•
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•
December 1978 $2.00
^A^
i.
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82
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114
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126
130
132
136
142
148
152
•I I- f^ -r
WB6JPZ
K8NQN
WA4JTJ
. NWY
W9CCI
Endre55r Endress
W1SNN
4 b J h
A DXer's Dream Vacation
— try sunny Montserrat , . . ,
Close Encounters
^the eyes of Texans are upon them
The Schizophrenic Triangle
^ a split-personality radiator.
From CW to Computers
— a digital modulation primer
A 28« TouchtoneTM Mod
—something for (almost) nothing. .
Space Age Surplus
— your own Saturn Vf ......... .
An X-Band Transceiver
— more 1 0CHz fun .... = ...... .
SSTV Recorder Controlter
— replaces your index finger
Receiver Diseases
—and how to cure them, .».,,..,
Aiitophaslng for WEFAX
— preserve your mental health
The Lunch Counter «
Confessions of a Stripper
—confirmed |unkor tells all . . .
Tuned Feeders and Other Good Stuff
— ^ho needs coax? . , WIVM
Build a Realistic S-Meter
-"you're S9 + 40, OM!" , DJ3NW
Wow! A Good Portable Receiver!
—thanks, PanasonK! WA2E|T'
The XITEX Video Terminal
— a quiet alternative to your Model
15 AH6AQ
Light Up Your Life
— the 2036 glows digital WA4NUt
High Seas Adventure — Ham Style
— part ML ,...,.,,..,,....,, WA6FEI
[|2 whither Mtcrocompufers?
— a pro looks ahead , . » .. WB2HJD
3 SSTV Meets SWTPC: Part 2
— micro^nhanced pictures K6AfP
KIJML
K4IPV
Cawthpn
WA4PfN
KSCNZ
160 Q^ A Multi-Memory Morse Machine
—using a Motorola micro , WA8TIW
164 ^ "This is Your Computer Speaking"
— how to dial up your micro. ..._,, Sorrels
170 [^ RTTY with the KIM
—one more step ....... r ....,..,, . VIIAKL
174 ^DX Delight
-3 do-it-all program WA4VQO, N3NN
182 Big Max Attacks
— it's W2DU vs. K4K1, in the battle of the
bazooka W2DU
192 The Packet Radio Revolution
— pioneers, take note! VE2PY
200 This Voltage Standard Is Precise!
--and makes calibration a snap WB6NTR
206 The 22S Goes Digital
— add 7-segment displays Klfilil
212 WARC '79 Preview
— showdown in Geneva WA9MZS
216 The "Flim-Flam" Factor
-another biased article, .,, WA2SUT(NNNfZVB
222 Build the Flexi Filter
— a very active device W3QVZ
226 The Klassic Kilowatt
-foufailAsdoit ,... , K4TWJ
230 Ham Radio Goes to School
— lO-year-olds love it. * ... . , ^ . . . . N2CF
234 What's Your uFI
— a siK-dfgit answer K5BTV
250 Fail-Safe
— protecting repeater batteries, WA7DP3(
256 Code-Practice Oscillators
— an exhaustive report . . . . . . . a^. , . W6GXH
270 PCs Are Easy
— step- by-step details* VE3CCE
274 The Games People Play
— why not hams? , . . WB3EUC
287 An Improved HV Tube Socket
^easy modification. , Miller
;»
Never Say Die- 4, Letters- 14. RTTY Loop- 16. Ham Help -16, 76, 80, 116, 134, 277, Looking West -18, DX-20. New Products -
22, Contest5-26, Faces, Places-70, Social Events-BI, Dealer Directory- 112, Corrections- 116, 278, AMSAT-134, OSCAR
Orbits- 27B, CARf — 27B, 1978 Index- 264, Propagation- 321
- SI
hannels
the palm
of your
hand
Tempo presents the
SYNCOM.,, the world's
first synthesized 800
channel hand held
Shown wilh iccessory touc^ torrg pacj
transceiver
This amazing pocket sized radio represents the
year's biggest breakthrough in 2-meter com-
munications. Other units that are larger, heavier
and are similarly priced can offer only 6 channels.
The SYNCOM'S price includes the battery pack,
charger, and a telescoping antenna. But, far more
important is the 800 channels offered by the S1-
The optional touch tone pad shown in the
illustration adds greatly to its convenience and
we have available a 30 watt solid state power
amplifier designed to give the SYNCOM S-1 the
ftexibiiity of operating as a mobile and base
station as well.
SPECIFICATIONS
Frequency Coverage
Channel Spacing
Power Requir^me'nls
Currien'i Drain.
Batteries
Antenna Impedance
Dimenstoris
RF Output
Sensitivity
144 to 148 MHz
Every 5 KHi
9 6 VDC
17 ma - standby ^00 ma - iransmii
Ni-cad batierv pack included
50 ohm$
40 mm* 62 mm* 165 mm (T 6"k 2.5" x 6.5'1
Qetier than 1 5 watts
Better than 5 microvcilis
SUPPLIED ACCESSORIES
Telescoping whip antenna, ni-cad battery pack, charger.
OPTIONAL ACCESSORIES
Toucli tone pad tof^e bursl generator, CTCSS chips. Rubber flest antenna^
Price $349 00 lof wwU toueti Kpr^« p^ S39& 00)
Tempo al&o offers • complete line of solid state power amptif
receivers, the FMH-2. 5 & 42 portables, the VHF/ONE PLUS
transceiver and the FMT-2 & FMT-4Z remote control mobile
AM evailable from Tempo dealers fbroughoyt the US,
Call or Mrrite for full information
lers. pocket
mobile
irensceiver.
11240 W.Olympic Blvd., Los Angeles, Calif, 90064 213/477 G701
931 N Eucfid. Anaheim, Calif 9Z801 714/772-9200
Bufler. Missouri 64730 816/679 3127
hkwt tribpct 10 di»nfft viihMi n^tct
»
-.>. J?. '..J,'
NOW SWITCHABL£
Not only is the big move to switch to the Wilson Mark Series of Mini-Hand-Hetd Radios, but now the
switch is on the Mark!
Wilson Electronics, known for setting the pace in 2m FM Hand*Helds, goes one step beyond!
AT NO EXTRA CHARGE:^ Mark Series Radios now will include a switch for you to control the"
lower of operation. This will enable you to use the high power when needed, then later switch to low j
power to conserve battery drain for extended operation. J
■ IN ADDITION: al[ Mark Series Radios now have an LED Battery Condition Indicator conveniently
[mounted on the top plate. A quick peek will reassure you of a charged battery in the radio,
Wiison hand-helds have been known world-wide for exceptional
quality and durable performance. That's why they have been
the best selling units for years.
Now the Mark Series of miniature sized 2-meter hand-hetds
offers the same dependability and operation, but in an easier
to use, more comfortable to carry size , , . fits conveniently
in the patm of your hand.
The small compact size battery pack makes it possible to
carry one or more extra packs in your pocket for super ex-
tended operation time. No more worry about loose cells
(shorting out in your pocket, and the economical price
makes the extra packs a must.
MARK II:
MARK IV:
1 & 25 watts
1&4j0 watts
V I ANT
0
SArt VOE
(• .# m
OFF TONL
Conveniently located on top
of the radio are the controls
for volume, squelch, access-
ory speaker mike connec-
tor, 6 channel switch,
BNC antenna connector
and LED battery
condition
indicator.
SPECIFICATIONS
•Ranger 144-148 MHz
• 6 Channel Opera tion
• Individual Trimmers on TX and RX Xtals
• Rugged Lexan^ outer case
• Current Drain: RX 15 mA
TX-Mark H: 500 mA
TX- Mark IV: 900mA
• 12 KHz C^ramfc Filter and 10.7 Monolithic Filter
Included.
• 10.7 MHz and 4S6 IKz FF
• Spurious and Harmonics: more than 50 dS
below earner
• BNC Antenna Connector
• .3 Mrcrovolt Sensitivity for 20 dB Quieting
« Uses special rechargeable Ni-€ad Battery
Pack
• Rubber Duck and one pair Xtals 52/52
included
• Weight: 19 oz. including
batteries
• Size: 6"x 1 J70'^x 2.440*'
• Popular accessories available:
Wall Charger, Mobile Charger,
Desk Charger, Leather Case,
Speaker Mike, Battery Packs,
and Touch ToneT"Padi,
i
Optional Touc4» Toiw'* Pad iw^ilable
To obiafn complete specifications
on the Mark II and Mark IV, along with
Wifson's other fine products, see your local
dealer or write for our Free Amateur Buyer*s Guide.
Illustrated is Witson's BC-2 Desk Top Battery Charger
shown charging the Mark Series Unit
or the 60-4 Battery Pack only.
Qmsttmer Products l^MSion
Wilson
Electronics Corp.
l^atiEms «u{?t*ct u> c^n^r vntlwdtfi noticw.
4288 South Polaris Avenue • P, 0. Box 19000 • Las Vegas^ Nevada 89119
Telephone (702) 739 1931 • TELEX 684-522
*^W2
p^ Rssd^r S^fv/cre— see peg* 353.
Staff
EBfTDR/FUBLISHEn
Wayne Gre^fi W2NSD/1
eCECUTlVE VICE PRESIDENT
SUmrty Smythe
ASSISTANT PUBitSHER
Jeffrey 0, OeTfay WB8BTH/1
ADMINISTRATIVE ASSISTANT
DoUy Gibson
MANAGING EDITOR
Jolin C. Burnett
ASSISTANT MANAGING
EOITOR
Susan G. Pbllbdck
NEWS EDITOR
Bm& Smarle WB6TOV/1
BOOK PUBLICATIONS
Beth Weston
PRODUCTION MANAGER
Lynn Panciera-Fraser
ART DEPARTMENT
Craig Brown
Gavle Cabana
Bruce He<lln
Ci^rl Jftck$on
Jdn-QS Lamoihie'
Dion Dw«ni
Nofli R. Self WBIARP
Robin U. Sicmn
PRINTING
G«ry Sreinbacti
Dan Moryan
PHOTOGRAPHY
8iii H&Y^ii^P^
TediS Putt
TYPESETTING
BAftwaa. Latll
8«n Bedell
Stisrtin D«mmerle
MifY KiJi^el
Holly Walsb
BOOKKEEPER
Knud E. M. Keller KV4GG/1
CIRCULATION
Barbara Block
Laura iarnicle
DATA ENTRY
Mary Kinzol
Denlse Loranger
DIRECTOR OF MARKETING
Robert R. LaPointe
BULK SALES MANAGER
Judy Waterrman
SHIPPING
Elhan Perry
Bill Barry
Michelle Witlsh
RECEPTIONIST
DQt\i Jarvi«
ASSOCIATES
Robefl Bakef W62GFE
E H. Bam^t WBttlX
ScbleyCox WBiLHO
Tofn OiBt^se W68KZD
TeffyFoM WB4JR
W. Sanger Green
Dave I Ingram K4TWJ
Unn KaJtanef WB2NEL
Joe KaMaf G3ZCZ
Bill Pasiemak WAfitTF
JohnSchull2W4FA
Waffer Scott KSQLZ
Peter Staik K20AW
Bill Turner WAf ABI
COMPUTER PROGRAMMING
Riohard J. Dyke ma
Ron Cooke WB9WHX
CUSTOMER SERVICE
Ftofence Goidmart
Joyce Tarr
Ellen Blanchard
ADVERTISING
AJine Coutu
Mafc4a Stone
WiMlaTTi a Vork
Nancy Ct am pa
W2NSD/1
NEVER SAY DIE
ec//tor/a/ by Wayne Gre&n
WARC DOOM AND GLOOM
Well, here we are with all
sorts Of exciting things going
on technically in amateur radio,
and Wayne Green Is preaching
doom. One day I'm up on a
mountain working with Chuck
WA1 KPS to make some record-
breaking contacts on 10.5 GHz
and d couple days Jater I'm talk*
ing to a group of hams at an
ARRL convention about the
possible loss of most or all of
our ham bands.
WItfi the coming microcom*
puter explosion in amateur
radio, the development of
packet radio transmissions.
the development of practical
double sideband systems, and
a host of other exciting
technical developments. It's
obvious that technically things
have never looked better.
With the coming Interna-
tional Telecommunications
Union (ITU) conference at
Geneva next October, never
have things looked worse for
the allocation of ham bands, I
hope, even more than you, that I
am Just a worrywart , , , and it
may turn out that my worries
are needless.
Having been one of the of-
ficial U.S. delegates to the 1959
ITU conference (the last full
conference), I am quite aware
of the pressures on amateur
radio allocations at that time.
We held our frequencies only
because of a miracle. No such
miracle seems possible next
time.
After a visit to 20 countries in
Africa and Asia, I wrote an
editorial in 73 outlining what I
had found. That was In 1966,
and I found that few countries
had any real use for amateur
radio or any understanding of
the value of the hobby to their
country. Many were so upset
over even the concept of third-
party traffic that they were
unable to evaluate amateur
radio reasonably.
After talking with amateurs
In these countries, I came up
with a proposal that amateur
radio societies around the
world try to encourage emerg-
ing nations to encourage the
use of amateur radio as a way
to develop the technicians and
engineers so badly needed in
small countries. Nothing what-
ever came of this until Isold His
Majesty King Hussein on the
concept in 1970 and he im-
plemented it immediately.
In 1971, the ARRL went to the
ITU to try to hold on to our ham
satellite frequency allocations.
There, according to the report
in OST, they found that the ma-
jority of the countries of the
world were opposed to amateur
radio and they lost every ham
satellite microwave allocation
we had . . . some 237,000 MHz
of them. Down the tubes went
any hope for worldwide ham
communications via satellite
other than on the smallest
scale.
Once it became clear to me
that there was no way that I
could get the ARRL or lARU to
approach the countries which
would In all probability shoot
down our allocations at WARC,
I tried first with some editorials
in 73 to encourage business-
men who were amateurs to car-
ry the ball. Nothing happened.
The only hope that I could
see left was to get a group of
the people who had the most to
lose financially, the ham in-
dustry, to take some action.
When the FCC actions on linear
amplifiers got so ridiculous
that something really had to be
done, the ham manufacturers
did start trying to form an
association. They tried to
cooperate with the ARRL, but
found themselves undercut
and sabotaged at every turn by
a League in fear of any
organization other than the
ARRL.
Had it not been for the ARRL
refusing to cooperate with
ARMA, the manufacturer's
association, we might not have
lost the linear amplifier battle
with the FCC. The fact was that
amateur radio put on a disor-
ganized response, while El A
had its act together and clob-
bered us. A large part of the
disorganization was directly
due to the League counsel and
Its weakening of the ARMA im-
pact. The ARRL testimony was
one of the most inept perfor*
mances I have ever seen and
was so bad the FCC Commis-
sioners were laughing over tt.
Yes, I've been an ARRL mem-
ber for over 40 years, but I still
get annoyed at the pitiful
leadership amateur radio has
to suffer. The "leaders'' are
third-rate bureaucrats without
a hope of achieving second
rate. They are protected by a
group of directors who, for the
most part, are afraid to offend
the bureaucrats.
The ARRL likes to pose as a
democracy, but they are much
more like a dictatorship. Think
about It. Members don't get to
vote for the officers at all, only
the directors . . . just like in
Russia. The directors (polit-
buro) vote for the officers. A
dictatorship is a one- party
system, just like the ARRL Why
is there only one party?
Because the dictatorship de-
stroys any possible chal-
lengers. The ARRL has had a
lonj history of doing whatever
it takes to keep any other
organizations from gaining
strength. Their latest coups
have been their jobs on the
QCWA and ARMA.
How did they get at ARMA?
Continued an pag& 7 12
?3Maga2fr>e ispubNshed FTX>nthly by 73, Inc., Peterijoromti NH 03456 Sutjscription rates In IhG U.S. and Canada are Si 8 tor one year, and $36 tor
tbree years Outside theU.S and Canada, write tor rales. Second cias^ fxist^^ paid al Petert?orDUQh NH 03458 and at additional mailing offices.
PubHcatl&n No 7O(J420. Phone. 603^924 3B73 Entire cor^ tents copy riaht 19/6 by 73. tnc INCLUDE OLD ADDRESS AND 2iP CODE WITH AD-
DRESS CHANGE NOTIFICATION. Microfilm edlHon— University Miciofilm, Ann Arbor Ml 4flt06.
When the MLA-2500 was first introduced it was a new concept in
high performance amplifiers. Low and sleek yet powerful enough
for the mnitary. Some wondered , . . needlessly.
A promise kept.
The IVILA-2500 promised 2000 watts PEP input on SSB- A heavy duty
power supply. Two Ermac 8875's. And as thousands of Amateurs across
the world have proven, the M LA 2500 delivers!
Now DenTron is pleased to bring you The new MLA-2500 B-
Inherently the same as the original MLA-2500, the B model includes all
of the above specifications plus a few refinements. New high low power
switching for consistent efficiency at both the 1 KW and 2KW power
levels, and 160 - 15 meters.
Tested and proven.
What better test for an amplifier than the Clipperton DXpedition?
Even after 32,000 QSO's, and an accidental dunk in the ocean, the same
3 MLA 2500's are still amplifying other rare DXpeditions around
the world — listen for them.
Convinced? Isn't it time you owned the amplifier that powered
Clipperton and thousands upon thousands of radio stations
throughout the world?
!VILA^2500B $899.50-
Radio Co Inc
2MX> £nfefpnse Pork
Tw^^StKifQ onto 44087
C21«425'3173
WINTER '78/79 PRODUCT LINE
M
(MUiO\
umMt
AT-21
II
SP-520
TS-520S fi DG-5
he AT-200 is an antenna
tuner, but it's also much more.
It's an antenna svvitch. an
SWR bridge and an in-tine
wait mater. The AT-200 re-
duces the dutter and increases
the operating efficiency of your
station . and at a surprfsmgly
moderate price.
The SP-520 matching speaker
offers improved sound m a
handsome cabinei.
The DG-S option gives you
your exact frequency, while
transmitting and receiving, in
farge easy to read digits by
mixing the carrier, VFO. and
heterodyne frequencies.
The VF0-S2a remote VFO is
a perfect match for your TS-
520S and provides maximum
operating flexibility.
The TV-502S 2-meter trans-
verter produces 8 watts on
SSB and CW It easily hooks
up to the TS 520 and TS-820
series transceivers, providing
an inexpensive method of get-
THE TS-520S SERIES LITERALLY TOOK THE AMATEUR WORLD BY STORM. NO OTHER RADIO EVER
CAUGHT ON SO FAST AND THE REASONS ARE OBVfOUS,.. EXCELLENT PERFORMANCE
CHARACTERISTICS, DEPENDABILITY, FLEXIBILITY, AND A VERY SOLID VALUE FOR THE PRICE. AND
NOW THE TS-520S SERIES OFFERS THE MOST COMPLETE LINE OF ACCESSORIES AVAILABLE,
FULL COVERAGE TRANSCEJVER
The TS-520S providfis full cover-
age on afl amateur bands from
1.8 to 29.7 MHz Kenwood giv^s
yoij 1 60 meter capabiJity. WWV
on 15.000 MHz., and an auxil-
iary band position And with the
addrtion of the TV-506 iransverter,
your TS-520S can cover tSO
meters to 6 maters on SSB and
OUTSTANDING RECEIVER
SENSITIVITY AND MIMMUM
CROSS MODULATION
The TS-520S incorporates a
3SK35 dual gate MOSFET for
outstanding cross modulation and
spurious response characteristjcs.
The 3SK35 has a low noise
figure (3,5 dB typ.} and high garn
(18 dB typ.) for excellent
sensitivity,
NEW IMPROVED SPEECH
PROCESSOR
An audio compression amplifier
gives you eictfa punch in the pile
ups afid when the gotng gets
rough.
VERNIER TUNING FOR FINAL
PLATE CONTROL
A vernier tuning mechanism
allows easy and accurate adjust-
ment of the plate control during
tune- up,
FINAL AMPLIFIER
The TS-620S is completely solid
state except for the driver and the
final lubes.
Kenwood has employed two
husky S-2001A (equivalent to
6146B) tubes. These rugged,
time-proven tubes are known for
their long life and superb linearity,
HIGHLY EFFECTIVE NOISE
BLANKER
An effective noise blanking cricuit
developed by Kenwood that vir-
tually elimifiates ignition noise is
built into the TS-520S,
RF ATTENUATOR
The TS'S20S has a butJt-in 20
dS atientuator thai can be acti-
vated by a push button swfch
convenienily tocated on the
front panel.
PROVISION FOR
EXTERNAL RECEIVER
A special jack on the rear panel
of the TS'520S provides receiver
Signals to an external receiver for
increased station versitility A
switch on the rear panel deter-
mines the signal path , , . the
receiver in the TS-B20 or any
external receiver.
CW-520-CW FILTER (OPTIONJ
The CW*520 B0O+<z filter can be
easitly installed and will provide
improved operation on CW,
AMPLIFIED TYPE AGO CIRCUIT
The AGC circuit has three posi-
tions (OFF, FAST SLOW} for
optimum operation on CW.
AC POWER SUPPLY
The TS'520S is completely self-
contained with a rugged AC
poMcr supply built-in The addi-
tion of the DS! A DC'OC
converter (optional) allows for
mobile operation of fhe TS-520S
EASY PHONE PATCH CONNECTIO
TheTS-520S has two convenient
RCA phono jacks on the rear
pane^ for PHONE PATCH IN and
PHONE PATCH OUT.
The TS-520S retains all of the
features of the original TS-520
that made it tops in its class: RIT
control • 8-pole crystal filter •
Built-in 25 kHz calrbrator* Front
panel carrier level control * Semi-
break-in CW with sidetone •
VOX / PIT /M OX -TUNE posaion
for low power tune up • Built-in
speaker • Built-in cooling fan •
Provisions for four fixed frequency
channels * heater switch.
VF0-520S TV-502S TV-506
SM-220
ting on the 2'meter band.
The TV-506 is an equally prac-
tiCaJ way of getting on the 6-
meter band, providing 10 watts
on SSB and CW.
The SM-220 is an extremely
useful and unique station
monitor. It allows you to moni-
tor your transmissions, monitor
incoming signals and monitor
the amount and strength of
band activity* and performs as
a general purpose 10 MHz
oscilloscope, as well.
"Wuh BS-5 or ESrE pan d^pH^f OQttor^
r. , , hfurxnirr »f nmamtr r
w
The TS'820S . , . known world wide as the Paca&etter. Amateur
Radio Operators urtiversalfy mspect its superb qualitv. proven
through thousands of hours of operating time ynder all environ-
mental conditions. The TS 820S has every feature any Amateur
could desire for operating enjoyments on any band from 160
through a IT of 10 meters.
You can always tefl who's running a TS-
820S- Its superb quality stands out from
all the other rigs on the band . . and when
the QRM gets heavy, the TS-820S's
adjustable RF speech processor, utilizing a
45 5-kHz circuit to provide quick-time-
constant compression, will get the message
through. RF negative feedback is applied
from the final to the driver to improve
linearity, and third-order products are at
(east —35 dB. Harmonic spurious emis*
sions are less than ^40 dB and other
spurs are less than —60 dB. RF input
power IS 200 W PEP on SSB. 1 60 W DC
on CW, and 100 W DC on FSK. Receiver
sensitivity is better than 0.25 /xV for 10
dB S/N- TheTS-820S is known for its
superb receiver selectivity, and its famous
IF shift easily eliminates heavy QRM.
That's why the TS 820S is the DXer's
choice.
See your local Authorized Kenwood Dealer
today
TkPe^CS
SP-820 TS-820S
VFO-820
TV-506 SM-220
• *
Muy HuiilJmMOOO
Kenwood devetoped the T-599D transmitter and R*6990
receiver for the most discriminating Amateur
The T-599D transceiver is solid-state with the exception
of only three tubes, has built-in power supply and full
metering. It operates CW, LSB, USB and AM and, of
course, is a perfect match to the R-599D receiver.
The R-599D is the most complete receiver ever offered. It
is entirely solid-state, superbly reliable and compact. It
covers the full Amateur band. 10 through 160 meters,
CW, LSB. USB. AM and FM.
l^owi itatZb^^ iMtt cOiwpfetJL ii Itdm'iLt uicM£,tftje,1?-820
introducing the ultimate in receiver design
. . . the Kenwood R-S20.
Whh more features than ever before ava ilabte
in a ham-band receiver, This tripleconversion
(8.33 MHz, 455 kHz, and 50 kHz IFs) receiver,
covermg alf Amateur bands from 1 60 through
10 meters, as well as several shortwave
broadcast bands, features digital as well as
analog frequency readouts, notch filter, IF
shift, variable bandwidth tuning, sharp IF
filteiTS, noise blanker, stepped RF attenuator,
25 kHz calibrator, and many other features,
providing more operating conveniences than
any other ham-band receiver. The R-820
may be used in conjunction with the Ken-
wood TS-820 series transceiver, providing
futl transceive frequency control.
Additional features include A monitor switch
which aUows the user to hear his own voice
when using associated transmitter. Either VFO
control or crystal control on four selectable
frequencies Digital hold . , , locks counter and
display whtle VFO is tuned to another fre-
quency ... faciMtates return to *'hold" fre-
quency. RIT/ notch control . . . RIT allows
receiver to be tuned off frequency, while not
affecting transmit frequency when in trans-
ceive mode with TS-820S, Notch control
tunes notch within IF passband for elimina-
ting interference, Interfering signal remains
notched even when IF shift is utilized. Built-in
crystal calibrator, settabfe to WWV provides
signal every 25 kHz. Noise blanker/level
control . . . for maximum reduction of noise
interference. A transceive/separate switch
enables receive VFO to control the receiver
and TS-820 (or TS-820S) frequency (or the
TS-820 VFO to control both), or, of course,
both can Function independently
IktiAmtvmdMt pcuk (HLtfct ot/L
you have never considered the advantages of operating
a receiver/ transnnitter combination . . . maybe you should.
Because of the larger number of controls and dual VFOs
the combination offers flexibility impossible to duplicate
with a transceiver.
Compare the specs of the R-5 99D and the T-599D with
any other brand. Remember, the R-599D is aH solid-state
(and includes four filters). Your choice wifl obviously be
the Kenwood.
# # ■
1
^ KErMWOOD oah/i«MJ>^iE3MTii:3Nn miECEiweta imciuc:i^ *h -Monts
10 WATT
. . . KENWOOD
OFFERS A
CHOICE
• Full 4'MHz coverage (144.000-147.995 MHzJ
on 2 meters • 800 channels • Dual concentric
knobs for fast frequency change (lOO-feHz and
lO-kHz steps) • 5-kHz offset switch • MHz
selector switch .for desired band (144, 145*
146. or 147 MHz) • Mode switch for operating
simplex or for switching the transmit
frequency up or down 800 kHz for repeater
operation , . or for switching the transmitter
to the frequency you have stored in the
TR-7600's memory (while the receiver remains
on the frequency you have selected with the
dual kJiobs) • Memory channel, wtth
simplex or repeater (plus or minus GOO kHz
transmitter offset) operation ■ Dtgital
frequency display (large, bright, orange LEDsJ
■ UfslLOCK indicator an LEO that indicates
Iranscetvef protection when the frequency
sefector switches are improperly positioned,
or the PLL has malfunctioned • tO watts RF
ouiput (swltchable to 1 watt low power)
• Noise-cancellir^g microphone • Compact
SFze (on^y 6-7n6 inches wide, Z'7^16 mches
high, and 9*3/16 inches deep)
The RM-76 Microprocessor Control
Unit provides more operating
features to the TR-7600 2'metef FM
tranceiver than found in any other rlgf
Wtth the AM -76 Microprocessor Control Unit
attacheif to your TR-7eOG, you can...
• Select any 2-metef frequency • Store
frequencies in six memories ■ Scan af^ memory
channels • Automaticatly scan up all
frequencies in 5-kHz steps « Manyatly scan up
or down \n 5-kHz steps • Set lower and upper
scan frequency timits • Reset scan to 144 MHz
• Stop scan (with HOLD button) • Cancel scan
(for transmittmg) • Automatically stop scan
on fifs! busy or open channel > Operate on
MARS (143 JS MHz simplex only) * Select
repeater mode (simplex, plus transmit
frequency offset, minus offset, or any of six
memory transmit offsets) • Select transrt^it
offset (1 MHz/600 kHz}
The Micfopfocessor Control tlntt's display
Indicates frequency (even while scanning) and
functions (such as autoscan, lower scan
frequency IFmitt upper scan limit, error,
dftd call channel)*
Subject to FCC approvpij
SP-70 VF0-700S
StUf th© sama fine, time proven rig. But now with
the simple addition of a plug-in crystalp the
TS'7Q0SP will be able to utilize the new repeater
3ut)"band (144.5 to 145,5 MHz). Still features all of
the fine attributes of the TS-700S: A digital
frequency display* receiver pre-amp, VOX, semi-
break in, and CW sidetone. Of courser it's all mode.
144-148 MHz, VFO controlled , , . and Kenwood
quality throughout.
Features: 4 MHz band coverage
(144 to 148 MHz) • Automatic
repeater offset capabrlity on all FCC
authorized repeater subbands
including 144.5-145.5 MHz •
Simply dtai receive frequency and
radio does the rest . . . simplex, re-
peater, or reverse. Same features
on any of 11 crystal positions ■
Transmit /Receive capability an 44
channels with 1 1 crystals • Oper-
ates alf modes: SS6 {upper and
towerK PM, AM and CW • Digital
readout with "Kenwood Blue '
digits * Receiver pre-amp • Built-in
VOX • Semi break-in on CW • CW
sidetone • Ail solid-state • AC and
DC capability 10 watts RF ouiput
on SSB, FM, CW • 3 watts on AM
» 1 watt FM low-power switch •
0.25 /iV for 10 dB (S+N)/N SSB/
CW sensitivity - 0.4 juV for 20 dB
quieting FIVl sensitivity,
br2 5 WATT OUTPUT
f
i
VOL*^SQU
KEMIATOOO
am o*f
2m Fil TRANSCEIVER
Mrf i
,ft(^«r
t •
3 ± J:
too KHl
10 kHz
TX OFFSET
H* -P tOL
WJC
h 'ȣ
MHf
*«*
i «*J'
siEiyt
pomts
v\
*.<m
T«-7aOQA
The fuily-synfhasized TR-7400A 2 -meter
FM transceiver operates on 800 channels
and features repeater offset over the
entire 144-14&-MHz range, dual fre-
quency readout, six-digit dfsplay, and
subaudible tone encoder and decoder.
RF output is at least 25 waits!
The TR-7400A 2-nneter FM traoscerver
provides fully synthesi2ed operation,
includtng BOO-kHz repeater offsets,
over the entire 144'T48-MHz range, ft
can operate on any of 800 channels,
spaced 5 kHz apart. RF output is at
least 25 W, and typrcally 30 W, A lov^^
power position produces 5-1 5 W (ad-
justable). Included is a dual frequency
readout with large six-dtgit LED dis-
play plus a dial readout, The sub-
audibfe CTCSS stgnalmg feature may
be used on transmit and receive, or
transmit only. Optional tone-burst
modules are available. Receiver sen-
SHivity IS better than 0 4 ^V for 20
dB quieting. Large, high Q. hehcal
resonators minin^ize interference frorn
outside the band. A two-pole 10.7-
MHz monolithic crystal filter provides
excellent selectivity, Intermodulation
distortion is down more than 66 dB.
spurious rejection is better than —60
dB, and image rejection is better
than —70 dB.
See your local Authorized Kenwood
Dealer today, for a demonstration of
the fantastic TR-7400A.
Expenence the excitement of 6
meters. The TS'600 afl mode
transceiver lets you experience
the fun of 6 meter band openings
This 10 watt, solid state rig cov*
ers 50 0-54.0 fVlHz. The VFO
tunes the band in 1 MHz seg-
ments, h also has provisions for
fixed frequency operation on
NETS or to listen for beacons.
State of the art features such as
an effective noise blanker and the
RIT (Receiver Incremental Tun*
tng) circuit make the TS-600
another Kenwood ' Pacesener *
TRIO KEfy WOOD COMMUNICATrONS IhfC,
1111 WEST WALNUT/ COM PTON. CALIFORNIA
K,pan\S4iter hi amaleur radiu
WtTB^
EJ#*E*«
TIK-^
-'Qir^AATE
j^jjME^^^A ^iv**^n_rPieR
GuAt OfW/L A^Jtoi e0JL^lMJU6clk
The Kenwood name has grown to represent the finest Ama-
teur Radio equipmeni available. The TL-922A linear amplifier
carries on that tradition. As a linear it gets your signal through
today's crowded bands and provides the power to reach those
far away places with ease. And because it's Kenwood you
can count on its dependability. The TL922A is FCC type ac-
cepted. It runs the full legal limit on all ham bands from
160-15 meters and is compatible with most amateur exciters.
Contact your nearest Authorized Kenwood Dealer for com-
plete specifications and the best deal,
WHY SHOULD THE TL 922A
BE PART OF YOUR
STATION? COMPARE
THESE FEATURES AND
SPECS THE ANSWER
WHL BE OBVIOUS,
Instant healing filaments —
The 3-60DZ tubes require no
warm yp period. Just turn it
on and go!
Time dolay fen crrcuh — Even
after you turn the TL922A off,
the super quiet fan continues
to work for approximately 2
minutes to greatly extend tube
IJfB.
Adjustable ALC output volt-
age — Lais you taitor the ALC
voltage to your exciter.
Stdfidbv position — Provides
amplifier bypassing without
having to turn the AC power
off.
Two independent safety in-
terlocks — One disconnects
AC line voltage and the second
shofts 8+ to ground when
tripped.
Vernter plate control — For
smooth easy tune-up.
Diecast side panels — Inctudes
functional carrying handles tor
easy transportation.
Thermal protection of power
transformer — Amplifier auto-
matically switches to standby
if power transformer tempera-
ture exceeds MB^'F.
Tuned Input Circuit — Means
improved spurious character-
istics.
Line voltage selector — Easily
switched between 120 and
240 VAC.
Multimeter — Reads high vol-
tagsi relative output or grid
current (selectable),
Plate Current Meter — Separ-
ate meter allows continuous
monitoring of plate current.
Dependable operation, superior specifications and excellent
features nnake the R-300 an unexcelled value for the short-
wave listener. It offers full band coverage with a frequency
range of 170 kHz lo 30.0 MHz • Receives AM, SSB and CW
• Features large, easy to read drum dials with fast smooth
dial action * Band spread is calibrated for the 10 foreign
broadcast bands, easily tuned with the use of a butk-in 500
kHz calibrator • Automatic noise timiter • 3'way power sup-
ply system (AC/ Batteries/ EKternal DC) . . . take it anyplace ■
Automatically switches to battery power in the event of AC
power failure.
\v*»
\
^^1 ji_UiSjio*M- •_- -
B
1
■
1,
1'
How would you like to work an uncrowded frequency . . . hear signals with fess
noise . , .or use a sophisticated repeater or remote base with better coverage?
440 MHz is the answer. It will surprise you. It wHI penetrate buildings where 2
meters won't, and often you can even work out from underground garages , . .
where 2 meters is dead.
Best of alL it's easy to get on 440 MHz (70 cm) . . . with a Kenwood TR-8300
transceiver. High quality is critically important on VHF bands, and the TR-8300 is
just what you need to meet afl technical requirements.
■
• 10 watts RF output (switchable to 1 watt)
'23 crystal-controlled channels {3 supplied)
445. 0-4 50.0 MHz transmit range
• 442,0-447.0 MHz receive range
• Transmitter and receiver adjustable over any
5-MHz segment from 440 to 450 MHz
• 5-sect(on helical resonator and 2-pole crystal
filter m IF to reject intermod
SWR protection in final amplifier
■ Excessive-voltage ana reverse-polarity
protection circuits
• 0,5 jLtV for 20 dB quieting sensitivity
• Better than ^60 dB spurious radiation
• 20 kHi (-6 d8), 40 kHz {-70 dB} selectivity
• Monitor switch that lets you check modulation
and frequency 'neltmg'
• Call CH switch that activates optional CTCSS
(subaudible tone) function
■ Large S meter
MoviB up to 440 MHz today. . . with a
Kenwood TR-8300. . , for more refrabfe
conrm unica tionsi
HF LINES
820 Series
TS'820S.
TS820. .,
YG-eSA,..
YG-455C.
YG-4B5CN
TS-820 with DigiiBl Installed
160-10 m DeFuxa Transceiver
6'kHz AM filter for R-2G0
500-Hz CW fitter for R-820
2B0-HZ CW fjltef for R-820
BS-5 . . .
AT-200
DS'IA.
7m equipment that belongs in every
well equipped statim
SM-220 pan display for TS-820 Series
SM-220 pan display for TS'520 Series
200'W antenna tuner, SWR /power
meter, switch
DC-DC Convertet- for 520/820 Series
DG-1 Digital Frequency Display for TS-S20
Deluxe Remote VFO for TS-820/820S
Externa! speaker with audio filters
500 Hz CW FiUer for TS^820/S20S
VFO'S20..
SP-820...
CW-B20...
520 Series
75-^6205 . . 1 60-10 m Transceiver
DG-5 Digital FreqLfencv Display for TS-520
Series
VFO-520 . , .Remote VFO for TS'.520 and TS-520S
SP-520 External Speaker for 520/820 Series
CW^520. . . 500 Hz CW Filter for TS-520/520S
DK-520. . . Digital Adaptor Kit for TS-520
599 D Series
SHORT WAVE LISTENING
R-300 Genersl Coverage SWL Reveiver
VHF LINES
TS-600. ... 6 m All Mode Transceiver
TS-700SP. 2 m l\\\ Mode Digital Transceiver
VF0-700S, Remote VFO for TS-700S
SP-70 Matching Speaker for TS'600/700
Series
VOX-3 . , , . . VOX for TS-600/700A
TR-7400A. 2 m Synthesized Deluxe FM Transceiver
TR-7600. . .2 m FM transceiver with 800 channels
and memory
RM^76.. .
TR^S300.
TV^506 . .
TV 502S ,
Remote Controller for TR 7600 with
six memories, scanning
.70 CM FM Transceiver |450 MHz)
6-m Transverter for 520/820/599
Series
. 2-m Transverter for 520/820/599
Series
R-599D. . .
T-5990,..
CC-29A. , .
CC-69A. , ,
FM^599A,
160-10 m Solid State Receiver
80-10 m Matching Transmitter
External Speaker for 599 D Series
2-meter Converter for R-599D
6 -meter Converter for R-5 99 D
FM Fiiterfor R-599D
MORE ACCESSORIES:
POPULAR STATION ACCESSORIES
HS-4 Headphone Set
MC-30S. . ^ low-impedance mobile nQise-cancelling
microphone
MC-35S. . . high-impedance mobile noise-cancelling
microphone
MC-50. . . , Desic Microphone
PS-6 Power Supply for TR-8300
PS-3 Power Supply for TR-7400A
Trio-Kenwood stocks a complete [ine of replacement
partSr accessories, and manuals for aii
Kenwood models.
HF ACCESSORIES
TL-922A. . . 1 60-15 m kHowatt linear amplifier
SM-220. . . Station monitor, 10- MHz scope
DescriptiDn
Repeater Subb^nd Kit
Rubber Helicai Antenna
Teieficopin^ Whip Antenn£»
Ni-Cad Battery Pack (set)
4 Pin Mic. Connector
Active Fifter Elements
Tone Burst Modules
AC Cables
DC Cables
Model ^
RSK-7
RA-1
190-0082-05
PB-15
E07'04O3-O5
See Service Manual
See Service Manual
Specify JVIodel
Specify Model
For use wtfith
TS-700A/S
TR-2200A
TR-2200A
TR'2200A
AiJ Models
TR-7400A
TS-700A; TR-7400A
All Models
All Modefs
>Y -^
The Kenwood HS-4 headphone set adds
versatility to any Kenwood station. For
extended periods of wear, the HS-4 is comfort-
ably padded and is compl^etel^y adjustable. The
frequency msponse of the HS-4 is tailored
specifically for amateur communication use-
(300 to 3000 Hz. 8 ohms).
The MC-50 dynamic microphone has been
designed expressly for amateur radio operation
as a splendid addition to any Kenwood shack.
Complete with PIT and LOCK switches, and a
microphone ptug for instant hook-up to any
Kenwood rig, Easily converted to high or low
impedance. iSOO or SOk ohm).
TRIO-KENWOOD COMMUNICATIONS INC.
1111 WEST WALNUT/ COMPTON, CA 90220
'" troji r
^^ 'J
QUASf PRIMA DONNA
OncBt as an untutored, not-
yet-jaded youth of 15J had the
temerity to write the editor of
OSr suggesting that the ARRL
lend *'Gil" to the Government of
India, where his wretched iV\
yo-yos doing all the li'i no-nos
could be used to far greater ad-
¥anta9e on birth control prop-
aganda posters.
The resulting correspon-
dence has been long mis-
placed, but be assured, alt hell
broke loose; as 1 saw it in 1965,
anyway.
Now I freely confess to being
a nostalgia freak and, In hind-
sight, some "Gil" illustrations
are their own reward. It was in
September of this year, how-
ever, that I found that the gates
of hell can still t>e flung open on
command, and while they
couldn't really do much to a kid
of 15. it will really amaze you
what can be done to a married,
professional fellow of 33.
Right now, you're probably
wondering what this has to do
with the pr^ce of opium in
Macao. Stay with me and I shall
enlighten you.
When Wayne Green was the
editor of CQ I thought It was the
neatest and funniest magazine
in the world, (I was a very ar-
cane kid.) After joining the
Navy in 1957, suff Bring through
ET school at Treasure Island {in
the winter), and being assigned
to the fleet, I looked forward to
my COs B'^ery b\l as much as
letters from my steamy girl
friend. Now I realize this
sounds bizarre on the face of it,
but if you are fortunate enough
to know an old-time ham with a
storeroom full of old radio
magazines, be prepared to see
some ham cartoons worthy of
the name, it's been years since
a sample of this genre has
brought much more than a
"yeechh" out of me- It also
goes without saying that his
**jack-em-up" editorials were
about the same, bot somehow
not so pessimistic, and far
more entertaining. But we all
march to the clock and that,
really, is the whole point of
what Tm trying to get to.
How emotional have I got-
ten? Well, Tve gotlen so emo-
tional that I shot off a hot
telegram to Mr. Richard Bald*
win W1RU, using not one of the
seven dirty words, but express-
S\\ft i^hOu
ing my feeling strongly.
Please be advised that such
a course is not tor the faint-
hearted, but the only fair com-
parison between me and the
late Arnold Stang is glasses.
To get Mr, Baldwin's atten-
tion (Le., to let him know I did
not survive by scouring alleys
for unbroken pop bottles), I
mentioned my company*s
name and the position 1 oc-
cupy. This was a mistake
— whether mine or his is not yet
clear.
I am not a member of the
ARRL anymore, which is
wrong, I suppose, because it
puts me somewhat In the posi*
tlon of a rock thrower-
The reason I'm not is simply
because the itiusion of a retard-
ed bear cub swatting incom-
petently at a newty found ap-
pendage is quite torturous.
Allow me to digress-
I am employed by a hallowed,
old'line radio company
(okay— the first 3 letters of
which is the same as hallowed,
and deservedly; that's as far as
I go) that receives gratis copies
of all the ham and related
monthlfes.
To thine own self be true, I
read these on breaks and at
lunch— 1 guess I'll never grow
up—and have become some-
what emotional about WARC
'79.
I wanted to get his attention
to possibly start a dialogue or,
more to the point, to do his
damn job instead of being
some sort of quasi prima donna
fiddling while our frequencies
burn.
What happened was totally
unexpected. The League Pooh-
bah is not a Pooh-Bear, he is a
Nixonian treasure, and I now
have the questionable distinc-
tion of being on Richard's
enemies list, with a vengeance,
A. On Saturday, September
16, I got a personaily-dictated
fetter from W1RU telling me he
"does not respond to corre-
spondence personally calling
him a son of a bitch"— which
was not really true. Hang on.
The telegram will be printed,
regardless of the accuracy or
inaccuracy of the statement. (I
know the concept here is tor*
turous.) This was the first non-
response.
B, I was greeted at noon, on
Monday. September 18, with a
Xerox copy of a letter guaran-
teed to catch fire when ex-
posed to light, written by W1 RU
to the President of my com-
pany, the text of which I cannot
relate verbatim, presented by
my boss,
W1RU pulled out a// the
stops to get me fired in the
sleaziest, mosi innuendo-peP'
pered misuse of personal
power I have ever had the mis-
fortune to read. The very inac-
curacy and overkill of the at-
tempt, in our times of universal
free-ha-ha, literally saved me, I
am truly fortunate to work for
some fine, decent human be-
ings. This was the second non-
response*
I guess this is where I should
say that, gee, it's only a hobby,
folks. But it's much more than
that VvB been caught up in the
mystique and adventure of ham
radio like few others. I per-
sonally feel that the Arabian
nights I have spent over the
warm smell of communications
equipment, listening to and
talking with people the world
over, and looking out of my win-
dow at the starry early-morning
sky, have shaped my personali-
ty. I truly don't know what \
would have done in the 1800s—
my greatgreat uncle was a
renowned gunflghter (Will
Stokes), but I donl think that
would have been my calling.
It*s just lucky to be here today,
with the apparatus existent to
fly your fancies according to
your innermost, gut-wrenching
needs.
Now, to that telegram. Being
worked up over losing all this to
a bunch of people who don't
even have the wherewithal to
utilize it, I said:
If Wayne Green's September
editorial Is even 10% correct, you
SOBs should be dismembered and
thrown to a ^ack of wild dogs.
Terry Siaudt wewuz
Company Tliie
This is a good old Colorado
saying used sparingly to ex-
press true disgust. There is
also some humor there that
evidently loses itself when put
in print, especially to plastic
people of the job set.
I sincerely hope, as does Lew
McCoy, Wayne, and Johnny
Johnson, that the ARRL gets Its
act together in time to properly
present our incomparably-just
cause.
Terry Staudt WiWUZ
Ft. Worth TX
TAKE A LICKING?
Many of my friends are
"wheels'^ in CCIR, URSL IEEE,
etc. Just two weeks ago there
was an international meeting
of URSI {IntI Sci Radio Union) in
Helsinki. One of my old college
buddies Is a commission charr*
man (in charge of matters re-
lating to radio noise, man-made
and natural). He told me, In
passing, that he's afraid the
hams are going to take a licking
at WARC— something similar
to what Wayne has been
writing about. This friend of
mine had recently talked to
Dick Kirby. In fact, he had put
together a panel wherein Kirby
and several other spectrum
managers talked. Also, my
friend last year edited an entire
IEEE volume on spectrum man-
agement, including articles on
WARC,
Well, I happened to tele-
phone the ARRL the next day
and asked to speak to the guy
in charge of WARC relations. It
turned out to be Bruce John-
son, whom I don't know. Any-
way, Johnson assured me
that my friend (who's worked as
a radio engineer for Stanford
Research Institute for 20 years
. . . and has had very close con-
tact with CCIR, etc.) is aft
wrong.
Aiso^ Johnson had never
heard of URSI! He wasn't sure
he'd heard of the IEEE Spec-
trum Management group. The
ARRL had turned down Stan-
ford Research Institute's pro-
posal to do a study for the
ARRL which could also be used
by third-world countries to sup-
port ham needs in the HF and
VHP spectra.
Johnson was also sure that
anything that goes on at inter-
national meetings such as
URSI can't affect WARC since
alt countries have already
decided on their plans, (This is
8.S., since many third-world
countries are in limbo*)
in any case, the message I
got was that the ARRL is all set.
They know all that's worth
knowing, and guys like me, who
worked for the National Bureau
of Standards CRPL back when
Johnson was in grammar
school, are to l>e tolerated but
not listened to.
By the way. W1 FYM just told
me that Bruce Johnson had
promised to join us for our 1978
Field Day QRP-computerized
operation. Two days before
Field Day, Wl FYM asked about
Johnson and somebody at the
ARRL told him, "Oh, Johnson's
not going with you guys. He
had the chance to go to Penn-
sylvania and work Field Day
with some real big shots.,,"
Johnson didn't even bother to
tell us.
Plus ca change. . .
C. Stewart GlllmorWtFK
Higganum CT
[
SRRL?
ril preface the foltowing with
the fact that I have been a
member of the ARRL for most
of my 22+ years as a ham.
Have you heard about the
latest attempt to set up a dic-
tatorship by the Board of DIrec-
14
tors of the League? It was bad
enough when they stripped
Mary W7QG P of the right to run
as Washington SGM. Now they
have taken on the entire
League membership of the
Northwestern Division: Alaska,
Idaho, Montana, Oregon, and
Washington,
In case you did not hear
about the latest news from
Newington, here goes: Mary
was to run against the incum-
bent, Bob Thurston W7PGY, for
Director. It seems that the Ex-
ecutive Comnnlttee decided
against allowing the members
of the Division to democratical'
ly decide who is the better can-
didate. Instead, they *'post-
poned" the election and gave
W7PGY the position until after
the election is "decided." The
election has been postponed
until the current litigation be-
tween Mary and the League is
completed. If that litigation
takes another two years, then
Bob Thurston will have been
the appointed Director for his
entire term of office!
1 wrote to Dick Baldwin, but
do not expect any answer, un-
less It Is a form letter. I will not
resign from the ARRL, as they
may not be doing much, but a
little is better than nothing with
WARD coming up next year.
Anyway, to paraphrase the let-
ter to W1RU, "Welcome to the
Soviet Radio Relay League!"
Keep up the fight. We need
some voices In the wilderness
agafnst the fuddy-duddies in
Newington, and you do a better
job than Cowan does in CQ. Oh
yes, Wayne. ^'Looking West" is
a good column, but contrary to
what Californians believe,
there is a lot more to the west
coast than 6 Land!
Jerry Ostrer W7EMX
Vancouver WA
ROSE-COLORED GLASSES
1 Just finished reading a letter
to you from Carl Manion
W4BDC in the September, 1978,
fssue of 73. In his letter; Mr,
Manion was highly critical of
your stand against some ARRL
policies, and of similar policies
of the other ham magazines.
I have been reading all of the
"big four*' ham rags (except
CQ) now for twenty years, or
since the first issue of each
respective magazine, and I
want you to know that this Ken-
tuckian totally agrees with your
opinions and especially with
your right to express them.
Perhaps the reason QST, et al,
remains silent in respect to
Wayne Green and 73 is the old
"let's ignore him and maybe
hell go away" theory. Or then,
again, maybe it's because they
know they have no defense
against the truth.
I applaud you and your staff
for being the leader in ham
magazines. There's no doubt
about It ... 75 is way out in
front. Please don't stop keep-
ing us informed of the trutti,
even when it sometimes hurts.
In closing, let me say that I
am sure that for each renewal
you don't receive from people
in Mr. Manion's league, you wili
get three or four from those
who welcome the truth and
donM see ham radio as a
wonderful hobby through a pair
of rose-colored glasses.
Michael W. Babb N4PF
Louisville KY
EMEMLES NOT NEEDED
Jam 10 GHz police radar? If
we lose this band, you will
receive a bill for my two Gunn-
plexers. With friends like you,
amateur radio doesn't need
enemies. Just because some-
one writes an article doesn't
mean you have to print it,
Steve Noll WA6EJ0
Ventura CA
REALLY WEIRD
This reader has held a Class
A (Advanced class) ticket since
June of 1939 and therefore
qualifies as something of an
old-timer.
You are correct in that the
ARRL has made some mis-
takes. The first was in not bat-
tling the FCC (if necessary) to
the end when the Ctass A sub-
bands were opened to all
General class tickets. This
problem was remedied when
'Mncentive" licensing was
restored, even though this ham
lost some privHeges until this
year when he f i nally went up for
Extra class and upgraded. The
other mistake was in not doing
everything to prevent amateur
licenses which omitted the 13
wpm code test.
There are certainly many ex-
cellent technical men with
Technician class licenses, but
that is not the point. The reader
whose letter appeared in your
Letters column a few issues
ago stating that the code bands
will eventually be opened wide
to phone simply is too much of
a ''young squirt'' to know the
score. No matter how much ad-
vancement is made in the art,
as the number of hams in-
crease and, hence, increase the
QRM, the ham bands will even-
tually become like the CB chan-
nels are today, That is the day
this ham will tear up his
license. Even the opening of all
CW subbands would not pre-
vent this. Developing 13 wpm or
more in CW is not that difficult,
and, once a ham reaches it,
most enjoy CW contacts im-
mensely. When the QRM be-
comes completely unbearable
at some time in the future, the
logical move would be to nar-
row down the phone bands and
increase the CW spectrum
such as we had when the entire
40 meter band was CW only. In
this way, ham radio will con-
tinue successfully— especially
with the terrific new CW filters
on the market,
Wayne, despite the mistakes
of the ARRL, some of your
counter-proposals are really
weird J Not all, but some. Lay
off the ARRL, but continue your
suggestions, if you desire.
John B. Broughton AD4I
Charleston SO
SEMANTICS
The recent article, "New Life
for Double Sideband?'*, de-
serves some comment. This ar-
ticle was in the August, 1978,
issue of 73.
First of all, the author is
engaging in semantic exer-
cises when he says that the car-
rier of an AM signal is not
changed by the modulating
process. It is true, of course,
that mathematical analysts
and a spectrum analyzer will
show that the carrier is un-
changed when modulation oc-
curs. Nevertheless, examina-
tion of the modulated wave on
an oscilloscope clearly shows
that the amplitude of the out-
put wave does vary with the
audio input. Whether or not you
call that the carrier or not is up
to the reader, but amplitude
variation of the output certainly
does occur. Similarly^ in FM,
the frequency of the output
wave certainly varies, white the
actual carrier frequency itself
remains constant, and varies m
amplitude. Again, the whole
thing depends upon the defini-
tion of certain terms. In my
view, the original 1976 article
by KllOon this subject created
more confusion than it cleared
up.
Similar semantic problems
occur in the author's discus-
sion about the detection of
DSB. Most authors of texts in
communications theory use
the terms ''synchronous, prod-
uct, and coherent" to mean the
same thing in describing detec-
tors, Also, the author of the arti-
cle in question says that a prod-
uct detector only works with
SSB. This just isn't true. Both
theory and practice prove that a
good product detector works
well on AM, and I have used my
product detector for years to
pick up AM. Actually, a good
product detector wili dig AM
out of the noise when a regular
envelope detector won't do the
job. Also, a simple product
detector wiU work on DSB, and
most authorities agree that
understandable speech will
come out of such a detector
even if the inserted carrier Is as
much as 30 Hz away from the
proper value. Actually, the car-
rier can be derived from a DSB
signal by a process of squaring,
filtering and frequency divi-
sion, without use of the PLL,
aithough the PLL is probably
the best method.
In another word error, the
author says that an AM detec-
tor is nothing but a mixer. This
is wrong, since to mix some-
thing you need at least two in-
puts, and an ordinary AM detec-
tor has only one input. Here
again, the meaning of words Is
involved.
At least five stereo AM
systems have been proposed,
each w^th its own advantages
and disadvantages. Whether or
not these will prove to be sue-
cessful depends on many
economic and technical fac-
tors, as the author points out,
James N, Thurston W4PPB
Clemson SC
COMMUNICASTIISfG
Just as early experimental
work performed by amateur
radio operators evolved into the
broadcasting Industry, so, too,
may a new service evolve called
"communicasting/' Based on
experience from amateur radio
repeater operation, a petition
was filed In January, 1977. by
WA2RPC of the Center for Ad-
vanced Study In Education of
the Graduate School of CUNY
with W2KPQ for a new "Com-
munity Educational Radio Fixed
Service" (RM-2846K This semoe
would employ the communl-
casting concept.
Commu nicest ing utilizes a
low-power community repeater
station which can transmit
audio and video signals a
distance of thirty miles or more
from a high antenna. Signals
can input the repeater from
many parts of the community
and the output can be transmit-
ted on an unused UHF TV chan-
nel for anyone to receive. The
petitioners and others filing
comments had additionally re-
quested that these low-power
facilities be exempted from
conforming to rigid broadcast
standards in order to minimize
costs.
In a recent "Memorandum
Opinion and Order"' on RM-
2846, the FCC praised the com-
municasting concept and
made it part of a broad 'Inquiry
into the Future Role of Low-
Power Television Broadcasting
and Television Translators in
the National Telecommunica-
tions System" (Notice of In-
quiry in BC Docket No, 78-253),
The FCC stated that, "The peti-
tion and comments by others
Continued ort page 102
15
RTTY Loop
KEtBOARD
n
Marc L Leavey, M.D. WA3AJR
4006 Winfm Road
flandanstDwn MD 27133
How did the old song go,
"Letlers, we get letters . . /*?
Well, so do I, and this month I'll
dip into the malibag and see
what l<fnd of items are brought
forth.
Chris Sheridan, of Yonkers,
New Yorit, sends aiong a lape
and notes that the printing on
the tape shifts from letters to
figures, but that the transmitted
print appears correct. In order
to diagnose this probSem, you
must be able to read the perfo-
rations directly on the punched
tape. Teletype* has been nice
and standardized the format in
which the tape Is punched.
Looking at the tape from the
top, perforations are for bit 1,
bit 2, sprocket, bit 3, bit 4, and
bit 5. Furthermore, typing reper-
forators put the typed character
six places behind the punched
representation. Looking at the
tape that was sent (I'm sorry
that there is no way to repro-
duce it for publication), the
printing reads: "WEL 8 >))3rS\
Looking at the perforations,
one sees that what should have
been the second "L*' of
"WELL/' 01001 binary, has
been changed to 11011, pre-
sumably by a noise pulse. This
is the code for FIGURES and
was responsible for the shift in
case on the tape. I assume that
your page printer Is equipped
with the ^'downshift on space"
feature that returns the car-
riage to LETTERS after a space.
Thus, the space after the
"WEL" would have returned
printing to the normal mode*
Chris also asks three ques-
tions echoed by many other
hams, with detaiisonly slightly
changed. He wants to know:
1 Do you recommend the
Kenwood (he has the TS-520) or,
to you, which is the best re-
ceiver/transmitter to use for
RTTY?
2. Is the HAL ST-5 good, or
should I try for a better unit?
3. Do you have any recom-
mendations for a linear?
Being of a conservative and
frugal nature, the answer to
your first question, to me at
leasts is obvious. If you have a
station that works on SSB or
GW and you can get it on RTTY,
lise itl There probably Is no
"best" RTTY rig any more than
there is a "best" SSB rig or
"best'* two meter FM transceiv-
er, if there were one clearly su-
perior rig, it would quickly
eclipse all others on the market.
The presence of variety pro-
vides for an Individual's taste,
and what is great for you may
be rotten for me, and vice versa.
Similarly, to those of you using
Inexpensive demodulators,
such as the HAL ST-5 or Fiesher
170» as long as they perform
within your expectations, use
them! It will become painfully
obvious when you try to do
more than these otherwise fine
units can do. There is no reason
to discard a perfectly good
piece of equipment merely be-
cause it does not meet some-
one's arbitrary description of
"the best." I'm going to punt on
the linear question. I don't use
one myself, but 1 guess iikeany-
Ihing else, any clean linear that
can be run key-down, all right
with decreased specs, is fine.
Get what you can afford that
will make you happy, i hope
that kind of puts the philosophy
of equipment procurement into
the proper perspective.
While irs not strictly RTTY,
I'm a sucker for DX requests,
and from a fellow physician, I
find it hard to refuse. P. P.
Kurlan, IVl.D. VU2PP, needs
help in setting up an SSTV rig In
India. He notes that he is par-
ticularly Interested in an Atlas
21 OX or equivalent, and some-
thing on the order of a Robot
400 converter. Anyone who can
help is invited to write him at:
Dr. P. P. Kurian fWBBS, MD,
Kelachandra Medical Centre,
Chingavanam-esessip Tf. Res.
396, Hosp. 334, Kottayam Dt.
Kerala, S. India,
While we're on the subject of
help, all you whale lovers may
be interested in a request from
the Greenpeace Foundation of
America. They need help in get-
ting an L015G Intelex Systems
teleprinter on 80 wpm. Richard
Ham Help
Where can I obtain a con-
tinuity tester that produces an
audible tone which changes
with resistance? I am presently
using a bell taped to a battery,
but of course this does not pro-
vide the information a variable
tone would.
What I had In mind was
something like a conventional
VOM, but with a small speaker
to give an audio clue as to what
the needle was doing.
Roger Deran
21 Betty Drive
Santa Barbara CA 93105
^
I
isns
"shift
POT'
3€K
m
1
001
^h
V TO TDI
^ tCli/AII CRYSTAL)
15359
0 047
^Y
Ih
IK
Z201I
—*M^ —
i
t*jPfHll#
9V
Fig. 7. FT-101&FSK.
Dillman N6VS notes the ma-
chine was made by Standard
Elektrik Lorenz, AG. Write him
at 240 Fort Mason, San Fran-
cisco, CA 94123, If you can help.
The whale will thank you, I'm
sure.
For those of you within the
sphere of influence of Harris-
burg, Pennsylvania, I have a
note here from Bob Marzarl
WA3AVX about the WR3AC0
RTTY repeater. It seems as
though the machine has just
had its second birthday, and
the "parents" celebrated by
equipping It with a new ma-
chine. With a Super Station-
master at 1600 feet above sea
level atop Blue f^ountain, and
25 W erp, the signal covers the
surrounding area well. Digital
input and output is provided by
a system built by local hams.
Bob tells me that they are plan-
ning a link with the Eaglevilte,
Pennsylvania, repeater, north-
west of Philadelphia. This
sounds like a super idea, and
with the possibility of ASCII
lingering as of this writing,
RTTY repeaters could become
the first step to turning any
RTTY station into a computer
terminal.
Somehow, It wouldn't seem
right to have a column without
at least one diagram. This
month*s is provided by Dick
Beagell WDeCEB. Dick notes
that by carefully followmg the
directions given \n the manual
for the Yaesu FT-101B, RTTY
could be generated. Only one
problem: It was upside downl
Fig. 1 is the circuit Dick came
up with. He notes that, as in
many other keyer circuits, the
keying contacts must be "dry,"
that is, outside of the loop. This
means that in order to get local
copy while transmitting^ usual-
ly a good idea unless you are a
perfect speller, you should
either use a polar relay to key
the transmitter, or a magnetic
reed relay, as described here
several months ago. Dick says
that adjusting TC4 and the shift
pot should allow UO-Hz shift
without any problems. He built
his on a small terminal strip
and mounted it to the **FIXED
XTAL" board on top of the VFO.
Does anyone know what ever
happened to the RTTY Journaf
and the New Jersey Green
Keys*^ Several readers have
written to say that they cannot
get mail to these publications
and wonder if they still exist, I
don't know, myself. Do any of
you?
Many, many, many readers
have asked me a variation of
the 'Where can I buy a frammis
zacher?" question so, some-
what against my better judg-
ment, I have decided to pass
along that information about
RTTY sources thai crosses my
desk. Van W2DLT runs a joint
known as Teletypewriter Com-
munications Specialists, They
sell and rent just about any-
thing in Teletype, Baudot, Mur-
ray, ASCII, Of what have you.
See their ad in 73 or Kilobaud,
or drop them a note at 550
Springfield Avenue, Berkeley
Heights NJ 07922. Another out-
fit, Typetronics, reachable at
Box 8873, Ft. Lauderdale FL
33310, sends along an eight-
page list of equipment avail-
able. It appears they have ma-
chines, parts and accessories
for Teletype and Kleinschmldt
machines. I'm sure they would
be happy to send you a list, tool
A tip of the hat to Bill Bennett
K3TNM, Bill RIcharz WA4VAF,
and Ric Cooney WB3DJV, all of
whom have let me know that
the RTTY receiving program
published here in July is up and
running at their stations. In an-
swer to their, and others', ques-
tions, modular sending and
stunt-box programs are under
development, and will be pub-
lished as soon as I am 100%
convinced that they are bug-
free- For those still having prob-
lems with that program, the one
bug that creeps up with fast ter-
minals has been patched, and
the program should work with
any terminal of 300 baud or
faster. The updated source last-
ing (Ver. 3.1) Is still available for
an SASE and one dollar to
cover copying costs.
Other hams have let me know
there is a wide range of equip-
ment in use out there* from the
most elementary to highly-sa-
phisttcated microprocessors.
We've heard from Model 15s
and Digital Group stations. Tm
still compiling a list of what you
send in, and when it looks pre-
sentable, I'll let you all in on
it . . . right here, in RTTY Loop!
16
tit
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Last month, we left you with
quite a cNlf-hanger. We had our
favorite repeater, '*WR what-
ever/* as the target of
maticious interference by a
known, self-confessed, pub-
Itcly^denttfied repeater jam*
mer* We had set some ground
rules which stated that no
violent means could be used to
combat this problem. Also, in
our hypothetical case we had
stated that our ''good guys"
had tried every method of ob-
taining relief from the situation
through the FCC and other
agencies— to no avail- How
would you handle It?
By the way, for those of you
who might doubt that abuse of
our relay systems can manifest
itself to an extent such as
outlined, may I suggest that
you stop here for a moment and
grab your October 73. In it you
will find a story entitled, "The
Ultimate T^Hunt/' by Bob
Thornburg WB6JPi. Read it; it
will tell you quite explicitly the
length to which a person ap*
parently filled with hate toward
either a repeater or repeater
licensee will go in an effort to
make this "hate'* known. The
article breaks down into dollars
and cents the cost that such
wHIful, illegal, and malicious in-
terference can have for us. Hav-
ing lived through the days of
what I term '^Jambox i/' I con-
sider that act and all acts like It
to be a direct assault upon the
integrity of the amateur service
and each one of us. In the end,
no matter what method is used
to handle each individual case,
the cost comes out of our own
collective pockets. Read or
reread "The Ultimate T-Hunt;*
and then continue reading this
article.
The obvious next question Is,
Is there a solution? Is there a
way that amateur radio can rid
Itself of those from within who
seek to destroy us? Last
month, I intimated that such a
way might exist, though I can-
not personalty take credit for
developing it. The vJews you are
about to read are those of an
amateur who is also a very com-
petent attorney. His name is
Joe Merdier N6AHU. Joe came
up through the ranks, so to
speak, starting with CB radio
and moving up to an Advanced
Class license within the short
period of a year. Joe is an avid
tow-band DXer who also en)oys
VHF FM on both 2 meters and
220 MHz.
When we were potting to-
gether the '*First Annual
VHF/UHF Band Planning,
Voluntary Coordination, and
Technical Advances Seminar'*
tor the ARRL National Conven-
tion, we realized that one topic
of extreme importance rarely
covered at these meetings was
dealing with just such cases of
malicious Interference, I knew
how devoted Joe was to trying
to curb this problem, and how
he was trying to use some of
his expertise to help guide
others in this regard. Therefore,
Joe was considered to be an
ideal speaker on the topic. He
was invited to take part In the
seminar; the following Is a
transcription of his talk:
'*The title of this talk is
'Malicious Interference: What
Can You Do?' I would prefer to
title my brief statement, 'Now
That You Have the Tiger by the
Tail, What Do You Do?'
"The jammer poses a unique
problem to the VHF user We
have found through experience
that, in most cases, the FCC or
perhaps other governmental
agencies charged with enforc-
ing the various codes will not
proceed in cases of malicious
interference (to amateur com-
munication). There are ways of
getting around this, I would like
to point out a few suggestions
based on the cases I have been
Involved with, I got involved
because I don't know how to
say no. My friends got involved
and said that they needed help.
When you start dealing with
government agencies, taking
statements, and wanting signed
statements, people become
scared.
"The tracking down and DF*
Ing of a jammer I won't go into,
but it does have legal ramifica-
tions. An incident occurred last
week in Los Angeles, on a very,
very popular repeater. An in-
dividual was caught jamming.
A group of men drove up to his
yard. They (the T-hunters) rang
his door belt; the door belt
came out over the air. The jam*
ming Immediatefy ceased
when the door bell was rung.
Later, the purported jammer
called the repeater owner and
asked him to *call off your
boys.' They had just slashed
the four tires on the jammer's
truck*
"Now, the first reaction that
one might have is: 'That's
good." Somebody's going to get
his comeuppance. However,
that statement gives rise to
many statements legally. Is the
repeater owner responsible for
the acts of his users? Is an
'association* or club that spon-
sors or aids in the upkeep of a
repeater responsible because
someone goes out and slashes
Joe Merdier N6AHU addresses seminar at San Diego,
the tires of someone who has
been ^announced' as being a
iammer? It is my feeling that,
and I am actually doing it for
this one particular repeater; the
best thing is to form a nonprofit
corporation. Any activities
such as DFIng, T^hunting, or
any activities involved In track-
ing down the offenders, releas-
ing information, etcetera, will
be handled through this non-
profit corporation. The purpose
is that we are volunteers. We
are In a hobby for fun. What
happens if you make a state-
ment on the air and a 'guy* says
prove it and sues you? Liable
and slander laws do apply^ and
while most people only
threaten, once in a while you
find someone who will really go
through with It. What happens
when you are sued? Legal fees
are not cheap. The costs of
legal fees, filing fees, deposi-
tion fees— those items add up
quickly. Quite frankly, it can
break an individuaL
"When you get into court,
you never know who is going to
win. In my opinion, it is general-
ly the attorneys. I have to be
qutle frank about it. In my prac-
tice I try to avoid litigation
where possible and will dis-
cuss with clients from a stand-
point of practicality what to do
In a lawsuit. Realty, you get very
few clients who can afford to
fight as a matter of 'principle/
"How do you protect yourself
and the users of your repeater?
For example, I was involved In a
case. There was an announce-
ment made (about the matter). I
should point out that 1 was only
involved actually in coordinat-
ing (the matter), I did not do any
of the DFIng. I played a very
small role In it. In actuality, 1
provided advice. There was a
well-known individual whom we
have decided to call 'W6JAM;
Those of you outside the Los
Angeles area may not have
heard atK}ut this IndividuaL The
most foul mouthed Individual l
have heard. Almost made me
want to take the two meter
radio out of the car. It turned
out to be someone 1 thought
was a friend.
"It created all types of prob-
lems. What do you do if the
federal government refuses to
act in a case such as this? How
can you make an announce*
ment to let other amateurs
know that this individual is the
jammer? How can you make
these statements and do these
things without exposing your-
self to liability? It is my opinion
that a day Is coming when
perhaps the repeater councils
should incorporate as non-
profit corporations so that the
individuals working on behalf
of such repeater councils can
go ahead and make statements
or publish press releases (on
such matters) and not worry
that they as individuals making
such a press release or par-
ticipating in such matters
might be exposed (to individual
liability). You can insure a cor-
poration far more easily than
an individual (against such
liabilities),
^'Another thing It can do is
permit such a corporation to go
into court on such matters,
WESTCARS tried it, but I think
they tried it in state court. I
think that was their downfall.
They should have gone to
federal court; however, that is
second guessing. This Is one
avenue in stopping the prob-
lem,
"What it is going to take Is
some jammer being prosecut-
ed and placed in jail. How do
you get the federal government
Continued orr psge f24
18
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19
DX
Chuck Stuart NSKC
51 W Merwfee Drive
MtK TX 75227
Here it Is December already,
and it appears that good old
Saint Nick wllf be bringing
plenty of exotic DX to the de-
serving. Of course, there is no
need to ask If you Ve been good
or not. That just comes natural-
ly with being a DXer. You are
one of the chosen few,
A couple of months back, In
the October column, we laid
out our ideas and plans for
what we hoped to be able to do
with this column. This included
a monthly DXer profile, lots of
pictures, stories on the latest
DXpedltions, and much more.
Mostly, we want to give you
something we feel has been
missing in the DX columns
presently available — a column
with pictures and stories about
the DXers rather than the OX,
Of course, we will continue to
keep you up to date on "what's
happening/' but it's the per-
sonal side we're looking for.
To do this, we need your
help. Let us hear from you. Tell
us what we are doing right and
what you feel could be done
better. Send pictures of your-
self and your station. Black and
white or color— we can print
either one. Let us know whom
you would like to see in the DX
Profile. We need lots of input
from the readers. The more
Input we receive, the better job
we can do and the better the
column will be. Merry
Christmas.
DX PROFILE
This month's DX Profile is on
one of the best known and most
popular DXers around, Lenny
Mendel K50VC.
Lenny first became interest-
ed in amateur radio while at-
tending a technical vocational
high school in New York City.
He was first licensed while still
a junior in high school in 1945.
but due to the war, he received
no call at that time. By the time
Lenny graduated from high
school, he had earned a com^
merclal radiotelephone license
as well as first and second
class radiotelegraph licenses.
He had also received the call
W20VC.
After a hitch In the Coast
Guard as a radio operator
aboard a Coast Guard cutter
and a short tour as a commer-
cial radio operator on a sea*
going tug, Lenny joined the
sales staff of Harrison Radio in
New York City.
In 1951, Lenny joined the
New York City Police Depart-
ment and became a member of
the Elite Emergency Squad. To-
day this department is known
as SWAT. If there is a better
training ground for the twenty
meter wars, we can't think of
one. In 1971, he retired, com-
pleting twenty years of service.
1972 was not one of Lenny's
best years. He was sued by five
of his neighbors for a cool one
million dollars. They not only
claimed TVI, but charged Lenny
with maliciously operating his
radio and causing severe dam*
age to their health from staying
awake all night waiting for his
Lenny Mendel K50VC, as a member of the New York City Police
Department's Eifte Emergency Squad. He seems to be saying,
'*Whaf do you mean I'm not in the CUpperton tog?"
tower to fall on their heads. The
case made it all the way to the
New York State Supreme Court
before it ended without the
neighbors getting a cent. Lenny
and his wif^ Norrr^a feel that
they never could have made ft
through this period In their lives
without the moral and financial
support provided by their many
friends,
tt was during that time that
Lenny became good friends
with Bud W5WZN and several
other Arkansas DXers. When
the Arkansas DX Association
held a special meeting for
Ahmed AP2AH, Lenny and
Norma decided It would be a
perfect time to visit Arkansas
and meet some of their many
friends in that area. After a
short visit, during which time
they fell in love with Hot
Springs, Lenny and Norma put
their New York house on the
market and moved to Arkansas.
Lenny does admit, though, that
before they signed the papers
on their new home, he set up a
rfg in the driveway just to make
sure he could gel out okay from
that location. Now there Is a
man who has his priorities
straight-
Lenny says that DXing from
Arkansas is just great. You
have a good shot to Asia and
the Pacific, but it gets a little
rough toward Europe. Regard*
less of the conditions, Lenny
has earned 58WAS, 5BDXCC,
Single Band WAZ, and is wait-
ing for cards from 601F6 and
HZ1BX/8Z4 to bring his con-
firmed DXCC total to 319
countries.
Lenny's equipment Includes
a Drake T4XC, R4B, and a Henry
2k linear. Antennas consist of
a KLM 5-element Big Stick on
twenty and a Wilson Duo-
bander for ten and fifteen.
Lenny and his wife Norma, a
native of Wakefield, Mass.,
have three children. Ken is a
doctor at Columbia Presbyter-
ian Hospital in New York City,
Kathy Ann teaches eighth
grade in Humble, Texas, and
the youngest, Jo-Ann, is a
junior at Lake Hamilton High
School who plans to become a
lawyer. None is interested in
amateur radio.
Lenny is one of the real
gentlemen in a highly competi-
tive hobby. The next time you
hear K50VC on the air, give him
a calL You'll be glad you did.
DX NOTEBOOK
Nigeria— 5N2NAS
Ron Veelik WA6LTH forward-
ed a letter he recently received
from Kunle 5N2NAS, secretary
of the Nigerian Amateur Radio
Society, explaining the present
situation concerning amateur
radio operation In Nigeria. In
November, Emergency Regula-
tion Decree No. 24 of 1966 was
lifted. Prior to this, it was un-
lawful to bring amateur radio
equipment into Nigeria and few
if any new licenses were being
issued, especially to foreign-
ers. Now, with the lifting of
Decree No. 24, it is again possi-
ble for foreigners to obtain op-
erating permission. If you are
interested in operating from
Nigeria, write to Oyekunle
Ajayi, Nigerian Amateur Radio
Society, PC Box 2873, Lagos,
Nigefia. Tell them when you are
coming, how long you plan to
be there, and where you will be
staying. If you stay in Apapa or
Lagos, you can receive permis-
sion to operate from the club
station, 5N2NAS. Present club
members are 5N2AAJ, 5N2AAE,
5N2AAK, 5N2AAV, 5N2ESH,
and 5N2NAS. Kunle states that
the NARS members are vitally
interested in W ARC 79, and he
feels that we need well-disci-
plined radio amateurs around
the world to justify the use of
our old and new frequencies.
Sable Island— VGW-211
The ARRL has refused to ac-
cept contacts with VGW-211 for
DXCC credit, citing DXCC rule
number 6 as the reason. Rule
number 6 states that "All con-
tacts must be made with ama-
teur stations working in the
authorized amateur bands or
with other stations licensed to
work amateurs." The discredit-
ed contacts were made August
8th and 9th. Later contacts
made while the station was
signing VE1MTA are accept-
able.
Thailand— HS1AIV
"Chester" XV5AC from a few
years back has returned to
southeast Asia and Is now sign-
fng HS1AIV. Located in
Bangkok, Chester has all the
equipment from XV5AC and
then some. In addition to full
kilowatt amplifiers, he has
stacked ten meter beams,
stacked fifteen meter beams,
two TH6DXXS, and the big Tel-
rex six-element twenty meter
beam. On the lower bands, a
two-element forty meter t>eam
and phased verticals on eighty
do the trick, Chester also
reports room for a 160 meter an-
tenna and plans to do a lot of
operating on the lower bands
this winter. Chester will be
there for a least four years and
has plans for a few molti-multi
contest efforts as soon as he
has the station set up to his
liking and all the bugs worked
out,
Srf Lanka— 4S7
There are presently two list-
type operations involving 487
stations. 4S7EA meets
WB90QU Monday and Wednes-
day on 14247 at 2330Z, QSL to
WB90QU. 4S7JD meets
Continued on p&gi? 74
20
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FfT
ARRL 160 METER CONTEST
Starts: 2200 GMT Friday,
December 1
Ends: 1600 GMT Sunday,
December 3
The annual ARRL 160 Meter
Contest is open to all amateurs
on CW only. Multi-operator
work is permitted and scores
will be listed separately in the
results* but they will not be
eligible for certificates.
EXCHANGE:
RST and ARRL section or
country.
SCORING:
QSOs with amateurs in an
ARRL section count 2 points;
OSOs with amateurs no! in an
ARRL section are worth 5
points. DX-to-DX QSOs do not
count. Multiplier is the total
number of ARRL sections (74),
VE8, and foreign countries
worked.
AWARDS:
CeriHicates will be awarded
for section and non-W/VE coun-
try high scores. Division high
scores will have their section
award endorsed with an appro-
priate seal.
FORMS:
It is suggested that contest
forms be obtained from the
ARRL, 225 Main St., Newington
CT 06111. Checksheets are not
required, but a penalty of 3 ad-
ditional contacts will be made
for each duplicate contact.
These rules were taken from
last year's contest. For com-
pfete rufes, see the November
issue of QST.
VU2 DX CONTEST-GARDEN
CITY CONTEST
Starts: 1200 GMT
Saturday, December 2
Ends: 1159 GMT
Sunday, December 3
The Bangalore ARC and the
VIswesvariah Industrial and
Technological Museum Invite
all amateurs to participate In
the contest this year. Only two
bands are specified, the 20 and
40 meter bands for all contacts,
on CW only! Only one type ot
entry i$ permitted, single
operator. A station may be
worked once on each band;
VUs may contact other VUs.
Valid points can be scored by
contacting stations not In the
contest provided complete RST
exchanges are made and
logged. VU stations will work the
world and vice versal
EXCHANGE:
RST and serial QSO number
of three digits or more.
SCORfNG:
Each completed QSO counts
one point, with the totlowing
multipliers: Power*output
multipliers— 10 Walts and
below = 5; up to 50 Watts = 3;
above 50 Watts = 1. DX multi-
pliers— Asia = 1; Europe, in-
cluding UK, Africa, and Austra-
lia - 2; North and South
America = 3,
Note: For all Islands con-
Dec 1-3
Dec 2-3 •
Dec 2-4
Dec 3
Dec 9*10
Dec 16-17
Dec 24
Jan 1
Jan 6-7
Jan 13-14
Jan 27-28
Jan 28-29
Feb 24-25
ARRL 160 Meter Contest
International Island DX Contest
TOPS CW Contest
VU2 OX Contest
Alexander Volta RTTY DX Contest
Telephone Pioneers QSO Party
EA Contest— Phone
Connecticut QSO Party
Flatland Farmer 10-X QSO Party
ARRL 10 Meter Contest
EA Contest— CW
HA-DX
SOWP Christmas CW QSO Parly
HA 5- WW
ARRL Straight Key Night
ARRL CD Party— Phone
ARRL CD Party— CW
ARRL VHF Sweepstakes
ARRL Simulated Emergency Test
Classic Radio Exchange
French Contest— CW
French Contest — Phone
* = described in last issue*
tacted, for the purpose of
multipliers, the nearest con*
tinent/mainland will be taken
into account. Contacts with
maritime-mobile or aircraft-
mobile stations do not qualify
for DX multipliers. Contacts
with other portable or mobile
stations count as fixed sta-
tions.
ENTRIES AND AWARDS:
AM entries must be post*
marked no later than Dec. 31,
197S, and addressed to:
Bangalore Amateur Radio
Club, VU2ARC, PO Box 5053,
Bangalore, 560 001 India. There
fs no entry fee, and the entry
must be a true copy of the ac-
tual log for the contest period.
Three prizes will be awarded to
the three highest scorers. A
special award will be given by
the Federation of Amateur
Radio Societies of India, All DX
stations who contact 20 or
more VU2 slations will be
issued a ''Garden City Cer-
RESULTS OF THE 1978 FRENCH CONTEST
(Listed by call, number of points^ and number of QSOs)
CANADA
A1
VE3KZ 361030
232
VE2EHF 72896
113
VE2WA 66430
70
VE3BR 21200
53
A3
VE3KZ 516420
349
VE20G 201880
206
VE2AFC 124976
119
TERRE NEUVE
A1
V01AW 105480
130
A3
V01AW 5267
25
U,S,A.
A1
Wi
W1BWS
13108
48
W10PJ
10980
38
W2
A1
W2FAS
100036
118
W2GKZ
62243
96
K2PF
12870
39
N2CM
11284
41
A3
F2YS/W2
183084
162
K2PF
360
8
W3
A1
W3ARK
154700
155
W3HDH
51968
91
N3RL
6720
28
WB3DBI
360
6
A3
N3RL
5500
25
W3MR
9212
35
WB3DBI
40
2
W4
A1
N4NX
138240
144
WB4ENI
10528
38
W4YN
9360
38
AA4RR
22854
60
WB4WHE
120
4
A3
N4NX
5000
2S
WA4L0F
2381
17
W5
A1
K5UR
20898
50
A3
K5RF
1000
10
W8
A1
NSBB
82871
108
W8DS0
11780
38
W8VSK
5940
27
WB8WVW
40
2
A3
K8MN
15640
46
W66TGS
490
7
W9
A1
W90A
56154
lis
K9WA
14490
49
A3
WA9FZ0
34633
69
W9LKt
26789
63
W9TLU
6120
36
W9SS
9090
30
W0
A3
W9CDC
7364
32
2B
I
I
I
if engineering
*t
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High qua (ay power swvilch ai
mode switch on front panel.
MODEL
BAMD
BLC
8LC
8LC
BLC
BLO
BLD
BLD
BLE
BLE
BLE
BLE
10/70
2/70
10/150
30/150
2/60
10/60
1 0/1 20
10/40
2/40
30/BO
10/BO
144
144
144
144
220
220
220
420
420
420
420
MHz
MHz
MHz
MHz
MHz
M Hz
MHz
MH2
MHz
MHz
MHz
^1
e£>
EMISSION
CWFM
CW FM
CW -FM
CW-FM
CWFM
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CW FM
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POWER
INPUT
low
2W
low
30W
2W
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IDW
low
2W
30W
low
POWER
OUTPUT
70W
70W
isow
150W
aow
iOW
120W
40W
40W
dow
sow
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ull hoaUink area mounted
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alymmum extrusion.
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FEATURES
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Broad band design (no tuning).
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90 day limited warranty on
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DIVISION OF BROWNIAN ELECTRONJCS CORP.
320 WATER STREET / BINGHAMTON, N.Y. 13901 / Phone 607-723-9574
tificate." For QRP multiplier, a
signed statement from the
local club's secretary or presi-
dent is mandatory. The rul i ng of
the Contest Committee
(VU2ARCA/U2VTN) is final in any
instance of doubt.
ALEXANDER VOLTA RTTY DX
CONTEST
Starts; 1200 GMT Saturday,
December 2
Ends: 1200 GMT Sunday,
December 3
Two-way RTTY contacts be-
tween stations of the same
country are not valid. All 2-way
RTTY contacts with stations in
one's own zone will count 2
points; those outside one's
own zone count tor points in ac*
cordance with the eKChange
points table. AH 2*way RTTY
contacts made on 7 MHz are
worth double; those on 3,5 or 26
MHz are worth triple points.
Stations may only be worked
once per band. A multiplier of
one is given for each country
contacted on each band. Total
score is total exchange points
times the total number of
multipliers times the total
number of QSOs. Italian bonus
points are added last — 1000
points for each \f\SI\l contact
on aU bands. Note: Each US,
Canadian, and Australian
district wtll be considered a
separate country! Exchange
consists of message number^
RST, and zone. Use one log per
band. Logs must be received
before Jan. 20, 1979, to qualify
(advisable to use air mail). Send
logs and score sheets to: A. V,
RTTY DX Contest Committee,
SSB & RTTY Club, PO Box 144,
22100 Como, Italy.
This contest is open to SWL
RTTYers as well, and the same
rules apply as used for trans-
mitting stations; a separate
results table will be made for
these entries. In addition,
points and positions achieved
in this contest will be valid for
inclusion in the "World RTTY
Championship'' for 1978.
TOPS CW CONTEST
Starts: 1800 Gf^T
Saturday, December 2
Ends: 1800 GMT
Sunday, December 3
General call is "CQ QMF,"
Entry classes for singie-Zmyltl-
operator. Use the 3.5-t0'3.6
MHz band. Look for USA
Novices between 3.7 and 3.75
MHz. Use low end of band for
DX-CW only!
EXCHANGE:
RST and serial number from
001.
SCORING:
Contacts with own country
= 1 point; each call area in
W/K, VE/VO, VK, and UA counts
as a separate country. Con-
tacts with stations in same
continent count 2 points, other
Continued an page 72
RESULTS OF THE
1978 MICHIGAN QSO PARTY
MICH tG AN RESULTS
(Listed by Call, Score and County)
W8PB0
69,040
Macomb
Trophy Winner
K8IF
60.080
Livingston
Certificate
K8R0
48,080
Oakland
Certificate
WBSTRY
36,5M
Wayne
Certificate
K8KA/8
35,259
Osceola
Certificate
KdDD
33,456
St. Clair
Certificate
W8LAQ
31,746
Eaton
Certificate
W8JKU
27,744
Oakland
WD8J0F
20.460
Genesee
Certificate
N8UM
19,992
Washtenaw
Certificate
WB8SLQ
18,312
Macomb
W8QGP
17,580
Hillsdale
Certificate
WD8CQN
17,353
Genesee
WB8YWG
17,100
Shiawassee
Certificate
NaUM/8
16,632
Wayne
WB8MTD
15,080
Jackson
Certificate
WD8ITV
14,699
Macomb
KeSJQ
14,688
Lapeer
Certificate
WD8LRR
14,460
GeneMt
WB8SVI
14,274
Macomb
WD8ITS
13,986
Oakland
WBA7ME
1 3,542
Macomb
K80T
12,660
Saginaw
K8KQJ/8
12,250
Oakland
WD8ECT
11,440
Wayne
WSETH
9,020
Oakland
WD80KM
B.695
Bay
WD8AAE
7,866
Marquette
Trophy— UP
K80AC
6,930
Saginaw
MuUiOp
WASVEB
8,650
Oakland
N8WW
6,480
Macomb
WD80VB
6,407
Macomb
WA8MAM
5,940
Menominee
Multi-Op
N8RW
4,560
Saginaw
woeoKL
4,532
Bay
WB8ZJL
4,176
Macomb
N8HT
3,924
Genesee
WB8BNN
3,478
Van Buren
Certificate
WdHW
3,317
Genesee
N8MK
3,102
Saginaw
WD8IKZ
2,997
Oakland
W8WVU
2,952
Lenawee
Certilicato
WB8AUN
2,800
Macomb
W8WVU|f8
2,376
Cheboygan
Certificate
WB8NXN
2,244
Oakland
WD80LC
943
Genesee
W68LWS
792
Macomb
K8BWC
596
Saginaw
W8YL
532
Lenawee
WA8EFF
496
Macomb
WD80NM
442
Macomb
WA8T0F
300
St. Clair
WD8NNM
72
Macomb
K3KXym8
17,493
6 Cos.
Cefflficale
W8VSK/m8
3,672
4 Cos.
WB8FEZ
2,349
Genesee
Plaque (VHF)
WD8LID
144
Lapeer
VHF
WD8KE0
21
Genesee
VHF
CLUB SCORES
1. L'Anse Creuse ARC~2S6,450 Club Trophy (4th Straight
2. Central Mich. Conlesters— 62,971 Year)
3. Saginaw Valley ARA^36,542
4. Central Mich ARC— 31,746
5. Sawyer ABA— 7,866
(Listed
CAL
CONN.
DEL.
GA,
ILL.
OUT OF STATE RESULTS
by State, Call, and Total OSO Points)
IND.
IOWA
LA.
MD.
MINN.
MO.
NEV.
NJ.
NY.
N.C.
OH.
PA.
Wise.
ONT.
WB6DQR
W1VH
W3JZA
WB4RUA
K9BG
WB9SMU
W9QWM
K9CW
K9GL
K9NN
N9BU
WBiUCP
W5WG
W3BHE
W3PYZ
WAiOlT
WB3JAPW
W7H1
WB2LBV
N2VA
WA2BYX
N2RT
WA20TC
W2EY
WD4BEJ
N4GF
WD8CQR
K&BBH
K3NB
WA3ZAH
W3FVU
W5KL8
N50Q
WB9PVi
K9GDF
WB9KAR
VE30AP
VE3CDK
VE3BR
20
1,84S
640
2,525
5,032
3,86 1
2J83
1,050
192
6,996
1,029
4,026
1,881
6.630
6,400
7,912
1^18
416
5,254
1,098
96
4,366
3,422
980
416
108
2,889
2.714
4,433
779
30
2,002
224
1,771
765
70
8,034
8,000
5J15
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Certificate
Trophy
Trophy
Certificate
28
CT-50 FREQUENCY COUNTER
Outstanding
Performance
at an
Incredible
Price
DESCRIPTION: The CT-50 is a versatile and precision frequency counter whtcfi will measure frequencies to 60 mHz and up
to 600 tnHz with the CT-600 option. Large Scale Integration, CMOS circuitry and solid state display technology have
enabled this counter to match performance found in units selling for over three times as much. Low power consumption
(typically 300-400 ma) makes the CT-50 ideal for portable battery operation. Features of the CT-50 include: large 8 digit LED
dfspiay, RF shielded all metal case, easy pushbutton operation, automatic decimal point, fully socketed IC chips and input
protection to 50 volts to insure against accidental burnout or overload. And, the best feature of alt is the easy assembly.
Clear, step by step instructions guide you to a finished unit you can rely on. Use the order blank betow or call us direct and
order yours today!
SPECiFICATIONS:
Frequency range: 5 Hz to 65 mHz, 600 mHz with CT-600
Resolution: 10 Hz @ 0,1 sec gate, 1 Hz (S; 1 sec gate
Readout: 8 digit. 0.4" high LED, direct readout in mHz
Accuracy: edjustable to 0.5 ppm
Stability; 2.0 ppm over 10^ to 40"* C, temperature compensated
Input: BNC. 1 mogohm/20 pf direct, 50 ohm with GT600
Overload: 50VAC maximum, all modes
Sensitivity: less than 25 mv to 65 mHz, 50-1 50 mv to 600 mHz
Power: 1 tO VAC 5 Watts or 12 VDC g 400 ma
Size: 6" x 4" x2", high quality aluminum case, 2 lbs
ICS: 13 units, all socketed
CT-60Q: 600 mHz prescaler option, fits inside CT-50
CB-1 : Color burst adapter, use with color TV for extreme accuracy
and stabilrty, typically 0.001 ppm
OPTIONS:
CB-1 option: The CT-50 time base may be locked to an external
fraquer^cy standard. The television networks maintain extremely
accurate atomic based frequency standards to maintain color tint on
TV programs. These standards are typically accurate to one part in 10
to the 12- By locking Ihe CT50 to one of these network standards, we
are abfe to get super accuracy. The CB-1 adapter interfaces a standard
color TV receiver to the CT-50 so that one can take advantage of the TV
network frequency standards. The CB-1 requires connection to a color
television for operation.
CT-SOO option r The CT600 prescaler option enables the CT-50 counter
to measure frequencies as high as 600 mHz with sensitivity In the 20 to
150 mv range, depending upon frequency Typical sensitivity at 150
mHz is 25 mv. The CT-600 mounts on the same PC board as the CT-60.
no extra boxes or PC boards are required. The scaler utilizes a state of
IheartECLICchipandtwotransistorpre-amplifier. thuseliminatlng the
need for external pre-amp devices.
rsTiss^ BjIsQlrciiss
Box 4072 Rochester NY 1 461 0 (71 6) 271 ^6487
CT-50, 60 mH^ ^^\mter KH
CT50 WT 60 ttini. counter, wired* tested
CT-600, 600 mHz prescaler of
tor CT-50. add
ACCESSORIES
DC probe, direct input, general purpose type
Hfgfi impedance probe, does not load circuit
Low pass probe, used when measuring audio
High pass probe, reduces low freq picKup
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Color burst adapter, for call bfation. high accuracy
typically 0,001 ppm accuracy, stability
29,9^
$12.95
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Ramsey Electronics
Box 4072 716-271-6487
Rochester, NY 14610 .^lU
7S
VSA
Ktf I «'»vni;c
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Shipping, bandftng, insurance
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Total
$5.00
Name.
Address.
I City.
( — --
^tate.
^ip.
A DXer's
Dream Vacation
try sunny Montserrat
Aim Adfer WB6JPZ
2500 Gran vilie
iQsAngeiesCA 90064
It was another typical
pileup on twenty meters:
lots of stations blasting
away at the rare one, hop-
ing for that all-important
signal report which sig*
Arrival at the Moritserrat airport: Stuart Sokolm W6M}E, left; Ruby Bramble VP2MCB,
center; Alar) Adler WB6IPZ, right
nifies another successful
try. But this time we were
at the other end and the
hundreds of calls were for
us. All we could do after it
was over was grin at each
other at the thrill of for
once being the sought-
after instead of the
seekers. We were, for eight
days, VP2M1E, We had
been lifted out of the
anonymity of our previous
existence as Alan Adler
WB6JPZ and Stuart Sokch
lin W6M)E. For once in our
careers as ham radio op-
erators, we were DX.
The idea for our expedi-
tion really started more as
a dream or wish rather than
a carefully planned and
well thought-out expe-
dition. After suffering
through numerous DX pile-
ups, we started daydream-
ing about how nice it
would be to go on a DX-
pedition ourselves. Lack-
ing tremendous financial
resources and a great deal
of time, we resigned our-
selves to more daydream-
30
ing. We stiti hoped one day
to strike out on a trip to
some exotic DX location
— possibly some island.
Our opportunity came
sooner than we expected.
A small ad in the back of
a ham periodical told of a
house which was available
for rent complete with
tower, quad, and linear
amplifier The house was
located on a smalt obscure
island in the Caribbean,
British West Indies. The
island was Montserrat, of
which we knew absolutely
nothing. Everybody we
asked about the island also
knew nothing about its
location or geographical
layout. Being intrigued by
the mystery surrounding
the island, we began to in-
vestigate the possibility
that this mfght be a place
for our first expedition. We
inquired further about how
to get to the island and
where it was actually
located. Travel agencies
were no help and we had to
do the research on our
own. After calling nu-
merous airlines, we finally
found a way to get down to
the island, which involved
the use of three separate
flights. After careful
research, we decided that
this was the opportunity
for which we had been
searching. Both Stu and I
could afford the trip to the
island, and we would be
able to operate without the
hassle of taking along an
antenna system or linear.
The problem of a rig was
solved by using my FT-
101B. an excellent rig for
traveling. We decided that
this was the place to try our
hand at being DXpedi-
tioners.
Immediately we wrote
to the owner of the house
to inquire about the avail-
ability and cost of rental
and the procedure for ob-
taining a license. We
received a detailed reply
from Doc Beverstein
VP2MZ, who was delighted
with our interest in
operating from the island
Mountain view on the way to P/ymouth^ showing typical scenery of the island.
and arranged for us to stay
in the house from Septem-
ber 24, 1977, to October 2,
1977. The rent was very rea-
sonable, well below that of
a similar stay in the local
hotel Once the reserva-
tions were finalized, we set
out to organize our forth-
coming trip. First, a letter
was sent to one of the hams
on Montserrat to obtain a
license. Here we were
helped by Ruby Bramble
VP2MGB, She was able to
apply for our license under
standard reciprocal agree-
ments, and would be
waiting at the airport to
help us through customs.
We set out from Los
Angeles on September 23,
leaving for New York at
10:00 pm Los Angeles time.
Upon arrival at Kennedy
International Airport, we
had to wait six hours for
Operating position. Alan Adler, left, and Stuart Sokolin, right
31
MONTSERRAT
BRITISH WEST INDIES
OSO WITH
2 WAY SSB-CW
MONTH
SEPT,
OCT.
DAY
I mm
YEAR
1977
RST
BAND
3.5 - 7
14-21 -28
EQUIP: FT101B-SB200-2EL QUAD - SLOPER
L
OSL VIA W6EL
73^3
Stu & Al
W6MJE: Stuart Sokolin
WB5JPZ: Alan Adier
our connecting flight to
Antigua. After arriving in
Antigua on a very hot and
humid afternoon, we had
to wait another four hours
for our flight to Montser-
rat. On our last flight, we
crowded into a hot,
steamy, ancient DC'3
somewhat reminiscent of a
Mexican bus ride, and took
off (thankfully) for Mont-
Sample Montserrat QSL card
serrat. Fifteen minutes
later, we stumbled off the
plane, clutching our equip-
ment, and headed for
customs. We encountered
little difficulty at the
customs office once Ruby
presented the officer with
our Montserrat amateur
license.
Our route to the house
was short but strewn with
holes, ruts, and other
obstacles such as stray
cows. The house itself was
isolated and surrounded by
thick undergrowth topped
with beautiful flowers,
making a very picturesque
scene. The inside of the
house was very nice, with a
separate living room, kitch-
enette, and two bedrooms.
The ham station was in one
View of operating area. Equipment shown: Yaesu fT-101B, FV-101B, and Heath SB-200
linear.
of the bedrooms, which
had an unobstructed view
of the ocean. The house
was on a hill overlooking
the ocean, and the trade
winds from the Caribbean
kept the whole house cool.
Both Stu and 1 were over-
whelmed by our surround-
ings. Seeing it all, we decid-
ed that life as a DXer might
not be so bad after alL
Eager to set up, we piled
the equipment onto a table
and started to hook up the
maze of wires necessary
for our operation. Our
equipment consisted of my
Yaesu FT-101 B transceiver,
the FV-IOIB external vfo,
the SB-200 linear amplifier,
and our portable cassette
recorder. Our antennas
were a Hy-Cam quad on a
70-foot tower and sloping
dipoles for 80 and 40
meters. We had a first-rate
island setup.
After an hour of setting
up equipment and fixing the
sloping dipoles, knocked
over by a recent tropical
storm, we were ready to
make our appearance on
the air. In order to generate
maximum exposure, we
started on 20 meters with
the quad pointed toward
the United States. The
response was astounding.
Within seconds of starting
operations, we had a tre-
mendous pileup of state*
side hams. To be on the
other end of a pileup this
size was the most exciting
ham radio operation that
either Stu or I had ever ex-
perienced. It was instant
popularity I — and quite dif-
ferent than being just
another California station.
Fortunately, both of us had
planned, months in ad-
vance, the techniques we
would use in handling large
pileups, and soon we were
handling the callers
smoothly and quickly.
In order to assure
everybody an equal
chance of contacting us,
we decided to keep the ex-
changes to a minimum. For
example, during our heavi-
32
est pileups we would only
ask for callsign and signal
report We would not stand
by for anyone's friends at
any time, so as to be fair to
all hams, and we would not
use lists of any kind when
dealing with the pileups. In
order to give areas of
poorer propagation a
chance, we took periodic
standbys to listen for the
weaker stations. The over-
all operating manners of
the stateside stations in
pileups were quite com-
mendable. We had very lit-
tle deliberate interference.
The hams would stand by
while we were in contact
with each station, and
there was very little tail-
ending. When we asked for
standbys to the areas with
poorer propagation, we got
good cooperation and min-
imum QRM. Score an "ex-
cellent" for American
amateurs in our pileups.
The European pileups
were much harder to con-
trol The European hams
usually did not stand by
while we contacted a sta-
tion, and the interference
was much greater. These
reactions may have been a
result of the language bar-
rier or of a lack of ex-
perience in large pileups.
Still, we had many good
contacts into the European
area.
After our hectic opening
night of operation, we
finally realized that we
would need some supplies
if we were going to survive
a week on the island, so we
set out on a mini-ex-
pedition into Plymouth,
the one and only town on
the island. We piled into
our small taxi and raced
over mountainous roads
past beautiful hills and
lush green valleys to the
main market. Driving in
Montserrat is a real ex-
perience in survival First,
they drive on the opposite
side of the road, as in
England. Second, the roads
are narrow and rugged,
with lots of blind curves
This is a view of the town square in Plymouth.
and thousand-foot drop-
offs. Third, everyone drives
as if he were trying to win
the Monaco Grand Prix. It's
very exciting to see if you
can make it to town and
back without an accident
with another driver or with
one of the many large cows
wandering about. Planning
on a long siege at the radio,
we stockpiled such neces-
sities as cases of soft drinks
(at an amazingly low 10<C
per bottle), packs of candy
bars, eggs, Heineken beers,
and other essential foods
needed for good health.
After loading the car with
munchies, we decided to
walk around town and do
some sightseeing. The
village was very quaint and
all the people were quite
friendly- Upon our return
to the house, we decided to
see if there was any activi-
ty yet on 15 or 10 meters.
The pileups on 20
meters seemed like a
picnic compared to the
response we got on 15
meters. We were inun-
dated with calls from all
area.^ of the United
States as well as Canada,
and with an equal
number of calls from the
European stations. We
had no idea where to
point the quad first,
since wherever we aimed
the antenna we were bar-
raged with calls. Stu and
I took turns operating
and logging, trying to
work as many stations as
possible, but we could
not handle all of the
response.
We finally had to reluc-
tantly leave 15 meters to
take advantage of an
opening on 10 meters. 1
think half of the world
followed us to 10 meters.
If you think 10 meters is a
dead band, just listen to
a DX station give one CQ.
I believe we attracted
every ham within 6,000
miles. We were working
stations at the rate of
three per minute until a
sudden power failure on
the island took us off the
air. After the power had
been restored, we checked
the band but found
that the propagation had
gone down considerably.
Taking a quick count of
our brief 10 meter debut,
we found that we had
contacted over 200 sta-
tions in about one hour.
We had also contacted
over 300 stations on 15
for our first try on that
band.
Almost collapsing from
exhaustion, we stumbled
out to our patio overlook-
ing the Caribbean and
revived our spirits with
several cold drinks from
our spacious, well-stocked
refrigerator. The life of a
DXer can truly be grueling,
we thought, as we relaxed
on the front porch, enjoy-
ing the cool trade winds.
Then, gathering courage,
we went back into the
shack and looked at the log
to see how many extra QSL
cards we would have to fill
out for our moment of
glory. Sobered by the
thought of increased writ-
ing, we decided to concen-
trate on our two expedition
goals: first, to obtain
enough countries for
DXCC; second, to work all
states.
Shunning massive pile-
ups for the moment, no
matter how ego-gratifying,
we exerted all our efforts
toward obtaining a max-
imum country total We
tried 40 meters for night-
time DX, but found the
band cluttered by broad-
cast stations, making com-
munications impossible.
33
View of 70-foot tower and Hy^Ca/n quad. This was shot on
the approach to the house.
Our 80 meter nighttime
operation proved much
more successful and we
were able to work several
of the European countries.
We were also able to spend
some time in the Russian
portion of the 80 meter
band, working many of the
Russian stations which
could not come up to the
regular DX area of the
band. During the daytime
we concentrated primarily
on 15 and 10 meters, get-
ting excellent propagation
into the Mideast Asia, and
Oceania. Longpath to
these areas was also quite
effective and was the only
way we were able to con-
tact stations in the Asian
zones.
Being able to operate in
the foreign band, a priv-
ilege denied to us in the
United States, helped im-
mensely in contacting new
countries. We were able to
avoid much of the QRM
and congestion of the
American band and were
also able to contact sta-
tions which operate pri-
marily in the foreign band.
Split operation also was
made more efficient by our
ability to listen in the DX
portion of the American
band but transmit below
the band edge. Operating
in this portion of the band
was an experience we real-
ly miss, now that we are
back in the United States.
We were surprised to
find that, at the end, when
all was totalled, we had not
only met our goal of 100
countries, but had exceed-
ed it by a large margin. The
total country count fin-
ished at 143 worked, in-
cluding all continents. We
had also obtained contacts
with alt 50 states, the most
difficult being Alaska and
the last being South
Dakota. Lest anyone think
that all we did was hunt for
specific states and coun-
tries, let me add that in our
eight days of operation, we
contacted more than 3,300
stations.
After eight days of
operation, we reluctantly
packed for our trip back to
California. We were sad to
leave the island. Though
we would not miss the
giant bugs that attacked us
every night, nor the sugar
ants that competed with us
fof food, we would miss
the beautiful weather, the
friendly people, the help
and support of local hams,
and, most of all, the
notoriety of being a
sought-after DX station.
We were about to be
transformed back from
pileup-makers into pileup*
seekers. Stu and I were
ready to stay indefinitely,
but we had no choice
because the house no
longer belonged to us. A
new occupant was eagerly
waiting for us to leave so
that he could taste the ac-
tion that we had enjoyed.
The weather was perfect as
we left for Antigua to meet
our connecting flight back
to New York,
As luck would have it,
we arrived in Antigua just
in time to watch our con-
necting flight take off for
New York, which started
off a whole chain of missed
flights, so we had plenty of
time to sit around airports
and reflect on the ex-
periences of our first ex-
pedition. We listened quite
a bit to cassette tapes that
we made of our operation
and enjoyed reliving the
pileups. Both of us agreed
that it was well worth the
trip to Montserrat to under-
stand first-hand the work-
ings of a DXpedition. The
experience gained on the
receiving end of a big
pileup is invaluable. It
helps one's discipline in
operating procedures, and
it makes one appreciate
the difficult time that DX
stations have in sorting out
the numerous calls which
seem to blend into one
continuous buzz.
When we arrived back in
Los Angefes, our QSL
manager, Sheldon Shallon
W6EL, presented us with
the first of a number of
large shopping bags full of
QSL cards. After looking
through hundreds of cards
sent for our VP2M) E opera-
tion, we have learned what
will expedite a return card
and what will stow a card
down. For example, it is
surprising the number of
people who send cards
with local time indicated,
instead of the univeralty
accepted GMT. A DX sta-
tion, which has no idea of
what COST or MDST
means, will simply throw
away a card not in GMT,
and the poor ham who
worked so hard in that
pileup will never get his
card. We've received cards
which have been an hour or
more off of the correct
time, and some have come
through with no time in-
dicated at all. Also, people
who send cards to a QSL
manager with no SASE, ex-
pecting to get a card back
immediately, will be lucky
to get a card back through
the bureau in a year, if at
all. Some cards came with
the wrong date, and with a
log containing 3,300 con-
tacts, it is impossible to
spend time looking for that
contact. Above all, make
sure that every DX card
you send is in GMT with
the correct date and time,
and is legibly written.
Luckily, however, most of
the cards sent to us were
done properly, so we were
able to locate them quick-
ly in the log and send them
out in a reasonable period
of time.
Both Stu and I have
agreed that the expense
and time involved in an ex-
pedition such as ours is
well worth it, and we feel
that any ham who has the
opportunity to go on an ex-
pedition should not hes-
itate One need not go to
the rarest spots of the
world to enjoy the excite-
ment of being a DX station.
We were neither the first
nor the last of the stations
visiting Montserrat, but
every ham who has been
there has enjoyed the ex-
citement of being on the
other end of the pileups
and there is plenty of ac-
tion on all bands. Other
islands could offer the
same opportunities. DX-
peditioning is a unique ex*
perience which can be ap-
preciated only by those
who have tried it ■
34
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35
D.L. Dobbs K8NQN
6612 Pleasant Street
Cmcinnati OH 45227
Close Encounters
•a
the eyes of Texans are upon them
Something strange was
moving up there!
Across the glittering star
fields of a moonless Texas
night it crept, a small
orange light, pulsating
slightly and growing
brighter. Abruptly, it
changed direction. Red-
dish now, it proceeded at
right angles to its former
course, away from the
smudge of light on the
horizon that marked a dis-
tant city.
A flight controller
hunched intently over his
radarscope. Its eerie glow
illuminated an expression
of amazed disbelief, A
silent whistle escaped from
his pursed lips. An 80"^ turn
at 16,000 mph and out of
range already? Involuntari-
ly, his throat muscles
tensed to speak to the pilot
of the only plane on the
scope, then relaxed. Who
would believe him? Prob-
ably an equipment
malfunction, he thought.
Yet stories told by old-
timers, stories at which he
had scoffed, began to filter
into his mind.
Much lower now, the ob-
ject skimmed slowly over
an area of rough terrain A
lone car probed the dark
county road with high
beams, Nearing the crest of
a hilL it switched to low as
a glare showed someone
was coming. The beer net
on 34/94 was pleasant com-
pany. Suddenly there was
only dead silence. Worse
yet, the engine and
headlights had quit at the
same moment!
Too busy braking to
question the source, the
driver was thankful for the
light as he brought the car
to a stop on the berm. But
now the approaching blaze
looked like a jet-propelled
magnesium flare. )ust as it
seemed that it must smash
right into the car, it was up
and over and off into the
sky behind. And a ham sat
quietly, shaking for five
minutes before realizing
that the engine was run*
ning. the headlights were
on, and the repeater was
chattering away as though
nothing had happened.
"What was thatV was still
his only thought.
At that moment, not far
away, as it had all day,
every day for months, a
unique laboratory waited
to answer that question
Near the very limit of their
sensitivity, recording in-
struments deviated slightly
from the norms of their
tireless monitoring. Inside
a low building, pale by
starlight against the dark
hillside, electrons surged
through microcircuitry. A
minicomputer swiftly ex-
ecuted its intricate series
of commands. An alarm
shrilled, alerting duty per-
sonnel. Quickly all posts
were manned, and the
sophisticated technology
of the only known scien-
tific facility in the world
dedicated solely to UFO
research was ready for
what might come.
Still adjusting headsets,
observers manning three
phototheodolites at widely
separated locations on the
40CI-acre site scanned the
stars for one that moved,
waiting for instructions.
They were not long in com-
ing, "Magnetic anomaly,
270 degrees, increasing in
intensity. Stand by/' Inside
the laboratory, the director
studied the endless white
tongue of paper extruding
slowly from the chart
recorder. Eight fine lines
were being penned on it.
measuring the output of
various sensors. Periodic
blips indicated time signals
being received on 60 kHz
from WWVB. Two of the
channels were now show-
ing deviation well above
their baselines. Attention
shifted expectantly to the
color video terminal.
From high atop a tower
rising into the darkness
above a nearby building,
powerful radar pulses were
sweeping a 12-mile radius.
For several rotations there
was no unusual return.
Xhen, ''Radar lock-onl'' As
coordinates of the UFO
were relayed to the field
observers, excited cries
doubled in the headsets.
''Got it! Orange lenticular
object moving in fast."
All three photo-
theodolites were now
tracking the obiect. Each
operator concentrated on
keeping the image of the
UFO centered on an \l-
luminated spot in his aim*
ing scope, while shaft en-
coders on the pan-and'tilt
heads of the telescopic
cameras were feeding
coordinates into the com-
puter. At the same time
photographic evidence
was being collected, data
sampled from each of the
three locations every few
seconds was being pro-
cessed into a video display.
The UFO's path was seen
superimposed over an im-
36
Photo A. Laser beam made visible by water vapor refraction pierces the night from the UFO light-pulse experiment ap-
paratus at the Laboratory for Instrumented UFO Research near Austin, Texas. Capable of transmitting up to 2.5 million
bits of response-test data per second, this red-tight laser device can also be used to measure UFO distance and test the
hypothesis that light beams may be bent in the vicinity of some UFOs.
age of the area beoeath it.
Actual distance readings
were being printed out for
permanent record.
Busy as it was, though,
the computer was also per-
forming a number of other
vital functions. As the
vidicon operator focused
on the approaching UFO, it
measured the arc subtend-
ed by the image and com-
puted the size of the ob-
ject. It also computed the
visibility radius of the ob-
ject, and retrieved the
names and phone numbers
of ARGUS volunteers who
should be able to see it
Several telephone lines
were being pulsed with the
dual tones so familiar to
autopatch users, and
sleepy voices began
answering phones shrilling
on bedside stands miles
away. As each answered,
the name and phone
number was printed out
and the volunteer heard,
''This is an Operation
ARCUS alert! Please do as
you were instructed/'
Suddenly wide awake,
the observers hastily
pulled on clothes, jammed
feet into shoes, and
grabbed binoculars and
cameras on the run. This
night they were not to be
disappointed. Here was
UFO event-sharing on a
silver platter, in contrast to
the ordeals suffered by
our friends in "Close En-
counters'' on the silver
screen.
Unlike the movie, the
scenario we have imagined
is hardly fantasy. This
laboratory actually exists.
At this very moment,
whatever the time, its
equipment is scanning the
sky, waiting for the real
thing to happen. This is
where history may be
made— Project Starlight
International, or PSK
In the rattlesnake-
infested hill country north-
west of Austin, Texas, ac-
cessible only by four-wheel
drive, lies the 40(>'acre site
of the Laboratory for In-
strumented UFO Research,
a facility unique in the
world. At this remote loca-
tion, field research is con-
ducted for Project Starlight
International, a research
division of the Association
for the Understanding of
Man, which is a nonprofit
educational organization
based in Austin. RSI's pur-
pose? To document scien-
tifically and irrefutably the
existence of UFOs, Ray
Stanford, founder and
managing director, is an
acknowledged expert in
the field of UFO research.
Author of Socorro ''Saucer''
in a Pentagon Pantry, he
conducted a fascinating
and well-documented in-
vestigation of the Socorro,
37
Photo B. PSrs Operation ARGUS radar and radio-frequency monitoring laboratory. With
a radius of 12 miles, this radar unit will provide UFO distance data for Operation
ARGUS, a computer-centered tracking system of highly sophisticated design covering
a range of 472 square mites.
New Mexico, landing of
April 24, 1964. According
to Stanford, there is no
known research facility in
the world dedicated to
UFO investigation which
even approaches the so-
phistication and capability
of PSL
This high-powered re-
search effort is directed by
a professional astronomer.
Dr. Daniel H. Harris, Ph.D.,
from the University of
Arizona. Dr. Harris, some-
thing of a modern pioneer,
is the first scientist to ac-
cept a full-time paid posi-
tion in UFO research. Right
now, final touches are be-
ing completed on the most
sophisticated of the equip-
ment, and the laboratory
will be fully operational.
Much of the equipment is
already scanning Texas
skies twenty-four hours a
day. And a most impressive
array of scientific goodies
it is indeed.
What are the prospects
for irrefutably document-
ing a close encounter?
Much better than you
might think, as witness the
photographs showing only
one of several UFOs
observed at the site. But
wouldn't it be better to go
to the UFOs rather than
hope they appear at one
location? Actually, that
was the historical ap-
proach. During the green
fireball episode, in the
late '40s and early '50s,
teams of investigators for
Project Twinkle rushed
from one area to another
where sightings were being
reported. Invariably, they
arrived too late to see
anything. The UFOs, it
seems, didn't wait around
for them, PS I decided that
it would be more produc-
tive to establish a perma-
nent laboratory with
sophisticated equipment
and man it around the
clock, seven days a week.
The other option is still
open, however. A vital core
of instruments can be
transported on short notice
by four-wheel-drive van to
any location where it might
be needed.
Until now, most UFO
research has been anec-
dotal Witnesses of past
events could be inter-
viewed and second- or
third-hand information
could be correlated. Infre-
quently, a fortuitous
amateur photograph,
usually of very poor quali-
ty, might turn up. Or
perhaps a bit of soil from a
purported landing site
could be secured for
analysis. Immense effort
went into analyzing and
rehashing data of this kind,
and there is a lot of it
UFOCAT, the computer-
ized files associated with
the Center for UFO
Studies, now contains over
60,000 close encounters;
And Ted Bloecher has in-
dexed over 1500 close en-
counters of the third kind,
in which contact with en-
tities was reported.
38
However, there was no way
to study UFOs directly and
scientifically. Like the
weather, lots of people
talked about UFOs, but
nobody did anything about
them — except for the
military, which was busy
trying to shoot them down.
Scientific voices have
cried in the wilderness
almost from the beginning
of the modern UFO era in
World War II, urging
serious Investigation Back
in 1968, the House Com*
mittee on Science and
Astronautics held a hearing
on UFOs. Dr. Carry C.
Henderson, then project
leader on the lunar surface
gravimeter/surveying
system, proposed an im-
plemented ptan to acquire
hard facts about the ex-
istence and nature of
UFOs He even detailed the
instruments which should
be used And Carl Sagan,
an astronomer who is as
outspoken an advocate of
the well-inhabited universe
theory as he is a skeptic
about UFOs, has said that
anyone really interested in
the supposed phenomenon
should use high-quality in-
strumentation to probe its
nature. Finally, someone is
doing just that!
PS I is equipped to study
a broad range of physical
effects which might be
associated with UFOs.
Their objective is to gather
a maximum range of hard
data and to disseminate
this information quickly to
members of the scientific
community. At a local
level, larger numbers of
people, probably including
some hams, will be able to
share in UFO events through
Operation ARGUS,
The Greeks, as usual,
had a word for it. Argus
was a character in Greek
mythology who had eyes
ail over his body to make
him a good watchman. At
the Laboratory for In-
strumented UFO Research,
ARGUS stands for Auto
mated Ringup on Ceo-
located UfO Sightings,
and we have illustrated
how it might work in prac-
tice. But there is a lot more
to scientific UFOIogy than
this,
UFOs have been re-
ported to cause magnetic,
radio-frequency, elec-
trostatic, and gravitational
effects, as well as
temperature changes,
barometric disturbances,
and sounds. PSi's auto-
matic recording equip-
ment therefore includes
three magnetometers and a
gravi meter, as well as a
microbarometer, an elec-
trometer, and a sky camera
activated by magnetom-
eter deviations. An am-
bient microphone records
voice input and audio ef-
fects, white a highly-direc-
tional microphone can
handle distant sounds. The
eight-channeL sensor-
activated chart recorder
displays low-frequency
data up to 150 Hz cor-
related with universal time
from WWVB. Radio-
frequency scanners and
recorders also incor-
porating UTC input cover
the rest of the spectrum-
A computer-interfaced
magnetometer system has
been completed which will
process field-effect data.
Newly-designed sensors
with 60-Hz filters respond
up to 700 Hz and are
oriented in three dimen-
sions. Thus a three-
dimensional video model
of the magnetic field
around a UFO can be
displayed, showing each
component in a different
color. Pulsations or
changes In light emitted by
a UFO can be monitored
by an electronic system
utilizing solid state sensors
having a bandwidth of 10
Ray Stanford, Managing Director
Project Starlight International (PSI)
PO Box 5310
Austin TX 78763
Walter Andrus, Director
Mutual UFO Network (MUFOK)
103 Oldtowne Road
SegulnTX 78155
Dr. J. Allen Hynek, Director
Center for UFO Studies (CUFOS)
924 Chicago Avenue
Evanston IL 60202
WilMam Spaulding, Director
Ground Saucer Watch (GSW)
13238 North 7th Drive
Phoenix AZ 35029
Dr. Dennis W. Hauck^ Director
International UFO Registry (lUFOR)
PO Box 1004
Hammond \H 4e325
James Lorenzen, Director
Aerial Phenomena Research Organization (APRO)
3910 East Kleindale Road
Tucson A2 65712
Table 1. Major UFO research organizations.
MHz.
OZMA and CYCLOPS
are strange-sounding
names for serious projects
funded by the VS. govern-
ment to search for in-
telligent life in space.
Possible communications
from selected stars have
been monitored. SETI,
Search for Intelligent Life,
is an ongoing NASA project
which is developing
designs for a very large
system of antennas and
computers for the purpose
of contacting extrater-
restrial life. Since NASA
scientists are convinced of
the importance of such
endeavors, PSI has not
neglected this aspect of
UFO research. Are UFO in-
telligences, if they exist,
capable of or interested in
exchanging intelligent
communication? To an-
swer this question, a
modulatabfe Liconix 605M
helium-neon laser has been
installed which can
transmit voice, code, or
television signals. Any
modulated light response
which a UFO might make
to the laser signals can be
detected as sound or as a
TV image.
Radio transmissions
other than noise have not
been reported from UFOs.
Disruption of radio trans-
mission and reception, on
the other hand, is frequent-
ly reported. This is why
laser light rather than rf
was chosen for a com-
munication experiment.
According to many
reports, what appear to be
coherent light beams of
various colors have been
projected from UFOs. And
searchlight beams directed
at UFOs have been seen to
bend sharply, due perhaps
NET
DAY
BAND
MH2
UTC
EST
CONTROL
QTH
Saturday
40
7.237
1200
08O0
N1JS
MA
Saturday
75
3.975
1300
0900
WA9ARG
IL
Table 2. MUFON amateur radio SSB nets— weekly.
39
Photo C. An early prototype program dispiay on Operation ARCUS's color video ter-
minal, sbowJng simulated UFO tracking over a computerized topographic map. Tracking
and laboratory instrument data is automatically displayed below the map^
to some field effect or
variations in atmospherrc
densitv- These are phe-
nomena worthy of in-
vestigation for which the
laser equipment could be
used. In addition, the
system can be adapted to
determine the distance of
an object with extreme ac-
curacy using reflected
laser light.
As you might expect,
photographic documenta-
tion is an important aspect
of the laboratory program.
UFOs within range will
find that they are captured
on 35mm moving picture
film A Super-8mm sound
movie camera with a
1-to-12 ratio zoom lens is
also available. From
various stations at the site,
three automatically syn-
chronized 35mm cameras,
one of which is equipped
with a diffraction grating
for spectral studies, record
any UFO event. High-
resolution, close-up im-
ages of objects being
tracked can be obtained
using Schmidt-Cassegrain
telescopes of 2,110mm
and 1,250mm focal
lengths, as well as a
240mm telephoto lens on
the 35mm movie camera.
UFOs have often been
reported to investigate
new or unusual light pat-
terns on the ground. Some
have responded to lights
flashed or directed at
them. For this reason, a
light pattern response ex-
periment has been de-
vised, although it is rarely
used, A hundred-foot cir-
cle consisting of ninety*
one 150-Watt spotlights
contains a single light in its
center Solid-state circuitry
and a microprocessor
make It possible to se-
quence the fights in any
desired pattern, or even to
mimic the light patterns of
a UFO.
K12XBJ, the only known
radar facility in the world
dedicated exclusively to
UFO research, was li-
censed by the FCC on )une
8,1977. Although it is
planned to install a more
effective system for broad-
range sky coverage when
funds permit, the present
Raytheon Model 1700
covers a 12-mile radius
with 360-degree rotation.
Operating on 9375 MHz,
its 7.5 kW pulses can
detect reflective objects
up to 20 degrees above the
horizon.
How big was the UFO?
This easy-sounding ques-
tion is one of the most dif-
ficult to answer accurately
when a sighting has oc-
curred. Was the object
very large and far away, or
was it small but close to
the observer? Few people
run around with optical
range finders in their
pockets, and it is rare that a
UFO passes in front of
some background object
which can provide a
distance reference. At
PSl, however, Operation
ARGUS can determine
distance electronically by
radar Not all UFOs reflect
radar signals, apparently,
but this poses no problem.
Accurate horizontal and
vertical coordinate data
from shaft-encoders on op-
tical tracking equipment
can be triangulated by the
computer to provide ac-
tual distance, horizontal
distance, and altitude. If
the area of an image can
be measured, the size of
the object can then be
computed from the
distance data.
When a UFO is being
tracked, the ARGUS com-
puter has been pro-
grammed to select from its
memory of 472 square
miles of terrain that sector
of a full-color topographic
map over which it deter-
mines the object to be
passing. The path of the
UFO then appears on the
video display superim-
posed over the image of
the terrain. Sequentially-
tracked positions are in-
dicated by successive let-
ters or numbers. The entire
episode, correlated against
UTC, can be retrieved from
computer memory for
later study. Ground ob-
jects over which the UFO
passed or hovered as well
as possible landing sites
will thus be a matter of
record. They can be ex-
amined for evidence later,
if the UFO departs before
a mobile unit can reach
the site.
We've had a look at the
CUS of Operation ARGUS,
which is primarily techno-
logical. The AR, auto-
mated ringup, deals with
people, for it is in this way
that local volunteers can
get involved Ray Stanford
terms this aspect of the
operation "UFO event-
sharing." Here is a concept
of great potential to us as
amateur radio operators,
wherever we may live. As a
movie, "Close Encounters''
was great entertainment
and could even be con-
sidered educational in
some respects. But fan-
tasy aside, what is the ac-
tual status quo with regard
to UFO knowledge at the
40
present time?
To be honest about it,
there is a great diversity of
opinion on the subject.
UFOIogists, many of whom
have been investigating
the phenomenon for thirty
years, present a spectrum
of opinion. Some take the
position that little or
nothing is known concern*
ing the true nature of the
UFO. Official government
interest vanished with the
dissolution of Project
Bluebook and the issue of
the infamous "Condon
Report/' which as much as
denied their existence. On
the other hand, a number
of authorities believe that
the reason for governmen-
tal disinterest, including
the recent refusal of NASA
to reopen the field for in-
vestigation, is that they
already know all about
UFOs. In his book, Situa-
tion Red: The UFO Siege,
Leonard Stringfield builds
a strong circumstantial
case that intact spacecraft
have been recovered from
crash sites, and that ex-
traterrestrial humanoids
have been autopsied. If so,
it now appears unlikely
that military authorities
will voluntarily expose
these facts to public view.
However, a lawsuit filed by
one UFO group against a
government agency under
the Freedom of Informa-
tion Act could produce
evidence of such conceal-
ment.
Between these view*
points, one finds many
theories about the nature
of the UFO. Some
UFOIogists believe that
the phenomena may be
psychic in nature. Others
think UFOs are a mass
neurosis, a psychological
projection from the race
mind, A few like the idea
that they are a control
mechanism, designed to in-
fluence human evolution
in the manner we saw
dramatized in the movie
"2001." Most however,
believe the evidence
points to hardware from
Photo D. Second-generation print of possible UFO which hovered for nearly 10 nninutes
beginning at 8:58 pn} on December 10, 1975. Tri-X film, 5-$econd exposure with 300n}m
f/4 lens. Forty-eight photos were obtained during this event which occurred prior to in-
statlation of PSt's njore sophisticated equipment
Photo £ Second-generation print of same object as Photo D moving off to left during
8-second exposure. Note strange burst-like effect not apparent to observers. Approx-
imately 9:09 pm, Tri-X film with 300 mm f/4 lens. Typical of those taken by the PS I staff
during the December 10, 1975, event the photos are encouraging but not considered
definitive concerning the nature of UFOs.
outer space, vehicles from
some distant star system
which operate through
space/time in a manner we
cannot yet comprehend. It
IS this hardware aspect of
UFOs which renders them
susceptible to instrumen-
tal investigation. We may
be on the way to answering
what UFOs are, but the
questions of where they
are from and why they are
here will ultimately have
to be answered as well.
Where, then, does all
this leave us, as interested
citizens who want to know
41
the truth? And what can
we do to help, or to be
prepared when the next
"flap" or wave of activity
once more fills our skfes
With something strange?
There are things we can
all do. For those fortunate
enough to live in the vicini-
ty of Austin, training and
participation in PSI ac-
tivities as a volunteer might
be possible. The expense of
supporting a research ef-
fort such as this suggests a
way in which we might con-
tribute. As radio amateurs,
however, we have unique
qualifications for par-
ticipating in UFO event-
sharing on a national as
well as a local level.
We can keep informed
through groups which cor-
relate and communicate
information, such as the
Center for UFO Studies.
Dr. |. Allen Hynek, Chair-
man of CUFOS, was
technical advisor for the
production of "Close En-
counters." Much of the
realism of this film can be
attributed to the case in-
formation he was able to
provide. We can also join
or support investigatory
groups such as MUFON
or GSW, for example,
MUFON amateur radio
nets meet weekly. On
Saturday mornings at 1 200
UTC, the 40 meter section
meets on 7237 kHz, and the
75 meter section meets at
1300 on 3975.
Every section of the
country has investigators
trained by some organiza-
tion to investigate UFO in-
cidents. They are often in-
terviewed by the media.
Most of them would be
more than happy to speak
at a radio club meeting, or
to know that local hams
are ready to help during a
local UFO flap. Many of
them need education in
the tremendous capabil-
ities amateur radio has for
tracking and reporting
sightings and landings.
Repeater groups in par-
ticular may be interested
in learning who to call and
what to do if UFOs appear
in their area. So the rela-
tionship can be one of
mutual benefit. Getting
qualified investigators to
the site of a UFO incident,
while it is still in progress if
at all possible, is the key to
solving the mystery. The
government agencies can
offer no help, since they
have officially declined to
investigate UFOs. The
police, if they do anything
at all, generally report the
incident to the Center for
UFO Studies via their
hotline. Ultimately, news
of the incident may filter
down from there to the
headquarters of one of the
investigatory groups such
as MUFON. A local in-
vestigator is finally in-
formed and hopefully
reaches the scene. By then,
the UFO and most of the
evidence is long gone.
Wouldn't it be much more
efficient if hams knew who
to contact in their own
area to report an en-
counter? And a call on the
2 meter repeaters in any
city ought to furnish
plenty of tracking ob-
servers or witnesses in a
hurry, We can't all have a
Project Starlight Interna-
tional in our backyard, but
we do have an HT, a
mobile, or a low-band rig
and know how to com-
municate, We also have
some technical training
which helps in describing a
UFO and its effects. Work-
ing together, we can solve
the UFO problem.
Current UFO activity has
recently shifted from
South America to Aus-
tralia, The lull in sightings
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1^ Reader Servics^sint page 323.
43
The
Schizophrenic Triangle
a split-personality radiator
Freddy Brown WA4JTJ
RED h Box 267
ScoUsvUk KY 42164
If you're interested rn a
multiband, inexpensive,
easily built wire antenna
system with DX capabil-
itieSi then here it is. It's in-
expensive because it is
made of available ma-
terials, such as wire and
small variable capacitors
for the matching section.
This also contributes to the
ease of construction. Be-
cause the antenna has a
dual personality, or is bi-
banded, 1 call it ''schizo-
phrenic."
The triangle antenna is a
single loop of wire fed by a
gamma match. In fact, the
loop has two gamma
matches (one for each
band of operation). 1 first
SIDE OF
•- 2i
INSULATOR
IF WOOD 11
US£D
fikfk
WIHE
1 L
built a 40m triangle as
described by Byron Self
WB6UFW.1 I operated this
antenna for about a year
with excellent results. A
loop is very wide-banded.
In fact, by use of the gam-
ma match, the swr of this
antenna never exceeded
1.3:1 at the band edges.
The 40 meter foop is 1
wavelength long (140 ft.).
After realizing this closed
antenna loop would prob-
ably resonate with 15
u eotTs
to HOLD
CIM TCtWER
in Itlm.
wroao
APEX
IMSULATIWt
TWIST wme
TV
TWIST
l*flftt
canNCAs
f^fr 1.
¥lg, 2.
44
r
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• Inpjts for 2 rigs * Speaker and phone jacks
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These MFJ active filters are the most copied in Industry.
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If s easier
Dx'er
Contester • Trafficman
Ragchewer
Telex headphones and headsets
make it easier to enjoy the hobby.
Whether you prefer lightweight or
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1*^ H&sder Service— see psge 323,
45
H05£
CLAMPS
— TV STAMdCJFf^
CENTER OF aOTTOW WIRE
WIRE
AtiTEHNA
WlflC
meter {21 mHz) excitation,
I proceeded to build a 15m
gamma match and at-
tach it directly to the
antenna. The same results
were obtained on 15
meters — low swr and very
Wide bandwidth Adding
the second gamma match
didn't alter the perfor-
mance of the original
antenna.
Shortly afterwards, t
constructed a triangle loop
for 80 and 10 meter opera-
tion. I simply computed
the loop length for the mid-
dle of the low frequency
band by using the formula:
1000/f{MHz), For example,
1000/3.6 = 278 ft. This is 1
wavelength for 80 meters
and 8 wavelengths for 10
meters.
Construction Notes
I'm including diagrams
from Byron's article to aid
in the construction of the
wire loop and gamma
matches These are Figs.
2-4. Fig. 1 shows the
''schizophrenic" triangle
with gamma matches at-
tached. Solder the braid of
the two 50- or 75-Ohm
coaxial lines to the center
of the loop. Solder the
center conductor of the
coax to one side of the
capacitor and the gamma
wire to the other side of the
capacitor. 1 used a plastic
freezer box to house the
capacitor and applied
silicone rubber sealant to
waterproof the holes made
L' Bfl*Clc£TS
If]
I IM in. ^OVE BOlTS
F/fr 3-
by the exiting wires. I used
a standard close-spaced
365 pF broadcast band
capacitor, which has not
arced yet with my 180 W
transmitter.
Final Notes
I installed both loops on
my SO-foot tower (Fig. 5L
leaving room at the top for
TV, 2 meters, and maybe a
yagi or two later on. The
loops should be kept as
close to equilateral tri-
angles as possible. Of
course, 1 couldn't do this
with the 80 meter loop on
my 60-foot tower. There-
fore, 1 stretched the
horizontal side to 122 ft.,
and each slanting leg was
78 ft long. This put the
horizontal leg about 10 ft
above ground and the apex
at the top of my tower. The
whole loop is tilted a few
degrees off vertical. I
would expect that tilting
the triangle would result in
a lower angle of radiation.
t
' 1
S
4.
.^ rt
DATA. IN TASLC 1
GAMMA
l&IVEH LENGTH
itf SAI?DCN HDS£ OR
OTHEB HCMT «EIGHT
\
SOLDER
wO
iMTc*<i«f6 «inc
Fig. 4,
One last point. A good
antenna switch in the
shack is desirable for quick
band changes.!
Reference
1 Self. **The 40'Meter Trian-
gle," QST. Vol. LX. No. 5, May.
1976.
FRONT VtCW
K HE K)<NTS
Fig. 5.
Loop mformatlon
Loop length for
Bafid middle of band
80 277*9"
40 141'
20 70'5"
15 472"
to 35 8'
6 1911"
CombinatloftB Loop Length
40m and 15m 141'
80m and 10m 277'9"
Gamma data
0 S
96" e"
73' 4"
35" 2"
27" 1 .5"
18" t**
Gamma data
same as atK>ve
same as above
Table T*
Capacitor (pF)
300
200
100
75
50
30
Resonant frequencies
40m— 7.100 MHz
15m— 21.277 MHz
80m— 3.6 MHz
10m— 2a830 MHz
46
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l^C95
p^ Read&f Service—sm^ page 323.
47
Terry Conboy N6R Y
1231 Cresiview Drive
Satt Cartas CA 9407Q
From CW to Computers
a digital modulation primer
You're sitting in your
easy chair discussing
the fine points of raising
begonias with the bunch
on 3914 when something
sounding a great deal like
the soundtrack from the
"Texas Chainsaw Massa-
cre" begins to put a decid-
ed cramp in your rag chew-
ing style. The group is
divided on whether it is
SSTV. Teletype^^, fac-
simife, or just the Russians
at it again. Whatever it is,
you decide, it is at least 50
kHz wide, and bound to be
part of the computer con-
spiracy incited by 73 and
its I/O section. Bunch of
whippersnappers and their
confounded digital mod-
ulation!
Digital modulation is
nothing new, having been
started by Samuel F. B.
Morse and others quite
some time ago Lately,
however, it has grown into
something quite removed
from the days of manually
sent Morse code and of
clanking, noisy, mechan-
ical teleprinters. In-
tegrated circuits have
made complicated signal
processing simple, or at
least small, and computers
are now available at a
price within reasonable
reach. Lots of hams like
you have found that there
is a great amount of fun in
programming and playing
with microcomputers.
After the initial hardware
debugging and the game
playing which follows, you
WAVCTER 1*2
/
JJENERATOfft
ANALYZER
AM 11^ ^ur
BfPASS
MAvrrSK 142
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6£lCMAT0ft
SPECTRLM
AHMLrZEft
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H-P 2SIA
SOU ARE «AVE
GENEHftTCW
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WAVETEK 142
FLfNGTION
G£N£f^ATOfT
VtS INPUT
f
BOONTDN aOZE
FU-AU SIGML
CCNERATOA
H-P 95358
SPECTHUW
AfiALTZE'^
PM pPUT
Fig* 1(^1 A1 measurement setup. Carrier set to 7 MHz. (bl
F1 measurement setup. Carrier set to 20 MHz. fcj. F2
measurement setup. Carrier set to 55 MHz.
remember your tempo-
rarily-forgotten trans-
ceiver and begin to wonder
how you can hook your
new toy to your old one.
And while you're wonder-
ing that, you also wonder
what the output of your
transmitter will be and how
many ''Sunday Afternoon
Begonia Appreciation
Nets" wilt be doomed by
your next computerHdriven
transmission
The FCC stands in the
way of complete havoc,
leaving you only a few
loopholes Presently, they
only allow two types of
digital modulation for
general use. One is good
old Morse code, and the
other is the Baudot
teleprinter code* The
Baudot code is a five-bit
code with definite legal
speed restrictions; Interna-
tional Morse is not limited
in speed at alL Receipt of
Morse by ear is limited to
perhaps 100 or so, and
there is a group of
operators who specialize
m running speeds like that
for their own fun and
amusement. But your com-
puter is much better
equipped to send and
receive Morse than the
human brain, and with a
small amount of restraint
on your part, you should be
able to run Morse much
faster than 100 wpm and
still not convince the FCC
that it should pass new,
even more restrictive laws
to slow you down once
again. To help you gain an
appreciation for the band-
widths of the signal you
may create when you
digitally modulate your
transmitter, I have made a
few measurements to in-
dicate what you might ex-
pect, both for speeds and
codes now permitted, and
some that might be al-
lowed on the air.
Types of Digital
Modulation
The most familiar type
of digital modulation is
probably CW. This is called
continuous wave, because
it normally isn't, to help
the confusion, tt is better
to call it A1, which means
on-off amplitude keying. In
case you haven't checked
lately, it is still being used
in the amateur bands,
A modification of CW is
A2. This is tone-modulated
AM. Usually this is used for
code practice to allow the
use of simple receivers. Its
chief identifying character-
istic is its inefficiency. It
uses lots of transmitter
power without paying you
back in signal*to-noise
4d
Fig. 2. CW signal at 300 bps with steady dots. Scale: 1 kHz Fig. 3. CW signal at 300 bps with steady dashes. Scale: 1
per divison. kHz per division-
ratio. Let's let this one die a
natural death.
Lots of hams are now ac-
tive on TeletypeTM^ using
FSK- This is designated F1,
which stands for telegra-
phy by frequency shift key-
ing. The key-down or mark-
ing condition is noted by
one frequency, and the
key-up or spacing condi-
tion is noted by another.
Normal practice on the HF
bands is to use a shift, or
frequency difference, of
170 Hz, This has largely
replaced the use of 850-Hz
shift by hams.
As in the case of CW,
FSK has a counterpart
called AFSK-FM, which is
tone-modulated FM,
designated F2. Audio tones
are shifted by the
teleprinter keyboard (or
computer) output, and
these tones then are used
to modulate a standard FM
transmitter. This is in
widespread use on many
FM repeaters designed
specifically for the enjoy-
ment of RTTY enthusiasts.
