up on the
tower. Next are the elec-
tronics board as pictured in
Photo E, the 3,b-V regulator
and adjusting pot, and the
5-V regulator for the wind
direction electronics. Be-
low are the rectifier bridge.

filter- capacitor, power
transformer, line fuse, and
on -off switch

Photo C is of course a
front view of the readout
panel. Perhaps now is as
good a time as any to talk
about the meter scale. As I
mentioned before, this
scale was hand calibrated,
reincremented, and num-
bered. For those of you who
have never tried that sort of
thing, let me tell you, it's
not as hard as you might
think. However, you must
start with a one-milliamp
meter that you can sepa-
rate without destroying. We
will get into calibration
shortly.

Take the meter apart and
very carefully remove the
face. You will find the big
ger and better meters are
easier to work with. Then
spray the face with a flat
white spray can until all
traces of the old markings
are no longer visible except
0 and full scale. When dry,
give it a coat or two of clear
Krylon. Now new incre-
ments and numbers can be
put back on with compara-
tive ease. Use a fine felt-tip
black indelible pen, such as
used to mark clothing, for
the increments. They must
all point to the pointer
shaft. The meter in Photo G
has a 4 " face and I used Vi "
vinyl stickon numbers. You
can also use roll-on num-
bers but in my opinion, they
are harder to work with. The
pen and the numbers can
be purchased at any sta-
tionery store,

Calibration

I am sorry to say I have no
sure-fire method for you to
follow. But I can tell you
how I set mine, and it dupli-
cates the reading of a com-
mercial unit not far away.
After looking high and low
for a calibrated wind tunnel
with an aperture big enough
to get this thing in, 1 finally
gave up and decided I must
come up with some other
method. The only way I
could think of to calibrate

46 73 Magazine • November, 1964

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Audio Input — Minimum level SmvRMS. Input
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AFSK Output — Crystal controlled. Mark-3125Hz; Space-
2295Hz (170 shift). Level lOOmvpp (35mvRMS) standard,
Optional 500mvpp (175mvRMS). Output impedance 600
ohm unbalanced.

FSK Output — Open Collector +40 VDC Max, Polarity can
be reversed.

Scope Output — 10K ohm output impedance.

PTT Output — Open Collector *40 VDC Max.

Computer Connection — TTL Compatible. Inputs also
RS232 level compatible,

Power Requirements — 11 to 15 VDC (12 VDC nominal)
75m a

Construction — Precision Extruded Aluminum Alloy
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Dimensions — L9"H x 5.9T*W x 7"D

Weight— l'Albs.

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isa?

EWLETT
PACKARD

MSMlUi:

the meter was with my Jeep.
It has a roof carrier on top so
it would be no problem to
mount the anemometer
head on it and just calibrate
my new gadget by driving
down the road using the
speedometer for my
reference.

But how accurate is the
speedometer? After beating

the bush a little more, we
found an automotive shop
that was set up to certify
auto speedometers for po-
lice departments, and after
telling the fellow what I
wanted, he agreed to test
my speedometer for a nom-
inal fee. He would make no
corrections but would give
me a graph showing what

Photo C, Face of readout pane!.
48 73 Magazine * November, 1984

my speedometer indicated
and what the true speed
was. Well, that sounded
good to me. It turned out
that my speedometer was
flat up to 70 mph* I am told
it is not unusual for an auto
speedometer to be a fairly
accurate device if the car
has the original size tires
and they are not worn too
badly,

I got everything ready,
brought a few pieces of
wood to help mount the
head to the roof carrier, and
installed the weather seal
cover, etc. As soon as a nice
zero wind day came along,
we would be ready to go.
The day finally came, with
my son Mike at the wheel
and me in the back seat
with all the goodies: a
counter, DVM, the readout
panel, and a 12-volt battery
which, by the way, is how
we powered the input of the
3.6-volt regulator during
our mobile test. After hit-
ting the open road, calibra-
tion went very well, I had al-
ready established, with the
function generator de-
scribed before, that the
electronics were sound. But
we had some apprehension
about the cups being non-
linear at the very low end
and the very high end. But
even with the over-sized
cups used in this model, lin-
earity did not display itself
as a problem. The calibra-
tion pot was set at exactly
30 miles per hour to indi-
cate 1 milliamp on the me-
ter (with the range switch
set to the zero- to thirty-
mi les-per-hour position). At
this speed, the counter indi-
cated 43.0 pulses per sec-
ond. With a few more tests
and a little help from the
calculator, we calculated
how many pps we should
get every five miles an hour
from 5 mph to as fast as we
could go.

Surprisingly, everything
held out very well. How-
ever, we still had some
doubts about the top end of
the 0-90-mph range, so I
said to Mike, "Lets make

one more high-speed run
and then head for home/'
Well, let me tell you every-
thing was looking good. We
came up through 30 mph,
45 mph, and 60 mph, and I
was thinking to myself that
if we could only hold 75
mph for a few miles 1 would
be satisfied that we had
made a valid test. I heard
Mike say "uh oh," simulta-
neous with what I recog-
nized immediately as the
wail of an electronic arm-
of -t he-law -type siren

1 think the cups on top
were still turning as that big
dude walked over to the
Jeep, He did not want to be-
lieve that thing on top was
not some new device de-
signed to foul up his radar.
Nor did he stop writing
when I mentioned that
maybe Wayne Green would
hear about this. So, like 1
said before, I wish I could
tell you a better way to cali-
brate this thing.

The test data in Table 1
was obtained from the
aforementioned test, so it
was possible now to go
back to the bench and use
the function generator to
reincrement the meter.

If you don't have a gener-
ator, you can mark the face
of the meter at the 5-, 10-,
15- 20- 25-, and 30-mph
points with a pencil while
you are doing your calibra-
tion run and then ink them
in later.

After reincrementing and
numbering the face, it was
given an additional coat of
clear Krylon, reassembled,
and ret es ted. The whole
system has worked fine
ever since,

May I take this opportu-
nity to thank my wile, Ann,
for her help and support
while getting this article to-
gether. And, of course, my
son Mike who got the
ticket, ■

References

Optoelectronics, General Elec-
tric Company.

Transient Voltage Suppression
Manual, Second Edition, Gener-
al Electric Company.

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73 Magazine ■ November, 1984 49

foe A. Elliott K&WVN
Flesher Corporation
PO Box 976
Topeka KS 66601

Rampant RTTY

Create the ultimate mailbox! K0WVN describes a system that
operates from 45 to 1200 baud with dual shifts — automatically!

AROM116 RTTY mail-
box system is a good
tool for local amateurs to
keep in touch with each
other on VHF and UHF fre-
quencies. It can also be used
in disaster-type operations
as temporary storage for
messages,

I witnessed a great need
for this sort of system when I
happened to be listening to
a bunch of VHF phone traf-
fic after a small tornado hit
a portion of Topeka. There

was so much delay caused
by hand copying and repeat-
ing of information that I felt
sorry for the operators. A
RTTY mailbox system would
have been the answer to
their communication prob-
lem; just a plain RTTY sys-
tem with a printer would
have done the trick.

Later, after the operation
was completed, the local
club did invest in RTTY com-
munications for both the
mobile unit and the base

station. I am sure that the
system will speed up this
sort of traffic handling and
improve accuracy. When
the traffic is coming in from
all directions, it is nice for a
RTTY system to remember
what was said and be able to
print it out when you want it
Flesher Corporation is
now the sole distributor of
the ROM-116 and is now re-
sponsible for its future. This
interface has proven to be
one of the most dependable

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Fig, 1, The circuit and the relay connections* Caution: Do not use the TU-1200fs 12-V-dc
power supply to supply the circuit or the relay. The TUA200 will not handle any supply
drain outside of the unit

50 73 Magazine * November, 1964

systems ever made to inter-
face with the Radio Shack
TRS-80 (Models I, III, and 4).
The author of the ROM-116
software, Craig Larsen
WA7HTN, and his partner,
Gary Martin W7XT, spent a
great deal of time creating a
system that would satisfy
even the most picky oper-
ator [such as myself).

Crown Microproducts (lo-
cated in Marys vi lie WA) was
made up of these two dedi-
cated hams, and between
the two of them, they creat-
ed their primary product
the ROM-116. I know that
Craig had spent a great deal
of time on the standard op-
erating software and was in
no mood to tackle another
project. His time spent
creating the software prob-
ably did not return him fifty
cents an hour, which sours
many a programmer from
creating hobby software to
begin with.

After so many hours of
Craig's time in writing the
standard RTTY/CW soft-
ware, it was a struggle for
the ROM-116 users to talk
him into writing another

software creation. It takes
time, patience, total con-
centration, and determina-
tion. You can imagine; both
of these fellas already had a
full-time job, and total con-
centration can be hard to
achieve in a family atmo-
sphere.

After several prototype
mailbox programs, Craig fi-
nally settled on version 1.4.2
MBO for the Model I and
3.4.2 MBO for Models III
and 4. I will briefly touch on
a couple of features that the
ROM-116 has to offer, at
least the ones we will be
working with on the addi-
tional circuitry,

The ROMH6 mailbox-
system communications-
rate feature is like none
other I have seen. It has abil-
ity to receive a remote com-
mand over the airways to
change the baud rate from
45.5 to 1200 baud. This is
one of the few (if not the on-
ly) systems that has the abili-
ty to run at this fast of a
baud rate and still maintain
a split-screen format. The
control operator has to ini-
tialize a baud rate agreeable
to everyone on the system,
and this initialized baud rate
will set a default If a mail-
box user accidentally sets a
speed that he is unable to
communicate with, the sys-
tem will delay and default
back to the speed set by the
control operator. This is
only one of many fine fea-
tures the system has to offer,
and it would take another
article just to explain the re-
maining features of the
KOM-116 mailbox software,

I had a problem with the
hams in this area when I
tried a system that had to
have an "open command"
before you could ask the
system for your mail (which
was another command on
top of that) After you start-
ed the mailbox system send-
ing your mail, you had to re-
main in the shack to grve it
an "exit command/' The
users of this mailbox system
started dying off, discour-
aged with the procedure re-
quired in order to get the

mail Most of the users
wanted a system that would
allow them to go into the
shack, give a read command
for their mailbox, and walk
off — having the messages
print out without having to
wait to close the mailbox.

The ROM-116 mailbox
software was the answer to
this problem, and everyone
was happy with the elimina*
tion of a lot of ''Howdy,"
"Exit" and all that sort of
chit-chat from the computer
on the other end. This is
called user friendly accord-
ing to some, but our group
calls it time-consuming non-
sense. For some reason, there
is a large number of oper-
ators that like mailbox soft-
ware programs that talk a lot
to the users of the system.
Our group here could care
less about chatting to the
computer; it seems to insult
their intelligence.

It is not the purpose of the
system to carry on a conver-
sation with a computer con-
trolling the mailbox system.

Our system was very sim-
ple—nothing fancy or ex-
pensive to maintain. The rig
consisted of an old 1950s-
vintage General Electric
VHF transceiver that had a
Flesher Corporation HF-144
on the receiver to give us
about a 30-dB gain for those
weak signals. It could trans-
mit 50 Watts all day long.
This rig had held my house
down during high winds for
many years, and it took the
better part of our backs to
remove it from my shack.
After we healed from the
hauling of the transceiver
we acquired a Radio Shack
TRS-80 Model I with 48K of
memory (and one disk drive
from Andy Anderson K0NL).
A single-density disk will not
hold very much data for a
mailbox system, so I pur-
chased a double-density
controller board and in-
stalled it into the expansion
interface of the TRS-60 I
had three ROM-116 inter-
faces (for some unknown
reason) and I donated one
for this interesting project,
along with the antenna.

Jerry Flesher K0TNC donat-
ed the location and a
TU-170A, It was all inter-
faced together and the final
tuning was done by Gene
Godsey K0BXJ

Well, everything seemed
to be running smoothly. The
ROM-116 and the Flesher
TU-170A ran flawlessly for
over a year. Then, Flesher
Corporation came out with
the TU-1200 terminal unit
capable of running at any
rate from 45.5 to 1200 baud.
Here is a terminal unit that
would do both Baudot and
ASCII and could be run at
the full output rate of the
ROM-116 system Up until
this point, we had been lim-
ited to the 300-baud maxi-
mum of the TU-170A.

The TU-1200 is a 1000-Hz-
shift terminal unit using
1200-Hz and 220CHHz tones
(Bell 202 compatible). The
TU-170A had been running
170-Hz -shift (2125-Hz and
2295-Hz) tones.

Okay, we could now get
our speed up. but there was
one minor problem of what
to do about the people still
wanting to use the 170-Hz
shift I wanted to have both
on the same system. It was
hardly worth two identical
systems just for faster baud
rates.

So, the problem was to
find a way of using both the
TU-170A and the TU-1200
on the same system without
sacrificing anything we al-
ready had, After trying sev-
eral circuits, a workable so-
lution to the problem was
found. By detecting the
space signal (2295 Hz) from
the scope output of the TU-
170AP we were able to make
the system work perfectly
normally for either terminal
unit

As shown in Fig. 1, the
space scope output of the
TU-170A is fed into the cir-
cuit through CI and D1 to
pin 4 on Lfl, A threshold pot
(PI) is used to set the sen-
sitivity of the input Time-
out delay is set with the
combination of R4 and C3,
and with the values shown,
the delay will be about 15

seconds. When a space sig-
nal is detected from the TU-
170A, U1 will trigger Q1 and
then pull in the relay. con-
necting all the necessary I/O
to the TU-170A. When the
circuit remains inactive for
the set time (determined by
R4 and C3), the relay will
then release and reconnect
the I/O to the TU-1200. The
TU-170A SEND-N (pin 9J
connects to the cmuit
board at pin 9 of U1 .md
also connects to one or t \e
relay contacts (non
open) of the relay. When ti
170-Hz shift is detected aroj
the relay is pulled in, the
PTT of the ROM 11b will
keep the input at U1 pin 6
constant and prevent the
circuit timer from timing out
and dropping the relay dur-
ing transmission.

A 12-V-dc DPDT n lay
with 5-Amp contacts is in-
stalled inside the ROM-116
and is used to make contact
with external PTT re<,uir«_
ments. The relay will k s a
common to the TUs and to
the transmitter PTT input
This was a must on our set-
up since the PTT relay inside
of the transmitter is >v
ered with about 30 v I ac,
and solid-state ctevi* d
not mix with ac too w. II
Some VHF and UHI rig*
may pull a lot of current on
the PTT inputs; the relay
would be the answer I ■ this
situation, too.

Adjusting the thn -huld
potentiometer (PI) of til- 6l
tector circuit can b*
by connecting a 2
tone oscillator to thi
input of the TU-17(J/v md
adjusting PI so th^; the
2200-Hz tone will not acti-
vate the relay. Touching up
on this adjustment n be
required in actual operation
at a later time. Power foi th
circuit and the relay ( b
obtained from the TU-1 . < IA
power supply, I built th ^r-
cuit up on a piece of I .by
perf board which can be
bought at Radio Shiitk
(along with most ol the
other components).

The TU-1200 is not jum for
the group that has 1200-

Magazine * November, 1964 51

baud capability, it is for any-
one that wants to use the
system from 45 5 baud to
1 200 baud. !f anyone wishes
to access the mailbox sys-
tem with a 17frHz terminal
unit it is no problem at ail.
Using 1200 baud sounds like
a buzz saw to those not fa-
miliar with the sound, and it
is impossible to read as it is
being displayed on the
screen. I can now get a long
picture or bulletin from the
system, save it to memory,
and print it out later, or save
it to disk. What used to take
forever (receiving text at 60
wpm (455 baud)), now takes
only a matter of seconds.

This circuit seems to be
very quick when switching,
so nothing seems to be nit
out The ROM-116 RTTY o|^
erating software has a did
die feature that can be set to
however many diddles you
desire I set mine for 10 did-
dles, and this seems to do
fine for even the 1200-baud
operation. There is a delay
due to the PTT circuit in

LEARM THE C

both the mailbox system
and my system. So, by the
time my transmitter drops
out and is ready to receive, I
may have missed part of a
word, However, I do not see
that this is a big problem. A
change can be made to al-
low for the delay in the me-
chanical relays in the soft-
ware.

We all got the word about
the FCC not requiring CW
identification every ten min-
utes while on RTTY. Now all
we have to do is give iden-
tification in RTTY Weil, the
following will tell you what
to change in order to do this
with your ROM-116 mailbox
system

The TRS-80 Models III
and 4 can use the patch utili-
ty to make the following
changes. The Model I will
have to use a utility such as
NEWDOS's SUPERZAP The
changes are as follows:
Model t Ver 1 .42 MBO
Address: 6D61 H
Find: D5 3A A0 83 21

Change to: D5 0 88 6D21

Models III and 4, Ver 3.4.2,

MBO

Address: 6DA9H

Find: 3A F5 83

Change to: C3 CF 6D

The exact patch format is:

PATCH MBORTTY/CMD:0

(ADD = 6DA9,FIND =

3AF583,CHC=C3CF6D)

While this fixes the pro-
gram so it will not send the
CW identification, it also
eliminates the only ID it has.
So, the following patches
will identify in RTTY what-
ever you have stored in buff-
er 6, such as "DE K0WVN
MAILBOX SYSTEM TOPE-
KA," Here are the necessary
patches:

Model I, Ver1A2MBO
Address: 57DBH
Find: 0A 00 C9 D7 0A

0A
Change to: 0A 00 C9 D7 0A

B6
Models III and 4, Ver 3.4 2
MBO

Address: 57A4H
Find: C9 D7 OA 0A 00

Change to: C9 D7 0A B6 00
The exact patch format is:

PATCH MBORTTY/CMD:
0 (ADD = 57A7,FIND =
0A.CHG = B6}

Model I, 1A2 MBO: Ad-
dresses 57CF, 635 D, 6379,
63 B4, 63 ED, 6418, 6454,
64AAH and 64F4; Find 4E;
Change to B6.

Models Ml and 4, 3.4.2
MBO: Addresses 5799,
63A4f 63C0, 63 FB, 6434r
645F, 649B, 64F1, and 653B;
Find 4E; Change to B6,

After these changes are
made, whatever you decide
to enter into buffer 6 to be
printed as an identification,
be sure to add a carriage re-
turn before entering any-
thing else in the buffer

This should give you a
super sytem, one that will
operate trouble-free for a
long time to come. Those of
you using a different termi-
nal unit can probably inter-
face it in the same manner
as the TIM 70 A with the
TU-1200. In any case, I hope
you have fun using the sys-
tem and the faster baud
rates!

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52 73 Magazine • November; 1984

Todd Enders WDWCl
PO Box 449
Minot ND 58702

Decode Soviet Space Messages

As you read this, mysterious signals are being beamed
into your shack. What do they mean? Where are

they coming from? Use WDQBQ's satellite-
telemetry reading program to uncover the facts.

You hear it on the high end
of 10 meters whenever
the RS satellites pass over:
RS5 K00 DOQ O00 GOO U00
WOO— the heartbeat of the
satellite, the telemetry
beacon, It provides a con-
stant stream of data about
the health of the spacecraft,
but what does it all mean? Is
there a way to figure it out?
Take heart, because I am
about to describe what the
telemetry means, the hard
way to decode it and a
much simpler way to de-
code St using a computer
(you do have a computer,
don't you?).

The telemetry provided
by the RS series of satellites
contains a wealth of infor-
mation about the operating
parameters of the space-
craft It will tell you every-
thing from the power output
of the transponder to the
ambient temperature, This
information gives you an
overall view of the health of
the system. It can also tell
you such things as how
much time the satellite is
spending in sunlight, or the
moment when the satellite
passes into or out of Earth's
shadow.

So why bother to take an

interest in this data? For one
thing, the telemetry tells
you if the transponder is

turned on. You can't make
contacts through the bird if
it's not listening. Also, you

can tell when the satellite is
on the decline and about to
fail. Besides, it can become

Frame Chan. Parameter

()/E

l/S

A/U

M/W

D
O

G
U

K
D
O
G
U
S
W
K
D
O
G
U
S

K
D
O
G
U

s
w

Output power of transponder

Voltage of power source

Load current

Telemetry test

Hermetically-sealed container

pressure

Temp, of stabilizing unit

Temp, of transmitter radiator

Output power of transponder

Zero-setting of telemetry mV meter

Output power of beacon

Repeater sensitivity control

S- meter for 1st service receiver

S-meter for robot receiver

S- meter for 2nd service receiver

Output power of transponder

9-V voltage at transponder

7.5-V voltage at transponder

9-V voltage at 1st stabilizer

7.5-V voltage at 1st stabilizer

9-V voltage at 2nd stabilizer

7.5-V voltage at 2nd stabilizer

Output power of transponder

Filling-out of robot log

Power of turned-on heaters

Power of robot transmitter

Power of service-channel transmitter

Sensitivity control for robot

transmitter

Sensitivity control for service-channel

transmitter

Unit of

Decoding

measure

formula

(N2)/5

0.2N

20 (100 -N

—

None

°C

°c

<N*)/5

—

{N*)/5

0.1 (N-1Q)

0.1 (N- 10}

0+1 (N - 10)

(N2)/5

0.1 N

0.1N

(N2)/5

QSO

N + 1

0.1N

20N

Note: The first frame identifier indicates normal operation. The second frame identifier indi-
cates that the satellite is being serviced.

Table 1. Formulas used to decode telemetry of RS-series satellites.

73 Magazine • November, 1984 53

an interesting diversion
from the ordinary operation
through the satellite.

OK, so there's some inter-
esting information there, but
how do you get it from K00
D00. . . ? Each character
specifies a channel of telem-
etry* A channel is a single
parameter such as the pow-
er output of the transponder.
The telemetry channels
are grouped into sets of sev-
en which are known as
frames. The frames are sent
sequentially, and there are
four possible frames in a full
set of telemetry data. From
one to four frames may be
sent by the satellite, depend-
ing on how the ground-con-
trol stations have config-
ured the satellite for the
day's passes. Frame identifi-
ers also change if the space-
craft is in service mode,
when the satellite is being
commanded by ground con-
trol, or if the transponder is
switched off to give the bird
a rest.

Now that you know how
the telemetry is sent how do
you go about decoding it?
There are two ways— manu-
al ly and by computer. Manu-
ally decoding the telemetry
has one advantage— it's
cheap. If you want to decode
it in this fashion, Table 1 pro-
vides you with the necessary
formulas to do it yourself.

Decoding telemetry by
hand is a relatively easy exer-
cise, but it's kind of boring.
Face it you probably have
better things to do than fig-
ure out values from equa-
tions. It's really kind of dry.
Well, thanks to technology,
you don't have to slave over
those formulas. The comput-
er revolution has set you
free. If you have a program-
mable calculator, you can
program the formulas into it
and ease the pain somewhat
Of course, you still have to
look at the tables to assign
some meaning to the num-
bers you get from the formu-
la, But if you have a comput-
er, it can do the work for you
and even label the results.

Listing 1 shows a program

30
40

3®

70}
8©

i 1171

140
150

L7G
ISA
198

£3$

£40
259
360

£60

310
32 0
330
340
350

360

370

380

390
400

410

4c: 0

4 3©
440
450

480
470

480
490

S00

510

5£0
530
54©
550
5G0
370
580
530
60®
610
6E0
£30
640

650

£6*i

Listing 7. Program to analyze and display RS-series telemetry.

RS satellite telemetry decoding proqram V 1.0 by Todd Ender*5 WDOBCI

This program decode telemetry data for the

of amateur satellites.

soviet RS3 throuah RS8 seriei

clear screen and display header and prompt for frame id

KEY OFF

CLS: LOCATE i, £ft: PRINTERS 3~B Satellite Telemetry Decoder31

LOCATE 3, 5: INPUT" frame ( none, E, I, 5, ft, U, M, W) M:FR*
i

1 oromDt for telemetry channel data
*

•i

LOCATE 5, 10:PRINTUK: ji

LOCATE 6, iCi:PHINT"D:M

LOCATE 7, 10:PRINTuOs "

LOCATE 5, 10: PRlNT"Gs11

LOCATE 3, 10:PRINT"U: u

LOCRTE 10, 1&:PRINT"S;M

LOCATE It, 10: PRINTS s "

LOCATE 5, 14s INPUT Kb LOCATE 6,14:INPUT D : LOCATE 7, 14:TNPUT 0

LOCATE 3, 14; INPUT Bi LOCATE 9, 14: INPUT U : LOCATE 10, 14: INPUT S

LOCATE 1 1,14s INPUT W

1 determine which frame km calculate data for

IF FR*="" OR FR$-"E" OR FR$=lle1t GOTO 450

IF FR$="i" OR FR* = "I1' OR FRt^'S" OR FR* = "5" GOTO £fl©

IF FR$="fl" OR FR*="a" OR FR$="UM OR FR*-,lu" GOTO 910

IF FR*=MM" OR FR$="fflM OR FR*™1^" OR FR$B="w" GOTO 1160

SO TO 130
t

'calculate data for base frame/E frame parameters

EK~KA a J 5 : ED™ . 2*D : EO^S0* i 1 00^0) s EB-G : EU=U : ES=S s EW=W
t

'display data for base frame/E frame

CLSsLOCATE 1, £0 ; PRINT "Channel C )/ (Ej telemetry parameters:11

LOCATE 5t 10BPRINT"Oijtpi.it nower of t ransponder; ";: LOCATE 5,5@:PRINT EKrM mW"

LOCATE &, 1<3: PR INT "Vol tape of power sources " s LOCATE 6150tPRINT ED;" V"

LOCATE 7, 10: PRINT"Load current s " :LOCATE 7, 5<3:PRINT EQ : " mfl"

LOCATE S, 10: PRINT"Te lemet ry test :": LOCATE 8,50:PRINT EG

LOCATE g, 10: PR INT" Hermet ical ] y sealen container crassur^:15

LOCATE 9, 50s PRINT EU

LOCATE 10, J0:PRINT"Temp. of staqi 1 i z ir.g ur.it : M s LOCATE l«a,50 = PRINT ES;" C"

LOCATE 1 1 , 50 : PR INT EW ; " C "

LOCATE 1 1, 113: PRINT" Temp, of transmitter radiators"

LOCATE £4. 10: PRINT11 ores^ any key to cant irate" 3 : .fl*™INKEYt : IF Q**'1 V GOTO Bid

6QT0 130

calculate data for 1/S frame telemetry parameters

that accepts telemetry data
and converts it to human-
readable form, It is written in
Basic for the IBM Personal
Computer but can be read-
ily converted to run on other
machines by anyone who is
familiar with Basic.

The program prompts
you for the frame identifier
of the telemetry data, and
then for the numbers follow-
ing the channel identifier.
The computer will calculate
the values for each of the te-
lemetry channels and print

the corresponding values,
all nicely labeled, on the
screen for your examination.
This can be repeated for as
many frames of telemetry as
desired.

After studying the pro-
gram, you might wonder
why I didn't include any rou-
tines to provide hard copy
of the results of the teleme-
try decoding. The simple
fact is that on the IBM PC
these routines are not need-
ed since there is a key on the
machine that allows you to

dump the contents of the
display to the printer. If you
are adapting this software to
another system, it is a simple
matter to write the neces-
sary routines to provide
hard copy, or to replace ap-
propriate PRINT statements
with LPRINT (or whatever
your particular system re-
quires).

Now that you can under-
stand this data, what can
you do with it? For starters,
try graphing load current on
a pass-by-pass basis for sev-

54 73 Magazine * November, 1984

£70
£B$

IK=K 2/5: ID=D: 10=0 £/5: IG=G:IU=. l*(U-i0> : IS^. 1#*S-1B> s IW=. 1*(W-I0>

70«
710

730
730

750

760
770
780
730
300
Bt0
&B$
a30
340
aS0
87tf
830

300

310

920

330
3i,0

950
360
370
98tf

990

1000
1010

1 020
1030
1040
1050

J0£0
1070

10B0

1091?

.1 J 00

11 10
1 J

1130

1 1 A0

1 1 riti

€0

1 170

use

1 190
1300

,tei0

1330
t£4«

i£50
1££0
1270
lc'80
1290
1300
1310
1380
1330
1340

1 display data for 1/5 frame telemetry

CLS: LOCATE I, £0c PR I NT "Channel (I>/(S> telemetry parameters 3 "

LOCATE 5, 10sPRlNT"Oatpnt power of t ransoonder : " s LOCATE 5f50:PRINT IKs" fiiWM

LOCATE &+ 10;PRINT"2erQ setting of telemetry mW meter s ": LOCATE 6,50sPRiNT ID

LOCATE 7t l0:PRINTl,Output powe^ of beacon :" iLQCflTE 7,50:PRINT 10;" mW"

LOCATE a, 10: PR I WTM Repeater sensitivity cont *^ol ; " s LOCATE fi, 50: PR I NT IB;" dB"

LOCATE 9t 10: PR INT" 5-meter fo*r 1st service receiver:"

LOCATE 3, 50: PRINT" S- " ; I U

LOCATE 10, 10iPRINTJ(S-meter for ROBOT receiver:" jLOCfiTE 10, 50s PRINT'* S- "MS

LOCATE 1 1, 10: PRINT* 3— meter for end service receiver:

LOCATE 11, 50: PRINT" S- " t IW

LOCATE £4, 10: PRINT"press any key to cent inue" ; : A*=INKEY* s IF At=M" BOTO B40

GOTO 130

calculate data for ft/U frame telemetry parameters

AK-K £/5:AD=. i*DiG0=0*. 1:AG=. l*GiAU=, 1*U;AS". t*S:AW=. L#U

T display data for A/U frame telemetry

CLS: LOCATE 1,

LOCATE 5, 10: P

LOCATE 6, 10: P

LOCATE 7, 10:

LOCATE a, 10:

LOCATE 9t 10:

LOCATE 9,50:

LOCATE 10T 10

LOCATE 10,50

LiCQTE 1 1* 10

LOCATE 11,50

LOCATE c'4, 10

GOTO 130
i

£0: PRlNT*'Channel (A> / fu) telemetry parameters! '1

RINTnautput power of transponder i" jLOCATE 5f50:PRlNT AK ; M mwM

RINT,P9 V voltage at transponder : " sLOCftTE 6, 5ti = PRINT AD ? ,L V"

PR INT "7- 5 V voltage at transponder s ": LOCATE 7, 50: PRINT AO;" U"

PR I NT "9 V voltage at 1st stabi 1 izer; " : LOCATE &, 50: PR I NT AG;" VH

PR INT "7,5 v" voltage at 1st stabiilzers"

PRINT AU;" V"

:PR1NT"3 V voltage at and stabilizer;"

: PRINT AS;" v"1

:PR1NT"7. 5 V voltage at 2nd st abi 1 l zer : M

: PR I NT AW;M V"

: PR I NT "press any key to cont inue" ; : A*-1NKEY* i IF A$=,l,t GOTO 1080

calculate M/W telemetry parameters

HK=K 2/5sMD=DiM0», i«^:MG=20*GiMU=£0#U;MS=S:tfW=W

' c;i5olay data for M/U telemetry frame on screen

CLS; LOCATE 1

i_0CATE
LOCATE
i_QCAT£
LOCATE
LOCATE
LOCATE
LOCATE
LOCATE
LOCATE
LOCATE
LOCATE

5, 10:

£. 10:

7, 10i

8, 10:

9, 10:

9, 50:

10, 10

10,50

11, 10

1 1 , 50
£4, 10

, 20: PR
PRTIMT"
PRINT"
PRINT"
PRINT"
PRINT**
PRINT

= PR I NT
sPRINT
: PRINT
: PRINT
: PRINT

INT "Channel tMl/CUi) telemetry parameters:*'

Output power of transoonder; " : LOCATE 5, 50: PRINT MK ; " mW"

Filling out of ROBOT 050 log; ": LOCATE 6, 50: PRINT WD

Power of turned-on heaters a" tLOCATE 7f50:PRINT MO;"

Power of ROBOT t ransmitteri "; LOCATE fl(50:PRINT MB|"

Power of service channel transmitter;"

MU;M mW"

"Sensivity control for ROBOT transmitter:"

MS;" dB"
"Sens, control for serv. char, trans* ;";

mW;M dB"

press any key to cont inue" | ; A*- INKEY* : IF A*=

u it

BOTD 1331?

GOTO 130

eral passes. Look for a long-
term trend I have suggested
this exercise because load

current varies with such
things as transponder load
and the input power of each
user into the satellite. It is
probably the most variable
of the telemetry data and
usually shows changes more
readily than any of the other
parameters.

Voltage at the power
source is also an interesting
parameter to watch. It can
indicate a satellite-damag-
ing condition such as bat-
tery overcharge (usually
fatal if prolonged or exces-
sive), If the voltage suddenly
changes, it is a good bet that
the satellite has passed from
daylight into darkness or
vice versa. Most of the pa-
rameters are worth watch
ing for long-term changes
{monthly, seasonal, etc.). It
can grow into an interesting
pastime, much like keeping
weather records. You can
also pass the data along to
AMSAT They are always
looking tor telemetry infor-
mation from amateur satel*
tites.

Now that you are able to
decode RS telemetry, try lis-
tening to the satellites on
29.500 and 29450 MHz CW.
You can do with it what you
want, but in any case, have
fun with the program and
the data that you can obtain
from it. You might even get
more out of playing with the
telemetry data than working
people through the satel-
lite! ■

LBVHF-UHF Repeaters

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PHONE 21M36-6Q51

73 Magazine • November, 1984 55

The End of the Line

What's the point in sending power up the coax if it never

reaches the antenna? These tips on connector installation

and care will help maximize your station's signal.

Fred R. Cook WB5LBI
203 Spencer Orive
Lafayette LA 70506

As supervisor of automa-
tion and communica-
tions systems on offshore oil
platforms, I have learned
that the following methods
and materials produce long-
lasting results even in saft-
spray conditions on motor
vessels and oil platforms in

the Gulf of Mexico If care is
not exercised initially, mois-
ture and improperly sol-
dered coaxial rf connections
can yield undesirable opera-
tion of your antenna system.

Cable Preparation

Proper soldering of the

RG-8 shield to the barrel of a
PL-259 coax connector can
be accomplished by tinning
the braid as shown in Photo
A. Tin the circumference of

the braid in an area that will
be under the solder holes in
the connector. Tinning must
extend well forward of the

solder holes to allow knife
cutoff of braid and center
insulation as shown in Photo
B. Cutting through the sol-
dered portion of the braid
requires a sharp knife and
considerable pressure Work
around the cable using a
rocking motion of the knife
blade rather than site ing.

Place the knurled connec-
tor nut over the coax with
the threaded portion facing
toward the prepared end
Apply a small amount of sili-
cone grease or petroleum
jelly to the black outer insu-
lation and thread the con-
nector onto the coax. Make
sure the tinned area is in full
view in all four holes of the
connector and that the cen-
ter conductor is in view for
soldering.

Photo A, Tin the braid in an area under the solder holes.
56 73 Magazine * November, 1984

Photo B. Use a sharp knife to cut through soldered braid and
insulation.

Photo C Soldered connector with all holes filled. Use plenty
of heat

Solder the Connector

Soldering must be done
with enough heat to se-
curely bond the coax shield
to the connector. At least a
10OWatt soldering iron or
gun rs required to apply the
necessary heat. Inadequate
heat is responsible for most
coax-connector problems.

Apply heat and then sol-
der to each hole of the con-
nector Go from hole to hole
around the connector with
heat and solder When the
connector has absorbed
enough heat, solder will
freely flow into the holes
and bond with the shield. It
may take two or three
passes in quick succession
to achieve this. Next, solder
the center conductor and al-
low to cool. The finished sol-
der joints should be smooth
and shiny — no solder beads
or dull rough areas. See
Photo C

Now that your connec-
tors are properly soldered, a
check must be made to en-
sure that no shorts between
the center conductor and
shield have been created. A
volt/ohmmeter, set on the

10k-Ohm range or higher

and connected between
center pin and body of the
connector, should indicate
infinite resistance if all is
okay.

Protection Is a Must

Rf connectors used outside
and exposed to the weather
must be waterproofed to
efiminate corrosion. Corrod-
ed connectors contribute to
elevated swr and can radi-
ate rfcausing TVI A simple
layer or two of vinyl electri-
cal tape will not provide the
necessary weather protec-
tion! The following method
is used by radio technicians
installing antenna systems
in the Gulf of Mexico and
can easily be applied by am-
ateurs, I have used this
method for eight years with
no corrosion problems.

3-M Scotch® product num-
bers will be referred to, but
other manufacturers' prod-
ucts are available to yield
the same results,

Seal the Connector

The plug and receptacle
portions of the connector

must be joined firmly to pro*

Photo D. Apply rubber tape with tension to conform to the ir-
regular shape of connector.

vide a good electrical con^
nection. The connector is
now covered with a layer of
Scotch No. 23 rubber splic-
ing tape. Remove the pro-
tective backing and start
wrapping 1/2" ahead of the
connector on the coax.
Stretch the tape at least
twice its original length as
you wrap, overlapping half
the width of the taper and
continue the length of the
connector Be careful to fill
voids and make the tape
conform to the shape of the
connector as in Photo D.
This tape is both cohesive
and adhesive and forms a
solid covering.

A layer of Scotchkote®
electrical coating is now ap-
plied liberally over the rub-
ber tape for a sealer. See
Photo E. This is a fast-drying
liquid and imparts a water-
proof seal, I have also used
this type of sealant on
bolted rf connections on an-
tennas It will coat the bolt
and nut to retard corrosion
and will allow removal of

parts later. When the coat-
ing is almost tack free, start
a layer of Scotch No.88 vinyl
electrical tape on the coax
just ahead of the rubber
tape The tape should be ap-
plied firmly with a slight
amount of stretch. Continue
down the connector, over-
lapping about half the tape
width to the endr and then
return in the opposite direc-
tion to the beginning The
fast two wraps back at the
beginning should be made
with very little tension to-
avoid tape unwrap. Finally,
one last coat of Scotchkote
will seal the vinyl tape from
moisture. Your finished
product, in the case of a line
splice, should look tike
Photo F.

This method should be
used on all antenna connec-
tors whether they be coaxial
or coaxial cable terminated
with screws and lugs Also,
many hams provide a splice
connection at the tower to
allow "fold-over." This splice
should also be protected ■

Photo £. Coat rubber tape with electrical sealer.

-n *

•u *

.%.m 4 * '

Photo F. Final covering of vinyl tape with outer coating of
electrical sealer,

73 Magazine • November, 1984 57

A Useful Present You Can Build

How about a high-tech holiday gift?

Richard A Need WB4 YOD/PW8ZAF

Bon 248

Waxhaw NC 28173

CP129

789QQ Porto Velho, RO
Brazil

Learning new technology
can be a painful experi-
ence and breaking into digi-
tal electronics on your own
can be positively frustrating.
That is why I decided to get
some help in my attempt to
update to digital electronics
and enrolled in some classes
at San Diego City College
(Yes, California does have
more than surf and sun!) By
the end of the first semester
I had learned a little, so I de-
cided to combine the final
laboratory project with my
need for a Christmas gift for
my wife. Since wives don't
always appreciate elec-

tronic gadgets, I felt I should
come up with something
she would consider practi-
cal without attempting

something that would be
too difficult

Happily, my wife likes to
cook. And, conveniently,
her old-fashioned kitchen
timer had recently failed.
The obvious solution was to
build her a kitchen timer
(eminently practical) using
digital circuitry; as required
for the lab project. I decided
this timer would not need to
display seconds, nor would
it require greater than 60
minutes capacity. Its alarm
should be audible for 50 feet
in a normal house [whatever
that is) and its display
should be visible for 20 feet
so it could be seen across a
normal kitchen. Battery op-
eration would be conve-

PQWEP
AND

■

CLOCK

rnuMTCD

EH SPLAT

vUvn < t "

Al A»U

Fig. 7. Timer block diagram.

58 73 Magazine • November, 1984

nientr and I decided to lay
out the controls for a left-
handed user since the cook
in my house is left-handed.

Theory

The timer is built around
an up/down counter driving
a seven-segment LED dis-
play, as shown in Fig. 1. The
counter is set by clocking it
up using push-button
switches in the control sec-

tion and is clocked down by
a one^pulse-per-minute sig-
nal from the clock. The
alarm, which is triggered by
the counters zero count, is
modulated by signals from
the clock so as to reduce
current consumption yet
achieve the required audi-
bility. The control section in-
cludes an automatic power-
disconnect circuit to pre-
vent draining the batteries

SET
CONTROL

SET TENS SET UNITS

IHJ (HI

jti

L|4 a

TCIv

[I i

pa pp pc pe pa

CPU
74LSI9 3
TCC CPO

MB qp Ql qj 03

ftf

I t

TENS B-C-D
OUTPUT

TiWER

C0WTH0L

(H)

UNITS 6-C-O
OUTPUT

Fig. 2. Counter logic diagram.

by inadvertently allowing
the alarm to sound exces-
sively.

Circuit Description

The counter, shown in Fig.
2, utilizes two up/down bina-
ry counters in cascade. The
units display requires a full
decade, so a 74LS192 is suit-
able. The tens display re-
quires only 0 through 6, so
its counter is preset to zero
by count 7 so that the timer
cannot be set to more than
60 minutes. Using a
74LS193, whose count se-
quence includes 0 through
15r and wiring the preset
gate, U4ar to force preset
when the Q(pQ2 outputs are
all high will cause preset on
count 7 or count 15. The
counter will then be forced
to operate between 0 and 6
as it cannot be clocked up
beyond 6 or down beyond 0.

U4b is wired as a preset
gate to force the units
counter to zero when the
timer is being set and the
tens counter is at 6. This es-
tablishes 60 minutes, rather
than 69, as the maximum
timer capability. U4b is dis-
abled in Timer mode when
the Set control line goes low
so as to allow the units
counter to be clocked down
normally. Otherwise the
units counter would be
locked at zero by the tens
counter's 6, preventing the
application of clock pulses
to the tens counter locking
the timer at 60.

R7, R8, and R9 are pull-
down resistors for the inputs
of U4b. This was found to be
necessary in order to pre-
vent presetting on the 6
count due to "racing." Evi-
dently, between count 5 (bi-
nary 0101) and count 6 {bina-
ry 01 10), Qq was not going
low before Q-| went high, so
the preset gate interpreted
the 6 as a 7. The pull-down
resistors cured the problem.