Since the FCC groups
ihase modulation with fre-
quency modulation, you
Afould probably not be
itretching things too much
:o suppose that you could
jse PSK, or phase-shift key-
ng, and call it F1. I have
lever seen any amateur
jse of PSK, probably
>ecause of the difficulties
in demodulating it. It may
not be totally suitable for
use where the propagation
medium is unstable, caus*
ing multiple paths between
two locations and the ac-
companying fading and
rapid phase rotation.
For these reasons, I will
limit myself to looking at
only three types of signals:
CW, FSK, andAFSK-FM. I'll
show you what present
signals probably look like,
and give you a few glimps-
es into what the future
may allow on the amateur
bands to enhance your
digital modulation plea-
sure.
Before we begin, one
idea is very important.
That is a concept called
frequency scaling. What
this means is that the spec-
tra of digital signals will be
unchanged, except for fre-
quency scale, if you
change both the rate of
modulation and the fre-
quency shift, if any, in the
same porportion. For ex-
ample, the spectrum of a
transmitter with FSK of
170-Hz shift and 45.45 bit
per second modulation will
look identical to that from
a transmitter with 17-kHz
shift and 4545 bit per sec-
ond modulation, except
that the spectrum will be
blown up in the frequency
scale by 100 times. This
trick was used in all of the
examples that follow, to
allow the spectrum
analyzer to be swept over
wider frequency ranges at
higher sweep speeds, using
wider detector bandwidths
than would have been
possible. In other words, I
used sleight-of-hand to
produce the spectrum
photographs. The scaling
factor used was 100, ex-
cept for the F2 spectra
(scaled by 10 times).
Morse Code
International Morse
consists of dots, dashes,
and three different lengths
of spaces. Dashes are (sup-
posed to be) exactly three
times as long as a dot, as is
the space between letters.
The space between dots
and dashes is the same
length as a dot, and space
between words is seven
times this length. Each dot
period represents one
binary digit or bit of infor-
mation.
In order to produce the
spectrum for a CW signal,
we need to know the rela-
tionship between the
speed in words per minute
and the signaling rate in
bits per second (sometimes
called a baud}. The FCC
uses a standard word com-
posed of 50 bits.* There-
fore, one word per minute
corresponds to 50 bits per
minute or 0.8333 bps.
Fig. 4, 600-Hz shift FSK Morse at 300 bps with steady
dots. Scale: T kHz per division.
49
f4g. 5, 600-Hz shift FSK Morse at 300 bps with ran- Fig. 6, IJO-Hz shift FSK at 45.45 bps with alternating
dom keying. Scale: 1 kHz per division. Is and Os. Scale: 200 Hz per division.
Somewhat arbitrarily, I
have chosen a signaling
speed of 300 bps, which
translates to 360 wpm- This
seems pretty fast but we'll
see that the transmitted
bandwidth is within reason.
And because of the scaling
property, you can get a
good idea what bandwidth
will be produced by slower
speeds,
The FCC rules contain an
assortment of formulas for
calculating necessary
bandwidths.^ This is an in-
dication of the width of the
signal that must be
transmitted and received
in order to obtain a
reasonable replica of the
desired signal. For Al,
BW=B X K, where B is the
signaling rate in bps and K
is an empirical constant set
equal to 5 for fading cir-
cuits [aren't they all?).
From this we get a
necessary bandwidth of
1 500 Hz. This rs admittedly
an approximation, but at
least it gives us an indica-
tion that we won't need to
cover up more than one
"Begonia Net" if we in-
advertently fire up our rig
on the wrong frequency.
Fig. 1(a) shows the
measurement setup used
to generate the A1 spectra.
The function generator
produces square waves
which are used to AM the
high frequency signal
MMMi
Fig. 7. 170-Hz shift FSK at 45 A5 bps with random bits.
Scale: 200 Hz per division.
generator. The spectrum
analyzer looks directly at
the output of the signal
generator at around 7MHz.
For dashes, the function
generator is set to produce
rectangular waves with a
3:1 duty cycle at half the
frequency used for dots.
Fig. 2 shows the resulting
spectrum for steady dots
and Fig. 3, for steady
dashes. All the spectrum
photographs are taken
with the top line of the
graticule indicating the
level of the unmodulated
carrier. Vertical calibration
is 10 dB per division for all
of the spectra. These two
pictures have a frequency
scale of 1 kHz per divison.
Fig. 2 has a series of fine
lines at multiples of the
keying rate (150 Hz - 300
bps for dots). Note that
every other line is at a
much lower level than the
preceding line. This is a
characteristic of the spec-
trum of square waves. All
of the even-order har*
monies of a square wave
are theoretically zero.
Because of slight imperfec-
tions in the symmetry of
modulation, the even-
order harmonics do ap-
pear, but still at a reduced
level. It is worth noting that
the shape of both side*
bands is nearly identical,
and is in fact the same
shape as the spectrum of
the modulating waveform.
This is true only for
amplitude-modulated
signals, and definitely not
for frequency-modulated
ones.
In order to make a com-
parison of bandwidths, we
have to choose some
definition of bandwidth.
The FCC specifies allowed
occupied bandwidths for
all commercial services.
This is defined as the fre-
quency bandwidth which
leaves only 0,5% of the
average power above and
0.5% below its frequency
limits. This is easy to
calculate by adding up the
power in the carrier and
each sideband, until 99%
of the total power is ex-
ceeded.^ For signals that
do not have identifiable
discrete sidebands, a good
approximation of the oc-
cupied bandwidth is to
take the bandwidth at the
-27-dB (0 2% of carrier
power) points of the spec-
trum. This allows a quick
estimate of the transmitted
signal bandwidth, without
the mess of numerically
adding up all of the areas
under the spectral curve.
For Fig. 2, the occupied
bandwidth is 1500 Hz,
which is the same num-
ber calculated for the
necessary bandwidth. To
simplify comparison of the
bandwidths of the dif-
50
Fig. 8. 170-Hz shift FSK at 74.2 bps with afternBting Fig. 9, 170-Hz shift FSK at 742 bps with random bits.
Is and Os. Scale: 200 Hz per division. Scale: 200 Hz per division.
ferent spectra. Table 1
shows the calculated and
measured bandwidths for
all of the measured emis-
sions.
Fig, 3 has twice as many
lines as Fig. 2 since the
sending rate for dashes is
exactly half that for dots.
Every fourth line of dash
spectrum is attenuated
sharply. This is due to the
3:1 duty cycle, and can be
proved mathematically if
desired, {As they say in the
textbooks, "It can be easily
shown that. . /')
Frequency Shift Morse
To some, the thought of
Morse code sent by other
than on-off keying is a bit
strange. If you have ever
listened to the Morse iderv
tifications required by the
FCC for RTTY stations, you
can see that it is sometimes
difficult to copy code
when sent with FSK.
The human ear is well
equipped to take care of
the problems inherent in
receiving Al, but a
machine is not. The biggest
problem for the machine is
what to do while the key is
up. The noise present dur*
ing this period ts a source
of confusion to most
demodulators. Many de-
tectors use a phase-locked
receiving technique, so the
momentary absence of
signal means a loss of lock
and the need to reacquire
lock at the beginning of the
next dot or dash.
FSK has a signal present
at all times during the
transmission. This allows
the demodulator to
operate without interrup-
tion. The problem is now
shifted to the transmitter,
which has to produce out-
put on a 100% duty cycle.
However, for a given key-
down transmitter power,
an FSK system with proper
shift will provide a 3-dB ad-
vantage over the on-off
keyed system. If you are
really worried about the
power, you can drop the
output of the transmitter
to one-half of what you
were running on CW and
still be in good shape for
transmission errors.
Since we're setting up
things from scratch, we are
free to pick the shift at ran-
dom, with the only require-
ment being that we stay
within the 900 Hz max-
imum specified by the FCC.
Since the data rate is 300
bps, let's pick 600 Hz for
the shift. This would allow
us to use audio tones of
1200 Hz and 1800 Hz.
These tones are centered
nicely in the audio pass-
band of a norma! SSB
transmitter and have the
added advantage that they
are all multiples of 300 Hz,
which would make it easy
to generate the tones with
a digital frequency divider
synchronized with the
oscillator used to make the
code.
The formula for the
necessary bandwidth for
F1 is given by the FCC as:
BW ^ 2.6D + 0.55B, where
D is the peak deviation
(one-half the shift) and B is
the signaling rate in bps.
For the case at hand, BW
= 945 Hz.
The measurement setup
for FSK signals is shown in
Fig. 1(b). The function
generator output is con-
nected to the FM input of
the signal generator, either
directly or via the ran-
domizer. The randomizer is
a 25-5tage shift register
with feedback taps
arranged in such a way as
to generate a pseudo-
random sequence that is
2^^-^ long (33,554,431
bits) before the pattern
repeats. The randomizer
makes the modulation
more realistic, since send-
fng continuous dots
doesn't convey much infor-
mation. Steady dots tend
to create the worst case for
transmitted bandwidth,
too.
Fig. 4 shows the spec-
trum with Morse dots at
300 bps with 600-Hz shift.
The frequency scale is the
same as in the previous
photos. Except for the
Fig, 10, 170-Hz shift FSK at 110 bps with alternating
Is and Os. Scale: 200 Hz per division.
51
Fig. n. 170-Hz shift FSK at 110 bps with random bits.
Scale: 200 Hz per division.
fcemiency of the spectral
lines to bunch up rn the
region of the resting mark
and space frequencies,
there are many similarities
between the AT and F1
spectra. The occupied
bandwidth is again 1500
Hz, which is almost 60%
larger than the necessary
bandwidth for F1. At fre-
quencies well away from
the carrier, the sideband
levels of the two spectra
are nearly identical.
Fig. 5 shows the effect of
the randomizer. The
discrete spectral lines are
gone, and are replaced
with noise-like spectral
lobes. It is interesting that
the spacing of the lobes is
the same as the major lines
in the spectrum of dot
modulation. The band-
width is nearly the same as
with dots, but the level of
the sidebands several
kilohertz away is some-
what lower, due to the in-
crease in low-frequency
components in the bit
stream at the expense of
the high-frequency com-
ponents, which is caused
by the randomizing pro-
cess.
FSK and Teleprinter Codes
The most common use
of Fl is in sending text
messages between me-
chanical teleprinters. The
FCC has specified that the
Fig. 12. 1200-Hz shift FSK at 300 bps with alternating
Is and Os. Scats: 1 kHz per division.
Fig. 13. 1200 Hz shift FSK at 300 bps with random
bits. Scale: 1 kHz per division.
code to be in general use
by amateurs is the 5-bit
Baudot code, named after
Emile Baudot, the man
who pioneered the concept
of printing telegraphy. As
used by amateurs, it is a
start-stop or asynchronous
code, since it does not re-
quire an external syn-
chronizing clock. The
equipment is synchronized
on a character-by-char-
acter basis by using a
start bit, which is always a
space, and a stop pulse,
which is always a mark, to
frame the character. The
start bit is the same length
as each of the five informa-
tion bits. The stop pulse in
Baudot is normally a
minimum of 1.42 times as
long as the other bits. It
can be as long as desired,
since the resting condition
between characters is the
marking state. For com-
puter use, the stop pulse is
often made two times as
long as the others, for con-
venience in timing,
A second code author-
ized by the FCC for limited
use (presently on OSCAR)
is called ASCII. That stands
for the American Standard
Code for Information Inter-
change. It is similar in con-
cept to the Baudot code,
but consists of a start bit,
seven information bits, a
parity bit [for error check-
ing), and one or two stop
bits. Normally, two stop
bits are used when the
signaling rate is less than
300 bps, and one is used
when the rate is greater
than 300 bps. Because it
has seven information bits
instead of five as in
Baudot, ASCII has a
greater number of possible
code combinations. Many
of these are used in making
upper and lower case
alphabetic characters, but
there are also a number of
control codes not found in
Baudot at all. Because of
its greater versatility,
ASCII is preferred for com-
munications with com-
puters.
Another possible code
that might be used for
computer communications
is straight binary numbers.
Transmitting a start bit,
eight information bits, and
a stop bit would allow
sending binary numbers
equivalent to decimal
numbers from zero to 255.
Although meaningless to
(normal) humans, the com-
puter uses these numbers
for machine language pro-
grams and data. Alas, the
FCC does not at present
permit the use of this type
of data, since it is neither
Baudot nor ASCII.
You may be curious
about the number of words
per minute that are
produced by a given bit
52
rate using Baudot and
ASCII. If we assume that a
word consists of five
characters and a space be-
tween words, the speed in
wpm for Baudot is 1.3S
times the signaling rate.
For ASCII with two stop
bits, it is 0.91 times the bit
rate, and for ASCfl with
one stop bit, it is equal to
the bit rate. Compare this
to 1.2 times the bit rate for
Morse. It's interesting to
note that Baudot is the
most efficient of the codes
mentioned, in terms of
words per bit
Standard amateur prac-
tice at present is to use 1 70-
Hz shift on FSK. (The origin
of this number is probably
as obscure as that for the
1.42-unit stop pulse!) This
has almost completely
replaced the use of 850-Hz
shift because of improved
resistance to interference
and selective fading when
using 170-Hz shift. Another
shift which may be of
future interest is 1200-Hz
shift. This exceeds present
FCC limits, but is in wide
use for medium speed
telephone data sets and for
cassette tape storage of
computer programs by
hobbyists using the "Kan-
sas City standard/' The KC
standard normally is used
at 300 bps and has been
successfully used by com-
puter amateurs for pro-
gram exchange via long
distance telephone as weJI
as by magnetic tape. It is
quite possible that it might
be usable for rf transmis-
sion as well.
The speeds used for the
measurements were 45.45
bps (60 wpm Baudot), 74.2
bps (100 wpm Baudot), 110
bps [100 wpm ASCII), and
300 bps (KC standard).
Calculated and measured
bandwidths are given in
Table 1 The measured
spectra are shown in Figs. 6
through 13. The first of
each pair of photos
represents steady alter-
nating Is and Os, and the
second photo shows the
effect of a pseudo-random
bit pattern. The photos for
the narrow shift signals are
made with 200 Hz per divi-
sion on the frequency scale
to allow adequate resolu-
tion. The 1200-Hz shift
spectra are again at 1 kH^:
per division.
Notice that, generally,
the spectra do not have
any lines at what would be
the resting mark or space
frequencies This will only
be the case where the
signaling rate and the shift
are integer multiples (e.g.,
300:1200 or 300:600). The
point of this is that you
may not be justified in say-
ing that an FSK signal looks
just like two oscillators
that are being alternately
switched off and on. That
should make the purists
scratch their heads a bit.
AFSK On FM
Lastly, we will look at
the spectrum that you
might see coming forth
from the antenna connec-
tor on your two meter rtg
when you are putting FSK
tones into the microphone
jack. The measurement
setup is shown in Fig, 1(c).
Only two cases are con-
sidered: 170-Hz shift at
45.45 bps using tones of
2125 Hz and 2295 Hz, and
750-Hz shift at 45.45 bps
using tones of 2125 Hz and
2975 Hz. Peak deviation of
the rf carrier was set to 5
kHz peak in both cases.
The use of 850-Hz shift is
still common on VHF,
probably because of MARS
influences. On VHF, there
is probably no significant
difference between the
two shifts in terms of per-
formance, since signal-to-
noise ratios are normally
very good, and errors in
transmission are rare.
There really isn't much
difference in the band-
widths, either, as Table 1
shows The use of 850 shift
tones carries with it the
disadvantage that the
amplitudes of the side-
bands at some distance
Fig. 14- 170-Hz sh/ft AFSK-FM at 45 A5 bps with alter-
nating Is and Os, Peak FM deviation is 5 kHz. Scale: 5
kHz per division.
from the carrier do not
diminish as quickly as
those for the 170 shift
tones.
Bandwidth Reduction
The measured spectra
are laboratory creations,
but they should reflect
with some accuracy how
actual transmitted signals
will appear. It is likely that
real signals may be slightly
narrower in bandwidth
than those shown. Normal
CW transmitters employ
some filtering in the keying
circuits to reduce the
tendency to generate ''key
clicks/' These clicks are
just the low level
sidebands seen in the
photos at some distance
from the carrier. The filter-
ing in the transmitter
makes the spectrum of the
keying waveform fall off
much more rapidly and
reduces interference with
nearby stations.
Amateurs who generate
FSK signals by putting
audio tones into SSB
transmitters may restrict
the transmitted bandwidth,
also. The SSB filter in the if
circuit will sharply at-
tenuate signals which
might otherwise extend
beyond the edges of the
Fig. 15. 850-Hz shift AFSK-FM at 45A5 bps with alter-
nating Is and Os. Peak FM deviation is 5 kHz. Scale: 5
kHz per division.
53
filter. This is especially
true in the case of FSK
Morse or future use of Kan-
sas City standard signals,
since their bandwidths ap*
proach that of the SSB
filter. Intentional filtering
may be added at audio f re-
quencies between the
A FSK generator and the
transmitter input to ac*
complish the same result.
Filters which reduce the
bandwidth of FSK signals
[or any FM signal} tend to
introduce an AM compo-
nent to the signal If the
filtered signal then passes
through a transmitter cir-
cuit that acts to partially
limit the signal such as an
overdriven output stage,
the AM component may be
removed and the band-
width widened once again.
What this means is that if
filters are added to inten-
tionally reduce the trans-
mitted bandwidth, they
will not be completely ef-
fective unless they follow
non-linear circuits.
m *
Someday,
The FCC may give us a
chance to use all of these
emissions to improve com-
puter communications,
and communications in
general as well Although
a phone transmitter may
seem simple by com-
parison, when the signal-to-
noise ratio is poor, digital
systems give superior per-
formance. Mother Bell has
already made the decision
to convert the vast
majority of her switching
Nee.
Occ.
-27 dB
Fig-
Bps
Shift, Hz
BW, Hz
BW, Hz
BW. Hz
2
300
0
1500
1500
900
3
300
0
1500
750
900
4
300
600
945
1500
1500
5
300
600
945
—
1400
6
45.45
170
246
318
318
7
45.45
170
246
—
315
8
74.2
170
262
371
371
9
74.2
170
262
—
380
10
110
170
282
330
440
11
110
170
282
—
360
12
300
120O
1725
2100
2100
13
300
1200
1725
-
2200
14
45.45
170
14590
13770
17000
15
45.45
850
15590
17000
17850
Table 1. Bandwidth summary.
systems to pulse code
modulation to take advan-
tage of the ease of routing
long-distance conversa-
tions with logic ICs instead
of relays. PCM requires a
rather large bandwidth, but
makes sense in the upper
UHF region through the op-
tical wavelengths.
The ''Begonia Net" may
not soon be running PCM
in place of lower sideband,
but a "Worked All 8080s
Award'' for computer-
equipped hams running
CW at 360 wpm may not be
far off.H
References
1. Lizee, Ga&pard/"Speed Stan*
dards for International Morse
Code;^ Ham Radio, April, 1973,
p. 68.
2. FCC Rules and Regulations,
Volume 2, Subpart C, Section
2.202.
3. GuenUler, Ron, "RTTY Signal
Bandwidth/' RTTY Journal,
April, 1977, p. 5,
4. ITT Reference Data for Radio
Engineers^ p* 23-8, Indianapo-
lis, Howard W. Sams, 1975.
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shall give thee the desires of thine heart. Commit thy way unto the Lord; trust
also in Hinst sfKi He shall briny it to pass", (KJV)
Jesus telis us in the Gospel oF John that He is the way, the truth and the life*
If we believe this, follow His teachings and obey His coinmands, we may ask any
request of Him and it will be granted. He has told us this so we will be filled
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His way for our life will fulfill our desires and solve the complex and confusing
problems of this life. Jesus said, *'l am come that they might have life# and that
they might have it more abundantly"* John 10:10b (KJV)
God*s plan for our life makes us a complete person through Jesus Christ, Please
accept His love and have a blessed Christ -centered holiday season.
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64
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56
A 28C Touchtone
TM
Mod
something for [almost] nothing
David J, Brown W9CGI
RR 5, Box S9
Nobiesviiie IN 46060
Repeater owners, re-
mote control users.
and touchtoneTM fai^s in
general— take note! This
article will show you how
to get 24 decoded func-
tions (on IS-key TT pad
systems with A, B, C, D) or
19 decoded functions (on
1 2-kev TT pad systems with
10 numbers, the *, and the
# only) from your present
16- or 12-function systems
— and very inexpensively.
Depending on how you
decode your TT tones at
the receiving end, this
modification will cost you
from 28? to 76? at January,
1978, prices on TTL logic
(source is Poly Paks*)
Since nearly all the up and
working systems use 567
tone decoders that output
56
a low for a decoded number
(as do many other systems),
and these lows are inverted
before the low group/high
group ANDing to get a sin-
gle function, I will concen-
trate on those systems.
Mine is shown in Fig. 1. By
just comparing it to yours,
you can tell what may be
missing on yours. 1 have
duplicated my TT decoder
section for clarity. It has
nothing to do with whether
you can get the extra 7 or 8
functions, and is shown on-
ly because [ use an extra
enable/disable function
line and three input gates
on TT decoding. This is not
required, so, if your system
uses the more common
two-input gating system,
don't fret.
Since I already had all of
the ICs with letter designa-
tions, and half of IC-D
wasn't being used, I only
had to use unused func-
tions of ICs already there,
except for adding ICs 1 and
2. While we are on ICs 1
and 2, I will add that they
may be 7400s if you want
TTL-compatible outputs
for your extra added func-
tions. If you want uncom-
mitted outputs to run out-
side-world devices (small
low-voltage/current relays,
etc.), as I did, you use 7403s
with no wiring changes on
the sockets. This is nice if
you later change your
mind or want four of one
and four of the other.
To explain the system,
first let me cover normal
TT decoding. For any valid
TT tones, you will have one
decoded low group and
one decoded high group as
TTL lows on the inverter
(ICs A and B) input lines.
Depending on the func-
tion, this will be a high on
one of the LI to L4 points,
and a high on one of the HI
to H4 points. This will 2/3
enable one of the 3-input
gates in IC-E through ). The
common line you see con-
nected to all of the gates in
IC-E through J must go high
to finish the decode en-
abling. Example: If this line
is high and we receive a
low group 697 Hz tone and
a 1209 Hz high group tone,
LI and HI will be high, and
the number 1 will be de-
coded [TT).
As for how that common
line gets high, please take
the above example again.
A low on IC-A-1, causing a
high on IC-A-2 and LI, half
enables IC-1-1. Since this is
a TT tone we are receiving,
there is also a high group
tone {1 209 Hz), and, if there
is a high group tone (as
there is for any valid TT
tone), IC-C'8 is high, Invert
this through lC-B-11 to 10
to HTT for a low. That tow
is applied to IC-D-10 and
■&9f-
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LO GROUP
ENABLE (H)
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IC
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7410
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14
Fig. 1. *Note: ICs 1 and 2 can be 7400 for TTL outputs or 7403 for uncommitted collector outputs.
disables IC-D-8 (high),
through IC-A'1 3 to 1 2 (I owl
and disables all the single
low tone group decoders,
IGI. When a low group
tone is also present (as with
any valid TT tone), follow-
ing IC-C-6 (high), through
IC-A-11 to 10 (low) and LIT,
to IC-D-1 3 disables lOD^II
(high), through IC-A-13 to
12 to all of IC-2, disabling
all the high tone group
single tone decoders.
Going back to IC-C-6 and
IC-C-e (both high on TT),
these highs go to tC-D-1
and IC-D-2 to form a low at
[GD-3. The last gate in IC-
D is wired as an inverter
and causes the low at IC-
D-3 to be a high at IC-D-6.
This 1/3 enables all the TT
decoders and says a valid 2
tone TT signal is present.
Since we chose the exam-
ple of 697 Hz and 1209 Hz
(TT function 1), the low
group (697 Hz) fully decod-
ed as a high goes to 1/3 of a
gate in IC-E, and the high
group (1209 Hz) fully de-
coded as a high goes to
another 1/3 of the same
gate in IC-E. Along with the
TT enable high, this causes
the function 1 to go low
and the TT number 1 is
decoded.
If you follow the aster-
isk in Fig. 1, I have shown
also the single tone (770
Hz) decoding, All the little
L and H characters indicate
low and high, respectively,
and refer to gate or line
status for this one par-
ticular (770 Hz) example.
You will see that, with the
high group tone of any kind
missing, tC-C-8 is low, dis-
abling alt the TT decoders
via IC-D-2 (low) and IC-D-3
(high), through inverter IC-
D4 and 5 to 6 (low! The
missing high group tone
and IC-C-fi (low), through
inverter IC-B-11 to 10 (high)
and HTT, causes IC*D 10 to
be high. Since there is a low
group tone (770 Hz), lC-C-6
is high and enables the
other half of IC-D-9 and 10
to 8 and makes lC-D-8 tow.
Inverted through IC-A-13
to 12 (high), all the low sin-
gle-tone decoders are 1/2
enabled. Since the low-
group-only tone is 770 Hz,
IC-A-3 is low and IC*A'4 is
high and enables the other
half of IC-1-4. This causes a
low at IC-1-6 and a fully
decoded 770 Hz function
at IC-1-6.
I confess to a bit of foxy
maneuvering at this point.
This whole business (seeing
as all I had to add were ICs
1 and 2] was done original-
ly to detect the indepen-
dent high and low tone
group decodings and only
light LED indicators. It was
not until the unit was all
built and running that I
decided why not use these
extra functions to do things
on the receiving end with a
bit of extra circuitry to
define single tone versus
TT pair tones. It greatly
reduces the necessary
hardware to handle station
keeping such as changing
from tight to loose squelch
on the repeater receiver
and resetting the time-out
timer if someone over-talks
it That way, none of the
original 12 or 16 functions
are used up or confused,
like on an autopatch re-
peater, These can be used
as completely separate
functions.
While I am covering bits
of honesty, I should men-
tion how this whole thing
works from the sending
end. Following Fig. 2
should help. This is nothing
more than the face of a TT
pad. As long as you push
single buttons, you get
dual TT tones correspond-
ing to the key pressed. If
you push any adjacent parr
of keys on a standard TT
pad, you get only the single
tone for that row or col-
umn. Following Fig. 2, if
any pair of the column
keys such as (1-4), (4-7), or
57
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(7-*) are pushed, that col-
umri tone results. Columns
produce the high tones, go-
ing from lowest to highest
as you go left to right [i.e.,
left column = 1209 Hz
through right column (if
present A, B, C, D) = 1633
Hz]. Any row pair that is
pushed produces a low
group tone, going lowest to
highest as you go top to
bottom (i.e., top row — 697
Hz through the bottom row
= 941 Hz). A row pair ex-
ample to get 941 Hz would
be C*-0), t04L or t#-D), Any
pair example in a row or
pair in a column seems to
work, but adjacent pair
keys are easier to hit and
better insurance that you
have both keys down.
As for rules to follow
when sending, be sure to
hit and depress both keys
of a pair at the same time
and release at the same
time. If you hit one key and
then add another, you will
get a TT tone and single
tone sequence not desired
in this decoder. Changing
the decoding further, you
could put this to advan-
tage in two-number sys-
tems. The Indianapolis
16/76 machine has a very
interesting and helpful
system function that is TT-
tone controlled. By push-
ing the series 71 through
79 Cexcluding 77) TT
numbers, a tape is played
back to you giving you one
track of 8 possible tracks
worth of prerecorded
messages. As you might
guess, the number 7 fol-
lowed by 6 (76) gives you
all the information about
the 16/76 machine opera-
tions and format. Adding
more housekeeping func-
tions could be done by
adding another full two-
number set decoder group
(quite a few ICs) and using
the 10s or 80s, etc.,
numbers just as the 70s are
now used for the tapes.
Just as easily, and for much
less expense, at least 7
more functions could be
added by my method with
no changes made out in the
field by the sending sta-
tions-
The sequence 7-6 would
still be a decoded 7-6 and
activate the tape that ex-
plains 16/76. Using the 7-4
for a single tone example,
since they are a column
pair, and 7-6 is neither a
column nor a row pair, if
7-4 is pushed in sequence
form, the 74 tape would
still play. If the 7-4 were
pushed together, however,
a single tone of 1209 Hz
(left column) would result,
causing a low decoded at
HT*1 in Fig, 1 , This could be
used for whatever you like.
Since t have used our
16/76 machine which Indy
amateurs are quite proud
of for an example, please
allow me to issue an invita-
tion and a couple of words
of warning/advice/help.
Should you pass through
our town (or within about a
25-mile range), and want to
dial up the tapes, you must
observe two simple roles.
The first is: The dial-up on-
ly works if preceded im-
mediately (without drop-
ping carrier between} by
audio. A valid and ap-
preciated by us (and the
FCC) way of doing this is:
Using my call only as an ex-
ample—"This is W9CG1
accessing tapes/' Send first
TT (7) for about 1 second,
then send second TT (any
but 0 or 7) for about 1 sec-
ond, then drop carrier. To
allow for any of the
emergency-type break-ins
that might occur, the tape
was done so it can be
"talked over/' i.e., if
another station has emer-
gency traffic, and a tape is
playing, he has only to key
the mike and start talking,
and the audio on the tape
is dropped below him by
several dB. The next rule is:
Please allow 45 seconds
minimum between the end
of the last tape message
sent and the next request
to allow for rewinding of
the 8~track player system.
Thank you.
Into every life a little
rain might, if not will, now
and then fall. I confess, 1
do not know what happens
when the newer so-called
(but not) TT pads are used
that are little keyboards
and IC generators (Heath
MicoderT'^ and keyboard
and Motorola TT*type tone
IC, etc.). Pushing two keys
at once in these systems
produces results I can't be-
gin to predict, having never
owned or even operated
one. You can only try it and
see. I am reasonably sure
that the manufacturer
would not be so careless as
to allow a catastrophic
failure to occur on a two-
key press, since it is so easy
to do it accidentally; but
you may get one or the
other of the dual TT tones,
or not any tone at all — in-
stead of the single tone
desired. Systems consider-
ing my add-on decoders
should poll their members
using it for the number of
"non-reaT' TT pads or the
results of two key press ac-
tions on the "non-rear' TT
pads, or keep these as sta-
tion housekeeping control
tones for use by control
stations having real TT
pads.
For the mtniscule cash
Outlay, this system modifi-
cation has been infinitely
handy to me for use as
everything from a trouble-
shooting aid to a high/low
tone pass filter alignment
aid and a free (almost) sta-
tion control In my opinion,
it would pay to use the
7403s for both ICs 1 and 2
and connect the outputs
up to +5 volts through
limiting resistors and LEDs,
even if you are going on to
TTL inputs. This still gives a
ground or +5 volts output
usable as a TTL input and
adds the ability to monitor
what is going on in the few
parts the average system
will have to add on. You
then have a visible panel
status indicator (on when
that single tone function is
decoded).
While I can't imagine
anyone finding trouble
with this that I can help
with [i.e., I can't show you a
solder splash, short, etc.), I
remain, as always, at your
service for an SASE, The
wiring for the TT decoder
portion {7410s) is not given
on each IC-E through K but
does appear in Fig. 1 for
a single 7410 for two
reasons: This is not part of
the modification and new
system, and, if you dupli-
cate it, you can hand wire it
to suit your own board lay-
out and fill in your own
numbers on a copy of the
page from this magazine. I
muttered the first time 1
saw this in another article
using a lot of ICs but it
worked out beautifully for
me, and the copy of the
nice neat schematic from
the magazine with my
numbers neatly penned in
is now a unique diagram
for my particular board
— great for troubleshoot-
ing. I hope this works out
welt for you, also, if you
are duplicating the whole
system of Fig. 1 . B
5d
EDGECOM SYSTEM 3000A AND FMS-25
PERFORMANCE THAT CHALLENGES
YOUR
IMAGINATION
SYSTEM 3000A: 144-147.995 MHz FM transceiver that features: • Twenty
front-panel-programmable memory channels • Memory scanner • Band
scanner • Any transmitter offset • Memory channel monitoring • Two
priority channels • Extraordinary receiver • 25 Watts output • American
made • Full two-year warranty • $549.
FMS-25: Uses the same fantastic receiver and transmitter as System 3000A.
Features: • Ten front-panel-programmable memory channels • Built-in
band scanner • Full coverage in 5 kHz steps • Electronic push-button tun-
ing • Any transmitter offset • Wired forcommercially available Touchtone
microphones • American made • Full two-year warranty • Only $439.
IVIinimum $3.00 for
shipping & handling
on ALL ORDERS.
Prices FOB Medford MA.
MA residents add 5% sales
tax.
V/SA
Radio Electronics
209 Mystic Avenue
Medford MA 02155
(617)395-8280 ^jas
1^ Reader BervfCGsee j^age 323,
59
Space Age Surplus
— your own Saturn V?
Bill and Karha Endrtss
II 28 Marygon Street
Ki^immee FL 32741
With the tremendous
advances made in
electronics and the ter-
mination of the Saturn and
certain other space pro-
grams, today's surplus
"junkie" has a whole new
world to explore. Let us
take a trip to a local
surplus store and see what
kinds of goodies a com-
puter hobbyist, turned
bargain hunter, can find.
There is a super surplus
store in Orlando, Florida,
called Skycraft Parts And
Surplus. It is owned and
operated by Bob Fiedler,
and it has a wide variety of
both government and in-
dustry surplus.
In years past, a trip to
your local electronic
surplus store meant hours
spent gazing at racks of
armed forces hardware.
These units were usually
transmitters, receivers, and
transceivers. They came in
shock proof heavy-duty
cases, and the components
were sprayed with varnish
to protect them from the
elements. The units were
designed to withstand a
war. They operated from
various power sources that
usually operated at 400 Hz.
Numerous articles filled
the magazines on how to
convert this surplus to
civilian uses.
The surplus that one
finds today can be divided
into two broad categories:
tube surplus and solid state
surplus. The older tube
surplus is characterized by
vacuum tubes and general-
ly larger physical dimerv
sions. Most of this equip-
ment was used by the
military, with only a smat-
tering of industrial surplus.
Unless you have in-
terests in the ham field or
you need a particular
device for a specialized ap-
plication, my advice to you
is to stay away from tube
surplus. Even if you buy
one of these units with the
thought of stripping it for
parts, you will still come
out losing. In these units,
most of the capacitors are
quite old, the resistors
won't be precision
resistors, and the power
supply components will be
designed for the higher
voltages necessary to
operate vacuum tubes.
The newer surplus is an
outgrowth of the tremen-
dous advances made in in-
dustry and the termination
of several of our space pro-
grams. We can divide this
newer surplus into two sub-
categories: space hardware
and industrial hardware,
With the advent of the
space shuttle, two impor-
tant things have happened
that have released and will
continue to release great
quantities of space hard-
ware into the surplus
market. The first thing that
has happened is the ter-
mination of the Saturn pro-
gram. Most of the elec-
tronic hardware that was
Entrance to shop.
Core memory.
60
used in the Saturn progrann
was designed specifically
for that program and caiv
not be converted to the
space shuttle program.
The second major factor
in the release of space
hardware is in the cost ef-
fectiveness of the space
shuttle. Once the shuttle
becomes operational,
sometime in the early
1980s, all of the NASA and
most of the military
satellite launches will be
performed by the shuttle.
The reason for this is that it
will be millions of dollars
cheaper to launch the
reusable shuttle rather
than expendable boosters.
Both NASA and the
military are atready plan-
ning the shutdown of most
of their launch support
facilities at both the
eastern and western test
ranges This will assure us
of a continuing supply of
space hardware coming on
the market.
Industrial surplus is
mainly the result of the
tremendous expansion of
technology in the elec-
tronics industry in this
country over the last
decade. With the develop-
ment of integrated circuits
and large scale integration,
transistorized equipment is
becoming obsolete. This
has become even more evi-
dent in recent years as
energy costs have shot sky-
high. Transistorized equips
ment requires not only a
greater amount of operat-
ing energy than the newer
ICs, but also, if the unit is
large, it needs substantial
amounts of cooling energy
as well. With new tech-
nology becoming available
to industry every year,
more and more equipment
is becoming available to
the surplus "junkie."
The important dif-
ference between the older
tube-type surplus and the
newer transistorized sur-
plus is that the power sup-
plies for the transistorized
hardware usually operate
on 110 volt, 60 Hz power
sources. These power sup-
plies provide well-filtered
low-voltage, high-amper-
age outputs. Another big
bonus is that, in many
cases, when you plug in a
newer unit and turn it on, it
works! No tricky conver-
sions are necessary.
Let us take a look at
some ways to help you
select pieces of equipment
to stretch your surplus
dollar further. Equipment
IS sofd in four different
stages of assembly: in-
dividual components, cir-
cuit boards, partially disas-
sembled units, and intact
units. The surplus shop
pays someone to disas-
semble the intact units into
saleable portions. The
more work he puts into a
unit by taking it apart, the
more you will have to pay
for the components.
Individual Components
You can usually find any
value of capacitor or
resistor in any quality or
size among the individual
parts sold by the surplus
store. You may have to
look a little harder for the
particular transistor or IC
that you need. When buy-
ing transistors and ICs,
remember that you are
buying used or factory sec-
ond items in most cases.
This may be fine for bread-
boarding circuits or for
noncritical circuits, but do
you really want it in a
critical circuit? Most mer-
chandise in the surplus
store is sold as is, no
refunds or exchanges. In-
dividual components can
be a good buy to help you
breadboard a new circuit,
but, generally, this is the
most expensive way to pur-
chase surplus.
While checking out the
individual parts area, look
for unusual items. I recent-
ly paid $1 5.00 for a 1 2K fer-
rite core memory unit Tm
not sure just what 1 will do
with it yet, but, in the
meantime, it makes an ex-
cellent paper weight!
Circuit Boards
I have mixed emotions
about buying circuit
boards. Sometimes you
can find a real bargain, but
you can also find a lot of
iunk. Skycraft Parts has
bins of circuit boards to
choose from, priced at
three or four for $1 .00. You
can even buy a barreiful
for $10.00. The boards may
be populated with tran-
sistors, ICs, or even core
memory. The capacitors
are usually quality capaci-
tors and the resistors are, in
many cases, 5% precision
or better.
Whenever I buy a circuit
board, ! buy only those
boards that I can pick out
and examine before the
purchase is made. I usually
pick out premium boards
and therefore pay pre-
mium prices. One of my
favorite purchases was a
circuit board that I paid
$7.00 for. It had no elec-
tronic components on it at
all It was instead covered
with over one hundred
14- and 16-pin wire-wrap
sockets. This put my cost
at less than 7 cents per
socket. I also managed to
save most of the wire, add-
ing further to my savings!
When picking out circuit
boards, try to have a
definite goal in mind
before you even enter the
store. Do you need ICs, or
perhaps heat sinks? Are
you after resistors, or are
you looking for reed
relays? Once you know
what you want, you will be
in a better position to buy
the circuit boards contain-
ing the components that
you need, and not just a lot
of junk.
When I look at circuit
boards, I look at the ones
with lots of ICs. I check to
see if they are of the 7400
or TTL series of ICs and
whether or not they are in
Power supplier.
Circuit boards.
61
Power supplies and transformers.
Complete units.
sockets. I have paid as
much as $1 4.00 for just one
circuit board, but it was
covered with fully sock-
eted 7400-series ICs.
Partially Disassembled
Units
This is where I start to
get turned on. Partially
disassembled units include
such items as power sup*
plies, circuit board card
cages, diode assemblies,
switch and light panels,
and a whole host of other
goodies. If you are in the
market for switches or
lights, or other items in a
quantity, this is the best
way to go. You don't pay
the cost of someone com-
pletely disassembling the
unit as with individual
components. On the other
hand, you aren't paying for
a lot of excess baggage
either. Among the partially
disassembled units, you
can usually find power sup-
plies to fit both your power
needs and your budget.
When purchasing a
power supply, check to see
if the input and output ter-
minals are clearly marked.
You can purchase the best
power supply available on-
ly to find it is useless if you
don't know which input
and output connections to
make. All you can do then
is strip it for parts. I don't
recommend this. Any sup-
ply having the quality com-
ponents necessary for use
in computer circuits is
usually in working condi-
tion. Vou will pay a pre-
mium price for these units.
This is too expensive a way
to go just for parts.
Intact Units
This is my favorite way
to buy surplus. If you shop
wisely, you can get more
for your money here than
in any other form of
surplus buying. Not only
can you get your money's
worth out of the parts'
value, but many times you
can also find working units.
When shopping for com-
pletely assembled units, I
look for several things.
First, I check to see if it was
put together with nuts and
bolts, as opposed to rivets.
Not only do nuts and bolts
ease disassembly, but you
also end up with a goad
assortment of hardware
when you are done. Most
of the newer units use cir-
cuit boards and plug-in
modules. You usually end
up with a card cage
suitable for a home brew
project in addition to a
good assortment of parts.
If it is possible to remove a
circuit board before buy-
ing the unit, do so. While
looking at the board, check
to see what precision the
resistors are, whether the
unit uses ICs or transistors,
and the overall construc-
tion and condition of the
board. These can all be
used as indicators of the
quality and the age of the
unit.
Occasionally I will find a
unit that uses transistor
sockets for its transistors.
Check to see if the power
supply is visible. If so, look
for a heavy-duty trans-
former, large electrolytic
capacitors, and heavy-duty
power transistors mounted
on large heat sinks. Also
look to see if there is a line
cord with a conventional
plug. These are all indica-
tions of a heavy-duty
power supply that might
still be in working order
Check the front panel to
see if it contains a meter to
check the performance of
the power supply or gives a
hint of the voltages put out
by the power supply. While
at it, check for fuses. Many
times the output voltages
are protected by fuses.
These may also give you an
indication of the output
voltage and current. Above
alL when checking out a
unit for possible purchase,
check the price and ask
yourself, "If the unit is
stripped for parts, will I get
my money's worth in parts
alone?" Unless the store
owner is willing to let you
plug in the unit to see if it is
operationaL never assume
a unit is in operating condi-
tion.
Even if the unit lights up,
the only thing you should
assume is that the power
supply works. Take along
your voltage meter and
check whatever you can in
the store. I recently heard
of a local electronics firm
that sold 20 Tektronix
oscilloscopes to a surplus
dealer for $90,00 each. The
only catch was that the
CRT was burned out in
each scope and a replace-
ment CRT would cost
$1200.
I tend to prefer space
hardware over industrial
hardware. These units use
only the highest quality
components Most of the
contacts are gold-plated
and many of the soldering
posts are silver-plated for
better connections. Also,
since these units are on the
market because of a
phaseout, many of the
units are still in working
condition.
While many of the items
for sale in a surplus store
have changed over the last
few years, one thing re-
mains: You can still spend
hours browsing the shelves
of your favorite surplus
store in search of that
ultimate bargain. ■
Oddly enough, only a
few of the many surplus
houses around the country
are well enough organized
to advertise, so most of
them are unknown except
to a few local hams and ex-
perimenters, tf you have a
surplus store which hams,
computer hobbyists, or ex-
perimenters might find of
value, please send the
name, address, and phone
number to us and well
publish it Also include the
name of the proprietor.
— Wayne.
62
EDGECOM'S FMS-25 . . .
THE FANTASTIC 2M FM MOBILE RIG
Edgecom's FMS-25 2m FM transceiver is nothing short of ideal for 2n\
mobile operation. Ten front-panel-programmable memory channels provide
you with fingertip convenience for recalling your favorite frequencies, the
microcomputer-controlled PLL frequency synthesizer gives you full
coverage with any transmitter offset using push-button tuning, and the
built-in band scanner lets you automatically tune the band. Add to these
features an absolutely superior receiver, 25 Watts of output power and you
have a combination that provides unexcelled performance at the low price
of $439.
FOR THE ULTIMATE IN FLEXIBILITY,
THE INCOMPARABLE SYSTEM 3000A
The Edgecom SYSTEM 3000A 2m FM transceiver provides unequaled per-
formance, incredible flexibility and several features that go beyond the
imagination. Twenty front-panel-programmable memory channels, a
memory scanner, a band scanner, two priority channels, any transmit off-
set, electronic tuning, 25 Watts of output power and the superior Edgecom
receiver are a few of the several outstanding features that make the System
3000A the forerunner in the state-of-the-art in amateur communications.
Mg^ Well Make You Glad You're A Ham
IdI-OM electronics, rNC ^-u^
Call Collect No w to Order (314) 961-9990
2506 S. BRENTWOOD BOULEVARD
ST. LOUIS, MISSOURJ 63144
f^ Reader Service — see page 3^
63
Stirling M. Ofberg WISNN
19 Loretta Road
Wahham MA 02 1 54
An X-Band Transceiver
more 10-GHz fun
The system described in
the following para-
graphs is made up of
surplus microwave com-
ponents and other equip-
ment used in the home and
mobile station here at
WISNN. Only one piece is
described for construction
because the main com-
ponents are now available
to amateurs and made for
amateur frequencies. The
device we will construct is
not too difficult to make,
but several pieces will re-
quire the use of a lathe.
The method used to con-
trol the frequency of the
Cunn diode oscillator in
the transceiver is not
new. It is often used in
radio astronomy equip-
ment although in that
endeavor, spectral purity
of the rf output is far
superior to that achieved
here at WISNN. Many
amateurs have used the
same idea in days past
to control klystron local
oscillators for their
lEV
GLfl 4006
12 250MH2
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Fig, 1. Block diagram and simplified schematic of 10 GHz syntfiesizer.
64
receivers. Let us examine a
block diagram of my ap-
proach (Fig, 1). I hope you
will come up with better
ways to do the trick, since
we need more activity on
10,250 GHz.
It starts out with a CLB-
400B channeiizer. The GLB
drives a 1 3 Watt two meter
transmitter and receiver
and an appropriate two
meter antenna through two
coaxial relays which allow
the use of the two meter
gear for liason when set-
ting up on X-band during
field days. The other out-
put of the second coaxial
relay feeds into a comb
generator containing a step
recovery diode (SRD) or
snap varactor which gen*
erates the appropriate
X-band harmonic.
The comb generator
receives its power for har-
monic generation by set-
ting the CLB transmit out-
put to 12:250 MHz, which
is multiplied up to 147
MHz through the VHF
Engineering 1.5 Watt two
meter transmitter. The out-
put comb from the SRD or
snap varactor produces a
usable output at 10.242
GHz. This output is fed in-
to a microwave hybrid mix-
er and mixed with a sample
of the Gunn oscillator's
output through a direc-
tional coupler to produce
an i-f output at 47.45 MHz.
A VHF Engineering six
meter front end set at 47.45
MHz serves as the second
conversion to the 10,7
MHz i-f input of the two
meter receiver i-f amplifier
and associated circuits.
The i-f input of the two
meter receiver can be
switched to either the two
meter front end or the one
on six for liason use, or for
synthesizing the X*band
transmitter. The six meter
LO input comes from the
12.250 MHz output of the
GLB through a tripler. The
10.7 MHz i-f is further con-
verted down to 455 kHz
where the discriminator
output voltage is fed into a
servo amplifier. The servo
The X'band phase locked rig set up on the kitchen table photo studio. The meter on the
left is used for tuning up. The GLB sets on top of the two and six meter receiver. The 1.5
Watt two meter rig is in the same chassis. The box that hangs on the right-hand detector
mount is a preamplifier. On the left, a small box contains the servo and modulation elec-
tronics.
electronics are complete
with an integrator and are
used to tune a varactor
mounted in the Gunn oscil-
lator cavity. Thus, the
system becomes locked to
the GLB channeiizer,
A second receiver is
made up by modifying an
old Radio Shack two-band
Patrolman police monitor.
This receiver, which is
The rf plumbing stripped of at! the electronics. On the right is the receiver detector which
feeds into a circulator. On the teft is a Cunn oscillator. The large square unit fastened to it
is the varactor used to tune the Cunn oscillator.
65
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WAVE
GUIDE WALL
PLACE REXOLITE
SPACER iN
LAUNCHER BOX
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032 BRASS WASHER
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SOLDERED IN PLACE
084 HOLE
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tOMS OENERATOR DIODE MOUNTING DETAIL
tunable (or frequency con-
trolled by the CLB syn-
thesizer through the same
tripler used above) is used
as the receiving i-f system
at 26,75 MHz when locked
to, or at, frequencies that
can be tuned across the
X-band range. Modifica-
tion requires the addition
of a preamplifier that
w/ou!d match the output of
the receiving mixer to get
the noise figure down to a
useful level. This receiver
does not have any band-
narrowing filters in its i-f
system (10.7 MHz) and is
ideal for the searching that
is required for stations that
obviously will not be on
your frequency. It also has
12'Volt capabilities which
allow it to work in the car.
This receiver could be
replaced by another six
meter converter and VHF
Engineering i-f audio
module as is used in the
two meter setup. Until this
change is made, we wilf
continue to make our con-
tacts With the old police
job which so far has given
excellent results over the
short-path QSOs with
WA1NWF. Its bandwidth is
wide enough that once the
signal is captured, small
F\^. 2. Harmonic genera
drifts can be compensated
for by readjustment. It is
not an easy task to make
contact with another sta-
tion unless you both are
locked on the same fre-
quency, so a tunable
receiver, for the time be-
ing, is a must. Another
amateur, who is using a
similar idea, has a police
scanner in use as the
search receiver. The crystal
oscillator has been
modified to be tunable and
is scanned in the same
manner that it would be if
it were crystal controlled.
This provides a fully-
automated scanning sys-
tem so he can drink his
Coors^^^.
The microwave plumb-
ing used in this set is com-
posed of pieces either
gathered from surplus
houses or constructed by
the author. It is quite a task
to make a Cunn-diode
oscillator/mixer assembly
such as the one used in this
system. The frequency con-
trol of the oscillator is ac-
complished by voltage-
controlling a microwave
varactor located within the
oscillator cavity. A ferrite
isolator, acquired from a
police radar set, and incor-
tor construction details.
porated with the tunable
crystal mount completes
the mixer half of the unit.
The construction of these
devices is a formidable
task unless a well-equipped
microwave test facility and
a targe amount of machine
work can be accomplished.
Therefore, it would be
worth the constructor's
time if he incorporated a
Micro wave Associates
Cunnplexeri'^ which has
all three of these items, as
well as an excellent horn
antenna.
The Comb or Harmonic
Generator
Snap varactor or step
recovery diodes are names
given to these semiconduc-
tors by two of the leaders
in this field. Undoubtedly
there are other names, but,
since this article started
with these nomenclature,
we will keep them. These
semiconductors have a
property which, regardless
of what it is called, per-
forms as follows: An
epitaxial diffused varactor
is designed to store a
charge when it conducts in
its forward direction. It
conducts for a very short
time until this charge is
pushed out by the driving
rf signal. Then the conduc-
tion ceases very quickly.
This is called the "lifetime"
and is a way to measure the
period that the varactor
will store a charge, and the
snap-time (or step-time, as
it is also called) ceases.
These diodes sometimes
require an external bias,
but ours will be used in the
self-bias mode.
The effects described
produce a series of pulses,
which cause, in our gen-
erator, the first cavity to
"ring/' producing a train of
damped waves at a micro-
wave frequency. The out-
put of the "ringer" cavity is
then directed into a second
cavity, which, by virtue of
its high Q, propagates a
more CW-like signal to its
output termination. In the
unit described for con-
struction, these cavities
are coaxial for the first two,
and waveguide bandpass
cavities for the last two.
Needless to say, much care
will be required in the con-
struction of the unit. See
Fig. 2 for details.
The diodes can be ob-
tained from many manu-
factufers. Two are listed,
with references, at the con-
66
elusion of the article. The
two references are certain-
ly worth the reader's in-
spection in regard to future
generator construction.
The parts required for
this section are easily ob-
tained. They consist of a
three-inch section of cop-
per "small X" waveguide
(RG-52/UX two Va-inch i.d.
sections of brass pipe with
1/32-inch wall thickness,
and four end-plugs for
these pipes that must be
machined and drilled to
size. Also required are a
cover, UC-39B/U, which is
soldered to one end of the
waveguide, and a small
brass box which is con-
structed from another sec-
tion of the same wave-
guide Construction of this
unit should be easily ac-
complished from the
mechanical drawings The
iris coupling consists of
holes found near the bot-
tom of each coaxial cavity.
The plate used to cover the
choke flange, which is the
output of the harmonic
generator, is the frequency
controlling element of the
fourth filter, a waveguide
bandpass filter.
The tuning screws found
on the top of the wave-
guide must have the large
plates loaded to make sure
that firm connection is
made to the wall of the
waveguide. Once adjusted,
the jam nuts can be firmly
set since no further adjust-
ment will be required, but
be sure that the nuts
squeeze into the lock
washers.
Begin construction of
the SRD assembly by mark-
ing off the two holes for
the circular cavities- These
two holes are drilled
through the waveguide
ivalls and are spaced dou-
ble the thickness of the
pipe wall, so the material
left in the edges of these
two botes will be removed.
It is best to drill both holes
mth a smaller drill and
:hen line-ream out the re*
Tiainder of the material un-
til a tight fit is achieved.
The two pieces of Vi-inch
tubing should now touch
each other on one side.
Insert each of the cavity
tubes into the holes so that
the two iris slots near the
bottom of each tube face
each other. At the center of
each of these cavities, the
holes shown in the draw-
ings should face the open
ends of the waveguide.
These are the exit irises of
each of the coaxial filters.
Next, install the bottom
plug which should be the
machined piece which
makes up the coaxial post
for each cavity. All of these
pieces should be turned on
a lathe so that they provide
a very tight fit into the tub-
ing. Make sure that the
plug ends of these cavities
are parallel to the bottom
wall of the waveguide and
that the iris holes near the
bottom are facing each
other. Install the top plugs,
which have the tuning
studs, into the top of each
coaxial cavity. These, too,
should be machined for a
very tight fit.
This view shows where the piston capacitor is located. The
SRD is in the foreground near the inspection plate.
When all of these parts
are aligned and you are
sure of the correct posi-
tioning as shown in the
drawing, gently heat the
assembly to a temperature
that will cause soft solder
to run, apply flux to each
joint, and run in the solder.
Use only a very small
amount of solder; just
enough to make a good
electrical joint. Let the unit
cool before attempting the
next step.
On one end of the wave-
guide, install the inside rec-
tangular iris plates as
shown. Then install the
output flange on the end of
Side view of the SRD comb generator which provides the harmonics for mixing. The two
tuners on the top of the waveguide are inserted into the tops of the coaxiat cavities. On
the bottom, the SRD mounting stud is in view and just behind it is the piston capacitor
tuning plug.
67
Front view of the comb generator shows the second inter-
n^l iris which forms half of the bandpass filter. The large
flat plate near the flange is the output iris which makes up
the second half of the bandpass fitter. It is held in place by
the mounting screws which fasten the whole unit to the
directional coupler.
the waveguide. Again heat
the assembly, flux the iris
plates and the flange, and
apply solder. Care should
be taken not to overheat
the waveguide such that
the cavity assemblies are
disturbed. A four-cavity
assembly has been com-
pleted and is now ready for
installation of the SRD and
rf launcher.
Examine the drawing of
the comb generator diode
mounting detail on Fig, 2.
This assembly and the driv-
ing coil which is tuned to
two meters make up the rf
launcher. These compo-
nents must be carefully
assembled prior to install-
ing the SRD in place. This
diode is a small pill which
has a form factor known as
"style 31" in the micro-
wave semiconductor trade,
To install it, place the end
with the large flange
near the small circular pro-
trusion into the end of the
prepared 8-32 screw, after
the screw has been run up
through the threaded bush-
ing so that it's just visible.
The hole in the end of this
screw should accept the
diode with a little
resistance. Do not push
sideways on the diode or
you will fracture the seal.
When installed, run the
screw into the bushing so
that the other end of the
diode engages with the
launcher line. The launcher
should have a matching
hole drilled into it in the
correct place. DO NOT
tighten the diode — just a
firm fit will do, Alt of this
activity is accomplished
through the inspection
hole on the top wall of the
waveguide. The diode can-
not take much heat, so any
soldering of the launcher
rod must be done before its
installation.
When the assembly is
completed, replace the ac-
cess plate and connect the
output of the two meter
gear through the atten-
uator shown in the draw-
ing. This pad will reduce
the output of the transmit-
ter to about 0.5 Watts
which is all that is required
to drive the diode. It can
take only slightly more
power, so take care!
Put the output of the
comb generator into a
wavemeter and detector.
The detector will have to
drive a very sensitive meter
if the output is to be seen.
There should be at least 20
microamperes output and
should be indicated at the
frequency described.
If a smaller indication is
shown, it should improve
when the tuning screws on
the top of each cavity are
adiusted. The frequency
meter should be left on the
prescribed frequency of
10J40 GHz. Adjust the
output coaxial cavity,
which is the one nearest to
the flange, for maximum
and then peak-up the
ringer. It is possible to be
147 MHz higher or lower
since this is a comb gen-
erator, so watch the fre-
quency meter. If a spec-
trum analyzer is available.
as was to the author, little
problem will be encoun-
tered in adjusting for peak
output, but if not, it will re-
quire judicious observa-
tion of the frequency
detected by the frequency
meter cavity. When it is
correctly adjusted, one
very large peak right on fre-
quency can be measured.
When it is slightly off peak,
a number of peaks will be
observed when the fre-
quency meter is tuned
through the desired out-
put. With a little practice,
full output wil be assured.
When adjustments are
completed, be sure to
tighten the two jamb nuts
that are on the tuning
screws. No further adjust-
ment will be required if it is
done right as these nuts do
not work loose.
We are now ready to try
to lock up the system to
the channelizer, hook up
the harmonic generator to
the system, and determine
that all of the servo con-
nections and indicators are
in order- Turn on the sys-
tem and look at the center
scale tuning meter. It
should be right on the tine.
To prove it is locked, and
will also lock again, open
the lock/unlock switch and
watch the meter swing one
way or the other and then
snap back to center when
the switch is closed. With
the lock switch closed on
the search receiver, you
should be able to hear
yourself when you speak
into the mike. Full duplex
can be used on this fre-
quency.
The circuitry shown for
the power supply, servo
electronics, and modulator
are simple and should give
little trouble. The output
from the VHF Engineering
i-f strip discriminator
should be used as recom-
mended from the manufac-
turer for driving a micro-
ammeter. The meter,
however, is replaced with
the circuitry shown, and
then the meter will be con-
nected to a new set of con-
nections.
Modulation of the varac-
tor requires a little care.
Very little modulation is
needed as full FM-is used.
If you are working a station
that uses a wideband re-
ceiver, then a greater swing
will be required. However,
if you are working one that
has a system like the one
described, then the devia-
tion must be adjusted to fit
his receiver using the
deviation control
Tests throughout the fall
have gone on with this rig.
It is portable, by virtue of
its several boxes, and gets
hauled up on Prospect Hill
in Waltham on Sunday
afternoons. Prearranged
contacts have been made
over 30-mile paths with lit-
tle difficulty.
Plans for another rig of
the same type to be used
for expeditions are in the
works. It would be inter-
esting to see what can be
done at greater ranges,
which I know are done
commercially, It's quite a
thrill to hear full quieting
on top of a hill with a lot of
old junk plumbed together,
1 hope you will enjoy the
same results on your own
expeditions. ■
References
Hewlett-Packard Application
Notes #920 and #928
Step Recovery Diode, HP
5082-0830
Microwave Associates Snap
Varactor, MA 43004
68
CALL TOLL FREE
III
I
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Ill
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LIST PRICE OlMiy S549
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« • •
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Monday - Friday 8 a.m. - Midnight
Saturday 8 a^nri- - 8 p.m,
Sunday Noon - 8 p.m.
master charge
Communications Center
The Radio Store
t^CS€
443 N, 48th, Lincoln, Nebraska 68504
In Nebraska Call (402)466-8402
SlNKiMIRlCARe
Header Service— -s&e page 323^
69
Faces, Places
In recognition of her outstanding support of radio amateurs in
their state, Alabama hams presented this plaque to Mrs. Edith M.
Parf^erat the Central Aiabama Hamfest In September. Mrs. Parker
was in charge of issuing amateur radio car tags from 1962 untif her
retirement in July of this year.
At the Veteran Wtreiess Operators Assoctafion's annual banquet
in New York on May 20, Jack R. Popple (left) presented the Marconi
Memorial Gold Medal to Bob "Whitey" Doherty KlVV for his ef^
forts in conjunction with the Marconi 75th Anniversary Amateur
Radio Commemorative Station, KMICC^
T. S. Ganesh VU2TS (left) and his seventeen-year-otd SWL nephew,
Janardhan, competed in August's 1000-mtte Karnataka-tOOO
Motor Raily, organized by the Bangalore (India} Motor Sports Club.
What you can't see in this view is the sign painted on the bike's
seat: *'73 FROM RADIO AMATEURS/'
Craig McCartney WAdDRZ/9 was one of the Chicago Area
Radiolefetype Repeater System's members who manned the
booth at the Chicago FM Club's annua f Radio Expo this past falL
These central Ohio amateurs helped raise over two thousand
doilars for charity last spring, when they assisted with the fourth
annual Reynoldsburg bikeathon. Pictured left to right are Dr. B.
Morgan He f I in WA8UVR, Randy Mitchell WDBAXY, Vernon Holland
WDBNAU, Joe Hahn WD8NBA, Mait Brown WB8WKZ Dick Carr
WA4BIH, Dennis Roe WA8HPW, John Voifmer WB8U!F, and Mac
Ceschiat K8ZQS.
W
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FIVIS-25
Ten Front-Panel-Programmable Memory Channels
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Same Fantastic Receiver/Transmitter as System 3000A
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Q O O O O O O
l^ R&ader Service— see page 323.
71
from pagt 28
continents = 5 points. Coo-
tacts with HQ station GW8WJ
or GW6AQ count 25 points.
Total score is toiat number of
QSO points times number of
prefixes worked (as per WPX
award rules)*
ENTRiBS:
Send logs not later than Jan,
31 to: Peter Lumb G31RM, 14
Linton Gardens, Bury Saint Ed-
munds» Suffolk IP33 2DZ,
United Kingdom. IRCs appre-
elated for contest resutts-
CONNECTfCUT QSO PARTY
Starts: 2000 GMT Saturday^
December 2
Ends: 0200 GMT Monday,
December 4
Rest Period: 0500 to 1200 GMT
December 3
The Candle wood ARA mvites
all amateurs to participate in
the annual CT QSO party.
Phone and CW are considered
to be the same contest. Sta-
tions may be worked once on
each band and mode, Including
OSCAR as a separate mode.
Novices will please identify
themselves by "/N" unless ''N"
is part of their calL Out-of-state
portables and mobiles operat-
ing in CT are requested to iden-
tify themselves as such. CT
mobiles operating in other than
their home counties will
receive special certrficates pro-
vided they make at least 20 out-
of-state QSOs. Mobiies count
as a separate station in each
county. Counties certificates
wril be awarded to each station
working ail 8 CT counties,
EXCHANGE:
QSO number, RS(T), and
ARRL section or CT county.
FREOUENCIBS:
SSB--3927, 7250, 14295,
21370,28540-
CW— 40 kHz up from bottom
of each band.
Novices— 3725, 7125, 21125.
28125.
SCORING:
Non-CT stations multiply
total number of CT QSO points
by number of CT counties
worked (8 max.). CT stations
multiply total number of QSO
RESULTS OF 10-10 SUMMER QSO PARTY
JULY 1 5-1 e, 1978
TOP
KflGU
KQLT
WOPEL
TI2NA
WA5JDU
WUCP
W40RH
N9CP
WD5CSK
K5CWB
TEN
1 317/2358
805M481
78in433
771/1356
687/1272
649/1215
648/1186
613/1137
583/1104
582/1089
CHAPTER STANDINGS
1, Colorado
2, Minute Man
3^ Bay Area
4 Land O' Lincoln
5. Gateway
6. City of Lights
7. Plainsman
8. North Star
9. Sky Blue Waters
10. White House
11081/20704
5629/1 0721
3839/7201
2934/5455
2740/5326
2447/4607
2202/4196
2164^4125
2115/4060
2081/3940
as.
1.
z
3.
4.
5,
6*
7.
8.
9.
•
KG
KH
KA
DtSTRiCT LEADERS
WA1UZH 505/953
K2DEG
WB3FAF
W40RH
WA5JDU
WB6JPY
K7PV2
WOaDPB
WA9PQY
KTCU
407/751
418/769
648/1 1 86
687/1 272
444/604
470/833
236/446
464/850
1317/2358
KH6ITD/KG6 107/144
KH6JTL 389/693
KA6HF 90/132
OX LEADERS
Central America & Caribbean
TI2NA 771/1356
South America
LU6DWZ 231/418
Europe
DF1XG 124/140
Asia
JA3X0G 61/105
New Zealand
ZL1 BOD 260/440
Australia
VK2NET 383/661
CANADtAN LEADERS
VE1 VE1BNN 508/910
VE2 VE2DZ0 324/603
VE3 VE3JAR 271/519
VE4 VE4ADG 219/414
VE6 VE6B8C 54/102
VE7 VE7CMT 255/459
points by number of ARRL sec-
tions and provinces. Additional
DX contacts count for QSO
points, but only one DX
multiplier la allowed overall.
W1QL the club station, wiil be
operating CW on odd hours
and SSB on even hours, and
counts as 5 points on each
band and mode. Novice QSOs
count 2 points while OSCAR
QSOs count 3 points each.
ENTRIES:
Logs must show category,
date, time (GMT), calls,
numbers, mode, bands, QSO
points, and claimed scores.
Separate certificates tor single
and multi^operator stations,
and all logs should show which
class applies. Enclose a large
SASE for results. Send lo^s,
postmarked by Jan. 3, to CAR A,
c/o Fred Porter WiVH, 169
Carmen HMI Rd. #2, New
Mtlford CT 06776.
FLATLANO FARMER 10 X
QSO PARTY
Starts: 1200 GMT
Sunday^ December 3
Ends: 2400 GMT
Sunday, December 3
This is the f irsi DX QSO party
sponsored by an individual
chapter of the 10-X tnterna-
tionai Net, Inc., the Flatiand
Farmer Chapter, Score one
point per QSO if said station
does not have a Flatiand
Farmer certificate, two points If
they hold a Local or Associate
certificate number (station will
have an "L" or "A" after the cer-
tificate number). All first state
or first DX certificate holders
will be worth 2 points for a
QSO. If the station is a Charter
member certificate holder,
score 3 points per QSO.
SPECIAL:
On this date and this date on-
ly, any station who does not
hold a Flatiand Farmer cer*
tificate can qualify for one by
having two QSOs with any two
stations who have a Flatiand
Farmer certificate, regardless
of whether that station is a
Charter* Local, or Associate
member. Slalions wishing to
obtain their basic certificate
should send request, listing the
two QSOs, $1.00, and two first
class stamps to: Lou Reik
WB9YJE, 804 Commercial
Street, Danville IL 61832,
ENTRIES:
Logs must have date, call let-
ters, name, QTH, 10-10 number,
and Flatiand Farmer number, if
any. Logs to be postmarked by
Jan. 15 and mailed to: Mike
Reik WB9YJF, 304 McKinley
Street. Westville *L 61883.
Results of the contest will be
published in the spring 10 = 10
bulletin, and other amateur
publications.
AWARDS:
A certificate wIM be Issued to
the 1st, 2nd, and 3rd place win-
ners in each US call area, in-
cluding KH6 and KL7. All other
call areas will be considered
DX and a certificate will be
issued for 1st, 2nd, and 3rd
place. In addition, a special
award will be given to the per-
son anywhere in the world who
scores the highest point total.
F tail an ft Farmer ph^pter
10-)i/friternational NeClnc.
Amateur
nrrtcATE isissutc
fOR PfiaVEN AND SIPK^ERE EFFOflT^TDftOMQtt
ffll£Mll&f IP, laCUtnVILl, AMD Oin^AMDING COMMUNICAflOPifi
Off It^HETEftS,
72
There will be no multipliers
used or consideration given for
multi-operators,
The normal requirements for
the award are a total of 10
points as follows: Charter
members (#01C-24C) = 5
points; Local members
(#101L-500L) = 2 points;
Associate members (#501 A and
up) = 1 point. Submit your re-
quest with $1.00 and two first
class stamps to the certificate
manager, Lou Reik WB9YJE
(see above for address),
SODBUSTER AWARD
The Sodbuster Award Is the
newest award. It is a 3- x IVt-
inch self-stiGi<ing award that is
to be placed on your basic cer-
tificate. This award requires 50
points. This award in itself will
be worth 3 points. The point
breakdown for the Sodbuster
Award is as follows: Charter
members are worth 5 points;
Local members are worth 3
points; first staters and first DX
are worth 2 points; aJI other
Associate members are worth 1
point. Submit your request
along with 3 first class stamps
to the certificate manager, Lou
Reil<WB9YJE.
For those interested In ttie
Flatland Farmer Chapter, it
meets each Sunday night at
1900 hours local IL time on
28/745 MHz,
ARRL 10 METER CONTEST
Starts: 1 200 GMT
Saturday, December 9
Ends: 2359 GMT
Sunday, December 10
The contest is open to all
amateurs worldwide. All QSOs
must take place on 10 meters,
and OSCAR QSOs are valid.
Each station can be worked on
phone-to-phone and CW-to-
CW, and anyone can work
anyone. All CW contacts must
be made between 28.0 and 28.5
MHz, unless working through
OSCAR. When operating on 10
meters, please avoid the
OSCAR downlink frequencies.
CLASSES:
Entries will be classified as
either single- or multiple-
operator stations. Multiple-
transmitter stations are not
allowed.
E\OHAHGE:
All W/VE stations will send
RS[T) and state or province.
Others will send RS{T) and con-
secutive serial number starting
with 001. Stations that are not
land-based will send RS(T) and
ITU Region (1, 2 or 3). The
District of Columbia is counted
as part of Maryland.
SCOR/NG:
Each completed QSO counts
2 points, or 4 points If with a W
or K Novice. The multiplier is
the sum of the total number of
states, Canadian call areas
(max, 9), ARRL countries (not
US or Canada), and ITU regions
from non-tand-based stations.
Final score is the sum of the
QSO points times the total
multiplier.
AWARDS:
A certificate will be awarded
to the highest-scoring single-
operator station in each sec-
tion, Canadian call area, and
foreign country. Region awards
for non-land-based stations
and awards for multi-operator
and Novice stations will be
issued if warranted,
FORMS:
It is suggested that contest
forms be obtained before the
contest from the ARRL, 225
Main St., Newlngton CT 06111;
include an SASE. Checksheets
are not required, but a penalty
of 3 additional contacts will be
made for each duplicate con-
tact.
These rules were taken from
last year*s contest. For com*
ptete rules, see the November
Issue of QST,
1978 CW CHRISTMAS PARTY
The Society of Wireless
Pioneers (SOWP) Is planning a
membership Christmas on-the-
air CW QSO Party for the
weekend of December 16 and
17, 1978- The party will cover
the full GMT period to allow
members around the wortd to
participate.
All members with amateur
licenses are being encouraged
to take part. The cail will beCQ
SOWP. While there will be no
certificates or other awards
given — everyone who takes
part will be a winner by having
an opportunity to renew old
friendships, establish new
ones, and continue a camara-
derie developed over the years.
Suggested frequencies for
the party are between 50 and 60
kHz up from the tow end of each
amateur band. Novices should
consider the middle of each
Novice band. Additional infor*
mation about this party and the
Society can be obtained from
the Party Coordinator, Bill
Willmot K4TF, 1630 Venus
Street, Merrttt Island FL 32952.
ARRL STRAIGHT KEY NIGHT
0100-0700 GMT
Monday, January 1
Check QST for any changes
in the rules!
Basicaily, rules require the
use of a straight key only. Send
*'SKN^' instead of ''RST'*
during QSOs, to help identify
contest stations. On 80-40-20
meters, try 060 to 080 kHz up
from the bottom edge of the
band. On Novice bands, try 10
kHz up from the bottom of the
Novice band. After the contest
period, send a i ist of calls of the
stations contacted during the
contest period, plus your vote
for the best fist heard. Please
mail entries as soon as possi-
F""^
THE 73 MAGAZINE 10 METER AWARDS
The return of vigorous solar activity means that 10 meters
Is once again a band to be reckoned with, or Sot's 11 -year
cycle of sunspot production Is about to hit a peak, with the
result that QRP 10 meter DX Is possible.
Now's the perfect time to convert that old CB rig to 10 (or
buy a brand new one from Bristol or Standard) and join the
fun. WeWe had many articles showing you just how easy a
OB-to-10 conversion really Is. To give you an added incentive,
73 is offering two nifty Certificates of Achievement for 10
meter channelized communications.
For domestic types, there 1$ the 10-40 Award. This one
should be pretty eas^—rjust work 40 of the 50 states. The DX
Decade Award goes to DXers who work 10 or more foreign
countries with a channelized IOmeter rig. We have endorse-
ment stickers, too— the whole bit.
To give everyone an equal shot at award #/, only contacts
made October 1, 1978, or after will be valid.
Well, don't just sit there. Get out your soldering iron, order
some crystals, and put that CB rig on 10. This is going to be
fun, so don't miss out!
RULES
1) ATI contacts must be made in the 10 meter amateur band
using channetized AM equipment. Both converted Citizens
Band equipment and commercially-produced units (such as
those available from Bristol Electronics and Standard Com-
munications) may be used.
2} To be eligible for award credit, all contacts must be
made October 1, 1978, or after,
3) The 10-40 Award is available to applicants showing proof
of contact with stations in at least 40 of the 50 United States.
A special endorsement sticlcer will be available to those
working all 50 states.
4) The DX Decade Award is available to applicants showing
proof of contact with at least 10 foreign countries. Endorse-
ment stickers will be awarded for 25, 50» 75, and 100 coun-
tries.
5} A log of stations worked, with the date, time, and type of
equipment used for each contact, must be submitted when
applying for each award or endorsement.
6) Each application for an award or endorsement must be
accompanied by a signed statement that all claimed con-
tacts are valid. No QSL cards need be sent, but they must be
in the possession of the applicant.
7) To cover costs, a fee of $5.00 must accompany each
application for the 10-40 or DX Decade Award. The fee for
endorsement stickers will be $2.00 each.
8) All award applications should be mailed to: Chuck Stuart
N5KC, 5115 Menefee Drive, Dallas TX 7S227.
ble to the ARRL, 225 Main
Street, Newlngton CT 06111,
SLOW SCAN
TELEVISION NEWS
Amateur Television Maga-
zine is now offering a series
of award certificates for
SSTV activity ranging from a
basic award through several
levels of difficulty to a Master
Scanner Award. The beginning
level certificate requires the
SSTV operator to have con-
firmed five SSTV contacts on
each of any five ham bands, a
total of 25 contacts. The bands
used for all the levels may be
any combination of the contes-
tant's choosing. Additional
awards are available for work-
ing increasing numbers of sta-
tions on increasing numbers of
bands. Each certificate is 8x 11
inches and suitable for fram-
ing. ATV /[Magazine m\\ publish
the names and calls of each
certificate holder as issued
with each award numbered
consecutively. The various
award levels are as follows: 5
SSTV QSOs on each of any 5
bands = 25 contacts total; 6
SSTV QSOs on each of any 6
bands = 36 contacts total; 7
SSTV QSOs on each of any 7
bands = 49 contacts total; 8
SSTV QSOs on each of any 8
bands = 64 contacts total; 9
SSTV QSOs on each of any 9
bands = 81 contacts total; 10
SSTV QSOs on each of any 10
bands = 100 contacts total.
In addition to the normal fre-
quency bands, the use of
OSCAR may be used as 2
bands for any two OSCAR
modes, i.e., 5 contacts via
450/144 OSCAR would count as
1 band for the basic certificate.
Applicants should send
proof of QSOs and $1.00 for
postage for each award to:
SSTV Master Scanners
Awards, PO Box 1347, Bloom-
ington IN 47401. Allow two
weeks for processing and
award preparation. SSTV con-
tacts must have been made
after Sept. 1, 1978, to qualify!
73
DX
from page 20
W4KPQ daily on 14210 at
1200Z. QSLlo K4MQG.
South Shettands— CE9AT
CE9AT meets WA2HNE daily
on 21335 at 1600Z. Tune in
about a hatf hour earlier to get
your calf on the list. US, VE, and
XE stations can QSL to
CE2BI0, Antarctic Department,
Naval Post Office, Valparaiso,
Chile, Include an SASE with
16$ USA postage.
Svalbard— JW7FD
Rag has been showing in the
14200 to 14250 slot on twenty
meters after 1000Z. Between
1700 and 1800Z he moves to fif-
teen meters, sometimes visit-
ing the Afncana Net on 21355.
QSLtoLASNM,
Tonga— A35CR
Claris plans to be in Tonga for
about a year as a member of the
Peace Corps. Look for him
around 14240 most days after
0700. QSL to Box 147, Nuku*
Alofa, Tonga.
Walvis Bay
The Northern California DX
Foundation has indicated a
willingness to supply a beam
and equipment for an operation
if it can be assured that it wiil
be a duly licensed operation,
there being some doubt
whether one of the previously
heard stations did have a valid
Walvis Bay license. South
Africa continues to insist that
Walvis Bay is their territory and
has been for over 100 years,
Namibia, on the other hand,
has only been administered
since its capture from the Ger-
mans during World War L This
will al! be worked out eventual-
ly, so work them if you hear
them and worry later.
Rhodes— SVC
SVOWTT has been trying to
get permisston from the Greek
licensing authorities for an
operation from Rhodes Island
in the Dodecanese group.
While the US has a reciprocal
licensing agreement with
Greece, it is still difficult to get
permission to operate from
Rhodes and just about impossi-
ble to get permission to operate
from Mount Athos. In the mean-
time, Jack can usually be found
around 7003 from 2230 and
21003 after 0300Z. Give him a
call and you'll get the latest
word on Rhodes.
United Arab Emirates— A6XB
A month or so back, we
reported that all A6 operations
had ceased, Apparently this is
not completely true. Vernon
Dameron K1DRN, QSL mana-
ger for A6XB for the past seven
years, says that from the QSL
cards he is receiving for A6XB,
there is still plenty of activity.
CW operation is completely for-
bidden though, so any A6s you
hear on CW are phony.
Brunei— VS5XU
Look for this one from 1300Z
daily in the 14200 to 14210 slot.
A good operator, he stays away
from lists and generally works
by call districts. QSL via
DL1DL
East Malaysia— 9M&HG
CW contacts can be made
with this rare one near 14003
around 13002 and near 21025
after 1500Z. QSL to Horace
Cray, PO Box 2242, Kuching,
Sarawak, East Malaysia.
iraq— YilBGD
Magid seems to have settled
into a regular routine operating
transceive on 14310 after
2100Z. Although handicapped
by a weak antenna and low
power, he continues to do a ter-
rific job and show a lot of pa-
tience, seldom losing his cool.
At the end of each Friday ses-
sion, a list is taken by districts
for the following week's ses-
sion, QSL to Box 5864,
Baghdad, Iraq.
Lord Howe island— VK2AGT
Dick can usually be found
around 14225 from 0600 to
0700Z, especially on Wednes-
days. He is looking for Nebraska,
Utah, and Wyoming to fill out
his WAS. QSL to Dick Hoffman,
Lord Howe Island, N.S.W. 2829,
Australia.
WlongoHa- JT1BF
On almost daily from 1100 to
1400Z. UWONE is the list-taker
and MG. QSL to PO Box 6,
Vladivostok, USSR.
BITS AND PiECES
The Johnson Island Radio
Club has received a number of
cards for contacts with KJ6DL,
operator Henry, during the
period July 18 to August 1.
KJ6BZ reports that this station
is unknown and cards are being
returned.
A show of hands at the DX
Forum at DXPO 78 showed that
98% fo those present favored
making the DXCC awards pure
by disallowing any cross-mode
contacts- A majorHy also
favored dropping the ''separate
administration" clause from
the DXCC country criteria. This
is the clause that gave us
4U1ITU/4U1UN and Sable
Island.
There are three different
groups from as many countries
planning future Bovet action.
The TF6M operation gar-
nered 10,800 QSOs in 85 hours.
They worked 121 countries on
five continents, including all
states but Hawaii.
Some new prefixes have
been announced. These In-
clude J4 for Greece and J3 for
Guinea Bissau.
Congratulations to W50PG,
WA5KGQ, and WB50J0 for
providing a vital communica-
tions link to the Double Eagfe If
during the first-ever trans-
oceanic balloon crossing. Ama-
teur radio proved to be the only
method of communications
when a faulty transmission
cable aboard the balloon
knocked out the commercial
frequency equipment* A spe-
cial QSL will be sent to all those
lucky enough to make contact.
By the time you read this, the
new beam supplied by the Nor-
thern California DX Foundation
should be up and in operation at
4U1UN.
As of the end of July, total
licensed amateurs in the
United States numbered
348,561, up 8,5% in the last
year.
Jacky F6BBJ, one of the top
French DXers, has been look-
ing toward the Red Sea and the
islands off East Africa for
some possible DXpedition ac*
tion around the end of the year.
Other Frenchmen closer to
home have been eyeing St. Bar-
thelemy Island north of
Guadeloupe for possible DX-
pedition action if DXCC ap-
proval can be obtained.
Volunteer examiners are
needed by the FCC to ad-
minister amateur examina-
tions to blind and physically
handicapped applicants. Con-
tact your local FCC office for
more information.
Rules and application
blanks for the World Radio
W-100-N, Worked 100 Nations
Award, can be obtained by
sending an SASE to World
Radio, 2120 28th Street,
Sacramento CA 95818.
The DXAC recently vetoed
DXCC status for the Republic
of Sealand. The Republic of
Sealand is an old British air-
defense radar tower similar
to a drilling tower, located just
off the English coast. H was
purchased by a group hoping
to turn it into a gambling
casino. They issued passports,
minted stamps, and even had
their own currency. Apparently
It was a good idea because
another group invaded Sealand
and captured It by force. The
original group then rearmed
and recaptured Sealand and
imprisoned the invaders' leader.
After all this, the DXAC still said
no.
Bill A35WL will be returning
to New Zealand soon, but while
on Tonga, he has been conduc-
ting radio classes. Hopefully,
one of the graduates will
remove A35 from your needed
list.
Last month, we mentioned
the possibility of a future DX-
pedition to Oneo Island in the
South Pacific, For those of you
trying to find it on your map,
look northwest of Pitcalrn and
west of Henderson Island.
There is a report that Iraq
and Saudi Arabia have signed
an agreement concerning their
neutral zone, so if you haven't
worked 8Z4, now is the time.
FG7AS does QSL— some-
times a year late, but he does
QSL. On that same subject,
there is a report out of Moscow
that the USSR QSL Bureau is
running out of funds and must
cut back on their manpower.
This win mean an even longer
wait for those needed Russian
QSLs.
HH2MC advises that there
are now 17 members in the Port-
au-prince Radio Club. Haiti has
applied for lARU membership and
is waiting for action to be taken on
its application.
Baruch 4Z4TT plans to head
back into the Pacific before
next summer. VR1 is a possible
stop. Let him know if you have
any favorites.
Congratulations to K1DG on
winning the 1978 Bermuda DX
Contest and the all-expense-
paid trip to Bermuda that goes
to the winner. K3DH was the
top scorer in the third call
district for the 5th straight
year.
Alex 3B8DA reports making
better than 10,000 contacts
from 3B9 and some 5,000 from
386.
The September issue of Na-
tional Geographic had an arti-
cle on JAIQFW's solo walk to
the North Pole,
KM6FC left Midway Island
last October and headed for
Maine. Len logged better than
23,000 QSOs during his stay.
Two operators remain at
KM6BI. KM6BI contacts before
July, 1978, go to W8TIZ; after-
wards, to W5RU at the Delta DX
Association.
It iS reported that the VU
Bureau has gone bankrupt and
folded operations. It might be
prudent to seek a direct QSL route
ifor VU contacts.
It seems there will be no
ZS6QU/ZS3 QSLs forthcoming.
ZSGQU first reported that an
office girl had accidentally
dumped the incoming QSLs in-
to the wastebasket. Those who
tried again received only
silence for their efforts.
Jack K90TB has ceased QSL
operations for FPBDX/FPSML
and FP8HL. He will still help
you for contacts with FP8DX/
FP8ML and his own call,
74
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^ Bead^f S«fviG9 — See page 323,
75
FP©YY.
VU2ANI became a silent key
In 1976 and several are search-
ing for his logs. K6TWT doesn't
have them.
WCBW is trying to get confir-
mation on contacts wHh
CR60B in November. 1975, and
D2ACK in July, 1976. Any
assistance would be ap-
preciated.
NOVICE CO RMER
Last month, we talked about
the incoming QSL bureaus and
how to make sure you received
any QSL cards directed to you
via that route. This month, we
will discuss the best way to
send QSLs. Whether you QSL
direct J via the bureau, or
through a QSL manager, you'll
want to be able to pick the best
route for that particular card.
Best route In this case means
the one that is the most likely
to produce a card in return, not
necessarily the cheapest or
even the fastest. Remember,
confirming the contact is the
result we are after.
QSL managers are almost
always the best route to go. If
the statton you work has a QSL
manager, then you can usually
be assured of a fast confirma-
tion. Sometimes problems
develop like logs getting lost
or an inexperienced QSL
manager not realizing the
scope of the task he has under'
taken, but generally QSLing via
a QSL manager witi produce
the fastest results. Mere is the
way it works: After looking up
the QSL manager's address, fill
out a QSL in the normal
manner, but make sure that
your call Is written on the
report side of the card. QSL
managers don't like to have to
stop and flip a card over to see
who sent rt. That can be very
time-consuming. Next comes
the SASE BASE stands for
self -addressed stamped
envelope and that's exactly
what it is. Address the envelope
in the normal manner,
except address it to yourself
and don't forget to stamp it.
Now, when the QSL manager
fills out your card, he just
drops it into the SASE, seals it,
and mails it back to you. Some
QSL managers like to have the
call of the DX station and the
date and time of the contact
written In the lower left-hand
corner ot the envelope. This
helps them to file your
envelope until the logs arrive
from the DX station. If the QSL
manager is located outside the
United States, skip the postage
stamp and drop a one doUar
bill in the envelope. There are
other ways, such as using IRCs
or foreign postage, but a dollar
bill generally produces the
best results*
If no QSL manager exists for
a particular station, then the
next best route is direct to the
station's home QTH. If the sta-
tion accepts direct QSLs. he
will usually pass you his ad-
dress during the contact. This
is generally a PO box number,
so it is no problem to pass.
Since the OX station receives
many QSL requests, he will
usually return your QSL via the
bureau unless you enclose an
SAE along with the usual dollar
bill. Again, IRCs or foreign mint
stamps can be used, but the
dollar bili produces the best
results. IRCs. which can be
purchased at your local post
office, are too expensive and
are not always accepted in
some countries. One thing can
be said for foreign mint
stamps. Once you stick them
on your SAE, they are useless to
the DX station for any pur-
pose other than to return your
card. One thing must be kept in
mind when considering direct
QSLing. If the DX station says
to QSL via the bureau or via his
QSL manager, there may be a
reason that he doesn't want
cards sent directly to him. In
some countries, the ownership
and use of a radio transmitter
can cause problems with the
I pea I authorities. Receiving
mail addressed to an amateur
radio station from ah over the
world would be a dead give-
away. It's always best to follow
the QSL instructions given by
the DX station. They will usual*
ly produce the best results.
The slowest, but by far the
least expensive, method of
QSLing is via the bureau. In
many cases, such as the Iron
Curtain and Soviet countries,
QSLing via the bureau is the
only way- The best way to QSL
via the bureau, especially if
you have many cards going to
several different countries, is
to ship them all in one bundle
to one of the outgoing QSL
bureaus.
If you belong to the ARRL,
you can send your cards along
with one dollar and the label
from your last issue of QST to
the ARRL Outgoing QSL
Bureau. A shortcoming of the
ARRL bureau is the fact that
they will only forward QSLs to
countries which have an in-
coming QSL bureau. Many
countries have only a few hams
and do not support a
QSL bureau. In fact, ot the 319
^'countries" currently rec-
ognized for DXCC contacts,
the ARRL Outgoing QSL
Bureau will forward cards to
only about ISO. Fortunately,
there are several good com-
mercial QSL forwarding ser-
vices that will forward your
cards anywhere for about Sz
per card, W3KT is one. There
are several others.
In summation, of the three
QSLing methods we have dis-
cussed, the QSL manager is
almost always the best route,
followed by direct QSLing. and
then the bureau. In all cases, it
is best to follow the QSL In-
structions given by the DX sta^
tion himself. Good luck.
Ham Help
I need a manual and/or
schematic for the Multiphase
Exciter Model 20-A made by
Central Electronics, Inc., dur-
ing the 1950s. I will copy, and
return in good condition.
A, McGlnnis WA2DTQ
55 Patton St,
Iselln NJ 0883Q
I am indeed very, very sorry
that I waited this long to thank
you for publishing my letter In
the August Issue.
It seems that when it rains, ft
pours. (I hate to use an old say-
ing.) In August, I suddenly
found that I had some friends,
tor I suddenly received a few
letters and coils, and being par-
tially blind, it took about 2
weeks to discover that my letter
was in the magazine, and then
to find It. In addition to this, I
was studying to get my Novice
ticket, and I can announce that
on September 1, 1978, t became
WDO???
Anyway, I'm also busy set-
ting up my shack and figuring
out the best way to put up my
antenna, and it is creating
some problems- Somehow Til
be able to be on the air when my
license arrives. However,
whenever I get some time, Tve
been slowly trying to get my
telephone together, and with
luck, I should have it working
soon.
So, again I want to thank you,
and all the other people who
have been so kind to me. and
have done so much to help me.
So. thank you, and I'll hear you
all on the air shortly.
Ron Peterson WOO???
Route 1, Box 151
Clear Lake MN 55319
I would be interested in talk*
Ing to anyone who has devel-
oped a simple, chirp-free CW
keying circuit for the Kenwood
TR'7400A so that the trans-
ceiver can be used for 2 meter
OSCAR work,
John Mollan WA7ATU
7005 NE 147th Ave.
Vancouver WA 96662
QSL INFORMATION
A6XP— see text
FK8AH— Robert Gar be, Avia-
tion Civile^ La Tontouta, New
Caledonia
FP8DH— K90TB
FP8YY— K90TB
H5AW— 2S6AW
HZ1BS/8Z4— 0E6EEG
J2©BL~F6BFN
KJ6DL— see text
KM6BI— see text
OJCMA— OH0NA
PWCPP/PYDRO— W1 DA
ST2HF— G4GFI
TJ2P— see text
VGW-211— see text
VK9ZR— VK2BJL
2D7WT— W3KT or via SARL
3B6DA/3B9DA— 3B8DA
3B8Yy— K5YY/K5QHS
3B9ZZ— K4YT
5N2NAS— see text
Thanks to the West Coast
DX Bulletin, Long Island DX
Association, and World Radio
Magazine for much of the
preceding information.
STATEMENT OF OWNERSHIP,
MAHAGEMENT AND aFecyLATlON (1^
quired I?/ 39 U.SC 3686). t. Tltla or
putiHoaltan; 73 Riaga^tne. ^ Oftte ot til-
ing. Oct 1, 197& 3, Fr^ueficy ol fcsiye,
ivrantfily. A. No. at rssye^ publbhod an-
nualty, 12- B. Annual subscription phce.
$15. 4 LQCBtlon Dl Known office Ot
publlcaUon (Strem, Ckty, Counly, B\q\q
and ZIP Code) {Uoi printers!, F'^ne Sireet.
Pelerbortiugh, Hklt9bor<i County, N.-N.
OaiSSt 5. LocflUon of the head^iuarlers
or general "business offrces ol thu
pub4ishef5 (Not ;>riniers]i. Ptne Sireet,
PetertXTrOoQh, H4Jt«bQro County, HM
Oi^S9. 6. Nftmes «f»d compt^ie ad-
dresses 0l p^lisl^tf. ectitor and mansg
ing &Allm. PiO^iBtvBt (ffame and f>^
dresi Wftyrt* Gf t#n . P^tfiftowough. N n
0345& Editor (Name and Addrt*»:^
Vtfa^ne Green. Pet^rttorougri. NMJKWSa
Managing Edilor {HAm& and Addres^K
John Bufnetl. PetffrbofQugh, HM. 03459
7, Ownef {it cwned by & torpor a lion, Its
n^rnp and ^ddr«39 musl ti« statsd and
i3t£o (mm^iataly iheteunder the namei
and acjcfresses of elockholders owning
01 holding \ ptsrcani or more of total
amount o( alock, It not ow^ned by a c.oj-
pumllon, thi names and addre^s^s ol
I he Individual i>4vn«f» inusl be given, II
owned by a pahnerihtp of ottim ufuncat-
porBted fann. its narm and arddrw, aa
«EJF ss ihal ol tiAC^ infSviciyBl mult iw
gjv^^.) Nam«^ 73 Inc.. P«l«rbQrixjQiti. N.K
0345B. Wayna Gf ten» Petddidfiiuih N H
0345i B Known bOfldNoidi&fs. moftgA-
^|e«S, and olh«r sftciiritv l^l^^ef?. owning
Of nodding t percent or more ■eA total
ami04int tft bond$, motigai^es& cv ottmt
'■ies (II m**e are nofv#, so 9l4tt|
nofw. §, For completion by non-
profit organ If at tens aui homed la mail At
special rates (Sec I Jon 132.122, PSM) Thfl
purpose, function, and nonprofit alatuB
of this organisatlan and iti€ exfmpi
status foi Federol Income tax purpoaea
(Ch&ck om) Not applicati^Ee. 10 E^flent
and nature of csrculalion, (J() Av^raga No.
copies «^cfi iS9.ua during preceding 12
months, in Aeluai No. copies of a ingle
issu^ publiftbed n&aresl lo tiling dale
A TotaJ No. DOf>ie& pfinted iHel Preta
RynJOO 77,550 maO^OOO B Pa^d ciiculi-
lloci 1. SalM thdToi^ cteaJers arxj cat-
r ers, street vendors and couintef mJ«»
>i 13.^0 (^\ 14,585. 2. Mai) aubacnp^
t 3n3 m 56,290 (Yt 58,5*7. C Tota* pl*d
circui.ation iSutm of 1081 and 1062) t^)
69,BS0 lY) 72M2 0 Ffws distribuimn by
majl. carrier or other means SHamples.
complimentary, and other freacop^ea (Xl
740 (Y) e^O. i Total dislributkon [Sum of
C and D\ {K\ 7QM2Q [Y) 73,952 F Copifis
not diatrlbulod 1, Qthce use, iefl Cvar,
unaccounted, spoiled ^ft^r prtniina (X}
5,Ei40 (Y) 9,04a. 2. Return from nflwa
agents {X} l,lj&0 (¥) Nona. G. Total (Sum
ol E, F1 and p—nhould equal nat pfeaa
tun stiown m k\ m 77.550 <YJ 90.000
11. t canity that the statement j made tuy
me above ate cotrecl and connpiaie. Skg-
n^ture and 1i1t« of cditDr. pubiisfwr,
bg^Tftess tnanagsr, or umrver, Rooerl R
I^PoVnte, &u6in«ss litoiiflBger.
76
-QUASAR VIDEO
TAPE RECORDER
SALEl
We are constantly testing ham and
other electronic equipment for review In
73 Magazine. Jn order to be abie to i<eep
tills not inexpensive project going we
have to sell off the equipment used for
test. Most of It has been used for a few
days and Is In every way as good as new
In many cases it is better than new since
95% of the equipment failures come
within the first few hours of OF>eration.
In this case we are running a series
of lests of VTR systems, usmg them for
regular, ham TV. SSTV, and even micro-
computer programming tests. One of the
best we've found so far Is the Quasar sys-
tem, but we still have to go on and test
the RCA. |VC. and many other systems
... so our Quasar is up for sale. We paid
well over S I ♦OOO for the Quasar . , . used
It for a few days and have gone on to test
more systems.
Quasar VTR
System . . . .
. special Uke new $675.
Peterborough NH 03458
Major Credit Ords Accepted.
FT-227
MiEMORIZER"
OWNERS: SCANNER KIT
•SckttlUt t«tt« wtm (pp t9 fait b4«d]
#kMS *mhj fe p«rri«fl si Imii ^h ^tkd
•Sob iI it till fl 200 kill per vtwd
V bd M. Mf 9(CmKi llMMJLT
• tn5talli in\iili rig no dtfvUie ei^mil cwwrtiepil
• Si^ [in liirfi bi returaMl IQ ofiginiJ tondilion
wbeiitrer dtiired
• Scans k peeieF limits dud feifcri«i
• Anloinjlic him^ vl totJcid Ffequen^T in Va mmii
unk» fw prti^ lodt-sn iiildi
IC22S SCANNERS ALSO AVAILABLE
KITS34,95;
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[add S1.50 postage & handling]
DEALER ISQUlRiES INVITED
ELECTRONICS
/bO LUCtRtNt ro. SUITE 120
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PROVIDBS STRONG, PRECISE
MARKERS EVERY 1 MHz,
500, 250, 100, 50, 25, l6, 5,
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f»if
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8.5 V tQ IS V at IS ma.
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D Q V E T R G
III
MPC-1
MultJpath Correction
In -Band Diversity &
AFSK Tone Keyer
Amateur Net: $545,00
standard features include CONTINUOUSLY tuneable Mark and Space chaonels (1000
Hz to 3200 Hz), Dual Mode (MARK or FSK) Autostart and internal high level neutraf
loop keyer (20 to 60 ml). Both El A and MIL FSK outputs are provided for direct
interface to microprocessor and video terminal peripherals.
MPC-IOOOCR
Signal Regeneration &
Speed Conversion
Amateur Net: $645.00
A front panel switch permits internal TSR'200 Signal RegeneratorSpeed convert-
er assembly to electronically "gearshitt" between 60. 67, 75 and 100 WPM. All
incoming and outgoing signals are regenerated to less than 0.5% bias distortion.
Also avarlable wrth DIGITAL Autostart (TSR 200D): Amateur Net: $695.00
MPC-IOOOR/.
TSR-500
Dual UART Regeneration,
Speed Conversion, 200
Char, Memory, Word Cor-
rection S DIGITAL
Autostart
Amateur Net: $895.00^
The MFC 1000 RASR 500 provides Preloading and Recirculation of the 200 character
FIFO Memory, a keyboard control led Word Correctfon circuit, Variable Character
Rate, Tee Dee Inhibit, Slank/LTRS Diddle, a Triple Tone-Pair AFSK Tone Keyer and a
Character Recognition/Speed Determination DIGITAL (DAS- 100) Autostart mode.
*The MPC-IOOOR is also available without a TSR assembly and functions as a MPC-
lOOOC with a Triple Tone-Pair AFSK Tone Keyer. This "Basic-R" permits future ex-
pansion with a TSR-lOO, TSR'200, TSR-200D or TSR-500 by simply liftrng the lid
and pluggmg in the appropriate TSR assembly: Amateur Net (Basrc-R): $595.00
Your QSL will bring complete specifications, or calf: 213-682-3705.
►^023
627 FREMONT AVENUE
(P. O. BOX 267)
SOUTH PASADENA, CA. 91030
%^ Readef Service — see page 323.
71
JUST GETTING ON THE AIR?
See Adirondack for
T
D New Equipment
D Used Gear
D Friendly Advice
185-191 West Main Street • PO Box 88
Amsterdam. N Y 12010 Tei (518) 842-83S0
Just 5 minutes from NY. Thruway— Exit 27
The ST-5000 from HAL
The HAL ST-5000 sets the pace for an economical
deinodulator/keyer for radio-tetetype (RTTY)* All the fea-
tures you need for reception and transmission of HF and
VHF RTTY are here,
TTie demodulator features a hard-ilmitins front end,
active lUter discrbninator, and active detector circuitry for
wide dynamic range. Autostart and motor control circtiitry
make for easy VHF and HF autostart operation.
Convenient front panel switches are provided for 850
and 170 Hz shift, normal or reverse sen$e» autostart on^off ,
print - line or local, and power on,/ off. 425 Hz press
tiansmissions may also be copied with the ST-5000. High
voltage 60 ma, loop output as well as low level RS-232
compatible output are provided by the demodulator*
The audio keyer section of the ST^OOO generates
stable, phase-coherent audio tones. Transmission is a
simple matter of applying these tones to your HF SSB or
VHF FM transmitter.
The ST-5000 is housed in an attractive blue and beige
cabinet and is backed by the HAL Communications one
year warranty.
For complete specs on the HAL ST-50W, write or call
HAL today. $275.00
HAL Communications Corp., Box 365, 807 E. Green St.
Urbana. BUnois 61801 • Telephone (217) 367-7373
I
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Models available for all Ham
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CALL OR WRITE FOR DETAILS:
WACOM PRODUCTSJNC
Box 7307
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The ONLY thing you
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73Q1B
78
(^ Reader Seme^see page 323.
Swan SWR-3 $14.50
Swan SWR HFM-200 44.95
Swan SWR WMM-200 44.95
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ELECTRONICS, INC
1106 RAND BLDGv
^Tia hRAC buffalo NY 14203
K
EY
1^ Header Service— see page 323.
79
Ham Help
) woufd like to provide a little
feedback In regard to my re*
quest (May, 1978) for informa-
tion on the 8326 tube and the
Halltcrafters SR500, 1 found out
that 8326s are available from
CeCo for $22 each. They are
rated at 50- Watt plate dissipa-
tion. A direct replacement is
the 6DQ5; however, it has only a
24-Watt plate dissipation, so be
real careful on tune-ups. The
6146B was not recommended
as a replacement I got 28
replies plus one phone call on
thai one. My second request
was about a K-W crystal and I
Study Guides
and
Code Tapes ~
The Best Available
itmpai/it 3tS
got 11 replies telling me that
K-W Manufactufing. PO Box
508, Prague OK 74864, made
the crystal. When I sent them
the bad crystal, they sent me a
nBw one at no charge! Ham
Help realiy works! Thanks.
Marvin Moss W4UXJ
Atlanta GA
I've got the kind of problem
that will require the help of real
hams. I have only held my
Novice license a short time,
and, so far, I have only been
able to acquire a few books,
magazine articles, etc. I have
not yet been able to meet any of
the tocai hams, and my per-
sonal knowledge level and
technical resources are still
very limited. But, nevertheless,
I am determined to help a friend
who is blind enter the exciting
world of ham radio.
I would very much appreciate
hearing from anyone who may
have ideas or information on
operating aids, and any advice
at ail on methods or procedures
of teaching the blind. Thank
you.
Jack Beckwith WB7VBC
624 W, Linden
Caidwell ID 83605
I am writing in the hope that
someone might be able to give
me some advice or possibly
direct me to someone that
might be of assistance. My wife
and I are going to Cayman
Brae, Cayman Islands, in
January. The purpose of the trip
is a diving vacation with under*
water photography. Anyway,
the other night I got the bright
idea to take along a radio, A day
or two fater, I sent off a request
for a license. Now comes the
problem — weight? We are
allowed a mere 47 tbs. With div-
ing and photography equip-
ment I'm afraid the toothbrush
will have to be a lightweight
one! Does anyone know of an
operation on Brae ? Or, can
anyone come up with a solu-
tion . . . short of not taking my
wife's diving equipment.
Thanks for the help.
John Aubrey W5EQ
1113 N. 58th Terr.
Fort Smith AR 72904
[ am building a receiver, and I
need a subminiature audio
transformer, such as those
found in small transistor
radios, with a 10,000-Ohm
primary and a I^OOO-Ohm
secondary. Also, I must obtain
a speclai item from a store In
Regina. Saskatchewan. 1 would
greatly appreciate hearing from
any Canadian ham who could
be of assistance in obtaining it.
Paul Hoegstrom WOaOTW
$962 S. Park Blvd.
Parma OH 44134
[ need information to con-
vert 3 Motorola MtCOR
T53RTN1190A to ham and/or
MARS 2 meter frequencies. I
also need data on the SC-946
handset. Thanks.
Frank Noliette KAiAOJ
522S Clark
RlchardS'Gebaur AFB MO
64030
I need a schematic diagram
and service manuals for an
Icom DV-21 digital vfo, a Ka-
tional NFS receiver, an
Amplldyne Labs model C14
220-MHz converter, and a Cen-
timeg 432-MHz converter,
Jung Y. Lem KB6B0
S222 Coringa Dr.
Los Angeles CA 90042
I need help. I bought a
Mustek integrated tone
receiver chip, #MK5102(nl-6,
but I can't get it to do anything
but look back at me from my
table. I need help specifically
for the input and output cir-
cuits.
Morman E. Rosenspan
64 Berry Avenue
Staten Island NY 10312
An ancient amsieur pwveib lias it that- "11 fou can't hear Ihem. ym can't
wntk them ''
Ttiars one rtason wtiy our linearized anip^ifief /pieamplifier combinaiiDns art the
fastest s^knq ^^g& in The amatiw radio ma/Vet Hot vtnhi dt they provide you with
9 itB jahnost 2 S ' umts) of incn^eri signal at ttta other guys rtcetver; but, they
a 1^0 prtivide you with a greatly improved capability i^ rtad his sipal. Our trans-
milting arrp/preamp combos don't just give mora output powef; they abo provide
you with the iRCf«as«it sensitivity you need to makt those contacts that you've fiever
mide tetort ftemembet. Ite Other guy may not have a Lunar ampvp/f amp yet Our
bitter than 2 dB noise f igif e irKlicates thai Lunar Has achieved the practical limit at
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lignais olf the moon or ir^ng to pcb up a noi^y signaJ in your car. Uinsr s preamp m
our bt-lineir amplifier is the best hearing ant ' iw can havt.
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Accepts all modes Power ranges from 50 to 250
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From itSd 95
RECEIVING PREAMPS
For the most demanding needs where lew noise
figure h importai^t Medium and high ga<n models
now ava]ai}le fm trequenciis 2B to 45€ MHl
From S34.95
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WISNMT
80
Ip"^ R&ader Service — see pag^ 32X
Social Ei/ents
HAZEL PARK Ml
DECS
The Hazel Park Amateur
Radio Club will hold its 13th an-
nual Swap & Shop on Sunday,
December 3, 1976, from 9:00 am
to 3:00 pm, at Hazel Park High
School, Hazel Park, Michigan.
Prizes roclode a TS-520S. HW*
2036A with MIcoderT''^, and a
Bird Model 43 wattmeter with
element. Admission is $1.00.
There will be food, door prizes,
and free parking. Reserved
talkie space is 75^ per foot.
Talk-in on 146.52. For delails,
send an SASE to Robert
Numerick WB8ZPN, 23737
Couzens, Hazet Park Ml 4B030.
SOUTH BEND IN
JAN 7
The Repeater Valley Hamfest
Swap & Shop will be held on
Sunday, January 7. 1979, at the
New Century Center on US 31 in
South Bend, Indiana. This
event will be held indoors with
food service available. An
automobile museum and art
center are in the same building.
Tables are $3.00. Talk-in on
146,1 3/.73, .34/.94, and .52/.52;
147.99/.39, .93/.33, .84/.24, and
.69/,09. For information, con-
tact Wayne Werts K9IXU, 1889
Riverside Drive, South Bend IN
46616; (21 9)-233-5307.
RICHMOND VA
JAN 14
The Richmond AmateurTele-
communications Society will
hold its Frostfest-ll on January
14, 1979. at the Bon Air Com-
munity Center In Richmond,
Virginia. Talk-in on ,28^88,
.34/.94, and .52. There will be a
technical symposium, a draw-
ing, and a home-brewers' con-
test with two divisions, over IS
and under. FCC exams will be
administered starting at 10:00
am. To take the exam, mail
Form 610 at least five days prior
to the Fest to the address
below. Commercial exhibitors
are by invitation only. There will
be an indoor flea market wfth
one table for $2.50 and outdoor
tailgate space for $1.00. Admis-
sion is $2.50. For information,
contact the Richmond Amateur
Telecommunications Society^
PO Box 1070, Richmond VA
23208.
SOUTH FIELD Ml
JAN 21
The Southfield High School
Amateur Radio Club will hold
its 14th annual Swap & Shop on
Sunday, January 21, 1979. at
Southfield High School, South-
'ieid, Michigan, at 10 Mile and
_asher. Admission is SZOO. For
nformation, send an SASE to
Robert Younkers, 24675 Lasher
Rd., Southfield Ml 48034, or call
{313)-354-8210.
MfAMi FL
JAN 27-23
The Dade Radio Club
presents the 19th annual
Tropical Hamboree and ARRL
South Florida Convention on
January 27-28. 1979, in Miami.
Florida. Over one hundred ex-
hibitor booths, a giant flea
market, and several technical
and group sessions will
operate simultaneously In com-
pletely separate areas of the
Flagler Dog Track Auditorium
building. With the Convention
immediately following the
Miami Board Meeting, most
Division Directors and HQ of-
ficials will be present for the
ARRL general session. Exten-
sive free parking, including
overnight space for RVs, is
available on the grounds. Pre-
registration is S3.00; $4.00 at
the door. For up-to-date infor-
mation, booth space, flea
market table space, RV parking
space reservations, and hotel
rates, write DRC Hamboree. PC
Box 350045, Riverside, Miami
FL 33135.
MANSFIELD OH
FEB 11
The Mansfield midwmter
hamfest/auction will be held on
February 11. 1979, In a heated
building at the Richland County
Fairgrounds in Mansffeld,
Ohio. There will be prizes and a
flea market- Doors will open to
the public at 8:00 am. Talk-in on
146.34^.94. Advance tickets are
$1.50; $2.00 at the door. For in-
formation, contact Harry Friet-
chen K8HF, 120 Homewood,
Mansfield OH 44906, or phone
(419)-529-2801 or(4l9)-524-1441.
LANCASTER PA
FEB 18
The 7th annual Lancaster
hamfest will be held on Sun-
day, February 18, 1979, at the
Guernsey Sales Pavilion, US
Rt. 30 & PA Rt. 896, Lancaster,
Pennsylvania, Doors will open
at 8:00 am and there will be a
prize drawing at 2:00 pm. Ad-
mission is $3.00, and table
reservations are S2.00 in ad-
vance. There is a new, larger in-
door flea market area. Food
and soft drinks will be
available. Talk-in on 146.01/,61.
For further information, con-
tact SERCOM, PO Box 6082.
Rohrerstown PA 17603.
DAVENPORT I A
FEB 25
The Davenport Radio Ama-
teur Club will hold its hamfest
on February 25, 1979, at the
Masonic Temple in Davenport,
Iowa. Admission is $2.00 in ad-
vance, $2,50 at the door. Re-
freshments and tables will be
availabfe, TaJk-in on .287.88 and
.52. For further information,
send an SASE to John S. Birm-
ingham WB0QCC, 2022 Brown
Street, Davenport I A 52804.
LIVONIA Ml
FEB 25
The Livonia Amateur Radio
Club would like to announce
that the 9th annual LARC Swap
'n Shop will be held on Sunday,
February 25, 1979, from 8:00 am
to 4:00 pm, at the new location
of Churchill High School in
Livonia ML Tables, door prizes,
refreshments, and free parking
will be available. Talk-in on
146,52 simplex. Reserved table
space of 12-foot minimum is
available. For further informa-
tion, send an SASE to Neil Cof-
fin WA8GWL. c/o Livonia
Amateur Radio Club, PO Box
2111, Livonia Ml 48151,
VERO BEACH FL
MAR 17-18
The Treasure Coast Hamfest
will be held on March 17-18,
1979, at the Vero Beach Com-
munity Center, Vero Beach,
Florida. Activities will include
prizes, drawings, and a OCWA
luncheon. Admission is $3.00
per family. Talk-in on 146.13/
.73, 146.52/.52, and 222.34/
223.94. For information, write
PO Box 3068, Vero Beach FL
32960.
WAUKEGAN IL
MAR 25
The Lfbertyville and Munde-
lein Amateur Radio Society will
hold its second annual Lamars-
fest on Sunday, March 26, 1979,
at the J. M. Club, 708 Green^
wood Ave., Waukegan, Illinois.
Doors will open at 7:00 am.
There will be plenty of free park-
ing, door prizes, and a large in-
door flea market for radio and
electronic items. Tables will be
available at $4.00 each. Ad-
vance tickets are $1.50; $2.00 at
the gate, with children under tO
free. Hot lunch will be available
and Ihere will t>e plenty of com-
mercial exhibits and demon*
strations. Talk-in on 146.94. For
further information, write
LAMARS {include SASE,
pleasej at 1226 Deer Trail Lane,
Libertyville IL 60048, or call
(312^387-1599.
MUSKEGON Ml
MAR 30-31
TTie Muskegon Area Amateur
Radio Council is sponsoring
the ARRL Great Lakes Division
Convention and Hamfest at the
Muskegon Community College
in Muskegon, Michigan, on
March 30-31. 1979. This event
will feature manufacturers' ex-
hibits, technical forums, and a
large swap shop. Ample park-
ing and dining facilities are
available. Friday evening at the
Muskegon Ramada Inn, there
will be a "Ham Hospitality"
with libation courtesy of the
MAARC and a Wouf Hong ini-
tiation. For additional informa-
tion, contact MAARC, PC Box
691, Muskegon Ml 49443, or H,
Riekels WA8GVK; (616)-722-
1378/9.
NATCHEZ MS
APR1
The Old Natchez ARC
Hamfest will be held on Sun-
day, April 1, 1979, at the
Natchez Convention Center,
Natchez, Mississippi. The
event will be indoors and air-
conditioned. There will be free
admission and swap tables.
Talk-in on 146.31/. 91 and
146.52. For information, write
ON ARC, 1226 Magnolia Ave^
nue, Natchez MS 39120.
UPPER HUTT NZ
JUNE 1-4
The 1979 Annual Conference
of the New Zealand Associa-
tion of Radio Transmitters will
be held on June 1-4, 1979, at
Upper Hutt, New Zealand.
Visitors are welcome to attend
this conference. For registra-
tion forms, contact the
Secretary, 1979 Conference
Committee, PO Box 40-212, Up-
per Hutt NZ.
LOUISVILLE KY
JUN 29 JUL 1
The Louisville Area Com-
puter Club will hold its 4th an-
nual ComputerfestTM igjg on
June 29 through July 1, 1979, at
the Bluegrass Convention
Center, Louisville, Kentucky,
Activities include a flea market,
seminars, and exposition, as
well as activities for the entire
family. Seminar and exposition
admission is $4.00. Pre-reg-
istered Ramada Inn guests
($29.00, single; $34.00, double)
receive free admission. For ad-
vance mail information, write
Computerfest '79. Louisville
Area Computer Club. PO Box
70355, Louisville KY 40270. or
phone Tom Eubank, Chairman,
at(502f-895-1230.
81
SSTV Recorder Controller
replaces your index finger
C. A. KoHar K3JML
1202 Gemini Si.
Nanticoke PA IS6S4
This article describes a
device which will make
the recording of a picture
from a scan converter or
SSTV camera more conve-
nient. At present, using the
Robot 400 scan converter,
the procedure 1 use gen-
erally goes tike this: The
closed circuit TV camera is
adjusted for proper focus
and picture content. A
frame is then snatched by
the 400 and entered into its
memory according to in-
structions in the manual.
Once entered into the
memory, the picture can
be recorded for future
playback by putting ''trans-
mit select" in "memory"
TO
'HE MOTE'
JACiC
SSTV t»i >
SSTV TO
BECOHtJER
Fig. "I. SSTV tape recorder synchronizer. Q1 —any general-purpose PNP silicon transistor; Q2 — any general-purpose
NPN silicon transistor.
82
and recording the resulting
SSTV signal from the audio
cable plugged into the ''to
tape'' jack on the back of
the 400.
This is where the tape
recorder comes into play.
Up to now, the procedure I
followed was to watch the
FSTV monitor for a bl ink in-
dicating the end of one
frame and the beginning of
another. At this point, I
would count seven sec-
onds [a complete frame
takes about eight seconds)
and engage the tape re-
corder. This ensured that
the 1200 Hz reset pulse at
the end of the frame would
be captured on tape to en-
sure proper vertical sync
for the next complete
frame. I then would watch
very closely for three more
winks, indicating that three
complete frames had been
recorded. After the third
wink, the tape recorder
would be disengaged.
Three frames is the usual
amount sent by SSTVers to
try to ensure copy of the
video through QRM. The
disadvantage to this sys-
tem is the necessity of
watching for a wink, count-
ing seven, engaging the
tape recorder, counting
three more winks (4 in-
cluding the one imme-
diately after engaging the
tape recorder), and then
disengaging the tape
recorder. A momentary
distraction can result in
missing the sync pulse and
starting in the middle of a
frame or recording more or
less than three frames.
^^^^
o o o o o o
E 2 ui tJ — cy
^ 4t S ^
^ * - «
e o 1 © ©
Fig. 2. Suggested
panel layout
front
With an SSTV camera,
lighting and focus are first
set up as usual. Then you
must wait until the scan
gets near the bottom of the
frame, at which time you
engage the tape recorder.
Next, you must observe
three complete frames and
then stop the tape record-
er. As with the 400, en-
gaging the tape recorder
when the scan is near the
bottom ensures that the
sync pulse for the first
frame you will record wil
also be captured on tape.
Enter the SSTV tape
recorder synchronizer.
With this device, all you do
is enter the picture into the
400 memory, set the trans-
mit selector on the 400 to
"memory," press the
''arm" button on the syn-
chronizer, and go about
your business. The syn-
chronizer will turn on your
tape recorder at the proper
time to capture the initial
sync pulse, record three
complete frames, and shut
off automatically. There's
no need to get cross-eyed
watching for winks on your
fast-scan monitor. With an
SSTV camera, hit the arm
button as soon as focus
and lighting are set up, and
the synchronizer will do
the rest — no more count-
ing frames.
Circuit Description
Initially, the circuit is fn
a standby condition where
pin three of the 7400 (see
Fig. 1) is low. This turns off
< ^
rc;i
**. .^^
11^0^
PWR
ARM
D G
SSTV
TAPE RECORDER
SYNCHRON I ZER;
K3 JML
Front panel layout of the prototype.
83
Enclosure opened to reveal the perfboard construction and parts layout.
Q2, de-energizing the relay.
It also grounds pins 10 and
13 of U4, resetting the flip-
flops to zero. The R-S flip-
flop consisting of U3C and
U3D is in the state where
pin 11 (Q output) is low.
This grounds pin 4 of the
555, disabling it. This initial
state is ensured by Q3,
which momentarily grounds
pin 9 of USD when power is
applied. The circuit is set
into operation by depress-
ing the arm push-button,
which now makes U3C, pin
13 low, which causes pinll
of U3C as well as pin 4 of
the 555 to go high, enabling
the timer and lighting the
arm LED.
SSTV audio is fed to pin
3 of the 567 decoder
through a .1 uF capacitor.
The output of the decoder
(pin 8) is normally high and
goes tow whenever a 1200
Hz reset pulse is detected.
This turns on Q1, bringing
pin 2 of the 555, pin 12 of
the 74107, and the positive
end of the 1 00 uF capacitor
to ground. The 100 uF
capacitor is necessary to
prevent the 74107 from
counting more than once,
because of glitches, during
the duration of the reset
pulse. When pin 2 of the
555 goes low momentarily,
its output (pin 8) goes high,
lighting the LED for a time
determined by the 1 meg
pot and 10 uF capacitor
connected to pins 6 and 7.
In this case, it is set up for
seven seconds. At the end
of seven seconds, pin 3
goes low, pulling the end of
the 500 pF capacitor to
ground, which in turn pulls
pin 1 of U3A to ground
momentarily. This sets the
R-S flip-flop U3A/U3B,
making pin 3 high. This
high turns on Q2, pulling in
the relay which turns on
your tape recorder. It also
makes pins 1 0 and 1 3 of the
74107 high, enabling the
dual j-K flip-flop, U4,
U4 will now count the
next four reset pulses (the
initial reset pulse and also
the next three indicating
three complete frames)
supplied by the 567 de-
coder whenever it sees
1200 Hz. On the fourth re-
set pulse, indicating the
end of the third complete
frame, U4B, pin 5 goes low,
bringing one end of the .1
uF capacitor connected to
it to ground. This in turn ap-
plies a momentary ground
to pin 5 of U3B, resetting
the flip-flop, and pin 3 goes
low. When pin 3 goes low,
Q2 stops conducting, and
the relay drops out, stop-
ping the tape recorder. Pin
3 of U3A also pulls pins 10
and 13 of U4 to ground,
resetting the flip-flops to
zero and disabling them.
At the same time, pin 3 of
U3 A pulls one end of the .1
uF capacitor connected to
pin 9 of U3D to ground,
thereby applying a momen-
tary ground to pin 9, reset-
ting the flip-flop U3C/U3D.
Pin n of U3C goes low and
disables the 555 timer.
The LEDs, placed as they
are, give an indication of
proper circuit operation
for maintenance and oper-
ation of this unit. One set
of contacts on K1 removes
SSTV audio from the tape
recorder when its remote
input becomes disengaged
by the synchronizer so as
not to record anything dur-
ing the time the recorder is
coming to a stop.
Initial Setup
There are only two ad-
justments to be made to
place the synchronizer into
operation ^the 1200 Hz
decoder and the 555 timer.
The 1200 Hz decoder can
be set up in one of two
ways, Method #1 is to con-
nect a frequency counter
with a high-impedance in-
put between pin 5 and
ground and adjust the 10k
pot connected to pin 6 of
the 567 for 1200 Hz. Meth-
od #2 is accomplished by
connecting a VOM, VTVM,
or scope to pin 8 of 567.
While applying an accu-
rate 1200 Hz, adiust the
pot mentioned above until
you see the meter drop
suddenly to zero. You will
notice a small amount of
play in the rotation of the
pot between the points
where the voltage is zero
and where it is 5 volts. The
pot should be set at the
middle of this range. The
555 timer is set up by
observing the LED con-
nected to pin 3 of the 555.
Disconnect the 500 pF
capacitor connected to pin
3, press the arm button,
and the arm LED should
light. Momentarily short
pin 2 of the 555 to ground;
the time LED should light
for a period of time and
then go out. Adjust the 1
meg pot connected to pin 6
of the 555 so that the light
stays lit for 7 seconds.
Reconnect the 500 pF
capacitor. Initial adjust-
ment is now cornplete.
Operation
Connect the output of
your SSTV camera to
"SSTV in" on the syn-
84
chronizer, or; if using the
Robot 4O0, insert a picture
into the memory of your
scan converter. Connect
the output of the scan con-
verter to "SSTV in" on the
synchronizer. Connect
"SSTV to recorder" to the
auxiliary input on your
tape recorder. Connect "to
recorder remote" to your
recorder remote jack. Your
recorder motor functions
should be normal (SI off).
Pul SI on, and note that the
power LED lights. Put your
recorder into the record
mode; your recorder
motors should not operate.
Depress the arm push-but*
ton; the arm LED should
lighL The very next 1200
Hz reset pulse that arrives
should light the time LED.
After 7 seconds, the time
LED goes out momentarily,
the record LED should
light, the relay should pull
in, and your recorder
should start. In sequence,
on arrival of the 1200 Hz
Close-up of the per f board and core wiring.
Fig. 3. PC board.
as
Fig. 4. Component layout
sync pulses, the "1" LED,
the ^'2" LED. and both the
^'1" and "2" LEDs should
light. Eight seconds after
the "1" and "2" LEDs light,
all LEDs except the power
LED should go out, and the
recorder will stop.
Comments
Fig. 2 is the suggested
panel layout for the syn-
chronizer. Parts layout is
not critical as long as good
wiring practice is followed.
All parts are off-the-shelf
items available at most
electronic stores. The .068
capacitor connected to pin
6 of the 5676 decoder
should be a good quality
mylar to avoid problems
with the decoder drifting
off frequency.
Please note that the
photos of the synchronizer
are of the prototype, in
which perfboard was used
to build the circuit. The cir-
cuit may be built in this
fashion, or the full-scale PC
layout shown in Fig. 3 may
be used instead. If the PC
layout is used, a suitable
housing will have to be
chosen to accommodate it.
My sincere thanks and
appreciation go to Joe
W7SI for the photos and to
Stan K3ETN for the PC
layout. Questions regard-
ing this project will gladly
be answered when an SASE
is included. ■
86
1
^ ULTRA TUNER
ULTPA TUNER DELUXE
The new SST TA Ultra Tuner Deluxe
matches any antenna-^coax fed or
random wire on all bands (160-10
meters). Use it with your dipole, vertical,
beam, etc. It works with any transceiver.
Tune out the SWR on your antenna for
more efficient operation of your rig. One
antenna can even be used for all
bands. The SWR on mobile whips can
be tuned out from inside your car.
An easy-to-read two color meter scale
provides convenient indication of SWR
for easy tuning. A back panel antenna
switch allows you to select between two
coax fed antennas, a random wire, or
tuner bypass.
The SST T-4 Ultra Tuner Deluxe is com-
patible with any rig— solid state or tube,
Ifs compact size {T x Zl/T x 5")
makes it ideal for mobile, portable, or
home operation. Features an attractive
bronze finished enclosure and exclusive
SST styling.
Features:
• Matches any antenna - coax fed or
random wire. L8-30 MHz.
• 300 watt output power capability,
• SWR meter.
• Antenna switch on back panel.
• Efficient tapped inductor.
• 208 pL lOOOv, capacitors for flexible,
reliable operation.
• Johnson binding posts. Four S0239
connectors,
• Made in USA.
Compare features, quality, and price—
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87
SWR
Power Meters
COMBINATION^
SWR IlIiLD
STRENGTH METER
Mcjisurcs SWR up to
3:1, m hi^xcr. Meter
hafi itcnsilive move-
mem and eaftv-rtrudlng
UV(>-c*jUir scale. 5%
at-'uiirmjY, 52 ohmH
impcduncfc:. Sf)-239
fL'mule coaxiul coji-
ncciun^. 6" higli n 2"
\ndc X 2^" deep.
Mt«klS\VK'A8l4*95
MINI SWK METER
Small siitc makes ihis
the perfect mobile or
jKjriiit>le meter. Sensi-
tive meter with cuhv-
i o- re u d l w n - e ci 1 o r
scal<;. Mctai cane
1 -D ; y X *- I 1 O X
0-1/8". Mockl SWR li
POWER/ SWR /F.H. METER
Measures SWK and [Mnvcr (in 0-10
and Q*100 wati ntn^en. GnrMi up
lo 225 Ml Iz for SWR funciion, up
to 14K MH? for jM^wer funeiifmH.
Aeeurui,^': 5% on SWR, 10% on
[n>wcr ftmetums. 2" ?t 4^*" s 2W
Model swR-(^ gm,m
DUAL METER SWR BRIDGE
Shows iintput i)€iwer aiid reflected
(lower simullaueimsly. Can \n:
used as reference prmcr meter,
ItHK Wide seale, casy-lo-reud
meter \'ixixs. Huui uieicrs make
anlcnnu inncratliiisiiiieiitsa snap.
Good through 175 MHz. May he
kft in-Utic up to 2.000 wails.
Mmii 1 SWR-n i*a9.95
POWER SUPPLY
Laliiiriiiory grade 12V 10 amps
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Otii|uiT regulation: -02 ^Si. Ripple :
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(ccicd. 16 lbs. 0-71 *C. Special
purchase at fniclltm of rei^nlar
price. Additionul jnformaikm on
requesi . M*idel I*S 1 $194, 00
SST T-1
RANDOM WIRE
ANTENNA TUNER
ONLY
^29.95
All band opcrntKm (160-10 meters) with any
random length of wire. 200 watt output
power capability — will work wiili virtually any
trunf»cci%cr. hlcal for pi>rtablc or home
operation. Great for apartincrtts atid hotel
rooms— simply run a wire Inside, out a
window, or anyplace available. Efnctcnt
toroid in(htctor for stnall ^i7Xi 4-1/4" r
2-3/8" » Jr. and nc|^lit^lblc loss. Built-in
neon tune-u|> indicalor. SO-239 connector.
At tractive bnmze finished cnclosnrc.
The Orit^iuii! Random Wire Antenna Tuner
In use bv amateurs for 7 years.
SST T-3 MOBILE IMPEDANCE
TRANSFORMER
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^19.95
j\latchcs52 <>hni coax to the lower impedance
of a mobile whip or vcrtlcaL l2-po*iition
switch wltli tapfi spread between 3 and 50
ohms, llroudbarid from 1-30 MHz. Will work
with virtually any transceiver— 3i(M} watt out-
pui power capabiiily. St)-209 connectors.
Toroid inductor for stnall size: 2-3/4'
» 2-1 /4'* . Attractive brouicc finish.
^WBonRi
t.trt?
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K 2
SST A-1 VHF AMPLIFIER KIT ONLY
^29.95
H49.95 wired
*irtd tested.
S5T-*i
IB"
1 watt inpni gives yoti 15 watts vnitput across
the entire 2 meter Imnd withoni re*tuning.
This casy-to-build kit (appro^. V^ hr. assem-
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plete amplii*ler. All tofi f|uailt\' components,
fcunpaiible wMb all 1-J3 watt 3-ineicr trans-
ceivers* Short an*l ojien ]iroicctcil— not
damaged by high SWR.
Kii inehides:
• Hichcd and drilled G-IO ct*i*xy solder
plated board.
• Heat sink and mounting hardware. Ail
Components— Incluflln^ pre-wonnd coils.
Less case.
• Top cpiulity TRW RF pi I we r transistor*
• Complete usscmhly InslrucMonH wUh
details on a carrier ojicraled T/R swilch.
(f'OR switch parts 810 ppd.>.
i^SlO
P.O. BOX 1 LAWNDALE. CALIF,
9D260C213] 373-5637
86
□
ULTRA TUNER
ONLY
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THE STAIlfDARD TU^fER"
'llic SST T-3 Ultra Tuner has become the stantlard timer the
world over. The original SST concept of offering compact
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tW;
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■'^*«*****!iSti»,^.
CHECK
THESE FEATURES:
Tunes out SWR on atiy coas fed antenna us
well as random wires. Works great on all
bands (80*10 meters) w^ith any transceiver
running up to 800 watts power output.
Increases usable bandwidth of any antenna.
Tunes out SWR on mobile whips from
inside you rear.
Uses efficient foroid inductor and specially
made capacitors for small size: SV*" ^ 2H"
x8H"- Rugged, yet compact. Negligible
line loss. Attractive bronze finished
enclosure. SO-S139 coax connectors are used
for transmitter input and coax fed
antennas. Convenient binding posts arc
provided for random wire and ground
connections.
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89
Receiver Diseases
and how to cure them
Joseph J. Carr K4IFV
5440 South 8th Road
ArHngmn VA 22204
Two identical transceiv*
ers need repairs. One is
completely dead — no
sound, no lights, nothing
works. The other works
weil, except that, on
receive, a static-like
''frying-eggs*' sound is
heard occasionally, and it
is capable of drowning out
all but S9+ signals. Which
of these will be the hardest
to troubleshoot?
Many inexperienced
troubleshooters pick the
Photo A, Freon cool spray (available at most electronic whotesalers) will cool off the circuit and help locale bad com-
ponents.
90
dead receiver/transceiver,
probably because the
symptoms hint at some cat-
astrophic failure. Dead re-
ceivers, whether the dial
lights come on or not, are
usually relatively easy to
troubleshoot. Even if
smoke has rolled out of the
innards (some say especial-
ly), the problem of locating
the faulty part(s} is actually
pretty easy.
It IS the more subtle
problems that tend to snap
your mind clean out of its
socket! The static, pops,
hisses, and miscellaneous
oscillations and grum-
blings that a defective re-
ceiver is capable of gener-
ating are often rather dif-
ficult to pin down, espe-
cially in a short period of
time. The professional ser-
vicer who hears a customer
making such a complaint
will often as not utter a
silent "Oh, no!" and say a
private prayer because he
knows that such problems
can take a lot of time, and
there is a limit to how
much of a labor fee the
market will bear.
In this article, I will ex*
amine some of the causes
of noises and the trouble-
shooting techniques ap-
propriate to each by taking
you through several case
histories. These troubles
have occurred in amateur,
CB, and commercial com-
munications receivers,
plus a few million times in
consumer equipment, so
they are all but universal.
Case No* 1
A High-pitched Whistle
Some years ago, I had to
service a vacuum-tube re-
ceiver that had a high-
pitched whistle superim-
posed on the audio output.
In receivers, this could be
caused by any number of
devilish faults, but, in this
case, it was relatively easy
to pin down the section of
the receiver at fault be-
zause the noise did not go
jway when the audio gain
:ontrol was set to mini-
mum, tf anything, the ap-
parent amplitude went up
because of an improved
signal-tcnnoise ratio.
The trouble in this case
turned out to be in the
power supply powering the
audio preamplifier stages.
A panel-mounted neon
lamp (Fig. 1) was used as
the power-on indicator,
and this lamp was connect-
ed into the dc power sup*
ply, rather than in series
with a 150k-Ohm resistor
across the ac line as is nor-
mally done. The circuit
designer apparently tried
to gain a little dc voltage
regulation with the lamp,
forcing it to serve a dual
function, thereby saving
money.
The circuit (Figl) con-
tained series resistances R1
and R2 to drop the voltage
to the level required by the
neon bulb and to limit cur-
rent through the bulb so
that a catastrophic burn-
out was prevented.
Capacitors CI, C2, C3,
and C4 serve to decouple
the stages being powered,
while all but C3 also serve
to filter out the 120-Hertz
ripple component left by
the rectifier. Capacitor C3
is of a lower value than the
others and is usually a disc
ceramic, mica, mylar, or
even paper-type, rather
than an electrolytic.
The technique of using a
small-value disc ceramic
capacitor in parallel with a
high-value electrolytic
seems ridiculous on first
glance, but becomes more
valid when you realize that
many electrolytics (espe-
cial ly older types} are as ef-
fective as a block of wood
at higher frequencies. The
low-value capacitor be*
comes necessary even in
some audio amplifiers and
with i-f amplifiers with as
low as a 50 kHz operating
frequency. It is certainly
most advisable if the stage
powers a 455 kHz or higher
i-f amplifier.
In the receiver with the
"high-pitched whistle/' the
problem was that C4 had
tD cmcuiTS
Fig. 7. An amplifier power supply using a neon glow lamp.
opened up This allowed
the now undecoupled
stages to go into a low-
frequency motorboating
oscillation and also al-
lowed I1-R2-C3 to operate
as a neon relaxation
oscillator. The frequency
of oscillation is set by the
time constant of R2'C3 and
the firing potential of neon
lamp n. The symptom was
a nauseating combination
of a whistle modulated by
a low-frequency motor-
boating oscillation.
Case No. 2
Noisy Plate Loads
Many amateur receivers,
as well as other equipment
used by amateurs both in
and out of their ham radio
hobby, may tend to devel-
op a sound that is often
typified as "frying eggs" or
"sizzling," This is especial-
ly prevalent in equipment
that is allowed to take on
moisture by being [often
improperly) stored for a
long time in a humid cli-
mate.
Some amplifier stages
are resistor/capacitor
coupled, so the plate load
resistor of the first stage in
a cascade chain will be a
resistor. Still other ampli-
fiers, such as the rf and if
amplifiers in the receiver,
are coupled through tuned
rf transformers (see Fig. 2).
In either case, internal arc-
J'Ul
ing of the plate toad, be it
resistor or rf transformer,
will be propagated through
the following stages as a
signal. In most cases, the
result is the classic frying-
eggs sound of a continuous
arc, or thunder crashes of
static of an intermittent
arc.
In a mu!tiple-i-f am-
plifier receiver or multi-
stage audio amplifier, this
noise can be a little dif-
ficult to locate, but a little
"trick of the trade" can
reduce the agony. In the
case of both types of am-
plifier, you can trouble-
shoot by removing the
tubes from their sockets
one by one, until the noisy
stage is found, A replace-
ment tube will usually
eliminate the tube from
suspicion. With the power
turned off and the tube out
of the socket, connect a
lOk-Ohm, 1-Watt resistor be-
tween the plate pin of the
tube and power supply
ground. This maneuver will
draw "plate" current
through the load resistor or
transformer and will create
the frying-eggs sound if
that load is defective, tf no
trouble is found, go to the
next stage back toward the
input and repeat the pro-
cedure.
Of course, if the bad
plate load is a resistor, then
it should be replaced when
B
T
X
u
Fig. 2. (a) Vacuum tube t-f amplifier plate circuit, (b] A
lOk-Ohm, 1-Watt resistor to ground will tell the tale.
91
FROM
"-0 L
V*i/ MAIN 1 •
TUNING
CI
lOOpF
T
X
'' 1
F/g. 3. H/grt humidity over long times will cause the trim-
mer to arc.
found. But, in the case
of i-f transformers, it might
be worth attempting to re-
pair—a luxurv that ama-
teurs can afford. This is not
merely desirable, but be-
comes mandatory if the re-
ceiver is a few years old or
the manufacturing com-
pany is no longer in busi-
ness.
Very carefully pry apart
the metal tabs holding the
shield onto the transformer
form and expose the coils
and capacitors. Be very
careful and work slowly,
because sometimes the
coil form has adhered to
the shield and will be
pulled from its mounting
if the shield is putled
off vigorously before the
wires and form are freed.
Carefully examine the fine
wires with a tiny screw-
driver or toothpick to see
that they are ac-
tually soldered to the wire
tabs or i-f can terminals.
Oddly enough, an unsol-
dered joint at this point
may work for years before
being jarred loose or be-
fore an oxide layer forms
to break the connection.
Other sources of prob-
lems are the resonating
capacitors across each
coil. If they are disc
ceramic, tubular ceramic.
or mica types, then they
may be easily replaced.
But most if transformers
use a fixed mica compres-
sion capacitor molded into
the plastic base. There is
no firm advice on how to
repair such transformers.
Try finding the metal tab
leading from the capacitor
to the terminal lug to
which the coil is soldered.
In most cases, it wtll ap-
pear to be one piece with
the lug, but close examina-
tion reveals that it is ac-
tually a sandwich assem-
bly. If you can cut this tab,
even if a little of the plastic
base must be melted to
gain access, then you are in
luck. Otherwise try form-
ing a new terminal in one
of the unused spots on the
mounting, or obtain a new
transformer.
Some old-timer elec-
tronic supply houses, espe-
cially those with a large
TV-shop clientele, may
have an old 455-kHz i-f
transformer for sate. Alter*
natively, find a dealer (or
mail order direct) who sells
J. W. Miller products. They
offer a line of i-f trans-
formers that may be exact-
ly what is required or can
be modified to meet your
needs with little effort. In
fact, it is possible that J. W,
Miller made the original
under contract to the re-
ceiver manufacturer!
Case No.3
Shorted Trimmer
Capacitors
Fig. 3 shows a converter
stage [combination mixer
and local oscillator] from a
mobile receiver made sev-
eral years ago. Transistor
Ql serves as both the local
oscillator and the mixer in
a superheterodyne design.
Transformer T1 is the i-f
transformer, while coil LI
is in the tuning circuit of
the oscillator, along with
CI and C2. Capacitors C3
and C4 are used mainly for
bypassing.
The trimmer capacitor
(C2) is a compression mica
variable and will suffer
from the same problems as
the fixed mica compres-
sion capacitors in the i-f
amplifier. These will occa-
sionally arc internally des-
pite the relatively low volt-
age applied to the tran-
sistor. The result is the
same sort of frying-eggs
sound as before, but it is
not always so easily found.
In this case, once the if
transformer and LI con-
nections are eliminated, a
0.01 uF disc capacitor is in-
serted in series with the
trimmer to block dc. If the
arcing disappears, or is
significantly reduced, then
replace the trimmer capac-
itor. Do not be tempted to
leave the apparently re-
stored capacitor in the re-
ceiver because 1) dial cali-
bration is now incorrect
and 2) the trimmer will
eventually fail more and
kill the set The trimmer
was, after alf, shorted, if
only with a high resistance.
Case No, 4
Pn Junctions
Another noise source
peculiar to solid-state rigs
is any pn junction that be-
comes reverse biased. In a
complex circuit, there may
be several such junctions
whose loss does not com-
pletely kill the receiver's
operation, so noise results.
If a pn junction becomes
reverse biased, it can pro-
duce a hiss-like ''white
noise." This phenomenon
is used as the basis for a
couple of popular amateur
antenna bridges. In the cir-
cuit of Fig. 4, there is a
noise generator made from
a reverse-biased pn |unc-
tionjn this case, a diode If
an oscilloscope with a
wideband vertical amplifi-
er were connected across
terminals A-B, you would
see a lot of "grass" on the
CRT screen.
It sometimes happens
®
• A.
Fig. 4. Diode noise gener-
ator.
that faults in capacitors,
changed values in resistors,
or certain other circuit
defects can cause a junc-
tion to become reverse
biased without completely
upsetting the dc operation
of the rest of the circuit
Consider the circuit of Fig.
5. This circuit operates
from a dual-polarity power
supply in which Vcc is posi-
tive to ground and Vee is
negative to ground. The cir-
cuit also has a differential
input stage in which the
signal is applied to the
base of transistor Ql A, and
the operating character-
istics of Ql B are held con-
stant by a fixed resistor net-
work.
In one problem involv-
ing this type of circuit
capacitor CI became leaky
(not a direct short but a
high resistance short) and
that substantially reduced
the contribution of Vcc ( + )
to the bias voltage appear-
ing at point A. This caused
the base^emitter potential
of Ql B to become re-
versed, making the b-e
junction into a noise
generator, which sees Q1A
effectively as a common-
base amplifier followed by
the rest of the high gain
stages in the chain.
Case No. 5
Noisy Transistors
There is a possibility that
a normally-biased tran-
sistor will become noisy
and drown out signals b^
ing received. If the tran-
sistor is located in a low-
level stage close to the in-
put then the gain of the
following stages makes the
problem even worse, Most
of the time, the noise is of
the familiar frying-eggs
variety with a few extra
92
i
INPUT
^\-
r
OUTPUT
1 I — NW
VBfl M
/?7
/7?
Fig. 5. Transistor wideband preamplifier.
pops and fizzes thrown in
for good measure.
Most of the time, the
type of noise I am talking
about is sensitive to heat
By making the circuit hot-
ter, you can often create
the noise (almost at will),
while makiog it colder will
cause the noise to disap-
pear for awhile. It seems,
though, that most common
thermal troubleshooting
techniques cover too much
area of the circuit at one
time.
For example, take the
common aerosol freon
'^circuit cooler" or "freeze
spray" (see Photo A} used
by many professional ser-
vicers. It can help pinpoint
the location of bad com-
ponents very quickly, if
you can keep from spray-
ing it on too many com-
ponents at once. The same
holds true for most heat
sources used by servicers.
What is needed is a
means for concentrating
the cold or heat on one
component at a time. One
solution is the use of one of
those oversize pieces of
"spaghetti'' tubing that
seems to be in everybody's
junk box from the times
when a ''universal'' assort-
ment was purchased. Sim-
ply cut one to three inches
of tubing to fit snugly over
the transistors or resistors
under suspicion. If cooling
is your goal, the tubing
allows you to concentrate
the spray only on the sus-
pect component.
For heat treatment, sim-
ply place a small incandes-
cent pilot lamp (#47 for
6-volt and #1 892 for 1 2-volt
are suitable) in the open
end of the tubing, and con-
nect it to a battery or dc
supply. It has been my ex-
perience that truly heat-
caused defects will show
up within about three to
five minutes under the
lamp. Most of them will
succumb to the increased
heat in less than one
minute.
Case No* 6
"It Goes Dead When Hot
(or Cold)"
A solid-state transceiver
was brought in for repair,
and the owner complained
that it worked in the morn-
ing, but not in the after-
noon. This problem is not
actually a noise problem,
but is so common and so
closely related to probtem
number 5 that it bears
some attention.
Solid-state circuits can
be quite sensitive to the
thermal environment, hot
and cold. Normally operat-
ing transistors will operate
over a wide range of tem-
peratures, but, when cer-
tain defects show up, then
they become abnormally
sensitive to changes in
temperature.
During the summer, your
mobile rig might work prop-
erly on the way to work in
the morning, but when re-
turning home in the late
afternoon will simply re-
fuse to do anything right.
The problem is that the car
was sitting in the hot sun
all day long, and the in-
terior is very hot. Until the
air conditioner cools off
the rig, the problem will
remain. One car manufac-
turer's radio division
measured the interior
temperatures of cars sit-
ting in the 90° F (32° C) In^
diana sun for four hours at
almost160*^ F (71 °C). Mar-
ginal solid-state devices
might quit working under
such conditions.
Winter gets in its licks,
too. A complaint is some-
times heard that the rig
does not work until the car
is halfway to work. By that
time, the car's heater has
warmed the rig up to a
temperature range where it
will work. If you think this
is a problem limited to
those in the northern states
and Canada, then keep in
mind that I am a K4, and I
have seen this problem on
many occasions.
Both problems succumb
to the same troubleshoot-
ing techniques as were
used to find noise in case
number 5. First, heat or
freeze spray a large area,
such as one corner of the
chassis or an entire printed
circuit board. Co to suc-
cessively smaller areas un-
til you are at the compo-
nent level.
Case No, 7
Internal Component
Arcing
Some noises can show
up in the loudspeaker as a
result of internal arcing
resistors, capacitors, trans-
formers, and the like.
These can be miserably dif-
ficult to find. Even when
the arcing is audible to the
naked ear, without the
loudspeaker, it seems to
come from several com-
ponents at once.
One effective technique
for locating the arcing
POWEfi SUPPLY
OR BATTERY
m
QUL9
TRANSISTOR
Ki
G)
TUBIN^i
\
PCB
Fig. 6. A short length of
"'spaghetti'' tubing will con-
centrate heat from lamp or
mist from freeze spray on
only one component at a
time.
component is to use a long,
thin section of rubber or
neoprene tubing. Hold one
end in your ear while using
the other end as a probe to
find the arcing component
The tubing will transmit a
barely audible click loudly
to your ear.
Actually, where possi-
ble, 1 prefer to use a
modified medical stetho-
scope for this purpose.
Although the professional
type used by physicians
and intensive care nurses is
quite expensive, cheaper
types are available in home
"blood pressure kits" and
in mail-order catalogues
such as Edmund Scientific
of Barrington N], Even one
from a two-dollar child's
"play doctor" kit will be
sufficient,
If you use a medical
stethoscope, be sure to
remove the metal bell or
end piece. This will serve to
both localize the source of
arcing and prevent you
from getting an electrical
shock in the case of in-
advertent contact.
It will be necessary to
scan the whole component
in many cases because the
lumen of the tubing is so
small that the device be-
comes very directional. In
fact, the resolution of this
technique is so good that
you can often tell which
end of a paper or mylar
capacitor contains the
arc! ■
93
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94
Prices and specifications subject to change without notice or obiigation.
For the serious amateur who . . .
— considers fm a vital part of a total communication system
— needs multi-band coverage in a single transceiver
— needs to continuously scan-monitor a priority amateur repeater dedicated
to public service^ weather^ or DX alerts
— needs extra programmed channels for quick selection^ in addition
to the synthesizer . . .
The Drake UV-3 provides it all!
• Continuous priority
channel scan
• Remote trunk operation
(optional)
• Four extra diode-programmed
channels on each band
• All three bands in a single
bandsvvitched unit, or start
with basic models and
add extra band-modules later
• Non-standard offsets
available for each band
The Priority Channel Scan
You can diode- prog ram your prior-
ity channel in one of the fixed
channel positions. It can be con-
tinuously monitored from any
other synthesized or fixed chan-
nel- If you're operating on the
priority channel, or another pro-
grammed fixed channel, you can
also scan-monitor any synthesizer
frequency you choose.
The Extra Diode-
Programmed Channels
You can diode-program up to four
fixed channels, with their offsets,
for each band. This feature allows
super-quick selection of favorite
channels. The five-kHz synthe-
sizer operates independently of
these programmed channels. And
best of all, soldering rs not neces-
sary for programming. The pro-
gram board has special sockets
mounted on it for direct insertion
of diodes. We even provide the
dfodes*
Remote Trunk Mount Kit
The control panel of every UV-3
removes for installation in th#
UMK-3 Remote Kit. This provides
for safety, as well as easy installa-
tion in small cars where under-
dash space is limited.
i^Dll
Write for a fully iHustroted brochure on the Drake UV-S Si^stem.
R. L. DRAKE COMPANY
DRAKE
©
540 Richard St., Miamisburg, Ohio 45342
Phone: (513) 866-2421 * Telex; 288^017
P^ Reader Service — see page 323.
95
m^
Roy Cawihon
2580 Norcross- Tucker Road
Apt. 95
Norcross GA 30071
Autophasing for WEFAX
preserve your mental health
This article will intro-
duce you to a method
of automatically position-
ing the sync pulse, or
margin, in GOES WEFAX
pictures. It is a well-known
fact among weather satel-
lite amateurs that one can
go practically nuts trying
to manually position the
margin of a picture. Even if
you do succeed in getting
the horizontal sync on the
left edge of the paper, the
strain on one's nervous
system is simply too great.
Inevitably, the phasing
period at the start of the
picture just seems too
short.
Before 1 gave up hope, I
got the idea of making the
machine phase itself. After
all, why shouldn't the
machine do all the work?
With that thought in mind,
Photo A. Photograph of the author's drum recorder. Note
the position of the solenoid. The magnet is epoxied to the
left side of the drum. The forward and reverse limit relays
are in the back corner. They remove power from the lamp
carriage when a forward or reverse limit i$ sensed. Also,
they light a corresponding indicator on the panel below
the recording head.
the following circuits were
developed. The schematics
appear in Figs. 1-5. The
result was a phasing circuit
that has proved that it can
easily place the picture
sync in the same spot each
time a photo is made. This
will help any operator's
blood pressure remain nor-
mal while he's using his
facsimile machine.
Take a look at Fig. 1 , This
circuit has the function of
a simple comparator. As
the picture drum rotates, a
small alnico magnet is at-
tached to the drum so that
it passes close by a small
relay solenoid on each
revolution. The resulting
pulse of current is used to
operate a transistor switch.
Transistor Q1 squares up
the pulse and inverts it.
Also, Q1 clamps the pulse
to TTL voltage levels. You
must make sure, however,
that you have enough
voltage coming from the
solenoid to forward bias
Q1. It may be necessary to
move the solenoid closer
to the magnet With Q1
operating, U1 A restores the
pulse to its original phase
relation and drives J1 and
also U2, pin 1.
If there were a sheet of
photographic paper on the
drum, and you had its edge
at the centerltne of the
magnet, would not the
pulse from U1A mark the
edge of the paper? Unfor-
tunately, this is not true.
There is some phase shift
introduced by the magnet
and solenoid arrangement.
You could put in a variable
phase shifting network
befo're Q1 to counteract
this, but it is much easier to
simply measure the shift
and offset the paper edge.
This need only be done
once, and a permanent
mark can be placed on the
drum corresponding to the
picture edge. I will discuss
later, in the calibration pro-
cedure, just how this is
done. For now, let's assume
the pulse from U1 A is coin-
cident with the picture
edge.
The other input to U2 is
the sync pulse transmitted
during the WEFAX phasing
period. Connector J2 is at-
tached to Fig. 5's U4B, pin
7, in my article ''Attention,
Weather Watchers! — ad-
vanced circuitry for
WEFAX processing" (7J,
October, 1978). The signal
on U4B, pin 7 is the output
of the 1700 Hz low-pass
96
video filter. During the
GOES WEFAX picture
piiasing period, the white
set pot, R52, is set to give a
pulse rising from — .5 V dc
to ground at U4B, pin 7.
This wi!l be the correct
white current setting for
the GOES WEFAX. Mean-
while, back in Fig. 1, U3A
accepts the —.5 V dc-to-
ground sync pulse and buf-
fers it The second section
of U3, U3B, converts the
sync pulse into a TTL-
compatible waveform.
Now, we can finally talk
about U2. IC U2 has only
one purpose in life. Its out-
put sits high as long as the
sync pulse in the WEFAX
phasing period and the pic-
ture edge pulse, from U1 A,
are not overlapping in
time. Assume, for the mo-
ment, that the picture
drum is turning in phase
lock with the satellite
video. Usually, some time
difference exists between
the actual picture edge
and the satellite sync
pulse. This indicates that
the picture is not phased
properly. If an error in time
exists, U2, pin 3 is high. I
call this a phasing error. If
U2, pin 3 happened to be
low, the picture phase
would be okay.
If U2, pin 3 is high, you
need some way of reducing
the time difference be-
tween the two pulses to
zero. One way is to slightly
reduce the frequency of
the phase locked 60 Hz go-
ing into Ml in Fig. 1. If this
happens, the picture edge
pulse on U2, pin 1 will
slowly drift or roll when
compared with the WEFAX
phasing period pulse at U2,
pin 2. Eventually, the two
pulses will cross, and both
inputs to U2 are high. At
this moment Ml must be
phase locked back on the
satellite subcarrier so that
the picture edge will drift
no further. The phasing
would then be accom-
plished.
The method of reducing
the speed of Ml slightly is
seen in Fig, 2. I use a pro-
Photo. B. This is an inside view of the unit seen below the recorder head in Photo A, The
two cards at the right front are the auto-phasing circuits. The S1-1025E power amp is on
the heat sink in the right corner. The transformer in front of it is 77. A 300 V dc power sup-
ply for the R1 1-68 is on the subchassis and it uses five tubes. The five-inch fan at the back
keeps things cool. My video processing circuits are built on the four cards at the leftside
of the chassis. The meter is the lamp current indicator.
grammable divider to con-
trol the speed of Ml, ICs
U5 and U6 comprise the
divider. The divider is
capable of dividing the
2400 Hz reference, from
Fig, 4, by 40 or 41 . Normal-
ly, when the picture phase
is okay, U2, pin 3 is low.
SMALL ALNICO Mfl^NET EPOXIED TO DRUM
BLACK
COIL FfiOM &MALL RELAY
ADJUST GAP BETWEEN
MACNET AND COIL FOR
IV P-P ON DASE OF Q
+ 5
£^2270
R2
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Ml
240 fiPM
5 WATT
HURST SYNC MOTOfl
MODEL CA
TO FJS, 3
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TO FSG 3
7404
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TRfG. TO Jl
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7400
OFFSET ADJUST
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SEE TEXT
1
Fig. 1. Sync comparator.
97
FROM FIG I
PHASING
ERROR LEti
_El MANUAL PHASE
"3,
FROM F3G 4
1^ 60 Hi or
|C> 56-536 Kz
i>^ TO FIS 3
This sets the Q-output on
ffip-flop U4A to one. The
phasing-okay LED, CR1,
now lights, and the correct
bi-quinary word is loaded
into the divider to do divi-
sion by 40. U6, pin 8 now
supplies a 60 Hz locked
reference to the low-pass
Fig. 2. Programmabte divider.
filter in Fig. 3 and, in turn,
to the motor amplifier.
As soon as the WEFAX
phasing period starts, it is
necessary to test the pic-
ture phase. At this mo-
ment, the start button, S3,
is depressed and flip-flop
U4A is cleared. The
phasing-effort LED will
now come on, and the pro-
grammable divider is in-
structed to divide by 41.
The picture edge pulse
begins to drift slowly now
with respect to the
reference, since the drum
slowed down. The drum
*^' nzz ^^
\ w^ V J[ _.
FROM FIG 2
TO FiG. I
TO FtG. I
TO FlO \
98
n
Fig. 3. 70 Hz low-pass filter and power amplifier.
motor is now running at
58336 Hz. IC U2 is now
looking for the time when
the two pulses will cross.
The frequency of 58.536
Hz provides a slow enough
drift so that the two pulses
do not happen to miss each
other. Also, it is slow
enough so that the results
obtained are repeatable.
That is, it puts the margin
in the same place each
time. As soon as the two
pulses cross, U2, pin 3
switches low and U4A is
set The phasing-okay LED
now comes on, and divi-
sion by 40 is loaded again
into the divider. The syn-
chronous motor, M1\ jumps
extremely fast to the prop-
er speed so that the margin
remains properly phased.
You now have the pic-
ture phasing accomplished
with a minimal amount of
work on your part. Perfec-
tionists should be able to
eliminate the start button
by utilizing a 300 Hz band-
pass filter to detect the pic-
ture start tone. This start
tone immediately precedes
the phasing period. The
filter could feed a peak
detector and, in turn,
charge a capacitor. Next,
the voltage on the
capacitor could be sensed
by a voltage comparator
and used to fire a one-shot.
The one-shot could control
U4, pin 13. I haven't incor-
porated this into my
system, since I have
chosen not to eliminate
myself entirely from the
process.
Now, suppose t had
chosen to manually phase
the picture, or, for some
reason, I missed the phas-
ing period. The phasing
switch, S2, is set to manual.
The manual phase button,
S4, xs simply held de-
pressed. At this point, a
monitor oscilloscope is
necessary. The scope must
have its timebase set to 250
ms, and then it must be ex-
ternally triggered by the
pulse on J1, Also, the
satellite video is supplied
to the scope's vertical
Photo C This is an overall view of the author's GOES
WEFAX station. The scope on the top is a customized
Tektronix 5616. !t is used in conjunction v^ith the
Tektronix C-27 camera to make 4 by 5 Polaroid^^ prints of
WEFAX pictures. The tape deck is seen in the rack below
the 561. Below the tape deck is the drum recorder in its
protective enclosure. The door opens down and the
machine slides out The scope below this is used as a
waveform monitor ft is used for manual phasing and
checking signal quality. Betow the monitor is the machine
that powers the drum recorder head. It does the video and
sync processing. Also, it contains the power amplifiers for
the motors. My receivers are housed in a separate rack and
were not shown here. I use a 200-channel synthesized
radio for 136-138 and a double-conversion custom-built
receiver for GOES.
amplifier. The scope
screen now depicts what is
happening on the paper
drum one line at a time. If
the position the sync pulse
takes during auto-phase is
known, you can manually
move it there now by
holding down the manual
phase button, S4. When the
pulse arrives on its desired
position, S4 is simply
released.
Finally, the input fre-
quency for the program-
mable divider, U5, pin 6, is
generated in Fig, 4. To
begin, a 2.4 MHz oscillator
module was purchased
from International Crystal
Mfg. Co. The 2.4 MHz TTL
square wave is buffered by
UIDandUIE. ICsUg, UIO,
and U11 divide the 2.4
MHz down to 2400 Hz.
During real-time operation,
the 2400 Hz is fed directly
to the programmable di-
vider by S5. Also, it may be
recorded on tape via
capacitor C39 for playback
later. During playback, the
2400 Hz that was recorded
on tape locks up U12. U12
is a phase locked loop chip
that has its vco adjusted to
free run on 2400 Hz by R29.
The purpose of U12 is to
compensate for any speed
variation in the tape deck
and also to provide a clean
signal for the program-
mable divider.
There you have it; you
now have a complete State-
of-the-art phasing system
for the new GOES WEFAX
broadcasts.
Calibration Procedure
First of all, check the wir-
ing before applying power.
These circuits should work
the first time if the wiring is
okay. After giving every-
thing a thorough going
over, turn on the power
supply. Check to see that
the voltage levels are cor-
rect and that the ripple is
4
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4
CR4
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SYNC OUT
TO TAPE DECK
E?ISNT CH.
J4
SEJ DECK FOft x
SYNC FROM
TAPE
C4Z
ts
4
R£7
4.7K
L
iO
565
4.7 K
t;43
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■ft46
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fl
R29
R42
6 BO
C)9
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UC23
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C£2
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Fig. 4. Sync generator.
99
Photo D. This is an example of a properly phased GOES WE FAX picture. It was received
and processed by the equipment /n Photo C
low. The ripple should only
be several mV p-p. Next,
measure the voltage be-
tween Ue, pin 1 and Ufl,
pin 4. With R23 adjusted
fully CCW, the voltage
should be about 50 V dc.
Now, connect a dc-cou-
T3
TRIAD
ON BLK/YEL F'9£A ^pf,^
CR5
V&-644
<-^
115 VAC > "1
)
S2
ON BLK/qED
^ VEL
1
fiEO
t1(
C2&
IIOO^F
^
-15
T C30
IJI4
m
B
C2e
50V
^hr
fh
+15
1.
X
C52
/77
fl
X
C34
'p* .47itF
1
/77
C35
50V
UI7
MC7805
m
C36
.47^F
Fig. S. Power supply.
pled scope to U11, pin 12
and check for a 2400 Hz
square wave. Connect a
counter to UlE, pin 10
and check the oscillator,
OSC-1, for 2.400,000.0 Hz.
Move the counter over to
UIF, pin 12, and, with S5 in
real time and j4 discon-
nected, adjust R29 for 2400
Hz. Switch S2, the phasing
switch, to manual and con-
nect the counter to U6, pin
8. You should read 60 Hz.
Next, depress the manu-
al phase button, and the
counter should read 58.536
Hz. This checks the divider*
Release the manual phase
button and connect a
VOM, on a high ac voltage
range, across the blue and
brown wires on the second-
ary of T1. Adjust R23 CW
until 117 V ac is read on the
meter. Ml should now be
running. Next, move your
dc-coupled scope to the
base of Q1. Check the am-
plitude of the pulse from
the magneto. You need at
least 1 voit peak to ensure
that Q1 turns on. The
positive half cycle will for-
ward bias Q1. If the pulse
level is too low, move the
solenoid in closer to the
magnet. Move the probe to
the collector and check for
a TTL pulse of approx-
imately 10 ms duration.
The inversion of this pulse
will be on )1.
It is now necessary to
use a GOES WE FAX signal.
A prerecorded signal will
be desirable. With the cir-
cuits completed and test-
ed, as described in '^Atten-
tion, Weather Watchersl",
connect J2 to U4B, pin 7 in
the video filter. Switch
both function switches to
playback, start the tape,
and adjust the white set
pot for a pulse that rises
from —.5 V dc to ground
during the phasing period
at U4B, pin 7. Next, adjust
R5 in Fig. 1 for a zero-to-
five-volt pulse on U3B, pin
7. Finally, with 52 in auto,
start the tape at the begin-
ning. The phasing-okay
LED should be on as the
drum spins. As soon as the
phasing period starts,
check the picture phasing
by pressing the start but-
ton. The error LED will now
come on and will remain
on until the two pulses
cross. When the two pulses
cross, the phasing-okay
LED will come on, indicat-
ing that phasing was ac-
complished.
1 mentioned earlier that
there is a phase shift in-
troduced by the magnet
and the coil that offsets the
true picture edge about an
inch or so. The easiest way
to correct this is to find the
point on the drum that cor-
responds to the actual pic-
ture edge. To do this, you
will need to load the drum
with photographic paper
and place the paper's edge
in line with the magnet's
centerline. Now, start the
too
Parts List
CI
.1 uF, 50 V monolytic (mono)
R14
C2
.1 uF, 50 V mono
R15
C3
.71 uF. 100 V mylar*
R16
04
,065 uF, 100 V mylar*
R17
C5
1.46 uF. 100 V mylar*
R18
C6
.024 uF, 100 V mylar*
R19
07
Zm uF, 100 V my far*
R20
C8
,1 uF, 50 V mono
R21
C9
A uF, 50 V mono
R22
C10
I.OuF, 50 Vmono
R23
011
2200uF, 50 V electrolytic
R24
012
50 uF, 50 V electrolytic
R25
013
.047 uF. 1D0V mylar
R26
014
3450 uF, 75 V electrolytic
R27
CI 5
.5 uF, 400 V (supplied wfth M1)
B28
016
,1 liF, 50 V mono
R29
017
J uF, 50 V mono
R30
018
.1 uF, 50 V mono
R31
019
.047 uF, 100 V 10% myJar
R32
020
.1 uF, 50 V mono
R33
021
,1 uF, 50 V mono
R34
022
.1 uF, 50 V mono
R35
023
.001 uF, 50 V mono
R36
024
250 uF, 25 V electrolytic
R37
025
1100 uF, 50 V electrolytic
R38
026
1100uF, 50 Vefectrolytic
R39
027
.016uF, 10% myiar
R40
028
,47 uF, 50 V mono
R41
029
.033 uF, 50 V 10% myiar
R42
C30
100 uR 50 V electrolytic
R43
031
1500 pF 5% silver mica
R44
032
100 uF, 50 V electrolytic
R45
033
,O47uF,5OVl0% myJar
R46
034
.47 uF, 50 V mono
R47
035
too uF, 50 V electrolytic
R4a
036
-47 uF, 50 V mono
SI
037
-1 uF. 50 V mono
S2
038
573 pF in parallel with 12 pF 5% stiver mica
S3
039
1.0 uF, 50 V mono
S4
040
.1 uF, 50 V mono
S5
041
.1 uFj 50 V mono
T1
042
I.OuF, 50 V mono
T2
043
5 uF, 25 V electrolytic
T3
CR1
1.7 V, 20 mA LED
T4
CR2
1.7 V, 20 mA LED
CR3
VS-644 bridge rectifier assembly, 600 V # 2 A
U1
CR4
1 N93TA
U2
CR5
V&-644
U3
F1
1 Amp siow blow
U4
J1
BNO female chassis mount connector
US
J2
6N0 female chassis mount connector
U6
J3
BNO female chassis mount connector
U7
J4
BNO lema e chassis mount connector
US
M1
240 rpm 5-Watt synchronous Hurst motor model CA
Q1
2N2270
U9
Q2
2N2270
U10
03
2N2270
U11
R1
680 Ohm, % W10%
U12
R2
Ik Ohm, V4 W10%
U13
R3
47 Ohm, V4 W 10%
U14
R4
47 Ohm, V* W 10%
U15
R5
20k 1-Watt wire- wound 20-tum PC pot
U16
R6
100k, V* W 10%
U17
R7
10k RN55 1 %
uie
R8
10k RN551%
0SC1
R9
90.9k RN551%
RIO
3,3k, % W 10%
R11
220 Ohm, V4 W 10%
R12
10k Ohm, % W10%
R13
10k Ohm, V4 W 10%
3.3k, Va W 10%
3.3k, V* W 10%
10k RN55 1%
10k RN55 1%
l0kRN55l%
10kRN55 1%
10k BN55 1.%
47 Ohm, % W 10%
47 Ohm, V* W 10%
10k, 1 W wire-wound 20-turn pc pot
10 Ohm, % W 10%
464 Ohm RN60 1%
22k, % W 10%
4.7k, V* W tO%
4,7k, V4 W 10%
5k Ohm, 1 W wire-wound 20- turn pc pot
3.3k Ohm, V* W10%
3,3k Ohm, V4 W 10%
10k RN55 1%
10kRN55 1%
l0kRN55l%
10k RN55 1%
10k RN55 1%
50k. 1 W wire-wound 20-turn pc pot
33k, Va W 10%
Ik, V4 W 10%
47 Ohm, V* W 10%
47 Ohm, y- W 10%
660 Ohm, V* W 10%
too Ohm, V4 W 10%
47k, % W 10%
10k, V* W 10%
10k, V4 W 10%
47 Ohm. V* W10%
47 Ohm, V4 W10%
SPDT 120 V toggle
DPDT 120 V toggle
SRST push-button
SPST push-button
SPDT toggle or rotary switch
TRIAD S-24A 8-Ohm^t0^8k'Ohm, 15 W
TRIAD F-93X
TRIAD F-92A
solenoid from a relay— I use a coil from a model
KRP11AG Potter and Brumfteld.
SN7404
SN7400
M01458
SN7474
SN74196
SN74196
MCI 458
Sanken S1-1026E hybrid power JO. An SM020 is a
good substitute.
SN7490
SN 7490
SN7490
LM565
MCI 458
MC7915CP
LM741
M078150P
MO7805OP
SN7430
International Crystal Mfg. Co. OE*l oscillator module.
'The desired value is obtained by paralleling two or
more capacitors. Use a good quality capacitor. The
value doesnH have to be exactly on the calculated
value shown.
101
drum, turn on the tape
deck, and wait for the phas-
ing period to start. As soon
as it begins, depress the
start switch and allow the
machine to phase. Next,
switch on the lamp and
allow part of the picture to
expose. Remove the paper
and develop it. Note the
position of the sync on the
paper. Place the developed
picture back on the drum
the same way it came off.
Make a small mark on the
drum corresponding to
where the sync is on the
paper. Remove the paper
and scribe a line on the
drum where the mark is.
This line is to be used to in-
dicate where the paper's
edge will go from now on
each time the drum is load-
ed.
Load the drum with a
fresh sheet of paper and
place its edge along the
new line. Remake the tape-
recorded picture once
more. Allow the drum to
phase automatically. This
time when the phasing is
accomplished, the sync
will be positioned at the
edge of the photo. If you
make pictures in the re-
verse direction, a phasing
mark will have to be
located for the opposite
direction, also. To do this,
the above process will
have to be repeated. When
you finish, there will be
one mark on the drum for
pictures made in the for-
ward direction and one for
the reverse direction.
Please take careful note
of the photos showing my
station. Details of the
solenoid and magnet may
be seen in the picture of
the recorder. Good luck in
getting your system on the
air. If you have come this
far, I am sure you have
quite a station by now tf
you have any questions,
please include an SASE.
from page 1$
suggest an imaginative and
potentially beneficial public
service television concept and
that this type of communica-
tions activity is one which
deserves considerable atten-
tion in the overall inquiry."
The FCC requested com-
ments in BC Docket No. 78-253
from all interested parties.
These comments are due (orig-
inal and six copies) at the FCC.
Washington DC 20554, by De-
cember 11, 1978.
S,e. PI Her W2K PQ
President
Communlcasting Association
of America, Inc.
Syosset NY
FRESH VIEWPOINT
]
Being an active amateur for
three years and hoping to be
one for at least another thirty, I
feel inclined to respond to your
crilicism of the ARRL From my
Novice days on, I have been
brought up on the thinking and
ways of the League. On the
whole, this organization has
been superb in helping me
grow in the hobby. Many new
things have come about, and
ham radio is still around
because of the League,
At this point, the accolades
end and the real essence of my
correspondence surfaces, fn
the beginning, you and your
magazine really rubbed me the
wrong way, and, as usual, I
merely discarded your com-
mentaries. Well, I guess
everyone grows up, and after
many hours of mental soyt-
searching and objective
meditation, I finally saw the
light.
Mr. Green, thank you very
much tor providing about the
only fresh viewpoint in a too-
long monopolized field. It
seems that we hams have
become far too complacent in
our thinking. This is undoubted-
ly a very dangerous and un-
healthy situation.
Although there are points of
disagreements in our thinking,
at least you have spurred my
mind to realize the presence of
other possibilities. I now read
the rebuttals you receive from
other hams and can see the
fear I once experienced, I can
onJy urge ail my counterparts to
just stop for a few minutes and
examine their way of thinking.
Ham radio is going through
an amazing period of change
and growth, and it certainly
needs more than one voice to
express its needs, I personally
wish you good luck in your at-
tempts concerning the upcom-
ing WARC. and thanks again,
Michael A. Roscoe K3VK
Sharon PA
ATLAS CLASS
J
in the past, you Ve printed let-
ters from WA5TUM and AA6US
commending Atlas Radio and
their service. All I can say atK>ul
Atlas service is. 'TANTASTIC,'*
On September 20. my Atlas
350-XL became inoperative. I
called Clint Call at Atlas and,
after describing the problem,
Clint told me to send the 350-XL
and p/s to Steve Grossman at
Communications Specialties in
Erie PA. collect. The units were
shipped via UPS that day and
on September 27 at 6:30 pm, my
3SOXL was back on the air at
my QTH. Not only was the rig
repaired, but it was updated
with the latest modifications,
all for no cost or shipping
charges.
I can't praise all of the per-
sonnel at Atlas too much, as
they are not only gracious, but
helpful to the nth degree. Atias
Radio is setting a precedent
and building up a reputation
that is going to be hard to beat.
Now, a few words about 73.
It's in a class by Itself, Were it
not for 73, K2QHI would have
been relegated to "appliance-
operator" status a long time
ago, but the plethora of con^
struction articles keeps my
hands t>usy and my soldering
irons hot. Keep up the good
work, Wayne.
Michael Stefanik K2QHI
Garfield NJ
WHICH MAGAZJNE?
After reading the letters in a
few of the past issues. I feel
compelled to write in answer. I
have subscribed to both 73 and
QST for the past three years,
and wish to ask (and answer) a
few questions about these pub-
lications:
In which magazine can you
find the most useful articles,
divergent points of view, letters
printed on both sides of a ques-
tion^ letters attacking the
magazine as well as praising
it? in 73. In which will you find a
publishing philosophy which
accepts opposing points of
view, which screens its adver-
tisers for reliability, which will
accept letters proposing
almost anything? In 73, In
which will you find editorials
which most likely are represen-
tative of a majority of its
readers, if not of amateurs In
general, and which doesn't
flip-ftop" on the issues? In 73.
In which will you find a
multitude of column inches
devoted to relatively useless
columns, and claims of repre-
sentation of the amateur while
trumpeting nonrepresentative
views? In QST. In which will you
find the most apologies for a
bumbling FCC, and the most
"official reportage" with the
least member input? In QST.
Which magazine can usually be
relied upon to review a ''new"
product long after it has been
on the markets or to fail to reply
to a proposal or letter? QST.
I don't for a moment be-
grudge these fellow amateurs
their opinions, and I applaud
your printing of them, bul I just
can't figure out what's so great
about the League, It has its
good points, just as 73 has its
t}ad points, but on the balance,
ril take r^ anytime.
R. J, Edmunds WB2BJH
Kinnelon NJ
QTH I NO
IL
For many years t have been
thinking of writing to the
various amateur magazines on
the following subject, but kept
putting it off. However, Tm
finally getting around to it.
I have been on the air about
fifty years. During that time,
when I called a CQ, I have
always given my location (QTH)
since I feH many amateurs
wanted to know where the call
was coming from, and there is
always the chance they might
have phone-patch traffic for my
location.
Back in the old days, when
someone signed W1, W2, W3,
etc., one always had a general
idea of his location, but with
the complete jumble in call
assignments by the FCC re-
cently, one does not know if the
call is from their neKt-door
neighbor or from Timbuktu,
I would like to suggest that a
movement be started by the
various magazines to have
Contmued on page 116
102
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1^ Header Servian— set ptige 323.
103
The Lunch Counter
eat it up
Johnny C Chestnut WA4FIN
801 /v. RamofiQ A venue
Indiatamic FL S290J
John L. Woicott W4CCX
490 E, Riviera Blvd.
Indialanttc FL 32903
The Lunch Counter proj-
ect was designed, from
start to finish, as a ham
•
The finished Lunch CountCL
project with ham specif ica-
tions. Its primary goals
were that it:
1)be technically up to
date;
2) be easy to build;
3) use readily-obtainable
parts; and
4) involve easy case fabri-
cation.
As you may have already
surmised from the name,
the entire project was con-
ceived and designed dur-
ing a series of eyeball
QSOs over lunch, A few
evenings were used to
build the prototype.
All of the particrpants
work in electronics in some
capacity, but none of the
work was done within our
respective fields of exper-
tise. As an example, we
elected our professional
program manager to be the
prototype technician, on
the theory that the ex-
perience would be good
for him. While only two of
us wrote this article,
acknowledgement is given
to WA4QCE for mechani-
cal design, WB4CDP for
104
Interior views showing construction details and PC board mounting.
layout and drafting, and
WB4UDI and WB4WWI for
parts procurement.
We made a detailed
evaluation of advertise-
ments for available fre-
quency counters. It soon
became obvious that the
art of digital frequency
counters has progressed
remarkably in the past few
years as the newer ir>-
tegrated cfrcuits have
become available. As the
semiconductor wizards
pack more circuitry into an
integrated circuit, the
overall size goes down, the
device capability goes up,
and, best of all, the cost
goes down. After all fre-
quency counter ads and
construction articles were
reviewed and summarized,
our appetites demanded
the best features from
each, and, of course, no
one counter met all our
desires.
Specifications
At this point, we devel-
oped a target specification
which would satisfy all of
us.
1) Cost — cheap, to fit a
ham's pocketbook.
2) Display — six digits, big
enough to read.
3) Frequency range — from
audio (touchtone^'^ pads)
through all the popular
amateur bands (1 .8 MHz to
450 MHz),
4) Sensitivity — sufficient
for most solid-state rigs.
but not sensitive enough to
produce unnecessary count*
ing on noise (10 nnV to 25
mV),
5) Accuracy— ±10 Hz to
±100 Hz is usually fine for
most amateur purposes. A
good quality crystal can be
adjusted to better than 10
parts per million and will
easily meet these criteria.
6) Stability — stable over
the temperature range en*
countered in the ham
shack We did not expect
to use it outside of normal
room temperatures. Long-
term stability should be
good enough to maintain
accuracy between calibra-
tion checks, which are six
months to one year for
most users,
7) Size — small enough to
fit in the palm of the hand,
but large enough to have
an easy-to-use front panel.
8) Power— 12 V dc was the
choice of most of us who
participated in the devel-
opment. Most new solid-
state rigs operate on 12 V
dc, and a 110 V ac power
supply is easy to build for
those who desire it.
Design
The design that evolved
over many lunch hours is
shown in the block dia-
gram in Fig. 1. The circuit
was divided into three
functional boards — timing,
counter, and display The
timing board contains the
oscillator, dividers, and
timing to control the
counter board. The count-
er board contains the six
decade counters, latches,
and seven-segment display
drivers. In addition, it has
the input amplifiers and
high-frequency prescaler.
The display board holds
the six LED displays Power
requirements are met by
the use of a three-terminal
regulator to obtain 5 V dc
from an 8-16 V dc supply.
Schematic details began
with the selection of the
74C925 as the workhorse of
the counter. This is a new
counter chip which has a
full four stages of counter
built in with the necessary
latch, seven-segment de-
coders, and LED drivers It
also multiplexes the out-
put drivers, thus greatly
simplifying the wiring to
the displays. Comparing
this single 16-pin in-
tegrated circuit to an
equivalent set of conven-
tional f o u r- d i g i t T T L
counters, twelve in*
teg rated circuits, twenty-
eight resistors, and twenty-
eight wires to the display
are now replaced with one
integrated circuit, seven
resistors, four transistors,
and eleven wires to the
display board.
Since the design criteria
called for a six-digit
counter, two more stages
must be added By using
74LS90 counters for these
stages, the frequency
range of the basic counter
CRYSTAL
DEC^E
T 1U.PBJ^r^
BOARD
^
OSCILLAtOR
I
COUNT EHS
—
riaf t
—
■ —
F!E3ET
r 1
1 i-
n T^u
.
V* • b
J
U -t^ ' V ri
OtRECT
mPUT
1
h
1
f
DISPLAY
BOARp
1
1
1
INPUT
SWITCH
^
COUNTERS
DECOOEH
DRI^IRS
DISPLAY
1
1
PRESCALE
II
^pyT
COUNTER BOA^D
fig. 1. Lunch Counter block diagram.
105
Top view showing parts layoul of timing board
will cover to 50 MHz. The
associated latch and
decoder/LED drivers for
these two stages use 9368s.
This device saves a couple
of integrated circuits by
combining the latch, de-
coding, and driving func-
tions, but the resistors and
wiring to the LEDs are
cumbersome when com-
pared to the multiplexed
74C925. It must be noted
that the digit "9" on the
9368 and the 74C925 are
decoded differently-
The input stages to the
counter are either the
amplifier, for direct input,
or the divide-by-IO pre-
scaler. A front panel switch
is used to select the direct
input or the prescaler
through a 74LS00 gate so
that the high-frequency
signal path is always from
one integrated circuit to
the next. The DIRECT/
PRE-SCALE switch only
switches a dc control
voltage. The 11C90 pre-
scaler was selected
because its frequency
range exceeds 500 MHz. It
also has the ECL-to-TTL
conversion built in and
therefore does not require
additional transistors for
level conversion. The
prescaler divides the high-
frequency input by 10, so
its output is within the
50-MHz range of the basic
counter. In this process,
the last digit is dropped
from the count, and the
decimal point is therefore
moved one place to the
right,
The function of the tim-
ing board is to generate the
timebase and control func-
tions for the counter. An
accurate gate is required
which will allow the count-
er to count its input for a
known period. The counter
uses either a one-second
gate for kilohertz or a one-
millisecond gate for
megahertz. The timing
board also provides latch
and reset pulses to update
the display. The latch pulse
updates the display with
the previous count, and the
reset pulse clears the
counters prior to starting a
new count.
Our original design used
a 1.3'MHz crystal because
we already had a few avail-
able. The first stage follow
ing the oscillator was a
74L193 programmed to di-
vide by 13, After we conri-
pleted the printed circuit
board artwork, the plan to
make the Lunch Counter
into a club project devel-
oped. At this point, we
modified the artwork to
permit the use of a more
readily available 1.0-MHz
crystal as an option
The power supply is
simply a S-terminal regu-
lator bolted to the rear of
the chassis with the bypass
capacitors soldered direct-
ly to the terminals and a
solder lug under the
mounting screw. We used a
small heat sink to reduce
the regulator temperature,
but several have been built
using just the chassis for a
heat sink with good results,
A parts list for the Lunch
Counter is included with
this article. The parts are
easily available through
advertisers listed in any of
the ham radio magazines,
such as 73. The nC90 and
74C925 are the most expen-
sive parts and the 9368s
come in a close third.
Construction
Construction is very
straightforward Printed
circuit board assembly
should be started with the
jumpers on the component
side, followed by the in-
tegrated circuit sockets,
and then the remaining
components. The display
board is mated to the
counter board with cutoff
resistor leads or bits of
hookup wire bent at a right
angle. Both boards may be
mounted In the cabinet
with long bolts and stand-
offs. Wiring between
boards, the switches, in-
puts, and power supply
completes the wiring. The
boards are then mounted
in the cabinet and the LEDs
lined up with the window.
The case is widely avail-
able through Radio Shack
stores. A silk-screened
front panel gives the unit a
professional appearance
and makes the construc-
tion easy. Cutting the rec-
tangular hole in the front
panel may be the most dif-
ficult part for some
builders, A nibbling tool
Timing board — component side.
Timing board — foil side.
106
vcc
tOOHj
lOHt
vcc
LATCH
LATCM GAtE
INPUT @- ^f
TV
INPUT ®— f
IC
VCC PtW
OHD P«r4
ui, i* % tS, 13
14
r
III*T^ 14, 16
a
lO
uto
4. 6, 7, 10
ti
«|l»
***
12,13,14
UlS, IT. IB
l«
B
Fig, 2, Schematic.
does a good job on this
hole. Some of us used a
Dremel tool to cut out the
hole. We then glued a red
piece of Plexiglas"^^ to the
back side of the hole.
Suggested Wiring Se-
quence
1. Jumpers under sockets
"10 total,
2, Sockets — remove un-
used pins from display
sockets.
3. Ail other onboard
jumpers.
4. All other components.
5. Mount display board to
counter board.
6. Wiring between boards.
7. Mount front panel on
cabinet; drill holes and cut
window.
8. Mount PC boards in
cabinet
9. Complete mechanical
assembly.
10. Complete wiring.
Calibration
The only alignment re-
quired is to put the oscil-
lator exactly on frequency*
We made provisions for a
fixed padder (C2) in paral-
lel with the trimmer (CI) to
be used if necessary. If the
oscillator adjusts to the ex-
act frequency with the
trimmer alone, C2 is not
needed. If the oscillator
frequency is too high with
the trimmer, CI, fully
meshed, C2 should be add-
ed to tower the frequency.
Note that a low oscillator
frequency will result in a
high count when using the
frequency counter. The
most accurate alignment
method is to use the
counter to count a known
laboratory frequency stan-
dard. A frequency above
10 MHz is preferred to ob-
tain the best accuracy.
Alternate calibration
107
Counter board — foi} side.
sources would be a 100-
kHz crystal calibrator or an
oscillator zero beat to
WWV. Also, there have
been several magazine ar-
ticles on using the TV color
burst frequency as an ac-
curate standard,
Troybleshooting
The counter should read
all zeros (the last digit may
read 1) with no input signal.
If it does not, the following
sequence of troubleshoot-
ing is suggested:
1 . Double check al I
jumpers and wiring.
2. Check for 5 V dc on each
IC as per pin connection
table on the schematic
3. If individual segments of
one or more LEDs do not
light, check the display by
interchanging LEDs, and
check wiring and solder
joints on the display and
counter boards.
4. If one LED does not
light* check the corre-
sponding driver IC and/or
transistor.
5 If the display lights but
does not reset, check the
following:
a. Check the oscillator
by connecting a scope
to pin 6 of U1- You
should see a 1-MHz
square wave.
b. Check the GATE
pulse by connecting a
scope to pin 9 of U10
You should see a 1-ms
square pulse (MHz-kHz
switch in MHz}.
c. Check the LATCH
pulse by connecting a
m
•^
1
Counter and display boards showing parts layout
Display and counter boards showing LEDs and mounting
technique.
scope to pin 11 of U8.
You should see a 0.1 -ms
square pulse every 2 ms.
d. Check the RESET
pulse by connecting a
scope to pin 3 of U8. It
should look exactly like
the LATCH pulse.
e. Check for correct
GATE. LATCH, LATCH,
and RESET pulses on
LC2.
6. If the display lights but
does not count, check the
following:
a. Connect the 100-kHz
test point to the DIRECT
input Put the DIRECT/
PRE-SCALE switch in
DIRECT and check for a
100-kHz square wave at
pin 4 and pin 11 of U13.
The display should read
000100 with the MHz-
kHz switch in MHz.
b. Move the input signal
to the PRE-SCALE input,
put the DIRECT/PRE-
SCALE switch In PRE-
SCALE, and check for a
10-kHz square wave at
pin 1 and pin 11 of U13.
c. Check for a 10-kHz
square wave at pin 1 4 of
U14 and a 1-kHz square
wave at pin 4 of U14.
d. Check for a 1-kHz
square wave at pin 14 of
U16 and a 100-Hz
square wave at pin 4 of
U16.
Use
The direct input is
generally used for frequen-
cies under 50 MHz. The
timebase switch may be set
to either the MHz or kHz
position. The decimal
point on the readout is
located after the third digit
to correspond to MHz or
kHz. In the kHz position,
the least significant digit is
0.001 kHz or 1 Hz, When
reading frequencies above
1 MHz, you can read to the
nearest kHz in the MHz
position, then switch to the
kHz position and read the
last three digits to the
nearest Hertz.
Between 50 MHz and
500 MHz, you must use the
prescaled input. The pre-
scaler divides the input fre-
quency by 10 and does not
display the least significant
digit. Therefore, the
decimal point is moved
one place to the right to
properly index the display.
By using the MHz/kHz
switch, a prescaled fre-
quency can be displayed to
the nearest 10 Hertz
Accuracy, temperature
stability, and long-term
drift of any counter are on-
ly as good as the crystal
timebase. Most reasonably-
accurate 1-MHz crystals
can be trimmed to exactly
1 MHz with a little care, so
the initial accuracy will de-
pend on the facilities you
have for calibration Tem-
perature stability and long-
term drift depend on the
crystal quality and the
108
oscillator circuit. In the
counters we built, these
two effects were less than
0.0005% over normal
room temperature. After
all, we did not intend to use
the counter at tempera-
tures where we do not
function welf For greater
stability, a high-quality
crystal and oven can be
used.
The sensitivity of the
Lunch Counter was mea-
sured as 10 mV up to 50
Mhz in the direct mode
and 50 mV up to 500 MHz
in the prescale mode This
is sufficient to measure
most transmitters using a
short antenna on the input,
without a direct connec-
tion. The most important
caution is not to overcou-
ple to the counter, Ex-
cessive input causes multi-
ple counts and a reading
much higher than ex-
pected. Of course, if you
couple too much energy in-
to the input, you can
damage the input circuitry.
Diodes are provided across
the inputs to reduce this
possibility,
As the word of our proj-
ect spread through the
local club, it was soon ap-
parent that a counter was
of universal interest. As a
result, boards were made
available, and more than
50 were constructed by
members of the Platinum
Coast Amateur Radio
Society.
We had a lot of fun
designing and building the
Lunch Counter. We have
met our goals of a simple-
tO'build counter with ex-
cellent specifications, and
it has generated a lot of in-
terest as a local club proj-
ect. By using a good case
and a good-looking front
panel, any ham should
be able to make a
professional-looking piece
of test equipment like the
ones which are now in-
dispensable in our shacks.
The three printed circuit
boards, a 0.020-inch-thick
aluminum silk-screened
front panel with adhesive
back, and documentation
are available from Johnny
Chestnut, 801 N. Ramona
Avenue, Indialantic FL
32903. for $12.50 post-
paid. ■
Parts List
Capacitors
Size
CI
10-60 pF trimmer
C17
100 pF
09
0.001 uF ceramic disc
03, 04, C11, 012
.015.
020
, C22, C24
0.01 uF ceramic disc
06, 07. C8, CIO. 1
014, C16,
019.021,023
0.1 uF ceramic disc
026
0 22 uF. 50 V
027
1 uF, 10 V tantalum
018
4.7 uF. 10 V tantalum
05, 013. 025
10 uF. 10 V tantalum
02
'Selected at test
Diodes
D1-D4
1N414S
Displays
11 16
DL-704
Transistors
Q1
MPF-102
Q3-Q6
2N2222
Q2
2N2369
Resistors (all V^-Watt)
R15'R21
120 Ohms
R2
150 Ohms
R8
220 Ohms
R22R35
390 Ohms
R9, RIO, R14
470 Ohms
R1,R3
6S0 Ohms
R7, R12, RT3
4.7k Ohms
R11
15k Ohms
R4
47k Ohms
R5
100k Ohms
R6
1.8 megohms
Switches
S3
SPST
S2
SPOT
SI
DPDT
ICs
U11
11090
U1,U8
7400
U12. U13
74LS00
ug
7420
U10
7473
U2'U7, U16
7490
U14
74LS90
U18
740925
uig
7805
U15, U17
9366
CrystaT
Y1
1 MHz. 0.001% toleran
30 pF parallel resonan
PC boards
L01
Clock and timing
LC2
Counter
LC3
Display
Miscellaneous
Archer #270253 (Radio
Shack)
Cabinet
31/4" X Vm
II
Quantity
1
1
1
8
9
1
1
1
3
1
4
6
t
4
1
7
1
1
14
3
2
3
1
1
1
1
1
1
1
1
2
2
1
1
7
1
1
1
2
1
1
1
F1
RG-174
BNC panel connector
Red plastic window
Test lead (BNC- alligator clips)
Power cord and connector
Strain relief
14-pin DIP sockets
16-pin DIP sockets
#4 hardware
Fuse and holder (1 Amp)
•02 (silver mica) may be used if CI is not suffi-
cieni to calibrate the crystal; otherwise it should
be omitted (approximate value is 60 pF).
1
18"
2
1
1
1
1
20
4
assorted
1
109
— The Full Spectrum of VHF
SCR 1000 - Standard oi Comparison
In Repeaters - Now Hvailable with Hutopatch
- and Many Other Options I
7iJonU(
The SCR1000/SCAP Combination
A A/ew
Dimension in Autopatch Repeater Performance
2M & 22011/IHi
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autopatch repeater on the air! The SCR1000/SCAP is a
fully self-contained .iO watt repeater with built-in
autopatch and land line control. You simply plug in
the phone line, hook up the duplexer, and you're on
the air! The usual months of problems are eliminated!
The SCRIOno/SCAP has been meticulously eni^ineered
to provide the smoothest performing patch together
with a positive land line control of the repeater. Just
look at all these features:
yeatu^tcd:
• Normal patch, or secure "reverse patch
• 3 digit antt4alsing access — single digit dis<
connect
m 3 digit on-off control of repeater transmitter
• 4 sec. time limit on access
Built-in adjustable time-oyt function — patch
shuts down in 30-90 sec. If no carrier is received
Wide range AGO on audio input and output
User can mute phone iine audio simply by key-
ing his mic button — prevents embarrassing
language from being repeated
Patch access and repeater control — either
over the aW or over the land line
The SCR 1000/SCAP is a complete Autopatch Repeater — fully assembled, set-up and checked-
out in our lab. As with all Spec Comm products, all workmanship and components are of the very
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in A.S.A.PJ
1 80 Day Warranty
SPECTRUM
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110
/FM Repeater Equipment —
The SCR 1000 **DrBam Machine** Sysiem is Continually
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Recent Improvements
D New, More stable, Mow*nofSe' transmitter exciter
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n New, great ty expanded memory CW IDer. (Up to 4 dif-
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D Improved Power Supply long-term rellabifity.
SCR1000 System Options
D Full Autopatch, *Reverse-PatchVRptr. landline control.
D TouctitoneTM Control of various rptr, functions, (eg,
Rptr. or '*PL" ON/OFF, Hl/LO Pwr., etc)
D "PL"; Multi-Freq.; Hl/LO Pwr.; 10 Pole Xtal Fitr,; Up to 4
IDs; Timer Reset Tone; TX Xtal Oven.
a 60^70 Wt. Transmitter
D Duplexers, Cable, Antennas^ Cabinets, etc. Please in-
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D We feel the SCR1000 \s simply the finest repealer available. It is often compared to other (lesser featured] units selling for 3X the price! Thrs 30
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Supply, CW IDer, full metertng & lighted status indicator/control push-buttons, crystals, local mic^ etc. Also provided are jacks for Emergency
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Q The Spec Comm Kepeater System a sound long-term investment — for those who demand the finestl An excellent value at $1150.00.
[$106S.OO w/o Preselector,] Available only by direct factory order.
SPEC COMM REPEATER BOARDS, SUB-ASSEMBLIES & ACCESSORIES
SCR 100
BOARD
All eqmpment assembled & testad. For 2IVI Se 220 MHz,
SCTtIO BOARD
SCR100 Fl«Ciai¥«r Board
• Wide dynamic rarige! Reduces overload,
'ds««na«'. and IM.
• S^ns 03 uV/2a dS Qt typ.
• Sel -6dB 0 2 6S KHz. -SOdB • ±30KHi.
(*110dB */opt- 6 Pole Fllr.) 10 Pole Fltr Avail
• S Meter' Output
Eic audio quality! Fasi squeJch! S125^00 w/xtal.
8 Pole FItr. (Highly recom mended J $15.00
SCR 100 Receiver Assembly
m 3GR100 maunted in shielded housinQ
• Same as used on SCR 1 DOG
• Completely asmbld. w/F.T. cape. S0239 conn.,
AF QAm POT, etc. 1195,00
SCAP Au1o|i«lch Boird
• Provides ail basic aiutopatcn fuTvctions
• S«« reaiur«s on opposite page. S23Su00
RPCM Boini
• U6«d w/SCAP board lo provide "Reverse Patch^
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« Inciucfes land lini "answofing" circuitry. S79.99
WP041 Duplexer
• Superior Band Pa as/ Band Reject deslgri
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• Bttremely easy !o adfust
• -93dB typ. isolation £495.00 \fuUi ckd^ out
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FL-Q Hcvt. Frofit'End Preselector
6 section f titer witt> FET preamp.
Provides trefivendous refect ion of "out^of-band"
3ign.als wtouX the usual lossi
EKtremely hetpfut at s^es with many nearby
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Ga^n: apx. 10 dB
Seleclivity: -20 dB @ ±Z0 MHsi; -60 dB @
± e MHz ayp-}
$85.00
TRA-1 TIfrwf Reeet Annunciator Soird
• Puts out a torw '"beep ' on rptr. xmir. apx, 1 sec.
aflef fcvd. signal drops — thus alloinrlng timo
lof breakers
• Resets rplr. Ume-out tlmv when tone is emitted
9 Adjustable time de^ay and tone duration
• Used with CTC100 and I D1 00/250
• $20.95 (Add S/fflOO for Inst, & ck. out in
SGR1000)
CTC100 COR/Tlmar/Con(roi Board
• Complete CQR circuitry
• Carreer Hafig' & TO Timers
« Remote itmtr. OhWOFF control
m ProvistOf) for panel control switches $. Lamps
• 100% SoIkJ Slate CMOS logic
• Many other teat y res 53500
tD2S0 CW ID & Audio Mixer Board
• Adiustable ID lOf>e, speed, level, hmmg cycle
• 4 Irtput AF Mixer & Local Mic amp.
• COR Input & xmtr. hold circuits.
• CMOS logic; PROM memory— 250 blt«/€hafi.
• Up to 4 Cihm^til ID channels^
« Many other teitur«a. Programmed S€500
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• Local MtC: $18.95
SCT 110 XmtrfExcfrar Board
for 10 Wts. Output
infintie vswR proor
True FM for exc. audio quality
New Design — specifically Tor continuous rptr,
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Very low m "while noise"
Spurious -70dB
With .0005% Jttal. 1 135.00
BA-IC 30 Wt. Amp board & Heat Sink. 3 sec. LPF
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SCTIIO Tnnimlt1«r A«s«mbfy
• SCTllO mounted in shielded housirig
m S«me as us«d on SCRiQOO
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• 7 Of >0 Wt. unit S199.95. Add $©800 for 30 Wl.
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COMMUNICA TIONS.
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TTC100 TOUCH TONE™
COMTROL BOARD
TTC100 Touchlone^M Control Board
»3 digit ON. 3 digll OFF control of 9 Single
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eacti) «ith 1 digit ^each) OFF,
^Can be used to pull In a relay, trlggef logic, etc.
Typically used for F^ir. ON/OFF, Hl/LO Pwr^
P.L ON/OFF. etc.
I Stable, am I -falsing design.
$85.00 ($110,00 Insl, & citd- out m SCRIOOOO)
Send for Data Sheets!
JHandL — $3.50. PA msicfents add 6% tax)
^ Reader Servtce—see p^ge 3?5.
tit
W2NSD/1
NEVER SAY DIE
editorial by Wayne Green
ffow page 4
Well, ARM A was in serious
need of some activity which
would be of benefit to the entire
ham industry as a way of attract-
ing members. They were forined
to fight the linear amplifier
nonsense, but this was of in-
terest only to a few manufac-
turers, so ARMA meetings were
small ;. . very smalL
Both as a rallying effort for
ARMA and as a response to the
threat of the 44 African nation
black bloc which couid well
eliminate ait amateur alloca-
tions at WARC, I convinced
ARMA to try to support a mis-
sion to Africa, ARMA voted
overwhelmingly to support the
plan.
ARMA decided to put the job
of writing the letter asking for
support from both the industry
and individual amateurs in the
hands of two chaps from Ham
Radio magazine. 1 expressed
concern over this, for the
ARRUHf? connection is hardly
any secret. ARMA members
seemed to feel that this was
too important a matter to suffer
any political shenanigans.
Unfortunalefy, it turned out
that ) was right again. Not only
did the letter ne^^er gel written
(that was four months ago), but
the promised piece in HR
Reports asking for support also
did not appear. HR Reports did
print a short put-down of the
idea and then later resorted to
outright lies to try to back this
up, saying that the ARMA direc-
tors had voted against the
African plan.
Should we only lose a smatt
part of our allocations, I hope
that indignation will run high
enough so amateurs will get
busy and get some better ARRL
directors elected and have
them get an executive search
firm to find someone with
business background and a
history of honesty to manage
the League. Having this $5
million empire in the hands of
Incompetents is a crime which
could very possibly lose us the
whole ball of wax.
If we lose everything, then
the problem will have been
neatly solved. No amateur
radio, no League, and some
people will be on welfare at the
general public expense instead
of ours.
While I am writing about the
League, I wonder il you knew
that their Hartford convention
last year ended up with a profit
which went into the ARRL kitty.
Some $3,000, I understand.
Would this have been better in-
vested in lower admission
charges which might have en-
couraged younger hams to
come to the show?
There has been some
criticism ol the board action to
authorize the short-term bor-
rowing of about a quarter
million dollars to help pay the
day4o^day League expenses.
Despite record income, the
ARRL has been racking up
record losses. Instead of figur-
ing out how to make their
books better so they will sell
more, they are responding by
laying off people. Indeed, many
of their best people have
recently jumped ship ,,,
Dunkeriy, the Whites, McCoy,
etc. Laying off people will only
empty some of those new and
expensive offices they just
built and are now trying to pay
for.
Amateur radio is growing at a
high rate and we see this in 73
In an increase in both subscrip-
tions and advertising. The re-
cent issues have been the larg-
est In our history and we have
been doing everything we can
to get more people to work
here, while ARRL has been fir-
ing their people.
We need people to work in
our book department to prepare
books for publication. Every
lime we gel someone trained
for this, the 73 staff grabs them
to work on the magazine, ieav-
ing us shorthanded for book
preparation again. We need
people interested tn marketing,
advertising, drafting^ a good
technician to help test ham
gear layout and pasteup peo-
ple, plus a lot more help with
our microcomputer magazine
and software plans. We are
nearing a staff of 100 now and
are projecting 200 by late next
year and 300 in 1980,
If amateur radio should get
killed, 73 would have to become
an experimenter magazine and
would undoubtedly shrink a lot.
We don't know what the possi-
bilities are for 180 kHz low-
power communications ... or
9>EflL« fDRKTORY
lontAiifl CA
We earry the f&licfwing: !COM, Mid1«nd, Am-
com. DenTron. kl M. Sw^an, Drikc, Tcii-Tcc,
WOion, SST. MH, Hy-Gain. Lmm, Njc
Vitins* B^W, lUdi kilowaii, CiiUi Cmtu
Moslcy, Big Sifital, Hpo. etc, Full Senncc
Store foitiBiiM Brrtroaira, SdZi Sinn Air.«
FcHiiM* Ch 9UJ5, »2'T7IO.
^sinia Clara CA
Bay area'^5 ncwesl Amaicur Radio siorr, New Si
used Amateur Radio ^It* & service, We
reature Kcnwfiod. I COM, Wilson, Yaesu,
Aiks. Ten 'Tec & many more. Shuvrr Updio,
3S5(I^ l4>chfitvir Avtnuf, Sanla Clin C A
950Sl.247-4Ua,
Denver CO
lier'i pw»dise! Electronic and
components for computer poipfet
■odfo pfOfle, ^ims,, robot biuJd«rf, em-
prHirtenters. Opcfn u\ days a w«ek, GAlewtr
e]«clr0Bk» CwF.t aJ9 W, 44th Avf *., Dts^cf
CO imHf 458'5444.
New Castle DE
Pflul WA3QFX, Rob WA3QLS— Servittg
amateuri^ In iOUlK^rn New Jersey. Delaware,
and Maryland wiihthtlarftcsl stock of amattur
equipment and acces^o^rici in Delaware.
Drlawu^ Amilrur ^iippl>. 11 Mtadaw Road,
Boise ID
Alliance, Amcom, OR, Cuiticrafl. Dentron,
Edgixoiti, ICOM. Huidef. KDK. MfJ. NPC,
SYE, SST, Toi-Tcc, WiUon tiutom 0(s>
iroaiet, I2m Ibvadm}. B«bc ID Uim, Bob
Tell ihem you saw
iheir name in 73
Preston ll>
Ron WB7BYZ. has ihe Utfgcit Slock of
Anmteur Goir in the luiermutintiun Wesi aiid
Ehe ilcsl Prtcfes. CaU me for all your ham needs.
Ko!iK Ulj«(ribuljiig. 7» So. Slat«, Preslon IJ>
BtooEnington IL
Retail— « hoi csak dmributor for Rohn
TowCTi — anirnnas b>' Cuih Craft, Ant«inft
Spedaliits, KLM» WiUon, Hi^-Gain.
Traiiiceivrfi b:i Tempo. Refcnc?. Wilson,
Aincom. AJw business and mArtneridios. HiB
Hii^Q. I5«9 G,E. MA.. Bioomiagioa tl 61101,
Terre Haute IN
Your hawi hcadi^uanen lociaicd in ihe hcait of
the midwest Hcwsier FJ»:(rcinlc^, Inc., 4^B
Meadow;^ ShoppinK C enipr, P. (J. Ikm lOttl,
Tcrit Hauie IN 47801. 238-1456.
Littleton MA
Tlie htm ii0tt 0( N.£. you can tdy ^n. Km-
wDod, tCOM^ Wibori. Y a<nu /DenTron, KLM
ainpi, &A:W nriithcs A vk.aitmcten. %1ii:ukr
radar detf!t:iDr», Bcamai , ftrfcfK^. antennas bv
Lafwn, WiImth^ Hiisikr, GAM. TEL -COM
Irc, Comnunicfttions St URimaks, 675 (»mil
m. Hu 119. liitlnofi MA 01460. 4««-JMU0.
Laurel MD
We MOck Drake, Tc»-T*c, Wilson, iCOM»
DetiTTxni, Tempo, Hy-Gain, MicUsnd, Motley,
Huukr. 40-paE)e ham zntksg available fof
Si. 00 (refuiHlable wiih lii piirdiasci— nfrwe
(m cash quote' tht C»inm Onirt. Ik*^
laurH Ptaia. Itir, 19t, Uard MD 201110,
7924MW.
St. Louis MO
Experimenter*! paradise! Bleetronic and
mechanical componenls for computer people,
audio peopk, hams^ robot builden^, oi-^
perimcnicrs. Open tbl dftyi a w^ck, Cairwaf
BcclronlB Corp., ttl3-25 Page BJ^d.. SI,
iMii MO tiJUe, 4174116,
Camden NJ
X'-Band i& othieT frfquencifsl Mkrowave
Compoficnt^ & E^uipm^tnt. Laboraiory Grade
Tdt Insirumcnts, Po^tr Supplii^H lOOO** m
sloct ai ail times, SUV & SELL all popular
makes— HP, OR. TXR- ESL Sorcnwn, Singer.
«Lc. t..«lrofiic Research Labi, 1423 Ferr^ Ave,
Camden MJ Uil04, 54M200.
Syracuse NY
We DcaL We Tiade. Wc Difcounl. Wc Pteaset
Yaesu. Kcn*ood, Drake, ICOM. Ten T«,
Swan, DenTron, Midland, Cu;^ Crafi, KLM^
H^'Qain, «c. Compl^ne 2-*av fcniee tlwp!
Hint-bftac ltadK> >idi^- Slirro Repair Sbnpl
J30fr Fjie m*4. Iji«l, ^i^vracwe N\ 11114^
Sj^racuM-RuniF-LitiCii N%'
Featunng: Yaesu. tCOM^ Drake. Alias, Dot-
Tron, Ten-Tec, Swan* Tempo, KLM, Hy-
Gain* Motley « Wiluin. Lancn, Midland
ScKMbwesi Te^hniol Producls. You won^t be
dj&apppjnied with equipmcni/icrvice. Rails
Wnrld. Onrlda rQunt; Airport -Ttrmiflit
Biuldinfc. Ornkanf M 13424. 357-2«Il,
Soufterton PA
Tired of lookinfi ai ads 111 Come and try our
nevi and u^cd equipment yourseir^-periional
udvice rrom our staffs 60 years combined hatn
experience. FJeeiriink" Emehange. 13* N. Main
^., Snudrrinn PA 1JI964. 72J-liZ00.
Port Afigeies WA
Mobile R¥] ^hicliiin^ ror eiimmation of ipli-
tiofi and akctnaiof noise.. BofidUli strafH.
CoCTponenit for *'dd-ii-yourwtr* pfajfct*.
pftnty of fr^ ndvtce WMm F.n^imt^mt. *30
Marine Drit'C* Porl Aafelci >A A 4IJ42»
457-(19iM.
DEALERS
I^DJir cornpttny name ttfid message mn amtttitt
as many ax 2S warttxfor as Uttk m $f^0 yearfy
fprepufdf. Iff St$ ptr mtntfh iprtpaid
t/uarteftyj. Vii mtmitw of mail nr huxinta or
«r/**a caiie pttmititd. Dirrclory trxt ^ad pcy-
m^tt must rtwch ut #5 <ipjj in ititvtmtt */
puhitcaiion. Fur mimple, advfrfhmin for the
March jiu/e must be in our fumdt by Jtinuary
lifh, \fmt fv 7} Vtagazt/ff^ f^^bmi$it % H
ff34Si, 4 IT Vr Aline Cmttm
112
what might be developed In
underground communications.
Would amateurs shift to 11
meters and the HF band? The
CB repeater band would get a
good workout, for sure.
These are bad thoughts, so
in general I agree with the
ARRL leaders and their ap-
proach ... "they can'i kiil
amateur radio!" Keep thinking
those happy thoughts.
With or without an amateur
radio magazine, our microcom-
puter magazine wHI be continu-
ing to grow. Plus, we have two
more magazines in the works
and the instant Software proj-
ect, so we will be growing in
size even H amateur radio does
disappear. IHaving been an avid
ham for some 40 years, I'll sure
hate to lose It. It's been a big
pari of my life.
During the las! 40 years, Tve
talked with amateurs in well
over 30€ countries and visited
them in almost 100. I've had fun
with RTTY, NFM, SSTV, SSB.
moonbounce, OSCAR* micro-
waves, repeaters, and a whole
lot of rag chewing. I'll never
forget the pileups I ran into
from many rare spots or the
thrill of pioneering new modes,
(f things should go against
uSt how soon would the axe
fall? As near as I can figure,
even if we lost everything, ft
would take several years before
we would actually be put off the
air. We would still get a lot of
action from our new rigs . . •
and some of the newest stuff is
fantastic. We would not be out
of business until our govern-
ment ratified the ITU agree-
ment. With no lobby in Wash-
ington to express our concern
over this matter. Congress
might not waste too much lime,
particularly if the EIA were in
there pushing against us. Yet
even when Congress acts
quickly, it can take years.
Can the U.S. simply drop out
of the ITU? If amateurs lose fre-
quencies, you can be sure that
commercial and military in-
terests will also lose them
whoJesaie, so we won*t be the
only group burnt. How practical
is (t to consider trying to go it
alone and not have to toady to
the African countries? Well,
we've been having the same
problem with the U.N. and we
haven't dropped out of that yet,
no matter how miserable they
make it. The ITU is a branch of
the U.N., by the way. It seems
unlikely that we would pull out,
no matter how revolting the
consequences.
So far Tve had nothing but
comments of agreement on my
evaluation of the situation, I
know the ARRL disagrees, but
no one in the ARRL has come
up with any good reasons for
disagreeing. Others claim that I
have been guilty of understat-
ing the seriousness of the
situation. If anyone has any
words of cheer, the pages of 73
are wide open. Let's know It if
you have any data which
changes the picture. We really
need a change.
WHAT ABOUT NEXT YEAR?
While December is best
known for offering us Christ-
mas, a holiday to which I am
not partial, it aiso inciudes, at
no extra cost. Hew Year's Eve*
Whee,
Since a birthday gets only a
small celebration, It is not quite
as traumatic as the New Year,
where it is made ciear that
everything and everybody is
now a year older. It is a time for
introspection. Let's mull over
amateur radio, putting the last
year into perspective and see-
ing what we have going for us
for 1979.
My recent experiences with
the reiativeiy simple 10.5-GH2
rigs is indicative of some of the
fun that lies in store for the
adventurous. Bandwidth is not
a problem at these frequencies^
so we can use such microwave
links for teievision, data
transfer, or whatever we want
to cook up. Of course, the sad
fact that we have iosl this in-
credible band for satellite use
through blundering at Geneva
is something we will have to
live with as long as we have
amateur radio, it didn't seem
quite as important when there
was nothing much availabte in
equipment to use on these
bands, and therefore they were
of Interest only to a tiny group
of hams with machine shops
and incredible patience. Now,
with relatively simple and inex-
pensive equipment coming
available, we will begin to fee^
the pinch and begin to really
understand what has been lost
. . . forever.
The sunspots have been
coming back In spurts, Just as
our propagation editor said
they would. Incidentally,
Nelson was the only profes-
sional in this field to make such
a prediction, so I'm sure he's
sitting back with a smug look
Continued on page 246
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113
Rob&rt VillasmgQ K5GN2
Z09 Irvington
San Antonio TX 7B2Q9
Confessions of a Stripper
confirmed junkor tells all
Which are you? The
**iunkee'* Is a collec-
tor of odds and ends, an
impulse buyer, a pack rat —
don't throw it away, you
might be able to use it some-
time. The "junkor" strips
everything now and gets rid
of the excess - if he can't use
it, he throws it away - he can
always get another one, the
junk yard or surplus house is
full of them.
If you are an experiment'
er, you probably fit into one
of the categories* Articles
about stripping surplus equip-
ment are commonplace
among the old issues of many
magazines, articles on how to
strip a TV set and get usable
parts for the do-it-yourself
projects, or stripping par-
ticutar Gl units ^sily ac-
quired to obtain the neces-
sary parts for a specific
project. But every article
assumes that you know what
to do with the residue of the
stripped unit after the project
is complete^ or that parts
desired are removed. It's
assumed that the '*junk" will
be thrown away. Don't do li.
You can save yourself a little
cash and also do your thing
for ecology.
Stripping or junking is, in
realityp an art form. I have
seen salvage metal buyers
who can handle a hammer
and chisel like an experienced
sculptor. The required re-
moval of a frozen nut or bolt
to separate a valuable piece of
equipmenl from an inde-
scribable or unworthy piece
of metal requires talent if
damage rs to be negligible. In
the first place^ a professional
cannot spend a lot of time in
dismantling equipment. His
time and profit margin isn't
that much. His methods may
be crude, bui^ when it counts,
he has the delicate touch of
an artist
When removing the parts
you desire for the project you
have in mind, go one step
further. Completely strip
down the unit at the same
time. This will keep storage
problems from arising.
Lay out the tools you will
need and have a seat. There
are many ways to keep parts
separated. It depends on how
much stripping you intend to
do. The cheap way is to
gather a bunch of milk car-
tons. Cut them in half and
wash them out. Use as many
as you need,
A tool caddy is advisable,
loaded with every tool imag*
inable. Stay away from un*
soldering items when strip-
ping. Save those until later
when you are ready to use
them. Cut them out with a
pair of large diagonal pliers, A
great time-saver is the use of
nul*driversp spintites, etc.
These do not preclude ihe use
of a socket set at times, but
normally they wilt suffice in
most cases when the nuts are
securing terminal strips and/
or transformers^ tube sockets,
and other nut-and-bolt
secured Items. Allen wrenches
are a must for knobs and gear
drives where needed. Nothing
is more aggravating than
being midway into a stripping
project and finding a gear
that is preventing the removal
of an entire mechanism. All
that's required is the correct
Allen wrench ... and you
don't have it.
If the equipment being
stripped is small, then the
tool complement can follow
in order, Electronic equip-
ment lools used for disman-
tling and repairing equipment
may be all that's necessary. If
the equipment h large, addi-
tional lools may be required.
If the item is a piece de-
signed strictly for military
application, then there will be
some specially designed
screws, nuts, and bolts that
should be removed with a
hammer and chisel. Leave
them until last Even if you
have the special tool, don't
waste your lime. You
wouldn't want to use them in
a project anyway-
Wiring harnesses do not
serve any purpose unless you
need hookup wire. Removing
114
the entire harness at one time
is sometimes easier than re-
moving and disconnecting
each item as it is stripped. If
the terminal strips and asso-
ciated plugs are not wanted,
then leave them connected
and remove the entire wiring
assembly by unscrewing, un-
bolting, and cutting. When
this is out of the way, all
other parts are easily acces-
sible, and dismantling is much
easier,
A reminder here about the
removal of transformers:
Trace the wiring and mark
the connections before re-
moving. Many will follow the
standard color code of black
for primary, red for second-
ary high voltage, red and
yellow for center tap, and
green for filament, but don't
count on it Some artistic
devils can get hold of the
design and color leads to look
like modern arL Trace the
wiring just to be sure before
disconnecting the trans-
former. The same thing
applies to any item that has
more than two leads and
depends on any type of color
code for identification.
There are always some
limitations each do-it-yourself
technician places upon him-
self It may be coil winding or
some other technical item
that requires special equip-
ment or a tot of time to build
and is easily acquired for a
small sum of money at the
local parts house. Another
example is tube sockets. The
common seven- and nine-pin
sockets can be reused if you
are willing to take the time to
clean the individual pins after
removal from the chassis
being stripped
The most usable items that
you can remove in quantity
will be the resistors and ca-
pacitors. You will never have
enough of these items. The
more you get, the more you
find you will need. Removal
of these items can be done
rather speedily.
Where tube sockets and
terminal strips are not impor-
tant, a fast method of re-
moval is to cut the tabs of the
terminal strips and sockets
The junkee who sai^s e wry thing needs a place to put it If you ^e an organ iied junkee, pigeon
ho/eSf like these, are ideaL If not, it may take a month to find a particular item.
instead of the resistor wires
and capacitors. You can
remove the solder and small
piece of connection later
This also allows for further
and faster stripping.
The junkee has arrived at
his destination. All reusable
parts have been removed and
all that remains is a bunch of
wire and assorted metal
chassis bits and pieces. The
junker's turn is next. The
funkor will take the same
piece of equipment and spend
just a few minutes and
accomplish the same thing.
He will get his desired part
and either throw the rest
away or store it for later use,
or strip it to the point where
a salvage metal buyer wi!I
accept it There are many
hobbyists who enjoy strip-
ping as much as they do
building. If that is your forte,
then make it pay.
You must acquire a most
important toot to keep with
you at all times — a magnet
This will aid you no matter
where you beg, borrow, buy,
or steal your material. Separa*
tion of the different types of
metal (copper, iron, steel,
stainless steel, bronze, etc.) is
a must Also, to make it
worthwhile, don't attempt to
sell the metals unti! you have
a sizable amount Of course,
it depends on the type of
metat Where ten pounds of
clean copper wire may bring
you four dollars, the same ten
pounds of aluminum may
bring one dollar and sixty
cents ($1.60) at fifteen cents
per pound. The prices may
fluctuate from day to day,
but usually not more than a
few cents a pound, although
prices for clean copper in past
years has risen to over a
dollar a pound and fallen
back to as low as thirty cents
a pound.
Clean metals will bring as
much as MO percent more
than what are known as
**d!rty meuls." Dirty metals
are those that still have
screws, bolls, rubber, weather
stripping, or other materials
which are still attached
For speed, the hammer-
and-chisel technique is used.
The simplest way is to take
the chisel and hold it with a
pair of pliers. This eliminates
split fingers, but it does not
eliminate the tiny slivers of
metal that occasionally fly
from the head of the chisel.
Gloves and a pair of safety
goggles^ if you don't wear
glasses, should be used if you
intend to do much chiseling.
When you have everything
removed^ check the metal
with your liiile magnet. Any-
thing it will stick to is iron
and should be removed. This
Is the main purpose of the
magnet. Of course, the mag-
net will not indicate the
presence of brass or copper
which should also be separ-
ated. Yd low- colored metal
will indicate brass, while the
reddish varieties are more
likely copper. Stainless steel
and lead also bring a nice
scrap price.
You can throw away the
lube sockets, crushed coils*
resistors and capacitors not
saved, and knobs (unless they
have brass inserts). A smart
blow from a hammer will
crack away the outer plastic
covering of the knob and
leave a clean piece of brass-
Don't expect much from
your iron; that wilt be on the
low end of the pay scale {two
or three cents a pound).
When you have accumulated
thirty or forty pounds or
more of copper, brass,
aluminum^ etc, you might be
surprised at the price it will
bring. Remember to keep it
separated and free of iron.
One last reminder: Wire
115
must be completely clean of
ail insulation and attach-
ments, including plugs, clips,
brackets, etc. This, of course,
is your highest paying metal,
so extra care should be taken.
In most states, the method of
burning the insulation off the
wire is forbidden due to the
pollutants released by some
electronic insulation, al-
though this does not stop
many illegal smelter opera-
tions and backyard burners.
The backyard burners (bar-
becue pits) usually get away
with ft because of the small
amount cleaned (ten to
fifteen pounds) at a time.
The junkor should be
aware of the copper content
of television yokes, motors,
and, last but not least, trans-
formers. Average trans-
formers with an open core
winding will contain between
thirteen and eighteen percent
of the total weight in copper.
Again, the easiest method of
stripping a transformer is to
burn it If it*s an enclosed
transformer, remove the
outer cover and throw it in
the fire, if regulations permit.
One alternative is to remove
the wire by hand. This can be
a difficult and tjme-consunrv
ing chore if it is an iron-core
transformer with inserts
shaped like the letter W. The
easiest method is to saw
through the inserts and slip
them out, leaving the wire to
be unraveled by hand.
There are many other
ways to accomplish the same
stripping procedures dis-
cussed in the preceding para-
graphs, but whatever method
you discover that's easiest for
you to use, do it. Not only
will you pocket a little extra
cash, but a lot of that old
metal will find its way back
into circulation, and someday
your efforts may be remem-
bered as the only thing that
saved the beer can.
May you chisel your way
to glory. ■
:ju iroon^ If.fi' t •: ver ' r>ro jfr
1^' ."o
1 *
t e. 1 1 i\\ a h Pi.] v.. 3.x 3 h e ::f h o a
fmmpage 102
everyone give their QTH as well
as their callsign. Vm sure most
of the old-timers feel the same
way,
Russell A, Gariin WSUKA
Albuquerque NM
MORE M1C0DER MODS
Re the MicoderTM articles in
the July, 1978 (page 90 by
K3MPJ), and August, 1978
(page 166 by W4CUG)p issues of
Getting rid of the 555 timers
for tone generation is easier
than building a PC board and
buying all the parts, that is,
unless you have a well -stocked
junk box. IHeath has a kit to
make the Mlcoder into a
Micoder IL It is riot very expen-
sive and includes all the parts,
it uses the Mosfek chip and TV
color crystal.
Also, to get rid of the 9- volt
battery, which just doesn't last
very long at alL I did it a ifttle
more easHy than K3MPJ.
Unless they have changed the
coiled cord in later models, \\
contains an e>ctra black wire. It
is connected to ground al each
end with the shield. I used the
same zener setup that MPJ did,
except t put the zener and
resistor where the cord comes
into the radio and used the ex-
tra black wire for the power
conductor. There was no
change in the fme audio quality
of the Micoder or 2036. As a
side benefit, the Mrcoder is
somewhat lighter without the
battery.
I hope this will be of iotefest
to others who might want to
make these modifications.
Oscar A. Hayt III K5UBS
Daltas TX
JAPANESE JACKPOT
]
Japanese folklore says that
there is a jackpot day in each
month. The day I find 73
Magazine in the mail box is the
day for me,
I especially Nked your article
"Radio Row Revfsited" in the
past August issue. I would like
to make an addition to Brad^s
statement that **a large portion
of the gear on display here is
aimed at the lucrative
Japanese Novice market: ten
Watts maximum, phone onfy,
80, 40, 15. and 10 meters and
VHF."
The Japanese version of the
FCC has regulations applh
cable to four different amateur
radio licenses.
1. Novice: Bands and modes
same as the regulations.
2. Telegraph class: Same as
Itovice plus CW.
3. Second class: 3-500Z x 2^
maximum.
4. First class: Henry 4K*Ultra,
and up.
I have never seen a ten-Walt
rig, except at a ham shop
display, and in my own shack
when I was a Novice.
Mitch H. Ono JF3JKK
Otsu City, Japan
WONDERFUL RESPONSE
About a year ago our club
asked you for a donation for our
first club raffle. The response
was wonderful and the raffle
became a great success. Our
goal was modest: $200 lot the
treasury. We surpassed that
with your help.
As a club sponsored by the
Nassau County Department of
Parks and Recreation, we do
not charge any membership
dues or fees. The modest
treasury helps keep us on the
air, and in postage. We are not
asking for a hand again, but we
may do so in the future.
Please pass on the word that
students are always welcome
in our Novice and GenefaiiAd'
vanced classes each Monday
at 7:30 pm.
Gene Blanck
East Meadow NY
Corrections
It was called to my attention
that one reader thought that
there was the possibility of eye
damage from the use of the In-
stant Engraving system de-
scribed in the July issue (Let-
ters. September, 1978, p. 127).
He cites the tact that carbon
arc lights are used to generate
ultraviolet radiation for use In
exposing photosensitive mate-
rials. Of course, some form of
eye protection Is to be used
under those conditions. The
key words are carbon arc.
Please note the third column
on page 59 (July, 1978), ", . . the
voltage should be kept below
the point where an arc can be
struck and maintained." Photo
0 shows the rod glowing from
simple i2r tieating, not the
veritabitt^ inferno contained in
an arc. the light given off dur*
ing the engraving process
should be no more or less harm*
ful than^ that of any other in-
candescent light of similar
light value. As in any incandes-
cent tight source, a con-
siderable amount of energy is
dissipated In the form of heat,
with only a smalt portion used
to generate visibie or invisible
radiation,
I regret any confusion that
there may have been concern-
ing the above point,
Ev«rt Frultman W7RXV
Phoenix AZ
Please note a correction to
my article 'Triple Threat/*
which appeared in your Oc-
tober Issue. On page 1 33, line 2,
column 2 should read ''leled
phono or phono".
Ralph E Delligattl K30MY
Qalthersburg MD
Ham Help.
I would like to know if anyone
knows of a commercially run
school which a person can at-
tend in order to learn how to ob-
tain an amateur radio license,
Carl M, Sullivan
RR 24, Box 383
Terre Haute IN 47802
I need a schematic and/or
manual for the Harris-lnterdala
COPE 1035 SelectriC'based ter-
minal. I will pay for photocopy
and shipping.
Jeff Duntemann WB0MQY
6208 N, Campbell Ave,
Chicago IL 60659
lie
'k\
■CO
N.
FAA
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4C
341
BO
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ENRY RADIO'S
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inany amateurs ^'^ulri hfl gff'^^fift^ W^l^ less 4: a vv]
could still have ttie &am,e high qm de-oendi
th0 IKD'5 ftilftUs tHa4 nMd baa.
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clear signals, the IKD-S will give you iust about ©veryihing
you want . . . and withoui sacrificing quality^
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Tuned Feeders
and Other Good Stuff
who needs coax?
AS you know, other
things being equal,
the success of your
amateur radio station
depends upon the quality
of its antennas. Is your
antenna a coax-fed dipole?
If so, why? Is it because it is
the easiest kind of antenna
to put up and get on the air
with? Is it because it can be
brought into the house
through one small hole? Is
it because other kinds of
:• *f
ff
Vertical lepp"' aritenna for 20 meter CW.
antennas seem compli-
cated and difficult to
understand?^
From on-the-air descrip-
tions of antennas, one gets
the impression that most
amateurs feed their anten-
nas with coax. This was not
always so. Before coax ex-
isted, amateur operators
designed and built ex-
cellent antennas using
open-wire tuned feeders.
Some antennas used no
feeders at all.
The purpose of this arti-
cle is to present some
''antenna axioms" along
with some basic antenna
theory and to explain how
to use these ideas to build
effective antennas that are
not fed with coax. (Coax is
used only between the
transmitter and the anten-
na tuner.) Building and ex-
perimenting with antennas
is fun and good experience.
Antenna Axioms
1. The antenna system
should be resonant at the
frequency being used.
2. The rf from the
transmitter must be effec-
tively put into the antenna.
3. "There is no sub-
stitute for height." The
higher the antenna, the bet-
ter. The high-current part
[or parts) of the antenna
should be as high as pos-
sible.
4. Other things being
equal, full-length antennas
work better than do shorter
antennas that have been
made ''electrically longer"
by means of "loading
coils.''
5. Quarter-wavelength
vertical antennas use a
good ground or group of
quarter-wavelength radtals
for the other half of the
antenna. Radials buried in
the ground are often used.
The greater the number of
radials, the better the
antenna works. At easy-to-
attain heights, vertical
antennas have a lower
angle of radiation than do
horizontal antennas. This
makes them good for DX,
6. The transmitter's har-
monics should be pre-
vented from getting into
the antenna.
Basic Antenna Theory and
Applications
A half-wave resonant
antenna has high voltage rf
on its ends and high rf cur-
rent in its center. (See Fig.
1.) The antenna can be fed
rf voltage at one end, or it
can be fed rf current in its
center. (A half-wave anten-
na fed in its center by coax
is a current-fed antenna.)
An antenna can be voltage-
fed by bringing one end in-
to the shack and connect-
ing it to a parallel-tuned
^'antenna tank" tuner
118
Tuned doublet antenna 66 feef either side of center.
which is link-coupled to the
transmitter The tuner is
composed of a coil and
variable capacitor which
will tune to the frequency
of the transmitter. The
rotating plates of the
variable capacitor are con-
nected to ground. The
stator plates wilt be ''hot"
with rf voltage, and the end
of the antenna is con-
nected to the stator plates.
One side of a neon
tube is connected to the
antenna to indicate the
presence of rf voltage
when the coil is tuned to
resonance, (See Fig. 20 The
antenna shoutd go out
from the shack and be
strung up as high as pos-
sible, (The length of a reso-
nant half-wave antenna is
found bv applying the for-
mula: Length in feet =
468/frequency in mega-
hertz.) If the antenna
length is for one of the
lower frequency amateur
bands, it can be used on its
harmonics for the higher
frequency bands. (An
antenna 132 feet long, for
use on the 33 MHz band,
will also work on 7 MHz, 14
MHz, 21 MHz, and 28 MHz
by tuning the antenna
tuner to these higher fre-
quencies. Plug-in coils can
be used for the various
bands,)
An antenna may be cur-
rent-fed if the center of the
antenna is brought into the
shack. In this case, the coil
Antenna grounding switch on tuned doublet's feeders. The
switch is in place for use on the am
and variable capacitor are
connected in series with
each other and in series
with the rf "center ends" of
the antenna, (See Fig. 3.)
This kind of antenna can be
conveniently used if the
shack is on the second
floor of a house. One half
of the antenna can be ver-
tical and the other half of
the antenna can slant
down and out. (Two-by-
fours, or furring strips
screwed together with a
long bamboo fishpole on
top, make a good support
for a vertical wire.) This
kind of antenna illustrates
the principle of series tun-
ing for rf current. The end-
fed antenna utilizes the
principle of parallel tuning
for rf voltage.
When an endfed anten-
na is used on its harmonics,
provision can be made for
lengthening the antenna in-
---e
side the shack to make it
work better on the har-
monics.2
It is good to have your
antenna as high and in the
clear as possible. For this, a
means of feeding the rf to
the antenna through wires
is necessary. (See Axioms 2
and 3.) There are several
kinds of wire transmission
tines that can be used. The
most efficient transmission
line is the open-wire type.
(Efficient means with the
least loss per hundred feet
of line.) Next most efficient
is the transmitter-type
twinlead. After this are the
other kinds of twinlead (TV
twinlead). The least ef-
ficient transmission lines
are the small-diameter
coaxial cables such as the
RG-58/U and the RC-59/U.3
Before coax was avail-
able, zeppelin-type
("zepp") tuned feeders
were often used to take the
rf from the shack to the
RF. FROM
THANSMITTtR
i
fig. h Rf voltage and cur-
rent distribution of a half-
wave resonant antenna.
R.F. FROM TRANSMITTER
Fig. 2, Feeding rf voltage to the end of a resonant antenna
Iparallet'tuned coil to give rf voltage).
Fig. 3. Feeding rf current in-
to the center of a half-wave
resonant antenna (series
tuning for rf current).
119
*'Singie-ended'' antenna tank tuner for end fed (vohage)
antennas [switch for transmitter or receiver, etc.l
i f
antenna. The ' zepp
antenna consisted of a
resonant antenna that was
fed by an antenna that was
a hatf-wav^length long,
folded back on itself, and
fed rf current. In the case
of a dirigible or zeppe]in,
the antenna was sus-
pended below the air-
ship, as in Fig. 4. When
used in an amateur radio
station, the tuned feeders
go up from the shack to the
end of the antenna. (See
Fig. 12) Electrically, the
tuned feeders are an anten-
na folded back on itself,
and one end of the tuned
feedline is connected to
one end of the antenna.
The other end of the
feedtine is not connected
to anything, except, of
course, the insulators that
support it There is no rf
radiated from the tuned
feeders because the rf field
of one feeder cancels the rf
field of the other feeder.
The length of the zepp
antenna itself should be
5% longer than 468/f(mH2)
because of ''end effects/'^
The "tuned doublet" is
another type of antenna
that uses tuned feeders. 5
This antenna is better
balanced than the zepp
because both ends of the
tuned feeders are con-
nected to the antenna,
each to the same length of
wire. (See Fig. 5.) The tuned
doublet can be used on
harmonfcs of its f undamen*
tal length. Furthermore, it
has a gain of about 1,9 dB
at right angles to the anten-
na when it is tuned to its
second harmonic. The
antenna also has some
gain, as compared to a
dipole, when it is used on
higher harmonics at angles
less than 90 degrees from
the antenna. If the station
can have only one antenna,
a tuned doublet would be
an excellent allband anten-
na- Cut for the lowest fre-
quency band to be used, it
ANTENNA
Fig, 4. The original ''zepp'' antenna.
would be operated on its
harmonics for the higher
frequency bands.^ An ex-
cellent tuned doublet
antenna 66 feet either side
of 65-foot open-wire tuned
feeders was used in several
field day contests. It
worked well on 80, 40, 20,
and 15 meters. [It was not
tried on 10 meters, but
probably would have
worked there, also,^
Antenna Tuners
A tuned feeder antenna
system requires an antenna
tuner between the trans-
mitter and the tuned
feeders,^ The most simple
antenna tuner for balanced
tuned feeders consists of a
coil tuned by a split-stator
variable capacitor, link-
coupled to the output of
the transmitter. The
feeders are connected to
the stator plates of the
variable capacitor. (See
Fig, 6. J The coil and capaci-
tor should be of such
values as may be tuned
to the transmitter's fre-
quency, (Plug*in coils can
be used to change bands.)
This tuner works well if the
length of the antenna and
its feeders is such that the
ends of the feeders in the
shack should be fed rf
voltage. However, with
other feeder lengths,
variable capacitors must
be placed in series with the
feeders, and you have the
tuner of Fig. 7, Since tuned
feeders are of the same
length (balanced), the
series-variable capacitors
are ganged together and
tuned with one dial. (These
capacitors must be elec-
trically insulated from
each other when ganged.)
This tuner (with plug*in
coils for changing bands)
makes possible the use of
tuned feeders of practical-
ly any convenient length. A
neon tube connected to
one stator of the split-
stator variable capacitor
(or leaning against one or
both of them) helps in the
initial tune-up of the anten-
na system, A field strength
meter located not near
the antenna tuner should
be used, and the antenna
system tuned for the
greatest field strength in-
dication.
With this antenna tuner,
an swr meter connected
between the transmitter
and the antenna tuner may
show a rather high swr, but,
when the field strength
meter shows the highest
reading, the swr will be the
lowest The use of coax-fed
antennas and the limited
impedance output range of
many transmitters have
made amateurs worry
about swr, and nearly all
hams use swr meters. To
reduce the swr between
the transmitter and the
antenna tuner, a large
variable capacitor can be
added in series with the
primary coil of the tuner, ^
This enables the operator
to obtain a very low swr
reading, if this is necessary
to make either him or his
transmitter happy, (See Fig,
8,) This tuner worked so
well on field days that one
of the field day operators
called it the "old reliable"
antenna tuner, (This was
even before the variable
capacitor was added in
series with the primary.) In
the "old reliable" tuner, a
two-turn coil made of
number 12 house-wiring
wire is used for the
primary. This wire is stiff
enough to hold itself in
place. The primary coil's
diameter is larger than that
of the plug-in coils, and
these coils are plugged in
right through the primary
coil. (See Fig. 9 and
photograph.) Another
tuner has plug-in coils with
AMTEMUIt
TUhftD FEEOEHS
^ (GO TO ANTENNi
TUhlER>
Fig. 5. Center fed tuned
doublet antenna (often irh
correctly called a ^'center-
fed zepp"]-
120
a separate primary for
each secondary. This tuner
works well, but the swr is
not quite as low as with the
"old reliable'' antenna
tuner.
This type of tuner,
especially if built with junk
box or scrounged parts, is
inexpensive but effective.
Some other tuners such
as the DenTron Super
TunerTM ($129 50) or the
Universal Transmatch of
the ARRL Antenna Book
work well with tuned
feeder antenna systems,
but the "old reliable" tuner
does it with a lower swr
Some amateurs may ob-
ject to having to adjust the
three dials on the antenna
tuner. In practice, after C2
and C3, on one dial, and C4
are adjusted, only CI must
be readjusted when mov*
ing from one part of a band
to another.
The drawings and dia-
grams in Figs. 10 through
17 show the dimensions
and arrangements of a few
non-coax-fed antennas.
Many other tuned feeder
antenna systems can be
designed. Use your think-
ing and imagination. Al-
though open-wire feed line
is the best kind to use,
good quality 300-Ohm
twiniead works very well. It
can be brought into the
house under a window
without having lo drill
holes.
For lightning protection,
provision should be made
for grounding the feedline
outside of the house when
the antenna is not in use.
A balanced feeder an-
tenna tuner such as the
"old reliable" will work as
the series tuner for the
"center of the antenna in
the shack" arrangement by
opening out the plates of
the split stator variable
capacitor and tuning with
the ganged series-variable
capacitors. This kind of
tuner can also be used for
voltage feeding the end of
an antenna in the shack.
Short out one of the split
stator variable capacitors
ft F FROM
K ^ ^ ROM j^^
CI
TO BALANCED TUNtD FEEOEBS OF
CDHHtCT LENCTH FOfl VOiUtGE FEED
I
Fig. 6. Antenna tuner to voltage-fed balanced tuned
feeders.
It F FfTOH
e
P^
i^ C»
I
t
I
I
I
}
BALANCED TUNEQ FEEDERS
AMY LENOTH
^^
F/g, 7. Antenna tuner for balanced tuned feeders any
length.
C£ .
A
rmmsHiTTe
iTTCit V
3
c*
I *
^
Cf
SfliLANCEO TijNEO FEEQEHS
t4 C3/
Fig. 8, Antenna tuner for balanced tuned feeders any
length, with a vanable capacitor is series with the primary
to reduce the swr between the transmitter and the tuner.
Back view of single-ended voltage-fed tuner. This shows
two coax connectors switched from the front.
and connect the antenna
to the stator plates of the
other side of the variable
capacitor. A neon tube,
one side of which is con-
nected to the antenna, will
indicate the rf voltage
when the coil rs tuned to
resonance at the transmit-
ter's frequency.
You may ask, "Why
should I go to all the
bother of building a three-
dial antenna tuner and a
tuned feeder antenna
system?" "What does a
tuned feeder system ac-
complish that is not ac-
complished with my pres-
ent antenna?"' One impor-
tant accomplishment of a
balanced tuned feeder
system is that it can be
tuned to exact resonance
at any frequency in any
band for which the antenna
is designed. For example,
the 80 meter band extends
from 3500 kHz to 4000
kHz. The resonant length
for 3500 kHz is over ISSVa
feet The resonant length
for 4000 kHz is only 117
.'1
e
3
-^?-^
' I
1
I
I
if^
Fig. 8[al Using a center-
tapped coil in place of the
split stator capacitor to ob-
tain a balanced rf output
feet. A coax-fed antenna of
one length cannot be reso-
nant at both ends of the
band. With a centerfed
doublet, using tuned
feeders, the antenna
system can be made reso-
nant in any part of the
band, thus fulfilling the re-
quirement of Antenna Ax-
iom 1,
Another important
feature of a tuned feeder
antenna system is that the
rf is effectively taken from
the transmitter to the
antenna [Antenna Axiom
2).
Another advantage of a
tuned feeder antenna
system is that the antenna
tuner effectively prevents
transmitter harmonics
from getting into the anten-
na and being radiated (Ax-
iom 6). Coax^fed dipoles,
coax-fed trap dipoles,
coax-fed parallel dipoles,
and coax-fed trap vertical
antennas all accept and
Fig, 9, Antenna coil plugged
in through the heavy wire
self-supporting primary
coiL
121
"Old reliable'' antenna tuner — front view. This shows the
neon tube and the 80 and 15-10 nr}eter coils.
radiate any transmitter har-
monics that are in a band
for which the antenna is
designed, and which are in
the transmitter's output,ici
Multiband operation is
effectively accomplished
with a tuned feeder anten-
na system. An antenna.
designed for a lower
frequency band, is used
on harmonicaliy-related
higher frequency bands by
tuning the feeders to the
harmonic frequencies-i^
With a good antenna
tuner, feeder length is not
criticaK This makes possi-
Fig. TO. 33'ft. verticat and 334t ''s/anter'' commg into a
second-siory shack. Series tune both for 40 meter opera-
tion (Fig. Jl For 20 meters, voltage- feed the vertical part
only (Fig, 21 For 15 meters, feed both parts in series (Fig. 3).
The antenna can also be made to work on 80 meters by us-
ing a large coil in the series tuning arrangement
Fig. 11, An in-the-shack endfed antenna. Use parallel'
tuned coil with plug-in coils for each band (Fig. 2). This
will work on 80 meters and higher frequency bands on har-
monics. See reference 1 for means of lenglhenmg the
antenna for harmonic operation.
ble high antennas. (Anten-
na Axiom 3).
Tuned feeders can be
used with good results to
feed vertical and ground-
plane antennas that are
half vertical and half
horizontally Tuned feed-
ers have worked very
well with a Hustler 4BTV
Fig. 12. Endfed "zepp" antenna for 80 meters (CW). Use
balanced feeder tuner. This will work on higher frequency
bands (harmonic operationl Tune feeders to the frequen-
cies of the higher frequency bands. A centerfed antenna 66
feet on each side of center tuned feeders would be better,
if ali parts of the 80 meter band are to be used (both CW
and phonel
''Old reliable'' antenna tuner
plug-in coil arrangement
— side view, This shows the
""Old reliable*' antenna tuner — back view. The two coax
connectors and front switch are for switching the tuner
between receiver and transmitter or for switching between
two transmitters.
122
Another antenna tuner with primary coil which plugs in.
trap vertical antenna.
For amateurs who like to
talk {or boast) about their
low swr, the swr between
the transmitter and the
antenna tuner can be
reduced to a very low
value on all bands with
careful adjustment of the
tuner.
Tuned feeders are the
best kind to use with some
kinds of beam antennas.
For example, to use a W8J K
Fig. 13. 80 meter tuned doublet operated on harmonics for
the higher frequency bands. Use balanced feeder tuner.
This is the best all-around antenna for multiband use. (This
is the WaBVU/W0VM field day antenna.]
M»t,
Fig. 14. Vertical ''slanter'* tuned doublet for 40, 20, and 15
meters. Use balanced feeder antenna tuner. It also works
on 80 meters with the 80 meter antenna coil in the tuner.
Several "slanters'^ could be used and spaced radiaUy to
make a ground-plane antenna for 40, 20, and 15 meters.
VEItTtCAL lfi1/2 II
R OR wont
lAl^S EACH Ifi 1/2fl
Back view of the other antenna tuner
flattop beam on its har-
monics, tuned feeders
must be used. Tuned
feeders make it possible to
use V-beams on several fre-
quency bandsJ3
If the radiating element
of a rotating beam antenna
is fed with tuned feeders, it
can be tuned to exact
resonance on the frequen-
cy being used. This will
make the antenna work
better on both the phone
and the CW frequencies.
If you want to be able to
have good QSOs on any
frequency within an ama-
teur band, if you want to
eliminate any fear of har-
monic radiation, and if you
want a larger percentage of
your calls to result in
QSOs, use an antenna tun-
er and an antenna center-
fed with tuned feeders.
You will be pleased with
the results. ■
*- 9H *
ttu
=i/
Fig. 15. Cround-plane antenna for 20, 15, and 10 meters.
Use balanced feeder antenna tuner.
TO
JHfTCMH* ^
tlfN£*1
Fig. 16. A vertical "endfire"
bidirectional beam anten-
na for 20, 15, and 10 meters.
Use balanced feeder anten-
na tuner.
References
1, ^'Simple Dipole Antennas,"
Jim Ffsk W1HR, Ham Radio
Horizorrs, January, 1978, pages
18 through 26. is an excellent
article on coax-fed antennas. It
describes several antennas, in-
eluding parallel dipoles and
trap dipoles. Much useful data
rs presented. However, starting
on page 21 is a section called
"Simple multiband antennas."
This states, "There's no doubt
that the most efficient (and
sinriplest) multiband antenna is
a half-wave dipole cut to
resonate at the lowest oper-
ating frequency, centerfed with
open-wire transmisspon line
through an antenna tuner/'
2, The theory of the need for ex-
tra length is beyond the scope
TO
TuN£li
35a
Fig. 17. A "vertical zepp"
for 20 meter CW. Strung on
two bamboo fishpoles
taped together, this anten-
na has worked into Europe
from St Louis, Missouri, us-
ing a Ranger T, with only 80
Waffs dc input to the final
stage. The antenna was at
ground level and the
feeders went down a few
feet into the shacL
123
of this article. For a practical
means of changing the anten-
na's length inside the sliack,
see "A "Stretcher' for Endfed
Multiband Wires/' Howard J-
Hanson W7MRY, 0S7", July,
1972, page 32.
a. "Why Coax?" by Ed Wagner
G3BI0, 13 Magazine,
November. 1971, page 96, and
Understandfng Amateur Radio,
2nd ed., ARRL, chart on page
121,
4. See The Radio Handbook,
1939 edition, page 425. "flattop
length/' Also see page 424, Fig.
12, "The evolution of a zepp
antenna/*
5. See Understanding Amateur
Radio, 2nd ed., pages 122. 123,
"*Open-wire' Feeders." and
page 264, "The Center-fed
DIpole/' (This antenna has
often been erroneously called a
"centerfed zepp/')
6. See *'Gee, What^s a Zepp?"
Charles G. Miller W3WLX, July,
1975, 73 Magazine, page 111»
and the ARRL Antenna Book,
pages 179 and ISO, "Centerfed
Antennas/'
7. See "A Field Day to Remem-
ber/' Wiltlam R. Stocking
W8BVU, 73 Magazine, June,
1969, page 44,
8- A *'transmatch" Is a form of
antenna tuner,
9. For this capacitor, a two* or
three-section broadcast band
variable capacitor with ail sec-
tions connected in parallel can
be used. I had no swr meter for
many years and used a neon
bulb and f ieid strength meter to
tune the antenna system to
resonance. The variable capac-
itor in series with the primary
coil was added after i obtained
the swr meter. Now, as do other
hams, I keep the swr as low as
possible.
10. See the ARRL Antenna
Book^ page 188, "Harmonic
Radiation from Multiband
Antennas/*
11. See ARRL Understanding
Amateur Radio, 2nd ed., page
123, "Muiltband Operation"
and the ARRL Antenna Book,
page 179, "Centerfed Anten-
nas."
12. See the ARRL Antenna
Book, page 187, "Combining
Vertical and Horizontal Con-
ductors/'
13. See the ARRL Antenna
Book, page 174, ''Feeding the
V/'
Looking kVfest
from page IB
to go ahead and prosecute
such a case? To get them to
say: Here is an individual that
we want to take the time to
prosecute?
"There have been some In*
teresting things that we have
learned In working on this one
case. The first questions they
have asked (federal authorities)
is if there are any tapes of the
individual It is my opinion that
although section 605 of the
Communications Act of 1934
states that the privacy provi-
sion does not apply to amateur
coffimynications, and I have
not researched it, this distinc-
tion is invalid. There is no ra-
tional basis to hold that a com-
munjcation by a poiice officer
on a radio is private and cannot
be revealed to a third party and
that what \ say via a two meter
repeater need not be held so.
Stili, when you get down to the
prosecution of these cases, you
are asked if you have any tapes.
Therefore, I have recommend-
ed to several repeater owners
who have tape-logging systems
(or volunteers recording people
among the usershipj that when
jamming starts tapes be made
and a log (written) be kept and it
all be documented. It's a lot of
work, admittedly.
'I'm presently in the process
of meeting with the FCC in
Long Beach (California) to find
out just what they will want
from the amateur to go ahead
and take these cases. However,
when you get down to it, it's go*
ing to t>e basically the ama-
teur's job. You will get a lot of
lip service, a lot of excuses, and
if you convince the FCC to pros-
ecute, then you have to con-
vince the U.S. Attorney to act.
Believe me, this takes pres-
sure. Pressure is the only thing
the U.S, Attorney knows (under-
stands), In our ranks, we have
such pressure. We have
amateurs who are correspon-
dents for all phases of the
media, including major news-
papers and television net*
works. Amateur radio has got
to learn how to make use of the
members of the service. Be-
lleve me. A phone call from a
nationally-prominent news cor-
respondent can make a world
of difference as to whether a
case is prosecuted. This is one
idea. There can be no general
rule. However, iet^s phrase a
few items for you to think
about.
**Let's first explore how we
can get the government to act.
Number one, you must docu-
ment what has taken place.
You must have tape recordings
of the individual and his ac-
tivities. It also must be more
than once (thereby creating a
definite pattern of behavior).
*'You must have a DFing
crew. In cases of repeater jam-
ming, this task belongs to four
or five (dedicated) people.
White other groups might
assist, your central group
should be four or five people of
the type who would turn in their
own mother if need be. This is
t>ecause you have situations
where people (DFers) spend
time trying to disprove the iden*
tity of a jammer if it turns out to
be a friend. Also, you must have
security (total) within your
group, since premature an-
nouncements or leaks can ruin
such activities (prejudice
future litigation). One does not
sit down at a poker table, lay
out one's hand to full view, and
then start betting. Handling
malicious interference is just
that. It*s a question of playing
your cards just right and know-
ing when to make the right
move.
'Once you have set that
4lj
hypothesis, you can then pro-
ceed to build your case. Docu-
ment it. You must actually
document exactly how you did
your DFing. When you get into
the prosecution of such a case,
the federal authorities are go-
ing to ask this. Also, you must
be able to show that your DF
equipment is working accurate-
ly, and how you arrived at your
conclusions.
'*One other thing that I would
strongly urge those into DFing
for this purpose to do is keep an
accurate map of all of their
bearings, their location when
taken, the dale, and the time.
This can present a pattern and
prove a case. Once you have all
this» you then have a basis to
go to the FCC and request their
help. As 1 said earlier, we are
currently meeting with the
Long Beach FCC office, coor-
dinating our efforts so that all
this work by amateurs will not
be wasted.
"It is my opinion that the U.S.
Attorney has been instructed
by the Attorney General that
amateur radio cases of the type
involving malicious interfer-
ence are 1owest*case priorities.
I think you must face the fact
that this is what their feeling is.
They feel you are treading In an
area of First Amendment
rights. , .
^Therefore, it is important to
have some way of protecting
yourself — that is the most im-
portant thing.
"There are many other things
that can be done, but now Is not
the time to go into detail. My
purpose here was to throw out
some ideas for you to consider.
"We take tests; we learn
rules; we are told that there are
certain fines for violating the
law. We are basically law-
abiding. However, there is that
small percentage ol people 1
prefer to call mentally
demented who say, *lf I can't
talk, then nobody wilt talk,' or
who enjoy swearing and the
jamming that prevents others
from talking. Those are my
Ideas. They will be devel-
oped further. I did not become
an amateur to put up with that
stuff, and 1 don*t think that I
should be afraid to turn on my
radio in the car when my wife
and particularly my child is
there."
The above was transcribed
from a tape recording made on
September 23, 1978, at the
ARRL Southwestern Division
convention in San Oiego,
California. They are the
statements of a man who
cares, and very closely echo my
views. In the near future, copies
of this talk and others at the
special sixvhour seminar will be
made available through the
seminar sponsors. Watch your
normal amateur media outlets
and this column for further in-
formation. Comments on Joe's
ideas can be directed to him
through this column. LW will
continue watch on this topic
until the amateur service rids
itself of this menace to its con-
tinued existence.
THE GROWING WELL
DEPARTMENT
Thanks to William Oliver
Grieve W7WGW, I have some
Interesting news concerning
two meter activity in Arizona.
First, congratulations to
W7WGW on being elected as
secretary of the Amateur Radio
Council of Arizona. We at LW
wish him well in this position.
Oliver owns WR7AFC (147.60/
.00) and WR7AHJ (147,87/,27) in
the Phoenix area.
Now, how many repeaters
would you imagine that a state
like Arizona plays host to on
two meters? Well, unless I have
counted wrong, the new lisl
shows 53 such machines, in-
cluding the first two inverted
tertiary allocations on
146.745/. 145 and 146.865/.265.
Judging by this list, one should
be able to go just about any
place in Arizona these days and
have two meter communica-
Continued on page f34
124
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p^ Reader Service— see page 323.
125
Build a Realistic S-Meter
//
you're S9 + 40, OM!
//
Raif Beyer DJ3NW
Opferkamp 14
33 Braunschweig- Wa^^um
Germany
What is the most fix-
ating item in the
ham shack when you have
tuned in a signal? The
S-meter! Do you trust it?
Nol
These are hypothetical
answers to these questions,
but chances are great that
this would be the response
If someone were asked to
investigate the role of the
S-meter in many of today's
receivers. All of us have
had our own experiences
with S-meters, but a
general trend can be
observed centering around
four major problems:
1. Many S-meters show
nearly accurate readings in
the vicinity of the S9 mark.
2. Many S-meters indicate
much higher S-values than
appropriate for signals
stronger than S9.
3. Many S-meters are in-
sensitive to signals below
53 or S4. (''I can copy you
54 though you are not mov-
ing the needle/')
4. Many S-meters indicate
much lower S-values than
appropriate when SSB or
CW is received. ["Say aah
or press the key, so I can
read the meter/')
Correspondence with an
equipment manufacturer
showed that he was well in-
formed about these prob-
lems. But experience
iMPyT
ii-F o« Ar Of
ni
E er B«WT3 ■ Trttt
BUFFEW
AUFUFlEfl
RECTlFlElt
FUHCTIOft
-
J
ouTFirr
iS-«ETEH
shows that manufacturers
are reluctant to invest in
this field because of in-
creased cost and, more im-
portant, because radio
amateurs have willingly ac-
cepted the S-meters as they
are and because they have
no opportunity to check
the calibration in most
cases. A simple method is
presented to solve the
aforementioned problems
at moderate cost. The
method described is ap-
plicable to both i-f or af
signal based S-meter cir-
cuits„ However, af signal
processing was chosen for
the sake of simplicity. A
Heath SB-301 receiver was
used as the test vehicle.
The Basic Idea
A block diagram of the
suggested S-meter circuit is
shown in Fig. 1. The af
signal of the receiver,
taken in front of the af gain
control, is the input signal
for this circuit. It is routed
to a buffer to provide isola-
tion from the receiver to
keep the characteristics of
the receiver unchanged.
The signal is then amplified
to a level which allows a
diode in the rectifier circuit
which follows to conduct
even during small ampli-
tudes of the input signal If
the rectifier output is con-
nected to an S-meter and if
the amplifier has a high
enough gain to produce a
TI4^y« PfiOPQATtOllAL
OUfTPyT
ntntr
OUTFUT
OUTFtJT
Fig. t. Block diagram of the S-meter circuit
Fig. 2. Possible output waveforms which may be obtained
from a simple variable function generator using a ramp
waveform as the input
126
reasonable output even for
a small signal amplitude in-
put the circuit discussed
so far would already be
adequate to cope with
S-meter problem No. 3 (in-
adequate sensitivity for
weak signals). However, for
most receiver age charac-
teristics, the gain of the
amplifier would be too
high now for larger input
signal amplitudes. This
would cause the S-meter to
indicate a much higher
S-value than appropriate,
presenting S-meter prob-
lem No, 2 (sensitivity too
high for strong signals).
Therefore, a so-called
function generator is
placed between the rec-
tifier and the S-meter. A
function generator is a
device which produces an
output signal that can be
any function of its input
signal For example, a
signal of linearly increas-
ing amplitude (ramp) at the
function generator input
may be converted by the
function generator to a
signal which is propor-
tional or increasingly more
or less than proportional to
the input signal (Fig. 2).
It is obvious that prob-
lem No. 2 can be solved if a
function generator with a
degressive [increasingly
less than proportional) in-
put/output transfer func-
tion is placed between the
rectifier and the S-meter.
The selection of an ap-
propriate transfer function
depends, of course, on the
transfer function between
the receiver antenna input
and the rectifier output
[determined mainly by the
gain control characteris-
tics of the receiver) and on
the layout of the S-meter
scale. Both, however, can
be matched to each other
by the function generator
so that signals at the
receiver antenna terminal
which range, for example,
from SI to S9 -F60 dB are
correctly indicated by the
S-meter,
With the system described
so far, it is possible to
oirrCfiEiiTrATOft
iNPtiT
fiCVR A F
OUTPUT
r-
I ns
1 ^J^
LJ !
wo I /
BUFFER
AWPLIFIER
RECTIf^lER
fUWCTlUWOtBlfHfllOH
&3VAC:*
QROimC
*l4av&C
i" =
6R0UNC1
fig. 3. Schematic diagram of the S-meter circuit and power supply. CR2 is a tow forward-
bias germanium diode, Siemens RL32g or equivalent CR3 through CR6 are BA Y18 diodes
or equivalent. Ml i$a1 mA, 100-Ohm internal resistance unit U1 is an MC1437L dual op
amp or equivalent
obtain an accurate indica-
tion of the signal strength
for static (key-down) sig-
nals. Keyed or modulated
signals, however, make the
needle fluctuate which
makes reading the meter
difficult (problem No. 4). A
large capacitor in the rec-
tifier circuit would help, of
course, to make the meter
needle more steady. But
the limited output power
of the amplifier, its output
impedance, the impedance
of the rectifier, and the in-
ertia of the moving coil in
the S-meter form a low-
pass filter which prevents
the needle from reaching
the same position for
CW/SSB reception as for an
identical key*down condi-
tion. And, a large capacitor
makes the S-meter similar-
ly less responsive in the
other direction, too, be-
cause the decay time cons-
tant IS also increased. This
prevents the S-meter from
showing a quick dip when
comparing barefoot/linear
operation or when looking
for a minimum in antenna
radiation pattern tests.
In order to overcome
this problem, some form of
"quickening" of the rec-
tifier output signal or the
meter needle movement is
required. This can be
achieved by feeding the
rectifier output signal into
a differentiator whose out-
put signal is then fed back
to the input of the
amplifier [Fig. 1). Now, let
us assume that a signal at
the input of the circuit
shown in Fig. 1 produces a
positive signal at the rec-
tifier output. Then an in-
creasing amplitude of the
input signal produces a
positive slope of the rec-
tifier output signal, too.
The differentiator con-
nected to the rectifier out-
put also produces a posi*
tive signal at its output
which is proportional to
the slope of the rectifier
output signal. And, be-
cause this signal is fed
back to the input of the
amplifier, the differentia-
tor output signal drives the
rectifier output signal to a
higher level, temporarily
giving the rectifier output
signal and the meter
needle the desired ''extra
punch" in the right direc-
tion.
For a decreasing ampli-
tude input signal in Fig. 1,
one would expect a similar
effect which, however,
would drive the meter
needle in the opposite
direction because the dif-
ferentiator output signal is
negative for a negative
slope of the input signal
amplitude. This would can-
cel the desired effect just
achieved, so nothing
would be gained. But
because of the fast at-
tack/slow decay character-
istics of the rectifier cir-
cuit, a rising amplitude in-
put signal produces a
positive and much steeper
slope of the rectifier out-
put signal than a drop of
the input signal amplitude.
A drop in signal amplitude
produces a negative but
much shallower slope of
the rectifier output signal.
For a constant amplitude
input signal in Fig. 1, the
differentiator is inactive,
of course, and does not af-
fect the remaining part of
the circuit.
The Circuit
A schematic diagram of
the S-meter circuit is
127
MUtTiPi^ mempwm^
FUNCTION
APPfiOKlWilTED
tftANSFEfi TUNC-
T(ON
CM
Lm
Fig. 4. Approximation of a desired transfer functior} by a
function generator having a single breakpoint. Fig. 4(al
and mukiple breakpoints. Fig. 4{bl
shown in Fig. 3. A dual
operational amplifier is
used for both the buffer
and the amplifier. Both am-
plifiers are frequency com-
pensated by means of CI,
R3, C2, and C4, R7, C5,
respectively, as recom-
mended in the manufac-
turer's data sheet. The re-
quired supply voltage of
±15 V dc is provided by
two voltage-doubling rec-
tifier circuits connected to
the 63 V ac filament sup-
ply of the receiver.
The af signal of the
receiver, taken from a
point preceding the vol-
ume control potentiome-
ter, is connected to the in-
put terminal of the circuit.
A shielded cable is recom-
mended for this connection.
The buffer, U1A, which
follows provides a high in-
put impedance to the
receiver so that the af cir-
cuit of the receiver is not
affected. The buffer out-
put signal is coupled to the
amplifier, U1B. The input to
this amplifier is controlled
by trimmer potentiometer
R4. This potentiometer is
adjusted such that a max-
imum signal amplitude of
S9 + 60 dB at the antenna
terminal of the receiver
causes the output ampli*
tude of amplifier U1B to
just reach the limits of
linear operation, i.e., ap-
proximately ±12 volts. Of
course, potentiometer R4
can be adjusted so that the
amplifier is driven into its
output limitation for sig-
nals greater than S9 + 40
dB or so in order to con-
tribute to the desired
degressive transfer behav*
ior of the S-meter circuit.
However, it was not found
necessary in the case of the
SB-301 receiver. The ampli-
fied af signal is then rec-
tified by the rectifier cir-
cuit which follows. A ger-
manium diode Is recom-
mended for this circuit.
The rectifier output is a dc
signal which represents the
amplitude of the rf signal
at the antenna terminal of
the receiver. The function
generator which follows
modifies this signal in
order to match its slope to
the graduation of the
TftAWSrEl^ FUNCTION
OOTAlWED FOR
RQ +R^ ■ 9300a
RID <Dn
tUMfiE OF
FUliCTfDiWS
PD
e m ivj
fig. 5. Rangeof transfer functions which can be obtained
with the function generator and the S-meter of Fig. 3,
Values of R10 range from zero to an indefinitelY targe
value and R8 and R9 adjusted for full-scale output (1mA)
at maximum input (10 volt si
S-meter scale.
The Function Generator
Fig. 3 shows the diagram
of a simple function
generator with one so-
called "breakpoint." The
breakpoint determines the
amplitude of the signal ap-
plied to the generator in-
put at which the input/out-
put transfer function of the
generator is switched from
an initiaf slope to the final
slope. Diode CR2 in Fig. 3
acts as the switch. For an
ideal switch with normally
open contacts and con-
tacts closed when a signal
of given amplitude is ap-
plied to the function gener-
ator input, the transfer
function which can be ob-
tained is shown as a broken
line in Fig, 4{a). For a given
impedance of the S-meter,
the generator transfer func-
tion would be controlled by
R8 and R9 (Fig. 3) alone up
to the breakpoint But, when
the breakpoint is reached,
the switch is closed and
RIO is effective. The
amplitude of the generator
output signal is immediate-
ly reduced to a lower level
[which is not desired), but
the steepness of the slope
of the resulting transfer
function is also reduced,
which gives a first-order ap*
proximation of the desired
transfer function as shown
in Fig 4(a) For a closer ap*
proximation of the desired
transfer function, more
breakpoints (switches) are
required as shown m Fig.
4(b). However, as the diode
CR2 in Fig. 3 is not an ideal
switch, and because it
becomes only gradually
conductive, the diode char-
acteristic can be used to
advantage, thereby elimi-
nating the need for multi-
ple discrete breakpoints.
Fig. 5 presents the range
of calculated transfer func-
tions which can be ob-
tained with the function
generator shown in Fig. 3,
The slope of the transfer
function depends on the
characteristics of diode
CR2, of course. The diode
shown in Fig. 3 was taken
from the )unk box, but
comparable results can be
obtained with other ger-
manium-type diodes which
have a low forward bias of
Ud = 200 mV at Ip - 02
mA and Up - 350 mV at
Id = 1 mA,
The Differentiator
"Quickening" of the
S-meter is achieved by
feeding back the output of
the twofold differentiator
shown in Fig. 3 to the input
of the amplifier. The out-
put can be adjusted by
means of R12. This type of
adjustment was found to
be more convenient than
changing capacitors C7 or
C8. Furthermore, the ter-
minating resistor, R11, at
the non-inverting input of
amplifier U1B was kept
constant by this method in
order to avoid ill effects on
the remaining circuit.
As an ordinary S-meter
indicates the average cur-
rent flowing through the
meter with respect to time,
the amount of "quicken-
ing" is determined by the
average amplitude of the
differentiator output sig-
nal. The average amplitude
of a signal, however, is
determined by its average
deviation from zero. Posi-
tive deviations are counted
positive and negative devi-
ations are counted nega-
tive. Fig. 6 presents two
computed output func-
tions of the differentiator
shown in Fig. 3 obtained for
identical inputs and dif-
ferent values of R12. It can
be seen that a large value
of R12 increases the (posi-
tive) average amplitude of
the differentiator output
signal and thereby the
amount of "quickening."
Optimum "quickening" is
determined by a number of
factors such as the time
constants of the rectifier
circuit, the damping of the
S-meter, and so on. A value
of 100k Ohms for R12 was
found to be optimum when
128
Wow!
A Good Portable Receiver!
thanks, Panasonic!
Photo by Robert Hinman WA2DIZ
Joseph W. Long WA2EJT
Chenmtry Dept.
Broome Commumiy Coiiege
Bingham f on NY 13902
The Panasonic RF-2200
is a unique myltiband
receiver and should be of
great interest to manv
amateurs. The receiver
tunes standard broadcast
AM and FM and is general
coverage rn the shortwave
spectrum from 3,9 to 28
MHz (more about the
shortwave frequency limits
later on).
There are several items
which make this receiver of
so much potential interest.
The first concerns the
shortwave section. The
coverage is in 6 bands,
each 4 MHz wide, which
are tuned with a linear dial
scale calibrated every 10
kHz and which can be read
to within about 3 kHz
throughout the whole
shortwave spectrum.
There are two built-in
crystal calibrators, one at
0.5 MHz and one at 0.125
MHz, with which the dial
may be very accurately
calibrated. When cali-
brated at the appropriate
spot, any frequency
throughout its range may
be dialed up with the
volume off. Turning up the
receiver volume will bring
in the station if it can be
heard. Shades of the
R-390/51 I Collins general-
coverage receiversi
The vfo tunes over 4
MHz, but, even with this
range, the dial is surprising-
ly linear. For example, my
RF-2200 on band SW 3
(12-16 MHz), when cali^
bra ted at 12 MHz, has a
dial error of no more than
10 kHz all the way up to
15.5 MHz. The 16.0 MHz
point is off by about 20
kHz,
Turning on the cali-
brators automatically
disconnects the antenna,
turns on the bfo, and
declutches the linear dial
so that there are no points
to offset. That's just about
like it's done in my Collins
R-391.
The receiver also has an
excellent product detector
tuning meter and rf gain
control, making it great for
use within the ham bands.
Also useful are a wide/nar-
row i-f selectivity switch
(narrow is not very narrow),
separate bass and treble
controls, and a Ewo-speed
dial.
The SW section of the
RF 2200 is very hot and the
built-in whip antenna
brings in all manner of
signals. The receiver is
advertised as tunable from
3.9 to 28 MHz, but mine ac*
tually goes all the way
down to 3.5 MHz, with the
dial getting rather
nonlinear. It also tunes
above 28 MHz — to just
above 28,5 MHz.
For $140, you don't get
everything, of course, and
the receiver does have
some deficiencies which
must be mentioned. First
there is a slow drift during
reception of CW and SSB
signals which is indepen-
dent of frequency- The in-
struction manual suggests
that the bfo be turned on 5
minutes early for "won-
derful CW and SSB re*
ception.'' This suggestion is
helpful, but there remains
a slow drift even after long
periods. Since the problem
does appear to be caused
by drift in the bfo circuit '
suspect that it could be
cured fairly easily.
Another deficiency is a
dead space in the tuning
gears. This is only dead
space; the signals do not
keep going the wrong way
when you reverse direc-
130
the circuit was installed in
a Heath S 6-301 receiver.
Compared to the indica-
tion of the S-meter for a
key-down signal from a
transmitter, this value of
R12 produced an almost
identical indication on the
meter when SSB (processed
and unprocessed speech)
was used and only ^ slight-
ly higher one for CW.
Construction
The circuit shown in Fig.
3 was bui[t on a 65mm X
65mm (2Vi-inch x
2 Va-inch) Vector board.
Helitrim'^ potentiometers
were used for all poten-
tiometers because they are
small and convenient to
adjust. All other com-
ponents are miniature size
A socket was used for U1.
The board has four ter-
minals: ground, 6.3 V ac,
receiver af, and S-meter.
The board was mounted at
the back of the front panel
of the SB-301 receiver by
means of a mounting
bracket held by the screw
in the upper right-hand cor-
ner of the panel. A shielded
cable was used for the con-
nection between the "hot"
end of the receiver af gain
control and the input ter-
minal of the circuit*
Alignment
A signal generator and
an attenuator are required
which can provide an un-
modulated signal on all
bands of interest within the
range of S1 through S9
+ 60 dB. A signal ampli-
tude of 50 microvolts at
the 50 Ohm antenna ter-
minal may be used for S9
and half the amplitude
( — 6 dB) of the preceding
S-value for the next lower
S-value, i.e., 25 microvolts
for 58 and so on [1 dB = 20
' log(Vout/Vin) for the at-
tenuator]. Some signal
generators are calibrated
to produce a signal of
given amplitude if the
generator output is unter-
minated (open) Others are
calibrated for an output
terminated with 50 Ohms*
One should be sure which
type of generator is on
hand before the alignment
is started.
First, the receiver should
be checked to be in good
condition and for uniform
gain on all bands of in-
terest. With the rf gain con-
trol set to maximum gain,
age on, mode switch set to
USB, LSB, or CW, and the
receiver tuned for max-
imum input to the S-meter
circuit each band should
be checked to note what
signal amplitude at the
antenna terminal of the
receiver produces a given
beat note amplitude at the
af input of the S-meter cir-
cuit. For the SB-301, iden-
tical beat note amplitudes
were obtained on all bands
with an input signal varia-
tion of less than ±1 dB
(±1/6S-unit).
Next, the receiver should
be checked for uniform
gain in all modes. It was
noted, for example, that
for a constant signal
amplitude at the antenna
terminal of the SB-301, a
somewhat higher beat note
amplitude was obtained
when the receiver was
switched from LSB to USB.
The reason for this was a
higher signal amplitude of
the bfo crystal used in the
USB mode. A potentiome-
ter across the terminals of
this crystal was used to
reduce the bfo output
amplitude in this mode so
that a uniform receiver
gain was obtained for both
USB and LSB modes. No
separate CW filter was in-
stalled in the SB 301 which
may have a passband at-
tenuation different from
the SSB filter. And because
the USB crystal is also used
for CW in the SB-301, an
identical receiver gain was
obtained in the CW mode,
too.
Next, the function gener-
ator is aligned. This should
be done on a band on
which the receiver has an
average gain compared to
all other bands. Three
parameters of the function
COUTIVI
1000
TIME r^i
Fig. 6, Calculated response of the differentiator in Fig, 3 to
a I'volt positive-going pulse using different values of R12.
generator transfer function
can be adjusted within
given limits (see Fig, 5): the
initial slope (primarily con-
trolled by the sum of R&
and R9J, the input voltage
at which the breakpoint oc-
curs [prtmahly controlled
by the ratio of R8 to R9),
and the final slope
(primarily controlled by
RIO). It is generally possi-
ble, therefore, to adjust the
transfer function of the
generator so that it passes
through one given point of
the desired transfer func-
tion left of the breakpoint
and through two other
given points right of the
breakpoint. At other
points, there may be a
deviation of the transfer
function which can be im-
plemented from the de-
sired one. But the trick is to
find those three reference
points of the desired
transfer function to which
the function generator can
be adjusted almost per-
fectly, while the average
deviation at all other
points is reduced to a
minimum. For the SB-301,
such points were found at
55 (left of the breakpoint]
and S9 and S9 + 40 dB
(both right of the break-
point) By an iterative pro-
cess, R8, R9, and RIO were
adjusted so that for ap-
propriate signals at the
antenna terminal of the re-
ceiver, the S-meter showed
accurate S-readings at
these points and a max-
imum deviation of about
±2 dB (±1/3 S-unit)at all
other points. The average
deviation was less than
that and negligible for
signals below S9 + 10 dB.
Conclusions
fn 1969, the S-meter cir-
cuit was installed in a
SB-301 receiver and has pro-
vided stable operation since
then. No realignment has
been necessary so far, but
annual checks of the receiv-
er are recommended. It is
helpful, therefore, to keep
a record of the S-meter
readings which can be ob*
tained with the internal
crystal calibrator of the
receiver on all bands. Any
deviation from these val-
ues which may occur later
indicates that the perfor-
mance of the receiver, the
S-meter circuit, or the
calibrator is degraded and
that there is something to
be done.
The S-meter problems
listed in the introduction
were solved satisfactorily
and the S-meter reports
became more meaningful
and objective. This is par-
ticularly useful for relative
reports, e.g., a comparison
of barefoot/linear opera-
tion or antenna checks. Ab-
solute reports may be ac-
companied by a short
statement on the antenna
used, on topographical pe-
culiarities, and on the ac-
curacy of the S-meter. But
simply spoken, it is a real
pleasure to give that low*
power or faraway station a
better and accurate report
and not to fool others with
unrealistic S9 + 20 dB
reports. ■
129
tions; they just don't
change at all. The effect is
noticeable only on CW and
SSB. Even at low speed, the
tuning is a bit fast for CW
and SSB — a very delicate
touch is required. Other-
wise, the feel of the tuning
is really excellent and
smacks of quality.
In the higher SW bands,
the rf gain control pulls the
signals quite a bit. I actual-
ly rather like this deficien-
cy, as it can be used as a
fine tuning control
A fourth problem is the
presence of an unusual
kind of spurious signal
When very strong CB
signals are tuned in on
band 6 [24-28 MHz), they
can still be heard on band 5
(20-24 MHz) at the same
points on the dial It
sounds as though there is
some sort of leakage in the
hfo chain in the front end.
This does not seem to be a
serious problem; the only
place I have noticed it is
with very strong CB signals.
A test which it occurred
to me to make just as I
write this is for mechani-
cal stability. A good rap on
the side of the set, or a two-
inch C5.08 cm) drop test will
not throw the receiver off
from zero beat. Amazing!
There are many com-
ments which are important
regarding the AM and FM
bands on the receiver. The
AM reception is excellent.
It is extremely sensitive,
and it seems much less sus-
ceptible to noise pickup
than most other receivers.
For example, in my office
at work I can regularly
receive WQXR from New
York City (over 100 miles
awayX while other radios
from the same spot can
barely get the local
Bingham ton stations
through all of the fluores-
cent light noises. This noise
immunity really amazes
me; I wish I could explain
it.
The dial is calibrated
every 20 kHz on the BC
band and is quite accurate;
the greatest error on my
•^
2200 is about 10 kHz
around the middle of the
band. This is infinitely bet-
ter than the calibration on
most other transistor
radios I've seen.
The AM antenna may be
swiveled. It's on the top of
the radio, is calibrated in
degrees, and may be used
for amateur direction-find-
ing. When I've tried it, all I
was able to prove was that
Binghamton, New York, is
somewhere in the middle
of the Atlantic.
I have saved one of the
nicest sections of the re-
ceiver for last: the FM
band. FM on this set is truly
outstanding. It is about the
hottest FM receiver Tve
ever heard; it outshines my
$700 Mcintosh FM tuner in
this regard. One evening,
my girl friend and I logged
stations from Syracuse^
Utica, Scranton, and
Wilkes Barre on the built-in
whip antenna from a lo-
cation where other port-
ables can hear the local
stations and nothing more.
The 2200 has very few
spurious responses on FM,
many fewer than I have
ever seen on any other FM
portables.
The FM selectivity is
also outstanding. Bing-
hamton is blessed with two
very powerful stations on
98.1 and 99.1 MHz, yet
WBRE in Wilkes Barre, on
98.5 MHz (about 70 moun-
tainous air miles away and
very weak), can be tuned in
easily. FM dial readings
may be estimated quite ac-
curately, using the built-in
logging scale, to about
plus/minus 03 MHz,
The audio in the set is of
first quality. The receiver
produces several Watts of
very clean sound. Every-
one who has heard it
agrees that it sounds unbe-
lievably good. This high-
quality audio is, of course,
somewhat wasted on the
AM and SW bands.
The receiver will play on
internal batteries (4 D cells,
included) or on 110 volts
by plugging in the line
cord. Battery life is very
long.
The packaging of the ra-
dio is very nice. It has an at-
tractive but rugged pi as*
tic case, the controls are
well and plainly marked,
and a momentary-on dial
light is included for night-
time spy radio listening I
understand that an exten-
sive service manual is
available for $3.50, which
can be obtained from Pan-
asonic service centers.
I became hooked on the
set when I got to play with
one my baby brother had
purchased and was raving
about. After fiddling with
my 2200 [when they should
have been working), two of
my co-workers rushed out
to buy their own and a
third is thinking of how he
might slip one past his
wife. The 2200 disease is
very contagious!
The set should be avail-
able from dealers well
stocked in Panasonic gear.
The prices seem to range
from about S117 at 47th
Street Photo in NYC [which
ts usually out of stock) to
$138, which I paid at a dis-
count store here in Bing-
hamton.
This little box is a real
jewel It is unique in the
high quality of all three of
its bands. Its "new tech-
nology" SW circuitry and
tremendous audio make it
a set that any receiver buff,
as welt as many others, will
want to own.
I would like to etn-
phasize that I have noth-
ing to do with the Pana-
sonic company (I wish 1
did!) and that this article is
unsolicited. The article is
just an attempt to provide
an honest report on a nice
piece of gear to people
who may be interested. ■
131
Willmm P. PiykrAH6AQ
IS02-A Tinker Ave.
Honolulu HI 96818
The XITEX Video Terminal
a quiet alternative
to your Model 15
I have been in RTTY for
about two years and
have decided to do
something about all the
noise in the shack caused
by the Model 15 printer. I
visited a fellow ham and
looked at his video ter-
minal and knew at once
that video was the course
to follow.
We Air Force types are
not what you would call
"rolling in the money," so I
looked for some type of kit
to assemble. I took my
search to the usual month-
ly publications, but this
proved to be in vain, as
everything appeared to be
encoded in ASCII and we
hams must transmit in
Baudot. As my search pro-
ceeded, I still wasn't hav-
ing very much luck, until,
one day, I spotted an
advertisement in 73.
Reading further, I was im-
pressed with the fact that
this video terminal would
interface in ASCII and
Baudot, This video ter-
132
minal is the SCT-100, by
XITEX, P.O. Box 20887,
Dallas, Texas 75220.
Not only does this 5'' by
10'' board speak both
ASCII and Baudot, but also
t won't have to hock my
ham gear to be able to af-
ford it. Now whenever the
FCC decides to let hams
use ASCII, or 1 figure out
what computers do, I will
be ready.
This video board has the
capability for serial ASCII
or Baudot, full X-Y cursor
control, 128 characters in-
cluding upper and lower
case, 16 lines by 64
characters, S-100 com-
patibility, and operates on
7 V dc unregulated or 12.5
V ac at one Amp. The
SCT-100 single-card ter-
minal interfaces directly to
any computer or modem
having serial ASCII or
Baudot capability. It re-
quires only the addition of
an ASCII keyboard and a
TV monitor or modified TV
set. It's available in two kit
forms or prewired and
tested.
Well, 1 have to admit
that all this looked good to
me, but t am just a ham
and I don't know much
about computers, key-
boards, etc. This was
solved, however, by a call
to the factory. After talking
to them a bit and asking a
few very elementary ques-
tions, 1 ordered a prewired
and tested unit, and now,
at last, I am on the way to
ridding myself of a lot of
noise. I ordered a keyboard
kit from a parts distributer,
so now 1 am into this thing
wholeheartedly.
As fate would have it,
the keyboard arrived first,
so, at once, I went off to
my local parts supplier,
purchased two chassis, and
picked up a copy of the
TVT Cookbook. I would
definitely recommend this
little book to anyone at-
tempting any video ter-
minal project. Now, I sup-
pose one can put the
keyboard and the terminal
board in the same chassis;
however, 1 often like to do
things the hard way.
The keyboard was a
cinch to assemble, only
taking about one hour. I
checked it out and it per-
formed okay. The messy
part is cutting the chassis
and causing small bits of
metal to fly all over the
shack. I performed a few
measurements, cut the
hole in the keyboard
chassis, and installed the
keyboard. It looked okay
except for all the scratches
that were added to the out-
side of the chassis. So
out the door 1 went to the
local hardware store for
some contact paper to give
the whole thing that
''wood-grain look." After
applying this to the chassis,
it looked a lot better. I also
installed wooden wedges
to give the keyboard the
proper angle for ease in
typing ... I don't think this
video
on a
until
Step wifl improve my typ-
ing, but it looks better.
Next, I moved to the
chassis that would house
the video terminal board. I
installed a 12.5 V ac
transformer and a 5-Ohm
resistor to supply approx-
imately 8 V ac to the on-
board supply. The SCT-100
has a 5 V dc regulated one-
Amp power supply on
board, and this is enough
to power the video board
and the keyboard. How-
ever, if your keyboard re-
quires -12 V dc, you will
need to add a -1 2 V dc sup-
ply. I must point out that
the parts are not critical
and most can be obtained
from the average junk box.
The next move was to
tiptoe upstairs and kidnap
my daughter's 12" TV for
modification to a video
monitor. This TV
monitor was used
time-share basis
Christmas when we pur-
chased another one for her.
I used the guidelines from
the TVT Cookbook to
modify the TV. My only
catch was that the TV
turned out to be a hot
chassis set. This problem
was solved by using two
old TV transformers and ty-
ing their 6.3 leads together
to make an "el cheapo"
isolation transformer.