All clock lines must be
held low when switching
modes in order that their as-
sociated NAND gates be dis-
abled. This will hold the

clock inputs to the counters
high during mode changes,
thus preventing spurious

clocking when switching
modes.

The 74LS192/LS193
counters are designed to be
cascaded by connecting the
TC output of one directly to
the CP input of the next
U3b, the Mode gate, inverts
the TCq signal before it
reaches the CPp input of the
tens counter, so an inverter
must be included in the sig-
nal path to restore the prop-
er polarity. Without the in-
verter, the count is 50, 59,

58, etc

Fig. 3 shows the wave-
forms of the counter in Tim-
er mode with the units
counter clocked by a sym-
metrical square wave whose
period is 1 second. The Q
outputs of the 74LS192/LS193
change states on the low-to-
high clock transition. The
TCq output goes low with
the low portion of the clock
pulse when all its Q outputs
are low. In Timer mode,
counting down, the binary
output of the units counter
changes to 0000 with the ris-
ing edge of the 0 clock
pulse. The tailing edge of
that pulse, 30 seconds later,
causes the units TCq to go
low. 30 seconds later, the
clock pulse again goes high,
clocking the units counter
to its 9 count and forcing the
TCp back to its high state.
As the units TCp goes high, it
clocks the tens counter

+ 5V0C

(OK

2ZK

-CI

I0H*

ill ;4

DIS TtilG

356

T* Ol/T

•HO COUT

Digital kitchen timer in use

3D »: — j

r FROM
CLOCH '

10 ..c

UNITS

COUNTER

°°i — i i — l_i — i r — i r

03 r

.£ p..*

— «

L ™f

*4 k-

TENS

COUNTER

TCD

FROM * « I J ■
UNITS l

IF \P \P IT If

Of I
I
I

-L

02 I

to «■■

Tea l

VHCRE BEADS
•0

~E = E **E*0S A.J. u
-TRIGGERS alarm - - ' : i

Fig. 3. Counter waveforms,

(HI

IN S 3D

74LS9C

•91 i i 04

*I0
«4IJ!I mi

■04 i 1 SQi

.OUF

m B on

74LS9G

■41 I I

-a

I 1 MQ'.Z-

\H A QQ

T4t*92

-12

iff a qa

notn roc?]

sirr CONTROL

Iff)

I PULSE
PER MIN

Fig. 4. Clock-generator logic diagram.

73 Magazine ■ November, 1984 59

Parts List

Capacitor, tantalum, 2J uF

$ .60

C2, C4-7

Capacitor, disc, .01 uF

.20

Capacitor, tantalum, 47 uF

Capacitor, tantalum, ,1 uF

,50

LED, red

.30

1&*pin DIP socket

.45

2*pin socket

.50

Relay, 5-V coil, Radio Shack 275-243

2.50

16-pin DIP plug

170

2-pin plug

.50

Resistor, 10k, 1/4 W

.03

Resistor, 22k, 1/4 W

.03

Potent iomenter, 1k, Radio Shack 271*333

,50

Resistor, 1 M, 1/4 W

.03

R5, R7-9

Resistor, 330 Ohms, 1/4 W

.03

Resistor array, 5x 1k( Radio Shack

271-096

.90

Switch. PB, DPDT (push-on/pushoff)

2.00

S2, S3

Switch. P8, SPOT (momentary)

1.60

U1 74LS192

U2 74LS193

U3,6,7, 13 74LS00

U4
U5
U8

U9,U10
U11
U12

U14, U16
U15, U17

74LS20

74LS04

LM556

74LS90

74LS92

74LS02

74LS48

Seven-segment, common cath. display

(MAN 74)
U18 + 5-voit regulator, LM340T-5 (7805)

Piezo sounder, Radio Shack 273*060
Battery holder, 4 x AAcell
Enclosure
Grid board, 2 pieces 2-3/4" x 3-3/4 '\ Radio Shack 276*161

IC sockets, solder-in (optional), 18 required
(Prices as of January. 1984)

.95
.95

.38

1.50

.66

.38

1.10

1.60
1.60

3.00
1.00

5.00

3.00

.45

The BCD output from the
counter section drives the
seven-segment display de-
coders. Besides the 74LS48
decoders and the MAN-74
displays, the display section
also includes a single LED
which is driven by a 1-Hz
pulse from the clock to
serve as a Timer mode in-
dicator

The alarm section con-
sists of a Radio Shack piezo

sounder and appropriate
gating. The Set control line,
Q0-Q3 from the units count-
er, and Q0-Q2 from the tens
counter must all be low in
order to enable the alarm.
When enabled, U6c holds
the sounder's positive lead
high The sounder's negative
lead is connected to a
NAND gate/inverter combi-
nation that combines a 1-Hz
square wave with a 10-Hz

MULTIVIBRATOR
OUTPUT (UBEO

1 r

inIi

IQO-1

square wave. When these
signals are both high, the
negative tead is held high
and the sounder is off. When
either signal is low, the
sounder will be energized.
The result is a tone of about
5 kHz that is keyed at a 1-Hz
rate and modulated at a
10-Hz rate.

The timer requires clock
signals of 1 pulse per minute
to drive the counter, 1 pulse
per second the key the
alarm, and 10 pulses per sec-
ond to modulate the alarm.
These signals are produced
by a divider chain driven by
an astable multivibrator, as
shown in Fig. 4. The multivi-
brator output is a nonsym-
metrical square wave whose
high time, t|f is 60 ms and
whose low time, 12, is 40 ms.
The period, t-j + t2, is 100 ms
and the frequency is thus 10

i r

DIVIDE -

B.T-IO

in [runji_runrijnji_rij^^

t* MO *1 m\m ■ — * 1O0 m \ m\

OUT J

DIVIDE -

OUT

■a Mt-

J L

J 1

DIVIDE
ST-I2-
(UH)

, -

1**

!_n_n_n_n_n_n_n n_n_n_n_n

1 : u :

-»

10*(«

OUT

Fig. 5, Clock waveforms.

60 73 Magazine » November, 1984

Hz. These times are deter-
mined by the following rela-
tionships: t| = 0 693 (R] +
r2) C\; t2 = 0.693 X R2 X
G|. The 10-Hz signal from
the multivibrator is used to
modulate the alarm as well
as serving as the input for
the divider chain. The 1-Hz
signal from the divide-by-ten
stage is also applied to the
alarm. When the Set control
high, in Set mode, the

'IK

SET TENS

SET UNITS

TIMES SET

MODE

■

74LS92 and the first 74LS90
will be disabled by the high
applied to their R^ inputs
and the clock output will be
held low. As mentioned pre-
viously, this is necessary to
prevent spurious clocking
when switching modes. Fig.
5 illustrates the clock-gener-
ator waveforms.

Power from four AA cells
is applied to the circuit

SE7

T 1 V SET

p • CONTROL

.__ j — I / CHI

t 1 wen

CONTROL
(Hi

-tv OuT| 5 VOLT

-4 L*

TCD fVQU
TEMS COUNTER

Fig. 6. Power and control logic diagram.

1HA1M BOARD I

TttCD *5€f

Fig, 7, Timer schematic diagram.

through normally-open re-
lay contacts, as shown in
Fig. 6- Placing the timer in
Set mode applies power to
the circuitry, providing a
path to ground for the relay
by energizing the monosta-
ble multivibrator. The relay,
once energized, latches
power to the circuitry even
though the mode switch is
moved to Timer. The posi-
tive transition of the last 0
pulse from the clock drives
the counter to all zeros, trig-
gering the alarm. 30 seconds
later, the clock's 0 pulse
goes low, causing the units
TCp to go low. When the
units TCo goes low, the tens
TCp is driven low. The low
TCp from the tens counter,
which comes 30 seconds
after the alarm sounds, trig-
gers the monostable multivi-
brator This drives the multi-
vibrator output high, caus-
ing the relay to open, which

provides the automatic
shut-off feature after a
30-second alarm period. The
period of the multivibrator,
determined by the resis-
tor/capacitor combination,
is not critical as long as it is
sufficient to allow the relay
to open.

Push-button switches, de-
bounced by NAND gates,
are provided to permit set-
ting the two counters indi-
vidually. These are wired so
as to hold the Set lines nor-
mally low to prevent spuri-
ous clocking when changing
modes. Mode control is pro-
vided by an R-S flip-flop cir-
cuit controlled by contacts
on the push-on/push-off
mode switch. The mode-
control signals, which are
active high, are thus guaran-
teed to be complementary

Construction

The timer is constructed

in two units so as to fit a rel-
atively compact enclosure,
as indicated by the Main
board/Aux. board divisions
on the schematic diagram
(Fig. 7). The main circuit
board, shown in fig. 8, in-
cludes the clock, the count-
ers, the alarm gating, and
the Timer indicator LED.
The auxiliary circuit board,
shown in Fig. 9, includes the
control switches, the digital
display, the piezo sounder,

the battery pack, and the
voltage regulator. These two
boards are interconnected
by means of a 16-conductor
flat cable through J1/P1 and
a 2-conductor cable through
J2/P2; Though indicated to-
gether on the schematic, the
decoupling capacitors (C5,
C6, and C7] are spread out
along the IC power bus.

I housed the timer in a
black plastic case I chanced

UIZ

— V

~C_£3_-

Fig 8. Main circuit-board layout

73 Magazine ■ November, 1984 61

(0 I

(b) I

Fig. 9. Auxiliary circa it-hoard layout

upon in a local surplus-elec-
tronics store, which is the
reason for the strange shape
of the circuit boards. The

front panel is a red Plexi-
glas™ sheet through which
the display is clearly visible.
The controls have been ar-

te i

(r^~ — ^^

o °

i 1 I 1
f_l J_I

«==^ a ,-==:

H H O

Ibl

Fig. 7ft Kitchen-timer views

ranged on the left side so
that a left-handed cook can
operate the timer without
blocking the view of the dis-
play. The completed timer is
shown in Fig. 10.

Conclusion

The timer has proven to

be quite convenient to use
Pressing the mode switch
latches the timer in the Set
mode, allowing the user to
clock the display up to the
desired setting using the Set

push-buttons. Setting the
timer beyond its upper limit
of 60 minutes returns it to
zero, so setting errors can be
corrected. Pressing the
mode switch a second time
releases it and places the
timer in the Timer mode, A
flashing LED indicates that
the timer is functioning In
this mode The LED display
is visible for a distance of 20
feet except in very bright
light. When the display
reaches zero, an alarm
sounds for 30 seconds, then
the timer automatically
turns off. The alarm is audi-
ble for a distance of 50 feet
through several rooms in a
house with carpeted floors

Current drain from fresh
batteries was measured as
less than 150 mA, so battery
operation is practical for oc-
casional use I have found it
necessary, though, to install
an ac adapter because my
children like to play with
Mom's kitchen timer —
which suggests ideas for
next Christmas! ■

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62 73 Magazine * November, 1984

2300 MHZ MICROWAVE DOWNCONVERTER

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$06 List of Advertisers on page 88

73 Magazine ■ November, 1984 63

—

Dennis Fait WD8BHH

POBox22

Shppery Rock PA f 6057

Ham Over Fist

Here's a VIC-20 CW program with a twist: Its real-time display

lets you watch your dits and dahs dance across the screen.

But be forewarned — you may not like what you see!

10 REM

CM BANNER PROGRAM VIC-20 VERSION

BY DENNIS C, FAIT
PO BO* 22
SLIPPERY RDCKfPA

30 REH

40 REH

50 R£H

60 REM

70 REH

80 PRINT H CCLR) "

90 REM RESERVE SPACE FOR MACHINE LANGUAGE PROGRAM

100 REM AND CHARACTER GENERATOR

110 POKE 52, 26: POKE 56,24

120 REM TURN UP VOLUME

130 POKE 36870, 15

140 REM FILL ONE LINE ON SCREEN

150 PRINT "O0 DOWN>eABCDEFGHIJKLMNOPl3RSTU"

160 REM PUT CHARACTER GENERATOR AT 7 1 6SD

170 POKE 3&B69,255

1S0 REM CLEAR CHARACTER GENERATOR WITH NULLS

190 FOR fc-7168 TO 7679;PD*E X,0;NEXT

200 AO=6630;REM BEGINNING ADDRESS OF ML PROGRAM

210 READ BMF B~999 THEN SYS 6630

220 POKE A0,B;AD=AD^1

230 GOTO 210

240 REM

250 REM

260 DATA 32,91,26,162,0,160,23,136,240*47

270 DATA 189,0,28,24,42, 144, 20,32, 73f 26

280 DATA 189, 0t28, 56, 42, 157,0,28,32,82

290 DATA 26,32,82,26,76,237,25,32,73,26

300 DATA 189,0,28,24,42,157,0,20,32,82

310 DATA 26,32,82,26,76,237,25,32,106,26

320 DATA 173,9,144,201,235,208,16,173,176,28

330 DATA 56,42,141,176,28,169,225,141,12,144

340 DATA 76,230,25,173,176,28,24,42,141,176

350 DATA 28,169,127,141,12,144,76,230,25,202

360 DATA 202,202,202,202,202,202,202,96,232,232

370 DATA 232,232,232,232,232,232,96,32,159,255

380 DATA 32*228,255, 201,0,240,3, 141, 105,26

390 DATA 96,0, 138,72, 152,72, 174, 105, 26t 160

400 DATA 235, 136, 206,253,202, 208, 248, 104, 16a, 104

410 DATA 170,96

420 DATA 999

430 END

Listing 7. VIC-20 Basic-language CW Banner program. The
program initializes the screen and various memory pointers
and nulls the new character-generator table before poking
the machine-language program into memory. Execution is
then transferred to the machine-language program.

64 73 Magazine • November, 1984

Did you ever wonder just
what your CW fist
sounds like? I'm sure some
of you have had a friend
tape-record your signal from
the air, but have you ever
seen your fist? ("Why, of
course/' you answer. "Now
do you want to feel my
fist?")

Before you get hostile,
please let me explain the lit-
tle program in this article.

My CW Banner program
is written for the unex-
panded Commodore VIC-20
computer and will display
on your television screen
the dots and dashes re-
ceived by your HF rig. As a

(a}

bonus, it will do it in high-
resolution graphics.

What you'll see when you
run this program is a series
of dots and dashes appear-
ing on the right side of the
screen and smoothly mov-
ing across the screen to the
left side. As more elements
appear on the right, older
elements will disappear on
the left And that isn't all:
The VIC will also beep the
television audio in time with
the dots and dashes,

This program can be a
useful tool also for deaf
hams who still want to work
with dots and dashes and for
displaying other TTL signals
(with certain timing re-

3VTE 3

BYTE 2

"A*1

aVTE 1

■fi-

i jo

1
0

til

IZI

<■]

15]

1*1

(to)

1 1°

(

•1

Fig. h Example of how the first byte of each 8-byte character
definition in the character generator is modified to roll dots
and dashes to the left.

straints on the top end).
Fist still curled, you ask,

"Well, how do we do all of

that?"

I'm glad you asked.

Program Explained

To get the resolution we
want from the VIC, we must
change its character-genera-
tor pointer to point to RAM
instead of ROM and then
dynamically change what is
in that RAM to define the
dots and dashes we wish to
see,

The ROM character-gen-
erator table contains eight
bytes for each character
that the VIC is capable of

displaying. Each of the eight
bytes defines one line of
eight pixels in the 8 x 8
character grid The table be-
gins with the @ character
and then continues with the
alphabet, numerics, and
graphic characters.

All we need to do is rede-
fine one line in each of the
first 22 characters in the
RAM character generator
(@ through U), setting a bit
if a CW signal is present and
resetting it if there is no
signal

Take a look at (a) in Fig. 1 .
This represents a simplified
screen only three characters
wide which 111 use to ex-

plain what the program
does. Our three characters
on the screen are @, A, and
B. The program looks at the
most significant bit (MSB) of
byte 2. If it is low (1 ), then it
resets the least significant
bit (LSB) of byte 3 (2). If byte
2's MSB is high, then the LSB
of byte 3 is set. In either
case, the byte is then rotated
one bit to the left and poked
back into the character-gen-
erator table in RAM, The
program then skips to the
next byte, byte 1, and does
the same thing (4 and 5). The
POTY pin of the joystick port
is then checked for a signal.
If it is low (indicating a sig-

nal is present), the LSB of
byte 1 is set, otherwise it is

reset (6 and 7). Byte 1 is ro-
tated left and poked,

I should remind you that
the bytes we're messing with
above are the first of the
eight bytes that define each
character. The other seven
bytes were previously nulled
by the Basic program and
are not used. They remain
transparent so that the only
things visible am the dots
and dashes that are defined
by the first byte

In Fig. 1, (b) shows the
screen after the dots and
dashes have been moved to
the left by one pixel.

M55 ONE

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lit

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RTS
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NTS

PHA
TtA
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LDVl

BNE
DEI
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FLA
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LASICHAF

LASICHAR

Iff

Cr.£ :

BE&IN

SCWH

GETIN

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. -_ . - .

KLAWAL
IFF

DELY2

DELH

; iurm off tdke

i SCAN hEtfiOARO
ISET CHAR

it SAVE IT NHE

;ST9Af KUf MUK HERE

;PUr I JMTO A
IFUSH A
1PUT r 1N7D A

iPUSH A

iEET DELAf VALUE INTO x

UNIT K DELAr VALUE

IFQP A
i A 1MTQ f
(POP A

;a into i

iTUftW QN TONE

Listing 2. The object code produced by this program is con-
tained within the DATA lines of the pro-am in Listing 1.
Mnemonics used in this listing are a modified form of those
commonly used. (The 4T attached to some of the above
mnemonics (LDXI, for example) means "immediate." ROLA
means "rotate the contents of the accumulator left one bit/'
as opposed to RQLX, which does the same to the X register.}

73 Magazine * November, 1984 65

*5V
4

Tgnw

< I M*W

-4Mr *

|:5ikg

■-

i«

2*n

..-.^

556

- 5ttH

5JKH

*t*q

•**

1-f

Hf-

tOQ*A

-e mjd<o m

-22KH
— -w^ —

-0 TTLOUT

rf?

Fig. 2. Usable interface for converting your HF rig's audio to a
TTL signal for the VIG20. Do not omit the 22k resistor at the
output

In addition to redefining
our 22 characters, the pro-
gram will turn the audio on
and off (see lines 560, 570,
640, and 650 in the assembly
listing) This is an advantage
if your rig's audio is muted
or disappears because you
have stuck a patch cord into
the headset/external speak-
er jack.

One other desirable fea-

ture included is the ability to
vary the speed of the char-
acters moving across the
screen. All you need to do is
touch any of the keys on the
keyboard to affect the
speed The letter keys are
among the slowest while
RETURN and RUN/STOP
are the fastest The faster
the code is coming from the
rig, the faster you'll want the

display to move; otherwise,
the dots and dashes will be
very short and hard to see.
However, the slower the dis-
play speed, the more dots
and dashes that can be dis-
played on the screen at one

The Basic program (List-
ing 1) does the following:

• In line 110, a part of RAM
is reserved for the machine-
language program. Line 170
turns up the sound. Then in
line 150, twenty-two charac-
ters are printed across the
screen. These are the char-
acters which will be rede-
fined as dots and dashes.

• Next, in line 170, the char-
acter-generator table is
moved to RAM and line 190
fills the table with zeros.

• Last lines 210-230 poke
the machine-language pro-
gram into memory and then
transfer control to that pro-
gram.

Hardware Required

The program as written

may not be compatible with
Kantronics' hardware. But
changing the value of POTY
in line 190 of the assembly
listing to the input address
that Kantronics uses and (if
necessary) the logic used in
the RITECHAR routine be-
ginning at line 480 should do
the trick.

For those of us who like to

go our own way, Fig, 2 is the
circuit I'm using to convert
the rig's audio to the
+ 5/0-volt signal that the
VIC requires. Be sure to in-
clude the 22k-Ohm resistor
in series (as shown) between
this circuit and the VIC.

Kudos

I'd like to thank Skeeter
N3HB for the original idea
for the CW Banner project
His was written for a home-
brew 6800 machine. I wrote
the 6502 version for the VIC
after gaining experience
writing one for an 8085/
TMS991 8A home brew. ■

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Separate receiver, transmitter, & null controls
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ORBIT is the Official journal for the
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For a SAMPLE COPY please

send $2 to;

(AMSAT), P.O. Box 27, Washington, DC

20047.

73 Magazine * November. 1984

CALL LONG DISTANCE ON YOUR HANDHELD

The Model 335A will deliver 35 watts of
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FM and is compatible with
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TR2400, TR2500, IC-2AT,
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in will deliver 35 watts out.
Maximum input drive level
is 5 watts.

Our products are backed by prompt fac-
tory service and technical assistance. To
become familiar with our other fine pro-
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Model 335A

Kit $69.95

Wired & Tested $89:95

ifl*w|*r nrvanga

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73 Magazine * November, 1984 67

Paul Terwitttger KB2WM
54 Deny St
Merrimack NH 03054

Homemade Defroster Shutoff

This simple gadget has nothing to do with amateur radio,

but it's a neat little project anyway.

Is your car equipped with
an electric rear-window
defroster grid? Have you
ever turned it on and forgot-
ten about it until several
days later? No? then don't
bother reading any further

Being somewhat absent-
minded, this problem has
been with me for years. I
finally became motivated to
build some type of auto-
matic shut-off circuit when 1
purchased a new car. This
car had a factory-installed
defroster that was con-
trolled by an on/off switch
without a shut-off feature,
and I felt my new "toy"
deserved better than that
The original control scheme
is shown in Fig. 1 .

My old car was equipped

*HV

tQH/QfF
-^ »

ftr

with a fan that cleared the
rear window by blowing the
car interiors air at it Mar-
ginal performance and a de-
sire to mount a hi-fi speaker
in its place had resulted in
replacing the fan with a
stick-on grid defroster This
after-market unit did not
have a relay to control the
defroster power; all the cur-
rent flows directly through
the switch.

Since I had decided to
build a timer circuit it
seemed a good idea to in-
stall a similar design for this

after-market, relay-less de-
froster,

As a first step, several de-
sign goals for the timer were
developed, (1) The existing
defroster was not to be

»14V

DEFROST
GRID

PILOT

RELAY

F/g, 7, The existing defroster circuit.

H4\

fOOytF
1SV HUi.

CI
*** I3V Mill

* — •

R4
33 K

H3
ION

-Hf

u , OUTPUT

'" 555

RESET TNIGSEft

CM,

OND

fft

i 3 v = 0 N

15 v tdifc

Fig. 2. Schematic of the timer circuit.
68 73 Magazine * November, 1984

altered, other than to cut
wires. (2) There was to be no
power consumption when

the power-control switch
was off, (3) The existing pilot
light should indicate when
power was applied to the
defroster grid. (4) It should
be possible to reset or turn
off the defroster timer at
any time, (5) The circuit
should be able to cope with
power-supply variations and
noise.

Circuit Description

Fig. 2 shows the circuit
that evolved from the de-
sign goals. A 555 timer chip
was chosen as the control
element R2 and C2 are the
timing components. The
values shown produce an
on-time of approximately
four minutes. This has prov-
en to be adequate for most
situations. Increasing the
value of R2 will increase the
on-time, and vice versa, The
relationship between R2 and
the on-time is roughly linear
doubling R2 doubles the on-
time.

I have shown power-sup-
ply connections as going to
+ 14 V. These connections
are really to the positive side
of the car's battery, and the
voltage may not be exactly
14. The circuit will function
over a wide range of supply
voltages, however, so this is
not a problem.

The 555 is triggered by a
low voltage (less than one
third the supply) at pin 2. C3

and R4 ensure a low voltage
at pin 2 for a fraction of a
second after power is ap-
plied. R5 guarantees a rapid
discharge of C3 when power
is removed, allowing the cir-
cuit to be reset and restarted
quickly. R1 and CI are a sim-
ple supply filter. The output
of the 555 (pin 3) will be at
zero volts when off [or when
power is removed) and at
about one volt less than the
supply voltage when on.

There are at least three
ways to configure the
defroster drive circuit (R6,
Ql, B1, KU Figs. 3(a), 3{b),
and 4 show the choices.
With the circuit of Fig. 3(a),
the exact timer output
voltage does not make
much difference; the key is
to drive Ql into saturation.
When Q1 is saturated, its
collector-to-emitter voltage
is very small, so the voltage
applied to the relay and in-
dicator light is nearly the
supply voltage. In addition,
power dissipation in the
transistor will be minimized.

If the circuit of Fig, 3(b) is
used, Q1 will not be driven
into saturation but wilt act
like a large-signal emitter
follower. Available drive for
the relay will be about 2
volts less than the supply
voltage due to the base-
emitter drop across Ql, the
drop in R6, and the limited
maximum voltage at the 555
output Power dissipation in
Q1 will be increased be-

cause of increased collec-
tor-to-emitter voltage.

I recommend using the
circuit of Fig. 3(a) when pos-
sible, but when the connec-
tions to the relay coil are dif-
ficult to access, it may be
easier to use the configura-
tion of Fig. 3(b).

Use Without a Relay

Due to the high current in
most grid-type defrosters (10
Amperes or more), it is not
advisable to drive the de-
froster directly with this cir-
cuit. If it is desired to elimi-
nate the relay, the circuit
shown in Fig. 4 may be em-
ployed. The added transis-
tor, Q2, is to boost the cur-
rent applied to the base of
Ql to ensure that it is satu-
rated (minimum power dissi-
pation), Q1 still may dissi-
pate several Watts, so a heat
sink should be used.

Construction

Layout and construction
style are not critical. I chose
to use a small piece of
punched phenolic board for
the timer and point-to-point
wiring.

R2 and C2 are the only
components with somewhat
critical values. Most other
components can be of what-
ever values exist in your
junk box. Every one of the

timers I have constructed
used different component
values! just make sure Ql
will saturate and that the po-
tential on pin 2 of the 555
will rise above 5 volts after
C3 charges.

Installation

Finding a convenient lo-
cation for the timer may be
the most difficult part of the
project, especially if a facto-
ry-instalfed defroster and
switch are to be modified.
There is usually very little
extra space behind the dash-
board, and Murphy's Law
says that if there is extra
space it will be located so as
to be least useful.

If a relay is not used, an
acceptable solution might
be to mount the timer right
at the defroster grid's ter-
minals or just on the other
side of whatever hole the
wires go through. Since the
circuit can be made reason-
ably small, it might not be
objectionable if left in the
open.

After-market add-on de-
frosters should make for an
easier job. There is probably
enough room near the
switch to install the circuit

Many defroster switches
have an indicator light in-
corporated into the same

D£FR05T
GRID

■.'I

OUTPUT

R6
IK

Fig. 4. Output circuit for a relay-iess system.

@ATTERY
+ t4V

SWITCH ASSEMBLE

, TT ■

WYVVV\.

14V

TIMER CIRCUIT
(FIGURE Zi

OUTPUT

■LiNTl

Fig. 5. Taking advantage of a combined switch/light
assembly.

t* See List of Advertisers on page 88

+ I4V

Fig, 3(a). Preferred output circuit.

package, A suggested meth-
od for using this type of
switch/light combination is
shown in Fig. 5.

As with any electronics,
care should be taken to in-
stall the circuit so that it will
not accidentally contact
metal and short out. I chose
to let the circuit be sup-
ported by its connecting
wires and insulated it by
wrapping it in several layers
of electrical tape.

Final Comments

All three timer circuits
have been tested in my cars.
Although the timer chip I
used (an NE555) is rated for
the "commercial" tempera-
ture range — zero to 70 de-

Ul OUTPUT

R<5
IK

■\Af*--

NPN
POWER

Fig, 3(b). Alternative output
circuit for use when relay is
hard to access.

grees centigrade— the circuit
still worked well when
temperatures dropped to
about minus 1 5° C. A military
temperature range ( — 55° to
+125° C) version, an SE555
for example, would increase
low-temperature reliability,
but I have not been able to
locate a source for this ver-
sion.!

73 Magazine * November, 1984, 69

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MOBILE IGNITION SHIELDING. Free litera-
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WANTED: Cash paid for used SPEED RA-
DAR EQUIPMENT Write or call: Brian ft
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REPAIR, alignment, calibration. Collins
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IMRA— International Miss ton Radio Asso-
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ELECTRON TUBES: Receiving, transmit-
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SCIENCE SOFTWARE for VlC-20 and
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SWL REPORT FORMS designed for maxi-
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Give real meaning to your DX reports. De-
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ANTENNAS WANTED: We pay cash for
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NEW HAM SWL SOCIETY for unity of
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SASE tor info to HCSW, 32 Applegate.
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KTSS SUPER DX SLOPER 80-1 Om only
$59.95. KT5B multiband dipole 160- 10m
only $59.95. 2-kW roller Inductor (28 uH)

HM HELP

I am seeking technical assistance in
modi tying the TXiHX switching speed of a
Yaesu FM01ZD for use on AMTOR.

Daniel Muiray WA7Y1C

1541 O*bow Circle RR #11

Billings MT 59101

I need car license plates with ham calls

lor my collection. I collect used plates
from any state. I will gladly pay lor the
mailings — surface please. Addresses
where I can get plates would also help.

Wilhelm Johannes YD2DKL

Pandega Puts MM 7

Yogyakarta. Indonesia

(274) 2341

S47.50. Weather-ooot kit (PL-259) SS.95
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COMMODORE 64 OWNERS: Now a custom
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CX7 REPAIRS. Mark Mandelkern. 2315
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SCHEMATICS: Radio receivers i920s^0s.
Send name, brand, model no, SASE Scare-
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MAKE PAINTED CIRCUIT BOARDS with-
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DX HEADING MAPS for Boston, NYC, Phila.,
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WANTED: pre-1950 bugs and pre-1925
wireless keys lor my collection Neal
McEwen K5RW. 1128 Midway. Richardson
TX 75081. BNB222

KENWOOD T5-430S OWNERS! Scan all
modes like a Bearcat with the STOP-
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Box 366, Alexandria IN 46001. BNB223

KEYEfl/CODE-TRAINER CHIP, Qne-eve-
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per that contains over 200 big 11 x 14 pages
of ads from Individuals and mail-order
Stores, Ads contain computer equipment
and software at lowest prices in nation.
Subscription Si 5 per year. Computer
Shopper, PO Box F340, Titusville FL, (305)-
269-3211 SNB225

WANT OLD ANTENNA BOOKS, Hand-

books. CQ, pre-1940 OST, KT7H, 5519 12th
NE, Seattle WA 98105. BNB226

TS1 000/1 5007ZX81 2K Morse-code transla-
tor— no hardware interface required'
Code received through ear jack is scrolled
across screen. The code can come from
any source of adequate volume and clari-
ty. Second part of program translates
character string Into Morse code in tone-
burst form. Code speed is user-selectable
from 9 to 100 wpm. See review in June,
1964, issue of 73 on page 92, $9.95 plus
$1.00 s&h. Thomson Software, PO Box
1266, Lombard IL 60148. BNB227

YOUR IC-720 can become a sophisticated
com puter-conl rolled scanner. Keyboard
frequency entry, 64 memories, memory
scan, mode scan, station lists, more. No
interface required, jusi a cable— direc-
tions included. Software cassette for
Commooore 64, $14,75 pp David Oliver
W90DK. RR 2 Box 75A, Shevlin MM 56676,
BNB228

DIGITAL AUTOMATIC DISPLAYS for FT
101s. TS-520s (direct functional replace-
ment for the DG-5), Collins, Drake. Swan,
Heath, and others. Six 1/2" digits. Write for
information. Grand Systems Dept. A, PO
Box 3377, Blaine WA 98230; (604^5304551,
BNB229

NEED MANUALS FOR: Johnson Viking llh
vto. and Mai ch box, Kenwood HCMO world
clock, CD£ H-1V/CD45 rotor control. I COM
IC-RM2 computerized controller; Steve
Sanow, 3101 Washington #93, Bellevue
NE 68005: (402>291h4»42. BNB230

HIGmJUALiTY, LOW-COST courtesy beep-
ers for your transmitter or repeater. Kit
Si 4. assembled SI 8. Y&M Enterprises, 8502
N. Oketo Am. Niles IL 60643. BNB231

YOU HAVE THE ABILITY . . - you can quie*
ly learn security alarm business. We make
it easy. Wonderful employmenUbusiness
opportunities. Insider's inlormation $2.00
postpaid. Security Electron kes interna
tlonaL PO Box 1456-K R, Grand Rapids Ml
49501. BNB232

GREAT CIRCLE BEARINGS— stop guess
Ing. Send us your QTH or your latitude and
longitude and get a personal accurate
computer printout of headings and mile-
age from your own QTH to over 500 cities
and countries throughout the US and the
world, S3.ft5, APCA Systems. PO Box 978,
A/buckle CA 95912. BNB233

SIGNAL GENERATORS, excellent lab-
tested HP606A, 50 Hz to 65 MH2 5375,00:
HP-6QBC. 10 MH2 to 480 MHz $345.00:
HP614A, 900 MHz to 2100 MHz $345.00;
HP618BT 3.80 Hz to 7.6 GHz $375.00;
URM-2S, 10 kHz to 50 MHz S245,00; URM-
26, 4 MHz to 400 MHz $245,00; T&497/URR,
2 MHz to 400 MHz $185,00; Jerroid 900C
sweep generator, 500 kHz to 1200 MHz
$345,00; military SG-3>URM-70 FM signal
generator, 50 MHz to 400 MHz $285.00;
HP87QBA synchronizer S325.00; TS-148^
UPM-33 radar spectrum analyzer, S470
MHz to 9630 MHz $185.00 We accept M/C.
Visa, or check; add shipping. Phone Bill
Sleo (704)-524^7519; or write Slap Electron-
ics Company. Highway 44 1, Otto NC 28763
BNB234

SUPER SAVINGS Bearcat and Regency
scanners, shortwave receivers and acces-
sories, ham gear ICOM. Kenwood, Yaesu.
Ten-Tec, Gushcraft. MPJ. Antennas,
Coax, motet'. Free UPS shipping and In-
surance to 48 states. 25-page picture cata-
log S 1.00 (refundable). Galaxy Electronics,
Box 1202. Akron OH 44309; (21 GK37&-24D2
9-5 EST. BNB235

70 73 Magazine * November, 1984

RTTY LOOP

Marc L Leavey, M.D. WA3AJR
0 Jenny Lane

Pikesville MD 21208

Chalfo up another victory for the pirates.
Calm down Pittsburgh, not the ones that
played our Orioles a few years back, I am
talking about the software variety,

F have been gently nudging my acquain-
tance oliI wesl. Clay Abrams, to try to
adapt some ot his CoCo# RTTY software
to the newer versions of the TRS-80C Col-
or Computet* and to add disk capabili-
ties. Well. Clay has written me that, tor a
variety of reasons, such a version will not
be forthcoming. One of the major reasons
thai Cfay has come to this decision is thai
there appears to be a huge number of
bootlegged copies ot his tape-based pro-
grams tn circulation. Huge, that tst when
compared to the number he has sold. So
Clay has come to the conclusion thai it is
not worth Investing large amounts of time
and sweat into a program only to have II
circulated '"Ireeoie-style1" between bud
dies. Flattery Is nice, but It don't pay the
bills.

So look for more of C fay's work not In a
catalog, but in the pages of this and other
magazines. By publishing what he writes,
he can realize a return on his effort and
make the informal ion available to inter
ested individuals.

As for my efforts along the same lines,
I am continuing to dabble and will either
publish a set of routines here (in serial
fashion) o* try to organize them into an ar-
ticle for independent publication. Stay
tuned,

Along these lines, regards to Frank
Fields KflQQJ who is using a CoCo under
Clay's original program. Keep up the
spirits, Frank With the capabilities inher-
ent in the CoCo, I am sure that a program
will appear on the scene which will run
rings around those available for other
small computers.

Along the line of useful tidbits comes a
letter from Ocean City, Maryland, In this
vacation haven of Maryland lives Jim Con-
ner W3HCE, an old-time RTTY buff from
the 'old school." as he puts ft Jim is an
active amateur on the Maryland eastern
shore, using a iocal two-meter repeater tor
VHF RTTY operation. He picked up I he
new Heathklt HO-3030 RTTY terminal In-
I erf ace. This $250 box is a combined ter-
minal unit and AFSK generator, sort of a
RTTY modem, which appears to have
great capabilities (according to the cat a
log blurb). Maybe I can convince Benton
Harbor to spring tor some more informa-
tion on it in the future.

Anyway, Jim (nought that the utility of
the HQ-3030 would be enhanced if an in-
terface between it and his piles of ham
gear coufd be designed. His intent was to
be able to operate either on Morse or
RTTY on both the HF and VHF bands, al-
lowing for monitoring ol the signals and
control of the transmitter push-io talk
(PIT) fine; features which the HD 303G
lacks.

Attacking the PTT problem head on, Jim
found that while the voice-operated trans-
mit switch (VOX) on most HF transmitters
allowed operation unmodified with that
mode, there was no convenient way to key
the PTT line on the VHF transmitter Dig-
ging into the HD-3030 revealed that the
send-receive push-button is a double-pole
switch, with only one pole being used.
Running a wire from the unused side ol
the switch to pin 23 on the DB-25 connec
tor. an unused pin, and to ground on the
other side ot the switch provided a conve-
nient added PTT switch, appropriately
labeled, with minimal modification to the
HMD30 itself.

He then used a tour-position, seven-
pole rotary switch to select which of tour
modes— VHF MCW, VHF RTTY, HF CW.
or HF RTTY— Is to be operated, The
switch used Is a Centralab PA-1027, an

PARTS LIST

Cabinet

Switch, rotary. Centralab PA-1027 (8 Pole. 5 Position)

Cabinet

270-269

4-pin mike sockets

274402

4-pin mike plugs

274-001

Phono sockets

274-346

Phono plugs

274339

3" PM speaker

40-246

LEDs w/holder

276-0B0

25-pin socket (D-25)

276-1548

25-pin plug (D-25)

276-1547

Hood for 0-25 plug

276-1549

SPOT center-off toggle switch

275-325

330-Ohm, 1/4 Watt resistor

271-1315

Knob w/lndlcator (for switch)

274^*14

Knob (for volume control)

274-415

Ac fine cord

278-1255

Fuse holder

276-369

Fuse. 1 Amp

270-1273

Power Supply

Power transformer, 6.3 V. 300 mA

273-1384

Rectifier diodes. 1N4001

276-1101

Capacitor. 1000 *tF, 35 V

2721019

Capacitor. 10 mF, 35 V

272-10 f 3

Voltage regulator. 7805,, 5 V

276-1770

330-Ohm, 1/4-Watt resistor

271-1315

Amplifier

Op amp, LM366 IC

276^731

8 -pm IC socket

276-1995

220 jiF, 16~V capacitor

272 1029

0.05-hF disc capacitor

272-134

0.1 ^F disc capacitor

272-135

0.01 jiF disc capacitor

272-131

10-Ohm, i «4 Watt resistor

271-1301

lOk-Qhm volume control

271-1721

Af Oscillator

2K2222 transistors

276-2009

2 N 3904 transistor

276-2016

9lk-Qfim. V4 Walt resistors

Jameco

4.7k-Ohm, 1/4 Watt resistor

271-1330

tflOk-Ohm. 1/4-Watt resisior

Jameco

3.3k-Ohmt 1/4 Wall resistor

271-1328

Ik-Ohm, V4-Wail resistor

271-1321

lOk-Ohm, 1M Watt resistor

271-1335

5k-Ohm, POtype potentiometer

271-217

10k-Ohmb PC-type potentiometer
0.0047 fjF mylar™ capacitors

271-216

Jameco MY.0047/100

eight-pole^ five-position switch which Is some of the larger parts Jobbers In your
only partially used. You may have to try area to find this switch. To help shield the

trs- eoc

i - cm©

• -nut PAT*

LEDS

VHF MCW

vnr Fm y

1t /jjfc »f "I"

U J

*>LTS

[330H

Ht NC NC

J. 1»

MCW

GN0

3
DEM OO
1TTL!

prr

Ptf

-* PiN NUMBERS I/O CONNECTOR
HD-3fJ*Q

HF 1CMTI* Z -*T

i - mc

VHF MMTti I -PTT

i • - GN0

5 IE
£>SEN0

fN rec

IS
AFSH OUT

13
AF INPUT

Fig. 7. H 0-3030 wiring modifications.

©«F

jr "" AF SIG tN

sic

MOD

©VHF

£r -<H

oj 5P

73 Magazine • November, 1984 71

SlG IN

if GAIN

.01

22CVF
>6V

/ff

•ft

-Hf-

T«

$P£A«E4

lOfl

A.F »MP

fig 2 This cucwt adds an audio output to the HD-3030

IN400K4)

T30S

*5VDC

RWT3-<a*4

1 15 VAC

l 2 3

^LiOOOfF

LLo^

7: I,.

*3V POWER SU^Pf

f\% 4, An easily constructed 5-vott power suppJjr

+sv

PIN *

•Tfis-eoc

tHMU sie

TWIN "T" A F OSC

Fig. 3, A twin-T audio oscillator used to generate MCW.

cabling from floating rf. the wires between
the HD-3030 and the Interface box were all
enclosed in a braided shield removed
from an old coaxial cable Fig, 1 shows the
wiring ot the mam interface unit.

Several auxiliary boards were also con-
structed to add a few features here and
there. Fig. 2 shows * small audio ampli-
fier, based on the LM386 op amp. which is
used to drive a small speaker with either
the transmit or receive audio. Although
the HD-3030 is able so receive modulated
CW tMGvVj, it cannot generate this type of

signal. Therefore, Jim used a classic cir-
cuit, the twJn-T audio oscillator, to gener-
ate the audio waveform which the com-
puter can turn on and off in order to trans-
mit MCW. This circuit is shown In Fig. 3.