At last the UPS package
arrived, and it was time for
the task of tying all the
components together* First
you should read al[ the in-
structions; then the same
instructions should be read
again and again, I know the
first thing one usually does
is to cast aside the instruc-
tions and proceed full
speed ahead. This may be
okay for some people, but
not me. As I have said
before, I often do things
the hard way.
Now that the instruc-
tions seemed clear, I made
all the connections that
would be required. 1
planned for the future and
made the provisions for
RS'232 and a 60 mA loop.
There is one point here that
I would like to bring up.
There are some voltage
points called E3, 4, and 5.
These are used to connect
either an external 5 V dc
supply or approximately 7
V dc to the on-board
regulator, or to strap the
on-board supply to the cir-
cuit. This is not clear in the
instruction, and one can
look at the diagram to
make the connections-
Now for the moment of
truth, I hooked up the
video monitor and
powered up. This produced
a screen full of garble, so I
cycled the power switch
and the screen cleared up
and the cursor moved to
home. The instructions
make clear that if clearing
is encountered, a capacitor
change is in order.
Next I jumpered the
RS-232 in/out ports
together and plugged the
keyboard in for keyboard
checkout, first checking all
the key functions in ASCII
and then proceeding with
the Baudot checkout. The
Baudot mode had no let-
ters. After reading all the
directions, I strapped my
133
keyboard for upper case and discussed this situa- I next turned on the rig. Bob Farrier for all their
only and the Baudot func- tipn with John McC radv. ^.called CO. and had mvfir^it ^s<iistanrp
The parjujieters of tJ|§ Palomar PTR-130k are
the ouier perime
n ] I m n In iiHiA I ui
iiiniiiiiiiH
[■1^11
/alnnim PTR 130k!
\l'^ \}w first uimpletiily nuil
firnctjdniil tia(iscitiv(*r t^vm mad*?
<ivj|jfiblr^ to IfK! (HI bite*
Thtr Piiloninr PTR- 130k is ii
miniaturizftd ni<>l)il(; iriinsctjivcr
Ci»ptil)le uf a|>(!r^iliiuj in 100 cycU;
n*!^oliilion from 100 KM/ k)
30 Mf!/ in iill n1(K^^??;uf
h. ins miss I on und nicupuon.
Iiisiant fiequiincy selection is
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The Palomar PTR -130k.
Krchnulotjv is pun? ^uivai acjo , . .
Ih*j pricf? is strictly down to (jarth
Sentl for our lull color
brochure to:
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665 Opper Street
Escondido, CA 92025
Telephone; (714} 746-2666
i y^.
'^/Oifjl
Sjh
^AJjQ
jsb-
f*Tfi.
'3QK
»»U
^t^Q
AM
CW LSB
^''fiOUf
/ ^a
Ncy
LC
m
T t L H N O L O G Y A I T H 1 bPl F P ^^ \
U P
imnjiinniiln
Fig. 2. PC board.
connector or to the
readout if desired. There is
a total of 16 wires used, so
a 15"pin connector can be
used if the ground wire
to easily mount the board
artd readouts inside with
room to spare.
1 hope this article will be
of help to the many hams
Fig. 3. Component layout [fait side view]. Strap ground
wire with 24 gauge.
turn on the inside light of
the vehicle. I hope that no
one thinks that I stole their
idea; it was not intended, 1
mention: You can also use
an external 5-voIt regulator
instead of the 5 volts from
the radio; however, in my
MADISON
ELECTRONICS SUPPLY, INC.
1S08-B McKINNEY
71 3/658-0268
HOUSTON, TEXAS 77002
Nites 713/497-5683
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ELECTRONICS SUPPLY, INC.
1508-BMcKrNNEY
713/658-0268
HOUSTON, TEXAS 77002
Nttes 713/497-5683
BHinN
p^ Heatfer Sen/ Ice— ^ee page 323.
139
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High Seas Adventure
Ham Style
part III
ntotos by Jules Wenglare W6YO
James E. Seidel WA6FEf
1066 N. WestsideSL
Porterville CA 93257
i i #^ ommercial broad-
^^ cast stations and 40
meter harmonics literaHy
dominated the 20 meter
band. No stateside signals
were heard for several
days, Very little was heard
from anywhere."
That was the comment
Jules Wenglare W6YO
made about his amateur
radio activities in the South
China Sea during his 10-.
month around-the-world
cruise. He had set sail from
Freeport in the Bahamas
five months earlier aboard
the Yankee Trader. In a few
days the ship would stop at
still another exotic port:
Singapore.
The Trader docked in
Singapore on July 18, 1977.
^'There were countless
numbers of ships in the
bay/' said Jutes, "making it
very difficult to get dock
space. The city looked very
beautiful from the water-
front."
After customs clear-
ance, the passengers were
allowed to go ashore. Jules
contacted Doctor Charan
9V1NR at his dispensary,
and later went to his home.
While there, he had a
chance to get on the air for
some ham contacts.
After an eyeball QSO
with another ham. Bud
9V10I, Jules purchased a
ticket at the airport and
flew to Bangkok, Thailand,
where he met Bill
HS1ACU, and a former co-
worker from Delano, Dean
Bartelet
During the weekend In
Bangkok, Jutes went to the
coast. He said he saw many
"water scooters'' being
used. They are a very
popular sport here and
something one just
wouldn't think people on
the other side of the world
would be doing. And the
traffic in Bangkok? "It was
bedlam/' lules mentioned,
"with motor scooters,
bikes, rickshaws, taxis, and
wagons everywhere."
On Sunday, Jules con-
tacted Dieter HS1ALG, an
electronics professor at
Bangkok University. At
Dieter's apartment, they
got on the air for some
good DX. One nice chat
was with Bill W7PHO, a
well-known ham in the DX-
world from Seattle.
While Jules was here, he
learned that there is no of-
ficial licensing in Thailand.
A person interested in
becoming a ham must join
a radio ctub and then be
issued a call through the
club. Kam HS1WR runs the
show.
After a five-day en-
joyable stay in Bangkok,
fules took a two-hour flight
back to Singapore. Upon
arrival, he learned that the
ship's stay had been ex-
tended a few more days in
port. This gave him a
chance to do a little more
visiting.
Bud 9V10I and his wife,
Jan, hosted Jules for dinner
one night. Jan, whom Jules
complimented about being
an excellent cook, would
like to open a Chinese
restaurant in southern
California after Bud retires.
From the way Jules praised
her cooking, especially the
chicken wings in a special
sauce, I'm sure her
restaurant would be a
great success.
Bud lives in a 20-story
apartment building and his
beam is about 280 feet
above ground. This sure
makes for good DXing.
Jules got some air time and
again talked to John W6UZ
back in Delano. He said the
DX was very good.
I ules went to the post of-
fice and had this to say:
"Mailing tetters in
Singapore was a chore You
always had to wait in a
long line Boy, they weigh-
ed every letter, wrote down
the price, and then gave
you a stamp separately for
every card or letter, On
postcards, you had to stick
on an air mail sticker,
Bothe the stickers and
postage stamps had very
little glue on them. You'd
stick 'em down and they'd
come off. They had glue
bottles all over and you'd
get glue alld over your
fingers, and, oh, what a
mess/'
When the Trader was in
Tahiti, the ship's radar
went out, and the replace-
ment part caught up with
the ship in Singapore Jules
assisted in its installation.
It arrived at the proper
time.
When leaving Singapore
and sailing through the
straits, two extra crew
members had to serve as
lookouts on the bridge
because there were so
many other ships coming
142
and gofng. Half of them
didn't have fights, "It was a
nightmare/' Jules said,
"We were thankful that the
radar was working again/'
As the Trader sailed
toward Penang, Jules said
the DX was good only in
the evening. When the ship
got closer to Penang, he
made contact with Mai
9M2MW and tried to ad-
vise him that the ship
would be in port in the
morning. The signals were
too weak, but Harry
K6MOO heard both of
them very clearly, and in-
stead of a 100-mile direct
contact, a round-trip relay
of over 15,000 miles was
made.
After the Trader an-
chored at Penang on
August 3, Jules went to the
post office. While he was
standing in line with some
of the other passengers,
this fellow came in and
asked another American if
he knew Jules. Well, Jules
was standing only a few
feet away, It was Eshee
9M2FK, whom he had
worked earlier when at sea.
They left the post office
and called Mai 9M2MW,
who met them; later, all
three went back to the
ship. They got on 40 meters
and worked several of the
local hams who were on a
net.
One of the trips Jules
took here was up the side
of Penang Mountain, As
one of the cable cars goes
up, another one comes
down. They both use the
same single tracks. About
midway up, the tracks
divide into passing tracks.
(There had better be no
mistakes here.) From the
top, Jules could see the
two bright lights aboard
the Yarikee Trader, some
five miles away in the
straits.
Mat 9M2MW and his
wife, Patricia, also hosted
Jules one night for dinner.
Mai is interested in
Teletype^M and has
several pieces of RTTY
etjuipment some of which
is home brew While he was
here, he met Chong 9M2DJ
andTan9M2DW.
Jules, along with some
other hams, helped in tak-
ing down MaTs mast and
tri-band antenna. The
weather and corrosion had
attacked the connections
and the swr was getting
high. He said it was a
miracle that they got it
down in one piece, due to
the small area in the
backyard.
While here in Penang,
Jules visited the home of
Eshee 9M2FK, who works
for the port authority. His
radio shack, located in the
back of his home, is a very
neat layout. In his portfolio
of awards and certificates,
Jules found an award from
the Northern California DX
Club.
The time had finally ar-
rived for Jules to leave
Penang. Within a few hours
after setting sail for Colom-
bo, he contacted a ham at
Clark Air Force Base in the
Philippines. He received
the satellite weather report
for the area which showed
pretty good weather. Later,
he got into Reunion Island
(FR7) for an unusual con-
tact, and then several U.S.
stations. He also talked to
John 4S7JD, the manager
of the Voice of America
radio station in Sri Lanka.
For the next few days,
Jules filled several pages of
his logbook working sta-
tions all over the world. He
said he even had a perfect
contact with an American
at the embassy in Brasilia,
Brazil. He also checked in-
to the SEANET (South East
Asia Net], which, at the
time, was being run by Carl
S79R, in the Seychelles.
Also, one evening, Jules
worked about seven 4S7s; a
couple of them were at the
home of John 4S7JD.
On August 13, the Trader
pulled into Colombo, Sri
Lanka (formally Ceylon),
after sailing five days from
Malaysia. Most of the
passengers set out for
various parts of the coun-
try, but Jules had personal
guides waiting for him at
the dock. It was John
4S7JD and Shanti 4S7WP,
a radio operator aboard a
tanker out of Colombo.
Since J ules was to be the
house guest of John 4S7JD
for the duration of his stay
here, that's where he went.
Jules and John had first
worked each other when
John was in Liberia back in
1965. This was the first
time they had ever met in
person and they had plenty
to talk about, having
mutual friends in the VOA.
John had invited many
of the hams over to his
home to meet Jules. About
6:00 pm, they began to ar-
rive. Jules met the follow-
ing: Fernando 4S7BC;
Senevi 4S7SW, whom Jules
had worked in the past
years and on the way over;
Vasanth 4S7VC; Ernest
4S7EA; Guru 4S7PG; and
Paddy 4S7PB.
The following are ex-
cerpts from a tape record-
ing made in John's home
on August 14, 1977, of
some of the hams who
were visiting with Jules.
This first one, Jules said, is
Paddy 4S7PB.
"Right now we're here
with 457 hams, and Jules
W6YO is with us. He wants
me to say a few words to
start with, May I say a very
good evening to all the
gang in the Northern and
Southern California DX
Clubs, and I wish I were
with you as I was some
time back, ten years ago —
in fact. 1967 Wish you all
the best in good propaga-
tion for the next umpteen
years. Bye-bye."
''Good evening, my
brother hams in California,
This is Ernest 4S7EA with
Jules and my brother hams
here at 4S7JD's shack I will
say '{couldn't catch the
phrase)' to you all Which
is, in our own lingo, 'May
your life be long/ That is
how we say it. It's very nice
meeting Jules and I have
had the pleasure of
meeting many W6s on
Charlie Willie. I look for-
ward to meeting you once
again, especially my friend
Jules, when he goes back
home. Bye for now. 73/'
"Hello boys, this is 4S7
Baker Charlie speaking. I
was very happy to work my
good friend Jules some
days ago. He's my own age.
Vw very happy to know
that (laughter). Our rigs, as
you know, are mostly
home brew and mine is
also a home-brew one. I've
been getting quite a
number of stations with
really good signal strength.
Wish you all the best till we
possibly meet you on the
band again. Cheerio/'
[4S7SW) ''Hello, my
What you see is almost all of the town of Dzaoudzi,
Mayotte, Frer)ch Comoros. It was here in a tittte 8-room
hotel where }ules operated with the call of FH0YO.
143
friends in the United
States, I've been having a
nice time with Jules over
here. There are altogether
about seven hams here;
we're all having a nice
time. That's about all from
here. I'll pass this over to
my good friend, Victor
George."
''Good evening, friends,
this Is 4S7 Victor George
and we are having a very
fine time with old man
Jules here. I would hope to
meet many of the boys on
the air very soon, 73 and
wishing you an eyeball
from Sri Lanka. 4S7VG,
off/'
A couple of days later,
Jules was invited to the
home of Shanti 4S7WP for
a four- or five-course din-
ner that Jules said was very
delightful.
Shanti showed Jules a
VP9BM QSL card dated
1955. VP9BM is a former
call held by Jules when he
was living in Bermuda, "t
guess Shanti was my first
4S7;" Juies mentioned,
"and I was his first VP9. It
was great to see the card/'
He also had cards from
Don W6BVM and Leon
W6BYH from Delano,
Jules's home town. On top
of that was a Delano
Amateur Radio Club cer-
tificate, #45, dated 23 of
July, 1955, for working five
of the club members.
One day, at John's
home, Jules met Soma
4S7YL and her OM, Wick
4S7WA- They talked about
DXand she presented Jules
with an eyeball QSL card
and a kiss on the cheek.
Jules had also worked her
when she was 8Q6AC in the
Republic of Maldives.
Before Jules left Colom-
bo, John took him out of
town about 20 miles to the
Voice of America transmit-
ter site, one of several
located in different coun-
tries around the world.
Sfnce Jules had only
recently retired from the
VOA in Delano, this was
almost like being at home.
All visits to the various
countries and islands must,
sooner or later, come to an
end Many hams were met
on Sri Lanka, and the
memories will always be
pleasant.
After the Trader set sail
for the Maldives, Jules got
on the air and worked
some good DX. Contacts
were made with KZ5KN,
Canal Zone, and VP2MH,
Montserrat Another good
QSO was held with Bill
W7PHO, and later with
Father Moran 9N1MM, in
NepaL
The Trader dropped an-
chor at 5:15 pm on Thurs-
day, August 25, about a
half mile off shore at Male,
Maldives, an island group
off the tip of India, and on-
ly a few degrees north of
the equator.
One of the first things
Jules did was to check
about operating amateur
radio from the island, A
customs official told him
that no radio transmissions
of any type were allowed
from the island or from a
ship in the harbor. It was
strictly prohibited. Jules
was very disappointed.
With only 48 hours here,
one might as well enjoy it,
so Jules did a little shop-
ping and sight-seeing. He
also did some more
snorkel ing. He said the fish
were very beautiful, and
even got to touch some of
them. The water was so
clear one could see a hun-
dred feet away.
On the last day in port,
Jules went to the Telecom-
munications Department
to see what the re-
quirements were to get per-
mission to operate here.
Jules was "shocked" when
Mohamed Ismail Maniku,
Director of Telecom-
munications, gave him per-
mission to operate in the
Maldives Jules asked
Maniku if he would like to
become a ham. He said
yes. Jules said he would do
everything possible to help
him become an amateur
radio operator.
Jules asked if other hams
could operate from the
island and was told that
they could. There are no
customs or great for-
malities necessary.
Jules could have re-
ceived an 8Q call, but with
only a few hours remaining
before the ship left the
island, there wasn't time to
wait, so he was given per-
mission to operate as
W6YO/8Q, He worked all
continents within two
hours after returning to the
ship and getting on the air.
He would have liked more
air time, but the ship was
about to saiL
For the March, '77, issue
of 73 Magazine, I wrote the
article "Pttcairn Island-an
inside look at VR6TC" I
mailed a copy to Jules and
he received it in Tahiti,
Before leaving the
Maldives, he gave that
copy to Maniku. I'm sure
he read it from cover to
cover.
The ship left at 4:00 pm
and Jules worked a lot of
stations en route to the
Seychelles, He worked a
PY, 9Y4, VK, and many
Europeans, as well as many
stateside contacts.
In issue #8 of the Trader
Tales newsletter, Jules
wrote: "Good ole Uncle
Sam is at our service. Here
around the Indian Ocean,
CI 'hams' at Clark Air Force
Base and the Subic Bay
U.S. Navy base, both the
Philippines, and with the
U.S. Navy at Diego Garcia
in the Chagos Archipelago,
pass on to me the latest
weather data for requested
areas, gathered from
weather satellites. In the
Pacific, the Honolulu and
Guam satellite service was
even 'phone-patched' to
me directly from, and to,
the weather plotting sta-
tion.
"In the Indian Ocean,
this service was provided
through the generosity of
one particular amateur
radio station, WA4RQK/
VQ9, Jim, the operator
there, has been most
helpful; this is, I believe.
because we are 'Yanks/
"Another great service
we have all around the
world, and particularly
here in the Indian Ocean, is
the SEANET, which stands
for South East Asia Net,
with participating amateur
radio operators surround-
ing the 1 ndian Ocean, and a
'net control' station which
supervises all 'hams'
checking in, to offer any
possible assistance over
the air or to relay
telephone calls. This net
control station is being
handled by a most out-
standing and capable per-
son by the name of Carl
Reder S79R, who makes his
home in Victoria on Mahe
Island, Seychelles (our next
port of call), Carl can in-
stantly remember the 'han-
dle' of any one he has con-
tacted before, and there
are several dozen stations
who check in every eve-
ning.
Six days of sailing
brought the Trader to Vic-
toria, Seychelles. Jules met
Carl and spent a great deal
of time with him going to
various places on the
island. They visited a
religious high*power short-
wave broadcast station
and Jules stated that the
300-foot towers and anten-
nas were all out in the
water — a very unusual
setup. Jules even had the
opportunity to watch some
speedboat and yacht races.
An unusual treat for an
area such as this.
Time never stands still,
so the time had come to
depart from yet another
island. After getting to sea,
Jules made contact with
Jim WA4RQK/VQ9 and
received the weather
report for their trip to
Mombasa, Kenya He also
made contact with Ted
5Z40T, in Nairobi, whom
he hoped to visit upon ar-
rival. He talked to Ray
5Z4PR, also in Nairobi, and
was invited to stay at his
place for a visit He even
gave Jules two phone
numbers to call when the
144
ship clocked. Another con-
tact was with a Cape Town
ham whom he will meet
when the Trader arrives in
South Africa.
Once every 24 hours
while at sea during this
around-the-worid cruise,
Jules had to take the wheel
(helm) for two hours. One
morning white doing so, he
said, "We could hear birds
chirping away. I was
wondering, gosh, we're 500
miles away from land and a
bird's here?'' Later that
morning, someone saw a
bird up in lules's antenna
All of a sudden it dropped
and fell into the ocean
alongside the ship. No one
could understand what had
happened until they
looked up again and saw
one of the bird's wings
stuck in the antenna. Jules
said, ''It must have gotten
wedged in one of the cor-
ners of the wire and
fiberglass outrigger sup-
porting the antennas."
No matter where you
might be in this world,
there is always time for be^
ing a volunteer instructor
for Novice class students.
The Yankee Trader on the
high seas is no exception.
Jules started a Novice code
class with three students,
and every afternoon at 3
o'clock he gave three*
quarters of an hour of code
practice. All of his
students, at this stage of
the trip, were very en-
thused about getting an
amateur radio operator's
license. Jules said they
were doing pretty welL
When the Trader arrived
at Mombasa, Kenya, many
of the passengers headed
for the interior to visit
some of the preserves and
parks. Jules headed inland,
also.
When he took the bus to
Nairobi, he had hopes of
seeing 19,340-foot Mount
Kilimanjaro in Tanzania,
near the border of
Kenya. Unfortunately, the
weather didn't cooperate;
it was overcast The trip,
some 300 miles, was on a
narrow bumpy road. The
dust was terrible. Jules ex-
pected to see numerous
wild animals, but only a
few were actually seen.
When he arrived in
Nairobi he called Ron
5Z4RC, and later they met.
Ron took Jutes out to their
coffee plantation where he
meet Philomena 5Z4PC,
Ron's XYL. He got some air
time and had a long QSO
with a close friend, Frank
W6KPC, on 15 meters.
Jules said, ''He had a very
good signal, but no other 6s
were heard/' He enjoyed a
hot bath and delightful din-
ner Phil had prepared.
The next day, in
downtown Nairobi, Jules
met Ted 5Z40T, and they
had a very nice chat. While
here in town, he said he
walked so much just sight-
seeing that his feet
became sore and swollen.
He also took a four- to five-
hour tour of a wild game
preserve 20 miles from
town. He left that night for
the return trip to Mombasa
and tt rained most of the
way back,
Jules had purchased an
antique brass washbasin
(he called it a spittoon] as a
souvenir and was carrying
it when the following oc-
curred about a block from
the gate to the docks;
"A fellow came up from
behind me and grabbed for
my wristwatch. With both
hands, he pulled down, but
I didn't have an expanding
band and it wouldn't come
loose. I gripped it and held
on when it slipped to my
hand. He pulled me over
and I fell to the road, tore
my trousers, and got a
bruise on my knee, tt
scratched my wrist, too,
from the sharp wristband. I
swung at him with the spit-
toon, but I missed him. I'd
liked to have dented his
head wrth it He ran across
the street. Luckily, I got
away without getting
beaten up or having my
wallet or camera stolen."
Jules reported the inci-
dent, but that's about all
This is Cape Agulhas, southernmost tip of Africa. The
unusua! feature is in the whitecsp water seen between the
rocks. It is the dividing point for the Indian Ocean on the
left and the Atlantic Ocean on the right.. .
that could be done. It was
quite an experience, ex-
pecially when you're about
to leave the country and
head for another port.
Two days out of Mom-
basa, the passengers were
treated to what you might
call "porpoises on
parade." It was a spec-
tacular display of por-
poises, mostly in front of
the ship. There were hun-
dreds of them leaping in
and out of the water in
their acrobatic swimming
and playful jumps.
Since the Trader arrived
at Mutsamudu, Anjouan
Island, Independent Com-
oros, in the evening, Jules
decided to stay on board.
The following day he took
a bus tour of the island and
saw many of the plants
from which perfume is
made. He even took a tour
of a perfume factory where
flowers are processed and
a liquid is extracted from
them. From this liquid, a
perfume is made. "The
tour," Jules said, "was
quite enjoyable." That
evening the ship set sail for
an overnight trip to
Mayotte Island, French
Isles de Comoros.
When Jules was in
Miami, he had asked the
captain about stopping at
the Comoros since it wasn't
a scheduled stop. The cap-
tain said he was agreeable
and would like to. In issue
#9 of the Trader Tales, j ules
wrote another short piece
titled, "Perfume Islands At-
tract Ham Operator."
"The Comoro Islands
were first called the Per-
fume Islands, for they at-
tracted perfume mer-
chants to buy the strong-
scented oil extracted from
the ylang-ylang tree
flowers.
"Today, the islands have
another attraction to the
hams around the world: a
rare island country* This in-
spired me to operate my
radio equipment ashore in
a small hotel overlooking
the bay at Dzaoudzi,
Mayotte. On September 26
and 27, in the wee hours of
morning, during fair condi-
tions, in less than five
hours, I made 318 contacts,
mostly with stateside sta-
tions. Many thanks from
myself, and I'm sure from
the lucky ones who made a
QSO, to Yvon Seguineay
for issuing me the license
and call FH0YO, AI Fox, an
American visiting Mayotte
who helped in the opera-
tion, and especially Cap-
tain Paul Maskell, skipper
of the Yankee Trader, for
stopping here."
Long before the Trader
145
Mac ZS1LK and jutes W6YO beside the Yankee Trader, docked in Cape Town, South
Africa, Mac is one of many hams }ules met while here in this very beautiful country.
arrived at Mayotte, Jules
had contacted Al
VP2LOX/MM1 by radio and
talked to him about getting
a license to operate from
the island. When the ship
docked, At was there to
meet him. He had received
the call of FH0FX for
himself and FH0YO for
Jules. They were all set for
an amateur radio DXpedi*
tion.
After a stop to see ACs
yacht and meet his XYL,
Eva, they headed for the
only local hotel (B-room)
and started getting things
ready for the special opera-
tion. They obtained a lad-
der to get up on the roof
and dipotesfor both 15 and
20 meters were installed.
The low ends were tied to a
rock down on the beach.
Everything was set up out
on the balcony.
The first QSO on 20 SSB
at1200UTC [3:00 PM local
time) as FH0YO, Mayotte,
Comoro Islands, was
W3NX, 5X7 both ways,
followed by YB0AAU.
W3LMA, and then W3KT.
The first hour produced
nearly 60 QSOs. Jules said
he worked into Central
America very well, but on-
ly picked up one station in
Australia. It was Merv
VK4MW, whom he had met
several months earlier dur-
ing a visit to that country,
Most of the QSOs as
FH0YO were on 20 meters;
a total of 228 contacts
were made
Operation on 15 meters
was with the call of FH0FX.
There were 90 contacts
made here before the band
folded. Jules stated that
most of the stateside con-
tacts were from the 3rd,
4th, and 5th districts. He
missed ''Worked All Con-
tinents" by one: the one
closest to his location —
South Africa.
"1 was working spht,
transmitting with an FT-101
down on 14.195 and tuning
with the Atlas around 200
to 220. Later in the
evening/' Jules stated, "I
was tuning above 275, still
transmitting on 195,
"I even worked a station
running 1 Watt; W80K got
me to stand by for him. The
station was W8ILC. It was
something. He was 3X2.
"Most of the reports we
were giving were 5X7, We
received some 20 over S9
reports, with 20 meters be-
ing much better in signal
reports than 15."
I personally don^t know
if any other hams have
gone to Mayotte and
operated, but from the ap*
pearance and success of
what Jules did, this sounds
like an excellent spot for
an extended DXpedition.
The Trader was here for
less than 24 hours and they
did pretty well with what
time was available, thanks
to Yvon FH8CY, Director of
Telecommunications, who
was responsible for issuing
the calls.
After leaving the island,
the Trader sailed toward
the Juan de Nova Island
group in the Mozambique
Channel. From there, they
turned and headed for
Tulear, Madagascar. When
the ship arrived, Jules went
into town but didn't do too
much. The next day, of-
ficials restricted everyone
to the ship, so the follow-
ing day they shoved off for
Cape Town, South Africa.
At this point in the trip,
Jules mentioned that the
three Novice students he
had were doing pretty
well — about 5 wpm on the
code. They would be ready
for their tests by the time
the Trader reached South
America,
The bands were very
good here at sea. He had a
QSO with Bill ZS1ER,
whom he had contacted on
other occasions. Jutes
planned on visiting Bill
when the ship arrived in
Cape Town.
Another contact was
with a ham at 37,000 feet.
It was Fred W7UKC/AM3
aboard a 747 en route from
Seattle to Tokyo. He was
somewhere between Alas-
ka and Siberia. It was a
good, long QSO.
"Oh, it was a beautiful
sight,'" Jules said, "coming
in to see Table Top Moun-
tain, Lion's Head, Signal
Hill, and the terrific skyline
of Cape Town. The large
buildings could be seen for
miles and miles. It is just a
tremendous-looking city.
The harbor reminds you of
Rio de Janeiro; kind of a
round horseshoe bay. Fan^
tastic! There were dozens
of cranes about 200 feet
high, and large tanker
ships. You couldn't count
them all- It was nice to get
in
tf
It was Sunday morning,
October 9, when the Trader
moved up to a pier near the
yacht club in Cape Town.
"Believe it or not/' Jules
said, "'on the dock was Bill
ZS1 ER. He was the first one
to shake hands with me
before we even had the
gangplank down/'
Bill, along with his XYL
and two boys, took Jules
down the coast to the Cape
of Good Hope and Cape
Aguthas, southernmost tip
of Africa, for a nice view of
the country. They had a
really nice day and even
drove to a hill and saw all
the night lights of Cape
146
Town. On another day, Bill
and his family took Jules
up the coast for an all-day
trip where he met Mac
ZS1LK and family. Jules
stayed at Mac's home and
they got in a littfe air time.
Mac is quite active on 2
meters as well as the HF
bands.
Jules said Mac has a lit-
tfe two-year-old son, Jamie,
who really took to him. He
said, ''We really made
friends — the cutest little
fellow you ever wanted to
see.'''
Mac took Jules to the
yacht club, where a lot of
people asked him a
number of questions since
he was from the U.S, White
they were there, 'The first
leg of the around-the-world
yacht race from England
came in," Jules com-
mented. "There were some
beautiful yachts."
Jules also met Dick
W60Z, the radio operator
off a large freighter from
New Orleans. Later, Jules
took him aboard the Trader
for a visit. They even had
breakfast aboard Dick's
ship one morning.
Another ham Jules met
was Danie ZS1X. He went
to his home which was
right on the beach, A very
picturesque location.
Danie does a lot of ex-
perimenting with ham
equipment. His XYL was
about to get her ham
license.
The word apparently got
out about Jules being in
Cape Town, and a lot of
operators wanted to meet
him personally. "I met
quite a few hams. They
always seemed to be com-
ing around. There was/^
Jules commented, "a con-
tinuous stream of them/'
Jules was impressed with
the modern buildings in the
city. He mentioned that
they have modern free-
ways and overpasses. The
train station is as beautiful
and more modern than
J u les had seen i n the states.
This is a very progressive
city. The people were very
polite and courteous. The
shops had a very good
selection of souvenirs.
Jules even had a T-bone
steak at the Town House,
the first since leaving the
states back in February.
The dinner was a little over
$4.00.
"The hams here were
sure nice/' Jules said, "par-
ticularly Mac ZS1LK and
Bill ZSIER." Mac came to
see Jules off at 11 o'clock
on October 21, They had
some coffee out on the
deck while having their
final eyeball QSO. Mac
was one of the last to leave
the Trader before she set
sail for St. Helena.
It was some 1,700 miles
to Jamestown, St. Helena,
from Cape Town, South
Africa, Before the Trader
arrived, she had sailed
some 25,143 miles in this
10- month around-the-
world cruise. For Jules
Wenglare W6YO, it would
be another adventure in
yet another country. It
would also be a location
for another DXpedition for
Jules as ZD7YO.
In three parts, I have
covered eight months of
travel with Jules aboard
the Yankee Trader on the
high seas and the ports of
call visited. In part IV, the
Trader will sail another
5000 miles and stop at
another dozen locations.
Jules will meet and par-
ticipate with other hams in
celebrating 40 years as a
ham for Vic PY7AN in
Recife, Brazil,
On the island of Car-
riacou, Jules eats part of an
apple. Within a few
minutes his mouth and
throat began to burn. He
later learns that it was
poisonous. In fact, the tox-
ic apple has been fatal to
small children. ■
Nen^ Products
from page 23
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Morgan W. Godwin W4WFL
Peterborough NH
StNQLE IC SPEAKS
RANDOM MORSE
Using the new Curtis 8046
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The 8047 requires one exter-
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bevylz;aee73d;^
Variable extended spacing
between letters and fetter
groups is also provided for slow
speed study (characters at 13
wpm, words at 6 wpm, for ex-
Continued on page 158
147
whither Microcomputers?
a pro looks ahead
Chariene Bath Kmdie WB2HJD
316 Vanderbili Parkway
DixHiUs NY 11746
Computers are definite-
ly the wave of the
future. So says Hans
Napfel WB2ZZB, who
should know. Not only
does he work with them at
Fairchild, where he over-
sees 28 people, most of
whom are engineers, but he
also has been studying
them since the early 60s at
home, through all stages of
their development. And he
knows what applications
are planned for them in the
foreseeable future. No
one, he says, can be unaf-
fected by computers. They
are a part of everyone's
life, and this will be in-
creasingly true,
Hans designed and built
a small "dedicated" com-
puter (one restricted to per-
forming certain functions)
in 1973 It was built with
the best components
available at the time-
resistors, transistors,
capacitors, and some in-
tegrated circuits — and had
no microprocessor (a group
of integrated circuits
formed into a single com-
ponent). But most amateur
computing did not really
begin until more than a
year later, when 8008s — the
first microprocessing
chips — appeared on the
market. Now amateur com-
puting is a rapidly-growing
hobby, one which Hans
nevertheless believes is
still in its infancy- (The fact
im
A commercial microprocessor. This type of simple com-
puter will soon monitor the condition of your car.
that the "Personal Com-
puting '77 Trade Fair" at
Atlanta drew 140 ex-
htbttors and more than
5,000 people on its first day
bears this out.)
The personal computer
is industry's answer to the
general demand for in-
volvement with com-
puters. It is diminutive in
size, can read from
already-prepared tapes to
carry out a program, or the
operator can write in his or
her own programs.
Technical people will
find computers extremely
useful as a tool, Hans
believes. Indeed, it was
Hans's technical needs as a
radio amateur that created
his interest in computers
and caused him to begin
working with them. ''Now/'
Hans says, 'my computer
runs my radio station/' Not
the limited-function com-
puter of 1973, but a second
model, built in 1975, which
Hans affectionately calls
"The Blue Max." It is a
general computer, pro-
grammable for many
things. The Blue Max
(which is named for its at-
tractive azure front panel)
takes up less than a square
foot of space (quite a con-
trast from the behemoths
of the sixties, which were
also awkward to use). Max
can provide automatic-
repeat CW when Hans
wants to run a test. It
makes contact with a
Inside "The Blue Max.
##
3 148
The uncompleted new computer, contain mg $2000 worth
of modified commerical boards.
friend on schedule, with or
without Hans's presence,
and records the Morse
code answer received,
which it prints, in words,
either on the attachable
television screen or by
radioteletvpe, or both, as
Hans has instructed ft
prints the received
message at exactly the
same speed as the sender
gives it.
Hans's computer is
helpful to him in other
ways with amateur radio It
keeps track of his QSLs for
him so that he does not
have to wonder whether
the contact he's just made
should be asked for one. (A
bulging QSL file shows
why this is helpful!) It
keeps track of call- letter
changes. And it can be
asked to print out all the
"Charlies/' all the W5s. or
whatever.
Indeed, with a capability
of handling 200,000 full in-
structions (not bits) per sec-
ond (yes, that's per
second), Hans's computer
can be asked to remember
anything Hans uses it dur-
ing contests to keep his log
and to eliminate duplica-
tions in the log, "It is
also useful for field days,"
he says, ''to keep you
from repeating stations
worked/'
Hans also recommends
computers as a good way
to practice Morse code.
For not only does the com-
puter send perfect code
every time, at whatever
speed you desire, but it
also can show you the dots
and dashes on screen
simultaneously, thus giving
you the benefit of involv-
ing two senses instead of
jyst one. And it can be pro-
grammed to increase the
speed gradually, if you
wish.
There are other in-
teresting computer ap-
plications for the radio
amateur. For instance, the
moonbouncer will find it
"indispensable/' Hans
says, to keep the antenna
positioned at the moon.
When a ham with a
parabolic dish is not at
home, a computer can
sense the weather and
wind and rotate the dish
for the least amount of
wind resistance.
Hans and three of his
friends are working on an
even better computer than
The Blue Max. It, too, is
homemade, but is corn-
Hans 's computer terminal Model 33 ASR punches out a
taped program.
posed of commercial
boards that the four men
have modified. (For Max,
Hans designed even the
routine things.) Hans and
his friends are taking care
to program their com-
puters the same way and
with the same language
(they have settled on
"super BASIC"), so that
they can exchange pro-
grams and communicate
with each other effective-
ly. The computers can use
audio cassettes as well as
paper tape. Punch cards,
Hans says, are almost ob-
solete in personal com-
puting. (In addition to
paper tape and punch
cards, Hans's computer
can work from a ''floppy
disk/' with the addition of
a floppy bit memory unit.
This attachment records in-
formation on a flexible
record called a "floppy
disk/' and thus gives Hans
quick access to what is
now peripheral-memory
material, freeing space in
the computer's central
memory. These disks, too,
are transferable — easily
mailed.)
When this system is com-
plete, Hans says, it wilt not
only run his radio station,
but his whole house as
well. Already, Max orga-
nizes important dates for
him. It tells him when to
pay certain bills; it will
monitor the water
temperature and control
the pump and filter of his
in-ground backyard pool; it
tells him when to send
birthday and anniversary
cards and when to buy
gifts. How does it do this?
Not by waiting for Hans to
call up its memory. When
Hans looks i*to his
conveniently-located ham
room each morning, there
is the day's message right
on the screen — blinking to
get his attention.
"A computer can handle
anything to do with
numbers," Hans says. ''Us-
ing it unclutters your
memory and makes life
easier." Indeed. If Hans
should be late for a class or
fail to acknowledge an oc-
casion, it will not be
because he was not in*
formed! Max lets him know
the flagging date — the day
it is necessary to know — if
an event is coming up. And
Hans can call for a revfew
of the coming month, if he
so desires.
The computer is also
useful as a telephone direc-
tory. It may take a few
hours to prepare the pro-
gram, but to update it later
149 ]m
As Han^ taps out instructions, they appear on the screen at the top of the rack.
Simultaneously, the Teletype^^ machine on the left makes a printout.
will only take seconds. And
you can get the number by
first name only, last name
only, or even by call let-
ters.
Having a computer in
the home can be beneficial
to non-hams, too. Hans's
twelve-year-old daughter,
Claudia, uses it for games,
for educational math
workouts, and to make
musical programs She will
soon have a remote ter*
minal in her room- There is
already a remote unit in
the kitchen, where Hans's
Wife, Lisa, bones up on her
French.
But the computer can do
more. It can adjust the
thermostat in the house,
for instance. It could even
be made to do this "in-
telligently/' by monitoring
the outside and inside
temperatures and 'de-
ciding" how to adjust the
inside accordingly. This
could be important when
one is away, especially in
winter when pipes could
freeze, but when an Indian
summer could allow a
lower-than-usual inside
temperature. The com-
puter could also be made
to turn lights on and off,
water plants, feed the dog,
piay music, and control air
conditioning.
The family car will not
be unaffected by com-
puters. 'In the next two
years," Hans says, "cars
will have computers to
control gas mileage (by
noting speed vs. vacuum
vs. temperature and keep-
ing the car running at max-
imum efficiency by op-
timizing the fuel mixture)
and to monitor the condi-
tion of the car (letting you
know if a light is not work-
ing, for instance). In fact, 3
few cars even have com-
puters now/' Signals to the
driver will be shown on one
light-emitting-diode dis-
play, not by means of six or
eight meters as we now
often see in a car, A
computer-controlled warn-
ing system will sound a
buzzer to alert a speeding
or sleeping driver {erratic
wheel movements will in-
dicate that the car has left
the pavement).
Computers will even-
tually revolutionize gro-
cery shopping. One could
make selections at home,
visually (even comparing
prices from store to store.
right at your own kitchen
terminal), and then go to
the store to pick up the
waiting order Or it could
be delivered to your door.
Food, by this system, could
be dispensed directly from
warehouses. And com-
puters (microprocessors)
already control microwave
ovens and teaching ma*
chines.
But computers will
never make it big in the
classroom, Hans feels,
because ''teachers are too
threatened by machines.
Machines are potentially
author ity^shattering. What
if something goes wrong
that the teacher can't fix?"
Still, Hans feels that com-
puters could be used by
schools successfully as
tutors for drill and routine
work, if they are housed in
a separate room overseen
by a competent technician.
"But they will never
replace teachers," he says.
For handicapped peo-
pie, they will be especially
important, Hans says,
becoming the ears of deaf
people and eyes of the
blind. Already, speaking
computers like the one
owned by Pete Motyl
K1PXE can be purchased.
And in the health field,
they are already indispens*
able, but will become more
so.
"And by 1985 or 1990,
every house will have its
own minicomputer/' Hans
says. It will be used as an
"intelligent" security
system (those who live in
each house will not set off
the alarm), as a telephone
answering service and
directory (indeed, alt forms
of paper directories may
soon be obsolete), as well
as for energy management,
bookkeeping, scheduling,
providing educational
drill, and playing games
"What about using them
to communicate with outer
space?" I asked Hans,
His eyes twinkled at the
unexpected thought,
"They would be essen*
tial in a space colony," he
answered, "to monitor the
station's life-support
system and relative posi-
tions, and to keep track of
supplies. But to com-
municate with other in-
telligences in outer space?
Let me put it this way; I'm a
hardware realist/'
For Hans, thafs not a
limitation. "I keep up with
what's being discovered/'
he says, "and 1 just take it
one step further. That's
what makes the dif-
ference/' In fact, Hans ad-
vances the state of com-
puter art through his hob-
by, then takes his
knowledge to the job,
where he educates others-
In a pursuit requiring
perseverance and thor-
oughness, Hans's phi-
losophy is clearly the one
that works H
]m 1
50
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-B^^
SSTV Meets SWTPC: Part 2
micro-enhanced pictures
Clayfnft W Ahrams K6AFP
1758 ComsiQck Lane
San Jose CA 95124
In the first part of my
article, I acquainted you
with the hardware PinA the
basic concepts. Now, let's
discuss the software,
The 'loftware was the
most complex part of the
project hut the most fun. I
think the most important
point I should make is that
the software i*t a replace-
ment for hardware logic.
The use of software is more
repeatable and reliable
than hardware logic.
Another point is that the
timings are very rritiral, If
yon try to execute thjQ pro-
gram op another 6800 sys-
tem without a 17971 MHz
clock crystal, changes will
have to be made I will
identify the memory loca-
tions which will have to be
altered If the clock is
much slower than the
SWTPC the program may
KNHIINCB ••TU PKOCRAH
NKCATXWK
M
TRANSH I T
HOIS
PRIN
THIS ROUT IKE 3
PROGIMH CHHAHCCnCNT
not work.
The programming was
written with a top-down ap-
proach, with the extensive
use of subroutine calls (J SR
and BSRl The frequent use
of up to 4 nested subrou-
tines was used This
makes the program easier
to write, debug, and
r-hange Additionally, self-
modifying code was used.
If you plan to install this
prngram on PROM, don't—
unless you plan to execute
it elsewhere in RAM mem-
THE 8STU
OPTIONS
M
ory. Selfmodifying code
means that as the program
executes, it changes ftself
This type of code is dif-
f icult to debug, but the end
result is that a program can
be written to run in less
memory All subroutines
using self-modifying rode
restore themselves upon
completion. So don't hit
reset in the middle of an
operation unless vou are
willing to reload the pro-
gram
Another concept used is
to call certain routines fre-
quently. This also makes
sense and saves memory A
typical routine called fre-
quently is DEL2 which is a
program delay whirh is
used to transmit pixels. A
few large blocks of
memory were left free for
expansion. Fig 1 shows
how memory is organised
Locations below address
101 were left free because
of the d inert addressing
capability of the 6flOO. This
could be very useful in
future enhancements,
I wil! discuss each of
these routines or\ an in-
dividual basis, and explain
how the algorithms work
But first, a few basic ron-
cepts should be discussed
152
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TEST - APC
RECEJVE PICTURE
PPHiN ~
Pfl(NT PICTURE
fRA>*S'
TRANSMIT
PICTURE
NEGATIVE PICTURE
e4H
am*
tiAQHiFt Kt
COKT-
ADD CI>WTEtAST
fHOfSE-
REHOVE NOISE
LOCATIONS tNEJt)
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0101
04 S9
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02^4
9i«4IP
tMirl
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NOT ySEO
PICTUWE
PfXELS
#vci
fig. J. SSrV program
memory map.
Programming Concepts
The most important con-
cept to understand is the
programming format of the
analog interfale. Fig. 2
shows the bit structore of
the PIA ports, and which
bits are used to control
various functions. As you
can see from the format,
the program will only func-
tion properly with the hard-
ware connected to correct
PIA bits is shown in Fig, 2.
The other concept which
must be understood is the
format of the pixels in
memory. These concepts
are used throughout the
subroutine descriptions
and must be understood to
code the program in
another language.
Ptx£L m Mf€¥affr
LllVTl
ttlOH
ORDER
ORDCft
Subrouline Descriptions
The following is a
description of each major
subroutine used The
routines will be referred to
by their program labeL
Test
This routine is by far the
easiest to understand. This
routine can be used by
entering an analog input in-
to the special analog card.
u
If you apply 0 volts and hit
a number key on the com-
puter keyboard, a zero
should appear on the TV
screen. Also, an SSTV fre-
quency of 1500 Hz should
be generated. If 4.9 volts is
applied to the card, an F
will appear on the TV
screen, and a 2300 Hz fre-
quency will be generated
when a number key is
pressed. If a nonnumeric
key is pressed, the program
will return to the monitor.
The flowchart for this
routine is shown in Fig. 3,
PPRIN
This routine prints an
ASCII character picture of
the pixels in computer
memory. The program is
written for the SWTPC
PR-40 printer This printer
has only 40 columns. In
order to print a complete
SSTV picture, 120 columns
were printed on three
pages, and every other line
(64). When these three
pages are joined together,
a complete picture was
formed, A total of 7
characters was printed,
which represent the 16
gray levels of a picture. I'm
sure the character selec-
tion can be improved
upon. The selection was
subjectively chosen, with
little experimentation. One
point was clear: A char-
acter for each gray level
was not the way to go. This
technique produced poor
picture quality. Fig. 4
shows a flowchart of
PPRIN. Table 1 IS a list of
gray level vs. character and
memory location. This
table allows the user to ex*
periment with the various
ASCII codes.
TRANS
This routine is used
throughout the program to
transmit regular and en-
hanced SSTV pictures. The
routine is easy to use. Once
selected, a message ap-
pears on the screen which
asks for a keyboard
response of 0 to F, where 1
to F will be the number of
t
CA£
'Wt«
LS©
m% twpuT
PtM 4 Sf0£
OUTPUT SlGtt^ALS
?¥NC Bit hORezoNTAL
a,HD VERTICAL
{S5TV MOOULATOftJ
START ftDC
CON VERS ION
CB?
1
w^m
Lse
*0C OUTPUT
HDRtZOHTAL Smc PU.^1
«»tlC«l. STMC PtJt.SE
i
SAUPLE/HOUt
^TAIIT
F¥tOm SSTV RECEfWEJt
/V4 S sfne
[
itlPUT SlbNAtS
Fig. 2. SSJy enhancement program programmmg format
pictures transmitted. If 0 is
selected, the picture men>-
ory buffer will be filled with
a gray-scale pattern of 16
gray levels These gray
levels will appear as ver-
tical bars on the SSTV
monitor. This allows the
receiver to adiust his con-
trast and brightness. After
memory is loaded, the next
message asks for the num-
ber of loops for the trans-
mission. The response
should be 1 to F, where F is
15. This routine assumes
the 60-Hz SSTV video will
be transmitted. For those
of you who wish to trans-
mit 50-Hz video, the delay
constant at location 01 C9
should be changed from 20
hex to 10 hex.
This routine uses self-
modifying code, and six
NOP instructions were
assembled into the pro-
gram. These NOP are
modified by other routines
to enhance pixels and
allow a minimum duplica-
tion of code. Fig, 5 shows a
flowchart of the most im-
portant transmit routine, A
total of 7 subroutines are
used during the transmis-
sion of a picture
RECVPX
This routine receives
slow scan pictures pixels
and places them into mem-
ory. The routine is simple
to use. Once the option is
selected, the first message
which appears on the
screen asks if you wish to
17
dgrput
ROTfiPT
RIGHT
H4SK OFF
H4<;h err^
TF*h
TO
ASCII
PRI^T
OK
CfTt
(.OAO
I
WUAC
PIA
SWIFT
\
RETUIfH
7
fig. 3. TEST routine. Test
analog card rouiirte
flowchart.
Memory
ASCfl
Pfint
Gray
Location
Code
Character
Level
231,2
23 23
#
F.E
233.4
4F4F
0
D.C
235,6
5C5C
/
B.A
237,8
2A2A
«
9.8
239,A
3D 3D
=
7.6
23B.C
3A3A
M
23D.E
3A20
: space
3,2
23F,240
20 20
space
1.0
Table t Cray level vs. ASCII character value.
154
PFffm f
CilTT'H
LOAD PtCtUftl
tci
■w
fig. 4. PPRiN routine. Print
a SSTV picture flowchart:
CNT 2 = pixel counter and
CNT 7 = line counter.
receive 50- or 60-Hz video.
Your response should be 50
or 60 Upon the detection
of a vertical sync pulse by
the program, the 8K of
memory will be loaded
with 16k pixels in 8.3
seconds. One point should
be noted: The program
assumes that 128 Unes will
be received If the picture
received has less, the pro-
gram will continue to re-
ceive video until memory
is filled. Therefore, part of
the top of the next picture
\ "*'^'' / will be in memory if the
^ ' original picture has less
than 128 lines.
Fig. 6 shows the main
receive routine. This func-
tion is easily accomplished
by modifying the code in
TRANS to execute a Vs
complement of each pixel
before it is transmitted.
The transmit routine is
then executed and nega-
tive pictures are produced.
TffAf/S
COMMtEA
LtMLO l«T ivTE
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ftNlM
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MOP XJ
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SEND ffPBHLE
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5W»rf LEFT
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EKlH^llCCIIEKT
HOPS
TiKiii orr tf «c
J5R
Mt>F4lZ
I
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SITMC PULSE
RESET
CNT ^
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fig, 5. TRANS routine. Transmit a SSTV picture flowchart:
CNT8 = pixel count (64) and CNT 9 = line count (128).
Upon completion of this
routine, the code is
restored to NOPs in
TRANS. As a result, the pic-
ture in computer memory
is not altered.
BIN
This routine produces
binary pictures. Binary pic-
tures are a reduction of the
16 gray levels pixels to 2 If
the pixel in memory is 8 or
higher, an F gray level is
transmitted. If the level is 7
or lower, a 0 is transmitted.
The routine like BIN modi-
fies the code in TRANS to
jump out of the routine,
modify the pixel to 0 or F,
and transmit it. The code is
restored after execution to
NOPs. If you wish to ex-
periment with the gray
level clip level, the code at
locations 04D8,E7 can be
changed from 80 to
another value. Computer
memory is not altered by
the use of this routine.
In both BIN and NEC,
the program asks for the
number of picture loops
between 1 and F. If you re-
spond with a zero, the pro-
gram will loop 255 times.
To recover from this condi-
tion, hit reset and load a
low ASCII number into
CNT 10 (02F4]. Then type
G, and the program will
return after the count you
have just entered is
decremented to zero.
ZOOM
Zoom was one of the
most interesting routines
to code. This routine
allows selection of 5 loca-
tions of the picture which
wilt be magnified by a fac-
tor of 2. The locations are
selected by answering a TV
message with the com-
puter keyboard by select-
ing 0 to 4. This zoom
capability allows magnifi-
cation of any portion of the
SSTV picture without the
use of complex hardware
which is used in commer-
cial systems. The zoom
locations on the picture
are selected in the program
by loading the index
register with the upper left
hand corner pixel address
and branching to the TRZ
routine (056D). The follow-
ing demonstrates how it
works:
1
A 1 4
1
aYTES 7H4«SI*fTTED
isrrw liwe i
A 1 A
1
^ H
&STV LIME Z
1
A 1 A
J 1
1
4 1 4
1
As you can see, all that is
required is to transmit each
pixel twice and then trans-
mit the same pixel line in
memory again. The resuU
tant picture shows con-
touring, but this can be ex-
pected.
The memory locations,
picture locations, and hex-
adecimal values are listed
in Table 2, By simple pro-
gram changes, you can ex-
periment on where you
would like to zoom in on
the picture. This routine
calls six oilier routines, and
Fig. 7 shows the TRZ rou-
tine which is the main
routine. Computer mem-
ory is not altered as a result
of execution of this
routine.
CONT
CONT is a routine which
adds contrast to the SSTV
picture. The routine func-
tions best when the picture
is very dark and contains
few white areas. The rou-
tine makes the picture
lighter, and if a high-
contrast enhancement is
selected, a binary effect
will be achieved.
When the routine is
selected, the first selection
will be the number of
transmit loops after
enhancement. After this
selection, the number of
times of enhancement is
selected [2 to F), Fig 8
illustrates the computer
algorithm used The
routine first finds the
darkest pixel value in a
routine called FIND. This
routine scans 10 lines in the
center of the picture for
the darkest pixel value The
155 ]m
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frg. 6, RtCVPX routine. Receive an SSTV picture flowchart:
CNT 3 = pixel count
dark routine then subtracts
this value from almost all
of the 16k pixels in memory
along with multtplying
the results by the enhance-
ment number selected
This new value is com-
pared to see if it is greater
than F. If so, an F is placed
in memory. If it is less than
F, the results are placed in
memory.
The bottom 8 lines of the
picture are not enhanced,
and since many pictures
are generated by scan con-
verters, this area was left
alone Fig. 9 is a flowchart
of the dark routine which
shows how some of the
calculations are made.
NOISE
This routine removes
random noise from the
SSTV picture received.
This is accomplished by an
averaging technique. Pix-
r/fjr
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Fig. 7. ZOOM Routine. Transmit a 55 TV picture with a2 X
magnification flowchart: CNT 8 = 64 lines/picture, CNT 9
= 32 bytes/pictufe tine, CNT 12 - tine count storage, and
CNT 11 = index register storage.
^ 156
HEIiOKT
PtKtt
H
H
fig. 8. i.nhancement selection.
els, as received by the
microprocessor, are aver-
aged together with those in
memory. By use of this
technique, random noise
can be reduced by the
square root of number of
pictures received. When
executed, this routine asks
first for the number of
noise pictures to be re-
ceived. A value of 1 to F
can be selected The pro-
gram will then ask for a
selection of 50- or 60- Hz
video. The response to the
query should be 50 or 60,
This routine also calls 4
other routines and the
main line routine is con-
tained in Fig. 10. This
routine is similar to
RECVPX in operation, ex-
cept for the averaging
routines Since more com-
puter overhead is used, dif-
ferent delay constants
were selected
MONIT
This routine is used to
select the program options.
Upon completion of each
routine, the program jumps
back into MONIT. The pro-
gram should be started at
the beginning of this
routine (OFOI), This is ac-
complished by loading
A048,9 with 0F01 and typ-
ing G, When this is done, a
menu will appear on the
TV screen, The routine
calls INIT (01 B6} initializes
DMmt
llf 1 c
MB
OAttHE&T
131
Uiiit-iUaflOUTtHt
Ml AH
Tig. 9. DARK Routine.
Calculate a new pixel con-
trast level flowchart
*t&iS£
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wmmf
OOUHf
FICTUfl£
SIAtT
JbDML^S.
fig. 70, NOISE Routine. Receive successive SSTV pictures
and average flowchart CNT 3 = pixel counter: *Value
was fine-tuned due to progran] overhead.
SSTV Enhancement i
Program Ob/ect
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the PIA. The PIA must be
tTiitialized tor the analog
card to function properly
Program Delay Cunstanta^
As discussed edrliei. if a
different CPU clock speed
is used, different progtdin
delay curistdiitb should be
used These constants are
as shown in Fable 3
These program con
stants are exactly like hard-
ware timers and snigle-
shots I selected them by
trial arid eirur. I luadt'd a
number into thern and then
vie^ved an SSlV picture
The number was then tuie
tuned for the best picture
quality
Keyboard
bntry
Me
niory Loca
tian
Value (IME)
Location
0
0526.7
1000
upper l/h cornel
1
052b C
1020
up pet r/h cornei
2
0530, 1
1810
centei
3
0536,6
2U00
lower \th cornei
4
053A,a
201 F
iower r/h corner
Table Z Memory locations vs. picture locations.
MIKBUG Considei^atiuns
The program dsj*umes
that MIKBUC will be used.
The following MiKBUG
routines were used
throughout the program.
E07fc — Output an
ASCI! character
StriiTg
El Dl— Output one
ASCII character
El AC " I nput one
ASCII chaiacter
The prog rani also assumes
the special Analog Card is
157 yj
plugged into the Mother
Board at address B010 in
the SWTPC MP-68. The pro-
gram address assigned to
the printer is 8018 (loca-
tions 02C3, 4 and 02 DO, 1]-
A fully-commented source
listing of my program is so
large that I could not ex-
pect it to be published. If
you wish a copy, send me
$8.00 to cover the repro-
duction and mailing costs.
If you are outside the USA,
please include more
postage for airmail, Also, if
you decide to write, please
include a SASE.
Acknowledgements
I would tike to thank
Mike Talent W6MXV for
his help in interfacing the
MXV^IOO SSTV monitor
and for his technical
review of my project. Addi-
tionally, I would like to
thank M. S. Schlosser, Vice
President of Spatial Data
Systems for providing a
copy of his Handbook of allowing me to refer to
Image Processing^ and it ■
Program
Program
Current
Program
Label
Location
Value
Use
MSEC1
0126
04
ADC conversion
MSEC2
01 C9
20,10 (50 Hz)
Transmit delay
PUL1
03C5
5D
Horiz pulse width
' —
03E6
IE
Vert pulse width
■^^
0200
OF
Missing horiz pulse
width delay time
01E0,070B
0716
29,20 (60 Hz)
RECVPX delay
—
0710,0716
07E6
18,13 (50 Hz)
NOISE delay
Table 3. Program delay constants.
Nei4^ Products
from pagt^ M/
ample).
Another feature is an analog
output to directly indicate code
speed in wpm on a 1 mA move-
ment meter.
For additional information,
write: Curtis Efectro Devices,
Inc., Box 4090. Mountain View
CA 94040, or cal I (41 5)-964'3136.
Reader Service number C90.
HEUER INTRODUCES
WORLD S SMALLEST DIGITAL
MULTIMETER
Heuer has announced the
availability of a microrninia-
turized digital multimeter, the
DMM 2000, for industrial field
service measurement applica-
tions. Introduced earlier this
year at the Newcom 78 show in
Las Vegas, the new instrument
is the smallest, thinnest, most
compact digital multimeter
available anywhere. It weighs
less than 3 ounces (or 80
grams), including probe and
batteries, and measures 100 x
40 X 14 mm (4" x 1.87" x 0.55"')
for the base unit, and 100 x 20 x
12 mm (4" x 0J8" x 0.47") for
the standard probe.
The LCD display assures a
high degree of legibility for on-
the-job service for computer
systems, business machines,
telephone exchanges, data
transmission systems, radios,
and TVs. The mstrument pro-
vides four measuring ranges
for every mode: dc up to 1000
volts and ac up to 700 volts, ac
and dc current up to 2 A, and
resistance up to 20 megohms,
with a typical accuracy of 0.5%
on the dc range.
Heuer was capable of de-
veloping such a small .multi-
meter because the company
combined the microminia-
turization used in its watch
manufacture with advanced
multi-layer ceramic substrate
techniques.
Two major technical features
of the Heuer multimeter are its
true rms (root mean square)
measurement of the ac range
and complete shielding against
rf and other types of interfer-
ence, which assures accuracy
and error-tree reading even in
radio and TV applications,
Another technical feature is the
special design of the probe and
hook for easy accessibility
while testing high-density cir*
cult boards, A choice of ac-
cessories, including special
probes for high voltage, high
current, and temperature mea-
surement, is also available.
The exclusive permanent
identification of the measuring
mode on the LCD display and
the remote control of measur-
ing mode and range on the
probe simplify operation of the
multimeter, and assure error-
free readout of the results. Up
to 100-hour battery life is pro-
vided for the DMM 2000 by four
small watch batteries of 1.5 V
each. An additional advantage
of the unit for field service ap-
plication Is its high electronics
reliability and sturdy mechan-
ical construction. The unit is
delivered in a handsome carry-
ing case which includes
measuring cable, spare probe
point, batteries, and fuses.
The DMM 2000, however, Is
not designed for professional
use alone. With this unit, the
electronics enthusiast has at
his disposal a measuring and
servicing instrument which
suits his requirementSp con-
sidering its ease of operation
and Sturdy construction.
The DMM 2000 marks the en-
trance of Heuer into the field of
microelectronic instrumenta-
tion. Heuer is a 100-year-old
Swiss pioneer in high-precision
chronographs, stopwatches,
and electronic timing devices.
For additional information,
contact: Hans J. Kueffer, Heuer
Time & Eiectronics, 960 South
Springfield Avenue, Springfield
NJ 07081. Reader Service
number H30.
SD-1 TWO TONE
SEQUENTIAL DECODER
A new product announced by
Communications Specialists Is
the SD-1 Two-Tone Sequential
Decoder. This product is micro-
miniature in size, measuring
just 1 .2" X 1.67" X .65^^ high, and
will fit all mobile units and
most portables,
It uses plug-in field-replace*
Commued on ^ag& 204
The DMM 2000 multimeter from Heuer.
-h
The SD'1 Two-Tone Sequenttaf Decoder from Communications
SpeciaTrsts,
M
158
Bearcat® 250 Features:
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dcproval roimg ' 1 Out hi^hcsi (luut^ grad* ta
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frur bunans
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mcinifof a cenafn frft^timvcv
■ Tlm»~ Brilliant digital LED cbcli— will di-ipby hcMJTt,
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chartMifl to di^trrmLrir ll'w iik^ actt^f frBi:|Ui!nE;l«')»
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• Scnnbler/TaiM Audio Outpat — Top utoet crypto
^4ph4 aucas^g;^ m^ bf iXi-iCiy^ mnd *i«ij4*li 6^
comocctifiy tbe Btfunror ISTf auc&D oidput mA to •
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ih# [SbHIwi^ 8ui«iW qI StMndmih. Daia Emypoon
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(THrif ID govemnvmi n>aiiitatirtg djipkatiofi* Wti«n
uwd a-aJti A biitterv p^jwuvt «Mpptv iind d E^pf TerotdcT
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•can 44.1lv4iti? lU tap4^ ftscETKriiifr by rmrtaie fontrul urh«n
4 bcdv mikfr" transmHi^orL i» r«pc«»ed
v: jn !(pi»d fcrr ckutiT monifonng o<l de57ivd nvquvrtcur^
e BJrdf r'LEHzkant— Av : i' - ' ''^ ^tij tcAtmet 'lockup"
liutU^KI, ^tf.dti-tl tllw«^ ^^btUHrt w«fl lil^ 0WK Bfty
tirofpmmm^ binf i«i!
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. hiiMin'l u^ithoy! i.ti'np"!S| ihtOUgh oU chJinnsli
• AulOEMtlc SqueJcJi f ii<!|t>(V'H3l squdch
rtulntiiflticfllly block* uiJl unvyfloled noise
■ Ditclmat Display— Sht>wiii frcfqu^n^ and channel
MLJiiibLr] iih •mA\ il^ [Uriiyriiiitiini^d function
• DetuNV Keyboard— MK)kiiri» frvi^ui^ncv ntid i^aturo
11'U'i Iniri e-iiiy lur 'Sirrpk' fai'ii^iafPfnLn^.
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•J:^- I il: ! .'Usd unThiiut jiljiuimugni Ciiciiiiny n
.1 rr ji:_j!i(i:iiWy jjlKjnifd lo i^^ch it«iuitricy mmufored
• &«l«cAv« Scaa Pfffiy Arfd* a iwo-wcond delA|r lo
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« Space A^eOrcultfiH-CtitiDTTi jnt^grarted drcuilk
a Botittut tradiiion m scaJitunij rjidius
• ftolJJfig Zierot—ThUi Btmcut Hxclusive t^lis yon ufhklh
L'fiflnin^ls your scanner in infmiltinug
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Imtn Communlcatlaiift tvlisctionlcsT thir LJL nnd
RZC cvrtilicAtLpri i3^>huni» j^u oJ qutaltty design >.%ftd
mtrmfAatirv
Thtn4uCiiiiiiiiiuii£athjin« Electronic* Bi±ari^ 250
fi 4[fl ifiCTtdibie i^nrtiii^ t^M^ M^tKfriit^ thv ic^flnifi^
profoitioiMl And the knoii)«dg»ible scanning cnlhu»i4a(
cent* fnonitonng cBpabtlitufit. more frc%iwifKy vvrulUify.
than any odKr ^cannrtng monifor avadalile today
ll 4c»«* patented Beo^ror mtegt^caj cmnidtrv, «o ihctif >
Dfvtf A crystal ta buy With pu&hbutlon emit, up lo 50
ch^iiiick can be- pto^^anim^ en hve banks^ ol ten
chanrMb eadi The keybcMud is eiaisy is cotnprshciHl
fimpli' tn u^e. All funcfiom Art; m^ianiiy displayed m
bnght UED numbers and leltifri
All j^rtigramm^d fruquencbi^fi and pertinenl scan io
9ttucU*>r\i &rs mfmurizud In an i^lecrronJc memotv ihAl
opflrflies tfVisn when (h*? untl is unplugged kom wall
pdWtfiHtharf! Is no need for batteries.
Not Ofity wHI th€ B^dJ'CO^ 250 capture mart Mflntilng
action, it will "remember" wh«f 6 and How ofien Lt htfard
thftl aciHin iVow it's ea&y to Idtntlf^ which bf^uvncy ts
yiwd fiu»t often [t urill searth aulomatically thfu^ugh a
Mkctfli ^ucncy nn§ii ^md m«mari2e m m scdfch
m«fiwiv up tQ 64^ activif bwpitncitt To determine what
frequencies ivere kmrid dining the search siorg rpodh.
smp^ (Hrih the lenfl buooit vtd they wiQ bs da|>l«y«d
□rw eH a tane Ptes& the enlcr Heiir bkI any of iJhmm
tittquinoB ^ entervd airtaciutic^ mto the ccon
iiieiTtmy
\
^
As low as $259.00
in quantities below
Bearcat' 250
Specifications
Fr«n»rricy R*c*piion Ran^e
VHFBanI t4bi74MHr
UHFBatsd 4K»5il2MH*
Ewtrndrd fT«qi>ency range
iifUFiui k,, lU u;r// alsci CUHPf iih-i* /i'ir^ciu'rii^
/rfiqwcni'fei i4/ltih U r^ducljon rrt nrrjiJWeH'ifjj
VriFBariii 12544 6 MH^
UHh Hand 399-420 MM^
Scanner Dfmen«Jon.t
(tl>^ Widir X 3' hfagh e 7%^ 0«ep|
Scanner W^lsht
[5 ptmntli^
Stiipplnq Wfighl
TKHOBHtUI,
iM' UL«ltJd^le April 1979}
llO-l 30 V #C iiO Hi. IS Wstti
]2>n Vdf H Watts
Aiidio Oufpuii
Al ]eAit 2 a Waits rms
Antenna
r^-k;NCii|]|ny (bupptfed)
Sean ftnte
15 Dt 5 chaniiub per second
S«naillvitv
g 4 itiKfovoki* lor l2dB SENAD on VHF
lufufa, UKF iMnd ^ghtly htsA
Selediwnv
BeRetth«n
Th« BC'2S0^* auds is irHre notie'ltee aod
srffcn Ids diucmion thssi Ihe B«^f(al ^It}
by 1 mmqtn cd 10 dB or ntom
The fiearrol 250 rejects imagvtTtfquimoes
by at k-aft S dB belter m aJl b&rtd% than
Connectoti
bt^uTTinl ijriit^nna £ind spie^kcr, AC (k
DC PowifFi AuKJllary control ojtpiH,
tape audio output
Accvaeorlaa
Vehit:Jti^ mixiniing bracket vid hatd^mtt.
AC &■ DC pouMT con&
The Cnwpiiiiilr 11111111 Etectroolc*"
Bearznt 250 ev«n lias an automabc counf
huMbon th«| rem^mbas how ollen Any Of
aftpeagrannned h'cqiiaiclesivneAelsvaled
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h^ you daermme ih« value of yciur hv-
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tj^erallysi^ich dndse-ize active fr^ut^d'^i
An importanl femurti for prok'ti&ionals
who must tnorutor a spedfbc frequ«ncv is
the priority channeJ. Channel 1 If desirifd,
whalev^r free|uency la programmed ftjrthis
ch^iiETi^J will bid i!id;npled every Iwu auccnds
anytime Ehe i>«it l> turned on.
nu
The fieorrof 2SQ has an auklAafy ouaput feature ufhich
can be programmed toactualeesttamAldiivifesftiche^e
light. Alarm mo^oT, etc
ONE-YEAR UMfTED WARRANTY
With voui Bvi^rrcii 2.^0 u.'i a-ilt ^I'lid all acces^cne^. n
compleltf idi of simple opera Ung InstruclJoneand a
one-y^ar limbed warranty, If s^rtfce iB evat required.
JLL^I finnci ^ur receiver to I'ltip i'it niir a|3proVijd naElonal
svrviicf^ t:^<nii.^rs When you piirchaaia yoiir scanner from
Communlf^ationj Electronlce. yuu'ri^ buying from
tlie worJd'e leader In no^cryetal iCinner*. WeVt! i»»ld
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NO OBUGA-nON^i DAY TMAL
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ADVANCEn YET Um:OMPUCATED
Besides all the advanced leattite^ rh^al p^t th«
Commtinicatkraa Elcctfonlct'^ Bemcat 2S0< light
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Beartat'i patented irack tuning insures full banti
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Th4 ClHnmunicAtioa& ^WyttomJ^cm" Bearzat 2S0 n
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pjeAi^i^ 4<td 4% ^ale5 taK} Forei^jn Hjrders invited al d
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ordering Fu rth er price discuunts arc aval table to quiinHly
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Beorcof 2&04@ 1309 00, 12 unas @ 299 00. 24 untlf
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159
A Multi-Memory
Morse
ine
using a Motorola micro
Kenneth D. Leinmger WABTIW
inOI Puaon Sl
Utka MI 48087
This program, a dual-
function aid to sending
Morse code, was written on
Motorola's MEK6800D2
evaluation kit Not only is
the function useful, but
valuable experience is to
be gained in writing a pro-
Dor ^ ' ?
fi
Pi A
i
DftSM
MESSA(iE 9
-D P-
WtSSAGE: 4
-c «-
¥ESS4fiE a
-fi a-
■«ESS4££ Z
C^
-fl s-
■KSSAbE I
rt
OOfPUT
gram which exercises the
PIA. (No matter how large
or small your system, you
can't "control the world"
without first stirring those
I/O lines to lifel)
As previously indicated,
this program does two
jobs: It emulates the logic
of an automatic keyer, and
also allows the fully-
automatic transmission of
one of five prepro-
<ZI KiVEB
Pi- 6
fh
pe-4
^B J.
Pb-t
PB I
m
^^
Kl» ^ {
f WQ
MC
-r
fig. 1. Code system schematic diagram.
^
grammed messages. All
eight lines on the "A" side
of the user's PIA are uti-
lized; two for the dot and
dash contacts of the keyer,
one for the output to the
keying-reiay buftei, and
one for each of the five
message*select push but-
tons Fig. 1 indicates how
simple a schematic be*
comes once a micropro-
cessor system is used to
displace combinational
logic.
The program runs in the
256 bytes of RAM provided
in the "barefoof ' kit, but
L£tTUI "^^
Fig- 2. System initialization.
expansion of the kit to 512
bytes by adding two 6810
chips in the sockets pro-
vided is necessary for the
message buffer, Of course,
one could utilise the op-
tional HUM areas on the kit
once the application and
messages were suitably
developed
Ifiifialization
The program is executed
at location 001 D As in-
dicated by Fig. 2 and Pro-
gram A, the PIA is con-
figured, then the letter "k"
is sent to acknowledge a
functioning system Just
how the dits and dahs are
formed will be discussed
shortly. Each PtA line as-
signed as an input looks like
a standard TTL input com'
plete with internal pull-up
resistof Bit 0, the output
line, has insufficient power
to directly drive the keying
relay, a problem easily
overcome with the use of a
common-emitter amplifier.
160
CED
tfT;
T|S
XB
H3
JfTS
5^^ Its
VE5
rts
f>0— *■
tfS
Q«— »■
TE5
POINT EFl
SET UA
— ^
XMTT
f /g. 3, /npt/f potting routine ftowchari.
Qq4
IMtlE
fflO B
C^3
QiT tiO Of
ELEMENTS
ffS
tti , ^iiioii(}si>Atc
Tl( , , I^HCtlUf l&lg
LNr,RMINT
ilT tfST
loi &
CHaBACTEff PONE
as*
LHiLJirJ
LDEJ.ATJ
.DELAY J
^Ei POP una
F^ mitt
CHAHAtTIJI
fig. 4. Morse code routine flowchart.
Character
Code
Character
Code
Character
Code
0
FD
1
02
AH
55
1
7D
J
74
Slash
95
2
3D
K
A3
Period*
06
3
ID
L
44
Period
54
4
OD
M
C2
Comma*
06
5
05
N
62
Comma
CO
6
85
0
E3
Question*
06
7
C5
P
e4
Question
30
S
E5
Q
D4
Wordspace
07
9
F5
R
43
Halt
00
A
42
S
03
B
84
T
81
C
A4
U
23
D
S3
V
14
E
01
w
63
F
24
X
B4
G
C3
Y
94
H
04
z
C4
r S 5 4 3 2
NDW CHARACTER IS tMCODEO:
I t 0 I |0 1 0 o|
Cl^fAftACTER FfELO
NO OF ELEUEAITS FIELD
tiM THIS EK AMPLE. Htn '04'. OH LETTEiR 'Q' l^ SttOltN)
r 6 5 4 3 £
0 0 0 0
Q 1 t 0
r
0 1 C 1
0 10 0
*^iiiiCTyATiOf4 ncouiit£s Two BTTES;
CL£li£ifT$ BYTE
CMARaCTEq BYTE
Ufi THIS IXAMPLE. HEX '*065*»% OR "PERIOO" IS SHOWNI
Fig. 5. Digitizing the Morse code.
PIA Polling
This portion of the pro-
gram, illustrated in Fig. 3
and Program B. reads the
input lines of the PI A (bits 1
through 7) and then se-
"TRANSlAlf" SuenOUTlME
C ■■" )
Plh BIT Q
ZEno
NOt JtPKJ
sEwo ftrntM
IDEL4.TJ
SE%0 OQiT
^ _
ltCl4.¥J
^QELAT" &uanOUT>NE
GiiED
F/g. 6. Transmit and delay flowcharts.
quentially cornpares the
bit pattern with each legal
pattern expected: five pat-
terns for the five prepro*
grammed messages, and
two for the keyer input. If
all inputs remain high, the
polling routine continuous-
ly repeats the check. If a
particular message is
selected, however, the
grounded input is de-
161 Um
LOCAflOK
m
ft
0h
0B
0k
0&
0f
20
22
2K
33
34
CiiSE
1100
USEL SYHBOL
I 'HE SET
MESSl
ME3&3
■ES54
MKSS5
BSKST
EL&EG
7P 8sa^5
66 !?1
B7 B)2f(^4
66 04
B7 6)2^5
C6 ft
5P
|lt> 000^^
irrtT
READTT
GLR CRA
LM A ifi^i
LDA A ^l^ii
STA A OAA
LDA B 1101
J5R DtIT
CLft B
JSH XMIT
I KG B
JSF TifIT
GCMH£1VT
POINTS Ti) SIAHT OF TfeTT 1
POINTS TO START UF TEXT tt
poiri's TQ sTAi^T ar tkxt 3
POINTS TO SIJ^liT CiF TKKT 4
P0IHT3 Tt> 5TAUT OK TKXt 5
pOUIT£fi FOR CUHHEUT CHAJt
ilT Test KASI^ ^tafl£ AfiEA
SLEMSHTS VEH CfCAW RKGISTEH
GLEAI* CHA
BIT 0 DK KIA LS OUTPUT
SET BIT 0 OF DM
SET HIT 2
a^LECTS PIA FKIilPtI REG
3ET 0 TO ^1
^KNO UlASTJ
CttlAH ACS B
3£|tD DOT
SST B TO 1 AfJAiN
SE«n !>AS11
Program A. System buffers^ vectors^ and mitialization.
LOCATiUfl
COTIB
C6 PE
LABEL
READ
:.YJ
ifiOL
comufc
3T
LDA
B nwK
StT HiSAIJ fc^ASH
39
r4 S004
Ami
B MA
AND riA INtU AC:^ B
30
CI PC
fESTl
CBIP fi #«PC
CyMFAftK l» Vint 'PVT*
3E
26 0fi
BflE
tfc:ST2
IP /, UO T^^;JT ?
4j?(
DK ^2
LDX
MJ'^iJSl
POINT TO WlESSAaK 1
42
2^ il
BRA
UOJJE
lillH ME^SAHl':
44
CI FA
TEST 2
GiiTF
B #fFA
COKPAHE B WITH *PA*
46
ze 0i
BPE
TE5T5
IP /t &> tp:st 3
48
BE A
LDX
MEiiS2
HJIHT TO HHSSA'JE ?
4A
^ ^
BMA
CODE
Run hessa:;^
4C
CI F6
fESfl
CKF
B #1F6
CCMPAEE B ilTll « F6*
4E
26 04
BHE
^£5X4
IF i', DO TEST 4
5|f
Q£ 06
LM
IIE5^3
POINT TO Ml-JKSAJE 3
52
2^ 21
BRA
CODK
BUW MESiiM'ft
54
CI EE
TEST4
CJ^
B rtfSEE
UCMPAi^E B (VI Til 't^E'
56
26 0A
BfiE
TJ-.ST5
IF /, Uy TEST 5
58
SB 0d
LDX
MKSS4
POINT TO WKiiSAUK 4
5A
20 19
BieA
CODE
i(UH tiUii^AtlE
5C
CI DE
TfiSfJ
CBfP
B #SDE
QOM'ikHK B *I1H 'DE*
5E
26 04
ffrg
n
I? ^, I» T&St 6
0
OE 0A
LUX
MI^C^
POIltT TO t^ES^^^AOE S
62
2«0 11
BRA
CODE
miir 1ESS/.GE
64
CI IE
TEST$
c»\F B i^ias
COMPARE B nm *m*
66
26 03
BI:E
TEST7
IP /, m Tli::T 7
68
5F
CLR
B
PltEP a FOLt "DIT"
69
BD 55
BSR
XIUT
TRANSMIT A "DIT"
m
CI 7E
fESTT
Ck.a
B ffZl^
L^aiWIAliE B iVWl '7E'
6D
36 C6
m4E
liEAB
IF i^, GO BAUK 10 Ifh^U
6F
5F
CT.R
B
HiEl' B FOM 'UAH' m^
7iif
5C
mt:
B
SbTTlBC^ TO 01
71
m 4D
s^
HOT
THAMSIOT A Mvt «*
73
20 C2
EHA
READ
go TO READ
THIS ROUriJiE POLLS THE PlA (BITS 1 TiiRU 7) AH]>
Bl^JTieiHffTE^ CUjJTHuL A;i jUjiCJiIOM OF uPEiWiUB
IKHJT TO THE PIA-
Program B. Input poUing routine.
tected, the index register is
loaded with the starting
location of the respective
message text, and then a
branch to ''CODE ' (loca-
tion 0075] is executed.
When the message is com-
plete, -CODE" returns ex-
ecution to the beginning of
the polfing routine. If the
keyer is operated, then the
dot or dash contact is
detected and Accumulator
B is respectively cleared or
set. This accumulator is
then handed to the "XMIT"
subroutine whose job it is
to make nice clean setf-
completiog dits and dahs.
After a single dit or dah, a
"return from subroutine"
instruction returns execu-
Kl
PB'I through
PB-5
01
R1
Parts List
Relay, Sigma 65F-1A-12DC
or equivalent
Switch, push'button-type,
NO momentary-con lact'
HEP 234 or equivalent
1k, V4 W
•Note: Because relay is energized during system reset, the reiay
output is taken off the normally closed contacts.
LOCATIOH
75
7?
79
7B
71)
7F
81
63
65
87
89
U
Be
BE
90
91
nj
95
96
98
9B
^D
H
A0
A4
A6
AB
AA
AC
AE
tXp
B2
m
B5
CQBE
lAHSi SYMBOL
C6 07
CODE
LDA B #$01
EA 0
m 0t
AKD 1 0^pX
STAB ELDEC
ca m
CMF B 1^7
27 i!&
HEq WHD3P
CI 0^
CMP B $06
27 m
BBQ IVMQT
CI m
2s m
WBB 900
BVE CtHtT
^"
^A H£AD
RJICt
IBX
DF 0C
COHT
STI CBHNT
B6 6^
97 p:
LDA A i^lBf^f
T£ST
STA A MSKST
5F
CLH B
A5 m
27 PI
BIT A 0,1
BEQ iilJB
5C
UlC B
BD aa
301
S5H Hilt
QEC £LBEC
BEQ CHRS?
96 0t
LDA A MliKST
44
LER A
UE 0Q
Litx indiJ-ii'
20 EA
Di^■ TEtiT
Bd 36
#RDSP
JjiDri DLLAY
BD i4
BSK DtLATf
bd yz
B£B DELAY
m 30
C3RSP
ESB DKLAY
m ZE
Kj\i DHiAY
BD 2C
BSil DELAr
DE 0C
LD3E CflHltT
0& ^
INJt
DF 00
STI CRRKT
20 BE
BRA CODE
GCM£EifF
MASK ACU B
GET PITS 0,1, AND Z
SAVE ff OF iiLKMENTS
SEVH^f ELETt"j;NT37
IF SO, W *0Ki>£FAC2
SIX KLEMEWTS?
THiOi KlRCTUAl t;jll
^EBO ELES^JPTSf?
IF BO, JXH1E.
CO back: to POLLIIiG
LOOK At HEX'S CHAR
SAVE IQINTEH
SET HIT 7 (MAyklUT)
SAVE AT HAirKljTOHE
GET HEAIJY FOB CODE
TEST A« ElrKLEHT
IF 0, DO DOT, IP 1, DO BASH
PREP "B" FOR CIIAR
EXECUTE E!*EIIH«T
a^E I.E£iS ELiCMEflt
IF ZEm, DO CHAR SPACE
GET MASK BACK
SHIFT mi TO HiGirr
GET I'OINTKH PACK
GO TO Tl^^f
SIX DELAY UIOTS
SENT BET#E .]J A'OKDS
CALLED BY "^7"*
THHEE DELAI DHltS
SENT APTEa EACi!
CliARACTEB
GET POIBTEn
IHCHEIitKrJT Pt/Et NEXI
SAVE POIKI-EH
GET HACK^ DO NEXT CEiAR
XBIS BOUflirE COItVEHTS A HEIABECIIIAL E]ICOIl£II
KRSi HESSA0B UrO REAL TIIIE ItQUSB Q<mE,
Program C Morse code roc/t/ne listing^
OiX^HF.^
LOCATION
CDDl
LABEL
STfUBCL
C0
86 PE
IMIT
]Vk
A #*FE
Ct
^^
AMD
A FIA
C5
^lA
A FIA
ce
5D
TSf
B
C9
27 04
mQ
LOT
CB
8D ^F
DASH
DSH
DELAY
CD
SD ^D
BSR
DKLAY
CF
8d 0B
DOT
BSR
DIllLAY
m
8^ £Jl
LDA
A n0i
Dl
BA Bim
ORA
A FIA
Il€
B7 dml4
STA
A riA
D9
8l» ^
BSK
DELAY
QB
39
HTS
DC
BE «l^
BELAY
LBK
PBESEt
DE
09
BEO
DEjr
DF
26 fD
BKE
DEC
El
39
KES
Program D.
Transmit and d
ItA^ Ai BIT 0 OFF
AMD FIA into A
FIA BIT 0 KPI LOJ
IP ACC B IS ^EHOj
EXEClfTE Dcrr
CfTHER-VISE BO A DASH
U DASH IS THRtK UNITS
LONGS A DOT IS OWE)
SET PlA BIT 0 BY
UTILIZTWO TIIE "OH"
►^lKi?TM>N
COHflETE THE BOT/lMlSi
HErUaii FH.« 5FSTilE
rUIS IS Tt!E DEUr
SUBRUJTIWE- VAHY CODEB
SPEED W MODIFY INC
X TRKaHT AT LOG 00,
tion to the polling routine.
Digitizing the Morse Code
The real challenge, of
course, was to teach the
machine to speak ''Morse."
Essentially, the system ob-
tains a character (a byte of
data from the message
text) and performs a bit
test, starting at the MSB. A
"1" is translated into a
dash and a "0" into a dot.
Knowledge of the number
of dits and dahs in a par-
ticular Morse character is
required in order to tell the
program when to stop shift-
ing the bit test across the
data byte. This is ac-
complished by indicating
the number of elements in
the three least significant
bits of the data byte. As
shown in the flowchart in
Fig. 4 and the listing in Pro-
gram C, the A and B Ac-
cumulators are masked so
that Accumulator B re*
ceives the number of
elements. Accumulator B
is then stored at ''ELD EC/'
a memory location which
is decremented every time
a Morse element is com-
pleted Fig. 5 indicates how
the Morse code is encoded
into the previously de-
scribed format, As usual,
exceptions exist, and they
deserve some explanation.
The format is useful for a
Morse character which
contains from one to five
elements. Punctuation re-
quires special handling.
Therefore, if Accumulator
B picks up the integer '06/'
M
162
then that particular byte is
skipped: The six-bit char-
acter is found at the next
location in the text Two
other special cases exist,
one for inserting just
spaces, and one for termi-
nating the message. These
sttuatrons. again detected
in Accumulator B, are il-
lustrated on the 'CODE"
flowchart.
Morse Code Generation
Subroutine "XMIF' (Fig.
6 and Program D) handles
the actual formation of
and output for the dits and
dahs. The timing for
character generation is per-
formed by a delay loop
located at 00 DC. The pre-
set value is conveniently
located at 0000. An initial
value of hex 1700 sets the
keyer and message
generator speeds at about
13 wpm. A dot consists of
one unit of time of output
"on" followed by an iden-
tical unit of time of output
"off." A dash consists of
three units of time of out-
put "on'' followed by a
single unit of time of out-
put "off/' The contents of
Accumulator B at the time
of the call indicate the
desired element (00 dot;
01:dash), The output, PI A
bit 0, is cleared to assert
output 'on". This prevents
a key down situation during
system reset.
Setup
Loading the messages
for the automatic sender
consists of converting the
text of the message into
hexadecimal and storing
it. (Armed with only an
evaluation kit, this is a
manual job!) The starting
address of each message is
then stored in the message-
vector area starting at loca-
tion 0002 The current pro-
gram can only support five
message vectors, but there
is no reason (other than
memory contraints) why a
multitude of messages
could not be stored; simply
changing a vector would
then pull a new text string
into the foreground. A
series of "Vs'' or the word
"test" repeated several
times makes a nice brief
message around which the
code speed may be opti-
mized. Fig. 7 illustrates a
group of encoded mes*
sages.
Operation
Start the machine by
executing at 001 D. The let-
ter "k" in Morse should
acknowledge start-up. At
this point, the keyer may
be used, or any one of five
messages may be sent by
momentarily depressing
the appropriate push but-
ton. Once started, a mes-
sage will proceed until
completion. ■
Message
Starting Location
Code
1. CQ CQCQ
0100
A4 D4 07 A4 D4 07 A4 04 07
2. DE WA8TIW K
0109
83 01 07 63 42 E5 81 02
63 07 A3 00
3. QTH IS UTICA.
0123
D4 81 .04 07 02 03 07 23 81
MICH. ES NAME
02 A4 42 06CC 07 C2 02 A4
IS KEN
04 0654 07 01 03 07 82 42 C2
01 07 02 03 07 A3 01 82 OO
4. EIGHT DJTS
0148
01 01 01 01 01 01 01 01 00
5. QRZQRZQRZ
0151
04 43 C4 07 D4 43 C4
07 D4 43 C4 00
Fig. 7. Sample message set.
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RON
{?I6)23S'77]6
Mon^Frl 1 0 to 3
and 6 to 9
|1M
(716) 25S 754D
y
Amateur Radio
of Rochester, Inc.
I 185 SconsviriF Rd. Rochester, New York 14614
^AS\
p^ R0a<ier Service— see p&ge 32 J.
163
"This is Your Computer Speaking''
how to dial up your micro
Completed modem number one.
^
164
Jerry Sorrels
6266 Banner Ct.
Riverside CA 92504
A modem, now that's
what I need for my
6800 system! But how
about one that has auto
answer? Auto answer lets
you dial up your phone,
and, when it rings, the
modem will answer and
connect your computer to
the phone line. Now you,
or someone else, can
operate your computer
from a remote terminal
and modem.
I decided on using Mo-
torola's MC6860 modem
IC, and being a tairly-
stingy-with-a-buck person,
its availability, features,
and $14.95 price are what
sold me.
After spending a week
thinking, i decided on the
features for my first
modem. It was going to do
everything the chip was
capable of This overkill
approach does have its ad-
vantages when you're not
positive about what you're
going to do with it or con*
nect it to.
Two months later, when
the smoke finally cleared, I
had built two modems.
One was a do-everything,
interface-toalmost-every-
thing, and the other was a
minimum parts version,
with most of the features.
This article will be about
a combination of my two
moderns which will have
the following features:
0-300 baud, self-test, full
duplex, originate and
answer modes, compatible
Inside view of my fir^t modem {nole ii]wrnat caupii^r board mounted ai angle to tit tn
case).
with various systems via
TTL or KS-2iJ levels and
auto answer and discon-
nect My total cost, for all
new parts, was under SJU,
including the case and
power supply.
Some Theory
This modem uses audio
frequency shift keying
(AFSK), da Id to be sent is
converted to audio tones.
If the modem is in the orig-
inating mode, a logic 0
(space} is sent as a 1070 Hz
tone (2025 Hz, if in answer
mode), and a logic 1 [irjark)
is sent as a 1270 Hz tone
(2225 Hz if in answer
mude); see Table 1. This
might seem a little confus-
ing, but it works just fine.
These frequencies are stan-
dard for low-speed data
communication.
This modem is com-
posed of several logical
sections. Fust is the inter-
face to the telephone com-
pany line (see the sche-
matic. Fig. 1J. This inter-
fai^e must be able to niatch
the characienstic im-
pedance of the phone line,
usually 900 Ohms, to tne
modem. It mu^t pic vide dc
isolation from the tele-
phone line and tu« auto-
matic answei. iTtusi bt able
to detect when the phone
Is ringing and be able to
answer and terminate the
calL
The filtei (see Ftg 2)
passes only itit; rrequen
cies 1070 Hz to 12/0 Ha
when in the dit^vvei mode
and 2025 Hz to 2225 Hz
when in the uiigmaLe
mode. The fikei is needed
because, in full dupltfx
operation, the niuoem is
transmitting and receivtng
at the same tinit^, and the
signals must be st^paraied.
The limiter, ICi, takes the
sine wave from the filter
and changes it into a syin-
metrical squaie wave of a
TTL-compatible level The
demodulator in the
modem IC cQiiipaies each
half-cycle of this square
wave against the crystal-
control led tiniebdse to
deteitnine if the ini.oming
frequency is a mark or
spcice. The Lhreshuid
detector, IC4, is used lo tell
the modem IC that the in-
put signal enttimg the
ir miter is above the
miniHium detectable level
The bdbO mud em K is
the biatns behind the out-
fit H lakes L^are ot modula-
tion deinodulatiON, and
the handshaking signals to
e^^-ibn^h, iTtdintain and
tern^itiate ttie data link
Anothei iectiuii i:> tht; m-
lertdi e to rhe compuiei ot
terminal. There is a fair
amount of tlexibility here
due to the btibO signal
levels Derng 1 I L-cumpati'
ble Ueptiidiug on the ex-
act use you plan fui the
mudtriii It can be tailored
to fit In jjiy cdse, I con-
verted soiiie of the signals
to Kb 232, ail OT them
could be ca*i vetted rf
desired
Huw n Works
It 1 IS placed m the
aiiswei mode when its pin
19 is grounded This is done
by the rin^ deiectof when
your phone rings ui by
pu:>hiiig the an^iwej switch
Thi> * au^es K1, pin 4 lo go
high operating RL1. which
166
TCtCPrtOME PLUC
fELCFMOUE
JACK
2N.390*
Fig. T, Main schematic with internal coupler.
connects the modem and
answers the call. At the
same time, ICl, pin 15 goes
low; this places RL2 in the
proper position to select
the answer mode filter.
When fC1 detects the mark
tone from the other
modem, pin 23 goes low;
this turns on the clear-to-
send(CTS)LED.
The originating mode is
initiated when the originat-
ing switch is pushed, caus-
ing I CI I pin 21 to go low.
Next, pin 4 goes high, clos-
ing RLl, connecting the
modem to the phone line.
At the same time, pin 15
goes high, operating RL2
and selecting the orig-
inating filter. When IC1
detects the mark tone from
the answering modem, it
will send out its mark tone
from pin 10 to the transmit
buffer, T1, and out to the
Une, Now the CTS LED will
light indicating "ready to
exchange data/'
If I CI, pin 16 Is held low,
the modem is placed in the
self-test mode. The demod-
ulator is changed to the
modulator frequency and
loops back to the terminal
whatever is typed in.
When a break (150 ms
space) is received by the
modem, 101, pin 3 is
clamped high and stops
data exchange. This posi-
tive-going level triggers a
one-shot, IC6, which sends
Data
Oflgfnafe
Answer
0 Space
1070 H2
2025 Hz
1 Mark
1270 Hz
2225 Hz
Table 1. FSK transmit frequency.
a negative pulse to ICI^ pin
9, automatically releasing
the break condition. This
negative pulse is also sent
to my SWTP 6800 comput-
er's MRST line. This gives
the remote terminal the
ability to operate the com-
puter's hardware reset by
sending a break.
Construction Tips
I built the modem on
four printed circuit boards,
consisting of the following
circuits: the internal
coupler, the filter, limiter,
and threshold detector the
modem !C and RS-232
chips, and the power sup-
ply. You can use whatever
construction technique
you prefer. 1 always socket
all integrated circuits. This
time I had to replace the
24-pin socket with one of
better quality; it caused all
sorts of problems, so be-
ware! I guess if I had
socketed the sockets, I
might not have had that
problem!
I made the ring detector
by laying an NE-2 lamp on
top of a flat cadmium
sulfide cell and using hot-
melt glue at each end of
the lamp to hold them
together. Then I wrapped
black electrical tape
around them to keep out
the ambient light The first
one I made didn't work. I
found that some NE-2
lamps require about 100 V
ac before they light. Next I
took apart a neon pilot
lamp assembly. It had an
internal 22k resistor in
series with the neon lamp;
this combination worked.
The series resistor, R3, can
be from 22k up to 220k,
depending on the wattage
rating of the lamp. Pretest
your neon-resistor com-
bination to make sure it
will light on approximately
70 V ac. I bought the cad-
mium cell at a surplus
store; it's about y^-inch
square and ^/i-inch thick
(any similar configuration
you can come up with
should work okay). There
are also commercial
neon/CdS modules avail-
able, such as the Clairex
DLM 3120A Photomod.
RL1 is an SPST 12 V dc
relay with a Ik Ohm coil,
mounted in a 14-pin IC
package. A suitable 5 V
relay could be used if con-
nected to the 5 V supply.
RL2 is a DPDT 5 V relay
with a 100-Ohm coil,
mounted in a TO- 5 paclt-
age. You should be able to
use any similar relays, In
my second modem, I left
out RL2 and just used a
DPDT switch, mounted
between the originate and
answer push-buttons. This
made construction a lot
easier, without losing any
real features.
IC5a is just used for in-
version to save a transistor,
I used a 500" to 600-Ohm
transformer for T1, The
ideal value for the side that
connects to the phone line
0^
166
is 900 Ohms. The side of Tl
connected to terminals A
and B can be anything be-
tween 500 and Ik Ohms,
but, whatever value it is,
Rl (connected to pin 1 of
IC2a) should be adjusted to
match it.
All the frequency-deter-
mining resistors in the
originating and answer
filters should be 1%. All
the 01 uF capacitors
should be 5% or better,
mylar or pofystyrene.
A lot of phone com*
panies require you to rent
(from them) a coupling
device when connecting
external equipment to their
lines. There are several
types of coupling devices
that will give the same
auto answer and discon-
nect features as the inter-
nal coupler described here.
One is a CBS data coupler
which has RS-2 32-compati-
ble signals. If you use one
of these, the optional data
coupler interface (see Fig.
3) is used in place of the in-
ternal coupler. This circuit
will provide the RS-232
levels needed by the phone
company's CBS data cou-
pler. Rl should be changed
to a 600-Ohm resistor,
because the customer
sides of their couplers are
600 Ohms.
Testing and Adjustment
The modem's hand-
shaking signals should be
tested first. Connect a
small high-impedance
speaker (100 Ohm) or fre-
quency counter to the line
terminals of the modem.
Turn on the power and
push the answer push-
button; you should hear a
2225 Hz tone. The level
can be adjusted by R2,
Next, connect an audio
oscillator across the
speaker and apply a 2225
Hz signal, push the origi-
nate push-button and, if
you left out RL2, change
the filter switch to orig-
inate You should hear the
modem send out a 1 270 Hz
tone, and the clear-to-send
(CTS) LED will light Next,
Buff EH
to TTRMlhAL
TO IC1
PIN ID
iC^fr
85K
WCDE
'FREQUtllCr DITfJl4fll*ll>ja Rt&ISTQfli
TO ICl
push the break push-
button; the modem should
send a 1 50 ms 1070 Hz tone
every time this switch is
pushed. Now push the
disconnect switch; the
modem will send a 3-seC'
ond 1070 Hz tone, the CTS
LED will go off, and the
modem will stop sending.
The transmit level (R2)
will be adjusted next. Dial
up a friend and have him
leave his phone off the
hook. With the modem line
terminals connected
across the phone line, push
the answer push-button
and hang up your phone, or
operate the line switch to
the modem. You have 17
seconds to measure the
signal level across the
phone line with an un-
grounded meter. Use the
output jack or connect a
Fig. 2. Filter circuit,
OA uF capacitor in series
with the meter and adjust
R2 for a level of -15 dBm,
0.14 V rms, or 039 V p-p.
Next have your friend
call you back, but, before
he does, the modem should
be on and connected to the
phone line, and, if you left
out RL2, place the filter
switch in the answer posi-
tion. When he calls, the
phone should ring once. If
it does, wait a few seconds
and pick up your phone.
The modem should be
sending out a 2225 Hz
tone. If the phone keeps
ringing, the ring detector is
not working.
To test the data section,
connect the data in and out
to something that speaks
RS-232 at 300 baud or less.
The modem does not care
about format; it converts
to tones anything that
comes into it. I used my
SWTP CT 1024 terminal.
Turn on the modem and
push the answer switch.
Turn on the test switch.
NowtheCTS LED will light,
and what you type on the
keyboard will be looped
back and printed on the
screen. If you installed the
manual filter switch,
change it to the originate
position (this is one of the
things that RL2 does auto-
matically). This is about all
the testing you can do until
you find someone else with
a modem or build two tike I
didi
Interface and Operation
I connected the modem
to my system by parallel-
ing it across the CT 1024
data in and out lines. This
167
]^
^0 tUS
!»i
•*i
p ^-^
E —
4 fUjiF
I
sti.im
f/g 3 Opvona^ CSS dara
coup/er inteitace
wa\ 1 1 acts like anather
teinMuai that r.an access
the riMiiputer over the
phone line
* dse the rrK»dt?fTt as a
teMantal orrlv like f'alking
tu d iinicihare t.uriipuLer,
just tonnect it to the ter
rniiial and disconcert the
rest ut the system
When usiiig rnodems a
poim to reiTieiTibei is that
one end must be in the
ofigmate and fhe other in
the doswei mude. ii doei
not really matter whit h
The hand-shakrng tones
i-dfi be lost to" up tLf I?
secundb beior^. the con
neLtion will be lust but
d^ta ieni whei. the CTS
LED IS off will be lost
During at li ise^ tr you
are the originating fnodem,
dial fhe number you want,
and n wU! he aoswered by
a perbun oi d modem If
you heai a tone vou have
17 ietonds to push yuiir
originate svv'ttch and hang
up or change vour line
swUch to the modem
Vvheii yuur niodenr detects
the tone, it will send out its
mark tone: then the CTS
LED will light, and the data
can now be exchanged
It you are calking to an
bVvTP computer who>e
MRS! line ts connected to
the reset terminal, sending
a break will reset the com-
puter to its Mikbug^'^
operatuig system Oper
dting the disconnect push-
button will cause the
modem at the othei end to
hang up.
Also remember that it
the muden^i js on and con-
nected to the phone line, it
Will answer all calls you
get It could be someone
not expecting to get a 2225
Hz tone in his eai and they
could report your phone
out ot order. Ihebesithmg
would be if you had a
separate phone line just tor
the modem.
For my acid test, I left
line mudem at home and
the computer loaded with
games: the other I took
tlOV«C
60C r a
i.Mi4ClT-l?
■<3]-ia
Fig 4 Power supp/y.
with my terminal over to a
friend's home I draled up
the computer, and we
jiayed games for tour
lours il worked greati
Imagine what I could do
with a floppy back at the
computer! I
References
1 Felsensiein, Lee. Build Pen
nywhislie the HobDyist's
Modern Popular Electronics,
March 19/6.
2. Laaaastar, Dori. TV fypewrif
er Cookoook
Z, Motorola MC6860L data
sheet.
4 De Lavne, Jon, ■*Lovv-speed
MoQem System Design Using
the IV*C68bO; Motorola Ap-
pjication Note AN-747-
5 Nash, Garth. Low-speed
Modem Fundameniafs/' Motor-
ola Application Note AN'731.
6 Lange, Ron. * Bui Id the S35
MoOem/ Ktiobiiud, November,
1977
7 StarH. PeieL "Solid biate
Teltsphones Ring Relay/* 73
Mdgaztne Apiii, 1974.
8 Whippife Spenser basrc
Telepnone Systems. /3 Maga
zirw. Apr! I' June. 1975
Chae-up of modem numbet two tvery thing was by/7f on one lulu it boafd. This, does not
have the auto answer teaiure.
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Signature
Peterborough nh 03458
Exp, date.
Name
Address.
City
.State.
.Zip Code.
S12B
109
m
Kim W Lantz VEIAKL
Laniz Eiectronk's Ltd,
15 Ciifford Street
North Sydney, N.S.
Canada &2A 1X2
RTTY with the KIM
one more step
Lower €t«4
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Modified character set
Without 3 doubt, the
KIM-1 microcom-
puter has to be one of the
slickest little rigs on the
computer market. It is be-
ing put to work on alt types
of ham-oriented applica-
tions. It is decoding Morse
and RTTY and transmitting
Morse and RTTY, and all of
this with only the IK of
memory that comes with
the unit. (8080, eat your
heart out) At the time I
was first seeing all of these
articles (in 73 Magazine^ of
course), I did not have a
computer and was having a
terrible time deciding on
just what I should get.
After seeing Wilfred
Gregson's article (Sep-
tember, 1977) on "Receiv-
ing RTTY with the KIM"
and several others, I de-
cided on buying my name-
sake.
When I first tried
Wilfred's program, I was
amazed at what I was see-
la
ing. Even with the
7-segment display, the
words were very easy to
distinguish. I was quite
heavily involved in RTTY at
the time, so I had a ter-
minal unit. I found the
KIM-1 much more tolerant
of the various things that
affect RTTY. Such things as
distortion of the character
pulses that would drive the
old Model 19 crazy did not
seem to bother KIM very
much I was also using a
HAL DS 3000 version 2 in
my RTTY operations. For
anyone familiar with this
unit they will know that
besides featuring the
Baudot code, it is an ideal
computer terminal in the
ASCII position It was only
logical that 1 should want
the KIM to deliver the
RTTY to the HAL terminal
so I would not have to
struggle with the 7-seg'
ment display. This is the
basis of this article. It may
170
ermaiio
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1^ Header Service^ see p^ge 323.
171
M
seem rather ironic to
receive ASCII on a video
terminal that already can
receive m Baudot, but this
is aimed at the computer
hobbyist who would like to
print RTTY on his Model 33
or on his ASCII terminal
and does not have normal
Baudot provisions.
I guess you could call
this a glorified ASCIIto-
Baudot converter, but to
say that would be an in-
justice. Not only will you
get the full upper and
lower case, but you will
also get something called
"unshift on space" What
this means is that if you are
in upper case Baudot and
you receive a space code,
the unit will automatically
shift back to tower case
This might not seem like
much, but in the presence
Program listing.
O^DG A9 7F
D202 60 A\ n
0205 AO Ofi
0207 A2 09
0209 A9 00
03aB fl^ E4
0200 2C 00 17
02 1 0 30 03
0217 ac 00 02
0215 A9 or
0217 eo 07 17
02 M m 00
one S5 £7
02) E
A9
ID
0220
&^
E5
0222
2C
07
\1
0225
30
03
0227
4C
22
02
077A
A 9
14
022C
8D
n7
n
072F
2C
ot
17
0232
50
D3
02 M
4C
2f
02
0237
20
00
17
02 3 A
ro
06
02 IC
A5
E7
02 31
09
Ef
0240
e*
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0242
46
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§24 4
^^
E5
0746
C9
00
024i
FO
03
024*
4C
2h
02
0240
*5
r?
02«r
nR
ri
0751
AS
0252
8!5
E3
02S4
B9
QO
03
0257 fl9 £7
0259 4C 4 0 03
0?5t: 24 FT
025£ Id 03
0260 4C 6) 02
0Z63 06 E7
[^ 172
LDA I mm 7F
STA abs 174 1
LDY I mm Of
LOX fnm 09
LDA riiim 00 Put I trs Trr tfte Vtrs/ffgs b^ti
5TA,2 00E4
BIT (700 look for g start bit
BPL briBch »* ^©tecf start
IMP 020t) tot?li afTBln.
LOA inm OF set rn« first time tfeloy
5TA B^s I70T
LDA Imh 00 clf^ar ciev cli^ri, register
Slfstt fr0£7
LDA Iwp 10 s«t tilt pdsTtTort register
STA.jT OOE^
BIT 1707 Is first 4>lay tUTstvwd 7
0Mt branch 1* vsi^
J**P If not back to 02Z2 and waif
LDA fniffi 14 5«t timer ^or second delay
.STA nb% 1707
Bit 1707 Ik timer f [r^rshed?
BMP branch If yes
JMP It not, go to 022F arrd wait
B»T *i?«(i the st«t© of rnput i7O0
BMI tr it U " 0 " .do not toad
LDAp? load th# bU 6+ 00E7
0aA,2 00E5
STA.z OOEt
LSR,z 00E5 snIH b^t position reofster
LDA«2 OOEI^ Ch«€li fc^^ sH 5^ hauH^t ^har,
CMP fRN 00
BEO ail f (nlsned 7
JMP to 022A
LDA^i 0017 Mtteri / figyres prefix
ncji ^ - rtr»E4
TAf indsK for 1opkui>
STA,z 0OE3
LDA ahsfijy
STA>i ODE?
JrtP to output to tarmtnaf routTne
0IT,z 00E7 ch<5ck for a comprspirid
BPL to fitncttan
JMP t<> tlnlsh
kBL,g 00€T Decod* le^tte^rs f unction
of severe noise and fading,
this is a blessing in
disguise Here you will
have the RTTY printer that
manv dream about. If you
take the trouble to get this
going, you will be in for
some very artful RTTY pic*
tures.
After studying the pro-
gram, the first thing that )
had to do was to get the
OUTCH subroutine in
there somewhere, With this
come the necessary
changes to the lookup
table so that the characters
that are OUTCHed will be
the corresponding ASCII
characters One of the first
problems that was en-
countered was inter-
ference with the command
detection For example, if I
put the ASCII code for
space, 20h, in location
026S ItA £7
0267 10 ^7
0269 A3 00
026B fl5 E4
026 D AC ai 02
0270 50 07
0272 A9 20
0274 i5 E4
0276 4C nt 02
0279 A9 01
027B m 01 IT
02 7 £ SO 00 17
026 1 m 1 ?
0263 BD 07 !7
02B6 2t QJ 17
0299 30 03
O?a0 4C 86 02
028E A9 00
02^0 8D OO 17
OJiJ^ 4C OD 02
0296 EA
0340 85 EO
034? S6 Ef
0B44 B5 €7
054(1 eg BO
034$ FO ta
054* C9 OQ
034C FO \9
0?4E rts 20
0350 FO I C
05^2 C9 40
03^4 FO lA
0>^6 20 AB IE
0559 A5 EO
&55B A6 £1
0550 A4 E2
dl^F 4C 5C 03
0362 A9 OD
Q3^A B5 E-*
0566 A9 20
05Sa 4C 56 03
036fi Ag 07
D?6D flC 56 03
0570 A9 00
0572 4C 56 05
BIT./ 0OE7
BFL branch to 'flgur&s ^ricodft
LDA Imm 00
STy\,? 00E4 latter* cammand
JMP to f I n I sh
BVC tell
LDA litiBi 20
STA*? 00E4
JMP to the tif^ish
LDA {rm or BELL
STA abs »701
STA ttti& 1700
LDA IHK 15 I'lltlSH set for the third €«lav
St A Inn 1707
BIT 1707 look
BMt bach
jMfi
LOA liftfn 00
STA I? 00
iMP
NOP
<:T/v.r OOEO save " A "
STXpi OOEI sav^ «* X "
STY^f 001? savt « ¥ -^
CWP Imnri 60 r* this a 5p.%r(> cotJ# ?
BEO It so. Then go to 0>62
CWP rin« 00 1^ thTs a beM cod« 7
BEO If se« th^n «d ts 0 567
CiiP t«m 7^ 1^ ^i^fi ^ " FIG1 " cod*
SEO If so, thsfi fo to 036C
CUP liiiR 40 Is Tlvis a '^ LTRS " io^e 7
iEO It *Q» theri go to 056C
JSR OUTCM s*nd cljaracter T© rprnJnal
lOA.r OOEO Restore *****
LOX,i OOEI Restore " X **
inV^E pOE2 Restore " V »♦
JMP back to malri prograin
LOA I mm Do unshtft on space roi^tlnu
5TA,z QOF^
LDA Imm 20 space rou-tlno
JMP to OUTCH Ht 0355
LOA Tmut 07 t>el,( routine
JMP to OUTCH *t 0365
LDA Iftw 00 HULL routine
JMP to OUTCW Bt 0356
031 B, the command detec-
trnn p^rt of the prngram
would sense this as a FIGS
command and all the
characters received a^^ter
that would be upper case.
Therefore, for all the
commands, spare, and hell
codes in the table, there is
another part in the output
routine that will look for
these and insert the correct
ASCII corle^ for the func-
tion. After these modified
codes are s*»nt to the ter-
minal, they are changed
back to their original value
so the command detprtjon
will function prooerly Spe
locations 0340|^ through
0374h for this function.
The values for FIGS and
LTRS that are oi rtput to the
terminal are simptv nulls
because we do not want
the terminal to print
anything on the^f* com-
mands If these wf^.re not
changed to nulls the ter-
minal would space, 20h on
a FIGS command, or out-
put the character @ . which
is 40h on a LTRS com
mand.
The next ?tep in the
modification was the dele-
tion of all unnecessary
steps in the program, such
as the display and all the
software that <;upDorts that
funri-ion This also includ-
ed the '^MOVF ' and
"SETX^ parts in the original
program. Vou will see that I
also eliminated the tuning
part from the original
because ! have a terminal
untt with complete t'lning
facilities If you were to
use the PLL on the KIM for
your terminal unit vou
would have to add this on
at the beginning So do not
forget to change the
neressarv commands for
rnout from ^hp PL I circuit
and pin 8 on the applica-
tion* ^onnpf^for
I used H high-*ipeed *^ot-
ter and Brumfield reed
relay to control data nn om
8, but I would suggest the
photo-coupler as the best
method If you are not a
RTTY advocate and do not
have a terminal unit, ^he^e
are several units on the
market now which, for
their price, cannot be
beaten. Many of these do
not come with the high
voltage loop supply which
the mechanical units such
as the Model 19 require
but this is |ust fine. We do
not require the high pull-up
voltage that the^e old
beasts required Rf^ mem-
ber we are modern! All you
neerf 15 thp current to Hght
the LED on the coupler.
Thi^ eliminate*; one major
expense of a tprmina! unit
If you are serious about
this at all you really
should invest in one of
these cheap terminal units
You will receive some fan-
tastic art and see some of
the mn*;t «*niova*^le QSOs
that you could ever wan*
to see You can then really
enjoy the mode and nnt be
plagued with the errors
cau«;f*d by QRM and QRN
I hope that this article
wjII lust be the start of a
whole RTTY aoerating
system for the K iM 1
owner, featuring all the lux-
uries of ^his "receive" arti-
cle and also iome -.^ery
desirable transm'^" ftinc-^
tions tike Urge memory
buffer for typmg faster
than the output rate cor-
rection Bnd editine of
transmitted data before it
is actually transmitted, and
more important, very little
extra hardware.
Also, if you are thinking
of a computer, I hope I
have added lust one more
plug for the K fM1 You will
be able to copy all RTTY at
all standard speeds, lust by
changing the bi^- m the
timer ( would also tike to
talk to people ^^r qre
KIM 1 owners I ysuaily
hang out ?Hnut 14 090 on
Sunday at '140(17 So please
give me a holler anri n-paybe
we can trade information
on ^hl*; and other prugrams.
f^)h ves, anybody have a
floppy on a K1M?B
HOBBY-WflAP
Model BW 630
WIRF WRAPPING TOOL
For AWG 30. .025" fO 63mm) sq. post,
"MODIFIED" wrap, positive indexing,
ant'-overwrapping device
wrapping
-^
^Ob
OK MACHINE & TOOL CORPORATION
3455Connpf St Hmnx N Y '047^ (212} 99^ 6600 Telex 12S091
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COMPLETE WITH BIT
AND SLEEVE
^
§^ R««(*9« S^ivit^e—s&tf pao^ i23
^y^ }
a
Jan A. Hei^ WA4VQD
1519 Pine Rid^e Cl
Montgomery At 36109
Ed Mehnert NJNN
PO Box 73
Scott AFB IL 62ns
DX Delight
-a do-it-all program
Editor's Note; WA4VQD wilt provide a full listing of data for US and world cities and alt DX countries to all tliose who request such and
enclose a tegal^size SASE.
Calculating Great Circle
distances and antenna
bearings to various points
around the world by hand,
even with a calculator, is
tedious and time-con-
suming. Here is a program
that does it for you. By
entering a set of coor*
dinates, you can get the
GREAT CIRCLE SEARINGS AN]^ 0ISTAHCES PRQGI^AH
no TOU MEEB tMSTftUCTIONST - YES OR HQ
? YES
THIS PfiOGRAM CALCULATES GREAI CIRCLE DTSIA^CES IN
SIAIUTE HUES A«D KjLOrtETERS AHB lEAftlKfiS BETU6EH
tm AND THE ItEST OF THE yORLD, LflllTUDES IN THE
MBRTHERN H%n ARE POSITIVE ANt SOUTHERN HEN ARE NEC.
LQNfilTUBES IN THE EASTERN HEM ARE POSITIVE
MB VESTERN NEH AKE NESATtUE. ALUATS USE DEGREES
UllH DEC! HAL PARTS - NO HINUTES AND SECONDS.
UHAT IS YOOR NAHE ANB CALL LETTERS
? JAN HEISE - UA4yOD
UlfAT IS YOUR LOCATION (HQFIE QTHJ?
7 MONTGONERV, AL
UHAT IS THE LATITUDE OF THIS LOCATION?
T 32.3
UHAT IS THE LQNeilUDE OF THIS LOCATIONf
t -64.3
SELECT THE FUNCTION TOU If ANT AfID ENTER THE NUHBER
1 ^
2 =
J =
4 =
^ =
6 =
7 =
? 5
GIDIAL ORID CENTERED ON YOOR LOCATIOH
UAT EVEir IS DEGREES I LOUS EVERY iO DEGREES
HEARINGS AITD DISIANCES TO MAJOR US CIIIES
BEARINGS 1 DISTANCE TO n LOCATIONS F^OH THE
ARRL COUNTRIES LIST - LISTED BY CALL PREFIX
IDTH US CITIES AND PX LIST.
BEARINGS & DISTANCE TO USER SELECTED POINTS.
ENTER Hl\t CENTRAL LOCATION
TERMINATE THE PRGDRAfll I f
ENTER DISTANT LOCATION DESlSNATIfN
? PARISf FRA4fCE
EKTER LATiTtJBE OF DISTANT POINT.
f 48,fe3
LNTER LONGITUDE OF DISTANT POINT,
? 2.33
niSTANCE FROH HOHTGONERY, AL TO PARIS, FRANCE IS 4522 MILES
THAT DISTANCE IS 7277 KILONETERS*
BEARING TO PARIS, FRANCE IS 4A DEGREES.
m TOt! LTANT OTHER POINTS CALCULATEB^ YES OR NO
V NO
Fig. 1 Sample run of program instructions.
distance and bearing to
any other point in the
world. Using the data com-
piled and supplied here
with the program will yteld
distance and bearing
tables to major US cities
and all the DX countries on
the American Radio Relay
League [ARRL) countries
list.
Haw It Started and Credits
Due
When I started selling
selected pieces of amateur
radio gear to pay for my
growing computer system,
my ham radio colleagues
always came up with the
old familiar ''What will it
do?" or "Td build one of
those computers if I could
find a use for it/' I had a
canned five-minute disser-
tation on the virtues and
potential applications for
my system which I could
immediately recite, This
usually quieted them, but I
wanted a good amateur
radio application to prove
that my computer could
"really do something/'
I got the idea for this
program from Ed Mehnert
N3NN while he was giving
a talk on DXing to our local
Twin Base Amateur Radio
Club. Ed mentioned that he
had developed a computer
program written in BASIC
on a time-sharing system
which allowed him to
calculate the distance and
bearing to the DX coun-
tries At that moment, the
light bulb in my head came
on, "If it will work on a
time-sharing BASIC sys-
tem, it wilt work on my
IMSAir I said to myself.
Then I knew 1 had found a
good ham radio program
for my computer With
Ed's blessing, I rewrote his
program and used the ex-
tensive data he compiled
on the DX locations to
come up with this program.
The General Theory and
Calculations
Any edition of The ARRL
Antenna Book features a
section on finding direc-
tions. This includes a
description of the calcula-
tions for Great Circle
distances and bearings be-
tween any two points in the
world. These are based on
two formulas using trig-
onometric functions.
For distance: Cos D ~
sin A sin B + cos A cos B
cos L.
For bearing: Sin R ~ cos
B CSC D sin L >
A = your latitude in
degrees
B = the latitude of the
distant location in degrees
(latitudes in the Northern
Hemisphere are positive
and those in the Southern
Hemisphere are negative),
L — longitude dif-
ference between the two
•The American Radio Relay
League, The ARRL Antenna
Book, Twelftti Ed., Newlngton,
Conr^ecticut. 1970, p. 284.
3 T74
cniES LISTING CENTERED QN nPNTGOrtERY, AL FDR J Alt HEISE - UA^UOn
HCARIMOS AHA DISTAItCES TO ttAJOf^ US CITIES
HEARINGS TO
nlL - IIEAMS
D% LDCATIONS ON Afif^L COUNTRIES LIST
A CQUMTRy DELETED FROrt ARRL LIST
m LISTING CElflEI^EB FRDN nCTNT&OflERTp AL FDR JAH HEIS£ -1144^00
CITY
HILES K/N BEARING
ANCHORAGE
3423
5509
325
ATLANTA
149
240
47
KANeOR-ME
t276
2053
42
EIRNIHGNAH
dt
142
341
BDISE-ID
17f3
2885
304
BOSTON
1009
1753
46
rHAftLOTTE
374
602
S6
r:HEfENN£
1191
1917
306
CfNClNNATI
4fl1
774
12
CLEVELAND
d84
HOI
20
rOLUhHA-SC
328
528
60
HALLAS
6M
985
376
DENVER
1U0
1867
301
[tES-HOINES
750
1220
330
DETROIT
714
1149
14
GREAT-FALLS
1678
2?00
316
HONOLULU
4403
7086
200
HOUSTON
577
9?9
255
INEIANAPOLIS
510
034
1
JACKSONVILLE
310
499
115
KANSAS-CITT
661
1064
318
trio XVI LLE
200
463
27
I AS -VC GAS
1660
2671
207
IITTIE-ROCK
303
6U
297
1 DS~ANGELES
1042
2964
282
lOUISVILLE
409
658
5
HEH^KIS
288
463
313
HiANf
569
916
141
niLllAUKEE
74S
1199
353
HiNN-ST.RAUt
950
1529
339
niNOT
1348
2169
329
NA5f<UILLF
2*4
425
354
HEyiN6?0N-ARRL
990
1593
45
NEU-ORLEANS
370
435
233
KEU'TORK
895
1440
46
NORFOLK
654
1052
57
lIlLAHONA-CITr
479
1093
291
DifANA
820
1320
322
F'ETFI*I0R0yGH-73
1069
1720
43
PHUAIELPHIA
815
1312
46
F-NOENIX
T49t
2399
279
flTTSBURIi
6A0
1062
30
rORTLANB
21 3A
3437
306
RAPID-CITV
12(9
1962
316
ST. LOUIS
496
790
334
!?ALT-LAKE-ClTy
1535
2470
300
SAN-FRANCISCO
2D 64
3322
291
SEATTLE
3158
3473
310
tan;>a
374
602
142
UASHINGTON-BC
693
1115
46
UICHITA
7594
12221
357
Fig. 2. Sample run of US cities list
locations. In this program,
L = LI - L2, where LI is
your longitude and L2 is
the distant location-
Longitudes in the Eastern
Hemisphere are positive
and those in the Western
Hemisphere are negative.
D = distance in nautical
miles or minutes of an arc.
One Great Circle arc is 60
nautical miles and 1 min.
= 1 nautical mile =
1.15078 statute miles. In
this program, the output is
converted to both statute
miles and kilometers.
R = the direction of the
distant location from vou
in degrees east or west of
north or south.
What this means is that
the result will be between
-90 and +90 degrees. This
must then be converted to
0-359 degrees. For exam-
ple, a raw bearing of 17
could mean 0 + 17, 180 -
17, 180 + 17 or 360 - 17.
Thank goodness for the
computer to keep track of
all the signs.
Most BASIC interpreters
do not have arcsin and arc-
cos functions; therefore,
the arctangent function is
used to get cos C and sin R
in the formulas back into
degrees based on the fol-
lowing relationship:
DX PREFIX
NILES
K/M IE
ARtNG
1
A2C
8338
13418
lOf
7
A 35
6811
10972
252
3
A4X
7727
12435
38
4
A6X
8156
13125
37
5
A7X
7580
13198
41
4
A9X
7451
11991
40
7
AC 3
8320
13402
S
fl
AC4
8164
13138
2
9
AP
7902
12717
24
10
lU
8074
12993
332
11
81-N
7241
11653
343
12
BT-CTR
7671
12345
351
13
lY-S
8430
13566
337
14
C21
7151
1 1 500
278
15
C3I
4691
7549
53
16
CSA
4511
7260
90
17
C6A
610
995
124
10
C9rt
8743
14070
92
19
CE
4620
7448
166
20
CE9-ANTR
B45D
13599
100
21
CEOA
4372
7036
203
22
CEOX
4049
6516
173
23
CE07
4599
7401
174
24
CH
694
1117
!57
25
CH
4430
7142
66
26
CP
3539
5695
158
27
CR3
5552
0935
111
n
CR4-IIOy-D4
4064
6540
91
29
CR5
5503
8985
96
10
CR6'N0U-D2
7424
11947
95
31
Cft7/C9Pt
8743
14070
92
32
CRS'DEL
9869
15882
302
33
CR9
8409
13533
337
34
CR10-DEL
9869
15882
302
35
CI
4231
6809
61
36
CT2
3332
5362
i?
37
CT3
3890
6273
69
38
CX
5004
0053
155
39
D2ft
7424
1 1 947
95
40
D4
4064
6540
91
41
1^628
0903
14328
77
42
OL-DEL
4709
7570
43
43
DA-UE5T
4709
7570
41
44
Bh-EAST
4026
7766
39
45
HU
0703
14006
327
46
£A
4445
7153
57
47
EA6
4012
7744
55
40
EAO
4078
6563
74
49
EA9-CEUTA
4410
7097
62
50
EA9/R-DEL
4332
6971
76
51
Efl9/S-DEL
4332
6971
76
52
EAO-&£t
6549
10S39
86
53
EI
4048
65H
44
54
IL
5169
8318
92
55
EP
6969
11215
34
Fig. J. Sample run of DX countries lisL
3000
OATA
ANDH0RA6Ep61t-
3005
DATA
BAHG0R-NEf44.0
3010
DATA
80lSE-IDp43.6»
3015
DATA
CHARLOTTE, 35. 2
3020
OAFA
CINCINNATI, 39,
3025
DATA
C0LUNBIA-SC,34
3030
DATA
II£NVER,39.7,-r
3035
DATA
DETROIT, 42.3,-
3040
DATA
HONOLULII *»• '
3045
IIAT4
■r-1
3050
..**,K5p45,6U0
DATA
44.5,?0-S0CJ2
4495
DATA
7X, 36, 3, 8^6, 12
4500
DATA
BZ,29,47,9A1,4
4505
DATA
9Kt29,40j9L1,B
^510
DATA
9H"UEST,3J01p
4515
UATA
9V1-S]N0Jt104
4999
DATA
ENEAtA2,2,2
9999
END
150t*TLANTA,33-75,-84,4
p-60.8|FIRnrNGHAnp33.5,-06.0
-II 6. 2, IflSTQ**, 42 -4, -71
,'80*a,CHEyE#IHE,4l.2,'10J '^
I, -04. 5, CLEVELAND.*' '
,-81, DALLAS, 37 .,fV, T0,3,-67
O^*'*^* jp44,4X4,32,J5
0^ .,,--f,39.5p5H3,-0,35
rf,5T5J8p-16,5U7pl3,2
3 p-1 7 T,5X5,, 5,32,514, -1,37
, 1 5 , - 1 7 r *^ 5 p 1 a , -77 p 70-AI)£N , 1 2 , 5
p 54 p?Pep -29, 5,28,707,-15,5, 36
,5,-59,5|9Qp4,73,BRU7,-59
4pl2p96p5.5,0p9Hp36p14,?J,-16p28
p-13.5,9H-EflST,1.5pM0,5
5,9Hp27,85,90p-5pl5,<3U,-3,29.5
,9Xp-2.5,3O|9Y4-TR&T0B,lO.5p-6l
Fig. 4. Portion of data statements from main program.
175 Jdl
X = aictan
aretan
or ar*^tar
sir. ^
::on X
V 1 os^X
cos X
nmt
\n
sin
?>
PadiRn^ are ns**H in per-
forming the rakulation*:
rather than degrees. The
foMowmg fcmiila'? are
used to convert degrees to
radian'; ^nd vke ver^a:
Opqre*?!? x r.
Deqrf*es t=
180
The degree^ n^ii<f be
entered in decimal form
for thi«; oroer^m and not in
miniftes and -^e^^onds
The Program De^rriphon
"^he program was built in
a fiiodt ;^r mariner with a
'^rrenu type selertron" of
che funciiofi desired Each
ftm< tiop y?*^< this fame
calculation*; which are all
in one subroutine This
make? the program easy to
modify By taking out the
appropriate block of call
and print in^Jtrijrtioos and
data, you can eliminate un-
wanted functions I used
straiehtforward BASIC
commands and avoided
any known unique char-
acte«^istics of my system
Numerous remark state-
rneot^ were L^sed to help
clarify the program.
The instructions from
the h'^ginning up to 400
give you the optton to get
in^^^turtinn*; th^p mput the
datp» for youf location, ^ind
finally select which func
tion you desire As you can
see from Fig 1 the follow-
ing functions are available
from the menu
1, This option prints a
global grid centered on
your location. This allows
you to make your own
world map centered on
your location. These
azimuthal maps can be
purchased centered on a
few of the major cities
such as Chicago or New
York, but this function pro-
vides the data necessary to
make one for any central
location
2. This option prints the
distances and bearings to
over fifty sele-^ted US cities
using the data provided in
the program You can add
more if you wish.
3. This notion prints the
distances and bearings to
all the DX countries on the
ARRL countries list These
are listed alphabetically by
radio call area prefix
4. This option gives the
cities list, automatically
followed by the DX list.
5. This option allows you
to enter any distant loca-
tions at the terminal and
get the distance and bear-
ing in return,
6. This option restarts
the program at the point
where you input the cen-
Main program listing.
5?
^^ I NT
PRORRAWHEO B^ IfiW ■ WEIS€, Ufl'tipp . nm 77.
5a
1*
vow ifCP U*!JI RUCTIONS'
fE5 0*» MO"
AS
7# IF TI^'HO" THEW U?
l^fi o(?t«^ ^IH'*: Pl»*)nt4t* r^.CUUTf^ 0»|:flT riftCLE 1>!STAIIC£S IH"
130 f^^m lOiJ <llfi» T«F IIFS' JF THf UflR'fl, IflTflUMS IW tW
;30 n^m '^*lO»THlP*f HfW m ^•ISTTtMF fk**^ coyiHrifM HEfi *RE «EG
140 PRIM^ "LOrtenilftES !» ^IfE E*?TE!ri* *|EH 4ftF POSlllVE*'
150 PKim ^#^11 yfSTEM* «Ef* ARl HFI^^fK^F. AlWAYS USE BlGftFtS"
140 ^'frTHT
■yT^H
1 HECtWAt P^liTS - NO N'NHTt*! Ml< SECONDS."
1*5 PftlMT
Tc mm
^'MHAi
I? fOliP NftWF ^''fTI r.^u I.F^^FO'-
1?5 TNPJIT
LTWF
Nl
IBn pfriNT
"UHAt
16 YOUR LOCi^TtON (HONE QTHP"
195 iMCtJT
LI#E
Uf
\9(^ ■'I^TN^
'UHfll
IS TMF LrtflTUOJE W THIS L0C<^T!O^^"
^95 irtPIIT
It
>00 «tFN -
rOK'iFft^ A 10 ft^OfAWS
?*5 LEI ftl
=4*3,
H15?/I8t»
'10 P'^TUT
?20 PS!f|T
"UHAI
\ TS THf LONEinroF OF THIS L0C#^TON^"
*Mn !J|PIJI
LI
'5C LET J-
=0
?5: tET F=
0
3S5 GOSMl
3000
7*0 PRltfl
'SFLEtt tHi (^IINIIIOM VQU U^Ht Am f«T£ft tH£ HUrtUCfr-
''*5 «*S:T«1
770 »&TNT
^! =
OlOftfli &l>!li rFNIEREtl ON TOllfi Lnr^ATlOft"
:*7? ppfii?
ir
(I AT fVE** '^ Dff^^fFS % LONC^ FWFR'T 30 Uf^GRFES"
/PO PFIN^
9f4P|H0¥ ^Hfl Til*itAf*rF*! TO mm US CITIES"
?(r5 PP^HT
"1 ^
iFflPli^GS H HL?7A«f:F TO UK i.finftTTnNs frdm ihe"
^flfl PRlrtT
II
<^RR|. C00M1R1ES LIST tlRTFTl l?t CALL PRCl'Ilf"
">:! I'PINT
"4 -
t(['TK UP Li HE? ftwn TiX nsT
''?^ j^RittT
"5 --
B£*^RiN6S i DT^*T4*iC€ TO U^FP Si-XECTEO PClNfS. "
-*o<> PHim
"*
^NTIF. Vfy LEpfTRAl idCATTOW
M5 pi?TW*
"EftftKt' '^ -"T ^ROGRAH
.^^7 ff**fti
M^ IHfUT
S
.417 •'I'TPIT
.^15 J*»r e ^?^^r ^
fO«,^l5.605.5K,;00,50.****
10P SOSIII*
jnoo
4«i PPTNT
^S«EA! CIRCLE rgoiinTi^lCs Lfi'TCRII' OW "jUf
T*t f(^!#7
v^ mm
"tf^OOftAmili? FOR ;f»l
#3(* 1>PT»»T
4?F 9R}ni
-14T|TynF .OWC^IYiiOF IIILFg HIIIWETERS BFAPIHI?'*
M'/ ^'tlMT
"
IV - - **
^4(< FOt l2 -'IftO TO itn^ *i Ef 4fi
4S0 roft F^
.-*o
rp *o Sif f
-uo snsiiF
^mti
1*5 PRINT TAB3j3;Tflfin;l,3fTAR32j0UTA»3O;D2;lAB44:IR2
^A8 ffErt - CHECK TNE LINE COUNTER,
4*? LEI It^Kfl
470 IF K=55 THEN 405
475 NFJfT I
480 NFJfT L2
49? *iOTQ 230
485 fJOSUP 1000
4f0 PRINT "LrtTlTijiiF LONOITUOE HILES KILOHETEfiS SEARING"
4«i PRINT -— ^— -— -^- ^^ «
495 SOTO 475
r-OO REN - 500 JIMNBFREI) 5T4TFNENTR READ the Flt^iT SF? OF MJA
50? frEH UHICH CONTAINS THE US CHIES MTA ANfl PRINTS LIST,
JiOO REN - F I? ft FLAG TO SEE IF 80TH CITIES i n IIST ARE
h<i9 REM DESIRFF. IF YES ENTER AT 510 t F = U
rjlO lET F=t
JjM RFN - "5^!^ IS ENTRY pnTNT FOR CITIES ONLY iF^O PRESETS
*J?0 PRINT '^CTTIFS LISTING CFNTEREfl ON ";yi;" FOR ";Mf
S25 PRINT
f.30 *^RINT "BF^RIN6S ftNEl HfSTANCES TO HAJOfl US CIIIES"
^35 PRINT
■^iO PRINT fAR5rCllY-;TA»l5faAT/lON6 NlLES K/N tEAfilNG*
■>45 PRINT' — ^ — — *•
b50 lET K-K+1
559 «E« - RF«i* f^ATA t CHECK FOR END QF ¥UE.
560 READ HIjl^L?
r.&5 IF N•'''EN^ATAt" THEN 5f7
li49 REN - 60 »*FRFOR« THE CALCULATiawS
W^ 00S<|| 1000
U?% PRINT N*ff4»i3;BrV"|L?fTAB38;0i;TAilS;D?;TflR41;R2
bU IF K = 55 THEN 5?0
^85 60TO 5S0
b?0 GDSIKf 2O00
1^95 GOTO 54a
%9^ RFH - IS FUn SET FOfr BOTH CITIES AND BX LIST?
.97 CF FH THEN *1*
S9D RKSTORf
^9» 60TD 250
MO REN - dOO NUMBERED STATEMENTS REA& THE StCONfi SET OF
602 REN lAT^ UNICH IS iHf D)f COUNTRIES LIST nAT4.
6^1 REN 605 TO 410 FfN9 rHE END OF TKF FIRST I^ATA.
^95 READ n4«ii^L2
MR IF HI - 'rNPAT#l" THEN 614
M* msm 2000
AI5 PRINT UtARTHGS TO DX LOCATIONS Oi* ARRL COUNTRIES LIST**
if-^f* PRllff gFi - NFANE A COIINTRt DElFTFD FRON ^RRL LIST"
625 PRTWT
^30 PRINT nx ilSTiNG CENTERED FROrt "jW*r FOR ";«•
<^35 PRINT
640 PPINTTAR5;'DX Pf^EFlX LAT/L0Nr> NILES K/H BFAfitNG"
645 PR1 NT '^ **•-*- — * — ■ -,-«,, ^-— -— ™. ' ^-^
M
IB
tral location data. This is
useful when you are pre-
paring several lists for dif-
ferent locations — for all
your ham friends.
7\ This option simply ter-
mi nates the program.
The 400-series state-
ments all correspond to op-
tion one, which is to print
the global grid Nested
loops are used to perform
the calculations with the
latitude incremented by 1 5
degrees at a time from -90
to +90, while the
longitude is varied from
-180 to +180 in in-
crements of 30 degrees.
The ^OO-series state-
ments are used to perform
option two, which is to
print the US cities list (see
Fig. 2) A flag (F) is used to
determine if lists of both
cities and countries are
desired. The 3000-series
data statements contain
the cities data used with
this option. The program
looks for ''ENDATA1" in
the city field to tell it there
are no more cities. The
data is then restored for
use again, and the program
either goes back to the
menu or on to prepare a DX
country list.
The 600-series state*
ments correspond to op-
tion three, which is to
prepare the DX countries
list (see Fig. 3), If the entry
here is from the menu, the
program first reads the
data and looks for "EN-
DAT A1" in the country
field. This means it must
read through all the cities
data, but since no calcula-
tions are performed, vir-
tually no time is lost. The
data for the DX countries
list is contained in the
4000-5eries data statements
(see Fig. 4). When this data is
reached, the program oper*
ates just as it did for the
cities. It looks for an "EN-
DATA2" in the country
field to indicate it has
reached the end of the
countries data. The pro-
gram then returns to the
menu.
The 700-series state*
ments compose the routine
used to calculate indi-
vidually-entered distant
points. This routine is set
up in a loop, which allows
you to continue to cal-
culate individual points un-
til you desire to return to
the menu.
The 1000-series subrou-
tine performs all the
calculations. The subrou-
tine can be used as a stand-
atone program if desired. It
requires that A, B, LI, and
L2, which I have previously
discussed, be provided It
returns the following
results: D1 = the distance
in miles; D2 = the distance
in kilometers; R2 — the
bearing in degrees. All of
these are rounded to the
nearest integer.
In the routine, L is
calculated and then
hi^ READ HI,I,L2
^iS IF ilf="FN»i^Tfl2- THEH 696
^.70 m%m tODO
^.eO IF K-^^ THEN kn
a^ soro 650
4^fO liOSUK 2090
ff5 £DtO 640
^f6 RESTOI^E
7«0 fiErt - THE ?00 l*U«6£REi^ Sl^^lErtlMfS rlAKE IIP THE RQUTIWE TO
/01 REM - CALCULATE USER EMTEftED CDOrilMArtS OWE AT A TIrtE,
:^05 f^ftlNT "ErtTER J^ISTANT LOCATION DISI&I^A I lOff"
/1 5 INPUT LI HE flit
720 PRIWT
725 PftlWT "ENTER LATITUDE OF OlSTANT POmT."
/3S INPUT B
/to PRINT
^45 PfilWT '^ENTER LONGITUDE OF IrlSTiINT POIrtT/'
755 INPUT L2
7^0 GOSUS lOOO
745 PRINT
770 PRINT ■'DISTArtCE FRDH ";y*;" ro ";ini;" IS ";Oir rtlLES*"
7?l PRIWTMHAT DISTANCE IS "jD?;* KlLOHHeRS,"
771 PftldT "lEAftlNS TO ";«!*;" !S ";R3; " OEQftEES,"
775 PftJlIT
7B0 PRlHTmO %m UANT OTHER P0II4TS CALCULATED? YES OR HO"
715 P«INT
790 tMPUT It
?f5 IF Tl ^ -ITES- THEN 705
7f? 60 TO 250
IfiOO REH - 1000 SERIES SUBROUTINE PERFORfiS ALL CALCULATIONS.
100T LET LSL2-LI
ie02 REfl - X 15 A Ft AC FOR TESTliS L
1003 LEI X=0
1005 RFI4 - BRING L UtTKiN RANGE -180 TO
1010 IF L<-ieO &0 10 1025
10IS IF L>180 GO TO 1035
1020 GOTO 1040
m% LET l = L + J*0
103D GOTO MOO
LET L=L-3A0
IF L<0 THEN I !0u
LET t^\
IdO
1935
1040
(045
tlOO
mo
1115
1119
1120
REN
LET
LET
REN
LIT
H25 LET
1130 LET
1134 REN
CONCERT L km B TO RADIANS
B1 = 6*3.14159/180
I = t*3J4t59/190
- COMPUTE THE DISTANCE ANGLE
P>tCIS<LHCOS(An*CGS!Bi I *SIN( AM »5TN(Bn
PUATN(SOR( l-P*P>/P)
P2=P1*l80/3-t4f59
- OiSTANCE A*»6LE ffOST BE POSITIUE IF HOT ADD \m
1135 IF P2<0 GOTO 1145
1140
1145
1149
1150
1151
1154
irss
1160
1164
IU5
TUB
1169
1 1 70
1175
TI30
nS5
IffO
1200
1305
1210
1215
1220
\m
1235
1240
1245
1250
1255
1260
1500
1510
1520
1530
1540
1400
1605
1610
1 620
1630
1635
t640
1645
1700
7000
7001
7005
7006
70O7
7005
2009
?010
?01T
:*012
7020
7030
GOTO fl50
LET F2=P2+180
REfl - COWPUTE DISTANCE
LET 01 ^ INT(P2*oO*1 -15152*. 5>
LET li2^HiTfDl*t,6a91+,5»
RErt - COMPUTE THE BEARIitG ANGLE-
LET R=CDStin«5IN{Ll/SlN(PtJ
LET Rt=ATN4R/S0R(1-R*Ri)
REM - CONVERT BEARINGS TO DEGREES RQUHSEO TO flEAREST INT
LET R2 = jHT(CR1*tB0/3.l4159M.S)
RE« - DETERNINE WHAT OUAflRANl THE BEARING ANGLE IS li* AND
RErt - ADJUST THE DEGREES*
IF ABS<R}>.9?V998 THEN 1500
IF ABStf?)-:, 00174 THEN f600
LET B2=(B+.n i 3 J4I59/1B0
LET R3=C0S(L>»CCSiAnfC0Sie2^+SIN(F2J*SIN(A] )
LET R4=ATpf(SQRU-R3*R3y/R3J
LET FfA = C0StIi2)*SlNa^/SIWfR^i
IF X^l THEN 1240
IF flBS(ft6) V AP5(RJ THEN ?:30
LET R2=360-ABS(R2)
GOTO 1700
L£T R2 = iai}+ABS?R2)
GOTO 1700
IF AB5(R6I ABStRlIHElt 1255
LET R2= tB0-ABS(R2)
60T0 1700
LET R2 = A»Si«2*
GOTO 1700
If X=1 THEN fSiO
LET «2 = 270
GOTO 1700
LET R2=90
eOTO 1700
IF ABS(L) > 178 THEN U40
IF BsA THEN 1630
LET R2-0
GOTO 1700
LET ft2-1flO
GOTO 1700
IF 8>A THEN t630
GOTO 1610
RETURN
REN - THIS
REn '
PRINT
PRINT
PRINT
PRINT
PRINT
PRINT
PRINT
PR IN I
*£'0
RETURN
ROUTINE PRINTS BLANK LTNES AFTER EVERt 55
LINES OF DATA SO PAPER CAN BE CUT STANDARD SUEH.
177
:2
brought into the range of
-180 to +180 degrees. All
angles are then converted
into radians and plugged
into the formula to com-
pute the distance angle.
The bearing angle is then
computed.
The rest of the calcula-
tions ensure that the bear-
ing angle is placed in the
correct quadrant. For most
angles, the procedure is to
take a slightly incremented
point (0.1 degree) from the
original angle and com-
pare the sines of the
original and incremented
angles. The original angle
is placed in the correct
quadrant depending on
whether the sine increased
or decreased For any L
that is positive, the bearing
angle will be in quadrant I
or li, and for any negative
L, it will be in quadrant III
or tV Keeping this in mind,
you can see that the in*
cremental test will tell you
whether to add or subtract
the bearing angle from 0 or
180 degrees to give you the
final bearing angle.
Before the incremental
test is performed, angles
which are so small that the
test could put them into
the next quadrant are
sorted out and simply
rounded off. Since sin[0} =
0 and sin(90) = 1, the
folfowing procedure Is
used:
If the sine is positive and
very close to 1, then angle
= 90 degrees; if the sine is
negative and very close
to 1, then angle ~ 270
degrees; if the sine is
positive and very close to
0, then angle = 0 degrees;
if the sine is negative and
very close to 0, then angle
— 180 degrees.
Once the distances and
the bearing angle have
been calculated, the rou-
tine returns to the calling
segment where the results
are printed.
The 2000-serie5 subrou-
tine merely prints blank
lines and new page headers
to keep the output in a
page size format A
counter (K) is used in each
option, tt calls the new
page routine after every 55
lines of data are printed.
Sidelines and Miscel-
laneous Information
The complete program
with all the cities and DX
countries data requires
about 1 4K of user memory.
By omitting remark state-
ments and some of the
''frills/' you can cut the
size down considerably. By
using DATA statements
such as 1 did in this pro-
gram, you can easily add
new cities or make changes
to the countries list.
The version listed here
prints out the latitude and
longitude of the cities and
DX countries. After a few
initial runs to verify the
data, I went to a new ver-
sion in which 1 stopped
printing the latitude and
longitude for each loca-
tion.
Entering the data may
look like an enormous task,
but to me it was well worth
it. Hams can buy listings
similar to these from com-
mercial sources, but they
usually cost about SIO.OO.
Your local amateur radio
club members may be
more than willing to com-
pensate you for your ef-
forts.
A feature which I plan to
add to my program is an
alphabetical listing of ma-
jor cities around the world.
The World Almanac gives
the latitude and longitude
for a long list of North
American cities as well as
several world cities. I use
maps in the Rand McNalty
World Atlas for obtaining
the latitude and longitude
for other locations.
I hope that this program
will be as useful to others
as it has been to me.B
North Georgia's
2508 North Atlanta Road
Belmont Hills Center
Smyrna,
Georgia 300B0
Fhone (404^ 432-8006
only
Authorized
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Calf Books ARRL Books
M F J Saxton
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Cofuplelv siTvivp fuiililies
Call toll free 1-800-241-9961
M
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OTTO, NORTH CAROLINA a87fil
i^S4
178
t^ Reader Senftce — soe page 33i
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^1 k A
TM
Big Max Attacks
it's W2DU vs. K4KI
in the battle of the bazooka
M, Waher Maxwell W2DU
PO Box lis
Oaymn NJ 088W
Several years ago I was
faced with a perplexing
question: Why the popu-
larity of the so-called dou*
ble bazooka, while my
bazooka showed no vital
signs other than those ex-
pected of a simple half-
wave dipole? So, I per-
formed an autopsy.
The startling results of
the postnnortem examina-
tion were published in Ham
Radio, ^ and the graveside
rites were reported in
QSTJ Since then, it has
eluded incofrectly that it
still lives. 1 will uncover
these errors so that it can
be quickly reburied.
The 73 Magazine article^
reporting his reexamina-
tion of the double bazooka
(a misnomer for the coaxial
dipole) discloses some in-
teresting and valuable in-
formation. But it's unfor-
tunate that some portions
of the article are
misleading, and others are
totally incorrect (par-
ticularly the major conclu-
sionl making it impossible
for the uninitiated to
separate fact from distor-
tion.
k J.
cannot provide a worth-
while or significant im-
provement in bandwidth
for the effort expended
(even with stubs of oj!>-
timum impedance), unless
the feedline impedance is
considerably higher than
the usual 50 Ohms.
[rrors in the Reexamina-
tion Technique
Mr. Vissers agrees that
my conclusion is valid for a
free-space environment.
Nevertheless, because he
miscalculated the effect of
the ''big difference" be-
tween free-space and near-
earth antennas, his conten-
can't provide in free space,
by simply operating the
coaxial dipole near earth.
On the contrary, fustthe
opposite is true; the broad-
banding effect of the stubs
is less when the antenna is
near earth than when it is in
free space, not greater. In
view of Mr. Vissers' seem-
ingly plausible presenta-
tion, how can this be?
Don't his graphs showing
swr prove that the stubs are
working? Indeed they
don't. With all due respect
to Mr. Vissers, I regret hav-
ing to point out errors in his
treatment of antenna fun-
In examining the reasons
why he arrived at conclu-
sions that are directly op-
posite to the facts, we will
discover why the free-
space, thin-u^ire antenna
data used in my analysis is
relevant to antennas near
earth Furthermore, since
mistreatment of the fun-
damental concepts has
generated confusion far
beyond the realm of the
coaxial-dipofe antenna, I
feel compelled to discuss
the mistreated concepts in
sufficient depth to clarify
the confusion.
Validity of the Thin-Wire^
Free-Space Dipole
To begin, let's consider
the criticism concerning
thin wire for the dipolei
radiating elements. The
statement that there is no
such thing as ''thin-wire"
coaxial cable has no mean-
ing, because there is no
reference defining what
"thin" is. He has simply
misinterpreted "thin" to
mean vanishingly thin, in-
stead of following the stan-
dard practice of specifying
finite thickness of radiators
in terms of wavelength A.
On the contrary, the anten-
na terminal impedances
used throughout my
analysis are based
specifically on diameter D
of the outer conductor of
RG-58/U coax, where D =
0.140 inches = 0.0000445A
at 3J5 MHz, which is in-
deed a ''thin wire'^ at ttiis
frequency (see page 50^).
And in asserting that there
is a "big difference" in the
effect on bandwidth be-
tween free-space and near-
earth conditions, Mr.
Vissers must have
overlooked my measured,
near-earth data appearing
on page 48 in the Ham
Radio analysis/ and in
QST.^ The difference in the
effect between these two
conditions will be explored
in detail later on.
Improper Selection of Q
Spells Trouble in Fig« 8
Next, let's examine the
three swr curves appearing
in his Fig. 8. He used these
curves as the "theoretical"
basis for his conclusion
that the coaxial stubs in the
dipole are contributing
significantly to bandwidth.
However, because of an
improper selection of Q for
antennas near earth, these
swr curves are incorrect—
the true values are more
than double those shown.
Thus, the basis for his con-
clusion falls apart. AM of
the swr values in Fig. 8
were calculated based on
resonant antenna reac-
tances XLa ^^^ ^Ca (which
were unwisely obtained
from Q) in his Fig. 2. By in-
correctly assuming a Q of
10, the resulting 400 Ohms
obtained for reactances
Xl^ and X^a 's less than
half the true value of the
resonant reactances found
in antennas having the
dimensions of a typical
coaxial dipole resonant at
3.75 MHz (length L = 125
feet, and diameter D =
0.140 inches). Using the in-
correct 400 Ohms as the
basis for the swr calcula-
tions resulted in the op-
timistic, but impossibly-
low swr values in Fig. 8.
Ironically, when this error
in reactance is corrected,
and the affected arithme-
tic recalculated, the
resulting swr values are
nearly the same as those
obtained in my analysis.
Thus a conclusion similar
to mine must also follow.
Directly related to the im-
proper choice of Q in
determining the value of
XLa *^ the contention that
Q is lower when an anten-
na is near earth than when
it is in free space. The op-
posite is actually true. I
will show later how Q was
used improperly, why it is
unwise to obtain Xl^ from
Q, and why Q is higher
when an antenna is near
earth than when it is in free
space. I will also outline a
procedure for calculating
the value of XLa ^f'*^^^ the
L/D ratio, which entails less
chance for error than when
e.D
iJ 5 8
FREQUENCY IMMiJ
Fig. 1
using Q,
Obtaining Corrected Value
of Xc for Swr Calculations
So let's ignore Q
momentarily, and start
with the basic length-to-
diameter ratio L/D =
12570.140" = 10,714. From
this ratio, which deter-
mines antenna inductance
La and capacitance Ca in
his Fig. 2 (detailed pro-
cedure comes later), we ob-
tain the correct value of
846 Ohms for reactances
XLa ^^^ ^Ca ^^ the
3. 75-MHz resonant fre-
quency, instead of the in-
correct 400 Ohms shown in
Fig. 2. Using XLa = 846
Ohms in calculating the
off-resonance antenna
reactance X^ at 3,5 IsAHz
yields 117 Ohms, in con-
trast to the 55.24 Ohms in
Fig. 3. it's too bad this error
wasn't detected early on
by simply checking the
55.24 Ohms in a universal
graph of antenna resis-
tance and reactance versus
radiator length [or frequen-
cy), with L/D ratio as a
parameter. Such a graph
appears in the ARRL Anten-
na Book, and in many text-
books on antennas, such as
Jordan and Balmain/
Schelkunoff/ or King^ (and
in Figs. 2 and 4 of my
analysis-). Another way of
confirming the error will be
disclosed later.
Because of the simpli-
fied procedure used to ob-
tain it, this corrected off-
resonance reactance of
117 Ohms is still only an
approximate value. To
calculate antenna-terminal
impedances that agree
niore closely with the
measured data requires
more complex mathemat-
ical procedures, such as
those of Schelkunoff^ or
King/ from which univer-
sal impedance graphs are
generated. Thus from King
we obtain a more accurate
and realistic off-resonance
antenna reactance: Xc =
108 Ohms at 3.5 MHz for
our L/D ratio {see Table 2).
Impact of Wrong Xta *rom
Improper Selection of Q
To confirm the cata-
strophic impact on the con-
clusion, let's now compare
the results using the cor-
rect reactance with those
using the incorrect reac-
tance. First, using the cor-
rected value of reactance,
Xc = 108 Ohms with
resistance Ra of 40 Ohms,
we get a realistic swr of
7.75:1 at the antenna ter-
minals at 3.5 MHz instead
of the impossibly-low
3.27:1 shown in his Figs, 3
and 8. Why is the 3.27 im-
possibly low? Because to
obtain a raw, uncompen-
sated swr of only 3.27:1 at
3.5 MHz with Ra = 40
Ohms, it would require a
dipole diameter of 3.1 inch-
es—22 times larger than
the 0,14'' diameter of RC-
183
58/U coax. Remember, RG-
58/U is a thin radiator at 3,5
MHz]
Second, a 7.75;1 swr
agrees closely with data
obtained during hundreds
of my measurements of
similar conditions using a
General Radio rf im-
pedance bridge, Model
GR-1606A (also see Bor-
ton,^ Fig. 2). In contrast to
the ±10% accuracy
specified for the swr in-
dicator mentioned in the
73 Magazine article (which
cannot indicate reactance),
the General Radio bridge
has an accuracy capability
of measuring resistance to
within ±1%, and reactance
to within ±2%.
Third, re-solving the
parallel circuit problem of
his Fig. 5 using the cor-
rected reactance, Xc =
108 Ohms, instead of 55.24
Ohms, confirms the ca-
tastrophe, because the
original compensated re-
sistance of 116 Ohms
(which yielded the 2.33:1
swr) now becomes 331,6
Ohms when the parallel-
circuit reactance is can-
celed (using a shunt reac-
tance Xl of 122.8 Q, instead
of 853 Q). With a 331 .6-Q
resistance terminating a
50-Q line, the uncompen-
sated 7.75:1 swr is reduced
only to 6.63:1 (vs. 2.33:1 !)=
In proportion to the fre-
quency difference, the cor-
rected impedance, Z^ =
40 - j108 Ohms (7.75 swr),
agrees closely with my
measured data appearing
in the 80 meter example on
page 48 in my Ham Radio
analysis,' and in QSP: At
3.55 MHz (50 kHz closer to
resonance), I measured Za
= 50 - j90 Ohms (5.04
swr). With perfect compen-
sation the parallel-circuit
resistance is 212 Ohms,
reducing the 5.04 swr to
4.24. Thus the amount of
mismatch reduction is also
proportional. In addition,
at 3.5 MHz I measured Za
= 48 - jllO Ohms (6.90
swr). Note the close agree-
ment with the corrected
impedance, Za = 40 —
j108 Ohms, especially the
110-Ohm reactance com-
ponent. Bear in mind that
both my data were mea-
sured with the CR-1606A rf
bridge, and the corrected
data represent near-earth
conditions. Thus the errors
in the Vissers data are con-
firmed. And in view of the
close agreement between
the data of these near-
earth antennas and the
free-space data appearing
in Figs, 2 and 9b of my
analysis,^ the criticism of
using free-space data in my
analysis is clearly unjusti-
fied. More on this later.
Procedure for Obtaining
Xu (^nd Q) from the L/D
Ratio
Let's now see how the
resonant antenna reac-
tance, XLai 15 calculated
from the L/D ratio, from
which well see the dif-
ficulties both in obtaining
XLa from Q and in making
an accurate assumption of
Q unless XLa *^ already
known. The basic antenna
characteristic from which
values of antenna induc-
tance La and capacitance
Ca may be obtained for use
in the equivalent-series
RLC circuit of Mr. Vissers'
Fig. 2 is the average char-
acteristic impedance, Zq.
Antenna Zq is determined
uniquely by the physical
dimensions of the radiator.
The value of Zq may be ob-
tained from the length-to-
diameter ratio, L/D, using
the expression Zq = 120
(loge2L/D- 1) = 120(loge
3000/0,140 - 1) = 1076.7
Ohms (equation 1). Anten-
na inductance La and
capacitance Ca nnay now
be obtained from the ex-
pressions^ La = Zo/8fr
(equation 2) and Ca —
2/Ti^f,'Zo [equation 3),
where fp = resonant fre-
quency. Since Lg and Ca
are both dependent on L/D
and Zq, both the inductive
reactance, Xa, at reso-
nance and the equally
negative capacitive reac-
tance, Xca^ ^^^ ^'s*^ depen*
dent on L/D and Zq. Multi-
plying the expression in
equation 2 by co = 27tf, we
get the simple expression
for obtaining XLa: XLa ~
hZo/4 - 07854Zo =
845.64 Ohms (equation 4).
[Knowing Zq, here is the
other check method
Vissers could have used to
detect his reactance error,
which also confirms that
the correct antenna reac-
tance (Xa) at 3.5 MHz is
around 110 Ohms, not 55
(when resonant at 3.75
MHz). This method uses
the well-known expression
Xa = -Zo cot 1*^. At 3.5
MHz, the electrical half
length i = 90° X 3.5/3 J5
= 84*^. Thus, Xa =
-1076.7(cot 84^) =
-113.6 Ohms.]
Antenna Q can now be
determined from XLa ^^d
resonant resistance Ra us-
ing the expression^ Q =
XLa/Ra(resonant)(equation
5), Observe in equation 4
that resonant resistance Rg
(which is affected by prox-
imity to ground) does not
appear in determining the
resonant inductive reac-
tance XLai thus XLa '5 inde-
pendent of Ra^ However,
since XLa ^t resonance is
determined by L/D, it is rel-
atively constant, having
only a slight variation with
height above ground. In
equation 5 we see that Q is
dependent on XLa* s^id
also varies inversely with
the value of R^ at
resonance. Since R^ at
resonance varies appre-
ciably with height, decreas-
ing as height decreases
below 0.2 A, Q thus in-
creases as the antenna
height decreases. Since Q
and Ra both vary with an-
tenna height, we can't as-
sume to know the value of
either Q or Ra at some ar-
bitrary height for the pur-
pose of determining XLa^
unless accurate measure-
ments of both Q and Ra are
taken. Most amateurs
don't have the equipment
to perform these measure-
ments with sufficient preci-
sion to yield a good value
for XLa- And herein lies the
key to Mr. Vissers' error:
He has implied that the
assumptions for his R^ and
Q were based on his
measurements. Although
his assumption of Ra = 40
Ohms is realistic, his Q —
10 is not, because this com-
bination yields the er-
roneous XLa "^ 400 Ohms,
a value that can't exist with
an L/D ratio of 1 0,71 4 at
3.75 MHz. However, since
it is so easy to determine
the accurate length and
diameter of the radiating
element why not obtain
XLa directly from L/D as
described above? This way
we avoid the uncertainties
accompanying any at-
tempt to determine XLa
from Ra and Q. So let's
now correlate some perti-
nent values based on the
correct value of XLa (846
Ohms, obtained earlier
from L/D), which will em-
phasize the importance of
obtaining the correct value
of XLa* if calculations
based on this value are to
have validity.
Why a Q of 10 Is Incorrect
The resonant resistance
Ra of our RG-58 coaxial
dipole in free space with an
L/D ratio of 10,714 is 72
Ohms (73.13 Ohms when
L/D = oo^ see KingO, and
the value of XLa f^om
equation 4 is 846 Ohms.
Thus, from equation 5, the
free-space Q of the dipole
is 846/72 = 11.75. How^
ever, when the antenna is
at a height where Ra is
reduced to 40 Ohms, the Q
increases to 846/40 =
21.15, in contrast to Mr.
Vissers' value of 10. On the
other hand, if this arbi-
trarily-chosen Q of 10 were
realistic with an Ra = 40,
the value of XLa really
would be 400 Ohms.
However, this Q of 10
would have come from a
free-space Q = 10 X 40/72
= 536, which defines an
entirely different antenna.
In fact, as stated earlier, a
value for XLa ^^ ^00 Ohms
at 3.75 MHz requires that
diameter D = 3.1 inches.
184
22 times thicker than that
of RC-58/U, for an L/D ^
487. To use Mr. Vissers'
own words, that is a big dif-
ference!
Elfect of Height on
Antenna Q
The subject of antenna
height and its effect on Q is
another area of concern in
the 7^ Magazine article,^
because two conflicting
concepts appear that are
rather puzzling. On one
hand, he used the expres-
sion Q — XLa/l'a (^^^L'^^'^'i
5), and its inversion XLa ^
Ra ^ Qi which state cor-
rectly that when R^
decreases, Q increases. On
the other hand, ''after
much thought" concerning
the results of his measure-
ments, he concluded that
because of the unavoid-
able losses incurred when
the antenna is near ground,
the Q is lower than when
the antenna is in free
space. This conclusion is
puzzling, because it is well
known that when dipole
height is less than 0.2A, the
antenna resistance, Rg, is
less than the free-space
value. Since equation 5
shows that Q varies in-
versely with Ra, antenna Q
near ground becomes
higher than the free-space
value, rather than lower.
This discrepancy in his con-
clusion, and the erroneous
assumption that Q = 10,
raises serious questions
concerning the measuring
equipment, technique, and
evaluation of the data.
Now, the matter in which
Ra changes with height
over actual ground {in con-
trast to perfectly-conduct-
ing ground) is complicated
by several factors, in-
cluding the dissfpative
losses he mentioned How*
ever, the actual value of Ra
is determined by the in-
tegrated effect of all the
contributing factors in any
given set of ground-prox-
imity conditions. Thus the
value Ra — 40 Ohms in-
cludes the effect of these
losses, and Ra ^nd XLa
determine the Q actually
existing under those condi*
lions. On the other hand, if
the ground were perfectly
conducting, the mutual
coupling between the an-
tenna and its ground-
reflected image would be
greater for the same
height, due to the absence
of the ground losses. When
height is less than 0.2A, this
larger coupling results in a
lower value of Ra, and a
correspondingly higher Q
than when the antenna is
over actual ground.
Perhaps he really meant
that because of the
ground-associated losses,
the Q of an antenna over
actual ground is lower (and
the Ra higher) than // it
were over perfectly-con-
ducting ground. In any
event, the Q of an earth-
oriented antenna is higher,
not lower, than the same
antenna in free space.
Thus, it is not true that "be-
cause earth-oriented an-
tennas have a lower Q"
they yield a greater degree
of bandwidth improve-
ment using shunt-stub
compensation than those
in free space.
Ignoring Feedline Attenua-
tion Spells Trouble in Fig* 9
Let's now examine Fig. 9,
which is called the 'proof
of the pudding " The exper-
imental data of Fig, 9 is
said to prove that the co-
axial dipole is working,
because it is said to cor-
relate with the theoretical
data of Fig. 8 (which we
have shown to be er-
roneous), and because "it
indicates that the swr im-
provement is even better
than the calculations pre*
dieted." Unfortunately,
Fig. 9 provides no such
proof On the contrary. Fig.
9 reveals that he shares a
widespread misconception
concerning the correlation
between theoretical and
practical aspects of anten-
na systems evaluation. In
reality, the graph in Fig. 9
proves only that the swr
values shown are those
measured at the input to a
feedline, and that some
amount of change in swr at
the load (antenna) resulted
from changing the stub
conditions. Regardless of
the caption, the graph
reveals no quantitative
data whatever concerning
swr at the antenna,
because the true dipole
swr values are masked by
an unknown feedline atten-
uation between the line in-
put and the antenna ter-
minals. It's like trying to
identify a pea beneath a
mattress, because we know
both from the corrected
calculated data and from
measurements that the
true values of dipole swr
are nearly 2Vi times larger
than those shown in Fig, 8.
Necessity for Line-Attenu-
ation Data
If the swr is measured at
the feedline input simply
to ascertain transmitter
loading conditions, then
Irne-attenuation data is un-
necessary. On the other
hand, if the line-input
measurements are for as-
certaining the matching
conditions at the antenna,
then feedline-attenuation
data is absolutely essen-
tial. The attenuation data
is needed to obtain the
input-output proportionali-
ty factor required to
calculate the magnitude of
the reflection coefficient
[mismatch) at the load
from that measured at the
input. But no attenuation
data is given for the curves
in Fig. 9, Thus the numbers
on the scale labeled
"MEASURED SWR" are
meaningless with respect
to swr at the antenna,
because their mathemat-
ical relation to the antenna
terminals is unknown. If the
line attenuation were zero
[which it isn't), then the
curves, as labeled, would
represent the true swr
values of the antenna. On
the other hand, if the atten-
uation were 2-06 dB> then
the 2.85:1 swr of curve A at
3-5 MHz would represent
the recalculated 7.75:1 swr
appearing at the antenna
terminals. Thus, to indicate
swr at the antenna, the
scale factor of the
"MEASURED SWR'' scale
must be tailored to fit the
line input-output propor-
tionality factor obtainable
only from the line attenu-
ation. A procedure for ob-
taining this proportionality
factor IS outlined (with
solved examples) in Appen-
dix 4 of my analysis in Ham
Radio.^
The data in Table 1 illus-
trates the necessity of at-
tenuation data, showing,
for example, that by simply
increasing the line attenu-
ation from 2.06 to 3.18 dB,
a 2.85:1 swr would still ap-
pear at the feedline input
with the far end either
short circuited, or left open
circuited. In other words,
by measuring at the line in-
put, one could not distin-
guish between the separate
loads of either zero Ohms
or an infinitely-high
With Line
Attenuation
0.0 d8
0.25
0.5
1.0
1.5
2.0
2.06
3.0
3.18
4.0
5.0
Swr at Line Input
When Load Z|_ =
When Load Zl = SC (0 Ohms) or
40)1 08 Ohms OC (" Ohms)
7J5
6,36 34.a
5.40 17.4
4.17 8.7
3.41 5,85
2.90 4.42
[2.85] 4.30
2.26 30
2.18 {2.85)
1.B9 2,32
1.64 1.92
Table 1. SC = short circuit; OC = open circa h.
185
resistance.
Murphy Nearly Scored, but
Two Wrongs Don't Make a
Right
The fortuitous similarity
of the incorrect theoretical
data in Fig. 8 and the
meaningless measured
data in Fig, 9 is unfortunate
and misleading because,
for those unfamiliar with
the effects of line attenu-
ation, the comparison of
these figures supports the
widespread misconception
that measurements at the
line input directly indicate
conditions at the antenna.
And indeed, this mis-
conception trapped Mr,
Vissers into the most cata-
strophic error in his
coaxial-dipole projects,
because it misled him to
believe that his stubs were
performing well, even
though they were perform-
ing as described in my Ham
Radio analysis. By ignoring
the effect of feedline at-
tenuation, the accidentai
agreement between the
low-swr values of Fig. 9
measured at the line input
and the unsuspected, in-
correct, theoretical anten-
na swr data in Figs. 3 and 8,
misled him to believe that
both graphs were correct
and valid antenna terminal
data, and that the mea-
sured data supported the
theoretical data. On the
contrary, if he had cal-
culated in the effect of the
feedline attenuation on the
line-input swr values of Fig.
9, he would have obtained
values of dipole swr that
are vastly greater than
those of Fig. 8 at the corre-
sponding frequencies. This
discrepancy would have
alerted him to go back and
find the initial error (the
wrong value of Xl^} in
calculating the Fig 8 data.
This is the second oppor-
tunity at which the error
could have been detected.
Had the error been de-
tected at either point, the
case for the coaxial dipole
would have evaporated.
Unfortunately, it is fairly
common to see published
curves purporting to show
measured antenna band*
width characteristics, with-
out providing any feedline
attenuation information.
Such curves convey no
more clues to truth in
antenna performance than
Mr. Vissers' Fig. 9, so he is
not alone.
In addition to line at-
tenuation, there are other
factors that contribute to
misleading indications
when measuring swr at the
line input More often than
not, swr-indicator readings
are somewhat lower than
the real swr values appear-
ing at the line input And
with the coaxial dipole, the
externa! dielectric cover-
ing on the coax-cable
radiator causes a mild in-
crease in antenna band-
width, from the combina-
tion of increased antenna
capacity Ca and addi-
tional ohmic loss due to
dissipation in the dielec-
tric. (I raised this point in
QSr^) These factors make
it impossible to calculate
the true terminal im-
pedance and swr of the
dielectric-covered dipole
[for Fig, 8) with any degree
of certainty, although the
swr is certain to be
somewhat less than the
7.75:1 that we calculated
previously for a bare wire
of D — 0,14 inches. The
best way to find out for
sure is to determine the at-
tenuation of the feedline
used in obtaining the data
for Fig. 9, re-measure the
data with an accurate im-
pedance bridge, and then
perform the calculation to
transfer the swr values at
the feedline-input ter-
minals to the antenna ter-
minals.
Impedance Relations in
Free Space Versus Near
Earth
Let's now return to the
discyssion concerning the
effect of free-space versus
near-earth conditions in re-
lation to antenna imped-
ance and bandwidth, to
discover why Mr. Vissers'
belief that the coaxial
dipole performs better
near earth is erroneous He
agrees with the conclusion
in my analysis that the
reactance shunting used in
the coaxial dipole is inef-
fective for increasing band-
width when the dipole is in
free space and fed with
50-Ohm feedline. How-
ever, he believes this
technique is effective with
lower antenna resistance,
R^, as found in 80 meter
antennas at normal
heights. Unfortunately, in
expecting an improvement
in the broadbanding capa-
bilities of reactance shunt-
ing by reducing resistance
Ra from the free-space
value of 72 Ohms to
around 40 Ohms, he is
overlooking two basic prin-
ciples of impedance
matching, one underlying
the shunt-reactance meth-
od of increasing the band-
width, and the other con-
cerning the minimum-swr
resistance in a complex
load impedance. The vital
aspects of the shunt-reac-
tance method that were
overlooked are disclosed
in my Ham Radio analysis^
(page 50), and the mini-
mum-swr resistance princi-
ple is described in a paper I
published in QST.* How-
ever, the following discus-
sion may be helpful in
clarifying the conflict.
In the conventional
method of matching, an-
tenna resistance Ra, at re-
sonance, is usually nearly
equal to the line im*
pedance, Zc Typically, Ra
can be anywhere from 40
to 72 Ohms when Zq — 50
Ohms (a 1.4:1 mismatch is
considered insignificant).
With this nearly one-to-one
ratio between the line and
load impedances at reso-
nance, the mismatch rises
continuously on either side
of resonance, because the
ratio between the two im-
pedances increases, due to
the increasing reactance,
Xg. Now if we simply add
reactance shunting to the
antenna terminals to can-
cel the antenna reactance,
the shunt reactance cannot
perform effectively in re-
ducing the mismatch off
resonance, as long as the
impedance ratio is already
nearly one-to-one at reso-
nance. The reason is be-
cause the shunt reactance
cannot yield a significant
reduction in the off-
resonant antenna imped-
ance— it can only ex-
change a reactive terminal
impedance for a nearly-
equai resistive impedance.
Thus the impedance ratio
remains high, and as I ex-
plained in the analysis '
and illustrated with a
numerical example in
QST,^ when the feedline-to-
antenna impedance ratio is
high, the mismatch is near-
ly the same whether the
antenna terminal imped-
ance is reactive or resis-
tive. Thus the shunting is
ineffective, as shown in
Fig. 10B in my analysis, and
in Fig, 1 in this article.
On the other hand, con-
sider the relationship
where the feedline-to-an*
tenna impedance ratio is
within the range where the
shunt-reactance method
can perform effectively-
By using a feedline of
higher impedance, in-
creased by a factor of two-
to-one or more (and ac-
cepting a similar com-
promise in mismatch at
resonance), the ratio be-
tween the reactive off-res-
onant antenna impedance
and the line impedance is
reduced proportionally.
With this lower off-res-
onance impedance ratio,
the exchange of a reactive
load impedance for a resis-
tive impedance resulting
from the reactance shunt-
ing now yields a significant
reduction of off-resonance
mismatch, as Fig 4 of my
analysis shows.
The Crucial Factor in the
Resistance Versus Off*
Resonance>Mismatch Reia-
tionship
The crucial factor in this
186
relationship is this: The
vital reduction of the off-
resonant, Itne-to-antenna
impedance ratio obtained
bv increasing the line im-
pedance cannot be du pli-
cated by reducing the an-
tenna resistance Ra unless
the antenna reactance Xa
is also reduced proportion-
ally, because it is mainly
the off-resonance reac-
tance that causes the high
antenna impedance. Natu-
rally this inherent reac-
tance cannot be reduced
unless the radiator itself is
redesigned. So when the
resistance is reduced
without also reducing the
reactance, the off-
resonance impedance rela-
tionship is entirely dif-
ferent from that obtained
by increasing the line im-
pedance.
To discover how reduc-
ing only the resistance Ra
affects mismatch, let's ex-
periment with a dipole,
Starting with R^j — 72
Ohms at resonance, we'll
make a series of frequency
excursions to the ends of
the band, and at each suc-
cessive excursion we'll
reduce only the resistance,
so that all values of Ra ver-
sus frequency are lower
than those of the preceding
excursion. The result is that
at any frequency where the
swr exceeds about 2:1, the
mismatch and swr become
LARGER as the resistance
becomes LOWER. And the
greater the swr, the less im-
provement reactance
shunting can provide, for
the reason explained
earlier. So while the
mismatch improvement by
reactance shunting is
already insignificant when
Ra = 72 Ohms (as Mr.
Vissers agrees), it becomes
worse when Ra — 40
Ohms, not better.
It is true that reducing
the resonant antenna
resistance from 72 to 40
Ohms improves the in-
herent match slightly in the
region near resonance
{from 1.44 down to 1.25:1).
However, this is not the
region where mismatch
reduction is needed; the
reduction is needed in the
regions toward the band
ends, where the inherent,
uncompensated swr ex-
ceeds 2:1, and it is in these
regions where Mr, Vissers'
theory fails, and where the
shunt-reactance method
cannot provide significant
improvement for a thin
dipole when fed with a
50-Ohm feedline.
The relationship be-
tween resistance and off-
resonance mismatch is
shown in Fig. 1 (a graph
from data of Table 2, which
will be explained shortly),
where we can see the
significant difference in
the way dipole swr changes
between frequencies near
resonance and those
nearer to the band edges,
depending on whether the
antenna resistance Ra at
resonance is 52 Ohms or
the free-space value of 72
Ohms. With the 52 Ohm
antenna the match is near-
ly perfect at resonance,
and thus remains some-
what better than the
72-Ohm antenna out to
around a 2:1 swr. However,
at frequencies where the
swr is greater than 1.7:1
below resonance, and 2.2:1
above resonance, the
match is consistently
worse with the 52-Ohm
antenna. From calcula-
tions not shown in Table 2,
the match quality of an
antenna having a 40-Ohm
resonant Ra deteriorates
much more rapidly than
the 52-Ohm antenna, espe-
cially near the band-edge
frequencies where we need
the mismatch reduction
the most.
The Basis for the Graphs
and Tables
The swr values appear-
ing in Fig. 1 and Table 2
were calculated from the
terminal impedances of
both a free-space and an
earth-oriented dipole, with
%'0
2
10
4
SO
0 it 1* 16 18 ?0 22 2*
^0 40 ^Q BO fO 80 90 lOO MO 120
Fig, 2,
three different stub-
matching conditions for
each: 1) no stubs; 2)
25-Ohm stubs; and 3) op-
timum stubs. To make a
valid comparison of the
mismatches associated
with these different stub
conditions requires au-
thentic impedance data.
Because dipole resistance
R^ changes significantly
with frequency [see Table
2), it is improper to
calculate the mismatches
using a constant resistance
Ra = 40 Ohms across the
band (as Mr. Vissers has
done). Therefore, the free-
space data appearing in
Fig. 1 and Table 2 is authen-
tic impedance data taken
from King/ the same as
used in my analysis.^
For the earth-oriented
impedance data, resis-
tance values of Ra ~ 20
Ohms were selected for
each corresponding fre-
quency, to allow for the
mutual coupling to the im-
age dipole. The constant
20-Ohm difference be-
tween free-space and
earth-oriented resistance
versus frequency repre-
sents only a small com-
promise with the actual
change in mutual re-
sistance Rm across the
band, and the R^ —
20-Ohm values closely
represent those obtained
with the reflection coeffi
cient of average ground.
Exceptionally high ground
conductivity beneath the
antenna is required to ob-
tain values much less than
40 Ohms anywhere within
the band at any height us-
ing a straight dipole,
although lower values can
be obtained with inverted-
Vs having included angles
of considerably less than
180 degrees. The Ra —
2D-Ohm values include 68
Ohms at 4.0 MHz, 52 Ohms
at resonance, down to 38.5
Ohms at 3.5 MHz.
At average 80 meter
antenna heights, the
mutual reactance Xm i^
small, so the change in ter-
minal reactance Xa
with height is negligible, as
confirmed by extensive
measurements. Therefore
the same values of Xa were
used in both the free-space
and earth-oriented condi-
tions. Of course, earth-
oriented impedances vary
with location. However,
the impedances selected
as previously described are
typical of the average
amateur situation, and are
valid for demonstrating the
general relationship be-
tween antenna resistance
and mismatch (both with
and without stubbing). In
other words, measured
values are not expected to
repeat the data in Table 2
exactly, but in general the
improvements due to stub-
bing will be fairly propor-
tional to those appearing in
Table 2. It should be kept
in mind, as explained
earlier, that with 50-Ohm
feed line, the ratio of off-
resonance antenna-to-
feedline impedance is too
high for the stubbing to
have a significant effect.
However, it should be
clearly understood that the
187
Table 2 values showing swr
improvement are the
precise values that will
result strictly from the
shunt reactance alone for
the given impedance con-
ditions—no greater im-
provement than this can be
obtained from the shunting
itself, because the calcula-
tions based on pure,
lossless reactance yield
precise answers. However,
if measured values do in-
dicate a significantly
greater amount of im-
provement than shown in
Table 2 under the same
conditions of uncompen-
sated impedance, it means
that additional phenomena
are also contributing to the
effect obtained with
lossless stubs. Such phe-
nomena include ohmic loss
of the stubs which we
haven't considered {the ac-
tual stubs aren't lossless),
and the effect of the exter-
nal dielectric, which is a
separate contfibution that
is practically impossible to
predict But remember,
any such "improvement"
resulting from ohmic loss
represents power that isn't
radiated.
The Minimum-Swr-Resis-
tance Principle
When a load terminating
a feed tine is resistive, as in
an antenna operating at
resonance, the mismatch
between the line and the
load impedances is found
by simply dividing the
larger impedance by the
smaller. However, as with
all amateur antennas,
when the load is the com-
plex impedance Za = Ra
+ jXa of an antenna
operating off resonance,
the relationship between
line impedance Zq and mis-
match is no longer a simple
one. So appreciation of the
swr values in Fig. 1 and
Table 2 is understandably
difficult. Directions for
calculating the swr values
are outlined in Appendices
1 and 2 of my analysis,^ but
textbook study is required
for an in*depth apprecia-
tion of the concepts.
However, although not
well known among ama-
teurs, the minimum-swr-
resistance' principle pro-
vides an elegant means for
correlating complex load
impedance with feedline
impedance in a way that
provides an unusual view-
point in appreciating the
effect of resistance on the
match quality when the
load contains reactance.
So let's examine the
minimum-swr-resi stance
principle.
In a series complex load
impedance, Zl, comprising
a resistance R and reac-
tance X, if the resistance is
varied but the reactance is
not, there is a single value
of resistance, Rmswrfcalled
the minimum-swr resis-
tance), that will cause the
load to produce a mini-
mum of mismatch when
terminating a generator or
tine. Unless X = 0, Rmswr
will be greater than the line
impedance Zq. When the
component values in the
load are normalized to the
line impedance Zq
(yielding RIZq — r, and
X/Zc = x), the value of the
normalized minimum-swr-
resistance r^swr ~ V^' + T
(equation 6),' When the
load Zl = Rmswr + J^. the
mismatch value equals the
sum of the normalized
components of the load;
I.e., swr = rrnswr + ^
(equation 7).*
This principle tells us
that for a given value of re-
actance, X, in a load in
series with resistance
Rmswr. any change in
resistance (either higher or
lower) will cause the swr to
rise. For example, let's find
the value of Rmswr ^^^ 3
reactance X = 50 Ohms
with a 50-Ohm line, and
compare the mismatch the
combination produces
with the mismatches from
two other impedances hav-
ing the same reactance,
but one having a higher
resistance and the other a
lower resistance. Thus, Zl
= Rmswr + JSO Ohms, and
by normalizing becomes z
= Rmswr + H 0. The value
of ^'mswr (determined
solely from x) is \/x' + 1 =
\/V + 1 = V^ = 1.414
De-normalizing, Rmswr =
50 X r,414 = 70.71 Ohms,
so the desired impedance
is Zl = 70.71 + 150 Ohms.
The swr produced by this
impedance is r^swr + x =
1 414 + 1 = 2 414, the
minimum-possible swr
when X = Zc = 50 Ohms.
(This treatment works only
when r = rnnswr) Now, us-
ing the expressions from
Appendices 1 or 2 in my
analysis^ to calculate the
swr produced by general
complex load impedances,
we find that impedances
Zl = 50 + j50 and 100 +
jSO both yield the identical
value of swr = 2.618:1,
which is higher than the
minimum-possible 2.414:1
produced by the im-
pedance 70.71 -h j50
Ohms. Additional calcula-
tions show that as the
resistance goes either
lower than 50 Ohms or
higher than 100 Ohms, the
swr continues to rise above
2.618:1. For example, Zl ==
25 + jSO yields 4.266:1,
and 125 + j50 yields
2,962:1. However, note
that the swr rises slowly as
R increases above 100
Ohms, but rises rapidly
when R decreases below 50
Ohms,
This minimum^swr-
resistance principle is com-
pletely general, working
for any value of reactance
X and line impedance Zc,
Thus we have a powerful
tool for investigating any
complex antenna-terminal
impedance Zg as the load
for determining which
direction the swr will go
with a change in resistance
Ra. Fig. 2 contains a plot of
Rmswr versus reactance X
(including the normalized
values for x) for values of X
from zero to 120 Ohms
with a line impedance Zq
of 50 Ohms, For conve-
nience, the corresponding
minimum-possible-swr
values are also plotted. To
use the graph in determin-
ing whether the swr will
rise or fall with a given
change in antenna resis-
tance Rfl, we first deter-
mine the reactance compo-
nent Xa of the antenna im-
pedance. From either the
grapK or equation 6, we
then find the correspond-
ing minimum-swr-resis-
tance, Rmswr- 1^ resistance
Ra is lower than Rmswr^
raising the value of Ra will
reduce the swr (until Ra =
Rmswr). stnd vice versa. If
Ra is higher than Rmswr^
raising the value of Rg will
increase the swr, and vice
versa. Since Rmswr *s 50
Ohms when X = 0, Rmswr
does not go lower than 50
Ohms. Thus if resistance
Ra is less than 50 Ohms, in-
creasing the value of Ra
will decrease the swr for
whatever the value of reac-
tance Xa, including Xa —
0. However, to reach the
minimum-possible swr
when any reactance is pres-
ent, resistance Ra must be
higher than 50 Ohms, and
the greater the reactance,
the higher resistance Rg
must be raised.
Verification Using the
Minimum-Swr-Resistance
Principle
Turning now to Table 2,
the values of minimum-
5 w r- res i stance Rmswr
listed there tfrom the data
of Fig, 2) are the values
which yield the lowest
possible mismatch when in
series with the correspond-
ing reactance X^ at the in-
dicated frequency. In other
words, if resistance Rmswr
for the corresponding reac-
tance were to replace the
actual antenna resistance
Ra. we would obtain the
lowest swr that is possible
with that particular reac-
tance Xa in the circuit, The
values of the correspond-
ing minimum-possible swr
are also listed in Table 2.
In using this technique
to confirm our previous
conclusions based on
calculated values of swr,
let's first examine the con-
188
Mismatch
or Swr
FmHz
Antenna Imped
ance
Uncompensated
Compensated
Compensated
Components'
dlpofe
wHh 2SQ
wrth opt
[imum
stubs
stubs
Ohms
Ohms
Ohms
Mia.*
Free-
Near-
Free-
Near*
Free-
Near-
Resistance
React.
Resis.
Possible
Space
Earth
Space
Earth
Space
Earth
"a
Ra'20
Xa
Rmswr
Swr
Ra
Ra20
Ra
Ra'20
Ra
Ra'20
3.5
58.5
38.5
-103.00
119.0
4.54
5.84
8.00
5.50
7.50
5,16
6.83
3.55
60.8
40.8
•86 50
99,9
3J3
4,27
5.53
4.04
5.19
3.71
4.58
36
63,4
43.4
-64.79
81.8
2,93
3.05
368
2.92
3.49
2,67
3,03
3.625
64.75
44.75
-53.94
73.55
2.55
2.58
2,98
365
66 J
46.1
-43.08
66.0
2.18
2.18
2.39
2.12
2.30
1.97
2.03
3.675
67.6
47.6
-32.24
59.5
1.83
1.86
1.92
3.69
68.5
48.5
-25.74
5624
1.64
1.70
1.68
3.7
69.1
49.1
-21.40
54.4
1.52
1.62
1,54
1.60
1.50
1.54
1.38
3.75
72.0
52.0
0
50.0
1.00
1.44
1.04
1.44
1,04
1.44
1.04
3.8
75:1
55.1
21.92
54.6
1.53
1.71
1.53
1 .69
1.50
1.69
1,49
3.825
76.6
56.6
32.80
59.8
1.85
1,95
1.86
3,85
78.2
58,2
43.58
66.3
2,20
2.24
2.23
2.19
2.15
2.14
2.05
3.9
81.3
61.3
65.24
82.2
2.95
2.95
3.11
2.85
2.97
2.74
2.77
3.95
84.8
64.8
87.15
100.5
3.75
3.81
4.17
3.61
3.96
3.51
3.69
4.0
88-0
68.0
109.24
120.1
4.59
4.83
5.42
4.61
5.13
4.47
4.87
Table 2.
ditfons at 3.825 MHz. At
this frequency the lower-
height (Ra - 20, or
52-Ohm} antenna yretds a
slightly better match near
resonance because its
52-Ohm resonant resfs-
tance is nearer to the
50-Ohm line impedance
than the 72*Ohm free-
space antenna, From Table
2. at 3.825 MHz, Xa = 32.8
Ohms, and the minimum-
swr-resistance Rmswr —
59.8 Ohms. If the actual
resistance Ra ^ 20 were
59.8 Ohms, the swr would
be 1,85:1, the lowest swr
possible with 32.8 Ohms of
reactance in the circuit.
However, at this frequency
the actual resistance R^ —
20 — 56.6 Ohms nearly
equals the minimum-swr
resistance, yielding a 1.86:1
swr for the 52-Ohm anten-
na (only slightly higher
than the minimum), in con-
trast to the higher
value Ra = 76,6 Ohms for
the free-space antenna,
with a 1.95:1 swr. This ex-
plains why the 52-Ohm
antenna yields a slightly
better match than the
72-Ohm antenna at this fre-
quency.
On the other hand, at 3.5
MHz the minimum-swr-
resistance technique
demonstrates rather
dramatically why the off-
resonance mismatch in-
creases when the antenna
resistance at resonance is
reduced Again from Table
2, at 3,5 MHz the reactance
Xa = -108 Ohms is shown
to require a resistance
Rmswr of 119 Ohms to ob-
tain the lowest-possible
swr, which is 4,54:1, The
free-space and near-earth
dipole resistances at 3.5
MHz are 58.5 Ohms and
38,5 Ohms, respectively.
Thus, the free-space
resistance is 60.5 Ohms
below the optimum 119
Ohms, which increases the
swr to 584:1. However,
with the 38,5-Ohm
resistance of the near-earth
antenna, the swr has
soared to 8,0:1, because
the 38.5-Ohm resistance is
20 Ohms lower yet than the
free-space value, or 80.5
Ohms below the optimum
value. Now, since the free-
space value of 58-5 Ohms
is already 60.5 Ohms below
the optimum value of
Rmswr «^f 119 Ohms, it is
clearly evident that to ob-
tain a lower swr than the
free-space value of 5.84:1,
the resistance Ra must be
increased, rather than
decreased. Moreover, an
examination of all remain-
ing data points listed in
Table 2 reveals that the
values of Rmswr ^"^
minimum-possible swr con-
firm the direction in which
every value of dipole swr
changed resulting from a
corresponding change in
dtpole resistance Ra.
As an additional point of
interest, compare the
curves appearing in Fig. 8
of the 73 Magazine article*
with those of my Fig, 1, and
note the asymmetric shape
of my swr curves with
respect to the center fre-
quency of 3,75 MHz. While
the ( + ) and { — ) reac-
tances, X^, are almost sym-
metrical [see Table 2\ the
values of swr below center
are higher than those at the
same difference in fre-
quency above center. The
reason is that resistance Ra
is decreasing below center,
and increasing above, and
the swr values are simply
following the minimum-
swr-resistance principle.
On the contrary, the
Vissers curves are unreal-
istically symmetrical,
because in his swr calcula*
tions the constant value Ra
= 40 Ohms was used
(incorrectly) across the en-
tire band.
Conclusion
In comparing the swr
curves of the 72-Ohm and
52-Ohm antennas in my
Fig. 1, it is evident that no
great dramatic difference
exists between them.
However, these two curves
represent the effect of the
"big difference" that was
asserted to exist between
my free-space 72-Ohm
dipole and a dipole near
earth. This is the "big dif-
ference" that was pre-
dicted would change the
insignificant stub contribu-
tion in my "irrelevant"
free-space coaxial dipole
into a workable, worth-
while contribution by
"bringing the dipole down
to earth/' Obviously, the
dramatic change that was
predicted doesn't materi-
alize, and the positions of
the curves in my Fig. 1 in-
deed show that the dipole
near earth is even less ef-
fective than when in free
space. Thus, despite
Vissers' statement to the
contrary, these curves
more than justify the use of
free-space data in my
analysts that enables the
amateur to recognize the
conditions under which the
stubs in a coaxial dipole
will or will not provide a
worthwhile improvement
in bandwidth.
Perhaps not everyone
will agree on just what con-
stitutes a worthwhile,
significant improvement in
swr. So if anyone decides
the meager improvement
shown in Fig. 1 and Table 2
is worth the constructional
effort and cost required to
109
obtain it with shunt stubs,
fine and dandy. But if you
appear to be measuring
considerably more band*
width at the antenna than
indicated in Fig, 1, you are
quite likely to be fooling
yourself. Remember that
unwanted ohmic losses
can raise an otherwise-low
terminal resistance, thus
reducing the swr via the
minimum-swr principle,
but at the expense of losing
power to heat. In any case,
as a professional antenna
engineer, my boss would
hand me my head on a plat-
ter within seconds if I
seriously presented him
with this shunt-stub
method as a viable solu-
tion to the 80 meter broad-
banding problem when us-
ing 50-Ohm feed line. ■
Addendum
Mr Vissers raised an im-
portant point concerning
Borton's work,' in that my
analysis failed to mention
the swr differences Borton
obtained between a coax-
ial dipole and the bow-tie
antenna constructed from
galvanized wire. There are
two reasons why I omitted
reference to this topic:
First, my article was
already too long. More im-
portantly, several cloudy
issues concerning both of
these antenna forms need
clarifying before I can
discuss them knowledge-
ably.
For example, in the coax-
ial dipole: What precise,
quantitative effects result
from the external dielectric
covering? Well, Zq. XLa,
and Q are all reduced by
the resulting increase in
antenna capacitance Ca.
But how much? Does this
yield an efficient increase
in bandwidth? And how
much does the dielectric
covering increase the
dissipation loss, reducing
the efficiency while raising
the terminal resistance and
reducing the swr? As I
stated in Q5T,^ further in-
Choosy Feogle
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Communications
vestigation is necessary^
Concerning the galva-
nized wire, the higher
resistance of the zinc
covering is probably caus-
ing the lower swr, but more
investigation is required
here also: What is the
thickness of the galvaniz-
ing? Is it greater than the rf
skin depth at 4 MHz? If so,
what is the total series sur-
face resistance at rf? Com-
pared to copper? Enough
to account for the dif-
ference in swr? Does the
magnetic effect of the iron
in the wire influence the
phase velocity of the rf
wave? So far, I have been
unable to pursue these
questions. I had planned
future collaboration with
Borton for f uther investiga-
tion into the rf properties
of galvanized iron wire. I
regret that such collabora-
tion is no longer possible,
because Dwight Borton
recently became a silent
key. I will think of him as I
proceed alone.
References
1. Walter Maxweli W2DU, "A
Revealing Analysis of the Co-
axiat'Dipole Antenna/' Ham
Radio, August. 1978, p. 46.
2. Walter Maxwell W2DU, *'Th©
Broad-Band Double-Bazooka
Antenna — ^How Broad ts It?",
QST. September, 1976. p. 29.
3. William Vissers K4KK "Build
A Double Bazooka " 73 Maga-
zine, August, 1977, p. 36.
4. Jordan and Salmain, Elec-
tromagnetic Waves and Radh
afrng Systems, 2nd Edition^
Prentice-Hall, Englewood Cliffs
NJ, p, 548. (Caution: Values
shown are for monopolei muith
ply by 2 for dipole.)
5. fbid., p. 388.
6. SchelkunofI and Friis, Anten-
nas, Theory and Practice^
Wiley, 1952, pp. 436-455.
7. Ronold W. P. King, Theory of
Linear Antennas, Cambridge
University Press, Cambridge
MA. p. 176.
a Walter Maxwell W2DU, "An-
other Look At Reflections."
Part 5, QST, April, 1974, p. 161,
equation 11,
9. Dwight Borton W9VMQ,
"Wide-Bandwidth Bow-Tie Ah*
tenna for 90 Meters/* Ham
Radio, May; 1975, p. 56.
January 27-28, 1979
/
Convention
CrlQth AnnuQl
TROPICAL Hnm&OREL
FUBIER DOG TRACK ^'^^ ^ ' '
I V f I *^ 1^ t -
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Standard Communicalions Corp. • P.O. Box 92151, Los Angeles, CA 90009
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190
1^ B&adm Service— see page 323.
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Model 594~DPDT
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loss and crosstalk negligible.
Made m U SA by
AT-200 Mobile Matcher
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lets you avoid advertising you
have a rig in the car by matching
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antenna to your transceiver
Trap DIpole Antennas
5-Band (80 thru 10)
Model 370-11 pre-assembled
Model 370-12 kit
4-Band (40 thru 10)
Model 370-13 pre-assembled
Includes end insulators, 50 ft
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191
The Packet Radio Revolution
pioneers, take note!
!
Editor's Note: Shortly before press time, the Canadian authorities announced the creation of a new "Amateur Digital Radio 0| ator's
Certificate/' a no-code license allowing certain experimenter privileges, including packet radio, \n the amateur bands above ' t MHz.
Certain portions of the 220 and 440 MHz bands hawe been reserved exclusively for packet transmissions.
Robert T. Rouleau VE2PY
1050 Churchill
Monireat, Quebec
Canada HSR 3B6
Not with a bang, but
with sort of a swish,
the "packet" revolution
began. On May 31 ,1978, the
Montreal Amateur Radio
Club sent the first amateur
packets. The face and sound
of amateur radio will never
be the same again. Space-
age radio arrived for
amateurs. Our communica'
tions will be faster, more ac-
curate, more reliable, and
use less spectrum.
If you haven't heard of
packet radio, don't be sur-
prised. It is new. Don't look
MICRO
COiirROLLCD
TCnUfNAL
R£CElVEfl
THftNSMiT
5TiTg5
MOl>£H
in the Handbook or your
favorite ham magazine,
either. You'd have more
luck researching doctoral
theses for information.
Right now, there are about
two dozen packet systems
up and running in the
world. None of them are
amateur and none of them
contemplate the number
of users that an amateur
radio system would.
Packet radio is a name
given to the time-division
multiplexing of a radio
channel. Large numbers of
users can share one chan-
nel without QRM or has-
sles, Users don't even know
that they are sharing the
channel with anyone else.
The name "packet" is
w
RECEIVER
TRANSMIT ,
TRiVNSI^EiVER
Fig, 7, Block diagram showing component arrangement of
a typical packet radio station.
192
0
JLC
N^r
derived from the fact that
each message is sent in a
package. It has three parts:
the address and return ad-
dress called the "header/'
the data or message part
and the ''trailer/' which is
an error-detection scheme.
You can compare packet
radio to a sort of instant
electronic mail service.
Each packet is a postcard
You put your message on
the card, address it. and
put on the return address.
You then slip it in a mail
slot which is your amateur
radio station. If your mes-
sage is too long for one
postcard, then you'll just
send a series of them. Once
you slip it in the mail slot,
the system delivers the
card for you, or if it can't, it
returns the card automati-
cally.
How can so many users
share one channel? Speed.
Packets are sent from 25 to
25,000 times faster than
amateur RTTY Let's com-
pare packet RTTY to the
amateur kind. To send a
one-line message on 60
wpmTeletype^'^, yi j need
about 10 seconds, and no
one else can use the chan-
nel. The simple packet
system we'll see later only
takes 1/4 of a second to do
the same thing. The other
9-3/4 seconds could be
used for other messages,
up to 40 of them, in fact.
How does it go so fast?
There are two explana-
tions. First, instead of using
the channel while each let-
ter is sent, we wait until the
whole line is complete and
send it in a burst. Second,
the baud rate for our sys-
tem is 2000 instead of 45
for amateur Teletype. It
also fits in the same band-
width! This is not a con-
tradiction—we just use
better modulation schemes
which are capable of send-
ing more information in the
same bandwidth.
You are probably saying,
''Why all this packet non*
sense? It's just a faster
Teletype setup." Not at all !
You haven't heard the half
of it yet. The good part is
still to come. Packets are
drgitally encoded. This
means that anythrng that
can be "digitized" can be
sent in the packet: voice,
RTTY, slow-scan, televi-
sion, telemetry — you name
it Packet radio encom-
passes all modes! That's
why we call the "message"
part of the packet the data.
It coutd be any one of a
million things. But, that's
not all the good stuff.
Since packets are in a
digital format, they can be
read and understood by
simple computers. What if
we had a microprocessor
setup at a VHF repeater?
The repeater could read
the address on your packet
and, if it was out of town,
switch on a link transmitter
and relay it towards its
destination. Now if we had
microprocessor-controlled
repeater links all across the
country, your packet could
be delivered anywhere
within the range of a re-
peater Packets make this
kind of network easy. We
are now working on the
design of a packet net
called AMPAC (amateur
packet), which will make
this possible. Since packets
contain an error-detection
scheme at the end, check-
ing a message to verify that
it is intact is easy. If the
packet was damaged, we
could ask for a repeat
automatically if our ter-
minals were programmed
to do so.
Let's took at a few of the
applications for packet
radio. On the HF bands, I
bet the RTTY operators
would like to have a
system this fast which
automaticaHy calls for
repeats of packets dam-
aged by QRM and fading.
For once, the copy would
be clean all the way. The
same would be true for the
slow-scan TV crowd. The
image would form Irne-by-
line and with no snow!
Moonbouncers already use
a kind of burst technique.
Your terminal would be
programmed to send a
packet, and then wait a
predetermined length of
time for a return message.
If the return message
didn't come, the original
message would be repeat-
ed until it did. It could also
log the callsigns and time
that transmission was com-
pleted. Satellites are a
natural for packets. The
time-sharing aspect makes
the satellites available to
more people, and the com-
munications are more reli-
able The list is almost
endless, and that's what
makes packet so good.
If you've read this far,
you probably want to know
exactly how packet radio
works. First of all, you will
need a microprocessor-
controlled terminal, which
could be a TV typewriter
or Teletype machine for
hard copy. We'll look at a
packet Teletype system to
see how it works. You type
out your message and the
address of the receiving
station. The terminal will
fill in your call and address
as well as do the error-
detection calculations.
When this is complete, it
will be sent automatically.
At the other end, a terminal
will receive the packet and
took at the address. If the
packet is addressed to
someone else, the terminal
will dump it. Otherwise, it
will check for transmission
errors and, if the message is
intact, the terminal will
print it out or display it on
the screen. It wilt also send
an acknowledgement back
to you. If it didn't arrive in-
tact, it will send a negative
acknowledgement. Your
terminal, on seeing a nega-
tive acknowledgement, or
"NAK/' will retransmit the
packet again, and will do
so until it gets through or it
is instructed to give up.
What if two terminals
send at once? The packets
collide and are wiped out.
In this case, your terminal
won't get the acknowl-
edgement it is expecting,
so it sends the packet
again, and does so until it
gets the acknowledgement
it wants or is told to stop.
To prevent two terminals
from sending packet after
packet at the same time,
each terminal is instructed
by its microprocessor to
wait a random length of
time before sending the
packet again. The delay in
our case would be from 1
to 4 seconds. Since the
delay is random, and all
the terminals have this
routine built in, the
chances of a second or
third collision are very
small.
The rules that the ter-
minals follow are called
the protocol. This term will
be familiar to the com-
puter people. The protocol
makes every user feel as if
he is the only one on the
channel. You don't know
that it is being shared.
There is no QRM and no
hassles. The protocol,
which is written into the
program of the micro-
processor controlling your
terminal, can be as simple
or as complicated as you
wish. The fancy ones make
the system even more effi-
cient and maximize the
capacity of the channel,
but involve more memory
and software. The key is to
make sure that all users of
the local net play by the
same rules.
The hardware you'll
need is not fancy, A micro-
processor, a keyboard in-
put/output device, a radio,
and a modem are all that is
required. Our system runs
on 220-MHz FM and uses
the Western or Sangamo
Model 201 modem, running
at 2000 baud. We used this
one because it was
available surplus and was
cheap. We run 220 because
that's the only band in
Canada we are allowed to
use for packet right now.
The radio feeds the modem
which feeds the terminal.
The modem outputs phase-
shift keying using an
1800-Hertz tone so it can
go right in the microphone
jack. The output can come
from the speaker line or, if
you're fussy, right from
the discriminator to the
modem. The modem is
RS-232 standard, so hook-
ing it up to the computer is
no problem. See Fig. 1.
We have only touched
the surface of packet radio
and its applications.
Before you go any further,
however, you will have to
either move to Canada or
convince the FCC that
American amateurs should
be allowed to use packet
radio as well. As far as I
know, Canada is the only
country which is permit-
ting amateurs to experi-
ment With packet. I doubt
that it will stay this way for
very long. The prognosis is
for amateurs to develop
the first really large packet
network on VHF and UHF
which will be copied by
commercial operations
shortly afterward. Our
satellites will be the prov-
ing ground for more packet
techniques, and I bet com-
mercial stations will be
looking over our shoulders.
Again, amateurs are get-
ting into the act first. Who
else could supply millions
of free man-hours of
research and development
to the world? Right now
there are a few centers do-
ing research on packet
radio, Stanford Research
Institute is one, for in*
stance, and while they may
be better qualified than we
are, we sure outnumber
them!
Here, in Montreal, the
few of us who have formed
AMPAC will be pushing the
technique for all it's worth.
We are talking to AMSAT
to get permission to use
their satellites as well as
negotiating with our
government to get more
packet privileges. We
would be happy to talk to
anybody who is interested
in packet radio.
193
k/^
1
▲
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\r
KENWOOD
TR-7600 . .
The radio
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reinenribers
The all new Kenwood TR-7600 is packed with all the features
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for fast frequency change, ID watts RF output or 1 watt low
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RM-76 Microprocessor Control Unit provides more operating
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Price to be announced.
RM-76 Microprocessor
Unit optional
YAESU FT227RA
The "Memorizer"
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Provides 4 memofves, fmger touch
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channel merr^ofy tone burst
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429.00 Call fof quote today
YAESU CPU-2500RK
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This uHimate transceiver has
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Freq 144 to 148 MHz
585*00 Call for quote today
ICOM iC-280
Remotable 2-meter
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Freq. 143.90-148 11 mhz. power 10
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can detach and remotely mount the
main PLL control head, with micro-
processor, can store 3 freqs . and
has digital LEDs
453.00 Ca»! for yours today
Remember, you can Call Toll Free: 1'800-633-3410 m the US A or call 1-800-292-8668 in
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SWAN WM-3000
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87.95 CafI for yours today.
DRAKE WH-7
HF wattmeter
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Line imp. 50 ohms reststance,
89,00 Can for yours today
BIRD MODEL 43
Thruline^
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50 ohms nominal impedance
VSWR with UHF connectors 1 05
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1 25.00 Call for yours to<^3y
DENTRON
W-2 wattmeter
The W-2 fets you read forward and
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• Forward watt scale 2000 or 200
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Low insertion loss • Frequency
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SHURE 444
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The 4-BTV HF fixed sta-
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LM*MM-150K
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Tbe H wave length 2
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a3oe><^^
Dale Hikman WB6NTR
I J 32 Roseia Drive
Topanga CA 90290
This Voltage Standard Is Precise!
and makes calibration a snap
DO yoy sometimes wish
you had a stable
voltage source for call-
brating your DVM or the
vertical amplifier of your
dc scope, a source that
would remain rock stable
for months or years? Such
an instrument is usually ex-
pensive to build or buy
because it uses exotic com-
ponents such as standard
cells and perhaps -a; com-
plex voltage divider to pro-
vide various output poten-
tials. The voltage standard
described here may suit
your need perfectly, as it
provides an exceptipnaliy
stable output voltage using
ordinary off-the-shelf
parts, and an unconven-
tional "circular" voltage
divider, using the minimum
possible number of preci-
sion resistors, provides con-
venient switch-selected
output voltages.
The unit is powered by
two 9"Volt batteries, and
the output voltage is 0-10
volts in 10 millivolt steps,
although finer voltage divi-
sions may be obtained by
adding stages to the volt-
age divider, A microam-
meter is connected in
series with the output so
that the instrument may be
used to directly measure
dc voltage.
Output stability is about
±0.04% over a battery-
voltage range of 6-9 volts.
This tolerance can be re-
duced virtually to zero if
you elect to use a power
source better regulated
than batteries.
Thermal stability, over
the range of temperatures
II . I ■
less perfect, depending on
your choice of parts. Ad-
mittedly, the unit must be
calibrated against an accu-
rate voltage standard or
DVM but, once set, it will
remain stable more or less
indefinitely, depending
again on your choice of
parts. Accuracy of the
switch-selected output
voltages depends on the
tolerance of the resistors
you decide to use in the
voltage divider. We have
specified 0.1 % resistors, so
we get 0,1% accuracy. If
you use 0.01% resistors,
you will get 0.01% accu-
racy, but they will cost a
lot more. Output resis-
tance of the instrument is
several thousand Ohms,
but we will discuss means
to circumvent the effect of
loading on output voltage.
How It Works
Fig. 1 is a simplified
diagram of the voltage
standard, showing how the
use of a ''circular" voltage
divider minimizes the num-
ber of resistors needed to
obtain 1001 different out-
put voltages. This article,
as far as we know, is the
first published application
tional voltage divider, the
input voltage is applied
across the entire network,
and output is selected
from the constituent resis-
tors—but a disproportion^
ally large number of
resistors or a complex
switching schenae is
needed to get a large
number of output voltages.
In the circular voltage
divider, the output vo[tage
is taken from a fixed point,
and this potential is
selected by changing the
location to which the input
voltage is applied. This
scheme simplifies the re-
quisite switching and
minimizes the number of
resistors needed. In Fig. 1,
the digit beside each
resistor corresponds to the
voltage obtained when
that resistor is connected.
Output in this example
would be 6.43 volts.
The general rule apply-
ing to resistor values in the
circular divider is this: Ten
resistors are used in each
ring except the last, which
has eleven. The resistors in
each ring are 1.1 times the
value of the ones in the
preceding ring. Thus, if you
wanted an additional stage
to get steps of 1 millivolt,
you would substitute, for
the terminating resistor Rj,
another ring, containing 11
resistors of 1330 Ohms
each. How did we know
what value to start with in
the first ring? Well, if too
smalL the selected resistor
will unduly load the power
supply. But making it, and
all the other resistors,
larger will proportionally
increase the output resis-
tance of the divider.
If you want to build the
simplest possible divider,
you can omit the selector
switches and use alligator
clips where we have shown
arrows. To use the instru-
ment as a voltmeter, con-
nect the voltage to be mea-
sured at ''unknown E/' and
set the clips to obtain a
null on the meter. The un-
known voltage then corre-
sponds to the digits beside
the selected resistors.
Fig. 2 is a schematic of
the instrument, except for
the divider. The stable
voltage source consists of
field effect transistors
(FETs) Q1 and Q2, and
resistor R1. The FETs are
connected in series, form-
ing a very high impedance
current source which
develops the reference
voltage across R1 This
means of obtaining a
stable potential has not
been widely exploited and,
indeed, it is little known
even among FET manufac-
turers. The reference volt-
age, Er, depends on FET
Q2, ordinarily turning out
to be somewhere between
1 volt and 3.5 volts. You
don't have much control
over this parameter unless
you individually select the
2N3819 But Er is remark-
ably stable with changes in
battery voltage and can be
made almost completely
independent of tempera*
ture by the selection of R1,
as described later.
To get 10 volts for the
divider, Er is amplified by
op amp IC1, whose gain is
set by the selection of feed-
back resistor R3 and the
adjustment of CAL trimmer
R4. The S5556/MC1456 op
amp was chosen for its low
bias current (about 30
nanoamperes), its excellent
temperature stability, and
its reasonable price. To fur-
ther enhance temperature
stability, emitter-follower
Q3 obviates any loading on
IC1 and thereby keeps the
op amp cool. Capacitor CI
suppresses any tendency
to oscillate.
The divider uses three
two-pole, ID-position selec-
tor switches to perform the
function of the alligator
clips suggested for Fig. 1,
selecting 1000 different
output voltages (0-9.99
volts).
Referring again to Fig. 2,
setting switch 52 to S EL ap-
plies the selected voltage
to the output circuit. The
1001th voltage, 10 volts, is
obtained in the 10 V posi-
lOV
REGULATE!
R'lK fACH UI09
ft>l.{K EACH t« 10)
nazm EACH tilt »
NUU. mWCAWK
Fig. T. Simplified schematic of voltage standard. In the
"circular" voltage divider, the resistors in each ring are 1.1
times the value of the ones in the preceding ring. A
microammeter, used as a null indicator, provides a means
for directly measuring dc voltage.
tion. The potential se-
lected by 52 is applied to
output jack j1 through
microammeter Ml. The
time constant R5-C2 and
germanium diodes CR1
and CR2 protect the meter
movement from slamming
when Jl is connected to a
voltage much different
from the one selected.
Resistor R6, in turn, pro-
tects the diodes from burn-
out when the selected
voltage happens to be 0
volts. In this case the
divider output is at com-
mon and, without R6. any
voltage on Jl would be ap-
plied directly across one of
the diodes.
Output resistance of the
divider is about 1000
Ohms, The output resis-
tance of the unit is,
therefore, this value in
series with R5, R6, and the
microammeter, for a grand
total of 2000 to 5000
Ohms, depending on the
meter resistance. There-
fore, the instrument cannot
be loaded without loss of
accuracy. Even a 1 -meg-
ohm load could drop the
output voltage as much as
0.5%. We will deal with
this problem under
"Operation/' On the other
hand, if you can tolerate a
higher output resistance,
you would be well advised
to make all the resistors in
the divider much larger in
value. They should all be
increased by the same fac-
tor, say by 10 or even 100
times. This would make the
current in the first divider
ring proportionally lower,
R4
DIVtOCR
10V
! jmt^t
Jl
OHOV
OUtPklT
MARY
fOiJTPUT
G)
Fig. 2. Schematic of precision voltage source and output
circuit of instrument. Inexpensive 2N3819 FETs provide an
extremely stable reference voltage, amplified to 10 V by
IC1 and Q3. Output voltage is applied to 11. Microam-
meter nail indicator is protected from siamming by RC cir-
cuit and diodes.
201
tnterior view of instrument AH parts are mounted on back
of the front panei The divider resistors are located on a
perfboard mounted on the meter terminals. The precision
voltage source subassembly is built on another perfboard
mounted to the first
alleviating problems of
stray voltage drops and
greatly increasing battery
life. However, it would also
reduce meter deflection,
so you might have to
employ a more sensitive
movement.
If you wish to bypass the
various resistances of the
output circuit, you can add
the auxiliary output jack
0
0£3T v*lUE roH nr
I5K
Fig. 3. Graph of R1 vs. £/? when /?7 is 4700 Ohms approx-
imates optimum value for new R1. Exact value for best
temperature stability can be determined by heat test (See
text "Adjustment")
shown in dashed lines. This
addition also provides ac-
cess, when S2 is in the 10 V
position, directly to the
10-vott source, whose
resistance is practically
zero 4nd which can, there-
fore, be loaded heavily
with virtually no loss of
voltage*
Choice of Paris
Temperature stability
depends on your choice of
RVR4. For best results,
precision resistors should
be used for R1-R3, not
because these resistances
are critical, but because
precision types are less af-
fected by time and temper-
ature than composition.
Film or wirewound units
are a good choice.
However, the values of R1
and R3 will be selected as
described under "Adjust-
ment/' the former for best
temperature indepen-
dence and the latter to set
the output voltage. For this
selection process, you can
use ordinary composition
resistors, and later replace
them with the precision
variety. For best stability
and ease of adjustment, R4
should be a multi-turn trim-
mer, either wirewound or
cermet. A shaft lock is
desirable. Precision re-
sistors must be used in the
divider and, as we have
indicated earlier, a closer
tolerance than we have
specified will provide more
accurate output voltages.
Any general purpose, sili-
con NPN transistor may be
substituted for the 2N697
specified at Q3.
If you have a mathe-
matical bent and wish to
interpolate the meter
reading to estimate poten-
tials falling between the
positions of "hundredths"
switch S30, you may wish
to use a more sensitive
meter (say, 10-0-10 micro-
amperes). In this case,
CR1 and CR2 will intro-
duce a troublesome non-
linearity, so you may
wish to use silicon diodes
or back-to-back zeners for
a higher threshold voltage.
If you want the meter to
respond faster, you can use
a smaller value for C2.
Either change, though, will
cause the meter to slam
harder.
Any hookup wire used in
the divider section of the
instrument must be no
smaller than No. 22.
Smaller wire would devel-
op voltage drops that
degrade accuracy. If you
have decided to add a
fourth or fifth stage to the
divider, you should care-
fully consider the effect of
contact resistance in the
voltage selector switches.
It might be necessary to
procure special switches
made for this sort of ap*
plication.
Construction
The voltage standard
can be built in any conve-
nient enclosure. As shown
in the photos, all parts in
the author's prototype, in-
cluding the batteries, were
mounted on the backside
of the front panel of an in-
strument housing, The
divider resistors are lo-
cated on a perfboard
mounted to the meter ter-
minals. You can, instead,
mount the resistors direct-
ly on the switch terminals,
but this will much com*
plicate matters if you have
to correct wiring errors or
later decide to change the
divider resistors for ones
having different values or
tolerances. The precision
voltage source is con-
structed on a smaller perf-
board mounted to the first
by spacers.
Do not use the chassis as
the common conductor. In-
stead, use wire leads be-
tween components. The
common conductor may
then be connected to the
chassis, but at one point
only. If the connector you
plan to use at Jl is some-
what difficult to insulate,
as many jacks are, you may
make the chassis connec-
tion at this point, as shown
by the dashed symbol in
202
Fig. 2, This connection,
however, creates an
obscure but potent hazard.
Due to manufacturing
defects, an occasional
9-volt battery has an inter-
nal short circurt between
one terminal and the case.
!f the battery case is
touching the chassis and
the common conductor is
also connected to the
chassis, the battery will be
shorted and may explode!
Therefore, as in any equip*
ment using 9-volt batteries
where the case is ground-
ed, it is smart to insulate
the battery holders from
the case. Solder carefully.
Rosin joints introduce
stray voltage drops.
As we mentioned earlier,
the values of resistors Rl
and R3 will be individually
selected. For now, how*
ever, temporarily install
4700 Ohms at Rl and
18,000 Ohms at R3.
Adjustment
The adjustment pro-
cedure has two main parts.
First, Rl must be selected
for best temperature
stability, and then R3 must
be selected to yield 10
volts from the dc amplifier.
To select Rl, proceed as
follows:
l.Set SI to ON.
2. Measure voltage Er
across 4700-Ohm resistor
Rl.
3. Find the best value for
the new Rl from Fig. 3,
and replace Rl with this
value,
4. If you are using a DVM
of at least 4 Vi digits, you
can now verify temper-
ature stability by
touching the tip of a hot
soldering iron to Q2 for
about 3 seconds Refer-
ence voltage Ef^ should
not vary more than a few
millivolts, [f it does, cor-
rect the value of Rl as
needed.
To select R3, you need
only a reasonably accurate
voltmeter such as a typical
VOM. Then, to trim R4 to
exactly 10 volts, you will
need either an accurate
DVM [preferably 4 V2 digits
or more), or a precision
voltage source such as a
standard battery, having a
known terminal potential
up to 10 volts. If you don't
need perfect calibration,
however, instead of a stan*
dard battery you can use a
brand new Mallory Dura-
cell Type MN-1604, which
has an open-circuit poten-
tial close to 9.32 volts. Do
not use as a standard
either of the batteries
powering the instrument
because its load drops the
voltage too much. To
select R3, proceed as
follows:
1 . Set CAL trimmer R4'to its
mid-position,
2. Set S2 tolO V,
3. Connect the voltmeter
between common and
the arm of S2, or to the
auxiliary output jack if
you have one.
4. Select R3 to get a
reading as close to 10
volts as possible.
5- If using a DVM, adjust
R4 to get 10.000 volts.
This step ends your ad-
justment procedure.
Otherwise, proceed to
step 6.
6. Set S2 to SEL.
7. Set the selector switches
to correspond to the
voltage of the standard
battery,
8. Connect the standard
battery to |1, plus to the
meter side, minus to
common.
9. Adjust R4 to zero the
meter.
Operation
The voltage standard
has two main uses, as a
0-10- volt dc voltmeter or as
a precision voltage source.
To use the instrument as a
dc voltmeter, proceed as
follows:
1. Set SI to ON.
Z Set S2 to SEL.
3. Set voltage selector
switches S10, S20, and
S30 to approximate the
voltage you wish to
measure. If you can't
estimate this unknown
; 3:i3V
fig, 4. Two methods to avert the effect of loading on out-
put voltage.
voltage, set the switches
to 5.55 volts.
4, Connect the unknown
voltage to |1, plus to the
meter side and minus to
common.
5. Set voltage selector
switches S10, S20, and
S30 to zero the meter as
nearly as possible. The
switch settings now cor*
respond to the unknown
potential. (If the un-
known turns out to be
exactly 10 volts, the
meter will of course
zero with S2 set at 1 0 V J
If the meter needle is
not exactly at zero, then
the unknown is a few
millivolts different from
the setting of "Hun-
dredths" switch S30.
You might try inter-
polating to estimate the
difference, but if you
have used 0.1%
resistors in the divider.
Parts List
{for divider of Fig, 1)
R10-R19 1,000'Ohm. 0.1%, y*-Watt precision resistor
R20'R29 1100-Ohm, 0.1%, y4-Watt precision resistor
R30'R40 laiD-Ohm, 0J%, %-Watt precisron resistor
S10, S20, &
S30 2-pole. imposition rotary swftch
Note: 0.1 % resistors described above are available at $1 €ach from
Gal-State Electronics, 5222 Venice 8L, Los Angeles CA 90019. Add
$1,50 for shipping (UPS). California residents please add 6% sales
lax.
B1, B2
CI
02
CR1,CR2
IC1
J1
Ml
Q1,Q2
Q3
Rl
R2
R3
R4
R5
R6
SI
82
Misc.
Parts List
(for electron tcs of Fig. 2)
9-volt battery
0.01 uF capacitor
2000 uF, 3-vQlt electrolytic capacitor
IN 100 germaniunrt diode
S5556/MC1456 op amp (preferably by Signetics)
phono receptacle or other suitable 2-conductor
jack
50-0-50 dc microam meter
2N3S19 field effect transistor (Texas Instruments)
2N697 transistor
1%, V4-Watt precision resistor; value selected. See
text, "Choice of parts/' Temporarily use 4700-Ohm
composition-type.
10,000 Ohm, 1%, y^-Watt precision resistor
1%, V4-Watt precfslon resistor^ value selected. See
text. '^Choice of parts." Temporarily use 18,000-
Ohm composition-type.
5N panei-mounting trimmer potentiometer
100-Obm, 10%, V4 -Watt resistor
330'Ohm, 10%,V4*W3tt resistor
SPST toggle switch
SPDT toggle switch
22-gauge hookup wire for divider, perfboard, push-
in terminals, IC socket, battery clips, battery
holders, cabinet, etc. To select Rl and R3, a suppEy
of 5% composition resistors, or a resistor-
substrtution ("decade") box in the range of 1000
Ohms to 100,000 Ohms Is required. See separate
parts list for divider.
203
remember that your
reading will only be ac-
curate within 0.1 per-
cent of the indicated
voltage anyhow.
As a voltage source, a
typical use of the instru-
ment is in the calibration of
a voltmeter- It is especially
valuable, for example, to
check the linearity of a
DVM, However, the volt-
age source application
may involve loading com-
plications. The input
resistance of a typical
DVM is 100 or 1000 meg-
ohms, so it should give you
no such problem. Given a
load of lower resistance,
though, say a 20,000-Ohms-
per^volt VOM, you must
either mathematically
allow for the load or avert
its effect entirely. In the
former course, you are on
your own, but with the lat-
ter, we can offer a couple
of methods: As shown in
Fig. 4, you can either
decouple the voltage stan-
dard output through an op
amp voltage follower, or
create a bridge with the use
of a pot.
In the method of Fig.
4(a), an op amp is con-
nected as a voltage
follower to relieve the load
on the voltage standard
output. For best accuracy,
you should choose an op
amp that has provisions for
nulling its offset and which
is rated for low offset-
current.
The method of Fig. 4(b) is
simpler and cheaper
though not as convenient.
In this method, the voltage
standard is one leg of a
bridge, the other being pro-
vided by a potentiometer
that matches the voltage
set by the standard, With
this scheme, once having
set the voltage selector
switches to the potential
you want, simply adjust
the pot to zero the meter.
For smoothest adjustment,
the resistance value of the
pot should be one half to
one tenth Rl. ■
frompagt 158
ab(e K-2 frequency-determining
elements, avaitabte in aff El A
tone frequencies from 268.5 Hz
to 2109.0 Hz.
Power requirements are 6 to
16 V dc unregulated al 10 mA.
Reverse polarity and over-
voltage protection are buUt^n.
AH connections to the board
are made with push-on connec-
tors, and color^coded wires are
furnished.
The SD-1 may be driven by
the discriminator, by the audio
stages, or from the speaker cir-
cuit. Sv^fltched outputs Include
momentary high current clo-
sure to ground for horn relay, a
latched high current closure for
a call light, and a latched low
current, high voltage pull-away
from ground to unmute the
receiver.
The unit is completely Im-
mune to rf and comes complete
with universal mounting hard-
ware, A full one year warranty
applies when the unit is re-
turned to the factory for repair.
For further information, con-
tact: Communications Speciat-
ists, 426 West Taft Avenue,
Orange CA 92667: (714}-998-
3027, (800^854^0547. Reader
Service number 06.
YAESU'S FT 225RD 2M
TRANSCEIVER
A new state-of-the-art 2
meter all-mode transceiver, the
FT-225RD, has been added to
Yaesu's quality line of amateur
radio equipment.
The new transceiver covers
the entire 4 MHz and provides
for USB, LSB, CW, FM, and AM.
Power output is variable, 1-25
Watts. Squelch, VOX, PTT,
semi-break-in CW with side-
tone, and tone burst are stan-
dard features of the FT-225RD.
A superb noise blanker permits
mobile SSB operation, and a
discriminator center meter
allows precise zeroing on FM
signals. Repeater splits are the
standard 6O0 kHz; however, any
split up to 1 MHz is possible
with optionat crystals. Provi*
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eleven (11) fixed channels us-
ing optional crystals.
The transceiver utilizes high
quality plug-in circuit boards
throughout, and an optional
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storage and recall of any fre-
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unit. This aMows Instant pro-
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The digital frequency is ac<
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A built-in power supply pro-
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110/117/200/220 and 234 volts
50/60 Hz. Dc operation covers
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only 9.0 kg.
An attractive four-color
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po fat ion, 15954 Downey Ave-
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CA 90723. Reader Service
number Y1,
ECONOMY HAND TOOL
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For more Information, con-
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Service number A70. SUPER
Continued on page 253
The FT-225RD 2m transcetver from Yaesu.
AMP Special tnduBtnes' new SUPER CHAMP hand tool
204
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y^ Header Service see fxage 323.
205
The 22S Goes Digital
— add 7-segment displays
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(FROM SWITCH]
ON ICZas
BQ3 K
5V HE(i
VCC FDR
BCD TO
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■^- J OECODERS
AND
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303 K
5V REG
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F/g. 7. IC-22S frequency display schematic diagram.
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I
Raymond E. Thompson KH6IEL
2040 Komo Mai Drive
Peari City HI 96782
Although very popular
since its introduction
by Icom, one big problem
with the IC-22S is that it is
so darn hard not to add
nnodiffcations. Funny, but
with a crystal-controlled 2
meter transceiver, the
thought of adding addi-
tional channels seldom
enters your mind. Six, fif-
teen, or twenty-four chan-
nels or whatever was
originally supplied seems
adequate. When you own
an IC-22S, you can program
any frequency you like
with diodes. Frequency
selection with only one
knob is a great feature
which really adds a lot to
operating convenience.
That's where the problem
comes in. The 23 channels
that you can select don't
seem to be enough. Some-
thing keeps you trying to
think of different methods
of getting more channels.
Several easy ones come to
mind right away: adding an
eight-level DIP switch,
using toggle switches to
add 15, 30, or 45 kHz to the
programmed frequency, or
adding a second matrix
board and using the
previous high/low power
switch as a selector. All of
these have one common
drawback: You have to
memorize switch settings
or use charts, tables, etc.,
to know what frequency
you are operating on. Even
the mode switch can cause
206
problems if you forget that
some of your programmed
channels are simplex
rather than repeaters.
What is needed is a direct
frequency readout.
That is the subject of this
article. A direct frequency
display for the IG22S, It
works on receive or trans-
mit and converts whatever
binary code you have at
the divider input in the
IC-22S to a direct-reading
frequency.
Programming the diode
matrix board for a par-
ticular frequency has been
covered in several articles
and in the operating man-
ual, so I won't go into any
of that. The circuit for the
frequency readout can be
broken down into two
functions. First, we must
convert the eight-level
binary code in the IC"22S
The clock case used to enclose the display fits very nicety on top of the IC-ZZS. No ques-
tion as to what frequency channel 5 is on this IC-22S.
AODRtSS SWITCHES
fteAD^^HOQflfM SWITCHES
Fig, Z Manual programmer from Signetics for 82S129 PROM.
207
divider into the appro-
priate BCD code for fre-
quency, Second, we have
to convert the BCD code to
a visual display of frequen-
cy. ''Why two steps and not
just one?" you might be
asking. It's simpler using
two steps. We have eight
inputs to convert to
twenty-two outputs. Two
for the MHz: (6 and 7) and
ten for both the 100
kHz and 10 kHz positions
(1-10). If we use seven-
segment LEDs, this cuts our
requirements down to fif-
teen. Eight inputs must be
converted to fifteen out-
puts. No such device is
available.
Instead of looking at all
three displays together,
and by looking at each one
separately, we come up
with eight inputs and seven
outputs for the 10 and 100
kHz digits. This is still a
pretty expensive thing and
beyond using simple gate
logic. If we use a standard
BCD-to-seven-segment de-
coder ahead of each dis-
play, we have cut our re-
quirements to eight inputs
with four outputs. Now we
are getting somewhere!
Any 256 x 4-bit converter
would work, one for each
display digit. That's it. Tie
three 256 x 4-bit PROMs,
with their inputs in
parallel, to standard
decoders to drive the
display digits!
Looking at the sche-
matic diagram [Fig. 1), IC1
and IC2 are simply hex buf^
f er converters. They get the
CMOS binary divider out-
puts down to TIL where we
can use them. Since only
eight are needed, there are
four unused buffers which
could be used for some
other purpose. I used the
82S129 PROM for two rea-
sons. A 256 X 4-bit device
was required and the
82S129 PROM cost was
only $2.50 from S.D. Sales.
The PROM for the MHz
position (IC3) has to be pro-
grammed to produce a 5, 6,
7, or 8 with the appropriate
binary input. Likewise, IC4
must be programmed to
output the proper BCD
code in the 100 kHz posi-
tion of the frequency
readout, IC5 is for the 10
kHz numbers.
Let's look at 146,520
MHz to see how this works
out- 146.520 has the binary
address of 142. This is
found in the owner's man-
ual or can be calculated by
several means. So, we need
the binary address code of
142 to be changed to a
BCD code representing
146520. The hundreds and
tens of MHz (1 and 4) will
never change, so they can
be either hardwired in the
display or forgotten about,
IC3 (MHz) is programmed
Program chart. 145350-148.035
Address
ica
iC4
IC5
13Q
«4
^i
1«
4
4
2
1
« 4 2 1
a 4 2 t
6 4 2 1
064
0
0
0
0
0
0
0
0101
0011
0101
065
0
0
0
0
0
0
1
0101
0011
0110
066
0
0
0
0
0
1
0
0101
0011
1000
067
0
0
0
0
0
1
1
0101
0011
1001
068
0
0
0
0
1
0
0
0101
0100
0001
069
0
0
0
0
1
0
1
0101
0100
0010
070
0
0
0
0
1
1
0
0101
0100
0100
071
0
0
0
Q
1
1
1
0101
0100
0101
072
0
0
0
0
0
0
0101
0100
0111
073
0
0
0
0
0
1
0101
010O
1000
074
0
0
0
0
1
0
0101
0101
0000
075
0
0
0
0
1
1
0101
0101
0001
076
0
0
0
1
0
0
0101
0101
0011
077
0
0
0
1
0
1
0101
0101
0100
078
0
0
0
1
1
0
0101
0101
0110
079
0
0
0
1
1
1
0101
0101
0111
080
0
0
0
0
0
0
0101
0101
1001
081
0
0
0
0
0
1
0101
01 to
0000
082
0
0
0
0
1
0
0101
0110
0010
083
0
0
0
0
1
1
0101
0110
0011
084
0
0
0
1
0
0
0101
0110
0101
085
0
0
0
1
0
1
0101
0110
0110
086
0
0
0
1
1
0
0101
0110
1000
087
0
0
0
1
1
1
0101
0110
1001
088
0
0
0
0
0
0101
0111
0001
089
0
0
0
0
1
0101
0111
0010
090
0
0
0
1
0
0101
0111
0100
091
0
0
0
1
1
0101
0111
0101
092
0
0
1
0
0
0101
0111
0111
093
0
0
1
0
1
0101
0111
1000
094
0
0
1
1
0
0101
1000
0000
095
0
0
1
1
1
0101
1000
0000
096
0
0
0
0
0
0
0101
1000
0011
097
0
0
0
0
0
1
0101
1000
0100
098
0
0
0
0
1
0
0101
1000
0110
099
0
0
0
0
1
1
0101
1000
0111
100
0
0
0
1
0
0
0101
1000
1001
101
0
0
0
1
0
1
0101
1001
0000
102
0
0
0
1
1
0
0101
1001
0010
103
0
0
0
1
1
1
0101
1001
0011
104
0
0
1
0
0
0
0101
1001
0101
105
0
0
1
0
0
1
0101
1001
0110
106
0
0
1
0
1
0
0101
1001
1000
107
0
0
0
1
0101
1001
1001
108
0
0
1
0
0
0110
0000
0001
109
0
0
1
0
0110
0000
0010
110
0
0
1
0
0110
0000
0100
111
0
0
1
0110
0000
0101
112
0
0
0
0
0
0110
0000
0111
113
0
0
0
0
0110
0000
1000
114
0
0
0
0
0110
0001
0000
115
0
0
0
0110
0001
0001
116
0
0
1
0
0
0110
0001
0011
117
0
0
1
0
0110
0001
0100
118
0
0
1
0
0110
0001
0110
119
0
0
1
0110
0001
0111
120
0
0
0
0
0110
0001
1001
121
0
0
0
0110
0010
0000
122
0
0
0
0110
0010
0010
123
0
0
0110
0010
0011
124
0
1
0
0
0110
0010
0101
125
0
1
0
0110
0010
0110
126
0
1
0
0110
0010
1000
127
0
1
0110
0010
1001
128
0
0
0
0
0
0
0
0110
0011
0001
129
0
0
0
0
0
0
0110
0011
0010
130
0
0
0
0
0
0
0110
0011
0100
131
0
0
0
0
0
0110
0011
0101
132
0
0
0
0
1
0
0
0110
0011
0111
133
0
0
0
0
1
0
0110
0011
1000
134
0
0
0
0
1
0
0110
0100
0000
135
0
0
0
0
1
0110
0100
0001
136
0
0
0
0
0
0
0110
0100
0011
137
0
0
0
0
0
0110
0100
0100
138
0
0
0
0
0
0110
0100
0110
139
0
0
0
0
0110
0100
0111
140
0
0
0
1
0
0
0110
0100
1001
141
0
0
0
1
0
0110
0101
0000
142
0
0
0
1
0
0110
0101
0010
143
0
0
0
1
0110
0101
0011
144
0
0
0
0
0
0
0110
0101
0101
145
0
0
0
0
0
0110
0101
0110
146
0
0
0
0
0
0110
0101
1000
147
0
0
0
0
0110
0101
1001
148
0
0
0
1
0
0
0110
0110
0001
149
0
0
0
1
0
0110
0110
0011
150
0
0
0
1
0
0110
0110
0100
161
0
0
0
1
0110
0110
0101
203
for a BCD 6 (0110). 1C4
(kHz) at address 142 is pro-
grammed for an output
BCD 5 (0101). Likewise IC5
(10 kHz) at address 142 is
programmed to a BCD 2
(0010). The kHz position
does not require a PROM
for conversion because
anytime DO is low, we
want a 0, and when it's
hfgh, we want a 5. In this
case, the binary number is
142 (10001110), so we read
a 0 DO is the last digit of
the binary or the least
significant. For address
142, we'll have IC3 = 6,
IC4 = 5, IC5 = 2. and DO
= 0, As another example,
take a look at 146 010
MHz. The binary address
for this frequency is 108 or
01101100. Here we'll want
IC3 = 0110, IC4 = 0000,
IC5 = 0001, and DO = 0.
The second function is
changing the BCD outputs
to a display reading. I just
happened to have a six-
digit display that I had
been wanting to use, so I
used 7445 BCD-to-decimal
decoders. LEDs and ap-
propriate decoders would
work nicely and would
probably be the logical
choice if you didn't already
have some other type of
readout display.
Programming the PROMs
was my first experience
with PROMs. Until this
time, I just didn't have a
need to get into this. I was
a little leery about at-
tempting it, but I soon
found out that it wasn't
that hard. I did follow the
manufacturer's circuit
recommendations and the
PROMs were programmed
without difficulty. I built
the required programmer cir-
cuit into my Heathkit® IC
Tester, since the IC socket
and all the switches were
already there. I had to
modify my IC Tester in
order to do this; however, t
won't go into any details of
the modification. I will just
include the circuit recom*
mendations from the chip
manufacturer. I will have
to agree with others that
patience and care are the
main things you must have
when you are manually
programming a PROM. The
manufacturer also in-
cluded waveforms to be
used with automatic pro-
gramming.
The programmer circuit
[Fig. 2) appears at first to be
a little involved, but is
really pretty straightfor-
ward. The complete cycle
takes 5 milliseconds and is
controlled by one-shot 1,
Its resting state causes the
case of the 5-volt regulator
to be grounded through Vi
of the 75451, which puts
Vcc for the PROM at 5
volts. With the address
switches set to the desired
152 1
1 0
0
0
0
0
0110
0110
0111
153 1
1 0
0
0
0
1
0110
0110
1000
154 1
1 0
0
0
0
0110
0111
0000
155 1
1 0
0
0
1
0110
0111
0001
156 1
1 0
0
1
0
0
0110
0111
0011
157 1
1 0
0
1
0
1
0110
0111
0100
158 1
1 0
0
1
0
0110
0111
Olio
159 1
f 0
0
1
1
0110
0111
0111
160 1
1 0
0
0
0
0
0
0110
0111
1001
161 1
f 0
0
0
0
0
1
0110
1000
0000
162 1
1 0
0
0
0
0
0110
1000
0010
163 1
1 0
0
0
0
1
0110
1000
0011
164 1
1 0
0
0
1
0
0
0110
1000
0101
165 1
1 0
0
0
1
0
1
0110
1000
Olio
166 1
1 0
0
0
1
0
0110
1000
1000
167 1
1 0
D
0
1
1
0110
1000
1001
168
1 0
0
0
0
0
0110
0110
0001
169
1 0
0
0
0
1
0110
1001
0010
170 '
1 0
0
0
0
0110
1001
0100
171
1 0
0
0
1
0110
1001
0101
172
I 0
0
1
0
0
0110
1001
0111
173
1 0
0
1
0
1
0110
1001
1000
174 1
1 0
0
1
0
0111
0000
oooo
176
1 0
0
1
1
0111
0110
0001
176 '
I 0
0
0
0
0
0111
0110
0011
177
1 0
0
0
0
1
0111
0110
0100
178 '
1 0
0
0
0
0111
0111
0110
179 1
1 0
0
0
1
0111
0111
0111
180
1 0
0
1
0
0
0111
0111
1001
181 1
1 0
0
1
0
1
0111
0111
oooo
182 1
1 0
0
1
0
0111
0111
0010
183 1
1 0
0
1
1
0111
0111
0011
184 1
r 0
0
0
0
0111
1000
0101
185
1 0
0
0
1
0111
0001
Olio
186 1
1 0
0
0
0111
0001
1000
187 1
1 0
0
1
0111
0001
1001
188 '
1 0
1
0
0
0111
0010
0001
189
1 0
1
1
0111
0010
0010
190
1 0
1
0
0111
0010
0100
191 1
1 0
1
1
0111
0010
0101
192
0
0
0
0
0
0
0111
0010
0111
193
0
0
0
0
0
1
0111
0010
1000
194
0
0
0
0
0
0111
0011
oooo
19S
0
0
0
0
1
0111
0011
0001
196
0
0
0
1
0
0
0111
0011
0011
197
0
0
0
1
0
1
0111
0011
0100
198 1
1 0
0
0
1
1
0
0111
0011
0110
199 1
1 0
0
0
1
1
1
0111
0011
0111
200 1
1 0
0
0
0
0
0111
0011
1001
201 1
1 0
0
0
0
1
0111
0100
oooo
202 1
1 0
0
0
1
0
0111
0100
0010
203 1
1 0
0
0
1
1
0111
0100
0011
204 1
1 0
0
1
0
0
0111
0101
0101
205 1
1 0
0
1
0
1
0111
0100
0110
206 1
1 0
0
1
1
0
0111
0100
1000
207 1
1 0
0
1
1
1
0111
0100
1001
208 1
1 0
0
0
0
0
0111
0101
0001
209 1
1 0
0
0
0
1
0111
0101
0010
210 1
1 0
0
0
1
0
0111
0101
0100
21 1 1
1 0
0
0
1
1
0111
0101
0101
212 1
1 0
0
1
0
0
0111
0101
0111
213 1
1 0
0
1
0
1
0111
0101
1000
214 1
1 0
0
1
1
0
0111
0110
oooo
215 1
1 0
0
1
1
1
0111
0110
0001
216 1
1 0
0
0
0
0111
0110
0011
217 1
1 0
0
0
1
0111
0110
0100
218 1
1 0
0
1
0
0111
0110
0110
219 1
1 0
0
1
1
0111
0110
0111
220 1
1 0
1
0
0
0111
0110
1001
221 1
1 0
1
0
1
0111
0111
oooo
222 1
1 0
1
1
0
0111
0111
0010
223 1
1 0
1
1
1
0111
0111
0011
224 1
1 1
0
0
0
0
0
0111
0111
0101
225 1
1 1
0
0
0
0
1
0111
0111
Olio
226 1
1 1
0
0
0
1
0
0111
0111
1000
227 1
1 1
0
0
0
1
1
0111
0111
1001
228 1
1 1
0
0
1
0
0
0111
1000
0001
229 1
1 1
0
0
1
0
1
0111
1000
0010
230 1
1 1
0
0
1
1
0
0111
1000
0100
231 1
1 1
0
0
1
1
1
0111
1000
0101
232 1
1 1
0
0
0
0
0111
1000
0111
233 1
1 1
0
0
0
1
0111
1000
1000
234 1
1 1
0
0
1
0
0111
1001
oooo
235 1
1 1
0
0
1
1
0111
1001
0001
236 1
1 1
0
1
0
0
0111
1001
0011
237 1
1 1
0
1
0
1
0111
1001
0100
236 1
1 1
0
1
1
0
0111
1001
0110
239 1
1 1
0
1
1
1
0111
1001
0111
240 1
1 1
1
0
0
0
0
0111
1001
1001
241 1
1 1
1
0
0
0
1
1000
oooo
oooo
242 1
1 1
1
0
0
1
0
1000
oooo
0010
243 1
1 1
1
0
0
1
1
1000
oooo
0011
2m
The three PROMs m the lower ieti leave plenty of room for
the four decoders and display lamps. This clock case
would be almost empty if LEDs had been used.
address, flipping any one
of the output switches
starts the 5 ms cycle. The
case of the regulator is
ungrounded, which raises
Vcc up to 8J5 votts and
starts one-shot 2 for a 2 ms
delay. Following the delay,
one-shot 3 is turned on for
3 ms. This removes the
ground from the regulator
and selected output pin,
which lets this go to 17
volts, it also starts delay
one-shot 4 which operates
one-shot 5 after 1 ms delay.
One-shot 5 raises the chip
enable pin for 1.5 ms. The
waveforms are indicated
on the diagram The output
switch is returned to the
read position and another
output to be programmed
to a one at this address will
run the cycle again.
I started my program-
ming with IC3. To get
started and check my pro^
cedures, I put in address 1
(00000001) With ail output
switches in the read posi-
tion, the LEDs remained
off. indicating a 0000 in the
output. I toggled the
switch for output 1 [pin 12).
The circuit ran through its
operation and was now
reading a 1 . Leaving the ad-
dress switches at 00000001 ,
I flipped each of the other
ICI and IC2 are shown mounted on the shield using a
stand-off. The added accessory connector on the left
leaves plenty of spare connectors for other goodies.
output switches and. sure
enough, they now read
1111. (With this circuit, just
toggling the desired output
switch from read to pro-
gram and back again is all
that is required to program
a 1 into the output. Noth-
ing could be easier,) I had
just programmed a BCD 1 5
into address 1. This didn't
matter because the first ad-
dress that I was going to
need was 108. So with 108
as the address [01101100L
all I had to do was program
a BCD number 6 (0110). I
programmed these outputs
(pins 11 and 10) to ones
When I switched to anoth-
er address, my outputs
went to 0000 Returning to
108, I had my BCD 6, big as
life. I then went down
through the remaining ad-
dresses, programming the
appropriate BCD 6 or 7. In
fact, I decided to program
the appropriate BCD num-
ber all the way from 64
through 243, just because
my IC-22S would operate
in this range.
IC4 and tC5 were not as
straightforward because
they have a lot of changes
in their outputs. To keep
f^om getting confused, I
made up a chart which
gave me the outputs for
each PROM. Numbering
from 64 through 243, I put
down the eight-bit binary
address and then the ap*
propriate BCD number for
each PROM. Before chang-
ing to the next address, I
checked the chart against
my LEDs to make certain
that I had the right BCD
number programmed.
Making the output a 1 is
easy, but once you toggle
the switch, it's a 1, and if
you toggle the wrong
switch at that address, you
are in trouble.
One suggestion I have is
to mark each PROM with
some kind of identification
after being programmed.
They all look aHke and are
much easier to visually
identify than to look up the
output codes in your pro-
grammer to tell the dif-
ference, once they are pro-
grammed. 1 marked mine
by the number of kHz.
I placed the PROMs, de-
coders, and displays all
together in a small clock
cabinet. This kept my inter-
face cable down to 11
wires, I used perf board
and point-to-point wiring.
ICI and 1C2 are mounted
close to the divider and
add circuit. I used ribbon
cable from the converter
outputs to the accessory
jack. If power is connected
through the two spare pins
of the power cable, the
original 9-pin socket is ade-
quate. Removing the orig-
inal 9'pin socket and
replacing it with a 24-pin
connector would be a iot
better. Once you use all 9
pins for a frequency dis-
play, you will certainly
need more pins to add
channels, or a scanner, or
an external meter, or some-
thing. I couldn't find a
24-pin connector locally,
so I enlarged the opening
and put in a 36-pin
Waldom connector.
When soldering connec-
tions to the pins of the
divider, use care. The in*
puts for the converters
could be taken from the
matrix board [DO through
D7) rather than the divider
(DO through P7) which
would be easier to get to. If
this is done, in order to
make the frequency read
correctly, two CD4008 full-
adders would have to be
placed ahead of the
PROMs and operated with
the DP line. I gained access
to the divider inputs (DO
through P7) by removing
the matrix board, removing
the 3 mounting screws and
one threaded stand-off,
and turning the board up
so I could get to the pins of
the ICI divider The wires
were soldered onto pins 1
through 8 of ICI and run
toward the rear of the
transceiver. These wires
run under the board out to
the perfboard for ICI and
IC2. I put my outputs of the
converters on one side of
210
the perfboard and the in-
puts on the other side,
which helped in keep-
ing the installation neat,
My display lamps and
drivers draw a little over
600 mA, so I used two
separate 5-volt regulators.
I mounted these on a metal
plate with heat sinks. The
plate is mounted to the
back of the IC-22S with
stand-offs. The logic
doesn't draw much current
so, depending on the dis*
play requirements, one
regulator might do the job.
The display can be
mounted on top of the
IC-22S or any easily
readable position.
Since the binary code
present at the divider is
always present and con-
verted to a frequency read-
out on the display, there
are no adjustments or
alignments. I checked each
section for proper opera-
tion as they were put to-
gether The display and
drivers were checked by
substituting a BCD number
into each frequency posi-
tion. The PROMs of course
were checked during pro-
gramming and the con-
verters were checked to
make certain that they
faithfully followed the
binary number in the
divider. Once connected
together, the job is com*
pleted.
At first, I tried to make
use of all that room around
the speaker. So I made a
shield with a copperclad
board over the main board
and mounted the shield
very close to the main
board. This caused prob-
lems by changing the tun-
ing of the output circuit.
Moving the ICs up next to
the divider and removing
my shield board solved the
problem. I mention this
because, at first glance, it
appears that mounting the
hex buffers near the ac-
cessory socket is a good
idea, but it isn't. I used flat
ribbon cable and kept it up
and away from the rf cir-
cuits.
Because of the numer-
ous variations possible, I'm
sure that each frequency
display addition will be
done a little differently.
This article outlines one
way that it can be done, so
hopefully it will inspire you
to put one together for
your IC-22S.H
Photos by Jan Kaneshlro
The two 5-vo!t regulators add a tittle length to the
transceiver but operate quite coo/y being mounted on this
plate with standoffs.
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WARC v9 Preview
showdown in Geneva
The World Administra-
tive Radio Conference
(WARC) will reconvene in
Geneva, Switzerland, on
September 24, 1979. It is
scheduled to last ten
weeks at the International
Telecommunication Union
headquarters' complex.
The last WARC was held
in Geneva during 1959.
Delegates from over 100
countries attended to
discuss and revise regula-
tions that govern the inter-
national use of the radio
spectrum. Regional con-
ferences have been held
since then to review mat-
ters such as the handling of
third-party traffic.
To understand how
amateur radio as a hobby
fits into the global scheme
of things, one should be
aware of the purpose and
workings of the ITU. Therr
negotiations will lead to a
treaty that will have an
enormous effect on how
the communication ser-
vices of the world wif!
function.
History of the ITU
the ITU has existed for
over 100 years and is the
oldest of agencies that are
affiliated with the United
Nations. It first operated as
a separate body until the
UN absorbed it in an agree-
ment signed in 1947 It was
organized mainly to help
regulate the use of the
electric telegraph, which
was made available to
the public during the
mid~1800s.
Various treaties were
negotiated between the na-
tions of Europe. The
governments had to face
difficulties that would
have to be overcome.
When Prussia, in 1848,
decided to link its capital
with places on the borders
of its kingdom, it had to
conclude at least 15
treaties with the German
states to obtain the rights
of passage needed for the
building of telegraph lines.
The International Tele-
graph Convention was
signed during the 1865
Paris Conference by 20
countries. These nations
made up the International
Telegraph Union, which
was the original name of
the ITU.
Then, in 1895. the first
successful wireless trans
missions signaled the
greatest revolution in the
history of telecommunica-
tions: the invention of
radio. It was first regarded
as a radically advanced
form of telegraphy. Radio
spread across the interna-
tional scene more rapidly
than the telegraph had
With the rapid use of
radio as a form of conn-
munication, it became
clear that international
regulations were needed
to accommodate it. This
became apparent in 1902
when Prince Henry of
Prussia was returning
across the Atlantic from a
visit to the United States.
He attempted to send a
courtesy message to Presi-
dent Roosevelt. It was
refused by the operator of
a U.S. coastal station
because the radio equip-
ment on the ship was of a
different type and na-
tionality than that of the
shore station. As a result of
this incident, the German
government called for, and
convened, the 1903 Berlin
Radio Conference,
In three years, another
conference was held where
the first international radio
regulations incorporated
the principle that ships and
coastal radio stations must
accept messages from
each other.
The first World War
greatly stimulated the
development of radio, and
in the early 1920s, the In-
ternational Broadcasting
Radio Service began. A
new problem became how
to share the radio frequen-
cies to avoid the inevitable
interference between sta-
tions Even today, the
global responsibility for
radio frequencies remains
one of the ITU's heaviest
and most vital jobs.
It was not until the ITU
conference of 1927 that a
reference to the Amateur
Radio Service was made:
private experimental sta-
tions. The Washington,
DC, meeting allocated
bands of frequencies to all
of the various radio ser-
vices, including maritime,
broadcasting, and ham
radio. Hams had been
operating in the U.S.
before this year but were
now officially recognized
by the world community.
During the second World
War, broadcasting brought
the fact home to everyone
that radio waves respected
no geographical boun-
daries. It was apparent that
much wider world agree-
ments would have to be
drawn up for radio.
Radio Conference Pro*
cedure
The upcoming con-
ference's purpose is to
review the regulations cur-
rently in effect and to
devote the proceedings to
those needing revision. By
the time the official
delegations assemble in
Switzerland, governments
would have already firmed
up their positions with the
aid of private organiza-
tions and citizen groups.
Their views will have
212
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been submitted to the
Secretariat of the ITU and
published in a single book
of proposals. Copies then
would have been cir-
culated to all member na-
tions to enable each
delegation to know what
everybody else is thinking.
In the VS., negotiation
of the treaty is exclusively
the responsibility of our
State Department. Various
working groups have been
meeting for the past two
years hashing out what
they think should be the
final U.S. proposal The
Federal Communications
Commission considers
these views, and adds to
this their outlook. They
then publish notices of pro-
posals. Eventually, the FCC
will come up with their
final position paper and
hand it to the State Depart-
ment to begin the dip-
lomatic process.
Much of the nitty*gritty
negotiations are taking
place now and the actual
ITU WARC wilt seem anti*
climactic.
Let's examine the make-
up of the people who
can attend these world
meetings- Official voting
delegates from the various
nations have not yet been
selected but soon will be.
If the makeup of the last
conference in 1959 can be
any indication of what to
expect, countries will in-
clude various governmen-
tal department heads who
will administer radio law
back home. In our case, the
military brass would be in-
cluded along with people
from the FCC.
Representatives of pri-
vate companies can par-
ticipate along with people
from international radio
organizations. They can
act as observers only after
obtaining the approval of
the participating govern*
ments. They can look on
from the audience but can-
not actively have a say in
policymaking decisions.
On opening day, dis-
tinguished members will
be seated in a large room
of the ITU building to carry
out the formal opening
ceremonies. A chairman
will be selected who will
organize committees that
will meet separately to
take up the various issues
that brought them there.
Each nation wilt register
members for participation
in the discussion groups.
They will be meeting near
Geneva during the length
of the assembly. Toward
the end of the conference,
members will once again
assemble en masse to vote
on the new international
radio law.
In addition to commit-
tee meetings, there are
plenty of social functions
to attend. Much arm
twisting is done in between
the wine and the cheese
dip. The diplomatic of-
ficials of the world do have
a tradition of combining
business with pleasure.
Where else but in Geneva,
which is the world head-
quarters of our many
organizations [Red Cross,
Boy Scouts, etc.) that serve
humanity, should such
splendid parties be thrown.
These occasions are legal
ground for the con-
ference's observers to con-
fer with the delegates on
various matters.
When the treaty is con-
cluded and the officials ap-
prove, then it is up to each
member nation to ratify
the agreement In the U.S.,
our Senate has to approve
the final document. Our
services in the communica-
tions field do not have to
abide by the new regula-
tions until our government
makes it law. One ratifica-
tion process took our of-
ficials in Washington
several years to give it their
seal of approval Until
ratification, we continue to
operate under the present
treaty
U.S. Preparations
U.S. Preparations have
been actively under way
since 1975 at the Depart-
ment of State, the Federal
Communications Commis-
sion, and the Office
of Telecommunications
Policy (now known as the
Unltid Nations Photo
National Telecommunica-
tions and Information Ad-
ministration). The FCC is
charged with primary
responsibility for develop-
ing non-federal user re-
quirements. The NTIA is
primarily responsible for
federal government re-
quirements.
The FCC and NTIA are
developing the different
needs and requirements of
the US spectrum users
through close consultation
with each other and with
the State Department. In-
dustry and general public
interests have been
solicited by means of a
series of public Notices of
Inquiry, issued by the FCC.
Eight Notices of Inquiry
have been issued and addi-
tional Notices may be
released in the future The
Notices treat different
aspects of WARC planning,
most notably changes in
the international table of
frequency allocations.
How Much Can World
Politics Affect Amateur
Radio Bands?
There has been specula-
tion on how other nations
Headquarters of the Internationa f Telecommunkathn Union in Geneva, Switzerland.
214
view amateur radio. The
concern seems to be
focussed on how third-
world governments place
their communications pri-
orities. At the time of past
WARCs, many of these na-
tions were colonies of the
western nations and the
voting power of these col-
onies was held by their
respective ruling coun-
tries. The situation has
changed enormously since
the 1959 WARC; the
number of independent na-
tions has increased
dramatically. In Sep-
tember of 1979, 154 na-
tions wilt cast votes on the
many issues facing WARC.
Many of them will be na-
tions which were not yet
independent at the time of
the last WARC. The
balance of power has
shifted.
These new nations are
rapidly reaching the period
when their development
creates economic and
social needs to fill. As their
domestic and foreign
goals becorne clear,
amateur radio may not be
so important to them when
compared with commer-
cial, military, and govern-
mental interests.
If you look through the
list of those who hold
amateur licenses in
developing nations, you'll
find that many of the
licenses are held by
foreign nationals. In some
nations, you'll find native-
born hams in the govern-
ment or military, but not in
the population at large.
Most African authorities
consider hamming to be a
"white man's hobby" and
they discourage the
population from getting in-
volved with it. In many
cases, licenses simply are
not issued to natives of
these nations.
Can world politics
hinder amateur radio? This
is a hard situation to get a
handle on. One would
think that the U.S.5.R, bloc
might be against ham
radio, but in 1959 a very
curious thing happened.
Most of the ITU members
were attempting to slice
up the ham bands and
even threaten amateur
radio's existence. Then,
with the aid of the Com-
munist votes and our
hemispheric friends, we
gathered enough support
to salvage the service
without losing a kilohertzl
Last time we went into
the conference not asking
for anything special, like
the expansion of our
bands. WARC 79 may see
us asking for additional
bands due to some ser-
vices moving up to com-
munication satellites and
thus abandoning many
shortwave frequencies. We
may hear some countries
suggest that CB should
become a world service
and share the ham bands
with us. The political situa-
tion being played out at
the U.N. and its agencies
may spill over to Geneva.
This would put the
western world into opposi-
tion with the third world
just because it is the
fashionable thing to do. A
44-nation African bloc ap-
pears ready to vote for a
set of world frequency
allocations which will
mean drastic cuts in the
amateur bands. Many
other third-worid govern-
ments will probably follow
this lead.
We do have strong sup-
port in some countries, in-
cluding at least one in
Africa. Liberia is a staunch
advocate of ours because
of the way ham radio aided
that country during an
epidemic. Central and
South American govern-
ments know of our value in
providing disaster and
emergency communica-
tions. We do have friends
who will stand by us, but
the world is changing and
only time will tell what will
happen. ■
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Fig. 4. Tfiode voltage polar-
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9ELF BIAS
B
fig. 5, Cathode bias.
Class B is biased to the
cutoff point of the tube
curve, draws current onty
when there is a signal ap-
plied, amplifies only part
of the input signal per tube
(one half), has an output
that is proportional to the
input, and is considered a
linear amplifier It is also a
more efficient use of
power.
Class C is biased beyond
the cutoff point, only
draws current and has out-
put when driven into con-
duction, amplifies a
smaller portion of the in-
put signal (less than half],
has the largest and most
distorted output, and is not
considered a linear ampli-
fier It is the most efficient
use of the available power.
Class AB is a variation of
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It draws some current at all
times, is more efficient
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class B, and is less dis-
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That's it for tube bias
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thing about tube bias
which should be men-
tioned, Most tubes will cut
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There is, however, one
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This is the remote-cutoff
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avc (automatic volume
control) action is desired. A
strong signal would bias a
normal tube to cutoff and
the set would go dead, The
remote-cutoff tube does
not cut off. It just con-
tinues to reduce the gain.
Strictly speaking, that is
not a class of bias, but it
does have an odd tube
curve and function.
Now then, we come to
transistors. Here's where
we start to have troubles.
Once again the flim-flam
factor appears.
The transistor was a
triode— nothing more. Not
only that, it was a triode
with alt the troubles the
tube triode had and a few
more that tubes never
thought of. It was the new
toy that had to be sold and
a great deal of effort went
into making it seem like
anything but a triode. All
the bad things they safd
about triodes came back to
haunt them. And they were
trying to do all the things
with a triode that they were
using multi-element tubes
for.
There were a few prob-
lems, In a well-designed
circuit, a transistor can be
a reliable circuit element,
but many of the circuits
were not designed well and
got worse as they aged.
This quickly gave tran-
sistors a well-deserved bad
name. They had oversold
their retiability and rushed
into production with too
many transistor circuits
riding right on the edge of
their technology. To sell
them, they worked very
hard to disassociate tran-
sistors from anything to do
with tubes, particularly the
triode.
As far as possible, new
terms were given and even
new ways of arranging the
schematics so that tran-
sistor schematics often
have circuit elements in
different positions than a
tube schematic would. All
this overlooked one simple
thing: There are far more
similarities between tubes
and transistors than there
are differences. We will
need to fill in just a few
more tube items before we
can fill in the blanks. There
were some factors which
were deliberately drawn to
widen the gulf between the
two when, in fact, they are
just opposite ends of the
same stick.
Way back, ft was
thought that the tube grid
did not draw current, par«
ticularly in the class A
amplifier stage and the ear-
ly regenerative stages and
so forth. One theory held
that bias was a static
charge, a potential dif-
ference as at the poles of a
battery (which often sup-
plied the bias voltage).
While the voltage ap-
peared as a static charge at
the poles of the battery
and at the tube elements,
no actual current flowed.
It was not, in that sense, a
complete circuit.
But unless the Supreme
Court has declared Ohm's
Law to be unconstitu-
tional, grids draw current
All grids draw current.
The problem was that
the grid resistance might
be several million Ohms
and the voltage only a few
volts. The current was so
slight that it couldn't be
measured without upset-
ting the circuit.
Much has been made of
saying that the tube is a
voltage-operated device
and the transistor is cur-
rent-operated, as if this was
something different. Bunk!
There is voltage and cur-
rent floating around in
both of them. You can't
have one without the
other, no matter who says
what. Why then is there the
big problem? It's a matter
of impedance and sloppy
wording. Here, we will
have to use impedance and
resistance interchangeably
because we are dealing
with both the static dc
voltages and the signal
voltages.
It is a matter of conve-
nience to speak of the tube
circuit as voltage-operated
and the transistor as cur-
rent-operated because of
the resistance involved.
For convenience, think of it
as an amount of power,
even though it may be
small. The tube circuit has
a high resistance. The
signal is higher voltage,
which means that the cur-
rent will be very small. The
equivalent signal in a tran-
'-s -?
Fig. 8. Grid' leak bias.
sis tor is across a lower
resistance, which means
that the voltage on it will
be smaller but the current
higher.
You have seen this
before with antennas. An
end-fed wire is a high im-
pedance point, which
means a high voltage point
but low current. A dipole is
a low impedance feed-
point, which means a lower
voltage but a high current.
That's all you have with
tubes and transistors, just
a matter of convenience
when speaking of signal
transfer There is voltage
and current associated
with both circuits.
You will also see signal
sources referred to as a
current source or a voltage
source. It's the same thing.
The voltage source will be
higher impedance and the
current source will be-
lower.
Now we come to the
matter of transistor bias.
The classes of bias are the
same for transistors as for
tubes, and the definitions
hold true for them, too.
The transistor also has a
linear portion of its "cur-
rent-transfer" curve, and a
cutoff point. We do have
to make a distinction,
though. Here, we are
speaking of the normal bi-
polar transistor, not the
field-effect type which will
be dealt with later-
While the classes of bias
are the same, they are
arrived at in a slightly dif-
ferent manner. Even
though the transistor is on
the other end of the stick
from the tube, in one way it
behaves exactly opposite
from the tube.
If you look at the tube
curve, you will notice that
when a tube receives zero
-*
RI
F SATURATIOIII f>DMT
Fig. 9. Typical remote-cutoff tube curve.
bias, it will draw the max-
imum current, which can
be unhealthy. The tube
must be biased just to sit
there. The transistor is just
the opposite. Without bias,
it will just sit there and be
cut off. The trick is how
you bras it.
Look at the circuit in Fig.
10. Resistor R1 is the load
resistance for the tran-
sistor. It has the same func-
tion as the tube load
resistance (RL}, R2 and R3
are different ways to in-
troduce bias to the tran-
sistor. R2 is one of the more
stable ways to do it- Tran-
sistors are prone to a
number of screwball bad
habits. Thermal runaway is
one. When it gets hot, it
draws more current and
gets hotter and draws even
more current and pffft!
Either resistor will allow
a certain amount of bias
current to flow in the base
circuit, which is how the
transistor gets biased.
R2 gets the current from
the collector resistor. If the
stage draws more current,
the voltage drops and the
current drops through R2,
helping to stabilize the col-
lector current That is a
simplified circuit, but it
would work as a simple
amplifier.
Fig. 11 shows a few more
resistors in there. R3 is the
emitter resistor which is
usually bypassed. It also
has a stabilizing effect on
the stage. Often its value is
similar to many small sig-
nal tube stages, although it
is not exactly the
equivalent of the cathode
resistor. R4 is something
like a load on the grid, but
also helps the stability of
the stage. Its value is usual-
ly in the range of one-tenth
the value of R2.
Now we come to the
name-games people play.
With the modern tube, you
have the cathode, the grid^
and the anode or ''plate/'
Diodes have long had a
cathode and an anode, but,
when they got to the tran-
sistor, they had to think up
some new names and came
up with emitter, base, and
collector. That's not too
bad, just a little farfetched.
Then came field-effect
transistors [FETs), They are
the ones that think they are
tubes. We get back to volt-
age-operated again. Also
they wanted to disasso-
ciate them from those nas-
ty old transistors that gave
so much trouble.
FETs are compared to
tubes because they are a
comparatively high im-
pedance device, more like
tubes than transistors. The
words "field effect'' are
used because it is the field
of the input signal voltage
that makes them work.
They seem much more like
tubes than bipolar tran-
sistors. It would never do
to use the same names for
their new toy, so they came
up with source, gate and
drain. How imaginative!
You still have the same
classes of bias possible and
bias is accomplished with
FETs much the same way it
Is with tubes.
There are applications
with some tubes and FETs
that don't use an external
bias. These are small-signal
amplifier stages. The usual
high load resistance limits
the current as well as pro-
viding the load. The tiny in-
put signal to the stage has
the effect of riding in a
m
Fig. 10, A simple transistor
bias circuit
linear portion of the curve
over a short distance. Even
so, the tube does provide a
tiny amount of self-bias,
too.
Which brings us back to
the beginning, The tran-
sistor is just another kind
of triode. Tube and tran-
sistor bias do the same job
for the same reason. They
just do it somewhat dif-
ferently.
A tube is biased by ap-
plying a negative voltage
to the grid or by making the
cathode more positive
than the grid.
A bipolar (ordinary) tran-
sistor is biased by applying
a small current to the base,
or by biasing the emitter
with respect to the base.
An FET is biased roughly
the same way a tube is bi-
ased. The voltage and cur-
rents will be smaller,
though.
The FET either biases the
gate negative or the source
positive with respect to the
gate. If an N-type, the
reverse if a P-type.
While this discussion has
been a little shy on num-
bers and practical appli-
cations, it should help you
make sense of the more
detailed descriptions of
tube and transistor theory:
a backbone upon which to
hang more detail. M
Fig. 71. Conver^tional trarh
sistor bias afrangement
219
f
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Build the Flexi-Filter
a very active device
Donald Morur W3QVZ
3663 Hipsky Mtit Road
Woodbine MD 21797
Ever have need for an ac*
tive filter with tunable
multiple outputs, i.e., high-
pass, tow-pass, bandpass,
and a very sharp rejection
notch? The filter described
is a "state variable filter"
(svf). The 5vf described
here has an operating fre-
quency of 6 Hz to 60 kHz.
A good discussion of this
type of filter may be found
in the IC Op- Amp Cook-
book by Walter |ung and
the Active Filter Cookbook
by Don Lancaster. This svf
The various control functions and input/output connec-
tions can be seen in this photo. The various filter functions
are available simultaneousiy at the various phono jacks.
For those only interested in general communications use,
the top and bottom frequency ranges may not be wanted
Ir} this case, only two values of CI and C2 would be re-
quired. .022 and .0022 uF capacitors could yield a range of
60 to 7000 Hz.
uses 5 op amps. Four of the
op amps are contained in
the quad 3403 unit and U5
is a single LM318. (See Fig.
U
Functionally, the state
variable filter uses three or
four op amps. Two op
amps, U2 and U3, are con-
nected as inverting in-
tegrators in cascade. The
output of the second op
amp integrator is unity
gain, and is inverted and
fed back to the input of the
first integrator, U2. There is
also a feedback loop from
the first integrator back to
its own input to provide a
controllable amount of
damping
The input summing
stage, U1, combines oscil-
latory feedback, damping,
and input signals. If U1 has
properly scaled input and
feedback resistors, you can
independently control cir-
cuit gain, frequency, and
damping. The function of
U5 is to correct the band-
pass output phase so all
three outputs will be out of
phase at resonance, and in-
crease the gain of the
bandpass channel by
about 3 dB, thereby mak-
ing the gain of all three out-
puts equal within their re-
spective passbands From
lung's IC Op-Amp Cook-
book^ page 337, for the cir-
cuit in question: Given fi,
Ql, and Ho (passband
gain), select CI (C2) Ri "
1/(2TTfcC1). Choose R3, R4
= QR3, R7 = R6Q/Hobp
Example: f^ = 723 Hz, Q
- 20, Ho = Q. If RI = R2
and CI = C2 and RS = R6
= R7 = R8 = 10k, fc =
1/(2t[R1C11, Q = R4/R3,
Hobp = R6/R7[QL CI, C2
= 1/(2T!Rlfc) = .022 uF for
RI, R2 = 10k,
Construction
As can be seen from the
accompanying photos, the
unit is housed in a Bud
sloping-panel cabinet,
Model AC1613. A piece of
single-clad phenolic board
was utilized. An isolated-
pad drill mill was used to
produce isolated pads
through which Vector
"Mini-Klip" pins were
pressed in and soldered.
The layout and wiring are
not critical.
Filter Measurements and
Operation
The operating controls
of the filter are self-
explanatory and may be
observed in the accompa-
nying photos. The curves in
Fig. 2 were made as
described in the block
222
diagram of Fig. 2. The
audio oscillator output
was set at 100 mV at a fre-
quency of 1 kHz. The fitter
attenuator was then ad-
justed to produce 250 mV
output. Setting 250 mV =
0 dB, the low-pass filter
curve was plotted. As in-
dicated in Fig. 2, the Q con-
trol must be adjusted by
trial and error for the
smoothest (without peak-
ing) roll-off. The roll-off
was also observed with a
swept 70 to 10,000 Hz
audio signal applied to the
filter (see Appendix). The Q
control could then be ad-
justed by watching the
scope presentation for op-
timum roll-off shape. The
same routine was used in
the plotting of Fig. 3. The
change in the setup in the
plotting of Fig. 4 involved
changing the tuning con-
trol to 1.5 kHz and the Q
control to near minimum.
Thj^, tuning control must be
very carefully set at 1.5
kHz or an asymmetrical
plot will result. Examina-
tion of the 6 dB points of
the notch plot shows a Af
considerably underlOO Hz.
Fig, 5 setup conditions
were 10 mV filter input
with the filter attenuator
adjusted to yield 40 mV at
the bandpass output jack.
The tuning control was re-
checked for an accurate
1.5 kHz setting and the Q
control was set near max-
imum. This curve indicates
a Af substantially less than
200 Hz. When this filter
was built, no attempt was
made in matching the resis-
tor and capacitor values in
the tuning circuits (com-
ponents with asterisks in
schematic). An improve-
ment in maximum selec-
tivity may be possible by
doing this, for those con-
cerned with obtaining op-
timum selectivity.
Filter Tests
I have made a number of
listening tests on my Ken-
wood R'599 receiver with
the filter interposed be-
tween the receiver output
INPUT fATTCNJ
R7
R5
3 OK
-^
laK
^
500a
— V%rti —
CI ""^ *R? "C2
,022 M&K ,^ .022
^h
JTX
R4
iOk
iOk "O"
^irX-
-^ NOTCH
^
BfiNDPfliS?
HIGH
?7 5
5K R,
t'vVV-
rh
•;>-. «-»;y ■;•:•:<
fig. 7. Versatile audio filter schematic diagram + V = pin 14; — V — pin 7. U1, U2, U3,
U4 = 3403 quad unit U5 = LM318. Tune with *R1, R2 = ganged 10k pot. If *Ct C2 =
.022 uF, fc = 723 N, with RF1, R2 maximum. Range switch not shown. CI, C2 = .0022,
.022, .22, and 22 uF.
(headphones jack) and a
pair of low-impedance
headphones. The filter will
produce as much as 2 volts
rms outpijt into a low-im-
pedance headphone load
with only a few mV rms in-
put at the bandpass output
jack of the filter, with the
filter attenuator set at
minimum. One can then lis-
ten to sideband signals
with typical QRM situa-
tions and hear the effect of
the low-, high-, or bandpass
filters by varying the filter
tuning and Q controls. The
notch output was very ef-
fective in rejecting CW
signal interference when
listening to phone signals.
The receiver output was
also fed through the filter
to a separate audio power
amplifier driving a speaker
to compare more directly
with the receiver's own
speaker output. There was
definite improvement in
the clarity of reception of
various phone signals (SSBJ
by juggling the tuning and
Q controls and listening at
various filter output jacks.
The filter was not as selec-
tive as the Kenwood fixed-
tuned CW filter regarding
CW reception, but was def-
initely superior as an ad-
justable phone filter. The
Kenwood SSB selectivity
position is a low-pass filter
rolling off rapidly beyond
2.5 kHz. While generally
satisfactory, under ex-
treme conditions of QRM,
the audio filter afforded
definite improvement in
speech intelligibility and
reduction of prolonged lis-
tening fatigue.
Another interesting ap-
plication for the audio ex-
perimenter would be as an
audio sweep marker. By in-
terposing the filter be-
tween the audio preamp
output and power amp in-
put and applying a swept
audio signal to the audio
system, the rejection notch
would appear on the scope
presentation as a narrow
notch in the sweep. The
position and depth of this
marker would be a func-
Q CONTT^CJL
SET TO HIQH
Odfi -
to
HEATH
AUPIO
FILTER
HEflTH
AKOIO
VTVM
;^di',asv
AUOIO osc
OUTPUT-^O0mV
\
1^ £0
<t
z
LU
K
< 30
4Q|-
ATTENUATOR SET TO
PROpUCe S50mV AT
(_0W PASS OUTPUT JACK
TUNING KNOe SET
FOR HChz
O CONTROL SET FOR:
SMOOTH ROLL-OFF
(SEE 4PP£N0tK}
50-
-L
2 3
FRegUENCY {KHiJ
Fig. 2. Low-pass filter characteristics.
QdB
10
o
20
5 30
m
40
50
Q CONTROL
SET TO WJGH
\,
J.
100 £00 300 400 500 &00 70O BOO 500 IK
FREQUEMCV (KHa)
L4 K
p-t-t; -Wv-"" 9 *fi?rK|K« ♦■wacsMrK- ;
■* '^^"■K:^;:'^*c5^*'-my;:ytji^
Fig. 3, High-pass filter characteristics. The same test condi-
tions as Fig. 1 were used except for 250 mV at the high-pass
filter output jack.
223
Miai^M^s^^^^tSfaSI^Ki4i^miiiii^mm
Bottom view shows copper-dad phenolic board construction as explained in text
tion of the tuning and Q
controls respectively. Any
portion of the audio sweep
could then be read from
the frequency dial on the
filter. This would be conve-
nient for measuring roll-off
rates of other filters under
test equalizers, etc. The
audio filter tuning dial was
calibrated by applying a
known audio frequency
and peaking the tuning
control (while observing
the output in the notch
mode) for a null. This mode
was used since it has the
sharpest tuning indication.
Conclusion
The application of the
filter is limited only by the
imagination of the user. In
the notch mode, it could
meet highly selective null-
ing circuit requirements
such as tape-beep cueing
removal, suppression of
QRM in SSB and CW sig-
nals, 60-120 Hz hum sup-
pression, etc. The notch
mode could also be used as
the basis for total har-
monic distortion analysis
measurements. The state
variable filter makes
available an active filter
with high stability, predic-
tability, and wide tuning
range at a very moderate
cost and relatively easy
construction.
Appendix
A measurement was
made (data not included)
which cor>sisted of apply-
ing a swept audio signal to
the audio filter. The source
was a ''Clarkstan" sweep
frequency phonograph
transcription played back
through a very flat Empire
phono pickup. The filter
was connected at the out-
put of the audio power
amplifier and an oscillo-
scope was connected to ex-
amine each filter ouput
mode. The characteristics
of the sweep record were a
Af of 70 to 10,000 Hz, at a
20 Hz sweep rate. The ef-
fect of the Q control of the
high- and low-pass filters'
roll-off rates was observed,
The roll-off rate could be
controlled (increased or
decreased} by the Q con-
trol, but a setting yielding a
smooth roll-off was set to
plot Figs. 2 and 3. Higher
settings of the Q control
were employed when plot-
ting the bandpass mode,
Fig, 5. The dotted lines in
the plots of Figs. 2 and 3 in-
dicate the effect of raising
or lowering the Q control
settings, High-Q operation
really only pertains to the
bandpass mode. As can be
seen, an excessive Q set-
ting produces a hump or
peaking in the low- and
high-pass modes near the
cut-off frequencies- Ex-
cessive Q in the notch
mode likewise reduces
notch selectivity, A Q
value of \^2/2 theoretically
produces minimal peaking
(Butterworth response). For
those desiring more de-
tailed design information
on the state variable filter,
as well as other types, a
copious amount of data is
available in the aforemen-
tioned books by Jung and
Lancaster. B
lu
m
50 r
40 -
30-
20
10 -
OdB
10
13
■0^^B
Fig. 4. Notch filter characteristics. The same test condi-
tions as in Fig. 1 were used except the tuning was set for 1.5
kHz and Q control was set for best notch (near minin}um
Q settingl See Appendix.
Fig. 5, Bandpass filter characteristics. The same test condi-
tions as Fig. 7 were used except 10 mV input to filter, at-
tenuator set for 40 mV output for bandpass output jack,
tuning control peaked at IS kHz, Q control set near max-
imum. See Appendix.
224
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PHONE NO. (605)-886.7314 P.O. BOX 73 WATERTOWN. SOUTH DAKOTA 57201
The Klassic Kilowatt
four 811 As do it
Dave Ingram K4TWJ
Eastwood Village No. 604N
Rt, //. Box 499
BirmmghQm AL 352 10
One of the most
popular rf amplifier
circuits in use by today's
amateurs is a grounded-
grid configuration of S11A
tubes. Four of these tubes
can provide the basis of a
flexible and economical
amplifier which uses readi-
ly available parts, operates
from home brew 110-volt
power supplies, and is only
2 dB weaker than a large,
power-consuming 2 kW
unit. My previous ex-
Fronf view of classic amplifier shows R,L Drake cabinet
and knobs. Illuminated Heathk it-type meter is modified to
read amplifier plate current, grid current and relative out-
put
perlences with ''legal
limit" amplifiers have been
a combination of back-
breaking power supplies,
special 220 V ac lines,
elaborate cooling systems,
and offensive TVL Few
problems have been expe-
rienced with this 811A
amplifier, however, and I
still have plenty of power
for competitive operation
in DX pileups.
The circuit (Fig 1) of my
amplifier is not a new
design. It has been used
(and proven!) in equipment
for several years. A very
similar circuit is used in the
Collins 30L 1 linear ampli-
fier. The difference in my
unit is its layout and design
for station compatibility.
Rather than using a surplus
Classic amplifier in service and operating normally. The 4
817 As add a soft glow to any ham shacL Room is dimly il-
luminated for slow scan TV operations.
226
»*^ OUTInJT
COIL DATA: LI (10 METERS^- tf^'*
COPPER TUBING. 1' LONG BV
Vh" DIA>. 7 TURNS- L2: B & W
3905-A. 4" LONG BY 2W DiA.. 20
TP1, TAPPED FOR 15. 20. AND 40
METERS. Zt, 22 fPAHASlTiC
SUPPRESSORS) 4 TURNS NO 16
WOUND ON 47 OHM. 2 WATT RE-
SJSTOR.
1 1 D VAC
NOTE: Rt THROUGH R5 ARE
2DIL, 20'WATT. CI THROUGH G5
ARE 200 UF. 600 VOLT.
■►rO MEtER SWITCH ©PLATE
Fig. 1. Classic rf amplifier schematic diagram.
enclosure for the amplifier,
an empty cabinet that
matched my transceiver
was purchased directly
from the manufacturer.
Matching knobs were also
purchased from the same
manufacturer. In addition
to working beautifully, the
completed amplifier
blends perfectly with my
Other station equipment.
The overall result (which
includes similarly matched
stow scan TV gear) Is a
''commerciaT' appearing
setup that's enjoyable to
own and operate. The in-
formation presented in this
article is intended to serve
as a guideline for others
desiring to construct
amplifiers, antenna tuners,
monitors, etc., which may
also match their particular
setup.
Amplifier Mechanical
Details
The amplifier's 811 As
are mounted horizontally
in the cabinet and all input
circuitry is mounted in the
81 1 As' rear-supporting
chassis. A bottom plate is
fitted to this chassis, thus
totally isolating input and
output signals. This design
eliminates the necessity of
neutralizing the amplifier.
Four pieces of 3-inch metal
channel (I used Seezac
plates) are fitted together
and used as a framework
for the amplifier. The
upright rear chassis and
front panels are bolted to
this frame, as shown in Fig.
2. All the amplifier's out-
put circuitry is mounted rn
the center of this "free air"
space. Exact size of the ver*
tically mounted rear chas-
sis and metal framework
varies with the specific
cabinet used to house the
amplifier A small minibox,
with holes for the front
panel meter and incoming
wires, is used as an rf-proof
meter case. The meter
switch and the meter's
pilot lamp are also en-
closed by this case. The
plate-tuning and load ca-
pacitors are surplus units
which mount directly to
the amplifier's front panel.
A 10 meter tank coil is
mounted between the
plate-tuning capacitor and
bandswitch, while the
larger tank coil mounts
behind the bandswitch.
Both coils are supported
by their leads. A small
phonograph motor fan,
mounted on the amplifier's
left side, cools the tubes
during use. Sub-chassis
mounting of the 811 As is
accomplished by using
long screws and spacers, as
shown in Fig. 3. A similar
arrangement permits all
rear panel amplifier con-
nections to protrude
through the removable
rear chassis plate.