A rather conventional live-volt power
supply runs the whole thing, arvo Jim's
version is shown in Fig. 4. Except for the
Cenlralab switch, aft of the parts used in
the interface are available from a variety
Of sources. The parts list gives a Radio
Shack part number for all parts available
there Those few that are not carried at the

Free Antenna Accessaries Catalog

i Coaxial Antenna Relays

Remotely select up to 9 antennas
from your transmitter, using only one
coaxial cable Environment a! ized. high
power and low loss

W2AU and W2DU Balunst

Our baluns, center insulators and in-
sulators have been preferred for 20
years by Hams, industry, and the armed
forces Protect against TV1 and lighining
1 8-200 MH*

4 W2 VS Antenna Traps

Add these traps to your dipole and
get low SWR on 2 to 6 bands, depen-
ding on how many you add Antenna
wire and custom kits also available

Send For Yours Today*

Don t delay Call or write today, and
we will send you free literature which
fully describes our Ham antenna ac-
cessory product line

Dealer inquiries also welcome.

i^166

^li.iWJiWJ.^VWJIi'itN

A Eliviiiinn uf Mw'iWiiH' Filter Co luc

G743 Kinne St.. East Syracuse. NY 13057

Toll Free t -80 CM14 6-1666 TWX 7 f 0*54 1-04 9 3

tVYJHNAKfConada (Collect) 315 437-3953

Shack can be found in the Jameeo catalog
or on the wall of an Independent electron-
ics store. It would appear that even II you
live in the middle of nowhere, you should
be able to obtain I he parts by mail order.

Jim drives the HD-3030 and his RTTY
station with a program running on a TfiS^
6QC He did not specify which program he
uses, bul I would not doubt if il <s Clay
Aorams NEWRTTY that we talked about
earlier. Welt, Jim. this looks like a very fine
piece of work, and I am sure that the
crowd appreciates your sharing it with us.

For those of you who have been looking
for RTTY mailboxes, the coming months'
"RTTY Loops'1 will be just the ticket 1

have received quite a few listings and will
put them all together for your enjoyment. I
will also have the usual December shop-
ping spree, a feature I know you enjoy by
your comments. Also, the first four issues
of RTTY Loop'4 extracts remain avail
able. Send $2.00 for each issue desired
with a self-addressed, stamped envelope
for each issue to the above address. It you
would like a hsting of what's available,
jusf send the SASE. I especially appre-
ciate all the nice comments I have been
receiving lately, particularly those which
say that when the new 73 arrives, the first
place you turn is back, here, to "RTTY
Loop!"

SATELLITES

USING THE AO 10 APOGEE PREDICTIONS

Apogee predictions for the month of November are provided lor three sections of the linn
ed Stales Washington DC at 39N 77W, Kansas at 39N 95W. and California at 38N 122VV
Times are m UTC and apogee in this case is mean anomaly 128 rounded to the nearest
whole hour. Use the chart as a guide in aiming your antenna, then f rne-iune the azimuth and
elevation values to peak the satellite's beacon stgnai ff you require more accurate orbital
predictions, contact AMSAT at PO Box 27, Washington DC 30044

WASH

KANSAS

CAL1

ORBIT

DAY

TIME

======

WS-=-=

: — ==::=:=— =

: = = = = = -

r ====^

= — — = =j

___, s

_ — ^ — ,,

3H1

L374

2200

140

1 15

1376

2100

122

104

1378

2100

118

102

1380

2000

107

1381

0800

280

1382

1900

2LJ

1383

0700

2 74

1384

1900

1385

0600

264

269

1386

1800

1387

0600

279

263

1388

1700

1389

0500

284

273

256

1390

1700

1391

0400

278

267

247

1393

0400

273

26 1

238

1395

0300

267

253

223

1397

0200

260

244

202

1399

0200

253

235

188

1401

0100

244

220

161

1403

0000

231

198

137

uos

0000

221

185

Ml!

132

1407

2300

201

160

117

1409

2200

175

138

105

3fj

141 1

2200

164

132

104

1413

2100

141

117

1415

2000

124

106

2000

121

104

1419

1900

109

1420

0600

277

1421

1800

1422

0600

27 2

1423

1700

1424

0500

281

265

1425

1700

1426

257

258

1427

1600

1428

0400

-70

252

1430

0300

275

264

242

1432

0200

269

256

229

72 73 Magazine • November, 1984

SPECIAL

Listings in this cofumn are provided freed
charge on a space-avatfabfe basts. The foh
f owing information should be included in
every announcement sponsor, event date,
time, place, city, state, admisston charge Of
any), features, lafk-m frequencies, and the
name of whom to contact tor further mfornia*
tkm. Announcements must be received £>y 73
Magazine by me first of the month, two
months pnor to the month m which the event
takes piactt Maif to Edftonaf Otftces, 73 Mag-
azine; Pine St.. Peterborough rVH 03458

ALBUQUERQUE MM
MOV 3

tie UNM ARC and the Weslside ARC
will jointly sponsor a tailgate swapfes? on
November 3. 19B4, from 10:00 am to 2:00
pm MST, on the UN M North Campus part-
ing tof. corner of University Boulevard and
Tucker Avenue, Albuquerque NM. Admis-
sion is free: bring your own tables as none
will be furnished Talk in on 1 47.75/ U7 15
MHz and 4493/444.3 repealers. For tun her
information, send an SASE 10 Gary Bone-
brake KQBI. 974 Arkansas SE, Rio Ranch©
MM 87124, Robert Scupp WB5YYX, 64a
Marquis Drive NE. Albuquerque MM
87123. or Jay Milter WA5WHN. 4613 Jupi-
ter NW, Albuquerque NM 87107, or via
3.939 MHz. 0100 UTC dairy

SOUTH GREEMSBURG PA
NOV 3

The Foolhills ARC will hold its Six-

teenth annual hamfest on Saturday, No-
vember 3, 1984, at St. Bruno's Church,
South Greensburg PA_ Tickels are $2.00
each or 3 for $5.00; indoor (lea-market
tables are $5.00. Refreshments and food
will be available. TaIMn on 147,78/. 18. For
further information, advance tickets, or
tables, contact Ronald NavigJia WA3HOL
or write FARC. PO Box 236, Greensburg
PA 15601.

$€UEJ*5VILLE PA
NOV 4

The R F. Hill Amateur Radio Club will
hofd .15 ann.^at InrJoor Wirrer'esi 0fl Sun-
day. November 4, 19B4, beginning at 8.^00
am, a I the Seilersville National Guard Ar-
mory {located appro* imatefy 5 miles from
the Pennrtdge Airport, halfway between
Philadelphia and Allen town, near the
lunction of PA Routes 309 and 563h Sei-
lersville PA. Entry is S2-00 and non-ham
spouse and children are admitted free
when accompanied by a paying ham. In-
door spaces (&' x 6") are S6,00 each and
outdoor spaces (1 pa rking-s pace- width
frontage) are $4.00 each. The purchaser ol
vendor space will receive a single admis-
sion and must supply his own table. Food
will be available qn the premises and res-
taurants are nearby. Talk-in on 145.19(f)).
14888(RK and 14652 (simplex). For ven-
dor space reservations, write PO Box 29,
Colmar PA 18915. or phone j21 5) 721-0278
(Call will be returned collect during the

evening). Because there is no discount for
advance purchase of entry, buyers are en-
cou raged to purchase admission at the
gate

GRAVSLAKE IL
NOV 4

The Waukegan Civil Air Patrol will hold
Its 4th annual hamfest on Sunday. Nqvem
Per 4, 1984, from 0700 to 1700, at Lake
County Fairgrounds. Rtes. 45 and 120.
Gray slake JL Admission is $3,00 and
tables are $500, For further In format ion
and reservations, send an SASE to CAP,
637 Emerald, Mundeiem JL 60060

TAYLOR Ml
NOV 4

The RADAR eighth annual Swap and
Shop will be held on November 4, 1984,
from 8:00 am to 3:00 pm, at Kennedy High
School in Taylor ML ActiwHes and forums
are scheduled and free parking will be
available. For more information, send an
SASE to RADAR, Inc.. PO Box 386r Taylor
Ml 48*60. or call (3 13>29I 2288.

MONTY* ALE NJ
NOV 10

The Stateiine Radio Club ol New York
and New Jersey will hold Radio Expo 84
on Saturday, November 10. 1984, begin-
ning at 8 00 am, rain or shine, at Pascack
Mills High School. Grand Avenue and
Spring Valley Road, Monlvale NJ. Take
New York State Thruway south to the
School ho use Road e*ii, then south on
School ho use/Spring Valley Road: or take
Garden Stale Parkway north to Exit 172,
then east on Grand Avenue. Donations are
$3,00 each (available only at gale). Tables
are S10.00 by mail prior to October 3ist

and $13.00 at the gate; tallgaters' fees are
$5.00 by mail prior to October 31st and
$7.00 at the gate. Doors open for vendor
setups at 6:00 am. Features will include
FCC license exams through Extra class.
DX films and forums, multimedia prr>
grams, a transceiver clinic (HTs checked
free of charge}, a food concession, and
ample parking. Tallin on 148.835 repeater
and 146.565 simplex. For further informa-
tion, contact Robert GreenquisL PO Box
325, Montvafe NJ, or phone {201^-686-3902,
day or evening.

WEST CONCORD MA
NOV 10

The 35th annual New England DXCC
Dinner wit! be held on November 10, 1964,
at the Concord Lodge of Elks, Baker Ave-
nue, West Concord MA {near Routes 2 and
62). Activities will begin at 2:00 pm with a
variety of DX talks and slide programs in
eluding video tapes of VU7WCY and
XUiSS. The charge for the afternoon ses-
sion is $2.00. The cocktail hour will be at
6:00 prn and at 7:30 pm. a seven-course
family-style roast beef dinner wilt be
Served. The banquet speaker writ be Fred
Laun K3ZO (ex-HSlABD). The charge for
the evening is SI £.95. For more Informa-
tion, contact Steve Tolf K1ST, 12 Phylmor
Drive, Westboro MA 01581.

WEST MONROE LA
NOV 10

The Twin City Hams will sponsor an all-
indoor hamfest on Saturday, November 10.
1984( from 9:00 am to 3:00 pm, at the Con-
vention Center. Nr 7th Street, West Mon-
roe |_A. Features will include exams, swap
tables, new-equipment dealers, and a
ladies' program. Talk-in on 1 46-25/. B5, For

ATTENTION
SUBSCRIBERS

We occasionally make our mailing list
available to other companies or organiza-
tions with products or services which we
feel might be of interest to you. If you prefer
that your name be deleted from such a list,
please fill out the coupon below or affix a
copy of your mailing label and mail it to:

C-W. Communications/Peterborough
73: Amateur Radio's Technical Journal

PO Box 931
Farmingclale, NY 11737

P/ease delete my name from mailing lists sent

| to other companies or organizations.
I

| address
\city

name

1
I
I
I
I
I

state

zip

NEW PRODUCT DENTRQN QRV-1

SPECIFICATIONS QRV-1
All Solid state construction
Four-place digital display
No tune-up
Full break-in CW

Internal adjust CW sidetone volume
'S' meter for receive and transmit
5 watts power output CW
Battery operation possible due to low current
consumption

Transmitter spurious emissions all down 40 DB
Direct conversion receiver
CW narrow and wide positions for receive
Receiver sensitivity: 0,5 uV 10dbsn/N
IDEAL AS A BEGINNERS RIG/WONT BUST YOUR
POCKET BOOK!

DENT RON

287

Div. of Coilco Electronics, Inc.
223 North Michigan Avenue - P O. Box #848

Edgerlon, Ohio 43517
419-298-2346

Out Of State Call Toll FREE I 80a 9Z2&SS 8

* See List of Advertisers on pay* 86

73 Magazine • November, 1984 73

more inform at too. contact Benson Scott
AE5V, 107 Comempo, West Monroe LA
71291

NEWMARKET DMT CAN
NOV 10

The York Region ARC will present the
Sth annual Newmarket Flea. Market an
Saturday, November 10, 1984, beginning
at 0800, at the Newmarket Community
Center, Civic Drive, Newmarket (just north
of Toronto). Admission is S2.00 per person
and children under 12 will be admitted
free. Table rentals are S3.00 each plus
general admission and wilt be held only
until 0800 unless payment is made in ad-
vance {setup is at 06001 Refreshments
will be available For table reservations
(include a check or money order made out
to the York Region ARC} or more informa-
tion, contact Geoffrey Smith VE3KCE- 7
Johnson Road, Aurora, Ont., Canada L4G
2 A3, or phone {4 16>7 27-6872 (evenings).

STONE MOUNTAIN GA
NOV 10-11

The Alford Memorial Radio Club wilt
host the 12th annual Stone Mountain
Famvention on November 10-11, 1&&4. at
Stone Mountain Park, Stone Mountain
GA_ Hours On Saturday are 9:00 am to 5:00
pm and on Sunday, 9:00 am to 3:00 pm, Ad-
mission is $4.00. which includes admis-
sion for both days, parking a It ha hamtest
site, and the Saturday-night cookout. Ac-
tivities win take place at Lakeside Center,
with Inside dealer displays and light re-
freshments in the Hospitality Room, The
Scneyard Mile will be just outside and a
full hookup campground is adjacent
Plans are at l his time to give e*arns Nov-
ice through Extra class, at the Stone
Mountain Inn on Saturday and Sunday be-
ginning at 8:30 am Taik-m on 1*6 16J 76
For more information, write Jim Gamer
KE4BI, 490 Village Green Court, Lilburn
GA 30247, oi phone (404J-921 7588

VETERANS DAY SPECIAL EVENT
NOV 10-11

The Armored Force Amateur Radio Na-
tionwide Emergency Team (A FAR NET)
will sponsor a Veterans Day activity for
the amateur community on the weekend
of November 10 and 1 1, 1984. Member sta-
tions will participate as special-event sta-

tions for the net A special commemora-
tive certificate will be available to all ama-
teur stations that make contact with one
member station. Met stations will operate
on the Veterans Day weekend from 1200
GMT an Saturday, November 10. 1984.
through 2400 GMT on Sunday, November
11. 1984, Primary frequencies will be as
follows: 7285 kHz, 14,325 kHz, 21,375 kHz,
and 28,640 kHz (plus or minus ORMJ. To
obtain the certificate, send a OSL and a
large SASE to the net's manager, Alfred G.
Beuiler, 36 Manchester Rd . East Aurora
NY 14052-

NORTH HAVEN CT
NOV 11

&■

The Soufhcentrai Connecticut Amateur
Radio Association (SCARAt will hold its
5th annual Electronics Show and Flea
Market on Sunday. November 11. 19B4,
from 9:00 am to 3:00 pm, at the North
Haven Recreation Center, L ins ley Street,
North Haven CT. Admission Is Si. 50 and
children under 12 accompanied by an
adult will be admitted free Tables are
Si 000 in advance for the main hall and
$12.00 at the door. {Reservations are
strongly advised. I Setup will be at 8:00 am,
and for new-equipment vendors, a special
exhibit area with setup security arrange-
ments will be made available, There will
be food both at the food booth and from a
mobile cart Features will include the
latest in ham radio, computers, and elec-
tronics, Talk-In on 146.01/146.61 (W1GB).
For more information, directions, and res-
ervations (make checks payable to
SCARA), send an SASE lo Tony Vanacore
AK1CL PO Sox 81, North Haven CT 06473,
or phone (203H84-4175 (home) or (2031-
239-5321, extension 311 (days).

FORT WAYNE IN
NOV 11

The Allen County Amateur Radio Soci-
ety. Inc., will sponsor the 12th Fort Wayne
Ham test on Sunday, November n, 1954,
from B:Q0 am to 4:00 pm, at the Allen
County memorial Coliseum, Coliseum
Boulevard (US 30) at Pa me 1 1 Avenue.
Tickets are $3.00 in advance and £3,50 at
the door. Tables are $800 and premium
tables are 120,00. Vendor setup is from
5:00 am io 700 am. No tables will be sold
at the door, and the ticket- and table-reser-
vation deadline is October 20th Activities

will include a targe Indoor flea market,
commercial vendors, the Ham Band under
the direction of Luke Matthew WB9EWJ,
and all classes of radio exams isend Form
610 and an SASE to VE Coordinator,
FWRC, PO Box 15127. Fort Wayne IN
46885. by October 281 h}. TaJMn on .88. For
tickets, tables, or more information, con-
tact Mamfest Chairman AC*AHT5T PO Sox
10342, Fort Wayne IN 46851, or call Dave
Smith KA9FFT at (219) 493 2439.

MASSILLON OH
NOV 11

The Mass t Hon ARC will sponsor Auc-
tionfest 84 on November II, 19S4. at the
Massillon K of C Hall, off Route 21. Mas-
Si lion Ohio, from ffcOQ am to 5:00 pm. Sell-
ers' setup is at 7 00 am. Admission is
$2 50 in advance and $3.50 at the door
Tables are available at £7.00 per 8- foot
Space. Refreshments are available and
there will be a sit-down dinner. There will
be plenty of free parking. The auction
starts at 11:00 am. Talk In on W8NP,
147.78M 8. For advance registration or In-
formation, send an SASE to MARC. 920
Tremont Avenue SW, Massillon OH 44848

PENANG, MALAYSIA
NOV 16-18

The Malaysian Amateur Radio Trans-
milters Society (MARTS) will host the 14|h
SEA NET Convention on Friday, Saturday,
and Sunday. November 16-18, 1984, at the
Eastern and Oriental Hotel, Penang, Ma-
laysia, Features will Include symposiums,
luncheons, tours, and rag-chewing Tor
more details, contact Malcolm West-
wood, Organizing Secretary. SEA NET. PO
Box 13, Penang, West Malaysia,

BILLERICA MA

NOV 17

The Honeywell 1200 Radio Club and the
Waitham Amateur Radio Association will
hold their annual amateur-radio and elec-
tronics auction on Saturday, November
17. 1954, beginning at 10:00 am, at the
Honeywell Plant, 300 Concord Road, Bll-
lerlca MA (Exit 27 off Route 3), There will
be a snack bar; a bargain parts store, and
free admission and parking. Talk-in on
147,72/12 and 146 04/64 (club-sponsored
repeaters}. For more information, contact
Doug Purdy N1BUB. 3 Visco Road. Bur-
lington MA 01603.

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RADIO SALES

400 LAKEDALE ROAD, DEPT. C
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(91?) 993-5881 Noon to IQ P.M. EST

PLYMOUTH MA
NOV 22

A special -eveni station fWAi NPQ> from
Plymouth. Massachusetts (America's
Hometown) will be sponsored by (he Whit-
man Amateur Radio Club and PI I moth
PI an ration on Thanksgiving Day, Novem-
ber 22. 1964. An attractive certificate suit-
able for framing wilt be issued to any for-
eign or domestic amateur who makes con-
tact with this slat Ion. which will operate
from 9:00 am unlii 3 00 pm. The station will
be In operation at the Plimoih Plantation
from an indoor site in the museum's 1627
Pilgrim Village.

Frequencies are as follows: 1300 to
1430 GMT-21.260 MHz: 1430 to 1730
GMT— 7^fl0 MHz i GftN andior 7.050
MHz ICWK 1730 to 2000 GMT —21.385
MHz; 1300 to IfiOO GMT— 14.255 MH2 or
14 180 MHz. 1400 to 1500 GMT— 14.025 ±
QRM; 1600 to 2000 GMT— 14.345 MH2
Thefe will be limited 2-meter operation on
the local club repeater (tentative):
147.225/.335 and 145.52 simplex

A UK club stallon Is planning lo partici-
pate: GB2UST (United States Thanksfliv
\nr$ on 20m arid 15m and GB4UST on BOm
and 40m. ihey have some forty acres in
which to erect antennas.

To recetve a certificate, send proof ot
contact and S1 .00 or four iRCs to the Whit-
man AHC. PO Boa 48, Whitman MA 02382

GREENSBORO NC
NOV 24-25

The 4th annual Greater Greensboro Mani-
fest will be held on November 24-25. 1984,
from 9:00 am to 5:00 pm, a\ the Nallonai
Guard Armorv, "1100 FFanKlin Boulevard.
Greensboro NC. For advance llckets, send
an SASE to Fred Redmon N4GG0, 2305
Sherwood Street. Greensboro NC 27403
For dealers1 space, tallies, and flea market
information, contact Coy Hennts WD4NHL
al e 191-294^2841

OAK PARK Ml
NOV 25

The Oah Park High School Electronics
Club will hold its loth annual Swap N"
Shop on Thanksgiving Sunday, November
25, 1984, from 8:00 am lo 4tf0 pm, at the
Oak Park HJgh School, Oak Park Ml. The
doors will open at 6:00 am. Admission is
S200 and 8-foot tables are $6.00. Refresh-
ments will be available. For more informa-
tion, send an SASE to Herman Gardner
Oak Park High School. 13701 Oak Park
Boulevard, Oak Perk Ml 48237. or phone
(313^968-2675

STONY BROOK NY
NOV 25

The Radio Central ARC will present the
6ih annual ARRL Ham-Cenlral on Sunday,
November 25, 1984. from 9:00 am to 3:00
pm, la the social hail of Temple tsaiah.
1404 Stony; Brook Road, Stony Brook.
Long Island NY. General admission is
S3 00 and children under 12 and Kits will
be admitted free. An 8-foot labia space
S7.00 and includes one free admission,
Doors will open at 7:30 am for dealers and
sellers | ham related items only). There will
be food, drinks, and free parking avail-
able, Seminars will feature speakers
Gerry Hull VE1HMAAM on the St. Paul
Island DXpedlMon of 1983, Paul Beeman
KA2MUM with an OSCAR lecture and
slide show, and Art Green berg W2LH and
Madeline Greenberg W2EEO with an an-
tenna lecture Talk- In on 144.550H 45.150
and 146 52. For reservations and more in-
formation, contact Sob Yarmus K2RGZL 3
Haven Court, Lake Grove NY 11755, or
phone i5i 6|-98 1-270Q Monday through Fri-
day after 6.1X) pm

74 73 Magazine * November, 1984

CIRCUITS

Do you have a technique, modification, or easy-to-dupficate cir-
cuit that your fellow readers might be interested in? If so, send us a
concise description of it (under two pages, double-spaced) and in-
clude a clear diagram or schematic if needed.

In exchange for these technical gemst 73 offers you a one-year
subscription (or extension), to be sent upon publication. Submit your
idea to: Circuits, Editorial Offices, 73 Magazine, Peterborough NH
03456. Submissions not selected for publication wilt be returned if
an SASE is enclosed,

+ I5V LIME

SMALL SIGNAL NPN
TRANSISTOR- 2 N2222
OR SIMILAR

LED

I INDICATOR]

circuit FOR

SMART PANEL LAMP'

AS DESIGNED FOR
REGULATED I3tf LIAC

SMART PANEL LAMP: This
power-on indicator for your reg-
ulated rS-V supply also indi-
cates overload conditions (cur-
rent-induced voltage drop) and
can be easily modified for other
voltage levels. Two resistors
sample the output voltage and
compare it with the 2.2-V
reference defined by the LED
and transistor emitter-base-
function voltage drop. If the
regulated 15-V line drops by
about a volt, the indicator LED
goes out The 7k resistor in the
coilector circuit limits the cur-
rent draw to 15 mA so the indica-
tor won't burden the supply.—
Penn Ctower W1BG, Andover
MA.

INVERTED-V TUNING TRICK:
Tuning the invened-V antenna
requires adjustment of both the
enclosed angle and the length
of each side of the dipole. You
can take the pain out of length
adjustments by fastening the
ends to the insulators with split
bolts. These come in various
sizes, and t recommend using
the kind made from bronze. —
Wm. Bruce Cameron WA4UZM,
Temple Terrace FL

WATTMETER
CIRCUIT SOAHO

PEfVJWG SWITCH

S-i_UG TERMINAL
5TWP tqftQuNO
LUG NOT USED)

TR4N&FONUE.H

PEf/AVG Switch

REMOTE SENSOR

QOK MOUNTING HOLES

ABLE CLAMP

OC
INPUT

SELF-CONTAINED BATTERY ELIMINATOR FOR THE HEATH
HM-2140: This simple circuit is built into the wattmeter cabinet and
doesn't interfere with the internal mounting of the remote sensor
box. The PEP/AVG push-button switch has an extra set of contacts
which can be used to switch the power supply on when PEP read-
ings are desired. The LED is centered between the meters on the
front panel. The fuse holder can be an inline type or be mounted on
the circuit board behind the battery clip. Note that the negative side
of the power supply does not go to ground, ff you don 't plan portable
battery operation in the future, the 8.6-)/ output can be permanently
wired to fug 2 of the PEP/A VG swttch. The transformer is mounted
between the existing screw near the battery clip and a spacer In*
stafied on the bottom cabinet. A five-lug terminal strip mounted with
the transformer at the corner of the circuit board will hold the other
components, and a cable clamp on the other side of the transformer
secures the tine cord. If a type 7608 three-terminal regulator is not
readily available, an LM317T adjustable regulator (Radio Shack
H27&1778) can be substituted,— Wayne Arnett AI7C. Chandler AZ.

POLARITY PROTECTION FOR PLUG-IN RADIOS OR OTHER SOLID-
STA TE DEVICES: By adding a diode or a diode bridge in the dc pow-
eHnput circuit, you can have complete protection against ever con-
necting the unit backwards, With the bridge circuit, it makes no dif-
ference which way the connection is made. However if the diode Is
connected in reverse, there will be no current to the unit due to
blocking action of the diode. When connected correctly, diode will
conduct and the unit will work. Using this with plug-in radios, mount
the bridge or diode inside the chassis. Be sure the bridge or diode
will handle the maximum current requirement. — E. A. Rowe
W7PWQt Chelan WA.

HAM HELP

We are happy to provide Ham Help list-
ings tree, on a spaceavattable basis. We
are not happy when we have to take time
from other duties to decipher cryptic
no res scrawled illegibly on dog-eared
postcards and odd-Sited scraps of paper.
Please type or print your request (neatly*),
double spaced, on an 8Vt"xH" sheet ot
paper and use upper- and lowercase let-
ters where appropriate. Also, please make
a "1" took tike a %N not an %» which
could be an "el" of an ''eye*' and so on.
Hard as it may be to believe, we are not fa-
miliar with every piece ot equipment man-
ufactured on Earth for the fast 50 years!
Thanks tor your coopera Hon.

Aboul three years ago I built a CMOS
digital thermometer out of Poputer

Science magazine Trie probe uses a
Texas Instruments 6 8k Tm-1/4 senststor
with a positive temperature coefficient I
haven' t been able to iind this part— can
anyone help?

David Shoaf WD4CZW

Rt. 5 Box 375

Mocksville NC 27026

Just a not© (o some of the readers con-
cerning; "Ham Help." If someone sends
you the information you need, please
send an acknowledgement back to that
person, perhaps Including the postage.
After all, he or she went out of the way to
find and copy the material for you

I don't know how many people respond
lo these requests for help, but in April I

mailed 78 pages of information to 7 differ-
ent hams. Only one person, a teacher, re-
turned a note Of thanks. In January it was
5 sets Of information— with no replies.

I'M strH send the stuff out, but I wonder
what happened to the spirit of amateur
radio?

J.V- Lem KB6BO

5222 Coring* Drive

Los Angeles CA 90042

Has anyone been successful In convert-
ing a Swan 6000 to a 500CX? I aJso would
like to increase the stability of the 500D,
and to overcome its trans mi t-to- receive
problem,

John Matthews K6VS

12208 Huston Street

North Hollywood CA 91 607

I will pay for any data concerning the
Nems Clarke UHF receiver model 2801 A,

John Elmquist

3308 Bahama N,E.

Albuquerque NM 87111

f am interested in obtaining a National
NCX-1000 or NCX 2000, used Of recondJ
ttoned. Write with price and condition via
airmail to:

Fermin Anzaiaz LU1SH

PO Box 155

5300 U fiioja

Argentina, South America

I need manuals for a Lavot spectrum
analyzer LA*17 and a DEI telemetry-
receiver tuning untl T-1G2-A 12 16-260
MHz I. Will pay reasonable costs incurred.

Paul Veltman WA80KG

5333 York Drive

Fremont C A 94536

Would someone please help me find a
schematic or manual for a Communica-
tions Power, Inc., model WM-1000 watt-
meter? I will gladly pay for any costs in-
curred.

Richard Whipkey AD6X

866 Yolo Way

Li verm ore CA 94550

73 Magazine * November. 1984 75

WEIV PRODUCTS

JENSEN OFFERS FREE CATALOG

A new catalog oi precis ton tools ts of-
fered free by Jensen Tools, Inc. Illustrated
In full color, the 160-page catalog con
tains more than 3,000 tool a of interest to
field engineers, technicians, comput Br-
and telecommuni cat ion -service persons,
and electronic hobbyists.

Major categories covered are test
equipment, soldering equipment, tweez-
ers, screwdrivers, cutters, drafting sup-
plies, power toots, computer accessories,
circuit-board equipment, and miscellany.
Also included are many new prod-
ucts from Jensen and over 40 pages of
service Kits and tool cases for electronic
specialists and technicians.

To obtain a free copy, write Jensen
Toots, inc. 78 1 5 S. 46th Street Phoenix
AI 85040: (602^968-623 1 Reader Service
number 482.

SPECTRUM COMMUNICATIONS'
SCR2000X REPEATER

Spectrum Communications1 SCR2000X
micro processor-control led repeater com-
bines the latest digital techniques with
Spectrum's highly ret 4 ned rf technology
to yield an advanced, high performance
repealer system

Standard features include: full auto-

patch and touch tone^^ rernote-contro!
capability, phone-line and overthe-air
command modes, up to 13 autodial tele-
phone numbers, a touchtoneto pulse
converter, rull 16-digtt decoding, up to 6
auxiliary functions, automatic CW Identi-
fication, and built-in battery backup for
the microprocessor's memory In case of a
power failure.

Several power levels are available from
30 to 75 Watts on 144, 220, and 440 MHz:
High-power rack-mount repeater power
amps and power supplies are available up
(o ISO Watts.

For more details, contact Spectrum
Communications Corp., 1055 W, German-
town Pk.t NorristQwn PA 1 9401 -9616;
(2J$)-631-1710. Reader Service number
478

DOCTOR DX BY AEA

Doctor DX by AEA is a complete CW
contest simulator packaged in a plug-in
cartridge tor the Commodore 64, II Is a
computer simulation of the COWW DX
Contest, allowing you to work the HF
bands using a computer-generated mod-
em-style transceiver and omnidirectional
antenna.

AM of the stations you will work using
Doctor DX are generated by I he computer
As you tune up and down a particular

AEA's Doctor OX contest simulator

band, you will hear stations contacting
other stations, plus QRM and QRN. slmi-
lar to onthe-air conditions. Station pre-
fixes are generated according to interna-
tional caMsign-ai location conventions,
and are weighted according to amateur-
operator density. The speed of the sta-
tions at the lower end of the bands Is
much faster than that of stations higher
up, and the low-end operators have greai-

er "savvy."

The propagation programmed for each
band ts driven by a real-time clock, with
conditions varying by the time of day and
band selected. Band conditions are simu-
lated tor a sun spot -cycle peak for a sta-
tion using an omnidirectional antenna.

A typical two-way contact involves ex-
changing callsigns, signal reports, and
COWW zones. I! you miss pan of a report,
you may ask for and receive a repeat if
you make an error, the simulated station
will request a repeat. You may also re-
quest the o I her station to QHS or QRO,

Doctor DX approaches reality in its op-
eration. AEA even offers award certifi-
cates to operators who work all zones, DX-
CCp 5 band DXCCr or qualify for the Doctor
DX Honor Roll.

For detailed information on Doctor DX,
contact Advanced Electronic Applica-
tions, fnc, PQ Box C21GQ. Lynn wood WA
98Q36; (206}T7$-7373

OMNfTRONSX RS-232 INTERFACE

Omni iron in has announced the release
of their Deluxe RS-232 Interface for the
VlC-20. 064, and SX64. The RS 232 inter-

face has been designed to allow easy use
of any type of RS-232 equipment, includ-
ing serial printers and modems- The inter-
face plugs into the user I/O pod Q* the
computer.

Included as part of the unit is a three
foot cable terminating in a mate or female
DB-25 connector The Deluxe RS-232 Inter-
face can also be supplied with a PC-
board mounting female DB-25, allowing it
to replace the 1011 A, Three switches in
the case cover allow you to set the unit for
DTE/DC E. invert pins 20 and 5t and select
the Busy line polarity. The RS-232 inter-
face supports virtually all RS-232 signals
including Ring Detect and can operate at
up to 2400 baud, The manual includes a
type-in Basic terminal program and a tuto-
rial on using the RS-232 port

For additional information, call or write
Omnrtionix, PQ Box 43. Mercer island WA
98040; {206}- 236 2983 Reader Service
number 430.

HALS IBM/RTTY INTERFACE

HAL Communications Corporation Is
offering their new PCI 2000 RTTY Inter
face module for Ihe IBM-PC™. Features
Include full Bell 103/202 support.
170M25/B5Q-HZ shift, direct FSK output,
45-1200-baud transmission rate, and
Morse, Baudot, or ASCII codes.

The supporting software incorporates
such features as split-screen formatting,
transmit and receive buffering, and disk
file storage and retrieval. All PCl-2000
parameters are Set using the PCs FN
keys.

Spectrum Communications' SCR200QX repeater*

76 73 Magazine * November, 1984

Commodore RS-232 Interface from Omnitronlx.

*Mb'.

HAL's IBM PC RTTYtCW interface.

The Robot 12Q0C color SSTV converter.

For further information, contact HAL
Communications Corporation, PO Bom
365, Urbarta !L 67301; {21 7> 367- 7373
Reader Service number 464.

HI RES COLOR SSTV
CONVERTER FROM ROBOT

A new high-resolution color SSTV con-
verier has been added to Robot's line of
amaieur-radio products. Designated ihe
Mode) 1200C. ft is capable of transmuting
color video images that rival broadcast
television in picture quality. The Model
12DDC has three selectable frtrit memory
planes that combine to form 262,1 44 color
combinations in a 256 X 240 line lull-
screen display.

Eight different brack-and-whlte- and
color-transmission lormals are available
with automatic selection on receive. Lip to
six separate pictures may be stored in
memory. The unit accepts cater or black
and-white composite video from standard
TV cameras and has RGB, composite, or
rf -modulated video output.

A unique feature of the Model 12DQG la
the 8-bit parallel I/O porl lor computer in-
terfacing, This allows total access to each
Individual pixel by a host computer for im-
age processing, transformation, storage
and recall, and graphics This port also
allows connection to a printer for black'
and-white or color hard-copy picture
printing.

The Model 1200C features touch- sen si
tJve front-panel switches for lull station
control and several automatic functions
Fine tuning, speed switching, and color or

black-and-white detection are automati-
cally accomplished without operator in-
tervention.

For further information, contact Robot
Research, /nc\, 7S91 Convoy Ct.t San
Diego CA 921 If; (619)-279'943Q.
Service number 479.

UNIVERSAL AUDIO FILTER
FROM PALOMAR

Palomar Engineers has announced a
new universal audio filter. Model FL-A is for
SSBrCW/Hm and features swrtched-ca-
pacltof filters. A 10-pole low-pass and an
6-poie high-pass can be moved anywhere In
the 200-2500-Hz range to form a sharp
bandpass filter at any frequency and of any
bandwidth. A notch filter Is also included-

The filter connects to the receiver's
phone jack and provides 2 Watts of audio
to drive a speaker. The on-off switch by-
passes the filter when not En use. It oper-
ates from 15 V dc

For further information, contact Patomar
Engineers, Box 455, Escondido CA 92025.

SIMPSON PANEL METER
CATALOG

Simpson Electric Company is offering a
new four -col or catalog, number 5400- P.
The catalog lists Ihe entire Simpson line
of over 1500 US-made analog and digital
panel meters, meter relays, and control-
lers. Also listed are panel-mount chart re-
corders

Simpson, manufacturer of the world-

The Palomar FL4 Universal Audio Fitter.

famous 260 VOM, Is a member of the Ka
!y Industries, Inc., Electrical Equipment
and Products Group. For a free copy of
Simpson Catalog 5400-P, write to Simp-
son Electric Company, S53 Dundee Ave-
nue, Figin H 601203090: f3l2h69T-2260
Reader Service number 483,

ISS HALON EXTINGUISHERS

International Safely Systems, Inc., (ISS)
has announced two fire-flghHng products
designed specifically for consumers,
using Halon, a colorless, odorless, electri-
cally noneonduchve vapor.

Hal on chemical I y Interferes with the

combustion process by breaking up its
complex chemical read Ions, while other
extinguishing agents only smother the
fire, ft is extremely low In toxicity, does
not damage property, leaves no residue,
and has a twelve-year shelf life.

ISS's Halon products consist of two
models; the 12-C and the 24-H, containing
.75 lbs and 1.5 lbs of Halon. respectively
The smaller 12-C is ideal for placement In
an auto glove compartment or In a k lich-
en. The 24-H is excellent Tor a light air-
craft, cam per r or workshop.

For further details, contact tSS, 2221
tdtewood Rd., Suite 4, Tucker GA 30084
Reader Service number 485.

REVIEW

BREAK COMMUNICATIONS

SYSTEMS EQUIPMENT

CONSOLE

Amateur equipment comes in all
shapes, sizes, and Sevens of complexity
But whether you're using the latest solid-
state marvel or a venerable old "boat an-
chor," one piece of gear is an absolute
necessity: some sort of operating table or
console.

After years of operating from various
tables with mixed results, I recently took
the piunge and acquired an equipment

console from Break Communications Sys-
tems <BCS>, Inc. it not only provides a con-
venient and rugged operating position,
It's also a superb-looking piece of fur-
niture.

Description

As the photos show, the BCS console
consists of a desk lop or writing surface
and a gently sloped front panel with cut-
outs to allow the front of each piece of
equipment to protrude through. Behind
the front panel is an aluminum and steel
support rigging that carries most of the
weight of the gear. The holes in the tront

panel are cut by a computer -driven saw to
fit precisely around the equipment with tit-
tle or no "slop " The front panel is at-
tached to the console with a number of
heavy steel clamps, allowing replacement
of Ihe panel when new equipment i$ ac-
quired.

The console is constructed of hard-
wood. 1J2" and 3M" plywood, and 1/2" par-
ticle board. BCS consoles are covered in a
high-pressure laminate (the generic name
for materials such as Formica] Standard
consoles are four, six, or eight feet wide
and weigh from 150 to 350 pounds without
radio gear. Many accessories and options
are also available, as are L* and U-shaped
consoles.

Designing The Contois

No two hams have the same radio gea*"
or operating habits Therefore, the ideal
operating console should be customized
for every ham. The key to customization in

the BCS design is the front panel, which is
cut to accept the equipment in any ar-
rangement desired by the customer. BCS
has developed some interesting tech-
niques that allow the creation of front
panels with precisely-cut equipment
holes without the need to actually lay
their hands on me gear. Getting me con-
sole exactly right becomes a cooperative
effort between BCS and each customer.

Once the basic size of the console is se-
lected (for my equipment, a sis-footer was
just right), then begins the process of de-
termining the exact size and shape of
each hole BCS will cut in the front panel. It
starts with BCS sending the customer a
basic measuring kit and wooden tem-
plates or "test cuts" for any of the gear for
which BCS has previously cut front-panel
noles. The customer must carefully mea-
sure any equipment BCS has not dealt
with before, Also, each template must be
carefully checked to see that It fits per-

73 Magazine ■ November, 1984 77

K:-^l^.-

,. ■'" , V::M ■

WBBtGW

— rJ"-r

■

j # j i ■ 1 i J i ' f t ■ 1

■ MM

■ k *.- ■* i. Vfc ZL * ■:

Rear view of BCS console, showing the equipment support rigging, the cutouts in the

front panel for radio gear, and the steel c tamps f around the perimeter} which hold the
front panet in pface.

fectly around the front of its respective
gear. It I urns out lhat rna n u fact u ring toler-
ances allow for considerable variation in
the dimensions of rigs of the same model,
so BCS gives customers a special form on
which to indicate how each template
must be modff ted for a perfect fit.

All measurements and template modifi-
cation instructions are phoned or malJed
to BCS, which then sends out a complete
new set of wooden templates for any rigs
that weren't perfect the first time. This se-
quence of template modification followed
by new templates continues until the cus-

Closeup of a portion of the steet and aluminum support rigging. The venicat members
are i 12-inch threaded rod,

tomer has a template that fits each piece
of gear as precisely as possible, the goal
being no more than O.OS" of slop,

Trie arrangement of the equipment on
the front panel is what makes the differ-
ence between a station that is easy and
efficient to operate and one that is (literal-
ly) a pain In the neck. A poorly-pianned lay-
out can have the operator forever si rain-
ing to reach an often-used accessory. For
its part, BCS sends each customer a one-
half -scale mock-up of the front panel,
along wUh one-half-size cardboard cut-
outs (eaNed "puppets1} In the proper
shape of each piece of equipment. It is
then up to the customer to move the pup-
pets around the front-panei mock-up until
the best layout is found.

Once the templates fit properly, the
front panel is laid out, atl options are spec-
ified, and (he color scheme is selected
(not easy — there are thousands of choicesi),
then the console can be prepared and
shipped in about two weeks. Total elapsed
time from the start of the design process
is six to eight weeks. It took a bit longer in
my casei but only because I didn't re-
spond as quickly as I might have when
new templates were shipped to me. Total
time invested on my part was less than
three hours.

Performance

The BCS console is worth waiting for.
Overkill is the only word to describe the
protective shipping crate in which my con-
sole arrived. I've never seen sturdier pack-
aging. Assembly was a snap, even for one
person, and can easily be accomplished
In an afternoon. The only tools required
are 9/161' and 3/4' * open-end wrenches, al-
though a socket wrench makes the Job
much easier, i encountered no problems
whatever.

Mounting the equipment Is equafiy un-
dramatic The rugged metal support rig-
ging was set up at the factory for my
equipment layout and worked exactly as
advertised— very solid. Minor adjust-
ments were made to square up each piece
of gear with the front panel, and I found it
convenient to remove the rubber feet from
some pieces. The consoie can be rolled
about easih/ on its heavy-duty casters and
the back is open, allowing access to the
rear panels of ail gear, There is also plenty
of room in the rear of the console for ac-
cessories such as power supplies, VHF
amplifiers, and other items not requiring
front-panel space. An optional drawer/
bookshelf unit provides a handy place to
store things lEke logbooks, message
forms, and spare fuses.

Conclusions

There are pluses and minuses to this
type of operating console. On the plus
side, there Is the complete absence of un-
sightly wires and cabling, having all
equipment within easy reach (yet not plied
on top of itself), the convenient access to
the rigs from behind, and the knowledge
lhat if I ever buy new equipment, I need re-
place only the front panet and support rig-
ging for a relatively email fee. Equaiiy im-
portant, perhaps, is the feeling of pride
one gets in operating from such an im-
pressive looking console, it's like having a
seat at mission control,

On the other hand, a ham who replaces
his gear frequently, or who likes to rear-
range his operating, position once a
month, may find it prohibitive to replace
front panels so often. For my purchasing
patterns and operating style, it presents
no problem, as it is usually two or three
years between major changes at WB8BTH.