Due to the high
temperatures produced in-
side 811As during norma!
service, their rectangular-
shaped plates should be
situated vertically for
structural support, as
shown in Fig. 4. This will
prevent a hot filament
from falling against a grid
or plate,
A local sheet metal shop
cut and drilled the ampli-
fier's front panel for five
dollars. 1 merely painted
the panel to match my
TR-4 and mounted it on the
amplifier. The amplifier's
framework is directly
mounted in the bottom
part of the TR-4 cabinet,
and a thin piece of extrud-
ed aluminum covers the in-
side of this bottom to pre-
vent TVL The rectangular
slots in the bottom part of
the cabinet would allow rf
to "leak out/' but the
round holes in the extruded
aluminum prevent rf leak-
age.
Amplifier Circuit Delails
As previously men-
tioned, the basic circuit of
this amplifier has been in
use by amateurs for several
years. Similar circuits have
also appeared in many
amateur publications and
handbooks. The minor
variations of components
in each schematic are
227
interior view of kilowatt amplifier reveals layout of components discussed in text Note
eyctruded aluminum fining in bottom of cabinet for TV I reduction.
prime examples of the
amplifier's flexibility.
While some 811A circuits
include tuned inputs, my
unit simply feeds incoming
rf directly to the 811 A
filaments through a .01 uF
capacitor. Naturally, tuned
inputs for each band can
be included if desired.
Suitable filament chokes
which may be used with
the amplifier are the B&W
FC15A and FC25A or Ami-
don's new filament choke
kit. The filament choke in
my particular amplifier is
an SB'200 replacement
type obtained from Heath-
kit
Although a B&W 851
tank coil and bandswitch
assembly may be used in
this amplifier, I used a
4-inch section of B&W
3905 coil stock and a
separate 10 meter coil Ap-
proximate tap positions for
each band were located us-
ing a grid-dip meter. Then,
exact positions were lo-
cated by moving these taps
±3 turns and noting the
corresponding change in
output power. Presently,
the amplifier's 20 meter
output power is 750 Watts.
The bandswitch is a rela-
tively heavy-duty unit ob-
tained at a hamfest bargain
f Ait
TANK COiL-
p — s — p — s
table. Any porcelain switch
with large contacts should
work equally well
T-R switching and 811 A
biasing is accomplished
through the use of a —125
V dc divider network,
which consists of a sen-
sitive 10k Ohm plate relay
and a 7500 Ohm pot. This
network is ungrounded
during receive, thus apply-
ing approximately —125
volts to the 811 A grids as
cut-off bias. When the
transceiver's relay grounds
this T'R line, tube bias is
reduced to approximately
— 4 volts. The pot should
be adjusted to produce 60
or 70 mA of idling current
on the 811 As [transmit
mode with no input driving
signal), and the amplifier is
ready for action.
Power Supply Details
Operating voltages for
the amplifier are furnished
by a home-brew power sup-
ply built in two mating
chassis. A sketch of this
unit is shown in Fig 5.
Three large series-con-
nected TV transformers are
mounted inside the bottom
chassis. The filament
transformer, bias^supply
transformer, and power
control relay are also
mounted in this chassis.
The series rectifier and
filter capacitor board is
mounted on top of this
chassis. The upper chassis
provides a "top" for the
power supply. It is cut and
fitted with corrugated
aluminum for ventilation.
The two chassis are held
together by a front panel
and a steel strap screwed
into the rear of both
pieces A sheet of heavy
perforated aluminum also
covers the bottom chassis,
thus serving as a bottom
cover for the power supply.
A "whisper fan" is
mounted above the power
supply to provide addi-
tional cooling.
Operation
Amplifier tune-up is
straightforward and fol-
lows conventional plate-
tuning techniques. Re-
member to use minimum rf
drive when initially loading
the amplifier to avoid high
off-resonance plate cur-
rent. If you have any old
811 As, this initial tune-up
time is ideal for their use.
Once the amplifier is work-
ing properly, you can make
a chart of the load and
plate settings and output
WEAR PAKtL JACK
NUTS
aANQSWFTCH
TUfiiNG '^ METER
CAPACITOR
ftEAFT PAHBl
NUTS
3 1/2'
SCREWS
•—CMASSiS
2* SCftE«S
fig* 2. Top view of component layout tn kilo
amplifier.
Fig. 3, Mounting arrangement for tube sockets and parts
used in the amplifier.
228
FlUA^EJVTS
»WClS%Et> PLATE vgLtA^e HtTER
PMlTt
Om PLUTE
ENVELOPE
»OM,fiD
■9'5EP?F£S
COKINECTED
rf?&hr5F0RMERS
K- FTAY SIDE VIEW
■FILAMEMT
Tfif AM? FORMER
ff^mi VIEW
Fig, 4. End view of 811 A as seen from front panel. The
filaments should be positioned as shown. The top of the il-
lustration corresponds to the top of the amplifier
Fig, 5. Power supply cabinet arrangement.
power level for each band^
This chart will serve two
purposes: It will help keep
you from running the plate
current more than 50 mA
off resonance and it will
help you realize when the
finals eventually begin to
lose output.
Typical operating pa-
rameters of my amplifier
are 1 700 volts at 800 m A on
20 meters, producing 750
Watts output. These rf
levels are possible because
grounded-grjd annplifiers
allow the driving power to
directly add with the out-
put power
Conclusion
As this article illustrates,
the 811A amplifier
is one of the most ver-
satile and inexpensive
amplifiers that an amateur
can build and operate. The
concept of separating rf
and power supply sections
is also quite appealing to
many amateur setups. The
ttme-proven circuit is easi-
ly adapted to one's par-
ticular station arrange-
ment, thus producing a
reliable finished product
which can be enjoyed for
many years. Recently, I
purchased a new R. L.
Drake TR-4 CW transceiver
and considered purchasing
a new linear amplifier also.
After several weeks of
deliberation, I concluded
that my seven-year-old
811 A amplifier couldn't be
beat. I replaced tubes and
filter capacitors, cleaned it
like new, and It's now
ready for another seven
years' service What more
could one ask?
I would like to thank
Erskine lackson W4CEC
for his assistance in the
design and layout of this
amplifier. Erskine's in-
genuity was the prime con-
tributing factor to the
amplifier's professional
results. Thanks also to
Robert Perkins of Bir-
mingham AL for special
processing of the photo-
graphs used in this
article ■
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229
Ham Radio Goes to School
W-year-olds love it!
William L. Lazzaro N2CF
}! Jefferson Street
Highland Mills NY 10930
i i LJ ey, Mr. Lazzaro,
I I we got Maine! Our
RST was 579, and the guy
didn't believe us when we
told him we were only 10
years old,"
Teaching fifth*grade
youngsters at Montebello
Elennentary School in Suf-
fern, New York, has been
an exciting experience for
me But when I introduced
my students to amateur
radio, my vocation as a
teacher took on incredibly
exciting dimensions.
I began my introduction
to amateur radio one day
without prior announce-
ment. It was in December,
1975, and I had just pur-
chased a new Yaesu FT-
101 B. I obtained permis-
sion from the principal to
put up a 40 meter dipole
and I was in business! As
the children came into
school that day, their at-
tention focused on the
gray box in the corner of
the room. Ten-year-ofds
are curious souls and they
had many questions about
it. Finally, the moment ar-
rived for our first QSO. I
went back to the rig,
grabbed the mic. and
called my first CQ^ That
CQ has echoed in the halls
of Montebello School for
the last three years. Little
did I know at the time that
I was ushering in a new era
of excitement for those ele-
mentary-school students.
In that first year of
operation from my class-
room, we worked 17 states.
All my students received
QSL cards from gracious
amateurs and everyone
had a chance to talk over
the air
It wasn't long before my
students wanted to know
how they could become
hams, I explained the FCC
requirements for the
Novice license, but I per-
sonally felt 10~year-olds
were just too young to get
a license.
Since fifth-graders enjoy
secret codes and ciphers, t
introduced my students to
Morse code, To my utter
amazement, all my stu-
dents loved it! Many
learned it so well they could
communicate effectively
in code. The year ended in
)une with sad faces as my
students and I realized our
exciting year with ham
radio was ending.
The next September, 1
began teaching radio
theory and Morse Code
long before t brought in my
rig. Our year was very suc-
cessful in making contacts,
but the children loved the
code the best! The profi-
ciency exhibited by the ma-
jority of my students
amazed all who witnessed
it. We had sent Morse code
with flags from mountain-
top to mountaintop while
/ found flash cards to be a valuable teaching aid for Boys and girls exhibit equal enthusiasm and prof iciency as
reviewing material already taught. operators.
230
hiking, and we sent
messages across a lake at
night using flashlights
while camping. We even
made some on-the-air CW
contacts! I was now con-
vinced that the average
lO-year-old could learn the
code and use it proficient-
ly.
As September, 1976,
roiled around, my attitudes
toward the possibility of
10-year-olds getting li-
censed were changing
One of my first-year
students had gone to get
his General class license!
He skipped the Novice
license, stating it was too
easy! (Presently he is in
ninth grade and holds an
Extra class license with a 1
X 2 callsign to boot!)
t taught my students the
code and I operated por-
table from my classroom
with the FT-101 B. As spring
came, I had a group of six
students, three boys and
three girls, who were most
proficient at code and who
wanted to be hams. I decid-
ed to see how much theory
they could learn. We began
classes at noon hour and
recess. They learned quick-
ly as long as I taught them
in little steps and on one
topic at a time. We re-
viewed constantly what I
had already taught. (Later I
was to find out that flash
cards would be of great
help in reviewing.) In May,
all six took their Novice ex-
ams and passed!
The realization that I
had a problem now be-
came apparent. 1 had six
10-year-old licensed radio
amateurs on my hands and
no gear for them to use,
save a CW QRP rig I had
built. It was ludicrous to
think a fifth-grader could
finance his own station, so
I began the search for fund-
ing for ham radio equip-
ment to be located at
school.
My principal alerted me
to the possibility of a dona-
tion from our Parent-
Faculty Association, It
seemed that they had had
an unusually successful
year at fund-raising and
they were looking for a gift
to present to the school.
I wrote out a detailed
proposal for the station
equipment I needed and 1
planned an extracurricular
program for a ham radio
club. I presented my plan
to several members of the
PFA executive board and I
received a chilly response.
I would have to convince
the PFA that my plan was
worthy of their support if I
was to get the funding I re-
quested.
An invitation to speak at
a PFA meeting gave me my
opportunity to "sell" ham
radio. After carefully plan-
ning my presentation, 1
gave it to them with all the
enthusiasm of an ardent
amateur radio operator! As
the meeting ended, I not
only had gained the fund-
ing I requested, but I also
had many offers of help!
Even some of the mothers
asked if they could get
their own ham licenses
through my program!
I was thrilled! My dream
of having an amateur radio
club station at school was
going to be a real ity. Unfor-
tunately, I was to learn that
several problems would
have to be solved before
my dream came to fruition.
The first difficulty I ex-
perienced was finding
gear. I had received
enough money to purchase
a low-cost used SSB trans-
ceiver. My first inclination
was to check the classified
ads in ham magazines.
There was nothing listed at
that time which was
suitable. Then I began call-
ing dealers, hoping to find
a trade*in. 1 contacted
more than ten dealers and
none of them had a thing.
At this point I became
aware of the severe scarci-
ty of low-cost used ham
gear.
I wondered if I'd be able
to find appropriate equip-
ment in my budgeted price
Brian WB2Q0V demonstrates the way it's done.
range. My search lead me
to a brokerage firm. They
had a Heathkit HW-lOO
listed. I snatched it up im-
mediately and considered
myself lucky.
Setting up the station
was relatively easy. I at-
tached 2 X 4s about eight
feet high to protrusions on
the roof of the school, and
I strung up my dipoles. As I
ran my transmission lines, I
wondered about the line
loss. Each transmission line
had a run of 200 feet and
we couldn't afford any-
thing better than RG-58/U
coax.
My concerns were
calmed, however, as I load-
ed the forty meter dipole
and worked several sta-
tions with good reports.
It was difficult to con-
tain my excitement any
longer. Although it was on*
ly August, I called together
my vacationing Novices
for a club station christen-
ing.
We met together after
nearly two months without
any CW practice. As we
sent our first CQ with the
club station, six nervous
Novices, armed with pen-
cils and paper, crowded
around the HW-100 anx-
iously waiting for a con-
tact.
Suddenly we heard the
sweetest sound any ham
can hear! Our callsign was
being sent to us in pure dc
notes. It was music to our
ears!
The excitement of that
moment quickly turned in-
to a mild panic as rusty
minds struggled to copy
the callsign being sent to
us, "I didn't get thatr
''He's sending too fast/'
"What's ■ — ■■r' 'M can't
remember/' These words
Severat YLs log another QSO made from our dub station,
WB2RZP,
231
filled the station as ner-
vous hands wrote the mes-
sage being sent to us.
Once it was our turn to
transmit, another problem
developed "What should I
say, Mr Lazzaro?'' was the
question asked of me. As I
hurriedly wrote out a mes-
sage format, I began to
reahze that I still had a lot
to teach these newcomers.
CW abbreviations and
operating format were not
required material to get a
license, yet they were
essential to know; I had to
teach these Novices this
material and fast-
Later I prepared a wall
chart of a typical QSO and
another with common CW
abbreviations. We worked
together to learn both,
Once this was accom-
plished, I thought my prob-
lems were solved. Not so!
For some time, my
students made hit-or-miss
contacts. Sometimes they
achieved complete QSOs
and other times they only
received the callsign of the
other station. Then the
percentage of incomplete
contacts or no contacts
began to outstrip com-
pleted QSOs. The log
showed remarks like ''tost
transmission'' and 'QRM.''
I decided to go on the air
myself and see if the rig
was working properly. I
made a contact imme-
diately and had a complete
QSO without any difficul-
ty. I was sure the rig
worked.
That week I made ar-
rangements to actually be
in the ham shack while the
Novices went on the air.
After only a few minutes, I
realized the problem. They
were sending CQ at about
thirteen words per minute.
When a station answered
them at that speed, no one
could receive it, since their
code speed was still well
below thirteen wpm.
We set up a verbal rule
stating: "Send only as fast
as you can receive/' That
corrected our problem.
The logbook began fill-
ing up with completed
QSOs. We even began col-
lecting QSL cards at a high
rate of speed.
After school Novice
classes commenced in Oc-
tober of 1977. By February,
1978, we had ten more
Novices, with more on the
way.
Today the Novices are
operating at lunch and
recess for one hour a day.
Those who have taken their
exams and are waiting for
the results act as third par-
ties when the Novices
operate. These future hams
are getting actual orhthe-
air experience while learn-
ing what they will need to
know as operators.
My program has arrived
at almost a self-perpetuat-
ing point. There are
children at all levels, with
those children at the higher
Our famous value-packed mail order catalog
filled with thousands of Amateur Radio items.
Now ready to roll and yours for the asking . . .
Call Tufts today for prompt delivery of your
Amateur Radio needs from our tremendous
inventory. Let us show you why Tufts is the leader
in mail order sales.
Our crew of 100% hams, very competitive prices, and reliable modern
service facilities ensure your complete satisfaction. Call toll free daily
9-9 and Saturday 9-6. l-{800) 225-4428,
level helping those at a
level below them.
The excitement gen-
erated by our ham station
has been incredible.
Students are signing up for
my Novice classes in
droves ( I had 35 in the fall).
Children talk about their
ham radio contacts instead
of talking about television
shows. At recess, children
send code to each other us-
ing buzzers instead of play-
ing games.
It should be noted that
of twenty-six Novice oper-
ators, there are ten YLs. I
made it a point to en-
courage both sexes equal-
ly. It has paid off!
Montebello School
hasn't been the same since
that first CQ in 1975. We
are now looking ahead to
upgrading and the joys of
General class operation*
But can ten-year-olds get a
General class license? I
wonder. Here we go
again? ■
*^T3
209 S Mystic Avenue
MedfordMA02155
1-(800]225-442B
1 (61 7)395-8280
THE
BANTAM
DIPOLE
MM
NTER
S^jid S.A.E. for spec sheet
U.S. patent pending
Dealer inquiries invited
^C75
Laurel Plaza-RteiSS
Laurel MD 20810 301-792 0600
30-day fiionov beck
plus UPS shipping
The HF BANTAM DIPOLE \s a truly portabts all-band miniature dipol© complete with Its
own carrving case and maat.'hardware to mcmot on a camera tripod (3^8" x 24" adaptor
available). High performance Is obtained on BO^IO meters at its normal 13 foot length or
thfl- same antenna may be shortened to 7 t&et tot 75-10 meter coverage. FolBrizstion is
quickly interchangeable from horizontal to vertical. No ground system necessary. The
BANTAM DIPOLE is Ideal for camping, travetlng, mountaintopping, apartment living, or
if you're stuck with building code restrictions ConstmctSon is oi high quality 606tT6
aluminum and stainless steel hardware.
DRAKE •ICOM'TEN-
• TEMPO • WUson
232
p^ Rfffltfer S€f)fic0—aee p&§e 323-
Midland's 13-510 Is One Great 2-IVIeter Mobile.
Our
510A
Even Better!
■
^^^^^^^S^^^^^^^t
Ti pgwi!* ■
1^1 4'K
i^A. 1 J
flJt SI
r-
mtUnfr—^^M ' ^
J4lDI_AISID
H^ftr^^^Th^^^^^^l
^^^^^^^^p^i^^Huli^^l
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^^^^^^^^^^^^^^^^^^^^^^H
A SICHs yr itff ATIt
1
.
<
r^ F-
& MP SlMI»LiX
t4S 144 -f^AaO
HI 1/
143
I
141
tew
TX PWR
VOL
BAND
TX OFfSfT
X
NEW^ The 13'510A P.L.L synthesizer delivers 1,200 frequencies between 143.00
and 149.00 MHz ... the full 2-meter band, plus MARS.
NEW! '^^^ 13-510A will operate with up to a 6 MHz split between TX and RX
frequencies.
NEW! ^^^ 13-510A microphone connector is pre-wired for your Touch-Tone*
encoding microphone,
NEW! ^^^ 13-510A has a 7-pin accessory connector for your Touch*Tone^ dial,
tone-burst generator or discriminator meter. ^TenH^Tcme is a registered trademflrk of ATai
NEW! ^^^ 13-510A is compatible with available popular CTCSS continuous tone-
coded squelch system accessories. ''
NEW! ^^^ 13-51 OA has 3 transmitter outputs: 1, 10 and 25 watts.
Midland's 1 3-510, with its commercial-type modular construc-
tion, earned its reputation as one tough 2-meter FM mobile.
Now Midland has made the 13-510A an even more versatile
performerf
The 13-510A P.LL. synthesizer splits the 6 MHz spread be-
tween 143.00 and 1 49,00 into 600 discrete frequencies, and a
5 KHz up-shift delivers 600 more for a total of 1 ,200 . . . shown
directly on the digital display. In addition, there's access to 4
available offsets for repeater operation on ± 600 Hz with crys-
tals supplied or up to 6 MHz spread with your crystals installed.
Inside the 13-510A. there's a highly sensitive {0.3 uV), highly
selective (-70 dB at ± 15 KHz) dual conversion receiver with
dual gate MOSFET RF and mixer stages, crystal filter in the
1 st IF ceramic filter in the 2nd fF, arxJ helical resonators in the
RF amplifier.
The transmitter is conservatively rated for 25 watts output,
switchable to 1 or 10 watts for repeaters, and uses direct FM
modulation to deliver natural sounding audio.
Other features making Midland's 13-510A the one to look at
include automatic protection circuit for the output transistor,
internal DC filtering and polarity protection, a deep-finned heal
sink for the power transistors, and electronic switching that
needs no mechanical maintenance. Mobile mounting bracket.
base stand and push-lo-talk microphone are ir>cluded.
CHECK OUR specs:
RECPVER. Type: dual conversion superheterodyne 1st IF frequency: 16,9 MHz. 2ncl IF frequency: 455 KHz. Sensitivity: Lbsb
than 0,5 uV for 20 dB quteting (0,3 uV for 12 dB SINAD), Spurious response: -60 dB. Squelch threshofd: Less than 0.3 uV.
Modulation Acceptance. ±7.5 KHz. Sdectivlty: -70 dB at ±15 KHz. Audio output power: 1 .5 watts at 8 ohms,
TRANSMrrTER. Outputs: l , 10. 25 watts Frequency deviation: Adjustable 3-16 KHz {normal 5 KHz). Audio Input: 600 ohms.
M6dufatiDn system: Direct f M Spurious Radiation: less than -60 dB below carrser
GENERAL. Poww: 13-6 votts DC, negative grourKl. Current drain: Transmit, 2-7 aii^s.; r^^ive, 0,S amps, average. Antenna
impedances 50 ohms. Unit sae: 2-5,8 " x 5-13/16" x 9-5,8' . Unit weiglit: 6.6 lbs.
Want to know more? See your
Amateur Radio Dealer for Midland Quality
'PX.L. "220" MOBILE
•CRYSTAL 220" MOBILE
•ANTENNAS & ACCESSORIES
p , , or write for free full-color brochures.
»^II41
UNITE R M AH" I O M
P.O. Box 1903, Kansas City, Missouri 64141
y^ ReBeffif ServiCB—sea fiag^ S23.
233
Jim Garrett K5BTV
619 Cimmaton
Lewisvitfe TX 7S067
What's Your uF?
a six-digit answer
The following project
VieJds a simple but ac-
curate digital meter to
measure capacitance val-
ues from 1 pF to 999999 pF
(1.0 uF].
Theory of Operatian
The theory of operation
is based on the equation
I = C(dv/dt). Rearranging
the equation, C = l[dtidv),
where C is pF, I is
microamperes, dt is in-
crements of one ^s, and dv
is change of voltage in
volts across the capacitor.
In other words, if a
counter chip were to count
the time it took a given
capacitance to charge
from a constant current
source to some fixed
voltage level, that count
would be equivalent to the
capacity being measured.
A block diagram in Fig. 1
further describes the
operation.
The start-measurement
switch drains the charge
from the capacitor under
measurement and diverts
the constant current
WF
source to ground. Also, the
1 MHz pulses are not
allowed to accumulate in
the counter.
Upon activating the
start-measurement switch,
the capacitor begins charg-
ing. The counter is ac-
cumulating the one micro-
second pulses, and the
race is on. The capacitor
charge voltage, upon
reaching the threshold of
the count-inhibit line of
the counter, prevents the
counter from accepting
any ryiore 1 MHz pulses.
Therefore, the contents of
the counter can be
displayed directly as the
value of the capacitance
being measured.
Returning to the equa-
tion one last |jme and
assuming an example, ex-
amine what capacitance is
represented in the follow-
ing (where I = 5 micro-
amperes ~ 5 X 10~^ Amp:
dt = 47 microseconds —
47k 10^6 sec; and dv = 5
volts):
CpF = [(5x10-6)
(47 X 10-6)1/5
COUNT
INHifliT
I MNt
^ COUPITEH
I
iMPUt
U(y.
OiS^U/tY
0^
I^STAUT^ Ut ft 5U W€ M J NT J
fig. 1.
= (235 X 10-121/5 pF
^ 47 pF
So far, theory shows the
approach to be a workable
idea. To reduce this theory
to actual practice, the use
of the schematic shown in
Fig. 2 resulted in being able
to measure capacitance to
within ±5%, or ±1 pF,
whichever is greater, from
1 pF to 999999 pF (1.0
microfarad). Now those
unmarked capaeitors can
be accurately npeasured
and their value? displayed
digitally. , '
The Schematic
The key to the simplicity
of the capacitance meter is
the MK50395N six-decade
counter manufactured by
Mostek. This counter per-
forms the tasks of counting
up or down, is presettable,
has a compare register that
provides an equal output
when the counter contents
equal the register contents,
and also provides seven-
segment and BCD output
data. The list of features
continues, but those in-
terested can get the data
sheet by writing Mostek,
Box 169, Carrollton TX
75006.
The 1 MHz oscillator is
arranged using U1, CMOS
NAND gates, and is a Stan*
dard design. Since extreme
accuracy was not a require-
ment, no frequency trim-
ming or special crystal
tolerance is specified. This
should simplify and lessen
the expense of the com-
ponents. U2 provides the
control functions neces-
sary to operate the meter.
Linear amplifier A1 is a
dual bi-fet high input im-
pedance amplifier. A1 is
wired to drive a constant
current (adjustable by R4)
through the capacitor be-
ing measured. Amplifier A2
is used as a comparator so
that, when the output of A1
reaches a predetermined
voltage, A2 switches its
output from zero volts to
V+-. This action prevents
further counts from accu-
mulating in the MK50395
counter. The diodes from
digit strobe lines on the
counter feed preset
counter BCD inputs A and
D. This results in digit 6
down to digit 3 having a 9
preset into it. Digit 2 is
loaded with an 8, and digit
1 (LSD) is loaded with zero.
The BCD inputs have inter-
nal pull-down resistors, so
a zero will be loaded into
the unconnected BCD in-
put ports. More on this in
the calibration sequence.
A single-pole three-
position break-befo re-
make switch is used to pro-
vide the control sequence
for the unit. On the
schematic, position A is the
234
n
HI
120*
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Fig. 2. Note: Capacitors are silver mica un/ess otherwise specified. Resistor values are 70%, !^ Watt urrless otherwise
specified.
starting point. While in
position A, the counter is
being loaded with 99980.
Position B stores the
data in the counter dispiay
after a capacitor measure-
ment.
Position C initiates a
measurennent.
Upon returning to posi-
tion A, the value of the
capacitor nneasured will be
stored for display and the
counter preset for the next
measurement.
The unit utilizes leading
zero suppression, so, when
the counter contains all
zeros, the display will show
only one zero when turned
on.
Calibration
Calibration is ac-
complished in two steps:
high value and stray. 1 ,000
pF 5% silver mica or other
high-value close-tolerance
units may be used for the
initial setting. Since most
capacitors are ±20%
tolerance units, extreme
accuracy is not a require-
ment, and the silver mica
units will provide suffi*
cient accuracy if closer
tolerance units are not
available, 1,000 pF to
10,000 pF values are pre-
ferred for calibration.
Attach the known-value
capacitor to the input ter-
minals. Apply power, and
switch from A to C with
SW1. The display will read
some value. Adjust R43 un-
til 1,000 pF ± 15 pF is
shown. This completes
step one.
The next calibration se-
quence will zero out the
stray capacity. Adjust trim-
mer capacitor CI for
minimum capacity. With
no capacitor connected to
the unit, switch from A to
C. Some number will show
on the display (999992 on
test unit). This represents
the preset number loaded
into the counter plus the
stray capacity. This value
must be zeroed out, so
small capacitor values can
be measured. Zeroing the
stray is accomplished by
adjusting the trimmer CI
until the meter reads zero
when switching from A to
C.
Upon completion of
zeroing out the stray value,
return to the 1,000 pF
capacitor and readjust if
necessary to bring the unit
into calibration.
General
A digital display can pro-
duce some distracting
observations. As an exam-
ple, measuring a 5,000 pF
(.005 uF) capacitor may
produce a reading of 5040
pF one time and 4995 the
next time. Remember, even
though that appears to be a
large value, it represents a
±0.9% accuracy. Since
the majority of capacitors
are ±20%, this unit allows
measurement of those un-
marked capacitors suffi-
ciently accurate for most
applications.
Two last comments con-
cern the constant current
source. The accuracy of
this type of capacity meter
depends on the constant
current source. Improve-
ment in this area will im-
prove overall perfor-
mance. Secondly, any
capacitor that is 'leaky"
Will give a readiiig that is
not representative of its
true value.H
235
I
I
1
YD-044
Dynamic Mike
ADVANCED COMMUNICATION
EQUIPMENT
QTR-24
World Clock
f^^^irt*-^-««> s!ts=««s*|r*'
o
t
Vft
s
Left to right - FRG-7. Solid State Synthesized Communications Receiver • FR-101 Digital, Solid State Receiver • SP-101B,
Speaker • FR-101, Digital Solid State Receiver • FL-101. 100 W Transmitter • FL-2l00a. 1200 W PEP mput Unear Amplifier
Left to right — FT-620B, 6 Meter Transceiver • YP-150, Dummy Load Wattmeter * YO-101, Monitor Scope • FTV-250,
2 Meter Transverter • FTV 650, 6 Meter Tratieverter • FV-101B, Externa i VFO • FT-101F 1601 OM Transceiver
Left to right — YC-601, Digital Frequency Display • YC-355D, Frequency Counter • FP a01, AC Power Supply e FT-301S
Digital, All Solid State Transceiver • FV-301, External VFO m FT 225RD, 144-146 All Solid State All Mode Transceiver
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2M MOBILE TRANSCEIVEft. Svnthesfed PLL.
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ttabilrlv FET VFO.
TS-S20S
S799.0I]
SSe TRANSCEIVER. Proven m the shades of
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Superb eogineerifig aod styling.
SP-5Zfl $33.00
Optjonil e^cternal i{ieaker for better leadability.
TVSOZS S29I.00
TBANSVERTER. Puts you on 2M the easy way.
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^™ -INIROOUCING- ^^33°°
THE UiTUIATF tR RtCllVitt OESlfia. „THE KEIMOOll »«»
With due t^lMlH Uufl ftV triinv mttriMi m t i«n-|uMitf rtfipi*. T^
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ti^wis, iMUfeUiiv imn tpmum% otnimmmm ikn iP<r all
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TS-aSS HTBtniKihv. prdwidini rutt ir;wtqc«3ii frt4<iiic¥ mnati
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MCSO
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Dynamic microphone designed expressly for ama-
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LOCK flitch es, md a mtcrophone pSug. 1600 or
50k ohm}
COMMUNlCATJOliS RECEIVER. 1.S to 29J
MH2, WWV and CO bind. 50 MHz. 144 MH^ con-
verier optional. Stable VFO & oicHtator for S
frxed diatiaeEs. 1 KH^ dial readout, Xial fillers
jSSS'S pole. CW/B pole, AM/6 pole}. Squelch.
S meter. Noise blanker.
3^5990 SZLOO R B99D S499.0D T 5990 $49900
SSe TRANSMITTER. 3.5 to 29.7 MHr. Stable
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Xmision aval table. Butft-in AC pwr supply. Split
trequency control available.
SS
VFQB20
SI 75. 00
Designed eKcluBively for urn with TS'82fl. BIT
Circuit md control switch, FuHy compatible with
optional digital display^
VFOS20 (Not Shown) S143.00
Solid State Remote VFO, RIT circuit with LED
if^dicator.
SM^22Q
S149.00
R300
S279.0Q
KENWDOD'S SM-22Q STATION MONITOR. The
SMZZO'i unexcelled vwsatility atloiws you to
moi^itor your transmmions, monttnr incomiog
sifnals, and nwnitor the aniount and strength of
band airtivity* and performs as a genera Ipyrpose
to MHz osciltoscope, as well.
ALL BAND COMMUNICATIONS RECEFVER.
AC, batteries or exiernal DC. 170 KHi to 30 MHi
in 6 bar\ds. Foreign broadcasts or ham tidio in
AM, SSB and CW. Dual gate MDS/FET transistors
& double conwereon. &and spread diaL &0G KHz
marker.
CALL JIM TITUS FOR FREE QUOTES ON TOLL FREE NO. 800-523-8998
k
y
DIVISION OF TREVOSE ELECTRONICS
4033 Brownsville Rd • Trevose, Pa. 19047
IW^uTSWMSiMMSmM^MXTm
DRAKE
®
KNOWN FOR QUALITY
THROUGHOUT THE WORLD
RECEIVERS
DSR'2
4NB
VLF'HF Digitat Synthesized SSB,
AM,CWJSB,RTTY
C'Une. HF.160 10M
Noise Blanker for R 4C
TRANSMITTER
T4XC
C-Line.HFjeO 10M
TRANSCEIVERS
LINEAR AMPLIFIER
L4B
Linear and w/power supply & tubes
MATCHING NETWORKS
$3200.00
$699.00
$74.00
$699.00
TR-7
Transceiver
$1100,00
DR7
Digital Readout
$195.00
RV7
Remote VFO for TR7
$195.00
FA-7
Fan for TR-7
S25.00
MS7
Speaker tor TR-7
$33.00
7077
Dynamic Desk Mike for
TR7
$45.00
34PNB
Plug-in Noise Blanker forTR-4 Series
$100.00
$995;00
MN4C
Antenna Matchlitfl Network. 200W
$165.00
MN'2000
Antenna Matching Network. 1000W
$a50.00
W-4
RF Wattmeter, 1J to 54 MHz
$79.00
WV'4
RF Wattmeter, 20 to 200 MHz
$89.00
7073
Hand-Held Microphone
$19.00
7075
Etesk Top Microphone
$45.00
1525EM
Push-button Encoding Microphone
$49.95
HS1
Head Phones
$10.00
AA10
low, 2M Amplifier
S49,95
TV300HP
300 ohm High Pass TV Set Filter
$10.60
TV75-HP
75 ohm High Pass TV Set Filter
$13.25
TV42-LP
Transmitter Low Pass Filter. 100W
$14.60
TV 3300- LP
Transmitter Low Pass Filter. 1000W
$26.60
TV 5200- LP
Transmitter Low Pass Filter 1000W.
100W,6M
$26.60
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COLLINS AMATEUR EQUIPMENT
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KWM ZA TRANSCEIVER $353300
Unmatched for mobile and fixed station applications. 175W
on SSB, 160W on CW. Switch select up to 14 optional Xtals.
Can be used for RTTY. Filter type SSB generation. Automatic
load control. Inverse RF feedback. Reimeability-tuned vari^le
oscillator.
75S-3C RECEIVER $3000.00
Sharp selectivity. SSB, CW and RTTY. Single control rejection
tuning. Variable BFO. Optional mechanical filters for CW,
RTTY and AM. 2.1 KHz mechanical filter. Zener regulated
oscillators. 3-position AGO.
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32S-3A TRANSMITTER
$3250.00
Covers all ham bands between 3.4 MHz and 30 MHz. Nominal output of 100 W. 175 W, SSB and 160 W
CW. Dual conversion. Automatic load control. RF inverse feedback. CW spotting control. Collins
mectianical filter.
319B-3 SPEAKER
$95.00
W 312B-4
SPEAKER CONSOLE
$648.00
313B-5 VFO CONSOLE
$1616.00
o
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516F-S AC POWER SUPPLY
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302C-3 DfRECTIONAL WATT METER
$493.00
DL-1 DUMMY LOAD
$370.00
CALL JIM TITUS FOR FREE QUOTES ON TOLL FREE IMO. 800-523-8998
i
id
DIVISION OF TREVOSE ELECTRONICS
4033 Brownsville Rd • Trevose, Pa, 19047
/OH C\
A Mf\i\ ii*\'% C\
conn
I
I
o
M
mRB THRULINE® WATTMETER
• BUY ONLY THE ELEMENTS YOU NEED
AND ADD EXTRA RANGES AT ANY TIME
• READ RF WATTS DIRECTLY
Table 1
STANDARD
ELEMENTS
MODEL 43
FrrquervcY Bands
1MH£)
r&^tr
Rjn|r
1-
25-
50-
lOO-
200-
400>
W
M
125
250
soo
TOOO
S watts
J
5A
5B
sc
5D
5£
1Q watts
—
IDA
lOB
IOC
1DD
10E
25 watts
2SA
25B
25C
2SD
2SE
SOwait^
50H
50A
SOB
50C
50D
50E
100 wait*
100H
100A
100B
100C
tOOD
lOOE
2S0watt^
250H
250A
250B
2S0C
2500
250E
SOOwdtts
500H
500A
MOS
5Q0C
500O
sooe
TOiO watts
lOOOH
lOOOA
10006
1000C
10000
toooc
2500 watts
2S00H
5000 watts
SOOOH
Table 2
low-
POWER
ELEMENTS
1W4lt
tjt. No.
TS watts
Cat, No.
fX^m hAHi
060-1
60-80 MHz
060-2
80-95 MHj
OQO-1
flO-95 MH7
080^2
9S-125 MHi
095-1
95-150 MHz
095-2
nO-160MHr
110-1
150-250 MHj
150-2
150-250 MHt
1S0-1
TOO-JOOMHi
200-2
200^300 MHz
200-1
25fr450 MHz
250-2
275*450 MHz
275-1
400-850 MHi
400^2
435-650 MHz
425-1
BCX)-950 MHl
800^2
800-950 MHz
aoo-T
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ATLAS
21 OX
21 5X
220CS
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Deluxe Mtg. Kit for 210X
&215X
AC Console for 21 OX &
21 5X
Transceiver. SSB. Solid
State.
10-1 60M. 350W.
765.00
765.00
55.00
155.00
1195.00
DD6XL
305
311
350-PS
DMKXL
Digital Dial Readout for
350-XL
Plug-In Auxiliary VFO.
For 350-XL
Plug-In Auxiliary Crystal
Oscillator for 350XL
AC Pwr Supply w/Spi(r &
Phone Jack for 350-XL
Mobile Mounting
Bracket for 350-XL. Easy
Piug-ln
229.00
1 55.00
135.00
229.00
65.00
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NYE VIKfNG
No. 114-310-003 $9.65 No. 114-310-004GP $50.00 No. 114-404-002 $20.7S
No. SSK-1 $23.95
No. 250-46-1 $36.50
No. 250-46-3 $46.50
No. 250-20-1 $19.95
No. MB2-1 $315
NPC
2.5 AMP
4 AMP
6 AMP
f y ■■
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103R 39.95
104R 43.95
12 AMP
108 RM
$104.95
25 AlVIP
109R 159.95
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VIBROPLEX
H
"PRESENTATION"
72.50
ORIGINAL"
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n
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VIBRO-KEYER
46.50
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DIVISION OF TREVOSE ELECTRONICS
4033 Brownsville Rd • Trevose, Pa. 19047
/#i-i
t%e^ '«jiAA//i-«c\ ^c^ cf^nfs
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"DenEm- The MT-3000A
SPECIFICATIONS:
•Power handling capabHIly In excess
of 3 KW PEP
•Front Panel Antenna Switch with 5
Antenna Inputs ptus Tuner bypass posi-
tion
*Bjill-in 50 Ohm— 250 Watt dummy load
•Dual Wattmeters
•Compact: 5%" x 14" x 14'\ 18 pounds
•Continuous Tuning 160-10 meters
♦3 Core Heavy-Duty Balun
M9*S0
. .^.•^-iiffifi^^!^-
Denlfon-
Super
Tuner
160-10 Meters
Balanced Line,
Coax, Random
or Long Wire
Maximum Power Transfer, Xmitter to Antenna.
T KW Model $1 29.50 3 KW Model $229.50
If they copy the quaUtyt they
eanH meet the price.
The original DfinTron Super Tuner. The
original Super Tun-er. The original MT-
30O0A. And nov,' DenTron brings you the
original MT-2000Af an economical, fufl-
pow^r tunei" designed to handle virtually
any type of antenna.
The sleek styling and low profile of the
MT 2000A is beautiful, but be assured ttiat
Is only a part of the excitement you'll
derive from the MT-2000A, The MT.2000A
is designed and engineered using heavy-
duty all-metal cabinetry, and high quality
American components throughout.
When you consider the MT 2000A^s unique features: 5 V/"Hx 14"D?( 14"W, front
panel coax bypass swHching, fror\t panel lightning protection antenna ground-
ing switch, 3KW PEP, and the ability to match coax, random wire and balanced
feedline^ we're sure you'll decide to buy an American original and stay with Den-
MT-ZOOOA $199.50
Denfforu
The evolution of
the MLA
When the MLJ^-2&00 was first Introduced it was a new concept In high perfor-
mance amplifiers. Low and sleek yet powerful enough for the military. Some
wondered , . , needlessly.
A promise kept.
The M1_A-Z500 promised 20O0 watts PEP Input on SSB. A heavy duty power
supply. Two Etmac 8875' s. And as thousands of Amateurs across the world have
proven ^ the MLA-2500 delivers E
Now DenTron is pleased to bring you The new MLA-25CM1B^ Inherently the
same as the original MLA'250Qr the B model includes all of the above specif ica-
t Ions plus a few refinements. New high-low power switching tor consistent effi-
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Tested and proven.
What better test for ah amplifier than the Ctlpperton DXpedltlon? Even after
32,000 OSO's, and an accidental dun K In the ocean, the same 3 MLA-2500's are
still amplifying other rare DXpeditions around the world— listen for them.
Convinced? Isn't It tlmeyou owned the ampilller that powered Cltpperton and
thousands upon thousands of radio stations throughout the world?
MLA-2500B $899.50
Denffon^
Big Dummy
w/eoolant
$29.50
All Band
Doublet
Ttiii All Band Doubltt or mvartHd Typff
A(M*niii OQttti 160 fhru tO meXtn, Hn
tatal itrigih 4rl 130 ftm 114 qa. ittm-\dt6
copFHrh iifhaud^l ^^ "W be (nidc ih^rttr
if rHciiFtrv Thit tuntd Pfjutlit ■* aniil-
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cavtrad belaficed Irantmiiiion llna. Tht
Aaiembly ii comjilttt. Add r^pa ia ih«
fln<fi «Ki py(l MP into pfliitian, Turt*
Mih ih. D4^TrQ«i SutMT Tun.r «id
you'r* OA 10 thrQu^hi 1^ n»tifT wktti
Ddv Antannsl Kdw juit lor the DvnTron
All Band Ooubiet.
524 '50
JR. MONITOR™
Antenna Tuner
Continuous tuning from
1.8-30 MHz. 3O0 watt power
capability. Forward reading
relative output power meter
— simply tune JR. MONh
TORTw controls for max-
imum RF output on the
meter. Built-in ba!un. Mobile
mounting bracket, Ceramic
rotary 12-posEtlon switch.
Cap acltor spacing 1000 volts.
Tapped toroid inductor.
Antenna inputs: coax un-
balanced SO 239, random
wire* balanced feed line
75-660 ohm. Weight: 2Vi
pounds.
S 79.50
'DerHfon. W-2 PAD
INLINE WATTMASTER
Kead forward
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^■■■■i--i. .
Tired of consunt switching and guasiwork?
Every serious ham knows he musT read tK>th lofw^rtf and ravtsne watxagp umuttansaui^v
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599.50
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HSIF
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TRITON IV
EQUIPMENT
MODEL 940 Si 10.00
ONE • SIXTY CONVERTER
MODEL S49 SI 79.00
REMOTE VFO
TRANSCEIVERS
MODEL 540-SOOW, SSB/CW
3.5 - 30 MHi $699.00
MODEL 544- DIGITAL, SOOW
SSR/CW, 3.S • 30 MHz
$869.00
MODEL 344 $197.00
DIGITAL READ OUT/COUNTER
MODEL 262-M $145.00
DELUXE POWER SUPPLY
ARGONAUT
MODEL S09 $369.00
SW, SSB/CW, 3.5 -30 MHx
AMMETER
307 $14.00
XTAL CALIBRATOR
206-A $29.00
LINEAR AMPLIFIER
MODEL 405 $159.00
100W, 3.5-30 MHz
KEYERS
ELEaRONIC KR-50
$110.00
ELECTRONIC
KR30-A
S69.50
8
ELEaRONIC KR-5A
$39.50
KR-2A
817.00
KM -A
$35.00
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y
DIVISION OF TREVOSE ELECTRONICS
4033 Brownsville Rd • Trevose, Pa. 19047
I
I
ICOM
VHF/UHF AMATEUR
& MARINE EQUIPMENT
VHF/UHF AMATEUR
8(IVIAR(I\IE EQUIPMENT
10245, SSB 146 IVIH^ FM 10W x
CVR. LSI synthesizer with 4 digit
LEO readout. Xmii & Rev frequencies
independently programmable. 60 dB
spur to us attenuation* **- ji f- a a
$545.00
1C245SSB. $689.95
IC215. 2 METER FM PORTABLE,
Three narrow fillers for superb perform-
ance. 3W or 400 mW. 15 CH. capacity,
MOS FET RF Amp & 5 luned ckts,
S-Tneier front panel
$265.00
$239.00
IC-5Q2. 6 METER SSB h CW PORTA-
BLE XCVR. Includes anlenna& battery
pack. 3W PEP & stabie VFO for tun &
FB QSO's. Cr>weft first 800 KHz of 6M
band, where nrost acliuity is.
$1650.00
\C-2U
IC-21K 4 MEG, MULTI-MODE 2M
XCVR. 144-145 MHz an SSB & CW,
plu? 148^147 MHz on FM. Work AMAT
OSCAR SIX or seven, LSI synthesizer
wah 1 digit LEO, MOS FET RF Amp,
5 helical cavities, FET mixer S 3 LF,
filters.
$850.00
IC701 W/POWER SUPPLY & MIKE • Dual Independent UFO's Built-in • 100
Watts Output • All HF Bands, IBO-IOM • Fully Synthesized Tuning •
Continuously Variable Bandwidth • Double Balanced Schottky Diode 1st Mixers
RF Speech Processor • VOX; Fastbreak in CW; RIT; AGC; Noise Blanker; Full
Metering •
IC280
%ttt--**
$480.00
IC-21A. 146 MHz FM TOW XCVR. MOS
FET RF Arrrp h 5 helical resonator
filter, plus 3 LF. filters. IOC modulation
cor\trol Variable output pwr: 500 MW
to 10VV Front panel discrimmator meter,
SWR bridge. 117 VAC and 13 6 VDC
pwr supplies, $399.00
DV21. DIGITAL VFO. Use with IC-
21 A to complete 2M band,
$299.00
IC202. 2 METER SSB
PORTABLE XCVR. Puts
sideband in your hand*
(fiternal C batteries or ex-
ternal ! 2 VOC. 3WPEP,
True l,F. norse blanker.
144,0, 144.2on twoottier
200 iCNz bands.selectable.
Hamtronics stocks 145.2
aad14S.3 146.0 MH2 for
calling frequency & satel-
lite band
$275.00
IC'30A, 450 MHz FM LOW XCVR, W
or 10W- Low noJse MOSFET RF Amp
& 5 section helical filter, 22 CH.
capacity, S-meter & refative power out-
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$440.00
CALL JIM TITUS FOR FREE QUOTES ON TOLL FREE NO. 800-523-8998
I
I
TRANSCEIVERS
Stngie-Sideband Transceiver
350B S649.95
350D
$749.95
Full 300 Watts PEP input on singJe-sideband • Selectable
80 or 100 Hz CW audio filter • Built-in AC power supply •
Built-in 25 kHz crystal calibrator for model 350A • Meets or
exceeds alt FCC specifications for purity of emissions.
Model 3500 has lb e same 3pecifica!ions and ch a racf eristics as the Mod€f 350A
except the unit comes with a built-in digital trequency display with readout to
100 Hz as standard &qu(pment.
HF700S
HF700S/SS16B
$699.95
$799.95
POWER SUPPLIES
Precision power supplies provide all input required by Swan
transceivers. DC converters adapt the AC power supplies for
mobile or portable use to a standard 12 V automobile battery
• Power supplies are Ideal for temporary operation, such as
vacations, short trips, remote installations and emergen-
cies • Swan power supplies are designed for long reliable
service.
PSU-3 Universal Power Supply • 1 15/230 VAC • Buift in
Speaker $175.95
117 X AC Economical AC Power Supply w/out cabinet or
speaker $129.95
ACCESSORIES
510X 10 Channel Crystal Controlled Oscillator $69.95
VX-2 Plug in VOX • $49.95
FP 4 Phone Patch _ , $69.95
SS1 6B 1 8 Poll Filter Kit $99.95
METERS
WM6200
FS-2
SWR-3
SWR'IA
FS1
WFyiisoo
WM2000A
In-line Precision Wattmeter for 2M. 2
Scales to 200 W. Reads SWR .... $87.95
SWR Sr Field Strength Meter $19.95
Pocket SWR Meter , . . . $1 4.95
Relative Power Meter & SWR Bridge $29.95
Pocket Field Strength Meter $1 3.95
In-line Wattmeter. 4 Scales to 1500W. 2 to
50 M Hz $74.95
Peak Reading SWR Wattmeter 589,95
NEW!
100 MX Mobile Transcaiver
The 100 MX Mobile Transceiver is completely solid state and
incorporates state-of-the-art design and styling.
The recerver sensitivity is better than 0,35 uv at 50 ohms for
10 db signal plus noise-to-nolse ratio for all bands. Audio
output is four watts into four ohm load. Audio bandpass
response is 300 to 3000 Hertz. Provisions for an external
speaker or headphones are on the rear panel and a gimbal-
type mobile mount is included as standard equipment.
o
90
VI
CALL JIM TITUS FOR FREE QUOTES OIM TOLL FREE NO. 800-523-8998
M
DIVISION OF TREVOSE ELECTRONICS
4033 Brownsville Rd • Trevose, Pa. 19047
rirs in vc 12* Ji r r iTiti ip^ irti
W2KSD/1
NEVER SAY DIE
ec/ztor/aA t>y Wayne Green
from page 113
these days, having proven his
theories rather spectacularly.
Spots mean better DX, so the
DX brethren are up to here in
countries. They can't stop wor-
rying about WARC and the
coming 1979 ITU plenipoten-
tiary conference which has the
power to completely delete alJ
amateur frequency allocations.
Where we actually stand as
far as gaining, holding, or los-
ing frequencies goes is more of
a matter of belief than one of
certainty, since no one can
know for sure which way the
critical African 44-vote black
b)oc will go. That's the bunch
which wiped out our 237,000
MHz of satellite microwave
channels in 1971. Oddly
enough, time has not seemed
to increase their enthusiasm
for giving up what they con-
sider their frequencies for a
white man's hobby.
The ARRL complacency Is
reassuring to many amateurs.
A reading of the report In QST
of what happened in 1971 when
the ARRL went to the ITU at
Geneva to preserve our ham
satellite frequencies and lost
virtually everything might
dispell some of that com-
placency. Well, since it is now
far too tate to do anything
about it, why fret more. Let's
just wall and see. ff we come
out okay, we saved a lot of
needless worry. If we lose our
shirts, then we can indulge in
an orgy of recriminations. I'm
not sure how the League will
work things around to put the
biame on me, but they man-
aged it with 'Incentive Ticens-
ing,*' so I have a profound
respect for their ability to
rewrite history and get gullible
amateurs to buy it.
Rather than spend a lot of
time on WARC, I see the ARRL
tied up with a whole rash of pet-
ty squabbling. Their persecu-
tion of Mary Lewis and their
dedication to preventing her
from being the first woman
ARRL director has resulted in a
lawsuit. Their insurance
scheme has come a cropper
and must betaking a lot of time
to hassle. Then there \s a suit
pending with Al Ogden, chal-
lenging the ARRL to put up or
shut up on keeping Techni-
cians from holding office in the
League, The ARRL Foundation
mess is coming apart, despite
heroic efforts to cover up the
situation . . . which is tied in
with the almost total inaction
on solving the real WARC prob-
lems.
Recent efforts to try to scut-
tle the Canadian Amateur
Radio Federation have been ty-
ing up many HQ staffers. CARF
seems to be weathering the
battle rather well and we see
more and more Canadians
resisting the carpetbaggers
from south of their border. They
still have time to harass hams
who write In with a beef. One re-
cent sample was Terry Staudt^
who wrote to Baldwin with a
complaint and for his trouble
found Baldwin trying to get him
fired rather than answer his
complaints,
ARMA (the Amateur Radio
Manufacturer's Association)
members got uptight over the
ARRL Code of Ethics. They
didn't object to the concept, on-
ly the jamming of it down their
throats. They called Baldwin on
the carpet and demanded some
explanation for the QST
editorial claiming heavy in-
dustry support for the scheme.
Baldwin, according to the in-
dustry people Tve talked with,
came out a liar in their estima-
tion. He was totally unable to
back up his editorial with facts.
The industry is further very
upset over the new ARRL push
to set the prices to be charged
for ham gear and to force
manufacturers to have a sam-
ple unit tested in the ARRL labs
before it can be advertised in
QST. It*s the arrogance that
really gets to the industry peo-
ple.
If the League would spend a
fraction of the time they invest
in petty harassing of hams who
are critical of them and in mak-
ing life difficult for the industry,
they would have plenty of time
to attend to the more important
matters such as WARC, and I
don't mean the relatively in-
significant WARC meetings in
Washington. The votes of the
other 153 countries are going to
determine what amateur radio
is like in the 80s, not what hap-
pens in Washington.
ARMA members were as-
tounded when Noel Eaton
(ARRL-IARU) reported to them
in Atlanta this year that nothing
whatever had been done or was
in prospect to approach the
44-vote African black bloc to try
to get their support for amateur
radio at WARC. It appears that
the whole future of amateur
radio is being left entirely to
chance. Good iuck.
ARRL BUSINESS
!f the ARRL isn't busy trying
to cope with the WARC situa-
tion, then what are they doing
. . . besides trying to cut ex-
penses by firing people? Oh,
they're busy with a multitude of
problems , . . such as the in-
surance program which seems
to be giving them more and
more troubles. They may really
be in the soup on that one. Then
there is the project to try to stop
Mary Lewis from getting to be
the first woman ARRL director
. . . this seems to be getting into
court. The incumbent, Thurs-
ton, has been a terrific yes-
man, so he would be a serious
loss to HQ, particularly since
Mary Is the kind of person who
does not knuckle under easily
. . . as they've found. Another
big time waster is the HQ battEe
to prevent a Technician class
ham from getting elected as a
vice director. Al Ogden, a
Technician, is challenging this
bias In a court case. Then there
is Terry Staudt, a ham who had
the gall to write Baldwin with a
beef and who, for his trouble,
found the League trying to get
his employers to fire him 1 And,
despite monumental efforts to
cover it up, the mess with the
ARRL Foundation just won't
die. Ask your director about
some of these Incidents the
next time he comes to your ciub
, , . and let me know what he
says.
With ARMA in disarray after
their African plan was de-
stroyed, the League is back to
business as usuaL ARMA has
been trying to come up with
some ideas on other things
they might do which would at-
tract members, such as work-
ing up a ham industry exhibit
for use at trade shows, but this
seems to be leaving the smaller
firms cold since they wou Id get
little benefit from it. ARMA,
having no paid staff, has to de-
pend on volunteer time from in*
dustry people* In general, this
is in very short supply, for most
industry leaders are already
spread thin trying to keep up
with their own work. The lack of
any significant benefits to
firms supporting ARMA has
kept down paid memberships,
thus making it impossible to
have a paid staff. Until ARMA
comes up with a convincing
goal which will benefit the en-
tire industry, it is going to have
tough sledding and be a sitting
duck for ARRL pot^shotting.
COWAN PROMISES
On page 1 of the October,
1976, issue of CQ, Dick Cowan
said, ". . .CO has slipped badly
In both circulation and adver-
tising." He went on to say that
this had happened because he
was preoccupied with SB and
other more profitable publish-
ing ventures. He points out that
"it would be very expensive and
time-consuming to rebuiSd it/*
Next he says he has the money,
the manpower, and the know-
how to rebuild OQ, and, by God,
he intends to do just that.
Okay, here we are two years
down the pike. All that money,
manpower, and know-how have
resulted in a magazine that is
hardly different from two years
ago, running about six or eight
articles an issue (like Ham
Radio Horizons). There has
been no noticeable change ex-
cept for a slight increase in
advertising, and that is due
primarily to the yeoman efforts
of Jack Gutzeit.
Far from being first, as prom-
ised, CQ is running neck and
neck with Ham Radio Horizons
for last place . . . getting ads
out of sympathy more than per-
formance. This sympathy can
be costly. One advertiser com-
plained to me that he had run
an ad and been incredulous at
the reader service response. He
was had J he felt, for sending
out catalogs costing him nearly
$1,000 and the results were vir-
tually nil. Would he re-run his
ad for half price? No way!
The secret to having a good
magazine is no secret at all.
You pay authors well and you
pay them promptly, not after
they have to sue you for pay-
ment. This will bring you the
cream of the crop. It will also
bring you plenty of readers who
will respond by buying from
your advertisers. You really
have to share the money with
the authors, not take it all and
put it into trains and yachts.
There is no real secret to put-
ting out a good magazine and
getting hams to read it. You
have to give good value ... in-
teresting articles and lots of
'em. To get these, you must pay
money . . . funny how a quick
check for an article seems to
motivate people.
EXCITING THE FCC
The Tatest catalog from Hen-
shawls, 7622 Wornall, Kansas
Cpty MO 64114, should get
some people at the FCC in an
uproar. They have three stores,
the others in Independence and
Ft. Worth, and they are not ham
stores. The catalog is strictiy
CB, but with two items marked
as being for amateurs. These
are Items you won't find in a
ham store catalog. There on the
back cover you'll find an ad for
an "amateur" GW transmitter.
It says, "Illegal to modify for
use as a CB linear.'' This gem Is
a 125-Watt CB linear disguised
as a 10m ham transmitter. As
long as I see ads like that right
out in front of the CBers, I have
246
The LEADER In the Northwest !
ATLAS • ICOM • KENWOOD • YAESU
Come to ABC Communications today for the best solution to your
particular communication requirements, whether they be Amateur,
Two-way Business Band, VHF Marine or Police Scanner.
ATLAS Transceiver 21 OX
80 thru 10M
ATLAS Transceiver 215X (not shown)
160 thru 15M
DENTRON MT-3000A
Deluxe Tuner
DENTRON 160-10 AT (not shown)
Super Tuner
KENWOOD Transceiver
TS-820S 160 thru 10M
KENWOOD Transceiver
TS 520S 160 thru 10M
KENWOOD 2M FM
TR-7400A
NfiTIONWIDE TOLL FREE MCIMBER
1 ■800-426-6937
Washington state: 1-800-56Z-7625
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SSB1C211
ICOM Transceiver 2M FM
10 245
YAESU 901 DM
We also handle WUson, Cushcraft^ Hy-Qaln, Antenna
Spedallsts, KLM^ etc.
Attention Wasiifngton residents: Come on in for ex-
ce^Eent service m our complete CommunJcattons Repair
Shop,
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Trt'Ex, Rohn, Wilson Towers. Shipping Info: F,0,B. Seattle
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Washington residenls add sales tax.
YAESU HP SSB 160 thru 10M
FTIOIForFE
COMMUNICATIONS
i^A46
17BS0 T5TH AVE N.E. • SEATTLE. WASH. OSlftS • <2(J6] 3M^3D0
iTiitSlfir CNfif^t
VJSA
Other locations: (Walk-in customers only) ♦ Bellevue - 12001 N. E. 12th • Everett - 4610 Evergreen Way • Open Mon. thru Sat,
p^ R&sder Servfce — see psge 323,
247
no confidence that the FCC has
any Intention of making their
CB and ham linear rules stick.
Oh, ham dealers seifing ampli-
fiers which cover 10m to hams
will get ihe full treatment from
the FCC, but CB dealers selling
CB linears under the most
transparent of covers will be ig-
nored by the FCC.
The other gem from Hen-
shaw's is a 10,5-GH2 police
radar jammer which is called an
*'amateur transmitter." The ad
goes on to say that, "This may
be illegal to use as a police
radar jammer." This $400
gadget can be set to Indicate
speeds of 20, 30, 40, 55, or 60
mph on police radar. Here we
go again!
SPEAKING OF 10.5 GHZ
When Microwave Associates
came out with their cute little
10 GHz units a couple of years
ago, I got quite interested and
urged our then editor to get a
couple and play with them. He
did and wrote them up, but
didn't ever otter to let me in on
the fun. Then, when he left, the
10 GHz stuff left with him. so I
rrstssed out completely.
Weli, almost completely.
Chuck WA1KPS of Tufts Elec-
tronics recently got a pair of the
units and added the i4 strips
which turn them into trans-
ceivers. Since I have one of the
more accessible mountains
just up the street (actually, the
mountain had a lot to do with
my picking this location when
we moved up here 16 years
ago), Chuck got one of the
transceiver units into my hands
for some tests. The first test
was between Pack Monadnock
(NH) and Blue Hill (MA).
I had it easy, having only to
pack the 10 GHz rig and a cou-
ple of HTs in the 73 van and
head up the road. The road
goes right to the very top, I then
climbed up into the fire tower
and set up my system, coor-
dinating it on 223.5 MHz
simplex. Chuck had a more dif-
ficult time, having to carry
everything up from a parking lot
to the top of his mountain, a
20*minute hike. It was worth the
trouble, for the signals came
through full quieting over the
58-mile path.
All is not beer and skittles for
the pioneer, I forgot to bring
gloves and the wind was icy
cold up there In the framework
of the fire tower, so 1 about got
frostbite. It was worth it once
we got the two rigs tuned to
each other; This Is no simple
matter when your hands are
cold and the wind is blowing
you around.
As I was driving back down
the mountain, fired with the en-
thusiasm of success, I got to
thinking about Pack Monad-
nock, I've spent many a night
on that mountain working far-
off repeaters . . . particularly
back about ten years ago when
there weren't so many of them.
From that location I had no
probl<em working repeaters in
Maine, Vermont, Massachu-
setts, and even down into Con-
necticut, i couldn't quite make
any Rhode Island repeaters ex-
cept under belter than average
conditions. Why not see what
DX we could work on 10.5 GHz?
Chuck is a sucker for any-
thing to do with amateur radio^
so a few days iater he was tak-
ing a day off from the store and
heading for Mt. Ascutney in
Vermont (they have a splendid
76 repeater on Ascutney).
Again I pooped on up the Pack
and coordinated via first 2m,
then 223.5 MHz until we made
the contact on 10.51 Again
Chuck had quite a hike to the
top, carrying the 10,5 rig plus
his HTs. It was even colder than
the previous contact and it took
about 15 minutes before we
finally got everything tuned up
right and had full quieting
clean signals. We were afraid
for a while that we might not
make it. The distance was only
52 miles, but it was over some
very rough terrain.
Well, the day was still early,
so why not drive on over to
Maine and up to the top of Mt.
Agamenticus, near Ogunquit,
Chuck climbed back down
Ascutney, packed everything in
his van, and drove clear across
New Hampshire and to the top
of Agamenticus, This was a
6d.5-mile hop, so it would be
stretching the ability of the tiny
rigs. We were using them bare*
foot, with only the little horn
antenna which Microwave
Associates furnishes.
By late afternoon, Chuck was
on top of Agamenticus and I
was back up on the fire lower
on the Pack, listening carefully
and aiming the rig at where I
thought his mountain should
be. Once Chuck heard me call-
ing and tuned me in, t was able
to aim the rig a bit better and
peak the signals to perhaps an
S*7. Hmmm, that made three
states on 10.5 GHz, Not a
record, but not bad.
A couple days later. Chuck
was off to Rhode Island for
another try. This time we were
looking at a 69*mile path, but
with some formidable moun-
tains right along the route.
Chuck first had to get permis-
sion to climb the tower on the
hill (there are no mountains in
Rhode Island). This turned out
to be a production in itself.
Then, when he got there, he had
to climb the hill, which took on
the proportions of a mountain.
Next he had to climb Ihe ce-
ment base of one leg of the
tower and work his way up the
tower framework until he got to
the ladder at the 20- foot leveL
From there it was a bit easier.
climbing the wet and very cold
tower in the wind, holding on to
the fig with one hand, pockets
bulging with the HTs, and hold^
ing on very, very tight with the
other all the way up to the
150-foot level.
While Chuck was trying to
aim the rig and not fall off the
tower, his fingers gradually
freezing in spite of his gloves, I
was getting cold clear through
up on the Pack. I was. as usual.
Inadequately dressed and with-
out gloves. The wind was cold
and brisk, and the entire top of
ihe mountain was engulfed in a
thick cloud. We tried to get
through, but even the 223,5 HTs
were not doing very well. We
were doomed by the clouds, if
not by anything else. Those
10.5 GHz signals drop dead in
clouds or even In rain, so we
really didn't expect to make it.
Wedidn*t.
Chuck has been going over
the maps looking for a hill in
Connecticut which might have
a good iine-of-sight path to the
Pack. The fire warden on the
Pack says you can see Ragged
Mountain in Connecticut on a
clear day, so perhaps weMI
make it.
Oddly enough, we had not yet
worked New Hampshire, so one
recent Sunday Chuck packed
everything into his van and
headed up here. After visiting
the Pack to see how visible
some of the mountains were up
north, he headed for Mt. Wash-
ington. There was no time to
lose since the road to the top
would be closing the next day
for the winter. The auto-road
people warned that the top of
the mountain was in a cloud
with 250-foot visibility. Well,
perhaps it would blow off and
we'd make It,
After allowing Chuck enough
time to reach Mt- Washington
(6,288 feet, the highest point In
New England), I called him on
the Mt. Washington repeater on
67. He was stuck at the base,
wattmg out a long line of cars
waiting to pay the $7,50 toll. I'd
had to wait almost a half hour
to get up the Pack, this being a
Sunday at the peak of the fall
foliage.
Eventually, he got through
the toll gate and made it to the
top of the mountain. It was still
socked in, so 1 had little hope
for a contact. We had mea-
sured the path on the map and
it was 106 miles, which seemed
a lot for the tiny rigs. We set up
anyway, with me in gloves and
a heavy Jacket for a change. I
was only braving temperatures
In the 40s, while Chuck had 15 '
and a 40 mph wind. We tried to
gel through until frostbite
started to set in on Washing*
ton. The top of the mountain
was teed over with rime ice and
the clouds were still heavy.
After the three and a half hour
drive, a half hour wait In line,
and the long drive to the top,
plus the fact that this would be
the last chance to try the path
until next summer, Chuck was
not about to give up without
one more try. He set up in the
parking lot, maybe a couple
hundred feet down from the
top, and we worked at it. The
clouds parted for a moment
and there it was , . . "W2NSD,
this is WA1KPS," 1 acknowl-
edged it and we had a contact,
lt*s funny, but you can hear
your own voice coming through
the system when you have a
contact. This was a weak one
and didn't last but a couple of
minutes before the clouds were
in again and it was lost. I could
always teil Just how well Chuck
was tuning in my signal by how
clearly I could hear my voice
coming back.
Next spring, when we see a
particularly clear day In pros-
pect, perhaps we will again
head for the mountains. I
measure 1 50 miles between Mt,
Grey lock in Massachusetts and
Mt. Washington. Til bet we can
make it. In the meanwhile, you
can be sure that we'll be work-
ing on Connecticut and Rhode
Island. The very eastern edge of
New York might just be reach-
able, too. Who's worked seven
stales on 10.5 GHz?
SOME NEVER LEARN
DEPARTMENT
While on the one hand many
amateurs are trying to get the
FCC to live up to its promise to
deregulate amateur radio, on
the other a few amateurs are
trying to tie us up again with
more rules. I seriously doubt If
any of the amateurs who went
through the FCC repeater rules
screw-up are in any way in-
volved with the present move to
try again for repeater regula-
tion by the Commission.
The sooner amateur groups
stop trying to solve their prob-
lems by getting more rules from
the FCC and tackle their prob-
lems directly, the more we will
be in control of our future. What
amateurs who are pushing for
more regulations are saying is
that they don't want to either
take the time or make the eftort
it requires to solve their prob-
lems.
Yes, I am all too familiar with
the repeater situation where
any amateur can set up a re-
peater and mess things up for
hundreds of others. I also know
there are some reasonable
solutions to this problem for
those who tackle the situation
with determination.
The first step is for the local
repeater counci I to decide what
has to be done. If there is an u n-
coordinated repeater in the
area, get the other repeater
Continaed an psge 254
248
CALL TOLL FREE
I I
Communications Center
443 N 48ih Street
Lincoln. Nebraska 68504
tn Nebraska Call (402)466-8402
^058
I I
Communications Center
West
1072 N,Rancho Drive
Las Vegas. Nevada 89 106
In Nevada Call (702)647-3114
18HT
master cnarge
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ra*»
miSHP
RtNGO
RANGER
4BTV
We carry aU major brands of ham radios
AT DISCOUNT PRICES
Yaesu
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(<'' Readar Service — see page 323,
249
James ^yma WA7DPX
SIS W. JOih Sl
Casa Grande AZSS222
Fail-Safe
protecting repeater batteries
Most repeater owners
want to have a bat-
tery on the repeater so that
the system will continue to
function during a power
failure. But the problem is,
how do you keep the bat-
tery charged up so it will
work when you need it?
The following circuit
came about as the result of
a need for a battery charg-
ing circuit for our 371.97
repeater in Casa Grande,
Arizona. The following
capabilities were needed
on the charger:
1. Normal charging —
turn charger on at approx*
imately 12.5 V and off at
approximately 15 V.
2. Low-voltage fail-
safe in the event of charger
failure, approximately 11.5
3. Overvoltage fail-safe
in the event of malfunction
in charger turn-off sensing,
approximately 15.5 V.
4. Battery connected
to 110 V ac line only during
charging period-
The obvious question
that comes to mind is,
''Why not just float the bat-
tery?" In my experiences as
a two-way service techni-
cian, 1 have found that the
majority of lightning-
caused damage is because
of lightning hits on the
commercial power line.
With this in mind, it was
figured that the probability
of damage would be great-
ly reduced if the battery
were only hooked to the
charger for the 2 to 3 hours
per week when it was
charging. If you don't ex-
pect to ever get hit with
lightning at your site or if
you like to gamble, then
S-« LfiTCH
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Cr PC-- 4 25V ELECT
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Fig. i. All fixed resistors are V4-Watt 10%. The PC board mates with a 15-pin edge
conriector.
skip this article and jump
over to the next one.
However, if you ^re a
natural pessimist like
myself, read on. (Re-
member Murphy's Laws: If
it can possibly go wrong, it
will If it is impossible for
anything to fail, it still will)
Another reason for using
the type of charging
described here is one of
battery life. A battery that
is on a continual float is
likely to go bad much
faster than one that is
charged and recharged on
a regular basis. The follow-
ing circuit contains all of
the features previously
described.
Circuit
The circuits for sensing
charger turn-on, charger
turn-off, and low- voltage
disconnect make use of
three sections of a
Motorola MC3302 quad
voltage comparator. This
device provides a TTL-
compatible output that is
at a high stage when the
inverting input is below the
reference voltage (on the
noninverting input). When
the voltage on the
inverting input is equal
to or higher than the refer-
ence voltage, the output
switches to a low state The
reference voltage is sup-
plied by an MC7805CP
regulator chip. Potentiom-
250
WR7AEK/WMDf=*X
WiTTERV CHARGER
V0LTIK66 SEN5ING.
Fig. 2. PC board
eters R1 and R2 are used to
set the switching levels for
the voltage comparators.
(Both pots act as voltage
dividers across the batterv
voltage.) (See Fig. 1 J
The output of the com-
jarators (lA and IB) are
looked to a NAND gate
(1/4 of a 7400 IC section,
2A) which drives two more
sections of the 7400 chip
(28 and 2C). Sections 2B
and 2C are hooked in what
is called a set-reset latch
configuration (abbreviated
S-R latch). The device is ef-
fectively an on-off switch
(an electronic latching
relay, if you will).
When a low is applied to
the set (S) input, the output
(Q) goes high and stays
high. The Q output will
stay high even though the
low on the S-input is
removed. To "turn off" the
latch, a low is applied to
the reset (R) input. The out-
put will stay low even
though the low on the
S-input is removed. The
Q-output drives an MPS-
A12 Darlington amplifier
transistor (Q1) which acts
as a relay driver.
Because of the ex-
tremely high gain of the
MPS-A12 (HpE = 20,000),
the device works very well
at TTL levels. The device is
capable of switching a 5(X)
mA load. Q1 drives relay
Kl which is used to switch
the 110 V ac line to the bat-
tery charger. A relay with a
good gap between the
normally-open contacts
should be used so that line
surges (i.e., lightning hits)
will not jump across the
gap-
Let's look at the action
of the circuit during a
typical discharge and
recharge cycle. The logic
states for the output
switching points are shown
on the schematic to make
it easier to follow. Starting
at a full charge, both out-
puts (pins 1 and 2 of IC1)
are low; hence Kl is turned
off (the S-R latch is reset by
the low on the R~input (pin
2, IC2). As the voltage
drops below 15 V, output
pin 1 switches high, placing
a high on one input of
NAND gate 2A(pin13)„ In-
put 2 of IC2 is still
low, since the voltage is
still over 12.5 V. When
the voltage drops below
12 5 V, ICIB output (pin 2)
switches high. We now
have both gates of NAND
gate IC2A high. This causes
its output [pin 11) to go
low. This low makes the S-R
latch output (Q) go high,
turning on Q1, which pulls
in Kl. Kl turns on the
charger. As the battery
charges, the output of IC1 B
goes low when the voltages
go over 12.5 V. The battery
will continue to charge un-
til it reaches 15 volts. At
this point, 1C1A output will
go low. When this happens,
the S-R latch is turned off
by the low on the R-input
(pin 2, IC2B). Q goes low,
which turns off Kl and
disconnects the charger.
The remaining two sec-
tions of the circuit [IC1C
and Q4) are the low-
voltage and overvottage
protection fail-safe circuits.
The circuits are referred to
as fail-safe because a
failure that actuates either
circuit will result in the bat-
tery being disconnected
from all circuits, and the
charger will be discon-
nected from the ac line.
This results in a "safe'' con-
dition where the battery
cannot be damaged by ex-
cessive discharge or over-
charge* Either of these con-
ditions is a major fault that
requires technical atten-
tion. Consequently, a
nonreversible disconnect
(blowing circuit breaker
CB1, which must be
manually reset) was chosen
to accomplish the job.
The low-voltage section
of the circuit uses the third
section of IC1 as the sens-
ing element. Operation is
the same as IC1, A and B.
When the voltage goes
below 11.5 V, the output of
1C1C goes high through D1
to the gate of SCR1 The
high on the gate causes
SCR1 to fire, placing a
short across the circuit
breaker and battery,
which, of course, causes
the circuit breaker to open.
Since the coil of Kl is ac-
tuated by the battery
voltage, the relay cannot
pull in to connect the
charger to the 110 V ac
line.
The remaining section is
251
WXXiiiA CH¥HetH
Fig. 3. Component layout
the overvoltage protection
circuitry. This is a conven-
tional "crowbar" circuit,
D3 and CI act to suppress
negative transients which
might trigger the circuit
When the voltage exceeds
15.5 V, the gate of the UJT
(Q4) fires, causing a
positive pulse to be
generated at base one of
Q4, The pulse is coupled
through D2 to the gate of
SCR1, which blows the cir*
cuit breaker as previously
described.
Output C is an optional
output used to drive a tone
generator. The purpose of
this option is to place a
tone on the repeater
transmitter to indicate that
the battery is below 12.5
volts and is not getting
charged- This warning will
give you time to correct
the problem before the
battery drops to 11.5 V and
is shut off by the low-
voltage protection circuit.
Fig, 4 shows an example of
an oscillator that could be
used for this option. If you
want to use this feature,
lumpers JU1 and JU2
should be installed and
resistor R5 omitted. If the
option is not used, jumpers
]U1 and I U2 should be left
out and R5 installed. Do
not install the jumpers and
the resistor, as damage
could result to the com-
parator IC,
Circuit Adjustments
The voltage levels stated
were found to be correct
for the battery we were
using (a 2CX) Ah battery),
However, you should
check your specif ic battery
to determine the limits you
want to set. The main
voltage to watch is the
"full-charge" turn-off. The
logical thing to assume is
that, when the battery hits
13.8 V, it is fully charged.
That's wrong! The battery
must be brought to a point
above that for it to take a
full charge.
The best way to deter-
mine this voltage is to
discharge your battery.
Run it down to about 12.5
volts. This should show a
'high red" area on your
hydrometer. Now charge
the battery at the rate you
intend to use in your
system Take regular
hydrometer readings until
the battery shows in the
"green" on the float.
Check the voltage at this
point. This is your full-
charge turn-off voltage.
When the charger is
disconnected, you should
read approximately 13.8 V
with no load on the bat-
tery. The other voltage
levels stated should be
adequate to prevent
damage to the battery.
The easiest way to set up
the voltage comparators is
with a variable voltage
power supply connected to
the "BAT" terminal (pin A)
of the circuit. Connect a
VOM [12 V descale) to pin
1 of IC1, Set the power
supply for 15 volts. Adjust
R1 until the voltage on the
VOM changes from high to
low (approximately 5 V to
less than .5 V). Drop the
voltage to about 14 V dc-
Run the voltage back up to
15 V. Make fine adjust-
ments on R1 until the out-
put switches to a low at ex-
actly 15 V. There wilt be a
very distinct switch from
high to low at the output
switching points.
Move the VOM to pin 2
of tCI. Repeat the pro-
cedure, but set R2 for a
switching point of 12.5 V
dc. Repeat this again using
ICI pin 13 and 11.5 V dc
(Disconnect the gate of
SCR1 to prevent it from fir-
ing.) Adjust R3, The remain-
ing adjustment is on the
overvoltage circuits. Con-
nect the VOM (3 V scale) to
D2 cathode. Adjust R4 for
a voltage increase (to ap-
proximately 1 volt) at 15.5
volts. Run the voltage back
and forth a few times to
check the setting. The fir-
ing voltage should be a
very distinct point. Recon-
nect the gate of SCR1.
After making all ad-
justments, give the circuit
a final smoke test Start at
15 V, The relay [KD should
be unenergized. Increase
to 1 6 V, The circuit breaker
should open. Drop to 15 V,
Kill the power and reset the
breaker. Drop the voltage
slowly. At 12.5 V, K1
should pull in. Run the
voltage back up. At 15 V,
K1 should open. Drop the
voltage down to 11.5 V. At
this point, the circuit
252
breaker should open and
K1 should open. Be sure
your power supply has
enough current to blow the
circuit breaker.
Construction
The value for CB1
should be chosen to meet
the requirements of your
particular station. The SCR
listed is sufficient to han-
dle at least a 25 Amp
breaker. If a fuse is used in-
stead of a breaker, a
smaller SCR could prob-
ably be used. Be sure to tie
all unused inputs of IC2
to +5 V through a Ik
resistor. It is recommended
that a 74C00 CMOS chip be
used for IC2 because of the
higher immunity to falsing
that it has as compared to
the 7400. The extra 154 for
the CMOS chip shouldn't
kill you unless you plan to
make two or three gross of
these circuits. All other
areas of construction
should be pretty straight-
forward. The circuit can be
built on a PC board (see
Fig. 2) or perfboard, which-
ever suits your needs.
The printed circuit
board was set up so that
either a 12 V dc or 6 V dc
relay could be used for K1.
If a 12 V dc relay Is used,
diode D5 should be in-
stalled with the cathode
connected to the 12 V line
or battery (base of U3), If a
6 V dc relay is used, the
cathode of D5 should be
connected to the regulated
5 V dc line (E of U3). The
high side of the relay coil
would be connected to
+ 12 V dc (pin A of card) or
+ 5 V dc (pin C of card) as
required. Do not omit
diode D5. This diode is
used to suppress the
counter EMF developed
when K1 is turned off: The
fow side of the relay and
the anode of D5 are always
20^ ]r — )h
^ fx 4UDI0
/fr
Fig. 4.
connected to pin D of the
card.
Fig. 2 is a full-size draw-
ing of the PC board. Fig. 3
shows the parts layout for
the PC board.
Parts can be obtained
from a number of the
advertisers in 73. However,
to save you time and prob-
ably money, arrangements
have been made with Tri-
Tek, Inc., to provide all of
the parts [including PC
board) in a kit form. You
can, of course, order the
entire kit or just the parts
you need- The entire kit
can be ordered by asking
for a "WR7AEK battery
charger kit/' [This doesn't
include board or parts for
the oscillator option.) The
entire kit costs $24 00. (It
includes SCR1 , but not CB1
or the edge connector.) The
PC board alone is $6.00.
I have made every effort
to make the text and
schematics as complete as
possible. If you have a
problem with the circuit
that I can help you with,
drop me a letter. I will
make every effort possible
to answer your questions
[SASE, please) ■
Nen^ Products
from page 204
W6T0G RECEIVER
MODIFICATION KIT
It wasn't until I began using a
new FT'901DM that I finally
concluded that my trusty FT-
101 B could stand some im-
provement in the receive mode-
With the two rigs tuned to the
same signal, and the antenna
switched back and forth be-
tween them, it became quite
apparent that the FT^QOIDM
was much livelier, t was also
able to copy weak signals very
close to extremely loud signals
that all loo often were impossi-
ble to pull out with the FT-IOI B.
Happily, as I was pondering the
situation and wondering what
might be done to punch up the
older rig's performance^ one of
the W6T0G FT-101 series re-
ceiver modification kits arrived
In the mail from S-F Amateur
Radio Services.
My long-standtng reluctance
to go mucking about in the
densely^packed solid-state in-
nards of modern rigs was
quickly overcome by the dis-
covery that only four small
components and three simple
steps were involved in the
modification. The fact that
things can be quickly and easi-
ly restored to their original
state was also reassuring.
According to the instruction
sheet, the purpose of the
modification is to 'Improve the
receiver sensitivity and help
eliminate receiver blocking due
to local signals/' That sounded
exactly like what I was looking
for, so, taking screwdriver and
soldering iron in hand, I pro-
ceeded to install the modifica-
tion kit in my FT-101B.
The Installation procedure is
quite simple. You locate the
receiver rf board, remove it, find
the rf amplifier transistor (Q1),
and replace it with one of the
transistors from the modifica*
tion kit. Then you locate foil
track 8 on the board and solder
one end of the pair of back-to*
back diodes supplied with the
kit to the track. The other end of
the diode pair is soldered to foil
track 7. The rf board is then
plugged back into the unit and
the high frequency if board is
removed. Find the receiver sec-
ond mixer transistor (Q2) and
replace it with the remaining
transistor from the kit. Replace
the board in the transceiver and
the modification is complete.
The entire process is quite
straightforward and takes only
a few mmutes.
In some instances, you may
find that after making the
modification you will have to
repeak the receiver section. If
you do, be sure to carefully
follow the instructions in the
alignment sectton of your
owner*s manuaJ. The time
spent properly tweaking things
up wiEl be amply rewarded later
by improved performance.
The installation of the
W6T0G receiver modification
kit has clearly improved the
performance of my FT-101 B.
It's livelier than ever before,
and I'm now able to copy sig-
nals that would have been very
difficult, if not outright im-
possible, to pull out of the crud
in the past. The decision as to
whether or not you should
make this modification to your
own rig is one you will have to
make for yourself, and depends
largely on the sort of operating
you do and the conditions you
are confronted with when on
the air. To help you decide, you
may want to write to S-F Ama-
teur Radio Services for a copy
of the combination information
sheet and order form.
In addition to the FT-101
series, there are receiver
modification kits available for
the FR-101 series, TS*520.
TS-520S and TS-a20/820S.
There is also the "MAGICOf^'"
processor modification kit
which converts the TS-820
speech processor from an rf
compressor to an rf clipper.
W6T0G receiver modifica-
tion kit prices are: TS-520,
$27,60; TS'520S, $32.50; TS-
820/820S. $34.50; FT-101 series,
$32,50; FR-101 series, $34.50.
The ^'MAGICOM*^ processor
modification kit for the TS-820
IS S27.50. All prices are
postpaid from S-F Amateur
Radio Servtces, 43B4 Keystone
Avenue, Quiver City CA 9Q230:
(213} 837^4870. Reader Service
number S33.
Morgan W. Godwin W4WFL
Peterborough NH
S-F RADIO DESK
I used to set up my first rig on
a small folding card table each
time I wanted to operate* and
then disconnect everything and
put it away in a cupboard when
I had finished- Since then 1 have
used quite a variety of objects
to hold my equipment and
serve as an operating position,
including an old rolltop desk, a
kitchen table, a garage work-
bench, basement storage
shelves, and a bookcase. For
the past year t have been using
Continued on page 262
253
W2NSD/I
NEVER SAY DIE
editorial i^y Wayne Green
from p&g$ 248
groups to cooperate toward
getting it off the air. You can't
telt me tliat an uncoordinated
repeater can stick it out wl^en
several hundred local harns
decide that ft should not be on
the air. There should be no
problem at all working up
teams of amateurs to drive the
scoundrel off the band. Hun-
dreds of tape-recorded mes-
sages played through the of-
fending repeater demanding
that It be taken off the air might
encourage it to be shut down-
VtsHs to the owner of the
repeater by rather large groups
of determined hams might also
get the idea through.
There are a great many ways
of tackling the situation, and
the mabtlity to cope with it is an
admission that the repeater
owner Is smarter than your
group. Let's use brains instead
of trying to get the government
into the act. Remember that
once you get the FCC moving,
you wHI have one hell of a Job
stopping them. The FCC invar-
lably overreacts to things like
this. It's the way government
works. Don't mess with it.
If repeater councils feel they
are not mentally equipped to
cope with some of the local
repeater owners, perhaps they
should get together with other
nearby councils and try to
locate someone in the group
with some ideas. There are
always a tot of ways of tackling
problems ... if you have a
creative thinker handy,
YOU MISSED BOXBOROUGH
Despite a heavy all-day rain
(or perhaps because of it), ex*
hibitors at the ARRL conven-
tion at 8oxborough (Massachu-
setts) set all-time records for
equipment sales. Many were
delightedly reporting double
and triple the sales of Dayton,
previously the top hamfest for
cash sales.
One reason for the tremen-
dous sale of ham gear was the
recent price increases. Dealers
at the convention had bought
at the old prices and were sell-
ing at discounts off the old
prices, so hams found them-
selves in a wonderland of fan-
tastic prices. They reacted by
buying everything fn sight. OSI
was there with their new
counters and sold out com-
pletely on Saturday. By Sunday
morning they had a new stock,
flown in overnight.
The New England ARRL Con-
vention is an odd one in many
ways. For many years it was run
at the old Swampscott Ocean
House. Then one year the hotel
burned to the ground Just a
month before the convention
and the event had to be moved
to Boston. This was not a
popular move, considering
Boston hotel and parking
prices- They tried Cape Cod
one year and found that
Greater Boston hams were not
about to drive that far for a con*
vention. The new convention
complex on Route 495 (the
Boston outside perimeter
road), the Sheraton hotel at
Soxborough, is a fine location
and met with ham approval. It is
estimated that well over 5,000
turwiJ put.
I say estimated because
security is not lax at this show
— It doesn't exist. If you want to
buy a ticket and have a chance
at the multitude of prizes, so be
it. They had 3,500 tickets
available and ran out of those
early in the first day. Tickets
were generally bought just by
the ham of the family, with the
rest tagging along at no
charge.
Most of the planning for the
show was done by Gene Hast-
ings W1VRK, an old-timer at
this event. Exhibitors had some
gripes . . . such as paying $300
for a booth with one table and
one chair, extra chairs
available for $20 each from the
show decorator . . , only to find
themselves facing flea market-
ers in the exhibit hall who had
bought a table and two chairs
for S4. Even worse* some of the
fleas hung up their business
Signs and went right into sell-
ing commercially.
The flea market, which was a
wet mess on Saturday, perked
up on Sunday, but to thinner
crowds. It was well managed by
Jack W1QXX, the keeper of the
antennas and large power
behind the yearly VHP contest
effort from Pack Monadnock in
New Hampshire, Jack will also
be found wherever there Is a
ham auction, a tradition going
back as far as I can remember
**. when there is an auction,
Jack is the auctioneer. He
takes these things seriously
and got into a big battle with an
itinerant badge maker who
tried to set up in hts flea market
in competition with the one
who paid for a booth Inside and
had an exclusive agreement.
This was finally settled when
the inside badge maker ran
completely out of badges. Only
then would Jack let the flea
market badger start grinding.
Despite a blanket prohibition
of my being permitted to speak
at ARRL conventions. Gene
managed to get me on the pro-
gram twice, once speaking
about software for microcom-
puters and the other on the sore
subject of WARC. I think he got
the software talk through head-
quarters by not telling them I
was going to do the talking. My
name didn't appear on the pro-
gram or on any posters In con-
junction with that talk. I'll bet
he had a battle with the other
one. One year they wouldn't
even let 73 buy a booth and ex-
hibit at Boston!
Speaking of sore subjects^
all of the dealers exhibiting at
the show were absolutely
furious about the HR special
deal with the ARRL... ap-
parently a sweetheart deal . . ,
where ARRL Handbooks were
t>eing sold across the counter
for $4.25! This is 85« teas than
wholesale, so dealers were left
with piles of Handbooks which
they couldn't sell. The book
regularly sells for S3.50, so HR
was selling it at half price . , ,
wonder what they had to pay
for it? Wonder what laws were
broken with that secret deal?
Despite the few grumbles
about the show, there is no
doubt whatever that New
England needs a yearly ham
convention in the Greater
Boston area. Finding the spot
for It is the big problem. The
Sheraton Boxborough was
hopelessly overcrowded by the
event. You couldn't get around
on Saturday. The exhibit hall
was filled with about 70 booths
. . . perhaps 35 exhibitors. The
restaurant couldn't cope with
the people, not having brought
in extra cooks or waitresses.
They had lines an hour long and
then ran out of food. Unfor-
tunately, there are no fast food
places within easy driving
distance of the hotel
On the good side, this
Sheraton is one of the best of
the chain. Tve had such lousy
rooms, service, and so many
problems that I've been
avoiding the Sheraton chain
like the plague. I had breakfast
there before the crowds arrived
and their food is no better than
elsewhere at Sheratons . . . very
poor. But the decorations were
gorgeous and they really tried
hard to make sure that those
with room reservations had
rooms.
Perhaps if Gene would cut
the banquet and use the ban^
quet halt for more exhibits . . . ?
And please, some sort of
lounge for the exhibitors.
MORE TROUBLE BREWING
A newspaper clipping sent in
by KA2CKV is enough to give
us a bad case of hives. It has to
do with a proposed city health
code amendment which is in
the works In New York City.
This has to do with setting the
levels for radio field strength
for emitted radio waves.
If this beauty goes through, it
will effectively throw most of
the hams in New York off the
air. Oh, hand transceivers
might escape the impact, but
most hams would have to have
their antennas a minimum of
200 feet from anybody, In New
York that kind of distance is
pretty expensive to buy.
At least there Is some
fighting of the proposed
amendment by TV broad-
casters, since they would have
to either drastically lower their
transmitted power or else move
their transmitters out of town.
Either move would ruin televi-
sion pictures for much of the
city and be a godsend to cable
television firms.
Until they outlaw irradiation
by police radar units, who ir-
radiate us with roughly 5,000
times more energy than is per-
mitted to leak from microwave
ovens, they should lay off
amateurs. The problem comes
from a worry about rf pollution.
1 love that use of the word
"pollution/' because It is
ridiculous in this context— yet
is a great emotional phrase for
the uneducated. Who can be in
favor of "pollution?"
The fact is that there have
been no definitive tests as yet
which indicate that radio waves
cause harm. I've been around
'em for over 40 years now . . ,
but perhaps that would be a
case to support strict control of
radio transmissions. Perhaps I
can point to my continual ir-
radiation by signals from DX
stations, repeaters, HTs, and
such as a possible reason for
the weird behavior of my
children. We all need some ex-
cuse for that, right?
If New York gels this one
through, will Los Angeles l>e far
behind? Will Peterborough
pass such a law and force me
to move my antenna at least
200 feet from myself? There
may be a big sale of 200'foot
towers soon. Should w© invest
in a tower firm?
MORE ASSISTANCE
We are looking for a couple
of hams who will, In exchange
for a subscription to 73, for-
ward mail to us. We have a mail-
ing list we rent out in the com-
puter field, and we need to
know when mail is delivered to
it, how long it takes for the mail
to arrive, and if the use of our
list was authorized. Alt our
254
^
assistants have to do is date
the receipt of mail and forward
it immediately to os for our
records.
4U1ITU
While visiting the ITU back In
June to check on the prospects
for survivai of amateur band
aliocations, I paid a visit to the
ham station in the ITU buiiding
in Geneva-
Here I am, on the left, with my
very good friend Gerard de
Buren HB9AW, who is the chief
operator at 4U1ITU, We're in
front of the ITU building, with
my little rented Fiat reflected in
the doorgiass.
This is the new ITU building,
just a short distance from the
older one, where 4U1 ITU is still
set up. H the African vote bloc
has too much influence at the
WARC meeting next October,
will it destroy the whole ITU
bodyof agreements which have
been built up over the last hun-
dred years?
I thought, if I didn't show you
this picture, you wouldn*t
believe my report that one of
the two (only two these days)
stations set up at 4U1ITU is an
oid CoiNns system. While I have
nothing in the world against us-
ing one of those lovely old rigs,
still , . . for a station that is sup-
posed to be used as a demon-
stration to delegates from all of
the countries of the world,
shouldn't something more
lechnicalTy modern be on
display?
Just to the left of the Collins
equipment is one of the new
ARRL low-cost CW rigs for im-
poverfshed amateurs. This was
designed as a solution to the
problem of amateurs not being
able to afford the average nevw
sideband rig. While it is true
that amateurs in many of the
small countries are not able to
afford a new Yaesu 901, the
whole concept of individual
communications is an anath-
ema to the leaders of countries
which are unstable, and that In-
eludes virtually every one of the
44-vote African bloc. These
countries might be talked into
the use of radio clubs, where
operators could be supervised,
but there is no way you are go*
ing to get very many individual
amateur stations permitted. It
Is Just far too dangerous
because the stations could
then easily be used for subver-
sive communications. This is
why the chaps at the ITU are
laughing at the ARRL and their
mini-rigs.
if you find yourself within
driving distance of Geneva,
stop in and say hello to afl of
the hams at the ITU , . , they are
a great bunch and you'll enjoy
the visit. Bring your license and
get on the air from one of the
smallest "countries" ..,
4U1(TU. Be sure to give my very
best to Gerard.
DXPEDmONING HINT
For those of you who would
like to get a little taste of what
it's like to be on the other end of
the pileups, take a good look at
the most interesting Eastern
Airlines special fares. The
chances are that you may be
Continued on page 277
255
Code-Practice Oscillators
an exhaustive report
Hank Oison W6GXN
1 75 1 CronerAve.
Menia Park CA 94025
From the earliest days of
amateur radio, code-
practice oscillators have
been an integral part of the
process of learning Morse
code. To be sure, a great
deal can be accomplished
O0t|iF
■9h
f a
i
l&4^g
0«-OFF
PHONES KEf ^^*^
^^^
Fig. 1. Vacuum-tube code
oscillator.
KEV
Fig, 2. Simplified vacuum-
tube code oscillator.
by copying off the air in
terms of receiving prac-
tice, but, for group instruc-
tion with a teacher or for
individual keying practice,
the code-practice oscilla-
tor is a necessity. In this ar-
ticle, I will take a look at
the various forms of code-
practice oscillators and
suggest ways of improving
them.
Perhaps the simplest
code-practice oscillator is
an electromechanical buz-
zer and a battery. Such
code-practice sets have
been widely used, and
some high-frequency buz-
zers for this purpose have a
remarkably ''pure'' note.
Vacuum-tube oscillators
came into use in the 1930s,
and one very common cir-
cuit for a code-practice os-
cillator is shown in Fig. 1,*
JACH OF
Fig. 3, Code-practice oscillator using r]eon'bulb relaxation
oscillator:
OMCS
750 1 lL0yD1«€SS)
fig. 4. Code-pra ct/ce oscillator using early germanium
NPN transistor.
In earlier designs, a type-30
tube was usually em-
ployed. Note that the key
and earphones are in the
B+ lead.
A simplified vacuum-
tube code-practice oscilla-
tor was also possible [one
that did not need an audio
transformer)which utilized
the inductance of the ear-
phones themselves, in a
Colpitts circuit. This is
shown in Fig. 2; the ear-
phones and key are still in
the B+ lead.
Since there are many
forms of vacuum-tube
oscillators possible (the
tickler feedback and Col-
pitts versions are in Figs. 1
and 2), it is possible to find
considerable variation in
code-practice oscillator
circuitry. However, gener-
ally, the oscillators all are
simple tickler feedback,
Cofpitts, or Hartley oscilla-
tors which are started at
each application of the
keyed B + .
The neon-lamp relaxa-
tion oscillator was occa-
sionally used as a code-
practice oscillator, as
shown in Fig. 3.^ This unit
256
SOME
msmfo
ms\s
Sooner or later almost all
ordinary ham antennas are
going to become victims of
bad weather.
But Shakespeare's
brand new line of two
meter and HF antennas is
an>ihing but ordinary.
WeYe new to the ham
market, but we've been
making marine and mili-
tary antennas for 26 years.
And those 26 years have
taught us how to make a
ham antenna that'll take
just about anything Mother
Nature can dish out.
Look at our 5705 om-
nidirectional VHF base
antenna, for example.
Its radiating elements
are non-ferrous brass and
copper, the finest practical
material available for con-
ductivity and corrosion
resistance. Surrounding the
ffS
Rberidass protects
radimingeleriient:^
from raifi und ice.
Therefore no
COfTOStCHL
Rbcrglass gives
added strength to
the antenna. J\e*
veiils breakage in
Hind and sleet.
Fibert^lass shield
firotects eteclncal
Ciiinpaiunls from
eorrtmon caused liv
Hber^ass prevents
rudiaiion p^terns
from cliiinging in
net weather.
rain or jce.
rf»-
Tte Mixif 1 57m
V}W Base AntcnM
And you don't have
to worry about radials
breaking off, because the
5705 do^n't have any.
But it does have seven
vertically polarized and
phased 1/2 wave elements,
stacked in col inear array
and providing an impres-
sive 10 dB gain.
And you can get op-
tional style 5709 reflector
that blocks out unwanted
coverage and gives you an
additional 2 dB gain in the
opposite direction.
And here's another im-
portant piece of informa-
tion: the 5705 is pre-tuned
at our factory to operate
in all environments. So it'll
never have to be re-tuned.
Our full ham antenna
line is featured in our new
catalog: The Cbmplete
radiating elements and electrical components is a
tough, flexible fiberglass shield. A shield that gives
the antenna the strength to withstand winds in
excess of 120 miles-per-hour.
The fiberglass keeps out rain, sleet and snow
too. So the antenna's radiation pattern won't
change, no matter how bad the weather.
Works of Shakespeare. And
the catalog is yours. For free.
For additional information just write Shake-
speare, Electronics and Fiberglass Division, Ctepart-
ment C, Post Office Box 246, Columbia, South
Carolina 29202.
Or call National Sales Manager John Hughes,
(803) 779-5800 WA4EAU.
d^z^e^aea^e
*
UI12
®
-Jh-
J
Fig. 5. Code-pracf/ce
oscillator using early
P-channet FET.
was designed to be
plugged into the octal ac-
cessory jack of a National
receiver, thereby utilizing
the receiver's speaker,
audio amplifiers, and
power supply. The neon-
lamp relaxation oscillator
was the only form of tube-
type RC oscillator com-
monly used as a code-
practice oscillator. Unlike
conventional oscillators
(which produce a more or
less sinusoidal output), the
neon-bulb relaxation oscil-
lator produces a sawtooth
waveform.
When the first produc-
tion (germanium) tran-
sistors became available at
prices low enough to in-
terest experimenters, they
were immediately pressed
into code-practice oscilla-
tor service. Fig. 4 shows a
typical early transistor
code oscillator using a ger-
manium transistor./" Note
that this is very similar to
Fig, 2, except that an NPN
transistor replaces the tube
and a lower plate (collec-
tor) voltage is used. The
convenience of only one
low-voltage battery to
operate such a transistor
code oscillator, and that at
very low current drain, was
a real boon to portability.
The circuit would be
substantially the same us-
ing a more modern silicon
NPN transistor, such as a
2N3641, If a PNP transistor
is used, the same circuit as
in Fig 4 can be built, but
the battery polarity would
be reversed.
As FETs became avail-
able, these were also used
in code oscillators. Fig. 5
shows a simple code oscil-
lator using one of the
earliest available P-
channel junction FETs.*
The N-channel circuit
would be the same, except
with the battery terminals
reversed. The FET code-
practice oscillator is
generally a bit simpler than
an equivalent bipolar tran-
sistor circuit
It must be made clear
that in all the oscillators in
Figs. 2, 4, and 5, the circuit
requires the use of mag-
netic phones having an im-
pedance of 2000 Ohms or
higher, tf low-impedance
phones or piezoelectric
(crystal) phones are used,
the circuits do not have the
required inductance to os-
cillate at the correct fre-
quency (if at all).
The circuit of Fig. 3 used
a neon tube as a negative-
resistance element. In
order to redesign the cir-
cuit for solid state, one
could simply replace the
NE2 with a four-layer diode
having approximately a
50~volt breakdown voltage.
Such diodes are made by
ITT. The circuit would then
be as shown In Fig 6. Four-
layer diodes are available
in lower voltages, however,
than neon bulbs, so a relax-
ation oscillator could be
built using an even lower
voltage, i.e., battery oper-
ated.
The circuit of Fig. 7
shows a unijunction tran-
sistor code oscillator, with
an FET audio isolation
source-follower after it to
drive the phones and an
NPN transistor as a keying
device. With this circuit,
you no longer have the
supply current flowing
through the key, and you
finally have removed that
same dc current from the
phones. [Dc through the
phones tends to eventually
demagnetize the magnets
in them.) The unijunction
transistor oscillator, like
the four-layer diode cir-
cuit, produces sawtooth
waveforms.
Fig. 8 shows a "com*
plementary" circuit for a
simple code oscillator that
uses an NPN (silicon) and a
tJOOwi
6.ajH
■#'T^
itOOOff
»SfT
Fig, 6,
/??
Fig. 7, Q1 = 2N3643; Q2 = 2N2646; Q3 = MPF102.
PNP [germanium) tran-
sistor which has been used
extensively by those hams
who swear by the ARRL
Handbook.^ The circuit
works well, driving an
eight-Ohm speaker direct-
ly, but is somewhat sen-
sitive to transistor substitu-
tions.
Since we've used nearly
every other active device
as a code-practice
oscillator. I feel that for
completeness I should
show one using an in-
tegrated circuit The cir-
cuit of Fig. 9 uses an inex-
pensive and widely-
available IC. The NE555V,
as first introduced by
Signetics, is now second
sou reed by nearly all linear
IC manufacturers. This IC
costs about 50 cents and is
keyed, in this circuit, by a
transistor costing about 30
cents; so the semiconduc-
tor cost is well below a
dollar. The key is not in the
+ Vcc line, nor are the
phones; and the code oscil-
lator operates on a 6*volt
battery such as a 4F lantern
battery. The waveform out-
put is essentially a square
one.
Up to this point, I have
concentrated on code-
practice oscillators that
have as their prime goals
simplicity and the use of
low-priced components.
This aim has apparently
been in vogue because it
was assumed that such
oscillators are used only by
beginners. However, there
are many clubs with
regular code classes con-
ducted by expert CW
operators, who no doubt
despair at the sound of the
average code-practice os-
cillator.
Morse code, as it comes
out of the receiver, has a
somewhat different quality
to it than that from a code-
practice oscillator. The
receiver output is usually a
near sine wave (providing
the station being copied is
'T9" and we have a good
signal-to-noise ratio). The
note sounds as if it simply
"appears and disappears"
rather than having the
"crashing" quality of some
Fig. 8. Code oscillator using
complementary-pair (PNP
and NPN] transistors. Q1 —
2N2102; Q2 = 2N301,
258
code-practice oscillators.
In a search for a code-
practice oscillator which
has a more authentic on-
the-aif sound, the first re-
quirement is having a sinu-
soidal waveform. There are
a number of circuits for
generating sinusoidal
waveforms; one such cir-
cuit is the Wien Bridge,
used in most laboratory
audio generators. The
purer the sine wave,
however, the longer these
oscflfators take to stabilize
(BATTERY]
t
VCfN-DFF
:;2,4K
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ilJK
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£0000
PHONES
Fig. 9. Code oscillator using NE555V integrated circuit
when B+ Is applied. In
short, really pure sine-wave
oscillators are not suitable
for being keyed on and off.
One solution to the
problem would be to allow
a high-purity sine-wave
oscillator to run con-
tinuously and then gate its
output on and off. This has
one problem: The key
closure and opening times
do not coincide with the
zero-crossing times of the
[asynchronous) sine wave.
Such asynchronous gating
of the sine wave causes
transients to be generated
that are very much like the
''key clicks" of an im-
properly operating trans-
mitter, so far as the listener
is concerned.
It is possible to build a
zero-crossing gate circuit
—2 IM44 54
SCHHiTT TRIGGER
+ 7.5V
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Fig. 70.
EXTERNAU
LE^EL
MOM "POLAR
IK EXT UeVEL ADJUST
p-^w^^ — *
0.2 2^F ^
l^» \] 1_^!
SOV
gainF '
TO AUDIO
AMPLIFIER
ff7 TANT
CODE IM
Fig. n. U1 = LM458N; U2 = LM741CN. Q1 = 2N3641 (pick individual transistor for
best noise output).
which delays turn-on and
turn-off of the sine wave
until that sine wave has
reached a zero^crossing
point. The penalty we must
pay for the transient-free,
pure-sine-wave gated audio
pulse is delay. If the
sine wave is 1000 Hz, the
worst case would be slight-
ly less than 1 ms delay at
the start and 1 ms at the
end of a keying pulse. Such
a 1 ms delay would be
almost totally undetectable
to the ear.
A circuit, admittedly
complex, which ac-
complishes the zero-
crossing gating function is
shown in Fig. 10. A Wien
Bridge oscillator is used to
generate a pure sine wave,
and this is gated by a
CD4016 analog gate. The
CD4016 is a member of the
RCA-CD4000 series of
CMOS logic; it functions
very well as an analog gate
and is much less expensive
than special ICs made for
this purpose. The same sine
wave is squared by a
Schmitt trigger (LM311) to
more sharply define the
zero crossings. The output
square wave of the Schmitt
trigger is differentiated and
the negative resultant
spikes removed by a diode
(D3). The positive spikes
are inverted by the
saturated amplifier, Q1,
which makes them avail-
able at CMOS level to the
logic ICs. The sequence of
events in the logic is too
tedious to go through here;
you can go to reference 6
for details, if you're in-
terested. The net effect is
to delay the opening of
gate U3, after application
of a key pulse, until a
negative-going zero
crossing of the sine wave oc-
curs. The gate is then
held open until the key
pulse ends, plus whatever
time It takes until another
negative-going zero
crossing of the sine wave
occurs. The logic uses the
negative-going spikes from
Q1 as information as to
when the sine wave is mak-
260
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magazine
Peterborough NH 03458
259
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COMMUNICATIONS
Connecticut Residents Call:
203-667-0811
95 Kitts Lane
Newington, Conn. 06111
"Near ARRL Headquarters"
r
master ctiarg:?
W&l*
OPEN MON.-FRL 10 6 • THURS- 10-8 P.M. * SAT. 10*4
EASY DIRECTIONS: Rt. 15 South - 2 blocks past McDonald's (Berlin Turtipike)
p^ Peatfer Service— s&e page 323.
2i6l
ing a negative-going zero
crossing.
If you really want to of-
fer code practice with as
close as possible to of f-t he-
air flavor, and yet have it
under the control of your
code class instructor, one
additional complication
may be added. A white-
noise generator and opera-
tional adder can combine
the code signal and the
noise to produce any (ad-
justable) signal-to-noise
ratio desired. In Fig. 11 is
shown such a noise
generator and operational
adder. A back-biased
emitter-base junction of a
transistor is used to
generate the noise as it
goes into avalanche. Two
operational amplifiers
amplify this weak ava-
lanche noise by a factor of
up to 500. The third op amp
is the operational adder,
which has three combina-
tional inputs: noise, code,
and a third extra input. This
third input could be used
to input background QRM
from an actual HF receiver,
if you really wanted
realism. Note that each of
the three inputs to the
operational adder has its
own level control and the
total combined signal level
may be adjusted, also,
Fig. 12 shows a regulated
power supply and audio
output stage, suitable for
Figs. 10 and 11. One of the
older IC audio amplifiers is
used because it is easier to
use in the low gain mode
than some newer ones,
which operate only in the
fixed (high) gain mode.H
References
1, Editors and EnQineers, Radto
Handbook, 7th edition. 1940, p.
15,
2, Lewis, A,, ^^HJnts and Kinks,
Code Practice Oscillator"
QST, March, 1950, p, 51
3. Sytvania, Performance
Tested Transistor Circuits,
1958, p. 35.
4. Flanagan, R., "Hints and
Kinks, FET Code Practice Oscil-
lator," OST. July, 1967, p. 4a
5. ARRL, The Radio Amateuf's
Handbook, 48th edition, 1971,
p. 12,
6. Oison, H,, "Tone-Burst Gale
Minimizes Distortion,*' Elec-
tronic Products, March 19,
1973, p. 190.
on
HEFirs
MOTOftOLHl
I a
-MA^ *
(3* /T7
vJT'
»t?v
-J2V
-4
39 &F
ioo#r
I3¥
AtilHO tH
Ht
ion
1^
1£&
ffr
I
f — "^JbV
-±-1000
Disc
ADJUST
4^ tP*f
Tr 5it
Fig. 12. Power supply ^nd audio amp for zero-crossing code oscHtatOf (use with Fig. 10 or
111 U7 = Motorola Ma454Q HEP593, HEPCe093Q MC1554C.
Nei^ Products
from page 253
an office conference table,
perhaps the most practicai and
convenient of all the many
items pressed Into service over
the years I have been an
amateur, However, the con-
ference table is novw being
relegated to more prosaic duty
in my of flee- work room. The
reason for the table's retire-
ment is my new S-F Radio Desk.
The S-F Radio Desk was
ctearty designed by an amateur
for use by amateurs. It is a two-
tiered affair with pienty of room
for two HF transceivers and an
amplifier, as well as my 2*meter
rig, an antenna tuner, and a cou-
ple of other small accessories
— without crowding or over-
loading. The rear of the bottom
tier is angled so that equipment
placed on it is tilted upward at
the correct angle to provide
comfortable viewing and ease
of operation. Below the main
desk surface is a convenient
shelf for holding small ac-
cessories when not in use-
logs, Cailbooks, and all the
other items that otherwise lend
to clutter up the desktop.
Measuring 39 x 30 x 50 Inch-
es, the Radio Desk is available
in either teak or walnut finish,
or unfinished birch veneer.
Assembly is required. All hard-
ware is supplied, and clear,
easy-to-follow illustrated In-
structions make it simple to put
together. The only unsupplied
item I needed was a bit of
Elmer's glue. Assembly went
without a hitch and was com-
pleted by the time I had fin-
ished two cups of coffee. The
finished desk is a mighty at-
tractive addition to the shack
and I wouldn't hesitate putting
it in the living room for every-
one to see.
If you could use an operating
desk that will hold your equip-
ment, improve your operating
efficiency, and, at the same
time, has sufficient eye appeal
to satisfy the wife and rest of
the family, you ought to be con-
sidering the S'F Radio Desk.
The desk is priced at $139.95 in
teak or walnut finish^ and
$124.95 in unfinished birch.
Prices inciude shipping by
UPS. S-f Amateur Radio Ser*
vices, 4384 Keystone Avenue,
Culver Cffy CA 90230; (21 3h
837-4B70. Reader Service
number S33.
Morgan W. Godwin W4WFL
Peterborough NH
NEWTRONICS ENTERS 220-
MHZ AMATEUR BAND WITH
iNTRODUCTlON OF ALL-NEW
1V4 -METER 7-DBGAlN
VERTICAL FIXED-STATION
ANTENNA
The alt-new Hustler 220-MHz
vertical fixed-station amateur
antenna, designated the Model
G7*220, was recently intro-
duced by New-Tronics Corpora-
220 MHt
Vertical Anteniu
rft.
New'Tronics' new 220-MHz ver-
tical Mustier antenna, the
Model G 7-220.
tion of Brookpark, Ohio. The
G7-220 marks New-Tronics* en*
try into the now-popular 220
MHz band and complements
their existing base and mobile
amateur antenna line. The
superior 7-dB gain of the anten-
na, fof both transmitting and
receiving, makes it one of the
most powerful omnidirectional
1% meter antennas available.
The ail-new rugged design of
the Hustler 07-220 antenna
keeps the signal radiation pat<
tern at the lowest possible
angle to the horizon, for max-
imum efficiency and longest
range.
The Model 67-220 has an swr
of 1.5:1 across its entire 5-MHz
bandwidth, with swr at reso-
nance of 1.2:1 at the antenna.
The radiating elements of the
Hustler 07-220 are dc-ground-
ed for lightning protection, and
the antenna has a SOOhm base
impedance.
This new Hustler 220-MHz
vertical combines the latest
antenna technology and the
best available corrosion-
resistant materials for extra-
long life. Only Hustler uses all
stainless steel hardware in
amateur and professional prod-
ucts. Each component is pre-
cisely built for quick and easy
assembly.
Continued oft f^age 272
262
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6 GOOD REASONS
FOR BUYING A HAL IRON IX
FREQUtNCV COUNTE.R
(I) 100% COMPLETI fCJT. m EASY ASSEMBLY. (3> COMPLETtLY ENCLOSED IN
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MENT (SJ EASY ON YOUR POCKiT BOOK. AND (6) NO £XPEN5(VE CHIPS TO
IttPLACr tEXAWPlE— IF YOU LOSE A DtCODtR. LATCH OR DI*3VI IN A HAL^
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IS LESS THAN S I 00 EXCLUDING THE PRE SCALE CHIP. IN SOME Of THE NEWlfl
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EXOTIC SENCil CHIP AND WOULD COST YOU CLOSE TO J30-00 TO REPIACEJ.
THIS IS SOMETH[NC YOU SHOULD CONSIDER.
ANALOC-DICILAB
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DESIGNED BY HALTRONIX
AND MIKE GOLDEN OF
R.E.T^S, ELECTRONICS
SCHOOL OF DETROIT. FOR
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SPEClFtCATlONS: OUTPUT VOLTAGES: +5V. + 12V, -12V; USABLE CUR-
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end fall time. Frequency delermtr^td by Function Generator. Output impad^
ince 1.2K otim.
Mast of all Jt '6 easy lo construct and service. PC boards are predrlHed, plated
thru and solder flowed. Over lOOO urvlta sold to schools.
0
FROM HALTRONIX
HRST TIME OFFER
SIX IMOn AlAKM tLOCl KIT for tK)fn<j, camper. RV, Of fierd-dlj^ U&e. Opera iftS
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with all electrode components artd two-piece, pre-drilled PC boards. Board
$lze 4" X 3" Complete with fipeaher and switclias. If operated on DC. there ts
nothing more to buy.*
Twelve-volt AC Jine cord for those vwho wish to operate the clooh from llO-volt
AC. S2,50
*Fits clock case advedlsed below.
TOUCH TONE DECODER KIT
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INTiRSIL EVALUATION KIT
BUILD YOUR OWN D.V.M. or D M,M. LOW COST DIGITAL PANEL METER
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ACCUKfYIft tlOTJ THIS ACCUKEYER IS A REVISED VERSiON OF THE VERY
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ACCUttEYEt^MEMORV OPTION KIT THIS ACCUKEYER MEMORY KIT PRO-
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SHlPPtNQ INFORMATlOfI
ORDERS OVER $15 00 WFLL BE SHIPPED POSTPAm EXCEPT ON ITEMS
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115.00 PLEASE INCLUDE ADDITIONAL SlOO FOR HANDLING AND MAILING
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BY POPULAR DEMAND
— we are conrinuing to offer with
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llfCj^ retail price of S20).
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DELUXE 12^BUTTON TOUCHTONE ENCODER KIT utilizing irte new ICM 720&
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For those who wish to mour^l the encoder in a handheld unit, the PC board
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PRICED AT....... - S14.95
PRE-SCALER KITS
HAL 300 PRE .$19.95
fPre-d rilled GIO board and ^11 compor>ents]i
HAL 300 A/PftE. , . , , . „ . $24.95
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(Pffrdhlled GTO board and all componenls)
HAL 600 A PRE. , $39.95
(Same as above but with preamp)
SfECIAL OFIER— While they Ust
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the FND-359 same pin-out.
10 units {.40«)— 10/ 4.00
100 units ^35e)— 100/ 35.00
500 units (.300— 500/150.00
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i^H24
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263
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the W6TOG* ^^'^
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TS-&20 KIT $27,50 FT- 101 SERIES KPT . . $32.50
TS-520S KJT 32.50 FH-101 SERIES KJT . . . 34.50
TS-820 & 820S KTT 34 SO FT ^301 SERIES KIT 34.50
R-599 A/D KIT . 27,50 FT~901 SERIES KIT . . , 34,50
EXPUOT INSmUCnONS MAKE MODtFICATlON A ONCH
IT'S MAGIC. . .
IT'S "MAGICOM"
PROCESSOR MODIFICATION KIT
IMPROVES AUDIO PUNCH
IMPROVES PROCESSED SPEECH QUALITY
Converts TS'820 / 820S speech processor from RF
compressor to RF dipper $27.50
RF speech pmcessor for TS-520 / 520S $4Z50
The "MAGICOM" RF processor module provides up to
6dB increase in output with smooth, dean,
non-distorted audio and more penetration for those
pile-ups.
ENDORSED BYAVSTOG AND BIG GUN T>Xmm WORLD WIDE
the W6TOG *
INTERNAL ELECTRONIC KEYER
FOR ALL AMATEUR TRANSMITTERS OR
TRAl^SCEIVERS USING GRID BLOCK KEYING
• No holes mounting with TS-S20 Series
• Mounting options forTS-520, TS-520S, FT-101
Series, TR4 Series, T4X Series, T-599 Series and
325 Series.
• C-MOS DESIGN — E)ot and dash memoiy — fuH
iambic or manual operation.
• Simple installation v[^ $49.50
THE S-F REJEKTOR
FILTER
AN II^EGRATED CIRCUIT
ACTIVE BANDPASS FILTER
FOR PROCESSED RECEIVER AUDIO
• Separate active filter demente
for CW and SSB audio output stage
• 8 ohm input and output impedance
• Headp hone jac k for con ve nience
• ON CW: from 500 hz to 100 hz. variable
• ON SSB: 2 Khz fixed bandwidth
• Rej^:ts unwanted signal better than 60 dB
• Designed for today's transceivers
or yesterday' s older equipment $49 . 50
HZ EuniioniQ, IK.
r
i^Zl
ssr^.Sr
HAH
We Sell & Service
These Lines:
ICOM
Ameco
KLM
SAY Power Supplies
Dentron
B&W Switches
SWAN
Shore
KDK2015R
Integrated Electronics
TenTec
LARSEN
Wilson
ADI Auto Dialers
Telex
PanaVise
Hustler
Amphenol
Mo s ley
Aluma Towers
Cushcaft
And Many More
Special Prices On
These Items Now:
ICOM 211
KDK 201 5R
Ten Tec 570
Ten Tec 574
Dentrol All Band
Doublett
SWAN TB4HA
SWAN TB3HA
Dentron MT2000A
Dentron MT3000A
ICOM1C215
KLM 144-148-16
K LM 1 44-1 48-1 4
KLM 144-148-50
RC8X COAX
Dentron Big Dummy
Dentron Ir. Monitor
YAESU 7T101EE
ICOM 245SSB
SAY Elect. Power
Supplies
KLM 2-25B
10'&15' Roof Top
Tripods
j*-r>
*i^
/
We accept
MC & Visa & Interbank Cards
-wilUhip UPS CO. D.
422 ARMOUR CIRCLE N E
ATLANTA GA 30124
(4041 87li^0fc31
Come by oi call
Will!afTi/WA4SVY
All prices po«iitpaid - in C^lif. add 6% »alcs tax - MaitCTchai^ & Visa accepted
fc^ SATTSFACnON GUARANTEED OR MONEY REFUNDED J
A'V
264
p^ pB^dBr Service— see pags 323.
the microcomputer-controlled
appointment clock
— IMOTAKIT
Regular Price S 79.95
Introductory Offer by
Hal-Tronix
only $69.95
FEATURES:
• Sleek modern styling to complement any
home or office decor,
• Tells the time,
• Tells the date and year,
• Op-timer to 60 minutes^ 59 seconds with
pause*
• Alarm to ring at the same time everyday.
• Daily appointment sets appointments for the
next 23 hours, 59 minutes*
• Future appomtmenls up to one year.
• Dimmer switch for display^
• /viemory will hold up to 30 appointments,
• Lithium power cell to retain memory during
power outage.
• Appointments entered out of chronological
order wiii be stored in chronological order*
• Colon flashes once each second.
• A.M./P,M. indicator,
• Plugs into any wall outlet,
• Easy to read vacuum fluorescent display,
• Extremely accyrate quartz crystal clock,
EFFICfpNT. REMARKABLE.
TimeTrac sold and distributed by HAL-TROC^IX, Deajtfs w^lc^me.
Send 1 5<t stomp or S.A.S.E. for information and fSyef on other
HAL-TRONIX products. To order by phone? 1-310-2d5-1762.
'MAL"
HAiOtD C NOWIAHD
wezxH
Hal-Tronix
P,0, DoK H01
Southgate, Ml 46195
^H24
SHIPPiMG
IHFOKMATiON*
ORDEfti OVER i 1 5.00 WILL DE SHIPPED POSTPAID EXCEPT
ON ITEMS WHERE ADDITIONAL CHARGED ARE REQUESTED.
ON ORDERS LESS THAN SI 5.00 PLEAS£ INCLUDE ADDITION-
AL » LOO FOR HANDLING AND MAILING CHARGES.
TERMINAL UNIT
Connsct to your receiver speaker, transmitter
microphone jack, and teletype machine and you^re on
the air. State of the art design features make the
TU-170 Ideal for HF and VHF autostat operation.
Proved 170 Hz shift actpve
filter demodulator
Lighted tuning fiieter for
easy tuning
Current regulated loop keyer
&. power supply
Autostat with threshold
control and solid state relay
, Stable audio frequency shfft
osciNator prodifGes ph^se
coherent sine wave tones
TTL compalfble mputs and
outputs for auxilliary
equipnnent
. High levei output ioT scope
tuning
TU-170 TU-170
Kit 149.95 Wired 219.95
Fhsher productB . . . Me cr/f/cs cAo/ce/
B FieSBEl MRP. ^
P-O. Box 976, Topeka, Kansas 66601 (913) 234-0198
N888
HAIMD-HELD
HF/SSB
D 10 Watts PEP
D 2-9 MHZ
D USB/LSB
D Rechargeable batteries
D Accessories
The NSaS permits long
range communications in
difficult and adverse
locations, thereby offering
important communication
advantages over AM and
FM.
The smallest complete
personal H.F, SSB
communication system
available.
1^
NORTHERN RADIO COMPANY
COMMUNICATION PRODUCTS
T4g75NORTHEAST40TH.f^eDMOWD.WA3KINGtON9B052,lJSA
^2QQ^ SB3-7700 TELEX" 32-1160, CABLE ADDRESS' -NOFlLECTfl AD
p^ F^eader Service— see psge 323,
265
BARKER &
WILLIAMSON, INC.
POAviAi oxMixr^uirc am n A^r^CQQr\D I PQ
PRICE
V 1 1 ^^ 1 1 L
and RF swi
Outputs
tching
37&
18.95
6
PROTAX Sk/Vitch Gfc^uixJsall except «tec!eri«
37€
18.96
5
PHOT AX switch. Grsiuridsau excepl aclef:ied
ouipuT CifCyit. Suflb !S-^wiTi:n PO.SiTiQft grounds
5G0A
14,00
5
5S0A.2
12.50
2
S51A ^
17.50
2
special 2-pole, 2-pH3sitian swrTch usftd to
swiich any RF devn:* <n of oui ot series.
S56
.95
-■
SfacKBl oniv. tor wall mounTii^ot f4Jdi^>
g onnec tor s w 1 1 ches.
590
1 7.9S
5
59QG
17.95
5
Griiurtdi i^if except selected -ouTput cifcu^t.
S92
1^.50
2
505
18.50
6
Grounds aH e^cepi stiJ4i<:ie0 output circuii .
COAXIAL SWITCHES AND
ACCESSORI ES for antenna selec-
tion and RF svuitching. These
high^qualitv switches have set the
standard for the Industry for
years. Ceramic switches with sil-
ver alloy contacts and silver-
plated conductors give unmatched
performance and reliability from
audio frequencies to 150 MHz.
BSiW coaxial switches are de-
signed for use with 52- to 7 5- ohm
non-reactive loads, and are power
rated at 1000 watts AM, 2000
watts SSB Connectors are UHF
type. Insertion loss is negligible,
and VSWR is less than 1.2:1 up to
150 MHz. Crosstalk (me&sured at
30 MHz) is 45 dB between adja-
cent outlets and -60 dB between
alternate outlets.
McMkf 37ft
HiMWBHa
-•■v-
*••«•.
MhIm Svo
MhMUOA-2
IVfaiM5e2
kA250lH Kit .
PA4010H Kit .
PASO/25 Kit. .
PA144/IS Kit .
PA 144/2 5 Kit .
PA220/1S Kit .
PA432/10 Kie .
PA14O/10W/T
PA 140/30 W/T
2 mtr power amp -kit lwin-2Sw
out wiih *olid stale switching,
case, connectors- . „ . h . ^ * , * 64,95
2 nilt power amp-lOw in— 40w
out— relay svvitching ........ 64.95
6 mtr power artip, Iw in* 25 w out,
1*£S case, connettorji &.. switching S4.9S
2 mtr power amp-lwin— iSw
out— less case^ connectors and
switching , . . . , 44.95
same as PA144/1S kit but 2Sw . 54.9 S
similar to PA144/1 S for 220 M Hi 44/95
power amp-siTniiar to PAj44/iS
except 10wand432 MHz ... S4,^S
lOw in-l40w out-2 mtr amp . 219.95
30w in-l40w out— 2 mtr amp . 189.95
POWER AMPLIFIERS
Blue Line
Model
BLC 10/70
BLC2/70
BLG 10/150
BLC 30/150
BLD 2/&0
BLD 10/60
BLD 10/120
BLE 1 0/40
BLE 2/40
BLE 30/SO
BLE 10/80
Rl power amp:; wired <t iested4 emiH^ion —
L'W-LM-SSB/AM
Power Pcjwtir
BAND I"P"t Oyipul
144 MHz
tow
70W
La'*.^?
144 MHx
2W
70W
169.95
144 MHt
Km
I50W
2 5 9.9 S
144 MHz
30W
\ 50W
23 9.95
220 MH2
2W
60W
164. 95
230 MHi
low
60W
IS9,95
220 MHz
lOW
120W
25 9 95
420MH1E
lOW
40W
179,95
420 MHz
2W
40W
179,95
420 MHz
30W
eow
259.95
420 MHz
low
sow
289.95
POWER SUPPLIES
PSiSCKJt
PS15CW/T. ,
KS25M Kit, .
PS 25M W/T,
PS3A Kit . .
1 5 amp- 1 2 vf>lt regulated power Sup-
ply w/cAse, w/fold-back current limit-
lit E ^nd overvoltagt^ protect toa . . 94,95
same as above —wjrt;! tl ^ tested, . . 124.95
25 amp— 12 volt regulated power sup-
ply w/c^se, w /fold -hack current limit-
ing and ovp^ with meter .►,,.. 154^95
^ninie as above— wired & testi^d. - . 17 9.95
adds over voltage protection to y<3ur
power suppllL'S. 15 VnC max. . , 12.95
1 2 volt ' poller supply regulator card
with fold-back turirent limiting , . 10.95
PS3012 W/T
new dommercial duty 30 amp 12 VD€.
regulated power supply w/case,
w/fald-back current limitini^and
overvtiltage prfjtection ,,,.., 249.95
f engineering
The most convenient way to order! Just call our Credit Card Order Department 9AM'9PM at (617)
395-8280, Your order will be processed immediately— you'll be receiving it even more quickly than
if you'd sent it by mail. Any way you look at it, our same-day service plus our special telephone
credit card service equal the fastest way to shop by mail! (Sorry— we can't accept collect calls,)
Helpful hint: To make your order as clear as possible, fill in ail Information on this order form, then
read it when you call.
VfSA
Prices FOB Medford MA.
MA residents add 5% sales
tax.
Minimum $3,00 for
shipping & handling
on ALL ORDERS.
Name
Call
Address
City
State
^ Zip
Order:
Credit card #-
Signature^
^ Checl< enclosed a Visa ^ Master Charge ° American Express
PRICES SUBJECT TO CHANGE WITHOUT NOTICE
Card expiration date
PLEASE - No Cash Or C.O.D.s!
Radio Electronics v^ia
209 Mystic Avenue
Medford MA 02155
(617) 395-8280
Toll free:
[800] 225-44SE
OPEN DAILY 9-9
SATURDAY 9-6
Tufts Radio Electronics • (6T7J 395-8280
TC-1
THOMSON CSF
NPC
ELECTRONICS
MODEL
12V4
102
107
loan
NET PRICE
$24.95
$39.gs
104R
lOaRM
109R
$49,05
179.35
S149.95
MODEL 103R
AUTOPATCH - Ready to gol
aODEL 108RM
r^ iwtf^ M|r ipi ^antf
^ r ^f fii
J
-^iflinAa: HT lifflll fiWHHHMii tli ^if wii W iai«
■of oiTBit DvtFiiiBi, Hvmitl^ iild Pvinti! Dron^tHn
lwBp«f«nf nahlvHjHiiiMviilMMr m|Mh mfta
innHittt bMdi peMf nnn ttm iviMo mtf mmom of
Rii'Tl'rihl'CDnm'iHMia I^Anlp
euimnH imil HAmp
15* ■ woe
lilV
lis
121
ilCvTJtiiMOC
#'* tMM*^ i*»in i&t
%kSO AV4ILAKLC AS MODEL tSB^tA
4IITHQUT MCTiq '!NlD OwERVOl-TAGf
*nOTECTlOH
MODEL 10411
n«(uia»d.
$«l<4 Sl«ta Ouai
115 *^ AC ■ 11 » f«l
•■ T»W J(X
tin Tvnc
i W MM}
frnp^mf Mli^fnit 'd4n
MODEL 107
ft.Jt'
HilUM
ill
Cv**rtiiifiisuwa
MODEL 12Ua
NPC 1.7& Amp
PiQiNBf Supply
3 Amp Mm
H4 lis «D<t5 AC b| il HfAl
DC 4dMtir &y«ied t«f iiwii
lAcJ^ing l-Hicfc fl#iw avglv
A Comprete Autopatch facittty that requires ortly a repeater
and a telephone line. Features include sir>e^e-djgi| access/
disconnect, direct dialing from mobde or hand-held radios*
adjustable amplifiers for transmitter and telephone audits, and
tone-burst transponder for acknowl^edgement of patch dis-
connect.
RAP-200 P. C. Card S1§9,S0
RAP-2D0R Rack Mount |249.50
ADDON
POWER!
Nighefl qLiaUTv, AmefJcan-rrtadfl 'brand '
iraflSiSlOiS are luliy prDtecteH fOf VSWR.
shofi and overload, rei^erse poiirrfy
Highly effective heat smiof^g as&uttf $ inr>g
hie, rehfltfe perfofmajice 84Ck yia<liied
comaners exdusive klM extruiion*,
h«¥e aewn, full lengm lim on
both *Mlci'
KLM RF Power AmpUtiers
or ridifl jm
■iv r fH] > c^' iw:i ■ |ih- ii>f
IVIODB.103R
Pbpi*^ Supply
Soiid Snt* Duvt
jmvti 11^ vDltR AC 11} tl E vQln DC t ZOO milliuOUt hjntm 7.E>
npj [;aiiiinLiiiit!i ind 4 aitip^ mji IdtaEly sui'ted lor &j»|)li(;iit|(Hkt
tiw& [» hrfudnd DC KabNlily art impodanft sudU as Cfi IraninitupiKi,
mM Hiam ridiD trjubmlltoi. tind hi{h qualify e^i^t-t^icN cai iilimi.
IF1 ilu be usKi 3D lriEi>e cioiKi 1? MfHl C3f bactwies
•■ A Simple, add-on-immediaiely
RF ampiiiiec
• Merely coax-connect ampflHer
beiween antenna and transceiver.
• No tuning' Efficient strip-lme
broad band design.
• Automatic! Internal RF-sensor-
cont roiled relay connects amplifier
w/ bene ver transmitter is switched on.
Manuat, renroie-posiiian switching
IS optional
• Models for 6.2.1^^4 meters. 70CM
amateur bands plus MARS coverage
• Two types: Class C for FM.'CW,
Linear (or SSB/AM/FM/CW.
• Negligtbte insertion loss on receive
• AmefEcan made by KLM,
New Model
List Price
PA 2 25B
$ 69.95
PA 4-70BC
189.95
PA4-70BL
189.95
PA 15reOBC
164.95
PA15^40BL
109.95
PA45-T20BC
2D9.95
PA 15^ SOB L
1 79.95
PA 4-40C
169.95
PA16-160BL
250.95
PAT5^35CL
154.95
PA45-140BL
219.95
PAIS^nOCL
279.95
i'tHii'>*~ifwiii**'
Ti'PHIAL
1 3.6 I 2 VtiC
MffiV
ti
it)l
13 Hi » JVIK
Umv
5 mV NMft
MODEL 102
WrC 2 S *rwp
PQin«f Supply-
4 Arfip M*ii. Solid SlBTI
FiilKilCHls silrt^tly 11^ CQiiv«r1
Nifj 11^ vdU AC 10 l^.vnlla
DC S.Sanips cHUiniwtK, 4 irnpi mti Eiifibl«s anymie id flniiiy CB
wMo, cv B'tach. oflrbdov. cui^nn Ujh! pliiyp or car radio m a hanu
fli tfNIcse
CenmuDua, Cuirenllf ullltiDiW^]
Aulpul VDlts^e 1.N0 Load!
Ouipuj Vonag* {Fun vjomAi
Ripfrtv trull LHdt
Short C*ct*r
2 5 Amp
lEVmu
4^J Vnnn
SjOKMuF
i'plj m*l»- pi) ■ *V (Of
■ ttn
slinky
SLINKY! S43,95 Kit A LOT oX antenna
in a LITTLE spate Now SflJnky^Uipole*
with hoJicaC Loading radiataK a gooci
'fiJBnali at ; /10 wafvelength longf
>NIW*( w# lit^.^lQ
NEW
^Continuaut tuning 1.8—30 IVlHz
* Forward reading relattve output
pouu@r meter
► 300 watt power capabrlity
* Built-lr^ drtcQpsuiated balun
* Mobile mounting bracket
Ceramic Rotarv Switch l2-|>o^-
tion
Capacitor spacing 1 000 volts
Tapped loroid inductor
Anter>nd Inputs^
a. Coax unbalanced 50239
b. Random wire
c. Balanced feedline 75 — 660
Ohm
S%'* w. X 2%'' h. X 6" d.
All metal black wrinkle finish
cabinet
Weightr 273 pounds
Price: $79.95
mrL
^^1 M 'MBtCkltl^U
i% -*#■ Tf 1
■**«»
This olectricaMy smalt SO/75, 40
& 20 meter antenna operates at
any length from 24 to 70 ft. • no
extra balun or transmatch needed
* portable ~ erects & stores in
minutes • small enough to f»t in
attic or apt. • full fegal power •
low SWR over complete 80/75,
40 8t 20 meter bands • much
lower atmospheric noise pick up
than a vertical & needs no radtals
• kit inch a pr, of speciaMy made
4*' dia. bv 4" long coils, con
tainirm 335 ft, of radiating con-
ductor, balun, 50 fiL RGS8/U
coax, PL2S9 connector^ nylon
rope & manuei^
SOLAREX
SOLAR CELLS &
SOLAR PANELS
in stock
Send for Catalog
KPlfO Kit-
KPJSO
HPTI44 Kit -
RFTIIO Kit ■
HPT4JZ Kit ^
H P r 1 44 W ft
RPT220W/T
HFT4J2W/f
DF*tASO . . .
DI>LAI44 . .
ref>tal<?r 6 meter 4^9.95
tcp^xtti -b meter, wired &. tested 799.9S
rEpcftlcr— 2 mtr-1 5w— compJcie
(less gr}^-&t>lt> . . , . 499.9S
repifjiffr- 2 20 M Hi— I Sw— complete
{Jcis tr>ii^i) .,,...,..... 499.^5
feptfatcf-10witt-4J2 MHz
(less. cry&CAb| , . , $19,9S
rep^jatcr- IS watt — 2 mlr- . . . , , 799.9S
reptriiier-lS wttl-220 MHz, . . . 799.95
reptater -H)witt-432 MHz. . . . 849.9S
& mtr crofeSlNlcetl ilupre^ner . . . . 57S.9S
2 mtr, 600 KHl sputtJ Juplexer,
wjriid and (urieJ lo fr^iiuency, , • Ji79.9S
REPEATERS
DFLA220
DI>LA4J2
DSCU , -
DSC-fi . .
220 MHz dui^kter. *tfcd and,
tuned to frctiucficy , . ^ . . . . . J79,9S
rvck mount duplener ....«,,. J|9«9$
douhie ihivlded duplexer cabtes
uirh PL2S** conrieclors (pr.) . . . ^S-Oa
umc as above wilh Jype N
cofinectQCs (pr.) - - - 25.06
if enainccring
Tufts Radio Electronics * (617) 395-8280
TC-2
ATB-34
4 ELEMENT BEAM
10-15-20 METERS
engtfi«e«fs hA^jG hfx:ofpofai^ mofe man 30
ye^rs of de^i^n eipertence mto t^ Desi 3 band
H¥ beam avatiable- io<}ay ATB*34 H^!^ supefb
perforfnance with ihre« acttwe ei&mertts on each
tiafy& the convefiience ol easy assemb'ly and
modfisl dimensions Value- ttirou9l\ h«awy duty an
alummym con&rruchon and a price complete wilh
t-1 baiun
ENJOY A NEW WORLO OF DX
SFECIFICATIOHS
FDftMTARQ 0*mt exCELLEMT
r/B RATIO • 30 d&
VSW« - 1 5-t
POWEW
NJ^NCH-NC JOOO WATTS PES*
BOOM LENGTHJ'DIA ^ Ifl ■ ? l.'A
LO^tGESt ELEMiWT ^ 32 S
TURNING RAOUS - tS 9
Wtt« SFC - 5 1 Sq F1
WEIGHT - 43 Lb3
WIND SOftVIVAL - 30 MP^
$259-59
UPS SHIPPABLE complete
COMMUNICATIONS WITH ATB 34
Hy^Giin REEL TAPE PORTABLE DIPOLE
for 10 tiiru 80 Meters Model 18TD
Ikt most partible high perfofmajice dipoJa ever...
^^^^stfi
Tb? Model IHTD i* uivtnmtmoMMj Ifae maA fbutpffxirhii^h pcf^irmaticp pcirtnble
lioubtet antesna •yiunn *w lirtthumi h tm prtriiii/<n iiivaluAbltf in proviiiini^
TvU«b}e o^miniuiiicAlkiJfiti in vitaJ mililAf^ uidtiifQiDrrvtal'*(3pLicatii3(ii^ thmogh-
cvi the world T«« fUiolnv jtoirl tapes, calibrai«d in mmtm*„ extendi fhuo. «tllter
t»Ae id tlie mam bounnff up to a EotaJ dialaDCtt lof 132 f««t iw 3.S at <Mptf*tivn
J-'i It, l*^f*li* ei fQtjrprapylcnr lupc Mlaciwd L^ mcb Lupr prmuts instalUtK^
to fHtes, tRci. buildiiaif* • hcsc^ «r is awaiiablr Ibr Fomunc a tioubki aniiHiaa tefUgm
'-^ — vitd m tIui Ikifli miyci hmaing u > frequanc^ Is length nnnrcfalfWi dHift
^t«d tjs Rirtar ■!<— irenaiiti on tlir tapn raaltaa nntaJlatioQ btijraai. Faidi wiili
SI oiub OE«K. Di;hlif«n outwaivlran: perfkvniaiKC ML « portabte er pensanait xEiiialliiiion
MeosufEi lpKSHk:2 IftfKiTB rrUsOed. Wt., 4.1 Ibi.
Ordef No. 22& Prio 59436
^IhjHlAffi
ALL NEW
3-BAND,
2 ELEMENT
HY-QUAD
l« *v^ full
a Nibf* lit irit«f qMAiiUufcli*
a H^ Mr«B^, !■* mpid liad
f W H» g^rf fffWH ItT^^BA mifen j« wrbt* 4|«4i vtma/ktt*
Ini. ri i iht 'HAf iftM lhi>l ■ «Ha|ltlr Tlwir m nerttt*^
ivvvMllt. It «& wmfiidi- il«ufiKil fev tht< tt o^mvaima iD fd Itv pir»itMrif
■Mdmnlilf' f r«l urri iiilirKnl ■« quvdi
Hit M\ •luiTHnHrn ttrw^wc titt-x- up' tht fMffr f*t4 linr iM^d dpiAnmd i4i*vf
Hv Ciiri « '14 It* H^-Qiuid W'tn uii1ilt:iill ollm qUiAibmuM if% mfwic*ir4
Lu du ^UlJ ikVJ Tfac H\-0'liail l» M*>«<. irL Mt|I4fd(ll, ll l^rURl^EtE. h\ lllF tlllt
l]iiud III h|w Fvr;|>lliiii|r %pT».|lerih>ir |h uk^m l^fVJII ttfill'tl^ 'If^fii^*' J^l^Ol
wiil|( t:^4r'nkl4^ jnnuNl urni / iri-bnnd ! ekn'Ki'ili ^Oitiilruti'licjiri v^iiIl incllviiliiitLy
fv^fntiUfd ffleMinnH *mi rw lolrrjii'lUjM / Hir-Ut44il iKujuifti nulir "Tf I'^il I't^^
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HMt l^i" 14 lli'^' m tlaaTnrEcr ? tIttRnAUm tiriad»id Mrg>ff. Ycm cin oprn iMl
Lliif* iIh faaiKlK wtih I mi BRicnmi. ttfm'UfupirmwKr ika rbnti ol rtd Dl^t
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Brian E, McAnhur VESCGE
67 Nan wood Drive
Brampfon, Ontario
Canada L6W IMl
PCs Are Easy
step-by-step details
The vast decrease in the
cost of integrated cir-
cuits over the past five
years has opened a totally
new frontier for the elec-
tronic experimenter. Maga-
zines, such as this one. of-
fer a multitude of projects
designed to whet the ap-
petite of the most reluc-
tant builder. These articles
invariably offer schematic
diagrams, parts lists, sup-
pliers, and full or half-size
printed circuit board lay-
outs. Herein lies the crunch
of the printed circuit
board.
The avid experimenter,
through frustration, usual-
ly ends up buying a com-
mercially-made printed cir-
cuit board at a rather high
price. This will obviously
yield the desired result, a
good-looking finished
product. There is not, how-
ever, the self-satisfaction
of having done it alt by
one's self.
An alternate and less ac-
ceptable method is to at-
tempt to hard wire every-
thing on the back of a
piece of vectorboard. (Vec-
torboard is made of a
non conductive material
which has prepunched
holes so that component
leads may be passed
through and soldered on
the other side of the
board.) I cannot think of
any reason why the com-
pleted project should not
work well, if reasonable
care is taken in parts layout
and soldering. Aesthetical-
ly, however, it leaves much
to be desired.
Where do you go from
here? There is only one ob-
vious step, and that is to
make your own.
Before I get into actual
construction methods, per-
haps I might discuss briefly
just what is involved in
making a printed circuit
(PC) board.
The basic PC board is
composed of a thin layer of
copper coating on one or
both sides of fiberglass or
other nonconductive mate-
rial. To obtain the desired
circuit layout, it must be
reproduced on the PC
board using some type of
"resist." (Resist is the
coating which inhibits the
etching process.) Once you
have a perfect layout, the
unwanted copper between
the traces must be re-
moved This process Is
called "etching.'' Ferric
chloride solution is most
commonly used and will
remove the unwanted cop-
per in short order. All that
remains then is to clean up
the board, drill a few holes,
and solder on the compo-
nents. Sound easy? It is,
Well, almost that easy!
There is still one big prob-
lem: How do you get
the circuit onto the board
before you etch it?
There are two answers to
that question. The circuit
layout can either be drawn
onto the board or it can be
done photographically.
Both of these methods will
be covered later in this arti-
cle.
Procedure
To begin, there are four
basic steps in the manufac-
ture of circuit boards:
Step 1 : Procure the
blank circuit board.
Step 2: Reproduce
the circuit board lay-
out on the board with
resist
Step 3: Etch the PC
board.
Step 4: Clean and drill
the board.
Now, let's deal with each
step in turn and get down
to the how-to-do-Tt stage.
First, you must obtain a
piece of blank circuit
board of sufficient size for
your project. Size is not as
important as the thickness
of both the copper and the
insulating backing. Thin
copper will etch off much
faster, which is helpful, but
it may not withstand as
much heat during solder-
ing. The thickness of the
board must be considered
when mounting heavy
components such as
transformers, etc. You do
not want a warped board!
Having satisfied yourself
as to the choice of board,
the next step is to clean it
before applying the resist*
[I cannot emphasize
enough that the board
must be clean!) The sur-
face should be scoured
thoroughly using a steel
wool soap pad. Absolutely
all of the oxidation must be
removed and the board left
in a bright, shiny condition.
After scouring, the board
270
must be rinsed thoroughly
under hot tap water to
remove any soap residue.
Dry it with a clean, soft
cloth, being careful not to
touch the surface with
your hands as this will
leave an oily film which
could affect the applica-
tion of the resist.
Setting the clean board
aside temporarily, you
must decide which method
to use in applying the
resist. There are two
choices available — the
freehand and the photo-
graphic methods.
The freehand method re-
quires that the connecting
foils be drawn on the clean
board by hand with a resist
pen. Positioning your copy
of the full-size layout on
the blank circuit board and
fastening it securely with
Scotch^J^ tape, still being
very careful not to touch
the copper, take a sharp
center punch or awl and
gently, very gently, mark
all of the holes by punch-
ing through the paper.
When this has been done
and the paper removed, a
clear mark should be left
where the components will
eventually be positioned.
From now on, the neatness
of the board is determined
by how carefully the marks
are connected. The holes
should not be drilled now
since the etch ant could
undercut around them and
ruin your efforts. For the
very fine lines, a resist pen
is recommended. This
looks very much like an or-
dinary magic marker; how-
ever, the ink is resistant to
ferric chloride solution.
These pens are not really
suitable for the larger areas
for which resist is sold in
bottles and applied with a
brush. Every area of cop-
per you wish to retain must
be thoroughly coated with
resist. It isn't necessary to
use commercially-sold re-
sist, since many pens of the
waterproof- ink variety will
work just as well, as will
nail polish, for the larger
areas.
At times, it gets difficult
to draw fine lines and in-
tegrated circuit patterns
which are very small and so
often required. There are
all types of decals, rubber
stamps and drawing aids
sold to help with this prob-
lem. For the larger and less
complicated circuits, this
method is best because it is
quick and does not require
a lot of equipment, just pa-
tience and a steady hand.
The biggest drawback to
this method must now be
apparent.
What do you do, though,
if a full-size layout is not
available? A very compli-
cated circuit can become a
nightmare! Now is the time
to investigate the photo-
graphic method.
Assuming that everyone
at one time or another has
seen a black and white neg-
ative, you should realize
that it is really not black
and white at all, but mostly
made up of varying tones
of grey. This is not good
enough for these purposes.
What you need is a full-size
negative of only two tones,
black and perfectly clear.
This is accomplished by us-
ing lithographic film. Com-
mercially, it is sold by
Kodak (Kodalith) and II-
ford (llfolithL both of
which will serve your needs
if the manufacturer's di-
rections are carefully fol-
lowed when using these
films.
The first step in making a
full-size working negative
is to take a black and white
picture of the circuit board
in the magazine with a
camera and close-up at-
tachment. The layout must
be kept perfectly flat and
the camera level and paral-
lel to it, Care in this part of
the procedure will keep all
of the lines in their proper
perspective and to scale.
One magazine (that I
know of) does not give a
true black and white cir-
cuit layout. Instead, they
use grey, and show the
components overlaid in
red ink. This does not pre-
sent much of a problem.
Simply by placing a deep
red filter over the camera
lens, presto, the com-
ponents disappear and the
grey lines appear black. Be-
cause you need the small
negative to make the big
one, your film has to be
processed. The next steps
require the use of an en-
larger and darkroom, so
now is the time to enlist the
aid of the local camera
club if this equipment is
not readily accessible.
You now progress into
the darkroom where you'll
be using the special "lith"
film mentioned earlier.
Lithographic film requires
special safelights and de-
veloper, so following the
manufacturer's directions
is a must. Placing the nega-
tive into the enlarger, pro-
ject the image onto the
easel and focus it perfect-
ly. You must project the im-
age the exact size of the
printed circuit board you
desire, or none of the com-
ponents will fit. This is
quite easily accomplished.
Simply place the full-size
magazine layout, photo-
graphed earlier, under the
enlarger and adjust the
projected image until both
are exactly the same size.
If the layout was only half
scale to begin with, you
will have to measure the
size of some known com-
ponent and adjust the im-
age to suit. The enlarger is
switched off and the maga-
zine layout is removed
from under the enlarger and
replaced with a piece of
lithographic film. Exposure
for the film may vary, but a
figure of thirty seconds is a
good starting point. The ex-
posed film is placed in the
developer for about one
and a half minutes, stop
bath for fifteen to thirty
seconds, and then fixed ac-
cording to the instructions.
Before turning on the
lights, you must put away
the rest of the lith film. The
wet full-size positive must
now be washed and al-
lowed to dry.
The next part of the pro-
cess is relatively easy.
After the full-size has
dried, you can make the
full-size negative that you
were after in the first place.
The positive is placed on
top of a sheet of lith film
(again in the darkroom) and
a clean sheet of glass
placed on top. The glass
will keep everything flat,
while you make a contact
negative by exposing the
film to light,, A 60-Watt
lamp held two feet above
the film for 15 seconds is
approximately the right
amount of time, The film is
processed as before, and,
while it dries, carry on with
the next step, the prepara-
tion of the circuit board.
In order to transfer the
image of the full-size
negative to the circuit
board, you must first coat
it with "etchant resist sen-
sitizer." This type of resist,
available in an aerosol
spray can, when deposited
on the circuit board, makes
it sensitive to light much
like a photographic paper,
except in this case it is
most sensitive to ultra-
violet light. The spraying of
the circuit board must be
done in the darkroom
under a safelight with ade-
quate ventilation. Starting
from the bottom, spray the
board evenly, holding the
can about 5 to 8 inches
away. The resist looks like
a thin lacquer with a
purplish tint to it. The ex-
cess is allowed to run off
by holding the circuit
board vertically by the
edges. Now put it away to
dry overnight, somewhere
where it will not be ex-
posed to light.
The time has now ar-
rived to expose the circuit
board to ultraviolet (UV)
light. Carefully, the full-
size negative is placed
over the treated circuit
board in the darkroom and
covered with the sheet of
glass to hold it flat. In order
to expose it to ultraviolet
light the board should be
placed outside in the sun
271
^^
about one and a half
minutes or under a sun
lamp. (I use a sun lamp
about 18 inches above the
board and expose for 1
minute.)
The PC board is brought
back into the darkroom
and developed in ''photo-
etching developer/' This
chemical dissolves the
resist which was not ex-
posed to UV light. After
careful washing, the board
is allowed to dry. (For safe-
ty's sake, read and follow
all instructions on both the
resist and developer con-
tainers because they are
both highly toxic and
volatile chemicals requir-
ing a lot of ventilation.)
After taking one last
look and possibly touching
up an area or two with the
resist pen, you now are
ready to actually etch the
circuit board using ferric
chloride solution. (Take my
word for it, ferric chloride
solution is a highly cor-
rosive substance which will
eat its way through the
copper, the concrete floor,
or, as 1 found out the out-
side of my wife's washing
machine. Wear gloves artd
eye protection, and follow
the instructions to the let-
ter!)
Having chosen a glass
tray, not metal, of ap-
propriate size, pour in the
ferric chloride solution to a
depth of about three
quarters of an inch. The
solution is used at room
temperature and, again, in-
halation of the fumes
should be carefully avoid-
ed. The PC board is placed
into the ferric chloride
solution face up and
agitated gently by raising
and lowering the tray
about one inch. The etch-
ing process will take
about one half hour, so pa-
tience is the key word here.
When sufficient time has
elapsed, the PC board is
removed from the solution
and the etchant gently
washed off under running
water. By holding the
board up to the light, you
can see if all the unwanted
copper has been removed.
If not, replace the PC
board in the etchant and
continue agitation. The
completely-etched board
will have to be scoured
with the soap pad again to
remove all the resist. There
are chemical removers, but
this is the easiest way and
makes the board easy to
solder, too.
Steps 1 , 2, and 3 were the
hardest, and drilling the
board is child's play in
comparison. The only trick
here is to use the correct
size of drill bit (see the drill
guide in Table 1) to fit the
electronic components. A
drill press is an asset.
although not a necessity; a
little care will go a long
way.
All of the items used in
this article are available in
most areas from the local
electronics supplier. The
resist, developer, and etch-
ant will run about $15.00,
but that will do many,
many PC boards. The
lithographic film costs
about $30,00 for fifty 8" x
10'' sheets. It is definitely
more expensive to make
the PC boards photograph-
ically, but the results cer-
tainly justify the expense if
more than one board is go-
ing to be made.
Thus, with a little time
and effort, home manufac-
ture of printed circuit
boards can be both rela-
tively easy and definitely
self-satisfying. ■
Number 65 drill
Number 60 drill
Number 56 drill
#20 AWG wire; Molex pin; V4-Watt resistor
V2-Watt resistor
1' or 2'Watt resistors; IC sockets
7ab/e 1, Drill guide.
New Products
from page 2S2
The 122"'long vertical ele-
ment and four 14^4"-long
radiaJs of the G 7-220 are made
from high-strength heat-treated
aluminum. Each radial has a
3/16" o.d. The G7-220^s N^type
connector, used on all new
Hustler amateur verticals, pro-
vides a tight all-weather seal
and virtually perfect rf charac-
teristics under all conditions,
The G7-220 weighs only 7
pounds, and is easily mounted
on any capable vertical support
of up to IV4" o.d. The wind
loading of the antenna is only
26 pounds at 100 mph veloci-
ties.
For further information on
this or other Hustler products,
write: Sahs Department, New-
Tronics Corporatfon, 15800
Commerce Park Drive, Brook-
park OH 44142. Reader Service
number N2.
B ELD EN INTRODUCES TWO
NEW LOW-NOISE COAXIAL
CABLES
For high-Impedance appiica-
tions, including test leads and
instrumentation, Beiden Cor-
poration's Electronic Division
has introduced two low-noise
coaxial cables.
The two are a 1 74/U-typ6 with
26-gauge stranded conductor
(no. 9239), and a SWUtype with
a 22-gauge solid conductor (no.
9224). Construction details in-
clude bare copper-covered
steel conductors, polyethylene
insulation, and a conductive
layer. Shielding for the 9224 is
an 88% -coverage tinned cop-
per braid; for the 9239, it's a
bare copper braid with 93%
coverage. Both utilize a black
vinyl jacket with overall
diameters of .101 inch (9239)
and .242 inch (9224).
Electrical specifications:
nominal capacitance — no,
9239, 39.3 pF/fi,; no. 9224, 21
pF/ft.
Both low-noise coaxial
cables are available in 100-,
500-, and 1,000-ft. putups; no,
9224 also is available in
Unreel^^-packed 500- and
1,000-ft. lengths.
For additional information,
write: Manager, Marketing Com-
munfcations, Beiden Corp,, 2000
S. Batavia Ave., Geneva iL 60134.
Reader Service number B41.
NEW DUAL OPERATIONAL
AMPLIFIER FROM SIGNETICS
OFFERS LOW NOISE AND
WIDE BANDWIDTH
A dual low-noise general-pur-
pose operational amplifier of-
fering a wider bandwidth and
Improved output drive capabili-
ty compared to standard op
amps is now available from
Signettcs.
Designated the NE6633, the
device is capable of driving 10
V (rms) into 600 Ohms directly
and features a small-signal
bandwidth of 10 MHz and
power bandwidth of 200 kHz;
The 5533 is internally com-
pensated for gain equal to or
I i
2 2
k J
'^ * K
i^ ■-■Jy^^r I -1
higher than +3. Frequency
response can be optimized with
an external compensation ca-
pacitor for applications requir-
ing it.
Other specifications of the
5533 include: dc voltage gain,
100,000; ac voltage gain, 6,000
at ID i<;Hz; and supply voltage
range, ±3 to +20 V. The 5533
comes in a standard 14-pin
dual-in line package.
For further information, con-
tact: Guy Caputo, Industrial
Marketing Manager, SignetlcSt
81 1 East Arques Avenue, PC
Box 9052, Sunnyvaie CA 94086;
(408^739-7700. Reader Service
number S70,
t
2
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272
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273
Merwirt Updyke WB3EUG
609 Belt Avenue
Aiioana PA 16602
The Games People Play
why not hams?
Pldyirig games on ham
radio is nothing new.
There is almost always
someone on the air who
will play, dnd the element
of radio communication
adds a new twist to any
game. A good ham game
could liven up dead bands,
fill those extra hours, pro-
vide excellent opportuni-
ties for those who are not
particularly given to rag
chewing or new "mike shy"
hams, give use to little-
used 2 meter simplex chan-
nels, and possibly even
make some new "wall-
paper" available for
award-conscious oper-
ators.
But good ham games
have been few and far be-
tween. To be well used on
the air, a game should
fulfill alt or most of the
following requirements:
The ideal ham game must
1) be easily played by two
people, 2) be able to be
played with only a paper
and pencil as well as on
commercial game boards,
3) have rules that are sim-
ple and can be easily given
over the air to someone not
at all familiar with the
game, 4) be able to be
played in a relatively short
time, 5) have individual
moves or plays that can be
executed in a short time,
and 6) be challenging and
contain logically varying
degrees of difficulty to en-
sure continued interest and
allow advancement in
playing skid.
After 1 found two games
that met these re*
quirements, a topical CQ
of "CQ game, CQ for a
game" brought hours of
challenge and enjoyment.
Why not give them a try
yourself?
Game #1
This one is my favorite
and, of the two, holds the
most promise for a game
that will be played on the
air for years. Master
Mind® by Invicta Blastics,
Ltd,, is a new game that has
won tremendous popular-
ity throughout the world.
There are even British
National Master Mind
Championships held year-
ly. It is said to be 80% logic
and only 20% luck, is inex-
pensive to buy in its attrac-
tive game board form,
can be played almost
anywhere (even comes in a
pocket-size board good for
field days, etc), and comes
with instructions in ten
languages.
Rather than give more
details of the game, the
following is offered as an
explanation suitable for
use on the air with a person
who has no knowledge of
the game. You may want to
make a few changes, but I
found this order to work
well. These rules are
designed for convenient
use of the board by I nvicta.
After calling "CQ game"
and having secured a
promise to at least give it a
try, give the following in-
structions:
1, Secure a piece of
lined paper and a pencil or
pen.
2. There are 6 colors.
Write down "R" for red,
"W" for white, "Bu" for
blue, "C" for green, "Y" for
yellow, and "Bk" for black.
3. Number down 10
lines, starting with 10 and
ending with one
4. Above these 10
lines, write a 4-color code
of any combination of the
6 colors. For this first game,
do not repeat a color; use
four different colors.
5. Starting with line
one. I will try to break the
code. I will give you a
4-color code. Write it
down. Then give me a
rating of "Xs" and "Os,"
Write on your paper "X" =
right color and right place;
"O" = right color but
wrong place.
If I have two reds, for ex-
ample, but your code has
one red, I get only one ''X"
or ''O", depending on posi-
tion. The order you give me
the "Xs" or "Os" is not to
show anything about the
274
order of the ones I have
right.
6. I have up to ten tries
to match your code. The
winner is the one who
breaks the code in the least
amount of trys. Any ques-
tions? My try for line one is
. What is my
rating?
7. When he gives a
rating, say 'That means
..." and explain the rating
to be sure he understands.
A condensed form of
these rules for quick
reference is found in Table
2. Both players should be
keeping track of the entire
game on a board or paper
(the board is generally
easier). After you break his
code, make one for him,
and the play goes on You
will find that it helps to
"think out loud' over the
air.
The sample game in
Table 1 should help you to
better understand the
above instructions. Try to
break the code on the next
try. The answer is at the
end of this article,
If your experience runs
like mine, you'll find your
opponent saying, "Once is
not enoughr', and the
minutes will quickly and
enjoyably pass by. Hope-
fully there will soon be
many on the air who have
played a few times. That's
when the many variations
keep the game going
strong. First remove the
restriction that all the col-
ors must be different. You
can make the code all one
color if you want. Next you
might want to change the
number of possible com-
10
9
r
6
5
4 W R By G 00
3 R Bk G By OXX
2 Bu G Bk Y 000
1 G W Y R COX
7ab/e 7. Sample Master
Mind game.
bin at ions. For young
children, you may want to
make it three positions and
only four colors. But you
will most likely want to in-
crease the number of possi-
ble combinations. The
regular Master Mind game
(the one just explained) has
1296 permutations, but, by
allowing an empty space to
be played as a color
(designated with an "S" on
the air), it increases the per-
mutations to 2401. Those
who expect to enjoy this
game and want to further
develop their skills may
want to purchase the Super
Master Mind version of
the original (also by Invicta
Blastics, Ltd.). It can be
played as the version ex-
plained above, but allows
for a game with 5 positions
and eight colors (orange,
''O", and brown, 'Br", are
added), allowing 1 2 tries to
find the one of 32,768 (or if
space is used, then one of
59,049) permutations in the
code. (Note: The formula
is: no. of permutations —
CP, where C = no. of col-
ors and P ~ no. of posi-
tions.) Other interesting
variations, such as allow-
ing the codemaker to
make one incorrect rating
during the game are of-
fered in Modern Board
Games, edited by David
Pritchard and published by
William Luscombe Pub-
lisher, Ltd., which should
be available at your local
library.
Developing strategies is
an important part of the
game and is necessary for
the more advanced games.
Also, the codemaker can
learn to play more of an ac-
tive role as he analyzes his
opponent and tries to
psyche him out with little
1. Secure paper and pencfL
2. Colors = R, W, 8u. G. Y, Bk.
3. Number 10 lines.
4. Write down code.
5. Rate each try "X ' or "0'\
6v Review rating given.
Table 2. Master Mind in-
structions.
"extra comments/' The
history of the game and its
tremendous popularity
make interesting rag chew-
ing. All this, plus discussion
of tournaments and many
more topics (with even a
short chapter on com-
puters that play Master
Mind), can be found in The
Official Mastef Mind Hand-
book by Leslie H. Ault,
published by Signet. It's a
must for the serious Master
Mind.
For those who desire
more practice, a computer
pocket calculator-type
game that will play against
you is offered by Milton
Bradley Co. under the
name Comp IVTM Yqu cgp
play this with up to 5 posi-
tions and 10 choices. Cost
is around S25.00.
This game presents a
golden opportunity. Why
not have some awards for
the Master Mind ham?
How about WM-20— won
Master Mind in 20
states — or, for real
operators, WMAS — won
Master Mind in all states?
Perhaps a grueling
challenge would be MDX-
15 — Master Mind played
DX in 15 countries— or the
ultimate; MDXCCl Well,
anyway, it would be great
to see some enterprising
ham advertising saying
'^Send $1,50 with a log
to . _ " for some sort of
Master Mind or game
award. Perhaps a common
frequency could be
chosen.
Who knows, maybe
there will even be some
''Mind nets'' and "tour-
naments in the air" and
. . . better get on to the
next game.
Game #2
Here is another game
that meets most or all of
the requirements previous-
ly stated. Those who tire of
Master Mind [devotees say
that this is impossible] may
find that this game offers
the variety needed to
spruce up their ham game
venture. This game, which
is also offered in plastic
under various names (Tri-
Tac-Toe at )C Penney for
$6,951 is a complex varia-
tion of tic-tac-toe I call Tri-
Tac (for three-dimensional
tic-tac-toe).
Following are two varia*
tions of the game, the sec-
ond being the more dif-
ficult The first game re-
quires 3 in a row, the sec-
ond requires 4 in a row. The
rules are the same as in
regular tic-tac-toe, except
that those in a row can be
on different levels. Letters
and numbers provide easy
coordinates for positioning
^'Xs" and ''Os" over the air.
In the examples given in
Fig. 1, 1 use the letters a, b,
c, and d to show winning
combinations. Study them
and try to imagine them
stacked up in layers to
form a cube.
For the first game, the
person challenged goes
first; thereafter, the winner
goes first The challenged
calls coordinates to place
275
(
2
s
1
2
S
4
A
b
b
k
B
b
B
a
C
L
c
c
.0
a
D
E
■
F
E
a
F
c
b
G
L
a
H
a
H
{l
1
k
ii
i
c
K
L
a
c
b
1
M
■
fl
N
0
P
d
tt
d
d
C
tF
Fig. 1. Trf-Tac.
his ''O", the challenger
calls coordinates to place
his "X", and so on, until one
person gets his required
number in a row and is thus
the winner.
You may want to write
down a list of instructions
to be given over the air for
Tri-Tac, as was done for
Master Mind.
Yet another variation
that can be played on the
four-grid version would be
to give each player two
markers ^to one, ''W" and
'X; to the other, "Y" and
"Z" — allowing for either to
be played at any time. The
first to get four of one of
them in a row wins. Or try it
as the first to get both of
his markers four in row is
the winner.
Again, some Tri-Tac en-
thusiast should offer a few
awards as for Master Mind.
Will you accept this
challenge?
I hope you enjoy these
ham games as much as I
have. When playing, keep
the individual plays short
repeat plays and instruc-
tions often, think out loud
so as to occupy the fre-
quency, and watch that
10-minute timer for ID.
Even if no one offers
awards, you may want to
keep a notebook of all
your games, times, etc., for
review and strategy devel-
opment.
''Okay, my first try is W,
Bu, Y, R. What's my
rating?''
(By the way, the answer
for the sample Master
Mind isY, Bk, G, R. It is not
one of the most simple you
will run into,)B
Editor's note:
i enjoy Master Mind
enough so that Sherry and I
take one along on trips and
use it during plane rides to
while away the time. Super
Master Mind has eight col-
ors of pegs and five holes,
making it even more
demanding than run-of-the-
mill Master Mind.
Then you can play the
same game with words.
Thirik up a real stinky four-
letter word and use the
same system for playing-
This takes no equipment at
alt other than a pencil and
pad. Sherry and I have
played this while driving.
Card games have been
difficult to play over the
air . . . obviously. But wrfh
the advent of microcom-
puters which can shuffle
and deal cards for us,
perhaps the day of the over-
the-air gin rummy game is
not that far of f. If any group
gets going with this and gets
porky about their prowess
at cribbage, ril be on. fre-
quency to challenge.
Computers can throw
dice for us, too, making
backgammon possible.
Please be sure to let 73
know if you get involved
with this sort of mischief.
Oh, if you would tike
some rotten words for
Word Master Mind, you
might try: BUNK PUMP,
LULL, XRAY, }AZZ, FIZZ,
FLOX, etc. -Wayne.
YEARS WARRANTY!
EXACT Replacements for
SYLVANIA •*^**
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MA
.94
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276
W2NSD/1
HEVER SAY DIE
editor/at/ by Wayne Green
from page 255
able to take a simple business
trip and, for less than the
regular fare, fly anywhere In the
Eastern system , . . and this in-
cludes such interesting DX hot
spots as Saint Martin {which is
two countries!), Martinique,
Trinidad, and a lot of other
great Caribbean islands.
Write ahead and get your
license from the Department of
Telecommunications. If you
wait until you get there, you
may find yourself up against
several days of red tape, and be
back home before the ticket
comes through.
Here*s the only border be-
tween the French side of Saint
Martin and the Dutch side,
Saint Maartens, It's just a
marker alongside the road, and
you have to keep your eyes
open to see it.
You'll find that there are
other demarcations between
the two countries when you try
to make a phone call from the
Dutch side to the French. Good
luck in dealing with the French
operators ... if they get off
lunch break.
We could use a lot more ac-
tivity in the islands^ so check in-
to the Eastern fares and see if
you can't activate an island for
a few days and find out why
some hams get so addicted to
DXpeditioning. With the cur-
rent line of tiny rigs, you can
carry one along, complete with
antenna, right under the plane
seat.
The Eastern fares have
substantially changed the
economies of the Islands, so
youMI want to be sure to reserve
your seat well ahead of time
and make sure that you have a
-S' :•
1'
r , "
■AUK ^
hotel reservation, complete
with permission to use your
ham rig and antenna, YouMI
want to save up some money,
too, for the boom in Caribbean
travel which has resulted from
the Eastern fares has also
jacked up the costs of hotels,
food, etc.
AUGUST WINNER
"Ham Radio Is NOT A R*ch
Man*s Hobby"? Rick Ferrantf
WA6NCX/1, author of August's
most popular article, will find
himself fn a slightly higher in-
come bracket this year, thanks
to the $100 prize our readers
voted him with their Reader
Service card ballots. Rick, we
suggest you drop the hobby or
stop writing crackerjack ar-
ticles for 73 — or it will be a rich
man*s hobby for you.
Ham Help
I am a public school teacher
at the Pine Point Experimental
School on the White Earth In-
dian Reservation in Minnesota.
The school is the main focus of
the Pine Point community, and
is involved with preschoolers
through adults.
There is much interest on the
part of the students and com-
munity m general in com-
munications, and many stu-
dents are excited about study-
ing for their amateur radio
licenses and starting a ham
club. Interest was spurred by
the CB club we started last
spring, but the sunspot cycle
put the iid on legal 11 meter
communications during the
school day. The motivation and
built-in incentives in ham radio
would serve an important func-
tion here, especialty during the
long and frigid winter.
In addition, the Tribal Coun-
cil has been talking of a future
Chippewa radio station to
cover the reservation, and ham
radio would be the seed from
which engineers and techni-
cians could grow.
ff any individual, organiza-
tion, or company could provide
the school with worki ng station
or test equipment, learning
aids, etc., new or used, donated
or at low cost, please contact
me at the school.
Walter Kfmmel KBOCB
Fine Point Experimental
School
Ponsford MN 56575
1 need a diagram or Informa-
tion on a 2 meter 1 W-in/10
W-out amplifier. The circuit
board has #85-1661^091974-
080674 printed on one side and
the other side has #85*1 66M
plus 2 other numbers. A thick
aluminum panel has #203-1466
stamped on it. It uses one
2N5589 and one 2N5590. H has
a 4PDT, 12-volt relay built-in on
the board, I am also missing
coils L304 and L305. Can
anyone help? I will pay you for
whatever is needed to copy the
info.
Jung Y. Lem KB6B0
5222 Coringa Dr.
Los Angeles CA 90042
I need a manual or schematic
for a Swan 11 7B (117 V ac)
power supply. Thanks.
B. Mongeau
2215 Marie Victorin
Sillery, Quebec
Canada G1T 1J6
I am in need of a schematic
diagram for a Royal Canadian
Navy transmitter-receiver, type
FR-12-PH 05161-PH, The rating
is 12 V do 6 A cont., 11 A int.,
spec, is 122904, and it was
manufactured in 1944 by the
Canadian Marconi Company.
Also, I would like the address of
the Canadian Marconi Com-
pany in Canada, if at all possi-
ble.
Emil Sohuchardt, Jr.
21 East Clark St,
Springfield OH 45506
277
OSCAR Orbits
Oscar 7 Orbilal Information
Oscars Orbital Information
The listed data tells you the time and place that OSCAR 7 and
OSCAR 8 cross the equator in an ascending orbit for the first time
each day- To calculate successive OSCAR 7 orbits, make a list of
the first orbit number and the next twelve orbits for that day. List
the time of the first orbit. Each successive orbit is 115 minutes
later (two hours !ess five minutes). The chart gives the longitude of
the day's first ascending (northbound) equatorial crossing. Add
29* for each succeeding orbit. When OSCAR is ascending on the
other side of the world from you, it wilt descend over you. To find
the equatorial descending longitude, subtract 166"" from the
ascending longitude. To find the time OSCAR 7 passes the North
Pole, add 29 minutes to the time it passes the equator. You should
be abfe to hear OSCAR 7 when it is within 45 degrees of you, The
easiest way to determine if OSCAR is above the horizon (and thus
within range) at your location Is to take a globe and draw a circle
with a radius of 2450 miles (4000 kilometers) from your QTH. If
OSCAR passes above that circle, you should be able to hear It Jf it
passes right overhead, you should hear it for about 24 minutes
total. OSCAR 7 will pass an Imaginary line drawn from San Fran-
cisco to Norfolk about 12 minutes after passing the equator. Add
about a minute for each 200 miles that you live north of this tine. If
OSCAR passes 1 5 * east or west of you, add another minute; at 30 ^
three mmutes; at 45', ten minutes. Mode A: 145.85-.95 MHz uplink,
29.4-29.5 MHz downlink, beacon at 29.502 MHz. Mode B:
432.125-.175 MHz uplink, 145.975%925 MHz downlink, beacon at
145,972 MHz,
OSCAR 8 calculations are similar to those for OSCAR 7, with
some important exceptions, Instead of making 13 orbits each day,
OSCAR 8 makes 14 orbits during each 24-hour period. The orbital
period of OSCAR 8 is therefore somewhat shorter: 103 minutes.
To calculate successive OSCAR 8 orbits, make a list of the first
orbit number (from the OSCAR 8 chart) and the next thirteen orbits
for that day. List the time of the first orbit. Each successive orbit is
then 103 minutes later. Due to incorrect tracking information ob-
tained during the early days of OSCAR S, the equator crossing
times contained in most published charts are in error- To correct
this error, multiply the orbit number by 0.00205 minutes and add
Orbit
Date
Time
Longitude
Orbit
Date
Tirrt&
Longitude
{Dec)
(GMT)
Cmseing ^W
(Dfic^
(GMT)
of Eq.
1^495 Bbn
1
0009:15
62.7
3771 Abn
1
0111:17
59,6
1&50BAbn
2
0103L32
76.a
3766 Jbn
2
0116:29
60.g
1S520Bbn
a
0002:53
©12
3799 Jbn
3
0121:39
62.2
13533 Bbn
4-
0057:10
74.8
3613 Abn
4
0126:50
63.5
185^6Abn
5
0151:27
88.3
3627 Abn
5
0132:01
64,8
l355S8bn
6
0050:48
73.2
3841 X
S
0137:12
66.1
18571 Bbn
7
0145:05
see
3355 Abn
7
0142:24
67.4
18563 Ahn
8
0044126
71.6
3868 Abn
8
0004:21
42,9
Ifl596 Bt>n
9
0136:43
85,2
3882 Jbn
,9
0009:32
44.2
lS60BBl>n
10
00313:04
70.1
3696 Jbn
10
0014:43
45.5
1 6621 Abn
11
0132:21
83.7
3910 Abn
11
0019:54
46,8
13633 Bbn
12
0031:42
esj
3924 Abn
12
0025:05
46,2
18646 Bbn
13
0125:59
82:1
3936 X
13
0030:16
49.5
18658 Abn
14
0025:20
67.0
3952 Abn
1^
0035:27
50.8
18671 Gbn
15
0119:37
80.5
3966 Abn
15
0040:33
52.1
18683 fibn
16
0018:5T
65.4
3980 Jbn
16
0045:49
53.4
18696 Abn
17
0113:15
79.0
3994 Jbn
17
0051:00
54.7
16706 Bbn
18
0012:35
63,8
4008 Abn.
18
0055:11
56;o
larai Bijn
19
0106:53
774
4022 Abn
19
0101:22
57.3
13733 A bn
20
0006:13
62.3
4036 X
20
0106:33
58.6
18746 Bbn
21
0100:31
75.9
-^050 Abn
21
0111:44
59.9
18759 Bbn
22
0154r4B
895
4064 Abn
22
0116:54
61.2
18771 Abn
23
0054:08
74.3
407B Jbn
23
0122:05
62.6
18734 Bbn
24
0143:26
a7.9
4092 Jbn
24
012;^:16
63.9
18796 Bbri
25
0047:46
72.S
4106 Ahn
25
0132:27
65.2
iae09 Abn
26
0142:04
BS.3
4120 Abn
25
0137:38
665
18821 Bbn
27
0041:24
71.2
4134 X
27
0142:49
67.3
16834 Bbn
28
0135:41
84.6
4147 Abn
26
0004:46
43.3
1 8646 Abn
29
0035:02
69.6
4161 Abn
29
0009:57
44.6
13359 Bbn
30
0129:19
832
41 75 Jbn
30
0015:07
45-9
18671 Bbn
3t
0026:40
66.1
4189 Jbn
31
0020:18
47,2
the result to the equator crossing time as printed in the chart. For
example, the published time tor orbit number 3352, the first
equatorial crossing on November 1, 1978, is0018;50 UTC.Thus, for
orbit number 3352, the corrected equatorial crossing time would
be:
Corrected time = 0018:50 + (3352 x 0.00205 minutes)
= 0018:50 + (6.8716 minutes)
= 0025:42,3
The longitude figures contained in the OSCAR 8 chart are virtualfy
unaffected by this tracking error. The chart gives the longitude of
the day*Q first ascending equatorial crossing^ Add 28° for each
succeedi ng orbit. To find the time OSCAR 8 passes the North Pole,
add 26 minutes to the time it crosses the equator. OSCAR 8 will
cross the imaginary San Francisco-toNorfolk line about 11
minutes after crossi ng the equator. Mode A: 145.85-.95 MHz uplink,
29.4-29-50 MHz downlink, beacon at 29.40 MHz. Mode J:
145.90-146.00 MHz uplink, 435.20435.10 MHz downlink, beacon at
435.090 MHz.
Canadian Amateur Radio Federation, itic.
DOC PUBLISHES DETAILS OF
NEW "NO-CODE" '^DIGiTAL^'
CERTIFICATE
Changes to the Radio Reg-
ulationSr featuring the long-
awaited details of the new "no-
code" certificate known up to
now as the "experimenter's''
certificate and "packet radio,"
were made public on Septem-
ber 14, 1978. These changes
came into effect September 30,
1978. Holders of the new ticket,
now called the "Amateur
Digital Radio Operator's Cer-
tificate," will be permitted
operation on two meters and
above using various modes of
operation, including pulse
modes. They may obtain an
Advanced certificate after a
year's operation and passing a
15-wpm coda test. Advanced
amateurs may use pulse
modes after passing the rele-
vant portion of the new exam.
The new exams for all three
classes of certificates will start
November 15 of this year.
Packet radio will be permit-
ted to all three classes in cer-
tain parts of the 220-MH2 band.
Along with other modes, It may
be used from 220.1 to 220.5
MH^. An exclusive two mega-
hertz slot for packet radio, only,
is allowed from 221.0 to 223,0
MHz. There are no other
changes In the 220 band which
affect Amateur and Advanced
Class operators. Another ex-
clusive packet radio slot is
from 433.0 to 434.0 M Hz. Packet
will also be permitted on 24.0 to
24.01 gigahertz. For identifica-
tion purposes, packet headers
will carry an ASCII mapping of
the catlsign. Secret codes and
ciphers are not permitted.
Modulation techniques and
emissions for packet radio will
be determined by experiments
undertaken by amateurs
themselves.
Pulse modes PCS and PI are
permitted on two meters be-
tween 145.5 MHz and 145.8
MHz, and P0, PI, P2, and P3are
allowed from 434.0 to 434.5
MHz, with P4, P5, and P9 being
added in the 1215.0- to
1300-MHz slot and in bands
from 2300 MHz on up.
Further changes to the Regu-
lations note that for all classes
of certificates, exams will be
held four times annually, nor-
mally in October, January,
April, and July. Separate
credits for code exams are
good for one year, Muiti pie-
choice questions will remain
for the Regulations portion,
with narrative-type questions
for the theory.
Details of the new regula-
tions and the examination re-
quirements for all three classes
of certificates are contained in
the new DOC bulletins, TRC 24,
effective October 1, 1978^ and
TRC 25, effective September
30, 1978. These may be ob-
tained from the Department of
Communications Regional of-
fices in Vancouver, Winnipeg,
Toronto, Montreal, or Moncton,
or from the Telecommunication
Regulatory Service at DOC HQ,
300 Slater Street, Ottawa, On-
tario K1A oca.
Corrections
Please pass this Information
on to the good people who
were kind enough to read my
article "Sleight of Hand'' in the
August, 1978, issue of 73,
The circuit shown in Fig. 5
on page 77 should not be used.
This is due to the fact that as a
greater load is placed upon the
output, the impedances of the
primary transformer windings
begin to change every halt-
cycle. The impedance of one
primary increases, while the
other transformer primary im-
pedance decreases. This gives
rise to a sharp drop in output
voltage as the load resistance
decreases.
My apologies to anyone who
has tried to make this circuit
work.
Bob May K4SE
Jonesboro TN
We have just received a
belated correction to ''The
Beeper," {January, 1977) which
should allow the unit to func-
tion as intended. It appears
that a lone decimal point mis-
placement transformed C5 to
0.001 uF when it should have
been 0.01 uF.
Gene Smarte WB6T0V
News Editor
278
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This offer good thru
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279
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low tnd 9t b«n# ii ad^DttaWe to anj afaet trMu wnhout t»q4a or
njtttBiQ CFrtq- elart hiifcliiill Can to* vvctf vn lop of ^ji-i^tik-
kr ittKLs ^ ANYWHERE f<^r TRUE CM-POLE rMWlaa * ih*
STANDARD or ALL RADIO ANTCIINAS! POftTABtE -
EAST t« MOVE ■.ml Brcct. W ral hwfhroof -LONli LlTCs
SO reifltar - 125 ft,
40 m«t«f « 6$ rt.
SO flitlaf - 33 ft.
IS ni«tar * 22 tu
No. HD-QO 10 rrttter - f6 fL No. HD^IO
N<t. H0-4O 6 m«tw - 9 fL H*. MD*S
ho HO-ao Cntxcni B- 1? H, Ho.CB^O
No. HD-IS 4d in«4ar 7Tn. No Hl^>49
ANT MODEL No. $13,95 fplui] «2.00 paatJiiia In USA.
{Speckal Froflj. S3.0O more - Adw^i* DiiKct freq. In MHZ - 2 to
ISO) SEND FULL PRICE OR ORDER WITH VISA(Banh-
tmorlcard) MAS TEH CHARGE - AM EXP Glwa Nw. oiid Ek.
Date. Fh I-30H-S3G-5333 DAM-6PM, >iM««1cdBy&. We ihJp
In 2-3 diyi, Ordier naw and t3«at pHce irii:rcaEF - FREE
INFORM ATtON, WESTERN ELECTRONICS
D«m. AT^t^ K««rfiey ,N«bit»hB. GB947 f^ Vtf IS
iSQNVailVHOJSVNNHlNV
280
j^** Bender Servtce — se# pa^ge 323.
$95 MORSE TRANSCEIVER
SEND,
• 1 to 150 WPM Iset from
terminal)
• 32 charaeter FIFO buffer
with editing
• Auto Space on word boundri^^
Grid /Cathode k«y output
■ LED Readout for WPM and
Buffer space remaining
SERIAL INTERFACE:
ASCII a 10. 300, 600, 1200)
or Baudot {45, 50, 57, 74} coin p sit ibie
Simplex HiV Loop or T?L
electrical interface
Interfaces directly with the XITEX^
SCT-100 Video Terminal Board;
Teletypes* Models 15. 28, 33* etc.;
or the equivalent
- MR5-100 CONFIGURATIONS: -
' $95 Partial Kit {includes Microcomputer components
and circuit boards; less box and analog components}
• $225 Complete Kit (includes box, power supply,
and all other components)
• $295 Assembled and tested unit (as shown)
^— Overseas Orders and dealer inquires welcome i^^
COPY:
• 1 to 150 WPM with
Auto-Sync >
• Continuously computes
and displays Copy WPM
• 80 HZ Bandpass filter
Re-keyed Sidetone Osc.
with onboard speaker
* Fully compensating to
copy any 'fist style
See your local dealer or
contact XITEX* direct-
■n
MC/Visa accepted
»XIT€X CORR
13B2H Nt'UtroTi • P. O. Box 402110
Seze- n^oAe & Speneet
Eieeti
ZOHiCS i^S39
1465 WELLS STATION ROAD
MEMPHIS, TENN. 38108
PH (901) 683-9125^685-8461
Authorized Dealer
DRAKE— ICOM^KENWOOD
REGENCY— TEMPO— DENTRON
CALL OR WRITE
FOR BEST DEAL
FLV YOUR RUBBER DUCKY M
Get off the trunk lid and into the best location
on the car , . . the center of the roof t Test^ have
proven that the low profile quarter-wave whip,
or the rubber-ducky from a Handy-Talkv, out-
performs a 5/8 whip on the trunk Take advan-
tage of the super ground plane by converting to
the FLYtNC'OUCKY magnetic rr^ount Although
designed specifically for use with a H-T, it can
be used with any mobile rig. Ten second installa-
tion.
FLVING-DlJCkV rtiagnetic mount consists of;
• Chrome-plated super magnet (holds 50 lbs J
• Compatible coax plugs furnished to match rig
reQuifements, Specify BNC, F type, PL259'
S0239. For TNC Wison type add $3.
• Coax cable lO^ in. long.
FLYING DUCKY MOUNT ANDCABLE. . . $13 95
QUARTER WAVE WHIP
(specify connector) $ 5.95
RUBBER DUCKY to match
[specify connector) $ 7 95
Ifr^f
t^PIS
Bo?^ 234
Middlebury CT 06762
(203)_758-9228
CIRCUIT BOARDS
REPEATER CONTROL
COMPUTER PROJECTS
SENSITIZED BLANKS
NEGATIVES/POSITIVES
PROTOTYPE BOARDS
PARTS KiT
CUSTOM ETCH/DRILL
RCA 1002 MP BOARDS
CIRCUIT BOARD DESIGN
PROGRAMMING PADS
ART MASTER PREPARATIONS
We can supply many oi the ll«mft you nei«d
10 mak« a p-o bflftrd. Senct SASE + 25 csr^i*
tor catalog.
QC Stafford
t^-SSO
Electronic Service and Development
427 S. Benbow Rd*
Greensboro, NC 27401
919-274-9917 DAY/NITE
Serving Amflteurs Around the World
Send-Receive RTTY&CW
'i'':.i'4
M65K
$69.95
KIT
$99.95
WIRED
ALitom^tic iend &. receive: RTTY and CW
I Complete hardy^are and software ptick<ige
Connects to yout PLT User Port *ind the key/head-
phone \Acks of your rtg
Ten message memortes—ZSS char, each
I Keyboard buffeT^aHow^ typing ahead
'Uses L>ulk-ln PLL Or external TU
Morse tratriier — random S letter wordii
I Includes hard^ft^are, cassette fi^ manual
'TRS-80 version available
Write or call for detadled brochure
Calif tjrni& r^SidenlS iCl<3 e% t^X
(nwfti^ ij™op
Microtronics
V/SA
r.O* Box 74T(S) • Kcy«, CA 95328
(209)634'8S88 • 667-2888
Write for CATALOG
CRAMMED WrTH GOV'T SURPLUS
ELECTRONIC GEAR send sm for handling
• ARCS TRANSMITTER— wilb all tubes & crystal,
brand n^w in original carIon.^v^i«r<^, ...... $12.95
• SCR-522 TRANSMITTERmECEIVER— 100-15* mc,
crystal controlled on 4 chanrte^s, in excellenf condi-
tion iivith ^E( tubes f18} S2©.50
• LM FREQUEI^CY METER— Ireqweticy range 125 20,
OOQKC, operates on 12 or 24 V dc with tubes, crystal
St original calibration book, ex, cond,, checked
oyl. , S54.5D
AC POWER SUPPLY lor above (original) S22.50
• HEAOSET, 2000 Onms with 7' cord & PL 55 ptug,
new , , . $3.95
HEADSET, low im{>edanc9 with chamois cushions,
4' cord & plug eK, cond , . . , , . , , i . v ^ . . $2.95
RUGGED HEAVY DUTY CARBON HANDMIKE with
cord & plug, new S1,SS
• All types of transmitiing^ receiving & special pur-
pose tubes available. We invito your inquiries.
Terms: F.Q.B. NYC, 25% deposit wtlh order, balance
COD or remittance in full. Subjecl lo prior sale and
[^^^ce change.
G&G RADIO ELECTRONICS ,,„
COMPANY 45-47 Warren St. {2fid floor)
Ph. 212-267 4605 New Yorh. N.¥, 10007
Electronics
GXRXI
Furt ASCII Professional
Keyboard K\U Model 756
• full 128 Character ASCfl • TM-ModeMOS En^
coding • MOS/DTiyTTL Compatible Output •
Two-Key Rollover • Level and Pul&e Strobe •
Shift and Aipha Lock • Seiectiible Parity •
Positive or Negative Logic ♦ AN New, OEM
Grade Cqmponems • Gold Corttact^ Low
Bounce Key Switches • Rugged G- 1 0 frinted
Circuit 3oarcl • Low Power Consumption , , ,
and More
Model 756 Keyboard Kit S64.95
Model 701 Plastic Enclosure SM.55
Model 702 Steel Enclosure . .%19.^5
S«nd lor cjitalogue at other NEW merchendlse.
SemiSt Sockets, ICs, Res., Caps, Anil MORE
N.Y.S. Residents Add 4% Sales Tax
Send to; Key ilectronlcs
P.O. Box 350a
Schenectady, NY 12303
i^Kl4
f/^ Header Servfce — see page 323.
281
MFJ INTRODUCES A NEW
24 HOUR DIGITAL CLOCK
with HUBE 1-5/8 inch digits that you can i(eep set to GMT.
Alarm and snooze functions let you use it as an ID Timer.
Assembled, too!
MFJ Enterprises brings you a new 2A hour
diglta! alarm clock with HUGE 1-5^8 Inch orange
7 segment digits that you can mb clear across
ttie room.
Ttiis one \% strictly for your ham shack, one
ttiai you can ^eave set to GMT. No more menial
calculations to gel GMT,
Use till! aJanrt to remind you ol a SKED or
witti the snooze function as an ID timer to buzz
you in 8 minute mtervals.
A constantly changhig t^aleidoscopic pattern
indicates continuous operation.
Beige, 2 1M x 4-1/8 x 8 3/4 mcties. UL lisfed.
1 20VAC, 60Hz.
Order from MFJ and try rt - no obHgation. tf
111 del^ohied, return it wittiin 30 days for a re-
lund {less shipping). One year limited warranty
by MFJ Enterprises.
To order, simply call us toll tr^ 800'G47-1800
and charge it on your VISA or Master Charge
Of mall us a cfieck or money order for S29.95
plus $2.00 tor stiipping and handNng.
Don't wait any longer to enfoy the convenience
oJ a "Hafns Only" clock Order today,
MFJ ENTERPRISES, MC.
P. O. BOX 494 ^mz
MISSISSIPPI STATE, MS 39762
CALL TOLL FREE 800-647-1800
Ftr technical Intonnitlan, anf«r/rapilr ttitus, in
Mn.. oaUidc contlnentiJ USA, ctf Ml -323-5869,
.^022
G.I.S.M.O.
2305 CHERRY ROAD
ROCK HILL, S.C. 29730
Featuring
ICOM
cushcroft
BiiUlBUKDK
^
Wilson
TEMFO
rsen
and now
smMs
too!
DRAKE
\m
IN ADDITION TO THE PRODUCTS LISTED ABOVE, WE ARE ALSO FACTORY AUTHOR-
IZED DEALERS OR DISTRIBUTORS FOR B 8c W, BERK-TEK CABLES, BENCHER
PADDLES, THE NEW AEA AUTO-DIALER AND MANY OTHER ACCESSORIES. OUR
SERVICE SHOP, WITH TWO FULL-TIME FIRST PHONE TECHNICIANS, OFFERS EXPERT
REPAIR ON ALL MAKES, AND FACTORY AUTHORIZED WARRANTY SERVICE
OH SWAN AND YAESU PRODUCTS, QMWyPP T€MLL FR.EE *
THE
GI5MO
GANG IN SX. DIAL 803/366-7157
73,
800-845-6I83
The ONLY thing you
need to know about
Quartz Crystals
Is: i-405-224>6780
Best delivery plus Emergency Ser-
vice w(th Guaranteed Delivery
Highest Quality with gold MIL-
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Ask for Sentry Ted^riQlogy IVlanyal
And, order Toll Free 1'800'654-S650
SENTRY
*^^ Crystal Park
ChieikasKaf Okiahorna
73018
mr^^AiN
MOSLET
* 1 «>5 oo
'. 1 1 FB I n « f*" w s-T Beam
CtiSHCJIAFT
A^ 1 4 1 it 17 rl Z M Brdm
lew
IT tfi
HAfnlll
TIM f*tlf*%.^vrF
At|i.tftri>Hn> ?i
WILSON
ltir 00
2 1 J 00
SAXToii WIRE & CABLE
11*7 00
s^jn H\inf
COMMUNICATIONS
^ce9 SERVICES
3^*^A WEST MAIN rTREEt
PHILADELFKI A MB »»«
FHOKEe Ml-4l4^fMt
HOUIiSt mt HvnWrk.
iMid Btflmp tor pricfl list or %t chsch tor full Ihn* caitAlog.
il raluiKtobl* on rtir«t orilwr. Wit minp only ta 50 stPt^s.
All BlilfifMitn m FOB,
282
P^ R^sa&t Serv/ce— seepage^ 323.
NEW ELECTRONIC PARTS
Brand nam«. firsl lin« components. Slocked in
depth. 24 hour delivery. Low prices afld mofiiiey
back guarantee on alt products we carry.
STAMP BRINGS CATALOG
SPECIALS
KEYBOARD ENCLOSURES
t,K SI7F^ von PRICE
T7" i.i" r- ta.js
Blue base, specify wh^tc or bl^ck lop.
ONLY
SS.7§
• Fj
*L:
RTTY
tJT4 SPieOCVTR BOARD
KIT S109 95
BOARD ALONE S18 95
AUTO CW ID KIT S37,90
SHIPPING
INCLUDED
IN PRICE
Daytapro Electronics. Inc.
Formerly Nu Data Electronics — *^ D3S- —
3039 N. WILSHmE LN ARLINGTON HTS. Ili.«0004
PHONE 312-870 0555
^
— NCM
DIGITAL READOUT FOR
YOURYAESUFT-221/221R
YC-221 Digital Display. Only
$69,50 plus shipping. Kit fof
older FT-221S S3. 00 plus ship-
ping, Duilt by Yaesu.
"i ttiijnntm rr%itt*mtt. tftitf H*"^ mtif* tnr tn i/iP«r urrW.
Send your check or
Money Order tO:
n R. IcE TOWEft
INTPRNATIOMALa
13401 South Hoover Street
Gordeno, CA 90247
^
RTTY
made
Tl> 1 7D kit... « 1^.96
of the «1
I^MP
Uvflcd tUf^flQ in^hf ^D* #^B^ ttffWIQ
Curranc »ouktod looo kanv end po**i' mjosHhi
Adjeosstn with ifr^'igld eomiifll a«l nW Miiv nlvr
Siabki audio trnouaftirv iM^
«iiM>firt ■«■ Twwi tttrwi
TTL 1 imnillili liD^tii «iii| Quiautt fw
Flmir coip.
P.O. ftox 976
TopAko, KaniOft 66601
(913) 234-OlSft *^FS
VfSA
— » 1
How You
Can Convert
Your Rohn
25G Tower to a
FOLD -OVER
CHANGE, ADJUST OR JUST
PUIN WORK ON YOUR
ANTENNA ANO NEVER LEAVE
THE GROUND.
If you have a Rohn 25G
Tower, you can convert it to
a Fold-over by simply using
a conversfon kit. Or, buy an
inexpensive standard Rohn
25G tower now and convert
to a Fold-over later.
Rohn Fold-overs allow you to
work completely on the
ground when installing or
servicing antennas or rotors.
This eliminates the fear of
climbing and working at
heights. Use the tower that
reduces the need to climb.
When you need to ^^get at"
your antenna , , , just turn
the handle and there it is*
Rohn Fold-overs offer un-
beatable utility.
Yes! You can convert to a
Fold-over. Check with your
distributor for a kit now and
keep your feet on the ground.
47" ROHN YOU GET THE BEST
Do not attdfnpt to raise antonna or
antenna support near power (ifies —
You can be KILLED.
Unarco-ltohn
FO Box 2000. Peoria. niinoaetGOl
^m
$^ Reader Service —see pag€ 323.
283
1978 Index
ANTENNAS
Tune Your Tower To 80/160. K9S0G
The Extreme Basics of
Antennas , . , . . . K4SE/WA4DBG
The $5 Magnetic Mount WA2UMV
Keeping the Zap Out of the Shack , W7RG
Can A M miature Antenna Work? W6AQM
The Powerful Grounded Antenna W0SII
Meet the Plastic Wonder K0OXB/5
A 2m Antenna for the Perfectionist. WB2AWG
A Brass Horn ForX-Band.. W1SNN
Extended Double Zepp W6TYH
New Dipole Feeder AA6AX
The Cliff-Dweller's Detight WA2UVC
Wait Til! You Try 16 Elements! WA8FCA
Working 15m With A 20m Beam W8ZCQ
A Better Feedthrough For Cables, WA8FCA
Resurrecting The Beverage Antenna , W5USM
How To Hang A Longwire W5GN
The '^German" Quad WD4CPK/DF3TJ
Mobile In Disguise. K9MLD
Better Than A Quad . , WA4NWW
The Perverted Double Vee Antenna VV5VSR
Towering Low Band Antennas K3QQF
The 80 Meter Pile Crusher W20ZH
Phased Verticals For Easy DX W1ZY/LA(DBP
The Miserly Magnetic Antenna . , . . W2AZD
The 75m DX Chaser Antenna ...,,.,.... N4VD
The Invisible Allband Antenna. . ..... WA4FYZ
Who Says Verticals Donl Work?, W2LFJ
New Use For CB Antennas. WA2KBZ/JY9KS
Confessions Of A Vertical Fanatic. .,,... KH6HDM
The 21 -Element Brown Bomber W9GGI
The Two Hour, Two Meter Beam, WB9TNW
The OSCAR Boppers G3ZCZ/W3
The S-Meter Bender . , W8HXR
Amazingly Simple Log Periodic Antenna. . . K1QAR
Disguised Birdhouse Vertical K5LUW
Enjoy All Five Bands. ......_ W8FX/4
Novice Guide To Phased Antennas. .,...,. W8HXR
The PVC Portable WA6RJK
The Swiss Fork Special , Staff
The Sneaky J \ W8FX/4
High Q Antennas. K4KI
The Ten Meter AM Antenna Special W6RCL
Antenna Design: Something
New! W4FD, W4ATE
The Schizophrenic Triangle. ,...,..,,,... WA4JTJ
CALCULATORS
Negative Numbers On A $9 Calculator. . . WB6IXT/7
The Experimenter's Dream Calculator Reid
CB
The Ham CBer. .... . . , WA4BaU
CB to 10— part VIM: the Publicom I WB6LQE
From CB To Amateur Radio. WB4P0H
How About SSa CB Conversions?, W4GBB
What? CB Repeaters?! , WA4E0X
CB to 10— part IX: a pair of Radio Shack
CB to 10— part X: Reaiisttc's Mini
23 K5LUW/K5SA
CB to 10— part XI: Hy-Gain's PLL rigs. . . . WB58SG
CBto 10— part XII: convert aKraco PLL rig, , .W1PI
CB to 10— part XIII: the Lafayette
Telsat DF1SP/W2
CB to 10— part XIV: a Realistic PLL K0QLC
CS to 10— part XV: a Realistic HT K5UKH
CLOCKS
The "Do ft All" Digital Clock- , K6UGT
COMMERCIAL GEAR
Reprogram Your IC-22S. , W6UTE
Simple Scanner For the 10-223 KH6EM
Improve the AX-190 Receiver WA3TLD
I Love My GTX-1 WA4H VH
Heath HT Goodies. WA1 IZS
Drake TR-4CW Review , K4TWJ
The Tempo 2020, WA2K0K
118
Jan
116
Feb
118
Feb
130
Feb
160
Feb
26
Mar
58
Mar
154
Mar
164
Mar
34
Jun
38
Jun
40
Jun
42
Jun
46
Jun
50
Jun
52
Jun
58
Jun
60
Jun
62
Jun
64
Jun
66
Jun
74
Jun
76
Jun
82
Jun
86
Jun
88
Jun
92
Jun
96
Jun
122
Jun
134
Jun
140
Jun
154
Jun
160
Jun
170
Jtin
174
Jun
178
Jun
32
Jul
48
Jul
49
Aug
90
Aug
160
Aug
68
Sep
146
Sep
282
Oct
44
Dec
32
Jan
114
Apr
172
Jan
98
Feb
114
Mar
96
Jul
34
Aug
78
Aug
138
Sep
172
Sep
254
Oct
86
Nov
120
Nov
238
Nov
176 Aug
54
Jan
74
Jan
106
Jan
150
Jan
180
Jan
30
Feb
48
Feb
Put A Sony In Your Shack Staff
Don't Miss the Excitement of QRP K9SGZ
Wireless Monitoring For the Bionic Ham. . . W8FX/4
The Go Pro HT Mod. ,....,,. W8FXM
Good Grief, Not the 22S Again?. . , WB2LEI
Improve Your HW-2021. , K1WXK
The IG-102 Goes Transistor. .. Rossnick
No, Not Another 22S Mod? VE2TM
Cushcraft Does It Again!. .,.,,...... K10PQ
Can A $20 FM Rig Work?, ...... WB4LJM, WA4WDL
Hiss Exterminator * K9P0X
The FM Rebroadcaster. *..,...,.......... W8FX/4
22 Remote. , , W8FX/4
The IC 22S Scanner. W9LI J
A Much Needed Micoder Power Supply K3MPJ
Sometimes A Kit Is Best. W6SWZ
Rock Steady. ,. WA5R0N
Updating the Wilson 1402 WA9RAQ
HW-101 Owners, Check This! HB9SLU
The Toggled 22 Fletcher
The End of Autopatch Embarrassment W4CUG
Another IC-22S Scheme. WA1ZMQ
Improving the SWTPC UDI K3MPJ
When In Doubt, Improvise! W6LTV
The Case of the Missing Off set K3JZD
What Do You Do With ATimekube? Staff
Another Trick f©rthe223 WB7SHW
MicoderTM Magic K4BJF
Mighty Mods for the 820S. ......... K4FK, WA4KIL
Improving Heath's HT WA6TLK
Oddball Splits and the IC-22S W6YUY
Triple Threat K3CMY
Two Meter HT Survey K5XY
Happiness Is A Smart Scanner K8JS
Improved Scanner for the VHF/One Plus. . . W7AAY
Further Adventures of the IC-22S , , . W6WUT
The Multifunction Scan Can W1IBI, W1HZH
Happiness is a DMM Kit W7AAY
Deep Dark Secrets of the TR-7500 WB9SEQ
Heath's GR-88 Gets Rengiont W2AQ0
Wow! A Good Portable Receiver! WA2EJT
The XITEX Video Terminal AH6AQ
Light Up Your Life WA4NUE
The 22S Goes Digital. KH8IEL
CONSTRUCTION
Forget Ohm's Law Stanf ield
Build A Deluxe QRP Transmatch WB4VLQ
Dodge That Hurricane! WB4IXK
New Life For Old Transformers WA7NEV
Cool It' K4KI
Build A Simple Capacitance Meter. , W8DCC
PC Techniques Staff
Inexpensive EKG Encoder. WA3AJR
Build A Better Phone Patch. , Poirier
Build A 3-1/2 Digit DVM. WA5VQK/5
Tune-Up Aids For the Blind — ... WB1FFQ
Measure Periods With Your Counter. , ,
The Overkill Stall Warner..*
Flash Project For Camera Fiends, .....
The Solar-Powered Ham Station. ......
A Cheapskate's Circuit Board
Build This Digital Ball Game- ......
In Search Of the Ultimate
Super Deluxing the TR 33 WA6JFP
Hey, Old'Timers! The Breadboard Is
Back! WA7NEV
The COR Goes Solid State WA6ILQ
Enjoy All Bands With A Remote Tuner. . KL7AE
Counter Accuracy For Perfectionists K&KDT/5
Graduate to a Better Operati ng Desic. WB6EK0
Relief for the Rockbound WB2EQG
The ARC Tuner K9QLL
Buddy, Ya Got A Match? , K4KI
"Stop Timeouts!*' Revisited WB3ELV
Add-A-Scanner N2YK/WB2NyK
The Circuit Board Aquarium WB9QZE
Build a Realistic S-Meter. DJSNW
Build the Flexi-Filter. W3QVZ
The Klassic Kilowatt K4TWJ
Code-Practice Oscillatofs. W6GXN
PCs Are Easy. VE3CGE
, K6MWM
..W9CGI
WA6UNK
..W5VB0
WA1BVD
. ,.N2RG
. . W6YUY
CONTROL
Simple Sequential Decoder
The World Of Tone Control.
W7JSW
. K3JE/2
102
62
134
152
172
130
120
158
166
52
54
72
80
86
90
150
60
114
126
148
168
44
46
72
118
122
164
214
48
54
64
130
142
250
262
274
192
208
212
222
130
132
136
206
46
61
62
70
78
164
168
20
28
40
64
92
150
140
146
168
36
66
72
46
162
118
76
48
74
128
152
168
116
240
126
222
226
256
270
166
82
Feb
Mar
Mar
Mar
Mar
Mar
May
May
Jun
Jul
Jul
Jul
Jul
Jul
Jul
Jul
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Aug
Aug
Aug
Aug
Sep
Sep
Sep
Sep
Sep
Sep
Sep
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Oct
Nov
Nov
Nov
Nov
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Dec
Dec
Dec
Jan
Jan
Jan
Jan
Jan
Jan
Jan
Feb
Feb
Feb
Feb
Feb
Feb
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Mar
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Apr
May
May
Jun
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Sep
Sep
Sep
Sep
Nov
Nov
Dec
Dec
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Dec
Dec
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Mar
284
Fake 'Em Out With Remote Control W4VG2
The Miser's Delight Repeated Controller. , . W2PMX
Give 'Em A Break .... WB6JPI
Should Repeaters Use Subaudibfe Tones?. . . . K9XI
Power Line DX ,. , N2CX
Hung Up On Autopatch? V\/A6THG
The Tiny Tone Repeater Saver W4VGZ
The Autodialer Revisited, , .. W7JSW
The Easiest Offset Ever. K4GOK
Automatic Repeater Offsets. ...... N2yKyWB2N VK
The 2Sc TouchtoneTM Mod . W9CGI
SSTV Recorder Controller. , , , K3JML
COUNTERS
VHP On Your Frequency Counter WB0CLH
Good News! Lassagne
CW
Brass Pounding Simpltfled
Simple CW tnterferer^ce "FIfter"
• m i«^ .« . K6JM
W8FX/4
You. Too, Can Go DigitaL . - -
The Best Probe Yet? . . .
A Darn Good IDer
Time and Tide— Digitally. . .
DIGITAL
...... WABJMMmeWA
. . . K50M
.^WAITNG
!§ -« i- -I ^ S tb
I ■■ P ■■ «■
» » « « 4
ri 4 'i p «-
..W1HCI
. W7RXV
..K3Je2
WA4GIM
..W6NUI
..WlOiS
GADGETS
The Trailer Light Solution.
Custom-Made Thermistors, . . ....
^hJ'U LrfT t^ I ^J I I ^^ II- - r * t, M M ,M m> * « * !!■»■■ -P 9 * * ^ M: * m « ■'
New Protect ron For Your Car. ....
Kerchunk Counter ...,,,..,,
Shock the Car*Burglar. , , , . .
The Super Setect-o-Ject. , , W8FX/4
De-Zap Strap W6SWZ
The New, Improved Automatic Thermo-
stat W9YBU
It's Flora Clocki , W8FXy4
Computerized Capacity Meier. Eccleston
The Universal Notcher W9CGI
Beat the Microphone Biahs. K1 HQW/4
Roy Rogers Special: Triggered Sweep. ..*.., Reoaud
Watch the Wind*. ....... WA4FWH/5
The Op Amp Beam Heading fndrcator. K0BV
Watergate Special , . . . , HB98tU
Be Mr. Clean! WB4FXD
Maintain Control!. .....**....... ..... Stanfield
Active Voltage Divider PY1AQUCT1EM
Light Right? Mills
Build A Better Beeper, W3QVX
HISTORY
11 ow n was, ..1 ,-.---,... w ■, % -r * t -^ ^ ^ , ^ ^
The H istory of Ham Radfo— part VI
The History of Ham Radio— part VH
W6LM
.W9CI
.W9CI
HUMOR
I Need A Contact , WB2DYU/2
Murphy's Masterpiece WA6PPZ
IC
W7BBX/4
........,.W3HB
K4IPV
WA2SUT/NNN(5ZVB
1 69I I rl05c ivSi. ...V........
IC Timer Review , ...
The Op Amp Encyclopedia. . .
How Do You Use ICs?— part
IX, ,,__ ._ , .
Is TTL Already Obsolete? , .... WB5IRY
Schottky: A New IC Generation McClellan
The New Op Amps WAOUVX
How Do You Use ICs?— part
X, , .,, . WA2SUT/NNN€2VB
Build the IC Experimenter, . . - . Leonard
The Long-Term Effects of Working with
ICS . . - , . . WA2SUT/N N NOZVB
Bargain Preamp. W5REZ
555 Basics—And More! WB4CE0
I/O
To Err Is Human. — .
Practical Computer Projects . . . .
You'll Like SOL! * .
How To Keep Your Computer Happy.
The Bionic Clock!. ,...,*... . , .
. . . WB2T0C
, , Mickle
,...WB6JYK
. . . WD9DDV
W4CQI
52
124
62
102
52
112
132
32
34
74
82
56
82
32
134
142
156
50
50
96
76
143
185
116
156
60
64
S8
S8
134
156
118
36
142
170
174
204
122
86
92
94
98
102
May
May
Jul
Jul
Aug
Aug
Aug
Sep
Sep
Nov
Nov
Dec
Dec
34 Oct
44 Oct
58 Feb
132 Apr
Mar
Apr
Jul
Aug
Feb
Feb
Feb
Mar
Mar
Mar
May
May
Jul
Jul
Jul
Jul
Jut
Jul
Jul
Aug
Sep
Sep
Sep
Sep
Sep
Oct
152 Jan
68 Oct
90 Nov
138 Mar
48 Nov
24 Jan
40 Jan
166 Feb
Apr
Apr
Apr
Ju
44
120
158
78
94 Sep
220 Sep
182 Oct
44 Nov
60 Nov
Jan
Jan
Jan
Jan
Jan
. K4HBG
. . K7SBK
WA5JSF
. . W4KFT
, W6GXN
, . Lasher
, . Stewart
Eaton
w d n *
KIM-1 Can Do ItL W4CQI
A Secret Weapon For Road Rallies. , , . K9PTI
Looking For A Micro?. O'Reilly
Fiendish New QUBIC Program. ... .... Bishop
Put An ELF In Your Keyer. , WB9MQY
Try HCAI. Hughot
Solve Those Parallel Problems N3IE
At Last! An RFIfree Computer.... .... WB6JYK
Another Approach To the ASCII/Baudot
Programming CoM Design
Outstandmg Computer Bargain
Do Biorhythms Really Work?
Feeding A Hungry Microcomputer. ......
The Exterminator .,,....,.,.,
At Lastl A Use For Your Computer!. .
Now Anyone Can Afford A Keyboard. . ..
Godboul Strikes Again. WA7NEV
The Kllngons Are Comingl. WB9LSS
Diary Of A Survivor , , — WA6PPZ
How Good Is the North Star Disk?. ...,,,..,. Bosen
Pseudorandomness Is Just Not Good
Enough. WA1 PTZ
Beethoven Need Not Fear. G8HBR
Hex Converter For True-Blue Octalists Pol i near
The Cheaper Beeper VE2SVW
Semi-Instant Program Loading WB4GXE
Low-Cost Keyboard- II Eaton
Computerized Loop Antenna Design, ..... WB2IPD
He'^l Wail For Me! .., **.. WA3MWM
Morrow's Marvelous Monitor. .*...... Eigsti
RAMmed by Morrow. Hallen
Six Said His First Words Today!. ....... WA3MWM
The 22s Programmer Program. . , , W60VP, K6MAR
The Occult Computer. ,....*,, .,..., WA6VIY
A Baudot Program For Your Micro Fricke
The Kalcufating Kl M-1 Lasher
A No-Cost Digital Clock N8RK
The BASICS of L-Network Design K7SBK
Nuclear Attack!. . , WA7WKA
Computerized QSO Records WA7VZR
RAM Checkout's A Snap ......... WA7NEV
Interrupts Made Easy. WB6L0A
Use A Computer? Who, Me?. , . . , WB2H JD
Bird Watching in BASIC Land . K6EW
Computers and the Real World , , . . W1 FZA
World's Cheapest QSLs. . . , WA7VZR
"Look What Followed Me Home!** LIlie
A Hex on Your 6223. Schneider
p V » 1
The Micro Maestro!..
SSTV Meets SWTPC: Part 1 ....
Whither Microcomputers?. ....
SSTV Meets SWTPC: Part 2
A Multt-Memory Morse Machine, . . ,
*'This is Your Computer Speaking" .... Sorrels
RTTY with the KIM. .................. VE1 AKL
DX Delight , . . . WA4VQD, N3NN
. . . . K6EW
...K6AEP
,WB2HJD
...K6AEP
. WA8TIW
KEYERS
Try A Sensor Keyer. , ...,,.,*.
The New, Improved "Best Keyer Yet'\
Novices, Paddle Your Way To
Happiness. ...... .
A Keyer? Who Needs Another Keyer?.
The $5 Memory Keyer. - . - ...,.,,
The Heavyweight,
Sidetonels AMust. ..... — ....,..,.
Custom-Make Your Key Paddle. .... *
Build the Triple Threat Keyer. .
.WB4TED
K4JEM
ri I i -i
■w * ■* *
..W0OGX
. . . W6APZ
. WA2EBY
....K9MX
..VE3EKR
....W6JB
,.W8FX;4
MISC
The Unbeatable Base-Loaded Three-Element
Rotary Vertical. .**. ♦ - . . W3KBM
Hooking the Kids * Di Blast
Home Brew An Elephant! WB6iQS
Grow A Giant Junk Box!. .,.•,, WB7CTH
Is It Glass . , . Or Iron? .... WA2SUT/NNNiBZVB
Raid! * .,.- W8JJO
See Q, See Q ..........,,.,,. VE3FLE
Coming of Age. — VE3FLE
How To Compete With An HT VE7AQS
S.A.S.E. W9CGI
A Ham's Life Cycle VU2JS
How To Dissipate 200.000 Megawatts W4NKV
The Great Cover-Up. . , W4FXE
68
72
76
78
82
84
88
92
96
98
104
110
76
84
88
92
102
104
92
100
103
106
110
111
112
100
108
111
114
110
112
114
116
118
too
106
10s
100
106
112
146
154
156
161
166
142
148
150
168
148
152
160
164
170
174
44
24
100
74
128
15D
144
22
114
146
158
160
88
90
100
110
112
114
153
78
Feb
Feb
Feb
Feb
Feb
Feb
Mar
Mar
Mar
Mar
Mar
Mar
Apr
Apr
Apr
Apr
Apr
Apr
May
May
May
May
May
May
May
Jun
Jun
Jun
Jun
Jul
Jul
Jul
Jul
Jul
Aug
Aug
Aug
Sep
Sep
Sep
Oct
Oct
Oct
Oct
Oct
Nov
Nov
Nov
Nov
Dec
Dec
Dec
Dec
Dec
Dec
184 Jan
22 Mar
Mar
May
Jul
Aug
Aug
Aug
Sep
Jan
Jan
Jan
Jan
Jan
Feb
Feb
Feb
Feb
Feb
Feb
Feb
Mar
285
Are You Afraid To Build? ,,,,,,,
Can A Diode Replace A Relay?, .
If You Want To Know Where You Are.
CWthe Hard Way ,
Why Not Go First Class''.
, W4RY0
, * + . oi a ii
Burhans
. . Pel ton
W9C6I
Another Ten Minute Timer?. . . N9MX, K9MX
[f You Want To Know Where You Are, , _ , . Burhans
Scare the Hell Out Of Burglars. WA6WUt
Happiness ts Being A Ham
Manufacturer W2NSD/1
Creeping Crud Got Your Signal?p . , K4TWJ
Modernize The Matchbox, ,,..,,...,., W8FX/4
The Towertess "Tower*" K4FK, N40G
Finding Radio Pests.,..,. WA1UUK
Video Magic For Your Home, , ,,4. -,.-•-,.. K4TWJ
Instant Engraving , . W7RXV
J. B* Fields. Radioman WB7SZC
Handling Ole George K5GNZ
Forbidden Contacts. ...,.,.. -^.. •.-..* Nobel
Instant Paddle W3IH A
The War Against Rust. K8AO
Radio Row Revtsited. W8JJ0
Shockl!. ...., McAlrstef
Sleight of Hand. ..............._. K4SE
2001 - 3. * .... - ,♦..♦..,*,.......,... WA5SNZ
Dispense I! Right! W4RY0
Ham Radio Is NOT A Rich Man's
Hohhv WAfiNnx/1
Poor Man's Cruise Controi. - W9CGI
Be Legal. „ AD4A/W A4M FY
The SWL Bible. W2XQ
Relax and Unv^md , . WA4TJ J
Home- Brew Circuit Boards W9IWI
Kerchunk , . . Kaboomt . . ...,.,.. N5KR
The KM1CC Story. WAI JWD
Reusing Coax Connectors W0FEV
,WA7NEV
WN3NNY
..VE3FLE
Building From Magazine Articles
Hello Hamdoml
More "'Coming Of Age"
High Seas Adventure— Ham Style-
part L . . , WA6FEI
DMM Buyer's Guide ...*♦,. » McCfeilan
The Ultimate T-Hunt WB6JPI
It's A Ham's World. ....................... K2HTO
Tuned Circuits In Your Junk Box W3KBM
Electro Sculpture* VP2DN
Sifence Groaning Refrigerators* K4K1
How About Some Ham Shack Safety? W7FGD
Who Uses All Those
Frequencies? WS6JPI, WB6HDB
« ! I V 4
I i 4 ft -i ^ #
, Edwards
WA4DQN
, .WB5ILK
, _ WA6FEf
.WA1PDY
,,.W20LU
, , , . , K4S E
N4AL
...KSNQN
....K4IPV
MDS: What Is It?. ....
The Junk Box Station.
R-X Bridge + Calculator = Vswr. ...
High Seas Adventure— Ham Style—
Squelch Ifying Cheap Receivers
Vintage Receiver Mods. ............
Using Bar gain Muff m Fans
Ham HelpL*
Close Encounters. ..,-.i. ......
Receiver Diseases
Htgh Seas Adventure— Ham Style-
part m, WA6FEI
The Packet Radio Revolution VE2PY
WARC 79 Preview, WA9MZS
Ham Radio Goes to School. N2CF
The Games People Play , WB3EUG
An Improved HV Tube Socket Miller
MOBJLePORTABLE
Hands-free Mobiie Mike. ........_ W9KXJ
The Double Whammy Mobile Glarifier K8JS
The Amazing Mobile Lite Preserver W2EVM
The Mobile Dream Machine. .,. ..... K9SQG/8
Mobile Security Blanket, .... .... WA1RTD
OPERATING
Guilty? Or Not Guilty?
Where, Oh Where — . , . . ,
Shoestring Switching For CW. , .....
Relaying For Fun And No Profit .......
Repeater Procedure
How To Work Europe With An HT. ......
Ruddy Good Show* ...........
The End of the Rat*s Nest. ..,-...
Four-Wheel Frenzy!. ......
. . WA6HDK
W2XQ
...Baldwin
..... N2RG
..WB4NAY
N2MW
. . WB9PYM
.... G3WDt
..WB9FRM
.....K6WS
156
184
106
178
84
128
146
160
30
72
84
146
42
44
58
74
84
136
170
176
26
44
76
94
141
142
184
40
50
98
132
140
38
72
74
102
103
112
126
136
210
256
32
42
52
104
106
126
130
136
182
210
276
286
36
90
142
192
212
230
274
287
69
138
32
34
52
54
2n
58
92
26
Mar
Mar
Mar
Apr
May
May
May
May
Jun
Jun
Jun
Jun
Jul
Jul
Jul
Jul
Jul
Jul
Jut
Jul
Aug
Aug
Aug
Aug
Aug
Aug
Aug
Sep
Sep
Sep
Sep
Sep
Oct
Oct
Oct
Oct
Oct
Oct
Got
Oct
Oct
Oct
Nov
Nov
Nov
Nov
Nov
Nov
Nov
Nov
Nov
Nov
Nov
Nov
Dec
Dec
Dec
Dec
Dec
Dec
Dec
!78 Jan
168 Apr
51 Aug
58 Sep
270 Oct
Jan
Jan
Feb
Feb
Feb
Feb
Aug
Aug
Aug
Sep
Tracking the Wild Turkey .,.._... WA8BHR
Meet Mr. Biiz2ard. . . K8YQH7AA8P
The BIrzzard of 78. W8HXR
Two Meters At the Summit, , W6FJT
DXpeditioning WA2VMS
The Lady Saw Red WB4ZVZ
Tweaking Your Linear , . . , W5VSR
Support Your Local Fire Chief W1 FYR
Try FM On 29,6 MHz. ...*..... , WA7WYF
Automatic Autopatch W6GJS
A DXer's Dream Vacation WB6JPZ
POWER SUPPLIES
Power Suppfy Regulation . ..,...,,, WA3TLD
How To Cut Costs On Power Suppfies. .... W9HDA
Surprisingly Low-Cost Latj Supply W6GXN
Avoid An Overvoltage Catastrophe, W7RXV
Coming In Out Of the Cold. W6GXN
In the Eye of the Beholder WB6JYK
Super Charger WA7YGB
Don t Let Your Battery Die WB8TXG
Power Supply Magic. Burt
Charge! W4VGZ
The Frugal Aiternative. ....... . . . W8FX/4
A Perfect Power Supply?. , WB3BUU/8/KSUR
Build the Brute , , . . , . N9KV
Four Terminals Are Better Than Three. . _ . W1SNN
roll' OCi 1^.*....... , .m-m-r *....*.*.. ...... ...^ W r\ f %J f f\
RECEIVERS
0(d Receivers— A Hidden Gold Mine W6GXN
Build This Excitingly Simple Receiver. K4DHC
Build Your Own Digital Dial. W1 OOP
RTTY
On Your Mark! WA4KIL, K4FK
The UART Gear Shifter KB8CE
Novel RTTY Autostart. K20AW
No More Excuses!. WB4MBL
Build the "Version Three' Colby
Blockbuster RTTY ArtJcleL W9IF
SATELLITE— OTHER THAN OSCAR
Weather Satellite Pix Printer. ............... W3KH
Toward A More Perfect Weather
Picture Cawthon
Attention, Weather Watchers*. .......... Cawihon
Be A Weather Genius. WS8DQT
Autoplnasing for WEFAX Cawthon
SSTV
What Are They Showing On SSTV?. .... .... K4TWJ
What Happened To SSTV? . ^ . .... K4TWJ
SURPLUS
Space Age Junque III . . .... W9CGI
Surplus Adventures. W9HDA
Be A Surplus Survivor, WB4APC
Another Surplus Treasure. , , . , , McClellan
Space Age Surplus Endress, Endress
TEST GEAR
Brew Up A Signai Generator. Staff
Clean Up Your Act. Staff
Build This FM Signal Generator W9HDA
Pulses Galore!, # . , . . .4 . . . Plavcan
Versatrie Transistor Tester, .............. WA5TFK
The Quicker. Slicker Transistor Checker Sergo
How Many pF is That Capacitor,
Real I v'^
How Much Power Does It Draw? . , , .
The Amazing Zener Sweeper.
Ecstasy in Multimeter land. ...
Use Noise To Tune Your Station
Now— A Digital Capacity MelerE
Make Antenna Tuning A Joy.
Home-Canned Dummy WB2BWJ, WA2JZR
Reincarnating Old Test Equipment W3KBM
Your 'Scope Can Be Improved. N5KR
Pick A Frequency . . . Any Frequency. , W8FX/4
In Search Of Stability. ...... . ... Burhans
Build A TTY Tester , . . . , ,, , ,
Interchangeable Test Leads,
Build An Audible Transistor
Tester. .,,...„-,.. WB7N2G/DA1DB
WA0ZCR
. . Fowler
WB4YOD
.WA4AIH
. W600B
.W3KBM
. . . K5QY
64
BB
92
224
26
184
252
258
184
266
30
Sep
Sep
Sep
Sep
Oct
Oct
Oct
Oct
Nov
Nov
Dec
140
Jan
28
Mar
132
Mar
176
Mar
154
Jul
64
Aug
120
Aug
151
Aug
78
Sep
201
Sep
186
Oct
268
Oct
186
Nov
7?5
Nov
250
Dec
36
Mar
76
May
66
Jul
82
Aug
38
Nov
68
Nov
124
Nov
216
Nov
218
Nov
254
Nov
82 Jan
. K7YZZ
,K3MPJ
116
218
196
96
24
72
170
126
62
96
60
50
136
154
194
122
31
48
131
178
24
160
58
134
154
40
92
146
80
198
249
Apr
Oct
Nov
Dec
Feb
May
Jan
Feb
Sep
Nov
Dec
Jan
Jan
Jan
Jan
Feb
Mar
Mar
Mar
Mar
Apr
Apr
May
May
May
Jul
Jul
Jul
Aug
Oct
Oct
291 Oct
236
The Chip Switch.
Build An FM Tweaker
FM Calibration or> a Budget. . . . . .
Build the S80 Wonder. ..........
Build A Decent Dummy
A JunK Box Load Srmulator. ...,.,
An Eicpenmenter's Delight.
The Lunch Counter .,.*,...
This Voltage Standard Is Precise!
What's Your uF?,„„ .,,
WB2QEL
,.WA6THG/KH6JSA
W3HB
K4tPV
. W5J J
.WA1WLW
_WA4PIN
. . WB6NTR
..,.K5BTV
« m * ■* * m '9 ■
THEORY
Think You Understand SSB? , . . W2FEZ
Try The ID VIP Method Hargett
Op Amp Insights, ,,.,,,, . K41PV
Transistor Primer. K1UZ
Ham Shack Anthropometrics W3ZVT
Logical Logic, ........,.,,.,„... h*6WA/WAejMM
How To Use A Varactor W6JB
New Life For Your Old Dipper W2CHO/K4EA
How Sunspots Work WA4FDE
Danger! Microwave Radiatron WB6JPt
Official FCC RFI Report FCC
DMM Survival Course McClellan
Novice Guide To Phased Antennas .... W8HXR
The End of Rf Feedback K4TWJ
A WWV Primer W8FX/4
New Life For Double Sideband K1I0
More CW Fun With Break-In Keying. WBC&KTH
DVM Scrapbook. McClellan
Gourmet Guide To Capacitors W5J J
Reveals BiasL .,..,... , , , . W5JJ
Microstrip .._.__ N6TX
Low-Pass Filter Primer .,_. K20AW
PLL Techniques Earnshaw
The SUMSUE Method. KiRH
Head "Em Off ai the (High) Pass WB6GNM
Educate Yourself. WBt AHL
One Meier— Many Jobs. . _ Fletcher
Who Needs Transistors?. WSJ J
Loran-C as a Frequency Standard, WA4EID
Ffom CW to Computers , N6RY
78
100
108
112
244
252
28a
105
200
234
34
58
142
149
174
188
182
40
136
170
30
62
136
72
84
152
180
82
126
136
80
98
188
36
56
64
102
250
278
48
Nov
Nov
Nov
Nov
Nov
Nov
Nov
Dec
Dec
Dec
Jan
Jan
Jan
Jan
Jan
Jan
Mar
Apr
Apr
Apr
May
May
Jun
Aug
Aug
Aug
Aug
Sep
Sep
Sep
Oct
Oct
Oct
Nov
Nov
Nov
Nov
Nov
Nov
Dec
Tuned Feeders and Other Good Stuff. ...... W0VM
Big Max Attacks. . . W2DU
The 'TJim-Flam" Factor WA2SUT/NNN02VB
118 Dec
182 Dec
216 Dec
TOUCHTQNE
Clean Up Your TouchtoneTi^ Act
Autopatch Digit Suppressor. * . . . . . .
Painless TouchtoneTM Adjustment
Is Your Repeater Up-To-Date? , . . .
A ^ n e a per wnip, . ^ .•«*■<...>■.*.. i,*...
How To Thwart Ma's Dial System. ......
Quick Check For TT Pads.
Total Control ,
Super Simple TT Generator. . . ,
. WA6THG
. . . K4FFW
. . . . W3HT
. . . W4VGZ
. . W7JSW
Ring
. . . K3SPP
.WB2MPZ
,WA6AFX
TRANSCEIVERS
Tighten Up Your 56-102. W2PQG
TS'700A Calibrator K9POZ
Exorcising Power Supply Demons K4rPV
Re|uvenate A Pawnee!. ......,..._ K4GRT, W4IEV
TRANSMITTERS
0\6 Rigs Can Live Again! K4IPV
You're Still Using Tubes?
Yeccchl , . . W6HPH/G5AWI
VHP
Try 220, You'll Like It! .... K0OST
VHF Notch Filter WA4WDL, WB4LJM
Yes, You Can Build A Synlhesi^erL .,.*.... K2DVQ
VHF Trans verlers and the FT* 101 W60JF
UHF
UHF Propagation KL7IEP/1. W1KIQ
1220 MHz— Use It Or Lose It?. ........,.,,,. K1CLL
How To Succeed On 1296 W4UCH/2
The Challenge Of 10.5 GHz. ...... W1SNN/WR1 AJE
Can Hams Counter Police Radar?. . . WA4WDL
Novw Try 1296 MHz, WA4WDL, WB4LJM
A Complete X-Band Transmitter W1 SNN
A New Type of 10 GHz Receiver. . . , . Kopeika, 4Z4TJ
An X-Band Transceiver , W1SN N
44
124
146
66
150
164
115
60
78
53
128
52
104
Feb
Feb
Feb
Mar
Mar
Apr
Aug
Oct
Oct
Feb
Feb
Mar
Oct
40
Mar
50
Apr
154
Feb
123
Jul
124
Jul
168
Jul
62
Feb
72
Mar
32
Apr
60
Apr
80
May
158
Jun
38
Aug
222
Sep
64
Dec
An Improved HV Tube Socket
easy modification
Harry J. Milter
991 42nd Si.
Sarasora FL 33580
V
ertical sweep ampli-
fiers may have a high
pulse voltage on the plate
pin of the socket. This may
cause an arc to the adja-
cent cathode or filament
pin.
Socket replacement,
white proper, may take
considerable time.
[ suggest that a slot be
cut with a keyhole saw be-
tween the pins which are
defective. This air gap be-
tween the defective pins
now provides better insula-
tion than the original
socket. ■
SHORT ACROSS Pm%
SAW SLOT
BEFORE
fig. 7.
AFTER
287
type
7H2n2 tiP%
7nnz2 sen
■hUSw
LITY and SERVICE
»
SCR
TRANSlSTOitS. Ef C.
C«» VCE IC PO Ft H£Pf
rD92 4tlV .lA ^3U MHIU /£4
n^Oi *9 1.% )pO ISO S3931
* m 1.D a.o so
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SAME DAY SHIPMENT
TRANSISTOR
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BOX 41778 4811 MYRTLE
SACRAMENTO. CA 95841
\#^m ^B ^H ELECTRONICS. INC. I ^^T Kh ^b I I 1 ^b ^h
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TENN. RESIDENTS 1-615-764-0831
AUTHORIZED DEALERS FOR
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SOUTHS fASTB^T OROWtNG AMATEUR STORE
1315 BLUFF CITY HWY . BRISTOL. IN Z7^2Q
238
/97Y
jomm/iwm
RESONATES YOUR TOWER
ON 40, 80 AND 160 !
T^
C^l
a Villa bis for 160
meters
Now you can e3$i[y M%e
youi' entire tester ifid
preseni b«iaiti lyt^em « i
compteTe low jn^le
rodutor ofi 40, 00 and 160
m^l^Fv tt H tdnunon
knowtedge that a dipole
or "mvened-vee mui^t be
at leasi 1/2 w«ve len^^h
hi^ (120 feet on 80
m^ier^I^ in order for il \o
be a low angle r^ijiior.
Buf your eusiing tower , H^
ted with th« Smart Elec-
irotik^TOtUfgfUHER,
can be made to be an
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radiator on 40.80 and 160
metefi. The Stuan
TOtUEftTuntAi^^ti bQ
in«t«,lled and easily
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[any towei hq miilter what
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can be grounded or not.
I^dial^ not necessary. No
more haywire appear-
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Even your wife will
lov^e it. The Stuart
TOUIERTUmfi lakes
\
no e%UA
greatly
outpeHorms dipole§ and
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plu$ It IS easfly adjustable
from ground level, ^tiirt
making! better contacri^
an the 40, BO ar^d 160
meter bandf wiiK ian
antennal system thai
really gets put The Stu^ri
TOUJ^TUTIEA wifl
handle 500 warn output.
«»lllEt
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Priced from $129.95
includes ihippmg tncofi-
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ANAHEIM, CA. 92801
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£ mies souHt vt tOl Irom S F AtrpoKt
OVER THE COUNTER (Mon. thru Sat 10 AM to 5:30 PM)
MAIL ORDER, Phone, Write.
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(714) 560-4900
Higtway tKM CtannwM tttaa BJvd
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(213) 988-2212
P^ fleader Service — see page 323
289
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iNSTflUCTlOMS AhfD WANUFACTUflEflS WAHRANTy I UNDERSTAND THAT »f > AW NOT COMPLETELY
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MAIL TO: 6610 LARKWOOD
HOUSTON. TEX 77074
ATTN: STEVE, WA50EN
F^HONE: A.C. (713) 777-2673
m
2 METER
CRYSTALS
MANY
IN STOCK
FOR THESE RADIOS ON
STANDARD ARRL REPEATER
FREQUENCIES
CEegg HT U6
Dr^kf. TH 22
Drak^ TR-33 tree cmly]
Drake TR-72
HeaThhfl HW-2(}21
tree onlvJ
Hgathkii HVU 202
iDom/VHf- Eri-g
Ken /Wilson
Lafavettif HA-14g
Mkllitnd 13-505
Regency HR-2
(^agarnrv HR-2ia
Regencv HR-2B
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Regi^jicy HR 2MS
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ROLI\ DISTRIBUTORS
P.O. Box 436 -'ftis
Dunellen NJ 08812
(201)469-1219
MODEL
CTR-2A
500 MHz
&1 GHz
^0 0.3 IB HB
1 US to
1 sec.
I. -.it
^ ' i^
1 0 mv @
150 MHz
Tha New Modo) CTR-2A Serl«i Countert ara daslgnod and buMt to tht highest stondsrds
to flJ^fNl the naedf of commercial comnnunlcationa, anslneerlog fabs and serious experi-
meniors. With an accuraty of + ,00005% Covan option} the CTR-2A can handle the most
critical measufementi and l« about half the cost of other connmcfclal counters.
If you need a reliable counter at an affordable price, the CTR 2 A \i the answer.
• BuMt-m Pre-Amp 10 mv @ 1 SO MHz
• 8 Digit ,3" LED Djsplay
• High Stability TCXO Time Base
• Built-in VHF'UHF Prescaler
• Automatic Dp Pfacement
• TCXO Std. ± 2 ppm
500 MHz Kft CTP-2A-500K
500 MHz Assembled CTR 2A-500A
1GM? Kit CTR.2AV0O0K
iGHi Assembled CTR-2ATO0OA
• Period Measyrement (Optionat)
• Input Diode Protected
• 12V-DC Operation (Optional)
•Oven Controlled Crystal (Optional)
+ .5 ppm
• Selectable Gate Times - ,1 8i 1 sec*
$249.95
349 95
399.95
549.95
OPTIONS ....
02) Oven Cryvtal
$49 95
03) ,43*' LED
10 00
04) 12 VDC
10-00
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06> Period 15.00
07} Handle 1 0 00
mmm
1^010
PROBES
Hi Z
S15.00
Low Pass
S15.00
DAVIS ELECTRONICS 636 Sheridan Dr.. Tonavwanda, N.Y. 14150 71S/874-5848
ALUMA ..„ i
TOWERS 1
VERO BEACH. FLORIDA 32960 |
MFC'S OF I
ALUMINUM TOWERS
* TELESCOPING
(Crank Up}
* WALL MOUNTED
* TILT-OVER
* GUYED MODELS |
[to 100 Ft,) 1
Excellent for iBE
Ham Communications. g||
1 HIGH QUALITY — LOW PRICES | ^
MADE rM UONG^ ^
LASTING Ki
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ALUMINUMl
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ANYTHING ON TRADE FOR NEW J
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Ham Gear. uM
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FOR SALES & TRADES CONTACT !|§|
R.D. McCLARAN SALES Ij^l
430 Frank tyn m Si*Jich 1 111? 1
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H Z
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LA5EB TUBES LASER TUBES
Hughes Etectron Dynamics Divtaion Model HP, 3124 Plasma Laser Tube. 4mw rnln-
Power outpur. .81mm. Beam Dia.. 1960vdc ± lOOvdc. lOKVdc starlmg voltage, With
Data Shee! OWLY l7t-95
BEACON TRANSMITTER
Microwave Associates Model MA-66C1&, An all solid stale high power fixed luned
C'band RF Q'^neralor.Thls unW is crystal controlled, and provides Irequency stabili-
ty in extreme ertvlronments- Designed for use in high performance aircraH and
ground based beacon appttcatJons, this device can also be used as an up-converler
pump lor microwave communi cations relay.
Frequency Range 6 0 W B.3 GHZ
Power Output 1 Watt Mir^. 3 Watts Max.
Frequency St^ility ^ 1 x 10-§
Spunous Harmonics '30dB
Input Voltage 24 to 32 Volts DC
ONLY SB9.95
HEWLETT PACKARD UHF, VHF,
AND MICROWAVE SIGNAL
GENERATORS AND SWEEPERS
MODEL S16B
1.a{o4,2GHZ
ONLY 1399.99
MODEL 618B
3.8 to 7.6 GHZ
ONLY £499.99
WHISPER FANS
This tan is super qu^ei, efficient cooimg where low a c^cHistfcat disturbance is a mu$t
Stze 4.6S" % 4.68" x 1.50". impedance protected, SCVBO Hz 120 volts AG
ONLY fS.9S or 2/Sia.0CI
MARCONI FM SIGNAL GENERATOR
Model TFlOfifiB^l 10 IO470MHZ FM or AM. Frequency Stability 0.002S%. Calitjration
Accuracy LO^. RF Output into 50 ohms 0.2uv to 200mv.
ONLY $799.99
TRW BROADBAND AMPLIFIER
MODEL CA615B
f requenoy response 40 to 300 MHZ
Gam-300 MHZ ledB MIN., 17.5dB MAX,, 50 MHZ 0 to tdB froin 300 MHZ
Voltage— 24 volts DC ai 220ma MAX
ONLVS14,95
HEWLETT PACKARD/MOSELEY
Model 2D X Y Recorder iV* x IT* paper with slewirig speed of 20*Vsec. 16 DC Inputs
ranges from 0.1 to 20v/Div. with Modet 7502A tine follower system control un(| and a
Type F-3B line fohower.
ONLY $^23.05
LOW PROFILE IC SOCKETS
9 Pin
14 Pin
18 Pin
t2 Pm
?4P^n
29 Pin
40 P>n
1-10
$.20
.17
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2S
29
34
48
1 1-50
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.15
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24
27
32
46
51-100
S1©
.13
15
-22
25
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MHZ ELECTRONIC KITS
Kit #1
Motorola CM1441DCP CMOS Tone Generalor. CMOS Tone Generator uses VMHZ
crystal to produce standard dual frequency dialing signal. Directly compatible wrth
12 key Chomeric Touch Tone Pads. Kit Includes the totiowing:
1 Motorola MC14410GP Chip
1 1 MHZ Crystal
1 PC Board
And all olher parts for assembly. NOW ONLY $15.70
KIT #2
Falrchild 9&H900C Pre^calef 3S0 MHZ.95H90DCPrescaler divides by 10 1o 350 MHZ.
This Kit ^ill lake any 35MHZ Counter to 350 MHZ. Kit includes the following:
1 Failrchnd95H90OCChlp
1 2N 5 179 Transistor
2 UG flS/U BNC Connectors
T PC Board
Aiwf all Olher parts for assemWy, NOW ONLY SI 9.95
CHRISTMAS SPECIAL DEDUCT 10% FROM
TOTAL ORDER. GOOD UNTIL JANUARY 1st 1979!! f
MODEL &06D
Model 612A
1
2
10 lo 420 MHZ
450 to 1230 MHZ
1
,1 uv lo .5* into
MODEL 692D
. 1 iiv. to ,5uv m to
1
50 ohms
2 to 4 GHZ
50 ohm$
1
ONLY $399.99
ONLY 1499.99
ONLY $499.99
1
KIT #3
Fairchild tlC90DC Prescaler 3S0MHZ. 11C90DC Prescafer divides by lOnoO m fqq
MHZ. This counter will take any 65 MHZ Counter to 650MHZ. or wUh a 82S90 it will
takes 6 5 MHZ Counter to^OMHZ Ktl ^nctudes Itie following;
1 Fairchitd 1lC90DCCn^p
2N5l 7B Transistor
UG-SSrtl BNC Connectors
LM;MC7S05 Vol targe Reguiator
50 volt lAmp Bridge
LED lnd<cator
PC Board
And all Other parts for assembly.
NOW ONLY $29,9$
FAIRCHILD VHF AND UHF
PRESCALER CHIPS
95H90DC 350M N Z Prescal er Oi vi de by i W 11
95H910Q 350MHZPrescalerDmdel»y5ffi
1 1 C90DC 650M H Z Prescaler D« vtde by W 1 1
1 1C91 DC 650MHZ Prescaler Divide by 5/6
1 1CS3DC 1GHZ Divide hy 248^256 Prescaler
1 1C700C 6O0MHZ Flrp^Flop with reset
llCSaOC ECLVCM
1 1C44DC Phase Ffequency Detector |MC4044pyL)
1 1 C24DC Du a J TT L VC M (M C4024 P^L)
llCoeOC UHF Preficafer 750MHZ OType Ftlp/F!op
ItCOSOC 1GHZ Counter Divide Uy 4
TlCCriFC High Speed Dual 5^4 Input NaNOfI Gate
CRYSTAL FILTERS
Tyco 001 1 9880 same as 219JF
10.7MHZ Narrow Band Cryslal Filter. 3d6 bandwidth I5hhz mmimum 20dB Cane-
width 60khj minimum 40da bandwJdth iSOkh^ minimum! Ultimate 50dB: Insertion
loss I.OdB Max. Ripple I.OdB Max, CLO ± 5p1. Rt, 3600 ohms. NOW ONLY S5.95
S a.95
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29.90
12.30
4.53
3.B2
3,82
12.30
74,35
f5.40
TUBES
S 32.25
2^26
f 5.00
4CXa50#^
S-SOQZ
74.50
4CxisoQa
250.00
3-100QZ
1&5D0
572B
33 JO
3S2S
5.00
eiiA
12J9
4-85A
54.50
5S94
3fi,00
4 125A
60 75
614€A
5.S5
4.250A
BO.OO
6146B
ezs
440OA
81,50
§360
7,99
4^1000A
255.00
6907
35,00
4CX250B
24.95
fl939
995
4CX250F
15.00
7360
1060
4CX250G
15.00
a072
45.00
4CX250K
35,00
aZ9SA/PLl72
150 OO
4CX250R
2900
8950
5JS
electroi|ic£
2111 W. Camelback Rd.
Phoenix, Arizona 85015
(602)242-3037
C.O.D. i^g
292
CRYSTALS
16.00000
49710
70KC
819
96
100
^50
285 714
500
S76
720
i.ooaMC
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1.229
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1.248
IJGO
137
1J99
r30t
1.33245
1.455
1,689600
1.7
1 7637 &
177125
1.773125
T 7B675
1.81875
1.5275
1 S4512S
184375
1 ,d45625
1 84576
1 S46
1 3435
1B49-75
S4245$3MC
5425
6 4270S3
^.45
6J7
6.47 HI
65T0
6537
6 567
6,5B2
6.612
e.6645
6B73
6 693
6.723
67305
6738
67512S
6 753
67562
67605
6.7712
677625
6.8^)000
6,910
6 940
T3S
7390
7,423
7.443
7.473
7.81
Q.O0754
6.00S24
8.075
8 12
S1S571
6364
8^
6820
6 8285
I.KTSMC
1906125
1925
1.927
1332
1 9B2
1965
19942
1 9f95975
1 964750
20000
2 0285
2.05975
2.125
2.126175
2 12795
2 1315
i 133275
213505
2.l3aB2S
2.1425
2.144^25
2.14675
2^140875
2,151
2153125
2T5375
2155
2 1 5525
2 157375
2 1595
216375
2.155875
2,170125
217255
2 174375
2 t765
217925
216475
21S575
2 194125
8 637MG
8.6455
6.^4
8 871
6879500
8888
6 905
8 9305
6 939
6,956
9,0265
9.65
9.7
9 75
98
9 85
9J
995
9999
10.0000
10071
10.20^3
10311
10,5
108(K}75
11 1S05
Tt.J28
11 2375
n.2995
11,3565
11,535
11.69626
11.71
1260902
13.102
132155
1 3. 2455
13.2745
13-2845
13,2945
2J207063MC
2^08313
2^09563
2-2lOet2
2210813
2.212063
2^14562
2-214563
2.215625
2.217936
221975
2.222125
2,22325
222675
222875
2.23725
2.2395
2.24075
2.241
2.246
22475
2.2925
25975
2330
2:320
2.32fi2S
2328a5
2.3525
235256
2 368
2.374
2.375
2.38725
2.395
2.396675
242
2-4375
2.44275
2 4495
2.45
24585
l3 3045iytC
13.3145
13-3345
13,3445
13.3545
14-315
15-016
15-036
16.80417
16.99958
17 2800
17.8710
179065
17,9165
17 9265
179365
17.94€5
17 9665
17.975
179KJ5
19100
1955416
2199965
22. '99966
23.25
23,575
2547867
25.99961
26 656S7
26 8965
28 958
25 9flS
27 77776
28 728
28.88889
29 696
30.0000
310000
31 11111
31 .66667
32.0000
246125MC
2 482
Z4m
2B
2,51375
2.581
2.604
26245
2618
2 62625
2.633125
2,639
2,63575
2 84325
2.646
2 647
2 650750
2 6545
2.65825
2.6G0
2,6^2
2.66S75
2 6695
2677
268075
2681
2.6645
2.68625
2.69575
Z7
2.702
2.704
2,71075
2,T^S
2,716
2723
2.730
2.7315
2.73225
2 7326a
2 733
32 22222MC
33.0000
33 33333
34 0000
344
34 4444
34 44444
35.0000
35 25000
35 55555
36,0000
36.21750
36.6666
36.66666
36 66667
37.0000
38.0000
3877777
38 77778
3888889
:»oooo
39-160
40.0000
4897222
49.95
50,14166
53.45
54.95
55.45
57.45
58.45
6945
60 45
61 95
72855
75
75 185
62 75
83
64
85.833330
2.737MC
273975
27*2125
27425
2744
2 7445
2.74475
2746675
2,751
2.754
2.75525
2-762375
2.7735
2.776625
2.78
2. 81 4
2.817
Za225
2835
2-854
2-^65
2868
28725
2.876875
2J87
2.889
2.894
2.910
2-920
2.925450
2.92545
2.931
294375
2.945
2.94675
2.952
2-966
2-973
2.980
2981
2-98325
90.833MC
93.1346
93.535
93 9353
943
96
95-35
102
106.850
123.5
146-4
146,54
147.09
165.5
LATE ADO
ONS
200KC
Z3WC
24
3,2
3.64
3.7S
3.60
5^455
7SH
7.15
728
7.5
11
22
29
30
40
2-9e7MC
29989
3.001
30235
3.045
3.049
3.053
30^
3.067
3.074
3.1125
3.128
3.137
3.13975
3.1435
3.144
3-145
3.151
3.1545
3158
31585
31615
316^
3166
3 16975
3177
a 161
3J825
3-18475
3.1885
3.2035
3.2072S
3.2105
3.2165
3.2175
3.23 IS
2.23275
3.2365
323775
32385
3 238875
3.23925MC
3.24
3.24025
3.2405
3.241
32425
3.244
3 246875
324925
3 24975
3.2515
3.255
3.256125
3.255625
3.261
3.261^25
3 26B625
3.271125
3^73625
3276125
3-3345
3-4045
3-4115
34325
3.4535
3.4675
3.4815
3.5
3.579545
3-72^666
3.7735
3.805
3.803
3.901
3.908
3.9166
4.O0O0
4.011
4.126666
4.26
4.3
4 6895MC
4 6965
4 7
47175
4 7245
4.7315
4 765
489
5.0000
5348400
5 426636
S.4366:u>
5,4990
5.4675
5/5085
5.515
5.5215
5544
5-S515
5559
55665
SS74
55815
5589
5604
5.619
5.61 15
5,6265
56415
5.6715
5,675
5,680
5,695
5,7
5,7105
5,733333
6 0878S
6 110
6210
6258333
6-321458
SPECIALS
FROM
electrof|ic$
TUNNEL
DIODES
TYPE
TD261A
TD266A
1^J2930
IN 2939
LIN 4 395
pRfce
S1000
10.00
755
7-6S
5,40
RF TRANSISTORS
TYPE
2N1561
2N1562
2N1692
2N1693
2N2a57JAN
2 N 2676
2 M 2880
2M2927
2N2947
2Nt2948
2N2949
2N2950
2*^3287
2N3294
2N3300
2N3302
2M3307
2143309
2N3375/MM3375
2N3553
2N381B
2N3e66
2^3666
2N3BeejANTX
2ISJ3924
2IM3925
2W3927
2 M 3950
2N3961
2N4072
2N4073
2N4135
2N4427
2N4430
2K4440
2N4957
2N4g6e
2N4969
2M4976
2N5070
2N5O90
2N5108
2N5109
2^f5160
2N5177
2N517g
2N5184
2N5216
2N5589
2N559Q
2N5591
2N5637
2N5641
2M5643
2N5645
2 N 5764
TBIMS:
All CHECKS anO MONEY ORDERS AftE «N US
FUNDS! ^m
AU. ORDERS SENT FIRST CLASS OR UPS
Please mdude ST 50 Mmimyrni Iqf p^atafle.
ALL PRICES ARE I NJJS DOLLARS,
ALL PARTS PRIME/GUARANTEED
PRICE
ST5 00
15.00
15-00
15.00
245
12 35
25 00
7.00
17.25
15.50
3.90
5.O0
4.30
1.15
li)5
1-i^
10L50
390
7JO0
145
680
1,09
2,70
4.43
3,20
6,00
trso
26,25
6,60
1.70
200
2-00
109
20-00
S60
350
2J0
212
19,00
1380
690
3-90
1,55
3,34
20 00
.49
200
47 50
460
630
1035
20,70
4,90
14,38
ItOO
27 00
TVPE
INTEGRATED CIRCUITS
ALL CRYSTALS $4.95
MC1303L
MC1451R
MC1469G
MC1550G
MC1560R
MCfSeSG
I4CI5G9R
MC4fl24P
MC8820P
2513
C2t07B
2708TI
$ 2,00
6,90
2,06
160
12.40
531
8 15
3.82
6.95
695
695
B96
MCI 4638
MCI 469 R
MCI 5606
MC1S63R
MC1568L
MC1590G
I4C6800P
MC66321P
TRieoae
TMS4oeo
TMS4024
$
5.40
5-15
3-55
10-20
10.00
5.00
&50
996
12-00
5.S5
6.95
13.90
PRICE
2N6a42
* 865
2N5862
50 00
2N5Q13
325
2N5922
TO. 00
2 N 594 2
4600
2N5943
1,75
2 N 5944
7,50
2N5g45
10,90
2 N 5946
13,20
2^6080
5,45
2N60B1
8,60
2N6082
990
2^16083
HBO
2N60B4
13 20
2N6094
5 75
2N6095
1035
2Ne096
19.35
2M6097
28.00
2f«6136
1870
2N6166
36 80
2N6439
43 45
MM1500
32.20
MM 1550
1000
MM 1552
50,00
MM1553
5650
MM1601
5,50
MM 1602/ 2N 5842
7,50
MM'i607
865
MM 1620
17.50
MM1661
15 00
MM 1669
1750
MM 1943
300
MM2605
300
MM2608
500
MMd002
2.05
nnnflicRjl^O
2 15
MRF304
43 45
MRF502
49
MRF504
695
MRF509
490
MRE511
6.60
MRF90t
3.0O
MRF5177
20.70
MRFeO04
1 44
HEP76/S3014
495
HEPS3QQ2
11.30
HEPS3003
29 66
HEPS3005
9,95
HEPS3006
1990
HEPS30O7
24 95
HEPS3010
1134
HE PS 5026
256
MMCM918
100
MMT72
.61
M(WT74
94
MMT?HS7
143
MMT3960A
% 625
PT3S3gB
300
PT4l86a
300
PT4571A
tso
PT4612
5 00
PT4628
5.00
PT4640
5.00
PTS659
10 72
PT97S4
24.30
PT97gO
41.70
PT9fi47
26.40
SD1043
5-00
SO1 116
3.00
SD1tl8
5.00
501119
3.00
40281
10 90
J10282
1190
40290
248
TA7994
50,00
C.O.D.
2111 W. Camelback Rd.
Phoenix, Arizona 85015
<602)242-3037
electronic^
MS
P^ Reader Service— see page 323.
293
RO. 801 4430 M Santa Cfafa, CA 95054
For wilUaironlv:<^«J«) 9^8-^640
2322 Walsh Ave
QUEST Cosmac Sup^r Elf Cofriput
Compare f^^atures tiBforE^ yqu decide la buy jitiy
Qtti^r corri'ptJtir. There is no Mher compuier on
the market lod^y that das aU the desirable bane-
Hts d r^« Sup Br Elf f fir so little mtsney , The Supet
Ell Is ^ small SI Jig It! board comput&r tha! does
rrany b^fi tilings. U is an &xcell«ni coinputer for
training ard iai learning progrRmming with ITS'
machine lanouags and yet it is easity nxfian^ti
with addlllonal ntismnrv. Trny 9a;li;, Ascll
Xeybosrda, yideo cMraet^r Qener^tiart, eic.
The Supflr |H mciurtes a ROW fnomtor for pfo-
gam loading editing and Execution witti StNQLE
STEP tor progrtm debiigfinfl «hicri i$ not \n-
duded tn mtwrs st me same price With SIHGU
STEP y0ti c^ sae the mic^Foprocessor ctiip
OfjWratir^ft wtti ttw iiatqpit Omal at^dfes^ ai>d
f^ bta djspliys Mm. do^iii and ilttr
tm&Mm lattrveions. Abo. CPU nMUte amJ ^n-
strudioii irycle are shown dt? fievtr^l LED indict^
tor timps
An RCA 1161 vMh pqiiics duo ilours y«u lo
CQHtf 1i} ymir ottft TV iridt n intxpnshft Mtio
mffifi^Dr to do gnptiks anf oiies.l1ier« is i
ipeihtr srii*B indatfid hjt utiting ]four r}wn
music or usuiq ntHty muse progrants already
mmm t^ speaker implrtrer may abo {i« uS«d
to dr*vs relays lor comt^ purposes.
A 24 liy HEK kt^mi includes 16 HEX luyt
pHis totd, mil; tm, i»piit. oremoiT pr«ttct.
Syper Expansion Board with
This IS truly an Ktoiindir>g valye^ Tliii board fias
\nm Otslgned 1o allow ]f0a ip dend^ hi3w you
Wfint It ai}lmncd. Th« Super Eipanslisr) BoHtf
ttiitiii with IK of low pnurer RAM kiliy [^ddie^sE-
ahle any whore m fi^K wtth buFli-jn mGmary pro-
lect and d cassette tn terrace Provisions have
bean madi} lor all other oprians on the eame
board and It tils n>Qatlv mto thei hardwood cablrei
alongsrdQ the Super Elf. The board inc^ljdcs sJot^
tor up to BK ol EPfiOM (2708. 275fl, 27 16 or Tl
271 B] and Is lully iQ^heted (Si2{]0 value)
IF ROM c:an be us^d lor tfifi monllor artd Tiny
Baftlc or otl^vr purposes
A IK Svper ROM Monitar $1&.9S is available »
in on tioifd pptmrs in 27Q3 £PROM vthkh tmw
bew prDprogrammed witfi a program kaHml
editor tn4 error ctteddfHf multi file £9SStt|«
r«td^irrlf software. Tfelocstible casMHe rwe)
artoctier exclusive from Quest h irKfudesfeglslir
tave iind rMOaut yideo i^ipiiic^ dnver niti
Mmhing cvrwr aid bliiqfi movt capabiMy Ifm
Super Monitor b wrilea witti su^ifoijiines aRow-
ISO ysirt to td04dwiage ot morntor Tunfiiors
er SI 06. 95
rr emery s«leci, rnonltor select and i ingle Hep
Large, on board displays provide ouiput and op-
tional lilah and low address. Tli&re iE a 44 pin
standard conr&ctor tor PC Ccird^ and a 50 irtn
connector tor I he Quest Super Expansion Board
Pow&r supply and sockets far all IC's are in*
eluded in the price pEus a deiail&d 90 page instruc-
tion nranyal.
Many sctiools and untvenities sre using the
Super Eff a^ a course of study. OEM's use It For
rrainmg and research and development
KemfimbfeT. otlier compufters only offer Super EK
hmires ai addiiioral m& or net at all Compift
Mora you buy. Sh^ Elf Nit $106 9S. High
idtfrefs eplion St, 35, lorn t^^rtti optlort
Sf.95 Cuttom Kardwpod C?bifte1 v^tjfi dnIlKt
ftKluip t^i S4,9S. A: «^.:^ d„ d ofFtiDOS also eomt
co<nf»lit«ir Msembled and tested
Quflilitala .'. \ ; £i^ montNy sotlware pputyitca*
bon for ia02 coo^Hjt?^ iis^s is ayHtabk by sub-
scnptkn fof S 12.00 p«r ytar.
Tiny Basic for ANY 1 802 System
Cuwtle ilQM- fk flOM l^ontior S3S 00,
Sup*t £F! owners. 30*- Qt* Uhiazlc^t llstiflf or
ptptr ta|w wnii manuil SS.SQ.
Original EU Kit Board S!4.9S.
Cassette Interface S89.95
vmply by calljno ttiem up. km prove m^nti and
revtsio n 1^ »o easily done with t he monil of 1 1 y o u
>ii)ve the Super Eipansion Board and Suptr
DAonitar tli& moniior js up and running at ttie pu^h
Of a button
Dther on hoerd options inctud^ Parallel Inpul
«nd Qutpul Ports wilh lull handshake They
allow easy connection of an ASCN keyboard 1o the
Input part RS 2 3£ and 20 ma Current Loop tor
iQleiypfi or athier devicB are on hn^rd m^l if you
need more memory there are two S- 100 slots for
static RAM or video boards. A Godbout 6K RAM
board fs available tor S 1 27. S5 Para I lei I /O Ports
$1«5, nS 23? $4 50, TTY 2Q mi tt¥ %^M,
S-ld014.5O ASOpiReaanKtarietwitniibbon
cable i^ tvaikbte M S12.&0 ^ eisy conn«ciion
bitwetti Uw Sipir Ell and the Suffer Eipmilon
Inrt.
The Power Suppty f or itie Super Expansion Soard
tsiSimptup^ly with-i-fiv ;r l&v + 12v - 5v
iegu£i!ed voteges ve ^5v S -i2v $29 96
Deluxfi imitQn in^u^ t1>e case m S3S 95
Auto Clock Kit $15.95
QC dock Hth 4-50- dtsptiy^ Usv^ NirtiOfql
MA-I0t2 moduh;^ wiU] alarm opbon. Indudes
Hgtitdimrnef ctyitallJiiclnstPtbOirTis FiJ|f
ngulidd. comip Instftcts Add $3.95 lor beau-
tf^uj dst gny c^e Best v^ik aiywtiere
RCA Casmac V!P Kft Z29.Q0
■. ^' ompuier *rtn garnes and Qraphics
Not a Ctieap Clock Kit iUM
IntluOes everv?ninQ BKcapi case, ?-PC boardE
6* 50" U 1) n. 5 plays, 53 1 4 clock cftip, lians^
lormer, all components and W instrucs. Green
and orange displays ai&o avid Same Ml w/ BD
dfiplsyi. Red only $21 (Jfi
Digitil Tempefstui^ Meter Kit
mdoot ir»d nutdoor. Swrttttes bi^ «na icfth
Btauftlul 50' LED reaciouts Mi^tnp iikee rt
avaiiibile. Needs i» additiofiaJ ptfts lor com^
pleia. fnH fipercton. ttni measufe - 100' io
^?0D"F. tefilhs of a degree, air pir liquid
Very accurate $39. &5
Seaut^ful ha^wood cse w l>e:^ $1 1J5
NiCad Battery FUer/Charger Kit
Qpen^ BhQned cells rbat wpn't hold a charge
md ihen charges ihem up. all m one ltd w/toll
parts md instructions S7.25
PROM Eraser
IJ II r*7 violet. assGmbled
$49,95
60 Hz Qrvstal Time Base Kit $4.40
Cotiveris digital clocks Irom AC line Ir&quuncy to
crystal lime base OiJtstafidlnfl accuracy. Kit Jn-
eludes PC bEjard. MM53B9. crystal, r&sistors.
capaptars and trimnrer
CiDcIc Calendar Kit $23.95
CT7015 direct onve chip di^pi^ys date and
time on S" LEDS with AM-PM Indicator.
Ala r m.i' doze featu re I n cl ud && b u Z2er Co rn p ici^i
witti all parts, pow^r supply and instructions.
less case
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0^4050
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Smclair 3^2 Digit Multimeter
B^.ACnpe^ tmVind YltAresokiMn Ftesn
mneeip3Drn^T%icaney Smil. portable,
oomfiiatelyassem. in tast. 1 yt. QuAr»niee Be$t
Video Modylalor Kit SB. 95
Converf your TV set into i t^iQti quality moniior
w^ttioirt affectum nonnat usage Complete kit
mih hj!] ins^udions.
Stopwatch Kit S26.95
■ i so. ^pt beltvy opcfaSed 2-5 vpfti
3 ?7&fl MJfe crystal acojrKy, Tunes to 59
mirt , 59 sec . 99 1/1 00 set TimtS «id , sr '
and Taylor 7205 eiup. all components nu^^^
FulT instructions
2.5 MHz Frequency Courrtar Kit
CoinplBtB liil less case $37.50
30 MHz Frequency Counter Kit
ComplEte kit less casa S47.75
.Pn^scalgr kit ta 35Q mi S1fi.9S
1978 tQ Update Master Manuat
lB7a IC Lipdate Master Mnncjal SSO.OO. Com-
plate fC data s&lector. 2i7l3 pg. Maslitr rafer-
ence tjuide. Over 42.DDO cross references
Free update service through 197S. Oomastic
postage S3. 50. Fp reign $6,00
0 Connectors RSZ32
25 Pm Su^minkittUf^
DB25P
DB25S
Cover
RS232CQmpltt&£et
2.95
3.§5
150
QE9P 150
0E3S t %
0A15P 2 m
DABS 3 10
S-100 Computer Boarils
BK Static RAM Kit $127.00
16K Static RAI\^ KH 265 00
24K Static RAM Kll 423.00
33K Djfnamic RAM Ktl 449.00
64 K Dynamic RAM Kit %A^ m
8K/16K Eprom Kit (less PROMS) $89,00
Video Interlace Kit $1 39.00
Motherboard S39, Extender Board $8.99
TERMS: SS.OOmfn. order U.S. Fundi. Caiil residents add G%tax.
BankAmericsrd and Matter Charge ac^pleft.
Shipping charges will Ite added on efiarge tards.
FREE: Seiift (or your copy o1 our NEW 197B
QUEST CATALOG. Include ZBm stamji.
294
GALUUM PHOSPHIDE L.E.D,
Provjdes Higher fnterisiiy Tf»an Regular
LEDs, T1-3/4 Dome i^ed Dif*ysed>
AND Part ini4R 199 .,22c 100+ 20iE
We Slock th« full Una of AN O L.e.D.'i
^^MSSw
< I I I I • • I
DIP socicrr specials
1^*9 50-
ifi Pin Lo* pFoliie Scildw Tad 20t \bt
IS Pin StandftfdHetflhTri Sotdin' Tab Z5C JOt
24 Pm LOW PnjJita Soktef Tat) GOLD €0t S5c
CALCULATOR GIFTS Experymeiv
t^f's delight. Ea(;h kevb'Oad ir^cludes a
monoEirtiic calculator cliip and d display
These are rejects. II might be somethina
simple to repair or H c^Quld be very nasty.
At thfs price, who cares! 9 voii. lt.SO e«.
5 FUNCTION L.C.D.
WATCHES FROM NATIONAL
Seconds
SEMICONDUCTOR
• Hours • Month
' Minutes ' Date
(Gofd) Leatherette Band; f Chrome) M&ta^
Band; (Goid) Uelu\ Band; (Chrorne)
Leathereite Band. SId.OO EacSi, Specify
Model (Add SI 00 For Metal Sandl
A SPECIAL FACTORY PURCHASE!
rNSTRUMENT/CLOCK CASE
KIT Per! eel foc youi opto proiecia. Solid
aiumnnurn construction with real walnut
sides. O O safS ' tfy 5^3/8" by 2". S6.95ea.
50 20B 10
aWCH 252 10 30 1'
EDGE CARD COMiECraR
C nch Jones t0^20 Pms .156 Spacing PC
Mount aSc
Electronic
^U9
A dtviHiDn
1' united ^incducts
Corparatiian
Corp. Hdcfts., 2322 i«t Ave., Seattle, WhIi. 9S1^1 • (^OfiJ S«2 5025
INSTRUMENT/CLOCK CASE
KIT A reai j^evuei for thnose smaUer proj-
eels Hiriged top door allows yoii to tiide
yoyr conirol area. 0-0 4'/i " tiy 4" by T ^^
$1 50 ea
EUROPEAN 220V LINE CORD
Building something for export? Then fou
might nee-d tht$. 40c ea. 1 0^53.00.
TRANSFORMER Pri hdvaGScc
1 1.2 and 5 VCT @ 1 amp. 95t ea.
TRANSFORMER PC mount prl
110 vac Sec. 12:G @ 1 amp. 11.25 ea.
CLOCK DISPLAY national
SEMICONDUCTOR B digit multipleKeo
display Vt" char acters. (Common anode)
A real buy at ju&t SI .00
5 FUiiCTiON L.C.D. CAR
CLOCK Wan fio longer. We ttrought the
price do^n on UC.D.s. This is not a kit- It
comes completeiy assembled, ready for
you to easily install in the dasJh of your
car, twat, or R V. 5 functions, ;>rovidiFig
hours- minutes- seconds- month and tiay.
Power fS provided trom a simple pen light
cell which will servjce fof about t years.
Ml grit lighting is through connection to
your eKistmg dash lights. Time accuracy
To 4 seconds per month. You wonl fieed a
magnifyjng glass, to see the time, either
This beauty boasts a big Vi " character
dispi^ay. Which, inctdentatly, has passed
the lemperature est ( r ernes encour^tered in
an automobile. Battery not included.
S24,&S
8PECTRA<STR}P
bon cable *22 sirancj&d
*Mt...i99;50t. -100
Muiltiicolor t\h-
20 COfid 75c a
mm
rr
36 PIN GOLD-PLATED
HEADER Break olt Id desired lengrh
Has dip spacing Ust pnce Si 36 Your
price 65«.
PLASTIC PARTS BOX a mce nme
" ' ^ed-iop boK tor sioring all your ^nali
,.^rts Oct, %^Jt by 3^/ by ?" 7S« ea.
1(V$S.OO.
COMPUTER POWER SUPPLY
TRANSFORMER pri itQ.720 var.
SEC. 12. 1 V it 9 A, 44 a V ,i 2 5 A. 1 2 9V :
2 0 A, 12.9 V «rs 3 2 A Only $14.95 *i.
EDGE METER 100^ too ua 1/2 ' by
11/1S^ Compare with other meters
costing SeOO- ONLY 12-00 •m. Why pay
iTigre?
CALCULATOR BUBBLE DIS-
PLAY BRAND NEW pocket calculator
disptays Flanging tram &9 digit Youf luch
SI 25 ea 3^3 00
KEYBOARD HOBBY SAG Com
pare, then really save wiih our calculator
hobby bag assoftmenf Each one contains
3 calculaior keyboar^j^. All this for only
Sl.TS.
TOGGLE SWITCH j b t #jmt
423 1 Subminintura 4 P.D.T. S amp. ;>t<
125 VAC LIST PRiCe $5.95 YOUR PRICE
$1.11 ea.
REPEAT OF A SELL-OUT A com
pJete 12 hour digital clock. Some are m^tr
ufacture line rejects, some are returns,
and some ara ju$t scratched Features:
houfS' minutes- alarm- snooze alarm
Parts value alone would equat $20.00. you
pay only ie.OO an.
%# Ut ''■-■ 1^
DEFECTIVE CALCULATORS
Well, some are and some are not. We tan ';
afford the time to test them ^ZSO ei. Bal
re^ es not included 2^,00
#30 KYNAR Bik . Brn,^ Red . Or . Yet,.
Grn , aiu . Vio . Gry., Wh.
We will do OUT b«9t to sti'p the co^of you
specify. To ensure prompt delivery of your
order we will substitute colors should we
be temp, out. unless you specify olhef-
wtse S2.3fi per tiundred foot spool:
Sl4.1Gper inousand tpot fi|K»1;
MulLiplesol 100' «n|y.
Call ua for quotes on larger quantifies.
!
''
V
l^£ I I I *
III I I V
PARTS BOARDS a great waf to buy
parts on a biidqet We guarantee youf
money's worth, ^NLY S1.00 aa.
CAPACITORS
Capacitance
Voltage
style
Price
lOOOtil
25VDC
PC
25€
220ut
25VDC
P-C
25e
2000u«
25 vex;
AXIAL
50e
40^40
150 VDC
AXIAL
45c
luf
15VE>G
AXIAL
1^
-Qie
icov
MYLAR
25e
001
100 V
MICA
11*
01
DISC
7c
.02
DJSC
6c
-1
DISC
9c
A CHRISTMAS BONUS Free with
ewery S50.00 purchase this manlh One
each National Semtconducior LCD
men's watch that you see advert tsed on
this page. Hurry, this oHer e?ipires
December 31.
DIPPED TANTALUMS
Capacitance Voltage ToL%
luf 50 V 20
2,2uf 50 V 20
4,7uf 50 V 20
22uf 20 V 20
We stock the full line of
MiCONICS dipped tantalums.
Price
42(t
62i;
5H
SELECTED VALUES
Those ilems are chosen from our vasi in-
venlory of industrial quality components:
Extruded heat sink 10 7/8" by 2 1/4' by
5/e" - .$1.49
500 Ohm PC mount irtmmer 2Cte
L me cord #1 B ga 6". . . . . . 25c
74LS1 75 Quad D Hip-flop 50«^
S P.D.T. sub mm slide switch. 40c
s p ST PC SWITCH aoc
EKiension speakers 18" cabinet Ipatr^ .
51^.00
ACID BRUSH tOe
SWITH #8523 SPACER 5 by #8 hole &S
2 cond. #24 spiral wrap shid. cable tlH
For Master ChargflA/iaa
Ordurs U&a Our
TOLL FREE HOT LINE:
1-eOD-42 6-0634
for arees Qutsido Washington
[inci, Alaska & HawBiQ
O^E.M.'s WELCOME
L Hi aju Mim J ¥vmi
Store Hours MF 9-6* SAT 9-5
p^ Reader Service^WBe DBoe 3?3
295
BiLLEI ELECTB«IIC§
P.O. BOX 19442E DALLAS, TEX. 75219
(214)823-3240
SC^i.-iv'i
->:
iji-:^^
ti^Ei^e*::;-..
^:>^.
■■*- ■■■ j
MINI GHANDFATHES CLOCK KIT
J %*
Wi
ChimK ths hoar ftp: 3 times fo* 3 O'doc^l
Unic|ue "svimnpfig" LED fHndu^um
Tick tock KHmcf mitchcs pendulum swing.
Lirge4 digit ,5" LEO rndout
AHCMOS comstfucMofi
Compl«t£ €LectrooiCt indudifig irinifprTner & ^xraker,-
drilted and plated PC boiifcfi me«ure A.S** x 6.S"
BEAUTIFUL SOLID WALNUT
Custom case for Above kit Ov^r 9^" tait 1 jr#V5
POWER SUPPLY KIT
PS-14
39.95
^f ."J
la-.^,^
<j.j
* Setter than 200MV N»d and line regulation
* FolifiiiKlt Cufreni Lifniiijig
' Short CifCuil Protected
* Thennal Shuttkwn
* Adjuittble Curmenf UmiiJng:
* Lnsdian 1%npplt. ^* ¥
* 15ampi11,5to 14SV
* AIT pam tuppfied including heavy duty trans-
ffirmer.
* Quality plated fitHrgien PC board.
REVIEWED IN 7/78 73 MAG.
15A CONT.
,hG
20A INT 42.95
mi
MP-
NEVEH A SWEETER
METER!
Beautiful Amirlcflii mid« panel
rnelers are a snap Co install Hug«i
3"^^" vv^dfidldjs ar*0AsyiDreftd Y{>u
woukf exped lo pay mor* for each
than me geE tor the pakr^ MATCHED
SET {M5VDC, 0-30ADC
OVERVOLTAGE PROTECTION KfT
6.95
Provides chnap insurance tar your eKp^nuvB ec^ufpmfnt
Trip voltage n adiyntab^e from 3 to ^ volts. Overvolt^tfe
instafitiv fires a 2SA SCR and shom the output tti protect
equipmefit SHould be used on units that ^tb fu^. Di
recdv compatible! with the PS \2 and PS T4. All $l«ctron-
ici supplied. Drilled and plated PC board. (Ord^rOVP 1)
l'*'j
>*j
r^i
i
J^£^«l@&:]Sf^l21S^»%ifiCiI%^^^£l
■a^v
♦*jHj
.^..'
■ 1^.,
■-=.■ jlJ "'-' i."
W
•^ •^^.
'j\^ -it^
_*v-
MK-05 MINI MOBILE CLOCK
' -r vrtatiesT mil hen nn^tsii ittc^iic ckK>
PEATUftES
-' cfy*«1 iitf%lMtt
T,.i.H,j & /etwr rkQPSFSEOvervoltniefirQiacttcin.
- Udijrtkr^ed IS". 6 digit LED rualdtiL
' Compleif KHitfi pnwiuhte 24 hr , alarm.
' 9-t4 VDC#40ioS0rfia, HQ Qf>
• EASY, QUICK ASSEMBLY
- All c&itTparrents ri&cfuir«d meluiliHl [you upplv the
" Top qui^1^Iy drlllod and plaiett HC bo«rd>
aoc*<hoard 2.6" « 2*
Readout board: 2 3/8" » .75"
tnaynl I'l l^i#
iFi^ll-unMHl pinifl
UNIVERSAL SOUND EFFECTS BOARD
mm 1DU EVEB a> YOU could duplicate the so^j^iu of a steam
TRAIN OR k PHA30R GU^^? HOd ABOUT GUHSHCfTS, TlES, SIBENS,
:iARKING DOGS 4MD OTHER SOUND EFFECTS? NOW YOU CAN WITH OUI'
PBOGfiflMIABLE SJMD WFETYS iOT, U USES THE NEW 28 PHi l.l. 93UN[^'
SYNTHES¥ZER CHIP, SN764T? AND SUPPORT CIRCUITRY- 5 TO 12VDC IS
HEQUIRED m GIVE AR'HQX. 1/4 rfATI OF AUDIO OUTPUT. li€ PROTOE THE
PX. aOMD, PARTS AND DSIRUCTiOrC ALOWG WITH A CHAm" TO PROGRAM
SOME COmON SOUNDS. USE YOUR IKAGI NATION TO CREATE ORIGINAL
SCXJND EFFECTS. ORIHR: SE-01 14.95 tb-ss Spkr.) 3/39-95
Si
r^rf
mmm^mamMMmm^
n
6 DIGIT ZULU CLOCK KIT
Al East a chod<; for HAMS. Designed wrth ler^e bright LED digrts to enhance
your shack The unil 1$ a ple^osurcp Ea tig^^mble and S4? ea^y on tiie bnidgelf
Yqm |}el lop quality parts and plated PC Boftrds Ttie uriique design of The
E>o^fd le-r eOmrnat^s ttie headaches Of running wtr^ between docfi arvj
readout lx»riEt M a bonus Ule uniil has a e«i4chtf|ita ttnier that ca^
£anDwiltiout«istuil]ingrealtmie Elapaed ttme m mtrtiles and ae^svufe up to
25 mtmices. Si« tut S(Z&d FND510 raadoiits and^oitona makjng viewmg e^s^
(torn across Itie room. Does HO^ use (he oU sty^ 5314 chip. DUE TO A
SPECFAt PURCHASE WE HAVE A LJMITIO QUA*rnT¥,
M
■'-''•' -tJi-*|
■;>At>ii^?;?^!-?^*
- 1
-WMBLE ALArM Kit
A fun EASY kit to assemble ti^a:t emm an ear
pwrcing 10 watt dual tone icream, Rtsemblei
tufOp^an ifren sound Great for alArmt or toVE-
Operates from S-12VDG ai up to 1 amp lufing
!2VDC*B ohm speaker). Over five thou»nd
have been sold. All parts includin<i PC hoan.^,
COltPLETE ZULU CLOCK KIT
Irrchjd&s; AH cwfljw-
n^fUbv plfifeiKl diV'Sd PC
8o«ilB> laiv* ftMy to
eaa snuuuHPBi, wim*
AC transiorfher. Ooos
t>oafd: a*i" X 4*1".
F^eadom Board i^" %
24 Hr Fofinal Only
Hand made loMd
haidwDCpd case for the
Zulu Clock lnclud#a
ru\^ front filter oAd tMdi
panoi
6.^
^M
Lf Li
MK-03A CLOCK/TIMER KIT
Features 34 hour Zulu tSnw arfd up \o 24 Kours of etat^ttd
time on the same 1*1 of iiJ( diQtt LED redouts Tuuflv
independent ofjeration of both functions. Clock hoi pr^'^
settabTe aldrm with 10 minule sioofe. Timer h^ resets
hold, and cquni fufKtKyns- Fulf notse *nd overvoltage
protecleoci. 24 hciur onfy. Readout has dimmer featuft
or thev can be iurn«d off mthoui dmurtHing tt»e chTiNk er
timer, Timebase iiKludtd 4 J}1% accuracy K Bec^ioe ol the
many optrom and rrwtintjng CQtfisidenitions Ifie case «^
nvitxii^s are not irtdud«d S^^rtches are aandiad tvps.
Wilt fit inadfe VOfldard aircratt insafument cse.
i? 14VDC
t^^^
28.95
■^v. ~.
J •.
■^*,
.*;^
MOBILE CLOCK CALENDAR KIT
:^cv>-rT|, iah<! Bifervtiodv Mil 1 1 fiijQMial floe^ fc^V. M0««Tv«f
we hiwii ittft u^^v ^Qvv cost DIGITAL CLOCK i
CALENDAR ror Motrilw omrition Wa providB quatjtv
plated ihrOiiph- h^yti^ bo4tdi9 and (te^y-by ftep intv^r
tiCinf. parfi vvariflVi and lehefnatici. Ttiii cliKk hdA
ipe*li«f , PimtHtlc 'or c»r, tietT cur v»n.
^^
*r 1-Jt, n^, APO SV STATE SALES TAX
* FOflEIGNQflQEnSADOIOH
i3CHLAIflMAJLtU£ f UHfI3S Q*lL¥.
1^
* NOC.DD.S
* semdcheckm.o ancHAnai tAi^oNq
* PHOME OnOERS ACCEPTED ON
V1$A ANDMASTtTlCHARGf O^UV
.■1 ;A'»!w^j|f"'J
i£ai
(.PIS ACC5
*LKf9i4 DIGIT LEO
ditplav -A^llh AM/PM
indliCiicirt
■>PI«hlnEi CDtQimt 1 hi?
rrftfl
»S[j«cJil noiiif and
ov4ifvc»^riiii0 ntoiaE<tLon
tor rtiotviirt ma
'AuxJIIarv DiJEpul wIM
iJrlvi t9\m>i df TRlAC
iDCantroL imtOfnal
vqullLiFTi^nt
'^^^^:^?i^^ii^";j
*fluJ4i jn Ignttion
bl«n'k;)iig turns
off readQiits. when
•PcftiiB-ltptjIii elsfm with
•Spflc i a I ' 'S^eep T Jm^r'' '
23.50 Mo CASE
1 2 VAC XFMR for 1 1 0 VAC
t 50
24 Hour f orTTiBtfldd
Z.OO
296
f_l — '
ELECfB^IICS
(214)823-3240
RO. Box 19442 E
Dallas, TX. 75219
"' " TiS!L>Tyj
jjcrr*^
sS--JAiJL
■.kin, MM
TT-
Fi-'*
1N4003 ?00V lA 1S/1.0O
1N4006 BOOV I A 1t/t.00
1N270 G«rmflnlum Dbde i/1.Q0
1N38A G&rm0r>iurn Dtode 10/^100
m414a Cul& Sort for
PC Bc>ard Insertion 100/1,25
UNMAnKCD POWEfl DIODES witti
calhode bands Gu^anieed to t>& ^i t«Mt
400P1V <© 1A 100% Good parts. Epony
case
2S/1JI0
L.^1
NEW rrEMS:
MViea* Varicap Diode lOpfW Norn ?t
Tunmg Ran^e 49€
2NSS83 High Fr«q Amp 1 W^ft @ 1.S
GHZ' TO- 5 Case sly la. House # 50(!