In summary, I couldn't be more pleased
with my BCS console. The workmanship
is first rate, and the consoie Is built like a
tank. Larry Kushner WA6BKCM and his
crew have done a fine job.

Prices for BCS consoles start at $600.
For more information, write Break Com-
munications Systems* inc., $81? SW 21st
Street r Hot ty wood Ft 33023. Reader Ser-
vice number 486,

Jeff DeTray WBSBTH
73 Staff

MIZUHO MINIATURE
SIX-METER NIULHMODE

A couple of years ago at the Day ton
Hamvention, \ saw a little Japanese trans-
ceiver kit for sale. It was about the size
and shape of an ICOM 2At but It wasn't an
FM rig. It was a sideband handie-talkie
with only a quarter-Watt output; the
Mizuno MX-6Z. Amusing, I thought, but
not really serious. It turned up again in
1983 at Dayton and began to be advertised
in the ham magazines. Three models were
now available, covering 15, 6 and 2 me-
ters, plus amplifiers for the 15- and 6*me-
ter units and some accessories. So they
were serious after all! Curious about what
sort of rig It couid be, \ bought a pair of the
six-meter versions, (A pair, to ensure
someone to taik to. I wasn't sure what sort
of 6-meter activity there was here in east-
ern Tennessee).

Assembling the kits turned out to be
quite simple, taking only about 45 min-
utes each, despite some missing steps In
the English-language instructions. The
full Japanese instruction set was includ-
ed too, with enough drawings to make up

The completed BCS consoie, ready to receive the station equipment. My Meyer, an unusu*
ally-shaped piece of gear, is already in place, having been custom-mounted for me at the
factory.

78 73 Magazine • November, 1984

Ortty the faceplate of each piece of gear protrudes through the front panefr giving the

consoie a sophisticated look.

MICA COMMUNICATIONS CONSOLES

4 -6 -8' Wide- t to 8 wtde optional
l & u & Circular set up's- iwr/T optional comer mote
Replaceable Front Panel - for station changes
Precisely cut panel fto\^ - ov computerized woodcutter
High station &er\s\zy - because no stietves are used"
Hidden accessory $h&f- for power wM&l&s flitmriwiaxd
Puppets Of all your equipment- for easy station tayoar

OPTIONAL ITEMS:

Drawer 'Bookshelf combination - hangs under cte^k
1000 Mica's to select from - to march your oecor
Desk recessed for keyboard -optimum 2$ typing nerght
Desk top extensions : into panel - for apple computer or storage
Dwtef inquiries hunted JVJatchmgdQllyforfEoorampS- with conceaiea caster*

Shelf under desk, quick access - for headphones xtv mic
Exhaust cooling fan system - thermostatically controlled
Wire duct wire labels, etc..

Break
Systems, Inc.

5817 S.W. 21st Street. Dept. 73 • Hollywood Florida 33023

Phone (305) 989-2571

. . . at last . . .
your shack organized!

A beautiful piece of furniture - your XYL will love it!

$184.50 S-F RADIO DESK

DeJuxe - Ready to Assemble

Also Available . .
•\oor Space: 51" Wide by 30" Deep

$199.50

Designed with angled rear shelf for your
vfewirrg comfort and ease of operation

FINISHES: Walnut or Teak Stain,

Floor Space: 39" Wide by 3D" Deep

Additional Information on Request.

Checks, Money Orders,. BankAmerieard
and Master Charge Accepted

ROB Culver City, (fn Calif. Add 6% Sates Tax.)

.. DEALER INQUIRIES INVITED

S-F Amateur Radio Aivice/

j>**65

4384 KEYSTONE AVEMUE * CULVER CITYT CALIF. 90230 - PHONE (213) 837-4870

UP YOUR ERP*

For HT owners operating inside a vehicle and wanting
increased T7R range, RF PRODUCTS has the low cost
solution.

Remove your BNC antenna from the HT and mount on
the HF PRODUCTS BNC magnet mount, install the magnet
mount on the roof top and connect the BNC coax connector.

The magnet mount (part no. 199-445) has 10 feet of small
(5/32") co-ax with BNC connector attached and is priced at
$15.95 (including shipping by UPS to 48 states)-.
TO ORDER ■ send St 5,95 money order or cashiers check only

Fla. residents add 5% tax, tor air UPS add St .SO

The RF PRODUCTS Magnet Mounts are one of the few magnetic antenna mounts available
that can be repaired should the co-ax cable be damaged. The co-ax cable connector includes
a shrink tubing strain relief for long life at the connector/cable flex point (an RF PRODUCTS
exclusive on all cable assemblies).

Eight other models avai lable with three each choice of antenna connectors, co-ax types and
transceiver connectors (BNC, M/8-T8, 5/16-24 & RG-122U, RG-58A/U. mini 8X & BNC,
PL~259.typeN).

RF PRODUCTS

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m*277

THE

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An ultra high quality encoder for absolute
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control, no frequency drift, operates in temp-
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hardware. Call or write for free catalog, dealer's list and information guide.

PP-1 S55./PP-1K, S.P.S.T. Adj. Relay $62 P-3, 12 or 16 Key.for custom
PP-2, $597PP-2K S.P.S/T. Adj. Relay $66, installation, flush mount, 3 different
M Series = Detached frame for irreg. install. circuits avai I able- request P-3 info.

PATENTED
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Order

tpipotSommunications

Emphasis is on Quality £ Reliability

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Holfywoodr California 90028
(213)852-1515 ~15

TOUCH TONE
CONTROL

OUR NEW C&16 DUAL PASSWORD
DECODER BOARD IS THE FINAL
SOLUTION TO REPEATER
CONTROL SECURITY

16 latched on/off functions

Open collector (can driv9 relays direct-
ly) and logic outputs for each function.

Two separately programmable three
digit passwords allow hierarchy control

Primary password can access all 16
functions

Secondary password can access 8
functions

A primary password command can
enable/disable secondary password
control

Can be strapped to operate without
passwords

Adjustable p re-amp accommodates
10MV-2V input

Retransmission of control tones can
be eliminated by use of either open
collector or data strobe logic outputs

Power up reset

XTAL controlled tone decoder

Operates from 10 VDC to 25VDC.
Reverse polarity protected

Standard 4%"x61/z'r glass board with
44 pin gold plated edge connector.
Hofes permit hard mounting

Comes complete with manual and
mating connector

30 day return privilege

Limited six month warranty

CALL OR WRITE FOR BROCHURE

EH $149

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Torrance, CA 90505
Phone (213) 373-6803

73 Magazine * November, 1984 79

The Muutio MX 61

lor (tie missing info. Tnere were also some
suggested modifications in the Japanese
Instructions, sucti as an S meter it hough I
don t Know where you a mount it!}k a
transmit light, and a CW sidetone. which
arent Ifi the English version. The two cir-
cuit boards were already assembled, test-
ed, and mounted, leaving only a little wir-
ing and case assembly to do Two types of
battery holder were provided; afhfoll tran-
slstor-ballery connector, and a holder tor
six AAA cells. I recommend the latter,
since ihe unit draws enough current to de-
plete almost any 9- vol I transistor batlery
in short order.

Both units worked as soon as power
was applied, and no tune-up was neces-
sary (no instructions were provided &
May) imnai tests wuh bench supplies
showed a need tor a little more bypassing
at the external power mput lack on the
bottom of the case a*nce the suppled ex-
ternal-power cord was radiating more

than my dummy load! A ,001 uF ceramic
across the dc-inpul terminals quieted
things down. One unit put 275 Watts into
the load on CvY and SSB voice peaks, the
other a little less. However, both drew 220
mA from the 9-V supply while doing it Cur-
reni drain on receive is about 40 mA. and
tOO mA during key-up transmit A regular
carbon-zinc transistor battery went flat
very quickly under the strain, so I switched
to alkaline AAA cells which have held up
pretty weft in light usage. A separate pow-
er supply or external battery pack Is really
necessary tor any serious long-term oper-
ating. It looks to me as If a batlery pack
from an (COM 2A would fit perfectly on the
bottom of the case if if could be attached
securely,

Initial tests in the field (literally a field!)
showed that the little units have good
audio quality and frequency si ability on
both transmit and receive. The tiinch
"super rubber ducky" antennas supplied
gave perfect copy at a range of a half mile
with a hill and building in between. The
tuning knob is on the top of the case and
controls a variable crystal oscillator with
a range of 50 kHz. A "band" switch next to
it switches between either ot two crystals
(one is provided, for 50.2 to 5025 Mb
giving It a total of i 00 kHz ot coverage, The
necessity of tuning in the other station and
the lack of squelch are a little strange
at first when your only other hand-held ex-
perience Is with 2-meter FM- Perfectly nor-
mal on HF sideband, but unexpected In a
handle, The transmit button Isn't a push-
lo-talk type. It's a latching swllch—
push once to transmit, again to receive
Since the MX-6Z also transmits CW (from
a liny button on the top panel or through a
miniature jack on the bottom), this does
make some sense. Tne internal micro-
phone is an elect ret type, and there is an
externa I -mike Jack on top ot the case next
to the headphone jack. A noise-toianker
switch is below the tuning knob, and the
blanker does seem to work pretty well on
Ignition noise, an important consideration
on six meters.

As you'd expect in any unit that packs
this many features into so small a case,
the Circuitry is pretty simple. One of the

1 wo PC boards is devoted to rf, and the
other to i-f, sideband generation, and
audio, The receiver Is a single-conversion
lype wrlh a fixed-tuned dual gate MOSFET
rt amplifier stage. J measured the sensitiv-
ity tcrudefy) as about 0.8 uV tor 2Q-dB sig-
nal-to-noise; I could hear a signal at 0,1
uV, The i-f frequency is 7.8 MHjt, and the
tiny crystal titter seems adequate on both
receive and transmit. A quick and dirty
check showed a 6klB bandwidth of about

2 kHz, from rf in to speaker out. The trans-
mitter has three "power amplifier ' stages
lot lowing tne transmit mixer. Ihe firs I of

Mizuho MX 61 controls,

80 73 Magazine * November, 1984

which is a dual gate MOSFET which is
keyed for CW, All of the stages are broadly
tuned and inductively coupled except the
final, which is a muili stage pi type Trans-
rmr-receive switching is done with diodes
and is accomplished with a closure to
ground, so CW break-in operation might
be possible with a simple modification.
Audio output and quality is pretty much
on a par with other handie-talkies, with an
LM386 audio-amp IC driving a twr>lnch
speaker

The besl part ot this little rig is that it's
fun! It really works pretty well tor Its low
power. When six is open, no I much power
Is needed i of course, and when the band Is
closed, not much will help, One of the first
contacts I made after building and testing
my MX -6 was with a south Texas station,
followed by contacts with Oklahoma and
Minnesota, ait between 800 and 1000
mttes from my Tennessee GTK This was
done with an 80-meter dipole. Since I
didn't have a Six-meter antenna up* A
prooei antenna and more power would
help a lot. ORO is available in the form ot a
5-VYatt amplifier, the FL-6.

Ultimately, this Nile rig ts likely to be
used for portable or mobile work such as
mountaintopping, Its small tuning knob
and limited tuning range, to say nothing of
its low power, will not make It a favorite of
hardcore six-meter operators, but it is a
nice cheap way to get on six-meier side-
band. I us© mine mostly for local monitor-
ing and checking for band openings,
tasks for which Ihe rubber-ducky antenna
works fine When activity occurs I can
hurry lo the shack and plug in the outside
antenna and sharpen up my QRP opei<
at in g skills. One of these days I'm going to
get a portable six -meter beam and hike up
into the Smoke y Mountains and hope lor a
band opening. Then the MX-6 wilt realty be
m its etamenf!

For further information, contact Ace
Communications, 2832-0 Watftut 4ve,
Tustin CA 92630; i7i4y544^S2ST Reader
Service number 477.

Mark Nelson AJ2X
Kno* villa TN

YAESU FT-726R

Remember the advertising Oil about
'Who put eight great tomatoes In that Ut-
ile bitty can*- I ihtnk I know who did it.
and they now work for Vaesu! The fea-
tures packed into Yaesu s FT-726R go be-
yond those of the early all-mode rigs to
create a truly impressive radio A glance
at the front panel finds controls usually
associated with an advanced HF rig rath-
er than a VHF one. One's choice of options
centers largely around band preferences
rather than operating modes or signal pro-
cessing. More about that in a moment,

The FT-726R comes with 2 meters as
standard equipment, with provisions lor
installing two optional modules for other
bands. Available modules Include those
for HF (15, 12, 11, or 10 meters). 6 meters,
and 70 cm {43Q-44Q MHz of 44Q-4S0 MHz),
with thinly veiled rumors ol forthcoming
220- and 1296-MHz modules, The optional
satellite module permits full-duplex
cross band operation via OSCAR or R5
satellites Operation on LSB USB, CW,
and FM is standard. No optional speech
processor or noise blanker here, both are
standard As in most digitally -tuned rigs,
there are two vfos plus memories, along
with scanning features. A microprocessor
keeps track of the mode of operation and
controls the memory and scanning func-
tions Receiver performance ts enhanced
by controls tor age time constant, it shift,
■ -t width, rf gain, audio tone, and clan Me r
{RlT)r Provision Is made tor installation of
a CW Hlter,

Impressions

The review unit was equipped for the
satellite enthusiast and casual operator
on 2 meters and 70 cm. Modules for 2 me-
ters, HF, and 70 cm were installed, along
with the satellite unit and a 300- Hz CW
ter imodet YK-455 SMCty Even after oper-
ating a variety of gear over the years, my
initial reaction to the front panel was one
of mild panic— how could I master all
those (41 ») controls? A look at the rear
panel, though, found It surprisingly
'clean' with jacks for key, 600-Ohm audio
output, external speaker, external push
1o talk, and power. Each module has two
rear-panel Sacks: the separate coaxial
connectors that allow bands-witching
without swapping cables, and companion
3.5-mm jacks which provide ground -on-
transmit to energize an external amplifier
on the appropriate bend. It was reassuring
to find a type H coa* fitting on the 7&cm
module.

It didnl take long to find room for the
726— it can replace si* boxes in my
shack1 A closer look at the front panel and
perusal of the operating manual snowed
that the controls are logically grouped,
and later operating bore that out. Don t
think you can make this radio do all its
tricks without looking at the manual,
though.

A word on the manual itselt is In order
here It is definitely an operating manual.
There is no Iheory ol operation or detailed
parts layout. Complete installation and
operating instructions, schematics, and
block diagrams are included, as well as
procedures tor installation of options The
only fault I could find with the manual
turned up when I tried to operate through
OSCAfl 10 and the 726 seemed to gel "con-
fused, ft turns out that when operating
crossbanrt full -duplex, the uplink and
downlink modules must both be in CW or
both be in SSB A ISBAJSB mix works; a
CWrSSB combination does not. The man-
ual isn't too clear on this.

OSCAR 10 operation was good when
using a 16-element linear vagi on 435 MHz

and my four-yagl EME array with tower
mounted prearnp on the downlink. A later
attempt on Field Day was not so success-
ful when using the same uplink antenna
and a 10-element "twist" downlink anten-
na with no prearnp. Reasonable perlor-
ma nee coutd probably be expected with
circular polarization on uplink and a
downlink system between the extremes
tried here

Moonbounce operation proved the
worth of the i f shift and width controls
and the 20-Hz clarifier steps in enhancing
weak-signal readability. The results were
so dramatic that t didn't even try the out
board audio filter I usually use, Semi
break-in CW is smooth at about IS wpm.
but the delay m too short for the slower
speeds used on EME— the extent PTT
could be wired with a toggle switch to get
around this, incidentally, II appears that a
variable resistor (VR07 on the tx unit) con-
trols break-in delay, but It Isn't mentioned
anywhere (Nor Is VR08, which controls
sidetone volume. Opera ting manual, re-
member"31

The 726 was pressed into service on 70
cm during contest operation from a hilltop
near Ithaca HY. Inter mod problems from
an FM station 2 mites away on the next hill
disappeared when we substituted the FT-
726R for our usual 432 rig Receiver sensi-
tivity seemed good and the transmitter
drove a solid-state amplifier nicely The
other operators in our muEti-op effort mas-
tered the rig's essential controls qutt
and easily

Assorted Piuses and Minuses

The CW lllter has Its own front^ panel

control and mat's great? Hats off to the
engineer who gave the filter in/out choree
to the operator and made clockwise rota
hon of the tuning Knot) increase frequen-
cy On the negative side. I found the CW
sidetone cficfcy to (he point of being
slightly annoying especially in head-
phones. A few spurious signals turned up
m the HF region even when the antenna
was replaced with a good 50-Ohm load.
The spurs didn't snow up on 2 meters or 70
cm. PoweMine noise had to exceed S3 on
the S-meter before the blanker had an ef-
fect Supn singly, the blanker could do
nothing with ignition noise from my neigh-
bor's lawn mower. It's obvious that noise
e lime and level both determine how
effective the blanker will be

The Bottom Line

Overall, the FT-726R gets very good
marks Any faults I have noted are minor
in comparison to its performance and tea-
lures. It Is evident that a lot of common-
sense thinking went Into the design of this
rig, Learning to sort out all the controls
was painless with the aid of the manual.
The ability to hop back and forth between
a 1 0-meter sporadlc-E opening dnd 432-
MHz activity at the flip of a switch is quite
remark able. Even while writing this, Tm
letting the rig scan the various calling fre-
quencies in hopes that one of the bands
will open'

For further details, wtite or call Yaesu
Electronics Corpora t Jon. 685 1 Walthall
Way, Paramount CA 9Q723; (2l3iS33^007
Reader Service number 476

Richard ft. Farman K2QR
Endicoti NV

THE KANTRON.C$ INTERFACE l(

As an amateur enthusiast of some
twenty-four years turned compuier crazy. I
am particularly interested in software and
hardware packages that can be used in
the ham shack. While the actual sending
of CW, RTTY, AMTOR, and ASCII is Jlduck
soup" for virtually any home compuier.
the need for an Interface between the
compuier and the ham equipment is still a
necessity, I've previously had the chance
to review the original Kanironies interface
and the AEA GP-1, but I was anxious to
see how the Kanironics interface il would
perform Here are The results of my "on-
line" tests.

The first Ibmg that struck me is the size

Interface H

"*l

M «" Kantronics

The Kantronics inter face II

ol the unli. It Is small! I guess it must be
my vacuum-tube background, but I always
expect things that do a big job to be larger
than they really are

The next thing ! noticed is that tike
many accessories these days, the unit
does not contain or come with its own
power source. I suppose this saves a few
bucks and some amateurs would rather
power everything off of one big twelve-voFt
supply I'm not one of them.

The original Kantronics Interface,
though it performed well, was sort of a
minima) TU for anyone who has ever used
more expensive units. The interference-
r eject i on and si gnat-lading capabilities
were not very good. The single bar-graph
LED tuning indicator left a lot to be de-
sired. Bie original was designed only for
1?0-Hertz-3hift signals, it could be made
to work on other shifts, but not very effec-
tively ^ No provision was made for gener-
ating 850 Her u shift tones for VHF and
MARS work on iransmJI.

The Interlace 1l4 I'm happy to sayr has

addressed many of these problems and
conquered most of them. The unit has
been completely redesigned so that It
now makes full use of both the mark and
space signals rather than relying on sin-
gle-1 one detect ion.

Perhaps one of the nicest features is
the new tuning-indicator system. It still
uses an LED bar graph, but much in the
tradition of the old "magic eye" lubes ol
days gone by I ve used a tuning scope lor
RTTY and found it to be a nice luxury, but
far Irom a necessity. With the dual -bar
system used in the Kantronics Interface II,
I found that tuning was |ust as easy and
accurate as using a scope. Scope outputs
are available if you still want to hook up
that old tuning indicator

The next area that t found impressive
was the switch-selectable shift options.
Most amateur wor* tafces place at 170-
Hertz shift, but a I most none of the com-
mercial traffic uses this shift. Units such
as the AEA CP 1 allow for a variable-shift
option. My experience, though, is thai this

WHAT DO YOU THINK?

Have you rsoenity purchased anew product thai hJU i 'CL+>n renewed in 7.37 IF
youhavw, write and tetl us what you think about It, 73wiJI publish your comments
so you can share ihem with other hams, as pari ol our continuing effort to bring
you rh" boat in new product information and reviews Send your thoughts to
Review Editor.. ?3 Amateur Radio's Technical Journal, Peterborough NH 03456

is still not as convenient or accurate as
having the 425* and 850- Hertz shift op-
tions swnch-selectabfe I'm still an old
SWL at heart and enjoy tuning the press
and weather transmissions. The Kantron
les il is the first unit J have used that han-
dles the commercial shifts well,

Kantronics did use one cost-saving
technique lor wtder shifts. The same
TiOO-Hertz or so bandpass filter is used
lor both 450- and SSOHertz modes rather
than providing, say, a 560-Hertz tiller for
the 450-Hertz mode. This is a noticeable
omission, but only slightly hampers oper-
ation at the intermediate shift.

Another nice feature is that you can
hook up two different stations to I he inter-
face and select the one you wanl by
means of a front-panel switch, This is par-
ticularly handy if you operate both an HF
and VHF station using the same computer
equipment.

The final new addition is an FMJAM
switch. Those terms are a little mislead-
ing. Under normal condi lions I he TU oper-
ates in the FM mode. A small amount of
audio is amplified so [hat it brings an op
amp in the unit into hard limiting. This ef-
fectively turns over control for the signal
ievef to the TU Under adverse band condi-
tions fhis can create a problem. In the AM
mode, the hard limiter is bypassed. More
audio is required to drive the unit, bu I you
can use the audio and rf-gain controls on
your receiver to more effectively control
the signal going to the TU. The advantage
gained can be a large one, but practice
hetps!

I found one major shortcoming in com-
paring the Interface II to the AEA GP-1.
The AEA unit stiJJ seems to perform some*
what better under adverse signal coodt-
lions in the !70>Hertz mode. It also seems
to permit less "garbage" through when
tuning between good signals. So the
choice may come down to how you feel
about the availability of the commercial
shifts and the switch selection between
two stations. All in all, Kantronics has
done an excellent job ol responding to the
suggestions of its customers. Usi price
for the Kantronics Interface II is $269.95, I
recommend It,

For more information, contact Kanfrpn
ics, 1202 & 23rd Street. Lawrence K$
86044; m 3^842-7745,

Jim Grubbs K9EI
Springfield It

/WARDS

SCHOLARSHIP WINNERS

The Foundation for Amateur Radio is
pleased to announce me 1984 winners of
the fifteen scholarships which il ad-
ministers,

John W. Gore Memorial Scholarship—
$900: David J Schmoeker KJ9I, Qcononv

woe Wl.

Richard G> Chichester Memorial Schol-
arship— $900: Paul D. Sargis Ki6U<
Modesto CA.

Edwin S Van Deusen Memorial Schol-
arship— $350: Timothy Wettach N2TW.
Webster NY.

QCWA Silent Key Memorial Scholar-
ships— $500 each Bruce A, Wade N9UR,

Glendale Wl; Ian R McNichoil KA9KOW

La Habra CA. Scott Smith KA2EMO.
Mai one NY.

Radio Club ot America Scholarship —
£500: Doyle B Johnson KF6BD, Pleasant

Hill CA.

Edmund B. Redrngton Memorial Schol
arship — $500. David Swiatlowskl
KA2KLMHCamllluaNY

Young Ladies" Radio League Scholar-
ship— $500; Diane E. Wlllemin NflCAY,
ElyrJaOH.

Amateur Radio News Service Scholar-
ship— $500: Marc G Vernon K19V. Hins-
dafe IL

Columbia (MD) Amateur Radio Associa-
tion Scholarship— S65G: Enc J, Smith
KA3KJO. Silver Spring MD.

Baltimore (MO) Amateur Radio Club

Scholarship— 1500: Richard A. White, Jr
KA3T, Ml. Airy MD.

Dade Radio Club Tropical Hamboree
Scholarships — $500 each: Wayne F.
Poole KC4XL, Surfside Ft; Craig F.
Rodgers WA4C. Boca Raton FL

Lewis G. Wilkinson Memorial Scholar-
ship—$500: David Chenei KA2PNR, Bronx
NY

These scholarships were open to all
radio amateurs meeting the qualifications
and residence requirements of the vari-
ous sponsors The Foundation is a non-
profit organization representing litty
clubs m Maryland, the District of Coium
bia, and northern Virginia. H is devoted ex-
clusively lo Ihe scientific, literary, and
educational pursuits that advance ama-
teur radio. Information regarding the 1935
awards will appear in the spring In 73

VFN BOTH

A certificate is being offered by the Vir-
ginia Fone Net in commemoration of 50
years of continuous traffic-net operation
on (he 75-meier band, handling traffic Into,
through, and out of the state of Virgin-

ia, The net is non-ef filiated but has a mem-
bership of 150 registered and numbered
licensed amateurs- The VFN holds 2 con-
ventions per year at various places in Vir-
ginia and all amateurs are welcomed
Membership information may be obtained
from any net control or will be furnished
with your certificate, if requested

To obtain this handsome multicolored
certificate, an applicant must make 2- way
Contact with 25 or more VFN members on
any band except during net operation Net
time is daily on 3.947 MHz at 1600 and
1930 EST.

Send your log of information including
the cell of the station worked and the
name and VFN number of the station
worked to: Bill Redmond K4IEC, 917 Rock-
spring Drive, Winston Salem NC 27105.
Include a summary log. Contacts will be
verified from your list. Include £1,00 for
handling and a #10 SASE, or $2.00 for a
"flat pack" envelope. All certificates will
be serial numbered and will be hand-let-
tered with the recipients name and call.
Contacts and requests must be made be
tween September 30, 1984, and June 30,
1985

73 Magazine * November, 1984 81

W2NSD/1

NEVER SAY DIE

editorial t>y Wayne Green

from page 4

on 220 MHz and see if it would
worfc here, They were absolutely
disgusted when the ARRL fought
them and amateurs were mas-
sively against even a no-code
experiment.

I would not look for much in
the way of sympathy or help
from the FCC with regard to
fighting off commercial de-
mands for amateur frequencies.
The hobby is no longer seen as a
service, but more as entertain-
ment for a very few technical
nuts which is taking up some
enormously valuable spectrum
space which could be much bet-
ter used,

What Will Go First

The first push is to get the 220-
MHz band, which the FCC had
saved from CB for the nocode
ham experiment. Next look for
six meters to be reallocated to
something more productive for
the country. Then we can expect
to lose most of the microwave
bands which are desperately
needed for business communi-
cations, Remember that com-
muni cat ions are going to be
growing by a factor of about one
million over the next few years.
Some of this will use fiber op-
tics, some cable, but much of it
will go via microwave and satel-
lites, and that means spectrum
sacrifices.

Perhaps if the FCC had been a
bit more forthright and made it

clear to the League directors
that the choice was between no-
code on 220 or losing the band,
the League might not have
pushed so hard to defeat the
Commission. Oh, the Commis-
sion tried to make it clear, within
their legal limits, but the League
was not paying attention.

From the FCC's viewpoint,
amateur radio is an increasing
nuisance. The hobby used to
pride itself on being self-polic-
ing. Now the FCC gets com-
plaints that it isn't monitoring
and poiicmg our bands for us. It
sees a bunch of increasingly re-
tired, lazy old men sitting around
helplessly wringing their hands
and bitching when other hams
jam their nets and repeaters, but
making no real effort them-
selves to solve their problems.

The FCC sees today the rem-
nants of what was once a feisty
service, one which was respon-
sible a generation or two ago for
the development of virtually ev-
ery breakthrough in communica-
tions—one which greatly helped
the country win WWII by provid-
ing desperately needed techni-
cally-oriented youngsters-
back when the average age of
hams was nearer 30 than 60.

FEW A Replaces the FCC

This year the FCC even got
out of the emergency communi-
cations business by turning it
over to FEMA, the Federal Emer-
gency Management Authority.
FEMA has almost no connec-

tion with amateurs, so we're los-
ing one of the last stronghold
excuses for the hobby: emer-
gency communications. What's
left in the way of rationaliza-
tions for amateurs having the
use of billions of dollars worth
of spectrum?

Amateur radio exists at the
whim of the FCC, so why are we
kicking the Commissioners in
the face when they try to help
us? Perhaps it is a death wish by
the old-timers. Did one single
amateur who fought the no-
code proposition think in terms
of what was good for amateur
radio and for our country? Or
were they thinking only of the
misery they had In learning the
code and which should there-
fore be shared by all newcomers
as a rite of passage? Never mind
that the newcomers aren't com*
ingf but are telling us to shove
amateur radio and Morse code
up our antique antennas.

Sure. I know Pm a pariah to
many hams because I stand up
and tell it like I see it. That's nev-
er been popular, so I shouldn't
mind when ham popularity polls
put me on a level with Nixon,
Watt, or Oswald, From my view-
point* I go to great lengths to do
my homework before I write. My
opinions are solidly based on
facts. No, the attacks are usual-
ly personal, attacking me, not
what Pve written. Well, how else
can someone fight where the
facts are against them?

What Can Be Done?

With four more years of
Reagan Commissioners, if ama-
teur radio were put on the stock
market, I don't think our stock
would sell. What an incredible
pity, for here we are at the right
time in history to provide des-
perately needed services to our
country— and to the world. The

whole world is going high-tech
and here we are with one of the
best training grounds for young-
sters to steer them into high-
tech careers— and we aren't just
not doing it, no, we're doing ev-
erything we can to prevent it.

With communications about
to explode, amateur radio has
the opportunity as never before
to invent and pioneer new com-
munications technologies. Sad-
ly, the hams we need to do this
were shut out of the hobby, so
we donTi have Tem available.
Luckily for the world, though not
for us, Japan does have the
needed technicians and engi-
neers. They came into high-tech
through Japan's no-code ham li-
cense. So we're going to have to
continue to byy Japanese ham
gear, two-way equipment, tele-
phones, and so on. We no longer
have the technical people to
keep up with their creative de-
signing. Soon we may not even
have enough technicians to ser-
vice the satellite, microwave,
and fiber-optic communications
equipment which is pouring into
the country.

If you know of any approach
which will convince youngsters
that they should learn the code,
let me know. I'm ready to try and
get ham clubs started in every
high school in America, but it is
a complete waste of time even
trying this without some con-
vincing explanation for the
code.

No, they won't buy that crap
about Morse code getting
through when all else fails. Nor
will they buy it being less expen-
sive than phone. Heck, you donl
believe that old bunk any more
than I do— and this in my 46th
year in amateur radio. If you can
give me one convincing reason
for the code, I'll be able to get
started.

FUN!

John Edwards KI2U

PO Box 73

Middle Village NY 11379

CONTESTS

ill be honesl. I've never been a big corv
tesi fan. Oh, once or twice In my hamming
career I've seated myself behind a micro
phone, inteni on winning one competition
or another. Unfortunately. IVe neve? man-
aged to oo better than to win first place in

Ihe 1977 Manitoba QSO Parly. Of course. I
was Ihe only New York stairon to par-
ticipate In ihe Manitoba QSO Party that
year, so I'm not quite sure how valuable
that particular victory was.

I think T can attribute my lack of contest-
ing enthusiasm to three factors; no anten-
na, no linear amplifier, and greed. Given
enough money. I could easily solve the
antenna and amp problems. The greed fac-
tor, however, is a bit trickier. Vou see* my
natural avarice tends to keep me from en-

tering contests that only offer fragments ol
sheepskin as prizes A trip around ihe
world? A 1985 Corvette? Sure- A certificate?
Forget (L

Of course, the widespread cheating that
goes on also lums me off. Just who regu-
lates what goes on during these contests,
anyway? Faulty IDing, Ihe disregard of con-
ies! exchange rules, enaggerated signal
reports, and jusl plain crummy operating
practices are commonplace. Perhaps we
should recruit a cadre of contest referees-
hams who would be willing lo tune around
the bands and snitch on ihese creeps and
cheats. Maybe then I'll be able to take con-
tests seriously.

Anyway, for whatever it's worth, here are
this month's quizzes. I feet obliged to do a
column on contest I ng now and then, but ■
don't much enjoy the task.

ELEMENT 1
MULTIPLE CHOICE

1) The very first ARRL Sweepstakes was
held in:

1)1964
2} 1917
3)1930
4)1964

2) The very first ARRL Field Day was held in:
1)1933

2)1962

3) 1957
4)1929

3) Which of the following magazmestorgan-
zations has never sponsored a 1 60-meter
contest?

1)ARRL

2) 73 Maga&ne

3) CQ Magazine

4) Quarter Century Wireless Association

82 73 Magazine • November, 1984

4) During its heyday in the mid- 1970s, ap-
proximately how many hams each year
sent CW and Phone ARRL Sweepstakes
logs to the League's headquarters?

1)500
2)1000
3(2500
4r 10,000

5) Who is 73 Magazine's contest editor? (No
fair peeking.)

1) Robert Baker WB2GFE

2) Robert Bwirsky AF2M
3} Marc Leave y WA3AJR
4) Chod Harris VP2ML

ELEMENT 2

SCRAMBLED WORDS

Unscramble these contest-related terms:
netcots ogi pude

plitumlire xov retcmopu

cocik efcy efefoc

nana net

ELEMENT 3

TRUE-FALSE

1) In 1968, a Technician-
Glass ham won the ARRL
DX Contest

2) The ARRL once spon-
sored a contest that ran
for eight months

3) The Helvetia Contest,
held each April, is spon-
sored by a Swedish ham
society.

True False

4) The ARRL once spon-
sored a Cfossbanrj Get-
Acquainted Party to "pro-
mote fraternal ism" be-
tween 15- and 20-meter

operators.

5) Most coot ester* us* ft
"check sheet" to keep
track of countries and/or
states that still must be

worked.

©J The first ARRL VHF

Sweepstakes was held in

1947.

7} The First ARRL 10-Meter

Contest was held in 1962.

8) The first ARRL 1 1-Meter

Contest was held In 1959.

9) The first 73 Magazine

75-Meter World SSB

Championship was held

in 1970. .

10) The winning operator in

the first ARRL sweep-
stakes worked 20 stations

in 12 sections.

ELEMENT 4
MATCHING

Match the contests In Column A with the
months in Column B.

Column A Column B

1) County Hunters SSB A) January
Contest

2) ARRL VHF QSO Party B> February

3) ARRL Field Day C> March

4) AS International DJ April
SSTV DX Contest

5) ARRL UHF Contest

QMay

8) ARRL 10-Meter

F) June

Contest

7} ARRL Sweepstakes

G) July

Si Washington State

H^ August

QSO Party

9) 73 40-Metef World

1) September

SSB Championship

10} ARRL DX (Phonei

J) October

11) Dutch PACC Contest

KJ November

U December

THE ANSWERS

Element 7;

t— 3 In January,

2—1 In June.

3—4 Not yet, anyway.

4—3 Those were the days.

5—1 The one and only

EtomentZ

(Reading from left to right): contest, log,
dupe; multiplier, vo*. computer; clock,
key. coffee; antenna.

Element 3:

1— False Even 1968 s sunspots weren't
able to provide thai much
help.

2— True The 1946 VHF Marathon.

3— False I Is a Swiss contest.

4— False It was between 40- and 60-me-
ter operators

5— False To keep track of stations al-
ready worked to prevent dupli-
cate contacts.

6— True To the distress of VHF opera^
tors everywhere.

7— False Ten-meter operators had to
wait until 1373 for their feel-
ings of distress.
8— False The ARRL never held such a
contest. Maybe it they had, we
would still have the hand.
9— False In 1982.

10— False He managed a not-so-siagger-
ing 153 stations m 43 sec-
tions.
Element 4:

1— Dp 2— E, 3— F, 4— G, 5— Ht 6— L, 7— K.,
A— lf9— A, 10— C. 11— B.

SCORING

Element 7;

Rve points for each correct answer.
Element £.'

Two and one-half points for each word cor-
rectly unscrambled.
Element 1

Two and one-half points for each correct
answer.
Element 4:
Two points for each correct match.

How did you do?

i-20 points— Transmitting into a
dummy load
21-40 points— Your elements are

bent
41-60 points — A respectable perfor-
mance
81-80 points— Almost a clean
sweep
81-100+ points— No contest?

CONTESTS

Robert Baker WB2QFE
15 Windsor Dr.
AtcoNJ08004

DARC CORONA 10-METER

RTTY CONTEST

1100 to 1700 GMT November 3

This is the last of tour tests during the
year sponsored by the DARC eV to pro-
mote RTTY activity on the 10-meter band.
Use the recommended portions of the
10-meter bend. Each station can be con-

tacted only once. Operating classes In-
clude single/multi-operator and SWL
printer.

EXCHANGE:
RETT, QSO number, name, and US state.

SCORING:
Each completed two* way RTTY QSO is

worth 1 point. Multipliers include the WA£
and DXCC lists, each US state, and each
district In VE/VO, and VK The tinaJ score
is the total QSO points times the total
multiplier.

AWARDS:

Appropriate awards lo the leading sta-
tions In each classification, assuming
reasonable scores.

ENTRIES:

Logs must contain name, call, and full
address of part icl pant. Also show class,
time in GMT, exchange, and final score.
SWLs apply the rules accordingly. Logs
must be received within 30 days after the
test. Send all entries to Klaus K. Zielski
DF7FB, PO Box 1147, D-6455 Ertensee,
West Germany.

ARRL SWEEPSTAKES

Starts: 2100 GMT November 3

Ends: 0300 GMT November 4

PHONE

Starts: 2100 GMT November 1?

Ends: 0300 GMT November 16

Note that these rules were taken from
last year's contest. This year's rules were
not received from the ARAL In time to
make the printing deadline. Check QST tor
any lasi-mlnute changes!

US and Canadian stations work other
US and Canadian stations using l.ft-
through 2ft-MHz bands, excluding 10 MHz.
Operate no more than 24 of the 30 hours
with on/off times noted clearly in your log.
Listening time counts as operating time.
Operating categories include single oper-

CALENDAR

Nov 3
Nov 3*4
Nov 10-11
Nov 10-11
Nov f 0*12
Nov 11
Nov 17-18
Nov 24-25
Dec 1-2
Dec 8—9
0eo26-Jan1
Dec 30
J«n 12
Jan 12-13
Jan 13
Jan 19-20
Jan 26
Jan 27
Feb 23

DARC Corona 10- Meter RTTY Contest #4

ARRL Sweepstakes— CW

Delaware QSO Party

European DX Contest— RTTY

Montana QSO Party

International OK DX Contest

ARRL Sweepstakes— Phone

CO Worldwide DX— CW

ARRL 160-Meter Contest

ARRL 1 0- Meter Contest

ORP Winter Sports— CW

Canada Contest

73 40-Meter World SSB Championship

Hunting Lions In Tne Air Contest

73 75-Meter World SSB Championship

73 160- Meier World SSB Championship

73 15 Meter World SSB Championship

72 20- Meter World SSB Championship

73 RTTY World Championship Contest

FEED-LINE

BUl-iF TIN OF TH£ CAjhTGN AMA H.ijw RJtDIO CLUB

NEWSLETTER OF THE MONTH

One of ham radio's deep mysteries revealed itself to me the other day, I was sit
ting at my desk with hundreds of newsletters— most of them terminally dull —
slacked around me. reading Canton Amateur Radio Club's FEEDLfNE, There it
was. a great truth, in a report on parade communications: " . . ,a big thanks to each
of you."

So what's the mystery? Just this: A newletter is as the club does. For each boring
newsletter, there must be an equally boring club. In the Canton ARC, everyone par-
ticipates? President Scott Duncan KKBO must be a really amazing fellow And Edi-
tor Bill Parks K0JZN must have a tough time keeping up with all of the activity, yet
he handles it wi th a f lair for detai L Con gra t u la t ions to Scott , Bill . and every member
of the Canton ARC— you're doing one heck of a job!

To enter your club"s newsletter In T&s Newsletter of the Month Contest, send it
to 73, Pine Street, Peterborough NH 03458h Attn: Newsletter of the Month.

73 Magazine • November, 1984 83

at Or and multi-operator with a Single
transmitter.

No crossmode contacts are allowed
and each station can only oe worked
Once, regardless of band, A transmitter
used to contact one or more stations may
not subsequently be used under any other
call during the contest period (with the e*
caption of family stations where more
than one callsign is assigned by
FCQDOQ. One operator may not use
more than one caiisfegn from any given lo
cation during trie contest period. The use
Of two or more transmitters simultaneous
ly Is not allowed.

EXCHANGE:

Consecutive serial number, precedence
{A if you run 150 Woulpul or less. 8 it more
than 150 W). your callsign. check (last two
digits of the year you were fur si licensed),
•nd your ARRL section.

FREQUENCIES:

CW-1BO0-1810. 3550-3650. 7050-
7100. 14050-14100. 21090-21 10D, 28050-

28100. Novice— 3710. 7110, 2111ft 28110.
Phone- 1B55-1865, 3850-3950, 7200-
7250. 14250-14300, 21300-21400,
26550-28650.

SCORING:

Count 2 points for each completed
2- way QSO. Multipliers are each ARRL
section plus VESATfl (74 max). KP4,
KV4/KP2, and KG4 stations are in the
West Indies section, while KH6 and other
US possessions In the Pacific count as
the Pacific seel ion Final score is QSO
points times the number of ARRL sec-
lions pus VEa/WlJ.

AWARDS:

Certificates to the top singte-operatur
CW and phone scorers in both the A and B
categories in each ARRL section, and the
top mutti-operator entry m each ARRL
division,

ENTRIES.

Contest forms (log sheets, summary
sheet, dupe sheet) are available from
ARRL headquarters for an SASE. Official
forms are recommended. Any entry claim-
ing more than 200 OSOs must submit du-
plicate checking sheets Incomplete or
late entries will be class died as check
fogs. Logs should include date. OSO time,
exchange sent /received, band, and mode
Postmark your entry for either mode fry
December 21. Send it to ARRL 225 Main
Street, Newington CTOCltl.