MFC400aB '4 Wait Audio Amp 4 pin plus-
lie pack SOc
HllOlOa 100V 3A SCR UHra ssrisMiv©
gate drives Irom TT1_ TO-220 SSe
Mf03SS 50V 3A Tnac Sensitwo Gat*
TOS 40€
•X*^.
r- -- .'.'
l^rit'y
V-1
■• 15-.*/- -- -3
sST^y^^;//.'^;*^^
;^■^i:-
^-.\;
Tv'fj^i^
FND510 %m
COWMOH 4HOOB nCAOOtiT V
»■<>♦ I T PPi
LEOS
JUMflO flED 5A89
^Gi^ettM 4A89
MINI
HED .10
MEDIUUI HEQ A§
V£1.LDW J 8
1 1V 113-30 mil
MCI 3511* FM-IF AMP
ANO DISCFLIMirVATOR
ySEE> «*l FW 4 TV SOUMD
Circuits reOuires ufn4-
NEMtS U PIN OPP OtRECT
REPLACE MENT FOfl hEPC
OWa, ECG r49 and MANY
OTHERS HOUSE 4i
WITH vecfl 50*
MC3301P HOUSE i
4 CX" AMPS m OMi PAC^KAiQlE USES
JWTEfmALL* e>dM*CHSATtD BnuuiJtH
TP UCMOl BUT MhQHtl^ OJkm. 4S«
AtL COMPONENTS \Q6^
GUARANTEED
CAlOtI WtDESAI^D fF AU^ * wspci 50C
^CJSiE@ MPN EPOXT IW 8/1.00
m OPAWPflPtNOfcP 5/1.00
r23 voLTJNsefleo mpinqip 50*
Mpsssao NPN HOUSE « SV1.00
TSi OP AMP tow NOISE NdUSE* W*
JTI16. 1BV 1A flEOULATOR HOU&E « 63t
LM240T-13 ISV 1A vai*T REO w/ioec* 7SC
TCAi30 QUAD OSCIUATOH IVipBtn 69t
2N<343 P CHAHNiU J FET 4/1.Q0
ZMS111 PNP MED PM11 4J3W Tt^-ZZO 3/1.00
2NGQ2« P>ROORA.MMAlBL£ UHUUMC- SO^
TlON nf/t^eca
TH1AC ^?tW\' tA UTNUtAWKf □ 3l/1.0l()
J^.-:
'..-l-'i'.
1iC14«9fl POSITIVE VOLTAGE
REGULATOR
- Aitf* C ^'' . t TB f^ECa *MD
RXED on vApuaiE POWEn %^v%^
^TCM 3 TO »VDC DPivE EXTlfKU
SEHiES PAS FOR CUH%l>iT jg 33
t.2S EA,
taMQ.OO
MQySE I
Perfvei for battery
chargers, switchmg
supples, crowbafs. dc.
*flrtP^.
739 FAIRCHMD
DUAL LOW NOISE
AUDIO PRE' AMPLIFIER
890 2/1.69
MOUSE * PNP POWEF^
ir^wAtrs
FDEKtlCAL TO 3tcVW 1 J>0
fMPFiai H-CHANNEL'
DUAL GATE iiOSfCT
OCSJONEDf on A*»tmEff *WD
UIKEfl APPLlCAffCSHS TO WO
wtHZ PLASmC CASE UI4!T^5
ARE NOUSe NUMBERED WtTM
S*E<^
fcL^^-^A
^ i iy^
FANTASTIC SOUNE> EFFECTS
CHII*
THIS S& F'J^ WAAvEl dOMtAlMS A LDrt
paEOuCxCVOSCHLATOft VCO NOJSE
OSClt±jHT{?n ONC SHOT WIER *hD
EJfttLOl^ CO*it«Ol DWTW ■ PAGE
EMITTER
RESISTORS
HAFID TO H(^D
VAIUES*
.t ohm@5W
.25 C3*im @ SW
VOUfl CHOICE..
7/1,00
^1|]CSCW-fllH'TW^**™**'"*Tt»Ti I*
LMBSiOOQUAD
NORTON AMP
)fit BDUGHT A LAROC
QUAMTITV Cff'TTHESE HCKIS£
■vgunS^D PARTE ifhT A
BARGAIN PfllCE THAT
AJLLOrirS US TO SELL ThEU
AT A LOW LOW 3l9«
j.^^lriKSVniM'C^^tM'W'
'.i..i.^>i
(L-1 OPTO iSOtATOWS
BY LlTRONm A Pi** DIP
STAWtlftflD PmOUT LED
tpAN'^'-.^STOR COMBIiJATI W>M
50<
WMIL£ THEV LASTt
'^
t-'
WIREWRAP Wire
50 Oatigt
KYNAR^Intylat,
500 FT
4.SO
.H'l
^
LTf*
S>^*^
"■ ■'-
.022
.Imid
.4l7mf(i
33fTsM
CAPACITORS
flADIM.
i/tjoa
SOO MFD @ 35VDC
S/1,00 AKr.^L
£3D M-FD @ »V1PC
7^t.0O AXKAl.
1 MFD 4^ ZUV'DI?
OlSe CEfiAMiC
15/1.W
IDOVPCMv'Jer a/1.00
BOVPC Mylar 6/1,00
4I>0VPC Mylar 4/100
35VTantAxi«J 6/1-00
3 & V TanT Ax !■( 4/ 1 00
3£VTantAKial S/1 00
30V DifiTant 4/1 OP
10V DioTant */1 OO.
-i'%^*
ZEHER CRAB BAC
A very nice assort ment of ^A, *4
& IW ieners Voltage ranges
are from 2-7 to 30 VDC Most
hova house # but we provide a
cross over list to stand'ard
numb era, A great buy for any
shop 12 dtrfarenltypes.
690
IT-
'S
.<s
-"- ■^— ^'
'^*^-- ^ ^^-
:a«^
'>r^'ij?g*">-«5'_yig^^^^^^^y
JWfC^IBC
-NO COD'S -ADD 5% FOR SHIPPING
'SEND CHECK OR MONEY -TEX RESIDENTS ADD 5% TAX
ORDER OR CHARGE CARD NO, - FOREIGN ORDERS ADD 10%,
PHONE ORDERS ACCEPTED ON VISAS MC
-ORDERS UNDER SIO.
ADD .75for HANDLING
COPYRIGHT
%^ Reader Service— Me page 323.
297
FREQUENCY COUNTER KIT
CTSO f iiEQUi»£>fC04m«
Outstanding Performance
CT-50
„T,Sn JU""''"^
Incredible
UlM
*
The CT-50 IS a vefsattle and precision fra<|i#ency counlef whicfi will measure Jeeuf mSu
freqtiencfes to 60 mHz and up to 600 mHz *t|h the CT&OO op^on Large ScaTe st»b»h^2 0p!f
imegration CMOS circuitry and softd siaie display technology have er^a&ied mts counter lo \QmpermMm
malch performarvce found tn units selling for over three limes dS mucf^ Low power '*^3ut Bf*c i n
C©ftsump!ion (typically 300-400 ma) makes the CT-SO ideal ?or portable batlery operaiJon 0¥**t»d &0w^
*^«?aiure5 or tfie CT-SO incluOe large 8 digit LED display. RF shielded an metaJ case, easy ^^lUi""^^ *™
pushbutton operation automatic decimal point, fully socketed iC chfps and mpu* pfotection Powv tio va«
to SO volt? to msure against accidental burnout or overload And, the besi feature of all is the stj* 6" « r- «
easy assembfy Clear step by step instructions guide you to a finished unit you can rely on CS i3unii» «
Order your to^jayt
CT bO toO mHi tounler ki! tit.i! t;a,i Color TV calibrator fltabiltier
ClbWX 60 mH/ CDgnief wrt(?d and leatad 1$t.9G DP-1 DC probe, general purpo^ probe
CT600 600 fr\Hs scaJer opiion add 29J5 hP-V High imperiarice probe (ion loadir
SPECIFICATIONS:
Fieqdj«f<icir tan^ 6 H2 tti 65 mHr 600 mHi *«rH CT-^&OQ
nnoiiADn 10 Ht r. 0 1 sec gsfe t fi]^ c^ 1 wc g«te
naadOitf 0 d*git d 4- high LED ^»r?cr rtm^wt m «nHt
Aecuracir idfuslAbie lo 0 S ^pm
St«b»^it|r 2 0 piim over 10 to 4D € lemperAtyf*
conipermated
lA^ut Bf*C 1 megohm ?0 pi dirBcl SO ohm wflh CT-60C
0¥«4lO*d &OVAC maxuTni'n, aft modes
SensiUviTY ^«s rhan 2S <Tiv m £5 mHf ^O-tSO nnr to BOO
Ptsmwt TIO VACS Watts qft2VOC(- JOO nw
StJ* 6" X 4^' a ^*^. high qualitv alum mum case ^ 11^
CS 1 3 unii». all sockeled
1SJS
IS.ftS
CAR
CLOCK
OP-AMP SPECIAL
SOS
741 mmi dip
BT-FET, mini dip, 74r typt
t2/SZ.OO
10/SZ.OO
Tht UN-KIT onfy
5 iold«r coo necl ions
Here s a super looking, njgged ^nd accurarc^ Auio
cloc^ «h»ch IS a snap to biriid and tns^aii Clock
movflmg^nl tscDmpl&tety as^fTibi^eHl— ycru only fOtd^r
3 wires and 2 switches lakes dbout l& minui^^
Oi^pfay i-i bright green waih auli>matic tKighiness
cortlrol pfHiloc ell ^assures you of a higtily readabJi?
dispfay day or ^ight Games m a Katm hr^ifti arn-
odi/ed .Aiufninuifi case At^ich can be attached $
dftrei'eni mrays usintg 2 sdecs tape &\gk9 41 f silver
tilaciii or gokl ca-^ (specify)
OC'3 M 13 nom fontta! S13 9S
OC'3 «rrred anil tested S29 9S
1 10V AC adapter (5 JS
Under dash
car clock
12 24 hour clock m a beau-
tilul pidslic case ieatures 6
jumbn RED LEDS high acctiracvt^rniri mo J easyS
wire hookup display blanks *ith ignition and super
infttf uctJOns Optjonal dimmer automaiicalfy ^d|usis
dtftplay to anibieni light level
DC 1 1 clock vvith mtg bracket 52795
DM 1 dimmsr i*dapJeT 2.50
PRESCALER
VIDEO TERMINAL
Acomplelely 5eff-conia,med stand aione video ler-
m+ral card Requrres only an ASCM keytioard anrf TV
set to be-come a cornplele lefminal tjnit. Two units
avallatsle, corrrmon t^mlnrei are stngl-e' 5V supply^
XTAL control fe<t Sfyrvc and baud rstes (jo 9&D0)
complele cortiptoter and keyt>oard control oi cursor
Parity error cofitrot arH3 diftpisy Accepts and gener-
aii$s senaJ aSCN p^ui parallel keyboard inpui The
3216 i» 32 cftar ty 16 ime*. 3 p«ges with Tvemofy
durnp feature The €4 1 6 i» &4 ch«r by 16 Ufnes, wilh^
scrolling, upper aiKl kim&r case (oprronaO artd has
flS-232 and 2Dnta toop mlpttaces on baard Ktts
inckide sockets an<i cornplete documentatiDn
HE 32t6, tetm^nal card S149JS
RE &41 6 . tefmin ai ca rd 1 ifl.ifi
Lower C«^ optKjn , €Ml 1 6 only 1 3,S5
Powef Supply Kit 14.f S
Video Rf Modulator VD- 1 «,9 S
Assembled. Tested untis, add W.M
CALENDAR ALARM CLOCK
The clock thai s got it all 6- 5 " UEDs 12 34 riour
snooze 2 A hour alarm, d year cakendar, tia11eT||r
backup, and lois mofa The sup-ar 7001 chip is used
Complete krt, igsscdse (nal avail'sble)
DC-t $34.95
Extend the range of youf
counrer ro 600 mHz Works
wilh iny counter Includes 2
rrans^stcr p re-amp to give supei sens lypicaiiy 20
mv at tSOmHi Specify - 10 or ^ iDd ratio
PS- 1 6 600 mHz prescafer S-S9.9S
PS- 1 B%. 6^ mHi orescakt loi 49.9S
30 Watt 2 mtr PWR AMP
Simpte CIBS9 C powar amp features B limes power
gain l Win tor flout, 2 in for 15 out 4 WmJor 30 out
Max output or 35 W incredible value complete with
aM parts less case and T-R relay
PA-t 30 W pwr amp ktt SZZ.9&
TB-t RF sensed T-H relay kit 6.95
Ramsey's famous MINI-KITS
FM WIRELESS WIKE KtT
Trdmm<ts up la 30P' a
fo *ny FM broddcasf fL
tadio Ides any typr d it^n^ '
fTifit* RifTn on 3 ro 9V jr*«K
r^'f* RW-j tiati >tM«l 5ef>- "^^^^^^
wfrwe mrtie preamp stage 1
F M- 1 kit $7 9& FU-2 kit %A »
VIDEO MODULATOR Kit
Converts i/»y tV to *«leK5 maniJor
*^fiwf su&ie tunaiUe cwe^^ ch 4-6.
on StSV accepts sfd video
-hit VD 1 SC-tS
SUPER SLEUTH j^St^
A sup** M,'- " ' j^Ri^*
UlP 4 i^n t$f op at T i teet'^^"^^**^
Gr Sit for ftiQfii|Qnn9 babv snjoni ex
ai9<va»riritki0VMi^ampfifier FuM 2
Vi rms DUfpiUl runs on 6 to IS VOllS.
use* ft-4 5 orwn speaker
COfTiptvie ii< SN^ S5-95
TONE DECODER ^
A iLOitipkiie £w* _i
tah« 4i«c4di4 on ^ J0^2>
* »r>13l»e PC b<Mrd ^^fU^
l^eiitiirei 400-5000 X*^
Hjr adju^ebte rimge vm
?0 lum pot. voltsge regulatton 5^7
IC Usehil lor touch-lane decoding
tone tsurst delectian FSK etc Can
Also be uied as ^ stable tonf^ en-
oodwr Runfi on 5 ic 1 ? voltB
Cfimplel^Hit TD ] IS. 95
COian ORGAN MUSIC lIGIfTS
Sf.f> TTiutic come aHive* 3 drtfererrt
iiqFT.1^ rinriksf (wiiH music Ofve iigt^t
'ar \f**f% Qf^c lor tr>« mid-rsnge and
one lor Itve ntgns Eacli channel
ifidivjdua^ly f^djustabli?' and drives
uplQ 3CI0W Greai lor parties band
music nite ctuh^ ^nrf more
C?ifflpletekit ML-1 S7.SS
POWER SUPPLY KIT ^
lAted power &upp4y pr^- ''^r^W
wdei v4Mai:)Je 6 to tg ^"^-C^iy
voitt At ?00 ma and + SV at 1
Arnp EkCelieni load r^p^ulalmn.
oood lili€irifig and small size Less
franjitormers requires 6 3V ir' 1 A
' and 24 VCT
C complete itil. PS-3LT S6.SS
LED BLINKY KIT
AgiQ^i (iiiention yelter which all&r'
r^alflly Hushes 2 lumtao LEDs Use
lor name badge;;, buttons, vtutnm^
panet INjhts. anyihmgi fluns en 3 lo
15 wnlfs
CofTvplfflfrKil Bl-T J2.9S
WHISPER LIGHT KIT
An mtsrtating kit. smalli mike picks
up sounds and converts Ihem 10
light Thtj koyder the sound fhe
brighter Iho light; Goitiplfelely self-
contained, inciudeg mrke runs on
1 IQVAC, conlroif up tc 300 waits
ComprftH! N-t WL-1 «6.95
SIREN KIT
h'rtjduces upward and downward
^flil' char acleJ'istic ot n policB s^ren
&Wp«ahauctiooutpur runsonS'lE
volts u^i 3-45 Dhm speaker
rsfnsa^ alasircniss
BOX 4072, ROCHESTER, N,V, 14610
PHONE ORDERS CALL
{710)271-6487
FM MINI lUIIKE KIT
A super htgti pertorrrii^nce FM
M»feless rnike ktt* Trajisrukts a St&Pte
signal up la 3DCI yarPs with ^jiCftp-
lional audio Quatily by rneanf ol kls
t^uilt m etectret mike Kil mcludes
case mike on -oft awitcf^ dfilerkna
battery ar.d super mstf uCHOns T>ifi
IS ttie imest unii available
FM3iiit S12J5
¥ M-^ Iff tfEKd and tested 1 i J 5
CLOCK KITS
our Best SeMer
your Best Deal
Try your hand at tiuiipLng ihe tmctsl K>piiin<g
clocli cm itie market Its satin imistii an 0^291}
aturninum case looks great aiiyMrhi»h^ ^n^ie six 4"
L£D drgits provide a highly readable display Thi^ 1$ a
Cdrnpleje kit no entras needed and it only tak©^ 1 -2
hours ID assembte Your th'Oice of case colors
f^ilver Qoid bronze biacl<. bl je (spectlyl
Clock kit. 12 24 hour DC 5 $22.9i
Clock fA^Mh ip mm IP timet i2 ^4 hoPt,
I DC- 10 27,95
Alarm clocl*. 12 hour only.-DC-a 24. 9S
,12V DC car clock, DC 7 37,95
For wired and li&sied docks, add $1 D 00 to kit once
Hard to find PARTS
tllNEAR iCa
REGULATORS
301
1 35
i'BMG
11 25
324
i SO
723
50
380
125
309K
m
3ao-a
75
7a05
S5
555
45
?eLOS
2S
556
as
7905
1 25
H«
1 15
7B12
85
»7
r 25
^12
1 25
1458
SD
7at5
as
1W»<W
5G
TTLKSt
CHOS ICt
moo
%
4011
20
744?
e$
401^
35
M75
^^^■^
4{Mi
i B5
7*90
50
*&*9
«0
^4tMTI
t3S
4&1S
1 25
SPECIAL tQ%
53&I
1 75
11C90
T35Q
TIUW&<STOftS
1011*
t25
?N3#04lyi»
1CI 100
1511
200
zm^im \f(K
m 1 OD
5314
2»
NPN 30W Pwf
3 1 0€
53r5A0
295
IPMP 3CW P*f
3 100
?001
6 50
2N^&&
GO
AQS^*U
900
UJT ZN2^6 tvp«
3 2 00
7?oe
17 95
fET MPFl02t^pe
3 200
LEDt
UHf 2N5l79ivpe
3 300
Jumt>0 r«d
8 100
U^f'22& RF
11.95
Jumbo green
6 1 00
SOCKETS
Jurritx) yellow
6 r QO
Q pm
to 2 00
Mint red
6 t OD
14 pin
10 2 00
Micro red
@ t DO
16 pm
ia 2 00
BiPOlar
75
2A pin.
4 2 00
FEflBITf BEADS
26 pin
4 2 00
WiEh «nro spfiiCi
15 1 00
4Dpin
3 2 00
6 hole tjalun
5 too
-^
i
1
...
i
^^ - " ■"
TERMSi S^tisl^ctiQn g,u3rdnteed^ or monev
reiunded COO add SI 50 Mfnirnyrn order.
$6 00 Orders uf>der Sto 00 achJ $ ?^ Add
5% Pdr postage fn^urance har^diuip Over
s«a5 add T S\ NY resKSenti add f % tAx
298
»^R6
amiromcs, inc.
^H^%
OSCf^R
HEADQUARTERS
M
Quality VHF & UHF Kits
Af Affordable Prices
SSB TRANSMITTING
CONVERTERS
FEATURES:
• Linear Con verfcf for SSB, CW, FM, efc,
• A frgction of the price of o^her units
• 2W ^,e,p. output wilh 1 MW of drive
tiUs^ low power top on eKClfer or oHenuotor pod
• Eoiy to olt^ with buUt-in t«J poiiitii
frm^%mn€y Schemes Avoikifale^
MQD£L INPUTiMHi) OUT PUT (MHz)
2i-30
28-30
2 a- 30
2B*30
28-29
26-20
XV2- 1
XV2-2
XV2-3
XV2*4
XV2-S
XV2-6
50-52
2 20-222
222-224
144* U6
145-146
144-146
ONLY $59.95!
VHF Linear PAs
• Ue OS Liocor or CIob C PA'i • F« XV-2 Xmfg
Converters, T50 Excifefs^ or o^y 2W Exciter
LPA 2-15 Klf $59.95
• 15W out {lineor) or 20W (doss C) ■ Solid StoJe
T/R Switching • MijdeU for 6M, 2f/\, Or 220 M Hi
LPA 2-45 Kit S109. 95
• 45W out (f ifieor) or SOW (doss C)
• Models for 6M Of 2M
LPA B-45 Kit $89>95
For2M, 8-lOW in, 4SW our
T80 UHF POWER AMP
#8roQdband PA •No Tuning Retpirvd #€1055 C PA
•430-470 MHi
• 13-15WChit
•200 mW Drrvc
ModeP TBO-450
179.9 5
Wimd & Te^te<d
fffrfrfffffffffff
VHF RECEIVING famous hamtronicspreamps
^^■kiwcpTCpC let /ou hear the weak ones!
LET YOU RECEIVE OSCAR AND OTHER
EXCITING SIGNALS ON YOUR PRES-
ENT HF RECEfVERI
MODEL
C28
C50
CI 44
C145
CI 46
C110
C220
C222
Special
RF RANGE l-F RANGE
2e-'32MHz; t44-U8MH£
5&-52 28-30
144-146 28-30
T45-147 28-30
146-148 23-30
AirGroff 26-30
220-222 28-30
222-224 28-30
Inqufre About Other Ranges
ONLY $34.95
UHF RECEIVING
CONVERTERS
MODEL
C432-2
C432-4
C432-5
C432-7
C432-9
Special
RF RANGE l-F RANGE
432-434
432-436
435-437
427,25
439.25
2 8-30MHI
144- 146
28-30
61.25
61,25
Inquire About Other Ranges
ONLY $34.95
A9 Extruded AJutn Co$e wTth 8NC'i for
obove Convertcri (OptTonol) ,, , 512,95
VHF&UHF FM RECEIVERS
»NEW GENERATION RECEIVERS
*MORE SENSlTrVE *MORE SELECTIVE (70 or 100 dB)
♦COMMERCIAL G^DE DESIGN
♦EASY TO ALIGN WITH BUILT-IN TEST CKTS
♦ LOWER OVERALL COST THAN EVER BEFORE
R70 6-channel VKf R*c*J¥er Kit for 2M, 6M, lOM,
220MHZf or com'l bonds* ««.*«., ..,. $69.95
Optional xt^l filler For iOO d8 adj dion 10^00
R90 UHF Re^:elve^ Ki* for any 2 MHz segmenJ of
380-520 MH2 bond , SS9.95
Gf«jt for OSCAR, SSB, FM, ATV. Ov*r 10,000 in
use througho^ur fhe world on oN types of receivers.
P9 Kit $12.95
P14 Wired $24.95
Specify Bcind Wten OrdEnng
• Deluxe vhf model for opplicaflons where ipoce
permits • 1-1/2 x 3** •Models ovail to cover cwiy
4 MHz band in th« 26-230 MHz ftmge •H Vdc
• 2 sfoges •Ideal for OSCAR ^20 db goin
• 1>\q6c trornieni protection •Eo$jly hurublt
pa Kit $10.95
P16 WIrad $21,95
specify Bond
• MmiafurB vhf mod'el for tight space) " sixo Only
1/2x2-3/6 •Modeh dvoil ho cover any 4 MHi
bond in l^he rong* 20-230 MHz ^20 db gain •!2V
P15 Kit $18.95
P35 Wired $34.95
* C<iver$ ^^y 6 MHz bond \n
UHF range of 380*520 MHz
• 20 dB ^in '2 stages 'Low noise
NEW FM/CW EXCITER KITS
BUILD UP YOUR OWN GEAR FOR MODULAR
STATIONS, REPEATERS, a CONTROL LINKS
• Rcite<f for Contir»vou3 Duly • Ptofeniono}
Scunding Audio • ButH~Tn Testing AicH
1*- ,
tA i .■*
T50 Six CKannel, 2W Excrter for 2M, 6M, or 220
MHi (Specify bond). S49.95
T50U SiK Channel , 1W Exciter for 430-450 MHz
uhf opertvtiOit *.., ,,,,,,*, $49*95
►Ask For Free Catalog <
ITS EASY TO ORDER!
CALL OR WRITE MOW FOR FIEE
CATALOG 0« TO PLACE ORDERI
PHONE 716-392-9430. (Electfonfc
answering 5<!rwlc« eves & weekendt)
U« e c r e d 1 1 e a r d , c . o > d . , o h « c k ^ rrt « 6 V
IN CANADA, order from Cominunicotrofn Pfut, 3680
Cote Vertu; SihLourent, Quebec or pKone SM-'SiJ?*
7255. Add 38% to coyer dutyj tojtj ond gxchanme.
Note New Address and Phone No.
ami romcs, inc.
65a MOUL RD • HILTOHf NY 14468
— Dealer Irx^iries Invited-^
1^ Rea^tar Service — see paga 3-23.
299
VARIABLE POWER SUPPLY KIT $11^
Continuously Variable from 2V to over 15V
Short -Circuit Proof
Typical Regulatron of 0,1%
Ele€tronic Current Limiting at 300mA
Very Low Output Ripple
Ftbergla^ PC Board Mounts All Componentl
Assemble in about One Hour
Makes a Great Bench or Lab Power Supply
Includes All Compofients except Case and Meters
FREE
ICof FET's WITH
SS a STO ORDERS.?
DATA SHEETS
WITH MANV ITEMS
ewoa
ZEUlJtSA
R£tTlFl£ltf
ADD $1.25 FOR POSTAGE/MANDLING
SPECIALS-THIS MONTH ONLY
IHIU
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Mill
vmsM
aHfliiMiln DJDdii BflV IHmA
BHhRiiwuni DlBde 91V ZBDmA
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P-Ch»*MFET k<iLfkiiMT ZMl^ituIwi
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Lew fibt CHFitni Qp Amp-Sta^r ntS
& Veir Fttiulnar TO 3
llif|uftibl«V4jll!ia4 R«tu<ilBr 3-31 V
2 Win Authln 4^UMHi Affl^lkCttf D IF
Ftim LriEhid Laap HIP
Ph«N«m VitllA|M Rigntttitr DtP
Dili 741 Citttip*«iu(i[t t}p Amip -DIP
1VZ4-|il tUlNE nAH^t1>j4 I If DIP
FEI')[«ri4(|p4pp lili« NE ^1&/_A7U'
4-Tnuiuinr Amvi^irHngtBH
FM I F Aiiip/L4MlirM«lKtir OIF
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IIEAJILV VDOP ^MICONDUCTOftS. UTSL CAPAaTOftS; tfC-SENO Z&d STAUS".
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OTH£R ADVA KITS:
LDfUC nOH KIT-^g^ aiKi C1«M, TTI- DTL, HTU, MTLh iMMIL «i4 wmm Wl cx
ptari P94vtrf ttHfgri 0tg pia feLAJ4||£ Om«,4<d^ f 1t« mA IW" SMlli
iEQ i^4eMr ■CiomiirwT* litT amtuiMt c*" »r*il dip kudL 4flLV VJI
PIKtTl PlIGtJLATED PCnVtn UjnFCr K4TI~5>ort^u[iuri pfisuf witti tfxKivrl curranl
limllriig Camnicl sizi: ai« VfulcMi dimlf Uaei of O.li. oukf dwn e^U 1v nwil fllKttBnle
projtai. ^»iiiAl« 1^ ftV t HOmA, 9V * HOmA, BV » BOfrnA, ^7V • tOCtmA liV #
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Thtit ^iv-[[>'iii«^b1v keti MicEudi itl eamplMlVlll, OHlMriiti durtHod InilrucrlHMii Mtri pIllKl
fllWgiB re tnarEli Pniir wpply kill »t mi Irvluilt 41* pr mqiiri. M(l 31,2^ pfn lih tor
pAltia*Md liindling.
rNUULHOWl PBEE DATA SHEEtl
ifOUf|T-r4l On Amp iiftfli
P ET*! <HMh n4rr ofikf of |IQ pr
04IQf R TOQAr-AU itai* ■ih^il ty
A{tit^-n n-»«nA- pvt^-taw
MirTi mn Full cataudo xfi
tnmir mmn Ir^n lhlt id PPlEf <M
«t H m Mm-TW Dual Op Afiv fw mm f 100
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la liivH
IO6
EtHEi 4Klti4 i>
MORE SPECIALS: 4i
ftCAIiaON : ISV 9 MtnA VtRTAG£ f^EGULATOfl IC. Vwt WV to
MM. IVWhn ■ FHM Hifhlv RagutatBd ? 15V Supply 1^ O^ AMP^i. «tiL
ftaqtikr^t Qririr unnlguUmfdl QC !t&-3DVI ntd I feiyv*» Ci(Mdtoft.
Wch Dnj, ^M«t and SchimMlict, S-pm mOIP
ftC413B OuMJ 741 LdM Npite Op AmprnDEP
UrtlSM fN\ Muliiplaji St«F»gi E>tm'[Hiu|iiot DIP
LM2111 FM IF Suinyitim [If Annp, tM., Umiterf DIP
INQZeS Hot Cjinlni t)JK>rln 0.4V 9 tmA 0,1n) DO-3G
ZENERS-^pacify VulUyM X2, 3,9, 4.3. 5.1, 6.B. B.7
9.1. 10. lit, T6. ie. IB, 20. 22, 24. 27, gr 33V [±10%]
11,26
to.9e
0.99
too
flOOmW 4/11.00
1 WHtt 3/S1.00
• MONEY BACK GUARANTEE
• ALL TESTED AlVfD GUARANTEED
ADVA
BOX 4181 6B. WOODSIDE, CA 94062
Tel. (415) 328^1500
ELECTRONICS
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♦super SPECIALS: ^
IN34 (IfltrrTiiinilutii Dioite 10/51
tNOli IQOV^IOniA Diqdi 20/$1
1^4001 SOV/t^ n«ciJliqr 1^/$1
1hl4l&1 3flV 1Ngi4 ?5/$li
SHT 60V ^jA arltlQH H(M: 4/S1
ZNZ222 NPN Trpniiitar 5/St
a^i2B07 P NP TriniiitDF 6/S1
;{M3DS5 PoMMf XtitoF IDA £0.7^
IN^aCM MI>N Amp/Sw i.1 1 00 fi/Sl
2N3a» m» Artip/Sw ^ 100 6^1
CPCCO rami! FET MAmp t&
F5A3&01MDlod«Ariey
MPFtOI 200MHr RF Amp
40873 iyiOSFETHF Amp
LM324a,jatl7410pAmp
LM37e Ppi Voll fi*fl mDlP
NES«aTimtrmD|F>
Ll¥l7732 3f7VR4flDlP
LJVI74'r CQinp Dp Amp inDIP
LM14S8 Diul 741 rn^lP
CA30U S Tram Arrvy DIP
nCAffi ^wr Xitiw 1A 3(m
RF391 RF P^HW Amp Tramiitav lO-ZSW # 3 JOMKl TO-J
.n A n^« with QircufU It I
3/St
SI. 76
.94
.55
.38
3.."S1
6/11
31/11
3/t1
NEW SPECIALS
LM318CN
LlVI3ieO
ilVI33gN
LM380N^e
NE567V
XR567CP
LM723CN
LM747CN
Ki|hS|)Beil Op Amp SOV/^smOtP
High Speed Op Amp gOV^s DIP
Quad Cdrnparator Single or Dual Supply
7iW Audio Power Amplifier 8 -22V
Tone Decoder (PLL) D.OTH; to 500kHz
Tone Decoder (PLL) OJtHztti 500 kHz
Preciston ValtAge Regulator 2-37 V DIP
Dual 741 Compensated Op Amp
SAD1024 Dual 512 Stage (t024} Audio Delav line
"Buclcet Brigade" AppL Data included
XR2206CP Function Generator with spplic. data
XR2242GP Long^Range Precision Timtf ^% to days
1 YEAR TIMER Kit 2 XR2242'$ ind Applic. Note
LM2901N Quad Comparatof +5V or 2 to 36VDC
4 Transistor Array /Dirlington
RF/IF Amplifier DC to 120IVIHZ
Dual Hiih Gain Op Amp mDIP
SPACER Kit ' 4 eB of 5 assorted size spacers
±15 VDLT Regulated Power Supply Kit-Easy assembly,
&mV regulation, IQOmA, fully protected.
Includes all components and hardware,
no PCB or ca$e-Add $L50 for shippins
$0.94
JO
J9
JO
J9
M
3/S1
2/$l
S13J5
4,40
1.50
3
CA3018A
CA3028A
R04558
SK20
!,25
3/S1
SLOO
$13J5
1N270
IN 823
1Ngi4
1N3Q44
1N3045
1N3071
2N2915
2N3819f\/T
2N4020
2N4445
2N5394E
2N6912
2N6Q2a
2NS44d
CP&40
Germanium Diode 80V 200mA
Temp Comp Reference
B,2V±5% 1 .005%/ C
SiNcon Diode 100V iQmA
100V Zener IW-Oetter than an 0B3
1T0V Zener IW-Better than an DB2/0C3
200V IDQmA Switching Diode 40ns
NPN Dual Trami^or 3m V Match jlOO
N Channel RF FET 10QMH^Amp
PNP Dual Transistor 5m V Match j250
N Channel FET 5;i Switch
Ultra Low Noise i FET Audio Amp
Dual J FET RF Dif Amp to 800MHz
Programmable Uniiunction Transistor
300 Volt ly-Channel J FET Amp/Sw
Broadband FET RF Amp 140dB
Dyn Range
E304 N-Cbannel RF FET 3.8dB NF @400MHz
MPSA1Z NPN Darlinglon Transistor ^20,000
TISfia N -Channel FET 400MHz RF Amp
RESISTOR Kit-150 pes %W, 20 most common values,
individually packaged, S to 20 pes each .
PC BOARD Mounting Kit-8 ea spacer, screw, nut
ind washer-32 pes total.
4/Sl
$0,60
25/$ 1
Jfi
M
$1.95
.35
5J0
3.S0
$1.25
2.30
.45
2.00
$4 JO
.50
.75
,60
$4.95
$1.00
SEND FOR ADVA'S NEW 1979 CATALOG
NEARLY 1000 SEMtCONDUCTORS, KITS, CAPACITORS, ETC-SEND 25^ STAMP.
t^A24
ELECTRONICS
BOX 4181 GS
WOODSIDE, CA 94062
Tel.(415) 328 1500
300
^ Real-Slate-of-the-Art
V^ TWO NEW AC#DC«BATTERY PORTABLE COUNTERS
OPTO-SOOO.IA 10Hz to 600 MHz — FREQUENCY COUNTER ACCESSORIES
• Precision TCXO time base 0.1 PPM Stability 17-40=C PROBES:
• Super Sensitivity with preamps in both Hl-Z & 50 Ohm inputs #P-100 50 Ohm IX $1 3 95
<10mV to 50MHz. 25 mV @ 1 50 MHz <50mV to 600MHz #p-ioi Lo-Pass". .... ... ....... . . . 1 6 95
• Auto Decimal Point • Aluminum Case • Socketed IC's #p-i02 Hl-Z, 2X 16.95
• Three oosltion attenuator: XI, X10, X100 {avoids false #aP' 8015 UHF Counter Preamp 20 MHz to
counting) 600 MHz 1 5-50 DB Gain
#OPTO-8000. 1 A Factory Assembled $329.95 (Not Shown) . . $49.95/Kit $39.95
#OPTO-8000.1 AK Kit Form $27995 ^^ ^g^ Antenna
#NI-CAD-80 NI-CAD Battery Pack $ 19.95 Rubber Duck RF Pick-up 450 MHz ... $12.50
OPT0-70CO 10 Hz to 600 MHz MINIATURE COUNTER #D-146 Same as above
• XTAL fTCXO) Time Base ±.08PPM/ C 146.5MHz $12.50
• Aluminum Case • Hl-Z & 50 Ohm inputs #RA-BNC Right-Angle BNC Adapter for
• 1 Sec. & 1/10 Sec. Gate times • Auto Dec. R. above Antenna 2.95
• Built-in Prescaler and Preamps Standard
#OPTO-7000 Factory Assembled - 1 Year-Guar . .$139.95
#OPTO-7000K Kit Form 99.95
#AC-70 AC Power Pack 4.95
#NI-CAD-70 NI-CAD Battery Pack 1 9.95
#TCXO-70 Precision TCXO Time Base
<0.1 PPM. 17-40C 79.95
OOODDOOO
ai>T0-i90ii
ORDER FACTORY DIRECT — PHONE OR MAIL
TERMS: Orders to US. and Carrada. add 5% to maximum of S 10.00 per order
Ibf shipping, handling and fnsurance. To all olhec countries, add 10% of total of-
def. Rorida res stents add 4% state tax. CO.D, fee: $i 00, Personal checks must
baiom mere hand se is shipped
$^Qi
OPTOELECTRONICS, INC
5821 NE 14 Avenue
Fl. Lauderdale, FL 33334
Phones: (305) 771-2050 771-2051
Phone ofdef s accepted
1^ Rwad^r Service— S99 pAge 32 J.
301
•«•••*•«••••••••••••••••••••••«•••*#••*«•*••••«••*••••••
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KTT FEATURES:
16K E-PROM CARD
IMAG1HE HAVING 16K OF SOFTWARE ON LINE AT ALL TIME!
S-100 llmsal/Altalrl Buss Compatible!
1. OoufaJE sided PC board with solder
mask and silk scieen and gold plated
contact fingers.
2. Selecul3l0 wait states.
3. AH address lines & data lines buf-
fered!
4. All sockets included.
5. On card regulators.
KST I INCLUDES ALL PARTS AND
SOCKETS (except 27Q3'5). Add $25. far
assembled and tested.
S|>t)%7*9o
SPECIAL OFFER:
Our 27QB's (4&0NS) are
when purDhased witb above lit.
$8.95
NEW PRODUCTS FOR 1979
New Products are Scheduled for delivery during January 1 979. Some may be available sooner. CalL
• ••■**
• #•••-
• ••+•*
• ••••'
• •••*-
^ J • ••
Z-80 CPU KIT
$129
For S-100 Buss. Features Jump
on Reset capability. We feet this
board has the most correct
PSYNC signal for trouble free
operation. Complete kit. More
data on request, (for 4MHZ
ADD $10)
16K STATIC RAM KIT
For SS-50 (S.W. TECH. 6800)
Buss. Fully static uses 2114
RAM^s, 450 N,S. At last, a quality
RAM board forthis popular Buss
at an affordable price. Complete
kit, Additional Data on request.
DUAL DENSITY FLOPPY DISC
CONTROLLER
For S-100 Buss. Reliability and
Quality assured. Uses WD1791
Controller Chip. For 5V^ or 8 inch
drives. Full IBM and S-100
compatible. Perfect for use with
CP/M, Special P.L.L. design for
maximum reliability. Assembled &
Tested - $219 Additional Data
^ on Request.
COMPUTER PARTS
Z-80 -$19.95 8080A- $6.95
Z-80A - 24.95 821 2 - 2.25
CPWI is a Tradetnark of Digital Research of Califorriid.
ALARM CLOCK CHIP
N.S MM5375AA Six Digits.
With fuil Data. New!
$2.49 each
MOTOROLA 7805R VOLTAGE REGULATOR
Same as standard 7805 except 750 MA output
TO^220. 5VDC output.
44c each or 10 for $3 .95
FULL WAVE BRIDGE
4 AMP. 200 PIV.
BB^ 10 FOR $5.75
NOT ASSOCIATHD WITH DIGITAL
RESEARCH OF CALIFORNIA. THE
SUPPLIERS OF CPM SOFTWARE.
450 NS! 2708 EPROMS
Now full speed! Prime new units from a major U.S. Mfg. 450 N,S.
Access time. 1 K. x 8, Eqiiiv. to 4-1 702 A's in one package.
75 ea.
PRICE CUT
$9
95
«295™
COMPLETE KIT
1 6K STATIC RAM KIT
ASSEMBLED & TESTED
ADD $30
OUR LATEST COMPUTEI^ KIT!
FULLY S-100 COMPATIBLE!
FULLY STATIC, AT OVNAMIC PRICES1
?
WHY THE 2114 RAM CHIP?
We feet the 21 14 will be ihe nexlindListry
standard RAM chip (Eike th$ S102 was).
Thf& means price, availabiiily. and
ualjty wiM ell be good' Next, the 2114 is
ULLY STATIC! We feel this is tiie ONLY
way lo go on llie S-100 0uss! W$'v& all
heard the HORROR stones about sonnie
Dynamic Ram Boards having trouWe
with DMA and FLOPPY DISC DRIVeS,
Who needs these kinds of problems'''
And finally, even among ot hex 4K Stat Jc
RAM's the 2114 stands out* Not all 4K
static Rams are created equaM Some o*
the olJief 4K's have clocked chip enable
lines and variou-s timing windows juit a*
crlllciil as tSynamic RAM's Some of ouf
competitor's 16K tioards use these
"tricky"' devrces. But not ua? The 2i14 is
the ONLY iOQECSi choice for a trouble-
free, straightforward deigign
^ w<>IL-ja^.«rti^ Mm^^m^
a^^B*""
iiiiiiiigiiiiiiin
.:; :&«iMttii .mam
ijp-.'
;■■!:
■ --
■
'ViU ir npTTIUIH IlilTIUJ^ ... ,
$33.00
(450 HS)
BLANK PC BOARD WITH DOCUMENTATION
SUPPORT IC S 4 CAPS - $19.95
LOW PROFILE SOCKET SET - $12.00
211 4'S 4K RAM'S - 8 FOR $69.95
SUPER SPECIAL: BUY 32 Kl I S (512 KILOBYTES) (8-64K BANKS) for ^8,995
KIT FEATURES
1. Addressable as tour separate 4K
Slocks.
2. ON BOARD BANK SEtECT Circuitry
(Cromemco Standard!) Allows up to
S12K on iine^
3. Uses 2114 (450NSI 4K Stattc Rams.
4. OM BOARD SELECTABLE WAIT
STATES
5. DoubJe sided PC Board, with solder
mask and sHk screened iayout. Gotd
plated corttact fiRgers
6. All address and data lin#s fully
buffered
7. Kit includes AIL parts and sockets.
S. PHANTOM IS jumpered to PIN 67.
9, LOW POWER: under 2flmpsTYP|CAL
from the +fl Volt Buss,
10. Blank PC Board can be populated as
any multiple of 4K
P0
NATIONAL SEMICONDUCTOR
JUMBO CLOCK MODULE
IVlALOOeA
BRAND hJEW!
mm»?:
ASSEMBLED! NOT A KtTi
21J1.U VEHSlONl
We h^vca Itmil^d number ol thie ?4 HH flt^l
l\\T\t' f^i\\'jT\ pi IfiFS nMiHJi,:l4' irr llijCi;
#MAiaoeD-SB.S5
PERFECT FOn USE
WITH A TlMe&ASE^
FEATUReft.
* FCUR JUMBO >HNi,:ri LED CIS PLAYS
* 12 HP REAL time: format
♦■•S4HR ALARM SIGNAL OUTPUT
* SD Ofl eO Hz OPERATION
* LED BHICHINSSS COnTRO'.
* POWER FAtlURE IMQICATOR
» S^.£6P £ SNOOZE HWERS
* OlReCt L£D DRiVt I LOW RFIS
iAC;(FMRS1.g5J 'COWES WITH FULL DATA
COMPARE AT UP TO TWICE
OUR PRICEl
W^ANUFACTyRER•S CL05E0UT1
Digital Research Corporation
{QP TEXAS)
^ P. O. BOX 401247 /GARLAND, TEXAS 75040/(214) 271-2461
SALE!
1N4148 DIODES. SILICON,
Same as 1N914. New,
factory prime, Full Leads.
100 FOR $2
1000 FOR $17.50
New! REAL TIME
Computer Clock Chip
N.S. MM531 3, Features
BOTH 7 segment and
BCD outputs. 28 Pin
DIP^ $435 With Data
16K DYNAMIC RAM CHIP
16KX1 BU3 IfiPtn Package. Sarnfii as Mustek 411 5-4. ?5J0NSa<!<;es.s itONScyde
tune. Oyr best price yet <oi ih^g stale ot ihe an RAM 32K and 6h4K RAM hoards
using this chip aKC ired<ti'ty ^^djbbr^ Th^se ^r^ new Fully gui^rdnl?^ ijevjces by a
rnaior mig VEHV LIMITED STOCK!
$14.95 each
8 FOR $89.95
TERMS: Add 30<t postage, ^e pay balance. Orders under
$15 add 75^ handling. No C.O.D, We accept Visa, Master-
charge, and American Express cards. Tex. Res. add 5% Tax.
Forejgn orders (except Canada) add 20% P & H. 90 Day
Money Back Guarantee on all items. J
■ «•*•*•*
#•«■***#»«*««*
«•«•#••«•••«••
«•#•••••«•••••
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• • • « #
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* • • « 4 •
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ROTRON FANS
#CT3A52 - CENTAUR. 4%''
SQUARE 220 VAC 60 HZ. WILL
WORK ON 117 VAC REMOVED
FROM NEW EQUIPMENT.
LIMITED STOCK *_«-
3 EACH
* * •
• * «
*•«•«*<•■•••
»•«•«•«««•«
• V • a
• • •
■ « *
? t J : ?;
1N4148 DIODE SALE!
FULL LEADS! BRAND NEW!
COMPUTER MFG. SURPLUS
PRECISION OPTICS
31.5 POWER f;2.8
THREADED MOUNT
$195
I each
ORIG. COST $16
These were used in MICRO-
FILM equipment. Perfect for
experiments.
100 FOR $2
1000 FOR $17.50
PC BOARD
EDGE CONNECTORS
*-■*-¥-
r,f~%.^.-—-^',- - ■*=" 'v-
7SC 4 FOR $2.50
36 Pin. Gold Plated Solder Tail. .156 IN. Spacing,
Double Rows of 18 Pins. For standard thickness
(.062) PC Boards Major U.S. MIg. PRODUCTION
QUANTITIES AVAILABLE.
SUPER BRUTE RECTIFIER
(limited stock)
160 Amps 100 PIV
Stud mount by Motorola
$6.95 ea. or 4/$25.
FERRITE BEADS
8 FOR M°o
% inch long. For RF cir-
cuits. Make inductors
or use forRFI suppres-
sion.
FULL WAVE
BRIDGE
25 amp
50 PIV
$1.25
MALLORY ELECTROLYTIC
FILTER CAPACITOR
1500 MFD. 16WVDC.
Radial Leads. Factory Fresh!
3 FOR $1 10 FOR
S2.95
Perfect for Power Supplies!
Small Size: VM x % Inches.
1
12VDC Relay by CDE.
SPOT. Coil is 280 ohm.
Small Size. $1.29
DC PANEL
METER
TOP QUALITY.
SMALL SIZE.
500 MA. F.S.
$099
Z-80 PROGRAMMING MANUAL
By MOSTEK. or 2ILOG. The most detailed
explanation ever on the working of the Z-80 CPU
CHIPS, At least one full page on each of the 158
Z-80 instructions. A MUST reference manual for
any user of the Z-80, 300 pages. Just off the
press. $12.95
14
16
18
22
28
PINS
PINS
PINS
PINS
PINS
IC SOCKETS
LOW PROFILE
LOW PROFILE
LOW PROFILE
LOW PROFILE
LOW PROFILE
6/$1
5/$1
4/$1
3/$1
3/$1
OPCOA LED READOUT
SLA-1. Common Anode.
.33 inch character size.
The original high efficien-
cy LED display, 75C ea.
4 FOR $2.50
WESTERN DIGITAL UART
TR1602A. PIN FOR PIN SUB FOR
AY5-1013 mND TMS6011.
FOR SERIAL I/O
»2
99
EACH
SURPLUS SPECIAL
HEAVY DUTY DC MOTOR
1.5 to SVDC High Torque. Heavy
duty magnet. Reversible, Do not
confuse with cheap toy motors sold
by others. High RPM.
75«P EA.
3 FOR «2
TIP-30 POWER TRANSISTOR
Prime new/ units. TO-220 Case.
PNP silicon. VCEO-40 IC-1AMP.
FT - 3 MHZ. 30 WATTS.
3 FOR «1
SURPLUS SPECIAL!
COLOR BURST CRYSTAL
3.579545 MHZ. New Units.
Used in time bases, etc.
.0?^^
^'
990
EA.
ELECTROLYTIC CAP SPECIAL
Factory Fresh! Small Size.
100 MFD 16 WVDC
6 FOR M
30 FOR *3»5
FAIRCHILD RED LED LAMPS
#FLV5057 Medium Si^e, Clear Case. RED EMITTING, These are not
retested oH-spec units as sold by some of our competition. Theseare
factory prime* first quality, new units.
10 FOR sr«
50 FOR ^4^^
WE BOUGHT 250,000 PCS." |
^D20
Digital Research Corporation
** (OF TEXASl •
P. O. BOX 40T247 • GARLAND. TEXAS 75040 • (214) 271 2461
FAIRCHILD PNP
"SUPER TRANSISTOR"
2N4402. TO-92 Plastic. Silicon PNP
Driver. High Current. VCEO-40 HFE-50
to150at150MA. FT-150MHZ. Asuper
"BEEFED— UP" Version of the 2N3906.
8 FOR $1
VOLTAGE SUPPRESSORS
By Midwest, #6705010. Silicon Carbide Varistors. These units grab
voltage transients, spikes, surges, etc. For use on AC or DC in the
range of 12 to 28 Volts Small Size; .5 Inch Disc with radial leads. For
use across Iransformer secondaries, relays, etc More rugged and
reliable than silicon devices. Rated at 30 WATT-SEC. ,25 WATT
CONT. Perfect for use on AC operated clocks and instruments.
(THE GLITCH SNITCH J
SPECIAL PURCHASE: 3 FOR $1
TERMS: AcJd 3QC postage, we pay balar^ce Orders under S^5 add 75e
handling No COD We accept Visa. Mas(efChafge and A men can
Express cards Te* Res add 5% Tax Foreign orders (except Canada)
add 20% P & H SO Day Money Back Guarantee on all items
• fl • • *
« • • « •
• • * • «
• • * « *
• * « • •
« * • « •
• ■ • • *
• * • » «
• * • 9 •
• • • • •
* w * *
* m
• * * *
• •
S-100 BUSS MEMORIES
THE BIG OIVE:
32K ECONORAM y^
unkit only $599!
Here is dense, low power static memory.
Guaranteed 4 MHz operation. Configured as 3 indi-
vidually addressable and protectable blocks (one 16K
and two 8K]. At last . . . you can fill your computer's
memory without overstuffing your motherboard, or
emptying your wallet.
MORE PRODUCTS . . .
TRS-80 CONVERSION
fQT $159
Expand the TRS-80 mainframe from 4K to 16K, or
use with the memory expansion module; our detailed
instructions describe both conversion processes.
Includes all parts necessary for conversion, and is
backed up by our standard 1 year limited warranty.
Also suitable for memory expansion in APPLE com-
puters, 3 kits/$45Q.
ECONORAMS COME IN THREE FORMS . . .
Most of our boards are available as "unkits" [sockets and bypass caps pre-
soldered in place for easy assembly); assembled and tested; or qualified under our
Certified Systems Components fCSC) program. CSC boards are burned in for 200
hours, serial numbered, and guaranteed to run at 4 MHz over the full temperature
range. We exchange CSC boards if any defect occura within 1 year of invoice date.
AND ALL OFFER THE FOLLOWING FEATURES:!
Fully static design, buffered lines, tri-state outputs, dip switch address selection
and deselection, write strobe selection switch for S-100 boards, complete socketing,
guaranteed current and speed specs, a 1 year limited warranty, and more.
8K ECONORAM IF^
$139 unkit, $159 assm
Our least costly way to add static menaory to S-100 machines*
Configured as two mdepeiident 4K blocks, with separate protc?ct
for eacti blocJc and vector interrupt provision if you try to write
in protected memory. Handles DMA, Less than 1500 mA current
consumption,
M
12K ECONORAM Vr
$235 unkit, $270 assm
Same basic features as our S-100 memories, but designed
specifically for the Heath H8. Configured as two blocks with
switch selected protect. Also includes hardware and edge con-
nector required to mate mechanically with the H8.
16K ECONORAM IV
TM
$279 unkit, $314 assm, $414 CSC I A SUPERB CLOCK: $16.50!
Static memory configured as 4 independent hflocks (two 6K
and two 4K). Write protect for each block; use with or without
phantom line; provision for two qualifiers; runs DMS at 2 or 4
MHz; draws less than 2500 mA (1800 mA typical).
TM
24K ECONORAM VH
$445 unkit, $485 assm, $605 CSC
Manual write [protection for 4K blocks, use with or without
phantom line, runs DMA at 2 or 4 MHz. Guaranteed undnr 2000
mA current [typically 1500 mA). Now you can hav^e full static
storage at less than the cost of dynamic equivalents,
We think the MA1003 dock module is the best clock module
going . , . add three time-setting switches, a source of power,
andyouYeupand running. Includes crystal controlled timebase
for 12V DC operation — ideal for car, van, truck, boat, field
day, or any other mobile application. Large [0-3"] blue-green
flourescent readouts are visible under ambient light conditions
that would wash out LEDs. Also, there arc special options for
car applications (for example, turning on headlights dims the
display slightly for night viewing). All in all, whether you need
one for yourself or want to present someone with a neat gift,
this is an excellent choice, Includes applications data,
3 modiiJes/S46.
FREE FLYIS: 40 pages packed
wttli the latest in electTonlc goodies.
Send us your name and address, well
take care of the rest. For first class
delivery enclose 41^
BILL GODBOUT ELECTRONICS
BOX 2355, OAKLAND AIRPORT. CA 946U
TERMS: Add Si hendlitig to orders Lindar $15,
Allow up 5% shipping [excflsa refundedK We
prefer street address for LFPS delivery.
VTSA* /Master charge* cali our 24 hr. ordfir
desk fli (415J Sfia-Oesa CODs OK with street
address. Califurnijiiis add sales tax.
^^G4
304
]
01
ELECTRONICS
Kits
Regulated 1^0 wer Supply
* U9« LM 309K
« Heat smk pTovrded
« PC tHWrd conslciiciJon
* Provides a sdid 1 amp (^^
5V
* iTicludes com;iontnts.
hardware and insrryciians
JE200 $14.95
Function Generator Kit
m PfovidflS 3 basic mave-
larms, sine, rnangle A
square ivave
• Frfquen^ nn^t Trofli ! Hz
* Output imphtu^e from
» ll$«s a ISV supply EH^ a -
6V spb! supply
» Indodte cfip. PC. toiftf.
C9fnpdrt«nts and ifmntc-
trons.
JE2206d $19.95
NT
Digital Stopwatch Kit
_Wwl«
■H
• "•'
f
*
J^S
J
- Use mem\ 72m Chip
. Pkled tfinj double -sdded
PC. Boaid
- LED display (mj)
. Hmes to 59 min 59. 5$ stc wth
mo res*i
- Quam crystal controlled
» Thret smpwaicties in one
stngfe event, spin icummjl^tive^
and Eaytor isequeflM timiniy)
* Uses 3 penfite t^ftefiis
*Sizt ^5*2 tS^jt 90-
JE900 $39.95
MICROPROCESSOR COMPONENTS
s.-n
nzsa
cpy
Pfionff Inle^ujal Coranal
Bj-DiactiDma' ^us [>Ti*nr
SjHSn OantFifflBf i*9ui Qmvr
Sfil03i QtmlrdUlt'
»v?s to™ I* jUStftrj
Pan ^B^ t^(?n]
t 9%
3.49
• «
HllitnOPPIDKSS&B MJHiUALI
M-zM iiwMiiiuii trsp
iOH^-
O^ plBVMrflHiiiriH to SI
4-Dlglt Clock Kit
^•1011 imsnD
**tv^^
Hie Sf itdtrir PIMR3S.
,^ myftimeter fofonly $59
H
«W#^«JlBI
t#ll4«ltl
TTw ^"iL-jii PEl^LlS vhiiuin ^hA Jt'si
gLit fll t 'itj |:ei|] mjci y«tj hu jfil
II. Miflf^Jril I Mill
■ ,bpf 11111
EflfLiitifii lub ifL^iriikytit hiM»i|iMi»r (f¥
,357" ht, red display
« Sequenlial flashing colon
* 12 or £4 hour operaiioi
* EKlrtid&d alumimiin ca^« [blafih;)"
* Pressure switches far Hours, rninoies and hold rnode^
* Includes all companants. cas« and well translarmer
* Sue: 3-1/^x1 '3/4-' X 1-1/4"
JE730
$14,95
6-Digit
Clock
» Bnghl 300 ht conirtion cathode display
. Uses MWS314 dock aip
* Stttiches Toi^ hours, minutes and hold lunctioiis
w Hours easily viewable to 20 r«et
• Siniulat9{} vralnul case
* US VAC op&^ation
* 1? or ?4 hmir opefal^on
• InduOas all compoTiefits. case and wall iraitsformer
• Size 6-3i4-jt 3-1/8' « 1-3/4-
JE701 $19.95
Jumbo
Clock
Kit
• Four . 630" H and two 3Q(rht common laodei
. Uses MM^14 dodc dup
. Switches fof hours. nMfuilfs and hold tlMCbons
. Hdut^ easily ^iwiiBte to 30 feet
. SimifigM wainur ci$e
. 1)5 VAC opemion
. i3ar?4tioufOpvallon
* Includes all compomsnts. case ami wall transformer
Size: 6-3/4- 31 3-1 /r I l-3;4'
JE747 $29-95
XMAS SPECIAL - Get
PLUS the 117 volt AC
Padded carrying case
(Retail value S73.05)
your PDM-35
Adapter and
for only
$64.50
S4€PREClSiQlV
fttoder ZBDO
$99 95
CCiTirir • I :r ■
a^'OlQit Porta bla DMM
* y ivyh HtJ Um\fft
-■ QiiM^i ui AC opd'HrtKl
« Atjio Z«rii«tit]
* \rm Wl {] • IWiti n^yHSn
* f'J qieg incul irnpenilenLi
AEVMipe U-IDtKlV
FfbI AsiCHinsE ^"ICIO HZ
^?iSistoiK* Q-lDmetfaPirti
Slit ^ J . I * ti
AC Adapter IC'2B $9.00
Retl^irseajilt
MtniT I tiiiHOV
%<.iiipt«VM4 i*fedipw id^ 1 j'^naMt
EKVCvimH 44 aaapk^
|lui||i' I M ^a AW m.\
Ilii4iiimi tli niimiii.|i
fUAtf N^ III JuM>l
i^lSMffk H^HtMin*. I }^ T < fliuli.
AtM> p»MMlH 1 tHMIMtl'laik MAiffl
tHrMMtaMr (( in I I ni I w i a
MrliJhiil'Hii
>l|i>liil \\ riJipi4 llbUMV HM Hml.
'bdirkitiiMtnilAiJ lim[nrni
i^ulirmi'lM^i
IMIaiHi M. itJi|iiii liirlir ^
Aillli'l, I'VLTi 1^ IvirflfihlrJ
100 MHz
8-Diglt
Counter
lii:iti«i. 1 iQ 1)1 "S'ityi ttm
c>i4'tl*i '^V wirti luid
iNghMr iHiptar iihH ii|«r[V|i
7 M QV |M«lr lupfiry
•W"" «1 34.95
«»iriMPii«, i<4Enii4| «o»<i»fiii9n
• &'|J:l>£llijilar
t Cr^fill -{«n|Ji,illiii: i i'-:
• ^\Mi AutuintliC
mi-uyiuifiia
tser
H IddHUU
ACCESSOI^ieS FOR MAX 100:
MDbllt OHtpr Dlwunir
■ -,..*<■' ^fvncud^am Mpiii m — cu ui iSi
[;jut|«f>tlimlnKtir
.tf 1 lii ¥ U H*M in — CM MM
i€
Mini -Max 6 DIqU SOUm Frequency counter
rtne« (It 1W Hi a SO UHr
fBly WtelgiM, Wll%. i*gpi. BIQOW- inptf iTi^ »i»tfMe n^ fiHiKifl. ^_
-q Hep Htm: dipmil p^r^Mf'M'^e'^ IW* « ***! nt lfn« <i lunwl m
sjijtt ia w^Ht. mnmibo^ptflliQiOB.
MINI-MAX $89.95
— Ori^tat
Pati No.
VM-CS
lut^Aca
Aj^cessortes For Mini -Mai
Description
Attt
Price
»a»
3JS
196
Ib.m U.yj\im\im Order - U.l Fundi Ofity
C«Jjfenii4 Rfii^ms - Add &% Sahi To
Sp«c Shit a - 25*
The tncredjtile
"Pmnnywhtsile 103*
$139.95
KU OflJy
ameco
ELECTRONICS
Jlf>iyi 0/^£^/? ELECTROMCS - WORLDWtDE
FHONE
ORDERS
VfELCOME
(41i) 5924097
1QZ1 HOWARD AV£«tUE,SAfl CARLOS. CA 94^70
Advertised Prices Good Thru December
*^Ji
WMMtv mMpn Bid tannnU Itf WtSftwne tummifiji j[)d DHVMHHMin ««
IlinKflffi Etn ItMi' . , 4.^__i_.i
J49QHBQhJaM Kcpii.
(wr^uMi
TRS-8Q 16K Cofiversion Kit
Expand your 4K TRS-SQ System lo 16K. Kil
OKTies complete wtt)i;
* 8 eacn lfPD416 f16K Dynamic Ranis)
' Documentation for conversion
TRS-16K $115.00
Special Otfef - Order Doth your TRS-16K ami me
S^p R MOD LI Interlace kit logetner f retail value
S 144,95) fof only Sl3f -95
COMPUTER CASSEHES
OUAtlTYC'lSCASSm^S
• piastk: case iiiauDei
12 CASSETTt CAPACTTY
. ADDfnONAL CASSETTES
WAIUIBLE #C-15-S2.S0 Bi
1*^* J UAo "0
'^>-n ?r--=:. i $14.95
SUP 'R' MOD II
UHF Channel 3a TV Inlertace Unit Kit
*Wide Band B/W or Cdar Sys(frm
* Converts TV to V^deo OisDiav fnr
iTOrtie computers, CCTV camBrj.
AppEe II, works wiTli Cromeco Du-
ikr, SQL-2C1, IRS -BO. Chdltangirr.
etc.
^ MOO II ts pretune^ to Channef 33
* Includes coaxial caDie and antenna
transfcnriBT
MOD II
$29.95 Kit
Custom Cables & Jumpers
Part No,
D;B25P-^P
□S25P-4^S
Da25S-4'S
0J1M
DJ16-1
0J24-1
DB 25 Series Cables
CabJe Lengtii
4 F]
4Ft
An
Dip Jumpers
Connectors Prifja
2-DP?5P STS 9S ca
1-DPZ5P.I1-35S STSSSea
?-DF35P S17 9& ei.
1 tt.
1 tt,
1 ft
1 tt
t fi
1 tt
1 14 Piti
1-16 Pin
l-^-lPin
2-14 Bn
2-24 Pm
SI 59 «a
1 TOfli
3 79 m
4gi5u
i4ir CuUDTTi C«b1» i Jvinpn:. S«t JAMEOQ 1171 CitllDl for FriEiffH
CONNECTORS
25 Pin-D Suhminialure
Dd^^hat p«dM«d» PLUG S2 ^
DiZ5£ SOCKET 3^
OBSI^TBI cable Cover for DB25 P Of S 175
63-Key Unencoded Keyboard
"■^^ B a &3-*£r. ^-ir^j^
wrtn SPST fcev5,
ytijttvbdtii^tMiif FCtasil. Aim^miiflidpttstic T3
1 *' tasg ails fWBtip^iafen msTDQi $2§ QS^eacfi
Hexadecimal
UnencDded
Keypad
19-kev pad indudes 1-10 iteys,
ABCOEF and 2 ootion^ bi^s ^0 i
$^ H&adet Service^see p^gm 323.
305
DIODES/ZENERS
SOCKETS/BRIDGES
TRANSISTORS, LEDS, etc.
1N914
lOOy^
lOmA .06
8-pin pcb .20 ww .35
2N2222
NPN (2N2222 Plastic. 10)
,15
TN4005
1 N4007
600v
lOOOv
1 A .08
lA .15
14-pin pcb .20 ww .40 '
16-pin pcb .20 ww .40
2N2907
2N3906
2N3904
PIMP
PNP (Plastic - Unmarked)
NPN {Plaitic- Unmarked*
,15
,10
JO
TN4148
75v
1C
)mA .05
18-pin pcb .25 ww J5
2N3054
WPN
.35
1N4733
5.1v
1 W
Zener .25
22-pin pcb .35 ww .95
2N3055
NPIM 15A 60v
.50
1N753A
1N758A
6,2v
lOv
500 mW Zener .25
,25
24-pin pcb .35 ww .95
28-pin pcb .45 ww T,26
T1P125
LED Gfesn,
D.L.747
PNP Oartington
Red, Clear, Yellow
7 seg 5/8" High com-antjde
.95
J5
1.95
IN 759 A
I2u
.25
40-pin pcb .50 ww 1.25
MAN72
7 seg com-snode ( Red)
1.25
TN5243
IN 5244 B
13v
14v
^' .25
" 25
Mo lex pms .01 To-3 Sockets ,25
MAN3610
MAN82A
7 seg com-af>ode (Orange J
7 seg com-anode ( Yellow J
1.25
1.25
1N5245B
15v
.25
2 Amp Bridge 100-prv .95
25 Amp Bridge 200'prv 1 .95
MAN74A
FN 0359
7 segcom-calhode (RedJ
7 seg corn-cathode (Red)
1.50
1.25
CMOS
- T T L ^
4000
.15
7400
.10
7473 .25
74176 .85
74H72
,35 ;
74S133
.40
4001
.15
7401
.15
7474 ,30
74180 ,55
74H101
,75
74S140
.55
4002
.20
7402
.15
7475 ,35
74181 2,25
74H103
,55
74S1 51
.30
4004
3.95
7403
J5
7476 .40
74182 JB
74H106
,95
74S1 53
.35
4006
.95
7404
.10
7480 .55
74190 1.25
74S157
,75
4007
.20
7405
,25
7481 ,75
74191 .95
74 LOO
.25
74S158
.30
4008
.75
7406
.25
7483 .75
74192 .75
74L02
.20
74S194
1.05
4009
.35
7407
,55
7485 .55
74193 .85
74L03
.25
74S25? (8123)
1.05
4010
.35
7408
.15
7486 .25
74194 .95
74L04
.30
4011
.20
7409
,15
7489 1 .05
74195 .95
74L10
,20
74LS00
.20
4012
.20
7410
J5
7490 .45
74196 .95
74L20
.35
74LS01
.20
4013
.40
7411
.25
7491 .70
74197 .96
74L30
.45
74LS02
.20
4014
.75
7412
.25
7492 .45
74 1 98 1 .45
74L47
1.95
74 LS04
.20
4015
.75
7413
.25
7493 .35
74221 1.00
74L51
.45
74LS05
.25
4016
.35
7414
.75
7494 .75
74367 .75
74L55
.65
74 LS08
.25
4017
.75
7416
.25
7495 .60
74L72
.45
74LS09
,25
4018
.75
7417
,40
7496 .80
751 08 A ,35
74L73
.40
74 LSI 0
.25
4019
.35
' 7420
.15
74100 K15
75491 .50
74L74
.45
74LSt1
.25
4020
.85
7426
,25
74107 .25
75492 .50
74L75
.55
74LS20
.20
4021
.75
7427
.26
74121 .35
74L93
.55
74LS21
.25
4022
.75
7430
.15
74122 .55
74 LI 23
.85
74LS22
.25
4023
.20 1
7432
,20
74123 -35
74H0O .15
74LS32
.25
4024
.75
7437
,20
74125 .45
74H01 .20
74S00
.35
74LS37
.25
4025
.20
7438
.20
74126 .35
74H04 .20
74S02
.35
74LS3S
.35
4026
1.95
7440
.20
74132 -75
74H05 .20
74S03
.25
74LS40
.30
4027
.35
7441
1J5
74141 .90
74H08 .35
74S04
,25
74LS42
.65
4028
.75
7442
.45
74150 .85
74H10 .35
74S05
.35
74LS51
.35
4030
.35
7443
.45
74151 .65
74H11 .25
74S08
.35
74LS74
.35
4033
1.50
7444
.45
74153 .75
74H15 -45
74S10
.35
74LS86
,35
4034
2.45
7445
.65
74154 .95
74H20 ,25
74S1 1
.35 1
74LS90
.55
4035
.75
7446
JO
74156 .70
74H21 .25
74S20
^5
74LS93
.55
4040
.75
7447
.70
74157 .65
74H22 .40
74S40
.26
74LS107
.40
4041
.69
7448
.50
74161 .55
74H30 .20
74S50
.20
74 LSI 23
1.00
4042
.65
7450
.25
74163 .85
74H40 .25
74S51
,25
74 LSI 51
.75
4043
.50
7451
.25
74164 .60
74H60 ,25
74S64
-15
74 LSI 53
.75
4044
.65
7453
.20
74165 1.10
74H51 .25
74S74
.35 '
74 LSI 57
.75
4046
1.25
7454
.25
74166 1.25
74H52 .15
74SI12
.60
74 LSI 64
1.00
4049
.45
7460
,40
74175 -80
74H53J .25
74S114
.65
74LS193
.95
4050
.45
7470
.46 1
74H55 ,20
74LS367
.75
4066
4069/74 C04
.55
.25
7472
.40
74LS368
.65
4071
.25
MCT2 .95 LINEARS, REGULATORS, etc.
4081
.30
8038 3.95
LM320T5 1.65
LM340K15
1.26
LM723
.40
4082
.30
LM201 .75
LM320T12 1,65
LM340K18
1,25
LM725N
2,50
MCI 4409 14,50 |
LM301 .45
LM320T15 1.65
LM340K24
1.25
LIVI739
1.50
MC 14419
4.85
LM308 (Mmi) .95
LM324N 1.25
78L05
.75
LM741 18^14) .25
4511
.95
LM309H .65
LM339 .75
78L12
.75
LIVI747
1.T0
74C1 5t
1.90
LM309K(340K-s^85
LM310 .85
LM311DfMlnl) .75
7805 (340X5) .96
LM340T12 ,95
LIVI340TI5 .95
78L15
78M05
LM373
.75
.75
2.95
LM 1 307
LIVI1458
LM3900
L25
.65
.50
9000 SERIES
9301 .85
95H03
1.10
LMSISfMlnl) 1.75
LIVl340Tt8 ,95
LM380(B-i4PiN).95
LIVI75451
.65
9309 .35
9601
.20
LM320K5(79O5)1,65
LIV1340T24 .96
LM709(a.X4PfNj.25
NE555
.35
9322 ,65
9602
.45
LIVI320K12 1.65
LM340K12 1.25
LM711
,45
NE556
NE565
m i ^^ .,^H° ^m. ,^m
,85
MICRO'S, RAMS. C
PU^S,
.95
E-PRC
74S188 3,00
17Q2A 4.50
)MS
8214
8224
8.95
3.25
INTECRATED CIRCUITS
UNLIMIT
lU *^'^
NE566
NE567
1.25
.95
MM5314 3.00
8228
6.00
7889 Clairemont Mesa Boulevard, San Diego, California 92111
MM531G 150
210M 1.45
8251
8255
8,50
3.50
(714) 278 4394 (Ca/if, ResJ
SPECIAL
DISCOUNTS
2102L-1 1.75
8T13
1,50
Al orders shipped prepaid No minimum
Total Order
Deduct
2114 9.50
TR1602B 3.95
8TZ3
8T24
1,50
2,00
Open accounts invited COD orders accepted $35 $99
^L ^^ ^^ ^. ^^ ^^ ^^
10%
TMS 4044- 9,35
8T97
1J0
Discounts available at OEM Quantities California Residents add 6% Sales Tax *'™ " ^300
15%
2107E
J4 4.95 1
AM IC's Prime/Guaranteed. AH orders shipped! same day received.
$301 -$t000
20%
8080 8,95
2708
9 50
8212 2.95
Z80P
10 8.6G
24 Hour Toll Free Phone 1 800-854^2211 American Expre^ / BankAitieriGard / Visa / MasterCharge
SniOCKTS « TUCHliS
WITH fOU* OKiBL SfMO ft{>DF Of
wun STATUS mo m.um b% of rou«
PKSEMT ORDfH AS A CtEDiT CEffTtFOTE fOU
UN ysf QH roui next E>I»EN
FVO SOCKETS
WITH FUKCKASE OF
OF TWESt lt'%
id
CHirSTlAS SPECIAL OF
OHDEITS NIAILED BEFORE
5^ OFF EFFECTfVE OH f^l
DECEMIEf? 25. J978
THE FmST MEMORY SPECIAL YOU WONT fOf^ET
21K-Z SlOiii <5" ^lai** M/?l»» 121/135**
21024 ISOiB B/10" 32/41" fi4/7«" I2I/N5"
21110 4S0i( 1/79^ Ifi/L4»«" 3Z/274** fr4/4|9*»
tomplett 123**
ComHiiK $49'^
11 CM- ntescALii chip
IH jnc $19«
SOUD STATE KELiT
•400 V it 3 AMPSvOL COttPATtSU
• HlCtO REED ACTUATTO TO HIPtWIZE
chahces or ic power spiuover into
CHEAPER BY THE 100
LiDI' (HP MIALRED) 100/8^5
LEDS^ (MtNllrCO) iaO/9.95
l£DSr aUHeOREO) 100/13 95
L£@S^ (OyAL COUIR) I(H3 59 00
LfMOQi (SQVI Min 100/ 4. n
1IHI4I (SWirCMtNG DIODE) ISO/ 3.»5
2114303 (NJftT^ L00/?lf5
flC3*? (PIWEPiPt LOW MOlSEl 100/ 9 §5
OPTO
/SOMTOflS
1. MCTZ % .79
2. MOCIOOO t .89
3. 4H-2S S .SS
4. CL1422
CUIRO PHOTO MODULI
(USE 4S VDLTKi VN#MBL£
RCaSTCR— 10 BtG Wll TO
40 OHM— WLilDM TD 0R€
RiTiO— OR use AS WRT
HI6M VOLTAGE OPTO
iSdLITDRl
•tlMA
S?17
I2J4
t?l«
W?i
1221
J-M
3410
^1
»■?
Mi3
34«4
WHS
5JS
3.75
Sf5
330
4.10
4?S
?.2S
1.25
945
2LS0
1075
20 50
20 50
22 50
12.50
12 50
4100
73QO
CfVt
tool
i03l
Oil
;4i9
3101
122^
2ID1 1
2101 2
2lDt4r4
21Q2 2
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I?S10
I^SIl
5IOtL3
710}
TVS40Ce
LTPMM
4?00A
nil 2D0ftS
MOO
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€420
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6150
il52
M«0
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?.20
7.»5
1.50
1.15
tliS
f.l5
13.75
REFLECTfVE
PHOTO COUPLERS
TIL'139 UM lin PHOTO
INCAftDESCEMT
INTO CDS €£U—
20 Hie OHM OFF
RtSl^rufCE ||«
MHHO POVEI AMPS
SINGLE
TDA2020 20 Wtn
SlIO^OH 20 Win
£11L30K 30 Win
SIK-54: 50 mil
11.95
tt0.50
tu.so
ItUS
SFMS3^ WiEli per cNnnK 16.95
STK435 ? Wilts PTC chinrtel Ji.95
STM37 11^ Wins p«r ^hinnfj $U.$S
STN439 15 *iib pcf ciMrivt 113 95
SIK44L'» mrtb. per clami ||6 55
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BEEN TAMPERED WITH WILL BE SHIPPED BACK IMMEDIATELY MODS 1, 2. 4 AND 5 SEND TRS80 MICROCOMPUTER ONLY MOD 3 SEND YOUR
TRS80 MrcaOCOMPUTER AND LEVEL 2 MOO 6 SEND TRS80 AND EXPANSION INTERFACE HCMML TURN AROUND HHE IS UH«R ID DAT1
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REICHERT SALES
^K25
1110 E. MRVn AVE.
W. COVINA, CA 91790
(213) 967-3846
■ J2B MHVIHUli OROER
•FREE UPS DELIVERY Dlt
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(MD£ A L£D DEVICES EXCLUDED)
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CHECIL
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k U.S. POSSESSIONS
ADD US i'S.b^. All
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IMN ELECTRONICS
1041 L Omm AVE.
WEST COVINA. CA
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WIZARD OF PARTS
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307
ASSOCIATED RADIO
8012 CONSER BOX 4327
OVERLAND PARK, KANSAS 66204
i^A5€
91 3-361 -5900
CALL US WITH YOUR REQUIREMENTS
AMERICA'S #1 Real Amateur Radio Store
TRADE
SELL
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SEND $1.00 FOR OUR CURRENT CATALOG OF
NEW AND RECONDITIONED EQUIPMENT.
#ALSO WE PERIODICALLY PUBLISH A LIST OF
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A BONANZA FOR THE EXPERIENCED OPERATOR.
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306
POL Y PAKS
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PREFOHMID DIIC CaPACITOHI, marfaad ¥tln**, ••■t'd |# MOBl"
CALCULATOR HiTIOAROS. 20 haym amf up. <■» 537 ij ' " ■ " ' ■
ALARM WAAHIHO iTtCKCRS, Tor wim-i^wt, 2-^4" ■ V' (• 113AI'
CAiCULATOfl tWITCttESwlPlT-H.D.. iitt'd. V^" ■«. (w 3BJ4J ---.-,*»*..* •.**.,,..-
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a LM340T-4V
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a UII340T-11V
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SWITCHES E ^
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Send for fl^w FREE
20 pfig« cvtAtog
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MODULES
•*t«»«t*«t<
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ai>-ac.OCO Hi, [t>m Ihan ftl <1In-
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includJngtlit btit birfAlnB^t
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p^ Peatler S€rvic«—te* page 323.
309
7294 N.W. 54 STREET
MIAMI, FLORIDA 33166
URPLUS
LECTRONICS
PHONE: (305)887-8228
TWX: 810-848-6085
WHOLESALE- RETAIL
PL 259's
QUALITY AMERICAN MADE
10/$5.00 100/$35.00
50/$40.00 100G/$300.00
E. F. Johnson Desk Top Microphone
Ceramic Element/High Imp
$20.00 ea
While They Last
IC SOCKETS
Cambion
Gold Plated Wire Wrap
14 pin .35 ea l0/$3.00
16 pin .38 ea
10/$3.30
SURPRISE PACKAGE
Resistors^ Caps, Semis, Pots,
Relays, etc. We guarantee it to be
$25,00 worth of matefiai. Every
package is different.
$5,00
TEXAS INSTRUMENT KEYBOARD
$1.95 ea,
5 for
$8.00
10 for
$13,95
Has 3 slide
switches— 28
different keys
keypads re-
movable by
removing 4
screws.
White Porcelain
Egg Insulator
IV2" X 1'^ 50$ ea
3 for $1.25
MINI TOGGLE SW
C&H
SPOT
SroOea B^SS.OO
Neon Panel Light
110 Vac Amber, w/ built in resistor
& wire leads— 3 for $1.50
WIRE WOUND
RESISTORS
.1 Ohm— 5W
.10 Ohm— 10 W
15(f each
12 Udc RELAY
SPST 35 Amp Contacts
Open Frame
Rugged, great for mobile usie
$4,50 ea 5/$20.00
MODEN CABLE
50' cable contains
13 # 22 ga. wire DB-25p with
DB-51 226-1 cover on one end
$6.50 ea 10/$5D.OO
New Dry NIcket-Cadmlum Battery
2Va'' )c2¥4"x 8¥4"
General Electric
12.0 Volts dc @ 4.0 Amp hrs,
$19.95 while they tast.
PANEL METERS
ZVr X 2V4" also 2V4" X 3"
10-0-10 dc Amps . $4.00 ea
0-20 dc Volts
25-0'25 dc Volts > 2 for
0-25 dc Volts \ $7.00
0-50 ac Volts ^
-Shunt Required-
CB SPECIAL
Complete brand new printed circuit board assembly with
all parts. Used in all Hygain 40 channel CB Transceivers.
Fits many other manufactures units also.
Board dimensions 6" xSVa"
1-9— 7.50 ea
10-50— 6,60 ea
50-100— 6.00 ea
100-up— 5.50ea
MUFFIN FANS
3 Blades, 110 Vac, 4V4" sq.
Removed from equipment-
Excellent condition— $4.95
^*New" Muffin Fans
3 Blades-110 Vac, 4W sq.
$9.95
CMOS
RCA CD 4012 AE
Dual 4 in Nand Gate
6/$1.00 100/$1O.O0
50/$6.00 1000/$80.00
12 Vdc RELAY
SPST Open Frame
5 Amp Contacts
Mfg-Magnecraft
$1.50ea 4/$5.00
POLYFOAM COAX— 50 OHM
Equal to RG174
$4.95/100*
Low Loss
Polyfoam
Coax Cable
TRIMMER CAPS
Small enough to fit
in your watch—
3.5 to 20 pF
5 to 30 pF
7 to 40 pF
$75 ea., 2 for $1.25
5 for $3.00
DCellNicad
mfg. by G, E. 2.50 ea
1,2 volts 3.5 amp hrs.
cat No. 41B004 AD08G5
Computer Grades
23,200 uf @ 50 Vdc 3.00 ea
3^^dlamx4y2" highG, E,
Coax Connectors
UG-273/U BNC-F/UHF-M 2.50
UG 255/U BNC-M/UHF-F 3.00
UG'146A/U N'M/UHF-F4.50
UG-83B/U N-F/UHF-M 4.50
UG-175 RG-5a Adapt. .20
Uai76RG-59 Adapt. .20
New Boxer Fans
5 Blades 110V ac
43/4-_$ii^95
JOY STICK
For TV games and hi fi
with four, 100K pots
23/4" X 2W X 1"
with V handle— $3,95
GOLD PLATED CARD EDGE CONNECTORS
Double Row/Wire Wrap ,100
25 pins $3.49 ea 10/$30,00
30 pins $3.96 ea 10/$32.00
50 pins $5.43 ea 10/$45.00
PoubiB Row/Solder Eyelet .156
Spins $1,10 ea 10/$9.00
15 pins $1,55ea 10/$12.50
22 pins $2.08 ea 10/$17.00
43 pins $3.66 ea 10/$30.00
22 pins/ Double Row/Dipped Solder
.156 $2.08 ea 10/$17.00
22 pins/Double Row/Wire Wrap
,156 $2.44 ea 10/$19.00
Aff ma ten A { gu^rsnteed • if for any reason you are not satisfied, our products may tie rettjrnei^ wrthfn W days for s tuii refartd {less shipping}. Pfease add $
TER MS- for shipping snd handiing on stf orders. Additional 5% charge for shipping any item over 5 fi?S- COD's accepted for orders totaffog $50.00 or more. AH order
shipped UPS unless otfierwise specified. Florida residenfs pfease add 4% sales tax. Minimurr} order $15^00.
EQUIPMENT / COMPONENTS / W/RE& CABLE / ACCESSOHJES
310
GET YOUR
ue'*'
Published December Ist, 1978
Specialize in DX? Then you're
looking for the Foreign Callbook
with over 280,000 calls, names and
addresses of radio amateurs out-
side the USA plus many valuable,
additional features of interest to
the DXV.
FOREIGN GALLfiOOK
$14.95
PLUS SHIPPING
RADIO AMATEUR
CALLBOOKS
The U.S* Call book has over
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valuable back-up charts and
references you come to expect
from the Cailbook.
UNITED STATES CALL BOOK
T^^-
ym-.Kfr-
Respected worldwide bs
the only complete authority
for radio amateur
QSL and QTH information.
$15.95
PLU9 SHIPPING
See your favorite electronics dealer
for the latest issue or order direct
from the publisher using handy order
form.
Payment in U.S. funds must
be sent directly to publisher
not through a bank.
Radio
Amateur
callb
i^m
k
ORDER FORM
C
linn
□ "
S CALLBOOK
rn FOREIGN CALLBOOK
Pi-ic« EkK
^T
$15.35
S14.9S
S^vtp'pint
st.rs
$1.75
Tutjil Pirir
SI 7.70
$1S.70
\moh residents only add 5% soles tax
, INC.
niame.
Address.
TOTAL
925 SHERWOOD DRFVE
LAKE BLUFF, JLLJHOJS 60044
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iL
1*^ Reader Senftce — see pege 323.
311
Provides full frequency coverage. 220-225 MHz, lor your Midland 509.
Cobra 200t or Clegg 76 transceiver Provides simpler, repealef. and
reverse modes on all frequencies. New irripfoved mterface circuit pro-
vides greater flexibility and RF immunily. FULLY ASSEMBLED &
CALIBRATED
Cushcraft
Beam I
still only $129»*
ATTENTtON 22S OWNERS!
Buy your Synthacoder 509 during -c>^^^^^
our SOS sale and receive a ^^"^^^
FR€E Cushcraft BEAM AMTENNA /
Regular 87,95
SOS 69.95
"The Original" Synthacoder 22. used by many hundreds of ICOM ow-
ners throughout the country tor years! The ultimate in frequency con-
trol for the 22S Full thumbwheel control in 15 KHz steps. You won't
want to miss oul on th+s SOS Super Saverl
SYNTHACODERS ARE AVAILABLE
THRU YOUR LOCAL DEALER
We Are About To Announce Some New
"SUPER PRODUCTS"
WATCH FOR OUR ADS
E12 Engineering SpecialtieH
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OKnard. Cahfom^a 93030
(805} 4^6-0617
*
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Name
Address
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Yes I want to take advantage of your SOS Super Saver!
a Please BUSH my Synthacoder &09 and FREE BEAM ANTENNA
Enclosed is my $129,95 plus S3 00 postage and handling.
D Please RUSH my Synthacoder 22. Enclosed is my $69.95 ptus
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ALDELCO ELECTRONIC CENTER
OVERVOLT 12
Crow Bar circuit protects
Transceivers & Tape Decks from
runaway power supply voltage that
can zap expensive components. OV
12 causes fuse in Power Supply to
blow if voltage exceeds preset level
(approx. 16 to 18 volts), Rated at 25
Amperes. $ 7.95
Model 0V5- Protects 5 Volt circuits.
Triggers at 7.5 Vo?ts $8.95
Other units available at 3.3 to 100 Trig-
ger Voltages $10.95 ea
A EC 1074 50W
#30 MHz $21.15
A EC 1076 75W
m 50 MHz $24.00
botn cases 500 4LFL
THE LUNCH
COUNTER
1
LUNCH COUNT FA "^
Build a 600 MHz 6 Digit Frequency
Counter. We supply 3 PC Boards, Silk
Screened Front Panel and complete
Instructions OnJy $12.50
Chips used in Counter
11C90PrescaJer $14,50
74C925 9.95
F9368 {2 used) ea 3.95
NEW!
THE FUTURE NOW!
FM2015R
KDK
do** fDiJi uibi c.iiw*t Th* Niw
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■ G WHi BiTvd Cby/vwrn^ -1000Chann«l» rin4l«fta of tht uiuil 2MHi to 4KKz-400
t« 8D0 Ctmnn^^il^ ■ 4 CHA^ffyEL RAM IC MCMOftr WJtH SCAIVNfNG •
MULTII^L£ FBeaueNCV OFFSETS • ELECTRONIC AUTO TUNING TRANSMET
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DJSCftlMlh^ATOR METER:- iSWatti Output- Ufwqualad R«caib«t $Brti;|kw4iy«nd
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and Superror CommefclAl Awionic» Qr«d« QuilitV and CtirtilructiiDn Ss^ond to
None at ANY PRICE.
PRICE
Cc
Har<J to find replacement for
VHF MotJile t Marine use.
Successfully used in Stan-
dard and other VHF Rigs,
Rated t2 Watts at 200 MHz
12,5 Volts with 5.3 OB Gain.
Heat Sink stud (3/32)Jsolated
fromieads. Only $12.30
110 TTF
$439.95
**»»
C*W5 - ' ~: ^
-^.-IV.-ltsVpffc.
I
PHI^ ^ ^b^
■Jta™
RF DEVICES
AEC 1158
LEDS
Monsanto MAN 72 Red LED
Readout 300" High, Common
Anode ONLYS 69
Monsanto MV5053
and Holder
LED Hoiders, . , .. .
Jumbo Red LEDS
JUMBO LED
oniy .25
10
e for SI. 00
2N237e
aN3375
2N3553
2N3a66
2N3g26
2N4427
2N55a9
2N5590
2N5591
2N5913
2N6DeO
2N60S1
2N6082
2N6083
2N60a4
2N6094
2N6095
2N6096
2N6097
10W
3,0W
2.5W
LOW
7.0W
LOW
3.0W
10W
25W
1.75W
4.0W
15W
25W
30W
40W
4.0W
15W
30W
40W
200 MHz
4CM3MHZ
175 MHz
400 MHz
175 MHz
175 MHz
175 MHz
175 MHz
175 MHz
175 MHz
175 MHz
175 MHz
175 MHz
!75MHa
175 MHz
175 MHz
175 MHz
175 MHz
175 MHz
T060
T060
T039
T039
T060
T039
MT71
MTr2
MT72
T03G
MT72
MT72
MT72
MT72
MT72
X106 PNP
X106PNP
X106PNP
X106PNP
$12.35
5.60
L40
1.25
a 30
1.36
4.75
?.ao
10.25
1.70
5.40
6.45
10.95
12.30
16,30
6.50
8,50
10.35
20.00
ALDELCO KITS
DUAL DIGITAL 12/24 HOUR CLOCK KIT
NOW WITH A NEW WALNUT GRAIN WOOD
CABINET
Features:
n Si 31 S3 Bl 31
— THE MIMIC —
PROGRAMMABLE IAMBIC MEMORY KEYER
Jumbo Gfeen, Orange or Yeifow
LEDS 5 tor $7. 00
FETS
40673 .....1.55
MPF102 . .55
2N3ei9 35
2N5457 50
2N545e , 50
2rsl5459 55
3N5485 50
DARLINGTON
MPSA 13 - 60
MPSA 14 . ..40
2N5306 50
SCR
CIOGA. 55
C106Q...... 65
C 122B ,85
• Four memory inputs, sixty let-
ters each
• Five minutes of memory # 10
wpm
• Operates on 110 V ac and 6-16
vdc
• Triggered ciock for memory re-
cording
• Built-in side tone monitor
• Speed controi 5 to 40-plus wpm
• Two to three Hmes the memory
of nearest competitor
Comes in attractive iight
biue cabinet measuring
2y2 ' high x 4" wide
X 5" deep.
12 or 24 Hour Operation on either clock
Each Clock separately controHed
Freeze feature for time set
Easy assembiy tor clock and cabinet
BIG
0.5 LEDS
MODEL ALD5-W ONLY $49.95
KIT ONLY $7e.9S
Kft^ith set of paddles
Assembled unit, .._,..
Peddles onljf
$104.95
. . 99.&5
. 29.95
VOLTAGE REGULATORS
TO220 Package
Positive $1.00 Negative $1.25
7805 7905
7S06 7906
7808 7912
7812 7915
7815 7913
CLOCK CHIPS
5313 3,49
5314 349
5316 .............._.... .3-95
5375, 3.95
CT7001 6.95
2200 MFD 16 volt
Radial Cap 3 forS9q;
ALARM CLOCK KIT
6 Big 0.5 LEO Displays * On Board AC Transformer " 12
Hour Formal with 24 Hour Aiarm * Snooze Feature * Eiaps-
ed Timer. Timer feature makes this Popular in Broadcast
Stations. It's a naturai for cars, boats and campers when
used with optionai crystal tfime base, Fits our standard
cabinet. 319,95
Crystal time base when purchased with c iock. $2,95
12 or 24 HOUR DIGITAL CLOCK KIT
Uses 0,5 Dispiay LED, 5314 Clock Chip. Freeze feature for
accurate set, fitsour standard cabinet, ONLY$ia.95
CLOCK CABINETS ea,$4,95
Woodgrain or btacl^ leather
CRYSTAL TIME BASE KIT
includes PC Board, Crystai, all parts and instruc-
tions. $4.95
CLOCK FILTERS
Biue. Red, Green, Amber ot Smoke
Blinky Flasher Kit
PC board, 555 & all parts workg on 9 voK&- Mouse
$1.00
$.60
$295
on—
DIGITAL
MULTIMETER &
THERMOMETER
3Vi Digit— 5 ranges on each
function AC^DC .2 Volts to
2000 Volts Current 2
Microamps to 2 Amps
Resistance 2000 Ohms to 2
Megohms, includes PC
Board, ICL7107 Chip and all
parts. Only $49.95
LOGIC PROBE KIT
Measures Logic 1, Logic 0,
and pulsing circuit Condi-
tic n s N O W red u ced to $9.95
SPECIALS
MC1458P 29
655T(mer^ 3 for $1.00
4011 .23
CRYSTAL SOCKETS
HOLDS 8 HC25U - S .^^
SmgieHC25U 29
144 MHz 10 Walls
RF Transistor
2N55dO $5.50 ea.
NEW!
Tunable 420 MHz
Fast Scan TV
Converter
Receive Fast Scan Amateur TV in the 420 to 450 MHz Band
with any TV set. Low noise, high gain rf Amp with Varactor
tuned input and outputs- 9uMt in AG syppEy, Comes in two tone
walnut & beige catjinet measuring 1 7/8" x 4 1/4" x AVb''
Factory wired with 2 year guarantee. . $59.95
Self Completing Dots & Dashes
Samtjic Operation
Single Dot & Dash Memories
AC CU KEYER
KIT
Provision for attachment of 256 or 512
Bit Memory for DX or Contest work
ADJUSTABLE POWER SUPPLY KITS
5-1&Volts500MA
12 2&Vo(ts500MA
$6,95
e.95
Revised version of the Accukeyer featured rn the ARRL Handbook. Has
more logical IC Layout and ON Board sidetone Qsciilator. Includes PC
Board, TTL ICs^ S55 Timer, IC Soci^ets, Switch, Speaker, Transistors,
c apac I to rs and res i stor s , R eq u I res 5 V DC. ON LY S 1 9, 95
ACCUKEYER MEMORY KIT
Simple low cost Memory Kit. Uses 2 programmable 1 101 Memory chips. Pro
vides 2 canned messages of 30 Characters each. Adaptable to Handbook
and other Accukeyers. Includes PC board (same si^e as accukeyer board)
and all parts. Requires 5 VOC, 9 VDC. $19.95
ALDELCO
i^A2
2789A MILBURN AVE, BALDWIN, N.Y. 11510
516 378 4555
Add §7o shipping. Add $1,00 for orders und&r $10.00^ Out of UtS*A* add 15% shipping and certified chec}i or money order in U.S. funds^
f^ Reader Sen/fce—s^& page 323.
313
S^SiSi&*^ii^4ii44?^«(?^Alii3ii^li:¥i^^
North 32nd Street/Unit -1 Phoenix, Arizona 85018 [602] 856-8423
We accept checks, MasterCharge, and Visa
TYPE "N'^ FEMALE TO BNC MALE
$2.00 each
FRONT: BNC plug.
REAR: Type "N" Jack.
OESCR*; Permits the use of a type 'N" plug on
equiprnent using a 8NC jack. Std. Pkg. 1
UHF
(n) $1,50
UHF
o
O
CD
O
O
X O
3 O
O
$2-00
69«
LASCR
Light activat'
ed SCR. 200
PRV at .3
amps. Ex-
tremely sen-
sitive. 4 for $1-00
BNC
®
$2.00
BNC
®
Pot Hex Nuts
standard size
pot nut for all
standard size
bushings (3/8"
dia.)
25 for $1 .00
$1.50
PHOTO
TRANSISTORS
similar to FPT 100
4/99«
6g«
BNC
©
$1.50
BNC
PRIME
RED
LED's
Mini 10/79*
Jumbo
1 0/99<P
PHOTO
DARLtNQTONS
MOTOROLA
4/99«
^^^>^x
ALPHANUMERIC
5x7 DOT MATRIX
TIL — 305 same as
MAN 2, DL 57
33.50
Green Neon
Same as NE2
but glows ^'
GREEN Op- '
erates on t20V
t*
6 for $1 .00
■1
VHF
TUNING DIODE
Cj typ, 30 pt
Q 200 at 47 mc
2/99C
SOLAR
CELLS
2st2cm X, 13G mA
$1,49 ea.
Xenon Flash
Tube, Xformer
Flash tube with 4kv
trigger transformer.
Brand new. Great
for photographic &
strobe applications.
1-9/16 X 3/16 inch
flash tube. 1/2" by
5/16'* transformer.
Price includes both.
$1.75
1500V.
1 AiVlP
RECTIFIERS
10/$1-99
ii i-L •;
MfikCCW
MOLEXPINS
200 EACH El. 95
1000 EACH S7.95
SONALERT
eleclroriic
signal
tb.W
VOLTAGE
REGULATORS
6 V. at 1 Amp
2/99C
T0'220
for (hfil. professional Touch
CARBIDE
DRILL BfTS
for P.C, BOARD work
MJE3055
90 Watts 60VCE
10 Amps NPN
2/$1.50
NPN POWER TRANSIStORS
2N 5301 (30A) $3.95
TO'3 200W 40V
BUY69B BUY69C
10A ISA
700 V $&.»S 400V $S.9S
DIP SWITCHES
$2.00
BNC
$1J5
6- $1 .50
7-S1.95
8- S2.00
Muffins Fans
SUB
WIINIATUHE
CRYSTAL
FILTER
455 KHz
S2.9S
The right toot for th^ job
Assortment will Indude
sizes ranging from
No. 55 thru No. 70.
5MIX/$7.49
10MIX/$12.49
100MIX/$d9,00
w -n ^
r^ "■ ^
^ < -i
-nro
><
3 o
T CO
N J-FET's
2N4303 . . .
Gen. purp.4/99C
WIRE WRAP
SOCKET PIN
HIRELGOLO
10/$1.25
1Q0/$9.50
100Q/$80
LIST PRICE 29t
CO
4^
00
CO
O CD
HEAT SINKS
1^^^
TO-5 30$
TO-3$1.50
used
$5,00
new
$9,9S
LM301A 4/$1.00
LM301N 5/$1.00
TO-220 25(p
BNC FEMALE TO TYPE "N" MALE
$2.00 each
ADAPTERS
BMC FEMALE TO UHF MALE
$2.00 each
FHONT:UHFprufl
HEAR: BNC jack.
DESCR.: Permils ine use of a BMC piiig on
equipmeni using a UHF jack. Sfd. PkQ. 1
CABLE REDUCING ADAPTER
FRONT: Type *N"|&lug.
REAR: BNC jacK
DESCR.: Permits the use of a BNC plug on
eciuipmert usmg a Type "N" jack. Std. Pkg. 1
50$ each
314
2822 North 32nd Street/Unit -1 Phoenix, Arizona 85018 [602] 856-9423
We Bccept checlcs, MasterCharge, and Visa
LIQUID
CRYSTAL
WATCH DISPLAY
Brand new reMective t^P^ LCD watch
readout made by MoEorola- Actual size on-
ly .940"L X .540H. Features hfgh contrasl
railo ol 25: 1 at a.OV bias. LCD readouts r^
quifo such (aw amoums ol current that
you can make lh« digits appear from
sialic charigies Very uniQue and hard to
find. Sorry, no socket avai table.
SI Each
Factory Box of 12 for $10.00
MOTOROLA
CRYSTAL 14-04 MHz
OSCILLATOR $1.98
m
Integrated circuit dock oscillator completely seIN
contained In a I'l pin package. Frequency stability
*,01 percent.t©mp0ratLrerangeO''Cto7O*'Ci input re-
quirement 5 V dc 10 percent. Al 40 mA, output is a
square wave, TTL compatible, with a rise and tall time
o* 10 nsec max. Size only .750" by 470 'W by .37a"'H.
Simple to use as il only requires 3 connections ( +
QND arKJ output). Great clock for CPUs. Timers. Time
Bases. Frequency Count»^. CVM, Clocks, etc. Brand
new prirrye!
BURROUGHS
PANAPLEX II
9 DIGIT DISPLAY
4'iiLL
J : [ 1 ; ' ] ! I ; ! : 1^
l^L^LLlZjjGa
3 for $1
Tvpe 8^12259 gas discharge 7 segment
J'^play. Requnre^ 1^60 V dc. Righi hand
decimal on right of each digit. Br Ight and
ea^y to read, has IfB" thick glass over
ceramic substrate. Used, excellent cond.
No sockeis avaiiab^.
MINIATURE
VACUUM RELAY
JENNINGS
26.5V D.C. Coil
NEW StS.99
BAG FULL OF
HEAT SHRINK
89(p
'^^
Handy assortment of precut pieces ol high quality
heal strrlnk tubbing. Lengths vary from Vi" long to 1 '/*"
long and diameters vary Irom 1/8*' up to 3/8", Very
uselui for almost aH applications. Repeal able bag con-
lams a I least 70 pieces. Buy sevefal fc»r your work-
l^encti or lool kit,
SEMICONDUCTOR MOUNTING
HARDWARE ASSORTMENT
We purchased thousands of various
semiconductor mounilng hardware in- J-i (JQ
eluding Insulating rings, rectifier solder ^ ■ wV
lugs, spacers, nuts, etc. ^
^•2
100 pieces of se$ni conductor
mounting hardware.
METAL
CABINET
$1.49
Smaii aluminum cabinet with wood gram vmyl coher-
ing Has lettering on front panel and 5/Q'' hole cutout
Also has several of her holes in c^ase Gre^ for hun-
dreds of small projects. AppmK. srze: 3^3/4" sq. x T-7Aft"
W.
SEMICONDUCTOR
INSULATOR MICA
Useful assort-
ment of various
mica Insulators
tof most popular
devices. Assort-
meni of tO,
In , U
$1.00
STUD RECTIFIER
MOUNTir^G KIT
Prepackaged
mtng kit tor most
stud mounting
rectifiers & ^ener
diodes.
3 for 49e
®.
tii>
©
QUENCH '"^^^
TUBES
Required In many eSecironlc flash
units to control light byabscrbing
energy that would normally go to
ihe strobe tube. Brand new prime
units.
Typel atofSrOO
Type 2 4fof$10C}
T05
3579.545 KHZ
COLOR TV
CRYSTALS
$1.50
Prime crystals for use m
co\ot TV o» wrih tfte Na-
tional MM5369 to make a
portable clock timabaae.
HEAT SINKS
Black anodized aluminum solid
fin type heat sinks for T05 case
devices. Very high quality. Well-
made.
10 for $1.00
NEONS
Usefut neon lubes
used to Indicate
when a ptiotoflasti
capacitor has reached
the proper vol I age to
flash strobe tubes.
Assort men I conlains
several different
voltages.
20 for $1
DC TO DC CONVERTER tC
SCSSS9P
4i
This. Dc E:qnv<ar!Br IP kn cl« H lunsid' to
cortviri 5 V dc inio jfO V dc to 40 V (in
<j<ll3*nt]Jfl9 on MHPr choftBn SpecKi-
c«1 \y use ^u I f or circiJ 1 11 whDns Itiere I s
PtuT\e rn mint-drp pocl^H'S? wlifi dp-
{iJjiiAE ion sc^hematii: Ajtwi ittiK..
Sll»
SLIDE AND
ROCKER
SWITCH
ASST
SWITCH ASSORTMENT
Popular types— rotary, slide,
push-bull on. All brand new.
•#
6 for $1
m
SPECIAL?!
C103B SCR 200V
.8 amp.
8 for $1.00
-%-,
TO-3
^«
Power
transistcr
socket.
4 for $1.00
6 for $1
HIGH
VOLTAGE
ZENERS
All marked,
voltages to 200
volts. Some PC
Feads
10/51
GIANT SLIDE SWITCH
ASSORTMENT ^
4KV TRIGGER CO[LS
AT LEAST 5 DIFFERENT TYPES 20fOr$1
9 Dtt3IT eOWMAR OFTOSTlf^
l^agnlller lOP. 9 digit display for
caiculalors. etc. Size: 2 3/S"L x
3^4' W
*<
DATA LITE 707
Common anode 7 segment
LEO readout. Drivef 744d or
7447
WBt
$2.25
Small ferfite
coils required lo
Kenon flash tubes
iSubmm
2, Sid.
3. Encaps.
core trigger
fire" aU
2/$t 00
3iS1,00
FND10FAIRCHILD
Miniature— n2"High digits
Common cathode. Prime. T'^lt
GREEN
NEON LAMPS
Bright r^eon for
120 V ac— In-
stead oi the
usual orange
glow you gel ^
bright green
gfgw Use with
39 K re Bis tor.
6 for $1
ITT 200V. 1 Amp SCR.
Pfinr^e, in TO-18 metal
case.
12/$ 1.00
RG174«JSOOfun
Coaxial Cable
Precut 6 foot lengtt^s
ol most popular m*nl
cable,
6^ length 25C
Price per 10 iengtha.
S1.75
ac
.01 hi^FD 50
V Micro
capacitor
Shown ac*
tual size
8 for $1
PHONE
YOUR
ORDER IN
602-9569423
WE LIKE CO 0/s
GPSA.13
DARLINGTON
TRANSlSTOft
ISforSiJOO
.{M7 MFD Micro
cap PC Feads
10 for SI
*^ fleatfcf Se^/ce— see ^sg0 323.
315
I
License sTudy quidES&TApES
Novi
Clas
Licen
Stud
Guid
• NOVICE STUDY GUIDE— S67357— Here is a completely new study
guide and reference book for Itie potential ham. This is not a ques-
tion/answer memorization course. Electronic and radio fundamentals are
presented and explained in an easy4i>understand fashion, preparing the
beginner for the Novice exam. Includes the latest FCC amateur regula-
tions, as well as application forms. Easily the best path into the exciting
world of ham radio! $4.95,"
• GENERAL CLASS STUDY GUIDE— SG7358— A complete theory course
for the prospective General or Technician. This reference explains tran-
sistor, amplifier, and general radio theory, while preparing the Novice for
the "big" ticket. After getting your ticket, you'll use this guide again and
again as an electronic reference source, f^ot a question/answer guide that
becomes dated when the FCC updates the amateur exams. S5.95.*
• ADVANCED CLASS STUDY GUIDE— SGtOSI — Ready to upgrade your license? To prevent retaking the FCC theory exam, you
fmBC the 73 Advanced theory guide. SS8, antenna theory, transmitters, and electronics measuring techniques are covered in
detail in this easy-to-follow study guide. Special modes and techniques, such as RTTY, are also treated. An engineering degree is
not necessary to master Advanced tlieory— try this book before visiting the examiner's office'. $5.95."
• EXTRA CLASS LICENSE STUDY GUIDE— SG 1080— Before going for your 1 x 2 call, it pays to be a master of the Extra class
electronic theory. This study guide Is the logical extension of the 73 theory course. All the theory necessary to pass the exam is
presented. Antennas, transmission lines, swr are discussed, as weH as noise, propagation, and specialized communication
techniques. This book is not a classroom lecture or memorization guide, but rather a logical presentation of the material that must
be understood before attempting the Extra exam. Save yourself a return trip to the FCC and try the 73 method f irsti S5.95/
n NOVICE ^f
NOVICE THEORY TAPES
Startling Learning Breakthrough
• NOVICE THEORY TAPES— CT7300— Startling Learning Breakthrough. You'll be astounded at how
really simple the theory is when you hear it explained on these tapes. Three tapes of theory and one of
questions and answers from the latest Novice exams give you the edge you need to breeze through
your exam. 73 is interested in helping get more amateurs, so weVe giving you the complete set of our
tapes for the incredibly low price of ONLY $15,M.'
Scientists have proven that you learn faster by listening than by reading because you can play a
cassette tape over and over in your spare time— even while you're driving! You get more and more info
each time you hear it.
You can't progress without solid fundamentals. These four hour-long tapes give you all the basics
you11 need to pass the Novice exam easily. You'll have an understanding of the basics which will be
invaluable to you for the rest of your life! Can you afford to take your Novice exam without first listen^
Ing to these tapes? Set of 4— $15.95.*
7jf IMOVIGE ^ ^1
3 *il
SSTV
• SLOW SCAN TELEVISION
TAPE— CT7350— Prize-winning
programs from the 73 SSTV
contest. Excellent for Demo!
73 CODE SYSTEM TAPES
f^^^^,
Any Four Tapes For S15.9BI*
•4.95 Each!*
II
II
S WPM-CT730&— This Is the beglnntfig
tape lor peopie who do not know the Codt
at alL It lakes them through the £6 letters,
10 numbers and necessary punctuation,
complete with practice every^ step of the
way ysin{} the newest blit; leachina tech
niques It is almost mtfaculousl in one
tiour m»ny peopfe— incEuding kids of ten
—are able to master the ctKfe. Hve ease of
learning gives confMj#n09 to bcftinnerA
Mtio migtii oinefwts^ drop out.
"THE STICKLER"
6+ WPM— CT7306-Thts Is the practice
tape fof Iha Novice and Technician li>
oens^iB. II is made up of ofie SDJid hour of
Qode. sent at the official FCC standard (no
O^her tape we've heairf uses these stan-
dafds, so many people flunk the code
when they are sud^Jenly— under pressure
^faced wllti characters seni at 13 wpm
and spaced for 5 wpmj. This tape Is noi
memof Isable. unhke the rany 5 wpm tape,
since the code groupsare entltely random
characters sent in groups af five.
"THE CANADIAIU"
*©+ WPM— CT7310— 73hasn t fofooiien
Ihe Canadian hams— our 10 WPM tape
prepares you to breeze through your coun-
try's licensmg exams. Like the other code
groups, the tape is not memorizable and.
once mastered, provides a margin of safe-
ty in the actual teict situation.
"BACK BREAKER"
13+ WPM — CT7313 — Code groups
aQaln. m a brisk t3 per so you will be at
mA&& wt^en you sit dowft In frcHit of the
steeiy^yed govemment inspector and fm
starts sen£i^fi$ you plain language at ortfy
13 per. You n^ad this exira margin to over-
come the pantc which is universal fn the
test siluailons. When you've spent /our
money and time to take the test, youll
tiiank heavens ygu had this back-breaking
tape.
"COURAGEOUS
Ji
204 WPli— err 320— Code is what gets
you when you go for the Extra class li-
cense. It is ao embarrassing to pan^c out
just because you didn't prepare yourself
with this tape, Though ttiis is only one
word faster, the code groups are eo diffi-
cult that you'll almost Tali asleep copying
Ihe FCC stutf tjy comparison. Users feport
that ttiey can't believe how easy 20 per
really is with this fantastic one rtour tape.
tf
OUTRAGEOUS
»f
25+ WPM -CT7325— This t% the tape for
I hat smaif group of overachieving hams
who vrouldn t be content to simply satisfy
the code requirements ot the E^tra Class
license. It's the toughest tape we've got
and we Keep apefmaneni flleof hams who
have mastered it. Let us know when you're
up to speed and we'll mscrit>e your name
In 73 s CW Hull of Fame "
^ 73 Radio Bookshop • Peterborough NH 03458. Be sure to inciude check or detailed credit card information.
Add $1,00 handling charge fof orders under $10.00. Note: Prices subject to change on books not published by 73 Magazine,
kl«l#«E #%AI I
7^ TEChNJCAl libRARy
• BEHIND THE DIAL— BK7307— By Bob Grove. Get more fun out
of shortwave listening witii this interesting guide to receivers,
antennas, frequencies and interference, $4.95.*
• THE CHALLENGE OF 160-BK7309-fs the newest book in the
73 technical library, dedicated to 160 meter operating. Si Dunn pro-
videsaH necessary information to get started on this unique band.
The all-important antenna and ground systems are described in
detail. The introduction contains interesting photos of Stew
Perry's (the King of 160) shack. This reference is a must for new
and experienced 'Top Band" operators. Price: $4.95.*
• IC OP-AMP COOKBOOK— BK1 028— by Walter G. Jung. Covers
not only the basic theory of the IC op amp in great detail, but also
includes over 250 practical circuit applications, liberally il-
lustrated. 592 pages, SVa X 8V2, softbound, $12.95/
• INTRODUCTION TO RTTY— BK7380— A beginner's guide to
radiotelelype inciuding teletypewriter fundamentals, signals,
distortion and RTTY art. You can be a RTTY artist! A 73 pubiica-
tion, $2.00/
• THE NEW RTTY HANDBOOK-"BK7347-is a new edition and
the oniy up-to-date RTTY book aval table. The state of the art has
been changing radically and has made all previous RTTY books ob-
solete. It has the latest circuits, great for the newcomer and expert
alike. $5.95/
• PROPAGATION WIZARD'S HANDBOOK— BK7302— by J. H.
Nelson. When sunspots riddled the worldwide communications
networks of the I940's, John Henry Nelson looked to the planets
for an answer. The result was a theory of propagation forecasting
based upon interplanetary alignment that made the author the
most reliable forecaster in America today. The book provides an
enlightened look at communications past, present, and future, as
well as teaching the art of propagation forecasting. $6.95/*
• SSB . . . THE MISUNDERSTOOD MODE— BK7351 —by James B.
Wilson. Single Sideband Transmission . . . thousands of us use it
every day, yet It remains one of the least understood facets of
amateur radio. J. B. Wilson presents several methods of sideband
generation, amply illustrated with charts and schematics, which
will enabte the ambitious reader to construct his own sideband
generator. A must for the technically-serious ham. $5-50/
• SSTV HANDBOOK— BK7354(hardcover), BK7355{SoftCover)—
This excellent book tells all about It, from its history and basics to
the present state-of-the-art techniques. Contains chapters on cir-
cuits, monitors, cameras, color SSTV, test equipment and much
more. Hardbound $7.00. softbound $5.00.*
• WEATHER SATELLITE HANDBOOK— BK7370— Simple equip-
ment and methods for getting good pictures from the weather
satellite. Antennas, receivers, monitors^ facsimile you can build,
tracking, automatic control (you don't even have to be home). Dr.
Taggart WB8 DOT, $4,95.*
ANTENNAS
• 73 DIPOLE AND LONG-WIRE ANTENNAS— BK1016— by Ed-
ward M. Noll W3FQJ. This is the first collection of virtually every
type of wire antenna used by amateurs. Includes dimensions, con-
figurations, and detailed construction data for 73 different anten-
na types. Appendices describe the construction of noise bridges,
line tuners, and data on measuring resonant frequency, velocity
factor, and swr. $5.50.*
• 73 VERTICAL, BEAM AND TRIANGLE ANTENNAS— BK1069^
by Edward M. Noll W3FQJ, Describes 73 different antennas for
amateurs. Each design is the result of the author's own ex-
periments covering the construction of noise bridges and antenna
line tuners, as well as methods for measuring resonant frequency,
velocity factor, and standing-wave ratios. 160 pages. $5.50.*
• VHP ANTENNA HANDBOOK— BK7368— The NEWVHF Anten-
na Handbook details the theory, design and construction of hun-
dreds of different VHF and UHF antennas ... A practical book
written for the average amateur who takes joy in building, not full
of complex formulas for the design engineer. Packed with
fabulous antenna projects you can build. $4.95,*
73 Radio Bookshop • Peterborough NH 03458. Be sure to include check or detailed credit card information.
Add $1.00 handling charge for orders under $10.00. Note: Prices subject to change on books not published by 73 fvlagazine.
TEST EQUIPMENT
• RF AND DIGITAL TEST EQUIPMENT YOU CAN
BUILD— BK1044—Rf burst, function, square wave generators,
variable length pulse generators— tOO kHz marker, i-f and rf sweep
generators, audio osc, af/rf signal injector, 146 MHz synthesizer,
digital readouts for counters, several counters, prescaler,
microwave meter, etc. 252 pages. $5.95/
• VOL. I COMPONENT TESTERS— LB7359— .-. how to build
transistor testers (8), diode testers (3), tC testers (3), voltmeters
and VTVMs (9), ohmmeters (8 different kinds), inductance (3),
capacity (9), Q measurement, crystal checking (6), temperature (2),
aural meters for the blind (3) and all sorts of miscellaneous data on
meters . . . using them, making them more versatile, making stan-
dards. Invaluable book. $4.95.*
• VOL, II AUDIO FREQUENCY TESTERS— LB7360— ,.. jam
packed with all kinds of audio frequency test equipment. If you're
into SSB, RTTY, SSTV, etc., this book is a must for you ... a good
book for hi-fi addicts and experimenters, too! $4.95.*
• VOL. Ill RADIO FREQUENCY TESTERS— LB7361 — Radio fre-
quency waves, the common denominator of Amateur Radio. Such
items as SWR, antenna impedance, line impedance, rf output and
field strength; detailed irrstructions on testing these items in-
cludes sections on signal generators, crystal calibrators, grid dip
oscillators, noise generators, dummy loads and much more.
$4.95/*
• VOL. IV 10 TEST EQUIPMENT — LB7362 — Become a
troubleshooting wizard. All you need to know about pulse, audio
and sync generators, frequency counters, digital component
testers, logic probes and morel Pius a cumulative index for all four
volumes oT the 73 Test Equipment Library, $4.95 *
tIiE WEll-EQuippEcl llAIVI sIlAck
S.l,«5
tfkxm
:...;1
.-■^ .
^j-iJ-^-i\
\_^P^oM^^^'''
l^*»/f
b-': -_^.^
**Pfc-TifcMff.ii >-%iii jiji^^bpBWAt
Style X
Stv*e W
Style Y
W^^
•~^j
• NEW REPEATER ATLAS OF THE EN-
TIRE WORLO-BK7345-150% as big as
any list ever available— nearly 900 more
repeaters listed. New improved maps
show the locations by frequency of every
repeater In the States. Only $1.95.*
• QSL CARDS— 73 turns out a fantastic
series of QSL cards at about half the cost
of having them done elsewhere because
they are run as a fiil-in between printing
books and other Items In the 73 Print Shop.
250 Style W--QW0250— for $8.95*; 500
Style W— QW0500— for $13.95*; 250 Style
X-QX0250— for $8.95*; 500 Style X-
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• 73 MAGAZINE BINDERS— Preserve and
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There's no excuse for lost issues when you
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• BACK ISSUES- Complete your collec-
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criD mieTniuicD ecDifir«i
Ai I cno OQA c^a^i
irTT
III
m
• SSB . , , THE MISUNDERSTOOD MODi
— BK7351— by James B. Wilson. SmgJe
Sideband Transmisston . . . tJiousands ol
us use it every day^ yet^ it remains one of
the least undefstood facets of amateur
radio. J B. Wilson presents several
methods of sideband generation, amply il-
lustrated with charts and schematics,
which wil) enable the ambitious reader to
construct his own sideband generator. A
must for the technically-sefious ham.
$6.50. '
• PROPAGATION WIZARD'S HANDBOOK
— BK7302— by J. H. Nelson, When sun-
spots riddled the worldwide communica-
tions networks of the 1940's, John Henry
Nelson looked to the planets for an
answer. The result was a theory of propa-
gation forecasting based upon mterplan*
etary alignment that made the author the
most reliable forecaster in America today.
The book provides an entightened look at
communications past, present, and future,
as well as teaching the art of propagation
forecasting. 6.96.*
• A GUIDE TO HAM RADIO- BK7321 -by
Larry Kahaner WB2NEL. What's Amateur
Radio all about? You can learn the basics
of this fascinating hobby with this ex-
cellent beginner's guide. It answers the
most frequently asked questions in an
easy-going manner, and it shows the best
way to go about getting an FCC license. A
Guide to Ham Radio is an ideal introduc-
tion to a hobby enjoyed by people around
the world, $4.95.*
• VOLUME IV--IC TEST EOUIPMENT-
LB7362— it's easy and fun to build your
own test equipment with ICs! Here in this
fourth volume of the 73 TEST EQUIPMENT
LIBRARY are 42 home construction proj-
ects for building test equipment to work
with your ham station and in servicing
digital equipment. Counters, scalers, fre-
quency standards, synthesizers, logic
probes . . . JUST ABOUT EVERYTHING
you need and can build with ICs. $4.95/
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print NEW address here:
Name
Call.
Address^
City
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Try q
Zip,
y
Pi'opa^ation
by
J, H. Nelson
EASTERN UNITED STATES TO:
GMT:
00
02
04
oe
oa
10
\7
14
16
IB
20
22
AIUASKA
14
?A
1
7
14
14A
31A
31
AMGENTINA
14
?.ft
Id.
21
21 A
31A
21A
31
AUSTRALIA
ST
14
7B
7?
76
14
UA
?1
J1
ZtA
CANAL ZONE
14
7A
14
51
71 A
71 A
21 A
21
ENGLAND
7
7
7B
14
71 A
31 A
14
76
7
HAWAII
51
14
7B
7
7&
14
?1
2lA
21 A
INDIA
7
: 7
7e
76
7fl
7B
14
14A
14
76
7B
7
JlAPAIW
14jA
14
7B
75
7
7
76
7S
76
14
MEXtCO
14
7A
7
14
21
21A
2lA
21
PHILIPPINES
14
14B
7B
7B
7fi
7fi
7
7
7a
T&
70
14
PUEnTQ RICO
14
7
]4
21
21A
21A
21
14
SOUTH AFRICA
14B
7B
76
14
21
ilA
3lA
31 A
31
14
y, S, S, R,
7
7
70
14
31
14
7B
7B
7
W^ST COAST
31
14
^
7
14
21
21A
33A
21
CENTRAL UNITED STATES TO:
ALASKA
2T
14
7
7
7
Ii4
14A
Z1
21 A
AHGENTIMA
14A
14
7
14
21
21
31 A
21 A
31 A
AUSTRALIA
2lA
14
7H
7Q
?6
7B
14A
2T
7\
2]
CAMAL ZONE
31
T4 1
7
14
21
it A
SI A
21 A
31A
EhJf^LAND
7
7
7
7E
14A
JIA
>4
7&
76
HAVlFAII
?t
14
7S
7
J
14
31
3lA
2TA
fNOlA
7
1
m
/e
7B
7H
7B
14
14
7B
76
7B
JAPAM
31
fA
7fl
7B
7
7
7
78
76
14
MEXICO
14
7A :
7
2>
3t
21
7
14
31
PHILIPPINES
21
14
7S
fB
7E
7
7
76
7H
7
7 a
14
PUERTO niCD
14
7A
7
7
14
71
?tA
aiA
21 A
21
SOLITH AFAICA
14
7B
7
7fl
7B
14
31!
IlA
21A
1
21
21
U, S.S, R,
7
J
7
7
7a
7e
14A
14
IS
7B
76
WESTE
RN UNITED STATES TO:
ALASKA
21
14
?
$A
?A
7
3A
7
14
21
21A
ARGENTINA
21
14
14
•J&
14
21
21
71 A
71 A
AUSTRALIA
21A
21
14
7B
is
7B
3 4
71
?1
21A
CANAL 20NE
J1
14
7
7
14
71A
?1ft
?!A
21A
ENGLAND
fn
7
7
7&
T4
21
14
76
7B
HAWAII
JIA
21
14
7
7
14
21
31 A
21 A
INDIA
14
14
7B
7B
7B
7e
79
7
7
76
7B
7B
JAPAN
?1A
14
7B
?&
7
7
7
76
14
r4A
MEXiCO
21
14
7
7
14
21
31A
31 A
31
PHJLtPPIiNE^S
21 A
71
T4€
7H
7a
76
7B
7
7
7
7fi
14A
PUERTO fH CO
71
14
7
7 j
14
71 ^
31 A
21A
21
SOUTH AFmCA,
14
14B
7 1
7B
7B
7B
14
71
STA
21A
21
Lf, S,S. ft.
?fi
1
7
7ft
76
m
14
1*B
'B
78
*■
ErtSt COAST
31 Il4 1 7 1
7
7 1
7
14
J1
?1A
?]A :
A = Next higher frequency may also be useful
B = Offftcult circuit this period
F = Fair
G = Good
P = Poor
SF = Chance of solar flares
deoember
sun
1 moffi
IM-
w«cf
iriu
tfi
■■1
O O
>« 1. 4b H
—Ag-
1
G
2
G
3
G
4
G
F
6
F
7
G
8
G
9
P/SF
10
P/SF
11
F
12
13
G
14
G/SF
15
G/SF
16
P/SF
17
P
18
G
19
20
G
21
G
22
G
23
G
31
G/G
25
G
26
F
27
G
28
G
29
G
30
F
321
Sll§l(o|SSfa© peterborougK, n-h. 03458
A46 ABC Communications, 247
A1 Adirondack RadloSupply . 78
A24 Adva Electronics. 300
A60 AED Electronics 77
A2 Aideico ..,^ 313
A47 Aluma Tower Company 290
A40 Amateur Radio Supply of Nash-
ville Jnc - 213
A51 Amateur Radio of Rochester . 163
A2G Am idon Associates , 113
A70 AM P S p e c Ian n d u str i©5> * , - . . 204
Amsat 229
A6 Aptron Laboratories 279
A50 Associated Radio 308
A64 Aureus Elec, IncJEdgecorti . , . 71
B1 Babylon Electronics 288
B23 Baj-ker-Williamson 191
B32 Bay-Com , 2B0
B41 Belden .....272
B29 BrHt's 2'Way Radio 178
08 Bullet Electronics 296, 297
G30 Burghardl Amateur Center. . . 225
CBS C & A Electron tc Enterprises . 205
C3 Clegg. .... ,. 125,179
C21 Coakit ... 280
C95 Cohoon Amateur SupplyiEdge-
com , 47
C75 Com m Center, Laurel 232
C106 Command Productions 279
C105 Communications&TVUnltd . -276
Cse GommuniGationsCtr, NE , 249, 273
C96 Communications Center, NE^
Edgecom . »...,,,.....,. .... .69
05 Communications ElectfOni OS . 159
C89 Communications Sen/ices , , . , 202
C6 GOTTimunications Specialists 24, 25
C90 Curtis Electro Devices .140
Dade County Hamfest . . , , 190
D6 Peter W. Dahl Company 1 71
D10 Davis Eiectronics 290
D35 Day tap ro Electronics, Inc 283
D39 Jim DeNinno & Co. 279
D15 DenTron 5
D29 Dfeiectric 211
D20 Digital Research Corp 302, 303
D23 Dovetron ..... 77
D11 R.L Drake Company 94,95
D25 DSl instruments 21,220,221
El ECM Corporation .._,,,.. 75, 79
E19 Edgecom 35
E12 Engineering Specialties ...... 312
F5 Fles her Corporation _ 265,283
G 1 2 Germanto wn Am ate u r Su p ply .171
G20 G &G Radio Electronics Co . . . 281
G22 G.iS.M.0 282
G23 Globaiman Products 211
G4 God bout Electronics 304
HAL Gornmunications Corp. ...76
H24 Hai'Tronix 263, 265
H2 Ham Radio Center 215.291
H31 Ham Radio Outlet. 289
H16 Hamtronics, NY 299
HS Hamtronics, PA ........ . 236^245
H26 HartvweiisOfficeWorid 290
H30 HeuerTime & Eiectronics 158
H3 Henry Radio ........ Gil, 117
H32 Hobby Systems 279
H4 Hy Gain Electronics ......... 45
i1 ICOM .,.17
132 Instant Software 180, 181
19 Integrated Circuits, Unltd 306
127 IRL 23
J 1 Jameco Electronics .......... 305
J2 Jan Crystals. 140
JS JRS Electronics , .75, 260
K13 Kantronics 163
Kilobaud 16&
Kenwood.-.. CIV, 6^13
K1 4 Key Electronics , . .281
L18 Lafayette ........ .2i
:^
L9 Long s Electronics 194-199
Li 7 Lunar Electronics 60
M35 Madison Electronics Supply . 139
M36 MaggioreEiectronlcLab ....229
M71 Matric . . , . ._.,_... 54
M52 MFJ Enterprises 45, 103, 282
Ma MHZ Electronics 292,293
M69 Micro Control Specialties. . . . 279
M48 Microtfonics 19, 281
M62 Mid Com Efectronics, IncJEdge-
oom ._...,.,................ .63
M41 Midland International ,..,,. .233
N2 NeW'Tronics ... 141
N14 Northern Radio . . 265
05 OK Machine StTooi 171,173
03 Optoetectronics, Inc 301
P15 Pace-Traps . 281
P30 Paiomar Electronics .... 138
Paiomar Engineers,*... 19
P41 P.C. Electronics. 75
P2 Poly Paks .... 309
P25 Printed Circuit Products . . , . 280
P21 Priority One 151, 153
Q3 Quest Electrontcs 294
B1 Radio Amateur Gailbook, Inc.. . 31 1
Radio Worid..... ...,,75
RIO Raintx)w Industries , , , 77
R8 Ramsey Electronics. 29, 298
R25 F. Reichen & Saies 307
R27 RF Power Labs, Inc 276
R. Lee Tower International .., 283
R15 Roim Distributors. ...... . . . .290
R21 Hush Electronics . . ! 288
HI 8 R. W. Electronics, Inc. . 279
S63 Semiconductors Surplus 314,315
S3 Sentry , 76. 282
S39 Sere-Rose & Spencer Eiec. ... 281
S 33 S F Am at eur R ad io Servi ces 75, 264
S58 Shakespeare ,.,.,,.... 257
S70 Signetics 272
S4 Slep Elecironlcs Co 178
S8 Spectrum Com 1 10, 1 1 1
S10 SST Electronics 87, 98. 89
S50 O. C. Stafford Electronics 281
S1 8 Standard Communications . . 190
S38 Stuart Electronics , , 288
S43 Surplus Eiectronics 310
TenTec 135
T34 Thomas Communications . . . 261
T48 Tower Electronics Corp. ..... 1 13
T44 Tower Electronics CorpJEdge-
com 43
T18 Trac Electronics J nc . 79
T35 Trans Com — 280
T3 Tufts Radio Eiec. . . . 232, 266-269
145 Tufts Radio Electronics/Edge-
com , . . 59
U2 Unarco-Rohn 283
Ue United Products . , . - 295
ue U n I VG rsal Am at eu r R ad io Servi ce ,
inc 79
VI Vanguard Labs 75
V5 VHP Engineering ....... 27
Via VHF Engineering/Edgecom . . .55
WIS Wacom. ,....,... 78
W17 Westcom Engineering, , . . 42, 140
Vtfia Western Electronics 79, 280
W2 Wilson Eiectronics 3
Y 1 Y ae E u E I ectron I cs CJoqp^ CI H
21 Z22 Electronics, Inc. 264
From 73 Pages 77, 259. 316-322
^Reader Servi€« inquiries not honored.
Please contact ad vert is er directly.
/^
BK1016
STOOOO
ST2500
ST0500
ST 1000
ST2501
BK7307
BN1001
BN1002
BK7309
CT7305
CT7306
CT7310
CT7313
CT7320
CT7325
CT7399
CT7394
BK7321
BK7325
BK1028
BK7380
CT7300
BK1100
B K7302
QW0250
73 DIPOLE & LONG WIRE ANTENNAS ....,.$ 5.50
73 BACK ISSUE, $ 3,00
73 BACK ISSUES— 25 OUR CHOICE $10.00
73 BACK ISSUES— 5 YOUR CHOICE . . $ 5.00
73 BACKlSSUES-10 YOUR CHOICE $12.00
73 BACK ISSUES— 25 YOUR CHOICE $20.00
BEHIND THE DIAL $ 4,95
BINDER— 73— 1 ,$ 6.50
BINDER— 73--2&UP $ 6.00
CHALLENGE OF 160 $ 4.95
CODETAPE— 5 WPM $ 4.95
CODE TAPE— 6 WPM $ 4.95
CODETAPE— 10 WPM $ 4.95
CODE TAPE— 13 WPM $ 4.95
CODE TAPE— 20 WPM $ 4.95
CODE TAPE— 25 WPM $ 4.95
CODETAPE— LEARN MORSE CODE $ 4.95
CODE TAPES (ANY FOUR ABOVE) ,$15.95
GUIDETO HAM RADIO $ 4.95
HOW TO BUILD A MICROCOMPUTER $ 9.95
IC OP AMPCOOKBOOK $12.95
INTRO TO RTTY $ 2.00
NOVICETHEORYTAPES $15.95
PRACTICAL TEST INSTRUMENTS $ 4.95
PROPAGATION WIZARD'S HANDBOOK. . $ 6.95
QSL CARDS— STYLE W— 250 $ 8.95
QW0500
QX0250
QX0500
QY0250
QY0500
BK7345
BK1044
BK7347
BX1000
BX1001
B XI 002
BK7351
BK7354
BK7355
GT7350
SGI 081
SG1080
SG7358
SG7357
LB 7359
LB7360
LB7361
LB7362
BK1069
BK7368
BK7370
QSLCARDS— STYLE W— 500 , . . . , $13.95
QSL CARDS— STYLE X— 250 ......$ 8.95
QSL CARDS— STYLE X— 500 ........,.,.,. $1 3.95
QSL CARDS— STYLE Y^250. .$ 8.95
QSLCARDS— STYLE Y— 500. .... , ... . . , . . $13.95
REPEATER ATLAS $ 1.95
RF DIGITAL TEST EQUIPMENT $ 5.95
RTTY HANDBOOK .......$ 5,95
SHELF BOX— 1 , $ 2.00
SHELF BOX— 2 , $ 1.50
oiH tL_r otJA^ — o Ui .■i..i..i.i...,i..* * 1 .tD
SSBTHE MISUNDERSTOOD MODE $ 5.50
SSTV HANDBOOK (HARDCOVER) , . . $ 7.00
SSTV HANDBOOK{SOFTCOVER) ..,......$ 5.00
SSTVTAPE , . , . . , $ 5.95
STUDY GUIDE— ADVANCED CLASS $ 5.95
STUDY GUIDE— EXTRA CLASS $ 5.95
STUDY GUIDE— GENERAL CLASS .$ 5.95
STUDY GUIDE— NOVICE CLASS ..........$ 4.95
TEST EQUIP LIB VI —COMP TESTERS .....$ 4.95
TEST EQUIP LIB V2— AUDIO TESTERS $ 4.95
TEST EQUIP LIB V3— RADIO EQUIP $ 4.95
TEST EQUIP LIB V4— ICTEST EQUIP. ......$ 4.95
VERTICAL BEAM & TRIANGLE ANTNS $ 5.50
VHF ANTENNA HANDBOOK ......,.-.$ 4.95
WEATHER SATELLITE HANDBOOK $ 4.95
322
uviiuuuutiuummvv
immuiumiummiVhi«iiinMii«iiniuii
4i
^ ^\\S\\\\\\\\\\\\\
\\\\\\\\\
\\\\\\\\\
mmy Load/Wattmeter; SP-101 PB Speaker/Patch; FT-IOI E 160-10M Transceiver with YC-601B
'ounter; FV-101B External VFO; YO-101B Station Monitor; FTV-250 2-Meter Transverter; FTV-650B 6-
R-101 Digital 160M-10M Receiver; FL-101 Ali Band Transmitter,
il Coverage Receiver; FRG-7000 General Coverage Digital Receiver; FP-301 13.8VDC Power Supply;
0-10M Transceiver; FV-301 External VFO; FT-301D Solid State Digital 160-10M Transceiver; FP-301 D
ly with Clock & Identifier; YO-301 Station Monitor; FC-301 Antenna Coypler; LL-301 Landliner Phone
r Supply.
e Band Transverter: FV-901DM Synthesized Scanning VFO; FT-901DM 160-10M The Smart Radio"
Station Monitor/Analyzer; FC-901 Antenna Coupler; SP-90tP Speaker/Patch; QTR-24 World Clock;
adset; YD-844A Hi/Lo Imp. Desk Microphone; YD-14S Ht/Lo Imp. Flexible Neck Desk Microphone.
d Held 2M Transceiver; YC-500E High Precision Frequency Counter; FT-227R 2M FM Mobile Trans-
er; FT-227RA 2M FM Mobile Scanning Transceiver-4 Memory; CPU-2500R/K 2M FM Mobile Com-
r; FT-7 20 W PEP Mobile Transceiver; FT-225RD 2M All-Mode Digital Transceiver; FT'625RD 6M All-
giver.
r/Microphone (FT-202 Accessory); YM-2500 Keyboard Microphone; FFDX-50 52 Ohm Low Pass Filter
THE CHRISTMAS GIFT OF A UFETIME!
YAESU ANNOUNCES THEIR SENSATIONAL COMPUTER AGE
CPU-2500R/K 2-METER 25 WATT TRANSCEIVER
Again, Yaesu, THE RADIO, takes a giant step fonvard with thetr computer age 4-bit Central
Processor Unit controlling the Phase Locked Loop. It allows selection of 800 PLL channels
with touch button station selection built into the optional keyboard mike . . . PLUS auto-
matic scan, up or down across the entire 2 meter band . . . PLUS four memory channels
. . . PLUS optional tone squelch encoding . . . PLUS tone burst . , . PLUS high SWR
and reverse voltage polarity protection . . . PLUS 3/25 watts of power . . . PLUS fixed
±600 KHz offsets . . . PLUS programmable offsets . . . PLUS tone pad microphone
option . . . PLUS bright 3/8" LED six digit frequency display and another LED for memory
display . . . and much more.
The CPU-2500R/K is a space age radio for discriminating amateurs utilizing the latest solid
state techniques and it's on your dealer's shelf today !
Pric« And Specifications Subjed To
Change Without Noiiee ot Obligation
wsu
I
YAESU ELECTRONICS CORP., 15954 Downey Ave., Paramount, CA 90723 • (213) 633-401
YAESU ELECTRONICS Eastern Service Ctr., 981 2 Princeton-Glendale Rd., Cincinnati, OH 452'
iiE^ffncl
tt^mmmm^i^^m^M
Price And Specjtications Subjecl To
Change Wifhout Notice Of Obligation
W
TAISU
YAESU ELECTRONECS COBPORATION
15954 Downey Avenue, Paramount^ CA 90723 (2X3) 633-4007
EASTERN SERVICE CENTER
9812 Prtnceton-Glendale Rd. , Cincinnati OH 45246
Lett to Right
Top Row :YP- 158"
Display/Frequent
Meter Transvertei
Row 2: FRG-7 Gei
FT-301 Solid State
13.8VDC Power Si
Patch; FP-4 4A Pi
Row 3: FTV-901 T
Transceiver; YO-9
YH-55 Super Soft
Row 4: FT-202R i
ceiver "The Mem
puterized Transci
mode Digital Trar
Row5:YM-24Spc
I
1278C
Mm
MA
MHz
«
MIC^
EVERY FEATURE YOU COULD
POSSIBLY WANT IN A 2-METER
FM RIG IS AVAILABLE NOW IN
THE KENWOOD TR-7600
-«
The new TR-7600 gives you...
• Full i-mi coverage t144.000"147 995 MHz) on
2 meters « 800 channels • Dual cDncentric knobs
for fast frequency change [lOQ-kHz anct 10-kHz steps}
• 5-kHz offset switch • MH^ selector switch. .Jor
desired band (144* 145, 14G, or 147 MHz) « Mode switch
for operating simplex or for switching the transmit
frequency up or down 600 kHz for repealer operation.,.
or for switching the transmitter to the frequency you
have stored in the TH-7BQ0's memory (while the
receiver remains on the frequency you have selectett
with the dual knobs) * Memory channeL.with simplex
or repeater (pfus or minus BOO kHz transmitter offset)
operation.
The optional RIH-76 Microprocessor Control Unit
provides more operating features to the
TR-7B0O 2-meter FHfl trafisceiver than found in any
other rig! Vith the Microprocessor Control Unit
attached to your TR-7600, you can...
• Select any 2-nii?ter frequency « Store frequencies in
six memories • Scan afl memory channels • Auto-
NWOO
a
i
1
N)
^ OM
$ kHr
TR-Tc .c:>
Actual Size
RM-76
Microprocessor
Control Unit
matjcally scan up all frequencies m b-kHz
• Manually scan iip or down m 5*kHz steps * ox^i lower
and upper scan frequency limits • Hesel sc. 144 MHz
• Stop scan (with HOLD button) • Cancel scan (for
transmitting) • Automatically stop scao on first busy
or open channel *
Subjecf io FCCv u^^-
• <3f
TRIO KENWOOD COMMUNICATfONS J
\f^^
1111 WEST WALNUT/COMPTON TA 90220
^KEIM\A/00
iMt^^^^i^^ ^t*'^*^