Each entrant agrees to be bound by the
provisions as well as the intent of the offi-
cial ARRL rules, Ihe regulations of his li-
censing authority, and the decisions oi
the ARRL Awards Committee- Usual dis-
qualification rules apply.

DELAWARE QSO PARTY
Starts: 1700 GMT November 10

Ends: 2300 GMT November 11

Sponsored by the Delaware ARC. Sta-

tions may be worked once per band and
mode For QSO and multiplier credits.

EXCHANGE:

QSO number. RSfT). and Dataware
county, ARRL section, or country.

FREQUENCIES:

CW— 1805, 3570. 7070, 14070, 21070.
28070. SSB-1815T 3975. 7275, 14325.
21425, 28S50. Novice^37lOT 7120. 21120.
28120,

SCORING:

Delaware stations score 1 poinl per
QSO, Multiply total by the number of
ARRL sections and OX countries worked.
Others score 5 points per Delaware sta-
tion worked. Multiply total by the number
of Delaware counties worked on each
band and each mode (maximum of 36 mul-
tipliers possibte).

ENTRIES AND AWARDS.

Appropriate awards writ be given to the
top scorers- In addition, a certificate to ail
stations working all three Delaware coun-
ties. 11 you work all three counties and
want the WD EL Award, send two 20-cent
stamps and an address label. Mail logs by
December 17 to: Charlie Sculley AE3H.
103 E. Van Buren Avenue, New Castle DE
19720, Send an SASE lor a copy of the
results.

EUROPEAN DX CONTEST- RTTY

Starts: 0000 GMT November 10

Ends: 2400 GMT November 11

Sponsored by the Deutsche* Amateur
Radio Club (DARQ. Only 36 hours of oper-
ation out of the 4S-hour period are permit-
ted for single-operator stations. The 12
hours of nonopefatton may be taken in not
more than three periods at any lime dur-
ing the contest. Operating classes in-
clude: single operator allband and multi-
operator single transmitter. Multi-opera-
tor single-transmitter stations are only
allowed to change bands one lime within
a 15-minule period, except for making a
new muKlpiier, Use all amateur bands
Irom 3,5 through 28 MHz, A corneal QSO
can be established between all conti-
nents and also one's own continent. How-
ever, OSOs as well as QIC iraffic wllh
one's own country is noi allowed* Each
station cart be worked only once per band.

EXCHANGE:

Exchange the usual six-digit number
consisting of RST and progressive QSO
number starting with 0O1.

SCORING:

Each QSO counts 1 point Each OTC
(given or received) counts 1 point. Mulli*
pliers will be counted according to the
European and ARRL countries lists. The
multiplier on 3.5 MHz may be multiplied by
4, on 7 MHz by 31 and on 14 through 28
MHz by 2, However, contacts within the
same continent only count as a multiplier
of one per band (including B0 and 40 me-
ter s^. The final score is t he sum of QSO
and QTC points, times the total multiplier.

MULTI-BAND SLOPERS'

ALSO ftaPOLES A UHTTED-SPtCE ANTEMMAS

OTC TRAFFIC:

Additional poini credit can be realized
by making use of the QTC traffic feature.
A QTC is a report of a confirmed QSO that
has taken place earlier in the contest,
which you send to another station. The
general Idea being that after a number of
stations have been worked, a list of these
stations can be reported back during a
QSO with another station. An additional
1 -point credit can be claimed tor each sta-
tion reported.

A QTC contains the time, call, and QSO
number of the station being reported, eg.,
130O/DA1AW134. This means that at 1300
GMT you worked DA1AA and received
number 134, A QSO can be reported only
once and not back to the originating sta-
tion. A maximum of 10 QTCs per station is
permitted. vou may work the same station
several limes to complete this quota, bul
only the original contact has QSO point
value. Keep a uniform list of QTCs sent
QTC 3/7 indicates that this is the 3rd
series of QTCs sent and that 7 OSOs are
reported.

AWARDS

Certificates to the highest scorer in
each classification in each country, rea-
sonable score provided. Continental lead-
ers wilt be honored with plaques. Certifi-
cates will also be given to stations with at
least half the score of the continental
leader or with at least 250,000 points. The
minimum requirements for a certificate or
a trophy are 100 QSOs or 10,000 points.

ENTRIES:

Violation of the rules, unsportsmanlike
conduct, or taking credit for excessive du-
plicate contacts will be deemed sufficient
cause for disqualification. The decisions
of the Contest Committee are ftnaL It is
suggested that contestants use the log
sheets of the OARC or equivalent. Send a
targe SASE to get loos and summary
sheets (40 QSOs or QTCs per sheet)
SWLs apply the rules accordingly, Entries
should be sent no tater than December 15
to: DARC DX Awards, PQ Box 1328. 0*895
Kaufbsuren, West Germany.

EUROPEAN COUNTRY UST:

C31, CT1, CT2, DL, DM, EA, EAS. Ei, F.
PC. Gf GC Guar. GC Jer, GDt Gt, GM. GM
Shetland. GW. ha, HB9P HB». HV. \, IS, TT.
JW Bear, JW. JX, LA IX IZ Ml, OE, OH,
OH«, QJ*. OK. OR GY. OZ. PA, SM. S. SV,
SV Crete. SV Rhodes, SV Athos. TAlf
UAs t, 3, 4, 6, UA2. UB5 UC2. UNI. W5.
UP2. UQ2, UR2, UA Franz Jose* Land, VO,
YU,2A,ZB2.3A14Ui.9H1.

MONTANA QSO PARTY
1700 GMT November 10 to

0400 GMT November 11
1700 GMT November 11 to

0100 GMT November 12

Sponsored by the Yellowstone Radio
Club of Billings, Montana. Work stations
once per band and mode with Monianato-
Montana QSOs allowed. Work portables
and mobiles as they change counties. No
repeater OSOs

Cau h»«d - Jkw pc

-Hanf mm
io- until*

| 4 BAND ELOPER

3 ■■

tilLVi *SI£M1!

U 40 30
1*0 BU *0V

60 it

kmg

1 u jp?

t 43 •

i M -

1 HO tftAf OII'Ol E >60 flD J0M 113 II liHHj } H6?tr

2 ■■ ■■ IQ 4QM BMl ■■ I 44

[2 *' BHOAO-DAr, iL£ - M.4CM « la >30ti " t 4fl -

W9INN ANTENNAS *i*|W4tw

BOX 393-S Ml. PftOSPECT. II 600 S6

84 73 Magazine • November, 1984

7 MILLION TUBES

FREE CATALOG

Includes ait Current Obsolete, An
bque. Hard To Find fleceiviruj.
Broadcast. Industrial. Radio/TV
types LOWEST PACES, Major
Brands. In Stock.
UNITY Electronics Oepl.S
P.O. Box 213. Elizabeth, NJ 07206

EXCHANGE:

RSfT). serial number, and state, coun
try, or Montana county.

FREQUENCIES:

Phone- 1835. 3905. 7285. 14285. 21305,
28585. CW— ieiQ, 3540, 7035, 14035,
21035. 26035

SCORING:

Count one point tor phone QSOs and
two points tor CW QSOs. Montana sta-
lions multiply total QSO points by number
of states, countries, Canadian provinces,
and Montana counties. Others multiply
total QSO points by number of Montana
counties worked (58 max.).

ENTRIES:

Mall logs by December 15 to Yellow^
stone Radio Club. 2625 Burlington. Bil
tings MT 5910Z

INTERNATIONAL OK

DX CONTEST

Starts: 0000 GMT November 11

Ends: 2400 GMT November 11

Participating stations work stations of
other countries according to trie affinal
DXCC country list. Contacts between sta-
tions ot the same country count only tor
multipliers, but have no QSO point value.
Each station may be worked once on each
band. Use all bands, 160 through 10 me-
ters on phone ot CW. Cross band or cross-
mode contacts are not valid. Operating
categories include: A — single operator all
bands. B— single operator one band, and
G — multi-operator all bands. Any station
operated by a single person obtaining as-
sistance, such as in keeping the Fog, moni-
toring other bands, tuning the transmrttet,
etc is considered a multi-operator sta-
tion. Club stations may work in category C
I multi-op) only.

EXCHANGE:

RSfT) and 2-diglt number indicating the
ITU zone. Please note that ITU zones are
quite different from the ARRL zones! For a

llsl and map oi the ITU zones, send 2 IHCb
lo the entry address listed below.

SCORING:

Each QSO counts one point, or 3 points
rf with an OK station. Final score is QSO
points times ine lotai number of TTU zones
worked on each band

ENTRIES:

A separate log must be ftepf for each
band and must contain the full date. The
log must contain in its heading the cate-
gory ot the station |A, B. C)f name, call-
sign, address, and band's} used. Also
show the total number of contacts, OSO
points, multipliers, and total score. Each
log must be accompanied by the follow-
ing declaration: 'I hereby state that my
station was operated in accordance with
the rules of the contest as well as all regu-
lations established tor amateur radio in
my country, and that my report is correct
and true to Ihe best ot my belief.'

A certificate will be awarded to the too-
scoring operators in each country and
each category. The 100 OK Award may be
issued to stations for contacts with 10Q
OK stations, and an S-6-S Award or en-
dorsements tor individual bands may be
issued to a station for contacts with all
continents, Both awards will be issued
upon a written application in the tog and
no QSLs are required- Logs must be post
marked no later than December 31 and
sent to: The Cent rat Radio Clubr PO Box
69, 113 27 Praha 1, Czechoslovakia.

Chod Harris VP2ML

Box 4881

Santa Rosa CA 95402

DXP EDITION TO KERMADEC

"Ron, Ron, wake up. The storm last
night sank our boat! We're stuck here on
Raoul I standi'1

Ron Wright ZL1AMO pulled himself out
of a deep sleep at 6 am to this unpleasant
news, "Bui then I decided I couldn't do
anything about the boat, so t went over to
the shack and started operating,"

So the unflappable DXpedttioner han-
dled the news that his only means of
transportation back to New Zealand now
tar under 50 feet of shark-infested water.
Operating as ZL8AMO. Ron handed out
mote than 1 0.000 CW contacts from the
Kermadec Island Group, hundreds Of
miles north of his native New Zealand.

The Kermadec story began In 1963,
when Jim Smith VK9NS contacted the
New Zealand Lands and Survey Depart-
ment aboul a joint scientific and amateur-
radio expedition to Raoul Island. Jim, you
will remember, fed the second DXpedition
to Heard Island earlier that year Over the
next few months, details of the DXpedi'
tion began to fall into place, under the
guiding hand Of Dr. J. L Craig of the Zoolo-
gy Department of Auckland <NZ> Univer-
sity

After an exhaustive two-month search
for an appropriate vessel to saii the
lO-member (earn from Auckland to Raoul
island, both the scientific and amateur-
radio teams boarded the ferroconcrete
ship Shiner on March 13. The 18-month-
old ship was registered just before sail
ing; this was to be its first (and lasll) offi-
cial voyage.

The 700 ml Jo sail passed relatively un-
eventfully for Ihe party, with some of Ihe
first-time sailors enjoying the dolphins
cruising in Ihe how wake. The only prob-
lem was lack ol wind, forcing the crew to
motor almost a third of the distance. Five
days later the Shiner dropped anchor near
the loading crane, jusl off the northern-
most (and only permanently -inhabited
island of the Kermadec Islands, Raoul.

The amateurs on ihe ship were tfl con-
tact with tne crane operator the only ama-
teur on Raoui. Warrick ZLBAFH. Soon the
tedious and dangerous task of moving ten
people, scJantKfc gear, radio equipment,
and supplies began, DXpeditioners load-
ed Iheir gear Into an inflatable Zodiac'
and edged closer to the sheer cliffs that
mark the tending zone. Warrick swung his
power crane out over the water and low-
ered the net to the Zodiac, which was bob-
bing up and down In the heavy swells. A
deep sigh of relief came from scientists
and amateurs alike as all equipment safe-
ly made the passage up the cliff.

Then II was time for the members of Ihe
party themselves to land. No safety net for
people: just a ladder swinging on the end
of the long crane. The hams grabbed at
the ladder as H swung past and. hanging
on tight, were whisked up the cliff, trust-
ing to the capable hands of Warrick.

With ihe help of the only motorized vehi-
cles in the Kermadecs. an otd tractor and
an even older truck, the rive-member team
permanently stationed on the island as-
sisted Ihe visitors to their fine accommo-
dations, Soon the hams and scientists Ron Wright ZL1AM0 led four amateurs to the Kermadec Islands off New Zealand this
were comfortably Installed in their guar- past spring.

ters and ready for the serious work of the
trip.

The amateur team of Ron ZL1AMQ,
John ZL7AAS, Roly ZLiBQD, and Duane
W6REC quickly began setting up four
complete stations (including an IGOM
745r ICOM 740, Kenwood T&S3Q, and a
Kenwood TS-43Q), The antenna farm con-
sisted of two tri banders and df poles lor
the lower bands. The 1 60-meter and 80-
meter dipoles were hung at the 100-foot
level between towering Norfolk Pines,
thanks to the climbing ability of scientist
Mark Vette. Another dlpole handled the
40-meter skyhook chores, as well as bach
ing up the higher 80-meter wire.

Not long after arriving on Raoul, Ron
made the first contact as ZL0AMO with
N4VZ on 40 CW. Good radio propagation,
especially on 10 meters, kept the QSO rate
high, Everything was going swimmingly
until late Wednesday night. March 21,
three days after ihe crew landed on Raouh

Cy crone Cyril was headed for the very
exposed Raoul. so the boat captain, John
Taylor, moved the Shiner around to the far
side of the Island and the most sheltered
spot, Boat Cove. The three-man crew on
the ship maintained hourly radio contact
with the rest of the party on the island.
Then, in trie wee hours of the morning, the
cyclone changed direction and high
winds, heavy seas, and driving rain
smashed into Boat Cove,

Soon the Snmef's anchor began to
drag, and then broke. There was nothing
lo prevent the ship from crashing against
the rocks. All three men aboard leaped in
to their inflated life raft, and, thanks lo a
great stroke of good fortune, made it safe-
ly through the violent sea and storm to
shore.

Although no lives were lost and no one
was seriously Injured, the boat was a total
loss. While almost all Ihe radio gear was
high and dry on the fsland, a great deal of
personal equipment and scientific gear
now lay at the bottom of the Pacific, The

two marine biologists rook time out from
chronicling new species of fish to rescue
as much gear as the surf and Sharks al-
lowed. Meanwhile, Bon continued to oper-
ate, piling up more of his 10,000 CW con-
tacts.

With their only means of transportation
now gone, the party began to tune around
the marine bands, looking for a ship going
in the right direction. Fori una! ely, the MV
Vill from Tonga was on its way south to
Auckland and agreed to detour to Raoul to
pick up the stranded party.

The change in plans cut the operating
time short, but who knows when the next
ship might have appeared The group ac-
cepted the truncation of the operation and
the additional S300Q cost and began pack-
ing their gear.

So 8-1/2 days after going on the air from
Raoul, the amateurs closed down. During
thai time they fogged more than 30.000
contacts, knocking Kermadec from 17th
In The DX Bulletins Most -Wanted Ust
right off the chart1 One of the high points
of the DXpedition was getting a call from
BY1PK'

The amateurs left some good antennas
for Warrick, so ZLBAFH could help keep
the demand tor ZLB low. Warrick had a
unique way of repaying this kindness.

The way off of the island was as harrow-
ing as getting on. The gear roiled down ihe
"Flying Fox" tram from the top of the
Island to the small landing platform,
where Warrick stood with his trusty crane.
After the gear was safely stowed aboard
the landing craft, (he radio operators were
treated to a Raoul island farewell: Warrick
swung the hams, clinging desperately to
the ladder, out over the Pacific, and
dropped them straight into the water'
After this ceremonial dunking the now
thoroughly-soaked hams bid good-bye
and boarded the Viti to dry out and steam
toward Auckland and home.

Ron Wright ZL1AMO

What kind of amateur turns back to the
radio after hearing that his chartered ship
just sank? Ron Wright says he enjoys the
more relaxed pace and limited demands
of a DXpedition compared to his daily job
driving a taxicab In downtown Auckland.
Traffic must be pretty bad If losing one's
Ship is more relaxing than driving!

We can thank Ron's grandfather for his
lifelong interest in ham radio. Ron first
began playing with radios in high school.
and In 1953 obtained his first amateur li-
cense as ZL1AMQ, a call he has held for
the last 31 years. During his long amateur
career, Bon has remained very active, es-
pecially in contesting and DX, as well as
in constructing his own gear.

Then In 1978. when his personal DXCC
total stood at aboul 300, Ron decided the
lime had come to "put a little back into
amateur radio in exchange tor all the DX-
peditions I had worked over the years.1'
With the youngest of his 5 children well
grown, Ron took some time off from guid-
ing his taxi to join a contest DXpedition to
Chatham Island, a few hundred miles east
of New Zealand. While operating as
ZL3HIC in the CQWW CW Contest. Ron
me I Chuck ZL1 AD I

Pitcairn Island

Both the successful contest operation
and the friendship with Chuck helped
launch Ron on his DXpedition career.
Their next stop was Pitcairn Island, where
Ron helped meet the demand for CW con-
tacts as VR6HI.

Transport ati on to and from tiny, isolat-
ed Pitcairn is always chancy. Chuck and
Ron caught a freighter bound from the
southern tip of New Zealand and arrived
on PHcalrn a week later. After struggling
up the Jong, steep cliff from the tiny land-
ing area to the town, the two amateurs
erected a Irlband, a dlpole, and a vertical,
and settled down to some serious radio.

Despite the mosqurtos. black flies, and
large, hairy spiders, the hams made plenty
Of Contacts, relieving some of the pres-
sure on resident amateur (and direct de-
scendeni ol the colony's founder) Tom
Christian VR&TC. Now the only question
was how to get off Pitcairn

The few dozen permanent residents of
the island watch carefully for any passing
boats {a major source of income is their
trade with these ships). Whenever a ship
nears Pitcairn, Tom makes contact over
Ihe radio and the islanders launch their
sturdy rowboats with loads of wood carv-
ings and postage stamps

Ron accompanied the islanders on
these I rips, looking for passage off the
island, hopefully toward New Zealand.
The first week went by without success.
Then the second week also passed with-
out any possible arrangements, As the
third week on Pitcairn roiled to an end,
Ron and Chuck were beginning to wonder
if they were ever going to gel back to New
Zealand.

Finally the Yankee Treder a cruise ship
which ruts many of the lesser- visited Pa-
cific islands, hove-to off Pitcairn. Yes, the
captain said, he had room (or exactly two
people, if (hey didn't mind going to Tahiti.
At that point, anywhere but Pitcairn
was fine with Ron and Chuck. Several
days later they tried to explain to the offi-
cials In Tahiti why they had arrived with-
out a visa. Lacking any French, It was
quite some struggle, but finally both DX-
pedition ers were flying back to New Zea-
land, having made more than 33,000 con-
tacts during their three weeks on Pitcairn.
This experience didn't discourage Ron
from continuing his DXpeditiomng career.
Over the next few years, he operated from
both North and South Cook Islands.
Tonga, Western Somoa. the Solomons,
Lord Howe. New Hebrides. Nlue. and
other spots m the region Ron explains
this wanderlust. "With my family grown, I
wanted to see some of the world outside
of New Zealand. With emphasis on 'See-
ing.1 I have an eye problem that Is getting
steadily worse, and I wanted lo hurry up
and see a tew things before 1 couldn t see
them anymore."

73 Magazine • November, 1984 85

Ron finances his own expeditions, sav
mq up money from his taxi driving and
sometimes leasing his cab during his
longer trips Lately he has received some
help from some of the ma|or DX founda-
tions and radio clubs, but most of the
money has come from his own pocket

His understanding wife stays home
f'Shedoesnt like to Iravel much," Ron ex-
plains} and answers the 70.000+ QSla
Ron has received from his DXpeditiontng.
She claims if she wasn't answering the
cards, she'd be working crossword puz-
zles. Answering some of the cards with
the wrong time or local time instead o*
UTC must make crossword puzzles seem
like chl Itfa play.

Operating Tips

Ron's DXpedltion radio Is a Kenwood
TS-030- He uses an Atrtek Research mem
pry keyer and has recently upgraded his
paddle to a Bencher model As with most
CW DXpedrironers, Bon usually operates
about 25 kilohertz up from the bottom of
the band 7025. 14025, etc Again follow
ing standard CW pf actios, he listens "up"
about 2-3 kiloherte.

Ke found the ptteups from Kermadec so
intense that he was unable to maintain an
acceptable QSO rate following normal
procedures, so he resorted to some sub*
terfuge. While continuing to say he was
listening up, he actually made most of his
contacts oefow his transmit frequency. "A
little bit oT deception, perhaps, which pro-
vided more opportunities for stations to
work Kermadec," Hon Justifies this unusu-
al practice.

This illustrates the importance of one
of the most fundamental operating strate-
gies for working D* listen for the station
Ihe DX is working, not |ust to the DX sta-
lion itself Chuck Coleman K6ZUR ex-
plains how he snagged ZLSAMO: "He was
sending listen up' but I didn't hear any of
the stations he was working above his
trans mil frequency, I tuned down below
and heard one of the stations he called. I
quickly zero-beat that siatton, gave a
short call, and he came right back!"

Ron continued to work a few stations
above his transmit frequency just to keep
the pi leu p honest and to separate those
DXers who were listening for the slat ions

he was working from those with their ears
glued to his transmit frequency.

Ron also likes to work down into the
pi leu p to some extent. "The loudest sta-
tions are going to make it sooner or later,
so * took for the weaker stations, the ones
that might only have one chance/' Lets
hope not too many Big Gun DXers tore
their stations apart after being beaten In
the plleup by the peanut whistle down the
street

Another good way not So work Ron is lo
send your call several times. Once fa
enough. If you don't get through, send it
once again. And don t send Rons call; he
knows who he Ifc, and if you're in that pile
up, the odds are you are calling him, (On
[he rare occasions that two DX stations
on opposite sides of the world are trying
to use the same listening frequency, you
might indicate your preference)

Ron also has little patience for the
"dumb" questions which use up oper^
ating time without providing contacts. If
you really want to ask mm his name, loca-
tion, or OSL address, wait until he s back
m Auckland. "Each dumb question uses
up an opportunity for someone else to

work a new one/' Ron explains. By the
way. OSL ail Ron's DXpeditions to his
home call, good In any CailbooM

Keeping a very accurate clock Is anoth-
er hint toward getting, a QSL card from one
of Ron' s DXpeditions To save on log pa-
per, Ron records contacts 5-10 across on
his specially designed log. He notes the
times for each row of contacts. In this way
he fits as many as 400 contacts on a sin-
gle fog sheet. Obviously, Jf the time on
your QSL card is wrong by even a few min-
utes, your call wi.lt be very difficult io find
in that solid mass of stations

Where will Ron be oft to next? Well
have to keep our ears peeled, check the
weekly OX bulletins and the local DX re-
peater, and practice listening to both the
DX station and the station he Is working,
so we'll be ready tor ZLtAMQ's next CW
DXpeditlon .

Special t hanks to ZL18QO, the Northern
California DX Foundation, and of course
Ron Wrigh! ZU AfYlO for this cotunrn

Listen for your toyai DX editor as
T32AW from Christmas island late Octo-
ber-early November. OSL via KlRH,

LETTERS

DOWN WITH CODE

As a new subscriber to 73, I opened the
magazine <or the first lime and ran right into
your editorial message. It was surprising to
find such an important and relevant mes-
sage in what I thought was going to be only
a technical amateur-radio magazine.

I am writing to you to express in detail my
strong support for the opinions and posi-
tions you put forth In this editorial. My fear
is that negative feedback from some a ma-
teurs concerning the code Issue might spill
over Into the far more important issue you
address— the Importance of amateur radio
as the country's main backup communica-
tion system in the case of any natural or
man-made disaster up to an including nu-
clear war Your concents that amateur ra-
dio in the US may be a dying hobby, attract-
ing few younger members, with declining
strength as a market for new products or
as a source of high-tech training are in my
opinion true and very relevant. The current
code requirements may be contributing in
one way or another to all those conditions
and to the detriment of the hobby; I join you
in thinking that it is. Qui the Old-timers are
never going to change, and the prob+ems
may be eliminated by the upcoming cornput
erization of code message transmission
and reception. As you point out in various
articles In your magazine with the assis-
tance of a $350 computer and the righl soft-
ware, any licensed amateur operator can
send and receive messages In code at
speeds up to and exceeding 2QQ0 words per
minute without any personal knowledge of
Hie code. That fad will soon allow most
amateur operators to send and receive
messages at a rate well beyond anyone's
ability to copy manually in an environment
where it Is no longer necessary to know any
code to copy (even If you do you won't be
able to use that knowledge in normal future
QSO situations involving routine hlgtv
speed computer assisied code transmit)*
slons}, II may become even more obvious
that the current code requirement Is a non-

productive carry-over from the past,
possibly harming the hobby. Knowledge of
the code Is useless in Ihe current and ever
changing nature of the hobby.

Fred K Martin
Santa Clara CA

F red, 1 here are a lot of active hams using
code— because it is tun to use. I'm not
even remotely against the code — as a tun
mode of communications. My approach r$
purely pragmatic: We need more hams,
young hams, desperately. Japan has prov
en beyond any argument that no-code is
the answer to this one with their 7.3 mil-
lion hams, so t and the FCC figured fhis
was worth a test on 220 MHzA which is seri-
ously underused and without a new group
fike this coming in writ ttkety be tost. The
ARRL ted the fight opposing it, supported
toy ARRL clubs from coast to coast t sure
hate to see us lose 220 MHz, hut it now
looks We a goner, and that oouid start The
dominoes telling, losing us the rest of the
microwave spectrum And where is com-
munications going? Microwaves and sat-
ellites. Weil, t intend to hang in there and
see it t can be one ot the fast live ama-
teurs, doddering into my ham shack with
my walker, iooking for anyone else left on
20 meters.— Wayne.

Wayne, I really enjoyed your editorials in
the May. June, and July issues of 73, 1 agree
wholeheartedly with you that if most ama-
teurs are against a no-code license, then
these same people should be ret est ed ev-
ery two to five years to make sure they stay
proficient in their code and theory,

I have yet to undersand why American
hams are so uptight about having a no-code
license, There are several countries, among
them Great Br (lain Brazil, Japan, Hong
Kong, and probably others, wfwch have
some sort of no-code license and don't
seem to have any problems with it In fact.
their amateur populations are growing (In
some cases by leaps and bounds! while
ours jus I trudges along. By the way, I got
this information out of the "73 Internal! orv
aJ" seel ion which I really enjoy reading.

It would seem to me that many amateurs
are afraid that having a code-free license
would let a loi of nuts and troublemakers in-
to some parts of the bands Undoubtedly
they don't listen to 2-meter FM repeaters or
to the 40% 7S and 80>me!er bands very
often- If they did they would know that the
nuts and troublemakers are already there
regardless of the code requirement that is
now in effect

in closing, an interesting side note. In
this month's 73 (August, '84) the results of
the recent 'FUNV poll are given, in Element
2T question 16, B7% of the people polled
didn't want the FCC to increase the speeds
on CW exams, In response to question 24,
§4% said they did not want hams to be sui>
retried to periodic retesting. I wonder why?
Could it be that they would not be able to
pass the individual CW or theory tests (or
both) again? They then contradict them-
selves In Element 3 by saying In question 35
that 70% of them can solidly copy CW at
the speed at which they wore licensed.
Then in question 36, 72% said they could
pass ihe theory test for their license class
ff this is true, then why are 94% of them
afraid of periodic retesiing? Sounds very
fishy to me.

Michael Fnedei
Deer Part TX

Michael, a great many amateurs would
much prefer to bar ail further an try into the
hobby in order to keep QRM down on {he
bands. Tests are to keep people out, not
let them in. And. as you suggested, the in-
mates are tn control ot the asylum — Wayne.

I've read 73 for years, whenever I could
find if at the focal newstand, but I've finally
decided to subscribe, rm not now, nor do I
intend to become a ham, but 1 enjoy the arti-
cles and especially your editorials. Since
the last time I tuned in it seems you've been
doing battle with the FCC over the reason 1
refuse to get a license: Morse code.

Requiring someone 10 know Morse Is
somewhat like requiring a thorough know!
edge of ancient Hebrew before being is-
sued a Bible. Why bother to (earn an ob-
scure dialect when more efficient modes of
communication are aval labia? That is non-
sense!

Lest someone think me a refugee from
the CB-trucker mindset, let me explain. I
presently work with computer-generated
video— specifically, the cockpit displays In
the Navy's RA 18A Hornet tighter. This

technology could easily be put to good use
on the amateur bands. Can you imagine
how many youngsters would become inter-
ested if they could plug the Intel evislon into
Dad's moon bouncer for an Interactive
game of real star wars?

You keep working on em* Wayne! I'd be
Extra class tomorrow if it weren't for this
"dsinJtt-darr stuff.

F. C. Glascock
Hanlord CA

Wo. FC. I give up.— Wayne,

I have just learned something about ham
radio, and after reading your May and June
editorials, I am writing to tell you how right
you are. I too am retired and seeking a com-
munications medium to combat Ihe bore-
dom that losing daily com act with others
brings.

I have only been Involved In ham radio
since May, and am frustrated by the d iff!
culty encountered in acquiring information
about the hobby. H's sad to see such a fine
hobby suflenng from a lack of publicity.

1 haw also developed a deep apprecia-
tion for the potential for major service by
hams to our country in times of an
emergency. In Connecticut, Governor
Grasso was so pleased by the service hams
rendered during the terrible b1i2zard of sev-
eral years ago that she signed legislation
enabling ham operators to obtain cailsign
license plaies tor only $5. Most Connecti-
cut hams don't even know about it.

As I began reading your appraisal of the
current status of the hobby, I sensed imme-
diately that you were correct Hare I am, an-
other old duffer joining The ranks instead of
a high-school student. Certainty ham radio
should be made available to them today.
The various Boards of Education must take
action. But, after serving three terms as our
town's First Selectman, I know how very dif-
ficult It is to change ponderous democratic
practices.

I am laboriously learning Morse code As
far as that is concerned, one need only lis-
ten to the bands to know that CW is ob-
solete and should be abandoned by hams
in their licensing procedure,

Don't stop fighting tor change! I already
share your views, and when t get my Gener-
al-class ticket I'll do whatever I can to join
you in the battle. In the meantime, keep
your speed up>

Norman E. Brown
Broofcf ield CT

86 73 Magazine • November. 1984

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73 Magazine • November, 1984 87

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To receive full information from our advertis-

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r. s No,

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Page R. 5, No.

Page R. S No.

127 Advanced Computer Controls . . ,31
■ Amateur Community lions. Etc.

Amateur Electronic Supply 41

Barker & Williamson 66

lb « > *

305 Barry Electronics
T52 Bencher, Inc, . .

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* BreaN Communications . . .
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23 Flesher Corp 49

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308 Flesher Corp 89

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269 GLB Electronics 32

352 Grove Enterprises ... 25

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303 Heath Company 97

3T3 Hewtett Packard 48

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Contest Cookbook

A Guide to Ham Radio
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Living on a Shoestring
The Magic of Ham Radio
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Propagation Wizard's Handbook
SSB. . .The Misunderstood Mode
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Study Guide-Novice Class
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Test Equip, Lib. V2— Audio Tester
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Mailing List 73

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88 73 Magazine * November, 1984

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SEVlEftVILLt TENNESSEE 17182

INTERNATIONAL

Each month, 73 brings you
ham-radio news from around the
world, fn this collection of re-
ports from our foreign corre-
spondents, we present the lat-
est news in DX, contests, and
events, as well as keep you
abreast of the technical
achievements of hams in other
countries.

if you would like to contribute
to your country's column, write
to your country's correspondent
or to 73.- Amateur Radio's
Technical Journal. Pine Street,
Peterborough NH 03458, USA*
Attn: Perry Donham KK2K

AUSTRALIA

J. E. Joyce VK3YJ
44 Wren Street
Attona 3078

Austraffa

ANOTHER NOISE GENERATOR

Australia is about to get the German-
standard stereo system, and It has caused
a targe amount of comment within the am-
ateur fraternity due ro Doth the likelihood
of this system being susceptible to ama-
teur transmissions on boih 2 and 6 meters
and tire tear that there will also be interfer-
ence to the amateur service over a large
area because of the transmission fre-
quencies of this dual -sound system's
audio carriers.

The WIA (Wireless Institute of Austra-
lia} has written to the Minister of Commu-
nications in regard to this matter and a let-
ter has been received back, but the reply is
not very helpful to the amateur commu-
nity.

In essence, the reply says that tn the in-
terests of making available (his advance
fn broadcasting technique to the general
public. Mr. Duffy, Minister of Communica-
tions, is asking members to accept any
small inconvenience to their service
which might occur in some geographical
areas.

This I feel will also {when propagation is
right) Include areas as far away as Japan
and the Pacific Ocean Islands. New Zea-
land, or anywhere that can receive 144-
MHz and 51-MHz signals from Australia,
the reason being that channel 5A1 which is
one of our problem TV channels down
here, operates on 137-144 MHz and is used
by the National Broadcasting Service.

The channel 5A vision carrier rs on
t 38.25 MHz and the sound carrier at pres-
ent Is on 143.75 MHz The second sound
oamer for stereo TV will toe located 5.742
MHz above the vision camef . placing it on-
ly 7.8 kHz below our 2-meter band alloca-
tion. Going by slated deviation figures for
stereo sound in the television industry,
however, a deviation figure of 50 kHz can
be expected, placing it Into the first 100
kHz of the amateur band,

This should make all of those amateurs,

both locally and Internationally, who are
experimenting in the l44.0-ro-144.TMHz
section of the band, less than happy— to
say the least.

Channel O is the other problem area as
It operates on 45-52 MHz and Is operated
by the ABC plus N8S, catering mainly to
eihnic television transmissions.

As you can see by the above, our 2- and
6-meler operalions now have the poteniial
for interference problems even without
this new addition.

The Channel O first sound carrier is on
51.75 MHz, with the second sound carrier
for stereo TV being located around 51 .992
and deviated to {approx,} 55-042- This puts
it nicety into the international 6-meter am-
ateur band.

This tat est intrusion by other services
mto the amateur bands could prove a
greater headache* interference- wise, than
the computer and VCR craze we are pres-
ently going through down here

At the present rate of Introduction Into
this country of rf -susceptible devices for
general public use, we amateurs soon will
need to have either a degree in Interfer-
ence engineering or very, very friendly
neighbors,

VK3-150 YEAR AWARD

It is a long way back from today's cele-
brating of our 150 years of statehood to
those first years of European settlements
in (he southern part of Australia.

The first purchase of {and in what was
to become Victoria (VK3i was made by
John Batman in 1835 when he bought two
million acres of land surrounding what in
those days was known as Port Phillip.
This land was purchased Irom a local ab-
original called Fudgaree for the princely
sum of one dozen blankets, six dozen to-
bacco pipes> 150 figs of tobacco, and two
bottles of rum I

John Batman marked off a site on the
northern shores of Port Phillip Bay for a
town that he was going to call Bat mania.
Luckily for us this town was eventually
called Melbourne, otherwise we down
here would undoubtedly have been called
Batmen or Bat women

To celebrate our 150 years of state-
hood, the WIA will sponsor, from Novem-
ber. 1984, until April, 1965. a Victoria 150
Award Certificate.

Award Rules

Overseas amateurs have only to either
contact or. in the case of SWLs. log one
VK3 station to be eligible for this award-
Mall claims to Victoria 150 Award, Wire-
less Institute of Australia. 412 Brunswick
Street. FUzroy, 3065, Victoria, Australia.
You must Include either a log extract of
the contact or the claimants QSL card,
completed with QSO details lor their VK3
contact, plus £2,00 to cover the award and
postage.

The Victorian State Government is help-
ing to print this Victoria 150 Award and
has permitted amateurs to use a special
"Victoria— Growing Together" logo on
their QSL cards,

AX PREFIX

Out Department of Communications
usually grants the use of the AX prefix for
special events, such as the above. Unfor-
tunately, It has been found that while
most Australian amateurs who use the
special AX prefix do the right thing by fel-

low amateurs, there are always the few
who use these specie I -event callslgns for
DX contacts and fail to honor any QSL ob-
ligations. Trying to remedy this situation,
the WIA has requested thai unless ama-
teurs using special calls are prepared to
OSL on request, they should use their VK
prefix only and leave the AX to those ama-
teurs who will OSL, thereby Improving our
overseas Image regarding the return of
OSL cards.

BRAZIL

Carlos Wanna Cammro PYlCC
Rya A fori so Per?a 49, Apt 70T
20270 Rio de Janeiro. RJ
Brazil

CW AWARDS IN BRAZIL

Brail i tan CW groups are almost sure
that awards are the best way to interest
and develop CW operation amongst radio
amateurs here. Although we have plenty
of contests, it seems mat freedom to oper-
ate at will and depending on available
time and dates according to each one's
peculiarities, awards are much more con-
venient to be worked than contests with
all their plieups and 0RM and limited time
and dates.

So CW groups are doing their best to
present interesting awards to hams.
These are the latest three CW awards, fust
born for our entertainment:

CWSP YL -Award— available to all radio
amateurs and SWLs for proof of two-way
OSOs with five Brazilian YLs. CW mode,
two of them being CWSP members. En-
dorsement seals are available for 10, 20,
or 30 YL stations from anywhere. CW
mode only (YL CWSP members: PYZATU
PY2ADI. PY20HP, and PY2TR are always
present on the BfiYLA net}. Do not send
QSLs, but rather a certified log; fee is 10
IRCs; send lo CWSP Award Manager. PG
Box 15093. Sao Paulo, 01599, SP Brazil,
Valid from May 1, 1984,

Coming from the CWGO group, (solas,
are two new awards: WAPP 2nd Series —
the Worked all PP-pre fixed areas. 2nd
Series award is available to all radio
amateurs and SWLs for proof of two-way
OSOs with 6 different CWGO members
and 5 stations from different PP prefixed
call areas: PP1-, PP^r PP6-, W7-, and I^PS-
OSOs valid from January 1. 1984, on CW
mode only.

OIB CWGO Award— the Diptoma In-
terior Braslleiro (Brazilian Inland
A wardi— available to all radio amateurs
and SWLs for proof of two-way QSOs, only
CW mode, with all nine Inland states (no
ocean-bordered), OSOs valid from Febru-
ary 28. 1984, on. States are: PP2— Galas.
PP8— Amazonas, FX2— Brasilia. Federal
District, PTB— Acre, PT9— Mato G rosso
do Sul, PV— Rorafma, PWB— Rondonla,
PY4 — Mlnas Gerais, and PY9 — Mato
Grossop. PP2 Go las must be represented
by six CWGO Group members. If two more
CWGO members are worked, they can be
used to substitute for two of the inland
states.

Do not send QSLs. Logs, certified by a
radio-amateur association or by two radio
amateurs, are acceptable- The fee for
each CWGO award is 10 IRCs Send to
CWGO Award Manager. PO Box 676. CEP,
74000, Goiania, GO Brazil.

CWGO members list: PP2-AAM, -ABE.
-ABV\ -ACj\ -ACK, -AEP. -AGS, -AHR
-AML. -BD, -B5, -BTt -BW, -CD, -CE,
-CH, -CW. -CY, -CZh -DN. -DO, -DV, -DX,
-EHE. -EM, -FCZ, -FN. -FUT, -GHN,

-INC. -JB, -JO, -JT, -MMOp -Ra -RS.
-SJ, -USt -VR. -WT, -WV\ -XI. -YY. -Zl,
PY3YXZfPP2, PP2CW being the CWGO
station call.

Brazilian CW groups realized thai
amusing-rules awards are the best way to
develop radio amateurs' interest in CW
operations, and so efforts are all towards
this direction.

PPC Picapau Carl oca (Carioca Wood-
peckers GroupK the oldest of CW groups
in Brazil, is now coming to its 20th year
having almost reached Its "20 Awards
Program." a sweeping and amusing pro-
gram to meet all Interests— with some
not-so-dlfflcult and some not-so-easy
awards, and plenty of fun to amuse all and
to enhance CW practice among Brazilian
radio amateurs.

The just-launched PPCMC Members
and Countries Award. Joining DX coun-
tries iARRL hst} and PPC members, with a
special Honor Roil Award when 200 points
are reached (and a basic award at 50
points — at [east 40 DX countries) seems
(0 raise unusual Interest due to the "per-
manent " classification Us! like the DXCC
QSLs are valid from January 1. 1980, so
old-timers can join the fun of new hunting.

The PPCPU Award Is presented to wel-
come new class C PU prefixes- The basic
award is obtained by proof of 9 PU QSOs.
from PU1 to PUS; later endorsements are
for the remaining 18 possible PU calls, ac
cording to suffix letters allocated to each
of 27 Brazilian stales and territories.

The three-class PPC Samba Award
(South American Maritime Borders
Award) is another very amusing game to
he launched pretty soon, with interesting
conditions and rules.

Keep an eye out for Brazilian new
awards! They are fine'

CZECHOSLOVAKIA

Rudolf Karaba (OK3KF0 ARC)
Komenskeno 1477
955 01 Topohany
Ciechosiovakia

CRC. PO Box 68, 113 27 Praha 1.
Czechoslovakia, is offering these awards
for non-European countries:

P-75-P is awarded for contacting or lis-
tening to stations In various ITU zones.
There are 75 zones altogether, and three
sorts of awards are available: 3rd class for
contacts with 50 zones, 2nd class for con-
tacts with 60 zones, and 1st class for con-
tacts with 70 zones

Alt contacts since January 1, 1960. irre-
spective of the class of operating service
or the band used, are valid for the awards.
It is necessary to send the appl ications to-
gether with 10 IRCs and QSL cards to
CRC. A list of zones can be found In the
Caiihook.

$-$-$ is awarded for contacts with one
station on every continent on one mode
Endorsements for separate bands are
available. Contacts after January 1T 1950,
are valid.

It is necessary to send 5 IRCs and OSL
cards to CRC.

More m my next column

AWSAT

At the end of March. QK3DQ from Nizna
nad Oravou In northwestern Slovakia
started using AO-10. Jan is using a
30-Watt SS&/CW transmitter with a
21 -element yagi (F9FT). His receiver has a
BF961 transislor or three SK-97S. and a 2
x 10 element yagl— PA&MS. Both the an

90 73 Magazine • November, 1984

tennas are of vertical polarization. He is
praising a busy operating service that In
his bad OTH is a pleasant change In
VHF/UHF. During the first two weeks of
operating In mode B, he established 272
contacts (115 Of them SSB) with 48 OXCC
countries, By operating SSB he heard
another Czechoslovak station, OK1 VKP.

OK 1 BMW fmaybe also other Czechoslo-
vak stations) received a QSL card from
W5LFL for listening to the signals from
the sky!

RTTY IN CZECHOSLOVAKIA

Nearly 40 stations from Czechoslovakia
are working actively on RTTY, Radio club
OKiKMU is another new station. During 6
months there have been established con-
tacts with more than 25 PXCC countries in
3 shortwave bands. In the 144-MHz band,
they have had contacts with 5 stations
from Czechoslovakia and 4 stations from
West Germany.

FEDERAL REPUBLIC
OF GERMANY

Raff Beyer DJ3NW
Opferkamp 14
3300 Braunschweig
Fed&r&t Republic of Germany

IARU- REGION 1 CONFERENCE

The International Amateur Radio Union,
Region 1, represents 55 national amateur-
radio societies with about 250,000 fi censed
amateur-radio operators. Their last trlan-
nual meeting took place in April, 1984, in
Cefalu. Sicily, Italy, Among the very many
topics discussed, some got my particular
attention.

First, the IARU proposed a new statute
to its members In Regions 1, 2, and 3
which has been accepted in the mean-
time. Now each region will have a chance
to send two representatives to the IARU
Administrative Council. Together with the
regulation that the office of the IARU must
not necessarily be associated with the
ARRL offices In the future, the new stat-
ute offers a chance to assign responsibili-
ties and duties to an internationally more
balanced group than was the case In the
past. However, the ARRL has been elect-
ed again to take care of the 'International
Office" of the IARU.

Second, from time to time small steps
towards a political union of the European
Community (EC) are achieved. The latest
achievement in this respect is an agree-
ment between France and the Federal Re-
public of Germany that motorists need
not slop and identify themselves at the
border between the countries any more if
they have nothing to declare.

It Is only logical that the IARU, Region 13
would formulate similar goals like, for ex-
ample, an International amateur-radio
license. However, It will be difficult to
come to such an agreement within the EC
because of the sometimes very different
national license regulations. I consider it
rather impossible In the foreseeable
future to agree on an international ama-
teur-radio license which Is honored In all
countries of Region 1 because of the
sometimes severe conflicts Involved.

Nevertheless, some days later at the
CEFT Subgroup R21 Conference In Ma-
drid, Spain, an Interesting approach to the
problem was developed. It aims at a multi-
tude Of bilateral agreements which, In
fact, could form a solid basis for a truly in-
ternational amateur-radio license In the
future.

And last, the IARU, Region 1, attempted
to reduce the number of contests on all
Shortwave bands and formulated the fol-
lowing recommendations: Limit all con-
tests to a maximum duration of 24 hours,
assign only one weekend for the phone
and/or CW portion of a contest, merge
smaller contests into larger ones, and
have only one large and one small contest
per month In Region 1,

Furthermore, ft was recommended to
limit contest operation on 80 and 20 me-
ters to the following band segments:
3500-3560 kHz and 14000-14060 kHz for
CW and 3700-3800 kHz and 14125-14300
kHz for phone. I personally would like to
see even tighter restrictions. On an an-
nual basis, I'd like to suggest that only 5%
of the number of weekends (52) times the
available frequency spectrum (300 kHz on
80 meters plus 350 kHz on 20 meters in
Region 1) should be available to contest-
ers — ,05(52 x 650) = 1590 frequency-
hours. It would then be up to the con-
testers how they utilize their available
time. For example, they could run 2-3 full
contests per year the usual way or B-9
contests per year employing only 200 kHz
of the available frequency spectrum on SO
and 20 meters and so on. Wouldn't this
make sense?

The next IARU Region 1 Conference is
scheduled for 19B7 In the Netherlands
Then It will be the time to review the prog-
ress they— and we— have achieved In the
meantime.

GREAT BRITAIN

Jett Maynard G4EJA
10 Church fields
Mdnes WA& 9RP
Cheshire
England

THE UK SCENE

The difficulties of obtaining convic-
tions in cases of illegal use of transmit-
ting equipment In the UK (and Including
the pirating of amateur bands) are eased
somewhat by the provisions of the Tele-
communications Act 1984, which received
the Royal Assent and therefore became
embodied in the law of the Eand in July.

To date It has been necessary for the
police (we do not have an FCC equivalent]
to catch offenders in the act of transmit-
ting In order to be assured of a conviction.
Just as soon as the knock came on the
door, the offender would power down and
so be largely immune from prosecution.
The possession of equipment capable of
transmitting on frequencies for which the
owner was not licensed was not, in itself,
a felony.

The new act conveys wide powers, both
to the police and the newly-formed Radio
investigation Service (which used to be
the Radio Interference Department of Brit-
ish Telecom) , both of whom are given pow-
ers to seize equipment allegedly used for
Illegal transmissions. The courts may
also order forfeiture of equipment without
any criminal proceedings being initiated.

The act also provides new powers for
the Secretary of State to "restrict the sale
and possession of specified wireless te-
legraphy equipment" and to "carry our ap-
proval of equipment and require marking
of apparatus."

The former provision raises the specter
of a ban on 26-MHz linear amplifiers (simi-
lar to that imposed in the US} to prevent
their use as "'burners*' by CR operators In
the 27-MHz band. Such a ban is not likely

to achieve its laudable aims, of course,
since the Illegal users can always find
something else to occupy themselves, but
it does deprive genuine users of the ability
to acquire a particular facility.

The latter provision makes me wonder it
the authorities ever take any notice of
rules and regulations that have been pre-
viously implemented. The liberalization of
British Telecom and relaxation of their
monopoly included the provision that sub-
scribers could, for the first timea buy ex-
tension and other telephone equipment
from high-street stores.

In order to protect BPs network, it was
decided that only equipment marked with
a green dot and the word "approved"
could be connected to a BT-s up plied tale-
phone outlet. Equipment not so approved
must be marked with a red triangle and
the words "not approved/1 So far so good,
but If an article cannot be connected, Is
there any point in allowing it to be sold?

If I take a walk down London's Totten-
ham Court Road— the mecca for hi-fi,
video, and computer enthusiasts — I can
see approved and non-approved equip-
ment side by side In the many shop win-
dows. The n on -approved equipment tends
to have more facilities and be cheaper
than that with the green dot. I do not think
it requires too much guesswork to figure
out which equipment sells the most. One
can envisage a few years hence the ham
shop selling a 440-Watt approved linear
and a 2-kW non-approved one — quite a di-
lemma for the DXer!

Finally, with the Telecommunications
Act 1&84, the police are given some pow-
ers of arrest without a warrant in cases of
Illegal transmitting where a question of
identity arises, I wonder if this could re-
sult in the need for hams to carry some
form of ID card?

The RSGB has launched a monthly cir-
cular called VHF/UHF Newsletter to keep
devotees of the shorter- wavelength bands
fully up to date. Subscription for 1 2 issues
is $6.00 for UK subscribers— $10.00
should be enough for any airmail costs to
be covered. Enquiries to the RSGB at
Alma House, Cranbourne Road, Potters
Bar, Herts EN63JW, England.

This month's column is a little shorter
than usual because I am rather busy with
a new job. This is as General Manager of
the telecommunications branch of a ma-
jor airline. In addition to the thousands of
data terminals worldwide, the UK tele-
phone system, and the airport PMR and
departure control systems, I have discov-
ered I also have responsibility for a major
HF station. That may well provide some
Interesting material for the future. . .

I r ^

I L

■ '

GREECE

Manos Darkadakis SV1IW
Box 23051
Athens 11210
Greece

Since as I'm writing this month's col-
umn we are in the middle of the summer, it
Is very hard to get in touch with most of
my fellow SV DXers, Therefore, I have to
Stop for the time being introducing them,
but for sure I'll come back later when
everybody is back home and accessible.

These past few months we heard a new
repeater that came on the atr from the city
of Kavalla, up In the northeast part of
Greece. This one works on European Re-
peater Channel R7 and looks like it will be
able to cover the northern part of the

Aegean sea and most of the national road
that connects Thessa Ion ica with ail major
cities in northeast Greece up to the border
with Turkey.

There is also another one that is ex-
pected to be installed very soon on the
1 3 land of Kefalonia, but more news on that
when it Is on the air.

I would like to point out that since
Greece is mostly a mountainous country,
we need to have as many repeaters as we
can, not Only to cover the national roads
and to give to amateurs in the whole coun-
try the opportunity to communicate with
each other, but we need the repeaters for
emergency communications— such as
during earthquakes, fires, and so on.

I can assure you that we have plenty of
both, especially during the summer when
we have hundreds of fires In all Greek na-
tional forests. Then repeaters can prove to
be very useful, as they can establ ish com-
munications between city and forest de-
partments with the assistance of radio
amateurs who provide the necessary eyes
for them- Tm sure that every country can
take advantage of radio amateurs and
their knowledge of communications, es-
pecially in times of disaster.

INDIA

Miss fi. Subha
3, Tftlru-VhKa Road
PS No, 725
Madras 600 006
India

DUTY-FREE IMPORTS
FOR INDIAN HAMS

Indian hams have something to rejoice
about— import duty has been completely
waived on amateur equipment. The waiver
covers not only transmitters, receivers,
and transceivers, but also gadgets like
Morse-code readers and aural frequency
readouts.

This move— license-freer duty free im-
port— could conjure up visions of ham
shops full of amateur equipment. There is
a catch to It, however. The user alone is
entitled to Import the equipment, so that
each amateur has to import one piece of
equipment and dealers cannot import for
stock and sale. To be eligible for exemp-
tion from duty, the Importer should obtain
a license from the Wireless Adviser to the
Government of India (counterpart of FCC)
before the equipment is received in India.

Amateurs can join together and import
equipment under a joint bill of lading or
can give a letter of authority to a dealer
who then can import a consolidated ship-
ment as their agent. One dealer, VU2TF,
agent for Yaesu, tried to put together a
group of over 75 for the FT 77 at a discount
of over 20 % over the normal rate. He en-
rolled over 100, but could never quite
make it. Enter the 757GX, and the FT-77
group dwindled to well below 75. Back to
square one!

Now is the time for anyone wishing to
send gifts of new or used equipment to In-
dian amateurs. Here Is the checklist:

• Notify your donee that you propose to
give him equipment as a gift,

• Enclose a catalog page, preferably
showing the price. The amount of the
price is immaterial— he can receive up to
US$870 in a fiscal year (April to March)
and does not have to pay a cent of duty.

• If no price is listed, obtain a quotation
from your local friendly dealer or make a
copy of any classified ad to establish a
price {any price!). If you are offering home-

73 Magazine • November, 1984 91

brew equipment, enclose a declaration
that J t was homemade and that It cos I you
so many dollars

• Walt till the donee confirms that he has
the WPC F I cense for this s pacific piece of
equipment, Only then can he import it
duty-tree.

• Ship It by any mode, surface mail, air
mall, air cargo, or even sea cargo, but not
as passenger baggage. Ham equipment
as baggage ts not eligible for duly-free erv
try,

• Send the trill of lading to the donee by
air malt. If sent by air cargo, GSP to htm
the particulars of the bill of lading or send
him a cable. Demurrage on air cargo is
quite heavy arid could add up to a hundred
dollars in eight weeks,

• Do not ship by air cargo to donees who
are not in the elites of Bombay. Delhi.
Calcutta. Madras, of Bangalore Others
wktf have to make arrangements at one of
the entry points to tile a bill of entry and lo
clear the parcel through customs.

The Indian amateur can import compo-
nents, too. but only as spares for equip-
ment that he imports. Obviously, this bit
has been influenced by commercial inter-
ests— the frome-brewer still has to pay du-
ty if ha wants components. Strange situa
lion, but one teams to take these m one's
stride. The Federation of Amateur Radio
Societies has made representations that
the home- brewers' imports of compo-
nents {not spares) should also be exempt
from duty. Let's keep our fingers crossed!

Here is the full list of equipment and
components that are exempt from import
duly:

Wireless Apparatus and Accessories

1. HF I rans receiver (transceiver) meant for
amateur frequencies) with accessories.

2. VHF trans receiver meant for amateur
frequency! res) with accessories,

3. UHF transreceiver meant for amateur
rrequency(ies) with accessories

4. VHRVHF or VHF/UHF repeater (combi-
nation of transmitter and receiver) with
accessories meant for amateur frequen-
cies.

5. Control unit for the 4 Items above with
accessories.

6. Aural readout til splayed frequency.

7. Aural readout displayed lime.

8. Aerial/antenna for amateur frequencies,

9. Balun transformer,

10. Swr bridge or reflectometer.

11. Digital frequency counter (up to 600
MHiJ with accessories,

1 2. Morse reader.

13. Noise bridge.

14. Microphone (with or without loud-
speaker).

Components

1 Transistors, diodes, integrated clf-
cultsichlps,

2. Thermionic valves or vacuum lubes.

3. Toroidal cores.

4, Quartz crystals.

5, Variable condensers, air-dleiectric
type,

6, Precision capacitors (fixed type),
valuers) between 1 pF and 5000 pF.

I. Relays.

8. Rf cables,

9. Spare nlcad cells or pack as required or
used with Hems 2 and 3 above (in case of
hand-held transceivers).

10. Rotary switches.

II, Keyer paddle.
12. Ferrite beads.

ITALY

Mario Ambrosi 12MQP
Via Stradefia. 73
2W29 hidano
fiaty

18 AND 24 MHZ

II is a few months now that 16 and 24
MHz have been used by Italian hams. Out
there is not too much activity If you open
your rig there you will only find QRM The
reason could be the fact that no Ws or JAs
are allowed there, but maybe there is an-
other reason. The fact that both bands, by
IARU decision, are not used during con-
tests and are not valid foe any award prob-
ably keeps us oft them. The reason for the
IARU decision was justified by the need
(or not having all of ys there together, but
It seems they have obtained the opposite
result: nobody is there. The cost of anterh
nas with practically no return in terms ot
what is wanted by DXers (contests and
awards) is too high. According to old-
timers, this happened also to 21 MHz
years ago, so probably It is not necessary
to worry too much; we're waiting for our
friends from Japan and the States to
come and give some life to Ihe two new
bands,

UHFSHF

Years ago the I2X beacon was installed
In Milan, operating with 40 mW on 10 GMz.
The results have been very good; the bea-
con was well received within a range of
250 kilometers, with mostly late-evening
openings. During the month of July,
IBSNY of the 10-GHz world record will be
back in North Africa trying lo set new rec-
ords, working 24, 10, and 1.2 GHzn and of-
fering the possibility to have a new one to
many Europeans on 144 and 432 from EA9.

DINO ISLAND EXPEDITION

Dlno I stand is located in Calabria very
close to ihe coast. (This answers all those
that have asked for it as. being very small,
it is not on normal maps.) It is very easily
reached with a smalt boat and is populat-

ed only during the summer by tourists liv-
ing in a small village,

The island was activated lor the first
time In June, 19&3, with the call ID8UDB, a
new prefix and a new IOTA number. It was
activated mainly on CW {95% of the total
GSOs} by three operators of INORC (Ital-
ian Naval Old Rhythmers Club) and the DX
Blue Team: I2BVS Enzo. I2DMK Max, and
I2NYN, his son, Marco,

The operation started on June 7 and
ended June 14 with 5600 contacts, most ot
them on 14-MHz CW, as the propagation
was quite poor The antennas used were a
two-element beam for 10, 15, and 20
meters installed on top ot a 10-meter por-
table tower of only S kilos, and a ground
plane lor 80- 10 meters.

The ground plane was not working too
well on 40 meters and a new antenna was
Inst ailed, coupling a 12-meter long wire to
the metal tower The sloper so obtained
was working perfectly, giving satisfaction
m working many USA, J A, and VK stations
on 40 As said above. 20 meters has been
Quite good white IS has been very lousy.
10 meters has been offering short-skip
openings to Europe and some sporadic-E
to South America. OSL cards via 12MQP

0XSG8

If you have the opportunity to work the
above cailsign (it is not yet official as the
station has been working up to now with
the call I2XDP/9X5). you will realize, upon
receiving the OSL card, thai it is not a nor-
mal station. It is the station of the hospital
run by Italian missionaries in Mush a and,
on top of it, it's working with the power of
solar panels that are linked to two bat
teries of 12 V. 66 Amps. The rig is an
FYT-707 and the antenna Is a Selement by
Hy-Gain.

Other solar panels are linked to bat-
teries thet are used to serve all the mis-
sion. Of course the strength of the sun in
Rwanda must be consistent to do such a
beautiful job, but the Black Continent and
Dalian ingenuity can offer you more sur-
prises—like the 5H3KG station (another
well-known call run by another Italian mis

sionaryl that Is powered by the wind. I will
offer you more news on It in a future col-
umn

WORKING THE LOW BANDS

Due to the actual slowdown of suns pot
numbers and thanks to the new life given
to the low bands, a new antenna is becom-
ing popular in Italy. It's the OB24, the
4 -element by Hy-Gain, wilh I wo active ele-
ments on 40 and two on 20. The price Is
quite attractive, being about $180 while
you have to pay more than $650 for a
TK7DXX. So> if you find many more Sta
tions during the next contest season
working on 40 from Italy, you can bet that
many of them are using tt.

Always staying on the tow bands, a
modification to the well-known W3DZZ
has been offered in the July issue of Ihe
Italian amateurs' magazine by I* NOT al-
lowing the popular dipole to work on 160
meters. Two traps have been added with
33 feet of wife. Tne antenna is working
very wetL

The first contact between Italy and Aus-
tralia has been made by I2BBJ and YKGHD
on April 25. The contact was made feeding
the 30^meter tower you can see in (he
photo-

LIBERIA

Brother Donard Stetfes. CS C

EL2AUWB8HFY

Brothers at the Hoty Cross

St. Patrick High School

PO Box 1QQ5

Monrovia

Republic of Liberia

AMATEUR RADIO IN LIBERIA

The Ministry of Post and Telecommuni-
cations called a meeting of all me ama-
teurs In Liberia. It was called in conjunc-

Dino island,

92 73 Magazine ■ November, 1984

The 128BJ end of the VKGHDJtaty contact.

tlon with the Liberia Radio Amateur Asso-
ciation (which did put out an agenda), but
the object of the Ministers interest In the
meeting was not given. The Ministry ex-
pressed a degree of urgency in their no-
tices to the amateurs to attend the meet-
ing and implied that absence without
good reason would not be taken lightly.

The amateurs came into Monrovia by
air, by private automobile, by taxi, and by
whatever mode of travel was available,
and the meeting was the best attended
and the most successful that I have seen
in my three and a half years in Liberia. As
the assembly gathered, there was tension
in the air and everyone walked around
with a feeling of apprehension. As it worked
out, this apprehensive feeling proved to
have been unfounded, however; this meet-
ing was some kind of a first and no one
knew just what to expect.

The Minister— actually the Assistant
Minister in charge of radio opera-
tions— opened the meeting, One could
have heard a pin drop, Sensing the ten-
sion, the Minister did what he could to
make everyone fee! more relaxed and
comfortable. He welcomed those present
and expressed satisfaction at the number
who had responded to his call. A roll call
indicated that upwards of ninety percent
of the amateurs of Liberia were in atten-
dance. Those who were not present were
either out of the country on leave or at
work in a position that did not permit
absence.

The Minister did not keep the group
waiting. He stated simply and briefly that
a problem was developing in Liberia in the
area of third-party traffic and other mark-
edly commercial land therefore Illegal)
communications In the amateur bands.
He said that complaints were coming in
from countries outside. He pointed out
that for many years Liberia has enjoyed an
enviable reputation Jn the world of ama-
teur radio for Its courtesy and its obser-
vance of national and International law,
and he said that the Ministry and the ama-
teur community of Liberia Is very jealous
of this reputation and will preserve It,

He was quick to mention that the prob-
lem is not widespread. The aim of the Min-
istry is to see to It that the problem does
not grow. He asked the cooperation of the
amateurs to eliminate the problem com-
pletely.

I have noted in other columns that I
have sent to 73 that I have been greatly
edified by the caliber of courtesy and the
observance of amateur regulations here
in Liberia. J have a hunch that these few
problem-amateurs are expatriates. If this
Is true, It is unfortunate because the Min-
istry of Post and Telecommunications has
been most generous in licensing people
who are not citizens of the country. As an
instructor in amateur radio and as a mem-
ber of the examination committee, I have
been working rather closely with the Min-
istry and there is not a single instance. In
my experience, in which a foreigner, of
whatever race, has been denied a license
when he has completed the requirements
in code and theory.

This is not true in all countries, I person-
ally was denied a license in another coun-
try where I was working for eight years
simply because 1 was not a native. At least
that is the reason that was given. We, who
are visitors in Liberia, would do well to
cooperate with the Ministry and observe
the law.

The Minister spent the greater part of
the meeting encouraging the amateurs to
be more active, to participate in the local
nets, and to join the Liberia Radio A ma-
teur Association. He suggested that the
amateurs use the facilities of the Associa-
tion to handle QSL cards* going and com-

ing, and to work with the Association in in-
structing and training new amateurs. He
recommended that local areas organize
clubs or associations so as to coordinate
their efforts to manage and develop the
amateur community in Liberia.

In the meantime, the Association is
working on a program for Amateur Radio
Week, it will be held in the latter part of
November or the first part of December,
and while things are In no way finalized, it
is fairly certain that there will be a special
calisign for that period. There will be a
special -event station and there may be
awards. Turn your dial, look for Liberia,
and take full advantage of this opportuni-
ty! There will be publicity. Be on the alert
and don't miss iL

The Association again petitioned the
Ministry for a spot in the broadcast band
to transmit code for practicing beginners.
The proposal was well received and it may
well be that, one of these days, there will
be something to report In this area.

We, the amateurs of Liberia, look for-
ward with confidence and hope. We are
sure that we will continue to grow in
strength and prestige as we hold our
place among the amateurs of the world.

MOZAMBIQUE

Charles E. Martin A84Y
American Embassy Maputo
Department of State
Washington DC 20520

Greetings from Maputo (old name:
Lourenco Marques) by the beautiful In-
dian Ocean. No, fellows I don't have a li-
cense yet. As of this writing, amateur
radio is "suspendedM In the People's Re-
public of Mozambique. I am a foreign ser-
vice officer, and in the diplomatic lexicon
"suspended" is better by far than "prohib-
ited" or "cancelled." If an activity is "sus-
pended " then the authority is stating that
the condition is temporary. I still remain
very optimistic that amateur radio will re-
turn to Mozambique,

Mozambique has a full share of the typi-
cal third-world nation's problems. It is one
of the most miserably poor nations on
Earth. In 1983, 100,000 people starved to
death. (Your tax dollars are supporting the
largest aid program on Earth to get food to
the people here,) Three out of five Mozam-
bicans cannot read or write. Virtually all
the technicians in the country are foreign-
ers from Europe or the communist bioc.

The main reason for the absence of am-
ateur radio is the fact that the country is
undergoing a massive guerrilla insurgen-
cy. This city of 850^000 peopie is virtually
cut off from the outside world as far as
overland travel Is concerned. Add that to
the government's general paranoia and
distrust of foreigners, and it is apparent
that amateur radio is not at ail welcome
under the current security situation.

My wife Yee's (N4GPB) and my chief
concern is food. The currency here is vir-
tually worthless. The official exchange
rate is 40 per US dollar, but the free-
market rate is 1500. The currency cannot
be converted at the official rate. The
stores have no food and the restaurants
serve only a rice-water gruel. When the
road to South Africa Is open, it is a 5-hour
drive to the grocery store. Now that the
road Is closed, we have to get our
foodstuffs shipped in and rely on the
"hard'1 currency shop here In Maputo.

As far as ham radio goes, I am occupy-
ing my time by teaching ham radio to four

other Americans and modifying my gear
to run on 220 V, 50 Hz, My house servant
plugged my 24-hour digital clock into the
220-V current and blew it up. It cost more
than he earn3 in three months. Most Mo-
zambicans earn less than the cost of a
2-meter transceiver in a year.

My house was built before electricity
and the wiring is adequate, but nothing
fancy, I am getting additional outlets and
transformers installed in my radio room.
We get television from ZS and 306 here,
so the city is filled with towers and anten-
nas. I am getting a 60-foot tower installed
and I will hang my tribander on it. I have
been monitoring the bands and have
heard many US stations on 2Qm, but I have
not heard any amateur stations on 30m
here yet

I have been doing preliminary research
into the possibility of running a DXpedi-
tion to some of the offshore islands. The
French have a large embassy here, and I
can easily arrange transport to Europe
and Juan de Nova islands. The western
diplomatic community here Is very close,
and arranging the landing permits and op-
erating permission should present no real
problem.

I will remain In Mozambique for at least
two years, perhaps until 1988. I am hope-
ful that I will receive operating permission
before I depart. Mozambique is a difficult
and uncomfortable place to live, and ama-
teur radio would make It much more pleas-
ant, i am planning to visit several of the
nearby countries during my stay here, and
I plan to operate from several of them.

I have never run a expedition before, so
if any 73 readers could offer assistance in
DXpedttioning, I would be most grateful.
Unfortunately, there is no "handbook.1'

NEW ZEALAND

D. J. (Des) Chapman ZL2VR
459 Kennedy Road
Napier
New Zealand

This month I snail continue the New
Zealand offshore islands' stories with an
excerpt from the Raouf island expedition
story, through the courtesy of the author,
Roly RuncimanZLtBQD, and Break-in, the
NZART Official Journal. As reported in my
July column, the Raoul island DXpedition
took place in the second half of March
this year and was successful from the
radio and scientific points of view, but a
disaster for the owner of the yacht Shiner
used to transport the expedition to the
Kermadec Islands.

Departure: Tuesday t March 13, 1984, at
1 1:30 am M2Tr the group was aboard the
yacht Shiner on their way to one of life's
great adventures. Years of hard work by
Ron ZLlAMO and months of departmen-
tal negotiations by Dr. John Craig, the
leader of the scientific party, had finally
paid off and they were on their way to the
Kermadec Group of Islands, destination
Raoul Island, ETA 5 days.

The Travelling Party. There were ten
persons on board, five in the scientific
party, four In the amateur party, and the
Captain, John Tayior. The scientific party
consisted of Dr. John Craig, expedition
leader, who was to study both the native
Klore rat and the introduced Norwegian
rat populations on the island; Anne
Stewart, to study the native Tui bird popu-
lation and compare their song and other
characteristics with the New Zealand na-
tive Tul bird; Mark Vette, a great climber of

trees, which was very much appreciated
when antennae went up and down, whose
main fob was assisting both John and
Anne in their studies (Mark is by trade a
very capable scientist in animal behavior
patterns); Dr. David Schiel, a marine
biologist and an extremely good diver (he
assisted when disaster struck the yacht};
and Mike Kingsford, another marine
biologist studying fish life and migration
patterns from the northern Pacific down
to New Zealand. For his investigations,
Raoul Island is a very handy "half-way
house" for the migration patterns.

The amateur radio party consisted of
Ron Wright ZL1AMO/ZL8AMO {and many
other DX calls— the CW expert who
worked approximately 10,000 QSOs); John
Litten ZL1AAS/ZL8AAS, who mainly oper-
ated phone and stacked up about 5000
QSOs; Roly Runciman ZL1BQD/ZL88QD,
who operated both phone and CW on all
bands, also working 10,000 QSOs; and
Duane Ausherman WBREC/ZLQAOVW
ZLGADVW8, who operated both SSB and
CW with slightly more emphasis on CW
and did very well with 5000 QSOs for his
first DXpedition.

Journey to Raoul: The journey-to- Raoul
routine consisted of three hours on watch
and six hours off for the five days. Time is
measured by daylight and darkness rather
than by the days of the week — every three
hours another shift comes on and the one
going off gets a quick bite to eat and then
tumbles into bed.

One of the amazing occurrences during
the voyage was seeing the small "Wel-
come Swallows" along with other bird life
with land two or three hundred miles away
in either direction. The scientific experts
when asked, "Where do they go at
night?", replied, "Ohh back home again;
they can fly enormous distances, and they
will be back here again tomorrow!" Then
there were the dolphins riding our bow
wave. , .and the spectacular sight of see-
ing the seas burst Into green light with
phosphorescence during the small hours
of the morning watch. And there were the
moths and butterflies three hundred miles
from land; where do they come from?

Every hour the travelling log is read and
entered into the ship's tc-g„ and every day
we call up Auckland Radio and "home"' to
give positional reports and get the latest
weather information.

After four days of nothing we sight the
first island of the Kermadec Group, Esper-
ance flock. Later that day we passed be-
tween the next group of Islands, Curtis
island, which is still an active volcano
with quite a bit of steam escaping from
the craterP and Cheesman Island, with an
extinct volcano, covered with quite bushy
vegetation and inhabited by bird life. Soon
radio contact was made with Warrick
ZL8AFH via Marine Channel 16, and we
are told to lay off as close to the landing
platform as we like. The great moment is
at hand; we have arrived at Raoul island!

Landing: Landing ai ftaoul is a very
delicate task. There Is no Jetty or wharf.
Goods and chattels have to be landed by
being lifted from small boat to the landing
platform by a manually operated crane us-
ing a cargo net. Mere humans have to
clutch a ladder attached to the crane hook
and hope that the crane operator knows
what he's doing in the winch house! Judg-
ing the position of the ladder relative to
the swells is quite a feat.

The small landing boat, Chunder
[Ed. — A down-under word meaning throw
up], Is well named and it, along with every-
thing else, makes the journey up the cliff
from the landing platform, "the flying
fox," hauled by yet another manually op-
erated winch, quite exciting.

Once at the top, there is conclusive
proof that we are Indeed on Raoul Island,

73 Magazine * November, 1984 93

lor we are confronted with a targe notice
with instructions "to prevent damage to
the vegetation and the natural features of
(he island/

Our Temporary Q7H: Raoul Island is
Quite a paradise in the South Pacific. It is
at fit an active volcano with upwards of six
earthquakes per day, most not felt fry
those on the island, though one or two
heavier jolts reminded us of the continued
activity. Most of the Island is covered in
Nlkau palms as a type of undergrowth,
with a canopy of beautiful Fohutukawa
trees overhead r Along the northern coast-
line is a self-sufficient form which sup-
ports the permanent residents on the
Island. The coastline is extremely rugged,
with only a very smaN rocky beach along
the western coast where the original sei-
ners, the Bell family, used to live many
years ago, There are si Ml a few goats and
many wild cats on the island, and, of
course, lots of rats. Bird life is quite preva-
lent, with the song of the Tiji making the
bush come alive The oranges from the
orange grove have to be tasted to be be-
lieved, and delicious bananas grow freely
as we4L

The personnel on the Island are a terrif-
ic band of fellows* and they treated the ex-
pert ft loners very well during their slay, es-
pecially when the tragedy with the yacht
occurred a few days after arrival. Mike (the
officer In charge) took cere of the landing
formalities, passports, etc, end settled us
Into our quarters; Paul (Lands and Survey
Department) was our Island lour guide
and was a tower of sirength; Garth (Met
Office) was the Raoul Island champion
table-tennis player, who was deposed by
RoJy ZL8BQD. Garth is also the photo-
graphic expert in the group. Tom is the
resident mechanic and an expert cook in-
to the bargain; and Warrick ZLSAFH was
the technician and radio operator. When
the amateur DXpedmon left the island,
they left Warrick a triband beam and
various assortments of wire and coax, so
his signals on the higher frequencies
should be better than they were before.

The Amateur DXpedition: Radio opera-
tion was the amateur highlight of the trip
and, of course, one ol the reasons for the
expedition. Some 30,000 QSOs were made
with all points of the globe, propagation
being good on all bands at some time
every day. Antennas were a 160780m di-
pota, up about 80 feel between two very
high Norfolk Pine trees, and two triband
beams. Equipment used were the I COM
IC-745, IC-740, ICOM Auto Tuners, and the
Kenwood T&330 and TS-430

The OXpedition again tried to cater to
as many facets of (he hobby as possible,
especially QflP operation. For those

stateside stations who stood by to enable
the expedition to do this, they extend
the»r grateful thanks. The best ORP was
with N6HJ with 100 milliwatts, believe it or
not. and many stateside stations gave the
report. I don't know how ORP I am, but
nothing is moving heref ' Great stuff fel-
lows, hope we can do it again sometime
from other Pacific OX locations.

One QSO that made a nice change was
being called by BY1PK, an unusual switch
that waa appreciated by all. Also the oper-
ators would like to make special mention
of Werner DM9 KE and his net on 21,157
MHz; thanks Werner for getting so many
of the Europeans through to make those
valuable ZLB QSOs.

Disaster Strikes: Life was Quite exotic
until March 21 , three days into the opera-
tion, when Cyclone Cyril made Its way
down from Tonga and struck the island in
the smalt hours of the morning amidst
driving rain, total darkness, and driving
seas. Al 12:15 am the anchor ropes hold-
ing our yacht, Shiner, broke and allowed
me boat to note itself against the rocks in
Boat Cove. Our Captain, John Taylor, and
two of the scientists were on board at the
time and had to abandon ship Into their
Avon landing craft amidst all the ele-
ments. They made their way to shore to a
landing over very large and dangerous
rocks, All they had to guide them was the
light of two torches held by the shore
party to show them a "channel" They
were indeed fortunate io catch the right
wave end surf over the rocks to make a
scrambled, but safe, landing

We were indeed fortunate no lives were
tost. The boat was a total loss, Including
quite a bit of personal gear on board Our
hosts on the island together with the
oceariographers from the scientific party
did a tern fie job salvaging what was pos-
sible from the wreck over the next two
days, A bit of a damper to the expedition,
but when it was known that no lives were
lost, the radio operation could at least
carry on with easier minds. Of course,
they now had to find a way to make al-
ternative arrangements for the trip back
to New Zealand. After several different
alternatives, they finally had to accept the
offer of a diversion pick-up by the coastal
freighter MV Vifa en route from Tonga to
Auckland, The cost of the diversion was
$3,000. an added expense they had not
counted on, but there was no choice,

So, after an uneventful trip home, apart
from a little seasickness, the expedrt ton-
ers arrived back in Auckland for a reunion
with their families: so ended the trip of a
lifetime to the rare and exotic Kermadec
islands.

BITS *Nf PIECES

One of the chores the members ol the
Kermadec expedition told us about was
the baking of their own bread and the trou-
ble they had Keeping track of which loaves
were Ihe fresh ones. Amateur ingenuity
and some food dye came through with the
answer— color-coded bread, a great idea
so long as someone remembered the col-
or coding

More 6m VHF news from Terry ZL2TPY
indicated that April provided more sur-
prises with every type of propagation tak-
ing place during the month; sporadic-E.
F2, TEP {Class 1 and 2), Backscatter, and
tropo, etc. His running total of 6m QSOs
for the last four and half months has well
passed the 1000 mark (nothing under 160
kms) with over 600 plus stations worked.
The overseas DX within the Pacific Basin
and the Slates continues with ihis
month's total bringing up his total of call
areas worked to 39 for the same period,
The J A totals for the past summer season
to April was 440 J As. all 10 Districts, and
54 JA prefixes so 6 was very much alive in
ihe early part of this year.

Old-Timers Club news for the month In-
cluded a 50-year Certificate to Honorary
Member Mrs. Ausline Henry VK3VL and
60-year Certificates to Frank Bell ZL4AA
(ZL's first amateur} and Bern Spackman
ZLIGV. ex 228 M. Silent Keys recorded
were Morrle Walker ZL1AU, ex ZL3FQ,
Wally Watnwright ZL2IS, ex ZL2IE, and
Clinton Way, ex ZL2JC, and Sydney Car-
penter,

OTG Awards made at the annual meet-
ing of (he Club held during the NZABT
Conference recently were to Arthur Allen
ZLUQ; who is the Grand Old Man iPresi
dent) for the 19&4/B5 year, and the Mom
gomery Cup, for the best contribution to
Break-In, went to George Anderson
ZL2JG, for his Several contributions to
Break In during the past year.

NORWAY

Bforn-Hugo Ark LA5YJ
N-3120 Andebu
Norway

Here we are again, t sincerely hope you
ait have had a pleasant vacation, nice
weather, etc l have had the pleasure to be
able io join in on a couple of ham meet
ings, and I will today take you io Ihe tng-
gesf ham festival in Europe, The HAM-64,

at Friedrichshafen. southern Germany (or
Bodensee Treften." which it's also called
since Friedrichshafen lies on the shore of
the Bodensee, facing the Swiss border).

We were three ham operators taking the
ferry from Oslo to Kief in northern Ger-
many, and we drove ihe 1000 kms south to
Friedrichshafen in one day. Henry LA3FI,
the owner of Norsk Radio Supply, took
care of the driving and Brynjar LAI AR and
f took care of the mapping and sign read-
ing. We never left the Autobahn except for
refuting the car and the stomachs
LASFTs Mercedes never got below the
lOOkm/h mark, and very often it was
closer to 200 kmm. Certainly we did not
see much of the landscape.

We came down to Friedrichshafen and
had quite some problems in getting Eodg
ing, but managed after a while to get
booked in at a couple of small hotels Re-
member, when traveling In Germany, to
take your own soap with you if you want to
shower, We didn't remember, but a little
organizing worked thai out

The very next day we had the pleasure
to see the biggest and nicest place for a
ham operator to see. Gee, man. even we
who work in the business were amazed,
And the flea market overflowed with all
kinds of surplus and used gear. We spent
some good times chatting with exhibitors
from all over the world. We did have the
great pleasure to meet Mr Bob Cushman
from the Cu she raft company and spent
quite some lime chatting about antennas,
A very pleasant meeting indeed, both per-
sonally and business-wise.

Other exhibitors Included, of course,
Telex-Hy-Gam, and we did have a couple
of nice chats there, too. There's only one
drawback in dealing with US companies
these days, the US dollar is so extremely
expensive at this time. During the last six
months it has gone up 16 percent, and
that is very hard on amateurs. Raw mate-
rials have been raised 20 percent, and it's
really a killer for business. But anyhow,
we did enjoy Ihe whole exhibition.

Later that evening we had the pleasure
to loin the ham party and had a very nice
chat with Kurt HB9MX and Baldur OJ6SL
The latter Is a very famous DX pedit loner
who you certainly have worked from a few
of those far-off rare DX countries.

We also mat BJorn SM6EHY, who imme-
diately got tired up on low-band DXing I
will write about Bjorn in a later column.
One thing that really surprised me was the
generally friendly altitude shown by
everyone (o eireryone It was just a great
pleasure to be a foreign visitor. As a DXer,
l certain ly pot interested in the D ARC'S DX

Continued on page J00

Kurt HB9MX {right) showing his scrapbook to Baldur DJ6SL

94 73 Magazine * Novembert1984

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73 Magazine * November, 1984 97

10th

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from page 94

stand and had nice chats with a few of the
guys behind the stand

We did of course, take the opportunity to
use the hospitality given by the combined
representatives from ihe Post and Tele-
graph services In Austria. Switzerland.
Uchtensteln, and Germany, who on the
spot issued visiting licenses on a recipro-
cal basis without any fees at all. I person-
ally had the opportunity to obtain LA5YJJ
HB, LASVJ/HBt, DULA5YJ. and trie
tongue-breaking 0£iXFBrt_A5YJ, Only the
French representative was missing, and
we were missing him.

As you may have gathered already, we
did take a trip through Austria. Uchierv
stem, Switzerland, France, and Germany,
but unfortunately we did only bnng a 2m
FM rig this lime, and I had ihe pleasure of
chatting with amateurs from all of these
QTHs except from France, where we
couldn't obtain a license on such short
notice. The only thing that took some
pleasure off the trip was the weather.
Maybe someone disliked the kind of rf I
was transmitting through the air! It was
raining like I have seen only in the tropics,
and i'm sure that part of the world got
enough rain to put the Sahara Desert
under water during lhat day.

Everyone assured us that this was very
unusual; normally the weather should be
nice and sunny this time of the year. How-

ever, next time we're going to bring with
us an HF rig and spend some time in each
of the countries trying to create a few pile-
ups. I'm sure the weather will be much bet-
ter then. I will say that if you get the oppor-
tunity to go to Europe during the last part
of June nest year, take the chance and
join in on the Boojensoe-treffen 1SS5. You
surely won't regret il. If interested, write to
DARC-Oeutscher Amateur-Radio Club
e.V., 3507 9a u natal, LmdenaUe 6, Ger-
many. The affair Is absolutely one of the
best I have attended, and remember, it's
onty for nam radio,

BJARNE ERIKSEN LA4HF

I would like to present to you another
DXer from Norway, one of those you never
near too much from or about, which does
not mean that he is not one of the big
ones. Just the contrary. Depending on
what you consider as a "Big Gun" — one
with a big antenna farm, big equipment, or
the capability to get the rare ones —
Bjame P. Eriksen LMHF, from LikoJlen,
near Oslo, belongs to the last category.
He was bom in Ihe southern part of nor-
thern Norway in 1928, and will soon be 56,
He was first licensed In 1955 and was real-
ly bit by the bug when he worked his first
real rare one in 1958, VKflTC. on 15-meter
AM. Since then it seems thai his Interest
In DXFng has just increased, though it has
rmv^t taken control over his life and work.

Bjame lives with his wife. Liv, In a one-

story house In a suburb of Oslo, Around 20
km from the inner city, nothing except the
12-meter-high tower with a Classic 33
from M os ley can pick him out as being
any different trom all the other people liv-
ing around there. He also has a multiband
trap 01 pole lor local 80- and 40-meter work,
since he never has taken any Interest in
low-band DXIng.

His equipment has been for many years
a Yaesu FT-50Q. but last year he realized
that the rig was starting to get a bit too
old. and he traded It in for a brand new
Yaesu rig, the FT9B0 CAT, You can imag-
ine his happiness about this rig. Even
though he thought quite well about the old
one, which had served him wet) for so
many years, his answer to my question
the other night, if he would like to switch
back was rather short and precise: No
way? And you know, the new toy got the
flame burning a little higher. He Is teal I y
sincere about his hobby, and it relaxes
him from his work as a Managing Director
at E. Stephesen AS. in Oslo— a firm spe-
cializing in hearing aios

When I was visiting him t tried hard to
move him into buying a new tower and a
bigger antenna, but he was concerned
about his neighbors, The idea is not new
to him, ho»ewar: 1 think lime will teti!

Bjame has managed to work 30W31B
and is si til waiting to work such easy
goodies as 4U1UN. ZUChatbam, XF4, and
BY I know that Bjarne would be very hap-
py II anyone working from those locations
could give htm a hint about when they will
be active In addition to his FT-98Q, he has
an SB-230 linear, Amtor Mkll from ICS
electronics, and a BBC model B com-
puter.

LMHF has other interests as well. He
loves traveling and is starting to be a little

globe-trotter He has been visiting HS, CN,
3 Vfl> SV5, and 5Z4 and is planning to pay a
longer visit to HB9 this summer. He also is
very interested In sait -water fishing and is
very happy to pull up a couple of big cod.

Bjame is very happy to spend time chat-
ting with people and does not mind rag-
chewing at ail, but a new one gets him
always on the tense side, SO to speak. Un-
derstandable, and I sincerely wish him
luck towards the DXCC Honor Roll, where
I. personally, think he belongs.

In another column I will present to you
Bjorn 5M6EHY of Sweden and another
ham meeting we have been to.

Take good care, my friends, see you
BOOR.

POLAND

Jerzy Szymcza*
73-200 Biatogatd
Buczka 2/3
Poland

On January 28, 1984, the plenary ses
si on of Headquarters of PRAA (Polish
Radio Amateurs Association) took place
in Warsaw Important resolutions that will
exert an influence on the future activity ot
Pofish hams were adopted The PRAA
electoral campaign began in February.
Elections or delegates to district conven-
tions were to take place at electoral meet-
ings of radio-amateur clubs from February
1 to March 31 The district conventions
elect deputies to the National Congress
of PRAA in October or November. AM

Bjame LA4HF tn front of his operating desh

LA4Hf't antanna farm. Fne wild climbing plant adds an unusual touch

100 73 Magazine • November, 1984

LA4Hf's QTH during Christmas season.

Director C. C Lee of Post and Telecommunications with Mr. Shozo Hara, Deputy Director

Shiht and Tim Chen. (Photo by 6V2A)

DXFF members, Second and fourth from the left, front row, are old-timers. (Photo by

BV2A}

holders of valid licenses may have a share
in the district conventions as ordinary
members; on the other hand, persons who
are bringing their licenses up to date may
take part in them as "extraordinary mem-
bers" if they are elected by a club. One
deputy to the National Congress is to be
elected for every 20 ordinary delegates to
district conventions. Candidates elected
by simply majorities are to be deputies-
the number of deputies from each district
depends on the number of members at the
district conventions,

The Presidium of PRAA hopes that
more former radio amateurs will resume
their activities. The pity is that so many
ex-hams do not apply for licenses. The
spirit is willing but the flesh is weak?
Some radio fans did not regain their
licenses. They appealed to verification
boards and in some instances received
their longed-for papers. To encourage in-
different hams, the time for bringing
licenses up to date has been extended for
three months,

Considering trie reduced number of
radio amateurs, the Headquarters of
PRAA made a decision to propose the liq-
uidation of the functions of agents in
some districts of Poland. The former
agents are to hand over documents to
other appropriate District Departments of
PRAA. The District Departments of PRAA
are authorized to commission the former
agents to continue their functions or to
designate others. From February 1, the
radio amateurs of districts Bieisko Pod-
laskie< Chelm, and Zamosc belong to the
district of Lublin; the radio amateurs of
districts Ciechanow and Ptock go to the
district of Warsaw; Przemysl goes to
Rzeszow; Slupsk to Koszalin; Walbrzych
to Wroclaw; Wloctawek to Bydgoszcz; and
Tamobrzeg and Radom to Kielce. These
organizational changes are to render the
administration of PRAA more efficient.

Norms for staffing of PRAA are exceed-
ed, the Presidium says. Salaried workers
shouid be replaced by active hams.

At the request of the vice-president of
PRAA Headquarters, SP3AU2 {the Poiish
RadJo Vldeography Club) was founded on
January 23, this year.

TAIWAN

Tim Chen BV2AWV2B
PO Box 30-547
Taipei, Taiwan

Republic of China

After decades of endeavor,, we are
pleased to see thai the Chinese govern-

+* See List ot Advertisers on page 88

rnent has decided to renew the licensing

system with a ceiling of 12 ham stations
to be distributed in 4 districts. The north-
ern district will be alfotted 4 stations, cen-
tral 3, southern 3, and eastern, 2, We antic-
ipate many license applicants, and the
limit of 12 stations will not meet the de-
mand.. To soive this problem^ club sta-
tions will mostly be the way to absorb
more operators at the beginning.

The regulations governing ham-radio
stations are under revision. The usable
frequencies allowed will be only on the
40-, 20-r 15-, and 10-meter bands. The
China Radio Association f,CRA) is re-
questing the authority to add the 80-meter
band for ham use in order to facilitate
5-band QSO possibilities. VHF and UHF
are still out of the question. However,
144/430 were recently used by the Japan
DXFF DXpedition on a temporary basis,
so it is possible we can apply for them in
like situations.

The Directorate General of Telecommu-
nications (DGT) will give public examina-
tions once or twice in a year. The first ex-
amination was scheduled for September.
All participants have to pass the qualifica-
tion test. It covers Morse code at 30 wpm
on both sending and receiving for 3 min-
utes, radio principles, electricity prin-
ciples, telecommunications law, interna-
tional radio regulations relevant to ama-
teur radio, English, and communications
geography. Oral tests on alphabetical and
numeral spellings are also required.

DXFF DXPEDITION

The Japan DXFF DXpedition group con-
sisted of 12 members, including two XYLs
and one reporter/photographer They were
divided into three teams and arrived on
June 8, 13, and 14, respectively. As usual,
the ham visitors wasted no time setting up
station BVOJA/BV0YL and antennas im-
mediately after their arrival in Taipei. The
DXpedition venue was at the same p^ace
which had been used by former groups. It
Is facing a public park, with a spacious
roof on a 12-story building for antenna in-
stallation good towards east, north, and
west.

The special caNsigns BVfflJA and
BVOYL were assigned for use by the OMs
and YLs of the group. By estimate, over
15,000 QSOs were made during the 10 day
operation. The most outstanding aspect
of the DXFF group was the operation on
144/430 with AO-10 (B), from which nearly
200 QSOs (CWVphone) covering 4 conti-
nents (excepting South Africa and South
America) were obtained. It is a record for
ham operation with satellites in this area.
We have informed the DXGC of these op-
erations and callsigns which had been ap-
proved by the Chinese Government and
considered legal for DX credits.

Shozo Hara JA1AN, president of JARL,

DXpedition station BVQJA/BMYL

recently made a courtesy call on C. C. Lee,
Director of Post and Telecommunica-
tions, MOC. Their talk about world ama-
teurs was fruitful and meaningful in pro-
moting ham activities in our country.
Therefore, further cooperation between
JARL and CRA Is expected, A second Jap-
anese group was to visit BV-land in July,
and the callsign BVGAB was requested for
the mission.

After expedition activities, our visitors'
stations had materially improved QSOs to
world hams; we should be very apprecia-
tive of their efforts as they spent lots of
time and money to carry out their mis-
sions. Perhaps there will be two bigger
groups scheduling arrivals this fall:
please looK out for them.

Local authorities have so far approved
four expedition groups from abroad; we
are going to strengthen the ham move-

ment gradually, although we do not have
many stations at present.

There Is no doubt that ham activities
have become popularized step by step in
this land. Enquiries by letters and phone
calls are frequently received. Newspapers
and the broadcast media are quite encour-
aging, giving us good comments. Further-
more, one of local TV stations, the CTS,
had a vivid telecasting of our activity in its
news program on prime time, Its lady re-
porter, Miss Lee, said, "Now I am also
tempted by the hobby E" Ht ¥L! Welcome
to amateur radio!

JLWhy not have a telephony c!ass?M
asked Dr. Wayne Green W2NSD during his
sojourn in Taipei with his XYL, Sherry,
recently. (Congratulations, Dr. Green, for
your new title.) You should be also pleased
to learn that we are stepping forward, but
we have to stick on CVW phone at the
beginning, Thanks for your concern]

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GRAND LEDGE, MICHIGAN 48837

73 Magazine * November, 1984 101

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4PR60A

200.00

6883B/8032A/8552

10.00

6GF5

5.85

4PR50B

345.00

6897

160.00

6GJ5A

6.20

4PR65A/8187

175.00

6907

79.00

6GK6

6.00

4PR10GQA/8189

590.00

6922/6DJ8

5.00

6HB5

6.00

4X150A/7034

60 . 00

6939

22.00

6HF5

8*73

4XI50D/7609

95,00

7094

250.00

6JG6A

6,28

4X2 SOB

45,00

7117

38.50

60 M6

6,00

4X250F

45,00

7203

P.O.R.

60N6

6.00

4X500A

412,00

7211

100,00

6J56C

7.25

5CXI500A

660, 00

7213

300.00*

6KN6

5.05

KT88

27.50

7214

300.00*

6KD6

8.25

416B

45.00

7271

135.00

6LF6

7.00

416C

62.50

7289/2C39

34.00

6LQ6 G.E.

7.00

572B/T160L

49.95

7325

P.O.R,

6LQ6/6MJ6 Sylvania

9.00

592/3-2O0A3

211.00

7360

13.50

6ME6

8.90

807

8,50

7377

85,00

12AT7

3.50

81 1A

15.00

7408

2.50

12AX7

3.00

812A

29.00

7609

95.00

128Y7

5,00

813

50.00

7735

36.00

12JB6A

6.50

NOTE * = USED TUBE

MOTE P.O.R. = PRICE ON REQUEST

MALL PARTS MAY BE NEW, USED, OR SURPLUS, PARTS MAY BE SUBSTITUTED WITH COMPARABLE PARTS IF WE
ARE OUT OF STOCK OF AN ITEM.

NOTICE: ALL PRICES ARE SUBJECT TO CHANGE WITHOUT NOTICE.

For information calk (602) 242-3037

Toll Free Number
800*528-0180

(For orders only)

"All parts may be new or
surplus,, and pacts may be
subslitgted witft comparable parts
if we are out of stock of an Item."

(fjM^Hz elect roi|ic§

PRICES SUBJECT TO CHANGE WITHOUT NOTICE

102 73 Magazine • November, 1984

"FILTERS"

COLLINS Hechonical Filter #526-9724-010 MODEL R55Z32F

455KHZ at 3,2KHz wide. May be other models but equivalent. May be used or new, $15t99

ATLAS Crystal Filters

5. 595-2. 7/8 /LSB, 5,595-2.7/LSB

8 pole 2,7KHz wide Upper sMebard, Inpedence SOOohms 15pf In/SOGolms Opf out- 19,99

5 .59 5-2 .7/8 /U, 5.595-2.7/USB

8 pole 2,7Khz wide Upper sideband, Impedence SOOohms 15pf In/800ohms Opf out* 19*99

5. 595-. 500/4, 5,595-,500/4/CW

4 pole 500 cycles wide OT. Impedance SOOohms 15pf In/BOOohms Opf out, 19,99

9 . 0USB/CW

6 pole 2,7KHz wide at GdB. Impedance 680ohms 7pf In/300ohms 8pf out* CW-1599Hz 19.99

KOKUSAI ELECTRIC CO, KechonlCQl Filter #MF-455-ZL/ZU-21H

455KHz at Center Frequency of 453, 5KC, Carrier Frequency of 455KHZ 2,36KC Bandwidth.
Upper sideband, (ZU) 19.99

Lower sideband. (ZL) 19.99

CRYSTAL FILTERS

NIKKO

TEW

SDK

TYCO/CD

MOTOROLA

PTI

CQKTECH

FFC

FILTBCH

FX-07800C
FEC-103-2
SCH-113A
TF-31H250

001019880

4884863B01

5350C

5426C

1479

A10300

ERXF-15700

2131

7, 5MHz

10.6935MHz

11, 2735MHz

CF 3179. 3KHZ

10.7MHz 2pole 15KH2 bandwidth

11, 7MHz 2pole lSKHz bandwidth

12MHz 2pole 15KHz bandwidth

21, 4MHz 2pole lSKHz bandwidth

10* 7MHz Spole bandwidth 7,5KHz at 3dB, 5KHz at 6dB

45MHz 2pole 15KH2 bandwidth

20.6MHz 36KHz wide

CF 7.825MHz

$10,00
10.00
10,00
19,99
5,00
5.00
5,00
5,00
20.00
6.00
10.00
10,00

fri^^ttftt^ttftfrftttttSffftttfttttflttftt****^*^***************^*************}****^!*^^*^***

CERAMIC FILTERS

AXEL
CLEVITE

MUPA^m

MIPPON

TOKIN
MATSUSHIRA

4F449

TO-01A

TCF4-12D36A

BFB455B

BFB455L

OT4455E

CFM455D

CFR455E

CFU455B

CFU455C

CFU455G

CFU455H

CFU455I

CTO455D

CFTC455H

SFB455D

SFD455D

SFE10.7MA

SFE10.7MS

SFG10.7MA

LF-B4/GFU455I

LF-B6/CFU455H

IF-B8
LFH^IS

CF455A/EFU455K
EFC-L455K

12,6KC Bandpass Filter 3dB bandwidth l.GKHz from ll.3-13.4KHz

455KHz-i-2KHz bandwidth 4-7% at 3dB

455KH2-I-1KH2 bandwidth 6dB min 12KH2, 60dB max 36KH2

455KHz

4 55KHZ

455KHz -I-5.5KHZ at 3dB , +-8KHZ at 6dB , ~KL6KHz at 50dB

455KHz 4-7KHz at 3dB , +-10KHz at 6dB , ^20KH2 at 50dB

455KH2 +~5,5KEz at 3dB , +-8KH2 at 6dB , +-16KHZ at 60dB

455KHz -I-2KHZ bandwidth +-15KHz at 6dB, -i-30KHz at 40dB

455KHz 4-2KHz bandwidth 4-12. 5KHz at 6dB , 4-24KHZ at 40dB

455KH2 4-lKHz bandwidth -l-4,5KHz at 6dB

455KHz 4-lKHz bandwidth +-3KHZ at 6dB ,

455KH2 -1-lKHz bandwidth -i-2KHz at 6dB ,

455KHZ -H10KHZ at 6dB , +-20KHZ at 40dB

455KHZ 4-3KHZ at 6dB , 4-9KHz at 40dB

455KHz

455KHz -I-2KHZ * 3dB bandwidth 4.5KH2 -r-LKHz

10.7MHz 280KHz 4-50KHZ at 3dB , 650KHZ at 20dB

10,7MHz 230KH2 +-50KHZ at 3dB , 570KH2 at 20dB

10,7MHz

455KHZ -H-lKHz

455KHZ 4-1KHZ

455KH2

455KHz

455KHZ -I-2KHZ

455KHz

lOKHz at 40dB
9KH2 at 40dB
6KHz at 40dB

10.00
5,00

10,00
2,50
3,50
6,65
6,65
8.00
2,90
2.90
2,90
2,90
2,90
2*90
2,90
2.50
5,00
2,50
2,50

10.00
2,90
2,90
2,90

10,00
5.00
7.00

SPECTRA PHYSICS INC. Model 088 HeNe LASER TUBES

POWER OUTPUT 1.6MH. BEAM DIA, *75MM BEAM DIE, 2,7MR

68K OHM IWATT BAIiAST 1000VDC +-100VDC At 3t7MA

RQTRQN MUFFIN FANS Model MARK*./MU2A1

IMPEDENCE PROTECrED-F

SKV STARTING VOLTAGE DC

$59,99

115 VAC 14WATTS
105CFM at 60CPS

50/6 0CPS

THESE ARE NEW

8SCFM at S0CPS

J\f ^Ijjfc electroqic$

PRICES SUBJECT TO CHANGE WITHOUT NOTICE

Toll Free Number
800-528-0180
(For orders only)

$ 7,99

"All parts may be new or

surplus, and parts may be
substituted with comparable parts
rf we are out of stock ot an item."

For information call: (602) 242-3037

73 Magazine + November, 1984 103

TYPE

PRICE

RFTR

TYPE

[ANSI

PRICE

STOF

TYPE

PRICE

TYPE

PRICE

2N1561 i

£25.00

2K5920 $

70.00

40608 RCA

$ 2.48

BFY90

$ 1.50

2N1562

25.00

2N5921

80.00

40673 RCA

2.50

BLW60C5

15,00

2N1692

25.00

2N5922

10.00

40S94 RCA

1.00

BLX67

12.25

2N2857

1.55

2N5923

2 5 . 00

60247 RCA

25.00

BLX67C3

12.25

2N2857JAN

4.10

2N5941

23.00

61206 R.CA

100.00

BLX93C3

22,21

2N2S57JMTX

4.50

2K5942

40.00

62800A RCA

60.00

BLY87A

7,50

2N2876

13.50

2N5944

10.35

62803 RCA

100.00

BLY88C3

13.08

2N2947

ia.35

2N5945

10.00

43041 4/3990RCA 50,00

BLY89C

13.00

2N2948

13.00

2N5946

12.00

3457 J 59 RCA

20.00

BLY90

45.00

2N2949

15,50

2N5947

9.20

3729685-2 RCA

75.00

BLY92

13.30

2N3118

5.00

2N6080

6.00

3729701-2 RCA

50.00

BLY94C

45.00

2N3LI9

4.00

2N6081

7.00

3753883 RCA

50.00

BLY351

10.00

2W3134

1,15

2N6082

9.00

615467-902

25.00

liLY568C/CF

30.00

2M3237

4-90

2N6083

9.50

615467-903

40.00

C2M70-28R

92,70

2N3288

4,40

2N6084

12.00

2SC56&

2.50

C25-28

57,00

2N3309

4.85

2H6094

11,00

2SC703

36,00

C4005

2,50

2N3375

17.10

2N6095

12.00

2SC756A

7.50

CD 16 59

20.00

2H3478

2.13

2N6096

16.10

2SC781

2,80

CD1899

20.00

2N3553

1.55

2N6097

20.70

2SC1018

1 .00

CD1920

10.00

2N3553JAN

2.90

2N61G5

21.00

2SC1042

24.00

CD2188

18,00

2M3632

15.50

2N6136

21,85

2SC1070

2.50

CD2545

24.00

2N3733

11.00

2N6166

40.24

2SC1216

2.50

CD2664A

16,00

2N3818

5.00

2N6267

142,00

2SC1239

2.50

CD3167

92.70

2N3866

1.30

2N6304

1.50

2SC1251

24,00

CD3353

95,00

2N3S66JAN

2.20

2N6368

30,00

2SC1306

2,90

CD3435

26,30

2N3866JANTX

3.80

2N6439

55,31

2SC1307

5,50

CD3900

152,95

2N3866JANTXV

4.70

2N6459

18,00

2SC1424

2.80

CM25-12

20,00

2N3866AJAMTXV

5.30

2N6567

10,06

2SC1600

5.00

CM40-12

27,90

2N3924

3.35

2N6603

13.50

2SC1673

2,00

CM40-28

56,90

2N3926

16.10

2M6604

13.50

2SC1729

32,40

CME50-12

30.00

2H3927

17.25

2N6679

44.00

2SC1760

1,50

CTC2001

42,00

2N394S

1.75

2N66S0

80,00

2SC1909

4,00

CTC2005

55 , 00

2N3950

25.00

021-1

15.00

2SC1945

10.00

CTC3005

70,00

2N3959

3,85

01-80703T4

65 . 00

2SC1946

40,00

CTC3460

20,00

2N4012

11. 00

35C05

15.00

2SC1947

10,00

DV2820S

25.00

2N4037

2.00

102-1

28.00

2SC1970

2.50

DXL1003P70

22.00

2N4Q41

14.00

103-1

28.00

2SC1974

4.00

DXL2001F70

19.00

2N4072

1.80

103-2

28.00

2SC2166

5.50

DXL2002P70

14,00

2N4080

4.53

104P1

18,00

2SC2237

32,00

DXL3501AF100F

47.00

2M127

21.00

163P1

L0.00

2SC2695

47.00

KFJ4015

12,00

2N4416

2.25

181-3

15.00

A2XI698

FOR

EFJ4017

24.00

2114427

1.25

2 10-2

10. oo

A3- 12

14.45

EFJ4021

24.00

2H442S

1.85

269-1

18.00

A50-12

24.00

EFJ4026

35.00

2M430

11.80

281-1

15.00

A209

10.00

EN15745

20,00

2N4927

3.90

282-1

30,00

A283

6.00

FJ9540

16.00

2M957

3.45

482

7,50

A283B

6.00

FSX52WF

58.00

2N4959

2.30

564-1

25.00

A1610

19,00

G65739

25,00

2N5016

18.40

698-3

15 , 00

AF102

2,50

£65386

25.00

2N5G26

15.00

703-1

15,00

AFY12

2.50

CiMG290A

2.50

2H5070

IS. 40

704

4,00

AR7115

20,00

HEF76

4.95

2H5090

13. SO

709-2

11.00

AT4I435-5

6,35

HEPS3002

11.40

2N5108

3.45

711

4,00

B2-8Z

10.70

HEPS 3003

30,00

2N5109

1.70

733-2

15.00

B3-12

10.85

HEPS3005

10,00

2N5160

3.45

798-2

25.00

BI2-12

15,70

tiEFS3006

19.90

2N5177

21,62

3421

28,00

BAL0204125

152.95

HEPS 300/

25.00

2S5179

1.04

3683P1

15.00

BF25-35

56.25

HEFS3G10

11.34

2N5216

56.00

3992

25.00

B40-12

19.25

HF8003

10. 00

2N5470

75.00

4164P1

15,00

B70-12

55.00

HFET2204

112.00

2N55S3

3.45

4243P1

28.00

BF272A

2,50

HF35821

38,00

2^5589

9.77

4 34 OP 3

18.00

BPQ85

2.50

HP35826B

32.00

2N5590

10.92

4387P1

27.50

BFR21

2.50

HP35826E

32,00

2N5591

13.80

7104-1

23.00

BFR90

1.00

HF35831E

30.00

2N5596

99,00

7249-2

10.50

BFR91

1.65

HP35832E

50.00

2H5636

12.00

7283-1

37.50

BFR99

2.50

HP35833E

50,00

2N5637

15.50

7536-1

30.00

BFT12

2.50

HP35859E

75.00

2N564 1

12.42

7794-1

10.50

BFW16A

2.50

HP35866E

44.00

2N5642

14.03

7795

15.00

BFW17

2.50

HXTR2101

44.00

2N5643

25.50

7795-1

15.00

BFW92

1.50

HXTR3101

7,00

2N5645

13.80

7796-1

24.00

BFX44

2,50

HXTR5101

31,00

2N5646

20.70

7797-1

36.00

BFX4S

2,50

HXTR6104

68,00

2N5651

11.05

40081 RCA

5.00

BFX65

2,50

HXTR6105

31,00

2N5691

18.00

40279 RCA

10. 00

BFX84

2.50

HXTR6106

33.00

2N5764

27.00

40280 RCA

4.62

BFX85

2,50

J310

1. 00

2N5836

3.45

40281 RCA

10.00

BFX86

2.50

JO2000

10.00

2N5842

8,45

40282 RCA

20.00

BFX89

1.00

JO2001

25,00

2H5847

19,90

40290 RCA

2.80

BFYli

2.50

JO4045

24,00

2N5849

20.00

40292 RCA

13.05

BF¥18

2,50

KJ35522

25,00

2N5913

3.25

40294 RCA

2,50

BFY19

2.50

KJ5522

25.00

2N5916

36.00

40341 RCA

21,00

BFY39

2.50

Ml 106

13.75

PRICES SUBJECT TO CHANGE WITHOUT NOTICE

800-528-0180

(For orders only]

surplus, and parts nnay be

substituted with comparable parts

i jf we are out of stock of an item/'

For information call: (602) 242-3037

JM<*1

electi

•oiycs

104 73 Magazine * November, 1984

RF TRANSISTORS (CONTINUED)

M1I07

MU31

MU32

M1134

M9116

M9579

M9580

M9587

M958S

M9622

M9623

M9624

M9625

M9630

M9740

M9741

M9755

M9780

K9827

M9848

M9850

H9S51

H9S60

M9SS7

M9908

M9965

MM1500

MMI550

MM1552

MMI553

MMI607

MM16U

MM1810

HML810

MM1943

MM2608

MM3375A

MH4429

MM8000

MM800&

MM80L1

KFSU31

MRA2023-U5

MRF134

MRF136

MR7171

HRF208

MRF212

MRF221

MRF223

MRF224

MRF227

MKF23C3

MRF2 31

MRF232

MRF237

MRF238

MRF239

MRF245

MRF247

MRF304

HRF306

HHF313

MRF314

HKF315

MRF316

MRF317

MRF412

MRF420

KRF421

HRF422

MRF427

MRF428

MRF433

MRF449/A

MRF450/A

MKF452/A

MRF453/A

MRF454/A

MRF455/A

$16.75 MRF458

5,15 HRF464

7,25 MRF466

13*40 MRF472

29.10 MRF475

6,00 MRF476

7,95 MRF477

7.00 MRF479

5.20 HRP492

5.95 MRF502

7.95 MRF503

9 . 95 MRF504

15*95 MRF509

14.00 MRF5H

27-90 MRF515

27.90 HRF517

16.00 MRF525

5.50 MRF559

11.00 MRF587

35.00 MRF605

13.50 MRF618

20.00 MRF626

8.25 MRF628

2.80 . MRF629

6.95 MRF641

I 2. 00 MRF644

25*00 MRF646

10*00 MRF648

50.00 MRFS16

50*00 MHFS23

8*45 MRFS46

10.00 MRFB92

15.00 MRF894

15*00 MEF901 3 Lead

1*80 MRF901 4 Lead

5.00 MRF902/2N6603JAN
17.10 MEF902B

10,00 MRF904

1.15 MRF905

2.30 MRF9H

25*00 MRF965

1.01 MRF966
42*50 MKF1000MA
10.50 MRFI004M
16*00 MRF2001
35.00 MRF2005
11*50 MRF5176
16*10 HRF8004
10*00 MSC1 720-12
13,00 MSC1S21-3
13,50 MSC1S21-10

3.45 MSC2001

2.00 MSC2010

10.00 HSC2223-10

12.07 MSC2302

3*15 MSC3000

13.80 MSC3001

17.25 MSC72002

35,65 MSC73001

31.00 MSC80064

36*00 MSCS0091

50,00 MSr&0099

11*15 MSC80593

29*21 HSC80758

28*86 MSC82001

55.43 MSC820H

63,94 MSC82020M

IS. 00 MSC 82030

20,12 MSC83O01

25.00 MSC83003

38,00 MSC83005

17.25 MSC83026

63.00 MSC83303

12.07 MSC84900

12.65 MT4150

14.37 MT5126

17.00 MT5596(2N)

18.40 MT5768(2N)

20*12 MT8762

16.00 NE02136

520.70
25.30
18*97
1.50
3.10
3.16
20*00
8*05
23#00
1.04
6.00
7*00
5.00
10.69
2,00
2.00
3.45
1*76
11,00
20.00
25.00
12.00
8*65
3,45
25*30
27.60
29.90
33*35
15.00
20.00
44.85
35.50
46.00
1.00
2.00
15.00
18*40
2.30
2.55
2.50
2*55
3*55
32.77
31.05
41.74
54.97
24*00
2.10
225.00
125.00
225.00
30.00
93.00
24S.00
POR
35,00
38.00
FOR
FOR
35.00
10.00
3.00
POR
POR
33.00
33.00
130.00
33.00
40,00
S2.00
70.00
POR
POR
60 . 00
14.40
25.00
99.00
95.00
25.00
2.00

NE02160ER

NEO21350

NE13783

NE2I869

NE57B35

NE64360ER-A

NE64480 (1)

NE73436

NE77362ER

NE98260ER

PRTS637

PT3127A

PT3127B

FT3127C

PT3127D

PT3127E

PT3190

PT3194

PT3195

FT3537

FT4166E

PT4176D

PT4186B

PT4209

PT4209C/5645

PT4556

PT4570

PT4577

PT4590

PT4612

PT4628

PT4640

PT4642

PT5632

PT5749

PT6612

PT6619

PT670S

PT6709

PT6720

PTS510

PT8524

PT8609

PT8633

PT8639

FT 8 6 59

PT8679

PT8708

PT8709

PT8727

PT8731

FT8742

PT8787

FT8828

PT97O0

PT9702

PT9783

FT9784

FT9790

PT31083

PT31962

PTX6680

RE3754

RE37&9

RF35

RF85

RF1I0

S50-12

S3006

S3007

33031

SCA3522

SCA3523

SD345

SDU5

SD1004

SD1007

SD1O07-2

SD 100 7-4

SD 100 7-5

$100.00
5,30
61.00
43.00
5.70
100,00
94.00
2,50
100.00
100.00
25,00
5.00
5.00
20,00
20.00
20,00
20.00
20,00
20,00
7.80
20.00
25*00
5*00
25.00
25.00
24.60
7.50
20,00
5*00
20,00
20,00
20.00
20.00
4*70
25*00
25,00
20,00
25.00
25.00
25.00
15.00
25.00
25,00
25.00
25.00
25.00
25.00
20,00
20,00
29,00
25.00
19.10
25.00
25.00
25.00
25.00
16.50
32.70
56.00
20.00
20,00
20.00
25.00
25,00
16.00
17.50
21.00
23*30
15.00
10.00
22.00
5.00
5.00
5.00
5.00
15.00
15*00
15*00
15*00
15.00

SD1009

SD 1009-2

SD1012

SD1012-3

SD1012-5

SD1013

SD1013-3

SD1013-7

SD1016

SD1016-5

SD 1016-4

SD1018-6

SD 10 18-7

SD1GIS-15

SD1020-5

SD1028

SD1030

SD1G30-2

SD1040

SD1040-2

SD1040-4

SD1040-6

SD1043

SDI043-1

SD1045

SD1049-1

SD1053

SB1057

SD1065

SD1068

SD1074-2

SD 10 74-4

SD 1074-5

SD1076

SD107 7

SD1077-4

SD1077-6

SD1078-6

SD 1080-7

SD108O-8

SD 1080-9

SD1Q84

SD1087

SD1088

SD1088-3

SD1089-5

SD1090

SD1094

SD1095

SD1098-1

SD1100

SD1109

SD1115-2

SD1 115-3

SD1115-7

SD1116

SD1118

SD1 1 19

SD1124

SD1I32-1

SD 1132-4

SD1133

SD1133-1

SDU34-1

SD 1134-4

SD1134-17

SD1135

SD1135-3

SD1136

SD1136-2

SD1143-1

SD1 143-3

SD1144

SD 1145-5

SD1146

SD1147

SD1188

SD1189

SD1Z00

SD 120 1-2

S15.00
15.00
10*00
10. 00
10.00
10,00
10.00
10,00
15*00
15.00
13.00
13,00
13,00
13.00
10.00
15,00
12.00
12.00
5*00
20,00
10.00
5.00
12.00
10.00
3.75
2.00
4.00
10.00
4.75
15.00
IB. 00
28.00
28.00
18,50
4.00
4,00
4.00
24.00
7,50
6.00
3.00
8.00
15.00
22,00
22,00
15.00
15.00
15,00
15.00
30.00
5,00
18,00
7,50
7,50
2,10
5,00
22,00
5,00
50,00
15.00
12.00
9.50
10.00
2.50
12.00
12.00
10,25
12.00
12.50
12.50
10*00
17.00
4.00
15.00
15.00
15,00
10,00
24.00

1.50
15,00

Toll Free Number
800-528-01 SO
(For orders only)

"All parts may be new or
surplus, and parts may be
substituted with comparable parts
if we are out of stock of an item/'

J\f Gl{z electronics

For information call: (602) 242-3037

PRICES SUBJECT TO CHANGE WITHOUT NOTICE

73 Magazine * November, 1984 105

RF Transistors (continued)

SLU202

ssiziz-a

:i;i i :m- - i».
SU 1214-7

SD12U-11
SD1216
SD1219-*
BUl2L'J--r

SD1219-S

suuiq

SD1220-9
SU 122 2-8
SD1222-31

5D1224-SO

gbrtg ■

50UJ5-1
sntwp-r

501333

3DI24CI-B
SD1Z44-I

510. M

*.«

5.M
d,QO

15. M

15.00

15 ♦GO

8*Q0

■J.5A

fl.OO

tft.OQ

7.30

IG.HO

IB .00

i5,nrj

10-95

10.95

4,00

II..Q0

l-i.UO

SD1305
1301307
5lU3Qfl
EDUll

$unu

SHUTS

50134 7-1

9301163-1

5D1365-S

S013?5

GD1375-6

HO 1379

sun PC -I

SD.l3Srj-7

SliUQft
SO 1 409
3D141G

aiuio-j

a"DHLD-4

2.>U

SCK51-2

$15.00

SRH427

550,00

STUfrWU

■25.00

S!J1410-&

j„00

SOUS J

20,00

SM-'tHl

40,00

S01262

15.00

SB1U3-1

i.ou

5D14S2-4

24,00

SEP J 834

40.00

EDI 2*3

15.00

SDUlb

3,00

SD1453H]

20.00

5RP2053-3

60, Od

SO 1263-1

15*00

SD 142 2-2

1.Q0

SBH54-1

*s.tjo

SRFZQtt

50.00

SB 1232

10.95

SO 1428

a.&ti

5DH77

JS.OO

SRF2147

22.LHJ

5P1272-1

10,95

5DL42B-

2*5U

351470

11*00

SRF2225

1 3.U0

^1272-2

1Q.9S

S& 142 9-2

3.M

stiaso

VI, 00

5RFI2fii

35. DO

EC1272-i

10.95

SD 142 9-3

l,M

SD1M4

L.50

SRF22B5

too. 00

SD127H

13*75

5Dl42y-5

2.5(1

5DHS4-5

L.50

SRF22H1

5.00

SPS279-]

13.75

SD141U

2*50

SDJ4B4^

I . so

9RF2371

13,00

SD127B-5

13.75

SO 14 30-2

7.50

SB 1W- 7

1.50

.-iSF^li?

>a*oo

S!) 1279-1

IB. 00

505434

7,50

SB I486

22,85

SET 2 35*

36.00

St 1279-3

IS.UO

5D14J4-.J

15.00

sdubs-l

26.00

SRF217S

11,00

5B12SI-2

a*M

51) 1434-9

UOfl

sdubs-j

27.00

SRF2572

25,00

SZ-Vldi

10.00

£01439

KOO

SBUM-fl

36.00

SRmfli

40.00

SDW8J-2

ID. 60

SO 1441

1,00

STU^S-l

36.00

5PFJ597

25.00

SD1293-D

10*00

501442

2i,0JJ

SM511H3

75.00

BRF274]

40.00

BU 1233-4

JLI.UJ

£01444

25.00

3D 1520.-2

1B.0O

SRF2747

40.00

SDlZS^l

.5. DO

S0!4iiu-H

IS.OQ

SU1522-4

13. QO

5Rt'2767H

40.00

SEiS90-4

15.00

S01444-9

La. oo

BU1528-1

&4.M

5RF2S21

25.00

S&1290-7

1J,D0

301446

21,00

SU Id 2ft- 3

J4.W

RRF2A22/2W$t03

PrW

501300

U25

SDU$Q-1

2L.00

HBlHO-2

10. 00

SRF2SS7

20,00

5BJ 301-7

SOHSi

6064

21.00

£01536-1

41.00

SRt-2917

ii*no

IS, 00

SB 15 3911

1QQ.00

£EF291a

15.00

2aron

SDi542Hl

170.00

SRF2919

15.00

24. OD

301 54h

2fc.00

SltP3071PF

50,00

24. 00

SO 1545

33.00

S 54006

25,00

L2.00

SB1546H1

55.00

554152.

.5,00

L5*CW1

BD1561

79.00

TA76S6

li. DO

L4.90

SD3574-]

6,95

TAB559

15,00

L5.00

SM575

fcS$

TAB561

15.00

12.00

SP45S7

25.00

TAB 562

15,00

LS.M

:-.K !M4h

5.00

TA8563

15,00

20*00

5L5D1-59

15.00

TA8564

13,00

23. Ml

SL50 1-173

15.00

TAB394

15. DO

2B.O0

5M7714

5,00

TTSlfi?

J, 55

26. 00

BHI-U2

(5.00

TP313

2.50

5-6.00

SRrS95

50.00

TP1D14

5.00

15,00

SKF750

36.00

TP102S

15.00

3.35

SRF769U

20.00

TSU3

5.00

3.25

£RfB87R3

2,50

IXVF2201/HF

45O.O0

3.25

SRF^$9K

L5.00

V 22 2-2

2-i.JM

4*03

SRF1005

50.00

vMurr

20.00

23.00

snrioia

5.00

V4L5

5.00

15.00

SUFI 07 4

50,00

Relays

BNC To Banana Plug Coax Gable RG-58 36 Inch or BNC to N Coax Cable RG-58 36 inch.

S7.99 or 2 For $13.99 or 10 For $50.00

$8.99 or 2 For $15.99 or 10 For $60.00

Am phenol

Part # 316- 10102-8

U5Vac Type BNC DC to 3 GHjs.

S29.99

COAXIAL RELAY SWITCHES S?DT

FXR

Part & 300-11182

120Vae Type BNC DC to 4 GH?,.

FSK 5985-543-1225

$39*99

FXR

Part # 300-11173
120Vac Type BNC Same
FSN 59S5-543-1S50

$39.99

TERMS. DOMESTIC. Pr»p»nJ, CO.Q. Of &*dM Card

POflHICN ' Prepaid nn»v, M.S. Funds. Monay Order, or Cashier's Check Only.

C.O.D.' Acc+spsatilft &y I*1sph4>ri* flf m4li. Payrneni Trnm cuBldmer will be by Cash. Mortay 0«ter, &r Caahief'B- Chec«. Wa are awry
thM ws cannol wc^pt parson*! «h»cKS rcrt CO CS.'S. C.O.O.'fi are shipped by air only and th.u tlnltafl Parqal 0»rvlce

CONFIRMING OftDEFtS; Wt WfOuid prdo< thai conlnrmmg ordaca not be sent aflat a. talephone order hat bean placed H company
poltry i*ec*fleHalBS a conhrmlng order, pfftasa mart, ',CON!FIR^t|NG,, boldly on ths c^dar H proolamE or duplicate ehlpmanta w-
cw due 1o an ordef *hich la ftjit propartj m*^*ri, ihu cuslcmei- will be told reaponKlDle <or any chargaa Incurred, plus a 1S%
resliH h. charge on the reEurned p*cia

CREDIT CAflDS We are «« «*sp(insj MASTERCARD, VISA, AND AMERICAN EXPRESS

DATA SHEETS: Wh*sn iM*> Mav* data wheels in srock on dav^ces we will Bupcriy |hem with the order.

DEFECTIVE MATERIALS: Ail Claims Tw derive r^atonalE. musl be made within 3D DAYS after receHpl ai the parcal. All claima
mual i"K:lude lha datottlv* ntatertal (ro* sealntg purpci&es-l, a copy at our invoice, and a return authorization number which must 04
obtained prior lo shipjjinn |hn mercfand^sa back tc u&. Thia can be obtained bv celling |RD2:- I42JS16 or pending, u* e poftte*>rd.
Due ig Manual riurti' ^^-rra^lles we are unable tc rapiace ex i&aue credit on hems which hava bean addend to Or have P4an
altered In anf wajf All relum Itami m«M be tracked properly or il wilt void ail wananEcaa We do not aaeume reeponaibllllv tat ahlp
ping and handling elwo*fl memred.

DELIVEATl Ordare at$ gauallv Shipped [he same day they are placed or Ihe next buaineae day, umaaa we are oui of eloch on an
Item Tha cu&tomet will b^ n^|ili(jd by posi card If we are going to bacXorder the Item. Our normal shipping mtfhod it UP55 4F U-S-
Ma>l depending on size or I ha weight of the package. Test Equipment ,a sriipped only by air and la freight collect, unl*aa peloc
arranoemants nave been mad* ar>d ^pfVov*4.

FOREIGN ORDERS: AH foreign ordana muat be prepaid with * C&aniftr'a Check, or Moray Order mode out in LU0. FUNDS ONLY.
Wv «r*j sorry hu1 C.O.D. is. ncl available to loralgn coutitrffts .and Idlers pf credll are una&ceptabla as a form of payment. Further
information .£ availaPle on requea-t

HOURS: Mtuioay triru Frioay 3:30 am lo 6:00 pjm. Saturday*. B:3Q am io 4^0 cvm

tNSURAHCE: Pl&sa* ihCliXlt £5* for eac^h addK-onal SlOG.Od over tlOO.QO, UPS ONILY. All jnturtd packagw ate flhlppod thm UPS
only. Il you wish to havti il shipped through (he peat oMloe thare la a f5 ,00 Tea wnlch la addltlontt ia Ihn Ahippiny. handling and 'n-
eurence.

Of EN ACCOUNTS: We regret that wa dc not isaua open ^ccounSe.

ORDER FORMS: Naw o?der forms are Included with Mch ordet Tor your convemBnca Additional older lo*ma are available an
t+Kuest.

PARTS: We reserve the right lo substitute or replace any item with a part of equal ex comparable
specification.

POSTAGE: Minimum snipping and handling Ht the U.S., Canada, and Mexico is $3 .00 for ground ship-
ments, all Qthe* count* las fs $5,50. Air rates are available at the time of your Ofder. A-ll foreign orders
please include- 25% of the ordered amount for shipping and handling, COVD.'s are shipped A1R
ONLY.

PREPAID ORDERS: Orders must be accompanied by a check.

PHICESr Prices are subject to change without notlce.

PURCHASE ORDERS; We accept purchase Orders only when I hey are accompanied by a check.

RESTOCK CHARGES; If parts are relumed Id MHZ ELECTRONICS, INC, due to customer error, the

customer will be held responsible for all fees incurred and will be charged a 15% RESTOCK
CHARGE with the remainder in ORE DFT ONLY. The following must accompany any return; A copy of
our Invoice, return authorization number which, must be obtained prior to shipping the merchandise
back. Returns must be done within 10 DAYS ot receipt ot parcel. Pel urn authorization numbers can
be obtained by calling (602) 242-8916 or notifying us by post card. Return authorizations will not be
given out on Our 800 number.

SALES TAX; ARIZONA residents must add G% sales tax. unless a signed ARIZONA resale lax card

Is currently on file with us. All orders placed by persons outside of ARIZONA, but delivered lo per-
sons in ARIZONA are subject to the &% sales tax,

SHORTAGE OR DAMAGE: All claims for shortages or damages must be made within 5 DAYS of
receipt of parcel, Claims must include a copy of our Invoice, along with a return authorization
number which can be obtained by contacting us at {602] 242-9918 Of sending a post card. Authoriza-
tions cannot be on our BOO number. All Hems must be properly packed, if Items are not properly
packed make sure to contact the carrier so that they can come out and inspect the package before
Ills returned to us. Customers which do not notify us within this time period will be held responsible
for the entire order as we will consider the order complete.

OUR BOO NUM8ER IS STRICTLY FOP ORDERS ONLY (BOO) 52B-01S0. INFORMATION CALLS ARE
TAKEN ON (602) 242-6916 or (602) 242^3037.

2111 W. CAMELBACK ROAD
PHOENIX, ARIZONA 8501 5

master cftarge

Tfwtawrwj^^

ectrof|icj|

"All parts may be new or
surplus, and parts may be
substituted with comparable parts
ff we are out of stock of an item.1'

For information call: (602) 242-3037

Toll Free Number
800-528-0180
(For orders only)

PRICES SUBJECT TO CHANGE WITHOUT NOTICE

106 73 Magazine • November, 1984

Amateur Radiate
Technical Journal

Mr-rfn-M-

Bflf I I

ftmiTJftg I

BACK ISSUES

1977 to June 1980 .
July 1980 to present

> $3,00 ea
. S3. 50 ea

Add $1,00 per magazine for
shipping, 10 or more back is-
sues add $7.50 per order for
shipping.

Write for your copy today!

73; Amateur Radio's
Technical Journal

Back Issue Order Dept.
80 Pine Street
Peterborough, NH 03458

ATTENTION

Foreign Computer Stores/
Magazine Dealers

You have a large technical audi-
ence that speaks English and is in
need of the kind of microcomputer
information that CW/ Peterborough
provides.

Provide your audience with the
magazine they need and make
money at the same time. For details
on selling Microcomputing, 80
MICRO, inCider, HOT CoCo,
RUN contact:

SANDRA JOSEPH

WORLD WIDE MEDIA

386 PARK AVE,, SOUTH

NEW YORK, NY 10016

PHONE (212) 686-1520

TELEX— 620430

NEW!

Special North
American Edition

As an added bonus, the 1985 U.S. CaJIbook
also lists the amateurs in Canada and Mexico!
You get the complete and accurate U.S.
listings (prepared by our own editorial staff),
all the usual up-to-date CaHbook charts and
tables, PLUS Canada and Mexico. Now that's
real value"

The best just got better!

Of course, Canadian and Mexican amateurs
are also listed in the 1985 Foreign Call book.
Don't delay! The great new 1985 Callbacks
will be published December 1, 1984, Order
your copies now for earliest delivery.

Each Shipping Total

DU.S, Callbook $21.95 $3.05 $25.00

D Foreign Callbook 20.95 3.05 24.00

Order both books at the same time for
$45.00 Including shipping within the USA,

Order from your dealer or directly from the
publisher. Foreign residents add $4.55 for
shipping. Illinois residents add 6% sales tax.

Keep your 1985 Callboaks up to date.

The U.S. and Foreign Supplements contain
all activity for the previous three months
including new licenses. Available from the
publisher In sets of three (March 1, June 1,
and September 1) for onty $15.00 per set
including shipping. Specify U.S. or Foreign
Supplements when ordering. Illinois res-
idents add 6% sales tax. Offer void after
November 1, 1985.

RADIO AMATEUR III I

callbook inc

^^ Dept. B

925 Sberwood Dr., Box 247
Lake Bluff, ||_ 60G44* USA

>ei Tel: (312} 234-6600

■flimrL

.iWCixdj

Electronics Supply

1508 McKinney

Houston, fexas 77010

Call for Quotes

713-668-0268

ClOSEOUT CORNER- SOME GOOD DEALS IN MERE
W© plan to feature things we ^uncf "n our ware-
house. W you ever saw the warehouse you would

understand! This months '"FINDS" are:

AEA MT-1 Morse Trainer .,,25.00

AEA MT-1P as above with nlcad battery 50,00

AEA KT-1 KeyeifTralner 25

DRAKE P-75 fbwer Supply 100 .

DRAKE 550 Cade Reader 30000

DRAKE TR7/R7 RX Cable 2G.QQ

HAL ST-5000H TU 1a5 00

n " L \* \~£ I vkJ klhlllriillM ■■ > i ■ ttiiiiiiiii II I I Y II b H- 1 1 1 ■ I I ■ ■ I ■ 1 iyY/ <- J>\J

HALDS310Q , 1OTGG

NOTE - QUANTITIES ARE VERY LIMITED
USED GEAR - YOU BETl CALL FOR UP TO THE MINUTE
ITEMS AND PRICES. 90 DAY WARRANTY, SALES PRICE
REFUNDED WITHIN TWO WEEKS, SIX MONTH FULL
TRADE IN TOWARDS NEW GEAR

SPEClAilil! SPEOALIIH SPECIALHII

CALRAD 65-287 SWR/RELATIVE POWER MET '•

ONLY

DAWIA CN620B POWER/SWR METER mpQ

SOMETHING Nf W FROM AEA

By the time this ad hits the stands AEA wilt have
something new at the store:

MBA-TOR now for the VK>2Q .99-95

SWLTEXT tor the C-64 and VlC-20 .99-96

TM tuning indicator —99 ■■

PKT-1 Racket unit .. , > -A99 ,

Watch the magazines for details In the AEA ads

WOASE SPECIAL Is tne highly acclaimed CfM with

fne new MBA-1UR software a high performance

package for the more serious operator.

AEA CM TU retail

AEA MBA-TOR Software for C-64 retail

AEA TM Tuning Indicator retail

One Vile Connector 4 or 6 pin retail

5 ft Belden Mic Cable retail

239.96

119.95

4,9ft
5.Q0

TOTAL $489.80
PACKAGE SPECIAL! $3*9,95 YOU WE t$S

EQUIPMENT

As you know, Madison Is an authorized dealer

for ail the popular equipment lines such as:
D12AKE, KENWOOD, YAESU, ICCM KDK, TENTEC
SANTEC etc, BE SURE TO CALL US FOR A PRICE
BEFORE YOU MAKE ANY EQUIPMENT PURCHASE.
WE WOULD LIKE YOU TO BE OUR CUSTOMER,
. FM4033 NEW 220mhz J49 30

tT-L'" r I VI £-\j Ou n*i(Mii»t(i«ii»i" ► J- O t iYu

$ANTEC ST142 r.. + + FREE GOODS + + ...299.96

SANTEC ST440up ■„ 25G

KIMWOOD TTC26QG „<... *,Sive us a ring

TENTIC 2591

■ 4 t ■ ■ 1 Mil II I h ■ ■ I ■■<■■■ ■■

, , . . - , ■ .

,,.,,269.00

ICOM iC-02AT , ; Talk to us

TOKYO Ml POWER amps fess 45%

MIRAGE amps .^. ...Jess 12%

VOCOMM amps .....Less 10%

TOKYO Hi PPWES HC2000 tuner 269 96

TOKYO HI POWER HC4O0L tuner 129.95

TOKYO Hi POWER HC200 tuner... 69 95

DRAKE MN75 *2S,0Q

WM. NYt MB V 3KW tuner & ant swltch489.O0
WM NYE 46-6 phone patch

for ICOM [8 wire],,,.. ....S2.QQ

BEARCAT DX-1000 .;... 499,9§

SIGNAL ONE MMJSPEC )030 6295,00

ACCESSORIES AVAILABLE CALL

BOOKS— We stock a wide selection of books on
Mcttonlct, Communications and Computer*.

DON'S CORNER
Well, I jusl oame bock from the Shreveporl la. Hamtest.
[August 11 & 12}. I touched for the results of the volunteer
exams given during the Hamfe&t. Boy the pass rate was low
Probably the worst I have ever seen. The problem appears
to be the lack of study materials for the testing. Remember
that the BASH BOOKS ore goad tor the FCC exams but not
far (he V.E. Program, For the V.£. tests used the AMI study
guide or me Ameco License guides.. Good luck on the
upgrade 73 for now.

1-600-231-3057

^ See List of Advertisers on page 38

73 Magazine * November, 1984 107

THE MOST AFFORDABLE

REPEATER

ALSO HAS THE MOST IMPRESSIVE
PERFORMANCE FEATURES

(AND GfVES THEM TO YOU AS STANDARD EQUIPMENT!)

•Qm Ironies

RfPlOO ftSPCArFfl

JUST LOOK AT THESE PRICES!

Band

Kit

Wired/Tested

10M,6M,2M,220
440

$680 $880

$780 $930

Both kit and wired units are complete with ait parts, modules, hardware, and crystals.

CALL OR WRITE FOR COMPLETE DETAILS,

Also etvailabie for remote site Unking, crossband, and remote base.

FEATURES:

■ SENSITIVITY SECOND TO NONE; TYPICALLY
0.1 5 uV ON VHF, 0,3 uV ON UHF.

• SELECTIVITY THAT CANT BE BEAT! BOTH

8 POLE CRYSTAL FILTER & CERAMIC FILTER FOR
GREATER THAN 100 dB AT ± 12KHZ. HELICAL
RESONATOR FRONT ENDS. SEE R144, R220,
AND R461 SPECS IN RECEIVER AD BELOW-

• OTHER GREAT RECEIVER FEATURES: FLUTTER-
PROOF SQUELCH, AFC TO COMPENSATE FOR
OFF-FREQ TRANSMITTERS, SEPARATE LOCAL
SPEAKER AMPLIFIER & CONTROL.

• CLEAN, EASY TUNE TRANSMITTER; UP TO 20 WATTS OUT
{UP TO SOW WITH OPTIONAL PA).

HIGH QUALITY MODULES FOR
REPEATERS, LINKS, TELEMETRY, ETC

HIGH-PERFORMANCE
RECEIVER MODULES

R144 Shown

• R144/R220FMRCVRSfor2Mor220MHz,
0.1 5uV sens.; 8 pole xtal filters ceramic filter
in i-f, helical resonator front end for exceptional
selectivity, more than -1 00 dB at ±12 kHz,
best available today. Flutter-proof squelch.
AFC tracks drifting xmtrs. Xtal oven avail.
Kit only S 138.

• R451 FM RCVR Same butforuhf. Tuned line
front end, 0,3 uV sens. Kit only $133.

• R76 FM RCVR for 10Mf 6M, 2M, 220, or
com mercial bands. As above, but w/o AFC or
hel. res. Kits only $1 18.

Also avail w/4 pole fifter, only $BB/m.

• R1 10VHF AM RECEIVER kitforVHF aircraft
band or ham bands. Only $98.

• R1 10-259 SPACE SHUTTLE RECEIVER,
kit only $98,

amironics

TRANSMITTERS

* T51 VHF FM EXCITER for 10M, 6M< 2M,
220 MHz or adjacent bands. 2 Watts contin-
uous, up to 2Va W intermittent. $63/kit.

'*fc'&&4

^* **# ^

T451 UHF FM EXCITER 2 to 3 Watts on 450
ham band or adjacent freq. Kit only $76.

VHF & UHF LINEAR AMPLIFIERS. Use on
either FM or SSS. Power levels from 10 to 45
Watts to go with exciters & xmtg converters.
Several models. Kits from $78.

A1 6 RF TIGHT BOX Deep drawn alum, case
wf t h tig ht cove r a n d no seam s. 7 x 8 x 2 i nch es,
Designed especially for repeaters. $20.

i-33

ACCESSORIES

i* 4r

HELICAL RESONATOR FILTERS available

separately on peb w/connectors.

HRF-144 for 1 43-1 50 MHz $38
HRF-220 for 213-233 MHz $38
HRF-432 for 420-450 MHz $48

COR -2 KIT With audio mixer, local speaker
amplifier, tail & time-out timers. Only $38.

C0R*3 KIT as above, but with "courtesy
beep". Only $58.

CWID KITS 158 bits, field programmable,
clean audio, rugged TTL logic. Kit only $68.

DTMF DECODER/CONTROLLER KITS,
Control 2 separate on/off functions with
touchtones*, e.g., repeater and autopatch.
Use with main or aux. receiver or wtth Auto-
patch. Only $90

AUTOPATCH KITS* Provide repeaterauto*
patch, reverse patch, phone line remote
control of repeater, secondary control via
repeater receiver, Many other features.
Only $90. Requires DTMF Module.

NEW - SIMPLEX AUTOPATCH

Use with any transceiver. System includes
DTMF & Autopatch modules above and new
Timing module to provide simplex autopatch
and reverse autopatch, Complete patch
system onfy$200/kiL Call or write for details.

NEW LOW-NOISE PREAMPS RECEIVING CONVERTERS TRANSMIT CONVERTERS

i i f?| Hamtronics Breaks
f the Price Barrier!

No Need to Pay S80 to 5 1 25

for a GaAs FET Preamp.

FEATURES:

•Very Low Noise: 0.7 dB VHF, 0.8 dB UHF

• High Gain: 1 8 to 28 dB, Depending on Freq-

• Wide Dynamic Range for Overload Resistance

• Latest Dual-gate GaAs FETP Stable Over Wide
Range of Conditions

• Rugged. Diode-protected Transistors

• Easy to Tune

• Operates on Standard 12 to 1 4 Vdc Supply

• Can be Tower Mounted

MODEL

LNG-28

LNG-50
LNG-144
LNG-220
LNG-432

LNG-40
LNG-t&O

TUNES RANGE PRICE

26-30 MHz S49

46-56 MHz S49

137-150 MHz S49

210230 MHz $49

400-470 MHz $49

30-4© MHz $64

150-172 MHz S64

ECONOMY PREAMPS

Our traditional preamps, proven in years of
service. Over 20,000 in use throughout the
world. Tuneable over narrow range. Specify
exact free?, band needed. Gain 1 6*20 dB. NF =
2 dB or less, VHF units available 27 to 300 MHz.
UHF units available 300 to 650 MHz,

P30K, VHF Kit less case
P30W, VHF Wired/Tested
P432K, UHF Kit Jess case
P432W. UHF Wired/Tested

518
S33
$21
$36

HELICAL RESONATOR
PREAMPS

Our lab has developed a new line of low-noise
receiver preamps with helical resonator filters
built in. The combination of a low noise amplifier
and the sharp selectivity of a 3 or 4 section
helical resonator provides increased sensitivity
while reducing intermod and cross- band inter-
ference in critical applications. See selectivity
curves at right. Gain = approx.12 dB.

Model

HRA-144
HRA-220
HRA-432
HRA-i )
HRA-O

Tuning Range

143-150 MHz
213*233 MHz
420-450 MHz
150-174MHz
450*470 MHz

Price

S49
$49

$59
$69
S79

Models to cover every practical rt & if range to
listen to SSB, FM. ATV, etc, NF = 2 dB or less.

VHF MODELS

Kit with Case $49
Less Case S3 9
Wired S69

Antenna
input Range

50-52

50-54
144-146
145-147
144-144.4
146-14*
144-148
220-222
220-224
222-226
220-224
£22-224

Receiver
Output

144-146
25-30

144-146
26-30
26-30

27-27.4
26-30
50-54

28*30
144 148
T44-148

50-54

28-30

UHF MODELS

Kit with Case $59
Less Case $49
Wired S75

432-434
435-437
432-436
432-436
439-2 5

28-30
28-30
144-148
50-54
61.25

SCANNER CONVERTERS Copy 72-76, 135-
1 44t 240-270, 400-420, or 806-894 MHz bands
on any scanner. Wired/tested Only $88*

SAVE A BUNDLE ON
VHF FM TRANSCEIVERS!

FM-5 PC Board Kit - ONLY $1 78

complete with controls, heatsink, etc,
10 Watts, 5 Channels, for 2M or 220 MHz.

• ■ * a

Cabinet Kiit complete
with speaker, knobs,
connectors, hardware.
Only S60.

While supply
lasts, get $60
cabinet kit free when
you buy an FM-5 Transceiver kit.
Where else can you get a complete transceiver
tor only S17B

For SSBP CWt ATV, FMP etc. Why pay big
bucks for a multi mode rig for each band? Can
be Jinked with receive convertersfortransceive,
2 Watts output vhft 1 Watt uhL

For VHF,
Model XV2
Kit $79
Wired $149
(Specify band)

Exciter
Input Range

28-30

28-29

28-30
27-27.4

28-30

50-54
144-146

Antenna
Output

144-146
145-146

50-52

144-144 4

220-222*

220-224

50-52
144-146

28-30

For UHFt

Model XV4
Kit S99
Wired S 169

28-30
28-30
50^54
61.25
144-148

432-434
435-437
432-436
439.25
432-436*

-Add $20 tor 2M input

JS^T^*

**€

VHF & UHF LINEAR AMPLIFIERS. Use with

above. Power levels from 10 to 45 Watts.
Several models, kits from $78.

LOOK AT THESE
ATTRACTIVE CURVES!

Typical Selectivity Curves

of Receivers etnd

Heitcat Resonators.

IMPORTANT REASONS WHY
YOU SHOULD BUY FROM THE
VALUE LEADER:

7, Largest selection of vhf and uhf kits
in the world.

2. Exceptional quality and tow prices dye
to large volume.

3 Fast delivery, most Hits shipped same day.

4. Complete, professional instruction
manuals.

5. Prompt factory service available and
free phone consultation

6. In business 2 1 years

7. Self more repeater modules than all
other mtrs- and have for years. Can give
quality features for much fower cost

Call or Write for FREE CATALOG

(Send S1 .00 or 4 IRC'c for overseas mailing)
Order by phone or mail • AddS3S& H per order
(Electronic answering service evenings & weekends)
Use VISA, MASTERCARD, Check, or UPS COD.

miromcs, inc.

65- D MOUL RD. • HILTON NY 14468
Phone: 716-392-9430

Hamtronics ' is a registered trademark

^ See List of Acfveni$9n on page 88

73 Magazine * November, 1984 109

DEALER
DIRECTORY

Culver City CA I .tvonia MI

|uh'i I- Itxfmni^, 3&HB Sepulvi*!* Blvd., Culver OMnftate pruiluvxilraK: ^m. AmatettJ nidlo.
*:ity CA 90230, 300-ftMH. '! TVtb ifl3J&Hfl Son repe»ter. uttdliti?, and compute* appUottiona]
Dii-L'i ..>QT S732 (Rtmn N' Call Pltil WDKAIIO Enwwi tttotiwoltafas,

276*10 Schunk-raft Rood. Livonia MI 48 ISO*

523-1850.

San Jroe CA

&i\ ansa newest anuirm rarik) Owe, N*-*
& used amairur r»k«> taks At wtvicr. V\Y
lratun> Esmmd. [COM A Aim. Yvai. TW
Tw, Santa1 h. mm\\ mnrr. Shatrr ftad>t>. Lnt..
I77SA 5- Wiixrwtfcr Bl«d.* Campbell CA
tmaVSlMML

Frniiarw CIA

GlMtffaf Uott tCOM. DrtiTrnn. Ten-Tefr,

Mirjief-. Cubic, LllftRT, QVffi •HKK1 clyctrnnic
products Fot hohhyiit, ii^'Jiiiicmrj, expc?l
iiitiiiL-r. Alsu CH milk*. Inndmobtle, Fontana
Electronic!. 8828 SJrrra A\*\, I'nnlann < !A
9*315. S22-77I1I

New Code I>K

Facftay Airlhnrurti Dritv-r ' Yanu, ICOM. Tm
Tmt. KPk Ken**™! AKA, ILantmas^ Santa.
Kuli lif»* ill acTT^mn \if nil pj IMam a :e

One milt off 1-95 Driawaie Amateur Supple .
71 ModD* Road. Nn t'^HfeT DE 1ST30,

Lincoln NF

CaYC! <tommun*cabons fc a fulUinr diffnbufnr
of hmjpm III-*- ajuatiruj equipment and
ran. intrnna*. and *>♦ rvthing- 4S3f
w. I ^nfa. \E GSS04. 4C-RADIO

DemNH

S*tvmn thr iwtti etmnmuinty *itJi or* and u»d
njulfiriM'ti.i %V'r stcml itid imit* nam niajoi
lm»: AKA, A-vimn. Azden, BfcW, CwJx-raJl,
Hy^Cain, Hinder ICOM. Kmwood, KIM.
I.uiw-n, Miragi\ Mosley; book*, rotors, ruble
and QOjtfWCtOTft, itii5int55 hour* *» 7 Monday
ilitriiiiili Thorsduy. and fl-3 Iridny and Satur-
t\u) IHvntdell, OH Warner Hill Knad. Ifcrry Nil
IXUTJ*: It t-Tr 171.

Albany* New York
UPSTATE NEW YORK

krfi*«*i, ICOM Tea-Tec, Brtdni. (.itOvrarf.
Urw, Hwrif-r. ARBU ffy-Caai, fl&VV . MP J.
Mirage New and lbbJ rt{ui{i*Ttrnt Sttmhij rhe
*mitn:r cutnnujiiirt uncr 1942 Adirondack
Ekctrenkv Inc. 1991 Central Avenar, AJtwrv
tff ttam. 45&4MS fow maV *al ol Nwt!i« -v

Preston ID

Nov ttHTBYZ hu the l«M dock ol uiutmr
gear in riV ln(rrTiioiiii(aui Wert and 6W bed
prion* Call nir fur all ynut hum nerd*.. R^kb
iXvirihuring, 7N Sti. Stale, I'refrori ID 83263,

I .iuliion MA

The nHiabie ham slmr *ervii]f NE. Fid! liur *»f
I CUM & fcfnitouad Vmsm HTv Drake, Daiwa.
BfcW aeeeamsriH Cttrti * True fce%vn. tapa,

Huillrf. Tclrft Hv -C«m product- Mirac*-
jjnrfi . Asrmn F^ , Alpha MHta prttiinn,
ABHI. A kintnnvKT. inatrmllnn aids Whiitirt
taiiar drteiinn. Knit 1 1 lie of eoax fitting
TEL- COM KkHrmit CwiujiuImij. 67S
Ciaal fl«L {Hi. 119). I ittlrtim MA 01 460.
4S6-^UK)3040

Columbus OH

Thr Iniu;i4i arhl bwt hani tinn- tn a ■ ■*- Mktoeal
(I'aiurnikj Unmmid and ntrwir ^waln |.-i.hIik^
rt-rl]i ^iitkltmdi'.]llilV^ WeSftJl Ofllv thr tn-1 Aii
tfioii/t^d K^nw-iWMl service. Univenal Anmluur
Rldla, InCt, l^«u Aida Dr„ Bcyn*»lftibur^ Ko-
IiiiiiIhik) Oil 420KH. SCi(,-4E!(>7.

DaUas TX

IBM PC XT kit>. supplies. exctaitMoit prtnl-
uceu vktw tratorrr lefts for pay TV. CATV.
^it4]iTr huhbv'utsr eiectrotue pru(«n V
nfi4n. Mcift* ilian **XV> parts in rtixk irmicoo-
ductOia, IC*. discttft*na vidru a*Tr»<.ri«,
touk. aodko, aafnc»tT?e. rahanrei, enrnputrr
penpberaft Plraar wn*e for ymtt frve W-pafgc
rataloc Sabet l-Jeprmnic^ 11650 fiend Kd
S*e. 104. Dalla* TX 71243; 783-4B60 dnrmrHy

i r.|,

DEALERS

Yijut company name and message
can contain up to 25 words for as
little as $150 yearly (prepaid), or
5 15 per month (prepaid quarterly).
No mention of mall-order business
or area code permitted. Directory lest
and payment must reach us 60 days in
advance of publication. For example,
advertising for the December "84 issue
must be in our hands by October 1st.
Mail to 73 Magazine. Peterborough
Mi 00458. ATTN \ane> ■ Ciampa."

PROPAGATION

Jim Gray W1XU
73 Staff

EASTERN

UNITED STATES

: TO

■

GMT: oo o? 04 oa ob io iz u is to so ±2

AlASKA

;"'"'

ARGENTINA

2fl

J.0A

20A

AUSTRALIA

40A

CANAL £ONE

AOA

40A

■'.0

20A

i SA

.•■A

ENGLAND

20A

HAWAII

w f*Hi^ '^^

JAPAN

*''

;

1 S 1 1 s

4 j 1 A J

Ht^L A *Vp u

- '.'

-.-

?:^

1 3A 20a 1 20

PHILHflNES

:■

menTo ftico

- ',

20A

]">h

! M . 1

20 J40A

SOUTH Af flICA

40A

,,; :

ISA

20A 20A

20A

ULLS.lt

■

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WEST COAST

^1A

I5A|i5A

CENTRAL UNITED STATES TO:

ALASKA

AffGliNlllVA

40 J

•,i"i

I'.A

20A

AUSTRALIA

CANAL ZONE

r. 0 ;

pi''

irJA

ISA

! '.A

ENGLAND

I'll A

HAWAtl

2fl

■ NOra

MMM

MEXICO

*oUr.

ISA

15A

Philippines ]2QaJ 20

PUERTO RICO

-* |

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l^A

ISA

SOUTH AFRICA

I^A

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US 5 R

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WESTERt

J UNITED STATES TO:

ALASKA

20A

40A 20

20A

AHGENTINA

20A

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15a

Atl^THAI IA

2fTA

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ISA

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ENGLAND

20A

HAWAII

20A

404

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INDIA

2SW

20A

JAFAN

20A

40A

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MEXICO

:••«

40A

20A

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PHILIPPINES

■-

PUt ft TO RICO

..',.■.

40A

20A

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ISA

SOUTH AFRICA

: .

U. 1. S. ft.

20A

EAST COAST

15A

ISA

A = Next higher frequency may also be useful.
B = Difficult circuit this period.

G = Good, F = Fair, P = Poor.

SUN

MQN

NOVEMBER

TUB WED THU

SAT

■ — ■ ■

1 G

2 0

4 !

5 6

F F

7 8

G G/F

9 M

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12 c13 n

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17 ft

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20 ci21 .

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29 „

30 „

1 10 73 Magazine • November, 1 984

THE FIRST NAME I
ELECTRONIC TEST GEAR

20 MHz DUAL TRACE OSCILLOSCOPE

Unsurpassed qualily at an* u-nbeatable price, I he Ramsey oscillo-
scope compares to others costing hundreds more. Features include
a component testing curcuil for restate/, capacitor, digital circuit and
diode testing. * TV video sync filter ■ wide ftandwidlh & high sensi-
tivity ■ internal graticule * front panel trace roial-or * 2. axis • high
sensitivity x*y mode * regulated power supply * built-in calibrator

■ rock selid triggering

$39995

high quality hook On
probes incFiided

45 MHz DUAL SWEEP OSCILLOSCOPE

Tht; Ramsey 625 jsa dual tune base, aeiayixi s^veep unit that inducies^ bLiiK-4#i
signal flefay Imo lo fHJWit desr ii&wng curing very snon rise limes ftf nigh fre-
ciu&ncy waverofrr>£ Other resrures include, wriabio Irtofijw hosooci * 20 cali-
brated &w*ep 1irn& lances irc-m 15 5 a/drv Ic 0.2 .uS/div ■ tuHy adjustable &w&.a
llrrifl ■ X&sw&cp magrifitaiion ■ tivelngg&r sources: CH 1 . CH2. LINE External
and iNTernai iV mode) * Jrcmt pan&i^-y operation, Z axis incut » sum d liter-
ence oP CHI, and CH2 WaveFormidpSplay&tf as single trace * Sweep gate and
iwfrBU output • autcj taCLisa ■ 5irg.lL' swut'p

S79995

high qualily hook on
probes included

RAMSEY D-1 100
VOM MULTITESTER

Compact and reliable, designed lo
service a wide variety of equipment.
Fea Eyrea include ■ mirror back
scale * doubie-reweted precision
moving coil * double overload pro-
tection * an ideal low cost unit for
the Dep/nner or as. a spare back-up
unit.

'f » 3 '

$1995

test leads and
battery Included

NEW RAMSEY 1200
VOM MULTITESTER

Check transistors, diodes and
lEDs with mis professional quality
meter. Other (eaiures include;
decibel scale * 20K volt melering
System * 3 %" mirrored scale *
polarity switch + ?Q ruea&urmg
ranges. * safely probes "high
impact plastic case

$2495

teal leads and
battery Included

RAMSEY D-3100
DIGITAL MULTIMETER

Reliable, accurate digital mea-
surements at an amazingly lo*
cosl • in-fine color coded push
&ulton&, speeds range selection
• aos plastic I ill standi * recessed
inpuljac^s ■ overload protection
on all ranges • 3!A digil LCD dis-
play wit!; auto zero, auto polarity
& low BAT indicator

95 lest leads and

battery included

$49

«*TO TTTT m

CT-70 7 DIGIT 525 MHz
COUNTER

Lab quality at a breaktruougrt price. Features

• 3 frequency ranges each with pre amp * dual
selectable gale limes * gate ^cliuity indicator

* SOrnV @M$0 MH2 typjeal sensituvity * wide
frequency range » 1 ppm accuracy

*1 1 995

CT-70 kit $99.95

BP-4 nicad pack ft.95

■1

Ci«-oSt*r^

^jaSjjS^^j^SB^JSS

CT-90 9 DIGIT GOO MHz
COUNTER

The most versatile for -loss lhan $300. Features 3
selectable gate times » 9 digits * sate indicator
» display hold ■ 35m V @ 150 MHz typical sen-
sttmty • 10 MHz timebass for WWV calibration

wired includes
AC adapter

i ppm accuracy

$149»5

CT-9Q kil „

OV-l 0 1 PPM oven timebase
6 P-4 nicad pack

wired includes
AC adapter

$129.95
..59.95

. . B.95

. 0 c t 6 S

muid ' ***** m^\

CT-125 9 0IGIT1.2GHZ
COUNTER

A 9 dfgrt counldf thai will outperform units cost-
ing hundreds more. • gate inoicator * 24m V @
150 MHz typical sensitivity * 9 digit display
* 1 ppm accuracy • display hold • dual inputs
with preamps

S16995

wired Includes
AC adapter

SP-4 mead pack , r8.95

rittit, ■"— ~1W HHPTM

fT-5f! iHtourhcv cog^rrB

fvnsft il-i.mriH*

CT-50 8 DIGIT GOO MHz
COUNTER

A versatile lab bench counter with optional
receive frequency adapter, which lurns the CT-
50 into a digital readout for most any receiver
■ 25 mV @ 150 MHz typical sensitivity * a digit
display • 1 ppm accuracy

«16995

CT-50 kil ,

RA-l receiver adapter kit,

wired

S139.95
14.95

SPQAD6ANU ITF PHEAMPLIHEH

*%&F

■ M : E ;

riliM* ths4«ri*M,

OM-700 DIGITAL MULTIMETER

Precession al quality a I a hobbyist prjee. Fea-
tures include 2Q different ranges and 5 lunc-
lions * 3 'A digit, M inch LED display • auto-
matic decimal placement * automate polarity

$11995

wired includes
AC adapter

PS-2 AUDIO MULTIPLIER

The PS-2 is handy for high resolution audio
resolution measurements, multiplies UP in fre-
quency * great for PL tone measurements
■ multiplies by 10 or 10D ■ 0.01 Hz resolution &.
bu til -i n signal pf eamp/cond 1 1 loner

DM-700kil. 599,95

MP-1 prr>be set 4.95

$4995

PS-2 kit

wired

$39.95

PR-2 COUNTER PREAMP

The PR-B i3 ideal for measuring weak signals
Irom 10 to 1,000 MHz * flat 25 db gain * BNC
connectors ■ great forshifimg RF * itfeal
receiifer/TV preamp

S^L^195 wired includes

^r ^W AC adapter

PR-2 kit .-.,.., $34.95

PS-ID 600 MHz PRESGALER

Extends the range of yOur presenl Counter lo
600 MHz • 2 stage preamp * divide by 10 cir-
cuitry • sensitivity: 25mV @ 150 MHz * BNC
connectors * drives any counter

$5995

wired includes

AC adapter

PS-lBkil $49.95

ACCESSORIES FOR RAMSEY COUNTERS

Telescopic whip antenna — BNC plug .. $8.95
High impedance probe* light loading . . . 16.95

Low pass probe, audio use * 16.95

Direct probe, general purpose use 1 3.95

Tilt bail, for CT-70, 90, 126 3.95

VISA

PHONE ORDERS CALL

716-586-3950

TELEX 466735 RAMSEY Gl

TERMS. * satisfaction guaranteed * examine for ID days: if nul pleased, return in
original form for refund > add 6% lor shipping and Insurance to a maximum ol
£10.00 • overseas add 15% lor surface mail * COD add 52.50 [COD in LISA only]
♦ orders under Si 500 add J I 50 • NY residents add 7% sales lax * 90 day parts
warranty on all kits * 1 year parts S laser warranty on all wired units.

==, = = =,==== t RAMSEY ELECTRONICS, INC.
= S= H#1SeC V 2575 Baird Rd.

-I Penfiefd, N.Y. 14626 ^268

*•* See U$t Of Advertisers on page S3

73 Magazine * November, 1934 111

What To
Look For In A
Phone Patch

The best way to deride
what patch is right for you
is to first deckle what a
patch should do. A patch
should:

* Give complete control to
the mobile, allowing full
break in operation,

• Not interfere with the
normal operation of your
base station. It shoo Ed
not require you to con-
nect and disconnect cab-
les (or flip switches!)
every time you wish to
use your radio as a nor-
mal base station.

■ Not depend on volume or
squelch settings of your
radio. It should work the
same regardless of what
you do with these con*
trots,

■ You should be able to
hear your base station
speaker with the patch
installed. Remember, you
have a base station be-
cause there are mobiles.
ONE OF THEM MIGHT
NEED HELP.

• The patch should have
standard features at
no extra cost. These
should include program-
mable toll restrict (dip
switches), tone or rotary
dialing, programmable
patch and activity
timers, and front panel
indicators of channel and
patch status,

ONLY SMART PATCH
HAS ALL OF THE
ABOVE.

Now Mobile
Operators Can
Enjoy An
Affordable
Personal Phone
Patch. * .

■ Without an expensive
repeater.

■ Using ai*y FM tram-elver
as a base station.

■ The secret is a SIMPLEX
autopatch. The SMART
PATCH.

SMART PATCH
Is Easy To Install

To install SMART PATCH,
connect the multicolored
computer style ribbon cable
to mic audio, receiver
discriminator, PTT, and
power. A modular phone
cord is provided for con-
nection to your phone sys-
tem. Sound simple? . .
IT IS!

implex
Autopatch, there's no waiting

for VOX circuits to drop.
Simply key your transmitter

to take control.

SMART PATCH is all you need to turn your base station into a per*
sonal autopatch, SMART PATCH uses the only operating system
that gives the mobile complete control. Full break-in capability al-
lows the mobile user to actually interrupt the telephone party,
SMART PATCH does not interfere with the normal use of your base
station. SMART PATCH works well with any FM transceiver and pro-
vides switch selectable tone or rotary dialing, toll restrict,
programmable control codes, CW ID and much more.

To Take CONTROL with Smart Patch
- Call 800-327-9956 Ext. 101 today.

^462

How To Use
SMART PATCH

Placing a call is simple
Send your access cod*
from your mobile (exam
pie: *73). This brings v\\
the Patch and you uil
hear dial tone transmittec
from your base station
Since SMART PATCH h
checking about once pe
second to see if you wan
to dial, all you have to d<
is key your transmitter
then dial the phone nttrn
ber. You will now hea
the phone ring and some
one answer, Since the en
hanced control system c
SMART PATCH is con
sfantly checking to see i
you wish to talk, you neei
to simply key your trans
mitter and then talk
That's right, you simp I
key your transmitter i<
interrupt the phone lint
The base station auto
ma tic ally stops transmit
ting after you key you
mic. SMART PATCH doe
not require any specir
tone equipment to con Ire
your base station. It sam
pies very high frequenc
noise present at you
receivers discriminator t
determine if a mobile i
present. No words or sylla
hies are ever lost.

SMART PATCH
Is All You Need
To Automatically
Patch Your Base
Station To Your
Phone Line.

Use SMART PATCH for:

* Mobile (or remote base
to phone tine via Simple
base, (see fig 1.)

* Mobile to Mobile via it
reconnected base sti
tions for extended rang*
(see fig. 2,)

* Telephone line to niobi,
(or remote base).

* SMART PATCH us*
SIMPLEX BASfc SV
TION EQUIPMENT IM
your ordinary base su
lion. SMART PATC
does this without tnte
lering with the norm.
use of your radio.

WARRANTY?

YES. ISO days of wa rrar
ty protection, You simp I
can't go wrong.
An FCC type accept?
coupler is available fe
SMART PATCH.

Communications Electronics Specialties, Inc.

P.O. Box 2930, Winter Park, Florida 32790

Telephone: (305) 645-0474 Or call toll-free (M0)32 7-9956

Theteesu FT-209RH.
5 watts that your

batteries can live with.

Have the power you need when you need it with
"K&esus new 5-watt, 2-meter handheld. Fbwer to
get out in situations where ordinary HTs just won't
make it

\Afe designed our HT with a unique user-
programmable Fbwer Saver that puts the rig to
"sleep" while you're monitoring and "wakes it up"
when the squelch breaks. So you can listen for
hours and still have plenty of power to hit those
hard-to-reach repeaters when you need to.

With the FT-209RH there's no need to fiddle
with knobs when you change from one memory
channe! to another That's because you can inde-
pendently store everything you need in each of
the ten memories: receive frequency standard
or non-standard offset, even tone encode/decode
with an optional module. And then recall any
channel at the touch of a button,

Its easy to hear whats happening on your
favonte repeaters or simplex frequencies. Just
touch a button and scan all memory channels,
or selected ones. Or all frequencies between
any two adjacent memories. Use the priority
feature to return automatical ly to your special
frequency when it becomes active.

Bring up control led-access machines with
the optional plug-in subaudible tone encoder/
decoder; independently programmed from the
keyboard for each channel Listen for tone-
encoded signals on selected channels — without
having to hear a bunch of chatter— by enabling
the decode function,

The FT-209Rhi which covers 10 MHz for
CAP and MARS use, comes complete with a
SOOmAh battery charger and soft case.

For those who want a basic radio without
the bells and whistles, consider the compact
lightweight FT-203R. This economical HT features
25 watts of power and an optional DTMF key-
pad. Most all the accessories for the 209 work
with the 203, including an optional VOX headset
that gives you handsTnee operation that's perfect
for public service events,

So when you visit your dealer let him
know you won't settle for anything but the best
A radio built by ^aesu.

Yaesu Electronics Corporation ^aa

6851 Vttitthall Wiy Remount CA 90723
(213)633-4007

Yaesu Cincinnati Service Center

9070 Gold Ptok Dnve. Hamilton, OH 45011
(513) 974-3100

Prices and sf>ecjfications subject to change without notice.

I^«a

TS-930S "DX-traordinary"

re cal

i-traofdirv

pecause

the TS-930S has now become the
favorite rig of the serious contested
Its superior caoability for lull break-in
split-frequency operation, the speed
and convenience with which its eight
memory channels can be accessed,
its unsurpassed receiver dynamic
range and its remarkable ability to
select the desired signal during
periods of heavy QRM4 utilizing VBI
Slo* i IF Notch filtering, and

tuneat filtering, have alt

combi1 lake this the rig that

gives yo EXTRA EDGE!

The TS-930S is loaded with all
the special features that you always
wanted in an HF transceiver. Full

verage of the 160 through to
er bands, including the new
WARC frequencies, (easily modified
for HF MARS), plus a general cover-
age receiver that can tune any fre-
quency from 150 kHz to 30 MHz,
Operation in the SSB, CW, FSK, and
AM modes, with selectable full or
semi CW break-in. All solid-state,
with 250 waits PE put on SSB,

CW. FSK, and 80 watts input on
AM. SWR/power meter. Triple final
protection circuits plus two cooling
fans buiIHa tO-Hz step synthesized

TS-930S Optional Accessories:
AT-93Q automatic antenna tuner,
SP-930 external speaker, with select-
able audio filters, YG-455C-1 (500

frequency control. Aya with

optional automatic antenna tuner
bt mother industry first! Dual
digital VFQ's. Eight memory chan-
nels that store both frequency and
band information. witl iternal bat
tery back-up, (batteries not supplied).
Dual mode adjustable noise blankers,
especial) v effective in eliminating
"woodpecker" type interference.
SSB IF slope tuning, for maximum
rejection of interference. CW van-

Hz), YG-455CN-1 (250 Hz), YK-
88C-1 (500 Hz) CW filter, YK-88A-1
(6 kHz) AM filter, all plug-in type
SO-1 commercial stability TCXO,

MC-60A deluxe desk microphone,
MC-80 and MC-85 communications
crophones, MC-42S mobile hand
microphone, TL-922A linear amplifier
(not for CW QSK), SM-220 station
monitor, PC4A phone patch,
SW-2000 SWR/power meter, 160-
6 meter, SW100A SWR/power/volt
able bandwidth, with pitch and side- meter 160-2m HS-4, H3-5, HS*6.
tone control. IF notch f<fte; neable and HS-7 headphones
audio peaking filter. Unique six digit isn't it about time you stepped

white fluorescent tube digital display into the winners circle?
is easy-on-the-eyes during those More information on the TS-930S

long contests, RF speech processor,
for higher average "talk-power." SSB
monitor circuit 4-step RF
attenuator.

100-kHz mark*
AC power supply
built-in, 120, 220,
or 240 VAC.

is available from authorized deal
of Trio-Kenwood Communi cation
1111 West Walnut Street,
Compton, California 90220.

ns and prices are subject ro change without noi-

lUil^d1

i nm mm*

■ III

mw.iv

tf\ m

M AT t

: h ^ a u o .

LIMA* NtJICM Af n 0 1

At -*r f»<

•TUWRiBP"

PtlCH ** At TIJNf

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Full text of "73 Magazine (November 1984)"

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